Branched Stent-Grafts: Will These Become the New Standard?

Complete Endovascular Reconstruction of the Canine Ascending Aorta, Aortic Arch, and Supra-Aortic Vessels by Implanting a New Unibody Outer Double-Branched Stent-Graft

PURPOSE

We evaluated the feasibility and safety of using a new unibody outer double-branched stent-graft system to reconstruct the canine ascending aorta, aortic arch, and supra-aortic vessels.

MATERIALS AND METHODS

The outer-branched stent-graft was a unibody design. The branched stent-graft consisted of a main stent-graft and 2 branches. The introducer system included a tri-channel catheter, 2 detachable sleeves, a front fixing device, a constraining wire, and a curved outer sheath. The branched stent-graft was loaded into the introducer system. Ten adult mongrel dogs underwent general anesthesia, and the branched stent-grafts were deployed into the canine ascending aorta, aortic arch, and supra-aortic vessels by the introducer system. All animals were followed up for 3 months. At the end of the follow-up period, computed tomographic angiography (CTA) was performed to observe the patency of the branched stent-grafts.

RESULTS

The mean operation time was 142.7±13.7 minutes. The mean fluoroscopy time was 20.73±2.22 minutes. The mean dosage of contrast agent was 95.9±8.7 mL. During the operation, the tri-channel catheters successfully paralleled the wires in the aorta. All 10 branched stent-grafts were successfully implanted into the canine ascending aorta and aortic arch. There were no symptoms of cerebral embolization and no incision infection during the follow-up period. Computed tomographic angiography and specimens showed that the branched stent-grafts and native vessels were patent, the inner surfaces of the branched stent-grafts were covered by neointima, and there was no retrograde aortic dissection in the ascending aorta.

CONCLUSIONS

This animal research demonstrated that the unibody outer double-branched stent-graft system could be applied to reconstruct the canine ascending aorta, aortic arch, and supra-aortic vessels.

CLINICAL IMPACT

Thoracic endovascular aortic repair has been the main treatment method for aortic aneurysms or dissections involving the descending thoracic aorta. However, the aortic arch and ascending aorta remain the last segments of the aorta without a validated and routinely used endovascular option. In this research, we designed a new unibody outer branched stent-graft system to reconstruct the distal ascending aorta, aortic arch and supra-aortic vessels. The unibody outer branched stent-graft system could be applied to treat aortic pathologies which involve the middle and distal proximal ascending aorta, aortic arch and proximal descending aorta.

A canine model of aortic arch aneurysm created with autologous pericardium

Background

To establish a canine model of aortic arch aneurysm that is suitable for research on new devices and techniques applied to the aortic arch.

Materials and methods

Fifteen mongrel dogs underwent surgery. The autologous pericardial patch was sewn on the aortotomy site in the anterior wall of the aortic arch. The animals were followed up for 3 months postoperatively. Computed tomography angiography was used to visualize and measure the aneurysm model. Hematoxylin and eosin staining was used to observe the histological characteristics of the aneurysm model. Changes in aneurysm diameter over time were analyzed using analysis of variance.

Results

One dog died of hemorrhage during surgery. Fourteen dogs survived the surgical procedure. Two of them died on the first postoperative day because of ruptures at the suturing margin. The diameter of the aneurysm model was twice as large as that of the aortic arch. There was no significant change in the maximum diameter of the aneurysm model during the follow-up period.

Conclusions

We established a controllable and stable aortic arch aneurysm model created with an autologous pericardium patch. The aneurysm model can be used to research endoleaks after thoracic endovascular aortic repair and new endovascular techniques can be applied to the aortic arch.

Long-term durability of multibranched endovascular repair of thoracoabdominal and pararenal aortic aneurysms

OBJECTIVE

The objective of this study was to assess the durability of multibranched endovascular repair of thoracoabdominal aortic aneurysms (TAAAs) and pararenal aortic aneurysms by examining the rates of late-occurring (beyond 30 days) complications.

METHODS

There were 146 patients who underwent endovascular TAAA repair using a stent graft, with a total of 538 caudally oriented self-expanding branches. Four patients died in the perioperative period and were excluded, leaving 142 patients (mean age, 73 ± 8 years; 35 [24.7%] women). Follow-up included clinical examination and computed tomography angiography at 1 month, 6 months, and 12 months and yearly thereafter.

RESULTS

Mean aneurysm diameter was 67 ± 9 mm. Sixty-seven TAAAs (47.2%) were Crawford type I, II, III, or V; 75 (52.8%) were type IV or pararenal. Three patients (2.1%) died >30 days after operation from perioperative complications. During a mean follow-up of 36 months (±28 months), there were four additional aneurysm-related deaths: one (0.7%) as a result of aneurysm rupture in the presence of untreatable type I endoleak, one (0.7%) after conversion to open repair for stent graft infection, one (0.7%) after occlusion of superior mesenteric artery and celiac branches, and one (0.7%) due to bilateral renal branch occlusion. There was one additional open conversion for stent graft infection (0.7%). Nineteen patients (13.3%) underwent 20 reinterventions for late-occurring complications, including 11 (7.7%) for renal branch occlusion or stenosis, 1 (0.7%) for mesenteric branch stenosis, 4 (2.8%) for graft limb occlusion, 1 (0.7%) for type IB endoleak (distal stent graft migration), and 1 (0.7%) for type III endoleak (fabric erosion); 2 (1.4%) open conversions were performed for stent graft infection. There were no late type IA endoleaks. By Kaplan-Meier analysis, freedom from aneurysm-related death was 91.1% and freedom from aneurysm-related death or reintervention was 76.8% at 5 years. The 5-year overall survival rate of 49.1% reflects the high rate of cardiopulmonary comorbidity. Although renal branch occlusion (23 occlusions of 256 renal branches [8.9%]) was the most common late complication, only five patients required permanent dialysis.

CONCLUSIONS

Total endovascular repair of TAAAs and pararenal aortic aneurysms using axially oriented cuffs is safe, effective, and durable in the long term.

Open repair management of a patient with aortic arch saccular aneurysm, penetrating atherosclerotic ulcer, one vessel coronary artery disease and an isolated dissection of the abdominal aorta

Isolated saccular compared to fusiform aneurysm is considered to be a rare entity with challenges of its own. A 62-year-old female was diagnosed with a case of saccular aneurysm and penetrating atherosclerotic ulcer of the aortic arch. Additionally, she also had one vessel coronary artery disease and type B abdominal aortic dissection. She was then managed with open aortic arch repair and coronary artery bypass grafting. If required, elective endovascular repair will be done for the abdominal aorta on a later date.

Saccular Aneurysms of the Transverse Aortic Arch: Treatment Options Available in the Endovascular EraBased on a Presentation at the 2013 VEITH Symposium, November 19-23, 2013 (New York, NY, USA)

Saccular aneurysms of the aortic arch, whether single or multiple, are uncommon. The choice of repair technique is influenced by patients' comorbidities and age. Repairing saccular aneurysms with traditional open techniques can be technically demanding; therefore, endovascular technology and a variety of hybrid approaches have been developed to facilitate such repairs and, potentially, to improve clinical outcomes, especially in high-risk patients. There have been no large, randomized studies to compare the outcomes of these different treatment options in patients with single or multiple saccular aneurysms of the arch. In this review, we outline the etiology and common locations of these aneurysms, the different open, completely endovascular, and hybrid techniques used to treat them, and the treatment selection process.

Endovascular chimney technique of aortic arch pathologies: a systematic review

BACKGROUND

The aim of this review was to determine the safety and efficacy of endovascular chimney technique for aortic arch pathologies by performing a systematic and pooled analysis of the relevant literature.

METHODS

Electronic searches were performed in database Medline between 1994 and 2011 to identify studies on endovascular chimney technique for aortic arch pathology. The extracted variables and outcomes were synthesized through pooled analyses.

RESULTS

Eight articles with 51 patients who underwent endovascular chimney technique for aortic arch pathologies met the inclusion criteria. Chimney grafts were deployed in innominate (n = 11), left common carotid (n = 32), and left subclavian (n = 12) arteries. Single-stent chimney in the deployed artery was used in 37 patients, whereas double-stent chimney was utilized in 14 patients. The overall technical success rate was 90.2%. The overall perioperative mortality and morbidity were 5.9% and 13.7%, respectively. The stroke rate was 7.8%, and the fatal stroke rate accounted for 50%. The rates of primary early endoleaks and type-Ia endoleaks were 21.6% and 11.8%, respectively. The overall late mortality and morbidity were 4.4% and 15.5%, respectively. Of 5 late endoleaks, no secondary type-Ia endoleak occurred. No studies had adequate follow-up to reliably evaluate the long-time durability.

CONCLUSIONS

Endovascular chimney technique is technically feasible with the high initial technical success rate and relatively favorable rates of perioperative outcomes for aortic arch pathologies. However, further establishment of the role of endovascular chimney necessitates the accumulation of more cases and comparative study with other management as well as prolonged follow-up.

The double two-chimney technique for complete renovisceral revascularization in a suprarenal aneurysm

Suprarenal pathologies can be treated with immediately available devices with the chimney technique, which offers a bail-out in patients not eligible for a branched or fenestrated stent graft. We present an adjusted chimney technique for total renal and visceral revascularization in a patient with a suprarenal aneurysm. Although short-term results look promising, longer follow-up is anticipated.

[Treatment of thoracic aortic disease using endovascular stent-grafts: from therapeutic indications to possible complications]

Thoracic endovascular aortic repair (TEVAR) is a minimally invasive technique which is increasingly used in different thoracic aortic pathologies such as aortic aneurysm, complicated type B aortic dissection, aortic trauma, intramural hematoma and penetrating aortic ulcer. In this paper we discuss the main indications for endovascular stent-grafts in the treatment of thoracic aortic disease, based on three cases in which this procedure was used for three different conditions: degenerative aneurysm, complicated type B dissection and post-traumatic injury. These case reports add to the evidence that TEVAR is a safe and feasible therapeutic alternative in selected patients with thoracic aortic disease, improving aortic remodeling, with relatively low morbidity and mortality. The main complications and difficulties related to the procedure are also discussed.

Technique for branched thoracic stent-graft repair of a chronic type a aortic dissection in a patient with multiple prior sternotomies

PURPOSE

To present a technique for endovascular treatment of a type A aortic dissection in a patient with multiple prior sternotomies and multiple medical comorbidities.

TECHNIQUE

The method is illustrated in a 76-year-old man with a history of hypertension, hyperlipidemia, coronary artery disease, and open repair of a type A aortic dissection via a median sternotomy. The latter procedure was complicated by a pericardial effusion requiring drainage and sternal re-wiring. The diameter of the residual type A dissection beginning just distal to the aortic root had increased by 1.5 cm over 1 year, indicating the need for further intervention. To avoid redo sternotomy, a hybrid endovascular approach was planned, but it would require landing the stent in the ascending aortic arch, thus mandating branch vessel revascularization. Prior to stent-graft deployment, right-to-left carotid-carotid and left carotid-subclavian artery bypasses were performed with 8-mm polytetrafluoroethylene grafts. Three Talent grafts were deployed from the celiac artery to the left subclavian artery. A pre-wired homemade branched Talent stent-graft (34×34×115 mm) was used to revascularize the innominate artery and secure the arch. Transvenous ventricular pacing was used to improve deployment accuracy. A 10×38-mm iCast stent was placed through the branch and extended into the innominate artery. The subclavian artery was occluded with 2 Amplatzer plugs. Postoperative computed tomography demonstrated excellent proximal fixation, a widely patent branched graft to the innominate artery, and thrombosis of the aneurysmal false lumen.

CONCLUSION

Treatment of type A dissections remains a difficult surgical challenge. The approach taken should be tailored for each patient. We successfully employed a combination of available minimally invasive techniques to treat a patient who was not ideally suited to any of the individual strategies.

Endografting in the aortic arch - does the proximal landing zone influence outcome?

OBJECTIVES

To analyse early and midterm results of thoracic aortic endografting (TEVAR) in the aortic arch.

METHODS

Between January 1997 and February 2009 178 patients received TEVAR in the aortic arch at our institution. This population was subdivided into four groups according to the proximal landing zone (LZ) classification in the aortic arch by Ishimaru et al. and a retrospective analysis regarding perioperative mortality, morbidity and endoleak formation was performed.

RESULTS

The overall 30-day mortality rate was 14% with no statistical significant difference between LZ's 0-3 (p=0.274). Renal insufficiency (hazard ratio (HR) 2.5; p=0.0119), age >75 years (HR 3.1; p=0.0019) and emergency procedures (HR 8.9; p < 0.0001) were independent predictors of death. There was no significant difference regarding type I (p=0.07) or type III (p=0.49) endoleaks between the proximal LZs, but a significant difference regarding the development of type II endoleaks (p=0.01).

CONCLUSIONS

The present study showed no influence of the proximal LZ on perioperative mortality and morbidity rate. Furthermore it did not influence relevant (type I/III) endoleak formation.