- Email: [email protected]
Infectious complications in colonic surgery
ABSTRACTS AND COMMENTARY Current Surgery presents a comprehensive review of recent surgical and medical literature for the surgeon who wants to stay well informed in the least amount of time. Our international board of editors selects significant articles to review and provides commentary. The editorial board welcomes suggestions of topics or specific articles from our readers.
Colon/Rectal
Infectious Complications in Colonic Surgery Guest Reviewers: Soumitra R. Eachempati, MD, and John M. Daly, MD INTRAOPERATIVE COLONIC LAVAGE AND PRIMARY ANASTOMOSIS IN PERITONITIS AND OBSTRUCTION.
Biondo S, Jaurrieta E, Jorba R, et al. Br J Surg 1997;84:222–225. To evaluate differences in outcome in patients with peritonitis or obstruction who require left colonic resection and undergo on-table lavage with primary anastomosis.
Objective
A retrospective review of all patients undergoing emergency operations for a distal colonic lesion from January 1992 to August 1995.
Design
A tertiary medical facility associated with the University of Barcelona, Spain.
Setting
Of 212 patients who underwent emergency colonic surgery for distal lesions requiring resection during the study period, 63 patients were selected for primary anastomosis after on-table lavage. In this technique, the left colon is generously mobilized laterally along its peritoneal borders up to and including the splenic flexure. The cecum is cannulated with a 24 Fr Foley catheter either through the appendix or the terminal ileum. The end of left colon is brought outside the abdominal cavity on its mesentery and a colotomy is made. After the distal end is placed in a plastic bag, normal saline at 37°C is used to irrigate the colon until clear. After colonic irrigation, the rectum is irrigated and the bowel anastomosed in an end-to-end fashion. The authors used stapling devices for anastomoses constructed below the peritoneal reflection. Parenteral antibiotic therapy with metronidazole and gentamicin (or ciprofloxacin if the patient had depressed renal function) was used perioperatively and continued postoperatively if the patient had peritonitis.
Methods
Thirty-two men and 31 women underwent colonic lavage with resection and primary anastomosis. Criteria precluding lavage with primary anastomosis included irresectable colonic lesion (31 patients), proximal colonic damage (31 patients), circulatory instability (29 patients), advanced peritonitis (21 patients), and poor general medical condition (18 patients). The mean age of the patients was 61 6 13 years. Thirty-seven patients had a colorectal tumor. Indications for surgery were obstruction in 37 patients, acute abdominal inflammation in 24, ischemic rectal prolapse in 2, and diverticular hemorrhage in 1. Complications occurred in 21 of the 63 patients treated by
Results
CURRENT SURGERY
•
© 1999 by the Association of Program Directors in Surgery Published by Elsevier Science Inc.
0149-7944/99/$20.00
101
primary anastomosis after colonic irrigation. Three perioperative deaths and three clinically significant anastomotic leaks occurred. The most common complications were wound infections (10 patients) and prolonged paralytic ileus (6 patients). Conclusions
With appropriate selection, certain patients with colonic obstruction and peritonitis may safely undergo a one-stage procedure consisting of antegrade colonic lavage, bowel resection, and immediate colonic anastomosis. REVIEWER COMMENTS. Emergent left colon surgery involving resection is almost always managed with diverting colostomy in the United States. These authors in the United Kingdom reviewed their experience with primary anastomosis after on-table lavage for emergent left colon surgery. Their excellent description of the technique of on-table lavage provides valuable knowledge for the surgeon or surgeon-in-training and should be used as an available reference. Their results demonstrate that primary anastomosis can be performed in left colon surgery with modest morbidity, as 21 of their 63 patients had a complication. These results may be acceptable because the patients required emergency operations and did not have to undergo the morbidity of a subsequent colostomy takedown. The importance of this article is that the reader will become aware that options to mandatory colostomy may exist in emergent left colonic surgery requiring resection. A DOUBLE-BLIND, RANDOMIZED STUDY OF 3 ANTIMICROBIAL REGIMENS IN THE PREVENTION OF INFECTIONS AFTER ELECTIVE COLORECTAL SURGERY.
Jewesson P, Chow A, Wai A, et al. Diagn Microbiol Infect Dis 1997;29:155–165.
102
Objective
To determine which of three antimicrobial regimens, either cefoxitin, ceftizoxime, or metronidazole with gentamicin was most effective at preventing infection in colorectal surgery.
Design
A randomized, double-blind, prospective clinical trial in a Canadian tertiary care teaching hospital from November 1990 to April 1993.
Setting
The study was conducted at Vancouver Hospital, a 1000-bed tertiary care hospital affiliated with the University of British Columbia.
Participants
Patients older than 19 years, excluding actively lactating or pregnant women, scheduled for an elective colorectal procedure who had none of the following other exclusion criteria were eligible: clinical or microbiologic evidence of infection within 48 hours of surgery, an antibacterial agent administered within 7 days of surgery, evidence of complete bowel obstruction, or a history of a hypersensitivity reaction to the study drugs.
Methods
A computerized random number generator was used to randomize each patient into one of three study drug regimens: (1) 1000 mg of ceftizoxine; (2) 1000 mg of cefoxitin; (3) 500 mg of metronidazole plus 120 mg of gentamicin. The drugs were administered within 15–30 minutes of the onset of surgery, and at 12 and 24 hours postoperatively. An additional 8 doses of study drugs were given at 12-hour intervals to patients deemed at high risk for infection (ie, bowel ischemia, perforation, HIV seropositivity, cirrhosis, current steroid usage, and diabetes mellitus). All patients received mechanical bowel preparation by mouth after a minimum 3– 4 hour fast on the day before surgery. Surgical wounds were classified as class I–IV, with I being no infection and IV being a widespread infection requiring systemic antibiotics. A previously described “ASEPSIS” scoring system was used to grade surgical wound sites before discharge. Data were prospectively collected and retrospectively analyzed in a blinded fashion.
Results
During the 30-month study, 153 patients were enrolled, of which 122 (38 ceftizoxime, 45 metronidazole-gentamicin, and 39 cefoxitin) completed the study. No demographic differences among the 3 groups were noted in terms of sex, age, weight, colorectal characteristics, or comorbidities. Superficial wound infections occurred in 5 cefoxitin patients and 1 metronidazole-gentamicin patient. Deep subcutaneous wound infections were seen in 6 metronidazole-gentamicin patients and 4 cefoxitin patients. One widespread infection (class IV) was seen in a cefoxitin patient. Overall mean ASEPSIS scores for the cefoxitin (mean 9.2) and metronidazole-gentamicin (mean 10.4) groups were higher (p 5 0.01) than those for the ceftizoxime group (mean 2.3).
Conclusions
These data suggest that ceftizoxime is superior to cefoxitin and metronidazole-gentamicin in the prevention of colorectal surgical wound infections. CURRENT SURGERY
•
Volume 56 / Number 3 • March/April 1999
REVIEWER COMMENTS. Wound infections are a costly morbidity for elective colon surgery. The study demonstrates that different therapies may not prevent wound infections equally. This well-designed study concluded that ceftizoxime was the best agent of those studied for the prevention of the complication of wound infection. Because so many different therapies can be used for this surgery, a study proving which antibiotic therapy is the best is nearly impossible to perform. Nevertheless, the study provides valuable information in that it examines the results of several common therapies. Perhaps most importantly, in detailing the method of determining an ASEPSIS score, the study provides a model for future studies in the analysis of wound morbidity in colon surgery. Interestingly, the authors gave their high-risk patients 10 postoperative doses. This approach has been questioned recently and provides the question for a subsequent study. IS MECHANICAL BOWEL PREPARATION REALLY NECESSARY FOR ELECTIVE LEFT-SIDED COLON AND RECTAL SURGERY?
Memon MA, Devine J, Freeney J, From SG. Int J Colorect Dis 1997;12:298 –302. To determine whether mechanical bowel preparation is necessary for elective left-sided colon and rectal surgery.
Objective
A review of infectious and perioperative complications of patients with and without mechanical bowel preparation who underwent left-sided colorectal surgery at a single hospital between January 1, 1992, and December 31, 1994.
Design
A single teaching hospital, Whiston Hospital, in Merseyside, United Kingdom.
Setting
One hundred thirty-six patients undergoing elective left-sided colon surgery by 1 of 5 surgeons, varying from consultant to senior house officer.
Participants
Patients who underwent left-sided colon surgery within the study period were nonrandomly assigned to undergo surgery with or without mechanical bowel preparation depending on whether the operating surgeon was in the group of surgeons who routinely omitted the use of the mechanical bowel preparation (MBP) for elective colonic surgery. The majority of patients (93.4%) received single-dose intravenous antibiotics at the time of induction of anesthesia.
Methods
Sixty-one patients received preoperative mechanical bowel preparation for elective left-sided colonic surgery and 75 patients underwent operations without any mechanical preparation. The patients in each group were similar in age (61.2 vs 64.7), sex, and disease pattern. One hundred twenty-four patients had drains placed in the peritoneal cavity or perineum, the majority of which were of the closed-suction variety. The mean interval after the operation when the drains were removed was not significantly different in either group. The average hospital stay was 13.2 days in the MBP group vs 15.2 in the non-MBP group (p 5 0.3560). The incidences of wound infections (6.6% in MBP vs 13.3% in the non-MBP group), wound dehiscences (3.3% in the MBP vs 5.3% in the non-MBP group), abdominal or pelvic collections (4.9% in the MBP group vs 2.7% in the non-MBP group), and anastomotic breakdowns (8.2% in the MBP group vs 2.7% in the non-MBP group) were not significantly different between the two groups. Two patients died, both of whom had received MBP. One of these deaths was related to an anastomotic dehiscence.
Results
Mechanical bowel preparation may confer no discernible advantage in decreasing infectious and perioperative mortality in patients undergoing elective left colon and rectal surgery.
Conclusions
REVIEWER COMMENTS. Mechanical bowel preparation in some fashion has become a routine for elective colonic surgery. These authors question its utility for this indication based on a retrospective, nonrandomized analysis. Unfortunately, the study cannot demonstrate a difference between outcomes in patients treated with or without MBP. They suggest that their results hinge on the skills of the individual surgeons involved and not the use of MBP. This study is important because it questions the rationale of a therapy associated with some cost and morbidity, and its results may provide a springboard for a prospective, randomized, multicenter trial to answer whether MBP is necessary in elective colonic surgery. ANTIMICROBIAL PROPHYLAXIS IN COLORECTAL SURGERY: A SYSTEMATIC REVIEW OF RANDOMIZED CONTROLLED TRIALS.
Song F, Glenny AM. Br J Surg 1998;85:1232–1241. CURRENT SURGERY
•
Volume 56 / Number 3 • March/April 1999
103
Objective
To determine the relative efficacy of antimicrobial prophylaxis for the prevention of postoperative wound infection in patients undergoing colorectal surgery.
Design
This study is a review of previously published studies analyzing different antimicrobial regimens in preventing wound infections in colorectal surgery.
Setting
The current authors from the University of York reviewed work mainly from teaching hospitals.
Participants
Patients undergoing elective colorectal surgery at the respective hospitals of the authors.
Methods
The authors reviewed randomized controlled trials between 1984 and 1995 by searching MEDLINE, EMBASE, and the Cochrane Trials Register with the assistance of the NHS Center for Reviews and Dissemination of York, United Kingdom. The rate of surgical wound infection was used as the principal outcome measure. Attempts were made to include only abdominal wound infections. When several trials used the same groups of antibiotics, a formal metaanalysis was performed. This paper presented the results of trials evaluating a regimen containing cefuroxime plus metronidazole or a regimen containing gentamicin plus metronidazole. A special focus here also included the analysis of the newer generation of cephalosporins, certain combinations of antibiotics, and the relative efficacy of single versus multiple doses of antibiotic therapy.
Results
One hundred forty-seven trials were analyzed. Generally, more multicenter and more large trials were conducted recently. In the 4 trials using no antibiotics as a control group, the wound infection rate was much higher in the control group (40 % in the control group vs 13% in the treated group). Cefuroxime plus metronidazole was more effective than metronidazole alone and equal to other single agent regimens such as imipenem, cefotetan, and cefoxitin. Intravenous gentamicin and metronidazole was superior to oral erythromycin and neomycin. The difference in infection between a first- and second- or third-generation cephalosporin was not significant. In pooling 17 trials, no advantage was seen in giving multiple antibiotic doses over single doses.
Conclusions
Antimicrobial prophylaxis decreases surgical wound infection in colorectal surgery. Single-dose regimens may be equal to multiple-dose regimens in achieving this goal. The optimal prophylaxis contains antibiotic activity against both aerobic and anaerobic bacteria. REVIEWER COMMENTS. The benefit of antibiotics in many types of surgeries is being analyzed. Through an ambitious review, the authors demonstrated somewhat conclusively that antibiotics are beneficial in colonic surgery. They also showed that a single dose of antibiotics was probably equivalent to multiple-dose therapy. They did not provide any cost analysis, but the implication of substantial savings obviously exists for single-agent therapy. The authors would have liked to show which regimen was optimal for the prophylaxis of wound infections in colonic surgery. However, in most of their analyzed studies, the antibiotic regimens differed. Therefore, the study failed to capture definitively which particular therapy provided the best prophylaxis. An important conclusion of the study that merits further validation was that first-generation cephalosporins may be equivalent in efficacy to the later generation agents. Last, the authors reinforce an important point: The best results for antibiotic prophylaxis occur when the tissue concentration of the agent is sufficiently high when bacterial contamination occurs.
SUMMARY Different types of colonic surgery vary greatly in their propensity for infectious complications.1,2 Elective resections with prepared bowel have more clearly associated morbidity than emergent colonic resections with unprepared bowel. Traditionally, complications have been thought to be minimized by the avoidance of primary anastomosis in emergent and unprepared colonic cases. Each article reviewed addresses different questions in the spectrum of possible colonic operations. Two of the articles review important factors regarding antibiotic use in elective surgery, and the other two challenge some staunchly held beliefs related to colon surgery. Since the 1970’s, mechanical bowel preparation (MBP) has been a widely practiced feature of elective colonic surgery.
104
The standard preparation has included a large volume of orally ingested cathartic with multiple doses of antibiotic base. These preparations were thought to decrease infectious complications by decreasing fecal loading through the cathartic effect and with the bases also minimize intraluminal bacterial counts. Additionally, the preparation was thought to diminish the presence of potentially combustible colonic gas. Most of the solutions contained polyethylene glycol, mannitol, or Fleet’s (Lynchburg, Virginia) Phospho-soda. Most recent articles have discussed which type and what duration of MBP is optimal, but not whether the bowel preparation itself is necessary.3 Other topics of interest have focused on the actual benefit of the oral antibiotic bases. However, the benefit of the preparation itself has been thought to be unquestionable. In this regard, the article by Memon et al seems like heresy. The methodology of this study is clearly flawed by its lack of randomization, but its results certainly alert the reader
CURRENT SURGERY
•
Volume 56 / Number 3 • March/April 1999
SOUMITRA R. EACHEMPATI, MD JOHN M. DALY, MD Department of Surgery Weill Medical College of Cornell University New York, New York
that the necessity of MBP may be questionable in elective colonic surgery. Primary anastomosis after resection in emergent left colonic surgery has also been thought to pose unjustifiable risks to the patient. Nonetheless, the management of left-sided colonic obstruction and perforation using this technique with intraoperative colonic lavage has been increasingly practiced in the United Kingdom in recent years. Certainly, this approach can only be used in select patients.4,5 The data by Biondo et al with this technique demonstrate that primary anastomosis after intraoperative lavage can occupy a rightful place in the armamentarium of the general surgeon. The technique itself can be properly performed without intraabdominal contamination, according to the excellent and concise description by the authors. Systemic antibiotics have been universally advocated as important adjunctive therapy in colonic surgery.6 Currently, the most important feature regarding the administration of antibiotics is that the tissue concentration be optimal at the time of bacterial contamination. Debates regarding the utility of the oral antibiotic base appear well founded and will make this topic prominent in the colorectal literature in the near future.
References 1. Wexner SD. Standardized perioperative care protocols and reduced lengths of stay after colon surgery. J Am Coll Surg 1998;186:589 – 593. 2. Davey PG, Nathwani D. What is the value of preventing postoperative infections? New Horizons 1998;6(suppl 2):S64 –S71. 3. Messick CR, Danziger LH. Therapeutic modalities for mechanical cleansing of the colon. J Am Pharm Ass 1996;NS36(7):439 – 442. 4. Sitzler PJ, Stephenson BR, Nicholls RJ. On-table colonic lavage: an alternative. J Royal Coll Surg Edinburgh 1998;43:276 –277. 5. Trillo C, Paris MF, Brennan JT. Primary anastomosis in the treatment of acute disease of the unprepared left colon. Am Surg 1998;64:821– 824; discussion 824 – 825. 6. Platell C, Hall J. What is the role of mechanical bowel preparation in patients undergoing colorectal surgery? Dis Col Rect 1998;41:875– 882; discussion 882– 883.
General
Repair of Incisional Hernias Guest Reviewer: Charles F. Cobb, MD GREATER RISK OF INCISIONAL HERNIA WITH MORBIDLY OBESE THAN STEROIDDEPENDENT PATIENTS AND LOW RECURRENCE WITH PREFASCIAL POLYPROPYLENE MESH.
Sugerman HJ, Kellum JM Jr, Reines D, et al. Am J Surg 1996;171:80 – 84. To compare the frequency of development of incisional hernia in patients undergoing gastric bypass for morbid obesity and in patients undergoing total abdominal colectomy for ulcerative colitis, and to evaluate the extrafascial placement of polypropylene mesh for incisional herniorrhaphy.
Objective
A review of patients undergoing surgery between October 1982 and November 1994.
Design
University Hospital, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia.
Setting
One hundred seventy-one patients underwent a total abdominal colectomy and ileal pouch–anal anastomosis for ulcerative colitis and 974 patients underwent gastric bypass for morbid obesity. An additional 98 patients had an extrafascial mesh repair of an incisional hernia.
Participants
A midline incision was used in all patients. This incision extended from the xiphoid to the umbilicus for patients undergoing gastric bypass and extended from midepigastrium to pubis for patients undergoing total abdominal colectomy and ileal pouch-anal anastomosis. In each case, the fascia was closed with a running No. 2 polyglycolic acid suture. This suture was spaced 1.5 cm from the edge of the fascia and 1.5 cm apart. For patients undergoing gastric bypass, the wound was closed by a postgraduate year 3 resident. For patients undergoing colectomy, the closure was
Methods
CURRENT SURGERY
•
Volume 56 / Number 3 • March/April 1999
105
Colon/Rectal
Infectious Complications in Colonic Surgery Guest Reviewers: Soumitra R. Eachempati, MD, and John M. Daly, MD INTRAOPERATIVE COLONIC LAVAGE AND PRIMARY ANASTOMOSIS IN PERITONITIS AND OBSTRUCTION.
Biondo S, Jaurrieta E, Jorba R, et al. Br J Surg 1997;84:222–225. To evaluate differences in outcome in patients with peritonitis or obstruction who require left colonic resection and undergo on-table lavage with primary anastomosis.
Objective
A retrospective review of all patients undergoing emergency operations for a distal colonic lesion from January 1992 to August 1995.
Design
A tertiary medical facility associated with the University of Barcelona, Spain.
Setting
Of 212 patients who underwent emergency colonic surgery for distal lesions requiring resection during the study period, 63 patients were selected for primary anastomosis after on-table lavage. In this technique, the left colon is generously mobilized laterally along its peritoneal borders up to and including the splenic flexure. The cecum is cannulated with a 24 Fr Foley catheter either through the appendix or the terminal ileum. The end of left colon is brought outside the abdominal cavity on its mesentery and a colotomy is made. After the distal end is placed in a plastic bag, normal saline at 37°C is used to irrigate the colon until clear. After colonic irrigation, the rectum is irrigated and the bowel anastomosed in an end-to-end fashion. The authors used stapling devices for anastomoses constructed below the peritoneal reflection. Parenteral antibiotic therapy with metronidazole and gentamicin (or ciprofloxacin if the patient had depressed renal function) was used perioperatively and continued postoperatively if the patient had peritonitis.
Methods
Thirty-two men and 31 women underwent colonic lavage with resection and primary anastomosis. Criteria precluding lavage with primary anastomosis included irresectable colonic lesion (31 patients), proximal colonic damage (31 patients), circulatory instability (29 patients), advanced peritonitis (21 patients), and poor general medical condition (18 patients). The mean age of the patients was 61 6 13 years. Thirty-seven patients had a colorectal tumor. Indications for surgery were obstruction in 37 patients, acute abdominal inflammation in 24, ischemic rectal prolapse in 2, and diverticular hemorrhage in 1. Complications occurred in 21 of the 63 patients treated by
Results
CURRENT SURGERY
•
© 1999 by the Association of Program Directors in Surgery Published by Elsevier Science Inc.
0149-7944/99/$20.00
101
primary anastomosis after colonic irrigation. Three perioperative deaths and three clinically significant anastomotic leaks occurred. The most common complications were wound infections (10 patients) and prolonged paralytic ileus (6 patients). Conclusions
With appropriate selection, certain patients with colonic obstruction and peritonitis may safely undergo a one-stage procedure consisting of antegrade colonic lavage, bowel resection, and immediate colonic anastomosis. REVIEWER COMMENTS. Emergent left colon surgery involving resection is almost always managed with diverting colostomy in the United States. These authors in the United Kingdom reviewed their experience with primary anastomosis after on-table lavage for emergent left colon surgery. Their excellent description of the technique of on-table lavage provides valuable knowledge for the surgeon or surgeon-in-training and should be used as an available reference. Their results demonstrate that primary anastomosis can be performed in left colon surgery with modest morbidity, as 21 of their 63 patients had a complication. These results may be acceptable because the patients required emergency operations and did not have to undergo the morbidity of a subsequent colostomy takedown. The importance of this article is that the reader will become aware that options to mandatory colostomy may exist in emergent left colonic surgery requiring resection. A DOUBLE-BLIND, RANDOMIZED STUDY OF 3 ANTIMICROBIAL REGIMENS IN THE PREVENTION OF INFECTIONS AFTER ELECTIVE COLORECTAL SURGERY.
Jewesson P, Chow A, Wai A, et al. Diagn Microbiol Infect Dis 1997;29:155–165.
102
Objective
To determine which of three antimicrobial regimens, either cefoxitin, ceftizoxime, or metronidazole with gentamicin was most effective at preventing infection in colorectal surgery.
Design
A randomized, double-blind, prospective clinical trial in a Canadian tertiary care teaching hospital from November 1990 to April 1993.
Setting
The study was conducted at Vancouver Hospital, a 1000-bed tertiary care hospital affiliated with the University of British Columbia.
Participants
Patients older than 19 years, excluding actively lactating or pregnant women, scheduled for an elective colorectal procedure who had none of the following other exclusion criteria were eligible: clinical or microbiologic evidence of infection within 48 hours of surgery, an antibacterial agent administered within 7 days of surgery, evidence of complete bowel obstruction, or a history of a hypersensitivity reaction to the study drugs.
Methods
A computerized random number generator was used to randomize each patient into one of three study drug regimens: (1) 1000 mg of ceftizoxine; (2) 1000 mg of cefoxitin; (3) 500 mg of metronidazole plus 120 mg of gentamicin. The drugs were administered within 15–30 minutes of the onset of surgery, and at 12 and 24 hours postoperatively. An additional 8 doses of study drugs were given at 12-hour intervals to patients deemed at high risk for infection (ie, bowel ischemia, perforation, HIV seropositivity, cirrhosis, current steroid usage, and diabetes mellitus). All patients received mechanical bowel preparation by mouth after a minimum 3– 4 hour fast on the day before surgery. Surgical wounds were classified as class I–IV, with I being no infection and IV being a widespread infection requiring systemic antibiotics. A previously described “ASEPSIS” scoring system was used to grade surgical wound sites before discharge. Data were prospectively collected and retrospectively analyzed in a blinded fashion.
Results
During the 30-month study, 153 patients were enrolled, of which 122 (38 ceftizoxime, 45 metronidazole-gentamicin, and 39 cefoxitin) completed the study. No demographic differences among the 3 groups were noted in terms of sex, age, weight, colorectal characteristics, or comorbidities. Superficial wound infections occurred in 5 cefoxitin patients and 1 metronidazole-gentamicin patient. Deep subcutaneous wound infections were seen in 6 metronidazole-gentamicin patients and 4 cefoxitin patients. One widespread infection (class IV) was seen in a cefoxitin patient. Overall mean ASEPSIS scores for the cefoxitin (mean 9.2) and metronidazole-gentamicin (mean 10.4) groups were higher (p 5 0.01) than those for the ceftizoxime group (mean 2.3).
Conclusions
These data suggest that ceftizoxime is superior to cefoxitin and metronidazole-gentamicin in the prevention of colorectal surgical wound infections. CURRENT SURGERY
•
Volume 56 / Number 3 • March/April 1999
REVIEWER COMMENTS. Wound infections are a costly morbidity for elective colon surgery. The study demonstrates that different therapies may not prevent wound infections equally. This well-designed study concluded that ceftizoxime was the best agent of those studied for the prevention of the complication of wound infection. Because so many different therapies can be used for this surgery, a study proving which antibiotic therapy is the best is nearly impossible to perform. Nevertheless, the study provides valuable information in that it examines the results of several common therapies. Perhaps most importantly, in detailing the method of determining an ASEPSIS score, the study provides a model for future studies in the analysis of wound morbidity in colon surgery. Interestingly, the authors gave their high-risk patients 10 postoperative doses. This approach has been questioned recently and provides the question for a subsequent study. IS MECHANICAL BOWEL PREPARATION REALLY NECESSARY FOR ELECTIVE LEFT-SIDED COLON AND RECTAL SURGERY?
Memon MA, Devine J, Freeney J, From SG. Int J Colorect Dis 1997;12:298 –302. To determine whether mechanical bowel preparation is necessary for elective left-sided colon and rectal surgery.
Objective
A review of infectious and perioperative complications of patients with and without mechanical bowel preparation who underwent left-sided colorectal surgery at a single hospital between January 1, 1992, and December 31, 1994.
Design
A single teaching hospital, Whiston Hospital, in Merseyside, United Kingdom.
Setting
One hundred thirty-six patients undergoing elective left-sided colon surgery by 1 of 5 surgeons, varying from consultant to senior house officer.
Participants
Patients who underwent left-sided colon surgery within the study period were nonrandomly assigned to undergo surgery with or without mechanical bowel preparation depending on whether the operating surgeon was in the group of surgeons who routinely omitted the use of the mechanical bowel preparation (MBP) for elective colonic surgery. The majority of patients (93.4%) received single-dose intravenous antibiotics at the time of induction of anesthesia.
Methods
Sixty-one patients received preoperative mechanical bowel preparation for elective left-sided colonic surgery and 75 patients underwent operations without any mechanical preparation. The patients in each group were similar in age (61.2 vs 64.7), sex, and disease pattern. One hundred twenty-four patients had drains placed in the peritoneal cavity or perineum, the majority of which were of the closed-suction variety. The mean interval after the operation when the drains were removed was not significantly different in either group. The average hospital stay was 13.2 days in the MBP group vs 15.2 in the non-MBP group (p 5 0.3560). The incidences of wound infections (6.6% in MBP vs 13.3% in the non-MBP group), wound dehiscences (3.3% in the MBP vs 5.3% in the non-MBP group), abdominal or pelvic collections (4.9% in the MBP group vs 2.7% in the non-MBP group), and anastomotic breakdowns (8.2% in the MBP group vs 2.7% in the non-MBP group) were not significantly different between the two groups. Two patients died, both of whom had received MBP. One of these deaths was related to an anastomotic dehiscence.
Results
Mechanical bowel preparation may confer no discernible advantage in decreasing infectious and perioperative mortality in patients undergoing elective left colon and rectal surgery.
Conclusions
REVIEWER COMMENTS. Mechanical bowel preparation in some fashion has become a routine for elective colonic surgery. These authors question its utility for this indication based on a retrospective, nonrandomized analysis. Unfortunately, the study cannot demonstrate a difference between outcomes in patients treated with or without MBP. They suggest that their results hinge on the skills of the individual surgeons involved and not the use of MBP. This study is important because it questions the rationale of a therapy associated with some cost and morbidity, and its results may provide a springboard for a prospective, randomized, multicenter trial to answer whether MBP is necessary in elective colonic surgery. ANTIMICROBIAL PROPHYLAXIS IN COLORECTAL SURGERY: A SYSTEMATIC REVIEW OF RANDOMIZED CONTROLLED TRIALS.
Song F, Glenny AM. Br J Surg 1998;85:1232–1241. CURRENT SURGERY
•
Volume 56 / Number 3 • March/April 1999
103
Objective
To determine the relative efficacy of antimicrobial prophylaxis for the prevention of postoperative wound infection in patients undergoing colorectal surgery.
Design
This study is a review of previously published studies analyzing different antimicrobial regimens in preventing wound infections in colorectal surgery.
Setting
The current authors from the University of York reviewed work mainly from teaching hospitals.
Participants
Patients undergoing elective colorectal surgery at the respective hospitals of the authors.
Methods
The authors reviewed randomized controlled trials between 1984 and 1995 by searching MEDLINE, EMBASE, and the Cochrane Trials Register with the assistance of the NHS Center for Reviews and Dissemination of York, United Kingdom. The rate of surgical wound infection was used as the principal outcome measure. Attempts were made to include only abdominal wound infections. When several trials used the same groups of antibiotics, a formal metaanalysis was performed. This paper presented the results of trials evaluating a regimen containing cefuroxime plus metronidazole or a regimen containing gentamicin plus metronidazole. A special focus here also included the analysis of the newer generation of cephalosporins, certain combinations of antibiotics, and the relative efficacy of single versus multiple doses of antibiotic therapy.
Results
One hundred forty-seven trials were analyzed. Generally, more multicenter and more large trials were conducted recently. In the 4 trials using no antibiotics as a control group, the wound infection rate was much higher in the control group (40 % in the control group vs 13% in the treated group). Cefuroxime plus metronidazole was more effective than metronidazole alone and equal to other single agent regimens such as imipenem, cefotetan, and cefoxitin. Intravenous gentamicin and metronidazole was superior to oral erythromycin and neomycin. The difference in infection between a first- and second- or third-generation cephalosporin was not significant. In pooling 17 trials, no advantage was seen in giving multiple antibiotic doses over single doses.
Conclusions
Antimicrobial prophylaxis decreases surgical wound infection in colorectal surgery. Single-dose regimens may be equal to multiple-dose regimens in achieving this goal. The optimal prophylaxis contains antibiotic activity against both aerobic and anaerobic bacteria. REVIEWER COMMENTS. The benefit of antibiotics in many types of surgeries is being analyzed. Through an ambitious review, the authors demonstrated somewhat conclusively that antibiotics are beneficial in colonic surgery. They also showed that a single dose of antibiotics was probably equivalent to multiple-dose therapy. They did not provide any cost analysis, but the implication of substantial savings obviously exists for single-agent therapy. The authors would have liked to show which regimen was optimal for the prophylaxis of wound infections in colonic surgery. However, in most of their analyzed studies, the antibiotic regimens differed. Therefore, the study failed to capture definitively which particular therapy provided the best prophylaxis. An important conclusion of the study that merits further validation was that first-generation cephalosporins may be equivalent in efficacy to the later generation agents. Last, the authors reinforce an important point: The best results for antibiotic prophylaxis occur when the tissue concentration of the agent is sufficiently high when bacterial contamination occurs.
SUMMARY Different types of colonic surgery vary greatly in their propensity for infectious complications.1,2 Elective resections with prepared bowel have more clearly associated morbidity than emergent colonic resections with unprepared bowel. Traditionally, complications have been thought to be minimized by the avoidance of primary anastomosis in emergent and unprepared colonic cases. Each article reviewed addresses different questions in the spectrum of possible colonic operations. Two of the articles review important factors regarding antibiotic use in elective surgery, and the other two challenge some staunchly held beliefs related to colon surgery. Since the 1970’s, mechanical bowel preparation (MBP) has been a widely practiced feature of elective colonic surgery.
104
The standard preparation has included a large volume of orally ingested cathartic with multiple doses of antibiotic base. These preparations were thought to decrease infectious complications by decreasing fecal loading through the cathartic effect and with the bases also minimize intraluminal bacterial counts. Additionally, the preparation was thought to diminish the presence of potentially combustible colonic gas. Most of the solutions contained polyethylene glycol, mannitol, or Fleet’s (Lynchburg, Virginia) Phospho-soda. Most recent articles have discussed which type and what duration of MBP is optimal, but not whether the bowel preparation itself is necessary.3 Other topics of interest have focused on the actual benefit of the oral antibiotic bases. However, the benefit of the preparation itself has been thought to be unquestionable. In this regard, the article by Memon et al seems like heresy. The methodology of this study is clearly flawed by its lack of randomization, but its results certainly alert the reader
CURRENT SURGERY
•
Volume 56 / Number 3 • March/April 1999
SOUMITRA R. EACHEMPATI, MD JOHN M. DALY, MD Department of Surgery Weill Medical College of Cornell University New York, New York
that the necessity of MBP may be questionable in elective colonic surgery. Primary anastomosis after resection in emergent left colonic surgery has also been thought to pose unjustifiable risks to the patient. Nonetheless, the management of left-sided colonic obstruction and perforation using this technique with intraoperative colonic lavage has been increasingly practiced in the United Kingdom in recent years. Certainly, this approach can only be used in select patients.4,5 The data by Biondo et al with this technique demonstrate that primary anastomosis after intraoperative lavage can occupy a rightful place in the armamentarium of the general surgeon. The technique itself can be properly performed without intraabdominal contamination, according to the excellent and concise description by the authors. Systemic antibiotics have been universally advocated as important adjunctive therapy in colonic surgery.6 Currently, the most important feature regarding the administration of antibiotics is that the tissue concentration be optimal at the time of bacterial contamination. Debates regarding the utility of the oral antibiotic base appear well founded and will make this topic prominent in the colorectal literature in the near future.
References 1. Wexner SD. Standardized perioperative care protocols and reduced lengths of stay after colon surgery. J Am Coll Surg 1998;186:589 – 593. 2. Davey PG, Nathwani D. What is the value of preventing postoperative infections? New Horizons 1998;6(suppl 2):S64 –S71. 3. Messick CR, Danziger LH. Therapeutic modalities for mechanical cleansing of the colon. J Am Pharm Ass 1996;NS36(7):439 – 442. 4. Sitzler PJ, Stephenson BR, Nicholls RJ. On-table colonic lavage: an alternative. J Royal Coll Surg Edinburgh 1998;43:276 –277. 5. Trillo C, Paris MF, Brennan JT. Primary anastomosis in the treatment of acute disease of the unprepared left colon. Am Surg 1998;64:821– 824; discussion 824 – 825. 6. Platell C, Hall J. What is the role of mechanical bowel preparation in patients undergoing colorectal surgery? Dis Col Rect 1998;41:875– 882; discussion 882– 883.
General
Repair of Incisional Hernias Guest Reviewer: Charles F. Cobb, MD GREATER RISK OF INCISIONAL HERNIA WITH MORBIDLY OBESE THAN STEROIDDEPENDENT PATIENTS AND LOW RECURRENCE WITH PREFASCIAL POLYPROPYLENE MESH.
Sugerman HJ, Kellum JM Jr, Reines D, et al. Am J Surg 1996;171:80 – 84. To compare the frequency of development of incisional hernia in patients undergoing gastric bypass for morbid obesity and in patients undergoing total abdominal colectomy for ulcerative colitis, and to evaluate the extrafascial placement of polypropylene mesh for incisional herniorrhaphy.
Objective
A review of patients undergoing surgery between October 1982 and November 1994.
Design
University Hospital, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia.
Setting
One hundred seventy-one patients underwent a total abdominal colectomy and ileal pouch–anal anastomosis for ulcerative colitis and 974 patients underwent gastric bypass for morbid obesity. An additional 98 patients had an extrafascial mesh repair of an incisional hernia.
Participants
A midline incision was used in all patients. This incision extended from the xiphoid to the umbilicus for patients undergoing gastric bypass and extended from midepigastrium to pubis for patients undergoing total abdominal colectomy and ileal pouch-anal anastomosis. In each case, the fascia was closed with a running No. 2 polyglycolic acid suture. This suture was spaced 1.5 cm from the edge of the fascia and 1.5 cm apart. For patients undergoing gastric bypass, the wound was closed by a postgraduate year 3 resident. For patients undergoing colectomy, the closure was
Methods
CURRENT SURGERY
•
Volume 56 / Number 3 • March/April 1999
105