Infrared parietal colorectal flowmetry: a new application of the pulse oximeter. Is this method useful for general surgeons in preventing anastomotic leakage after colorectal resections?

Abstract

Roberto Delfrate,1 Massimo Bricchi,1 Paolo Forti,1 Claude Franceschi2 1Surgery Unit, Figlie Di San Camillo Hospital, Cremona, Italy; 2Vascular Exploration Service, St Joseph Hospital, Paris, France Background: Anastomotic leak is a major complication of colorectal surgery. Among the causes of dehiscence, anastomotic ischemia seems to be fundamental and consequently so is the evaluation of the parietal flow. We proposed a new application of infrared flowmeter for the evaluation of the parietal flow at the stumps after colon resection. Objective: The aim of this study is to assess the feasibility of using an intraoperative intestinal wall flowmeter to assess arterial capillary flow in order to avoid the execution of anastomoses in poorly vascularized segments of bowel, and consequently to reduce the risk of anastomotic leakage.Methods: Retrospective analysis of two groups of patients with different methods of evaluation of colon resection stump vascularization. Ninety-two consecutive patients (Group A) underwent surgical colorectal resection for cancer. In this group, we used a pulse-oximetry sensor to assess the parietal flow: once the magnitude of the colon resection was established according to surgical and oncological criteria, the exact location of the resection was adjusted according to the parietal flowmetry curve. This method was compared with 139 consecutive colorectal resections (Group B) in which vascularization was assessed by checking the pulsatility of the mesenteric arteries, macroscopic wall resection stump appearance, and bleeding of the wall stump. The main outcome measure was the reduction in anastomotic dehiscence.Results: In Group A no anastomotic leakage occurred (0/92). Conversely, in Group B six anastomotic leaks occurred (6/139). The statistical analysis of the two groups thanks to the Fisher's exact test shows that P<0.05, which is statistically significant.Conclusion: We tested a new application of the pulse oximeter: the evaluation of the colon parietal flow (infrared parietal flowmeter). The infrared parietal flowmetry appears to be a feasible, simple, and low-cost method, able to detect the vascularization of the large bowel stump; for this reason this procedure appears to be useful in order to avoid a colon anastomosis of two poorly vascularized bowel stumps, thus reducing the risk of anastomotic leakage. Despite the positive results of our experience in the assessment of the intestine vascularization with the intraoperative infrared stump flowmeter, the possibility of reducing the number of anastomotic leaks through this method requires additional and more extensive trials. Keywords: anastomotic leak, colon resection, flowmetry