Imperial College London

Professor Thanos Athanasiou MD PhD MBA FECTS FRCS

Faculty of MedicineDepartment of Surgery & Cancer

Professor of Cardiovascular Sciences
 
 
 
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Contact

 

t.athanasiou

 
 
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Location

 

1022Queen Elizabeth the Queen Mother Wing (QEQM)St Mary's Campus

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Summary

 

Publications

Publication Type
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701 results found

Fergadi MP, Magouliotis DE, Vlychou M, Rountas C, Athanasiou T, Zacharoulis Det al., 2021, A meta-analysis evaluating contrast-enhanced intraoperative ultrasound (CE-IOUS) in the context of surgery for colorectal liver metastases., Abdom Radiol (NY), Vol: 46, Pages: 4178-4188

BACKGROUND: This study aimed to assess the outcomes of contrast-enhanced intraoperative ultrasound (CE-IOUS) for patients with colorectal liver metastases (CRLMs) undergoing surgery. METHOD: A thorough literature search was performed in PubMed, Scopus, and Cochrane databases, in accordance with the PRISMA guidelines. The Odds Ratio, Weighted Mean Difference, and 95% Confidence Interval were evaluated, by means of Random-Effects model. RESULTS: Eleven articles met the inclusion criteria and incorporated 497 patients. The present study shows that CE-IOUS is associated with higher sensitivity and accuracy compared with multidetector computed tomography (MDCT), magnetic resonance imaging (MRI), and intraoperative ultrasound (IOUS) in identifying CRLMs (p < 0.05). The positive predictive value was similar among the different modalities. Furthermore, new CRLMs were identified by CE-IOUS, thus affecting the surgical plan in 128 patients (51.8% of the patients with new CRLMs). Moreover, 91 patients (71%) underwent a more extensive hepatectomy and 15 patients (11.7%) were considered non-operable. Two alternative contrast agents, Sonazoid and Sonovue, were employed with similar sensitivity (p > 0.05). CONCLUSION: These outcomes suggest the superiority of the CE-IOUS over MDCT, MRI, and IOUS for the staging of patients with CRLMs undergoing surgery. However, they should be treated with caution given the small number of the included studies.

Journal article

Salmasi MY, Ravishankar R, Abdullahi Y, Hartley P, Kyriazis PG, Athanasiou T, Punjabi Pet al., 2021, Predictors of outcome after CABG in the South-Asian community: a propensity matched analysis, PERFUSION-UK, ISSN: 0267-6591

Journal article

Whittaker G, Salmasi MY, Aydin A, Magouliotis D, Raja SG, Asimakopoulos G, Moorjani N, Athanasiou Tet al., 2021, Recommendations for the use of coronary and valve simulators in cardiac surgical training: a systematic review., Eur J Cardiothorac Surg

OBJECTIVES: The aim of this study was to systematically review the simulators that are currently available for coronary artery bypass graft and valve surgery and, in addition, to review the validation evidence supporting them and to recommend several simulators for training based on the analysis of results. METHODS: A systematic literature search of the MEDLINE® (1946 to May 2021) and EMBASE® (1947 to May 2021) databases was performed to identify simulators for coronary artery and valvular procedures in cardiothoracic surgery. A selection of keywords and MeSH terms was used to execute the literature search. After identification of relevant articles, data were extracted and analysed. RESULTS: Thirty-seven simulators were found in 31 articles. Simulators were found for coronary artery bypass graft (n = 24) and valve surgery (n = 13). The majority of models were either benchtop (n = 28) or hybrid (n = 8) modalities. Evidence of validity was demonstrated in 15 (40.5%) simulators. Twenty-two (59.5%) simulators had no validation evidence, and 1 (2.7%) simulator had 3 or more elements of validity established. CONCLUSIONS: Two simulators were recommended for supplemental training in cardiothoracic surgery. Low-fidelity models can provide a broad foundation for surgical skills' development whereas high-fidelity simulators can be used for immersive training scenarios and appraisals. These should be utilized in early training, at which point the learning curve of trainees is steepest.

Journal article

Magouliotis DE, Fergadi MP, Christodoulidis G, Svokos AA, Svokos KA, Bareka M, Athanasiou Tet al., 2021, In-depth bioinformatic study of the cadherin 5 interactome in patients with thoracic aortic aneurysm unveils 8 novel biomarkers., Eur J Cardiothorac Surg

OBJECTIVES: Thoracic aortic aneurysm (TAA) is characterized by the dilation of the aorta and is associated with poor prognosis if not diagnosed and treated early. In this context, the identification of biomarkers regarding the TAA diagnosis, monitoring and prognosis is crucial. The purpose of the current study was to investigate the differential gene expression profile of the cadherin 5 (CDH5 or VE-Cadherin) gene network in patients with TAA, to propose novel biomarkers. METHODS: In silico techniques were used to construct the interactome of the CDH5 network, identify the differentially expressed genes (DEGs) in TAA as compared to healthy controls, and uncover the related molecular functions and the regulating miRNAs. RESULTS: Transcriptomic data of one microarray dataset were included, incorporating 43 TAA and 43 control samples. Eight DEGs were identified; 7 were up-regulated and 1 was down-regulated. A molecular signature of 8 genes (CDH5; Calcitonin Receptor-Like Receptor-CALCRL; Activin A Receptor-Like Type 1-ACVRL1, Tryptophanyl-TRNA Synthetase 1-WARS; Junction Plakoglobin-JUP, Protein Tyrosine Phosphatase Receptor Type J-PTPRJ, Purinergic Receptor P2X 4-P2RX4, Kinase Insert Domain Receptor-KDR) were identified as biomarkers associated with TAA. PTPRJ was associated with excellent discrimination and calibration in predicting TAA presentation. Positive correlations were reported regarding the expression of CDH5-CALCRL, CDH5-ACVRL1, CDH5-WARS and CDH5-PTPRJ. Finally, gene set enrichment analysis indicated the molecular functions and miRNA families (hsa-miR-296-5p, hsa-miR-6836-5p, hsa-miR-6132, hsa-miR-27a-5p and hsa-miR-6773-5p) relevant to the 8 biomarkers. CONCLUSIONS: These outcomes propose an 8-gene molecular panel associated with TAA.

Journal article

Pring ET, Malietzis G, Kendall SWH, Jenkins JT, Athanasiou Tet al., 2021, Crisis management for surgical teams and their leaders, lessons from the COVID-19 pandemic; A structured approach to developing resilience or natural organisational responses, INTERNATIONAL JOURNAL OF SURGERY, Vol: 91, ISSN: 1743-9191

Journal article

Drami I, Pring ET, Gould L, Malietzis G, Naghibi M, Athanasiou T, Glynne-Jones R, Jenkins JTet al., 2021, Body Composition and Dose-limiting Toxicity in Colorectal Cancer Chemotherapy Treatment; a Systematic Review of the Literature. Could Muscle Mass be the New Body Surface Area in Chemotherapy Dosing?, Clin Oncol (R Coll Radiol)

Chemotherapy dosing is traditionally based on body surface area calculations; however, these calculations ignore separate tissue compartments, such as the lean body mass (LBM), which is considered a big pool of drug distribution. In our era, colorectal cancer patients undergo a plethora of computed tomography scans as part of their diagnosis, staging and monitoring, which could easily be used for body composition analysis and LBM calculation, allowing for personalised chemotherapy dosing. This systematic review aims to evaluate the effect of muscle mass on dose-limiting toxicity (DLT), among different chemotherapy regimens used in colorectal cancer patients. This review was carried out according to the PRISMA guidelines. MEDLINE and EMBASE databases were searched from 1946 to August 2019. The primary search terms were 'sarcopenia', 'myopenia', 'chemotherapy toxicity', 'chemotherapy dosing', 'dose limiting toxicity', 'colorectal cancer', 'primary colorectal cancer' and 'metastatic colorectal cancer'. Outcomes of interest were - DLT and chemotoxicity related to body composition, and chemotherapy dosing on LBM. In total, 363 studies were identified, with 10 studies fulfilling the selection criteria. Seven studies were retrospective and three were prospective. Most studies used the same body composition analysis software but the chemotherapy regimens used varied. Due to marked study heterogeneity, quantitative data synthesis was not possible. Two studies described a toxicity cut-off value for 5-fluorouracil and one for oxaliplatin based on LBM. The rest of the studies showed an association between different body composition metrics and DLTs. Prospective studies are required with a larger colorectal cancer cohort, longitudinal monitoring of body composition changes during treatment, similar body composition analysis techniques, agreed cut-off values and standardised chemotherapy regimens. Incorporation of body composition analysis in the clinical setting will allow early

Journal article

Salmasi MY, Pirola S, Mahuttanatan S, Fisichella SM, Sengupta S, Jarral OA, Oo A, O'Regan D, Xu XY, Athanasiou Tet al., 2021, Geometry and flow in ascending aortic aneurysms are influenced by left ventricular outflow tract orientation: Detecting increased wall shear stress on the outer curve of proximal aortic aneurysms., J Thorac Cardiovasc Surg

BACKGROUND: The geometrical characterization of ascending thoracic aortic aneurysms in clinical practice is limited to diameter measurements. Despite growing interest in hemodynamic assessment, its relationship with ascending thoracic aortic aneurysm pathogenesis is poorly understood. This study examines the relationship between geometry of the ventriculo-aortic junction and blood flow patterns in ascending thoracic aortic aneurysm disease. METHODS: Thirty-three patients with ascending thoracic aortic aneurysms (exclusions: bicuspid aortic valves, connective tissue disease) underwent 4-dimensional flow magnetic resonance imaging. After image segmentation, geometrical parameters were measured, including aortic curvature, tortuosity, length, and diameter. A unique angular measurement made by the trajectory of the left ventricular outflow tract axis and the proximal aorta was also conducted. Velocity profiles were quantitatively and qualitatively analyzed. In addition, 11 patients (33%) underwent wall shear stress mapping of the ascending thoracic aortic aneurysm region using computational fluid dynamics simulation. RESULTS: Greater left ventricular outflow tract aortic angles were associated with larger aortic diameters at the levels of the sinus (coefficient = 0.387, P = .014) and ascending aorta (coefficient = 0.284, P = .031). Patients with left ventricular outflow tract aortic angles greater than 60° had marked asymmetric flow acceleration on the outer curvature in the proximal aorta, ascertained from 4-dimensional flow analysis. For patients undergoing computational fluid dynamics assessment, regression analysis found that higher left ventricular outflow tract aortic angles were associated with significantly higher wall shear stress values in the outer curve of the aorta (coefficient 0.07, 95% confidence interval 0.04-0.11, P = .002): Angles greater than 50° yielded time-averaged wall shear stress values g

Journal article

Li J, 2021, Roux-en-Y Gastric bypass-induced bacterial perturbation contributes to altered host-bacterial co-metabolic phenotype, Microbiome, Vol: 9, ISSN: 2049-2618

BACKGROUND: Bariatric surgery, used to achieve effective weight loss in individuals with severe obesity, modifies the gut microbiota and systemic metabolism in both humans and animal models. The aim of the current study was to understand better the metabolic functions of the altered gut microbiome by conducting deep phenotyping of bariatric surgery patients and bacterial culturing to investigate causality of the metabolic observations. METHODS: Three bariatric cohorts (n = 84, n = 14 and n = 9) with patients who had undergone Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG) or laparoscopic gastric banding (LGB), respectively, were enrolled. Metabolic and 16S rRNA bacterial profiles were compared between pre- and post-surgery. Faeces from RYGB patients and bacterial isolates were cultured to experimentally associate the observed metabolic changes in biofluids with the altered gut microbiome. RESULTS: Compared to SG and LGB, RYGB induced the greatest weight loss and most profound metabolic and bacterial changes. RYGB patients showed increased aromatic amino acids-based host-bacterial co-metabolism, resulting in increased urinary excretion of 4-hydroxyphenylacetate, phenylacetylglutamine, 4-cresyl sulphate and indoxyl sulphate, and increased faecal excretion of tyramine and phenylacetate. Bacterial degradation of choline was increased as evidenced by altered urinary trimethylamine-N-oxide and dimethylamine excretion and faecal concentrations of dimethylamine. RYGB patients' bacteria had a greater capacity to produce tyramine from tyrosine, phenylalanine to phenylacetate and tryptophan to indole and tryptamine, compared to the microbiota from non-surgery, normal weight individuals. 3-Hydroxydicarboxylic acid metabolism and urinary excretion of primary bile acids, serum BCAAs and dimethyl sulfone were also perturbed following bariatric surgery. CONCLUSION: Altered bacterial composition and metabolism contribute to metabolic observations in biofluid

Journal article

Moscarelli M, Lorusso R, Abdullahi Y, Varone E, Marotta M, Solinas M, Casula R, Parlanti A, Speziale G, Fattouch K, Athanasiou Tet al., 2021, The Effect of Minimally Invasive Surgery and Sternotomy on Physical Activity and Quality of Life., Heart Lung Circ, Vol: 30, Pages: 882-887

AIM: The aim of this study was to compare minimally invasive surgery (MI) and median sternotomy (MS) in terms of post-procedure health-related quality of life (HRQoL) and functional outcome. METHOD: We conducted a multicentre prospective cohort study that enrolled patients from January 2015 until February 2017. Combined cardiac procedures were performed with MS and isolated valve procedures with either MS or MI, depending on patient preference and surgeon experience. HRQoL was measured using the five-level version of the EQ-5D (EQ-5D-5L) and physical activity before and after surgery was evaluated using a wearable accelerometer. Activity patterns and intensity recorded by the accelerometer in each period were classified as "sedentary", "light physical activity", "moderate physical activity", and "vigorous physical activity" for each patient. We also conducted a sub-analysis of frail patients in each group, as identified by the Reported Edmonton Frail Scale (>10 points). Patients were followed for 1 year. RESULTS: The study included 100 consecutive patients who underwent MI (n=50) or MS (n=50) during the study period. Patients in the MI group showed a faster recovery of physical activity in the immediate postoperative period and superior HRQoL in the first 3 months (both p<0.001) versus the MS group. Differences between the MI and MS group were indistinguishable over a longer follow-up. A similar correlation was observed in the frailty subanalysis. Overall, the MS group had a higher cumulative incidence of events than the MI group (p<0.001). CONCLUSIONS: Compared to conventional MS, MI was associated with better HRQoL and early functional outcome, even in frail patients.

Journal article

Moscarelli M, Santarpino G, Athanasiou T, Mastroroberto P, Fattouch K, Nasso G, Speziale Get al., 2021, A pooled analysis of pacemaker implantation after Perceval sutureless aortic valve replacement., Interact Cardiovasc Thorac Surg

 : OBJECTIVES: We performed a literature meta-analysis to estimate the rate of pacemaker implantation after Perceval sutureless aortic valve replacement. METHODS: Pertinent articles were identified from the PubMed, Google Scholar, Ovid MEDLINE and Ovid EMBASE databases. Eligible studies reported the de novo incidence of postoperative pacemaker implantation after Perceval valve surgery. Among 394 articles retrieved, 26 studies including 9492 patients met the inclusion criteria. RESULTS: The pooled event rate for postoperative pacemaker implantation was 7% [95% confidence interval (CI) 6-9%]; however, significant heterogeneity was observed across studies. In a sub-analysis, there was no difference between the rates of pacemaker implantation calculated from multicentre and registry studies (8 studies, 6845 patients; 7%, 95% CI 5-10%) and single-centre studies (18 studies, 2647 patients; 7%, 95% CI 5-9%; P = 0.75). Implantation rates were similar in high-volume studies (16 studies, 9121 patients; 7%, 95% CI 5-8%) than in low-volume studies (10 studies, 371 patients; pooled rate: 7%, 95% CI 4-14%; P = 0.5). Postoperative pacemaker implantation rates tended to decrease over time. CONCLUSIONS: With a pooled event rate of 7%, postoperative pacemaker implantation remains an important limitation of Perceval sutureless valve surgery, although we observed a degree of variability across included studies. The resultant findings provide a useful estimate for physicians and patients and can serve as a benchmark for future comparative studies. PROSPERO REGISTRATION NUMBER: CRD42020188397.

Journal article

Moscarelli M, Di Bari N, Nasso G, Fattouch K, Athanasiou T, Bonifazi R, Speziale Get al., 2021, Early safety performance of a modified technique of aorta replacement with sinotubular stabilization., Asian Cardiovasc Thorac Ann

BACKGROUND: We sought to determine if a modified technique for ascending aorta replacement with sinotubular junction reduction and stabilization was safe. METHODS: This technique was performed by suspension of the three commissures, invagination of the aortic Dacron graft and advancing the graft into the ventricles. We included patients with dilatation of the ascending aorta, normal sinuses of Valsalva dimension (<45 mm), with or without aortic annulus enlargement (>25 mm) and with various degree of aortic insufficiency (from grade 1 to 3). RESULTS: From April to October 2019, 20 patients were recruited from two centers; mean age was 66.9 ± 12.8 years, 13 were male; grade 1, 2 and 3 was present in 12, 2 and 6 patients, respectively. All patients underwent ascending aorta replacement with modified technique; an additional open subvalvular ring was used in 8 patients with aortic insufficiency ≥ 2; cusps repair was performed in 6 patients (5 plicating central stitches/1 shaving); concomitant coronary artery bypass grafting was performed in 10 patients. There was no 30-day mortality. One patient was re-explored for bleeding. All patients completed six-month follow-up; at the transthoracic echocardiography, there was no aortic insufficiency ≥ 1 except one patient with aortic insufficiency grade 1 who underwent ascending aorta replacement and subvalvular ring; no patients underwent reintervention. CONCLUSIONS: This modified technique for ascending aorta replacement and sinotubular junction stabilization was safe. It could be associated with other aortic valve sparing techniques. However, such remodeling approach has to be validated in a larger cohort of patients with longer follow-up.

Journal article

Arjomandi Rad A, Naruka V, Vardanyan R, Viviano A, Salmasi MY, Magouliotis D, Kendall S, Casula R, Athanasiou Tet al., 2021, Mitral and tricuspid annuloplasty ring dehiscence: a systematic review with pooled analysis., Eur J Cardiothorac Surg

OBJECTIVES: Mitral and tricuspid ring annuloplasty dehiscence with consequent recurrent valve regurgitation is a rare but challenging procedural failure. The incidence and predisposing risk factors for annuloplasty ring dehiscence include technical and pathological ones. METHODS: A systematic database search with pooled analysis was conducted of original articles that only included dehiscence rate of mitral and tricuspid ring in EMBASE, MEDLINE, Cochrane database and Google Scholar, from inception to November 2020. The outcomes included were dehiscence rate in mitral and tricuspid, type of ring implanted, dehiscence rate by pathology and by ring size and shape. RESULTS: Our search yielded 821 relevant studies. Thirty-three studies met the inclusion criteria with a total of 10 340 patients (6543 mitral, 1414 tricuspid) of which 87 (mitral) and 30 (tricuspid) had dehiscence. Overall, dehiscence rate was 1.43%, diagnosed at a median of 4.5 ± 1.0 months postoperatively. A significant difference in mitral dehiscence rate was found by ring type (semi-rigid 1.86%, rigid 2.32%; flexible 0.43%; P < 0.001). There was no significant difference in rate of dehiscence by ring size (P = 0.067) and shape in mitral (P = 0.281) but there was higher dehiscence rate in ischaemic compared to non-ischaemic mitral regurgitation (3.91% vs 1.63%; P = 0.022). Among tricuspid studies, 9 of 10 studies did not report any dehiscence. CONCLUSIONS: Although rigid, semi-rigid and flexible annuloplasty rings provide acceptable valve repair outcomes, mitral annuloplasty ring dehiscence is clinically more common among rigid rings. Understanding the multifactorial nature of ring dehiscence will help in identifying the patients at high risk and improve their clinical outcomes.

Journal article

Manchester E, Pirola S, Salmasi M, O'Regan D, Athanasiou T, Xu Xet al., 2021, Analysis of turbulence effects in a patient-specific aorta with aortic valve stenosis, Cardiovascular Engineering and Technology, Vol: 12, Pages: 438-453, ISSN: 1869-408X

Blood flow in the aorta is often assumed laminar, however aortic valve pathologies may induce transition to turbulence and our understanding of turbulence effects is incomplete. The aim of the study was to provide a detailed analysis of turbulence effects in aortic valve stenosis (AVS).Methods:Large-eddy simulation (LES) of flow through a patient-specific aorta with AVS was conducted. Magnetic resonance imaging (MRI) was performed and used for geometric reconstruction and patient-specific boundary conditions. Computed velocity field was compared with 4D flow MRI to check qualitative and quantitative consistency. The effect of turbulence was evaluated in terms of fluctuating kinetic energy, turbulence-related wall shear stress (WSS) and energy loss.Results:Our analysis suggested that turbulence was induced by a combination of a high velocity jet impinging on the arterial wall and a dilated ascending aorta which provided sufficient space for turbulence to develop. Turbulent WSS contributed to 40% of the total WSS in the ascending aorta and 38% in the entire aorta. Viscous and turbulent irreversible energy losses accounted for 3.9 and 2.7% of the total stroke work, respectively.Conclusions:This study demonstrates the importance of turbulence in assessing aortic haemodynamics in a patient with AVS. Neglecting the turbulent contribution to WSS could potentially result in a significant underestimation of the total WSS. Further work is warranted to extend the analysis to more AVS cases and patients with other aortic valve diseases.

Journal article

Garas G, Darzi A, Athanasiou T, Lancaster Jet al., 2021, Stapler closure versus manual closure in total laryngectomy for laryngeal cancer: A systematic review and meta-analysis, CLINICAL OTOLARYNGOLOGY, Vol: 46, Pages: 918-918, ISSN: 1749-4478

Journal article

Salmasi MY, Jarral OA, Athanasiou T, 2021, What can we learn from outliers in cardiac surgery?, JOURNAL OF CARDIAC SURGERY, Vol: 36, Pages: 1832-1834, ISSN: 0886-0440

Journal article

Arhi C, Askari A, Nachiappan S, Bottle A, Arebi N, Athanasiou T, Ziprin P, Aylin P, Faiz Oet al., 2021, Stage at Diagnosis and Survival of Colorectal Cancer With or Without Underlying Inflammatory Bowel Disease: A Population-based Study, JOURNAL OF CROHNS & COLITIS, Vol: 15, Pages: 375-382, ISSN: 1873-9946

Journal article

Khader AA, Allaf M, Lu OW, Lazopoulos G, Moscarelli M, Kendall S, Salmasi MY, Athanasiou Tet al., 2021, Does the clinical effectiveness of Mitraclip compare with surgical repair for mitral regurgitation?, Journal of Cardiac Surgery, Vol: 36, Pages: 1103-1119, ISSN: 0886-0440

Background:Surgical repair of the mitral valve has long been the established therapy for degenerative mitral regurgitation (MR). Newer transcatheter methods over the last decade, such as the MitraClip, serve to restore mitral function with reduced procedural burden and enhanced recovery. This study aims to compare the shortterm and midterm outcomes of MitraClip insertion with surgical repair for MR.Methods:A systematic review of the literature was conducted for studies comparing outcomes between surgical repair and MitraClip. The initial search returned 1850 titles, from which 12 studies satisfied the inclusion criteria (one randomized controlled trial and 11 retrospective studies).Results:The final analysis comprised 4219 patients (MitraClip 1210; surgery 3009).Operative mortality was not different between the groups (odds ratio [OR] = 1.63, 95% confidence interval [CI]: [0.63−4.23]; p = .317). Length of hospital stay was significantly shorter in the MitraClip group (standardized mean difference [SMD] = 0.882, 95% CI: [0.77–0.99]; p < .001) with considerable heterogeneity (I2 > 90%; p < .001).The rate of reoperation on the mitral valve was lower in the surgical group (OR = 0.392; 95% CI: [0.188−0.817]; p = .012) as was the rate of MR recurrence grade moderate or above (OR = 0.29; 95% CI: [0.19−0.46]; p < .001) during midterm follow up. Long term survival (4–5 years) was also similar between both groups (hazard ratio = 0.70; 95% CI: [0.35−1.41]; p = .323).Conclusions:This study highlights the superior midterm durability of surgical valve repair for MR compared with the MitraClip.

Journal article

Abdullahi YS, Salmasi MY, Moscarelli M, Parlanti A, Marotta M, Varone E, Solinas M, Sheriff RM, Casula RP, Athanasiou Tet al., 2021, The Use of Frailty Scoring to Predict Early Physical Activity Levels After Cardiac Surgery., Ann Thorac Surg, Vol: 111, Pages: 36-43

BACKGROUND: Assessing patient fitness prior to high-risk operations is becoming increasingly vital in cardiothoracic surgery. Physical activity (PA) and frailty measures are powerful perioperative tools, albeit underused in clinical practice. This study aimed to assess the influence of patient frailty on PA postsurgery and other short-term outcomes. METHODS: Eighty patients undergoing a variety of cardiac surgical procedures (coronary revascularisation, valve repair/replacement, or combination) were recruited to participate. The Reported Edmonton Frailty Scale was used to measure preoperative frailty. As objective measures of PA, participants wore a wrist accelerometer device for 14 days prior to their operation and early in the postoperative period for 30 days. RESULTS: A global reduction in PA was observed in the early postoperative period. Frailty was a significant predictor of reduced light (coefficient -2.23, 95% CI -4.21 to -0.25, P = .028) and moderate activity (coefficient -1.85, 95% CI -2.99 to -0.70, P = .002) postoperatively. Neither frailty nor preoperative PA were predictors of postoperative composite complications. Both frailty (coefficient 0.134, 95% CI 0.106-0.162, P < .001) and PA scores (P < .05) were strong predictors of length of hospital stay (coefficient 1.76, 95% CI 0.003-3.524, P = .05). Furthermore, patients who stayed in hospital longer were more likely to suffer early postoperative complications (stroke, renal failure, reoperation, pacemaker) if they were frail (P < .0001) compared to non-frail patients (P = .607). CONCLUSIONS: This study highlights the predictive ability of objective frailty scoring and PA measurement for outcomes after cardiac surgery. This has important implications for surgical risk stratification and personalized postoperative planning.

Journal article

Olchanyi MD, Sadikov A, Frattolin J, Sasidharan S, Salmasi MY, Edgar LT, Jarral O, Athanasiou T, Moore JEet al., 2020, Validation of markerless strain-field optical tracking approach for soft tissue mechanical assessment., Journal of Biomechanics, Vol: 116, Pages: 1-11, ISSN: 0021-9290

Strain measurement during tissue deformation is crucial to elucidate relationships between mechanical loading and functional changes in biological tissues. When combined with specified loading conditions, assessment of strain fields can be used to craft models that accurately represent the mechanical behavior of soft tissue. Inhomogeneities in strain fields may be indicative of normal or pathological inhomogeneities in mechanical properties. In this study, we present the validation of a modified Demons registration algorithm for non-contact, marker-less strain measurement of tissue undergoing uniaxial loading. We validate the algorithm on a synthetic dataset composed of artificial deformation fields applied to a speckle image, as well as images of aortic sections of varying perceptual quality. Initial results indicate that Demons outperforms recent Optical Flow and Digital Image Correlation methods in terms of accuracy and robustness to low image quality, with similar runtimes. Demons achieves at least 8% lower maximal deviation from ground truth on 50% biaxial and shear strain applied to aortic images. To illustrate utility, we quantified strain fields of multiple human aortic specimens undergoing uniaxial tensile testing, noting the formation of strain concentrations in areas of rupture. The modified Demons algorithm captured a large range of strains (up to 50%) and provided spatially resolved strain fields that could be useful in the assessment of soft tissue pathologies.

Journal article

Al-Balah A, Naqvi D, Houbby N, Chien L, Sen S, Athanasiou T, Salmasi MYet al., 2020, Comparison of outcomes following transfemoral versus trans-subclavian approach for transcatheter aortic valve Implantation: a meta-analysis, International Journal of Cardiology: Heart and Vasculature, Vol: 31, ISSN: 2352-9067

BackgroundThe subclavian artery is an alternative access route for transcatheter aortic valve implantation (TAVI), with a potential advantage in patients unsuitable for traditional access routes such as the femoral artery. This study aimed to determine the safety and efficacy of the trans-subclavian (TSc) compared to the trans-femoral (TF) approach.MethodsA systematic review was conducted on two online databases: Embase and Medline. The initial search returned 508 titles. Nine observational studies were included: n = 2938 patients (2382 TF and 556 TSc).ResultsBoth TSc and TF groups were comparable for: 30-day mortality (Odds ratio, OR 0.75, 95% CI 0.49 – 1.16, p = 0.195); in-hospital stroke (OR 1.05, 95% CI 0.60–1.85, p = 0.859); myocardial infarction (OR 1.97, 95% CI 0.74–5.23, p = 0.176); paravalvular leaks (OR 1.20, 95% CI 0.76–1.90, p = 0.439); rates of postoperative permanent pacemaker implantation (OR 1.49, 95% CI 0.92–2.41, p = 0.105); in-hospital bleeding and meta-analysis demonstrated no significant difference between access points (OR 3.44, 95% CI 0.35–34.22, p = 0.292). Procedural time was found to be longer in the TSc group (SMD 1.02; 95% CI 0.815–1.219, p < 0.001). Major vascular complications were significantly higher in the TF group (OR 0.55, 95% CI 0.32–0.94, p = 0.029). Meta regression found no influence of the covariates on the outcomes.ConclusionSubclavian access is both a safe and feasible alternative access route for TAVI with lower risks of major vascular complications. This study supports the use of subclavian access as a viable alternative in patient groups where transfemoral TAVI is contraindicated.

Journal article

Salmasi M, Jarral OA, Pirola S, Sasidharan S, Pepper J, Oo A, Moore J, Xu XY, Athanasiou Tet al., 2020, In-vivo blood flow parameters can predict at-risk aortic aneurysms and dissection: a comprehensive biomechanics model, EUROPEAN HEART JOURNAL, Vol: 41, Pages: 2339-2339, ISSN: 0195-668X

Journal article

Sideris M, Emin EI, Hanrahan JG, Odejinmi F, Mallick R, Nicolaides M, Velmahos G, Athanasiou T, Papalois V, Papalois Aet al., 2020, ABC of Surgical Teaching: Time to Consider a Global Blueprint for Holistic Education, JOURNAL OF INVESTIGATIVE SURGERY, ISSN: 0894-1939

Journal article

Salmasi MY, Panda A, Hartley P, Abdulkhader A, Osman A, Nienaber C, Athanasiou T, Asimakopoulos Get al., 2020, Aortic root replacement to treat type A aortic dissection: A comparison of midterm outcomes between composite valve grafts and porcine aortic roots., Journal of Cardiac Surgery, Vol: 35, Pages: 1840-1847, ISSN: 0886-0440

BACKGROUND: Porcine aortic roots (PAR) have been reported in the literature with acceptable short- and long-term outcomes for the treatment of aortic root aneurysms. However, their efficacy in type A aortic dissection (TAAD) is yet to be defined. METHODS: Using data from a locally collated aortic dissection registry, we compared the outcomes in patients undergoing aortic root replacement for TAAD using either of two surgical options: (a) PAR or (b) composite valve grafts (CVG). A retrospective analysis was conducted for all procedures in the period from 2005 to 2018. RESULTS: A total of 252 patients underwent procedures for TAAD in the time period. Sixty-five patients had aortic root replacements (PAR n = 30, CVG n = 35). Between-group comparisons identified a younger CVG group (50.5 vs 64.5, P < .05) although all other covariates were comparable. Operative parameters were comparable between the two groups. The use of PAR did not significantly impact operative mortality (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.22-3.61; P = .992), stroke (OR, 2.91, 0.25-34.09, P = .395), reoperation (OR, 0.91; 95% CI, 0.22-3.62; P = .882) or length of stay (coeff 2.33, -8.23 to 12.90; P = .659) compared to CVG. Five-year survival was similar between both groups (PAR 59% vs CVG 69%; P = .153) and reoperation was negligible. Echocardiography revealed significantly lower aortic valve gradients in the PAR group (8.69 vs 15.45mm Hg; P < .0001), and smaller left ventricular dimensions both at 6-week and 1-year follow-up (P < .05). CONCLUSIONS: This study highlights the comparable short- and midterm outcomes of PAR in cases of TAAD, in comparison to established therapy.

Journal article

Naase H, Harling L, Kidher E, Sepehripour A, Nguyen B, Kapelouzou A, Cokkinos D, Angelini G, Evans P, Athanasiou Tet al., 2020, Toll-like receptor 9 and the inflammatory response to surgical trauma and cardiopulmonary bypass, Journal of Cardiothoracic Surgery, Vol: 15, ISSN: 1749-8090

ObjectivesCardiac surgery can lead to post-operative end-organ complications secondary to activation of systemic inflammatory response. We hypothesize that surgical trauma or cardiopulmonary bypass (CPB) may initiate systemic inflammatory response via release of mitochondrial DNA (mtDNA) signaling Toll-like receptor 9 (TLR9) and interleukin-6 production (IL-6).Materials and methodsThe role of TLR9 in systemic inflammatory response in cardiac surgery was studied using a murine model of sternotomy and a porcine model of sternotomy and CPB. mtDNA and IL-6 were measured with and without TLR9-antagonist treatment. To study ischemia-reperfusion injury, we utilized an ex-vivo porcine kidney model.ResultsIn the rodent model (n = 15), circulating mtDNA increased 19-fold (19.29 ± 3.31, p < 0.001) and plasma IL-6 levels increased 59-fold (59.06 ± 14.98) at 1-min post-sternotomy compared to pre-sternotomy. In the murine model (n = 11), administration of TLR-9 antagonists lowered IL-6 expression post-sternotomy when compared to controls (59.06 ± 14.98 vs. 5.25 ± 1.08) indicating that TLR-9 is a positive regulator of IL-6 after sternotomy. Using porcine models (n = 10), a significant increase in circulating mtDNA was observed after CPB (Fold change 29.9 ± 4.8, p = 0.005) and along with IL-6 following renal ischaemia-reperfusion. Addition of the antioxidant sulforaphane reduced circulating mtDNA when compared to controls (FC 7.36 ± 0.61 vs. 32.0 ± 4.17 at 60 min post-CPB).ConclusionCPB, surgical trauma and ischemic perfusion injury trigger the release of circulating mtDNA that activates TLR-9, in turn stimulating a release of IL-6. Therefore, TLR-9 antagonists may attenuate this response and may provide a future therapeutic target whereby the systemic inflam

Journal article

Slim N, Harraz A, Kheirabadi AN, Salamsi Y, Markides C, Athanasiou T, Casula Ret al., 2020, Innovating a Novel Brain Protection Device for Use in Cardiac Surgery and Cardiac Arrest: A Cool Solution Using Diffusion-Absorption-Refrigeration Technology, International Surgical Conference of the Association-of-Surgeons-in-Training, Publisher: WILEY, Pages: 38-38, ISSN: 0007-1323

Conference paper

Salmasi MY, Al-Saadi N, Hartley P, Jarral OA, Raja S, Hussein M, Redhead J, Rosendahl U, Nienaber CA, Pepper JR, Oo AY, Athanasiou Tet al., 2020, The risk of misdiagnosis in acute thoracic aortic dissection: a review of current guidelines, HEART, Vol: 106, Pages: 885-891, ISSN: 1355-6037

Journal article

Askari A, Guillen LS, Millan M, Nachiappan S, Bottle A, Athanasiou T, Faiz Oet al., 2020, Colorectal tumour characteristics and oncological outcome in patients with inflammatory bowel disease, SURGICAL PRACTICE, Vol: 24, Pages: 60-68, ISSN: 1744-1625

Journal article

Garas G, Cingolani I, Patel V, Panzarasa P, Alderson D, Darzi A, Athanasiou Tet al., 2020, Surgical innovation in the era of global surgery: a network analysis, Annals of Surgery, Vol: 271, Pages: 868-874, ISSN: 0003-4932

OBJECTIVE: To present a novel network-based framework for the study of collaboration in surgery and demonstrate how this can be used in practice to help build and nurture collaborations that foster innovation. BACKGROUND: Surgical innovation is a social process that originates from complex interactions among diverse participants. This has led to the emergence of numerous surgical collaboration networks. What is still needed is a rigorous investigation of these networks and of the relative benefits of various collaboration structures for research and innovation. METHODS: Network analysis of the real-world innovation network in robotic surgery. Hierarchical mixed-effect models were estimated to assess associations between network measures, research impact and innovation, controlling for the geographical diversity of collaborators, institutional categories, and whether collaborators belonged to industry or academia. RESULTS: The network comprised of 1700 organizations and 6000 links. The ability to reach many others along few steps in the network (closeness centrality), forging a geographically diverse international profile (network entropy), and collaboration with industry were all shown to be positively associated with research impact and innovation. Closed structures (clustering coefficient), in which collaborators also collaborate with each other, were found to have a negative association with innovation (P < 0.05 for all associations). CONCLUSIONS: In the era of global surgery and increasing complexity of surgical innovation, this study highlights the importance of establishing open networks spanning geographical boundaries. Network analysis offers a valuable framework for assisting surgeons in their efforts to forge and sustain collaborations with the highest potential of maximizing innovation and patient care.

Journal article

Moscarelli M, Fattouch K, Gaudino M, Nasso G, Paparella D, Punjabi P, Athanasiou T, Benedetto U, Angelini GD, Santarpino G, Speziale Get al., 2020, Minimal Access Versus Sternotomy for Complex Mitral Valve Repair: A Meta-Analysis, ANNALS OF THORACIC SURGERY, Vol: 109, Pages: 737-744, ISSN: 0003-4975

Journal article

Sideris M, Papalois V, Athanasiou T, Papagrigoriadis S, Pierides M, Velmahos G, Papalois Aet al., 2020, A Novel Multi-faceted Course Blueprint to Support Outcome-based Holistic Surgical Education: The Integrated Generation 4 Model (iG4), IN VIVO, Vol: 34, Pages: 503-509, ISSN: 0258-851X

Journal article

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