Superficial temporal artery to middle cerebral artery (STA-MCA) bypass via retrograde arterial anastomosis in a patient with common carotid artery occlusion: a case report

Long-term Patency of Retrograde Bypass Using a Distal Stump of the Parietal Superficial Temporal Artery for Moyamoya Disease

There have been a number of anastomosis methods of bypass techniques reported for moyamoya disease. However, there are yet no randomized controlled trials conducted on the anastomosis method. Retrograde blood flow of the superficial temporal artery (STA) may be used as one of the donor options. Here, we examined the tolerability of retrograde bypass using a distal stump of the parietal STA (dsPSTA). Anastomosis between the dsPSTA and middle cerebral artery (MCA) was performed for consecutive patients with moyamoya disease whose parietal STA was visualized to be longer than 10 cm using contrast-enhanced computed tomography preoperatively. Retrospectively, we have examined its patency and clinical outcome. Retrograde dsPSTA-MCA bypass was performed in 22 hemispheres of 17 patients. The patency of retrograde dsPSTA-MCA bypass in all 22 anastomoses could be confirmed during follow-up periods (mean: 5.5, range: 2-15 years). No recurrence of ischemic events was observed. The dsPSTA-MCA bypass using retrograde blood flow has been determined as one of the many promising anastomosis methods, and long-term patency was achieved in moyamoya disease.

Side-to-side reverse superficial temporal artery to M4 middle cerebral artery bypass for common carotid artery occlusion with bonnet collaterals: illustrative case

BACKGROUND

The bonnet bypass was initially described for common carotid artery occlusion. Considered a second-generation bypass, it augments intracranial perfusion with contralateral external carotid artery flow through an interposition graft running over the scalp vertex. However, the traditional first-generation low-flow superficial temporal artery (STA)-M4 middle cerebral artery (MCA) bypass may be enhanced by performing a side-to-side (S-S) bypass with an intraluminal suture technique (fourth-generation bypass) to increase perfusion through antegrade and retrograde flow.

OBSERVATIONS

The authors present a reimagined S-S STA-M4 bypass in the case of a patient with symptomatic common carotid occlusion, in which the ipsilateral STA filled in a reverse fashion from the contralateral external carotid branches over the scalp vertex (bonnet collaterals). By performing an S-S anastomosis, the authors were able to improve cerebral perfusion and avoid the multiple anastomosis sites of the bonnet bypass.

LESSONS

The patient had a good recovery with resolution of his preoperative symptoms. Follow-up angiography showed a patent bypass supplying the MCA territory through retrograde flow in the frontal and parietal limbs of the STA, converging at the anastomosis site. In this report, the authors present a new fourth-generation bypass dubbed the “S-S reverse STA-M4 MCA bypass.”

Bypass for flow-augmentation in atherosclerotic carotid occlusion: a review of the literature and career experience

Atherosclerosis of the internal carotid artery and intracranial vessels can compromise cerebral hemodynamics and cause stroke. Cerebral bypass has a half-century history in augmenting or replacing blood flow the brain. Several trials have investigated various applications of cerebral bypass in flow augmentation for atherosclerotic disease. This review discusses the clinical science of cerebrovascular atherosclerosis to provide the context in which cerebral bypass is currently applied. This includes prior clinical trials, ongoing clinical trials, and consensus guidelines, and is complemented by studies in the physiologic science of cerebrovascular flow. The scientific background is supplemented by the description of the technical art of bypass surgery based on a three-decade experience. Successful application of cerebral bypass to augment flow in atherosclerotic cerebrovascular disease requires correct diagnosis of compromised hemodynamic reserve refractory to medical optimization and an appropriate matching of bypass flow with cerebral demand.