Intraoperative diagnosis and treatment of massive pulmonary embolism complicating surgery on the abdominal aorta

Paradoxical pulmonary embolism with spontaneous aortocaval fistula

BACKGROUND

Paradoxical pulmonary embolisms are uncommon emergencies and can occur as a consequence of an aortocaval fistula due to unrecognized dislodgement of thrombus from aortic sac into pulmonary circulation. This study reviewed current literature and therapeutic options in this emergency condition requiring prompt management and repair.

METHODS

Literature was systematically searched for paradoxical pulmonary embolism associated with aortocaval rupture.

RESULTS

Eight published cases were identified. However, many other paradoxical pulmonary emboli could have remained undiagnosed due to challenging clinical presentation. Symptoms of high-output cardiac failure and respiratory distress in the presence of large aortoiliac aneurysm and venous hypertension are findings of a possible major abdominal arteriovenous fistula with paradoxical pulmonary embolism. Successful treatment depends on prevention of new embolism and proper management of perioperative hemodynamics and massive bleeding during fistula repair. Endovascular procedures have been recently used as useful tools in this field. Cava filter placement may be a first step to prevent further thrombus dislodgements during aortocaval repair. Immediate subsequent aortic stent-grafting can allow repair of aortocaval communication and exclusion of the abdominal aortic aneurysm from circulation with successful reversal of altered hemodynamic features. However, experience (especially in the long-term) is limited.

CONCLUSIONS

Paradoxical pulmonary embolism from aortocaval fistula represents an extremely rare but true clinical emergency with high fatality rate. Recent advances in diagnostic technology and endovascular techniques can substantially improve outcomes of the disease. Clinical competence in early detection and diagnosis is essential for appropriate emergent management.

Paradoxical pulmonary embolism secondary to aortocaval fistula: diagnosis by helical CT

Spontaneous aortocaval fistula is an unusual but well recognized complication of abdominal aortic aneurysm. Reports of aortocaval fistula as the source of pulmonary embolism are rare. We report a case of paradoxical pulmonary embolism secondary to an aortocaval fistula. The abdominal aortic aneurysm and the associated aortocaval fistula were well demonstrated on helical CT, leading to early diagnosis and prompt surgical treatment with good clinical outcome.

Case report: the demonstration of aortocaval fistulae by helical computed tomography

We report the helical computed tomography findings in two patients with spontaneous aortocaval fistula (ACF) complicating abdominal aortic aneurysm. The use of overlapping slices produced high quality multiplanar reformats which provided anatomical information about the likely site of the ACF and also the relationship of the renal arteries to the neck of the aneurysm.

Aortocaval fistula: a rare cause of paradoxical pulmonary embolism

An 83 year old woman died suddenly from a paradoxical pulmonary embolus which had originated in an abdominal aortic aneurysm and embolised via an aortocaval fistula. This lesion should be considered in the differential diagnosis of embolic disease.

Spontaneous aortocaval fistula--preoperative diagnosis and management

Spontaneous aortocaval fistula is an uncommon complication of an abdominal aortic aneurysm. This report details two cases of this condition presenting with symptoms attributable to arteriovenous shunting. Pain was not a prominent feature so that attention was not initially drawn to the abdomen. Diagnosis and management of the condition are discussed.