Detethering the superficial temporal artery: Application to tension free superficial temporal artery-middle cerebral artery bypasses.

Extracranial-intracranial bypass has been shown to be effective in the surgical treatment of moyamoya disease, complex aneurysms, and tumors that involve proximal vasculature in carefully selected patients. Branches of the superficial temporal artery (STA) are used commonly for the bypass surgery; however, an appropriate length of the donor vessel must be harvested to avoid failure secondary to anastomotic tension. The goal of this cadaveric study was to investigate quantitatively operative techniques that can increase the STA length available to facilitate tension-free STA-middle cerebral artery (MCA) bypass. We conducted a cadaveric study using a total of 16 sides in eight cadavers. Measurements of the STA trunk with its frontal branch (STAfb) were taken before and after skeletonization and detethering of the STA with the STAfb and mobilization of the parietal branch of the STA. A final measurement of the STA with the STAfb was taken for the free length gained toward visible proximal cortical branches of the MCA. Paired student's t-tests were used to compare the mean length before and after mobilization and unpaired t-tests to analyze according to laterality. The mean length of the STA with the STAfb was 9.0 cm prior to modification. After skeletonization and mobilization, the mean lengths increased significantly to 10.5 and 11.3 cm, respectively (p < 0.05). Especially in the cases that had the coiled and tortuous STA, skeletonization was considerably effective to increase the length of the STA with the STAfb. After simulating a bypass by bringing the STAfb to the recipient MCA site, the mean extended length of the STA with the STAfb was 3.0 cm. There were no statistically significant differences between sides in all measurements. We report a significant increase in the mean STA length available (3.0 cm) following skeletonization and mobilization. Clinical applications of the extended length of the STA with the STAfb may facilitate tension-free STA-MCA bypasses and improve outcomes. Further studies are needed in a clinical context.

Postpartum-Onset Moyamoya Disease: A Rare Cause of Stroke in Unexpected.

Moyamoya disease (MMD) is a chronic cerebrovascular occlusive disease that is characterized by progressive bilateral stenosis of the terminal portion of the internal carotid artery and its main branches. Cerebrovascular events are the primary presenting symptoms and are related both to stenosis and occlusion of the ICAs and their main branches. Detection of bilateral stenosis by cerebral angiography is considered the gold standard, but computed tomography angiography (CTA) is also an acceptable method of diagnosis. In the current literature, there are no precise data on the incidence of moyamoya disease in Europe and the United States. Also, the pathogenesis of MMD remains obscure, and genetic factors and inflammation are the two most representative mechanisms. Here, we report the case of MMD in a 29-year-old African American female who presented with an ischemic stroke for the second time that manifested after pregnancy. This case is important to increase awareness of the probability of this rare disease in Western countries as well as to call attention to pregnancy's accelerating effects of MMD. Careful, long-term neurologic and radiologic follow-up is essential in adult patients with MMD to prevent additional stroke events and improve outcomes.

A Minimally Invasive Endoscopic Technique for Fascia Lata Graft Acquisition and Fascial Reapproximation.

BACKGROUND: Fascia lata remains a popular and robust graft to repair osteodural defects in endoscopic neurosurgery. Classically, this graft is obtained via a large incision in the thigh that is prone to pain and muscle herniation after surgery. OBJECTIVE: To present a novel technique for harvesting fat and fascia lata graft and reapproximating the edges via an endoscopic approach through the thigh using an "outside-in" technique to prevent muscle herniation. METHODS: Initially our technique was performed in cadavers and includes the following: small 2 cm incision in the lateral thigh to accommodate the endoscope, use of blunt dissection and endoscopic tools to obtain the graft, and reapproximation of the fascia via an outside-in technique using conventional sutures with endoscopic visualization to retrieve the sutures beneath the skin and tie them. We then applied the technique to a patient undergoing transsphenoidal tumor resection. RESULTS: This technique was trialed in 3 cadaver specimens (6 limbs) and was used successfully in a patient with excellent cosmetic results seen in follow-up. CONCLUSION: Endoscopic retrieval of fascia lata is feasible via a very small incision. Reapproximation of the cut fascial edges to minimize muscle herniation can quickly and easily be performed with an outside-in technique detailed here. Additional case series may help to solidify the endoscopic retrieval as a preferred technique for fascia lata graft.

High-Definition Zoom Mode: A High Resolution X-ray Microscope for Neurointerventional Treatment Procedures.

BACKGROUND AND PURPOSE: Visualization of structural details of treatment devices during neurointerventional procedures can be challenging. A new true two-resolution imaging X-ray detector system features a 194 µm pixel conventional flat-panel detector (FPD) mode and a 76 µm pixel high-resolution high-definition (Hi-Def) zoom mode in one detector panel. The Hi-Def zoom mode was developed for use in interventional procedures requiring superior image quality over a small field of view (FOV). We report successful use of this imaging system during intracranial aneurysm treatment in 1 patient with a Pipeline-embolization device and 1 patient with a low-profile visualized intramural support (LVIS Blue) device plus adjunctive coiling. METHODS: A guide catheter was advanced from the femoral artery insertion site to the proximity of each lesion using standard FPD mode. Under magnified small FOV Hi-Def imaging mode, an intermediate catheter and microcatheters were guided to the treatment site, and the PED and LVIS Blue plus coils were deployed. Radiation doses were tracked intraprocedurally. RESULTS: Critical details, including structural changes in the PED and LVIS Blue and position and movement of the microcatheter tip within the coil mass, were more readily apparent in Hi-Def mode. Skin-dose mapping indicated that Hi-Def mode limited radiation exposure to the smaller FOV of the treatment area. CONCLUSIONS: Visualization of device structures was much improved in the high-resolution Hi-Def mode, leading to easier, more controlled deployment of stents and coils than conventional FPD mode.

Hemodynamics Associated With Intracerebral Arteriovenous Malformations: The Effects of Treatment Modalities.

The understanding of the physiology of cerebral arteriovenous malformations (AVMs) continues to expand. Knowledge of the hemodynamics of blood flow associated with AVMs is also progressing as imaging and treatment modalities advance. The authors present a comprehensive literature review that reveals the physical hemodynamics of AVMs, and the effect that various treatment modalities have on AVM hemodynamics and the surrounding cortex and vasculature. The authors discuss feeding arteries, flow through the nidus, venous outflow, and the relative effects of radiosurgical monotherapy, endovascular embolization alone, and combined microsurgical treatments. The hemodynamics associated with intracranial AVMs is complex and likely changes over time with changes in the physical morphology and angioarchitecture of the lesions. Hemodynamic change may be even more of a factor as it pertains to the vast array of single and multimodal treatment options available. An understanding of AVM hemodynamics associated with differing treatment modalities can affect treatment strategies and should be considered for optimal clinical outcomes.

What to do about fibrin rich 'tough clots'? Comparing the Solitaire stent retriever with a novel geometric clot extractor in an in vitro stroke model.

BACKGROUND: Despite advances in revascularization tools for large vessel occlusion presenting as acute ischemic stroke, a significant subset of clots remain recalcitrant to current strategies. We assessed the effectiveness of a novel thrombectomy device that was specifically designed to retrieve resistant fibrin rich clots, the geometric clot extractor (GCE; Neuravi, Galway, Ireland), in an in vitro cerebrovascular occlusion stroke model. METHODS: After introducing fibrin rich clot analogues into the middle cerebral artery of the model, we compared the rates of recanalization between GCE and Solitaire flow restoration stent retriever (SR; Medtronic, Minneapolis, Minnesota, USA; control group) cases. A maximum of three passes of each device was allowed. If the SR failed to recanalize the vessel after three passes, one pass of the GCE was allowed (rescue cases). RESULTS: In a total of 26 thrombectomy cases (13 GCE, 13 SR), successful recanalization (Thrombolysis in Cerebral Infarction score of 2b or 3) was achieved 100% of the time in the GCE cases with an average of 2.13 passes per case. This rate was significantly higher compared with the Solitaire recanalization rate (7.7%, P<0.0001) with an average of three passes per case. After SR failure (in 92% of cases), successful one pass GCE rescue recanalization was achieved 66% of the time (P<0.005). CONCLUSION: Application of the GCE in this experimental stroke model to retrieve typically recalcitrant fibrin rich clots resulted in higher successful recanalization rates than the SR.

Flow Diversion after Aneurysmal Subarachnoid Hemorrhage.

Flow diversion after aneurysmal subarachnoid hemorrhage (SAH) is the last treatment option for aneurysm occlusion when other methods of aneurysm treatment cannot be used because of the need for dual antiplatelet therapy. The authors' general protocol for treatment selection after aneurysmal SAH is provided to share with readers our approach to securing the aneurysm before embarking flow diversion for primary treatment or delayed adjunctive treatment to primary coiling. The authors' experience with flow diversion after aneurysmal SAH, review of pertinent literature, and the future of flow diversion after aneurysmal SAH are discussed.

Effective Surgical Management of Competitive Venous Outflow Restriction After Radiosurgery for Cerebral AVMs: Report of 2 Cases.

BACKGROUND: Intracranial arteriovenous malformations (AVMs) are complex pathologies. For patients who do not present with hemorrhage, treatment strategies are often predicated on reducing the risk of hemorrhage and minimizing morbidity. Outcomes vary according to the efficacy of treatment selected. Radiosurgical treatment of certain AVMs can result in incomplete obliteration and may also have only a minimal effect on the presenting nonhemorrhagic symptoms. CASE DESCRIPTIONS: We present 2 cases of patients with AVMs who were initially treated with radiosurgery. Both patients' primary clinical symptoms were headaches, which persisted after radiosurgical treatment but abated after subsequent microsurgical resection with or without endovascular embolization. CONCLUSION: Venous outflow obstruction is likely a sizable contributive factor in occipital AVMs among patients who present with headaches and symptoms of intracranial hypertension. Because these high-flow lesions may be suboptimally responsive to stereotactic radiosurgery, microsurgical resection, with or without adjunctive endovascular embolization, should be considered as an initial and definitive treatment strategy. Optimal outcomes may be achieved in patients with a visual deficit that is anatomically correlated to their AVMs.

Safety and outcomes of simultaneous vasospasm and endovascular aneurysm treatment (SVAT) in subarachnoid hemorrhage.

BACKGROUND: Simultaneous vasospasm and endovascular aneurysm treatment (SVAT) has been shown to be effective with good clinical outcomes in small series, but these studies have not examined predictive factors for clinical outcome after treatment. OBJECTIVE: To identify the safety and efficacy of SVAT in a large multicenter patient cohort and evaluate prognostic markers of clinical outcome following SVAT. METHODS: This study retrospectively enrolled 50 consecutive patients undergoing SVAT at 11 different centers. We analyzed Hunt and Hess and Fisher grades, aneurysm location, angiographic vasospasm grade, Glasgow Outcome Scale (GOS) at discharge, and 90-day modified Rankin Scale (mRS) scores. RESULTS: A total of 50 patients undergoing SVAT between the years 2003 and 2009 were identified. Patients presented, on average, 6.48±4.45 days after subarachnoid hemorrhage. Hunt and Hess and Fisher grades were 1 (n=7), 2 (n=12), 3 (n=14), 4 (n=15), 5 (n=2), and 3 and 4 (n=33), respectively. Aneurysm location was distributed as follows: anterior (n=32), posterior (n=16), anterior and posterior (n=2). Patients with good clinical condition (Hunt and Hess score 1-3) had significantly higher odds of surviving (OR=17.5, 95% CI 1.9 to 161.5), favorable GOS (OR=4.2, 95% CI 1.2 to 14.8), and favorable 90-day mRS (OR=4.2, 95% CI 1.2 to 14.8). CONCLUSIONS: SVAT is safe, with the majority of patients achieving good clinical outcome. Patients with lower Hunt and Hess grades have higher odds of surviving and favorable clinical prognosis.

Morbidity and mortality of patients with endovascularly treated intracerebral aneurysms: does physician specialty matter?

OBJECT Endovascular treatment of cerebrovascular pathology, particularly aneurysms, is becoming more prevalent. There is a wide variety in clinical background and training of physicians who treat cerebrovascular pathology through endovascular means. The impact of clinical training background on patient outcomes is not well documented. METHODS The authors conducted a retrospective analysis of a large national database, the University HealthSystem Consortium, that was queried in the years 2009-2013. Cases of both unruptured cerebral aneurysms and subarachnoid hemorrhage treated by endovascular obliteration were studied. Outcome measures of morbidity and mortality were evaluated according to the specialty of the treating physician. RESULTS Elective embolization of an unruptured aneurysm was the procedure code and primary diagnosis, respectively, for 12,400 cases. Patients with at least 1 complication were reported in 799 cases (6.4%). Deaths were reported in 193 cases (1.6%). Complications and deaths were varied by specialty; the highest incidence of complications (11.1%) and deaths (3.0%) were reported by neurologists. The fewest complications were reported by neurosurgeons (5.4%; 1.4% deaths), with a higher incidence of complications reported in cases performed by neurologists (p < 0.0001 for both complications and deaths) and to a lesser degree interventional radiologists (p = 0.0093 for complications). Subarachnoid hemorrhage was the primary diagnosis and procedure for 8197 cases. At least 1 complication was reported in 2385 cases (29%) and deaths in 983 cases (12%). The number of complications and deaths varied among specialties. The highest incidence of complications (34%) and deaths (13.5%) in subarachnoid hemorrhage was in cases performed by neurologists. The fewest complications were in cases by neurosurgeons (27%), with a higher incidence of complications in cases performed by neurologists (34%, p < 0.0001), and a trend of increased complications with interventional radiologists (30%, p < 0.0676). The lowest incidence of mortality was in cases performed by neurosurgeons (11.5%), with a significantly higher incidence of mortality in cases performed by neurologists (13.5%, p = 0.0372). Mortality rates did not reach statistical significance with respect to interventional radiologists (12.1%, p = 0.4884). CONCLUSIONS Physicians of varied training types and backgrounds use endovascular treatment of ruptured and unruptured intracerebral aneurysms. In this study there was a statistically significant finding that neurosurgically trained physicians may demonstrate improved outcomes with respect to endovascular treatment of unruptured aneurysms in this cohort. This finding warrants further investigation.

Biology of Saccular Cerebral Aneurysms: A Review of Current Understanding and Future Directions.

Understanding the biology of intracranial aneurysms is a clinical quandary. How these aneurysms form, progress, and rupture is poorly understood. Evidence indicates that well-established risk factors play a critical role, along with immunologic factors, in their development and clinical outcomes. Much of the expanding knowledge of the inception, progression, and rupture of intracranial aneurysms implicates inflammation as a critical mediator of aneurysm pathogenesis. Thus, therapeutic targets exploiting this arm of aneurysm pathogenesis have been implemented, often with promising outcomes.

Combined posterior hemiosteotomies and stabilization with lateral thoracotomy for en bloc resection of thoracic paraspinal primary bone tumors: technical note.

Primary bone tumors of the spine are rare entities with a poor prognosis if left untreated. En bloc excision is the preferred surgical approach to minimize the rate of recurrence. Paraspinal primary bone tumors are even less common. In this technical note the authors present an approach to the en bloc resection of primary bone tumors of the paraspinal thoracic region with posterior vertebral body hemiosteotomies and lateral thoracotomy. They also describe 2 illustrative cases.

Freehand thoracic pedicle screw technique using a uniform entry point and sagittal trajectory for all levels: preliminary clinical experience.

OBJECT: Experience with freehand thoracic pedicle screw placement is well described in the literature. Published techniques rely on various starting points and trajectories for each level or segment of the thoracic spine. Furthermore, few studies provide specific guidance on sagittal and axial trajectories. The goal of this study was to propose a uniform entry point and sagittal trajectory for all thoracic levels during freehand pedicle screw placement and determine the accuracy of this technique. METHODS: The authors retrospectively reviewed postoperative CT scans of 33 consecutive patients who underwent open, freehand thoracic pedicle-screw fixation using a uniform entry point and sagittal trajectory for all levels. The same entry point for each level was defined as a point 3 mm caudal to the junction of the transverse process and the lateral margin of the superior articulating process, and the sagittal trajectory was always orthogonal to the dorsal curvature of the spine at that level. The medial angulation (axial trajectory) was approximately 30° at T-1 and T-2, and 20° from T-3 to T-12. Breach was defined as greater than 25% of the screw diameter residing outside of the pedicle or vertebral body. RESULTS: A total of 219 thoracic pedicle screws were placed with a 96% accuracy rate. There were no medial breaches and 9 minor lateral breaches (4.1%). None of the screws had to be repositioned postoperatively, and there were no neurovascular complications associated with the breaches. CONCLUSIONS: It is feasible to place freehand thoracic pedicle screws using a uniform entry point and sagittal trajectory for all levels. The entry point does not have to be adjusted for each level as reported in existing studies, although this technique was not tested in severe scoliotic spines. While other techniques are effective and widely used, this particular method provides more specific parameters and may be easier to learn, teach, and adopt.