Outcomes of Extraperitoneal Robot-Assisted Radical Prostatectomy in the Morbidly Obese: A Propensity Score-Matched...

An increasing number of obese patients (body mass index [BMI] >30 kg/m(2)]) with localized prostate cancer are presenting as candidates for robot-assisted radical prostatectomy (RARP), which can be carried out using the transperitoneal or the extraperitoneal (EP) approach. Morbidly obese (BMI >40 kg/m(2)) patients present as an especially challenging surgical cohort. We sought to evaluate the perioperative and pathologic outcomes associated with EP-RARP in morbidly obese men.

In this institutional review board-approved study, our prospectively collected database (Cancer Information Systems [CAISIS]) was reviewed. One thousand six hundred sixty-three patients underwent EP-RARP for localized prostate cancer at our institution between July 2003 and December 2013 by a single surgeon. Forty patients were considered morbidly obese. A propensity score-matched analysis was performed using multivariate analysis incorporating 10 covariates to identify the comparable group of patients with a BMI of >40 kg/m(2) and <40 kg/m(2).

Apart from BMI, the two groups were matched (all p-values >0.05). Despite a higher total operating time and estimated blood loss (EBL) in the morbidly obese (238 vs 176 minutes, p<0.0001, and 235 vs 192 mL, p=0.003, respectively), there were no differences in the ability to perform nerve-sparing or pelvic lymphadenectomy, or the length of stay. While the morbidly obese had a higher rate of harboring more aggressive disease on final pathology (pT3 rates, 27.5 vs 7.5%, respectively), there were no differences in other postoperative pathologic parameters, such as prostate specimen weight, positive surgical margin status, and Gleason score sum. Moreover, there were no differences in intra- or postoperative complications between the two groups.

The morbidly obese cohort harbored more aggressive disease with the difference in the proportion of pathologic T3 disease statistically significant. Apart from increased total operating time and EBL in the morbid obese, EP-RARP leads to comparable perioperative and pathologic outcomes to the nonmorbidly obese. Consideration should be given to added operating room time when operating on the morbidly obese.