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Biomedical subjects

T R Karl

Publications and source records attributed to T R Karl.

At least 55 records · Page 3Linked to original sources
PubMed1995

Intermediate-term outcome after intracardiac repair of associated cardiac defects in patients with atrioventricular and ventriculoarterial discordance.

BACKGROUND: Limited information is available concerning long-term results, especially systemic right ventricular (RV) or tricuspid valvular function, after intracardiac repair of anomalies associated with discordant atrioventricular (AV) and ventriculoarterial (VA) connections ("congenitally corrected transposition of the great arteries"). METHODS AND RESULTS: We retrospectively reviewed the intermediate-term follow-up of 28 patients, totaling 158 patient-years (median, 60 months), after intracardiac repair involving closure of a ventricular septal defect (VSD) with or without additional surgery. Seven patients had VSD closure alone, 5 had VSD repair with pulmonary stenosis relief, and 16 had VSD closure with conduit insertion between left ventricle and main pulmonary artery. Hospital mortality was 4% (1 of 28 patients; 70% confidence limits, 0.07% to 12%) and the 1-, 5-, and 10-year actuarial survival probabilities were 89%, 83%, and 83%, respectively. Twenty-one of 24 long-term survivors were in New York Heart Association functional class I and 3 were in class II. Sixteen of 24 patients showed increasing tricuspid regurgitation (TR) of more than moderate degree, which occurred within 3 years after surgery in 7 patients. Twelve of 22 patients showed deterioration of RV pump function, mainly (9 of 12 patients) within 3 years postoperatively. The pulmonary to systemic flow ratio at the preoperative cardiac catheter study was significantly (P < .05) higher in patients who developed RV dysfunction (2.3 +/- 1.0, mean +/- SD) than in those with well-maintained RV function (1.4 +/- 0.6). CONCLUSION: Intermediate-term results of intracardiac repair for AV and VA discordance were satisfactory in terms of survival and clinical functional status; however, there is concern about systemic RV dysfunction with development of TR relatively early after the operation. Alternative surgical approaches such as anatomic correction or Fontan repair for cases unsuitable for biventricular repair may improve the long-term results, including ventricular and valvular function.

Adolescent↗
PubMed1995

Heart transplantation for chyloptysis after Fontan operation.

Chyloptysis is a rare clinical problem, fewer than 10 patients having been reported in the literature. We report a patient with intractable chyloptysis associated with a Fontan procedure, who was palliated by heart transplantation.

Bronchial Fistula↗
PubMed1995

Pulmonary artery size after bidirectional cavopulmonary connection.

Pulmonary arterial size was measured during cineangiography in 23 patients, 1.9 months before, and 14 months after bidirectional cavopulmonary connection (BCPC). Measurements were standardized for body surface area using the method of Nakata and co-workers (pulmonary artery index). There was a significant reduction in pulmonary artery index after BCPC. These data suggest that pulmonary arterial growth is impaired after the creation of a BCPC. This may be related to an absolute reduction in pulmonary arterial flow, and/or the loss of systolic expansion of the pulmonary artery.

Cardiac Catheterization↗
PubMed1995

Surgical intervention for infective endocarditis in infancy and childhood.

BACKGROUND: Infective endocarditis is an uncommon but serious disease in children. Optimal treatment strategy, especially surgical indications, continues to evolve. METHODS: Retrospective review of 98 patients treated for infective endocarditis during the past 13 years at the Royal Children's Hospital, including medically and surgically treated patients. RESULTS: Thirty of 98 patients had surgical intervention with 6.7% hospital mortality, and 76% survival probability at 45 months. The remaining patients were treated medically, with 10% hospital mortality and 52% 5-year survival probability. The incidence of structural heart disease, congestive heart failure, and spectrum of organisms was similar in the two groups. CONCLUSIONS: Despite advances in antibiotic therapy, early surgical intervention is required in a significant subset. Concurrent intracardiac repair may be appropriate.

Adolescent↗
PubMed1994

Arterial switch: translocation of the intramural coronary artery.

Translocation of an intramural coronary artery is one of the most challenging problems in anatomic correction of transposition of the great arteries. Of 259 patients undergoing arterial switch procedure for transposition of the great arteries in our hospital, 12 (4.6%) were found to have intramural coronary arteries. The diagnosis was made intraoperatively in all patients. There were five different types of intramural coronary anatomy noted, with ostial stenosis present in half. The operative technique consisted of detachment of the posterior commissure of the aortic valve and unroofing of the intramural segment of the coronary artery by excision of a triangular portion of internal aortic wall. The coronary arteries were excised as a single disc, which was divided into two cuffs. The arterial switch was then performed in the usual fashion. The posterior commissure of the aortic valve was resuspended to the pericardial patch used to reconstruct the neopulmonary artery sinus. There were no operative or late deaths over a follow-up of 328 patient-months. Postoperatively, no patient showed ischemic changes on electrocardiogram or abnormal wall motion on echocardiogram. We believe that intramural coronary arteries can be managed satisfactorily with this technique, and that arterial switch will be possible in all cases.

Coronary Vessel Anomalies↗
PubMed1994

Surgical management of Marfan syndrome in children.

Between August 1983 and January 1991, seven patients with Marfan syndrome underwent surgery for severe cardiovascular complications. The mean age at presentation was 5.7 months (range 4 to 9 months) in the infant group (n = 3), and 13.3 years (range 10 to 16 years) in a group of older children (n = 4). The primary indications for surgery in the infant group (performed at a mean of 3 years after diagnosis) were ascending aortic aneurysm with valvar regurgitation in one patient, and severe mitral valve prolapse with regurgitation in two. In the older group, surgical indications (performed at a mean of 2.8 years after diagnosis) were ascending aortic aneurysm with valvar regurgitation in three patients and acute aortic dissection in one. For aortic surgery, a composite valved conduit was used in four patients, and an aortic homograft in one. For mitral valve surgery, mechanical prostheses were used. All patients survived the primary operation. Over a mean follow-up of 17.5 patient-years (range 1 to 9 years), two patients in the infant Marfan group went on to further successful surgery (prosthetic mitral valve replacement and aortic root repair with aortic homograft) at a mean interval of 4.3 years after the initial surgery. Our results suggest that the major cardiovascular risk factors of Marfan syndrome in the young, even in those diagnosed during infancy, have been favorably changed by surgery with an encouraging medium-term outlook. The correct timing of surgery is aided by echocardiography.

Adolescent↗
PubMed1994

Bloodless open-heart surgery in infants and children.

Between October 1984 and January 1993, seven children of Jehovah's Witnesses underwent corrective open-heart surgery for congenital defects, on cardiopulmonary bypass (CPB). Age at surgery ranged from three months to 6.5 years, and weight ranged from 4.2 kg to 23.2 kg, with two children weighing less than 10 kg. The principal cardiac anomalies were tetralogy of Fallot (two), double outlet right ventricle (one), subaortic stenosis (one), transposition of the great arteries and ventricular septal defect (one), atrial septal defect and congenital heart block (one), and congenital mitral regurgitation (one). Hypothermic CPB was used in all seven operations with crystalloid priming of the extracorporeal circuit. CPB was based on our standard perfusion protocols. All surgical procedures were done without the use of blood or blood products. The mean preoperative haematocrit (Hct) was 40.9% (range 31.0-47.8%). The mean lowest intraoperative Hct was 17.3% (range 15.0-24.3%), whereas the immediate post-CPB Hct was 19.6% (range 15.3-24.0%). The Hct progressively increased to 29.2% (range 21.0-34.2%) on the first postoperative day, and 32.3% (range 24.2-38.3%) at the time of discharge. There was no hospital mortality, and the mean hospital stay was 10 days (8-13 days). We report the safe repair of complex open-heart surgery in children, without blood transfusion, even in small infants. The successful management of these patients requires meticulous attention to surgical and perfusion technique, and sound postoperative management.

Blood Transfusion↗
PubMed1993

Staged conversion to arterial switch for late failure of the systemic right ventricle.

Late failure of the systemic right ventricle is seen in up to 10% of patients after atrial switch for transposition of the great arteries and in patients with atrioventricular and ventriculoarterial discordance. Since 1981, 24 such patients have entered a program to achieve conversion to arterial switch. The primary diagnoses were transposition of the great arteries with ventricular septal defect (n = 10), transposition of the great arteries with intact ventricular septum (n = 5), Taussig-Bing anomaly (n = 4), and atrioventricular and ventriculoarterial discordance (n = 5). The mean interval from atrial switch to right ventricular failure was 7 years. Four patients underwent direct conversion to arterial switch, with one operative death. In 3 of these patients the initial left ventricular pressure was high. The fourth patient was too sick to undergo banding, and he required left ventricular assist device support after switch conversion. The other 20 patients underwent 34 procedures to place or tighten a pulmonary artery band to prepare the left ventricle to tolerate systemic pressure. There was one band-related operative death. Twelve patients have thus far gone on to switch conversion 13 days to 5 years (mean, 26 months) after banding. In total, therefore, 16 patients have had an arterial switch with atrial reconstruction. The early mortality for switch conversion was 2 of 16 (12.5%; 70% confidence limits, 4% and 27%), with one late death 12 months after operation. Including operative mortality, the 1-year actuarial survival probability after conversion was 80% (70% confidence limits, 62% and 92%). All survivors are asymptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Pulmonary atresia with intact ventricular septum: surgical management based on right ventricular infundibulum.

The optimal management of infants with pulmonary atresia with intact ventricular septum (PA.IVS) remains a controversy. Attempts have been made to base the surgical approach on various geometrical or morphological characteristics of the right ventricle (RV). However, the overall results remain poor when compared to other complex congenital heart defects. Forty-eight neonates with PA.IVS were admitted to our unit between 1980 and 1992. The management plan has evolved to be based entirely on the echocardiographic assessment of the state of development of the infundibulum of the RV. In neonates with a well-formed infundibulum (n = 31), the initial palliation consisted mainly of pulmonary valvotomy (without cardiopulmonary bypass) and PTFE shunt from the left subclavian artery to the main pulmonary artery. There was one death from initial palliation in this subgroup. If necessary, the RV cavity was later enlarged by excision of the hypertrophic muscle of both the trabecular and infundibular portions, before finally attempting biventricular repair. The actuarial probability of achieving a biventricular repair at 40 months of age was 60% (95% CL = 39.5% to 71.3%). Thirteen patients have undergone biventricular repairs with one late death over a total follow-up of 1,720 patient months. In one patient, the RV failed to grow satisfactorily, necessitating a Fontan procedure. Seventeen patients without a well-formed infundibulum were approached with a Fontan procedure in mind. The initial palliation in these patients consisted of a modified Blalock-Taussig shunt only. Ten have undergone a Fontan procedure so far and five are awaiting such repairs. In this group there were four operative deaths: two after initial palliation, and two after Fontan procedures. In patients with a well-developed infundibulum, the actuarial survival probability was 93% (95% CL = 74% to 98%) at 8 months with no further late deaths over 120 months follow-up, whereas in patients without a well-formed infundibulum it was 75% at 40 months (95% CL = 46% to 89%). The overall survival probability at 104 months was 77% (95% CL = 51% to 90%).

Actuarial Analysis↗
PubMed1993

Long-term follow-up after two coronary repair of anomalous left coronary artery from the pulmonary artery.

A retrospective analysis of ten patients with anomalous left coronary artery arising from the pulmonary artery operated between 1979 and 1990 was undertaken. All presented with evidence of left ventricular dysfunction and "ischemic" mitral regurgitation. Surgical repair consisted of an aortopulmonary tunnel (Takeuchi) procedure in eight and direct left coronary artery reimplantation in two. Two patients required postoperative support with a left ventricular assist device. There were no operative or late deaths (CL 0% to 17%) for a follow-up of over 670 patient months. All patients are in New York Heart Association Class I or II, though two patients are still receiving anticongestive medications. One patient has required further surgery for pulmonary artery stenosis, and another has had a mitral valve replacement because of severe mitral regurgitation. One additional patient has moderate-to-severe residual mitral regurgitation and two have a trivial left coronary to main pulmonary artery fistula. All have a patent, nonstenotic left coronary artery and much improved left ventricular function and perfusion as assessed by echocardiography, thallium scan, gated blood pool scan, and angiography. There have been no documented arrhythmias, clinically or on Holter monitoring. The ECGs have shown resolution or improvement of the initial changes of ischemia/infarction in all patients. Chest X-rays have shown normalization of cardiothoracic ratio in eight of ten patients. Excellent early and late results can be achieved following timely surgical repair. Marked improvement in left ventricular function has been observed in patients with poor preoperative left ventricular function, even in the presence of extensive ischemia/infarction.

Child, Preschool↗
PubMed1993

Transatrial-transpulmonary repair of atrioventricular septal defect with right ventricular outflow tract obstruction.

Twenty patients had a repair of an atrioventricular septal defect with tetralogy of Fallot (n = 13) or double outlet right ventricle (n = 7). Mean age was 3.5 years. Surgical technique included transatrial-transpulmonary resection of right ventricular outflow tract obstruction and transatrial two patch repair of the atrioventricular septal defect. Ten patients required a transannular patch and one patient had a right ventricle-pulmonary artery conduit placed. There was no hospital mortality, and mean hospital stay was 15 days. One patient had late sudden death of unknown cause. Six patients have required reoperation because of residual ventricular septal defect (VSD), mitral incompetence, residual right ventricular outflow tract obstruction, and/or conduit stenosis. No patient was reoperated on because of left ventricular outflow tract obstruction. Fifteen patients are asymptomatic, one has exertional dyspnea, and two have intermittent occasional bronchospasm. The transatrial-transpulmonary two patch repair and extensive relief of right ventricular outflow tract obstruction have given good immediate results. Reoperation rate has been high mainly due to residual VSD and mitral incompetence.

Actuarial Analysis↗
PubMed1993

Cardiopulmonary bypass in neonates weighing less than 2.5 kg: analysis of the risk factors for early and late mortality.

A low weight has been implicated as one of the major reasons for deferring cardiac surgical procedures on cardiopulmonary bypass (CPB), resorting instead to palliative procedures. The purpose of this study is to analyze the risk factors associated with an increased mortality for surgery using CPB in small infants, and to compare this group with infants weighing over 2.5 kg. Between 1979 and 1990, 60 infants weighing less than 2.5 kg underwent surgery on CPB at our institute. The mean age was 17.9 days (range 1 to 68 days, SD = 16.4) and the mean weight was 2.1 kg (range 1.2 to 2.5, SD = 0.35). Eight had univentricular and 52 had biventricular repairs. The hospital mortality was 16.5% (70% CL 11.5% to 22.7%). The actuarial survival over 100 months was 67.5% (including hospital mortality). Over the same period, 946 patients under the age of 6 months but weighing more than 2.5 kg underwent surgery on CPB with a lower hospital mortality of 7.1% (70% CL 6.3% to 8.0%, p < 0.006). The risk factors associated with an increased risk of early death in the group weighing less than 2.5 kg were analyzed using logistic regression. They were: (1) presence of preoperative metabolic acidosis; (2) univentricular versus biventricular repair; and (3) duration of CPB. Within the less than 2.5 kg group, low weight per se did not affect the outcome adversely. The main cause of late death was the presence of associated medical conditions, notably bronchopulmonary dysplasia and tracheo bronchomalacia.

Cardiopulmonary Bypass↗
PubMed1993

Recent results with the modified Fontan operation.

From Jan 1989 to December 1991, 61 patients had modified Fontan procedures for a variety of lesions, including tricuspid atresia (18), mitral atresia (3), double inlet ventricle (14), isomeric hearts (4) and others (22). The hospital mortality was 1.6% (70% CL.0.2-5.3%). There were 2 late deaths. The median age at operation was 3.7 years (mean 5.6, range 1.5 to 20.3 years). There were two late failures at 2 months and 30 months after the operation, requiring take down of the Fontan in one and heart transplantation in the other. The 89% of the patients followed up are in NYHA class I or II at a mean follow up of 21.5 months (range 3-35 months). This suggests that the modified Fontan operation performed with the current patient selection criteria can be performed with a low mortality and that the early results are encouraging in the majority of the patients.

Adolescent↗
PubMed1993

Transposition of the great arteries with intact ventricular septum. Arterial switch repair in patients 21 days of age or older.

Since 1985 we have performed arterial switch repair for infants with simple transposition of the great arteries (with intact or virtually intact ventricular septum) who were younger than 2 months of age. As of December 1990, a total of 118 arterial switch operations had been performed for transposition of the great arteries with intact ventricular septum. Although correction is usually performed in the first 14 days of life, 18 infants had operations at or after 21 days (range 21 to 118 days; mean 38 days). Fourteen of 18 patients had echocardiographic or catheter evidence (or both) of low left ventricular pressure at the time of operation. None of these patients had preliminary pulmonary artery banding. Mortality was 5.6% (1 of 18 patients, confidence limit 0.8% to 17%) for the older group versus 0% (0 of 100 patients; confidence limit, 0% to 1.8%) for patients less than 21 days of age. The single death occurred in a 22-day old, 1.8 kg premature baby, probably as a result of a problem with a coronary anastomosis. One patient required a left ventricular assist device for 2 days after the operation. These data suggest that with appropriate perioperative management and support, the arterial switch procedure can be safely carried out as a primary procedure for patients up to the age of 1 month and probably up to the age of 2 months.

Age Factors↗