The Role of Adherent Occlusive Antimicrobial Absorbent Foam Dressing in Prevention of Cesarean Section Wound Complications
Phase: NA
Conditions: Cesarean Section; Complications, Wound, Dehiscence
Sponsor: Loyola University

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# 207526 
Date 6/3/2019 
 
The Role of Adherent Occlusive Antimicrobial Absorbent Foam Dressing in 
Prevention of Cesarean Section Wound Complications 
 
       
Background and Significance: 
 
Cesarean delivery rates continue to increase in the United States, accounting for 
33% of all births in 2011 (1). Patients undergoing cesarean delivery are at a greater 
risk of postpartum infection when compared to vaginal delivery. Additionally, the 
most prominent risk factor for postpartum infection is cesarean delivery.  The 
spectrum of puerperal infections ranges from surgical site infections (SSI), 
endometritis, and abscess to pelvic thrombophlebitis, bacteremia, and sepsis (2).  
2.5-16% wound complication post csection which includes seroma, hematoma, 
infection , separation and dehiscence. Risk factors for wound complication include 
medical disorders such as diabetes, tobacco use, preeclampsia, obesity, frequent 
vaginal exams, internal monitoring and emergent cesarean. (3) Reported rates of 
post-cesarean wound infection range from 2.71-11.4% (4-8).  Risk factors for post-
cesarean SSIs include prolonged operating time, body mass index (BMI) greater 
than 30, and increased thickness of subcutaneous tissue (5,6).  Furthermore, 
patients undergoing cesarean delivery experience increased risk of 
rehospitalization within 30 days postpartum, as the majority of SSIs become 
apparent following discharge (9, 10). SSI is the principal reason for readmission 
following cesarean delivery (9).   
 
Wound infection is an economic and social burden to the health care system.  Of the 
major health care-associated infections—central line-associated bloodstream 
infection, ventilator-associated pneumonia, SSI, Clostridium difficile infection, and 
catheter-associated urinary tract infection—SSI contributes the most to the total 
annual cost of health care-associated infections (11,12).   
 
The increased risk of postpartum infection following cesarean delivery has 
motivated research to establish practices now accepted as standards of care.  The 
routine use of prophylactic antibiotics in women undergoing cesarean delivery 
reduces the risk of fever, wound infection, endometritis, serious infectious 
morbidity, maternal urinary tract infections, and decreased maternal length of stay 
in the hospital (13).  Vaginal cleansing with an antiseptic solution immediately prior 
to cesarean delivery reduces the risk of endometritis but has not been found to 
reduce the number of fevers or wound complications (14). However, despite these 
measures, post-cesarean wound complications, with disruption and/or infection 
still occurs. 
 
Of the heavy metals, silver possesses antibacterial activity and thus, has been used 
in medicine for centuries.  Well-known uses of silver include silver nitrate drops to 

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prevent gonococcal opthalmia neonatorum and silver sulfadiazine to prevent burn 
wound infections (15).  While the antimicrobial mechanism of silver is not 
completely understood, proposed pathways include oxidative destruction catalyzed 
by silver, targeting of membrane proteins, affinity for sulfhydryl groups, and 
blocking or destroying host-cell receptors (16). 
 
Silver-containing wound dressings and topical agents are widely used for burn 
injuries and chronic wounds, such as ulcers.  Wound dressings and creams 
containing silver may help promote wound healing as well as prevent local 
infections.  The use of silver for wound management is limited and, as a result, the 
literature investigating its use and recommendations for its use in wound 
management remain inconclusive.  In a recent prospective, randomized controlled 
trial involving SSI following colorectal surgery, the total incidence of SSI was 
significantly lower in the silver nylon dressing group versus the control group (17).  
However, other studies have failed to show a statistically significant reduction in 
SSIs with the use of silver-impregnated dressings (18-20). 
 
Evidence to support the use of silver-containing dressings to limit and treat post-
cesarean SSIs is particularly limited.  Connery et al. (2012) conducted a 
retrospective review to evaluate the effectiveness of silver-containing dressings 
versus traditional wound dressings in reducing additional postoperative visits 
associated with SSIs in patients undergoing cesarean delivery.  Although they did 
not find a significant difference between the experimental and control groups, the 
study was limited due to small number of study subjects and a higher number of 
medical comorbidities in the study group (21).    
 
Despite measures to decrease the risk of postpartum infection following cesarean 
delivery, the rate of SSI remains prominent.  Wound infections are responsible for 
longer hospital stays, readmissions, and ultimately, increased costs to the healthcare 
system.  Silver-containing dressings may prevent wound infection.  The purpose of 
the current study is to determine if the use of a silver-impregnated dressing 
decreases the incidence of SSI following cesarean delivery.     
 
Purpose: To investigate the role of an adherent soft silicone anti-microbial 
occlusive foam silver-impregnated dressing for primary cesarean delivery.  
 
Primary Aims: 
1. To determine the primary cesarean wound complication rate using the 
adherent soft silicone silver impregnated anti-microbial occlusive foam 
dressing silver-impregnated dressing 
 
Secondary Aims: 
1. To assess pain scores by VAS in primary C-section patients using the adherent 
soft silicone silver impregnated anti-microbial occlusive foam dressing silver-
impregnated dressing 

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2. To assess cosmetic appearance of the incision based on Stony Brook scar 
evaluation scale scores for those patients using the adherent soft silicone silver 
impregnated anti-microbial occlusive foam dressing silver-impregnated 
dressing. 
  
Methods and Materials 
 
Study Population and Recruitment 
 
This single-center, prospective, observational trial will include women between 18 
and 45 years of age with viable pregnancies (24 weeks or greater) undergoing 
primary cesarean delivery at Loyola University Medical Center, Maywood, Illinois.    
 
Inclusion criteria: 
 
Participants must meet all of the following criteria: 
 Consent to undergo cesarean delivery 
 Between the ages of 18 and 45 
 Primary C-section 
 Subcuticular skin closure 
 Able to consent, fill out study documents, and complete all study procedures 
and follow-up visits 
 
Exclusion criteria: 
 Patients with an allergy to silver 
 Inability to obtain informed consent 
 Staples 
 Repeat C-section 
 Vertical skin incision 
 Intrapartum fever of 100F or > 
 
Enrollment 
 
Women will be approached for voluntary study participation upon admission to 
labor and delivery or the antepartum unit.  A member of the research team will 
explain the purpose and procedures of the study.  Potential participants who meet 
the inclusion criteria and sign the research consent document will be enrolled.  A 
signed copy of the research consent document will be given to the subject.  The 
investigator will keep the original research consent document, in keeping with 
prevailing research regulations.   
 
 
Protection of Human Subjects 
 
Recruitment and Informed Consent 

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Participants will be counseled by the study personnel (investigator or study 
coordinator) prior to signing informed consent for study participation.  All study 
procedures will be approved by the LUMC Institutional Review Board.   
 
Protection and Informed Consent 
 
This protocol will comply with all prevailing regulations that govern human subject 
research.  Our research team is directly responsible for monitoring the safety of 
study participants.  All adverse events will be documented and reported to our IRB 
in a timely manner.  Finally, the research team and our IRB will report serious 
adverse events that affect study conduct to the appropriate NIH program officers. 
 
In addition, strict research procedures will be followed to minimize risks to the 
privacy of participants.  Patient identifiers will not be included on any study 
documents, and identifying information will not appear in any electronic database.  
Once a patient consents to join the study, they will be assigned a study ID number, 
which will then be used to refer to that patient for the duration of the study.  
Documents linking patient identifiers and study ID will be kept in a locked cabinet, 
separate from other study documents.   
 
 
Study Flow and Measurements 
 
As part of clinical care, all patients who are admitted to Loyola’s labor and delivery 
or antepartum unit undergo a standardized history and physical examination.  At 
the time of recruitment for the study, all study participants will undergo a 
standardized baseline obstetric evaluation, which includes: 
 Demographics: age, self-reported race and ethnicity, medications, allergies, 
prior medical and surgical history, obstetric and gynecologic history  
 Examination: gestational age, maternal BMI, rupture of membranes, labor, 
temperature, blood pressure 
 
Methodology of Measurements: 
 
Women who are admitted to labor and delivery or the antepartum unit will be 
invited to participate.  Those who require a cesarean delivery will undergo standard 
perioperative management: surgical skin preparation with Chloroprep solution, 
vaginal betadine prep, and prophylactic antibiotics.  Women, who consented to 
participate, have a Pfannensteil incision and subcuticular skin closure will have the 
study dressing, Mepilex Border AG,  placed.  
Mepilex Border Ag is produced by Molynycke Health Care, and is a commercially 
available adherent soft silicone anti-microbial occlusive foam silver-impregnated 
dressing. This dressing was designed to aid in healing of wounds at high risk for 
infection, such as postoperative wounds, with provision of localized antimicrobial 

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activity. The high risk for wound infection and complications in our population led 
to selection of this dressing. No contraindications have been identified. 
 
The cesarean delivery technique may differ among health care providers at our 
institution but generally follows usual practice, including perioperative prophylactic 
antibiotics and surgical skin preparation with Chloroprep solution, vaginal betadine 
prep, saline irrigation of the subcutaneous layer, and the use of cautery to obtain 
hemostasis.  In addition, the subcutaneous layer is reapproximated with 3-0 Vicryl 
for all women with a subcutaneous layer greater than 2.0 cm.  The skin will be 
closed with continuous absorbable suture, e.g. 3-0 Vicryl or Monocryl.  Women with 
subcuticular suture will have adhesive strips applied with benzoin prior to the 
placement of the dressing.   
 
If not participating, the wound will be dressed with a standard dressing. The 
standard dressing will be removed by 24 hours postoperatively.  The study dressing 
will be removed during the first 7 days post-op only to allow/require dressing 
changes due to clinical signs of infection, leakage, or if the dressing falls off.   
Otherwise the study dressing will be removed on postoperative day 7 by a 
physician.  
 
Obstetric physicians will perform a standardized physical examination of the wound 
dressing on each postoperative day, at 7 days post-operatively on dressing removal, 
and the wound will be examined also at the standard 6 weeks postpartum 
examination for patients in both groups.  For patients who do not return for their 
postpartum visit at 7 days and 6 weeks, a standardized phone evaluation will be 
conducted by trained study personnel; any report of wound complication will be 
documented in the medical record.   
 
The primary outcome variable will be a composite of wound disruption and/or 
infection occurring within 4 weeks postoperative (wound complication rate: SSI).  
Wound disruption will be defined as any separation of the wound (ranging from 
small skin defects to entire separation of the wound) and subcutaneous skin 
dehiscence, i.e. from seroma or hematoma.  Wound infection will be classified by the 
Centers for Disease Control and Prevention (CDC) guidelines (22).  Secondary 
outcomes will include: pain measured at 24h, 48 h, 7 days at dressing removal, and 
6 weeks after cesarean delivery using a ten-point visual analog scale (VAS) from 0 to 
10 (with 0 indicating no pain and 10 indicating worst conceivable pain), cosmesis 
score (as defined by the Stony Brook Scar Evaluation Scale (23)) 7days and 6 weeks 
postoperatively, mobility assessment, readmission to the hospital, post discharge 
fever or antibiotic therapy, and additional clinic visits (both routine and 
unscheduled). Please see Figures 1 and 2. Additionally, all patients will be queried 
on degree of satisfaction on a scale of 1-10 as will clinicians queried on ease of use. 
 
In addition, deidentified demographic and outcome data on those who had a 
primary csection with transverse incision closed in a subcuticular fashion who did 
not participate in the silver dressing during the same time period were collected. 

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Analysis Plan 
 
Statistical Considerations: 
Data Management: Data forms collected will be converted to equivalent electronic 
data entry forms with use of REDCap. REDCap (Research Electronic Data Capture) is 
a secure, web-based application designed to support data capture for research 
studies, providing: 1) an intuitive interface for validated data entry; 2) audit trails 
for tracking data manipulation and export procedures; 3) automated export 
procedures for seamless data downloads to common statistical packages; and 4) 
procedures for importing data from external sources.  REDCap is hosted on secure 
servers located in the Loyola Medical School Campus and supported by the IT 
department.  Project staff will be trained in the use of REDCap for entry of study 
data.  Appropriate logic and limits checking (including cross-form validity checks) 
will be implemented in REDCap to facilitate accurate and consistent data entry. 
Study information within the virtual environment will be available for participant 
tracking activities such as production of result and reminder letters, scheduling of 
interim telephone contacts, and scheduling and tracking of follow-up visits.  
 
Statistical Analysis: It has been argued that the current rate of wound complication 
is about 10%. We postulate that patients following this treatment will experience a 
lower rate of wound complication. The incidence of infection will be estimated as 
the proportion of patients who developed infection by the end of the study period. 
Confounded-adjusted rates will be estimated using generalized linear models 
(identity link, binomial family). We will apply a one-sample, two-sided, 5% 
significance Z-test to compare the rate of infection with the new treatment to the 
historical 10%.  
 
In addition, comparisons between the silver dressing group and the contemporary 
comparison group will be made by T-test, Chi-square, Fishers exact test, logistic 
regression modeling.  
 
Sample Size/Power Justification: As stated above, we are interested in demonstrating 
that the rate of wound complication is lower than the historical 10% value found in 
the literature. We will accrue 185 patients to detect a 5% difference (10% vs 5%) 
using the one-sample Z-test with 80% statistical power. Testing via the generalized 
linear model to adjust for confounders will increase the statistical power to detect 
differences. 
 
 
 
References 
 
1. 
Joyce A. Martin BEH, Stephanie J. Ventura, Michelle J.K. Osterman, T.J. 
Mathews. Births: Final Data for 2011. Hyattsville, MD: National Center for Health 
Statistics, 2013  Contract No.: 1. 

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2. 
Gibbs RS. Clinical risk factors for puerperal infection. Obstetrics and 
Gynecology. 1980;55(5 Suppl): 178S-84S. 
3.  
Owen J, Andrews WW. Wound complications after cesarean sections. Clin 
Obstet Gynecol 1994;37:852-5. 
4. 
National Nosocomial Infections Surveillance S. National Nosocomial 
Infections Surveillance (NNIS) System Report, data summary from January 1992 
through June 2004, issued October 2004. American journal of infection control. 
2004;32(8):470-85. 
5. 
Opoien HK, Valbo A, Grinde-Andersen A, Walberg M. Post-cesarean surgical 
site infections according to CDC standards: rates and risk factors. A prospective 
cohort study. Acta obstetricia et gynecologica Scandinavica. 2007;86(9):1097-102. 
6. 
Vermillion ST, Lamoutte C, Soper DE, Verdeja A. Wound infection after 
cesarean: effect of subcutaneous tissue thickness. Obstetrics and gynecology. 
2000;95(6 Pt 1):923-6. 
7. 
Culver DH, Horan TC, Gaynes RP, Martone WJ, Jarvis WR, Emori TG, et al. 
Surgical wound infection rates by wound class, operative procedure, and patient 
risk index. National Nosocomial Infections Surveillance System. The American 
journal of medicine. 1991;91(3B):152S-7S. 
8. 
Yokoe DS, Christiansen CL, Johnson R, Sands KE, Livingston J, Shtatland ES, et 
al. Epidemiology of and surveillance for postpartum infections. Emerging infectious 
diseases. 2001;7(5):837-41. 
9. 
Declercq E, Barger M, Cabral HJ, Evans SR, Kotelchuck M, Simon C, et al. 
Maternal outcomes associated with planned primary cesarean births compared with 
planned vaginal births. Obstetrics and gynecology. 2007;109(3):669-77. 
10. 
Cardoso Del Monte MC, Pinto Neto AM. Postdischarge surveillance following 
cesarean section: the incidence of surgical site infection and associated factors. 
American journal of infection control. 2010;38(6):467-72. 
11. 
Zimlichman E, Henderson D, Tamir O, Franz C, Song P, Yamin CK, et al. Health 
Care-Associated Infections: A Meta-analysis of Costs and Financial Impact on the US 
Health Care System. JAMA internal medicine. 2013;173(22):2039-46. 
12. 
Olsen MA, Butler AM, Willers DM, Gross GA, Hamilton BH, Fraser VJ. 
Attributable costs of surgical site infection and endometritis after low transverse 
cesarean delivery. Infection control and hospital epidemiology : the official journal 
of the Society of Hospital Epidemiologists of America. 2010;31(3):276-82. 
13. 
Smaill FM, Gyte GM. Antibiotic prophylaxis versus no prophylaxis for 
preventing infection after cesarean section. The Cochrane database of systematic 
reviews. 2010(1):CD007482. 
14. 
Haas DM, Morgan S, Contreras K. Vaginal preparation with antiseptic solution 
before cesarean section for preventing postoperative infections. The Cochrane 
database of systematic reviews. 2013;1:CD007892. 
15. 
Levinson W. Review of medical microbiology and immunology. 12th ed. New 
York: McGraw-Hill Medical; 2012. p. p. 
16. 
Silvestry-Rodriguez N, Sicairos-Ruelas EE, Gerba CP, Bright KR. Silver as a 
disinfectant. Reviews of environmental contamination and toxicology. 2007;191:23-
45. 

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17. 
Krieger BR, Davis DM, Sanchez JE, Mateka JJ, Nfonsam VN, Frattini JC, et al. 
The use of silver nylon in preventing surgical site infections following colon and 
rectal surgery. Diseases of the colon and rectum. 2011;54(8):1014-9. 
18. 
Biffi R, Fattori L, Bertani E, Radice D, Rotmensz N, Misitano P, et al. Surgical 
site infections following colorectal cancer surgery: a randomized prospective trial 
comparing common and advanced antimicrobial dressing containing ionic silver. 
World journal of surgical oncology. 2012;10:94. 
19. 
Epstein NE. Do silver-impregnated dressings limit infections after lumbar 
laminectomy with instrumented fusion? Surgical neurology. 2007;68(5):483-5; 
discussion 5. 
20. 
Siah CJ, Yatim J. Efficacy of a total occlusive ionic silver-containing dressing 
combination in decreasing risk of surgical site infection: an RCT. Journal of wound 
care. 2011;20(12):561-8. 
21. 
Connery SA, Downes KL, Young C. A retrospective study evaluating silver-
impregnated dressings on cesarean wound healing. Advances in skin & wound care. 
2012;25(9):414-9. 
22. 
Mangram AJ, Horan TC, Pearson ML, Silver LC, Jarvis WR. Guideline for 
prevention of surgical site infection, 1999. Hospital Infection Control Practices 
Advisory Committee. Infection control and hospital epidemiology : the official 
journal of the Society of Hospital Epidemiologists of America. 1999;20(4):250-78; 
quiz 79-80. 
23. 
Singer AJ, Arora B, Dagum A, Valentine S, Hollander JE. Development and 
validation of a novel scar evaluation scale. Plastic and reconstructive surgery. 
2007;120(7):1892-7. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Figure 1. Visual Analog Scale (VAS) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Category 
Response 
Score 
Width 
>2mm 
</=2mm 
0 
1 
Height 
Elevated/Depressed 0 

10 
 
Flat 
1 
Color (compared 
to surrounding 
skin) 
Darker (red, purple, 
brown, black) 
Same or lighter 
0 
 
1 
Hatch/Suture 
Marks 
Present 
Absent 
0 
1 
Overall 
Appearance 
Poor 
Good 
0 
1 
Total Score 
---------------- 
 
 
Figure 2. Stony Brook Scar Evaluation Scale