Anatomical and CT approach of the adipose tissue: application in morbid obesity

Associations of Sarcopenia and Body Composition Measures With Mortality After Transcatheter Aortic Valve Replacement

BACKGROUND

Frailty associates with worse outcomes after transcatheter aortic valve replacement (TAVR). Sarcopenia underlies frailty, but the association between a comprehensive assessment of sarcopenia-muscle mass, strength, and performance-and outcomes after TAVR has not been examined.

METHODS

From a multicenter prospective registry of patients with symptomatic severe aortic stenosis undergoing TAVR, 445 who had a preprocedure computed tomography and clinical assessment of frailty were included. Cross-sectional muscle (psoas and paraspinal) areas were measured on computed tomography and indexed to height. Gait speed and handgrip strength were obtained, and patients were dichotomized into fast versus slow; strong versus weak; and normal versus low muscle mass. As measures of body composition, cross-sectional fat (subcutaneous and visceral) was measured and indexed to height.

RESULTS

The frequency of patients who were slow, weak, and had low muscle mass was 56%, 59%, and 42%, respectively. Among the 3 components of sarcopenia, only slower gait speed (muscle performance) was independently associated with increased post-TAVR mortality (adjusted hazard ratio, 1.12 per 0.1 m/s decrease [95% CI, 1.04-1.21]; P=0.004; adjusted hazard ratio, 1.38 per 1 SD decrease [95% CI, 1.11-1.72]; P=0.004). Meeting multiple sarcopenia criteria was not associated with higher mortality risk than fewer. Lower indexed visceral fat area (adjusted hazard ratio, 1.48 per 1 SD decrease [95% CI, 1.15-1.89]; P=0.002) was associated with mortality but indexed subcutaneous fat was not. Death occurred in 169 (38%) patients.

CONCLUSIONS

Among patients with symptomatic severe aortic stenosis and comprehensive sarcopenia and body composition phenotyping, gait speed was the only sarcopenia measure associated with post-TAVR mortality. Lower visceral fat was also associated with increased risk pointing to an obesity paradox also observed in other patient populations. These findings reinforce the clinical utility of gait speed as a measure of risk and a potential target for adjunctive interventions alongside TAVR to optimize clinical outcomes.

Computed Tomography Assessment of Fat Distribution and Staple-Line Leak Risk After Sleeve Gastrectomy

PURPOSE

Sleeve gastrectomy (SG) has become the most frequent bariatric procedure and staple-line leak represents its most feared complication. Visceral obesity, a core component of the metabolic syndrome, has been associated with worst postoperative outcomes after various abdominal surgical procedures, and can be estimated by computed tomography (CT). The aim of this study was to assess the impact of radiologically determined visceral obesity in the risk of staple-line leak after SG.

MATERIAL AND METHODS

A retrospective analysis of a prospective database was performed in consecutive patients undergoing SG. Several anthropometric variables were measured on a preoperative CT scan. Multivariate analysis was performed to determine preoperative risk factors for staple-line leak.

RESULTS

During the study period, 377 patients were included in the analysis. The median BMI was 39.7 kg/m² (36.5-43.5) and 8 patients (2.1%) presented a gastric leak. After multivariate analysis, visceral obesity defined by visceral fat area (VFA)/body surface area (BSA) ≥ 85 cm²/m² was the only independent predictive factor for gastric leak (OR = 5312).

CONCLUSION

CT scan-assessed visceral obesity defined by a VFA/BSA ratio ≥ 85 cm²/m² is associated with an increased risk of gastric leak after SG. Preoperatively radiological examination in patients suspected of visceral obesity would be useful to optimize preoperative management.

Surgical complications risk in obese and overweight recipients for kidney transplantation: a predictive morphometric model based on sarcopenia and vessel-to-skin distance

PURPOSE

Sarcopenia or adipose tissue distribution within obese and overweight renal transplanted have been poorly evaluated. Our objective was to evaluate morphometric markers to predict surgical complications in kidney transplantation.

METHODS

We retrospectively included patients with a BMI > 25 kg/m² undergoing kidney transplantation from 2012 to 2017. Following measurements were performed on CT-scan sections: Sub-cutaneous Adipose Tissue surface (SAT), Visceral Adipose Tissue surface (VAT), Vessel-to-Skin distance (VSK), Abdominal Perimeter (AP), and Psoas surface. A multivariable logistic regression model with BMI was compared to a model containing morphometric variables to determine the best predictive model for surgical complications.

RESULTS

248 patients were included, 15 (6%) experienced transplant nephrectomy, 18 (7.3%) urinary leakage, and 29 (11.7%) subcapsular renal hematoma. Multivariable logistic regression evidenced that sarcopenia and VSK were risk factors of surgical complication within a year post-transplantation (respectively, OR = 0.9, 95%CI (0.8-0.9), p = 0.04 and OR = 1.2, 95%CI (1.1-1.3), p = 0.002). Area under the curve for a predictive model including VSK, age and psoas surface was 0.69, whereas BMI model was 0.65.

CONCLUSION

Combined morphometric parameters of obesity were associated with surgical complications in kidney transplantation. Morphometric threshold may provide a more accurate and objective criteria than BMI to evaluate kidney transplantation outcomes. External validation is needed.

Temporary contraindication of obese recipients in kidney transplantation: A new morphometric tool for decision support

BACKGROUND

Morbid obesity, based on body mass index (BMI) and/or clinical examination, can be a temporary contraindication (TCI) of kidney transplantation. However, BMI alone does not evaluate the intra- or extra-peritoneal distribution of fatty tissue, and clinical examination alone is subjective. The objective was to evaluate the interest of morphometric criteria to ensure reproducible and consensual decision of TCI.

METHODS

We retrospectively included patients with a BMI >30 transplanted or temporarily contraindicated because of their weight from 2012 to 2017. The following measurements were performed on CT scan sections using a semiautomatic Hounsfield density detection software: subcutaneous adipose tissue surface (SAT), visceral adipose tissue surface (VAT), vessel-to-skin distance (VSK), abdominal perimeter (AP), and psoas index. Performance of morphometric measures to predict TCI was assessed through ROC analysis.

RESULTS

Ninety-seven patients were included: 76 kidney transplant recipients and 21 on the TCI list. The area under the curve (AUC, 95%CI) for the BMI model to predict TCI was 0.81 (0.72-0.90). A 5-variable model including BMI, VAT, VSK, AP, and age gave an AUC of 0.88 (0.78-0.98).

CONCLUSIONS

Morphometric obesity parameters are associated with TCI decision-making for kidney transplantation: When combined with BMI in a "morphometric tool," they were predictive of a TCI decision.