Small access (30F) clinical central venous smart cannulation: is it adequate?

OBJECTIVES: To assess the performance of 45F vs. 36F smartcanula in CPB with gravity drainage alone. METHODS: Twenty patients were randomly assigned to two groups receiving for venous drainage a smartcanula which is collapsed over a mandrel for trans-atrial insertion into the inferior vena cava and expanded in situ to either 45F or 36F. RESULTS: Valve replacement/repair was realized in 7/10 and/or CABG in 6/10 for 36F (69+/-13 years) vs. 5/10 and 5/10, respectively, for 45F (63+/-11 years: NS). Body weight and surface area (BSA) were 83+/-9 kg (1.9+/-0.2 m2, max 2.2 m2) for 36F vs. 79+/-6 kg: NS (1.9+/-0.1 m2 (NS), max 2.1 m2) for 45F. Insertion and access orifice diameter (area) was 6 mm and 10 mm (78.5 mm2) for the 36F vs. 6 mm and 13 mm (132 mm2) for the 45F (+69%). Calculated target pump flow (2.4 l/min/m2) was 4.7+/-0.4 l/min for 36F vs. 4.5+/-0.3 l/min for 45F. Achieved pump flow accounted for 5.0+/-0.3 l/min for 36F (8% above target) vs. 4.8+/-0.3 l/min for 45F (8% above target): NS. The water balance during the pump run (clear volume added minus hemofilter and urine output) was 2.2+/-0.3 l for 36F vs. 2.0 l for 45F: NS. CONCLUSION: Due to its 'open' wall (the vena cava provides the seal), its reduced wall thickness (range: 0.0-0.4 mm), and its self-expanding design, the 36F smartcanula requiring a 30F access orifice has sufficient drainage capacity by gravity alone for full CPB in adults with a BSA up to 2.2 mm2.

Fosfomycin plus β-Lactams as Synergistic Bactericidal Combinations for Experimental Endocarditis Due to Methicillin-Resistant and Glycopeptide-Intermediate Staphylococcus aureus.

The urgent need of effective therapies for methicillin-resistant Staphylococcus aureus (MRSA) infective endocarditis (IE) is a cause of concern. We aimed to ascertain the in vitro and in vivo activity of the older antibiotic fosfomycin combined with different beta-lactams against MRSA and glycopeptide-intermediate-resistant S. aureus (GISA) strains. Time-kill tests with 10 isolates showed that fosfomycin plus imipenem (FOF+IPM) was the most active evaluated combination. In an aortic valve IE model with two strains (MRSA-277H and GISA-ATCC 700788), the following intravenous regimens were compared: fosfomycin (2 g every 8 h [q8h]) plus imipenem (1 g q6h) or ceftriaxone (2 g q12h) (FOF+CRO) and vancomycin at a standard dose (VAN-SD) (1 g q12h) and a high dose (VAN-HD) (1 g q6h). Whereas a significant reduction of MRSA-227H load in the vegetations (veg) was observed with FOF+IPM compared with VAN-SD (0 [interquartile range [IQR], 0 to 1] versus 2 [IQR, 0 to 5.1] log CFU/g veg; P = 0.01), no statistical differences were found with VAN-HD. In addition, FOF+IPM sterilized more vegetations than VAN-SD (11/15 [73%] versus 5/16 [31%]; P = 0.02). The GISA-ATCC 700788 load in the vegetations was significantly lower after FOF+IPM or FOF+CRO treatment than with VAN-SD (2 [IQR, 0 to 2] and 0 [IQR, 0 to 2] versus 6.5 [IQR, 2 to 6.9] log CFU/g veg; P < 0.01). The number of sterilized vegetations after treatment with FOF+CRO was higher than after treatment with VAN-SD or VAN-HD (8/15 [53%] versus 4/20 [20%] or 4/20 [20%]; P = 0.03). To assess the effect of FOF+IPM on penicillin binding protein (PBP) synthesis, molecular studies were performed, with results showing that FOF+IPM treatment significantly decreased PBP1, PBP2 (but not PBP2a), and PBP3 synthesis. These results allow clinicians to consider the use of FOF+IPM or FOF+CRO to treat MRSA or GISA IE.

The transventricular-transseptal access to the aortic root : a new route for extrapleural trans-catheter aortic stent-valve implantation

Rapport de synthèseObjectif: le remplacement valvulaire aortique par voie transcathétère est, actuellement, une méthode fiable indiquée pour des patients à haut risque porteurs d'une sténose valvulaire aortique. La voie transfémorale est utilisable seulement en cas d'absence de maladie vasculaire et la voie transapicale est contrindiquée en cas de dysfonction pulmonaire chronique sévère. Une alternative pour ne pas passer a travers l'espace pleural serait par voie sous- xiphoïdienne et trans-septale à travers le ventricule droit.Méthode: une expérience animale a été amené au laboratoire de recherche du CHUV. Cinq cochons (poids : 52.3±10.9 kg) ont été endormi et, sous anesthésie générale, le ventricule droit a été préparé a travers un accès sous- xiphoïdien. Ensuite, sous guide fluoroscopique et avec l'utilisation d'une échocardiographie intracardiaque, un accès trans-septal a été crée entre le ventricule droit et le ventricule gauche en utilisant des dilatateur de diamètre croissant (de 8F à 26F). Par la suite, une valve stentée crée dans le laboratoire en utilisant un stent en nitinol et du péricarde a été chargé dans une cartouche et introduite dans le ventricule gauche à travers un introducteur trans-septal. Enfin, la valve a été amené dans la chambre de chasse du ventricule gauche et ensuite dans la racine aortique et puis déployé au bon endroit. Quand le système a été retiré, le septum ventriculaire a pu être réparé par mise en place d'un système d'occlusion septal Amplazer. Trente minutes après la procédure, les animaux ont été sacrifié et le coeur a été analysé pour étudier le positionnement da la valve stentée, l'efficacité de la fermeture du septum inter-ventriculaire et la fermeture de la paroi du ventricule droit.Résultat : les cinq cochon ont tous eu un parfait positionnement et pose de la prothèse en position aortique au premier essai (efficacité 100%). Les procédures ont duré, moyennement, 49±4 minutes et la progressive dilatation de l'accès trans-septale à donné lieu à une communication inter-ventriculaire mesurable après dilatation avec du 18F et plus. Toutes les valves stentées ont été déployées au bon endroit avec un bon résultat du fonctionnement des valves prothétiques et absence d'insuffisance para prothétique. Pendant les procédures, des battement prématurés ainsi que des épisodes isolées de tachycardie supra ventriculaire ont été détectés. Par contre, il n'y a pas eu de bloc atrio-ventriculaire. Les pertes sanguines pendant les procédures étaient de 280±10mL, et les systèmes d'occlusion Amplatzer étaient tous bien déployés sans shunts inter-ventriculaires résiduels.Conclusion: la technique d'introduction de valve stentées par voie extrapleural (trans-ventriculaire et trans-septale) est techniquement possible et elle jette les bases pour le remplacement valvulaire aortique trans-ventriculaire sous anesthésie locale.

Mycobacterium tuberculosis aortic graft infection with recurrent hemoptysis: a case report.

INTRODUCTION: Mycobacterium tuberculosis may cause a large variety of clinical presentations due to its ability to disseminate by contiguity or hematogenously. Tuberculosis may remain undiagnosed for years due to the chronic course of the disease, with potentially life-threatening long-term complications. CASE PRESENTATION: In this case report, we describe a tuberculous aortic graft infection in a 72-year-old man documented by polymerase chain reaction and cultures. The patient presented with three episodes of hemoptysis following a remote history of miliary tuberculosis. The infection was treated by graft replacement and prolonged antimycobacterial therapy. CONCLUSION: Tuberculous infection of a vascular graft is an uncommon complication, but should be considered in patients with an intravascular device and a history of previous tuberculosis, especially when hematogenous spread may have occurred a few months after surgery, or when an active mycobacterial infection is present in close proximity to the graft.

Transcatheter stent-valve implantation in a stenotic pulmonary conduit via a sub-xyphoidian access

Patients who develop a severe stenosis in biological pulmonary conduits previously implanted for pulmonary outflow trunk reconstructions are treated either by surgical re-replacement, or by transcatheter stent-valve implantation through a femoral vein access. A catheter-based sub-xyphoidian access through the right ventricle for stent-valve positioning in a pulmonary conduit has rarely been proposed. We describe the case of a 20-year-old man who underwent a pulmonary trunk reconstruction for a congenital pulmonary valve dysplasia and a few years later developed a stenosis in the pulmonary conduit. He was successfully treated with a 23 mm Edwards Sapien stent-valve implantation in pulmonary position, through an unusual right ventricular, sub-xyphoidian access and without contrast medium injections and pleura opening.

Living-engineered valves for transcatheter venous valve repair.

Background: Chronic venous insufficiency (CVI) represents a major global health problem with increasing prevalence and morbidity. CVI is due to an incompetence of the venous valves, which causes venous reflux and distal venous hypertension. Several studies have focused on the replacement of diseased venous valves using xeno- and allogenic transplants, so far with moderate success due to immunologic and thromboembolic complications. Autologous cell-derived tissue-engineered venous valves (TEVVs) based on fully biodegradable scaffolds could overcome these limitations by providing non-immunogenic, non-thrombogenic constructs with remodeling and growth potential. Methods: Tri- and bicuspid venous valves (n=27) based on polyglycolic acid-poly-4-hydroxybutyrate composite scaffolds, integrated into self-expandable nitinol stents, were engineered from autologous ovine bone-marrow-derived mesenchymal stem cells (BM-MSCs) and endothelialized. After in vitro conditioning in a (flow) pulse duplicator system, the TEVVs were crimped (n=18) and experimentally delivered (n=7). The effects of crimping on the tissue-engineered constructs were investigated using histology, immunohistochemistry, scanning electron microscopy, grating interferometry (GI), and planar fluorescence reflectance imaging. Results: The generated TEVVs showed layered tissue formation with increasing collagen and glycosaminoglycan levels dependent on the duration of in vitro conditioning. After crimping no effects were found on the MSC level in scanning electron microscopy analysis, GI, histology, and extracellular matrix analysis. However, substantial endothelial cell loss was detected after the crimping procedure, which could be reduced by increasing the static conditioning phase. Conclusions: Autologous living small-diameter TEVVs can be successfully fabricated from ovine BM-MSCs using a (flow) pulse duplicator conditioning approach. These constructs hold the potential to overcome the limitations of currently used non-autologous replacement materials and may open new therapeutic concepts for the treatment of CVI in the future.

Comparison of radial deformability of stent posts of different aortic bioprostheses.

OBJECTIVES Little is known about the stent deformability required for optimal stented heart valve bioprosthesis design. Therefore, two bioprosthetic valves with known good long-term clinical results were tested. The strain in the radial direction of the stent posts of these valves was compared with contemporary bioprosthetic valves and a native porcine aortic root. METHODS Medtronic Intact and Carpentier-Edwards Standard (CES), and four contemporary bioprostheses, including one self-expanding prosthesis, were tested with three sonomicrometry probes per valve fixed at commissure attachment points. The mean values from 2400 data points from three measurements of the interprobe distances were used to calculate the radius of the circle circumscribed around the three probes. Changes in the radius of the aortic root at pressures 70-90 and 120-140 mmHg (pressure during diastole and systole) and that of the stent posts at 70-90 and 0-10 mmHg (transvalvular pressure gradient during diastole and systole) were compared. RESULTS An increase in radius by 7.3 ± 2.6, 8.7 ± 0.0 and 3.9 ± 0.0% for the porcine aortic root, CES and Intact valves, respectively, was observed during transition from diastolic to systolic pressure and less for contemporary bioprostheses-mean 2.5 ± 0.9%, lowest 1.2 ± 0.0. CONCLUSIONS The results indicate that the radial deformability of bioprosthetic valve stent posts can be as low as 1.2% for xenoaortic and 3.0% for xenopericardial prostheses with no compromise of valve durability. Although these results suggest that valve stent post-deformability might not be of critical importance, a concrete answer to the question of the significance of stent deformability for valve durability can be obtained only by acquiring long-term follow-up results for valve prostheses with rigid stents.

Imaging for trans-catheter pulmonary stent-valve implantation without angiography: role of intravascular ultrasound.

Patients with stenosed biologic pulmonary conduits require redo cardiac surgery to prevent severe right ventricular dysfunction. Following the latest trends, the trans-catheter pulmonary stent-valve implantation represents a new fascinating alternative carrying a lower operative risk, compared with the standard open-heart re-intervention. Traditionally, the pulmonary stent valve is positioned off pump, under fluoroscopic control, and requires angiographies. However, alternative tools not requiring contrast injections for the intra-operative cardiac imaging have to be also considered strongly. The usefulness of intravascular ultrasound for the positioning of aortic endoprosthesis has already been proven in previous reports and, following the same principle, we have started to routinely implant balloon-expandable stent valves (Edwards Sapien? THV) in stenosed pulmonary valve conduits using intravascular ultrasound for the stent-valve positioning without angiography. We describe the intra-operative intravascular imaging technique with technical details.

Treatment of ruptured abdominal aortic aneurysm, a permanent challenge or a waste of resources? Prediction of outcome using a multi-organ-dysfunction score.

OBJECTIVES: in a retrospective study, attempts have been made to identify individual organ-dysfunction risk profiles influencing the outcome after surgery for ruptured abdominal aortic aneurysms. METHODS: out of 235 patients undergoing graft replacement for abdominal aortic aneurysms, 57 (53 men, four women, mean age 72 years [s.d. 8.8]) were treated for ruptured aneurysms in a 3-year period. Forty-eight preoperative, 13 intraoperative and 34 postoperative variables were evaluated statistically. A simple multi-organ dysfunction (MOD) score was adopted. RESULTS: the perioperative mortality was 32%. Three patients died intraoperatively, four within 48 h and 11 died later. A significant influence for pre-existing risk factors was identified only for cardiovascular diseases. Multiple linear-regression analysis indicated that a haemoglobin <90 g/l, systolic blood pressure <80 mmHg and ECG signs of ischaemia at admission were highly significant risk factors. The cause of death for patients, who died more than 48 h postoperatively, was mainly MOD. All patients with a MOD score >/=4 died (n=7). These patients required 27% of the intensive-care unit (ICU) days of all patients and 72% of the ICU days of the non-survivors. CONCLUSION: patients with ruptured aortic aneurysms from treatment should not be excluded. However, a physiological scoring system after 48 h appears justifiable in order to decide on the appropriateness of continual ICU support.

Tropheryma whipplei bivalvular endocarditis and polyarthralgia: a case report.

INTRODUCTION: Tropheryma whipplei infection should be considered in patients with suspected infective endocarditis with negative blood cultures. The case (i) shows how previous symptoms can contribute to the diagnosis of this illness, and (ii) elucidates current recommended diagnostic and therapeutic approaches to Whipple's disease. CASE PRESENTATION: A 71-year-old Swiss man with a past history of 2 years of diffuse arthralgia was admitted for a possible endocarditis with severe aortic and mitral regurgitation. Serial blood cultures were negative. Our patient underwent replacement of his aortic and mitral valve by biological prostheses. T. whipplei was documented by polymerase chain reactions on both removed valves and on stools, as well as by valve histology. A combination of hydroxychloroquine and doxycycline was initiated as lifetime treatment followed by the complete disappearance of his arthralgia. CONCLUSIONS: This case report underlines the importance of considering T. whipplei as a possible causal etiology of blood culture-negative endocarditis. Lifelong antibiotic treatment should be considered for this pathogen (i) due to the significant rate of relapses, and (ii) to the risk of reinfection with another strain since these patients likely have some genetic predisposition.

Ventricularisation of the left atrium: a rare cause of left ventricular dysfunction in a patient with mitral valve prolapse

Case: A 11 yo girl with Marfan syndrome was referred to cardiac MR (CMR) to measure the size of her thoracic aorta. She had a typical phenotype with arachnodactyly, abnormally long arms, and was tall and slim (156 cm, 28 kg, body mass index 11,5 kg/m2). She complained of no symptoms. Cardiac auscultation revealed a prominent mid-systolic click and an end-systolic murmur at the apex. A recent echocardiogram showed a moderately dilated left ventricle with normal function and a mitral valve prolapse with moderate mitral valve regurgitation. CMR showed a dilatation of the aortic root (38 mm, Z-score 8.9) and a severe prolapse of the mitral valve with regurgitation. The ventricular cavity was moderately dilated (116 ml/m2) and its contraction was hyperdynamic (stroke volume (SV): 97 ml; LVEF 72%, with the LV volumes measured by modified Simpson method from the apex to the mitral annulus). In this patient however, the mitral prolapse was characterized by a severe backward movement of the valve toward the left atrium (LA) in systole and the dyskinetic movement of the atrioventricular plane caused a ventricularisation of a part of the LA in systole (Figure). This resulted in a significant reduction of LVEF: more than ¼ of the apparent SV was displaced backwards into the ventricularized LA volume, reducing the effective LVEF to 51% (effective SV 69ml). Moreover, by flow measurement, the SV across the ascending aorta was 30 ml (cardiac index 2.0 l/min/m2) allowing the calculation of a regurgitant fraction across the mitral valve of 56%, which was diagnostic for a severe mitral valve insufficiency. Conclusion: This case illustrates the phenomenon of a ventricularisation of the LA where the severe prolapse gives the illusion of a higher attachement of the mitral leaflets within the atrial wall. Besides the severe mitral regurgitation, this paradoxical backwards movement of the valve causes an intraventricular unloading during systole reducing the apparent LVEF of 72% to an effective LVEF of only 51%. In addition, forward flow fraction is only 22% after accounting for the regurgitant volume, as well. This combined involvement of the mitral valve could explain the discrepancy between a low output state and an apparently hyperdynamic LV contraction. Due to its ability to precisely measure flows and volumes, CMR is particularly suited to detect this phenomenon and to quantify its impact on the LV pump function.

Mycoplasma hominis mediastinitis after acute aortic dissection repair.

We report a case of ascending aortic graft infection by an atypical bacteria, Mycoplasma hominis, with mediastinitis, a dreaded complication after cardiac surgery. A 55-year-old patient underwent ascending aorta replacement for acute type A dissection. He developed sternal instability and purulent discharge, requiring sternal wire removal and debridement. Cultures were initially sterile, but showed M. hominis infection after a significant delay and in specific culture media. The patient was treated with doxycycline and moxifloxacine. Cultures became negative and the sternum was closed on the 28th postoperative day after the first debridement. Recovery was favorable, with no signs of infection. Antibiotics were continued for one year. The patient is still asymptomatic 16 months after antibiotic interruption. Atypical organisms should be considered in the differential diagnosis of acute mediastinitis of unknown etiology after routine microbiological investigations.

Endovascular thoracic aortic aneurysm repair without angiography.

OBJECTIVE: : Intravascular ultrasound (IVUS) generates high definition circumferential cross-sectional images and provides real-time readout of vascular dimensions, including visualization of vessel branches. We have used it as an alternative to angiography in the endovascular thoracic aneurysm repair work-up. METHODS: : Out of consecutive 203 patients with descending thoracic aortic aneurysm, 89 (43.8%) received endovascular treatment [mean age, 68 ± 8 years; range, 29-82; male, 79 (88.7%); female, 10 (11.3%)] without using angiography during the endovascular procedure. IVUS (6 F, 12.5 MHz probe or 10 F 9 MHz) coupled with fluoroscopy for the placement of radiopaque markers was used for target site identification, landing zone measurement, device positioning, and assessment of endovascular repair. RESULTS: : Hospital mortality was 4/89 (4.5%). Number of devices implanted in each patient was 1.2 (range, 1-3). X-ray exposure time was 12 ± 8 minutes. Median procedure time was 63 ± 20 minutes. Conversion to open surgery was necessary in one patient (1.1%) because of aortic dissection. In nine patients (10.1%) left subclavian artery was covered because of a short neck. Two patients (2.2%) had vascular access lesions and required surgical repair. One patient developed paraplegia (1.1%). Early endoleak was observed in eight patients (8.9%) and 4 (4.5%) required additional procedures (proximal or distal extensions). Late conversion was necessary in one patient (1.1%). CONCLUSIONS: : IVUS provides all information necessary for device selection, target site identification as well as safe and correct deployment of thoracic endoprostheses and makes periprocedural angiography unnecessary, thus avoiding the risk of renal failure because of contrast medium.