Search

Purpose: This study aims to investigate the microsurgical anatomy of the superficial temporal artery (STA), explore the relationship between STA length and lumen diameter, and develop a reliable radiologic method for selecting STA segments for bypass surgery., Methods: This study used 10 cadaveric dissections (20 STAs, both sides) and 20 retrospective radiological examinations (40 STAs, both sides), employing curved multiplanar reformation and flow color lookup table (CLUT) DICOM processing. Measurements included vessel lumen diameters and luminal cross-sectional thicknesses 3 mm proximal to the STA bifurcation, 3 mm distal to the frontal branch, 5 cm distal to the frontal branch, 3 mm distal to the parietal branch, and 5 cm distal to the parietal branch. The distance between the STA bifurcation and the superior zygomatic border (SZB) was also measured. In our analysis, descriptive statistics encompassed mean, standard deviation (SD), standard error, minimum and maximum values, and distributions. Comparative statistics were performed using Student's t-test, with statistical significance set at p < 0.05., Results: There were no statistically significant differences between STA measurements of bifurcation distances (p = 0.88) and lumen diameters (p = 0.46) between cadavers and radiological measures. However, lumen thicknesses were larger in frontal branches than parietal branches at the seventh and eighth centimeter (p = 0.012, p = 0.039). Branches became thinner distally from the zygoma in both cadavers and radiological image measurements., Conclusion: The CLUT DICOM processing radiological measures provided the high-precision required to enable pre-surgical vessel selection for extracranial-intracranial bypass. The results show that STA vessel luminal diameters are sufficient (> 1 mm) for bypass surgery in the first 9 cm but gradually decrease after that. Also shown is that the choice of frontal versus parietal branches depends on individual anatomical features; therefore, careful preoperative radiological examination is critical., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: Cerebral bypass procedures are complex and require substantial experience and skills and thorough preoperative planning. Cerebrovascular surgeons face increasingly complex bypass cases because most routine cases are managed by endovascular means, and because increasing numbers of patients have complex medical problems that affect available and suitable bypass conduit options. We report the cases of several patients undergoing cerebral bypass with limited bypass conduit alternatives, in whom there were unexpected intraoperative difficulties requiring complex solutions., Methods: The neurological surgery department database was reviewed to identify patients who had undergone cerebral bypass procedures during a 13-year period in whom there were limited available bypass conduits, and in whom unexpected intraoperative difficulties were encountered during cerebral bypass., Results: Patient outcomes and graft patency were evaluated for 13 patients including 6 with ischemia, 3 with giant aneurysms, 2 with mycotic aneurysms, 1 with dissecting aneurysm, and 1 with gunshot-induced pseudoaneurysm. Median duration of follow-up was 43 months. In 12 of 13 patients, bypass graft/grafts were patent on the last computed tomography angiogram. In 1 patient, a prophylactic bypass procedure, the graft was not filling, probably because of lack of demand. Two patients died during follow-up of unrelated causes., Conclusions: Cerebrovascular surgeons should be versatile in dealing with patients with complex bypass. When there are limited available conduit options, we find that collaboration with other surgical specialties (e.g., plastics and vascular) is helpful. In patients in whom extreme intraoperative difficulties are expected, thorough preoperative planning with multiple backup plans should be exercised, as described in this report., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: Simulation models enable trainees to master microsurgical skills before performing surgeries. Vascular bypass is a critical component of cerebrovascular and many nonneurologic procedures. However, most available bypass training models lack important spatial, tactile, and physiologic aspects of real surgery. Animal and placental models provide true physiology but are expensive. While some models adequately simulate superficial temporal artery-middle cerebral artery bypass, there is no model for side-to-side distal anterior cerebral artery bypass. The objective is to create a realistic and inexpensive training model for this important procedure., Methods: The depth of interhemispheric fissures in cadaver brains was compared with the grapefruit radii. Grapefruits were dissected to simulate the operative field within the deep and narrow interhemispheric fissure. Pericallosal arteries were mimicked with chicken wing vessels or synthetic tubing, with an aquarium pump providing closed circulation. Twelve board-certified neurosurgeons who were given bypass training using the grapefruit model were blindly surveyed on model realism and training suitability., Results: Grapefruit depths from pith to central column were comparable with interhemispheric cadaveric fissure depths. Approximate preparation time of grapefruit training models was 5-10 minutes. Surveyed neurosurgeons rated the model a better replicate for cerebral artery bypass (P < 0.02) and more challenging than common training models (P < 0.01). They also rated the grapefruit model as likely to be superior for improving surgical skills before surgery (P < 0.05)., Conclusions: This grapefruit model provides a realistic simulation of side-to-side distal anterior cerebral artery bypass procedure that can be inexpensively and easily implemented in nearly any resource environment., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: To study the microsurgical anatomy of the occipital artery (OA) to determine the optimal segment for use as a conduit in revascularization bypass surgery., Methods: Twelve sides of 6 cadaveric heads that had been injected with colored silicone were exposed using C-shaped postauricular incision. The OA was dissected from its point of origin to the proximal part of the distal segment. For each segment, the diameters and length were measured, and its branches and proximity to the recipient vessel (V3) were examined., Results: The mean diameters were 2.6 mm at the digastric segment, 2.04 mm at the point where it exits the mastoid sulcus, 2.0 mm, at the point just before the last descending muscular branch, and 1.8 mm and 1.5 mm after the branch and attached to the superior nuchal line, respectively. The length of the OA from the point where it exits the mastoid sulcus to the point at which it revealed the last descending muscular branch was 53 mm, and the distance of this section to the V3 was 31 mm., Conclusions: In pathologies necessitating vertebral artery revascularization surgery, it is possible to easily mobilize the OA with a C-shaped postauricular incision in the lateral suboccipital region. To reach a more appropriate segment in terms of diameter, length, and easy anastomosis, V3 sulcal and OA suboccipital segments are more suitable. Thus, if bypass surgery is indicated in cases of vertebrobasilar ischemia, the suboccipital segment of the OA may be an ideal choice and considered as an artery that can be used in "SOS" conditions., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Cerebral revascularization procedures, such as the external carotid-internal carotid bypass, have been used in the clinical management of cerebral ischemic states. Among the most commonly performed bypasses is the superficial temporal artery-middle cerebral artery (STA-MCA) bypass to restore cerebral blood flow. In cases of a foreshortened STA donor vessel, a radial artery (RA) graft is often used as an interposition graft between the STA and MCA. However, addressing the vessel size mismatch between the radial artery and donor can be problematic and challenging. We present the case of an 80-year-old male presenting with positional-onset expressive aphasia and right-sided hemiparesis. Computed tomography perfusion demonstrated a diffusion-perfusion mismatch in a left MCA distribution. Angiography showed a complete left internal cerebral artery occlusion and poor distal filling of the STA. We performed an external carotid artery-to-internal carotid artery bypass through interposing an RA graft to the STA proximally with an end-to-end anastomosis and to the MCA distally using an end-to-side anastomosis. The mismatch between 2 bypass vessel sizes was corrected by removing a small piece from the RA graft at 1 margin and suturing it to itself to reduce the size of the RA vessel diameter opening on the side used to sew to the STA. The patient did well clinically with improved right-sided strength, a patent graft, and no postoperative complications. Addressing vessel mismatch when using RA interposition grafts for bypass is challenging. Various operative approaches to address mismatch should be individualized on the basis of the particular vascular anatomy and needs of the case. Nevertheless, our method of cutting and suturing 1 side of the RA graft into a semiblind end to match donor vessel diameter may be of use to cerebrovascular surgeons in select cases., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Intracranial pseudoaneurysms (IP) represent about 1% of all patients presenting with an intracranial aneurysm. In true intracranial aneurysms, the intima, internal elastic lamina, and media are disrupted, but the adventitia is intact. In pseudoaneurysms, there is disruption of all three layers of the arterial wall, thus resulting in higher rates of re-hemorrhage and thrombus formation. Patients with IP commonly present with subarachnoid hemorrhage or thromboembolic complications. Until now, no specific guidelines have been established for the ideal treatment of pseudoaneurysms. Although IP have higher rates of morbidity and mortality compared to true intracranial aneurysms, surgical treatment can prevent catastrophic hemorrhagic and thrombotic complications. Despite recent advances in endovascular techniques that allow safe approaches to complicated intracranial vascular pathologies, vascular trapping and bypass remains the definitive and safe treatment for IP. Based on our experience and related literature, we consider the latter treatment in experienced hands as an effective and decisive treatment modality to prevent the devastating complications of IP. In this article, we discuss the surgical management of iatrogenic intracranial internal carotid artery pseudoaneurysms by trapping, and extracranial-intracranial bypass through a case illustration in which the technique is demonstrated via a video presentation.

The natural history of Moyamoya disease (MD) is variable. Moyamoya disease in children mostly presents with progressive ischemic complications and in adulthood it tends to present with hemorrhage. Surgical strategies depend on augmenting cerebral blood flow to the anterior cerebral circulation. Revascularization is the mainstay treatment for MD. We introduce a 31 year old female with a history of MD and leftsided revascularization as a child, who presented with headache, confusion, and worsening left sided weakness. Cranial computed tomography (CT) showed a right sided putaminal hemorrhage. Cerebral angiogram with selective external runs revealed MD, hypoplastic parietal branch of the superficial temporal artery (STA) on the right side and previous revascularization on the left side. Thus, our decision was made to perform a bypass with the frontal branch of the STA to an M3-M4 segment of the middle cerebral artery and an encephaloduroarteriomyosynangiosis with the parietal branch of the STA. The patient's postoperative course was uneventful. Postoperative CT angiogram confirmed patency of bypass. This technique provides immediate revascularization and seems to provide risk reduction for ischemic and hemorrhagic stroke. We review the natural history and surgical treatment of MD along with a case presentation in which surgical technique is demonstrated in video.