Single-layer anastomosis of the colon. A review of 165 cases

Influence of suture technique on anastomotic leakage rate-a retrospective analyses comparing interrupted-versus continuous-sutures

PURPOSE

While many hospitals consider a continuous sutured colonic anastomosis with monofilamental fiber the current state of the art, others have advocated for interrupted sutures as the gold standard. The aim of the study was to evaluate the influence of suture technique on leakage rate (primary endpoint), wound infections, postoperative stay, and mortality.

METHODS

Retrospective analyses of 347 patients (273 elective, 74 urgent) over 6 years with a handsewn colonic anastomosis (190 interrupted, 157 continuous), excluding sigma and rectum anastomosis. Demographic and surgical baseline characteristics were used as competing predictors.

RESULTS

Overall leakage rate was 9% but strongly dependent on suture technique (interrupted: 16%; continuous: 2.5%; p = 0.001) yielding an odds ratio of 5.10 [95% CI: 2.55, 6.71] (relative risk of leakage). No other variable showed a significant influence on leakage rate. Postoperative stay was prolonged in the interrupted suture group (23 ± 15 vs. 16 ± 11 days; p = 0.000, attributable effect 7.5 days [4.7, 10.3]).

CONCLUSIONS

Our results indicate a highly significant reduction of anastomotic leakage rate and postoperative stay that generalize to the underlying population by continuous sutures in handsewn colonic anastomosis. In the absence of randomized prospective studies, the current results provide the yet strongest evidence for the superiority of continuous sutures.

Experimental study of the efficacy of the endoluminal prosthesis in colonic anastomoses

Colorectal surgery is still associated with a significant morbidity and mortality rate, mostly related to suture failure. We have carried out a randomized experimental study in dogs on colonic anastomoses exposed to a number of anastomotic risk situations. A total of 42 dogs was used. They were divided into three study groups (control, occlusion and diverticulitis), with and without an endoluminal tube. The aim was to assess the efficacy of the endoluminal prosthesis using clinical and radiological assessment of anastomotic healing. Pre- and post-anastomotic intraluminal pressures were also measured to determine whether these might be a factor in suture failure. There were significant differences in suture failure in animals in which the endoluminal tube was used. Mean duration of placement was 10.5 days. In the colon healing study, no significant differences were found between the groups in the pathological examination or in the assay of hydroxyproline content. The presence of the endoluminal tube may increase the maximum pressure applied on the colon wall. No significant differences were found in the intracolonic pressure differentials between the different groups or after the inclusion of the endoluminal prosthesis. The results obtained establish the efficacy of the endoluminal prosthesis in protecting the colonic anastomosis, and could be a valuable technique in colonic anastomoses with a high risk of suture dehiscence.

Sutureless bowel anastomosis using Nd:YAG laser

Small bowel anastomoses were performed without sutures by using the Nd:YAG laser to produce welded enterotomies. Optimal energy levels for contact and noncontact laser were determined. Anastomoses produced using five target energy levels between 100 and 500 J were examined. Short-term anastomotic strength of these enterotomies was measured 1 min after the welding. Bursting pressure of the laser welded enterotomies was compared to the bursting pressure of traditional two-layer, inverting, interrupted sutured bowel anastomoses. The overall mean bursting pressure of non-contact-welded enterotomies was 50.6 mmHg. Optimal laser settings determined in this initial phase were then used to produce anastomoses in rabbits which are recovered postoperatively for 1 or 2 weeks in order to examine long-term viability and integrity of the anastomoses. All chronic rabbit preparations recovered without complication. The mean bursting pressure was 200 mmHg, not significantly different from that of uncut bowel or two-layer sutured anastomosis.

Collagen dynamics of partial small bowel obstruction

The response of intestinal collagen to obstruction and stress was studied in the rat. Partial small bowel obstructions were created. Preobstruction collagen was measured by injection of tritium labeled proline. New collagen formation after obstruction occurred was followed by injection of carbon-14 labeled proline. At 3 weeks, collagen fractions were identified. Throughout the study, preexisting preobstruction intestinal collagen was metabolically stable with no breakdown or remodeling demonstrable. New collagen formation was rapid and occurred to the largest degree close to the obstruction.

Collagen formation during the healing of colonic anastomoses

To study new collagen formation in the healing of anastomoses in the right colon, five male Sprague-Dawley rats had single-layer colonic anastomosis performed. Five additional rats had suture of the colon with interrupted sutures without transection of the colon. Ten animals served as controls. One week after surgery, animals were given 3H-proline repeatedly to label new collagen formation during the second and third weeks. Animals were sacrificed three weeks after suturing or anastomosis. Two- or 10-mm segments were precisely excised on either side of the suturing or anastomoses. Total collagen and its total radioactivity were measured per segment. Collagen hydroxyproline and its radioactivity increased (100 per cent) only within 1 cm of the anastomosis or suture alone. No local or distant decrease in collagen was observed. Collagen formation in colonic wounds appears to be a local process.

[Anterior resection and abdomino-perineal extirpation in patients with rectal cancer: a retrospective analysis (author's transl)]

Eighty-seven patients with an abdomino-perineal extirpation of the rectum and 75 patients with an anterior resection of the rectum could be analysed retrospectively. The mean observation period was 36 months for anterior resection and 38 months for abdomino-perineal extirpation. The rate of recurrences, mortality, and postoperative complications of each surgical method was correlated to tumor-localization, -staging, and -grading. The poor prognosis of patients with abdomino-perineal extirpation was mainly due to relatively more cases in advanced tumor stage. In rectal cancer above 7 cm anterior resection should be performed.

Anastomotic integrity after operations for large-bowel cancer: a multicentre study

Clinically evident anastomotic dehiscence was studied in 1466 patients who had undergone resection of a large-bowel adenocarcinoma. The overall incidence of anastomotic leakage was 13%, but the incidence varied between surgeons (range 0.5% to over 30%). Morbidity and mortality were significantly higher in those patients in whom the anastomosis failed to heal primarily. If these results are extrapolated to the national level, it should be possible by achieving results closer to those in patients without leakage to reduce overall post-operative mortality after resection of large-bowel cancer by 2% and to achieve an appreciable reduction in morbidity. Both factors are clinically important and, taken together, could result in appreciable saving of revenue.