Michel Van Dyck

Functional Anatomy of Aortic Regurgitation Accuracy, Prediction of Surgical Repairability, and Outcome Implications of Transesophageal Echocardiography

Background— For patients with aortic regurgitation (AR), aortic valve sparing or repair surgery is an attractive alternative to valve replacement. In this setting, accurate preoperative delineation of aortic valve pathology and potential repairability is of paramount importance. The aim of the present study was to assess the diagnostic value of preoperative transesophageal echocardiography (TEE) in defining the mechanisms of AR, as identified by surgical inspection, and in predicting repairability, by using the final surgical approach as reference. Methods and Results— One hundred and sixty-three consecutive patients (117 males, mean age: 58±14 years) undergoing AR surgery were included. Mechanisms of AR were categorized by TEE and surgical inspection as follows: type 1, aortic dilatation; type 2, cusp prolapse; and type 3, restrictive cusp motion or endocarditis. At surgery, mechanisms of AR were type 1 in 41 patients, type 2 in 62, and type 3 in 60. Agreement between TEE and surgical inspection was 93% (&kgr;=0.90). Valve sparing or repair was performed in 125 patients and valve replacement in 38 patients. TEE correctly predicted the final surgical approach in 108/125 (86%) patients undergoing repair and in 35/38 (93%) patients undergoing replacement. The gross anatomic classification of AR lesions by TEE was determinant of valve repairability and postoperative outcome (4-year freedom from > grade 2 AR, reoperation, or death, P=0.04). Conclusions— TEE provides a highly accurate anatomic assessment of all types of AR lesions. In addition, the functional anatomy of AR defined by TEE is strongly and independently predictive of valve repairability and postoperative outcome.

Functional classification of aortic root/valve abnormalities and their correlation with etiologies and surgical procedures.

Purpose of review Patients with aortic root pathology may benefit from ‘valve-conservation’ surgery although application of this philosophy is limited by a lack of ‘standardized’ surgical techniques. A functional classification of aortic root and valvular abnormalities has been developed in 260 patients and correlated with the etiology of the pathologic process and the surgical procedure performed. Early outcome was assessed using hospital records and medium-term follow-up by cardiological review. Recent findings From January 1995 until March 2001, 260 patients were operated on for aortic root pathology using valve-conserving surgical techniques. Hospital mortality was 2%; intra-operative echocardiography showed residual aortic regurgitation (Grade 1-2) in 11%, none in the remaining patients. Follow-up at a mean of 20 months (87% of patients) showed trivial or Grade 1 aortic regurgitation in 80%. Summary Application of a simple functional classification for aortic root pathology and aortic valve disease allows the logical application of ‘valve-conserving’ surgical procedures with excellent early and medium-term results.

Randomized trial of intermittent antegrade warm blood versus cold crystalloid cardioplegia

BACKGROUND We performed a prospective randomized trial to compare intermittent antegrade warm blood cardioplegia with intermittent antegrade and retrograde cold crystalloid cardioplegia. METHODS Two hundred consecutive patients scheduled for isolated coronary bypass surgical procedures were randomized into two groups: Group 1 (n = 92) received cold crystalloid cardioplegia with moderate systemic hypothermia, group 2 (n = 108) received intermittent antegrade warm blood cardioplegia with systemic normothermia. Preoperative, intraoperative, and postoperative data were prospectively collected. RESULTS For the same median number of distal anastomoses, cardiopulmonary bypass duration and total ischemic arrest duration (57.3 +/- 20.5 versus 75 +/- 22.1 minutes, p < 0.001) were shorter in group 2 than in group 1. Apart from a higher right atrial pressure in the cold cardioplegia group, no hemodynamic difference was observed. Aspartate aminotransferase, creatine kinase-MB fraction, and cardiac troponin I levels were significantly lower in group 2 than in group 1. Outcome variables were not significantly different. CONCLUSIONS Intermittent antegrade warm blood cardioplegia results in less myocardial cell damage than cold crystalloid cardioplegia, as assessed by the release of cardiac-specific markers. This beneficial effect has only marginal clinical consequences. Normothermic bypass has no deleterious effect on end-organ function.

Transesophageal echocardiographic evaluation during aortic valve repair surgery

For patients with aortic valve (AV) disease, the classic treatment has been AV replacement and this remains true for aortic stenosis. In contrast, repair of isolated aortic insufficiency (AI), with or without aortic root pathology, is emerging as a feasible and attractive option to replacement. The AV is one of the elements of the aortic root. As such, AI can develop if one or more elements of the aortic root are diseased. Intraoperative transesophageal echocardiographic evaluation permits analysis of the mechanisms of aortic regurgitation as well as differentiation between repairable and unrepairable AV pathology. Immediate postrepair transesophageal echocardiography provides important information about the quality and durability of repair and identifies variables associated with recurrent AI.

Complications after aortic valve repair and valve-sparing procedures

In patients with chronic isolated aortic insufficiency (AI), surgical indications are based on presence of symptoms, severity of AI, left ventricle (LV) dysfunction or severe LV dilatation. Once deemed necessary, surgery will usually consist of valve replacement with a mechanical or a biological prosthesis. However, aortic valve (AV) repair can now be considered in surgical centers that have developed the appropriate technical expertise, gained experience in patient selection and have demonstrated outcomes equivalent to those obtained with AV replacement (1,2). Repairing the AV is associated with low mortality, acceptable durability, and a low risk of valve-related events such as endocarditis, hemorrhage and thromboembolism (3,4). In this paper, we review our 15 years’ experience in 475 patients, that has grown as a learning curve, and we detail some complications that have driven us to refine the surgical techniques. These complications can be divided into immediate unsatisfactory repair necessitating a second cardiopulmonary bypass (CPB) run (n=26, 5.5%), short-term reoperations (during hospital stay) (n=7, 1.5%), and long-term reoperations (n=21, 4.4%) (4).

Anaesthetic management of a prematurely born infant with Cantrell's pentalogy.

Cantrells pentalogy (CP) is a rare congenital syndrome combining a defect of the supraumbilical abdominal wall, the agenesis of the lower part of the sternum and of the anterior portion of the diaphragm, the absence of the diaphragmatic part of the pericardium, and a cardiac malformation. It was first described by Cantrell in 1958 (1,2). We report the case of a prematurely born infant with CP and Wolff–Parkinson–White (WPW) syndrome who required surgery first for bilateral inguinal hernia repair and later for Blalock–Taussig shunt. During these two procedures, our anaesthetic plan was to preserve the fragile equilibrium of both the pulmonary and the cardiovascular systems.

The role of echocardiography in aortic valve repair

Echocardiography is the imaging method of choice for evaluating aortic valve repair for aortic regurgitation (AR). This article will discuss the role of echocardiography in the assessment of the severity, hemodynamics and mechanism(s) of AR, along with its role in the perioperative assessment of aortic valve repair.

Aortic regurgitation after left ventricular assist device placement.

A 1 60-YEAR-OLD man with a history of recent heart failure caused by both primitive and ischemic dilated cardiomypathy underwent the successful implantation of a left ventriclar assist device (Novacor LVAS; WorldHeart, Ottawa, ON, anada) under cardiopulmonary bypass. Intraoperative transsophageal echocardiography (TEE) performed immediately fter implantation showed the correct placement of both the nflow and the outflow grafts (Fig 1) and the absence of any ortic regurgitation or aortic valve pathology. His immediate postoperative course was uneventful, and no ight ventricular assistance was needed. A routine follow-up ransthoracic echocardiogram performed in the intensive care nit on postimplantation day 9 disclosed mild central aortic egurgitation along with a mild pericardial effusion. Another ransthoracic echocardiogram performed on postimplantation ay 15 showed an aggravation of both the aortic regurgitation nd the pericardial effusion. Clinically, the patient was asymptomatic and had no fever or igns of peripheral hypoperfusion. Because the magnitude of he aortic insufficiency could preclude the correct functioning t

The dose of hydroxyethyl starch 6% 130/0.4 for fluid therapy and the incidence of acute kidney injury after cardiac surgery: A retrospective matched study

The safety of hydroxyethyl starches (HES) is still under debate. No studies have compared different dosing regimens of HES in cardiac surgery. We analyzed whether the incidence of Acute Kidney Injury (AKI) differed taking into account a weight-adjusted cumulative dose of HES 6% 130/0.4 for perioperative fluid therapy. This retrospective cohort study included all adult patients undergoing elective or emergency cardiac surgery with or without cardiopulmonary bypass. Exclusion criteria were patients on renal replacement therapy (RRT), cardiac trauma surgery, heart transplantation, patients with ventricular assist devices, subjects who required a surgical revision for bleeding and those whose medical records were incomplete. Primary endpoint was AKI following the creatinine based RIFLE classification. Secondary endpoints were 30-day mortality and RRT. Patients were divided into 2 groups whether they had received a cumulative HES dose of < 30 mL/kg (Low HES) or ≥ 30 mL/kg (High HES) during the intra- and postoperative period. A total of 1501 patients were analyzed with 983 patients in the Low HES and 518 subjects in the High HES group. 185 (18.8%) patients in the Low HES and 119 (23.0%) patients in the High HES group developed AKI (P = 0.06). In multivariable regression analysis the dose of HES administered per weight was not associated with AKI. After case-control matching 217 patients were analyzed in each group. AKI occurred in 39 (18.0%) patients in the Low HES and 50 (23.0%) patients in the High HES group (P = 0.19). In conditional regression analysis performed on the matched groups a lower weight-adjusted dose of HES was significantly associated with a reduced incidence of AKI [(Odds Ratio (95% CI) = 0.825 (0.727–0.936); P = 0.003]. In the absence of any safety study the cumulative dose of modern HES in cardiac surgery should be kept less than 30 mL/kg.

Acute Normovolemic hemodilution during CABG induces diastolic dysfunction: A perioperative transesophageal echocardiographic study

Background and Goal of Study: A previous study has shown that Acute Normovolemic Hemodilution (ANH) during CABG improves diastolic function.1 It is however based on transmitral doppler indices that are preload dependent.2 Tissue doppler imaging (TDI) could overcome this problem. Materials and Methods: Af ter Ethical approvement and informed consent, 51 patients (subgroup of another study) with normal systolic function and hemoglobin values were prospectively randomized to ANH group or C (control) group. In ANH group, a precalculated amount of blood was withdrawn and replaced with colloids af ter the induction of anesthesia. Hemodynamic and echocardiographic parameters were recorded af ter anesthesia induction (T0), af ter ANH (T1) and 15 minutes post sternotomy (T2). Af ter the confirmation of normal distribution, student t-test was used. Results and Discussion: The demographic data of the patients are shown in table 1.