Technical Strategies to Expand Stent-Graft Applicability in the Aortic Arch and Proximal Descending Thoracic Aorta

Postoperative imaging of thoracic aortic repairs

Imaging plays a crucial role in the postoperative monitoring of thoracic aortic repairs. With the development of multiple surgical techniques to repair the ascending aorta and aortic arch, it can be a daunting challenge for the radiologist to diagnose potential pathologies in this sea of various techniques, each with their own normal postoperative appearance and potential complications. In this paper, we will provide a comprehensive review of the postoperative imaging in the setting of thoracic aortic repairs, including the role of imaging, components of thoracic aortic repairs, the normal postoperative appearance, and potential complications.

Total Arch Debranching Thoracic Endovascular Aortic Repair Using Femoral Artery Inflow

Some patients with aortic arch aneurysm are ineligible for open repair because of excessive perioperative risk, and others may not be suited for total endovascular repair due to anatomic constraints. We herein report a case of aortic arch aneurysm in a 94-year-old woman. The patient underwent hybrid aortic arch repair consisting of total arch debranching using bilateral femoral artery inflow and thoracic endovascular aortic repair. The patient was discharged without complications and is in good condition with dependent ambulation at 14 months of follow-up. Although a careful selection of cases is highly recommended, the use of the femoral artery inflow for arch debranching is considered to be a viable rescue option for high-risk patients.

Early Results of a Novel Gutter-Free Chimney Stent-Graft System to Treat Aortic Arch Dissection: Single-Center Data from a Prospective Clinical Trial

AIMS

Discuss the clinical value, technique characteristics, and early follow-up results of a newly designed gutter-free chimney stent-graft system for aortic arch pathology.

METHODS AND RESULTS

About 13 patients with aortic arch dissection were enrolled in a clinical trial testing a novel gutter-free stent-graft between February 2019 and December 2020. All 13 patients were male, age 52.6±10.4 years. The implantation time was 14.0±6.9 minutes; total procedure time was 89.5±19.8 minutes. The volume of contrast was 79.6±7.2 ml. And 15 aortic stent-grafts were implanted, and all 13 patients had chimney branch stent-grafts implanted into the left subclavian artery (LSA). There were 3 (23.1%) cases of immediate type Ιa endoleak after thoracic endovascular aortic repair (TEVAR), and 7.7% type Ιa endoleaks occurred in delayed fashion. Survival at 2 years was 100%, and the 2-year patency of chimney stent-grafts was 100%.

CONCLUSIONS

This study reports early success with good freedom from endoleak using a novel stent-graft designed for chimney TEVAR to treat aortic arch dissection. Postoperative survival and patency of the branch stent-grafts were excellent. Additional data from this multicenter clinical trial will be forthcoming.

Early Efficacy of In Situ Fenestration with a Triple Chimney Technique for High-Risk Stanford Type A Aortic Dissection: A Single-Center Retrospective Study

Purpose

The objective of this investigation was to study the early efficacy of in situ fenestration with triple chimney technique for high-risk type A aortic dissection patients.

Methods

This study included 24 patients who were treated by in situ fenestration with TCT for high-risk TAAD between January 2018 and December 2019. Multiple comorbidities or preoperative critical conditions rendered patients ineligible for open surgery, but all patients that were evaluated and considered had to undergo operation. By analyzing the regular follow-up data, the early postoperative efficacy of the patients was evaluated.

Results

The average age of the 24 patients was 65.4 ± 9.3 years. The success rate of the operation was 100%, as all the patients were discharged successfully. There were no serious neurological complications or persistent endoleakage. The mean follow-up time was 21.4 ± 6.9 months. The patency rate of all branching stents was 100%, with no stent displacement, stenosis, or blockage observed. While none presented with type I endoleakage, one patient (4.2%) presented asymptomatic type II endoleakage around the left subclavian artery stent. Currently, 23 of the 24 patients remain alive.

Conclusion

Initial results are encouraging with TCT for high-risk TAAD. However, due to its high selectivity and potential complexity related to surgical risks, the mid- and long-term efficacy of this technique remains unknown. For patients who are eligible for open heart surgery, we still recommend it be performed.

Carotid-Carotid Transposition for Zone 1 Thoracic Endovascular Aortic Repair

OBJECTIVES

Carotid-carotid bypass is the standard technique for cervical aortic arch debranching to maintain left common carotid artery perfusion with zone I thoracic endovascular aortic repair (TEVAR), while left-to-right carotid-carotid transposition (CCT) has been described as an autologous alternative. We report on our center's experience with CCT in the setting of zone I TEVAR. This is the only published series of this technique.

METHODS

All patients who underwent CCT, defined by CPT code 35509, between 2017 and 2020 were identified at our tertiary care center. Patient demographics, indications for CCT, complications specific to CCT, operative details, post-operative course, and outcomes were retrospectively reviewed.

RESULTS

A total of 13 patients underwent CCT prior to zone 1 TEVAR. The indications for intervention were thoracic or thoracoabdominal aortic aneurysms and dissections secondary to hypertension (n = 10), Marfan syndrome (n = 2), and Turner syndrome with aneurysmal degeneration of previous coarctation repair (n = 1). There was a high incidence of preexisting hypertension (92%), malnutrition (69%), and smoking (61%) in this cohort. Operative intervention was performed on both an elective (n = 7, 54%) and an urgent (n = 6, 46%) basis. Complications directly related to CCT included transient unilateral recurrent laryngeal nerve deficit (n = 1, 7.7%). There were no cerebrovascular events, surgical site infections, or procedure-related mortalities. All transpositions with follow-up imaging were patent without stenosis or thrombosis (average 7.2 months, n = 10). There were no late complications related to CCT.

CONCLUSIONS

CCT is a safe and autologous alternative to carotid-carotid bypass for left common carotid artery revascularization with zone I TEVAR.

Chimney Endografting for Zone 2 Thoracic Endovascular Aortic Repair Using The Reorientation Technique

The purpose of this report was to describe the reorientation of the chimney graft technique to downsize brachial artery access during thoracic endovascular aortic repair and thus preserve left subclavian artery flow. In the case described herein, the chimney graft was advanced not from the brachial or axillary artery, but from the common femoral artery, over a brachiofemoral pull-through wire. The chimney graft was then turned out into the ascending aorta by balloon dilatation via percutaneous brachial access (“reorientation”). Despite the use of a large-diameter chimney graft, the chimney technique with percutaneous brachial access was successfully performed using the reorientation technique.

Chimney technique for aortic arch pathologies: an 11-year single-center experience

PURPOSE

To report our single-center experience with the chimney technique for aortic arch pathologies and the mid- to long-term results in these patients.

METHODS

From June 2002 to May 2013, 26 patients (18 men; mean age 71.2 years, 53-86) underwent thoracic endovascular aortic repair (TEVAR) combined with chimney technique. Indications for treatment were: a proximal landing zone <15 mm long distal to the left subclavian artery (LSA), thoracic aortic aneurysm (n=13), complicated type B aortic dissection (n=10), type I endoleak after previous TEVAR (n=2), and penetrating aortic ulcer (n=1). Treatment was performed in the emergency setting in 7 cases. The 28 chimney stent-grafts (double chimneys in 2 patients) were deployed in the innominate artery (n=7), left common carotid artery (n=10), and LSA (n=11). All patients underwent computed tomography before discharge, at 1, 6, and 12 months, and yearly thereafter.

RESULTS

Technical success was 100%. One (3.8%) perioperative death was due to a cerebral hemorrhage. No major stroke was registered, but 3 (11.5%) minor strokes occurred (all resolved). Paraparesis developed in 2 (7.7%) patients. Median follow-up was 36.8 months (range 1-131), during which an additional 4 (15.4%) patients died, but only 1 death was aneurysm-related. Chimney graft patency was 89.3% (25/28); an asymptomatic fracture was found in a patent chimney stent-graft at the 18-month follow-up. The type I endoleak rate was 23% (n=6); 3 endoleaks associated with aneurysm sac enlargement were treated.

CONCLUSION

The chimney technique for aortic arch pathologies is safe and feasible and may be an option in patients considered at high risk for surgery or who are ineligible for conventional TEVAR, especially in the emergency setting. Concern persists regarding type I endoleak, and long-term follow-up remains mandatory.

Total arch repair using supra-aortic debranching technique with banding of the ascending aorta for endovascular stent graft fixation

Endovascular stenting requires a satisfactory landing zone that guarantees fixation and sealing of the proximal part of the endograft. We report total arch repair using supra-aortic debranching technique with banding of the ascending aorta for endovascular graft fixation. An 85-year-old man presented with hoarseness of voice. A fusiform aneurysm with a maximum transverse diameter of 62 mm on the aortic arch was identified by computed tomographic angiography. Supra-aortic arch debranching of the 3 neck vessels using a trifurcated graft and coronary arterial bypass grafting were performed while closely monitoring the regional cerebral oxygen saturation. The ascending aorta was dilated to 41 mm; we successfully reduced this to a mean outer diameter of 36 mm by banding the aorta using an expanded polytetrafluoroethylene surgical membrane. The endovascular procedure was performed 17 days after surgical intervention. The patient was extubated immediately after endovascular stent placement and spent 1 day in intensive care with no signs of transient or permanent neurologic events. A postoperative computed tomographic scan did not reveal any evidence of endoleak. The banding of the ascending aorta for endovascular graft fixation could facilitate endovascular aortic arch repair and provide an alternative treatment for high-risk patients.

Hybrid endovascular repair in aortic arch pathologies: a retrospective study

The aortic arch presents specific challenges to endovascular repair. Hybrid repair is increasingly evolving as an alternative option for selected patients, and promising initial results have been reported. The aim of this study was to introduce our experiences and evaluate mid-term results of supra aortic transpositions for extended endovascular repair of aortic arch pathologies. From December 2002 to January 2008, 25 patients with thoracic aortic aneurysms and dissections involving the aortic arch were treated with hybrid endovascular treatment in our center. Of the 25 cases, 14 were atherosclerotic thoracic aortic aneurysms and 11 were thoracic aortic dissection. The hybrid repair method included total-arch transpositions (15 cases) or hemi-arch transpositions (10 cases), and endovascular procedures. All hybrid endovascular procedures were completed successfully. Three early residual type-I endoleaks and one type-II endoleak were observed. Stroke occurred in three patients (8%) during the in-hospital stage. The perioperative mortality rate was 4%; one patients died post-operatively from catheter related complications. The average follow-up period was 15 ± 5.8 months (range, 1–41 months). The overall crude survival rate at 15 months was 92% (23/25). During follow-up, new late endoleaks and stent-raft related complications were not observed. One case (4%) developed a unilateral lower limb deficit at 17 days and was readmitted to hospital. In conclusion, the results are encouraging for endovascular aortic arch repair in combination with supra-aortic transposition in high risk cases. Aortic endografting offers good mid-term results. Mid-term results of the hybrid approach in elderly patients with aortic arch pathologies are satisfying.

The Aortic Arch and Ascending Aorta: Are They Within the Endovascular Realm?

Aneurysms involving the ascending aorta and arch have been historically treated with open surgical techniques requiring cardiopulmonary bypass and, in cases involving the aortic arch, utilizing deep hypothermic circulatory arrest. The reported rates of mortality range from 0% to 16.5% for surgery addressing ascending aorta and arch pathology, and stroke rates of 2% to 18%. These statistics highlight the invasiveness of these procedures. Continued development and evolution of endovascular stent-grafts has allowed for the application of endovascular interventions in the proximal descending thoracic aorta and visceral aortic segments. Based on early experiences, attention has been focused on the ascending aorta and aortic arch, where unique challenges exist and have been addressed by both extra-anatomic bypass and novel methods incorporating branched and fenestrated devices. Device evolution, coupled with increased experience by the aortic interventionalist, has resulted in successful cases of endovascular management of every section of the aorta, including aortic valve replacement. However, these experiences have also been accompanied by significant complications. In this light, new endovascular endeavors must be considered in the context of conventional treatment options, hybrid procedures, and novel branched devices. Patient factors, such as specific anatomic issues, comorbid diseases, and functional levels must play an important role in the determination of therapeutic options. Ultimately, a clinician who understands the disease and is familiar with all treatment options (interventional, medical, and open surgical) will be best suited to provide care for the aortic patient. Finally, as with any assessment of interventional strategies, rigorous follow-up and serial imaging are essential.

Incidence of neurological complications following overstenting of the left subclavian artery

OBJECTIVE

Aortic endovascular stent-graft implantation is associated with low morbidity and mortality rates. Overstenting of the left subclavian artery may be necessary to create a satisfactory proximal 'landing zone' for the stent-graft. Few cases have been published reporting adverse neurological events after overstenting of the left subclavian artery. We thus evaluated whether this procedure is associated with a higher rate of neurological complications by focusing on the management of the supra-aortic vessels.

METHODS

Twenty patients suffering from aortic arch aneurysms (n=3), descending aortic aneurysms (n=7), acute (n=6) and chronic (n=4) type-B aortic dissections underwent stent-graft repair with complete (n=14) or partial (n=6) overstenting of the left subclavian artery. Three patients underwent overstenting of the entire aortic arch with ascending aortic-bi-carotid bypass grafting. One patient with right carotid and vertebral artery occlusion underwent initial carotid-to-subclavian bypass. All patients subsequently underwent neurological examination and Doppler ultrasound for detection of neurological and peripheral vascular complications.

RESULTS

Aortic stent-graft repair was successful in all patients without acute neurologic complications. Two patients developed late central adverse neurological events: right-sided vertebral artery occlusion with brainstem infarction (n=1) and impaired binocular vision combined with dizziness (n=1), necessitating secondary subclavian transposition in one patient. Peripheral symptoms related to occlusion of the left subclavian artery were observed in five patients as sensory and motoric deficits of the left hand and arm.

CONCLUSIONS

Overstenting of the left subclavian artery as treatment of aortic pathologies in high-risk patients is feasible but associated with the risk of neurological complications and peripheral symptoms. Side effects were mild or transient in most of our patients. Detailed preoperative exploration of vascular anatomy and pathology via Doppler ultrasound, CT- or MRI scan is mandatory to avoid adverse neurological events. Prior surgical revascularization of the left subclavian artery is essential in patients with high-grade stenoses, occlusions, or anatomic variants of the supra-aortic branches. Delayed surgical revascularization is necessary only in patients with relevant subclavian steal syndrome or severe peripheral vascular symptoms.

Mid-term results of supraaortic transpositions for extended endovascular repair of aortic arch pathologies

OBJECTIVE

To evaluate mid-term results of supraaortic transpositions for extended endovascular repair of aortic arch pathologies.

METHODS

From October 2002 to July 2006, 27 patients (mean age 72 years) with aortic arch diseases were treated (arch aneurysms n=18, type B dissections n=5, perforating ulcers n=4). Strategy for distal arch disease was autologous sequential transposition of the left carotid artery and of the left subclavian artery in 17 patients. Strategy for entire arch disease was total supraaortic rerouting using a reversed bifurcated prosthesis in 10 patients. Endovascular stent-graft placement was performed metachronously thereafter.

RESULTS

Two in-hospital deaths occurred (myocardial infarction on the day prior to discharge n=1, rupture while waiting for stent-graft placement n=1). At completion angiography, all reconstructions were fully patent. Four patients had small type Ia endoleaks, two of them resolving spontaneously. Mean follow-up is 15 months (1-43 months). Three late deaths occurred (myocardial infarction n=2, sudden unknown death n=1). One-year survival was 83% and 3-year survival was 72%, respectively. Redo stent-graft placement was performed in one patient after 25 months (type III endoleak). The remaining patients had normal CT scans with regular perfusion of the supraaortic branches without any signs of endoleaks.

CONCLUSIONS

Mid-term results of alternative treatment approaches in elderly patients with aortic arch pathologies are satisfying. Extended applications provide safe and effective treatment in patients at high risk for conventional repair.

Hybrid Technique for Total Arch Repair: Aortic Neck Reshaping for Endovascular-Graft Fixation

PURPOSE

Endovascular repairs of the aortic arch aneurysms require correct placement and an appropriate landing zone for fixation, which are not present in the majority of cases.

DESCRIPTION

We report a less invasive approach in 4 patients presenting an aortic arch aneurysm. We performed a hybrid procedure that is a combination of different techniques: a mid-sternotomy is performed, followed by transposition of the supra-aortic vessels, and neck reshaping with a proximal banding of the aortic arch. In particular, we banded the aorta to facilitate and optimize the endovascular fixation of the graft, reducing postoperative type-1 endoleaks.

EVALUATION

The four procedures were uneventful with 1-day intensive care unit recovery. The postoperative and the 1-year follow-up CT scan did not reveal any endoleaks.

CONCLUSIONS

Hybrid technique, combined with banding of proximal aortic arch and endovascular grafting are an alternative technique to the conventional open aortic repair. A polyester cloth banding of the ascending and proximal aortic arch allow the neck reshaping of the aorta optimizing the fixation of the endovascular stent graft.

A Percutaneous Technique for Preservation of Arch Branch Patency During Thoracic Endovascular Aortic Repair (TEVAR):Retrograde Catheterization and Stenting

PURPOSE

To report a percutaneous endovascular technique to deal with stent-graft encroachment and coverage (partial or total) of the origin of the left common carotid artery (CCA) or the left subclavian artery during thoracic endovascular aortic repair.

TECHNIQUE

Percutaneous retrograde puncture of the left CCA was accomplished with guidewire advancement into the ascending aorta and insertion of a 6-F sheath. Balloon angioplasty and deployment of a stent across the origin of the left CCA successfully recanalized the vessel and restored normal antegrade flow and pressure. It was reasoned that the stent would maintain vessel patency by focally displacing the endograft device, preventing partial or total coverage (and obstruction) of the arch branch origin. This technique has been used successfully in 8 patients, 6 involving the left CCA and 2 the left subclavian artery. Two of the patients were lost to follow-up after 6 and 12 months. The other 6 patients have been followed from 10 to 32 months; the stented vessels have remained patent in all.

CONCLUSION

While the "interposition" of a bare metal stent between a thoracic endograft and the aortic wall is theoretically unappealing and potentially detrimental, as the direct interaction between the devices might undermine the integrity of one or both, we have not seen such problems in this limited clinical experience.

Update on Thoracic Aortic Endovascular Grafting Using the Medtronic Talent Device

This article provides a brief update on the current status of the treatment of thoracic aortic pathology using the Medtronic Talent device. Preoperative evaluation and selection criterion along with study design are described for the recently completed Phase II VALOR Trial (Evaluation of the Medtronic AVE Talent Thoracic Stent Graft System for the Treatment of Thoracic Aneurysms). In addition, the results of several recent series for the treatment of degenerative aneurysm and more complex aortic pathology such as transection, rupture and acute and chronic dissection are reviewed.

A Double-Barrel Stent-Graft for Endovascular Repair of the Aortic Arch

PURPOSE

To extend the role of endovascular aneurysm repair in the presence of angulation and dilatation of the distal arch that compromise the proximal implantation site.

CASE REPORT

A 70-year-old man with an asymptomatic 7-cm thoracic aortic aneurysm was treated with a TAG stent-graft. However, attempts to gain secure hemostatic implantation of the endograft resulted in inadvertent coverage of the subclavian and left carotid arteries. Flow to the left carotid artery was re-established by transcarotid insertion of a self-expanding covered stent alongside the primary stent-graft.

CONCLUSION

This technique may have a role as an intended part of endovascular repair when there is no suitable implantation site in the descending thoracic aorta.

Endovascular Stent Graft Treatment of a Traumatic Aortocaval Fistula

Aortocaval fistula (ACF) is an infrequently reported sequela of trauma. Most ACF have been repaired via an open approach. During the past 10 years, there has been one reported case of spontaneous ACF and two cases of traumatic ACF repaired using an endovascular technique. We present a third case of traumatic ACF repaired with an endovascular stent graft. A 40-year-old male sustained two gunshot wounds to the right chest and one to the right upper abdomen. He was taken from the emergency department directly to the operating room, where an exploratory laparotomy was performed. Through-and-through injuries to the stomach and transverse colon were repaired primarily. Subsequently, the patient developed abdominal compartment syndrome. An urgent exploratory laparotomy was performed, revealing a nonbleeding hematoma on the posterior lateral surface of the right lobe of the liver, which was left undisturbed. Open abdominal management was instituted with vacuum pack closure. On the nineteenth hospital day, the patient again had a significant decrease in hematocrit. An aortogram was performed in order to evaluate the patient for intrahepatic arterial bleeding amenable to transcatheter embolization. There was no evidence of hepatic arterial bleeding. However, a supraceliac ACF was identified. The patient was taken to the operating room, and an AneuRx aortic extension cuff was advanced under fluoroscopy and deployed to cover the fistula. Completion angiography revealed total obliteration of the ACF and appropriate placement of the stent graft. Postoperatively, the patient was returned to the intensive care unit, where his hospital course was complicated by ventilator-associated pneumonia and sepsis. Repeat computed tomographic scanning 6 months and 1 year following this repair demonstrated patency of the graft without evidence of graft migration or aortocaval communication. Further research and experience are necessary with this technique regarding long-term outcome and technical aspects. In particular, the sizing problems associated with repair of acute traumatic ACF in emergency situations should be addressed. The endovascular approach provides an attractive and exciting alternative to traditional methods for repair of ACF.

Branched Stent-Grafts for Endovascular Repair of Aortic and Iliac Aneurysms

Endovascular technique, which gains access through indirect transarterial routes and isolates the aneurysm without interrupting flow, has particular advantages in aneurysms of the aortic arch and thoracoabdominal aorta. Yet progress has been slow. The necessary branched stent-grafts face several unique technical challenges. The simplest, most versatile approach involves assembling a modular stent-graft in situ from multiple parts. Techniques vary according to the presence or absence of an overlap zone, or cuff. The first cases of this type, reported over 4 years ago, had axially oriented cuffs. Recent efforts have seen the intercomponent attachment site reduced to a ring of Nitinol around a simple fenestration, with various hybrids of cuffed and fenestrated technique in between. Other advances, such as better sheaths, better covered stents, and commercial manufacture (Cook, Australia), have helped to extend the use of branched stent-grafts to a wider range of users and a wider range of aneurysms. Although their future role remains unclear, all these devices have gone beyond the proof of concept stage, and some, such as the bifurcated component for the endovascular iliac reconstruction, are ready to become standard parts of the endovascular.

Suprarenal stents and other advances in endovascular aneurysm repair

The history of endovascular aneurysm repair has already passed through its phases of "endoexuberance" and "endoscepticism" and there is now a balanced and broad understanding of the technology,its limits and advantages. Current endovascular technique and stent-graft design is the refinement of the accumulated endovascular experience til now. It is important to make note of these technological features incorporated in current stent-grafts and the clinical experience that precipitated their introduction as the technology progresses and new applications are proposed.

Initial Results After Combined Repair of Aortic Arch Aneurysms by Sequential Transposition of the Supra-Aortic Branches and Consecutive Endovascular Stent-Graft Placement

BACKGROUND

To evaluate safety and efficacy of a combined repair of aortic arch aneurysms by sequential transposition of the supra-aortic branches and endovascular stent-graft placement.

METHODS

Between October 2002 and September 2003, 5 patients (mean age, 79.5 years) presented with aortic arch aneurysms involving the origin of the left carotid artery. Treatment was made by sequential transposition of the left carotid artery into the brachiocephalic trunk and transposition of the left subclavian artery into the already transposed left common carotid artery with consecutive endovascular stent-graft placement into the aortic arch.

RESULTS

All patients survived both procedures. At completion angiography, a small type 1a endoleak was observed in 1 patient. After 1 week, the patient was readmitted for completion three-dimensional computed tomographic scan. The leak had already occluded spontaneously. Mean follow-up was 10 months (range, 4 to 16 months). At follow-up, all patients had normal computed tomographic scans with regular perfusion of the supra-aortic branches without any signs of endoleaks.

CONCLUSIONS

Combined repair of aortic arch aneurysms by sequential transposition of the supra-aortic branches with consecutive endovascular stent-graft placement is feasible. Extended application of this technique will enable safe and effective treatment of a highly selected subgroup of patients with aortic aneurysms by avoiding conventional arch aneurysm repair in deep hypothermia and circulatory arrest.

Current status of thoracic aortic endograft repair

The advent and success of endovascular repair of abdominal aneurysms had led to the development of catheter-based techniques to treat thoracic aortic pathology. Such diseases, including thoracic aortic aneurysms, acute and chronic type B dissections,penetrating aortic ulcers, and traumatic aortic transection, challenge surgeons to perform complex operative repairs in high-risk patients. The minimally invasive nature of thoracic endografting may provide an attractive alternative therapy especially in patients deemed unfit for thoracotomy. A worldwide review of thoracic endografting demonstrates encouraging short- and midterm outcomes with significant reductions in morbidity and early mortality.Long-term surveillance will be crucial to discover complications unique to thoracic endovascular interventions and to determine which patients are appropriate candidates for stent-graft therapy.