Faculty Bibliography

BACKGROUND:The transradial artery (TRA) approach for neuroendovascular procedures continues to gain popularity, but neurointerventionalists still lag behind interventional cardiologists in the adoption of a TRA-first approach. This study compares the complications and efficiency of the TRA approach to the standard transfemoral artery (TFA) approach at our institution during our initial phase of adopting a TRA-first approach. METHODS:A retrospective analysis was performed on all consecutive neuroangiographic procedures performed at a large cerebrovascular center from October 1, 2018 to June 30, 2019. The standard TFA approach was compared with TRA access, with the primary outcome of complications analyzed via a propensity-adjusted analysis. RESULTS:A total of 1050 consecutive procedures were performed on 877 patients during this 9-month period; 206 (20%) procedures were performed via TRA and 844 (80%) via TFA. The overall complication rate was significantly higher with the TFA procedures than with the TRA procedures (7% (60/844) vs 2% (4/206), respectively; p=0.003). A propensity-adjusted analysis showed that the TFA approach was a significant risk factor for a complication (OR 3.6, 95% CI 1.3 to 10.2, p=0.01). However, the propensity analysis showed that fluoroscopy times were on average 4 min less for TFA procedures than for TRA procedures (p=0.003). CONCLUSION/CONCLUSIONS:The TRA approach for neuroendovascular procedures appears to be safer than the TFA approach. Although a steep learning curve is initially encountered when adopting the TRA approach, the transition to a TRA-first practice can be performed safely for neurointerventional procedures and may reduce complications.

BACKGROUND:Moyamoya disease (MMD) is a rare cause of cerebral hemorrhage and ischemia. Spontaneous development of collateral supply from the external carotid artery (ECA) may limit the use of donor arteries used in standard direct bypass techniques. OBJECTIVE:To identify the technical feasibility of side-to-side (S-S) superficial temporal artery to middle cerebral artery (STA-MCA) bypass and demonstrate the application of fourth generational bypass techniques in the treatment of MMD. METHODS:S-S bypass was performed in order to maintain distal outflow in the donor STA. Fourth generation bypass techniques, including atypical anastomosis construction and intraluminal suturing were utilized. RESULTS:The novel S-S STA-MCA bypass was performed, with patent flow in both recipient MCA and endogenous ECA-ICA collaterals supplied by the distal STA. Technical nuances, including proper alignment of donor vessel, tension reduction, and S-S anastomosis construction with intraluminal suturing technique are essential for successful bypass. Unique flow properties of this bypass were identified, resulting in flow augmentation to the recipient territory compared to standard end-to-side (E-S) techniques. CONCLUSION:Fourth generational bypass techniques can be successfully applied to MMD, allowing for novel bypass construction. S-S anastomosis can result in potentially beneficial flow properties compared to standard E-S constructions.

Supracerebellar transtentorial (SCTT) approaches have become a popular option for treatment of a variety of pathologies in the medial and basal temporal and occipital lobes and thalamus. Transtentorial approaches provide numerous advantages over transcortical approaches, including obviating the need to traverse eloquent cortex, not requiring parenchymal retraction, and circumventing critical vascular structures. All of these approaches require a tentorial opening, and numerous techniques for retraction of the incised tentorium have been described, including sutures, fixed retractors, and electrocautery. However, all of these techniques have considerable drawbacks and limitations. The authors describe a novel application of clip retraction of the tentorium to the supracerebellar approaches in which an aneurysm clip is used to suspend the tentorial flap, and an illustrative case is provided. Clip retraction of the tentorium is an efficient, straightforward adaptation of an established technique, typically used for subtemporal approaches, that improves visualization and surgical ergonomics with little risk to nearby venous structures. The authors find this technique particularly useful for the contralateral SCTT approaches.

OBJECTIVE:The controversy continues over the clinical utility of preoperative embolization for reducing tumor vascularity of intracranial meningiomas prior to resection. Previous studies comparing embolization and nonembolization patients have not controlled for detailed tumor parameters before assessing outcomes. METHODS:The authors reviewed the cases of all patients who underwent resection of a WHO grade I intracranial meningioma at their institution from 2008 to 2016. Propensity score matching was used to generate embolization and nonembolization cohorts of 52 patients each, and a retrospective review of clinical and radiological outcomes was performed. RESULTS:In total, 52 consecutive patients who underwent embolization (mean follow-up 34.8 ± 31.5 months) were compared to 52 patients who did not undergo embolization (mean follow-up 32.8 ± 28.7 months; p = 0.63). Variables controlled for included patient age (p = 0.82), tumor laterality (p > 0.99), tumor location (p > 0.99), tumor diameter (p = 0.07), tumor invasion into a major dural sinus (p > 0.99), and tumor encasement around the internal carotid artery or middle cerebral artery (p > 0.99). The embolization and nonembolization cohorts did not differ in terms of estimated blood loss during surgery (660.4 ± 637.1 ml vs 509.2 ± 422.0 ml; p = 0.17), Simpson grade IV resection (32.7% vs 25.0%; p = 0.39), perioperative procedural complications (26.9% vs 19.2%; p = 0.35), development of permanent new neurological deficits (5.8% vs 7.7%; p = 0.70), or favorable modified Rankin Scale (mRS) score (a score of 0-2) at last follow-up (96.0% vs 92.3%; p = 0.43), respectively. When comparing the final mRS score to the preoperative mRS score, patients in the embolization group were more likely than patients in the nonembolization group to have an improvement in mRS score (50.0% vs 28.8%; p = 0.03). CONCLUSIONS:After controlling for patient age, tumor size, tumor laterality, tumor location, tumor invasion into a major dural sinus, and tumor encasement of the internal carotid artery or middle cerebral artery, preoperative meningioma embolization intended to decrease tumor vascularity did not improve the surgical outcomes of patients with WHO grade I intracranial meningiomas, but it did lead to a greater chance of clinical improvement compared to patients not treated with embolization.

Background and Purpose- The CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial) demonstrated equivalent composite outcomes between carotid endarterectomy (CEA) and carotid artery stenting (CAS) for treating carotid stenosis. We investigated nationwide trends in these procedures and associated periprocedural stroke, myocardial infarction, death, cost, and readmission rates since CREST outcomes were published. Methods- We queried the Nationwide Readmissions Database to identify patients undergoing CEA and CAS for asymptomatic and symptomatic carotid stenosis from 2010 to 2015. Patients were matched based on demographics, comorbidities, and severity of illness. Results- In total, 378 354 CEA and 57 273 CAS patients were treated during this 6-year period. CEA volume decreased by an average of 2669 procedures annually (P=0.001) with stable CAS volume (P=0.225). After matching, CEA patients had a higher rate of periprocedural stroke than CAS patients, driven by increased stroke risk in symptomatic CEA patients (8.1% versus 5.6%; odds ratio, 1.47 [CI, 1.29-1.68]; P<0.001) but a lower rate of overall inpatient mortality (0.8% versus 1.4%; odds ratio, 0.57 [CI, 0.48-0.68]; P<0.001). CEA patients were less likely to be readmitted within 30 days (7.2% versus 8.0%; odds ratio, 0.90 [CI, 0.84-0.96]; P=0.018) and 90 days (12.3% versus 14.1%; odds ratio, 0.86 [CI, 0.81-0.90]; P<0.001), and mean hospital costs were lower for CEA compared with CAS ($14 433 versus $19 172; P<0.001). Conclusions- The procedural treatment of carotid stenosis has changed dramatically in the post-CREST era. When matched for characteristics and illness severity, patients undergoing CEA had a higher rate of perioperative stroke than patients undergoing CAS, primarily among symptomatic patients. These findings are in contrast to the findings of CREST, which showed nearly twice the risk of stroke in CAS patients compared with CEA patients. CEA was associated with lower procedure cost and readmission rate.