William Sawyer

Results of 546 Blalock-Taussig shunts performed in 478 patients

Between 1983 and 1995, 546 Blalock-Taussig shunt procedures were performed in 472 patients: 128 (23.0%) were classical shunts, 90 of them on the same side as to the aortic arch, and 418 (77.0%) were modified shunts, 182 on the same side of the arch. At the time of surgery, 78 patients were aged below one week, 270 from one week to 12 months, and 198 patients were over one year of age. The mean pre-operative arterial saturation (71.7% +/- 16.5%) was significantly increased to 83% +/- 17.9% immediately after the procedure (p=0.017). The overall hospital mortality rate was 2.9% (16/546), with rates of 2.3% (3/128) for the classical, and 3.1% (13/418) for the modified shunts (p=not significant). The rate was significantly higher, however, for classical shunts when the pulmonary arterial diameter was less than 4 mm (15.4% versus zero; p=0.047), though this relationship was reversed for modified shunts (zero versus 3.6%; p=0.338). Early mortality was significantly influenced by the age at surgery, 5/78 (6.4%) in patients aged below 1 week, 3.7% between 1 week and 1 year, and 0.5% over 1 year (p=0.019). Early mortality was also significantly increased in patients weighing 3kg or less, 8/156 (5.1%), versus 3/303 (1.0%), p=0.037. Overall, 51 shunts failed (9.3%), 10 early and 41 late. Early failure was significantly increased in patients weighing 3kg or less, 8/156 (5.1%) versus 3/303 (1.0%), p=0.016. The overall early failure rate was 1.4% (3/215) when heparin was administered intra-operatively and for 48 hours postoperatively, in contrast to an early failure rate of 3.4% (7/203) when heparin was not used (p=0.294). Overall rates of failure during follow-up were 9.1% (17/188) in heparinized patients versus 13.6% (24/177), (p=0.173) in non-heparinized patients. Failure of classical shunts was 10.2% (13/128), compared with 6.7% (28/418) for modified shunts (p=0.195). Failure was more common overall if the pulmonary arterial diameter was less than 4 mm, 14.7% (9/61), as opposed to 8.7% (26/300) when the diameter was 4 mm or greater, (p=0.144). Administration of aspirin during follow-up after the modified shunt procedure reduced failure from 11% (18/163) to 6.7% (10/150), p=0.176. Classical or modified Blalock-Taussig shunts, either on the same side or opposite to the aortic arch, can be performed on patients of any age with minimum postoperative complications and low operative mortality. The use of intra- and post-operative heparin appears to reduce the overall rate of failure, and the administration of aspirin during follow-up appears to reduce failure of modified Blalock-Taussig shunts.

Percutaneous catheter closure of the ductus arteriosus in children and young adults.

The double-disk occluding device suitable for use in infants and children with patent ductus arteriosus, developed by Rashkind and Mullins, has been available to this institution since December 1987 on an investigational basis. Results of 43 nonsurgical ductal closure attempts using this device in children and young adults between December 1987 and October 1988 are presented. Successful implantation was achieved in 42 patients (98%). In 25 patients a residual shunt was seen on angiography immediately after implantation. In 12 patients a residual ductal shunt was detected by Doppler 24 hours after implantation; 6-week follow-up studies showed a small residual shunt in only 3 patients. After a second occluder device was implanted in 2 of these patients, complete closure of the patient ductus arteriosus was achieved. In 1 patient, early in the series, the occluder device embolized to the left pulmonary artery, necessitating surgical removal at the time of ductus division. This event was the only serious complication; there were no deaths.

One-year follow-up after percutaneous double balloon mitral valvotomy.

Abstract To determine the long-term results after double balloon mitral valvotomy and the incidence of restenosis, 41 consecutive patients were restudied 1 year after successful balloon mitral valvotomy for severe symptomatic rheumatic mitral stenosis. There were 27 female and 14 male patients, mean age 26 ± 9 years.

Critical pulmonary valve stenosis in patients less than 1 year of age: Treatment with percutaneous gradational balloon pulmonary valvuloplasty

A new technique of percutaneous gradational balloon pulmonary valvuloplasty was used successfully in 17 infants less than 1 year of age, including four neonates, with critical congenital pulmonary valve stenosis, who would otherwise have required surgical intervention. This technique uses a sequential series of balloon catheters of gradually increasing size as a means of eventually crossing the very small valve orifice with a balloon catheter of adequate size to achieve successful pulmonary valvuloplasty. The initial dilatations were achieved with balloon catheters 2, 3, or 4 mm in diameter. Immediately after successful balloon valvuloplasty, the mean pulmonary systolic pressure gradient was reduced from 105 +/- 11 to 20 +/- 5 mm Hg. Percutaneous balloon pulmonary valvuloplasty can be performed safely with good results despite critical congenital pulmonary valve obstruction in severely ill infants.

Comparison of results of percutaneous balloon mitral valvotomy using single and double balloon techniques

Abstract This study compares the mitral valve area results achieved in balloon mitral valvotomy, using either a single 20-mm diameter balloon catheter, or a combination of 2 balloon catheters 18 + 20 or 20 + 20 mm in diameter.

Results of repeat percutaneous balloon valvuloplasty for pulmonary valvar restenosis

Follow-up cardiac catheterization studies were used to evaluate 105 patients who had undergone percutaneous balloon pulmonary valvuloplasty. Fifteen of those patients who had peak systolic pulmonary valve gradients greater than = 40 mm Hg at follow-up underwent repeat balloon valvuloplasty. For the initial balloon pulmonary valvuloplasty, the mean ratio of the balloon diameter to pulmonary valve annulus diameter was 0.98 +/- 0.2; at repeat valvuloplasty the mean was 1.19 +/- 0.12. The immediate post-repeat balloon valvuloplasty results showed a reduction in the peak systolic gradient from a mean of 70.2 +/- 17.8 to 29.1 +/- 19.0 mm Hg (p less than 0.001). This reduction in the gradient was maintained at a mean of 14.3 +/- 5.0 mm Hg in 8 of the 10 patients who underwent further follow-up studies. We conclude that successful repeat balloon pulmonary valvuloplasty with the use of larger sized balloons is feasible in patients who have restenosis after the initial percutaneous balloon valvuloplasty--including partial but not complete dysplasia of the pulmonary valve.

Use in children of an additional umbrella for transcatheter occlusion of residual patency of the arterial duct following initial insertion of an umbrella device

After an initial attempt to close arterial ducts by the transcatheter insertion of an umbrella device had left significant residual patency, further attempts at closure were made in 14 patients by the insertion of an additional umbrella device. The ages of the patients ranged from four to 11 years. Overall, 17 attempts were made to insert additional devices at intervals of between six to 26 months after the insertion of the first umbrella. Successful insertion of a device was achieved in two patients only at a third attempt. One patient required the insertion of a third umbrella to achieve complete occlusion of the patent duct. Complete closure of the residual patency was achieved in 13 of the 14 patients. The remaining patient has been scheduled for insertion of a third umbrella.

Comparison of results of percutaneous balloon mitral valvotomy using consecutive single (25 mm) and double (25 mm and 12 mm) balloon techniques.

Abstract This report compares the results achieved in the same patients by consecutive single balloon mitral valvotomy, using the largest commercially available balloon catheter of 25 mm diameter, and double balloon valvotomy, using 25 + 12 mm diameter balloon catheters.

Nomenclature for the use of balloon catheters.

1. Erne P, Lipkin D, Maseri A. Impaired betaadrenergic receptor and normal postreceptor responsiveness in congestive heart failure. Am J Cardiol 1988:61:1132-1134. 2. Reithmann C, Werdan K. Homologous vs. heterologous desensitization of the adenylate cyclase system in heart cells. Eur J Pharmacol 198l82:189-197.

The Future of Transcatheter Closure of Patent Ductus Arteriosus: Long-Term Study of 368 Procedures

Gross and Hubbard performed the first successful surgical closure of patent ductus arteriosus (PDA) in 1938. In 1967, Porstmann pioneered nonsurgical catheter closure of the ductus. Rashkind developed a new collapsible umbrella for this purpose in 1979. Since then, the devices used experimentally in animals and, rarely, in humans for transcatheter closure of PDA have been an occluder-counter-occluder buttoned device, by Sideris; a double-balloon detachable silicone device, by Warnecke; a nylon sack filled with silicone coated guidewires, by Magal; occluding spring coils, by Gianturco; and a shape-memory polymer, polynorbornene, by Echigo. The most long-term experience worldwide has been with a double-disk Rashkind umbrella device. We attempted PDA closure in 368 infants, children, and young adults between December 1987 and November 1993. The male-to-female ratio was 1:2.4; patient age ranged from 11 months to 45 years (median age, 5 years) and 56 patients were less than 2 years old; patient weight was 7.4 to 69 kg (mean, 18.2 ± 9.5). Successful device implantation was achieved in 98% of cases (358/368); 10 technical failures occurred. Complications included 8 embolizations to a pulmonary artery, 3 self-limited episodes of hemolysis, and 2 episodes of induced supraventricular tachy-cardia. The device was retrieved by grabber in 4 patients and by surgery in 4 patients. Follow-up included echocardiography and Doppler studies with color flow mapping. At 6 months follow-up, 23% of the patients (72/319) had a small residual shunt. The incidence was 17% (46/276) in ductus with the narrowest diameter less than 6 mm and 60% (26/43) in ductus greater than 6 mm in diameter. Successful implantation of a second occluder device was achieved in 49 patients. A third device was implanted in 2 patients who had a residual shunt with a continuous murmur at 7 months follow-up. Overall, closure occured in 90% of patients seen 6 months after initial or repeated implantation. One patient developed bacterial endarteritis and septicemia 2.5 years after deployment of a second device and died of this complication. Follow-up ranged from 9 to 75 months with a mean of 48 months with no complications. This study confirms the efficacy of PDA closure with a Rashkind occluder, especially in patients with ductal diameter of less than 6 mm. Catheter closure with the Rashkind umbrella device is a viable alternative to surgical closure of PDA in selected infants, children, and young adults.