Neurosurgical focus最新文献

Objective: The authors examined the clipping of middle cerebral artery (MCA) aneurysms using the endoscopic transorbital approach (ETOA) with cadavers and in clinical cases to clarify which patients are good candidates based on preoperative imaging data.

Methods: To determine the indications for MCA clipping using an ETOA with superior-lateral orbital rim osteotomy, 10 sides of 5 cadavers were investigated. The clippable range, defined as the horizontal range, and exposure of the middle cranial fossa base, defined as the vertical extent area, were evaluated. To assess the ETOA trajectory in the MCA, the superior and inferior maximal angles based on the nasion-sella line were evaluated during cadaveric dissection. To test the surgical properties for actual use, 2 clinical cases were evaluated.

Results: The bases of the middle cerebral fossa, which were located below the sphenoid ridge, were accessible in all 5 cadavers. The suction tip and clip applier did not conflict with each other when access was made approximately 17.6 ± 3 mm (mean ± SD) laterally from the cranial midline and 6 ± 2 mm from the median temporal bone margin (clippable range). The superior angle was 16.7° ± 7.8°, and the inferior angle was 18.7° ± 9.6°. Two clinical cases underwent procedures using the ETOA. The aneurysms were at the MCA bifurcation in the anterior direction. The clippable ranges of the patients were 29 mm and 31 mm, respectively, and the distances from the midline to the median temporal bone margins were 32 mm and 36 mm. The M1 lengths were 14.5 mm and 17.2 mm, and the maximal diameters of the aneurysms were 3.58 and 3.67 mm.

Conclusions: Clipping using an ETOA is appropriate for MCA aneurysms with anterior, superior, and inferior dome projections. Aneurysms with a horizontal boundary from the anterior clinoid process to the lateral bone margin of the orbital ball and a vertical boundary around and below the sphenoid ridge can be properly clipped using the ETOA.

Objective: The aim of this study was to evaluate the feasibility, surgical techniques, and clinical outcomes of anterior cerebral artery (ACA) to middle cerebral artery (MCA) bypass using a radial artery (RA) graft in the treatment of complex MCA aneurysms.

Methods: A retrospective review was conducted on 11 patients with complex MCA aneurysms who underwent ACA-RA-MCA bypass between 2019 and 2025. Surgical details, intraoperative monitoring data, perioperative complications, and long-term graft patency and neurological outcomes were analyzed. Computational flow simulations were performed in selected cases to assess bypass flow rate.

Results: All patients (mean age 46.7 [SD 18.6] years) underwent ACA-RA-MCA bypass in a hybrid operating room setting. The A1 segment of the ACA was selected as the donor in 10 cases and the A2 segment in 1 case. Superficial temporal artery-MCA bypass was used as a supplementary or salvage treatment in 2 patients. Immediate graft patency was achieved in 9 patients. Two aneurysms required revision for intraoperative occlusion. No surgical deaths occurred. Infarction related to M1 perforator involvement was observed in 5 patients, whereas no infarctions occurred in ACA territories. At final follow-up (range 3-30 months), 9 patients had a modified Rankin Scale (mRS) score of 0-2 and 2 patients had an mRS score of 4. Long-term graft patency was 100%, and complete aneurysm obliteration was achieved in all cases.

Conclusions: ACA-RA-MCA bypass is a safe and durable revascularization option for selected complex MCA aneurysms, especially those unsuitable for direct clipping or flow diversion. The use of the ACA as a donor provides favorable hemodynamic and intraoperative flexibility, particularly when performed in a hybrid operating room. Despite risks of perforator-related ischemia, mastering and understanding this surgical technique still remains critically important and necessary in the treatment of complex MCA aneurysms.

Objective: High rates of retreatment remain a concern after endovascular therapy (EVT) for posterior circulation aneurysms. The authors aimed to analyze the indications and outcomes of microsurgery for posterior circulation aneurysms in the endovascular era.

Methods: A single institutional prospectively maintained database was queried from 2015 to 2025.

Results: Sixty-seven aneurysms were treated with microsurgery. Females comprised 55.2% (n = 37) of the cohort, and the median age was 55.4 years. Aneurysms were located along the posterior inferior cerebellar artery (PICA) in 23 patients, distal intracranial vertebral artery (VA) in 13, basilar apex in 12, posterior cerebral artery (PCA) in 11, and superior cerebellar artery (SCA) in 8. Twenty-five patients (37.3%) presented with acute rupture/subarachnoid hemorrhage (SAH). The median Hunt and Hess grade for patients who experienced SAH was II. The sizes of the aneurysms were < 4 mm in 8 patients, 4-10 mm in 34, 10-24 mm in 20, and > 24 mm in 5. Indications for microsurgery were complex anatomy in 22 patients, large thrombosed aneurysm not amenable to EVT in 13, residual aneurysm after prior EVT in 10, giant aneurysm in 9, distally located aneurysm in 10, partially thrombosed aneurysm in 3, residual aneurysm after prior clipping at an outside hospital in 6, mass effect in 2, and associated hematoma in 1. Microsurgical clip reconstruction was performed in 51 patients (76.1%), trapping with bypass in 5 (7.5%), parent vessel sacrifice in 3 (4.5%), trapping alone in 7 (10.4%), and wrapping in 1 (1.5%). Postoperative digital subtraction angiography (n = 61) confirmed complete occlusion in 54 patients (88.1%). Only 3.0% of patients (n = 2) needed retreatment for an enlarging residual among partially occluded aneurysms (n = 8, 11.9%). Complete occlusion was observed in 100% of SCA aneurysms (n = 8), 84.6% of VA aneurysms (n = 11/13), 90.9% of PCA aneurysms (n = 10/11), 85.7% of PICA aneurysms (18/23), and 75% of BA aneurysms (n = 7). The median follow-up was 27.8 months, and 60 patients (90%) were alive, of whom 55 (93.2%) had a modified Rankin Scale (mRS) score of 0 or 1. SAH-related mortality was seen in 5 patients (20%). Advanced age (p = 0.018) and prior treatment (p = 0.004) predicted poor clinical outcome (mRS score > 3 or mortality) in multivariate logistic regression analysis.

Conclusions: Microsurgical techniques yielded excellent complete occlusion rates with low morbidity. Only 3% of patients with posterior circulation aneurysms needed additional treatment for aneurysms that were not amenable to or cured with EVT.

Objective: For complex intracranial aneurysms (CIAs), extracranial-intracranial (EC-IC) bypass with immediate parent artery (PA) occlusion is an accepted strategy but is associated with a high postoperative infarction rate. This study explores the efficacy of a novel staged therapy, characterized by a first-stage EC-IC bypass followed by second-stage PA occlusion, with a focus on aneurysm change and hemodynamic outcomes.

Methods: Thirty-six patients with CIAs undergoing staged therapy from January 2018 to November 2022 were prospectively recruited. Hemodynamic analysis was performed using 4D flow MRI and computational fluid dynamics (CFD) based on CT angiography. Operation-related complications, postoperative hemodynamics, and aneurysm change were documented.

Results: Following first-stage bypass, aneurysms disappeared in 6 patients (16.7%), increased in size in 8 patients (22.2%), and remained unchanged in 22 patients (61.1%). Of the 16 cases (44.4%) available for 4D flow analysis, postoperative flow in the donor vessel increased gradually, peaking at 4.26 times the preoperative value by the 6th day after bypass, before subsequently decreasing. Hemodynamic patterns in the PA varied. In cases in which wall shear stress (WSS) and streamline velocity decreased (n = 4), 4D flow analysis revealed a decreasing trend in PA flow after the turning point, which corresponded with aneurysm resolution. Conversely, in cases with increased WSS and streamline velocity (n = 12), 4D flow analysis showed an increasing trend in PA flow after the turning point, corresponding with aneurysm enlargement or stability. Of 29 cases receiving second-stage PA occlusion, aneurysms disappeared in 27 patients (93.1%) and decreased in size in 2 patients (6.9%). Two patients developed ischemic events at 7 and 10 days postprocedure, respectively. At the latest follow-up, 91.7% (33/36) of the cases showed aneurysm resolution, without the development of hemorrhagic events.

Conclusions: Staged therapy appears to be a promising treatment for CIAs, yielding favorable outcomes. Hemodynamic evaluation is instrumental in assessing aneurysm changes after bypass and may help determine the optimal timing for second-stage treatment.

Objective: Medullary infarction (MI) is a known complication following the treatment of vertebral artery fusiform aneurysms (VAFAs), particularly when parent artery occlusion (PAO) is used. This condition can be attributed to delayed occlusion of medullary perforating arteries (Mperfs) due to a delayed thrombosis of the vertebral artery (VA) stump. Nevertheless, there is a limit to data regarding microsurgery, specifically those emphasizing Mperf preservation. Therefore, this study aimed to evaluate the indications, techniques, and outcomes of microsurgical management for unruptured VAFAs, focusing on maintaining the VA and Mperf integrity. The authors also propose a novel risk-stratified surgical algorithm based on Mperf classification to minimize MI complications.

Methods: The authors retrospectively reviewed patients with unruptured VAFAs who underwent microsurgical treatment between 2012 and 2024 at their institution. The Mperfs were evaluated intraoperatively and correlated with postoperative MRI findings to assess risk factors for MI. Based on their relation to the aneurysm, Mperfs were categorized as proximal, distal, aneurysm, or posterior inferior cerebellar artery (PICA) type, and further stratified into either "blind-end" or "flow-out" configurations regarding their vascular outflow characteristics following clipping procedures. Surgical strategies included PAO, various bypass techniques, and clip reconstruction. The clinical and radiological outcomes were also analyzed.

Results: Among the 54 patients with 58 aneurysms treated, favorable outcomes (modified Rankin Scale scores 0-2) were achieved in 96.3% of patients. Symptomatic MI occurred in 4 cases (6.9%), all within the blind-end Mperf group. Of the blind-end group, MI incidence was highest in aneurysm-type Mperfs (80%; 4/5), followed by distal (25%; 1/4) and proximal types (14.3%; 1/7). No MI was observed in the flow-out group. Larger aneurysm size and blind-end Mperf configuration, particularly when arising directly from the aneurysm, were significant risk factors for MI (p = 0.006 and p < 0.001, respectively). Revascularization procedures, including occipital artery (OA)-PICA, VA reconstruction utilizing an interposition graft, and OA-Mperf bypasses, were effectively performed, with no complications in bypass-protected Mperfs.

Conclusions: Microsurgical management of unruptured VAFAs, guided by a novel Mperf classification and a tailored surgical algorithm, was found to achieve excellent and durable results. The authors emphasize the importance of a thorough intraoperative Mperf evaluation and keep perforator-preserving techniques in mind, including strategic clipping and perforator bypass, to minimize the risk of MI. This study highlights the essential role of microsurgery in the contemporary management of complex posterior circulation aneurysms.

Objective: Basilar apex aneurysms have been considered challenging due to their deep location, intricate perforator anatomy, and large size and wide necks. However, advancements in skull base exposure and microvascular techniques, especially the extended pretemporal transcavernous approach, have proven to be indispensable in treating these aneurysms. In this article we aimed to assess the safety, efficacy, durability, and functional outcomes of microsurgical clipping of basilar apex aneurysms using the pretemporal transcavernous approach.

Methods: A retrospective review was conducted of all patients who underwent surgical treatment of basilar apex aneurysms performed by the senior author using the pretemporal transcavernous approach. Surgical exposure proceeded in a stepwise extraduralintradural manner, including anterior and posterior clinoidectomy, mobilization of CNs III to V, and systematic enlargement of the carotidoculomotor and oculomotortentorial windows. Temporary clips were applied to the basilar trunk at a perforator-free zone and on bilateral P1 segments. A sequential "pilot" clip followed by a definitive "smart" clip and bipolar dome remodeling were used to achieve occlusion while preserving perforators.

Results: From 1998 to 2024, 191 patients with 200 basilar apex aneurysms underwent microsurgical repair; 67.5% had unruptured aneurysms. Most of these aneurysms were complex, with 61% measuring > 7 mm. Early postoperative imaging in 105 patients demonstrated complete aneurysm obliteration in 102 (97%). Thirteen patients (6.8%) experienced minor ischemic events with no later sequelae, and 2 experienced lasting neurological deficits. Transient oculomotor palsy was universal but resolved in 92% of patients by 6 months and 99% by 1 year. Among patients with unruptured aneurysms, hospital mortality was 0.8%, and a good functional outcome (modified Rankin Scale score 0-2) was achieved in 88% at discharge and 97% at the final followup. The overall recurrence rate was 1.5%, with only 1 patient (0.8%) requiring retreatment.

Conclusions: The pretemporal transcavernous approach with microsurgical clipping yielded durable obliteration of basilar tip aneurysms with minimal morbidity and mortality, even in anatomically complex lesions. These findings reaffirm the continued relevance of the approach and, in many cases, the superiority of expert microsurgical clipping alongside endovascular techniques for treating these aneurysms.

The goal of intracranial aneurysm treatment is to exclude the lesion from the circulation while preserving the parent vessel and function in the neural tissues. Endovascular treatment (EVT) has been continually evolving with newer technological innovations, and with the advent of novel devices such as flow diverters and endosaccular flow disruption devices, has altered treatment decision-making for clinicians. Despite these advances, microsurgery continues to play an important role in the treatment of cerebral aneurysms. In general, while endovascular coiling and microsurgical clipping appear to yield similar long-term functional outcomes, the reduced procedure-related and short-term morbidity achieved with EVT comes with an increased rate of residual or recurrent disease and need for retreatment. This review provides practicing neurosurgeons with a summary of the various surgical techniques and adjuncts, an analysis of the available clinical data, and assistance in individualized decision-making by analyzing ideal or less-than-ideal scenarios for a given technique.