Review of mechanisms of expandable spine surgery devices

INTRODUCTION

Expandable devices such as interbody cages, vertebral body reconstruction cages, and intravertebral body expansion devices are frequently utilized in spine surgery. Since the introduction of expandable implants in the early 2000s, the variety of mechanisms that drive expansion and implant materials have steadily increased. By examining expandable devices that have achieved commercial success and exploring emerging innovations, we aim to offer an in-depth evaluation of the different types of expandable cages used in spine surgery and the underlying mechanisms that drive their functionality.

AREAS COVERED

We performed a review of expandable spinal implants and devices by querying the National Library of Medicine MEDLINE database and Google Patents database from 1933 to 2024. Five major types of mechanical jacks that drive expansion were identified: scissor, pneumatic, screw, ratchet, and insertion-expansion.

EXPERT OPINION

We identified a trend of screw jack mechanism being the predominant machinery in vertebral body reconstruction cages and scissor jack mechanism predominating in interbody cages. Pneumatic jacks were most commonly found in kyphoplasty devices. Critically reviewing the mechanisms of expansion and identifying trends among effective and successful cages allows both surgeons and medical device companies to properly identify future areas of development.

T1 Pedicle Subtraction Osteotomy With Subaxial Cervical Pedicle Screw Fixation

Patients suffering from ankylosing spondylitis are not only predisposed to the development of rigid cervicothoracic deformities but are also at an increased risk of cervical fractures. Deformity correction and stabilization are particularly challenging in this patient population due to the brittle bone quality and low bone mineral density. Thoracic pedicle subtraction osteotomy is a workhorse approach for the correction of focal severe kyphotic deformity with lower complication rates than 3-column osteotomy. Successful execution of an upper thoracic PSO requires careful presurgical planning as well as anticipation of the patient's postoperative needs. Here, we describe the use of a T1 PSO in the correction of a rigid cervicothoracic chin-on-chest deformity in a patient with AS. The risk of implant failure was reduced by the use of a multi-rod construct, navigated cervical pedicle screws, and dual-pitched thoracic pedicle screws.

Clinical presentation and extent of resection impacts progression-free survival in spinal ependymomas

PURPOSE

Primary treatment of spinal ependymomas involves surgical resection, however recurrence ranges between 50 and 70%. While the association of survival outcomes with lesion extent of resection (EOR) has been studied, existing analyses are limited by small samples and archaic data resulting in an inhomogeneous population. We investigated the relationship between EOR and survival outcomes, chiefly overall survival (OS) and progression-free survival (PFS), in a large contemporary cohort of spinal ependymoma patients.

METHODS

Adult patients diagnosed with a spinal ependymoma from 2006 to 2021 were identified from an institutional registry. Patients undergoing primary surgical resection at our institution, ≥ 1 routine follow-up MRI, and pathologic diagnosis of ependymoma were included. Records were reviewed for demographic information, EOR, lesion characteristics, and pre-/post-operative neurologic symptoms. EOR was divided into 2 classifications: gross total resection (GTR) and subtotal resection (STR). Log-rank test was used to compare OS and PFS between patient groups.

RESULTS

Sixty-nine patients satisfied inclusion criteria, with 79.7% benefitting from GTR. The population was 56.2% male with average age of 45.7 years, and median follow-up duration of 58 months. Cox multivariate model demonstrated significant improvement in PFS when a GTR was attained (p <.001). Independently ambulatory patients prior to surgery had superior PFS (p <.001) and OS (p =.05). In univariate analyses, patients with a syrinx had improved PFS (p =.03) and were more likely to benefit from GTR (p =.01). Alternatively, OS was not affected by EOR (p =.78).

CONCLUSIONS

In this large, contemporary series of adult spinal ependymoma patients, we demonstrated improvements in PFS when GTR was achieved.

Dialysis initiation for patients with decompensated cirrhosis when liver transplant is unlikely

PURPOSE OF REVIEW

The purpose of this review is to describe an approach that emphasizes shared decision-making for patients with decompensated cirrhosis and acute kidney injury when liver transplantation is either not an option, or unlikely to be an option.

RECENT FINDINGS

When acute kidney injury occurs on a background of decompensated cirrhosis, outcomes are generally poor. Providers can also be faced with prognostic uncertainty. A lack of guidance from nephrology and hepatology professional societies means that providers rely on expert opinion or institutional practice patterns.

SUMMARY

For patients who are unlikely to receive liver transplantation, the occurrence of acute kidney injury represents an opportunity for a goals of care conversation. In this article, we share strategies through which providers can incorporate more shared decision-making when caring for these patients. The approach involves creating prognostic consensus amongst multidisciplinary teams and then relying on skilled communicators to share the prognosis. Palliative care consultation can be useful when teams need assistance in the conversations.

Exoscopic supraorbital approach for a suprasellar craniopharyngioma

The authors present an operative video of a supraorbital craniotomy for resection of a suprasellar, supradiaphragmatic craniopharyngioma. The patient is a 62-year-old female who presented with 3 months of blurry vision secondary to a 2.5-cm suprasellar mass causing compression on the optic nerve. Supraorbital craniotomy was selected due to the supradiaphragmatic location of the tumor and the subsequent disadvantages, including CSF leakage, of other approaches such as the endoscopic endonasal approach. The operative video emphasizes optimizing operating room (OR) setup to improve surgeon ergonomics and comfort. The patient underwent an uncomplicated gross-total resection with subsequent discharge home the day after surgery. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23140.

Exposure to Agent Orange and Hepatocellular Carcinoma Among US Military Personnel

Importance

Hepatocellular carcinoma (HCC) and its mortality are on the rise. Viral hepatitis and alcohol are leading risk factors; however, other risk factors among veterans are less defined, including Agent Orange (AO), an herbicide linked to several cancers.

Objective

To assess the association of AO exposure and HCC in a national cohort of Vietnam veterans.

Design, Setting, and Participants

This retrospective cohort study included Vietnam veterans who served between 1966 and 1975, were male, were older than 18 years at the time of deployment, and had established follow-up in the Veterans Affairs (VA) between 2000 and 2019. Veterans with AO exposure were identified in the disability data via validated clinical surveys. Relevant clinical risk factors for cirrhosis and HCC were collected. Patients were stratified based on cirrhosis status, as defined by consecutive diagnosis found by documented International Classification of Diseases, Ninth Revision and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision scores or calculated Fibrosis-4 scores. Data were collected from January 1, 2019, to December 31, 2020, and analyzed from December 2020 to October 2023.

Main Outcome and Measures

Incident HCC was the primary outcome. AO and HCC association was estimated using a multivariable Cox regression analysis, with death and liver transplant as competing events.

Results

Of the 296 505 eligible veterans (222 545 [75.1%] White individuals and 44 342 [15.0%] Black individuals), 170 090 (57%) had AO exposure (mean [SD] age, 21.62 [3.49] years; 131 552 White individuals [83.2%] and 22 767 Black individuals [14.4%]) and 35 877 (12.1%) had cirrhosis. Veterans who were not exposed to AO were more likely to smoke (109 689 of 126 413 [86.8%] vs 146 061 of 170 090 [85.9%]); use alcohol (54 147 of 126 413 [42.8%] vs 71 951 of 170 090 [42.3%]) and have viral hepatitis (47 722 of 126 413 [37.8%] vs 58 942 of 170 090 [34.7%]). In a multivariable competing risk model, AO exposure was not associated with HCC. Among veterans with cirrhosis, self-identification as Hispanic individuals (aHR, 1.51; 95% CI, 1.30-1.75; P <.001) or Black individuals (aHR, 1.18; 95% CI, 1.05-1.32; P = .004), and having a diagnosis of viral hepatitis (aHR, 3.71; 95% CI, 3.26-4.24; P <.001), alcohol-associated liver disease (aHR, 1.32; 95% CI, 1.19-1.46; P <.001), and nonalcoholic fatty liver disease (NAFLD) (aHR, 1.92; 95% CI, 1.72-2.15; P <.001) were associated with HCC. Among veterans without cirrhosis, hypertension (aHR, 1.63; 95% CI, 1.23-2.15; P <.001) and diabetes (aHR, 1.52; 95% CI, 1.13-2.05; P = .005) were also associated with HCC. Early smoking and alcohol use were significant risk factors for HCC.

Conclusions and Relevance

In this large nationwide cohort study of Vietnam veterans, AO exposure was not associated with HCC. Smoking, alcohol, viral hepatitis, and NAFLD were the most important clinical risk factors for HCC.

Predictive Algorithm for Hepatic Steatosis Detection Using Elastography Data in the Veterans Affairs Electronic Health Records

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) has reached pandemic proportions. Early detection can identify at-risk patients who can be linked to hepatology care. The vibration-controlled transient elastography (VCTE) controlled attenuation parameter (CAP) is biopsy validated to diagnose hepatic steatosis (HS). We aimed to develop a novel clinical predictive algorithm for HS using the CAP score at a Veterans' Affairs hospital.

METHODS

We identified 403 patients in the Greater Los Angeles VA Healthcare System with valid VCTEs during 1/2018-6/2020. Patients with alcohol-associated liver disease, genotype 3 hepatitis C, any malignancies, or liver transplantation were excluded. Linear regression was used to identify predictors of NAFLD. To identify a CAP threshold for HS detection, receiver operating characteristic analysis was applied using liver biopsy, MRI, and ultrasound as the gold standards.

RESULTS

The cohort was racially/ethnically diverse (26% Black/African American; 20% Hispanic). Significant positive predictors of elevated CAP score included diabetes, cholesterol, triglycerides, BMI, and self-identifying as Hispanic. Our predictions of CAP scores using this model strongly correlated (r = 0.61, p < 0.001) with actual CAP scores. The NAFLD model was validated in an independent Veteran cohort and yielded a sensitivity of 82% and specificity 83% (p < 0.001, 95% CI 0.46-0.81%). The estimated optimal CAP for our population cut-off was 273.5 dB/m, resulting in AUC = 75.5% (95% CI 70.7-80.3%).

CONCLUSION

Our HS predictive algorithm can identify at-risk Veterans for NAFLD to further risk stratify them by non-invasive tests and link them to sub-specialty care. Given the biased referral pattern for VCTEs, future work will need to address its applicability in non-specialty clinics. Proposed clinical algorithm to identify patients at-risk for NAFLD prior to fibrosis staging in Veteran.

Palliative clinical trials in advanced chronic liver disease: Challenges and opportunities

Patients with advanced chronic liver disease have a complex symptom burden and many are not candidates for curative therapy. Despite this, provision of palliative interventions remains woefully inadequate, with an insufficient evidence base being a contributory factor. Designing and conducting palliative interventional trials in advanced chronic liver disease remains challenging for a multitude of reasons. In this manuscript we review past and ongoing palliative interventional trials. We identify barriers and facilitators and offer guidance on addressing these challenges. We hope that this will reduce the inequity in palliative care provision in advanced chronic liver disease.

Targets and study design for symptom-focused trials aimed at patients with cirrhosis: An expert consensus

BACKGROUND

Symptom-focused trials are critically needed for patients with cirrhosis. However, this work would benefit from standard processes and validated measures.

METHODS

A writing group was formed among hepatologists, nurses, palliative care providers, pharmacists, and clinical trial experts focused on symptom management in patients with cirrhosis to define the key (1) components of trial design, (2) symptom targets, (3) measurement, and (4) outcomes for each target. From July 2022 to January 2023, panelists participated in an iterative process of developing and arriving at a consensus for each component. The goal was to provide consensus definitions that can be operationalized in future clinical trials, including for patients with cirrhosis.

RESULTS

The panel reached a consensus on key reporting features for clinical trials, along with considerations for study design. Nine key symptom targets (muscle cramps, pruritus, pain, fatigue, sexual dysfunction, sleep disorders, depression and anxiety, nausea/vomiting, and dyspnea/breathlessness) were identified. The panel selected instruments that can be considered for clinical trials based on psychometric validation and previous experience. The panel identified ongoing needs, including instrument validation, safety data, evidence about non-pharmacologic interventions, and comparative effectiveness studies.

CONCLUSION

This expert panel identified key design, reporting, and measurement elements to standardize processes and measures in future symptom-focused clinical trials in the context of cirrhosis.

Abstract 5618: Multi-institutional validation of a radiomics-based artificial intelligence method for predicting response to PD-1/PD-L1 immune checkpoint inhibitor (ICI) therapy in stage IV NSCLC

There is an urgent clinical need to identify patients likely to benefit from immune checkpoint inhibitor ICI treatment. Approaches available in the clinic today, such as PD-L1 immunohistochemistry (IHC) and tumor mutation burden (TMB), are insufficient for this task, in part as differences in microenvironments expressed by individual tumors may lead to heterogeneous response patterns. Recent efforts exploring the utility of quantitative imaging (radiomic) biomarkers to predict response to ICIs have shown promise to provide a more accurate and scalable method. In contrast to previously published models, our work focuses on generalizable models for predicting individual lesion-level as well as patient-level response at 3-month follow-up per RECIST criteria, using a large multi-institutional “real-world” dataset. The models combine radiomics features with demographic, molecular, and laboratory values routinely available in patients’ electronic medical records. We analyzed radiomic characteristics of 6,295 primary and metastatic lesions from 1,206 metastatic NSCLC patients treated with anti-PD-1/anti-PD-L1 ICIs from 8 institutions across the US and Europe. Patients with unavailable PD-L1 IHC, imaging follow-up, or with oncogenic driver mutations were excluded from analysis, resulting in a total dataset of 766 subjects randomly assigned to training (N=514) and validation sets (N=252). Using gradient-boosted decision tree algorithms, we developed a multi-modal predictive model to identify patients responding to ICI therapy at 3-months and evaluated its performance against an imaging-only CT radiomics model and the clinical standard of care, biopsy-based PD-L1 IHC. The multi-modal model contains CT radiomic features capturing lesion heterogeneity and spicularity, patient demographics, PD-L1 TPS, and tumor burden volume in the lung, lymph nodes, and the liver. Under the two-tailed DeLong test, the multi-modal model demonstrated statistically significant benefit over the current standard of care (PD-L1 IHC) in predicting multi-lesion 3-month response: 0.81 (P=.005) area under the receiver operating characteristic curve (ROC-AUC) in first-line ICI monotherapy patients, 0.72 (P=.044) in all-lines ICI monotherapy, and 0.71 (P=.025) in all-lines ICI-chemotherapy combination. The imaging-only model demonstrated predictive performance comparable to PD-L1 IHC: 0.71 (P=.226), 0.61 (P=.905), 0.62 (P=.674) on the same cohorts respectively. A multi-modal CT radiomics-based approach demonstrated predictive accuracy benefit over the current clinical standard and may provide an opportunity for more personalized patient management, such as risk-based escalation/de-escalation of concurrent chemotherapy in NSCLC patients. We will evaluate this methodology in prospective studies.

Citation Format: Ravi B. Parikh, Petr Jordan, Rita J. Ciaravino, Ryan A. Beasley, Arpan A. Patel, Dwight H. Owen, Arya Amini, Brendan D. Curti, Ray Page, Aurelie Swalduz, Jean-Paul Beregi, Jan Chrusciel, Eric Snyder, Pritam Mukherjee, Heather M. Selby, Soohee Lee, Roshanthi Weerasinghe, Shwetha Pindikuri, Jakob B. Weiss, Andrew L. Wentland, Anish Kirpalani, An Liu, Olivier Gevaert, George Simon, Hugo JWL Aerts. Multi-institutional validation of a radiomics-based artificial intelligence method for predicting response to PD-1/PD-L1 immune checkpoint inhibitor (ICI) therapy in stage IV NSCLC. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5618.

Cultural humility and end-of-life communication with people with advanced liver disease

Content available: Audio Recording.

Cell Cycle Analysis of ER Stress and Autophagy

Autophagy and ER stress are most often studied employing a Western blotting approach to the measurement of autophagy by LC3B upregulation and the ER stress sensor signaling proteins PERK (protein kinase R-like endoplasmic reticulum kinase), IRE1, and ATF6 which initiate protein refolding and elongation of the ER until ER homeostasis is returned. If the misfolding of proteins is increased, then ER stress is maintained, and microautophagy of the ER or specifically reticulophagy occurs. However, LC3B, PERK, protein misfolding, and changes in ER mass (reticulophagy) can also be measured in a cell cycle-dependent manner by flow cytometry and the use of antibodies, protein misfolding, and ER tracking fluorescent probes.

Predictors of mortality and outcomes of liver transplant in spur cell hemolytic anemia

Spur cell hemolytic anemia (SCHA) is a rare, acquired, nonimmune hemolytic anemia of decompensated cirrhosis. Data describing prognostic impact, outcomes of liver transplant, and clinical hematologic characteristics of SCHA are absent or limited. We performed a multicenter, 24-year observational cohort study of patients with SCHA, retrospectively analyzing hepatic and hematologic parameters, independent predictors of mortality, and long-term outcomes of liver transplant. Sixty-nine patients with SCHA met eligibility for inclusion. The median (interquartile range) age was 53 (42-59) years; 46.4% were female, and 11 (15.9%) received liver transplant. Thirty-nine patients (56.5%) were red blood celltransfusion-dependent. All 11 patients undergoing transplant had rapid and complete resolution of SCHA, with improvement in median hematocrit from 22.1% to 34.6% post-transplant (p = .001) and excellent post-transplant outcomes. In multivariable logistic models adjusting for age, sex, etiology of cirrhosis, active/recent variceal bleeding, and Child-Turcotte-Pugh score, transfusion dependence had an odds ratio (OR) for 90-day mortality of 9.14 (95% CI, 2.46-34.00) and reduced pre-transfusion hematocrit had an OR of 4.73 (95% CI, 1.42-15.82) per 6% decrease; increased red cell transfusion requirement, reduced hemoglobin, increased lactate dehydrogenase, and increased indirect bilirubin were also independently predictive of higher 90-day mortality. Model for end-stage liver disease (MELD)-Na and Child-Turcotte-Pugh scores consistently significantly underestimated 90-day mortality, with standardized mortality ratios (SMRs) >1 across all scores/classes [MELD-Na 20-29, SMR 2.42 (1.18-4.44); Child-Turcotte-Pugh class B, SMR 4.46 (1.64-9.90)]. In conclusion, SCHA is associated with substantial excess mortality than predicted by MELD-Na or Child-Turcotte-Pugh scores and uniformly resolves with liver transplant, without recurrence. Multiple parameters of hemolytic anemia severity independently predict higher 90-day mortality.

Alcohol use disorder treatment and outcomes among hospitalized adults with alcoholic hepatitis

Purpose

: The burden of alcohol-associated liver disease (ALD) in the United States (US) has continued to worsen in the background of rising rates of alcohol use disorder. Patients with ALD present to care at a late stage, often with the sequela of liver decompensation, such as gastrointestinal bleeding and infection. ALD is now the leading indication for liver transplantation. We aimed to measure the quality of care delivered to hospitalized patients with alcoholic hepatitis (AH) across 3 domains: 1) alcohol-use disorder (AUD) care, 2) inpatient cirrhosis care, and 3) alcohol-associated liver disease (ALD) care-and observe associations between quality of care and outcomes.

Methods

: We included hospital encounters between January 1, 2016 and January 1, 2019 to a large, diverse integrated health system for AH with active alcohol use within the prior 60 days. The diagnosis of AH was determined based on previously published clinical and laboratory criteria. Quality indicator (QI) pass rates were calculated as the proportion of patients eligible for each indicator who received the QI within the timeframe specified. We then evaluated the association between the receipt of all QIs and 6-month mortality, as well as AUD-specific QIs and 30-day readmission.

Results

: Of the 179 patients, the median age was 47 years-old, 59.2% were male and 49.2% were non-Hispanic White. The median Model for End-Stage Liver Disease-Sodium score was 25, while the median discriminant function was 33. Patients were followed for an average of 21 months. Overall, 14% of patients died during the index hospitalization while 17.3% died following discharge and 24.8% were re-admitted within 30-days. QI pass-rates were variable across the different domains. Few patients received AUD care-pass rates for receipt of pharmacotherapy and behavioral therapy at 6 months were only 19.1% and 35.1%, respectively. There was a significant association between receiving behavioral therapy and 6-month mortality-3% vs 18%, p = 0.05.

Conclusion

: The quality of care received during hospital encounters for AH is variable, and AUD-specific therapy is low. Future quality of care initiatives are warranted to link patients to AUD treatment to ensure optimal care and maximize patients survival in this at-risk population.

Developing Priorities for Palliative Care Research in Advanced Liver Disease: A Multidisciplinary Approach

Individuals with advanced liver disease (AdvLD), such as decompensated cirrhosis (DC) and hepatocellular carcinoma (HCC), have significant palliative needs. However, little research is available to guide health care providers on how to improve key domains related to palliative care (PC). We sought to identify priority areas for future research in PC by performing a comprehensive literature review and conducting iterative expert panel discussions. We conducted a literature review using search terms related to AdvLD and key PC domains. Individual reviews of these domains were performed, followed by iterative discussions by a panel consisting of experts from multiple disciplines, including hepatology, specialty PC, and nursing. Based on these discussions, priority areas for research were identified. We identified critical gaps in the available research related to PC and AdvLD. We developed and shared five key priority questions incorporating domains related to PC. Conclusion: Future research endeavors focused on improving PC in AdvLD should consider addressing the five key priorities areas identified from literature reviews and expert panel discussions.

Acute on Chronic Liver Failure From Nonalcoholic Fatty Liver Disease: A Growing and Aging Cohort With Rising Mortality

BACKGROUND AND AIMS

We assessed the burden of nonalcoholic fatty liver disease (NAFLD)-related acute on chronic liver failure (ACLF) among transplant candidates in the United States, along with waitlist outcomes for this population.

APPROACH AND RESULTS

We analyzed the United Network for Organ Sharing registry from 2005 to 2017. Patients with ACLF were identified using the European Association for the Study of the Liver/Chronic Liver Failure criteria and categorized into NAFLD, alcohol-associated liver disease (ALD), and hepatitis C virus (HCV) infection. We used linear regression and Chow's test to determine significance in trends and evaluated waitlist outcomes using Fine and Gray's competing risks regression and Cox proportional hazards regression. Between 2005 and 2017, waitlist registrants for NAFLD-ACLF rose by 331.6% from 134 to 574 candidates (P < 0.001), representing the largest percentage increase in the study population. ALD-ACLF also increased by 206.3% (348-1,066 registrants; P < 0.001), whereas HCV-ACLF declined by 45.2% (P < 0.001). As of 2017, the NAFLD-ACLF population consisted primarily of persons aged ≥60 years (54.1%), and linear regression demonstrated a significant rise in the proportion of patients aged ≥65 in this group (β = 0.90; P = 0.011). Since 2014, NAFLD-ACLF grade 1 was associated with a greater risk of waitlist mortality relative to ALD-ACLF (subhazard ratio [SHR] = 1.24; 95% confidence interval [CI], 1.05-1.44) and HCV-ACLF (SHR = 1.35; 95% CI, 1.08-1.71), among patients aged ≥60 years. Mortality was similar among the three groups for patients with ACLF grade 2 or 3.

CONCLUSIONS

NAFLD is the fastest rising etiology of cirrhosis associated with ACLF among patients listed in the United States. As the NAFLD population continues to grow and age, patients with NAFLD-ACLF will likely have the highest risk of waitlist mortality.

Top Ten Tips Palliative Care Clinicians Should Know About End-Stage Liver Disease

End-stage liver disease (ESLD) is an increasingly prevalent condition with high morbidity and mortality, especially for those ineligible for liver transplantation. Patients with ESLD, along with their family caregivers, have significant needs related to their quality of life, and there is increasing attention being paid to integration of palliative care (PC) principles into routine care throughout the disease spectrum. To provide upstream care for these patients and their family caregivers, it is essential for PC providers to understand their complex psychosocial and physical needs and to be aware of the unique challenges around medical decision making and end-of-life care for this patient population. This article, written by a team of liver and PC experts, shares 10 high-yield tips to help PC clinicians provide better care for patients with advanced liver disease.

Innovations in Hepatitis C Screening and Treatment

New therapies offer hope for a cure to millions of persons living with hepatitis C virus (HCV) infection. HCV elimination is a global goal that will be difficult to achieve using the traditional paradigms of diagnosis and care. The current standard has evolved toward universal HCV screening and treatment, to achieve elimination goals. There are several steps between HCV diagnosis and cure with major barriers along the way. Innovative models of care can address barriers to better serve hardly reached populations and scale national efforts in the United States and abroad. Herein, we highlight innovative models of HCV care that aid in our progress toward HCV elimination.

Patient-Controlled Analgesia Following Lumbar Spinal Fusion Surgery Is Associated With Increased Opioid Consumption and Opioid-Related Adverse Events

BACKGROUND

Optimal postoperative pain control is critical after spinal fusion surgery. There remains significant variability in the use of postoperative intravenous opioid patient-controlled analgesia (PCA) and few data evaluating its utility compared with nurse-controlled analgesia (NCA) among patients with lumbar fusion.

OBJECTIVE

To investigate the efficacy of postoperative PCA compared with NCA to improve opiate prescription practices.

METHODS

A retrospective review from a single institution was conducted in consecutive patients treated with posterior lumbar spinal fusion for degenerative pathology. Patients were divided into cohorts on the basis of postoperative treatment with PCA or NCA. Postoperative pain scores, length of stay, and total opioid consumption data were collected. Patients were stratified according to preoperative opioid consumption as opioid naive (0 morphine milligram equivalents [MME] daily), low consumption (1-60 MME), high consumption (61-90 MME), or very high consumption (>90 MME).

RESULTS

A total of 240 patients were identified, including 62 in the PCA group and 178 in the NCA group. PCA patients had higher mean preoperative opioid consumption than NCA patients (49.2 vs 24.3 MME, P = .009). PCA patients had higher mean opioid consumption in the first 72 h in all 4 of the preoperative opioid consumption subcategories. Pain control and adverse event rates were similar between PCA and NCA in the low to high preoperative opioid consumption groups.

CONCLUSION

Postoperative PCA is associated with significantly more opioid consumption in the first 72 h after surgery and equal or worse postoperative pain scores compared with NCA after lumbar spinal fusion surgery.

Identifying Quality Gaps in Preventive Care for Outpatients With Cirrhosis Within a Large, Academic Health Care System

We sought to identify specific gaps in preventive care provided to outpatients with cirrhosis and to determine factors associated with high quality of care (QOC), to guide quality improvement efforts. Outpatients with cirrhosis who received care at a large, academic tertiary health care system in the United States were included. Twelve quality indicators (QIs), including preventive care processes for ascites, esophageal varices, hepatic encephalopathy, hepatocellular carcinoma (HCC), and general cirrhosis care, were measured. QI pass rates were calculated as the proportion of patients eligible for a QI who received that QI during the study period. We performed logistic regression to determine predictors of high QOC (≥ 75% of eligible QIs) and receipt of HCC surveillance. Of the 439 patients, the median age was 63 years, 59% were male, and 19% were Hispanic. The median Model for End-Stage Liver Disease-Sodium score was 11, 64% were compensated, and 32% had hepatitis C virus. QI pass rates varied by individual QIs, but were overall low. For example, 24% received appropriate HCC surveillance, 32% received an index endoscopy for varices screening, and 21% received secondary prophylaxis for spontaneous bacterial peritonitis. In multivariable analyses, Asian race (odds ratio [OR]: 3.7, 95% confidence interval [CI]: 1.3-10.2) was associated with higher QOC, and both Asian race (OR: 3.3, 95% CI: 1.2-9.0) and decompensated status (OR: 2.1, 95% CI: 1.1-4.2) were associated with receipt of HCC surveillance. A greater number of specialty care visits was not associated with higher QOC. Conclusion: Receipt of outpatient preventive cirrhosis QIs was variable and overall low in a diverse cohort of patients with cirrhosis. Variation in care by race/ethnicity and illness trajectory should prompt further inquiry into identifying modifiable factors to standardize care delivery and to improve QOC.

A Telephone and Mail Outreach Program Successfully Increases Uptake of Hepatocellular Carcinoma Surveillance

Hepatocellular carcinoma (HCC) is a leading cause of cancer‐related death worldwide. Society guidelines recommend surveillance with abdominal ultrasound with or without serum alpha‐fetoprotein every 6 months for adults at increased risk of developing HCC. However, adherence is often suboptimal. We assessed the feasibility of a coordinated telephone outreach program for unscreened patients with cirrhosis within the Veteran’s Affairs (VA) health care system. Using a patient care dashboard of advanced chronic liver disease in the VA Greater Los Angeles Healthcare System, we identified veterans with a diagnosis of cirrhosis, a platelet count ≤ 150,000/uL, and no documented HCC surveillance in the previous 8 months. Eligible veterans received a telephone call from a patient navigator to describe the risks and benefits of HCC surveillance. Orders for an abdominal ultrasound and alpha‐fetoprotein were placed for veterans who agreed to surveillance. Veterans who were not reached by telephone received an informational letter by mail to encourage participation. Of the 129 veterans who met the eligibility criteria, most were male (96.9%). The most common etiology for cirrhosis was hepatitis C (64.3%), and most of the patients had compensated cirrhosis (68.2%). The patient navigators reached 32.5% of patients by phone. Patients in each group were similar across clinical and demographic characteristics. Patients who were called were more likely to undergo surveillance (adjusted odds ratio = 2.56, 95% confidence interval: 1.03‐6.33). Most of the patients (72.1%) completed abdominal imaging when reached by phone. Conclusion: Targeted outreach increased uptake of HCC surveillance among patients with cirrhosis in a large, integrated, VA health care system.

Inflation of 430-parsec bipolar radio bubbles in the Galactic Centre by an energetic event

The Galactic Centre contains a supermassive black hole with a mass of four million Suns¹ within an environment that differs markedly from that of the Galactic disk. Although the black hole is essentially quiescent in the broader context of active galactic nuclei, X-ray observations have provided evidence for energetic outbursts from its surroundings². Also, although the levels of star formation in the Galactic Centre have been approximately constant over the past few hundred million years, there is evidence of increased short-duration bursts³, strongly influenced by the interaction of the black hole with the enhanced gas density present within the ring-like central molecular zone⁴ at Galactic longitude |l| < 0.7 degrees and latitude |b| < 0.2 degrees. The inner 200-parsec region is characterized by large amounts of warm molecular gas⁵, a high cosmic-ray ionization rate⁶, unusual gas chemistry, enhanced synchrotron emission^7,8, and a multitude of radio-emitting magnetized filaments⁹, the origin of which has not been established. Here we report radio imaging that reveals a bipolar bubble structure, with an overall span of 1 degree by 3 degrees (140 parsecs × 430 parsecs), extending above and below the Galactic plane and apparently associated with the Galactic Centre. The structure is edge-brightened and bounded, with symmetry implying creation by an energetic event in the Galactic Centre. We estimate the age of the bubbles to be a few million years, with a total energy of 7 × 10⁵² ergs. We postulate that the progenitor event was a major contributor to the increased cosmic-ray density in the Galactic Centre, and is in turn the principal source of the relativistic particles required to power the synchrotron emission of the radio filaments within and in the vicinity of the bubble cavities.

Initial experience of CT-guided pulsed radiofrequency ablation of the pudendal nerve for chronic recalcitrant pelvic pain

AIM

To evaluate initial experience with computed tomography (CT)-guided pulsed radiofrequency ablation (pRFA) of the pudendal nerve in cases of recalcitrant neuropathic pelvic pain. Endpoints include technical feasibility, safety, and efficacy of therapy.

MATERIALS AND METHODS

Ten patients who underwent pRFA ablation for neuropathic pudendal nerve pain during the trial period were followed for response to treatment for 6 months. Each patient was treated with pRFA under CT-guidance with concurrent perineural injection of anaesthetic and/or corticosteroid. Pain scores were then measured using a numeric rating scale at fixed intervals up to 6 months.

RESULTS

All procedures were considered technically successful with no immediate complications. pRFA demonstrated improved duration of pain improvement compared to the most recent perineural injection (p=0.0195), but not compared to the initial injection (p=0.64). Reported pain scores were lower with pRFA than with both the first and most recent injection but this did not reach statistical significance (p=0.1094 and p=0.7539, respectively).

CONCLUSION

Overall, pRFA of the pudendal nerve using CT-guidance can be a safe and effective therapy. This technique provides direct visualisation of the nerve to maximise safety and efficacy while offering a novel form of therapy for patients with chronic, recalcitrant pelvic pain.

Implementation of a Standardized Multimodal Postoperative Analgesia Protocol Improves Pain Control, Reduces Opioid Consumption, and Shortens Length of Hospital Stay After Posterior Lumbar Spinal Fusion

BACKGROUND

Multimodal analgesia regimens have been suggested to improve pain control and reduce opioid consumption after surgery.

OBJECTIVE

To institutionally implement an evidence-based quality improvement initiative to standardize and optimize pain treatment following neurosurgical procedures. Our goal was to objectively evaluate efficacy of this multimodal protocol.

METHODS

A retrospective cohort analysis of pain-related outcomes after posterior lumbar fusion procedures was performed. We compared patients treated in the 6 mo preceding (PRE) and 6 mo following (POST) protocol execution.

RESULTS

A total of 102 PRE and 118 POST patients were included. The cohorts were well-matched regarding sex, age, surgical duration, number of segments fused, preoperative opioid consumption, and baseline physical status (all P &gt; .05). Average patient-reported numerical rating scale pain scores significantly improved in the first 24 hr postoperatively (5.6 vs 4.5, P &lt; .001) and 24 to 72 hr postoperatively (4.7 vs 3.4, P &lt; .001), PRE vs POST, respectively. Maximum pain scores and time to achieving appropriate pain control also significantly improved during these same intervals (all P &lt; .05). A concomitant decrease in opioid consumption during the first 72 hr was seen (110 vs 71 morphine milligram equivalents, P = .02). There was an observed reduction in opioid-related adverse events per patient (1.31 vs 0.83, P &lt; .001) and hospital length of stay (4.6 vs 3.9 days, P = .03) after implementation of the protocol.

CONCLUSION

Implementation of an evidence-based, multimodal analgesia protocol improved postoperative outcomes, including pain scores, opioid consumption, and length of hospital stay, after posterior lumbar spinal fusion.

Progress in Confocal Laser Endomicroscopy for Neurosurgery and Technical Nuances for Brain Tumor Imaging With Fluorescein

Background: Previous studies showed that confocal laser endomicroscopy (CLE) images of brain tumors acquired by a first-generation (Gen1) CLE system using fluorescein sodium (FNa) contrast yielded a diagnostic accuracy similar to frozen surgical sections and histologic analysis. We investigated performance improvements of a second-generation (Gen2) CLE system designed specifically for neurosurgical use.

Methods: Rodent glioma models were used for in vivo and rapid ex vivo CLE imaging. FNa and 5-aminolevulinic acid were used as contrast agents. Gen1 and Gen2 CLE images were compared to distinguish cytoarchitectural features of tumor mass and margin and surrounding and normal brain regions. We assessed imaging parameters (gain, laser power, brightness, scanning speed, imaging depth, and Z-stack [3D image acquisition]) and evaluated optimal values for better neurosurgical imaging performance with Gen2.

Results: Efficacy of Gen1 and Gen2 was similar in identifying normal brain tissue, vasculature, and tumor cells in masses or at margins. Gen2 had smaller field of view, but higher image resolution, and sharper, clearer images. Other advantages of the Gen2 were auto-brightness correction, user interface, image metadata handling, and image transfer. CLE imaging with FNa allowed identification of nuclear and cytoplasmic contours in tumor cells. Injection of higher dosages of FNa (20 and 40 mg/kg vs. 0.1–8 mg/kg) resulted in better image clarity and structural identification. When used with 5-aminolevulinic acid, CLE was not able to detect individual glioma cells labeled with protoporphyrin IX, but overall fluorescence intensity was higher (p < 0.01) than in the normal hemisphere. Gen2 Z-stack imaging allowed a unique 3D image volume presentation through the focal depth.

Conclusion: Compared with Gen1, advantages of Gen2 CLE included a more responsive and intuitive user interface, collection of metadata with each image, automatic Z-stack imaging, sharper images, and a sterile sheath. Shortcomings of Gen2 were a slightly slower maximal imaging speed and smaller field of view. Optimal Gen2 imaging parameters to visualize brain tumor cytoarchitecture with FNa as a fluorescent contrast were defined to aid further neurosurgical clinical in vivo and rapid ex vivo use. Further validation of the Gen2 CLE for microscopic visualization and diagnosis of brain tumors is ongoing.

A Flow Cytometric Study of ER Stress and Autophagy

The mechanistic link between ER stress, autophagy, and resultant cell death was investigated by the use of drugs Thapsigargin (Tg) and Chloroquine (CQ) with prior induction and or blockade of autophagy and apoptosis which modulated the ER stress response and resultant form of cell death. All these biological processes can be measured flow cytometrically allowing the determination of the type of cell death, G₁ cell cycle arrest, cell cycle dependent measurement of ER stress transducer PERK, misfolded proteins, reticulophagy, and autophagy marker LC3B. Jurkat cells after Tg or CQ treatment became necrotic and apoptotic, showed G₁ cell cycle arrest, autophagy, and ER stress. Prior induction of autophagy before ER stress increased levels of necrotic and apoptotic cell death. Autophagy was further up-regulated, while PERK was reduced or abrogated. CQ showed reduced levels of misfolded proteins and reticulophagy, while Tg showed no change in misfolded protein levels but increased reticulophagy and thus displayed more ER stress. Prior blockade of apoptosis before induction of ER stress resulted in cell survival except with high Tg levels which induced necrosis. Autophagy was up-regulated with modulation of PERK and reticulophagy levels with an abrogation of the misfolded protein response. Blockade of apoptosis with induction of autophagy before ER stress showed death by necrosis with high dose drugs and cell survival with low doses of drugs. CQ induced reduced levels G₁ cell cycle arrest while it was maintained with Tg. Autophagy was also maintained with reduced levels of ER stress. These data demonstrates a profound link between the processes of ER stress, autophagy, and the resultant form of cell death all of which can be modulated depending upon the sequence and concentration of drugs employed. © 2018 International Society for Advancement of Cytometry.

Radiation Exposure Safety Patterns with the Use of Intraoperative Fluoroscopy

PURPOSE

To examine current practice patterns in occupational radiation safety by members of the American Society for Surgery of the Hand (ASSH) and to assess if these vary by surgeon demographics and experience.

METHODS

An online survey was sent to members of the ASSH and included 18 questions on fluoroscopy practice patterns as well as demographic information, including gender, years of experience, specialty, and geographic region. Multivariate logistic and multinomial regressions were used to determine predictors for fluoroscopy practice patterns while adjusting for these demographic factors.

RESULTS

904 surgeons (27%) responded to the study. The majority of surgeons preferred the mini C-arm for hand (91%) and elbow (70%) surgeries. Most did not use a personal dosimeter (70%). Forty-two percent of surgeons while using the mini C-arm did not use protective devices while only 5% of surgeons did not while using the standard C-arm. Women, surgeons with less than 10 years of experience, and responders in the western United States were the most likely to use protective devices.

CONCLUSIONS

Most surveyed surgeons do not monitor their radiation exposure, but the majority of surgeons utilize protective devices. We have identified groups that are most and least likely to comply with recommendations for proper radiation safety.

Probe-based three-dimensional confocal laser endomicroscopy of brain tumors: technical note

Background

Confocal laser endomicroscopy (CLE) is used during fluorescence-guided brain tumor surgery for intraoperative microscopy of tumor tissue with cellular resolution. CLE could augment and expedite intraoperative decision-making and potentially aid in diagnosis and removal of tumor tissue.

Objective

To describe an extension of CLE imaging modality that produces Z-stack images and three-dimensional (3D) pseudocolored volumetric images.

Materials and methods

Hand-held probe-based CLE was used to collect images from GL261-luc2 gliomas in C57BL/6 mice and from human brain tumor biopsies. The mice were injected with fluorescein sodium (FNa) before imaging. Patients received FNa intraoperatively, and biopsies were imaged immediately in the operating room. Some specimens were counterstained with acridine orange, acriflavine, or Hoechst and imaged on a benchtop confocal microscope. CLE images at various depths were acquired automatically, compiled, rendered into 3D volumes using Fiji software and reviewed by a neuropathologist and neurosurgeons.

Results

CLE imaging, Z-stack acquisition, and 3D image rendering were performed using 19 mouse gliomas and 31 human tumors, including meningiomas, gliomas, and pituitary adenomas. Volumetric images and Z-stacks provided additional information about fluorescence signal distribution, cytoarchitecture, and the course of abnormal vasculature.

Conclusion

3D and Z-stack CLE imaging is a unique new option for live intraoperative endomicroscopy of brain tumors. The 3D images afford an increased spatial understanding of tumor cellular architecture and visualization of related structures compared with two-dimensional images. Future application of specific fluorescent probes could benefit from this rapid in vivo imaging technology for interrogation of brain tumor tissue.

Diagnostic Accuracy of a Confocal Laser Endomicroscope for In Vivo Differentiation Between Normal Injured And Tumor Tissue During Fluorescein-Guided Glioma Resection: Laboratory Investigation

OBJECTIVE

Glioma resection with fluorescein sodium (FNa) guidance has a potential drawback of nonspecific leakage of FNa from nontumor areas with a compromised blood-brain barrier. We investigated the diagnostic accuracy of in vivo confocal laser endomicroscopy (CLE) after FNa administration to differentiate normal brain, injured normal brain, and tumor tissue in an animal glioma model.

METHODS

GL261-Luc2 gliomas in C57BL/6 mice were used as a brain tumor model. CLE images of normal, injured normal, and tumor brain tissues were collected after intravenous FNa administration. Correlative sections stained with hematoxylin and eosin were taken at the same sites. A set of 40 CLE images was given to 1 neuropathologist and 3 neurosurgeons to assess diagnostic accuracy and rate image quality (1-10 scale). Additionally, we developed a deep convolution neural network (DCNN) model for automatic image classification.

RESULTS

The mean observer accuracy for correct diagnosis of glioma compared with either injured or uninjured brain using CLE images was 85%, and the DCNN model accuracy was 80%. For differentiation of tumor from nontumor tissue, the experts' mean accuracy, specificity, and sensitivity were 90%, 86%, and 96%, respectively, with high interobserver agreement overall (Cohen κ = 0.74). The percentage of correctly identified images was significantly higher for images with a quality rating >5 (104/116, 90%) than for images with a quality rating ≤5 (32/44, 73%) (P = 0.007).

CONCLUSIONS

With sufficient FNa present in tissues, CLE was an effective tool for intraoperative differentiation among normal, injured normal, and tumor brain tissue. Clinical studies are warranted to confirm these findings.

Targeting the DNA Damage Response in OSCC with TP53 Mutations

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer worldwide and in the United States. OSCC remains a major cause of morbidity and mortality in patients with head and neck cancers. Tobacco and alcohol consumption alone or with chewing betel nut are potential risk factors contributing to the high prevalence of OSCC. Multimodality therapies, including surgery, chemotherapy, biologic therapy, and radiotherapy, particularly intensity-modulated radiotherapy (IMRT), are the current treatments for OSCC patients. Despite recent advances in these treatment modalities, the overall survival remains poor over the past years. Recent data from whole-exome sequencing reveal that TP53 is commonly mutated in human papillomavirus-negative OSCC patients. Furthermore, these data stressed the importance of the TP53 gene in suppressing the development and progression of OSCC. Clinically, TP53 mutations are largely associated with poor survival and tumor resistance to radiotherapy and chemotherapy in OSCC patients, which makes the TP53 mutation status a potentially useful molecular marker prognostic and predictive of clinical response in these patients. Several forms of DNA damage have been shown to activate p53, including those generated by ionizing radiation and chemotherapy. The DNA damage stabilizes p53 in part via the DNA damage signaling pathway that involves sensor kinases, including ATM and ATR and effector kinases, such as Chk1/2 and Wee1, which leads to posttranscriptional regulation of a variety of genes involved in DNA repair, cell cycle control, apoptosis, and senescence. Here, we discuss the link of TP53 mutations with treatment outcome and survival in OSCC patients. We also provide evidence that small-molecule inhibitors of critical proteins that regulate DNA damage repair and replication stress during the cell cycle progression, as well as other molecules that restore wild-type p53 activity to mutant p53, can be exploited as novel therapeutic approaches for the treatment of OSCC patients bearing p53 mutant tumors.

Closed therapy of thoracic and lumbar vertebral body fractures in trauma patients

Background

The failure rate for the closed/non-surgical treatment of thoracic and lumbar vertebral body fractures (TLVBF) in trauma patients has not been adequately evaluated utilizing computed tomography (CT) studies.

Methods

From 2007 to 2008, consecutive trauma patients, who met inclusion criteria, with a CT diagnosis of acute TLVBF undergoing closed treatment were assessed. The failure rates for closed therapy, at 3 months post-trauma, were defined by progressive deformity, vertebral body collapse, or symptomatic/asymptomatic pseudarthrosis. The Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification was utilized to classify the fractures (groups A1 and non-A1 fractures) and were successively followed with CT studies.

Results

There were 54 patients with 91 fractures included in the study; 66 were A1 fractures, and 25 were non-A1 fractures. All had rigid bracing applied with flat and upright X-ray films performed to rule out instability. None had sustained spinal cord injuries. Thirteen patients (24%) failed closed therapy [e.g. 13 failed fractures (14%) out of 91 total fractures]. Five failed radiographically only (asymptomatic), and eight failed radiographically and clinically (symptomatic). A1 fractures had a 4.5% failure rate, while non-A1 fractures failed at a rate of 40%.

Conclusion

Failure of closed therapy for TLVBF in the trauma population is not insignificant. Non-A1 fractures had a much higher failure rate when compared to A1 fractures. We recommend close follow-up particularly of non-A1 fractures treated in closed fashion using successive CT studies.

Palliative Care and Health Care Utilization for Patients With End-Stage Liver Disease at the End of Life

BACKGROUND & AIMS

There has been increased attention on ways to improve the quality of end-of-life care for patients with end-stage liver disease; however, there have been few reports of care experiences for patients during terminal hospitalizations. We analyzed data from a large national database to increase our understanding of palliative care for and health care utilization by patients with end-stage liver disease.

METHODS

We performed a cross-sectional, observational study to examine terminal hospitalizations of adults with decompensated cirrhosis using data from the National Inpatient Sample from 2009 through 2013. We collected data on palliative care consultation and total hospital costs, and performed multivariate regression analyses to identify factors associated with palliative care consultation. We also investigated whether consultation was associated with lower costs.

RESULTS

Among hospitalized adults with terminal decompensated cirrhosis, 30.3% received palliative care; the mean cost per hospitalization was $48,551 ± $1142. Palliative care consultation increased annually, and was provided to 18.0% of patients in 2009 and to 36.6% of patients in 2013 (P < .05). The mean cost for the terminal hospitalization did not increase significantly ($47,969 in 2009 to $48,956 in 2013, P = .77). African Americans, Hispanics, Asians, and liver transplant candidates were less likely to receive palliative care, whereas care in large urban teaching hospitals was associated with a higher odds of receiving consultation. Palliative care was associated with lower procedure burden-after adjusting for other factors, palliative care was associated with a cost reduction of $10,062.

CONCLUSIONS

Palliative care consultation for patients with end-stage liver disease increased from 2009 through 2013. Palliative care consultation during terminal hospitalizations is associated with lower costs and procedure burden. Future research should evaluate timing and effects of palliative care on quality of end-of-life care in this population.

Effect of fiber blends, total solids, heat treatment, whey protein concentrate and stage of sugar incorporation on dietary fiber-fortified Kheer

Owing to the proven beneficial role of dietary fiber (DF) on human health, feasibility of incorporating commercially available soluble and insoluble DF preparations into rice-milk-pudding (kheer, a popular Indian delicacy) was studied through process modification. The novel approach of preparing reduced fat DF-fortified-kheer (DFFK) by developing liquid/cream phase and particulate/rice phase separately, and subsequently blending the two was developed. The major processing variables studied were total solids (TS) in the liquid phase, type of fiber blend, flavor-simulation through heat treatment or added whey protein, and the presence of sugar in water for pre-cooking of rice. Reduced fat DFFK made from three different pre-standardized fiber blends was quite acceptable to the sensory panel (overall rating 7.5). With increasing TS in milk up to 16.5%, sensory acceptability of DFFK increased. There was a small but perceivable improvement in the flavour of DFFK when precooking of rice was carried out in sweetened water. Reduced fat DFFK from different fiber blends was found to be reasonably close to conventional kheer. DFFK prepared from Blend-I provided 3.31 g dietary fiber/100 kcal (suitable for the claim "High-in-Fiber") with 38.71% Reduced-Fat. With the developed process of fortification of kheer with DF, it is possible to reduce fat (and thus calories) to cater to the needs of consumers seeking good health.

Apparent diffusion coefficient maps in the assessment of surgical patients with lumbar spine degeneration

Purpose

To assess the utility of apparent diffusion coefficient (ADC) maps for the assessment of patients with advanced degenerative lumbar spine disease and describe characteristic features of ADC maps in various degenerative lumbar spinal conditions.

Methods

T1-weighted, T2-weighted and diffusion weighted (DWI) MR images of 100 consecutive patients admitted to the spinal surgery service were assessed. ADC maps were generated from DWI images using Osyrix software. The ADC values and characteristic ADC maps were assessed in the regions of interest over the different pathological entities of the lumbar spine.

Results

The study included 452 lumbar vertebral segments available for analysis of ADCs. Characteristic ADC map features were identified for protrusion, extrusion and sequester types of lumbar disk herniations, spondylolisthesis, reactive Modic endplate changes, Pfirrmann grades of IVD degeneration, and compromised spinal nerves. Compromised nerve roots had significantly higher mean ADC values than adjacent (p < 0.001), contralateral (p < 0.001) or adjacent contralateral (p < 0.001) nerve roots. Compared to the normal bone marrow, Modic I changes showed higher ADC values (p = 0.01) and Modic 2 changes showed lower ADC values (p = 0.02) respectively. ADC values correlated with the Pfirrmann grading, however differed from herniated and non-herniated disks of the matched Pfirrmann 3 and 4 grades.

Conclusion

Quantitative and qualitative evaluation of ADC mapping may provide additional useful information regarding the fluid dynamics of the degenerated spine and may complement standard MRI imaging protocol for the comprehensive assessment of surgical patients with lumbar spine pathology. ADC maps were advantageous in differentiating reactive bone marrow changes, and more precise assessment of the disk degeneration state. ADC mapping of compressed nerve roots showed promise but requires further investigation on a larger cohort of patients.

The role of therapeutic hypothermia in the management of acute spinal cord injury

This review paper investigates the history, efficacy, and administration of systemic and local hypothermia for spinal cord injury (SCI). It summarizes the published experimental and clinical evidence on hypothermia for SCI and analyzes the potential for further research. Early experimental animal research showed that local hypothermia improved recovery and gain of function after acute SCI. However, in the early 1970s, clinical research findings did not coincide with results of these animal trials, which led to a loss of interest in local hypothermia. Since the 1980s, systemic hypothermia has been successfully used to treat SCI in both animals and humans. An abundance of positive evidence suggests that clinical trials are needed to determine the effectiveness of hypothermia for SCI. As a first step, we investigated the published clinical and experimental evidence on the use of hypothermia for SCI patients, who have few available treatment options. We searched PubMed for English-language reports published from 1940 to 2016 containing terms related to SCI treatment using hypothermia. We reviewed all articles on local hypothermia and acute SCI or on systemic hypothermia and acute SCI. Bibliographies of retrieved publications were also screened for additional citations. Ninety-six papers were selected. The clinical use of hypothermia is most successful if applied according to certain optimized parameters (e.g., duration, temperature, time from injury to initiation of cooling, and rewarming time). Preliminary data suggest that modest systemic hypothermia applied for 48h provides the best therapeutic value, but the parameters for use of local hypothermia vary greatly. Experimental evidence and some clinical evidence suggest that both local hypothermia and systemic hypothermia are beneficial for acute SCI. Future research should focus on defining the optimal levels of parameters. Large, multicenter, controlled clinical trials are needed to investigate its therapeutic potential.

Manganese-enhanced MRI Offers Correlation with Severity of Spinal Cord Injury in Experimental Models

BACKGROUND

Spinal cord injuries (SCI) are clinically challenging, because neural regeneration after cord damage is unknown. In SCI animal models, regeneration is evaluated histologically, requiring animal sacrifice. Noninvasive techniques are needed to detect longitudinal SCI changes.

OBJECTIVE

To compare manganese-enhanced magnetic resonance imaging (MRI [MEMRI]) in hemisection and transection of SCI rat models with diffusion tensor imaging (DTI) and histology.

METHODS

Rats underwent T9 spinal cord transection (n=6), hemisection (n=6), or laminectomy without SCI (controls, n=6). One-half of each group received lateral ventricle MnCl₂ injections 24 hours later. Conventional DTI or T1-weighted MRI was performed 84 hours post-surgery. MEMRI signal intensity ratio above and below the SCI level was calculated. Fractional anisotropy (FA) measurements were taken 1 cm rostral to the SCI. The percentage of FA change was calculated 10 mm rostral to the SCI epicenter, between FA at the dorsal column lesion normalized to a lateral area without FA change. Myelin load (percentage difference) among groups was analyzed by histology.

RESULTS

In transection and hemisection groups, mean MEMRI ratios were 0.62 and 0.87, respectively, versus 0.99 in controls (P<0.001 and P<0.001, respectively); mean FA decreases were 67.5% and 40.1%, respectively, compared with a 6.1% increase in controls (P=0.002 and P=0.019, respectively). Mean myelin load decreased by 38.8% (transection) and 51.8% (hemisection) compared to controls (99.1%) (P<0.001 and P<0.001, respectively). Pearson's correlation coefficients were -0.94 for MEMRI ratio and FA changes and 0.87 for MEMRI and myelin load.

CONCLUSION

MEMERI results correlated to SCI severity measured by FA and myelin load. MEMRI is a useful noninvasive tool to assess neuronal damage after SCI.

Genetic Alterations in Intervertebral Disc Disease

BACKGROUND

Intervertebral disc degeneration (IVDD) is considered a multifactorial disease that is influenced by both environmental and genetic factors. The last two decades of research strongly demonstrate that genetic factors contribute about 75% of the IVDD etiology. Recent total genome sequencing studies have shed light on the various single-nucleotide polymorphisms (SNPs) that are associated with IVDD.

AIM

This review presents comprehensive and updated information about the diversity of genetic factors in the inflammatory, degradative, homeostatic, and structural systems involved in the IVDD. An organized collection of information is provided regarding genetic polymorphisms that have been identified to influence the risk of developing IVDD. Understanding the proteins and signaling systems involved in IVDD can lead to improved understanding and targeting of therapeutics.

MATERIALS AND METHODS

An electronic literature search was performed using the National Library of Medicine for publications using the keywords genetics of IVDD, lumbar disc degeneration, degenerative disc disease, polymorphisms, SNPs, and disc disease. The articles were then screened based on inclusion criteria that included topics that covered the correlation of SNPs with developing IVDD. Sixty-five articles were identified as containing relevant information. Articles were excluded if they investigated lower back pain or just disc herniation without an analysis of disc degeneration. This study focuses on the chronic degeneration of IVDs.

RESULTS

Various genes were identified to contain SNPs that influenced the risk of developing IVDD. Among these are genes contributing to structural proteins, such as COL1A1, COL9A3, COL9A3, COL11A1, and COL11A2, ACAN, and CHST3. Furthermore, various SNPs found in the vitamin-D receptor gene are also associated with IVDD. SNPs related to inflammatory cytokine imbalance are associated with IVDD, although some effects are limited by sex and certain populations. SNPs in genes that code for extracellular matrix-degrading enzymes, such as MMP-1, MMP-2, MMP-3, MMP-9, MMP-14, ADAMTS-4, and ADAMTS-5 are also associated with IVDD. Apoptosis-mediating genes, such as caspase 9 gene (CASP9), TRAIL, and death receptor 4 (DR4), as well as those for growth factors, such as growth differentiation factor 5 and VEGF, are identified to have polymorphisms that influence the risk of developing IVDD.

CONCLUSION

Within the last 10 years, countless new SNPs have been identified in genes previously unknown to be associated with IVDD. Furthermore, the last decade has also revealed new SNPs identified in genes already known to be involved with increased risk of developing IVDD. Improved understanding of the numerous genetic variants behind various pathophysiological elements of IVDD could help advance personalized care and pharmacotherapeutic strategies for patients suffering from IVDD in the future.

The Role of microRNA Markers in the Diagnosis, Treatment, and Outcome Prediction of Spinal Cord Injury

Spinal cord injury (SCI) is a devastating condition that affects many people worldwide. Treatment focuses on controlling secondary injury cascade and improving regeneration. It has recently been suggested that both the secondary injury cascade and the regenerative process are heavily regulated by microRNAs (miRNAs). The measurement of specific biomarkers could improve our understanding of the disease processes, and thereby provide clinicians with the opportunity to guide treatment and predict clinical outcomes after SCI. A variety of miRNAs exhibit important roles in processes of inflammation, cell death, and regeneration. These miRNAs can be used as diagnostic tools for predicting outcome after SCI. In addition, miRNAs can be used in the treatment of SCI and its symptoms. Significant laboratory and clinical evidence exist to show that miRNAs could be used as robust diagnostic and therapeutic tools for the treatment of patients with SCI. Further clinical studies are warranted to clarify the importance of each subtype of miRNA in SCI management.

Determination of relationship between sensory viscosity rating and instrumental flow behaviour of soluble dietary fibers

The shear-thinning low, medium and high-viscosity fiber preparations (0.15-1.05 % psyllium husk, 0.07-0.6 % guar gum, 0.15-1.20 % gum tragacanth, 0.1-0.8 % gum karaya, 0.15-1.05 % high-viscosity Carboxy Methyl Cellulose and 0.1-0.7 % xanthan gum) showed that the consistency coefficient (k) was a function of concentration, the relationship being exponential (R(2), 0.87-0.96; P < 0.01). The flow behaviour index (n) (except for gum karaya and CMC) was exponentially related to concentration (R(2), 0.61-0.98). The relationship between k and sensory viscosity rating (SVR) was essentially linear in nearly all cases. The SVR could be predicted from the consistency coefficient using the regression equations developed. Also, the relationship of k with fiber concentration would make it possible to identify the concentration of a particular gum required to have desired consistency in terms of SVR.