Introduction: Nerve-sparing status (NSS) during RP is a significant predictor of erectile function recovery (EFR). Poor nerve sparing is associated with collagenization of cavernosal smooth muscle and CVOD development with typically poor response to PDE5 inhibitors (PDE5i) and intracavernosal injection therapy (ICI). This study aimed to define factors predictive of CVOD in men with bilateral NS RP.
Methods: Study population consisted of (i) men who underwent bilateral NS (defined by the surgeon using an institutional grading system) RP (ii) with poor response to PDE5i and ICI (iii) =2 years post-RP (iv) who underwent penile duplex Doppler ultrasound (DUS) (v) using a vasoactive agent redosing schedule. CVOD diagnosis was made with end-diastolic velocity (EDV) values =5 cm/sec bilaterally. ADT and radiation therapy were exclusions. We used multivariable modeling to define factors predictive of CVOD. Factors included in the model: patient age, history of diabetes, history of obstructive sleep apnea, number of vascular comorbidities, baseline EF, peri-RP total testosterone (T) level, and total T at DUS (within 3 months).
Results: 201 men with a mean age of 66 ± 7 years. 25% of the patients reported 3 or more vascular comorbidities, 17% had diabetes, 36% obstructive sleep apnea, 39% were current or former smokers. Mean baseline PSA and pre-RP total T was 6.7 ± 6 ng/mL and 410 ± 211 ng/dL, respectively. Median baseline EFD score was 24 (13, 29). 49% of the men had an erection less than penetration rigidity during the DUS procedure with a mean total dose administered of 87 ± 21 units of trimix. 69% received 100 units. CVOD was diagnosed in 76%. Mean total T at DUS was 386 ± 177 ng/dL. 32% had low T. Significant predictors of CVOD after RP in men with BL NSS were: OSA (OR = 3.8, 95% CI = 1.7-8.7), = 3 vascular comorbidities (OR = 5.0, 95% CI = 1.7-14.8), age at the time of DUS (per 10 years increase, OR = 1.9, 95% CI = 1.2-3.0), and pre-RP EF domain score (per 1 unit increase, OR = 0.93, 95% CI 0.88-0.98). There was a signal that in a larger sample size, diabetes may be a significant predictor of CVOD in this group of patients (OR = 2.7, 95% 0.9-8.0).
Conclusions: Baseline clinical comorbidities pre-RP have a significant impact on EFR post-RP, in particular, the presence of venous leak. Despite BL NSS, older patients, men with OSA, higher number of comorbidities pre-RP, and lower pre-RP EF increased the likelihood of developing CVOD post-RP.