Contemporary Relevancy of Carotid–Subclavian Bypass Defined by an Experience Spanning Five Decades

Subclavian artery revascularization with subclavian-carotid transposition for TEVAR and non-TEVAR patients

BACKGROUND

Subclavian artery revascularization (SAR) has become an increasingly performed technique in patients undergoing thoracic endovascular aortic aneurysm repair (TEVAR), in order to optimize the proximal landing zone, or in patients with significant atherosclerotic diseases. SAR was usually achieved through carotid-subclavian bypass (CSB) which is daunted by graft and patency-related issues, or through subclavian carotid transposition (SCT) which has recently been reconsidered as a potential solution. Nowadays, multiple endovascular strategies including parallel grafts, chimney graft and branch-fenestrated repair, are available in patients unfit for open SAR. However, there is no consensus on the preferable technique in both TEVAR- and non TEVAR-patients. The purpose of this study was to evaluate our experience with SCT in terms of overall postoperative adverse events and mid-term patency rate.

METHODS

We performed a retrospective cohort study, including all patients who underwent SCT between June 2014 and March 2020 at our Division. Preoperative risk factors, symptoms, intraoperative details, postoperative outcomes and follow-up data were collected.

RESULTS

A total of 27 patients were included in this study. Indications for SCT included aortic arch debranching for TEVAR for thoracic aortic aneurysm and type B dissection and symptomatic subclavian steal syndrome (SSS). There were no major perioperative adverse events or major neurological complications; five minor adverse events occurred (18.5%) (3 Horner' Syndrome, 1 hematoma requiring reoperation,1 pneumothorax). Peripheral nerve injuries and lymphatic lesions were not recorded. On a mean follow-up of 21±16 months, SCT patency was confirmed in all patients and no deaths occurred. Comparison of baseline and operative characteristics and intraoperative details between groups of patients with or without adverse events did not found differences.

CONCLUSIONS

SCT should be considered a feasible, effective and safe technique for SAR, with low perioperative complications and optimal mid-term patency. This surgical technique appears to provide a lower risk of neurological events and mortality, particularly in TEVAR patients, reducing the complications caused by the coverage of the left subclavian artery.

[Treatment of atherosclerotic lesion of the first segment of subclavian artery]

Severe subclavian artery lesion is an important medical and social problem worsening the quality of life and leading to dire consequences. Vertebrobasilar insufficiency is the main syndrome of lesion of the first segment of subclavian artery. About 20% of all ischemic strokes occur in vertebrobasilar basin. At present, surgical treatment of asymptomatic patients with severe lesion of the 1st segment of subclavian artery is still debatable. Open surgery is optimal for occlusion of this vascular segment. Carotid-subclavian transposition is a preferable option with favorable in-hospital and long-term results. However, carotid-subclavian bypass is an equivalent alternative in case of difficult transposition following anatomical and topographic features of vascular architectonics. Endovascular treatment is preferable for isolated subclavian artery stenosis and should certainly include stenting.

Subclavian Artery Calcification: A Narrative Review

Subclavian artery calcification (SAC) affects 2% of the population and presents a serious risk of developing into subclavian steal syndrome (SSS). Risk factors for plaque formation of the subclavian artery include diabetes, hypertension, and smoking. While SAC generally presents as asymptomatic, symptoms in severe cases may include numbness, pain at rest, and ischemic gangrene. Patients with severe SSS are at high risk of developing neurological symptoms as a result of vertebrobasilar insufficiency affecting posterior cerebral perfusion. On physical examination, SSS is preliminarily diagnosed from bilateral inter-arm systolic blood pressure discrepancy (>10 mmHg), which can be further confirmed with vascular imaging. Duplex ultrasound (DUS) is a cost-effective and non-invasive baseline technique for visualizing luminal stenosis and quantifying peak systolic velocity (PSV). Computed tomography angiography (CTA) provides high-quality, fast, three-dimensional (3D) imaging at the cost of introducing nephrotoxic contrast agents. Magnetic resonance angiography (MRA) is the safest 3D imaging modality, without the use of X-rays and contrast agents, that is useful in assessing plaque characteristics and degree of stenosis. DUS-assisted digital subtraction angiography (DSA) remains the gold standard for grading the degree of stenosis in the subclavian artery and determining the distance between the puncture site and lesion, which can be carried out in a combined procedure with endovascular management strategies. The fundamental treatment options are surgical and endovascular intervention. Endovascular treatment options include percutaneous transluminal angiography (PTA) for recanalization of the stenosed vessel and permanent balloon stenting to prevent collapse after PTA. Overall, the benefits of endovascular management encompass faster recovery, lower stenosis recurrence rate, and lower incidence of complications, making it the treatment of choice in low-risk patients. Surgical interventions, although more complex, are considered gold-standard treatment options.

One-year outcome of postoperative stroke and nerve injury after supraclavicular revascularization of the left subclavian artery for proximal landing zone extension in thoracic endovascular aortic repair

OBJECTIVE

To assess the outcome of stroke and nerve injury after supraclavicular revascularization of the left subclavian artery for proximal landing zone extension in thoracic endovascular aortic repair (TEVAR).

METHODS

Retrospective analysis of all patients undergoing left-sided carotid-subclavian bypass (CSB) and subclavian-carotid transposition (SCT) with simultaneous or staged TEVAR between January 2010 and June 2019. Endpoints were perioperative cerebrovascular events and nerve injuries, patency and re-intervention due to the debranching, and mortality at 30 days and during follow-up.

RESULTS

Forty-eight patients (median age 66 years, 81 % male) had 25 (52%) CSB and 23 (48%) SCT. TEVAR was performed simultaneously in 39 (81%) patients, eleven (23%) of them in an emergent setting. There were seven (15%) re-interventions within 30 days: three due to local hematoma, one for bypass occlusion, two for stenosis (of which one was not confirmed intraoperatively), and one after initially abandoned SCT with subsequent CSB on the next day. Thirty-day mortality was 2%; one patient died on the first postoperative day after emergency coronary artery bypass surgery and multiorgan failure. Four (8%) patients suffered postoperative strokes; three occurred after simultaneous emergency procedures and none was fatal. There were nine (19%) left neck nerve injuries in eight patients, five patients had SCT and three CSB. During a median follow-up of 37.5 months (IQR 23-83) with a Follow-up Index of 0.77, there were no reinterventions or occlusions, and no graft infections. Primary patency was 90% and primary assisted patency 98% during follow-up. Eight patients died during follow-up, all of them with patent cervical debranching.

CONCLUSION

Supraclavicular LSA revascularization for proximal landing zone extension in TEVAR is safe with an acceptable rate of early re-interventions. There is higher risk for perioperative stroke during concomitant emergency LSA revascularization and TEVAR. Left neck nerve injuries are common complications but resolve completely in vast majority of the cases during first postoperative year. During follow-up, excellent patency could be expected.

Transthoracic aorto-axillary extra-anatomical bypass for difficult subclavian artery revascularization: a multicenter patency study

In situ revascularization of the subclavian artery can be challenging in the context of emergency situations, a large aortic aneurysm with a posteriorly displaced left subclavian artery, a complex redo procedure or in the presence of an aberrant subclavian artery. A transthoracic aorto-axillary extra-anatomical bypass is a low risk alternative to in situ revascularization or carotid to subclavian bypass. We herein describe the surgical steps during a single-stage surgery complex aortic arch surgery. We report a 95.3% graft patency for 77 consecutive transthoracic aorto-axillary extra-anatomical bypass performed to 66 patients at the mean follow-up of 2.9 ± 2.4 years. We encountered 3 early (before 180 days postop) graft failures and no late graft failure. Graft failure had no clinical significance.

Adding Supra-Aortic Trunk Surgical Reconstruction to Carotid Endarterectomy: Implications on Risk of Stroke and Death

BACKGROUND

Additive risks of combining supra-aortic trunk surgical reconstruction (SAT) with carotid endarterectomy (CEA) for associated carotid bifurcation and great vessel disease management are not well defined. This study sought to define risk of combining SAT with CEA.

STUDY DESIGN

Isolated CEA (ICEA) and CEA+SAT (from 2005 to 2015) were identified from NSQIP, excluding nonocclusive indications. CEA+SAT were compared with ICEA as well as a propensity-matched ICEA cohort. Primary outcomes included 30-day stroke, death, and composite (SD). Outcomes were then weighted by symptomatic status. Univariate and logistic regression analyses were performed.

RESULTS

Patients included 79,477 ICEA and 270 CEA+SAT. SAT reconstructions included 19 (7%) aorto-carotid bypasses, 21 (8%) carotid-subclavian transpositions, 85 (31%) carotid-carotid bypasses, and 145 (54%) carotid-subclavian bypasses. There was no difference in 30-day mortality (vs CEA+SAT 1.5% vs ICEA 0.7% p = 0.12). CEA+SAT had higher rates of stroke (3.7% vs 1.6%, p = 0.005) and stroke and death (SD) (4.8% vs 2.1%, p = 0.001). Predictors of SD included CEA+SAT (odds ratio [OR] 5.2, 95% CI 1.03-26.3, p = 0.046) and symptomatic status (OR 1.9, 95% CI 1.1-3.2, p = 0.02). After propensity matching, CEA+SAT continued to have higher rates of stroke (3.4% vs 0.4%, p = 0.01) and SD (4.5% vs 1.5%, p = 0.04), with similar mortality (1.5% vs 1.1%, p = 0.70). No differences were noted in primary endpoints in asymptomatic patients. In symptomatic patients, CEA+SAT carried significantly higher stroke (5.6% vs 2.1%, p = 0.04) and SD risk (7.0% vs 2.8%, p = 0.03).

CONCLUSIONS

CEA+SAT confers increased risk of stroke and SD over ICEA. Symptomatic status and concomitant procedure contribute to this risk. Management should be considered within the context of lesion characteristics, patient longevity, and individual operative risk profile.

Impact of Adding Carotid Endarterectomy to Supra-aortic Trunk Surgical Reconstruction

BACKGROUND

Up to 20% of patients requiring open supra-aortic trunk (SAT) reconstruction have significant carotid artery stenosis. The addition of carotid endarterectomy (CEA) to SAT has been described. Yet, additive risks are not well defined and controversy remains as to whether concomitant CEA increases stroke risk. This study assessed the perioperative effects of adding CEA to SAT.

METHODS

Using the National Surgical Quality Improvement Program (NSQIP), patients who underwent SAT from 2005 to 2015 were evaluated. SAT + CEA were identified. An isolated SAT (ISAT) cohort was created by removing patients who underwent concurrent secondary procedures. Nonocclusive indications were excluded. SAT + CEA were compared with ISAT as well as a propensity-matched ISAT cohort. Primary outcomes were 30-day stroke, death, and composite stroke/death/myocardial infarction (SDM). Univariate and logistic regression analyses were performed.

RESULTS

After review, 1,515 patients were identified: 1,245 ISAT (82%) and 270 SAT + CEA (18%). Most were women (56%), 86% were Caucasian, and 24% were symptomatic. Average age was 65 ± 12 years and SAT + CEA were older (69 vs. 64 years, P < 0.001). CEA + SAT were more likely to be men (53% vs. 42%, P < 0.001), have hypertension (86% vs. 75%, P < 0.001) and diabetes (26% vs. 20%, P = 0.04). SAT procedures included the following: carotid-subclavian bypass (68%), carotid-carotid bypass (16%), aorta-great vessel bypass (9%), and carotid-subclavian transposition (7%). ISAT were more likely to undergo carotid-subclavian bypass than SAT + CEA (71% vs. 54%, P < 0.001). Overall stroke was 2.3%, death 1.4%, and SDM 4.6%. There were no differences in 30-day stroke (ISAT 2.0% vs. SAT + CEA 3.7%, P = 0.09) or mortality (1.4% vs. 1.5%, P = 0.88). SAT + CEA had higher rates of SDM (7% vs. 4%, P = 0.03). On logistic regression, urgency was a predictor of SDM (operating room [OR] 3.6, 95% confidence interval [CI] 1.5-8.4, P = 0.003); addition of CEA was not predictive of stroke (OR 1.4, 95% CI 0.5-4.2, P = 0.52) or SDM (OR 1.5, 95% CI 0.6-3.6, P = 0.40). After propensity matching, there were no longer differences in demographics or primary end points between the 2 cohorts.

CONCLUSIONS

Addition of CEA does not confer increased perioperative stroke or SDM risk over ISAT. Perioperative outcomes appear to be more affected by disseminated disease risk factors than the addition of CEA. In patients undergoing SAT, it is reasonable to consider performing combined CEA in populations with tandem carotid bifurcation disease and appropriate operative risk profile.

Early- and long-term results of thoracic endovascular aortic repair for blunt traumatic thoracic aortic injury: a single-centre experience

OBJECTIVES

Endovascular repair has been proposed as an alternative to classical surgical repair for the management of blunt traumatic thoracic aortic injury. However, the long-term outcomes of endovascular repair and the risks of left subclavian coverage remain unclear.

METHODS

From April 2001 to August 2018, 33 patients with blunt traumatic thoracic aortic injury underwent endovascular repair in our institution. A follow-up computed tomography and a clinical examination were performed before discharge and at 1 month, and yearly or every 2 years thereafter.

RESULTS

The mean age was 45 ± 19 years. The technical success rate was 100%. Complete coverage of the left subclavian artery (LSCA) was performed in 20 patients (60.6%). Among 20 patients with coverage of the LSCA, revascularization was performed in 1 patient. No in-hospital deaths occurred. The clinical follow-up rate was 97%, with a mean period of 7 years and a maximum of 18 years. The survival rates were 100% at 1 year, 95% at 5 years and 88.7% at 10 years after the event. Among the 5 patients (20%) who developed neurological complications, 1 who had undergone implantation of a 200-mm long stent graft and LSCA coverage without revascularization developed paraplegia during the long-term follow-up.

CONCLUSIONS

This study demonstrates that the endovascular treatment of blunt traumatic thoracic aortic injury is a safe and effective therapeutic method over a long-term follow-up period. LSCA coverage and long stent graft placement might be indications for revascularization to prevent spinal cord injury.

Extra-Thoracic Supra-aortic Bypass Surgery Is Safe in Thoracic Endovascular Aortic Repair and Arterial Occlusive Disease Treatment

OBJECTIVE

The safety and feasibility of supra-aortic debranching as part of endovascular aortic surgery or as a treatment option for arterial occlusive disease (AOD) remains controversial. The aim of this study was to assess the clinical outcome of this surgery.

METHODS

This single centre, retrospective study included 107 patients (mean age 69.2 years, 38.4% women) who underwent supra-aortic bypass surgery (carotid-subclavian bypass, carotid-carotid bypass, and carotid-carotid-subclavian bypass) because of thoracic or thoraco-abdominal endovascular aortic repair (57%; 61/107) or as AOD treatment (42.9%; 46/107) between January 2006 and January 2015. Mortality, morbidity with a focus on neurological complications, and patency rate were assessed. Twenty-six of 107 (14.2%) of the debranching patients were treated under emergency conditions because of acute type B dissection or symptomatic aneurysm. Follow up, conducted by imaging interpretation and telephone interviews, continued till March 2017 (mean 42.1, 0-125, months).

RESULTS

The in hospital mortality rate was 10.2% (11/107), all of these cases from the debranching group and related to emergency procedures (p < .0001). One procedure related death of a patient in the debranching group, who had a lethal stroke 72 months post-operatively following bypass occlusion was observed. Early neurological complications were recognised in 10 patients, including two transient cases of Horner syndrome and vocal cord paralysis as well as six cases of phrenic nerve apraxia. Three cases of stenosis and one case of occlusion were successfully treated. In three AOD patients, the graft had to be exchanged because of peri-graft reaction. Primary and secondary patency rates of 96 patients after 36 months were 95% (SE 2.6%) and 98% (SE 1.8%), respectively.

CONCLUSIONS

Extra-thoracic supra-aortic bypass surgery involves low complication rates and high mid-term bypass patency rates. It is a safe and feasible treatment option in the form of debranching in combination with endovascular aortic aneurysm repair and in AOD.

Early outcomes after left subclavian artery revascularisation in association with thoracic endovascular aortic repair

Approximately 40–50% of patients undergoing thoracic endovascular aortic repair require left subclavian artery coverage for adequate proximal landing zone. Many of these patients undergo left subclavian artery revascularisation. However, outcomes data for left subclavian artery revascularisation in the context of thoracic endovascular aortic repair remain limited. In this study, 70 left subclavian artery revascularisation procedures, performed on thoracic endovascular aortic repair patients at a tertiary hospital, were retrospectively reviewed. Particular emphasis was placed on revascularisation-related outcomes during staging interval between revascularisation and thoracic endovascular aortic repair. Forty-six (66%) carotid-subclavian bypass, 17 (24%) carotid-carotid-subclavian bypass and 7 (10%) aorto-inominate-carotid-subclavian bypass procedures were performed. There were no strokes or mortalities following left subclavian artery revascularisation procedures alone. Three (10%) minor complications occurred including a seroma, a haematoma and a temporary neuropraxia. Separation of complications following left subclavian artery revascularisation from those of the associated thoracic endovascular aortic repair can be difficult. Early outcomes data from patients who underwent left subclavian artery revascularisation in isolation indicate that the procedure is safe with low complication rates.

Treatment of subclavian artery stenosis: A case series

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Case presentation of a patient treated with subclavian artery stenting.

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Case presentation of a patient treated with transposition of the left subclavian artery onto the left common carotid artery.

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Case presentation of a patient treated with carotid- subclavian artery bypass with a PTFE graft.

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Case presentation of a patient treated with carotid to axillary bypass.

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Discussion and literature review of methods and indications of treatment of subclavian artery occlusive disease.

Introduction

In this case series, different modalities of treatment for patients with ischaemic symptoms of subclavian stenosis are described, including the different operative strategies that can be adopted in more challenging cases. This is the first case series describing these four management options.

Presentation

Case 1: A seventy-one year-old female presented with acute on chronic ischaemia of her left arm following a fall and developed dry gangrene of her left thumb. This was initially managed with a heparin infusion followed by stenting of the subclavian artery which relieved her symptoms. Case 2: A fifty-nine year-old male presented with chronic ischemia of the left arm secondary to an occlusion of the left subclavian artery. This was managed by transposition of the left subclavian artery onto the left common carotid artery. Case 3: A sixty-four year-old female presented with left subclavian steal syndrome secondary to subclavian artery stenosis. She underwent carotid subclavian artery bypass. Case 4: A fifty-six year-old female presented with acute left upper limb ischaemia secondary to acutely thrombosed subclavian artery on a CT-angiography. She underwent a carotid to axillary bypass.

Discussion and conclusion

This case series demonstrates the treatment options available to vascular surgeons when managing symptomatic subclavian artery disease. Symptomatic subclavian artery occlusive disease should be treated with endovascular stenting and angioplasty as first line management. If it is not successful then open surgery should be considered. Bypassing the carotid to the subclavian or to the axillary artery are both good treatment modalities.

Intentional left subclavian artery coverage during thoracic endovascular aortic repair for traumatic aortic injury

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) is widely used for treatment of traumatic aortic injury (TAI). Stent graft coverage of the left subclavian artery (LSA) may be required in up to 40% of patients. We evaluated the long-term effects of intentional LSA coverage (LSAC) on symptoms and return to normal activity in TAI patients compared with a similarly treated group whose LSA was uncovered (LSAU).

METHODS

Patients were identified from a prospective institutional trauma registry between September 2005 and July 2012. TAI was confirmed using computed tomography angiography. The electronic medical records, angiograms, and computed tomography angiograms were reviewed in a retrospective fashion. In-person or telephone interviews were conducted using the SF-12v2 (Quality Metrics, Lincoln, RI) to assess quality of life. An additional questionnaire was used to assess specific LSA symptoms and the ability to return to normal activities. Data were analyzed by Spearman rank correlation and multiple linear and logistic regression analysis with appropriate transformations using SAS software (SAS Institute, Cary, NC).

RESULTS

During the study period, 82 patients (57 men; mean age 40.5 ± 20 years, mean Injury Severity Score, 34 ± 10.0) underwent TEVAR for treatment of TAI. Among them, LSAC was used in 32 (39.5%) and LSAU in 50. A group of the LSAU patients (n = 22) served as matched controls in the analysis. We found no statistically significant difference in SF-12v2 physical health scores (ρ = -0.08; P = .62) between LSAC and LSAU patients. LSAC patients had slightly better mental health scores (ρ = 0.62; P = .037) than LSAU patients. LSAC patients did not have an increased likelihood of experiencing pain (ρ = -0.0056; P = .97), numbness (ρ = -0.12; P = .45), paresthesia (ρ = -0.11; P = .48), fatigue (ρ = -0.066; P = .69), or cramping (ρ = -0.12; P = .45). We found no difference between groups in the ability to return to activities. The mean follow-up time was 3.35 years. Six LSAC patients (19%) died during the follow-up period of unrelated causes.

CONCLUSIONS

Intentional LSAC during TEVAR for TAI appears safe, without compromising mental or physical health outcomes. Furthermore, LSAC does not increase the long-term risk of upper extremity symptoms or impairment of normal activities.

Routine revascularization is unnecessary in the majority of patients requiring zone II coverage during thoracic endovascular aortic repair: A longitudinal outcomes study using United States Medicare population data

Objective

We aimed to evaluate outcomes of thoracic endovascular aortic repair (TEVAR) with left subclavian artery (LSA) coverage without bypass (TEVAR + SUB) to TEVAR with coverage of the LSA with a bypass at the time of the initial procedure or later at a separate procedure (TEVAR + SUB + BYPASS).

Methods

The Centers for Medicare & Medicaid Services inpatient claims for 2006–2007 were queried using Current Procedural Terminology codes for TEVAR, TEVAR + SUB, TEVAR + SUB + BYPASS or later as a separate procedure.

Results

A total of 2676 patients underwent TEVAR; 869 (32.5%) underwent TEVAR + SUB and 49 (5.6%) TEVAR + SUB + BYPASS. At the time of the initial procedure, TEVAR + SUB + BYPASS was associated with a higher incidence of stroke compared to TEVAR + SUB (12.8% vs. 3.8 %; p = 0.0033). Among TEVAR + SUB, only 1.93% (50 patients) had a subsequent bypass performed during a one-year follow-up. Overall rates of morbidity ( p = 0.004) and mortality ( p = 0.011) trended towards significance in favor of TEVAR + SUB.

Conclusions

TEVAR + SUB were associated with lower rates of mortality and complications. Only a small percentage of TEVAR + SUB required a bypass at one year after procedure. Our data suggest that routine LSA bypass during TEVAR is unnecessary and associated with increase morbidity and mortality.

Further consideration for subclavian revascularization with TEVAR

Management of the left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR) continues to be controversial, despite recent guidelines submitted by the Society for Vascular Surgery recommending routine revascularization of the LSA in most circumstances. Up to one third of patients require coverage of the LSA during TEVAR. The LSA provides extensive circulation to the upper extremity, spinal cord, and brain, consequently, sacrifice of this great vessel might not be physiologically tolerated. Studies supporting routine preoperative revascularization of the LSA note increased rates of spinal cord ischemia, strokes, and upper extremity ischemia when the LSA is sacrificed. Other studies supporting a selective revascularization strategy note no difference in neurologic outcomes and recommend expectant management of upper extremity ischemia. In addition, LSA revascularization has associated complications that are avoided by selective revascularization. The purpose of this article is to review and focus the available data in support of routine versus selective LSA revascularization.