Evaluation of the NiTi Shape Memory BioDynamix ColonRing™ in colorectal anastomosis: first in human multi-center study

Shape-memory compression bowel anastomosis using a nickel and titanium alloy may reduce leak rates and eliminate foreign anastomotic material. Its safety and efficacy had been demonstrated by animal studies. We conducted the first prospective multi-center clinical evaluation of the safety and effectiveness of BioDynamix anastomosis with ColonRing™ for large-bowel end-to-end or side-to-end anastomosis.

The ColonRing™ was compared to the standard double-stapled colorectal/colocolonic anastomosis. Intraoperative and immediate postoperative and 1- and 3-month postoperative follow-up data were recorded.

Ten study patients (four males, median age 62 years, range 35–75) were compared to 13 demographically matched controls (six males, median age 62 years, range 47–82). Colorectal neoplasia was the most frequent indication for surgery (21/23 patients, 91%). The median anastomotic distance from the anal verge for both groups was 10 cm (6–20 cm). The first postoperative bowel movement was on day 5 ±2.2 (study group) and on day 4 ±1.8 (controls), and the median hospital stay was 8 days (6–14 days) and 7 days (6–13 days), respectively. There were no anastomotic leaks. There were three minor complications in each group, unrelated to the device in the study group. Two patients required transanal digital extraction of the ring which was detached but not expelled (one had a soft anastomotic stricture).

Our preliminary results in this first study on humans indicate that the safety and efficacy of BioDynamix anastomosis with ColonRing™ in colorectal anastomosis in human is comparable to standard staples technology and warrant larger studies for further validation.