Asian Cardiovascular and Thoracic Annals

The ability of dopamine to reverse oliguria has led to its ubiquitous renal protective use in patients at risk of acute renal failure. However, this diuresis is due primarily to inhibition of distal tubular sodium reabsorption and not renal vasodilation. Recent controlled clinical studies have been unable to demonstrate a renal protective effect independent of changes in cardiac output.

Selective decontamination of the digestive tract (SDD) has the appealing theoretical ability to minimize upper gastrointestinal colonization with gram-negative bacteria and fungi, and subsequently reduce nosocomial infection and mortality. Such modification of flora does occur, but the initial studies showing a reduction in lower respiratory tract infections have not been supported by recent large double-blind randomized controlled trials. A reduction in mortality or length of stay of general intensive care patients given SDD has never been demonstrated, and it remains an experimental therapy with possible application for some patient subgroups.

Upper gastrointestinal hemorrhage (UGH) in the critically ill is associated with prolonged ventilatory support and coagulopathy, but clinically important bleeding is now uncommon. Prophylaxis with agents that increase gastric pH is effective in reducing UGH, but may be associated with a higher incidence of nosocomial pneumonia than occurs with alternatives such as sucralfate. Prophylaxis does not alter mortality, and it is now controversial which patients, if any, should routinely receive such treatment.

Multiple thrombolytic agents are available for treating patients with acute myocardial infarction. The recently completed Global Utilization of Streptokinase and rt-PA for Occluded coronary arteries (GUSTO) study randomized 41,000 patients to 1 of 4 thrombolytic treatment regimens. Straub Clinic and Hospital, a small community hospital in Hawaii, participated in this international clinical trial enrolling a total of 40 patients. Our patient characteristics and use of concomitant therapy were similar to the combined GUSTO, study results. Coronary angiography was performed in 93% of patients postthrombolytic therapy, with a majority of patients having single vessel coronary disease and a patent infarct-related artery. The severity of coronary artery disease at our hospital was similar to the combined GUSTO study results. Percutaneous transluminal coronary angioplasty was performed in 53% of patients and coronary artery bypass surgery in 13% of patients postthrombolytic therapy at our hospital, compared to 15% and 9% in the combined GUSTO study, respectively. The clinical events postthrombolytic therapy at Straub Clinic and Hospital were similar to the combined GUSTO study results, except for a lower incidence of ischemia/reinfarction at our hospital (7.5% v 23.2% respectively).

These data suggest that treatment of acute myocardial infarction with thrombolytic therapy can be administered in a safe and timely manner at a small community hospital.

Persistent heart failure is a major problem in low birth weight infants with patent ductus arteriosus (PDA). There is a considerable incidence of renal insufficiency and reopening of the ductus after pharmacologic closure. Surgical closure of symptomatic PDA should therefore be indicated to avoid morbidity or mortality from heart failure and renal failure.

Between March 1990 and December 1993 there were 33 low birth weight infants who underwent surgical closure of PDA, ranging in age from 5 to 90 days (mean = 25) with 15 males and 18 females (M:F = 1:1.2). The patients were classified into 3 groups: group 1 (< 1000gm) 11 cases, group 2 (1000-1499gm) 10 cases, group 3 (1500-2499gm) 12 cases. The indications for surgical closure of PDA included: persistent heart failure in 28, renal insufficiency in 20, reopening of the ductus after pharmacologic closure in 16 and growth failure in 1.

The early mortality was 6% (2/33). Both of them were in group 1: one from necrotizing enterocolitis (NEC), and one from cytomegalovirus (CMV) infection on the 6th and 20th postoperative day respectively.

Late death occurred twice: the first case in group 1 from sepsis 35 days postoperatively, and the second in group 2 from pneumonia 3 months after surgery. The causes of late mortality in both cases were not related to surgery.

The 29 survivors are doing reasonably well during follow-up period.

Video-assisted thoracoscopy (VAT) is a new modality that allows visualization and access to the intrathoracic organs without performing posterolateral thoracotomy incision. Recent advancements in endoscopic equipment and surgical techniques have expanded the applications of VAT in thoracic surgery. We performed 171 VAT cases, which previously would have been performed through thoracotomy incisions in 116 patients. The operations performed included 3 wedge resections of the pulmonary nodule, 14 pleural or lung biopsies, 1 pericardial window formation, 93 sympathectomies, 40 bullectomies and pleurodeses, 16 biopsies or excisions of mediastinal mass, and 4 lobectomies. Patients who received operation by VAT seemed to have much less postoperative pain and lower complication rates allowing early recovery and shorter hospitalization.

We describe our experience in 71 patients operated on between September 1991 and July 1993 for a variety of intracardiac procedures via right thoracotomy incision. The technique provides adequate exposure for mitral, tricuspid, aortic, and atrial septal surgery. The most significant advantage is the cosmetic result, which is highlighted.

We retrospectively reviewed our 20-year experience of patients with ventricular septal defect(VSD) and Down syndrome (DS) to evaluate operative mortality, morbidity, long-term survival, and quality of life after correction of VSD. Between 1971 and 1991, VSD was corrected on 32 patients with DS, 12 male and 20 female, with an average age of 1.9 years. Operative mortality was 3.1% (1/32). Few postoperative complications developed including transient cardiac arrhythmias and low cardiac output. All survivors were free from reoperation with an average follow-up period of 6.8 years. Actuarial survival at 20 years was 97.9%. As many as 93% of the survivors were in New York Heart Association functional class I. Average pulmonary artery pressure in the long-term period was significantly less than preoperative value. Although simple daily activities such as having meals and dressing themselves were performed satisfactorily by more than 90% of the survivors, only 26% of them were able to converse with full understanding. These data suggest the presence of DS does not present a disadvantage for correction of VSD, which may be followed by excellent survival and functional class in spite of limited social activity.

We report our experience using the new noninvasive treatment for coronary patients called enhanced external counterpulsation (EECP). Thallium-201 stress scintigraphy and treadmill test were done before and after 36 sessions of EECP treatment on 38 coronary patients.

The results showed significant (P < 0.01) improvement in perfusion as well as exercise tolerance in 86.8% and 94.2% of patients, respectively. The symptoms of angina pectoris and functional classes of the patients also showed significant (P < 0.05) improvement. All patients tolerated the treatment without serious complications.

The magnitude and rate of increased exercise tolerance achieved by EECP treatment was greater than those achieved by training after coronary bypass surgery (CABG) or exercise training rehabilitation program for the matched coronary patients reported by others ^7,8 .

The mean double products (DP) from the treadmill test results of the improved Tl-201 perfusion subgroups decreased significantly (P < 0.001). On the contrary, the DP of the unimproved subgroup increased significantly (P < 0.001). This could mean improvement in efficiency of the heart in the former, that is, more work was done with lower pressure-pulse products.

We reviewed our experience of 56 patients from 1989 to 1992 who underwent a modified Fontan procedure and a bidirectional cavopulmonary shunt simultaneously. There were 39 male and 17 female patients and their weight ranged from 6.54 to 29kg (mean weight 13.58 ± 3.96kg). Patient age ranged from 16 to 135 months (mean age 42.8 ± 3.7 months). Diagnoses included single ventricle in 29, tricuspid atresia in 11, double outlet of right ventricle in 10, hypoplastic left heart syndrome in 4, and pulmonary atresia with intact ventricular septum in 2 patients. The techniques of inferior vena cava to pulmonary artery (IVC-PA) connection were anastomosis of proximal superior vena cava (SVC) to pulmonary artery (PA) in 27 (group 1), direct atriopulmonary anastomosis with roof formation in 29 patients (group 2). There were significant differences in postoperative 1-hour right atrial (RA) pressure and period of chest tube drainage between group 1 and group 2. The early mortality was 12.5% (7/56), and 2 late deaths (4.1%) occurred with a mean follow-up period of 22.4 months. Risk factors for the late postoperative arrhythmia were immediate postoperative arrhythmia and prolonged pleuro-pericardial effusion. Direct connection of the remaining proximal SVC to PA with the bidirectional cavopulmonary shunt may have less pleuro-pericardial effusion and late arrhythmia than atriopulmonary anastomosis.

The relative merits and efficacy of open versus closed mitral valvotomy remains controversial. The purpose of this study was to compare improvement of the hemodynamic parameters and exercise tolerance capacity of the 2 operations in 59 patients with pure mitral stenosis in sinus rhythm. Patients were randomly assigned to 1 of 2 groups: 29 patients in group 1 were operated on with the closed technique and 30 patients in group 2 were operated by the open technique. Preoperatively, the hemodynamic parameters and exercise capacity were similar in the two groups. Cardiac catheterization and exercise treadmill test were performed on all patients before and 3 months after each operation. Hemodynamic parameters as well as exercise tolerance capacity were significantly improved by both open and closed valvotomy (p < 0.0001). However, postoperatively the improvement in exercise capacity was similar in both groups (p = NS) and there was no significant difference in hemodynamic parameters in both groups, except for reduction in pulmonary artery pressure and increment in cardiac output. Complication rates were similar in both groups, except for atrial arrhythmias, which were more common in group 2. This study suggested that the closed technique, when performed by experienced surgeons, achieved similar hemodynamic and functional results as the open method. It also has the potential advantage of cost savings in addition to avoiding the complications of cardiopulmonary bypass. It clearly has a place in properly selected patients with mitral stenosis.

Thermocoagulation with hot air is a new hemostatic procedure. During pulmonary surgery oozing blood and air leaking can be controlled by sweeping a high velocity air stream of about 420°C Cover a pulmonary surface stripped of visceral pleura. The hot air thermocoagulator can also control oozing of blood from the epicardium.