Influence of Patient and Technical Variables on Combined Direct and Indirect Cerebral Revascularization: Case Series

BACKGROUND

Cerebral bypass for flow augmentation is an important technique for selected neurosurgical patients, with multiple techniques used (direct, indirect, or combined).

OBJECTIVE

To assess the impact of patient and technical variables on direct and indirect bypass flow after combined revascularization.

METHODS

This was a retrospective, single-institution review of patients undergoing direct superficial temporal artery-to-middle cerebral artery bypass with indirect encephaloduro-myosynangiosis for moyamoya disease and steno-occlusive cerebrovascular disease over a 2-year period. We evaluated the effect of baseline patient characteristics, preoperative imaging characteristics, and operative variables on direct and indirect patency grades.

RESULTS

Twenty-six hemispheres (8 moyamoya disease and 18 steno-occlusive cerebrovascular disease) in 23 patients were treated with combined revascularization. The mean patient age was 53.4 ± 19.1 years. Direct bypass patency was 96%. Over a mean follow-up of 8.3 ± 5.4 months, there were 3 strokes in the treated hemispheres (11.5%). The mean modified Rankin Scale score improved from 1.3 ± 1.1 preoperatively to 0.7 ± 0.8 postoperatively. Preservation of the nondonor superficial temporal artery branch was associated with a lower direct bypass grade ( P < .01), whereas greater mean time to maximum perfusion (Tmax)> 4 and >6 seconds and mismatch volumes were associated with higher direct bypass grades ( P < .05). Tmax >4-second volume inversely predicted indirect bypass patency.

CONCLUSION

Patient and technical variables may influence the relative contributions of the direct and indirect components of combined revascularizations.

Vertebral Aneurysmal Bone Cyst Mimicking Osteosarcoma: Case Report and Review of the Literature

Aneurysmal bone cysts are benign osseous lesions containing blood-filled cavities separated by walls of connective tissue. They can be difficult to identify clinically due to similarities in presentation, imaging, and histology with other pathologies. Specifically, it is important to distinguish these benign lesions from malignant processes, as both surgical and medical management differ. We present the case of a 21-year-old patient who presented with impaired motor and sensory function in his lower extremities. Radiologic findings were concerning for an invasive neoplasm, and the intraoperative frozen section supported this conclusion. However, an additional histological investigation was confirmatory for a diagnosis of an aneurysmal bone cyst. The patient underwent corpectomy, laminectomy, and a posterior spinal fusion, and regained motor and sensory function shortly thereafter. This report details the importance of considering aneurysmal bone cysts in the differential of infiltrative bone lesions, despite their benign nature, as medical and surgical management can vary greatly.

Calcifying Pseudoneoplasm of the Neuraxis Presenting with Vasogenic Edema and a Perilesional Cyst

Calcifying pseudoneoplasms of the neuraxis (CAPNONs) are uncommon benign lesions that are rarely diagnosed radiographically. We report an unusual case of a left middle cerebellar peduncle CAPNON with vasogenic edema and a perilesional cyst. The patient was a 36-year-old woman with a 20-year history of left-sided hearing loss that had recently progressed. Computed tomography and magnetic resonance imaging showed a heterogenous calcified lesion with vasogenic edema and a perilesional cyst in the left middle cerebellar peduncle. Although it is a rare radiographic feature of CAPNON, vasogenic edema should be included as a possible feature of this uncommon tumefactive lesion.

Staged and Combined Approach for Resection of Giant Posterior Fossa and Temporal Bone Schwannoma

Vestibular schwannomas have an estimated incidence of 1.09/100,000 people, representing 6%-10% of intracranial tumors.^1-4 Rarer giant vestibular schwannomas are defined by an extrameatal diameter of ≥4 cm and can be difficult to treat because of displacement and compression of local neurovasculature and the potential for multicompartment involvement. A 20-year-old woman with history of presumed right-sided Bell palsy and unexplained hearing loss was found to have a 9 × 8 × 6-cm giant posterior fossa schwannoma on syncopal workup (Video 1). It extended from the Meckel cave anterosuperiorly to below the skull base through the jugular foramen, filling the petrous apex and compressing the cerebellum, pons, and midbrain. She had ipsilateral facial weakness (House-Brackmann 3/5), V2 numbness, tongue deviation, vocal fold paresis, and hearing loss. A combined petrosal (transotic, extended middle fossa) and retrosigmoid approach was performed through a curvilineal incision that provided access to the middle fossa, petrous apex, and posterior fossa down to the jugular foramen and included a trajectory along the long axis of the tumor (retrosigmoid). Although we hypothesize this was a vestibular schwannoma, it was difficult to ascertain the exact origin of the tumor because of its massive size. Surgery was performed in 2 stages because of the large tumor size and to limit blood loss. A gross total resection was achieved. Closure included an autologous fat and synthetic cranioplasty. The patient was neurologically stable postoperatively, except for transient swallowing difficulty due to partial cranial nerve IX/X palsies. This case illustrates important considerations when combining surgical approaches for complex tumors involving multiple intracranial compartments.

Laminectomy at T4 and T5 for Resection of Symptomatic Cavernous Malformation

Although rare, intramedullary spinal cavernous malformations have a 1.4%-6.8% annual hemorrhage risk and can cause significant morbidity.¹ Prior hemorrhage and size >1 cm are risk factors for future hemorrhage that, in addition to notable or progressive symptoms, may justify early surgical intervention.^1,2 In this video, we present key steps in surgical management of a large, symptomatic thoracic cavernous malformation. A 56-year-old woman presented with worsening lower extremity weakness, imbalance, and difficulty ambulating. Strength was 3/5 in her right lower extremity and 4/5 in her left lower extremity. She had an incomplete T4 sensory level and hyperreflexia. Magnetic resonance imaging demonstrated a heterogeneous "popcorn"-appearing expansile intradural intramedullary 2.2- × 1.2-cm lesion at T4-5, consistent with a cavernous malformation. Angiography was deferred given the characteristic magnetic resonance imaging appearance. Given her progressive symptoms (including weakness), lesion size, and good health, resection was recommended. Using neurological monitoring, a T4-5 laminectomy, midline myelotomy, and piecemeal microsurgical resection of the lesion was performed, clearly identifying the cavernoma-spinal cord interface and avoiding spinal cord retraction. Histopathology confirmed a cavernoma. Postoperatively, the patient had improved left lower extremity strength and stable right lower extremity strength but worsened dorsiflexion (1/5), which improved with rehabilitation. At 1-year follow-up, she had full strength in her left lower extremity and 4/5 in her right lower extremity, with mild paresthesias below T10. Consistent with prior series demonstrating low complication rates and good long-term neurological outcomes,² microsurgical resection of selected symptomatic intramedullary spinal cavernous malformations can halt neurological decline and potentially improve neurological function.

Cranio-Orbital Approach for Single-Stage En Bloc Resection of Optic Nerve Glioma: Technical Note

BACKGROUND AND IMPORTANCE

There is no consensus on the optimal surgical approach for managing optic nerve gliomas. For solely intraorbital tumors, a single-stage lateral orbitotomy approach for resection may be performed, but when the nerve within the optic canal is affected, two-stage cranial and orbital approaches are often used. The authors describe their technique to safely achieve aggressive nerve resection to minimize the probability of recurrence that might affect the optic tracts, optic chiasm, and contralateral optic nerve.

CLINICAL PRESENTATION

A 28-yr-old woman presented with painless progressive vision loss, resulting in blindness. The second of 2 transorbital biopsies was diagnostic and consistent with low-grade glioma. The lesion continued to grow on serial imaging. The patient was offered a globe-sparing operative approach, with aggressive resection of the lesion to minimize the probability of tumor recurrence, which could possibly affect vision in her contralateral eye. The patient did well postoperatively, with clean tumor margins on pathological analysis and no evidence of residual on imaging. On postoperative examination, she had a mild ptosis, which was nearly resolved at her 6-wk outpatient follow-up.

CONCLUSION

This aggressive single-stage en bloc resection of an optic nerve glioma can achieve excellent tumor margins and preservation of extraocular muscle function.

Microsurgical Excision of Ruptured Lenticulostriate Artery Aneurysm

Lenticulostriate artery aneurysms are uncommon lesions, usually found in adults after hemorrhage. Despite their challenging location, mortality rates after initial hemorrhage are favorable. Securing the hemorrhage source is critical but may be complicated by lesional compression or thrombosis on posthemorrhage vascular imaging. We present key steps in the diagnosis and surgical management of a ruptured lenticulostriate aneurysm (Video 1). A healthy 18-year-old patient with prior intermittent prescription amphetamine use presented after acute severe headache onset while weight lifting. On examination, he had trace left upper extremity drift and weakness but was otherwise neurologically intact. A head computed tomography demonstrated a 2.9 × 2.6 × 1.7-cm right basal ganglia intraparenchymal hemorrhage, with trace subarachnoid hemorrhage in the basal cisterns. Secondary imaging including magnetic resonance imaging, computed tomography angiogram, and digital subtraction angiogram was negative for underlying lesions. After an uneventful recovery, a 4-month magnetic resonance angiogram and subsequent digital subtraction angiography demonstrated a 2.7-mm right lenticulostriate aneurysm in the area of the prior hemorrhage. Treatment was recommended to prevent a rehemorrhage, with the safety of local vessel sacrifice presumed based on prior local tissue damage. Microcatheterization was unsuccessful. A right frontotemporal craniotomy for transsylvian, transinsular microsurgical aneurysm excision was performed, with image guidance used for the insular entry site. The patient was discharged home neurologically intact on postoperative day 2. At 1-year follow-up, there were no new or recurrent vascular lesions on imaging. Delayed imaging is critical to identify initially occult cerebrovascular lesions after hemorrhage. The transsylvian, transinsular approach provides safe access to the basal ganglia region in selected patients.

Idiopathic chronic temporal lobe herniation with associated epilepsy

Herniation of parahippocampal gyrus is usually caused by pressure differentials intracranially, and herniation without known risk factors is extremely rare. We describe a patient with a long history of seizures and a remote status epilepticus event. On magnetic resonance imaging, a presumed left temporal lobe tumor was observed. On neurosurgical consultation, the lesion was identified as a chronic mesial temporal lobe herniation. The patient lacked history that would suggest risk of cerebral herniation. Accurately identifying the patient's chronic temporal lobe herniation radiographically likely saved this patient from unnecessary surgery or biopsy and allowed the patient to receive appropriate conservative care.

Propensity-Adjusted Comparative Analysis of Radial Versus Femoral Access for Neurointerventional Treatments

BACKGROUND

Transradial artery (TRA) catheterization for neuroendovascular procedures is associated with a lower risk of complications than transfemoral artery (TFA) procedures. However, the majority of literature on TRA access pertains to diagnostic procedures rather than interventional treatments.

OBJECTIVE

To compare TRA and TFA approaches for cerebrovascular interventions.

METHODS

All patients with an endovascular intervention performed at a single center from October 1, 2018 to December 31, 2019 were retrospectively analyzed. Patients were grouped into 2 cohorts on the basis of whether TRA or TFA access was used. Outcomes included complications, fluoroscopy times, and total contrast administered.

RESULTS

A total 579 interventional treatments were performed during the 15-mo study period. TFA procedures (n = 417) were associated with a significantly higher complication rate than TRA (n = 162) procedures (43 cases [10%] vs 5 cases [3%]; P = .008). After excluding patients who underwent thrombectomy and performing a propensity adjustment (including age, sex, pathology, procedure, sheath size, and catheter size), TRA catheterization was associated with decreased odds of a complication (odds ratio, 0.25; 95% CI 0.085-0.72; P = .01), but no significant difference in the amount of contrast administered (6.7-mL increase; 95% CI, -7.2 to 20.6; P = .34) or duration of fluoroscopy (2.1-min increase; 95% CI, -2.5 to 6.7; P = .37) compared with TFA catheterization.

CONCLUSION

Neurointerventional procedures and treatments for a variety of pathologies can be performed successfully using the TRA approach, which is associated with a lower risk of complications and no difference in fluoroscopy duration compared with the TFA approach.

Lateral Suboccipital Craniotomy With C1-C2 Hemilaminectomies and C1-C3 Fusion for the Treatment of a C1-C2 Synovial Cyst Causing Spinal Cord Compression: 2-Dimensional Operative Video

Atlantoaxial synovial cysts are a rare cause of cervical myelopathy. Here we describe a case of a 26-yr-old woman who presented with progressively decreasing right arm and leg strength and associated gait imbalance. On examination, she had diffuse weakness in the right upper and lower extremities, a positive right-sided Hoffman sign, and clonus in the right lower extremity. Computed tomography demonstrated an os odontoideum and a retro-odontoid cyst. Magnetic resonance imaging demonstrated a T1 hypointense, T2 hyperintense, slightly rim-enhancing retro-odontoid cyst causing a marked narrowing of the spinal canal, with resultant flattening and leftward deviation of the spinal cord. The patient consented to undergo cyst fenestration via a right suboccipital craniotomy and right C1-C2 hemilaminectomies, along with a C1-C3 instrumented posterior spinal fusion. This approach was chosen because it allows for cyst fenestration and instrumentation of the hypermobile cervical spine within the same incision. After the dura was opened and the arachnoid was dissected, the cyst was visualized compressing the spinal cord. The cyst was fenestrated just inferior to the C1 nerve rootlets, resulting in immediate egress of a gelatinous content; thereafter, all accessible cyst wall portions were removed. Fusion was performed with lateral mass screws at C1 and C3 and pars screws at C2. Pathological analysis described the cyst content as reactive fibrovascular tissue with cholesterol deposition. There were no complications associated with the procedure, and the patient's right-sided weakness had nearly resolved by postoperative day 1. Patient consent was granted for publication.

Transradial cerebral angiography becomes more efficient than transfemoral angiography: lessons from 500 consecutive angiograms

BACKGROUND

Transradial arterial access (TRA) for cerebral diagnostic angiography is associated with fewer access site complications than transfemoral access (TFA). However, concerns about increased procedure time and radiation exposure with TRA may slow its adoption. Our objective was to measure TRA rates of success and fluoroscopy time per vessel after 'radial-first' adoption and to compare these rates to those obtained with TFA.

METHODS

We examined 500 consecutive cerebral angiograms on an intent-to-treat basis during the first full year of radial-first adoption, recording patient and procedural characteristics and outcomes.

RESULTS

Over a 9-month period at a single center, 457 of 500 angiograms (91.4%) were performed with intent-to-treat via TRA, and 431 cases (86.2%) were ultimately performed via TRA. One patient (0.2%) experienced a temporary neurologic deficit in the TRA group, and none (0%) did in the TFA group (p=0.80). The mean±SD fluoroscopy time per vessel decreased significantly from the first half of the study to the second half for TRA (5.0±3.8 vs 3.4±3.5 min/vessel; p<0.001), while TFA time remained unchanged (3.7±1.8 vs 3.5±1.4 min/vessel; p=0.69). The median fluoroscopy time per vessel for TRA became faster than that for TFA after 150 angiograms.

CONCLUSION

Of 500 consecutive angiograms performed during the first full year of radial-first implementation, 86.2% were performed successfully using TRA. TRA efficiency exceeded that of TFA after 150 angiograms. Concerns about the length of procedure or radiation exposure should not be barriers to TRA adoption.

Omeprazole-clopidogrel interaction and neurovascular complications after flow-diverter device placement

BACKGROUND

Omeprazole is a common proton pump inhibitor that interferes with the hepatic activation of clopidogrel and potentially reduces its platelet-inhibitory effect. Omeprazole has been shown to increase P2Y₁₂ levels and adverse cardiovascular outcomes in patients treated with drug-eluting stents. However, omeprazole use among patients treated with flow-diverting stents for intracranial aneurysms has not been evaluated.

METHODS

All patients with placement of a flow-diverting device for treatment of an intracranial aneurysm at a tertiary institution from January 1, 2014, to December 31, 2018, were retrospectively analyzed. Inclusion criteria included documented clopidogrel administration, available P2Y₁₂ levels, and thorough documentation of administration of other medications, including omeprazole.

RESULTS

A total of 138 patients met the inclusion criteria. Sixteen patients (12%) were receiving omeprazole and clopidogrel at treatment. P2Y₁₂ reactivity was significantly greater in the omeprazole cohort (mean P2Y₁₂ level, 250 P2Y₁₂ reaction units (PRU)) than in the control cohort (mean P2Y₁₂ level, 112PRU) (P<0.001). Furthermore, a greater proportion of patients had a P2Y₁₂ level >180 PRU in the omeprazole cohort (14 of 16 [88%] vs 24 of 122 [20%]; P<0.001; OR [95% CI], 29 [6-134]).

CONCLUSION

Omeprazole was associated with a significant increase in the mean P2Y₁₂ reactivity level among patients with intracranial aneurysms treated with flow-diverting devices who received clopidogrel. However, receipt of omeprazole was not associated with an increased risk of ischemic events or stent stenosis. For neuroendovascular patients who are treated with a flow diverter while receiving clopidogrel, alternative gastrointestinal medication regimens should be considered.

Endovascular treatment of vertebral artery dissecting aneurysms : a 20-year institutional experience

BACKGROUND

The ideal treatment for unruptured vertebral artery dissecting aneurysms (VADAs) and ruptured dominant VADAs remains controversial. We report our experience in the management and endovascular treatment of patients with VADAs.

METHODS

Patients treated endovascularly for intradural VADAs at a single institution from January 1, 1999, to December 31, 2019, were retrospectively reviewed. Primary neurological outcomes were assessed using modified Rankin Scale (mRS) scores, with mRS >2 considered a poor neurological outcome. Additionally, any worsening (increase) in the mRS score from the preoperative neurological examination was considered a poor outcome.

RESULTS

Ninety-one patients of mean (SD) age 53 (11.6) years (48 (53%) men) underwent endovascular treatment for VADAs. Fifty-four patients (59%) presented with ruptured VADAs and 44 VADAs (48%) involved the dominant vertebral artery. Forty-seven patients (51%) were treated with vessel sacrifice of the parent artery, 29 (32%) with flow diversion devices (FDDs), and 15 (17%) with stent-assisted coil embolization (stent/coil). Rates of procedural complications and retreatment were significantly higher with stent/coil treatment (complications 4/15; retreatment 6/15) than with vessel sacrifice (complications 1/47; retreatment 2/47) or FDD (complications 2/29; retreatment 4/29) (p=0.008 and p=0.002, respectively). Of 37 patients with unruptured VADAs treated, only two (5%) had mRS scores >2 on follow-up.

CONCLUSION

Endovascular FDD treatment of VADAs appears to be associated with lower retreatment and complication rates than stenting/coiling, although further study is required for confirmation. Endovascular treatment of unruptured VADAs was safe and was associated with favorable angiographic and neurological outcomes.

A propensity-adjusted comparison of middle meningeal artery embolization versus conventional therapy for chronic subdural hematomas

OBJECTIVE

Middle meningeal artery (MMA) embolization is a promising treatment strategy for chronic subdural hematomas (cSDHs). However, studies comparing MMA embolization and conventional therapy (surgical intervention and conservative management) are limited. The authors aimed to compare MMA embolization versus conventional therapy for cSDHs using a propensity-adjusted analysis.

METHODS

A retrospective study of all patients with cSDH who presented to a large tertiary center over a 2-year period was performed. MMA embolization was compared with surgical intervention and conservative management. Neurological outcome was assessed using the modified Rankin Scale (mRS). A propensity-adjusted analysis compared MMA embolization versus surgery and conservative management for all individual cSDHs. Primary outcomes included change in hematoma diameter, treatment failure, and complete resolution at last follow-up.

RESULTS

A total of 231 patients with cSDH met the inclusion criteria. Of these, 35 (15%) were treated using MMA embolization, and 196 (85%) were treated with conventional treatment. On the latest follow-up, there were no statistically significant differences between groups in the percentage of patients with worsening mRS scores. Of the 323 total cSDHs found in 231 patients, 41 (13%) were treated with MMA embolization, 159 (49%) were treated conservatively, and 123 (38%) were treated with surgical evacuation. After propensity adjustment, both surgery (OR 12, 95% CI 1.5-90; p = 0.02) and conservative therapy (OR 13, 95% CI 1.7-99; p = 0.01) were predictors of treatment failure and incomplete resolution on follow-up imaging (OR 6.1, 95% CI 2.8-13; p < 0.001 and OR 5.4, 95% CI 2.5-12; p < 0.001, respectively) when compared with MMA embolization. Additionally, MMA embolization was associated with a significant decrease in cSDH diameter on follow-up relative to conservative management (mean -8.3 mm, 95% CI -10.4 to -6.3 mm, p < 0.001).

CONCLUSIONS

This propensity-adjusted analysis suggests that MMA embolization for cSDH is associated with a greater extent of hematoma volume reduction with fewer treatment failures than conventional therapy.

An Expedited Transition to the Back Wall Suturing for Side-to-Side In Situ Microvascular Anastomosis: A Technique Update

BACKGROUND

The side-to-side in situ microvascular anastomosis is an important tool in the cerebrovascular neurosurgeon's armamentarium. The execution of the side-to-side anastomosis, however, can be limited by the inability to acquire sufficient visualization and approximation of the recipient and donor vessels.

OBJECTIVE

To expedite the transition to the back wall suturing of the donor and recipient vessels during side-to-side in situ microvascular anastomosis.

METHODS

Incorporation of the first suture throw from the outside to the inside of the vessel lumen with the initial stay suture at the proximal apex of the arteriotomy is described. The apical knot is tied between one limb of the resultant loop and the free end of the suture. The remainder of side-to-side anastomosis can then be completed in a standard fashion starting from the inside of the lumen.

RESULTS

This modification allows for an expedited transition to the back wall suturing of the 2 arterial segments and avoids difficulties associated with taking the first bite from behind the knot at the proximal apex of the arteriotomy or the transfer of the needle between the approximated vessels. This updated technique is illustrated with a case example, illustration, and video.

CONCLUSION

This technical modification for the side-to-side anastomosis helps optimize microsurgical efficiency by limiting needle, suture, and vessel handling after the initial suture placement, which has classically been a challenge of this bypass.

Middle meningeal artery embolization for chronic subdural hematoma: an institutional technical analysis

BACKGROUND

Recently, middle meningeal artery (MMA) embolization has emerged as a potentially safe and effective method of treating chronic subdural hematoma (cSDH).

OBJECTIVE

To report a single-center experience with MMA embolization and examines the type of embolic material used, the extent of penetration, and the number of MMA branches embolized.

METHODS

A retrospective analysis of all patients with MMA embolization from 2018 through 2019 was performed. A failed outcome was defined as either surgical rescue and/or greater than 10 mm of hematoma residual or reaccumulation following embolization.

RESULTS

Of 35 patients, surgery had failed for 9 (26%) and initial conservative treatment had failed for 6 (17%). Of 41 MMA embolizations, including those in six patients with bilateral cSDH who underwent bilateral MMA embolization, 29 (72%) were performed using ethylene vinyl alcohol copolymer (Onyx), 7 (17%) using particles, and 5 (12%) using n-butyl cyanoacrylate. Both the anterior and posterior MMA divisions were embolized in 29 cases (71%); distal penetration of these branches was achieved in 25 embolizations (61%). Twenty-six (63%) cSDHs completely resolved. Complete resolution was seen in 22 of 29 hematomas (76%) in which both anterior and posterior MMA branches were occluded versus 4 of 12 (33%) following single-branch embolization (p=0.014). Embolization of one cSDH (2%) failed.

CONCLUSION

MMA embolization of cSDHs appears to be both safe and efficacious. Furthermore, embolization of both the anterior and posterior MMA branches may be associated with increased odds of complete resolution.

Comparison of aspiration-first versus stentriever-first techniques in performing mechanical thrombectomy for large vessel occlusions

BACKGROUND

Both stentriever and direct-aspiration thrombectomy effectively treat large-vessel occlusions. However, data are limited comparing clinical outcomes after aspiration-first versus stentriever-assisted aspiration for thrombectomy.

METHODS

A retrospective cohort study compared procedure times and radiographic outcomes after two mechanical thrombectomy techniques (aspiration first or stentriever). To minimize bias and variability inherent to multi-operator series, we assessed consecutive patients with cerebrovascular occlusions treated by a single surgeon during a 1 year period at two stroke centers. Expanded Thrombolysis in Cerebral Infarction (eTICI) grades were assessed by an investigator blinded to treatment.

RESULTS

Data from 93 patients (median age 70 years) were analyzed: 73 patients (78.5%) were treated with a strentriever-first strategy and 20 (21.5%) were treated with aspiration first, with stentriever rescue therapy required in only three of these cases following unsuccessful aspiration. There were no significant differences in patient demographics, sites of occlusion, or rates of tandem occlusions between aspiration-first and stentriever-assisted groups (p≥0.36). The rate of first-pass eTICI ≥2b was 75.0% (15/20) for aspiration-first and 52.1% (38/73) for strentriever-first groups (p=0.07), while the rate of final eTICI ≥2b was 100% (20/20) and 82.2% (60/72), respectively (p=0.04). The aspiration-first technique was associated with procedural times ≤25 min in a multivariable analysis (adjusted OR 4.77, 95% CI 1.15 to 18.39; p=0.03).

CONCLUSIONS

In this single-surgeon series, an aspiration-first technique was associated with a statistically significant improvement in eTICI outcomes and faster procedure times compared with stentriever-assisted aspiration. Further prospective studies are necessary to minimize selection bias inherent in this study design.

Reimplantation Bypass Using One Limb of a Double-Origin Posterior Inferior Cerebellar Artery for Treatment of a Ruptured Fusiform Aneurysm: Case Report

BACKGROUND AND IMPORTANCE

Posterior inferior cerebellar artery (PICA) aneurysms are uncommon, and aneurysms associated with anatomical PICA variants are even rarer. Although often treated endovascularly, aneurysms associated with anatomical PICA variants may not be suitable for endovascular intervention because of the risk of compromise of brainstem perforators and may be more amenable to open techniques. This case report describes the successful treatment of an aneurysm associated with a double-origin PICA (DOPICA) by distally reimplanting one of the PICA limbs.

CLINICAL PRESENTATION

A 78-yr-old man with a Hunt-Hess grade III, Fisher grade IV subarachnoid hemorrhage secondary to a ruptured distal right PICA aneurysm associated with a DOPICA was treated with PICA-PICA bypass and trapping of the aneurysm. This is the first reported case in the literature of successful bypass of a DOPICA-associated aneurysm. Radiographically, the bypass remained patent with successful obliteration of the aneurysm, and at discharge from the hospital, the patient had a Glasgow Coma Scale score of 15 and modified Rankin Scale score of 3.

CONCLUSION

This case demonstrates a novel reimplantation bypass for a ruptured aneurysm that exploits this rare variant anatomy of a DOPICA.

Outcomes in a Case Series of Elderly Patients with Aneurysmal Subarachnoid Hemorrhages in the Barrow Ruptured Aneurysm Trial (BRAT)

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is debilitating in elderly patients, but literature regarding this population is scarce, and clinical decision-making remains debated. Outcomes of elderly patients with aSAH stratified by age and clinical presentation were analyzed.

METHODS

Patients treated for aSAH were retrospectively analyzed. Patients were trichotomized into a young cohort (aged <60 years [n = 268]) and 2 elderly cohorts (aged 60-65 years [n = 60] and ≥65 years [n = 77]). The elderly cohorts were analyzed by poor or good scores at presentation (Hunt and Hess [HH] score >3 vs. ≤3, respectively) and poor functional outcome (modified Rankin Scale score >2).

RESULTS

Of 137 elderly patients, 121 had a 6-year follow-up. The >65-year-olds (75% [52/69]) were more likely to have poor functional outcomes than the 60 to 65-year-olds (48% [25/52]) (odds ratio, 3.3; 95% confidence interval, 1.5-7.1; P = 0.002). Among those with an HH score ≤3 at presentation (n = 90), the >65-year-old cohort had poorer outcomes than the 60 to 65-year-old cohort at 6-year follow-up (69% [35/51] vs. 36% [14/39], respectively; odds ratio, 3.9; 95% confidence interval, 1.6-9.4; P = 0.003). Among patients with an HH score >3, no statistically significant differences in functional outcome were observed between the >65-year-old (n = 18) and 60 to 65-year-old (n = 13) cohorts.

CONCLUSIONS

Elderly patients with aSAH are at high risk for poor functional outcomes. However, among those presenting with good HH scores, younger-elderly patients (aged 60-65 years) tend to fare better than older-elderly patients (aged >65 years). Elderly patients presenting with high-grade aSAH fare poorly regardless of age, which can inform clinical decision-making and prognostication.

Postembolization Change in Magnetic Resonance Imaging Contrast Enhancement of Meningiomas Is a Better Predictor of Intraoperative Blood Loss Than Angiography

BACKGROUND

Preoperative embolization of meningiomas to reduce tumor vascularity and intraoperative blood loss remains controversial. Incomplete devascularization on angiography is not significantly correlated with intraoperative estimated blood loss (EBL). Magnetic resonance imaging (MRI) may provide a better assessment of devascularization and prediction of EBL.

METHODS

We retrospectively analyzed patients undergoing preoperative embolization for intracranial meningiomas. Cohorts based on postembolization devascularization (>50% vs. ≤50%) were compared.

RESULTS

Of 84 patients with meningioma undergoing preoperative embolization, 35 (42%) had a postembolization MRI before resection and met study inclusion criteria. The mean tumor diameter was 4.9 ± 1.3 cm, and mean intraoperative EBL was 576 ± 341 mL. Compared with MRI, angiography overestimated devascularization in 22 patients (63%). Using pre- versus postembolization MRIs, 17 (49%) patients had a >50% decrease in enhancement, which was associated with lower mean intraoperative blood loss (444 ± 255 mL) compared with 17 patients with ≤50% devascularization (700 ± 374 mL) (P = 0.03). On angiography, the 22 (63%) patients who demonstrated >50% devascularization during embolization did not statistically differ in intraoperative EBL when compared with 13 (37%) patients with <50% angiographic devascularization. Patients with a ≤50% decrease in contrast enhancement on postembolization MRI were 9 times more likely to lose >500 mL blood intraoperatively during resection (95% confidence interval 1.6-54, P = 0.01).

CONCLUSIONS

Postembolization contrast-enhanced MRI is a better predictor of intraoperative blood loss during meningioma resection than postembolization angiography, which overestimates the degree of embolic devascularization. Postembolization preoperative MRI is warranted for optimal patient management.

Complications of femoral versus radial access in neuroendovascular procedures with propensity adjustment

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

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.

Digital subtraction cerebral angiography after negative computed tomography angiography findings in non-traumatic subarachnoid hemorrhage

Background

CT angiography (CTA) is widely used for the detection of vascular lesions in patients with non-traumatic subarachnoid hemorrhage (ntSAH); however, digital subtraction angiography (DSA) remains the gold standard for diagnosis. Our aim was to analyze the diagnostic yield of DSA after negative high-resolution CTA findings.

Methods

Records of patients with a CTA-negative ntSAH at a single institution from 2014 to 2018 were retrospectively analyzed. ntSAH patterns were categorized as cortical, perimesencephalic, or diffuse. Subsequent DSA findings were compared across the three cohorts.

Results

A total of 186 patients had CTA-negative ntSAH. The ntSAH pattern was identified as cortical (n=77, 41.4%), diffuse (n=60, 32.3%), or perimesencephalic (n=49, 26.3%). In eight patients (4%), DSA revealed a vascular lesion (one cervical arteriovenous fistula and seven atypical aneurysms) after negative CTA findings. All eight patients with positive DSA findings had diffuse SAH (13% of patients with a diffuse pattern). The seven aneurysms included four blister or dissecting (two basilar artery, one superior cerebellar artery, and one dorsal wall internal carotid artery), two fusiform (one posterior communicating artery and one anterior spinal artery), and one saccular aneurysm (middle cerebral artery).

Conclusion

DSA identified a causative lesion in 4% of patients with CTA-negative ntSAH, but only in patients with diffuse ntSAH. Most of the lesions detected were atypical aneurysms and were found on delayed angiograms. These results suggest that DSA can help to diagnose CTA-negative ntSAH caused by unusual aneurysms, and repeat DSA may be needed only for patients with diffuse ntSAH.

Long-term surgical outcomes following transsphenoidal surgery in patients with Rathke's cleft cysts

OBJECTIVE

Rathke's cleft cysts (RCCs) are benign epithelial lesions of the sellar region typically treated via a transsphenoidal approach with cyst fenestration and drainage. At present, there is limited evidence to guide patient selection for operative treatment. Furthermore, there is minimal literature describing factors contributing to cyst recurrence.

METHODS

The authors conducted a retrospective analysis of 109 consecutive cases of pathology-confirmed RCCs treated via a transsphenoidal approach at a single center from 1995 to 2016. The majority of cases (86.2%) involved cyst fenestration, drainage, and partial wall resection. Long-term outcomes were analyzed.

RESULTS

A total of 109 surgeries in 100 patients were included, with a mean follow-up duration of 67 months (range 3-220 months). The mean patient age was 44.6 years (range 12-82 years), and 73% were women. The mean maximal cyst diameter was 14.7 mm. Eighty-eight cases (80.7%) were primary operations, and 21 (19.3%) were reoperations. Intraoperative CSF leak repair was performed in 53% of cases and was more common in reoperation cases (71% vs 48%, p < 0.001). There were no new neurological deficits or perioperative deaths. Two patients (1.8%) developed postoperative CSF leaks. Transient diabetes insipidus (DI) developed in 24 cases (22%) and permanent DI developed in 6 (5.5%). Seven cases (6.4%) developed delayed postoperative hyponatremia. Of the 66 patients with preoperative headache, 27 (44.3%) of 61 reported postoperative improvement and 31 (50.8%) reported no change. Of 31 patients with preoperative vision loss, 13 (48.1%) reported subjective improvement and 12 (44.4%) reported unchanged vision. Initial postoperative MRI showed a residual cyst in 25% of cases and no evidence of RCC in 75% of cases. Imaging revealed evidence of RCC recurrence or progression in 29 cases (26.6%), with an average latency of 28.8 months. Of these, only 10 (9.2% of the total 109 cases) were symptomatic and underwent reoperation.

CONCLUSIONS

Transsphenoidal fenestration and drainage of RCCs is a safe and effective intervention for symptomatic lesions, with many patients experiencing improvement of headaches and vision. RCCs show an appreciable (although usually asymptomatic) recurrence rate, thereby mandating serial follow-up. Despite this, full RCC excision is typically not recommended due to risk of hypopituitarism, DI, and CSF leaks.

Selective posterior cerebral artery amobarbital test: a predictor of memory following subtemporal selective amygdalohippocampectomy

BACKGROUND

The selective posterior cerebral artery (PCA) amobarbital test, or PCA Wada test, is used to predict memory impairment after epilepsy surgery in patients who have previously had a failed internal carotid artery (ICA) amobarbital test.

METHODS

Medical records from 2012 to 2018 were retrospectively reviewed for all patients with seizures who underwent a selective PCA Wada test at our institution following a failed or inconclusive ICA Wada test. Standardized neuropsychological testing was performed before and during the Wada procedure and postoperatively in patients who underwent resection.

RESULTS

Thirty-three patients underwent a selective PCA Wada test, with no complications. Twenty-six patients with medically refractory epilepsy had a seizure focus amenable to selective amygdalohippocampectomy (AHE). Six patients (23%, n=26) had a failed PCA Wada test and did not undergo selective AHE, seven (27%) declined surgical resection, leaving 13 patients who underwent subtemporal selective AHE. Hippocampal sclerosis was found in all 13 patients (100%). Twelve patients (92%) subsequently underwent formal neuropsychological testing and all were found to have stable memory. Ten patients (77%) were seizure-free (Engel Class I), with average follow-up of 13 months.

CONCLUSION

The selective PCA Wada test is predictive of memory outcomes after subtemporal selective AHE in patients with a failed or inconclusive ICA Wada test. Furthermore, given the low risk of complications and potential benefit of seizure freedom, a selective PCA Wada test may be warranted in patients with medically intractable epilepsy who are candidates for a selective AHE and who have a prior failed or inconclusive ICA Wada test.

Flow diverters as a scaffold for treating direct carotid cavernous fistulas

Background

Direct carotid–cavernous sinus fistulas (dCCFs) are high flow arteriovenous shunts between the internal carotid artery and the cavernous sinus. Recently, we have used the pipeline embolization device (PED) to treat dCCFs.

Methods

We describe our experience treating patients with dCCFs in whom the PED was placed as the primary treatment modality.

Results

Five patients with dCCFs were treated with PEDs deployed in the ipsilateral internal carotid artery spanning the fistula. All patients also underwent either adjunctive transvenous or transarterial embolization. The PED served both as the primary treatment modality and as a scaffold that facilitated safe and efficacious transvenous embolysate administration by altering the flow dynamics through the fistula and providing a physical barrier that protected the internal carotid artery. No intraoperative or perioperative complications occurred. One of the five patients exhibited complete angiographic resolution of the fistula immediately after the procedure. The remaining four patients experienced complete obliteration of the fistula without additional treatment, which suggests that the PED induced alteration promoted thrombosis of the fistula. Therefore, 100% of patients in this series exhibited complete and durable obliteration of the fistula and complete resolution of symptoms following treatment.

Conclusions

We believe that use of the PED to treat dCCFs may be a safe and efficacious strategy that facilitates parent vessel protection during transvenous embolization. Furthermore, the flow alterations induced by the PED may promote thrombosis of incompletely occluded fistulas. This is the largest reported series of non-iatrogenic dCCFs treated with use of the PED as the primary initial treatment strategy.

Recurrent Rathke's Cleft Cysts: Incidence and Surgical Management in a Tertiary Pituitary Center over 2 Decades

BACKGROUND

Limited data exist pertaining to outcomes following surgery for recurrent Rathke's cleft cysts (RCC).

OBJECTIVE

To determine treatment outcomes in patients undergoing reoperation for recurrent or residual RCCs.

METHODS

A retrospective analysis of 112 consecutive RCC operations in 109 patients between 1995 and 2017 was conducted.

RESULTS

Eighteen patients underwent 21 RCC reoperations with a mean follow-up of 58 mo. Patient symptoms prior to reoperation included headaches (14, 66.7%) and vision loss (12, 57.1%). Thirteen of 18 patients (72.2%) required hormone supplementation prior to reoperation including 5 with diabetes insipidus (DI). Mean RCC diameter was 16 mm and 76% had suprasellar extension. Compared to index RCC cases, intraoperative cerebrospinal fluid leak repair was more common in reoperation cases (15/21, 71% vs 43/91, 47%, P = .05). There was 1 carotid artery injury without neurological sequelae, and 2 postoperative cerebrospinal fluid (CSF) leaks (9.5%). Rates of transient hyponatremia (3/10, 30% vs 4/91, 4.4%, P = .04) and transient DI (5/10, 50% vs 17/91, 18.7%, P = .04) were higher in the reoperation vs index group. Improved headaches and vision were reported in 4/12 (33%) and 8/12 (61.5%) of RCC reoperation patients, respectively. Two patients developed new permanent DI. A higher proportion of reoperation patients had RCC squamous metaplasia (24% vs 5.4%, P = .02) or wall inflammation (42.9% vs 2.2%, P < .001) on pathological examination.

CONCLUSION

Reoperation for RCCs is generally safe at tertiary pituitary centers and often results in improved vision. Hypopituitarism is less likely to improve following reoperation for recurrent RCCs. Several histopathological features may help characterize "atypical RCCs" with a higher likelihood of recurrence/progression.

Costs and training results of an objectively validated cadaveric perfusion-based internal carotid artery injury simulation during endoscopic skull base surgery

BACKGROUND

Internal carotid artery injury (ICAI) is a rare, life-threatening complication of endoscopic endonasal approaches (EEAs). High-fidelity simulation methods exist, but optimization of the training cohort, training paradigm, and costs of simulation training remain unknown.

METHODS

Using our previously validated, high-fidelity, perfused-cadaver model, participants attempted to manage a simulated ICAI. After a brief instructional video and coaching, the simulation was repeated. Training success was defined as successful ICAI control on the second attempt after failure on the initial attempt. Marginal costs were measured.

RESULTS

Seventy-two surgeons participated in the standardized simulation, which lasted ≤15 minutes. The marginal cost of simulation was $275.00 per surgeon. A total of 44.4% (n = 32) succeeded on the first attempt before training (previously proficient); 44.4% (n = 32) failed the first attempt, but succeeded after training (training successes); and 11.1% (n = 8) failed both attempts. The cost per training success was $618.75. Forty-two surgeons had never treated an ICAI, with 24 becoming training successes (57.1% overall, 82.8% when excluding previously proficient surgeons). Twenty-nine had experienced a real or simulated ICAI, with 8 (27.6% overall, 72.7% excluding previously proficient surgeons) becoming training successes. The cost per training success was lowest in the ICAI-naive group ($481.25) and highest among surgeons with simulated and real ICAI experience ($1650).

CONCLUSIONS

Surgeons can be trained to manage ICAI in a single, brief, low-cost session. Although all groups improved, training an ICAI-naive or resident cohort may maximize training results. A perfused-cadaver model is a reproducible, realistic, and low-cost method for training surgeons to manage life-threatening ICAI during an EEA.

Descending Branch of the Lateral Circumflex Femoral Artery Graft for Posterior Inferior Cerebellar Artery Revascularization

BACKGROUND

Posterior inferior cerebellar artery (PICA) revascularization can be achieved with relative ease when a contralateral PICA is present. However, without a contralateral PICA, identification of a suitable vessel alternative can be challenging due to a size mismatch.

OBJECTIVE

To propose the descending branch of the lateral circumflex femoral artery (DLCFA) to be an acceptable, if not preferred, arterial graft for PICA revascularization.

METHODS

Data from patients who underwent PICA revascularization with DLCFA grafts were obtained from an institutional review board-approved prospectively maintained database with informed consent from the patients.

RESULTS

Three patients, all presenting with ruptured aneurysms, were treated with PICA revascularization using the DLCFA. All cases achieved bypass patency and no ischemic events occurred during the bypass procedures. Graft spasm occurred in 2 patients. Two patients that presented with neurological deficits achieved excellent neurological outcomes and 1 suffered an anterior spinal artery stroke during a repeat endovascular treatment 1 wk after revascularization.

CONCLUSION

The DLCFA is favorable for PICA revascularization when a contralateral PICA is not a viable option.

Perfusion-based human cadaveric specimen as a simulation training model in repairing cerebrospinal fluid leaks during endoscopic endonasal skull base surgery

OBJECTIVE

Competency in endoscopic endonasal approaches (EEAs) to repair high-flow cerebrospinal fluid (CSF) leaks is an essential component of the neurosurgical training process. The objective of this study was to demonstrate the feasibility of a simulation model for EEA repair of anterior skull base CSF leaks.

METHODS

Human cadaveric specimens were utilized with a perfusion system to simulate a high-flow CSF leak. Neurological surgery residents (postgraduate year 3 or greater) performed a standard EEA to repair a CSF leak using a combination of fat, fascia lata, and pedicled nasoseptal flaps. A standardized 5-point Likert questionnaire was used to assess the knowledge gained, techniques learned, degree of safety, benefit of CSF perfusion during repair, and pre- and posttraining confidence scores.

RESULTS

Intrathecal perfusion of fluorescein-infused saline into the ventricular/subarachnoid space was successful in 9 of 9 cases. The addition of CSF reconstitution offered the residents visual feedback for confirmation of intraoperative CSF leak repair. Residents gained new knowledge and a realistic simulation experience by rehearsing the psychomotor skills and techniques required to repair a CSF leak with fat and fascial grafts, as well as to prepare and rotate vascularized nasoseptal flaps. All trainees reported feeling safer with the procedure in a clinical setting and higher average posttraining confidence scores (pretraining 2.22 ± 0.83, posttraining 4.22 ± 0.44, p < 0.001).

CONCLUSIONS

Perfusion-based human cadaveric models can be utilized as a simulation training model for repairing CSF leaks during EEA.

Evaluation of C2 pedicle screw placement via the freehand technique by neurosurgical trainees

OBJECTIVE

Freehand placement of C2 instrumentation is technically challenging and has a learning curve due the unique anatomy of the region. This study evaluated the accuracy of C2 pedicle screws placed via the freehand technique by neurosurgical resident trainees.

METHODS

The authors retrospectively reviewed all patients treated at the LAC+USC Medical Center undergoing C2 pedicle screw placement in which the freehand technique was used over a 1-year period, from June 2016 to June 2017; all procedures were performed by neurosurgical residents. Measurements of C2 were obtained from preoperative CT scans, and breach rates were determined from coronal reconstructions on postoperative scans. Severity of breaches reflected the percentage of screw diameter beyond the cortical edge (I = < 25%; II = 26%–50%; III = 51%–75%; IV = 76%–100%).

RESULTS

Neurosurgical residents placed 40 C2 pedicle screws in 24 consecutively treated patients. All screws were placed by or under the guidance of Pham, who is a postgraduate year 7 (PGY-7) neurosurgical resident with attending staff privileges, with a PGY-2 to PGY-4 resident assistant. The authors found an average axial pedicle diameter of 5.8 mm, axial angle of 43.1°, sagittal angle of 23.0°, spinal canal diameter of 25.1 mm, and axial transverse foramen diameter of 5.9 mm. There were 17 screws placed by PGY-2 residents, 7 screws placed by PGY-4 residents, and 16 screws placed by the PGY-7 resident. The average screw length was 26.0 mm, with a screw diameter of 3.5 mm or 4.0 mm. There were 7 total breaches (17.5%), of which 4 were superior (10.0%) and 3 were lateral (7.5%). There were no medial breaches. The breaches were classified as grade I in 3 cases (42.9%), II in 3 cases (42.9%), III in 1 case (14.3%), and IV in no cases. There were 3 breaches that occurred via placement by a PGY-2 resident, 3 breaches by a PGY-4 resident, and 1 breach by the PGY-7 resident. There were no clinical sequelae due to these breaches.

CONCLUSIONS

Freehand placement of C2 pedicle screws can be done safely by neurosurgical residents in early training. When breaches occurred, they tended to be superior in location and related to screw length choice, and no breaches were found to be clinically significant. Controlled exposure to this unique anatomy is especially pertinent in the era of work-hour restrictions.

Complete Cavernous Sinus Resection: An Analysis of Complications

BACKGROUND

Complete cavernous sinus resection has been described for patients with malignant or recurrent cavernous sinus tumors without other therapeutic options but has been associated with high morbidity and mortality rates. We reviewed the complications associated with complete cavernous sinus resection to gain insights for future complication avoidance.

METHODS

A retrospective analysis of a prospective, single-institution database was performed to identify patients who had undergone complete cavernous sinus resection from July 2014 to October 2017. Patient- and disease-specific data, surgical complications, and clinical outcomes were recorded.

RESULTS

Two male patients underwent complete cavernous sinus resection (aged 60 and 47 years) for recurrent maxillary tumors with secondary cavernous sinus extension. Revascularization was performed based on balloon test occlusion (BTO) results, with extracranial-to-intracranial bypass performed in 1 patient with a concerning hemispheric flow pattern found during BTO. Vascularized free flaps were used in both patients to assist with closure of the resulting skull base defect. Three complications related to surgery occurred in 1 patient (thigh hematoma, recurrent cerebrospinal fluid leak, and meningitis). One patient died of pneumonia approximately 2 weeks postoperatively, and the other experienced an acceptable neurologic and oncologic outcome.

CONCLUSIONS

Despite the high peri- and postoperative risks, complete cavernous sinus resection can be considered for select patients with tumors involving the cavernous sinus without other treatment options. Familiarity with cerebral bypass and free flap reconstruction of skull base defects is critical for complication avoidance and management.

Extended endoscopic endonasal approach for resection of tuberculum sellae meningioma

Meningiomas are the most prevalent primary intracranial tumor, with 3%-10% arising from the tuberculum sellae. Optimal management consists of total microsurgical resection with preservation of surrounding structures. The authors present a 64-year-old woman with progressive bilateral vision loss, including visual acuity deficits and bitemporal hemianopsia. MRI revealed a 2-cm tuberculum sellae meningioma causing optic apparatus compression. An extended endoscopic endonasal transtuberculum approach was utilized for gross-total resection, including microdissection of tumor from the optic chiasm and infundibulum. Closure was performed with multilayer tensor fascia lata autograft and a pedicled nasal-septal flap. The patient's postoperative exam showed visual improvement and normal pituitary function. The video can be found here: https://youtu.be/ZfNB_rhlyeI .

Spine Surgery Complicated by an Engorged Lumbar Epidural Venous Plexus from Cerebrospinal Fluid Overshunting: A Case Report and Review of the Literature

BACKGROUND

Overshunting of cerebrospinal fluid may lead to intracranial hypotension and dilation of spinal epidural veins. Radiculopathy may rarely occur secondary to engorged spinal epidural veins. In addition, the cause of radiculopathy may be obscured by concomitant spinal degenerative changes. We present a case and review the pathogenesis as well as the current clinical literature.

CASE DESCRIPTION

A 29-year-old woman presented with positional headaches from intracranial hypotension in the setting of cerebrospinal fluid overshunting. The patient also had back pain and lumbar radiculopathy, which became more severe after lumboperitoneal shunt placement. On radiographic work-up, there was evidence of right L5 nerve root impingement secondary to a disc bulge and an engorged lumbar epidural venous plexus secondary to overshunting. The patient underwent surgery for a planned L4-5 decompression with a transforaminal lumbar interbody fusion. The operation was complicated by rapid blood loss originating from the epidural venous plexus, and we were unable to safely place the interbody graft.

CONCLUSIONS

Spinal surgeons need to be aware of the rare diagnosis of radiculopathy secondary to epidural venous plexus engorgement, as it may change the treatment approach or lead to deleterious intraoperative consequences, such as hemorrhage.

Association between changes in weight and cerebral arteries in rats

The objective of the study was to gain a better understanding of brain artery diameters and anatomical variations for precise modification of cerebral blood supply in ischemic stroke models. Sprague-Dawley rats (n = 35) were used for the experiment. Rats were perfused and resin replicas of cerebral arteries were created using a corrosion casting technique. Resin replicas were measured and analyzed for correlation of vessel lumen with animal sex and weight. A strong correlation between root of aorta diameter and weight was observed (p < 0.0001). We also observed a significant correlation between weight, internal carotid arteries, right external carotid artery, and pterygopalatine arteries. For the common carotid artery, a significant difference between the left and right branches was observed even though there was no association with weight. There was no significant association observed between animal sex and vessel size independent of weight. A better knowledge of vessel lumen in relation to animal sex and weight is essential for adequate blockage of an intracranial artery to induce cerebral ischemia in a rat model of stroke. This study provides a viable reference for choice of rat size in relation to the size of embolic agents such as filaments, microwires, or in vitro thrombus used in ischemic stroke experiments.