Meticulous planning, creativity key to management of EVAR infections

The expert opinion from the Northwestern Vascular Symposium regarding the management of EVAR infections reminds us of the importance of appropriate patient selection, proper performance of the planned procedure, and long-term follow-up. As EVAR has become the treatment of choice for more than 80% of patients with infrarenal AAAs in the United States, the rate of patients that return with EVAR infections, although rare, is increasing and their management can be more challenging than that of a primary or aortic graft infection as suggested by Dr. Thomas C. Bower in this opinion. The planning for these cases is critical with multiple options for treatment currently available and endorsed by a variety of investigators. From an evaluation standpoint, CTA is critical for diagnosis and case planning. Air around the graft is considered the “sine qua non” of infection but if it presents in the first month after EVAR it can be due to trapped air introduced into the sac during the intervention.

Dr. Luis A. Sanchez

Patients with air in the sac at the initial postprocedure evaluation should be considered for early follow-up to make sure this finding resolves. Further assessment that will change the management of the patient includes the type of EVAR device, infra- or suprarenal, since the entire removal of a suprarenal device usually requires supraceliac cross-clamping with its associated morbidity and mortality. Drainage of the infected cavity, as suggested by Dr. Bower, can help lower the bacterial burden and provide information regarding the offending organism. That information will help the vascular surgeon decide if an in-line reconstruction or an extra-anatomical one is more appropriate in the patient’s situation as more virulent organisms tend to be associated with higher reinfection and complication rates when in-line reconstructions are performed.

The different options for aortic access need to be evaluated based on the anatomy of the patient. A transabdominal approach is best for most patients as it allows access to the iliac arteries bilaterally for removal of the entire graft, debridement of the infected bed, aortic and/or visceral reconstruction, and omental coverage of the in-line graft or aortic stump if an extra-anatomical reconstruction is selected. The retroperitoneal approach should be considered for patients that will require extensive perivisceral work, as may be necessary from suprarenal or fenestrated devices, but limitations exist accessing the right iliac system and potentially intraabdominal targets for visceral or renal reconstructions.

The best configuration to reconstruct these patients remains largely undetermined based on the literature. The published experience from the Mayo Clinic (J. Vasc. Surg. 2013;58:371-9), in which some of the opinions of Dr. Bower are based, suggested excellent results in 24 patients mostly treated with rifampin-soaked in-line reconstructions with a periprocedural mortality of 4%. Cryopreserved aortic grafts “have become the conduit of choice for the group at this time,” stated Dr. Bower, to try to further decrease the reinfection rates in their patient population. There are limited data regarding the use of cryopreserved aortoiliac segments for aortic infections and less for EVAR infections. The most recent and largest series (J. Vasc. Surg. 2014;59:669-74) included 220 patients with aortic infections with a perioperative mortality of 9% and cryopreserved graft complications in another 12%-15% of patients.

In summary, aortic infections associated with EVAR are challenging problems that should be addressed in regional centers with experience. Renal and visceral reconstructions as well as supravisceral clamping are associated with significantly higher periprocedural morbidity and mortality based on the extensive experience at the Cleveland Clinic with EVAR explants (J. Vasc. Surg. 2014;59:886-93). The choice of the reconstruction and the material used should be based on the offending organism, type of EVAR device, extent of the infectious process, and the expertise of the treating physician.

Dr. Luis A. Sanchez is chief, section of vascular surgery and Gregorio A. Sicard Distinguished Professor of Surgery and Radiology, Washington University, St. Louis, and an associate medical editor for Vascular Specialist. He had no relevant disclosures.