Emergency Superficial Temporal Artery-Superior Cerebellar Artery Bypass for the Refractory Vertebrobasilar Insufficiency with Partial Mastoidectomy

Secondary Benefits of Microsurgical Intervention on the Vertebral Artery (V1 Segment) for Refractory Vertebrobasilar Insufficiency: Alleviation of Parkinsonism-Like Symptoms

OBJECTIVE

The objective of this study was to investigate the outcomes of microneurosurgical interventions on V1 segment of the vertebral artery in patients with refractory vertebrobasilar insufficiency (VBI) due to dolicoarteriopathy and external compressions and to assess the secondary benefits of Parkinsonism-like symptoms.

METHODS

Retrospective analysis encompassed 101 patients treated for vertebral artery dolicoarteriopathy or compression-related refractory VBI from 2016 to 2023. Of these, 16 patients exhibited drug-resistant Parkinsonism-like symptoms. The diagnostic evaluation included cerebral computed tomography/magnetic resonance angiography or digital subtraction angiography and brain computed tomography or magnetic resonance perfusion studies, corroborated by preoperative and 6- and 12-month postoperative Movement Disorder Society-Unified Parkinson's Disease Rating Scale Part 3 assessments. Data were analyzed through Turkey's "E-nabız" system, employing Stata16 for statistical scrutiny.

RESULTS

A significant reduction in Movement Disorder Society-Unified Parkinson's Disease Rating Scale scores was observed (preoperative: 26.75±10.91; 6 months: 23.09±9.24; 12 months: 22.5±8.73; P < 0.001). Postoperative follow-up denoted that 43.7% of patients ceased medication and 50% reduced antiparkinsonian drugs. The microneurosurgical approach resulted in complete remission of VBI-related symptoms in 84.6% of patients, with the rest showing partial or marked improvement. At 6 months postoperation, perfusion studies revealed posterior border zone or cerebellar perfusion enhancements in 81% (13 out of 16) of patients, with full symptom resolution, while the remaining 19% (3 out of 16) showed partial perfusion and clinical improvements, particularly in regions supplied by the posterior cerebellar artery or posterior inferior cerebellar artery. The absence of operative mortality and minimal transient morbidities underscored the procedure's safety.

CONCLUSIONS

Microneurosurgery for vertebral artery anomalies in refractory VBI patients, particularly those with concomitant parkinsonian-like syndromes, has demonstrated potential in symptom remission and medication reduction.

Advantages of petrosectomy for superficial temporal artery to superior cerebellar artery bypass based on three-dimensional distance measurements using cadaver heads

Superficial temporal artery (STA) to superior cerebellar artery (SCA) bypass is usually performed via the subtemporal approach (StA), anterior transpetrosal approach (ApA), or combined petrosal approach (CpA), but no study has yet reported a quantitative comparison of the operative field size provided by each approach, and the optimal approach is unclear. The objective of this study is to establish evidence for selecting the approach by using cadaver heads to measure the three-dimensional distances that represent the operative field size for STA-SCA bypass. Ten sides of 10 cadaver heads were used to perform the four approaches: StA, ApA with and without zygomatic arch osteotomy (ApA-ZO^- and ApA-ZO⁺), and CpA. For each approach, the major-axis length and the minor-axis length at the anastomosis site (La-A and Li-A), the major-axis length and the minor-axis length at the brain surface (La-B and Li-B), the depth from the brain surface to the anastomosis site (Dp), and the operating angles of the major axis and the minor axis (OAa and OAi) were measured. Shallower Dp and wider operating angle were obtained in the order CpA, ApA-ZO⁺, ApA-ZO^-, and StA. In all parameters, ApA-ZO^- extended the operative field more than StA. ApA-ZO⁺ extended La-B and OAa more than ApA-ZO^-, whereas it did not contribute to Dp and OAi. CpA significantly decreased Dp, and widened OAa and OAi more than ApA-ZO⁺. ApA and CpA greatly expanded the operative field compared with StA. These results provide criteria for selecting the optimal approach for STA-SCA bypass in light of an individual surgeon's anastomosis skill level.