Anatomical and biometric study of the radial artery on human cadavers dissected in the anatomy laboratory.

OBJECTIVE: To study the anatomy and biometry of the radial artery and to report the implications of this study for daily practice in Cardiac Surgery. METHOD: Radial arteries from 45 human cadavers (28 males and 17 females, average age 79.2 (92) fixed in 10% formalin were dissected. The proximal and distal internal calibers and lengths of these radial arteries were measured. RESULTS: Our results showed the presence of a single radial artery variation in 2.3% of the entire sample (1.1% of the 90 dissected upper limbs). The distance between the epicondyle and the emergence of the radial artery was 32.4 (6.67) mm in men and 30.7 (9.00) mm in women, with an average of 31.8 (7.58) mm. For the right upper limb, the mean proximal internal caliber of the radial artery was 3.16 (0.56) mm and its mean distal internal caliber was 2.62 (0.66) mm. For the left upper limb, the mean proximal internal caliber of the radial artery was 3.17 (0.59) mm and its mean distal internal caliber was 2.64 (0.68) mm. The mean length of the left radial artery was 197.0 (17) mm. The mean length of the right radial artery was 201.0 (33) mm. CONCLUSION: It is very important to be aware of the possible anatomical variation of the radial artery. Despite its rarity, this knowledge may ensure a better safety and reliability of the harvesting technique for use as a graft.

Anatomical and biometric study of the mitral valve apparatus: application in valve repair surgery.

OBJECTIVE: Most mitral valve repair techniques provide excellent surgical results by removing regurgitation, but all of these techniques simultaneously reduce posterior valve mobility. A comprehensive biometric study of the mitral valve apparatus will provide landmarks that would help improve this posterior valve mobility. MATERIALS AND METHODS: Thirty one (31) human hearts have been studied, from 14 women and 17 men. The characteristics of the studied sample were analyzed descriptively. The difference in means of the variables between women and men were tested using a Student t test. Correlations between the different measures were determined by simple regression analysis. Mean values are shown with ± 1 standard deviation and the limit of significance was set at 0.05. RESULTS: The mean weight of the hearts was 275.3 ± 2.4 g. The anteroposterior diameter of the mitral annulus was 29.3 ± 1.22 mm, the intertrigonal distance was 25.2 ± 3.50 mm and the anterior leaflet to posterior leaflet ratio was 1.9 ± 0.10, the length of the chordae A2 = 19.4 ± 1.15 mm and P2 = 14.5 ± 0.85 mm. The length of the anterior papillary muscle averaged 30.9 ± 7.20 mm and that of the posterior one 30.0 ± 8.75 mm. The comparison of the different values measured between women and men showed no statistically significant difference (p > 0.05). There was no correlation between these different measured values (p > 0.05). CONCLUSION: A perfect knowledge of anatomy and biometry is therefore essential to offer alternative techniques that reproduce the real anatomy and physiology with a complete reconstruction of the mitral valve.

Incidence, predictors, impact, and treatment of vascular complications after transcatheter aortic valve implantation in a modern prospective cohort under real conditions.

OBJECTIVE: Vascular complications (VCs) occurring in transcatheter aortic valve implantation (TAVI) procedures have frequently been reported in the past. Considering significant technical improvements in delivery systems and vascular closure devices, the goal of this study was to determine the incidence, impact, and prognostic factors of VCs in a recent real-world cohort. METHODS: We report a bicentric prospective analysis of 479 consecutive patients who underwent TAVI between January 2017 and December 2017. VCs were defined according to criteria set out by the Valve Academic Research Consortium (VARC)-2. RESULTS: The incidence of VCs was 26.1% (n = 125 patients), of which 2.9% were major (n = 14) and 23.2% were minor (n = 111). VCs were related to the primary puncture point in 69% of cases compared with 31% at the secondary puncture site. Treatments implemented were medical in 76% of cases and surgical in 24% of cases. The risk factors for VCs were as follows: iliac morphology score, sheath to iliofemoral artery ratio (SIFAR), and moderate-severe iliofemoral calcifications or tortuosity. In the case of major VCs, only sheath to iliofemoral artery ratio was a risk factor. Major VCs significantly increased intrahospital mortality (30.7% vs 1.1% for minor VCs and 1.3% for no VCs; log-rank, P < .0001) and 1-year mortality (40.6% vs 5.6% for minor VCs and 5.6% for no VCs; log-rank, P < .0001). CONCLUSIONS: Using strictly VARC-2 end point definitions, more than one-quarter of TAVI procedures were associated with VCs, primarily minor ones. Secondary puncture points were responsible for one-third of VCs and should therefore also be actively monitored. Major VCs have a significant impact on short-term and midterm survival.

Transcarotid Approach for Transcatheter Aortic Valve Replacement With the Sapien 3 Prosthesis: A Multicenter French Registry.

OBJECTIVES: This study sought to describe the procedural and clinical outcomes of patients undergoing transcarotid (TC) transcatheter aortic valve replacement (TAVR) with the Edwards Sapien 3 device. BACKGROUND: The TC approach for TAVR holds the potential to become the optimal alternative to the transfemoral gold standard. Limited data exist regarding safety and efficacy of TC-TAVR using the Edwards Sapien 3 device. METHODS: The French Transcarotid TAVR prospective multicenter registry included patients between 2014 and 2018. Consecutive patients treated in 1 of the 13 participating centers ineligible for transfemoral TAVR were screened for TC-TAVR. Clinical and echocardiographic data were prospectively collected. Perioperative and 30-day outcomes were reported according to the updated Valve Academic Research Consortium (VARC-2). RESULTS: A total of 314 patients were included with a median (interquartile range) age of 83 (78 to 88) years, 63% were males, Society of Thoracic Surgeons mortality risk score 5.8% (4% to 8.3%). Most patients presented with peripheral artery disease (64%). TC-TAVR was performed under general anesthesia in 91% of cases, mostly using the left carotid artery (73.6%) with a procedural success of 97%. Three annulus ruptures were reported, all resulting in patient death. At 30 days, rates of major bleeding, new permanent pacemaker, and stroke or transient ischemic attack were 4.1%, 16%, and 1.6%, respectively. The 30-day mortality was 3.2%. CONCLUSIONS: TC-TAVR using the Edwards Sapien 3 device was safe and effective in this prospective multicenter registry. The TC approach might be considered, in selected patients, as the first-line alternative approach for TAVR whenever the transfemoral access is prohibited. Sapien 3 device was safe and effective in our multicenter cohort.

Aortic treatment of native infection by reconstruction with the Omniflow II biologic prosthesis.

Aortic infection is a challenging condition. Fortunately, surgical revision of infected aorta with in situ reconstruction can provide long-term cure. The material for aortic repair remains an area of debate. The Omniflow II (LeMaitre Vascular, Burlington, Mass) prosthesis is a biosynthetic graft made to resist long-term degeneration and allows growth of host tissue with reduction of the risk of arterial infection. It has already been used for peripheral bypass with very low infection rates. Herein, we describe an original case of first-line native aorta replacement by a straight Omniflow II biologic prosthesis for infected aortic aneurysm.

Evolution of Length of Stay After Surgical and Transcatheter Aortic Valve Implantation Over 8 Years in 1,849 Patients >75 Years of Age and Comparison Between Transfemoral and Transsubclavian Transcatheter Aortic Valve Implantation.

Minimized length of hospitalization (LoS) and lower risk of hospitalization-related complications are key requirements in the treatment of aortic valve disease, mainly in the elderly candidates. Our objective was to evaluate evolution of LoS after surgical (SAVR) or transcatheter aortic valve implantation (TAVI) and its predictors. We enrolled 1,849 elderly (aged >75) patients receiving SAVR or TAVI from 2009 to 2016. In the surgical cohort (n = 1,006) the mean LoS slightly decreased from 13.81 ± 9.27 days (2009) to 10.96 ± 3.77 (2016); in the TAVI cohort (n = 843), LoS passed from 13.33 ± 9.17 (2009) to 6.21 ± 4.30 days (2016). All-cause mortality at 1 month was 3.77 % (SAVR) versus 4.7% (TAVI) (p >0.05). Among Transfemoral TAVI (TF, n = 681), and Transsubclavian TAVI (TS, n = 62), average LoS was comparable (7.38 days ± 7.11 vs 7.31 ± 4.32; median 6.0 and 6.0 days, p = 0.07). Procedural success was reached in 93% (TF) and in 85.4% (TS) (p = 0.20). There were no meaningful differences among TF and TS in terms of VARC-2 postprocedural morbidity, except for the rate of vascular access-related complications; these occurred in 8.8% of cases in the TF group versus 1.6% in the TS group (p = 0.05). In conclusion the present analysis showed a faster improvement in terms of LoS for TAVI compared with SAVR over 8 years of activity. The 2 strategies presented comparable all-causes mortality at 30 days. LoS, rates of procedural success and complications were comparable among TF and TS TAVI; nonetheless, vascular access-related complications were more frequent in the TF cohort. This suggests the validity of the TS route as an alternative to the TF approach.

Combined Coronary Revascularization: Single-Center 10-Year Experience.

OBJECTIVE: This study aimed to assess the long-term outcome of combined coronary revascularization. METHODS: Between January 2000 and September 2010, 106 consecutive patients underwent combined coronary revascularization, either the same day or staged within 90 days. Percutaneous coronary intervention was always performed before coronary artery bypass grafting. We identified three groups as follows: one-stop combined coronary revascularization (n = 20), percutaneous coronary intervention for acute coronary syndrome before subsequent surgery (n = 39), and percutaneous coronary intervention for stable coronary artery disease before subsequent surgery (n = 47). Off-pump technique was used in all cases. RESULTS: A total of 107 angioplasties were realized (drug-eluting stents, 21; bare metal stents, 114; balloon angioplasty, 4). Percutaneous coronary intervention was mostly performed in the right coronary artery or branches (85%). The mean (SD) number of grafts was 1.9 (0.6), among them 1.8 (0.7) with arterial grafts. A total of 87.7% of the patients underwent exclusive arterial revascularization. There was one reexploration for bleeding and no in-hospital death. Eleven patients died in the follow-up. Repeat percutaneous coronary intervention was necessary for six patients and repeat surgery for one patient. The mean (SD) follow-up was 6.1 (2.7) years. Complete follow-up was obtained in 96.2% of the patients. Freedom from ischemic events (all-cause deaths, angina, acute coronary syndrome, myocardial infarction) was 86.3% (3.7%) at 5 years and 79.7% (5.2%) at 8 years (no difference between groups). Freedom from major adverse cardiac or cerebrovascular events was 88.8% (3.4%) at 5 years and 75.7% (5.2%) at 8 years (no difference between groups). CONCLUSIONS: Combined coronary revascularization increases the use of arterial grafts, with good long-term outcome.

Appraisal of Long-Term Outcomes of Tricuspid Valve Replacement in the Current Perspective.

BACKGROUND: We address the differential long-term results of tricuspid valve replacement and late valve-related events among bioprostheses versus mechanical prostheses. METHODS: In a single-institution investigation, we reviewed the patients' prospectively collected data and performed a clinical follow-up. Both the Kaplan-Meier (actuarial) and the competing risks (actual) methodologies were used. RESULTS: Overall, 188 tricuspid valve replacements were performed during 1971 to 2012. In this complex population (reoperations, 48.1%; associated procedures in 71.3%), operative mortality was 27.6% (significantly declining in recent years). A bioprosthesis was used in 82.4%. Follow-up was 10.2 ± 9.1 years (as long as 37.3 years, or 1,270 patient-years; 91.2% complete). At 15 years, freedom from structural valve deterioration was 93.3% ± 6.4% (competing risks 94.7 ± 5.1%) in the mechanical group and 85.2% ± 5.4% (competing risks 92% ± 2.9%) in the bioprostheses group (p = 0.19). Freedom from any valve-related adverse events was lower among mechanical valves versus bioprostheses (although not statistically significant). Mechanical valves showed significantly lower freedom from thromboembolic events (actuarial 62.3% ± 14.3% versus 97.7% ± 1.6%; competing risks 74.1% ± 10% versus 98% ± 1.4%; p < 0.001) and earlier adverse events (4.9 ± 4.5 versus 11.1 ± 9.4 years) than bioprostheses. There were 11 reoperations for bioprosthetic structural valve deterioration (89.8% and 94.3% actuarial and actual freedom, respectively). CONCLUSIONS: Bioprostheses for tricuspid valve replacement have a very good long-term durability. Mechanical valves display earlier and more severe morbidity at follow-up.

Is the EuroSCORE II best suited for reoperative risk estimation in patients with structural deterioration of aortic bioprostheses?

BACKGROUND: Operative risk prediction systems (logistic EuroSCORE I, EuroSCORE II and STS Score) are employed together with multidisciplinary discussion to contraindicate conventional surgery in patients with valvular heart disease and propose the employment of alternative transcatheter procedures. The EuroSCORE I has been reported to underperform in these circumstances; we hypothesize that the EuroSCORE II is best suited for the stratification of risk in patients with structural deterioration (SVD) of valvular bioprostheses and potential candidates to the Valve-in-Valve procedure (deployment of a transcatheter valve within a failing valvular bioprosthesis). METHODS AND EVALUATION OF THE HYPOTHESIS: A multi-institutional collaboration is required to fully address such hypothesis. Therefore, we performed a preliminary validation study by retrieval of the complete records of 81 patients undergoing reoperative aortic valve replacement for preoperative diagnosis of bioprosthetic SVD at our Institution. Logistic EuroSCORE I, EuroSCORE II and STS Score were calculated by preoperatively available data. Faced to an observed reoperative mortality of 4.9%, average EuroSCORE I was 15.8%±13.4, EuroSCORE II was 7.3%±7.4 and the STS Score was 15%±9.8. The three systems provided sufficient adequacy (Hosmer-Lemeshow p=0.847, p=0.999 and p=0.9948, respectively). Yet, the area under the ROC curve was significantly higher for the EuroSCORE II (0.9903) vs. the EuroSCORE I (0.8994) (p=0.044). The STS Score yielded an intermediate figure (0.9643). The odds ratios (logistic regression) were 1.079 for EuroSCORE I, 1.223 for the STS Score and 1.474 for EuroSCORE II. CONCLUSIONS: The three investigated algorithms showed reasonable calibration in the prediction of mortality for reoperative aortic valve replacement, but they evenly overestimated the observed mortality. The hypothesis that the EuroSCORE II is better suited for the selection of candidates to Valve-in-Valve implantation is worth of further multi-institutional investigations on the basis of our preliminary findings and due to the expanding role of transcatheter techniques.

Combined frozen elephant trunk and endovascular repair for extensive thoracic aortic aneurysms.

BACKGROUND: We describe a 1-step treatment of extensive arch and descending aortic aneurysm by combination of frozen elephant trunk (FET) (hybrid endoprosthesis) and of conventional endoprosthesis deployment. METHODS: In a single-center, prospective, treatment-only study, the clinical data of 4 patients receiving combined FET and distal endoprosthesis deployment in the descending aorta were prospectively collected. Thoracic endoprostheses were deployed either retrogradely (off-pump from the femoral arterial access) or antegradely (from the aortic arch during hypothermic arrest). A distal-first approach was used ("trombone" mechanism). Spinal cord protection was achieved by transposition of the left subclavian artery to the left common carotid artery and selective antegrade cerebral perfusion. Preoperative computed tomography scan was performed to identify the collateral circulation. Preoperative planning was assisted by a sizing software (Endosize, Therenva Inc.). RESULTS: The aortic coverage was extended down to the orifice of the celiac trunk in one case and to the T8 level in the remainders. There was no operative mortality, 1 transient paraparesis, and 1 case of renal insufficiency. Follow-up results were satisfying (no device migration, no endoleak, no endotension, and no late neurologic complications). CONCLUSIONS: The present strategy may abolish the risks connected with the waiting time between the surgical first step and the later completion (aortic-related adverse events and drop-out) and deserves further investigations to determine its safety and feasibility profile.

Feasibility of Valve-in-Valve Procedure for Degenerated St. Jude Medical Trifecta Bioprosthesis.

The valve-in-valve (ViV) procedure is an option for patients with symptomatic structural degeneration of a bioprosthesis and excessive reoperative risk. The risk of coronary obstruction appears to be increased if ViV is performed for certain pericardial prostheses in which the leaflets are mounted outside the stent posts. Herein is described a successful ViV for a degenerated Trifecta aortic bioprosthesis, and the technical considerations for performing a ViV procedure within such types of prosthesis are considered. Emphasis is placed on the importance of preoperative investigations (computed tomography scan-based measurements of coronary ostial height and of sinus of Valsalva diameters), and on the precise deployment of the valve (transapical approach with transesophageal echocardiography control) to minimize the risk of major complications. The presence of a failing Trifecta bioprosthesis should not be considered an absolute contraindication to ViV on the basis of the risk of coronary obstruction.

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.

Long-term results of the Medtronic Mosaic porcine bioprosthesis in the aortic position.

OBJECTIVE: We addressed the long-term results of the Medtronic Mosaic porcine prosthesis in the aortic position. METHODS: From 1994 to 2004, 1007 Mosaic valves were used for aortic valve replacement. The data were prospectively collected, retrospectively analyzed, and stratified according to patient age at surgery (group 1, <70 years; group 2, 70-75 years; group 3, 76-80 years; and group 4, >80 years), using both actual (cumulative risks) and actuarial methods. RESULTS: Operative mortality was 5% (valve related in 14%). Globally, 8122.17 patient-years were available (average follow-up, 8.5 ± 3.9 years; 99.8% complete). Overall, survival at 15 years was lower among the elderly strata (P < .0001). Freedom from structural valve deterioration (SVD) was 95.1% (actual) and 86.3% (actuarial; 24 SVD events). Survival free from SVD was lower in group 1 (P = .003) but comparable among the other groups. Overall freedom at 15 years from the composite endpoint (any valve-related adverse events) was 82% (actual) and 71.3% (actuarial). No meaningful intergroup differences were found in survival free from the composite endpoint (P = .9) or freedom from valve-related mortality (P = .8). Younger patients at surgery did not show accelerated degeneration. No relationship could be established between prosthetic size and SVD. CONCLUSIONS: The implantation of a bioprosthesis in patients aged 70 years or older remains fully justified. The rate of SVD was higher in younger patients, mainly owing to their greater life expectancy. Patients younger than 70 can receive a bioprosthesis, provided that the correct information regarding the expected durability has been provided. This might be better accomplished through the actual methodology.

Predictors of 6-month poor clinical outcomes after transcatheter aortic valve implantation.

BACKGROUND: Patient selection for transcatheter aortic valve implantation (TAVI) remains a major concern. Indeed, despite promising results, it is still unclear which patients are most and least likely to benefit from this procedure. AIMS: To identify predictors of 6-month poor clinical outcomes after TAVI. METHODS: Patients who were discharged from our institution with a transcatheter-implanted aortic valve were followed prospectively. Our population was divided into two groups ('good outcomes' and 'poor outcomes') according to occurrence of primary endpoint (composite of all-cause mortality, all stroke, hospitalizations for valve-related symptoms or worsening heart failure from discharge to 6 months or 6-month New York Heart Association functional class III or IV). Patient characteristics were studied to find predictors of poor outcomes. RESULTS: We included 163 patients (mean age, 79.9 ± 8.8 years; 90 men [55%]; mean logistic EuroSCORE, 18.4 ± 11.4%). The primary endpoint occurred in 49 patients (mean age, 83 ± 5 years; 31 men [63%]). By multivariable analysis, atrial fibrillation (odds ratio [OR] 3.94), systolic pulmonary artery pressure ≥60 mmHg (OR 7.56) and right ventricular dysfunction (OR 3.55) were independent predictors of poor outcomes, whereas baseline aortic regurgitation ≥2/4 (OR 0.07) demonstrated a protective effect. CONCLUSION: Atrial fibrillation, severe baseline pulmonary hypertension and right ventricular dysfunction (i.e. variables suggesting a more evolved aortic stenosis) were predictors of 6-month poor outcomes. Conversely, baseline aortic regurgitation ≥2/4 showed a protective effect, which needs to be confirmed in future studies. Our study highlights the need for a specific 'TAVI risk score', which could lead to better patient selection.

Multiobjective patient-specific estimation of a coronary circulation model for triple vessel disease.

Computational models can help understand the hemodynamics of the coronary circulation, which is of the upmost importance to help clinicians before, during and after a coronary artery bypass graft surgery. In this paper, we propose a multiobjective optimization method for parameter estimation of a computational model representing the coronary circulation on patients with a triple vessel disease. This estimation was not based on any assumption regarding the development of the collateral circulation, like in previous works. Indeed, the collateral development of a given patient is estimated through the model parameters. Parameter estimation was performed using clinical data from three patients, obtained before and during an off-pump coronary artery bypass graft surgery (CABG). Results showed a better performance when comparing the simulation with clinical data, since the total error estimation for three patients was reduced by 40 ± 22%. Moreover, the proposed method provides new insight regarding the heterogeneous configuration of the alternative collateral vessels.

Logistic EuroSCORE I risk analysis in aortic valve reoperations after bioprosthetic replacement.

BACKGROUND AND AIM OF THE STUDY: The aim was to evaluate the early and long-term results of redo-aortic valve replacement (AVR) for dysfunctioning bioprostheses, according to the type of bioprosthesis failure. The performance of the EuroSCORE in predicting operative mortality was addressed. METHODS: A retrospective analysis was performed of 164 patients who had undergone redo-AVR at the authors' institution. All data were collected prospectively. The type of bioprosthesis failure was categorized as either structural valve dysfunction (SVD), non-structural vale dysfunction (NSVD), or infective endocarditis (IE). The logistic EuroSCORE I was obtained, and a formal analysis of its predictive performance was conducted. RESULTS: The mean logistic EuroSCORE was 26.3 +/- 20.6%, while the observed operative mortality was 10.6%. The EuroSCORE overestimated mortality in all subgroups of indication; operative mortality was higher among the NSVD (14.7%) and IE (13.9%) groups, and lower among SVD patients (8.5%). The performance of the EuroSCORE in predicting mortality was better in SVD patients, and worse in NSVD patients (areas under the ROC curve of 0.857 and 0.751, respectively). Only patient-related factors independently predicted the operative mortality (logistic regression). The SVD patients displayed a significantly better long-term survival compared to NSVD and IE patients. Patient-related factors were seen to be the determinants of long-term survival. CONCLUSION: Redo-AVR can be performed with good early and long-term results, despite a high predicted risk. The logistic EuroSCORE I globally overestimates the risk, and its performance varies considerably according to the indication for redo-AVR. Therefore, it should not be used to determine the application of valve-in-valve procedures. The type of indication for redo-AVR (SVD, NSVD, IE) defines three different profiles of patients having distinctive early and long-term behaviors.

Blunt traumatic aortic rupture of the proximal ascending aorta repaired by resection and direct anastomosis.

Traumatic aortic injury represents 15% of motor vehicle related deaths with death occurring at the scene in 85% of the cases. Aortic disruptions usually occur at the isthmus in a transverse fashion with all three of the aortic layers being involved. Herein, we report the case of a 68-year old man with no prior medical history who was struck by a vehicle while riding his bicycle. The ruptured segment of aorta was resected circumferentially and interrupted horizontal mattress pledgeted prolene sutures were used to ensure full thickness aortic integrity of the proximal and distal aortic segments. The aorta was closed with a single-layer technique using 4/0 prolene suture. There were no postoperative complications and patient was discharged on Day 44. The case here discussed demonstrates a rare presentation of blunt aortic injury. The proximal ascending aorta is an unusual site of transection following blunt trauma with few reports in the literature. We were able to repair the aorta with direct suture, thus avoiding the use of artificial material.

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.

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).

Extracorporeal membrane oxygenation support for abdominal aortic aneurysms surgery in high-risk patients.

Surgical treatment of an abdominal aortic aneurysm in patients with a heart disease is risky. Aortic cross-clamping is featured by important consequences on cardiac, renal and gastrointestinal functions. Endovascular aortic repair is considered to be the gold standard in patients with severe comorbidities. However, in the case of unsuccessful endovascular treatment, surgery can be reconsidered with the use of extracorporeal membrane oxygenation, which seems to be a new tool for the management of cardiac and gastrointestinal events ensuring better post-operative outcomes.