UroToday.com - Erectile dysfunction is one of the most relevant functional complications following radical prostatectomy. No study had analyzed the predictors of potency recovery in a series of patients undergoing robot-assisted laparoscopic radical prostatectomy (RALP).

Moreover, Briganti et al. recently evaluated the recovery of erectile function following retropubic radical prostatectomy, identifying three different risk groups. Specifically, patients aged ≤ 65 years, with a baseline IIEF > 21 and Charlson score ≤ 1 were considered to be at low-risk; intermediate-risk included patients aged 66 - 69 years, with a baseline IIEF-6 score ranging 11 and 21 and Charlson score ≤ 1. Finally, patients aged 70, with IIEF- 6 score ≤ 10 and Charlson score ≥ 2 identified a high-risk group of postoperative ED.

The aim of our study was to evaluate the preoperative factors predictive of potency recovery in a series of patients undergoing RALP and to validate the Briganti risk stratification. We analyzed the data regarding 415 consecutive patients who underwent bilateral nerve sparing RALP for clinically localized prostate cancer between April 2005 and April 2009, with a minimum follow-up of 12 months; we excluded patients that received neoadjuvant or adjuvant hormonal therapy and adjuvant radiation therapy.

All patients were evaluated for age at diagnosis, BMI, comorbidity according to Charlson score, preoperative total serum PSA, prostate volume at preoperative TRUS, biopsy Gleason score, clinical stage according to 2002 TNM, and risk groups according D'Amico class. We evaluated the following pathological parameters: Gleason score, perineural and endovascular invasion, pathologic extension of the tumor according to the 2002 TNM and presence of positive surgical margins.

Urinary continence at follow-up was evaluated using the ICI-Q short form questionnaire and erectile function was evaluated using the International Index of Erectile Function (IIEF-6), both before and at 12 months after surgery. We defined as potent patients with a IIEF ≥ 18, regardless of the use of phosphodiesterase 5 inhibitors.

188 patients (90.4%) were continent and 120 patients (62%) were potent 12 months after RALP. The median time to erectile function recovery was 6 months (IQR: 2-10). Moreover, 112 (54%) patients returned to a preoperative level of erectile function, 44 of those (39%) using phosphodiesterase type 5 inhibitors (PDE5-is).

At multivariate analysis, age (HR 2.8; p<0.0001), Charlson score (HR: 2.9; p=0.007) and baseline IIEF-6 score (HR 0.843; p<0.001) turned out to be independent predictors of potency recovery.

According to the Briganti et al. risk group stratification, the 12 months potency rate following RALP was 81.9% in the low-risk group, 56.7 % in intermediate risk group and 28.6% in high risk group (p<0.001). Moreover, we stratified the intermediate risk group in two subgroups according to the baseline IIEF-6 score: IIEF- 6 18 - 21 showed potency rates of 68.8% and scores 11-17 showed a potency rate of 27%, demonstrating that the only difference between potent and non-potent patients was represented by the baseline IIEF-6 score.

Our study is the first external validation of this novel risk group stratification. Considering the numerous methodological issues related to the assessment of erectile function, the evaluation of erectile function recovery is a critical point.

A secondary analysis of our study showed that penile rehabilitation does not improve the erectile function recovery in comparison with the on demand use of PDE5-is: this data reconfirmed the result of the REINVENT study.

The limitations of our study are the number of evaluated patients and the median follow up (only 14 months), but the major strength of this study is the accurate methodology for prospective data collection, which fulfils most of the criteria suggested by Mulhall. In conclusion, the key point for the success of the nerve sparing technique is a good selection of patients; age ≤ 65 years, no associated comorbidities, and good preoperative erectile function represent the most important preoperative factors for selecting patients to nerve sparing RALP.

Written by Giacomo Novara, MD, FEBU, as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations, etc., of their research by referencing the published abstract.

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