Part II: Blood Transfusion and Donor Exposure in the Surgical Management of Trigonocephaly Patients: A Protocol From Alder Hey Craniofacial Unit.

Trigonocephaly is a craniofacial malformation caused by premature fusion of the metopic suture. Surgical correction frequently results in the need for blood transfusion. Transfusion complications include transfusion-transmitted infections (TTIs), immune-mediated reactions, and volume overload. Donor exposure (DE) describes the number of blood products from unique donors with increasing DE equating to an increased risk of TTI. We evaluate data on 204 trigonocephaly patients covering 20 years of practice with respect to blood transfusions and DE. This represents the largest series from a single unit to date. A protocol based on our experiences has been devised that summarizes the key interventions we recommend to minimize blood transfusions and DE in craniofacial surgery. Patients operated on between 2000 and 2020 were included. DE and a range of values were calculated including estimated red cell loss (ERCL) and estimated red cell volume transfused (ERCVT). Groups were established by relevant interventions and compared using the Mann-Whitney U test. Mean DE fell from 1.46 at baseline to 0.85 ( P <0.05). Median allogenic transfusion volume fell from 350 mL at baseline to 250 mL ( P <0.05). Median ERCL fell from 15.05 mL/kg at baseline to 12.39 mL/kg and median ERCVT fell from 20.85 to 15.98 mL/kg. Changes in ERCL and ERCVT did not reach statistical significance. DE can be minimized with the introduction of key interventions such as a restrictive transfusion policy, preoperative iron, cell saver, tranexamic acid, and use of a matchstick burr for osteotomies.

Non-pharmacological treatment options of drug-resistant epilepsy in subcortical band heterotopia: systematic review and illustrative case.

OBJECTIVE: Subcortical band heterotopia is a rare X-linked neuronal migration disorder primarily in females often associated with drug-resistant epilepsy. The aim of this study is to review the literature for non-pharmacological treatment options of drug-resistant epilepsy in subcortical band heterotopia. MATERIAL AND METHODS: In accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we performed a systematic review. Entering the keywords "double cortex," "subcortical band heterotopia," and "subcortical laminar heterotopia," we searched Scopus and PubMed databases. We paid particular attention to type of invasive and non-invasive treatment, radiological presentation, and outcome. We also describe a related case report, managed at Alder Hey Children's Hospital, Liverpool. RESULTS: The systematic literature review yielded 25 patients with subcortical band heterotopia and drug-resistant epilepsy who underwent non-pharmacological treatment. Including our patient, 26 patients were reported. The patients' mean age at seizure onset was 6.5 years (range 0.2-23) with a female sex predilection (5.25:1). The patients' mean age at invasive or non-invasive treatment was 21.5 years (range 6.5-51). The 26 patients underwent 29 non-pharmacological treatments. Ten patients underwent corpus callosotomy; 8 patients had a formal temporal lobectomy. Three patients had focal cortical resection. Two patients respectively had multiple subpial transections, insertion of a vagal nerve stimulator, or deep brain stimulation of the bilateral anterior nuclei of the thalamus. One patient underwent responsive focal neurostimulation. Another patient had transcutaneous stimulation of the vagal nerve. Sixteen patients reported a reduction or the disappearance of the seizures; 1 patient had no improvement. The outcome of 2 patients was classified class I, of 1 patient class II, of 1 patient class III, and of 5 patients class IV according to the Engel Epilepsy Surgery Outcome Scale. CONCLUSION: Mainly corpus callosotomy and formal temporal lobectomy have been performed as non-pharmacological treatment with few cases published overall. Several other invasive procedures and one non-invasive technique are based on case reports. The small number of reported cases prevents drawing a firm conclusion as to which non-pharmacological treatment is the best treatment option for refractive epilepsy in patients with subcortical band heterotopia.

Secure windows for child safety: a retrospective study of window falls in children, aiming to raise prevention awareness.

PURPOSE: The aim of the study is to enhance understanding, raise awareness and inform prevention programmes regarding potential factors that lead to severe paediatric injuries caused by unintentional falls from windows. METHODS: This is a retrospective review from a major Trauma Centre, covering the majority of North West England and North Wales and included children under the age of 16 that had sustained falls from windows and were hospitalised between April 2015 and June 2020. RESULTS: Overall, 825 patients' records have been reviewed, 39% of which exhibited neurosurgical injuries (322 admissions). The most common cause of injury was falls (42%), out of which 19% was identified as falls from windows which was eventually the core focus of this review (25 patients). The records showed that 72% of the falls were not witnessed by another individual, suggesting that children were being left unattended. Average GCS recorded at presentation was 11.2 and 56% of cases were identified as severe major traumas. With a mean stay of 2.2 days in ICU, 1.6 days in HDU and 6 days in the neurosurgical clinic, average treatment costs per patient were £4,493, £651 and £4,156 respectively. Finally, 52% of patients were identified to require long-term physiotherapy/occupational therapy due to permanent disabilities, 20% long-term antiepileptic treatment for seizures and 44% long-term psychological services input. CONCLUSION: This study presents our experience at a major tertiary trauma centre in the UK over a 5-year period, from a paediatric neurosurgical injuries perspective due to fall from windows. We aim to raise awareness and highlight the importance of establishing prevention programmes which would hopefully decrease the incidence of paediatric window falls.

Intracranial Empyemas in the COVID-19 Era: A New Phenomenon? A Paediatric Case Series and Review of the Literature.

INTRODUCTION: We present the largest series of paediatric intracranial empyemas occurring after COVID-19 infection to date, and discuss the potential implications of the pandemic on this neurosurgical pathology. METHODS: Patients admitted to our centre between January 2016 and December 2021 with a confirmed radiological diagnosis of intracranial empyema were retrospectively reviewed, excluding non-otorhinological source cases. Patients were grouped according to onset before or after onset of the COVID-19 pandemic and COVID-19 status. A literature review of all post-COVID-19 intracranial empyemas was performed. SPSS v27 was used for statistical analysis. RESULTS: Sixteen patients were diagnosed with intracranial empyema: n = 5 prior to 2020 and n = 11 after, resulting in an average annual incidence of 0.3% prior to onset of the pandemic and 1.2% thereafter. Of those diagnosed since the pandemic, 4 (25%) were confirmed to have COVID-19 on recent PCR test. Time from COVID-19 infection until empyema diagnosis ranged from 15 days to 8 weeks. Mean age for post-COVID-19 cases was 8.5 years (range: 7-10 years) compared to 11 years in non-COVID cases (range: 3-14 years). Streptococcus intermedius was grown in all cases of post-COVID-19 empyema, and 3 of 4 (75%) post-COVID-19 cases developed cerebral sinus thromboses, compared to 3 of 12 (25%) non-COVID-19 cases. All cases were discharged home with no residual deficit. CONCLUSION: Our post-COVID-19 intracranial empyema series demonstrates a greater proportion of cerebral sinus thromboses than non-COVID-19 cases, potentially reflecting the thrombogenic effects of COVID-19. Incidence of intracranial empyema at our centre has increased since the start of the pandemic, causes of which require further investigation and multicentre collaboration.

The Paediatric Vault Score (PVS)-A Novel Scoring Tool for Prioritisation of Surgical Management of Craniosynostosis Patients.

Craniosynostosis is the premature fusion of the skull sutures, resulting in abnormal skull shape and volume. Timely management is a priority in avoiding raised intracranial pressure which can result in blindness and neurodevelopmental delay. Due to the COVID-19 pandemic, theater access was reduced. A risk stratification scoring system was thus devised to score patients attending surgery and aid in prioritization according to surgical need. The authors present the Paediatric Vault Score (PVS), which can also be customized to each unit's individual protocols. Ten patients on the waiting list were randomly selected and their clinical information was summarized in uniform anonymized reports. Six craniofacial consultants were selected as assessors and given 1 week to independently rank the patients from 1 to 10. Each scorer's ranking was verified against the PVS template and concordance was analyzed using the Kendall tau correlation coefficient (KT). Three cycles of the scoring process were carried out. Improvements were made to the scoring tool following cycle 1. Cycle 1 revealed 2 clinicians to be concordant with the PVS system and 4 to be discordant. Cycle 2 revealed all 6 clinicians to be concordant, with a mean KT score of 0.61. The final cycle revealed all 6 clinicians to be concordant, with a mean KT score of 0.70. Four scorers increased their concordance once the scoring sheet was introduced. Kendall's correlation of concordance calculated the interrater reliability to be 0.81. The PVS is the first known vault scoring system to aid in risk stratification and waiting list prioritization.

Patient Tailored Surgery in Saethre-Chotzen Syndrome: Analysis of Reoperation for Intracranial Hypertension.

Saethre-Chotzen syndrome (SCS) is a syndromic craniosynostosis with pathogenic variants in the TWIST1 gene showing a broad phenotypic spectrum. Controversies exist in the literature regarding surgical management with single one-stage versus patient-tailored surgery and the related reoperation rate for intracranial hypertension of up to 42%. At our center, SCS patients are offered patient-tailored surgery with single-stage fronto-orbital advancement and remodeling or fronto-orbital advancement and remodeling and posterior distraction in an individually determined order. The authors' database identified 35 confirmed SCS patients between 1999 and 2022. Involved sutures in craniosynostosis were left unicoronal (22.9%), bicoronal (22.9%), sagittal (8.6%), bicoronal and sagittal (5.7%), right unicoronal (2.9%), bicoronal and metopic (2.9%), bicoronal, sagittal and metopic (2.9%), and bilateral lambdoid (2.9%). There was pansynostosis in 8.6% and no craniosynostosis in 14.3% of the patients. Twenty-six patients, 10 females, and 16 males were operated on. Mean age at the first surgery was 1.70 years, and 3.86 years at the second surgery. Eleven of 26 patients had invasive intracranial pressure monitoring. Three patients presented with papilledema before the first surgery and 4 afterward. Four of the 26 operated patients were operated initially elsewhere. The other 22 patients were initially referred to our unit and underwent patient-tailored surgery. Nine of these patients (41%) had a second surgery, and 3 (14%) of them were because of raised intracranial pressure. Seven (27%) of all operated patients had a complication. Median follow-up was 13.98 years (range, 1.85-18.08). Patient-tailored surgery in a specialized center and long-term follow-up allow for a low reoperation rate for intracranial hypertension.

Persisting embryonal infundibular recess in a case of TITF-1 gene mutation.

The thyroid transcription factor 1 (TITF-1) gene plays an important role in the development of the ventral forebrain, thyroid and lungs. Mutations of this gene are known to cause benign hereditary chorea (BHC) and can cause the full spectrum of abnormalities seen in the brain-thyroid-lung syndrome. Abnormalities of the ventral forebrain on imaging have been variably documented in the literature. Multiple previous reports describe a cystic pituitary mass, as well as duplication of the pituitary stalk and communication between an intrasellar cyst and the third ventricle. The initial MRI performed in our case was interpreted as an intrasellar cyst, but the high-resolution MRI performed later was able to resolve this as a persisting embryonal infundibular recess (PEIR), rather than the cystic pituitary mass which has previously been described. This case illustrates the role of the TITF-1 gene in the development of the pituitary and hypothalamus.

Part 1: Surgical Correction in 231 Trigonocephaly Patients - The Alder Hey Experience.

ABSTRACT: Isolated metopic synostosis presents with a range of severity, from a palpable ridge as the sole presenting feature to a constellation of features resulting in trigonocephaly. At our unit, patients on the moderate to severe end of the phenotypic spectrum of trigonocephaly are offered fronto-orbital advancement and remodeling. The authors present our series of trigonocephaly patients who have undergone surgical correction. From January 2000 to January 2020, the authors operated on 231 patients with trigonocephaly. The average age at surgery was 18 months, with an average follow-up of 77.4 months. Seventy-nine percent of patients had no comorbidity. Ten percent of patients sustained a dural tear with no long-term consequences. The total early complication rate was 12.1%. The most common early complications were wound infection and wound dehiscence at 7.4% and 3.9% respectively. The total reoperation rate was 6.5%. The introduction of infection prevention and control measures over the 2 decades at our unit reduced the reoperation rate to 1.1%. The most common late complication was temporal recession in 20.8% of patients, none of whom required aesthetic correction. The recurrence rate of a metopic ridge was 2.3% with no patients requiring further surgery. None of our patients required calvarial remodeling for raised intracranial pressure after the primary fronto-orbital advancement and remodeling. There were no life-threatening complications or mortalities in our cohort. The authors present recommendations which include an infection control care bundle, cessation of surgical drains, and practice adjustments to reduce risks of infection and risk of requiring further calvarial remodelling for raised intracranial pressure.

Isolated Frontosphenoidal Craniosynostosis: The Alder Hey Experience and a Novel Algorithm to Aid Diagnosis.

ABSTRACT: Unilateral synostotic frontal plagiocephaly is most commonly due to a premature fusion of the frontoparietal suture. However, the coronal ring comprises of major and minor sutures and these sutures in isolation or in combination can result in similar clinical presentations which can make diagnosis challenging and result in a delay in referral to a craniofacial surgeon for timely management. Isolated frontosphenoidal craniosynostosis is a rare clinical entity with only 49 cases reported in the English literature to date. The authors present our series of 4 patients to add to this cohort of patients and describe key characteristics to distinguish frontoparietal from isolated frontosphenoidal synostosis and introduce a means of differentiating these 2 diagnoses from posterior deformational plagiocephaly and unilateral lambdoid synostosis. All previous case reports have been diagnosed after radiological imaging but the authors have devised a novel algorithm to aid the clinician in diagnosis of craniosynostosis before any radiological imaging.

Kosaki overgrowth syndrome: A novel pathogenic variant in PDGFRB and expansion of the phenotype including cerebrovascular complications.

Heterozygous activating variants in platelet-derived growth factor, beta (PDGFRB) are associated with phenotypes including Kosaki overgrowth syndrome (KOGS), Penttinen syndrome and infantile myofibromatosis (IM). Here, we present three new cases of KOGS, including a patient with a novel de novo variant c.1477A > T p.(Ser493Cys), and the oldest known individual age 53 years. The KOGS phenotype includes characteristic facial features, tall stature, scoliosis, hyperelastic thin skin, lipodystrophy, variable intellectual and neurological deterioration, and abnormalities on brain imaging. Long-term outcome is unknown. Our cases confirm the phenotypic spectrum includes progressive flexion contractures, camptodactyly, widely spaced teeth, and constriction rings. We also propose novel occasional features including craniosynostosis, ocular pterygia, anterior chamber cleavage syndrome, early osteoporosis, increased pigmentation, recurrent haematomas, predisposition to cellulitis, nail dystrophy, carpal tunnel syndrome, recurrent hypoglycaemia in infancy, joint dislocation, and splenomegaly. Importantly, we report fusiform aneurysm of the basilar artery in two patients. Complications include thrombosis and stroke in the oldest reported patient and fatal rupture at the age of 21 in the patient with the novel variant. We conclude that cerebrovascular complications are part of the phenotypic spectrum of KOGS and KOGS-like disorders and suggest vascular imaging is indicated in these patients.

Management of paediatric hydrocephalous with Miethke fixed pressure gravitational valves. The Alder Hey Children's Hospital experience.

OBJECTIVE: The management of paediatric hydrocephalous remains challenging with the complication and revision rates being consistent in the literature. We hypothesise that the use of a fixed pressure gravitational valve for all de novo shunt insertions decreases the rate of functional revisions and that by implementing the routine use of gravitational valves in children, we would see a reduction in over-drainage and slit ventricle syndrome. METHODS: Retrospective data collection in a single centre, between February 2010 and August 2018. All patients undergoing fixed pressure gravitational Miethke valve insertion were included. We collected data on patients' demographics, reason for shunt insertion, type of valve and time to and reason for first revision. Data analysis was done with SPSS. RESULTS: A total of 235 patients were included in our study (124 males, 111 females), aged from 0 to 18.6 years (median 0.28). A total of 99 shunt revisions were documented, 30 of which secondary to ventricular catheter malfunction and 28 secondary to infection. The overall mechanical valve survival rates were 88.5%, 86.4% and 85.5% at 1, 2 and 5 years, respectively. Shunt revision due to over-drainage was documented in only 3 cases (1.3%). CONCLUSION: Our results are in agreement with existing literature regarding shunt failures secondary to all extrinsic factors to the valve (infection and mechanical failure). We have shown that the use of a Miethke fixed pressure valve for all de novo shunt insertions in paediatric hydrocephalus decreases the need for functional revisions with valve survival rates being superior to the ones described for other types.

Early Extended Midline Strip Craniectomy for Sagittal Synostosis.

BACKGROUND: Isolated sagittal synostosis is the most common form of nonsyndromic craniosynostosis. The surgical management of this condition ranges from strip craniectomy to total cranial vault remodeling. In our unit, passive correction of sagittal synostosis utilizing open extended midline strip craniectomy with bilateral micro-barrel staving is performed before 22 weeks corrected age. The aim of this prospective study is to identify the effectiveness and morbidity associated with this technique. PATIENTS AND METHODS: Nonsyndromic patients who underwent OMEC at a tertiaryreferral-center (Alder Hey Children's Hospital, Liverpool, UK) over a 3-year period (2014-2016) were included. In particular, we looked at pre- and postoperative cranial index (CI), as well as other secondary outcomes such as rates of transfusion and reoperation. RESULTS: A total of 44 patients (12 female, 32 male) met the inclusion criteria. Median age at operation was 132 (range 99-171) days. Median operative time was 117 (range 89-171) minutes. Twenty-four patients underwent a blood transfusion. Median pre-op CI was 66 (range 61-74.7)%. The first post-op CI, taken a median of 56 (range 12-107) days postoperatively, was 78 (range 73-87)%. No patients required reoperation. There were no perioperative deaths. CONCLUSION: Early open extended midline strip craniectomy with bilateral micro-barrel staving for correction of isolated nonsyndromic sagittal synostosis is a safe and effective technique, associated with minimal morbidity, producing sustained satisfactory head shape morphology on short to medium-term follow-up.

Academic neurosurgery in the UK: present and future directions.

Academic neurosurgery encompasses basic science and clinical research efforts to better understand and treat diseases of relevance to neurosurgical practice, with the overall aim of improving treatment and outcome for patients. In this article, we provide an overview of the current and future directions of British academic neurosurgery. Training pathways are considered together with personal accounts of experiences of structured integrated clinical academic training and unstructured academic training. Life as an academic consultant is also described. Funding is explored, for the specialty as a whole and at the individual level. UK academic neurosurgical organisations are highlighted. Finally, the UK's international standing is considered.

Neurosurgeon or spinal surgeon - who should treat cauda equina syndrome?

Suspected cauda equina syndrome (CES) requires urgent evaluation, investigation and treatment. Timing of cauda equina decompression is crucial, and delays in its management, leading to significant irreversible disability can be devastating for patient and surgeon alike. The standard of care in CES therefore needs to be clear and unambiguous. Todd and Dickson have written an excellent paper summarising the condition, and have outlined what they feel is the standard of care. We would ask the authors to clarify an important point.

Management of granulomatous cerebral aspergillosis in immunocompetent adult patients: a review.

Cerebral aspergillosis, is an infrequent, opportunistic infection of the central nervous system that accounts for 5-10% of all intracranial fungal pathology. It is uncommon in immunocompetent patients and has a significant disease burden, with high morbidity and mortality, even with appropriate treatment. Basic principles of abscess management should be employed, including aspiration and targeted anti-fungal therapy for 12-18 months. However, reported outcomes with a purely minimally invasive approach are poor and there should be a low threshold for surgical excision, especially in resource poor settings and in patients with deteriorating neurology harbouring sizeable masses. Evidence favouring gross total excision over subtotal resection is lacking, however. It is notable that these recommendations are largely based on retrospective case series and isolated case reports. There is a need therefore for international collaboration to evaluate management strategies for immunocompetent patients with cerebral aspergillosis.

The role of early intra-operative MRI in partial resection of optic pathway/hypothalamic gliomas in children.

INTRODUCTION: Optic pathway/hypothalamic gliomas (OPHGs) are generally benign but situated in an exquisitely sensitive brain region. They follow an unpredictable course and are usually impossible to resect completely. We present a case series of 10 patients who underwent surgery for OPHGs with the aid of intra-operative MRI (ioMRI). The impact of ioMRI on OPHG resection is presented, and a role for ioMRI in partial resection is discussed. METHODS: Ten patients with OPHGs managed surgically utilising ioMRI at Alder Hey Children's Hospital between 2010 and 2013 were retrospectively identified. Demographic and relevant clinical data were obtained. MRI was used to estimate tumour volume pre-operatively and post-resection. If ioMRI demonstrated that further resection was possible, second-look surgery, at the discretion of the operating surgeon, was performed, followed by post-operative imaging to establish the final status of resection. Tumour volume was estimated for each MR image using the MRIcron software package. RESULTS: Control of tumour progression was achieved in all patients. Seven patients had, on table, second-look surgery with significant further tumour resection following ioMRI without any surgically related mortality or morbidity. The median additional quantity of tumour removed following second-look surgery, as a percentage of the initial total volume, was 27.79% (range 11.2-59.2%). The final tumour volume remaining with second-look surgery was 23.96 vs. 33.21% without (p = 0.1). CONCLUSIONS: OPHGs are technically difficult to resect due to their eloquent location, making them suitable for debulking resection only. IoMRI allows surgical goals to be reassessed intra-operatively following primary resection. Second-look surgery can be performed if possible and necessary and allows significant quantities of extra tumour to be resected safely. Although the clinical significance of additional tumour resection is not yet clear, we suggest that ioMRI is a safe and useful additional tool, to be combined with advanced neuronavigation techniques for partial tumour resection.

Linear accelerator radiosurgery for vestibular schwannomas: Results of medium-term follow-up.

BACKGROUND: To examine tumour control, via volume changes, and the complications of linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) treatment of vestibular schwannomas (VSs) on medium-term follow-up. METHODS: Between September 2003 and November 2009 fifty consecutive patients with VSs treated with SRS using a marginal dose of 12.5 Gy utilizing a LINAC equipped with a micro-multileaf collimator were identified. Evaluation included serial magnetic resonance imaging (MRI), and neurological and hearing examinations. RESULTS: The median tumour volume at treatment was 2.4 (range: 0.24-10.59) cm3. The intracranial diameter of the tumours ranged between 7.7 and 28.7 (median: 15.8) mm. Follow-up MRI was available for analysis on 49 patients. The median radiological follow-up period was 5.8 (range: 1.4-9.2) years. The median tumour volume at last follow-up was 1.1 (range: 0.03-5.3) cm3. VS decreased in size in 45 (90%) patients, with a median reduction in tumour volume of 1.46 (range: 0.06-9.29) cm3 or a median tumour size reduction of 59% of the baseline (range: 6-90%) in these patients. VS remained stable in 2 patients and increased in size in 2 patients. Only 1 patient (2%) required additional intervention (surgery). 15 patients had useful hearing pre-treatment; 10 post-treatment pure-tone audiograms of these patients were available. 5 (50%) patients still had useful hearing post treatment. Non-auditory adverse radiation effects included new (House-Brackmann grade II) or worsened facial nerve palsy (House-Brackmann grade II to grade V) in 2 (4%) patients and trigeminal sensory disturbance in 2 (4%) patients. CONCLUSIONS: At medium term, the vast majority of VSs treated with LINAC-based SRS exhibit tumour shrinkage. The slightly higher rate of facial nerve palsy compared with Gamma Knife surgery (GKS) results may be related to the learning curve. Other complications were similar to reported GKS results for VSs of comparable sizes.

Is the rate of re-operation after primary lumbar microdiscectomy affected by surgeon grade or intra-operative lavage of the disc space?

STUDY DESIGN. Retrospective audit of consecutive patients. OBJECTIve. To investigate the re-operation rate following elective primary lumbar microdiscectomy and to determine whether principal surgeon grade and/or disc space lavage is a factor in recurrence. SUMMARY OF BACKGROUND DATA. Recurrent herniation of disc material following lumbar microdiscecomy surgery is one of the commonest complications of the procedure. Any reduction in the number of revision microdiscectomies performed per year would have a significant impact on patients' lives and on the health service economy. We undertook this study to ascertain whether principal surgeon grade and/or disc space lavage has an impact in reducing the re-operation rate. METHODS. We undertook a retrospective audit of patients who underwent elective primary lumbar microdiscectomy, over a 3-year period (n = 971). RESULTS. The overall re-operation rate for primary elective microdiscectomy was 3.8%, consistent with the published literature. The relative risk of re-operation in patients primarily operated by registrar surgeons was 1.2 fold the risk in patients operated by consultants (95% CI: 0.62, 2.35) although not statistically significant (p = 0.568). The risk of re-operation in the 'non lavage' group was 2.15 times the risk in the 'lavage' group (95% CI: 0.63, 7.34), but it did not reach significance (p = 0.222). CONCLUSIONS. Principal surgeon grade and intervertebral disc lavage have not been found conclusively to be factors in the rate of recurrence. This information is useful to reassure patients that their outcome from such surgery is not dependent on the grade of surgeon performing the operation. There is a possible trend towards intervertebral disc lavage reducing the rate of recurrence.

Applications of the ultrasonic bone cutter in spinal surgery--our preliminary experience.

OBJECTIVE: To present our experience with the Misonix Ultrasonic Bone scalpel in spinal surgery, highlighting its potential applications and advantages. METHODS: Between March and December 2011, a total of 937 spinal cases were performed at a single centre. The Misonix Bone Scalpel (MBS) was used in 62 of these cases. Data were collected prospectively using the Spine Tango registry. Patient demographics, disease type, surgery performed and complications were all recorded along with pre- and post-operative core measures outcome index (COMI). RESULTS: The majority of cases were for spinal degenerative disorders, in particular, revision cases. The bone cutter was also used to achieve laminotomies for access to intradural tumours, corpectomies and a mixture of other pathologies. Of the 62 patients only 1 (1.6%) experienced a blood loss greater than 500 ml, and there was only 1 dural tear (1.6%) as a direct result of the MBS. Four illustrative cases are discussed. CONCLUSIONS: The MBS is a useful adjunct in spinal surgery with particular value in revision cases where scar tissue distorts the normal anatomy. There was a low complication rate with a trend to reduced blood loss. This was most apparent to the senior authors during cervical and thoracic corpectomies.

Review of the targeting accuracy of frameless and frame-based robot-assisted deep brain stimulation electrode implantation in pediatric patients using the Neurolocate module.

OBJECTIVE: The Neurolocate module is a 3D frameless patient registration module that is designed for use with the Neuromate stereotactic robot. Long-term electrical stimulation of the globus pallidus internus (GPi) and subthalamic nucleus (STN) via deep brain electrode implantation is particularly successful in a select group of movement disorders in pediatric patients. This study aimed to review the targeting accuracy of deep brain stimulation (DBS) electrode implantation in a single center, comparing standard frame-based techniques to the frameless Neurolocate module. METHODS: Twenty-four pediatric patients underwent implantation of bilateral DBS electrodes under general anesthesia during the period of August 2018-August 2022. All patients underwent robot-assisted stereotactic implantation of DBS electrodes using an intraoperative O-arm 3D scanner to confirm the final electrode position. These coordinates were compared with the planned entry and target, with attention to depth, radial, directional, and absolute errors, in addition to Euclidean distance (ED). The primary outcome evaluated the accuracy and safety of the Neurolocate frameless technology compared with standard frame-based techniques. RESULTS: Of the 24 bilateral DBS electrode implantations performed, 62.5% used Neurolocate technology: 87.5% were delivered to the GPi and the remaining 12.5% to the STN. The mean patient age was 11.0 (range 4-18) years and 70.8% were male. The median absolute errors in x-, y-, and z-axes were 0.35, 0.75, and 0.9 mm, respectively, using the Neurolocate module compared with 0.30, 0.95, and 1.1 mm using the standard frame-based technique. The median ED from the planned target to the actual electrode position with the Neurolocate module was 1.28 mm versus 1.69 mm using standard frame-based techniques. No major perioperative complications occurred. CONCLUSIONS: Stereotactic robot-assisted DBS implantation with the frameless Neurolocate module is safe for use in the pediatric population, showing good surgical accuracy and no inferiority to standard frame-based techniques. The Neurolocate module for robotic DBS surgery has the potential to improve surgical targeting accuracy, surgical time, patient comfort, and safety.