Endovascular Stent Graft Treatment of a Traumatic Aortocaval Fistula Jimmy L. Waldrop, Jr., MD,1 Benjamin W. Dart IV, MD,1 and Donald E. Barker, MD, FACS, Chattanooga, Tennessee
Aortocaval fistula (ACF) is an infrequently reported sequela of trauma. Most ACF have been repaired via an open approach. During the past 10 years, there has been one reported case of spontaneous ACF and two cases of traumatic ACF repaired using an endovascular technique. We present a third case of traumatic ACF repaired with an endovascular stent graft. A 40-yearold male sustained two gunshot wounds to the right chest and one to the right upper abdomen. He was taken from the emergency department directly to the operating room, where an exploratory laparotomy was performed. Through-and-through injuries to the stomach and transverse colon were repaired primarily. Subsequently, the patient developed abdominal compartment syndrome. An urgent exploratory laparotomy was performed, revealing a nonbleeding hematoma on the posterior lateral surface of the right lobe of the liver, which was left undisturbed. Open abdominal management was instituted with vacuum pack closure. On the nineteenth hospital day, the patient again had a significant decrease in hematocrit. An aortogram was performed in order to evaluate the patient for intrahepatic arterial bleeding amenable to transcatheter embolization. There was no evidence of hepatic arterial bleeding. However, a supraceliac ACF was identified. The patient was taken to the operating room, and an AneuRx aortic extension cuff was advanced under fluoroscopy and deployed to cover the fistula. Completion angiography revealed total obliteration of the ACF and appropriate placement of the stent graft. Postoperatively, the patient was returned to the intensive care unit, where his hospital course was complicated by ventilator-associated pneumonia and sepsis. Repeat computed tomographic scanning 6 months and 1 year following this repair demonstrated patency of the graft without evidence of graft migration or aortocaval communication. Further research and experience are necessary with this technique regarding long-term outcome and technical aspects. In particular, the sizing problems associated with repair of acute traumatic ACF in emergency situations should be addressed. The endovascular approach provides an attractive and exciting alternative to traditional methods for repair of ACF.
Aortocaval fistulas (ACF) are rare. Spontaneous ACF from erosion of an aortic aneurysm into the vena cava account for the majority of cases. Traumatic and iatrogenic etiologies account for the remainder.1,2 Signs and symptoms of ACF vary depending on the size and location of the
Department of Surgery, University of Tennessee College of Medicine, Chattanooga Unit, Chattanooga, TN, USA. Correspondence to: Donald E. Barker, MD, FACS, Department of Surgery, University of Tennessee College of Medicine, Chattanooga Unit, 979 East Third Street, Suite 401, Chattanooga, TN 37403, USA, E-mail:
[email protected] Ann Vasc Surg 2005; 19: 562-565 DOI: 10.1007/s10016-005-5025-7 Ó Annals of Vascular Surgery Inc. Published online: June 30, 2005 562
fistula. Presenting findings may include congestive heart failure, pain, abdominal mass, or bruit; however, ACF can be completely asymptomatic and discovered incidentally.2,3 The time to diagnosis may vary from several days to several years.4 Once diagnosed, most ACF have been repaired by an open approach.2,5,6 Open repair has been associated with high operative blood loss and high mortality.7,8 During the past 10 years, endovascular repair of ACF has become feasible. Three cases of aortic aneurysm-associated ACF repaired by the endovascular approach have been reported.1,7,9 Parodi et al.8 reported two cases of traumatic ACF repaired by the endovascular technique. We present a third case of traumatic ACF repaired with an endovascular stent graft (Fig. 1).
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Fig. 1. Aortocaval fistula.
CASE REPORT A 40-year-old man presented to the emergency department at our level I trauma center after sustaining two gunshot wounds to his right chest and one to his upper abdomen. He was endotracheally intubated, and intravenous access was established. He had decreased breath sounds bilaterally, and bilateral closed tube thoracostomies were performed with 800 cc bloody output from the right thoracostomy tube. At emergency department admission, his heart rate was 96 beats per minute and blood pressure was 144/86 mm Hg and remained stable. He was taken from the emergency department directly to the operating room, where a celiotomy was performed. Through-and-through injuries to the stomach and transverse colon were repaired primarily. A left perirenal hematoma was explored, without identification of an active bleeding source. There was no evidence of direct hepatic injury or perihepatic bleeding. The remaining intra- and retroperitoneal structures appeared uninjured. Postoperatively, he had a persistent right pleural effusion, and an additional right thoracostomy tube was placed. Computed tomographic (CT) scan revealed a loculated right hemothorax and a new subcapsular hepatic hematoma. A right thoracotomy and decortication was performed. Five days later, the patient developed increased peak airway pressures and an intraabdominal pressure of 27 mm Hg. His hematocrit decreased from 30% to 24%. Abdominal compartment syndrome was diagnosed. Exploratory laparotomy was performed,
Case reports 563
Fig. 2. Aortocaval fistula after placement of stent graft.
revealing only a large subcapsular hepatic hematoma, which was left undisturbed. Open abdominal management was instituted. Subsequently, the patient had increasing abdominal distention, and a CT scan revealed an ACF at the T11/T12 level. Angiography confirmed the presence and location of the fistula. Aortic diameter, fistula size, and location of aortic branch vessels were determined by CT scan. Vascular surgery was consulted. The patient was taken to the operating room, and access to the vascular system was obtained by cutdown on the right femoral artery and percutaneous access to the left femoral artery. Subsequently, an AneuRxÒ (Medtronic, Minneapolis, MN) aortic extension cuff with a diameter of 28 mm and length of 3.5 cm was deployed in place to cover the fistula. Repeat angiography revealed complete obliteration of the ACF and appropriate placement of the stent graft (Fig. 2). There were no hemodynamic alterations associated with placement of the graft. Postplacement central venous pressure, heart rate, and blood pressure values were not appreciably different from preplacement values. Pneumonia and pulmonary sepsis complicated his postoperative course. Recurrent bleeding from his liver injury did not require surgical intervention. The endovascular graft was followed for evidence of infection by CT scans and blood cultures. He was weaned from mechanical ventilatory support, his open abdomen wound was skin-grafted, and he was discharged to a rehabilitation center and subsequently to home. He has had no evidence of recurrence of his ACF at 1 year postrepair.
564 Case reports
DISCUSSION The first reported case of an ACF was in 1831 by Syme. This was an ACF associated with a syphilitic aortic aneurysm.1 The first described traumatic ACF was by Bigger in 1944.10 In 1955, Cooley reported the first successful open repair of an ACF.11 Becker et al.12 reported the first endovascular repair of a subclavian arteriovenous fistula in 1991. This repair was a temporary measure until a more definitive open procedure could be performed. In 1999, Parodi et al.8 described the first permanent endovascular repair of an arteriovenous fistula. Since then, there have been three reported cases of aortic aneurysm-associated ACF repaired by the endovascular approach.1,7,9 Parodi et al.8 have reported two cases of traumatic ACF repaired by the endovascular technique. The etiology of ACF may be spontaneous, iatrogenic, or traumatic. Spontaneous ACF account for 80% of all cases. Of spontaneous ACF, 90% are the result of atherosclerotic aortic aneurysms that rupture into the vena cava. Other causes include syphilis, bacterial infection, Marfan syndrome, and Ehlers-Danlos syndrome.1,2 The remaining 20% of cases are the result of trauma and iatrogenic causes such as central line placement and intervertebral disk surgery.1,2 ACF account for 0.6-6% of all cases of arteriovenous fistula.7 The pathophysiology of ACF has been reviewed and well described by Alexander and Imbembo.2 The physiological changes are dependent upon the size of the fistula, volume of flow, caliber of vessels involved, proximity to the heart, duration of time that the fistula has been present, and history of cardiac disease. Common changes include increased venous volume and pressure, decreased peripheral vascular resistance, and increased stroke volume, heart rate, and cardiac output. The hyperdynamic changes and increased cardiac work lead to congestive heart failure. Decreased flow in the distal arterial circuit may lead to ischemia, and decreased renal blood flow may result in oliguria and azotemia. Common signs and symptoms include pain, a palpable mass, a bruit or thrill, signs of venous/ portal hypertension, and peripheral edema, cyanosis, or arterial insufficiency.2 However, traumatic ACF may have a more chronic and insidious nature, which may be due to their occurrence in younger patients with smaller fistulas.2 Common signs and symptoms may not be present for some time. In traumatic ACF, Jarstfer and Rich13 report that 8.5% of patients become symptomatic within 24 hr and 21.3% become symptomatic after 1 year.
Annals of Vascular Surgery
Open repair has been the mainstay of ACF treatment. Procedures such as quadruple ligation of the involved artery and vein, endoaneurysmorrhaphy, and transaortic fistula closure with prosthetic graft bypass have been performed.2,5,6 However, open repair has been associated with a mortality rate of 30% and significant morbidity including limb loss, gangrene, ischemia, caval thrombosis, pulmonary embolus, venous stasis, myocardial infarction, and severe bleeding from engorged retroperitoneal veins.1,2,8 In the past 10 years, endovascular repair of arteriovenous fistulas has become possible. Compared to the open approach, the endovascular approach is less invasive; has been associated with less pain, disability, and cost; and may allow for a reduction in morbidity and mortality.8 Endovascular repair of acute ACF may be complicated by difficulties in obtaining the properly sized stent in emergency situations. However, this should not be true with more elective cases. The indications for endovascular repair of ACF have not been fully defined. Candidates for endovascular repair of acute ACF include patients who are not suitable for open repair due to comorbid illness/trauma.14 Arterial anatomy around the site of injury must be evaluated to determine the feasibility of anchoring the stent graft.14,15 There must be adequate normal vessel proximal and distal to the site of injury for implantation of the device. The proximal neck should have a length of 10-15 mm, and angulation should be minimal.15 Branch vessels around the point of injury can be problematic. Techniques to deal with these include the use of devices with uncovered stents at the ends, embolization of branch vessels, revascularization, reimplantation, or simple covering of vessels with graft.15,16 Preoperative measurement of arterial diameter and length of the required graft for repair is essential and may limit use of endovascular grafts in the acute setting. However, many commercially available devices are versatile and can be used without extensive preoperative preparation.14 Ohki et al.17 have developed a versatile endovascular graft system, which can be modified intraoperatively and may eliminate some of these problems. To date, only two cases of repair of a traumatic ACF with an endovascularly placed stent graft have been reported.8 Our case is the third report. Our patient was multiply injured and critically ill. His ACF was diagnosed on the eighteenth day of his admission and had minimal hemodynamic effects, except for possibly contributing to his hepatic bleed and abdominal compartment syndrome. Since he was hemodynamically stable, there was time to
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obtain the appropriate aortic measurements and the appropriate stent graft prior to surgery. Avoiding a major open vascular procedure was obviously desirable in this multiply injured patient.
CONCLUSION The endovascular approach provides an attractive and exciting alternative to traditional methods for repair of ACF. REFERENCES 1. Lau LL, OÕReilly MJ, Johnston LC, Lee B. Endovascular stentgraft repair of primary aortocaval fistula with an abdominal aortoiliac aneurysm. J Vasc Surg 2001;33:425-428. 2. Alexander JJ, Imbembo AL. Aorta-vena cava fistula. Surgery 1989;105:1-12. 3. Khargi K, Bemelman WA, Voorwinde A, Keeman JN. Aortocaval fistulas. Neth. J. Surg. 1991;43:1-5. 4. Krishnasastry KV, Friedman SG, Deckoff SL, Doscher W. Traumatic juxtarenal aortocaval fistula and pseudoaneurysm. Ann. Vasc. Surg. 1990;4:378-380. 5. LinkerRW, Crawford FA,RittenburyMS,Barton M.Traumatic aortocaval fistula: case report. J. Trauma 1989;29:255-257. 6. Woolley DS, Spence RK. Aortocaval fistula treated by aortic exclusion. J. Vasc. Surg. 1995;22:639-642. 7. Umscheid T, Stelter WJ. Endovascular treatment of an aortic aneurysm ruptured into the inferior vena cava. J. Endovasc. Ther. 2000;7:31-35.
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8. Parodi JC, Schonholz C, Ferreira LM, Bergan J. Endovascular stent-graft treatment of traumatic arterial lesions. Ann. Vasc. Surg. 1999;13:121-129. 9. Beveridge CF, Pleass HC, Chamberlain J, Wyatt MG, Rose JD. Aortoiliac aneurysm with arteriocaval fistula treated by a bifuricated endovascular stent-graft. Cardiovasc. Intervent. Radiol. 1998;12:244-246. 10. Bigger IA.. Treatment of traumatic aneurysms and arteriovenous fistulas. Arch. Surg. 1944;49:170-179. 11. Cooley DA. Discussion of paper by Javid and Coll: resection of ruptured aneurysms of abdominal aorta. Ann. Surg. 1955;142:623. 12. Becker GJ, Benenati JF, Zemel G, et al. Percutaneous placement of a balloon-expandable intraluminal graft for lifethreatening subclavian arterial hemorrhage. J. Vasc. Interv. Radiol. 1991;2:225-229. 13. Jarstfer BS, Rich NM.. The challenge of arteriovenous fistula formation following disk surgery: a collective review. J. Trauma 1976;16:726-733. 14. Faries PL, Bernheim J, Kilaru S, Hollenbeck S, Clari D, Kent KC.. Selecting stent grafts for the endovascular treatment of abdominal aortic aneurysms. J. Cardiovasc. Surg. 2003;44:511-518. 15. Yano OJ, Marin M, Hollier L.. Patient selection for endovascular repair of aortoiliac aneurysms. Cardiovasc. Surg. 2000;8:340-349. 16. Criado FJ, Barnatan MF, Rizk Y, Clark NS, Wang CF.. Technical strategies to expand stent-graft applicability in the aortic arch and proximal descending thoracic aorta. J. Endovasc. Ther. 2002;9:II-32-II38. 17. Ohki T, Veith JF, Sanchez LA, et al. Endovascular graft repair of ruptured aortoiliac aneurysms. J. Am. Coll. Surg. 1999;189:102-113.