Use of Two Novel Dyes to Enhance Visualization of Cut Ends of the Vessel in Microvascular Anastomosis-An Experimental Study of 45 Rats.

BACKGROUND: Good visualization is a prerequisite for performing microvascular anastomosis. The most commonly used dye, methylene blue, has several limitations: it is washed off quickly and stains all the vessel layers. The objective of our study is to use 2 new novel dyes for improving visualization. METHODS: After ethical committee approval, 2 Dyes (2% cresyl violet, 1% eosin) were studied in 3 groups, 20 rats in each group and 5 rats in the combined group. End-to-side anastomosis was performed in the classic fashion in 45 rats. After venotomy, the dye was applied to the raw surface of the vessels and subsequently, anastomosis was performed. The improvement in visualization was judged by 3 blinded experts and nonexperts in 4 groups on a scale of 1-10. Scores were statistically analyzed. After 2 weeks, animals were re-explored to check the delayed patency, and segments were harvested for histopathologic analysis. RESULTS: The immediate and delayed patency rates were 100% (45/45) and 97% (33/34), respectively. In statistical analysis, the combined group (P = 0.005)was judged statistically significant because of the contrast in color. All the layers were stained by both dyes, staining lasted until the end of the surgery. Visibility of the cut ends was better in cresyl violet. All histopathologic findings suggested normal changes at the anastomotic site. CONCLUSIONS: This study showed that the use of these 2 dyes was not only feasible but highly efficacious. Even though all the layers were stained by both the dyes, the visibility of the cut ends was better. In both dyes, staining lasted until the end of surgery. To the best of our knowledge, this is the first study that has used these 2 novel dyes to improve visualization in microvascular anastomosis in an experimental setting.

Monomelic Amyotrophy/Hirayama Disease: Surgical Outcome in a Large Cohort of Indian Patients.

BACKGROUND: Hirayama disease (HD) is a cervical compressive myelopathy. Anterior cervical discectomy and fusion (ACDF) is identified as the best surgical approach. We evaluated surgical outcomes and factors influencing ACDF in HD. METHODS: Between 2015 and 2019, 126 patients with HD underwent ACDF. Contrast magnetic resonance imaging of the cervical spine in full flexion was performed. Clinical examination and preoperative/postoperative assessment of hand function using Fugl-Meyer assessment, Jebsen-Taylor hand function test, and handheld dynamometry were performed at 3-monthly intervals for 1 year. Surgical outcomes were assessed as per the Odom criteria and Hirayama outcome questionnaire. RESULTS: Age at onset and duration of illness were 12-31 years (mean, 18 ± 2.7) and 1-96 months (32.7 ± 24.4), respectively. All patients had progressive weakness and wasting of the affected limb. Cord atrophy was seen in 97.1%, with epidural detachment and engorgement of the posterior epidural venous plexus in all. All patients underwent ACDF. Of these patients, 54% had an excellent/good outcome and 39% had a satisfactory outcome as per the Odom scale at last follow-up (mean, 44.9 ± 16.5 months) after surgery. Handheld dynamometry showed improvement from preoperative values to 1 year follow-up. Duration of illness and age at onset had a negative correlation and the preoperative Fugl-Meyer score had a positive correlation with improvement. CONCLUSIONS: ACDF resulted in remarkable improvement or stabilization in neurologic deficits in many patients with HD. Because motor disability ensues over time, early surgical intervention during the progressive phase is advocated.

Neuroanatomical zones of human traumatic brain injury reveal significant differences in protein profile and protein oxidation: Implications for secondary injury events.

Traumatic brain injury (TBI) causes significant neurological deficits and long-term degenerative changes. Primary injury in TBI entails distinct neuroanatomical zones, i.e., contusion (Ct) and pericontusion (PC). Their dynamic expansion could contribute to unpredictable neurological deterioration in patients. Molecular characterization of these zones compared with away from contusion (AC) zone is invaluable for TBI management. Using proteomics-based approach, we were able to distinguish Ct, PC and AC zones in human TBI brains. Ct was associated with structural changes (blood-brain barrier (BBB) disruption, neuroinflammation, axonal injury, demyelination and ferroptosis), while PC was associated with initial events of secondary injury (glutamate excitotoxicity, glial activation, accumulation of cytoskeleton proteins, oxidative stress, endocytosis) and AC displayed mitochondrial dysfunction that could contribute to secondary injury events and trigger long-term degenerative changes. Phosphoproteome analysis in these zones revealed that certain differentially phosphorylated proteins synergistically contribute to the injury events along with the differentially expressed proteins. Non-synaptic mitochondria (ns-mito) was associated with relatively more differentially expressed proteins (DEPs) compared to synaptosomes (Syn), while the latter displayed increased protein oxidation including tryptophan (Trp) oxidation. Proteomic analysis of immunocaptured complex I (CI) from Syn revealed increased Trp oxidation in Ct > PC > AC (vs. control). Oxidized W272 in the ND1 subunit of CI, revealed local conformational changes in ND1 and the neighboring subunits, as indicated by molecular dynamics simulation (MDS). Taken together, neuroanatomical zones in TBI show distinct protein profile and protein oxidation representing different primary and secondary injury events with potential implications for TBI pathology and neurological status of the patients.

Correction: Comprehensive Normative Data for Objective Vestibular Tests.

[This corrects the article DOI: 10.7759/cureus.40080.].

Factors predicting recurrence in benign spinal nerve sheath tumors: A retrospective study of 457 patients from a single institution.

BACKGROUND: Benign Nerve sheath tumors (NST) comprise almost one-third of primary spinal tumours. The majority are sporadic. They have low rates of recurrence but an occasional recurrence may need re-surgery. The present study was designed to identify the variables that can predict the risk of their recurrence. METHODS: A retrospective chart review was done including all the histologically proven benign spinal NSTs operated between 2001 and 2019 in our institute. Demographic, operative and postoperative follow-up data were recorded. Recurrence was defined as local reappearance after definite surgical excision or symptomatic increase in size of a residual tumour on follow-up imaging studies. Statistical analysis was done to determine the significant variables associated with local recurrence. RESULTS: 457 patients with a median age of 38 years operated for 459 NSTs qualified for the study. The most frequent location of occurrence of tumours was found to be Low Cervical level (C3-C7 levels). Majority of Schwannoma were located intradurally while Neurofibroma were dumb-bell shaped and extradural. Most of the tumours had solid consistency. Post operatively, 7.7% patients developed complications. 7.8% tumours developed local recurrence after median period of 12 months. The patients developing recurrence were younger compared to nonrecurring tumors. On univariate analysis, male gender, Low cervical and Cervicothoracic junction location were associated with higher recurrence. On multivariate analysis, location at Cervicothoracic junction reached significance. CONCLUSION: Overall recurrence risk among all NST was 7.8% with a median progression free survival of 36 months. The location of tumour at cervicothoracic location was the significant risk factors for recurrence of tumour in our study.

Comprehensive Normative Data for Objective Vestibular Tests.

INTRODUCTION:  Vestibular dysfunction is a debilitating disorder frequently encountered in neurological and otological settings. The vestibular system is a complex network between peripheral and central mechanisms. This innate complexity of the vestibular system necessitates objective test procedures for evidence-based diagnostic formulations and intervention. Objective tests aid in the evaluation of both peripheral and central vestibular pathologies. Establishing and availability of comprehensive normative data for these objective tests is crucial for clinicians and researchers alike. MATERIALS AND METHODS: This is a prospective study involving 120 participants (both males and females) aged between 18 and 55 years. All participants were right-handed individuals and had no significant medical history. On pre-set protocols, cVEMP (cervical vestibular evoked myogenic potential), oVEMP (ocular vestibular evoked myogenic potential), vHIT (video head impulse test), and VNG (videonystagmography) were done. RESULTS: While all participants (n=120) underwent cVEMP, oVEMP, vHIT, saccade, smooth pursuit, and optokinetic tests, only 109 participants consented to the caloric test. Each test's mean, standard deviation, median, quartile, and third quartiles have been recorded. A right-left comparison yielded no significant difference on cVEMP, oVEMP, caloric test, smooth pursuit, and optokinetic test. However, few vHIT and saccade parameters did reveal significant differences. DISCUSSION: This study presents comprehensive normative data for cVEMP, oVEMP, vHIT, caloric test on VNG, and oculomotor tests (smooth pursuit, saccade, optokinetic) on VNG. The test results were in concordance with previously published data. The significant difference between the right and left sides in vHIT may be because of the monocular goggles used for the testing. CONCLUSION: This study brings out the normative data for various vestibular tests on individuals aged between 18-55 years. This information could aid both clinicians and researchers working in the field of vestibular science.

The Use of Retraction Sutures in End-To-Side Microvascular Anastomosis-A Novel Technical Innovation in Experimental Rat Femoral Model with Successful Use in STA-MCA Bypass in Moyamoya Disease.

BACKGROUND: A narrow working space, small diameters, and the tendency to collapse with clamps make cerebral microvascular anastomosis challenging. A retraction suture (RS) is a novel technique to keep the recipient vessel lumen open during the bypass. OBJECTIVE: To provide a step-by-step overview of RS for end-to-side (ES) microvascular anastomosis on rat femoral vessels and successful use for superficial temporal artery to middle cerebral artery (STA-MCA) bypass in Moyamoya disease patients. METHODS: A prospective experimental study with approval from the Institutional Animal Ethics Committee. Femoral vessels ES anastomoses were performed on Sprague Daley rats. The rat model used 3 types of RS (adventitial, luminal, and flap RSs). An ES-interrupted anastomosis was done. The rats were observed for an average period of 16.18 ± 5.65 days; the patency was assessed by reexploration. The immediate patency on the STA-MCA bypasses was confirmed with intraoperative indocyanine green angiography and micro-Doppler; delayed patency with magnetic resonance imaging and digital subtraction angiography after 3-6 months. RESULTS: In the rat model, 45 anastomoses were performed, 15 each using the 3 subtypes. The immediate patency was 100%. Delayed patency was 42/43 (97.67%), and 2 rats died during observation. In the clinical series, 59 STA-MCA bypasses were done in 44 patients (average age, 18.14 ± 11.09 years) using RS. The follow-up imaging was available for 41/59 patients. Both immediate patency and delayed patency (41/41 at 6 months) were 100%. CONCLUSION: The RS allows continuous visualization of the vessel lumen, reduces the handling of intimal edges, and avoids incorporating the back wall in sutures, thus improving anastomosis patency.

Minimally invasive foramen magnum decompression using tubular retractors (MIFT) for Chiari I malformations.

BACKGROUND: Chiari malformation type 1 has been traditionally treated with foramen magnum decompression and C1 arch excision with or without duroplasty depending on the surgeon's preference. Each of the various surgical modifications has its advantages and disadvantages. METHODS: We describe a minimally invasive tubular retractor-based approach to achieve bony decompression in these cases. We have had good results comparable to the open approach. CONCLUSIONS: Strict orientation to the midline using soft tissue landmarks in between the muscles and bony landmarks in the deeper planes is important to achieve good surgical results. Operative time decreases with expertise and is comparable to the open technique. Minimal blood loss and decreased hospital stay and an excellent cosmetic scar make this procedure more appealing.

Microneurosurgical Anatomic Study of the Horizontal Fissure of the Cerebellum.

OBJECTIVE: The horizontal fissure of the cerebellum, which is the largest and most prominent fissure, has received less interest from anatomists and neurosurgeons. Hence, the current study aims to provide comprehensive detail about the horizontal fissure and its anatomic and surgical relationship with deeper structures such as the dentate nucleus and middle cerebellar peduncle for the benefit of the neurosurgeon. METHODS: Ten whole formalin-fixed human cadaveric cerebellar hemispheres were obtained from human cadavers donated to the institution. Different parameters of the horizontal fissure were studied, such as length, depth (medial end, lateral end, and middle), sulcal and gyral variations (superficial and deep), and its close relationship, especially at depth, with the dentate nucleus and middle cerebellar peduncle. RESULTS: The total length of the horizontal fissure on the right and the left side was 64.3 ± 7.9 mm (range, 53-77 mm) and 65.6 ± 8.01 mm (range, 53-79 mm), respectively. The medial third of the horizontal fissure, with the fewest vessels, was the most suitable place to puncture or start the dissection of the horizontal fissure. The surface projection of the center of the posterior border of the dentate nucleus lies within 20-21 mm on either side of the posterior midline along the horizontal fissure and is only approximately 4 mm deep from the horizontal fissure. CONCLUSIONS: The anatomic measurements and relationships provided in this description of the horizontal fissure will serve as a tool for surgery selection and planning, as well as an aid to improve microneurosurgical techniques, with the final goal being better patient outcomes.

Histopathological Validation of Microvascular Anastomosis using Two-Throw Reef Knots - An Experimental Study.

Background: Knot configuration is an important but relatively neglected topic in microvascular anastomosis literature. Objective: To study the differences between end-to-end microvascular anastomosis performed with two-throw reef knots as compared to traditional three-throw knots in a rat femoral artery model at the histological level. Material and Methods: Sprague Dawley rats underwent end-to-end microvascular anastomosis of the right femoral artery (one-way-up method). The rats were divided into two groups: two-throw reef knots versus traditional three-throw knots. The patency was checked by the standard empty refill method. After 2 weeks, the rats underwent re-exploration. An anastomotic segment was sent for histological analysis. Histological alterations including luminal patency and changes in Tunica intima, Tunica media, and Tunica adventitia were compared between the two groups. Results: Twenty-nine rats were operated on by the senior author (17 by three-throw and 12 by two-throw reef knots). In the two-throw reef knot group versus the traditional three-throw knot group, the immediate patency rates were 100% versus 82.4%, and the delayed patency rates were 90.9% versus 62.5%, respectively. The histopathological patency rates were concordant with delayed patency rates. Subintimal proliferation and fibrosis were comparable in both groups. Adventitial granulomas were noted in all, irrespective of the knotting technique. Tunica media preservation rates for the two-throw reef knot versus the traditional three-throw knot group were 63.6% versus 0%. Five rats were operated by the beginner in the field, all by two-throw reef knots (to assess the safety of this new method in the hands of a beginner). Conclusion: Microvascular anastomosis performed with two-throw reef knots appears not only feasible but better in terms of anastomosis patency. Histological superiority in terms of Tunica media preservation further validates the technique.

Access to pain medicines and follow-up consultation after radiofrequency ablation for trigeminal neuralgia during the COVID-19 pandemic.

Background: In the recent coronavirus disease 2019 (COVID-19) pandemic, follow-up of patients with trigeminal neuralgia post radio-frequency ablation (RFA) of the Gasserian ganglion was restricted because of closure of pain clinic services (PCSs) at our institution, travel restrictions, and fear of contracting COVID-19 infection by hospital visit. Periodic follow-ups are a must in this group of patients. Because the access to pain medications and consultations remained restricted, we tried identifying the factors predisposing to these difficulties in patients. Methods: We had contacted patients telephonically, who underwent RFA at our institution in the past 5 years as the PCS had not re-started to follow up with in-person consultation. Demographics, socio-economic factors, clinical factors, literacy status, distance to the health care system, and current health status were noted. Collected data were analyzed descriptively, and correlations were calculated between the predictors for difficulty in follow-up to access the medications and consultations. Results: Out of 121 patients who underwent RFA in the past 5 years, 73 were accessible on phone. Of these, 42.46% (31/73) patients had difficulty in accessing either medications or consultation. The literacy status of the patient was the strongest predictor (0.044) with a negative correlation (-1.216). Difficulty in accessing PCS was associated with a poor health status (p-0.032) and higher pain scores (0.066). Conclusion: Along with the clinical factors, we have to overlook other factors in predicting difficulty to access PCS in trigeminal neuralgia patients post the RFA status. Difficulty in access to pain medicines and/or consultations was associated with a poor health status and higher pain scores.

Measure of Central Vestibular Compensation: A Review.

The central vestibular compensation reduces vestibular symptoms and helps individuals improve balance affected by vestibular dysfunction. The video head impulse test provides an opportunity to study central vestibular compensation objectively. This study aims to methodically present existing information about the video head impulse test as a measure to evaluate central vestibular compensation in patients with unilateral vestibular dysfunction. Literature review comprised 12 research articles selected based on pre-set criteria and timeline (January 2010 to June 2020). The findings indicate that the appropriate video head impulse test measures to evaluate central vestibular compensation after the occurrence of temporary unilateral vestibular dysfunction are the improvement in vestibulo-ocular reflex gain. And, for permanent unilateral vestibular dysfunction are reduction in catch-up saccades percentage, velocity, amplitude, latency, and Perez and Rey score.

Vertebral artery dissection in acute cervical spine trauma.

Objective: The aim of this study was to study mechanism, risk factors, and prognosis of patients with vertebral artery dissection (VAD) from acute cervical spine trauma (CST). Methods: A total of 149 consecutive patients were chosen from 2014 to 2019 from our institute data base, and their records were retrospectively studied. Morphology of fracture and subluxation were studied in detail with respect to the presence or absence of VAD. Results: Patients were divided in subsets of axial spine injury and subaxial spine injury. Subgroup and group analysis was performed and computerized tomography angiogram, MR angiogram and T1/T2 axial scans were studied to identify VAD, an incidence of 14.1% was found. Patients having infarcts in posterior circulation were also identified. Conclusion: There is a significant contribution of biomechanics of CST and evolution of VAD. This is an important consideration to prevent significant morbidity and mortality. Hence, a diagnostic algorithm which can be applied in any hospital setup is the need of the hour.

Abusive head trauma in India: imaging raises the curtain.

The purpose of the study was to identify children at our institute who possibly suffered abusive head trauma (AHT). A retrospective study of CT imaging of children between one month to three years of age between January 2013 and May 2021 was carried out at a dedicated neurocentre in Southern India. We identified 48 cases of possible AHT. The demographics, clinical features at presentation, imaging and fundus findings were analyzed. Imaging revealed subdural hemorrhage (SDH) in 42 and sub dural effusion (SDE) in 5 cases, one case had only hypoxia. The location of SDH was studied as was hypoxia underlying SDH, global hypoxia and ischemia. Cases of subarachnoid hemorrhage (SAH), parenchymal hematoma & intraventricular hemorrhage (IVH) were also noted. Skeletal survey, chest X-ray and CT spine were reviewed. AHT needs to be paid attention to in the Indian scenario. An extensive work up is required to substantiate the claim and to work on prevention & management of these cases subsequently.

Complex Chiari Malformation: Proposal of a New Set of Diagnostic Criteria and Outcomes After fusion Surgery.

BACKGROUND: The proposal of C1-C2 fusion as a better treatment option compared with foramen magnum decompression (FMD) for the treatment of Chiari 1 malformations has led to controversy. Although FMD is a time-tested treatment option, a group of patients exists who will benefit from C1-C2 fusion. We have proposed an objective system for defining complex Chiari malformations and studied the outcomes of fusion with decompression versus decompression alone for these patients. METHODS: A total of 26 patients with complex Chiari malformations were identified using our criteria (any 4 of 7 clinicoradiological parameters). Of the 26 patients, 13 had undergone C1-C2 fusion with FMD and 13 had undergone FMD alone. They had also undergone pre- and postoperative clinicoradiological evaluations, and the outcomes were assessed using the Chicago Chiari outcome score. RESULTS: Of the 13 patients in the fusion group, 12 (92.3%) showed improvement compared with only 6 of 13 patients (46.2%) in the nonfusion group using the Chicago Chiari outcome score, a statistically significant difference (P = 0.036, χ2 test). The mean hospital length of stay was longer for the fusion group (6.15 ± 1.46 days) than for the nonfusion group (4.38 ± 2.22 days; P = 0.02). CONCLUSIONS: We have proposed a novel set of criteria for defining complex Chiari malformations. Fusion with decompression provided better outcomes than decompression alone.

Toe-First Technique for End to Side Microvascular Anastomosis.

BACKGROUND: The use of the classic 2-ends anchoring technique is common in end-to side (ES) microvascular anastomosis. The literature on the toe-first (TF) technique is limited. In the current study we present the successful outcomes with the TF technique in ES anastomoses in rat femoral vessels model. METHODS: ES microvascular anastomosis with the tf technique was performed in the femoral vessels of 10 Sprague Dawley rats. Two-throw reef knot interrupted sutures were used in all cases. Individual parameters during the procedure were recorded for analysis. The immediate and delayed (cut open technique after 2 weeks) patencies were confirmed. An illustrative case showing the use of this technique in superficial temporal artery to middle cerebral artery bypass in a pediatric moyamoya disease case is included. RESULTS: The average suturing time was 40.14 ± 5.30 minutes, the procedures were completed with an average of 14.57 ± 1.90 sutures. The average time per suture was 2.78 ± 0.43 minutes. The immediate patency was 100% (10 of 10 cases). Two rats died of unknown cause in the observation period. The delayed patency was 100% in the remaining 8 cases (average observation: 29.6 days). CONCLUSIONS: The TF interrupted suture technique of ES microvascular anastomosis with 2-throw reef knots is feasible with excellent immediate and delayed patency rates. The distinct advantages of the TF are the continuous visualization of the recipient lumen during anastomoses, avoiding back-wall bites, and the ability to correct any discrepancy in the recipient-donor lumens during the procedure.