The foramen ovale "mirage" and how this impacts percutaneous cannulation for treatment of trigeminal neuralgia: a report of two cases.

Percutaneous stereotactic radiofrequency rhizotomy (PSR) for trigeminal neuralgia most commonly utilizes 2D fluoroscopy for intraoperative needle guidance into the foramen ovale (FO). We describe two cases in which needle advancement into FO was unachievable despite appropriate needle placement on biplane fluoroscopy. Intraoperative multiplanar reconstruction was helpful in more accurately depicting foraminal anatomy which allowed the manipulation of the tip of the needle, which was followed by successful FO cannulation. We propose that this "mirage" is likely created by the inherent nature of X-ray-based fluoroscopy in which the FO appears to be readily penetrable, when in fact the 3D anatomy actually prevents cannulation.

BOBBY balloon guide catheter thrombectomy in large-vessel occlusion stroke: Initial experience.

BACKGROUND AND PURPOSE: Nonrandomized studies have found Balloon Guide Catheter (BGC) use to improve technical and functional outcomes in patients undergoing mechanical thrombectomy (MT). MATERIALS AND METHODS: We performed a retrospective analysis on prospectively collected data of consecutive ischemic stroke patients undergoing MT at our institution (December 2020-October 2021). Interventions where BOBBY BGC (BBGC, MicroVentionTM, Aliso Viejo, CA) was used were identified. Baseline demographics and clinico-radiographic characteristics were retrospectively collected and analysed using descriptive statistics. RESULTS: A total of 43 patients received BBGC-MT (male: female = 26:17, median age 72 years [IQR 62-82]). The most common occlusion site was the middle cerebral artery (MCA) (60.4%). Over half (51.2%) received intravenous thrombolytics. The BBGC tracked well over tortuous aortic arches (type II 34.8%, type III 16.3%), with median arteriotomy-to-perfusion time of 29 min (IQR 20-46). Thromboaspiration was used as first-line MT technique in 69.7% cases, with 1 (IQR 1-2) median MT pass achieving modified TICI (thrombolysis in cerebral ischemia) scores of 3 and 2b/3 in 74.4% and 95.3% respectively. Our overall first pass effect (FPE, defined as mTICI 3 after firs-pass) and modified FPE (defined as, mTICI 2b/3 after first-pass) rates were 51.1% and 79.1% respectively, with rates of 92.3% and 100% respectively when stentretriever and thromboaspiration were combined. The median reduction in National Institutes of Health Stroke Scale (NIHSS) was 9 (IQR 4-15, p < 0.0001), with a median 90-day modified Rankin Score (mRS) of 1.5 (IQR 0-2). CONCLUSIONS: BOBBY BGC use resulted in a high first-pass effect rate and may contribute towards improved functional outcomes.

Trans-radial spinal angiography: A single-center experience.

INTRODUCTION: Spinal angiography (SpAn) is the gold standard for diagnosis of spinal dural fistulas and arteriovenous malformations. A complete spinal angiogram necessitates the interrogation of the segmental arteries arising from the aorta at every level as well, the internal iliac; and median sacral arteries at the caudal end; and the cervical vasculature at the cranial end. SpAn has traditionally been performed with transfemoral arterial access and could be challenging. Of late, transradial arterial access has emerged as a popular alternative for endovascular surgical Neuroradiology (ESN) procedures including SpAn. However, there is paucity of the literature regarding transradial access for spinal angiography. METHODS: After IRB approval, records and imaging were reviewed in a series of patients who underwent SpAn at our institution. RESULTS: A total of nine spinal angiograms were performed via transradial access in a consecutive series of eight patients between July 2019 and December 2020 at our institution. Eight of these were diagnostic SpAn's, and one patient underwent SpAn with transradial approach for the treatment of a type I spinal dural arteriovenous fistula. No complications occurred during or subsequent to the procedures. CONCLUSION: SpAn can be successfully and safely accomplished via transradial access. This approach appears to provide a stable method for interventions, as well.

The practical limits of high-quality magnetic resonance imaging for the diagnosis and classification of trigeminal neuralgia.

BACKGROUND: Neurovascular compression (NVC) has been the primary hypothesis for the underlying mechanism of classical trigeminal neuralgia (TN). However, a substantial body of literature has emerged highlighting notable exceptions to this hypothesis. The purpose of this study is to assess the reliability and diagnostic accuracy of high resolution, high contrast MRI-determined neurovascular contact for TN. METHODS: We performed a retrospective, randomized, and blinded parallel characterization of neurovascular interaction and diagnosis in a population of TN patients and controls using four expert reviewers. Performance statistics were calculated, as well as assessments for generalizability using shuffled bootstraps. RESULTS: Fair to moderate agreement (ICC: 0.32-0.68) about diagnosis between reviewers was observed using MRIs from 47 TN patients and 47 controls. On average reviewers performed no better than chance when diagnosing participants, with an accuracy of 0.57 (95% CI 0.40, 0.59) per patient. CONCLUSION: While MRI is useful in determining structural causes in secondary TN, expert reviewers do no better to only slightly better than chance with distinguishing TN with MRI, despite moderate agreement. Further, the causal role of NVC for TN is not clear, limiting the applicability of MRI to diagnose or prognosticate treatment of TN.

Effectiveness of alternative routes of intra-arterial chemotherapy administration for retinoblastoma: Potential for response and complications.

OBJECTIVE: Intra-arterial chemotherapy (IAC) is now the first line treatment for selected patients with retinoblastoma (Rb). Typically, IAC is infused following the selective catheterization of the ophthalmic artery (OA) on the affected side. However, in some patients, the OA alone may not provide vascular supply to the tumor, whereas in other instances the efficacy of IAC could be compromised due to the presence of prominent collateral vessels from the external carotid artery (ECA). We report our experience with catheterizing vessels other than the OA for IAC treatment for Rb. METHODS: After institutional review board approval, a retrospective analysis was conducted of electronic medical records and imaging of our Rb population. RESULTS: We identified 13 patients who received IAC for Rb treatment. Of these, five patients required alternative methods of chemotherapy delivery other than through the OA, totaling 17 treatments. Two patients needed balloon-assisted occlusion of the ECA, two patients required selective catheterization of the middle meningeal artery, and one patient had no internal carotid artery supply to the choroidal blush, thus the superficial temporal artery provided access for IAC. Total globe salvage rate was 76% and 80% with the alternative route subset. CONCLUSIONS: Alternatives to the OA may be necessary to deliver IAC for selected cases of Rb. These routes can be safe and effective. However, thorough understanding of the orbital blood supply is essential. Whether these alternative IAC methods result in similar outcomes to OA infusions has not been established.

Gadolinium to the rescue for mechanical thrombectomy in acute ischemic stroke.

INTRODUCTION: Mechanical thrombectomy in the setting of acute ischemic stroke (AIS) requires cerebral digital subtraction angiography (DSA), typically performed with iodinated contrast medium. We present a case of emergent cerebral DSA and mechanical thrombectomy using gadolinium-based contrast for cerebral DSA in a patient with a history of anaphylaxis to iodinated contrast agents (ICs). CASE REPORT: A 72-year-old man developed left ventricle assist device thrombus while on anticoagulation. During hospitalization he suffered right middle cerebral artery occlusion with a National Institutes of Health stroke scale score of 10. He had a history of anaphylaxis and the advanced directives revealed do not resuscitate/do not intubate status. We performed an emergent DSA as part of thrombectomy procedure using gadolinium-based contrast mixed in 1:1 proportion with normal saline. The images obtained were of adequate quality and the patient underwent successful thrombectomy with modified thrombolysis in cerebral infarction 2B recanalization. CONCLUSION: Gadolinium-based contrast agents could be effective alternatives for cerebral DSA in patients undergoing mechanical thrombectomy for AIS who have a history of anaphylactic reaction to ICs.

Institutional and provider variations for mechanical thrombectomy in the treatment of acute ischemic stroke: a survey analysis.

INTRODUCTION: Stent retriever combined with aspiration, or the 'Solumbra technique', has recently emerged as one of the popular methods of mechanical thrombectomy (MT). However, the variations in understanding and implementation of the Solumbra technique have not been reported. METHODS: An 18 part anonymous survey questionnaire was designed to extract information regarding technical variations of MT with a focus on the Solumbra technique. The survey link was posted on the Society of Neurointerventional Surgery (SNIS) website in 'SNIS connect'. RESULTS: 80 responses were obtained over 4 weeks that were included in the final analysis. Direct aspiration without a balloon guide catheter (BGC) was the most favored technique among respondents (41.12%) followed by the Solumbra technique without a BGC (32.4%). Among those using the Solumbra technique, 77.6% reported that they wait between 2 and 5 min to allow clot engagement, 55.2% always remove the microcatheter before aspiration, and 69.1% commence aspiration through the intermediate catheter only when retrieving the stent retriever. Operators who infrequently used or did not use BGCs reported a higher incidence of >80% Thrombolysis in Cerebral Infarction 2b/3 annual recanalization rates (OR 8.85, 95% CI 2.03 to 38.55, P=0.004) compared with those who consistently used BGCs. CONCLUSION: Our study documents the variations in MT techniques, and more specifically, attempts to quantify variations in the Solumbra technique. The impact of these variations on recanalization rates and eventually patient outcomes are unclear, especially given the self-reported outcomes contained in this study.

Creation of an External Ventricular Drain Registry from a Quality Improvement Project.

BACKGROUND: External ventricular drains (EVDs) are a serious source of morbidity and mortality. Data for interventions proven to reduce risk of infections are lacking. Single-center studies are limited in studying procedures that mitigate infection, but bundled protocols have demonstrated utility. A collaborative EVD registry was designed to facilitate local quality improvement projects to be implemented at any location using standardized data collection instruments through resident collaboration to reduce and study EVD infection and prevention. METHODS: A bundled protocol and comprehensive implementation program were developed as a quality improvement project to reduce ventriculostomy-associated infections. Standardized data collection forms were created for multi-institutional participation in an EVD registry. Retrospective and prospective patient data were documented in an electronic procedural registry, which was designed to capture variation among multiple institutions. RESULTS: Two infections were found in 1924 EVD-days before protocol implementation; no infections were found in 700 EVD-days after protocol implementation. Baseline epidemiology of EVDs was calculated in preparation for comparison. A resident-driven EVD consortium, now with 5 other member institutions, was founded to collect data for an EVD registry fed by individual site quality improvement initiatives. CONCLUSIONS: The ventriculostomy-associated infection rate at the University of Minnesota is low compared with the literature. Rationally bundled protocols have mounting evidence but do not allow for identifying effective individual components. Through the registry described here, others can join the EVD consortium to contribute data to facilitate comparative effectiveness research with minimal investment.

Acute correction of hyponatremia secondary to psychogenic polydipsia.

BACKGROUND: Psychogenic polydipsia is prevalent amongst psychiatric patients, but less common in the general population. Generally, hyponatremia ensues with complications of cerebral edema resulting in confusion, seizures, coma, and death. Rapid correction of serum sodium levels can lead to further complications of osmotic demyelination of neurons, e.g. central pontine myelinolysis. CASE REPORT: We present a case of a 32-year-old male who presented with seizures while being treated at a drug rehabilitation facility. He was discovered to be hyponatremic secondary to suspected psychogenic polydipsia. The patient impressively responded to treatment of fluid restriction and desmopressin and symptoms improved. CONCLUSIONS: Among the causes of hyponatremia, psychogenic polydipsia may be more difficult to diagnose especially if an apparent psychiatric condition is not present. Current literature supports cautious correction of hyponatremia to prevent complications. However, rapid corrections may be driven by the physiology of the patient and may not be avoidable. Fortunately, our case illustrates rapid, positive outcomes for the patient.