[Clinical studies of renal trauma]

A total of 70 patients with renal trauma were treated at the Department of Urology, Nara Medical University and Nara Prefectural Hospital, including Life-Saving Emergency center, from January 1982 to June 1993. They were between 3 and 79 years old (mean 30.0) and preponded to the younger generation. The main cause of injury was traffic accident in 46 cases (65.7%). According to the Classification of Renal Injury by the Japanese Association for the Surgery of Trauma in Japan, there were 31 cases (44.3%) of type I (subcapsular injury), 18 cases (25.7%) of type II (superficial injury), 15 cases (21.4%) of type III (deep injury), and 6 cases (8.6%) of type IV (pedicle injury). Surgical treatment was performed in 17 cases (24.2%). The major associated injuries were bone fracture in 32 cases (45.7%), lung injury in 17 cases (24.2%), and liver injury in 15 cases (21.4%). Furthermore, hydronephrosis and ureteral tumors were incidentally found in 4 and 1 patient during the course of treatment for renal trauma. Post-traumatic plasma renin activities (PRA) in types III and IV were significantly higher than those in types I and II. Hypertension developed in 1 case of types I and II and 4 cases of types III and IV. The mean level of PRA was significantly decreased 2 years after renal injury in both groups. We should bear in mind that renal trauma may be associated with other urological diseases such as hydronephrosis and urological malignancies, and post-traumatic PRA should be followed carefully.