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.

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 .

How should we grade lumbar disc herniation and nerve root compression? A systematic review.

BACKGROUND: MRI is the gold standard for evaluating the relationship of disc material to soft tissue and neural structures. However, terminologies used to describe lumbar disc herniation and nerve root compression have always been a source of confusion. A clear understanding of lumbar disc terminology among clinicians, radiologists, and researchers is vital for patient care and future research. QUESTIONS/PURPOSES: Through a systematic review of the literature, the purpose of this article is to describe lumbar disc terminology and comment on the reliability of various nomenclature systems and their application to clinical practice. METHODS: PubMed was used for our literature search using the following MeSH headings: "Magnetic Resonance Imaging and Intervertebral Disc Displacement" and "Lumbar Vertebrae" and terms "nomenclature" or "grading" or "classification". Ten papers evaluating lumbar disc herniation/nerve root compression using different grading criteria and providing information regarding intraobserver and interobserver agreement were identified. RESULTS: To date, the Combined Task Force (CTF) and van Rijn classification systems are the most reliable methods for describing lumbar disc herniation and nerve root compression, respectively. van Rijn dichotomized nerve roots from "definitely no root compression, possibly no root compression, indeterminate root compression, possible root compression, and definite root compression" into no root compression (first three categories) and root compression (last two categories). The CTF classification defines lumbar discs as normal, focal protrusion, broad-based protrusion, or extrusion. The CTF classification system excludes "disc bulges," which is a source of confusion and disagreement among many practitioners. This potentially accounts for its improved reliability compared with other proposed nomenclature systems. CONCLUSIONS: The main issue in the management of patients with lumbar disc disease and nerve root compression is correlation of imaging findings with clinical presentation and symptomatology to guide treatment and intervention. Although it appears that the most commonly supported nomenclatures have strong interobserver reliability, the classification term "disc bulges" is a source of confusion and disagreement among many practitioners. Additional research should focus on the clinical application of the various nomenclatures.

Sacral fractures.

Sacral fractures are uncommon lesions and most often the result of high-energy trauma. Depending on the fracture location, neurological injury may be present in over 50% of cases. In this article, the authors conducted a comprehensive literature review on the epidemiology of sacral fractures, relevant anatomy of the sacral and pelvic region, common sacral injuries and fractures, classification systems of sacral fractures, and current management strategies. Due to the complex nature of these injuries, surgical management remains a challenge for the attending surgeon. Few large-scale studies have addressed postoperative complications or long-term results, but current evidence suggests that although fusion rates are high, long-term morbidity, such as residual pain and neurological deficits, persists for many patients.

Enhanced neuroprotection by local intra-arterial infusion of human albumin solution and local hypothermia.

BACKGROUND AND PURPOSE: We investigated the potential benefit of using a local infusion of low-dose and cold human albumin in ischemic rats as compared with systemic delivery. METHODS: Stroke was induced in rats, and at 2 hours treatment groups received 0°C saline or low-dose albumin at 0°C or 37°C infused into the ischemic area. RESULTS: The local low-dose cold albumin infusion, which achieved the hypothermic temperature (P<0.001), produced the greatest reduction in infarct volume and the best recovery of neurological function. CONCLUSIONS: The local low-dose cold albumin infusion into the ischemic area offered a combination of regional brain hypothermia and albumin administration, which enhanced neuroprotection and would be beneficial in the clinical setting.

Synergetic neuroprotection of normobaric oxygenation and ethanol in ischemic stroke through improved oxidative mechanism.

BACKGROUND AND PURPOSE: Normobaric oxygenation (NBO) and ethanol both provide neuroprotection in stroke. We evaluated the enhanced neuroprotective effect of combining these 2 treatments in a rat stroke model. METHODS: Sprague-Dawley rats were subjected to middle cerebral artery occlusion for 2 hours. Reperfusion was then established and followed by treatment with either (1) an intraperitoneal injection of ethanol (1.0 g/kg), (2) NBO treatment (2-hour duration), or (3) NBO plus ethanol. The extent of brain injury was determined by infarct volume and motor performance. Oxidative metabolism was determined by ADP/ATP ratios, reactive oxygen species levels, nicotinamide adenine dinucleotide phosphate oxidase activity, and pyruvate dehydrogenase activity. Protein expression of major nicotinamide adenine dinucleotide phosphate oxidase subunits (p47(phox), gp91(phox), and p67(phox)) and the enzyme pyruvate dehydrogenase was evaluated through Western immunoblotting. RESULTS: NBO and ethanol monotherapies each demonstrated reductions as compared to stroke without treatment in infarct volume (36.7% and 37.9% vs 48.4%) and neurological deficits (score of 6.4 and 6.5 vs 8.4); however, the greatest neuroprotection (18.8% of infarct volume and 4.4 neurological deficit) was found in animals treated with combination therapy. This neuroprotection was associated with the largest reductions in ADP/ATP ratios, reactive oxygen species levels, and nicotinamide adenine dinucleotide phosphate oxidase activity, and the largest increase in pyruvate dehydrogenase activity. CONCLUSIONS: Combination therapy with NBO and ethanol enhances the neuroprotective effect produced by each therapy alone. The mechanism behind this synergistic action is related to changes in cellular metabolism after ischemia reperfusion. NBO plus ethanol is attractive for clinical study because of its ease of use, tolerability, and tremendous neuroprotective potential in stroke.

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.

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.

Extent of Resection Research in Skull Base Neurosurgery: Previous Studies and Future Directions.

Surgery is the first-line therapy for most benign and malignant skull base tumors. Extent of resection (EOR) is a metric commonly used for preoperative surgical planning and to predict risk of postoperative tumor recurrence. Therefore, understanding the evidence on EOR in skull base neurosurgery is essential to providing optimal care for each patient. Several studies from the skull base neurosurgery literature have presented investigations of various topics related to EOR, including 1) preoperative EOR scoring systems, 2) intraoperative EOR scoring systems, 3) EOR and tumor recurrence, and 4) EOR and functional outcomes. We propose that future investigations should focus on the following elements to improve EOR research in skull base neurosurgery: 1) multi-institutional collaboratives with treatment propensity matching; 2) expert consensus and mixed-methods study design; and 3) predictive analytics/machine learning. We believe that these methods offer several advantages that have been described in the literature and that they address limitations of previous studies. The aim of this review was to inform future study design and improve the overall quality of subsequent investigations on EOR in skull base neurosurgery.

Microscopic Transsphenoidal Surgery in the Era of Endoscopy: Are There Any Advantages?

Developed over 50 years ago, the microscopic transsphenoidal approach is a simple, efficient technique with proven efficacy for the surgical treatment of an array of sellar and parasellar diseases. Although utilization of fully endoscopic transsphenoidal approaches has dramatically increased recently because it offers enhanced visualization, current outcomes data do not clearly favor either approach. Potential advantages of the microscope that persist in the endoscopic era include decreased operative time; preservation of a single-surgeon, unobstructed, twohanded microsurgical technique; and limited disruption of the nasal mucosa. Endoscope-assisted microsurgical approaches can also be used to overcome limitations in visualization while preserving the aforementioned advantages.

Visual Outcomes in Spheno-Orbital Meningioma: A 10-Year Experience.

BACKGROUND: Spheno-orbital meningiomas (SOMs) present distinct surgical challenges because they involve important neurovascular structures, such as the orbit, cavernous sinus, superior orbital fissure, and optic canal. Resection thus focuses on maximum safe resection while preserving these neurovascular structures. Our objective was to describe our method of surgical management of SOMs and summarize visual outcomes. METHODS: A retrospective chart review was performed to identify patients who underwent surgery for SOM in 2011-2021. Demographics, preoperative visual summary, operative details, visual outcomes, and recurrence data were collected. RESULTS: The 33 patients (10 male, 23 female) had a mean age of 56 years (range 27-74 years). The mean tumor volume was 39 mL (range 4.7-220 mL). The mean follow-up period was 18 months (range 1-120 months). Thirty-two patients had preoperative radiographic evidence of proptosis (based on exophthalmos index), 23 (70%) presented with diminished visual acuity, and 10 (30%) had a concomitant visual field deficit. At last postoperative follow-up, vision was stable for 25 patients (83.3%), improved for 1 (3.3%), and worsened for 3 (10%; 2 occurring after tumor recurrence beyond 2 years). Proptosis was stable or improved in all patients. One patient had an enucleated eye. A total of 7 patients (21%) had recurrence of the tumor at 19-72 months from the operation. CONCLUSIONS: In this study, maximum safe resection, including periorbital resection, provided adequate visual and cosmetic outcomes, as well as reasonable tumor control in the long term. Rigid orbital reconstruction was not required to prevent pulsatile enophthalmos.

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.

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.

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.

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.

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.

In Vivo Preclinical Quantitative Flow Analysis of Arterial Anastomosis Using a Microvascular Anastomotic Coupler and Clinical Application for Extracranial-to-Intracranial Bypass.

OBJECTIVE: Although several commercially available sutureless anastomotic techniques are available, they are not routinely used in neurosurgery. We performed an in vivo flow analysis of end-to-end anastomosis using a microvascular coupler device in rats. We report our first clinical use of the microvascular anastomotic coupler. METHODS: Bilateral rat common carotid arteries (CCAs) were exposed, and a microvascular coupler was used to perform 8 anastomoses. A microflow probe provided quantitative measurement of blood-flow volume. Flow augmentation was assessed with end-to-side anastomoses connecting the distal CCA to the jugular vein (JV). A patient with chronic dominant hemisphere atherosclerotic ischemic disease and progressive symptoms refractory to medical management underwent end-to-end cerebral artery bypass using the microvascular coupler. RESULTS: Mean preanastomosis flow in the rat CCA was 3.95 ± 0.45 mL/min; this flow was maintained at 3.99 ± 0.24 mL/min on final measurements 54-96 minutes postanastomosis. Total occlusion time for each rat CCA was 12-19 minutes. After end-to-side anastomosis, with proximal and distal JV patent, CCA flow increased 477% to 22.8 ± 3.70 mL/min (P = 0.04, proximal; P = 0.01, distal). After in vivo testing, we successfully used the coupler clinically in a superficial temporal artery-to-middle cerebral artery bypass for dominant hemisphere flow augmentation. CONCLUSIONS: In vivo quantitative flow analysis demonstrated no flow difference between an unaltered artery and artery with end-to-end anastomosis using a microvascular coupler in rats. A 1-mm coupled anastomosis achieved a 4-fold flow increase with low-resistance venous outflow in rats, simulating increased arterial demand. The coupler was successfully used for extracranial-to-intracranial bypass in a patient.