Introduction

A pseudoaneurysm is the disruption of an arterial wall, causing a saccular outpouching that communicates with the vessel lumen, contained only by the outermost layer of the arterial wall, the tunica adventitia. Trauma is one of the main etiologies for pseudoaneurysm formation, and early recognition is key as pseudoaneurysm rupture is associated with high morbidity and mortality.¹ Historically, surgical repair was required, but with advancements in image-guided endovascular interventions, angioembolization has become an established treatment for symptomatic pseudoaneurysm, particularly when the donor artery is accessible and amenable to occlusion. Off-target risks of embolization include inadvertent damage to end-organ structures. This is especially relevant for the very small caliber of the arterial supply to the external genitalia, with concern for significant morbidity from end artery ischemic necrosis.

These risks can be mitigated with selective embolization of the distal-most artery using microcatheters and microwires. There is literature supporting the superselective arterial embolization of the cavernosal artery of the penis with the use of microcoils, which has been demonstrated to be safe and effective while minimizing the risk of long-term erectile dysfunction.^2-4 We present the case of a superselective embolization of a ruptured dorsal penile artery branch pseudoaneurysm following a ballistic injury to the perineum.

Case Report

Materials/methods

A 19-year-old male with recent history of a single gunshot wound to the right flank with exit wound in the left anterior thigh status post–flexible sigmoidoscopy and suprapubic tube placement presented 3 weeks later with acute onset urethral bleeding and dizziness. CT angiography of the pelvis showed a 14- × 4- × 6-cm perineal hematoma with intramuscular extension into the right gluteal and left adductor musculature, and a 2.2-cm pseudoaneurysm with surrounding hematoma near the left penile shaft suspicious for bulbar artery involvement (Figure 1). He was found to have severe hemorrhagic anemia with a hemoglobin of 5.7 g/dL and blood transfusions were initiated. Given the severe anemia and active bleeding, he was taken to the interventional radiology suite for angiogram and selective embolization of a suspected ruptured pseudoaneurysm.

Results/intervention

Interventional radiology proceeded with a selective angiogram of the left internal iliac artery, which demonstrated a large pseudoaneurysm off the left internal pudendal/common penile artery, likely the bulbourethral artery. Using a microcatheter and microwire, the left internal pudendal and dorsal penile arteries were sequentially catheterized. Selective angiogram of the terminal branch of the left dorsal penile artery was performed, confirming active extravasation of a bleeding pseudoaneurysm (Figure 2). Coil embolization was performed with 2-mm Boston Scientific Interlock microcoils with cessation of contrast filling of the pseudoaneurysm on subsequent ipsilateral and contralateral internal iliac angiograms (Figure 3).

Given the possibility of a superinfected hematoma/perineal abscess given the patient’s significant leukocytosis of 37.74 × 10³/mL, the decision was made to perform perineal surgical exploration and contrast studies, which revealed the large ischioanal fossa cavity filled with hematoma. This was evacuated and a Penrose drain was placed. Urology subsequently performed a cystoscopy, which demonstrated a large proximal bulbar urethral cavity with significant blood products and discontinuity with the proximal urethra. Open suprapubic tube exchange was performed given the lack of successful irrigation of the existing suprapubic tube. Antegrade cystoscopy revealed normal prostatic urethra with verumontanum as a visible landmark; the membranous urethra appeared to be relatively intact just distal to the verumontanum, but the proximal bulbar urethra was blind ending, having been obliterated by the gunshot and subsequent healing. The patient remained stable and was able to be discharged home with outpatient follow-up and planning for eventual repair of the bulbar urethral stricture.

Discussion

Timely intervention is crucial for both asymptomatic cases of pseudoaneurysm, to prevent rupture which increases morbidity and mortality, and for symptomatic cases to alleviate associated symptoms and risks.¹ Symptoms such as perineal swelling, generalized pain, and hematuria are indicative of vascular injury. Elective therapy and rapid intervention should be strongly considered in such cases to prevent further deterioration, rupture, and life-threatening hemorrhage.

The precedent for angioembolization in genitourinary trauma is well established for both blunt and penetrating renal trauma, with a notable paradigm shift from surgical exploration to angioembolization, even in the setting of high-grade renal trauma (ie, grade 4-5), with resulting reduced rate of nephrectomy.⁵ Pelvic angioembolization has been demonstrated as a safe, rapid, and effective intervention for hemorrhage associated with high-impact pelvic injuries in hemodynamically stable and, more recently, unstable patients.⁶ Angioembolization avoids the need for invasive surgical access to the pelvis, which is complicated by deeply situated blood vessels that may be avulsed by the mechanism of injury and are prone to torrential hemorrhage upon disruption of the pelvic hematoma during surgical exploration. Angioembolization circumvents the complexity of suture ligation and minimizes the exacerbation of hemorrhage and anatomical insult common with alternative exploratory procedures. Angioembolization may be used as one component of a multistage intervention, first employing an endovascular technique to control hemorrhage and then a later surgical exploration to assess the abdominopelvic viscera.

Regarding technique, percutaneous and endovascular embolization are 2 widely utilized approaches for pseudoaneurysm treatment. In this particular instance, percutaneous embolization was not considered due to the specific location and tiny caliber of the pseudoaneurysm, highlighting the importance of selecting the most appropriate technique based on patient-specific anatomical considerations.

By avoiding nonspecific embolization of the internal iliac arteries and opting for super-selective arterial embolization of the common penile artery, risks associated with nontarget embolization, including arteriogenic erectile dysfunction from occlusion of the cavernosal artery, may be significantly reduced.

This case demonstrates the successful application of super-selective arterial embolization for the emergent treatment of a ruptured deep pseudoaneurysm originating from the dorsal penile artery. This approach ensured precise targeting, achieving effective hemostasis while preserving surrounding vasculature and end-organ perfusion, all while mitigating risks of massive pelvic hemorrhage from open surgical exploration.

Conclusion

Our case highlights the powerful role of interventional radiology–guided angioembolization of a symptomatic pseudoaneurysm of a branch of the penile artery. The success of super-selective arterial embolization in this case emphasizes its potential as a timely and efficacious treatment modality. Careful consideration regarding embolization techniques and minimization of nontarget embolization reduces long-term complications.