Use of machine learning to model surgical decision-making in lumbar spine surgery.

PURPOSE: The majority of lumbar spine surgery referrals do not proceed to surgery. Early identification of surgical candidates in the referral process could expedite their care, whilst allowing timelier implementation of non-operative strategies for those who are unlikely to require surgery. By identifying clinical and imaging features associated with progression to surgery in the literature, we aimed to develop a machine learning model able to mirror surgical decision-making and calculate the chance of surgery based on the identified features. MATERIAL AND METHODS: In total, 55 factors were identified to predict surgical progression. All patients presenting with a lumbar spine complaint between 2013 and 2019 at a single Australian Tertiary Hospital (n = 483) had their medical records reviewed and relevant data collected. An Artificial Neural Network (ANN) was constructed to predict surgical candidacy. The model was evaluated on its accuracy, discrimination, and calibration. RESULTS: Eight clinical and imaging predictive variables were included in the final model. The ANN was able to predict surgical progression with 92.1% accuracy. It also exhibited excellent discriminative ability (AUC = 0.90), with good fit of data (Calibration slope 0.938, Calibration intercept - 0.379, HLT > 0.05). CONCLUSION: Through use of machine learning techniques, we were able to model surgical decision-making with a high degree of accuracy. By demonstrating that the operating patterns of single centres can be modelled successfully, the potential for more targeted and tailored referrals becomes possible, reducing outpatient wait-list duration and increasing surgical conversion rates.

The use of radiolucent pedicle fixation in degenerative lumbar spine surgery.

Radiolucent pedicle screw fixation has become popularized in the field of oncological spine surgery owing to its ability to provide superior post-operative planning for adjuvant radiotherapy and radiological monitoring of tumour progression. We present the case of a 45-year-old female with degenerative spine pathology who underwent L4/5 and L5/S1 posterior lumbar interbody fusion with carbon fibre reinforced-polyetheretherketone pedicle screw fixation. The authors highlight the potential advantages of radiolucent pedicle fixation, which may translate into the degenerative spine surgery domain.

The use of radiolucent (carbon fibre-reinforced polymer) pedicle screw fixation for serial monitoring of clear cell meningioma: a case report.

Clear cell meningioma is an uncommon variant of meningioma associated with high rates of local recurrence and metastasis. However, monitoring for local recurrence may be complicated by metal-related artefacts generated by spinal instrumentation. We present a patient with recurrent lumbar atypical clear cell meningioma, which had been resected multiple times throughout her adolescence. Due to extensive bone and ligament resection, posterior stabilization of the lumbar spine with pedicle screws was required. To ensure clear postoperative visualization of the spinal cord for local recurrence, a carbon fibre/polyetheretherketone (CF/PEEK) pedicle screw and rod construct was used. CF/PEEK has non-inferior biomechanical and biocompatible properties to titanium, with a clear advantage of radiolucency to assist in detecting the local recurrence early and facilitating accurate radiotherapy planning.

The removal of cranial springs used in the treatment of scaphocephaly: A minimal access approach.

The treatment of non-syndromic scaphocephaly with spring-activated cranioplasty offers acceptable outcomes with the potential for reduced surgical morbidity when compared with cranial vault remodelling procedures. A disadvantage of this technique is the need for a second operative intervention to remove the implanted devices. There are many descriptions of the surgical technique for performing spring-activated cranioplasty available in the literature; however, little is documented regarding the procedures used for device removal. The published accounts of spring removal demonstrate a wide range of approaches, from the reopening and dissection of the entire previous surgical field, to attempts to limit the incisions and dissection. In this study we describe our technique for the minimally invasive removal of cranial springs used in the treatment of scaphocephaly. Our technique focuses on minimal soft tissue disruption and uses a Kirschner wire cutter to divide the spring at its mid-point so as to relieve any residual internal forces acting on the footplates.

Subclinical Burden of Coronary Artery Calcium in Patients With Coarctation of the Aorta.

Coronary computed tomography (CT) angiography is often performed in adults with coarctation of the aorta (CoA) for anatomic assessment. As this population ages, assessment of atherosclerotic cardiovascular disease burden is important. Thus, quantitative and qualitative coronary artery calcium (CAC) scores were assessed for patients with CoA ≥16 years of age, who were seen at a referral center. CoA patients had either coronary CT angiography or chest CT with interpretable coronary information performed for clinical indications (follow-up, preoperative, or for symptoms) from 2004 to 2017. Qualitative CAC was determined based on low-dose CT and lung cancer screening protocols. Quantitative CAC scores were compared with an age- and gender-matched control cohort of patients chosen from an emergency department database of patients who received coronary CT angiography for chest pain evaluation. Atherosclerotic cardiovascular disease 10-year predicted risk scores were calculated for both cohorts. Out of 131 patients with CoA (mean age 46.1 ± 15.3 years), 22 patients (17%) had multivessel atherosclerotic disease on qualitative assessment. In the subgroup of patients ≥40 years, those with CoA were more likely to have a quantitative CAC score ≥400 compared with those without CoA (14% vs 4%, p = 0.02). Median atherosclerotic cardiovascular disease risk score was 8% (interquartile range 2% to 12%) for CoA patients ≥40 years, and 5% (interquartile range 2% to 9%) for patient without CoA ≥40 years. In conclusion, we determined that CoA patients have subclinical atherosclerosis identifiable on CT in high rates when compared with patients without CoA. Atherosclerotic cardiovascular disease should be assessed in these patients for prevention and treatment.

How immunotherapies are targeting the glioblastoma immune environment.

The diagnosis of glioblastoma remains one of the most dismal in medical practice, with current standard care only providing a median survival of 14.6 months. The need for new therapies is desperately clear. Components of the tumour microenvironment are demonstrating growing importance in the field, given they allow the tumour to utilise pathways involved in autoimmune prevention, something that enables the tumour's establishment and growth. As with many different cancers, the search for a new standard has progressed to the design of immunotherapies, which aim to counteract the immune changes within this microenvironment. Serotherapy, adoptive lymphocyte transfer, peptide and dendritic cell vaccines and a range of other methods are currently under investigation, while intracranial infection has also been researched for its capacity to reverse glioblastoma mediated immunosuppression. Some of these new therapies have shown promise, but it is a long road ahead before their incorporation into glioblastoma standard therapy.

Association Between IDH1 and IDH2 Mutations and Preoperative Seizures in Patients with Low-Grade Versus High-Grade Glioma: A Systematic Review and Meta-Analysis.

BACKGROUND: Patients with brain tumors, particularly gliomas, commonly present with seizures. Higher incidence of seizure has been reported in low-grade gliomas and tumors located within the temporal and insular area. The association between IDH1 and IDH2 mutations with preoperative seizures in glioma and the magnitude of this association in low-grade versus high-grade gliomas are unclear. To clarify this relationship, a systematic review and meta-analysis was performed. METHODS: Following accepted guidelines and systematic review recommendations, electronic searches were performed in journal databases up to May 2017. Data were extracted and pooled via meta-analysis. RESULTS: We compared 782 patients with IDH1 and IDH2 mutations with 803 patients with wild-type IDH1 and IDH2 before surgery. There was a significant difference in seizure incidence between the IDH1 mutation group (61.6%) and wild-type IDH1 group (32.1%) (odds ratio 2.76; 95% confidence interval, 1.26-6.02; I2 = 73%; P = 0.01). Similar findings were observed in analysis of IDH1 and IDH2 mutations (odds ratio 2.74; 95% confidence interval, 1.74-4.33; I2 = 58%; P < 0.0001). The difference remained in both mutation groups (IDH1, IDH1 and IDH2) with grade II gliomas but not with grade III and IV gliomas. Patients with grade II gliomas showed a higher rate of IDH1 and IDH2 mutations and seizures than patients with grade III and IV gliomas. CONCLUSIONS: This study demonstrated a significant association of IDH1 and IDH2 mutations with incidence of preoperative seizures. This association was significant only in patients with low-grade glioma (grade II) and not in patients with higher grade gliomas (grade III and IV).

Systemic Assessment of Patients Undergoing Dental Implant Surgeries: A Trans- and Post-operative Analysis.

BACKGROUND: Procedure-related and patient-related factors influence the prognosis of dental implants to a major extent. Hence, we aimed to evaluate and analyze various systemic factors in patients receiving dental implants. MATERIALS AND METHODS: Fifty-one patients were included in the study, in which a total of 110 dental implants were placed. Complete examination of the subjects was done before and after placement of dental implants. Implant surgery was planned, and osseointegrated dental implants were placed in the subjects. Postoperative evaluation of the dental implant patients was done after 3 weeks. Anxiety levels were determined using State-Trait Anxiety Inventory (STAI) questionnaire on the surgery day and after 1 week of surgery. The participant describes how they feel at the moment by responding to twenty items as follows: (1) absolutely not, (2) slightly, (3) somewhat, or (4) very much. All the results were recorded and statistical analyzed by SPSS software. RESULTS: Out of 51, 29 patients were males while 22 were females, with ratio of 1.32:1. Female patients' mean age was 50.18 years while male patients' mean age was 52.71 years, with statistically nonsignificant difference between them. Functional rehabilitation was the main purpose of choosing dental implants in more than 90% of the subjects. Diameter of 3.75 mm was the shortest implants to be placed in the present study, whereas in terms of length, 8.5 mm was the shortest length of dental implant used in the present study. Tooth area in which maximum implants were placed in our study was 36 tooth region. Maximum implants were placed in Type II bone quality (n = 38). Implants installed in the mandible were clamped more efficiently than implants placed in the maxilla (P < 0.001). The difference of average STAI-State subscore before and after the surgery was statistically significant (P < 0.05; significant). CONCLUSION: Mandibular dental implants show more clamping (torque) than maxillary dental implants.

Gliomatosis cerebri: Prognosis based on current molecular markers.

This study aims to review the literature and identify key molecular markers affecting the prognosis of Gliomatosis cerebri (2) to evaluate the level of evidence and identify outstanding markers requiring further study. A literature search was conducted across 5 major databases using the key terms: "Molecular markers" AND "Gliomatosis cerebri" OR "diffuse astrocytoma." Critical appraisal and data presentation was performed inline with the PRISMA guidelines. Following search strategy implementation, 11 studies were included in the final review process. Our data demonstrates significant prognostic value associated with IDH1132H mutation and variable evidence surrounding the role of INA expression, MGMT promoter methylation and other factors. However, there are significant limitations in the level of evidence obtained. As the genetic basis for the pathogenesis of Gliomatosis cerebri continues to widen, there is little data on markers aside from IDH1 mutation available. IDH1132H mutation has been demonstrated to have significant effect on survival, particularly in patients with Gliomatosis cerebri type 2.

Endoscopic Endonasal versus Microsurgical Transsphenoidal Approach for Growth Hormone-Secreting Pituitary Adenomas-Systematic Review and Meta-Analysis.

BACKGROUND: The pituitary adenoma causing acromegaly is typically resected through a transsphenoidal approach and visualized with an operating microscope or endoscope. We undertook a systematic review and meta-analysis examining the clinical efficacy of endoscopic and microsurgical approaches. METHODS: Relevant studies using either endoscopic or microscopic transsphenoidal approaches for growth hormone pituitary adenomas were identified until February 2016. Data were extracted and analyzed according to predefined clinical end points. RESULTS: We identified 31 studies, in which 950 patients underwent endoscopic transsphenoidal resection and 2137 patients underwent microsurgical transsphenoidal resection. Patients undergoing microsurgery were less likely to present with hypothyroidism (10.7% vs. 19.1%, P = 0.033, 462 vs. 156 patients) and less likely to have macroadenomas (66.9% vs. 83.8%, P ≤ 0.001, 1484 vs. 884 patients); adenomas with cavernous sinus invasion (21.3% vs. 44.4%, P = 0.036, 592 vs. 558 patients); and a lower mean tumor volume (17.84 vs. 20.54 mm3, P = 0.012, 158 vs. 248 patients). Patients treated via the endoscopic approach were more likely to achieve remission for noninvasive macroadenomas (83.8% vs. 66.9%, P ≤ 0.001, 115 vs. 365 patients). Sinusitis (15.6% vs. 2.6%, P < 0.001, 241 vs. 295 patients) and intraoperative cerebrospinal fluid leak (21.6% vs. 1.0%, P = 0.022, 697 vs. 127 patients) were more common in patients treated endoscopically, and meningitis (0.7% vs. 1.7%, P = 0.027, 511 vs. 1513 patients) was more common in patients undergoing a microsurgical approach. CONCLUSIONS: Our study shows the clinical utility of the endoscopic approach and demonstrates potential benefits including increased remission rates with noninvasive macroadenomas and a lower rate of meningitis.

DISC (Degenerate-disc Infection Study With Contaminant Control): Pilot Study of Australian Cohort of Patients Without the Contaminant Control.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To evaluate if degenerative disc-related back or neck pain and/or radicular symptoms are caused by infection with low virulent bacterial organisms. SUMMARY OF BACKGROUND DATA: The potential relationship between disc infection and disc degeneration-related symptoms remains controversial, with contradictory evidence available in the literature. Several studies have demonstrated the presence of infected extruded nucleus tissue from first-time disc herniation, implicating the role of disc microbial infection in disc degeneration. The current study is a pilot study evaluating if high infection rates are prevalent in the Australian degenerate disc cohort. METHODS: Institutional ethics approval was obtained (HREC 13/218). The pilot project was a single spine center prospective cohort of patients undergoing spine surgery for degenerate disc disease. In each case, disc material was obtained and prolonged aerobic and anaerobic cultures performed as per methods used by Stirling et al. RESULTS: To date, a total of 168 patients have been enrolled, with male: female = 1:1. Surgical caseload includes 17.9% anterior cervical fusion, 35.0% anterior lumbar fusion, 40.7% lumbar discectomy, and 5.7% posterior lumbar fusions; 34.1% patients presented with neck pain, 31.6% with arm pain, 59.3% with leg pain, and 64.2% with back pain, and 20.2% of the patients received transforaminal or epidural or facet joint injections prior to surgery. In this pilot study, 19.6% were culture positive, with P. acnes predominant in 50%. Disc-only cultures were positive in 27.8% of lumbar cases and 18.5% of cervical cases, with predominant organisms being P. acnes. CONCLUSION: Similar to the infection rates from previous studies, this Australian cohort had 19.6% infection rates when disc-only cultures are performed. P. acnes is the predominant organism followed by Streptococcus sp. It is imperative to perform contaminant controls as such high infection with skin bugs is a significant finding. LEVEL OF EVIDENCE: 4.

Laparotomy vs minimally invasive laparoscopic ventriculoperitoneal shunt placement for hydrocephalus: A systematic review and meta-analysis.

Ventriculoperitoneal shunt (VPS) surgery is the most commonly used method for the treatment of hydrocephalus. Traditionally, distal catheters in the VPS surgery have been placed either through a standard small open laparotomy or via a laparoscopic technique. Although there are many studies demonstrating the benefits of a minimally invasive approach, limited research has directly compared the two techniques used in VPS surgery. The present meta-analysis aims to provide the first comprehensive review of all published observational studies and randomized controlled trials reporting outcomes of laparotomy and laparoscopy in VPS. Electronic searches were performed using six databases from their inception to February 2015. Relevant studies comparing conventional laparotomy and a laparoscopic video-guided approach in VPS were included. Data were extracted and analyzed according to predefined clinical endpoints. A total of ten studies were identified for inclusion in the present analysis. Results indicated that the laparoscopic technique was associated with a slight but significant reduction in operating time (∼ 10 min), a significantly lower rate of abdominal malposition, distal obstruction and distal shunt failure. There was no difference between the laparotomic and laparoscopic approaches in the length of hospital stay, complication rate, proximal shunt failure or infection rate. The present systematic review and meta-analysis demonstrated that the laparoscopic technique in VPS surgery is associated with reduced shunt failure and abdominal malposition compared to the open laparotomy technique, with no significant difference in rates of infection or other complications. The lack of studies with high levels of evidence may contribute to bias in our conclusions and the long-term relative merits require validation by further prospective, randomized studies.

An open-label comparison of local anesthesia with or without sedation for minor hand surgery.

BACKGROUND: The purpose of this study was to assess satisfaction and pain intensity in patients undergoing minor hand surgery under local anesthesia (LA) with or without sedation. METHODS: Seventy-three adult patients presenting to two hand surgeons were enrolled in this prospective observational study in 2012. They completed questionnaires prior to surgery (current pain intensity, Patient Health Questionnaire-2 (PHQ-2) to measure symptoms of depression, Pain Self-Efficacy Questionnaire (PSEQ) to assess the effective coping strategy of pain self-efficacy) and within 48 h after surgery (satisfaction with surgery, satisfaction with anesthesia, pain during the injection, and pain during the procedure). Thirty-seven patients had carpal tunnel release (bilateral in 3), 22 had release of one or more trigger digits, and 12 had excision of a benign tumor, gouty tophus (1 patient), or foreign body (1 patient). Forty-six patients chose LA and 27 chose LA with sedation. RESULTS: There was no difference in satisfaction with surgery or anesthesia by the type of anesthesia. Satisfaction with surgery was associated with older age alone. Satisfaction with anesthesia was associated with no prior surgery for the same condition. Pain during injection and during the procedure were significantly higher without sedation. Pain during injection was associated with younger age and LA. No factors were associated with pain during the procedure. CONCLUSIONS: Patients that had local anesthesia immediately prior to incision with tourniquet use during surgery had more pain during the procedure but were equally satisfied on average with surgery and with anesthesia compared to patients that had sedation.

Clinical characteristics and long-term outcome of surgery for hypothalamic hamartoma in children with refractory epilepsy.

CONTEXT: Hypothalamic hamartomas (HH) are ectopic masses of neuronal and glial tissue most commonly presenting with medically refractory gelastic seizures with evolution to other seizure types. They are also associated with cognitive and behavioral problems to varying extent. Surgery has been found to improve quality of life in more than 50% of patients. AIM: To evaluate the clinical characteristics and long-term outcome of surgery in children with HH and refractory epilepsy. MATERIALS AND METHODS: A retrospective analysis of presurgical, surgical, and postsurgical data of six children who underwent surgery for HH and had at least 3 years follow-up was performed. RESULTS: SIX CHILDREN (MALE: female = 5:1) aged 3-16 years (at the time of surgery) underwent surgical resection of HH for refractory epilepsy. At last follow-up (range 3-9 years), three children were in Engel's class I, two in Class II, and one in class III outcome. Significant improvement in behavior, quality of life was noted in four children; while the change in intelligence quotient (IQ) was marginal. CONCLUSIONS: Medically refractory epilepsy associated with behavioral and cognitive dysfunction is the most common presentation of HH. Open surgical resection is safe with favorable outcome of epilepsy in 50% with significant improvement in behavior and marginal change in cognitive functions.

Durable thrombosis in a rat model of arteriovenous malformation treated with radiosurgery and vascular targeting.

OBJECT: Radiosurgical treatment of brain arteriovenous malformations (AVMs) has the significant shortcomings of being limited to lesions smaller than 3 cm in diameter and of a latency-to-cure time of up to 3 years. A possible method of overcoming these limitations is stimulation of thrombosis by using vascular targeting. Using an animal model of AVM, the authors examined the durability of the thrombosis induced by the vascular-targeting agents lipopolysaccharide and soluble tissue factor conjugate (LPS/sTF). METHODS: Stereotactic radiosurgery or sham radiation was administered to 32 male Sprague-Dawley rats serving as an animal model of AVM; 24 hours after this intervention, the rats received an intravenous injection of LPS/sTF or normal saline. The animals were killed at 1, 7, 30, or 90 days after treatment. Immediately beforehand, angiography was performed, and model AVM tissue was harvested for histological analysis to assess rates of vessel thrombosis. RESULTS: Among rats that received radiosurgery and LPS/sTF, induced thrombosis occurred in 58% of small AVM vessels; among those that received radiosurgery and saline, thrombosis occurred in 12% of small AVM vessels (diameter < 200 µm); and among those that received LPS/sTF but no radiosurgery, thrombosis occurred at an intermediate rate of 43%. No systemic toxicity or intravascular thrombosis remote from the target region was detected in any of the animals. CONCLUSIONS: Vascular targeting can increase intravascular thrombosis after radiosurgery, and the vessel occlusion is durable. Further work is needed to refine this approach to AVM treatment, which shows promise as a way to overcome the limitations of radiosurgery.

Multifocal spinal meningeal melanocytoma: an illustrated case review.

Primary melanocytic tumors of the central nervous system are rare. In this article the authors describe a case of C1C2 intradural extramedullary melanocytoma in a 43-year-old patient who presented with neck pain. C1-3 laminectomy was performed followed by excision of the lesion and an adjoining satellite nodule, along with the dural attachment. The histopathological features were consistent with a meningeal melanocytoma despite the presence of a satellite nodule. The patient has no evidence of recurrence during the six month follow up period. A brief review of literature pertaining to the radiological features, pathological findings, management and prognosis of this rare tumor is discussed.

Minimal access spine surgery (MASS) for decompression and stabilization performed as an out-patient procedure for metastatic spinal tumours followed by spine stereotactic body radiotherapy (SBRT): first report of technique and preliminary outcomes.

We report a novel approach in the treatment of spinal metastases with epidural disease and mechanical instability using a combined minimal access spine surgery (MASS) technique followed by spine stereotactic body radiotherapy (SBRT). This study was performed as a retrospective review of the first ten consecutive patients treated with this combined approach. The MASS technique was based on a tubular retraction system to gain access for decompression and mechanical stabilization achieved using methyl-methacrylate (MMA) applied under direct visualization. SBRT consisted of one to five image-guided high dose per fraction treatments. Eight patients were symptomatic at baseline. Pain, disability, and quality of life (QOL) were prospectively determined using the visual analogue score (VAS), Oswestry Disability Index (ODI), and Short-Form-36 version 2, respectively. The median follow-up was 13 months (range, 3-18). MASS successfully decompressed each patient. The median blood loss was 335 ml. Following MASS, the median time to SBRT treatment planning was 6.5 days and subsequent median time to treatment was 7 days. Local control was observed in 7 of the 10 patients. Improvements in VAS, ODI and QOL were observed post-SBRT. We report preliminary efficacy for our MASS-SBRT combined approach for patients with spinal metastases, mechanical pain and epidural disease.

Acanthamoeba meningoencephalitis in an immunocompetent patient: an autopsy case report.

Chronic granulomatous CNS infections may be caused by tuberculosis, fungi and rarely by free-living amoeba, especially in immunocompromised individuals. We report a rare, fatal case of granulomatous amoebic encephalitis in an immunocompetent patient mimicking CNS tuberculosis, and review the imageological features and diagnostic tests.