Conversion in laparoscopic colorectal cancer surgery: impact on short- and long-term outcome

Despite the well-documented safety and effectiveness of laparoscopic colorectal surgery in curative intention, the role of conversion and its impact on short- and long-term outcome after resection of a carcinoma are unclear and continue to give rise to controversial discussion.

Within the framework of a prospective, multicenter observational study (Laparoscopic Colorectal Surgery Study Group), into which a total of 5,863 patients from 69 hospitals were recruited over a period of 10 years, a subgroup of all patients who had undergone curative resection was analyzed with regard to the effects of conversion.

Of the 1409 patients who had undergone curative resection for colorectal carcinoma, conversion had to be performed in 80 (5.7%) cases for the most diverse reasons. The duration of surgery (median: 183 vs. 241 minutes; P<.001) was significantly longer in the conversion group. Perioperatively, significant disadvantages were noted in converted patients in terms of intraoperative blood loss (median: 243 vs. 573 mL, P<.001), need for perioperative blood transfusion (10.8% vs. 33.8%; P<.001), and resumption of bowel movement (median: after 3 vs. 4 days; P<.001). With regard to postoperative morbidity, significant disadvantages were observed in converted patients, in particular in terms of specific surgical complications, including a higher rate of anastomotic insufficiency (5.0% vs. 13.8%; P=.003) and a higher reoperation rate (4.9% vs. 15.0%; P=.001). In the long term, conversion was associated with lower overall survival, but not with poorer disease-free survival.

Significantly higher postoperative morbidity was observed in patients after conversion, in particular in terms of specific surgical complications. In addition, conversion is associated with overall lower survival but not with poorer disease-free survival.