Technical report: surgical preparation of human brain tissue for clinical and basic research.

BACKGROUND: The study of the distinct structure and function of the human central nervous system, both in healthy and diseased states, is becoming increasingly significant in the field of neuroscience. Typically, cortical and subcortical tissue is discarded during surgeries for tumors and epilepsy. Yet, there is a strong encouragement to utilize this tissue for clinical and basic research in humans. Here, we describe the technical aspects of the microdissection and immediate handling of viable human cortical access tissue for basic and clinical research, highlighting the measures needed to be taken in the operating room to ensure standardized procedures and optimal experimental results. METHODS: In multiple rounds of experiments (n = 36), we developed and refined surgical principles for the removal of cortical access tissue. The specimens were immediately immersed in cold carbogenated N-methyl-D-glucamine-based artificial cerebrospinal fluid for electrophysiology and electron microscopy experiments or specialized hibernation medium for organotypic slice cultures. RESULTS: The surgical principles of brain tissue microdissection were (1) rapid preparation (<1 min), (2) maintenance of the cortical axis, (3) minimization of mechanical trauma to sample, (4) use of pointed scalpel blade, (5) avoidance of cauterization and blunt preparation, (6) constant irrigation, and (7) retrieval of the sample without the use of forceps or suction. After a single round of introduction to these principles, multiple surgeons adopted the technique for samples with a minimal dimension of 5 mm spanning all cortical layers and subcortical white matter. Small samples (5-7 mm) were ideal for acute slice preparation and electrophysiology. No adverse events from sample resection were observed. CONCLUSION: The microdissection technique of human cortical access tissue is safe and easily adoptable into the routine of neurosurgical procedures. The standardized and reliable surgical extraction of human brain tissue lays the foundation for human-to-human translational research on human brain tissue.

Piezosurgery for safe and efficient petrous bone cutting in cerebellopontine angle and petroclival meningioma surgery.

Intradural petrous bone drilling has become a widespread practice, providing extended exposure in the removal of cerebellopontine angle (CPA) or petroclival tumors. Adjacent neurovascular structures are at risk, however, when drilling is performed in this deep and narrow area. Hence, this study evaluates the use of Piezosurgery (PS) as a non-rotating tool for selective bone cutting in CPA surgery. A Piezosurgery® device was used in 36 patients who underwent microsurgery for extra-axial CPA or petroclival tumors in our Neurosurgical Department between 2013 and 2019. The clinical and radiological data were retrospectively analyzed. The use of PS was evaluated with respect to the intraoperative applicability and limitations as well as efficacy and safety of the procedure. Piezosurgical petrous bone cutting was successfully performed in the removal of meningiomas or extra-axial metastases arising from the dura of the petroclival region (21 patients) or petrous bone (15 patients). PS proved to be very helpful in the deep and narrow CPA region, considerably reducing the surgeon's distress toward bone removal in close proximity to cranial nerves and vessels in comparison to common rotating drills. The use of PS was safe without injuries to neurovascular structures. Gross total resection was achieved in 67% of petroclival and 100% of petrous bone tumors. Piezosurgery proved to be an effective and safe method for selective petrous bone cutting in CPA surgery avoiding rotating power and associated risks. This technique can particularly be recommended for bone cutting in close vicinity to critical neurovascular structures.

Colonic volvulus after laparoscopic left colectomy.

Volvulus of the mobilized colon after laparoscopic left colectomy is rare. Contributing factors seem to be excessive length of the mobilized colon, absence of peritonization and absence of adhesions due to laparoscopy. Onset of colonic volvulus after laparoscopic left colectomy should lead to routine computerized tomography (CT), searching for an image suggestive of small intestinal incarceration under the neo-mesocolon, which might be an additional risk factor. Treatment consists of disincarceration of the small intestines while closing the mesocolic defect remains a subject of controversy.

A rare Foreign Body in the bladder: a surgical dressing as a bladder stone.

We report an unusual case of a foreign body removed from the urinary bladder of an 11-year-old boy, which had mimicked a recurrent bladder stone. The diagnosis was suspected by ultrasound. As the clinical presentation appeared typical, no other examination was performed. Open surgery revealed that this foreign body was a surgical dressing forgotten during the first surgery eight years earlier. The absence of clinical evidence or infectious complications related to this foreign body over such a long period was surprising.

Xanthogranulomatous cholecystitis: a rare cause of digestive hemorrhage.

Xanthogranulomatous cholecystitis is a rare affection with non-specific symptoms. It is essential to differentiate it from gall bladder adenocarcinoma. Presentation signs include hemorrhage or fistula. This report concerns a patient with pseudotumoral xanthogranulomatous cholecystitis who presented with gastrointestinal hemorrhage.

First experience using navigation-guided radiofrequency kyphoplasty for sacroplasty in sacral insufficiency fractures.

PURPOSE: To evaluate the efficacy and safety of navigation-guided radiofrequency kyphoplasty for sacroplasty in patients with sacral insufficiency fractures. METHODS: In this single-center retrospective observational study, four consecutive patients with sacral insufficiency fractures were treated with navigation-guided radiofrequency kyphoplasty for sacroplasty between April 2010 and May 2012. Symptom characteristics, pain duration and pain intensity were recorded for each patient. Cement extravasation was evaluated in thin-sliced and triplanar reconstructed CT scans of the sacrum. RESULTS: Four female patients with painful sacral insufficiency fractures and extensive osteopenic areas significantly improved from an average pre-treatment VAS score of 8.3 ± 0.5 to 2.3 ± 1.0 (p < 0.001) on the first postoperative day and to 1.3 ± 1.9 (p < 0.004) at follow-up (mean, 20.1 weeks). Slight cement extravasations were observed without evidence of being symptomatic. No major complications or procedure-related morbidity were noted. CONCLUSION: From the limited experience in four patients, navigation-guided radiofrequency kyphoplasty appears to be a safe and effective treatment option for sacral insufficiency fractures even though asymptomatic cement extravasation was noted. The use of navigation based on intraoperative 3 D images simplifies the positioning of the navigated bone needles via the long axis approach. The radiofrequency kyphoplasty system provides the possibility to administer a sufficient amount of bone cement with a well-defined viscosity over the entire period of the procedure leading to high security and low cement extravasation. Sacroplasty provides rapid and enduring pain relief and facilitates prompt mobilization.

Vesselplasty: a new minimally invasive approach to treat pathological vertebral fractures in selected tumor patients - preliminary results.

PURPOSE: To evaluate the effectiveness and safety of percutaneous vesselplasty in pathological vertebral fractures of the thoracolumbar spine in selected tumor patients. MATERIALS AND METHODS: Eleven pathological vertebral fractures in nine patients were treated with vesselplasty (Vessel-X®, MAXXSPINE). Nine of eleven vertebras (81.8 %) had major posterior wall deficiency (> 30 %). Clinical and radiological (CT) measures were obtained before and 3 months after the procedure. RESULTS: The mean VAS improved significantly from preoperative to postoperative (6.9 ± 2.2 to 3.7 ± 2.3; p < 0.05), as did the ODI (59.7 %± 19.2 % to 40.3 %± 24.0 %; p < 0.05). The physical component summary of the SF-36 was significantly improved by the operation (19.2 ± 8.0 to 31.0 ± 16.5; p < 0.05). Symptomatic cement leakage or other operation-associated complications were not observed. Three patients were primarily treated with concomitant minimally invasive stabilization via fixateur interne. One patient had to undergo minimally invasive stabilization via fixateur interne 4 months after vesselplasty due to further collapse of the treated vertebral body. CONCLUSION: From these preliminary results, vesselplasty appears to be a treatment option worth considering in pathological vertebral fractures, even in the case of posterior wall deficiency. Selected tumor patients might benefit from vesselplasty as a minimally invasive procedure for stabilization of the fractured vertebra, pain control, and improvement in body function and quality of life. Long-term prospective studies with a larger sample size are required to validate these results.

Late bacterial granuloma at an intrathecal drug delivery catheter.

In the case reported, neurological complaints were pain and dysaesthesiae in the lower back and thigh, as well as paresis of the ileopsoas muscle. MRI of the lumbar spine showed an intradural-extramedullary mass at the level of L1 homogeneously enhancing with gadolinium. This mass was situated at the tip of an intrathecal catheter implanted 11 years before for a morphine trial infusion as therapy for phantom pain after amputation of the right arm. Now, removal of the catheter was performed. Cultures of lumbar CSF and the catheter tip demonstrated coagulase negative staphylococcus. Antibiotic medication with cephalosporines was given for 6 weeks. After removal of the catheter, the patient was free of pain and he progressively regained full neurological function. Although most catheter-associated granulomas reported so far were sterile in nature, bacterial infection should still be considered even years after catheter placement.

Temporal lobe epilepsy associated up-regulation of metabotropic glutamate receptors: correlated changes in mGluR1 mRNA and protein expression in experimental animals and human patients.

Aberrant axonal reorganization and altered distribution of neurotransmitter receptor subtypes have been proposed as major pathogenic mechanisms for hippocampal hyperexcitability in chronic temporal lobe epilepsies (TLE). Recent data point to excitatory class I metabotropic glutamate receptors (mGluR1 and mGluR5) as interesting candidates. Here, we have analyzed the hippocampal distribution and mRNA expression of mGluR1 and mGluR5 in two rat models of limbic seizures, i.e. electrical kindling and intraperitoneal kainate injections, as well as in human TLE. Quantitative RT-PCR analysis detected a significant increase of hippocampal mGluR1 gene transcript levels in kainate treated and kindled rats. In addition, microdissected hippocampal tissue samples localized this increase to the dentate gyrus. Using immunohistochemistry with mGluR1alpha subtype specific antibodies, increased labeling was observed within the dentate gyrus molecular layer (DG-ML). A similar pattern of increased mGluR1alpha neuropil staining was found within the DG-ML of epilepsy patients (n = 42) compared with peritumoral hippocampus specimens obtained from nonepileptic patients (biopsy controls, n = 3). This increase was detected in TLE patients with segmental hippocampal cell loss, as well as in TLE patients with focal lesions but no histopathological alterations of the hippocampus. In contrast, mGluR5 immunoreactivity and mRNA expression were not significantly altered in the DG-ML. Our data demonstrate a striking regional induction of mGluR1alpha in the hippocampal dentate gyrus of experimental animals with limbic seizures as well as in human patients with chronic, intractable TLE. This increase corresponds to functional alterations of class I mGluRs observed in seizure models and may significantly contribute to hippocampal hyperexcitability in focal human epilepsies.