Superior mesenteric artery outcomes after large fenestration strut relocation with the Zenith Fenestrated endoprosthesis

Use of physician-modified inverted limb in conjunction with Zenith fenestrated stent graft to rescue failed previous endovascular and open repair

OBJECTIVE

To evaluate outcomes and performance of inverted limbs (ILs) when used in conjunction with Zenith fenestrated stent grafts (Zfens) to treat patients with short distance between the lowest renal artery (RA) and aortic or graft bifurcation (A/GB).

METHODS

This study was a multicenter, retrospective review of prospectively maintained database of patients with complex aortic aneurysms, failed endovascular aneurysm repair (EVAR), or open surgical repair (OSR) with short distance between LRA and A/GB treated using a combination of Zfen and an IL between 2013 and 2023. Endpoints included technical success, aneurysm sac regression, long-term device integrity, and target vessel patency. We defined technical success as implantation of the device with no endoleak, conversion to an aorto-uni-iliac or OSR.

RESULTS

During this time, 52 patients underwent endovascular rescue of failed repair. Twenty (38.5%) of them required relining of the failed repairs using IL due to lowest RA to A/GB length restrictions. Two patients had undergone rescue with a fenestrated cuff alone but developed type III endoleaks. One patient with no previous implant had a short distance between the lowest RA and aortic bifurcation to accommodate the bifurcated distal device, and two patients had failed OSR or anastomotic pseudoaneurysms. The majority (94%) were men with a mean age of 76.8 ± 6.1 years. The mean aortic neck diameter and aneurysm size were 32 ± 4 cm and 7.2 ± 1.3 cm, respectively. The median time laps between initial repair and failure was 36 months (interquartile range [IQR], 24-54 months). Sixteen patients (80%) were classified as American Society of Anesthesiologists class III, whereas four were class IV. Seventy-eight vessels were targeted and successfully incorporated. Technical success was 100%, and median estimated blood loss was 100 mL (IQR, 100-200 mL). Mean fluoroscopy time and dose were 61 ± 18 minutes and 2754 ± 1062 mGy, respectively. Average hospital length of stay was 2.75 ± 2.15 days. Postoperative complication occurred in one patient who required lower extremity fasciotomy for compartment syndrome. At a median follow-up of 50 months (IQR, 18-58 months), there were no device migration, components separation, aneurysmal related mortality, and type I or type III endoleak. Aneurysm sac regression (95%) or stabilization (5%) was observed in all patients, including in four patients (25%) with type II endoleak.

CONCLUSIONS

The use of IL in conjunction with Zfen to treat patients with short distance between the lowest RA and A/GB is safe, effective, and has excellent long-term results. The technique expands the indication of Zfen, especially in patients with failed previous EVAR.

Anatomical characteristics associated with superior mesenteric artery stent graft placement during fenestrated para/suprarenal aneurysm repair

OBJECTIVE

According to instructions for use, fenestrated aneurysm repair (FEVAR) with the Cook Zenith fenestrated endograft (ZFEN) requires at least 4 mm of non-aneurysmal infra-renal neck length and superior mesenteric artery (SMA) stenting is optional. This study evaluates the outcomes of FEVAR with SMA stent grafting relative to SMA scallops or unstented fenestrations and anatomical differences there-in.

METHODS

Single-institution retrospective analysis of patients who underwent FEVAR with SMA scallop or large fenestration with and without SMA stent grafting from June 2012 to May 2020 following Institutional Review Board approval.

RESULTS

Of the 203 aneurysms repaired with ZFENs, 127 were included in our analysis with 55 stent grafted SMA fenestrations, 38 unstented SMA fenestrations and 34 SMA scallops. Technical success was achieved in all patients. Operative times were longer (335.5 ± 16.4 vs 265.0 ± 12.8 vs 269.0 ± 12.7 mins, p < 0.001) and transfusion rates were higher (33% vs 8% vs 18%, p = 0.01) in the SMA stent graft group but fluoroscopy time (65.4 ± 3.76 vs 58.3 ± 3.94 vs 51.4 ± 4.75 mins, p = 0.05) and contrast volume (92.2 ± 5.17 vs 87.1 ± 6.73 vs 93.1 ± 5.89 mL, p = 0.84) were not significantly different. Anatomically, patients that underwent ZFEN with SMA stent grafting had less infrarenal neck (1.73 ± 1.18 vs 4.92 ± 1.16 vs 6.28 ± 1.42 mm, p = 0.03) and shorter infra-SMA neck length (10.3 ± 1.39 vs 23.9 ± 1.24 vs 26.8 ± 1.67 mm, p < 0.001). In the SMA stent graft group, 1 had small bowel necrosis following embolization of an intra-operatively perforated jejunal branch and 2 had colonic ischemia of unclear etiology with patent SMA stent grafts on imaging. Endograft migration and SMA occlusion with bowel ischemia occurred in 1 patient in the SMA fenestration group. Overall mortality (24% vs 21% vs 18%, p = 0.82) and 30-day mortality (5% vs 3% vs 3%, p = 0.80) were comparable between the 3 groups. In addition, the incidence of type 3 endoleak (5% vs 3% vs 3%, p = 0.45) and need for re-intervention (20% vs 18% vs 12%, p = 0.60) were similar across all groups. Mean follow-up duration was longer in the SMA scallop group which can be attributed to 82% of these occurring in the first half of the study period.

CONCLUSION

Despite the added technical complexity, SMA stenting enables FEVAR in patients with pararenal and suprarenal aneurysms with high rates of technical success and no increased risk of mortality, major adverse events, type 3 endoleak, or re-intervention.