The effect of a surgically created shunt between the corpus cavernosum penis and corpus spongiosum penis of stallions on erectile and ejaculatory function

OBJECTIVE: To evaluate the effect of a shunt created between the corpus cavernosum penis (CCP) and corpus spongiosum penis (CSP) on erectile and ejaculatory function of normal stallions and to verify persistence of the shunt. STUDY DESIGN: The capability of stallions to develop an erection and to ejaculate was evaluated before and after creation of a corporeal shunt. Persistence of the shunt was determined by dye injection into the CCP at necropsy. ANIMALS: Six stallions. METHODS: A CCP-CSP shunt was created in five stallions. Semen was collected before and 4 to 14 weeks after surgery, before the horses were euthanatized. Dye was injected into the CCP to determine persistence of the shunt. Dye was also injected into the CCP of a control stallion. RESULTS: All stallions had normal erectile and ejaculatory function before and after surgery. Dye, injected into the CCP, entered the CSP in three of five treated stallions, demonstrating persistence of the shunt, whereas in two stallions, dye was found only in the CCP, indicating closure of the shunt. No dye was detected in the CSP of the control stallion. CONCLUSIONS: Creation of a corporeal shunt does not interfere with normal erection and ejaculation of stallions. Shunt closure is not necessary for stallions to retain normal erectile and ejaculatory function. CLINICAL RELEVANCE: Failure of a stallion affected by priapism to achieve normal erection or to ejaculate after creation of a corporeal shunt would likely be because of damage to corporeal tissue than from an effect of the shunt.