Hybrid noncovered open stents in repair of DeBakey type 1 acute aortic dissections.

OBJECTIVES: The indications for use, evidence base and experience with the novel noncovered open hybrid surgical stents for acute type A aortic dissection repair for concurrent stabilization of the 'downstream' aorta remains limited. We review the evidence base and the development of these stents. METHODS: Data were collected from Pubmed/Medline literature search to develop and review the evidence base for safety and efficacy of non-covered surgical stents. Existing guidelines for use and developments were reviewed. RESULTS: A single randomized control trial and 4 single-centre studies were included in the review with a total worldwide experience of 241 patients. The deployment was easy and did not add significantly to the primary operation. The mortality and new stroke ranged from 6.3-18.7%. Safe and complete deployment was accomplished in 92-100%. There was no device-related reintervention. There was a significant improvement in malperfusion in over 90% of the cases with varying degrees of remodelling (60-90%) of the downstream aorta. CONCLUSIONS: Open noncovered stent grafts represent a major technical advancement as an adjunct procedure for acute dissection repairs, e.g. hemiarch repair. It has potential for wider use by non-aortic surgeons due to simplicity of technique. Limited safety and efficacy data confirm the device to be safe, feasible and reproducible with potential for wider adoption. However, long-term trial and registry data are required before recommendations for standard use outside of high-volume experienced aortic centres.

Extra corporeal membrane oxygenation as right heart support following left ventricular assist device placement: a new cannulation technique.

Extracorporeal membrane oxygenation is an established treatment for acute respiratory failure, or low cardiac output syndrome. This can be veno-venous, in which de-oxygenated blood is drained from the venous system and oxygenated before being returned to the venous system, and veno-arterial where the re-oxygenated venous blood is returned to the arterial system. Haemorrhage, sepsis and thrombo-embolism are common and potentially lethal complications. Left ventricular assist devices are a continually evolving technology, that may be used as a bridge to transplantation or destination therapy in end-stage cardiac failure. The VentrAssist™ left ventricular assist device is a small implantable, continuous flow centrifugal pump, that is controlled and powered by a percutaneous lead. However, in these patients, right heart failure may present as an acute event following weaning from cardiopulmonary bypass (CPB), or post-operatively in the intensive care unit. Patients who do not respond to inotropes and pulmonary vasodilators may need a right ventricular assist device (RVAD). We report a successful case of right heart assist extra corporeal membrane oxygenation used as temporary right heart support in combination with a VentrAssist™ left ventricular assist device. The use of right heart assist extra corporeal membrane oxygenation to help a failing right heart during left ventricular assist device placement is not new, however, our technique describes a novel method of cannulation of the femoral vein and pulmonary trunk via a tunnelled vascular tube graft, which allows the chest to be closed whilst on right heart support, and decannulation to proceed without resternotomy. This technique has also been used successfully subsequent to this.

The value of post mortems in cardiac surgery: learning from the dead.

BACKGROUND: Little information is available regarding the role of post-mortem in cardiac surgery. The cause of death by clinical presumption can be misleading. The aim is evaluate the role of post-mortem following cardiac surgery by comparing clinically attributed causes of death versus post-mortem findings. METHODS: A total of 10,099 cardiac operations were performed over a seven-year period in a single institution in the United Kingdom. There were 363 (3.6%) deaths. The mean age at death was 71 with 66.7% male. Of these, 348 (95.9%) patients underwent a post-mortem examination. RESULTS: There was a significant disparity between presumed and actual causes of death in 78 (22.4%) patients. The commonest unrecognised cause of death was cardiac causes (21 patients, 6.0%). The most overestimated cause of death was multi-organ failure, which was incorrectly diagnosed as the cause of death in 28 patients (8.0%). CONCLUSIONS: Post-mortem can determine unsuspected diagnoses in a significant proportion of patients undergoing cardiac surgery. It plays an important role in cardiac surgery and remains essential for quality assessment in perioperative treatment.

APT070 inhibits complement activation during in vitro cardiopulmonary bypass.

BACKGROUND: The proteins of the complement cascade play an important role in inflammation and the immune response. They have been shown to be activated during cardiopulmonary bypass (CPB), and may be responsible for the inflammatory response to CPB. We looked at the effect of APT070, an anti-complement agent, on human blood during in vitro CPB. MATERIALS AND METHODS: Four hundred millilitres of blood was venesected from healthy human volunteers and heparinised. To the blood was added either APT070 to a concentration of 50 microg/ml (n=5) or vehicle control (n=4). The blood was entered into an in vitro CPB circuit and circulated for 90 min. RESULTS: Our results showed that after 90 min of in vitro bypass APT070 significantly inhibited the activation of compliment as demonstrated by C3a (p=0.03) and sC5b-9 (p=0.01) levels, and reduced neutrophil stimulation as measured by CD11b expression (p=0.04 at 90 min). CONCLUSION: APT070 significantly inhibits complement and neutrophil activation. This result may have considerable implications, especially if it can be shown to decrease the inflammatory sequelae of CPB.

Cannulation techniques for temporary right and left ventricular support: simple solutions for a difficult problem.

End-stage cardiac failure where appropriate is best treated with cardiac transplantation. With improvements in medical therapy, the emergence of primary percutaneous coronary intervention, and an increasingly ageing population, patients with right, left or biventricular failure, who are not suitable for cardiac transplantation or long-term ventricular assist device therapy, present for cardiac surgery. The modern cardiac surgeon needs to have a safe strategy for dealing with these complex cases. We report two cases that illustrate simple and safe cannulation techniques for temporary left and right ventricular failure.

A lipopolysaccharide adsorber in adult cardiopulmonary bypass: a single centre randomised controlled pilot trial.

OBJECTIVES: The aim of this study was to describe the biochemical effects and safety of selective removal of endotoxin from whole blood using a lipopolysaccharide adsorber during complex cardiac surgery. METHODS: We carried out a single centre prospective randomised controlled pilot trial in patients undergoing elective cardiac surgery using cardiopulmonary bypass (CPB) at a large UK cardiothoracic institution. Seventeen patients were randomly allocated to one of two groups: with or without an adsorber included in the CPB circuit. Fourteen patients were included in a complete case analysis. Blood samples were taken at the time of consent, immediately following anaesthesia, at 60, 180 and 360 min after the institution of CPB, and the morning following surgery. Primary outcomes were plasma levels of endotoxin, IL-6, IL-8 and TNF-alpha. Secondary outcomes were measures of patient safety including blood chemistry and coagulation parameters, length of stay, and adverse events. RESULTS: No differences were seen in endotoxin or cytokine levels between adsorber and control groups at any of the measured time-points. No difference between groups was detected in measures of patient safety following the intervention. Haemoglobin and haematocrit were significantly lower in the intervention group pre-bypass, P=0.02 in both instances. CONCLUSION: There was no effect of the adsorber on endotoxin levels or inflammatory response in this study, we have demonstrated the device to be safe in a complex cardiac surgery setting.

Congenital defects of the pericardium.

Congenital defects of the pericardium are rare, but when they are reported they are frequently associated with other cardiac lesions. We describe a case of partial pericardial defect found incidentally at surgery for closure of an ostium primum atrial septal defect. Proposed mechanisms of pericardial defect development are discussed and we suggest that associations with congenital and acquired heart disease are mostly circumstantial.

Right pulmonary artery occlusion by an acute dissecting aneurysm of the ascending aorta.

We describe the case of a 76-year old female who presented with a Type A aortic dissection requiring repair with an interposition graft and aortic valve replacement. Post-operatively she had clinical features and computerised tomographic images suggestive of a pulmonary embolus and died 24 hours later. The extremely rare finding of intramural thrombus occluding the right pulmonary artery was seen at post mortem.