Anastomotic leak is one of the most feared complications in colorectal surgery, with significant resultant morbidity and mortality. Etiologies of anastomotic leaks are varied, multifactorial, and have been well described in the literature (C01, C02). Several methods have been described in the quest to minimize rates of anastomotic leak in colorectal surgery; the most promising technology is definitely the real-time intraoperative perfusion assessment of the anastomosis using fluorescence angiography (C03, C04).
Table 1 summarizes most of the major studies evaluating colorectal anastomosis perfusion using ICG based fluorescence angiography. (Table 1)
There are a variety of NIR systems currently on the market, however all of them have been shown to be accurate and with technical success approaching 100% in most publications.
The dosage of ICG that has been reported varies significantly between different publications and ranges from 3.75-10mg or in the range of in the range of 0.1–0.3 mg/kg. However, the dose administered has not affected the technical success of the fluorescence angiography, and probably is not of significant importance as the maximal safe dose of ICG (2 mg/kg) has not been administered. Use of ICG based fluorescence angiography is perhaps surprisingly safe with no significant adverse effects reported.
Review of the current literature regarding perfusion assessment in colorectal surgery demonstrates that fluorescence angiography is usually associated with low rates of anastomotic leak. As shown in table 1, the combined average leak rate in more than 2000 patients who underwent fluorescence angiography 2.9%, and change in surgical plans (mainly change in resection point) happened in 9.4% of the patients.
There was one major multicenter prospective randomized trials evaluating fluorescence angiography in colorectal surgery. The Pillar III trial intended to evaluate approximately 550 patients undergoing open or minimally invasive proctectomy for rectosigmoid cancer, with a planned anastomosis of ≤10 cm from the anal verge. The primary end point was a reduction in leak rate and the secondary end points included technical feasibility and change in surgical plan. However, unfortunately, this trial was terminated after 330 patients.
We believe that there is enough evidence to support the claim that fluorescence angiography plays a significant role in reduction of anastomotic leaks in colorectal surgery, and we are confident that the results from both prospective randomized trials will reflect our opinion.
References
C01. Shogan BD, Carlisle EM, Alverdy JC, et al. Do we really know why colorectal anastomoses leak? J Gastrointest Surg. 2013;17(9):1698–1707.
C02. Al Asari S, Cho MS, Kim NK. (2015) Safe anastomosis in laparoscopic and robotic low anterior resection for rectal cancer: a narrative review and outcomes study from an expert tertiary center. Eur J Surg Oncol 41(2):175–185
C03. Chadi, S.A., et al., Emerging Trends in the Etiology, Prevention, and Treatment of Gastrointestinal Anastomotic Leakage. J Gastrointest Surg, 2016. 20(12): p. 2035-2051.
C04. Vallance, A., et al., A collaborative review of the current concepts and challenges of anastomotic leaks in colorectal surgery. Colorectal Dis, 2017. 19(1): p. O1-O12.
View recorded webinar from 31 August, 2018
