Relation of Skin Closure Method to Groin Wound Infections After Proximal Femoral Artery Exposure, a Randomized Clinical Trial
Phase: NA
Conditions: Surgical Wound Infection
Sponsor: Turku University Hospital

COVER PAGE 
 
 
Relation of skin closure method to groin wound infections after proximal 
femoral artery exposure, a randomized clinical trial 
 
15.3.2018 
 
 
M.D. Veikko Nikulainen 
Turku University Hospital 
Vascular Surgery Department 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Research plan 
 
 
 
 
 
 
 
 
 
 
 
Relation of skin closure method to groin wound infections after proximal 
femoral artery exposure, a randomized clinical trial 
 
 
Veikko Nikulainen, MD 
TYKS TO3, Verisuonikirurgisen potilaan hoito 
PL52, FI-20521 Turku 
veikko.nikulainen@tyks.fi 
+358 2 313 0000 

ABSTRACT 
 
Background: According to published studies the frequency of groin wound infections after 
peripheral revascularization varies substantially depending on the source from 5% up to 27%. 
Aims of the study: The aim of this randomized clinical trial is to evaluate whether the number of 
groin wound infections can be reduced with an intradermal skin suture compared to the 
commonly used metal staples skin closure method. 
Methods and study design: We will perform a randomized clinical trial of patients undergoing a 
vascular procedure which includes an incision in the groin. The patients will be randomized (1:1) to 
two different wound closure techniques: subcuticular suture or metal staples. After the procedure 
the patients will be controlled for four to six weeks and the infection rate in each group is 
recorded. A clinical diagnosis of infection according to Centre for Disease Control (CDC) guidelines 
will be recorded, no microbiological samples will be routinely collected. 
Statistical analysis: A power analysis has been conducted based on Finnish RCT studies and a 
retrospective study from our own hospital (submitted to Annals of Vascular Surgery 1/2018) which 
included all isolated groin wounds from Turku University Hospital Vascular Surgery clinic 2015-
2016 and total of 626 patients, 313 per group will be enrolled in the study. Differences in 
infections between the groups will be evaluated using univariable and multivariable logistic 
regression analyses. 
Time and schedule: This is a multicenter trial. Ethical committee approval was acquired in 2015. 
The randomization will start in the spring of 2018 in the University Hospital of Turku. Later in the 
year in the other hospitals that are participating in the study once the regional authorities have 
given their consent. 
Ethical aspects: Ethical committee approval was obtained in 2015. The wound closure techniques 
are all in everyday use already, nothing new and experimental will be used. 
Budget: This study is a critical part of quality control and improvement in vascular surgery. The 
funding will be applied from the Finnish Academy and EVO funding from the ERVA. 
 
 

INTRODUCTION 
 
The groin is a common site for arterial access in vascular surgery; it is also a frequently infected 
wound. According to published articles the frequency of groin wound infections after peripheral 
revascularization varies substantially depending on the source from 5% up to 27%1-5. 
 
Although the percentage of superficial groin infections is considerably high, the incidence of deep 
infections of the possibly prosthetic graft materials is significantly lower, between 0% and 3.1% 6-9 
 
Surgical wound infections (SWI) is defined as an infection that occurs within 30 days of surgery 
when autogenous material is used, but when prosthetic materials are used the incidence of SWI is 
calculated for one year after the initial operation. The infection occurs primarily as a result of 
contamination by skin organisms during or right after surgery. When these pathogens infiltrate 
deeper into the tissues they can cause an infection of the prosthetic material6,10. 
 
The high incidence of infection after peripheral vascular surgery compared to other clean surgery 
in both patient- and procedure related. Patients undergoing surgery for peripheral vascular 
disease are often frail and have typically multiple co-morbidities; they are in high risk for 
developing post-operative infections. They often have many pre-existing risk-factors for SWI and 
hospital acquired infections (HAIs) 11.  This risk is associated with cardiovascular risk factors, 
degree of ischemia in the operated limb and operative method12.  Procedure related risks include 
long operation time13, which is related to hypothermia, inadequate antibiotic prophylaxis and 
breaks in sterility.  Critical ischemia, rest pain and ischemic ulcer are also independent risk-factors 
for SWI14. 
 
SWI causes additional costs for vascular surgery procedures as it lengthens the hospitalization 
period and requires additional treatments. The length of hospitalization is prolonged by 2-14 days 
due to SWI15,16. A recent Finnish article concluded that the cost for SWI after a revascularization 
operation was 3320e2. 
 
Numerous studies have been conducted investigating the best infection prevention schemes in 
vascular surgery. Andrew H. Stewart el al. 17have done a meta-analysis of 34 studies to determine 

the effectiveness of perioperative strategies in infection prevention. They reviewed 34 
randomized controlled trials of these 22 were trial of prophylactic systemic antibiotics, 3 of 
rifampicin-bonded grafts, 3 of preoperative skin antisepsis, 2 of suction wound drainage, 2 of 
minimally invasive in situ bypass techniques and individual trials of intraoperative glove change 
and wound closure technique18. They concluded that systemic prophylactic antibiotics reduced the 
risk for infection but no significant reduction in other infection prevention methods was 
discovered 
 
The surgical wound in the groin in vascular surgery is traditionally closed using transdermal closure 
techniques i.e. metal staples or traditional non-absorbable sutures.  Gurusamy et al. 19 conducted 
a large Cochrane database review in 2014 on skin closure techniques in all non-obstetric surgery, 
they concluded that wound dehiscence may be reduced by using subcuticular absorbable sutures. 
This subcuticular wound closure method is widely adopted to use in for example plastic surgery. 
 
AIMS OF THE STUDY 
 
Patients undergoing peripheral revascularization procedures have many pre-existing risk factors 
for surgical wound infection. These cannot be reduced. Studies have shown that prophylactic 
antibiotics can reduce the number of surgical wound and infections and other hospital acquired 
infections. The above-mentioned Cochrane database review also stated that wound dehiscence 
can be reduced by using subcuticular wound closure methods. 
 
The aim of this randomized clinical trial is to evaluate whether the numbers of surgical wound 
infections in patients undergoing peripheral vascular revascularization procedures can be reduced 
using the above-mentioned subcuticular wound closure method compared to the golden-standard 
metal staples.  
 
METHODS AND STUDY DESIGN 
 
Setting 
This is a randomized multicenter clinical trial. The trial is coordinated from the University Hospital 
of Turku Vascular Surgery Department. The other participating hospitals are North Karelia Central 

Hospital, Satakunta Central Hospital and Jyväskylä Central Hospital. These are all large volume 
central hospitals that manage demanding vascular surgery patients with a 24h on-call vascular 
surgery resource. 
 
Corresponding researches in the other participating hospitals are: 
MD Veikko Nikulainen, Turku University Hospital 
MD, PhD Tuomas Koskinen, Satakunta Central Hospital(tuomas.koskinen@satshp.fi) 
MD, PhD Johanna Turtiainen, North-Karelia Central Hospitaljohanna.turtiainen@siunsote.fi) 
MD, PhD Tiia Kukkonen, Jyväskylä Central Hospital (tiia.kukkonen@fimnet.fi) 
 
Patient recruitment 
The patients enrolled in this trial are patients that have an isolated groin wound (i.e. the groin 
wound is not a part of a larger wound in the same limb). Only patients that are undergoing 
primary procedures are included. Emergency procedures (puncture site hematomas) are also 
excluded from the trial as are patients operated for surgical site infections and pseudoaneurysm. 
 
Randomization  
The patients will be randomized (1:1) to two different wound closure techniques: subcuticular 
suture or metal staples. The type of subcuticular suture material is not standardized, all 
participating hospitals use whatever suture they are accustomed to. After the procedure the 
patients will be controlled for four to six weeks and the infection rate in each group is recorded. A 
clinical diagnosis of infection according to Centre for Disease Control (CDC) guidelines will be 
recorded20, no microbiological samples will be routinely collected. 
 
Data recording 
The following data will be collected from the operation monitoring system to an Excel-file: age, 
gender, diagnosis and body mass index (BMI) of the patient, indication and urgency of the 
operation and whether it was performed by the hybrid or a traditional approach. It will be 
recorded whether the prophylactic antibiotic was given accordingly. Known risk factors for SWI are 
recorded from the patient data system, these included peripheral artery disease (PAD), presence 
of critical limb ischemia (CLI), hypertension, diabetes, rheumatoid arthritis, smoking and 

immunosuppressive medication. The condition of the patients’ skin will also be recorded in the 
file. 
 
Statistical analysis 
A power analysis has been conducted based on a prospective Finnish study2 and a retrospective 
study from our own hospital (submitted to Annals of Vascular Surgery 1/2018) which included all 
isolated groin wounds from Turku University Hospital Vascular Surgery clinic 2015-2016. Sample 
size calculations were based on two-sided Pearson’s χ2 -test for two proportions. Sample size was 
calculated from an estimated infection rate of 20% in the transdermal wound closure group. A 
decrease of 10 percentage points in infection rate is considered clinically important difference 
leading to estimated 10% infection rate in the intradermal wound closure group. To detect this 
difference with a power of 0.9 (1-β) and two-sided significance level (α) of 0.05 266 patients per 
group is needed. With an estimated drop-out rate of 15% total of 626 patients, 313 per group will 
be enrolled in the study. Sample size calculations were performed using Power procedure in SAS 
System for Windows, Version 9.4 (SAS Institute Inc., Cary, NC). 
 
Categorical variables of the study will be characterized by group using frequencies and percents 
and for continuous variables means and standard deviations or medians with range and 25th and 
75th percentiles will be used. Differences in patient characteristics between groups will be tested 
using two-sample t-test or Pearson’s χ2 –test. Differences in infections between the groups will be 
evaluated using univariable and multivariable logistic regression analyses. The study site 
differences will be evaluated in statistical models and if major differences are detected, then study 
site will be taken into account in the analyses. Two-sided p-values less than 0.05 will be considered 
statistically significant. The subjects with missing data will automatically be excluded from the 
analyses of the variables in concern. Statistical analyses will be performed using SAS System for 
Windows, Version 9.4 or later (SAS Institute Inc., Cary, NC). 
 
TIME AND SCHEDULE  
 
This is a multicenter trial. Ethical committee approval was acquired in 2015. The randomization 
will start in the spring of 2018 in the University Hospital of Turku. Later in the year in the other 
hospitals that are participating in the study once the regional authorities have given their consent. 

 
Based on our retrospective material our clinic has ca. 130 patients annually undergoing a 
procedure with an isolated groin wound. Our estimates are that it will take approximately 2 years 
between the four participating centers to gather the needed patient material. By this calculation 
the material should be ready and analyzed during years 2020- 2021. 
 
ETHICAL ASPECTS  
 
Ethical committee approval was obtained already in 2015 for the University Hospital of Turku. The 
consent from the local ethical authorities has been filed for the other participating hospitals in the 
beginning of 2018. The wound closure techniques are all in everyday use already, nothing new and 
experimental will be used. 
 
BUDGET 
 
This study is a critical part of quality control and improvement in vascular surgery. The funding will 
be applied from the Finnish Academy and EVO funding from the ERVA. 
 
 

REFERENCES 
 
1. 
Childress BB, Berceli SA, Nelson PR, Lee WA, Ozaki CK. Impact of an absorbent silver-eluting 
dressing system on lower extremity revascularization wound complications. Ann Vasc Surg. 
2007;21(5):598-602. doi:10.1016/j.avsg.2007.03.024. 
2. 
Turtiainen J, Saimanen E, Partio T, et al. Surgical wound infections after vascular surgery: 
prospective multicenter observational study. Scand J Surg. 2010;99(3):167-172. 
doi:10.1177/145749691009900312. 
3. 
Turtiainen J, Saimanen EIT, Partio TJ, et al. Supplemental postoperative oxygen in the 
prevention of surgical wound infection after lower limb vascular surgery: a randomized 
controlled trial. World J Surg. 2011;35(6):1387-1395. doi:10.1007/s00268-011-1090-y. 
4. 
Turtiainen J, Saimanen EIT, Mäkinen KT, et al. Effect of triclosan-coated sutures on the 
incidence of surgical wound infection after lower limb revascularization surgery: a 
randomized controlled trial. World J Surg. 2012;36(10):2528-2534. doi:10.1007/s00268-012-
1655-4. 
5. 
Derksen WJM, Verhoeven BAN, van de Mortel RHW, Moll FL, de Vries J-PPM. Risk factors 
for surgical-site infection following common femoral artery endarterectomy. Vasc 
Endovascular Surg. 2009;43(1):69-75. doi:10.1177/1538574408323502. 
6. 
Piano G. Infections in lower extremity vascular grafts. Surg Clin North Am. 1995;75(4):799-
809. 
7. 
Giacometti A, Cirioni O, Ghiselli R, et al. Efficacy of quinupristin-dalfopristin in preventing 
vascular graft infection due to Staphylococcus epidermidis with intermediate resistance to 
glycopeptides. Antimicrob Agents Chemother. 2002;46(9):2885-2888. 
doi:10.1128/AAC.46.9.2885-2888.2002. 
8. 
Kimmel RM, Murphy RX, Chowdary RP. Optimal management of inguinal vascular graft 
infections. Ann Plast Surg. 1994;32(6):623-629. 
9. 
LaMuraglia GM, Fischman AJ, Strauss HW, et al. Utility of the indium 111-labeled human 
immunoglobulin G scan for the detection of focal vascular graft infection. J Vasc Surg. 
1989;10(1):20–7–discussion27–8. 
10. 
Antonios VS, Noel AA, Steckelberg JM, et al. Prosthetic vascular graft infection: a risk factor 
analysis using a case-control study. J Infect. 2006;53(1):49-55. 
doi:10.1016/j.jinf.2005.10.004. 
11. 
Wipke-Tevis DD. Vascular infections: medical and surgical therapies. J Cardiovasc Nurs. 
1999;13(2):70-81. 
12. 
Daryapeyma A, Östlund O, Wahlgren C-M. Healthcare-associated infections after lower 
extremity revascularization. Eur J Vasc Endovasc Surg. 2014;48(1):72-77. 
doi:10.1016/j.ejvs.2014.02.003. 

13. 
Greenblatt DY, Rajamanickam V, Mell MW. Predictors of surgical site infection after open 
lower extremity revascularization. J Vasc Surg. 2011;54(2):433-439. 
doi:10.1016/j.jvs.2011.01.034. 
14. 
Ott E, Bange F-C, Sohr D, Teebken O, Mattner F. Risk factors associated with surgical site 
infections following vascular surgery at a German university hospital. Epidemiol Infect. 
2013;141(6):1207-1213. doi:10.1017/S095026881200180X. 
15. 
Giles KA, Wyers MC, Pomposelli FB, Hamdan AD, Ching YA, Schermerhorn ML. The impact of 
body mass index on perioperative outcomes of open and endovascular abdominal aortic 
aneurysm repair from the National Surgical Quality Improvement Program, 2005-2007. J 
Vasc Surg. 2010;52(6):1471-1477. doi:10.1016/j.jvs.2010.07.013. 
16. 
O'Brien R, Pocock N, Torella F. Wound infection after reconstructive arterial surgery of the 
lower limbs: risk factors and consequences. Surgeon. 2011;9(5):245-248. 
doi:10.1016/j.surge.2010.10.005. 
17. 
Stewart AH, Eyers PS, Earnshaw JJ. Prevention of infection in peripheral arterial 
reconstruction: A systematic review and meta-analysis. J Vasc Surg. 2007;46(1):148-155. 
doi:10.1016/j.jvs.2007.02.065. 
18. 
Murphy PG, Tadros E, Cross S, et al. Skin closure and the incidence of groin wound infection: 
a prospective study. Ann Vasc Surg. 1995;9(5):480-482. doi:10.1007/BF02143863. 
19. 
Gurusamy KS, Toon CD, Allen VB, Davidson BR. Continuous versus interrupted skin sutures 
for non-obstetric surgery. Gurusamy KS, ed. Cochrane Database Syst Rev. 
2014;42(2):CD010365. doi:10.1002/14651858.CD010365.pub2. 
20. 
YANGCO B. CDC definitions for nosocomial infections. American Journal of Infection Control. 
1989;17(1):42-43. doi:10.1016/S0196-6553(89)80013-6.