Calcium Microcrystal Formation in Recurrent Herniation Patients After Autologous Disc Cell Transplantation.

Autologous disc cell transplantation (ADCT) is a cell-based therapy aiming to initiate regeneration of intervertebral disc (IVD) tissue, but little is known about potential risks. This study aims to investigate the presence of structural phenomena accompanying the transformation process after ADCT treatment in IVD disease. Structural phenomena of ADCT-treated patients (Group 1, n = 10) with recurrent disc herniation were compared to conventionally-treated patients with recurrent herniation (Group 2, n = 10) and patients with a first-time herniation (Group 3, n = 10). For ethical reasons, a control group of ADCT patients who did not have a recurrent disc herniation was not possible. Tissue samples were obtained via micro-sequestrectomy after disc herniation and analyzed by micro-computed tomography, scanning electron microscopy, energy dispersive spectroscopy, and histology in terms of calcification zones, tissue structure, cell density, cell morphology, and elemental composition. The major differentiator between sample groups was calcium microcrystal formation in all ADCT samples, not found in any of the control group samples, which may indicate disc degradation. The incorporation of mineral particles provided clear contrast between the different materials and chemical analysis of a single particle indicated the presence of magnesium-containing calcium phosphate. As IVD calcification is a primary indicator of disc degeneration, further investigation of ADCT and detailed investigations assessing each patient's Pfirrmann degeneration grade following herniation is warranted. Structural phenomena unique to ADCT herniation prompt further investigation of the therapy's mechanisms and its effect on IVD tissue. However, the impossibility of a perfect control group limits the generalizable interpretation of the results.

Does sagittal position of the CTDR-related centre of rotation influence functional outcome? Prospective 2-year follow-up analysis.

PURPOSE: Recent studies describe significant rates of heterotopic ossification (HO) after cervical total disc replacement (CTDR). Little is known about the reasons, and one aspect that requires further in vivo investigation is the biomechanical alteration after CTDR and the role of the implant-related centre of rotation (CORi) in particular. The role of the sagittal position of the CORi on functional outcome in two versions of a semi-constrained disc prosthesis with sagittally different CORi is the topic of this study. METHODS: Patients were candidates for single-level CTDR between C3 and C7 who suffered from CDDD and received a standard or flat version of activ C™ (Aesculap AG, Tuttlingen). Clinical and radiographic assessments were determined preoperatively, intraoperatively, at discharge and again at 6 weeks, 6 months, 1 and 2 years. Radiographic examinations were performed independently using specialized quantitative motion analysis software. RESULTS: Clinical outcome improved significantly regarding NDI as well as VAS on neck and arm pain with no differences in mean improvement by study group. Segmental angle measures show a significantly better lordotic alignment for both groups after surgery, but the degree of correction achieved is higher in the flat group. Correlation analysis proves that the more anterior the CORi is positioned, the higher the lordotic correction is achieved (Pearson rho -0.385). Segmental ROM decreased in the standard group but was maintained for flat implants. At present, our data do not demonstrate a correlation between CORi and ROM at 2 years. Two years after surgery, severe HO grade III-IV was present in 31.6 % standard and 13.1 % flat cases with significant differences. Grouping according to HO severity showed comparable sagittal positions of CORi for flat implants but a more posterior position in the severe HO group for standard implants. CONCLUSIONS: Our results confirm the influence of CORi location on segmental alignment, kinematics and HO for a semi-constrained CTDR, but it also indicates a multifactorial process.

The impact of psychiatric comorbidity on quality of life in patients undergoing herniated disc surgery.

BACKGROUND: Recent studies examined the role of psychiatric comorbidity in the process of rehabilitation in patients undergoing herniated disc surgery. These patients suffer from physical and psychosocial complaints or symptoms, which impact their everyday life negatively and the success of rehabilitation potentially. The objectives of this study are (1) to examine the quality of life (QoL) in disc surgery patients and to compare the findings with reference data from the general German population, and (2) to investigate the impact of psychiatric comorbidity on QoL of patients undergoing herniated disc surgery. METHODS: This study consists of 305 patients aged between 18 and 55 years who took part in face-to-face interviews during their hospital stay. Psychiatric comorbidity was assessed with the Composite International Diagnostic Interview (CIDI-DIA-X). By means of the 36-Item Short-Form Health Survey (SF-36), QoL was assessed in patients undergoing herniated disc surgery with and without psychiatric comorbidity. These findings were compared with the QoL of a representative sample of the general German population. RESULTS: Compared with the general population, QoL in patients with herniated disc surgery was lower in all domains of the SF-36. Psychiatric comorbidity impacts the QoL in patients with herniated disc surgery in all SF-36 domains except "physical function". The patients with psychiatric comorbidity showed significantly lower levels of QoL in the domains "bodily pain", "vitality", "social function", "role emotional", and "mental health". CONCLUSIONS: Psychiatric comorbidity has a substantial adverse effect on QoL in patients undergoing disc surgery. Therefore, it will be necessary to diagnose psychiatric comorbidities at an early stage and to include psychosocial interventions in the treatment of herniated disc patients aimed at improving deficits in psychosocial functioning and QoL.

Cell transplantation in lumbar spine disc degeneration disease.

Low back pain is an extremely common symptom, affecting nearly three-quarters of the population sometime in their life. Given that disc herniation is thought to be an extension of progressive disc degeneration that attends the normal aging process, seeking an effective therapy that staves off disc degeneration has been considered a logical attempt to reduce back pain. The most apparent cellular and biochemical changes attributable to degeneration include a decrease in cell density in the disc that is accompanied by a reduction in synthesis of cartilage-specific extracellular matrix components. With this in mind, one therapeutic strategy would be to replace, regenerate, or augment the intervertebral disc cell population, with a goal of correcting matrix insufficiencies and restoring normal segment biomechanics. Biological restoration through the use of autologous disc chondrocyte transplantation offers a potential to achieve functional integration of disc metabolism and mechanics. We designed an animal study using the dog as our model to investigate this hypothesis by transplantation of autologous disc-derived chondrocytes into degenerated intervertebral discs. As a result we demonstrated that disc cells remained viable after transplantation; transplanted disc cells produced an extracellular matrix that contained components similar to normal intervertebral disc tissue; a statistically significant correlation between transplanting cells and retention of disc height could displayed. Following these results the Euro Disc Randomized Trial was initiated to embrace a representative patient group with persistent symptoms that had not responded to conservative treatment where an indication for surgical treatment was given. In the interim analyses we evaluated that patients who received autologous disc cell transplantation had greater pain reduction at 2 years compared with patients who did not receive cells following their discectomy surgery and discs in patients that received cells demonstrated a significant difference as a group in the fluid content of their treated disc when compared to control. Autologous disc-derived cell transplantation is technically feasible and biologically relevant to repairing disc damage and retarding disc degeneration. Adipose tissue provides an alternative source of regenerative cells with little donor site morbidity. These regenerative cells are able to differentiate into a nucleus pulposus-like phenotype when exposed to environmental factors similar to disc, and offer the inherent advantage of availability without the need for transporting, culturing, and expanding the cells. In an effort to develop a clinical option for cell placement and assess the response of the cells to the post-surgical milieu, adipose-derived cells were collected, concentrated, and transplanted under fluoroscopic guidance directly into a surgically damaged disc using our dog model. This study provides evidence that cells harvested from adipose tissue might offer a reliable source of regenerative potential capable of bio-restitution.

Total dura substitute in the spine: double layer dural substitute made from polylactide layer and bovine pericardium.

When there is significant loss of spinal dura mater, dural substitution with synthetic or allogenic materials is essential. In the case of laminectomy, mechanical protection and reformation of the dorsal spinal canal may be useful. This is a report on a patient with total dura loss through tumour atrophy of the dura and laminae. In order to reconstruct the dorsal face of the spinal canal a polylactide sheet was cut and shaped to fit the physiological contour. A bovine dura substitute was firmly attached and sutured to the inner surface of the polylactide shield. The implant was wedged in between the pedicles and the facet joints and resulted in a water-tight dura substitute maintaining the shape of the spinal canal and protecting it against mechanical forces and intradural scar formation.

Auto fluorescence of intervertebral disc tissue: a new diagnostic tool.

The paper reports on auto fluorescence phenomena of inter-vertebral human discs. It systematically investigates the auto fluorescence effects of ex vivo disc specimen and reports on surgical cases to demonstrate the potential value of the new method. The paper offers biologic explanations of the phenomenon and discusses the potential value of the UV auto fluorescence technique as a diagnostic tool. Intra- and postoperative observations are made by a surgical microscope with an integrated UV light source. Quantitative measurements were carried out using a photon counter and a spectrometer ex vivo. The auto fluorescence phenomenon allows the differentiation of traumatized and degenerated disc tissue intraoperatively in some cases, it allows the differentiation of bony and collagen endplate in cervical disc surgery. The source of the auto fluorescent light emission are amino acids of the collagen molecules. The proteoglycan components and the liquid components of the disc do not show relevant auto fluorescence. Emission wavelength of disc material is equivalent to color perception. It differs due to different collagen composition of the intervertebral disc components from yellow-green to blue-green and can be visualized in situ by naked eye.UV-auto fluorescence of inter-vertebral discs is a new clinical tool that has the potential to differentiate disc material from the anatomical surrounding, to distinguish between different fractions of the disc and to give information on the quality and status of the disc material. Since the technology has just emerged, it needs further investigations to quantify the clinical observations reported in this paper.

Cortical venous aneurysm isolated cerebral varix.

SUMMARY: Venous aneurysms so-called isolated cerebral varix, are known as a related pathology in arteriovenous malformations (AVM) due to the arterial pressure on venous drainage (16). They are also observed in combination with developmental venous anomalies (DVA) (2,4,8,15). However, isolated varix is a rare entity (1,7,11,13). They appear in most cases without neurological deficits. Some of the cases mimic a meningioma due to their manifestation in CT and MR imaging and their axial cortical localization. The case presented here is a isolated varix of a cortical vein located rostral to the motor strip. The patient was operated on successfully. The MRI and the histology of the case are presented.

Effect of partial targeted N-butyl-cyano-acrylate embolization in brain AVM.

BACKGROUND: The management of cerebral arteriovenous malformations needs effective treatments. So far, no study has shown that partial targeted embolization treatment (PTET) reduces the risk of intracranial hemorrhage with respect to the natural history of the malformation. METHODS: The pre-treatment and post-treatment-initialization hemorrhage incidences of neuro-interventional patients were compared. Two hundred fifteen patient years from 519 patients were used to observe the short term course of the untreated disease. Five hundred patient years from 326 patients were used to observe hemorrhage after the start of treatment. The Kaplan-Meier estimator of hemorrhage free time under treatment was compared with results in the literature. Confounding influences resulting from selection processes or the disease parameters were studied. RESULTS: The yearly hemorrhage incidence rate of all untreated patients was observed as 0.089 (95% CI [0.053, 0.138]). This rate was 0.052 (95% CI [0.019, 0.114]) in the subgroup of patients who underwent PTET later. In the same group the observed annual rate after the start of PTET was 0.036 (95% CI [0.021, 0.057]). Crawford's results about intracranial hemorrhage during the natural course show the lowest risk values compared to other published studies [3]. There was a significant difference between the Crawford's reference data and the ICH incidence after the start of PTET in the neuro-interventional population (p=0.037). The morbidity risk in treated patients was 5.3% for a transitory and 2% for a persisting neurological deficit. Mortality results were compared with those of Crawford. CONCLUSION: The neuro-interventional patients under study show a lower hemorrhage risk than the population studied by Crawford. A significant superiority with respect to hemorrhage risk is established two years after the start of the PTET treatment.

Cerebral arteriovenous malformations and associated aneurysms: analysis of 305 cases from a series of 662 patients.

OBJECTIVE: Spontaneous intracranial hemorrhage is the primary danger for patients with cerebral arteriovenous malformations (AVMs). Associated aneurysms are considered weak points that increase the risk of intracranial hemorrhage. Aneurysms are classified as proximal aneurysms (PROXs) or intranidal aneurysms (INs). METHODS: The present study was based on a series of 662 patients who presented with AVMs between 1985 and 1995. Its purpose was to evaluate prestated hypotheses using prospectively collected data. In 305 of these 662 patients, 372 INs and 313 PROXs were observed and analyzed with respect to their shapes, locations, and sizes. Partial targeted endovascular treatment with n-butylcyanoacrylate was performed for 450 of the 662 patients (68%) in this series, using a standard protocol. Of 450 treated patients, 181 (40%) had at least one IN and 138 (30.7%) had at least one PROX. Analysis of changes in the sizes of PROXs was based on the follow-up data for 83 treated patients, with a total of 149 PROXs. Changes in the sizes of PROXs in treated patients were analyzed with respect to PROX shapes, PROX locations, and treated AVM occlusion rates. Univariate and multivariate event data analyses were used to study factors influencing aneurysm shrinkage. False aneurysms were excluded from the series. RESULTS: Presentation with intracranial hemorrhage was not correlated with any type of aneurysm. However, INs demonstrated a higher rebleeding rate (P < 0.002) before treatment. Among 181 patients, 92.2% of INs were occluded, together with the related portions of the AVM nidi. In cases of PROXs, embolization of the cerebral AVM compartment fed by the artery with the aneurysm was a priority. During follow-up monitoring of 83 treated patients with 149 PROXs, 100% shrinkage was observed for 12 PROXs and more than 50% shrinkage was observed for 33 PROXs. The median time required for more than 50% shrinkage was 3.5 years. The shrinkage of PROXs was influenced by the degree of AVM occlusion (P = 0.027) and occurred faster for PROXs on midline structures, such as the anterior cerebral artery and the circle of Willis, compared with arteries distal to the circle of Willis (P = 0.004). No rupture of untreated PROXs was observed after partial targeted treatment of AVMs. CONCLUSION: PROXs are not primary treatment targets, compared with AVMs themselves. INs should be primary targets of endovascular therapy, because of their increased risk of rebleeding.

Multiple arteriovenous malformations of the spinal cord in an adolescent: case report.

We report long-term follow-up of a rare multiple arteriovenous malformation of the spinal cord in a 15-year-old patient. A significant reduction in the size of the lesion was achieved by microsurgical resection of the dorsal and lateral portions. This eliminated the initial source of subarachnoid haemorrhage, and the patient's condition remained stable for 10 years. Renewed angiography of the residual ventrolateral malformation became necessary after recurrent subarachnoid haemorrhage, and the centre of the malformation was embolised selectively with bucrylate. Following embolisation, prophylactic treatment with steroids and heparin led to rapid improvement of the pre-embolisation symptoms. Our observations indicate that venous flow in the spinal cord is highly sensitive to haemodynamic changes. The angioarchitecture was indicative of multifocal arteriovenous shunts, an extremely rare condition, and the question arises whether these shunts were acquired or congenital.

Paraplegia due to rupture of an anterior communicating artery aneurysm. Consequence of a rare anatomic variant of the A2 segment.

SUMMARY: A 44-year-old patient developed paraplegia following rupture of an anterior communicating artery aneurysm. There was no evidence of any spinal lesion. Cerebral angiography showed a paired bihemispheric disposition of the A2 segment. We report this case and consider the anatomical variants of the A2 segment described in literature. The paired bihemispheric variant was reported in 21% of the cases. An azygos (unpaired) artery was observed in 5% and a triplicated A2 segment in 20% of the cases.

Modern management of spinal and spinal cord vascular lesions.

Spinal arteriovenous shunts affect all age groups from neonates to the elderly in connection with different entities. The authors present 7 illustrative cases of spinal and spinal cord vascular lesions with different etiology, angioarchitecture, symptoms, risks, and prognosis, but similar pathophysiology: spinal cord AVM, multifocal AVM with venous impairment, paraspinal arteriovenous fistulas in children, spinal dural AV fistula, and an arteriovenous malformation of the filum terminale. Therapy was consistent and demonstrated the benefit of combined treatment. Specific endovascular embolisation with a permanent liquid substance (NBCA) is the method of choice. In 5 of the 7 patients, the malformation was completely occluded in one therapeutic session. Two patients needed additional embolisation. Systemic or neurological symptoms improved or regressed completely in all cases. No patient has had more than 3 sessions of endovascular approach. The filum terminale AVM was treated by direct surgery due to the risks of endovascular approach. As shown by our observations, venous flow in the intrinsic network of the spinal cord is highly sensitive to hemodynamic changes. Thus, the hemodynamic balance must be maintained to obtain stable embolisation results, particularly if a considerable size reduction of the AV shunt has been achieved.

[Use of GDC coils in treatment of inoperable aneurysms: report of initial experiences]. / Der Einsatz von GDC coils zur Behandlung inoperabler Aneurysmen: Erster Erfahrungsbericht.

The authors report on the endovascular occlusion of intracranial aneurysms with GDC coils in 8 patients. In 2 cases, the diagnosis was made because of subarachnoidal hemorrhage. Three patients complained about headache, and one patient had an oculomotor palsy. The findings were incidental in 2 cases. Angiography demonstrated an aneurysm of the internal carotid artery in 4 of the 6 females and in the 2 males (mean age 50 years) and a basilar artery aneurysm in 4 cases. The indication for endovascular treatment was established after carefully weighing the risks against those of a neurosurgical intervention. It was possible to occlude completely the aneurysm by induced electrothrombosis and to preserve the patency of the main vessel in all cases. One female (case 6) developed a hemiparesis due to embolism of a medial branch six hours after treatment. This receded completely after thrombolysis with urokinase. A second patient showed further growth of the internal carotid aneurysm on the control angiogram obtained after six months. Our initial results are encouraging. With increasing experience, endovascular treatment is expected to become the method of choice for the treatment of most inoperable cerebral aneurysms.

Paraspinal arteriovenous shunts in children.

Arteriovenous shunts within the spinal canal and in the paraspinal region are unusual. Spinal cord and dural arteriovenous communications have been the subject of numerous reports but paraspinal shunts causing venous congestion in the spinal canal are rarer and may present special problems in diagnosis and management. We describe three children with paraspinal arteriovenous malformations, associated with overt or potential venous congestion in the spinal canal. In each case, the lesion was successfully obliterated by endovascular therapy. Embolisation with permanent occlusive agents is an effective treatment for these rare but potentially debilitating lesions.

[Intramedullary neurinoma. Case report]. / Das intramedulläre Neurinom. Fallbericht.

The case of a 36-year-old patient with an intramedullary neurinoma of the thoracic spine without Recklinghausen's disease is presented. The intramedullary neurinoma is a very rare condition. Only 33 cases have been reported in the literature. To our knowledge, the case presented here is the first in German literature. The treatment of choice is tumor removal. The case described here was diagnosed by magnetic resonance imaging (MRI). Histologically, the tumor showed all features characteristic of a neurinoma. Postoperatively, the patient is nearly without complaints.