Ali M. Elhadi

Spontaneous subarachnoid hemorrhage of unknown origin: hospital course and long-term clinical and angiographic follow-up.

OBJECT Hemorrhagic origin is unidentifiable in 10%-20% of patients presenting with spontaneous subarachnoid hemorrhage (SAH). While the patients in such cases do well clinically, there is a lack of long-term angiographic followup. The authors of the present study evaluated the long-term clinical and angiographic follow-up of a patient cohort with SAH of unknown origin that had been enrolled in the Barrow Ruptured Aneurysm Trial (BRAT). METHODS The BRAT database was searched for patients with SAH of unknown origin despite having undergone two or more angiographic studies as well as MRI of the brain and cervical spine. Follow-up was available at 6 months and 1 and 3 years after treatment. Analysis included demographic details, clinical outcome (Glasgow Outcome Scale, modified Rankin Scale [mRS]), and repeat vascular imaging. RESULTS Subarachnoid hemorrhage of unknown etiology was identified in 57 (11.9%) of the 472 patients enrolled in the BRAT study between March 2003 and January 2007. The mean age for this group was 51 years, and 40 members (70%) of the group were female. Sixteen of 56 patients (28.6%) required placement of an external ventricular drain for hydrocephalus, and 4 of these subsequently required a ventriculoperitoneal shunt. Delayed cerebral ischemia occurred in 4 patients (7%), leading to stroke in one of them. There were no rebleeding events. Eleven patients were lost to followup, and one patient died of unrelated causes. At the 3-year follow-up, 4 (9.1%) of 44 patients had a poor outcome (mRS > 2), and neurovascular imaging, which was available in 33 patients, was negative. CONCLUSIONS Hydrocephalus and delayed cerebral ischemia, while infrequent, do occur in SAH of unknown origin. Long-term neurological outcomes are generally good. A thorough evaluation to rule out an etiology of hemorrhage is necessary; however, imaging beyond 6 weeks from ictus has little utility, and rebleeding is unexpected.

Long-term functional outcomes and predictors of shunt-dependent hydrocephalus after treatment of ruptured intracranial aneurysms in the BRAT trial: revisiting the clip vs coil debate.

BACKGROUND Acute hydrocephalus is a well-known sequela of aneurysmal subarachnoid hemorrhage (SAH). Controversy exists about whether open microsurgical methods serve to reduce shunt dependency compared with endovascular techniques. OBJECTIVE To determine predictors of shunt-dependent hydrocephalus and functional outcomes after aneurysmal SAH. METHODS A total of 471 patients who were part of a prospective, randomized, controlled trial from 2003 to 2007 were retrospectively reviewed. All variables including demographic data, medical history, treatment, imaging, and functional outcomes were included as part of the trial. No additional variables were retrospectively collected. RESULTS Ultimately, 147 patients (31.2%) required a ventriculoperitoneal shunt (VPS) in our series. Age, dissecting aneurysm type, ruptured vertebrobasilar aneurysm, Fisher grade, Hunt and Hess grade, admission intraventricular hemorrhage, admission intraparenchymal hemorrhage, blood in the fourth ventricle on admission, perioperative ventriculostomy, and hemicraniectomy were significant risk factors (P < .05) associated with shunt-dependent hydrocephalus on univariate analysis. On multivariate analysis, intraventricular hemorrhage and intraparenchymal hemorrhage were independent risk factors for shunt dependency (P < .05). Clipping vs coiling treatment was not statistically associated with VPS after SAH on both univariate and multivariate analyses. Patients who did not receive a VPS at discharge had higher Glasgow Outcome Scale and Barthel Index scores and were more likely to be functionally independent and to return to work 72 months after surgery (P < .05). CONCLUSION There is no difference in shunt dependency after SAH among patients treated by endovascular or microsurgical means. Patients in whom shunt-dependent hydrocephalus does not develop after SAH tend to have improved long-term functional outcomes.

Potential application of a handheld confocal endomicroscope imaging system using a variety of fluorophores in experimental gliomas and normal brain.

OBJECT The authors sought to assess the feasibility of a handheld visible-wavelength confocal endomicroscope imaging system (Optiscan 5.1, Optiscan Pty., Ltd.) using a variety of rapid-acting fluorophores to provide histological information on gliomas, tumor margins, and normal brain in animal models. METHODS Mice (n = 25) implanted with GL261 cells were used to image fluorescein sodium (FNa), 5-aminolevulinic acid (5-ALA), acridine orange (AO), acriflavine (AF), and cresyl violet (CV). A U251 glioma xenograft model in rats (n = 5) was used to image sulforhodamine 101 (SR101). A swine (n = 3) model with AO was used to identify confocal features of normal brain. Images of normal brain, obvious tumor, and peritumoral zones were collected using the handheld confocal endomicroscope. Histological samples were acquired through biopsies from matched imaging areas. Samples were visualized with a benchtop confocal microscope. Histopathological features in corresponding confocal images and photomicrographs of H & E-stained tissues were reviewed. RESULTS Fluorescence induced by FNa, 5-ALA, AO, AF, CV, and SR101 and detected with the confocal endomicroscope allowed interpretation of histological features. Confocal endomicroscopy revealed satellite tumor cells within peritumoral tissue, a definitive tumor border, and striking fluorescent cellular and subcellular structures. Fluorescence in various tumor regions correlated with standard histology and known tissue architecture. Characteristic features of different areas of normal brain were identified as well. CONCLUSIONS Confocal endomicroscopy provided rapid histological information precisely related to the site of microscopic imaging with imaging characteristics of cells related to the unique labeling features of the fluorophores. Although experimental with further clinical trial validation required, these data suggest that intraoperative confocal imaging can help to distinguish normal brain from tumor and tumor margin and may have application in improving intraoperative decisions during resection of brain tumors.

Revascularization and pediatric aneurysm surgery

OBJECT Aneurysms are relatively rare in the pediatric population and tend to include a greater proportion of large and giant lesions. A subset of these large and giant aneurysms are not amenable to direct surgical clipping and require complex treatment strategies and revascularization techniques. There are limited data available on the management of these lesions in the pediatric population. This study was undertaken to evaluate the outcome of treatment of large and giant aneurysms that required microsurgical revascularization and vessel sacrifice in this population. METHODS The authors retrospectively identified all cases in which pediatric patients (age < 18 years) with aneurysms were treated using cerebral revascularization in combination with other treatment modalities at their institution between 1989 and 2013. RESULTS The authors identified 27 consecutive patients (19 male and 8 female) with 29 aneurysms. The mean age of the patients at the time of treatment was 11.5 years (median 13 years, range 1-17 years). Five patients presented with subarachnoid hemorrhage, 11 with symptoms related to mass effect, 2 with stroke, and 3 with seizures; in 6 cases, the aneurysms were incidental findings. Aneurysms were located along the internal carotid artery (n = 7), posterior cerebral artery (PCA) (n = 2), anterior cerebral artery (n = 2), middle cerebral artery (MCA) (n = 14), basilar artery (n = 2), vertebral artery (n = 1), and at the vertebrobasilar junction (n = 1). Thirteen were giant aneurysms (45%). The majority of the aneurysms were fusiform (n = 19, 66%), followed by saccular (n = 10, 34%). Three cases were previously treated using microsurgery (n = 2) or an endovascular procedure (n = 1). A total of 28 revascularization procedures were performed, including superficial temporal artery (STA) to MCA (n = 6), STA to PCA (n = 1), occipital artery to PCA (n = 1), extracranial-intracranial (EC-IC) bypass using radial artery graft (n = 3), EC-IC using a saphenous vein graft (n = 7), STA onlay (n = 3), end-to-end anastomosis (n = 1), and in situ bypasses (n = 6). Perioperative stroke occurred in 4 patients, but only one remained dependent (Glasgow Outcome Scale [GOS] score 3). At a mean clinical follow-up of 46 months (median 14 months, range 1-232 months), 26 patients had a good outcome (GOS score 4 or 5). There were no deaths. Five patients had documented occlusion of the bypass graft. The majority of aneurysms (n = 24) were obliterated at last follow-up. There was a single case of a residual aneurysm and one case of recurrence. Angiographic follow-up was unavailable in 3 cases. CONCLUSIONS Cerebral revascularization remains an essential tool in the treatment of complex cerebral aneurysms in children.

Evaluation of Surgical Freedom for Microscopic and Endoscopic Transsphenoidal Approaches to the Sella

BACKGROUND: Microscopic and endoscopic transsphenoidal approaches to the sellar are well established. Surgical freedom is an important skull base principle that can be measured objectively and used to compare approaches. OBJECTIVE: To compare the surgical freedom of 4 transsphenoidal approaches to the sella turcica to aid in surgical approach selection. METHODS: Four transsphenoidal approaches to the sella were performed on 8 silicon-injected cadaveric heads. Surgical freedom was determined with stereotactic image guidance using previously established techniques. The results are presented as the area of surgical freedom and angular surgical freedom (angle of attack) in the axial and sagittal planes. RESULTS: Mean total exposed area surgical freedom for the microscopic sublabial, endoscopic binostril, endoscopic uninostril, and microscopic endonasal approaches were 102 ± 13, 89 ± 6, 81 ± 4, and 69 ± 10 cm2, respectively. The endoscopic binostril approach had the greatest surgical freedom at the pituitary gland and ipsilateral and contralateral internal carotid arteries (25.7 ± 5.4, 28.0 ± 4.0, and 23.0 ± 3.0 cm2) compared with the microscopic sublabial (21.8 ± 3.5, 21.3 ± 2.4, and 19.5 ± 6.3 cm2), microscopic endonasal (14.2 ± 2.7, 14.1 ± 3.2, and 16.3 ± 4.0 cm2), and endoscopic uninostril (19.7 ± 4.8, 22.4 ± 2.3, and 19.5 ± 2.9 cm2) approaches. Axial angle of attack was greatest for the microscopic sublabial approach to the same targets (14.7 ± 1.3°, 11.0 ± 1.5°, and 11.8 ± 1.1°). For the sagittal angle of attack, the endoscopic binostril approach was superior for all 3 targets (16.6 ± 1.7°, 17.2 ± 0.70°, and 15.5 ± 1.2°). CONCLUSION: Microscopic sublabial and endoscopic binostril approaches provided superior surgical freedom compared with the endonasal microscopic and uninostril endoscopic approaches. This work provides objective baseline values for the quantification and evaluation of future refinements in surgical technique or instrumentation. ABBREVIATIONS: cICA, cavernous internal carotid artery pICA, petrous internal carotid artery

Infraorbital nerve: a surgically relevant landmark for the pterygopalatine fossa, cavernous sinus, and anterolateral skull base in endoscopic transmaxillary approaches

OBJECTIVE Endoscopic transmaxillary approaches (ETMAs) address pathology of the anterolateral skull base, including the cavernous sinus, pterygopalatine fossa, and infratemporal fossa. This anatomically complex region contains branches of the trigeminal nerve and external carotid artery and is in proximity to the internal carotid artery. The authors postulated, on the basis of intraoperative observations, that the infraorbital nerve (ION) is a useful surgical landmark for navigating this region; therefore, they studied the anatomy of the ION and its relationships to critical neurovascular structures and the maxillary nerve (V2) encountered in ETMAs. METHODS Endoscopic anatomical dissections were performed bilaterally in 5 silicone-injected, formalin-fixed cadaveric heads (10 sides). Endonasal transmaxillary and direct transmaxillary (Caldwell-Luc) approaches were performed, and anatomical correlations were analyzed and documented. Stereotactic imaging of each specimen was performed to correlate landmarks and enable precise measurement of each segment. RESULTS The ION was readily identified in the roof of the maxillary sinus at the beginning of the surgical procedure in all specimens. Anatomical dissections of the ION and the maxillary branch of the trigeminal nerve (V2) to the cavernous sinus suggested that the ION/V2 complex has 4 distinct segments that may have implications in endoscopic approaches: 1) Segment I, the cutaneous segment of the ION and its terminal branches (5-11 branches) to the face, distal to the infraorbital foramen; 2) Segment II, the orbitomaxillary segment of the ION within the infraorbital canal from the infraorbital foramen along the infraorbital groove (length 12 ± 3.2 mm); 3) Segment III, the pterygopalatine segment within the pterygopalatine fossa, which starts at the infraorbital groove to the foramen rotundum (13 ± 2.5 mm); and 4) Segment IV, the cavernous segment from the foramen rotundum to the trigeminal ganglion (15 ± 4.1 mm), which passes in the lateral wall of the cavernous sinus. The relationship of the ION/V2 complex to the contents of the cavernous sinus, carotid artery, and pterygopalatine fossa is described in the text. CONCLUSIONS The ION/V2 complex is an easily identifiable and potentially useful surgical landmark to the foramen rotundum, cavernous sinus, carotid artery, pterygopalatine fossa, and anterolateral skull base during ETMAs.

Multimodality Management of Vertebral Artery Injury Sustained During Cervical or Craniocervical Surgery

BACKGROUND: Iatrogenic vertebral artery (VA) injury is a rare but potentially devastating complication associated with cervical and craniocervical surgery. OBJECTIVE: To retrospectively evaluate treatment modalities and outcomes associated with iatrogenic VA injury. METHODS: Our institutional surgical database was queried for patients who underwent cervical or craniocervical surgery from January 1997 to August 2012. RESULTS: During this time period, 8213 patients underwent cervical or craniocervical surgery, and 17 (0.2%) cases of VA injury were identified. Eight (47%) of these injuries occurred during C1-2 instrumentation procedures. Primary microsurgical repair of the VA was performed in 5 patients. Other cases were managed by either surgical or endovascular VA occlusion. Of the 17 patients, 15 underwent immediate angiography, 9 of whom were ultimately treated by the use of endovascular techniques. CONCLUSION: VA injury is an uncommon complication of cervical and/or skull base surgery. Standardized management recommendations may help reduce complications associated with these rare but potentially devastating injuries. ABBREVIATIONS: ACDFP, anterior cervical discectomy with fusion and plating CTA, computed tomography angiography PICA, posterior inferior cerebellar artery POD, postoperative day SAH, subarachnoid hemorrhage VA, vertebral artery

Minimally Invasive Endoscopic Supracerebellar-Infratentorial Surgery of the Pineal Region: Anatomical Comparison of Four Variant Approaches

OBJECTIVE The endoscopic supracerebellar-infratentorial (SCIT) approach is a viable method to access pathology of the posterior incisura, but a narrow working space and frequent instrument conflict can potentially limit its surgical efficacy. Until now, no rigorous studies were available comparing surgical freedom and angle of attack for four previously well-described approaches to pineal region targets. METHODS Four formalin-fixed cadaver heads were dissected bilaterally (eight sides). A midline approach and three progressively lateral approaches to the pineal region were performed (paramedian, lateral, extreme lateral), and anatomical targets were identified. Utilizing frameless stereotaxy, we calculated surgical freedom using the vector cross-product method for all approaches for the exposed area and for three anatomical targets (pineal gland, ipsilateral superior colliculus, splenium). The mean and maximum possible angles of attack were calculated in the axial and sagittal planes. RESULTS Point target surgical freedom, exposed area surgical freedom, and angle of attack for each individual pineal region target can be maximized depending on the medial-to-lateral location of the craniotomy. For endoscopic-controlled approaches, the extreme lateral approach provides the largest surgical freedom when accessing the ipsilateral superior colliculus (P < 0.0001), the lateral approach provides the largest surgical freedom to the pineal gland (P < 0.0001), and the paramedian craniotomy provides the largest surgical freedom when accessing the splenium (P < 0.0001). The extreme lateral approach to the pineal gland provided the largest horizontal angle of attack (P < 0.0001), and the extreme lateral approach to the ipsilateral superior colliculus provided the largest vertical angle of attack (P < 0.001). The microscope provides marginally increased surgical freedom and a better angle of attack to specific anatomical targets in the paramedian and extreme lateral approach compared with those provided by the endoscope, but these differences are negligible during intraoperative application. CONCLUSIONS Presurgical planning and a detailed understanding of the important neurovascular structures in the pineal region are paramount to safe and successful surgical execution. Our current cadaveric study indicates that the medial-to-lateral location of craniotomy can maximize access to pineal region targets. Furthermore, the endoscope is a viable alternative to the microscope for identifying pathology of the posterior incisura. These differences in surgical freedom and angle of attack to the pineal region may be useful to consider when planning minimal-access approaches.

The journey of discovering skull base anatomy in ancient Egypt and the special influence of Alexandria.

The field of anatomy, one of the most ancient sciences, first evolved in Egypt. From the Early Dynastic Period (3100 BC) until the time of Galen at the end of the 2nd century ad, Egypt was the center of anatomical knowledge, including neuroanatomy. Knowledge of neuroanatomy first became important so that sacred rituals could be performed by ancient Egyptian embalmers during mummification procedures. Later, neuroanatomy became a science to be studied by wise men at the ancient temple of Memphis. As religious conflicts developed, the study of the human body became restricted. Myths started to replace scientific research, squelching further exploration of the human body until Alexander the Great founded the city of Alexandria. This period witnessed a revolution in the study of anatomy and functional anatomy. Herophilus of Chalcedon, Erasistratus of Chios, Rufus of Ephesus, and Galen of Pergamon were prominent physicians who studied at the medical school of Alexandria and contributed greatly to knowledge about the anatomy of the skull base. After the Royal Library of Alexandria was burned and laws were passed prohibiting human dissections based on religious and cultural factors, knowledge of human skull base anatomy plateaued for almost 1500 years. In this article the authors consider the beginning of this journey, from the earliest descriptions of skull base anatomy to the establishment of basic skull base anatomy in ancient Egypt.

Carotid Endarterectomy Surgical Simulation Model Using a Bovine Placenta Vessel.

BACKGROUND Carotid endarterectomy (CEA) is a common, well-developed surgical procedure. Although surgical simulation is gaining in importance for residency training, CEA practice opportunities for surgical residents are limited. OBJECTIVE To describe a new haptic CEA model. METHODS Six bovine placentas were used to create the model. Each placenta provided about 6 large arterial and venous bifurcations. In total, 36 large-vessel bifurcations were dissected and prepared for the CEA simulation. Bovine placenta vessels were arranged to simulate the common carotid artery (CCA), internal carotid artery (ICA), and external carotid artery (ECA). The diameters and wall thicknesses were measured and compared with human CCA, ICA, and ECA parameters. RESULTS All bovine placentas provided vessels suitable for modeling carotid artery bifurcations and CEA training. Mean ± SD diameters of simulated CCAs, ECAs, and ICAs were 11.2 ± 1.8, 4.3 ± 0.5, and 9.8 ± 3.0 mm, respectively, from nondilated veins and 8.7 ± 1.4, 4.4 ± 1.3, and 7.2 ± 1.7 mm, respectively, from nondilated arteries. Mean vessel wall thicknesses were 2.0 ± 0.6 mm for arteries and 1.4 ± 0.5 mm for veins. Placental vessel tissue had dimensions and handling characteristics similar to those of human carotid arteries. The CEA procedure and its subtasks, including vessel-tissue preparation and surgical skills performance, could be reproduced with high fidelity. CONCLUSION A bovine placenta training model for CEA is inexpensive and readily available and closely resembles human carotid arteries. The model can provide a convenient and valuable simulation and practice addition for vascular surgery training.