Priapism color Doppler

Fig. 10.4a,b. High-flow priapism. Color Doppler appearance of the fistula before and after embolization, a Sagittal color Doppler image of the right crus shows extravasation of blood from the cavernosal artery (arrowheads), b Duplex Doppler ultrasound image obtained soon after angiography shows that the fistula is still patent, but reduced in size. The fistula closed spontaneously within 5 days... 

Fig. 18.7. Diffuse penile fibrosis following prolonged ischemic priapism. Color Doppler axial image obtained after prostaglandin injection shows small peripheral vessels feeding the outer portion of the corpora cavernosa. Cavernosal arteries are obliterated...

Urologic management of priapism requires assessment of corporal blood flow status with corporal aspirate, visual inspection by color and consistency or corporal blood, and blood gas analysis including pH, PO2, and PCO2. As described in Chapter 10, color Doppler ultrasonography is the imaging modality of choice (Berger et al. 2001). 

Low-flow priapism is suggested by finding low oxygen tension, high carbon dioxide and low pH in the blood gas analysis of the aspirate. When a high-flow state is suspected based on the bright red appearance or blood gas analysis of the corporal aspirate, color Doppler ultrasound is indicated to identify the arterial sinusoidal fistula. 

Color Doppler ultrasonography is currently considered the imaging modality of choice for the diagnosis of high-flow priapism since it is sensitive, non-invasive and widely available (Hakim et al. 1996 Bertolotto et al. 2003). No cavernosal injection of vasoactive drugs is required. 

Imaging Priapism The Diagnostic Role of Color Doppler US 81... 

During the follow-up of patients with high-llow priapism, we recommend color Doppler ultrasound 1-2 months after embolization to confirm the absence of recurrent fistula. Recanalization of the em-bolized cavernosal artery can be observed also when non-reabsorbable embolization material has been used (Savoca et al. 2004). In patients with erectile dysfunction, the study should be performed after in-tracavernosal prostaglandin injection to determine whether the functional impairment is caused by insufficient penile blood flow or not. 

In patients with low-flow priapism grey-scale and color Doppler ultrasonography provide useful information on the vascular status of the penis that can be of prognostic value and may influence the clinical or surgical management. 

During the follow-up of high-flow priapism, magnetic resonance imaging is able to document persistent closure or recanalization of the embolized cavernosal artery (Park et al. 2001). Color Doppler ultrasonography, however, usually provides enough clinically useful information in these patients. 

Bertolotto M, Quaia E, Mucelli EP et al (2003) Color Doppler imaging of posttraumatic priapism before and after selective embolization. Radiographics 23 495-503... 

Engin G, Tunaci M, Acunas B (1999) High-flow priapism due to cavernous artery pseudoaneurysm color Doppler sonography and magnetic resonance imaging findings. Eur Radiol 9 1698-1699... 

Metawea B, El-Nashar AR, Gad-Allah A et al (2005) Intracav-ernous papaverine/phentolamine-induced priapism can be accurately predicted with color Doppler ultrasonography. Urology 66 858-860... 

In patients with penile fracture, injury can occasionally involve the cavernosal tissue deeply, and associated cavernosal artery tear can be detected at color Doppler ultrasound (Fig. 12.7). High-flow priapism, however, does not develop in these patients, probably because of blood leakage from the albugineal tear. In our experience no attempt should be made during the operation to repair the arterial... 

The major problem of revascularization procedures is early or late closure of the anastomosis (Hauri 1998). Color Doppler ultrasonography is able to identify this complication and to detect blood flow changes that occur in the penile vessels. Rarer complications, such as aneurysmal dilatation of the anastomosis or priapism, can be evaluated as well (Bertolotto et al. 2005). 

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