New Self-Expanding Transcatheter Valve for Off-Pump Transatrial Mitral Valve-In-Ring Implantation.

OBJECTIVES To validate a self-expanding transcatheter valve for off-pump transatrial mitral valve-in-ring (VIR) implantation via a left thoracotomy. METHODS Mitral valve annuloplasty was performed via sternotomy during cardiopulmonary bypass on 9 pigs. After successful weaning from extracorporal circulation, the custom-made, self-expanding transcatheter VIR device was deployed under fluoroscopic guidance within the annuloplasty ring via a left thoracotomy. Hemodynamic data before and after the implantation were recorded. Mitral annulus diameter and valve area were measured by echocardiography. Transvalvular and left-ventricular outflow-tract pressure gradient were measured invasively. RESULTS Eight successful implantations were performed. Implantation failed in 1 pig because of difficulty with technical delivery of the sheath. Mean transatrial procedure time was 12.6 ± 1.7 min. Hemodynamic status during transatrial implantation was stable, and differences were not statistically significant. Mean mitral annulus diameter and mean mitral orifice area were 2.32 ± 0.2 and 3.84 ± 0.55 cm2, respectively. Mild regurgitation was detected in 7 animals and moderate regurgitation in 1. Mean gradients were 6.1 ± 5.0 mm Hg across the device. Postmortem examination confirmed adequate positioning of devices within the annuloplasty ring. CONCLUSIONS This custom-made transcatheter device allows for safe and reproducible off-pump transatrial mitral VIR implantations. Transatrial access is a promising route to facilitate VIR implantations. Our custom-made stent-valve may be suitable for VIR procedures.

Clinical and haemodynamic outcomes in 658 patients receiving the Perceval sutureless aortic valve: early results from a prospective European multicentre study (the Cavalier Trial)†.

OBJECTIVES The aim of the Cavalier trial was to evaluate the safety and performance of the Perceval sutureless aortic valve in patients undergoing aortic valve replacement (AVR). We report the 30-day clinical and haemodynamic outcomes from the largest study cohort with a sutureless valve. METHODS From February 2010 to September 2013, 658 consecutive patients (mean age 77.8 years; 64.4% females; mean logistic EuroSCORE 10.2%) underwent AVR in 25 European Centres. Isolated AVRs were performed in 451 (68.5%) patients with a less invasive approach in 219 (33.3%) cases. Of the total, 40.0% were octogenarians. Congenital bicuspid aortic valve was considered an exclusion criterion. RESULTS Implantation was successful in 628 patients (95.4%). In isolated AVR through sternotomy, the mean cross-clamp time and the cardiopulmonary bypass (CPB) time were 32.6 and 53.7 min, and with the less invasive approach 38.8 and 64.5 min, respectively. The 30-day overall and valve-related mortality rates were 3.7 and 0.5%, respectively. Valve explants, stroke and endocarditis occurred in 0.6, 2.1 and in 0.1% of cases, respectively. Preoperative mean and peak pressure gradients decreased from 44.8 and 73.24 mmHg to 10.24 and 19.27 mmHg at discharge, respectively. The mean effective orifice area improved from 0.72 to 1.46 cm(2). CONCLUSIONS The current 30-day results show that the Perceval valve is safe (favourable haemodynamic effect and low complication rate), and can be implanted with a fast and reproducible technique after a short learning period. Short cross-clamp and CPB times were achieved in both isolated and combined procedures. The Perceval valve represents a promising alternative to biological AVR, especially with a less invasive approach and in older patients.

Sutureless Aortic Valve Replacement International Registry (SU-AVR-IR): design and rationale from the International Valvular Surgery Study Group (IVSSG).

BACKGROUND Sutureless aortic valve replacement (SU-AVR) is an innovative approach which shortens cardiopulmonary bypass and cross-clamp durations and may facilitate minimally invasive approach. Evidence outlining its safety, efficacy, hemodynamic profile and potential complications is replete with small-volume observational studies and few comparative publications. METHODS Minimally invasive aortic valve surgery and high-volume SU-AVR replacement centers were contacted for recruitment into a global collaborative coalition dedicated to sutureless valve research. A Research Steering Committee was formulated to direct research and support the mission of providing registry evidence warranted for SU-AVR. RESULTS The International Valvular Surgery Study Group (IVSSG) was formed under the auspices of the Research Steering Committee, comprised of 36 expert valvular surgeons from 27 major centers across the globe. IVSSG Sutureless Projects currently proceeding include the Retrospective and Prospective Phases of the SU-AVR International Registry (SU-AVR-IR). CONCLUSIONS The global pooling of data by the IVSSG Sutureless Projects will provide required robust clinical evidence on the safety, efficacy and hemodynamic outcomes of SU-AVR.

Sutureless aortic valve replacement: a systematic review and meta-analysis.

BACKGROUND Sutureless aortic valve replacement (SU-AVR) has emerged as an innovative alternative for treatment of aortic stenosis. By avoiding the placement of sutures, this approach aims to reduce cross-clamp and cardiopulmonary bypass (CPB) duration and thereby improve surgical outcomes and facilitate a minimally invasive approach suitable for higher risk patients. The present systematic review and meta-analysis aims to assess the safety and efficacy of SU-AVR approach in the current literature. METHODS Electronic searches were performed using six databases from their inception to January 2014. Relevant studies utilizing sutureless valves for aortic valve implantation were identified. Data were extracted and analyzed according to predefined clinical endpoints. RESULTS Twelve studies were identified for inclusion of qualitative and quantitative analyses, all of which were observational reports. The minimally invasive approach was used in 40.4% of included patients, while 22.8% underwent concomitant coronary bypass surgery. Pooled cross-clamp and CPB duration for isolated AVR was 56.7 and 46.5 minutes, respectively. Pooled 30-day and 1-year mortality rates were 2.1% and 4.9%, respectively, while the incidences of strokes (1.5%), valve degenerations (0.4%) and paravalvular leaks (PVL) (3.0%) were acceptable. CONCLUSIONS The evaluation of current observational evidence suggests that sutureless aortic valve implantation is a safe procedure associated with shorter cross-clamp and CPB duration, and comparable complication rates to the conventional approach in the short-term.

Development of post-pump syndrome in a sheep after mitral valve stenting

A one-year-old healthy sheep received an implant stenting the mural ('posterior') leaflet of the mitral valve. The experiment was authorized by the Cantonal Ethical Committee. The surgery was performed on the open, beating heart during cardiopulmonary bypass (CPB). Management of anaesthesia was based on isoflurane with mechanical intermittent positive pressure ventilation (IPPV) of the lungs, combined with intercostal nerve blocks and intravenous fentanyl and lidocaine. Marked cardiovascular depression occurred towards the end of CPB time and required high doses of dopamine, dobutamine, lidocaine and ephedrine to allow for weaning off the CPB pump. Moreover, severe pulmonary dysfunction developed when IPPV was re-initiated after CPB. Hypoxaemia persisted throughout the recovery from general anaesthesia. Multiple organ failure developed gradually during the three postoperative days, leading to euthanasia of the animal. As described in this case, marked lung injury associated with some degree of failure of other vital organs may occur in sheep after CPB. Intraoperative cardiorespiratory complications when weaning-off may indicate the development of 'post-pump syndrome'.

European multicentre experience with the sutureless Perceval valve: clinical and haemodynamic outcomes up to 5 years in over 700 patients†.

OBJECTIVES This report summarizes the 5-year clinical and haemodynamic data from three prospective, European multicentre trials with the Perceval sutureless aortic valve. METHODS From April 2007 to August 2012, 731 consecutive patients (mean age: 78.5 years; 68.1% females; mean logistic EuroSCORE 10.9%) underwent AVR with the Perceval valve in 25 European centres. Isolated AVR was performed in 498 (68.1%) patients. A minimally invasive approach was performed in 189 (25.9%) cases. The cumulative follow-up was 729 patients-years. RESULTS In isolated AVR, mean cross-clamp and cardiopulmonary bypass times were 30.8 and 50.8 min in full sternotomy, and 37.6 and 64.4 min in the minimally invasive approach, respectively. Early cardiac-related deaths occurred in 1.9%. Overall survival rates at 1 and 5 years were 92.1 and 74.7%, respectively. Major paravalvular leak occurred in 1.4% and 1% at early and late follow-up, respectively. Significant improvement in clinical status was observed postoperatively in the majority of patients. Mean and peak gradients decreased from 42.9 and 74.0 mmHg preoperatively, to 7.8 and 16 mmHg at the 3-year follow-up. LV mass decreased from 254.5 to 177.4 g at 3 years. CONCLUSIONS This European multicentre experience, with the largest cohort of patients with sutureless valves to date, shows excellent clinical and haemodynamic results that remain stable even up to the 5-year follow-up. Even in this elderly patient cohort with 40% octogenarians, both early and late mortality rates were very low. There were no valve migrations, structural valve degeneration or valve thrombosis in the follow-up. The sutureless technique is a promising alternative to biological aortic valve replacement.

Use of minimal invasive extracorporeal circulation in cardiac surgery: principles, definitions and potential benefits. A position paper from the Minimal invasive Extra-Corporeal Technologies international Society (MiECTiS).

Minimal invasive extracorporeal circulation (MiECC) systems have initiated important efforts within science and technology to further improve the biocompatibility of cardiopulmonary bypass components to minimize the adverse effects and improve end-organ protection. The Minimal invasive Extra-Corporeal Technologies international Society was founded to create an international forum for the exchange of ideas on clinical application and research of minimal invasive extracorporeal circulation technology. The present work is a consensus document developed to standardize the terminology and the definition of minimal invasive extracorporeal circulation technology as well as to provide recommendations for the clinical practice. The goal of this manuscript is to promote the use of MiECC systems into clinical practice as a multidisciplinary strategy involving cardiac surgeons, anaesthesiologists and perfusionists.

Minimal invasive extracorporeal circulation should become the standard practice in coronary revascularization surgery†.

We read with great interest the large-scale network meta-analysis by Kowalewski et al. comparing clinical outcomes of patients undergoing coronary artery bypass grafting (CABG) operated on using minimal invasive extracorporeal circulation (MiECC) or off-pump (OPCAB) with those undergoing surgery on conventional cardiopulmonary bypass (CPB) [1]. The authors actually integrated into single study two recently published meta-analysis comparing MiECC and OPCAB with conventional CPB, respectively [2, 3] into a single study. According to the results of this study, MiECC and OPCAB are both strongly associated with improved perioperative outcomes following CABG when compared with CABG performed on conventional CPB. The authors conclude that MiECC may represent an attractive compromise between OPCAB and conventional CPB. After carefully reading the whole manuscript, it becomes evident that the role of MiECC is clearly undervalued. Detailed statistical analysis using the surface under the cumulative ranking probabilities indicated that MiECC represented the safer and more effective intervention regarding all-cause mortality and protection from myocardial infarction, cerebral stroke, postoperative atrial fibrillation and renal dysfunction when compared with OPCAB. Even though no significant statistical differences were demonstrated between MiECC and OPCAB, the superiority of MiECC is obvious by the hierarchy of treatments in the probability analysis, which ranked MiECC as the first treatment followed by OPCAB and conventional CPB. Thus, MiECC does not represent a compromise between OPCAB and conventional CPB, but an attractive dominant technique in CABG surgery. These results are consistent with the largest published meta-analysis by Anastasiadis et al. comparing MiECC versus conventional CPB including a total of 2770 patients. A significant decrease in mortality was observed when MiECC was used, which was also associated with reduced risk of postoperative myocardial infarction and neurological events [4]. Similarly, another recent meta-analysis by Benedetto et al. compared MiECC versus OPCAB and resulted in comparable outcomes between these two surgical techniques [5]. As stated in the text, superiority of MiECC observed in the current network meta-analysis, when compared with OPCAB, could be attributed to the fact that MiECC offers the potential for complete revascularization, whereas OPCAB poses a challenge for unexperienced surgeons; especially when distal marginal branches on the lateral and/or posterior wall of the heart need revascularization. This is reflected by a significantly lower number of distal anastomoses performed in OPCAB when compared with conventional CPB. Therefore, taking into consideration the literature published up to date, including the results of the current article, we advocate that MiECC should be integrated in the clinical practice guidelines as a state-of-the-art technique and become a standard practice for perfusion in coronary revascularization surgery.

Minimally invasive extracorporeal circulation resuscitation in hypothermic cardiac arrest.

Current guidelines for the treatment of hypothermic cardiocirculatory arrest recommend extracorporeal life support and rewarming, using cardiopulmonary bypass or extracorporeal membrane oxygenation circuits. Both have design-related shortcomings which may result in prolonged reperfusion time or insufficient oxygen delivery to vital organs. This article describes clear advantages of minimally invasive extracorporeal circulation systems during emergency extracorporeal life support in hypothermic arrest. The technique of minimally invasive extracorporeal circulation for reperfusion and rewarming is represented by the case of a 59-year-old patient in hypothermic cardiocirculatory arrest at 25.3°C core temperature, with multiple trauma. With femoro-femoral cannulation performed under sonographic and echocardiographic guidance, extracorporeal life support was initiated using a minimally invasive extracorporeal circulation system. Perfusing rhythm was restored at 28°C. During rewarming on the mobile circuit, trauma surveys were completed and the treatment initiated. Normothermic weaning was successful on the first attempt, trauma surgery was completed and the patient survived neurologically intact. For extracorporeal resuscitation from hypothermic arrest, minimally invasive extracorporeal circulation offers all the advantages of conventional cardiopulmonary bypass and extracorporeal membrane oxygenation systems without their shortcomings.

Study of length of stay in the cardiovascular intensive care unit

Coronary artery bypass graft (CABG) surgery is among the most common operations performed in the United States and accounts for more resources expended in cardiovascular medicine than any other single procedure. CABG surgery patients initially recover in the Cardiovascular Intensive Care Unit (CVICU). The post-procedure CVICU length of stay (LOS) goal is two days or less. A longer ICU LOS is associated with a prolonged hospital LOS, poor health outcomes, greater use of limited resources, and increased medical costs. ^ Research has shown that experienced clinicians can predict LOS no better than chance. Current CABG surgery LOS risk models differ greatly in generalizability and ease of use in the clinical setting. A predictive model that identified modifiable pre- and intra-operative risk factors for CVICU LOS greater than two days could have major public health implications as modification of these identified factors could decrease CVICU LOS and potentially minimize morbidity and mortality, optimize use of limited health care resources, and decrease medical costs. ^ The primary aim of this study was to identify modifiable pre-and intra-operative predictors of CVICU LOS greater than two days for CABG surgery patients with cardiopulmonary bypass (CPB). A secondary aim was to build a probability equation for CVICU LOS greater than two days. Data were extracted from 416 medical records of CABG surgery patients with CPB, 50 to 80 years of age, recovered in the CVICU of a large teaching, referral hospital in southeastern Texas, during the calendar year 2004 and the first quarter of 2005. Exclusion criteria included Diagnosis Related Group (DRG) 106, CABG surgery without CPB, CABG surgery with other procedures, and operative deaths. The data were analyzed using multivariate logistic regression for an alpha=0.05, power=0.80, and correlation=0.26. ^ This study found age, history of peripheral arterial disease, and total operative time equal to and greater than four hours to be independent predictors of CVICU LOS greater than two days. The probability of CVICU LOS greater than two days can be calculated by the following equation: -2.872941 +.0323081 (age in years) + .8177223 (history of peripheral arterial disease) + .70379 (operative time). ^

Quality assurance of paediatric cardiac surgery: A prospective 6-year analysis

Objective: To audit effective quality assurance methods to monitor outcomes following paediatric cardiac surgery at a single institution. Methods: All patients undergoing cardiac surgery from January 1996 to December 2001 were enrolled prospectively. Patients were stratified by complexity of surgical procedure into four groups, with Category 4 being the most complex procedure. Outcome measures included death, length of admission and morbidity from complications. Results: A total of 1815 patients underwent 1973 surgical procedures. Of these, 1447 (73.3%) were cardiopulmonary bypass procedures, and 543 (27.5%) were more complex (Category 3 and 4) procedures. Median patient age was 3.5 years (range, 1 day-20 years) and patient weight 15.0 kg (range, 900 g to 90 kg). Sixty-six patients (3.6%) died during the study period. Of the procedures in 1996, 22.7% were classified as complex compared with 29.2% of procedures in 2001. The annual surgical mortality ranged from 1.9-4.7% (P=0.20), and when mortality was adjusted for complexity of surgery, there was no significant yearly variation in the mortality rate (P=0.57). Analysis of individual surgeon's results showed no significant difference in the mortality rate by complexity of surgery performed (P=0.90). Mean ventilation times did not change significantly over time (P=0.79). The yearly incidence of significant neurological complications ranged from 0.6% to 4.5% and the incidence of arrhythmias from 4.2% to 8.0%. No difference was detected between the years. Conclusions: Stratifying complexity of surgery proved valuable in monitoring surgical outcomes and detecting differences in performance over time as large subgroups were created for analysis.

Applications of transcranial Doppler in the ICU: a review

Objective: Transcranial Doppler (TCD) ultrasonography is a technique that uses a hand-held Doppler transducer (placed on the surface of the cranial skin) to measure the velocity and pulsatility of blood flow within the intracranial and the extracranial arteries. This review critically evaluates the evidence for the use of TCD in the critical care population. Discussion: TCD has been frequently employed for the clinical evaluation of cerebral vasospasm following subarachnoid haemorrhage (SAH). To a lesser degree, TCD has also been used to evaluate cerebral autoregulatory capacity, monitor cerebral circulation during cardiopulmonary bypass and carotid endarterectomies and to diagnose brain death. Technological advances such as M mode, colour Doppler and three-dimensional power Doppler ultrasonography have extended the scope of TCD to include other non-critical care applications including assessment of cerebral emboli, functional TCD and the management of sickle cell disease. Conclusions: Despite publications suggesting concordance between TCD velocity measurements and cerebral blood flow there are few randomized controlled studies demonstrating an improved outcome with the use of TCD monitoring in neurocritical care. Newer developments in this technology include venous Doppler, functional Doppler and use of ultrasound contrast agents.

Assessment of statistical change criteria used to define significant change in neuropsychological test performance following cardiac surgery

Objective: This paper compares four techniques used to assess change in neuropsychological test scores before and after coronary artery bypass graft surgery (CABG), and includes a rationale for the classification of a patient as overall impaired. Methods: A total of 55 patients were tested before and after surgery on the MicroCog neuropsychological test battery. A matched control group underwent the same testing regime to generate test–retest reliabilities and practice effects. Two techniques designed to assess statistical change were used: the Reliable Change Index (RCI), modified for practice, and the Standardised Regression-based (SRB) technique. These were compared against two fixed cutoff techniques (standard deviation and 20% change methods). Results: The incidence of decline across test scores varied markedly depending on which technique was used to describe change. The SRB method identified more patients as declined on most measures. In comparison, the two fixed cutoff techniques displayed relatively reduced sensitivity in the detection of change. Conclusions: Overall change in an individual can be described provided the investigators choose a rational cutoff based on likely spread of scores due to chance. A cutoff value of ≥20% of test scores used provided acceptable probability based on the number of tests commonly encountered. Investigators must also choose a test battery that minimises shared variance among test scores.

Failure of normal glycaemic regulation in a patient with severe hypothermia

This report describes the case of an 88-year-old non-diabetic female who presented to the emergency department following a presumed hypoijtycaemic collapse due to self-neglect. Subsequent rewarming and resuscitation demonstrated a number of the significant consequences of severe hypothermia, including apparent secondary impairment of glycaemic autoregulation. The phenomenon of reversible inhibition of insulin secretion due to severe hypothermia has been documented previously in the field of cardiac surgery. The hyperglycaemia was not treated with any antihyperglycaernic agent, and her recovery was uneventful. Subsequent blood sugar level monitoring was normal. If insulin is administered to the hypothermic patient, intensive monitoring of blood glucose is essential due to the increase in endogenous insulin secretion on rewarming. (c) 2005 Elsevier Ireland Ltd. All rights reserved.