Superficial Temporal Artery to Anterior Cerebral Artery Hemi-bonnet Bypass Using Radial Artery Graft for Prevention of Complications after Surgical Treatment of Partially Thrombosed Large/Giant Anterior Cerebral Artery Aneurysm

A Unique and Effective Bypass Technique to Treat Partially Thrombosed Giant Distal Anterior Cerebral Artery Aneurysms in Extremely Narrow Surgical Corridors

BACKGROUND

Surgical treatment of large or giant thrombosed anterior cerebral artery (ACA) aneurysms often involves revascularization. Herein, we describe a unique and effective bypass technique to treat partially thrombosed giant distal ACA aneurysms in extremely narrow surgical corridors.

METHODS

A 68-year-old man underwent aneurysm trapping and ACA revascularization for a partially thrombosed giant ACA aneurysm in a surgical corridor that was narrow due to anatomic factors. By combining a side-to-side anastomosis and an end-to-side anastomosis at a single anastomotic site, we successfully redirected blood flow from the left pericallosal artery to the right pericallosal and callosomarginal arteries.

RESULTS

Postoperatively, cerebral angiography showed that the blood flow in the aneurysm had disappeared, and the bypass remained open. The patient's functional disability gradually improved, and he reported consistently positive outcomes at the 6-month postoperative follow-up examination.

CONCLUSIONS

This revascularization technique may represent an effective novel treatment option, particularly when multiple revascularization procedures are required within a narrow surgical field.

The interpositional bypass with a parietal branch of superficial temporal artery graft for symptomatic atherosclerotic anterior cerebral artery stenosis or occlusion

Background

For nonmoyamoya patients with anterior cerebral artery (ACA) stenosis or occlusion, whether direct revascularization of the ACA territory can prevent stroke is still unclear. The objective of this study was to investigate the efficacy and safety of a parietal branch of superficial temporal artery-interposed superficial temporal artery-to-ACA bypass (PISAB) for preventing stroke in patients with symptomatic atherosclerotic ACA stenosis or occlusion (SAASO).

Methods

We retrospectively analyzed the data from patients with SAASO who had undergone PISAB in our center between April 2016 and November 2021. The rates of patency, satisfaction (revascularization grades A and B) of bypass, perioperative complications, recurrence of ischemic stroke, changes in bypass flow, and improvements in cerebral blood perfusion were analyzed.

Results

A total of 19 SAASO patients were involved in this study. Sixteen out of 19 (84.2%) patients were free from any cerebral ischemic events after surgery. Only 3 patients (15.8%) had recurrent stroke postoperatively. Two (10.5%) surgery-related complications occurred, including hyperperfusion syndrome and minor stroke. No skin ischemic complications occurred. The average follow-up period was 50.6 ± 18.3 months. The flow rate of the bypass was significantly increased half a year after surgery (56.2 ± 8.0 mL/min vs. 44.3 ± 5.3 mL/min, p < 0.001). The ratio of ipsilateral/contralateral mean transit time in the superior frontal gyrus was decreased significantly after bypass (1.08 ± 0.07 vs. 1.23 ± 0.05, p < 0.001) and continued to decrease 6 months after surgery (1.05 ± 0.04 vs. 1.08 ± 0.07, p = 0.002). The patency rate of PISAB was 94.7% (18/19) 2 years after surgery. The satisfaction rate of bypass was 89.5% (17/19).

Conclusion

The results of this study indicate that PISAB, as a safe superficial bypass, can effectively reduce the risk of stroke in SAASO patients. More precise conclusions will require randomized control studies.

Ischemic Stroke Revascularization

Extracranial-intracranial (EC-IC) bypass is one of the most fundamental techniques for ischemic cerebrovascular disease (CVD). We describe the standard surgical strategies, advanced techniques, and controversies concerning revascularization of ischemic stroke. The standard surgical strategies and techniques emphasize how to determine surgical indication, which should be decided for symptomatic internal carotid artery or middle cerebral artery (MCA) occlusive disease with misery perfusion detected by quantitative single photon emission computed tomography. Advanced techniques are available for complex situations such as posterior circulation revascularization, Bonnet bypass for common carotid artery obstruction, and various EC-IC bypasses for ischemia in the MCA and/or anterior cerebral artery territories using inter-grafts such as femoral veins and radial arteries, illustrated by our surgical results and experiences. Controversies include endovascular treatment complementary to EC-IC bypass. Finally, we advocate emergent EC-IC bypass for progressive ischemic CVD, particularly for contraindication or unsuccessful treatment after intravenous tissue plasminogen activator administration and/or endovascular thrombolysis. EC-IC bypass surgery can be reliable for ischemic CVD under strict optimal surgical indications using safe and reliable surgical techniques.

Coding cerebral bypasses: a proposed nomenclature to better describe bypass constructs and revascularization techniques

OBJECTIVE

Bypass surgery has evolved into a complex surgical art with a variety of donor arteries, recipient arteries, interpositional grafts, anastomoses, and suturing techniques. Although innovation in contemporary bypasses has increased, the literal descriptions of these new bypasses have not kept pace. The existing nomenclature that joins donor and recipient arteries with a hyphen is simplistic, underinformative, and in need of improvement. This article proposes a nomenclature that systematically incorporates anatomical and technical details with alphanumeric abbreviations and is a clear, concise, and practical "code" for bypass surgery.

METHODS

Detailed descriptions and illustrations of the proposed nomenclature, which consists of abbreviations for donor and recipient arteries, arterial segments, arteriotomies, and sides (left or right), with hyphens and parentheses to denote the arteriotomies joined in the anastomosis and brackets and other symbols for combination bypasses, are presented. The literature was searched for articles describing bypasses, and descriptive nomenclature was categorized as donor and recipient arteries (donor-recipient), donor-recipient with additional details, less detail than donor-recipient, and complete, ambiguous, or descriptive text.

RESULTS

In 483 publications, most bypass descriptions were categorized as donor-recipient (335, 69%), with superficial temporal artery-middle cerebral artery bypass described most frequently (299, 62%). Ninety-seven articles (20%) used donor-recipient descriptions with additional details, 45 (9%) were categorized as ambiguous, and none contained a complete bypass description. The authors found the proposed nomenclature to be easily applicable to the more complex bypasses reported in the literature.

CONCLUSIONS

The authors propose a comprehensive nomenclature based on segmental anatomy and additional anastomotic details that allows bypasses to be coded simply, succinctly, and accurately. This alphanumeric shorthand allows greater precision in describing bypasses and clarifying technical details, which may improve reporting in the literature and thus help to advance the field of bypass surgery.

Single institute experience of bypass surgery for complex anterior cerebral artery aneurysms: paying special attention to the spatial and diameter relationship between the efferent arteries

Single institute experience with bypass surgery of complex ACA aneurysm was retrospectively reviewed over a 6-year period. Eight patients with complex ACA aneurysms were treated with bypass, including five females and three males, with mean age of 34.2 years old. There were three pre-communicating aneurysms, one communicating artery aneurysm, and four post-communicating aneurysms (two in A2 and two in A3). A3-A3 side-to-side in situ bypass was applied in six cases. A3-radial artery-A3 interpositional bypass was used in one case with far apart A3s, and A3-A3 transplantation in the other with unparalleled aligned A3s. Three aneurysms were secured with proximal clipping, one with distal clipping, one with direct clipping, one with isolation, and two with embolization. Aneurysm obliteration was achieved in all cases. Only one in situ bypass from smaller donor artery towards larger recipient artery failed with minor postoperative infarction. Intraoperative bleeding from the site of anastomosis occurred in one case during embolization. All the patients showed complete recovery with normal neurological function during follow-up at out-of-patient clinics. A simplified surgical algorithm for complex ACA aneurysm is established based on the geometrical and spatial relationship between efferent arteries. The reasons of bypass failure and hemorrhagic complication are also discussed.

[Resection of a giant fusiform aneurysm of the pericallosal artery with «hemi-bonnet bypass» procedure (case report and literature review)]

A 30-year-old woman with giant fusiform aneurysm of the azygos anterior cerebral artery is reported. Clipping of the aneurysm followed by modeling of pericallosal artery was performed in 2017. However, further enlargement of the aneurysm has been observed for subsequent 2 years. The patient underwent redo surgery with excision of the aneurysm followed by «hemi-bonnet bypass» procedure (anastomosis between superficial temporal artery and anterior cerebral artery with radial artery as an interposition graft). Literature data on reconstructive surgery in the treatment of complex pericallosal artery aneurysms are reviewed.

Surgical Management of Giant Intracranial Aneurysms: Overall Results of a Large Series

OBJECTIVE

To review and discuss surgical treatment options for giant intracranial aneurysms (GIAs), focusing on indications, technical aspects, and results, along with some illustrative cases.

METHODS

We reviewed the data of 82 consecutive patients surgically managed between January 2000 and December 2019 for treatment of a GIA.

RESULTS

Male sex and hemorrhage at presentation were prevalent. The average follow-up was 81.2 ± 45 months. The anterior circulation was involved in 76.8% of GIAs. If the GIA showed a clear neck, minimal atherosclerosis, or intrasaccular thrombosis, and ≤2 branches arising from the neck, it was reconstructed. This procedure was possible in 78% of cases. The technique also involved temporary clipping, remodeling, and thrombectomy, as well as fragmentation techniques. Angioarchitectural features other than these techniques underwent bypass and aneurysm trapping. Most bypasses were extracranial to intracranial and high flow. Flow capacity, collateral circulation, and availability of the donor vessel mainly affected the choice of the type of bypass. Overall, successful exclusion of the GIA was 91.4%. The need for retreatment and complication rate were 3.6% and 19.5%, respectively. A good overall outcome (modified Rankin Scale score 0-3) was achieved in 84.2% of patients, and mortality was 10%.

CONCLUSIONS

Microneurosurgical techniques still maintain a significant role for most GIAs, with a high durability and acceptable rate of morbidity and mortality. Clip reconstruction is the first-line surgical treatment option, whereas bypass is indicated in cases of planned or unplanned sacrifice of the parent artery to prevent long-term ischemic complications.

Anatomical features of the superficial temporal artery in hemorrhagic moyamoya disease based on CT angiography

The superficial temporal artery (STA) is an important continuation of the external carotid artery. It is divided into the frontal branch and the parietal branch at or above the zygomatic arch. In the present study, a comparative analysis of the STA in patients with and without moyamoya disease (MMD) was performed using CT angiography. Patients admitted to our institution for spontaneous intracranial hemorrhage were potential candidates. In general, 25 cases (50 sides) in the MMD group and 25 cases (50 sides) in the non-MMD group were selected for evaluation. The morphology of the STA when crossing the zygomatic arch, the association between the STA bifurcation and the zygomatic arch, the branching characteristics of the STA, the parameters of the STA bifurcation point, the diameter of the STA and the distance from the origin of the STA to the bifurcation point were selected for analysis. There were no significant differences between the two groups with regard to the association between the STA bifurcation and the zygomatic arch, the diameter of the STA or the distance from the origin of the STA to the bifurcation point. However, the bifurcation point of the STA was closer to the posterior edge of the mandibular condyle in the patients with MMD.

[Use of the 'bonnet' bypass in treating a patient with symptomatic occlusion of the ipsilateral carotid arteries. Clinical observation]

In this article we present the clinical case of 63 y.o. man with chronic occlusion of the right common, internal, and external carotid arteries, and critical stenosis of the left internal carotid artery, with complaints of muscle weakness and decreased sensitivity of the left limbs. The patient underwent a staged brain revascularization, the left carotid endarterectomy was performed at the first stage and followed by bonnet bypass, which consists in anastomosing the contralateral superficial temporal artery with the ipsilateral intracranial artery by autograft interposition. In the postoperative period, the patient's neurological symptoms regressed. This case demonstrates the possibility of using bonnet bypass as an alternative revascularization method in patients with cerebral blood circulation insufficiency.

“BONNET” BYPASS IN BRAIN REVASCULARISATION

The article describes the “bonnet” bypass, the type of extracranial-intracranial bypass. This technique is performed when ipsilateral arteries can’t be used as a donor when cerebral revascularization is required. The literature was analyzed and three main techniques of “bonnet” have been defined. The indications for performing “bonnet” bypass are determined, and the disadvantages are indicated. Alternative methods of revascularization are presented and technical details of graft protection are described. The “bonnet” bypass is a rare and laborious technique of cerebral revascularisation. However, it is an alternative and effective method of treatment to prevent serious ischemic disorders.

Clinical importance of the superficial temporal artery in neurovascular diseases: A PRISMA-compliant systematic review

The superficial temporal artery (STA) plays a very important role in neurovascular diseases and procedures. However, until now, no comprehensive review of the role of STA in neurovascular diseases from a neurosurgical perspective has ever been published. To review research on the clinical importance of STA in neurovascular diseases, a literature search was performed using the PubMed database. Articles were screened for suitability and data relevance. This paper was organized following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. According to the literature, STA is one of the terminal branches of the external carotid artery and can give off scalp, muscle, and transosseous branches. STA-middle cerebral artery (MCA) bypass is very useful for intracranial ischemic diseases, including moyamoya disease, chronic ICA and MCA insufficiency, and even acute ischemic stroke. For intracranial complex aneurysms, STA bypass remains a major option that can serve as flow replacement bypass during aneurysmal trapping or insurance bypass during temporary parent artery occlusion. Occasionally, the STA can also be involved in dural AVFs (DAVFs) via to its transosseous branches. In addition, the STA can be used as an intraoperative angiography path and the path to provide endovascular treatments. Therefore, STA is a very important artery in neurovascular diseases.