Anastomosis to the rectum. Operative experience

Bowel anastomoses: The theory, the practice and the evidence base

Since the introduction of stapling instruments in the 1970s various studies have compared the results of sutured and stapled bowel anastomoses. A literature search was performed from 1960 to 2010 and articles relating to small bowel, colonic and colorectal anastomotic techniques were reviewed. References from these articles were also reviewed, and relevant articles obtained. Either a stapled or sutured gastrointestinal tract anastomosis is acceptable in most situations. The available evidence suggests that in the following situations, however, particular anastomotic techniques may result in fewer complications: A stapled side-to-side ileocolic anastomosis is preferable following a right hemicolectomy for cancer. A stapled side-to-side anastomosis is likely also preferable after an ileocolic resection for Crohn’s disease. Colorectal anastomoses can be sutured or stapled with similar results, although the incidence of strictures is higher following stapled anastomoses. Following reversal of loop ileostomy there is some evidence to suggest that a stapled side-to-side anastomosis or sutured enterotomy closure (rather than spout resection and sutured anastomosis) results in fewer complications. Non-randomised data has indicated that small bowel anastomoses are best sutured in the trauma patient. This article reviews the theory, practice and evidence base behind the various gastrointestinal anastomoses to help the practising general surgeon make evidence based operative decisions.

Colorectal stapled anastomoses. Experiences and results

PURPOSE

Stapled anastomoses are currently an established technique in colorectal surgery. Larger series about the use of circular staplers in rectal anastomoses within daily clinical routine are rare.

METHODS

We evaluated the morbidity, clinical leakage rate, and mortality in an unselected population of a teaching hospital after elective, left-sided colorectal resections with stapled rectal anastomoses. In the course of our study, manually sewn rectal anastomoses were not performed. All anastomoses were tested intraoperatively by instillation of liquid.

RESULTS

A total of 615 elective colorectal resections with stapled rectal anastomoses was performed by 18 surgeons from 1984 to 1993. A protective colostomy was created in 2.9 percent (n=16) of all patients. Clinical anastomotic leakage occurred in nine patients (1.5 percent). The mortality rate was 1 percent (n=6).

CONCLUSION

Use of the stapling technique facilitates the performance of anastomoses, particularly in regions with difficult anatomy. The rate of local complications is low, and protective colostomy can thus be dispensed with in most cases

Blood flow in colon anastomotic stricture formation

PURPOSE

The influence of both blood flow and anastomotic technique on the development of anastomotic stricture formation was studied using a dog model.

METHODS

Fifty-three dogs underwent distal colocolonic anastomosis with either an EEA (U.S. Surgical Corp., Norwalk, CT) circular stapler or a Czerny-Lembert two-layered, handsewn anastomosis. Blood flow was measured by Laser Doppler Velocimetry using the Laserflo BPM2 (Vasamedics Inc., St. Paul, MN). The animals were separated into three blood flow groups: greater than or equal to 62.5 percent of normal blood flow, between 37.5 percent and 62.5 percent of normal blood flow, and less than or equal to 37.5 percent of normal blood flow. Each blood flow group had an anastomosis performed by either stapling or by hand sewing techniques. At six weeks, the anastomoses were opened longitudinally and fixed to determine the anastomotic index (AI). AI is defined as two times the anastomotic circumference over the proximal circumference plus the distal circumference. Blood flow groups and anastomotic technique groups were compared with an interaction variable for the outcome, AI using a two-way analysis of variance.

RESULTS

The AI of the stapled anastomoses was found to be significantly higher than handsewn anastomoses (P < 0.006). There was no difference in AI between different blood flow groups and no correlation of observed histologic findings with AI.

CONCLUSION

Clinically relevant ischemia does not directly influence stricture formation in either handsewn or stapled distal colonic anastomoses.

Does a proximal colostomy affect colorectal anastomotic healing?

Fecal diversion has been implicated as an etiologic factor in anastomotic stenosis following colorectal surgery, particularly following the use of circular anastomotic stapling devices. However, experimental confirmation of the effects of fecal diversion on anastomotic healing is virtually nonexistent. The purpose of this study was to serially evaluate colorectal anastomotic healing with proximal colostomy (COL) and without it (CON; control) using two anastomotic techniques in a porcine model. Fifty-two (28 CON; 24 COL) mixed-breed female pigs had colorectal anastomoses using either a two-layer hand-sewn (HS) or an EEA (U.S. Surgical Corporation, Norwalk, CT) circular stapled (CS) technique. Anastomotic blood flow was measured using laser Doppler velocimetry (LDV). At second surgery (5, 11, 60, or 120 days postoperatively), the following data were collected: repeat LDV, gross and microscopic anastomotic inflammatory scores, anastomotic diameter, and bursting pressure. There were no significant differences in anastomotic blood flow (LDV), inflammatory scores, or incidence of leak or stenosis between the CON and COL groups or between anastomotic techniques. Bursting pressure was significantly lower for the COL group at day 11 but not any other postoperative day (POD). Proximal colostomy does not appear to exert adverse effects on colorectal anastomotic healing. The choice of colorectal anastomotic technique should not be influenced by the need for proximal colostomy.

A retrospective study of colostomies, leaks and strictures after colorectal anastomosis

A review was undertaken of 360 patients undergoing elective left-sided colonic or rectal resections with primary anastomosis, under the care of one surgeon, over a nineteen year period. The incidence, aetiology and management of anastomotic leaks and strictures was studied and the role of proximal diverting colostomy considered. Perioperative mortality was 2.7%. The incidence of anastomotic leaks was 24.4%. Leaks were more common when anastomoses were low, were sutured or were constructed by trainees. Strictures developed in 5.8%. Local recurrence of tumour was the cause of 25% of these strictures. Anastomotic leakage was the principal cause of benign strictures; those developing in association with leaks were more likely to require surgical intervention. There was no evidence that delay in colostomy closure contributed to the development of benign anastomotic strictures. It was not possible to determine whether the presence of a colostomy affected the incidence of leaks but the local effects of such leaks were mitigated in patients with colostomies. Where a minor leak had occurred it was not necessary to wait for complete anastomotic healing before closing the colostomy. After major leaks, colostomy closure before complete healing was associated with further anastomotic problems in 16.0% of cases.

Colorectal anastomotic stenosis. Results of a survey of the ASCRS membership

Anastomotic stenosis is a poorly understood and underexamined complication of gastrointestinal surgery, reportedly most frequent in the coloproctostomy. In order to better define this problem, a questionnaire was sent to members of the American Society of Colon and Rectal Surgeons regarding patients with gastrointestinal anastomotic stenosis. A total of 123 patients with intestinal anastomotic stenosis were analyzed. Eighty-two anastomoses were stapled and 41 were handsewn. Nearly all stenoses occurred in the distal bowel (70 rectal, 23 sigmoid colon). Preoperative risk factors identified were obesity (28 patients) and abscess (12 patients). Incomplete "doughnuts" were noted in 12 patients. Postoperative anastomotic leaks (15 patients), pelvic infection (13 patients), and postoperative radiation (7 patients) were believed to be contributing factors. Dilatation, using a variety of techniques, was the sole treatment for 65 patients, however, intra-abdominal surgery was necessary in 34 patients. Large intestinal anastomotic stenosis probably occurs most commonly following coloproctostomy (both with handsewn and stapled anastomoses). Dilatation alone resulted in adequate treatment in most patients in the study. Major surgery was required to correct this problem in a significant number of patients (28 percent) in this series. The true incidence of anastomotic stenosis in colorectal surgery is unknown and warrants further study.

Comparison of the Valtrac biofragmentable anastomosis ring with conventional suture and stapled anastomosis in colon surgery. Results of a prospective, randomized clinical trial

In a randomized, prospective study of 438 patients, the safety and efficacy of the Valtrac biofragmentable anastomotic ring (BAR) was compared with stapling and with conventional suture techniques. There was no significant difference in the morbidity, mortality, and clinical course of the patients. The BAR can effect reestablishment of intestinal continuity somewhat more rapidly, but its major advantage is its uniform applicability to all areas of the intestinal tract, except the low rectum.

Local recurrence following surgical treatment of rectal cancer. Comparison of anterior and abdominoperineal resection

Three hundred twenty patients with rectal cancer were studied to determine factors that correlate with development of pelvic recurrence. The mean age was 65 years; anterior resection was performed in 202 (63 percent) and abdominoperineal resection in 118 (37 percent). Fifty-two patients (16 percent) developed pelvic recurrence. The mean duration of follow-up to development of pelvic recurrence was 22 months. Depth of tumor invasion, presence of lymph node metastasis, and colloid features were found to correlate with pelvic recurrence. The recurrence rate in patients having anterior resections was the same as that of patients undergoing abdominoperineal resections. Patients having anterior resection with distal margins of 1 cm or less had an extremely high recurrence rate (36 percent). Pelvic recurrent did not continue to improve when the distal margins were extended over 2 cm. Microscopic lateral tumor extension, which is not removed during operation, appears to be the major determinant of local recurrence in rectal cancer.