Anatomical mismatch of the pulmonary autograft in the aortic root may be the cause of early aortic insufficiency after the Ross procedure.

OBJECTIVE: Early aortic insufficiency can be a problem after the Ross procedure. Anatomical mismatch and an inexact surgical technique may lead to distortion of the normal pulmonary valve geometry and subsequent incorrect leaflet coaptation and valve insufficiency. In this study, we assessed the efficacy of changing and improving the surgical technique to minimize the early pulmonary autograft valve failure. The modifications and the strategy are discussed. METHODS: From January 1995 to February 1999, a total of 77 adults underwent the Ross procedure for aortic valve replacement at Sahlgrenska University Hospital. The operative technique used was full free-standing aortic root replacement with a pulmonary autograft in all cases. In the first 24 cases, the diameter of the pulmonary roots was seldom measured, eye-balling was used to exclude anatomical mismatch due to a dilated aortic root, and only one attempt of correction was made, which failed. In the other 53 cases, the technique was improved by: (1) reducing the aortic anulus diameter in cases with moderate dilatation; (2) excluding cases with severe dilatation of the aortic annulus; (3) adjusting the diameter of the sinotubular junction of the aorta to the diameter of the sinotubular junction of the pulmonary artery; (4). reimplanting the left ostium in the autograft, and (5) changing the proximal anastomosis technique. RESULTS: In this study, we had an early aortic incompetence of grade 2 in eight patients among the first 24 patients. In the other 53 patients, postoperative echocardiography at 1 week revealed aortic insufficiency of grade 2 in two patients. CONCLUSIONS: Aortic insufficiency after the Ross procedure can be minimized by patient selection, intraoperative correction of anatomical mismatch and improved surgical technique.

Insulin(GIK) improves myocardial metabolism in patients during blood cardioplegia.

The aim of this study was to test the hypothesis that abnormalities of myocardial substrate metabolism during blood cardioplegic aortic cross-clamping and early reperfusion are attenuated further by insulin(GIK) than by alpha-ketoglutarate enrichment of blood cardioplegia alone. Twenty-eight males (47 to 78 years) undergoing coronary artery bypass grafting (CABG) participated in a prospective, controlled, randomized study. All patients had alpha-ketoglutarate-enriched blood cardioplegia. Insulin(GIK) was infused in 13 patients during aortic cross-clamping. Insulin(GIK) prevented lactate release during cardioplegia (1.5+/-15 vs -44+/-14 micromol/min, p = 0.04), and a significant extraction of lactate was induced shortly after declamping the aorta (15+/-3 vs 2+/-1%, p = 0.001). Free fatty acid uptake was reduced after cardioplegic cross-clamping (5.7+/-1.6 vs 16.0+/-3.8 micromol/min, p = 0.02). More positive/less negative levels of alanine, aspartate, glutamine, glycine, ornithine, taurine and tyrosine were found in all the insulin-treated patients. We conclude that insulin(GIK) attenuates abnormalities of myocardial substrate metabolism during blood cardioplegic aortic cross-clamping and early reperfusion further than is obtained with alpha-ketoglutarate enrichment of blood cardioplegia alone.

Weaning from mechanical support in a patient with acute heart failure and multiple sclerosis.

We describe a 19-year-old woman developing acute left ventricular heart failure during her first exacerbation of multiple sclerosis. Histopathologic examination of myocardial tissue showed extensive myocytolysis. A left ventricular assist device was implanted. Three months later the cardiac function was restored and the left ventricular assist device was explanted. After 1 year the patient still remains well and her cardiac function is normal.

Addition of alpha-ketoglutarate to blood cardioplegia improves cardioprotection.

BACKGROUND: We hypothesized that myocardial content of alpha-ketoglutarate (alpha-KG), an intermediate of the Krebs cycle, can be critically low during heart operations, and that provision of alpha-KG could reduce metabolic abnormalities and lead to improved myocardial protection. METHODS: Twenty-four men aged 46 to 78 years who were undergoing heart operations participated in a prospective, controlled, randomized study. In 13 patients, an average of 28 g of alpha-KG was added to blood cardioplegia. Plasma creatine kinase isoenzyme MB and troponin T, and myocardial extraction of oxygen, substrates, and amino acids were measured. RESULTS: alpha-Ketoglutarate treatment was associated with lower creatine kinase isoenzyme MB (F = 39.6, df = 1.172, p < 0.001) and lower troponin (F = 12.9, df = 1.172, p < 0.001). The values at 4 hours were 31 +/- 2.4 microg/L versus 49 +/- 4.9 microg/L (creatine kinase isoenzyme MB) and 1.1 +/- 0.05 microg/L versus 2.0 +/- 0.34 microg/L (troponin T). Myocardial oxygen extraction was higher during alpha-KG cardioplegia (p < 0.01), but there were no significant differences in myocardial uptake or release of substrates or amino acids. Lactate release was observed in both groups during cardioplegia. Myocardial lactate release had ceased after 30 minutes of reperfusion in nearly half the alpha-KG-treated patients (6 of 13) but remained in all the control patients (11 of 11, p = 0.016). There were no other differences after 30 minutes of reperfusion. CONCLUSION: Provision of alpha-KG during blood cardioplegia improves myocardial protection in patients undergoing coronary operations. This may be linked to enhanced oxidation.

Preoperative echocardiographic prediction of small prosthesis size for aortic valve replacement.

BACKGROUND AND AIMS OF THE STUDY: Prosthesis size is known to have an effect on long term outcome after heart valve replacement. We evaluated 115 patients subjected to aortic valve replacement to assess the ability by preoperative echocardiography to identify patients having small aortic roots and thereby likely to receive a small prosthesis (size 19 or 21), previously shown to be associated with a worse prognosis. METHODS: From an initial part of the study (Group A), comprising 67 patients, we evaluated the influence of image quality on the accuracy for prediction of patients receiving a small prosthesis. In a second series of 48 patients (Group B), we tested the predictive value of various limits of aortic annulus diameter to define patients at risk of receiving a small prosthesis. RESULTS: The measurement of aortic annulus diameter in Group A gave a reasonable correlation to subsequent prosthetic dimension (r = 0.73, n = 59). However, there was a considerable variation of echocardiographic aortic annulus diameter among patients receiving prostheses of the same size. In Group B, an aortic annulus diameter of < or = 22 mm correctly identified 10 of 13 patients receiving a small prosthesis (sensitivity 77%). Twenty-two of 25 patients (88%) with an aortic annulus diameter > 22 mm received a large prosthesis. CONCLUSIONS: We conclude that the echocardiographic measurement of the aortic annulus diameter is a fairly sensitive method to identify patients receiving a small prosthesis. However, the predictive accuracy is dependent upon training as well as image quality. Furthermore, the value of planning in advance the type of prosthesis, annuloplasty or homograft for aortic valve replacement remains to be shown.

Alpha-ketoglutarate for myocardial protection in heart surgery.

A low myocardial content of alpha-ketoglutarate during heart surgery might aggravate ischaemic injury. 24 men undergoing coronary surgery participated in a randomised controlled study. 28 g alpha-ketoglutarate was added to blood cardioplegia for intermittent antegrade intracoronary perfusion in 13 cases. alpha-ketoglutarate reduced the appearance in blood of the ischaemic markers creatine kinase MB and troponin T (at 4 h after release of aortic cross-clamp; median [95% CI] 49 [37-60] micrograms/L in controls vs 32 [27-37] micrograms/L for creatine kinase MB, 2.0 [1.2-2.8] vs 1.1 [0.8-1.4] micrograms/L for troponin T). These findings signify attenuated ischaemic injury, possibly secondary to enhanced myocardial oxidative capacity.

Successful outcome after massive bleeding in a heart transplant recipient with mycotic aortitis. Case report.

Sudden mediastinal haemorrhage one month after heart transplantation in an 18-year-old youth was found to originate from a rupture of the ascending aorta associated with mycotic aortitis. Aortic continuity was restored with a Dacron graft. Cultures from the resected vessel wall showed Candida albicans. The patient recovered, and 11 months later is well.