Lessons learned and learning curve of fenestrated and branched endografts

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

Background

The Zenith® Fenestrated (ZFen) stent-graft is frequently configured with a strut-spanning large fenestration for superior mesenteric artery (SMA) incorporation. This has led some to relocate struts to create a strut-free fenestration and place a bridging stent. The aim of this study was to compare SMA outcomes with and without large fenestration strut relocation.

Methods

We performed a retrospective review of a prospective database of patients undergoing fenestrated endovascular repair with ZFen between 2013 and 2019. Those with SMA incorporation using large fenestrations were included and separated into strut relocation (SR) and no relocation (NR) groups. Endpoints included procedural metrics, technical success, major adverse events, and target-vessel instability.

Results

A total of 121 patients (77% male; mean age 76.1 ± 7.1 years) met inclusion criteria, including 94 with SR (78%) and 27 with NR (22%). A total of 369 target-vessels were incorporated, with a mean of 3.0 ± 0.2 per patient, and no differences between groups. Mean operative time, contrast volume, estimated blood loss, fluoroscopy time and radiation dose were lower (p < 0.001) with SR, attributed to increased experience with time. Overall technical success (SR: 100%, NR: 96%, p = 0.22) was 99%. At a mean follow-up of 32 months, there were two endovascular interventions for mesenteric ischemia. One resulted in SMA dissection requiring bypass in the NR group, the other was successful ballooning of the bridging stent with symptom resolution in the SR group.

Conclusions

Relocating the spanning struts does not negatively impact procedural metrics or midterm outcomes. It may facilitate future endovascular interventions.

Should endovascular approach be considered as the first option for thoraco-abdominal aortic aneurysms?

Open surgical repair has been the gold standard for treatment of thoracoabdominal aortic aneurysms (TAAAs). The technique of open TAAA repair has evolved from the use of "island" patch incorporation to separate branch vessel bypass, from "clamp and go" to routine use of distal perfusion, and towards more extensive repair in patients with connective tissue disorders. Open TAAA repair can be done with excellent results in highly specialized centers. However, these operations continue to carry excessive risk when performed outside large aortic centers, with 30-day mortality estimated on 20% according to statewide and national databases. In octogenarians, the mortality of elective open TAAA repair can be up to 40%. Endovascular repair was introduced as an alternative to open surgical repair in the elderly or higher risk patients using hybrid reconstruction, parallel grafts or fenestrated and branched endografts. Several large aortic centers have developed dedicated clinical programs to advance techniques of fenestrated-branched endovascular repair using patient-specific and off-the-shelf devices, offering a minimally invasive alternative to open repair allowing treatment of increasingly older and sicker TAAA patients. During the last decade, improvements in device design, patient selection, spinal cord injury protocols, and perioperative management have contributed to a continued decline in morbidity and mortality of fenestrated-branched endovascular aortic repair, challenging open surgical repair as the new "gold standard" for treatment of TAAAs. Despite the improved results, endovascular repair is a highly technical procedure that requires vast experience, involves a significant risk of complications, and also, has an impact on patients' physical quality of life. In this article, we review the current technical aspects of endovascular TAAA repair with the main focus on the evidence of open versus endovascular outcomes of TAAA repair.

Select type I and type III endoleaks at the completion of fenestrated endovascular aneurysm repair resolve spontaneously

OBJECTIVE

The Society for Vascular Surgery reporting standards for endovascular aneurysm repair (EVAR) consider the presence of a type I or type III endoleak a technical failure. However, the nature and implications of these endoleaks in fenestrated EVAR (FEVAR) are not well understood.

METHODS

We performed a single-center retrospective review of 53 patients who underwent FEVAR with the Zenith Fenestrated AAA Endovascular Graft (Cook Medical, Bloomington, Ind) from 2013 to 2018. We excluded one patient without contrast-enhanced postoperative imaging who was lost to follow-up after discharge. Small, slow, type I and type III endoleaks on completion angiography were routinely observed. We identified patients with completion type I or type III endoleaks by angiography review and characterized endoleak type, location, and rate of resolution on initial postoperative imaging.

RESULTS

Fifty-two patients were included; mean age was 75 ± 8 years, 75% were male, and 91% were white. Of 146 visceral vessels (100 renal arteries and 46 superior mesenteric arteries), 145 (99%) were preserved with 103 fenestrations and 43 scallops; 102 (70%) target vessels were stented. After implantation of all device components, 31 patients (60%) had evidence of type I or type III endoleak. Twelve patients (39%) underwent further intervention at the index procedure, and three endoleaks resolved completely. Twenty-eight patients (54%) had a type I or type III endoleak on completion angiography. There were no differences between patients with and without completion endoleaks in baseline demographics, graft design, neck anatomy, or proportion of cases performed within the instructions for use of the device. Perioperative mortality was 1.9%. On initial postoperative imaging, 27 of 28 (96%) endoleaks resolved spontaneously. One small, persistent type IA or type III endoleak was identified on postoperative day 27 and was observed. This endoleak had resolved completely on computed tomography angiography 6 months postoperatively. In patients without a completion endoleak, one type IA endoleak secondary to graft infolding was discovered on postoperative imaging and was successfully treated with placement of endoanchors and Palmaz stent. Median follow-up was 269 days. No additional type I or type III endoleaks were identified in any patient for the duration of follow-up.

CONCLUSIONS

Whereas completion type I and type III endoleaks are common after FEVAR with the ZFEN device, nearly all of these endoleaks resolve spontaneously by the initial postoperative imaging. These results suggest that select completion endoleaks after FEVAR with the ZFEN device do not require intervention at the index procedure.