The M2-M1 middle cerebral artery reimplantation bypass with protective superficial temporal artery to middle cerebral artery bypass for giant partially thrombosed middle cerebral artery aneurysm in the hybrid operating suite.

BACKGROUND: Giant middle cerebral artery (MCA) aneurysms are complex and challenging. Revascularization is frequently required in addition to trapping or clip reconstruction, and the MCA reimplantation bypass is ultimately needed when aneurysm excision is planned. METHOD: The operation was conducted in the hybrid operating suite, where an intraoperative cerebral angiography revealed a compromised MCA after multiple attempts of clip reconstruction. Therefore, we decided to perform an M2-M1 reimplantation bypass in conjunction with trapping and aneurysmectomy. CONCLUSION: Reimplantation bypass can be a rescue procedure for revascularization in complex aneurysms. The angioarchitecture varies among individuals; therefore, the optimal bypass technique should be tailored.

Evolution of Intracranial-Intracranial Bypass Surgery: A Bibliometric Analysis.

OBJECTIVE: Modern cerebrovascular bypass surgery uses either extracranial-intracranial (EC-IC) or intracranial-intracranial (IC-IC) approaches. Compared with EC-IC bypasses, IC-IC bypasses allow neurosurgeons to safely address tumors, aneurysms, and other lesions using shorter grafts that are well matched to the size of recipient vessels. Fewer than 100 articles have been published on IC-IC bypasses compared with more than 1000 on EC-IC bypasses. This study examined the increase of interest and innovation in IC-IC bypass. METHODS: PubMed and Web of Science were searched using keywords specific to IC-IC bypass, yielding 717 articles supplemented with 36 reports from other databases and gray literature. The articles were reviewed, and 98 articles were selected for further evaluation. Final articles were categorized as innovations or retrospective studies. Publication metrics were passed through an analytic program to assess statistical measures of growth. RESULTS: The number of publications describing innovations (n = 52) and retrospective studies (n = 46) in IC-IC surgical techniques increased exponentially (R2 = 0.983 and R2 = 0.993, respectively), with both interest and research in the field increasing. The rate of publications in each group also increased. In recent years, increasing numbers of global institutions have researched and published on IC-IC bypasses. CONCLUSIONS: As more work is undertaken on IC-IC bypasses, it is critical for knowledge to be shared through research, collaboration, publication, and early teaching within residency training programs. This field has increased exponentially in the past 2 decades and has yet to reach an inflection point, indicating possible additional interest and growth over time.

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.

Three-Vessel Anastomosis for Direct Bihemispheric Cerebral Revascularization.

BACKGROUND: In rare, complex cerebrovascular pathologies, patients may benefit from simultaneous revascularization of multiple arterial territories. Traditional strategies for these situations include the use of more than 1 interposition graft, multiple microvascular anastomoses, vessel reimplantations, and staged procedures. OBJECTIVE: To improve upon traditional revascularization strategies by describing a novel 3-vessel microvascular anastomosis. This technique combines a side-to-side and an end-to-side anastomoses to facilitate simultaneous direct revascularization of 2 arterial territories in a single procedure, with a single donor vessel. METHODS: We present an illustrative case of moyamoya angiopathy in which a 3-vessel anastomosis was performed in the interhemispheric fissure to simultaneously directly revascularize bilateral anterior cerebral artery (ACA) territories. A detailed step-by-step depiction of the anastomosis technique is provided. In the presented case, 3-vessel anastomosis was combined with a radial artery fascial flow-through free flap, allowing for an additional indirect revascularization. RESULTS: Technical execution of the 3-vessel anastomosis was uncomplicated. The patency of the anastomosis providing direct bilateral ACA territory revascularization was demonstrated intra- and postoperatively. CONCLUSION: With this report, we demonstrate technical feasibility of a novel 3-vessel anastomosis for direct 2 arterial territory revascularization This single-stage approach combines side-to-side and end-to-side techniques and has benefits over traditional revascularization techniques, as it is not deconstructive, requires only a single craniotomy and a single interposition graft, and does not require lengthy recipient artery dissection.

Tailor-Made Branch Reconstruction by Intracranial to Intracranial Bypass During Clipping Surgery for Middle Cerebral Artery Aneurysms.

BACKGROUND: In clipping surgery, it can be advantageous to dissect an adherent artery from the aneurysmal dome to achieve complete clipping. Bypass surgery can be useful to reconstruct an adherent artery when dissection of the artery is technically difficult or risky. We report the effectiveness of tailor-made intracranial (IC)-IC bypass to reconstruct an adherent artery in clipping surgery for middle cerebral artery (MCA) aneurysms. METHODS: A retrospective review of 384 consecutive patients who had presented with MCA aneurysms from 2008 to 2016 had identified 4 patients who had undergone an IC-IC bypass during clipping surgery for reconstruction of an adherent artery. We analyzed the preoperative radiological findings, methods of bypass surgery, surgical complications, and clinical outcomes in the present study. RESULTS: Preoperative angiography showed that the temporal cortical artery coursed along the aneurysmal dome in all cases. These cortical arteries exhibited tight adherence to the aneurysmal body intraoperatively, proving them to be difficult to dissect from the aneurysm. The adherent artery was injured during dissection in 2 cases. These arteries were reconstructed by IC-IC bypass, after which neck clipping was completed. The methods of IC-IC bypass included end-to-end anastomosis in 2 patients, end-to-side anastomosis in 1, and side-to-side anastomosis in 1 patient. Postoperative computed tomography and magnetic resonance imaging revealed neither hemorrhagic nor ischemic complications. The postoperative course was uneventful in all the patients. CONCLUSIONS: During clipping surgery for MCA aneurysms, tailor-made IC-IC bypass is one of the useful options to reconstruct tightly adherent branch arteries, especially when an external carotid artery graft has not been prepared in advance.

The Infrazygomatic Segment of the Superficial Temporal Artery: Anatomy and Technique for Harvesting a Better Interposition Graft.

BACKGROUND: The superficial temporal artery (STA) is underutilized as an interposition graft because current techniques expose and harvest STA above the level of the zygoma. This technique yields a diminutive arterial segment in both length and diameter, which limits its use for extracranial-intracranial bypass. OBJECTIVE: To introduce a safe and efficient technique for harvesting of the infrazygomatic segment of the STA. METHODS: Scalp layers, STA, and the facial nerve were studied in 18 specimens. The length of the STA segment harvested below the superior border of the zygomatic arch was measured. Safety of this technique was assessed by measuring the distance between the facial nerve and the STA. RESULTS: The galea and subgaleal fat pad were the only anatomical planes found between the facial nerve and the STA below the zygomatic arch. A dense subcutaneous band of galea contained the STA and allowed proximal dissection of the artery without exposing the facial nerve. The average length of the artery harvested between the zygomatic arch and the parotid gland was 20 mm. CONCLUSION: Subcutaneous dissection within the galea below the level of the zygomatic arch and preservation of the dense subcutaneous band surrounding the STA avoids transecting the facial nerve branches while providing increased STA exposure. This anatomical knowledge may increase the use of STA as an interposition graft in cerebrovascular bypass procedures and reduce the need to harvest grafts through additional incisions at remote sites.