Pseudoaneurysm of Cavernosal Artery Presenting as Priapism in a 7-Year-Old Boy.

Priapism due to pseudoaneurysm of the cavernosal artery is very rare. Herein, we describe the magnetic resonance imaging and digital subtraction angiographic findings of pseudoaneurysm in the right corpus cavernosum in a 7-year-old boy who presented with pain in the penis and lower abdomen and priapism with an obscure history of trauma. This was managed by endovascular embolization of the aneurysm. One-year follow-up has shown him to be normal without any symptoms and normal erection. Copyright:

INTRODUCTION

The term “priapism” is derived from Priapus son of Aphrodite and the Greek God of fertility, who was depicted with a giant erect phallus and a symbol of male generative power.[1] Priapism is defined as a persistent erection of the penis or clitoris for more than 4 h that is not associated with sexual stimulation or desire. It has been known to adversely affect sexual function, quality of life, and physical wellness. Priapism is relatively rare but can occur in all age groups and is particularly common in patients with sickle cell disease. Priapism can be ischemic due to sickle cell disease and nonischemic or high flow due to pseudoaneurysm or arteriovenous (AV) fistula.

CASE REPORT

A 7-year-old boy presented with persistent erection of the penis with mild pain in the lower abdomen for 5 days. There was no definite history of trauma. Clinical examination revealed a swelling of 2 cm × 1 cm in the base of the penis with priapism. Complete blood picture and peripheral smears normal. There was no past history or family history of sickle cell disease/trait. Ultrasound showed a well-defined anechoic area in the right corpora cavernosa. On color Doppler, entire anechoic area showed increased color flow with arterial and venous spectral waveform. Magnetic resonance imaging showed a fairly well-defined area appearing hyperintense on T1 and hypointense on T2 with blooming on hemo (SWI - Susceptability weighted imaging sequence) measuring 17 mm × 7 mm × 9 mm (Antero-posterior × transverse × craino-caudal) noted in the midshaft of the right corpora cavernosa. No evidence of diffusion restriction was seen intact tunica albuginea. There was no evidence of soft tissue edema/inflammatory changes.

This was suggestive of AV fistula. The patient was suggested digital subtraction angiography (DSA) for further evaluation to rule out AV fistula or aneurysm.

DSA of the left pudendal artery confirmed pseudoaneurysm [Figure 1]. Left pudendal artery was embolized with poly vinyl alcohol particles (semipermanent embolic agent). Right pudendal artery injection was done and partially embolized with coils and gelfoam to prevent collateral filling of the aneurysm [Figure 2]. The swelling and priapism settled in 3 days. Postoperatively, he was well and pain free. At 1-year follow-up, he is completely normal with normal erection. He has been counseled regarding long-term follow-up.

Figure 1

Preembolization angiograms obtained from the left internal showing a small pseudoaneurysm in the penis

Figure 2

After selective embolization complete obliteration of the pseudoaneurysm is seen

DISCUSSION

Priapism or persistent erection can be due to low flow (ischemic) or high flow (nonischemic) or stuttering (recurrent and ischemic). The most common cause of low-flow/ischemic priapism is due to sickle cell disease or leukemia.[2] High-flow priapism is usually due to pseudoaneurysm or AV fistula and is rarely reported in children. It is a type of nonischemic priapism and presents with partial erection due to unregulated cavernous blood flow. Piesis sign (perineal compression resulting in penile detumescence which occurs after removal of perineal pressure) strongly suggests nonischemic priapism,[13] and this was elicited in our patient. It is important to differentiate between ischemic and high-flow priapism. Corbetta et al. have advocated routine corporal blood gas analysis to differentiate between high flow and low flow.[4] However, color Doppler has 100% sensitivity and specificity in experienced hands.[5] Hence, the clinical examination and Doppler were suggestive of high flow, and hence, corporal blood gas analysis was not done.

High-flow priapism results in increased flow into the corpora cavernosa. There is laceration of the cavernosal artery and its branches, leading to direct flow of blood into the cavernosal sinusoids and bypasses the regulatory helicine arterioles. During nocturnal tumescence, the clot formed during the injury is dislodged, resulting in delayed onset of priapism. The patient will usually present with painless persistent erections which are partially erect. The erection will happen usually 8 h after the traumatic event and is associated with mild pain.

In ischemic priapism, there will be severe pain and emergency treatment is necessary. It is important to differentiate between low flow and high flow as low flow is associated with a high morbidity and corporal fibrosis, loss, and erectile dysfunction. The history and clinical examination of partial erection involving tricorporal tissue and oxygenated blood on gas analysis are confirmatory.[6] Our patient had only mild pain, and there was a definite tender swelling with partial priapism with positive Piesis sign, suggesting a nonischemic cause. Other investigations such as complete blood count and peripheral smear were done to rule out leukemia and sickle cell disease and found to be normal. On taking a detailed history, there was a vague history of trauma. Color Doppler was diagnostic. Doppler shows low resistance, high-velocity / pseudoaneurysm is waveform. Moreover, fistula is identified as hypoechoic areas on the Doppler. DSA is confirmatory and the endovascular treatment can be done in the same sitting.

Fifty-five cases of high-flow priapism have been reported in children. Management options include conservative, mechanical, pharmacological, and radiological embolization or surgical ligation. The follow-up in children is only short term, and erectile dysfunction has not been evaluated reliably.[34]

Conservative treatment has been advocated with ice and site-specific compression, but this was not done in our patient. Pharmacological treatment such as intracorporeal injection of alpha adrenergic agonists or androgen is not advocated in children. Internal pudendal artery DSA and embolization have been the next line of management and have an overall success rate of 97%. Open surgical ligation of the internal pudendal artery should be done only in refractory cases as it has a high risk of erectile dysfunction[6] and is usually not necessary in children.

Multiple case reports and review articles have documented the use of different embolic agents including autologous clot, N-butyl-cyanoacrylate, gelfoam, and microcoils as the treatment for high-flow priapism.[7] We used poly vinyl alcohol/gelfoam as these are not permanent embolic agents and do not affect erection in the long term. Liquid embolic agents (medical alone) and permanent coils can also be used. However, chances of long-term ischemia and erectile dysfunction are present. We coiled the nonpenile branch of internal pudendal artery which was filling from the femoral artery (collateral circulation) to prevent recurrence after target artery embolization.

Priapism can be associated with erectile dysfunction, and very little literature is there in children. This boy does not have a recurrence of the aneurysm and has normal erection. He has been counseled regarding long-term follow-up.

CONCLUSION

High-flow priapism can present in children after trauma and can manifest after few hours to few days. It is usually associated with mild pain and partial erection, and color Doppler is diagnostic. It can be managed with ice packs and compression, and if not resolving, DSA and embolization should be performed. The child should be followed up for recurrence and erectile dysfunction.

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Conflicts of interest

There are no conflicts of interest.