Alexander I Evins | Weill Cornell Medicine (original) (raw)

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Papers by Alexander I Evins

Research paper thumbnail of 3D Anatomy of the Cerebello-Pontine Angle Through a Retrosigmoid Approach: A Comparative Study Using a Microscope and a 3D Endoscope

Research paper thumbnail of Operative Technique Endoscopic extradural anterior clinoidectomy and optic nerve decompression through a pterional port

Research paper thumbnail of 3D Endoscope-Assisted Anatomy of the Foramen Magnum and Cranio-Vertebral Junction Through a Far Lateral Approach – A Technical Note

Research paper thumbnail of Microscopic and Endoscopic 3D Surgical Anatomy of the Cerebello-Pontine Angle through the Retromastoid Approach

Research paper thumbnail of 3D Endoscope-Assisted Surgical Anatomy of the Retrosigmoid and Far Lateral Approaches

Research paper thumbnail of The role of alternative anastomosis sites in occipital artery–posterior inferior cerebellar artery bypass in the absence of the caudal loop using the far-lateral approach

Journal of Neurosurgery, 2017

OBJECTIVE Occipital artery-posterior inferior cerebellar artery (OA-PICA) bypass is a technically... more OBJECTIVE Occipital artery-posterior inferior cerebellar artery (OA-PICA) bypass is a technically challenging procedure for posterior fossa revascularization. The caudal loop of the PICA is considered the optimal site for OA-PICA anastomosis, however its absence can increase the technical difficulty associated with this procedure. The use of the far-lateral approach for accessing alternative anastomosis sites in OA-PICA bypass in patients with absent or unavailable caudal loops of PICA is evaluated. METHODS A morphometric analysis of OA-PICA bypass with anastomosis on each segment of the PICA was performed on 5 cadaveric specimens through the conventional midline foramen magnum and far-lateral approaches. The difficulty level associated with anastomoses at each segment was qualitatively assessed in each approach for exposure and maneuverability by multiple surgeons. A series of 8 patients who underwent OA-PICA bypass for hemodynamic ischemia or ruptured dissecting posterior fossa aneurysms are additionally reviewed and described, and the clinical significance of the caudal loop of PICA is discussed. RESULTS Anastomosis on the caudal loop could be performed more superficially than on any other segment (p < 0.001). A far-lateral approach up to the medial border of the posterior condylar canal provided a 13.5 ± 2.2-mm wider corridor than the conventional midline foramen magnum approach, facilitating access to alternative anastomosis sites. The far-lateral approach was successfully used for OA-PICA bypass in 3 clinical cases whose caudal loops were absent, whereas the midline foramen magnum approach provided sufficient exposure for caudal loop bypass in the remaining 5 cases. CONCLUSIONS The absence of the caudal loop of the PICA is a major contributing factor to the technical difficulty of OA-PICA bypass. The far-lateral approach is a useful surgical option for OA-PICA bypass when the caudal loop of the PICA is unavailable.

Research paper thumbnail of The Infralabyrinthine Route to the Petrous Apex: A Comparison of the Extradural Infralabyrinthine and Retrosigmoid Intradural Inframeatal Approaches

Journal of Neurological Surgery Part B: Skull Base, 2016

Research paper thumbnail of Microscopic and Endoscopic Anatomy of the Foramen Magnum and Cranio-vertebral Junction in a Transtubular Far Lateral Approach

Journal of Neurological Surgery Part B: Skull Base, 2016

Research paper thumbnail of The rectus capitis lateralis and the condylar triangle: important landmarks in posterior and lateral approaches to the jugular foramen

Journal of neurosurgery, Jan 27, 2017

OBJECTIVE The rectus capitis lateralis (RCL) is a small posterior cervical muscle that originates... more OBJECTIVE The rectus capitis lateralis (RCL) is a small posterior cervical muscle that originates from the transverse process of C-1 and inserts onto the jugular process of the occipital bone. The authors describe the RCL and its anatomical relationships, and discuss its utility as a surgical landmark for safe exposure of the jugular foramen in extended or combined skull base approaches. In addition, the condylar triangle is defined as a landmark for localizing the vertebral artery (VA) and occipital condyle. METHODS Four cadaveric heads (8 sides) were used to perform far-lateral, extended far-lateral, combined transmastoid infralabyrinthine transcervical, and combined far-lateral transmastoid infralabyrinthine transcervical approaches to the jugular foramen. On each side, the RCL was dissected, and its musculoskeletal, vascular, and neural relationships were examined. RESULTS The RCL lies directly posterior to the internal jugular vein-only separated by the carotid sheath and in so...

Research paper thumbnail of An Extensive Anatomosurgical Study of the Interpeduncular Fossa through Multiple Surgical Corridors

Journal of Neurological Surgery Part B: Skull Base, 2016

Research paper thumbnail of Neurosurgical Postgraduate Training in China: Moving Toward A National Training Standard

World neurosurgery, Jan 15, 2016

China is currently the most populous and rapidly aging nation in the world. In the next few decad... more China is currently the most populous and rapidly aging nation in the world. In the next few decades, China will have to increase the throughput, quality, and scope of its neurosurgical training programs in order to meet forecasted demand. Until recently, China lacked national education standards in neurosurgery that fostered imbalances in medical and pedagogical resources, quality of care, and education between different regions; and introduced significant heterogeneity in neurosurgical competency. In 2010, Shanghai implemented the first new standards-based comprehensive neurosurgery training program, which spans 7 years broken down into 2 blocks. This model was subsequently selected for nationwide adoption by the Chinese Congress of Neurological Surgeons, with initial implementation in 2015 and full nationwide adoption by 2020. Establishment of a national standardized training system represents a significant milestone in the development and evolution of neurosurgery in China, and e...

Research paper thumbnail of Rectus Capitis Lateralis: An Important Landmark in Posterolateral Approaches to the Craniocervical Junction

Journal of Neurological Surgery Part B: Skull Base, 2016

Research paper thumbnail of The Extra-Cranial Facial Nerve As Seen In Different Surgical Approaches: An Extensive Anatomo-Surgical Study

Research paper thumbnail of Resection of Synthetic Petroclival Meningiomas in a 3D-Endoscopic Transtubular Anterior Transpetrosal Approach

Research paper thumbnail of Quantitative Comparison of 3D-Endoscopic Transtubular Transcortical and Transcallosal Approaches for Excision of Hypothalamic Hamartomas Using a Synthetic Tumor Model

Research paper thumbnail of Postoperative Intracranial Hypotension-Associated Venous Congestion (PIHV): A Potentially Fatal Operative Complication Following Cranial and Spinal Surgery

Research paper thumbnail of Dual-Port Endoscopy: Expanding the Lateral Limits of the Endonasal Approaches

Research paper thumbnail of Selective Patch Angioplasty and Intraoperative Shunting in Carotid Endarterectomy: A Single-Center Review of 141 Procedures

Cureus, 2015

Open surgical treatment of carotid artery stenosis, namely, carotid endarterectomy (CEA), has evo... more Open surgical treatment of carotid artery stenosis, namely, carotid endarterectomy (CEA), has evolved since its inception in 1953. Despite improvements in the treatment of carotid occlusive disease through technological and surgical innovations, the use of patch grafting in CEA's remains controversial. We evaluate the durability of the primary closure and the safety of selective shunting during carotid endarterectomy (CEA) as determined by intraoperative EEG and postoperative outcomes. A consecutive series of CEA's performed by the senior author at a single academic medical center from 2001 to 2012 were reviewed. All cases were performed under continuous intraoperative electroencephalography (EEG). Patch angioplasty was used in cases where there was tortuosity of the vessel within the region of the endarterectomy and narrow vessel diameter at the distal end of the arteriotomy. Shunting was used when intraoperative EEG showed a > 50% reduction in a waveform in any lead. Patients were evaluated for restenosis via imaging or ultrasound at six months and subsequently annual follow-up. One hundred and forty-one CEA's were performed on 132 (76 male, 56 female) patients with an average age of 71 years (range: 40-95 years). Four (3%) cases required patch angioplasty and three (2%) required intraoperative shunts. The cross-clamp time ranged from 22 to 74 minutes, and the duration increased with the use of shunts and patches. Complications were rare and included recurrent stenosis (n=2), postoperative transient ischemic attack (n=1), ischemic stroke in (n=1), temporary hypoglossal nerve weakness (n=2), temporary marginal mandibular nerve weakness (n=6), and neck hematoma (n=1). Intraoperative EEG data suggests that primary closure and selective shunting in CEA can result in outcomes comparable with routine patch angioplasty and shunting.

Research paper thumbnail of Three Dimensional Microsurgical Anatomy of the Third Ventricle through the Trans-lamina Terminalis Approach: A Cadaveric Study

Research paper thumbnail of 3D Endoscope-Assisted Surgical Anatomy of the Retrosigmoid and Far Lateral Approaches

Research paper thumbnail of 3D Anatomy of the Cerebello-Pontine Angle Through a Retrosigmoid Approach: A Comparative Study Using a Microscope and a 3D Endoscope

Research paper thumbnail of Operative Technique Endoscopic extradural anterior clinoidectomy and optic nerve decompression through a pterional port

Research paper thumbnail of 3D Endoscope-Assisted Anatomy of the Foramen Magnum and Cranio-Vertebral Junction Through a Far Lateral Approach – A Technical Note

Research paper thumbnail of Microscopic and Endoscopic 3D Surgical Anatomy of the Cerebello-Pontine Angle through the Retromastoid Approach

Research paper thumbnail of 3D Endoscope-Assisted Surgical Anatomy of the Retrosigmoid and Far Lateral Approaches

Research paper thumbnail of The role of alternative anastomosis sites in occipital artery–posterior inferior cerebellar artery bypass in the absence of the caudal loop using the far-lateral approach

Journal of Neurosurgery, 2017

OBJECTIVE Occipital artery-posterior inferior cerebellar artery (OA-PICA) bypass is a technically... more OBJECTIVE Occipital artery-posterior inferior cerebellar artery (OA-PICA) bypass is a technically challenging procedure for posterior fossa revascularization. The caudal loop of the PICA is considered the optimal site for OA-PICA anastomosis, however its absence can increase the technical difficulty associated with this procedure. The use of the far-lateral approach for accessing alternative anastomosis sites in OA-PICA bypass in patients with absent or unavailable caudal loops of PICA is evaluated. METHODS A morphometric analysis of OA-PICA bypass with anastomosis on each segment of the PICA was performed on 5 cadaveric specimens through the conventional midline foramen magnum and far-lateral approaches. The difficulty level associated with anastomoses at each segment was qualitatively assessed in each approach for exposure and maneuverability by multiple surgeons. A series of 8 patients who underwent OA-PICA bypass for hemodynamic ischemia or ruptured dissecting posterior fossa aneurysms are additionally reviewed and described, and the clinical significance of the caudal loop of PICA is discussed. RESULTS Anastomosis on the caudal loop could be performed more superficially than on any other segment (p < 0.001). A far-lateral approach up to the medial border of the posterior condylar canal provided a 13.5 ± 2.2-mm wider corridor than the conventional midline foramen magnum approach, facilitating access to alternative anastomosis sites. The far-lateral approach was successfully used for OA-PICA bypass in 3 clinical cases whose caudal loops were absent, whereas the midline foramen magnum approach provided sufficient exposure for caudal loop bypass in the remaining 5 cases. CONCLUSIONS The absence of the caudal loop of the PICA is a major contributing factor to the technical difficulty of OA-PICA bypass. The far-lateral approach is a useful surgical option for OA-PICA bypass when the caudal loop of the PICA is unavailable.

Research paper thumbnail of The Infralabyrinthine Route to the Petrous Apex: A Comparison of the Extradural Infralabyrinthine and Retrosigmoid Intradural Inframeatal Approaches

Journal of Neurological Surgery Part B: Skull Base, 2016

Research paper thumbnail of Microscopic and Endoscopic Anatomy of the Foramen Magnum and Cranio-vertebral Junction in a Transtubular Far Lateral Approach

Journal of Neurological Surgery Part B: Skull Base, 2016

Research paper thumbnail of The rectus capitis lateralis and the condylar triangle: important landmarks in posterior and lateral approaches to the jugular foramen

Journal of neurosurgery, Jan 27, 2017

OBJECTIVE The rectus capitis lateralis (RCL) is a small posterior cervical muscle that originates... more OBJECTIVE The rectus capitis lateralis (RCL) is a small posterior cervical muscle that originates from the transverse process of C-1 and inserts onto the jugular process of the occipital bone. The authors describe the RCL and its anatomical relationships, and discuss its utility as a surgical landmark for safe exposure of the jugular foramen in extended or combined skull base approaches. In addition, the condylar triangle is defined as a landmark for localizing the vertebral artery (VA) and occipital condyle. METHODS Four cadaveric heads (8 sides) were used to perform far-lateral, extended far-lateral, combined transmastoid infralabyrinthine transcervical, and combined far-lateral transmastoid infralabyrinthine transcervical approaches to the jugular foramen. On each side, the RCL was dissected, and its musculoskeletal, vascular, and neural relationships were examined. RESULTS The RCL lies directly posterior to the internal jugular vein-only separated by the carotid sheath and in so...

Research paper thumbnail of An Extensive Anatomosurgical Study of the Interpeduncular Fossa through Multiple Surgical Corridors

Journal of Neurological Surgery Part B: Skull Base, 2016

Research paper thumbnail of Neurosurgical Postgraduate Training in China: Moving Toward A National Training Standard

World neurosurgery, Jan 15, 2016

China is currently the most populous and rapidly aging nation in the world. In the next few decad... more China is currently the most populous and rapidly aging nation in the world. In the next few decades, China will have to increase the throughput, quality, and scope of its neurosurgical training programs in order to meet forecasted demand. Until recently, China lacked national education standards in neurosurgery that fostered imbalances in medical and pedagogical resources, quality of care, and education between different regions; and introduced significant heterogeneity in neurosurgical competency. In 2010, Shanghai implemented the first new standards-based comprehensive neurosurgery training program, which spans 7 years broken down into 2 blocks. This model was subsequently selected for nationwide adoption by the Chinese Congress of Neurological Surgeons, with initial implementation in 2015 and full nationwide adoption by 2020. Establishment of a national standardized training system represents a significant milestone in the development and evolution of neurosurgery in China, and e...

Research paper thumbnail of Rectus Capitis Lateralis: An Important Landmark in Posterolateral Approaches to the Craniocervical Junction

Journal of Neurological Surgery Part B: Skull Base, 2016

Research paper thumbnail of The Extra-Cranial Facial Nerve As Seen In Different Surgical Approaches: An Extensive Anatomo-Surgical Study

Research paper thumbnail of Resection of Synthetic Petroclival Meningiomas in a 3D-Endoscopic Transtubular Anterior Transpetrosal Approach

Research paper thumbnail of Quantitative Comparison of 3D-Endoscopic Transtubular Transcortical and Transcallosal Approaches for Excision of Hypothalamic Hamartomas Using a Synthetic Tumor Model

Research paper thumbnail of Postoperative Intracranial Hypotension-Associated Venous Congestion (PIHV): A Potentially Fatal Operative Complication Following Cranial and Spinal Surgery

Research paper thumbnail of Dual-Port Endoscopy: Expanding the Lateral Limits of the Endonasal Approaches

Research paper thumbnail of Selective Patch Angioplasty and Intraoperative Shunting in Carotid Endarterectomy: A Single-Center Review of 141 Procedures

Cureus, 2015

Open surgical treatment of carotid artery stenosis, namely, carotid endarterectomy (CEA), has evo... more Open surgical treatment of carotid artery stenosis, namely, carotid endarterectomy (CEA), has evolved since its inception in 1953. Despite improvements in the treatment of carotid occlusive disease through technological and surgical innovations, the use of patch grafting in CEA's remains controversial. We evaluate the durability of the primary closure and the safety of selective shunting during carotid endarterectomy (CEA) as determined by intraoperative EEG and postoperative outcomes. A consecutive series of CEA's performed by the senior author at a single academic medical center from 2001 to 2012 were reviewed. All cases were performed under continuous intraoperative electroencephalography (EEG). Patch angioplasty was used in cases where there was tortuosity of the vessel within the region of the endarterectomy and narrow vessel diameter at the distal end of the arteriotomy. Shunting was used when intraoperative EEG showed a > 50% reduction in a waveform in any lead. Patients were evaluated for restenosis via imaging or ultrasound at six months and subsequently annual follow-up. One hundred and forty-one CEA's were performed on 132 (76 male, 56 female) patients with an average age of 71 years (range: 40-95 years). Four (3%) cases required patch angioplasty and three (2%) required intraoperative shunts. The cross-clamp time ranged from 22 to 74 minutes, and the duration increased with the use of shunts and patches. Complications were rare and included recurrent stenosis (n=2), postoperative transient ischemic attack (n=1), ischemic stroke in (n=1), temporary hypoglossal nerve weakness (n=2), temporary marginal mandibular nerve weakness (n=6), and neck hematoma (n=1). Intraoperative EEG data suggests that primary closure and selective shunting in CEA can result in outcomes comparable with routine patch angioplasty and shunting.

Research paper thumbnail of Three Dimensional Microsurgical Anatomy of the Third Ventricle through the Trans-lamina Terminalis Approach: A Cadaveric Study

Research paper thumbnail of 3D Endoscope-Assisted Surgical Anatomy of the Retrosigmoid and Far Lateral Approaches