WCE 2017: A Prospective, Multi-Institutional Assessment of 90-Day Percent Fullness – Predictive Modeling of Potency Recovery Post-Robot Assisted Radical Prostatectomy

Vancouver, Canada (UroToday.com)  Erectile dysfunction is commonly encountered short and long term following radical prostatectomy (RP), with rates varying dramatically from 12 to 96% depending upon patient demographics, technique, and surgeon skill or experience. While the International Index of Erectile Function – 5 (IIEF-5) and erections sufficient for intercourse (ESI) are the most commonly used methods of assessment, they are neither sensitivity nor specific enough to predict long-term recovery of sexual function. 

Ms. Linda My Huynh (BS), a clinical research coordinator from the University of California – Irvine presents a novel 90-day percent fullness of erections scale as a predictive model for the long-term recovery of sexual function. Initially introduced as an adjunct to the IIEF-5, percent (%) fullness of erections is a single-item questionnaire to qualitatively assess postoperative fullness of erections compared to baseline. Over time, the potential for the % fullness scale to be a more complete description of partial erection recovery was recognized and internally validated at their institution. 

The present study is the first prospective, external validation of 159 pre-potent men from five different high-volume institutions. The % fullness scale is “how firm are your erections compared to before surgery?” was collected at 3, 6, and 12 months along with standard IIEF-5, with primary outcome as prediction of potency status at 1 year (defined as ESI). 

Of the 140 men with baseline IIEF-5 15-25, 106 (75.7%) had IIEF-5 < 15 and 91.1% of these reported IIEF-5 < 10. By this definition, therefore, only 22.6% recovered potency by one year. This further makes difficult the identification and treatment of patients who would require and would benefit from secondary interventions for erectile dysfunction. 

Given these weaknesses with the IIEF-5, the % erection fullness scale at 90 days allowed for a more sensitive and specific prediction of overall potency recovery. The lowest tertile (0-24%), for example, predicted that 11.9% would recover potency at 1 year. Conversely, the second tertile (25-74%) predicted a 42% recovery and the highest tertile (26/36) had 72.2% recovery by 1 year. In multivariate models, 90-day % fullness was an independent predictor of 1 year potency recovery. 

Overall, % erection fullness provides a single-item questionnaire at 90 days that predicts overall potency recovery at 1 and 2 years. With further external validation, the % fullness scale offers a promising predictive mechanism for identifying those who are most likely to benefit from secondary intervention. 

Presented by: Linda Huynh, (BS)

Authors: Linda My Huynh, Douglas Skarecky, Thomas E. Ahlering, MD
Affiliations: University of California, Irvine

Written by: Linda Huynh (BS), assistant research specialist, University of California, Irvine at 35th World Congress of Endourology– September 12-16, 2017, Vancouver, Canada.