Long-term follow-up after in situ graft replacement in patients with aortofemoral graft infections

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.

Open Conversion after Aortic Endograft Infection Caused by Colistin-Resistant, Carbapenemase-Producing Klebsiella pneumoniae

A 62-year-old man presented with fever, abdominal pain, and malaise 13 months after emergency endovascular aortic repair. Computed tomographic angiograms showed a periprosthetic fluid and gas collection, so infection was diagnosed. Open conversion was performed, involving endograft explantation and in situ aortic reconstruction. Cultures and the explanted prosthesis were positive for carbapenemase-producing Klebsiella pneumoniae, resistant to colistin. Because of the sparse data on endograft infections caused by this pathogen, we placed the patient on an empiric double-carbapenem regimen for 4 weeks. Symptomatic recovery occurred after 21 days. On the 30th day, we deployed a stent to treat a new pseudoaneurysm. Three years later, the patient had no signs of persistent or recurrent infection. We think that this is the first report of aortic endograft infection caused by colistin-resistant, carbapenemase-producing K. pneumoniae.

Preliminary Results from a National Enquiry of Infection in Abdominal Aortic Endovascular Repair (Registry of Infection in EVAR--R.I.EVAR)

BACKGROUND

To preliminary report on epidemiology, risk factors, diagnosis, treatments, and outcomes in a multicenter series of patients treated for endovascular aortic repair (EVAR) infection and detected by an Italian National enquiry.

METHODS

From June 2012, 26 cases of abdominal aortic endograft infection were collected by a National Enquiry and recorded in the Italian National Registry of Infection in EVAR. Cases collected were available for patients submitted to EVAR implantation from January 2004 to June 2013.

RESULTS

Mean time from EVAR treatment to infection diagnosis was 20.5 ± 20.3 months (range, 1-72). In 6 cases (23.1%), an aortoenteric fistula (AEF) was detected. Positive microbiologic cultures were found in 20 patients (76.9%). More than 1 infectious agent was found in 6 cases (19.2%). EVAR infection treatment was conservative in 4 cases, endovascular in 2. Endograft excision was performed in 10 cases by conventional treatment (aortic stump + extra-anatomic bypass) and in 10 cases by in situ reconstruction (cryopreserved allograft or rifampin-soaked silver Dacron graft). A 30-day mortality was 38.4% (10 of 26 cases), 3 patients died from 2 to 24 months after infection treatment, accounting for a mean time from infection treatment to death of 1.25 ± 0.62 months. Mortality rates were 50% in all treatment groups. In those survived (13 of 26 cases) recurrence-free follow-up after infection treatment was 27.9 ± 22.4 months (range, 2-74). Four patients with AEF died in the first month after treatment (66.6%). Suprarenal endografts required supraceliac aortic cross-clamping for removal. Supraceliac cross-clamping was burdened by higher mortality rates than infrarenal cross-clamping (71.4% vs. 30.7%).

CONCLUSIONS

EVAR infection diagnosis is burdened by extremely high mortality rates. Prospective registries could help monitoring outcomes in EVAR infection patients and, possibly, developing new surveillance protocols in patients at high risk of recurrence.

Medical treatment of prosthetic vascular graft infections: Review of the literature and proposals of a Working Group

More than 400000 vascular grafts are inserted annually in the USA. Graft insertion is complicated by infection in 0.5-4% of cases. Vascular graft infections (VGIs) are becoming one of the most frequent prosthesis-related infections and are associated with considerable mortality, ranging from 10 to 25% within 30 days following the diagnosis. Treatment of VGI is based on urgent surgical removal of the infected graft followed by prolonged antibiotherapy. Data regarding the best antibiotherapy to use are lacking since no well designed trial to study antimicrobial treatment of VGI exists. Moreover, since VGIs demonstrate very specific pathophysiology, guidelines on other material-related infections or infective endocarditis treatment cannot be entirely applied to VGI. A French multidisciplinary group gathering infectious diseases specialists, anaesthesiologists, intensivists, microbiologists, radiologists and vascular surgeons was created to review the literature dealing with VGI and to make some proposals regarding empirical and documented antibiotic therapy for these infections. This article reveals these proposals.

Infective Etiology Affects Outcomes of Late Open Conversion After Failed Endovascular Aneurysm Repair

Purpose: To retrospectively review all patients undergoing late open conversion (LOC) after endovascular aneurysm repair (EVAR) in order to identify any clinical or technical predictors of poor outcome. Methods: Twenty-six consecutive patients (24 men; mean age 74.7±8.3 years) underwent LOC between June 2006 and April 2013 at our institution. The mean interval from index EVAR to LOC was 40.4±29.2 months (range 5–93 months). The indication for LOC was endoleak in 14 (54%) patients and infection in 12 (46%): 2 (8%) patients with endoleak had a ruptured aneurysm and 6 (23%) patients with infection had a recurrent secondary aortoesophageal fistula (sAEF). Results: In all 12 cases of infection and in 12 of 14 endoleaks, the entire endograft was explanted. A rifampin-soaked Dacron silver graft was implanted in all patients with infection. Patients with any infection and with recurrent AEF required more blood units than patients with endoleak (6.40 vs. 1.86, p=0.045; 6.76 vs. 1.86, p=0.0036, respectively). Compared with endoleak, the duration of conversions in the setting of infection (274 vs. 316 minutes, p=0.42) and recurrent sAEF (274 vs. 396 minutes, p=0.021) was longer. All patients with recurrent sAEF died at a mean 3.0±2.5 days after LOC from proximal anastomosis disruption and hemorrhagic shock (n=2), myocardial infarction (n=2), acute stroke (n=1), or persistent sepsis (n=1). Perioperative mortality was significantly higher in patients with endograft infection (6/12, p=0.002) and in cases of supraceliac cross-clamping (4/6, p=0.003). The association of infection with supraceliac cross-clamping was a strong predictor for perioperative mortality (p<0.001). Conclusion: In our experience, endograft infection led to greater perioperative mortality after LOC. Recurrent aortoenteric fistula in association with supraceliac cross-clamping is a strong predictor of poor outcome. Patients surviving the perioperative period may have good chances of long-term survival.

Aortobipopliteal bypass grafting for in situ replacement of infected aortobifemoral prosthesis

Conventional treatment of an infected aortobifemoral graft includes total graft excision and ex situ bypass grafting, but has been associated with significant perioperative morbidity and mortality. Additionally, the presence of infection in the groin makes limb revascularization problematic. There is increasing evidence that in situ replacement of an infected graft can achieve promising results in selected patients. We present a case of an aortobifemoral graft infection, affecting both the groin as well as the entire pelvis. The patient underwent successful in situ graft replacement with a new aortobipopliteal prosthesis via an alternative extraperitoneal route.

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.