Frontal sinus reconstruction with overlapping sinus mucosa and vascularized pericranial flap Coverage after modified transbasal bifrontal craniotomy: Novel technique and clinical outcomes.

Background: The modified transbasal bifrontal craniotomy is a variant of the bifrontal craniotomy with a wider surgical corridor than the standard approach. There are several methods for frontal sinus repair in bifrontal craniotomy. This study reports a novel method for frontal sinus repair in the modified transbasal interhemispheric approach by precisely overlapping the frontal sinus mucosa margin (without frontal sinus mucosa exenteration) with packing the frontal sinus with povidone-soaked gel foam and covering it with a vascularized pericranial flap. Methods: In this case series, we retrospectively collected the clinical outcomes regarding cerebrospinal fluid (CSF) leakage, meningitis, and mucocele formation of patients who underwent modified transbasal bifrontal craniotomy at Vara Hospital. Results: From January 2016 to December 2021, 65 patients with anterior skull-base lesions were treated with a modified transbasal interhemispheric approach with frontal sinus repair by overlapping frontal sinus mucosa with gel foam packing and vascularized pericranium flap covering. There was no case of postoperative CSF leakage, meningitis, or mucocele formation during the follow-up period of 19.2 months (min 1, max 73). Conclusions: We demonstrated that the modified transbasal interhemispheric approach with frontal sinus repair using gel foam packing and pericranial flap is effective in preventing postoperative CSF leakage and meningitis.

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.

Microsurgical partial trapping for the treatment of unclippable vertebral artery aneurysms: Experience from 27 patients and review of literature.

BACKGROUND: The efficacy and safety of partial trapping for the treatment of unclippable vertebral artery aneurysms (UVAs) are still questionable. The partial trapping method (proximal or distal occlusion) was used in the treatment of aneurysms to simplify the surgical procedure and avoid postoperative complications. METHODS: This study included 27 patients with UVAs who underwent microsurgical partial trapping between January 2015 and August 2022, and their postoperative outcomes and complications were retrospectively reviewed and evaluated. RESULTS: Ruptured UVAs were detected in 25 (92.6%) patients, and 13 (48.1%) patients had poor-grade status. Fusiform dissection, dissecting, and fusiform aneurysms were observed in 17 (63%), 7 (25.9%), and 3 (11.1%) patients, respectively. By location, preposterior inferior cerebellar artery (PICA), PICA, post- PICA, and non-PICA types were noted in 7 (25.9%), 9 (33.3%), 6 (22.2%), and 5 (18.5%) patients, respectively. Microsurgical partial trapping was performed in all patients (blind-alley formation in 96.3%). Complete aneurysm obliteration was achieved in 26 (96.3%) patients. Immediate complete obliteration was achieved in 21 (77.8%) patients, delayed thrombosis within 7 days in 5 (18.5%), and nearly complete obliteration in 1 (3.7%). No re-bleeding was detected in all patients. Favorable outcomes 3 months after the operation were achieved by 92.9% of the patients in the good-grade group and 85.2% overall. CONCLUSIONS: Microsurgical partial trapping, especially the blind-alley formation technique, was a safe and effective treatment of UVAs with high rates of aneurysm thrombosis. The appropriate sites for clip occlusion were dependent on the angioarchitecture of UVAs.

Far-lateral approach without C1 laminectomy for microsurgical treatment of vertebral artery and proximal posterior inferior cerebellar artery aneurysms: Experience from 48 patients.

Background: In the endovascular era, most of vertebral artery (VA) and posterior inferior cerebellar artery (PICA) aneurysms were mainly treated with endovascular procedures. This study aimed to demonstrate the microsurgical treatment via the far-lateral approach without C1 laminectomy and its clinical outcomes. Methods: Forty-eight patients with VA and proximal PICA aneurysms treated by microsurgery through the far-lateral approach without C1 laminectomy, between January 2016 and June 2021, were retrospectively evaluated. Results: Most patients (87.5%) presented with subarachnoid hemorrhage. Grading at presentation was poor in 41.7%. The rates of VA dissecting aneurysms, saccular aneurysms of the VA-PICA junction, and true PICA saccular aneurysms were 54.2, 18.7, and 14.6%, respectively. All aneurysms were located above the lower margin of the foramen magnum. The far-lateral approach without C1 laminectomy was successfully used in all patients without residual aneurysms. Various surgical strategies were applied depending on the characteristics of the aneurysm. Good outcomes 3 months postoperatively were achieved in 77.1% and 89.3% for the overall and good-grade groups, respectively. Conclusions: Microsurgery is a safe and effective treatment of VA and proximal PICA aneurysms. Moreover, the far-lateral approach without C1 laminectomy was adequate and effective for aneurysms located above the lower border of the foramen magnum.

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.

The Intersection Between the Sternocleidomastoid and Splenius Capitis as the Anatomical Landmark to Facilitate Occipital Artery Harvest: A Retrospective Clinical Study.

BACKGROUND: Occipital artery (OA)-posterior inferior cerebellar artery (PICA) bypass is a challenging procedure and is not frequently performed owing to the difficulty of OA harvest. To facilitate harvest, the intersection between the sternocleidomastoid and splenius capitis (the OA triangle) is used as the anatomical landmark to identify the OA segment that carries the highest risk of damage. This clinical study aimed to demonstrate efficacy and safety of OA harvest using this landmark. METHODS: The study included 18 patients who underwent OA harvest using the OA triangle as a landmark for treatment of vertebral artery and PICA aneurysms. Patients were retrospectively evaluated for safety and patency of OA after harvest and OA-PICA bypass. RESULTS: Of 18 patients with ruptured and unruptured vertebral artery and PICA aneurysms, 13 (72.2%) underwent OA-PICA bypass and 5 (27.8%) did not undergo bypass. The OA was completely harvested without damage in all patients. After harvest, the OA was patent in 17 patients (94.4%) and was occluded in 1 patient owing to vasospasm; this patient then underwent recanalization resulting in good patency of the OA-PICA bypass. The patency rate of the OA-PICA bypass was 100%. CONCLUSIONS: The OA triangle, which is the anatomical landmark of the proximal end of the transitional segment of the OA, facilitated OA harvest using the distal-to-proximal harvest technique with safety and good patency. To the best of our knowledge, this is the first study of OA harvest in clinical cases.

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.

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 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.

Massive Epistaxis from Nontraumatic Cavernous Carotid Aneurysm Treated by High-Flow Bypass and Cervical Internal Carotid Artery Ligation: A Case Report and Review of the Literature.

BACKGROUND: Epistaxis is a rare presentation of the ruptured cavernous carotid aneurysm, especially the nontraumatic type. Both endovascular therapies and open surgeries have a role in the treatment with various outcomes, but the standard procedure is not well established. We report a successful high-flow bypass with cervical internal carotid artery ligation for aneurysm repair and review the related literature. CASE DESCRIPTION: An 81-year-old man presented with massive epistaxis from the left nostril. The epistaxis was controlled by nasal packing. A saccular aneurysm of the cavernous segment of the left internal carotid artery projecting into the sphenoid sinus was revealed using computed tomography angiography. We treated this patient with high-flow bypass with ligation of the cervical internal carotid artery. Immediate postoperative computed tomography angiography showed complete disappearance of the aneurysm. Nasal packing was removed without further bleeding. No neurological deficit or complications were detected in the postoperative period. CONCLUSIONS: In cases of massive or recurrent epistaxis without coagulopathy or nasal pathology, a cavernous carotid aneurysm should be considered. Immediate cessation of the bleeding is necessary. Flow-preservation bypass with proximal ligation of the parent artery is 1 of the effective procedures for the treatment of this condition with low morbidity.