(175) IDENTIFYING RISK FACTORS FOR PRIAPISM IN MEN USING TRIMIX INJECTIONS FOR ERECTILE DYSFUNCTION AFTER PELVIC SURGERY
Authors: Slovacek H , Mahdi M , Khalaf Alla K , Majzoub A , Jacob J , Wang R 
Published: December 2024

Abstract

Introduction
Trimix intracorporal injections (ICI) is a standard treatment option for men suffering from erectile dysfunction (ED) who have failed oral medications. Men can acquire ED for many different reasons, however prior pelvic surgery is a common culprit. While ICI can help these men achieve satisfactory erections, it can sometimes be difficult to establish optimal dosing with men either not achieving a satisfactory erection or suffering from prolonged erection and priapism.

Objective
This study investigates whether specific clinical characteristics and penile Doppler ultrasound (PDU) parameters can predict a man's susceptibility to priapism when using ICI for ED.

Methods
We completed a retrospective chart review of our institution's database to identify patients who experience erectile dysfunction due to pelvic surgery. We identified 233 patients from a single institution who visited the Sexual Medicine clinic, then underwent penile doppler ultrasound (PDU), then started Trimix ICI (Alprostadil 30mcg/ml, phentolamine 1 mg/ml, papaverine 10 mg/ml) with a minimum of six months follow-up. The investigation comprised data gathered from 233 patients meeting these criteria between 2013 and 2023. Of these patients, 15 developed priapism either initially during in-office PDU with ICI or subsequently while using the medication at home. Data regarding patients’ clinical parameters, PDU reading (dose of the procedure ICI, erectile response, peak systolic velocity, end diastolic volume, cavernosal artery diameter, the presence of plaques) and the initial and follow up dose of ICI Trimix (per unit, each 1 ml has 100 units) was recorded. We categorized patients into two groups based on priapism development. Group 1: consisted of patients who responded well to Trimix injections without priapism episodes (n = 218), group 2: patients who developed priapism either during the in-office PDU/ICI or while using Trimix at home (n = 15). The T test was used to compare each of the different clinical and PDU variables between the 2 groups.

Results
Table 1 demonstrates the baseline clinical characteristics of the entire cohort. 51.9% of patients were hypertensive, 17.2% were diabetic, 76.9% underwent radical prostatectomy or cystoprostatectomy, 24.5% had history radiation therapy and 18% had androgen deprivation therapy. When comparing the two groups, patients who developed priapism (group 2) had lower Hemoglobin A1c (HbA1c), (P = 0.011), lower cavernosal arteries end diastolic volume (EDV), (P = 0.003) and higher Trimix dose during the PDU procedure, (P &lt; 0.001), Table 2.

Conclusions
There are several predictors that were identified to correlate with development of priapism after use of ICI for ED. These include a lower HbA1c, lower EDV and higher Trimix dose during the PDU. By understanding these predictors, men's health physicians can be better equipped to manage ED with Trimix therapy and potentially reduce the risk of prolonged erection/priapism and its negative consequences. Further studies are needed to investigate any other possible predictors.

Disclosure
No.