Association of Baseline Chronic Kidney Disease Stage With Short- and Long-Term Outcomes After Fenestrated Endovascular Aneurysm Repair

BACKGROUND

Fenestrated endovascular aneurysm repair (FEVAR) is a well-established treatment approach for juxtarenal and short-neck infrarenal aortic aneurysms. Recommendations and clinical outcomes are lacking for offering FEVAR in patients with chronic kidney disease (CKD). We aimed to compare short- and long-term outcomes for patients with none-to-mild versus moderate-to-severe CKD undergoing FEVAR.

METHODS

We retrospectively reviewed consecutive patients undergoing standard FEVAR with Cook devices at a single institution. The cohort was stratified by preoperative CKD stage none-to-mild or moderate-to-severe (CKD 1-2 and CKD 3-5, respectively). The primary outcome was postoperative acute kidney injury (AKI). Secondary outcomes included 30-day perioperative complications, 1- and 5-year rates of overall survival, dialysis, renal target artery patency, endoleak, and reintervention assessed by the Kaplan-Meier method. Aneurysm sac regression, number of surveillance computed tomography (CT) scans, and CKD stage progression were assessed at latest follow-up. Multivariate Cox proportional hazards modeling was used to evaluate the association of CKD stage 3 and stage 4-5 with all-cause mortality, controlling for differences in baseline characteristics.

RESULTS

From 2012- to 2022, 184 patients (of which 82% were male) underwent FEVAR with the Cook ZFEN device (mean follow-up 34.3 months). Group CKD 3-5 comprised 77 patients (42%), was older (75.2 vs. 73.0 years, P = 0.04), had increased preoperative creatinine (1.6 vs. 0.9 mg/dL, P < 0.01), and demonstrated increased renal artery ostial calcification (37.7% vs. 21.5%, P = 0.02) compared with Group CKD 1-2. Perioperatively, CKD 3-5 sustained higher estimated blood loss (342 vs. 228 ml, P = 0.01), longer operative times (186 vs. 162 min, P = 0.04), and longer length of stay (3 vs. 2 days, P < 0.01). Kaplan-Meier 1- and 5-year survival estimates were lower for CKD 3-5 (82.3% vs. 95.1%, P < 0.01 and 55.4% vs. 70.8%, P = 0.02). Fewer CKD 3-5 patients remained free from chronic dialysis at 1 year (94.4% vs. 100%, P = 0.015) and 5 years (84.7% vs. 100%, P < 0.01). There were no significant differences in postoperative AKI rate (CKD 1-2 6.5% vs. CKD 3-5 14.3%, P = 0.13), long-term renal artery patency, reinterventions, type I or III endoleak, mean sac regression, or total follow-up CT scans between groups. CKD stage progression occurred in 47 patients (31%) at latest follow-up but did not differ between stratified groups (P = 0.17). On multivariable modeling, age (hazard ratio 1.05, 95% confidence interval 1.01-1.09, P = 0.02) and CKD stage 4-5 (hazard ratio 6.39, 95% confidence interval 2.26-18.05, P < 0.01) were independently associated with mortality.

CONCLUSIONS

Preoperative CKD status did not negatively impact the durability or technical success related to aneurysm outcomes after FEVAR. Worsening CKD stage was associated with lower 1- and 5-year overall survival and freedom from dialysis after FEVAR with no statistically significant differences in 30-day or long-term technical aneurysm outcomes.

A fenestrated, double-barrel technique for proximal reintervention after open or endovascular abdominal aortic aneurysm repair

Objective

Proximal endovascular reintervention after prior endovascular aortic repair (EVAR) or open abdominal aortic aneurysm repair (OR) can be challenging due to the short distance to the visceral branches. We present a novel solution to allow the use of the commercially available ZFEN device using a double-barrel, kissing-limb technique.

Methods

Patients who underwent fenestrated repair for proximal failure after EVAR or OR were identified. The ZFEN device is deployed above the prior graft flow divider. Once the visceral branches are secured, kissing limbs are used to connect with the prior graft limbs. The distal diameter of the standard ZFEN is 24 mm, accommodating two 20 mm components according to the formula 2πD_LIMB = πD_ZFEN + 2D_ZFEN.

Results

Of 235 patients who underwent repair using ZFEN from 2012 to 2021 at a single institution, 28 were treated for proximal failure of prior repairs, with 13 treated using the double-barrel technique (8 EVAR, 5 OR). The distance from the flow divider to the lowest renal artery was 67 ± 24.4 mm (range, 39-128 mm), and the distance to the superior mesenteric artery (SMA) was 87 ± 30.5 mm (range, 60-164 mm). Technical success was 100%. Seven patients had standard ZFEN builds (2 renal small fenestrations, SMA large fen/scallop). The minimum distance to the lowest renal artery and SMA to accommodate a standard ZFEN build was 56 and 60 mm, respectively. Four patients required adjunctive snorkel grafts and two required laser fenestrations. Two patients had gutter leaks at 1 month that self-resolved; one patient developed a late type 1a endoleak. Freedom from reintervention was 90%, 72%, and 48% at 1, 2, and 3 years, respectively.

Conclusions

This double-barrel technique allows for distal seal of commercial ZFEN devices into prior open or endovascular repairs with good technical success. Long-term outcomes remain to be quantified.

Large Fenestrations Versus Scallops for the SMA During Fenestrated EVAR: Does it Matter?

OBJECTIVE

FEVAR is an established customized treatment for aortic aneurysms with three current commercially available configurations for the superior mesenteric artery (SMA) - a single-wide scallop, large fenestration, or small fenestration, with the scallop or large fenestration most utilized. Outcomes comparing SMA single-wide scallops to large fenestrations with the ZFEN device are scarce. As large fenestrations have the benefit of extending the proximal seal zone compared to scalloped configurations, we sought to determine the differences in seal zone and sac regression outcomes between the two SMA configurations.

METHODS

We retrospectively reviewed our prospectively maintained complex EVAR database and included all patients treated with the Cook ZFEN device with an SMA scallop or large fenestration configuration at its most proximal build. All first post-operative CT scans (1-30 days) were analyzed on TeraRecon to determine precise proximal seal zone lengths, and standard follow-up anatomic and clinical metrics were tabulated.

RESULTS

A total of 234 consecutive ZFEN patients from 2012-2021 were reviewed, and 137 had either a scallop or large fenestration for the SMA as the proximal-most configuration (72 scallops and 65 large fenestrations) with imaging available for analysis. Mean follow-up was 35 months. Mean proximal seal zone length was 19.5±7.9 mm for scallop vs 41.7±14.4 mm for large fenestration groups (P<.001). There was no difference in sac regression between scallop and large fenestration at one year (10.1±10.9 mm vs 11.0±12.1, P = 0.63). Overall, 30-day mortality (1.3% vs 2.5%, P=.51) and all-cause three-year mortality (72.5% vs 81.7%, P=.77) were not significantly different. Reinterventions within 30 days were primarily secondary to renal artery branch occlusions, with only one patient in the scallop group requiring reintervention for an SMA branch occlusion.

CONCLUSIONS

Despite attaining longer proximal seal lengths, large SMA fenestrations were not associated with a difference in sac regression compared to scalloped SMA configurations at one-year follow up. There were no significant differences in reinterventions or overall long-term survival between the two SMA strategies.

Reintervention Does Not Impact Long-term Survival After Fenestrated Endovascular Aneurysm Repair

OBJECTIVES

Fenestrated endovascular aneurysm repair (FEVAR) is increasingly used in the treatment of juxtarenal aortic aneurysms and short-neck infrarenal aneurysms. Reinterventions (REIs) occur frequently, contributing to patient morbidity and resource utilization. We sought to determine if REIs impact long-term survival after FEVAR.

METHODS

A single-institution retrospective review of all Cook ZFEN repairs was performed. Patients with ≥6 months follow-up and without adjunctive branch modifications were included. REI was defined as any aneurysm, device, target branch, or access-related intervention after the index procedure. REIs were categorized by early (<30 days) or late (≥30 days), indication (branch, endoleak, limb, access-related, or other), and target branch/device component. Patients were stratified into REI vs No REI and Branch REI vs Non-Branch REI.

RESULTS

Of 219 consecutive ZFEN from 2012-2021, 158 patients met inclusion criteria. Forty-one (26%) patients underwent a total of 51 REIs (10 early, 41 late) over a mean follow-up of 33.9 months. The most common indication for REI was branch-related 61% (31/51), with the renal arteries most frequently affected 51% (26/51). The only differences found in baseline, aneurysm, or device characteristics were a higher mean SVS comorbidity score (9.6 vs 7.9, P=.04) and larger suprarenal neck angle (23.3 vs 17.1 degrees, P=.04) in No REI, while REI had larger mean proximal seal zone diameter (26.3 vs 25.1 mm, P=.03) and device diameter (31.9 vs 30.0 mm, P=.002) than No REI. Technical success and operative characteristics were similar between groups, except for longer mean fluoroscopy time (74.9 vs 60.8 min, P=.01) and longer median length of stay (2 vs 2 days, P=.006) in REI. While the rate of early major adverse events (<30 days) was higher in REI (24.4% vs 6.0%, P=.001), 30-day mortality was not statistically different (4.9% vs 0.9%, P=.10). On Kaplan-Meier analysis, freedom from REI at 1- and 5-years was 85.7% and 62.6%, respectively, in the overall cohort. There was no difference in estimated 5-year survival between REI and No REI (62.8% vs 63.5%, log-rank P=.87) and Branch REI and Non-Branch REI (71.8% vs 49.9%, log-rank P=.16). In multivariate analysis, REI did not predict mortality; age, the SVS comorbidity score, and preoperative maximum aneurysm diameter each increased the hazard of death (HR 1.07 95% CI 1.02-1.12, P=.007; HR 1.10, 95% CI 1.01-1.18, P=.02; HR 1.05, 95% CI 1.02-1.08, P=.003 respectively).

CONCLUSIONS

Following ZFEN, 26% of patients required a total of 51 REIs with most occurring ≥30 days and 61% being branch-related, with no influence on 5-year survival. Age, comorbidity, and baseline aneurysm diameter independently predicted mortality. FEVAR mandates lifelong surveillance and protocols to maintain branch patency. Despite their relative frequency, REIs do not influence 5-year post-procedural survival.