Long-term telemetric intracranial pressure monitoring for diagnosis and therapy optimisation of idiopathic intracranial hypertension.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a disease which is difficult to diagnose and moreover difficult to treat. We developed a strategy for long-term telemonitoring of intracranial pressure (ICP), by incorporation of the NEUROVENT®-P-tel System, with the goal of improved diagnosis and consequent therapy of this disease. We highlight the results obtained through this approach. METHODS: Twenty patients with suspected IIH who were treated in our hospital from August 2014 to October 2020 (16 females, 4 males, median age 36,6 years), were assigned to one of two ICP monitoring settings, "Home-Telemonitoring" (n = 12) and "Home-Monitoring" (n = 8). The ICP data were analysed and used conjointly with the accompanying clinical picture for establishment of IIH diagnosis, and telemonitoring was resumed for therapy optimisation of confirmed cases. RESULTS: The diagnosis of IIH was confirmed in 18 of the 20 patients. Various surgical/interventional treatments were applied to the confirmed cases, including ventriculoperitoneal (VP) shunting (n = 15), stenting of the transvers venous sinus (n = 1), endoscopic third ventriculostomy (ETV) (n = 1), and ETV in combination with endoscopic laser-based coagulation of the choroid Plexus (n = 1). Optimal adjustment of the implanted shunt valves was achieved with an average valve opening pressure of 6,3 ± 2,17 cm H2O for differential valves, and of 29,8 ± 3,94 cm H2O for gravitational valves. The Home-Telemonitoring setting reduced consequent outpatient visits, compared to the Home-Monitoring setting, with an average of 3,1 visits and 4,3 visits, respectively. No complications were associated with the surgical implantation of the P-tel catheter. CONCLUSION: This study offers insight into the use of long-term ICP monitoring for management of IIH patients in combination with dual-valve VP shunts. The use of NEUROVENT® P-tel system and potentially other similar fully implantable ICP-monitoring devices, albeit invasive, may be justified in this complex disease. The data suggest recommending an initial adjustment of dual-valve VP-shunts of 30 and 6 cm H2O, for gravitational and differential valves, respectively. Further research is warranted to explore potential integration of this concept in IIH management guidelines.

Endoscopic-Assisted Burr Hole Reservoir and Ventricle Catheter Placement.

BACKGROUND: Accurate positioning of a ventricle catheter is of utmost importance. Various techniques to ensure optimal positioning have been described. Commonly, after catheter placement, additional manipulation is necessary to connect a burr hole reservoir or shunt components. This manipulation can lead to accidental catheter dislocation and should be avoided. Here, we present a new technique that allows direct endoscopic insertion of a burr hole reservoir with an already mounted ventricle catheter. METHODS: Before insertion, the ventricle catheter was slit at the tip, shortened to the correct length, and connected to the special burr hole reservoir. An intracatheter endoscope was then advanced through the reservoir and the connected catheter. This assemblage allowed using the endoscope as a stylet for shielded ventricular puncture. To confirm correct placement of the ventricle catheter, the endoscope was protruded a few millimeters beyond the catheter tip for inspection. RESULTS: The new technique was applied in 12 procedures. The modified burr hole reservoir was inserted for first-time ventriculoperitoneal shunting (n = 1), cerebrospinal fluid withdrawals and drug administration (n = 2), or different stenting procedures (n = 9). Optimal positioning of the catheter was achieved in 11 of 12 cases. No subcutaneous cerebrospinal fluid collection or fluid leakage through the wound occurred. No parenchymal damage or bleeding appeared. CONCLUSIONS: The use of the intracatheter endoscope combined with the modified burr hole reservoir provides a sufficient technique for accurate and safe placement. Connecting the ventricle catheter to the reservoir before the insertion reduces later manipulation and accidental dislocation of the catheter.

PROSAIKA: a prospective multicenter registry with the first programmable gravitational device for hydrocephalus shunting.

OBJECTIVE: Cerebrospinal fluid (CSF) overdrainage is a major problem in shunt therapy for hydrocephalus. The adjustable gravitational valve proSA allows for the first time a targeted compensation for overdrainage in the upright position without interfering with the differential pressure valve. To evaluate benefit, safety and reliability, the multicenter prospective registry PROSAIKA was conducted in 10 German neurosurgical centers. METHODS: Between March 2009 and July 2010, 120 hydrocephalic patients undergoing first time shunt implantation or shunt revision using proSA entered the study. 93 patients completed the 12 months follow-up. RESULTS: Hydrocephalus symptoms were improved in 86%, unchanged in 9% and deteriorated in 3%. In 51%, the proSA opening pressure was readjusted one or several times to treat suspected suboptimal shunt function, this resulted in clinical improvement in 55%, no change in 25%, and deterioration in 20% of these patients. The 1 year censored proSA shunt survival rate was 89%. Device related shunt failure was seen in two cases. CONCLUSIONS: This is the first clinical report on the implantation of the adjustable gravitational valve proSA with a follow-up of 12 months in a substantial number of patients. Irrespective of different hydrocephalus etiologies and indications for shunt surgery, the overall results after 12 months were very satisfying. The high frequency of valve readjustments underlines the fact that preoperative selection of the appropriate valve opening pressure is difficult. The low number of revisions and complications compared to other valves proves that proSA implantation adds no further risk; this valve is reliable, helpful and safe.

Mononostril endoscopic transsphenoidal approach to sellar and peri-sellar lesions: Personal experience and literature review.

OBJECTIVE: The endonasal endoscopic approach to skull base is still under investigation. The main goal is the minimal invasive approach to pathologies with a better rate of resection without retraction of the brain tissue. Here, the authors report their technique of transnasal endoscopic neurosurgery using a mononostril approach and its development. METHODS: The supplementary video demonstrates the different steps of the mononostril approach and resection of a pituitary adenoma. All video-recorded procedures that were carried out between 2000 and 2013 using this technique were analysed. The patients were followed prospectively. RESULTS: Visualization and handling were good in 246/251 (98%). In three cases, we had to switch to microscopy because of severe bleeding of the cavernous sinus. On follow-up, magnetic resonance imaging revealed radical tumour resection in 92% of all cases when intended. There was no mortality, and the low complication rate was remarkable. CONCLUSION: Our mononostril approach of transnasal transsphenoidal surgery shows better results compared with previously published reports in regards to radicality, low cerebrospinal fluid leaks and morbidity. The very low rate of nasal complains is particularly remarkable.

Overcoming CSF overdrainage with the adjustable gravitational valve proSA.

BACKGROUND: Despite progress in shunt valve technology, CSF overdrainage is still one of the most frequent complications in shunt-treated hydrocephalus. Particularly with regard to young and adolescent patients, treatment of manifest overdrainage is complicated by several hardly influenceable factors such as increasing height and mobility. Therefore, the aim of this study was to evaluate the therapeutic efficiency of the new adjustable gravitational valve, proSA. METHODS: Sixty-four shunt-treated young hydrocephalus patients aged 1.8-41.4 years (15.5 ± 10.5 years) suffering from clinical and/or radiological overdrainage underwent shunt revision surgery with the implantation of the new proSA valve. Clinical outcome after a 1-year follow-up period, pumping function of the valve chambers as well as the number of necessary postoperative valve adjustments were examined. RESULTS: Fifty-five patients completed the study as planned. All reported a significant improvement of their clinical condition; 91 % described a complete resolution in symptoms related to overdrainage. Preoperatively, more than 85 % of the valve chambers showed no or very slow refilling with CSF. After a year of proSA treatment, more than 90 % exhibited a normal valve chamber function. During the follow-up period, a total of 136 valve adjustments were necessary. None of the proSA valves had to be surgically revised. CONCLUSIONS: The postoperative adjustability of the opening pressure level is the advantage of the new gravitational valve. The good clinical outcome is attributed to the new valve technology. The proSA appears to be a promising shunt valve to overcome overdrainage in adolescent and adult hydrocephalus patients.

Electromagnetic-guided neuronavigation for safe placement of intraventricular catheters in pediatric neurosurgery.

OBJECT: Ventricular catheter shunt malfunction is the most common reason for shunt revision. Optimal ventricular catheter placement can be exceedingly difficult in patients with small ventricles or abnormal ventricular anatomy. Particularly in children and in premature infants with small head size, satisfactory positioning of the ventricular catheter can be a challenge. Navigation with electromagnetic tracking technology is an attractive and innovative therapeutic option. In this study, the authors demonstrate the advantages of using this technology for shunt placement in children. METHODS: Twenty-six children ranging in age from 4 days to 14 years (mean 3.8 years) with hydrocephalus and difficult ventricular anatomy or slit ventricles underwent electromagnetic-guided neuronavigated intraventricular catheter placement in a total of 29 procedures. RESULTS: The single-coil technology allows one to use flexible instruments, in this case the ventricular catheter stylet, to be tracked at the tip. Head movement during the operative procedure is possible without loss of navigation precision. The intraoperative catheter placement documented by screenshots correlated exactly with the position on the postoperative CT scan. There was no need for repeated ventricular punctures. There were no operative complications. Postoperatively, all children had accurate shunt placement. The overall shunt failure rate in our group was 15%, including 3 shunt infections (after 1 month, 5 months, and 10 months) requiring operative revision and 1 distal shunt failure. There were no proximal shunt malfunctions during follow-up (mean 23.5 months). CONCLUSIONS: The electromagnetic-guided neuronavigation system enables safe and optimal catheter placement, especially in children and premature infants, alleviating the need for repeated cannulation attempts for ventricular puncture. In contrast to stereotactic techniques and conventional neuronavigation, there is no need for sharp head fixation using a Mayfield clamp. This technique may present the possibility of reducing proximal shunt failure rates and costs for hydrocephalus treatment in this age cohort.

First clinical results with a new telemetric intracranial pressure-monitoring system.

BACKGROUND: The knowledge of intracranial pressure (ICP) is the basis of an appropriate neurosurgical treatment. Because clinical, fundoscopic, or radiological data alone are often elusive, a pre- or postoperative long-term monitoring of the ICP itself is desirable. OBJECTIVE: We describe the first clinical experiences with a new telemetric ICP-monitoring device. METHODS: The transducer of this telemetric intraparenchymal pressure probe is placed under the galea over the calvaria. ICP can be monitored via a special telemetric reader, placed over the intact skin, and the ICP values are stored in a small portable computer. The system does not require an intensive care environment and can be used in any ward or even at home. The system was successfully applied in 10 patients (age, 3-56 years) in whom raised ICP due to hydrocephalus, shunt dysfunction, endoscopic third ventriculostomy failure, craniostenosis, or pseudotumor cerebri was suspected. RESULTS: Continuous telemetric monitoring of ICP was performed for 2 to 24 weeks. In 7 patients, increased ICP values could be excluded, and further surgical maneuvers were avoided. In 3 patients, repeated plateaus or continuously raised ICP indicated surgery resulting in a normalization of ICP. CONCLUSION: This new telemetric system was safe and effective for ICP measurement over a long period, including home monitoring. For the patients, it was easy to handle, and reliable data could be recorded over many weeks. Based on this preliminary experience, the authors consider the new system extremely advantageous in surgical decision making in particularly difficult cases of suspected abnormalities of ICP.

Safety and efficacy of microporous polysaccharide hemospheres in neurosurgery.

BACKGROUND: Effective hemostasis is mandatory for brain tumor surgery. Microporous polysaccharide hemosphere (MPH) powder, a white powder compounded from potato starch, was recently introduced for surgical and emergency application. OBJECTIVE: To evaluate the safety and efficacy of MPHs in brain tumor surgery. METHODS: Thirty-three patients (mean age, 58 years; range, 22-84 years) underwent microsurgical brain tumor resection. Final hemostasis was performed by topical application of MPHs, video recorded, and subsequently analyzed. Blood samples were taken before surgery, before application of hemospheres, and postoperatively. Volume measurements of the tumor, resection cavity, and postoperative hematoma were done on magnetic resonance imaging and computed tomography scans. Clinical examinations focused on neurological outcome, complications, and allergic reactions. RESULTS: Effective hemostasis was achieved by exclusive use of MPHs in 32 patients. In 1 patient, a single arterial bleeding underwent additional bipolar electrocauterization. Mean operative time was 156.8 minutes (range, 60-235 minutes). Hemostasis with MPHs required 57 seconds (mean; range, 8-202 seconds). Subjective neurosurgeons' ranking of the hemostasis effect indicated excellent satisfaction. For the first 3 months, there was no hemospheres-related postoperative neurological worsening, no signs of allergic reaction, and no embolic complications. Early postoperative and 3-month follow-up magnetic resonance imaging and computed tomography scans excluded any expansive bleeding complication. As early as postoperative day 1, MPHs were no longer detected. There was no tumor mimicking contrast enhancement. CONCLUSION: In neurosurgery, MPHs allow fast and effective minimally invasive hemostasis. In this small case series, no adverse reactions were found.

Waterjet dissection of peripheral nerves: an experimental study of the sciatic nerve of rats.

BACKGROUND: Although waterjet dissection has been well evaluated in intracranial pathologies, little is known of its qualities in peripheral nerve surgery. Theoretically, the precise dissection qualities could support the separation of nerves from adjacent tissues and improve the preservation of nerve integrity in peripheral nerve surgery. OBJECTIVE: To evaluate the potential of the new waterjet dissector in peripheral nerve surgery. METHODS: Waterjet dissection with pressures of 20 to 80 bar was applied on the sciatic nerves of 101 rats. The effect of waterjet dissection on the sciatic nerve was evaluated by clinical tests, neurophysiological examinations, and histopathological studies up to 12 weeks after surgery. RESULTS: With waterjet pressures up to 30 bar, the sciatic nerve was preserved in its integrity in all cases. Functional damaging was observed at pressures of 40 bar and higher. However, all but 1 rat in the 80 bar subgroup showed complete functional regeneration at 12 weeks after surgery. Histopathologically, small water bubbles were observed around the nerves. At 40 bar and higher, the sciatic nerves showed signs of direct nerve injury. However, all these animals showed nerve regeneration after 12 weeks, as demonstrated by histological studies. CONCLUSION: Sciatic nerves were preserved functionally and morphologically at pressures up to 30 bar. Between 40 and 80 bar, reliable functional and morphological nerve regeneration occurred. Waterjet pressures up to 30 bar might be applied safely under clinical conditions. This technique might be well suited to separate intact peripheral nerves from adjacent tumor or scar tissue. Further studies will have to show the clinical relevance of these dissection qualities.

Treatment of recurrent trigeminal neuralgia due to Teflon granuloma.

Recurrent trigeminal neuralgia after microvascular decompression (MVD) may be due to insufficient decompression, dislocation of the implant to pad the neurovascular contact, or the development of granuloma. Here, we report on our experience with Teflon granuloma including its treatment and histopathological examination. In a series of 200 patients with trigeminal neuralgia MVD was performed with Teflon felt according to Jannetta's technique. In three patients with recurrent facial pain Teflon granuloma was found to be the cause for recurrence. In each instance, the granuloma was removed for histopathological examination. Mean age at the first procedure was 62.3 years and at the second procedure 66.3 years. Recurrence of pain occurred between 1 and 8.5 years after the first procedure. MRI scans demonstrated local gadolineum enhancement in the cerebellopontine angle, and CT scans showed local calcification. Intraoperatively dense fibrous tissue was found at the site of the Teflon granuloma. Histopathological examination revealed foreign body granuloma with multinuclear giant cells, collagen-rich hyalinized scar tissue, focal hemosiderin depositions, and microcalcifications. The Teflon granuloma was completely removed, and a new Teflon felt was used for re-decompression. Patients were free of pain after the second procedure at a mean of 40.3 months of follow-up. Teflon granuloma is a rare cause for recurrent facial pain after MVD. Small bleeding into the Teflon felt at surgery might trigger its development. A feasible treatment option is surgical re-exploration, nerve preserving removal of the granuloma, and repeat MVD.

Solitary fibrous tumor of the foramen of Monro.

Solitary fibrous tumors have been described rarely in the central nervous system and only exceptionally within the ventricular system. This benign entity shows histoimmunochemically strong positivity for vimentin and calretinin. Little is known about the pathophysiological aspects. The authors report on a 75-year-old woman who presented with clinical signs of occlusive hydrocephalus including cognitive deficits, urine incontinence and gait disturbance. Imaging studies demonstrated a tumor at the foramen of Monro which was thought to be a colloid cyst and she underwent CSF shunting. After recurrent episodes of shunt dysfunction the tumor was removed via a transventricular approach guided by endoscopic ventriculoscopy. The histopathological examination revealed a solitary fibrous tumor. This is the first report on a solitary fibrous tumor located at the foramen of Monro in an elderly patient. Surgical removal has been considered to be the best therapeutic strategy in treating this rare entity with no need of postoperative adjuvant therapy. Further imaging and histological studies are needed to improve understanding of the pathophysiological aspects behind it.

Fracture of the occipital condyle caused by minor trauma in child.

We report a case of fractured occipital condyle caused by minor trauma accompanied by light pain on palpation at the lateral cervical trigonum. A 15-year-old boy complained of nuchal pain, particularly pain on palpation at the left lateral cervical trigonum in the absence of neurologic deficits after head deceleration trauma. Computed tomography demonstrated a unilateral nonluxated fracture of the occipital condyle. Owing to consequent immobilization by means of cervical orthosis, pain disappeared after the first 48 hours. Follow-up examination 4 weeks later showed no neurologic deficits. The boy had no severe impairment of movements at the cervical spine.