Risky Cerebrovascular Anatomic Orientation: Implications for Brain Revascularization

STA-A3 Bypass Using Radial Artery Graft for Progressive Cerebral Infarction of Bilateral ACA Region after STA-MCA Bypass Surgery for Moyamoya Disease

Direct revascularization surgery, such as superficial temporal artery (STA)-middle cerebral artery (MCA) bypass, is effective in preventing ischemia and hemorrhage for moyamoya disease. On the other hand, when ischemia of the anterior cerebral artery (ACA) region progresses after ipsilateral STA-MCA bypass, it is difficult to perform revascularization from the viewpoint of the donor artery. A 55-year-old woman with right hemiparesis was diagnosed with cerebral infarction due to moyamoya disease. Left STA-MCA bypass was performed with no postoperative complications, but memory impairment and decreased motivation were observed 2 months after the operation. Magnetic resonance imaging and angiography revealed new infarction in the bilateral ACA area and deterioration in the signal intensity of bilateral ACAs. Revascularization of the bilateral ACA regions was considered necessary, but the left STA was already used in the previous surgery. Therefore, STA-radial artery (RA)-A3 bypass using RA graft combined with right STA-MCA bypass was performed. STA-A3 bypass using an RA graft may be the optimal treatment for ischemia of the ACA region that progresses after STA-MCA bypass.

One-stage Revascularization to the Ipsilateral Middle Cerebral Artery and Contralateral Anterior Cerebral Artery Territories

BACKGROUND

Patients with multiple intracranial atherosclerotic stenoses often present with haemodynamic instability in two remote regions without a reciprocal vascular network. In this situation, revascularisation to each region may be required.

METHODS

In this report, two patients who had coexisting unilateral middle cerebral artery (MCA) and contralateral anterior cerebral artery (ACA) territory ischemia were treated by using ipsilateral superficial temporal artery (STA)-radial artery graft (RAG)-contralateral A3 bypass and ipsilateral STA-MCA bypass in one stage.

RESULTS

Postoperatively, the bypass conduit was well established and the patients' haemodynamic instability was improved.

CONCLUSION

In patients with severe haemodynamic instability in the remote unilateral MCA and contralateral ACA regions, as in our two cases, ipsilateral STA-MCA and ipsilateral STA-RAG-contralateral A3 bypasses in one stage can be a treatment option.

Revascularization to the ACA: effectiveness and variation of the STA-RAG-A3 bonnet bypass

BACKGROUND

The effectiveness of bypass surgery in patients with atherothrombotic ischemia in the anterior cerebral artery (ACA) domain remains unclear. In this study, three cases with ischemia in the ACA territory underwent revascularization surgery using superficial temporal artery (STA)-radial artery graft (RAG)-A3 (pericallosal artery) bonnet bypass. Herein, we discuss the effectiveness and variations of this approach.

METHODS

Among 182 consecutive patients with atherothrombotic ischemic stroke admitted to the NTT Medical Center, Tokyo, from April 2017 to May 2021, three patients with hemodynamic insufficiency in the extensive ACA territory beyond the recent infarct area were treated using STA-RAG-A3 bonnet bypass.

RESULTS

One patient with bilateral severe cerebral blood flow (CBF) deficiency required additional A3-A3 and STA-middle cerebral artery single bypass in conjunction with STA-RAG-A3 bypass. There were no complications associated with the surgical procedure. The patients' hemodynamic study results and neurocognitive performances improved dramatically after surgery.

CONCLUSION

Our results suggest the efficacy of STA-RAG-A3 bypass for atherothrombotic ACA ischemia. However, because the number of cases was too small to generalize our results, more cases and thorough pre- and postoperative hemodynamic studies are necessary to prove the validity of the approach.

STA-Distal ACA Bypass Using a Contralateral STA Interposition Graft for Symptomatic ACA Stenosis

Intracranial arterial stenosis usually occurs due to atherosclerosis and is considered the most common cause of stroke worldwide. Although the effectiveness of bypass surgery for ischemic stroke is controversial, the superficial temporal artery to the middle cerebral artery bypass for ischemic stroke is a common procedure. In our report, a 50-year-old man presented with sudden-onset left side weakness and dysarthria. An angiogram showed significant stenosis in the junction of the right cavernous-supraclinoid internal carotid artery and right pericallosal artery. Symptoms altered between improvement and deterioration. Magnetic resonance imaging showed a repeated progression of anterior cerebral artery (ACA) infarction despite maximal medical therapy. We performed a STA-ACA bypass with contralateral STA interposition. Postoperative course was uneventful with no further progression of symptoms. Thus, bypass surgery may be considered in patients with symptomatic stenosis or occlusion of the ACA, especially when patients present progressive symptoms despite maximal medical therapy.

STA-ACA bypass using the ipsilateral free STA graft as an interposition graft and A3-A3 anastomosis for treatment of bilateral ACA steno-occlusive ischemia

BACKGROUND

Anterior cerebral artery (ACA)-related ischemia is a rare entity in patients with atherosclerosis. Some surgical treatments are reported to date.

METHOD

We present the modification of intracranial-intracranial and intracranial-extracranial bypasses for symptomatic bilateral ACA steno-occlusive disease. The A3-A3 bypass followed by the superficial temporal artery-ACA bypass using the ipsilateral free superficial temporal artery graft is useful without harvesting of the radial artery.

CONCLUSION

Bilateral ACA steno-occlusive induced ischemia can be treated with tailored bypass procedures.