- European Federation of Societies for Ultrasound in Medicine and Biology ~ Educating all for competence to practice ultrasound safely
EFSUMB General Assembly Meeting – 21 May 2025
May 13, 2025
HONORARY SECRETARY – Dr Hans Peter Weskott
May 27, 2025
SUBMIT YOUR CASE
EFSUMB invites submission of interesting cases for the website section 'Case of the Month'. All CoM submissions are eligible for selection for free registration at the next Euroson congress. Two cases that receive the most 'likes' in a year will receive free registration for the next EUROSON congress and the third most liked liked case will receive a cash prize of 100 EUR.
Pseudoaneurysms and arteriocavernosal fistulas in the corpora cavernosa and corpus spongiosum as post-traumatic penile injuries
Authors:
1. Álvarez Muñiz I; García Sánchez M; Muedra Jáñez R; Caveda Rodero P. (Hospital Universitario de Cabueñes, Gijón, Asturias, Spain).
2. In colaboration with: Menezes-Falcao Gomes-Marques A; Sanmartino González S; Montes García A; Vázquez Meizoso M. (Hospital Universitario Central de Asturias).
Fig 1. Sonographic Doppler ‘Ying-Yang’ appearance of the pseudoaneurysms located in the corpora covernosa (orange arrows) and corpora spongiosa (blue arrow) of the penis from a 20-year-old man caused by direct trauma which, as a consequence, presented a painless priapism that persisted for several weeks.
1Clinical History
A 20-year-old male presents with painless priapism lasting for several weeks following direct trauma. A penile ultrasound is requested.
2Diagnosis
Post-traumatic pseudoaneurysms and arteriocavernosal fistulas in the corpora cavernosa and corpus spongiosum.
3Discussion
BACKGROUND:
Pseudoaneurysms are vascular lesions resulting from a focal tear at a weakened segment of the vessel wall, allowing blood to leak into the surrounding tissues. Hence there is blood extravasation that is contained by the formation of a fibrous capsule and a neck that connects the pseudoaneurysm to the vessel. This neck allows a systolic flow towards the pseudoaneurysm and a diastolic flow towards the artery. Unlike true aneurysms they do not involve all three layers.
An arteriocavernosal fistula is a fistulous connection between an adjacent artery and the adjacent lacunar space.
• Usually sonography is the first step on the diagnosis.
Pseudoaneurysms appears as a fluid-filled, pulsatile mass adjacent to the affected artery and the hallmark feature is the "yin-yang" sign in Doppler study, which reflects the swirling blood flow within the pseudoaneurysm sac, due to the turbulence caused by the communication between the artery and the pseudoaneurysm cavity. The demonstration of a neck between the artery and the pseudoaneurysm is the key diagnostic feature and is manifested in the spectral Doppler study as a "to-and-fro" flow waveform, this represents anterograde flow during systole and retrograde flow during diastole. The arteriocavernosal fistula appears as an abnormal high-velocity connection between the artery and vein:
o Increased diastolic arterial flow.
o Abnormal arterial pulsatility of the vein (arterialization).
o Color bruit artifact due to turbulent flow.
Further imaging is required to confirm the diagnosis, characterisation and treatment:
• CT Angiography:
The pseudoaneurysm exhibits the same density as the vessel it originates from in all phases. In the non-contrast study, a rounded, low-attenuation structure adjacent to the artery can be identified. It appears hyperdense in the arterial phase, with a decrease in density (washout) in the venous phase and its morphology remains unchanged across different phases. Additionally, in most cases, it allows visualization of the communication neck with the originating vessel. In arteriovenous fistulas we would observe early venous filling in the arterial phase and delayed washout.
• Angiography:
Its main advantage lies in the high spatial resolution and the possibility of a real-time hemodynamic management, potentially becoming a therapeutic tool. Its main disadvantage is that it is an invasive technique. Currently, due to the development of other diagnostic techniques, primarily CT Angiography, its role is complementary or as a pre-procedural technique before an endovascular treatment.
CLINICAL PERSPECTIVE:
Priapism is a prolonged erection not caused by sexual stimulation. There are two types of priapism based on pathogenesis:
- ischemic, veno-occlusive or low-flow type
- nonischemic, arterial or high-flow type (our case): is usually secondary to a direct genitoperinal traumatism leading to an arteriocavernosal fistula/pseudoaneurysm. Erection is not as rigid and painful as in ischemic type and it doesn't require an emergent treatment.
THERAPY PLANNING:
Selective pelvic arteriography of both hypogastric arteries and superselective embolization of the pseudoaneurysms/ arteriocavernosal fistulas.
OUTCOME & PROGNOSIS:
The superselective embolization was successful, resulting in the resolution of the patient's priapism with no short-term complication. Some time after the procedure, the patient was reassessed at the Urology consultation, where he reported having normal, complete and painless erections.
Erectile dysfunction is the most significant complication, reported in about 39% with the use of permanent embolic agents and as few as 5% with temporary embolic agents.
Pseudoaneurysms are vascular lesions resulting from a focal tear at a weakened segment of the vessel wall, allowing blood to leak into the surrounding tissues. Hence there is blood extravasation that is contained by the formation of a fibrous capsule and a neck that connects the pseudoaneurysm to the vessel. This neck allows a systolic flow towards the pseudoaneurysm and a diastolic flow towards the artery. Unlike true aneurysms they do not involve all three layers.
An arteriocavernosal fistula is a fistulous connection between an adjacent artery and the adjacent lacunar space.
• Usually sonography is the first step on the diagnosis.
Pseudoaneurysms appears as a fluid-filled, pulsatile mass adjacent to the affected artery and the hallmark feature is the "yin-yang" sign in Doppler study, which reflects the swirling blood flow within the pseudoaneurysm sac, due to the turbulence caused by the communication between the artery and the pseudoaneurysm cavity. The demonstration of a neck between the artery and the pseudoaneurysm is the key diagnostic feature and is manifested in the spectral Doppler study as a "to-and-fro" flow waveform, this represents anterograde flow during systole and retrograde flow during diastole. The arteriocavernosal fistula appears as an abnormal high-velocity connection between the artery and vein:
o Increased diastolic arterial flow.
o Abnormal arterial pulsatility of the vein (arterialization).
o Color bruit artifact due to turbulent flow.
Further imaging is required to confirm the diagnosis, characterisation and treatment:
• CT Angiography:
The pseudoaneurysm exhibits the same density as the vessel it originates from in all phases. In the non-contrast study, a rounded, low-attenuation structure adjacent to the artery can be identified. It appears hyperdense in the arterial phase, with a decrease in density (washout) in the venous phase and its morphology remains unchanged across different phases. Additionally, in most cases, it allows visualization of the communication neck with the originating vessel. In arteriovenous fistulas we would observe early venous filling in the arterial phase and delayed washout.
• Angiography:
Its main advantage lies in the high spatial resolution and the possibility of a real-time hemodynamic management, potentially becoming a therapeutic tool. Its main disadvantage is that it is an invasive technique. Currently, due to the development of other diagnostic techniques, primarily CT Angiography, its role is complementary or as a pre-procedural technique before an endovascular treatment.
CLINICAL PERSPECTIVE:
Priapism is a prolonged erection not caused by sexual stimulation. There are two types of priapism based on pathogenesis:
- ischemic, veno-occlusive or low-flow type
- nonischemic, arterial or high-flow type (our case): is usually secondary to a direct genitoperinal traumatism leading to an arteriocavernosal fistula/pseudoaneurysm. Erection is not as rigid and painful as in ischemic type and it doesn't require an emergent treatment.
THERAPY PLANNING:
Selective pelvic arteriography of both hypogastric arteries and superselective embolization of the pseudoaneurysms/ arteriocavernosal fistulas.
OUTCOME & PROGNOSIS:
The superselective embolization was successful, resulting in the resolution of the patient's priapism with no short-term complication. Some time after the procedure, the patient was reassessed at the Urology consultation, where he reported having normal, complete and painless erections.
Erectile dysfunction is the most significant complication, reported in about 39% with the use of permanent embolic agents and as few as 5% with temporary embolic agents.
4Teaching Points
[1] After a direct trauma to the perineal area vascular complications could be found, such as pseudoaneurysms and arteriocavernous fistulas. We must be aware and acknowledge their typical radiological findings that allow us to differentiate them from other contained vascular lesions which is essential since the management and prognosis can be very different.
[2] Accurate diagnosis through imaging techniques like ultrasound and contrast-enhanced CT is essential for early detection and proper management. Posterior Angiography is usually necessary for a definitive diagnosis and therapeutic management.
[2] Accurate diagnosis through imaging techniques like ultrasound and contrast-enhanced CT is essential for early detection and proper management. Posterior Angiography is usually necessary for a definitive diagnosis and therapeutic management.
5References
[1.] Moreno Real, D. D., Aneiros Rosón, D. F., Aguado Linares, D. P., Brioso Díez, D. M., & De Araujo Martins-Romêo, D. (2022). La imagen del pseudoaneurisma; causas, complicaciones y diagnóstico diferencial. Seram, 1(1). https://www.piper.espacio-seram.com/index.php/seram/article/view/9533
[2.] Sueyoshi E, Sakamoto I, Nakashima K, et al. Visceral and Peripheral Arterial Pseudoaneurysm. AJR Am J Roentgenol 2005 Sep; 185: 741-9.
[3.] Saad NE,Saad WE,Davies MG,e tal.Pseudoaneurysms and the Role of Minimally Invasive Techniques in Their Management. Radiographics.2005 Oct;25Suppl1:S173-89
[2.] Sueyoshi E, Sakamoto I, Nakashima K, et al. Visceral and Peripheral Arterial Pseudoaneurysm. AJR Am J Roentgenol 2005 Sep; 185: 741-9.
[3.] Saad NE,Saad WE,Davies MG,e tal.Pseudoaneurysms and the Role of Minimally Invasive Techniques in Their Management. Radiographics.2005 Oct;25Suppl1:S173-89
