Subclavian to Carotid Artery Transposition: Medial versus Lateral Approach

Physician-Modified Endovascular Grafts for Zone-2 Thoracic Endovascular Aortic Repair

OBJECTIVE

 This study aims to describe our technique and early experience with physician-modified endovascular grafts (PMEGs) for aortic arch diseases in zone 2. We used a total endovascular technique based on a single fenestrated endograft to preserve left subclavian artery (LSA) patency.

METHODS

 From December 2019 to August 2020, six consecutive patients with a variety of thoracic aortic diseases were treated with handmade fenestrated thoracic aortic grafts: four aortic dissections, one penetrating aortic ulcer, and one intramural hematoma. The planning, endograft modification, surgical technique, and follow-up of the patients were described. We evaluated immediate technical success and after 30 days, the LSA patency, Type-1 endoleak, and postoperative complications.

RESULTS

 Thoracic endovascular aortic repair (TEVAR) was performed for zone 2 in all cases. Immediate technical success, defined as successful alignment of the LSA with a covered stent and no Type-1 endoleak, was achieved in all cases. Patients had a 30-day follow-up computed tomography, which demonstrated LSA patency and no Type-I endoleaks. To date, no strokes, left arm ischemia, paraplegia, or conversions to open surgery have been reported; one patient operated for acute Type B dissection died during the early follow-up.

CONCLUSION

 TEVAR for zone 2 with a PMEG to maintain LSA patency achieved technical success and early durability. It is expected that with longer follow-up and a larger number of cases, these results will be confirmed.

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.

External carotid-to-subclavian artery bypass in stent grafting of thoracic aorta

BACKGROUND

A bypass between the left common carotid artery and the left subclavian artery has been made in some patients undergoing thoracic endovascular aortic repair that covers the orifice of the left subclavian artery. However, complications associated with temporary occlusion of the left common carotid artery are reportedly not uncommon.

METHODS

Between January 2009 and September 2011, left external carotid-to-left subclavian artery bypass was made using a polytetrafluoroethylene graft in 15 patients undergoing a thoracic endovascular aortic repair that covered the orifice of the left subclavian artery. Adverse effects associated with the procedure were assessed, and patency of the bypass graft was determined by contrast-enhanced computed tomography before discharge and at least once during follow-up.

RESULTS

All patients were discharged without any brain complications. All 15 bypass grafts were patent prior to discharge and during the follow-up period. One patient suffered temporary left recurrent laryngeal nerve palsy postoperatively. No other sequelae were associated with left external carotid-to-left subclavian artery bypass.

CONCLUSION

Left external carotid-to-left subclavian artery bypass is a promising procedure in patients undergoing thoracic endovascular aortic repair that covers the orifice of the left subclavian artery.

The Use of Protection Device in Landmark-wire Technique of Symptomatic Subclavian Artery Occlusion with Combined Approach via Trans-femoral vs. Trans-brachial Arteries: Technical note

PURPOSE

Since we reported about a landmark technique to reopen an occluded subclavian artery, we have faced difficulty in using protection devices in the vertebral artery to protect against thromboembolism from the reversed steal phenomenon after angioplasty and stenting. Therefore, we are presenting an optimal solution in using a protection device while recanalizing the occluded subclavian artery.

MATERIALS AND METHODS

Among 21 cases of stenting for subclavian artery steno-occlusion, we applied the landmark technique at the opposite end of an occluded segment in 4 patients and used a protection device in two patients. Because the embolic protection device was placed in the vertebral artery via the brachial artery, optimal angioplasty and stenting via the brachial route were limited. Therefore, angioplasty via the trans-brachial approach was needed to be followed by stenting through a trans-femoral approach. We estimated the safe and optimal steps for placement and retrieval of the protection devices in addition to stenting.

RESULTS

The procedure was safely performed when a stent was introduced via the femoral artery and a protection device was used via the brachial artery. However, in cases when a guidewire wasn't passed via the transfemoral route, simultaneous use of two systems via the brachial route could cause friction of devices or trapping of protection devices in a stent. When a protection device was trapped in a deployed stent, we retrieved the protection device with a 4F angiocatheter by selectively rotating the catheter tip. To avoid such procedural difficulty, we recommend using a transbrachial angioplasty followed by trans-femoral stenting while placing the protection device in the vertebral artery via the trans-brachial route.

CONCLUSION

If a guidewire is not passed through using a trans-femoral approach while performing the landmark technique, changing the stenting route from brachial to the femoral artery can be useful after securing the lumen in the occluded subclavian artery after angioplasty via the brachial artery.

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.

How to manage the left subclavian artery during endovascular stenting for thoracic aortic dissection? An assessment of the evidence

BACKGROUND

Despite the publication of recent guidelines for management of the left subclavian artery (LSA) during endovascular stenting procedures of the thoracic aorta, specific management for those presenting with dissection remains unclear. This systematic review attempts to address this issue.

METHODS

Systematic assessment of the published data on thoracic aorta dissection was performed identifying 46 studies, which incorporated 1,275 patients. Primary outcomes included the prevalence of left arm ischemia, stroke, spinal cord ischemia, endoleak, stent migration, and mortality. Outcomes were compared between patients with and without LSA coverage and revascularization incorporating factors such as the number of stents used, length of aorta covered, urgency of intervention, and type of dissection (acute or chronic). Statistical pooling techniques, χ(2) tests, and Fisher's exact testing were used for group comparisons.

RESULTS

As compared with other outcomes, LSA coverage without revascularization in the presence of aortic dissection is much more likely to be complicated by left arm ischemia (prevalence increased from 0.0% to 4.0% [p = 0.021]), stroke (prevalence increased from 1.4% to 9.0% [p = 0.009]), and endoleak (prevalence increased from 4.0% to 29.3% [p = 0.001]). However, revascularization was not shown to reverse these effects. Longer aortic coverage (≥ 150 mm) was associated with an increased prevalence of spinal cord ischemia (from 1.3% to 12.5% [p = 0.011]) and mortality (from 1.3% to 15.6% [p = 0.003]).

CONCLUSION

In patients undergoing endovascular stenting for thoracic aortic dissection, in cases where LSA coverage is necessary, revascularization should be considered before the procedure to avoid complications such as left arm ischemia, stroke, and endoleak, and where feasible, an appropriate preoperative assessment should be carried out.

Landmark-wire technique of symptomatic subclavian artery occlusion

SUMMARY

The landmark at the opposite end of an occluded segment can be used for probing the occluded subclavian artery to be recanalized. Using this technique in three patients with symptomatic subclavian artery occlusion, we found the landmark-wire technique to be safe and effective for reopening completely occluded subclavian arteries. We also introduced a technique in which a protective device can be safely used throughout the stenting procedure.

Endovascular management versus surgery for proximal subclavian artery lesions

Current management of subclavian artery (SA) lesions is controversial. Subclavian-to-carotid artery transposition (SCT) may be challenging but exhibits unparalleled long-term results. Stent-supported percutaneous transluminal angioplasty (sPTA) is technically easier but not always feasible. Long-term results and comparisons have not been published. We compared both methods performed by vascular surgeons. Data were collected prospectively with retrospective analysis at a tertiary-care center. sPTA was performed through a retrograde transbrachial access using self-expanding nitinol stents. Open surgery was SCT only. Society for Vascular Surgery/International Society of Cardiovascular Surgery reporting standards were applied. Seventy-four patients underwent treatment from January 1995 to August 2007 (median age 62.6 years, 40 female; left-sided pathology 60 [81.1%]; risk factors: hypertension 45 [60.8%], dyslipidemia 47 [63.5%], diabetes 21 [28.4%], smoking 43 [58.1%], SA occlusion 50 [67.6%]). Forty patients (54.1%) underwent primary sPTA (62.5% occlusions) and 34 SCT (73.5% occlusions). The two groups were comparable with regard to risk factors. In 12 patients occlusions could not be recanalized (30%), and in two stents failed within 1 month (both for stenosis). All but one underwent subsequent uneventful SCT. All SCTs were successful. No risk factor could be identified for treatment failure except sPTA (p = 0.002, Fisher's exact test). Median follow-up was 50.1 months with sPTA and 52.6 months with SCT. No procedure failed during follow-up in either group. sPTA can be performed successfully by surgeons. Primary sPTA failed in 48% of occlusions (30% of all sPTAs). Prediction of failure is not possible. According to our experience, we recommend primary sPTA for SA stenosis and surgery for SA occlusions.