"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.

Brain-stem hemangioblastomas: The seemingly innocuous lesion in a perilous location.

INTRODUCTION: Hemangioblastomas [75% sporadic, 25% with Von Hippel Lindau (VHL) disease] are highly vascular, benign lesions. The surgical nuances, management, and complication avoidance in brain-stem hemangioblastomas (BHs) have been studied. MATERIAL AND METHODS: Over 18 years, 27(mean age: 29 years; range 15-60 years) consecutive cases of BH underwent microsurgical excision. All patients were assessed clinico-radiologically for neurological deficits and screened for VHL disease. Outcome of the patients was based on Karnofsky Performance Status scale (KPS). RESULTS: 12 out of 19 (70.4%) patients with hydrocephalus underwent a cerebrospinal fluid (CSF) diversion procedure. Lower cranial nerve palsy was present in 10 (37%) patients and motor weakness in 13 (48%). The tumours [mean size 3.34 ± 1.06 cm, range: 1.4-5.5 cm; 11 solid, rest solid-cystic; 18 (66.7%) subpial and 9 (33.33%) intramedullary] were divided into four categories based on size: A: <2 cm (n = 5,18.5%); B: 2-3 cm (n = 10,37%); C: 3-4 cm (n = 6,22.2%); D: >4 cm (n = 6,22.2%). Their location was at posterior cervicomedullary junction (n = 12); pontomedullary junction (n = 7); pons (n = 3), medulla (n = 3) and ponto-mesencephalic region (n = 2). Multiple flow voids were seen in >50% patients with tumour >2 cm. 5 patients had syringomyelia; and, 8 had diffuse cervical cord expansion. Two patients with a large vascular tumour underwent preoperative embolization. Six patients had VHL disease; one underwent bilateral adrenalectomy for refractory hypertension; and, the another, nephrectomy for renal cell carcinoma. Twenty-six patients underwent a midline suboccipital craniectomy; and, 1 with a cerebellopontine angle tumour, a retromastoid craniectomy. 15 patients underwent total excision; 10 patients, near-total (<10% remaining) excision, and 2 patients, a subtotal (>10% remaining)) excision. Three patients (2 with VHL disease) expired due to exsanguinating hemorrhage, spreading venous thrombosis and aspiration pneumonitis, respectively. At follow-up visit (median: 25 ± interquartile range 2-56months), 17 patients had improved KPS, 4 remained in same status and 3 (recently operated, on tracheostomy) had worsened KPS. CONCLUSIONS: Significant improvement is achievable in neurological status in patients following successful extirpation of a brain-stem hemangioblastoma, despite a turbulent perioperative period. Leaving tumour capsule adherent to the brain-stem often helps in preserving brain-stem function. Postoperatively, the patients should be monitored for their respiratory and lower cranial nerve status to prevent aspiration pneumonitis.

Recurrent or symptomatic residual posterior fossa hemangioblastomas: how are they different from their primary counterparts?

BACKGROUND: Posterior fossa hemangioblastomas are WHO grade I benign lesions with a surprisingly high recurrence rate. This study determines the factors responsible for recurrence and the clinico-radiological and histopathological differences between primary (group A; n = 60) and recurrent/symptomatic residual (group B; n = 24) tumors. METHODS: Radiologically, tumors were differentiated into cystic, cystic with a mural nodule, solid-cystic/microcystic and solid. Surgery was undertaken via a midline or lateral suboccipital approach. Histopathology differentiated them into reticular, cellular or mixed subtypes. RESULTS: Truncal-appendicular ataxia in group A and von Hippel-Lindau (VHL) disease and raised intracranial pressure in group B were the predominant presentations. VHL patients in group B had a longer duration of symptoms (median 72 months) than those with non-VHL recurrences (median: 36 months). Multicentric mural nodules (n = 9/24, 37.50%, P = 0.0001) and bilateral cerebellar hemispheric involvement (n = 6/24, 25%, P = 0.0003) were exclusively seen in the preoperative radiology of group B tumors. Brainstem involvement was seen in the tumors of ten (16.67%) patients in group A and six (25.00%) patients in group B. One subset of patients required several resurgeries for repeated recurrences. Abnormal vascular proliferation and papillary projections into adjacent brain, and highly cellular stroma were unique histological features at recurrence. Total resection was achieved in 45 group A and 19 group B patients. The outcome based on the Karnofsky performance scale (KPS) was assessed at follow-up at 6 weeks (A: n = 60, B: n = 24): KPS0: A = 4, B = 1; KPS10-40 (dependent): A: 4, B = 5; KPS50-70 (independent for daily needs): A = 36, B = 16; KPS80-100 (fully independent): A = 16; B = 2. CONCLUSIONS: In recurrent/residual tumors, the radiological as well as histopathological features showed a distinctive change toward a more aggressive nature. Higher incidences of multiple mural nodules, bilateral spread, remote recurrence and VHL disease at preoperative radiology; as well as proliferative angioarchitecture, an irregular brain tumor interface and highly cellular stroma at histology were found in these patients compared to their primary counterparts.

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.

Surgery for superior hypophyseal artery aneurysms: A new classification and surgical considerations.

BACKGROUND: Superior hypophyseal artery (SHA) aneurysms form a unique subgroup of paraclinoid aneurysms having a propensity to grow to a large size in the suprasellar region resulting in compression of the optic nerve, chiasma, and/or tract. AIM: A new classification of SHA aneurysms is proposed that helps in identifying the surgical issues encountered during surgical clipping of these medially directed aneurysms located at different segments of the medial surface of the internal carotid artery (ICA). SETTINGS AND DESIGN: This descriptive study was conducted at a tertiary care university hospital. MATERIAL AND METHODS: In 14 patients operated for a SHA (mean age: 49.43 ± 11.28 years; presenting either with subarachnoid hemorrhage (n = 11; 78.57%) or mass effect (n = 3; 21.42%), 4 parameters having a bearing on surgery [a. size: (small <1 cm n = 5, large 1-2.5 cm n = 7, giant >2.5 cm n = 2); b. origin of SHA aneurysmal neck and direction of its fundus; c. relationship of the aneurysm to important neurovascular structures; and, d. whether the aneurysms were saccular or fusiform] were used to divide SHA aneurysms into 7 categories a. Antero-supero-medial (n = 2); b. Antero-infero-medial (n = 1); c. Supero-medial (n = 3); d. Infero-medial (n = 3); e. Postero-medial (n = 2); f. Fusiform (n = 1); and, g. Giant (n = 2). Modified Rankin Scale (MRS) score was utilized to assess outcome [favorable: mRS 0-2; unfavorable: mRS 3-6] at discharge and follow up. RESULTS: Modified Hunt and Hess grade at admission was 0 = 3; I = 3; II = 3; III = 2; IV = 3 (favorable mRS: 10; 71.42%; unfavorable mRS: 4; 28.57%); and, Fisher grade was I = 3; II = 6; III = 2; IV = 3. Twelve patients required anterior clinoid process drilling/carotid collar opening to facilitate optic nerve mobilization, for proximal ICA control, and to assess the proximal part of the neck of aneurysm for aneurysmal clipping (n = 13) or wrapping (n = 1). Fenestrated clip was applied in 5 patients. In the supero-medial group (antero-supero-medial, supero-medial, and postero-supero-medial), the aneurysmal fundus was found directly below the ipsilateral optic apparatus, elevating it; in the postero-supero-medial group, the fundus often lay in close proximity to A1 artery, Heubner's recurrent artery, ICA bifurcation, or dorsum sellae. Optic pathway, hypothalamic, and medial lenticulostriate perforators also required careful separation. Antero-infero-medial SHA aneurysm was hidden from view, embedded in the anterior wall of sella below tuberculum sellae. At a median follow-up of 17.5 ± 26.78 months (range: 8-84 months), 9 (64.28%) patients had a favorable mRS and 5 (35.71%) an unfavorable one. CONCLUSION: Systematically classifying SHA aneurysms and anticipating the surgical risk based upon their anatomical variations helps in achieving a good surgical outcome.

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.

Spinal neurenteric cysts: Associated developmental anomalies and rationale of surgical approaches.

BACKGROUND: Neurenteric cysts (NC) occur due to failure of separation of neurectoderm from endoderm at the 3rd week of embryogenesis. This study focuses on key clinico-radiological features of NCs, with emphasis on surgical nuances involved in resecting anteriorly placed NC, especially at the foramen magnum (FM). METHOD: Sixteen consecutive patients having a spinal NC were included. Their clinico-radiological status, surgical nuances and follow-up status were noted. RESULTS: The duration of spasticity/paraparesis/quadriparesis ranged from 15 days to 48 months. Twelve patients had an intradural extramedullary (IDEM; nine anterior and three anterolateral) cyst and four had an intramedullary (IM) cyst. Six of them had an anteriorly placed FM lesion (five IDEM and one IM). Amongst ten subaxial NCs, four were anterior, two antero-lateral and one postero-lateral; three were IM. Three patients had the characteristic stigmata of occult spinal dysraphism: two, a large mesenteric cyst, and one, a posterior mediastinal cyst. Excision was total in 13 patients. Subtotal excision of tumour capsule was performed for two recurrent cysts and an IM cyst. A far lateral approach was adopted for anteriorly placed FM lesions and posterior laminectomy for subaxial lesions. Histopathology revealed eight type A cysts, four type B cysts and four type C cysts. At follow-up (range, 8 months to 12 years; median, 60 ± 45.84 months), complete neurological recovery occurred in seven patients; six patients had persistent spasticity but only minor disability; two patients had difficulty in walking; and one patient with an anteriorly placed thoracic recurrent NC had sustained neurological deterioration. CONCLUSIONS: Surgical difficulties in addressing NCs are related to their anterior or IM location, presence of adhesions and inability to dissect the tumour capsule from the spinal cord due to fibrous or lipomatous connections. The associated developmental anomalies must be specifically sought and addressed.

Risk stratification of vertebral artery vulnerability during surgery for congenital atlanto-axial dislocation with or without an occipitalized atlas.

CONTEXT: Variability in dimensions and course of vertebral artery (VA) makes it vulnerable to injury during surgery for congenital atlanto-axial dislocation (AAD) with or without an occipitalized atlas. AIMS: This prospective study attempts to define anatomical variations that render VA at the craniovertebral junction (CVJ) vulnerable to injury during transoral decompression and posterior stabilization procedures; and, to propose a classification that helps in preoperative risk stratification. SETTINGS AND DESIGN: A prospective study. MATERIALS AND METHODS: 104 patients (65 with AAD; 39 controls) underwent a three-dimensional multiplanar computed tomographic angiogram to study anatomical variations in VA size, course, and anomalous medial deviation as well as in the type of axial isthmus and rotational deformity/tilt at the CVJ. The VA/foramen transversarium diameter; "stretched loop" sign of VA; and C1-2 facet joint angle were also assessed. STATISTICAL ANALYSIS USED: A medial VA deviation that brought it in close proximity to the trajectory of the surgical approach was evaluated (P ≤ 0.05 significant). RESULTS: An increased predisposition to VA injury was present in 23 (35.4%) patients (persistent first intersegmental artery [n = 20; 30%]; fenestrated VA [n = 1; 1.53%], and low-lying posterior inferior cerebellar artery [n = 2; 3.0%]) where VA crossed the C1-2 facet joint; 8 (12%) with an anomalous medial deviation; 12 (18%) with a high-riding VA at C2 and a narrow axial isthmus; and 13 (20%) with rotation/tilt at the CVJ. A normal score of 5 was obtained in 21 patients; and a score of 6-9 (that progressively indicated an increased vulnerability of VA to iatrogenic injury) in 44 patients. The "AAD with an occipitalized atlas" group was associated with a significant medial deviation of VA (right: P = 0.00 and left: P = 0.001). CONCLUSIONS: A preoperative detailed risk assessment of anatomical variations in the size and course of VA at the CVJ significantly reduces chances of its iatrogenic injury.

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.

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.

Prevalence and Clinical Course of Water and Electrolyte Disturbances Following Transsphenoidal Pituitary Adenoma Surgery in Immediate and Early Postoperative Period: A Prospective Observational Study.

Introduction: Transsphenoidal pituitary adenoma surgery (TSS) was commonly associated with water and electrolyte disturbances (WEDs) in the postoperative period, which could lead to prolonged hospital stay, readmission and is rarely life threatening. The present study aimed to investigate the prevalence and predictive factors of WEDs following TSS. Methods: Fifty-eight patients with pituitary adenoma were prospectively studied for the occurrence of WEDs. Patients were checked at 6 weeks postoperatively for persistence of diabetes insipidus and new-onset hormone deficiencies or recovery. Multivariate regression was applied to determine predictive factors for the occurrence of WEDs. Results: A total of 58 patients underwent TSS (median age: 43 years, 66% male). In the immediate postoperative period, 16 (27.6%) had transient diabetes insipidus (DI), two (3%) had transient DI followed by syndrome of inappropriate antidiuretic hormone (SIADH), five (8.6%) had isolated SIADH, five (8.6%) had persistent DI and only one patient had a triple-phase response. At 6 weeks, five (11%) patients continued to have persistent DI. In multivariate analysis, apoplexy and duration of surgery were predictive of DI occurrence. Recovery rate at 6 weeks was 11.1%, 13% and 9.3% for cortisol, thyroid and gonad axis, respectively. New-onset hormone deficiencies at 6 weeks were 5.6%, 5.6% and 7.4% for cortisol, thyroid and gonad axis, respectively. Conclusions: WEDs remain an important concern post-TSS. Timely follow-up should always be integral part of postoperative care for early diagnosis of new hormone deficiencies and avoiding unnecessary treatment in those with recovered axis.

Potential and Pitfalls of Postoperative Volumetric Assessment of Extent of Resection in High-Grade Glioma in Resource-Constrained Settings.

BACKGROUND: While literature suggests the need for routine postoperative volumetric estimation of the EOR and residual tumour volume (RTV) in all cases of gliomas, the utility and feasibility of this protocol in resource-constrained centers remain underinvestigated. OBJECTIVES: Our objective was to study the feasibility of volumetric EOR in routine neurosurgical practice and determine correlation with surgeons' intraoperative estimation of EOR. The secondary objective was to determine the survival impact of EOR and RTV on survival. METHODS AND MATERIALS: A prospective study of pathologically proven high-grade gliomas (WHO grades 3 and 4) in adults was conducted at a tertiary care center. Pre- and postoperative magnetic resonance imaging (MRI) was obtained for volumetric analysis using OsiriX software and manual segmentation. Overall survival and predictors were studied using Kaplan-Meier and Cox regression analysis. RESULTS: Postoperative volumetry was feasible in 31% patients (n = 25) of study eligible patients (n = 84). The median EOR, CE-PTV, and CE-RTV were 79.1%, 69.8 cm3, and 8.7 cm3, respectively. There was a poor correlation of surgeons' intraoperative impression and volumetric data (P = 0.359). Interestingly, the EOR was not significantly associated with the survival time (P = 0.920), while tumor grade, molecular profile, Ki 67 score, and postoperative functional status showed statistically significant impact. CONCLUSION: Logistic difficulties impede routine implementation of this protocol in developing countries. MRI volumetry is clearly more accurate than surgeons' intraoperative estimation of EOR. Notwithstanding the role of EOR in survival, our study reveals a perhaps bigger impact of tumor biology and postoperative functional status in this equation.

Pediatric Lumbosacral Spondylolisthesis: Overcoming the Disability!

BACKGROUND: Congenital spondylolisthesis is characterized by dysplasia of the facet joint or congenital defect in the pars. OBJECTIVE: Our study highlights the clinical and radiological profile, various treatment options, and outcomes in patients with pediatric congenital lumbar and lumbosacral spondylolisthesis. METHODS: A retrospective analysis and follow-up of 22 patients were conducted presented with radiological diagnosis of congenital lumbar/lumbosacral spondylolisthesis (2018-2021). RESULTS: Twenty patients (91%) had L5-S1 listhesis and two patients (9%) had L4-L5 listhesis. Six (27.3%) patients had low-grade listhesis (grades 1-2), 16 (72.7%) had high-grade listhesis (grades 3-5). Seventeen (77.3%) had S1, three (13.6%) had L5, and two (9%) had both L4-L5 radiculopathy. All patients had neurogenic claudication. One had an associated spina bifida occulta. Six (27.3%) patients underwent two-level fixation, and 16 (72.7%) underwent three-level fixation. Minimally Invasive Transforaminal Lumbar Interbody Fusion (MIS TLIF) was done in two patients. Revision of at least one screw was done in three patients. After one year of follow-up, all the patients had 75-100% relief in radicular pain and neurogenic claudication. The Oswestry Disability Index (ODI) score in preop for all patients was 41-60% and postoperatively they showed an improvement in ODI score (0-20). The postoperative low back pain score on the Numeric Rating Scale was 0-1 for all patients. CONCLUSION: Congenital lumbar spondylolisthesis usually presents with high-grade listhesis. Management of such cases is a surgical challenge but posterior decompression resulted in relief of pain in all patients. However, in situ fixation without reduction is also effective in selective cases where attempts to reduce the listhesis result in a decline in intraoperative neuromonitoring parameters.

Large and giant vestibular schwannomas: does cisterna magna hyperproteinorrhachia influence visual status?

BACKGROUND: Hyperproteinorrhachia associated with vestibular schwannomas (VSs) may influence visual status independent of the effect caused by raised intracranial pressure. The role of cisterna magna CSF protein levels (CMCP) in determining visual outcome in patients with large to giant vestibular schwannomas (VSs) was prospectively investigated. METHODS: The mean CMCP levels in VSs and control group; and, levels in VSs with or without visual deterioration were compared. Spearman's rank correlation coefficient tested for relationships between CMCP level with symptom duration and tumour volume (Kawamoto's method). Vision was regarded as normal when visual acuity was >6/18; and, deteriorated when it was between 6/18 and PL negative in the worse eye. Papilloedema (n = 26)/secondary optic atrophy (n = 6) and hydrocephalus (based on Evan's ratio, mild to moderate: n = 22; none: n = 18) were also recorded. The analysis of factors predicting diminished vision was done using logistic regression analysis (p < 0.05 significant). FINDINGS: There was a significant difference (p < 0.001) in mean CMCP levels between VS (456.3 SD 213.6 mg/dl) and control groups (96.3 SD 74.3 mg/dl). The mean CMCP levels in the VS group were also markedly higher than the ventricular mean protein levels. The CMCP levels in patients with visual diminution (<6/18 to PL negative; n = 23) was 561.4 SD 186.9 mg/dl and those without visual loss (n = 17) was 314.2 SD 160.8 mg/dl (p < 0.001). Their grade of visual diminution had a positive correlation with mean CMCP levels (p < 0.001). There was a negative correlation between total duration of symptoms and CMCP levels (p < 0.015). Logistic regression analysis using five independent factors (symptom duration, papilloedema/secondary optic atrophy, tumour volume, hydrocephalus and mean CMCP level) revealed that only CMCP level had a significant association with visual diminution. CONCLUSION: Elevated cisternal CSF proteins may play an important role in determining visual outcome in large to giant VSs. Ventricular CSF analysis is often unable confirm the presence of VS-associated cisternal hyperproteinorrhachia. High CMCP levels may influence decision-making while instituting a permanent CSF diversion for postoperative hydrocephalus or recalcitrant pseudomeningocoele.

Syndromic versus nonsyndromic atlantoaxial dislocation: do clinico-radiological differences have a bearing on management?

BACKGROUND: This prospective study attempts to study the clinico-radiological differences between patients with syndromic AAD (SAAD), non-syndromic AAD (NSAAD), and AAD with Klippel-Feil anomaly (AADKFA) that may impact management. METHODS: In 46 patients with AAD [SAAD (including Morquio, Down, Larson and Marshall syndrome and achondroplasia; n = 6); NSAAD(n = 20); and, AADKFS (n = 20)], myelopathy was graded as mild (n = 17, 37 %), moderate (15, 32.5 %) or severe (14, 30.5 %) based on Japanese Orthopaedic Association Score modified for Indian patients (mJOAS). Basilar invagination (BI), basal angle, odontoid hypoplasia, facet-joint angle, effective canal diameter, Ishihara curvature index, and angle of retroversion of odontoid and vertebral artery (VA) variations were also studied. STATISTICS: Clinico-radiological differences were assessed by Fisher's exact test, and mean craniometric values by Kruskal-Wallis test (p value ≤ 0.05 significant) RESULTS: Incidence of irreducible AAD in SAAD (n = 0), NSA AD (11.55 %) and AADKFS (n = 18.90 %) showed significant difference (p = 0.01). High incidence of kyphoscoliosis (83 %) and odontoid hypoplasia (83 %) in SAAD, and assimilated atlas and BI in NSAAD and AADKFA groups were found. In AADKFA, effective canal diameter was significantly reduced(p = 0.017) with increased Ishihara index and increased angle of odontoid retroversion; 61 % patients had VA variations. Thirty-five patients underwent single-stage transoral decompression with posterior fusion (for irreducible AAD) or direct posterior stabilization (for reducible AAD). Postoperative mJOAS evaluation often revealed persistent residual myelopathy despite clinical improvement. CONCLUSIONS: Myelopathy is induced by recurrent cord trauma due to reducible AAD in SAAD, and compromised cervicomedullary canal diameter in NSAAD and AADKFA. SAAD in children may be missed due to incomplete odontoid ossification or coexisting angular deformities. In AADKFA, decisions regarding vertebral levels to be included in posterior stabilization should take into consideration intact intervening motion segments and compensatory cervical hyperlordosis. Following VA injury, endovascular primary vessel occlusion/stenting across pseudoaneurysm preempts delayed rehemorrhage.

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.

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.

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.

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.