Does elevated body mass index (BMI) affect the clinical outcomes of robot-assisted laparoscopic prostatectomy (RALP): A prospective cohort study

Objectives: With the prevalence of obesity in the United States, a significant proportion of robot-assisted laparoscopic prostatectomy (RALP) candidates have an elevated body mass index (BMI). We determine if this impacts on the clinical outcomes of RALP. Methods: 218 consecutive patients underwent RALP were identified from a prospectively maintained RALP database recorded and compared for their demographics, clinical outcomes and adverse events in normal weight (BMI <25kg/m²), overweight (BMI ≥25 and <30kg/m²) and obese (BMI ≥30kg/m²) groups. Results: 36 normal weight, 115 overweight and 67 obese patients were identified. There were no significant differences in demographic data among the three groups except for mean BMI (23.1 vs. 27.5 vs. 32.8kg/m², p<0.001). The median operative time was longer in obese patients compared to both overweight (210 vs. 189min, p=0.031) and normal weight (210 vs. 177min, p=0.008) patients. There were no significant differences in median estimated blood loss, mean prostate volume, positive surgical margin rate and time to continence without pads. The median urethral catheter duration and hospitalization were similar in all groups. Patients with elevated BMI had a significantly higher median Gleason score (p=0.046) and incidence of pathologic T3 disease (p=0.038). The incidence of adverse events was low and there were no significant differences among the three groups (p>0.05).Conclusions: Elevated BMI appears to increase the RALP operative time, but has little impact on other intraoperative parameters, clinical outcomes or patient morbidity. RALP is a safe and effective procedure in patients with elevated BMI.