Treatment of Aortic Arch Aneurysms with a Modular Transfemoral Multibranched Stent Graft: Initial Experience

Early Outcomes on Triple-Branch Arch Device With Retrograde Left Common Carotid Branch: A Case Series

INTRODUCTION

Endovascular aortic arch repair using multibranch devices has been applied in patients considered at high risk for open repair. The aim of this case series was to report the early outcomes in patients managed with a new design 3 branch arch custom-made device, including a retrograde left common carotid artery (LCCA) branch.

METHODS

The Preferred Reporting Of CaSe Series in Surgery (PROCESS) guidelines were followed. All consecutive patients undergoing endovascular repair of an aortic arch lesion with a custom-made triple-branch device, including a retrograde LCCA branch (Cook Medical, Bloomington, IN, USA), between October 27, 2022, and February 28, 2023, were included. The presence of an arch aneurysm (degenerative or post-dissection) with diameter ≥55 mm and high risk for a conventional open repair set the indication for treatment. The primary outcomes were technical success and mortality at 30 days. Early morbidity and reinterventions were considered as secondary outcomes.

RESULTS

Eight elective patients (87.5% men, mean age 72.3±27.0 years) were included. Five of them (62.5%) had undergone a previous ascending aorta repair of an acute type A aortic dissection. All patients were asymptomatic, except one, with left recurrent laryngeal nerve compression. The mean maximum aortic diameter was 70.4±21.0 mm. Percutaneous femoral and axillary access was used in all cases except three in which a cut down for right carotid access was performed. Technical success was 100%. Femoral access to the LCCA and implantation of the bridging stent was performed without technical challenges. No death nor cerebrovascular event was recorded during the 30 day follow-up. Five patients (62.5%) presented major complications, 3 related to access needing reintervention and the remaining related to congestive heart failure (CHF), which were managed successfully with medical treatment. Follow-up (range 1-4 month) was uneventful, except for one patient who presented a secondary type Ia endoleak.

CONCLUSIONS

According to our early experience, the presence of a retrograde branch facilitated the revascularization of the LCCA through femoral access, decreasing the risk of cerebrovascular morbidity. Further analyses with longer follow-up are needed to evaluate the safety and efficacy of the device.

CLINICAL IMPACT

Data arising mainly from the retrograde branch for the revascularization of the LSA are encouraging from a variety of devices. The premiminary experience with a triple-branched arch device, with a retrograde branche for the LSA but also for the LCCA, was associated with no 30 day mortality and 100% technical success.The device's design allowed swift catheterization and completion of the LCCA revascularization using femoral access exclusively.

Status of diagnosis and therapy of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) are characterized by localized dilation of the abdominal aorta. They are associated with several serious consequences, including compression of adjacent abdominal organs, pain, treatment-related financial expenditure. The main complication of AAA is aortic rupture, which is responsible for about 200,000 deaths per year worldwide. An increasing number of researchers are dedicating their efforts to study AAA, resulting in significant progress in this field. Despite the commendable progress made thus far, there remains a lack of established methods to effectively decelerate the dilation of aneurysms. Therefore, further studies are imperative to expand our understanding and enhance our knowledge concerning AAAs. Although numerous factors are known to be associated with the occurrence and progression of AAA, the exact pathway of development remains unclear. While asymptomatic at most times, AAA features a highly unpredictable disease course, which could culminate in the highly deadly rupture of the aneurysmal aorta. Current guidelines recommend watchful waiting and lifestyle adjustment for smaller, slow-growing aneurysms, while elective/prophylactic surgical repairs including open repair and endovascular aneurysm repair are recommended for larger aneurysms that have grown beyond certain thresholds (55 mm for males and 50 mm for females). The latter is a minimally invasive procedure and is widely believed to be suited for patients with a poor general condition. However, several concerns have recently been raised regarding the postoperative complications and possible loss of associated survival benefits on it. In this review, we aimed to highlight the current status of diagnosis and treatment of AAA by an in-depth analysis of the findings from literatures.

Endovascular Options for the Ascending Aorta and Aortic Arch - A Scoping Review

The gold standard for aneurysmal repair of the ascending aorta and the aortic arch has been open surgery with an established track record of good results in suitable patients. In recent years, with innovations in the endovascular field alternative endovascular solutions for pathologies of the aortic arch and ascending aorta became available. At first reserved only for highly selected patients unfit for open surgery, endovascular aortic arch repair is now being offered to patients with suitable anatomy in high volume referral centers after discussion in an interdisciplinary team. The present scoping review aims at providing an overview on indications, available devices, technical aspects and feasibility studies of endovascular arch repair both in elective and emergent situations, including also experiences and considerations from our center.

A review: Single and multi-branch devices for the treatment of aortic arch pathologies with proximal sealing in Ishimaru Zone 0

Recently published experience has shown that endovascular management of the aortic arch, including sealing in the proximal zones, can be a viable option for patients considered unfit for conventional open repair. Endograft designs vary and include single or multibranch devices, with or without the addition of surgical debranching. Initial reports show that both techniques can be performed with high technical success and acceptable perioperative morbidity and mortality rates in high volume centers. Single branch devices, available off-the-shelf, may provide a treatment option for emergent presentations where patients cannot wait for the design and manufacture of a customized endograft. Double or triple branched endografts are now increasingly implanted in high-volume aortic centers. The purpose of this review is to describe the single and multibranched endovascular devices currently available for aortic arch repair, their associated published outcomes, and to discuss their relative advantages and disadvantages.

Hemodynamic numerical simulation of aortic arch modular inner branched stent-graft in eight early patients from the first-in-human case series

Background

The modular inner branched stent-graft (MIBSG) (WeFlow-Arch™) is an emerging device for challenging aortic arch pathologies. Hemodynamic numerical simulation is conducive to predicting long-term outcomes as well as optimizing the stent-graft design.

Objective

This study aims to analyze the hemodynamic characteristics of the MIBSG devices based on numerical simulation analyses.

Methods

From June 2019 to June 2021, MIBSGs were utilized in eight cases. Numerical simulation analyses of branch perfusion and indicators including the time-averaged wall shear stress, oscillatory shear index, and relative residence time were performed.

Results

Lesions involved Zone 1 (n = 2), Zone 2 (n = 4), and Zone 3 (n = 2). Branched stent-grafts were deployed in the innominate artery and left common carotid artery (n = 5) or in the innominate artery and left subclavian artery (n = 3). The hemodynamic change in common was increased perfusion in the descending aorta and left common carotid artery. Half of the patients had increased cerebral perfusion of 8.7% at most, and the other half of the patients showed a reduction of 5.3% or less. Case 3 was considered to have acquired the greatest improvement in hemodynamic features.

Conclusion

The MIBSG showed improved hemodynamic features in most cases. The design of the MIBSG could be partly modified to acquire better hemodynamic performance.

Theoretical Feasibility of Using Arch Branched Endograft Devices for Repair of Post Type A Aortic Dissection in Patients With Prior Ascending Aortic Replacement

PURPOSE

Ascending aortic replacement is a common emergency procedure for treating acute type A aortic dissection. Secondary open or endovascular interventions for residual arch pathologies is difficult because of adhesions, short prosthetic grafts, and distorted anatomies. Aortic arch branched stent grafts have emerged as a potential solution for these patients if they have suitable anatomical conditions. This study aimed to evaluate the theoretical anatomical and technical feasibility of 2 currently used aortic arch branch endografts in patients who had prior replacement of the ascending aorta.

MATERIALS AND METHODS

All patients who had a prosthetic ascending aortic or hemiarch replacement for acute type A dissection in a single institution between January 2013 and December 2018 were included. Contrast computed tomography images on the most recent follow-up were analyzed on a 3-dimensional workstation. Morphological parameters were measured individually for the ascending aorta, aortic arch, supra-aortic branches, and access iliac arteries. The computed tomography scan of each patient was individually evaluated for anatomical suitability for the arch branched and double-branch devices according to set selection criteria.

RESULTS

Computed tomography images of 56 patients (median age of 57 years, 45 males) were reviewed. Based on our evaluation, 26 patients (46.4%) were good candidates for an endovascular arch branched device. It would be feasible for 13 patients (23.2%), but prudent preoperative planning was required due to complicated anatomy. The other 17 patients (30.4%) were unsuitable because they met at least 1 exclusion criterion. Short prosthetic grafts, extreme graft angulations, and extensive dissections in the supra-aortic branches were the main reasons for exclusion.

CONCLUSION

Endovascular repair using arch branched endografts is feasible in patients with prior ascending aortic arch or hemiarch replacement for acute type A aortic dissection. The most common anatomical conditions that may influence the feasibility of the arch branched endograft procedure include insufficient proximal seal length, severe angulation of the graft, and extensive aortic dissection within the supra-aortic vessels.

Mortality and Major Adverse Events Improve With Increased Institutional Experience for Fenestrated and Branched Endovascular Aortic Repair

OBJECTIVE

Our objective was to evaluate temporal trends in outcomes at our institution in the context a more heterogenous application of fenestrated/branched endovascular aneurysm repair (F/BEVAR).

METHODS

Patient and aneurysm characteristics, procedure details, and postoperative outcomes were collected for consecutive patients undergoing F/BEVAR between 2002 and February 2019 at our institution. Outcomes were compared between tertile 1 (T1, 2002-2010, n=47), T2 (2011-2014, n=47), and T3 (2015-February 2019, n=47).

RESULTS

We included 141 patients (74.8 ± 8.1 years, 83% male) with a mean follow-up of 28.0 ± 31.6 months. Proportion of patients with hypertension (63.8% T1, 85.1% T3, p=0.009), diabetes (6.4% T1, 29.7% T3, p=0.005), chronic obstructive pulmonary disease (COPD; 27.6% T1, 42.5% T3, p=0.07), and history of stroke (4.2% T1, 17% T3, p=0.07) increased over time. Aneurysm diameter (65.3±11.4mm) and extent (56.0% juxtarenal/pararenal, 22.0% type IV, 22.0% type I-III) did not differ between groups. Custom made devices were implanted in 96.5% of cases with 3.4 ± 0.7 vessels reimplanted/case. There was a trend toward increased history of aortic surgery (p=0.008) and less custom made devices (p=0.007) in T3.Total procedure time (383.5±119.2 minutes T1, 316.2±88.4 T3, p=0.02), contrast volume (222.8±109.1 mL T1, 139.2±62.7ml T3, p<0.0001), and estimated blood loss (601.3±458.1 mL T1, 413.3±317.7 mL T3, p=0.02) decreased over time. Overall 30-day mortality was 6.3%, 10.6%-T1, 6.3%-T2, and 2.1%-T3 (p=0.09). We noted significant improvement in survival over time; 1- and 3-year survival was 79% and 56%, 89% and 83%, and 90% and 90%, for T1, T2, and T3, respectively (p=0.007). In all, 467 of 480 target vessels were revascularized (97.3% success). Reintervention rate (30-day: 13.5%, follow-up: 34.7%) and reintervention free survival was not significantly different between groups. Any major adverse event (MAE) occurred in 36.9% of patients overall with a significant decrease from early (51.1%), mid (34.9%), to late in our experience (25.5%, p=0.03). In multivariate analyses, increasing institutional experience (T3), procedure time, age, and sex were independent predictors of major adverse events.

CONCLUSION

We have shown improvement in F/BEVAR outcomes including mortality, MAEs, and procedural metrics with increasing institutional experience. We postulate that a combination of advancements in technique, surgical team and postoperative care experience, graft design and stent technologies, and patient selection contributed to improvement in outcomes.

Aortic arch stenting: current strategies, new technologies and future directions

Operating on the aortic arch is a formidable challenge. Open operations remain the gold standard, but despite improvement in technique and outcomes, they are still associated with significant morbidity and mortality. The last 20 years have seen a remarkable reduction in the operative morbidity associated with treatment of the descending thoracic aorta using thoracic endovascular aneurysm repair (TEVAR). To improve outcomes following arch repair, new TEVAR devices, including both single-branched and multibranched designs, have come to clinical trial. This review discusses the modern state of open and hybrid repairs while introducing the reader to technology for endovascular therapy of the aortic arch. We describe important anatomical and operative considerations for the devices. Given these nuances, we believe the future of the aortic arch to be patient-individualised hybrid repairs, involving both open and endovascular options with a multidisciplinary 'thoracic aorta team' at the helm.

Use of Inner Branches During Physician-Modified Endografting for Complex Abdominal and Thoracoabdominal Aortic Aneurysms

OBJECTIVES

Endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms have been performed widely in an increasing number of centers, utilizing custom-manufactured or physician-modified stent grafts containing fenestrations and side-arm branches for visceral and renal artery incorporation. Alternatively, inner branch configurations may be useful in complex anatomy, where application of fenestrations or side-arm branches can be challenging. Our study aims to evaluate the incidence of target vessel instability when incorporated with inner branch configurations, and report clinical outcomes of patients who underwent fenestrated/branched endovascular aortic repairs (F-BEVAR) containing one or more inner branches.

METHODS

We reviewed patients who underwent F-BEVAR with at least one inner branch configuration for complex abdominal or thoracoabdominal aortic aneurysms at Keck Hospital of University of Southern California from 2014 to 2020. Endpoints were mortality, major adverse events (MAE), technical success, and target vessel instability. Target vessel instability was assessed using follow-up computed tomography (CT) and duplex imaging.

RESULTS

Out of the 175 patients who underwent F-BEVAR for complex abdominal and TAAA during the study period, 17 patients had at least one inner branch configuration. All were deemed high-risk for open repair with multiple cardiovascular and/or pulmonary comorbidities. Eight (47%) patients had extent I, II, III thoracoabdominal aortic aneurysms, and 10 (59%) had prior aortic repairs. A total of 68 target vessels were incorporated (mean = 4 vessels/patient, range=1~6), of which 40% were inner branch configurations, most commonly for renal arteries. Technical success was 94.1%. There was one perioperative mortality due to massive myocardial infarction, as well as one patient who needed temporary hemodialysis. No device-related mortalities were observed. At 30 days, primary inner branch patency was 100% with no target vessel instability or reintervention. At mean follow-up of 5.8 months, the overall survival was 94% with one patient who expired from unknown cause. Overall primary inner branch patency was 96.3%, due to occlusion of a long lumbar artery branch with no clinical sequelae.

CONCLUSION

Inner branch configurations can provide a safe alternative technique of branch incorporation during complex endovascular aortic repair.

Endovascular Repair of Aortic Arch Aneurysm with a New Modular Double Inner Branch Stent Graft

Endovascular repair of an aortic arch aneurysm has made great progress in the last 10 years. Custom-made branched stent grafts have been used, and preliminary results have been promising. To reduce the effect of aortic arch anatomical variations on indications, we designed a new off-the-shelf modular double inner branch stent-graft system. This case is the "First-in-Man" study for the device. A 74-year-old man presented with an asymptomatic saccular aneurysm and an ulcer lesion of the aortic arch. Left common carotid artery (LCCA) and left subclavian artery bypass was performed before endovascular repair. The modular stents reconstructed the innominate artery and LCCA. A follow-up on the computed tomography angiography 6-month results showed that the new device is safe and feasible for patients who are unfit for conventional surgery.

Endovascular aortic repairs combined with looping-chimney technique for repairing aortic arch lesions and reconstructing left common carotid artery

Background

The aim of this retrospective study was to evaluate the feasibility and efficacy of thoracic endovascular aortic repairs (TEVAR) combined with looping chimney technique (LCT) for repairing aortic arch lesions and reconstructing left common carotid artery.

Methods

Total of 14 patients (mean age 52.86±14.46 years; range, 27–79; 10 men, 4 women) were included in the study from December 2016 to December 2018. Aortic arch pathologies of all patients with insufficient proximal landing zone (PLZ) were repaired by TEVAR under local anesthesia, before TEVAR, the left common carotid artery (LCCA) was protected by the guiding sheath from the retrograde brachial access, after aortic stent graft deployed, chimney graft was implanted to restore LCCA by LCT if necessary. All patients underwent computed tomography angiograph (CTA) 2 weeks, 3 months, 6 months and 1 year after surgery.

Results

Pathology results of 14 patients included: type B aortic dissection (n=8), penetrating aortic ulcers (n=1), retrograde type A aortic dissection (n=1), thoracic aortic aneurysm (TAA) (n=2), and thoracic aortic pseudoaneurysm (n=2). In all patients, aortic arch lesions were repaired by TEVAR; while LCCA were successfully reconstructed by the LCT. In one case, the innominate artery (IA) was simultaneously reconstructed through the same percutaneous right brachial artery (RBA) access. Coiling eliminated type Ia endoleak in 3 patients, and type II endoleak vanished by plugging left subclavian artery (LSA) in 2 patients. In four patients, the chimney stent (CG) of LCCA was partially compressed and then another bare stent was implanted to restore patency rate. The mean follow-up duration was 9.77±6.64 months (range, 0–24) and no combinations were observed in 13 patients; except in one patient who died of cerebral hemorrhage due to abnormal coagulation function.

Conclusions

TEVAR combined with LCT has shown to be suitable surgical approach for aortic arch lesions. Either covered intentionally or inadvertently, the LCCA could be safely and effectively reconstructed via percutaneous RBA access. Short-term follow-up demonstrated satisfactory morbidity and mortality in high-risk patients; however, longer follow-up is required to assess the effectiveness and durability of this innovative endovascular procedure.

Endovascular management of chronic post-dissection aneurysms of the aortic arch

This article reviews endovascular management of chronic post-dissection aneurysms of the aortic arch. Therapeutic strategies intended for this complex aortic condition are evolving rapidly to allow the treatment of various hostile aortic anatomy and frail patients. Principles, technical considerations, devices and outcomes of each technique are reviewed and summarized. Hybrid repair offer similar early mortality and stroke rates compared to open conventional surgery. Arch chimney and other parallel graft techniques present poor long term outcome, and should be limited to emergency situations where no other option is available. Fenestrated stent-grafting is subjected to many technical challenges in aortic arch due to difficulties in stent-graft orientation and fenestration positioning. In situ fenestration is an off-label technique that should only be used as an emergency bailout maneuver, considering that temporary coverage of supra aortic trunk vessel and its long-term durability raise concern. Finally, in experienced hands and appropriate anatomic conditions, arch branched graft technology has shown itself to be a safe and effective alternative to open conventional surgery. No randomized controlled trials have yet compared total endovascular aortic arch repair with hybrid techniques and open arch repair. The management of chronic post-dissection aneurysms of the aortic arch is challenging, decision-making and interventions should continue to be performed in high-volume centers with a dedicated aortic team with an expertise in both open and endovascular repairs.

The Position Relationship Between the Opening of the Three Branches of the Aortic Arch and the Aortic Arch Axis in Normal People

BACKGROUND

Due to the anatomical variability of the three branches of the aortic arch, interventional treatment of arch diseases becomes difficult. The aim of this study was to assess the position of three branches of the aortic arch in normal people and to provide reference data for the customization of aortic arch stents and simplified intraluminal treatment.

METHODS

A total of 120 patients who underwent computed tomography angiography examination of thoracic aorta in our institution were enrolled as per a set of inclusion and exclusion criteria from January 2018 to December 2018. Measurements were carried out using GEAW 4.6 workstation. The parameters recorded were the ratio of the distance from the point where the aortic branch opening intersects the aortic arch to the anterior wall of the aorta to the cross-sectional diameter of the aortic arch. Finally, the position relationship among the three branch openings was determined.

RESULTS

The position relationship among the three branches openings is divided into three categories. Type I: Two of the branch openings are completely surrounded by the boundary of the other branch. Type II: There is no inclusion relationship between the three branch openings. Type III: One branch opening is surrounded by the boundary of the other branch. In type I, there were 23 cases (19.2%); in type II, 37 cases (30.8%); and in type III, 60 cases (50%). These three position relationships were not significantly different between sexes and different ages (P > 0.05). These data were used to design a possible stent model.

CONCLUSIONS

This study reveals that the position of three aortic branches exhibits distinct patterns divided into 3 types. Based on measurements of the opening position of the three branches, the position relationship between the 3 branches can be obtained to provide a theoretical basis for the design of intraluminal stents and application of the simplified intracavity thoracic endovascular aneurysm repair technology.

Total Endovascular Aortic Arch Repair with Branched Graft

In selected cases, the utilization of branched endografts for the treatment of aortic arch aneurysms could be a safe and advantageous alternative to high-risk procedures such as open total aortic arch replacement or hybrid arch repair. We present the case of a 70-year-old man with saccular aneurysm of a bovine aortic arch which was endovascularly treated using a double-branched custom-made aortic endoprosthesis based on the Relay NBS (Non-Bare Stent) Plus platform intended for zone 0 deployment. The postoperative clinical course was uneventful. The postoperative computed tomography scan showed a good result of the implant. The patient was discharged 6 days after the procedure.

Debranching of Supra-aortic Vessels via Femoral Artery Inflow for Late Ascending Aortic Rupture

A 56-year-old man with a history of Marfan's syndrome, total arch replacement, descending thoracic endovascular aortic repair, and twice redo sternotomy for pseudoaneurysm repair, presented with a pulsatile chest mass secondary to a contained rupture of the ascending aorta. The patient underwent supra-aortic debranching via the superficial femoral artery and ascending thoracic stent-graft placement under continuous transesophageal echocardiography. Completion angiography demonstrated successful exclusion of the contained rupture. Postoperatively, the patient was neurologically intact, the pulsatile mass resolved, and the bypass grafts remained patent. Chronic respiratory failure and multidrug-resistant pneumonia led to late mortality. This case demonstrates that hybrid repair is effective in the emergent setting of ascending aortic rupture. Debranching of the ascending arch using the superficial femoral artery as inflow is feasible and provides adequate cerebral perfusion despite the length of the bypass. The use of transesophageal echocardiography during stent-graft deployment allows precise device placement in the high-risk area of the ascending aorta proximal to the innominate artery.

Case Series of Aortic Arch Aneurysm in Patients with Bovine Arch Treated with Proximal Scalloped and Fenestrated Stent Graft

PURPOSE

The bovine arch is the most common variant of the aortic arch and occurs when the innominate artery shares a common origin with the left common carotid artery. We report an endovascular repair of aortic arch aneurysm in patients with a bovine arch using the Najuta proximal scalloped and fenestrated stent graft.

MATERIALS AND METHODS

Thoracic endovascular aneurysm repairs using the Najuta stent graft were performed at our facility. It was inserted and deployed at a zone 0 with precise positional adjustment of the scallop of the stent graft to the brachiocephalic trunk.

RESULTS

Overall, eight patients with bovine aortic arch were treated with fenestrated endovascular aneurysm repair. Technical success was 100% with no 30-day death. The follow-up period ranged from 7 to 29 (median 12) months. None of the patients had a stroke or paraplegia, and no endoleak was observed. All brachiocephalic trunks scalloped, and the left subclavian artery fenestrated vessels remained patent during the follow-up period.

CONCLUSION

The Najuta stent graft repair of aortic arch aneurysms in patients with a bovine arch is a safe and effective treatment option, with good immediate and short-term results.

Fenestrated endovascular repair of aortic arch aneurysm in patients with bovine arch using the Najuta stent graft

We describe the case of a 74-year-old man with a thoracic aortic aneurysm with a bovine arch who underwent fenestrated endovascular repair of aortic arch aneurysm using the Najuta stent graft (Kawasumi Laboratories, Inc, Tokyo, Japan). He has had a previous endovascular aneurysm repair and femoropopliteal bypass for abdominal aortic aneurysm combined with peripheral arterial disease. The Najuta stent graft was inserted and deployed at zone 0 with delicate positional adjustment of the fenestration of the stent graft to the brachiocephalic trunk. There was no endoleak or complication. His postoperative course was uneventful. At 7-month follow-up, complete exclusion of the aneurysm was noted. The Najuta stent graft repair of aortic arch aneurysms is a safe and effective treatment option for patients with a bovine arch.

Endovascular arch replacement with a dual branched endoprosthesis

Background

In the light of current evidence, endovascular repair of aortic arch pathologies with custom-made devices should be considered a valid alternative to decrease operative mortality and morbidity associated with open or hybrid repair. Currently, two double inner branch devices are available on the market. Some papers from multicenter experiences have been published about the use of Cook device. We report our single-center experience with Bolton double branch stent graft in the treatment of aortic arch disease.

Methods

Between 2013 and 2016, nine high-risk patients with arch pathology were treated in our center with a Bolton custom-made branched device. Among these, two with a single branch model were excluded, leaving a subgroup of seven patients of this study.

Results

Out of the seven male patients (mean age, 76; range, 70-85) included in the study, two (28%) died perioperatively after stroke (14%) and retrograde dissection (14%), respectively. No other death, major complications, including aneurysmal diameter evolution and branch related complications, or secondary intervention was recorded at a mean follow up of 24 [6-53] months.

Conclusions

Despite the small sample size, our results are in line with the early experiences published on this technique. Endovascular repair of aortic arch disease with custom-made branched devices should always be considered to give high-risk patients a chance of repair.

The Medical Devices Special Access Program in Canada: A Scoping Study

New health technologies enter Canadian healthcare organizations in various ways, and understanding them is essential to the development of a pan-Canadian Health Technology Management (HTM) Strategy, now a priority of governments across Canada. One way is through Health Canada's Medical Devices Special Access Program (MDSAP), which permits unlicensed devices to be obtained by healthcare professionals. However, the circumstances around and implications of the current use of this program are not clear. A scoping literature review was conducted to clarify these and identify important roles and issues related to the MDSAP. Limited information was found on the MDSAP. Nevertheless, three themes demonstrating the roles of the MDSAP in HTM emerged: arbiter in technology selection, a route to technology procurement and facilitator of health technology innovation. No information suggesting that MDSAP is used to circumvent licensing was found. Rather, it enables desired patient outcomes and product commercialization.

Case series of aortic arch disease treated with branched stent-grafts

Background

Surgical repair of aortic arch pathology is complex and associated with significant morbidity and mortality. Alternative approaches have been developed to reduce these risks, including the use of thoracic stent-grafts with fenestrations or in combination with bypass procedures to maintain supra-aortic trunk blood flow. Branched stent-grafts are a novel approach to treat aortic arch pathology.

Methods

Consecutive patients with aortic arch disease presenting to a single university hospital vascular centre were considered for branched stent-graft repair (October 2010 to January 2017). Patients were assessed in a multidisciplinary setting including a cardiologist, cardiac surgeon and vascular surgeon. All patients were considered prohibitively high risk for standard open surgical repair. The study used reporting standards for endovascular aortic repair and PROCESS (Preferred Reporting of Case Series in Surgery) guidelines.

Results

Some 30 patients (25 men) underwent attempted branch stent-graft repair. Mean age was 68 (range 37–84) years. Eighteen patients had chronic aortic dissection, 11 patients had an aneurysm and one had a penetrating ulcer. Fourteen patients had disease in aortic arch zone 0, six in zone 1 and ten in zone 2. Twenty-five patients had undergone previous aortic surgery and 24 required surgical revascularization of the left subclavian artery. Technical success was achieved in 27 of 30 patients. Four patients had an endoleak (type Ia, 1; type II, 3). The in-hospital mortality rate was three of 30. Mean length of follow-up was 12·0 (range 1·0–67·8) months, during which time 12 patients required an aortic-related reintervention.

Conclusion

Repair of aortic arch pathology using branched stent-grafting appears feasible. Before widespread adoption of this technology, further studies are required to standardize the technique and identify which patients are most likely to benefit.

Hybrid and total endovascular repair of the aortic arch

Background

Recent advances in endovascular technology have enabled minimally invasive repair of the aortic arch, with specifically designed stent-grafts. This article reviews hybrid and total endovascular repair in the management of aortic arch pathology.

Methods

Studies relating to aortic arch management were identified using MEDLINE and Embase, focusing on endovascular repair.

Results

Hybrid arch repair is associated with an early mortality rate of some 12 per cent, and carries significant risk of stroke (up to 15 per cent), paraplegia (up to 6 per cent), retrograde dissection (up to 6·5 per cent) and proximal endoleak (6 per cent). Despite patients being of overall higher perioperative risk, hybrid repair has morbidity and early mortality rates comparable to those of open arch replacement. However, rates of freedom from aortic rupture or reintervention are significantly lower in the longer term, owing to the incidence of endoleak. Total endovascular arch repair may be achieved by the use of parallel stents or in situ fenestration in the emergency setting, or use of custom-made devices (scalloped, fenestrated or branched stent-grafts) in the elective setting. Reports of these relatively novel technologies suggest acceptable short-term outcomes, but long-term data are still awaited.

Conclusion

Repair of aortic arch pathology presents a formidable challenge for endovascular technology. Open aortic arch repair remains the standard in younger, fitter patients, but endovascular technology and experience continue to evolve with encouraging early outcomes and expanding indications.

Open Versus Endovascular or Hybrid Thoracic Aortic Aneurysm Repair

Thoracic aortic aneurysms are associated with significant morbidity and mortality. There are multiple underlying etiologies, including genetic abnormalities, that have important implications in their natural history. The variable histologic, anatomic, and clinical presentations necessitate careful consideration of available treatment options. Surgical repair of these aneurysms has been the mainstay of treatment; however, these approaches can carry a relatively high risk of morbidity and mortality. Endovascular approaches have now become first-line therapy for descending thoracic aneurysms, and with advancements in graft technology, endovascular approaches are being increasingly employed for hybrid repairs of the aortic arch and even the ascending aorta. However, to date, clinical outcomes from randomized trials and long-term follow-up are limited. As technology continues to advance, there is the potential for further integration of surgical and endovascular treatments so that patients have the best opportunity for a favorable outcome.

Minimally Invasive Techniques for Total Aortic Arch Reconstruction

The cumulative experience with endovascular aortic repair in the descending thoracic and infrarenal aorta has led to increased interest in endovascular aortic arch reconstruction. Open total arch replacement is a robust operation that can be performed with excellent results. However, it requires cardiopulmonary bypass and circulatory arrest and, therefore, may not be tolerated by all patients. Minimally invasive techniques have been considered as an alternative and include hybrid arch debranching, parallel stent graft deployment in the chimney and snorkel configurations, and complete endovascular branched reconstruction with multi-branched devices. This review discusses the evolving use of endovascular techniques in the management of aortic arch pathology and considers their relevance in an era of safe and durable open aortic arch reconstruction.

Endovascular and Operative Treatment of the Aortic Arch in a High-Risk Marfan Patient

In this case, we describe a combined endovascular and operative management for aortic arch repair in a 57-year-old Marfan patient with complex aortic arch geometry previously treated with several open surgeries for acute type A dissection. The patient, who was presented to our department with dorsal pain, deemed to be at high operative risk for another open aortic surgery due to massive aortic calcification. It is an unusual method of placing a custom-made stent-graft system in the false aortic lumen with operative and endovascular treatment of the supra-aortic vessels.

Endovascular repair of an innominate artery pseudoaneurysm using the Valiant Mona LSA branched graft device

A 60-year-old woman involved in a motor vehicle collision presented with a traumatic pseudoaneurysm of the innominate artery origin in addition to multiple concomitant injuries. She was classified as a high-risk candidate for open repair. An experimental thoracic branched graft device was used for coverage of the injury with the addition of a right carotid-to-left carotid-to-left subclavian artery bypass. Follow-up imaging showed resolution of the pseudoaneurysm and patency of her bypass grafts. This is the first described use of the Mona LSA Branch Thoracic Stent Graft System (Medtronic, Minneapolis, Minn) in the innominate artery.

Results From a Nationwide Registry on Scalloped Thoracic Stent-Grafts for Short Landing Zones

Purpose: To report the perioperative results and short-term follow-up of patients treated with scalloped thoracic stent-grafts. Methods: A multicenter registry in the Netherlands captured data on 30 patients (mean age 68 years; 17 men) with thoracic aortic pathology and a short (<20 mm) proximal or distal landing zone who received a custom-made scalloped stent-graft between January 2013 and February 2016. Patients were treated for saccular (n=13) aneurysms, fusiform (n=9) aneurysms, pseudoaneurysms (n=4), or chronic type B dissections (n=4). The scallop was used to preserve flow in the left subclavian artery (LSA) (n=17), left common carotid artery (n=5), innominate artery (n=1), and celiac trunk (n=7). In 7 (23%) patients, the scallop also included the adjacent artery. Results: Technical success was achieved in 28 (93%) patients. In 1 patient, a minor type Ia endoleak was observed intraoperatively, which was no longer visible on computed tomography angiography at 3 months. In another patient, the LSA was unintentionally obstructed due to migration of the stent-graft on deployment. Concomitant carotid-carotid or carotid-subclavian bypass was performed in 4 patients. There was no retrograde type A dissection or conversion to open surgery. In-hospital mortality was 3%, and the perioperative ischemic stroke rate was 3%. At a mean follow-up of 9.7 months (range <1 to 31), 29 of 30 target vessels were patent. Conclusion: The scalloped stent-graft appears to be a safe and relatively simple alternative for the treatment of thoracic aortic lesions with short landing zones. Larger patient series and long-term follow-up are required to confirm these early results.

Short- and Long-term Results of Hybrid Arch and Proximal Descending Thoracic Aortic Repair

Purpose: To evaluate the short- and long-term outcomes of hybrid repair of the arch and proximal descending aorta in a single tertiary center for aortic disease. Methods: A retrospective analysis was performed of 55 patients (median age 67 years; 36 men) who underwent hybrid repair of thoracic aortic pathology with involvement of the arch between January 2005 and May 2015 at a single tertiary center. The pathologies included 40 (73%) with aneurysmal disease, 10 (18%) acute type B aortic dissections, 2 with acute aortic syndrome, an acute type A dissection, and left and aberrant right subclavian artery aneurysms. Seven (13%) procedures were performed as an emergency. Demographics and procedure characteristics were collected for analysis of survival and reinterventions. Results: Complete aortic debranching was performed in 14 (25%) to facilitate endograft placement in zone 0; debranching was partial in 20 (36%) patients for zone 1 deployments and 21 (38%) for zone 2. Primary technical success was achieved in 51 (93%) cases. One patient died in-hospital from aneurysm rupture following aortic debranching prior to stent-graft repair. In another, the stent-graft procedure proved infeasible and was abandoned. The other 2 technical failures were due to type Ia endoleaks. Five (9%) patients died in-hospital (4 of 48 elective and 1 of 7 emergency cases); 2 of these patients died within 30 days (4%). Eight (14%) patients had a stroke, 6 of 48 elective and 2 of the 7 emergency patients. Spinal cord ischemia was reported in 3 (6%) patients. Mean follow-up was 74.6 months. Overall cumulative survival was 70% at 1 year, 68% at 2 years, and 57% at 5 years. Reintervention to the proximal landing zone for type Ia endoleak was required in 6% of cases. The overall rate of aortic reintervention was 18% at 1 year, 21% at 2 years, and 36% at 5 years. Overall extra-anatomic graft patency was 99%. Conclusion: Hybrid repair of the aortic arch and proximal descending thoracic aorta is technically feasible, with acceptable short-term mortality. There is a low rate of proximal landing zone reintervention when hybrid techniques are used to create an adequate proximal landing zone. Extra-anatomic bypass grafts have good long-term patency. Ongoing disease progression means that further distal aortic interventions are often necessary in patients with extensive disease.

Complete Antegrade Transapical Deployment of a Branched Aortic Arch Endograft: A Porcine Feasibility Study

PURPOSE

To describe and prove the concept of a technique for complete transapical deployment of a single-branch aortic arch endograft in a porcine model.

METHODS

Eight domestic pigs underwent antegrade transapical delivery of a single-branch arch endograft, including a mating stent-graft to the innominate artery. Technical feasibility, operating time, radiation parameters, and hemodynamic changes were studied according to a standardized protocol during baseline (T0), after establishing the transapical access and through-and-through wire (T1), and after stent-graft deployment (T2). Myocardial and cerebral blood flow status was assessed using fluorescent microspheres (FM) and transit-time flow measurement (TTFM) monitoring.

RESULTS

Transapical access, introduction and deployment of the endograft, side branch catheterization, and deployment of the mating stent-graft were feasible in 6 of 8 animals. One animal died due to irreversible heart rhythm disorders and one due to accidental graft rotation during deployment, resulting in unintended coverage of the innominate artery. The mean operating and fluoroscopy times were 223±11 minutes and 27.2±6.3 minutes, respectively. During introduction and deployment of the stent-graft, transient aortic valve insufficiency occurred in all animals. Hemodynamic stability recovered within 10 minutes after retrieval of the delivery system in all animals. The innominate artery was patent, with unchanged TTFM measurements throughout the procedure. FM evaluation revealed stable cerebral blood flow.

CONCLUSION

An antegrade transapical access to the aortic arch for implantation of a single-branch endograft is feasible in a porcine model with reversible impact on hemodynamic measures during deployment. Transapical access allows deployment of a complex endograft through a single large-bore access site in a porcine model.

Evolving practice pattern changes and outcomes in the era of hybrid aortic arch repair

OBJECTIVE

The role of hybrid repair in the management of aortic arch pathology, and long-term outcomes with these techniques, remains uncertain. We report a decade of experience with hybrid arch repair (HAR) and assess institutional practice patterns with regard to the use of hybrid and open techniques.

METHODS

Hybrid and open total and distal arch procedures performed between July 2005 and January 2015 were identified from a prospectively maintained, institutional aortic surgery database. Perioperative morbidity and mortality, freedom from reintervention, and long-term survival were calculated. Hybrid and open procedural volumes over the study period were assessed to evaluate for potential practice pattern changes.

RESULTS

During the study period 148 consecutive procedures were performed for repair of transverse and distal aortic arch pathology, including 101 hybrid repairs and 47 open total or distal arch repairs. Patients in the hybrid repair group were significantly older with a greater incidence of chronic kidney disease, peripheral vascular disease, and chronic lung disease. Perioperative mortality and outcomes were not significantly different between the hybrid and open groups, aside from decreased median length of stay after hybrid repair. Need for subsequent reintervention was significantly greater after hybrid repair. Unadjusted long-term survival was superior after open repair (70% 5-year survival open vs 47% hybrid; P = .03), although aorta-specific survival was similar (98% 5-year aorta-specific survival open vs 93% hybrid; P = .59). Institutional use of HAR decreased over the final 3 years of the study, with an associated increased use of open total or distal arch repairs. This was primarily the result of decreased use of native zone 0 hybrid procedures. Concurrent with this apparent increased stringency around patient selection for HAR, perioperative morbidity and mortality was reduced, including avoidance of retrograde type A dissection.

CONCLUSIONS

HAR remains a viable option for higher-risk patients with transverse arch pathology with perioperative outcomes and long-term aorta-specific survival similar to open repair, albeit at a cost of increased reintervention. This observational single-institution study would suggest decreased use in more recent years in favor of open repair due to avoidance of native zone 0 hybrid procedures. This decline in the institutional use of native zone 0 hybrid repairs was associated with improved perioperative outcomes.

Transcardiac endograft delivery for endovascular treatment of the ascending aorta: a feasibility study in pigs

PURPOSE

To compare the technical feasibility and hemodynamic alterations during antegrade transcardiac access routes vs conventional transfemoral access (TFA) for endovascular treatment of the ascending aorta in a porcine model.

METHODS

Antegrade transseptal access (TSA), transapical access (TAA), and TFA were used for implantation of custom-made endografts into the ascending aorta under fluoroscopy (6 pigs each). Hemodynamic parameters, myocardial and cerebral blood flow, and carotid artery blood flow were evaluated during baseline (T1), sheath advancement (T2), after sheath retraction (T3), and after endograft deployment (T4).

RESULTS

Endograft deployment was feasible in all animals; all coronary arteries remained patent. Hemodynamic parameters were comparable in all 3 study groups during all measurements. During T2, transient hemodynamic alteration occurred in all groups, with transient severe valve insufficiency in TSA and TAA reflected by the higher pulmonary to mean arterial pressure ratio (p<0.05) as compared with TFA. Values stabilized again at T3 and remained stable until T4. The innominate artery was partially occluded in 4 (TSA), 3 (TAA), and 5 (TFA) animals. There was no deterioration of myocardial or cerebral perfusion during the procedures. Endograft deployment and fluoroscopy times during TAA were shorter than in TSA and TFA.

CONCLUSIONS

TSA, TFA, and TAA to the ascending aorta are feasible for endograft delivery to the ascending aorta in a porcine model. Transient hemodynamic instability in TSA and TAA recovered to near preoperative values. TAA appeared technically easier.

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.

Anatomic feasibility of endovascular reconstruction in aortic arch aneurysms

The purpose was to estimate the proportion of current open aortic arch reconstructions that might be feasible for endovascular repair. From all elective repair made in Southern Sweden in one center between 2005 and 2012, 129 open and eight endovascular aortic arch repairs were identified. The anatomy of the ascending arch and descending aorta as well as the arch vessels was categorized from multiplanar and axial computed tomography scans. Of 129 open cases, only two (1.5%) were suitable for endovascular repair. Among 137 all arch open and endovascular arch reconstructions performed during the study period, only 10 (7%) were candidates for endovascular repair. The most common exclusion for endovascular repair was an excessively large ascending aortic diameter. In conclusion, only a small proportion of patients having an open arch repair are suitable for endovascular arch repair, a finding related to the large diameter of the ascending aorta.

Thoracic aortic frontier: review of current applications and directions of thoracic endovascular aortic repair (TEVAR)

Thoracic endovascular aortic repair, a minimally invasive technique is replacing the maximally invasive gold standard of thoracotomy and replacement of the descending thoracic aorta. With experience, indications have expanded to encroach on the arch and even ascending aorta. This review highlights the current state of technology, discusses controversies, and takes the perspective of a forward-thinking review to describe novel, innovative techniques that might make the entire thoracic aorta amenable to minimally invasive repair.

Total endograft replacement of aortic arch

Total endovascular replacement of the aortic arch is a complex procedure that is often favoured when the pathology anatomy precludes a standard median sternotomy. Here we present the case of endograft repair in a 79 year old male with 6.5 cm arch aneurysm and 5.4 cm descending thoracoabdominal aneurysm. Following bilateral carotid-subclavian bypasses, a long 7 Fr sheath was advanced into the descending aorta through the common iliac artery purse string. A double curved long Lunderquist wire was guided to deep within the left ventricle, and the endograft carefully advanced over the wire. The graft was radiologically orientated, and deployed under asystolic conditions. Retrograde cannulation of the branches were accomplished, with carotid sheath placed into the branches followed by bridging stents. The graft delivery system was then removed. This approach obviates the need for a sternotomy, cumbersome extra-anatomic debranching, and hypothermic circulatory arrest.