Objective radiologic assessment of body composition in patients with end-stage liver disease: going beyond the BMI. Transplantation. 2013;95:617-622. [PMID: 23348896 DOI: 10.1097/tp.0b013e31827a0f27]

Multilabel segmentation and analysis of skeletal muscle and adipose tissue in routine abdominal CT scans

PURPOSE

This paper presents a deep learning-based multi-label segmentation network that extracts a total of three separate adipose tissues and five different muscle tissues in CT slices of the third lumbar vertebra and additionally improves the segmentation of the intermuscular fat.

METHOD

Based on a self-created data set of 130 patients, an extended Unet structure was trained and evaluated with the help of Dice score, IoU and Pixel Accuracy. In addition, the interobserver variability for the decision between ground truth and post-processed segmentation was calculated to illustrate the relevance in everyday clinical practice.

RESULTS

On average, the presented approach achieved 91.0±0.065% DSC for the muscle tissues and 88.9±0.062% DSC for the adipose tissues. It was shown that by post-processing the intermuscular fat tissue, physicians prefer the result of the algorithm presented in the paper to their segmentation by 91.51%.

CONCLUSION

The algorithm provided more precise segmentations of muscles and adipose tissue, demonstrating high-quality performance in segmenting muscle tissue. In qualitative evaluations, physicians preferred the algorithm's segmentation over expert segmentations, with the preference quantified as 91.51%. This indicates that, based on their assessment, the algorithm's results were significantly favored. This qualitative feedback supports the algorithm's use in subsequent analyses of patient fitness, leveraging the detailed information it provides.

Computed tomography-measured body composition can predict long-term outcomes for stage I-III colorectal cancer patients

Background

There remains a pressing need to identify biomarkers capable of reliably predicting prognostic outcomes for colorectal cancer (CRC) patients. As several body composition parameters have recently been reported to exhibit varying levels of prognostic significance in particular cancers, the present study was devised to assess the ability of body composition to predict long-term outcomes for CRC patients with different stages of disease.

Methods

In total, this retrospective analysis enrolled 327 stage I-III CRC patients whose medical records were accessed for baseline demographic and clinical data. Primary outcomes for these patients included disease-free and overall survival (DFS and OS). The prognostic performance of different musculature, visceral, and subcutaneous fat measurements from preoperative computed tomography (CT) scans was assessed.

Results

Over the course of follow-up, 93 of the enrolled patients experienced recurrent disease and 39 died. Through multivariate Cox regression analyses, the visceral/subcutaneous fat area (V/S) ratio was found to be independently associated with patient DFS (HR=1.93, 95% CI: 1.24-3.01, P=0.004), and the skeletal muscle index (SMI) as an independent predictor for OS (HR=0.43, 95% CI: 0.21-0.89, P=0.023). Through subgroup analyses, higher V/S ratios were found to be correlated with reduced DFS among patients with stage T3/4 (P=0.011), lymph node metastasis-positive (P=0.002), and TNM stage III (P=0.002) disease, whereas a higher SMI was associated with better OS in all T stages (P=0.034, P=0.015), lymph node metastasis-positive cases (P=0.020), and in patients with TNM stage III disease (P=0.020).

Conclusion

Both the V/S ratio and SMI offer potential utility as clinical biomarkers associated with long-term CRC patient prognosis. A higher V/S ratio and a lower SMI are closely related to poorer outcomes in patients with more advanced disease.

Anaesthesia management for liver transplantation: A narrative review

Orthotopic liver transplantation is the definitive standard treatment for end-stage liver disease. Orthotopic liver transplantation anaesthesia management is a complex procedure that requires a multidisciplinary team approach. Understanding the complex pathophysiology of end-stage liver disease and its complications in the affected systems is essential for proper anaesthesia management in orthotopic liver transplantation. Orthotopic liver transplantation is a dynamic process, and preoperative optimisation is essential in these patients. Therefore, anaesthesiologists should focus on rapidly fluctuating physiology, haemodynamics, metabolic, and coagulation status in the anaesthesia management of these patients. Perioperative care and anaesthesia for orthotopic liver transplantation can be divided into preoperative evaluation, anaesthesia induction and management, dissection, anhepatic, neo-hepatic, and postoperative care, with essential anaesthetic considerations at each point. Considering the clinical situation, haemodynamic changes, misapplications, knowledge, attitude, and multimodal and multidisciplinary approach are vital in anaesthesia and the perioperative period. In our review, in line with the literature, we aimed to present the perioperative and anaesthesia management in orthotopic liver transplantation patients.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Nutrition support management of organ transplant recipients in the acute posttransplant phase

Patients who undergo solid organ transplant can have an extensive and challenging postoperative course. The chronicity of the disease state prior to transplant in combination with transplant-specific complications and immunosuppressant medications can lead to distinct challenges that are not observed in other critically ill patients. Although the manifestation of posttransplant complications may be specific to the organ being transplanted, there are common transplant challenges that affect nutrition therapy in these patients. Effects of malnutrition, metabolic aberrations, and posttransplant organ dysfunction should be considered when developing a nutrition care plan for patients in the immediate posttransplant phase. This article addresses the various complications that can arise in the immediate posttransplant phase among patients undergoing solid organ transplant and the appropriate nutrition interventions or considerations for this specialized patient population.

Association between skeletal muscle index prior to liver transplantation and 1-year mortality posttransplant

BACKGROUND

Liver transplantation is the only curative therapy for end-stage liver disease (ESLD). Sarcopenia is often defined as the loss of muscle quantity (skeletal muscle index [SMI]), but muscle attenuation (MA), a surrogate marker of muscle quality, is also decreased in ESLD. We assessed pre-liver transplant SMI and MA and their association with posttransplant mortality, complications, and length of intensive care unit (ICU) and hospital stay.

METHODS

In 169 consecutive patients with ESLD who underwent a liver transplantation between 2007 and 2014, SMI and MA were measured on computed tomography scans at time of placement on the waiting list for liver transplantation. The primary outcome of interest was 1-year posttransplant mortality. Secondary posttransplantation outcomes of interest were complications within 30 days and length of stay in the ICU > 3 days and in the hospital >3 weeks. Logistic and Cox regression analyses were performed.

RESULTS

MA was associated with 1-year posttransplant mortality rate (hazard ratio=0.656, 95% CI=0.464-0.921, P = 0.015). The highest quartile of SMI had a lower odds for the total length of stay in the hospital lasting >3 weeks (odds ratio=0.211, 95% CI=0.061-0.733, P = 0.014). MA was associated with a prolonged ICU stay; this was, however, not statistically significant after adjustment for age, sex, and Model for ESLD score.

CONCLUSION

Lower MA is associated with a longer length of ICU stay and 1-year mortality after liver transplantation, whereas low SMI was associated with a total length of hospital stay.

Malnutrition, sarcopenia, and cancer cachexia in gynecologic cancer

Patients with gynecologic cancers are at risk for malnutrition, cancer cachexia, and sarcopenia. Accumulating data supports that malnourished patients with gynecologic cancer have worse overall survival, increased healthcare utilization and costs, and a higher incidence of postoperative complications and treatment toxicity than those who are not malnourished. Malnutrition is defined as insufficient energy intake, leading to altered body composition and subsequent impaired physical and cognitive function, and can result in sarcopenia and cachexia, defined as the loss of lean body mass and loss of body weight respectively. The etiology of cancer-related malnutrition is complex, resulting from a systemic pro-inflammatory state of malignancy with upregulation of muscle degradation pathways and metabolic derangements, including lipolysis and proteolysis, that may not respond to nutritional repletion alone. Numerous validated scoring systems and radiographic measures have been described to define and quantify the severity of malnutrition and muscle loss in both clinical and research settings. "Prehabilitation" and optimization of nutrition and functional status early in therapy may combat the development or worsening of malnutrition and associated syndromes and ultimately improve oncologic outcomes, but limited data exist in the context of gynecologic cancer. Multi-modality nutrition and physical activity interventions have been proposed to combat the biophysical losses related to malnutrition. Several trials are underway in gynecologic oncology patients to address these aims, but significant gaps in knowledge persist. Pharmacologic interventions and potential immune targets for combating cachexia related to malignancy are discussed in this review and may provide opportunities to target disease and cachexia. This article reviews currently available data regarding the implications, diagnostics, physiology, and intervention strategies for gynecologic oncology patients with malnutrition and its associated conditions.

Associations of subcutaneous fat area and Systemic Immune-inflammation Index with survival in patients with advanced gastric cancer receiving dual PD-1 and HER2 blockade

BACKGROUND

Systemic Immune-inflammation Index (SII) and body composition parameters are easily assessed, and can predict overall survival (OS) in various cancers, allowing early intervention. This study aimed to assess the correlation between CT-derived body composition parameters and SII and OS in patients with advanced gastric cancer receiving dual programmed death-1 (PD-1) and human epidermal growth factor receptor 2 (HER2) blockade.

MATERIALS AND METHODS

This retrospective study enrolled patients with advanced gastric cancer treated with dual PD-1 and HER2 blockade from March 2019 to June 2022. We developed a deep learning model based on nnU-Net to automatically segment skeletal muscle, subcutaneous fat and visceral fat at the third lumbar level, and calculated the corresponding Skeletal Muscle Index, skeletal muscle density, subcutaneous fat area (SFA) and visceral fat area. SII was computed using the formula that total peripheral platelet count×neutrophil/lymphocyte ratio. Univariate and multivariate Cox regression analysis were used to determine the associations between SII, body composition parameters and OS.

RESULTS

The automatic segmentation deep learning model was developed to efficiently segment body composition in 158 patients (0.23 s/image). Multivariate Cox analysis revealed that high SII (HR=2.49 (95% CI 1.54 to 4.01), p<0.001) and high SFA (HR=0.42 (95% CI 0.24 to 0.73), p=0.002) were independently associated with OS, whereas sarcopenia was not an independent prognostic factor for OS (HR=1.41 (95% CI 0.86 to 2.31), p=0.173). In further analysis, patients with high SII and low SFA had worse long-term prognosis compared with those with low SII and high SFA (HR=8.19 (95% CI 3.91 to 17.16), p<0.001).

CONCLUSION

Pretreatment SFA and SII were significantly associated with OS in patients with advanced gastric cancer. A comprehensive analysis of SII and SFA may improve the prognostic stratification of patients with gastric cancer receiving dual PD-1 and HER2 blockade.

Association between Abdominal CT Measurements of Body Composition before Deceased Donor Liver Transplant with Posttransplant Outcomes

Background Pre-liver transplant (LT) sarcopenia is associated with poor survival. Methods exist for measuring body composition with use of CT scans; however, it is unclear which components best predict post-LT outcomes. Purpose To quantify the association between abdominal CT-based body composition measurements and post-LT mortality in a large North American cohort. Materials and Methods This was a retrospective cohort of adult first-time deceased-donor LT recipients from 2009 to 2018 who underwent pre-LT abdominal CT scans, including at the L3 vertebral level, at Johns Hopkins Hospital. Measurements included sarcopenia (skeletal muscle index [SMI] <50 in men and <39 in women), sarcopenic obesity, myosteatosis (skeletal muscle CT attenuation <41 mean HU for body mass index [BMI] <25 and <33 mean HU for BMI ≥25), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and VAT/SAT ratio. Covariates in the adjusted models were selected with use of least absolute shrinkage and selection operator regression with lambda chosen by means of 10-fold cross-validation. Cox proportional hazards models were used to quantify associations with post-LT mortality. Model discrimination was quantified using the Harrell C-statistic. Results A total of 454 recipients (median age, 57 years [IQR, 50-62 years]; 294 men) were evaluated. In the adjusted model, pre-LT sarcopenia was associated with a higher hazard ratio (HR) of post-LT mortality (HR, 1.6 [95% CI: 1.1, 2.4]; C-statistic, 0.64; P = .02). SMI was significantly negatively associated with survival after adjustment for covariates. There was no evidence that myosteatosis was associated with mortality (HR, 1.3 [95% CI: 0.86, 2.1]; C-statistic, 0.64; P = .21). There was no evidence that BMI (HR, 1.2 [95% CI: 0.95, 1.4]), VAT (HR, 1.0 [95% CI: 0.98, 1.1]), SAT (HR, 1.0 [95% CI: 0.97, 1.0]), and VAT/SAT ratio (HR, 1.1 [95% CI: 0.90, 1.4]) were associated with mortality (P = .15-.77). Conclusions Sarcopenia, as assessed on routine pre-liver transplant (LT) abdominal CT scans, was the only factor significantly associated with post-LT mortality. © RSNA, 2022 See also the editorial by Ruehm in this issue.

Deep learning body-composition analysis of clinically acquired CT-scans estimates creatinine excretion with high accuracy in patients and healthy individuals

Assessment of daily creatinine production and excretion plays a crucial role in the estimation of renal function. Creatinine excretion is estimated by creatinine excretion equations and implicitly in eGFR equations like MDRD and CKD-EPI. These equations are however unreliable in patients with aberrant body composition. In this study we developed and validated equations estimating creatinine production using deep learning body-composition analysis of clinically acquired CT-scans. We retrospectively included patients in our center that received any CT-scan including the abdomen and had a 24-h urine collection within 2 weeks of the scan (n = 636). To validate the equations in healthy individuals, we included a kidney donor dataset (n = 287). We used a deep learning algorithm to segment muscle and fat at the 3rd lumbar vertebra, calculate surface areas and extract radiomics parameters. Two equations for CT-based estimate of RenAl FuncTion (CRAFT 1 including CT parameters, age, weight, and stature and CRAFT 2 excluding weight and stature) were developed and compared to the Cockcroft-Gault and the Ix equations. CRAFT1 and CRAFT 2 were both unbiased (MPE = 0.18 and 0.16 mmol/day, respectively) and accurate (RMSE = 2.68 and 2.78 mmol/day, respectively) in the patient dataset and were more accurate than the Ix (RMSE = 3.46 mmol/day) and Cockcroft-Gault equation (RMSE = 3.52 mmol/day). In healthy kidney donors, CRAFT 1 and CRAFT 2 remained unbiased (MPE = − 0.71 and − 0.73 mmol/day respectively) and accurate (RMSE = 1.86 and 1.97 mmol/day, respectively). Deep learning-based extraction of body-composition parameters from abdominal CT-scans can be used to reliably estimate creatinine production in both patients as well as healthy individuals. The presented algorithm can improve the estimation of renal function in patients who have recently had a CT scan. The proposed methods provide an improved estimation of renal function that is fully automatic and can be readily implemented in routine clinical practice.

Sarcopenia defined by psoas muscle index independently predicts long-term survival after living donor liver transplantation in male recipients

Background

The effect of sarcopenia on long-term outcomes in recipients after living donor liver transplantation (LDLT), including overall survival and hepatocellular carcinoma (HCC) recurrence, remains unclear, especially in China.

Methods

From 2009 to 2015, 117 adult patients underwent LDLT in our center. In all, 82 patients who had computed tomography images reaching the third lumbar vertebra level within 1 month of LDLT were included; 70 male patients were included in the final analysis after excluding 12 female patients because of poor performance of the calculated cutoff value. Sarcopenia was defined according to the psoas muscle index (PMI) cutoff value, which was calculated based on dynamic time-dependent outcomes using X-tile software. Cox proportional hazards models were used to assess multivariate-adjusted hazards ratios (HRs) to seek potential correlations between sarcopenia and posttransplant outcomes.

Results

According to the cutoff value of PMI (6.25 cm²/m²), 38 patients (54.3%) were diagnosed with sarcopenia. After an average of 63.3 months of follow-up, 21 patients died after LDLT, 16 in the sarcopenia group and 5 in the non-sarcopenia group, respectively. Sarcopenia was identified as being significantly associated with worse posttransplant overall survival in multivariate analysis, resulting in an HR of 3.22 [95% confidence interval (CI), 1.15-8.98]. Among the 50 recipients with HCC, sarcopenia was significantly associated with HCC recurrence in univariate analysis (HR 2.87, 95% CI, 1.06-7.80) but was not detected as an independent risk factor of HCC recurrence in multivariate analysis, although a trend (tendency)towards significance was observed (HR 2.60, 95% CI, 0.95-7.10; P=0.062).

Conclusions

Sarcopenia defined by PMI is a feasible and reliable independent predictor of posttransplant overall survival in male LDLT candidates. However, its correlation with posttransplant HCC recurrence remains uncertain.

Sarcopenia adversely impacts postoperative complications in living-donor liver transplantation recipients

Despite technological and immunological innovations, living-donor liver transplant (LDLT) recipients still face substantial risk of postoperative complications. Sarcopenia is being recognized more and more as a biomarker that correlates with poor outcomes in surgical patients. The purpose of this study was to evaluate the relationship between sarcopenia and significant surgical complications in LDLT recipients. This retrospective review included patients who had received LDLT at our institute from 2005 to 2017. Sarcopenia was assessed using the psoas muscle index (PMI) in cross-sectional images. ROC curve analysis was used to determine the ability of PMI to predict postoperative complications. Correlations between major postoperative complications and sarcopenia were evaluated using regression analysis. A total of 271 LDLT recipients were included. No significant differences were found between PMI and major postoperative complications in male patients. Female recipients with major postoperative complications had significantly lower mean PMI values (P = 0.028), and the PMI cut-off value was 2.63 cm²/m². Postoperative massive pleural effusion requiring pigtail drainage occurred more frequently in the sarcopenia group than in the non-sarcopenia group (P = 0.003). 1-, 3-, 5- and 10-year overall survival rates in female were significantly poorer in the sarcopenia group (n = 14) compared with the non-sarcopenia group (n = 108), at 92.9% versus 97.2%, 85.7% versus 95.4%, 85.7% versus 92.5% and 70.1 versus 82.0%, respectively (P = 0.041) and 94.6%, 89.9%, 85.9% and 78.5% in male patients. Sarcopenia is associated with a significantly higher risk of major postoperative complications in females. PMI and sarcopenia together are predictive of major postoperative complications and survival rates in female LDLT recipients.

MRI-Derived Sarcopenia Associated with Increased Mortality Following Yttrium-90 Radioembolization of Hepatocellular Carcinoma

PURPOSE

To evaluate the influence of sarcopenia on survival in patients with hepatocellular carcinoma (HCC) treated with ⁹⁰Y radioembolization.

MATERIALS AND METHODS

This single-center retrospective cohort study analyzed 82 consecutive patients (65 men and 17 women, mean age 65 years, range 31-83 years) with HCC treated with ⁹⁰Y radioembolization between December 2013 and December 2017. Sarcopenia was assessed on pre-procedure MRI performed within 100 days prior to ⁹⁰Y radioembolization by segmenting the paraspinal musculature at the level of the superior mesenteric artery origin and subtracting fat-intensity pixels to yield fat-free muscle area (FFMA). Sarcopenia was defined as FFMA ≤31.97 cm² for men and ≤28.95 cm² for women. Survival at 90 days, 180 days, 1 year, and 3 years following initial treatment was assessed using medical and public obituary records.

RESULTS

Sarcopenia was identified in 30% (25/82) of patients. Death was reported for 49% (32/65) of males and 71% (8/17) of females (mean follow-up 19.6 months, range 21 days-58 months). Patients with sarcopenia were found to have increased mortality at 180 days (31.8% vs. 8.9%) and 1 year (68.2% vs. 21.2%). Sarcopenia was an independent predictor of mortality adjusted for BCLC stage and sub-analysis demonstrated that sarcopenia independently predicted increased mortality for patients with BCLC stage B disease.

CONCLUSION

Sarcopenia was associated with increased 180-day and 1-year mortality in HCC patients undergoing ⁹⁰Y radioembolization. Sarcopenia was an independent predictor of survival adjusted for BCLC stage with significant deviation in the survival curves of BCLC stage B patients with and without sarcopenia.

Sarcopenia in Children With End-Stage Liver Disease on the Transplant Waiting List

Sarcopenia predicts morbidity and mortality in adults with end-stage liver disease (ESLD) and is determined by total psoas muscle area (tPMA) measurement from computed tomography (CT) imaging. Recently developed pediatric age- and sex-specific tPMA growth curves provide the opportunity to ascertain prevalence and impact of sarcopenia in children awaiting liver transplantation (LT). This retrospective single-center study evaluated sarcopenia in children between 1 and 16 years with ESLD and a clinically indicated abdominal CT less than 3 months before first isolated LT. Sarcopenia was defined as tPMA z score less than -2 measured at the intervertebral L4-5 level. Patient demographic, biochemical, and outcome data were recorded. tPMA was compared with other measures of nutritional status using univariate and multivariate logistic analyses. Outcome measures included 1-year morbidity events and mortality after LT. CT images from 25 (64% female) children with median age of 5.50 (interquartile range [IQR], 3.75-11.33) years were reviewed. Ten children (40%) had a tPMA z score less than -2. Sarcopenia was associated with lower z scores for weight (odds ratio [OR], 0.38; P = 0.02), height (OR, 0.32; P = 0.03), and nutritional support before LT (OR, 12.93; P = 0.01). Sarcopenic children had a longer duration of pediatric intensive care unit (PICU) stay (3.50 [IQR, 3.00-6.00] versus 2.00 [IQR, 2.00-3.50] days; P = 0.03). Sarcopenia was prevalent in 40% of children with ESLD awaiting LT, and lower tPMA z score was associated with deficient anthropometrics and need for nutritional support before LT. Post-LT PICU duration was increased in children with sarcopenia, reflecting adverse outcomes associated with muscle loss. Further studies are needed to elucidate the underlying mechanisms of sarcopenia in children with ESLD.

Both muscle quantity and quality are predictors of waiting list mortality in patients with end-stage liver disease

BACKGROUND AND AIMS

Malnutrition is highly prevalent in patients with end-stage liver disease (ESLD) and associated with impaired clinical outcome. Previous studies focused on one component of body composition and not in combination with nutritional intake, while both are components of the nutritional status. We aimed to evaluate the most important risk factors regarding body composition (muscle mass, muscle quality and fat mass) and nutritional intake (energy and protein intake) for waiting list mortality in patients with ESLD awaiting liver transplantation (LTx).

METHODS

Consecutive patients with ESLD listed for LTx between 2007 and 2014 were investigated. Muscle mass quantity (Skeletal Muscle Mass Index, SMI), and muscle quality (Muscle Attenuation, MA), and various body fat compartments were measured on computed tomography using SliceOmatic. Nutritional intake (e.g. energy and protein intake) was assessed. Multivariable stepwise forward Cox regression analysis was used for statistical analysis.

RESULTS

261 Patients (mean age 54 years, 74.7% male) were included. Low SMI and MA were found to be statistically significant predictors of an increased risk for waiting list mortality in patients with ESLD, with a HR of 2.580 (95%CI 1.055-6.308) and HR of 9.124 (95%CI 2.871-28.970), respectively. No association between percentage adipose tissue, and protein and energy intake with waiting list mortality was found in this study.

CONCLUSION

Both low muscle quantity and quality, and not nutritional intake, were independent risk factors for mortality in patients with ESLD.

Obesity Management of Liver Transplant Waitlist Candidates and Recipients

Obesity is increasing in prevalence in liver transplant candidates and recipients. The rise in liver transplantation for nonalcoholic steatohepatitis reflects this increase. Management of obesity in liver transplant candidates can be challenging due to the presence of decompensated cirrhosis and sarcopenia. Obesity may increase peritransplant morbidity but does not have an impact on long-term post-transplant survival. Bariatric surgery may be a feasible option in select patients before, during, or after liver transplantation. Use of weight loss drugs and/or endoscopic therapies for obesity management ultimately may play a role in liver transplant patients, but more research is needed to determine safety.

Inner Abdominal Fat and Psoas Muscle as Predictive Factors for the Outcome After Liver Transplant

OBJECTIVES

We analyzed the nutritional condition of liver transplant recipients and the body mass index, the inner abdominal fat tissue, the outer abdominal fat tissue, the psoas muscle size, and the psoas muscle index of the recipients and evaluated the effects of these factors on patient outcomes after liver transplant.

MATERIALS AND METHODS

We included recipients of liver transplants from January 2009 to December 2018 who had computed tomography at our center < 3 months before transplant. Preoperative, intraoperative, and postoperative data were evaluated. Outer abdominal fat tissue, inner abdominal fat tissue, and psoas muscle area were measured on the computed tomography abdominal images. We used univariate and multi-variate regression analyses to evaluate the data.

RESULTS

There were 265 patients; mean age was 54 years (SD, 13 years). The mean value for body mass index, calculated as weight in kilograms divided by height in meters squared, was 25 (SD, 5). The mean score for Model for End-Stage Liver Disease was 17 (SD, 6). All patients underwent orthotopic liver transplant by standard technique. After adjustment for multivariable analysis, the values for psoas muscle size and the psoas muscle index of the recipient were associated as independent factors for postoperative complications and duration of hospital stay. The survival rate at 1 year was 78.5%, and the rate of perioperative mortality was 16.6%. Independent factors associated with survival after liver transplant were inner abdominal fat tissue, etiology, and rate of major postoperative complications.

CONCLUSIONS

Inner abdominal fat tissue, psoas muscle size, and the psoas muscle index are significantly associated with postoperative complications and/or survival after liver transplant. Our results suggest that these prognostic factors may be useful to optimize the selection of appropriate candidates for liver transplant.

The Impact of Obesity in End of Life Care in Patients With End Stage Liver Disease: An Observational Study

BACKGROUND

Both obesity and end stage liver disease (ESLD) are increasing. Obesity's impact on hospice and palliative care in patients with ESLD is unknown.

METHODS

We retrospectively evaluated patients admitted to an academic, Midwestern, tertiary center between January 2016 and May 2019 with a diagnosis of ESLD. Body Mass Index and MELD Na were calculated for each patient's first admission during the study period. Patients with MELD Na scores ≥ 21 or 18-20 with additional criteria were considered potentially eligible for hospice and palliative care referrals.

RESULTS

Of 3863 patients admitted with ESLD, 1556 (40%) were potentially eligible for hospice and palliative care referrals. Of these, 703 (45%) were obese. Comorbidity burden was higher in obese patients (15.6% of obese patients had a Charlson Comorbidity Index ≥ 5, while 5% of non-obese patients had a comorbidity index of ≥ 5 (p < 0.001). Referral rates to hospice and palliative services in obese patients were 10.1% and 16.4% respectively. Hospice and palliative referral rates among non-obese patients were similar (10.1% and 15.5%). Among patients who died within 6 months of the first hospitalization, the mean time to referral to hospice or palliative care from index admission was longer in obese patients.

CONCLUSION

Obesity is common in patients hospitalized with ESLD who may be approaching the end of life. Referral rates to hospice and palliative care services are low and similar regardless of BMI and despite higher co-morbidity burdens in obese patients. Obesity may delay referrals to hospice and palliative care.

Feasibility of Serial Ultrasound Measurements of the Rectus Femoris Muscle Area to Assess Muscle Loss in Patients Awaiting Liver Transplantation in the Intensive Care Unit

End-stage liver disease (ESLD) patients requiring intensive care unit (ICU) care before liver transplantation (LT) often experience significant muscle mass loss, which has been associated with mortality. In this exploratory study, we primarily aimed to assess the feasibility of serial ultrasound (US) rectus femoris muscle area (RFMA) measurements for the evaluation of progressive muscle loss in ICU-bound potential LT candidates and describe the rate of muscle loss as assessed by sequential US RFMA measurements. Secondarily, we sought to identify patient characteristics associated with muscle loss and determine how muscle loss is associated with survival.

Sarcopenia Is Associated With Development of Acute-on-Chronic Liver Failure in Decompensated Liver Cirrhosis Receiving Transjugular Intrahepatic Portosystemic Shunt

Muscle mass has been shown to be a prognostic marker in patients with liver cirrhosis. Transversal psoas muscle thickness normalized by height (TPMT/height) obtained by routine computed tomography is a simple surrogate parameter for sarcopenia. TPMT/height, however, is not sex specific, which might play a role in risk stratification. Its association with acute-on-chronic liver failure (ACLF) has not been established yet. ACLF is associated with systemic inflammatory dysregulation. This study aimed at evaluating the role of sarcopenia in ACLF development of patients with decompensated cirrhosis receiving transjugular intrahepatic portosystemic shunt (TIPS) using sex-specific TPMT/height.

Approaches to Assessment of Muscle Mass and Myosteatosis on Computed Tomography: A Systematic Review

BACKGROUND/OBJECTIVE

There is increasing use of computed tomography (CT) in sarcopenia research using a wide variety of techniques. We performed a systematic review of the CT literature to identify the differences between approaches used.

METHODS

A comprehensive search of PubMed from 1983 to 2017 was performed to identify studies that used CT muscle measurements to assess muscle mass and myosteatosis. The CT protocols were evaluated based on anatomic landmark(s), thresholding, muscle(s) segmented, key measurement (ie, muscle attenuation, cross-sectional area, volume), derived variables, and analysis software. From the described search, 657 articles were identified and 388 studies met inclusion criteria for this systematic review.

RESULTS

Muscle mass was more commonly assessed than myosteatosis (330 vs. 125). The most commonly assessed muscle or muscle groups were total abdominal wall musculature (142/330 and 49/125 for muscle mass and myosteatosis, respectively) and total thigh musculature (90/330 and 48/125). The most commonly used landmark in the abdomen was the L3 vertebra (123/142 and 45/49 for muscle mass and myosteatosis, respectively). Skeletal muscle index and intermuscular adipose tissue were the most commonly used measures of abdominal wall muscle mass (114/142) and myosteatosis (27/49), respectively. Cut points varied across studies. A significant majority of studies failed to report important CT technical parameters, such as use of intravenous contrast and slice thickness (94% and 63%, respectively).

CONCLUSIONS

There is considerable variation in the CT approaches used for the assessment of muscle mass and myosteatosis. There is a need to develop consensus for CT-based evaluation of sarcopenia and myosteatosis.

Preoperative Assessment of Muscle Mass Using Computerized Tomography Scans to Predict Outcomes Following Orthotopic Liver Transplantation

BACKGROUND

Sarcopenia is an established risk factor predicting survival in chronically ill and trauma patients. We herein examine the assessment and clinical implication of sarcopenia in liver transplantation (LT).

METHODS

Computerized tomography scans from 172 patients waitlisted for LT were analyzed by applying 6 morphometric muscle scores, including 2 density indices (psoas density [PD] and skeletal muscle density [SMD]) and 4 scores based on muscle area (total psoas area, psoas muscle index, skeletal muscle area, and skeletal muscle index).

RESULTS

The prevalence of sarcopenia in our cohort ranged from 7.0% to 37.8%, depending on the score applied. Only sarcopenia as defined by the density indices PD and SMD (but not total psoas area, psoas muscle index, skeletal muscle area, or skeletal muscle index) revealed clinical relevance since it correlates significantly with postoperative complications (≥Grade III, Clavien-Dindo classification) and sepsis. Furthermore, sarcopenia predicted inferior patient and graft survival, with low muscle density (PD: <38.5 HU or SMD: <30 HU) representing an independent risk factor in a multivariate regression model (P < 0.05). Importantly, the widely used Eurotransplant donor risk index had a predictive value in nonsarcopenic patients but failed to predict graft survival in patients with sarcopenia.

CONCLUSIONS

Sarcopenia revealed by low muscle density correlates with major complications following LT and acts as an independent predictor for patient and graft survival. Therefore, the application of a simple computerized tomography-morphologic index can refine an individual recipient's risk estimate in a personalized approach to transplantation.

Sarcopenia as prognostic factor for survival after orthotopic liver transplantation

BACKGROUND AND AIM

Body composition has emerged as a prognostic factor for end-stage liver disease. We therefore investigated muscle mass, body fat and other clinical-pathological variables as predictors of posttransplant survival.

METHODS

A total of 368 patients, who underwent orthotopic liver transplantation (OLT) at our institution, were assessed prior to OLT and followed for a median of 9.0 years (range 2.0-10.0 years) after OLT. Psoas, erector spinae and the combined paraspinal muscle area, as well as the corresponding indices normalized by body-height squared, were quantified by a lumbar (L3) cross-sectional computed tomography. In addition, absolute body fat and bone density were estimated by the same computed tomography approach.

RESULTS

Paraspinal muscle index (PSMI) (hazard ratio 0.955, P = 0.039) and hepatitis C (hazard rati 1.498, P = 0.038) were independently associated with post-OLT mortality. In contrast, body fat and bone density did not significantly affect post-OLT outcome (P > 0.05). The PSMI also predicted one-year posttransplant mortality with a receiver operating characteristics-area under the curve of 0.671 [95% confidence interval (CI) 0.589-0.753, P < 0.001) in male patients and outperformed individual psoas and erector spinae muscle group assessments in this regard. In male patients, a defined PSMI cutoff (<18.41 cm/m) was identified as suitable determinant for sarcopenia and posttransplant one-year mortality. In female OLT-recipients, however, sarcopenia was not predictive for patient survival und a women-specific cutoff could not be derived from this study.

CONCLUSIONS

Taken together this analysis provides evidence, which PSMI is a relevant marker for muscle mass and that sarcopenia is an independent predictor of early post-OLT survival in male patients.

Opportunistic Measurement of Skeletal Muscle Size and Muscle Attenuation on Computed Tomography Predicts 1-Year Mortality in Medicare Patients

BACKGROUND

Opportunistic assessment of sarcopenia on CT examinations is becoming increasingly common. This study aimed to determine relationships between CT-measured skeletal muscle size and attenuation with 1-year risk of mortality in older adults enrolled in a Medicare Shared Savings Program (MSSP).

METHODS

Relationships between skeletal muscle metrics and all-cause mortality were determined in 436 participants (52% women, mean age 75 years) who had abdominopelvic CT examinations. On CT images, skeletal muscles were segmented at the level of L3 using two methods: (a) all muscles with a threshold of -29 to +150 Hounsfield units (HU), using a dedicated segmentation software, (b) left psoas muscle using a free-hand region of interest tool on a clinical workstation. Muscle cross-sectional area (CSA) and muscle attenuation were measured. Cox regression models were fit to determine the associations between muscle metrics and mortality, adjusting for age, sex, race, smoking status, cancer diagnosis, and Charlson comorbidity index.

RESULTS

Within 1 year of follow-up, 20.6% (90/436) participants died. In the fully-adjusted model, higher muscle index and muscle attenuation were associated with lower risk of mortality. A one-unit standard deviation (SD) increase was associated with a HR = 0.69 (95% CI = 0.49, 0.96; p = .03) for total muscle index, HR = 0.67 (95% CI = 0.49, 0.90; p < .01) for psoas muscle index, HR = 0.54 (95% CI = 0.40, 0.74; p < .01) for total muscle attenuation, and HR = 0.79 (95% CI = 0.66, 0.95; p = .01) for psoas muscle attenuation.

CONCLUSION

In older adults, higher skeletal muscle index and muscle attenuation on abdominopelvic CT examinations were associated with better survival, after adjusting for multiple risk factors.

Paediatric reference values for total psoas muscle area

BACKGROUND

Sarcopenia, the unintentional loss of skeletal muscle mass, is associated with poor outcomes in adult patient populations. In adults, sarcopenia is often ascertained by cross-sectional imaging of the psoas muscle area (PMA). Although children with chronic medical illnesses may be at increased risk for muscle loss because of nutritional deficiencies, physical deconditioning, endocrine anomalies, and systemic inflammation, consistent quantitative definitions for sarcopenia in children are lacking. We aimed to generate paediatric reference values for PMA at two intervertebral lumbar levels, L3-4 and L4-5.

METHODS

In this cross-sectional study, we analysed abdominal computed tomography scans of consecutive children presenting to the emergency department. Participants were children 1-16 years who required abdominal cross-sectional imaging after paediatric trauma between January 1, 2005 and December 31, 2015 in a large Canadian quaternary care centre. Children with a documented chronic medical illness or an acute spinal trauma at presentation were excluded. Total PMA (tPMA) at levels L3-4 and L4-5 were measured in square millimetres (mm² ) as the sum of left and right PMA. Age-specific and sex-specific tPMA percentile curves were modelled using quantile regression.

RESULTS

Computed tomography images from 779 children were included. Values of tPMA at L4-5 were significantly larger than at L3-4 at all ages, but their correlation was high for both girls (r = 0.95) and boys (r = 0.98). Amongst girls, tPMA 50th percentile values ranged from 365 to 2336 mm² at L3-4 and from 447 to 2704 mm² for L4-5. Amongst boys, 50th percentile values for tPMA ranged between 394 and 3050 mm² at L3-4 and from 498 to 3513 mm² at L4-5. Intraclass correlation coefficients were excellent at L3-4 (0.97, 95% CI 0.94 to 0.981) and L4-5 (0.99, 95% CI 0.986 to 0.995). Weight and tPMA were correlated, stratified by sex for boys (L3-4 r = 0.90; L4-5 r = 0.90) and for girls (L3-4 r = 0.87; L4-5 r = 0.87). An online application was subsequently developed to easily calculate age-specific and sex-specific z-scores and percentiles.

CONCLUSIONS

We provide novel paediatric age-specific and sex-specific growth curves for tPMA at intervertebral L3-4 and L4-5 levels for children between the ages of 1-16 years. Together with an online tool (https://ahrc-apps.shinyapps.io/sarcopenia/), these tPMA curves should serve as a reference enabling earlier identification and targeted intervention of sarcopenia in children with chronic medical conditions.

Influence of Preoperative Muscle Mass Assessed by Computed Tomography on Prognosis After Liver Transplantation

BACKGROUND

Sarcopenia (SP) and preoperative muscle mass are independent predictive factors for short- and long-term outcome of liver transplantation.

OBJECTIVE

To assess the influence of muscle mass index (MMI) and preoperative SP on the prognosis of patients who underwent liver transplantation in our hospital.

METHODS

Ninety-seven patients who underwent liver transplantation in the Regional University Hospital of Málaga from September 2013 to March 2016 were analyzed. SP was determined based on the MMI, as assessed by psoas muscle area at the L4 level measured by computed tomography (CT), with adjustment for patient sex. Two cohorts were differentiated: 54 patients without SP and 42 patients with SP. Postoperative complications, graft survival, and patient survival were assessed. A 3-year follow-up was carried out.

RESULTS

Recipient characteristics were similar in both cohorts, except for MMI ± SD (group without SP: 94.03 ± 15.43 cm2/m2 vs group with SP: 56.99 ± 13.59 cm2/m2; P = .001). The incidence of postoperative complications (Clavien ≥ 3) in patients with and without SP was 39.5% and 24.1%, respectively (P = .08). SP was not associated with poorer long-term graft or patient survival.

CONCLUSIONS

SP, determined by preoperative measurement of MMI, was identified as a predictive factor associated with a higher incidence of postoperative complications. Since MMI can be easily determined by CT, it should be assessed in all candidates for liver transplantation.

Visceral Adipose Tissue Radiodensity Is Linked to Prognosis in Hepatocellular Carcinoma Patients Treated with Selective Internal Radiation Therapy

Hepatocellular carcinoma (HCC) constitutes the fourth leading cause of cancer-related mortality. Various factors, such as tumor size, tumor multiplicity, and liver function, have been linked to the prognosis of HCC. The aim of this study was to explore the prognostic significance of muscle, subcutaneous and visceral adipose tissue (VAT) mass, and radiodensity, in a cohort of 101 HCC patients treated with selective internal radiation therapy (SIRT). Muscle and adipose tissue cross sectional area (cm²/m²) and radiodensity, reported as the Hounsfield Unit (HU), were determined using pre-SIRT computed tomography images. Cox proportional hazard models and exact logistic regression were conducted to assess associations between body composition and adverse outcomes. Majority of the patients were male (88%) with a mean VAT radiodensity of −85 ± 9 HU. VAT radiodensity was independently associated with mortality (HR 1.05; 95% CI: 1.01–1.08; p = 0.01), after adjusting for cirrhosis etiology, Barcelona Clinic Liver Cancer stage, previous HCC treatment, and portal hypertension markers. Patients with a high VAT radiodensity of ≥–85 HU had a two times higher risk of mortality (HR 2.01, 95% CI 1.14–3.54, p = 0.02), compared to their counterpart. Clinical features of portal hypertension were more prevalent in patients with high VAT radiodensity. High VAT radiodensity was associated with severe adverse events after adjusting for confounding factors. High VAT radiodensity is independently associated with both increased mortality and severe adverse events in patients treated with SIRT. VAT radiodensity measurement might serve as an objective approach to identify patients who will experience the most benefit from SIRT.

Agreement between software programmes of body composition analyses on abdominal computed tomography scans of obese adults

Objective A large number of studies have used abdominal computed tomography (CT) to quantify body composition, and different software programmes have been used to perform these analyses. Thus, this comparison is important to enable researchers to know the performance of more accessible software. Subjects and methods Fifty-four abdominal CT scans of obese (BMI 30 to 39.9 kg/m2), sedentary adults (24-41 years) patients from a Brazilian single center were selected. Two software programs were compared: Slice-O-Matic (Tomovision, Canada) version 5.0 and OsiriX version 5.8.5. The body composition analysis were segmented using standard Hounsfield unit (HU) (adipose tissue: -190 to +30 and skeletal muscle: -29 to +150) and measured at the mid third lumbar vertebra (L3) level on a slice showing both transversal processes. Bland-Altman limits of agreement analyses were used to assess the level of agreement between Slice-O-Matic and OsiriX. Results A total of fifty-four participants were evaluated, with majority women (69%), mean of age 31.3 (SD 6.5) years and obesity grade I most prevalent (74.1%). The agreement, in Bland-Altman analysis, between Slice-O-Matic and OsiriX analisys for the muscle mass tissue, visceral adipose tissue and subcutaneous adipose tissue were excellent (≥ 0.954) with P-values < 0.001. Conclusion These findings show that Slice-O-Matic and OsiriX softwares agreement in measurements of skeletal muscle and adipose tissue and sarcopenia diagnosis in obese patients, suggesting good applicability in studies with body composition in this population and clinical practice.

Automated body composition analysis of clinically acquired computed tomography scans using neural networks

BACKGROUND & AIMS

The quantity and quality of skeletal muscle and adipose tissue is an important prognostic factor for clinical outcomes across several illnesses. Clinically acquired computed tomography (CT) scans are commonly used for quantification of body composition, but manual analysis is laborious and costly. The primary aim of this study was to develop an automated body composition analysis framework using CT scans.

METHODS

CT scans of the 3rd lumbar vertebrae from critically ill, liver cirrhosis, pancreatic cancer, and clear cell renal cell carcinoma patients, as well as renal and liver donors, were manually analyzed for body composition. Ninety percent of scans were used for developing and validating a neural network for the automated segmentation of skeletal muscle and adipose tissues. Network accuracy was evaluated with the remaining 10 percent of scans using the Dice similarity coefficient (DSC), which quantifies the overlap (0 = no overlap, 1 = perfect overlap) between human and automated segmentations.

RESULTS

Of the 893 patients, 44% were female, with a mean (±SD) age and body mass index of 52.7 (±15.8) years old and 28.0 (±6.1) kg/m², respectively. In the testing cohort (n = 89), DSC scores indicated excellent agreement between human and network-predicted segmentations for skeletal muscle (0.983 ± 0.013), and intermuscular (0.900 ± 0.034), visceral (0.979 ± 0.019), and subcutaneous (0.986 ± 0.016) adipose tissue. Network segmentation took ~350 milliseconds/scan using modern computing hardware.

CONCLUSIONS

Our network displayed excellent ability to analyze diverse body composition phenotypes and clinical cohorts, which will create feasible opportunities to advance our capacity to predict health outcomes in clinical populations.

Assessment of magnetic resonance imaging derived fat fraction as a sensitive and reliable predictor of myosteatosis in liver transplant recipients

BACKGROUND

Measures of skeletal muscle abnormalities are rapidly emerging as independent predictors of outcomes after liver transplantation (LT). We describe a simple, novel assessment of myosteatosis acquired prior to liver transplantation using Magnetic Resonance Imaging (MRI) derived fat fraction.

METHODS

A retrospective longitudinal cohort study included clinical and biochemical data from patients who underwent liver transplantation at our institution between Feb 2008 and Aug 2014. Patients transplanted for a diagnosis of hepatocellular carcinoma were excluded from the study. The fat fraction of erector spinae muscles was estimated using MRI at the level where muscle volume was highest, with myosteatosis defined at a cut-off value of 0.8.

RESULTS

180 patients were included. At baseline, those with myosteatosis were, on average, older, more likely to be female, and more likely to receive a multi-organ transplant (p < 0.05). Patients with pre-transplant myosteatosis, as delineated by MRI derived fat fraction, also had increased length of hospital stay.

CONCLUSION

This preliminary study suggests myosteatosis, as measured by fat fraction on MRI prior to LT, may be associated with increased graft loss and mortality after transplant.

Association of Chest CT-Based Quantitative Measures of Muscle and Fat with Post-Lung Transplant Survival and Morbidity: A Single Institutional Retrospective Cohort Study in Korean Population

OBJECTIVE

Abnormal body composition is an important modifiable risk factor in lung transplantation. Therefore, precise quantification of different body components, including muscle and fat, may play an important role in optimizing outcomes in lung transplant patients. The purpose of the study was to investigate the prognostic significance of muscle and subcutaneous fat mass measured on chest CT with regard to lung transplantation survival and other post-transplant outcomes.

MATERIALS AND METHODS

The study population included 45 consecutive adult lung transplant recipients (mean age of 47.9 ± 12.1 years; 31 males and 14 females) between 2011 and 2017. Preoperative cross-sectional areas of muscle and subcutaneous fat were semi-automatically measured on axial CT images at the level of the 12th thoracic vertebra (T12). Additional normalized indexed parameters, adjusted for either height or weight, were obtained. Associations of quantitative parameters with survival and various other post-transplant outcomes were evaluated.

RESULTS

Of the 45 patients included in the present study, 10 mortalities were observed during the follow-up period. Patients with relative sarcopenia (RS) classified based on height-adjusted muscle area with a cut-off value of 28.07 cm²/m² demonstrated worse postoperative survival (log-rank test, p = 0.007; hazard ratio [HR], 6.39:1) despite being adjusted for age, sex, and body mass index (HR, 8.58:1; p = 0.022). Weight-adjusted parameters of muscle area were negatively correlated with duration of ventilator support (R = -0.54, p < 0.001) and intensive care unit (ICU) stay (R = -0.33, p = 0.021).

CONCLUSION

Patients with RS demonstrate worse survival after lung transplantation that those without RS. Additionally, quantitative parameters of muscles measured at the T12 level on chest CT were associated with the duration of post-lung transplant ventilator support and duration of stay in the ICU.

Validation of cutoffs for skeletal muscle mass index based on computed tomography analysis against dual energy X-ray absorptiometry in patients with cirrhosis: the KIRRHOS study

Background:

Accurate assessments of muscle mass in patients with cirrhosis are necessary in clinical practice. Computed tomography (CT) of the upper abdomen has been proposed as a useful method for quantifying muscle mass. Recently, Carey et al developed specific cutoffs for muscle wasting based on the skeletal muscle index at the L3 vertebra (L3-SMI) for cirrhotic patients. The aim of the present study was to assess the concurrent validity of the newly proposed cutoffs of Carey et al, along with others widely used in several clinical contexts, using dual energy X-ray absorptiometry (DXA) as the reference method.

Methods:

Data were evaluated from 97 Caucasian patients (59.8% male, 59.1±11.6 years old, 45.4% decompensated) with cirrhosis of various etiologies. Muscle mass was assessed using the appendicular lean mass index (ALMI) by DXA and the L3-SMI by CT. Low L3-SMI was defined in relation to 5 different cutoffs.

Results:

Low muscle mass prevalence was 13.4% according to ALMI and 26.8-45.4% according to the different cutoffs applied for L3-SMI. The Carey et al, Prado et al and Montano-Loza et al cutoffs showed similar sensitivity (all 69.2%) and specificity (79.8%, 76.2% and 75.0%, respectively) and high accuracy (78.4%, 75.3% and 74.2%). The Carey et al cutoffs showed the highest diagnostic validity against DXA the multivariate odds ratio adjusted for age, sex, body mass index category, disease etiology and model for end-stage liver disease score (95% confidence interval) was 5.88 (1.36-25.4), P=0.018.

Conclusion:

Compared to DXA, the cutoffs for identifying muscle wasting proposed by Carey et al were proven to be the most accurate.

Clinical relevance of skeletal muscle abnormalities in patients with cirrhosis

Recent advances in body composition evaluation have demonstrated abnormalities in skeletal muscle in patients with cirrhosis. Sarcopenia (severe muscle depletion) and myosteatosis (pathological fat accumulation in muscle) are prevalent muscle abnormalities in patients with cirrhosis that confer poor prognosis. Sarcopenia has become a well-defined factor for adverse clinical outcomes pre- and post-liver transplantation and emerging evidence has suggested the prognostic significance of myosteatosis in predicting mortality and overt hepatic encephalopathy in patients with cirrhosis. Advances in the understating of these muscle abnormalities might help improve therapeutic interventions to correct them and potentially improve outcomes of patients with cirrhosis. Moreover, inclusion of these muscle abnormalities within the current organ allocation policies might lead to a better mortality risk assessment in patients awaiting liver transplant and even to a decrease in the rates of futile liver transplants. This review summarizes the current knowledge regarding the modalities to evaluate skeletal muscle abnormalities in cirrhosis, the incidence and clinical impact of these abnormalities in cirrhosis; existing and potential novel therapeutic strategies are also discussed.

Frailty, Sarcopenia, and Malnutrition in Cirrhotic Patients

Sarcopenia, frailty, and malnutrition are prevalent complications in patients with end-stage liver disease (ESLD) and are associated with increased risk of morbidity and mortality. It is valuable to measure nutritional status, sarcopenia, and frailty over time in order to create interventions tailored to individuals with ESLD. Evaluating sarcopenia and frailty in patients with ESLD is challenging. Further work is needed to perfect these assessments so that clinicians can incorporate these assessments into their decision-making and management plans for cirrhotic patients.

Pretransplant Sarcopenia in Patients With NASH Cirrhosis Does Not Impact Rehospitalization or Mortality

BACKGROUND

Malnutrition and muscle wasting are common in patients with end-stage liver disease (ESLD), yet go underdiagnosed. Frequently used indices of nutritional status, such as body mass index, are inflated in patients with ESLD due to a fluid overloaded state. Previous work has demonstrated a strong association between psoas muscle area, a surrogate for sarcopenia, and worse survival following liver transplantation; however, the impact of sarcopenia on post liver transplant outcomes in patients with nonalcoholic steatohepatitis (NASH) cirrhosis has not been evaluated.

GOALS

Describe the impact of sarcopenia in patients with NASH cirrhosis on post liver transplantation outcomes, including initial hospital length of stay, rehospitalization, and survival.

MATERIALS AND METHODS

A single-center, retrospective analysis was conducted of adult liver transplants performed for NASH cirrhosis between 2002 and 2015. Sarcopenia was defined by psoas area measured at the L3 vertebra from abdominal imaging within 6 months before orthotopic liver transplant (OLT).

RESULTS

A total of 146 patients were evaluated. The mean Model for End-Stage Liver Disease score at transplant was 34.9±7.4. Sarcopenia was present in 62% of patients and was more likely in female and Hispanic patients. There were no significant differences in length of initial hospitalization following OLT, days hospitalized within the first year post-OLT, survival at 1 year, or overall survival between sarcopenic and nonsarcopenic patients.

CONCLUSIONS

Sarcopenia in patients with NASH cirrhosis and high Model for End-Stage Liver Disease scores is not associated with an increase in mortality or rehospitalization following liver transplantation; however, the study findings were limited by a small sample size.

Psoas Muscle Density in Combination with Model for End-Stage Liver Disease Score Can Improve Survival Predictability in Transjugular Intrahepatic Portosystemic Shunts

PURPOSE

To examine the role of psoas muscle density (PD) measurement before transjugular intrahepatic portosystemic shunt (TIPS) creation in predicting survival when combined with Model for End-stage Liver Disease (MELD) score.

MATERIALS AND METHODS

The medical records of 241 patients with cirrhosis who underwent TIPS creation between June 2005 and June 2015 were retrospectively reviewed. The patients were divided into 2 groups: those with variceal bleeding (VB; n = 113) and those with volume overload (VO; n = 128). The study included 149 men (62%), and mean patient age was 56 years ± 9.6 (range 24-83). Mean MELD score before TIPS creation was 11.8 ± 5.7. A threshold sensitivity of pre-TIPS PD for the assessment of mortality was calculated and then correlated with survival after TIPS creation. Receiver operating characteristic curves comparing 12-month mortality were used to assess the improvement in survival predictability after TIPS creation when the PD threshold was combined with MELD score vs MELD score alone.

RESULTS

Mean post-TIPS follow-up was 29.9 month ± 34.1 (range 1-3700 days). There was no significant difference in 3- or 12-month mortality rates between the VB and VO groups (32.7% vs 25.8% [P = .23] and 46% vs 46.1% [P = .99], respectively). The MELD score threshold for prediction of survival was 15 (P < .0001). There was no difference in the mean PD between VB and VO groups (34.2 HU ± 8.8 and 33.1 HU ± 10.3, respectively; P = .359). The increase in MELD score after TIPS creation was significant in both groups (VB, P = .0013; VO, P < .0001). The threshold of pre-TIPS PD for discrimination of survival was 29.4 HU (P < .0001), and PD measurements greater than this threshold were associated with a lower risk of mortality (hazard ratio, 0.27; 95% confidence interval, 0.13-0.57; P = .0006). Compared with the use of MELD score alone, the addition of PD measurement significantly increased the area under the curve from 0.61 to 0.68 (P = .0006).

CONCLUSIONS

Measurement of PD improved overall survival predictability in patients with cirrhosis undergoing TIPS creation when used in conjunction with MELD score. The best survival outcome was observed in patients with MELD score < 15 in combination with PD > 29.4 HU.

Multi-compartment mesenchymal tissue segmentation in pelvic MRI examinations of women: Anthropomorphic and clinical correlations

AIM

To investigate the reliability of multicompartmental volumetric mesenchymal segmentations on MRI and their correlations with anthropomorphic and clinical parameters.

MATERIALS AND METHODS

A consecutive series of middle-age (35-50 year old) female volunteers with variable body mass index (BMI) and MRI scans performed as a part of the Dallas Heart Study were included. A semi-automatic segmentation tool was used to partition different mesenchymal tissues- fat, muscle, and bone on MRI of pelvis. Total volumes of each compartment were calculated and compared between overweight/obese (BMI> = 25 kg/m2) and non-obese (BMI < 25 kg/m2) groups, and with physical performance measurements, i.e. mean activity counts per minute (MVPA) and cardiorespiratory fitness (CRF) estimated by submaximal treadmill test (TT). Kruskal Wallis, Mann-Whitney U test, intraclass correlation coefficient (ICC) and Spearman correlations were used. P value <0.05 was considered statistically significant.

RESULTS

There were statistically significant positive correlations between fat volume and BMI (p < 0.0001), muscle volume and height (p = 0.03), and bone volume and height (p < 0.0001). Significant inverse correlations were found between bone volume and BMI (p = 0.002). Fair to good interobserver reliability was seen with muscle and fat volumes (ICC = 0.43-0.64) and excellent reliability was seen with bone volumes (ICC = 0.78-0.79). Statistically significant inverse correlations were found between MVPA and age (p = 0.01), and TT with BMI and weight (p = 0.01, 0.03).

CONCLUSION

Multi-compartment mesenchymal tissue volume quantification on pelvic MRI is reliable in females. Inverse correlation of bone volume with BMI has potential implications for future risk of fracture.

Sarcopenia in Liver Transplantation

PURPOSE OF REVIEW

Sarcopenia is highly prevalent in end-stage liver disease (ESLD) patients and has been linked to poor outcomes on the wait list and post-transplantation. This current perspectives article reviews the ongoing challenges to define sarcopenia in ESLD patients, describes associations of sarcopenia with wait-list and post-transplantation outcomes, and provides summarized data on efforts to prevent and treat sarcopenia through novel interventions.

RECENT FINDINGS

Supervised exercise programs improve muscle strength, but muscle mass outcomes are limited by short study follow-up times. Branched chain amino acid supplementation may ameliorate sarcopenia in ESLD patients, but studies limited by low participant numbers and confounding. Myostatin inhibition shown to improve sarcopenia in elderly, frail patients; further study needed in ESLD patients. Correction of low testosterone improves sarcopenia in male ESLD patients.

SUMMARY

Recent literature supports sarcopenia as an independent risk factor for poor outcomes in ESLD patients. Ongoing study is limited by poor standardization of sarcopenia definition and relevant muscle-mass cutoffs. Supervised exercise programs should be encouraged for all ESLD patients. More advanced therapies require further clinical investigation before their widespread use.

Relationship Between Total Body Protein and Cross-Sectional Skeletal Muscle Area in Liver Cirrhosis Is Influenced by Overhydration

Sarcopenia as defined by reduced skeletal muscle area (SMA) on cross-sectional abdominal imaging has been proposed as an objective measure of malnutrition, and it is associated with both wait-list mortality and posttransplant complications in patients with cirrhosis. SMA, however, has never been validated against the gold standard measurement of total body protein (TBP) by in vivo neutron activation analysis (IVNAA). Furthermore, overhydration is common in cirrhosis, and its effect on muscle area measurement remains unknown. We aimed to examine the relationship between SMA and TBP in patients with cirrhosis and to assess the impact of overhydration on this relationship. Patients with cirrhosis who had undergone IVNAA and cross-sectional imaging within 30 days were retrospectively identified. Patients with significant clinical events between measurements were excluded. Psoas muscle area (PMA) and SMA at the level of the third lumbar vertebrae were determined. Total body water was estimated from a multicompartment model and expressed as a fraction of fat-free mass (FFM), as determined by dual-energy X-ray absorptiometry, to provide an index of hydration status. In total, 107 patients underwent 109 cross-sectional imaging studies (87 computed tomography; 22 magnetic resonance imaging) within 30 days of IVNAA. Median time between measurements was 1 day (IQR, -1 to 3 days). Between 43% and 69% of the cohort was identified as sarcopenic, depending on muscle area cutoff values used. TBP was strongly correlated with SMA (r = 0.78; P < 0.001) and weakly correlated with PMA (r = 0.49; P < 0.001). Multiple linear regression showed SMA was significantly and positively associated with FFM hydration (P < 0.001) independently of TBP. In conclusion, SMA is more closely related to TBP than is PMA, and it should be preferred as a measure of sarcopenia. Overhydration significantly affects the measurement of cross-sectional muscle area.

Sarcopenia and chronic liver diseases

INTRODUCTION

Sarcopenia is a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength, which is commonly associated with various chronic diseases, including chronic liver diseases. Growing lines of evidence indicate that sarcopenia not only correlates with the clinical outcomes and survival of patients undergoing liver transplant, but also serves as a prognostic factor for candidates of liver transplantation and patients with hepatocellular carcinoma. Areas covered: In this review, we conducted a narrative review and search of literature from PubMed, Ovid MEDLINE, and the Cochrane Library database up to August 2018. Studies relevant to the emerging data of sarcopenia and chronic liver diseases were examined and discussed. Expert commentary: Although sarcopenia has been shown to play a vital role in the outcomes of cirrhotic patients with or without liver transplant, its impact on non-cirrhotic patients remains unclear and deserves future research efforts. To develop an effective and practical measurement of sarcopenia has become an urgent issue in the management of patients with chronic liver diseases.

ABBREVIATIONS

HCC: hepatocellular carcinoma; L3SMI: third lumbar vertebra skeletal muscle index; NAFLD: nonalcoholic fatty liver disease; VAT: visceral adipose tissue; PMA: psoas muscle area; LT: liver transplantation; AUC: area under the curve; LC: liver cirrhosis; SPPB: short physical performance battery; HU: Hounsfield units; ASM: appendicular skeletal muscle; SMI: skeletal muscle index; FLI: fatty liver index; PCLD: polycystic liver disease; DEXA: dual energy X-ray absorptiometry; BCAAs: branched-chain amino acids; BIA: bioelectrical impedance analysis; CT: computed tomography; OS: overall survival; CSA: cross-sectional area; NASH: nonalcoholic steatohepatitis; TPMT: transversal psoas muscle thickness; IMAC: intramuscular adipose tissue content; LDLT: living donor liver transplantation; PMI: psoas muscle mass index; PMTH: psoas muscle thickness by height; TPA: total psoas area; OLT: orthotopic liver transplantation; 6MWD: Six-minute walk distance; HRQOL: health-related quality of life; SMA: skeletal muscle area.

Exercise in cirrhosis: Translating evidence and experience to practice

Physical inactivity, sarcopenia, and frailty are highly prevalent, independent predictors of morbidity and mortality in patients with cirrhosis. Across a range of chronic diseases, exercise training is a key recommendation supported by guidelines and, for some conditions, even by governmental funding of exercise programmes. Consistent with the broader chronic disease literature, the evidence for a benefit of exercise in cirrhosis is promising. Several small trials have reported significant improvements in muscle health (mass, strength, functional capacity), quality of life, fatigue, and reductions in the hepatic venous pressure gradient, without adverse events. With strong emerging evidence surrounding the substantial risks of sarcopenia/frailty and our first-hand experiences with liver pre-transplant exercise programmes, we contend that routine patient care in cirrhosis should include an exercise prescription. Some clinicians may lack the resources and necessary background to translate the existing evidence into a practicable intervention. Our team, comprised of physiotherapists, exercise physiologists, hepatologists, transplant specialists, and knowledge translation experts from six North American centres, has distilled the essential background information, tools, and practices into a set of information ready for immediate implementation into clinics ranging from a family practice setting to specialty cirrhosis clinics. Augmenting the rationale and evidence are supplementary materials including video and downloadable materials for both patients and the physician. Supporting the exercising patient is a section regarding information about nutrition, providing practical tips suitable for all patients with cirrhosis.

Fat-free muscle mass in magnetic resonance imaging predicts acute-on-chronic liver failure and survival in decompensated cirrhosis

Muscle mass seems to be a prognostic marker in patients with liver cirrhosis. However, reported methods to quantify muscle mass are heterogeneous, consented cutoff values are missing, and most studies have used computed tomography. This study evaluated fat-free muscle area (FFMA) as a marker of sarcopenia using magnetic resonance imaging (MRI) in patients with decompensated cirrhosis with transjugular intrahepatic portosystemic shunt (TIPS). The total erector spinae muscle area and the intramuscular fat tissue area were measured and subtracted to calculate the FFMA in 116 patients with cirrhosis by TIPS and MRI. The training cohort of 71 patients compared computed tomography-measured transversal psoas muscle thickness with FFMA. In 15 patients MRI was performed before and after TIPS, and in 12 patients follistatin serum measurements were carried out. The results on FFMA were confirmed in a validation cohort of 45 patients. FFMA correlated with follistatin and transversal psoas muscle thickness and showed slightly better association with survival than transversal psoas muscle thickness. Gender-specific cutoff values for FFMA were determined for sarcopenia. Decompensation (ascites, overt hepatic encephalopathy) persisted after TIPS in the sarcopenia group but resolved in the nonsarcopenia group. Sarcopenic patients showed no clinical improvement after TIPS as well as higher mortality, mainly due to development of acute-on-chronic liver failure. FFMA was an independent predictor of survival in these patients.

CONCLUSION

This study offers an easy-to-apply MRI-based measurement of fat-free muscle mass as a marker of sarcopenia in decompensated patients; while TIPS might improve sarcopenia and thereby survival, persistence of sarcopenia after TIPS is associated with a reduced response to TIPS and a higher risk of acute-on-chronic liver failure development and mortality. (Hepatology 2018;67:1014-1026).

Sarcopenia in Children With End-Stage Liver Disease

BACKGROUND

Sarcopenia, reflected by decreased psoas muscle surface area (PMSA), has been identified as a novel and independent predictor of wait-list mortality and outcomes in adult liver transplantation (LT). We hypothesized that children with end-stage liver disease (ESLD) would have smaller PMSA than healthy controls.

METHODS

Computer tomography images of children (ages 0 to 18 years) listed for LT in 2015 and a control group comprised 2:1 age- and gender-matched healthy pediatric trauma victims were reviewed. PMSA was determined at 2 intervertebral disc (L3/4; L4/5) levels. A subset of images was reviewed by 2 radiologists to determine interrater correlation.

RESULTS

A total of 23 children with ESLD were included, and the most prevalent diagnosis was biliary atresia (61%). On both lumbar levels, median PMSA was significantly smaller in ESLD subjects compared with the 46 healthy controls (L4/5; median total PMSA (tPMSA) 407 mm (interquartile range 339-537) versus controls 513 mm (interquartile range 437-672); P = 0.004), independent of participants' weight z scores (r = 0.01; P = 0.95). Excellent interrater correlation was seen (intraclass correlation 0.99).

CONCLUSIONS

In this retrospective pilot study, PMSA was significantly lower in children with ESLD compared with healthy age- and gender-matched controls. Because this finding was independent of growth in ESLD subjects, PMSA may represent a novel objective nutritional biomarker in children with advanced liver disease.

Exercise and physical activity for patients with end-stage liver disease: Improving functional status and sarcopenia while on the transplant waiting list

Sarcopenia and physical deconditioning are frequent complications in patients with cirrhosis and end-stage liver disease (ESLD). They are the end result of impaired dietary intake, chronic inflammation, altered macronutrient and micronutrient metabolism, and low physical activity. Frailty is the end result of prolonged sarcopenia and physical deconditioning. It severely affects a patient's functional status and presents in approximately 1 in 5 patients on the liver transplantation waiting list. Sarcopenia, poor physical fitness/cardiopulmonary endurance (CPE), and frailty are all associated with increased mortality in ESLD. Clinical trials addressing the usefulness of exercise in patients with cirrhosis have shown that it improves the metabolic syndrome, sarcopenia, CPE, health-related quality of life, and hepatic venous pressure gradient. Although evidence on the benefits of exercise on clinical outcomes derived from large clinical trials is still missing, based on existing literature from multiple medical subspecialties, we believe that an exercise program coupled to a tailored nutritional intervention benefits both cardiopulmonary and musculoskeletal functions, ultimately translating into improved functional status, sense of well-being, and possibly less complications from portal hypertension. In conclusion, although supervised exercise training is the prevailing approach to manage ESLD patients, such intervention is not sustainable or feasible for most patients. Innovative home-based physical activity interventions may be able to effectively reach a larger number of patients. Liver Transplantation 24 122-139 2018 AASLD.

Nutrition and the transplant candidate

Cirrhosis is the most common indication for liver transplantation (LT) worldwide. Malnutrition is present in at least two-thirds of patients with cirrhosis awaiting LT. It negatively impacts survival, quality of life, and the ability to respond to stressors, such as infection and surgery. Muscle wasting or sarcopenia is the most objective feature of chronic protein malnutrition in cirrhosis, and this condition is associated with increased morbidity and mortality before and after LT. In addition to its objectivity, muscularity assessment with cross-sectional imaging studies is a useful marker of nutritional status in LT candidates, as sarcopenia reflects a chronic decline in the general physical condition, rather than acute severity of the liver disease. Despite the high prevalence and important prognostic role, malnutrition and sarcopenia are frequently overlooked because standards for nutritional assessment are lacking and challenges such as fluid retention and obesity are prevalent. In this review, current diagnostic methods to evaluate malnutrition, including muscle abnormalities in cirrhosis, are discussed and current knowledge regarding the incidence and clinical impact of malnutrition in cirrhosis and its impact after LT are presented. Existing and potential novel therapeutic strategies for malnutrition in cirrhosis are also discussed, emphasizing the treatment of muscle wasting in the LT candidate in an effort to improve survival while waiting for LT and to reduce morbidity and mortality after LT.Liver Transplantation 23 1451-1464 2017 AASLD.