Basilar decompression via a far lateral transcondylar approach: technical note.

BACKGROUND: Treatments for symptomatic or unstable basilar invagination (BI) include posterior decompression, distraction/fusion, trans-nasal or trans-oral anterior decompression, and combined techniques, with the need for occipitocervical fusion based on the degree of craniocervical instability. Variations of the far lateral transcondylar approach are described in limited case series for BI, but have not been widely applied. METHODS: A single-institution, retrospective review of consecutive patients undergoing a far lateral transcondylar approach for odontoidectomy (± resection of the inferior clivus) followed by occipitocervical fusion over a 6-year period (1/1/2016 to 12/31/2021) is performed. Detailed technical notes are combined with images from cadaveric dissections and patient surgeries to illustrate our technique using a lateral retroauricular incision. RESULTS: Nine patients were identified (3 males, 6 females; mean age 40.2 ± 19.6 years). All patients had congenital or acquired BI causing neurologic deficits. There were no major neurologic or wound-healing complications. 9/9 patients (100%) experienced improvement in preoperative symptoms. CONCLUSIONS: The far lateral transcondylar approach provides a direct corridor for ventral brainstem decompression in patients with symptomatic BI. A comprehensive knowledge of craniovertebral junction anatomy is critical to the safe performance of this surgery, especially when using a lateral retroauricular incision.

Surgical Relevance of the Suprameatal Tubercle During Superior Petrosal Vein-Sparing Trigeminal Nerve Microvascular Decompression.

BACKGROUND: An enlarged suprameatal tubercle (SMT) can obscure visualization of the trigeminal nerve and require removal during microvascular decompression (MVD) surgery, especially when the superior petrosal vein (SPV) complex is preserved. OBJECTIVE: To define the incidence and important variables affecting the need for SMT removal with an SPV-sparing trigeminal nerve MVD. METHODS: Retrospective single-institution review identified patients who underwent a first-time, SPV-sparing MVD for trigeminal neuralgia (TGN) over a 26-mo period. SMT length (SMT-L), SMT width (SMT-W), and peri-trigeminal cerebellopontine cisternal thickness (CT) were measured from axial high-resolution magnetic resonance images. Need for SMT removal and use of endoscopic assistance was recorded. Data were analyzed using unpaired t-tests, and receiver operating characteristic (ROC)/area under the curve testing. RESULTS: A total of 43 MVD surgeries for TGN on 42 patients (mean age 52.7 ± 14.4 yr) were analyzed. Mean SMT-L, SMT-W, and CT were 9.8 ± 1.6, 2.0 ± 0.8, and 4.2 ± 1.5 mm, respectively. SMT removal via drilling was required in 4/43 cases (9.3%). Endoscopic assistance was used in 3 cases (2 SMT removed and 1 SMT preserved). SMT-W was the biggest predictor of the need for SMT removal on ROC analysis (area under the curve 0.97, 0.92-1.0 95% CI). The combined thresholds of SMT-W ≥ 3.2 mm and CT ≤ 3.5 mm demonstrated 100% sensitive and 100% specificity for the need to remove the SMT on optimal cutoff analysis. CONCLUSION: SMT drilling is necessary in nearly 10% of SPV-sparing MVDs for TGN. The combination of SMT width and cerebellopontine cistern thickness is predictive of the need for SMT removal.

Neurosurgical Management of Sacral Tumors: Review of the Literature and Operative Nuances.

BACKGROUND: Sacral tumors present a significant challenge to the spine surgeon. As new techniques have evolved in recent years, these lesions have become more amenable to aggressive surgical treatment. Although sacral tumors make up only a small minority of spinal tumors, their surgical management warrants special consideration. METHODS: Based on our experience, we highlight 3 important surgical nuances specifically for the treatment of sacral tumors: preservation and maximization of neurologic function, protection of ventral abdominal and pelvic structures, and lumbopelvic fixation. RESULTS: Two cases of patients with sacral tumors treated at our institution are presented to illustrate these points. Both patients had successful postoperative courses, and remained pain free, well-fixated, and neurologically intact at 3-4 month follow-up. They had no evidence of biomechanical instability. CONCLUSIONS: To ensure a successful outcome, a goal-directed, methodical approach is required.

Evaluation of previously embolized intracranial aneurysms: inter-and intra-rater reliability among neurosurgeons and interventional neuroradiologists.

BACKGROUND: The angiographic evaluation of previously coiled aneurysms can be difficult yet remains critical for determining re-treatment. OBJECTIVE: The main objective of this study was to determine the inter-rater reliability for both the Raymond Scale and per cent embolization among a group of neurointerventionalists evaluating previously embolized aneurysms. METHODS: A panel of 15 neurointerventionalists examined 92 distinct cases of immediate post-coil embolization and 1 year post-embolization angiographs. Each case was presented four times throughout the study, along with alterations in demographics in order to evaluate intra-rater reliability. All respondents were asked to provide the per cent embolization (0-100%) and Raymond Scale grade (1-3) for each aneurysm. Inter-rater reliability was evaluated by computing weighted kappa values (for the Raymond Scale) and intraclass correlation coefficients (ICC) for per cent embolization. RESULTS: 10 neurosurgeons and 5 interventional neuroradiologists evaluated 368 simulated cases. The agreement among all readers employing the Raymond Scale was fair (κ=0.35) while concordance in per cent embolization was good (ICC=0.64). Clinicians with fewer than 10 years of experience demonstrated a significantly greater level of agreement than the group with greater than 10 years (κ=0.39 and ICC=0.70 vs κ=0.28 and ICC=0.58). When the same aneurysm was presented multiple times, clinicians demonstrated excellent consistency when assessing per cent embolization (ICC=0.82), but moderate agreement when employing the Raymond classification (κ=0.58). CONCLUSIONS: Identifying the per cent embolization in previously coiled aneurysms resulted in good inter- and intra-rater agreement, regardless of years of experience. The strong agreement among providers employing per cent embolization may make it a valuable tool for embolization assessment in this patient population.

Impact of Surgical Specialty on Outcomes Following Carotid Endarterectomy.

Background: The impact of surgeon specialty on outcomes following carotid endarterectomy (CEA) has been widely debated within the literature. Previous studies on this subject are often limited by small sample sizes, single-intuition designs, variability in patients and procedures, and potential confounding factors such as institution type and volume. Objective: To identify similarities and differences between surgeon specialties in postoperative stroke and mortality rates for patients undergoing unilateral CEAs by utilizing a large, multicenter prospective database. Methods: We utilized a large national prospective database (National Surgical Quality Inpatient database) and investigated all patients with a 1-sided, surgically naïve CEA, performed by either a general, vascular, cardiothoracic, or neurological surgeon. We employed a logistic regression analysis to control for the most salient variables identified via univariate analysis. Our primary outcomes were all-cause mortality and stroke. Results: There were 42 369 patients included across all specialties. Patients from each specialty were similar in demographics but varied in medical history. Multivariate analysis demonstrated that among the specialties only general surgeons had significantly greater postoperative stroke rates (2.3%) when compared to vascular surgeons (1.5%; P = .003, odds ratio [OR] 1.574, confidence interval [CI]: 1.168-2.121). In contrast, surgical specialty was not a significant risk factor for 30-d postoperative mortality (0% in cardiothoracic surgeons; 0.8% in vascular surgeons; 1.1% in general surgeons; 1.8% in neurosurgeons; Cardiothoracic surgeons: P = .995, OR: 0 [no incidences of mortality]; neurosurgeon: P = .118, OR: 0.2057, CI: 0.833-2.057; general surgeon P = .210, OR: 1.326, CI: 1.853-2.062). Most secondary outcomes (myocardial infarction, infection, reoperation, pneumonia) were similar between specialties (P = .339-.816). However, length of stay (P < .001), operative duration (P < .001), incidence of venous thromboembolism (P < .001), and the postoperative requirement for a ventilator greater than 48 h (P = .004) were all the greatest among neurosurgeons. Conclusion: Multidisciplinary approaches with improved communication among surgical specialties may enhance patient management and improve success after CEA. Though there were differences in postoperative stroke and other secondary outcomes, no differences were observed among specialties in mortality after unilateral CEA in more than 40 000 patients.

CYP2C19 and CES1 polymorphisms and efficacy of clopidogrel and aspirin dual antiplatelet therapy in patients with symptomatic intracranial atherosclerotic disease.

OBJECT Symptomatic intracranial atherosclerotic disease (ICAD) has a high risk of recurrent stroke. Genetic polymorphisms in CYP2C19 and CES1 are associated with adverse outcomes in cardiovascular patients, but have not been studied in ICAD. The authors studied CYP2C19 and CES1 single-nucleotide polymorphisms (SNPs) in symptomatic ICAD patients. METHODS Genotype testing for CYP2C19*2, (*)3, (*)8, (*)17 and CES1 G143E was performed on 188 adult symptomatic ICAD patients from 3 medical centers who were medically managed with clopidogrel and aspirin. Testing was performed prospectively at 1 center, and retrospectively from a DNA sample biorepository at 2 centers. Multiple logistic regression and Cox regression analysis were performed to assess the association of these SNPs with the primary endpoint, which was a composite of transient ischemic attack (TIA), stroke, myocardial infarction, or death within 12 months. RESULTS The primary endpoint occurred in 14.9% of the 188 cases. In multiple logistic regression analysis, the presence of the CYP2C19 loss of function (LOF) alleles *2, *3, and *8 in the medically managed patients was associated with lower odds of primary endpoint compared with wild-type homozygotes (odds ratio [OR] 0.13, 95% CI 0.03-0.62, p = 0.0101). Cox regression analysis demonstrated the CYP2C19 LOF carriers had a lower risk for the primary endpoint, with hazard ratio (HR) of 0.27 (95% CI 0.08-0.95), p = 0.041. A sensitivity analysis of a secondary composite endpoint of TIA, stroke, or death demonstrated a significant trend in multiple logistic regression analysis of CYP2C19 variants, with lower odds of secondary endpoint in patients carrying at least 1 LOF allele (*2, *3, *8) than in wild-type homozygotes (OR 0.27, 95% CI 0.06-1.16, p = 0.078). Cox regression analysis demonstrated that the carriers of CYP2C19 LOF alleles had a lower risk forthe secondary composite endpoint (HR 0.22, 95% CI 0.05-1.04, p = 0.056). CONCLUSIONS This is the first study examining genetic variants and their effects in symptomatic ICAD. Variant alleles of CYP2C19 (*2, *3, *8) were associated with lower odds of the primary and secondary composite endpoints. However, the direction of the association was opposite of what is expected based on this SNP. This may reflect an incomplete understanding of this genetic variation and its effect in symptomatic ICAD and warrants further investigations.

Physiologic imaging in acute stroke: Patient selection.

Treatment of acute stroke is changing, as endovascular intervention becomes an important adjunct to tissue plasminogen activator. An increasing number of sophisticated physiologic imaging techniques have unique advantages and applications in the evaluation, diagnosis, and treatment-decision making of acute ischemic stroke. In this review, we first highlight the strengths, weaknesses, and possible indications for various stroke imaging techniques. How acute imaging findings in each modality have been used to predict functional outcome is discussed. Furthermore, there is an increasing emphasis on using these state-of-the-art imaging modalities to offer maximal patient benefit through IV therapy, endovascular thrombolytics, and clot retrieval. We review the burgeoning literature in the determination of stroke treatment based on acute, physiologic imaging findings.