Maximizing Proximal Seal Zone in Fenestrated Endografting: Evolution in the Approach to Graft Configuration

Abstract

This study examined the proximal seal length afforded by varying configurations of the Zenith fenestrated graft (ZFEN; Cook Medical, Bloomington, Ind). The most common configuration in the pivotal trial and in early postapproval use was a scallop for the superior mesenteric artery (SMA) and two small fenestrations for the renal arteries (configuration A). An alternative configuration, consisting of a large fenestration for the SMA and two small fenestrations for the renals (configuration B), has been routinely adopted at many institutions. From 2012 to 2019 at two university centers, 100 consecutive ZFEN grafts were designed for patients. The proximal seal length, from the top of the graft to the beginning of the aneurysm, was determined from preoperative computed tomography angiography. Alternative configurations were evaluated to determine whether they would have provided longer proximal seal. The two most common configurations were B (n = 45) and A (n = 38). In cases in which A was chosen but B could have been built, 5.8 ± 1.9 mm of seal zone was lost; in cases in which B was chosen but A could have been built, 5.8 ± 2.8 mm of seal zone was gained. Configuration B has been used more frequently in the last 4 years of this experience compared with the first 4 years (53% vs 25%; P = .004). Of 92 patients who have completed surgery and follow-up, type IA endoleaks were observed in 12 patients (13%) on completion angiography, all of which resolved on follow-up imaging without intervention. No SMA was compromised by misalignment of the large fenestration in configuration B. The Table provides details. Significantly more proximal seal length can be obtained using a ZFEN with a large fenestration for the SMA and two small fenestrations for the renals. Whenever possible, surgeons should consider this configuration to maximize proximal seal length and potentially reduce the risk of proximal endoleak. Stenting of the SMA to prevent shuttering is unnecessary or impossible using a large fenestration, making the procedure more technically facile.TableProximal seal length and endoleaks of graft configurationsNo.Configuration A, No.Proximal seal length, mmConfiguration B, No.Proximal seal length, mmOther configurations, No.Overall experience1003826.7 ± 6.14527.4 ± 6.8a17Early experience251325.7 ± 6.0527.8 ± 6.5a7Late experience752527.2 ± 6.14027.3 ± 6.9a10bConfiguration AConfiguration BOther configurationsType IA endoleak on completion angiography6/36 (10%)4/41 (10%)2/15 (13%)cType IA endoleak on last follow-up imaging study0/360/410/15aNot significant comparing seal length between configurations A and B during relevant time period, by t-test.bP = .01 comparing distribution of configurations during early and late experiences, by Fisher exact test.cNot significant comparing type IA endoleaks on completion angiography between configurations, by Fisher exact test. Open table in a new tab