Effect of fecal loading with/without peritonitis on the healing of a colonic anastomosis: an experimental study

Primary resection anastomosis versus Hartmann's procedure in Hinchey III and IV diverticulitis

Introduction

Surgical management of Hinchey III and IV diverticulitis utilizes either Hartmann’s procedure (HP) or primary resection anastomosis (PRA) with or without fecal diversion. The aim of this meta-analysis is to determine which of the two procedures has a more favorable outcome.

Methods

A systematic review of the existing literature was performed using the PRISMA guidelines. A meta-analysis was carried out using a Mantel-Haenszel, random effects model, and forest plots were generated. The Newcastle-Ottawa and Jadad scoring tools were used to assess the included studies.

Results

A total of 25 studies involving 3546 patients were included in this study. The overall mortality in the HP group was 10.8% across the observational studies and 9.4% in the randomized controlled trials (RCTs). The mortality rate in the PRA group was lower than that in the HP group, at 8.2% in the observational studies and 4.3% in the RCTs. A comparison of PRA vs HP demonstrated a 40% lower mortality rate in the PRA group than in the HP (OR 0.60, 95% CI 0.38–0.95, p = 0.03) when analyzing the observational studies. However, meta-analysis of the three RCTs did not demonstrate any difference in mortality, (OR 0.44 (95% CI 0.14–1.34, p = 0.15). Wound infection rates between the two groups were comparable (OR 0.75, 95% CI 0.20–2.78, p = 0.67).

Conclusion

Analysis of observational studies suggests that PRA may be associated with a lower overall mortality. There were no differences in wound infection rates. Based on the current evidence, both surgical strategies appear to be acceptable.

Mechanical bowel preparation with different solutions in rats with selective left colonic ischemia and reperfusion injury

BACKGROUND

The aim of this study was to evaluate the effects of preoperative mechanical bowel preparation (MBP) on colonic ischemia/reperfusion (I/R) injury.

METHODS

Seventy adult male Sprague-Dawley rats were divided randomly into 7 equal groups of 10 rats each. Groups were assigned as follows: group I = sham surgery; group II = I/R of left colon (control group); group III = intravenous heparin and metronidazole followed by I/R of the left colon; groups IV through VII = before I/R of the left colon, heparin and metronidazole and MBP were performed with sodium chloride (NaCl), Na phosphate, polyethylene glycol, and mannitol, respectively. Histopathologic and biochemical parameters were evaluated.

RESULTS

According to the histopathologic changes, the groups least affected by I/R injury were groups V and VII. Catalase activity was significantly higher in groups V and VII, and copper-zinc superoxide dismutase activity was significantly higher in group VII compared with the control group (P <.002).

CONCLUSIONS

MBP with sodium phosphate and mannitol appears to be more protective against I/R injury.

Emergency left colon resection for acute perforation: primary anastomosis or Hartmann's procedure? A case-matched control study

BACKGROUND

The optimal treatment remains controversial for acute left-sided colon perforation. Therefore, the effectiveness and safety of primary anastomosis versus Hartmann's operation (HP) was compared in a case-matched control study.

METHODS

Thirty consecutive patients with primary anastomosis and protective ileostomy (PAS) were matched to 30 HP patients, controlling for age, gender, American Society of Anesthesiologists (ASA) score, body mass index (BMI), and peritonitis severity (Hinchey). In a second analysis, PAS patients with purulent peritonitis (Hinchey 3) were matched to patients with primary anastomosis without ileostomy (PA).

RESULTS

Hospital mortality was similar between HP (17%) and PAS (10%). Complication frequency and severity (requiring re-intervention or admission to the Intensive Care Unit [ICU]) were comparable for the first operation (60% versus 56% and 30% versus 32%). The stoma reversal rate was higher in PAS than in HP (96% versus 60%, p = 0.001), with significantly fewer complications (23% versus 66%, p = 0.02), and lower severity (7% versus 33%, p = 0.02). Additional analysis of PAS versus PA showed similar morbidity (52% versus 41%, p = 0.45) and complication severity (18% versus 24%, p = 0.51), whereas overall operation time and hospital stay were significantly shorter in PA (169 versus 320 min, p = 0.003, 17 versus 28 days, p < 0.001).

CONCLUSIONS

Primary anastomosis and protective ileostomy is a superior treatment to HP in acute left-sided colon perforation. In the absence of feculent peritonitis an ileostomy appears unnecessary.

Multicentre randomized clinical trial of mechanical bowel preparation in elective colonic resection

Background

Recent studies have suggested that MBP does not lower the risk of postoperative septic complications after elective colorectal surgery. This randomized clinical trial assessed whether preoperative MBP is beneficial in elective colonic surgery.

Methods

A total of 1505 patients, aged 18–85 years with American Society of Anesthesiologists grades I–III, were randomized to MBP or no MBP before open elective surgery for cancer, adenoma or diverticular disease of the colon. Primary endpoints were cardiovascular, general infectious and surgical-site complications within 30 days, and secondary endpoints were death and reoperations within 30 days.

Results

A total of 1343 patients were evaluated, 686 randomized to MBP and 657 to no MBP. There were no significant differences in overall complications between the two groups: cardiovascular complications occurred in 5·1 and 4·6 per cent respectively, general infectious complications in 7·9 and 6·8 per cent, and surgical-site complications in 15·1 and 16·1 per cent. At least one complication was recorded in 24·5 per cent of patients who had MBP and 23·7 per cent who did not.

Conclusion

MBP does not lower the complication rate and can be omitted before elective colonic resection. Registration number: ISRCTN28535118 (http://www.controlled-trials.com).

Surgical decision-making: integrating evidence, inference, and experience

Evidence-based medicine provides a well-developed framework for evaluation of clinical research. Well-designed and adequately powered randomized controlled trials provide the best information on therapeutic efficacy; however, extrapolation of the trials' conclusions to individual patients may be difficult, and for many important surgical problems, trial data are unavailable. A complementary approach of inferential decision-making helps address these limitations, and increases the clinician's confidence in the safety of an approach of unknown efficacy. Experience establishes norms and expectations, and emphasizes events that are uncommon but clinically important. Although it cannot eliminate uncertainty or controversy, the integration of analytic techniques of evidence, inference, and experience provides the surgeon with the best means of adapting treatment to the unique circumstances of the individual patient.

Primary anastomosis or Hartmann's procedure for patients with diverticular peritonitis? A systematic review

PURPOSE

This systematic literature review was designed to summarize and compare the reported outcomes of one-stage and two-stage operations for the treatment of perforated diverticulitis with peritonitis.

METHODS

This review identified 98 published studies (1957-2003) dealing with the surgical management of perforated diverticulitis with peritonitis, either with primary resection and anastomosis or with the Hartmann's procedure. Aggregated results of adverse outcomes were calculated but statistical comparisons were not appropriate because of data and design heterogeneity.

RESULTS

Operative mortality data from patients with diverticular peritonitis undergoing Hartmann's procedure (n = 1,051) were derived from 54 studies. Considering the Hartmann's procedure and its reversal procedures together, the mortality rate was 19.6 percent (18.8 percent for the Hartmann's procedure and 0.8 percent for its reversal), the wound infection rate was 29.1 percent (24.2 percent for the Hartmann's procedure and 4.9 percent for its reversal), and stoma complications and anastomotic leaks (in the reversal operation) occurred in 10.3 and 4.3 percent, respectively. Of 569 reported cases of primary anastomosis from 50 studies, the aggregated mortality rate was 9.9 (range, 0-75) percent with an anastomotic leak rate of 13.9 (range, 0-60) percent and a wound infection rate of 9.6 (range, 0-26) percent.

CONCLUSIONS

Reported mortality and morbidity in patients with diverticular peritonitis who underwent primary anastomosis were not higher than those in patients undergoing Hartmann's procedure were. This suggests that primary anastomosis is a safe operative alternative in certain patients with peritonitis. Despite inclusion of only patients with peritonitis in this analysis, selection bias may have been a limitation and a prospective, randomized trial is recommended.

Complications after colorectal surgery without mechanical bowel preparation

BACKGROUND

The current practice of mechanical bowel preparation (MBP) before colorectal surgery is questionable. Mechanical bowel preparation is unpleasant for the patient, often distressful, and potentially harmful. The results are often less than desired, increasing the risk of contamination. Cleansing the colon and rectum before surgery has never been shown in clinical trials to benefit patients. In animal experiments MBP has a detrimental effect on colonic healing.

STUDY DESIGN

To investigate the outcomes of colorectal surgery without MBP, we prospectively evaluated a consecutive series of patients who underwent resection and primary anastomosis of the colon and upper rectum, including emergency operations. One surgeon performed all operations. Endpoints were wound infection, anastomotic failure, and death. Late signs and symptoms that might be secondary to leakage of the anastomosis were considered as an anastomotic failure as well, during a followup of 1 year.

RESULTS

Two hundred fifty operations were performed, of which 199 (79.6%) were elective. Colectomies were left-sided in 65.6%. Anastomoses were ileocolic in 32%, colocolic in 20.8%, colorectal intraperitoneal in 34.4%, and extraperitoneal in 12.8%. No patient suffered from fecal impaction. Followup was complete in 97.2%. Eight patients (3.3%; 95% confidence interval [CI]: 1.4-6.4) developed superficial wound infections. In three patients there was leakage from an extraperitoneal colorectal anastomosis, in two of them after hospital discharge. The overall anastomotic failure rate was 1.2% (95% CI: 0.3-3.6). The in-hospital mortality rate was 0.8% (95% CI: 0.1-2.9) and was not related to abdominal or septic complications.

CONCLUSION

Mechanical bowel preparation is not a sine qua non for safe colorectal surgery.

Mechanical bowel preparation for elective colorectal surgery. A prospective, randomized, surgeon-blinded trial comparing sodium phosphate and polyethylene glycol-based oral lavage solutions

AIM

The aim of this study was to compare the cleansing ability, patient compliance, and safety of two oral solutions for elective colorectal surgery.

METHODS

All eligible patients were prospectively randomized to receive either 4 l of standard polyethylene glycol (PEG) solution or 90 ml of sodium phosphate (NaP) as mechanical bowel preparation for colorectal surgery. A detailed questionnaire was used to assess patient compliance. In addition, the surgeons, blinded to the preparation, intraoperatively evaluated its quality. Postoperative septic complications were also assessed. The calcium serum level was monitored before and after bowel preparation. Statistical analysis was performed using the Wilcoxon's rank-sum test and Fisher's exact test.

RESULTS

Two hundred patients, well matched for age, gender, and diagnosis, were prospectively randomized to receive either PEG or NaP solutions for elective colorectal surgery. All patients completed all phases of the trial. There was a significant decrease in serum calcium levels after administration of both NaP (mean, 9.3-8.8 mg/dl) and PEG (9.2-8.9 mg/dl), respectively (P < 0.0001), with no clinical sequelae. However, patient tolerance to NaP was superior to PEG: less trouble drinking the preparation (17 vs. 32 percent; P < 0.0002), less abdominal pain (12 vs. 22 percent; P = 0.004), less bloating (7 vs. 28 percent), and less fatigue (8 vs. 17 percent), respectively. Additionally, 65 percent of patients who received the NaP preparation stated they would repeat this preparation again compared with only 25 percent for the PEG group (P < 0.0001). Ninety-five percent of patients who received the NaP solution tolerated 100 percent of the solution compared with only 37 percent of the PEG group (P < 0.0001). For quality of cleansing, surgeons scored NaP as "excellent" or "good" in 87 compared with 76 percent after PEG (P = not significant). Rates of septic and anastomotic complications were 1 percent and 1 percent for NaP and 4 percent and 1 percent for PEG, respectively (P = not significant).

CONCLUSION

Both oral solutions proved to be equally effective and safe. However, patient tolerance of the small volume of NaP demonstrated a clear advantage over the traditional PEG solution.

Intra-abdominal sepsis impairs colonic reparative collagen synthesis

BACKGROUND

Intra-abdominal infection is generally considered a contraindication to primary colon anastomosis. In order to elucidate the mechanisms by which sepsis affects colonic healing, we studied anastomotic new collagen and protein synthesis and collagen gene expression in a relevant animal model.

METHODS

Forty male Sprague-Dawley rats (240 to 260 g) underwent sham laparotomy (SHAM, n = 18) or cecal ligation and single puncture (CLP, n = 22). After 24 hours, animals underwent single-layer left colon anastomosis. Animals were sacrificed either 1 or 4 days postanastomosis. Anastomotic segments of colon were excised, minced, and incubated with 4.5 muCi 3H-proline. After 3 hours, tissue 3H-proline incorporation was quantitated as an index of total new protein synthesis. The protein fraction was then digested with purified collagenase enzyme to determine 3H-proline incorporation into collagenase-digestible protein, an index of new collagen synthesis. Total RNA was extracted from anastomotic tissue samples and subjected to Northern blot analysis for type I and type III collagen genes.

RESULTS

Intra-abdominal sepsis resulted in markedly less new collagen synthesis 1 day postanastomosis (9,163 +/- 1,234 versus 3,744 +/- 444 disintegrates per minute 3H-proline/mg of protein, P < 0.0001) and 4 days postanastomosis (8,462 +/- 956 versus 5,708 +/- 802 dpm/mg of protein P < 0.05). Noncollagenous protein synthesis was also impaired in anastomotic tissue from CLP rats on postanastomosis day 1 (37,497 +/- 3,740 versus 18,593 +/- 2,695 dpm/mg of of protein, P < 0.001) and postanastomosis day 4 (28,238 +/- 834 versus 17,784 +/- 1,415 dpm/mg of of protein, P < 0.0001). The expression of type I and type III collagen was altered relative to the normal temporal sequence observed in SHAM animals.

CONCLUSION

Intra-abdominal infection impairs colonic reparative collagen and protein synthesis. In addition, regulation of type I and type III collagen genes is altered by intra-abdominal sepsis, and the alteration likely contributes to impaired new collagen synthesis and decreased colonic mechanical strength.

Extraperitoneal manifestation of perforated diverticulitis

We observed five cases of unusual extraperitoneal presentation of diverticulitis during an 11 year period. During that time, a total of 263 patients were operated for diverticulitis. Patients 1-4 presented with an inflammatory spread of diverticulitis through the abdominal wall; in patient 5 multiple abscesses were present in the left thigh. Inadequate resection and previous radiotherapy in patient 4 might have contributed to the complicated course. In patient 5, poor condition initially allowed only local drainage of the thigh abscesses. Despite laparotomy and sigmoid resection a few days after drainage, the fatal outcome could not be prevented. A more extensive resection and a protecting colostomy might have prevented the fistulous complication in patient 4. A primary resection and abscess drainage might have averted the fatal outcome in patient 5.