Incidence, Associated Risk Factors, and Impact of Conversion to Laparotomy in Elective Minimally Invasive Sigmoidectomy for Diverticular Disease

Background: Benefits of minimally invasive surgical approaches to diverticular disease are limited by conversion to open surgery. A comprehensive analysis that includes risk factors for conversion may improve patient outcomes.

Methods: The US Premier Healthcare Database was used to identify patients undergoing primary elective sigmoidectomy for diverticular disease between 2013 and September 2015. Propensity-score matching was used to compare conversion rates for laparoscopic and robotic-assisted sigmoidectomy. Patient, clinical, hospital, and surgeon characteristics associated with conversion were analyzed using multivariable logistic regression, providing odds ratios for comparative risks. Clinical and economic impacts were assessed comparing surgical outcomes in minimally invasive converted, completed, and open cases.

Results: The study population included 13,240 sigmoidectomy patients (8076 laparoscopic, 1301 robotic-assisted, 3863 open). Analysis of propensity-score-matched patients showed higher conversion rates in laparoscopic (13.6%) versus robotic-assisted (8.3%) surgeries (p < 0.001). Greater risk of conversion was associated with patients who were Black compared with Caucasian, were Medicaid-insured versus Commercially insured, had a Charlson Comorbidity Index ≥ 2 versus 0, were obese, had concomitant colon resection, had peritoneal abscess or fistula, or had lysis of adhesions. Significantly lower risk of conversion was associated with robotic-assisted sigmoidectomy (versus laparoscopic, OR 0.58), hand-assisted surgery, higher surgeon volume, and surgeons who were colorectal specialties. Converted cases had longer operating room time, length of stay, and more postoperative complications compared with minimally invasive completed and open cases. Readmission and blood transfusion rates were higher in converted compared with minimally invasive completed cases, and similar to open surgeries. Differences in inflation-adjusted total ($4971), direct ($2760), and overhead ($2212) costs were significantly higher for converted compared with minimally invasive completed cases.

Conclusions: Conversion from minimally invasive to open sigmoidectomy for diverticular disease results in additional morbidity and healthcare costs. Consideration of modifiable risk factors for conversion may attenuate adverse associated outcomes.