Obesity increases the risk of postoperative peripheral neuropathy after minimally invasive colon and rectal surgery.

BACKGROUND: Abdominal surgery in the obese can be a major challenge in the perioperative period. Peripheral neuropathy is an uncommon but well-described complication after abdominal surgery.
OBJECTIVE: Our aim was to evaluate the incidence of postoperative peripheral neuropathy after colorectal surgery and to identify its risk factors.
DESIGN: A retrospective review of a prospectively maintained database of consecutive patients undergoing colorectal operations was performed. The incidence of postoperative nerve injury was compared between minimally invasive and open surgeries. BMI and other potential risk factors for developing peripheral neuropathy were evaluated. SETTINGS: This investigation was conducted at a single institution. PATIENTS: Over a 7-year period, 1514 colorectal operations were performed. 945(62.4%) of these operations were performed either laparoscopically or via hand-assisted laparoscopy, 166 (11.0%) were robotic assisted, and 403 (26.6%) were open procedures. Twenty-three patients (1.5%) developed peripheral neuropathy in the postoperative period. MAIN OUTCOME MEASURES: Forward stepwise logistic regression was used for multivariate analysis.
RESULTS: All 23 of the patients with peripheral neuropathy had sensory deficits, and 1 patient had both sensory and motor deficits. All of the symptoms resolved without any residual neurologic deficits within 1 year. Twenty-two of the 23 patients with peripheral neuropathy were in the minimally invasive surgery group (incidence, 2%). One patient from the open group had peripheral neuropathy. By logistic regression analysis, only BMI was an independent predictor for peripheral neuropathy (p = 0.016) in minimally invasive surgery. LIMITATIONS: A limitation of our study is that postoperative neuropathy identification depended on reporting of symptoms, and there was no objective method of assessment. In addition, because of the relatively small number of patients with postoperative neuropathy, the study may be underpowered to detect significant differences in potential risk factors for developing neuropathy.
CONCLUSIONS: The incidence of postoperative peripheral neuropathy was 2.0% in minimally invasive surgery and 0.2% in open surgery. Minimally invasive surgery, age, lithotomy positioning, operative time, and Pfannenstiel incision all significantly increased the risk of peripheral neuropathy. However, only obesity was an independent risk factor for peripheral neuropathy in patients undergoing minimally invasive colorectal surgery. Preventive measures should be instituted and documented in obese patients undergoing minimally invasive colorectal procedures.