Surgical treatment of infected thoracic and abdominal aortic aneurysms

Ruptured tuberculous aneurysms of the abdominal aorta: Two case series

Background

Ruptured aneurysms secondary to the tuberculous infection of the aorta are a rare and life-threatening disease. We report a single-center experience of two patients with ruptured infrarenal tuberculous aneurysms.

Case presentation

We report 2 patients with ruptures of the tuberculous aneurysm. All patients had acute abdominal pain and were diagnosed by echography then CT scan preoperatively. The first patient (male, 50 years old) had a ruptured saccular aneurysm. The second patient (male, 43 years old) had a retroperitoneal contained rupture. All were treated by open prosthetic repair, by vascular surgeons. The two patients were well after operations. The diagnosis was confirmed by pathology examination. Antituberculous treatment was introduced after the operation.

Conclusions

Ruptured tuberculous aneurysms are rare but life-threatening. The diagnosis requires a high degree of suspicion. The treatment includes early diagnosis and emergent surgical intervention, extensive excision of infected field, aortic reconstruction, and prolonged antituberculous drug therapy.

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The tuberculous aortic aneurysm is a fatal condition if not early diagnosed and properly treated.

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The diagnosis requires a high degree of suspicion.

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Surgery is necessary for stenotic or aneurysmal lesions.

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The treatment should be a combination of surgery and antituberculous medication.

Surgical Pathology of Infected Aortic Aneurysm and Its Clinical Correlation

Pathology of infected aortic aneurysm and its clinical correlation have rarely been reported. Between 1995 and 2005, 48 patients with infected aortic aneurysm underwent in situ graft replacement. Twenty-five patients had a suprarenal and 23 patients had an infrarenal infection. The most common responsible pathogen was nontyphoid Salmonella in 32 patients (67%). During operation, gross pus was present in 26 patients (54%). On pathological examination, aortic atherosclerosis was present in all cases, acute suppurative inflammation was present in 31 patients (65%), and bacterial clumps were present in five patients (10%). Positive culture of the aneurysm wall was present in 14 patients (29%). There were 10 patients with prosthetic graft infection (21%) and 12 patients with aneurysm-related death (25%). Although statistically insignificant, local purulent infection with positive culture of the aneurysm wall, gross pus during operation, or acute suppurative inflammation on pathology tended to be associated with high risk of prosthetic graft infection and aneurysm-related death. In conclusion, infected aortic aneurysm occurred in patients with aortic atherosclerosis. On pathology, acute suppurative inflammation was present in the majority of cases but bacterial clumps were not commonly present. Local purulent infection tended to be associated with high risk of prosthetic graft infection and aneurysm-related death.

Salvage of Infected Prosthetic Grafts of the Great Vessels via Muscle Flap Reconstruction

OBJECTIVE

The infection of an aortic prosthetic graft presents a difficult challenge for surgeons. Conservative treatments such as debridement and antibiotic irrigation routinely fail, and patient survival rates are low. Literature has indicated that flap procedures often provide better treatment. In the present article, we report our experience utilizing pectoralis major muscle flaps, occasionally coupled with latissimus dorsi, rectus abdominis, and/or serratus anterior flaps, to wrap infected grafts and fill dead space.

PATIENTS

Between 1990 and 2004, 10 patients were brought to our attention with infections of prosthetic grafts of the great vessels (7 men and 3 women; mean age, 53 years). Infections in nine patients involved an ascending aortic graft, while one patient had an infected pulmonary artery graft.

DESIGN

Following diagnosis and exploration, an initial debridement is performed, followed by 48 h of antibiotic irrigation. A definitive muscle flap procedure is then utilized to fill dead space and clear the infection, followed by an appropriate antibiotic regimen.

RESULTS

The infections in all 10 patients were cleared using the muscle flap procedure. Two patients required a tapered-dose regimen of oral steroids, one of whom also required a secondary flap procedure due to the advanced stage of infection. Two other patients later died due to unrelated complications; however, autopsies revealed that operative sites had healed successfully. Patients were followed up for a period of 2 months to 2 years, and recurrence was not found.

CONCLUSIONS

Our outcomes suggest that muscle flap procedures, specifically utilizing the pectoralis major and regional muscles, should be kept in mind in the management of life-threatening infections of aortic grafts. Due to the limited number of patients in this study, we feel more research with a larger volume of cases is warranted.

Surgical treatment of infected aneurysms and pseudoaneurysms of the thoracic and abdominal aorta

BACKGROUND

To review the outcome of infected aneurysms and pseudoaneurysms of the thoracic and abdominal aorta treated in a major teaching hospital.

METHODS

Between December 1994 and January 2003, 13 infected aortic aneurysms and pseudoaneurysms (5 thoracic, 4 paravisceral, 4 infrarenal) in 10 consecutive patients were treated surgically. Aortic debridement with in situ reconstruction is our standard practice. Endovascular repair was offered to suitable patients with thoracic aortic involvement.

RESULTS

There were six men and four women with a mean age of 63 years. The commonest pathogen was Salmonella species, accounting for 50% of the cases. Aortic debridement with in situ revascularization was performed for six patients with visceral reconstruction in four of them. One patient with aortic bifurcation involvement and gross purulent infection had ligation and debridement followed by right axillobifemoral bypass. Four infected thoracic aortic pseudoaneurysms in three other patients underwent endovascular repair. There was no hospital death, limb loss, renal failure, or intestinal ischemia. There were two late deaths from sepsis and pneumonia at 3 months and 77 months after operation. Eight patients were alive after a mean follow-up of 36 months and no late graft infection was evident.

CONCLUSIONS

Surgical treatment for infected aortic aneurysms with in situ reconstruction is associated with favorable outcome and good long-term result. Endovascular repair has a potential role.

Aortobifemoral graft infection with mycobacterium tuberculosis: Treatment with abscess drainage, debridement, and long-term administration of antibiotic agents

Aortic graft infection with Mycobacterium tuberculosis is rare. We report a patient with a Dacron aortobifemoral prosthetic graft infection secondary to tuberculosis. The infection was successfully treated with surgical drainage without removal of the graft, and long-term antimycobacterial medications. A review of the literature contains only 1 other report of tuberculosis graft infection and treatment. We discuss a rare form of aortic graft infection from M tuberculosis and its treatment.

Infected aortic aneurysms: clinical outcome and risk factor analysis

PURPOSE

Infected aortic aneurysms are difficult to treat, and are associated with significant mortality. Hospital survival is poor in patients with severe aortic infection, Salmonella species infection, Staphylococcus aureus infection, aneurysm rupture, and suprarenal aneurysm location. We reviewed the clinical outcome in 46 patients with primary infected aortic aneurysms and identified clinical variables associated with prognosis.

METHODS

Data were collected by means of retrospective chart review. Univariate and multivariate logistic regression models were used for risk factor analysis.

RESULTS

Between August 1995 and March 2003, 48 patients with primary infected aortic aneurysms were treated at our hospitals. Two patients with negative culture results were excluded. Of the remaining 46 patients, 35 patients had aortic aneurysms infected with Salmonella species and 11 patients had aortic aneurysms infected with microorganisms other than Salmonella species. There were 20 suprarenal infections and 26 infrarenal infections. Surgical debridement and in situ graft replacement were performed in 35 patients, with an early mortality rate of 11%. The incidence of late prosthetic graft infection was 10%. The 90-day mortality rate in patients operated on was 0% for elective operation and 36% for nonelective operation (P =.006, Fisher exact test). Independent predictors of aneurysm-related death were advanced age, non-Salmonella infection, and no operation.

CONCLUSION

With timely surgical intervention and prolonged antibiotic treatment, in situ graft replacement provides an excellent outcome in patients with primary infected aortic aneurysms and elective operation. Mortality is still high in patients undergoing urgent operation. Advanced age, non-Salmonella infection, and no operation are major determinants of mortality.

Mycotic aneurysm of the descending thoracic aorta caused by Pseudomonas aeruginosa in a solid organ transplant recipient: case report and review

BACKGROUND

Pseudomonas aeruginosa is a rare cause of aortic mycotic aneurysms. Optimal treatment, including reconstructive graft material and appropriate length of antibiotic therapy, is being debated.

METHODS

We describe a 26-year-old kidney-pancreas recipient who developed an aneurysm of the descending thoracic aorta caused by P. aeruginosa.

RESULTS

After surgical debridement and cryopreserved allograft reconstruction, parenteral antibiotics were continued for 12 months, at which time the patient was converted to oral antibiotic therapy. Within 6 months, he redeveloped a thoracic aortic aneurysm, necessitating reoperation and lifelong parenteral antibiotic therapy.

CONCLUSION

Herein we review and discuss the relevant literature concerning surgical and antibiotic treatment of mycotic thoracic aneurysms.

Ruptured mycotic thoracoabdominal aortic aneurysms: a report of three cases and a systematic review

We report three cases of ruptured mycotic thoracoabdominal aortic aneurysms (TAAAS) and a review of the literature. Escherichia coli and Streptococcus pneumoniae (2 patients) were the responsible organisms. Surgical management consisted of wide debridement of necrotic tissue and in situ repair with a Dacron graft. Antibiotics were administered intravenously in the hospital and continued orally after discharge for at least 6 weeks, until clinical and laboratory parameters were normalized. A review of the literature showed that Gram-negative microorganisms are found in 47% of mycotic TAAAs. A trend toward increased mortality for these organisms, compared with Gram-positive microorganisms, was observed (P =.09). Lifelong antimicrobial therapy is controversial. No difference in survival or recurrence rate was found between series advocating lifelong therapy and those suggesting prolonged (6 weeks to 12 months) therapy (median follow-up period, 18 and 19 months, respectively). In situ repair with synthetic material can be successful if prompt confirmation of infection is obtained, all possibly infected tissue is resected, and antibiotic therapy based on sensitivity data is administered for a prolonged period. A short-term survival rate as high as 82% can be expected with this strategy, but data on long-term survival rates are limited. Polytetrafluoroethylene-expanded grafts, homografts, and antibiotic-bonded grafts may offer advantages over Dacron grafts, but data are insufficient to draw conclusions. Careful long-term follow-up is an important element of the treatment of these patients. We suggest antibiotic treatment until biochemical parameters of inflammation (white cell count, erythrocyte sedimentation rate, or C-reactive protein) return to normal and a computerized tomography scan every 3 months for 1 year, then annually.

Multiple mycotic arch-thoraco-abdominal aortic aneurysms: a successful case of in situ graft replacement

Mycotic aortic aneurysms are an uncommon yet still life-threatening pathology. We report on a 67-year-old male who had a persistent fever and back pain. Contrast enhanced computed tomography (CT) showed multiple aortic aneurysms located in the aortic arch, the descending thoracic aorta and the supraceliac abdominal aorta. After 2 months of antibiotic therapy, a staged operation was carried out with 2-week interval, which includes a graft replacement of aortic arch with elephant trunk technique and a graft replacement of thoraco-abdominal aorta with omental transfer. The postoperative course was uneventful. This case seems to be quite rare in terms of multiplicity and location of mycotic aneurysms. Surgical strategy for this pathology is discussed.

Tuberculous infection of the descending thoracic and abdominal aorta: case report and literature review

We report here a case of infrarenal aortic disruption and aortoduodenal fistula secondary to tuberculous aortitis in a 77-year-old man. From a review of experience with operative management of tuberculous infection of the descending thoracic and abdominal aorta reported in the English-language literature, including the current report, we found that operative repair was attempted in 26 patients with tuberculous aortitis of the abdominal (n = 16), thoracic (n = 8), and thoracoabdominal (n = 2) aorta. Six patients had emergent operations for massive hemoptysis (n = 2), aortoduodenal fistula (n = 2), or abdominal rupture (n = 2), with an associated 30-day mortality of 50%. Elective or semi-elective repair was undertaken in 20 patients, of whom 19 (95%) survived for at least 30 days. On the basis of limited experience with this rare entity, in situ graft replacement is an appropriate treatment of tuberculous aneurysms and pseudoaneurysms of the descending thoracic and abdominal aorta.

Tuberculous mycotic aneurysm of the aorta: review of published medical and surgical experience

To define the epidemiology, pathogenesis, pathology, presentation, and management of tuberculous mycotic aneurysm of the aorta (TBAA) in the therapeutic era, we reviewed all of the cases reported in the English language literature from 1945 to the present. To the 39 cases in the published literature, we add two cases of our own. Although it is exceedingly rare, the prevalence of this lesion has remained relatively constant. In 75% of the cases, TBAA appeared to result from erosion of the aortic wall by a contiguous focus; 25% from direct seeding of the aortic intima or of the adventitia or media (via the vasa vasorum). Most of the aneurysms were saccular (90%) and false (88%). The thoracic and abdominal aortas were affected with equal frequency. The mean (+/- SD) age of the patients was 50+/-16 years. Twenty-two were men, and 19 were women. In 63% of the cases, tuberculosis (TB) was diagnosed at presentation. Disseminated TB was present in 46% of the cases. One or more of three clinical scenarios suggested TBAA: persistent pain, major bleeding, and a palpable or radiographically visible para-aortic mass, especially if it is expanding or pulsatile. In turn, each of these findings suggested a complication of TBAA that may be an indication for surgical intervention. Among the patients who were offered both medical and surgical treatment, 20 of 23 (87%) survived. Among those who were offered only one form of treatment or were offered no treatment at all there were no survivors. Both in situ reconstruction with a prosthetic graft, and extra-anatomic bypass appeared to offer excellent results, provided that an effective regimen of antituberculous drugs was delivered postoperatively. We offer our conclusions: (1) symptomatic TBAA is a rare but uniformly fatal lesion if not diagnosed promptly, (2) in the context of active TB, and especially miliary TB, TBAA should be suspected whenever one or more of the three clinical scenarios are present, and (3) combined medical and surgical therapy appears to offer the best chance of a cure.

Source of elastin-degrading enzymes in mycotic aortic aneurysms: bacteria or host inflammatory response?

Elastolytic matrix metalloproteinases play a central role in the development of chronic atherosclerotic aortic aneurysms, but mycotic aortic aneurysms are a distinct and unusual form of aneurysm disease caused by bacterial infection. Mycotic aortic aneurysms follow a more rapid and unpredictable course than chronic aneurysm disease and they exhibit a predilection for the suprarenal aorta, further implying unique pathophysiologic mechanisms. The purpose of this study was to examine the nature and source of elastin-degrading enzymes in mycotic aortic aneurysm. Bacterial isolates and aortic tissues were obtained from four consecutive patients undergoing surgical repair of suprarenal mycotic aortic aneurysm. Using an in vitro 3H-labeled elastin degradation assay, elastin-degrading enzyme activity was only observed in the bacteria-conditioned medium from an isolate of Pseudomonas aeruginosa. Elastin-degrading enzyme activity in the aortic tissue homogenate of this patient was abolished by the serine protease inhibitor, phenylmethylsulfonyl fluoride, but it was not suppressed by the metalloproteinase inhibitor, ethylenediamine tetraacetic acid (EDTA). In contrast, elastin-degrading enzyme activity in the bacterial-conditioned medium was decreased by about half by both phenylmethylsulfonyl fluoride and EDTA. Elastin substrate zymography revealed two phenylmethylsulfonyl fluoride-inhibitable elastin-degrading enzyme activities in the aortic tissue homogenate that corresponded to human neutrophil elastase (approximately 30 kDa) and its stable complex with alpha 1-proteinase inhibitor (approximately 80 kDa), but no activity attributable to Pseudomonas elastase, a 33-kDa metal-dependent enzyme. Human neutrophil elastase was readily detected throughout mycotic aortic aneurysm tissues by immunohistochemistry, but elastolytic metalloproteinases were only occasionally observed. The results of this study suggest that the elastin-degrading enzyme produced in mycotic aortic aneurysm are largely serine proteases of host neutrophil origin, rather than elastases produced by the infecting microorganisms or the macrophage-derived metalloproteinases typically observed in atherosclerotic aneurysm disease. Further studies will be needed to extend these findings to a larger number of patients with mycotic aortic aneurysm and those caused by additional microorganisms.