Multidisciplinary Treatment Approach for Prosthetic Vascular Graft Infection in the Thoracic Aortic Area

Prosthetic vascular graft infection in the thoracic aortic area is a rare but serious complication. Adequate management of the complication is essential to increase the chance of success of open surgery. While surgical site infection is suggested as the root cause of the complication, it is also related to decreased host tolerance, especially as found in elderly patients. The handling of prosthetic vascular graft infection has been widely discussed to date. This paper mainly provides a summary of literature reports published within the past 5 years to discuss issues related to multidisciplinary treatment approaches, including surgical site infection, timing of onset, diagnostic methods, causative pathogens, auxiliary diagnostic methods, antibiotic treatment, anti-infective structures of vascular prostheses, surgical treatment, treatment strategy against infectious aortic aneurysms, future surgical treatment, postoperative systemic therapy, and antimicrobial stewardship. A thorough understanding of these issues will enable us to prevent prosthetic vascular graft infection in the thoracic aortic area as far as possible. In the event of its occurrence, the early introduction of appropriate treatment is expected to cure the disease without worsening of the underlying pathological condition.     

Management of the aortic graft infection

Prosthetic graft infection is a life-threatening complication in aortic surgery. Ectopic gas, perigraft fluid collection, and pseudoaneurysm can be detected by CT scanning. In cases of graft-enteric fistula, the prosthetic material can sometimes be observed using gastroduodenoscopy. Several methods of treatment have been attempted clinically. Removal of the infected graft and additional extra-anatomic bypass are associated with acceptable surgical outcomes, although the mortality rates are high because of persistent infection or aortic stump rupture. In-situ prosthetic graft replacement or omental transposition has also been attempted, although control of the infection has rarely been achieved. In-situ replacement with a cyropreserved aortic allograft considered to be resistant against infection has recently been performed. The immunological rejection or long-term patency rate of aortic allografts is unknown. However, this technique appears to be a useful option for the management of aortic graft infection.     

Antibiotic irrigation and conservative surgery for major aortic graft infection

Purpose: Traditional surgical treatment for panprosthetic aortic graft infection entails radical excision of the graft, aortic stump closure, and extraanatomic revascularization of the lower limbs. This carries an early mortality rate of 24% to 45%. Amputation rates range from 11% to 37%. Multiple operations and prolonged hospital stay are usual. We have developed a more conservative management technique with the aim of improving outcome.Methods: We describe an innovative method of treating the condition with prolonged, high-dose, local antibiotic irrigation therapy, systemic antibiotic treatment, surgical debridement, and graft conservation in a prospectively studied series of 10 patients.Results: The actual 30-day patient survival rate is 90%, the 1-year survival rate is 80%, and the 4-year survival rate is 67%. Two patients died because of graft infection, and the third died, uninfected, of an unrelated cause. No limbs have been amputated. Only two patients required a second operation. Mean postoperative hospital stay was 32 days. The seven survivors have been closely followed up with regular computed tomography or indium scanning and clinical examination and appear to be free from infection at a mean of 61 months after cessation of irrigation therapy.Conclusion: The technique appears to represent a significant improvement in the management of this major complication of vascular surgery. (J V ASC S URG 1994;20:88-95.)     

Aorto-enteric Fistula After Endovascular Abdominal Aortic Aneurysm Repair: Case Report and Review

ObjectiveTo report a case and to review previous publications regarding the rare complication of aorto-enteric fistula following endovascular aortic aneurysm repair.MethodsWe report the case of a stent-graft infection secondary to an aorto-enteric fistula 14 months after uncomplicated endovascular treatment of an infra-renal aortic aneurysm.ResultsThe surgical treatment involved the removal of the infected graft and in situ aortic replacement by cryopreserved allograft. There have been no major complications noted during the 2-month follow-up after surgery.ConclusionsAn aortojejunal fistula is a possible long-term complication of endovascular treatment of abdominal aortic aneurysm. An explantation of the infected graft and aortic replacement by a cryopreserved allograft is a valuable surgical treatment.     

Conservative Treatment of an Early Aortic Graft Infection Due to Acinetobacter baumanii

Acute infection of an aortic graft is a devastating complication. While resection of the infected prosthesis and extra-anatomic bypass is the established treatment, this carries a high mortality. We describe a case of early aortic graft infection with the unusual organism Acinetobacter baumanii, which was eradicated by a combination of surgical drainage and antibiotics, allowing preservation of the graft. The patient remains well 30 months later.     

Local infections after above-knee prosthetic femoropopliteal bypass for intermittent claudication

BACKGROUND: The use of prosthetic grafts in the treatment of intermittent claudication is still a controversy. Prosthetic bypass for this usually benign condition may in some cases lead to a graft infection. This potentially disastrous complication is difficult to manage. METHODS: One hundred forty-one consecutive operations done on 129 patients between January, 1990 and December, 2001 in a single university vascular unit have been studied. Lymphatic complications and local infections have been related to preoperative risk factors, complications, secondary procedures, and outcome. RESULTS: During a mean follow-up period of 42 months, lymph complications occurred after 18 operations, surgical site infection after 11 procedures, and graft infection after 17 operations. Eleven infected grafts were treated successfully without graft excision. Six of these grafts healed with antibiotics only. The risk of developing a local infection was significantly correlated with postoperative lymph fistula. Reoperative surgery was associated with graft infection. Graft infection caused by Staphylococcus aureus always warranted surgery, either local revision or graft excision. CONCLUSIONS: The present series had a high frequency of graft infections. Our data suggest that a selective approach should be taken towards excision of infected femoropopliteal prostheses. The need for and extent of surgery should be individualized according to the clinical presentation of the graft infection and the type of bacteria involved. We advocate a conservative attitude towards surgical treatment of intermittent claudication.     

Clostridium septicum post-endovascular aneurysm repair stent-graft infection

Endovascular aortic aneurysm repair (EVAR) is establishing its role as a valid alternative for the treatment of abdominal aortic aneurysm. Post-EVAR graft infection is a rare and devastating complication. The incidence of post-EVAR graft infection is yet to be defined, and available data at this stage consist of case reports and small series. Possible etiologies for aortic stent-graft infection include perioperative contamination and hematogenous seeding. To the best of our knowledge, this is the first report of post-EVAR stent graft infection with Clostridium septicum. The possible mechanisms of this unusual hematogenous seeding have been discussed.     

Conservative treatment of aortic graft infection

Conservative, nonresectional management of aortic graft infections is the optimal management for selected patients with aortic graft infections. The best candidates are those patients who have significant comorbidities, or where the existing aortic graft is in a location that precludes excision without causing a high likelihood of morbidity and/or mortality, such as thoracoabdominal and aortic arch grafts. When considering the conservative approach, computed tomographic angiography, supplemented by Indium(111) leukocyte scanning, is the best combination of diagnostic tests. Contraindications to a conservative approach are infected anastomotic aneurysms, graft-enteric fistulas, and suture-line hemorrhage. Needle aspiration of perigraft fluid or phlegmon, under ultrasound or computed tomography guidance, is useful to both culture the infection and provide drainage. A conservative approach should not be considered when the graft infection is due to invasive Gram-negative organisms, such as Pseudomonas or Salmonella species. Once a conservative approach is selected as the best treatment option, drainage of an infected perigraft space is critical to success, and can be performed either percutaneously or with open surgery, whether an endograft or surgically placed graft is in place. If open drainage is required, the perigraft space should be debrided and catheters placed for long-term antibiotic irrigation. With continuous antibiotic irrigation until the cultures are negative, followed by life-long oral antibiotics, there are multiple case reports and small series of long-term survivors. Whether the aortic graft infection is cured or controlled is debated, but outcomes for high-risk patients and those with grafts in critical vascular beds are often superior to a high-risk surgical graft resection.     

Postoperative mediastinitis following hemiarch replacement

Although various strategies have been advocated for mediastinitis following cardiac operations, surgical results for this complication remain a significant concern. The condition would be more complicated with replacement of the ascending aorta using a prosthetic graft. We present the case of a 50-year-old female patient with acute aortic dissection who underwent hemiarch replacement using a prosthetic graft and concomitant coronary artery bypass grafting, and developed periprosthetic purulent collection 2 months later. Successful treatment involved debridement of infected tissues and omental flap transposition. Postoperative chest computed tomography revealed no sign of perigraft infection. Omental flap transposition can be effective for treating mediastinitis following prosthetic graft replacement of the ascending aorta. The patient has remained in good health for 1 year, with no signs of recurrent graft infection or pseudoaneurysm formation.     

Autologous deep vein reconstruction of infected thoracoabdominal aortic patch graft

Graft infection remains a serious complication of prosthetic aortic repair. Infection of thoracoabdominal aortic prosthetic grafts, in particular, is a significant clinical challenge and is associated with high mortality. We report successful in situ reconstruction of an infected thoracoabdominal aortic prosthetic patch graft with autogenous superficial femoral vein. To our knowledge, this is the first such case described in the North American and English language surgical literature. At 24-month follow-up the patient remains well, with no evidence of sepsis or graft complication at clinical and radiologic assessment.     

Reoperation for composite graft infection after aortic root replacement

Composite graft infection after aortic root replacement is a serious complication and requires surgical reintervention with a high mortality rate. We report two cases of composite graft infection 3 months and 44 months after the primary operation. Each successfully underwent redo aortic root replacement with a new composite graft and a Freestyle stentless bioprosthesis, respectively. Both patients are currently well and without recurrence of infection 35 months and 48 months postoperatively.     

Aortoduodenal fistula following aortobifemoral bypass

A patient with a fistula between the aortic graft and the third portion of the duodenum was admitted in our institution and submitted to surgery that involved extra anatomical axillobifemoral bypass, prosthesis removal and bowel resection with a gastrojejunal Roux anastomosis. A prosthetic fistula after aortic surgery is a rare but potentially fatal complication. Erosion, infection and pseudoaneurysm are mechanisms in the pathogenesis of aortoenteric fistula. Because of the high mortality and morbidity, associated with secondary aortoenteric fistula, surgical treatment is always recommended. A combination of endoscopy and CT or MRI may offer the best chance of detecting a fistula, but the most important tool to achieve diagnosis is clinical suspicion. An aortoenteric fistula should always be suspected in all patients who have undergone aortic graft surgery and present with gastrointestinal haemorrhage. The authors discuss the modern management of this challenging complication of aortic surgery.     

Successful in situ treatment of an infected ascending aortic graft

Infection of an ascending aortic prosthesis is a grave complication associated with a high mortality. In most cases, extraanatomic bypass and removal of the infected vascular graft are not possible. Furthermore, the standard approach to this problem, which includes excision and replacement or debridement and repair of infected thoracic aortic grafts, carries a high early mortality. We report the successful treatment of this life-threatening complication using a conservative strategy in which the aortic prosthesis was salvaged by in situ disinfection followed by coverage with tissue flaps.     

A systematic review of infected descending thoracic aortic grafts and endografts

ObjectiveThe objective of this study was to collect and critically analyze the current evidence on the modalities and results of treatment of descending thoracic aortic surgical graft (SG) and endograft (EG) infection, which represents a rare but dramatic complication after both surgical and endovascular aortic repair.MethodsA comprehensive electronic health database search (PubMed/MEDLINE, Scopus, Google Scholar, and the Cochrane Library) identified all articles that were published up to October 2017 reporting on thoracic aortic SG or EG infection. Observational studies, multicenter reports, single-center series and case reports, case-control studies, and guidelines were considered eligible if reporting specific results of treatment of descending thoracic aortic SG or EG infection. Comparisons of patients presenting with SG or EG infection and between invasive and conservative treatment were performed. Odds ratio (OR) meta-analyses were run when comparative data were available.ResultsForty-three studies reporting on 233 patients with infected SG (49) or EG (184) were included. Four were multicenter studies including 107 patients, all with EG infection, associated with a fistula in 91% of cases, with a reported overall survival at 2 years of 16% to 39%. The remaining 39 single-center studies included 49 patients with SG infection and 77 with EG infection. Association with aortoesophageal fistula was significantly more common with EG (60% vs 31%; P = .01). In addition, time interval from index procedure to infection was significantly shorter with EG (17 ± 21 months vs 32 ± 61 months; P = .03). Meta-analysis showed a trend of increased 1-year mortality in patients with SG infection compared with EG infection (pooled OR, 3.6; 95% confidence interval, 0.9-14.7; P = .073). Surgical management with infected graft explantation was associated with a trend toward lower 1-year mortality compared with graft preservation (pooled OR, 0.3; 95% confidence interval, 0.1-1.0; P = .056).ConclusionsThoracic aortic EG infection is likely to occur more frequently in association with aortoesophageal fistulas and in a shorter time compared with SG infection. Survival is poor in both groups, especially in patients with SG infection. Surgical treatment with graft explantation seems to be the preferable choice in fit patients.     

Diagnosis of Graft Infection Using FDG PET-CT

Graft infections after aortic replacement are a rare, but severe complication. Because surgical removal of the infection source is essential, an accurate diagnosis is required to prevent unnecessary treatment. Both of the patients described herein were diagnosed with graft infections using dual-modality positron emission tomography-computed tomography; one patient was a false-positive, and the other was confirmed with an infection.     

Aortoduodenal Fistula Following Aortobifemoral Bypass

A patient with a fistula between the aortic graft and the third portion of the duodenum was admitted in our institution and submitted to surgery that involved extra anatomical axillobifemoral bypass, prosthesis removal and bowel resection with a gastrojejunal Roux anastomosis.

A prosthetic fistula after aortic surgery is a rare but potentially fatal complication.

Erosion, infection and pseudoaneurysm are mechanisms in the pathogenesis of aortoenteric fistula.

Because of the high mortality and morbidity, associated with secondary aortoenteric fistula, surgical treatment is always

recommended.

A combination of endoscopy and CT or MRI may offer the best chance of detecting a fistula, but the most important tool to achieve diagnosis is clinical suspicion. An aortoenteric fistula should always be suspected in all patients who have undergone aortic graft surgery and present with gastrointestinal haemorrhage. The authors discuss the modern management of this challenging complication of aortic surgery.     

Aortoiliac Stent Graft Infection: Current Problems and Management

Aortic stent graft infection is uncommon. Most cases have been described anecdotaly in single-case reports. After observing one case in our experience, we decided to review the literature and contact centers performing endovascular aortic repair to determine the frequency, risk factors, and current treatment of stent graft infection. The literature was reviewed and the authors of identified articles were contacted for further information. In addition, 40 centers specializing in endovascular treatment were contacted by means a dedicated questionnaire. A total of 65 aortic stent graft infections were identified, including 43 reported cases and 22 previously unpublished cases that were observed at specialized centers. Stent grafts were implanted in the aorta in 50 cases and in the iliac artery in 15 cases. The frequency of infection was 0.43%. The gender ratio was 4:1 (M:F). Twenty-three percent of patients had immunodeficiency factors. Placement was performed in an interventional radiology suite in 62.5% of cases and in a sterile operating theater in 37.5%. Also, 35.5% of patients underwent other vascular procedures during the course of study and 29.2% stent grafts benefited from adjuvant endovascular procedures. Infection was classified as low grade in 35.4% of patients and high grade in 64.6%. Thirty-one percent of infections were associated with aortoenteric fistula. The offending microorganism was Staphylococcus aureus in 54.5% of cases. Treatment was conservative in 18% of cases and surgical in 82%. Surgical treatment consisted of stent graft removal followed by either extraanatomical bypass (59.5%) or in situ prosthetic reconstruction (40.5%). Mortality was 18% overall, 36.4% after conservative treatment and 14% after surgical treatment (p = 0.083). Mortality was 16% after surgical treatment with extraanatomical bypass vs. 5.8% surgical treatment with in situ reconstruction. From these results we conclude that stent graft infection is an uncommon occurrence associated with poorly defined risk factors. Surgical treatment with complete excision of the infected stent graft followed by in situ reconstruction provides the best outcome. Establishment of a multicenter register to record such complications is needed to confirm the findings of this study.Presented at the Eighteenth Annual Meeting of the Société de Chirurgie Vasculaire de Langue Française, Toulouse, France, May 21â€24, 2003.     

Diagnosis and management of infected prosthetic aortic grafts

Infection of an aortic prosthetic graft represents one of the most difficult diagnostic and therapeutic challenges to the vascular surgeon. The presentation of this complication, the degree of ischemia of the lower extremities, and the overall medical status of the patient determine the urgency and optimal treatment to maximize limb salvage and survival. Although partial or total graft preservation can be a treatment option if the infection is localized to the distal limb of an aortofemoral graft and all anastomoses are intact, treatment of an infected aortic prosthetic graft often requires total graft excision, preferably preceded by revascularization of the lower extremities through lateral uninfected routes. Careful selection of the many time-honored and newly developed diagnostic and treatment modalities is necessary to lower morbidity and mortality rates in patients with this complication.     

Antibiotic-impregnated beads for the treatment of aortic graft infection

Infection of a prosthetic graft after replacement of the ascending aorta is an uncommon but life-threatening complication of surgery. We report the use of antibiotic-impregnated calcium sulfate beads in a patient with ascending aortic graft infection to provide localized, high-dose therapy to the infected region. Perigraft placement of antibiotic beads provides an alternative method for the treatment of aortic graft infection.     

Diagnosis of prosthetic aortic graft infection by magnetic resonance imaging

The accuracy of magnetic resonance imaging (MRI) in the diagnosis of prosthetic aortic graft infection was evaluated in 18 patients with history and findings suggestive of this complication. The prospective interpretation of MRI was compared with surgical findings. Sixteen patients had a graft infection verified at operation. Fourteen patients had infection of the retroperitoneal portion of the graft; two patients had an infection limited to one of the groins; no graft infection was found at surgical exploration in the remaining two patients. Perigraft infection was correctly diagnosed on the basis of MRI findings in 14 of 16 cases; findings were false negative in one case, questionable in another case, and correctly excluded graft infection in two of two cases. MRI also defined the extent of infection in 14 of 16 cases. MRI findings that supported the clinical suspicion of graft infection were perigraft fluid collections remaining more than 3 months after surgery. Furthermore, local inflammation was suggested by an increased signal intensity of adjacent muscle on T2-weighted images in some cases. CT scans were performed in 12 patients; these enabled a correct diagnosis in five and provided indeterminate or false information in seven. These results indicate that MRI is helpful in the diagnosis of aortic graft infection. Furthermore, MRI provides information about the extent of infection crucial for planning therapy.