Robotic-Assisted Colorectal Surgery in Obese Patients: A Case-matched Series

Jeffrey N Harr, MD, MPH¹, Samuel Luka, MD¹, Aman Kankaria², YenYi Juo, MD, MPH¹, Samir Agarwal, MD¹, Vincent Obias, MD¹. ¹The George Washington University, ²University of Maryland College Park

INTRODUCTION – Laparoscopic colorectal surgeries in obese patients have higher conversions to laparotomy and complications, including increased surgical site infections, operative times, blood loss, and length of stay. Several advantages of robotic-assisted surgery have been reported, and may decrease complications in higher risk obese patients. Therefore, this study evaluates outcomes of robotic-assisted surgery in non-obese and obese patients.

METHODS AND PROCEDURES – A retrospective review of 331 consecutive planned procedures performed by a colorectal surgery group at a single academic institution using the da Vinci robotic system between October 2009 and July 2015 was performed.  Patients were divided into non-obese (BMI < 30 kg/m²) and obese (BMI > 30 kg/m²) groups, and were clinically matched by gender, age, and procedure. Intraoperative and postoperative complications, operative time, estimated blood loss, and length of stay were examined.  Comparison of means between groups were analyzed using a two-tailed student’s t-test, and a two-tailed Fisher’s exact test was used to evaluate the number of specific complications and conversions to laparotomy between groups.

RESULTS – Following case matching, each group included 108 patients comprised of 50 men and 58 women. Patient demographics did not differ except for a mean BMI of 24.6±3.15 and 36.2±5.67 kg/m² (p<0.0001).  Surgeries included low anterior resection (N=60), right colectomy (N=60), sigmoid colectomy (N=38), left colectomy (N=30), excision of rectal endometriosis (N=6), total proctocolectomy (N=4), abdominal pernineal resection (N=4), subtotal colectomy (N=4), ileocecectomy (N=2), proctectomy (N=2), rectopexy N=2), transanal excision of rectal mass (N=2), and colostomy site hernia repair (N=2). Mean operative time (272.69±115.43 vs 282.42±120.51 min; p=0.55), estimated blood loss (195.23±230.37 vs 289.19±509.27 mL; p=0.08), and length of stay (5.38±4.94 vs 4.56±4.04 days; p=0.18) did not differ between groups. There was no difference in overall complications between non-obese and obese patients (20 vs 27; p=0.30). However, when evaluating specific complications, obese patients had a higher prevalence of wound complications (9.3% vs 1.9%; p=0.03).  After stratifying groups by abdominal and pelvic surgeries, obese patients undergoing abdominal colon surgery had a higher prevalence of complications (30.9% vs 14.7%; p=0.04) with 71.4% involving wound complications.

CONCLUSION – Laparoscopic colorectal surgery has been associated with increased laparotomy and complication rates in obese patients. However, robotic-assisted surgery may minimize conversion to laparotomy and complications due to improved 3-D visualization, wristed instrumentation, and surgeon ergonomics.  Despite this, wound complications continue to have a higher prevalence in obese patients.