Coverage of the left subclavian artery without revascularization during thoracic endovascular repair is feasible: a prospective study

Hemodynamic changes for half cover left subclavian artery ostium during thoracic endovascular aortic repair

Purpose

Some clinicians use endografts to cover half the left subclavian artery (LSA) ostium to cure some cases with insufficient proximal landing zone (PLZ) in thoracic endovascular aortic repair (TEVAR) treatment. We used computational fluid dynamics (CFD) to study the hemodynamic changes in the LSA because they may cause acute thrombosis or arteriosclerosis.

Methods

The digital model of the aortic arch was established and named model A, which only included the supraarch branch of the LSA. By directly covering half of the LSA ostium, which was named as model B. All established models were imported into the Gambit grid division software for grid division and were subsequently imported into the Fluent software for hemodynamic numerical simulation and calculation to analyze the related changes in LSA hemodynamic parameters after stent implantation.

Results

Under the same aortic inlet flow, in model B, the local blood flow velocity of the LSA ostium increased and the whole blood flow velocity at the distal end decreased. The average wall shear stress (WSS) of the LSA was significantly decreased. Meanwhile there was an obvious turbulent flow in the LSA lumen, and the related blood flow state was disordered.

Conclusion

CFD research confirmed that the implantation of an endograft covering half the LSA ostium can cause obvious hemodynamic changes, which is likely to cause a long-term arteriosclerosis or acute thrombosis of the LSA, finally increasing the risk of stroke. Once this operation is performed in some specific clinical cases for simplicity and economy, it seems that we should actively antiplatelet and follow up regularly.

In-hospital thromboembolic complications after frozen elephant trunk aortic arch repair

OBJECTIVE

This study evaluated the frequency and clinical impact of thromboembolic complications after frozen elephant trunk aortic arch repair using the Thoraflex device (Terumo Aortic).

METHODS

A total of 128 consecutive patients (mean age 67.9 ± 13.7 years, 31.0% female) underwent frozen elephant trunk aortic arch repair using the Thoraflex device between September 2014 and May 2021 in 4 Canadian centers. Patient baseline characteristics, intraoperative details, and frozen elephant trunk thromboembolic complications were collected retrospectively and analyzed.

RESULTS

Fifteen patients (11.7%) had thrombus visualized within the frozen elephant trunk stent graft on imaging (n = 8; 53.3%) or had a thromboembolic event (n = 9; 60.0%) before hospital discharge. Sites of embolism were mesenteric (n = 8; 88.9%), renal (n = 4; 44.4%), and iliofemoral (n = 1; 11.1%). Patients who experienced thromboembolic complications were more likely to have a history of autoimmune disease (n = 3; 20.0% vs n = 2; 1.8%; P = .01) and implantation of a longer frozen elephant trunk stent graft (150 mm vs 100 mm) (n = 13; 86.7% vs n = 45; 39.8%; P < .001). All patients with thromboembolic complications received therapeutic anticoagulation, and a smaller proportion required an open surgical (n = 5; 33.3%) or an endovascular (n = 2; 13.3%) intervention. Radiographic resolution of thromboembolic complications was observed in 86.7% of patients (n = 13). In-hospital mortality occurred in 1 patient, stroke occurred in 1 patient, and transient spinal cord injury occurred in 1 patient.

CONCLUSIONS

Thromboembolic complications occur more often than previously recognized after frozen elephant trunk aortic arch repair using the Thoraflex device and are associated with increased rates of surgical and endovascular reintervention. Prevention and management of these complications require further study.

Atypical presentation of subclavian steal syndrome with left sided sensorineural deafness

We present a rare manifestation of a common pathology: left sided sensorineural hearing loss secondary to subclavian steal syndrome after thoracic endovascular aortic repair for complicated acute aortic dissection. We describe the vascular physiology that can result in unilateral hearing loss and provide a brief review of subclavian steal syndrome. This case report highlights the importance of avid clinical recognition of an atypical presentation of a common vascular disease.

How to Treat Type B Aortic Dissections in the Presence of an Aberrant Right Subclavian Artery: A Systematic Review

An aberrant right subclavian artery (ARSA) is the most common congenital variant of the aortic arch. Usually, this variation is largely asymptomatic, but sometimes it may be involved in aortic dissection (AD). Surgical management of this condition is challenging. The therapeutic options have been enriched in recent decades by establishing individualized endovascular or hybrid procedures. Whether these less invasive approaches bear advantages, and how they have changed the treatment of this rare pathology, is still unclear. Therefore, we conducted a systematic review. We performed a review of literature from the past 20 years (from January 2000 until February 2021) complying with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. All reported patients treated for Type B AD in the presence of an ARSA were identified and classified into three groups according to the received therapy (open, hybrid, and total endovascular). Patient characteristics, as well as in-hospital mortality, and major and minor complications were determined and statistically analyzed. We identified 32 relevant publications comprising 85 patients. Open arch repair has been offered to younger patients, but significantly less often in symptomatic patients needing urgent repair. Therefore, the maximum aortic diameter was also significantly larger in the open repair group compared with that in the hybrid or total endovascular repair group. Regarding the endpoints, we did not find significant differences. The literature review revealed that open surgical therapies are preferred in patients presenting with chronic dissections and larger aortic diameters, most likely because they are unsuitable for endovascular aortic repair. Hybrid and total endovascular approaches are more often applied in emergency situations, where aortic diameters remain smaller. All therapies demonstrated good, early, and midterm outcomes. But, these therapies carry potential risks in the long term. Therefore, long-term follow-up data are urgently needed to validate that these therapies are sustainable.

MANAGEMENT OF LEFT SUBCLAVIAN ARTERY IN TYPE-B AORTIC DISSECTION TREATED WITH THORACIC ENDOVASCULAR AORTA REPAIR

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) has been the favored approach for the treatment of type B aortic dissection (TBAD). To obtain an adequate proximal landing zone, coverage of the left subclavian artery (LSA) will often be necessary. The occurrence of possible neurologic complications has continued to be debated. We investigated the management of the LSA in patients with TBAD undergoing endovascular repair.

METHODS

We searched the PubMed and MEDLINE databases to October 2020 for studies of TEVAR for TBAD. Data on the study design, demographics, endograft details, LSA coverage and revascularization, mortality, complications, and follow-up were extracted and analyzed. The effects of LSA coverage and revascularization on neurologic complications and outcomes were investigated.

RESULTS

A total of 26 reports (24 retrospective and 2 prospective) were deemed eligible for our study. A total of 1483 patients (mean age, 56.9 ± 6.2 years) had undergone TEVAR for acute (n = 932; 62.9%), subacute (n = 36; 2.4%), or chronic (n = 515; 34.7%) TBAD, with a success rate of 97.8% and hospital mortality of 4.9%. The LSA origin had been covered for 707 patients (47.7%), and 326 had undergone LSA revascularization (surgical, n = 96; endovascular, n = 170; unspecified or not reported, n = 60). LSA revascularization was concomitant for 68.1% of cases, after TEVAR for 1.8%, and not reported for 30.1%. Of 1146 patients, 10 (0.9%) had experienced left arm claudication, and the overall stroke rate was 3.3% (2.7% for the LSA group and 1% for the uncovered LSA group; P = .0815). Of the patients with stroke and a covered LSA, 1% (2 of 203) had undergone LSA revascularization and 4.8% (5 of 105) had not (P = .0478). Twenty-six patients (1.9%) had developed paraplegia: 0.7% (3 of 433) with a covered LSA, 1.4% (7 of 491) with an uncovered LSA (P = .3508), and not reported for 16 patients. Endoleak was present in 138 patients (13.4%) at a mean follow-up of 32.1 ± 25.6 months.

CONCLUSIONS

Our review has shown that LSA coverage during endovascular repair for complicated TBAD will does not significantly increase the risk of neurologic complications; however, revascularization of the LSA should be always recommended.

Headache may be the only symptom of subclavian steal syndrome after thoracic endovascular aortic repair

Thoracic endovascular aortic repair (TEVAR) is currently the treatment of choice for thoracic aortic disease. In select cases, the TEVAR stent must occlude the left subclavian artery. This is usually well tolerated, but the subclavian steal syndrome (SCSS) may occur. Vertebrobasilar insufficiency can cause headaches, but reports of headache as the only symptom of SCSS are very rare. Thus, this may be under-recognised. To increase the awareness of this complication we describe the course of a patient who developed chronic intermittent headaches after intentional occlusion of the left subclavian artery with a TEVAR stent. Revascularisation may be required to prevent adverse neurological outcomes from SCSS. Some authors recommend prophylactic revascularisation whenever the left subclavian artery is sacrificed during TEVAR. However, transposition or bypass of this artery is not without risk and mild symptoms, such as secondary headache, can be fully controlled with conservative measures that reduce steal pathophysiology.

Covering/Overstenting of the left subclavian artery (LSA) in thoracic endovascular repair (TEVAR) to treat various thoracic/thoracoabdominal aortic lesions: Is revascularization of the left arm a must? (A retrospective cohort study with 12 years of experience to describe the real-world situation of daily clinical practice and the literature review)

Background: Pathologies of the descending thoracic aorta inwardly extended towards the aortic arch actually shorten the proximal landing zone for aortic prosthesis. This, in turn, worsens the feasibility of the aorta for endovascular therapeutic options of those pathologies. Objective: This work considers the blockage of the left subclavian artery (LSA) through endovascular treatment of the pathologies of the descending aorta as a main work question, which is based on the hypothesis that there is no necessity for primary standard revascularization of the LSA in TEVAR with LSA covering. The researchers have 12 years of experience in treatment of different thoracic aortic lesions. Their experience will also be reviewed in this paper. Design: Retrospective unicenter cohort study in consecutive patients order to describe the real-world situation of daily clinical practice Material: All the patients who had undergone endovascular, hybrid, or open operative therapy of variant pathologies of descending aorta were included in this study. Methods: Various parameters were investigated, including therapeutic procedures such as i) pure endovascular vs. hybrid; ii) year of therapy; iii) symptomatic vs. asymptomatic status of the patients; iv) variant epidemiological factors (age, sex, risk factors, mortality, and follow up); v) overstenting/blocking of the LSA; vi) complications of applied therapies; vii) further operations/interventions to treat such complications; viii) radiologic aortic measurements (such as lumen extensions, false lumen measurements, distance to the supra-aortic and visceral vessels); and ix) multiple other pathological features. Different statistical parameters were also examined. Survival was analysed by the Kaplan–Meier assessment in the group of whole patients vs. the group of over-stented patients. Here the analysis of variance is performed for the independent parameters for the revascularized patients—not the revascularized patients—who had undergone LSA coverage. For statistical approval, U-test was used. The p-value < 0.05 was considered significantly different. The literature review was achieved by a search in PubMed, Google scholar, Research Gate, ScienceDirect, and Cochrane library by using the following terms endovascular, TEVAR, revascularization, stroke, and left-subclavian-artery ischemia. The literature is classified accordingly in relation to the main topic. In fact, the literature undergoes further analysis if it goes with or against our hypothesis. Results: Overall, 112 patients were enrolled in the study. There was no significant difference comparing the not-revascularized vs. the revascularized group of patients, considering the consequences on cerebrovascular blood circulation (in particular, n=1 case [4.8 %] vs. no case [0 %]; p=1) or the spinal cord ischemia (n=2 [9.5 %] vs. n=1 [7.1 %]; p=1). As the main result, there was no case of manifest left arm ischemia and deaths (mortality, 0). Survival was in both groups as follows: 22 [95% CI, 14.154–29.904] months vs. 43 [95% CI, 33.655–51.921] months with no significant statistical difference (p>0.05) . The only statistically significant risk factor found was renal insufficiency (p, 0.028), but this too is considered a trend by the urgency of revascularization. Postoperatively, pneumonia showed a trend of higher frequency (p=0.058) in the revascularized cases (n=0 in the not-revascularized vs. n=3 [21.4 %] in the revascularized cases). There was no significant difference in the occurance of postoperative neurovascular complications (such as cerebrovascular accidents, spinal cord ischemia, or left arm ischemia) by comparing the groups of not-revascularized and revascularized patients. Conclusion: The revascularization of the overstented LSA due to TEVAR should be limited to certain indications, including i) the inadequate intracerebral circle of Willis; ii) the predominantly perfused left vertebral artery with inadequate blood perfusion via the right vertebral artery (e.g., by stenosis), iii) anatomic variance such as the left vertebral artery originating directly from the aortic arch (and must be blocked by TEVAR); iv) the need of an adequate left internal thoracic artery for coronary-artery-bypass grafting (CABG); v) the need of patent LSA for the dialysis shunt of the left arm. However, there is no appropriate evidence as yet based on sufficient study results achieved in trials with an advanced design (such as [double-]blind, multicenter randomized study) that appears to be urgently required.

Aortic-related Readmission after Thoracic Endovascular Aortic Repair for Type B Aortic Dissection Patients: A Single-center Retrospective Study

OBJECTIVES

This study aimed to investigate the characteristics of and risk factors for aortic-related readmission after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD).

METHODS

Data from TBAD patients who underwent TEVAR from 2009-2018 at a Chinese tertiary center were retrospectively collected and analyzed. Enrolled patients were categorized into two groups according to whether aortic-related readmission occurred during follow-up, which was defined as hospitalization at least once after the initial procedure due to events that were related to or caused by aortic dissection or the initial procedure.

RESULTS

A total of 1 288 TBAD patients were enrolled, and 99 patients experienced aortic-related readmissions (7.7%), among whom chronic patients had the highest readmission rate (9.8%). The yearly proportion of readmission during the first year after initial procedure revealed a decreasing trend with a -9.7% annual percentage change. Seventy-one patients underwent reintervention (71.7%). Distal aneurysmal degeneration (43.7%) and distal stent graft-induced new entries (32.4%) were two major causes for reintervention. Fourteen patients in the reintervention subgroup underwent a second reintervention (19.7%). In-hospital mortality was 1.0% during the readmission and 14.3% during the second readmission. The overall survival was comparable between two groups (p=.93).

CONCLUSIONS

This study highlighted the importance of surveillance after initial procedure for TBAD patients with potential risk factors for aortic-related readmission, and the predisposition of patients with reintervention to multiple readmissions deserves attention.

Management of Postoperative Complications Following Endovascular Aortic Aneurysm Repair

Endovascular aneurysm repair (EVAR) is a minimally invasive therapeutic approach to manage abdominal aortic pathologies (eg, aneurysm and dissection). EVAR was first introduced in 1991. In 1994, endovascular technique was also applied for thoracic aorta, thoracic endovascular aortic repair (TEVAR). In recent decades, EVAR has become an acceptable first-line treatment with 50% utilization rate across most practices, especially in high-risk patients. The safety profile of EVAR is comparable to the open approach, with superiority in terms of perioperative mortality and morbidity. This article summarizes the most common complications following EVAR/TEVAR and the most current treatment modalities across practices.

In Situ Laser Fenestration for Delayed Left Subclavian Artery Revascularization Following Thoracic Endovascular Aortic Repair of Type B Aortic Dissection

In situ laser fenestration (ISLF) is currently used to reconstruct the aortic major branches during thoracic endovascular aortic repair (TEVAR). To our knowledge, there have been no reports on the application of ISLF for delayed revascularization of the LSA previously sealed in TEVAR. This report describes 5 patients who underwent ISLF for delayed LSA revascularization, with a technical success rate of 80%. No endoleakage occurred, and stents remained patent during more than 6-month follow-up. ISLF is an effective, safe and minimally invasive method for delayed revascularization of the LSA following TEVAR for type B aortic dissection (TBAD) when patients are selected appropriately.

A multicenter "real-world" study of the valiant NAVION stent graft

BACKGROUND

The aim of the present study was to evaluate early results of thoracic endovascular aortic repair (TEVAR) using the Valiant Navion™ stent graft in a "real-world" scenario.

METHODS

All patients who underwent TEVAR with the Valiant Navion™ endograft between November 2018 and November 2019 were included in this retrospective multicenter study (six European centers). The primary endpoints were technical success, incidence of major adverse events (MAEs), access failure, deployment failure, deployment accuracy, and rate of intraoperative endoleaks (ELs).

RESULTS

One hundred-sixteen patients with varying thoracic aortic diseases were included. Eighteen patients (15.5%) were treated for an off-label condition. The technical success rate was 100%, without any access or deployment failures. The proximal and distal deployment accuracy rates were 99.1% and 97.4%, respectively. There were no intraoperative MAEs, including death. Two (1.7%) type Ib ELs were detected at the first postoperative CTA, all of which were in off-label procedures and related to the short length of the sealing neck. No type III ELs were detected. The median hospitalization time was 8 days (IQR 4-12), including a median intensive care unit stay of 1 day (IQR 1-2). The in-hospital mortality rate was 4.3%. At a median follow-up time of 98 days (IQR 39-187), there were no aortic-related mortalities or new onset of endoleaks.

CONCLUSION

Our initial experience with the Valiant Navion™ endograft in a wide variety of aortic diseases showed safe early outcomes, especially for on-label procedures.

Midterm Outcomes of Endovascular Repair for Stanford Type B Aortic Dissection with Aberrant Right Subclavian Artery

PURPOSE

To evaluate the early and midterm outcomes of endovascular repair of Stanford type B aortic dissection (TBAD) with an aberrant right subclavian artery (ARSA).

MATERIALS AND METHODS

From November 2012 to July 2018, 15 patients (13 male, 2 female) who had TBAD with ARSA underwent total endovascular repair, including thoracic endovascular aortic repair (TEVAR), left subclavian artery (LSA) chimney technique, LSA fenestration technique, and double chimney technique (LSA chimney and ARSA periscope). The mean age was 55 years. Kommerell diverticulum (KD) occurred in 2 patients, which were covered by means of oversized aortic stents. All patients had preoperative imaging examinations for assessing cerebral blood flow and the dominant vertebral arteries.

RESULTS

All procedures were completed successfully. There was no in-hospital mortality. The mean procedural time was 98 ± 40 minutes (range 50-190). The mean preoperative diameters of the maximum descending aorta, false lumen, and true lumen in the descending aorta versus postoperative were 37 ± 10 mm (range 28-67), 18 ± 9 mm (range 9-41), and 19 ± 6 mm (range 10-35) versus 34 ± 9 mm (range 25-64), 5 ± 8 mm (range 0-28), and 28 ± 5 mm (range 19-37), respectively. Right upper extremity weakness was observed in 2 patients, which recovered gradually during follow-up. Immediate type Ia endoleak was detected in 1 patient. The mean follow-up time was 33 ± 20 months. During follow-up, no ARSA steal syndrome, spinal cord ischemia, or strokes were not observed.

CONCLUSIONS

Endovascular treatment for TBAD with ARSA was feasible and safe with a satisfactory midterm follow-up outcome.

A simple patient-tailored aortic arch tangential angle measuring method to achieve better clinical results for thoracic endovascular repair of type B aortic dissection

Background

To report a simple individual tailored aortic arch tangential angle (θ-AATA) measuring method and its clinical application efficacy in the endovascular treatment of type B aortic dissection (AD).

Methods

From January 2013 to December 2014, acute type B AD patients were prospectively enrolled and treated with endovascular therapy in our center. Among these patients, a specific method was applied to measure θ-AATA based on the axial images of the CT scan. The length of proximal landing zone (PLZ) of each patient was measured at the routinely applied left-anterior oblique (LAO) 45-degree and θ-AATA. Respective treatment strategies based on the length of the PLZ were planned accordingly, and the stent-graft was deployed under the fluoroscopy at θ-AATA. The occurrence of immediate type I endoleak was recorded during the completion angiogram, while the alignment of the proximal marks was determined under fluoroscopy at θ-AATA and at LAO-45-degree as well.

Results

Totally 76 patients with type B AD were prospectively enrolled. The average value of θ-AATA was 58.3±5.2 degrees, which was significantly larger than the routine 45 degrees (P<0.01). The mean landing zone length measured under θ-AATA (18.4±3.9 mm) was longer than that (15.9±3.1 mm) obtained at the routine LAO-45 degrees (P<0.05). Stent-grafts' deployment strategies were substantially changed accordingly. Alignment of the proximal marks was achieved in 72 patients (93.4%) under θ-AATA and only in two patients (2.7%) at LAO-45 degrees (P<0.01). All stent-grafts' implantation was successfully completed. No major type I endoleak was found in the immediate post-deployment angiography.

Conclusions

It is easy to apply this patient-tailored θ-AATA measuring method in clinical practice. This more precise measurement is benefit for more reasonable treatment strategy planning, more precise deployment, and therefore a better outcome.

Complications of endovascular aneurysm repair of the thoracic and abdominal aorta: evaluation and management

In recent decades, endovascular aneurysm repair or endovascular aortic repair (EVAR) has become an acceptable alternative to open surgery for the treatment of thoracic and abdominal aortic aneurysms and other aortic pathologies such as the acute aortic syndromes (e.g., penetrating aortic ulcer, intramural hematoma, dissection). Available data suggest that endovascular repair is associated with lower perioperative 30-day all-cause mortality as well as a significant reduction in perioperative morbidity when compared to open surgery. Additionally, EVAR leads to decreased blood loss, eliminates the need for cross-clamping the aorta and has shorter recovery periods than traditional surgery. It is currently the preferred mode of treatment of thoracic and abdominal aortic aneurysms in a subset of patients who meet certain anatomic criteria conducive to endovascular repair. The main disadvantage of EVAR procedures is the high rate of post-procedural complications that often require secondary re-intervention. As a result, most authorities recommend lifelong imaging surveillance following repair. Available surveillance modalities include conventional radiography, computed tomography, magnetic resonance angiography, ultrasonography, nuclear imaging and conventional angiography, with computed tomography currently considered to be the gold standard for surveillance by most experts. Following endovascular abdominal aortic aneurysm (AAA) repair, the rate of complications is estimated to range between 16% and 30%. The complication rate is higher following thoracic EVAR (TEVAR) and is estimated to be as high as 38%. Common complications include both those related to the endograft device and systemic complications. Device-related complications include endoleaks, endograft migration or collapse, kinking and/or stenosis of an endograft limb and graft infection. Post-procedural systemic complications include end-organ ischemia, cerebrovascular and cardiovascular events and post-implantation syndrome. Secondary re-interventions are required in approximately 19% to 24% of cases following endovascular abdominal and thoracic aortic aneurysm repair respectively. Typically, most secondary reinterventions involve the use of percutaneous techniques such as placement of cuff extension devices, additional endograft components or stents, enhancement of endograft fixation, treatment of certain endoleaks using various embolization techniques and embolic agents and thrombolysis of occluded endograft components. Less commonly, surgical conversion and/or open surgical modification are required. In this article, we provide an overview of the most common complications that may occur following endovascular repair of thoracic and AAAs. We also summarize the current surveillance recommendations for detecting and evaluating these complications and discuss various current secondary re-intervention approaches that may typically be employed for treatment.

Type II Endoleaks, Left-Arm Complications, and Need of Revascularization after Left Subclavian Artery Coverage for Thoracic Aortic Aneurysms Endovascular Repair: A Systematic Review

BACKGROUND

The status of the left arm, the need of revascularization, and the occurrence of type II endoleakes from de left subclavian artery (LSA) after intention LSA coverage for thoracic aortic aneurysm endovascular repair need to be better understood. This systematic review was developed for contributing with such issue.

METHODS

Systematic literature review of studies published from January 2000 through December 2015 identified 7 studies comprising 201 patients submitted to elective endovascular repair for thoracic aortic aneurysms requiring intentional LSA coverage. Outcomes of interest included left-arm complications (ischemia, symptoms of claudication, and subclavian steal syndrome [SSS]) requiring postoperative revascularization of LSA, as well as endoleaks from the subclavian artery requiring postoperative embolization of LSA.

RESULTS

Left-arm complication rate was 4.5% (9 patients), requiring postoperative revascularization of LSA in 1 case (0.5%) of SSS. Type II endoleaks from the subclavian artery requiring postoperative embolization of LSA were reported in 2 cases (1.0%).

CONCLUSIONS

Low-quality evidence suggests very low rates of arm complications with need of LSA revascularization and of type II endoleaks requiring embolization in elective endovascular treatment of thoracic aortic aneurysms with intentional coverage of LSA without prophylactic revascularization of LSA.