GI Cancer

Tips & Tricks For Safe Anastomosis In Minimally Invasive Colorectal Surgery

Part B.   Intraoperative assessment of anastomotic integrity

This is second part in series of the blog ‘Tips & tricks for safe anastomosis in minimally invasive colorectal surgery’ (

Anastomotic leak (AL) is the most feared complication of colorectal anastomosis (CRA) with a reported incidence of 8.1% after right hemicolectomy and 5.8% after high anterior resection and 10.8% after low anterior resection1.

The attributes of ‘Safe’ intestinal anastomosis include tension free anastomosis between well vascularised bowel segments. In the era of open surgery, surgeons assessed the latter by a combination of observation (‘ healthy’ color and pulastile bleeding at cut end of the bowel) and palpation (arterial pulsations in the mesocolon). In MIS, options available to the surgeons are more limited and viability of the colon following resection and subsequent anastomosis is determined largely by observing the color.

However the predictive accuracy of surgeons’ clinical risk assessment for AL is reported to be low and is not influenced by training level (surgeon versus assistant surgeons)2.

To make this assessment less observer dependent and to more objectively assess anastomotic integrity and tissue perfusion, several intraoperative tests have been introduced in clinical practice over last few years.

  1. Intraoperative air leak test (ALT): For left sided anastomosis, the test is simple and performed by insufflating the rectum with air while submerging the anastomosis3.
  2. Intraoperative flexible sigmoidoscopy for assessment of colorectal anastomosis (CRA): This is a safe and reliable method for direct assessment of anastomotic integrity as well as bleeding 4. More commonly performed in units where surgeons themselves are trained to perform colonoscopy.
  3. Intraoperative Indocyanine Green (ICG) fluorescence imaging: Intraoperative ICG imaging is a simple reproducible technique for real time assessment intestinal perfusion 1. The data from non randomized studies on the subject suggests decreased anastomotic leak following ICGA5,6. However results of a recent multicenter randomized controlled trial from Italy suggests that while ICGA can effectively assess vascularisation of the colic stump and anastomosis and led to further proximal resection in 11% of patients, there was no statistically significant reduction of anastomotic leak in the ICGA arm. Further one multicenter phase II trial investigating the role of ICG imaging in elective CRS has reported that while the technique helped reduce AL rates in left sided resections  – particularly LAR, it did not add any value to outcomes following  ileocolic anastomoses 

CommentsWe routinely do the intraoperative ALT for left sided anastomoses. For the right side, we perform extracorporeal anastomosis and have not introduced ICG fluorescence imaging. For elective CRS the overall AL in our unit is 5.08%


  1. Ris E, Liot E, Buchs NC et al Multicenter phase II trial of near infrared imaging in elective colorectal surgery Br J Surg 2018;105:1359-1367

  1. Karliczek A, Harlaar NJ, Zeebregts CG et al. Surgeons lack predictive accuracy for anastomotic leakage in gastrointestinal surgery. Int J Colorectal Dis 2009;24(5):569-76

  1. Monson JR, Weiser MR, Buie WD et al. Practice parameters for the management of rectal cancer (Revised) Dis Colon Rectum. 2013;56(5):535-50.

  1. Kamal T, Pai A, Velchuru VR et al. Should anastomotic assessment with flexible sigmoidoscopy be routine following laparoscopic restorative left colorectal resection? Colorectal Dis 2015;17(2):160-4

  1. Shen R, Zhang Y, Wang T Indocyanine Green Fluorescence Angiography and the incidence of anastomotic leak after colorectal resection for colorectal cancer: A Meta Analysis. Dis Colon Rectum 2018;61(10):1228-1234

  1. Blanco-Colino R, Espin –Basany E. Intraoperative use of ICG fluorescence imaging to reduce the risk of anastomotic leakage in colorectal surgery: a systematic review and meta- analysis. Tech Coloproctol 2018;22(1):15-23

  1. Nardi De, Elmore U, Maggi G et al. Intraoperative angiography with indocyanine green to assess anastomosis perfusion in patients undergoing laparoscopic colorectal resection: results of a multicenter randomized controlled trial. Surg Endosc 2019;doi:10.1007/s00464-019-06730-0



Dr Nitin Vashistha, MS, FIAGES, FACS

Dr Dinesh Singhal, MS, FACS, DNB (Surg Gastro)

Department of Surgical Gastroenterology,
Max Super Speciality Hospital, Saket, New Delhi, India
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