[Show abstract][Hide abstract] ABSTRACT: Critical incident monitoring is an important tool for quality improvement and the maintenance of high safety standards. It was developed for aviation safety and is now widely accepted as a useful tool to reduce medical care-related morbidity and mortality. Despite this widespread acceptance, the literature has no reports on any neurosurgical applications of critical incident monitoring. We describe the introduction of a mono-institutional critical incident reporting system in a neurosurgical department. Furthermore, we have developed a formula to assess possible counterstrategies.
All staff members of a neurosurgical department were advised to report critical incidents. The anonymous reporting form contained a box for the description of the incident, several multiple-choice questions on specific risk factors, place and reason for occurrence of the incident, severity of the consequences and suggested counterstrategies. The incident data was entered into an online documentation system (ADKA DokuPik) and evaluated by an external specialist. For data analysis we applied a modified assessment scheme initially designed for flight safety.
Data collection was started in September 2008. The average number of reported incidents was 18 per month (currently 216 in total). Most incidents occurred on the neurosurgical ward (64%). Human error was involved in 86% of the reported incidents. The largest group of incidents consisted of medication-related problems. Accordingly, counterstrategies were developed, resulting in a decrease in the relative number of reported medication-related incidents from 42% (March 09) to 30% (September 09).
Implementation of the critical incident reporting system presented no technical problems. The reporting rate was high compared to that reported in the current literature. The formulation, evaluation and introduction of specific counterstrategies to guard against selected groups of incidents may improve patient safety in neurosurgical departments.
Central European neurosurgery 12/2009; 72(1):15-21. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Autoimmune hypophysitis (AH) mimics the more common nonsecreting pituitary adenomas and can be diagnosed with certainty only histologically. Approximately 40% of patients with AH are still misdiagnosed as having pituitary macroadenoma and undergo unnecessary surgery. MR imaging is currently the best noninvasive diagnostic tool to differentiate AH from nonsecreting adenomas, though no single radiologic sign is diagnostically accurate. The purpose of this study was to develop a scoring system that summarizes numerous MR imaging signs to increase the probability of diagnosing AH before surgery.
This was a case-control study of 402 patients, which compared the presurgical pituitary MR imaging features of patients with nonsecreting pituitary adenoma and controls with AH. MR images were compared on the basis of 16 morphologic features besides sex, age, and relation to pregnancy.
Only 2 of the 19 proposed features tested lacked prognostic value. When the other 17 predictors were analyzed jointly in a multiple logistic regression model, 8 (relation to pregnancy, pituitary mass volume and symmetry, signal intensity and signal intensity homogeneity after gadolinium administration, posterior pituitary bright spot presence, stalk size, and mucosal swelling) remained significant predictors of a correct classification. The diagnostic score had a global performance of 0.9917 and correctly classified 97% of the patients, with a sensitivity of 92%, a specificity of 99%, a positive predictive value of 97%, and a negative predictive value of 97% for the diagnosis of AH.
This new radiologic score could be integrated into the management of patients with AH, who derive greater benefit from medical as opposed to surgical treatment.
American Journal of Neuroradiology 08/2009; 30(9):1766-72. · 3.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The combination of paranasal sinus osteoma, mucocele and brain abscess is rare. Only one other case has been reported so far, where the cerebral abscess was diagnosed intraoperatively. We report here on a second patient with combined frontal sinus osteoma, intracerebral mucocele as well as cerebral abscess. However, in our case, the diagnosis of cerebral abscess was reached prior to surgery, which allowed for a tailored treatment strategy with abscess puncture under neuronavigational guidance and, after 3 weeks of antibiotic therapy with documented abscess shrinkage, osteoma and mucocele resection as well as reconstruction of the eroded dura.
Central European neurosurgery 06/2009; 70(2):95-7. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We report two cases of coil migration after endovascular treatment of pseudoaneurysm of the internal carotid artery within the sphenoid sinus with coils and noncovered stents.
Two patients underwent sphenoid sinus exposure for pituitary adenoma and chronic infection, respectively. As a complication pseudoaneurysms of the internal carotid artery within the sphenoid sinus developed. One patient was treated with stent and coils, the second with coils alone. Both patients experienced coil migration after 9 and 26 months, respectively, with the necessity for further treatment. Imaging was performed using flat detector computed tomography (FD-CT). Literature review revealed two additional cases of coil migration and four patients with the same treatment in stable condition.
Pseudoaneurysms of the internal carotid artery are a special entity and the environment of the aneurysm within the sphenoid sinus may change over a long time. Coil embolization may lead to the late onset complication of coil migration with the possible risk of acute epistaxis. As a consequence, these patients need a careful and prolonged follow up. FD-CT is an appropriate technique to visualize the implanted coils and if present the migration of coil material.
[Show abstract][Hide abstract] ABSTRACT: The surgical strategy for spinal meningiomas usually consists of laminectomy, initial tumour debulking, identification of the interface between tumour and spinal cord, resection of the dura including the matrix of the tumour, and duroplasty. The objective of this study was to investigate whether a less invasive surgical strategy consisting of hemilaminectomy or laminectomy, tumour removal and coagulation of the tumour matrix allows comparable surgical and clinical results to be obtained, especially without an increase of the recurrence rate as reported in the literature.
Between 1990 and 2005, 61 patients (11 men, 50 women) underwent surgery for spinal meningioma. All patients were treated microsurgically by a posterior approach. In 56 of the 61 patients, the above outlined - less invasive - surgical technique with tumour removal and coagulation of the tumour matrix was performed. In 5 patients, dura resection and duroplasty was additionally performed. Electrophysiological monitoring was routinely used since 1996. Recurrence was defined as new onset or worsening of symptoms and radiological confirmation of tumour growth. The pre-and post-operative clinical status was measured by the Frankel grading system.
Pre-operatively, 40 patients were in Frankel grade D, 13 patients in grade C, 6 patients in grade E and 1 patient each in grade A and B. Following surgery no patient presented a permanent worsening of clinical symptoms. All patients who initially presented with a Frankel grades A-C (n = 15) recovered to a better grade at the time of follow-up. Patients who presented with Frankel grade D remained in stable condition (n = 27) or recovered to a better neurological status (n = 13). Two patients experienced a temporary worsening of their symptoms, but subsequently improved to a better state than pre-operatively. Two (3.3%) complications (pseudomeningocele, wound infection) requiring surgery, were encountered. The pseudomeningocele developed in a patient who underwent durotomy. During the follow-up period of 2 months to 10 years (mean 31.3 months), 3 patients (5%) required surgery for symptomatic recurrence: 1 patient had 2 recurrences that occurred 4 and 7 years after first tumour removal and matrix coagulation, 1 recurrence occurred 1 year after tumour removal that was accompanied by matrix coagulation in a patient with a diffuse anterocranial tumour extension and 1 occurred 3 years after tumour removal and durotomy. Two patients showed a small recurrence on MRI during follow-up after 2 and 5 years, respectively, without any symptoms requiring surgery.
The high rate of favourable clinical results combined with the low rate of recurrences supports our less invasive surgical concept, which does not aim for resection of the dural matrix of the spinal meningioma.
[Show abstract][Hide abstract] ABSTRACT: Spinal epidural abscess (SEA) is a rare disease and its early detection and appropriate treatment is essential to prevent high morbidity and mortality. There are only few single-institution series who report their experiences with the microsurgical management of SEA and treatment strategies are discussed controversially. Within the last 15 years the authors have treated 46 patients with SEA. This comparatively high number of cases encouraged us to review our experiences with SEA focussing on the clinical presentation, microsurgical management and outcome.
Clinical charts of 46 cases with a spinal epidural abscess treated between 1990 and 2004 were reviewed. There were 30 men and 16 women, the age ranged between 32 and 86 years (mean: 57 years). The clinical mean follow-up was 8.5 months (range: 2-84). The clinical presentation and severity of neurological deficits were measured by the Frankel grading system on admission and on follow-up visit.
The abscess was located in the cervical spine in 8, the thoracic spine in 17 and the lumbar spine in 21 patients. On admission 8 patients were in Frankel grade A, 7 in B, 15 in C, 8 in D and 8 in E. During follow-up 1 patient was in Frankel grade A, 1 in B, 5 in C, 13 in D and 24 in E. 37 patients underwent primary microsurgery with abscess drainage or removal of chronic granulomatous tissue. The clinical symptoms in 4 patients worsened shortly after the operation due to a compression fracture of the vertebral body (n=2) or progress of the abscess (n=2) making re-operation necessary. 9 patients with severe critical illness or without neurological deficits had primarily a CT-guided puncture for assessment of the causative organism. 3 of them needed additional surgical therapy within the hospital stay because of a new neurological deficit. All patients were immobilised and treated with antibiotics for at least 6 weeks. The mortality was 6.5%. As for complications we noted septicaemia (n=5), meningitis (n=1) and a transient malresorptive hydrocephalus (n=1).
Early diagnosis, microsurgical therapy with appropriate antibiotic therapy and careful observation of patients are the keys to successful management of SEA. The goal of surgical treatment is to isolate the causative organism and to perform a decompression at the site of maximal cord compression in cases of neurological deterioration or severe pain. Instrumentation with primary fixation does not seem to be imperative. In cases of post-operative worsening, a fracture of additionally infected bony elements has to be considered and a stabilisation should be discussed on an individual basis.
[Show abstract][Hide abstract] ABSTRACT: Fibrinolytic therapy for spontaneous intracerebral hemorrhage using recombinant tissue plasminogen activator (rtPA) is considered a viable alternative to microsurgical hematoma removal. However, experimental data suggest that rtPA is neurotoxic and evokes a late perihematomal edema. We present preliminary data focusing on the avoidance of late edema formation after lysis of an intracerebral hematoma in a porcine model.
Twenty pigs underwent placement of a frontal intracerebral hematoma with a minimum volume of 1 mL. Half of the pigs were subjected to rtPA clot lysis and MK-801 injection for blockage of the NMDA receptor-mediated rtPA-enhanced excitotoxic pathway. The remaining 10 pigs received desmoteplase (DSPA) for clot lysis, which is known to be a less neurotoxic fibrinolytic agent than rtPA. MRI on the day of surgery and on postoperative days 4 and 10 was used to assess hematoma and edema volumes.
Late edema formation could be prevented in both the MK-801/rtPA and DSPA pigs.
The benefits of fibrinolytic therapy for intracerebral hematomas appear to be counterbalanced by late edema formation. MK-801 infusion as an adjunct to rtPA lysis, or the use of DSPA instead of rtPA, prevents late edema and therefore has the potential to further improve results after clot lysis.
[Show abstract][Hide abstract] ABSTRACT: Minimal access spine surgery (MASS) is gaining increasing importance in microsurgery of the lumbar spine. From a current prospective series we present data on MASS for far lateral lumbar disc herniations (LLDH) via a transmuscular trocar technique (T(2)). The surgical procedure and operative results are demonstrated in detail. In contrast to conventional percutaneous endoscopic techniques, T(2) allows one to operate in the typical microsurgical fashion combined with the advantages of a minimal endoscopic approach with three-dimensional visualization of the surgical target using the operating microscope.
Microsurgery was performed through a 1.6-cm skin incision with an 11.5-mm diameter trocar that is obliquely inserted into the paraspinal muscles pointing at the lateral isthmus of the upper vertebral body. Fifteen patients were evaluated after a median follow-up period of 24 months. Overall outcome according to the modified MacNab criteria, effect of surgery on radicular pain and sensory or motor deficits, duration of surgery, complication rate, and duration of hospital stay were evaluated.
Good to excellent clinical outcomes were achieved in 14/15 patients. Radicular pain and motor deficits improved in all patients postoperatively, while sensory deficits recovered in 13/15 patients. The cosmetic results were excellent in all patients. No aggravation of symptoms after surgery was observed in any of the patients.
The T(2) technique represents an auspicious alternative to standard open microsurgery for LLDH, which allows achievement of excellent clinical and cosmetic results, preservation of segmental spine stability, and avoidance of excessive soft tissue trauma.
[Show abstract][Hide abstract] ABSTRACT: Nd:YAG, argon and diode lasers have been used in neurosurgical procedures including neuroendoscopy. However, many neurosurgeons are reluctant to use these lasers because of their inappropriate wavelength and uncontrollable tissue interaction, which has the potential to cause serious complications. Recently, a 2.0-microm near infrared laser with adequate wavelength and minimal tissue penetration became available. This laser was developed for endoscopic neurosurgical procedures. It is the aim of the study to report the initial experiences with this laser in neuroendoscopic procedures. We have performed 43 laser-assisted neuroendoscopic procedures [multicompartmental congenital, posthaemorrhagic or postinfectious hydrocephalus (n = 17), tumour biopsies (n = 6), rescue of fixed and allocated ventricular catheters (n = 2), endoscopic third ventriculostomy (ETV, n = 17) and aqueductoplasty (n = 1)] in 41 patients aged between 3 months and 80 years. The laser beam was delivered through a 365-microm bare silica fibre introduced through the working channel of a rigid endoscope. It was used for the opening of cysts, perforating the third ventricular floor, and for coagulation prior to and after biopsy. The therapeutic goals [creating unhindered cerebrospinal fluid (CSF) flow between cysts, ventricles and cisterns, sufficient tissue samples for histopathological diagnosis and catheter rescue] were achieved in 40 patients by the first and in 2 patients by a second neuroendoscopic operation. In one child, a CSF shunt was later required despite patency of the created stoma proven by magnetic resonance imaging (MRI). In another patient ETV was abandoned due to a tiny third ventricle. There was neither mortality nor transient or permanent morbidity. The authors conclude that the use of the 2.0-microm near infrared laser enables safe and effective procedures in neuroendoscopy.
[Show abstract][Hide abstract] ABSTRACT: Congenital plasminogen deficiency is an infrequent disorder, which usually becomes symptomatic as ligneous conjunctivitis. However, pseudomembranous lesions in the mucosa of the pharynx, tracheobronchial tree, and the peritoneum may likewise occur. An accompanying hydrocephalus is extremely rare; only 16 cases have been reported to date. The reports indicate that hydrocephalus, even if treated by ventriculoperitoneal (VP) cerebrospinal fluid (CSF) shunting, worsens the prognosis substantially. Thus, VP CSF shunting does not seem to be the optimal therapy for hydrocephalic children with plasminogen deficiency. We add two cases to the literature, and, on the base of our experience, we propose a management strategy for the hydrocephalus. We report the case history of two children with plasminogen deficiency and associated hydrocephalus. Both children initially were treated with VP shunts and had a very similar clinical course with multiple shunt malfunctions due to nonabsorption by the peritoneum. In the first child, the attempt to treat the hydrocephalus with a ventriculoatrial (VA) shunt failed due to catheter thrombosis. Finally, a ventriculocholecystic shunt was placed in both children, which worked well. In patients with plasminogem deficiency and associated hydrocephalus, special care must be taken in the management of hydrocephalus. The absorptive capacity of the peritoneum is reduced by pseudomembrane formation, which results in VP shunt malfunction. The plasminogen deficiency results in early thrombus formation if atrial catheters are used. Therefore, the authors believe that ventriculocholecystic shunting should be considered early on in the course of the disease.
European Journal of Pediatric Surgery 05/2007; 17(2):124-8. · 0.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The primary objective of neurophysiologic monitoring during surgery is to avoid permanent neurological injury resulting from surgical manipulation. To prevent motor deficits, either somatosensory (SSEP) or transcranial motor evoked potentials (MEP) are applied. This prospective study was conducted to evaluate if the combined use of SSEP and MEP might be beneficial. Combined SSEP/MEP monitoring was attempted in 100 consecutive procedures, including intracranial and spinal operations. Repetitive transcranial electric motor cortex stimulation was used to elicit MEP from muscles of the upper and lower limb. Stimulation of the tibial and median nerves was performed to record SSEP. Critical SSEP/MEP changes were defined as decreases in amplitude of more than 50% or increases in latency of more than 10% of baseline values. The operation was paused or the surgical strategy was modified in every case of SSEP/MEP changes. Combined SSEP/MEP monitoring was possible in 69 out of 100 operations. In 49 of the 69 operations (71%), SSEP/ MEP were stable, and the patients remained neurologically intact. Critical SSEP/ MEP changes were seen in six operations. Critical MEP changes with stable SSEP occurred in 12 operations. Overall, critical MEP changes were recorded in 18 operations (26%). In 12 of the 18 operations, MEP recovered to some extent after modification of the surgical strategy, and the patients either showed no (n = 10) or only a transient motor deficit (n = 2). In the remaining six operations, MEP did not recover and the patients either had a transient (n = 3) or a permanent (n = 3) motor deficit. Critical SSEP changes with stable MEP were observed in two operations; both patients did not show a new motor deficit. Our data again confirm that MEP monitoring is superior to SSEP monitoring in detecting impending impairment of the functional integrity of cerebral and spinal cord motor pathways during surgery. Detection of MEP changes and adjustment of the surgical strategy might allow to prevent irreversible pyramidal tract damage. Stable SSEP/MEP recordings reassure the surgeon that motor function is still intact and surgery can be continued safely. The combined SSEP/ MEP monitoring becomes advantageous, if one modality is not recordable.
[Show abstract][Hide abstract] ABSTRACT: Hemorrhages caused by hemangioblastomas are very rare and mostly located in the subarachnoid space. Intraparenchymal bleedings due to hemangioblastomas are even less frequent, and these hemorrhages are almost exclusively located in the supratentorial brain, cerebellum and spinal cord. We report the first case of a brainstem hemorrhage due to a hemangioblastoma of the medulla oblongata.
A 47-year-old woman presented with acute onset of headache, anarthria, inability to swallow, left-sided hemiparesis and hemidysesthesia with varying states of vigilance, finally developing acute respiratory failure. Cranial computed tomography (CT) scanning and magnetic resonance imaging (MRI) revealed a small hemangioblastoma of the posterior medulla oblongata causing intraparenchymal hemorrhage and acute occlusive hydrocephalus due to intraventricular hematoma extension.
After implantation of an external ventricular catheter to treat acute hydrocephalus, the hemangioblastoma as well as its associated hemorrhage could be removed in toto via a microsurgical posterior median suboccipital approach with minimal foramen magnum enlargement. During the follow-up period of six months postoperatively the patient showed good recovery with only slight residual neurological deficits.
The most common causes of brainstem hemorrhages are arterial hypertension and cavernous hemangiomas. However, hemangioblastomas should not be ignored as a possible differential diagnosis for intraparenchymal brainstem hemorrhage. While the prognosis in hypertensive brainstem bleedings is mostly disastrous and surgery rarely indicated, an operative therapy should be considered in cases of hemorrhages caused by underlying tumors. Especially in the treatment of hemangioblastoma, the surgical management strategy is crucial for a successful result. Therefore, the authors recommend including the search for hemangioblastomas into the diagnostic workup in patients with brainstem hemorrhages.
Zentralblatt für Neurochirurgie 03/2007; 68(1):29-33. · 0.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Optical coherence tomography (OCT) is a non-invasive and non-contact imaging technology that has been applied to several biomedical applications. We have recently demonstrated that OCT allows discrimination of tumor adjacent brain, diffuse and solid tumor tissue and that this technology may be used to detect residual tumor within the resection cavity during resection of intrinsic brain tumors. Here we show that an OCT integrated endoscope can image the endoventricular anatomy and other endoscopically accessible structures in a human brain specimen. A Sirius 713 optical coherence tomography device was mounted to a modified rigid endoscope. A formalin-fixed human brain specimen was used to simulate endoscopic visualization of brain anatomy and two specimens of fixed malignant tumors with endoventricular growth patterns. Simultaneous OCT imaging and endoscopic video imaging of the visible spectrum was possible using a graded index rod endoscope. OCT imaging of a human brain specimen in water allowed an in-depth view into structures like the walls of the ventricular system, the choroid plexus or the thalamostriatal vein. OCT further allowed imaging of structures beyond tissue barriers or opaque media. In this fixed specimen OCT allowed discrimination of vascular structures down to a diameter of 50 mum. In vessels larger that 100 mum the lumen could be discriminated and within larger blood vessels a layered structure of the vascular wall as well as endovascular plaques could be visualized. This in vitro pilot study has demonstrated that OCT integrated into neuroendoscopes may add information that cannot be obtained by the video imaging alone. This technology may provide an extra margin of safety by providing cross-sectional images of tissue barriers within optically opaque conditions.
[Show abstract][Hide abstract] ABSTRACT: In the living human brain the pyramidal tract (PT) can be displayed with magnetic resonance diffusion-weighted imaging (DWI). Although this imaging technique is already being used for planning and performing neurosurgical procedures in the PT vicinity, there is a lack of verification of DWI accuracy in other areas outside the directly subcortical PT parts. Before definitive electrode placement into the subthalamic nucleus (STN) in patients with Parkinson disease (PD) for chronic stimulation, the stimulation effect on PD symptoms and the side-effects, namely PT activation at the level of the internal capsule (IC), are electrophysiologically tested. To analyze DWI accuracy by matching the stereotactic coordinates of the electrophysiologically proven IC position with these of the DWI-derived IC display, DWI was added to the routine MRI work-up in the stereotactic frame prior to functional surgery in 6 patients. In all of the 10 displayed fiber tracts, concordant findings for imaging and macrostimulation were made. The authors proved for the first time that DWI correctly depicts the deep seated, principle motor pathways in the living human brain. Due to methodical limitations of this study the accuracy of the proven IC display is limited to 3 mm which has proven to be sufficient for the planning and performance of neurosurgical procedures in the vicinity of large fiber tracts.
Zentralblatt für Neurochirurgie 09/2006; 67(3):117-22. · 0.63 Impact Factor