Total excision and extra-anatomic bypass for aortic graft infection

Clinical outcome of graft removal versus preservation in abdominal aortic graft infection: a systematic review and meta-analysis

Purpose

The purpose of this study was to compare the clinical outcomes of abdominal aortic graft infection (AGI) treated with removal of the graft vs. graft preservation.

Methods

The electronic databases PubMed, Embase, and Cochrane Library for studies that reported on AGI were searched. Observational studies and case series of at least 10 cases that reporting on the prevalence, microbiology, and outcomes of AGI were included.

Results

Our search identified 23 studies that met our inclusion criteria, reporting on a total of 873 patients who underwent open surgical repair (OSR) or endovascular aneurysm repair (EVAR). Of these patients, 833 received graft removal, and 40 received graft preservation. The prevalence of AGI was reported to be 1.0% (95% confidence interval [CI], 0.5%-1.8%) after OSR and 0.4% (95% CI, 0%-1.1%) after EVAR. The pooled estimates of 1-year, 2-year, and 5-year mortality were 28.7% (95% CI, 19.4%-38.8%), 36.6% (95% CI, 24.6%-49.5%), and 51.8% (95% CI, 38.4%-65.1%) in the graft removal group and 16.1% (95% CI, 4.1%-32.2%), 18.5% (95% CI, 5.7%-35.1%), and 50.0% (95% CI, 31.6%-68.4%) in the graft preservation group. The 30-day mortality rate's risk ratio (RR) for graft removal vs. preservation was 0.98 (95% CI, 0.40-2.38), while the 1-year mortality rate's RR was 3.44 (95% CI, 1.60-7.42).

Conclusion

The 30-day mortality rate of AGI treatment was found to be high, whether using graft removal or preservation. In selected patients, implementing antibiotics with graft preservation as an initial management may be helpful in reducing the mortality rate.

Endovascular Management of Bleeding Aortoenteric Fistula May be Feasible as a Definitive Repair

Aorto-enteric fistula (AEF) is a complication with devastating sequelae and significant morbidity. Although open surgery remains primary treatment endovascular approach may be used as a temporary bridge but rarely as a definitive therapy. We present a case of a patient who presented with a secondary AEF, due to hemodynamic instability we chose to treat the fistula with an aortic endograft. The patient underwent bowel resection due to bowel obstruction with omental patch over the aortic rent, 6 weeks of antibiotics. Patient is now at 8-year follow-up without evidence of infection. Although there is scarce literature on this topic, endovascular treatment of bleeding AEF may be feasible as a definitive option. Due to high risk of graft infection we recommend close observation and suppressive antibiotics.

Extra-Anatomical Bypass Grafting and Latissimus Dorsi Myocutaneous Flap Reconstruction for Post-sternotomy Mediastinitis With Prosthetic Aortic Graft Infection

Extra-anatomical bypass grafting is a surgical method used to remove an infected aortic graft and promote revascularization with a new graft in the non-infected area. Here, we report a case of intractable post-sternotomy mediastinitis (PSM) with aortic graft infection which was treated with extra-anatomical bypass grafting. A 56-year-old woman with a history of multiple aortic dissection and prosthetic graft replacement in the thoracoabdominal area developed PSM with aortic arch graft infection. Bacterial culture of the exposed prosthetic graft tissue yielded multidrug-resistant Pseudomonas aeruginosa. Meticulous debridement of the wound and management by negative pressure wound therapy with continuous irrigation was performed. However, the infection of the prosthetic graft could not be controlled. Extra-anatomical bypass was performed between the left common carotid artery and right subclavian artery via the right common carotid artery. Then, the infected graft was removed. After the resolution of infection, the mediastinal wound was reconstructed with a pedicled latissimus dorsi myocutaneous flap, which was harvested from the right dorsum. No recurrence of infection occurred in the nine-month follow-up period. Debridement and removal of exposed artificial graft are considered the gold standard for treating wound infection. In situ replacement of infected aortic grafts carries a risk of re-infection due to residual bacterial contamination of the periprosthetic tissue. Extra-anatomical bypass would be a useful option for reducing the risk of re-infection in patients with intractable PSM and prosthetic aortic graft infection. Further studies are warranted to evaluate the risks and benefits of this operative method.

Cases of two patients with aortoduodenal fistula who underwent emergency operation

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Aortoduodenal fistula is a rare cause of gastrointestinal bleeding. However, it is life threatening.

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Diagnosis requires a high level of clinical suspicion, and surgery can offer the best chance of survival.

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Primary aortoduodenal fistula is often caused by aortic aneurysm without any previous vascular intervention.

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Secondary aortoduodenal fistula occurs after surgical treatment for abdominal aortic aneurysm.

Introduction

Aortoduodenal fistula (ADF) is a rare but life-threating condition, and it is an important cause of massive gastrointestinal bleeding. Primary ADF often occurs as a result of aortic aneurysm, and secondary ADF develops after the placement of aortic prosthetic graft.

Presentation of cases

Case 1: A 64-year-old man with hematemesis was transferred to our hospital. The patient was diagnosed with primary ADF. Thus, we performed prosthetic graft replacement for an aortic aneurysm, and suturing of the duodenal fistula and duodenojejunal side-to-side anastomosis were performed. He was then discharged on the 35th postoperative day. After 2 years and 10 months, he died of other diseases. Case 2: A 76-year-old man with a history of abdominal aortic aneurysm repair with a prosthetic graft 5 years back who presented with hematemesis and melena was transferred to our hospital. The patient was diagnosed with secondary ADF, and an emergency endovascular aneurysm repair (EVAR) and suturing of the duodenal fistula were perfomed. He was transferred for rehabilitation purposes on the 108th postoperative day but eventually died of pneumonia 6 months after surgery.

Discussion

ADF is associated with high mortality. Initial bleeding is usually minor and often intermittent. However, it leads to severe bleeding and hemorrhagic shock. EVAR is preferred over open surgery because it can be performed faster and is less invasive. Recently, in case of hemorrhagic shock, EVAR is used as first-line treatment.

Conclusion

Accurate diagnosis and immediate treatment are important for the survival of patients with ADF.

Systematic Review and Meta-Analysis on the Management of Open Abdominal Aortic Graft Infections

OBJECTIVE

Aortic graft infection (AGI) is a disastrous complication with an incidence of 0.2-6% in operated patients. With little or no high quality evidence, the best treatment option remains unclear. Therefore, the literature on the management of open abdominal AGI was systematically reviewed to determine optimal treatment.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review and meta-analysis was conducted for AGI. MEDLINE, Embase, and the Cochrane Database of Systematic Reviews were searched. Methodological quality was assessed using the Methodological Index for Non-randomised Studies (MINORS) score. Primary outcomes were 30 day mortality and one year survival. Secondary outcomes were survival, infection recurrence, limb salvage, and graft patency.

RESULTS

Of 1574 studies identified, 32 papers were included in the study. The overall quality of the studies was moderate, with an average MINORS score of 11.9. Pooled overall 30 day mortality and one year survival were 13.5% (95% CI 10.5-16.4) and 73.6% (95% CI 68.8-78.4), respectively. The lowest 30 day mortality and highest one year survival were found for in situ repair compared with extra-anatomic repair and for prosthetic grafts compared with venous grafts or arterial allografts. The infection recurrence rate was highest for prosthetic grafts.

CONCLUSIONS

There is a lack of well designed, qualitative comparative studies making conclusive recommendations impossible. The current best available data suggests that partial graft removal should be avoided and the lowest 30 day mortality and best one year survival are achieved with in situ repair using prosthetic grafts. Initiatives such as the MAGIC database to collaboratively collect prospective data are an important step forward in obtaining more solid answers on this topic.

[Extra-anatomical bypass grafting of the thoracic aorta in a female patient with an infected pseudoaneurysm]

Presented herein is the remote (more than 15-year follow up) result of successful surgical treatment of aortic coarctation complicated by septic aortitis and a false aneurysm of the anastomosis between the graft and the aortic arch. In 2002, after correction of aortic coarctation the woman was admitted to our Clinic with an incompetent proximal anastomosis and an infected aortic pseudoaneurysm. Taking into consideration the general and local septic process, repeat reconstruction of the thoracic aorta was impossible due to the risk for generalization of the infectious process and fatal complications. Therefore, the woman was subjected to extra-anatomical bypass grafting of the thoracic aorta with a synthetic graft from the ascending aorta to the infrarenal portion of the abdominal aorta in order to isolate the infection focus to be followed by removal thereof. The postoperative period turned out uneventful, with no complications. After 15 years, the woman was examined again, with her condition being stable. The findings of contrast-enhanced magnetic resonance imaging demonstrated complete patency of the extra-anatomical bypass graft. The carotid-subclavian anastomosis functioned well, without narrowed portions. No infectious complications after the carried out operations were observed. Using extra-anatomical bypass grafting with exclusion from circulation and removal of the infected portion of the aorta along with the graft is one of reliable variants of treatment for such a severe complication as an infected false aneurysm.

A meta-analysis of outcomes of in-situ reconstruction after total or partial removal of infected abdominal aortic graft

INTRODUCTION

There is currently a lack of evidence for the relative effectiveness of partial resection (PR) and total resection (TR) before managing abdominal aortic graft infection (AGI). Most authorities agree that TR is mandatory for intracavitary AGI in patients with favorable conditions but there is an increasing number of patients with severe comorbidities for whom this approach is not suitable, resulting in a prohibitive mortality rate. The purpose of this study was to determine the most appropriate indication for TR or PR.

EVIDENCE ACQUISITION

A meta-analysis was conducted on the rates of early/late mortality, amputations and reinfection. A meta-regression was performed with eight variables: patient age, male prevalence, presence of virulent or nonvirulent organisms, urgency, omentoplasty and follow-up.

EVIDENCE SYNTHESIS

Twenty-one studies and 1052 patients were included. For TR and PR, the rates of early mortality and reinfection were 16.8% and 10.5%, 11% and 27%, respectively. For TR urgency and male gender were associated with increased rate of early mortality and male gender, PDF and virulent organisms were associated with increased risk of reinfection. For PR no statistical correlation was analyzable except for PDF with increased risk of reinfection.

CONCLUSIONS

Early mortality rates are higher for TR and reinfection rates are higher for PR. For TR early mortality increases in urgent cases and it is suggested that alternative option must be discussed, reinfection decreases in the presence of nonvirulent organisms and TR seems optimal. For TR and PR reinfection increases in presence of PDF and alternative technique may be more appropriate.

Vascular Graft Infections: An update

Vascular graft infection is a devastating complication of vascular reconstructive surgery. The infection can occur early in the postoperative period and is largely due to intraoperative contamination or by contiguous extension from a nearby infection. It can also occur years after implantation. Staphylococci remain the most common organisms and biofilm production makes eradication difficult. Factors commonly reported to predispose to vascular graft infection are periodontal disease, nasal colonization with Staphylococcus aureus, bacteremia, certain graft characteristics, diabetes mellitus, postoperative hyperglycemia, location of the incision, wound infection, and emergency procedure. Management consists of antibiotic and surgical therapy. Preventive methods are described.

Current status of endovascular treatment of aortoenteric fistula

Aortoenteric fistula (AEF) is one of the most challenging diagnostic and therapeutic entities in vascular surgery. AEF can occur either primarily involving the aorta and the gastrointestinal tract or, more commonly, secondary to previous aortic reconstructive surgery. Traditionally, the treatment of AEF includes graft excision and extra-anatomic bypass surgery or in situ graft replacement. However, recently endovascular repair has emerged as an alternative therapeutic option. In this article, we present published and current evidence for endovascular repair of primary and secondary AEF. When endovascular treatment is applied where appropriate, early outcomes seem to be superior compared to open surgery. This benefit may be lost during long-term follow-up, implying that a staged approach with early conversion to in situ grafting may realize the best patient survival and morbidity. Lifelong administration of antibiotics is associated with a reduction in re-infection. An endovascular approach used as a bridging procedure in unstable patients is recommended, followed by definitive open therapy, if feasible, in patients with good life expectancy.

Aortic Graft Infections and Aortoenteric Erosions/Fistulae

Aortic graft infections and graft enteric complications are among the most challenging problems faced by vascular surgeons. Prompt, accurate diagnosis and definitive treatment are essential if major morbidity and mortality are to be avoided. In this paper, the clinical presentation, diagnostic evaluation, and contemporary surgical management of aortic graft infections and graft enteric complications are reviewed. Traditional management techniques (extraanatomic bypass with complete graft removal) are described in detail. Newer and more controversial techniques (management of infected aortofemoral graft limb without graft removal and in situ replacement of infected aortic grafts) are discussed and their results compared with those of traditional treatment.

Recurrent Aortoenteric Fistula: Two Different Bridge Solutions

A “recurrent” aortoenteric fistula (AEF) is very rare and in literature anecdotic. Currently, graft excision and extra-anatomic bypass are considered the treatments of choice, but are associated with significant mortality and morbidity. Herein, we describe the case of a “recurrent” AEF treated before definitive extra-anatomic bypass, by two different, staged bridge solutions: allograft in situ replacement and endovascular grafting. At 1, 3 and 6-month follow-up, the patient was asymptomatic and normally active.

Less-invasive and highly effective method for preventing methicillin-resistant Staphylococcus aureus graft infection by local sustained release of vancomycin

OBJECTIVE

Methicillin-resistant Staphylococcus aureus graft infection is one of the most serious complications of vascular surgery. Vancomycin is a potent antibiotic against methicillin-resistant S. aureus; however, systemic administration of vancomycin is not very effective against methicillin-resistant S. aureus graft infection. Therefore, we investigated whether a local sustained release of vancomycin prevents methicillin-resistant S. aureus graft infection.

METHODS

We have developed a poly-L-lactide-co-caprolactone sheet that enabled sustained release of vancomycin for 2 weeks. An expanded polytetrafluoroethylene vascular graft patch (1.5 mm2) was sutured at the anterior wall of the incised murine abdominal aorta. Methicillin-resistant S. aureus (1.0 x 10(3) colony-forming units) was inoculated onto the graft surface. Thereafter, the graft was treated as follows (n = 6 each): no treatment (control group), local injection of an aqueous solution of vancomycin (vancomycin solution group) and local implantation of poly-L-lactide-co-caprolactone containing vancomycin (vancomycin-PLCA group). After 7 days, the graft and blood were sampled and cultured.

RESULTS

The methicillin-resistant S. aureus counts in the grafts of the vancomycin-PLCA group were significantly lower than those of the other groups. Blood cultures of the vancomycin-PLCA group were all negative, whereas those of the other groups were all positive for infection. The survival rate in the vancomycin-PLCA group at 28 days was considerably higher than that in the control group (83.3% vs 16.7%).

CONCLUSIONS

A local sustained-release sheet containing vancomycin reduced methicillin-resistant S. aureus counts in the infected vascular grafts, prevented sepsis, and drastically improved survival rates. This can be used as a highly effective and less-invasive adjunctive treatment method for preventing prosthetic methicillin-resistant S. aureus graft infection.

[Repair of secondary aortoenteric fistulas. A systematic review]

We performed a systematic review of the literature on the diagnosis and treatment of secondary aortoenteric fistulas (AEF). A MEDLINE search was performed of articles published in English or Spanish between January 1991 and August 2006. Diagnostic methods, treatment modalities and the results of surgical treatment were analyzed. The most frequent first aortic surgery associated with AEF was repair of abdominal aortic aneurysm (54.31%). The most common form of presentation was gastrointestinal bleeding. Repair through in situ prosthetic replacement had the lowest early mortality rates (8-13.3%) compared with graft excision and extraanatomic revascularization (18.2-44%). AEF is a serious entity and diagnosis requires a high index of suspicion based on clinical findings and indirect data from imaging techniques (computed tomography). The most appropriate therapeutic option continues to be controversial.

Derivação arterial extra-anatômica no segmento aorto-ilíaco: experiência de 15 anos

RESUMO CONTEXTO: As derivações extra-anatômicas, sendo procedimentos cirúrgicos alternativos à cirurgia clássica, têm como principal objetivo simplificar um procedimento de grande porte como a restauração aorto-femoral. OBJETIVOS: Analisar os resultados a longo prazo das derivações extra-anatômicas no segmento aorto-ilíaco. MÉTODOS: Estudo longitudinal retrospectivo envolvendo 79 derivações extra-anatômicas no segmento aorto-ilíaco, realizadas em 75 pacientes, no período de dezembro de 1991 a dezembro de 2006. RESULTADOS: Média de idade foi 64,2 anos, com predominância pelo gênero masculino (64%). A isquemia crítica foi a responsável pela maioria das indicações cirúrgicas (86,1%) e a derivação ilíaco-femoral cruzada representou 41,8% dos casos. Em cinco anos, as taxas de mortalidade geral, perviedade e salvamento do membro foram, respectivamente, de 28%; 70,3% e 67,6% em cinco anos. CONCLUSÕES: As derivações extra-anatômicas devem permanecer como cirurgias alternativas, pois apresentam taxas de perviedade inferiores aos procedimentos que seguem as vias anatômicas naturais além de morbimortalidade considerável. Entretanto, são procedimentos importantes nos casos em que a limitação de ordem clínica ou de natureza local torna difícil ou impede a revascularização por via anatômica. As derivações cruzadas apresentaram perviedade superior às derivações axilo-femorais e as ilíaco-femorais cruzadas revelaram a maior perviedade entre todas (77,3% em cinco anos).

Neuraminidase decreases in vitro adherence of slime-forming coagulase-negative staphylococci to biosynthetic ovine collagen vascular graft

Vascular prosthetic graft infection is a major complication of vascular surgery that starts with adhesion of the microorganism to the graft. Because slime-forming microorganisms are the major causative agents in graft infection, the goals of investigators in this study were (1) to investigate the bacterial adherence of slime-forming and non-slime-forming coagulase-negative staphylococci (CNS), and (2) to determine the role of neuraminidase (NANase) in bacterial adherence to the biosynthetic ovine collagen graft. Human plasma was instilled and incubated at 37 degrees C in preparation for fibrin deposition of grafts. After 48 hours, incubation grafts were drained and inoculated with slime-forming and non-slime-forming CNS in tryptic soy broth in the presence and in the absence of neuraminidase. After 24 hours of incubation at 36 degrees C, grafts were vortexed and cultured for colony count. Bacterial counts were expressed as total colony-forming units per longitudinal centimeter of the graft. Slime-forming CNS had greater affinity to the collagen graft compared with non-slime-forming CNS (P<.05). Adherence of slime-forming CNS was impaired by NANase treatment (P<.001). NANase treatment of patients with non-slime-forming CNS did not change adherence to the graft (P>.05). Results show that slime plays an important role in the pathogenesis of vascular graft infection. Adherence of slime-forming CNS can be decreased through the administration of NANase. This may have implications for the development of neuraminidase-embedded vascular grafts designed to reduce the occurrence of biomaterial-related infection.

Nuclear medicine imaging of inflammatory/infective disorders of the abdomen

Different nuclear medicine modalities are currently used to study inflammatory and infective disorders of the abdomen. They are usually complementary to radiology and endoscopy, but they play a pivotal role in particular clinical situations. Several radiopharmaceuticals (e.g., 111In or 99mTc labelled white blood cells, monoclonal antibodies, human polyclonal immunoglobulins, 75Ga citrate) are commercially available, but they can not be used indifferently to study abdominal inflammatory disorders. The lack of comparative studies showing the accuracy of each radiopharmaceutical for the study of inflammatory/infective abdominal diseases does not allow the best nuclear medicine technique(s) to be chosen in an evidence-based manner. To this end we performed a meta-analysis of peer reviewed articles published between 1984 and 2004 describing the use of nuclear medicine imaging for the study of inflammatory bowel disorders, appendicitis and vascular graft infections. A guideline for the optimal radiopharmaceutical(s) to be used in each clinical condition and for different aims is provided.

Management of Infected Grafts and Aneurysms of the Aorta

Seventeen patients treated for infected grafts (11/17) or aneurysms (6/17) of the aorta between 1998 and 2003 were reviewed to evaluate our experience with aortic infection. The causative organisms were identified in 12 patients (71%), with 5 (29%) having methicillin-resistant Staphylococcus aureus. A periaortic abscess occurred in eight patients, and all of them were associated with infected grafts. Surgical treatment included cryopreserved allograft replacement in eight patients, prosthetic graft replacement in four patients, and drainage with or without omental wrapping in five patients. One patient was still hospitalized at the end of the study period. Five patients with infected grafts died after the operation during the initial hospitalization. No early mortality occurred in the aneurysm group. The early mortality rate was 31% for all patients, 50% for the graft group, and 63% for patients with a periaortie abscess. Another patient with an infected aneurysm died of arrhythmia after discharge from the initial hospitalization, Ten patients are still alive without evidence of reinfection. The early mortality rate for patients with infected aortic grafts is higher than that for those with infected aneurysms, especially when a periaortic abscess accompanies them. However, the late outcome is favorable, with no reinfection or late treatment-related deaths.

Primary aortoenteric fistula

BACKGROUND

A primary aortoenteric fistula (PAEF) is a rare clinical entity that results in fatal exsanguination if undiagnosed. The present study investigates whether management and survival have altered over time.

METHODS

A Medline search was conducted for the period from January 1994 to December 2003. Data were categorized and compared with reviews of PAEF published before this interval.

RESULTS

The classical triad (gastrointestinal bleeding, pain and a pulsating mass) was present in only 11 per cent of 81 patients. Most PAEFs were caused by an aneurysmal aorta and were almost always (94 per cent) heralded by repetitive gastrointestinal bleeds. Computed tomography (CT) provides images superior to those of other diagnostic modalities, such as gastroduodenoscopy or conventional angiography. Operative mortality rates were lower in later years possibly owing to improvements in perioperative care and the advent of endovascular techniques.

CONCLUSION

Gastrointestinal bleeding combined with a negative endoscopy in the presence of an aneurysmal aorta suggests PAEF and requires urgent evaluation by CT. Endovascular operation is an attractive treatment option.

Operative Strategies in Aortic Graft Infections: Is Complete Graft Excision Always Necessary?

The classic approach to aortic graft infections involves complete excision of the graft material with remote reconstruction of the distal circulation. Certain patients may not be well suited for this approach for physiologic or anatomic reasons. This study was undertaken to determine the outcome of partial graft excision in selected patients with aortic graft infection who were not felt to be candidates for complete graft excision. Retrospective analysis of 30 consecutive patients treated with infected grafts arising from the aorta over the past 10 years was performed. Mean interval between graft placement and infection was 5.5 years. Complete graft excision with bypass via clean tissue planes was achieved in 15 patients (group A), and partial or complete graft salvage or in situ graft replacement was performed at the discretion of the surgeon in 15 patients (group B). Perioperative mortality occurred in eight subjects (27%), including six in group A (40%) and two in group B (13%; p = NS). Six patients (20%) developed recurrent infection following graft excision, two (13%) in group A and four (27%) in group B (p = NS). Microorganisms were recovered from 24 of 30 (80%) graft cultures: 13 (43%) were gram positive, 4 (13%) were gram negative, and both gram-positive and gram-negative organisms were recovered from 7 (23%). Identification of culture isolates did not influence either perioperative mortality or the development of recurrent infection. Long-term survival was no different between the groups. We conclude that in certain high-risk patients who may not tolerate complete graft excision, local resection of infected graft segments may be preferable and leads to similar short- and long-term outcome.

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.

Intra-abdominal aortic graft infection: complete or partial graft preservation in patients at very high risk

BACKGROUND

Total graft excision with in situ or extra-anatomic revascularization is considered mandatory to treat infection involving the body of aortic grafts. We present a series of nine patients with this complication and such severe comorbid medical illnesses or markedly hostile abdomens that traditional treatments were precluded. In these patients selective complete or partial graft preservation was used.

METHODS

Over the past 20 years we have treated nine infected infrarenal aortic prosthetic grafts with complete or partial graft preservation, because excision of the graft body was not feasible. In all nine patients infection of the main body of the aortic graft was documented at computed tomography or surgery. Essential adjuncts included percutaneous or operative drain placement into retroperitoneal abscess cavities and along the graft, with instillation of antibiotics three times daily, repeated debridement of infected groin wounds, and intravenous antibiotic therapy for at least 6 weeks.

RESULTS

One patient with purulent groin drainage treated with complete graft preservation died of sepsis. One patient with groin infection treated with complete graft preservation initially did well, but ultimately required total graft excision 5 months later, after clinical improvement. In four patients complete graft preservation was successful; two patients required excision of an occluded infected limb of the graft; and one patient underwent subtotal graft excision, leaving a graft remnant on the aorta, and axillopopliteal bypass. In summary, seven of nine patients survived hospitalization after complete or partial graft preservation; amputation was avoided in all but one patient; and no recurrent infection developed over mean follow-up of 7.6 years (range, 2-15 years).

CONCLUSIONS

Although contrary to conventional concepts, partial or complete graft preservation combined with aggressive drainage and groin wound debridement is an acceptable option for treatment of infection involving an entire aortic graft in selected patients with prohibitive risks for total graft excision. This treatment may be compatible with long-term survival and protracted absence of signs or symptoms of infection.

Early and Long-term Results of Conventional Surgical Treatment of Secondary Aorto-enteric Fistula

OBJECTIVE

To retrospectively evaluate early and late results of surgical treatment of secondary aorto-enteric fistulas (SAEFs) with prosthetic excision and extra-anatomic bypass (conventional treatment) in a single centre institution (teaching hospital).

MATERIALS AND METHODS

Between January 1990 and March 2002, 30 patients underwent conventional surgical treatment for SAEF. Data concerning these operations were collected in a dedicate database and 30-day mortality, patency and limb salvage rates were evaluated by mean of chi-square test and logistic regression analysis. Clinical and ultrasonographic follow-up was performed; late results were evaluated by mean of Kaplan-Meyer curves.

RESULTS

Thirty day mortality rate was 26% (8 patients). Timing and sequence of interventions (simultaneous or staged, prosthetic excision or revascularization before) had no significative influence on perioperative mortality. There were six extranatomic bypass thromboses at 30 days, but no amputation. Mean duration of follow-up was 24 months; estimated 12- and 24-month survival rates were 60 and 50%, respectively. There were better results in terms of long-term survival in patients undergone prosthetic graft excision before. Primary patency rate was 62% and limb salvage rate was 95%, both at 24 months. Two prosthetic graft reinfections occurred during follow-up (9%). Cumulative reinterventions rate during follow-up was 18%.

CONCLUSIONS

Conventional surgical treatment of SAEF permitted, in our experience, satisfactory early and long terms results, with fair rates of patency and limb salvage. Surgical timing and sequence do not seem to affect early results.

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.

Treatment of periprosthetic soft tissue infection of the groin following vascular surgical procedures by means of a polyvinyl alcohol-vacuum sponge system

Deep groin infections after prosthetic vascular surgical procedures represent a serious complication of surgical practice. Septicemia and/or erosive hemorrhage can both be consequences. In this situation, removal of the graft appears to be the only option. However, if the infection is detected early (type Szilagyi III), local treatment to eradicate the infection could serve as an alternative. Twenty-four patients with confirmed infection of the soft tissue adjacent to the prosthetic material in the groin were treated locally by implantation of a vacuum sponge system. Duration of this treatment was 2 weeks. All patients showed excellent tissue granulation of the wound area and the microbial stains were negative at the end of therapy. In 21 patients the wound could be primarily closed after explantation of the sponge. Three patients underwent open treatment because of a skin defect. After 12 months, the wounds had healed well in all patients. Histologic evaluation revealed a physiological healing process. Deep soft tissue infections of the groin adjacent to prosthetic vascular material (type Szilagyi III) can be treated effectively and safely with the vacuum sponge system. The treatment is inexpensive, easy to perform, and the initial vascular reconstruction can be preserved.

Patency of superficial femoral vein employed as a crossover femoral artery bypass conduit

This study assesses the patency of superficial femoral vein used as a crossover femoral artery bypass conduit in patients presenting either with localized groin sepsis, generalized sepsis or in patients with occluded or heavily diseased superficial femoral artery outflow. Twenty patients were followed prospectively with femoral crossover grafts constructed of superficial femoral vein. Twelve patients presented with sepsis and 8 with chronic ischemia from iliac artery occlusion and severely diseased superficial femoral artery outflow. Graft patency was assessed with regular duplex ultrasound examination. There was one perioperative death. Six patients died during the follow-up period. Mean follow-up time was 24.3 months. No graft occluded or required revision. There was no limb loss, graft infection, or graft hemorrhage. Superficial femoral vein offers an effective femoral crossover bypass graft in patients with either localized/generalized sepsis or disadvantaged outflow tracts.

Endovascular repair of bleeding aortoenteric fistulas: a 5-year experience

PURPOSE

Aortoenteric fistula (AEF) is an uncommon but catastrophic complication that can occur either primarily or after aortic reconstruction. Untreated, it is uniformly fatal. Conventional surgical management is associated with a perioperative mortality rate of 25% to 90% and frequent major complications. We reviewed our experience with the endovascular treatment of both primary and secondary AEFs in an effort to determine whether endovascular repair is a less morbid alternative to traditional surgical treatment in select patients.

METHODS

In a 5-year period, seven high-risk patients who had bleeding and an AEF documented by means of radiology or endoscopy (2 primary, 5 secondary) were treated with coil embolization (1) or placement of an endovascular aortic stent graft (3 aortouniiliac, 2 tube, 1 bifurcated). One patient underwent computed tomography (CT)-guided percutaneous catheter drainage of an infected perigraft collection. The average follow-up period was 27 months (range, 11-66 months), and follow-up consisted of physical examination, complete blood count, and contrast-enhanced helical CT scanning at 3, 6, and 12 months and yearly thereafter. All patients were treated with intravenous antibiotics perioperatively and were prescribed life-long oral antibiotics on discharge.

RESULTS

There was one perioperative death (14%) caused by fungal sepsis. Persistent sepsis after stent-graft placement necessitated laparotomy and bowel resection in one patient. One patient had three bouts of recurrent sepsis that were successfully treated with a change of antibiotic. There were three late deaths (43%) unrelated to the procedure or AEF. Three patients (43%) were alive and well an average of 36 months (range, 23-67 months) after the procedure, with no clinical or radiologic evidence of recurrent bleeding or infection.

CONCLUSION

Endovascular management of AEFs is technically feasible and may be the preferred treatment in select patients with bleeding and no signs of sepsis. In the setting of gross infection, it may also be considered in high-risk patients as a bridge to more definitive treatment after hemodynamic stabilization and optimization.

Long-term results of cryopreserved arterial allograft reconstruction in infected prosthetic grafts and mycotic aneurysms of the abdominal aorta

PURPOSE

This prospective, observational study determined the long-term outcome in patients with abdominal aortic infection (primary or prosthetic graft) who were treated with simultaneous aortic/graft excision and cryopreserved arterial allograft reconstruction.

METHODS

From April 1992 to March 2000, patients with abdominal aortic infection underwent complete or partial excision of the infected aorta/prosthetic graft and cryopreserved arterial allograft reconstruction. Arterial allografts were harvested from multiple organ donors and cryopreserved at -80 degrees C without rate-controlled freezing. The patients were observed for survival, limb salvage, persistence and/or recurrence of infection, and allograft patency. The results were calculated with life-table methods.

RESULTS

During the 8-year study period, 28 consecutive patients (27 men, 1 woman; mean age, 64 years) underwent treatment for abdominal aortic infection (23 graft infections, including 7 graft-enteric fistulas and 5 primary aortic infections). Allograft reconstruction was performed as an emergency procedure in 13 patients (46%). The mean follow-up period was 35.4 months (range, 6-101 months). The overall treatment-related mortality rate was 17.8% (17% for graft infection, 20% for primary aortic infection). The overall 3-year survival was 67%. There was no early or late amputation. There was no persistent or recurrent infection, and none of the patients received long-term (> 3 months) antibiotic therapy. Reoperation for allograft revision, excision, or replacement was necessary in four patients (17%) who were available for examination, with no reoperative perioperative death. The 3-year primary and secondary allograft patency rates were 81% and 96%, respectively.

CONCLUSION

Our experience with cryopreserved arterial allograft in the management of abdominal aortic infection suggests that this technique seems to be a useful option for treating one of the most dreaded vascular complications.

Endovascular grafting of traumatic aortic aneurysms in contaminated fields

PURPOSE

To evaluate the potential of endovascular stent-grafts to treat traumatic aortic lesions in contaminated areas.

METHODS

Four patients (3 women; ages 26-78 years) underwent stent-grafting to repair an aortic rupture sustained in a motorcycle accident, aortic lacerations secondary to surgical treatment of spondylitis in 2 patients, and an aortobronchial fistula following surgical thoracic aortic repair 10 years earlier. Stent-grafts (2 Corvita, 1 Talent, and 1 Vanguard) were placed endoluminally into the infected areas via a transfemoral approach. Follow-up included erythrocyte sedimentation rate, white blood count, C-reactive protein, blood cultures, and computed tomography (CT).

RESULTS

The stent-grafts were successfully placed in all cases and excluded the aortic lesion. Under supportive antibiotic therapy, inflammation parameters returned to normal. CT imaging showed no evidence of paraprosthetic infection, nor were there any other complications over a follow-up that ranged from 3 to 34 months.

CONCLUSIONS

Endovascular therapy may be an alternative in the acute management of aortic ruptures in the setting of infection. Long-term results are required for definitive evaluation of the method.

Improved results with conventional management of infrarenal aortic infection

PURPOSE

Interest in alternative methods, such as autogenous vein grafts and aortic allografts, for the management of infrarenal aortic infection (IRAI) has been stimulated by the historically disappointing results with conventional surgical management. Recently, there have been dramatic improvements in the results of axillofemoral bypass grafting (AXFB) followed by excision of the IRAI that have gone relatively unrecognized. The purpose of this report is the presentation of modern-day results in the treatment of IRAI with conventional surgical methods.

METHODS

From January 1, 1983, through June 30, 1998, patients with IRAI underwent treatment with AXFB and complete excision of the IRAI. The patients were followed for survival, limb salvage, and AXFB graft patency. The results were tabulated with life-table methods.

RESULTS

During the 15-year study period, 60 patients (51 men, nine women; mean age, 68 years) underwent treatment for IRAI (50 graft infections, including 16 graft-enteric fistulae, and 10 primary aortic infections). The mean follow-up period was 41 months. The perioperative mortality rate was 13% (12% for graft infection, and 20% for primary infection). The overall 2-year and 5-year survival rates were 67% and 47%, respectively. The limb salvage rates at 2 and 5 years were 93% and 82%, respectively. The 5-year primary AXFB graft patency rate was 73%.

CONCLUSION

These results show an improvement with the conventional management of IRAI equal or superior to those results reported with alternative methods, including femoral vein grafts or aortic allografts. These results should be regarded as the modern standard with which alternative therapies can be compared.

In situ replacement of infected aortic grafts with rifampicin-bonded prostheses: the Leicester experience (1992 to 1998)

PURPOSE

Prosthetic graft infection after aortic aneurysm surgery is a life-threatening complication. Treatment options include total graft excision and extra-anatomic bypass grafting or in situ replacement of the graft. The latter option is gaining increasing popularity, but the long-term outcome remains uncertain, particularly in light of the increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA). We performed a prospective nonrandomized study to assess the outcome after graft excision and in situ replacement with a rifampicin-bonded prosthesis for the treatment of major aortic graft infection.

METHODS

In a 6-year period from January 1992 to December 1997, 11 patients (eight men, three women) with major aortic graft infection underwent total graft excision and in situ replacement with a rifampicin-bonded prosthesis. The median age of the patients was 66 years (range, 49 to 78 years). Four patients had a hemorrhage from an aortoenteric fistula, three had a retroperitoneal abscess, two had graft occlusion, one had a perigraft collection shown by means of computed tomography, and one had a ruptured suprarenal false aneurysm. Organisms were cultured from 10 patients.

RESULTS

MRSA was isolated in two patients, both of whom had originally undergone repair of a ruptured abdominal aortic aneurysm. Two patients died (18.2%) within 30 days, and three patients (27.6%) had nonfatal complications (peritoneal candidiasis, transient renal impairment, and profound anorexia). Two patients died late in the follow-up period. Seven patients remain alive and clinically free of infection.

CONCLUSION

The long-term results after total graft excision and in situ replacement with a rifampicin-bonded prosthesis appear to be favorable. However, MRSA aortic graft infection appears to be associated with a poor prognosis.

Management of infected aortic grafts: development of less invasive surgery using cryopreserved homografts

BACKGROUND

Aortic graft infection is associated with significant mortality and morbidity. Total graft replacement with homografts provides an effective treatment. Partial graft replacement at the site of infection may simplify the surgical procedure.

METHODS

Between January 1991 and December 1996, homografts were used in 18 patients (mean age, 61+/-12 years; range 41-85) with thoracic (4/18; 22%) or abdominal (14/18; 78%) aortic graft infection. Sepsis was present in 14 patients (78%); 6 (33%) had various aortic fistulae. Total graft replacement using homografts was performed in 14 (78%), and partial graft replacement at the site of infection in 4 patients (22%).

RESULTS

Hospital mortality was 11%. During the follow-up period of 22+/-15 months (range, 12-65) there was 1 infection and 1 homograft-related late death after complete homograft replacement, and 1 percutaneous vascular stent placement after partial graft replacement. No other instances of reinfection, suture line rupture or anastomotic aneurysms were observed.

CONCLUSION

Total graft replacement with homografts provides an effective treatment for infected aortic grafts. Partial graft replacement at the site of infection is feasible and safe.

Autologous superficial femoral vein for aortic reconstruction in infected fields

Autogenous reconstruction is one option available for patients with aortic graft infection or mycotic aneurysms. We reviewed our recent institutional experience with all patients undergoing aortic reconstruction using autologous superficial femoral vein (SFV). Between February 1995 and November 1997, eight patients (five with prosthetic aortic graft infection and three with mycotic aneurysms, including one ruptured mycotic aneurysm) underwent single-stage aortic reconstruction using autologous SFV. Therapy for graft infection included graft excision and replacement with aortobifemoral or aortofemoral (with subsequent cross femoral) grafts fashioned from the SFV. The two patients undergoing elective repair of mycotic aneurysms were treated with extensive SFV patches, and the patient with a ruptured mycotic aneurysm underwent SFV tube grafting. Autogenous reconstruction of the aorta using the SFV in infected fields shows promise for salvage of life and limb during early experiences and short-term follow-up. Morbidity and mortality rates compare favorably with those from existing series, reconstruction is anatomic, and reinfection potential is low. Long-term follow-up and more extensive experience with this technique are needed to establish its role relative to other conventional methods.

Cryopreserved arterial allografts in the treatment of major vascular infection: a comparison with conventional surgical techniques

OBJECTIVE

Recent findings with cryopreserved heart valve allografts in the treatment of infectious endocarditis suggest that the use of cryopreserved arterial allografts may improve the outcome in patients with vascular infections.

METHODS

Seventy-two patients with mycotic aneurysms (n = 29) or infected vascular prostheses (n = 43) of the thoracic (n = 26) or abdominal aorta (n = 46) were treated with in situ repair and extra-anatomic reconstruction using prosthetic material (n = 38) or implantation of a cryopreserved arterial allograft (n = 34). Disease-related survival and survival free of reoperation were assessed. Morbidity, cumulative lengths of intensive care, hospitalization, antibiotic treatment, and costs were calculated per year of follow-up.

RESULTS

The use of cryopreserved arterial allografts was superior to conventional surgery in terms of disease-related survival (P =.008), disease-related survival free of reoperation (P =.0001), duration of intensive care per year of follow-up (median 1 vs 11 days; range 1 to 42 vs 2 to 120 days; P =.001), hospitalization (14 vs 30 days; range 7 to 150 vs 15 to 240 days; P =.002), duration of postoperative antibiotic therapy (21 vs 40 days; range 21 to 90 vs 60 to 365 days; P =.002), incidence of complications (24% vs 63%; P =.005), and elimination of infection (91% vs 53%; P =.001). In addition, costs were 40% lower in the group treated by allografts (P =.005).

CONCLUSIONS

The use of cryopreserved arterial allografts is a more effective treatment for mycotic aneurysms and infected vascular prostheses than conventional surgical techniques.

An aggressive local approach to vascular graft infection

PURPOSE

To present the use of sartorius myoplasty (SM) and superficial femoral vein (SFV) in a graft-sparing approach to vascular graft infection.

METHODS

Twenty-five patients were treated for Szilagyi grade III groin infections during the last 10 years. Fifteen presented early (E), mean 2 months; 10 late (L), mean 6.5 years. Bacteria E/L: Staphylococcus epidermidis 1/7, S aureus 6/0, other gram positive 1/0, gram negative 4/1, mixed 6/0 (one pseudomonas). There were 13 aortofemoral (AF), 5 crossover, and 7 femoral distal reconstructions. SM was used to cover exposed grafts after radical debridement. When the graft was free-floating or bleeding, this segment was removed and replaced with SFV. The remaining infection was controlled with antibiotics.

RESULTS

One of 10 patients treated by SM alone required SFV replacement for bleeding. Four of 9 AFs treated by partial SFV replacement +/- SM had persistent infection treated by complete graft removal in 3. Six grafts were removed electively in lower risk situations. There was no perioperative mortality, and no early or late limb loss.

CONCLUSIONS

This experience supports an attempt at aggressive local treatment in frail patients.