Key points

Introduction

Priapism is defined as a full or partial erection that continues more than 4 hours beyond sexual stimulation and orgasm or is unrelated to sexual stimulation. Two broad, cause-derived categories guide management strategies. Ischemic (or veno-occlusive, low-flow) priapism warrants immediate intervention, whereas nonischemic (arterial, high-flow) priapism does not.

The erection in ischemic priapism is marked by profound, unremitting venous congestion that creates a compartment syndrome that ultimately prevents arterial inflow. Corporal blood gas studies have shown that ischemia and acidosis can occur within 6 hours of a priapism episode. Although erectile dysfunction rates approach 25% to 50% in patients with ischemic priapism, those with an episode greater than 24 hours typically face invasive shunt procedures, prolonged pain, and a 90% risk of subsequent erectile dysfunction.

The delayed sequelae of prolonged ischemia and acidosis frequently result in corporal fibrosis and penile shortening. Therefore, placement of the prosthesis in the acute setting is easier than delayed implantation. In patients with prolonged episodes of acute priapism, early implantation alleviates ischemic pain, allows the patient to resume sexual function sooner, and prevents the corporal scarring and shortening that makes subsequent prosthesis implantation difficult.

Introduction

Priapism is defined as a full or partial erection that continues more than 4 hours beyond sexual stimulation and orgasm or is unrelated to sexual stimulation. Two broad, cause-derived categories guide management strategies. Ischemic (or veno-occlusive, low-flow) priapism warrants immediate intervention, whereas nonischemic (arterial, high-flow) priapism does not.

The erection in ischemic priapism is marked by profound, unremitting venous congestion that creates a compartment syndrome that ultimately prevents arterial inflow. Corporal blood gas studies have shown that ischemia and acidosis can occur within 6 hours of a priapism episode. Although erectile dysfunction rates approach 25% to 50% in patients with ischemic priapism, those with an episode greater than 24 hours typically face invasive shunt procedures, prolonged pain, and a 90% risk of subsequent erectile dysfunction.

The delayed sequelae of prolonged ischemia and acidosis frequently result in corporal fibrosis and penile shortening. Therefore, placement of the prosthesis in the acute setting is easier than delayed implantation. In patients with prolonged episodes of acute priapism, early implantation alleviates ischemic pain, allows the patient to resume sexual function sooner, and prevents the corporal scarring and shortening that makes subsequent prosthesis implantation difficult.

Patient evaluation overview

When the persistent erection is accompanied by pain, ischemia should be suspected, because nonischemic priapism is generally not painful. A careful history may reveal predisposing factors, such as sickle cell hemoglobinopathy (or other hematologic conditions), neurologic disease, or pharmacologic reasons for the erection. Pelvic and perineal trauma can result in nonischemic priapism.

On physical examination, inspection and palpation reveal rigid corpora cavernosa, with soft corpus spongiosum and glans tissues. Laboratory testing can detect hematologic abnormalities, and in African American men without a known history of sickle cell disease, a sickle cell preparation and hemoglobin electrophoresis should be obtained. Corporal blood gas analysis can differentiate ischemic from nonischemic priapism, with ischemic blood revealing acidosis, hypercarbia, and hypoxia.

Pharmacologic treatment options

Initial therapy involves corporal aspiration, irrigation, and injection of α-adrenergic agonists, with the intent of relaxing the smooth muscle and re-establishing arterial inflow, venous drainage, and subsequent detumescence. This approach is highly effective, especially in cases of less than 24 hours’ duration.

When priapism is not effectively treated in a prompt manner, irreversible fibrosis develops. Thus, up to 25% of patients with priapism experience chronic erectile dysfunction. Irreversible fibrotic changes occurring after 48 hours stem from smooth muscle cell necrosis within the corpora cavernosa and subsequent transformation into fibroblastlike cells. The corporal scarring is irreversible and leads to permanent erectile dysfunction that is refractory to medical management and renders delayed surgical placement of a penile prosthesis technically challenging.

Surgical treatment options

For priapism that is refractory to medical management, corpora-spongiosal shunts are usually performed. There is no general consensus on the management of refractory or delayed cases of ischemic priapism. Immediate insertion of a penile prosthesis is an emerging, effective therapeutic concept in the urological armamentarium.

Historical perspective on prosthetic implantation

Most initial reports and series for prosthetic insertion for priapism have involved patients with sickle cell trait, delayed and/or recurrent presentation, or failure of previous shunt surgeries. Early reports describe the use of semirigid devices, which were theoretically superior to inflatable devices due to the need to overcome significant corporal rigidity. Surgeons encounter technical challenges with the procedure because of the fibrosis, necessitating corporal tunneling and excavation, with high risk for further interventions.

Early implantation

In 1996, Monga and colleagues introduced the concept of managing potency and recurrence in sickle cell patients with “early” implantation. Rees and colleagues effectively managed 8 patients with ischemic priapism of a mean duration of 91 hours with the insertion of either malleable or inflatable devices. Four (50%) of the patients had failed previous shunts. Only one failure was reported, with penile deformity caused by compression of an inflatable cylinder by fibrosis, leading the authors to conclude that a semirigid device was best used as a temporizing measure, thereby preserving penile length and corporal patency until an inflatable device can be offered.