[Formation of desmoids in postoperative lumbar scars--a case report]. / Desmoidbildung in postoperativer lumbaler Narbe -- kasuistischer Beitrag.

Desmoids are tumours of the connective tissue cells with aggressive growth. Frequent recurrences of these tumours have often been described. Genetic and endocrine factors as well as local tissue biomechanics are thought to be responsible for the pathogenesis. This case report should contribute to the discussion about possible pathogenetic factors.

Laser-induced thermotherapy of neoplastic lesions in the brain--underlying tissue alterations, MRI-monitoring and clinical applicability.

Laser-induced thermotherapy (LITT) is a minimally invasive neurosurgical approach to the stereotactic treatment of brain tumors in poorly accessible regions. Its clinical applicability has been shown in several experimental and clinical studies under on-line monitoring by magnetic resonance imaging (MRI). This review characterizes LITT as an alternative neurosurgical approach with specific focus on the typical histological alterations and ultrastructural cellular changes following laser irradiation in the central nervous system. The spatial and temporal pattern of these changes is discussed in their relevance to the neurosurgical treatment of neoplastic lesions using LITT.

Prognostic significance of SSEP, BAEP and serum S-100B monitoring after aneurysm surgery.

OBJECTIVE: Changes in evoked potentials (EPs) and increased levels of S-100B protein were used to identify cerebral ischemia or glial damage and to predict neurological outcome in aneurysm patients. MATERIAL AND METHODS: Somatosensory evoked potentials and Brainstem auditory-evoked potentials, and serum S-100B protein were simultaneously investigated pre- and postoperatively over a period of 10 days in 43 patients with 47 aneurysms (six in the posterior fossa). RESULTS: The EP scores showed a strong correlation with the clinical outcome. Sensitivity was 73%, and specificity 81%. Pathological S-100B levels >0.5 mg/l were equal in predictive values (correct positive eight, false positive six, correct negative 26, false negative three). Initially increased S-100B levels, long-lasting S-100B elevation, and secondary increasing S-100B values correlated with an unfavorable outcome. High peak S-100B values correlated with bad EP scores at discharge. EP deterioration was the first indicator anticipating S-100B elevation and clinical deterioration in five patients. There was a good correlation between pathological S-100B values or EP findings and infarction on CT scan. CONCLUSIONS: Both EPs and S-100B protein showed a comparable high predictive value for outcome. S-100B reflects the extent of primary brain damage after subarachnoid hemorrhage and time course of ongoing secondary brain damage. Evoked potentials assess the functional integrity and tended to react earlier than S-100B protein before definitive structural damage occurred.

Coagulopathy and outcome in patients with chronic subdural haematoma.

OBJECTIVE: The coincidence of coagulatopathy and chronic subdural haematoma (CSH) requires correction of coagulation to facilitate surgery. We investigated the correlation between coagulopathy and outcome in CSH patients. MATERIAL AND METHODS: We analysed past medical history, surgical treatment and coagulation parameters of 114 patients. RESULTS: Coagulation disorders were found in 42%. Preoperative treatment with prothrombin complex concentrate was necessary in 14%. A significant difference (P < 0.05) of the preoperative level of platelets was found between recurrent CSH and non-recurrent group. Totally, we had to perform re-operations in 17.5%. Eighty-one patients presented with Glasgow coma scale (GCS) > or = 13. After surgery GCS was > or = 13 in n = 92. There was an improvement of GCS in 46 cases, 61 patients maintained GCS score levels. Outcome was significantly worse in the alcoholic group (P < 0.001), and in the recurrent group (P < 0.05). In patients with substitution of coagulation factors, outcome was worse in the group with post-operative substitution only (P < 0.05). CONCLUSION: In CSH, the coagulation parameters and a subtle correction of coagulation are of special interest, regarding the worse outcome in patients with recurrent CSH and in those requiring post-operative substitution.

[Comparative studies of patient positioning for lumbar intervertebral disk operation]. / Vergleichende Untersuchungen zur Lagerung bei lumbalen Bandscheibenoperationen.

For surgery on lumbar disks by the posterior route, patients are placed either on a Wilson frame or in genupectoral position. The aim of the prospective study was to record and describe the haemodynamic changes resulting from the patients' position. After written informed consent had been received, 80 neurosurgical patients undergoing lumbar disk surgery were randomly divided into two groups; group I--Wilson frame, group II--genupectoral position. In each group, 20 patients received total intravenous anaesthesia (Alfentanil or Remifentanil, Propofol) and 20 balanced anaesthesia with Isoflurane and Alfentanil or Remifentanil. Haemodynamic parameters (mean arterial pressure--MAP and heart rate--HR) were recorded automatically at three measuring times (MT): firstly, after induction of anaesthesia; secondly, before re-direction; thirdly, after re-direction on the Wilson frame or in the genupectoral position. Induction of anaesthesia did not lead to a significant decrease in MAP (MT 1: 92.5 +/- 15.2 mmHg, MT 2: 89 +/- 13.4 mmHg, n = 80). In group I (n = 40), no significant changes were observed in MAP and HR at MT 3 (p = 0.882, p = 0.051). In comparison to group I, the genupectoral position was associated with significant drops in MAP and HR. The genupectoral position caused a significant decrease in MAP (p < 0.001) and HR (p = 0.016) at MT 3. Our data suggest that body weight or body mass index do not necessarily lead to a preference for one of the two possible positions of the patient. Complications resulting from haemodynamic changes were not seen in either group. We recommend the Wilson frame for neurosurgical lumbar disk surgery in cases of cardiovascular or cerebrovascular disorders. The adaptive capacities in the genupectoral position as a result of the modifying distribution of blood volume are limited in these patients. Furthermore, the dose-dependent effects of different anaesthetics on haemodynamic parameters in these prone positions should be explored.

Microendoscopic lumbar discectomy versus open surgery: an intraoperative EMG study.

This study investigated electromyographic (EMG) activity as a marker of nerve root irritation during two different surgical procedures for lumbar disc herniation. Mechanically elicited EMG activity was recorded during the dynamic stages of surgery in muscle groups innervated by lumbar nerve roots. Confirmation of surgical activity was correlated with the activity of the electromyogram. Fifteen patients with lumbar disc herniations were treated via an endoscopic medial approach, and 15 patients via the open microscopic surgical technique. Results indicated that the endoscopic technique was superior to the open surgical technique and produced less irritation of the nerve root. Significantly less mechanically elicited activity was recorded during both the approach and the root mobilization. The study showed that microendoscopic discectomy allows a smaller incision and less tissue trauma with comparable visualization of the nerve structures than does open surgery.

Functional MRI of the spine: different patterns of positions of the forward flexed lumbar spine in healthy subjects.

Since the introduction of the technique of vertical open-configuration systems, efforts have been made to obtain functional lumbar spinal magnetic resonance (MR) images. The purpose of this study was to determine the relation between facet joint orientation and flexion patterns in the lower lumbar spine. Thirty-four normal subjects (18 women, 16 men) were examined in a vertical open 0.5-T MR scanner with T1-weighted gradient echo (GE) sequences. Flexion angles were digitally measured in the sagittal plane and facet joint orientation in the axial plane. The population showed three different functional flexion patterns: 17.6% (n=6) had kyphotic angles in all three lower lumbar levels during forward flexion (type 1), 50% (n= 17) had a lordotic angle at L5/S1 but kyphotic angles at L4/L5 and L3/L4 (type 2), and 32.4% (n=11) showed lordotic angles at L5/S1 and L4/L5 but a kyphotic angle at L3/L4 (type 3). There were statistically significant differences between flexion patterns and mean facet joint orientation: at 4/15 33.3 degrees for type 1, 33.5 degrees for type 2 and 46.2 degrees for type 3; at L5/S1 27.2 degrees for type 1, 46.4 degrees for type 2 and 48.1 degrees for type 3. There were no significant differences between the three groups at L3/L4. The three different flexion patterns in normal subjects and their relation to facet joint orientation have not been described previously. Knowledge of these patterns may lead to a better understanding of physiological spinal movement as a base for future investigations in low back pain patients.

Dynamic examination of the lumbar spine by using vertical, open magnetic resonance imaging.

OBJECT: The aim of this study was to determine the relationship of different structures of the lower lumbar spine during interventional movement examination. METHODS: Clinically healthy volunteers and patients suffering from degenerative disorders of the lumbar spine underwent vertical, open magnetic resonance (MR) imaging (0.5 tesla). Three functional patterns of lumbar spine motion were identified in 50 healthy volunteers (average age 25 years). The authors identified characteristic angles of the facet joints, as measured in the frontal plane. In 50 patients with degenerative disorders of the lumbar spine (41 with disc herniation, five with osteogenic spinal stenosis, and four with degenerative spondylolisthesis) the range of rotation was increased in the relevant spinal segments. Signs of neural compression were increased under motion. CONCLUSIONS: Dynamic examination in which vertical, open MR imaging is used demonstrated that the extent of neural compression as well as the increasing range of rotation are important signs of segmental instability.

[Brain tumor resections in an open 0.5-T MRT. 2 years' experiences from the neuroradiological viewpoint]. / Hirntumorresektionen in einem offenen 0,5 T-MRT. Zweijährige Erfahrungen aus neuroradiologischer Sicht.

After two years clinical experience using an open 0.5 T-MRI, which make it possible to control all steps of a brain tumor resection, the high expense in relation to the effect is proofed. In 80 MRI-guided brain tumor resections the indication, the degree of resection, the appearance of operative induced changes, complications and clinical state are analysed. The advantage of the method consists in safety of localisation and detection especially of intra-axial cerebral tumors, recording of intraoperative invisible tumor parts and saving eloquent areas during tumor resection. To have optimal results, all over the operation time, the participation of a special experienced radiologist is necessary. The best results are shown in treatment of low grade gliomas and tumors near eloquent areas.

Spinal markers: A new method for increasing accuracy in spinal navigation.

Spinal navigation opens up a completely new dimension in the planning and realization of neurosurgical and orthopedic procedures, and offers the possibility of simulating the operation preoperatively. There is currently only limited experience with spinal navigation, and despite the development of advanced software, intraoperative difficulties include identification of characteristic and reproducible anatomical landmarks, localization of these points in the surgical field, referencing, and intraoperative control. We report the use of a new kind of implantable fiducial marker in a case of a 58-year-old female patient with spondylolisthesis. Percutaneously applied spinal markers were used as prominent anatomical landmarks and permitted much easier intraoperative handling. In our opinion, in the hands of an experienced neurosurgeon or orthopedist, the additional preoperative time required for placement of such spinal markers is negligible.

Open MRI-guided neurosurgery.

OBJECTIVES: A number of different image-guided surgical techniques have been developed during the past decade. None of these methods can provide the surgeon with information about the dynamic changes that occur intra-operatively. MATERIAL AND METHOD: The first vertical open 0.5T MRI-scanner for intra-operative MRI-guided neurosurgery in Germany was installed at the University of Leipzig during the summer 1996. Since autumn 1996 a number of surgical procedures including biopsies (n = 31), craniotomies (n = 32), transsphenoidal procedures (n = 8) and interstitial lasertherapies (n = 3) have been performed using intra-operative MR image guidance. RESULTS: The development of MR-compatible and MR-safe non-magnetic instruments and components had to be solved. Specific surgical instruments were developed to perform biopsies, craniotomies, microsurgical tumour resections and transsphenoidal procedures in the 0.5-T open MRI. Several components required adaptation including the head holder the stereotactic navigation device, the high speed drill, the suction unit, the ultrasonic aspirator, the bipolar coagulation, the laser probe and the surgical microscope. All these newly developed technical features enable the neurosurgeon to perform a large number of surgical procedures under direct control and guidance of intra-operative MR imaging. In contrast to frame-based for framless navigation systems, intra-operative MRI provides accurate and immediate information during the progress of surgery. These intra-operative images allow definitive localization and targeting of the lesions and accommodate anatomical changes that may occur during surgery. CONCLUSION: Intra-operative MRI is helpful for navigation as well as determining of tumour margins to achieve a complete and safe resection of intracranial lesions. Complications related to the surgical procedure are reduced and the risk of neurological deterioration due to tumour removal and postoperative complications is minimized. It can be concluded that the intra-operative application of interventional MRI technology may represent a major step forward in the field of neurosurgery.

[Severe pulmonary complications following venous air embolism in neurosurgical operations in sitting position--2 case reports]. / Schwere pulmonale Störungen nach venöser Luftembolie bei neurochirurgischen Operationen in sitzender Position--zwei Fallberichte.

The occurrence of air embolism during neurosurgical operations in sitting position is described in two cases. Besides the Doppler ultrasound evidence, relevant effects on the cardiopulmonary situation during surgery were observed, which in one case forced an early end of the operation. Postoperative management in both cases was complicated by a pulmonary oedema. In severe intraoperative cardiopulmonary complications in connection with venous air embolism, the existence of pulmonary oedema should be assumed. Confirmation of the diagnosis and the correct therapy depend upon frequent postoperative chest X-rays.

[A new set for percutaneous implantation of the cardiac catheter in ventriculo-atrial shunt systems. A new technical note]. / Ein neues Set zur perkutanen Plazierung des kardialen Katheters ventrikuloatrialer Shuntsysteme. Eine technische Notiz.

The percutaneous insertion of the atrial catheter for ventriculoatrial shunts reveals as a sufficient alternative method for the open surgical preparation of neck veins. The authors use a special set based on the Seldinger-Technique. The direct punction procedure of the internal jugular vein is a wellknown method in anaesthesia and intensive-care-medicine. First experiences show as well as a shorter operation times and better cosmetic results in the neck region.

[Innervation anomalies--mechanism of adaptation or embryonal malformation?]. / Innervationsanomalien--Anpassungsmechanismus oder embryonale Fehlentwicklung?

After injuries innervationanomalies are observest. Are these anomalies mechanismen of adaption or an embryological malformation, is a still mansverst question. This paper tries some contributions to the answer. The use of modern muscleenzymhistochemistry in connection of histological findings of nerves in certain levels gives assertions on anomalies of innervation and mechanisms of reinnervation. After 14, 28, 56 and 112 days tissues of nerves and muscle from 66 female WISTAR-rats were investigated after various lesions. We have found in 15 not operated rats that the so called typegrouping can be a expression of reparation process after microlesions of nerve and muscle. We interpreted the anomalies as an expression of a reaction of adaption. The innervationanomalies succeeded in the fore and behind extremities of the rate indirectly. Above all embryological malformations can explain some anomalies of innervation on the fore extremities. We conclude from our results that communication among nerves and nerve bundles were developed or activated. These mechanism seems to be effective only about a short distance. We did not find a MARTIN-GRUBER-anostomosis. The findings of reinnervation of the musculature were attributed to cross-innervation, collateral and orthotope reinnervation. Generally the innervationanomalies are an expression of plasticity of the peripheral nervous system in all periods of life. In the first place we interpreted this phenomenous as adaption of nerves after injury and in the second place as embryological malformation.

[Nerve fiber regeneration in preformed tissue spaces]. / Nervenfaserregeneration in präformierten Gewebsräumen.

Described in this paper is a new artificial chamber model to enable in vivo investigation of nerve fiber regeneration. Transection of the sciatic nerve of a rat was followed by analysis of axonal regeneration and revascularisation in the tissue chamber. Vascularisation of the endoneurium via the newly formed epineurium and perineurium was almost physiological in the cavity formed. The latter was found to be suitable for application of drugs and neurotrophic substances.

[Assessing the myelogram of the narrow spinal canal]. / Zur Beurteilung der Myelogramme beim engen lumbalen Spinalkanal.

The myelograms of 40 patients who had been operated on because of stenosis of the lumbar vertebral canal, were retrospectively assessed and measured. As was to be expected, the diameters were reduced, especially the sagittal diameter. Three configurations of the epidural space were seen representing different spatial capacities. The type occurring particularly often in lumbar osteogenic stenosis, which is conditioned by the patient's constitution, must be considered as a predisposing factor for the manifestation of a lumbar compression syndrome on account of its small capacity.

[Primary melanoblastoma as a cause of occlusive hydrocephalus]. / Primäres Melanoblastom als Ursache eines Okklusivhydrocephalus.

Primary melanoblastomas of the Central Nervous System are comparatively rare tumors. Lumpy or diffuse forms may occur either alone or in combination. On the basis of actual case histories, diffuse cerebral and medullary melanoblastoma is presented as a rare cause of occlusive hydrocephalus.

[Innervation anomalies]. / Innervationsanomalien.

The deviation from anatomically described innervation can often occur. It is mainly described on muscles of the limbs. Constant attention should give to this fact during the process of diagnosis of peripheral nerve lesions. Electrophysiological methods (EMG, ENG with blockade of nerve, collision technique and simultaneous lead) can help to detect this anomalies. Double innervation, abnormal innervation and communications among nerves are causes of anomalies of innervation. The fact of communications of fibers among nerves is better called "nerve communication" than "nerve anastomosis". It is vague whether this anomalies of innervation are embryological malformations or reactions of adaptation after different diseases.

[The morphology of the lumbar spinal canal]. / Zur Morphologie des lumbalen Spinalkanals.

Measurements of cast preparations of epidural cavities yielded data characterising the "internal silhouette" of the lumbar vertebral canal. Three groups of different shapes of lumbar vertebral canal were found to be statistically distinguishable from each other. These are determined by the constitution of the patient. The different spatial capacity of the three types and the different relations of the diameters modify the value of the isolated determined distance, for example of the sagittal diameter at L5, which is a clinically extremely relevant factor that must be taken into account.

[Injuries of the basilar artery]. / Verletzungen der Arteria basilaris.

In 2 to 3 per cent of the severe craniocerebral occlusions of the cerebral basic arteries are observed. Traumatic vertebralis and basilaris thromboses are very rare. In view of the modern procedure in diagnostics and therapy the prognosis of these life-threatening traumatic consequences are not infaust. According to a casuistic information pathophysiology, diagnostic procedure and therapeutical possibilities, microsurgical or by local fibrinolysis, are discussed.