bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microsurgical Anatomy Of The Oculomotor Cistern
Authors: Martins Carolina , Yasuda Alexandre , Campero Alvaro , Rhoton Albert L. 
Published: April 2006

Abstract

Objective:
To define the characteristics of the arachnoidal sleeve and cistern that accompany the oculomotor nerve through the cavernous sinus roof.

Methods:
Forty cavernous sinuses were examined using 3 to 40x magnification. Information was obtained about the size of the oculomotor cistern and its relationship to the roof of the cavernous sinus and anterior clinoid process.

Results:
An arachnoidal sleeve and cistern, referred to as the oculomotor cistern, accompanied the oculomotor nerve into the roof of all the cavernous sinuses examined. The oculomotor cistern extends from the oculomotor porus, where the nerve enters the roof of the cavernous sinus, to the area below the tip or the adjacent part of the lower margin of the anterior clinoid process. From the porus, the nerve passes forward and downward to the depth of the cistern where it becomes incorporated into the fibrous lateral wall of the cavernous sinus. The width of the cistern was maximal at the oculomotor porus averaged 5.5 mm (range, 3.0–9.2 mm), and tapered slightly towards the midpoint and deep end of the cistern. The cistern's average length was 6.5 mm (range, 3.0–11.0 mm). The oculomotor nerve usually coursed closer to the anterior than the posterior wall of the cistern at the level of the oculomotor porus.

Conclusion:
The oculomotor cistern, an arachnoidal and dural cuff, accompanies the oculomotor nerve through the cavernous sinus roof to the area just below or anterior to the lower edge of the tip of the anterior clinoid process. The segment of the nerve inside the oculomotor cistern is interposed between its free portion in the interpeduncular cistern and the part of its course where it is incorporated into the fibrous lateral wall of the cavernous sinus. The cistern can be opened to aid in the exposure and mobilization of the nerve in dealing with pathology in the area.
Surgical Anatomy Of Dural Defects In Spontaneous Spinal Cerebrospinal Fluid Leaks
Authors: Cohen-Gadol Aaron A. , Mokri Bahram , Piepgras David G. , Meyer Fredric B. , Atkinson John L.D. 
Published: April 2006

Abstract

Objective:
Spontaneous intracranial hypotension is typically caused by a spontaneous spinal cerebrospinal fluid (CSF) leak. The configuration of the related dural defects can be complex. We describe our experience with the surgical anatomy of these defects.

Methods:
Thirteen consecutive patients with spontaneous spinal CSF leaks who underwent surgical exploration at Mayo Clinic between 1994 and 2003 were studied. All patients' records, imaging studies, detailed intraoperative findings, and outcomes were reviewed.

Results:
There were four men and nine women with an average age of 40 years (range, 12–62 yr). Preoperative imaging studies revealed a single site of CSF leak in eight patients, two sites in three patients, and multiple sites in two patients. Intraoperatively, the exact site of leakage could not be found in four patients. Among the other nine patients, primary closure of a meningeal diverticulum was achieved in one patient. Significant regional attenuation of the dura prevented primary repair of the leak site in eight patients. Muscle, fibrin glue, and Gelfoam (Upjohn Co., Kalamazoo, MI) soaked in patient's own blood were commonly used to pack the epidural space in an attempt to seal the site of the leak. Ligation of two nonappendicular nerve roots allowed closure of the leak in one of these patients. Postoperatively, resolution of symptoms occurred in eight patients, significant improvement was noted in three patients, and only transient resolution in two. The mean duration of follow-up was 20.5 months.

Conclusion:
Surgery for closure of spontaneous spinal CSF leaks may not be straightforward. Even when extradural CSF leakage is discovered preoperatively by imaging studies, it may not always be possible to identify the exact site of the leakage intraoperatively. Furthermore, the anatomy of the dural defects may be complex and not amenable to primary closure. In such cases, the use of adjuvant techniques during surgical exploration may be effective.
Intra/Extra-Aneurysmal Stent Placement For Management Of Complex And Wide-Necked-Bifurcation Aneurysms:Eight Cases Using The Waffle Cone Technique
Authors: Horowitz Michael , Levy Elad , Sauvageau Eric , Genevro Julie , Guterman Lee R. , Hanel Ricardo , Wehman Christopher , Gupta Rishi , Jovin Tudor 
Published: April 2006

Abstract

Objective:
To describe a novel application of the Neuroform stent (Boston Scientific-Target, Fremont, CA) for the management of eight wide-necked aneurysms.

Methods:
All patients were treated using a single Neuroform stent placed partially into the aneurysm and into the afferent artery. The portion of the stent protruding into the aneurysm fundus provided neck support for the subsequent successful coiling.

Conclusion:
The Neuroform stent is a versatile device that can be used in a variety of ways to assist in the coiling of wide-necked aneurysms. The technique described here may be used for bifurcation aneurysms in lieu of using two stents in a Y configuration.
Intraoperative Magnetic Resonance Imaging-guided neurosurgery at 3-T
Authors: Truwit Charles L. , Hall Walter A. 
Published: April 2006

Abstract

Objective:
Between 1997 and 2004, more than 700 neurosurgical procedures were performed in a 1.5-T magnetic resonance-guided therapy suite. During this period, the concept of high-field intraoperative magnetic resonance imaging (MRI) was validated, as was a new surgical guidance tool, the Navigus (Image-guided Neurologics, Melbourne, FL), and its methodology, prospective stereotaxy. Clinical protocols were refined to optimize surgical techniques. That implementation, the “Minnesota suite, ” has recently been revised, and a new suite with a 3-T MRI scanner has been developed.

Methods:
On the basis of experience at the initial 1.5-T suite, a new suite was designed to house a 3-T MRI scanner with wide surgical access at the rear of the scanner (opposite the patient couch). Use of electrocautery, a fiberoptic headlamp, a power drill, and MRI-compatible neurosurgical cutlery was anticipated by inclusion of waveguides and radiofrequency filter panels that penetrate the MRI suite's radiofrequency shield. An MRI-compatible head holder was adapted for use on the scanner table. A few items exhibiting limited ferromagnetism were used within the magnetic field, taking strict precautions.

Results:
During the initial procedures (all magnetic resonance-guided neurobiopsies), the new suite functioned as anticipated. Although metallic artifact related to titanium needles is more challenging at 3 T than at 1.5 T, it can be contained even at 3 T. Similar to 1.5 T, such artifact is best contained when the device is oriented along B0, the main magnetic field. Surgical needles, disposable scalpels, and disposable razors, despite being minimally ferromagnetic, were easily controlled by the surgeon.

Conclusion:
An intraoperative magnetic resonance-guided neurosurgical theater has been developed with a 3-T MRI scanner. Intraoperative imaging is feasible at this field strength, and concerns regarding specific absorption rate can be allayed. Infection control procedures can be designed to permit neurosurgery within this environment. Despite the increase in magnetic field strength, safety can be maintained.
Anterior Cervical Discectomy and Corpectomy
Authors: Perez-Cruet Mick J. , Samartzis Dino , Fessler Richard G. 
Published: April 2006

Abstract

Objective:
The objective of this review article is to describe the authors' operative technique for performing anterior cervical corpectomy and fusion.

Methods:
The authors reviewed their operative technique and experience to clearly detail the general methods utilized to safely and effectively perform anterior cervical corpectomy and fusion. Specific nuances peculiar to the authors' technique were identified and highlighted.

Results:
The operative technique for anterior cervical corpectomy, including nuances for enhancing ease or outcome of surgery, is described in detail. Drawings and photographs are included where appropriate to highlight specific aspects of the procedural technique.

Conclusion:
Anterior cervical corpectomy and fusion is a well known technique that proceeds in a consistent and logical sequence of maneuvers. Specific technical nuances at various points enhance the ease and safety of the technique, as well as the completeness of the eventual result.
Increased Cell Opening and Prolapse of Struts of a Neuroform Stent in Curved Vasculature:Value of Angiographic Computed Tomography: Technical Case Report
Authors: Benndorf Goetz , Claus Benjamin , Strother Charles M. , Chang Lee , Klucznik Richard P. 
Published: April 2006

Abstract

Objective and Importance:
To describe the use of a new imaging tool, angiographic computed tomography, for visualization of cell opening and strut prolapse of a Neuroform 2 stent (Boston Scientific/Target, Fremont, CA) placed in curved vasculature for treatment of a basilar tip aneurysm.

Clinical Presentation:
A 46-year-old woman presented with an unruptured 8-mm basilar tip aneurysm with a wide patulous neck.

Intervention:
A 4 × 20-mm Neuroform 2 stent was placed across the aneurysm neck. Angiographic computed tomographic scanning was performed using a flat detector biplane angiographic system with new commercially available software (Dyna-CT; Siemens Medical Solution, Forchheim, Germany) and the following parameters: 20-second acquisition, 0.4-degree increment, 512 matrix in projections, 220-degree total angle, 20 degree/s, and approximately 15 to 30 frames/s, for a total of 538 projections. Image postprocessing was performed to correct scattered radiation, beam hardening, and ring artifacts on a commercially available workstation (Leonardo, Siemens Medical Solutions, Erlangen, Germany). The aneurysm was coiled in a second session, using bare platinum coils without clinical sequelae.

Conclusion:
Increased opening of cells and prolapsing of struts of an open cell design stent can occur after placement in a curved vessel across an aneurysm orifice. Angiographic computed tomography is a new imaging tool that provides visualization of intracranial stents that is superior to digital subtraction angiogram or nonsubtracted images. It will enhance our understanding of stent behavior in clinical practice and improve the efficacy and safety of intracranial stent placement. Further in vitro and in vivo imaging studies of intracranial stents are necessary to assess the value of this promising new technique.
Simultaneous Image-guided and Endoscopic Navigation without Rigid Cranial Fixation: Application in Infants:Technical Case Report
Authors: Mangano Francesco T. , Limbrick David D. , Leonard Jeffrey R. , Sung Park Tae , Smyth Matthew D. 
Published: April 2006

Abstract

Objective and Importance:
Infants and young children demonstrate a variety of intraventricular and periventricular lesions. Endoscopy has proven useful in the treatment of many of these lesions, but its benefit is limited if it is applied to complex loculated cysts or if the disease is concealed by normal ependymal boundaries. In adults and older children, endoscopy can be augmented by the simultaneous use of frameless stereotaxy, but this combined modality has not been possible in infants and young children without rigid cranial fixation. We describe a method of achieving simultaneous stereotactic and endoscopic navigation in infants and young children by using a pinless, frameless stereotactic assembly.

Clinical Presentation:
The first patient was a 6-week-old boy with macroceph-aly and a bulging fontanelle. Computed tomographic and magnetic resonance imaging revealed a complex arachnoid cyst and obstructive hydrocephalus. The second patient was a 7-month-old, ex-premature (27-wk gestational age) boy who developed posthemorrhagic hydrocephalus. He underwent multiple shunt revisions, one of which was complicated by enterococcal ventriculitis. Despite bilateral ventriculoperitoneal shunts, he developed increasing head circumference, listlessness, and irritability. Imaging revealed an enlarged, multiloculated, and asymmetric ventricular system.

Intervention:
Simultaneous image-guided and endoscopic neuronavigation was implemented in both patients. Before the procedure, a cranial reference arc was secured to the outer table of the cranium through a small incision adjacent to the operative field. After the stereotactic apparatus was registered, the software was used to plan a trajectory for the approach. A burr hole was then made, and a rigid 6-mm endoscope was inserted for direct visualization. Once advanced past the endoscopic port tip, the electromagnetic coil stylet was used to stereotactically track position and identify areas for fenestration, biopsy, and catheter insertion.

Conclusion:
Endoscopic views of complex hydrocephalus and arachnoid cysts alone are often difficult to interpret. Simultaneous image-guided and endoscopic neuronavigation may be advantageous in the management of complex cases that are anatomically related to the ventricular system in infants for whom rigid cranial fixation could lead to increased procedure-related morbidity.
Surgical Management of Distal Coil Migration and Arterial Perforation after Attempted Coil Embolization of a Ruptured Ophthalmic Artery Aneurysm:Technical Case Report
Authors: Deshmukh Vivek R. , Klopfenstein Jeffrey , Albuquerque Felipe C. , Kim Louis J. , Spetzler Robert F. 
Published: April 2006

Abstract

Objective and Importance:
Distal coil migration is a rare but hazardous complication of aneurysm coil embolization. Various microsnare devices have been developed to address this problem. We describe the surgical management of a case in which microsnare retrieval failed.

Clinical Presentation:
A 34-year-old woman presented with subarachnoid hemorrhage. Magnetic resonance imaging, computed tomography angiography, and conventional angiography showed an approximately 2.5-mm ophthalmic artery aneurysm. Using balloon remodeling, a 2 × 4-cm coil was deployed into the aneurysm fundus. While the coil pusher was being removed after deployment, the microcatheter advanced abruptly into the aneurysm. The coil mass was dislodged and migrated into the angular branch of the middle cerebral artery. Contrast extravasation was noted during attempted retrieval with a microsnare device.

Technique:
Computed tomographic scans showed a subarachnoid hemorrhage in the territory of the left frontotemporal operculum. A left modified orbitozygomatic approach was performed. The coil mass was removed from the angular artery and a thromboembolectomy was performed. The artery was repaired and the pseudoaneurysm was clip ligated. The ophthalmic artery aneurysm was clip ligated. The patient recovered without deficits.

Conclusion:
Distal coil migration and arterial perforation can be treated surgically with a good clinical outcome.
Quantification And Comparison Of Telovelar And Transvermian Approaches To The Fourth Ventricle
Authors: Deshmukh Vivek R. , Figueiredo Eberval Gadelha , Deshmukh Puspha , Crawford Neil R. , Preul Mark C. , Spetzler Robert F. 
Published: April 2006

Abstract

Objective:
To quantify the exposure to the fourth ventricle obtained with the telovelar and transvermian approaches.

Methods:
The telovelar, with and without C1 posterior arch removal, and transvermian approaches were performed on six cadaveric heads. The area of surgical exposure was calculated from triangles formed by defined anatomic points. A robotic microscope was used to determine the “angle of approach” for the same points.

Results:
The maximal allowable vertical angle of attack to the obex of the fourth ventricle was significantly greater with the telovelar approach than with the transvermian approach (P &lt; 0.002), but there was no difference at the rostral fourth ventricle. The maximal allowable horizontal angle of attack at the level of the obex, Luschka, and rostral fourth ventricle was significantly greater with the telovelar than with the transvermian approach (P &lt; 0.001). Removal of the C1 posterior arch with the telovelar approach significantly increased the vertical angle of approach to the obex (P &lt; 0.001) and rostral aspect of the fourth ventricle (P = 0.005) compared with the telovelar alone. The telovelar approach with C1 arch removal offered a larger working area than the transvermian approach (P &lt; 0.001).

Conclusion:
Except for the vertical angle to the rostral aspect of the fourth ventricle, the telovelar approach provides greater angle of exposure in all planes than the transvermian approach. Removal of the C1 posterior arch obviates this sole advantage of the transvermian approach. The telovelar approach offers a corridor through noneloquent arachnoid planes and a safe and capacious working environment.
Minimally Invasive Atlantoaxial Fixation with a Polyaxial Screw-rod Construct: Technical Case Report
Authors: Joseffer Seth S. , Post Nicholas , Cooper Paul R. , Frempong-Boadu Anthony K. 
Published: April 2006

AbstractObjective and Importance:Posterior C1–C2 fusion with polyaxial screw and rod fixation has become an accepted means of atlanto-axial stabilization. We describe a novel technique for minimally invasive placement of C1 lateral mass screws and C2 pedicle screws for polyaxial screw-rod stabilization.Clinical Presentation:The patient presented with a history of chronic neck pain, as well as a 6-month history of weakness and paresthesias involving her left hand. An Os Odontoideum was present on computed tomographic imaging of the cervical spine. Significant instability was noted on flexion-extension imaging, and magnetic resonance imaging demonstrated mild T2 signal change within the spinal cord.Technique:Under fluoroscopic guidance, serial dilators were passed through a 2.5 cm paramedian skin incision to allow placement of an expandable tubular retractor. The exposure was centered on the C2 lateral mass. After expansion of the retractor and further subperiosteal dissection, the C1 and C2 lateral masses were visible permitting placement of a polyaxial screw rod construct. This procedure was carried out bilaterally.Conclusion:Placement of C1 lateral mass and C2 pedicle screws using minimally invasive techniques is technically feasible.
Two-stage Operation for Resection of Spinal Cord Astrocytomas:Technical Case Report of Three Cases
Authors: Hida Kazutoshi , Iwasaki Yoshinobu , Seki Toshitaka , Yano Shunsuke 
Published: April 2006

Abstract

Objective and Importance:
Surgery for excision of intramedullary spinal cord tumors without increasing neurological deficit is one of the more difficult operations in spinal surgery. In particular, infiltrating astrocytomas without a clear cleavage between the tumor and normal spinal cord parenchyma are difficult to remove totally without producing additional neurological impairment. In this study, we describe a two-stage resection facilitating total resection of intramedullary tumors.

Clinical Presentation:
Three cases of spinal cord astrocytomas were treated using a two-staged method.

Technique:
The first surgery included myelotomy, biopsy and duroplasty. A thin expanded polytetrafluoroethylene sheet was placed between the dorsal surface of the spinal cord and dura mater to prevent adhesions. Two or 3 weeks after surgery, a second surgery was performed to remove the now exophytic tumor.

Results:
Magnetic resonance imaging scans showed exophytic extrusion of the tumor in all three cases before the second operation. In each patient, we were able to carry out gross total removal of the tumors without additional neurological deficit except for transient joint position sense loss in one case. All three patients remain neurologically stable without evidence of tumor recurrence more than 3 years after surgery.

Conclusion:
A two-stage operation may enhance the surgeon's ability to completely resect extensive low-grade spinal cord astrocytomas and, at the same time preserve neurological function.
Subpectoral Implantation of the Vagus Nerve Stimulator
Authors: Bauman Joel A. , Ridgway Emily B. , Devinsky Orrin , Doyle Werner K. 
Published: April 2006

AbstractObjective:To report the technique of subpectoral (SP) implantation of the vagus nerve stimulator (VNS) generator.Methods:We retrospectively reviewed and compared demographics and complications from patients receiving either subcutaneous (SQ; n = 107) or SP (n = 138) VNS implants, performed by one surgeon (WKD) between 1999 and 2003. Selection of implant location was made during the preoperative surgeon-patient consultation on the basis of surgeon recommendation and patient preference.Results:The standard VNS generator implantation is performed within a SQ pocket in the left infraclavicular region of the chest. We have modified this technique by placing the generator into a deeper pocket SP, beneath the pectoralis major muscle, while tunneling the electrodes SQ in the usual fashion. The SP group was substantially younger (median age 19 yr) compared with the SQ group (median age 29 yr). At an average follow-up of 52 months for SQ implants and 28.4 months for SP implants, there were 2.9% infections per patient in the SQ group and 2.5% infections per patient in the SP group. There were three cases of excessive generator mobility in the SQ group; no cases occurred in the SP group.Conclusion:The SP implantation technique provides an attractive alternative to SQ VNS implantation. With increased soft tissue coverage, we provide improved cosmesis, increased wound durability to tampering and trauma, and a comparable infection rate with the SQ group.
Double Reimplantation Technique to Reconstruct Arterial Bifurcations with Giant Aneurysms
Authors: Lawton Michael T. , Quiñones-Hinojosa Alfredo 
Published: April 2006

Abstract

Objective:
To introduce the double implantation technique, a variation of standard radial artery or saphenous vein bypass that can be used to reconstruct arterial bifurcations in the management of giant aneurysms with complex branch arteries.

Methods:
This technique was applied in two patients with giant aneurysms. A 74-year-old woman presented with a ruptured thrombotic middle cerebral artery aneurysm, and a 24-year-old man presented with an enlarging infectious aneurysm of the distal anterior cerebral artery (ACA).

Results:
In the first case, a saphenous vein graft was anastomosed end-to-end to the external carotid artery. The temporal M2 middle cerebral artery trunk was disconnected from the aneurysm and reimplanted onto the graft with an end-to-side anastomosis. The graft was anastomosed end-to-side to the frontal M2 middle cerebral artery trunk, and the aneurysm was trapped. Similarly, in the second case, a radial artery graft was connected to a proximal ACA branch (anterior internal frontal artery) and to the distal pericallosal artery, with reimplantation of the callosomarginal artery onto the graft. The aneurysm was occluded proximally with a clip.

Conclusion:
The combination of two arterial reimplantations onto a bypass graft connected to a proximal donor artery (3 anastomoses overall) reconstructs an arterial bifurcation and enables the exclusion of a giant aneurysm. Ischemia times are minimized by completing the proximal anastomosis first, successively reimplanting efferent arterial trunks distally, and restoring cerebral perfusion to reimplanted arteries while other anastomoses are performed. This technique may be indicated when critical efferent arteries require revascularization, conventional donor arteries are diminutive, the aneurysm has ruptured, or intraluminal thrombus requires debulking.
Anterior Supraclavicular Approach to the Brachial Plexus
Authors: Tender Gabriel C. , Kline David G. 
Published: April 2006

Abstract
The anterior supraclavicular approach to the brachial plexus is commonly indicated in patients with traumatic injuries, tumors, or entrapment of the brachial plexus elements. We describe the anatomy and operative technique of this approach, which has been used by the senior author (DGK) for the past 30 years.