Prophylactic Treatment of Breast Implants With a Solution of Gentamicin, Vancomycin and Cefazolin Antibiotics for Women Undergoing Breast Reconstructive Surgery: a Randomized Controlled Trial (The BREAST-AB Trial)
Phase: PHASE3
Conditions: Implant Complication, Implant Infection, Implant Site Infection, Implant Capsular Contracture, Implant Site Pocket Infection, Implant Expulsion, Antibiotic Side Effect
Sponsor: Mikkel Herly

Study protocol 
Official title: Prophylactic Treatment of Breast Implants With a Solution of Gentamicin, Vancomycin 
and Cefazolin Antibiotics for Women Undergoing Breast Reconstructive Surgery: a Randomized 
Controlled Trial (The BREAST-AB Trial) 
NCT: NCT04731025 
Document date: 20/11/2025 
Version: 3.0 
This document relates to the ClinicalTrials.gov study record above. 

 
 
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20/11/2025 
Trial Protocol 
Prophylactic treatment of breast implants with a solution of gentamicin, 
vancomycin and cefazolin antibiotics for women undergoing breast 
reconstructive surgery: a randomized controlled trial (The BREAST-AB 
trial) 
Short Title: Local Antibiotics for Breast Implants 
Acronym: The Breast-AB Trial 
By 
 
Mikkel Herly, MD, PhD 
 
Mathilde Hemmingsen, MD, PhD 
 
Andreas Larsen, MD, PhD 
 
Tim Weltz, MD 
 
Version: 3.0 (20/11/2025) 
Sponsor Protocol Code Number: BREAST-AB-01 
 
EudraCT number: 2020-002459-40 
EU trial number: 2024-517672-38-(00) 
 
Date of Registration: 05-12-2020 
ClinicalTrials.gov: NCT04731025 
Funding number: Novo Nordisk Foundation 0058322, Medicine Fund of the Danish Regions R-189-
A4127 
Coordinating Sponsor-Investigator: 
Mikkel Herly, MD, PhD 
Department of Plastic Surgery and Burn Treatments 
Blegdamsvej 9, 2100 Copenhagen 
Phone: redacted 
 
 
 
 
Date: ________ 
Signature: ______ redacted _______________________________ 
 
 
 

 
 
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Trial synopsis 
Title: Prophylactic treatment of breast implants with a solution of gentamicin, vancomycin and 
cefazolin antibiotics for women undergoing breast reconstructive surgery: a randomized 
controlled trial (The BREAST-AB trial) 
Lay title: Local Antibiotics for Women Undergoing Breast Reconstruction Surgery with Implants 
Acronym: The BREAST-AB Trial 
Trial design: A multi-center, investigator initiated, 1:1 randomized, double blind, placebo-
controlled trial 
Intervention: Application of gentamicin, vancomycin and cefazolin in a saline solution onto the 
implant and the dissected breast pocket used for breast reconstructive surgery 
Objective: To determine the efficacy of local antibiotics in decreasing all-cause implant 
explantation 
Inclusion criteria: Age ≥ 18, female, signed informed consent, breast reconstruction with implants 
including immediate/delayed reconstructions, bilateral/unilateral reconstructions and with or 
without flap reconstruction 
Exclusion criteria: Pregnancy, breast feeding, known allergy towards any of the applied antibiotics, 
known anaphylactic reaction towards the same class of antibiotics as used in the trial, known 
allergy towards neomycin, known impaired renal function with GFR < 60 ml/min, participation in 
investigational drug trials and projects concerning disinfecting agents in the implant pocket 
 and myasthenia gravis disease 
Primary outcome: All-cause explantation of the breast implant within 180 days after the breast 
reconstruction surgery 
Secondary outcomes:  
- 
Time to explantation (days) 
- 
All-cause explantation of the breast implant within 1 year after the breast reconstruction 
surgery (Y/N) 
- 
Revision surgery with incision of the fibrous capsule within 180 days after the breast 
reconstruction surgery (Y/N) 
- 
Infection-specific revision surgery: Revision surgery due to clinically suspected deep 
surgical site infection with surgical access to the breast implant pocket or clinical signs of 
an infection in the breast implant pocket found intraoperatively within 180 days after the 
breast reconstruction surgery (Y/N) 
- 
Exchange of permanent implant to expander implant within 180 days after the breast 
reconstruction surgery (Y/N) 
- 
Surgical site infection that leads to antibiotic treatment within 180 days after the breast 
reconstruction surgery (Y/N) 

 
 
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Tertiary outcomes: Assessed for patients undergoing unilateral breast reconstruction  
- 
Time from surgery to discharge (days) 
- 
Re-admission within 180 days after the surgery (Y/N) 
Long-term outcomes: All-cause incision of the fibrous capsule and capsular contracture after 5, 10 
and 15 years 
Sample size: A total number of 1274 breasts undergoing breast reconstruction will be included in 
the trial. Assuming that 27 % of the patients undergo bilateral breast reconstruction, this entails 
1003 included patients  
Trial duration: 6 years  
Randomization: Stratified randomization according to the following factors:  
- 
Unilateral or bilateral reconstruction 
- 
Immediate or delayed reconstruction 
- 
Previous or scheduled radiotherapy within the follow-up period (yes/no) 
All patients undergoing unilateral breast reconstruction will be randomized to the trial drug or 
placebo in a ratio of 1:1. All patients undergoing bilateral reconstruction will be randomized to the 
trial treatment on one of their breasts and placebo to the contralateral breast. Combining these 
factors gives a total of 14 randomization strata per trial site. An allocation sequence will be made 
for each stratum and assign treatment in a fixed block size of two to ensure that the 
investigational drug and placebo is evenly distributed within each stratum 
Treatment: The intervention treatment will consist of 1000 mg vancomycin, 2 mL of 40 mg/mL 
gentamicin and 1000 mg cefazolin in a 500 mL sterile isotonic (9 %) saline solution. The placebo 
solution will consist of 500 mL of sterile isotonic (9%) saline. During the surgery, the responsible 
nurse will draw three 50 ml syringes from the infusion bag (in total 150 ml) and use it to wash the 
dissected implant pocket. Another 50 ml syringe will be drawn from the same infusion bag and 
used to wash the implant with the assigned solution prior to insertion in the implant pocket 
Clinical follow-up: The included patients will adhere to the standard follow-up program according 
to the guidelines of the local treatment site 
Blinding: The patients, surgeons and data assessors will be blinded to the treatment allocation 
throughout the trial period. The coordinating sponsor-investigator will be responsible for 
monitoring adverse events. The trial coordinating unit will have access to the randomization 
sequences. They will not take part in any treatment of the participants or analysis of data. In the 
case of emergency unblinding the trial coordinating unit can always be contacted 
Safety: Treatment-related adverse events will be reported and assessed continuously throughout 
the trial period 
 
 

 
 
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Trial Steering Committee 
Thomas Bjarnsholt, Civil Engineer, DMSc, PhD 
Professor at the Department of Microbiology, Copenhagen University Hospital, Rigshospitalet  
and Head of Costerton Biofilm Centre, SUND, University of Copenhagen 
Tine Engberg Damsgaard, MD, PhD   
Professor at the Department of Plastic Surgery, Odense University Hospital 
Peter Viktor Vester-Glowinski, MD, PhD 
Professor at the Department of Plastic Surgery and Burns Treatment, 
Copenhagen University Hospital, Rigshospitalet 
Mikkel Herly, MD, PhD 
Medical Doctor at the Department of Plastic Surgery and Burns Treatment, 
Copenhagen University Hospital, Rigshospitalet 
Søren J Sørensen, Cand. Scient., PhD  
 
 
Professor and Head of the Section of Microbiology, Institute of Biology,  
University of Copenhagen 
 
 
 
 
 

 
 
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Trial Coordinating Unit 
Mathilde Nejrup Hemmingsen, MD, PhD 
Department of Plastic Surgery and Burns Treatment 
Copenhagen University Hospital, Rigshospitalet 
Andreas Larsen, MD, PhD 
Department of Plastic Surgery and Burns Treatment 
Copenhagen University Hospital, Rigshospitalet 
Tim Kongsmark Weltz, MD 
Department of Plastic Surgery and Burns Treatment 
Copenhagen University Hospital, Rigshospitalet 
 
 

 
 
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Data Assessment Committee  
Mathias Ørholt, MD 
Department of Plastic Surgery and Burns Treatment 
Copenhagen University Hospital, Rigshospitalet 
Sebastian Wiberg, MD, PhD 
Department of Anesthesiology and Intensive Care 
Zealand University Hospital, Køge 
An independent biostatistician who will be appointed in the statistical analysis plan (SAP) before 
the assessment committee receives the data. The SAP will be made publicly available before 
inclusion of the last patient, and before unblinding. 
 
 
 
 

 
 
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Site Investigators 
 
 
 
 
 
Clinical Trial Site 
Mikkel Herly, MD 
Department of Plastic Surgery and 
Burns Treatment, Copenhagen 
University Hospital, Rigshospitalet, 
Blegdamsvej 9, 2100 Copenhagen, 
redacted 
 
Lisbet Rosenkrantz Hölmich, Professor, MD, DMSc 
Department of Plastic Surgery, Herlev 
and Gentofte Hospital, Borgmester Ib 
Juuls Vej 1, 2730 Herlev,  
redacted 
 
Nicco Krezdorn, MD, PhD 
Department of Plastic Surgery, Zealand 
University Hospital, Sygehusvej 10, 
4000 Roskilde 
 
Camilla Bille, MD, PhD 
Department of Plastic Surgery, Odense 
University Hospital, J. B. Winsløws Vej 
4, 5000 Odense 
 
redacted 
 
Julie Allen, MD 
Department of Plastic Surgery, Aarhus 
University Hospital, Palle Juul-Jensens 
Boulevard 35, 8200 Aarhus 
 
Lene Birk-Sørensen, MD 
Department of Plastic Surgery, Aalborg 
University Hospital, Søndre Skovvej 3, 
9000 Aalborg 
 
Pharmaceutical manufacturer 
Vancomycin 
Bactocin® 
MIP Pharma GmbH 
Kirkeler Strasse 41 
D-66 440 Blieskastel 
 
Tyskland 
Tlf: (+49) 68 42 96 09 0 
Fax: (+49) 68 42 96 09 35 
Email: info@mip-pharma.de 
Website: www.mip-pharma.de 
 
Cefazolin 

 
 
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Cefazolin “MIP” 
MIP Pharma GmbH 
Kirkeler Strasse 41 
D-66 440 Blieskastel 
Tyskland 
Tlf: (+49) 68 42 96 09 0 
Fax: (+49) 68 42 96 09 35 
Email: info@mip-pharma.de 
Website: www.mip-pharma.de 
 
Gentamicin 
Hexamycin 
Sandoz A/S 
Edvard Thomsens Vej 14 
2300 København S 
Tlf: 63951000 
Fax: 63951001 
Email: info.danmark@sandoz.com 
Website: www.sandoz.dk 
 
Natriumklorid 
Natriumklorid "Fresenius Kabi" 9 mg/ml 
Fresenius Kabi Denmark 
Islands Brygge 57 
2300 København S 
Tlf: 33181600 
Fax: 33181614 
Emailadresse: info-dk@fresenius-kabi.com 
Website: www.fresenius-kabi.com 
 
 
Table of contents 
1. 
Introduction ............................................................................................................................................ 13 
1.1. 
Bacterial contamination of the breast implant ............................................................................. 13 
1.2. 
Local administered antibiotics ....................................................................................................... 13 
1.3. 
Pre-clinical data ............................................................................................................................... 14 
1.4. 
Clinical data ..................................................................................................................................... 14 
1.5. 
Rationale ......................................................................................................................................... 15 
1.6. 
Hypothesis ....................................................................................................................................... 15 
2. 
Experimental design ............................................................................................................................... 15 
2.1. Trial design ........................................................................................................................................... 15 

 
 
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2.2. Outcomes ............................................................................................................................................. 15 
2.2.1. Primary outcome .......................................................................................................................... 15 
2.2.2. Secondary outcomes .................................................................................................................... 16 
2.2.3. Tertiary outcomes ......................................................................................................................... 17 
2.2.3 Additional follow-up ...................................................................................................................... 17 
2.3. Setting and locations ........................................................................................................................... 18 
2.4. Number of Subjects ............................................................................................................................. 19 
2.5. Trial Duration ....................................................................................................................................... 19 
3. 
Subjects eligibility ................................................................................................................................... 19 
3.1. Inclusion criteria .................................................................................................................................. 19 
3.2. Exclusion criteria .................................................................................................................................. 20 
3.3. Pregnancy ............................................................................................................................................. 20 
4. 
Enrollment ............................................................................................................................................... 20 
4.1. Registration .......................................................................................................................................... 20 
4.2. Randomization and treatment assignment ........................................................................................ 21 
4.2.1. Treatment assignment in two-stage breast reconstruction ........................................................ 21 
4.2.2. Treatment assignment if a unilateral patient later becomes bilateral ....................................... 22 
4.3. Registration failures ............................................................................................................................. 22 
4.4. Discontinuation from the trial ............................................................................................................. 22 
4.4.1. Registration of dropouts .............................................................................................................. 22 
4.4.2. Replacement of dropouts ............................................................................................................. 22 
5. 
Treatment procedures ............................................................................................................................ 22 
5.1. Investigational drugs ........................................................................................................................... 23 
5.2. Preparation of the drug solutions ....................................................................................................... 23 
5.2.1. The antibiotic solution .................................................................................................................. 23 
5.2.2. The placebo solution .................................................................................................................... 24 
5.3. Investigational product administration .............................................................................................. 24 
5.4. Dosage adjustments ............................................................................................................................ 24 
5.5. Concurrent medication ........................................................................................................................ 24 
5.6. Blinding ................................................................................................................................................ 24 
5.6.1. Ensuring blinding .......................................................................................................................... 25 
6. 
Data collection ........................................................................................................................................ 25 
6.1. Variables............................................................................................................................................... 25 
6.1.1. Pre-surgery variables .................................................................................................................... 25 

 
 
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6.1.2. Surgical variables .......................................................................................................................... 26 
6.1.3. Post-surgery variables .................................................................................................................. 27 
6.2. Clinical follow-up ................................................................................................................................. 28 
6.3. Data quality and security ..................................................................................................................... 28 
7. 
Assessments of safety and harm ............................................................................................................ 28 
7.1. 
Expected adverse events unrelated to the trial drug .................................................................... 28 
7.2. 
Adverse events possibly related to the trial drug .......................................................................... 29 
7.3. 
Adverse Event Reporting ................................................................................................................ 30 
7.3.1. 
Adverse Events (AE) ................................................................................................................ 30 
7.3.2. 
Serious Adverse Events (SAE) ................................................................................................. 31 
7.3.3. 
Suspected Unexpected Serious Adverse Reactions (SUSARs) ............................................... 31 
7.3.4. 
Severity of Adverse Events ..................................................................................................... 31 
7.3.5. 
Relationship of AE to Trial Intervention ................................................................................. 32 
7.3.6. 
Adverse event reporting during long-term follow-up ........................................................... 32 
8. 
Statistical considerations ........................................................................................................................ 32 
8.1. Sample size ........................................................................................................................................... 32 
8.2. Statistical analysis plan ........................................................................................................................ 32 
8.3. Registration of changes ....................................................................................................................... 33 
9. Ethical considerations ................................................................................................................................. 33 
9.1. Ethical justification .............................................................................................................................. 34 
9.2. Informed consent ................................................................................................................................. 34 
10. Direct access to source data/documentation .......................................................................................... 35 
11. Data management .................................................................................................................................... 35 
12. Quality control and quality assurance ..................................................................................................... 35 
13. Finance and insurance .............................................................................................................................. 36 
14. Publication plan ........................................................................................................................................ 36 
15. Tasks and Responsibilities ........................................................................................................................ 37 
16. Contact information.................................................................................................................................. 37 
17. References ................................................................................................................................................. 39 
18. Appendices ................................................................................................................................................ 44 
 
 
 

 
 
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1. Introduction 
The incidence of breast cancer in Danish women is approximately 4700 per year.1 Many women 
choose to undergo breast reconstruction with an implant following a mastectomy.2 Unfortunately, 
implant-based breast reconstructions are associated with high complication rates. Postoperative 
infection of the breast and implant is one of the most severe short-term complications affecting 
around 5-10 % of the women.3–7 Clinically infected implants must be surgically removed and the 
recovery period that follows is long and agonizing for the women. Subsequent attempts to 
reconstruct the breast are often postponed for several months or abandoned altogether.  
Many strategies to prevent complications associated with bacterial contamination of the breast 
implant have been attempted.8–13 According to a survey made by the American Society of Plastic 
Surgeons, the most widely followed approach is to apply antibiotics directly on the breast implant 
and the dissected tissue pocket to eliminate bacterial contamination during the surgery.14 
Although the use of local antibiotics on breast implants is now widespread, the treatment regimen 
has never been investigated in a randomized controlled trial.15 This protocol will describe a 
randomized controlled trial that will investigate the effect of antibiotics applied locally on the 
implant and in the breast implant pocket on the incidence of infection that leads to explantation 
of the implant. The protocol has been designed in accordance with the SPIRIT 2013 Statement 
guidelines for protocol content.16 
1.1. Bacterial contamination of the breast implant 
The most prevalent bacterial agents associated with breast implant infections are similar to those 
of the breast duct and skin flora which suggests that these are possible sources of 
contamination.17 The most common microorganisms found on infected breast implants are 
Staphylococcus epidermidis and Cutibacterium acnes (previously known as Propionibacterium 
acnes). Other bacteria that have been identified on breast implants are Staphylococcus aureus, 
Pseudomonas aeruginosa and Escherichia coli.18,19  
Previous studies propose that bacterial colonization of breast implants sometimes occur without 
any immediate clinical manifestations.20,21 Instead, bacteria form a chronic, subclinical infection 
which is suspected to play a pivotal role in the development of a protracted immune reaction to 
the implant known as capsular contracture, affecting approximately 10-20 % of the patients.22,23  
1.2. Local administered antibiotics 
Local administration of antibiotics can achieve a high local concentration with a low systemic 
uptake24 and thereby, minimize the systemic side effects while achieving high antibiotic 
penetrance. A high local concentration can ensure optimal effect of the antibiotics at the surgical 
site,25 and thereby decrease the rate of postoperative surgical site infections, while potentially 
minimize the risk of antibiotic resistance. Local antibiotics also have the benefit of being 
independent from the tissue vascularization to achieve peak concentration as opposed to systemic 
antibiotics, which is an advantage during larger surgeries where the vascularization can be 
compromised.25  

 
 
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Studies have shown that the concentration of locally applied antibiotics in the surgical drain 
output is high during the first 24 hours24 and after 72 hours, the concentration is negligible. 
Therefore, it is assumed that the potential side effects to the medication will occur within the first 
72 hours and previous studies have not reported side effects to the local treatment.26 
In 2001, Adams et al recommended an antibiotic regimen consisting of gentamicin, cefazolin 
combined with either bacitracin or vancomycin.27 Internationally, this irrigation regimen has 
become the most commonly used for local breast pocket and implant irrigation.28 In this trial we 
will investigate the combinations of gentamicin, cefazolin and vancomycin for irrigation for the 
breast pocket and breast implant. 
1.3. Pre-clinical data 
Preclinical data from in vitro models suggest that the combination of Gentamicin, Cefazolin and 
Vancomycin is the most efficient treatment against the bacterial species most commonly 
associated with breast implants.27,29 Animal studies suggest that the local application of these 
antibiotics is safe.30–33 
1.4. Clinical data 
Current Evidence – a systematic review 
The regimen of local antibiotics for breast implants and the dissected implant pocket has been 
widely applied in humans14, but few studies have investigated the clinical effect. In May 2020, we 
searched scientific literature databases including Embase, Cochrane, Pubmed and Web of Science. 
We used the following search terms (((breast) AND (implant OR expander OR augmentation OR 
reconstruction)) AND (irrigation OR antibiotics OR antibacterial OR antiinfective OR antimicrobial 
OR disinfection OR bacitracin OR gentamicin OR vancomycin OR cefazolin OR neomycin)) AND 
(infection OR "capsular contracture" OR "capsular contraction" OR capsulitis). We included studies 
and reviews investigating the effect of any local antibiotics for irrigation of the implant and/or 
implant pocket in women undergoing implant-based breast reconstruction or cosmetic breast 
augmentation. Studies that did not list outcomes that were relevant for the primary and 
secondary outcomes of the BREAST-AB trial were excluded. The search identified 1697 studies of 
which 17 studies were included after title/abstract and full text screening. Seven review 
articles,15,34–39 two prospective studies40,41 and eight retrospective studies41–49 were identified. No 
randomized controlled trials were identified. Most of the included studies included solely reported 
on patients undergoing cosmetic augmentation. Two studies included patients undergoing 
cosmetic breast augmentation and breast reconstruction, but they did not stratify the 
outcome.48,49  
Two studies found a significant decrease in the infection rate when applying local antibiotics 
compared to a control group,42,43 whereas one study found no significant decrease.44 These 
studies were limited by the relatively small study populations and a poorly defined outcome and 
none of the studies were blinded. The rate of capsular contracture was found to be significantly 
decreased in two studies,44,45 two studies found no significant decrease,43,46 whereas one study 
found a significant increase in the capsular contracture rate.41 However, all studies investigating 

 
 
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capsular contracture were limited by a short follow-up period for this long-term outcome. No 
adverse events have been reported in any of the included studies, and the local antibiotics were 
generally considered well-tolerated. See appendix 1 for a table of characteristics of the included 
studies.  
1.5. Rationale 
Administration of antibiotics directly on to the breast implant and dissected implant pocket will 
give a high concentration of the antibiotics where they are needed which may prevent bacterial 
contamination of the implant. This may decrease the rate of postoperative infections that lead to 
explantation of the implant and thereby improve the outcome for the patients.  
1.6. Hypothesis 
Local administration of gentamicin, cefazolin and vancomycin on the breast implant will decrease 
the rate of postoperative clinical infections compared to placebo. 
2. Experimental design 
2.1. Trial design 
This trial is an investigator-initiated, randomized, double-blind and placebo-controlled clinical 
phase III trial. The triple antibiotic solution or placebo solution will be applied directly onto the 
implant used for breast reconstruction and the implant pocket. The included subjects who 
undergo bilateral reconstruction will be randomized to the triple antibiotic solution to one of their 
breasts and placebo to the contralateral breast. Those who undergo unilateral reconstruction will 
be randomized to the triple antibiotic solution or the placebo solution. See 4.2 for a more detailed 
description of the randomization. The triple antibiotic solution will consist of 1 g Vancomycin, 1 g 
Cefazolin and 80 mg Gentamicin diluted in 500 mL of saline.27 The placebo solution will consist of 
500 mL of saline. See section 5 for more information on the trial treatment.  
2.2. Outcomes 
2.2.1. Primary outcome 
All-cause explantation of the breast implant within 180 days after the breast reconstruction 
surgery 
Definition 
All-cause explantation will be defined as explantation and discarding of the implant. Replacement 
of an expander with a permanent implant and replacement of a permanent breast implant with a 
new permanent breast implant due to cosmetic revisions such as asymmetry, implant malposition, 
change of size or implant rotation will not be counted as an explantation.  
Rationale 
The rationale for applying local antibiotics is to decrease the risk of severe complications 
associated with the presence of bacteria such as deep surgical site infection that leads to 

 
 
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explantation and discarding of the implant. Postoperative infection that leads to explantation of 
the implant will sometimes occur simultaneously with other complications where the cause of 
explantation may be unclear. Therefore, all-cause explantation is a logical and meaningful primary 
outcome.  
The reason for excluding from the primary outcome: explantations of permanent implants 
followed by replacements with a new permanent implant for cosmetic reasons, is that such 
revisional surgery is not considered a proxy for severe complications that may be associated with a 
deep surgical site infection. 
2.2.2. Secondary outcomes 
The secondary outcomes will include: 
- 
Time to explantation (days) 
- 
All-cause explantation of the breast implant within 1 year after the breast reconstruction 
surgery (Y/N) 
- 
Revision surgery with incision of the fibrous capsule within 180 days after the breast 
reconstruction surgery (Y/N) 
- 
Exchange of permanent implant to expander implant within 180 days after the breast 
reconstruction surgery (Y/N) 
- 
Surgical site infection that leads to antibiotic treatment within 180 days after the breast 
reconstruction surgery (Y/N) 
- 
Infection-specific revision surgery: Revision surgery due to clinically suspected deep 
surgical site infection with surgical access to the breast implant pocket or clinical signs of 
an infection in the breast implant pocket found intraoperatively within 180 days after the 
breast reconstruction surgery (Y/N) 
Definition 
Time to explantation will be defined as the number of days between the breast reconstruction and 
the implant explantation surgery. The breast reconstruction surgery will be defined as the surgery 
where they received the allocated treatment. Surgical site infection will be defined according to 
the CDC classification of surgical site infetion50 leading to antibiotic treatment with oral or 
intravenous antibiotics administered after the surgery. Infection-specific revision surgery will 
follow the same definition as the CDC classification of surgical site infetion50 and may involve a 
positive culture, pus, redness of breast, fever or other signs of infection around the breast implant. 
Rationale 
Time to explantation is important to determine the relation to the breast reconstruction surgery 
and the etiology of the event that leads to explantation of the implant. In some cases, the 
reconstructed breast may be upheld despite complications associated with bacteria by revisional 
surgery and therefore revisional surgery is an outcome of importance. Local antibiotics may 
decrease the incidence of postoperative surgical site infection requiring antibiotic treatment. 
Postoperative swelling and redness are to be expected after a larger surgery and can be difficult to 

 
 
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distinguish from signs of infection. Therefore, surgical site infection that leads to antibiotic 
treatment is a logical outcome. 
Revision surgery due to clinically suspected deep surgical site infection is an important secondary 
outcome to help isolate the effect of the intervention. Some of the explantations in the primary 
outcome (all-cause explantation) are expected to result from ischemia and necrosis of the 
mastectomy flaps due to impaired perfusion, rather than from infection. The intervention (triple 
antibiotic irrigation of the implant and pocket) is designed to reduce the risk of bacterial 
contamination and subsequent deep surgical site infection. It is not expected to influence 
perfusion-related complications. To better separate these mechanisms and to estimate the effect 
of the intervention on infection-related complications, all primary outcome events will undergo 
blinded adjudication to determine whether the indication for revision surgery was consistent with 
deep surgical site infection involving the implant pocket. This adjudicated endpoint will serve as an 
important secondary outcome to isolate the component of the primary outcome that the 
intervention could plausibly modify. 
2.2.3. Tertiary outcomes 
The tertiary outcomes will be assessed for patients undergoing unilateral breast reconstruction. 
The tertiary outcomes will include: 
- 
Time from the breast reconstruction surgery to discharge (days) 
- 
Re-admission within 180 days after the breast reconstruction surgery (Y/N) 
Definition 
Time to discharge will be defined as the amount of days between the breast reconstruction and 
the day of discharge. The breast reconstruction surgery will be defined as the surgery where the 
patient received the allocated treatment.  
Rationale 
The rationale for excluding bilateral patients from the tertiary outcomes is that all bilateral 
patients will receive placebo on one breast and the intervention on the contralateral breast. 
Therefore, patient related outcomes are only applicable for patients who undergo unilateral 
breast reconstruction. Postoperative infection that occurs during the hospital admission can 
prolong the admission period. Application of local antibiotics may shorten the admission period by 
decreasing the rate of postoperative infection occurring during the hospital admission. Infection 
that occurs after discharge can cause re-admission to the hospital. Local antibiotics may decrease 
the infection rate after discharge that require hospitalization.  
2.2.3 Additional follow-up 
The trial will include additional long-term outcomes focused on all-cause incision of the fibrous 
capsule around the breast implant, capsular contracture, Baker classification51 and quality-of-life. 
See Gantt chart figure 1. 
Definition 

 
 
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Capsular contracture and the Baker classification grade will be obtained from the National Patient 
Registry and the patients’ medical journals after 5, 10 and 15 years. The BREAST-Q questionnaire52 
will be used to assess patient-reported outcomes. The patients will be contacted and asked to fill 
out the questionnaire with 5 year-intervals after the surgery. 
Rationale 
Previous studies suggest that bacterial contamination of the breast implant can occur without 
immediate clinical manifestation.20,21 Instead, the bacteria form a chronic, subclinical infection 
which is suspected to play a pivotal role in the development of a protracted immune reaction to 
the implant called capsular contracture, affection 10-20 % of the patients.22,23 The use of local 
antibiotics could potentially decrease the rate of capsular contracture by minimizing the bacterial 
contamination of the implant. Therefore, capsular contracture is a meaningful long-term outcome.  
The application of local antibiotics may decrease the risk of postoperative complications and 
thereby decrease the risk of undergoing revision surgery. This in turn may lead to improved 
patient satisfaction and quality of life. Breast-Q is a validated tool used to quantify patient 
satisfaction and health-related quality of life after breast reconstruction surgery.52  
Patients may be included in additional exploratory substudies at the time of implant explantation 
(e.g. expander removal). The exploratory substudies will be applied for in separate protocols to be 
approved by the relevant authorities and they will not interfere with this trial.  
2.3. Setting and locations 
The trial will be a nationwide multi-center trial with enrollment of patients from the following 
Danish hospitals: 
- 
Department of Plastic Surgery and Burns Treatment, Copenhagen University Hospital, 
Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen 
- 
Department of Plastic Surgery, Herlev and Gentofte Hospital, Borgmester Ib Juuls Vej 1, 
2730 Herlev 
- 
Department of Plastic Surgery, Zealand University Hospital, Sygehusvej 10, 4000 
Roskilde  
- 
Department of Plastic Surgery, Odense University hospital, J. B. Winsløws Vej 4, 5000 
Odense 
- 
Department of Plastic Surgery, Aarhus University Hospital, Palle Juul-Jensens Boulevard 
35, 8200 Aarhus 
- 
Department of Plastic Surgery, Aalborg University Hospital, Søndre Skovvej 3, 9000 
Aalborg 
All sites have clinical experience and expertise in performing implant-based breast 
reconstructions.  

 
 
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2.4. Number of Subjects 
The trial will include patients until a total number of 1274 breast reconstructions according to our 
power calculation. We estimate that this number will be distributed on approximately 1003 
patients provided that approximately 27% of patients undergo bilateral procedures. A total of 637 
breasts will be allocated to placebo and 637 breasts will be allocated to treatment with the local 
antibiotic solution. The statistical considerations behind the sample size calculation is elaborated 
in section 8.1. 
2.5. Trial Duration 
We plan to begin inclusion in January 2021 at Rigshospitalet and Herlev Hospital. The other trial 
sites will begin enrollment thereafter according to the plan outlined below. We expect to begin 
inclusion at Zealand University Hospital in spring 2022, Odense and Aarhus University Hospital in 
autumn 2022, Aalborg University Hospital in spring 2023 followed by South-West Jutland Hospital 
and Hospital Little Belt in the autumn 2023. Additional trial sites may be applied for during the trial 
period if we do not meet our expected aim for included patients. See Gantt chart in figure 1. 
We expect to include the 1003 patients over a 6-year period with planned completion June 2026, 
hence the last follow-up after 180 days will be completed in December 2026. Currently, 700 
women undergo reconstruction with implants each year in Denmark.53 Therefore, we assume that 
it will be feasible to include approximately 334 patients per year. 
Trial site 
Inclusion period 
Expected no. of included 
patients 
Rigshospitalet 
Jan 2021 – June 2026 
222
Herlev Hospital 
Jan 2021 – June 2026 
360
University Hospital Zealand 
Feb 2022 – June 2026 
183
Odense University Hospital 
Oct 2022 – June 2026 
97
Aarhus University Hospital 
Sep 2022 – June 2026 
111
Aalborg University Hospital 
Feb 2023 – June 2026 
30
Total 
 
1003
3. Subjects eligibility 
All trial candidates will be evaluated for suitability by a medical doctor with expertise in the field of 
breast reconstruction surgery. All potential participating patients will receive oral information by 
the medical doctor and all information material will be given to the patient before the written 
informed consent form is signed. See participant timeline in figure 2. 
3.1. Inclusion criteria 
The patients must fulfill all the following criteria to be eligible for inclusion in the trial: 
- 
Age ≥ 18 years 
- 
Biologically female 

 
 
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- 
Signed informed consent 
- 
Scheduled for breast reconstruction with implants or expanders including: 
a. Immediate or delayed reconstructions 
b. Bilateral or unilateral reconstructions 
c. With or without simultaneous flap reconstruction 
3.2. Exclusion criteria 
Patients are considered ineligible if any of the following criteria is fulfilled: 
- 
Pregnancy 
- 
Breast feeding 
- 
Known allergy towards Vancomycin, Gentamicin and Cefazolin 
- 
Known anaphylactic reaction towards other beta-lactam antibiotics or aminoglycosides 
- 
Known allergy towards neomycin 
- 
Known impaired renal function with GFR < 60 mL/min 
- 
Participation in investigational drug trials and projects concerning disinfecting agents in the 
breast implant cavity 
- 
Myasthenia Gravis 
3.3. Pregnancy 
Fertile women with child-bearing potential must provide a negative urine HCG prior to inclusion in 
the trial. 
4. Enrollment 
The patients will be registered in the trial after providing written consent (via the written consent 
form or a digital signature). The registered patients are considered enrolled in the trial when they 
have received the treatment. Each step of the enrollment procedure is described below.    
4.1. Registration 
All patients scheduled for a preoperative visit concerning a breast reconstruction procedure will be 
screened for eligibility and recorded in the individual trial site’s screening log (appendix 2). No 
personal data will be recorded in the screening log. The following variables will be registered in 
the screening: screening number, screening date, initials of the person conducting the screening, 
age of the patient, if available date of pre-operative visit and surgery, eligibility of the patient 
yes/no and if “no”, reason for non-eligibility. All patients who are considered eligible and have 
provided a written consent will be registered in the trial with a letter code for each site (e.g. RH for 
Rigshospitalet) combined with a record ID. The record ID will be assigned in sequential order as 
subjects are registered (1, 2, 3). Registration will include date of registration, central registration 
number, unilateral or bilateral reconstruction, type of surgery (immediate or delayed 
reconstruction) and radiotherapy status. The identification number remains constant throughout 
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4.2. Randomization and treatment assignment 
Registered subjects will be randomized to placebo or the trial drugs on the day of surgery or the 
day before, and they will be considered enrolled in the trial when they have received the trial 
treatment. The randomization number will be the same as the record identification number. All 
patients undergoing unilateral breast reconstruction will be randomized to the trial drug or 
placebo in a ratio of 1:1. All patients undergoing bilateral reconstruction will be randomized to the 
trial treatment on one of their breasts and placebo to the contralateral breast (Investigational 
Product Dosage and Administration, section 5). See figure 3. 
We will use a stratified randomization to ensure that potential risk factors which could confound 
the outcome are evenly distributed in the placebo and intervention group. The randomization 
strata will be generated by the following factors:  
- 
Unilateral or bilateral reconstruction 
- 
Immediate or delayed reconstruction 
- 
Previous radiotherapy and/or planned radiotherapy within the follow-up period (yes/no) 
When the three factors are combined, we get a total of 14 randomization strata per trial site. See 
appendix 3 for an overview of the 14 randomization strata. An allocation sequence will be made 
for each stratum and assign treatment in a fixed block size of two to ensure that the 
investigational drug and placebo is evenly distributed within each stratum. The fixed block size of 
two will not increase the risk of the investigator anticipating the allocation because the 
investigators are blinded to the treatment throughout the trial. 
A member of the trial coordinating unit will access the computer-generated allocation sequence 
via RedCap The allocation will be registered in a REDCap module only available for members of the 
trial coordinating unit, who are unblinded.   
4.2.1. Treatment assignment in two-stage breast reconstruction 
Most implant-based breast reconstructions are performed in a single surgery with a permanent 
breast implant. During the surgery, the surgeon evaluates the quality and vitality of the dissected 
skin flaps before inserting the breast implant. In some patients, the skin quality is not considered 
suitable to allow for insertion of the permanent implant. These patients will be reconstructed in 
two stages, where an expander implant is used in the first surgery. The expander implant is used 
to expand the tissue before it can be replaced with a permanent implant after approximately 3 to 
9 months of expansion. During the first surgery where the expander implant is inserted, the 
patient will be assigned to treatment according the randomization stratum. The allocation 
sequence number will be registered. At the second surgery where the expander is replaced with 
the permanent implant, the same treatment allocation will be used (e.g., if the right breast 
received treatment with the antibiotic solution in the first surgery, the right breast will receive 
treatment with the antibiotic solution in the second surgery). See figure 3. 

 
 
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4.2.2. Treatment assignment if a unilateral patient later becomes bilateral 
In some cases, a unilateral patient can switch to the bilateral set-up. An example could be that a 
patient develops unilateral breast cancer, undergo mastectomy and reconstruction and then later 
in the trial period decide to undergo prophylactic risk-reducing mastectomy and reconstruction of 
the other breast. In this case, the patient would be assigned to either placebo or the trial drug in 
the first surgery. Then, when the patient undergo the second prophylactic surgery on the other 
breast, she will be allocated to receive placebo, if she had received antibiotics in the first surgery 
and vice versa, if she had received placebo in the first surgery she would be allocated to antibiotics 
on the other breast in the second surgery. 
4.3. Registration failures 
Registered subjects who are ineligible for randomization will be recorded as screening failures and 
they will be registered along with the reason for exclusion.  
4.4. Discontinuation from the trial  
Patients who withdraw their informed consent at any point during the trial period will be omitted 
from the trial and registered as “withdrawal of consent”.  The coordinating sponsor investigator 
may omit participants from the trial at any point during the trial period due to safety of the 
participant. There will be no additional follow-up or data collection from these patients. The trial 
treatment is administered as a single dosage and therefore, exclusion will not have any effect on 
the trial treatment. The data analysis in the end of the trial will be performed on a modified 
intention-to-treat population, defined as all randomized patients with a valid informed consent.  
4.4.1. Registration of dropouts  
A designated representative at each trial site will be responsible for contacting the trial 
coordinating unit in case an included subject withdraws consent or is unable to complete the 
follow-up. All excluded patients will be recorded including date, central registration number, 
reason for exclusion and treatment allocation.  Patients excluded from the trial will continue to 
follow the scheduled follow-up visits as a part of the standard treatment. Exclusion from the trial 
will not interfere with the standard treatment or entail any additional procedures or follow-up 
visits. Dropout rates will be monitored continuously by the sponsor-investigator. 
4.4.2. Replacement of dropouts  
Patients who drop out of the trial after enrollment (allocation to trial treatment) will not be 
replaced. The sample size calculation accounts for a drop-out rate of 5 %. In case of a drop-out 
rate of more than 5 %, we will apply imputations by chained equations and repeat the primary 
analysis (for the primary outcome) after imputations.  
5. Treatment procedures 
The trial drug will be administered as a single dosage during the breast reconstructive surgery. The 
administration procedure will be identical for the antibiotic solution and placebo. Only qualified 

 
 
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healthcare personnel will perform the administration of trial drugs and no self-administration will 
take place. All personnel that handles investigational products will be instructed by members of 
the trial coordinating unit. 
5.1. Investigational drugs 
Gentamicin: 40 mg/ml gentamicin sulfate, 2 mL suspension in glass ampoules containing clear, 
colorless suspension without visible particles. Gentamicin is a broad-spectrum, bactericidal 
aminoglycoside primarily targeting gram-negative rods. Gentamicin (Hexamycin) produced by 
Sandoz A/S can be used but other producers of the same drug may be used as an alternative.  
Cefazolin: 2096,72 mg cefazolin natrium equivalent to 2000 mg cefazolin of white or almost white 
powder in a capped vial. Cefazolin is a bactericidal antibiotic targeting both gram-negative and 
gram-positive bacteria. Cefazolin produced by MIP Pharma GmbH can be used but other 
producers of the same drug may be used as an alternative.  
Vancomycin: one capped vial contains vancomycin hydrochloride equivalent to 1000 mg 
vancomycin as a finely grounded white powder with a pink to brown nuance. Vancomycin is 
bactericidal and targets gram-positive bacteria. Vancomycin (Bactocin®) produced by MIP Pharma 
GmbH can be used but other producers of the same drug may be used as an alternative.  
All investigational drugs will be purchased through each trial site’s clinical pharmaceutical services 
and their respective purchasing agreements. The investigational drugs will be kept and prepared in 
accordance with the manufacturer’s recommendations (see ‘summery of product characteristics’ 
for cefazolin, gentamicin and vancomycin. The investigational drugs are part of the standard drug 
selection available at all trial sites. Therefore, we will not account for the overall stock of medicine. 
However, we will account for the use of investigational medicine for each patient enrolled in the 
trial, including batch-number, expiration date, patient registration number and date of 
administration.  
5.2. Preparation of the drug solutions 
The preparation of the trial drug solution will take place in a medication room on the trial site on 
the day of the surgery or day before the surgery. A designated trained nurse will be responsible for 
the preparation and labelling of the trial drug solution. To minimize errors, it will be double 
checked. The labelling will include the trial identification number and marking of which breast the 
treatment will be applied to (right or left). The manufacturing nurse will contact the trial 
coordinating unit to confirm his/her identity as investigational drug manufacturer and obtain 
instruction as to how to allocate the trial treatment. The communication between the Trial 
coordinating unit and the manufacturing nurse will be looped to prevent mistakes regarding the 
allocation. A designated person will deliver the prepared solutions to the operation room, and the 
surgeon and the scrub nurse will be blinded for the allocation. A local SOP describing the 
preparation of the trial drugs will be compiled for each trial site (See appendix 4 for the SOP).  
5.2.1. The antibiotic solution 
The antibiotic solution will contain 1000 mg vancomycin, 80 mg gentamicin and 1000 mg cefazolin. 
Two syringes of 20 mL sterile saline will be drawn from an infusion bag containing 500 mL of 

 
 
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sterile isotonic (9%) saline. The drawn saline will be infused in the capped vials containing 
cefazolin and vancomycin to dissolve the powder. The entire content of the vial containing 
vancomycin (20 mL) will be drawn back into the syringe and reinfused in the infusion bag. Only 10 
mL of the cefazolin solution will be drawn from the capped vial containing the dissolved cefazolin. 
The 10 mL will also be reinfused in the infusion bag. The remaining content the capped vial will be 
discarded as medical waste. Hereafter, the 2 mL gentamicin suspension will be drawn into a 
syringe and infused in the infusion bag already containing vancomycin and cefazolin. See figure 4 
for an illustration of the treatment preparation. 
5.2.2. The placebo solution 
The placebo solution will consist of 500 mL of sterile isotonic (9%) saline contained in a similar 
infusion bag. 
Both the antibiotic solution and the placebo solution will be achromatic and will be 
indistinguishable from one another to ensure blinding of the health care personnel administering 
the drugs. 
5.3. Investigational product administration 
The assigned solution will be administered in an enclosed infusion bag. During the surgery, the 
responsible nurse will draw three 50 ml syringes from the infusion bag (entailing 150 ml) and use it 
to wash the dissected implant pocket. Another 50 ml will be drawn from the same infusion bag 
and used to wash the implant with the assigned solution prior to insertion in the implant pocket. 
The rest of the content in the infusion bag will be discarded as medical waste. Patients undergoing 
unilateral breast reconstruction will receive the assigned solution in one infusion bag marked 
either left or right. The patients undergoing bilateral breast reconstruction will be assigned to the 
antibiotic solution to one breast and placebo solution to the contralateral breast, and the 
allocation sequence will determine which breast (right or left) gets which solution. The assigned 
solution bags will be marked right and left. See appendix 5 for SOP. 
5.4. Dosage adjustments  
The dose of investigational products will be fixed. The drug will be administered as a single dose, 
and one time only. No continuous administration will occur. It will not be possible to adjust the 
treatment after the administration of the treatment. 
5.5. Concurrent medication 
All included patients will be treated according to the local guidelines for breast reconstruction 
surgery at each trial site. The trial intervention will not interfere with any treatment procedures or 
administration of medication.  
5.6. Blinding  
The trial will double-blind so that the patients, site investigators and data monitors will be blinded 
to the allocation. Only the designated nurses and the members of the trial coordinating unit (who 
provide the randomization number and treatment allocation) are not blinded to the allocation. 

 
 
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The unblinded persons will not in any way be part of the treatment, clinical evaluation of 
outcomes or data assessment.  
The intervention drug will be prepared in infusion bags that will be indistinguishable to the 
placebo solution (infusion bags with saline). Both solutions are colorless and identical in 
appearance without any identifying features, and therefore we do not anticipate any risk of 
unintentional unblinding. The designated manufacturing nurse will contact the trial coordinating 
unit to receive the allocation by telephone. The randomization number and the treatment 
allocation will be provided by the trial coordinating unit. An emergency telephone number to the 
trial coordinating unit will be available to access the treatment allocation of individual patients in 
the case where emergency unblinding is necessary. If unblinding should occur, it will be 
documented via the case report form. The unblinded patient will not be excluded from the trial.  
The patients will remain blinded until the end of the additional follow-up period. The rationale for 
keeping the patients blinded is to minimize bias when assessing the long-term outcomes. The 
patients can be unblinded upon request if they withdraw their consent to participate in the trial.  
5.6.1. Ensuring blinding 
The randomization number will ensure that the allocation is given during both surgeries in 
situations where the intervention treatment is repeated, for instance in two stage breast 
reconstruction (see section 4.2.1.) and if a unilateral patient becomes bilateral (see section 4.2.2.). 
During the first surgery, the registration number which equals the randomization number will be 
registered in the case report form. During the second surgery, the manufacturing nurse will 
contact the trial coordinating unit to obtain the treatment allocation and members of the trial 
coordinating unit (who are unblinded) will look up the patient and inform the manufacturing nurse 
of the treatment allocation. The manufacturing nurse will not take part in any treatment 
procedures.  
6. Data collection 
The site investigators, along with members of the trial coordination unit, will be responsible for 
trial related data collection and entry. The individual trial site investigator may delegate 
assignments to designated doctors, scholarship students or nurses registered in the site-specific 
delegation log. Limited trial specific data will be entered into a numbered case report form (see 
appendix 6) at the time of inclusion and the surgery. This along with the screening log will be the 
only source data and all additional data will be obtained from the patients’ medical records. Data 
will be entered directly into REDCap. 
6.1. Variables  
All enrolled patients (i.e. patients who have been assigned to treatment) will be entered into the 
database. An overview of included variables is provided below. 
6.1.1. Pre-surgery variables 
Trial related variables 

 
 
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Study ID 
Site (location) 
Unilateral or bilateral breast reconstruction 
Immediate or delayed breast reconstruction 
Prophylactic or cancer (including carcinoma in situ) 
Radiation therapy status (Y/N) 
Name 
CPR number 
Date and name of data collector 
Patient demographics 
Height (cm) 
Weight (kg) 
Smoking (never, former, active) 
Alcohol consumption (units per week) 
ASA classification (class I-VI) 
Race 
Comorbidities 
Prescription medications 
Oral or intravenous antibiotic treatment within 2 months up to the surgery (Y/N, name and 
dose of antibiotic) 
Prior breast surgery (Y/N, type of surgery, date) 
Radiation therapy (dose and fraction) 
Chemotherapy (type, dose, duration, frequency and no of cycles) 
Antihormonal therapy (type, dose and duration) 
Antibody therapy (type, dose and duration) 
6.1.2. Surgical variables 
Trial related variables 
Date and time of surgery 
Randomization number 
Direct-to-implant or expander breast reconstruction 

 
 
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Deviations from the protocol 
Date and time of treatment administration 
Date and name of the data collector 
Surgery characteristics 
Mesh (Y/N) 
Drain (Y/N) 
Operative time (hours, minutes) 
Implant type (brand, volume, texture, serial no.) 
Implant placement (prepectoral or subpectoral) 
Type of mastectomy procedure (nipple sparring KHAC10 or skin sparring KHAC15) 
Type of reconstruction (KHAE00, KHAE05) 
Thickness of mastectomy flap (mm) 
Pre- and perioperative medications 
VAC (Y/N) 
6.1.3. Post-surgery variables 
Characteristics 
Date of discharge 
Time to drain removal 
Post-operative medication 
Hematoma (Y/N) 
Mastectomy flap necrosis (Y/N) 
Nipple-areola-complex necrosis (Y/N) 
Seroma (Y/N) 
Explantation (Y/N) 
Date of explantation 
Indication of explantation 
Surgical site infection (Y/N) 
Bacterial agent (culturing/PCR) 
Revisional surgery with incision of the fibrous capsule (Y/N) 

 
 
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Date of revisional surgery 
Indication of revisional surgery 
Baker grading 
Local adverse event 
Severity of event 
Time of event 
Treatment/action taken 
Exclusion/loss to follow-up 
Reason for exclusion 
6.2. Clinical follow-up 
The included patients will adhere to the standard follow-up program according to the guidelines of 
the local treatment site. There will no trial specific clinical follow-up visits. The patients will be 
instructed to contact the local treatment site if they should experience adverse events after they 
have been discharged. Additionally, the patients will be instructed to contact us if they receive 
relevant treatment related to the reconstructed breast at another hospital than their primary 
treatment site or via their general practitioner within 180 days after the surgery. 
6.3. Data quality and security 
Each variable is clearly defined in the case report form. Each data field will be provided with a 
definition of the variable, category for categorial variables and units for continuous variables. 
All relevant trial documents including the signed consent form for each patient will be stored in 
the trial master file in a secure, locked place at each individual site. Only the site investigator and 
designated personnel will have access. The trial has been approved by the Danish Data Protection 
Agency. The files will be stored for 25 years, after which they will be destroyed.  
7. Assessments of safety and harm 
Women receiving breast cancer treatment and subsequently undergo breast reconstructive 
surgery are in high risk of experiencing adverse events in relation with the surgical treatment and 
cancer. These adverse events will not be registered as trial drug-adverse events.  
The trial drugs are widely used internationally, and the adverse reaction profile for each drug is 
well-defined. (See ‘Summery of Product Characteristics’ section 4.8 for each drug). Previous 
studies show, that only low levels of locally administered antibiotics enter the bloodstream and 
therefore, the systemic side effects to the trial drugs are expected to be negligible.54  
7.1. 
Expected adverse events unrelated to the trial drug 
The complication rate following breast reconstruction is relatively high, and certain adverse events 
are to be expected after surgical resection of the breast and reconstruction with an implant. 

 
 
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Several postoperative adverse events are likely to occur in the included patients due to the surgery 
and patient comorbidities and these events will not be registered as adverse events related to the 
interventional drugs. The following adverse events are expected in the included patients and will 
not be registered as adverse events to the trial treatment: 
- 
Surgery specific complications: surgical site infection, implant malposition, expander 
deflation, expander port malfunction, implant/expander exposure, implant/expander 
rupture, wound dehiscence, hematoma, flap necrosis, seroma, capsular contracture, nerve 
damage, pain and lymphedema. 
- 
Infectious disease including sepsis without signs of surgical site infection and fever without 
signs of surgical site infection. 
- 
Cardiovascular disease including stroke, acute myocardial infarction, heart failure, 
arrythmia, cardiac arrest, pulmonary embolism, DVT and coagulopathy. 
- 
Gastrointestinal disease including diarrhea, nausea, vomiting, gastroenteritis, colitis and 
ileus. 
- 
Adverse events related to the kidneys and urinary tract including uremia, proteinuria, 
hematuria, interstitial nephritis, upper and lower urinary tract infection and pre-renal and 
post-renal kidney failure.  
- 
Liver- and biliary tract disease including increase in serum liver enzymes levels, increase in 
bilirubin and alkaline phosphatase, hepatitis, liver cirrhosis, cholecystitis and pancreatitis. 
- 
Respiratory disease including dyspnea, pleural effusion, pneumonia, pharyngitis, sinusitis 
and rhinosinusitis.  
- 
Neurological disease including seizures, dizziness, impaired vision and vertigo. 
- 
Metabolic disease including hyperglycemia and hypoglycemia. 
- 
Immunological disease including thrombocytopenia, leukopenia, granulocytopenia, 
agranulocytosis, pancytopenia, leukocytosis, granulocytosis, anemia and polycythemia. 
- 
Psychiatric disease including depression. 
- 
Cancer recurrence. 
7.2. 
Adverse events possibly related to the trial drug 
The presumed relation to the trial drug will be evaluated using the ‘Summery of Product 
Characteristics’ for Gentamicin, Cefazolin and Vancomycin. 
Examples of events that are likely to be related to the trial drugs are:  
Erythema multiforme 
Urticaria 
Angioneurotic edema 

 
 
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Toxic epidermal necrolysis 
Steven Johnsons’ syndrome 
Anaphylactic shock 
Red man syndrome (appearing after a maximum of 10 minutes after administration)  
Acute tinnitus 
Acute deafness  
Drug induced-acute kidney injury 
Myasthenia gravis-like syndrome 
Local adverse events (incl. surgical site infection, skin irritation, erythema, delayed wound 
healing, itching) 
7.3. 
Adverse Event Reporting 
Local antibiotics therapy is considered safe.24 Previous studies have shown that the serum level of 
antibiotics after local application is low,26 and therefore the risk of systemic organ toxicity is low. 
Gentamicin, cefazolin and vancomycin have all been approved for marketing for many years and 
have a well-known systemic adverse reaction profile. The combination of gentamicin, vancomycin 
and cefazolin has been used for local breast pocket irrigation for many years and is considered 
safe.36 Due to the extremely low systemic uptake when using locally administered antibiotics, the 
event of systemic adverse events following the trial intervention is considered very unlikely.  
Adverse events related to the study drug will be assessed continuously by the co-investigator at 
each study site during the admission period (typically 72 hours). The trial drugs have a short half-
life period of maximum 6 hours and will only be administered one time during the surgery. 
Therefore, it is considered very unlikely that adverse events related to the trial drugs should occur 
after discharge. However, adverse events will be monitored and reported for 14 days after 
administration of the study drug. If the patients experience adverse events, the site investigator 
will be responsible for registering the adverse event directly in the case report form. The patients 
will be instructed to contact the local treatment site if they should experience adverse events after 
discharge from the hospital. The site investigator will report all adverse events to the coordinating 
sponsor-investigator who will be responsible for monitoring the safety of the trial. Each adverse 
event will require the investigator to fill in the AE form including the following variables: patient 
identification number, description of event, onset and end of event, severity, relation to the 
intervention, action taken and outcome.  
Any adverse events will be treated according to the local guidelines. 
7.3.1. Adverse Events (AE) and Adverse Reactions (AR) 

 
 
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Any event that occurs after administrations of the trial drug regardless of the relation to the trial 
drug will be defined as an adverse event. Adverse reactions will be defined as events that are 
related to the trial drug.   
7.3.2.  Serious Adverse Events (SAE) and Serious Adverse Reactions (SAR) 
For each recording of adverse event, the event will be evaluated as to whether it was a serious 
adverse event. A SAE will be defined as an AE that is life threatening, results in death, requires 
prolonged hospitalization or results in significant disability.  
The site investigator at each trial site will be responsible for contacting the coordinating sponsor-
investigator in case of serious adverse events within 24 hours of awareness. The site investigator 
will record the event in the case report form.  
All serious adverse reactions will be reported yearly to the Danish Medicines Agency and the 
Regional Ethics Committee by the sponsor-investigator during the study period of three years and 
6 months. After last patient last visit, serious adverse events will no longer be reported annually to 
the Danish Medicines Agency and The Regional Ethics Committee, since the effect of the study 
drug is considered negligible after 30 hours, and it is unlikely that any serious adverse events 
related to the study drug would occur after three days.  
During the long-term follow-up, serious adverse events will not be reported in the annual safety 
report (ASR). Serious adverse events will be registered in the trial and included in a final clinical 
study report after the last long-term follow-up. See Gantt chart figure 1. 
7.3.3. Suspected Unexpected Serious Adverse Reactions (SUSARs) 
A SUSAR is an unexpected and serious presumed reaction to the trial drug. Section 4.8 in the 
‘Summery of Product Characteristics’ for each drug (cefazolin, gentamicin and vancomycin) will be 
used as the reference safety information to determine whether or not the serious adverse event is 
unexpected. The sponsor-investigator will be responsible for that all relevant information about 
SUSARS, which are fatal or life threatening, is recorded and reported to the Regional Health Ethics 
Committee and the Danish Health and Medicines Authority as soon as possible, and no later than 
7 days after the sponsor-investigator has been informed of such an event. No later than 8 days 
after the reporting, the sponsor-investigator is responsible for informing the Regional Health 
Ethics Committee and the Danish Medicines Agency of relevant treatment initiated by the co-
investigator or a doctor at the trial site. Any other SUSAR must be reported to the Regional Health 
Ethics Committee and the Danish Medicines Agency no longer than 15 days after the sponsor-
investigator has been informed. All trial investigators will be informed by the coordinating 
sponsor-investigator in the event of a SUSAR. See Gantt chart figure 1. 
7.3.4. Severity of Adverse Events 
The severity of each adverse event suspected to be related to the trial drug will be graded 
accordingly 

 
 
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- 
Mild: transient symptoms, with no interference in normal daily activity 
- 
Moderate: persistent symptoms, resulting in moderate inhibition of daily activity 
- 
Severe: persistent symptoms, resulting in severe inhibition of daily activity 
7.3.5.  Relationship of AE to Trial Intervention 
For each AE suspected to be related to the trial drug, the probability will be rated accordingly 
- 
Probable: there is good reason and adequate documentation to assume causal relationship 
- 
Possible: a causal relationship is likely and cannot be dismissed  
- 
Unlikely: the event is most likely related to an etiology other than the intervention 
- 
Unknown: causality is not assessable 
7.3.6. Adverse Reactions reporting during long-term follow-up 
The annual reporting of SAR will not apply during the long-term follow-up period. Serious adverse 
reactions that we learn of during the long-term follow-up period of 5, 10 and 15 years will be 
recorded and included in a final clinical study report after the last long-term follow up.  
SUSARS will be reported continuously to the Danish Medical Agency throughout the long-term 
follow-up period. See Gantt chart in figure 1. 
8. Statistical considerations 
8.1. Sample size  
The trial will be powered towards the primary outcome. Previous data3 do not suggest that there 
is an overrepresentation of bilateral infections compared to the unilateral infection rate which 
suggests that infections may be randomly distributed. Therefore, we do not assume that infections 
are correlated between breasts within the same patient. However, due to the paired design in the 
patients that undergo bilateral reconstruction, any correlation between the individual patient’s 
breasts will increase the statistical power of this trial. The independent sampling unit of this trial 
will be ‘breast’, and the trial will be powered towards ‘number of breasts’, so that the final 
number of included patients will depend on the proportion of patients undergoing bilateral breast 
reconstruction. The incidence of the primary outcome is reported at 10%. With an α-level of 0.05, 
the trial will have a power of 0.90 to detect an absolute risk reduction of 5% if 1158 ‘breasts’ are 
included. We will include patients, until a total number of 1274 breasts have completed the 
follow-up period of 180 days to account for a dropout rate of 10%. We estimate that 1003 patients 
will be included in the trial if approximately 27% of the patients undergo bilateral breast 
reconstruction. 
8.2. Statistical analysis plan 
The statistical analyses will be conducted on a modified intention-to-treat population, defined as 
all randomized patients with a valid informed consent. Categorical variables will be presented as 
frequencies whereas normally distributed continuous variables will be presented as mean ± SD, 

 
 
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and as median (25th percentile-75th percentile) if non-normally distributed. Differences in 
endpoints (including the primary outcome) between the treatment allocations will be analyzed 
using multivariable logistic regression with a generalised estimating equation (GEE) that takes 
clustering into account adjusted for stratification variables. The stratified randomization approach 
will ensure an even distribution of known outcome risk factors between the placebo group and 
the treatment group. In case of missingness greater than 5% for the primary outcome, we will 
apply multiple imputations by chained equations and repeat the primary analysis as sensitivity 
analysis. A statistical significance level of 0.05 will be applied throughout. The open source 
statistical program “R” (http://www.r-project.org) will be used for data treatment and statistical 
analysis. A separate statistical analysis plan (SAP) will describe the detailed analysis plan, and it will 
be made publicly available before inclusion of the last patient, and before any unblinding of data. 
8.3. Registration of changes 
Changes to the original statistical analysis plan will be recorded in the sponsor’s trial master file 
before unblinding.  
8.4. Rationale for model selection 
Based on extensive simulations published in the separate SAP, we have selected a multivariable 
logistic regression with a generalised estimating equation (GEE) with an exchangeable correlation 
structure to analyze the primary outcome. The multivariable logistic regression model is chosen as 
the primary outcome is binary. The model can adjust for the randomization strata and other 
potential confounders to control for residual imbalances in the baseline parameters. Using a 
generalized estimating equation (GEE) is necessary to account for correlation between the two 
breasts nested within a patient undergoing bilateral reconstruction. The GEE method models the 
population treatment effect which has a more appealing interpretation than random effects 
models which are subject specific/within subject interpretation. The GEE would likely gain more 
efficacy from the unilateral patients with no clustering whereas the random effects model could 
become unstable due to singularity and random effects variances near or equal to zero. 
 
9. Ethical considerations 
This trial will be conducted in accordance with EU and national legislation on medical research in 
capable patient volunteers. Eligible subjects shall provide oral and written informed consent to 
participate in the trial. The informed consent can be withdrawn by the participant at any time 
during the trial after which the patient will convert to receiving treatment as determined by local 
guidelines. All data on trial participants will be protected according to the General Data Protection 
Regulation (GDPR), the data protection law and the Danish Health Act. The project is approved by 
the Danish Data Protection Agency and is to be approved by the Danish Medicines Agency and the 
Regional Committee on Health Research Ethics. The trial will be conducted according to national 
and international standards of good clinical practice (GCP) and will be monitored by the regional 
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9.1. Ethical justification 
The trial will investigate the beneficial effects and potential side-effects of applying gentamicin, 
vancomycin and cefazolin locally onto the breast implant during breast reconstruction surgery. 
This may limit bacterial contamination of the implant and thereby decrease the risk of 
postoperative infection which is associated with a poor outcome for the patients. Therefore, 
participation in this trial could benefit the individual participant. 
Inclusion in the trial may benefit the individual subject by decrease the risk of undergoing 
explantation of the implant, minimizing the risk of postoperative infection, minimize the 
hospitalization period and may as well improve the outcome for future women undergoing 
implant-based breast reconstructive surgery. Alternatively, we may find that the local antibiotics 
do not have a clinically relevant effect and perhaps negative side-effects that should be explored 
further. 
The trial drug regimen is widely used internationally14 but the potential positive and/or negative 
effects of using local antibiotics on breast implants have never been tested against placebo in a 
randomized trial. See appendix 1 for a review of the current literature.  
Though the drug regimen has not been tested in a randomized controlled trial, the drugs have 
been applied by plastic surgeons for several years, and no adverse events has been 
reported.42,44,48,55 Therefore, the drug regimen is expected to be of minimal risk to the subjects in 
the trial. Moreover, the systemic levels of antibiotics after locally applied antibiotics has been 
shown to be much lower than the levels seen with systemic antibiotics and the trial treatment 
consists of a single dose, and therefore we do not expect systemic adverse reactions to the trial 
drugs.36   
Currently, no clinical guidelines exist in Denmark regarding the prophylactic use of local antibiotics 
to breast implants, and the treatment depends on the local approach at each hospital and the 
individual surgeon’s preference. Allocation to placebo in this trial is therefore considered ethically 
acceptable. Application of local vancomycin on the breast implant has been used routinely at the 
Department of Plastic Surgery, Herlev and Gentofte Hospital, in the past years. This treatment 
regimen is not based on any evidence and is scientifically unjustified. Therefore, we find it ethically 
acceptable to include patients from Herlev and Gentofte Hospital in the trial. All eligible patients 
from Herlev and Gentofte Hospital will receive this information before providing consent and 
specific written patient information material will be provided for these patients. Patients at Herlev 
and Gentofte Hospital who are not included in the trial will receive local vancomycin during the 
breast reconstruction surgery. 
The results from this trial could change the guidelines for breast reconstruction surgery on an 
international level and be used to provide patients with evidence-based treatment. 
9.2. Informed consent 
Registered patients will receive information about the trial in their e-boks. They will be informed 
that the trial coordinating unit will contact them to provide oral information about the project 
after they have had time to read the information material about the trial. The contact information 
for registered patients will be passed on to the trial coordination unit from the treatment site.   

 
 
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Recruitment of trial participants will be carried out at the time of the preoperative patient visit or 
by telemedicine (i.e. telephone or a secure video connection) by a medical doctor with relevant 
expertise. All patients are encouraged to bring a third party (i.e. relative or partner) to this 
appointment. The responsible medical doctor can assign a designated nurse or medical student 
with relevant expertise to provide the patient with both oral and written information concerning 
the trial during this visit as the medical doctor has limited time available at the initial pre-operative 
consultation. The investigator carrying out the recruitment will be responsible for obtaining the 
informed consent (either by a digital consent or a written consent form) from the patients prior to 
any protocol-related activities. The conversation will take place in a private room behind a closed 
door. Participation in the trial will not influence the choice of treatment. The patient and the 
responsible medical doctor must personally provide a dated signature digitally or on a consent 
form. The informed consent can be withdrawn by the patient at any time and without explanation, 
after which the patient will receive the standard treatment according to the local guidelines. No 
personal data will be collected patients before informed consent is obtained. 
9.2.1. General considerations 
We will strive to provide the patients with at least 24 hours of consideration, but in some patients 
this will not be possible. For instance, when it comes to patients undergoing primary breast 
reconstruction, the breast reconstruction is performed during the same surgery as the cancer 
surgery and the patients are treated in an accelerated cancer treatment course. Due the short 
period of time from planning to carrying out the surgery, the decisions regarding possible use of 
implants or expander for reconstruction are often made a few hours before the surgery. In these 
cases, the patients will have at least 2 hours of consideration. 
10. Direct access to source data/documentation 
The site investigator will permit direct access to source data blinded for treatment allocation for 
monitoring, audits and reviews by the Health Ethics Committee, Good Clinical Practice unit, Danish 
Medicines Agency and other regulatory authorities. 
11. Data management 
All data management will be conducted according to guidelines of the Danish Data Protection 
Agency. The data will be kept in REDCap. The database will be maintained for 25 years from the 
last patient visit and anonymized when the approval from the Danish Data Protection Agency 
terminates. 
12. Quality control and quality assurance 
The trial will be conducted according to the approved protocol and will comply to standard 
procedures for quality control and quality assurance. The investigator at each trial site will report 
any deviations from standard protocol to the coordinating sponsor-investigator either by direct 
contact or via the case report form. 

 
 
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The trial conduct, data generation, data documentation and reporting will be in accordance with 
ICH-GCP guidelines and the trial will be monitored by the national Good Clinical Practice (GCP) 
unit. Monitoring will be conducted upon initiation of the trial, during the trial and at termination 
of the trial.  
The sponsor-investigator, local trial site investigators and the trial coordinating unit are 
responsible for maintaining up-to-date accrual information, enrollment status and safety data. It is 
the responsibility of the sponsor-investigator to ensure oversight of trial related activities and on a 
yearly basis, report trial progression, enrollment status and safety data to the Trial Steering 
Committee (see Trial Steering Committee Charter). The sponsor-investigator will submit all 
relevant documents to the board members for scientific progress review. The sponsor-investigator 
is responsible for ensuring that access to clinical trial data is consistent with data protection 
principles and in accordance with the patients’ informed consent provided in relation to their 
participation in the clinical trial. 
The trial steering committee will be responsible for data monitoring and quality control of the data 
extracted from the patients’ medical journals at the long-term follow-up after 5, 10 and 15 years.  
13. Finance and insurance 
The trial is funded by a project grant in surgical research of 2,975,000 DKK from the Novo Nordisk 
Foundation. The grant budget will cover a PhD salary, a part-time post-doc salary, and medicine 
and materials required for the trial. See attached research budget. The grant is disbursed to 
Professor Tine Engberg Damsgaard on behalf of Rigshospitalet and administered by the Financial 
Department of the Centre of Head and Orthopedics, Rigshospitalet. None of the researchers have 
any financial disclosures or relation to the Novo Nordisk Foundation. The Novo Nordisk 
Foundation have had no part in the design of the study, and they will not participate in the 
reporting of the results. The study participants will not be reimbursed for participation in the 
study. The trial participants are insured according to the Danish patient compensation scheme. 
14. Publication plan 
The trial is registered on EudraCT. The trial protocol will be registered at ClinicalTrials.gov before 
enrollment of the first patient. The protocol will be published prior to unblinding of the results in a 
methodology article including the statistical analysis plan. The main article will include the primary 
and secondary outcomes prespecified in the SAP. The tertiary and long-term outcomes will be 
included in subsequent articles. The manuscripts will be used to report the results of the trial to 
the scientific community and will adhere to the CONSORT guidelines.56 The members of the trial 
coordinating unit will be co-first authors and the coordinating sponsor-investigator will be 
senior/last author and corresponding author. All site investigators and members of the Trial 
Steering Committee will be co-authors. Other co-authorships will be decided by contribution 
according to the ICMJE authorship guidelines57 depending on personal involvement. All 
publications will refer to the trial group which will include all contributing parties to the BREAST-
AB trial. The manuscripts will be submitted to peer-reviewed international journals and both 

 
 
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positive, negative and inconclusive results will be published. The findings of the trial will be shared 
with participating sites and presented at national and international conferences. The results will 
be disseminated to the public but will not be shared directly with participating patients. See Gant 
chart in figure 1. 
15. Tasks and Responsibilities 
Trial Coordinating Unit: Protocol development, daily management in the trial period, contact to 
Good Clinical Practice monitoring unit, contact to trial sites, data dictionary development, 
responsible for providing randomization sequences for each trial site, provide deidentified data to 
the trial steering committee for safety monitoring, available for unblinding the treatment 
allocation of individual patients in the case of an emergency, instructing health care personnel 
involved in the trial, data collection and management. 
Coordinating Sponsor-Investigator: Overall responsibility for protocol development, funding, 
budget overview, ethical approval, trial registration, trial oversight (including enrollment trends 
and safety), contact to Good Clinical Practice monitoring unit, potential recruitment of additional 
sites, and dissemination and presentation of results. 
Trial Steering Committee: Clinical and scientific advising to the sponsor-investigator, evaluation 
and recommendations based on yearly reports regarding enrollment trends, progress and safety 
of the trial, counseling regarding scientific reporting of data, data quality control during long-term 
follow-up. See ‘Trial Steering Committee Charter’ for a more thorough description of the tasks and 
responsibilities of the committee. 
Site investigators: Responsible for site-specific enrollment, evaluation and reporting of eligible 
patients not included, education of personnel at trial sites, reporting of site-specific issues or 
challenges to the coordinating sponsor-investigator, inclusion of patients, responsible for 
obtaining informed consent, contact to the regional Good Clinical Practice monitoring unit, trial 
related data entry in the case report form 
Clinical personnel: Preparation and administration of the trial drugs. 
Good Clinical Practice-unit: See section 12. 
Data Assessment Committee: Assessment and analysis of data. 
16. Contact information 
Contact for public queries 
Mathilde Nejrup Hemmingsen, MD 
Department of Plastic Surgery and Burns Treatment 
Email: redacted 
Phone: redacted 

 
 
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Contact for scientific queries 
Mikkel Herly, MD 
Department of Plastic Surgery and Burn Treatments 
Blegdamsvej 9, DK2100 Copenhagen 
E-mail: redacted 
Phone: redacted 
 
 
 
 
 
 

 
 
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17. References 
1.  
Bekæmpelse K. Statestik om brystkræft. 
2.  
2018 Plastic Surgery Statistics. 
3.  
Coroneos CJ, Selber JC, Offodile AC, Butler CE, Clemens MW. US FDA breast implant 
postapproval studies: long-term outcomes in 99,993 patients. Ann Surg. 2019;269(1):30-36. 
4.  
Stevens WG, Calobrace MB, Harrington J, Alizadeh K, Zeidler KR, d’Incelli RC. Nine-year core 
study data for Sientra’s FDA-approved round and shaped implants with high-strength 
cohesive silicone gel. Aesthet Surg J. 2016;36(4):404-416. 
5.  
Patrick Maxwell G, Van Natta BW, Bengtson BP, Murphy DK. Ten-year results from the 
natrelle 410 anatomical form-stable silicone breast implant core study. Aesthetic Surg J. 
2015;35(2):145-155. doi:10.1093/asj/sju084 
6.  
Petersen A, Eftekhari ALB, Damsgaard TE. Immediate breast reconstruction: A retrospective 
study with emphasis on complications and risk factors. J Plast Surg Hand Surg. 
2012;46(5):344-348. doi:10.3109/2000656X.2012.700025 
7.  
Dikmans REG, Negenborn VL, Bouman M-B, et al. Two-stage implant-based breast 
reconstruction compared with immediate one-stage implant-based breast reconstruction 
augmented with an acellular dermal matrix: an open-label, phase 4, multicentre, 
randomised, controlled trial. Lancet Oncol. 2017;18(2):251-258. 
8.  
Chopra K, Gowda AU, McNichols CHL, Brown EN, Slezak S, Rasko Y. Antimicrobial 
Prophylaxis Practice Patterns in Breast Augmentation. Ann Plast Surg. 2017;78(6):629-632. 
doi:10.1097/sap.0000000000000942 
9.  
Yalanis GC, Liu E-W, Cheng H-T. Efficacy and safety of povidone-iodine irrigation in reducing 
the risk of capsular contracture in aesthetic breast augmentation: a systematic review and 
meta-analysis. Plast Reconstr Surg. 2015;136(4):687-698. 
10.  
Kenna DM, Irojah BB, Mudge KL, Eveler K. Absorbable antibiotic beads prophylaxis in 
immediate breast reconstruction. Plast Reconstr Surg. 2018;141(4):486e-492e. 
doi:10.1097/PRS.0000000000004203 
11.  
Nava MB, Catanuto G, Rocco N. Role of Mitomycin C in Preventing Capsular Contracture in 
Implant-Based Reconstructive Breast Surgery: A Randomized Controlled Trial. Plast Reconstr 
Surg. 2017;140(6):823e-824e. doi:10.1097/PRS.0000000000003851 
12.  
Hunsicker LM, Chavez-Abraham V, Berry C, McEwen D. Efficacy of vancomycin-based 
continuous triple antibiotic irrigation in immediate, implant-based breast reconstruction. 
Plast Reconstr Surg - Glob Open. 2017;5(12). doi:10.1097/GOX.0000000000001624 
13.  
Tutela JP, Duncan DP, Kelishadi SS, Chowdhry S, Boyd T, Little JA. Continuous Postoperative 
Antibiotic Irrigation via Catheter System Following  Immediate Breast Reconstruction. 
Eplasty. 2015;15:e49. 
14.  
Hidalgo DA, Sinno S. Current trends and controversies in breast augmentation. Plast 

 
 
Version 3.0 
 
 
November 20th, 2025 
40 
Reconstr Surg. 2016;137(4):1142-1150. 
15.  
Lynch JM, Sebai ME, Rodriguez-Unda NA, Seal S, Rosson GD, Manahan MA. Breast pocket 
irrigation with antibiotic solution at implant insertion: a systematic review and meta-
analysis. Aesthetic Plast Surg. 2018;42(5):1179-1186. 
16.  
Chan A-W, Tetzlaff JM, Altman DG, et al. SPIRIT 2013 statement: defining standard protocol 
items for clinical trials. Ann Intern Med. 2013;158(3):200-207. 
17.  
Pittet B, Montandon D, Pittet D. Infection in breast implants. Lancet Infect Dis. 2005;5(2):94-
106. doi:10.1016/S1473-3099(05)01281-8 
18.  
Bartsich S, Ascherman JA, Whittier S, Yao CA, Rohde C. The breast: a clean-contaminated 
surgical site. Aesthetic Surg J. 2011;31(7):802-806. doi:10.1177/1090820X11417428 
19.  
Ahn CY, Ko CY, Wagar EA, Wong RS, Shaw WW. Microbial evaluation: 139 implants removed 
from symptomatic patients. Plast Reconstr Surg. 1996;98(7):1225-1229. 
doi:10.1097/00006534-199612000-00016 
20.  
Pajkos A, Deva AK, Vickery K, Cope C, Chang L, Cossart YE. Detection of subclinical infection 
in significant breast implant capsules. Plast Reconstr Surg. 2003;111(5):1605-1611. 
21.  
Rieger UM, Mesina J, Kalbermatten DF, et al. Bacterial biofilms and capsular contracture in 
patients with breast implants. Br J Surg. 2013;100(6):768-774. 
22.  
Benediktsson K, Perbeck L. Capsular contracture around saline-filled and textured 
subcutaneously-placed implants in irradiated and non-irradiated breast cancer patients: 
Five years of monitoring of a prospective trial. J Plast Reconstr Aesthetic Surg. 
2006;59(1):27-34. doi:10.1016/j.bjps.2005.08.005 
23.  
Calobrace MB, Stevens WG, Capizzi PJ, Cohen R, Godinez T, Beckstrand M. Risk factor 
analysis for capsular contracture: A 10-year sientra study using round, smooth, and textured 
implants for breast augmentation. Plast Reconstr Surg. 2018;141(4S):20S-28S. 
doi:10.1097/PRS.0000000000004351 
24.  
White IV RR, Pitzer KD, Fader RC, Rajab MH, Song J. Pharmacokinetics of topical and 
intravenous cefazolin in patients with clean surgical wounds. Plast Reconstr Surg. 
2008;122(6):1773-1779. 
25.  
Berberich C, Sanz-Ruiz P. Risk assessment of antibiotic resistance development by antibiotic-
loaded bone cements: Is it a clinical concern? EFORT Open Rev. 2019;4(10):576-584. 
doi:10.1302/2058-5241.4.180104 
26.  
Sweet FA, Roh M, Sliva C. Intrawound application of vancomycin for prophylaxis in 
instrumented thoracolumbar fusions: efficacy, drug levels, and patient outcomes. Spine 
(Phila Pa 1976). 2011;36(24):2084-2088. 
27.  
Adams Jr WP, Conner WCH, Barton Jr FE, Rohrich RJ. Optimizing breast-pocket irrigation: 
the post-betadine era. Plast Reconstr Surg. 2001;107(6):1596-1601. 
28.  
Epps MT, Langsdon S, Pels TK, et al. Pocket Irrigation and Technique During Reconstructive 
Surgery: An American Society of Plastic Surgery Survey of Current Practice. Ann Plast Surg. 

 
 
Version 3.0 
 
 
November 20th, 2025 
41 
2019;82(6S Suppl 5):S427-S432. doi:10.1097/SAP.0000000000001790 
29.  
Adams WP, Conner WCH, Barton FE, Rohrich RJ. Optimizing breast pocket irrigation: an in 
vitro study and clinical implications. Plast Reconstr Surg. 2000;105(1):334-338. 
30.  
Darouiche RO, Meade R, Mansouri MD, Netscher DT. In vivo efficacy of antimicrobe-
impregnated saline-filled silicone implants. Plast Reconstr Surg. 2002;109(4):1352-1357. 
doi:10.1097/00006534-200204010-00022 
31.  
Zebala LP, Chuntarapas T, Kelly MP, Talcott M, Greco S, Riew KD. Intrawound vancomycin 
powder eradicates surgical wound contamination: an in vivo  rabbit study. J Bone Joint Surg 
Am. 2014;96(1):46-51. doi:10.2106/JBJS.L.01257 
32.  
Yarboro SR, Baum EJ, Dahners LE. Locally administered antibiotics for prophylaxis against 
surgical wound infection. An in vivo study. J Bone Joint Surg Am. 2007;89(5):929-933. 
doi:10.2106/JBJS.F.00919 
33.  
Cavanaugh DL, Berry J, Yarboro SR, Dahners LE. Better prophylaxis against surgical site 
infection with local as well as systemic antibiotics. An in vivo study. J Bone Joint Surg Am. 
2009;91(8):1907-1912. doi:10.2106/JBJS.G.01237 
34.  
Frois AO, Harbour PO, Azimi F, et al. The role of antibiotics in breast pocket irrigation and 
implant immersion: a systematic review. Plast Reconstr Surg Glob Open. 2018;6(9). 
35.  
Drinane JJ, Chowdhry T, Pham T-H, et al. Examining the Role of Antimicrobial Irrigation and 
Capsular Contracture: A  Systematic Review and Meta-analysis. Ann Plast Surg. 
2017;79(1):107-114. doi:http://dx.doi.org/10.1097/SAP.0000000000001134 
36.  
Campbell CA. The Role of Triple-Antibiotic Saline Irrigation in Breast Implant Surgery. Ann 
Plast Surg. 2018;80(6S Suppl 6):S398-S402. doi:10.1097/SAP.0000000000001345 
37.  
Horsnell JD, Searle AE, Harris PA, et al. Intra-operative techniques to reduce the risk of 
capsular contracture in patients undergoing aesthetic breast augmentation - A review. 
Surgeon. 2017;15(5):282-289. doi:http://dx.doi.org/10.1016/j.surge.2017.03.001 
38.  
Huang N, Liu M, Yu P, Wu J. Antibiotic prophylaxis in prosthesis-based mammoplasty: a 
systematic review. Int J Surg. 2015;15:31-37. 
39.  
Samargandi OA, Joukhadar N, Al Youha S, Thoma A, Williams J. Antibiotic Irrigation of 
Pocket for Implant-Based Breast Augmentation to Prevent  Capsular Contracture: A 
Systematic Review. Plast Surg (Oakville, Ont). 2018;26(2):110-119. 
doi:10.1177/2292550317747854 
40.  
Burkhardt BR, Dempsey PD, Schnur PL, Tofield JJ. Capsular contracture: a prospective study 
of the effect of local antibacterial agents. Plast Reconstr Surg. 1986;77(6):919-932. 
41.  
Stevens WG, Nahabedian MY, Calobrace MB, et al. Risk factor analysis for capsular 
contracture: a 5-year Sientra study analysis using round, smooth, and textured implants for 
breast augmentation. Plast Reconstr Surg. 2013;132(5):1115-1123. 
42.  
Araco A, Gravante G, Araco F, Delogu D, Cervelli V, Walgenbach K. Infections of breast 
implants in aesthetic breast augmentations: a single-center review of 3,002 patients. 

 
 
Version 3.0 
 
 
November 20th, 2025 
42 
Aesthetic Plast Surg. 2007;31(4):325-329. 
43.  
Pfeiffer P, Jørgensen S, Kristiansen TB, Jørgensen A, Hölmich LR. Protective effect of topical 
antibiotics in breast augmentation. Plast Reconstr Surg. 2009;124(2):629-634. 
44.  
Giordano S, Peltoniemi H, Lilius P, Salmi A. Povidone-iodine combined with antibiotic topical 
irrigation to reduce capsular contracture in cosmetic breast augmentation: a comparative 
study. Aesthetic Surg J. 2013;33(5):675-680. 
45.  
Blount AL, Martin MD, Lineberry KD, Kettaneh N, Alfonso DR. Capsular contracture rate in a 
low-risk population after primary augmentation mammaplasty. Aesthetic Surg J. 
2013;33(4):516-521. 
46.  
Drinane JJ, Bergman RS, Folkers BL, Kortes MJ. Revisiting triple antibiotic irrigation of breast 
implant pockets: A placebo-controlled single practice cohort study. Plast Reconstr Surg - 
Glob Open. 2013;1(7). doi:10.1097/GOX.0b013e3182aa8760 
47.  
Drinane JJ, Kortes MJ, Bergman RS, Folkers BL. Evaluation of antibiotic irrigation versus 
saline irrigation in reducing the long-term incidence and severity of capsular contraction 
after primary augmentation mammoplasty. Ann Plast Surg. 2016;77(1):32-36. 
48.  
Adams WPJ, Rios JL, Smith SJ. Enhancing patient outcomes in aesthetic and reconstructive 
breast surgery using  triple antibiotic breast irrigation: six-year prospective clinical study. 
Plast Reconstr Surg. 2006;117(1):30-36. 
49.  
Gutowski KA, Mesna GT, Cunningham BL. Saline-filled breast implants: A Plastic Surgery 
Educational Foundation multicenter outcomes study. Plast Reconstr Surg. 
1997;100(4):1019-1027. doi:10.1097/00006534-199709001-00028 
50.  
Horan TC, Gaynes RP, Martone WJ, Jarvis WR, Emori TG. CDC Definitions of Nosocomial 
Surgical Site Infections, 1992: A Modification of CDC Definitions of Surgical Wound 
Infections. Infect Control Hosp Epidemiol. 1992;13(10):606-608. doi:10.1086/646436 
51.  
Spear SL, Baker JJL. Classification of capsular contracture after prosthetic breast 
reconstruction. Plast Reconstr Surg. 1995;96(5):1119-1123; discussion 1124. 
52.  
Pusic AL, Klassen AF, Scott AM, Klok JA, Cordeiro PG, Cano SJ. Development of a new 
patient-reported outcome measure for breast surgery: the BREAST-Q. Plast Reconstr Surg. 
2009;124(2):345-353. 
53.  
Landspatientsregisteret: Avanceret udtræk. 
54.  
Zalavras CG, Patzakis MJ, Holtom P. Local antibiotic therapy in the treatment of open 
fractures and osteomyelitis. Clin Orthop Relat Res. 2004;427:86-93. 
55.  
Samargandi OA, Joukhdar N, Shaikh OM, Al Youha S, Williams J. Role of Antibiotic Irrigation 
in Preventing Capsular Contracture and Other Complication After Breast Augmentation: A 
Systematic Review and Meta-analysis. Plast Reconstr Surg Glob Open. 2016;4(9 Suppl). 
56.  
Schulz KF, Altman DG, Moher D. CONSORT 2010 statement: Updated guidelines for 
reporting parallel group randomised trials. Int J Surg. 2011;9(8):672-677. 
doi:10.1016/j.ijsu.2011.09.004 

 
 
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43 
57.  
International Committee of Medical Journal Editors (ICMJE). International Committee of 
Medical Journal Editors (ICMJE) Recommendations for the Conduct, Reporting, Editing and 
Publication of Scholarly Work in Medical Journals: Sample References. 2009;88(May):1-19. 
 
 
 

 
 
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18. Appendices 
Appendix 1: Systematic review 
Appendix 2: Screening log 
Appendix 3: Randomization strata 
Appendix 4: Standard operating form for preparation of investigational drugs 
Appendix 5: Standard operating form for administration of investigational drugs 
Appendix 6: Case report forms 
Appendix 7: Medicine account 
Appendix 8: Trial Steering Committee Charter 
Figure 1: Gantt chart 
Figure 2: Participant timeline 
Figure 3: Patients 
Figure 4: Preparation of treatment