How to Occlude a Side Branch on a Branched Stent-Graft During an Endovascular Thoracoabdominal Aortic Aneurysm Repair

Plug-Based Embolization Techniques of Aortic Side Branches during Standard and Complex Endovascular Aortic Repair

Vascular plugs are an evolving family of vessel occluders providing a single-device embolization system for large, high-flow arteries. Nitinol mesh plugs and polytetrafluoroethylene membrane plugs are available in different configurations and sizes to occlude arteries from 3 to 20 mm in diameter. Possible applications during complex endovascular aortic procedures are aortic branch embolization to prevent endoleak or to gain an adequate landing zone, directional branch occlusion, and false lumen embolization in aortic dissection. Plugs are delivered through catheters or introducers, and their technical and clinical results are comparable to those of coil embolization. Plugs are more accurate than coils as repositionable devices, less prone to migration, and have fewer blooming artifacts on postoperative computed tomography imaging. Their main drawback is the need for larger delivery systems. This narrative review describes up-to-date techniques and technology for plug embolization in complex aortic repair.

Outcomes of off-the-shelf multibranched stent grafts with intentional occlusion of directional branches using endovascular plugs during endovascular repair of complex aortic aneurysms

OBJECTIVE

To evaluate the technique and outcomes of intentional occlusion of directional branches (DBs) using endovascular plugs during branched endovascular aortic repair using off-the-shelf Zenith t-Branch thoracoabdominal (TAAA) stent grafts.

METHODS

We reviewed the clinical data and outcomes of all consecutive patients treated by branched endovascular aortic repair using off-the-shelf Zenith t-Branch TAAA stent-graft (Cook Medical, Bloomington, Ind) in seven academic centers from 2013 to 2019. All patients had at least one DB intentionally occluded using extension of the branch with balloon or self-expandable covered stent, followed by placement of endovascular plugs. Intentional occlusion was indicated in patients with variations in the normal four-vessel renal-mesenteric anatomy, pre-existing dialysis, or in those who failed catheterization of a target vessel. End points were 30-day/in-hospital mortality, major adverse events, secondary interventions, target artery (TA) patency, TA instability, and patient survival.

RESULTS

There were 100 patients, 65 male and 35 female, with median age of 71 years (interquartile range [IQR], 66-75 years). Of these, 31 patients (31%) had urgent/emergent operations for symptomatic/contained ruptured aneurysms. The median aneurysm diameter was 72 mm (IQR, 61-85 mm). A total of 290 renal-mesenteric arteries were incorporated with a median of three (IQR, 3-3) vessels/patient. Indications for DB occlusion were less than four suitable renal-mesenteric targets in 84 patients or pre-existing dialysis and inability to catheterize a target vessel in eight patients each. There were 110 DBs occluded by vascular plugs, including 48 celiac axis, one superior mesenteric artery, and 61 renal DBs. Thirty-day/in-hospital mortality was 10%, including 9% for elective and 13% for urgent/emergent procedures. Major adverse events occurred in 44 patients (44%), including acute kidney injury in 19 patients (19%), estimated blood loss >1 L in 12 patients (12%), respiratory failure and new onset dialysis in six patients (6%) each, bowel ischemia in five patients (5%), and myocardial infarction and paraplegia in two patients (2%) each. The median follow-up was 5 months (range, 1-13 months). Eighteen patients (18%) required secondary interventions, none for problems related to the occluded DB. There were no endoleaks related to the occluded DB. At 2 years, primary and secondary patency and freedom from TA instability were 93% ± 3%, 97% ± 2%, and 91% ± 4%, respectively. Freedom from secondary interventions and patient survival were 75% ± 6% and 63% ± 7%, respectively.

CONCLUSIONS

Intentional occlusion of DBs using endovascular plugs allows versatile use of a four-vessel off-the-shelf multi-branched TAAA stent graft in patients with variations in the normal renal and mesenteric anatomy or when technical difficulties prevent successful target vessel stenting. There were no endoleaks or secondary interventions associated with the occluded DB.

Reversed and Antegrade Iliac Side Branch Stentgraft as an Alternative or Rescue Maneuver in Complex (Thoraco)Abdominal Endovascular Aortic Repair to Preserve Renal Perfusion

Purpose

To describe a technique that can preserve renal perfusion in failed bridging stent implantation of renal arteries or as intentional procedure in emergency cases, when the (thoraco)abdominal aneurysm anatomy does not meet the criteria for instructions for use of an “off-the-shelf” graft. The technique is based on reversed or antegrade integration of a standard iliac side branch graft into the aortic stentgraft system, which allows cannulation of (accessory) renal vessels.

Technique

A standard iliac side branch prosthesis is deployed and re-sheathed in reversed direction on the back table. The endograft is then implanted in the unibody in analogy to an iliac limb. The iliac side branch is cannulated followed by target vessel cannulation and covered bridging stents are deployed for completion. Furthermore, an iliac side branch prothesis can also be used to preserve relevant accessory renal arteries, when implanted in delivered antegrade loading position.

Conclusion

The use of a reversed and antegrade iliac side branch technique to revascularize renal vessels is feasible and safe in selected patients. This technique may also allow to extend the range of an “offthe- shelf” (multibranch) stentgraft, when immediate treatment is required.

Fenestrated and Branched Stent Grafting in Complex Aneurysmatic Aortic Disease: A Single-Center Early Experience

BACKGROUND

The aim of this study is to present our early experience and highlight the technical difficulties associated with the use of fenestrated and branched stent grafts to treat patients with juxtarenal abdominal aortic aneurysm (AAA), pararenal AAA, and thoracoabdominal aortic aneurysms (TAAAs).

METHODS

A prospectively held database maintained at our department was queried for patients who have undergone branched and fenestrated stent grafting for AAA or TAAA treatment. Indication for repair, comorbidity precluding open repair, technical challenges associated with the repair, as well as operative mortality, morbidity, and reintervention rate were evaluated.

RESULTS

A total of 8 patients underwent repair with a fenestrated or branched stent graft. All patients had aneurysmal degeneration of the juxtarenal aorta, pararenal aorta, and thoracoabdominal aorta not suitable to standard endovascular techniques. Two patients had a prior aortic repair, a failed migrated stent graft, and an old surgical tube graft after an open repair. One patient had a type III TAAA and 1 patient had a postdissection TAAA type I. For all patients, target vessel success rate was 96.4% (27/28) and mean hospital stay was 6.0 days (range 3-21). Thirty-day and 1-year mortality were 0%. Mean follow-up was 23 months (range 7-45). Two endoleaks occurred, 1 type III and 1 type II, which were treated endovascularly. No death or major complication occurred during follow-up.

CONCLUSIONS

Fenestrated and branched endovascular stent grafts can be used to repair juxtarenal AAA, pararenal AAA, and TAAA in patients with significant comorbidities. However, several technical challenges have to be overcome due to the unique complex aortic pathology of each patient.

Endovascular repair of thoracoabdominal aneurysms: results of the first 48 cases

BACKGROUND

In 2006, we began our experience with a novel technology for fully endovascular thoracoabdominal aneurysm repair, based on a custom-made, branched stent graft design. After 48 cases, we have learned and achieved substantial progress both in technical and in clinical skills. This paper describes the partial results of this ongoing experience.

METHODS

Patients in this series were selected for the presence of thoracoabdominal aortic aneurysms, with or without dissection, which was present in one patient. The observation of extensive anatomical variations in several patients prompted changes in many of the basic stent graft configurations, which are also described.

RESULTS

Between August 2006 and June 2012, 48 patients were treated consecutively with custom-made branch stent grafts. The five patients with the longest follow-up available so far are at 71, 65, 60, 54 and 51 months post-procedure. The operative mortality rate, defined as death during or within a month of surgical hospitalization, was 21% (10 patients); each case is described herein. During postoperative follow up, nine patients died from causes not directly related to aneurysmal disease, at 3, 18, 20, 22, 24, 24, 37, 44 and 46 months. The main causes of death were myocardial infarction (four cases), cancer (two cases), gastrointestinal hemorrhage (one case), ischemic stroke (one case), and sepsis (one case). Permanent paraplegia occurred in one patient.

CONCLUSIONS

It is still too soon to compare the results of endovascular repair of thoracoabdominal aneurysms with those of open surgical series. Despite the active and rapid progress currently observed for the endovascular method, it is still far from reaching its state-of-the-art plateau or becoming a gold standard. Further technological and technical advances in endovascular stent grafting seem to have a clear potential to provide very satisfactory operative outcomes for thoracoabdominal aortic aneurysms.