Experiences of Intentional Carotid Stenting in Endovascular Repair of Aortic Arch Aneurysms—Two Case Reports

Expert opinion: How to treat type IA endoleakage

Type Ia endoleaks due to failed sealing or loss of landing zone and the adequate management thereof remain crucial for long-term therapeutic success following TEVAR. This expert opinion summarizes our institutional experience with endovascular, open surgical, and hybrid techniques in the context of recent scientific publications. The rapid turnover of technical innovations, but most importantly outcome data demonstrate the requirement for increasingly patient-tailored treatment strategies and the need for specialized aortic centers. The latter should offer a complete range of treatment options, an adequate perioperative management, and the highest level of multidisciplinary expertise.

[Ascending Aorta and Aortic Arch - Endovascular Therapy Today and in the Future]

Pathologies in the region of the aortic arch may occur in isolation, but adjacent segments of the thoracic aorta - the ascending or descending aorta - are much more commonly affected. The first surgical procedures to treat the aortic arch were performed nearly six decades ago. Despite numerous improvements and innovations in the 20th and early 21st centuries, these procedures are still associated with relevant operative mortality and neurological complication rates. Endovascular techniques and modern hybrid procedures are increasingly expanding the therapeutic spectrum in the aortic arch, although the open surgical approach is currently still the gold standard. Endovascular treatment of aortic aneurysm was first performed in the early 1990s in the infrarenal abdominal aorta. It was not long before the first attempts at endovascular therapy were made for the treatment of the aortic arch. In 1996, Inoue et al. reported the use of the first commonly used endoprosthesis to treat aneurysms in the aortic arch. Continuous improvements and refinements in implantation techniques and also implanted material have resulted in endovascular therapy now being an increasingly important option compared to open surgical procedures in the descending thoracic and abdominal aorta and has partially replaced them as the gold standard. This review article aims to provide an overview of the prerequisites, results, but also limitations of endovascular surgery of the aortic arch.

Hybrid Surgery to Manage Aortic Arch Pathology

Background and Objectives: Aortic arch disease is still a high-risk surgical challenge despite major advances both in surgical and anesthesiological management. A combined surgical and endovascular approach has been proposed for aortic arch disease treatment to avoid hypothermia and circulatory arrest in high-risk patients. Materials and Methods: Between June 2004 and June 2021, 112 patients were referred to our department for aortic arch surgery; 38 (33.9%) patients underwent supra-aortic debranching and endovascular treatment. Of these, 21 (55%) patients underwent type I aortic arch hybrid debranching procedure and in 17 (45%) patients a type II aortic arch hybrid debranching procedure was performed. None of the patients were emergent. Results: No intra-operative deaths were recorded. In the type I aortic arch hybrid debranching patients’ group, one patient died at home waiting the endovascular step, one developed ascending aortic dissection and another one developed a pseudoaneurysm at the site of the debranching at follow-up. In the type II aortic arch hybrid debranching patients’ group, left carotid artery branch closure was detected at follow-up in one patient. Thirty day/in-hospital rates of adverse neurological events for both the surgical and endovascular procedures were 3% for minor stroke, with no permanent neurological deficit and 0% for permanent paraplegia/paraparesis. In 100% of the cases, the endovascular step succeeded and the type Ia endoleak rate was 0%. Conclusions: Hybrid arch surgery is a valuable option for aortic arch aneurysm treatment in patients with high surgical risk. The choice of aortic arch debranching between type I or type II is crucial and depends on anatomic and clinical patient characteristics. Further larger scale studies are needed to better define the advantages of these techniques.

Application of triple-chimney technique using C-TAG and Viabahn or Excluder iliac extension in TEVAR treatment of aortic arch dilation diseases

Background

To report the experience of a single centre regarding the application of the triple-chimney technique using C-TAG with Viabahn or Excluder iliac extension devices for the endovascular management of aortic arch dilation diseases.

Methods

From July 2016 to August 2017, 7 patients (5 men; mean age 56.1±10.8 years) with aortic arch dilation diseases were treated with the triple-chimney technique. All patients were followed up at 1, 3, and 6 months and every 6 months thereafter.

Results

Six innominate arteries were deployed with Excluder iliac extensions and one with a Viabahn cover-stent. All the left common carotid arteries and left subclavian arteries were placed with Viabahn. Reverse chimney technique was applied in four patients. Three (42.0%) type I endoleaks were found on the final angiogram. Two were apparently reduced, and one disappeared after balloon dilation. The mean follow-up time was 15.7 months (9-20 months). All the type I endoleak was found disappeared within 3 months. One patient died of myocardial infarction at 6 months after discharge. No other complications such as stent-graft migration, occlusion, type II endoleak or neurological stroke occurred.

Conclusions

The use of C-TAG coupled with Viabahn or Excluder iliac extension is feasible and effective for the treatment of aortic arch dilatation diseases. However, more patients and longer follow-up time are required to verify its long-term safety and efficacy.

Hybrid operation versus the chimney technique for reconstruction of a single aortic arch branch: a single-centre experience

OBJECTIVES

Both hybrid and chimney techniques are used for reconstruction of supra-arch branches during thoracic endovascular aorta repair (TEVAR). Our objective was to summarize our experience with reconstruction of the left common carotid artery (LCCA) or left subclavian artery (LSA) and evaluate the indications for these 2 strategies.

METHODS

The records of patients treated with hybrid or chimney TEVAR when 1 aortic branch (LSA/LCCA) needed to be covered were reviewed retrospectively. The angulations of the LSA and the LCCA were measured for analysis.

RESULTS

The average ages of the patients in the hybrid (n = 26) and chimney groups (n = 31) were 52.6 (SD 12.7) and 55.4 (SD 11.3) years, respectively. The immediate type I endoleak rate was significantly higher in the chimney group (58.1% vs 15.4%, P = 0.001). No in-hospital deaths occurred in either group, and the follow-up mortality rate was 11.5% in the hybrid group and 3.2% in the chimney (P = 0.32) group, whereas the aortic-related mortality rates were 3.8% and 0%, respectively (P = 0.46). The rates of type I endoleaks were significantly higher if the angles of the LSA/LCCA were larger than 38.3°/37.9° [LSA: >38.3°, 100% (10 of 10) vs < 38.3°, 10% (1 of 10), P < 0.001; LCCA: >37.9°, 100% (6 of 6) vs < 37.9°, 20% (1 of 5), P = 0.015].

CONCLUSIONS

Branch angulation and oversizing are crucial factors for type I endoleaks and should be taken into account when choosing the surgical procedure. Our results indicated that the chimney TEVAR is more suitable in cases with small target branch angulation. Additional oversizing may help to prevent post-TEVAR endoleaks.

Chimney Technique in Supra-Aortic Branch Reconstruction in China: A Systematic and Critical Review of Chinese Published Experience

BACKGROUND

The chimney graft (CG) technique has been proposed as a complete endovascular supra-aortic branch reconstruction for aortic pathologies. Due to the rapid growth of thoracic endovascular aortic repair (TEVAR) in China, we aimed to investigate the current data of the CG technique in this most populous country.

METHODS

Studies of supra-aortic branch reconstruction using the CG technique from Chinese centers were collected and analyzed.

RESULTS

A total of 294 patients from Chinese centers who underwent TEVAR with CGs were included. There were 301 CGs performed, with a technical successful rate of 97.7%. The rate of early type I endoleaks was 7.1%, and the patency rate of the CGs was desirable. Balloon-expandable bare CGs were significantly associated with good early outcomes and a low rate of endoleaks.

CONCLUSION

Current data from China revealed positive outcomes using CGs for supra-aortic branch reconstruction. Balloon-expandable bare CGs may be the first choice according to the data available but should be considered with caution.

Aortic aneurysm endovascular treatment with the parallel graft technique from the aortic arch to the iliac axis

BACKGROUND

The chimney technique has been developed for the treatment of complex aortic aneurysms. We analyzed the midterm to long-term outcomes of this approach from a single-center experience.

METHODS

From October 2008 to July 2016, 58 patients underwent endovascular aortic aneurysm repair using the chimney technique. Indications for treatment were thoracic aortic aneurysm (TAA) (N.=11), thoracoabdominal aortic aneurysm (TAAA) (N.=2), pararenal aortic aneurysm (PAAA) (N.=15), aortoiliac/isolated hypogastric artery aneurysm (N.=25), type I endoleak after previous TEVAR/EVAR (N.=4), proximal pseudoaneurysm after AAA open repair (N.=1). Elective (82.8%) and emergent (17.2%) procedures were included.

RESULTS

The immediate technical success was 100%. Single, double and triple chimneys were performed in 46, 10, and two patients, respectively. Overall, 61 target vessels (three left common carotid arteries, eight left subclavian arteries, three celiac trunks, three superior mesenteric arteries, 19 renal arteries and 25 hypogastric arteries) were involved. Postoperative mortality was 0. No neurologic complications were registered. Primary patency rate of the chimney stent/stent graft was 98.3%. Low-flow type I endoleak was observed in four patients (6.9%). Postoperative chimney graft re-intervention rate was 1.7%. The median follow-up was 32±20 months (range 3-96 months). Overall estimated survival at 12, 50, and 80 months was 100%, 89% and 44%, respectively. Estimated freedom from endoleak at 1, 12, 24, and 36 months was 96.5%, 95%, 95%, and 93%, respectively. One hypogastric artery stent-graft occluded at the 3rd month of follow-up. No reintervention was performed.

CONCLUSIONS

Our experience with the chimney technique for aortic aneurysms from the aortic arch to the iliac axis shows promising and durable mid- and long-term results. Endograft oversizing, associated with the chimney graft diameter and length choice remain fundamental to reduce the risk of the most frequent procedure complications: type I endoleak and CG occlusion. The wider use of this technique should be justified in patients considered at high risk for open repair and/or not suitable for the custom-made branched/fenestrated endografts.

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.

The chimney-graft technique for preserving supra-aortic branches: a review

Evolution in the endovascular era has influenced the management of aortic arch pathologies. "Chimney" or "snorkel" graft technique has been used as an alternative in high risk patients unfit for open repair. We reviewed the published literature on the chimney graft technique for preservation of the supra-aortic branches in order to provide an extensive insight of its feasibility and efficacy and investigate its outcomes. 18 reports were identified, with a total of 124 patients and 136 chimney. Primary technical success was achieved in 123/124 patients (99.2%). The perioperative mortality rate was 4.8% and the stroke rate was 4%, while events of spinal cord ischemia were rare. The overall endoleak rate was 18.5%; 13 patients (10.5%) developed a type I endoleak and 10 (8%) patients a type II endoleak. During a median follow-up period of 11.4 months (range, 0.87-20.1 months) all implanted chimney grafts remained patent. From this, we conclude that endovascular aortic arch repair with chimney grafts is associated with a lower mortality rate compared to totally open or hybrid reconstruction. However, the stroke rate remains noteworthy, and requires longterm data to elucidate.

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.

Triple-barrel graft as a novel strategy to preserve supra-aortic branches in arch-TEVAR procedures: clinical study and systematic review

OBJECTIVE

To report our early experience with total endovascular repair of aortic-arch aneurysm using double chimney-grafts and present a literature overview.

PATIENTS AND METHODS

The double chimney-graft technique was performed in six male patients with contained ruptured aneurysm, dissecting aneurysm, pseudoaneurysm, penetrating aortic ulcer and proximal endoleak after TEVAR. Furthermore, a systematic electronic health database search of available articles was conducted according to PRISMA Guidelines.

RESULTS

In all cases, all supra-aortic vessels had to be covered with aortic stent-graft to receive a sufficient landing and sealing zone. Chimney-grafts were introduced to the ascending aorta slightly deeper than the thoracic stent-grafts through the cut-down exposure of the common carotid arteries. We deployed aortic stent-grafts and self-expandable chimney-grafts simultaneously and successfully. The patient with contained ruptured aneurysm died due to cardiopulmonary failure on day 19, the others survived. We detected two 'gutter' endoleaks. As a result of literature search, 12 articles met the inclusion criteria. Two articles described the double-chimney technique.

CONCLUSIONS

The use of double chimney-grafts is possible in high-risk patients where the proximal landing zone of endograft would be in zone 0. The available data is still limited. The long-term follow-up remains to be evaluated with the increased number of patients treated.

Chimney technique in the endovascular management of complex aortic disease

The objective of this study was to systematically review the literature reporting on the chimney technique and perform an analysis of the outcomes. A search of electronic databases was undertaken to identify all studies reporting on the outcome of the chimney technique. The selected articles were divided into those reporting on the treatment of aortic pathology involving the visceral and those involving the supra-aortic branches. Twenty-one articles reporting on the treatment of juxta/supra-renal aorta and aortic arch disease in 102 and 37 patients, respectively, were identified. In the visceral group, an overall technical success rate of 91% was achieved, the perioperative major morbidity and mortality rates were 17 and 5%, respectively, and an early type I endoleak developed in 13 patients (13%). During follow-up, one patient died of intestinal ischemia. In the supra-aortic group, the technical success rate was recorded in 95%, and three patients (8%) developed an early type I endoleak. Three patients (13%) required conversion to open surgery during follow-up. In conclusion, this technique may be viewed as a complementary technique in high-surgical-risk patients.

The modified chimney technique with a thoracic aortic stent graft to preserve the blood flow of the left common carotid artery for treating descending thoracic aortic aneurysm and dissection

While thoracic endovascular aortic repair is an effective treatment option for descending thoracic aorta pathology, it does have limitations. The main limitation is related to the anatomical difficulties when disease involves the aortic arch. A fenestrated, branched aortic stent graft and hybrid operation has been introduced to overcome this limitation, but it is a custom-made device and is time consuming to manufacture. Furthermore, these devices cannot be used in an emergency setting. We report two patients with massive descending thoracic aortic aneurysm and ruptured aortic dissection very near the aortic arch who underwent a procedure which we named the modified chimney technique. The modified chimney technique can be used as a treatment option in such an emergency situation or as a rescue procedure when aortic pathology is involved near the supra-aortic vessels.

Preservation of aortic arch branches using chimney and sandwich stent grafts

PURPOSE

To share our hybrid endovascular experiences using chimney or sandwich stent grafts for acute aortic arch pathologies.

METHODS

Hybrid procedures for a distal aortic arch aneurysm and an ascending anastomotic aortic aneurysm rupture were reported. Right to left common carotid and left axillar artery bypasses were located. Covered stents were inserted into the inominate artery, with the flow-proximal end located in the ascending (standard chimney) or the descending aortic stent graft (retrograde sandwich).

RESULTS

Both cases had no signs of brain ischemia. Aneurysms are decreasing in size.

CONCLUSION

Chimney and sandwich techniques were technically feasible in the complex and acute situations.

Early results of left carotid chimney technique in endovascular repair of acute non-a-non-B aortic dissections

PURPOSE

To report our early experience with endovascular repair of acute non-A-non-B aortic dissections using chimney grafts to preserve blood flow to a left common carotid artery (LCCA) located in the proximal landing zone.

METHODS

From June 2009 to May 2010, 8 patients (7 men; mean age 49 years, range 29-75) with acute non-A-non-B aortic dissection and no adequate proximal sealing zones underwent thoracic endovascular aortic repair (TEVAR). Covered stents were placed parallel to the aortic stent-grafts to restore flow to the LCCAs while extending the proximal fixation zones; the left subclavian arteries were intentionally covered after carefully cerebrovascular assessment. Follow-up examinations included computed tomography (CT) at 2 weeks, 3 months, 6 months, 12 months, and yearly thereafter.

RESULTS

All the procedures were completed successfully, with one main aortic stent-graft deployed and one chimney graft implanted in the LCCA. Two retrograde type II endoleaks identified intraoperatively were left untreated but followed closely using CT. There were no instances of puncture site complications, stroke, paralysis, or death during the hospital stay. The 30-day mortality was 0%. During the mean 11.4-month follow-up (range 6-15), there was no mortality, and duplex ultrasound and CT showed patency of all stent-grafts, enlargement of the true lumen, and compression of the false lumen. One type II endoleak disappeared in 2 weeks postoperatively, while the other gradually faded until it was nearly gone at 11 months postoperatively. During follow-up, no renal insufficiency, new late endoleaks, endograft migration, fracture, stent-graft related complications, or deaths were observed.

CONCLUSION

In short-term follow-up, TEVAR combined with the chimney technique seems promising for aortic dissections that involve the aortic arch with inadequate proximal sealing zones. More cases and long-term results are needed to evaluate the safety and efficiency of this alternative endovascular technique.

"The chimney graft"-a simple technique for endovascular repair of complex juxtarenal abdominal aortic aneurysms in no-option patients

Endovascular aneurysm repair (EVAR) has developed as a less invasive alternative to open surgery for patients with abdominal aortic aneurysms. However, patients with very short infrarenal necks require complex surgical open repair, which is associated with increased mortality and morbidity. The risk of complex open repair may be prohibitive in high-risk patients. Thus, modifying the technique of EVAR may be required in such patients to successfully exclude aneurysms. An alternative that can be used in these patients is the so-called "chimney graft" technique. We report two cases where the chimney graft technique was used with good immediate results.

Coverage of the left subclavian artery during thoracic endovascular aortic repair

BACKGROUND

Thoracic aortic stent grafts require proximal and distal landing zones of adequate length to effectively exclude thoracic aortic lesions. The origins of the left subclavian artery and other aortic arch branch vessels often impose limitations on the proximal landing zone, thereby disallowing endovascular repair of more proximal thoracic lesions.

METHODS

Between October 2000 and November 2005, 112 patients received stent grafts to treat lesions involving the thoracic aorta. The proximal aspect of the stent graft partially or totally occluded the origin of at least one great vessel in 28 patients (25%). The proximal attachment site was in zone 0 in one patient (3.6%), zone 1 in three patients (10.7%), and zone 2 in 24 patients (85.7%). Patients with proximal implantation in zones 0 or 1 underwent debranching procedures of the supra-aortic vessels before stent graft repair. In one patient who underwent zone 1 deployment, the left subclavian artery was revascularized before stent graft deployment. Among patients who underwent zone 2 deployment with partial or complete occlusion of the left subclavian artery, none underwent prior revascularization. Patients were assessed postoperatively and at follow-up for development of neurologic symptoms as well as symptoms of left upper extremity claudication or ischemia.

RESULTS

Mean follow-up was 7.3 months. Among the 24 patients with zone 2 implantation, 10 (42%) had partial left subclavian artery coverage at the time of their primary procedure. A total of 19 patients experienced complete cessation of antegrade flow through the origin of the left subclavian artery without revascularization at the time of the initial endograft repair as a result of a secondary procedure or as a consequence of left subclavian artery thrombosis. Left upper extremity symptoms developed in three (15.8%) patients that did not warrant intervention, and rest pain developed in one (5.3%), which was treated with the deployment of a left subclavian artery stent. Two primary (type IA and type III) endoleaks (7.1%) and one secondary endoleak (type IA) (3.6%) were observed in patients who underwent zone 2 deployment. Three cerebrovascular accidents were observed. Thoracic aortic lesions were successfully excluded in all patients who underwent supra-aortic debranching procedures.

CONCLUSION

Intentional coverage of the origin of the left subclavian artery to obtain an adequate proximal landing zone during endovascular repair of thoracic aortic lesions is well tolerated and may be managed expectantly, with some exceptions.