bluuebunny/crossref_metadata_2025_split huggingface dataset:
Convective delivery of macromolecules into the naive and traumatized spinal cords of rats
Authors: Wood J. David , Lonser Russell R. , Gogate Nitin , Morrison Paul F. , Oldfield Edward H. 
Published: May 2009

Object. Many macromolecules have the potential to enhance recovery after injury and other lesions of the spinal cord, but because of the limited penetration of these compounds across the blood—spinal cord barrier, they cannot be used effectively. To determine if convective delivery could be used in a common animal model to investigate potential therapeutic macromolecules and to examine the effects of trauma on convective delivery in that model, the authors examined the distribution of a macromolecule in naive and traumatized rat spinal cords.
Methods. Using convection, various infusion volumes ([Vi]; 1, 2, and 4 µl) of 14C-albumin were infused into the dorsal columns of 13 naive and five traumatized rat spinal cords. Volume of distribution (Vd), homogeneity, percentage of recovery, and anatomical location were determined using quantitative autoradiography, scintillation analysis, calculation of kurtosis (K) value, and histological analysis. In the nontraumatized group, Vd was linearly proportional (R2 = 0.98) to Vi (Vd/Vi, 4.3 ± 0.6; mean ± standard deviation), with increases in Vd resulting from linear expansion (R2 = 0.94) primarily in the craniocaudal dimension. In the traumatized spinal cords, the Vd/Vi ratio (3.7 ± 0.5) was smaller (p < 0.02) and distributions were less confined to the craniocaudal dimension, with significantly larger cross-sectional distributions in the region of injury (p < 0.02) compared to the noninjured spinal cords. Histological analysis revealed that after infusion into the dorsal columns, albumin distribution in naive cords was limited to the dorsal white matter, but in the traumatized cords there was penetration into the central gray matter. The distribution of the infusate was homogeneous in the nontraumatized (K = −1.1) and traumatized (K = −1.1) spinal cords. Recovery of radioactivity was not significantly different (p > 0.05) between the nontraumatized (84.8 ± 6.8%) and traumatized (79.7 ± 12.1%) groups.
Conclusions. Direct convective delivery of infusate can be used to distribute macromolecules in a predictable, homogeneous manner over significant volumes of naive and traumatized rat spinal cord. These characteristics make it a valuable tool to investigate the therapeutic potential of various compounds for the treatment of injury and spinal cord disease.
Transarterial embolization of aneurysms associated with spinal cord arteriovenous malformations
Authors: Konan Alexis Victorien , Raymond Jean , Roy Daniel 
Published: May 2009

✓ The authors sought to show the feasibility and discuss the rationale of embolization of aneurysms associated with spinal cord arteriovenous malformations (SCAVMs). The authors reviewed the clinical presentation, magnetic resonance (MR) images, spinal angiograms, and clinical evolution of four patients treated for aneurysms associated with an SCAVM. Aneurysms were located on branches of the anterior spinal artery in three patients and on radiculopial arteries in two patients; one patient harbored two lesions. Treatment consisted of superselective bucrylate embolization of the branches harboring the aneurysms, with preservation of the arterial axis. Follow-up angiograms were obtained at 3 to 6 months postembolization in all patients.
All patients presented with hemorrhagic events. Hematomyelia was clearly related to a sulcocommissural or a vasa corona aneurysm in two patients. Another sulcocommissural aneurysm and multiple radiculopial aneurysms were presumed to be the cause of subarachnoid hemorrhage in two other patients. One patient harbored aneurysms on a sulcocommissural artery and on a radiculopial artery. All aneurysms were permanently obliterated. In one patient with a single fistula, the SCAVM was cured. The SCAVM was only partially obliterated (95, 50, and 20% in apparent volume) in three other patients. There were no complications or rebleeding episodes during a follow-up period of 17 to 37 months.
Aneurysms associated with SCAVMs can be eradicated by supraselective embolization, even on the anterior spinal artery territory. For patients presenting with hemorrhage and prohibitive risk of complete resection, embolization of aneurysms may decrease the risk of further rebleeding.
Risk factors for adjacent-segment failure following lumbar fixation with rigid instrumentation for degenerative instability
Authors: Etebar Shahin , Cahill David W. 
Published: May 2009

Object. The authors performed a retrospective analysis of 125 consecutive patients in whom instrumentation was placed to promote lumbar fusion for the treatment of degenerative instability. All procedures were performed by a single surgeon. The authors sought to determine the risk factors for next-segment degeneration after lumbar spinal fusion with rigid instrumentation.
Methods. Thirty-one of 125 fusion procedures were performed in women who were postmenopausal. A total of 18 of 125 patients developed symptomatic next-segment degeneration at a previously asymptomatic level; 15 were postmenopausal women. Data were obtained in patients with next-segment failure based on radiographic studies, neurological assessment, demographic factors, and sequential follow-up examinations. The mean follow-up period for this group was 44.8 months. All women were postmenopausal, and 53% received biphosphonate drugs and calcium supplementation preoperatively for osteopenia. Twenty percent of all patients with next-segment failure were cigarette smokers. Next-segment diseases included spondylolisthesis (39%), spinal canal stenosis due to disc herniation and/or facet hypertrophy (33%), stress fracture of the adjacent vertebral body (28%), and scoliosis (17%). Patients frequently had more than one degenerative process at the next segment.
Conclusions. The risk of adjacent-segment failure is clearly higher for patients in whom lumbar fusion with rigid instrumentation is performed to treat degenerative instability. This risk appears to be especially high in postmenopausal women.
Cervical laminectomy without fusion in patients with rheumatoid arthritis
Authors: Christensson Dan , Säveland Hans , Zygmunt Stefan , Jonsson Kjell , Rydholm Urban 
Published: May 2009

Object. The authors performed a prospective study to determine whether cervical laminectomy without simultaneous fusion results in spinal instability.
Methods. Because of clinical and radiographic signs of cord compression, 15 patients with rheumatoid arthritis (including one with Bechterew's disease) and severe involvement of the cervical spine underwent decompressive laminectomy without fusion performed on one or more levels. Preoperative flexion—extension radiographs demonstrated dislocation but no signs of instability at the level of cord compression.
Clinical and radiological reexamination were performed twice at a median of 15 months (6–24 months) and 43 months (28–72 months) postoperatively. One patient developed severe vertical translocation 28 months after undergoing a C-1 laminectomy, which led to sudden tetraplegia. She required reoperation in which posterior fusion was performed. No signs of additional instability at the operated levels were found in the remaining 14 patients. In three patients increased but stable dislocation was demonstrated. The results of clinical examination were favorable in most patients, with improvement of neurological symptoms and less pain.
Conclusions. The authors conclude that decompressive laminectomy in which the facet joints are preserved can be performed in the rheumatoid arthritis-affected cervical spine in selected patients in whom signs of cord compression are demonstrated, but in whom radiographic and preoperative signs of instability are not. Performing a simultaneous fusion procedure does not always appear necessary. Vertical translocation must be detected early, and if present, a C-1 laminectomy should be followed by occipitocervical fusion.
A prospective randomized double-blind controlled trial to evaluate the efficacy of an analgesic epidural paste following lumbar decompressive surgery
Authors: Hurlbert R. John , Theodore Nicholas , Drabier Janine B. , Magwood Andrea M. , Sonntag Volker K. H. 
Published: May 2009

Object. Pain control can often be improved by local (as opposed to systemic) application of analgesic and/or anesthetic medication. The purpose of this study was to evaluate the efficacy of a single-dose epidural analgesic “paste” in the control of postoperative pain in patients who have undergone lumbar decompressive surgery.
Methods. Sixty patients undergoing routine elective lumbar decompressive surgery were randomized in a double-blind fashion to one of two groups: those receiving active paste or placebo paste. The paste was applied to the exposed dura at the time of surgery, just prior to wound closure. Patients received follow-up care in the hospital and at home for 3 months postsurgery. Several outcome measures were studied to ascertain differences in pain control and to ensure comparability between groups. Patients who received active paste demonstrated significantly lower pain scores compared with those who received placebo paste for up to 6 weeks postoperatively. General health perception indexed by the Short Form 36 was also significantly better in patients who received active paste for up to 6 weeks. In-hospital and outpatient oral narcotic consumption was significantly lower in the active paste-treated group. Inpatient straight leg raising scores were improved in those patients who received active compared with control paste.
Conclusions. Application of an analgesic paste directly to the epidural space during lumbar decompressive surgery significantly improves postoperative pain control, reduces prescribed analgesic drug consumption, and improves overall health perception for up to 6 weeks following surgery. The authors conclude that this postoperative pain control strategy is both effective and safe and may provide a new standard of pain management in patients undergoing lumbar discectomy or laminectomy.
Variations of the extreme-lateral craniocervical approach: anatomical study and clinical analysis of 69 patients
Authors: Salas Eduardo , Sekhar Laligam N. , Ziyal Ibrahim M. , Caputy Anthony J. , Wright Donald C. 
Published: May 2009

Object. The aim of this study was to describe six variations of the extreme-lateral craniocervical approach, their application, and treatment results.
Methods. During a 4-year period 69 patients underwent surgery in which six variations of the extreme-lateral craniocervical approach were performed. The variations included: the transfacetal approach (TFA), performed to treat four lesions in the upper cervical spine anterior or anterolateral to the spinal cord; the retrocondylar approach, to treat five intradural lesions located anterolateral to the medulla oblongata and six vascular lesions to expose the extradural segment of the vertebral artery (VA); the partial transcondylar approach (PTCA), to treat 18 intradural lesions located anterior to the medulla oblongata; the complete transcondylar approach (CTCA), to treat 13 extradural lesions that involved the lower clivus and anterior upper cervical spine; the extreme-lateral transjugular approach, to treat 14 jugular foramen tumors; and the transtubercular approach with or without division of the sigmoid sinus, to treat complex VA and vertebrobasilar junction aneurysms. An anatomical prosection was performed to study the surgical exposure of each of the six variations of the extreme-lateral craniocervical approach.
Total removal was achieved in 35 (69%) of the patients with tumor; subtotal resection was achieved in 16 (31%) of those patients. In the 12 patients with VA aneurysms, seven underwent clipping, three underwent trapping and a vein graft bypass procedure, and two underwent trapping without the use of a bypass procedure. In five other patients, different cystic, inflammatory, and other vascular lesions were successfully treated. Fifty percent of the patients who underwent surgery via the TFA, 83% via the of the CTCA, and 11% via the PTCA required an occipitocervical fusion procedure. The mean Karnofsky Performance Scale score was 74.7 preoperatively and 76.4 postoperatively. Major complications were hydrocephalus (nine patients), cerebrospinal fluid leakage (seven patients), worsened cranial nerve function (seven patients), vertebrobasilar vasospasm (one patient), and sigmoid sinus thrombosis (one patient).
Conclusions. To treat lesions in the region of the foramen magnum and surrounding areas, the approach should be tailored to each specific lesion to provide the needed exposure without unnecessary operative steps.
Vascular endothelial growth/permeability factor in spinal cord injury
Authors: Vaquero Jesús , Zurita Mercedes , de Oya Santiago , Coca Santiago 
Published: May 2009

Object. Predicated on the hypothesis that this cytokine can contribute to the development of vascular hyperpermeability, leading to tissue edema after trauma, the purpose of this study was to determine the presence in tissue of vascular endothelial growth/permeability factor (VEG/PF) after experimental spinal cord injury.
Methods. The presence of VEG/PF was studied at 8 hours and 2, 8, and 14 days after a traumatic injury in adult Wistar rats. Studies were conducted in which a monoclonal antibody to the VEG/PF was used. Strong VEG/PF immunoreactivity was detected in the walls of pial and intramedullary vessels and in reactive astrocytes 8 hours posttrauma and was unchanged on Days 2 and 8. By Day 14, immunoreactivity decreased, and most of the arterioles from the pia and gray matter showed no mural VEG/PF.
Conclusions. The authors' present findings suggest a role for this cytokine in the development of tissue edema after spinal cord trauma and point to the possible usefulness of a therapeutic approach to spinal cord injury based on blocking the cell expression of VEG/PF or its physiological effects.
Use of porous hydroxyapatite graft containing recombinant human bone morphogenetic protein-2 for cervical fusion in a caprine model
Authors: Takahashi Toshiyuki , Tominaga Teiji , Watabe Noriaki , Yokobori A. Toshimitu , Sasada Hiroshi , Yoshimoto Takashi 
Published: May 2009

Object. The efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) for enhancing anterior cervical spine interbody fusion when added to a porous hydroxyapatite (HA) graft was investigated.
Methods. Fourteen mature goats underwent three-level anterior discectomies after induction of endotracheal anesthesia. Porous HA grafts that contained 0, 5, and 50 µg of rhBMP-2 were placed concurrently with anterior cervical spine plates to achieve interbody fusion. The fusion rate, radiological findings, biomechanical stiffness, and histological appearance were evaluated in 42 spinal units immediately and again at 4 and 12 weeks after graft and plate placement.
At 12 weeks postsurgery, manual testing showed a 100% fusion rate in the spines with HA grafts containing high-dose rhBMP-2; however, only a 50% fusion rate was shown in spines with grafts that contained no or low-dose rhBMP-2. On radiographic and histological studies the process of solid fusion was seen to be more advanced in relation to the use of larger amounts of rhBMP-2. Biomechanical testing demonstrated significantly higher stiffness values for grafts that contained high-dose rhBMP-2 than those without rhBMP-2 in flexion at 4 weeks, as well as in flexion, extension, and lateral bending tests at 12 weeks. Histological analysis demonstrated that rhBMP-2 increased the amount of bone apposition on the surface of the implants and promoted bone formation in the porous structure without increasing the penetration distance.
Conclusions. Through osteogenesis at the fusion site, the addition of rhBMP-2 to a porous HA ceramic graft enhances the rate of anterior cervical fusion.
A new type of microelectrode for obtaining unitary recordings in the human spinal cord
Authors: Guenot Marc , Hupe Jean-Michel , Mertens Patrick , Ainsworth Alan , Bullier Jean , Sindou Marc 
Published: May 2009

Object. In this paper the authors report on the conception and adjustment of a microelectrode used to obtain unitary recordings in the human spinal cord.
Methods. To overcome the difficulties related to intraoperative pulsations of the spinal cord, the authors opted to use a floating microelectrode. Because the recordings are obtained most often from spontaneous activities, it is difficult, with a single microelectrode, to separate spikes from electrical artifacts that are related to the switching of devices. Consequently, the authors designed a dual microelectrode made of two tungsten-in-glass—attached microelectrodes separated by 300 µm. Because the two electrodes cannot obtain recordings in the same neuron, it is possible to distinguish unambiguously spikes (recorded on one tip) from electrical artifacts (recorded simultaneously on the two tips). The dual microelectrode is 2 cm long, with a 20-µm tip length, and 800 to 1200—Ohms impedance. This microelectrode can be implanted “free hand,” in the dorsal horn, by using a microsurgical forceps under a surgical microscope. The data analysis is performed off-line with spike sorter hardware.
In the dorsal horns in 17 patients who were selected to undergo a dorsal root entry zone (DREZ) rhizotomy to treat various pathological conditions, unitary recordings were obtained using this double microelectrode. The authors recorded 57 neurons in good conditions of stability and isolation.
Conclusions. The microelectrode described in this paper was successfully used to obtain recordings in neurons in more than 85% of the patients. This simplified, floating double microelectrode can therefore be considered for use in microsurgical DREZ rhizotomy to obtain unitary recordings in the human spinal dorsal horn.
Artificial lamina-assisted laminoplasty performed in seven cases
Authors: Fornari Maurizio , Luccarelli Giovanni , Giombini Sergio , Chiapparini Luisa 
Published: May 2009

Object. The authors attempted to simplify the operative approach to severe multilevel cervical spondylotic myelopathy. Seven patients with progressive and severe myelopathy underwent modified double-door laminoplasty during a 5-month period.
Methods. The double-door laminoplasty procedure was modified by using two artificial titanium laminae obtained by simple surgical 0.5-mm Ti-mesh (rather than by bone graft or ceramic spacers).
Preoperatively, gait disturbance was present in all patients with long-tract signs on neurological examination. In all cases the sagittal diameter of the cervical spinal canal was somewhat reduced (< 10 mm) by congenital stenosis, and further severe compression of the spinal cord resulted from osteophytic bars and calcified ligamenta flava at different levels. No abnormal alignment, pathological movements, or instability was present. Computerized tomography (CT) studies demonstrated severe multilevel cervical compression, and T2-weighted magnetic resonance (MR) imaging demonstrated pathological areas of hyperintensity within the spinal cord in all cases.
In the initial follow-up study (range 8–12 months), the patients who underwent this procedure experienced marked improvement of gait disturbance without any significant incidence of morbidity or complications. Postoperative CT and MR imaging studies demonstrated complete spinal cord decompression and restoration of the patency of the subarachnoid spaces.
Conclusions. The proposed procedure has the advantage of achieving both an immediate stabilization of the open laminae by means of a bridgelike mechanism and protection from the possible compression of the dural sac by paravertebral muscles.
Significance of a persistent positive straight leg raising test after lumbar disc surgery
Authors: Jönsson Bo , Strömqvist Björn 
Published: May 2009

Object. Results of the straight leg raising (SLR) test provide the clinician with valuable information regarding possible causes of a patient's pain. In a previous study the results have also demonstrated a correlation between the outcome of the test and the severity of pain, as well as the prognostic value of the test; patients for whom the SLR test is persistently positive postoperatively appear to have a poorer short-term outcome. In a prospective study of 200 consecutive patients who underwent surgery for disc herniation, the authors evaluated the frequency of repeated surgery and outcome of surgery in patients with a persistent postoperative positive SLR test.
Methods. The preoperative radiological evaluation included myelography, computerized tomography scanning, and/or magnetic resonance imaging. Preoperatively as well as 4, 12, and 24 months postoperatively, each patient was interviewed and examined using a standard protocol in which common symptoms and signs were described. The result of the SLR test was also classified into one of four categories: positive 0 to 30°; positive 30 to 60°, positive greater than 60°, or negative, and the surgical results were evaluated using a four-grade scale.
Preoperatively, the SLR test was positive in 86% of patients. At 4 months postoperatively, 22% still had a positive SLR test. For the patients whose SLR test was positive 4 months postoperatively, the long-term outcome at all three follow-up examinations was inferior; this difference was statistically significant.
Conclusions. During the 2-year period, the reoperation rate was 18% (eight of 44) in patients with a positive postoperative SLR test compared with 4.5% (seven of 156) in patients whose postoperative SLR test was negative. A postoperative positive SLR test thus correlates to an unfavorable surgical outcome.