Suitability of outpatient or ambulatory extended recovery cancer surgeries for obese patients

Study objective: An increasing number of overweight and obese patients are presenting for ambulatory surgical procedures and may be at risk of complications including longer surgeries, longer length of stay (LOS), and possible increase in unanticipated return visits or hospital admissions.

Design: Observational study using prospectively-collected data.

Setting: Freestanding and hospital-based ambulatory surgery facilities.

Patients and interventions: 13,957 patients underwent ambulatory cancer surgery procedures at the Josie Robertson Surgery Center (JRSC) since opening in 2016, and 4591 patients eligible for ambulatory surgery at JRSC underwent surgery at the main hospital during the same timeframe.

Measurements: We assessed whether BMI was associated with increased operative time, post-operative LOS, hospital transfer after surgery, or hospital readmission or urgent care center visits within 30 days. Using multivariable logistic regression, we assessed whether BMI was associated with decision to do surgery at JRSC controlling for age, ASA score and surgical service.

Main results: While higher BMI was associated with a higher rate of transfer out of JRSC (p = 0.014), the difference in rate was small (mean risk 0.8% for BMI 25 vs 1.3% for BMI 40, difference in risk 0.52%, 95% CI 0.05%, 1.0%). We found no evidence that higher BMI increased the risk of urgent care visits or readmissions within 30 days or outpatient LOS (p = 0.7 for all). There was a statistically but not clinically significant difference in operative time for outpatient procedures (p = <0.0001), with a mean operative time of 59 vs 63 min for BMI 25 vs 40. Ambulatory extended recovery patients with higher BMI had shorter operative times (p < 0.0001). Patients with higher BMI were not significantly less likely to undergo surgery at JRSC (84% vs 83% vs 82% probability of treatment at JRSC for BMI 25, BMI 40 or BMI 50, respectively, p = 0.089).

Conclusions: Ambulatory cancer surgeries can be performed safely among clinically eligible patients. Patients with BMI up to 50 or more can be treated safely in an ambulatory setting if they otherwise meet eligibility criteria.