Persistent priapism is due to

Ans. is 'a' i.e., Sickle cell anemia Priapism is defined as erection lasting for > 4 hours. Low-flow priapism may be due to any of the following: An excessive release of neurotransmitters Blockage of draining venules (eg, mechanical interference in sickle cell crisis, leukemia, or excessive use of intravenous parenteral lipids) Paralysis of the intrinsic detumescence mechanism Prolonged relaxation of the intracavernous smooth muscles (most often caused by the use of exogenous smooth-muscle relaxants such as injectable intra-cavernosal prostaglandin E I) Prolonged low-flow priapism leads to a painful ischemic state, which can cause fibrosis of the corporeal smooth muscle and cavernosal aery thrombosis. The degree of ischemia is a function of the number of emissary veins involved and the duration of occlusion