Mitral valve replacement and Hunter syndrome: case report.

We report a rare case of mitral valve stenosis secondary to Hunter syndrome, mucopolysaccharoidosis (MPS) type II in a 33-year-old man. Anatomical abnormalities in patients with MPS present anesthetic and surgical challenges during cardiac surgery. Management of this particular patient was complicated by excessive oral secretions and atrial fibrillation. With a detailed preoperative assessment and planning for airway management, this patient successfully underwent mitral valve replacement and had an uncomplicated hospital course. After 6 months of follow-up, the patient was still in stable condition.

Surgical treatment of the atrial septal defect in adults: effective reduction in cardiac size and excellent overall clinical outcome.

OBJECTIVE: Atrial septal defect (ASD), one of the commonest congenital heart lesions, is asymptomatic in most cases and therefore remains undiagnosed until adulthood in a significant number of patients. Despite the employment of transcatheter modalities in its treatment, surgery remains a reliable alternative. This study summarizes our experience in surgical correction of ASD in adult patients. METHODS: Over a 9-year period (September 1997-August 2006), 171 patients, 73 males and 98 females, aged 18-72 (median 35) years, underwent surgical repair of ASDs'. Of these, 141 patients (82%) had ASD of the secundum type and 30 (18%) sinus venosus ASD with partial anomalous pulmonary venous connection (PAPVC). Fifteen patients with different principal diagnoses and concomitant ASD's were excluded, as were those with ostium primum ASDs'. Eighty six patients (50%) were asymptomatic and 11 (6.4%) had established arrhythmias. Two patients had recurrent lesions, 5 had a previously failed attempted transcatheter closure of which 3 were admitted as emergencies. All underwent complete surgical repair. RESULTS: Two patients (aged 53 and 69 years) with chronic atrial fibrillation suffered embolic strokes (1.16%), with one of the two subsequently dying from cerebral haemorrhage (0.6%). Other postoperative complications (including atrial arrhythmias) were treated successfully. Median ICU and hospital stay were 1 and 6 days respectively. Significant reduction in heart size was noted postoperatively as defined by the reduction in the cardiothoracic ratio (p=0.003). At mean follow up of 55+/-28 months, there was one late death from heart failure in a patient with advanced preoperative disease. All other patients remain in excellent clinical condition. CONCLUSION: Surgical correction of ASD is associated with low morbidity and mortality. Arrhythmias and their complications could be prevented by early surgical treatment.

Tetralogy of Fallot: influence of right ventricular outflow tract reconstruction on late outcome.

Surgical repair of Tetralogy of Fallot (TOF) is followed by very good early and medium-term results (perioperative mortality < or =5%), but there is increasing awareness of the occurrence of late adverse events: many patients experience progressive right ventricular (RV) dilatation/dysfunction leading to symptomatic right ventricular failure, arrhythmias, need for reoperation(in 5-15% of patients within 5-20 years after initial correction ), and late death. Although some predisposing factors such as complexity of anatomy (borderline pulmonary artery (PA) size, right ventricular outflow tract (RVOT) hypoplasia), age at operation, or prior shunting appear to affect early or late outcome adversely, it is debatable if other factors such as type of repair or use of a transannular patch correlate with poor late outcome or increased reoperation rates. Obviously, if careful study reveals specific modifiable factors predisposing to adverse late events (e.g. component of surgical technique), appropriate modification in surgical management may lead to improved late outcome.

Extracorporeal membrane oxygenation circulatory support after cardiac surgery.

OBJECTIVES: Postcardiotomy acute severe heart failure cannot be managed by medical treatment alone and most often requires some form of mechanical support. In this study we evaluate the efficacy of postoperative extracorporeal membrane oxygenation (ECMO) support following surgery for congenital heart disease (CHD) in infants and children. METHODS: Over a 6-year period from October 1997 to October 2003, 10 patients aged 5 days to 28.5 months (median 3 months) who underwent surgical procedures for CHD received postoperative mechanical support for failing cardiac function despite optimal medical therapy. In 3 patients ECMO was instituted in the operating room (OR) and in 7 patients this was introduced in the intensive care unit (ICU) 2 to 48 (median 20) hours postoperatively. RESULTS: Four patients (40%) were successfully weaned, while support was withdrawn in the remaining 6 due to irreversible vital organ damage. Following successful weaning, one of the survivors died 8 hours later from barotrauma and intrapulmonary hemorrhage, and another died 4 months later from persistent heart failure. The other two patients remain well in NYHA class II. CONCLUSIONS: Despite the adverse effects of ECMO, the methodology provided the necessary support and allowed the failing heart to recover in a number of patients where inotropic support alone proved inadequate.

Early results after transatrial/transpulmonary repair of tetralogy of Fallot.

OBJECTIVES: Right ventricular (RV) dysfunction is a significant cause of morbidity and mortality after surgical correction of tetralogy of Fallot (TOF). Transatrial/transpulmonary repair avoids a ventriculotomy (in contrast to the transventricular approach) emphasizing maximal preservation of RV structure and function. We have adopted this technique as less traumatic for the right ventricle. This study evaluates the early surgical results of our approach. METHODS: Between September 1997 and July 2001, 110 consecutive patients with TOF were referred to our unit for surgical therapy. Of these, 14 were unsuitable for repair and underwent aortopulmonary shunting+/-pulmonary artery patching. In the remaining 96 patients (median age 1.4 years), complete transatrial/transpulmonary repair was performed. Previously placed shunts (ten patients) were taken down and any secondary stenoses or branch pulmonary artery distortion repaired. In all cases, subpulmonary resection and ventricular septal defect (VSD) closure were accomplished transatrially. Whenever pulmonary valvotomy and valve ring widening were necessary, it was achieved through a pulmonary arteriotomy. In 84 patients the main pulmonary artery was augmented with an autologous pericardial patch, and in 23 the patch was extended to pulmonary artery branch(es). A limited (<1cm ) or extended (>1cm, but

A multicenter evaluation of total intravenous anesthesia with remifentanil and propofol for elective inpatient surgery.

Remifentanil is a mu-opioid receptor agonist with a context sensitive half-time of 3 min and an elimination half-life < or = 10 min. This study sought to evaluate the efficacy of remifentanil and propofol total intravenous anesthesia (TIVA) in 161 patients undergoing inpatient surgery. Remifentanil 1 microgram/kg was given intravenously (i.v.) followed by one of two randomized infusion rates: small dose (0.5 micrograms.kg-1.min-1) or large dose (1 microgram.kg-1.min-1). Propofol (0.5-1.0 mg/kg i.v. bolus and 75 micrograms.kg-1.min-1 infusion) and vecuronium were also given. Remifentanil infusions were decreased by 50% after tracheal intubation. End points included responses (hypertension, tachycardia, and somatic responses) to tracheal intubation and surgery. More patients in the small-dose than in the large-dose group responded to tracheal intubation with hypertension and/or tachycardia (25% vs 6%; P = 0.003) but there were no other differences between groups in intraoperative responses. Recovery from anesthesia was within 3-7 min in both groups. The most frequent adverse events were hypotension (systolic blood pressure [BP] < 80 mm Hg or mean BP < 60 mm Hg) during anesthesia induction (10% small-dose versus 15% large-dose group; P = not significant [NS]) and hypotension (27% small-dose versus 30% large-dose group; P = NS), and bradycardia (7% small-dose versus 19% large-dose group; P = NS) during maintenance. In conclusion, when combined with propofol 75 micrograms.kg-1.min-1, remifentanil 1 microgram/kg i.v. as a bolus followed by an infusion of 1.0 microgram.kg-1.min-1 effectively controls responses to tracheal intubation. After tracheal intubation, remifentanil 0.25-4.0 micrograms.kg-1.min-1 effectively controlled intraoperative responses while allowing for rapid emergence from anesthesia.

Pressure gradient across the pulmonary artery anastomosis during lung transplantation.

BACKGROUND: Perioperative monitoring of pulmonary artery (PA) pressures in lung transplant recipients is critical. This report characterizes an intraoperative gradient across the PA anastomosis in a series of patients undergoing bilateral sequential lung transplantation. METHODS: Hemodynamic measurements were obtained in a series of 10 patients before anesthetic induction, during one-lung ventilation/perfusion of the newly transplanted first lung with the PA catheter proximal and distal to the anastomosis and after arrival in the intensive care unit. The following measurements were recorded: central venous pressure, cardiac output, PA occlusion pressure, and systemic and pulmonary arterial pressures (systolic, diastolic, mean). RESULTS: Although a systolic pressure gradient of more than 10 mm Hg across the anastomosis was observed in all patients, there was a significant variation in systolic (13 to 59 mm Hg), diastolic (2 to 10 mm Hg), and mean (5 to 27 mm Hg) PA gradients. Mean proximal systolic PA pressure measurements (56.2 +/- 20.6 mm Hg) were greater when compared to measurements obtained distal to the anastomosis (28.6 +/- 10.1 mm Hg, p = 0.001) and to those obtained in the postoperative period (32.1 +/- 9.7 mm Hg, p = 0.004). CONCLUSIONS: The present study demonstrates that during single-lung ventilation and perfusion, the PA pressure measured proximally may not reflect accurately the pressure distal to the vascular anastomosis.

Regional and global myocardial circulatory and metabolic effects of isoflurane and halothane in patients with steal-prone coronary anatomy.

The use of isoflurane in patients with coronary artery disease remains controversial because of the possibility of "coronary steal". In this study, the effects of isoflurane and halothane on global and regional myocardial blood flow and metabolism were compared, and the relationship between steal-induced myocardial ischemia and the administered volatile anesthetic was investigated in 40 patients with steal-prone coronary anatomy undergoing elective coronary artery bypass operations. The patients were randomly assigned to receive either isoflurane or halothane (0.5 MAC inspired concentration) immediately after induction with fentanyl (50 micrograms/kg). Hemodynamic measurements and blood samples were obtained at preinduction, postintubation, preincision, poststernotomy, at 60 min after beginning isoflurane or halothane, and precannulation (a total of 238 study events). Throughout the study, heart rate was kept constant by atrial pacing at approximately postintubation values while arterial pressure was maintained within 10% of postintubation values with fluid administration or phenylephrine infusion. Overall, systemic hemodynamic changes observed during the study were similar in the two groups. Myocardial ischemic episodes were defined as a new electrocardiographic ST-segment shift of greater than or equal to 0.1 mV, new echocardiographic regional wall motion abnormalities (RWMA) and/or myocardial lactate production (MLP). A total of 18 new ischemic episodes were detected in 15 patients (7 episodes during isoflurane in 7 patients and 11 during halothane in 8 patients). Ten (56%) episodes were related to acute hemodynamic abnormalities, whereas 8 (44%) were random and unrelated to changes. Seven episodes were detected by echocardiography (38%), 6 by MLP (33%) and 1 by ECG (6%) only, whereas concomitant echocardiographic abnormalities and MLP were observed during 2 episodes (11%), echocardiographic and ECG during 1 (6%), and ECG and MLP during 1 other (6%). Ratios of regional to global coronary venous flow, coronary vascular resistance, myocardial oxygen content, and lactate extraction, along with hemodynamic data obtained during these episodes, do not support coronary steal for the development of myocardial ischemia. We conclude that in patients with steal-prone coronary anatomy anesthetized with fentanyl, neither isoflurane nor halothane administered at concentrations used in the current study is likely to cause myocardial ischemia by the coronary steal mechanism.