The telovelar approach for fourth ventricular tumors in children: is removal of the posterior arch of C1 necessary?

PURPOSE: Various surgical nuances of the telovelar approach have been suggested. The necessity of removing the posterior arch of C1 to accomplish optimal tumor exposure is still debated. Therefore, we report on our experience and technical details of the fourth ventricular tumor resection in a modified prone position without systematic removal of the posterior arch of C1. METHODS: A retrospective analysis of all pediatric patients, who underwent a fourth ventricular tumor resection in the modified prone position between 2012 and 2021, was performed. RESULTS: We identified 40 patients with a median age of 6 years and a M:F ratio of 25:15. A telovelar approach was performed in all cases. In 39/40 patients, the posterior arch of C1 was not removed. In the remaining patient, the reason for removing C1 was tumor extension below the level of C2 with ventral extension. Gross or near total resection could be achieved in 34/39 patients, and subtotal resection in 5/39 patients. In none of the patients, a limited exposure, sight of view, or range of motion caused by the posterior arch of C1 was encountered, necessitating an unplanned removal of the posterior arch of C1. Importantly, in none of the cases, the surgeon had the impression of a limited sight of view to the most rostral parts of the fourth ventricle, which necessitated a vermian incision. CONCLUSION: A telovelar approach without the removal of the posterior arch of C1 allows for an optimal exposure of the fourth ventricle provided that critical nuances in patient positioning are considered.

Retrospective comparison of percutaneous balloon compression and radiofrequency-thermocoagulation in the management of trigeminal neuralgia.

PURPOSE: To compare percutaneous balloon compression (PBC) and radiofrequency thermocoagulation (RFTC) for the treatment of trigeminal neuralgia. METHODS: This was a retrospective single-center analysis of data from 230 patients with trigeminal neuralgia who underwent 202 PBC (46%) and 234 RFTC (54%) from 2002 to 2019. Comparison of demographic data and trigeminal neuralgia characteristics between procedures as well as assessment of 1) initial pain relief by an improved Barrow Neurological Institute (BNI) pain intensity scale of I-III; 2) recurrence-free survival of patients with a follow-up of at least 6 months by Kaplan-Meier analysis; 3) risk factors for failed initial pain relief and recurrence-free survival by regression analysis; and 4) complications and adverse events. RESULTS: Initial pain relief was achieved in 353 (84.2%) procedures and showed no significant difference between PBC (83.7%) and RFTC (84.9%). Patients who suffered from multiple sclerosis (odds ratio 5.34) or had a higher preoperative BNI (odds ratio 2.01) showed a higher risk of not becoming pain free. Recurrence-free survival in 283 procedures was longer for PBC (44%) with 481 days compared to RFTC (56%) with 421 days (p=0.036) but without statistical significance. The only factors that showed a significant influence on longer recurrence-free survival rates were a postoperative BNI ≤ II (P=<0.0001) and a BNI facial numbness score ≥ 3 (p = 0.009). The complication rate of 22.2% as well as zero mortality showed no difference between the two procedures (p=0.162). CONCLUSION: Both percutaneous interventions led to a comparable initial pain relief and recurrence-free survival with a low and comparable probability of complications. An individualized approach, considering the advantages and disadvantages of each intervention, should guide the decision-making process. Prospective comparative trials are urgently needed.

Feasibility of intraoperative motor evoked potential monitoring during tethered cord surgery in infants younger than 12 months.

PURPOSE: Feasibility, reliability, and safety assessment of transcranial motor evoked potentials (MEPs) in infants less than 12 months of age. METHODS: A total of 22 patients with a mean age of 33 (range 13-49) weeks that underwent neurosurgery for tethered cord were investigated. Data from intraoperative MEPs, anesthesia protocols, and clinical records were reviewed. Anesthesia during surgery was maintained by total intravenous anesthesia (TIVA). RESULTS: MEPs were present in all patients for the upper extremities and in 21 out of 22 infants for the lower extremities. Mean baseline stimulation intensity was 101 ± 20 mA. If MEPs were present at the end of surgery, no new motor deficit occurred. In the only case of MEP loss, preoperative paresis was present, and high baseline intensity thresholds were needed. MEP monitoring did not lead to any complications. TIVA was maintained with an average propofol infusion rate of 123.5 ± 38.2 µg/kg/min and 0.46 ± 0.17 µg/kg/min for remifentanil. CONCLUSION: In spinal cord release surgery, the use of intraoperative MEP monitoring is indicated regardless of the patient's age. We could demonstrate the feasibility and safety of MEP monitoring in infants if an adequate anesthetic regimen is applied. More data is needed to verify whether an irreversible loss of robust MEPs leads to motor deficits in this young age group.

New-onset seizures after cranioplasty-a different view on a putatively frequently observed phenomenon.

BACKGROUND: New-onset seizures after cranioplasty (NOSAC) are reported to be a frequent complication of cranioplasty (CP) after decompressive hemicraniectomy (DHC). There are considerable differences in the incidence of NOSAC and contradictory data about presumed risk factors in the literature. We suggest NOSAC to be a consequence of patients' initial condition which led to DHC, rather than a complication of subsequent CP. We conducted a retrospective analysis to verify our hypothesis. METHODS: The medical records of all patients ≥ 18 years who underwent CP between 2002 and 2017 at our institution were evaluated including incidence of seizures, time of seizure onset, and presumed risk factors. Indication for DHC, type of implant used, timing of CP, patient age, presence of a ventriculoperitoneal shunt (VP shunt), and postoperative complications were compared between patients with and without NOSAC. RESULTS: A total of 302 patients underwent CP between 2002 and 2017, 276 of whom were included in the outcome analysis and the incidence of NOSAC was 23.2%. Although time between DHC and CP differed significantly between DHC indication groups, time between DHC and seizure onset did not differ, suggesting the occurrence of seizures to be independent of the procedure of CP. Time of follow-up was the only factor associated with the occurrence of NOSAC. CONCLUSION: New-onset seizures may be a consequence of the initial condition leading to DHC rather than of CP itself. Time of follow-up seems to play a major role in detection of new-onset seizures.

Cranioplasty following ventriculoperitoneal shunting: lessons learned.

OBJECTIVE: Cranioplasty (CP) is considered as a straightforward and technically unchallenging operation; however, complication rates are high reaching up to 56%. Presence of a ventriculoperitoneal shunt (VPS) and timing of CP are reported risk factors for complications. Pressure gradients and scarring at the site of the cranial defect seem to be critical in this context. The authors present their experiences and lessons learned. METHODS: A consecutive series of all patients who underwent CP at the authors' institution between 2002 and 2017 were included in this retrospective analysis. Complications were defined as all events that required reoperation. Logistic regression analysis and chi-squared test were conducted to evaluate the complication rates according to suspected risk factors. RESULTS: A total of 302 patients underwent cranioplasty between 2002 and 2017. The overall complication rate was 17.5%. Complications included epi-/subdural fluid collection (7.3%) including hemorrhage (4.6%) and hygroma (2.6%), bone graft resorption (5.3%), bone graft infection (2.0%), and hydrocephalus (5.7%). Overall, 57 patients (18.9%) had undergone shunt implantation prior to CP. The incidence of epi-/subdural fluid collection was 19.3% in patients with VPS and 4.5% in patients without VPS, OR 5.1 (95% CI 2.1-12.4). Incidence of hygroma was higher in patients who underwent early CP. Patients with temporary shunt ligation for CP did not suffer from complications. CONCLUSION: CP in patients with a VPS remains a high-risk procedure. Any effort to understand the pressure dynamics and to reduce factors that may trigger the formation of a large epidural space must be undertaken.

Microvascular decompression in trigeminal neuralgia: predictors of pain relief, complication avoidance, and lessons learned.

OBJECTIVE: To analyze characteristics associated with long-term pain relief after microvascular decompression (MVD) for trigeminal neuralgia (TGN). Description of associated morbidity and complication avoidance. METHODS: One hundred sixty-five patients with TGN underwent 171 MVD surgeries at the authors' institution. Patient characteristics and magnetic resonance imaging (MRI) datasets were obtained through the hospital's archiving system. Patients provided information about pre- and post-operative pain characteristics and neurologic outcome. Favorable outcome was defined as a Barrow Neurological Institute (BNI) pain intensity score of I to III with post-operative improvement of I grade. RESULTS: Type of TGN pain with purely paroxysmal pain (p = 0.0202*) and TGN classification with classical TGN (p = 0.0372*) were the only significant predictors for long-term pain relief. Immediate pain relief occurred in 90.6% of patients with a recurrence rate of 39.4% after 3.5 ± 4.6 years. MRI reporting of a neurovascular conflict had a low negative predictive value of 39.6%. Mortality was 0% with major complications observed in 8.2% of patients. Older age was associated with lower complication rates (p = 0.0009***). Re-MVD surgeries showed improved long-term pain relief in four out of five cases. CONCLUSIONS: MVD is a safe and effective procedure even in the elderly. It has the unique potential to cure TGN if performed on a regular basis, and if key surgical steps are respected. Early MVD should be offered in case of medical treatment failure and paroxysmal pain symptoms. The presence of a neurovascular conflict on MRI is not mandatory. In case of recurrence, re-MVD is a good treatment option that should be discussed with patients. HIGHLIGHTS: • Long-term analysis of pain relief after MVD. • Positive predictors for outcome: classical TGN and purely paroxysmal pain. • Presence of neurovascular conflict in MRI is not mandatory for MVD surgery. • Analysis of complications and surgical nuances for avoidance. • MVD is a safe procedure also in the elderly.

Critical Care EEG.

Neuromonitoring by means of continuous EEG (cEEG) has been increasingly used in intensive care patients. Standardized EEG criteria can be used to reliably detect and distinguish nonconvulsive seizures or status epileptici as well as rhythmic and periodic ictal-interictal continuum EEG patterns. Likewise, cerebral ischemia can be detected early by means of cEEG, and sedation and therapy management can be monitored and controlled.

Early Epileptiform Discharges and Clinical Signs Predict Nonconvulsive Status Epilepticus on Continuous EEG.

BACKGROUND: Critical care continuous electroencephalography (CCEEG) represents the gold standard for detection of nonconvulsive status epilepticus (NCSE) in neurological critical care patients. It is unclear which findings on short-term routine EEG and which clinical parameters predict NCSE during subsequent CCEEG reliably. The aim of the present study was to assess the prognostic significance of changes within the first 30 min of EEG as well as of clinical parameters for the occurrence of NCSE during subsequent CCEEG. METHODS: Systematic analysis of the first 30 min and the remaining segments of prospective CCEEG recordings according to the ACNS Standardized Critical Care EEG Terminology and according to recently proposed NCSE criteria as well as review of clinical parameters of 85 consecutive neurological critical care patients. Logistic regression and binary classification tests were used to determine the most useful parameters within the first 30 min of EEG predicting subsequent NCSE. RESULTS: The presence of early sporadic epileptiform discharges (SED) and early rhythmic or periodic EEG patterns of "ictal-interictal uncertainty" (RPPIIIU) (OR 15.51, 95% CI 2.83-84.84, p = 0.002) and clinical signs of NCS (OR 18.43, 95% CI 2.06-164.62, p = 0.009) predicted NCSE on subsequent CCEEG. Various combinations of early SED, early RPPIIIU, and clinical signs of NCS showed sensitivities of 79-100%, specificities of 49-89%, and negative predictive values of 95-100% regarding the incidence of subsequent NCSE (p < 0.001). CONCLUSIONS: Early SED and early RPPIIIU within the first 30 min of EEG as well as clinical signs of NCS predict the occurrence of NCSE during subsequent CCEEG with high sensitivity and high negative predictive value and may be useful to select patients who should undergo CCEEG.

An experimental animal model for percutaneous procedures used in trigeminal neuralgia.

OBJECT: This study describes an experimental rabbit model that allows the reproduction of percutaneous operations that are used in patients with trigeminal neuralgia (TN). Attention was given to an exact anatomical description of the rabbit's middle cranial fossa as well as the establishment of conditions for a successful procedure. METHODS: Morphometric measurements were taken from 20 rabbit skulls and CT scans. The anatomy of the trigeminal nerve, as well as its surrounding structures, was assessed by bilateral dissection of 13 New Zealand white rabbits (NWR). An ideal approach of placing a needle through the foramen ovale to reach the TG was sought. Validation of correct placement was realized by fluoroscopy and confirmed by dissection. RESULTS: Precise instructions for successful reproduction of percutaneous procedures in NWR were described. According to morphological measurements, for balloon compression of the trigeminal ganglion (TG) the maximal diameter of an introducing cannula is 1.85 mm. The diameter of an empty balloon catheter should not exceed 1.19 mm, and the length of the inflatable part of the balloon can range up to 4 mm. For thermocoagulation the needle electrodes must not exceed an external diameter of 1.39, mm and the length of the non-insolated tip can range up to 4 mm. Glycerol rhizolysis can be achieved because the trigeminal cistern in the NWR is a closed space that allows a long dwelling time (>10 min) of the contrast agent. CONCLUSIONS: An experimental NWR model intended for the reproduction of percutaneous procedures on the TG has been meticulously described. This provides a tool that enables further standardized animal research in the field of surgical treatment of TN.

Use of a 3D exoscope in microvascular decompression of the trigeminal nerve root.

For microvascular decompression surgery, adequate visualization of the trigeminal nerve root is essential. Several visualization techniques with operating microscopes, endoscopes, a combination of both, and exoscopes have been described. In this video, the authors use a 4K 3D exoscope (ORBEYE) as it offers superb optical image quality with a high degree of magnification and illumination in the cerebellopontine angle. Other advantages are surgeon ergonomics, a very good depth of field for the entire operating team, and potentially evolving visualization technologies like narrow-band imaging-essential points for microvascular decompression surgery where the aim is to create the best possible visibility in a narrow corridor. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23149.

The value of cryoablation in orbital surgery.

Aim of this article is to give an overview of the technical background and the advantages of modern devices for different applications of cryoablation in cranio-orbital neurosurgery.The treatment of orbital lesions is complicated by the complex and potentially inapparent anatomy due to retro-orbital fat. With the help of cryoprobes different well-defined lesions such as cavernous venous malformations can be safely and effectively removed thanks to the cryoadhesive effect. Their use has been described in several different approaches including traditional lateral or transcranial orbitotomy but also anterior transconjunctival as well as transnasal endoscopic approaches. Recently, single-use devices were introduced that allow the use of cryosurgery also without the need for large investment or service costs.

Risk factors for unfavorable outcome after spontaneous intracerebral hemorrhage in elderly patients.

BACKGROUND: Spontaneous intracerebral hemorrhage (SICH) of the elderly is a devastating form of stroke with a high morbidity and economic burden. There is still a limited understanding of the risk factors for an unfavorable outcome where a surgical therapy may be less meaningful. Thus, the aim of this study is to identify factors associated with unfavorable outcome and time to death in surgically treated elderly patients with SICH. METHODS: We performed a single-center retrospective study of 70 patients (age > 60 years) with SICH operated between 2008 and 2020. Functional outcome was assessed by modified Rankin Scale. Various clinical and neuroradiological variables including type of neurosurgical treatment, anatomical location of hemorrhage, volumetry and distribution of hemorrhage were assessed. Univariate and multivariate logistic regression models were performed. Length of stay (LOS) and hospital costs are presented. RESULTS: The overall mortality (mean follow-up time of 22 months) in this study was 32/70 patients (45.71%), 30-days mortality was 8/70 (11.42%), and 12-months mortality was 22/70 (31.43%). Average LOS was 73.5 days with a median of 58, 766 € estimated in hospital costs per patient. Multivariate analysis for 12-months mortality was significant for intraventricular hemorrhage (IVH) (p = 0.007, HR = 1.021, 95% CI = 1.006 - 1.037). ROC analysis for 12-months mortality for IVH volume >= 7 cm3 presented an are under the curve of 0.658. CONCLUSIONS: We identified IVH volume > 7 cm3 as an independent prognostic risk factor for mortality in elderly patients after SICH. This may help clinicians in decision-making for this critical and growing subgroup of patients.

The effect of perioperative non-steroidal anti-inflammatory drugs and male sex on the recurrence rates after chronic subdural hematoma evacuation.

BACKGROUND: Drugs that inhibit blood clot formation are a risk factor for the development and recurrence of chronic subdural hematoma (cSDH). The use of non-steroidal anti-inflammatory drug (NSAID) was associated with higher bleeding rates in non-neurosurgical patients, but their influence on cranial hematomas is unclear. We sought to better describe the hazard associated with their use in cSDH patients and find additional risk factors. METHODS: We performed a retrospective analysis of patients undergoing burr hole drainage for cSDH over a period of 15 years. Demographic and surgical details were extracted from individual patient records. Patients were followed for up to 90 days with SDH recurrence requiring repeat surgery as the primary endpoint. Univariate and multivariate Cox regression models were performed to identify risk factors and their effect size. RESULTS: We included 361 patients, who underwent burr hole drainage for cSDH. Recurrences occurred in 73 patients (20.2%) after a median time period of 18 days. Sixty-six patients in our cohort were taking NSAIDs perioperatively. The recurrence rate was not higher in NSAID users compared to other patients with 18.2% and 20.7%, respectively. 23.5% of men, yet only 12.7% of women had recurrences revealing male sex as a risk factor in a uni- and multivariate regression. Not placing a drain was a risk factor for early recurrences, which resulted in a prolonged hospital stay. CONCLUSIONS: We identified male sex as a risk factor for cSDH recurrence after burr hole drainage, while perioperative NSAID use did not increase recurrence rates.

Predicting the need for cerebrospinal fluid shunt implantation after spontaneous intracerebral hemorrhage: a challenging task.

Objectives: The development of persistent hydrocephalus in patients after spontaneous intracerebral hemorrhage (ICH) is still poorly understood, and many variables predicting the need for a cerebrospinal fluid (CSF)-shunt have been described in the literature with varying results. The aim of this study is to find predictive factors for shunt dependency. Methods: We performed a retrospective, single-center study of 99 neurosurgically treated patients with spontaneous ICH. Variables, including age, Glasgow Coma Scale (GCS), intraventricular hemorrhage (IVH), location of hemorrhage, acute hydrocephalus, and volumetric analysis of IVH, ICH, and intraventricular CSF were compared between patients with and without CSF-shunt implantation. Furthermore, receiver operating characteristics (ROC) for ICH, IVH, and intraventricular CSF volume parameters were calculated. Results: CSF-shunt implantation was performed significantly more often in patients after thalamic (p = 0.03) and cerebellar ICH (p = 0.04). Moreover, a lower ratio between the total hemorrhage volume and intraventricular CSF volume (p = 0.007), a higher IVH distribution in the third ventricle, and an acute hydrocephalus (p < 0.001) with an increased intraventricular CSF volume (p < 0.001) were associated with shunt dependency. Our ROC model demonstrated a sensitivity of 82% and a specificity of 65% to predict the necessity for a shunt at a cutoff value of 1.9 with an AUC of 0.835. Conclusion: Volumetric analysis of ICH, IVH, and intraventricular CSF may improve the prediction of CSF shunt implantation in patients with spontaneous ICH.

The Effect of Oral Nimodipine on Cerebral Metabolism and Hemodynamic Parameters in Patients Suffering Aneurysmal Subarachnoid Hemorrhage.

INTRODUCTION: Nimodipine is routinely administered to aneurysmal subarachnoid hemorrhage patients to improve functional outcomes. Nimodipine can induce marked systemic hypotension, which might impair cerebral perfusion and brain metabolism. METHODS: Twenty-seven aneurysmal subarachnoid hemorrhage patients having multimodality neuromonitoring and oral nimodipine treatment as standard of care were included in this retrospective study. Alterations in mean arterial blood pressure (MAP), cerebral perfusion pressure (CPP), brain tissue oxygen tension (pbtO2), and brain metabolism (cerebral microdialysis), were investigated up to 120 minutes after oral administration of nimodipine (60 mg or 30 mg), using mixed linear models. RESULTS: Three thousand four hundred twenty-five oral nimodipine administrations were investigated (126±59 administrations/patient). After 60 mg of oral nimodipine, there was an immediate statistically significant (but clinically irrelevant) drop in MAP (relative change, 0.97; P<0.001) and CPP (relative change: 0.97; P<0.001) compared with baseline, which lasted for the whole 120 minutes observation period (P<0.001). Subsequently, pbtO2 significantly decreased 50 minutes after administration (P=0.04) for the rest of the observation period; the maximum decrease was -0.6 mmHg after 100 minutes (P<0.001). None of the investigated cerebral metabolites (glucose, lactate, pyruvate, lactate/pyruvate ratio, glutamate, glycerol) changed after 60 mg nimodipine. Compared with 60 mg nimodipine, 30 mg induced a lower reduction in MAP (relative change, 1.01; P=0.02) and CPP (relative change, 1.01; P=0.03) but had similar effects on pbtO2 and cerebral metabolism (P>0.05). CONCLUSIONS: Oral nimodipine reduced MAP, which translated into a reduction in cerebral perfusion and oxygenation. However, these changes are unlikely to be clinically relevant, as the absolute changes were minimal and did not impact cerebral metabolism.

Where to Draw Cerebrospinal Fluid from an External Ventricular Drain? Comparison of Cerebrospinal Fluid Parameters between Two Different Collection Sites.

BACKGROUND: High cerebrospinal fluid (CSF) sampling frequency is considered a risk factor for external ventricular drain (EVD)-associated infections. To reduce manipulation at the proximal port and potentially minimize the risk of an infection, we aimed to analyze whether CSF parameters sampled from the far distal collection bag could provide reliable results compared to the proximal port. METHODS: We included patients who were treated with an EVD at our neurosurgical intensive care unit (ICU) between June 2021 and September 2022. CSF sampling, including microbiological analysis, was performed simultaneously from the proximal port and the collection bag. Spearman's correlation coefficients were calculated to assess the correlation of CSF cell count, protein, lactate and glucose between the two sample sites. RESULTS: We analyzed 290 pairs of CSF samples in 77 patients. Ventriculitis was identified in 4/77 (5%) patients. In 3/4 patients, microbiological analysis showed the same bacterial species at both sample sites at the same time. Spearman's correlation coefficient showed that CSF cell count (r = 0.762), lactate (r = 0.836) and protein (r = 0.724) had a high positive correlation between the two collection sites, while CSF glucose (r = 0.663) showed a moderate positive correlation. CONCLUSION: This study shows that biochemical CSF parameters can be reliably assessed from the EVD collection bag.

Technical Note: Advantages of a 2-Room Intraoperative 3-Tesla Magnetic Resonance Imaging Operating Suite for Performing Laser Interstitial Thermal Therapy in Pediatric Epilepsy and Tumor Surgery.

OBJECTIVE: Magnetic resonance thermography-guided laser interstitial thermal therapy (LITT) provides a minimally invasive treatment option in children with central nervous system tumors or medically intractable epilepsy. However, transporting anesthetized children between an operating room (OR) and a radiologic suite creates logistical challenges. Thus we describe advantages of using a 2-room intraoperative magnetic resonance imaging (MRI) concept for LITT. METHODS: Patients were pinned in a head frame that doubles as the lower part of the MRI head coil. Preoperative MRI was performed for accurate neuronavigation, after which laser fibers were stereotactically implanted. Transport between OR and MRI was achieved by sliding the top of the OR table onto a trolly. RESULTS: We performed 12 procedures in 11 children, mean age 7.1 years (range: 2 to 14 years). Ten children suffered from medically intractable epilepsy, and 1 child had a pilocytic midbrain astrocytoma. Two fibers were placed in 8 and 1 fiber in 4 procedures. Mean entry point and target errors were 2.8 mm and 3.4 mm, respectively. Average transfer time from OR to MRI and vice versa was 9 minutes (±1 minute, 40 seconds). Altogether, 50% of the seizure patients were seizure free (Engel grade I) at 22 months' follow-up time. One hemorrhagic event, which could be managed nonoperatively, occurred. We recorded no surgical site or intracranial infections. CONCLUSIONS: All LITT procedures were successfully carried out with head frame in the sterile environment. The intraoperative MRI suite proved to be advantageous for minimally invasive procedures, especially in young children resulting in short transports while maintaining high accuracy and safety.

Incidence, risk factors, and treatment of incidental durotomy during decompression in degenerative lumbar spine conditions.

BACKGROUND: The purpose of this study was to identify independent risk factors for incidental durotomy (ID) during decompressive lumbar spine surgery, and to describe its treatment. METHODS: This retrospective review includes 650 patients who underwent lumbar decompression at a tertiary institution between January 2015 and October 2019. Data collection was obtained through one independent researcher. The incidence rate and treatment of ID was evaluated by a chart review of operative notes, patient charts, physiotherapy reports, and nursing reports. RESULTS: The incidence rate of ID was 12.6%. The most common reason for admission was disc herniation (63.2%), followed by vertebral stenosis (22.1%). ID resulted in significantly longer operation time (P=0.0001) and length of hospitalization (P=0.0001). A correlation between ID and patient's diagnosis (P=0.0078) as well as the chosen type of surgery (P=0.0404) with an Odds Ratio to cause ID of 1.9 for laminectomy and 1.6 for undercutting compared to microdiscectomy were found. However, age, sex, surgeon experience, lumbar level, revision surgery, as well as multilevel surgery were not significantly correlated with the incidence of ID. Dural tears were closed with dural sealant (47.2%), polyester 4-0 sutures (11.1%) or a combination of both (37.5%) and the majority of patients had bed rest of at least two days. By usage of these treatment methods no patient needed reoperation. CONCLUSIONS: Diagnosis of vertebrostenosis as well as laminectomy were significantly correlated with the incidence of ID. Treatment with intraoperative closure and postoperative bed rest even though not standardized led to complication free outcomes.

Technical Assessment of Microvascular Decompression for Trigeminal Neuralgia Using a 3-Dimensional Exoscope: A Case Series.

BACKGROUND: Detailed anatomic visualization of the root entry zone of the trigeminal nerve is crucial to successfully perform microvascular decompression surgery (MVD) in patients with trigeminal neuralgia. OBJECTIVE: To determine advantages and disadvantages using a 3-dimensional (3D) exoscope for MVD surgery. METHODS: A 4K 3D exoscope (ORBEYE) was used by a single surgical team for MVD in a retrospective case series of 8 patients with trigeminal neuralgia in a tertiary center. Clinical and surgical data were collected, and advantages/disadvantages of using the exoscope for MVD were recorded after each surgery. Descriptive statistics were used to summarize the data. RESULTS: Adequate MVD of the trigeminal nerve root was possible in all patients by exclusively using the exoscope. It offered bright visualization of the cerebellopontine angle and the root entry zone of the trigeminal nerve that was comparable with a binocular operating microscope. The greatest advantages of the exoscope included good optical quality, the pronounced depth of field of the image for all observers, and its superior surgeon ergonomics. Disadvantages were revealed with overexposure at deep surgical sites and the lack of endoscope integration. In 6 patients, facial pain improved significantly after surgery (Barrow Neurological Institute pain intensity score I in 5 and III in 1 patient), whereas it did not in 2 patients (Barrow Neurological Institute score IV and V). No complications occurred. CONCLUSION: Utilization of a 3D exoscope for MVD is a safe and feasible procedure. Surgeons benefit from better ergonomics, excellent image quality, and an improved experience for observers.