Deformable 3D-2D Registration of Known Components for Image Guidance in Spine Surgery.

A 3D-2D image registration method is reported for guiding the placement of surgical devices (e.g., K-wires). The solution registers preoperative CT (and planning data therein) to intraoperative radiographs and computes the pose, shape, and deformation parameters of devices (termed "components") known to be in the radiographic scene. The deformable known-component registration (dKC-Reg) method was applied in experiments emulating spine surgery to register devices (K-wires and spinal fixation rods) undergoing realistic deformation. A two-stage registration process (i) resolves patient pose from individual radiographs and (ii) registers components represented as polygonal meshes based on a B-spline model. The registration result can be visualized as overlay of the component in CT analogous to surgical navigation but without conventional trackers or fiducials. Target registration error in the tip and orientation of deformable K-wires was (1.5±0.9)mm and 0.6∘±0.2∘, respectively. For spinal fixation rods, the registered components achieved Hausdorff distance of 3.4 mm. Future work includes testing in cadaver and clinical data and extension to more generalized deformation and component models.

Work-related musculoskeletal pain and discomfort in laparoscopic surgeons: an international multispecialty survey.

INTRODUCTION: As laparoscopic surgery is used more widely across the globe and within multiple surgical specialties the potential impact on surgeons is yet to be fully quantified. Maintenance of uncomfortable body positions may lead to work-related musculoskeletal disorders (WMSD) in surgeons, with potential knock-on effects. METHODS: An international open online survey of multispecialty laparoscopic surgeons was carried out, designed and reported in accordance with the CHERRIES checklist for internet e-survey research. There was no paid advertising and no incentives offered. RESULTS: A total of 259 surgeons from 9 specialties and 32 countries answered the survey, with 90% reporting pain attributable to performing laparoscopic surgery. All training grades were represented. Longer average operative duration and a greater number of years in practice were both associated with a significantly higher prevalence of pain. Surgeons with a pre-existing injury were significantly more likely to report pain than those without. Twenty per cent of surgeons would consider early retirement owing to pain. CONCLUSIONS: The impact on surgeons of performing laparoscopic surgery is significant, even given the limitations of an open survey. Innovations such as robotic surgery and improved ergonomic education may reduce the incidence of WMSD in surgeons, to mitigate both the personal effects on surgeons and the wider effect on the future surgical workforce.

A systematic review of point-of-care abdominal ultrasound scans performed by general surgeons in paediatric patients.

BACKGROUND/PURPOSE: Bedside point-of-care ultrasound scans are a cheap, quick and safe diagnostic tool. There is increasing evidence for the use of point-of-care surgeon-performed ultrasound scans in adults, however there are fewer studies of its use in children. This systematic review aims to provide an up-to-date summary of the evidence behind surgeon-performed ultrasound scans in paediatric surgery. METHODS: The PubMed database was used to conduct this systematic review between the dates 1 Jan 1980 to 1 June 2020 (last search: 1 June 2020). Seven primary research studies were included in this review. RESULTS: There is good evidence for the use of ultrasound scans in appendicitis and hypertrophic pyloric stenosis. Training times are easily achievable and transferable within a surgical department. CONCLUSIONS: Although the use of surgeon-performed bedside ultrasound scans has been described in appendicitis and hypertrophic pyloric stenosis, more research is required to embed this into clinical practice, particularly in low volume centres such as district general hospitals. A robust training programme is also recommended to incorporate ultrasound scans into clinical practice.

Liver Resection for Giant Hepatic Cavernous Hemangioma.

Liver hemangiomas are common. Giant liver hemangiomas are rare and symptomatic patients require treatment. Surgery is the curative procedure. Other options such as intra-arterial embolization may be used to decrease the volume and bleeding of these lesions. Three cases of giant liver hemangioma were treated with liver resection, one with left lateral hepatectomy and two with right lateral hepatectomy. All patients had made an uneventful recovery with no recurrence at 3-year follow-up. Most hemangiomas are small, asymptomatic, and do not require any treatment. Liver resection is a safe and effective treatment for giant hemangiomas.

Super protective anti-bacterial coating development with silica-titania nano core-shells.

In the present study, we have developed an anti-bacterial as well as mechanically-strengthened super protective coating material, which can be used as a marine antifouling paint. In this research, silica, titania and silica-titania core-shell nanoparticles were individually prepared via sol-gel and peptization processes. The idea behind the synthesis of core-shell nanoparticles was to utilize the mechanical strength of silica and the antimicrobial property of TiO2 together. These nanoparticles were characterized via dynamic light scattering, UV-Visible spectroscopy, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Coating formulations were developed with two types of model binders, i.e., solvent-based polyurethane and water-based poly-acrylic, containing all nanoparticles individually at various concentrations for a better comparative study. These coating formulations were applied onto mild steel for anti-bacterial testing that was performed against Escherichia coli and Bacillus. The nanoparticle concentration was varied from 1% (wt) to 6% (wt). The best anti-bacterial result was obtained with 4% (wt) of silica-titania core-shell nanoparticles prepared via the peptization process among all the nanoparticles. The scratch testing was performed successfully using an Erichsen scratch tester; the formulated PU coating passed up-to 20 N load with good adhesion, impact resistance, flexibility and has shown satisfactory anti-corrosion performance.

Identifying the optimal developmental age of human pluripotent stem cell-derived midbrain dopaminergic progenitors for transplantation in a rodent model of Parkinson's disease.

Donor cell age can have a significant impact on transplantation outcomes. Despite the rapid advancement of human pluripotent stem cell (hPSC)-derived dopaminergic (DA) progenitors to the clinic for transplantation into Parkinson's Disease (PD), surprisingly limited data exists regarding the influence of cellular age on neural graft survival, composition, and integration. Here we examined the impact of transplanting ventral midbrain (VM) progenitors at varying days of differentiation (from day 13-30) into a rodent PD model, comparing two hPSC lines (an embryonic and an induced pluripotent cell line, hESC and hiPSC, respectively). Both hPSC lines expressed GFP under the promoter PITX3 enabling specific tracking of graft-derived DA neurons. Post-mortem analysis at 6 months revealed larger grafts from Day19 (D19), D22 and D25 progenitors, yet contained a higher proportion of non-DA and poorly specified (FOXA2-) cells. While D13 and D30 progenitors yielded smaller grafts. D13-derived grafts had the highest DA neuron proportion and proportionally more GIRK2+ DA neurons, the subpopulation critical for motor function. These younger progenitor grafts maintained their capacity to innervate developmentally relevant DA targets, with increased innervation capacity per DA neuron, collectively resulting in restoration of motor deficits with equal or greater proficiency than older donor cells. While donor age effects were reproducible for a given hPSC line and trends were similar between the two hPSC lines, grafts of D13 hiPSC-derived progenitors showed a 6-fold greater density of DA neurons compared to D13 hESC-derived grafts, highlighting between-line variability. These findings show that hPSC-derived VM donor age has a direct impact on graft survival, composition and maturation, and that careful assessment, on a line-to-line basis is required prior to translation.

Incidence of Deep Venous Thrombosis and Sickle Cell Disease in Patients Undergoing Spinal Surgery in South Gujarat, India: A Prospective Observational Study.

Introduction: Our objective of this study was to assess the incidence of Deep Venous Thrombosis in patients including those with sickle cell disease who underwent spine surgery, and also to determine the association of Sickle Cell Disease as a clinical predictor for Deep Venous Thrombosis in spinal surgery patients. Materials and methods: All patients who underwent spinal surgery from January 2016 to October 2016 were included in this study. Detailed history, demographic data, physical findings, pre-operative haematological and radiological investigations were documented. All the patients underwent daily clinical evaluation for clinical signs of Deep Venous Thrombosis and also underwent a post-operative venous Doppler and D-dimer test. Results: Seventy-nine consecutive patients were included in the study with the mean age of 41 years. All patients had normal venous Doppler pre-operatively. A total of 2.5% patients had deep vein thrombosis in bilateral lower limbs while 2 patients (2.5%) had evidence of venous stasis but no thrombosis on Doppler ultrasound done post-operatively. Nine patients (11.4%) were sickle cell positive from which 4 patients showed evidence of Deep Venous Thrombosis or Venous Stasis. D-dimer was positive in 5 (8.3%) patients which included 4 patients with Sickle Cell Disease. Conclusion: This study concludes that Sickle Cell Disease is a risk factor for developing Deep Venous Thrombosis in patients undergoing spinal surgery. The study also concludes the effectiveness of mechanical prophylaxis in preventing Deep Venous Thrombosis and recommends pharmacological prophylaxis after assessing the risk profile or positive D-dimer test.

Effectiveness of two tobacco cessation methods among TB patients.

BACKGROUND: Tobacco and TB are the world´s two greatest public health problems. Exposure to tobacco has been shown to be associated with higher risk of acquiring TB and adverse outcomes such as relapse and TB mortality.OBJECTIVE: To assess and compare self-reported tobacco quit status and biochemically verified cotinine levels among TB patients at different time intervals among two study groups.METHODS: A cluster, randomised controlled trial was conducted on TB patients attending DOTS centres in Delhi, India, who reported using tobacco in any form. Participants were assigned into one of two treatment groups. Centres were randomly assigned to two intervention groups: 1) integrated intervention using behavioural counselling with nicotine replacement therapy (NRT) gum, and 2) intervention using behavioural counselling alone (50 each in intervention and control group). The subjects were followed at Week 1, Month 1, Month 3 and Month 6 for tobacco cessation.RESULTS: At the end of 6 months, patients who received the integrated intervention had significantly higher rate of success in quitting tobacco than those who received the conventional TB treatment alone (78.7% vs. 57.8%; P < 0.03).CONCLUSION: DOTS with tobacco use dependence treatment was successful in our study in helping TB patients to quit tobacco dependence and should therefore be offered to every tobacco user.

Mental health and academic outcomes over the first year at university in international compared to domestic Canadian students.

OBJECTIVE: To compare risk factors and associated mental health and academic outcomes between international and domestic students. PARTICIPANTS: Canadian university undergraduate students. METHODS: Electronic surveys were completed at university entry and the end of first year. Surveys assessed demographics, risk factors, symptoms of mental disorders, and access to support. Academic outcomes were obtained from university databases. RESULTS: International students had comparable or lower rates of clinically significant anxiety, depression, and insomnia. Domestic female students reported the highest screening rates for common mental disorders. However, international students were more likely to report having attempted suicide. International students felt less connected to the university community and had lower academic performance. Psychosocial risk factor profiles and proportions accessing mental health services were similar. CONCLUSIONS: The scope of mental health need appears more similar than different between international and domestic students; however, international students may benefit from targeted academic and social support initiatives.

Development and Validation of a Risk-Adapted Scoring Model for Metachronous Upper Tract Urothelial Carcinoma following Radical Cystectomy.

PURPOSE: The incidence and risk factors for metachronous upper tract urothelial carcinoma (UTUC) following radical cystectomy (RC) remain incompletely defined, which has limited the ability to individualize postoperative surveillance. MATERIALS AND METHODS: A retrospective review of 2 institutional registries was performed to identify patients undergoing RC for urothelial carcinoma. Multivariable Cox proportional hazard models for metachronous post-RC UTUC were developed in one institutional data set and validated in the second institutional data set. A post-RC UTUC risk score was then developed from these models. RESULTS: A total of 3,170 RC patients were included from the training cohort and 959 RC patients from the validation cohort. At a median followup after RC of 4.6 years (IQR 2.1-8.7), 167 patients were diagnosed with UTUC. On multivariable analysis in the training cohort, risk factors for metachronous UTUC were the presence of positive urothelial margin (HR 2.60, p <0.01), history of bacillus Calmette-Guérin treatment prior to RC (HR 2.20, p <0.01), carcinoma in situ at RC (HR 2.01, p <0.01) and pre-RC hydronephrosis (HR 1.48, p=0.04). These factors had similar discriminative capacity in the training and validation cohorts (C-statistic 0.71 and 0.73, respectively). A UTUC risk score was developed with these variables which stratified patients into low (0 points), intermediate (1-3 points), and high risk (4+ points) for post-RC UTUC, with respective 5-year UTUC-free survivals of 99%, 96%, 89% in the training cohort and 98%, 96%, and 91% in the validation cohort. CONCLUSIONS: We developed and validated a risk score for post-RC UTUC that may optimize UTUC surveillance protocols after RC.

Soft-Tissue Imaging in Low-Dose, C-Arm Cone-Beam CT Using Statistical Image Reconstruction.

C-arm cone-beam CT (CBCT) is an emerging tool for intraoperative imaging, but current embodiments exhibit modest soft-tissue imaging capability and are largely constrained to high-contrast imaging tasks. A major advance in image quality is facilitated by statistical iterative reconstruction techniques. This work adapts a general penalized likelihood (PL) reconstruction approach with variable penalties and regularization to C-arm CBCT and investigates performance in imaging of large (>10 mm), low-contrast (<100 HU) tasks pertinent to soft-tissue surgical guidance. Experiments involved a mobile C-arm for CBCT with phantoms and cadavers presenting soft-tissue structures imaged using 3D filtered backprojection (FBP), quadratic, and non-quadratic PL reconstruction. Polyethylene phantoms with various tissue-equivalent inserts were used to quantity contrast-to-noise / resolution tradeoffs in low-contrast (~40 HU) structures, and the optimal reconstruction parameters were translated to imaging an anthropomorphic head phantom with low-contrasts targets and a cadaveric torso. Statistical reconstruction - especially non-quadratic PL variants - boosted soft-tissue image quality through reduction of noise and artifacts (e.g., a ~2-4 fold increase in contrast-to-noise ratio (CNR) at equivalent spatial resolution). For tasks relating to large, low-contrast tissues, even greater gains were possible using non-quadratic penalties and strong regularization that sacrificed spatial resolution in a manner still consistent with the imaging task. The advances in image quality offered by statistical reconstruction present promise and new challenges for interventional imaging, with high-speed computing facilitating realistic application. Careful investigation of performance relative to specific imaging tasks permits knowledgeable application of such techniques in a manner that overcomes conventional tradeoffs in noise, resolution, and dose and could extend application of CBCT-capable C-arms to soft-tissue interventions in neurosurgery as well as thoracic and abdominal interventions.

Patient-Specific Minimum-Dose Imaging Protocols for Statistical Image Reconstruction in C-arm Cone-Beam CT Using Correlated Noise Injection.

PURPOSE: A new method for accurately portraying the impact of low-dose imaging techniques in C-arm cone-beam CT (CBCT) is presented and validated, allowing identification of minimum-dose protocols suitable to a given imaging task on a patient-specific basis in scenarios that require repeat intraoperative scans. METHOD: To accurately simulate lower-dose techniques and account for object-dependent noise levels (x-ray quantum noise and detector electronics noise) and correlations (detector blur), noise of the proper magnitude and correlation was injected into the projections from an initial CBCT acquired at the beginning of a procedure. The resulting noisy projections were then reconstructed to yield low-dose preview (LDP) images that accurately depict the image quality at any level of reduced dose in both filtered backprojection and statistical image reconstruction. Validation studies were conducted on a mobile C-arm, with the noise injection method applied to images of an anthropomorphic head phantom and cadaveric torso across a range of lower-dose techniques. RESULTS: Comparison of preview and real CBCT images across a full range of techniques demonstrated accurate noise magnitude (within ~5%) and correlation (matching noise-power spectrum, NPS). Other image quality characteristics (e.g., spatial resolution, contrast, and artifacts associated with beam hardening and scatter) were also realistically presented at all levels of dose and across reconstruction methods, including statistical reconstruction. CONCLUSION: Generating low-dose preview images for a broad range of protocols gives a useful method to select minimum-dose techniques that accounts for complex factors of imaging task, patient-specific anatomy, and observer preference. The ability to accurately simulate the influence of low-dose acquisition in statistical reconstruction provides an especially valuable means of identifying low-dose limits in a manner that does not rely on a model for the nonlinear reconstruction process or a model of observer performance.

Predictors of Poor Functional Status in Adult Fontan Patients Living at Moderate Altitude.

Patients who have undergone Fontan palliation have reduced exercise tolerance measured by maximal oxygen consumption (VO2 max). Declining exercise capacity is associated with increased morbidity and mortality. The impact of hemodynamics and other variables on this population's functional status is not well understood. This study sought to identify variables that predict low VO2 max in Fontan patients living at moderate altitude (5,000-8,000 feet). We performed a retrospective cohort study of 44 adult Fontan patients living at moderate altitude who had undergone cardiopulmonary exercise testing (CPET) and cardiac catheterization. We evaluated hemodynamic parameters measured during catheterization, imaging results, and laboratory studies for correlation with VO2 max measured during CPET. Our study cohort (median age 30 years, 52% female) had exercise impairment with mean VO2 max of 21.6 mL/kg/min. Higher trans-pulmonary gradient (TPG) (p < 0.001) and mean pulmonary artery (PA) pressure (p = 0.013) were predictors of lower maximal and submaximal VO2. Higher BNP values correlated with lower VO2 max (p = 0.01). Platelet count, GGT, albumin, and pulmonary vasodilator therapy did not correlate with VO2 max. None of the studied variables were associated with higher minute ventilation to peak carbon dioxide production (VE/VCO2 slope) or change in VO2 max over time. In conclusion, higher TPG and mean PA pressure predicted lower exercise tolerance amongst our cohort of adult Fontan patients living at moderate altitude. Future studies are needed to determine if these clinical variables represent viable therapeutic targets that could result in improved exercise tolerance and outcomes in patients with Fontan circulation.

A case of Infective Native (Abdominal) Aortic Aneurysm Caused by Streptococcus Agalactiae: An Updated Literature Review Based on New Nomenclature.

The management of abdominal aortic aneurysms (AAA) has evolved significantly with the advent of endovascular strategies. Thus, there has been a decline in the number of open AAA repairs once an endovascular option is available. There have also been reports of successful endovascular management of infective native aortic aneurysms (INAA)1, previously called mycotic aneurysms2. The rarity of this condition makes its management a challenging one as there are no standard guidelines. The European Society of Vascular Surgery has suggested that the nomenclature be changed from mycotic aneurysms as this can be misleading to standardise reporting1. The authors' present a case of a 67-year old male who presented during the peak of the Corona Virus pandemic with constitutional gastrointestinal symptoms. He was subsequently diagnosed with an INAA and successfully managed with open Neo-Aorto Iliac System reconstruction with a homograft3. The report highlights various strategies used in the surgical approach and their benefits in the management of INAA. Furthermore, a literature review of Streptococcus (Streptococcus agalactiae) species as a rare cause of INAA and how these cases were managed are also highlighted.

A systematic review of point-of-care abdominal ultrasound scans performed by general surgeons.

BACKGROUND: Ultrasound is an established imaging modality in general surgery. With the increasing use of bedside point-of-care ultrasounds, general surgeons have been incorporating this skill into their clinical practice. This systematic review provides an up-to-date summary of the evidence for abdominal ultrasound scans performed by general surgeons to diagnose intra-abdominal pathology. METHODS: Two independent reviewers searched the PubMed database between 1 January 1980 and 1 June 2020. Articles about surgeon-performed abdominal ultrasound in adult patients were included. Studies on trauma and vascular surgery were excluded. RESULTS: 26 articles met the inclusion criteria, presented as a narrative analysis. There was good evidence for the use of surgeon-performed ultrasound, particularly in gallstone-related diseases and moderate evidence for the use of ultrasound in appendicitis. Further evidence is required for point-of-care ultrasounds for other pathologies such as diverticulitis and groin hernias. Ultrasound training for general surgeons is variable with notable heterogeneity across studies. CONCLUSION: A standardised training programme for general surgeons will greatly improve confidence and skill. There is good evidence for the use of bedside ultrasound by general surgeons in the acute and elective setting with reduced time to definitive treatment and fewer unnecessary hospital admissions.

Peritonsillar abscess drainage: using oropharyngeal endoscopy as a therapeutic adjunct and training tool.

BACKGROUND: Peritonsillar abscess, or quinsy, is one of the most common emergency presentations to ENT departments, and is the most common deep tissue infection of the head and neck. In the UK, junior members of the ENT team are regularly required to independently assess, diagnose and treat patients with peritonsillar aspiration or incision and drainage. ISSUE: Inexperienced practitioners can stumble at several obstacles: poor access due to trismus; poor lighting; difficulty in learning the therapeutic procedure; and difficulty in accurately documenting findings and treatment. SOLUTION: To counter these and other difficulties, the authors describe the routine use of video endoscopy as a training tool and therapeutic adjunct in the management of quinsy.

Major colorectal resection is feasible using a new robotic surgical platform: the first report of a case series.

BACKGROUND: The number of abdominal procedures performed via a robotic-assisted approach is increasing as potential advantages of the modality are recognised. We report the first in human case series of major colorectal resection performed using a new system, Versius®, and assess the feasibility of its use. METHODS: The initial cases performed using Versius® at a single centre in the UK were included in the study. Anonymised data were prospectively collected including patient demographics, operative details and postoperative outcomes. RESULTS: Twenty-three operations were performed, including left (n = 14) and right (n = 9)-sided colonic resections. Rectal mobilisation was performed in 13. Fifty-seven percent of the patients were male, with a malignant indication for surgery in 70% of cases. Overall mean age was 59.1 ± 15.3 (range 23-89) years. Overall mean body mass index was 28.9 ± 5.2 with a mean of 31.3 ± 4.5 for left-sided resections. The median console operating time was 166 min (range 75-320 min). All malignant cases had negative resection margins and the mean lymph node yield was 18 (SD 9.4). Only one operation (4%) was converted from robotic to open approach. Postoperative length of stay was a median of 5 days (range 3-34 days) and there were no readmissions within 30 days. CONCLUSIONS: These results compare favourably with the literature on existing robotic systems and also conventional laparoscopic surgery; hence, we believe that this series indicates the Versius® system is feasible for use in major colorectal resection. These early results from a robot-naïve centre show exciting promise for an expanding robotic market and highlight the need for further evaluation.

Strengthened capacity of India´s bedaquiline Conditional Access Programme for introducing new drugs and regimens.

BACKGROUND: Addressing TB in India is critical to meeting global targets. With the scale-up of diagnostic networks and the availability of new TB drugs, India had the opportunity to improve the detection and treatment outcomes in drug-resistant TB (DR-TB).OBJECTIVE: To document how the introduction of new drugs and regimens is helping India improve the care of DR-TB patients.DESIGN: In 2016, India´s National TB Programme (NTP) introduced bedaquiline (BDQ) under a Conditional Access Programme (BDQ-CAP) at six sites after providing extensive training and strengthening laboratory testing, pre-treatment evaluation, active drug safety monitoring and management (aDSM) and follow-up systems.RESULTS: An interim analysis reflected earlier and better culture conversion rates: 83% of the 620 patients converted within a median time of 60 days. However, 248 serious adverse events were reported, including 73 deaths (12%) and 100 cardiotoxicity events (16.3%). Encouraged by the evidence of safety and efficacy of BDQ, the NTP took steps to systematically expand its access to cover the entire population by 2018.CONCLUSION: The cautious yet focused approach used to introduce BDQ under BDQ-CAP paved the way for the rapid introduction of delamanid, as well as the shorter treatment regimen and the all-oral regimen for DR-TB.

ENT training amongst general practitioners: results from a questionnaire.

OBJECTIVES: To evaluate the level of undergraduate and post-graduate ENT exposure amongst general practitioners and their perceived quality of this training. A secondary aim was to examine whether general practitioners believe ENT department based rotations should remain in the undergraduate curriculum. METHOD: An online questionnaire-based survey was sent to general practices in England. RESULTS: A total of 417 general practitioners completed the questionnaire. Sixty-seven per cent had completed an ENT rotation at medical school whereas 27 per cent had undertaken a postgraduate placement in ENT. Fifty-one per cent had received post-graduate teaching in ENT, mainly in the form of lectures. The majority of general practitioners were not satisfied with their training in ENT at undergraduate and post-graduate levels. Eighty-five per cent of general practitioners believed formal hospital-based ENT training should remain in the undergraduate curriculum. CONCLUSION: General practitioners reported insufficient exposure to ENT during both post-graduate and undergraduate training. Proposals to outsource undergraduate ENT teaching to affiliated departments such as general practice are of concern.