Power of computed-tomography-defined sarcopenia for prediction of morbidity after pancreaticoduodenectomy

Effects of nutritional status on short-term prognosis after minimally invasive pancreaticoduodenectom

Minimally invasive pancreaticoduodenectomy (MIPD) has been routinely performed in major centers, and its feasibility and efficacy in tumor treatment have been highly recognized. Malnutrition has been associated with higher rates of morbidity, and increased mortality in surgical patients. The effect of the nutritional status on MIPD outcomes still remains unclear and controversial. The clinical data of 207 consecutive patients who had MIPD between June 2017 and December 2022 were retrospectively analyzed. A multidimensional nutrition assessment was performed before surgery. Multivariable analysis and propensity score matching (PSM) was performed to identify the association of preoperative nutritional status on postoperative short-term prognosis(Morbidity-Mortality, Clavien-Dindo classification ≥ IIIa, postoperative pancreatic fistulas and biliary fistula). In the multivariable analysis, sarcopenia (OR 9.74, 95% CI 3.34-43.03) was associated with postoperative morbidity and sarcopenia (OR 6.74, 95% CI 2.24-30.24) was associated with major complications. In the cohort after PSM, sarcopenia remained independently associated with morbidity (OR 12.44, 95% CI 3.72- 59.16) and major complications (OR 8.14, 95% CI 2.13- 43.83). Sarcopenia before MIPD has an impact on postoperative outcomes. Nutritional status assessment, especially sarcopenia, should be part of the routine preoperative procedures to provide early and appropriate nutritional support for MIPD patients.

The Association Between Preoperative Sarcopenia and Sarcopenic Obesity and the Occurrence of Postoperative Complications in Patients Undergoing Pancreaticoduodenectomy for Periampullary Malignancies-A Literature Review

BACKGROUND

Sarcopenia and sarcopenic obesity, perceived as a reflection of cancer-induced cachexia, are often diagnosed in patients with periampullary malignancies. The pathophysiology of those conditions is multifactorial regarding the tumor microenvironment, immunological response, and the relationship to surrounding tissues.

METHODS

The PubMed and SCOPUS databases were systematically searched between November 2023 and December 2023. A total of 254 studies were primarily identified. Regarding the inclusion and exclusion criteria, 26 studies were finally included in the review.

RESULTS

Evaluated papers disclosed that sarcopenia was significantly associated with a higher incidence of postoperative complications, including pancreatic fistula (POPF) type B and C, with the odds ratio (OR) ranging from 2.65 (95%CI 1.43-4.93, p = 0.002) to 4.30 (95%CI 1.15-16.01, p < 0.03). Sarcopenic patients also suffered more often from delayed gastric emptying (DGE) with an OR of 6.04 (95%CI 1.13-32.32, p = 0.036). Infectious complications, postoperative hemorrhage, and intra-abdominal abscesses occurred more often in sarcopenic patients. Surgical complications were also noted more frequently when sarcopenic obesity was present. Preoperative nutritional prehabilitation seems to reduce the risk of postoperative complications. However, more prospective studies are needed.

CONCLUSIONS

Sarcopenia and sarcopenic obesity were associated with a higher incidence of multiple postoperative complications, including POPF (type B and C), DGE, hemorrhage, and infectious complications.

Association of preoperative CT-scan features and clinically relevant postoperative pancreatic fistula after pancreaticoduodenectomy: a meta-analysis

BACKGROUND

Clinically relevant postoperative pancreatic fistula (CR-POPF) is a significant complication after pancreaticoduodenectomy. CR-POPF is associated with various adverse outcomes, including high mortality rates. Identifying complication predictors for CR-POPF, such as preoperative CT scan features, including pancreatic attenuation index (PAI) and pancreatic duct diameter (PDD), is critical. This systematic review and meta-analysis consolidate existing literature to assess the impact of these variables on CR-POPF risk.

METHODS

Our comprehensive search, conducted in May 2023, covered PubMed, Scopus, Embase, and Web of Science databases. Inclusion criteria encompassed peer-reviewed cohort studies on pancreaticoduodenectomy, focusing on preoperative CT scan data. Case reports, case series, and studies reporting distal pancreatectomy were excluded. The quality assessment of included articles was done using New-Castle Ottawa Scale for cohort studies. Statistical analysis was carried out using Review Manager 5. This study was registered at the International Prospective Register of Systematic Reviews database (PROSPERO) on 12 May 2023 (registration number: CRD42023414139).

RESULTS

We conducted a detailed analysis of 38 studies with 7393 participants. The overall incidence of CR-POPF was 24%. Multiple linear regression analyses revealed that PDD and pancreatic parenchymal thickness were significantly associated with CR-POPF.

CONCLUSION

Our systematic review and meta-analysis shed light on CT scan findings for predicting CR-POPF after Whipple surgery. Age, PDD, and pancreatic parenchymal thickness significantly correlate with CR-POPF.

Deep learning-based prediction of post-pancreaticoduodenectomy pancreatic fistula

Postoperative pancreatic fistula is a life-threatening complication with an unmet need for accurate prediction. This study was aimed to develop preoperative artificial intelligence-based prediction models. Patients who underwent pancreaticoduodenectomy were enrolled and stratified into model development and validation sets by surgery between 2016 and 2017 or in 2018, respectively. Machine learning models based on clinical and body composition data, and deep learning models based on computed tomographic data, were developed, combined by ensemble voting, and final models were selected comparison with earlier model. Among the 1333 participants (training, n = 881; test, n = 452), postoperative pancreatic fistula occurred in 421 (47.8%) and 134 (31.8%) and clinically relevant postoperative pancreatic fistula occurred in 59 (6.7%) and 27 (6.0%) participants in the training and test datasets, respectively. In the test dataset, the area under the receiver operating curve [AUC (95% confidence interval)] of the selected preoperative model for predicting all and clinically relevant postoperative pancreatic fistula was 0.75 (0.71-0.80) and 0.68 (0.58-0.78). The ensemble model showed better predictive performance than the individual ML and DL models.

Sarcopenia and visceral fat in patients with incisional hernia after urgent laparotomy

PURPOSE

Various risk factors have been associated with the development of incisional hernia (IH). Some recent papers underlined that visceral fat could be a reliable indicator. Another risk factor which is of increasing clinical interest is sarcopenia. Recent studies have identified it as an independent predictor of poor postoperative outcomes following abdominal surgery. We aimed to investigate the role of visceral fat and skeletal muscle as emerging risk factors for IH after urgent laparotomy.

METHODS

Patients aged 18 years or older who underwent urgent median laparotomy and with continuous direct suturing of the laparotomy were included. They were categorized into two groups: those with a median IH and those without IH at 12-month follow-up. Demographic data were prospectively collected while CT scans were retrospectively reviewed. The data were compared among two groups.

RESULTS

From January 2018 to May 2021, 364 patients underwent urgent surgery in our Department, of whom 222 were aged >18 years old and underwent median laparotomy. Forty-four patients had diagnosis of median IH, while 41 patients without IH were identified as the control group. Statistically significant differences emerged for BMI and for the area of visceral fat. The association with the presence/absence of sarcopenia was not significant.

CONCLUSION

Even when surgery is performed in urgent settings, it could be important to identify patients at risk, especially as CT scans are generally available for all patients with urgent abdominal disease.

Prediction of postoperative pancreatic fistula and pancreatitis after pancreatoduodenectomy or distal pancreatectomy: A review

BACKGROUND AND OBJECTIVE

Postoperative pancreatic fistula (POPF) is the leading cause of morbidity and early mortality in patients undergoing pancreatic resection. In addition, recent studies have identified postoperative acute pancreatitis (POAP) as an independent contributor to morbidity. Most perioperative mitigation strategies experimented for POPF have been shown to be in vain with no consensus on the best perioperative management. Clinical prediction models have been developed with the hope of identifying high POPF risk patients with the leading idea of finding subpopulations possibly benefiting from pre-existing or novel mitigation strategies. The aim of this review was to map out the existing prediction modeling studies to better understand the current stage of POPF prediction modeling, and the methodology behind them.

METHODS

A narrative review of the existing POPF prediction model studies was performed. Studies published before September 2022 were included.

RESULTS

While the number of POPF prediction models for pancreatoduodenectomy has increased, none of the currently existing models stand out from the crowd. For distal pancreatectomy, two unique POPF prediction models exist, but due to their freshness, no further external validation or adoption in clinics or research has been reported. There seems to be a lack of adherence to correct methodology or reporting guidelines in most of the studies, which has rendered external validity-if assessed-low. Few of the most recent studies have demonstrated preoperative assessment of pancreatic aspects from computed tomography (CT) scans to provide relatively strong predictors of POPF.

CONCLUSIONS

Main goal for the future would be to reach a consensus on the most important POPF predictors and prediction model. At their current state, few models have demonstrated adequate transportability and generalizability to be up to the task. Better understanding of POPF pathophysiology and the possible driving force of acute inflammation and POAP might be required before such a prediction model can be accessed.

A computed tomography study investigating the effects of botulinum toxin injections prior to complex abdominal wall reconstruction

OBJECTIVE

To explore how intramuscular injection of botulinum toxin A (BTA) affects the lateral abdominal wall (LAW) musculature, abdominal- and hernia dimensions, and muscle structure on computed tomography (CT) in patients scheduled for complex abdominal wall reconstruction (CAWR).

METHODS

Retrospective analysis of prospectively registered patients who received bilateral intramuscular BTA injections into all three muscles of the LAW. Only patients for which a CT was available before and 3-6 weeks after BTA treatment prior to surgery were analyzed.

RESULTS

Fifty-two patients were analyzed. Median hernia width in all patients decreased with 0.4 cm (IQR - 2.1;0.6) (p = 0.023). Median intra-abdominal transverse diameter increased with 0.9 cm (IQR - 0.2;3.3) (p = 0.001) and the intra-abdominal anterior-posterior diameter decreased with 0.5 cm (IQR - 1.3;0.5) (p = 0.017), making the abdomen more oval. Median LAW muscle length increased with 0.9 cm (IQR 0.0;2.4) per side (p < 0.001), muscle thickness decreased with 0.5 cm (IQR - 0.8;- 0.2) (- 25.0%) per side (p < 0.001), and muscle mass decreased with 3.9 cm2 (IQR - 6.4;-1.5) (- 15.8%) per side (p < 0.001). Median HU of the psoas muscles (density) increased with 4.8 HU (IQR 0.4;9.7) (10.3%) per side (p < 0.001). Effects of BTA were more pronounced in patients with a loss of domain (LoD) ≥ 20%.

CONCLUSIONS

The main effect of BTA injections is elongation and thinning of the LAW muscles, more than a decrease in hernia width. Concomitantly, the abdomen becomes more oval. An increase of psoas muscles density is seen, associated with offloading of the LAW muscles. Patients with large LoD have a proportionally higher effect of BTA.

High prevalence of sarcopenia and myosteatosis in patients undergoing hemodialysis

BACKGROUND AND PURPOSE

Sarcopenia is highly prevalent (28.5-40.3%) in patients undergoing hemodialysis and leads to poor clinical outcomes. However, the association between muscle quality and sarcopenia in patients receiving hemodialysis remains unclear. Therefore, we aimed to explore the association between muscle cross-sectional area (CSA) and proton-density fat-fraction (PDFF) in patients with sarcopenia undergoing hemodialysis.

METHODS

Seventy-six patients undergoing hemodialysis for > 3 months were enrolled. Their handgrip strength (HGS), short physical performance battery (SPPB) performance, and appendicular skeletal muscle mass index (ASMI) were measured. Sarcopenia was defined using the Asian Working Group for Sarcopenia 2019 consensus update. All patients underwent quantitative magnetic resonance imaging. CSA and PDFF were measured for the thigh, trunk, and gluteus muscles.

RESULTS

The prevalence of probable, confirmed, and severe sarcopenia in this study was 73.7%, 51.3%, and 22.4%, respectively. Older age (OR: 1.061, P < 0.003); lower body mass index (BMI) (OR: 0.837, P = 0.008), albumin (OR: 0.765, P = 0.004), prealbumin (OR: 0.987, P = 0.001), predialysis blood urea nitrogen (BUN) (OR: 0.842, P < 0.001), predialysis creatinine (OR: 0.993, P < 0.001), phosphorus (OR: 0.396, P = 0.047); lower CSA of the thigh (OR: 0.58, P = 0.035), third lumbar (L3) trunk (OR: 0.37, P = 0.004), gluteus minimus and medius (OR: 0.28, P = 0.001), and gluteus maximus (OR: 0.28, P= 0.001); and higher PDFF of the thigh (OR: 1.89, P = 0.036) and L3 trunk (OR: 1.71, P = 0.040) were identified as sarcopenia risk factors. The gluteus minimus and medius CSA was lower in patients with sarcopenia than in those without after adjusting for age and BMI (OR: 0.37, P = 0.017). Higher thigh (P = 0.031) and L3 trunk (P = 0.006) muscle PDFF were significantly associated with lower HGS. Furthermore, higher thigh (P = 0.011) and L3 trunk (P = 0.010) muscle PDFF were also inversely correlated with lower ASMI.

CONCLUSION

Our findings demonstrate the high prevalence of sarcopenia and myosteatosis in patients undergoing hemodialysis and might trigger a paradigm shift in intervention strategies for patients receiving hemodialysis.

Visceral adipose tissue is a better predictor than BMI in the alternative Fistula Risk Score in patients undergoing pancreatoduodenectomy

BACKGROUND

Muscle attenuation (MA) and visceral adipose tissue (VAT) have not yet been included in the currently used alternative Fistula Risk Score (a-FRS). The aim of this study was to examine the added value of these parameters as predictors of clinically relevant postoperative pancreatic fistula (CR-POPF) in the a-FRS after pancreatoduodenectomy compared to Body Mass Index (BMI).

METHODS

A single center retrospective cohort study was performed in patients who underwent pancreatoduodenectomy between 2009 and 2018. The a-FRS model was reproduced, MA and VAT were both combined and separately added to the model instead of BMI using logistic regression analysis. Model discrimination was assessed by ROC-curves.

RESULTS

In total, 329 patients were included of which 55 (16.7%) developed CR-POPF. The a-FRS model showed an AUC of 0.74 (95%CI: 0.68-0.80). In this model, BMI was not significantly associated with CR-POPF (p = 0.16). The MA + VAT model showed an AUC of 0.81 (95%CI: 0.75-0.86). VAT was significantly associated with CR-POPF (per cm², OR: 1.01; 95%CI: 1.00-1.01; p < 0.001). The AUC of the MA + VAT model differed significantly from the AUC of the a-FRS model (p = 0.001).

CONCLUSION

Visceral adipose tissue is of added value in the a-FRS compared to BMI in predicting CR-POPF in patients undergoing pancreatoduodenectomy.

Sarcopenia and Risk of Pancreatic Fistula after Pancreatic Surgery: A Systematic Review

Postoperative pancreatic fistula (POPF) is one of the most critical complications after pancreatic surgery. The relationship between sarcopenia and outcomes following this type of surgery is debated. The aim of this review was to assess the impact of sarcopenia on the risk of POPF. A literature search was performed using the PubMed database and the reference lists of relevant articles to identify papers about the impact of sarcopenia on POPF in pancreatic surgery. Twenty-one studies published between 2016 and 2021 with a total of 4068 patients were included. Some studies observed a significant difference in the incidence of POPF between the sarcopenic and non-sarcopenic patients undergoing pancreatoduodenectomy. Interestingly, there was a trend of a lower POPF rate in sarcopenic patients than in non-sarcopenic patients. Only one study included patients undergoing distal pancreatectomy specifically. The role of sarcopenia in surgical outcomes is still unclear. A combination of objective CT measurements could be used to predict POPF. It could be assessed by routine preoperative staging CT and could improve preoperative risk stratification in patients undergoing pancreatic surgery.

Linear Skeletal Muscle Index and Muscle Attenuation May Be New Prognostic Factors in Colorectal Carcinoma Treated by Radical Resection

Objective

This study evaluated the association between body composition and clinical parameters and prognosis in patients with colorectal cancer (CRC) treated by radical resection.

Methods

Baseline data on patient age, body mass index (BMI), bowel obstruction and tumor-related factors were collected retrospectively. Body composition parameters such as visceral fat area (VFA), total abdominal muscle area (TAMA), muscle attenuation (MA), posterior renal fat thickness (PPNF) and intermuscular fat area (IMF) are measured using Computed tomography (CT) scans. We also propose a new predictor of linear skeletal muscle index (LSMI) that can be easily measured clinically at CT. Follow-up endpoints were disease-free survival and all-cause death. We follow up with patients in hospital or by telephone. Univariate and multifactorial Cox proportional hazards analyses were performed to identify risk factors associated with prognosis. Survival analysis was performed using the Kaplan-Meier method and a nomogram was established to predict survival.

Results

A total of 1761 patients (median age 62 years) with CRC were enrolled in our study, of whom 201 had intestinal obstruction and 673 had a BMI > 24.0. Among all patients, the 3- and 5-year disease-free survival rates were 84.55% and 68.60% respectively, and the overall survival rates were 88.87% and 76.38%. Overall survival was significantly correlated with MA, LSMI, SMI, Tumor size, N stage, metastasis and adjuvant therapy by Cox regression analysis (p < 0.05). The risk of tumor progression was significantly associated with MA, VFA, LSMI, SMI, Male, N stage, metastasis and adjuvant therapy (p < 0.05). In addition, based on the Chinese population, we found that female patients with MA < 30.0 HU, LSMI < 18.2, and SMI < 38.0 had a worse prognosis, male patients with MA < 37.6 HU, LSMI < 21.9, and SMI < 40.3 had a poorer prognosis.

Conclusion

Our findings suggest that linear skeletal muscle index and MA can be used as new independent predictors for colorectal cancer patients treated with radical surgery, and that baseline data such as body composition parameters, LSMI and tumor-related factors can collectively predict patient prognosis. These results could help us to optimize the management and treatment of patients after surgery.

Prognostic significance of skeletal muscle decrease in unresectable pancreatic cancer: Survival analysis using the Weibull exponential distribution model

BACKGROUND/OBJECTIVES

Decrease in skeletal muscle mass and function is associated with a poor prognosis following surgical resection of pancreatic ductal adenocarcinomas (PDAs). This study evaluated whether skeletal muscle mass decrease affects PDA outcomes.

METHODS

Data of 112 patients with advanced and unresectable PDA who underwent chemotherapy in a single institution were retrospectively analyzed. Information on age, sex, hematological investigations, including systemic inflammation-based markers and nutritional assessment biomarkers, and imaging parameters of skeletal muscle mass and visceral adipose tissue were retrieved from the patients' medical records. The efficiency of the Cox, Weibull, and standardized exponential models were compared using hazard ratios and the Akaike Information Criterion (AIC).

RESULTS

Results from the Weibull, Cox, and standardized exponential model analyses indicated that low skeletal muscle mass, Eastern Cooperative Oncology Group performance status (PS), and the requirement of biliary drainage were associated with the highest risk of death, followed by carcinoembryonic antigen (CEA) levels and the presence of ascites. The AIC value from the four significant parameters was lowest for the Weibull-exponential distribution (222.3) than that of the Cox (653.7) and standardized exponential models (265.7). We developed a model for estimating the 1-year survival probability using the Weibull-exponential distribution.

CONCLUSIONS

Low-skeletal muscle index, PS, requirement of biliary drainage, CEA levels, and presence of ascites are independent factors for predicting poor patient survival after chemotherapy. Improved survival modeling using a parametric approach may accurately predict the outcome of patients with advanced-stage PDA.

Oral Nutritional Supplements and Enteral Nutrition in Patients with Gastrointestinal Surgery

Nowadays, patients undergoing gastrointestinal surgery are following perioperative treatment in enhanced recovery after surgery (ERAS) protocols. Although oral feeding is supposed not to be stopped perioperatively with respect to ERAS, malnourished patients and inadequate calorie intake are common. Malnutrition, even in overweight or obese patients, is often underestimated. Patients at metabolic risk have to be identified early to confirm the indication for nutritional therapy. The monitoring of nutritional status postoperatively has to be considered in the hospital and after discharge, especially after surgery in the upper gastrointestinal tract, as normal oral food intake is decreased for several months. The article gives an overview of the current concepts of perioperative enteral nutrition in patients undergoing gastrointestinal surgery.

Body Composition Parameters May Be Prognostic Factors in Upper Urinary Tract Urothelial Carcinoma Treated by Radical Nephroureterectomy

Objective

This study assessed the association between body composition and prognosis of patients with upper urinary tract urothelial carcinoma (UTUC) patients treated by radical nephroureterectomy.

Methods

We retrospectively collected baseline data on age, sex, body mass index (BMI), hypertension, diabetes, and tumor-related factors. Computed tomography (CT) scans were performed to measure body composition parameters such as muscle attenuation (MA), total abdominal muscle area (TAMA), visceral fat area (VFA), intermuscular fat area (IMF), and lateral/posterior perirenal fat thickness (L/P PNF), visceral fat density (VD), and subcutaneous fat density (SD). Patient follow-up was conducted via telephone or in the clinic. The endpoints of follow-up were all-cause death, local progression or distant metastasis. Survival analysis was analyzed using the Kaplan-Meier method, and risk factors associated with prognosis were identified using univariate and multivariate Cox proportional hazard analyses.

Results

Among the 273 UTUC patients (median age, 68 years) enrolled in our study, 102 had a BMI > 24.0, 100 suffered from diabetes, and 120 had hypertension. A large proportion of patients (189) had high grade tumors. Across all patients, 1- and 3-year rates for overall survival were 86.45% and 75.55%; local progression-free survival, 92.11% and 89.67%; and distant metastasis-free survival, 85.23% and 80.17%. Based on the Cox regression analysis, MA, IMF, TAMA, TPA, TPT, APT, SMI and PMI significantly reduced the risk of local progression (p < 0.05), while PPNF = 1 point reduced the risk of distant metastasis (p < 0.05). Overall survival was significantly associated with MA, TAMA, and SMI (p < 0.05).

Conclusion

Our findings illustrate that body composition parameters can act as independent predictors of prognosis in UTUC patients who underwent RNU. These results can help improve stratification of patients and optimize postoperative treatment.

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.

Effects of Hyperthyroidism on Adipose Tissue Activity and Distribution in Adults

Background: Positron emission tomography (PET) has provided evidence that adult humans retain metabolically active brown adipose tissue (BAT) depots. Thyroid hormones (TH) stimulate BAT thermogenesis by central and peripheral mechanisms. However, the effect of hyperthyroidism on BAT activity and BAT volume in humans is yet not fully understood. The aim of this study was to investigate the effect of TH on (i) the metabolic activity of brown and white adipose tissue (WAT) depots, (ii) on abdominal visceral and subcutaneous adipose tissue area, and (iii) on serum levels of metabolically active cytokines. Methods: Nineteen patients with overt hyperthyroidism were investigated through repeated 2-[¹⁸F]fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (2-[¹⁸F]FDG PET/CT) in the hyperthyroid and in the euthyroid state. The 2-[¹⁸F]FDG uptake was calculated as standard uptake ratio with blood pool as reference. Fat areas were quantified by means of CT segmentation. Serum levels of fetuin A and B, fibroblast growth factor 21, adipocyte fatty acid-binding protein (AFABP), retinol-binding protein 4, pro-enkephalin, pro-neurotensin, and neuregulin 4 were determined in the hyperthyroid and in the euthyroid state for each subject. Results: 2-[¹⁸F]FDG uptake was increased in the hyperthyroid state in BAT in comparison with the euthyroid phase (p = 0.001). There was no correlation between serum free triiodothyronine (fT3) and free thyroxine (fT4) levels and 2-[¹⁸F]FDG uptake in BAT or WAT. In the hyperthyroid state, fT3 levels were positively associated with skeletal muscle standardized uptake value ratios. Areas of visceral adipose tissue and skeletal muscle were significantly decreased in hyperthyroidism. AFABP levels correlated positively with fT3 (p = 0.031, β = 0.28) and fT4 (p = 0.037, β = 0.27) in the hyperthyroid state. Conclusions: Our results suggest that the contribution of increased TH levels to the glucose uptake of BAT and WAT is low compared with that of the skeletal muscle. Hyperthyroid subjects have reduced areas of visceral adipose tissue and increased AFABP levels.

Skeletal muscle depletion and nutrition support affected postoperative complications in patients who underwent pancreatoduodenectomy

BACKGROUND

Body composition has been shown closely related to the outcome in surgical patients. The aim of the present study was to investigate whether preoperative skeletal muscle condition and postoperative nutrition would affect major complications in patients underwent pancreaticoduodenectomy (PD).

METHODS

This retrospective study included 265 patients underwent PD. Body composition data was extracted from the L3 level of the preoperative CT scan. Univariable and multivariable regression analyses were performed to investigate correlations between body composition data and postoperative complications. Furthermore, a subgroup analysis was conducted to explore the relationship between postoperative nutrition strategy and the outcome.

RESULTS

Of all the 265 patients, major complications occurred in 81 patients (30.6%). Cutoff values for skeletal muscle depletion were defined by ROC curve analysis from postoperative complications in skeletal muscle index (SMI) (male 47.32 cm²/m² and female 40.65 cm²/m²). Univariable analysis and multivariable regression revealed age (OR 1.49, 95% CI 1.22-1.83, p = 0.026), SMI (OR 0.77, 95% CI 0.51-0.94, p = 0.015) and skeletal muscle density (SMD) (OR 0.85, 95% CI 0.64-1.03, p = 0.029) were independent predictors for major complications. Subgroup analysis showed the initial parenteral nutrition time (IPNT) (OR 1.89, 95% CI 1.43-2.49, p = 0.032) and average protein delivery (APD) (OR 0.76, 95% CI 0.53-0.89, p = 0.021) were significantly associated with major complications in patients with lower SMI.

CONCLUSIONS

Preoperative skeletal muscle index and density were independently associated with major complications in patients underwent PD. In patients with lower SMI, early parenteral nutrition and higher protein delivery were related to better outcome.

Muscle density discriminates hip fracture better than computed tomography X-ray absorptiometry hip areal bone mineral density

BACKGROUND

Muscle weakness is a key factor in the increase risk of falls and might also play a significant role in the increase of risk of hip fracture. Computed tomography-measured muscle size and muscle density are well-established imaging biomarkers used in studies of physical function, frailty or cancer, but limited to hip fracture. In particular, it is warranted to have a better understanding of the performance of muscle size and density in the discrimination of acute hip fractures. We also aim to determine age-related differences of muscle size and density in healthy controls and hip fracture patients.

METHODS

Four hundred thirty-eight low-energy acute hip fracture cases and 316 healthy controls from the China Action on Spine and Hip Status study were included in the study. Muscle cross-sectional area and density were measured for the gluteus maximus and gluteus medius and minimus. Areal bone mineral density (aBMD) of the femoral neck and total hip was measured. Using propensity score matching, we generated three samples with cases and controls matched for age, body mass index, and gender: femoral neck fracture (FNF), intertrochanteric fracture (ITF), and any hip fracture vs. controls, respectively.

RESULTS

Handgrip strength, gluteus muscle area and density, and bone parameters of the matched hip fracture groups were lower than those of the correspondence control groups, respectively (P < 0.05). The univariate analysis showed that associations of aBMD with FNF and with ITF were significantly weaker than associations between fracture and muscle parameters. Gluteus medius and minimus muscle density showed the highest areas under the curve (AUC) with FNF (0.88, 95% confidence interval, 0.85-0.92) and trochanteric fracture (0.95, 95% confidence interval, 0.92-0.97). The model including all muscle and bone parameters provided the highest AUC (FNF: AUC 0.912; ITF: AUC 0.958), and AUC results of another selected model without muscle density showed that association with fracture significantly dropped (FNF: AUC 0.755; ITF: AUC 0.858). Separate results for the two age groups younger and older than 70 years showed no age-related significant differences in discriminate models.

CONCLUSIONS

Muscle density performs better than aBMD from hip computed tomography X-ray absorptiometry and muscle size in discrimination of hip fracture. Combination of aBMD and muscle density provided the best discrimination. The integration of muscle assessments may trigger a paradigm shift in hip fracture prediction. Gluteus muscle density should also be evaluated as treatment outcome.

[Predictors of external pancreatic fistulae after pancreatic resection]

Despite a significant decrease in postoperative mortality after pancreatic resections in recent years (5.2-15% after pancreatoduodenectomy and about 5% after distal pancreatectomy), incidence of postoperative complications remains high (30-50% and 22-50%, respectively). Postoperative pancreatic fistula is one of the most common and formidable complications. Currently, most authors use the classification proposed by the International Study Group for Pancreatic Fistula (biochemical failure, fistula type B and C). Prediction of the risk of postoperative fistula is still a complex and unresolved problem of modern surgical pancreatology. According to the literature, the main risk factors of postoperative pancreatic fistulae are obesity and high body mass index, concomitant cardiovascular diseases, no neoadjuvant chemo- and radiotherapy, soft pancreatic texture, narrow pancreatic duct, no fibrotic changes in parenchyma, adipose infiltration of the pancreas, advanced intraoperative blood loss, as well as center experience. Most often, magnetic resonance imaging, computed tomography, ultrasound elastography and various multivariate risk assessment systems are used to estimate the risk of pancreatic fistulae. However, a generally accepted technique does not exist. This manuscript is devoted to analysis of risk factors of postoperative pancreatic fistulae and diagnostic methods for assessment of this risk.

Feasibility of computed tomography-based assessment of skeletal muscle mass in hemodialysis patients

BACKGROUND

Sarcopenia is a major health issue especially in patients on maintenance hemodialysis. Low skeletal muscle mass is included in the diagnostic criteria for sarcopenia. The skeletal muscle mass is usually evaluated by modalities such as bioimpedance analysis (BIA) or dual-energy X-ray absorptiometry, however the assessment of skeletal muscle mass using computed tomography (CT) images has not been established. The purpose of the study was to investigate the feasibility of the assessment of skeletal muscle mass using CT images in hemodialysis patients.

METHODS

Skeletal muscle mass index (SMI) was measured by BIA and psoas muscle index (PMI) was measured by cross-sectional CT images in 131 patients. The relationship between SMI and PMI and the diagnostic ability of PMI for low muscle mass were evaluated. Furthermore, the patients were followed up and long-term survival in patients with low and high PMI were compared.

RESULTS

PMI measured at the L3 vertebral level was strongly correlated with SMI (r = 0.597, p < 0.001). Age, sex, and SMI were the influencing factors for PMI. Patients with low PMI showed higher incidence rates of mortality during the follow up.

CONCLUSIONS

PMI assessed by CT image can be an alternative to BIA in patients on hemodialysis.

Muscle Density, but Not Size, Correlates Well With Muscle Strength and Physical Performance

OBJECTIVES

There is increasing evidence that muscle volume and mass are poor predictors of muscle strength and physical performance. Other assessments of muscle quality such as skeletal muscle density measured by computed tomography (CT) may be more important. The aim of this study was to explore associations of muscle size and density with handgrip strength (HGS) and the Timed Up and Go test (TUG). We also hypothesized that the strength of these associations would depend on the specific muscle of muscle group, namely trunk, hip, and mid-thigh muscles.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

University hospital; 316 volunteers aged 59 to 85 years.

METHODS

HGS, TUG, and quantitative CT imaging of the lumber, hip, and mid-thigh were performed in volunteers. From the CT images, cross-sectional area and attenuation were determined for the gluteus muscle, trunk muscle at vertebrae L2 level, and mid-thigh muscle.

RESULTS

In men and women, associations of muscle area with TUG were insignificant after adjustment for age, height, and weight. Associations with HGS were only significant in men for the gluteus maximus and the mid-thigh but slopes were rather low (β < 0.20). Associations between muscle density and TUG/HGS were more pronounced, in particular for HGS. After adjustment, associations with TUG were significant in women for the gluteus maximus and trunk muscle even (β -0.06, P .001 and β -0.07, P .031, respectively).

CONCLUSIONS AND IMPLICATIONS

Muscle density is more strongly associated with muscle strength than muscle size andin women muscle density was also more strongly associated than muscle size with physical performance. Therefore, muscle density may represent a more clinically meaningful surrogate of muscle performance than muscle size. Muscle density measurements of trunk and gluteus muscles can be easily obtained from routine CT scan and, therefore, may become an important measurement to diagnose and screen for sarcopenia.

The clinical relevance and mechanism of skeletal muscle wasting

Skeletal muscle wasting occurs in both chronic and acute diseases. Increasing evidence has shown this debilitating process is associated with short- and long-term outcomes in critical, cancer and surgical patients. Both muscle quantity and quality, as reflected by the area and density of a given range of attenuation in CT scan, impact the patient prognosis. In addition, ultrasound and bioelectrical impedance analysis (BIA) are also widely used in the assessment of body composition due to their bedside viability and no radioactivity. Mechanism researches have revealed complicated pathways are involved in muscle wasting, which include altered IGF1-Akt-FoxO signaling, elevated levels of myostatin and activin A, activation of NF-κB pathway and glucocorticoid effects. Particularly, central nervous system (CNS) has been proven to participate in regulating muscle wasting in various conditions, such as infection and tumor. Several promising therapeutic agents have been under developing in the treatment of muscle atrophy, such as myostatin antagonist, ghrelin analog, non-steroidal selective androgen receptor modulators (SARMs). Notably, nutritional therapy is still the fundamental support in combating muscle wasting. However, the optimizing and tailored nutrition regimen relies on accurate metabolism measurement and large clinical trials in the future. Here, we will discuss the current understanding of muscle wasting and potential treatment in clinical practice.

The emerging role of sarcopenia as a prognostic indicator in patients undergoing abdominal wall hernia repairs: a systematic review of the literature

BACKGROUND

There is strong evidence suggesting that excessive fat distribution, for example, in the bowel mesentery or a reduction in lean body mass (sarcopenia) can influence short-, mid-, and long-term outcomes from patients undergoing various types of surgery. Body composition (BC) analysis aims to measure and quantify this into a parameter that can be used to assess patients being treated for abdominal wall hernia (AWH). This study aims to review the evidence linking quantification of BC with short- and long-term abdominal wall hernia repair outcomes.

METHODS

A systematic review was performed according to the PRISMA guidelines. The literature search was performed on all studies that included BC analysis in patients undergoing treatment for AWH using Medline, Google Scholar and Cochrane databases by two independent reviewers. Outcomes of interest included short-term recovery, recurrence outcomes, and long-term data.

RESULTS

201 studies were identified, of which 4 met the inclusion criteria. None of the studies were randomized controlled trials and all were cohort studies. There was considerable variability in the landmark axial levels and skeletal muscle(s) chosen for analysis, alongside the methods of measuring the cross-sectional area and the parameters used to define sarcopenia. Only two studies identified an increased risk of postoperative complications associated with the presence of sarcopenia. This included an increased risk of hernia recurrence, postoperative ileus and prolonged hospitalisation.

CONCLUSION

There is some evidence to suggest that BC techniques could be used to help predict surgical outcomes and allow early optimisation in AWH patients. However, the lack of consistency in chosen methodology, combined with the outdated definitions of sarcopenia, makes drawing any conclusions difficult. Whether body composition modification can be used to improve outcomes remains to be determined.

Assessing skeletal muscle radiodensity by computed tomography: An integrative review of the applied methodologies

Low-radiodensity skeletal muscle has been related to the degree of muscle fat infiltration and seems to be associated with worse outcomes. The aim of this study was to summarize the methodologies used to appraise skeletal muscle radiodensity by computed tomography, to describe the terms used in the literature to define muscle radiodensity and to give recommendations for its measurement standardization. An integrative bibliographic review in four databases included studies published until August 2019 in Portuguese, English or Spanish and performed in humans, adults and/or the elderly, of both sex, which investigated skeletal muscle radiodensity through computed tomography (CT) of the region between the third and fifth lumbar vertebrae and evaluated at least two muscular groups. One hundred and seventeen studies were selected. We observed a trend towards selecting all abdominal region muscle. A significant methodological variation in terms of contrast use, selection of skeletal muscle areas, radiodensity ranges delimitation and their cut-off points, as well as the terminologies used, was also found. The methodological differences detected are probably due to the lack of more precise information about the correlation between skeletal muscle radiodensity by CT and its molecular composition, among others. Therefore, until the gaps are addressed in future studies, authors should avoid arbitrary approaches when reporting skeletal muscle radiodensity, especially when it comes to prognosis inference. Studies using both CT and direct methods of muscle composition evaluation are encouraged, to enable the definition and validation of the best approach to classify fat-infiltrated muscle tissue, which will favour the nomenclature uniformization.

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.

Prognostic role of body composition parameters in gastric/gastroesophageal junction cancer patients from the EXPAND trial

BACKGROUND

Body fat and/or muscle composition influences prognosis in several cancer types. For advanced gastric and gastroesophageal junction cancer, we investigated which body composition parameters carry prognostic information beyond well-established clinical parameters using robust model selection strategy such that parameters identified can be expected to generalize and to be reproducible beyond our particular data set. Then we modelled how differences in these parameters translate into survival outcomes.

METHODS

Fat and muscle parameters were measured on baseline computed tomography scans in 761 patients with advanced gastric or gastroesophageal junction cancer from the phase III EXPAND trial, undergoing first-line chemotherapy. Cox regression analysis for overall survival (OS) and progression-free survival (PFS) included body composition parameters and clinical prognostic factors. All continuous variables were entered linearly into the model as there was no evidence of non-linear prognostic impact. For transferability, the final model included only parameters that were picked by Bayesian information criterion model selection followed by bootstrap analysis to identify the most robust model.

RESULTS

Muscle and fat parameters formed correlation clusters without relevant between-cluster correlation. Mean muscle attenuation (MA) clusters with the fat parameters. In multivariate analysis, MA was prognostic for OS (P < 0.0001) but not for PFS, while skeletal muscle index was prognostic for PFS (P = 0.02) but not for OS. Worse performance status Eastern Cooperative Oncology Group (ECOG 1/0), younger age (on a linear scale), and the number of metastatic sites were strong negative clinical prognostic factors for both OS and PFS. MA remained in the model for OS (P = 0.0001) following Bayesian information criterion model selection in contrast to skeletal muscle index that remained prognostic for PFS (P = 0.009). Applying stricter criteria for transferability, MA represented the only prognostic body composition parameter for OS, selected in >80% of bootstrap replicates. Finally, Cox model-derived survival curves indicated that large differences in MA translate into only moderate differences in expected OS in this cohort.

CONCLUSIONS

Among body composition parameters, only MA has robust prognostic impact for OS. Data suggest that treatment approaches targeting muscle quality are unlikely to prolong OS noticeably on their own in advanced gastric cancer patients, indicating that multimodal approaches should be pursued in the future.

Myosteatosis to predict inferior perioperative outcome in patients undergoing orthotopic liver transplantation

Muscle wasting and alterations of body composition are linked to clinical outcomes in numerous medical conditions. The role of myosteatosis in posttransplant outcomes remains to be determined. Here we investigated skeletal muscle mass and myosteatosis as prognostic factors in patients undergoing orthotopic liver transplantation (OLT). The data of 225 consecutive OLT recipients from a prospective database were retrospectively analyzed (May 2010-December 2017). Computed tomography-based skeletal-muscle-index (muscle mass), visceral-fat-area (visceral adiposity), and mean skeletal-muscle-radiation-attenuation (myosteatosis) were calculated using a segmentation tool. Cut-off values of myosteatosis resulted in a good stratification of patients into low- and high-risk groups in terms of morbidity (Clavien-Dindo ≥3b). Patients with myosteatosis had significantly higher complication rates (90-day Comprehensive Complication Index 68 ± 32 vs 44 ± 30, P < .001) and also displayed significantly longer intensive care (18 ± 25 vs 11 ± 21 days, P < .001) and hospital stay (56 ± 55 vs 33 ± 24 days, P < .001). Estimated costs were 44% higher compared to patients without myosteatosis. Multivariable analysis identified myosteatosis as an independent prognostic factor for major morbidity (odds ratio: 2.772, confidence interval: 1.516-5.066, P = .001). Adding myosteatosis to the well-established Balance-of-Risk-(BAR) score resulted in an increased prognostic value compared to the original BAR score. Myosteatosis may be a useful parameter to predict perioperative outcome in patients undergoing OLT, supporting the role of muscle quality (myosteatosis) over quantity (muscle mass) in this setting.