作者单位:Christian Med Coll Vellore, Dept Anat, Vellore, Tamil Nadu, India[1]Christian Med Coll Vellore, Dept Biostat, Vellore, Tamil Nadu, India[2]Christian Med Coll Vellore, Dept Gen Surg Unit 1, Vellore, Tamil Nadu, India[3]Christian Med Coll Vellore, Dept Urol Unit 2, Vellore, Tamil Nadu, India[4]