Evaluation of Erectile Function in Renal Transplant Recipients

Abstract

RECTILE dysfunction describes the inability to achieve and maintain penile erection sufficient for coitus. Renal insufficiency is a chronic disease during which erectile function deteriorates, however, the etiology of this condition in such patients is multifactorial, involving organic and nonorganic (psychogenic) factors. 1 The condition may result from neuroendocrine disturbance, uremia, hypoxia, and atherosclerosis. 2 Neuroendocrine disturbance is often reversed by renal transplantation, but not by dialysis. 3 Psychological factors may also cause erectile dysfunction in dialysis patients, since approximately one fourth of these individuals are depressed at any given time. 4 Patients often regain potency after transplantation but in some cases, especially second transplantations, erectile function is adversely affected by interference with arterial blood flow. In this study, we evaluated the effect of renal transplantation on erectile function. PATIENTS AND METHODS Information on erectile function was collected by means of a questionnaire given to 65 men who were renal transplant recipients. The patients ranged in age from 20 to 57 years (mean 42.5 years). A second transplantation had been performed in four cases (6%). Posttransplantation follow-up ranged from 2 to 168 months (mean 72 months). A detailed medical history was taken and complete blood count, urinalysis, and a biochemical and endocrinologic blood analysis were routinely performed for all patients. A papaverine test, penile Doppler ultrasonography, cavernosometry, cavernosography, and pudendal angiography were done where indicated. For patients who had no erectile dysfunction before or after renal transplantation, the questionnaire and routine tests completed the evaluation. This group was considered to have experienced no change in erectile function due to renal transplantation. Similarly, no further tests were performed on patients who were afflicted with erectile dysfunction prior to renal transplantation but regained sexual function following transplantation. These patients were defined as the group with improved sexual function. On the other hand, patients with deteriorated erectile function after renal transplantation were evaluated in detail. All underwent a papaverine test involving intracavernous injection of 50 mg of papaverine and observation of response after 30 minutes. The group which experienced full erection after papaverine treatment (papaverine responders) was considered to have nonorganic (psychogenic) erectile dysfunction. Patients who did not respond to papaverine were further evaluated by penile Doppler ultrasonography for vasculogenic impotence. Papaverine-stimulated penile Doppler ultrasound was performed using a 7.5-MHz linear probe. Peak systolic velocities in the cavernous arteries were measured bilaterally. A peak systolic velocity of ,25 cm/s was considered as arterial insufficiency. Patients with arterial insufficiency underwent pudendal angiography, while those with normal penile Doppler ultrasound findings underwent dynamic infusion cavernosometry and cavernosography to assess for suspected veno-occlusive dysfunction. RESULTS Thirty-two patients (49.2%) experienced no alteration in erectile function before or after renal transplantation. Twelve patients (18.4%) said they regained erectile function after renal transplantation. Twenty-one patients (32.3%) with normal erectile function prior to transplantation during the hemodialysis period reported erectile dysfunction after the transplantation, constituting the group which was evaluated further. Seven of these patients were papaverine responders (nonorganic impotence) and benefited from antiserotoninergic treatment. All seven men received 150 mg/d trazodone initially, however, two patients who reported severe side effects with this drug were switched to sertraline at a dose of 50 mg/d. All patients in this group achieved erections sufficient for coitus within 3 months. In three patients, deterioration of erectile function was associated with hyperprolactinemia accompanied by a low testosterone level. A papaverine test was not performed in these cases. Oral testosterone replacement resulted in improved sexual function. Eleven of 21 patients who reported a deterioration in erectile function after transplantation did not respond to papaverine. These individuals were considered to have vasculogenic impotence. According to penile Doppler ultrasound, nine of these men had arterial insufficiency, while two had normal peak systolic velocities in their cavernous arteries, indicating no arterial insufficiency. These two patients underwent cavernosometry and cavernosography, which confirmed veno-occlusive dysfunction. They were treated with deep dorsal vein embolization using n-butyl cyanoacrylate, and regained satisfactory erections within 3 months, at which time control cavernosometry was normal.