Andrzej W. Sosnowski

Off-pump bypass graft operation significantly reduces oxidative stress and inflammation

BACKGROUNDnThis study investigated whether off-pump coronary bypass graft operations on the beating heart under normothermic conditions reduces the systemic oxidative stress and inflammatory reaction seen in patients operated under cardiopulmonary bypass (CPB).nnnMETHODSnA cardiac stabilizer (Octopus Tissue Stabilizer; Medtronic Inc, Minneapolis, MN) was used to perform the coronary anastomoses on the normothermic beating heart with or without CPB. Serial blood samples were taken at various intervals. Plasma was analyzed for several oxidative stress and inflammatory markers.nnnRESULTSnSignificant increases from prior anesthesia values of lipid hydroperoxides (190% at 4 hours), protein carbonyls (250% at 0.5 hours) and nitrotyrosine (510% at 0.5 hours) were seen in the CPB group, but they were abolished or significantly reduced in the off-pump group. Complement C3a and elastase levels were rapidly increased upon the institution of CPB, and this was followed by increases in IL-8, TNF-alpha, and sE-selectin. In contrast, the rise of these factors was blunted in patients operated without CPB.nnnCONCLUSIONSnOff-pump coronary bypass graft operation on a beating heart significantly reduces oxidative stress and suppresses the inflammatory reaction associated with the use of CPB.

Post infarction ventricular septal defect – can we do better?

OBJECTIVEnTo identify predictors of early and late outcome among 117 consecutive patients who underwent postinfarction ventricular septal defect (VSD) repair over a period of 12 years.nnnMETHODSnA retrospective analysis of clinical data was performed. Mean age was 65.5+/-7.8. There were 43 females. Full data were obtained in 110 patients. Of these, 76 patients presented with anterior and 34 with posterior VSD. Thirty-three patients were operated in cardiogenic shock. Mean time between myocardial infarction (MI) and VSD development was 5.6+/-7.8 days (median 4) and from VSD to surgery 9. 0+/-28.1 (median 2). Sixty-six patients had intraaortic balloon pump (IABP) inserted, and 15 were ventilated preoperatively. Logistic regression and Cox regression were used for multivariate analysis.nnnRESULTSnThirty days mortality was 37%. Among 110 patients, in whom complete analysis was possible, 38 died within 30 days (35%). Mortality in the posterior VSD group was 35% and in the anterior VSD group 34% (NS). In 44 patients (40%) a residual shunt was found on postoperative echocardiography. This required reoperation in 13 patients (four deaths). Cardiogenic shock prior to surgery adversely influenced early survival - odds ratio (OR) 5.7 (confidence interval (CI) 2.1-16.0) (P=0.0008). Deterioration of haemodynamic status in between admission and surgery was stronger predictor of mortality than shock on admission - OR 6.0 (CI 1.6-22.6) (P=0.008) vs. 3.1 (CI 1.0-9.3) (P=0.049). A longer time between MI and surgery favoured survival - OR 0.1 (CI 0.03-0.4) (P=0.002). The time period from the infarct to the septal rupture, but not from the rupture to surgery, appeared to be a significant predictor of survival - OR 0.2 (CI 0. 05-0.6) (P=0.008). Five years survival was 46+/-5%. Preoperative cardiogenic shock affected late survival - OR 2.7 (CI 1.5-4.9) (P=0. 001). Of 72 patients who survived 30 postoperative days, 12 (17%) were in New York Heart Association (NYHA) class III or IV and five (6.9%) in Canadian Cardiovascular Soceity (CCS) class III or IV at the last follow-up.nnnCONCLUSIONSnPreoperative cardiogenic shock and early postinfarction septal rupture carry a grave prognosis. Achieving haemodynamic stability prior to surgery may be beneficial but prolonged attempts to improve patients cardiovascular state are hazardous.

Mitral valve repair for active culture positive infective endocarditis

Objective: To describe the clinical and echocardiographic outcome after mitral valve (MV) repair for active culture positive infective MV endocarditis. Patients and methods: Between 1996 and 2004, 36 patients (mean (SD) age 53 (18) years) with positive blood culture up to three weeks before surgery (or positive culture of material removed at operation) and intraoperative evidence of endocarditis underwent MV repair. Staphylococci and streptococci were the most common pathogens. All patients had moderate or severe mitral regurgitation (MR). Mean New York Heart Association (NYHA) class was 2.3 (1.0). Follow up was complete (mean 38 (19) months). Results: Operative mortality was 2.8% (one patient). At follow up, endocarditis has not recurred. One patient developed severe recurrent MR and underwent valve replacement and one patient had moderate MR. There were two late deaths, both non-cardiac. Kaplan-Meier five year freedom from recurrent moderate to severe MR, freedom from repeat operation, and survival were 94 (4)%, 97 (3)%, and 93 (5)%, respectively. At the most recent review the mean NYHA class was 1.17 (0.3) (p < 0.0001). At the latest echocardiographic evaluation, left atrial diameters, left ventricular end diastolic diameter, and MV diameter were significantly reduced (p < 0.05) compared with preoperative values. Conclusions: MV repair for active culture positive endocarditis is associated with low operative mortality and provides satisfactory freedom from recurrent infection, freedom from repeat operation, and survival. Hence, every effort should be made to repair infected MVs and valves should be replaced only when repair is not possible.

Replacement of the Ascending Aorta, Aortic Root, and Valve with a Novel Stentless Valved Conduit

PURPOSEnBiologic valved-conduit grafts avoid the need for anticoagulation and can exploit the excellent hemodynamic performance of stentless valves. Incorporation of sinuses of Valsalva into the neoaortic root can improve the function of the stentless valves.nnnDESCRIPTIONnHere we present a novel prefabricated stentless valved conduit incorporating sinuses of Valsalva and describe the technique of implantation. The BioValsalva (Vascutek Terumo, Renfrewshire, Scotland) valved conduit incorporates a stentless porcine aortic valve (Elan; Vascutek Terumo) suspended within a triple-layered vascular conduit (Triplex; Vascutek Terumo) constructed with sinuses of Valsalva.nnnEVALUATIONnThe BioValsalva valved conduit was used in 12 patients with aortic regurgitation due to annuloaortic ectasia unsuitable for aortic valve repair and concomitant ascending aorta aneurysm, with no deaths and excellent functioned result.nnnCONCLUSIONSnThe prefabricated, composite, stentless valved conduit is composed of material that is hemostatic and reduces bleeding. It is easy to implant, with a short ischemic time, and lends itself well to a variety of insertion techniques.

Preassembled stentless valved-conduit for the replacement of the ascending aorta and aortic root.

Here we report the early clinical results of a new preassembled stentless valved-conduit incorporating artificial sinuses of Valsalva (BioValsalva). This new composite conduit incorporates a stentless porcine aortic valve (Elan, Vascutek Terumo, UK) suspended within a triple-layered vascular conduit (Triplex, Vascutek Terumo, UK) constructed with sinuses of Valsalva. Between December 2006 and January 2008, 17 patients with the mean age of 65 years underwent aortic valve, root and ascending aorta replacement with the BioValsalva valved-conduit. There was no perioperative mortality. There were no myocardial infarctions, cardiac failure or cerebrovascular events. Mean cardiopulmonary bypass time was 156+/-56 min and ischemic time was 112+/-33 min. Eight patients required deep hypothermic circulatory arrest for additional distal ascending aorta replacement. Mean mediastinal drainage was 499+/-262 ml. Postoperative transthoracic echocardiography and CT-scans of the aorta in all patients before discharge demonstrated well-functioning prosthetic aortic valves with small residual mean gradients, no regurgitation, and the presence of sinuses of Valsalva. In conclusion, the novel prefabricated, composite stentless valved-conduit BioValsalva possesses excellent hemodynamic performance and can be implanted with low morbidity. In addition, the conduit material has good hemostatic properties which reduced bleeding, and is easy to implant with a variety of surgical techniques.

A potential propensity for failure secondary to clot embolism in neonatal ECMO

Objective: To report a single case of oxygenator failure caused by clot embolism originating from the bladder; and to discuss some preventative options. Case report: A 2.5 kg neonate with a diagnosis of influenza A received veno-arterial (V / A) extracorporeal membrane oxygenation (ECMO) for cardiorespiratory support. Halfway through treatment, she underwent an elective circuit change for numerous clots in her circuit. The patient continued to consume vast quantities of platelets and developed a fatal oxygenator failure after 18 days. Discussion: Amongst the factors influencing the outcome in events of a sudden unexpected oxygenator failure are the severity of patient illness, the size of the clot relative to the size of the oxygenator, the availability of a previously primed circuit and the ease and speed of priming a new oxygenator. Conclusion: There is a need for improvement in the design of small oxygenators and ECMO circuits. Adjustment of the coagulation parameters and lowering the tolerance towards clots in the circuit by electively changing them may reduce the incidence of sudden unexpected oxygenator failure. However, using a slightly larger Medos oxygenator may gain valuable time needed to arrange an oxygenator/circuit change.