Antiplatelet Treatment in Moyamoya Disease: A Systematic Review.

INTRODUCTION: Moyamoya disease (MMD) is an uncommon cause of stroke. Antiplatelet treatment is commonly prescribed for patients with MMD despite the lack of strong evidence supporting its efficacy. We conducted a systematic review to evaluate evidence of antiplatelet treatment and clinical outcomes among patients with MMD. METHODS: A systematic literature search was performed to identify studies that evaluated the association between antiplatelet treatment and clinical outcomes, including ischemic stroke, hemorrhagic stroke, functional outcome, survival, and bypass patency, in patients with MMD. The following databases were searched: PubMed, Embase, Scopus, and the Cochrane Library, from the inception date to February 2022. RESULTS: Eight studies were included in this systematic review. Six studies evaluated antiplatelet treatment and ischemic stroke. Most studies did not demonstrate a protective effect of antiplatelet treatment against ischemic stroke. Five studies evaluated antiplatelet treatment and hemorrhagic stroke. All of them did not demonstrate an increased risk of hemorrhagic stroke. One study found the benefit of antiplatelet treatment in terms of survival. Regarding the effect of antiplatelet treatment on functional outcome and patency of surgical bypass, the results were inconclusive. CONCLUSION: Current evidence suggests that antiplatelet treatment in patients with MMD did not demonstrate a protective effect against ischemic stroke. However, antiplatelet treatment did not increase the risk of hemorrhagic stroke in patients with MMD. The well-designed randomized controlled trial should be highlighted.

Course of the V3 segment of the vertebral artery relative to the suboccipital triangle as an anatomical marker for a safe far lateral approach: A retrospective clinical study.

Background: The third segment of the vertebral artery (V3) is vulnerable during far lateral and retrosigmoid approaches. Although the suboccipital triangle (SOT) is a useful anatomical landmark, the relationship between V3 and the muscles forming the triangle is not well-described. We aimed to demonstrate the relationship between the V3, surrounding muscles, and SOT in clinical cases. Methods: Operative videos of patients with the vertebral artery (VA) and posterior inferior cerebellar artery (PICA) aneurysms treated with occipital artery-PICA bypass through the far lateral approach were examined. Videos from January 2015 to October 2021 were retrospectively reviewed to determine anatomy of the V3 and the SOT. Results: Fourteen patients were included in this study. The ipsilateral V3 was identified without injury in all patients using the bipolar cutting technique. The lateral 68.2% of the horizontal V3 segment, including the V3 bulge, was covered by the inferomedial part of the superior oblique muscle (SO). The medial 23.9% was covered by the inferolateral part of the rectus capitis posterior major muscle. The inferomedial part of the horizontal V3 segment is located within the SOT. Conclusion: Most of the V3, including the V3 bulge, were located beneath the SO and the inferomedial part of V3 located within the SOT. Elevation of the SO should be performed carefully using the bipolar cutting technique to avoid injury to the V3. To the best of our knowledge, this is the first description of the V3 relative to the SOT in the clinical setting.

Early Exposure of the Dorsal Surface of M1 Segment via the Distal Transsylvian Approach for Clipping of Anteroinferior-Projecting Middle Cerebral Artery Bifurcation Aneurysms.

Background Middle cerebral artery bifurcation (MCAB) aneurysms are common intracranial aneurysms. Anteroinferior-projecting MCAB aneurysms, with M1 segment usually embedded into the deep part of the Sylvian fissure, cause some surgical challenges. The distal transsylvian approach (DTSA) allows M1 exposure from the dorsal surface for proximal control in the early step. Therefore, this study aimed to demonstrate the efficacy and safety of DTSA for clipping anteroinferior-projecting MCAB aneurysms. Methods Among 97 patients with MCA aneurysms, 13 with anteroinferior-projecting MCAB aneurysms who underwent aneurysm clipping via the DTSA between June 2018 and January 2021 were retrospectively evaluated for the aneurysm obliteration rate, surgical complications, and outcomes. Results Ten patients (76.9%) had ruptured MCAB aneurysms and three (23.1%) had incidentally discovered unruptured MCAB aneurysms. Favorable outcome was achieved in 100% of patients with good grade. The complete aneurysm obliteration rate was 100% without intraoperative lenticulostriate artery injury. Twelve (92.3%) patients had early identified distal M1 segment for proximal control, and one (7.7%) patient had premature rupture of aneurysm that achieved favorable outcome at 3 months postoperatively. Difficult M1 exposure and premature rupture occurred in the patient with MCAB located above the Sylvian fissure line. Permanent postoperative neurological deficit was detected in one patient due to severe vasospasm. Conclusion DTSA, which simplify the early exposure of the dorsal surface of distal M1, is safe and effective for clipping anteroinferior-projecting MCAB aneurysms without extensive Sylvian fissure dissection. High-positioned MCAB requires careful dissection of the aneurysm neck with consideration of tentative clipping preparation.

Microsurgical Treatment of Vertebral Artery Dissection: Surgical Strategies and Treatment Outcomes.

BACKGROUND: Vertebral artery dissection (VAD) is a rare cerebrovascular disease that can lead to permanent morbidity or mortality. Open surgery for VAD is challenging; therefore, most cases are managed via endovascular techniques. There are several surgical methods for VAD treatment, including trapping or proximal occlusion with or without bypass; however, the standard treatment protocol is not well established. The aims of this study were to demonstrate surgical strategies, surgical outcomes, and complications of each method and to propose an algorithm to select the appropriate procedure. METHODS: This study included 22 patients with VAD who underwent open surgical treatment between January 2015 and December 2019 and were retrospectively reviewed and evaluated for postoperative outcomes and complications. RESULTS: Proximal occlusion, trapping, occipital artery-posterior inferior cerebellar artery (PICA) bypass with blind-alley formation, and occipital artery-PICA with trapping were performed in 13, 2, 5, and 2 patients. The surgical procedure depended on the type of VAD: pre-PICA, PICA, post-PICA, and non-PICA. All VADs were completely obliterated after surgery. Obliteration occurred immediately for 18 patients (81.8%) and within 1 week for 4 patients (18.2%). There was no postoperative bleeding or PICA infarction. Favorable outcome at 3 months after operation was achieved in 100% for good-grade patients and 86.4% overall. CONCLUSIONS: Open surgery can be a safe and effective treatment of VAD when surgical strategies are carefully selected. Angioarchitecture and the type of VAD influence the selection of the surgical method.

Suprafascial dissection for pterional craniotomy to preserve the frontotemporal branch of the facial nerve with less temporal hollowing.

BACKGROUND: To protect the frontotemporal branch of the facial nerve (FTFN) when performing pterional craniotomy, several reports suggest the subfascial or interfascial dissection technique. However, the reports of postoperative frontalis paralysis and temporal hollowing, which are common complications, were relatively limited. This study reports the incidence of postoperative frontalis paralysis and temporal hollowing after pterional craniotomy using the suprafascial and interfascial techniques. METHODS: Patients who underwent pterional craniotomy, using the suprafascial technique (leaving the muscle cuff and not leaving the muscle cuff) and the interfascial technique, between November 2015 and September 2018 were retrospectively evaluated for postoperative frontalis paralysis and temporal hollowing using Chi-squared/ Fisher exact test. RESULTS: Seventy-two patients underwent pterional craniotomy, using the suprafascial technique in 54 patients (leaving the muscle cuff in 21 patients and not leaving the muscle cuff in 33 patients) and the interfascial technique in 18 patients. Eleven patients (20.4%) in the suprafascial group and 1 patient (5.6%) in the interfascial group developed transient frontalis paralysis (P = 0.272). No permanent frontalis paralysis was observed. Obvious temporal hollowing occurred in 18.2% of patients in the suprafascial group without the muscle cuff, in 64.3% of patients in the suprafascial group with the muscle cuff, and in 72.7% of patients in the interfascial group (P = 0.003). CONCLUSION: The suprafascial dissection technique does not cause permanent injury of the FTFN, and this approach results in a significantly lower incidence of postoperative temporal hollowing than interfascial dissection, especially without leaving a temporalis muscle cuff.

Factors Influencing 1-year Functional Outcome after Surgery in Aneurysmal Subarachnoid Hemorrhage Patients: A Single-center Series.

OBJECTIVE: The objective of the study was to evaluate the outcome and related factors in patients with aneurysmal subarachnoid hemorrhage (aSAH). MATERIALS AND METHODS: Clinical data of 221 patients who were diagnosed with spontaneous SAH due to ruptured intracranial aneurysm and surgically treated at Vajira Hospital between January 2013 and May 2016 were retrospectively reviewed. Patient and aneurysm characteristics, clinical status at presentation, treatment, and status at discharge and 1 year after discharge were recorded. Outcomes 1 year after surgery were assessed using the Glasgow Outcome Scale (GOS). Patients were divided into two groups according to the GOS score: the favorable outcome group (GOS scores 4 and 5) and unfavorable outcome group (GOS scores 1-3). RESULTS: Among the 221 study patients, 158 were classified in the favorable outcome group and 63 in the unfavorable outcome group. Patient age, Hunt and Hess grade, aneurysm size, use of Vitamin C solution irrigation in the subarachnoid space, and GOS score 1 year after surgery significantly differed between the two groups. CONCLUSIONS: Numerous factors analyzed in this study were significantly associated with 1-year outcome in surgically treated aSAH patients, including subarachnoid Vitamin C irrigation. Further study of subarachnoid Vitamin C irrigation is warranted.

Anterior Temporal Approach for Clipping Posterior-Projecting Supraclinoid Carotid Artery Aneurysms: A More Lateral Corridor to Better Visualize the Aneurysm Neck and Related Branches.

BACKGROUND: Direct visualization of the aneurysm neck and its related branches during microsurgical clipping of supraclinoid internal carotid artery (SICA) aneurysms using a standard pterional approach may be difficult, especially when aneurysms are posteriorly projected. We evaluated the efficacy and safety of an anterior temporal approach for clipping posterior-projecting SICA aneurysms. METHODS: Between December 2017 and March 2020, 26 patients with posterior-projecting SICA aneurysms who received microsurgical clipping via an anterior temporal approach were retrospectively reviewed. The percentage of complete aneurysm obliteration, intraoperative visualization, and preservation of related branches were evaluated. RESULTS: Aneurysm locations were the posterior communicating artery (PCoA) (internal carotid artery [ICA]-PCoA) in 22 patients (84.6%), the anterior choroidal artery (AChA) (ICA-AChA) in 3 patients (11.5%), and both locations in 1 patient (3.9%). Complete aneurysm obliteration was achieved in all patients. For ICA-PCoA aneurysms in which the PCoA was preoperatively identified, the artery was intraoperatively identified in all cases and preserved 100% after surgery. For ICA-AChA aneurysms, AChAs were intraoperatively identified and preserved in all cases after surgery. Procedural-related infarction was 8.7% for ICA-PCoA aneurysms and 7.7% for all SICA aneurysms. Transient oculomotor nerve palsy was found in 2 patients (7.7%). No postoperative temporal contusion was detected. A good outcome at 3 months after surgery was achieved in 90% of patients for good clinical-grade subarachnoid hemorrhage and unruptured cases. CONCLUSIONS: The anterior temporal approach is safe and effective for clipping SICA aneurysms with posterior projection, with a high preservation rate of the related branches.

Early Exposure of the Dorsal Surface of M1 Segment via the Distal Transsylvian Approach for Clipping of Anteroinferior-Projecting Middle Cerebral Artery Bifurcation Aneurysms.

BACKGROUND: Middle cerebral artery bifurcation (MCAB) aneurysms are common intracranial aneurysms. Anteroinferior-projecting MCAB aneurysms, with the M1 segment usually embedded into the deep part of the Sylvian fissure, cause some surgical challenges. The distal transsylvian approach (DTSA) allows M1 exposure from the dorsal surface for proximal control in the early step. Therefore, this study aimed to demonstrate the efficacy and safety of DTSA for clipping anteroinferior-projecting MCAB aneurysms. MATERIALS AND METHODS: Among 97 patients with MCA aneurysms, 13 with anteroinferior-projecting MCAB aneurysms who underwent aneurysm clipping via the DTSA between June 2018 and January 2021 were retrospectively evaluated for the aneurysm obliteration rate, surgical complications, and outcomes. RESULTS: Ten patients (76.9%) had ruptured MCAB aneurysms and three (23.1%) had incidentally discovered unruptured MCAB aneurysms. Favorable outcome was achieved in 100% of patients with good grade. The complete aneurysm obliteration rate was 100% without intraoperative lenticulostriate artery injury. Twelve (92.3%) patients had early identified distal M1 segment for proximal control, and one (7.7%) patient had premature rupture of aneurysm that achieved favorable outcome at 3 months postoperatively. Difficult M1 exposure and premature rupture occurred in the patient with MCAB located above the Sylvian fissure line. Permanent postoperative neurological deficit was detected in one patient due to severe vasospasm. CONCLUSIONS: DTSA, which simplify the early exposure of the dorsal surface of distal M1, is safe and effective for clipping anteroinferior-projecting MCAB aneurysms without extensive Sylvian fissure dissection. High-positioned MCAB requires careful dissection of the aneurysm neck with consideration of tentative clipping preparation.

Anterior temporal approach for clipping of ruptured basilar tip aneurysms: Surgical techniques and treatment outcomes.

BACKGROUND: Basilar tip (BT) aneurysms are challenging to treat with microsurgical clipping, especially in subarachnoid hemorrhage cases. The anterior temporal approach is one of the surgical approaches for the treatment of aneurysms in this area. The majority of the previous reports on this approach have described unruptured cases. For the ruptured cases assessed in our study, the authors describe the surgical technique, patient characteristics, and surgical outcomes following the use of this technique. METHODS: Fourteen patients with ruptured BT aneurysms who received aneurysm clipping with an anterior temporal approach between December 2015 and August 2019 were retrospectively evaluated. The surgical techniques are described, an illustrative case is shown. RESULTS: The average patient age was 62.2 years (range: 46-78) for ten women and four men. Nine patients (64.3%) were classified as having a poor grade (World Federation of Neurosurgical Societies Grades 4 and 5) at the first presentation. All of the cases demonstrated complete aneurysm obliteration. Good outcomes (mRS 0 to 2) at 6 months were achieved in 58.3% of the patients and in 77.8% of the patients who had a good Glasgow Coma Score after resuscitation before surgery. Postoperative transient oculomotor nerve palsy and thalamic infarctions were detected in six patients (42.9%) and two patients (14.3%), respectively. CONCLUSION: With appropriate case selection, the anterior temporal approach was effective and safe for the clipping of ruptured BT aneurysms.

Heel Suturing on the Donor Vessel prior to Arteriotomy for End-to-side Cerebrovascular Anastomoses.

Microvascular anastomosis is a common procedure in cerebrovascular surgery. End-to-side anastomoses were the most common procedure for extracranial-to-intracranial bypass. Many techniques were used to reduce clamping time of the recipient vessel. The authors innovated heel suturing on the donor vessel prior to arteriotomy (HSDA) technique from the previously described double sutures on the toe and heel of the donor vessel before arteriotomy technique for end-to-side anastomosis. Forty-three end-to-side anastomoses using the HSDA technique were collected from 32 patients.

Interhemispheric Approach with Early A1 Exposure for Clipping Anterior Communicating Artery Aneurysms: Operative Techniques and Outcomes.

BACKGROUND: The interhemispheric approach (IHA) provides an excellent surgical corridor for clipping anterior communicating artery aneurysms (AcoAAs). However, an important disadvantage of the approach is obtaining proximal control at A1 in the last stage of dissection, especially in anterior or superior projecting AcoAAs and ruptured cases. We describe and evaluate the microsurgical clipping of AcoAAs using the IHA with early A1 exposure. METHODS: This was a retrospective descriptive study in patients with AcoAA who received microsurgical clipping through the IHA with early A1 exposure between April 2016 and May 2019. Aneurysm morphology, projection, completeness of clipping, surgical complications, and outcomes were collected from medical records. RESULTS: Twenty-five patients with AcoAA received microsurgical clipping via the IHA with early A1 exposure. Twenty-three patients (92%) presented with subarachnoid hemorrhage. Intraoperative rupture while dissecting the interhemispheric fissure occurred in 2 cases, for which proximal control via subfrontal route was effectively performed. Of the patients, 100% achieved complete obliteration of their aneurysms. Postoperative anosmia was detected in 22.7%. In ruptured cases, 16 (88.9%) of the good grade patients achieved a good outcome (Glasgow Outcome Scale scores of 4 and 5) at 3 months after the operation. CONCLUSIONS: The IHA with early A1 is safe and effective for clipping AcoAAs.

Blind-Alley Formation and Occipital Artery-Posterior Inferior Cerebellar Artery Bypass for the Treatment of Unclippable Vertebral Artery Aneurysms with Posterior Inferior Cerebellar Artery Involvement.

BACKGROUND AND IMPORTANCE: Unclippable vertebral artery aneurysms (UVAs) are difficult to treat with direct clipping, especially in cases involving the origin of the posterior inferior cerebellar artery (PICA). Bypass with trapping is the common procedure used for these conditions. The authors used the blind-alley formation technique, which is a simpler method than trapping and can avoid some complications. OBJECTIVES: To report 7 cases of UVA with PICA involvement treated with blind-alley formation and occipital artery (OA)-PICA bypass as well as their surgical outcomes and complications and to describe the operative techniques. RESULTS: Seven patients with UVA and PICA involvement underwent OA-PICA bypass and blind-alley formation (occlusions of the PICA origin and vertebral artery proximal to the aneurysm). Vertebral artery dissecting aneurysms and fusiform atherosclerotic vertebral artery aneurysms were detected in 6 patients and 1 patient, respectively. All patients presented with subarachnoid hemorrhage, and 71.4% of them were classified into the poor-grade group. Good bypass patency and complete aneurysm obliteration were achieved in all cases. Six aneurysms (85.7%) were completely obliterated according to computed tomography angiography performed immediately postoperatively. Another aneurysm was 50% and 100% thrombosed immediately and at 7 days after the operation, respectively. Surgical complications were found in 1 patient (14.3%) who had postoperative diparesis with dysphagia. Three patients (42.9%) achieved a Glasgow Outcome Score of 4 or 5 one month after the operation. CONCLUSIONS: Blind-alley formation and OA-PICA bypass are simple, safe, and effective for the treatment of patients with UVA with PICA involvement.

Preoperative Localization of the Carotid Bifurcation for Cervical Carotid Exposure Using the Mastoid-Hyoid Line.

BACKGROUND AND IMPORTANCE: The location of the carotid bifurcation (CB) is highly variable, which makes precise exposure of the cervical carotid artery difficult, especially in transverse incisions. The method for preoperative localization of the CB is not well established. We used the distance from the mastoid-hyoid (M-H) line to the CB, measured preoperatively with computed tomography angiography, to localize the location of the transverse skin incision. We describe and evaluate the accuracy of a method for preoperative localization of the CB for cervical carotid exposure. METHODS: The researchers retrospectively evaluated 16 patients with aneurysms arising from the internal carotid artery (ICA) who had received cervical carotid exposure using the localization method of incision and were retrospectively evaluated from February 2018 to November 2019. The method of measurement and localization of the skin incision are described, and two illustrative cases are demonstrated. RESULTS: Saccular aneurysms of the ophthalmic (C2) segment and communicating (C1) segment of the ICA were found in 8 and 8 patients, respectively. Nine patients had left-sided exposure, and 7 patients had right-sided exposure. The mean distance from the M-H line to the CB was 2.1 cm (range 0.5-3.5 cm). The accuracy of this method was 93.8%. No paralysis of the depressor anguli oris or the depressor labii inferioris was found postoperatively. CONCLUSION: The distance from the M-H line to the CB can be used to estimate transverse skin incisions for cervical carotid exposure.

Contralateral Transcondylar Fossa Approach with Bilateral V3 Segment Exposure for Clipping of Vertebral Artery Aneurysm Which Deviates Across Midline: A Case Report and Review Article.

This article reports a patient with unruptured right vertebral artery aneurysm which deviates across the midline to the left side. The contralateral (left) transcondylar fossa approach with bilateral V3 exposure is used for aneurysm clipping. The literature related to this technique is also reviewed.

Anterior Temporal Approach for Clipping of Upper Basilar Artery Aneurysms: Surgical Techniques and Treatment Outcomes.

BACKGROUND: Upper basilar artery (BA) aneurysms, which consist of basilar tip and BA-superior cerebellar artery aneurysms, are challenging to treat with microsurgical clipping. The anterior temporal approach is one surgical approach used to treat aneurysms in this region. Most previous reports on this approach have consisted of unruptured cases. Assessing mostly ruptured cases in this study, we describe the surgical technique, patient characteristics, and surgical outcomes. METHODS: Twenty-three patients with aneurysms arising from the upper BA who received aneurysm clipping via an anterior temporal approach between December 2015 and January 2019 were retrospectively evaluated. RESULTS: The location of the aneurysms was the basilar tip in 15 patients (65.2%) and the BA-superior cerebellar artery junction in 8 patients (34.8%). Twenty-one patients (91.3%) presented with subarachnoid hemorrhage. Good outcomes (modified Rankin Scale score 0-2) at 3 months were achieved in 55.6% of all patients and in 80% of good-grade patients (World Federation of Neurosurgical Societies grades I-III) and patients with unruptured aneurysms. For patients with subarachnoid hemorrhage, a good outcome was achieved in 75% of good-grade patients. Postoperative transient oculomotor nerve palsy and thalamic infarctions were detected in 7 patients (30.4%) and 2 patients (8.7%), respectively. CONCLUSIONS: With appropriate case selection, the anterior temporal approach was effective and safe for clipping of upper BA aneurysms, especially under subarachnoid hemorrhage conditions.