Canadian Journal of Cardiology 32 (2016) 136.e1e136.e3 www.onlinecjc.ca
Case Report
Autologous Pericardial Reconstruction of Ruptured Salmonella Mycotic Aortic Arch Aneurysm John H. Landau, MD,a A. Dave Nagpal, MD, FRCSC,b and Michael W.A. Chu, MD, FRCSCb a
Division of Vascular Surgery, Western University, London, Ontario, Canada
b
Division of Cardiac Surgery, Western University, London, Ontario, Canada
ABSTRACT
RESUM E
The primary goals of surgery for mycotic thoracic aortic aneurysms include control of sepsis, radical debridement of infected tissue, anatomic or extra-anatomic aortic reconstruction, and prevention of recurrent infection. Patients with Salmonella aortitis are a challenging subgroup of patients with aggressive infection and very poor prognosis, because bacterial eradication is difficult and risk of recurrent infection is high. We report the successful surgical management of a patient who presented with a ruptured Salmonella aortic arch aneurysm with extensive debridement and near circumferential autologous pericardial patch reconstruction of the aortic arch.
vrismes mycotique de Les principaux objectifs de la chirurgie des ane bridement de tous l’aorte thoracique sont la maîtrise de la sepsie, le de s, la reconstruction anatomique ou extra-anatomique les tissus infecte vention des infections re cidivantes. Les patients de l’aorte et la pre souffrant d’une aortite à salmonelles constituent un sous-groupe s à des infections virulentes et un très complexe de patients expose radication bacte rienne est difficile et que mauvais pronostic puisque l’e cidivantes est e leve . Nous rapportons la prise le risque d’infections re ussie d’un patient ayant pre sente une rupture en charge chirurgicale re vrisme à salmonelles de l’arc aortique qui a subi un de bridement d’ane tendu et une reconstruction autologue quasi circonfe rentielle de l’arc e ricardique. aortique par pièce pe
Salmonella aortitis is a rare but aggressive clinical entity that is associated with bacterial seeding of an atherosclerotic aortic plaque and often results in aneurysm formation.1 Mortality with medical therapy alone approaches nearly 100% with most patients dying of aortic aneurysm rupture. Aggressive surgical treatment can reduce the mortality rate to 40%; however, many patients still develop late anastomotic pseudoaneurysm formation or graft reinfection. We report the successful treatment of a patient with a ruptured Salmonella aortic arch aneurysm that was treated with arch resection and autologous pericardial patch reconstruction.
She also complained of chest pain and further investigation revealed a mild increase in troponin level and ischemic electrocardiogram changes. Computed tomography (CT) scan revealed an 8 9 mm outpouching on the inferior aspect of the aortic arch at the level of the left subclavian artery with associated fat stranding and gas collection. There were no other mycotic aortic aneurysms identified and coronary angiography demonstrated high-grade triple vessel disease. Echocardiography demonstrated left ventricular segmental wall motion abnormalities (ejection fraction 45%-50%) with no evidence of infectious endocarditis. Antibiotic therapy was initiated; however, a repeat CT scan 3 days later showed an increase in aneurysm size and gas collection with signs concerning for impending rupture, which prompted urgent surgery. The surgery was performed via a median sternotomy with right axillary artery cannulation. During cooling to 22 C, 3-vessel coronary artery bypass was performed. Under circulatory arrest with continuous antegrade cerebral perfusion, the densely inflamed aortic arch was circumferentially mobilized revealing excessive periaortic phlegmon, with multiple pockets of purulent fluid drained from the aortopulmonary window. Tissue and fluid cultures were eventually positive for Salmonella Enteritidis. The mycotic aneurysm extended along the lesser curve of the arch from the mid ascending aorta to the proximal descending
Case A 61-year-old diabetic woman presented with a 2-week history of malaise, weakness, abdominal pain, and diarrhea. She also reported a 40 kg weight loss and travel to Cuba 3 months previously. She was found to be in diabetic ketoacidosis, with blood cultures positive for Salmonella Enteritidis. Received for publication July 1, 2015. Accepted August 9, 2015. Corresponding author: Dr Michael W.A. Chu, B6-106 University Hospital, LHSC, 339 Windermere Rd, London, Ontario N6A 5A5, Canada. Tel.: þ1-519-663-3593; fax: þ1-519-663-3595. E-mail:
[email protected] See page 136.e3 for disclosure information.
http://dx.doi.org/10.1016/j.cjca.2015.08.013 0828-282X/Ó 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
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Figure 1. (A) Aortic arch after debridement. (B) Ulcerated aortic wall resected from the lesser curve of the aortic arch. (C) Autologous pericardial patch repair of the aortic arch. AA, aortic arch; DtA, descending thoracic aorta; GV, great vessels.
thoracic aorta, requiring en bloc resection. The extensive debridement, guided visually, included much of the anterior and posterior walls of the aortic arch, leaving an island of the head vessels with a ‘tongue’ of tissue to the descending aorta. Two large autologous pericardial patches were harvested, pretreated with glutaraldehyde, and used to reconstruct the aortic arch with the great vessels remaining in their anatomic position (Fig. 1). The patient was discharged home on postoperative day 13 with a course of intravenous tobramycin and ampicillin for a total of 6 months. As expected, she had left recurrent laryngeal nerve paralysis, which was treated with injection thyroplasty. At her 6-month follow-up, she was free of recurrent infection and a surveillance CT scan showed a stable repair with complete resolution of previous signs of infectious aortitis (Fig. 2).
Discussion Mycotic aortic arch aneurysms are almost uniformly fatal if left untreated, and surgical mortality has been reported to be as high as 65%.1 Complete surgical debridement is necessary to eradicate infections; however, the need to maintain adequate distal perfusion after reconstruction is paramount. In this case, the infected field was adjacent to many critical mediastinal structures and as such, we elected to perform anatomic reconstruction with autologous pericardium to minimize risk of graft infection.
General considerations for treatment include open vs endovascular intervention, in situ vs extra-anatomic repair, and synthetic vs biologic conduit. Although endovascular intervention has been explored for mycotic aortic aneurysms, secondary infection of stent grafts has shown high mortality and has not achieved widespread adoption.2 Extra-anatomic reconstruction is technically difficult to perform in the aortic arch, but ensures exclusion of the infected field and has been associated with some promising albeit inconsistent late outcomes.1 In situ reconstruction ensures antegrade, laminar flow-preserving native circulation, but requires wide debridement to eradicate infection.3 When considering conduit selection, synthetic material such as Dacron is affordable and readily available, but carries a potential for graft infection. Biologic materials, such as bovine pericardium or cryopreserved homografts, offer a decreased risk of postoperative infection.4 Autologous pericardium might offer the lowest risk of infection compared with commercially available biologic conduits while avoiding their associated costs. Pretreatment with glutaraldehyde improves the mechanical strength of the pericardium and reduces any possible residual bacterial contamination. Large patches of autologous pericardium can be safely harvested with little risk of complication. To date, a case report by Peniston and colleagues represents the only other case in the literature to our knowledge, to describe an autologous pericardial patch for repair of a mycotic aneurysm of the aortic arch.5 With this approach and a course of postoperative antibiotics, our patient has
Landau et al. Mycotic Arch Aneurysm
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Figure 2. (A) Preoperative CT scan showing a ruptured focal mycotic aneurysm of the aortic arch and (B) gas extending around the periaortic space. (C) Postoperative follow-up CT scan at 6 months showing intact arch reconstruction. CT, computed tomography.
shown excellent clinical and radiographic improvement at 6 months. Disclosures The authors have no conflicts of interest to disclose. References 1. Soravia-Dunand VA, Loo VG, Salit IE. Aortitis due to Salmonella: report of 10 cases and comprehensive review of the literature. Clin Infect Dis 1999;29:862-8.
2. Kan CD, Lee HL, Yang YJ. Outcome after endovascular stent graft treatment for mycotic aortic aneurysm: a systematic review. J Vasc Surg 2007;46:906-12. 3. Müller BT, Wegener OR, Grabitz K, et al. Mycotic aneuryms of the thoracic and abdominal aorta and iliac arteries: experience with anatomic and extra-anatomic repair in 33 cases. J Vasc Surg 2001;33:106-13. 4. Hsu RB, Lin FY. Surgery for infected aneurysm of the aortic arch. J Thorac Cardiovasc Surg 2007;134:1157-62. 5. Peniston C, Mahoney J, Panos A, Lichtenstein AV, Salerno TA. Mycotic aneurysm of the ascending thoracic aorta: Management with pericardial patch and bilateral pectoralis muscle flaps. J Thorac Cardiovasc Surg 1989;98:308-10.