"Undercutting of the corresponding rib": a novel technique of increasing the length of donor in intercostal to musculocutaneous nerve transfer in brachial plexus injury.

Intercostal nerves (ICN) are often utilized as donors for various neurotization procedures in brachial plexus injuries. ICN to musculocutaneous nerve (MCN) transfer is usually a standard in pan brachial plexus injuries, in order to restore flexion at the elbow. A tensionless co-aptation of the donor-recipient nerves often necessitates either a distal dissection of the ICNs where the number of fascicles is rather low or a proximal dissection, often at the cost of dissection of the serratus anterior digitation with a risk of later fibrosis and adhesion. We report two cases of pan brachial plexus injuries where ICN-MCN transfer was performed to restore elbow function. These patients underwent clinical and electrodiagnostic evaluation before surgery. We used the standard technique of harvesting ICNs 3-5, with our technical modification of "undercutting of rib" for increasing the donor length. The procedure was applied in two patients with pan brachial plexus injury (mean age = 23). Mean duration since the injury to surgery was ten months. Both patients underwent tensionless anastomosis with a combination of suture and fibrin glue co-aptation. While one patient had some improvement in elbow flexion, another one was under active rehabilitation protocol during follow-up. We found that undercutting of the ribs near serratus digitations can allow mobilization of the ICN from its groove, which in turn lengthens the donor nerve length without violating the serratus anterior digitations and without too anterior dissection of the nerve. It can be a viable option when a tensionless co-aptation at the axilla is otherwise not feasible intraoperatively.

Surgical excision of large-to-giant petroclival meningiomas focusing on the middle fossa approaches: The lessons learnt.

INTRODUCTION: Petroclival meningiomas are based on or arising from the petro-clival junction in upper two-thirds of clivus, medial to the fifth cranial nerve. This study focuses on the surgical experience in resecting large-giant tumors >3.5 in size predominantly utilizing middle fossa approaches. MATERIAL AND METHODS: 33 patients with a large or a giant petroclival meningioma (size >3.5 cm) were included. Clinical features, preoperative radiological details, operative findings, and postoperative clinical course at the follow-up visit were reviewed. Group A tumors (n = 17,51.5%) were sized 3.5cm-5cm, and Group B (n = 16,48.48%) tumors were of size >5 cm. Extent of resection was described as 'gross total' (no residual tumor), 'near total' (<10% residual tumor) and 'subtotal resection' (>10% residual tumor). Glasgow outcome scale (GOS) quantitatively scored postoperative neurological outcome (mean follow up: 35.77months; range 1-106 months). RESULTS: 25 (75.8%) patients had tumour extension into both supratentorial and infratentorial compartments. Extension into Meckel's cave (n = 25,75.8%), cavernous sinus (n = 17,48.4%], sphenoid sinus (n = 12,38.7%] and suprasellar area [12,38.7%] was often seen. In 31 (93.9%) patients, the tumor crossed the midline in the premedullary, prepontine, and interpeduncular cisterns. In 20 (60.6%) patients, the tumour extended below and posterior to the internal auditory meatus (IAM), while in 13 (39.4%) patients, the tumor was located above and anterior to the IAM. Kawase's approach was the most commonly used approach in 16 (48.48%) patients and resulted in maximum tumor resection. Other approaches included half-and-half (trans-Sylvian with subtemporal) [n = 6, 18.18%]; frontotemporal craniotomy with orbitozygomatic osteotomy [n = 1, 3%] and retromastoid suboccipital craniectomy (RMSO) [n = 7, 21.21%]. In 2 (6.06%) patients, staged anterior petrosectomy with RMSO; and, in 1, staged presigmoid with half-and-half approach was used. Gross total excision was achieved in 12 (36.36%), near-total excision in 15 (45.45%) and subtotal excision in 6 (18.18%) patients. 20 (60.6%) patients had a good functional outcome; 6 patients succumbed due to meningitis, pneumonitis, perforator injury or a large tumor recurrence. CONCLUSIONS: Half-and-half approach was used in tumors with middle and posterior cranial fossae components often extending to the suprasellar region. Kawase's anterior petrosectomy was utilized in resecting tumors with predominant posterior fossa component (along with a small middle fossa component) that was crossing the midline anterior to the brain stem, and mainly situated superomedial to the IAM. Tumors confined to the posterior fossa, that extended laterally and below the IAM were resected utilizing the RMSO approach. Occasionally, a combination of these approaches was used. Middle fossa approaches help in significantly avoiding morbidity by an early devascularisation and decompression of the tumor. In tumors lacking a plane of cleavage, a thin rim of capsule of tumor may be left to avoid brain stem signs.

Simultaneous odontoid excision with bilateral posterior C1-2 distraction and stabilization utilizing bilateral posterolateral corridors and a single posterior midline incision.

A simultaneous odontoid decompression and bilateral posterior atlanto-axial facetal distraction, C1-2 joint spacer/bone graft placement and stabilization may be performed utilizing the 'posterior-only' approach. This procedure may be performed utilizing a single posterior midline incision, a bilateral posterior approach to the C1-2 facet joints and a bilateral posterolateral approach to the odontoid process and C2 body. It may be carried out in situations where a C1-2 non-reduction/partial reduction using a 'posterior alone' procedure is anticipated due to the complex bony/soft tissue configuration anterior at the thecal sac existing at the cervicomedullary junction. In the four cases described in this report, the procedure led to a successful circumferential decompression at the level of foramen magnum along with posterior C1-2 facetal distraction and stabilization in various complex craniovertebral junction anomalies (atlantoaxial dislocation [AAD] and/or a high basilar invagination [BI] associated with a significantly retroverted dens, along with a rotatory component, due to grossly asymmetrical facet joints). This technique may also be utilized in those diseases that result in an anterior osteoligamentous mass at the CVJ associated with C1-2 instability.

Perfusion MR imaging of enhancing brain tumors: Comparison of arterial spin labeling technique with dynamic susceptibility contrast technique.

OBJECTIVE: Arterial spin labeling (ASL) magnetic resonance (MR) perfusion is a noninvasive and repeatable method for quantitatively measuring cerebral blood flow (CBF). This study aims to compare measurements of ASL-derived CBF with dynamic susceptibility contrast (DSC) MRI in the assessment of enhancing brain tumors (primary and metastatic), with an aim to use ASL as an alternative to DSC. MATERIALS AND METHODS: Thirty patients with newly diagnosed brain tumors (16 meningiomas, 6 gliomas, 3 metastases, 2 cerebellopontine angle schwannoma, 1 central neurocytoma, and 2 low-grade gliomas) were examined using a 3T MR scanner. Values of CBF, regional cerebral blood flow (rCBF), and regional cerebral blood volume (rCBV) were determined in the tumor (T) as well as in the contralateral normal gray matter (GM) and white matter (WM). Tumor-to-GM or WM CBF, rCBF, and rCBV ratios were calculated to estimate normalized perfusion values (i.e., ASL normalized tumor blood flow [nTBF], DSC nTBF, and DSC normalized tumor blood volume [nTBV]) from the ASL and DSC techniques. ASL and DSC MRI derived perfusion parameters were compared using paired t-test and correlated using Pearson correlation coefficient. RESULTS: Mean values for ASL nTBF and DSC nTBF using contralateral GM as the reference point were 2.98 ± 1.67and 2.91 ± 1.43, respectively. A very strong correlation coefficient was found between ASL nTBF and DSC nTBF with contralateral GM as the reference region (r = 0.903; R2= 0.813). Mean DSC nTBF and DSC nTBV also showed strong correlation (r = 0.83; R2= 0.701). CONCLUSION: Our study results suggested that measurement of CBF from ASL possesses the potential for a noninvasive assessment of blood flow in intracranial tumors as an alternate to DSC MRI, in those patients requiring multiple follow-up imaging and in patients with impaired renal functions.

Pediatric anterior visual pathway gliomas: trends in fluid and electrolyte dynamics and their management nuances.

PURPOSE: Trends in pre- and postoperative fluid, electrolyte and osmolarity changes, and incidence of diabetes insipidus (DI) were assessed in pediatric patients with anterior visual pathway gliomas (AVPGs). METHODS: Thirty-three patients with AVPGs (age < 16 years) were divided into two groups: (1) no hypothalamic involvement [NHI; n = 17 (51.5 %) including optic (5, 15.2 %); chiasmal (5, 15.2 %); and optico-chiasmal (7, 21.2 %)] and (2) hypothalamic involvement [HI; n = 16 (48.5 %) including chiasmal-hypothalamic (12, 36.4 %) and optico-chiasmal-hypothalamic (4, 12.1 %)]. Frontotemporal transylvian decompression/biopsy was undertaken in 32 patients, while one patient (with severe diencephalic syndrome) was treated conservatively. Their endocrinal and fluid/electrolyte balance, serum osmolarity, and DI status were noted. Chi-square test compared clinical/endocrinological parameters, and unpaired T test evaluated mean daily water/electrolyte changes (p value < 0.05: significant). RESULTS: Significant visual deterioration (perception of light (PL) positive (left: n = 4; right: n = 4) and PL negative (left: n = 5; right: n = 5) was encountered due to optic atrophy. Larger lesions (>3 cm), hydrocephalus [(NHI: n = 7, 41.18 %; HI: n = 12, 75 %), endocrinopathies (p = 0.047), Na(+)/K(+) derangements, and preoperative DI (n = 8, p = 0.004)] were present in the group HI. Increased postoperative urine output (almost double in those with hypothalamic involvement) and hypernatremia/hyperkalemia were seen in group HI until the sixth postoperative day (p < 0.05). Two patients with progressive hypernatremia without increased urine output showed dehydration on central venous pressure monitoring and improved with vasopressin administration. Five patients [NHI: n = 4 (23.5 %); HI: n = 1 (6.3 %)] had neurofibromatosis types I and 3 (NHI: n = 1, 5.9 %; HI: n = 2, 12.5 %) had a diencephalic syndrome. CONCLUSIONS: Hypothalamic infiltration significantly increases the incidence of DI and fluid and electrolyte disturbances. Strict vigilance over postoperative fluid balance is mandatory during the first postoperative week. Rapidly rising serial serum sodium values without increased urine output mandates immediate central venous pressure measurement to detect DI associated with dehydration.

Reshaping the zygomatic complex: A "small step" in frontotemporal craniotomy and a "big leap" in exposure.

CONTEXT: Pterional or fronto-temporal craniotomy, developed by Prof. M. G. Yasargil, is among the most familiar skull base surgery techniques. The cranio-orbito zygomatic (COZ) approach evolved to address the significant limitations of the pterional exposure in excising some parasellar lesions. Although extremely versatile, the COZ technique involves extensive dissection of the cranio-facial soft tissue and reconstruction towards the end of the procedure. The zygomatic reshaping is a minor modification of the pterional approach, which enhances the exposure possible through the classical approach and often circumvents the need for an orbito-zygomatic osteotomy. AIMS: To demonstrate the technique of reshaping of the zygomatic complex for an optimum surgical exposure and cosmetic results. MATERIALS AND METHODS: Between April 2013 and December 2014, 8 patients with various middle and anterior skull base lesions were operated using this technique. These patients form the clinical material for this study. The clinical details, radiological images and follow-up data of these patients were collected for this clinical series. RESULTS: No mortality or significant morbidity were noted in this series. The post-operative cosmetic results were also acceptable. CONCLUSIONS: A quick and easy modification of the classical pterional approach through zygomatic reshaping has the potential to provide a significantly enhanced surgical exposure for parasellar lesions. Using this approach, it might be possible to avoid an extensive orbito-zygomatic osteotomy in suitable lesions.

A I-segment aneurysms: management protocol based on a new classification.

BACKGROUND: Aneurysms of proximal (AI)-segment of anterior cerebral artery (ACA) constitute <1% of all intracranial aneurysms. AIM: Management dilemmas of A1-segment aneurysms were studied utilizing a new classification based upon their location on the longitudinal and circumferential axis of A1-segment. SETTING AND DESIGN: Tertiary care referral center. MATERIALS AND METHODS: This is a retrospective analysis of 14 patients (0.98%; mean age: 38.02 ± 15.74 years) with AI-segment aneurysms. The data collected included clinical features, computed tomography (CT) scan and CT-angiography (CTA)/digital subtraction angiography (DSA) findings, modified Hunt and Hess (H and H) grade, surgical steps and difficulties encountered. RESULTS: The modified Hunt and Hess (H and H) grades in the 14 patients were: grade I in two, grade II in two, grade III in four, grade IV in five and grade V in 1. The mean ictus-admission duration was 5.07 ± 2.30 days (range: 1-10 days). Multiple aneurysms were two. Thirteen patients underwent clipping and one, wrapping. Bilateral lateral ventricle hemorrhage occurred in 8 (66%) patients and frontal intracerebral hematoma in 2 (16.66%) patients. In one patient, the aneurysm could only be detected following the third angiogram. AI-aneurysms were classified as proximal (n = 6), distal (n = 7), and mid-segment (n = 1); and, anterior (n = 2), posterior-inferior (n = 7) and posterior-superior (n = 5). Follow-up (range: 6 months-10 years, mean: 2.9 years) recovery (assessed using Modified Rankin's score or mRS) correlated with preoperative status. The preoperative H and H grade and follow-up mRS status were as follows: H and H I (n = 2): mRS 0 (asymptomatic, n = 2); H and H II (n = 2): mRS 1 (minor symptoms without disability, n = 2); H and H III (n = 4):mRS 1 (n = 2) and mRS 2 (slight disability but performing unassisted activities of daily living, n = 1); H and H IV (n = 5): mRS 3 (moderate disability, requiring help for daily living but unassisted walking, n = 2) and mRS 4 (moderately severe disability, requiring help for daily living and walking, n = 2). One patient each from H and H grade III, IV and V died (mRS 6) during treatment due to severe vasospasm, pneumonitis and septicemia. CONCLUSIONS: AI-segment aneurysms have unique properties: rupturing of small-sized aneurysms; multiplicity; undetectable on initial imaging; frontal lobar/intraventricular bleeding; origin from main trunk and not bifurcating points; neck obscuration by AI-trunk; close proximity to perforators; and, associated AI-segment and ACA anomalies. A new classification identifies surgical difficulties inherent in different sites of origin of A1-aneurysms.

Large/giant meningiomas of posterior third ventricular region: falcotentorial or velum interpositum?

Surgical excision of rare, large-to-giant posterior third ventricular (PTV) meningiomas [including velum-interpositum meningiomas (VIM; postero-superior venous complex displacement; without falco-tentorial attachment) and falco-tentorial meningiomas (FTM; falco-tentorial attachment; displacing major veins antero-inferiorly)] is extremely challenging. To study the management nuances in the excision of large-to-giant PTV meningiomas. Tertiary care referral center. Four patients with large (>3 cm; n = 2) and giant (>5 cm; n = 2) meningiomas (FTM = 2; VIM = 2, mean tumor size = 4.9 cm) underwent occipital transtentorial approach (OTT) for tumor excision. One also underwent a second-stage supracerebellar infratentorial (SCIT) approach. The side of approach was determined by lateral tumor extension and venous displacement (right = 3, left = 1). Near-total removal or subtotal excision (<10% remaining) with radiotherapy was performed in 2 patients each, respectively. At follow-up (mean: 14.75 months), clinical improvement without tumor recurrence/re-growth was achieved. Extent of excision was determined by position of great vein of Galen; tumor attachment to falco-tentorium or major veins; its consistency; its lateral and inferior extent; and, presence of a good tumor-neuraxial arachnoidal plane. OTT is the preferable approach for large-to-giant meningiomas as it provides a wider corridor and better delineation of tumor-neurovascular arachnoidal interface.

Looking Beyond the Anterolateral Skull Base with Frontotemporal Dural Fold Unlocking and Extradural Clinoidectomy: A Series of 17 Cases Deciphering the Translation from a Cadaver to Real, and Real to Pathologically Distorted Anatomy.

Objective: This article aims to discuss the surgical nuances and major adjustments necessary in unlocking the frontotemporal dural fold (FTDF) and extradural anterior clinoidectomy (EDAC) in actual cases, allowing translation from the cadaveric to a clinical scenario. Materials and Methods: We retrospectively reviewed the technical details of 17 procedures over 8 years, where both the initial steps (FTDF unlocking and EDAC) were performed. Lesions involving or extending to the anterolateral skull base, like the suprasellar cistern, optico-carotid cistern, interpeduncular cistern, petrous apex, and cavernous sinus, were included. The clinical data of the patients were retrieved retrospectively from the hospital information system (HIS) and in-patient records. This study was approved as a multicenter individual project with IEC No: 2020-342-IP-EXP-34. Results: An illustrated note of the common steps and outcome of the 17 procedures of unlocking the FTDF and EDAC done is presented. The technique provided adequate exposure in performing aneurysmal clipping (posterior communicating artery [P. com], basilar top, and superior hypophyseal artery [SHA] aneurysm), giant pituitary adenoma (Wilson Hardy grade 4E, n = 2), fifth nerve schwannoma (n = 4), right Meckel's cave melanoma, cavernous hemangioma (n = 4), petroclival meningioma (n = 2), and clival chordoma. Temporary and permanent cranial nerve palsy as a procedure-related complication was seen in 11.8% (n = 2) each. Complete excision was achieved in 13 (n = 13/14) patients with tumors. Conclusion: FTDF unlocking and EDAC are elegant procedures providing reasonable access to the anterolateral skull base for myriad pathologies. Brain bulge, cavernous sinus bleeding, and losing the plane of dural duplication were significant challenges in switching from cadaveric to a clinical scenario.

Anterior Skull Base Meningioma: Surgical Approach and Complication Avoidance.

Introduction Endoscopic endonasal approach (EEA) and keyhole transcranial approaches (TCAs) are being increasingly used in anterior skull base meningioma (ASBM) surgery. Objective We compare tumor resection rates and complication profiles of EEA and supraorbital keyhole approach (SOKHA) with conventional TCAs. Methods Fifty-four patients with ASBM (olfactory groove meningioma [OGM], n = 19 and planum sphenoidale/tuberculum sellae meningioma [PSM/TSM], n = 35) operated at a single center over 7 years were retrospectively analyzed. Results The overall rate of gross total resection (GTR) was higher in OGM (15/19, 78.9%) than PSM-TSM group (23/35, 65.7%, p = 0.37). GTR rate with OGM was 90% and 75% with TCA and EEA. Death ( n = 1) following medical complication (TCA) and cerebrospinal fluid leak requiring re-exploration ( n = 2, one each in TCA and EEA) accounted for the major complications in OGM. For the PSM/TSM group, the GTR rates were 73.3% ( n = 11/15), 53.8% ( n = 7/13), and 71.4% ( n = 5/7) with TCA, EEA, and SOKHA, respectively. Seven patients (20%) of PSM-TSM developed major postoperative complications including four deaths (one each in TCA and SOKHA, and two in EEA groups) and three visual deteriorations. Direct and indirect vascular complications were common in lesser invasive approaches to PSM-TSM especially if the tumor has encased intracranial arteries. Conclusion No single approach is applicable to all ASBMs. TCA is still the best approach to obtain GTR but has tissue trauma-related problems. SOKHA may be a good alternative to TCA in selected PSM-TSMs, while EEA may be an alternate option in some OGMs. A meticulous patient selection is needed to derive reported results of EEA for PSM-TSM.

Postoperative Seizure Control in Adult Diffuse Insular Gliomas Presenting with Seizures: A Retrospective Single-Center Experience and Proposal of a Novel Risk Scoring System.

Background: Studies on insular gliomas (IGs) generally focus on the oncological endpoints with a relative scarcity of literature focusing on the seizure outcomes. Objectives: To study the predictors of long-term postoperative seizure control in IG and propose a novel risk scoring system. Methods: Histopathologically proven, newly diagnosed adult IGs (>18 years) operated over a 10-year period were studied for postoperative seizure control as per International League Against Epilepsy (ILAE) grades at 6 weeks and at last follow-up (minimum of 6 months, median 27 months). Logistic regression analysis was performed and regression coefficients with nearest integers were used to build a risk prediction model. Receiver operator curve (ROC) analysis determined the predictive accuracy of this model. Results: The 6-week postoperative seizure freedom dropped to 41% at the last follow-up. The seizure-free group lived longer (100.69 months, 95% CI = 84.3-116.99 (60%)) than those with persistent postoperative seizures (27.92 months, 95% CI = 14.99-40.86). Statistically significant predictors (preoperative seizure control status, extent of resection, tumor extension to temporal lobe, and lack of postoperative adjuvant therapy) were used to compute a risk score, the score ranging from 0 to 9. A score of four most optimally distinguished the risk of postoperative seizures with an area under the ROC of 91.4% (95% CI: 84.1%, 98.7%, P < 0.001). Conclusion: In our experience, around 60% of patients obtained seizure freedom after surgery, which reduces over time. Control of seizures paralleled survival outcomes. Our proposed scoring system may help tailor management strategies for these patients.

Pediatric glioblastoma: clinico-radiological profile and factors affecting the outcome.

BACKGROUND AND PURPOSE: Glioblastoma in the pediatric age group is relatively rare. As a result, it has been difficult to deduce any consistent clinico-radiological and pathological profiles on these patients. Also, the prognostic factors affecting the survival in pediatric glioblastoma are not as well defined as in adults. PATIENTS AND METHODS: In this retrospective series, 65 pediatric patients (age ≤ 18 years) from January 1995 to December 2011 with histopathologically proven diagnosis of intracranial glioblastoma were studied. Clinico-radiological, pathological, treatment, and follow-up data were collected. Progression-free and overall survivals were assessed using the Kaplan-Meier method. RESULTS: The male-to-female ratio was 2.6:1 with a mean age of 13.29 ± 4.53 years (range 2-18 years). Headache with or without vomiting (n = 51, 78 %), followed by seizures (n = 42, 65 %), and focal deficits (n = 31, 47 %) were the leading symptoms. Forty-nine (75 %) patients had tumors located superficially, whereas there were 16 patients with deeply located glioblastomas (25 %). Gross total tumor excision was achieved in 43 (66 %) patients, while the remaining patients had incomplete excision (n = 22, 34 %). Mean follow-up was 17.7 months (range 1.5-119 months). The median progression-free and overall survivals were 10 and 20 months, respectively. Extent of resection was found to be the independent predictor of survival (p value = 0.002). CONCLUSION: Pediatric glioblastomas are associated with longer progression-free as well as overall survivals. Extent of tumor resection is the strongest predictor of survival in pediatric glioblastoma. Hence, an aggressive surgical resection may fetch a better outcome in children with glioblastoma.

Microneurosurgery for Spinal Dural Arteriovenous Fistula- Operative Video.

Background and Introduction: Spinal dural arteriovenous fistula (SDAVF) is a rare but curable condition. Microsurgery is a highly effective and readily affordable treatment modality. Objective: We present a surgical video of SDAVF to demonstrate the operative nuances involved. Surgical Technique: A 53-year-old wheelchair-bound man with spastic paraparesis for 1.5 years was found to have a SDAVF at L1/2 level with a single fistula point. During surgery, a L1-L2 laminectomy and durotomy revealed a dilated vein accompanying the nerve root exiting L1/2 foramen that showed early filling on indocyanine green (ICG) video angiography. This vein was occluded, and a segment of this vein was removed during surgery, which led to resumption of normal spinal cord perfusion. Results: The patient showed gradual recovery of lower limb motor power and improved to assisted ambulation after 3 months. Conclusions: Surgery is a simple, effective, and cost-effective treatment option in SDAVF.

The current status and surgical outcome of the minimally invasive techniques for lumbar interbody fusion in India: A systematic review and meta-analysis.

Objective: The global shift of trends to minimally invasive spine (MIS) surgery for lumbar degenerative diseases has become prominent in India for few decades. We aimed to assess the current status of MIS techniques for lumbar interbody fusion and their surgical outcomes in the Indian population. Materials and Methods: A systematic review (following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines) was performed using PubMed and Google Scholar till November 2020. The primary (visual analog scale [VAS] and oswestry disability index [ODI] scores; intraoperative blood loss; duration of surgery; duration of hospital stay, and fusion rate) and secondary (wound-associated complications and dural tear/cerebrospinal fluid (CSF) leak) outcomes were analyzed using Review Manager 5.4 software. Results: A total of 15 studies comprising a total of 1318 patients were included for analysis. The pooled mean of follow-up duration was 26.64 ± 8.43 months (range 5.7-36.5 months). Degenerative spondylolisthesis of Myerding grade I/II was the most common indication, followed by lytic listhesis, herniated prolapsed disc, and lumbar canal stenosis. The calculated pooled standard mean difference (SMD) suggested a significant decrease in postoperative ODI scores (SMD = 5.53, 95% confidence interval [CI] = 3.77-7.29; P < 0.01) and VAS scores (SMD = 6.50, 95% CI = 4.6-8.4; P < 0.01). The pooled mean blood loss, duration of postoperative hospital stay, duration of surgery, and fusion rate were 127.75 ± 52.79 mL, 4.78 ± 3.88 days, 178.59 ± 38.69 min, and 97.53% ± 2.69%, respectively. A total of 334 adverse events were recorded in 1318 patients, giving a complication rate of 25.34%. Conclusions: Minimally invasive transforaminal lumbar interbody fusion (TLIF) is the most common minimally invasive technique employed for lumbar interbody fusion in India, while oblique lumbar interbody fusion is in the initial stages. The surgical and outcome-related factors improved significantly after MIS LIF in the Indian population.

Balancing the Extent of Resection and Ischemic Complications in Insular Glioma Surgery: Technical Nuances and Proposal of a Novel Composite Postoperative Outcome Index.

Background: Maximal safe resection remains the most desired goal of insular glioma surgery. Intraoperative surgical adjuncts provide better tumor visualization and real-time "safety" data but remain limited due to a high cost and limited availability. Objective: To highlight the importance of anatomical landmarks in insular glioma resection and avoidance of vascular complications. We also propose to objectify the onco-functional balance in insular glioma surgery. Methods: Forty-six insular gliomas operated upon by a single surgeon between January 2015 and February 2020 were reviewed, focusing on the operative technique and clinical outcomes. A novel composite postoperative outcome index (CPOI) was designed, comprising the extent of resection and permanent postoperative deficits, and utilized to assess the surgical outcomes. Results: Gross-total, near-total, and subtotal resections were achieved in 10.9%, 52.1% (n = 24), and 36.9% (n = 17) patients, respectively. The median overall survival (OS) was 20 months (95% CI = 9.56-30.43). CPOI was optimal in 38 patients (82.6%). A well-defined tumor margin (P = 0.01) and surgeon's experience (P = 0.04) were significantly associated with an optimal CPOI. Out of seven (15.2%) patients who developed permanent neurological deficits, three (6.5%) patients had severe disability. Favorable prognostic factors of survival included younger age (<40 years) (P = 0.002), tumors with only frontal lobe extension (P = 0.011), tumors with caudate head involvement (P = 0.04), and non-glioblastoma histology (P = 0.006). Conclusion: Tumor margin and increasing surgeon experience are critical to an optimal postoperative outcome. Respecting the basi-sulcal plane is key to lenticulostriate artery preservation. Caudate head involvement is a new favorable prognostic factor in insular gliomas.

Spinal Dermoid and Epidermoid Cyst: An Institutional Experience and Clinical Insight into the Neural Tube Closure Models.

Objectives The spinal dermoid and epidermoid cysts (SDECs) are rare entities comprising less than 1% of pediatric intraspinal tumors. The present study aims to extrapolate the clinicoradiological data, in order to identify the most plausible neural tube closure model in human and provide a retrospective representation from our clinical experience. Materials and Methods We collected the details of all histologically proven, newly diagnosed primary SDECs who underwent excision over the past 20 years. Secondary or recurrent lesions and other spinal cord tumors were excluded. Surgical and follow-up details of these patients as well as those with associated spinal dysraphism were reviewed. Clinical and radiological follow-up revealed the recurrence in these inborn spinal cord disorders. Results A total of 73 patients were included retrospectively, having a mean age of 22.4 ± 13.3 years, and 41 (56.2%) cases fell in the first two decades of life. Twenty-four (32.9%) dermoid and 49 (67.1%) epidermoid cysts comprised the study population and 20 of them had associated spinal dysraphism. The distribution of SDECs was the most common in lumbosacral region ( n = 30) which was 10 times more common than in the sacral region ( n = 3). Bladder dysfunction 50 (68.5%) and pain 48 (65.7%) were the most common presenting complaints. During follow-up visits, 40/48 (83.3%) cases showed sensory improvement while 11/16 (68.7%) regained normal bowel function. There was no surgical mortality with recurrence seen in eight till the last follow-up. Conclusions The protracted clinical course of the spinal inclusion cysts mandates a long-term follow-up. The results of our study support the multisite closure model and attempt to provide a retrospective reflection of neural tube closure model in humans by using SDECs as the surrogate marker of neural tube closure defect.

Treading Toward Anterolateral Skull Base by Unlocking the Frontotemporal Dural Fold Along with Extradural Clinoidectomy: Translation from A Cadaver to Clinical Scenario.

BACKGROUND AND INTRODUCTION: Unlocking of the frontotemporal dural fold (FTDF) and extradural removal of the anterior clinoid process (EACP) are challenging but mandatory skills for micro-neurosurgeons. Despite the presence of an extensive body of literature on this subject, the translation of this cadaveric and 3D simulation to a real patient turns out to be a very demanding and difficult task. OBJECTIVE: This video is aimed to address the surgical nuances and major adjustments necessary in the unlocking of the FTDF and extradural ACP removal in an actual case for an early-career neurosurgeon. SURGICAL TECHNIQUE: A 40-year lady presented with features of acromegaly with radiological evidence of significant component of the tumor in the right cavernous sinus along with sellar suprasellar component. To achieve a good hormonal control, a complete tumor excision was required, which was achieved with FTDF and EACP removal. The cavernous sinus was approached through the Parkinson's triangle. RESULTS: The patient had uneventful recovery and good hormonal control at the 3-month follow-up. CONCLUSION: FTDF unlocking and EACP are elegant procedures and need to be learned by all neurosurgeons. This article will provide excellent teaching material for young neurosurgeons.

Modified Retromastoid Approach and Clipping of "High-Riding" VA-PICA Junction Aneurysm: An Operative Video.

BACKGROUND AND INTRODUCTION: Clipping an aneurysm on an elongated and tented V4 segment near the origin of the posterior inferior cerebellar artery (high-riding VA-PICA junction aneurysm) can be challenging. OBJECTIVE: We demonstrate the microsurgical clipping technique of such an aneurysm using a modified retromastoid approach (MRMA) and glossopharyngeal-cochlear triangle (GCT). SURGICAL TECHNIQUE: A 50-year-old female with a ruptured high-riding left VA-PICA junction aneurysm underwent an MRMA. Using segmental vessel isolation with proximal and distal temporary clips, this aneurysm was occluded through the GCT by applying a tandem clipping technique while preserving the PICA. RESULTS: The procedure was uneventful. Apart from transient ataxia, she recovered completely and maintains a good status at follow-up. CONCLUSION: In high-riding VA-PICA junction aneurysms, a conventional far lateral approach may create awkward viewing and working angles. An MRMA with a horizontal trajectory through the GCT may be a more appropriate strategy.

A Universal Craniometric Index for Establishing the Diagnosis of Basilar Invagination.

OBJECTIVE: The conventional criteria for defining the basilar invagination (BI) focus on the relationship of odontoid tip to basion and opisthion, landmarks that are intrinsically variable especially in presence of occipitalised atlas. A universal single reference line is proposed that helps in unequivocally establishing the diagnosis of BI, may be relevant in establishing both Goel types A and B BI, as well as in differentiating a 'very high' from 'regular' BI. METHODS: Study design - case-control study. In 268 patients (group I with BI [n = 89] including Goel type A BI [n = 66], Goel type B BI [n = 23], and group II controls [n = 179]), the perpendicular distance between odontoid tip and line subtended between posterior tip of hard palate-internal occipital protuberance (P-IOP line) was measured. Logistic regression analysis determined factors influencing the proposed parameter (p < 0.05). RESULTS: In patients with a 'very high' BI (n = 5), the odontoid tip intersected/or was above the P-IOP line. In patients with a 'regular' BI (n = 84), the odontoid tip was 6.56 ± 3.9mm below the P-IOP line; while in controls, this distance was 12.53 ± 4.28 mm (p < 0.01). In Goel type A BI, the distance was 7.01 ± 3.78 mm and in type B BI, it was 5.07 ± 4.19 mm (p = 0.004). Receiver-operating characteristic curve analysis identified 9.0 mm (8.92-9.15 mm) as the cut-point for diagnosing BI using the odontoid tip-P-IOP line distance as reference. CONCLUSION: The odontoid tip either intersecting the P-IOP line (very high BI) or being < 9 mm below the P-IOP line (Goel types A and B BI) is recommended as highly applicable criteria to establish the diagnosis of BI. This parameter may be useful in establishing the diagnosis in all varieties of BI.