Apical closure device for full-percutaneous transapical structural and valve procedures with large-sized introducer sheaths: The final preclinical study.

BACKGROUND: Closed-chest transapical valve implantations (aortic, mitral, and tricuspid) and cardiac structural procedures requiring large-sized introducer sheaths cannot be safely performed with the available technology. We tested a self-expanding apical closure device in a closed-chest animal model, using large-sized introducer sheaths and human-sized animals to establish the technique for future tests in humans. METHODS: Six human-sized pigs (mean weight: 89.7 ± 3.7 kg) received general anesthesia, intubation, and full heparinization (15,000 IU/animal; expected activated clotting time >200 s). Under fluoroscopy and multimodality imaging guidance with next-generation fusion imaging prototypes, a 15-cm long needle and a standard guidewire were percutaneously inserted under the xiphoidal aponeurosis and into the ventricular apex. After the exchange with a stiff guidewire, a 21-Fr introducer sheath for transapical procedures (outer diameter: 25-Fr) was placed in the left ventricle through the apex. The self-expanding closure device was inserted and deployed under fluoroscopic guidance while the 21-Fr sheath was gently removed. Hemodynamic conditions were monitored for 30 min and then the chest was opened to inspect the closure device and quantify the blood loss in the pericardium. Animals were killed and the hearts were removed and inspected. RESULTS: All six apical closure devices were successfully deployed without adverse events. No death, hemodynamic collapse, or cardiac tamponade occurred during the 30-min observational period (mean systolic and diastolic pressures: 88 ± 11 and 58 ± 13 mmHg, respectively; mean heart rate: 60 ± 11 beats per minutes). Pre- and postdeployment (after protamine administration) mean activated clotting time was 541 ± 263 and 217 ± 62 s, respectively. The plugs provided good sealing with a mean of 27.2 ± 13.86 ml of blood lost in the pericardium. Postmortem inspection showed good plug fixation without myocardial damage. CONCLUSION: This self-expanding apical closure device successfully sealed the percutaneous access sites made with large-sized introducer sheaths in human-sized animals. This preclinical study suggests that transapical valve and structural procedures requiring large-sized introducer sheaths can be performed percutaneously.

Outcome of right ventricular assist device implantation following left ventricular assist device implantation: Systematic review and meta-analysis.

OBJECTIVES: The main aim was a systematic evaluation of the current evidence on outcomes for patients undergoing right ventricular assist device (RVAD) implantation following left ventricular assist device (LVAD) implantation. METHODS: This systematic review was registered on PROSPERO (CRD42019130131). Reports evaluating in-hospital as well as follow-up outcome in LVAD and LVAD/RVAD implantation were identified through Ovid Medline, Web of Science and EMBASE. The primary endpoint was mortality at the hospital stay and at follow-up. Pooled incidence of defined endpoints was calculated by using random effects models. RESULTS: A total of 35 retrospective studies that included 3260 patients were analyzed. 30 days mortality was in favour of isolated LVAD implantation 6.74% (1.98-11.5%) versus 31.9% (19.78-44.02%) p = 0.001 in LVAD with temporary need for RVAD. During the hospital stay the incidence of major bleeding was 18.7% (18.2-19.4%) versus 40.0% (36.3-48.8%) and stroke rate was 5.6% (5.4-5.8%) versus 20.9% (16.8-28.3%) and was in favour of isolated LVAD implantation. Mortality reported at short-term as well at long-term was 19.66% (CI 15.73-23.59%) and 33.90% (CI 8.84-59.96%) in LVAD respectively versus 45.35% (CI 35.31-55.4%) p ⩽ 0.001 and 48.23% (CI 16.01-80.45%) p = 0.686 in LVAD/RVAD group respectively. CONCLUSION: Implantation of a temporary RVAD is allied with a worse outcome during the primary hospitalization and at follow-up. Compared to isolated LVAD support, biventricular mechanical circulatory support leads to an elevated mortality and higher incidence of adverse events such as bleeding and stroke.

Performance characteristics of the new Eurosets magnetically suspended centrifugal pump.

OBJECTIVE: The aim was to evaluate the performance of a newly developed magnetically suspended centrifugal pump head intended for use as a ventricular assistance device with a newly developed extracorporeal membrane oxygenator setup. METHODS: In an experimental setup, an extracorporeal membrane oxygenator circuit was established in three calves with a mean weight of 68.2 ± 2.0 kg. A magnetically levitated centrifugal pump was tested, along with a newly designed extracorporeal membrane oxygenator console, at three different flow ranges: (a) 0.0 to 5.2 L/min, (b) 0.0 to 7.1 L/min, and (c) 0.0 to 6.0 L/min. For each setup, the animals were supported by a circuit for 6 h. Blood samples were collected just before caridiopulmonary bypass (CPB) after 10 min on bypass and after 1, 2, 5, and 6 h of perfusion for hemolysis determination and biochemical tests. Values were recorded for blood pressure, mean flow, and pump rotational speed. Analysis of variance was used for repeated measurements. RESULTS: Mean pump flows achieved during the three 6 h pump runs for the three pump heads studied were as follows: (a) flow range 0.0 to 5.2 L/min, 3.6 ± 1.5 L/min, (b) flow range 0.0 to 7.1 L/min, 4.9 ± 1.3 L/min, and (c) flow range 0.0 to 6.0 L/min, 3.8 ± 1.5 L/min. Blood trauma, evaluated by plasma hemoglobin and lactate dehydrogenase levels, did not help in detecting any significant hemolysis. Thrombocytes and white blood cell count profiles showed no significant differences between the groups at the end of the 6 h perfusion. At the end of testing, no clot deposition was found in the oxygenator, and there was no evidence of peripheral emboli. CONCLUSION: The results suggest that the newly developed magnetically suspended centrifugal pump head provides satisfactory hydrodynamic performance in an acute perfusion scenario without increasing hemolysis.

Effects of PDE-5 Inhibition on the Cardiopulmonary System After 2 or 4 Weeks of Chronic Hypoxia.

PURPOSE: In pulmonary hypertension (PH), hypoxia represents both an outcome and a cause of exacerbation. We addressed the question whether hypoxia adaptation might affect the mechanisms underlying PH alleviation through phosphodiesterase-5 (PDE5) inhibition. METHODS: Eight-week-old male Sprague-Dawley rats were divided into two groups depending on treatment (placebo or sildenafil, a drug inhibiting PDE5) and were exposed to hypoxia (10% O2) for 0 (t0, n = 9/10), 2 (t2, n = 5/5) or 4 (t4, n = 5/5) weeks. The rats were treated (0.3 mL i.p.) with either saline or sildenafil (1.4 mg/Kg per day). RESULTS: Two-week hypoxia changed the body weight (- 31% vs. - 27%, respectively, P = NS), blood hemoglobin (+ 25% vs. + 27%, P = NS) and nitrates+nitrites (+ 175% vs. + 261%, P = 0.007), right ventricle fibrosis (+ 814% vs. + 317%, P < 0.0001), right ventricle hypertrophy (+ 84% vs. + 49%, P = 0.007) and systolic pressure (+ 108% vs. + 41%, P = 0.001), pulmonary vessel density (+ 61% vs. + 46%, P = NS), and the frequency of small (< 50 µm wall thickness) vessels (+ 35% vs. + 13%, P = 0.0001). Most of these changes were maintained for 4-week hypoxia, except blood hemoglobin and right ventricle hypertrophy that continued increasing (+ 52% vs. + 42%, P = NS; and + 104% vs. + 83%, P = 0.04). To further assess these observations, small vessel frequency was found to be linearly related with the right ventricle-developed pressure independent of hypoxia duration. CONCLUSIONS: Thus, although hypoxia adaptation is not yet accomplished after 4 weeks, PH alleviation by PDE5 inhibition might nevertheless provide an efficient strategy for the management of this disease.

Impact of aortic root annuloplasty on 3D aortic root geometry.

BACKGROUND: The aim was to evaluate the impact of aortic root (AoR) annuloplasty on 3D AoR deformation. METHODS: In experimental setup, Yacoub procedure and Yacoub with annuloplasty were performed. Results were compared to native AoR. In each AoR modality, six microsonometric (2 mm, 200 Hz) crystals were implanted at the sinotubular junction (STJ) and at the AoR base (AoB). 3D deformation of the AoR was determined by AoR tilt (α) and rotation (ß) angle changes. RESULTS: Tilt angle in Yacoub AoR with annuloplasty and in Yacoub AoR was maximal at ejection, 26.71 ± 0.18° and 24.91 ± 0.13°, respectively, and minimal at diastole, 25.34 ± 0.15° and 21.90 ± 0.15°, respectively. Rotation angle in Yacoub AoR with and without annuloplasty was maximal at ejection, 27.04 ± 0.25° and 23.53 ± 0.54°, respectively, and minimal at diastole, 24.84 ± 0.14° and 21.62 ± 0.16°, respectively. In native AoR, tilt angle and rotation were minimal at ejection, 14.34 ± 0.81° and 18.1 ± 3.20°, respectively, and maximal at diastole, 18.78 ± 0.84° and 21.23 ± 021°, respectively. AoB and STJ had maximal expansion at ejection; 2.59 ± 2.40% and 6.05 ± 0.66 for Yacoub and 3.75 ± 0.66% and 3.08 ± 0.24% for Yacoub with annuloplasty. In native AoR, the expansion at ejection for AoB was 7.13 ± 2.68% and for STJ was 16.42 ± 0.63%. CONCLUSIONS: AoB annuloplasty reduces AoB deformation and has an impact on STJ dynamics. In both the Yacoub AoR modalities, during ejection, the AoR takes on more of a cone-like geometry, whereas in native AoR, it is of a cylinder-like shape.

New, optimized, dual-lumen cannula for veno-venous ECMO.

OBJECTIVE: The present study was designed to assess in vivo a new, optimized, virtually wall-less, dual-lumen, bi-caval cannula for veno-venous ECMO in comparison to a commercially available cannula. METHODS: Veno-venous extracorporeal membrane oxygenation (ECMO) was carried out in a bovine study (n=5, bodyweight 75±5kg). Following systemic heparinization, ECMO was established in a trans-jugular fashion through a calibrated 23F orifice, using a new, optimized, virtually wall-less, dual-lumen, bi-caval 24F cannula (Smartcanula LLC, Lausanne, Switzerland) versus a commercially available 23F bi-caval, dual-lumen control cannula (Avalon Elite®, Maquet, Rastatt, Germany) in a veno-venous ECMO setup. Veno-venous ECMO was initiated at 500 revolutions per minute (RPM) and increased by incremental steps of 500 RPM up to 2500 RPM. Catheter outlet pressure, catheter inlet pressure, oxygen saturation and pump flow were recorded at each stage. RESULTS: Mean flow accounted for 0.37±0.04 L/min for wall-less versus 0.29± 0.07 L/min for control at 500 RPM, 0.97±0.12 versus 0.67±0.06 at 1000 RPM, 1.60±0.14 versus 1.16±0.08 at 1500 RPM, 2.31±0.13 versus 1.52±0.13 for 2000 RPM and 3.02±0.5 versus 2.11±0.18 (p<0.004). The mean venous suction required was 19±8 mmHg for wall-less versus 20±3 mmHg for control at 500 RPM, 7±3 versus 9±4 for 1000 RPM, -11±10 versus -12±8 at 1500 RPM, -39±15 versus -49±10 for 2000 RPM and -60±28 versus -94±7 for 2500 RPM. The mean venous injection pressure accounted for 29±7 mmHg for wall-less versus 27±5 mmHg for control at 500 RPM, 50±6 versus 61±7 at 1000 RPM, 89±10 versus 99±17 for 1500 RPM, 142±14 versus 161±9 at 2000 RPM and 211±41 versus 252 ±3 for 2500 RPM. CONCLUSION: Compared to the commercially available control cannula, the new, optimized, virtually wall-less, dual-lumen, bi-caval 24F cannula allows for significantly higher blood flows, requires less suction and results in lower injection pressures in vivo.

Sildenafil attenuates hypoxic pulmonary remodelling by inhibiting bone marrow progenitor cells.

The recruitment of bone marrow (BM)-derived progenitor cells to the lung is related to pulmonary remodelling and the pathogenesis of pulmonary hypertension (PH). Although sildenafil is a known target in PH treatment, the underlying molecular mechanism is still elusive. To test the hypothesis that the therapeutic effect of sildenafil is linked to the reduced recruitment of BM-derived progenitor cells, we induced pulmonary remodelling in rats by two-week exposure to chronic hypoxia (CH, 10% oxygen), a trigger of BM-derived progenitor cells. Rats were treated with either placebo (saline) or sildenafil (1.4 mg/kg/day ip) during CH. Control rats were kept in room air (21% oxygen) with no treatment. As expected, sildenafil attenuated the CH-induced increase in right ventricular systolic pressure and right ventricular hypertrophy. However, sildenafil suppressed the CH-induced increase in c-kit+ cells in the adventitia of pulmonary arteries. Moreover, sildenafil reduced the number of c-kit+ cells that colocalize with tyrosine kinase receptor 2 (VEGF-R2) and CD68 (a marker for macrophages), indicating a positive effect on moderating hypoxia-induced smooth muscle cell proliferation and inflammation without affecting the pulmonary levels of hypoxia-inducible factor (HIF)-1α. Furthermore, sildenafil depressed the number of CXCR4+ cells. Collectively, these findings indicate that the improvement in pulmonary haemodynamic by sildenafil is linked to decreased recruitment of BM-derived c-kit+ cells in the pulmonary tissue. The attenuation of the recruitment of BM-derived c-kit+ cells by sildenafil may provide novel therapeutic insights into the control of pulmonary remodelling.

Long-term Outcomes of a Telementoring Program for Distant Teaching of Endovascular Aneurysm Repair.

PURPOSE: To prospectively evaluate the long-term outcomes after a telementoring program for distant teaching of endovascular aneurysm repair (EVAR) and the degree of EVAR procedure assimilation into routine practice. METHODS: A telementoring protocol using stepwise introduction of EVAR was implemented between a university care center and a remote vascular health care site; from March 1999 to October 2003, 49 EVAR patients (mean age 72 years; 48 men) were treated during telementoring at the remote center. After the telementoring period, 86 patients (mean age 71 years; 77 men) underwent EVAR procedures carried out at the secondary care center from November 2003 to July 2011. The long-term outcomes were compared between the EVAR procedures performed during telementoring with the procedures performed independently thereafter. RESULTS: No significant difference was appreciated between telementored and not telementored procedures either in 30-day mortality (4.1% vs 2.3%, p=0.621) or in the initial technical success (93.9% vs 97.7%, p=0.353). The telementored group showed no significant difference in overall aneurysm-related mortality (6.1% vs 2.3%, p=0.353) or in the overall complication rates (p=0.985). The reintervention rate was significantly lower among the unmentored procedures (11.6% vs 32.7%, p=0.004). In particular, significantly fewer patients underwent late endovascular procedures (1.2% vs 12.2%, p=0.009) and late percutaneous interventions (7.0% vs 20.4%, p=0.027) after telementoring ceased. CONCLUSION: The telementoring program followed here allowed excellent EVAR skill assimilation into the routine practice of a remote health care site. Telementoring is a feasible strategy to support skill introduction in remote medical facilities.

Analysis of flow dynamics in right ventricular outflow tract.

BACKGROUND: The mechanism behind early graft failure after right ventricular outflow tract (RVOT) reconstruction is not fully understood. Our aim was to establish a three-dimensional computational fluid dynamics (CFD) model of RVOT to investigate the hemodynamic conditions that may trigger the development of intimal hyperplasia and arteriosclerosis. METHODS: Pressure, flow, and diameter at the RVOT, pulmonary artery (PA), bifurcation of the PA, and left and right PAs were measured in 10 normal pigs with a mean weight of 24.8 ± 0.78 kg. Data obtained from the experimental scenario were used for CFD simulation of pressure, flow, and shear stress profile from the RVOT to the left and right PAs. RESULTS: Using experimental data, a CFD model was obtained for 2.0 and 2.5-L/min pulsatile inflow profiles. In both velocity profiles, time and space averaged in the low-shear stress profile range from 0-6.0 Pa at the pulmonary trunk, its bifurcation, and at the openings of both PAs. These low-shear stress areas were accompanied to high-pressure regions 14.0-20.0 mm Hg (1866.2-2666 Pa). Flow analysis revealed a turbulent flow at the PA bifurcation and ostia of both PAs. CONCLUSIONS: Identified local low-shear stress, high pressure, and turbulent flow correspond to a well-defined trigger pattern for the development of intimal hyperplasia and arteriosclerosis. As such, this real-time three-dimensional CFD model may in the future serve as a tool for the planning of RVOT reconstruction, its analysis, and prediction of outcome.

Long-term outcome of congenital aortic valve stenosis: predictors of reintervention.

OBJECTIVES: To evaluate long-term outcome of initial aortic valve intervention in a paediatric population with congenital aortic stenosis, and to determine risk factors associated with reintervention. PATIENTS AND METHODS: From 1985 to 2009, 77 patients with congenital aortic stenosis and a mean age of 5.8±5.6 years at diagnosis were followed up in our institution for 14.8±9.1 years. RESULTS: First intervention was successful with 86% of patients having a residual peak aortic gradient 1 regurgitation increased by 7%. Long-term survival after the first procedure was excellent, with 91% survival at 25 years. At a mean interval of 7.6±5.3 years, 30 patients required a reintervention (39%), mainly because of a recurrent aortic stenosis. Freedom from reintervention was 97, 89, 75, 53, and 42% at 1, 10, 15, 20, and 25 years, respectively. Predictors of reintervention were residual peak aortic gradient (p=0.0001), aortic regurgitation post-intervention >1 (p=0.02), prior balloon aortic valvuloplasty (p=0.04), and increased left ventricular posterior wall thickness (p=0.1). CONCLUSIONS: Aortic valve intervention is a safe and effective procedure for congenital aortic stenosis with excellent survival results. However, rate of reintervention is high and influenced by increased left ventricular posterior wall thickness pre-intervention, prior balloon valvuloplasty, higher residual peak systolic valve gradient, and more than mild regurgitation post-intervention. The study highlights that long-term follow-up is recommended for these patients.

Endovascular abdominal aneurysm repair and impact of systematic preoperative embolization of collateral arteries: endoleak analysis and long-term follow-up.

PURPOSE: To report our results of endovascular aneurysm repair (EVAR) over a 10-year period using systematic preoperative collateral artery embolization. METHODS: From 1999 until 2009, 124 patients (117 men; mean age 70.8 years) with abdominal aortic aneurysm (AAA) underwent embolization of patent lumbar and/or inferior mesenteric arteries prior to elective EVAR procedures. Embolization was systematically attempted and, whenever possible, performed using microcoils and a coaxial technique. Follow-up included computed tomography and/or magnetic resonance imaging and abdominal radiography. RESULTS: The technical success for EVAR was 96% (119/124), with 4 patients dying within 30 days (3.2% perioperative mortality) and 1 type III endoleak accounting for the failures. Collateral arteries were occluded spontaneously or by embolization in 60 (48%) of 124 patients. The endoleak rate was 50.9% (74 in 61 patients), most of which were type II (19%). Over a mean clinical follow-up of 60.5±34.1 months (range 1-144), aneurysm sac dimensions decreased in 66 patients, increased in 19 patients, and were stable in 35. The endoleak rate was significantly higher in the patients with increasing sac diameter (p<0.001). Among the patients with patent collateral arteries, 38/64 (59.3%) developed 46 leaks, while 28 leaks appeared in 23 (41%) of 56 patients with collateral artery occlusion (p=0.069). The type II endoleak rate significantly differed between these two groups (47.8% vs. 3.6%, p<0.001). CONCLUSION: Preoperative collateral embolization seems to be a valid method of reducing the incidence of type II endoleak, improving the long-term outcome.

Prevention and management of potential adverse events during transapical aortic valve replacement.

BACKGROUND AND AIM OF THE STUDY: Transapical transcatheter aortic valve replacement (TAVR) is a new minimally invasive technique with a known risk of unexpected intra-procedural complications. Nevertheless, the clinical results are good and the limited amount of procedural adverse events confirms the usefulness of a synergistic surgical/anesthesiological management in case of unexpected emergencies. METHODS: A review was made of the authors' four-year database and other available literature to identify major and minor intra-procedural complications occurring during transapical TAVR procedures. All implants were performed under general anesthesia with a balloon-expandable Edwards Sapien stent-valve, and followed international guidelines on indications and techniques. RESULTS: Procedural success rates ranged between 94% and 100%. Life-threatening apical bleeding occurred very rarely (0-5%), and its incidence decreased after the first series of implants. Stent-valve embolization was also rare, with a global incidence ranging from 0-2%, with evidence of improvement after the learning curve. Rates of valve malpositioning ranged from 0% to < 3%, whereas the risk of coronary obstruction ranged from 0% to 3.5%. Aortic root rupture and dissection were dramatic events reported in 0-2% of transapical cases. Stent-valve malfunction was rarely reported (1-2%), whereas the valve-in-valve bailout procedure for malpositioning, malfunctioning or severe paravalvular leak was reported in about 1.0-3.5% of cases. Sudden hemodynamic management and bailout procedures such as valve-in-valve rescue or cannulation for cardiopulmonary bypass were more effective when planned during the preoperative phase. CONCLUSION: Despite attempts to avoid pitfalls, complications during transapical aortic valve procedures still occur. Preoperative strategic planning, including hemodynamic status management, alternative cannulation sites and bailout procedures, are highly recommended, particularly during the learning curve of this technique.

Influence of deep sternal wound infection on long-term survival after cardiac surgery.

BACKGROUND: This study aimed to investigate the influence of deep sternal wound infection on long-term survival following cardiac surgery. MATERIAL AND METHODS: In our institutional database we retrospectively evaluated medical records of 4732 adult patients who received open-heart surgery from January 1995 through December 2005. The predictive factors for DSWI were determined using logistic regression analysis. Then, each patient with deep sternal wound infection (DSWI) was matched with 2 controls without DSWI, according to the risk factors identified previously. After checking balance resulting from matching, short-term mortality was compared between groups using a paired test, and long-term survival was compared using Kaplan-Meier analysis and a Cox proportional hazard model. RESULTS: Overall, 4732 records were analyzed. The mean age of the investigated population was 69.3±12.8 years. DSWI occurred in 74 (1.56%) patients. Significant independent predictive factors for deep sternal infections were active smoking (OR 2.19, CI95 1.35-3.53, p=0.001), obesity (OR 1.96, CI95 1.20-3.21, p=0.007), and insulin-dependent diabetes mellitus (OR 2.09, CI95 1.05-10.06, p=0.016). Mean follow-up in the matched set was 125 months, IQR 99-162. After matching, in-hospital mortality was higher in the DSWI group (8.1% vs. 2.7% p=0.03), but DSWI was not an independent predictor of long-term survival (adjusted HR 1.5, CI95 0.7-3.2, p=0.33). CONCLUSIONS: The results presented in this report clearly show that post-sternotomy deep wound infection does not influence long-term survival in an adult general cardio-surgical patient population.

Late migration of percutaneous bio-absorbable devices--a word of caution.

BACKGROUND: Closures of atrial septal defects or a patent foramen ovale (PFO) are increasingly performed percutaneously. The experience of late migration of a new bio-absorbable device is presented here, followed by conceptual discussion. METHODS: Six months post PFO closure with a BioSTAR® device a patient presented with chest pain. Echocardiography showed a hyperechogenic structure perforating the aortic wall. RESULTS: Surgical exploration showed a perforation of the ascending aorta by one metallic, non absorbable arm. This is the second case of late (>6 months) dislocation of the residual framework of the occluder. CONCLUSIONS: The overall incidence of perforation of cardiac structures due to secondary dislocation is low. However this complication exists and should kept in mind in symptomatic patients with new onset of chest pain, after percutaneous procedures. The concept of biodegradation, with residual, non absorbable metal braiding, should be reviewed, analyzing in particular long term results and incidence of secondary dislocation.

Myxoma on a mechanical mitral valve annulus.

To date, myxoma on a mechanical valve annulus has not been reported. The case is reported of a 74-year-old woman who was admitted to hospital following the identification of an intracardiac tumor mass. Six years previously, the patient had received a mechanical valve implanted in the mitral position. Transesophageal echocardiography revealed a mobile hypoechogenic tumorous mass attached to the anterior annulus of the prosthesis. The tumor was successfully treated by surgical excision, and a diagnosis of myxoma was confirmed both clinically and pathologically.

New prototype of femoral arterial SmartCannula with anterograde and retrograde flow.

OBJECTIVES: Femoral artery cannulation is routinely used in circulatory support scenarios for cardiorespiratory support in patients with acute cardiac and/or pulmonary decompensation. During prolonged perfusion, this may cause acute ischemia of the leg and, in the worst case, even amputation. The aim of this experimental study was to test a newly designed arterial cannula allowing proximal and distal blood flow. METHODS: Veno-arterial cardiopulmonary bypass was established in three calves (67.6 ± 5.1 kg). The venous line was secured by cannulation of the external jugular vein. The arterial line of each animal was secured by cannulation of iliac arteries on both legs. On one side, we used a modified SmartCannula (SmartCannula 18Fr 130 mm) and, on the other side, a standard rectilinear BioMedicus cannula system was used, 19 Fr for retrograde and an 8 Fr BioMedicus shunt for anterograde flow toward the leg. An ultrasonic flow probe was used to quantify the perfusion of the distal leg. RESULTS: At 0.5, 1.0, 1.5, and 2.0 l/min, the anterograde leg blood flow increased steadily for each cannula, but remained higher in the self-expanding cannula. That is, the 8 F rectilinear cannula achieved a blood flow of 0.02 ± 0.01, 0.1 ± 0.04, 0.22 ± 0.09, and 0.21 ± 0.02 l/min, respectively, and the 18 F self-expanding cannula achieved 0.06 ± 0.02, 0.15 ± 0.03, 0.24 ± 0.07 and 0.36 ± 0.04 l/min. CONCLUSION: The modified self-expanding cannula exhibited superior distal arterial flow compared to the routinely used rectilinear shunt system. This has a potential to reduce ischemic events of the inferior extremity in prolonged perfusion.

Congenital giant aneurysm of the left coronary artery.

We report an unusual case of congenital giant coronary aneurysm. A 23 year-old male with a history of acute myocardial infarction presented an abnormal shadow in the left cardiac border on routine X-ray. Electrocardiogram and physical examination were normal without any clinical signs of inflammation, but computed tomography (CT) scan and cardiac magnetic resonance imaging (MRI) revealed a giant (>50mm) coronary aneurysm. Coronary artery bypass grafting (CABG) with coronary artery aneurysm (CAA) resection resolved the CAA. Coronary artery aneurysms are entities of localised dilation and can be common events in chronic infectious disease as a result of the systemic inflammatory state; however, giant coronary aneurysms (measuring more than 50mm) are rare. This is especially true where the pathological aetiology was not clearly defined or was believed to be of congenital origin. To date only a few published case reports exist for this type of pathological entity.

Clinical review: practical recommendations on the management of perioperative heart failure in cardiac surgery.

Acute cardiovascular dysfunction occurs perioperatively in more than 20% of cardiosurgical patients, yet current acute heart failure (HF) classification is not applicable to this period. Indicators of major perioperative risk include unstable coronary syndromes, decompensated HF, significant arrhythmias and valvular disease. Clinical risk factors include history of heart disease, compensated HF, cerebrovascular disease, presence of diabetes mellitus, renal insufficiency and high-risk surgery. EuroSCORE reliably predicts perioperative cardiovascular alteration in patients aged less than 80 years. Preoperative B-type natriuretic peptide level is an additional risk stratification factor. Aggressively preserving heart function during cardiosurgery is a major goal. Volatile anaesthetics and levosimendan seem to be promising cardioprotective agents, but large trials are still needed to assess the best cardioprotective agent(s) and optimal protocol(s). The aim of monitoring is early detection and assessment of mechanisms of perioperative cardiovascular dysfunction. Ideally, volume status should be assessed by 'dynamic' measurement of haemodynamic parameters. Assess heart function first by echocardiography, then using a pulmonary artery catheter (especially in right heart dysfunction). If volaemia and heart function are in the normal range, cardiovascular dysfunction is very likely related to vascular dysfunction. In treating myocardial dysfunction, consider the following options, either alone or in combination: low-to-moderate doses of dobutamine and epinephrine, milrinone or levosimendan. In vasoplegia-induced hypotension, use norepinephrine to maintain adequate perfusion pressure. Exclude hypovolaemia in patients under vasopressors, through repeated volume assessments. Optimal perioperative use of inotropes/vasopressors in cardiosurgery remains controversial, and further large multinational studies are needed. Cardiosurgical perioperative classification of cardiac impairment should be based on time of occurrence (precardiotomy, failure to wean, postcardiotomy) and haemodynamic severity of the patient's condition (crash and burn, deteriorating fast, stable but inotrope dependent). In heart dysfunction with suspected coronary hypoperfusion, an intra-aortic balloon pump is highly recommended. A ventricular assist device should be considered before end organ dysfunction becomes evident. Extra-corporeal membrane oxygenation is an elegant solution as a bridge to recovery and/or decision making. This paper offers practical recommendations for management of perioperative HF in cardiosurgery based on European experts' opinion. It also emphasizes the need for large surveys and studies to assess the optimal way to manage perioperative HF in cardiac surgery.

Superior venous drainage in the "LifeBox": a portable extracorporeal oxygenator with a self-expanding venous cannula.

BACKGROUND: In an experimental setting, the performance of the LifeBox, a new portable extracorporeal membrane oxygenator (ECMO) system suitable for patient transport, is presented. Standard rectilinear percutaneous cannulae are normally employed for this purpose, but have limited flow and pressure delivery due to their rigid structure. Therefore, we aimed to determine the potential for flow increase by using self-expanding venous cannulae. METHODS: Veno-arterial bypass was established in three pigs (40.6+/-5.1 kg). The venous line of the cardiopulmonary bypass was established by cannulation of the external jugular vein. The arterial side of the circulation was secured by cannulation of the common carotid artery. Two different venous cannulae (SmartCanula 18/36F 430mm and Biomedicus 19F) were examined for their functional integrity when used in conjunction with the centrifugal pump (500-3000 RPM) of the LifeBox system. RESULTS: At 1500, 2000, 2500, and 3000 RPM, the blood flow increased steadily for each cannula, but remained higher in the self-expanding cannula. That is, the 19F rectilinear cannula achieved a blood flow of 0.93+/-0.14, 1.47+/-0.37, 1.9+/-0.68, and 1.5+/-0.9 l/min, respectively, and the 18/36F self-expanding cannula achieved 1.1+/-0.1, 1.9+/-0.33, 2.8+/-0.39 and 3.66+/-0.52 l/min. However, when tested for venous line pressure, the standard venous cannula achieved -29+/-10.7mmHg while the self-expanding cannula achieved -13.6 +/-4.3mmHg at 1500 RMP. As the RPM increased from 2500 to 3000, the venous line pressure accounted for -141.9+/-20 and -98+/-7.3mmHg for the 19F rectilinear cannula and -30.6+/-6.4 and -45+/-11.6mmHg for the self-expanding cannula. CONCLUSION: The self-expanding cannula exhibited superior venous drainage ability when compared to the performance of the standard rectilinear cannula with the use of the LifeBox. The flow rate achieved was approximately 40% greater than the standard drainage device, with a maximal pump flow recorded at 4.3l/min.