Cholestasis after Kasai operation predicts portal hypertension in native liver survivors of biliary atresia: a multicenter study.

PURPOSE: This study evaluated portal hypertension (PHT) and its predictors among native liver survivors (NLS) of biliary atresia (BA) after Kasai portoenterostomy (KPE). METHODS: This was a multicenter study using prospectively collected data. The subjects were patients who remained transplant-free for 5 years after KPE. Their status of PHT was evaluated and variables that predicted PHT were determined by regression analysis and receiver operating characteristic (ROC) curve. RESULTS: Six centers from East Asia participated in this study and 320 subjects with KPE between 1980 to 2018 were analyzed. The mean follow-up period was 10.6 ± 6.2 years. At the 5th year after KPE, PHT was found in 37.8% of the subjects (n = 121). Patients with KPE done before day 41 of life had the lowest percentage of PHT compared to operation at older age. At 12 months after KPE, PHT + ve subjects had a higher bilirubin level (27.1 ± 11.7 vs 12.3 ± 7.9 µmol/L, p = 0.000) and persistent jaundice conferred a higher risk for PHT (OR = 12.9 [9.2-15.4], p = 0.000). ROC analysis demonstrated that a bilirubin level above 38 µmol/L at 12 months after KPE predicted PHT development (sensitivity: 78%, specificity: 60%, AUROC: 0.75). CONCLUSIONS: In BA, early KPE protects against the development of PHT among NLSs. Patients with persistent cholestasis at one year after KPE are at a higher risk of this complication. They should receive a more vigilant follow-up. LEVEL OF EVIDENCE: Level III.

Regenerative Peripheral Nerve Interface: Surgical Protocol for a Randomized Controlled Trial in Postamputation Pain.

Surgical procedures, including nerve reconstruction and end-organ muscle reinnervation, have become more prominent in the prosthetic field over the past decade. Primarily developed to increase the functionality of prosthetic limbs, these surgical procedures have also been found to reduce postamputation neuropathic pain. Today, some of these procedures are performed more frequently for the management and prevention of postamputation pain than for prosthetic fitting, indicating a significant need for effective solutions to postamputation pain. One notable emerging procedure in this context is the Regenerative Peripheral Nerve Interface (RPNI). RPNI surgery involves an operative approach that entails splitting the nerve end longitudinally into its main fascicles and implanting these fascicles within free denervated and devascularized muscle grafts. The RPNI procedure takes a proactive stance in addressing freshly cut nerve endings, facilitating painful neuroma prevention and treatment by enabling the nerve to regenerate and innervate an end organ, i.e., the free muscle graft. Retrospective studies have shown RPNI's effectiveness in alleviating postamputation pain and preventing the formation of painful neuromas. The increasing frequency of utilization of this approach has also given rise to variations in the technique. This article aims to provide a step-by-step description of the RPNI procedure, which will serve as the standardized procedure employed in an international, randomized controlled trial (ClinicalTrials.gov, NCT05009394). In this trial, RPNI is compared to two other surgical procedures for postamputation pain management, specifically, Targeted Muscle Reinnervation (TMR) and neuroma excision coupled with intra-muscular transposition and burying.

Targeted Muscle Reinnervation: Surgical Protocol for a Randomized Controlled Trial in Postamputation Pain.

Over the past decade, the field of prosthetics has witnessed significant progress, particularly in the development of surgical techniques to enhance the functionality of prosthetic limbs. Notably, novel surgical interventions have had an additional positive outcome, as individuals with amputations have reported neuropathic pain relief after undergoing such procedures. Subsequently, surgical techniques have gained increased prominence in the treatment of postamputation pain, including one such surgical advancement - targeted muscle reinnervation (TMR). TMR involves a surgical approach that reroutes severed nerves as a type of nerve transfer to "target" motor nerves and their accompanying motor end plates within nearby muscles. This technique originally aimed to create new myoelectric sites for amplified electromyography (EMG) signals to enhance prosthetic intuitive control. Subsequent work showed that TMR also could prevent the formation of painful neuromas as well as reduce postamputation neuropathic pain (e.g., Residual and Phantom Limb Pain). Indeed, multiple studies have demonstrated TMR's effectiveness in mitigating postamputation pain as well as improving prosthetic functional outcomes. However, technical variations in the procedure have been identified as it is adopted by clinics worldwide. The purpose of this article is to provide a detailed step-by-step description of the TMR procedure, serving as the foundation for an international, randomized controlled trial (ClinicalTrials.gov, NCT05009394), including nine clinics in seven countries. In this trial, TMR and two other surgical techniques for managing postamputation pain will be evaluated.

Direct Clinical Pharmacist-Patient Telephone Follow-Up: A Focus on GI Medical Oncology Symptom Management.

PURPOSE: GI medical oncology care presents unique medication challenges. Here, we captured our clinical pharmacy specialists' (CPSs) involvement in patients with GI cancers starting cycle 1 of a new treatment. METHODS: Our quality initiative was performed in three stages (preintervention, intervention, and postintervention). Preintervention: retrospective baseline data collection from May to December 2019. Intervention: one-time telephone encounters were conducted by a CPS between March 15 and June 11, 2021. The primary objective of the quality improvement initiative was to increase patient interaction with a CPS to 80%. Postintervention: data collection to review the impact of CPS telephone encounters. RESULTS: Preintervention: we reviewed the electronic health records of 262 patients. Sixty nine percent of patients reported at least one adverse event (AE; range 1-6 AEs) at the first physician follow-up after treatment start. Most reported AEs (78%) were considered modifiable within the scope of CPS practice. Postintervention: during the intervention, 92% of patients (n = 389) received a telehealth encounter with the CPS. At the encounter, 315 patients (81%) reported at least one AE. CPS provided recommendations and/or additional education for 88% of reported AEs. Medication lists required correction 75% of the time. The median time for CPS encounters (including documentation) was 40 minutes. CONCLUSION: During a 3-month period, this quality improvement initiative successfully provided an early CPS-based telehealth intervention to identify and make initial recommendations for management of AEs for patients on cycle 1 of systemic therapy for GI cancer.

Hepatic Metastasectomy in Squamous Cell Carcinoma of the Anal Canal: A Case Series of a Curative Approach.

BACKGROUND: Squamous cell carcinoma of the anal canal (SCCA) is rare. Most cases are diagnosed in a localized setting. Metastatic SCCA is rare, and investigation has been limited in the past for these patients. We believe that hepatic-only metastatic disease could have a unique treatment landscape compared to diseases with diffuse metastatic involvement. Here, we describe cases at our institution. METHODS: We reviewed eight SCCA cases with hepatic-only metastatic disease (diagnosed February 2018-January 2022). The objectives were to determine the overall survival and disease-free survival with this approach. RESULTS: The median age was 62 years old (yo). Patients had an ECOG of 0-1. All patients received definitive chemoradiation to their primary anal tumor. A median of three months of neoadjuvant systemic therapy was provided. All patients had a response on their first scan after systemic therapy. Sixty-two percent received carboplatin + paclitaxel. A complete pathologic response was seen in 62% of patients. At their last follow-up, all patients were alive. Three patients had recurrent disease. The estimated 1-year disease-free survival probability was 56.2%. CONCLUSION: Our report shows the feasibility of a curative-intent approach for patients with hepatic-only metastatic SCCA following the neoadjuvant application of carboplatin + paclitaxel. This approach appears promising in these select patients and warrants further investigation.

Multi-Parametric Radiomic Model to Predict 1p/19q Co-Deletion in Patients with IDH-1 Mutant Glioma: Added Value to the T2-FLAIR Mismatch Sign.

PURPOSE: The T2-FLAIR mismatch sign has shown promise in determining IDH mutant 1p/19q non-co-deleted gliomas with a high specificity and modest sensitivity. To develop a multi-parametric radiomic model using MRI to predict 1p/19q co-deletion status in patients with newly diagnosed IDH1 mutant glioma and to perform a comparative analysis to T2-FLAIR mismatch sign+. METHODS: In this retrospective study, patients with diagnosis of IDH1 mutant gliomas with known 1p/19q status who had preoperative MRI were included. T2-FLAIR mismatch was evaluated independently by two board-certified neuroradiologists. Texture features were extracted from glioma segmentation of FLAIR images. eXtremeGradient Boosting (XGboost) classifiers were used for model development. Leave-one-out-cross-validation (LOOCV) and external validation performances were reported for both the training and external validation sets. RESULTS: A total of 103 patients were included for model development and 18 patients for external testing validation. The diagnostic performance (sensitivity/specificity/accuracy) in the determination of the 1p/19q co-deletion status was 59%/83%/67% (training) and 62.5%/70.0%/66.3% (testing) for the T2-FLAIR mismatch sign. This was significantly improved (p = 0.04) using the radiomics model to 77.9%/82.8%/80.3% (training) and 87.5%/89.9%/88.8% (testing), respectively. The addition of radiomics as a computer-assisted tool resulted in significant (p = 0.02) improvement in the performance of the neuroradiologist with 13 additional corrected cases in comparison to just using the T2-FLAIR mismatch sign. CONCLUSION: The proposed radiomic model provides much needed sensitivity to the highly specific T2-FLAIR mismatch sign in the determination of the 1p/19q non-co-deletion status and improves the overall diagnostic performance of neuroradiologists when used as an assistive tool.

Prospective Randomized Controlled Trial Comparing Laparoscopic Palomo Surgery vs Scrotal Antegrade Sclerotherapy in Adolescent Varicocele.

PURPOSE: Varicocele is a common condition in adolescence and the most common correctable cause of infertility. This study aimed to analyze and compare the outcomes of scrotal antegrade sclerotherapy and laparoscopic Palomo surgery in a tertiary referral center. MATERIALS AND METHODS: Patients with left grade 3 varicocele indicated for surgery were prospectively enrolled and randomly allocated to the scrotal antegrade sclerotherapy and laparoscopic Palomo surgery groups, with their respective contralateral normal testes taken as controls. The primary outcome measures were clinical varicocele recurrence, testicular catch-up growth, and postoperative hydrocele. All patients were evaluated clinically and using Doppler ultrasound by radiologists. RESULTS: From 2015 to 2020, 113 patients completed the study and were statistically analyzed (scrotal antegrade sclerotherapy, n = 57; laparoscopic Palomo surgery, n = 56). All patients had significantly smaller testes preoperatively; the testicular volume differences with control testes were -23% in scrotal antegrade sclerotherapy and -19% in laparoscopic Palomo surgery. At 12-month follow-up, there were no statistically significant differences in clinical recurrences between the 2 groups (scrotal antegrade sclerotherapy = 5.3% vs laparoscopic Palomo surgery = 5.4%, P > .05, noninferiority test). Testicular catch-up growths were observed in both groups; the mean testicular volume difference between the treatment and control testes decreased from -23% to -8.1% in scrotal antegrade sclerotherapy (P < .001) and from -19% to -9.3% in laparoscopic Palomo surgery (P < .001) at 12-month follow-up. There was no postoperative hydrocele in the scrotal antegrade sclerotherapy group compared to 7 cases in the laparoscopic Palomo surgery group (0% vs 13%, P = .006). CONCLUSIONS: Both scrotal antegrade sclerotherapy and laparoscopic Palomo surgery are safe and effective procedures for treatment of adolescent varicocele with significant positive effect on testicular catch-up growth. Scrotal antegrade sclerotherapy is not inferior to laparoscopic Palomo surgery in terms of clinical recurrence rate and has significantly less postoperative hydrocele.

Correlation of urodynamic studies and somatosensory evoked potential and their prognostic value in children with closed spinal dysraphism.

INTRODUCTION: Somatosensory evoked potential (SSEP) and urodynamic studies (UD) are valuable tools for assessing patients with closed spinal dysraphism (CSD) before neurosurgical intervention. No studies have correlated their findings in this cohort and our aim is to study their correlation and prognostic value in pediatric patients with closed spinal dysraphism. METHODS: Retrospective review of all patients referred to a multidisciplinary clinic in a tertiary pediatric surgical center over a 17 years period between April 2004 to September 2021 was performed. Inclusion criteria were <18 years old, diagnosed with CSD, with SSEP and UD done within 1 year of each other. Demographics data collected include age at presentation/at referral/at neurosurgical operation, gender, symptoms at presentation and intra-operative diagnoses. Pre-operative SSEP and UD findings were documented. Primary outcome was UD results in the group with normal and abnormal SSEP. Secondary outcome was urological and bowel function outcome in 4 groups of patients (Group A-both normal SSEP and UD, Group B- abnormal SSEP only, Group C - abnormal UD only and Group D-both abnormal SSEP and UD). RESULTS: A total of 45 patients were included for analysis. Mean follow up time was 118.9 months (24-216 months, SD 55.8 months). SSEP was normal in 20 patients and abnormal in 25 patients. Baseline demographics, preoperative symptoms and imaging were similar between 2 groups. Primary outcome Patients with abnormal SSEP were more likely to have abnormal UD results with a statistically significant difference (84% vs 40%, p < 0.05). They have a significantly higher end-fill detrusor pressure (12% vs 0%, p < 0.05), abnormal bladder compliance (20% vs 0%, p < 0.05), abnormal cystometric capacity (48% vs 10%, p < 0.05), poor emptying efficiency (24% vs 5%, p < 0.05) and sphincter incompetence (8% vs 0%, p < 0.05). Secondary outcome When compared to Groups A to C, patients in group D were more likely to be on anti-cholinergic (33.3% vs 4.3%, p < 0.05), required clean intermittent catheterization (42.9% vs 4.3%, p < 0.05) and had intravesical botulinum injection (19% vs 0%, p < 0.05). All the patients who had augmentation cystoplasty were in this group as well. Bowel function in terms of regular enema use was also statistically significantly higher in this group (33.4% p < 0.05). CONCLUSION: Pre-operative SSEP and UD results correlate well in patients with closed spinal dysraphism. Patients with abnormal SSEP and UD preoperatively have higher risk of urological deterioration over time. Close monitoring in this group is warranted.

Long lasting effect on testes following methylene blue injection in laparoscopic lymphatic sparing varicocelectomy.

OBJECTIVE: Injection of methylene blue to testis has been shown to have adverse effect in animal studies but it is still being used frequently as lymphatic mapping agent during lymphatic sparing varicocelectomy in adolescent varicoceles. We aim to report postoperative ultrasound changes after subaortic injection of methylene blue in human testes. STUDY DESIGN: A retrospective observational study of consecutive patients under 18 years old undergoing laparoscopic varicocelectomy from August 2017 to August 2021 was performed. Demographics such as age, symptoms, pre-operative testicular volume was collected. Primary outcome was change on testicular ultrasound at 3, 6, 12 months after the operation. Secondary outcome was testicular volume difference between affected and unaffected testes, and growth rate of affected testis at 1 year after the operation. RESULTS: Fifty-eight patients were included, with median age of 15 years old (IQR 11-18 years). Thirty-one patients had non-lymphatic sparing varicocelectomy (Group A) and 27 patients had lymphatic sparing varicocelectomy (Group B). There was no statistical difference between the mean testicular volume difference between the two groups, but hydrocele rate was significantly higher in Group A (16% vs 0%, p = 0.03). In group B, 6 patients (22.2%, p = 0.005) developed testicular change detectable by ultrasound. No statistical difference could be demonstrated for median testicular size difference (between affected and unaffected testes) at 1 year between group with and without ultrasound change (-23% vs 0%, p = 0.36). Median follow up time was 20.4 months (IQR 5-32 months). DISCUSSION: Varicocele treatments improve testicular volume and increase total sperm concentration and lymphatic sparing surgery significantly decreased post-operative hydrocele rates [2]. Different agents have been used to delineate lymphatic vessels and one commonly used agent is methylene blue [10,15-16]. However it has been shown in other animal studies that intraparenchymal injection of methylene blue to rat testis result in degenerative changes [18]. Our study is the first to describe post-operative changes of human testes on imaging after lymphatic sparing varicocelectomy with subdartoic injection of methylene blue. Six patients (22.2%) demonstrated new onset testicular changes on post-operative ultrasound. Although no statistically significant testicular volume reduction was seen in the group with change on imaging, these observations may serve as a surrogate marker for testicular injury or reduced testicular function. It will be desirable for future studies if we can investigate it further with hormonal markers or semen analysis after puberty has been reached. CONCLUSION: Lymphatic sparing procedure reduced post-operative hydrocele in adolescent varicocele, however long-lasting effect on testis is evident with subdartoic injection of methylene blue. This agent must be used with caution and long term follow up of these patients are needed.

DICER1 -Altered Extraovarian Moderately Differentiated Sertoli-Leydig Cell Tumor: Report of a Rare Case.

We report an unusual case of a pelvic extraovarian moderately differentiated Sertoli-Leydig cell tumor arising in a 4-yr-old female. The tumor contained a DICER1 pathogenic variant which was absent in the germline ruling out DICER1 syndrome. In reporting this case, we discuss the differential diagnosis and possible histogenesis and review reported cases of extraovarian Sertoli-Leydig cell tumor.

Metastatic or Locally Recurrent Anal Squamous Cell Carcinoma (SCAC): Current Clinical Trial Landscape and Novel Approaches.

Anal squamous cell carcinoma (SCAC) is a human papillomavirus (HPV) driven malignancy. Given inadequate HPV-vaccination rates, SCAC will continue to be a public health concern. SCAC is commonly diagnosed in the local or locoregional setting in which definitive chemoradiation provides the opportunity for cure and has high control rates. A minority of patients will develop recurrence or present with metastatic SCAC. Given the rarity of this disease, research has lagged compared to many other solid tumors. Historically, treatment has been based on extrapolating management approaches from more common squamous cell carcinoma malignancies and/or small case series or case reports. Fortunately, dedicated prospective clinical trial investigation in the advanced setting has emerged in recent years. Here, we review the current strategies for treatment along with remaining challenges and viable next steps for the management of metastatic SCAC.

Investigating the relationship between melatonin patterns and methylation in circadian genes among day shift and night shift workers.

OBJECTIVES: Mechanisms underlying the carcinogenicity of night shift work remain uncertain. One compelling yet understudied cancer mechanism may involve altered DNA methylation in circadian genes due to melatonin secretion patterns. The objective of this study was to explore the relationship between melatonin secretion patterns and circadian gene methylation among day and night shift workers. METHODS: Female healthcare employees (n=38 day workers, n=36 night shift workers) for whom we had urinary 6-sulfatoxymelatonin secretion data from a previous study were recontacted. New blood samples were collected and used to measure methylation levels at 1150 CpG loci across 22 circadian genes using the Illumina Infinium MethylationEPIC beadchip. Linear regression was used to examine the association between melatonin (acrophase and mesor) and M values for each CpG site (false discovery rate, q=0.2), while testing for effect modification by shift work status. RESULTS: Among night shift workers, a higher mesor (24 hours of mean production of melatonin) was associated with increased methylation in the body of RORA (q=0.02) and decreased methylation in the putative promoter region of MTNR1A (q=0.03). Later acrophase (ie, time of peak concentration) was associated with increased methylation in the putative promoter region of MTNR1A (q=0.20) and decreased methylation in the body of PER3 (q=0.20). No associations were identified among day workers. CONCLUSIONS: In conclusion, patterns in melatonin secretion were associated with differential circadian gene methylation among night shift workers. Melatonin and alteration of DNA methylation in circadian genes may be one pathway towards increased cancer risk, although larger-scale studies examining multiple time points are needed.

Atomically Dispersed Iron Metal Site in a Porphyrin-Based Metal-Organic Framework for Photocatalytic Nitrogen Fixation.

The rational design of photocatalysts for efficient nitrogen (N2) fixation at ambient conditions is important for revolutionizing ammonia production and quite challenging because the great difficulty lies in the adsorption and activation of the inert N2. Inspired by a biological molecule, chlorophyll, featuring a porphyrin structure as the photosensitizer and enzyme nitrogenase featuring an iron (Fe) atom as a favorable binding site for N2via π-backbonding, here we developed a porphyrin-based metal-organic framework (PMOF) with Fe as the active center as an artificial photocatalyst for N2 reduction reaction (NRR) under ambient conditions. The PMOF features aluminum (Al) as metal node imparting high stability and Fe incorporated and atomically dispersed by residing at each porphyrin ring promoting the adsorption and the activation of N2, termed Al-PMOF(Fe). Compared with the pristine Al-PMOF, Al-PMOF(Fe) exhibits a substantial enhancement in NH3 yield (635 µg g-1cat.) and production rate (127 µg h-1 g-1cat.) of 82% and 50%, respectively, on par with the best-performing MOF-based NRR catalysts. Three cycles of photocatalytic NRR experimental results corroborate a stable photocatalytic activity of Al-PMOF(Fe). The combined experimental and theoretical results reveal that the Fe-N site in Al-PMOF(Fe) is the active photocatalytic center that can mitigate the difficulty of the rate-determining step in photocatalytic NRR. The possible reaction pathways of NRR on Al-PMOF(Fe) were established. Our study of porphyrin-based MOF for the photocatalytic NRR will provide insight into the rational design of catalysts for artificial photosynthesis.

Boosting Oxygen Reduction of Single Iron Active Sites via Geometric and Electronic Engineering: Nitrogen and Phosphorus Dual Coordination.

Atomically dispersed transition metal active sites have emerged as one of the most important fields of study because they display promising performance in catalysis and have the potential to serve as ideal models for fundamental understanding. However, both the preparation and determination of such active sites remain a challenge. The structural engineering of carbon- and nitrogen-coordinated metal sites (M-N-C, M = Fe, Co, Ni, Mn, Cu, etc.) via employing new heteroatoms, e.g., P and S, remains challenging. In this study, carbon nanosheets embedded with nitrogen and phosphorus dual-coordinated iron active sites (denoted as Fe-N/P-C) were developed and determined using cutting edge techniques. Both experimental and theoretical results suggested that the N and P dual-coordinated iron sites were favorable for oxygen intermediate adsorption/desorption, resulting in accelerated reaction kinetics and promising catalytic oxygen reduction activity. This work not only provides efficient way to prepare well-defined single-atom active sites to boost catalytic performance but also paves the way to identify the dual-coordinated single metal atom sites.

Developing Microsurgery through Experience in Yangon General Hospital, Myanmar.

Although many surgical centers perform microsurgery routinely in developed countries, performing microsurgery is challenging in resource-poor developing countries, such as Myanmar. With the establishment of educational training programs and the assistance of volunteer plastic surgical teams, local plastic surgeons can learn the techniques of microsurgery and apply them clinically. The purpose of this study was to establish baseline data and define the challenges of performing microsurgery in Yangon General Hospital, Myanmar. Sixty-four patients underwent reconstruction with free flaps from January 2015 to January 2018. All clinical records of these cases were assessed. The number of free flap reconstructions performed increased from 11 in the first year to 24 in the third year. The anterolateral thigh flap was the most commonly used (42%). The most common sites of reconstruction were mandible and intraoral defects. Total flap survival occurred in 58 of 64 patients (89%). The total salvageable flap rate for revision surgery was 66.6%; the successful revision rate was highest in 2017, with fewer complications. The flap salvage rates increased and the operative duration decreased as clinical experience improved. Establishing a microsurgical center requires a strong multidisciplinary team, clinical experience, continuous learning, sensible clinical application, and effective interdepartmental and intradepartmental cooperation.

Quantification of computational geometric congruence in surface-based registration for spinal intra-operative three-dimensional navigation.

BACKGROUND CONTEXT: Computer-assisted navigation (CAN) may guide spinal instrumentation, and requires alignment of patient anatomy to imaging. Iterative closest-point (ICP) algorithms register anatomical and imaging surface datasets, which may fail in the presence of geometric symmetry (congruence), leading to failed registration or inaccurate navigation. Here we computationally quantify geometric congruence in posterior spinal exposures, and identify predictors of potential navigation inaccuracy. METHODS: Midline posterior exposures were performed from C1-S1 in four human cadavers. An optically-based CAN generated surface maps of the posterior elements at each level. Maps were reconstructed to include bilateral hemilamina, or unilateral hemilamina with/without the base of the spinous process. Maps were fitted to symmetrical geometries (cylindrical/spherical/planar) using computational modelling, and the degree of model fit quantified based on the ratio of model inliers to total points. Geometric congruence was subsequently assessed clinically in 11 patients undergoing midline exposures in the cervical/thoracic/lumbar spine for posterior instrumented fusion. RESULTS: In cadaveric testing, increased cylindrical/spherical/planar symmetry was seen in the high-cervical and subaxial cervical spine relative to the thoracolumbar spine (p<0.001). Extension of unilateral exposures to include the ipsilateral base of the spinous process decreased symmetry independent of spinal level (p<0.001). In clinical testing, increased cylindrical/spherical/planar symmetry was seen in the subaxial cervical relative to the thoracolumbar spine (p<0.001), and in the thoracic relative to the lumbar spine (p<0.001). Symmetry in unilateral exposures was decreased by 20% with inclusion of the ipsilateral base of the spinous process. CONCLUSIONS: Geometric congruence is most evident at C1 and the subaxial cervical spine, warranting greater vigilance in navigation accuracy verification. At all levels, inclusion of the base of the spinous process in unilateral registration decreases the likelihood of geometric symmetry and navigation error. This work is important to allow the extension of line-of-sight based registration techniques to minimally-invasive unilateral approaches.

Collagenase Management of Multicord Dupuytren's Disease under Intravenous Sedation: A Prospective Cohort Study.

BACKGROUND: Surgery has been the standard of care in managing Dupuytren's disease (DD). Recently collagenase of Clostridium histolyticum (CCH) has provided a less invasive alternative. The purpose of the current study is to present the early outcomes of a protocol for CCH involving treatment of multi-cord disease, and large patient cohorts. METHODS: A cohort of 137 consecutive patients (Mean age 66 years, SD 9.85) with 225 joint contractures was treated with CCH at our institution between December of 2014 and January of 2017. A single standardized concentration of collagenase 2.31 mg/ml or 0.58 mg/dose was used for the treatment of up to 5 cords at a single session, and manipulation was 48 hours post-injection under intravenous sedation (IV). Patient complications, reduction in joint contracture, patient satisfaction and patient reported functional outcomes were assessed after one month. RESULTS: 137 patients received a total of 214 doses 0.58mg of CCH to treat 225 PIP and MCP joint contractures. The mean correction of joint contractures was 39.8 ± 2.2 and 27.9 ± 3.9 degrees for MCP and PIP joints respectively. 80% of patients, reported improved function and 89% of patients who were satisfied with the treatment. CONCLUSIONS: This study demonstrates a protocol for high throughput management of DD using collagenase and IV sedation for manipulation, logistically suited to the hospital setting. Efficacy was demonstrated treating patients with up to 5 cords, including those with bilateral disease. Future studies are needed to evaluate the durability of response in the medium and long term, and to evaluate cost benefits.

High Speed, High Density Intraoperative 3D Optical Topographical Imaging with Efficient Registration to MRI and CT for Craniospinal Surgical Navigation.

Intraoperative image-guided surgical navigation for craniospinal procedures has significantly improved accuracy by providing an avenue for the surgeon to visualize underlying internal structures corresponding to the exposed surface anatomy. Despite the obvious benefits of surgical navigation, surgeon adoption remains relatively low due to long setup and registration times, steep learning curves, and workflow disruptions. We introduce an experimental navigation system utilizing optical topographical imaging (OTI) to acquire the 3D surface anatomy of the surgical cavity, enabling visualization of internal structures relative to exposed surface anatomy from registered preoperative images. Our OTI approach includes near instantaneous and accurate optical measurement of >250,000 surface points, computed at >52,000 points-per-second for considerably faster patient registration than commercially available benchmark systems without compromising spatial accuracy. Our experience of 171 human craniospinal surgical procedures, demonstrated significant workflow improvement (41 s vs. 258 s and 794 s, p < 0.05) relative to benchmark navigation systems without compromising surgical accuracy. Our advancements provide the cornerstone for widespread adoption of image guidance technologies for faster and safer surgeries without intraoperative CT or MRI scans. This work represents a major workflow improvement for navigated craniospinal procedures with possible extension to other image-guided applications.