Despite extensive research and great strides over the past 40 years, the ideal permanent mechanical assist device remains elusive. The incidence of heart failure is increasing, and the number of heart transplants has remained constant. The HeartMate and Novacor are two pulsatile, long-term ventricular assist devices (VADs) commonly used as a bridge to transplantation. Randomized Evaluation of Mechanical Assistance in the Treatment of Congestive Heart Failure is a randomized study of device therapy in heart failure with treatment either with device (HeartMate) therapy or maximal medical therapy which was recently completed and demonstrated a Kaplan-Meier survival rate at 1 year of 52% for the device group compared to 25% in the medical therapy group. The TCI HeartMate is the only device approved for destination therapy, while others such as the Novacor device are in the process of evaluation. Most of these devices are still plagued by mechanical problems, bleeding, thromboembolism and infection. Other promising new devices include smaller VADs using impeller pump technology, such as the Arrow LionHeart, Micromed Debakey pump and Jarvik 2000 pump. The CardioVAD is an interesting chronically implantable balloon pump inserted into the descending thoracic aorta. While experience with the newer implantable pumps is growing, most of them require some manipulation of the heart perioperatively, in addition to anticoagulation postoperatively and careful monitoring for complications and infection.
Sternal instability predisposes to post-operative mediastinitis. Biomechanical studies have shown the superiority of rigid plate fixation over wire circlage in sternal healing. We studied rigid plate fixation for sternotomies in high-risk patients. High-risk patients were identified as those having three or more historically established risk factors for post-operative mediastinitis, such as COPD, re-operative surgery, renal failure, diabetes, steroid use, obesity, existing infection, and immunosuppression. Three hundred and twenty high-risk patients had prophylactic rigid plate fixation (Group S) between July 2000 and Jan 2005. The control group (Group C) comprised 215 patients with similar risk profiles that were not plated during 2000 and 2001. Average age, male-female ratio, risk factors and type of procedures were similar in both groups. Follow up ranged from 4 to 200 weeks. There were 12 peri-operative deaths (3.75%) in group S and 8.6% (18 patients) in group C. There were no instances of deep mediastinitis in group S. Group C had mediastinitis in 28 (13%, P<0.05), requiring high dose antibiotics and plastic surgical intervention. Sternal fixation with titanium plates is an effective way of ensuring sternal immobility thereby reducing the substrate for bony infections. Application of this technique in high-risk patients prevents mediastinitis.
Study's purpose: Plasma levels of soluble receptor for advanced glycation endproducts (sRAGE) and S100A12 are increased in young children after cardiac surgery and correlate with the time spent on cardiopulmonary bypass (CPB). This study was performed to investigate whether plasma levels of sRAGE and S100A12 are affected by the use of CPB. Levels of S100A12 and sRAGE, along with of interleukin-6, tumor necrosis factor-α, myeloperoxidase, and C-reactive protein were measured in 25 adults undergoing non-urgent coronary artery bypass grafting with and without the use of CPB. Significant finding: Plasma levels of S100A12, sRAGE, IL-6, TNF-α and MPO 4h after cardiac surgery were elevated compared to baseline; this increase was equally observed in patients undergoing traditional coronary artery bypass grafting on cardiopulmonary bypass (n = 16), and in patients undergoing robot-assisted coronary artery bypass grafting off pump (OPCAB, n = 9). Patients with prolonged hospitalization of 7 days or longer had significantly higher S100A12 and sRAGE 4 hours post surgery compared to patients hospitalized ≤ 6 days.Increased sRAGE and S100A12 after cardiac surgery is associated with prolonged length of hospitalization in patients after coronary artery bypass grafting; however, we did not observe an intrinsic effect of cardiopulmonary bypass on S100A12 or sRAGE plasma levels in our small pilot study. Further studies are required to confirm the value of sRAGE and S100A12 in predicting postoperative complications after cardiac surgery in a larger study.
Background. A widely reported ABO-mismatch accident in March of 2003 raised concerns about the reliability of the transplantation system. Because this type of failure is rare and significant, we performed a probabilistic risk assessment (PRA) of the donor-recipient matching processes for thoracic organ transplantation. Methods. A probabilistic risk assessment was performed. Results. The likelihood of accidental incompatible implantation was already low in 2003. The PRA model indicates that the likelihood of such an event was 1.38×10−5 per donated organ. This estimate correlates closely with the observed rate of these accidents. Based on this model, process changes put in place shortly after the accident reduced the probability to ∼3.08×10−6 and changes put in place in October 2004 further reduced the probability to ∼2.22×10−7 per organ donated. Conclusions. The observed and predicted likelihoods of accidental incompatible thoracic organ transplantation are comparable. These likelihoods are several orders of magnitude smaller than other hazards associated with solid organ transplantation. The PRA model indicates that changes that followed the March 2003 accident further reduced the likelihood of accidental incompatible implantation by roughly two orders of magnitude. Quantitative estimates from PRA can be used to assess risks in healthcare and to gauge the impact of system changes on these risks.