Multi-parametric Photoacoustic Imaging Combined with Acoustic Radiation Force Impulse Imaging for Applications in Tissue Engineering.

Tissue engineering is a dynamic field focusing on the creation of advanced scaffolds for tissue and organ regeneration. These scaffolds are customized to their specific applications and are often designed to be complex, large structures to mimic tissues and organs. This study addresses the critical challenge of effectively characterizing these thick, optically opaque scaffolds that traditional imaging methods fail to fully image due to their optical limitations. We introduce a novel multi-modal imaging approach combining ultrasound, photoacoustic, and acoustic radiation force impulse imaging. This combination leverages its acoustic-based detection to overcome the limitations posed by optical imaging techniques. Ultrasound imaging is employed to monitor the scaffold structure, photoacoustic imaging is employed to monitor cell proliferation, and acoustic radiation force impulse imaging is employed to evaluate the homogeneity of scaffold stiffness. We applied this integrated imaging system to analyze melanoma cell growth within silk fibroin protein scaffolds with varying pore sizes and therefore stiffness over different cell incubation periods. Among various materials, silk fibroin was chosen for its unique combination of features including biocompatibility, tunable mechanical properties, and structural porosity which supports extensive cell proliferation. The results provide a detailed mesoscale view of the scaffolds' internal structure, including cell penetration depth and biomechanical properties. Our findings demonstrate that the developed multimodal imaging technique offers comprehensive insights into the physical and biological dynamics of tissue-engineered scaffolds. As the field of tissue engineering continues to advance, the importance of non-ionizing and non-invasive imaging systems becomes increasingly evident, and by facilitating a deeper understanding and better characterization of scaffold architectures, such imaging systems are pivotal in driving the success of future tissue-engineering solutions.

Investigating the Obesity Paradox in Colorectal Cancer: An Analysis of Prospectively Collected Data in a Diverse Cohort.

BACKGROUND: Prior studies are inconclusive regarding the effect of obesity on mortality in persons with colorectal cancer (CRC). We sought to determine the association of pre-diagnosis body mass index (BMI) trajectories on mortality after CRC diagnosis. METHODS: Utilizing the Multiethnic Cohort, we included adults aged 18-75 between 1 January 1993 and 1 January 2019 with a diagnosis of CRC and at least three available BMIs. The primary exposure, BMI, was subjected to group-based trajectory modeling (GBTM). We evaluated all-cause and CRC-specific mortality, using Cox proportional hazard (PH) models. RESULTS: Of 924 persons, the median age was 60 years, and 54% were female. There was no statistically significant association between pre-cancer BMI trajectory and either all-cause or cancer-specific mortality. In competing risk analysis, the risk of CRC-specific mortality was higher for African Americans (HR = 1.56, 95% CI [1.00-2.43], p = 0.048) and smokers (HR = 1.59, 95% CI [1.10-2.32], p = 0.015). Risk of all-cause mortality was higher for Hawaiian persons (HR = 2.85, 95% CI [1.31-6.21], p = 0.009) and persons with diabetes (HR = 1.83, 95% CI [1.08-3.10], p = 0.026). CONCLUSIONS: Pre-diagnosis BMI trajectories were not associated with mortality after CRC diagnosis, whereas race/ethnicity, diabetes, and smoking were associated with an increased risk of death. Our findings suggest the obesity paradox alone does not account for mortality after CRC diagnosis.

Set Up and Utilization of a Three-Dimensional In Vitro Bioreactor System for Human Intestinal Studies and Microbial Co-Cultures.

The study of human intestinal physiology and host-microbe interactions is crucial for understanding gastrointestinal health and disease. Traditional two-dimensional cell culture models lack the complexity of the native intestinal environment, limiting their utility in studying intestinal biology. Here, we present a detailed protocol for the set up and utilization of a three-dimensional (3D) in vitro bioreactor system for human intestinal studies and bacterial co-culture. This article outlines the design and assembly of the bioreactor system, scaffold fabrication, bacterial culture techniques, analysis methods, and troubleshooting tips. By providing step-by-step instructions, the goal is to enable other laboratories to utilize physiologically relevant tissue models of the human intestine, incorporating key features, such as nutrient flow, multiple human cell types, 3D architecture, and microbial communities. The incorporation of commensal bacteria into the bioreactor system allows for the investigation of complex host-microbe interactions, providing insight into gastrointestinal health and pathology. This article serves as a comprehensive resource for scientists seeking to advance their understanding of intestinal biology toward the development of novel therapeutic strategies for gastrointestinal disorders. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Scaffold design Basic Protocol 2: Intestinal cell culture: Caco2 cells Basic Protocol 3: Intestinal cell culture: organoids Basic Protocol 4: Bioreactor design and set up Basic Protocol 5: Bacteria in 3D bioreactor set up Basic Protocol 6: Bacteria and drug dosing.

Perfused In Vitro Intestine Tissue Model to Evaluate the Role of Stromal and Immune Cells in Epithelial Response to Inflammatory Cues and Drug Therapies.

We establish an in vitro perfusion intestinal tissue bioreactor system tailored to study drug responses related to inflammatory bowel disease (IBD). The system includes key components including multiple human intestinal cell types (colonoids, myofibroblasts, and macrophages), a three-dimensional (3D) intestinal architecture, and fluid flow. Inclusion of myofibroblasts resulted in increased secretion of cytokines such as glypican-1 (GCP-1), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin 1-α (IL-1α), whereas inclusion of macrophages resulted in increased secretion of monocyte chemoattractant proteins (MCPs) demonstrating a significant role of both stromal and immune cell types in intestinal inflammation. The system is responsive to drug treatments, as reflected in the reduction of pro-inflammatory cytokine production in tissue in some treatment scenarios. While future studies are needed to evaluate more nuanced responses in an IBD context, the present study demonstrates the ability to establish a 3D intestinal model with multiple relevant cell types and flow that is responsive to both inflammatory cues and various drug treatment options.

Multi-modal, Label-free, Optical Mapping of Cellular Metabolic Function and Oxidative Stress in 3D Engineered Brain Tissue Models.

Brain metabolism is essential for the function of organisms. While established imaging methods provide valuable insights into brain metabolic function, they lack the resolution to capture important metabolic interactions and heterogeneity at the cellular level. Label-free, two-photon excited fluorescence imaging addresses this issue by enabling dynamic metabolic assessments at the single-cell level without manipulations. In this study, we demonstrate the impact of spectral imaging on the development of rigorous intensity and lifetime label-free imaging protocols to assess dynamically over time metabolic function in 3D engineered brain tissue models comprising human induced neural stem cells, astrocytes, and microglia. Specifically, we rely on multi-wavelength spectral imaging to identify the excitation/emission profiles of key cellular fluorophores within human brain cells, including NAD(P)H, LipDH, FAD, and lipofuscin. These enable development of methods to mitigate lipofuscin's overlap with NAD(P)H and flavin autofluorescence to extract reliable optical metabolic function metrics from images acquired at two excitation wavelengths over two emission bands. We present fluorescence intensity and lifetime metrics reporting on redox state, mitochondrial fragmentation, and NAD(P)H binding status in neuronal monoculture and triculture systems, to highlight the functional impact of metabolic interactions between different cell types. Our findings reveal significant metabolic differences between neurons and glial cells, shedding light on metabolic pathway utilization, including the glutathione pathway, OXPHOS, glycolysis, and fatty acid oxidation. Collectively, our studies establish a label-free, non-destructive approach to assess the metabolic function and interactions among different brain cell types relying on endogenous fluorescence and illustrate the complementary nature of information that is gained by combining intensity and lifetime-based images. Such methods can improve understanding of physiological brain function and dysfunction that occurs at the onset of cancers, traumatic injuries and neurodegenerative diseases.

Cell-cultivated aquatic food products: emerging production systems for seafood.

The demand for fish protein continues to increase and currently accounts for 17% of total animal protein consumption by humans. About 90% of marine fish stocks are fished at or above maximum sustainable levels, with aquaculture propagating as one of the fastest growing food sectors to address some of this demand. Cell-cultivated seafood production is an alternative approach to produce nutritionally-complete seafood products to meet the growing demand. This cellular aquaculture approach offers a sustainable, climate resilient and ethical biotechnological approach as an alternative to conventional fishing and fish farming. Additional benefits include reduced antibiotic use and the absence of mercury. Cell-cultivated seafood also provides options for the fortification of fish meat with healthier compositions, such as omega-3 fatty acids and other beneficial nutrients through scaffold, media or cell approaches. This review addresses the biomaterials, production processes, tissue engineering approaches, processing, quality, safety, regulatory, and social aspects of cell-cultivated seafood, encompassing where we are today, as well as the road ahead. The goal is to provide a roadmap for the science and technology required to bring cellular aquaculture forward as a mainstream food source.

The Association Between Angiotensin-Converting Enzyme Inhibitor or Angiotensin Receptor Blocker Exposure and Key Cirrhosis-Related Outcomes.

INTRODUCTION: Angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARB) may have hepatic benefits in patients with primarily chronic liver disease. ACE-I/ARB have not been evaluated in broad cohorts inclusive of those with decompensated cirrhosis. We analyzed the real-world association between ACE-I/ARB exposure and cirrhosis-related outcomes in a national cohort. METHODS: We performed a retrospective, active comparator new user study of patients with cirrhosis in the Veterans Health Administration. We identified new initiators of ACE-I/ARB or calcium channel blockers (comparator). Inverse probability treatment weighting balanced key confounders and Cox regression evaluated the association between ACE-I/ARB and outcomes of mortality, cirrhosis decompensation, and hepatocellular carcinoma (HCC). In exploratory analysis, cause-specific competing risk models evaluated liver-related vs cardiovascular (CV)-related vs nonliver/non-CV-related mortality. RESULTS: There were 904 ACE-I/ARB and 352 calcium channel blocker new initiators. In inverse probability treatment weighting Cox regression, ACE-I/ARB exposure was associated with reduced mortality (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.61-0.81, P < 0.001). In patients with compensated cirrhosis, ACE-I/ARB were not associated with hepatic decompensation or HCC. Cause-specific hazard models showed ACE-I/ARB exposure was associated with reduction in nonliver/non-CV-related mortality (cause-specific HR 0.49, 95% CI 0.38-0.62, P < 0.001) but not liver-related or CV-related mortality. In Child-Turcotte-Pugh A patients, ACE-I/ARB were associated with decreased CV-related mortality (cause-specific HR 0.41, 95% CI 0.26-0.65, P < 0.001). DISCUSSION: ACE-I/ARB exposure was associated with reduced mortality, potentially through CV and other (renal, malignancy-related) mechanisms. In patients with compensated disease, ACE-I/ARB were not associated with hepatic decompensation or HCC. Future research should identify subsets of patients who benefit from ACE-I/ARB exposure.

Chemical and sensory analyses of cultivated pork fat tissue as a flavor enhancer for meat alternatives.

The emerging field of cellular agriculture has accelerated the development of cell-cultivated adipose tissue as an additive to enhance the flavor of alternative meat products. However, there has been limited research to evaluate the sensory profile of in vitro-grown tissues compared to conventionally obtained animal fat. This study aimed to investigate the aromatic characteristics of cell-cultivated fat tissue as a flavor enhancer for meat alternatives. Porcine dedifferentiated fat (PDFAT) cells were clonally isolated and differentiated into adipocytes. This cultured adipose tissue was then analyzed alongside native porcine fat using gas chromatography-mass spectrometry (GC/MS) coupled with descriptive sensory analysis by human consumers. This evaluation enabled quantitative and qualitative assessments of volatile compounds released during cooking for both in vitro and in vivo porcine fats. The volatile profiles generated during the cooking process and fatty aroma characteristics reported by sensory consumers were largely similar between the two fat sources, with some differences in select compounds and aroma attributes. Ultimately, the consumers found comparable overall liking scores reported between the conventional and cultured porcine fats. These findings provide valuable sensory evidence supporting the viability of cell-cultivated adipose tissue as a flavor component of meat alternatives, substituting for conventional animal fat.

Sensorimotor Challenges in Minimally Invasive Surgery: A Theoretically-Oriented Review.

OBJECTIVE: This review surveys the literature on sensorimotor challenges impacting performance in laparoscopic minimally invasive surgery (MIS). BACKGROUND: Despite its well-known benefits for patients, achieving proficiency in MIS can be challenging for surgeons due to many factors including altered visual perspectives and fulcrum effects in instrument handling. Research on these and other sensorimotor challenges has been hindered by imprecise terminology and the lack of a unified theoretical framework to guide research questions in the field. METHOD: We conducted a systematic survey of the MIS literature, focusing on studies investigating sensorimotor challenges affecting laparoscopic performance. To provide a common foundation for cross-study comparisons, we propose a standardized taxonomy that distinguishes between different experimental paradigms used in the literature. We then show how the computational motor learning perspective provides a unifying theoretical framework for the field that can facilitate progress and motivate future research along clearer, hypothesis-driven lines. RESULTS: The survey identified diverse sensorimotor perturbations in MIS, which can be effectively categorized according to our proposed taxonomy. Studies investigating monitor-, camera-, and tool-based perturbations were systematically analyzed, elucidating their impact on surgical performance. We also show how the computational motor learning perspective provides deeper insights and potential strategies to mitigate challenges. CONCLUSION: Sensorimotor challenges significantly impact MIS, necessitating a systematic, empirically informed approach. Our proposed taxonomy and theoretical framework shed light on the complexities involved, paving the way for more structured research and targeted training approaches to enhance surgical proficiency. APPLICATION: Understanding the sensorimotor challenges inherent to MIS can guide the design of improved training curricula and inform the configuration of setups in the operating room to enhance surgeon performance and ultimately patient outcomes. This review offers key insights for surgeons, educators, and researchers in surgical performance and technology development.

Screening for Hepatocellular Carcinoma and Survival in Patients With Cirrhosis After Hepatitis C Virus Cure.

Importance: The risk of hepatocellular carcinoma (HCC) declines over time after hepatitis C virus (HCV) cure by direct-acting antiviral (DAA) therapies. Liver society guidelines recommend continuing HCC screening for these patients, but data on screening outcomes are lacking. Objective: To evaluate the association of HCC screening after HCV cure with overall survival. Design, Setting, and Participants: This cohort study evaluated patients with HCV cirrhosis who achieved DAA-induced HCV cure in the Veterans Affairs health care system between January 2014 and December 2022. Data analysis occurred from October 2023 to January 2024. Exposures: The percentage of time spent up to date with recommended HCC screening was calculated by year of follow-up and during the 4 years preceding HCC diagnosis (the detectable asymptomatic phase). Main Outcomes and Measures: The primary outcome was overall survival after HCC diagnosis and was compared by percentage of time spent up to date with screening using Kaplan-Meier analyses and Cox proportional hazards regression. Early-stage HCC at diagnosis and curative treatment were secondary outcomes assessed using logistic regression. Results: A total of 16 902 individuals were included (median [IQR] age, 64.0 [60.5-67.4] years; 16 426 male [97.2%]), of whom 1622 developed HCC. The cumulative incidence of HCC declined from 2.4% (409 of 16 902 individuals) to 1.0% (27 of 2833 individuals) from year 1 to year 7 of follow-up. Being up to date with screening for at least 50% of time during the 4 years preceding HCC diagnosis was associated with improved overall survival (log-rank test of equality over strata P = .002). In multivariate analysis, each 10% increase in follow-up spent up to date with screening was associated with a 3.2% decrease in the hazard of death (hazard ratio, 0.97; 95% CI, 0.95-0.99). There was a statistically significant interaction between time since HCV cure and screening, with no association observed among those who received a diagnosis of HCC more than 5 years after HCV cure. Each 10% of time spent up to date with screening was associated with a 10.1% increased likelihood of diagnosis with early-stage HCC (95% CI, 6.3%-14.0%) and a 6.8% increased likelihood of curative treatment (95% CI, 2.8%-11.0%). Conclusions and Relevance: In this cohort study of persons with HCV-related cirrhosis who achieved HCV cure and subsequently developed HCC, remaining up to date with screening was associated with improved overall survival, supporting the screening of eligible individuals.

Clinical and genetic risk factors for progressive fibrosis in metabolic dysfunction-associated steatotic liver disease.

BACKGROUND: Fibrosis-4 (FIB4) is a recommended noninvasive test to assess hepatic fibrosis among patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we used FIB4 trajectory over time (ie, "slope" of FIB4) as a surrogate marker of liver fibrosis progression and examined if FIB4 slope is associated with clinical and genetic factors among individuals with clinically defined MASLD within the Million Veteran Program Cohort. METHODS: In this retrospective cohort study, FIB4 slopes were estimated through linear regression for participants with clinically defined MASLD and FIB4 <2.67 at baseline. FIB4 slope was correlated with demographic parameters and clinical outcomes using logistic regression and Cox proportional hazard models. FIB4 slope as a quantitative phenotype was used in a genome-wide association analysis in ancestry-specific analysis and multiancestry meta-analysis using METAL. RESULTS: FIB4 slopes, generated from 98,361 subjects with MASLD (16,045 African, 74,320 European, and 7996 Hispanic), showed significant associations with sex, ancestry, and cardiometabolic risk factors (p < 0.05). FIB4 slopes also correlated strongly with hepatic outcomes and were independently associated with time to cirrhosis. Five genetic loci showed genome-wide significant associations (p < 5 × 10-8) with FIB4 slope among European ancestry subjects, including 2 known (PNPLA3 and TM6SF2) and 3 novel loci (TERT 5.1 × 10-11; LINC01088, 3.9 × 10-8; and MRC1, 2.9 × 10-9). CONCLUSIONS: Linear trajectories of FIB4 correlated significantly with time to progression to cirrhosis, with liver-related outcomes among individuals with MASLD and with known and novel genetic loci. FIB4 slope may be useful as a surrogate measure of fibrosis progression.

Cell-based fish production case study for developing a food safety plan.

Given the expanding global population and finite resources, it is imperative to explore alternative technologies for food production. These technologies play a crucial role in ensuring the provision of safe, nutritious, and sustainable food options to meet the growing demand. Cellular agriculture plays an important in developing an alternative method for developing food products. While, cellular agriculture is emerging rapidly, food safety aspects and regulatory frameworks stayed behind. Despite developing several regulatory framework papers on cellular agriculture, there is no systematic approach for developing a comprehensive food safety plan (FSP), particularly for cultivated seafood. Thus, the overall goal of this article is to develop a FSP for cultivated seafood. The main differences between the food safety plan for cultivated seafood and the conventional seafood industries were the number of allergens in cultivated seafood products, including soy, wheat, and fish cells, compared to only fish for the conventional seafood industry. In addition, there are several hazards associated with mycoplasma in cultivated seafood, which should be considered. This guidance intends to help regulatory agencies, food safety experts, startup companies, and the cultivated seafood industry by providing a valuable platform to develop regulations, guidance, and food safety plans applicable to most cultivated seafood companies. This article will also help the industry to identify the hazards in their processing line and develop preventive controls, and as a comprehensive food safety plan, it could be easily adapted for other cultivated seafood products. This guidance applied systematic approaches to developing food safety plans using cell culture, pharmaceuticals, fermentation, seafood, meat, and aquaponics safety plans, collaborating with experts with different backgrounds, and working closely with the conventional and cultivated meat and seafood industries.

Methods to Screen the Adhesion of Fish Cells on Plant-, Algal- and Fungal-Derived Biomaterials.

Cellular agriculture, an alternative and innovative approach to sustainable food production, has gained momentum in recent years. However, there is limited research into the production of cultivated seafood. Here, we investigated the ability of fish mackerel cells (Scomber scombrus) to adhere to plant, algal and fungal-based biomaterial scaffolds, aiming to optimize the cultivation of fish cells for use in cellular agriculture. A mackerel cell line was utilized, and metabolic assays and confocal imaging were utilized to track cell adhesion, growth, and differentiation on the different biomaterials. The mackerel cells adhered and grew on gelatin (positive control), zein, and soy proteins, as well as on alginate, chitosan, and cellulose polysaccharides. The highest adhesion and growth were on the zein and chitosan substrates, apart from the gelatin control. These findings provide a blueprint to enhance scaffold selection and design, contributing to the broader field of cellular agriculture through the development of scalable and eco-conscious solutions for meeting the growing global demand for seafood.

Safety of naltrexone in patients with cirrhosis.

Background & Aims: Treatment of alcohol use disorder (AUD) improves survival in patients with alcohol-related cirrhosis. However, medications for alcohol use disorder (MAUD) are underutilized in this population, partially due to concerns regarding drug-induced liver injury (DILI). Our aim was to evaluate the safety of naltrexone in patients with cirrhosis. Methods: This was a retrospective study of patients with cirrhosis who were prescribed naltrexone using the VOCAL (Veterans Outcomes and Costs Associated with Liver Disease) database. Patients with new initiation of naltrexone after diagnosis of cirrhosis who had liver enzymes checked within a 3-month time frame were included. A chart review was performed on patients who developed alanine aminotransferase or alkaline phosphatase elevations to more than 2× or 5× the upper limit of normal, respectively. The RUCAM (Roussel Uclaf causality assessment method) was used to determine if DILI occurred. Results: A total of 3,285 patients with cirrhosis were initiated on naltrexone, of whom 2,940 had laboratory testing during the high-risk DILI period. Only 2% of patients had liver enzyme elevations, and among those, 30 (48%) were classified as "DILI excluded" and 32 (52%) were classified as "DILI unlikely". No patients were classified as possible, probable, or highly probable DILI. No deaths or new decompensations were attributed to naltrexone. Conclusions: Naltrexone in patients with cirrhosis was not associated with development of DILI using RUCAM scoring. Naltrexone appears to be safe in patients with compensated and decompensated cirrhosis. Impact and Implications: Naltrexone is an effective medication for treating alcohol use disorder but is underutilized in patients with underlying liver disease due to historical concerns regarding hepatotoxicity. This retrospective study shows no drug-induced liver injury in a large cohort of patients with cirrhosis with new initiation of naltrexone. This study may encourage providers to prescribe naltrexone to patients with existing liver disease with ongoing alcohol use disorder.

Silk fibroin catheter with stable bioinspired inner-surfaces for inhibition of bioadhesion.

Biofilm formation on indwelling medical devices such as catheters and ventilators due to the adhesion of bacteria poses significant challenges in healthcare. Surface modification with micro- and nano-structures offers a promising strategy to prevent bioadhesion and is safer than surface chemical modification approaches. Here, catheters were prepared using silk fibroin (SF) hydrogels and an infusion molding method, with the inner surface featuring a micropapillae structure inspired by lotus leaves (SF-CMP). After phenylethanol (PEA) fumigation treatment, the resulting catheters (SF-CMP PEA) displayed improved swelling resistance and mechanical properties compared to methanol-treated catheters (SF-CMP MeOH). PEA was more efficient than methanol in controlling the size, distribution, and content of silk crystalline ß-sheet blocks and thus the swelling and mechanical properties. Moreover, the micro-papillae structure on SF-CMP PEA remained stable over 35 days in solution, in contrast to SF-CMP MeOH, which lasted <7 days. SF-CMP PEA exhibited repellent effects against E. coli and S. aureusin vitro, and low cytotoxicity to the endothelial cells cultured on the unpatterned surface. Additionally, subcutaneous implantation studies showed reduced inflammation around the micropatterned samples compared to controls with a plain, unpatterned surface. The unique properties of SF-based materials, including tunable structures, biocompatibility, degradation, and drug-loading capability make them an attractive material for anti-bioadhesion in applications ranging from indwelling medical devices to tissue engineering scaffolds.

Evaluating the Mechanical Strength of Three Dimensionally (3D) Printed Implants in Septorhinoplasty through Finite Element Analysis (FEA).

BACKGROUND: Autologous nasoseptal cartilage grafts are used to correct nasal asymmetry and deviation in rhinoplasty, but patients who have undergone multiple surgeries may have limited autologous cartilage tissue available. 3D-printed L-strut implants may address these challenges in the future, but their mechanical strength is understudied. Silk fibroin-gelatin (SFG), polycaprolactone (PCL), and polylactide (PLA) are bio-inks known for their strength. We present Finite Element Analysis (FEA) models comparing the mechanical strength of 3D-printed SFG, PCL, and PLA implants with nasoseptal cartilage grafts when autologous or allografts are not available. METHODS: FEA models compared the stress and deformation responses of 3D-printed solid and scaffold implant replacements to cartilage. To simulate a daily force from overlying soft tissue, a unidirectional load was applied at the "keystone" region given its structural role and compared with native cartilaginous properties. RESULTS: 3D-printed solid SFG, PCL, and PLA and scaffold PCL and PLA models demonstrated lower deformations compared to cartilage. Solid SFG balanced strength and flexibility. The maximum stress was below all materials' yield stresses suggesting their deformations are unlikely permanent under a daily load. CONCLUSIONS: Our FEA models suggest that 3D-printed L-strut implants carry promising mechanical strength. Solid SFG's results mimicked cartilage's mechanical behavior. Thus, scaffold SFG merits further geometric optimization for potential use for cartilage substitution. 3D-printed septal cartilage replacement implants can potentially enhance surgical management of patients who lack available donor cartilage in select settings. CLINICAL RELEVANCE STATEMENT: Computational simulations can evaluate 3D-printed implant strength and their potential to replace septal cartilage in septorhinoplasty.

Preoperative Hepatology and Primary Care Visits Improve Postoperative Outcomes in Patients with Cirrhosis Undergoing Surgery.

BACKGROUND AND AIMS: Cirrhosis patients are at increased risk for postoperative complications. It remains unclear whether preoperative nonsurgical clinician visits improve postoperative outcomes. We assessed the impact of preoperative primary care physician (PCP) and/or gastroenterologist/hepatologist (GI/Hep) visits on postoperative mortality in cirrhosis patients undergoing surgery and explored differences in medication changes and paracentesis rates as potential mediators. METHODS: This was a retrospective cohort study of cirrhosis patients in the Veterans Health Administration who underwent surgery between 2008 and 2016. We compared 1982 patients with preoperative PCP and/or GI/Hep visits with 1846 propensity-matched patients without preoperative visits. We used Cox regression and Fine and Gray competing risk regression to evaluate the association between preoperative visit type and postoperative mortality at 6 months. RESULTS: Patients with preoperative GI/Hep and PCP visits had a 45% lower hazard of postoperative mortality compared with those without preoperative visits (hazard ratio [HR], 0.55; 95% confidence interval [CI], 0.35-0.87). A smaller effect size was noted with GI/Hep preoperative visit alone (HR, 0.69; 95% CI, 0.48-0.99) or PCP visit alone (HR, 0.70; 95% CI, 0.53-0.93). Patients with preoperative PCP/GI/Hep visits were more likely to have diuretics, spontaneous bacterial peritonitis prophylaxis, and hepatic encephalopathy medications newly initiated and/or dose adjusted and more likely to receive preoperative paracentesis as compared with those without preoperative visits. CONCLUSIONS: Preoperative PCP/GI/Hep visits are associated with a reduced risk of postoperative mortality with the greatest risk reduction observed in those with both PCP and GI/Hep visits. This synergistic effect highlights the importance of a multidisciplinary approach in the preoperative care of cirrhosis patients.