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Aortoenteric Fistula Treated With Endovascular Aortic Stent-Graft and Bilateral Chimney Stent-Grafts to Renal Arteries
Aortoenteric Fistula Treated With Endovascular Aortic Stent-Graft and Bilateral Chimney Stent-Grafts to Renal Arteries Glenn Wei Leong Tan,1 Daniel Wong,2 Sundeep Punamiya,2 Bien Peng Tan,2 Charles Vu,3 Brenda Ang,4 David Foo,5 and Kok Hoong Chia,1 Singapore, Singapore
We report a patient with secondary aortoenteric fistula (AEF) presenting with a rectal bleeding. The patient had multiple comorbidities, precluding major open vascular surgery. We opted to perform a two-stage procedure, where an endovascular stent-graft was first deployed to exclude the AEF from the systemic circulation. As the AEF was at the proximal anastomosis of the previous Dacron graft and close to the renal artery ostia, chimney stent-grafts were placed in both renal arteries to maintain their patency. The second stage of the procedure involved a laparotomy to repair the defect in the duodenum to prevent further contamination from bowel contents.
Aortoenteric fistula (AEF) is defined as an abnormal communication between the aorta and a portion of the gastrointestinal tract. It can occur either de novo as primary AEF or after abdominal aortic surgery as secondary AEF. This typically presents with intermittent self-limiting bleeding from the gastrointestinal tract, so-called herald bleed, before life-threatening massive exsanguination occurs. Primary AEFs are rare, with a reported incidence of 0.04% to 0.07%,1,2 whereas the more common secondary AEFs occur after 0.36% to 1.6% of all aortic operations.3,4 If left untreated, this condition
1 Vascular Surgery Service, Department of General Surgery, Tan Tock Seng Hospital, Singapore. 2 Interventional Radiology Service, Department of Radiology, Tan Tock Seng Hospital, Singapore. 3
Division of Medicine, Department of Gastroenterology, Tan Tock Seng Hospital, Singapore. 4 Division of Medicine, Department of Infectious Disease, Tan Tock Seng Hospital, Singapore.
almost certainly results in mortality, prompting the surgeon into providing early intervention. Traditional management of AEFs includes open laparotomy, aortic ligation, debridement of infected tissue and explantation of infected graft, and extraanatomical bypass or in situ bypass with homografts or antibiotic-impregnated grafts. However, most of these patients are poor surgical candidates, resulting in perioperative mortality exceeding 50% in earlier series.5e8 But, in a more recent series by Bergqvist and Bjork, the overall mortality in this systematic review was 34%, reflecting an improved outcome.9 The poor survival from this condition has prompted some to explore less-invasive endovascular methods for treating AEFs, with more than 50 patients having undergone these procedures in the past decade.10,11 We describe a case of secondary AEF managed with endovascular stent-graft and chimney stent-grafts to maintain patency of the renal arteries, and we believe that our institution is the first to report this technique.
5 Division of Medicine, Department of Cardiology, Tan Tock Seng Hospital, Singapore.
Correspondence to: Glenn Wei Leong Tan, MB ChB, MMed (Surgery), FRCSEd (Gen), Department of General Surgery, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore G3 7RH, Singapore; E-mail: [email protected] Ann Vasc Surg 2012; 26: 422.e13e422.e16 DOI: 10.1016/j.avsg.2011.07.018 Ó Annals of Vascular Surgery Inc. Published online: January 27, 2012
CASE REPORT A 79-year-old gentleman with a history of open repair of a 6-cm infrarenal abdominal aortic aneurysm (AAA) presented with a single episode of per-rectal bleeding. In 2003, he had an elective open AAA repair with a bifurcated Dacron graft, as he also had concomitant bilateral 422.e13
422.e14 Case reports
common iliac aneurysmal disease. His comorbidities include ischemic heart disease requiring coronary artery bypass surgery in 1986, sick sinus syndrome requiring a permanent pacemaker, and hypertension. He was transferred to the gastroenterology department in our institution after initial resuscitation in another hospital. His hemoglobin level was found to be 9.6 g/dL (baseline hemoglobin was 11 g/dL), and blood transfusion was instituted. His white blood cell count on admission was 13.0 109/L, with a neutrophilia of 80%. Gastroscopy and colonoscopy performed 3 months earlier were unremarkable, except for colonic polyps and hemorrhoids, which were treated endoscopically. In view of the history of AAA repair, immediate suspicion for AEF during the current admission prompted an urgent computed tomographic aortogram. The scan revealed an anterior outpouching of the aorta suspicious for an AEF at the proximal anastomosis of the previous AAA repair in direct contact with the third part of the duodenum (Fig. 1). The left iliac limb of the Dacron graft was found to be occluded, but the patient was asymptomatic. He was started on intravenous ceftriaxone and metronidazole. Blood cultures performed did not reveal any bacteremia. As the patient was elderly with multiple comorbidities, it was thought that major open surgery requiring crossclamping of the aorta was not suitable. A two-stage procedure, with endovascular aortic stent-graft insertion, followed by laparotomy for debridement and to close the bowel defect, was devised. The right and left renal arteries were only 13 mm and 18 mm, respectively, proximal to the AEF. As there was doubt about the integrity of the neck around the fistula itself, the operators believed there was a need for a longer landing zone, which would cover the ostia of the renal arteries. To maintain patency of the renal arteries, it was decided that Chimney stent-grafts will be used. Surgical exposure of the right common femoral artery was performed, and an 8-F sheath was inserted. Both brachial arteries were accessed percutaneously with 6-F sheaths. Both renal arteries were cannulated with Rosen guidewires from the brachial arteries. Atrium’s (Atrium Medical Corporation, Hudson, NH) 6 24 mm stent-grafts were advanced into each renal artery. Cook Medical’s aorto-uni-iliac device (32 108 12 mm) was delivered through a 20-F sheath over Lunderquist wire into the previous Dacron graft up to the level of the superior mesenteric artery origin. The aorto-uni-iliac device was deployed simultaneously along with the stent-grafts in the renal arteries with the aid of molding balloons to achieve optimal placement (Fig. 2). A further iliac limb extension (18 54 12 mm) was deployed to ensure that the distal anastomosis of the right limb of the previous Dacron graft from the first repair was covered. Final check angiogram revealed no endoleaks and good flow of contrast into the superior mesenteric and renal arteries. The patient underwent laparotomy for closure of the enteric defect 6 days later. Kocher maneuver was performed to mobilize the duodenum. The duodenalejejunal
Annals of Vascular Surgery
Fig. 1. Computed tomographic scan of aortoenteric fistula demonstrating outpouching of aorta with possible communication to duodenum anteriorly.
Fig. 2. Simultaneous balloon molding of stents after deployment. flexure was dissected off the aorta without spillage of enteric contents. Some Prolene sutures from the previous surgery were encountered, which caused the duodenum to be adhered to the old Dacron graft. The unhealthy cuff of duodenum was excised, revealing the old Dacron graft and a small portion of stent-graft, and the defect closed primarily in two layers in a transverse manner to avoid stenosing the duodenum. Unhealthy tissue around the AEF was debrided. The operative field was lavaged with chlorhexidine and gentamicin wash and resorbable gentamicin-impregnated collagen (Collatamp G), and plug of omentum was interposed between the aorta and duodenalejejunal flexure. (Figs. 3 and 4). Tissue cultures did not grow any organisms.
Vol. 26, No. 3, April 2012
Fig. 3. Duodenalejejunal adhered onto aorta.
Case reports 422.e15
flexure
and
duodenum
Fig. 4. Duodenal defect repaired and breach in aneurysm sac with Dacron graft exposed. Gastrografin meal was performed 12 days after laparotomy and did not show any leak or stenosis in the duodenum. The patient was started on long-term prophylactic bactrim (sulfamethoxazole and trimethoprim) to provide suppression of potential sepsis arising from any occult residual infected tissue in the surgical field. He remains well 15 months after surgery, with no worsening renal function, clinical evidence of sepsis, or gastrointestinal bleeding. Computed tomographic scans performed 2 weeks and 7 months after the surgery revealed patency of the chimney stent-grafts and no migration or endoleaks.
DISCUSSION Endovascular repair of AEFs is increasingly being deployed in recent times owing to less-invasive nature of the procedure and minimal physiologic stress to the patient. However, endovascular repairs are limited by factors such as anatomic location of the fistula in relation to important aortic branches
and nature and virulence of infection. Endovascular repair may not be suitable if important visceral vessels, such as renal arteries, superior mesenteric artery, or celiac artery, have to be sacrificed. Patients with gross, uncontained, purulent intra-abdominal infection or bacteremia consisting of multiresistant organisms should also be excluded from endovascular treatment.12 Our patient had no obvious clinical or radiological evidence of overwhelming sepsis, but, unfortunately, he had a challenging anatomy, where the AEF was sited at the proximal anastomosis of the previous Dacron graft repair, which was in close relation to the renal arteries. As the patient was in danger of exsanguination from the AEF, custommade fenestrated stent-grafts, which require a significant amount of time for production by the manufacturer, were unsuitable. It was decided to use chimney stents deployed parallel to the main aortic stent-graft, protruding proximally, to preserve flow to the renal arteries. This made it possible to use standard off-the-shelf stent-grafts to treat lesions with inadequate fixation zones, providing an alternative to fenestrated stent-grafts in urgent cases, in aneurysms with challenging neck morphology, and for reconstituting an aortic side-branch unintentionally compromised during endovascular repair.13 The chimney stent used is a balloon-expandable covered stent-graft, as this provides strong radial force to withstand the pressure exerted by the endovascular aneurysm repair device and also reduces risk of endoleaks.14 This particular choice of stent-graft has also got a low profile, which allowed delivery through percutaneous brachial artery puncture. We believe that this is the first case of AEF treated with endovascular stent-graft and chimney stents to maintain patency of renal arteries that may otherwise be compromised by the main body of the stent-graft. As the stent-graft could still potentially be exposed to gut flora, repair of the enteric fistula, together with debridement of the surrounding contaminated tissue and surgical closure of the enteric defect, was performed to eradicate any residual infection and reduce the risk of colonization of the endovascular stent-graft. To reduce the risk of recurrence of AEF and graft infection, omentum was interposed between the aorta and repaired duodenum8 and gentamicin-impregnated collagen was placed in the surgical field,15 with both methods previously described as adjuncts in graft infections. Although cultures from the AEF did not grow any organisms, it was decided to start the patient on lifelong antibiotic therapy for suppression of sepsis, which has been advocated by some authors in the
422.e16 Case reports
literature,16,17 although results from long-term outcome of this practice is equivocal.10,11 The technique of chimney stent-grafts is appealing, especially when faced with surgically unfit patients with complex anatomy. However, its durability and overall benefit remain questionable, especially in healthy patients who can tolerate definitive surgical repair, when the role of endovascular therapy may be viewed as a bridge to definitive surgical repair. Endovascular stent-graft repair of AEF is associated with a high incidence of recurrent infection or bleeding, but it may be the only option for this subgroup of medically challenging patients with multiple comorbidities.
CONCLUSIONS Our case confirms that endovascular aortic stentgraft repair and chimney stent-grafts for the important side-branches are feasible in the management of AEF with challenging anatomy.
The authors thank Dr Rahul Sheth for his invaluable input. They also acknowledge the help rendered by Tan Tock Seng Hospital library services (Ms Cecilia James and Ms Norina Hamid) for the provision of reference materials.
REFERENCES 1. Saers SJ, Scheltinga MR. Primary aorto-enteric fistula. Br J Surg 2005;92:143e52. 2. van Olffen TB, Knippenberg LH, van der Vliet JA, Lastdrager WB. Primary aorto-enteric fistula: report of six cases. Cardiovasc Surg 2002;20:551e4.
Annals of Vascular Surgery
3. Champion MC, Sullivan N, Coles JV, et al. Aortoenteric fistula. Incidence, presentation recognition, and management. Ann Surg 1982;195:314e7. 4. Peck JJ, Eidemiller LR. Aortoenteric fistulas. Arch Surg 1992;127:1191e3. 5. Bergqvist D. Aortoenteric fistula. Review of a vascular emergency. Acta Chir Scand 1987;153:81e6. 6. Montgomery RS, Wilson SE. The surgical management of aortoenteric fistulas. Surg Clin North Am 1996;76:1147e57. 7. Dorigo W, Pulli R, Azas L, et al. Early and long term results of conventional surgical treatment of aortoenteric fistula. Eur J Vasc Endovasc Surg 2003;26:512e8. 8. Oderich GS, Bower TC, Cherry KJ Jr, et al. Evolution from axillofemoral to in situ prosthetic reconstruction for the treatment of aortic graft infections at a single centre. J Vasc Surg 2006;43:1166e74. 9. Bergqvist D, Bjork M. Secondary arterioenteric fistulationda systematic literature analysis. Eur J Vasc Endovasc Surg 2009;37:31e42. 10. Kakkos SK, Papadoulas S, Tsolakis IA. Endovascular management of arterioenteric fistulas: a systemic review and metaanalysis of the literature. J Endovasc Ther 2011;18:66e77. 11. Antoniou GA, Koutsias S, Antoniou SA, et al. Outcome after endovascular stent graft repair of aortoenteric fistula: a systematic review. J Vasc Surg 2009;49:782e9. 12. Gonzalez-Fajardo JA, Gutierrez V, Martin-Pedrosa M, et al. Endovascular repair in the presence of aortic infection. Ann Vasc Surg 2005;19:94e8. 13. Ohrlander T, Sonesson B, Ivancev K, et al. The chimney graft: a technique for preserving or rescuing aortic branch vessels in stent-graft sealing zones. J Endovasc Ther 2008;15:427e32. 14. Donas PD, Torsello G, Austermann M, et al. Use of abdominal chimney grafts is feasible and safe: short term results. J Endovasc Ther 2010;17:589e93. 15. Holdsworth J. Treatment of infective and potentially infective complications of vascular bypass grafting using gentamicin with collagen sponge. Ann R Coll Surg Engl 1999;81:166e70. 16. Burks JA, Faries PL, Gravereaux EC, et al. Endovascular repair of bleeding aortoenteric fistulas: a 5 year experience. J Vasc Surg 2001;34:1055e9. 17. Baril DT, Carroccio A, Ellozy SH, et al. Evolving strategies for the treatment of aortoenteric fistulas. J Vasc Surg 2006;44: 205e7.
We report a patient with secondary aortoenteric fistula (AEF) presenting with a rectal bleeding. The patient had multiple comorbidities, precluding major open vascular surgery. We opted to perform a two-stage procedure, where an endovascular stent-graft was first deployed to exclude the AEF from the systemic circulation. As the AEF was at the proximal anastomosis of the previous Dacron graft and close to the renal artery ostia, chimney stent-grafts were placed in both renal arteries to maintain their patency. The second stage of the procedure involved a laparotomy to repair the defect in the duodenum to prevent further contamination from bowel contents.
Aortoenteric fistula (AEF) is defined as an abnormal communication between the aorta and a portion of the gastrointestinal tract. It can occur either de novo as primary AEF or after abdominal aortic surgery as secondary AEF. This typically presents with intermittent self-limiting bleeding from the gastrointestinal tract, so-called herald bleed, before life-threatening massive exsanguination occurs. Primary AEFs are rare, with a reported incidence of 0.04% to 0.07%,1,2 whereas the more common secondary AEFs occur after 0.36% to 1.6% of all aortic operations.3,4 If left untreated, this condition
1 Vascular Surgery Service, Department of General Surgery, Tan Tock Seng Hospital, Singapore. 2 Interventional Radiology Service, Department of Radiology, Tan Tock Seng Hospital, Singapore. 3
Division of Medicine, Department of Gastroenterology, Tan Tock Seng Hospital, Singapore. 4 Division of Medicine, Department of Infectious Disease, Tan Tock Seng Hospital, Singapore.
almost certainly results in mortality, prompting the surgeon into providing early intervention. Traditional management of AEFs includes open laparotomy, aortic ligation, debridement of infected tissue and explantation of infected graft, and extraanatomical bypass or in situ bypass with homografts or antibiotic-impregnated grafts. However, most of these patients are poor surgical candidates, resulting in perioperative mortality exceeding 50% in earlier series.5e8 But, in a more recent series by Bergqvist and Bjork, the overall mortality in this systematic review was 34%, reflecting an improved outcome.9 The poor survival from this condition has prompted some to explore less-invasive endovascular methods for treating AEFs, with more than 50 patients having undergone these procedures in the past decade.10,11 We describe a case of secondary AEF managed with endovascular stent-graft and chimney stent-grafts to maintain patency of the renal arteries, and we believe that our institution is the first to report this technique.
5 Division of Medicine, Department of Cardiology, Tan Tock Seng Hospital, Singapore.
Correspondence to: Glenn Wei Leong Tan, MB ChB, MMed (Surgery), FRCSEd (Gen), Department of General Surgery, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore G3 7RH, Singapore; E-mail: [email protected] Ann Vasc Surg 2012; 26: 422.e13e422.e16 DOI: 10.1016/j.avsg.2011.07.018 Ó Annals of Vascular Surgery Inc. Published online: January 27, 2012
CASE REPORT A 79-year-old gentleman with a history of open repair of a 6-cm infrarenal abdominal aortic aneurysm (AAA) presented with a single episode of per-rectal bleeding. In 2003, he had an elective open AAA repair with a bifurcated Dacron graft, as he also had concomitant bilateral 422.e13
422.e14 Case reports
common iliac aneurysmal disease. His comorbidities include ischemic heart disease requiring coronary artery bypass surgery in 1986, sick sinus syndrome requiring a permanent pacemaker, and hypertension. He was transferred to the gastroenterology department in our institution after initial resuscitation in another hospital. His hemoglobin level was found to be 9.6 g/dL (baseline hemoglobin was 11 g/dL), and blood transfusion was instituted. His white blood cell count on admission was 13.0 109/L, with a neutrophilia of 80%. Gastroscopy and colonoscopy performed 3 months earlier were unremarkable, except for colonic polyps and hemorrhoids, which were treated endoscopically. In view of the history of AAA repair, immediate suspicion for AEF during the current admission prompted an urgent computed tomographic aortogram. The scan revealed an anterior outpouching of the aorta suspicious for an AEF at the proximal anastomosis of the previous AAA repair in direct contact with the third part of the duodenum (Fig. 1). The left iliac limb of the Dacron graft was found to be occluded, but the patient was asymptomatic. He was started on intravenous ceftriaxone and metronidazole. Blood cultures performed did not reveal any bacteremia. As the patient was elderly with multiple comorbidities, it was thought that major open surgery requiring crossclamping of the aorta was not suitable. A two-stage procedure, with endovascular aortic stent-graft insertion, followed by laparotomy for debridement and to close the bowel defect, was devised. The right and left renal arteries were only 13 mm and 18 mm, respectively, proximal to the AEF. As there was doubt about the integrity of the neck around the fistula itself, the operators believed there was a need for a longer landing zone, which would cover the ostia of the renal arteries. To maintain patency of the renal arteries, it was decided that Chimney stent-grafts will be used. Surgical exposure of the right common femoral artery was performed, and an 8-F sheath was inserted. Both brachial arteries were accessed percutaneously with 6-F sheaths. Both renal arteries were cannulated with Rosen guidewires from the brachial arteries. Atrium’s (Atrium Medical Corporation, Hudson, NH) 6 24 mm stent-grafts were advanced into each renal artery. Cook Medical’s aorto-uni-iliac device (32 108 12 mm) was delivered through a 20-F sheath over Lunderquist wire into the previous Dacron graft up to the level of the superior mesenteric artery origin. The aorto-uni-iliac device was deployed simultaneously along with the stent-grafts in the renal arteries with the aid of molding balloons to achieve optimal placement (Fig. 2). A further iliac limb extension (18 54 12 mm) was deployed to ensure that the distal anastomosis of the right limb of the previous Dacron graft from the first repair was covered. Final check angiogram revealed no endoleaks and good flow of contrast into the superior mesenteric and renal arteries. The patient underwent laparotomy for closure of the enteric defect 6 days later. Kocher maneuver was performed to mobilize the duodenum. The duodenalejejunal
Annals of Vascular Surgery
Fig. 1. Computed tomographic scan of aortoenteric fistula demonstrating outpouching of aorta with possible communication to duodenum anteriorly.
Fig. 2. Simultaneous balloon molding of stents after deployment. flexure was dissected off the aorta without spillage of enteric contents. Some Prolene sutures from the previous surgery were encountered, which caused the duodenum to be adhered to the old Dacron graft. The unhealthy cuff of duodenum was excised, revealing the old Dacron graft and a small portion of stent-graft, and the defect closed primarily in two layers in a transverse manner to avoid stenosing the duodenum. Unhealthy tissue around the AEF was debrided. The operative field was lavaged with chlorhexidine and gentamicin wash and resorbable gentamicin-impregnated collagen (Collatamp G), and plug of omentum was interposed between the aorta and duodenalejejunal flexure. (Figs. 3 and 4). Tissue cultures did not grow any organisms.
Vol. 26, No. 3, April 2012
Fig. 3. Duodenalejejunal adhered onto aorta.
Case reports 422.e15
flexure
and
duodenum
Fig. 4. Duodenal defect repaired and breach in aneurysm sac with Dacron graft exposed. Gastrografin meal was performed 12 days after laparotomy and did not show any leak or stenosis in the duodenum. The patient was started on long-term prophylactic bactrim (sulfamethoxazole and trimethoprim) to provide suppression of potential sepsis arising from any occult residual infected tissue in the surgical field. He remains well 15 months after surgery, with no worsening renal function, clinical evidence of sepsis, or gastrointestinal bleeding. Computed tomographic scans performed 2 weeks and 7 months after the surgery revealed patency of the chimney stent-grafts and no migration or endoleaks.
DISCUSSION Endovascular repair of AEFs is increasingly being deployed in recent times owing to less-invasive nature of the procedure and minimal physiologic stress to the patient. However, endovascular repairs are limited by factors such as anatomic location of the fistula in relation to important aortic branches
and nature and virulence of infection. Endovascular repair may not be suitable if important visceral vessels, such as renal arteries, superior mesenteric artery, or celiac artery, have to be sacrificed. Patients with gross, uncontained, purulent intra-abdominal infection or bacteremia consisting of multiresistant organisms should also be excluded from endovascular treatment.12 Our patient had no obvious clinical or radiological evidence of overwhelming sepsis, but, unfortunately, he had a challenging anatomy, where the AEF was sited at the proximal anastomosis of the previous Dacron graft repair, which was in close relation to the renal arteries. As the patient was in danger of exsanguination from the AEF, custommade fenestrated stent-grafts, which require a significant amount of time for production by the manufacturer, were unsuitable. It was decided to use chimney stents deployed parallel to the main aortic stent-graft, protruding proximally, to preserve flow to the renal arteries. This made it possible to use standard off-the-shelf stent-grafts to treat lesions with inadequate fixation zones, providing an alternative to fenestrated stent-grafts in urgent cases, in aneurysms with challenging neck morphology, and for reconstituting an aortic side-branch unintentionally compromised during endovascular repair.13 The chimney stent used is a balloon-expandable covered stent-graft, as this provides strong radial force to withstand the pressure exerted by the endovascular aneurysm repair device and also reduces risk of endoleaks.14 This particular choice of stent-graft has also got a low profile, which allowed delivery through percutaneous brachial artery puncture. We believe that this is the first case of AEF treated with endovascular stent-graft and chimney stents to maintain patency of renal arteries that may otherwise be compromised by the main body of the stent-graft. As the stent-graft could still potentially be exposed to gut flora, repair of the enteric fistula, together with debridement of the surrounding contaminated tissue and surgical closure of the enteric defect, was performed to eradicate any residual infection and reduce the risk of colonization of the endovascular stent-graft. To reduce the risk of recurrence of AEF and graft infection, omentum was interposed between the aorta and repaired duodenum8 and gentamicin-impregnated collagen was placed in the surgical field,15 with both methods previously described as adjuncts in graft infections. Although cultures from the AEF did not grow any organisms, it was decided to start the patient on lifelong antibiotic therapy for suppression of sepsis, which has been advocated by some authors in the
422.e16 Case reports
literature,16,17 although results from long-term outcome of this practice is equivocal.10,11 The technique of chimney stent-grafts is appealing, especially when faced with surgically unfit patients with complex anatomy. However, its durability and overall benefit remain questionable, especially in healthy patients who can tolerate definitive surgical repair, when the role of endovascular therapy may be viewed as a bridge to definitive surgical repair. Endovascular stent-graft repair of AEF is associated with a high incidence of recurrent infection or bleeding, but it may be the only option for this subgroup of medically challenging patients with multiple comorbidities.
CONCLUSIONS Our case confirms that endovascular aortic stentgraft repair and chimney stent-grafts for the important side-branches are feasible in the management of AEF with challenging anatomy.
The authors thank Dr Rahul Sheth for his invaluable input. They also acknowledge the help rendered by Tan Tock Seng Hospital library services (Ms Cecilia James and Ms Norina Hamid) for the provision of reference materials.
REFERENCES 1. Saers SJ, Scheltinga MR. Primary aorto-enteric fistula. Br J Surg 2005;92:143e52. 2. van Olffen TB, Knippenberg LH, van der Vliet JA, Lastdrager WB. Primary aorto-enteric fistula: report of six cases. Cardiovasc Surg 2002;20:551e4.
Annals of Vascular Surgery
3. Champion MC, Sullivan N, Coles JV, et al. Aortoenteric fistula. Incidence, presentation recognition, and management. Ann Surg 1982;195:314e7. 4. Peck JJ, Eidemiller LR. Aortoenteric fistulas. Arch Surg 1992;127:1191e3. 5. Bergqvist D. Aortoenteric fistula. Review of a vascular emergency. Acta Chir Scand 1987;153:81e6. 6. Montgomery RS, Wilson SE. The surgical management of aortoenteric fistulas. Surg Clin North Am 1996;76:1147e57. 7. Dorigo W, Pulli R, Azas L, et al. Early and long term results of conventional surgical treatment of aortoenteric fistula. Eur J Vasc Endovasc Surg 2003;26:512e8. 8. Oderich GS, Bower TC, Cherry KJ Jr, et al. Evolution from axillofemoral to in situ prosthetic reconstruction for the treatment of aortic graft infections at a single centre. J Vasc Surg 2006;43:1166e74. 9. Bergqvist D, Bjork M. Secondary arterioenteric fistulationda systematic literature analysis. Eur J Vasc Endovasc Surg 2009;37:31e42. 10. Kakkos SK, Papadoulas S, Tsolakis IA. Endovascular management of arterioenteric fistulas: a systemic review and metaanalysis of the literature. J Endovasc Ther 2011;18:66e77. 11. Antoniou GA, Koutsias S, Antoniou SA, et al. Outcome after endovascular stent graft repair of aortoenteric fistula: a systematic review. J Vasc Surg 2009;49:782e9. 12. Gonzalez-Fajardo JA, Gutierrez V, Martin-Pedrosa M, et al. Endovascular repair in the presence of aortic infection. Ann Vasc Surg 2005;19:94e8. 13. Ohrlander T, Sonesson B, Ivancev K, et al. The chimney graft: a technique for preserving or rescuing aortic branch vessels in stent-graft sealing zones. J Endovasc Ther 2008;15:427e32. 14. Donas PD, Torsello G, Austermann M, et al. Use of abdominal chimney grafts is feasible and safe: short term results. J Endovasc Ther 2010;17:589e93. 15. Holdsworth J. Treatment of infective and potentially infective complications of vascular bypass grafting using gentamicin with collagen sponge. Ann R Coll Surg Engl 1999;81:166e70. 16. Burks JA, Faries PL, Gravereaux EC, et al. Endovascular repair of bleeding aortoenteric fistulas: a 5 year experience. J Vasc Surg 2001;34:1055e9. 17. Baril DT, Carroccio A, Ellozy SH, et al. Evolving strategies for the treatment of aortoenteric fistulas. J Vasc Surg 2006;44: 205e7.