Anastomotic dehiscence (AD) in colorectal cancer surgery: mechanical anastomosis versus manual anastomosis

Introduction: Anastomotic dehiscence (AD) is the “Achilles heel" for resectional colorectal pathology and is the most common cause of postoperative morbidity and mortality. AD incidence is 3-8%; mortality rate due to AD two decades ago was around 60% and at present is 10% [4-6]. This paper analyzes the incidence of AD after colorectal resection performed both in emergency and elective situations, depending on the way it is done: manually or mechanically. Methods: Retrospective, single-center, observational study of patients operated in the period from 1st of January 2009 to 31th of December 2011 for malignant colorectal pathology in the Emergency Clinical Hospital of Bucharest. We evaluated the incidence of digestive fistulas according to the segment of digestive tract and time from hospital admission, to the way the anastomosis was achieved (mechanical vs. Manual), to the complexity of intervention, to the transfusion requirements pre/intra or postoperative, to the past medical history of patients (presence of colorectal inflammatory diseases: ulcerative colitis and Crohn's disease), to the average length of hospital stay and time of postoperative resumption of bowel transit. Results: We included 714 patients who had surgery between 1st of January 2009 and 31th of December 2011. 15.26% (109/714) of the cases were operated in emergency conditions. Of the 112 cases of medium and lower rectum, 76 have “benefited" from preoperative radiotherapy with a fistula rate of 22.36% (17/76). The incidence of anastomotic dehiscence in the group with preoperative radiotherapy and mechanical anastomosis was 64.7% (11/17) versus 35.3% (6/17) incidence recorded in the group with manual anastomosis. Colorectal inflammatory diseases have been found as a history of pathology in 41 patients - incidence of fistulas in this group was of 12.2% (5/41), compared to only 6.83% (46/673) incidence seen in patients without a history of such disease. For the group with bowel inflammatory disease, anastomotic dehiscence incidence was of 13.8% (4/29) when using mechanical suture and 8.3% (1/12) when using manual suturing. The period required for postoperative resumption of intestinal transit was of 3.12 days for mechanical suturing and 3.93 days in case of manual suture. The mean time (MT) to perform the ileocolic and colocolic mechanical anastomosis is 9 ± 2 minutes. If anastomosis is “cured" with surjet wire or separate threads, MT is 11 ± 5 minutes. MT to perform the ileocolic and colocolic manual anastomosis is 9 ± 3 minutes for surjet wire and 18 ± 5 minutes for separate threads. MT to perform the colorectal mechanical anastomosis is 15 ± 4 minutes. MT to perform the colorectal manual anastomosis is 30 ± 7 minutes (using separate threads). Detailing the nature of the surgical reinterventions, we have found: 7 reinterventions for AD post mechanical anastomoses (1 case of suture defect, 2 cases of resection and re-anastomoses, 4 cases with external branching stoma); 5 reinterventions for AD post manual anastomoses (0 cases of suture defect, 1 case of resection with re-anastomosis, 4 cases of external shunt stoma). In the analyzed group, we recorded a total of 57 deaths from a total of 714 cases resulting in a mortality rate of 7.98%. Conclusions: Mechanical suture technique is not ideal for making digestive sutures. With the exception of low colorectal anastomoses where mechanical sutures are preferable, we cannot claim the superiority of mechanical anastomoses over those manually made, for colorectal neoplasia.