Placental vessel segmentation and registration in fetoscopy: Literature review and MICCAI FetReg2021 challenge findings.

Fetoscopy laser photocoagulation is a widely adopted procedure for treating Twin-to-Twin Transfusion Syndrome (TTTS). The procedure involves photocoagulation pathological anastomoses to restore a physiological blood exchange among twins. The procedure is particularly challenging, from the surgeon's side, due to the limited field of view, poor manoeuvrability of the fetoscope, poor visibility due to amniotic fluid turbidity, and variability in illumination. These challenges may lead to increased surgery time and incomplete ablation of pathological anastomoses, resulting in persistent TTTS. Computer-assisted intervention (CAI) can provide TTTS surgeons with decision support and context awareness by identifying key structures in the scene and expanding the fetoscopic field of view through video mosaicking. Research in this domain has been hampered by the lack of high-quality data to design, develop and test CAI algorithms. Through the Fetoscopic Placental Vessel Segmentation and Registration (FetReg2021) challenge, which was organized as part of the MICCAI2021 Endoscopic Vision (EndoVis) challenge, we released the first large-scale multi-center TTTS dataset for the development of generalized and robust semantic segmentation and video mosaicking algorithms with a focus on creating drift-free mosaics from long duration fetoscopy videos. For this challenge, we released a dataset of 2060 images, pixel-annotated for vessels, tool, fetus and background classes, from 18 in-vivo TTTS fetoscopy procedures and 18 short video clips of an average length of 411 frames for developing placental scene segmentation and frame registration for mosaicking techniques. Seven teams participated in this challenge and their model performance was assessed on an unseen test dataset of 658 pixel-annotated images from 6 fetoscopic procedures and 6 short clips. For the segmentation task, overall baseline performed was the top performing (aggregated mIoU of 0.6763) and was the best on the vessel class (mIoU of 0.5817) while team RREB was the best on the tool (mIoU of 0.6335) and fetus (mIoU of 0.5178) classes. For the registration task, overall the baseline performed better than team SANO with an overall mean 5-frame SSIM of 0.9348. Qualitatively, it was observed that team SANO performed better in planar scenarios, while baseline was better in non-planner scenarios. The detailed analysis showed that no single team outperformed on all 6 test fetoscopic videos. The challenge provided an opportunity to create generalized solutions for fetoscopic scene understanding and mosaicking. In this paper, we present the findings of the FetReg2021 challenge, alongside reporting a detailed literature review for CAI in TTTS fetoscopy. Through this challenge, its analysis and the release of multi-center fetoscopic data, we provide a benchmark for future research in this field.

CholecTriplet2022: Show me a tool and tell me the triplet - An endoscopic vision challenge for surgical action triplet detection.

Formalizing surgical activities as triplets of the used instruments, actions performed, and target anatomies is becoming a gold standard approach for surgical activity modeling. The benefit is that this formalization helps to obtain a more detailed understanding of tool-tissue interaction which can be used to develop better Artificial Intelligence assistance for image-guided surgery. Earlier efforts and the CholecTriplet challenge introduced in 2021 have put together techniques aimed at recognizing these triplets from surgical footage. Estimating also the spatial locations of the triplets would offer a more precise intraoperative context-aware decision support for computer-assisted intervention. This paper presents the CholecTriplet2022 challenge, which extends surgical action triplet modeling from recognition to detection. It includes weakly-supervised bounding box localization of every visible surgical instrument (or tool), as the key actors, and the modeling of each tool-activity in the form of triplet. The paper describes a baseline method and 10 new deep learning algorithms presented at the challenge to solve the task. It also provides thorough methodological comparisons of the methods, an in-depth analysis of the obtained results across multiple metrics, visual and procedural challenges; their significance, and useful insights for future research directions and applications in surgery.

Histogram of Oriented Gradients meet deep learning: A novel multi-task deep network for 2D surgical image semantic segmentation.

We present our novel deep multi-task learning method for medical image segmentation. Existing multi-task methods demand ground truth annotations for both the primary and auxiliary tasks. Contrary to it, we propose to generate the pseudo-labels of an auxiliary task in an unsupervised manner. To generate the pseudo-labels, we leverage Histogram of Oriented Gradients (HOGs), one of the most widely used and powerful hand-crafted features for detection. Together with the ground truth semantic segmentation masks for the primary task and pseudo-labels for the auxiliary task, we learn the parameters of the deep network to minimize the loss of both the primary task and the auxiliary task jointly. We employed our method on two powerful and widely used semantic segmentation networks: UNet and U2Net to train in a multi-task setup. To validate our hypothesis, we performed experiments on two different medical image segmentation data sets. From the extensive quantitative and qualitative results, we observe that our method consistently improves the performance compared to the counter-part method. Moreover, our method is the winner of FetReg Endovis Sub-challenge on Semantic Segmentation organised in conjunction with MICCAI 2021. Code and implementation details are available at:https://github.com/thetna/medical_image_segmentation.

Clinical characteristics and radiological domains among patients with recurrent strokes-a descriptive cross-sectional study from a tertiary care center in central Nepal.

BACKGROUND: Stroke is a significant global health hazard that ripples continuum multi-spectral effects to the patients as well their caretakers.   Methods: We studied 28 consecutive cohorts of patients with recurrent strokes managed in our centre within the last two years.  Results: The most common recurrence stroke pattern was of that of hemorrhagic to hemorrhagic subtype observed in 50% of the patients. The most common anatomical region of involvement was cortical - cortical seen in 39.28% of our cohorts. The surgical intervention was required in 17.85% whereas 42.85% of them were managed conservatively. Paradoxically, 39.28% of patients left against medical advice. The receiver operating curve (ROC) predicting mode of management was highest (area under the curve (AUC) =0.635) for compliance to therapy followed by stroke territory (AUC=0.578), age (AUC=0.457) and motor grading (AUC=0.374). The receiver operating curve (ROC) for influencing decision to leave against medical advice was highest (area under the curve (AUC) =0.861) for motor score followed by sex (AUC=0.701) and age (AUC=0.564). The analysis of variance (ANOVA) study pertaining to the mode of management was significantly connoted by the motor score and the stroke territory only. The ANOVA study pertaining to the decision to leave against medical advice was significantly governed by the motor score, stroke territory, and sex respectively. The multivariate analysis for variables governing mode of management was significant for motor score and the stroke territory only. The multivariate analysis for variables governing leave against medical advice was significant for sex, motor score and the stroke territory.  Conclusions: This study aims to appraise early dichotomization of high-risk patients for recurrent strokes to reduce the continuum of neurological events as well as to mitigate the financial aspects governing stroke care.

Education system of Nepal: impacts and future perspectives of COVID-19 pandemic.

The academic sectors are badly affected by the COVID-19 pandemic globally. The studies regarding the implications of COVID-19 in education in Nepal were minimal, thus, this paper aims to highlight the impacts of the pandemic on the education sector of Nepal. It is revealed that the Nepalese academia has been facing problems due to lack of adequate and appropriate sustainable infrastructure for the online system, including skilled human resources. In addition, limited internet facilities in remote and rural areas were the other challenging tasks for virtual academic activities. Therefore, the concerned stakeholders should provide necessary services and appropriate strategies for virtual means of the education system to compensate the repercussion caused by the pandemic. This study could be helpful to identify the critical needs emerged due to the pandemic at present and in future and also contribute to adopt appropriate policy for the revival of educational institutions.

Mini Craniotomy in the Management of Supratentorial Spontaneous Intracranial Hemorrhage: A Single-Center Outcome of the Minimally Invasive Treatment.

Hemorrhagic stroke accounts for a significant proportion of mortality and confers a poor quality of life with high dependency among survivors. Surgical evacuation of hematoma has the advantage of rapidly controlling the increased intracranial pressure, halting the ongoing herniation syndrome, and mitigating the secondary cascades of events mediated by the inflammatory and blood degradation products. The advantage is hindered by the concurrent insult to the healthy brain tissue while passing through the normal brain tissue. Therefore, minimally invasive approaches to evacuate the hematoma are employed, but the need for an expensive surgical armamentarium and the expert multidisciplinary team is the bottleneck for their application, particularly in low-income nations. We herein performed a study upon the role of mini craniotomy open surgical method of evacuating hematoma in selected patients with supratentorial intracerebral hemorrhage. We found a significant reduction in the surgery length, minimized risk of post-surgery complications, shortened intensive care unit stay, and reduced mortality compared to the full-fledged craniotomy and endoscopy-guided surgery. There is a need for a large-scale randomized multicenter prospective study to verify the advantages of minimally invasive approaches in the management of symptomatic supratentorial intracerebral hemorrhages.

Prospective observational research on the clinical profile and outcome analysis among a cohort of patients sustaining traumatic cervical spine and cord injury in a peripheral tertiary spine care centre in Nepal.

Background: In developing nations like Nepal, spinal cord injury has multispectral consequences for both the patient and their family members. It has the tendency to cripple and handicap the patients, and burn out their caretakers, both physically and mentally. Furthermore, the centralization of health care with only a handful of dedicated rehabilitation centers throughout Nepal further places patients into disarray. This study was carried out as a pilot study to determine the modes of injury, age groups affected, clinical profiles and patterns of injury sustained, as well as the efficacy of managing a subset of patients, who have sustained cervical spine and cord injuries. Methods: This was a prospective cohort study comprising of 163 patients enrolled over a period of three years that were managed in the spine unit of College of Medical Sciences, Bharatpur, Nepal. Results: Road traffic accidents were implicated in 51% of these patients. 65% of them were in the age group of 30-39 years. Traumatic subluxation occurred in 73 patients with maximum involvement of the C4/5 region (28.76%). Good outcome was seen in patients with ASIA 'C' and 'D' with 55% of patients showed improvement from 'C' to 'D' and 95% of patients showed improvement from 'D' to 'E' at 1 year follow up. The overall mortality in the patients undergoing operative interventions was only 1.98%. Conclusions: The prevalence of cervical spine injuries in the outreach area is still significant. The outcome of managing these patients, even in the context of a resource limited setup in a spine unit outside the capital city of a developing nation, can be as equally as effective and efficient compared to the outcome from a well-equipped and dedicated spine unit elsewhere.

Role of bromocriptine in multi-spectral manifestations of traumatic brain injury.

PURPOSE: Despite the prevalence and cost of traumatic brain injury related disabilities, there is paucity in the literature on modern approaches to pharmacotherapy. Medications may promote recovery by enhancing some neurological functions without impacting others. Herein we discussed the role of bromocriptine in neurorehabilitation for patients with traumatic brain injury. METHODS: A cohort comprising of 36 selective nonsurgical cases of traumatic brain injury in minimally conscious state were enrolled in the study. After hemodynamic stability, bromocriptine was given at paediatric dose of 3.75 mg/d and adult dose of 7.5 mg/d. It was administered through a naso-gastric (NG) feeding tube in the patients with minimally conscious state, then changed to oral route after proper swallowing and good gag reflex were ensured in the patient. The drug was slowly reduced over three weeks after neurological improvement in the patients. Positive result was determined by improved GCS score of 2 and motor power by at least 1 British Medical Council (BMC) motor score. Improvement of deficits was evaluated in terms of fluency of speech for aphasia, task switching, digit span double tasking and trail-making test for cognition and attention, and functional independence measure score for motor functioning and self-independence. RESULTS: Accelerated arousal was seen in 47.0% of cases (8/17) in 4-40 days. In 41.2% of cases (7/17), Glasgow outcome score (GOS) was improved to 4/5 in 90 days. Improvement in hemiparesis by at least 1 BMC score was seen in 55.6% of cases (5/9) in 40 days. Aphasia was improved in 80% of cases (4/5) in 7-30 days. Moderate improvement in cognitive impairment was seen in 66.7% of cases (2/3) in 14-20 days. Improvement in memory was observed in 50% of cases (1/2) in over 30 days. No cases were withdrawn from the study because of adverse reactions of the drug. There was no mortality in the study group. CONCLUSION: Bromocriptine improves neurological sequelae of traumatic brain injury as well as the overall outcome in the patients. If medication is given to promote recovery and treat its associated disabilities, clinicians should thoroughly outline the goals and closely monitor adverse effects.

Anterior single odontoid screw placement for type II odontoid fractures: our modified surgical technique and initial results in a cohort study of 15 patients.

Objective: Anterior odontoid screw fixation for type II odontoid fracture is the ideal management option. However in the context of unavailability of an O-arm or neuro-navigation and poor images from the available C-arm may be an obstacle to ideal trajectory and placement of the odontoid screw. We herein detail  our surgical technique so as to ensure a correct trajectory and subsequent good fusion in Type II odontoid fractures. This may be advantageous  in clinical set ups lacking state of the art facilities.  Methods and Results: In this cohort study we included 15 consecutive patients who underwent anterior odontoid screw placement. We routinely dissect the longus colli to completely visualize the entire width of C3 body. We then perform a median C2-C3 disectomy followed by creating a gutter in the superior end of C3 body. We then guide the Kirchsner (K) wire purchasing adequate anterior cortex of C2. Rest of the procedure follows the similar steps as described for odontoid screw placement. We achieved 100% correct trajectory and screw placement in our study. There were no instances of screw break out, pull out or nonunion. There was one patient mortality following myocardial infarction in our study. Conclusion: Preoperative imaging details, proper patient positioning, meticulous dissection, thorough anatomical knowledge and few added surgical nuances are the cornerstones in ideal odontoid screw placement. This may be pivotal in managing  patients in developing nations having rudimentary neurosurgical set up.

Exploring the Virchow-Robin spaces function: A unified theory of brain diseases.

BACKGROUND: Cerebrospinal fluid (CSF) transport across the central nervous system (CNS) is no longer believed to be on the conventional lines. The Virchow-Robin space (VRS) that facilitates CSF transport from the basal cisterns into the brain interstitial fluid (ISF) has gained interest in a whole new array of studies. Moreover, new line of evidence suggests that VRS may be involved in different pathological mechanisms of brain diseases. METHODS: Here, we review emerging studies proving the feasible role of VRS in sleep, Alzheimer's disease, chronic traumatic encephalopathy, and traumatic brain injury (TBI). RESULTS: In this study, we have outlined the possible role of VRS in different pathological conditions. CONCLUSION: The new insights into the physiology of the CSF circulation may have important clinical relevance for understanding the mechanisms underlying brain pathologies and their cure.

Case Report: Acute obstructive hydrocephalus associated with infratentorial extra-axial fluid collection following foramen magnum decompression and durotomy for Chiari malformation type I.

Acute obstructive hydrocephalus due to infratentorial extra-axial fluid collection (EAFC) is an extremely rare complication of foramen magnum decompression (FMD) and durotomy for Chiari malformation type I. Presence of infratentorial  EAFC invariably causes obstruction at the level of the fourth ventricle or aqueduct of Silvius, thereby indicating its definitive role in hydrocephalus. Pathogenesis of EAFC is said to be a local arachnoid tear as a result of durotomy, as this complication is not described in FMD without durotomy. Controversy exists in management. Usually EAFC is said to resolve with conservative management; so hydrocephalus doesn't require treatment. However, in this case EAFC was progressive and ventriculo-peritoneal shunting (VPS) was needed for managing progressive and symptomatic hydrocephalus.

A Rare Case Report on Suboccipital Region Benign Giant Osteoma.

Herein we report a rare case of a giant suboccipital osteoma in a 55-year-old woman presenting primarily due to cosmetic issue. We discuss the management algorithm taken in the patient, highlighting excision of a potentially curable bony tumor only after ruling out its extension to the ear cavity, mastoid ear cells, transverse sinus, and the intracranial compartment.

Role of computed tomography scores and findings to predict early death in patients with traumatic brain injury: A reappraisal in a major tertiary care hospital in Nepal.

BACKGROUND: Glasgow Coma Scale has been a long sought model to classify patients with head injury. However, the major limitation of the score is its assessment in the patients who are either sedated or under the influence of drugs or intubated for airway protection. The rational approach for prognostication of such patients is the utility of scoring system based on the morphological criteria based on radiological imaging. Among the current armamentarium, a scoring system based on computed tomography (CT) imaging holds the greatest promise in conquering our conquest for the same. METHODS: We included a total of 634 consecutive neurosurgical trauma patients in this series, who presented with mild-to-severe traumatic brain injury (TBI) from January 2013 to April 2014 at a tertiary care center in rural Nepal. All pertinent medical records (including all available imaging studies) were reviewed by the neurosurgical consultant and the radiologist on call. Patients' worst CT image scores and their outcome at 30 days were assessed and recorded. We then assessed their independent performance in predicting the mortality and also tried to seek the individual variables that had significant interplay for determining the same. RESULTS: Both imaging score (Marshall) and clinical score (Rotterdam) can be used to reliably predict mortality in patients with acute TBI with high prognostic accuracy. Other specific CT characteristics that can be used to predict early mortality are traumatic subarachnoid hemorrhage, midline shift, and status of the peri-mesencephalic cisterns. CONCLUSION: We demonstrated in this cohort that though the Marshall score has the high predictive power to determine the mortality, better discrimination could be sought through the application of the Rotterdam score that encompasses various individual CT parameters. We thereby recommend the use of such comprehensive prognostic model so as to augment our predictive power for properly dichotomizing the prognosis of the patients with TBI. In the future, it will therefore be important to develop prognostic models that are applicable for the majority of patients in the world they live in, and not just a privileged few who can use resources not necessarily representative of their societal environment.

Unusual Finding of Vertebral Artery Fenestration in Spontaneous Deep Nuclear Hemorrhage.

Vertebral artery fenestration is accidentally detected during angiography or autopsy. Spontaneous deep nuclear hemorrhage in association with vertebral artery fenestration is a very unusual finding in angiography. Such an unusual finding has not been reported in the English literature. Here, we report two cases of spontaneous deep nuclear hemorrhage that presented with features of raised intracranial pressure. Computed tomography revealed a deep nuclear acute bleed in both cases. Digital subtraction angiographic findings were normal other than the presence of a long segment vertebral artery fenestration. Both extracranial and intracranial variations were detected. Although the existence of vascular fenestration in the vertebrobasilar system produces less clinical importance, it may influence the management of cervical and intracranial pathologies to avoid iatrogenic injury.

Conquering the odds: Cirsoid aneurysm with holocranial feeders-staged embolization, excision and grafting.

Arteriovenous malformation (AVM) of the scalp is an uncommon entity. Its management is difficult because of its high shunt flow, complex vascular anatomy, and possible cosmetic complications. The etiology of scalp AVMs that is, cirsoid aneurysm may be spontaneous or traumatic. Clinical symptoms frequently include pulsatile mass, headache, local pain, tinnitus; and less frequently, hemorrhage and necrosis. Selective angiography is the most common diagnosis method. Surgical excision is especially effective in AVMs and the most frequently used treatment method. Here, we present one such case where staged embolization, excision, and subsequent grafting was done.

Traumatic Cervical Spondyloptosis in a Neurologically Stable Patient: A Therapeutic Challenge.

This is a case report of a neurologically intact patient following posttraumatic cervical spondyloptosis. We discuss the disease, management protocol and some surgical nuances to prevent any damage to the cord during different stages of its treatment.

Case Report: Primary dural based diffuse large B-Cell lymphoma in a 14 year-old boy.

Primary dural lymphoma is a subentity of primary leptomeningeal lymphoma which represents 0.1% of all non-Hodgkin's lymphomas. Only five cases have been reported so far. We report a very rare case of primary dural-based lymphoma in a 14 year-old boy presenting with mass effect. The patient was managed with excision of the lesion and removal of the involved bone. Post-operatively, the patient showed good recovery. He was then referred to the oncology unit for further chemo- and radiation therapy. A high index of suspicion should therefore be kept in order to diagnose the condition in a timely fashion and then plan for appropriate management since diffuse large cell lymphoma has a relatively benign clinical prognosis.

Case Report: A case report of dry tap during ventriculostomy.

Pneumocephalus following ventriculoperitoneal (VP) shunt insertion is an exceptionally rare occurrence. We report such an event after attempting ventricular puncture (ventriculostomy) for VP shunt insertion and then discuss the management of the same. Dry tap can lead to multiple attempts for ventriculostomy with the associated added risks of complications, as well as complicating the subsequent management. In addition, there is an increased risk of tension pneumocephalus, seizure and shunt failure due to a blockage by air bubbles. Our patient presented with features of raised intracranial pressure two months following craniotomy and evacuation of traumatic subdural hematoma. External ventricular puncture revealed egress of CSF under pressure. Upon attempting VP shunting for post-traumatic hydrocephalus, we experienced dry tap during ventricular puncture that complicated further management. We placed the proximal shunt in the presumed location of the foramen of Monro of ipsilateral frontal horn of lateral ventricle and did not remove the external ventricular drain. Post-operative CT scan revealed pneumoventriculi as the cause for the dry tap during ventricular puncture. Patient was managed with 100% oxygen. He showed gradual improvement and was later discharged. This case shows that variations in the procedure, including head down positioning, adequate cruciate dural incision prior to cortex puncture, and avoiding excessive egress of CSF can help to prevent such complications.