Jean-Philippe Verhoye

Pre- and postoperative tricuspid regurgitation in patients with severe symptomatic aortic stenosis: importance of pre-operative tricuspid annulus diameter

Aims Secondary tricuspid regurgitation (STR) is commonly found in patients with aortic stenosis and is associated with increased morbidity. The study sought to evaluate the prevalence of pre-operative STR and its progression after surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI). Also, it sought to analyse the predictors of post-operative changes in STR. Methods and results We prospectively evaluated 116 patients (aged 75.1 ± 9.8 years, predominantly male) who undergo SAVR or TAVI for severe aortic stenosis (AS) from September 2013 to April 2015. Patients with associated valve disease requiring intervention, significant coronary artery disease or left ventricular ejection fraction (LVEF) <50% were excluded. Clinical and echocardiographic data, including TR grade and right ventricular (RV) size and function, were assessed at baseline and at the 1-year follow-up. At baseline, significant TR was documented in 13 patients (11.1%) and non-significant TR was documented in 103 patients (88.9%). Atrial fibrillation (AF) was more prevalent in patients with a tricuspid annulus diameter ≥40 mm (P < 0.0051). At the 1-year follow-up, the TR grade had improved in 17 patients (14.7%), was unchanged in 68 patients (58.6%) and had worsened in 31 patients (26.7%). Moderate to severe TR was found in 30 patients (25.8%). Tricuspid annulus diameter >40 mm was the only echocardiographic predictor of significant postoperative TR (relative risk (RR) = 2.12 [1.26-3.54], P = 0.004). Right heart function and size were not independent predictors. Conclusion Significant TR was present pre-operatively in 11.1% of patients. Post-operative progression was observed in 26.7% of patients. Only tricuspid annulus size >40 mm was an independent echocardiographic predictor of moderate to severe TR at the 1-year follow-up.

Sensitivity Analysis and Parameter Estimation of a Coronary Circulation Model for Triple-Vessel Disease

Mathematical models of the coronary circulation have been shown to provide useful information for the analysis of intracoronary blood flow and pressure measurements acquired during coronary artery bypass graft (CABG) surgery. Although some efforts towards the patient-specific estimation of model parameters have been presented in this context, they are based on simplifying hypotheses about the collateral circulation and do not take advantage of the whole set of data acquired during CABG. In order to overcome these limitations, this paper presents an exhaustive parameter sensitivity analysis and a multiobjective patient-specific parameter estimation method, applied to a model of the coronary circulation of patients with triple vessel disease. The results of the sensitivity analysis highlighted the importance of capillary and collateral development. On the other hand, the estimation method was applied to intraoperative clinical data from ten patients obtained during CABG, which permitted to assess patient-specific collateral vessel situations. These approaches provide new insights regarding the heterogeneous configuration of the collateral circulation.

A more sensitive pressure-based index to estimate collateral blood supply in case of coronary three-vessel disease.

With progressive occlusion of a coronary main artery, some anastomotic vessels are recruited in order to supply blood to the ischemic region. This collateral circulation is an important factor in the preservation of the myocardium until reperfusion of the area at risk. An accurate estimation of collateral flow is crucial in surgical bypass planning as it alters the blood flow distribution in the coronary network and can influence the outcome of a given treatment for a given patient. The evaluation of collateral flow is frequently achieved using an index based on pressure measurements. It is named Collateral Flow Index (CFI) and defined as: (P(w)-P(v))/(P(ao)-P(v)), where P(w) is the pressure distal to the thrombosis, P(ao) the aortic pressure and P(v) the central venous pressure. We propose here another index, that is more sensitive to the P(w) value and could thus describe the role of collateral flow with more precision. We illustrate this idea using some clinical pressure measurements in patients with severe coronary disease (stenoses on the left branches and total occlusion of the right coronary artery).

Intraoperative tracking of aortic valve plane

The main objective of this work is to track the aortic valve plane in intra-operative fluoroscopic images in order to optimize and secure Transcatheter Aortic Valve Implantation (TAVI) procedure. This paper is focused on the issue of aortic valve calcifications tracking in fluoroscopic images. We propose a new method based on the Tracking-Learning-Detection approach, applied to the aortic valve calcifications in order to determine the position of the aortic valve plane in intra-operative TAVI images. This main contribution concerns the improvement of object detection by updating the recursive tracker in which all features are tracked jointly. The approach has been evaluated on four patient databases, providing an absolute mean displacement error less than 10 pixels (≈2mm). Its suitability for the TAVI procedure has been analyzed.

Theoretical study of the flow rate toward the right heart territory in case of total occlusion of the right coronary artery

In this work, patients with severe coronary disease and chronic occlusion of the right coronary artery (RCA) are studied. In this clinical situation, the collateral circulation is an important factor in the preservation of the myocardium until reperfusion of the area at risk. An accurate estimation of collateral flow is crucial in surgical bypass planning as it can influence the outcome of a given treatment for a given patient. The evaluation of collateral flow is frequently achieved using an index (CFI, Collateral Flow Index) based on pressure measurements. Using a model of the coronary circulation based on hydraulic/electric analogy, we demonstrate, through theoretical simulations, that a wide range of fractional collateral flow values can be obtained for any given distal pressure difference depending on the values of the capillary and collateral resistances.

Sealing zones have a greater influence than iliac anatomy on the occurrence of limb occlusion following endovascular aortic aneurysm repair.

Limb occlusion is a well-known complication following endovascular aortic aneurysm repair (EVAR), and it very often leads to reoperation. The aim of this study is to identify predictive factors for limb occlusion following EVAR. Two hundred and twenty-four patients undergoing EVAR between 2004 and 2012 were included in this retrospective study. Demographics, anatomic, and follow-up data were compared between two groups (with or without thrombosis). Preoperative anatomy was analyzed with a dedicated workstation, using the Society of Vascular Surgery reporting standards. Eleven (4.9%) patients presented with a limb occlusion during follow-up (46 ± 12 months). Univariate analyses were first performed to investigate the influence of preoperative variables on limb occlusion. Then, variables with a p value <0.1 were included in the multivariate analysis and showed that in the occlusion group there was a greater rate of chronic renal failure (18.2% vs. 3.8%, p = 0.012), a more frequent occurrence of distal landing zones in the external iliac artery (15.4% vs. 2.1%, p = 0.006), and a smaller aortic neck diameter (21.0 ± 2.9 mm vs. 23.6 ± 3.3 mm, p = 0.014). Although iliac anatomy does not appear to have a significant influence on limb occlusion rate in the multivariate analysis, proximal and distal sealing zones appear to be involved in this complication.

Decision support system for the planning of minimally invasive aortic valve replacement surgery

PurposeMinimally invasive aortic valve replacement (MIAVR) procedures remain more complex and technically challenging compared to conventional full sternotomy surgery. This technique involves a restricted surgical field and a limited workspace, which is, at present, strictly reserved for the most experienced surgeons. The MIAVR clinical outcomes are strongly dependent on the appropriate choice of the thoracic incision. This work presents a decision support system to optimize, through an interactive visualization interface, the exposure of the target structure in a limited field of view.MethodsOur approach is based on the computation of relevant anatomical measurements from preoperative CT images, and it takes into account the surgical guidelines in order to propose the surgical access that best fits the patient’s morphology.ResultsThe proposed planning system was applied and tested on 30 datasets from patients affected by severe aortic stenosis for validation purposes. We evaluated the accuracy of the automatic detections and the measurements calculated by the system with those chosen manually by the expert.ConclusionsIn 87% of thirty cases, the surgical strategy proposed by the decision support system was correct. For the remaining cases, the graphical user interface (GUI) allowed the user to manually adjust the anatomical features.

Position paper of French Interventional Group (GACI) for TAVI in France in 2018

Aortic stenosis is a frequent disease in the elderly. Its prevalence is 0.4% with a sharp increase after the age of 65, and its outcome is very poor when the patient becomes symptomatic. The interventional procedure known as TAVI (trans-catheter aortic valve implantation), which was developed in France and carried out for the first time in Rouen by Prof. Alain Cribier and his team in 2002, has proven to be a valid alternative to surgical aortic valve replacement. At first, this technique was shown to be efficient in patients with contra-indications to surgical treatment or deemed to be at high surgical risk. Given the very promising outcomes achieved as a result of close heart team collaboration, appropriate patient selection, simplified procedures and reduced complication rates, transfemoral (TF) TAVI is now preferred in symptomatic intermediate risk patients>75 years old according to the latest ESC guidelines. In 2017, in France, TAVI is currently performed in 50 centers with on-site cardiac surgery. The 2016 TAVI outcomes recorded in the French national TAVI registry (France TAVI) are very encouraging and show that for 7133 patients treated (age 83.4±7 years, logistic Euroscore 14%), 87% of whom via the TF approach, cross-over to surgery was very low (0.5%) with a 3.0% in-hospital mortality rate. The substantial increase in TAVI indications and the improvement of its outcomes may in the near future call for a reconsideration of the number of high volume centers authorized to carry out this technique.

Transcatheter Aortic Valve Implantation Versus Surgical Aortic Valve Replacement in Lower–Surgical-Risk Patients With Chronic Obstructive Pulmonary Disease

Respiratory complications are a major factor contributing to postoperative morbidity and mortality, especially in patients with chronic obstructive pulmonary disease (COPD). Our objective was to compare the rate of respiratory complications in patients with COPD with severe aortic stenosis who underwent transcatheter aortic valve implantation (TAVI) versus surgical aortic valve replacement (SAVR). Low-to-intermediate surgical-risk patients with moderate or severe COPD who underwent TAVI or SAVR at 2 tertiary centers were included in this study. COPD was defined by the Global Initiative for Chronic Lung Disease classification. The primary end point was the 30-day composite of respiratory mortality, prolonged ventilation (>24 hours), the need for reintubation for respiratory causes, tracheostomy, acute respiratory distress syndrome, pneumonia, or pneumothorax. The inverse probability of treatment weighting was determined to reduce baseline imbalance between the 2 groups. A total of 321 patients (mean age 72.4 ± 9.3 years old, 74.5% male, mean Society of Thoracic Surgeons predicted risk of mortality 3.8 ± 1.9%, mean forced expiratory volume 1: 59 ± 13%) were included in the analysis. TAVI was performed in 122 patients, whereas 199 underwent SAVR. There were no differences between the 2 groups regarding the composite respiratory primary end point (SAVR 10.6%, TAVR 7.4%, adjusted odds ratio 0.57, 95% confidence interval 0.20 to 1.65, p = 0.30). Transfemoral TAVI without general anesthesia (28 patients) was associated with the lowest rate of respiratory complications (3.6%). Among patients with moderate or severe COPD at low-to-intermediate surgical risk, TAVI patients had a similar rate of 30-day major pulmonary complications compared with SAVR patients despite a higher baseline risk profile. Future studies should further investigate whether TAVI is associated with reduced respiratory complications, comparing transfemoral TAVI recipients treated with local anesthesia with their SAVR counterparts.

Analyse rétrospective portant sur 50 tumeurs épithéliales thymiques au CHU de Rennes. Quelle concordance avec le référentiel RYTHMIC publié en 2010

BACKGROUND Thymic epithelial tumors (TET), including thymomas and thymic carcinomas, are rare and characterized by very different evolutionary patterns depending on histology and invasion stage. The therapeutic management is not well defined but is a subject of increasing interest. The descriptive and analytic objectives of this retrospective monocentric study were to analyze the clinical characteristics of patients with TET, and to assess the management of these tumors in our centre. METHODS Adult patients with TET managed in the Rennes university hospital in the period 2000-2011 were selected via the pathology department. Their clinical and pathological features and survival were analyzed retrospectively. RESULTS Fifty TET were retrieved (46 thymomas and 4 thymic carcinomas). Their clinical and histological features and their invasion stages were concordant with published studies. Their diagnostic and therapeutic managements were also in accordance with current guidelines. In univariate analysis, myasthenia and surgery were associated with better survival rates. CONCLUSION Management of TET in Rennes university hospital is in accordance with guidelines.