A Randomized Clinical Trial Comparing Partial and Complete Wound Closure in the Prevention of Surgical Site Infection among Adult Patients Undergoing

Emergency Colon Resection

 

 

 

 

Alfred D. Troncales, MD

Ma. Cecilia T. Leyson, MD

Rodney L. Dofitas, MD, FPCS

Reynaldo O. Joson, MD, MHA, MHPEd, MS Surg

 

 

 

 

 

 

 

 

 

Abstract:

            Background: In the Department of Surgery, Hospital X, the incidence of surgical site infection after emergency colon resection has been a primary concern.  Despite the use of antibiotics and other prophylactic maneuvers, it still belongs to the top 3 causes of post-operative morbidity as of 2001.

            Objective:  To determine if the type of wound closure could affect the incidence of surgical site infection (SSI) in emergency colon resection we compared the incidence of SSI between partial (PWC) and complete wound closure (CWC) and analyzed potential factors that may have contributed to any difference.

            Methods:  A randomized clinical trial was conducted from January 2002 to June 2003 wherein patients undergoing emergency colon resection were closed either partially at the skin-subcutaneous layer or completely and the wound observed for 28 days.  Purulent discharge from the incision site was used as the indicator of SSI.   

            Results:  A total of 29 patients was accrued, 14 of whom had CWC while 15 had PWC.   The incidence of SSI was 57 per cent and 20 per cent in CWC and PWC respectively.  Among the factors analyzed, there was a tendency for physical status, degree of obstruction, and left-sided colon resection to be contributors to the high SSI rates in CWC.

            Conclusion:  For patients undergoing emergency colon resection, partial wound closure seems to be an effective method in minimizing the risk of

 

developing surgical site infection.  A multi-center study will be undertaken to accrue more patients to validate the results of this study. 

 

Key Words: Surgical site infection, partial wound closure, complete wound closure, emergency colon resection

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Introduction

            The incidence of infection of abdominal incisions after emergency colon resection was reported to be in the range of 20 to 40 per cent1 despite the use of antibiotics and other prophylactic maneuvers.

            In the institution of the authors, surgical site infection ranked first as a cause of post-operative morbidity for the past 2 years (2000 and 2001) and emergency colon surgery was among the top 3 procedures developing surgical site infection.  Infection developed despite the use of antibiotics and other prophylactic maneuvers like copious washing and protection of wound from contamination.

            During the monthly and annual audit conferences, the staff poised the question - are there other maneuvers that can be done to avoid the development of surgical site infection in emergency colon resections.  The usual practice had been to close all wounds primarily, that is, a complete skin-subcutaneous closure after fascial suturing.  After brainstorming and consensus gathering, a trial comparing partial and complete wound closure was decided upon.  The main reasons for considering a partial wound closure were: 1) leaving skin-subcutaneous wounds open is the best maneuver to avoid a surgical site infection in dirty operative procedures; 2) a fully gaping skin-subcutaneous wound is an objectionable sight from the point of view of patients; and 3) a partially gaping skin-subcutaneous wound may be easier to accept.  Thus, the

 

 

 primary objective of the study was to compare the prevalence rates of surgical site infection in partial and complete abdominal skin-subcutaneous wound closure after emergency colon resections.  A secondary objective is to analyze for potential factors that might contribute to any difference that may occur.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Methods

            The study was a randomized clinical trial conducted from January 2002 to June 2003 which included all patients more than 18 years old who underwent emergency colon resection.  Emergency meant operation done within 24 hours after diagnosis of a surgical disorder.      

            Before the implementation of the study, patients were already randomized into partial and complete wound closure using a “drawing-lot” method.  In consideration of the scarcity of prospective subjects for the study in the Department, an initial trial sample size of 15 patients per arm was decided upon. Partial wound closure (PWC) was defined as closure of the skin and subcutaneous tissue in one layer with a 2-0 non-absorbable monofilament suture interruptedly placed 2 inches apart.  Complete wound closure (CWC) on the other hand was closure of skin and subcutaneous tissue with a 4-0 non-absorbable monofilament suture interruptedly placed 2 centimeters apart.  All patients received pre-operative antibiotics of metronidazole 500 mg intravenously (IV) and gentamycin 80 mg IV within one hour prior to anesthestic induction.  These antibiotics were continued up to the third postoperative day and then discontinued.  Patients were evaluated daily for one week while still confined in the hospital and then weekly for four weeks.  Surgical site infection was determined by the presence of purulent drainage, without laboratory confirmation2, from the incision site.  There was no surgical site infection if there was no purulent discharge from the incision site up to the 28th day post-operative. 

 

            The operations were done by different senior residents.  Follow-up for SSI was done by the junior authors.  Due to the small sample size, differences and trends were determined in terms of prevalence rates and other descriptive statistics and not analytical statistics.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Results

            A total of 29 patients who underwent emergency colon resection were accrued as of June, 2003.  Of this, male patients comprised majority of the subjects (25 males vs. 4 females).  Fourteen of the 29 patients underwent complete wound closure (CWC) while the remaining 15 had partial wound closure (PWC) . 

The subjects in the two arms were more or less comparable in terms of sex and age distribution (Table 1); co-morbidities (Table 2); physical status (Table 3); side of colon resection (Table 4); and presence and degree of intestinal obstruction (Table 5).

            The SSI rate in CWC was 57 per cent while that in PWC was 20 per cent (Table 6).   There was no mortality and no anastomotic leak in these 29 patients.  Resection-anastomosis was done in 83 per cent of cases.

            Attempts were done to analyze for factors that might contribute to the high SSI rates specifically physical status, presence of co-morbid conditions, side of colon resection, and presence and degree of intestinal obstruction. 

Physical status (PS):

            The overall SSI rates were 100 per cent for PS III-E, 50 per cent for PS II-E and 20 per cent for PS I-E (Table 7).  There was a tendency for SSI rates to rise with increasing PS, overall as well as in the two arms (CWC and PWC).  There was also a tendency for PWC as compared to CWC to reduce the SSI rates in PS I-E and PS II-E. 

 

Co-morbid conditions:

            The overall SSI rates were 75 per cent in those patients with co-morbid conditions and 24 per cent in those without (Table 8).  There was a tendency for SSI rates to rise in the presence of co-morbid conditions.  There was a tendency for PWC to reduce the SSI rates in patients with no co-morbid conditions but not in those with co-morbid conditions.

Side of colon resected:

            For ease of analysis, the transverse and left-sided resections were lumped together as left-sided resections.  The overall SSI rates were 45 per cent and 33 per cent for left-sided and right-sided colon resections respectively (Table 9).  There was a tendency for PWC to reduce the SSI rates in both left and right colon resection.

Presence of intestinal obstruction:

            The overall SSI rates were 48 per cent, 25 per cent, and 17 per cent in those with complete, partial, and without intestinal obstruction respectively (Table 10).  There was a tendency for PWC to reduce the SSI rates in patients with complete intestinal obstruction.

 

 

 

 

 

 

Discussion

            Surgical site infection (SSI) after emergency colon resection is a concern among surgeons and more so, the patients.  Firstly, by itself, SSI is an unwanted adverse event.  Secondly, the reported incidence could reach as high as 40 per cent1.

            In the Philippines and even internationally, data on the incidence of SSI after colon resection, both elective and emergency, are scarce, and if present, variable, more so on the emergency cases.  In view of the absence of reliable data, the authors in analyzing and discussing the results of this study would just have to contend with whatever data are available in the literature and data gotten from studies on elective colon surgery or combined elective and emergency cases, with the assumption that the incidence of SSI is higher in emergency than in elective cases. 

            In a 1994 report by the Philippine College of Surgeons (PCS) on postoperative infection rates in six pilot hospitals4, the overall SSI rate after colorectal surgery was 7.5 per cent, with a range of 2.2 to 13.8 per cent from one hospital to another.  These figures covered both elective and emergency operations and all sorts of colorectal operations including those for hemorrhoids and fistulas-in-ano, making the figures on the low side if only colorectal resections are considered, and more so, if limited to emergency cases.

            Internationally, the data that the authors decided to use for this analysis and discussion came from two meta-analysis papers on the benefit of antibiotics

 

in colorectal surgery.   Baum in 19815, utilizing 26 trials from 1965 to 1980, reported a 36 per cent infection rate in the control group versus 22 per cent in the group with antibiotics.  Song in 19986 utilizing 147 randomized clinical trials from 1984 to 1995 reported a 40 per cent wound infection rate in the control group versus 13 per cent in the antibiotic group.  Thus, the incidence of SSI after colorectal surgery could really reach as high as 40 per cent.  This figure could be higher in emergency colon resections.

            In Hospital X Surgery, since 2001, controlling wound infection or SSI has been included in its wide-scale quality improvement program.  It started with a significant reduction of SSI in ruptured appendicitis by leaving the skin-subcutaneous layer unsutured.  From this experience, the approach was considered for another condition with significantly high SSI rate, that of emergency colon surgery.  Thus, this study was done to test a strategy to reduce the incidence of SSI in emergency colon resection.  Leaving the skin-subcutaneous layer is the best guarantee against SSI; however, this might not be readily acceptable to the patients.  Thus, a trial of partial wound closure.

            At this point of the trial, although the sample size is still small, the results tended to show that PWC significantly reduces SSI after an emergency colon resection and therefore, could be a useful strategy.  In support of this recommendation for using PWC in reducing SSI are the following findings and arguments:

 

 

1.      In a study comparing laparoscopy (LCR) and open colonic resection (OCR), SSI occurred in 13.5 per cent of patients after LCR and in 10.9 per cent of patients after OCR7.  The extraction site for LCR was associated with a high incidence of complications compared to OCR.  The explanation was that the incision in the extraction site in LCR was more heavily contaminated and more air-tight in closure as compared to the bigger incisional wound in OCR.

2.      The almost 50 per cent reduction of SSI rates in PWC (20 per cent vs. 57 per cent in CWC) in this study parallels the same degree of reduction of SSI rates in those given antibiotics as shown in the meta-analysis of Baum (5) and Song (6). This suggests that PWC is a very strong factor and strategy in SSI reduction, approximating the efficacy of leaving the skin-subcutaneous layer unsutured in ruptured appendicitis and heavily contaminated abdominal wounds. 

3.      Trying other more efficacious but more expensive antibiotics against gram-negative and anaerobic organisms might be an option that the authors considered.  However, considering the financial constraints of the setting (government hospital as well as patients in the lower income strata), this option is not a sustainable proposition.

4.      Mechanical bowel preparation even if feasible in emergency cases, in a 2003 meta-analysis of 6 randomized control trials (8) did not show significant reduction in wound infection rate (7.4 per cent vs. 5.7 per cent in those without preparation).

 

5.      There are no randomized control trials on intra-operative colonic irrigation in the prevention of wound infections.  The reported wound infection rates associated with the use of intra-operative colonic irrigation are high at 10.81 per cent (9) and 29 per cent (10).  As to the risk factors for surgical site infection, in a study by Tang (11) in 2,809 consecutive patients undergoing elective colorectal resection via laparotomy between February 1995 and December 1998, the following were identified as overall risk factors: American Society of Anesthesiology (ASA) or Physical Status score 2 or

3, male gender, surgeons, types of operation, creation of an ostomy, contaminated wound, use of drainage, and intra- or postoperative blood transfusion.  In the study of Mandal (12) in colonic trauma, risk factors identified were left-sided colon injuries and ineffective antibiotics against anaerobic bacteria.  Statistical analysis on the different surgical methods used such as primary repair, primary repair with exteriorization, or colostomy, was indeterminable.  In this study, because of the small sample size, no definite conclusion can be made as to the risk factors in SSI in emergency colon resections.  However, the more reliable potential risk factors noted in this study were the physical status, degree of intestinal obstruction and left sided colon resection which may implicate degree of contamination of the surgical wound during the resection.  In conclusion, this pilot study shows that for patients undergoing emergency colon resection, partial wound closure seems to be an effective method in minimizing the risk of developing surgical site

 

infection.  A multi-center study will be undertaken to accrue more patients to validate the results of this study. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

References:

1.      Dunn DL. Surgery: Basic Science and Clinical Evidence, 1st ed. United States: Springer Verlag New York, Inc., 2001: 205-208

2.      Mangram AJ, Horan TC, Pearson ML, Silver LC, Jarvis WR. Guidelines for the Prevention of Surgical Site Infection, 1999.  Am J of Infection Control 1999: 27: 97-134  

3.      Howard RJ. Principles of Surgery, 7th ed. Singapore: McGraw-Hill Book Co, 1999: 130-131.

4.      Cortez ER; Ampil IDE; Laudico AV et al. Postoperative infection rates: a report on the PCS surgical infection surveillance system in six pilot hospitals. Philipp J Surg Spec 1994; 49(1):37-42.

5.      Baum ML, Anon DS, Chalmus TC, Sachs HS, Smith H.  A survey of clinical trials of antibiotic prophylaxis in colon surgery: evidence against further use of no treatment controls.  N Engl J of Med  1981; 305(14): 795-799.

6.      Song F, Glenny AM.  Antimicrobial prophylaxis in colorectal surgery: a systematic review of randomized control trials.  Br J Surg 1998; 85:1232-1241.

7.      Winslow ER, Fleshman JW, Birnbaum EH, Brunt LM. Wound complications of laparoscopic vs open colectomy. Surg Endosc 2002;16(10):1420-5.

8.      Guenaga KF, Matos D, Castro AA, Atallah AN, Wille-Jorgensen P.  Mechanical bowel preparation for elective colorectal surgery. Cochrane Database Syst Rev 2003;(2):CD001544.

 

 

 

9.  Sule A, Obepka PO, Iya D, Ogbonna B, Momoh J.  Intraoperative colonic       

     irrigation in the management of left sided large bowel emergencies in Jos

     University Teaching Hospital, Nigeria. East Afr Med J 2000;77(11):613-7.

10. Biondo S, Perea MT, Rague JM, Pares D, Jaurrieta E.  One-stage procedure in non-elective surgery for diverticular disease complications. Colorectal Dis 2001;3(1):42-5.

11. Tang R, Chen HH, Wang YL et al. Risk factors for surgical site infection after elective resection of the colon and rectum: a single-center prospective study of 2,809 consecutive patients. Ann Surg 2001;234(2):181-9.

12. Mandal AK, Thadepalli H, Matory E, Lou MA, O'Donnell VA Jr.  Evaluation of      

      antibiotic therapy and surgical techniques in cases of homicidal wounds of

      the colon. Am Surg 1984;50(5):254-7.

 

 

 



 


 

 

 

 

 

Table 1. Sex and age distribution of patients under the two arms.

 

CWC

N= 14

PWC

N=15

M:F

11:3

14:1

Age range

18-72 y/o

24-61 y/o

Mean age

37 y/o

38 y/o

> 45 years old

5

5

< 44 years old

9

10

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 2. Co-morbid condition.

Co-Morbidities

CWC

PWC

1. None

10

11

2. Presence 

Hypertension

Pulmonary TB

4

                2

                2

4 

            4

            0

Total

14

15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 3. Physical status.

Physical Status

CWC

PWC

 I-E

7

8

 II-E

7

5

III-E

-

2

IV-E

-

-

Total

14

15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 4. Side of colon resected.

Side of colon resected

CWC

PWC

1. Right Colon

7

11

2. Left Colon

5

-

3. Left and Transverse Colon

-

2

4. Transverse

2

2

Total

14

15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 5. Degree of obstruction.

Degree of Obstruction

CWC

PWC

1. Complete Obstruction

10

9

2. Partial Obstruction

2

2

3. Non-obstructed

2

4

Total

14

15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 6. Surgical site infection rate.  

Wound closure

Total Number

Infection

Infection Rate

1. Complete

14

8

57%

2. Partial

15

3

20%

Total

29

11

100%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 7. SSI rates based on physical status.

Physical status

Overall SSI rates

SSI rates in CWC

SSI rates in PWC

I –E

3/15 (20%)

3/7 (43%)

0/8 (0%)

II – E

6/12 (50%)

5/7 (71%)

1/5 (20%)

III – E

2/2 (100%)

-

2/2 (100%)

IV – E

-

-

-

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 8. SSI rates based on presence or absence of co-morbid conditions.

Co-morbid conditions

Overall SSI rates

SSI rates in CWC

SSI rates in PWC

Absent

5/21 (24%)

5/10 (50%)

0/11 (0%)

Present

6/8 (75%)

3/4 (75%)

3/4 (75%)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 9. SSI rates based on side of colon resected.

Side of colon resected

Overall SSI rates

SSI rates in CWC

SSI rates in PWC

Right side

6/18 (33%)

4/7 (57%)

2/11 (18%)

Left side

5/11 (45%)

4/7 (57%)

1/4 (25%)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 10. SSI rates based on degree of intestinal obstruction.

Degree of obstruction

Overall SSI rates

SSI rates in CWC

SSI rates in PWC

None

1/6 (17%)

1/2 (50%)

0/4 (0%)

Partial

1/4 (25%)

0/2 (0%)

1/2 (50%)

Complete

9/19 (48%)

7/10 (70%)

2/9 (22%)