Aortocaval and iliac arteriovenous fistulas: Recognition and treatment

Abstract

Despite the well characterized physiologic effects of aortocaval or iliac arteriovenous fistulas, patients with such uncommon lesions may manifest a diverse array of symptoms, and diagnosis is often delayed or overlooked. To examine clinical features that facilitate recognition and allow successful repair, a 30-year experience with 20 such fistulas was reviewed. Fourteen fistulas were caused by aneurysm erosion, four followed iatrogenic injury during lumbar disk surgery, and two developed from abdominal gunshot wounds. The interval from presumed occurrence to diagnosis ranged from 3 hours to 8 years. The diagnosis was not recognized before surgery in five (25%) patients. Back pain (70%) was the most common symptom. The presence of a typical abdominal bruit (80%) was the most reliable physical finding, but its significance was occasionally overlooked or misinterpreted. Congestive heart failure was prominent in only seven (35%) patients. Severe lower extremity edema and mottling was the primary manifestation in eight cases, often causing initial confusion with venous thrombosis. Hematuria (5 patients) and oliguric renal failure (4 patients), both fully reversible after fistula repair, also caused diagnostic uncertainty. The mean preoperative cardiac output was 12.2 L/min, falling to 5.4 L/min with fistula repair. Mean blood loss was 5960 ml, supporting use of intraoperative autotransfusion. Two operative deaths (10%) occurred, both in patients not correctly diagnosed before surgery. Despite varied modes of presentation, prompt recognition and use of appropriate operative techniques should achieve successful repair.

Aneurisma ilíaco associado a fístula arteriovenosa

“…On the other hand, ruptured iliac aneurysms into the iliac-caval system has fewer symptoms; it is common for patients to remain weeks or months without being diagnosed until surgery. 16 In the present case, the patient remained for 7 weeks without a definitive diagnosis of AVF. Initial event was RLL edema with dyspnea.…”

“…12 Perioperative mortality is higher when AVF is not diagnosed. 16 Of the five deaths reported by Cinara et al (19.5% of cases), any had previous diagnosis of the fistula. 11 Those authors focus on the fact that aneurysm rupture into the vena cava or iliac vein has lower mortality than retroperitoneal, intraperitoneal rupture or into intestinal loops, when diagnosed before the surgery.…”

“…15 Congestive cardiac insufficiency is described between 11.5 and 28% of cases. 16 Increased venous pressure and compression of adjacent veins lead to lower limb edema. As a consequence of venous hypertension, there may be hematuria, renal insufficiency, scrotal edema and rectal bleeding.…”

Diagnosis of Aortic Aneurysm

“…Failure to auscultate the abdomen for a bruit is probably a key reason for non diagnosis before surgery (Brewster, Cambria et al 1991) and underscores the importance of routine auscultation of the abdomen in all patients with an aneurysm. In some instances the diagnosis may be missed despite detecting the abdominal bruit because of the inability to detect a palpable pulsatile abdominal mass, more so in those patients with isolated iliac aneurysms.…”

Preoperative Computed Tomographic Diagnosis of an Aortocaval Fistula Associated with Aneurysm of the Abdominal Aorta

“…1,2) The mortality rate of this condition is 25%-50% because controlling venous bleeding from the ACF is difficult.…”