Further consideration for subclavian revascularization with TEVAR

Comparison of total percutaneous in situ microneedle puncture and chimney technique for left subclavian artery fenestration in thoracic endovascular aortic repair for type B aortic dissection

OBJECTIVE

To compare the outcomes of totally percutaneous in situ microneedle puncture for left subclavian artery (LSA) fenestration (ISMF) and chimney technique in type B aortic dissection (TBAD) during thoracic endovascular aortic repair (TEVAR).

MATERIALS AND METHODS

Data on patients who underwent either chimney-TEVAR (n = 89) or ISMF-TEVAR (n = 113) from October 2018 to April 2022 were analyzed retrospectively. The primary outcomes were mortality and major complications at 30 days and during follow-up.

RESULTS

The technical success rate was 84.3% in the chimney group and 93.8% in the ISMF group (p = 0.027). The incidence of immediate endoleakage was significantly higher in the chimney than ISMF group (15.7% vs 6.2%, respectively; p = 0.027). The 1- and 3-year survival rates in the chimney and ISMF groups were 98.9% ± 1.1% vs 98.1% ± 0.9% and 86.5% ± 6.3% vs 92.6% ± 4.1%, respectively (log-rank p = 0.715). The 3-year rate of cumulative freedom from branch occlusion in the chimney and ISMF group was 95.4% ± 2.3% vs 100%, respectively (log-rank p = 0.023).

CONCLUSION

Both ISMF-TEVAR and chimney-TEVAR achieved satisfactory short- and mid-term outcomes for the preservation of the LSA in patients with TBAD. ISMF-TEVAR appears to offer better clinical outcomes with higher patency and lower reintervention rates. However, ISMF-TEVAR had longer operation times with higher procedure expenses.

CLINICAL RELEVANCE STATEMENT

When LSA revascularization is required during TEVAR, in situ, fenestration, and chimney techniques are all safe and effective methods; in situ, fenestration-TEVAR appears to offer better clinical outcomes, but takes longer and is more complicated.

KEY POINTS

LSA revascularization during TEVAR reduces post-operative complication rates. Both in situ ISMF-TEVAR and chimney-TEVAR are safe and effective techniques for the preservation of the LSA during TEVAR. The chimney technique is associated with a higher incidence of endoleakage and branch occlusion, but ISMF-TEVAR is a more complicated and expensive technique.

Predicting the need for subclavian artery revascularization in thoracic endovascular aortic repair: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aims to investigate the effectiveness of left subclavian artery revascularization compared with non-revascularization in thoracic endovascular aortic repair, and to summarize the current evidence on its indications.

METHODS

A computerized search was conducted across multiple databases, including MEDLINE, SCOPUS, Cochrane Library, and Web of Science, for studies published up to November 2023. Study selection, data abstraction, and quality assessment (using the Newcastle-Ottawa Scale) were independently conducted by two reviewers, with a third author resolving discrepancies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models and publication bias was assessed using funnel plots.

RESULTS

In the 76 included studies, left subclavian artery revascularization was associated with reduced risks of stroke (OR, 0.67; 95% CI, 0.45-0.98; n = 15,331), spinal cord ischemia (OR, 0.75; 95% CI, 0.56-0.99; n = 11,995), and arm ischemia (OR, 0.09; 95% CI, 0.01-0.59; n = 8438). No significant reduction in paraplegia (OR, 0.56; 95% CI, 0.21-1.47; n = 1802) or mortality (OR, 0.77; 95% CI, 0.53-1.12; n = 11,831) was observed. Moreover, the risk of endoleak was comparable in both groups (OR, 1.25; 95% CI, 0.55-2.84; P = .60; n = 793), whereas the risk of reintervention was significantly higher in the revascularization group (OR, 1.98; 95% CI, 1.03-3.83; P = .04; n = 272). Both groups had similar risks of major (OR, 0.45; 95% CI, 0.19-1.09; P = .08; n = 1113), minor (OR, 0.21; 95% CI, 0.01-3.45; P = .27; n = 183), renal (OR, 0.61; 95% CI, 0.12-3.06; P = .55; n = 310), and pulmonary (OR, 0.59; 95% CI, 0.16-2.15; P = .42; n = 8083) complications. The most frequent indications for left subclavian artery revascularization were primary prevention of spinal cord ischemia, augmentation of the landing zone, and primary stroke prevention.

CONCLUSIONS

Left subclavian artery revascularization in thoracic endovascular aortic repair was associated with reduced neurological complications but was not found to impact mortality. The study highlights important indications for revascularization as well as significant predictors of complications, providing a basis for clinical decision-making and future research.

Preclinical Evaluation of a Modular Inner-Branched Stent Graft to Reconstruct the Left Subclavian Artery in Thoracic Endovascular Aortic Repair: Experimental Study in Pigs

PURPOSE

In approximate 40% of thoracic endovascular aortic repair (TEVAR) procedures, the left subclavian artery (LSA) needs to be covered to obtain sufficient proximal sealing zone. To preserve the LSA during the TEVAR for type B aortic dissection (TBAD) adjacent to LSA, our team designed a modular single inner-branched stent graft. This study was performed to evaluate the safety and feasibility of deploying a modular single inner-branched stent graft in a porcine model.

MATERIALS AND METHODS

Modular inner-branched stent grafts were implanted in 14 pigs via right femoral and right carotid arterial access. Computed tomography angiography (CTA) and angiography were performed in all pigs to appraise the morphological characteristics of the stent grafts at the end of follow-up. The pigs were then euthanized, and tissues were collected for gross and histological examination.

RESULTS

The technical success rate was 100% (14/14). One pig suddenly died 5 hours after operation, and 1 pig died after completing the follow-up CTA. During the follow-up period, all surviving pigs showed good mental state, normal diets and activities. Computed tomography angiography examinations showed that all stent grafts were intact without fracture. All bridging covered stents were patent. Angiography showed that the position, shape, and adhesion of the stent grafts were good, and no obvious endoleaks were found. Histological examination showed that the biocompatibility of the stent grafts was good.

CONCLUSIONS

This study's outcomes demonstrate that it is safe and feasible to deploy a modular single inner-branched stent graft in a porcine model.

CLINICAL IMPACT

This device is the first modular device designed to treat TBAD adjacent to LSA in China. This device is a modular two-component system consisting of a thoracic aortic stent graft with a retrograde inner branch and a bridging covered stent. The modular design and the retrograde inner branch are the two important innovations of this device. Theoretically, the device could make it easier and safer for clinicians to treat TBAD adjacent to the LSA.

Endovascular Vertebral Artery Transposition Using Flow Reversal Technique for Left Subclavian Artery Stump Syndrome

BACKGROUND

Cerebellar strokes are a rare complication related to thoracic endovascular aortic repair (TEVAR). This can manifest in an indolent manner or as a neurological catastrophe. Often it is unclear when a surgical intervention would be needed. Patients at risk for this relatively rare complication are not easily identified.

CASE

We describe an endovascular option with flow reversal for left vertebral artery transposition using stent grafts for relocating arterial inflow and excluding a floating thrombus at the proximal subclavian artery (SCA) related to a previous TEVAR.

CONCLUSIONS

Ligation of the subclavian artery proximal to the vertebral artery should be considered when performing a carotid subclavian bypass for elective TEVAR. This case details a unique, less invasive approach for vertebral artery transposition and thrombus exclusion in a high-risk patient with previous neck dissection.

Left Subclavian Artery Revascularization for Delayed Paralysis after Thoracic Endovascular Aortic Repair

Spinal cord ischemia (SCI) is a devastating complication following thoracic endovascular aortic repair (TEVAR). A man with a ruptured thoracic aortic aneurysm (TAA) was transferred to our hospital. Emergency TEVAR, with left subclavian artery (LSA) coverage, was performed for the ruptured TAA. On postoperative day two, the patient had incomplete paralysis in his legs, presumably caused by SCI. We performed LSA revascularization (LSAR) to provide blood supply to the spinal cord; his paralysis improved and almost resolved after surgery. To our knowledge, this is the first report on LSAR's efficacy for delayed paraplegia due to SCI.

Fenestrated Endovascular Repair of Zones 1 and 2 Aortic Arch Pathologies

BACKGROUND

Surgical management of aortic arch pathologies is complex, and endovascular developments have now enabled total or hybrid endovascular aortic arch repair. We present our early experience with fenestrated aortic arch repairs in Ishimaru zones 1 and 2 pathologies.

METHODS

In a single tertiary institution, all consecutive endovascular aortic arch repairs were reviewed. A preoperative computed tomography aortogram was performed to assess anatomic suitability, which we defined as having a proximal sealing zone with a maximum diameter of 38 mm and minimum length of 20 mm, absence of significant aortic tortuosity, and suitable sealing zones in target vessels.

RESULTS

From September 2015 to February 2018, 5 cases of fenestrated aortic arch endovascular repairs were performed. There were 3 male patients. The patients were between 57 and 83 years old, all of whom were American Society of Anesthesiologists (ASA) class II or III. Indications for surgery included aortic arch aneurysms (n = 3), a symptomatic aortic dissection, and a left subclavian artery aneurysm. Three patients had a scallop to the innominate artery, and one patient had a scallop to the left common carotid artery. Fenestrations were made to 3 left common carotid arteries and 3 left subclavian arteries. In 2 patients, a left carotid-subclavian bypass was performed, and the left subclavian artery origin occluded with a vascular plug. Technical success was 100%. One patient developed a right occipital infarct and acute myocardial infarction. The mean duration of surgery was 164 min, and the mean length of stay was 4.2 days. The mean follow-up period was 14.4 months.

CONCLUSIONS

The use of fenestrated grafts in the aortic arch is a feasible treatment option. However, certain limitations still exist, and preoperative planning is important in ensuring clinical success. Although this procedure appears feasible in the short term, long-term results and durability remain to be seen.

Management of the left subclavian artery during TEVAR - complications and mid-term follow-up

BACKGROUND

Numerous conditions that affect the boundary between the aortic arch and descending aorta are treated with thoracic endovascular aortic repair (TEVAR). In 40 % of cases, coverage of the left subclavian artery (LSA) cannot be prevented. Subsequently, neurological complications such as stroke or ischemia of the left upper extremity may develop. However, the actual risk of these complications is subject to considerable controversy. The optimal treatment approach, specifically the question whether primary revascularization of the LSA should be performed in all cases, is unclear.

PATIENTS AND METHODS

The present retrospective study analyzed the short- and mid-term results of patients treated with TEVAR with complete coverage of the LSA. The postoperative protocol consisted of clinical and noninvasive examinations as well as morphological imaging. Survival, complication, and reintervention rates were recorded.

RESULTS

A total of 40 patients, undergoing TEVAR with complete coverage of the LSA between January 2010 and December 2014 were analyzed retrospectively. The 30-day survival rate was 95 %, the survival one year after performed TEVAR was 67.5 %. The average follow-up was 1.5 years. After TEVAR procedure with complete coverage of the LSA, only one patient (2.5 %) developed critical ischemia of the left arm immediately after aortic stent implantation, requiring revascularization by transposition of the LSA. Anterior spinal artery syndrome occurred in another patient (2.5 %) immediately following TEVAR. During follow-up examinations, all patients showed a compensated arterial arm status. None of the patients developed new neurological deficits during the follow-up period.

CONCLUSIONS

The study shows that performing TEVAR without primary revascularization of the LSA was justifiable in our cohort. An important risk factor of developing cerebral ischemia seems to be insufficient collateralization through the circle of Willis.

Spinal cord injury after thoracic endovascular aortic aneurysm repair

PURPOSE

Thoracic endovascular aortic aneurysm repair (TEVAR) has become a mainstay of therapy for aneurysms and other disorders of the thoracic aorta. The purpose of this narrative review article is to summarize the current literature on the risk factors for and pathophysiology of spinal cord injury (SCI) following TEVAR, and to discuss various intraoperative monitoring and treatment strategies.

SOURCE

The articles considered in this review were identified through PubMed using the following search terms: thoracic aortic aneurysm, TEVAR, paralysis+TEVAR, risk factors+TEVAR, spinal cord ischemia+TEVAR, neuromonitoring+thoracic aortic aneurysm, spinal drain, cerebrospinal fluid drainage, treatment of spinal cord ischemia.

PRINCIPAL FINDINGS

Spinal cord injury continues to be a challenging complication after TEVAR. Its incidence after TEVAR is not significantly reduced when compared with open thoracoabdominal aortic aneurysm repair. Nevertheless, compared with open procedures, delayed paralysis/paresis is the predominant presentation of SCI after TEVAR. The pathophysiology of SCI is complex and not fully understood, though the evolving concept of the importance of the spinal cord's collateral blood supply network and its imbalance after TEVAR is emerging as a leading factor in the development of SCI. Cerebrospinal fluid drainage, optimal blood pressure management, and newer surgical techniques are important components of the most up-to-date strategies for spinal cord protection.

CONCLUSION

Further experimental and clinical research is needed to aid in the discovery of novel neuroprotective strategies for the protection and treatment of SCI following TEVAR.

Subclavian stump syndrome causing a posterior circulation stroke after thoracic endovascular aneurysm repair (TEVAR) with adjunctive carotid to subclavian bypass and endovascular embolization of the left subclavian artery

BACKGROUND

Endovascular repair of thoracic aortic pathology has become increasingly common over the last decade. We highlight the case of an intentionally occluded left subclavian artery stump acting as a source of emboli after thoracic endovascular aneurysm repair (TEVAR) for type B dissection.

METHODS

A 68-year-old man underwent TEVAR of a type B thoracic aortic dissection. A carotid subclavian bypass was performed, and an AMPLATZER™ endovascular plug (to occlude the left subclavian artery origin) was used to create an adequate proximal landing zone.

RESULTS

The patient presented with a posterior circulation stroke 2 years later, which was thought to be due to emboli originating from the occluded subclavian artery stump.

CONCLUSIONS

Consideration should be given to ligating the subclavian artery immediately proximal to the vertebral artery origin when performing adjunctive carotid subclavian bypass during TEVAR. If this is not done, surveillance computed tomography scans should monitor for the development of propagating thrombus in the subclavian stump.

Hybrid arch debranching and proximal endograft extension to repair a type I endoleak after endovascular thoracic aneurysm repair

Endovascular repair of complex aortic disease has emerged over the past decade as an alternative to traditional open repair, especially for patients with significant medical comorbidities and/or anatomic challenges, such as reoperative fields. However, the possibility of graft migration and endoleak mandates long-term follow-up of these grafts. We present a patient who underwent hybrid repair after stent graft migration and proximal type I endoleak after thoracic endovascular aneurysm repair. This approach allowed us to avoid extensive surgery that would also necessitate circulatory arrest.

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.