Occlusion of the left subclavian artery with stent grafts is safer with protective reconstruction

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.

Actual incidence of cerebral infarction after thoracic endovascular aortic repair: a magnetic resonance imaging study

 

OBJECTIVES

The actual incidence of cerebral infarction (CI), including asymptomatic infarction, owing to thoracic endovascular aortic repair (TEVAR) has not been reported in detail. This study was performed to investigate the incidence of post-TEVAR CI by using diffusion-weighted magnetic resonance imaging (DW-MRI) and to determine the risk factors for both symptomatic and asymptomatic CI.

METHODS

We examined 64 patients undergoing TEVAR at our institute between April 2017 and November 2020. Aortic atheroma was graded from 1 to 5 by preoperative computed tomography. Cerebral DW-MRIs were conducted 2 days after the procedure to diagnose postoperative CI.

RESULTS

A total of 44 new foci were detected by post-interventional cerebral DW-MRI in 22 patients (34.4%). Only one patient developed a symptomatic stroke (1.6%), and TEVAR was successfully completed in all cases. Debranching of the aortic arch and left subclavian artery occlusion with a vascular plug was performed in 19 (29.7%) and 12 (18.8%) patients, respectively. The number of patients with proximal landing zones 0–2 was significantly higher in the CI group than in the non-CI group (68.2% vs 11.9%; P < 0.001). The following risk factors were identified for asymptomatic CI: aortic arch debranching (P < 0.001), left subclavian artery occlusion (P = 0.001) and grade 4/5 aortic arch atheroma (P = 0.048).

CONCLUSIONS

Over one-third of the patients examined by cerebral DW-MRI after TEVAR were diagnosed with CI. High-grade atheroma and TEVAR landing in zone 0–2 were found to be positively associated with asymptomatic CI.

Clinical trial registration

02-014.

Emergent endovascular stent grafting for saccular arch aneurysm complicated by aorto-esophageal fistula

Aneurysms of aortic arch are rare but amenable to endovascular therapy. Arch aneurysm presenting with aorto-esophageal fistula and hematemesis is a feared, but relatively rare complication. The extrapolation of the safety and rapidity of emergent endovascular repair for bleeding arch aneurysms has been infrequently reported. A bovine arch anatomy confers distinct advantages for endovascular therapy often avoiding a preceding debranching surgery. However, its endovascular treatment might be complicated by the nonhealing of fistula and potential risk for mediastinitis. Here, we report a case of a bovine aortic arch cystic aneurysm complicated by bleeding aorto-esophageal fistula, which warranted an emergent endovascular therapy. The prevertebral part of LSCA was plugged to interrupt the retrograde filling and a future endoleak. A nonhealing aorto-mediastinal fistula at follow-up was successfully treated by covered esophageal stenting. This report reiterates the importance of multidisciplinary approach with multispecialty collaboration to such complex spectrum of diseases.

Elephant trunk technique for hybrid aortic arch repair

The original elephant trunk technique was developed by Borst in 1983 for the treatment of aortic arch aneurysms. This technique reduced operative risks, but was associated with cumulative mortality rates of 6.9 % for the first stage and 7.5 % for the second stage. Patients also waited a long time between two major surgical procedures. Only 50.4 % of patients underwent the second-stage surgery, and there was a significant interval mortality rate of 10.7 %. With the advent of stent-graft techniques, two different hybrid elephant trunk techniques were developed. One technique is first-stage elephant trunk graft placement followed by second-stage endovascular completion. The conventional elephant trunk graft provides a good landing zone for the stent-graft, and endovascular completion is a useful alternative to conventional second-stage surgery. This method has few major complications, and a postoperative paraplegia rate of 1.1 %. The other technique is the frozen elephant trunk technique. This technique eliminates the need for subsequent endovascular completion, and is particularly useful for the treatment of acute type A dissection because it can achieve a secure seal. However, it is associated with a higher rate of spinal cord ischemia than other methods such as the original elephant trunk technique. The left subclavian artery (LSA) is often lost when performing a hybrid elephant trunk procedure. Revascularization of the LSA should be performed to prevent arm ischemia and neurological complications such as paraplegia or stroke, although the level of evidence for this recommendation is low.

Progress in management of malperfusion syndrome from type B dissections

OBJECTIVE

Malperfusion syndrome is a known predictor of poor outcomes in acute type B dissection. We describe our experience with revascularization in the acute setting.

METHODS

Patients undergoing intervention for ischemia complicated acute type B dissection between November 1999 and March 2011 were reviewed. Details of presenting condition, surgical intervention, and postoperative course were collected. Descriptive and inferential statistical analyses included survival and freedom from reintervention using Cox proportional hazards models.

RESULTS

A total of 61 patients were identified with malperfusion in at least one territory, including spinal cord 7/61 (12%), mesenteric 37/61 (61%), renal 45/61 (73%), and lower extremity 38/61 (62%). Thoracic stent grafts were placed in all patients, and 41% of patients required adjunctive branch vessel stenting. After intervention, resolution of the ischemia was reported in 57/61 (93%) of patients. The 30-day/in-hospital mortality was 21.3%. The 6-month, 1-year, and 5-year survival was 75% (95% CI, 65%-87%), 71% (95% CI, 61%-84%), and 56% (95% CI, 43%-74%), respectively. The 6-month, 1-year, and 5-year freedom from reintervention was 84% (95% CI, 75%-95%), 76% (95% CI, 65%-90%), and 42% (95% CI, 24%-76%), respectively. Territory of ischemia was not independently associated with mortality, but placement of a stent graft proximal to the subclavian artery was associated with poor outcome hazard ratio 2.91 (95% CI, 1.09-8.11; P = .034).

CONCLUSIONS

Malperfusion in any territory at the time of presentation in patients with type B dissections can be treated with endovascular intervention with acceptable outcomes. Opposed to branch vessel intervention alone, increased aortic intervention with regard to proximal coverage may signify more serious disease is associated with worse outcome.

Selective left subclavian ligation in total aortic arch replacement

BACKGROUND

The left subclavian artery (LSA) is usually difficult to manipulate in total aortic arch replacement procedures if it is displaced by huge false lumens in the ascending aorta or right hemiarch. We summarize our experience of selectively ligating the deeply located LSA in total aortic arch replacement and stented "elephant trunk" implantation procedures for Stanford type A aortic dissection.

METHODS

Data of 29 patients with deep LSA undergoing total arch replacement and stented "elephant trunk" implantation from January 2008 to June 2010 were reviewed. The LSA was ligated because of the difficult exposure (21 males, 8 females, age 19 to 55). Collateral circulation of the circle of Willis and bilateral vertebral arteries were assessed thoroughly by preoperative imaging and intraoperative observations. If collateral circulation was sufficient, LSA was ligated; if insufficient, an additional bypass graft was created from the ascending aorta to the left axillary artery.

RESULTS

Twenty-eight patients survived the operation with 1 early death. Postoperative blood pressures were lower in the left arm than in the right (78±17.3 vs 126±3.7 mm Hg, p<0.01), but oxygen saturation, skin temperature, and strength of the left hand were normal. The surviving patients have been followed for 16.6±9.0 months (6 to 36) and none had symptoms of LSA steal syndrome or arm ischemia.

CONCLUSIONS

Ligation of the LSA after strict evaluation of collateral circulation could be safe for type A dissection patients if the exposure is insufficient, and this method can simplify the operation significantly.

Successful treatment of a ruptured aortic arch aneurysm using a hybrid procedure

Aortic rupture has a high mortality rate and can be considered a medical emergency. The standard treatment for aortic rupture is surgical repair. An aortic stent graft for a ruptured descending aorta is considered an effective alternative treatment. However, an aortic stent graft is difficult when the aortic aneurysm is in the aortic arch due to supra-aortic vessels. We report on a patient with a ruptured aortic arch aneurysm treated with a hybrid procedure, which involved a carotid to carotid bypass operation and an aortic stent graft. A 71-year-old male patient visited our cardiovascular center suffering from hemoptysis. The chest CT and aortography showed a 9 cm sized aortic arch aneurysm 0.5 cm distal to the left subclavian artery and a hemothorax in the left lung. The patient refused to undergo a full open operation. We performed a carotid to carotid bypass in advance, and two pieces of aortic stent grafts were placed across the left carotid artery and left subclavian artery. The follow up CT showed the aortic stent grafts, no endoleaks and no thrombus in the aortic arch aneurysm. The patient was discharged from the hospital without complication.

Scalloped thoracic stent-graft for treatment of aortic arch aneurysms with unfavourable landing zones

Endovascular treatments are limited in cases of thoracic aortic aneurysms extending up or proximal to the origin of the left subclavian artery (LSCA). In such cases, the LSCA is usually either occluded or revascularised. We report our first experience of four patients who underwent thoracic aneursym treatment with new custom-made grafts with a scallop in situ for the LSCA. The graft is tailor made per case, and a re-enforced scallop is positioned proximally allowing for the stent to be deployed beyond the origin of the LSCA; the origin of the LSCA remains patent, thus negating the need for revascularisation of the head and neck vessels on the left. The stent contains markers for identifying the scallop and are located along the midline to ensure correct alignment. All of the patients who underwent this procedure had technical success with flow through the LSCA both immediately after stent deployment and on follow-up imaging. This new stent has further expanded endovascular treatment options for patients with thoracic aneurysms extending up to and beyond the LSCA, which can play a part in improving outcome and decreasing mortality rates because surgery for revascularization will not be needed.