The Use of Transcatheter Superselective Embolization to Treat High Flow Priapism (Arteriocavernosal Fistula) Caused by Straddle Injury

Abstract

A28-year-old white male presented with persistent partial erections after an industrial straddle injury 5 months earlier. Immediately following the injury the patient experienced moderate perineal and penile pain with extensive bruising and a small laceration on the perineum. There was no evidence of urethral bleeding at the time of injury. The pain eventually subsided but the patient experienced chronic unwanted erections that were approximately 30% to 40% of full rigidity. The patient was unable to achieve an erection adequate for sexual penetration despite a normal libido. He reported no nocturnal erectile activity or urinary complaints. The patient had a supportive spouse. Otherwise all medical history was noncontributory. The patient was a well developed male with a moderate degree of anxiety. Genitourinary examination revealed moderate rigidity and slight tenderness along the left corporal body with a soft glans. The remaining physical examination was unremarkable. Results from the penile color duplex Doppler ultrasound study revealed 60 cm per second inflow in the left cavernosal artery with a corresponding 24 cm per second venous outflow. There was approximately 80% tumescence with 40% rigidity of the penis during the study. Based on history and Doppler study, diagnosis was left high flow priapism with a venous leakage component, and a pudendal arteriogram with possible embolization was scheduled. Superselective injection of the deep penile artery showed a deep penile arteriocavernosal fistula (part A of figure, arrow) causing massive opacification of the corporum cavernosum (part A of figure, arrowhead). To protect the glans penis against inadvertent embolization which could cause loss of sensitivity, a 0.014 platinum guide wire was temporarily placed into the dorsal penile artery (part B of figure, arrow) through a double lumen catheter while embolizing the fistula through the microcatheter advanced through the second lumen. Following superselective embolization of the fistula with AMICAR® enforced autologous blood clot, salutary occlusion of the fistula with no further opacification of the corpora was observed (part C of figure). Upon successful occlusion the penis became soft and rapidly collapsed. High flow priapism is a rare form that occurs with unregulated inflow of arterial blood into the corpora through an arteriocavernosal fistula, and is usually preceded by some form of perineal or penile trauma. Because there is perfusion of well oxygenated blood, high flow priapism (arterial priapism) is nonpainful, nonischemic and not an acute urological emergency. Thus, there is time for initial pharmacological therapeutic modalities. For high flow priapism refractory to this conservative management, radiological transcatheter superselective embolization has become the treatment of choice. 1 Selective embolization can be conducted using a variety of agents including autologous blood clot, metallic microcoils, gel foam and N-butyl cyanoacrylate. 2 Although there is a paucity of data, current theory suggests that embolization should be done with temporary occlusive agents to prevent irreversible changes in erectile function. Thus, autologous blood clots have become the mainstay of treatment for high flow priapism, with long-term followup rates of resolution at 100% and restoration of erectile function at 86%. 3