Treatment of proximal vertebral artery stenosis. Vertebral to subclavian transposition

Minimally Invasive Surgical Repair of Vertebral Artery Ostium Stenosis in Patients with Ischemic Stroke: A Single-Center Case Series

BACKGROUND

Ischemic stroke is the second leading cause of death in North Macedonia. Posterior circulation disease, caused by vertebral artery (VA) ostium (VAo) stenosis, is a common cause of ischemic stroke. We established a treatment approach using surgical revascularization of posterior circulation disease. In the present observational study, we assessed the outcome after surgical revascularization of the posterior circulation ischemia caused by VAo stenosis.

METHODS

A retrospective analysis of 20 consecutive patients who had undergone surgery from January 2017 to December 2019. The VA was accessed through a 3-cm incision in the upper medial clavicle. The corrective procedures consisted of resection and anastomosis (15 of 20), VA to subclavian artery transposition (16 of 20), endarterectomy (10 of 20), vein graft interposition techniques (4 of 20), and vein graft bypass (1 of 20).

RESULTS

The cohort included 9 acute cases. The mean patient age was 66.5 years (range 46-77). Of the 20 patients, 8 were women and 12 were men. Left-sided VA pathology was present in 75% of the cases. We observed rapid clinical improvement in 19 patients (95%). The total study period was 321 patient-months, with a median follow-up of 18 months (interquartile range, 5-24 months). One patient had died of an unknown cause after 12 months. During the follow-up period, 15 patients (75%) had reported permanent clinical improvement with no significant relapse of symptoms.

CONCLUSIONS

Minimally invasive surgical revascularization of the posterior brain circulation is a clinically effective therapeutic approach to manage ischemia caused by VAo stenosis. It can be performed safely, promote long-lasting symptom relief, and prevent recurrent strokes.

[Comparative analysis of results of revascularization of the first segment of vertebral arteries]

Analysed herein is efficacy of various operations on the first segment of the vertebral artery (VA) during treatment of patients with vertebrobasilar insufficiency (VBI). The study enrolled a total of 194 patients with the clinical pattern of VBI induced by an atherosclerotic lesion of the first segment of the VA (stenosis >70%). All patients prior to admission had been receiving a course of medicamentous therapy under neurologist's supervision for more than 6 months with no significant effect. The patients were divided into two groups: Group A included 129 (66.5%) patients with VA tortuosity, subjected to 'open' operations, Group B was composed of 65 (33.5%) patients without VA tortuosity, subjected to stenting of the first segment of the VA. The main criteria of assessing the results were patency of the reconstructed zone and clinical improvement after surgery. In 189 (97.4%) patients we managed to attain stable clinical improvement which persisted after 1 year in 177 (91.2%) patients and after 3 years in 156 (80.2%). In the group of stenting, excellent immediate results were obtained - 100% technical and clinical success. However, in the remote period, the outcomes of 'open' operations turned out to be better as compared with those of stenting. Thus, 3-year clinical efficacy of 'open' and stenting operations amounted to 79.8% and 73.8%, respectively (p>0.05). After 'open' operations there was a significantly lower rate of restenosis of the reconstruction zone (1.6%) than after stenting - 15.4% (p<0.05). However, after 'open' operations the frequency of thrombosis of the reconstructed zone was higher than after stenting - 5.5 vs 1.5% (p>0.05). The incidence of stroke after open operations and after stenting amounted to 2.3 and 3.1%, respectively (p>0.05). Comparative assessment of relapse-free survival after all analysed methods of operations and interventions showed that the best techniques in the long-term perspective turned out to be 'open' operations, and amongst them the operation of transposition of the VA to the common carotid artery (median - 13 years) and the operation of reimplantation of the VA into its ostium (median not achieved in follow up observations for more than 18 years).

Hybrid Technique for the Treatment of Refractory Vertebrobasilar Insufficiencies

BACKGROUND

Tortuous or occluded vertebral arteries (VAs) can make the endovascular treatment of vertebrobasilar insufficiency impractical. Bypass surgery is an option, but a craniotomy of the posterior fossa is complicated when physiologic vessels must be abandoned. We report 3 cases of refractory vertebrobasilar insufficiency with different presentations requiring problematic approaches in which the patients were treated by different hybrid strategies.

CASE DESCRIPTION

Patient 1 had severe stenosis of right VA ostium with right V1 segment tortuosity and was treated by right VA ostium transposition during which the proximal subclavian artery was blocked by a balloon guide catheter. Patient 2 had severe stenosis of the basilar artery and bilateral VA tortuosity. The V1 segment was exposed and cut open so that an available approach for endovascular procedures was created. Patient 3 had bilateral VA occlusion. After exposure of the left V1 segment, recanalization of the left VA was performed by an interventional radiologist and surgeon working together. All patients had improved hemodynamics and symptoms alleviated without major complications.

CONCLUSIONS

For refractory vertebrobasilar insufficiencies, hybrid operations that combine surgical manipulation of the V1 segment and endovascular techniques can be safe and effective.

Vertebral Artery Origin Stents Revisited

BACKGROUND

Vertebral origin angioplasty and stenting (VOAS) with bare metal stents is associated with a high rate of in-stent restenosis (ISR).

OBJECTIVE

We evaluated the rate of ISR after VOAS with drug-eluting stents.

METHODS

Twenty patients (15 men, 5 women; age range, 36–88 years; mean, 63.7 years) were treated for VOAS with a paclitaxel-eluting stent (Taxus Express2, Boston Scientific, Natick, Massachusetts). Stenosis at follow-up was quantified as insignificant (0%–24%), mild (25%–49%), moderate (50%–74%), and severe (75%–100%). ISR was defined using a binary criteria of &gt; 50% stenosis at follow-up angiography.

RESULTS

All procedures were technically successful with no periprocedural complications. Follow-up angiography (range, 4–48 months; mean, 14.7 months) showed insignificant stenosis in 9 patients, mild in 6, moderate in 4, and severe in 1. In 1 patient with “moderate” stenosis, the stent migrated distally; therefore, the lesion restenosis was not within the stent. Thus, 4 of 19 patients (21%) exhibited binary moderate or severe ISR, and 5 of 20 showed restenosis at the lesion (25%). The patient with severe stenosis developed stent thrombosis &gt; 3 years after VOAS.

CONCLUSION

VOAS with drug-eluting stents was associated with a low incidence of periprocedural complications. Although the rate of restenosis was half that seen with the use of bare metallic stents, 21% of patients still developed moderate or severe ISR. These patients may require ≥ 1 revascularization procedures. The risk of delayed stent thrombosis may necessitate lifelong dual antiplatelet medications.

Clinical and angiographic long-term outcomes of vertebral artery–subclavian artery transposition to treat symptomatic stenosis of vertebral artery origin

Object

Although angioplasty and stent placement for vertebral artery (VA)–origin stenosis have been performed using endovascular techniques, a high likelihood of restenosis has been observed in the long term. Therefore, the authors assessed the long-term clinical and angiographic outcomes in patients after VA–subclavian artery (SA) transposition.

Methods

Thirty-six patients (31 men, 5 women; mean age 64.3 years, range 46–76 years) underwent clinical evaluation (modified Rankin Scale [mRS]) and cervical angiographic evaluation preoperatively and within 1 month of and 6 months after VA-SA transposition undertaken to treat symptomatic stenosis of VA origin.

Results

Postoperative neurological deficits due to intraoperative brain ischemia did not occur, and MR imaging demonstrated no new postoperative ischemic lesions in any of the patients. One patient died of acute myocardial infarction 2 months after surgery and another developed a left thalamic hemorrhage (mRS score of 5) at 42 months postsurgery. None of the remaining 34 patients experienced further ischemic events, and the mRS score in all of these patients remained unchanged during a mean follow-up period of 54 months. The degree of VA-origin stenosis (preoperative mean 84%) was reduced to ≤ 30% after surgery (mean 2%). Long-term follow-up angiography in 29 patients (81%) revealed the absence of restenosis, defined as > 50% luminal narrowing, in all of them.

Conclusions

The clinical and angiographic long-term outcomes demonstrated here suggest that VA-SA transposition will be useful in patients with symptomatic stenosis of VA origin.

A case of intimal hyperplasia induced by stenting for vertebral artery origin stenosis: assessed on intravascular ultrasound

We report a case of proximal vertebral artery restenosis following stent placement. Intravascular ultrasound study helped delineate its characteristics. A 69-year-old man was admitted because of dysarthria and dysphagia. Angiography revealed hypoplasia of left vertebral artery (VA) and remarkable stenosis of the proximal right VA with inadequate collateral flow from the anterior circulation. Balloon angioplasty and stent placement at the VA was performed to an excellent angiographic result with recovery of neurological symptoms. His condition deteriorated six months later due to intimal hyperplasia, which we evaluated by intravascular ultrasound (IVUS). Balloon angioplasty was then performed. Stent placement may induce intimal hyperplasia and IVUS is useful to assess the lesion.

Reconstructive surgery of the extracranial arteries

The first carotid endarterectomy (CEA) is usually accredited to Eastcott who reported in 1954 the successful incision of a diseased carotid bulb with end-to-end anastomosis of the internal carotid artery (ICA) to the common carotid artery (CCA). During the following years surgeons were quick to adopt and improve the intuitively attractive procedure. But by the early to mid 1980s several leading neurologists began to question the growing number of CEAs performed at that time. Six major CEA trials were then designed which are now completed or nearing completion. Most conclusive data are available from the North American Symptomatic Carotid Endarterectomy Trial (NASCET) for symptomatic carotid disease, and from the Asymptomatic Carotid Atherosclerosis Study (ACAS) for asymptomatic carotid disease. The key result of these studies is that CEA is beneficial to high grade symptomatic and asymptomatic carotid stenosis. While the benefit in symptomatic disease is clear, it may be negligible in asymptomatic patients suffering from other medical conditions, the most important being coronary artery disease. Since the conclusions from the different studies vary significantly, guidelines and recommendations with regard to CEA have been issued by a number of interest groups, so-called consensus conferences. The best known guidelines are published by the American Heart Association (AHA). However, the practice of interest groups to issue guidelines is currently being criticized, the main reason being that interest groups have different ideas and all claim the right to issue guidelines. At present we recommend CEA for symptomatic high-grade stenosis in patients without significant coincident disease. With regard to asymptomatic stenosis we suggest surgery to otherwise healthy patients if the stenosis is very narrow or progressive. Preoperative evaluation has changed over the years. Currently we recommend duplex sonography in combination with intra- and extracranial magnetic resonance angiography (MRA). Concurrent coronary artery disease is a major consideration in the perioperative management, and the use of a specific algorithm is recommended. Surgery is performed under general anaesthesia with intraoperative monitoring such as electroencephalography (EEG) and transcranial Doppler (TCD). A temporary intraluminal shunt is used selectively if after cross-clamping the flow velocity in the middle cerebral artery (MCA) falls to below 30 to 40% of baseline. For years we employed routine barbiturate neuroprotection during cross-clamping. At the present time we use barbiturate selectively, if the flow velocity in the MCA falls to below 30 to 40% of baseline and if the use of a temporary intraluminal shunt is not possible due to difficult anatomic conditions. The reason to abandon systematic barbiturate protection was to accelerate recovery from anaesthesia. Our patients are monitored overnight on the ICU or a surveillance unit. Routine hospitalization after surgery is 5 to 7 days with a control duplex sonography being performed prior to discharge. A number of details with regard to surgical technique and perioperative management are a matter of discussion. Our surgical routine is described here step by step. Such management resulted in 6 major complications among the 402 cases with 4 of cardiopulmonary and 2 of cerebrovascular origin. For the future we can expect the development of percutaneous transluminal techniques competing with standard carotid endarterectomy. At the present time several comparative studies are under way. Irrespective of the technical approach to treat carotid stenosis, several other issues have to be clarified before long. One of the major unresolved items is the timing of treatment after completed stroke. In this regard prospective trials need to be performed. Although numerically not as important as carotid stenosis, vertebral artery (VA) and subclavian artery (SA) stenoses are more and more accepted as indication for surgical