The cost of conversion in robotic and laparoscopic colorectal surgery.

BACKGROUND: Conversion from minimally invasive to open colorectal surgery remains common and costly. Robotic colorectal surgery is associated with lower rates of conversion than laparoscopy, but institutions and payers remain concerned about equipment and implementation costs. Recognizing that reimbursement reform and bundled payments expand perspectives on cost to include the entire surgical episode, we evaluated the role of minimally invasive conversion in total payments.

METHODS: This is an observational study from a linked data registry including clinical data from the Michigan Surgical Quality Collaborative and payment data from the Michigan Value Collaborative between July 2012 and April 2015. We evaluated colorectal resections initiated with open and minimally invasive approaches, and compared reported risk-adjusted and price-standardized 30-day episode payments and their components.

RESULTS: We identified 1061 open, 1604 laparoscopic, and 275 robotic colorectal resections. Adjusted episode payments were significantly higher for open operations than for minimally invasive procedures completed without conversion ($19,489 vs. $15,518, p < 0.001). The conversion rate was significantly higher with laparoscopic than robotic operations (15.1 vs. 7.6%, p < 0.001). Adjusted episode payments for minimally invasive operations converted to open were significantly higher than for those completed by minimally invasive approaches ($18,098 vs. $15,518, p < 0.001). Payments for operations completed robotically were greater than those completed laparoscopically ($16,949 vs. $15,250, p < 0.001), but the difference was substantially decreased when conversion to open cases was included ($16,939 vs. $15,699, p = 0.041).

CONCLUSION: Episode payments for open colorectal surgery exceed both laparoscopic and robotic minimally invasive options. Conversion to open surgery significantly increases the payments associated with minimally invasive colorectal surgery. Because conversion rates in robotic colorectal operations are half of those in laparoscopy, the excess expenditures attributable to robotics are attenuated by consideration of the cost of conversions.