[Cirsoid intrarenal arteriovenous malformation. Report of 2 cases, with special reference to review of 74 cases in Japan].

Two cases of cirsoid intrarenal arteriovenous malformation, in a female aged 67 and in a male aged 18, are reported and 74 cases of the same disease collected from the Japanese literature are reviewed. Several classifications have been proposed for the so-called congenital renal arteriovenous fistula. A truly congenital form of the lesion, however, is considered to be cirsoid type and we collected only this type of arteriovenous malformation. The number of reported cases has been increasing annually. The age distribution ranged from 10 to 84 years old (mean: 38.1 years old); 49 were female and 19 male. Gross hematuria, bladder tamponade and flank pain, which can be called the triad of cirsoid intrarenal arteriovenous malformation accounted for 84.0% of the clinical symptoms, whereas cardiovascular signs and symptoms accounted for only 7.8%. The right kidney was most frequently diseased and the intrarenal lesions showed about the same distribution in the upper pole, in the middle region and in the lower pole. Pathogenetic and pathophysiologic aspects of the renal arteriovenous malformation were discussed. Renal angiography is the most helpful method for obtaining a definite diagnosis, while such findings on the intravenous pyelogram as the so-called cobble stone deformity are thought to be characteristics of the X-ray. For the treatment of cirsoid arteriovenous malformations, conservative therapies including administration of styptics were carried out in 13%, selective transcatheter embolization in 17% and surgical procedures in 70%. The recent number of transcatheter embolization has been increased to establish it as one of the distinct therapeutic methods for this disease. Among the operative methods, partial nephrectomy is now being used more than nephrectomy and 4 cases of ex vivo surgery have been reported recently in Japan.