Factors affecting morbidity after conversion of laparoscopic colorectal resections

The impact of conversion on postoperative outcomes of laparoscopic colorectal surgery remains controversial. The purpose of this study was to assess whether a conversion results in increased postoperative morbidity and mortality, and to evaluate whether any specific factors affect the outcomes of converted procedures.

Outcomes of procedures requiring conversion among patients undergoing elective laparoscopic colorectal resection between 1992 and 2011 were compared with those for operations completed laparoscopically. Subset analyses were also performed to evaluate the selective impact of patient-, disease- and treatment-related factors and the timing of conversion during surgery on outcomes. Primary endpoints were postoperative mortality and morbidity.

Of 2483 patients undergoing laparoscopic colorectal resection, 270 (10.9 per cent) required conversion to open surgery. The 30-day postoperative mortality rate was comparable after laparoscopically completed and converted procedures (0.4 versus 0 per cent respectively; P = 0.610). Factors significantly associated with morbidity after conversion were smoking, cardiovascular co-morbidity, previous abdominal operations (particularly colectomy or hysterectomy) and adhesions. Overall morbidity was not affected by conversion (27.0 per cent at 30 days in both groups; P > 0.999). However, patients experiencing morbidity tended to have had earlier conversions: median (range) 40 (15-90) min into surgery versus 50 (15-240) min for those who did not develop morbidity (P = 0.006). The risk of reoperation for postoperative morbidity was higher following conversion because of complications (13 versus 2.9 per cent; P = 0.024).

Conversions of laparoscopic colorectal resection are not associated with increased overall morbidity, regardless of the timing of conversion.