Rigi10™ Malleable Penile Prosthesis
Also Known As
Priapism shunt, surgical decompression for priapism, cavernoglandular shunt, corporoglanular shunt, cavernosal shunt, corporo-spongiosal shunt, cavernosal-spongiosal shunt, Winter procedure, Ebbehoj procedure, Al-Ghorab procedure, T-shunt procedure, Quackels procedure, Grayhack procedure, penile shunt.
Definition
Shunt surgery for priapism refers to a group of surgical procedures designed to treat ischemic priapism, a persistent, often painful penile erection lasting more than four to six hours that is not associated with sexual stimulation and results from impaired blood outflow from the corpora cavernosa.¹⁻³ Ischemic priapism is a urologic emergency because prolonged lack of oxygenated blood flow can lead to corporal smooth muscle necrosis, fibrosis, and permanent erectile dysfunction.¹˒³˒⁵
Shunt surgery works by creating an artificial pathway, or shunt, to divert trapped, deoxygenated blood from the corpora cavernosa (the erectile chambers of the penis) to another part of the body with normal circulation, thereby relieving the erection and restoring normal blood flow and oxygenation to the penile tissues.¹˒³˒⁵ This helps to reduce intracavernosal pressure and prevent long-term complications such as erectile dysfunction.¹
These procedures are typically considered second-line treatment, employed when more conservative measures, such as corporal aspiration (drawing blood from the corpora) and intracavernosal injection of sympathomimetic drugs (medications that constrict blood vessels, like phenylephrine), have failed to achieve detumescence (subsidence of the erection).¹˒³˒⁵
Various types of shunt procedures exist and can be broadly categorized into distal (corporoglanular) and proximal shunts.⁵
- Distal Shunts: These create a connection between the corpora cavernosa and the glans penis (the head of the penis) or corpus spongiosum. Common distal shunt techniques include:
- Winter shunt: Uses a biopsy needle to create fistulas between the glans and each corpus cavernosum.⁵
- Ebbehoj shunt: Involves making small incisions in the glans and underlying tunica albuginea of the corpora.⁵
- Al-Ghorab shunt: An open surgical procedure that involves excising a segment of the distal tunica albuginea of the corpora cavernosa and creating a window to the glans.¹˒⁵
- T-shunt: A modification that can be performed percutaneously or as an open procedure, often involving tunneling, to create a robust corporoglanular connection.³˒⁵
- Proximal Shunts: These are more invasive and create a connection between the corpora cavernosa and a nearby vein (e.g., saphenous vein) or the corpus spongiosum more proximally. Examples include:
- Quackels shunt (corpora-spongiosum shunt): Connects the proximal corpora cavernosa to the corpus spongiosum.⁵
- Grayhack shunt (corpora-saphenous shunt): Anastomoses the corpus cavernosum to the saphenous vein.⁵
The primary purpose of shunt surgery is to urgently resolve ischemic priapism to preserve erectile tissue and prevent the severe complication of erectile dysfunction.¹˒³
Clinical Context
Shunt surgery is indicated for ischemic priapism (also known as low-flow or veno-occlusive priapism) that is refractory to first-line treatments.¹˒³˒⁵ First-line treatments typically involve aspiration of blood from the corpora cavernosa, often combined with irrigation and intracavernosal injection of sympathomimetic agents (e.g., phenylephrine) to induce detumescence.¹˒³ Ischemic priapism is characterized by a rigid, painful erection, with little or no cavernous arterial inflow, leading to a hypoxic and acidotic environment within the corpora cavernosa.³ If left untreated, or if treatment is significantly delayed (e.g., beyond 24-48 hours), it can result in irreversible corporal smooth muscle damage, fibrosis, and permanent erectile dysfunction.¹˒³˒⁵
Patient Selection Criteria: Patients are candidates for shunt surgery if they have: * A confirmed diagnosis of ischemic priapism (based on clinical presentation, penile blood gas analysis showing hypoxia, acidosis, and glucopenia).³ * Failure of conservative management, including adequate trials of aspiration and intracavernosal sympathomimetic injections, to resolve the priapism.¹˒³˒⁵ * Priapism duration is a critical factor. While shunting is a second-line option, prolonged priapism (e.g., >24-36 hours) significantly increases the likelihood of requiring a shunt and the risk of subsequent erectile dysfunction. Some studies suggest that patients with priapism duration exceeding 24 hours, or those with a history of prior priapism episodes, are at higher risk of needing a surgical shunt.⁵
Surgical Procedures: The choice of shunt procedure depends on the surgeon’s experience, the patient’s condition, and the duration of priapism. Distal shunts (corporoglanular) are generally preferred as the initial surgical approach due to their relative simplicity and lower morbidity compared to proximal shunts.⁵ * Distal shunts (e.g., Winter, Ebbehoj, Al-Ghorab, T-shunt) create a direct communication between the tip of the corpora cavernosa and the glans penis, allowing the stagnant blood to drain into the glanular (spongiosal) circulation.¹˒³˒⁵ The Al-Ghorab and T-shunt procedures are often favored for their effectiveness in creating a durable shunt.³˒⁵ * Proximal shunts (e.g., Quackels, Grayhack) are typically reserved for cases where distal shunts have failed or are not feasible. These are more complex procedures, creating a connection between the corpora cavernosa and the corpus spongiosum more proximally, or to a systemic vein like the saphenous vein.²˒⁵
The surgery is usually performed under general, spinal, or regional anesthesia.¹
Expected Outcomes: * The immediate goal of shunt surgery is to achieve penile detumescence and restore normal circulation to the corpora cavernosa, thereby relieving pain and preventing further ischemic damage.¹˒³ * Success rates for achieving detumescence vary depending on the shunt type and duration of priapism, but distal shunts like the Al-Ghorab or T-shunt generally have good success in resolving the erection.¹˒⁵ * Erectile Function: The most significant long-term concern is the preservation of erectile function. Unfortunately, even with successful detumescence, erectile dysfunction is a common sequela of ischemic priapism, particularly if the priapism was prolonged before intervention.¹˒²˒⁵ Factors associated with poorer erectile function outcomes include longer duration of priapism before treatment (especially >48 hours), the development of corporal fibrosis, and the necessity of a surgical shunt itself (as it often indicates more severe or prolonged ischemia).¹˒⁵ An older review reported an overall potency rate of 61% after shunt operations, but outcomes are highly dependent on the timeliness of intervention and severity of the initial ischemic event.² More recent studies emphasize that delayed management significantly impacts erectile function.¹ * Complications: Potential complications of shunt surgery include infection, bleeding, urethral injury, glans numbness or injury, recurrent priapism if the shunt closes prematurely, and the development of high-flow priapism (an iatrogenic arterio-cavernosal fistula).⁴˒⁵ Corporeal fibrosis and erectile dysfunction remain the most significant long-term complications related to the underlying ischemic event itself.¹
Early intervention is paramount in the management of ischemic priapism to maximize the chances of preserving erectile function.¹˒³˒⁵