This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
A 55 year old diabetic patient presented with impotence with history of failure to get erection after papaverine intracavernous injection. Colour doppler shows no. abnormality of aeries but shows mild venous run-off, Treatment of choice here would be 
Select and explain. 
A. Intracavernous injection of papaverine, B. Penile prosthetic implants, C. Vacuum constriction device, D. Psychotherapy
C: Vacuum constriction device
Answer: C: Vacuum constriction device 
Explanation: Ans. is 'c' i.e., Vacuum Constriction Device Vaccum Constriction devices it consists of a plastic cylinder connected to a vaccum generating source. After the penis is engorged by the negative pressure, a constricting ring is applied to the base to maintain the erection. To avoid injury the ring should not be left in place for longer than 30 min. - Such devices are suitable for those who fail to achieve an adequate erection with Intracavernous injection therapy and those with venous disorders of the penis. These devices are more acceptable in older men in a steady relationship than to young single men in search of a paner.