bluuebunny/crossref_metadata_2025_split huggingface dataset:
TPO/Mpl Studies in Agnogenic Myeloid Metaplasia
Authors: Hemavathy Kirugaval C , Suppiah Kathir , Hashmi Gazala , Novetsky Allan D , Wang Jen C 
Published: February 2005

Abstract
Background
Agnogenic myeloid metaplasia (AMM) is one of the Philadelphia chromosome negative myeloproliferative disorder and is diagnosed by hyperplasia of atypical megakaryocytes, hepatosplenomegaly, extramedullary hematopoiesis and bone marrow fibrosis. Fibrosis is considered to be a secondary consequence of enhanced levels of fibrogenic growth factors such as TGF β1, bFGF and PDGF produced by enhanced numbers of megakaryocytes, while the primary cause is considered to be the enhanced proliferation of a defective stem cell. We have previously reported that thrombopoietin (TPO) is elevated in patients with AMM. Others have reported that Mpl protein is decreased in these patients. Since TPO is essential for the development of megakaryocytes, and Mpl protein is the receptor for TPO, we extended the study of TPO/Mpl to in vitro and in vivo cell culture systems to better understand the mechanism that leads to reduced Mpl protein in AMM patients.

Results
Plasma TPO levels were significantly elevated and Mpl protein levels were significantly reduced in AMM patients in concordance with previous studies. Platelet Mpl transcripts in AMM were however similar to those in controls. We also cloned Mpl cDNA from AMM patients and tested for their ability to make functional proteins in vitro and in the in vivo system of 293 T human embryonic kidney cells. Their expression including the glycosylated forms was similar to those from the controls. We also measured the level of translation initiation factor, eIF4E and found it to be increased in patients with AMM demonstrating that the reduced Mpl protein may not be due to translation defects.

Conclusions
Our studies using the in vitro and in vivo systems further confirm that reduced Mpl protein levels are not due to defects in its transcription/translation. Reduced Mpl protein could be due to its increased internalisation owing to enhanced plasma TPO or in vivo intrinsic defects in patients with AMM.
The Cut Flow Index: An Intraoperative Predictor of the Success of Extracranial-Intracranial Bypass for Occlusive Cerebrovascular Disease
Authors: Amin-Hanjani Sepideh , Du Xinjian , Mlinarevich Nada , Meglio Guido , Zhao Meide , Charbel Fady T. 
Published: February 2005

Abstract

OBJECTIVE:
There has been a resurgence of interest in selective extracranial-intracranial bypass for revascularization of cerebrovascular occlusive disease. We evaluated the usefulness of intraoperative blood flow measurements in predicting graft success after extracranial-intracranial bypass.

METHODS:
A retrospective review of 51 cases of extracranial-intracranial bypass for purposes of flow augmentation in the setting of cerebrovascular occlusive disease was performed. In all cases, free flow from the cut end of the donor vessel, termed cut flow, was measured. The cut flow index (CFI) (bypass flow [ml/min] / cut flow [ml/min]) was derived and correlated with bypass patency, postoperative bypass flow, cerebrovascular reserve testing, and clinical outcome.

RESULTS:
The CFI was a significant predictor of bypass patency (P = 0.002). Using a CFI of 0.5 as a threshold, the bypass patency rate was 92% in cases with a CFI greater than 0.5 compared with 50% in cases with a CFI less than 0.5. Intraoperative bypass flow correlated well with postoperative measurements obtained from quantitative phase-contrast magnetic resonance imaging. An analysis of cases with a poor CFI indicated that a logical interpretation of bypass function can be performed during surgery.

CONCLUSION:
A poor CFI can alert surgeons to potential difficulties with the donor vessel, anastomosis, or recipient vessel during surgery. Furthermore, a CFI closely approximating 1.0 provides physiological confirmation of impaired cerebrovascular reserve in the recipient bed.
Surgical Exposure of the Sciatic Nerve in the Gluteal Region: Anatomic and Historical Comparison of Two Approaches
Authors: Patil Parag G. , Friedman Allan H. 
Published: February 2005

Abstract

OBJECTIVE:
To increase awareness among neurosurgeons of alternative surgical approaches to lesions of the sciatic nerve in the gluteal region.

METHODS:
The dominant surgical approach to lesions of the proximal sciatic nerve involves detachment and medial reflection of the gluteus maximus through a question-mark incision. An alternative to this infragluteal exposure is a transgluteal approach, which provides access to the sciatic nerve by splitting the gluteus maximus through a curvilinear incision. We explored the anatomy and surgical history of these approaches through cadaveric study, our own case series, and a literature review.

RESULTS:
The infragluteal approach uses a larger incision, extensive dissection, and postoperative bracing while allowing wide exposure of the nerve inferiorly into the thigh. By contrast, the transgluteal approach minimizes dissection and spares muscle attachments but requires meticulous attention to hemostasis and provides a more focal exposure of the sciatic nerve. During the past century, the infragluteal approach has been described more frequently and has become increasingly popular among peripheral-nerve surgeons. For comparison, we present three patients in whom the transgluteal approach was used to treat substantial lesions of the proximal sciatic nerve.

CONCLUSION:
At the present time, the majority of peripheral nerve surgeons use an infragluteal approach to the proximal sciatic nerve. However, for select patients with well-defined and localized lesions, the transgluteal approach may provide sufficient nerve exposure with lowered operative complexity and postoperative morbidity.
Using Dermabond for Wound Closure in Lumbar and Cervical Neurosurgical Procedures
Authors: Hall Lance T. , Bailes Julian E. 
Published: February 2005

AbstractOBJECTIVE:2-Octylcyanoacrylate (Dermabond; Ethicon, Inc., Somerville, NJ) is a liquid adhesive being used with increasing frequency for the closure of lacerations and surgical incisions. Dermabond provides excellent cosmetic closure, and recent studies have demonstrated very low infection risks when it is properly applied. There are no published studies using Dermabond on lumbar or cervical procedures. This study was undertaken to determine whether Dermabond is safe and efficacious to use in these common neurosurgical procedures.METHODS:Records of 200 consecutive patients with Dermabond closure after anterior cervical discectomy, microlumbar discectomy, or lumbar laminectomy by the senior author (JEB) with a mean follow-up time of 5.42 months were retrospectively reviewed. Suspected infections with or without confirmatory cultures, erythema, and incisional drainage were documented.RESULTS:Of 200 patients, 85 underwent microlumbar discectomy, 22 lumbar laminectomy, and 93 anterior cervical discectomy. There was only 1 definitive infection, which was a culture-proven discitis in a microlumbar discectomy patient. Of the remaining 85 microlumbar discectomies, there was 1 transient incisional erythema. Of the 22 lumbar laminectomies, there was 1 patient with clinical superficial wound infection with negative cultures and 4 patients with transient incisional drainage without infection. Of the 93 anterior cervical discectomies, 2 had transient incisional drainage without infection.CONCLUSION:This study demonstrates that Dermabond is safe to use in neurosurgery patients undergoing lumbar or cervical procedures, with only 1 patient of 200 having a proven infection. Patients are able to shower and do not have sutures or staples to remove. Patient responses are overwhelmingly positive.
Pars Screw Fixation of a Hangman's Fracture: Technical Case Report
Authors: Bristol Ruth , Henn Jeffrey S. , Dickman Curtis A. 
Published: February 2005

Abstract

OBJECTIVE AND IMPORTANCE:
Traumatic spondylolisthesis of the axis may be treated by external immobilization or surgical fixation.

CLINICAL PRESENTATION:
We report the case of a 23-year-old man who sustained an Effendi Type II fracture of the axis, for which halo immobilization did not provide adequate stability.

INTERVENTION:
The unstable fracture was treated by placing lag screws in the pars interarticularis of C2, which reduced the fracture directly but sacrificed no normal spinal motion. The patient developed a solid fusion, and cervical alignment was normal at his 6-month follow-up examination.

CONCLUSION:
Although this technique has been reported previously, it is more commonly used in multilevel cervical fusions than for stand-alone repair of C2. Management options, anatomy, and technical considerations for the treatment of traumatic spondylolisthesis are reviewed.
Cervicothoracic Junction Arthroplasty after Previous Fusion Surgery for Adjacent Segment Degeneration: Case Report
Authors: Sekhon Lali H.S. 
Published: February 2005

Abstract

OBJECTIVE AND IMPORTANCE:
This is the first reported case of cervical arthroplasty using the Bryan Cervical Disc Prosthesis System (Medtronic Sofamor Danek, Inc., Memphis, TN) in the management of adjacent segment degeneration associated with previous fusion surgery and surgery at the cervicothoracic junction.

CLINICAL PRESENTATION:
This case report describes a 25-year-old woman who initially underwent a two-level anterior cervical fusion in 1998, 2 years after being involved in a motor vehicle accident. She was well until 18 months before presentation, when she developed bilateral shoulder pain, mechanical neck pain worse on flexion, and bilateral C8 distribution arm pain and paresthesia. On clinical examination, no focal deficits were found, although the range of motion was reduced. Preoperative cervical spine x-rays and magnetic resonance scanning confirmed accelerated degeneration of the C4–C5 and C7–T1 disc spaces, with evidence of neural compression at those levels.

INTERVENTION:
After careful consideration of various treatment options and failure of all conservative measures, the patient underwent an anterior C4–C5 and C7–T1 decompression with removal of the anterior cervical plate and placement of two artificial disc prostheses. After surgery, her course was uncomplicated and she was discharged from hospital well. There was complete resolution of the arm symptoms and reduction of the neck pain, with a reduction in the amount of analgesia she was taking. Seven months after surgery, she remains well with repeat x-rays confirming motion at the operated levels.

CONCLUSION:
This case demonstrates that cervical arthroplasty is a reasonable treatment option for patients who have had previous surgery in which interbody fusion has been performed and who have developed degeneration of adjacent levels. Despite the altered biomechanics at the cervicothoracic junction, no adverse features were noted with arthroplasty at this level.
Exposure of Midline Cranial Base without a Facial Incision through a Combined Craniofacial-Transfacial Procedure
Authors: Feiz-Erfan Iman , Han Patrick P. , Spetzler Robert F. , Porter Randall W. , Klopfenstein Jeffrey D. , Ferreira Mauro A.T. , Beals Stephen P. , Joganic Edward F. 
Published: February 2005

AbstractOBJECTIVE:A single-stage combined craniofacial-transfacial approach that exposes the midline cranial base without visible facial incisions is described.METHODS:Between 1992 and 1998, eight patients underwent surgery for five different anterior cranial base pathological findings: four angiofibromas, one mesenchymal chondrosarcoma, one esthesioneuroblastoma, one odontogenic myxoma, and one encephalocele. In all cases, the surgical exposure consisted of a bicoronal scalp incision with a bifrontal craniotomy and fronto-orbitonasal osteotomy, and then a sublabial incision for transmaxillary exposure.RESULTS:Gross total resection was achieved in five cases. The encephalocele was resected with complete reconstruction of the bony defect. Seven patients developed complications, primarily wound infections, cerebrospinal fluid leaks, and anemia. Postoperative Karnofsky Performance Scale scores ranged between 80 and 100 (mean, 92.5). Long-term follow-up information (mean, 56 mo; median, 59.5 mo; range, 5–108 mo) was available for all patients.CONCLUSION:Large anterior cranial base lesions can be resected and excellent cosmetic outcomes can be achieved with a single-stage combined transfacial-craniofacial approach that exposes the entire midline cranial base and requires no facial incisions.
Reconstruction Options for Complex Middle Cerebral Artery Aneurysms
Authors: Sekhar Laligam N. , Stimac Dinko , Bakir Abdurrahman , Rak Ramin 
Published: February 2005

Abstract

OBJECTIVE:
To describe techniques of reconstruction for unclippable and uncoilable middle cerebral artery aneurysms.

METHODS:
A retrospective review was performed of seven patients who underwent eight operations during a 9-year period to treat complex middle cerebral artery bifurcation aneurysms not amenable to direct clipping or endovascular coiling. All preoperative and postoperative clinical and imaging data were reviewed. Follow-up was obtained for all patients via clinic visit and/or telephone.

RESULTS:
The operative techniques used included saphenous vein graft bypass (n = 1), radial artery graft interposition (n = 2), radial artery patch (n = 1), superficial temporal artery interposition graft (n = 1), superior thyroid artery interposition graft (n = 1), direct reimplantation of branch (n = 1), and reconstruction of trifurcation (n = 1). There was no mortality. Six patients had excellent outcomes with Glasgow Outcome Scale scores of 5, and one patient had a good outcome with a Glasgow Outcome Scale score of 4.

CONCLUSION:
Techniques for middle cerebral artery reconstruction may remain important and useful in the age of endovascular aneurysm treatment.
Sequential Visualization of Brain and Fiber Tract Deformation during Intracranial Surgery with Three-dimensional Ultrasound: An Approach to Evaluate the Effect of Brain Shift
Authors: Coenen Volker A. , Krings Timo , Weidemann Jürgen , Hans Franz-Josef , Reinacher Peter , Gilsbach Joachim M. , Rohde Veit 
Published: February 2005

Abstract

OBJECTIVE:
We present a technique that allows intraoperative display of brain shift and its effects on fiber tracts.

METHODS:
Three patients had intracranial lesions (one malignant glioma, one metastasis, and one cavernoma) in contact with either the corticospinal or the geniculostriate tract that were removed microneurosurgically. Preoperatively, magnetic resonance diffusion-weighted imaging (DWI) was performed to visualize the fiber tract at risk. DWI data were fused with those obtained from anatomic T1-weighted magnetic resonance imaging. A single-rack three-dimensional ultrasound neuronavigation system, which simultaneously displays the MRI scan and the corresponding ultrasound image, was used intraoperatively for 1) navigation; 2) definition of fixed and potentially shifting ultrasound landmarks near the fiber tract; and 3) sequential image updating at different steps of resection. The result was time-dependent brain deformation data. With a standard personal computer equipped with standard image software, the brain shift-associated fiber tract deformation was assessed by use of sequential landmark registration. After surgery, DWI was performed to confirm the predicted fiber tract deformation.

RESULTS:
The lesions were removed without morbidity. Comparison of three-dimensional ultrasound with DWI and T1-weighted magnetic resonance imaging data allowed us to define fixed and potentially shifting landmarks close to the respective fiber tract. Postoperative DWI confirmed that the actual fiber tract position at the conclusion of surgery corresponded to the sonographically predicted fiber tract position.

CONCLUSION:
By definition and sequential intraoperative registration of ultrasound landmarks near the fiber tract, brain shift-associated deformation of a tract that is not visible sonographically can be assessed correctly. This approach seems to help identify and avoid eloquent brain areas during intracranial surgery.
Waterjet Dissection versus Ultrasonic Aspiration in Epilepsy Surgery
Authors: Oertel Joachim , Gaab Michael Robert , Runge Uwe , Schroeder Henry Werner Siegfried , Piek Juergen 
Published: February 2005

AbstractOBJECTIVE:Waterjet dissection is currently under close investigation in neurosurgery. Experimentally, precise brain parenchyma dissection with vessel preservation has been demonstrated. Clinically, the safety of the instrument has already been proved. However, precise data demonstrating that waterjet dissection indeed reduces surgical blood loss are still missing.METHODS:The authors applied the waterjet device in a prospective randomized study in comparison with the ultrasonic aspirator. Because there is little variability in the procedure, 30 patients with temporal lobe epilepsy receiving a tailored temporal lobe resection between December 1999 and October 2002 were selected for this study. Intraoperative vessel preservation, intraoperative blood loss, surgical complications, and epilepsy outcome were evaluated. All patients were followed at 3-month intervals.RESULTS:During surgery, both instruments were easy to handle. Only with the waterjet dissector, however, were even small intraparenchymal blood vessels preserved. Intraoperative blood loss was significantly reduced with the waterjet (mean, 70 ± 46 ml) compared with the ultrasonic aspirator (mean, 121 ± 48 ml). However, no difference in the necessity for blood transfusion occurred. No difference was observed with respect to operation time (238.6 ± 37.0 min with the waterjet, 247.5 ± 41.5 min with the ultrasonic aspirator), surgical complications, and outcome.CONCLUSION:The waterjet dissector enables a significant reduction of intraoperative blood loss in the investigated setting. However, further studies are needed to confirm these results with a larger number of patients. Studies also are needed to prove that the reduction of blood loss is of clinical relevance for the outcome of the patients.
Orbitozygomatic Approach to Basilar Apex Aneurysms
Authors: Hsu Frank P.K. , Clatterbuck Richard E. , Spetzler Robert F. 
Published: February 2005

Abstract
BASILAR APEX REGION aneurysms are among the most complex cerebral aneurysms. They are not, however, among the most common aneurysms, and increased use of endovascular treatment has further decreased the number of patients with these lesions who undergo surgery. Nonetheless, not all basilar apex aneurysms are amenable to coil embolization, and neurosurgeons must be prepared to treat patients with basilar apex aneurysms surgically. We prefer an orbitozygomatic craniotomy and transsylvian approach. Meticulous exercise of the basic tenets of aneurysm surgery (proximal vascular control, sharp dissection, and preservation of perforating vessels) is crucial to optimal patient outcomes.
Superficial Temporal Artery-to-Middle Cerebral Artery Bypass
Authors: Charbel Fady T. , Meglio Guido , Amin-Hanjani Sepideh 
Published: February 2005

Abstract
THE SUPERFICIAL TEMPORAL artery-to-middle cerebral artery bypass represents the mainstay of bypass operations for cerebral revascularization. The role of this operation in the setting of cerebrovascular occlusive disease, with compromised cerebral hemodynamic reserve, is a topic of current investigation. In this report, we describe technical nuances to avert potential pitfalls in the performance of this procedure. The use of intraoperative quantitative blood flow measurements as a reliable method of assessing the success of the bypass is also described.
Ideal Suture Diameter is Critical for Consistent Middle Cerebral Artery Occlusion in Mice
Authors: Türeyen Kudret , Vemuganti Raghu , Sailor Kurt A. , Dempsey Robert J. 
Published: February 2005

Abstract

OBJECTIVE:
The use of transgenic and knockout mice has led to a need for a consistent model of mouse transient focal cerebral ischemia. In a great majority of the published mouse middle cerebral artery (MCA) occlusion studies, the methods indicated the type of intraluminal suture used without indicating the actual suture diameter after modification. We attempted to determine the ideal suture diameter to produce consistent occlusion in the MCA of adult male C57BL/6 mice.

METHODS:
Suture tips were coated to a depth 4 mm with glue, and 6-0 sutures of eight different, precisely measured diameters were produced. The coated 6-0 sutures in different diameters were introduced 10 mm into the internal carotid artery via the external carotid artery of the mice to produce MCA occlusion (n = 40; five animals for each diameter), and the mice (22–24 g) were transaortically perfused with saline. The base of the brain was exposed, and photographs of the vessels were obtained before and after transaortic injection of Evans blue dye to determine the consistency of MCA occlusion for each suture diameter. Cerebral blood flow was measured 10 minutes before occlusion and 20 minutes after reperfusion, and 2,3,5-triphenyltetrazolium chloride staining was performed to demonstrate the ischemic damage in additional animals with 110-μm (n = 5) and 180-μm (n = 8) diameter sutures.

RESULTS:
Sutures measuring 170 μm and 180 μm in diameter consistently occluded the MCA of C57BL/6 mice. In addition, 2,3,5-triphenyltetrazolium chloride staining demonstrated consistent infarction with180-μm diameter sutures. The infarct volume was 36.3 ± 4.2 mm3.

CONCLUSION:
Small changes in the diameter of the occlusion suture tip affect consistency in the mouse MCA occlusion model.
Awake Craniotomy for Microsurgical Obliteration of Mycotic Aneurysms: Technical Report of Three Cases
Authors: Lüders Jürgen C. , Steinmetz Michael P. , Mayberg Marc R. 
Published: February 2005

Abstract

OBJECTIVE AND IMPORTANCE:
Infectious (mycotic) aneurysms that do not resolve with medical treatment require surgical obliteration, usually requiring sacrifice of the parent artery. In addition, patients with mycotic aneurysms frequently need subsequent cardiac valve repair, which often necessitates anticoagulation. Three cases of awake craniotomy for microsurgical clipping of mycotic aneurysms are presented. Awake minimally invasive craniotomy using frameless stereotactic guidance on the basis of computed tomographic angiography enables temporary occlusion of the parent artery with neurological assessment before obliteration of the aneurysm.

CLINICAL PRESENTATION:
A 56-year-old woman presented with progressively worsening mitral valve disease and a history of subacute bacterial endocarditis and subarachnoid hemorrhage 30 years previously. A cerebral angiogram revealed a 4-mm left middle cerebral artery (MCA) angular branch aneurysm, which required obliteration before mitral valve replacement. The second patient, a 64-year-old woman with a history of rheumatic fever, had an 8-mm right distal MCA aneurysm diagnosed in the setting of pulmonary abscess and worsening cardiac function as a result of mitral valve disease. The third patient, a 57-year-old man with a history of fevers, night sweats, and progressive mitral valve disease, had an enlarging left MCA angular branch aneurysm despite the administration of antibiotics. Because of their location on distal MCA branches, none of the aneurysms were amenable to preoperative test balloon occlusion.

INTERVENTION:
After undergoing stereotactic computed tomographic angiography with fiducial markers, the patients underwent a minimally invasive awake craniotomy with frameless stereotactic navigation. In all cases, the results of the neurological examination were unchanged during temporary parent artery occlusion and the aneurysms were successfully obliterated.

CONCLUSION:
Awake minimally invasive craniotomy for an infectious aneurysm located in eloquent brain enables awake testing before permanent clipping or vessel sacrifice. Combining frameless stereotactic navigation with computed tomographic angiography allowed us to perform the operation quickly through a small craniotomy with minimal exploration.