Negative Pressure Wound Therapy in Obese Gynecologic Oncology Patients: A Randomized Controlled Trial
Phase: NA
Conditions: Postoperative Complications, Obesity, Gynecologic Neoplasms
Sponsor: Masonic Cancer Center, University of Minnesota

Department of Obstetrics, Gynecology and Women’s Health and 
Department of Surgery 
University of Minnesota 
 
 
 
Negative Pressure Wound Therapy in Obese Patients Undergoing 
Laparotomy for Gynecologic or Other Abdominal Cancer: A Randomized 
Controlled Trial 
 
CPRC # 2013NTLS073 
 
 
Principal Investigator: 
Deanna G.K. Teoh, MD 
 
Co-Investigators: 
Department of Obstetrics, Gynecology and Women’s Health 
Linda Carson, MD 
Levi S. Downs, Jr., MS, MD  
Peter A. Argenta, MD 
Rahel Ghebre, MD 
Melissa Geller, MD 
Sally A. Mullany, MD 
Colleen Rivard, MD 
 
Department of Surgery, Division of Colon and Rectal Surgery 
Mary R. Kwaan, MD, MPH 
 
Study Statistician: 
Rachel Isaksson Vogel, MS 
Biostatistics and Bioinformatics Core 
Masonic Cancer Center 
University Of Minnesota 
 
 
Participating Sites: 
University of Minnesota Medical Center, Fairview 
 
 
Version Date: 
December 9, 2013 
 
Confidential 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
Revision History 
 
Version 
Date 
Summary of Changes 
Consent 
Change? 
Y/N 
Consent 
Version 
Date 
07/30/2013 original to Kinetic Concepts Inc. (KCI) 
 
07/30/2013 
12/09/2013 original version to CPRC and IRB 
incorporates changes from KCI’s review  
 
12/09/2013 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
PI Contact Information: 
Deanna G. Teoh, MD 
Mayo Mail Code 395 
420 Delaware St SE 
Minneapolis, MN 55455 
Phone:  612-265-6503 
Fax:  612-626-0665 
Email:  dkteoh@umn.edu 
 
 
 
 
 
December 9, 2013 
Page 2 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
TABLE OF CONTENTS 
 
Synopsis ......................................................................................................................................................................... 4 
1.0 
Introduction and Overview .............................................................................................................................. 5 
2.0 
Study Objectives ............................................................................................................................................. 5 
3.0 
Background and Significance .......................................................................................................................... 6 
4.0 
Wound Complications at the University Of Minnesota .................................................................................. 6 
5.0 
Research Design .............................................................................................................................................. 6 
6.0 
Patient Selection .............................................................................................................................................. 7 
7.0 
Patient Registration and Randomization ......................................................................................................... 7 
8.0 
Study Procedures ............................................................................................................................................. 8 
8.1 
Study Plan .................................................................................................................................................... 8 
8.2 
Assigned Care  ............................................................................................................................................. 8 
8.3 
Risks of Study Participation ......................................................................................................................... 9 
8.4 
Supportive Care .......................................................................................................................................... 10 
8.5 
Duration of Study Participation .................................................................................................................. 10 
9.0 
Prevena™ Incision Management System14 ................................................................................................... 10 
9.1 
Indication for Use ....................................................................................................................................... 10 
9.2 
Optimum Use Conditions ........................................................................................................................... 11 
9.3 
Contraindications ....................................................................................................................................... 11 
9.4 
Warnings  ................................................................................................................................................... 11 
10.0 
Statistical Considerations .............................................................................................................................. 12 
10.1 
Data Analysis ............................................................................................................................................. 12 
10.2 
Sample Size Calculations ........................................................................................................................... 12 
11.0 
Administrative Considerations ...................................................................................................................... 13 
11.1 
Conduct of the Trial ................................................................................................................................... 13 
11.2 
Data Management ...................................................................................................................................... 13 
11.3 
Data and Safety Monitoring Plan ............................................................................................................... 13 
11.4 
Event Reporting to the IRB and Cancer Center’s Data and Safety Monitoring Council (DSMC) ............. 13 
12.0 
References ..................................................................................................................................................... 14 
Appendix I – Patient Eligibility Checklist ................................................................................................................... 16 
 
 
 
 
 
 
December 9, 2013 
Page 3 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
 
Synopsis 
Overview: 
Most gynecologic and many intra-abdominal malignancies are treated with an initial surgical procedure.  
Over the past 20 years there has been a dramatic increase in obesity rates in the US with more than one 
third (35.7%) of US adults being obese (BMI  > 30kg/m2) or morbidly obese (BMI>35 kg/m2).  There is a 
direct link between obesity and wound complications following surgery with an increasing BMI leading 
to increasing rates of complications.  Negative pressure wound therapy (NPWT) is a system that utilizes 
sub-atmospheric pressure to improve wound healing by increasing the formation of granulation tissue.  
NPWT has been shown to improve outcomes in both the orthopedic and cardiothoracic surgery 
populations.  To date, there is no prospective study evaluating the application of prophylactic NPWT in 
laparotomy patients.   
 
 
Primary Objective:  
To evaluate the rate of wound complications with negative pressure wound therapy (NPWT) as compared 
to standard surgical closure and post-operative wound care in obese patients (BMI ≥35 kg/m2) undergoing 
laparotomy for a suspected gynecologic malignancy or other abdominal cancer.    
 
Secondary Objective: 
To compare the time between surgery and the start of anti-cancer therapy (chemotherapy and/or radiation 
therapy) between those patients diagnosed with a malignancy who received NPWT and those who 
received standard surgical closure 
 
Patient Population: 
Morbidly obese (BMI ≥ 35 kg/m2) adult patients presenting for surgical treatment of a known or 
suspected gynecologic malignancy or other abdominal cancer by laparotomy incision 
  
Study Procedures: 
After screening and obtaining written consent, but prior to surgery 1:1 randomize to either: 
• 
Negative pressure wound therapy (NPWT) 
• 
Standard surgical closure 
Assess wound complications at 1st post-operative visit (10-14 days after initial procedure) 
 
If no cancer diagnosis, final study assessment at 1st post-operative visit 
 
If cancer diagnosis is made, chart review at 3 months post-surgery to determine time between surgery and 
start of anti-cancer therapy (chemotherapy and/or radiation therapy) 
 
Enrollment Goal:   
200 patients randomized over 24 months 
 
 
 
 
 
 
December 9, 2013 
Page 4 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
1.0 
Introduction and Overview 
Up to 90% of type I (estrogen-dependent) endometrial cancer patients are obese1 and 
obesity is considered a risk factor for both endometrial and ovarian cancers2.   Most 
gynecologic malignancies are treated with an initial surgical procedure.  A number of 
colorectal diseases are also increased with obesity including diverticular disease and 
colorectal cancer15,16, 17.  A central challenge for surgeons is the increase in the rates of 
wound complications following surgery given the rise in obesity.  The rate of wound 
complications for gynecologic oncology procedures is 34% overall and is highly 
correlated with BMI4.  Patients with a BMI of ≥40 kg/m2 had a 10 fold increase in the 
risk of wound complications compared to normal weighted patients6.  Some patients are 
able to circumvent this problem with a minimally invasive approach to their surgery; 
however, obesity increases the risk of conversion to an open procedure.  Wound 
complications are not only distressing to patients but can also delay necessary adjuvant 
therapy such as chemotherapy and radiation.   
 
 
Negative pressure wound therapy (NPWT) is a system that utilizes sub-atmospheric 
pressure to improve wound healing by increasing the formation of granulation tissue.  
The mechanism for this improved wound healing is thought to be increased local blood 
flow, mechanical stress at the wound surface, removal of factors that inhibit wound 
healing and decreased bacterial burden.  To date there are good data to show the benefit 
of using NPWT to treat wound complications that arise post-operatively.  In the 
orthopedic and cardiothoracic surgery literature there is evidence to suggest that 
prophylactic NPWT placed over a closed incision decreases wound dehiscence and 
infection rate, with a 40% decrease in orthopedic patients and 4-fold decrease in morbidly 
obese cardiothoracic patients.  However, to date, there is no prospective study evaluating 
the application of prophylactic NPWT in laparotomy patients. 
 
 
2.0 
Study Objectives 
The primary goal of this study is to evaluate if the use of prophylactic negative pressure 
wound therapy (NPWT) over a closed incision improves postoperative outcomes and 
cancer care for morbidly obese (BMI ≥35 kg/m2) patients undergoing laparotomy for 
treatment of a suspected gynecologic or other abdominal malignancy is comparable or 
better to wound healing after standard surgical closure and wound care.   
 
This comparison will be achieved by: 
• Assessing the incidence of wound complications, specifically, dehiscence and 
infection at the 1st post-operative visit (10-14 days after surgery) 
• documenting the time from surgery to the start of anti-cancer treatment in a 
subset of patients receiving a cancer diagnosis by chart review approximately 
3 months after surgery 
 
 
 
 
 
 
December 9, 2013 
Page 5 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
3.0 
Background and Significance 
The obesity epidemic is a growing problem in the US and its effects are felt very heavily 
on the gynecologic oncology population.  Both endometrial and ovarian cancers are 
increased in the obese populations1,2, and the majority of gynecologic malignancies are 
initially treated with a surgical procedure.  A number of colorectal diseases are also 
increased with obesity including diverticular disease and colorectal cancer15,16, 17.  Risks 
and complications of surgery are much greater in the obese population.  The reported rate 
of wound complications in the gynecologic oncology population is 34-40% depending on 
the location4.  Wound complications are highly correlated with patient BMI.  These 
wound complications can lead to a delay in necessary adjuvant therapies such as 
chemotherapy and radiation.  It is known that delays in the initiation of adjuvant therapy 
can have a negative impact on survival.   
 
NPWT is a system that uses sub-atmospheric pressure to alter the physiologic and 
chemical environment of the wound bed.  It is postulated that this works through several 
different mechanisms including increased local blood flow, increased mechanical stress 
leading to increases in cellular proliferation, more effective removal of factors that inhibit 
wound healing including bacteria and fluid7,8.  Studies using NPWT in an open 
laparotomy incision to facilitate healing by secondary intention show that it leads to 
decreased wound healing time10.  However, to date, there are few studies evaluating the 
use of prophylactic NPWT over a closed incision, and most of the existing data is in the 
orthopedic and cardiothoracic surgery literature.  The use of prophylactic NPWT over 
orthopedic wounds has been shown to decrease wound dehiscence and infection rates by 
40%, and has decreased the rate of wound complications 4-fold in obese patients 
undergoing cardiothoracic surgery12,13.  However, it is unclear if this same benefit will be 
seen with abdominal laparotomy incisions. 
 
 
4.0 
Wound Complications at the University Of Minnesota 
We performed a retrospective chart review of all patients with a BMI ≥ 30 kg/m2 who 
have undergone a laparotomy for a known or suspected gynecologic malignancy at our 
institution in the past 6 months.  We found that of 51 obese patients to undergo a 
laparotomy, 13 (25%) had some form of wound complication, either a wound dehiscence 
or infection.  This is on par with what is reported in the literature.  Further, 5 of the 51 
patients were readmitted to the University of Minnesota hospital due to their wound 
complications, for a readmission rate of almost 10%.  The results of this chart review 
were used to inform our sample size calculations. 
 
 
5.0 
Research Design 
This is a randomized controlled trial in which eligible patients will be randomized to 
either a control or intervention group.  All patients undergoing laparotomy for a known or 
suspected gynecologic or other abdominal cancer will be approached for eligibility.  
Once all eligibility criteria are met, the patient will be consented both with verbal and 
 
 
 
 
December 9, 2013 
Page 6 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
written consent procedures.  Following consent the patient will be randomized to either:  
1) routine closure of the surgical site (control arm); or 2) closure of the wound with a 
prophylactic NPWT placed over the closed surgical incision.  The standard surgical 
closure consists of closure of the fascia with a looped PDS suture in a running fashion 
either with the use of a mass closure technique or a Smead Jones closure at the discretion 
of the operating surgeon, closure of the subcutaneous space if >2 cm deep, followed by 
staple or suture closure of the skin.  These same steps will be followed for the NPWT 
group with the addition of placement of the NPWT system over this closed incision.  This 
NPWT system will be removed on post-operative day number 2 or 3, prior to patient 
discharge from the hospital.  The staples, if used, will then be removed in the usual time 
frame of anywhere from 10 to 21 days post-operatively.  This will also allow for 
standardized evaluation of the patient’s wound to determine if there have been any 
wound complications since their surgery.  Patients will be followed for the development 
of any wound complications including infection, dehiscence and evisceration for 4 weeks 
after surgery.  For patients who develop a wound complication, we will track required 
therapies, including readmission to the hospital, reoperation, antibiotic therapy, wound 
opening with healing by secondary intention, including method of wound care and 
duration of wound healing.  For patients requiring adjuvant therapy (chemotherapy and/or 
radiation), we will record duration from time of surgery to initiation of adjuvant therapy. 
 
6.0 
Patient Selection 
Study entry is open to adult patients regardless of gender, race or ethnic background.  
While there will be every effort to seek out and include minority patients, the patient 
population is expected to mirror the obese patient population at the University Of 
Minnesota.   
 
Inclusion Criteria 
6.1 
Known or suspected gynecologic or other abdominal malignancy (such as 
colorectal, liver, pancreatic, kidney and stomach) for which laparotomy is planned 
6.2 
Obese – defined as a Body Mass Index (BMI) ≥ 35 kg/m2 as calculated in the Epic 
computer record 
6.3 
18 years of age or older 
6.4 
Able and willing to provide written consent  
Exclusion Criteria 
6.5 
Known true tape allergy 
6.6 
Sensitivity to silver 
6.7 
History of intolerance to Negative Pressure Wound Therapy 
 
7.0 
Patient Registration and Randomization 
Patients will be registered into OnCore after written consent is provided and eligibility is 
confirmed (appendix I), but prior to the performance of any research related procedures.  
 
 
 
 
December 9, 2013 
Page 7 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
Randomization will occur at the time of registration.  To prevent bias and minimize the 
possibility of confounding, consenting patients will be randomly assigned 1:1 to either 
NPWT or standard of care.   
 
8.0 
Study Procedures 
8.1 
Study Plan 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
8.2 
Assigned Care (Standard Closure and Wound Care vs. Standard Closure 
with Negative Pressure Wound Therapy) 
 
8.2.1 Standard Closure and Wound Care 
The standard surgical closure consists of closure of the fascia with a looped PDS 
suture in a running fashion either in with the use of a mass closure technique or a 
Smead Jones closure at the discretion of the operating surgeon, closure of the 
subcutaneous space if >2 cm deep, followed by staple or suture closure of the 
skin. 
Assess for eligibility and consent in clinic 
Randomize (1:1) to NPWT or standard of care  
NPWT 
Standard Wound Closure 
Remove NPWT on POD #2-3 
Staples Removed on POD #10-14, 
assess Wound Complications 
Staples Removed on POD #10-14, 
assess Wound Complications 
Follow patients with malignancies 
for timing of adjuvant therapy 
Follow patients with malignancies 
for timing of adjuvant therapy 
 
 
 
 
December 9, 2013 
Page 8 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
 
Post-operative wound care will be standard of care per institutional guidelines. 
 
8.2.2 Standard Closure and Negative Pressure Wound Therapy 
The same standard surgical closure as used by the standard of care group will be 
used for patients randomized to prophylactic placement of the Prevena™ Incision 
Management System.  As in the previous section it consists of closure of the 
fascia with a looped PDS suture in a running fashion either in with the use of a 
mass closure technique or a Smead Jones closure at the discretion of the operating 
surgeon, closure of the subcutaneous space if >2 cm deep, followed by staple or 
suture closure of the skin.   
 
The Prevena™ Incision Management System will be placed over the closed 
incision.  It will be removed on post-operative day 2 or 3 as clinically indicated 
and prior to the patient’s discharge from the hospital.   
8.3 
Risks of Study Participation 
8.3.1 Standard of Care 
Risks to the patients randomized to standard of care will be no different than 
undergoing the same surgical procedure without participating in this study. 
 
8.3.2 Negative Pressure Wound Therapy (NWPT) 
NPWT has very few complications associated with its use.  There are few reports 
of fistula development with the use of NPWT but these are in patients where the 
NPWT has been placed directly over intestines and not on a closed incision.  
Additionally, NPWT is widely used in treatment of an open wound, and placed 
directly over the fascia with few reported complications. When large amounts of 
fluid are removed from an incision large fluid losses can lead to hemodynamic 
changes in patients; however, it is anticipated that this fluid loss would be much 
greater in an open wound (NPWT is placed directly over the fascia and within the 
subcutaneous tissue) than over a closed wound.  Fluid status will be followed 
closely and managed per the standard postoperative protocol.   
 
There are also some less serious complications such as local cutaneous reactions 
(rash, redness, pruritis, urticarial), allergic reaction, maceration, minor soft tissue 
damage, skin stripping, minor bleeding, pain, bruising. All patients will be 
monitored closely for signs of skin irritation and will be treated appropriately with 
barrier creams as needed. In cases where NPWT is used to aid in healing by 
secondary intention, the NPWT is in place for weeks to months with minimal skin 
irritation; it is anticipated that this risk of irritation will be even lower when the 
NPWT device is in place for only 2-3 days. 
 
There are some other uncommon risks associated with the NPWT including,  
 
 
 
 
December 9, 2013 
Page 9 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
bleeding complications (associated with the surgical procedure, concomitant 
therapies and co- -morbidities), first degree burn (if device gets warm), exposure 
related infection,  localized infection, physical discomfort, minor desiccation (due 
to dressing leak), moderate soft tissue damage (i.e. due to trip hazard, tubing 
entanglement) and deterioration of the wound (due to lack of visibility of incision 
site through dressing. 
 
8.3.3 All Patients, Regardless of Post-Operative Care 
There is a small risk of loss of confidentiality; however steps will be taken to 
minimize this by assigning the patient a unique patient identifier at the time of 
study enrollment to be used in place of direct identifiers.  A master list will be 
kept in OnCore, the Cancer Center’s password protected clinical database that 
resides on the University of Minnesota server. 
 
8.4 
Supportive Care 
Optimal patient care will be given to all patients regardless of their post-operative 
wound care assignment per institutional guidelines, including those for infection 
control.   
8.5 
Duration of Study Participation 
It is expected the duration of study participation will be less than 2 months. 
 
All patients will be assessed for wound complications (including infection, 
dehiscence and evisceration) at their 1st post-operative visit approximately 10-14 
days after surgery.   
 
Patients will continue to be tracked for wound complications for a minimum of 4 
weeks after surgery by review of clinic notes/medical records.  For patients who 
develop a wound complication, the type of complication, treatment received and 
outcomes will be captured. 
 
For patients with a cancer diagnosis that requires anti-cancer therapy 
(chemotherapy and/or radiation), the therapy start date of therapy will be 
recorded. 
 
9.0 
Prevena™ Incision Management System14 
The Prevena Incision Management System will be provided by Kinetic Concepts Inc. 
(KCI) for the purposes of this study.   
9.1 
Indication for Use 
The Prevena Incision Management System is intended to manage the environment 
of surgical incisions that continue to drain following suturing or stapling by 
maintaining a closed environment and removing exudate by negative pressure 
 
 
 
 
December 9, 2013 
Page 10 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
wound therapy.  This study intends to use the device according to its approved 
indications. 
9.2 
Optimum Use Conditions 
For maximum benefit is should be applied immediately post-surgery and used 
continuously for a minimum of two days and up to a maximum of seven days.  
For the purposes of this study the device will be used for two to three days with 
removal prior to discharge from the hospital. 
9.3 
Contraindications 
Sensitivity to silver – potential participants of this study with a history of this 
sensitivity will be excluded per section 6.6.  
9.4 
Warnings 
– 
refer 
to 
the 
Clinician 
Guide 
for 
full 
details 
http://www.kci1.com/cs/Satellite?c=Page&childpagename=KCI1%2FKCILayout
&cid=1229636259704&pagename=KCI1Wrapper 
• Bleeding – before applying, ensure that hemostasis has been achieved and 
tissue planes have been approximated.  If active bleeding develops or 
frank blood is seen in the tubing or canister leave the Dressing place, but 
turn off the device and provide immediate medical assistance. 
• Infected wounds – monitor the wound, peri-wound area, exudate, and 
patient’s general clinical status for signs of infection; if infection develops 
Prevna Therapy should be discontinued 
• Allergic response – the Prevena Incision Dressing has an acrylic adhesive 
coating and a skin interface layer lined with silver which may present a 
risk of an adverse reaction in patients with known hypersensitivity.  
Patients with a known silver or tape sensitivity are not eligible for this 
study.   
• Defibrillation – remove the Prevena Incision Dressing if defibrillation is 
required in the area of the dressing placement 
• Magnetic Resonance Imaging (MRI) – the Prevena Therapy Unit is unsafe 
in the MRI environment and interruption of therapy during an MRI may 
reduce its effectiveness.  The Dressing can typically stay in place during 
the MRI. 
• Other diagnostic imaging - the Prevena Incision Dressing contains 
metallic silver which may impair visualization with certain imaging 
modalities. 
• Hyperbaric Oxygen Therapy – do not take the Prevena Therapy Unit or 
the Prevena Incision Dressing into the chamber 
• Canister full – if any time the canister becomes full of fluid as indicated by 
the Maximum Capacity Alert or visual inspection, turn off the therapy unit 
and attend to the canister. 
 
 
 
 
December 9, 2013 
Page 11 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
Refer to the Prevena Incision Management System website with links to the 
Clinician 
Guide 
for 
complete 
device 
details.   
http://www.kci1.com/KCI1/prevena# 
  
10.0 Statistical Considerations 
10.1 
Data Analysis 
The patient population demographics will be descriptively summarized both 
combined and by treatment randomization.  All analyses will be conducted under 
the intention-to-treat principle and all deviations and adverse events will be 
reported.  
 
Our primary aim is to compare rate of wound complications (wound dehiscence 
or infection) identified within first month after surgery by treatment group 
(standard of care or NPWT).  As this is a large randomized trial, the comparison 
will first be made using a Chi-squared test as we anticipate approximate balance 
in all measured and unmeasured confounders.  These results will be supplemented 
using logistic regression, including demographics and clinical variables (including 
surgeon) as appropriate.   
 
Our secondary aim is compare the time from surgery to starting adjuvant therapy 
among those with confirmed malignancies.  This will be measured in days and 
will be available regardless if patients undergo treatment at our study facilities as 
their surgeon will manage their care and maintain contact up to 6 months 
regardless of follow-up location. The effect of NPWT on the length of the number 
of days until treatment will be assessed using Poisson regression, adjusting for 
over-dispersion if necessary.  As stated above, we will supplement these results 
adjusting for demographic and clinical variables as appropriate.    
   
For all analyses, p-values of less than 0.05 will be considered statistically 
significant and will be performed using SAS software version 9.3 (Cary, NC).   
 
10.2 
Sample Size Calculations 
As stated in the Section 4, we retrospective chart review of this patient population 
found 25% rate of wound complications. Group sizes of 97 each (194 total) 
achieves 80% power to detect a difference between the group proportions of -
0.15; in other words, assuming the standard of care group has a complication rate 
of 25%, we could detect a complication rate in the NPWT group of 10% as being 
statistically significantly lower using a two-sized Z-test with a significance level 
of 0.05.  This represents a clinically significant change in complication rates while 
remaining a feasible number to recruit within the study sites.  Our proposed 
sample size is therefore 200 (100 in each group). 
 
The secondary aim is not to formally test hypotheses but rather to describe this 
outcome and calculate preliminary estimates of differences.  Among women 
undergoing this procedure at our study sites, approximately 70% will be 
 
 
 
 
December 9, 2013 
Page 12 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
diagnosed with a malignancy, resulting in a sample size of 140 for this analysis.  
Among women in the standard of care group, we anticipate they will begin 
adjuvant therapy within 4-6 weeks after surgery.  This sample size is more than 
sufficient (>90% power) to detect a difference of 1 day in time between surgery 
and beginning adjuvant therapy. 
 
11.0 Administrative Considerations 
11.1 
Conduct of the Trial 
The study will be conducted in accordance with the appropriate local regulatory 
requirement(s).   
The University Of Minnesota IRB will review all appropriate study 
documentation in order to safeguard the rights, safety and well-being of the 
patients.  The study will only be conducted at sites where IRB or Campus 
Administrator approval has been obtained.  The protocol, consent document, 
written information given to the patients, annual progress reports, and any 
revisions to these documents will be provided to the IRB by the investigator.   
Essential clinical documents will be maintained to demonstrate the validity of the 
study and the integrity of the data collected.  Master files should be established at 
the beginning of the study, maintained for the duration of the study and retained 
for a minimum of 6 years after the file has been terminated with the IRB.   
11.2 
Data Management  
Electronic data will be entered by a co-investigator and will be stored on a secure 
server.  Study data will be de-identified before data analysis.  Only the researchers 
directly involved with the study will have access to the data.  
11.3 
Data and Safety Monitoring Plan 
This is a minimal risk, non-therapeutic study.    
 
The Principal Investigator and key research staff will be responsible for preparing 
reports annually in concordance with this study’s Data Monitoring Plan to be 
reviewed by the University of Minnesota Cancer Center Protocol Review 
Committee and Institutional Review Board. These reports will focus on 
recruitment, retention, losses to follow-up, and adherence to protocol. Although 
the safety concerns for this project are expected to be minimal, reports will 
include a section on reports of adverse events that may be related to the study 
procedures.  
 
11.4 
Event Reporting to the IRB and Cancer Center’s Data and Safety 
Monitoring Council (DSMC) 
Safety concerns for this project are expected to be minimal with skin irritation as 
the primary expected concern.   Any events meeting an unexpected, serious 
 
 
 
 
December 9, 2013 
Page 13 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
adverse event defined as reportable (such as hospitalization) on the IRB’s website 
at http://www.research.umn.edu/irb/ae/.   The DSMC will be copied on all reports 
to the IRB. 
 
In addition, to be in compliance with local and federal regulations the following 
events/problems will be reported to the IRB and DSMC within the 10 working 
day time frame: 
 Any serious event (including on-site and off-site adverse events, injuries, side 
effects, deaths or other problems) which in the opinion of the local researcher 
was unanticipated, involved risk to subjects or others, and was possibly 
related to the research procedures 
 Any serious accidental or unintentional change to the IRB-approved protocol 
that involves risk or has the potential to recur;  
 Any deviation from the protocol taken without prior IRB review to eliminate 
apparent immediate hazard to a research subject; 
 Any publication in the literature, safety monitoring report (including Data and 
Safety Monitoring Reports), interim result or other finding that indicates an 
unexpected change to the risk/benefit ratio of the research; 
 Any breach in confidentiality that may involve risk to the subject or others; 
 Any complaint of a subject that indicates an unanticipated risk or that cannot 
be resolved by the research staff.  
 
 
12.0 References 
1. Nickles Fader A, Nieves Arriba L, Frasure HE, von Gruenigen VE.  Endometrial cancer and 
obesity: Epidemiology, biomarkers, prevention and survivorship.  Gyn Onc.  114:  121-27, 
2009. 
 
2. Olsen CM, Green AC, Whiteman DC, Sadeghi S, Kolahdooz F, Webb PM..  Obesity and the 
risk of epithelial ovarian cancer: A systematic review and meta-analysis.  Eur J of Cancer.  
43:  690-709, 2007.   
 
3. Schouten LJ, Goldbohm RA, van den Brandt PA.  Anthropometry, physical activity, and 
endometrial cancer risk:  results from the Netherlands Cohort Study.  J Natl Cancer Inst.  96:  
1635-38, 2004. 
 
4. Nugent EK, Hoff JT, Gao F, Massad LS, Case A, Zighelboim I, Mutch DG, Thaker PH.  
Wound complications after gynecologic cancer surgery.  Gyn Onc.  121:  347-52, 2011. 
 
5. Iglesias DA, Westin SN, Rallapalli V, Huang M, Fellman B, Urbauer D, Frumovitz M, 
Ramirez PT, Soliman PT.  The effect of body mass index on surgical outcomes and survival 
following pelvic exenteration.  Gyn Onc.  125:  336-42, 2012.   
 
 
 
 
 
December 9, 2013 
Page 14 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
6. Giugale LE, Di Santo N, Smolken ME, Havrilesky LJ, Modesitt SC.  Beyond mere obesity:  
Effect 
of 
increasing 
obesity 
classes 
on 
hysterectomy 
outcomes 
for 
uterine 
cancer/hyperplasia.  Gyn Onc.  127: 326-32, 2012.   
 
7. Venturi ML, Attinger CE, Mesbahi AN, Hess CL, Graw K.  Mechanisms and Clinical 
Applications of theVacuum-Assisted Closure (VAC) Device: A Review.  Am J Clin 
Dermatol.  6(3): 185-194, 2005. 
 
8. Morykwas MJ, Argenta LC, Shelton-Brown EL, McGuirt W.  Vacuum-assisted closure: A 
new method for wound control and treatment:  Animal studies and basic function.  Annals of 
Plastic Surgery.  38(6):  553-62, 1997. 
 
9. Dhir K, Reino AJ, Lipana J.  Vacuum-Assisted Closure Therapy in the Management of Head 
and Neck Wounds.  Laryngoscope.  119: 54-61, 2009. 
 
10. Schimp VL, Worley C, Brunello S, Levenback CC, Wolf JK, Sun CC, Bodurka DC, 
Ramireza PT.  Vacuum-assisted closure in the treatment of gynecologic oncology wound 
failures.  Gyn Onc.   92:  586-91, 2004. 
 
11. Antony S, Terrazas S.  A Retrospective Study: Clinical Experience Using Vacuum-Assisted 
Closure in the Treatment of Wounds.  J of the Nat Am Med Assoc.  96(8):  1073-1077, 
2004. 
 
12. Stannard JP, Volgas DA, McGwin G, Stewart RL, Obremskey W, Moore T, Anglen JO.  
Incisional Negative Pressure Wound Therapy after High-Risk Lower Extremity Fractures.  J 
Orthop Trauma.  26 (1):  37-41, 2012. 
 
13. Grauhan O,  Navasardyan A, Hofmann M, M€uller P, Stein J, Hetzer R.  Prevention of 
poststernotomy wound infections in obese patients by negative pressure wound therapy.  J 
Thorac Cardiovasc Surg.  143:  1-6, 2012. 
 
14. Prevena™ 
Incision 
Management 
System 
– 
Clinician 
Guide 
http://www.kci1.com/cs/Satellite?c=Page&childpagename=KCI1%2FKCILayout&cid=1229
636259704&pagename=KCI1Wrapper accessed August 9, 2013. 
 
15.  Rosemar A, Anger˚as U, Rosengren A. Body mass index and diverticular disease: a 28-year 
follow-up study in men. DisvColon Rectum 2008; 51: 450–455. 
 
16.  Renehan AG, Tyson M, Egger M, Heller RF, Zwahlen M.  Body-mass index and incidence 
of cancer: a systematic review and meta-analysis of prospective observational studies. 
Lancet 2008; 371: 569–578. 
 
17.  Russo A, Franceschi S, La Vecchia C, Dal Maso L, Montella M, Conti E et al. Body size 
and colorectal-cancer risk. Int J Cancer 1998; 78: 161–165. 
 
 
 
 
 
 
December 9, 2013 
Page 15 of 16 
CPRC #2013NTLS073 

Negative Pressure Wound Therapy in Obese Patients Undergoing Laparotomy:  A Randomized Study 
 
 
Appendix I – Patient Eligibility Checklist  
Negative Pressure Wound Therapy in Obese Patients Undergoing 
Laparotomy for Gynecologic or Other Abdominal Cancer: A 
Randomized Controlled Trial 
 
Eligibility Checklist – page 1 of 1 
Patient initials   
     
 
Patient ID   
  (assigned in OnCore) 
 
 
INCLUSION CRITERIA  
A “NO” response to any of the following disqualifies the patient from study entry. 
 
 
EXCLUSION CRITERIA 
A “YES” response to any of the following disqualifies the patient from study entry. 
 
 
Yes      No 
5. 
 Known true tape allergy 
 
 
6. 
 Sensitivity to silver 
 
 
7. 
 History of intolerance to Negative Pressure Wound Therapy 
 
 
 
Date consent form signed: 
 
 
 
 
Having obtained consent and reviewed each of the inclusion/exclusion criteria, I verify that this patient 
is:  
 
  Eligible 
  Ineligible    Date registered  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Signature of person verifying eligibility 
 
 
 
 
Date 
 
 
Treatment Assignment:  
 - SOC        
 - NPWT 
 
 
Yes      No 
1. Known or suspected gynecologic or other abdominal malignancy (such as colorectal, liver, 
pancreatic, kidney and stomach) for which laparotomy is planned 
 
 
2. Obese – defined as a Body Mass Index (BMI) ≥ 35 kg/m2 as calculated in the Epic computer 
record 
 
 
3. 18 years of age or older 
 
 
4. Able and willing to provide written consent  
 
 
 
 
 
 
December 9, 2013 
Page 16 of 16 
CPRC #2013NTLS073