Psoas Muscle Area as a Prognostic Factor for Survival in Patients with an Asymptomatic Infrarenal Abdominal Aortic Aneurysm: A Retrospective Cohort Study

Psoas muscle analysis as a surrogate marker of sarcopenia and frailty: A multicenter analysis of predictive capacities over short- and long-term outcomes after abdominal aortic aneurysm repair

OBJECTIVES

Several predictive models exist for estimating the postoperative risks of abdominal aortic aneurysm (AAA) repair, although no particular tool has seen widespread use. We present the results of a multicenter, historic cohort study comparing the predictive capacity of the psoas muscle area (PMA), radiodensity (PMD), and lean muscle area (LMA) as surrogate markers of sarcopenia, over short- and long-term outcomes after AAA repair, compared to the mFI-5 and American Society of Anesthesiologists (ASA) scales.

METHODS

Retrospective review was conducted of all consecutive AAA elective repair cases (open or endovascular) in three tertiary-care centers from 2014 to 2019. Cross-sectional PMA, PMD, and LMA at the mid-body of the L3 vertebra were measured by two independent operators in the preoperative computed tomography. Receiver operating characteristic (ROC) curves were used to determine optimal cutoff values. Bivariate analysis, logistic regression, and Cox's proportional hazards models were built to examine the relationship between baseline variables and postoperative mortality, long-term mortality, and complications.

RESULTS

596 patients were included (mean age 72.7 ± 8 years, 95.1% male, 66.9% EVAR). Perioperative mortality was 2.3% (EVAR 1.2% vs open repair 4.6%, p = .015), and no independent predictors could be identified in the multivariate analysis. Conversely, an age over 74 years old (OR 1.84 95%CI 1.25-2.70), previous heart diseases (OR 1.62 95%CI 1.13-2.32), diabetes mellitus (OR 1.61 95%CI 1.13-2.32), and a PMD value over 66 HU (OR 0.58 95%CI 0.39-0.84) acted as independent predictors of long-term mortality in the Cox's proportional hazards model. Heart diseases (congestive heart failure or coronary artery disease), serum creatinine levels over 1.05 mg/dL, and an aneurysm diameter over 60 mm were independent predictors of major complications.

CONCLUSION

Surrogate markers of sarcopenia had a poor predictive profile for postoperative mortality after AAA repair in our sample. However, PMD stood out as an independent predictor of long-term mortality. This finding can guide future research and should be confirmed in larger datasets.

The Impact of Body Composition on Mortality and Hospital Length of Stay after Endovascular and Open Aortic Aneurysm Repair: A Retrospective Cohort Study

Background: Sarcopenia is an indicator of preoperative frailty and a patient-specific risk factor for poor prognosis in elderly surgical patients. Some studies have explored the prognostic significance of body composition parameters in relation to perioperative mortality after aortic repair and to mid- and long-term survival following endovascular aneurysm repair (EVAR). This study aimed to comprehensively investigate the effects of various body composition parameters, including but not limited to sarcopenia, on short- and long-term mortality as well as the length of hospital stay in two large cohorts of patients undergoing open surgical aortic repair (OSR) or EVAR. Methods: A single-institution retrospective cohort study included patients who underwent EVAR or OSR from January 2010 to December 2017. Several parameters of body composition on axial CT angiography images were analyzed, such as skeletal muscle area (SMA) with derived skeletal muscle index (SMI), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT). Results: 477 patients were included: 250 treated by OSR and 227 by EVAR; the mean age was 70.8 years (OSR) and 76.3 years (EVAR), with a mean follow-up of 54 months. Sarcopenia was associated with a prolonged length of hospital stay in EVAR patients but not in OSR patients (β coefficient 3.22; p-value 0.022 vs. β coefficient 0.391; p-value 0.696). Sarcopenia was an elevated one-year mortality risk post-EVAR compared to those without sarcopenia (p-value for the log-rank test 0.05). SMA and SMI were associated with long-term mortality in EVAR patients even after adjusting for multiple confounders (HR 0.98, p-value 0.003; HR 0.97, p-value 0.032). The analysis of the OSR cohort did not show a significant correlation between short- and long-term mortality and sarcopenia indicators. Conclusions: The results suggest that body composition could predict increased mortality and longer hospital stays in patients undergoing EVAR procedures. These findings were not confirmed in the cohort of patients who underwent OSR. Patients with sarcopenia and pre-operative malnutrition should be critically assessed to define the indication for treatment in this predominantly elderly and morbid cohort, despite EVAR procedures being less invasive. Body composition evaluation is an inexpensive and reproducible tool that can contribute to an improved decision-making process by identifying patients who will benefit most from EVAR, ensuring a more personalized and cost-effective treatment strategy. Further studies are planned to explore the added value of integrating body composition into a comprehensive risk stratification before aortic surgery.

The role of CT-assessed sarcopenia and visceral adipose tissue in predicting long-term survival in patients undergoing elective endovascular infrarenal aortic repair

OBJECTIVES

To evaluate if ileo-psoas muscle size and visceral adipose tissue (VAT) can predict long-term survival after endovascular aneurysm repair (EVAR).

METHODS

Patients who underwent EVAR between 2004 and 2012 in a single centre were included. Total psoas muscle area (TPA), abdominal VAT area, subcutaneous adipose tissue (SAT), and total adipose tissue were measured on the preoperative CT. Primary endpoint was all-cause mortality. Values are presented as median and interquartile range or absolute number and percentage. Cox regression analyses were performed to assess the associations with mortality.

RESULTS

Two hundred and eighty-four patients could be included in the study. During a median follow-up of 8 (4-11) years, 223 (79.9%) patients died. Age (P ≤ .001), cardiovascular (P = .041), cerebrovascular (P = .009), renal diseases (P = .002), and chronic obstructive pulmonary disease (P ≤ .001) were independently associated with mortality. TPA was associated with mortality in a univariate (P = .040), but not in a multivariate regression model (P = .764). No significant association was found between mortality and TPA index (P = .103) or any of the adiposity measurements with the exception of SAT (P = .040). However, SAT area loss in a multivariate analysis (P = .875).

CONCLUSIONS

Assessment of core muscle size and VAT did not contribute to improving the prediction of long-term survival after EVAR.

ADVANCES IN KNOWLEDGE

The finding of this study contradicts the previously claimed utility of core muscle size and VAT in predicting long-term survival after EVAR.

The Impact of Sarcopenia in the Long-Term Survival of Patients following Complex Endovascular Aortic Surgery for Thoracoabdominal Aortic Aneurysms

OBJECTIVES

Image-based sarcopenia has been the subject of recent studies, hypothesized as a prognostic factor for patients with thoracoabdominal aortic aneurysms.

METHODS AND MATERIALS

We conducted a single-center retrospective analysis of patients who underwent complex endovascular repair for thoracoabdominal aortic aneurysms between 2008 and 2016. CT image assessment was performed and patients were classified as sarcopenic and non-sarcopenic using two stratification methods: skeletal mass index (SMI) and total psoas muscle index (TPMI). According to sex, each patient was defined as sarcopenic if their SMI or TPMI was in the lowest third of the study group. The primary endpoint was impact of sarcopenia on perioperative mortality and long-term survival. Secondary endpoints were perioperative complications.

RESULTS

From a total of 155 patients, 135 were eligible for study. Overall, in-hospital mortality was 5.9% (8/135). The 30-day, 1-year, 3-year and 5-year mortality was 10.4% (14/135), 20% (27/135), 28.1% (38/135) and 31.1% (42/135), respectively. There was no difference in the long-term mortality rates between sarcopenic and non-sarcopenic patients regardless of the stratification method used (p = 0.4 for SMI and p = 0.2 for TPMI). According to SMI, 30-day mortality of sarcopenic patients was significantly lower in comparison to non-sarcopenic patients (1/45, 2.2% vs. 13/90, 14.4%, p = 0.028). Based on the total psoas muscle index, sarcopenic patients were at higher risk for development of pulmonary complications in comparison to non-sarcopenic patients postoperatively (p = 0.03).

CONCLUSION

Using SMI and TPMI, sarcopenia was not associated with reduced long-term survival in patients undergoing complex endovascular repair for thoracoabdominal aortic aneurysms.

Comparison Between Several CT-Derived Psoas Muscle Sarcopenia Markers for Predicting Survival After Abdominal Aortic Aneurysm Repair

BACKGROUND

Multiple CT-derived measurements of sarcopenia have been described yet their relationship with survival after abdominal aortic aneurysm (AAA) repair has not been properly assessed. We aimed to define and compare the relationship between several psoas CT-derived measurements and the 5-year survival after AAA repair and to evaluate their potential contribution to survival prediction.

METHODS

Preoperative CT area (TPA) and density (MTPD) of the psoas muscle at L3 were measured in 218 consecutive AAA patients electively intervened. Additional measurements were obtained by normalizing TPA by anthropometric data or L3-vertebra surface or by TPAxMTPD multiplication (lean psoas muscle area-LPMA). The association of sarcopenia markers with survival was evaluated with Cox models adjusted by age, sex, type of intervention and the Charlson Comorbidity Index, and their contribution to survival prediction assessed with the C-statistic and the Continuous Net Reclassification Index (c-NRI).

RESULTS

Sixty patients (27.5%) died during the first 5 years after surgery. There was a statistically significant and linear (spline analysis) relationship of sarcopenia markers with 5-year survival in all multivariate models, except that including LPMA. Despite this association, the inclusion of sarcopenia markers did not improve the C-statistic and moderately increased the c-NRI. None normalized sarcopenia markers performed better than TPA.

CONCLUSION

The majority of CT-derived psoas muscle measurements of sarcopenia showed a significant and independent relationship with survival after elective AAA repair. Despite this association, they did not appear to improve sufficiently our survival prediction ability to become an efficient tool for decision-making.

Effect of Body Mass Index on Early Outcomes of Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

This study compares the presentation, management, and outcomes of patients undergoing endovascular abdominal aortic aneurysm repair (EVAR), based on their weight status as defined by their body mass index (BMI).

METHODS

Patients with primary EVAR for ruptured and intact abdominal aortic aneurysm (AAA) were identified in the National Surgical Quality Improvement Program database (2016-2019). Patients were categorized by weight status (underweight: BMI < 18.5 kg/m², normal weight: 18.5-24.9 kg/m², overweight: 25-29.9 kg/m², Obese I: 30-34.9 kg/m², Obese II: 35-39.9 kg/m², Obese III: > 40 kg/m²). Preoperative characteristics and 30-day outcomes were compared.

RESULTS

Of 3,941 patients, 4.8% were underweight, 24.1% normal weight, 37.6% overweight, and 22.5% with Obese I, 7.8% Obese II, and 3.3% Obese III status. Underweight patients presented with larger (6.0 [5.4-7.2] cm) and more frequently ruptured (25.0%) aneurysms than normal weight patients (5.5 [5.1-6.2] cm and 4.3%, P < 0.001 for both). Pooled 30-day mortality was worse for underweight (8.5%) compared to all other weight status (1.1-3.0%, P < 0.001), but risk-adjusted analysis demonstrated that aneurysm rupture (odds ratio [OR] 15.9, 95% confidence interval [CI] 8.98-28.0) and not underweight status (OR 1.75, 95% CI 0.73-4.18) accounted for increased mortality in this population. Obese III status was associated with prolonged operative time and respiratory complications after ruptured AAA, but not 30-day mortality (OR 0.82, 95% CI 0.25-2.62).

CONCLUSIONS

Patients at either extreme of the BMI range had the worst outcomes after EVAR. Underweight patients represented only 4.8% of all EVARs, but 21% of mortalities, largely attributed to higher incidence of ruptured AAA at presentation. Severe obesity, on the other hand, was associated with prolonged operative time and respiratory complications after EVAR for ruptured AAA. BMI, as an independent factor, was however not predictive of mortality for EVAR.

Psoas Muscle Area as a Prognostic Factor for Survival in Patients Undergoing EVAR Conversion

OBJECTIVE

EVAR conversion(EVAR-c) is increasingly reported and known to be technically complex and physiologically demanding. It has been proposed that pragmatic anthropomorphic measures such as psoas muscle area(PMA) may reliably quantify levels of preoperative frailty and be used to inform point of care clinical decision making and patient discussions for a variety of complex operations. To date, there is mixed data supporting use of PMA as a prognostic factor in fenestrated endovascular and open AAA repairs; however, no literature exists evaluating the impact of preoperative PMA on EVAR-c results. Therefore, the purpose of this study was to review our EVAR-c experience and evaluate the association of PMA with perioperative and long-term mortality outcomes.

METHODS

A retrospective single-center review of all AAA repairs was performed(2002-2019) and EVAR-c procedures were subsequently analyzed(n=153). Cross-sectional PMA at the mid-body of the L3 vertebrae was measured. The lowest PMA tertile was used as a threshold value to designate patients as having "low" PMA(n=51) and this cohort was subsequently compared to subjects with "normal" PMA(n=102). Cox proportional hazards modeling was used to estimate covariate association with all-cause mortality.

RESULTS

Patients with low PMA were older(77 vs. 72 years;p=.002), more likely to be female(27% vs. 5%;p<.001), and had reduced BMI(26 vs. 29kg/m²;p=.002). Time to conversion, total number of EVAR reinterventions prior to conversion and elective EVAR-c presentation incidence were similar; however, patients with low PMA had larger aneurysms(8.3 vs. 7.5cm;p=.01) and increased post-EVAR sac growth(2.3 vs. 1cm;p=.005). Unadjusted inpatient mortality was significantly greater for low PMA patients(16% vs. normal PMA, 5%, p=.02). Similarly, the total number of complications was higher among low PMA subjects(1.5±1.9 vs. normal PMA, 0.9±1.5;p=.02). Although frequency of major adverse cardiovascular events and new onset inpatient hemodialysis were similar, low PMA patients had a more than four-fold increased likelihood of having persistent requirement of hemodialysis at discharge(18% vs. 4%,p=.01). The low PMA group had decreased survival at 1 and 5 years, respectively(77±5%, 65±6% vs. normal PMA, 86±3%, 82%±5%;log-rank p=.03). Low PMA was an independent predictor of mortality with every 100mm² increase in PMA being associated with a 15% reduction in mortality(HR 0.85,95% CI, .74-.97;p=.02).

CONCLUSION

Among EVAR-c patients, subjects with low preoperative PMA had higher rates of postoperative complications and worse overall survival. PMA assessments may be a useful adjunct to supplement traditional risk-stratification strategies when patients are being considered for EVAR-c.

The association of body composition with abdominal aortic aneurysm growth after endovascular aneurysm repair

Background

Body composition (BC) may be associated with abdominal aortic aneurysm (AAA) growth, but the results of previous research are contradictory. This study aimed to explore the relationship between BC and postoperative aneurysm progression.

Methods

Patients with regular postoperative follow-ups were retrospectively identified. The volume change of the aneurysm was measured to evaluate AAA progression. After segmenting different body components (subcutaneous fat, visceral fat, pure muscle, and intramuscular fat), the shape features and gray features of these tissues were extracted. Uni- and multivariable methods were used to analyze the relationship between imaging features of BC and AAA growth.

Results

A total of 94 patients (68 ± 8 years) were eligible for feature analyses. Patients with expansive aneurysms (29/94; volume change > 2%) were classified into Group(+) and others with stable or shrunken aneurysms (65/94) were classified into Group(−). Compared with Group(+), Group(−) showed a higher volume percent of pure muscle (21.85% vs 19.51%; p = .042) and a lower value of intramuscular fat (1.23% vs 1.65%; p = .025). CT attenuation of muscle tissues of Group(−) got a higher mean value (31.16 HU vs 23.92 HU; p = .019) and a lower standard deviation (36.12 vs 38.82; p = .006) than Group(+). For adipose tissue, we found no evidence of a difference between the two groups. The logistic regression model containing muscle imaging features showed better discriminative accuracy than traditional factors (84% vs 73%).

Conclusions

Muscle imaging features are associated with the volume change of postoperative aneurysms and can make an early prediction. Adipose tissue is not specifically related to AAA growth.

Radiographically Quantified Sarcopenia and Traditional Cardiovascular Risk Assessment in Predicting Long-term Mortality after EVAR

OBJECTIVE

This study evaluated radiographically quantified sarcopenia and patient's comorbidity burden based on traditional cardiovascular risk assessment as potential predictors of long-term mortality after endovascular aortic repair (EVAR).

METHODS

The study included 480 patients treated with standard EVAR for intact infrarenal abdominal aortic aneurysms. Patient characteristics, comorbidities, aneurysm dimensions and other preoperative risk factors were collected retrospectively. Preoperative computed tomography was used to measure psoas muscle area (PMA) at L3 level. Patients were divided into three groups based on ASA-score and PMA. In high-risk group, patients had sarcopenia (PMA <8.0 cm² for males and <5.5 cm² for females) and ASA score 4. In medium-risk group, patients had either sarcopenia or ASA 4. Patients in the low-risk group had no sarcopenia and ASA score was less than 4. Risk factors for long-term mortality were determined using multivariable analysis. Kaplan-Meier survival estimates were calculated for all-cause mortality.

RESULTS

Patients in the high- and medium risk-groups were older than in the low-risk group (77±7, 76±6 and 74±8 years, respectively, p<0.01). Patients in the high-risk group had higher prevalence of coronary artery disease, pulmonary disease and chronic kidney disease. There were no differences in 30-day or 90-day mortality between the groups. The independent predictors of long-term mortality were age, ASA-score, PMA, chronic kidney disease and maximum aneurysm sac diameter. The estimated one-year mortality rates were 5±2% for the low-risk, 5±2% for the medium-risk and 18±5% for the high-risk group (p<0.01). Five-year mortality estimates were 23±4%, 36±3% and 60±6%, respectively (p<0.01). The mean follow-up time was 5.0±2.8 years.

CONCLUSIONS

Both ASA and PMA were strong predictors of increased mortality after elective EVAR. The combination of these two can be used as a simple risk stratification tool to identify patients in whom aneurysm repair or the intensive long-term surveillance after EVAR may be unwarranted.

Current Clinical Implications of Frailty and Sarcopenia in Vascular Surgery: A Comprehensive Review of the Literature and Consideration of Perioperative Management

Frailty is a well-known geriatric syndrome of impaired physiological reserve and increased vulnerability to stressors. Sarcopenia is also used as a parameter of physical impairment characterized by muscle weakness. As population aging has become more prominent in recent years, both modalities are now regarded as clinically important prognostic tools defined by multidimensional factors that may affect clinical outcomes in various clinical settings. A preoperative surgical risk analysis is mandatory to predict clinical and surgical outcomes in all surgical practices, particularly in high-risk surgical patients. In vascular surgical settings, frailty and sarcopenia have been accepted as useful prognostic tools to evaluate patient characteristics before surgery, as these may predict perioperative clinical and surgical outcomes. Although minimally invasive surgical approaches, such as endovascular therapy, and hybrid approaches have been universally developed, achieving good vascular surgical outcomes for high-risk cohorts remains to be challenge due to the increasing prevalence of elderly patients and multiple preoperative co-morbidities in addition to frailty and sarcopenia. Therefore, to further improve clinical and surgical outcomes, these preoperative geriatric prognostic factors will be of great importance and interest in vascular surgical settings for both physicians and surgeons.

Central Sarcopenia, Frailty and Comorbidity as Predictor of Surgical Outcome in Elderly Patients with Degenerative Spine Disease

Objective

People are living longer and the elderly population continues to increase. The incidence of degenerative spinal diseases (DSDs) in the elderly population is quite high. Therefore, we are facing more cases of DSD and offering more surgical solutions in geriatric patients. Understanding the significance and association of frailty and central sarcopenia as risk factors for spinal surgery in elderly patients will be helpful in improving surgical outcomes. We conducted a retrospective cohort analysis of prospectively collected data to assess the impact of preoperative central sarcopenia, frailty, and comorbidity on surgical outcome in elderly patients with DSD.

Methods

We conducted a retrospective analysis of patients who underwent elective spinal surgery performed from January 1, 2019 to September 30, 2020 at our hospital. We included patients aged 65 and over who underwent surgery on the thoracic or lumbar spine and were diagnosed as DSD. Central sarcopenia was measured by the 50th percentile of psoas : L4 vertebral index (PLVI) using the cross-sectional area of the psoas muscle. We used the Korean version of the fatigue, resistance, ambulation, illnesses, and loss of weight (K-FRAIL) scale to measure frailty. Comorbidity was confirmed and scored using the Charlson Comorbidity Index (CCI). As a tool for measuring surgical outcome, we used the Clavien-Dindo (CD) classification for postoperative complications and the length of stay (LOS).

Results

This study included 85 patients (35 males and 50 females). The mean age was 74.05±6.47 years. Using the K-FRAIL scale, four patients were scored as robust, 44 patients were pre-frail and 37 patients were frail. The mean PLVI was 0.61±0.19. According to the CD classification, 50 patients were classified as grade 1, 19 as grade 2, and four as grade 4. The mean LOS was 12.35±8.17 days. Multivariate stepwise regression analysis showed that postoperative complication was significantly associated with surgical invasiveness and K-FRAIL scale. LOS was significantly associated with surgical invasiveness and CCI. K-FRAIL scale showed a significant correlation with CCI and PLVI.

Conclusion

The present study demonstrates that frailty, comorbidity, and surgical invasiveness are important risk factors for postoperative complications and LOS in elderly patients with DSD. Preoperative recognition of these factors may be useful for perioperative optimization, risk stratification, and patient counseling.

Preoperative sarcopenia and malnutrition are correlated with poor long-term survival after endovascular abdominal aortic aneurysm repair

PURPOSE

Sarcopenia and malnutrition are often used as surrogates for frailty, which is predictive of poor prognosis after surgery. We investigated the effects of sarcopenia and malnutrition on mortality after endovascular aneurysm repair (EVAR).

METHODS

The subjects of this study were patients who underwent EVAR at our hospital between June 2007 and December 2013, excluding those who underwent reintervention. The psoas muscle area at the L4 level was used as an indicator of sarcopenia. The Geriatric Nutritional Risk Index was used as an indicator of malnutrition.

RESULTS

There were 324 patients included in the study, with a mean age of 78.1 years and a median follow-up period of 56.7 months. Multivariate analysis revealed that sarcopenia (HR, 1.79; p = .042) and malnutrition (HR, 1.78; p = .043) were independent prognostic factors. Patients with both factors were classified as the high-risk group and others were classified as the low-risk group. The survival rate was significantly lower in the high-risk group than in the low-risk groups (p < .001). Even after propensity score matching, the high-risk group had a significantly lower survival rate (p < .001).

CONCLUSION

Both sarcopenia and malnutrition were associated with long-term mortality after EVAR. Patients with both indicators had a poor mid-term survival.

Impact of Sarcopenia on Acute Kidney Injury after Infrarenal Abdominal Aortic Aneurysm Surgery: A Propensity Matching Analysis

Background: Sarcopenia contributes to increased morbidity and mortality in patients undergoing surgery for abdominal aortic aneurysms (AAA). However, few reports have demonstrated whether sarcopenia would affect the development of postoperative acute kidney injury (AKI) in these patients. This study aimed to examine whether sarcopenia is associated with AKI and morbidity and mortality after infrarenal AAA operation. Methods: We retrospectively analysed 379 patients who underwent infrarenal AAA surgery. The diagnosis of sarcopenia was performed using the skeletal muscle index, which was calculated from axial computed tomography at the level of L3. The patients were separated into those with sarcopenia (n = 104) and those without sarcopenia (n = 275). We applied multivariable and Cox regression analyses to evaluate the risk factors for AKI and overall mortality. A propensity score matching (PSM) evaluation was done to assess the postoperative results. Results: The incidence of AKI was greater in sarcopenia than non-sarcopenia group before (34.6% vs. 15.3%; p < 0.001) and after the PSM analysis (34.6% vs. 15.4%; p = 0.002). Multivariable analysis revealed sarcopenia to be associated with AKI before (p = 0.010) and after PSM (p = 0.016). Sarcopenia was also associated with overall mortality before (p = 0.048) and after PSM (p = 0.032). A Kaplan–Meier analysis revealed that overall mortality was elevated patients with sarcopenia before and after PSM than in those without (log-rank test, p < 0.001, p = 0.022). Conclusions: Sarcopenia was associated with increased postoperative AKI incidence and overall mortality among individuals who underwent infrarenal AAA operation.

Sarcopenia as a Prognostic Factor in Peripheral Arterial Disease: Descriptive Review

BACKGROUND

Determine the influence of sarcopenia on the prognosis of peripheral arterial disease (PAD).

METHODS

A systematic search of the PubMed and Cochrane Library databases was performed with the keywords and medical subject heading (MesH): "muscle, skeletal", "sarcopenia", "prognosis", "duration of stay", "death", "mortality", "patient readmission", "length of stay", "peripheral arterial disease", "intermittent claudication" and "critical limb ischemia". Papers published from January 2010 to October 2020 in English, French, Spanish and Portuguese were eligible for inclusion. The primary outcome was overall survival. Secondary outcomes included post-operative complications, amputation, length of hospital stay and hospital readmission.

RESULTS

Of 1071 papers, 8 articles and 1511 patients were included (68.96% male, mean age 71.83 years). Five papers found an inverse relationship between SM area and mortality. Matsubara (2015) found that the 5-year overall survival rates were lower for patients with sarcopenia (23.5% ± 0.18% vs 77.5% ± 0.09% P = 0.001). Matsubara (2016) registered 3-year cardiovascular event-free survival rates of 43.1% and 91.2% for patients with and without sarcopenia (P < 0.01). Juszczak (2018) found that survival was lower in patients with reduced total psoas area. Taniguchi (2019) found that 3-year overall survival rate was 60% for patients with sarcopenia and 87% for patients without sarcopenia (P < 0.05). Shimazoe (2019) concluded sarcopenia was a significant predictor of overall survival. Distinctly, Nyers (2017) concluded that higher ratio bilateral psoas area to L4 vertebral body was associated with an increased risk of death. Two other studies analyzed other characteristics of the SM (density and strength). McDermott (2012) and found that lower calf muscle density and strength were associated with an increase in mortality. Sugai (2019) concluded that patients with major cardiovascular and limb events had a lower SM density.

CONCLUSIONS

Lower SM area and mass seem to be associated with a higher mortality in PAD patients.

Adverse Outcomes after Advanced EVAR in Patients with Sarcopaenia

PURPOSE

To determine whether low total psoas muscle area (tPMA), as a surrogate for sarcopaenia, is a predictor of adverse outcomes in patients undergoing advanced EVAR.

MATERIALS AND METHODS

A retrospective review of medical records was performed for 257 patients who underwent advanced EVAR (fenestrated or branched technique) in a single tertiary centre from 1 January 2008 to 1 September 2019. The study cohort was divided into tertiles based on tPMA measurement performed independently by two observers from a peri-procedural CT scan at the level of mid-L3 vertebral body. The low tertile was considered sarcopaenic. Logistic regression analysis was used to assess the association of tPMA with 30-day mortality and post-procedural complications. Univariable analysis and adjusted multivariable Cox regression were used to assess the association of tPMA with all-cause mortality.

RESULTS

A total of 257 patients comprised 193 males and 64 females with the mean age of 75.4 years (± 6.8) were included. Adjusted multivariable Cox regression revealed an 8% reduction in all-cause mortality for every 1 cm² increase in tPMA, P < 0.05. TPMA was associated with 30-day mortality (OR 0.85, 95% CI 0.75-0.96, P < 0.05) and spinal cord ischaemia (SCI) (OR 0.89, 95% CI 0.82-0.97, P < 0.05). For remaining post-procedural complications, tPMA was not a useful predictive tool. TPMA correlated negatively with hospital stay length (r_s-0.26, P < 0.001). Patients with lower tPMA were more likely to be discharged to a rehabilitation center (OR 0.93, 95% CI 0.87-0.98 , P < 0.05).

CONCLUSION

Measurement of tPMA can be a useful predictive tool for adverse outcomes after advanced EVAR.

LEVEL OF EVIDENCE

Level 3, Retrospective cohort study.

Impact of sarcopenia in aortoiliac occlusive disease in Mediterranean population

BACKGROUND

This study aims to validate the psoas muscle area and psoas muscle density as morphometric predictors in cardiovascular and cerebrovascular endpoints in patients with extensive aortoiliac peripheral arterial disease.

METHODS

A total of 57 patients (55 males, 2 females; mean age 60±8.2 years; range, 35 to 83 years) with Trans-Atlantic Inter-Society Consensus type D lesions who underwent revascularization at two Portuguese tertiary hospitals between January 2013 and July 2019 were retrospectively analyzed. The patients with a recent (<6 months) computed tomography scan prior to the revascularization procedure were included in the study. Both centers offered to their patients open and endovascular repair of aortoiliac peripheral arterial disease. Major adverse cardiovascular and cerebrovascular events and major adverse limb events were evaluated.

RESULTS

The median follow-up was 20 months. The mean survival rate was 93±3.4% at 30 days and 62.7±8.6% at 48 months. The discriminative thresholds found in this population were 2,175.8 mm2 for total psoas area and 51.75 Hounsfield unit for psoas muscle density. There was a statistically significant difference in the one-year survival rate (p=0.003 and p=0.291, respectively) and major adverse cardiovascular and cerebrovascular events (p=0.005 and p=0.206, respectively) for total psoas area compared to psoas muscle density.

CONCLUSION

Total psoas area shows a prognostic value for survival and major adverse cardiovascular and cerebrovascular events in this patient population.

Sarcopenia Aneurysm Scoring System Predicts Early and Midterm Mortality After Endovascular Repair for Abdominal Aortic Aneurysm

OBJECTIVE

The objective of the study was to develop a better model of prediction after EVAR using the psoas muscle index (PMI).

SUMMARY BACKGROUND DATA

The Glasgow Aneurysm Score (GAS), the modified Leiden Score (mLS), the Comorbidity Severity Score (CSS), and the Euro Score (ES) are known prognostic scoring after EVAR. Similarly, sarcopenia measured by PMI has been reported to be an important predictor. This study investigated a new scoring system using PMI predicting short and midterm overall mortality after EVAR.

METHODS

Three hundred ten patients were retrospectively evaluated. The primary endpoint was all-cause death. One hundred three patients were assigned to the derivation cohort and 207 patients to the validation cohort.

RESULTS

The all-cause mortality rates were 8.8% at 1 year, 23.5% at 3 years, and 32.8% at 5 years. In a multivariate analysis, age, aneurysm diameter, eGFR, and PMI were associated with all-cause mortality in the derivation cohort. The SAS system was defined as the sum of the following factors: elderly (75 years), large aneurysm (65 mm), low eGFR (30 mL/min/1.73 m), and low PMI (males: 48.2 cm/m, females: 36.8 cm/m). We compared the SAS with the other prognostic scoring for 5-year mortality evaluating the area under the receiver operating characteristic curves in the validation cohort (GAS: 0.731, mLS: 0. 718, CSS: 0. 646, ES: 0.661, and SAS: 0.785, P = 0.013).

CONCLUSION

We developed the SAS to predict all-cause mortality after elective EVAR and this scoring showed excellent predictive performance.

Psoas muscle area and attenuation are highly predictive of complications and mortality after complex endovascular aortic repair

OBJECTIVE

The present study evaluated the psoas muscle area and attenuation (radiodensity), quantified by computed tomography, together with clinical risk assessment, as predictors of outcomes after fenestrated and branched endovascular aortic repair (FBEVAR).

METHODS

The present single-center study included 504 patients who had undergone elective FBEVAR for pararenal or thoracoabdominal aortic aneurysms. The clinical risk assessment included age, sex, comorbidities, body mass index, glomerular filtration rate, aneurysm size and extent, cardiac stress test results, ejection fraction, and American Society of Anesthesiologists (ASA) score. Preoperative computed tomography was used to measure the psoas muscle area and attenuation at the L3 level. The lean psoas muscle area (LPMA; area in cm² multiplied by attenuation in Hounsfield units [HU]) was calculated by multiplying the area by the attenuation. The risk factors for 90-day mortality, major adverse events (MAEs), and long-term mortality were determined using multivariable analysis. MAEs included 30-day or in-hospital death, acute kidney injury, myocardial infarction, respiratory failure, paraplegia, stroke, and bowel ischemia. A novel risk stratification method was proposed according to the strongest predictors of mortality and MAEs on multivariable analysis.

RESULTS

The 30-day mortality, 90-day mortality, and MAE rates were 2.0%, 5.6%, and 20%, respectively. The independent predictors of 90-day mortality were chronic obstructive pulmonary disease, chronic kidney disease, ASA score, and LPMA. The independent predictors of MAEs were aneurysm diameter, glomerular filtration rate, and LPMA. For long-term mortality, the independent predictors were chronic kidney disease, congestive heart failure, extent I-III thoracoabdominal aortic aneurysms, ASA score, and LPMA. The patients were stratified into three groups according to the ASA score and LPMA: low risk, ASA score II or LPMA >350 cm²HU (n = 290); medium risk, ASA score III and LPMA ≤350 cm²HU (n = 181); and high risk, ASA score IV and LPMA ≤350 cm²HU (n = 33). The 90-day mortality and MAE rates were 1.7% and 16% in the low-, 7.2% and 24% in the medium-, and 30% and 33% in the high-risk patients, respectively (P < .001 and P = .02, respectively). Patients with ASA score IV and LPMA <200 cm²HU, indicating sarcopenia (n = 14) had a 43% risk of death within 90 days. The 3-year survival estimates were 80% ± 3% for the low-, 70% ± 4% for the medium-, and 35% ± 9% for the high-risk patients (P < .001). The mean follow-up time was 3.1 ± 2.3 years.

CONCLUSIONS

LPMA was a strong predictor of outcomes and the only independent predictor of both mortality and MAEs after FBEVAR. A high muscle mass was protective against complications, regardless of the ASA score. Risk stratification based on the ASA score and LPMA can be used to identify patients at excessively high operative risk.

Impact of Total Psoas Area and Lean Muscular Area on Mortality after Endovascular Aortic Aneurysm Repair

BACKGROUND

Sarcopenia has assumed growing relevance as a morbimortality predictor after major abdominal surgery. The aim of this study is to access total psoas muscle area (TPA) and lean muscle area (LMA) impact in morbimortality after elective endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

Asymptomatic patients submitted to aortic endoprosthesis implantation between January 1, 2014 and December 31, 2018 at our vascular surgery department were retrospectively evaluated. After exclusion criteria were applied, 105 patients were included in the study; preoperative computed tomography scans were evaluated using OSIRIX software (Bernex, Switzerland). Two observers independently calculated TPA at the most caudal level of the L3 vertebra and respective density, therefore calculating LMA. Patients were separated by tertiles with the lowest being considered sarcopenic and with higher muscle steatosis and compared with the higher tertiles. Patient demographics and intraoperative and postoperative period variables were collected. Charlson comorbidity index was calculated and surgical complications classified according to Clavien-Dindo. The intraclass correlation coefficient and Bland-Altman plot were made to characterize interobserver variability. Survival analysis was performed with the Kaplan-Meier method, and differences between survival curves were tested with the log-rank test. The effect of sarcopenia on patient survival was assessed using Cox proportional hazard models.

RESULTS

Considering TPA, univariate analyses revealed that patients in the lower tertile had inferior survival (P = 0.03), whereas multivariate analyses showed increased likelihood of mortality (P = 0.039, hazard ratio (HR) 3.829). For LMA, univariate analyses revealed that patients in the lower tertile had inferior survival (P = 0.013), whereas multivariate analyses showed increased likelihood of mortality (P = 0.026, HR 4.153). When analyzing patients in the lowest tertile of both TPA and LMA, both univariate (P = 0.002) and multivariate (P = 0.018, HR 4.166) analyses reveled inferior survival.

CONCLUSIONS

Our study reveals reduced survival in patients with low TPA and low LMA submitted to elective EVAR; these factors should probably be taken into consideration in the future for preoperative risk evaluation and surgical planning.

Frailty Factors and Outcomes in Vascular Surgery Patients: A Systematic Review and Meta-analysis

OBJECTIVE

To describe and critique tools used to assess frailty in vascular surgery patients, and investigate its associations with patient factors and outcomes.

BACKGROUND

Increasing evidence shows negative impacts of frailty on outcomes in surgical patients, but little investigation of its associations with patient factors has been undertaken.

METHODS

Systematic review and meta-analysis of studies reporting frailty in vascular surgery patients (PROSPERO registration: CRD42018116253) searching Medline, Embase, CINAHL, PsycINFO, and Scopus. Quality of studies was assessed using Newcastle-Ottawa scores (NOS) and quality of evidence using Grading of Recommendations Assessment, Development, and Evaluation criteria. Associations of frailty with patient factors were investigated by difference in means (MD) or expressed as risk ratios (RRs), and associations with outcomes expressed as odds ratios (ORs) or hazard ratios (HRs). Data were pooled using random-effects models.

RESULTS

Fifty-three studies were included in the review and only 8 (15%) were both good quality (NOS ≥ 7) and used a well-validated frailty measure. Eighteen studies (62,976 patients) provided data for the meta-analysis. Frailty was associated with increased age [MD 4.05 years; 95% confidence interval (CI) 3.35, 4.75], female sex (RR 1.32; 95% CI 1.14, 1.54), and lower body mass index (MD -1.81; 95% CI -2.94, -0.68). Frailty was associated with 30-day mortality [adjusted OR (AOR) 2.77; 95% CI 2.01-3.81), postoperative complications (AOR 2.16; 95% CI 1.55, 3.02), and long-term mortality (HR 1.85; 95% CI 1.31, 2.62). Sarcopenia was not associated with any outcomes.

CONCLUSION

Frailty, but not sarcopenia, is associated with worse outcomes in vascular surgery patients. Well-validated frailty assessment tools should be preferred clinically, and in future research.

Sonographic muscle mass assessment in patients after cardiac surgery

BACKGROUND

Patients undergoing cardiac surgery particularly those with comorbidities and frailty, experience frequently higher rates of post-operative morbidity, mortality and prolonged hospital length of stay. Muscle mass wasting seems to play important role in prolonged mechanical ventilation (MV) and consequently in intensive care unit (ICU) and hospital stay.

AIM

To investigate the clinical value of skeletal muscle mass assessed by ultrasound early after cardiac surgery in terms of duration of MV and ICU length of stay.

METHODS

In this observational study, we enrolled consecutively all patients, following their admission in the Cardiac Surgery ICU within 24 h of cardiac surgery. Bedside ultrasound scans, for the assessment of quadriceps muscle thickness, were performed at baseline and every 48 h for seven days or until ICU discharge. Muscle strength was also evaluated in parallel, using the Medical Research Council (MRC) scale.

RESULTS

Of the total 221 patients enrolled, ultrasound scans and muscle strength assessment were finally performed in 165 patients (patients excluded if ICU stay < 24 h). The muscle thickness of rectus femoris (RF), was slightly decreased by 2.2% [(95% confidence interval (CI): - 0.21 to 0.15), n = 9; P = 0.729] and the combined muscle thickness of the vastus intermedius (VI) and RF decreased by 3.5% [(95%CI: - 0.4 to 0.22), n = 9; P = 0.530]. Patients whose combined VI and RF muscle thickness was below the recorded median values (2.5 cm) on day 1 (n = 80), stayed longer in the ICU (47 ± 74 h vs 28 ± 45 h, P = 0.02) and remained mechanically ventilated more (17 ± 9 h vs 14 ± 9 h, P = 0.05). Moreover, patients with MRC score ≤ 48 on day 3 (n = 7), required prolonged MV support compared to patients with MRC score ≥ 49 (n = 33), (44 ± 14 h vs 19 ± 9 h, P = 0.006) and had a longer duration of extracorporeal circulation was (159 ± 91 min vs 112 ± 71 min, P = 0.025).

CONCLUSION

Skeletal quadriceps muscle thickness assessed by ultrasound shows a trend to a decrease in patients after cardiac surgery post-ICU admission and is associated with prolonged duration of MV and ICU length of stay.

Role of Frailty and Comorbidity Status in Predicting Morbidity and Mortality in Patients with Acute Mesenteric Ischemia

BACKGROUND

This study was performed to determine the association of frailty and comorbidity status with postoperative morbidity and mortality in patients with acute mesenteric ischemia (AMI).

METHODS

Patients diagnosed with AMI between April 2006 and September 2019 were enrolled in this study. Frailty was evaluated by sarcopenia which was diagnosed by third lumbar vertebra psoas muscle area (PMA). Comorbidity status was evaluated by the Charlson Comorbidity Index (CCI) score. Univariate and multivariate analyses evaluating the risk factors for postoperative morbidity and mortality were performed.

RESULTS

Of the 174 patients, 86 were managed conservatively and 88 underwent surgery. In surgically managed patients, 39.8% developed complications within 30 days of surgery. Ten patients died within 30 days of the operation. In the univariate analyses, white blood cell >10 g/L, low PMA, CCI score ≥2, and bowel resection were associated with postoperative complications. Multivariate analysis revealed that low PMA, CCI score ≥2, and bowel resection were independent predictors of postoperative complications.

CONCLUSIONS

This study demonstrated that low PMA, CCI score ≥2, and bowel resection were independent risk factors for postoperative complications in patients with AMI. Preoperative assessment of frailty using PMA and the evaluation of comorbidity status using CCI may serve as helpful tools in preoperative risk assessment and should be integrated into scoring systems for surgically treated AMI.

Sarcopenia assessed by the quantity and quality of skeletal muscle is a prognostic factor for patients undergoing cardiac surgery

PURPOSE

Sarcopenia was assessed as a prognostic factor for patients undergoing cardiac surgery by evaluating the quantity and quality of skeletal muscle.

METHODS

Sarcopenia was assessed by perioperative abdominal computed tomography using the total psoas muscle index (TPI) and intra-muscular adipose tissue content (IMAC). Patients were classified into high- (HT, n = 143) and low- (LT, n = 63) TPI groups and low- (LI, n = 122) and high- (HI, n = 84) IMAC groups.

RESULTS

There were significantly more complications in the LT and HI groups than in the HT and LI groups. (HT 15.4% vs. LT 30.2%, P = 0.014) (LI 11.5% vs. HI 31.1%, P < 0.001). There were more respiratory complications in the LT group (HT 0% vs. LT 6.3%, P = 0.002) and more surgical site infections in the HI group than in the LI group (LI 0.8% vs. HI 7.1%, P = 0.014). A multivariable analysis showed that low TPI and high IMAC significantly predicted more major complications than other combinations (odds ratio [OR] 2.375; 95% confidence interval [CI] 1.152-5.783; P = 0.036, OR 3.973; 95% CI 1.737-9.088; P = 0.001).

CONCLUSIONS

Sarcopenia is a risk factor for complications. The quantity and quality of muscle must be assessed to predict operative outcomes.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000027077.

Stent-graft surface movement after endovascular aneurysm repair: baseline parameters for prediction, and association with migration and stent-graft-related endoleaks

OBJECTIVES

To evaluate the influence of baseline parameters on the occurrence of stent-graft surface movement after endovascular aneurysm repair (EVAR) and to investigate its association with migration and stent-graft-related endoleaks (srEL).

METHODS

In this retrospective, cross-sectional study, three-dimensional surface models of the stent-graft, delimited by landmarks using custom-built software, were derived from the pre-discharge and last follow-up computed tomography angiography (CTA). Stent-graft surface movement in the proximal anchoring zone between these examinations was considered significant at a threshold of 9 mm. The Cox proportional hazards model was used to determine baseline variables associated with the occurrence of stent-graft surface movement. The association between migration and srEL with stent-graft surface movement was tested with the chi-square and the Fisher exact test, respectively.

RESULTS

Stent-graft surface movement was observed in 54 (28.9%) of 187 patients. Multivariate analysis revealed that age ([HR] 1.05; p = 0.017), proximal neck diameter ([HR] 5.07; p < 0.001), infrarenal aortic neck angulation ([HR] 1.02, p = 0.002), and proximal neck length ([HR] 0.62, p < 0.001) were significantly associated with the occurrence of stent-graft surface movement. Migration and srEL occurred in 17 (31.5%) and 5 (9.3%) patients, with and 11 (8.3%) and 2 (1.5%) without stent-graft surface movement (p < 0.001, p = 0.022).

CONCLUSIONS

Age, neck diameter, infrarenal neck angulation, and proximal neck length were significantly associated with the occurrence of stent-graft surface movement. Apart from possible use of adjunctive sealing systems, concerned patients may benefit from regular CTA surveillance, enabling timely diagnosis of subtle changes of stent-graft position.

KEY POINTS

• Stent-graft surface movement, demonstrating subtle, three-dimensional changes in stent-graft position in the proximal anchoring zone, can be derived from CTA examinations. • Age, proximal neck diameter, and infrarenal neck angulation were significantly associated with an increased incidence of stent-graft surface movement. Stent-graft surface movement is significantly more frequent in patients with stent-graft migration and stent-graft-related endoleaks. • Consideration of risk factors for stent-graft surface movement may help to identify patients who might benefit from regular CTA surveillance and timely diagnosis of subtle changes of stent-graft position, enabling re-interventions to prevent migration and srEL.

Application of Baseline Clinical and Morphological Parameters for Prediction of Late Stent Graft Related Endoleaks after Endovascular Repair of Abdominal Aortic Aneurysm

OBJECTIVES

To evaluate the influence of baseline clinical and morphological parameters on the occurrence of a late stent graft related endoleak (srEL; types 1 and 3) after endovascular aneurysm repair (EVAR).

METHODS

This is a retrospective case control study of patients who were routinely followed up after EVAR of abdominal aortic aneurysms. Pre-interventional, pre-discharge, and last available multislice computed tomography angiogram (MSCTA) of 279 patients were analysed. Stent graft related endoleaks detected by follow up MSCTA at least six months after EVAR were specified as late srEL. Baseline demographic characteristics and morphological variables were derived from the pre-interventional and pre-discharge MSCTA. Univariable and multivariable analysis with a Cox proportional hazards model were used to determine baseline factors associated with the occurrence of a late srEL.

RESULTS

Twenty-four (8.6%) of 279 patients suffered a late srEL, during a mean MSCTA follow up of 30.9 ± 25.8 (23.5, IQR 10.6-42.8) months. In the univariable analysis, age (hazard ratio [HR] 1.09; p = .001), female sex (HR 3.25; p = .014), right iliac sealing diameter (HR 10.04; p = .03), left iliac sealing diameter (HR 8.65; p = .001), infrarenal aortic neck angulation (HR 1.02; p = .011), and suprarenal fixation level (HR 3.47; p = .014) were significantly associated with an increased incidence of late srEL. Age (HR 1.08; p = .012), female sex (HR 2.72; p = .049), and left iliac sealing diameter (HR 4.48; p = .033) proved to be risk factors significantly associated with a higher incidence of late srEL in multivariable analysis.

CONCLUSIONS

Older patients, those with female gender, and those with larger left iliac sealing diameters seem to experience higher rates of late srEL. Independent confirmation of these must be addressed in larger studies.

Should endovascular approach be considered as the first option for thoraco-abdominal aortic aneurysms?

Open surgical repair has been the gold standard for treatment of thoracoabdominal aortic aneurysms (TAAAs). The technique of open TAAA repair has evolved from the use of "island" patch incorporation to separate branch vessel bypass, from "clamp and go" to routine use of distal perfusion, and towards more extensive repair in patients with connective tissue disorders. Open TAAA repair can be done with excellent results in highly specialized centers. However, these operations continue to carry excessive risk when performed outside large aortic centers, with 30-day mortality estimated on 20% according to statewide and national databases. In octogenarians, the mortality of elective open TAAA repair can be up to 40%. Endovascular repair was introduced as an alternative to open surgical repair in the elderly or higher risk patients using hybrid reconstruction, parallel grafts or fenestrated and branched endografts. Several large aortic centers have developed dedicated clinical programs to advance techniques of fenestrated-branched endovascular repair using patient-specific and off-the-shelf devices, offering a minimally invasive alternative to open repair allowing treatment of increasingly older and sicker TAAA patients. During the last decade, improvements in device design, patient selection, spinal cord injury protocols, and perioperative management have contributed to a continued decline in morbidity and mortality of fenestrated-branched endovascular aortic repair, challenging open surgical repair as the new "gold standard" for treatment of TAAAs. Despite the improved results, endovascular repair is a highly technical procedure that requires vast experience, involves a significant risk of complications, and also, has an impact on patients' physical quality of life. In this article, we review the current technical aspects of endovascular TAAA repair with the main focus on the evidence of open versus endovascular outcomes of TAAA repair.

Influence of psoas muscle area on mortality following elective abdominal aortic aneurysm repair

BACKGROUND

The effect of sarcopenia based on the total psoas muscle area (TPMA) on CT is inconclusive in patients undergoing abdominal aortic aneurysm (AAA) intervention. The aim of this prospective cohort study was to evaluate morphometric sarcopenia as a method of risk stratification in patients undergoing elective AAA intervention.

METHODS

TPMA was measured on preintervention CT images of patients undergoing elective endovascular aneurysm repair (EVAR) or open aneurysm repair. Mortality was assessed in relation to preintervention TPMA using Cox regression analysis, with calculation of hazard ratios at 30 days, 1 year and 4 years. Postintervention morbidity was evaluated in terms of postintervention care, duration of hospital stay and 30-day readmission. Changes in TPMA on surveillance EVAR imaging were also evaluated.

RESULTS

In total, 382 patient images acquired between March 2008 and December 2016 were analysed. There were no significant intraobserver and interobserver differences in measurements of TPMA. Preintervention TPMA failed to predict morbidity and mortality at all time points. The mean(s.d.) interval between preintervention and surveillance imaging was 361·3(111·2) days. A significant reduction in TPMA was observed in men on surveillance imaging after EVAR (mean reduction 0·63(1·43) cm2 per m2 ; P < 0·001). However, this was not associated with mortality (adjusted hazard ratio 1·00, 95 per cent c.i. 0·99 to 1·01; P = 0·935).

CONCLUSION

TPMA is not a suitable risk stratification tool for patients undergoing effective intervention for AAA.

CoreSlicer: a web toolkit for analytic morphomics

BACKGROUND

Analytic morphomics, or more simply, "morphomics," refers to the measurement of specific biomarkers of body composition from medical imaging, most commonly computed tomography (CT) images. An emerging body of literature supports the use of morphomic markers measured on single-slice CT images for risk prediction in a range of clinical populations. However, uptake by healthcare providers been limited due to the lack of clinician-friendly software to facilitate measurements. The objectives of this study were to describe the interface and functionality of CoreSlicer- a free and open-source web-based interface aiming to facilitate measurement of analytic morphomics by clinicians - and to validate muscle and fat measurements performed in CoreSlicer against reference software.

RESULTS

Measurements of muscle and fat obtained in CoreSlicer show high agreement with established reference software. CoreSlicer features a full set of DICOM viewing tools and extensible plugin interface to facilitate rapid prototyping and validation of new morphomic markers by researchers. We present published studies illustrating the use of CoreSlicer by clinicians with no prior knowledge of medical image segmentation techniques and no formal training in radiology, where CoreSlicer was successfully used to predict operative risk in three distinct populations of cardiovascular patients.

CONCLUSIONS

CoreSlicer enables extraction of morphomic markers from CT images by non-technically skilled clinicians. Measurements were reproducible and accurate in relation to reference software.