Aorta-left renal vein fistula syndrome caused by rupture of a juxtarenal abdominal aortic aneurysm: novel pathologic mechanism for a unique clinical entity.

Spontaneous aorta-left renal vein fistula (ALRVF) caused by abdominal aortic aneurysm (AAA) is a rare form of intravascular aneurysm rupture. The literature series of ALRVF, updated here to 19 reported cases, demonstrates that patients with ALRVF present with a unique clinical syndrome characterized by abdominal or left flank pain (84%), a pulsatile abdominal mass (63%), abdominal bruit or murmur (63%), hematuria (100%), and nonfunction of the left kidney on functional imaging studies (100% of patients studied). Operative findings in ALRVF syndrome have included a large AAA (mean diameter 9.2 cm), with frank rupture in only three; in 17 of 19 patients (89%) the ALRVF was associated with a retroaortic left renal vein anomaly. The patient presented here had a large juxtarenal AAA with rupture into the left retroperitoneal space. The wide aneurysm neck and expanding hematoma created an avulsion of the second left lumbar vein from its junction with an anatomically normal (preaortic) left renal vein; the resulting renal vein tear allowed development of an arteriovenous communication that was responsible for the clinical presentation of ALRVF syndrome. The disease found here demonstrates a novel mechanism for the production of ALRVF syndrome in patients with juxtarenal AAA and otherwise normal pararenal venous anatomy.