Predicting outcomes of abdominal surgical emergencies in the elderly population using a CT muscle gauge

The correlation between muscle loss and the severity of vascular stenosis in elderly patients with peripheral artery disease: a retrospective analysis utilizing computed tomography

BACKGROUND

Peripheral artery disease (PAD) is a globally prevalent atherosclerotic disease associated with an increased risk of cardiovascular and cerebrovascular diseases and a poor prognosis. Skeletal muscle loss (sarcopenia) is particularly common in patients with PAD and is closely associated with poor prognosis.

AIMS

The aim of this study was to evaluate the area, density and fat infiltration of skeletal muscle in patients with PAD by CT, and to analyze their relationship with the degree of vascular stenosis.

METHODS

A total of 233 PAD patients who underwent lower extremity CTA in Beijing Hospital were included in this study. Image segmentation was performed using Slice-O-Matic® software, and parameters such as skeletal muscle area, density, and fat infiltration were measured at L3, L4, mid-thigh, and maximum soft tissue cross section of the lower leg. At the same time, the degree of lower extremity arterial stenosis was evaluated by CTA. The lower extremity arterial stenosis severity was graded as 0 (0-30%), 1 (31-50%), 2 (51-70%), 3 (71-99%), or 4 (occlusion).Then the CTA-score was calculated by summing the stenosis scores of the abdominal aorta and the lower limb arteries.

RESULTS

Patients were categorized into high (n = 113) and low (n = 120) CTA score groups. Among males, those in the low score group had higher muscle indices at L3, though not statistically significant. However, thigh and calf muscle areas were significantly larger in low score males (P < 0.001). High score patients had greater intermuscular fat indices. Regression analysis indicated that vascular stenosis accounted for 5% of the variance in muscle mass, with SFA, PoA, and PTA stenosis having the strongest correlations.

DISCUSSION

Our study reveals how vascular stenosis affects muscle mass and composition in PAD patients, with the SFA, PoA, and PTA having the greatest impact due to their key role in lower limb blood supply. Severe stenosis leads to muscle mass reduction and increased fat infiltration, possibly due to chronic inflammation and oxidative stress. These findings highlight the need to address muscle health in PAD management, as targeting muscle atrophy and fat infiltration could enhance patient outcomes.

CONCLUSIONS

PAD severity had a significant effect on the muscles of the lower limbs, especially the stenosis of the SFA, PoA, and PTA. CT evaluation provides a new perspective for understanding muscle loss in patients with PAD.

Psoas muscle gauge and adverse clinical outcomes in patients on hemodialysis

BACKGROUND

The relationship between the psoas muscle gauge (PMG), a combined sarcopenia indicator obtained from psoas muscle index (PMI) and psoas muscle density (PMD), and adverse clinical outcomes in patients on hemodialysis remains unclear. We examined whether psoas muscle gauge could predict all-cause mortality and new cardiovascular events more accurately than psoas muscle index in these patients.

METHODS

We retrospectively included 217 hemodialysis patients who underwent abdominal computed tomography. We calculated the psoas muscle gauge (arbitrary unit [AU]) at the fourth lumbar vertebra level as follows: PMI (cm2/m2) × PMD (Hounsfield units). We categorized the patients into higher and lower psoas muscle gauge groups based on sex-specific cutoffs obtained from the young Asian population. The outcomes were death and new cardiovascular events.

RESULTS

The psoas muscle gauge cutoffs were set at 231.1 and 328.8 AU in women and men, respectively. Eighty-five deaths and 95 new cardiovascular events occurred during the follow-up period of 4.4 (2.4-7.3) years. The 5-year survival rates were 59.2% and 94.9% in the lower and higher psoas muscle gauge groups, respectively (p < 0.0001). Moreover, after adjusting for sex and age, history of cardiovascular disease, C-reactive protein, modified creatinine index, and geriatric nutritional risk index, lower psoas muscle gauge was independently associated with increased all-cause death and new cardiovascular events (adjusted hazard ratio (aHR) 7.65; 95% confidence interval (CI) 2.37-24.66 and aHR 2.98; 95% CI 1.54-5.75, respectively). The concordance index (C-index) for predicting all-cause mortality and new cardiovascular events significantly improved when either psoas muscle index or psoas muscle gauge were added to the baseline risk model. Additionally, the C-index of the psoas muscle gauge-added model was significantly higher than that of the psoas muscle index-added model (0.815 vs. 0.784, p = 0.026) only when predicting all-cause mortality.

CONCLUSIONS

Psoas muscle gauge accurately predicted the risk of all-cause mortality and new cardiovascular events in patients undergoing hemodialysis. For predicting all-cause mortality, psoas muscle gauge may be recommended compared to psoas muscle index.

Sarcopenia in trauma patients: A systematic review and meta-analysis

Sarcopenia is associated with poor prognosis and mortality following injury. This systematic review and meta-analysis aimed to analyze diagnostic criteria for sarcopenia, as well as to assess its prevalence and impact on health outcomes among trauma patients. We conducted a literature search on MEDLINE, EMBASE, and the Cochrane Library from inception to June 2023. A total of 27 studies were included, involving 8692 individuals (55.5 % men) with a mean age ranging from 42.2 to 80.5 years. The pooled prevalence of sarcopenia in trauma patients was 36.0 % [95 % confidence interval (CI): 29.1-43.0 %, I2 = 97.8 %], with a 39.3 % prevalence (95 % CI: 31.0-48.5 %, I2 = 96.8 %) in men and a 39.0 % prevalence (95 % CI: 31.4-46.2 %, I2 = 94.4 %) in women. Trauma patients with sarcopenia were more prone to complications [risk ratio (RR): 1.16, 95 % CI: 1.03-1.31, I2 = 45.8 %] and less able to discharge independently (RR: 0.74, 95 % CI: 0.63-0.86, I2 = 33.3 %). The risk of death in trauma patients with sarcopenia was higher than in non-sarcopenic patients [hazard ratio (HR): 1.64, 95 % CI: 1.31-2.04]. Sarcopenia is commonly present in trauma patients and has a negative impact on prognosis. Early assessment and interventions for sarcopenia should be conducted in trauma patients.

The Emerging Role and Clinical Applications of Morphomics in Diagnostic Imaging

Analytic morphomics refers to the accurate measurement of specific biological markers of human body composition in diagnostic medical imaging. The increasing prevalence of disease processes that alter body composition including obesity, cachexia, and sarcopenia has generated interest in specific targeted measurement of these metrics to possibly prevent or reduce negative health outcomes. Typical morphomic measurements include the area and density of muscle, bone, vascular calcification, visceral fat, and subcutaneous fat on a specific validated axial level in the patient's cross-sectional diagnostic imaging. A distinct advantage of these measurements is that they can be made retrospectively and opportunistically with pre-existing datasets. We provide a narrative review of the current state of art in morphomics, but also consider some potential future directions for this exciting field. Imaging based quantitative assessment of body composition has enormous potential across the breadth and scope of modern clinical practice. From risk stratification to treatment planning, and outcome assessment, all can be enhanced with the use of analytic morphomics. Moreover, it is likely that many new opportunities for personalized medicine will emerge as the field evolves. As radiologists, embracing analytic morphomics will enable us to contribute added value in the care of every patient.

Combining sarcopenia and ASA status to inform emergency laparotomy outcomes: could it be that simple?

BACKGROUND

Risk assessment for emergency laparotomy (EL) is important for guiding decision-making and anticipating the level of perioperative care in acute clinical settings. While established tools such as the American College of Surgeons National Surgical Quality Improvement Program calculator (ACS-NSQIP), the National Emergency Laparotomy Audit Risk Prediction Calculator (NELA) and the Portsmouth Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity calculation (P-POSSUM) are accurate predictors for mortality, there has been increasing recognition of the benefits from including measurements for frailty in a simple and quantifiable manner. Psoas muscle to 3rd lumbar vertebra area ratio (PM:L3) measured on CT scans was proven to have a significant inverse association with 30-, 90- and 365-day mortality in EL patients.

METHODS

A retrospective analysis was conducted of 500 patients admitted to four Australian hospitals who underwent EL during 2016-2017, and had contemporaneous abdomino-pelvic CT scans. Radiological sarcopenia was measured as PM:L3 ratios. ASC-NSQIP, NELA and P-POSSUM were retrospectively calculated. Univariate and multivariate logistic regression modelling was used to assess these ratios and scores, as well as American Society of Anaesthesiologists (ASA) classification separated into ASA I-III and IV/V (simplified ASA), as potential predictors of 30-, 90- and 365-day mortality.

RESULTS

PM:L3, simplified ASA, ACS-NSQIP, NELA and P-POSSUM were each statistically significant predictors of 30-day, 90-day and 365-day mortality (P < 0.001). Logistic regression models of 30-, 90- and 365-day mortality combining PM:L3 (P = 0.001) and simplified ASA (P < 0.001) exhibited AUCs of 0.838 (0.780, 0.896), 0.805 (0.751, 0.860) and 0.775 (0.729, 0.822), respectively, which were comparable to that of ACS-NSQIP and NELA.

CONCLUSION

Combining the semi-physiological parameter ASA classification with PM:L3 provides a quick and simple alternative to the more complex established risk assessment scores and is superior to PM:L3 alone.

Sarcopenia provides extra value outside the PULP score for predicting mortality in older patients with perforated peptic ulcers

BACKGROUND

Perforated peptic ulcer (PPU) remains challenging surgically due to its high mortality, especially in older individuals. Computed tomography (CT)-measured skeletal muscle mass is a effective predictor of the surgical outcomes in older patients with abdominal emergencies. The purpose of this study is to assess whether a low CT-measured skeletal muscle mass can provide extra value in predicting PPU mortality.

METHODS

This retrospective study enrolled older (aged ≥ 65 years) patients who underwent PPU surgery. Cross-sectional skeletal muscle areas and densities were measured by CT at L3 and patient-height adjusted to obtain the L3 skeletal muscle gauge (SMG). Thirty-day mortality was determined with univariate, multivariate and Kaplan-Meier analysis.

RESULTS

From 2011 to 2016, 141 older patients were included; 54.8% had sarcopenia. They were further categorized into the PULP score ≤ 7 (n=64) or PULP score > 7 group (n=82). In the former, there was no significant difference in 30-day mortality between sarcopenic (2.9%) and nonsarcopenic patients (0%; p=1.000). However, in the PULP score > 7 group, sarcopenic patients had a significantly higher 30-day mortality (25.5% vs. 3.2%, p=0.009) and serious complication rate (37.3% vs. 12.9%, p=0.017) than nonsarcopenic patients. Multivariate analysis showed that sarcopenia was an independent risk factor for 30-day mortality in patients in the PULP score > 7 group (OR: 11.05, CI: 1.03-118.7).

CONCLUSION

CT scans can diagnose PPU and provide physiological measurements. Sarcopenia, defined as a low CT-measured SMG, provides extra value in predicting mortality in older PPU patients.

CT-defined pectoralis muscle mass and muscle density are associated with mortality in acute pulmonary embolism. A multicenter analysis

BACKGROUND & AIMS

Computed tomography (CT) defined muscle mass can be used as a surrogate parameter for sarcopenia. The present study used thoracic CT to assess pectoralis muscle area and density as an imaging biomarker for prognosis of 30-day mortality in patients with acute pulmonary embolism (PE) METHODS: The clinical database was retrospectively screened for patients with thoracic CT in 3 centers. Pectoralis musculature was measured on axial slices of the thoracic CT at the level of T4 of contrast enhanced pulmonary angiography CT. Skeletal muscle area (SMA), skeletal muscle index (SMI), muscle density and gauge were calculated.

RESULTS

Overall, 981 patients (440 female, 44.9%) with a mean age of 63.5 ± 15.9 years were included into the study and 144 patients (14.6%) died within the 30-days period. Every pectoral muscle value was higher in survivors compared to non-survivors (exemplarily for SMI 9.9 ± 3.5 cm²/m² versus 7.8 ± 2.6 cm²/m², p < 0.001). Moreover, 91 patients were defined as hemodynamically instable (9.3%). Comparable, every pectoral muscle parameter was higher in patients with hemodynamically stable course compared to instable course. Different muscle variables are related to 30-day mortality: SMA, OR = 0.94 (95%CI= (0.92; 0.96), p < 0.001); SMI, OR = 0.78 (95%CI= (0.72; 0.84), p < 0.001); muscle density, OR = 0.96 (95%CI = (0.94; 0.97), p < 0.001); muscle gauge OR = 0.96 (95%CI = (0.94; 0.99), p < 0.001). SMI and muscle density were independently associated with 30-days mortality: SMI, OR = 0.81 (95%CI = (0.75; 0.88), p < 0.001); muscle density: OR = 0.96 (95%CI= (0.95; 0.98), p < 0.001).

CONCLUSION

Parameters of the pectoralis musculature are associated with 30-day mortality in patients with acute PE. These findings should lead to an independent validation study and ultimately to the inclusion into clinical routine as a prognostic factor.

Diagnostic Value of Sarcopenia Computed Tomography Metrics for Older Patients with or without Cancers with Gastrointestinal Disorders

OBJECTIVES

The diagnostic utility of poor body composition measures in sarcopenia remains unclear. We hypothesize that the skeletal muscle gauge [combination of skeletal muscle index (SMI) and skeletal muscle density (SMD); SMG = SMI × SMD] would have significant diagnostic and predictive value in certain muscle regions and populations.

DESIGN

Prospective cross-sectional study.

SETTING AND PARTICIPANTS

We examined inpatients age ≥60 years with or without cancer and with gastrointestinal disorders.

METHODS

We used computed tomography (CT) image metrics in the 12th thoracic (T12), third lumbar (L3), erector spinae muscle (ESM), and psoas muscle (PM) regions to establish correlations with the 2019 Asian Working Group for Sarcopenia Consensus and used receiver operating characteristic area under the curve (AUC) to compare differences between metrics. Associations between CT metrics and mortality were reported as relative risk after adjustments.

RESULTS

We evaluated 385 patients (median age, 69.0 years; 60.8% men) and found consistent trends in cancer (49.6%) and noncancer (50.4%) cohorts. SMG had a stronger correlation with muscle mass than SMD [mean rho: 0.68 (range, 0.59‒0.73) vs 0.39 (range, 0.28‒0.48); all P < .01] in T12, L3, and PM regions and a stronger correlation with muscle function than SMI [mean rho: 0.60 (range, 0.50‒0.77) vs 0.36 (range, 0.22‒0.58); all P < .05] in T12, ESM, and L3 regions. SMG outperformed SMI in diagnostic accuracy in all regions, particularly for L3 (AUC: 0.87‒0.88 vs 0.80‒0.82; both P < .05). PMG (PM gauge) and L3SMG did not differ, whereas EMG (ESM gauge) or T12SMG and L3SMG did (AUC: 0.80‒0.82 vs 0.87‒0.88; all P < .05). L3SMI, L3SMD, T12SMG, EMG, and PMG showed no association with 1-year cancer-related mortality after adjusting for confounders; however, L3SMG [relative risk = 0.92 (0.85‒0.99); P = .023) was.

CONCLUSIONS AND IMPLICATIONS

L3SMG covers all features of sarcopenia with more diagnostic value than other metrics, allowing a complete sarcopenia assessment with CT alone and not just in populations with cancer.

Sarcopenia 'made simple' and outcomes from emergency laparotomy

BACKGROUND

Emergency Laparotomy (EL) is recognized as high-risk surgery with high mortality. Established surgical risk assessment tools (NELA Risk Prediction Calculator, P-POSSUM, ACS-NSQIP) are accurate predictors of morbidity and mortality. However, their multicomponent complexity limits their use in practice. Sarcopenia is associated with poorer surgical outcomes. This study tests for an association between a simple measure of radiological sarcopenia and mortality in EL patients in an Australian cohort.

METHODS

A retrospective analysis was conducted of 500 patients admitted to four Australian hospitals who underwent EL during 2016-2017. All patients had a contemporaneous abdomino-pelvic CT scan. Radiological sarcopenia was measured as the ratio of total psoas muscle area (PM) to L3 vertebral body cross sectional area (PM:L3). Patients were followed up to 12 months. Primary outcomes were 30-, 90- and 365-day mortality.

RESULTS

The mean 30-day mortality predictions for NELA, P-POSSUM and ACS-NSQIP were 11.36%, 17.28% and 11.30% respectively. PM:L3 ratio was associated with 30-, 90- and 365-day mortality (P < 0.001) and sex (P < 0.001) and negatively correlated with age (r = -0.4612; P < 0.001). Radiological sarcopenia had a weak negative correlation with NELA (r = -0.2737; P < 0.001), P-POSSUM (r = -0.1880; P < 0.001) and ACS-NSQIP (r = -0.2351; P < 0.001). The latter three metrics were significantly correlated (r > 0.5696; P < 0.001).

CONCLUSION

Radiological sarcopenia (CT-assessed PM:L3) is a significant predictor of mortality in EL patients in Australia. The results of this study suggest that radiological sarcopenia is equivalent to established risk assessment tools. The more timely and easily accessible CT-assessed PM:L3 metric is potentially automatable and may have significant utility in clinical practice.