Repair of congenital tricuspid valve abnormalities with artificial chordae tendineae

BACKGROUND

Congenital abnormalities of the tricuspid valve, including Ebstein's malformation, dysplasia, straddling, and those found in pulmonary atresia with intact septum and congenitally corrected transposition, are an uncommon cause of tricuspid regurgitation. Congenital tricuspid valve anomalies are found as a spectrum of disease in which both the leaflets and the subvalvar apparatus are often involved. Tricuspid valve repair is complicated in such patients because the chordae tendineae are often abnormally short and thick. Replacement or augmentation of chordae tendineae has proved to be a useful component of mitral valve repair. In the present report, we describe the techniques and results of chordal augmentation in the repair of congenital tricuspid valve abnormalities.

METHODS

Since July 1992, tricuspid valve repair has been performed in 5 children with severe tricuspid regurgitation secondary to congenital abnormalities of the tricuspid valve with significant chordal pathology. As a component of the repair, chordal replacement or augmentation was performed using expanded polytetrafluoroethylene suture.

RESULTS

Intraoperative and postoperative echocardiographic assessment showed good mobility of the tricuspid valve leaflets and trivial to mild tricuspid regurgitation. There were no complications and no early or late mortality. At follow-up of 34 to 60 months (median, 49 months), tricuspid valve function has remained excellent in 4 of the 5 patients. In the remaining patient, progressive regurgitation of the right ventricle to pulmonary artery allograft conduit has led to right ventricular dilatation, with a secondary increase in tricuspid regurgitation from trivial to moderate.

CONCLUSIONS

Chordal replacement or augmentation with expanded polytetrafluoroethylene suture is a useful technique in the repair of congenitally dysplastic tricuspid valves with abnormal chordal structures.

Mechanism of Mycobacterium avium complex pathogenesis

Mycobacterium avium complex (MAC) group of microorganisms are the most common opportunistic bacterial pathogens causing disseminated disease in HIV infected patients. These microorganisms are ubiquitous in nature, and are acquired by respiratory and oral routes. Pathogenesis of MAC depends on the ability of the organisms to colonize intestinal/respiratory mucosa, penetrate the protective barriers and resist intracellular killing by macrophages. Transient and reversible variation of colony morphology is one the characteristic feature of MAC that plays a significant role in the virulence and pathogenesis of these microorganisms. Isogenic colony variants of MAC differ in their virulence, susceptibility to antibiotics, stimulation of oxygen radicals and cytokines. The virulent smooth transparent colony variants are more frequently isolated from AIDS patients, more efficient in mucosal colonization, and adhere more efficiently to epithelial cells as compared to the less virulent smooth opaque variants. However, both the isogenic variants bind to the mucosal epithelial cells through the same multiple receptors. In addition, both the isogenic variants of MAC also bind to intestinal mucus through a single receptor. Study of the interaction of MAC with the host cells and characterization of MAC adhesins and host cell receptors facilitates the elucidation of the mechanisms involved in MAC pathogenesis.

Geometric mismatch of pulmonary and aortic anuli in children undergoing the Ross procedure: implications for surgical management and autograft valve function

BACKGROUND

There is often substantial mismatch between the diameters of the pulmonary and aortic anuli in young patients with systemic outflow tract disease. To implant the autologous pulmonary valve in the aortic position under such circumstances, it is necessary to adapt the geometry of the systemic outflow tract. The effects of such adaptations on autograft function in children are not well known.

METHODS

To determine factors predictive of autograft regurgitation, we analyzed 41 cases of children who have undergone the Ross procedure. The diameter of the pulmonary valve was greater (by at least 3 mm) than that of the aortic valve in 20 cases, equal (within 2 mm) in 12 cases, and less (by at least 3 mm) in nine cases, with differences ranging from +10 to -12 mm. In 12 patients with a larger pulmonary anulus, aortoventriculoplasty was used to correct the mismatch. In patients with a larger aortic anulus, the mismatch was corrected by gradual adjustment along the circumference of the autograft, rather than by tailoring of the native aortic anulus.

RESULTS

At follow-up (median 31 months), two patients had undergone reoperation on the neoaortic valve for moderate regurgitation. In the remaining 38 cases, autograft regurgitation was as follows: none or trivial in 30, mild in seven, and moderate in one. There was no correlation between regurgitation and age, geometric mismatch, or previous or concurrent procedures.

CONCLUSIONS

Subtle technical factors that may result in distortion of the valve complex are probably more important determinants of autograft regurgitation than are indication for repair, geometric mismatch, or previous or concomitant outflow tract procedures. Significant mismatch of the semilunar anuli is not a contraindication to the Ross procedure in children.

Atrioventricular valve function after single patch repair of complete atrioventricular septal defect in infancy: how early should repair be attempted?

BACKGROUND

Though repair of complete atrioventricular septal defect in infancy has become routine at most centers, it is not unusual for very young infants to be managed medically because of concerns about the fragility of the atrioventricular valve tissue.

METHODS

Since July 1992, seventy-two infants have undergone primary repair of complete atrioventricular septal defects at a median age of 3.9 months (40% < 3 months). A single-patch technique was used in all patients. The cleft was closed completely in 61 patients and partially (n = 10) or not at all (n = 1) in select patients at risk for valve stenosis. Left atrioventricular valve annuloplasty was performed in 18 patients. On the basis of transesophageal echocardiographic findings, 10 patients were returned to bypass for revision of the valve repair.

RESULTS

There was one early death in a patient with single left papillary muscle, no early reoperations, and no new permanent arrhythmias. Only three patients had moderate left atrioventricular valve regurgitation at discharge. During a median follow-up of 24 months, there was one late death and five reoperations for left atrioventricular valve regurgitation (n = 2) and/or systemic outflow obstruction (n = 4). Follow-up left atrioventricular valve regurgitation was moderate in three patients, mild in 14, and none/trace in 54. Age had no relation to postoperative atrioventricular valve regurgitation, death, or reoperation.

CONCLUSIONS

Despite concerns about fragility of valve tissue in very young patients, excellent results can be achieved with meticulous techniques. From neonates to older infants, age at repair does not influence outcome or valve function.

Left pulmonary artery kinking caused by outflow tract dilatation after transannular patch repair of tetralogy of Fallot

BACKGROUND

Stenosis of the branch pulmonary arteries after tetralogy of Fallot repair can result from several mechanisms. In patients with free pulmonary regurgitation and right ventricular dilatation after transannular patch repair, we have observed that the pulmonary outflow tract can dilate and elongate craniad and rotate to the left, resulting in kinking and obstruction of the previously normal left pulmonary artery.

METHODS

Ten patients referred for reoperation after tetralogy repair with severe pulmonary regurgitation and right ventricular outflow tract dilatation were found to have left pulmonary artery kinking. In 8 of these patients kinking was the sole or partial cause of left pulmonary artery obstruction, whereas there was no documented obstruction in the other 2. All patients underwent right ventricular outflow tract reconstruction and left pulmonary artery repair with removal of the redundancy at the kink point. Patching alone is not an effective method of repair in this condition, because the mechanism of obstruction is not corrected and the patch material can become redundant and lead to recurrent obstruction.

RESULTS

All patients underwent successful pulmonary outflow tract reconstruction. Left pulmonary artery kinking was corrected in all patients, and relief of obstruction was attained in the 8 patients with stenosis. At follow-up ranging from 9 to 58 months, no patient has evidence of recurrent left pulmonary artery stenosis.

CONCLUSIONS

Left pulmonary artery kinking should be suspected at long-term follow-up after tetralogy repair in patients with significant pulmonary regurgitation and right-sided dilatation, even if previous evaluations showed no evidence of left pulmonary arterial abnormality. Because unilateral obstruction caused by kinking may lead to asymmetric pulmonary flow, it can exacerbate pulmonary regurgitation and right ventricular dilatation, in effect accelerating the processes that led to kinking in the first place. Kinking can be relieved successfully with the techniques described in this report.

Prevalence of mental and behavioural disorders in India : a meta-analysis

A meta-analysis of 13 psychiatric epidemiological studies consisting of 33572 persons in 6550 families yielded an estimate prevalence rate of 58.2 per thousand population. Organic psychosis (prevalence rate 0.4), schizophrenia (2.7), affective disorders (12.3) contributed a rate of 15.4 for psychoses. The prevalence rate for mental retardation (6.9), epilepsy (4.4), neurotic disorders (20.7), alcohol/drug addiction (6.9; and miscellaneous group (3.9) were estimated. Higher prevalence for urban sector, females, age group of 35-44, married/widowers/divorced, lower socioeconomic status, and nuclear family members were confirmed. Epilepsy and hysteria were found significantly high in rural communities. Manic affective psychosis, mental retardation, alcohol/ drug addiction and personality disorders were significantly high in males. The findings indicated that there are 1.5 crore people suffering from severe mental disorders (psychoses) in India, and that severe diseases have higher representation at specialized as well as general hospital clinics. Among other things, the results aid in conducting morbidity surveys by more methodological approach.

Trends in the management of truncal valve insufficiency

BACKGROUND

The single semilunar valve in patients with truncus arteriosus frequently is dysplastic and dysfunctional. Truncal valve insufficiency has been associated with poor outcome. Although the management of truncal valve insufficiency has evolved over the years, approaches to this problem vary considerably and remain a serious dilemma in many cases.

METHODS

We reviewed the records of 89 patients with unrepaired truncus arteriosus and mild (n = 37), moderate (n = 33), or severe (n = 19) truncal valve insufficiency who were admitted to our institution between 1975 and 1995. Eight patients (7 neonates) with moderate or severe insufficiency died before surgical intervention, and 4 patients underwent palliative pulmonary artery banding. The remaining 77 patients underwent repair. The median age at repair was 3.2 months (range, 2 days to 15 years; 83% infants), and it decreased from 4 months between 1975 and 1985 to 1 month between 1986 and 1995. Truncal valve replacement (mechanical = 6, allograft = 4) was performed in 10 patients, and 5 patients underwent valve repair.

RESULTS

All 4 patients who underwent pulmonary artery banding died either early or late. The hospital (or 30-day) mortality rate after repair was 34% (26/77). At a median follow-up of 10 years, 11 hospital survivors had died, with overall 1- and 10-year actuarial survival rates of 56% and 48%, respectively, and poorer survival among patients with severe truncal valve insufficiency (p = 0.02). Late truncal valve replacement (n = 24) had been performed in 21 patients. Freedom from truncal valve replacement was better in patients with mild truncal insufficiency than in those with moderate or severe preoperative insufficiency (p < 0.001). Four late deaths were related directly to reoperation for truncal valve replacement or to prosthetic valve dysfunction. Three of the 4 neonates who received allograft root replacements died within 7 months of repair, and severe allograft valve insufficiency requiring replacement 1 year after operation developed in the fourth.

CONCLUSIONS

The prospects for patients with truncal valve insufficiency have been improving over time. Nevertheless, the results in patients with severe insufficiency continue to be poor.

Early and late results after repair of aortopulmonary septal defect and associated anomalies in infants <6 months of age

The Richardson classification system for aortopulmonary septal defect (APSD) includes simple defects between the ascending aorta and pulmonary trunk (type I), defects extending distally to include the origin of the right main pulmonary artery (type II), and anomalous origin of the right main pulmonary artery from the ascending aorta with no other aortopulmonary communication (type III). These are rare lesions that must be repaired in early infancy to avoid development of pulmonary vascular disease. Few reports have focused on patients with complex, associated lesions who underwent repair in early infancy. Between 1972 and 1995, 24 patients with Richardson type I (n = 11), II (n = 7), or III (n = 6) defects underwent repair at ages ranging from 2 to 172 days (median 34). Twelve patients had complex, associated anomalies, including interrupted or hypoplastic arch (n = 9), tetralogy of Fallot with (n = 1) or without (n = 1) pulmonary atresia, and transposition of the great arteries (n = 1). The most recent 7 patients were diagnosed by echocardiography without cardiac catheterization. There were no early or late deaths among the 12 patients with simple APSD. Four patients with complex, associated lesions died in the early postoperative period and another died 4 months after surgery. All 6 surviving patients with interrupted arch have had recurrent obstruction at the arch repair site, although reintervention for this reason has been performed in only 2 patients. Altogether, 6 early survivors have required reintervention, and all survivors are in New York Heart Association class I at follow-up ranging from 2 to 25 years. Thus, long-term survival after repair of APSD in early infancy is excellent. Late sequelae are likely to be related either to associated lesions or to obstruction at the APSD repair site. Almost all cases of APSD in young infants can be diagnosed and evaluated by echocardiography without catheterization.

Esophageal compression by the aorta after arterial switch

Extrinsic compression of the esophagus in children most often occurs in the presence of a congenital vascular ring. We recently operated on a patient in whom esophageal compression had developed that was severe enough to require feeding via a gastrostomy tube several years after the arterial switch operation. Aortopexy and extensive mediastinal mobilization were performed twice with transient relief and gradual return of symptoms. Almost 3 years after the first aortopexy, lasting relief was achieved by transposing the esophagus into the right side of the chest.

Intraoperative discovery of neuroblastoma in an infant with pulmonary atresia

There have been 28 previously reported cases of neuroblastoma associated with congenital heart disease. Because many of these have been defects of the conotruncal region, it has been proposed that abnormal neural crest cell migration or maturation may be a factor that links these normally disparate pathologic conditions. Most neuroblastomas in these cases have been detected at autopsy or by radiologic studies conducted in the evaluation of the cardiac anomalies. Recently, we discovered an occult posterior mediastinal neuroblastoma in a patient undergoing a unifocalization procedure for tetralogy of Fallot with pulmonary atresia and major aortopulmonary collaterals. The tumor was resected, and the patient has demonstrated no evidence of residual or metastatic neuroblastoma.

Isolated left superior vena cava to the left atrium with situs solitus and dextrocardia: extracardiac repair facilitated by juxtaposition of the atrial appendages

We describe an extremely unusual case, with isolated left superior vena cava to the left atrium, normal intracardiac anatomy, and left juxtaposition of the atrial appendages. Surgical repair was performed without cardiopulmonary bypass by anastomosing the left superior cava to the superior aspect of the right atrial appendage, and was facilitated by the ectopic location of the appendage.

Modified Damus-Kaye-Stansel procedure for single ventricle, subaortic stenosis, and arch obstruction in neonates and infants: midterm results and techniques for avoiding circulatory arrest

BACKGROUND

A modified Damus-Kaye-Stansel procedure is one of several options for palliation of single ventricle with subaortic obstruction, but results in neonates have been disappointing. In the presence of arch obstruction, this procedure is typically performed with circulatory arrest, which may contribute to neurologic insult.

METHODS

Since 1990, a modified Damus-Kaye-Stansel procedure has been performed in 14 neonates and seven infants with single ventricle and subaortic stenosis, including 15 with arch obstruction. Diagnoses were double-inlet left ventricle (n = 12), tricuspid atresia (n = 2), and other forms of hypoplastic ventricle with subaortic obstruction (n = 7). Three patients underwent concurrent bidirectional Glenn shunt. In the most recent seven patients with arch obstruction, arch repair was achieved with an end-to-side anastomosis of the descending aorta to the ascending aorta with continuous upper body perfusion.

RESULTS

One early death occurred among the 14 neonates (7%) and three among the infants, for an early mortality of 19%. At a median follow-up of 33 months, there were no late deaths or neurologic complications. Nine patients underwent subsequent bidirectional Glenn anastomosis, including three who had Fontan completion and one who later underwent conversion to a partial biventricular repair. One patient required a transplant for cardiomyopathy of unknown etiology. The remaining 12 patients are considered good candidates for Fontan completion. No patient has recurrent arch obstruction. Four patients have mild (n = 1) or trivial (n = 3) semilunar valvular regurgitation.

CONCLUSION

The modified Damus-Kaye-Stansel procedure is an effective primary palliation for single ventricle and subaortic stenosis, with or without arch obstruction. Results are especially encouraging in neonates. Arch repair can be achieved without circulatory arrest to the brain.

Update on prospects for fetal cardiovascular surgery

With progress in the field of fetal echocardiography, it has become clear that certain obstructive lesions of the heart and great vessels may progress in utero, leading to more severe disease. Prenatal intervention may mitigate this process, ultimately leading to improved outcomes for patients with certain severe congenital cardiac defects. In this review, we provide an update on the prospects for fetal cardiac intervention, with a focus on the field of fetal cardiac surgery.

The double switch procedure for anatomical repair of congenitally corrected transposition of the great arteries in infants and children

AIMS

To assess outcomes of anatomical repair (double switch procedure) in infants and children with congenitally corrected transposition of the great arteries.

METHODS AND RESULTS

Between September 1993 and August 1996, 17 patients with congenitally corrected transposition underwent surgery at UCSF. Anatomical repair was performed in 11 of these patients, at ages ranging from 4.8 months to 7.8 years (median 3.2 years). The remaining six patients did not undergo anatomical repair due to unfavourable anatomy (n = 2), prior conduit repair (n = 2), biventricular dysfunction (n = 1), and isolated complete atrioventricular block (n = 1). The 11 patients who underwent anatomical repair make up the study group for the present report. All 11 patients had a malalignment ventricular septal defect, while pulmonary outflow tract obstruction was present in nine patients and significant tricuspid valve pathology or dysfunction was present in five. Anatomical repair was achieved with a Senning (n = 7) or a Mustard (n = 4) procedure combined with an arterial switch operation plus ventricular septal defect closure (n = 4), or a Rastelli procedure with left ventricle to aortic baffle and right ventricle to pulmonary artery conduit (n = 7). There was one early death and no patients developed surgical complete atrioventricular block. At a median follow-up of 22 months, there were no late deaths. Two patients required a total of three late reoperations, and all patients were asymptomatic on no cardiac medication. Follow-up echocardiography revealed normal biventricular function in all patients.

CONCLUSIONS

Anatomical repair of corrected transposition can be achieved with low rates of early mortality and surgical heart block, and favourable mid-term results. Long-term follow-up will be necessary to determine if the double switch approach improves the natural history of corrected transposition when compared to less aggressive surgical approaches that leave the right ventricle in the systemic circulation.

Systemic venous collateral channels causing desaturation after bidirectional cavopulmonary anastomosis: evaluation and management

OBJECTIVES

We sought to characterize the frequency, anatomic details and factors associated with the development of collateral channels between the superior and inferior vena caval systems after bidirectional cavopulmonary anastomosis.

BACKGROUND

It is well known that systemic venous collateral channels often develop in patients who have undergone a classic Glenn shunt or bidirectional cavopulmonary anastomosis and that such collateral channels can lead to profound systemic desaturation. However, there have been few reports focusing on this problem.

METHODS

Fifty-four patients (median age 1.4 years) who underwent bidirectional cavopulmonary anastomosis and had preoperative and postoperative angiograms available for review were studied retrospectively. Postoperative connections between the superior and inferior vena caval systems were identified and measured. Sites of collateral origin and entry from the superior and inferior venous systems, as well as the course taken in between, were recorded.

RESULTS

At follow-up angiography performed 17 days to 46 months postoperatively, a total of 31 venous collateral channels were observed in 18 patients with a wide variety of primary morphologic diagnoses. The majority of these collateral channels (80%) originated from the brachiocephalic vein or its junction with the superior vena cava, and over half of them drained below the diaphragm. In patients who developed venous collateral channels, the mean transpulmonary pressure gradient early after bidirectional cavopulmonary anastomosis was higher (p = 0.005), and mean arterial oxygen saturation at follow-up was lower (p = 0.009). There were trends toward higher superior vena caval pressure early after the operation and at follow-up in patients with collateral channels and a higher likelihood of absent upper lobe pulmonary blood flow in these patients. Successful coll embolization of 10 collateral channels was performed in six patients, with a median increase in arterial oxygen saturation of 16%.

CONCLUSIONS

Angiographically detectable systemic venous collateral channels develop after bidirectional cavopulmonary anastomosis in a substantial number of patients (33% in the present series) with a variety of forms of a functional univentricular heart. Patients with venous collateral channels can be treated successfully with coil embolization, but the indications for embolization will depend on individual circumstances.

Hemodynamic effects of chronic prenatal ventricular pacing for the treatment of complete atrioventricular block

BACKGROUND

Increasing the heart rate of the fetus with cardiac failure caused by complete AV block (CAVB) may allow delivery of a full-term, stable neonate with preserved ventricular function. Direct fetal pacing may be a feasible method to achieve this, but the effect of pacing on the structure and function of the rapidly developing fetal heart is unknown.

METHODS AND RESULTS

CAVB was created in fetal lambs at 80% gestation by cryoablating the AV node. Epicardial ventricular pacing at 130 bpm was achieved by use of a pacemaker placed under the pectoral muscles. The fetus was returned to the uterus and allowed to continue to term. Ventricular function was assessed 1 week after birth in 7 lambs with CAVB and 10 control lambs. By use of the conductance catheter technique, the end-systolic pressure-volume relationship was determined at different heart rates, pacing conditions, and inotropic states. The contractility was not different between the two groups at their baseline heart rates and rhythms or when they were paced synchronously compared with asynchronously. Also, both groups responded significantly and similarly to inotropic manipulation, indicating preserved contractile reserve. Finally, in both groups, increased heart rates were associated with increased contractility, indicating an intact force-frequency relationship.

CONCLUSIONS

We conclude that chronic epicardial ventricular pacing is well tolerated by the fetus, can be successfully applied as a treatment for CAVB, and does not adversely affect myocardial function in the rapidly developing, immature heart.

Bilateral branch pulmonary artery obstruction due to kinking at insertion sites of bilateral ductus arteriosus

Bilateral ductus arteriosus (or ligamentum arteriosum) with right aortic arch and isolation of the left subclavian artery is a rare anomaly of the aortic arch system. We report on a patient with complete atrioventricular septal defect, right aortic arch, bilateral ligamentum arteriosum, and isolation of the left subclavian artery in whom kinking at the ductal insertions caused bilateral branch pulmonary artery obstruction. Complete surgical repair was performed when the patient was 4 months of age, and the pulmonary artery obstructions were entirely relieved by ligation and division of both ducts without pulmonary arterioplasty.

Bidirectional cavopulmonary shunt in patients with anomalies of systemic and pulmonary venous drainage

BACKGROUND

Bidirectional cavopulmonary shunt and Fontan repair are now commonly performed in patients with a variety of forms of complex single ventricle, including those with anomalies of systemic or pulmonary venous return. These anomalies are ideally dealt with during bidirectional cavopulmonary shunt, thereby minimizing the complexity of the eventual Fontan procedure.

METHODS

Between March 1990 and December 1995, 36 patients with anomalous systemic or pulmonary venous drainage underwent bidirectional cavopulmonary shunt. A combination of anomalous systemic and pulmonary venous drainage was present in 12 patients, whereas 19 patients had anomalous drainage only from the systemic circulation and 5 patients had isolated anomalies of pulmonary venous return. Visceral heterotaxy syndrome was diagnosed in 18 patients. The median age at operation was 11 months, and bidirectional cavopulmonary shunt was the first surgical procedure performed in 10 of these patients. Techniques of repair are described.

RESULTS

There were two early deaths and one bidirectional cavopulmonary shunt was taken down, for mortality and failure rates not significantly different than those for all patients undergoing bidirectional cavopulmonary shunt during this time period (n = 117). At a mean follow-up of 19.9 months, there have been three late deaths and 11 patients have undergone Fontan completion. Actuarial survival was 87% at 1 year and 81% at 3 years. Among all patients undergoing bidirectional cavopulmonary shunt during this time period, neither heterotaxy syndrome nor anomalies of systemic or pulmonary venous return were significantly associated with decreased survival or poor outcome.

CONCLUSIONS

Bidirectional cavopulmonary shunt can be performed in patients with anomalous systemic or pulmonary venous drainage, including those with visceral heterotaxy syndrome, with morbidity and mortality rates that do not differ significantly from those achieved in all patients undergoing bidirectional cavopulmonary shunt. In this report, we describe our experience with this group of patients, primarily focusing on outcomes and technical issues that pertain to the use of bidirectional cavopulmonary shunt as a preparatory procedure for the extracardiac conduit Fontan operation.

Correction of left superior vena cava draining to the left atrium using extracardiac techniques

Intraatrial rerouting techniques have been the most common approaches to correcting left superior vena caval drainage to the left atrium in patients without atrial isomerism and with no connecting vein. Although these techniques have proved reliable and successful, there are cases in which extracardiac methods for managing this form of anomalous systemic drainage may be preferable. In the present report, we describe three extracardiac approaches to the correction of left superior vena cava draining to the left atrium.

One-stage complete unifocalization in infants: when should the ventricular septal defect be closed?

BACKGROUND

The decision whether to close the ventricular septal defect at the time of unifocalization in patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collaterals may be difficult. The purpose of this study was to develop morphologic and physiologic methods to aid in deciding whether to close the ventricular septal defect in patients undergoing one-stage unifocalization.

METHODS

Between July 1992 and April 1996, 27 infants with pulmonary atresia, ventricular septal defect, and aortopulmonary collaterals were treated at our institution. Midline complete unifocalization was performed in 25 patients-the ventricular septal defect was closed in 17 and left open in eight. Two patients with severe distal collateral stenoses underwent staged unifocalization. Pulmonary artery and collateral sizes were measured from preoperative angiograms and used to calculate the indexed cross-sectional area of the total neopulmonary artery bed. An intraoperative pulmonary flow study previously validated with experiments in neonatal lambs was performed in six patients: the unifocalized neopulmonary arteries were perfused with a known flow and pulmonary artery pressures were recorded.

RESULTS

The neopulmonary artery index was greater in patients who underwent ventricular septal defect closure than in those who did not (p = 0.001), although the values did overlap. This index correlated with the postoperative right ventricular/left ventricular pressure ratio (p = 0.037). Mean pulmonary artery pressures obtained during the intraoperative flow study and after bypass were comparable.

CONCLUSION

The total neopulmonary artery index correlates with postrepair right ventricular/left ventricular pressure ratio and is useful in deciding when to close the ventricular septal defect if it is larger than 200 mm2/m2. The pulmonary flow study is helpful in deciding whether to close the ventricular septal defect in all patients.

Long-term follow-up of truncus arteriosus repaired in infancy: a twenty-year experience

BACKGROUND

There have been few reports of long-term follow-up after truncus arteriosus repair in infancy.

METHODS

A retrospective review was performed to assess long-term outcomes among 165 patients who survived the initial hospital stay after complete repair of truncus arteriosus since 1975. The median age at truncus repair over this 20-year experience was 3.5 months (range 2 days to 36 years), and 81% of patients were less than 1 year of age. Previous pulmonary artery banding had been performed in 15 patients, and two patients had undergone prior repair of interrupted aortic arch. Significant procedures performed along with truncus repair included truncal valve replacement (n = 10) or repair (n = 5) and repair of interrupted aortic arch (n = 4).

RESULTS

Patients were followed up for up to 20.4 years (median 10.5 years). Twenty-five patients were lost at cross-sectional follow-up, with a total of 67 patient-years of follow-up available on these patients. There have been 23 late deaths, eight of which occurred within 6 months of repair and 13 of which occurred within 1 year. Ten of the late deaths were related to reoperations. Actuarial survival among all hospital survivors was 90% at 5 years, 85% at 10 years, and 83% at 15 years and was essentially identical for infants alone. A significant independent risk factor for poorer long-term survival was truncus with moderate to severe truncal valve insufficiency before repair. During the follow-up period, 107 patients underwent 133 conduit reoperations. Median time to conduit reoperation was 5.5 years, and the only factor significantly associated with shorter time to conduit replacement was smaller conduit size at initial repair. In addition, 26 patients underwent 30 truncal valve replacements. Six patients required truncal valve replacement before any conduit-related reintervention, with two associated deaths. Actuarial freedom from truncal valve replacement among patients with no prerepair truncal valve insufficiency was 95% at 10 years. Actuarial freedom from truncal valve replacement was significantly lower among patients with truncal insufficiency before initial repair (63% at 10 years). At follow-up, all patients except three were in New York Heart Association functional class I.

CONCLUSIONS

Ten- to 20-year survival and functional status are excellent among infants undergoing complete repair of truncus arteriosus. Conduit replacement or revision is almost inevitably necessary in this group of patients.

Outcomes after bidirectional cavopulmonary shunt in infants less than 6 months old

OBJECTIVES

We sought to assess the results after bidirectional cavopulmonary shunt (BCPS) in infants < 6 months old and to identify risk factors for poor outcome.

BACKGROUND

Although BCPS is a well established procedure for the palliation of patients with a single-ventricle heart, there have been very few reports of outcomes after BCPS in young infants.

METHODS

Since 1990, 42 infants between 0.8 and 6.0 months of age (mean [+/-SD] 3.7 +/- 1.4) have undergone BCPS for primary (n = 16) or secondary (n = 26) palliation of tricuspid atresia (n = 13), hypoplastic left heart syndrome (n = 10) or other forms of functional single-ventricle heart (n = 19). Accessory pulmonary blood flow was included in 18 patients. Preoperative and perioperative data were gathered on retrospective review of patient records, and follow-up was conducted by means of direct physician contact or record review.

RESULTS

The overall hospital mortality rate, including that associated with reoperations, was 4.8% (2 of 42 patients). Seven patients (17%) required reoperation related to the BCPS or pulmonary blood flow in the early postoperative period: Procedures included take-down of the BCPS in four patients, with one early death, and procedures to decrease pulmonary blood flow in three patients. Age < 1 month correlated significantly with early death and with early failure of the BCPS (death or take-down). Follow-up of the 37 patients discharged with intact BCPS was obtained at a mean +/-SD of 14.3 +/- 11.3 months postoperatively, during which time three patients died (at 6.5 +/- 2.5 months). The 2-year actuarial survival rate for patients undergoing BCPS at < 6 months of age was 86%. Overall freedom from death or take-down (including early and late events) was significantly lower in patients < 2 months old than in those > 2 months old. Four patients have undergone successful Fontan completion (18.3 +/- 2.9 months postoperatively), and one patient whose BCPS was taken down subsequently underwent successful restoration of a BCPS.

CONCLUSIONS

Outcomes after BCPS in young infants are comparable to those in older infants and children. However, our current preference is to defer this procedure until after 2 months of age.

Effect of Rotablator atherectomy and adjunctive balloon angioplasty on coronary blood flow

BACKGROUND

The purpose of this study was to assess serial changes in coronary blood flow velocity before and after Rotablator atherectomy and after adjunctive percutaneous transluminal coronary angioplasty (PTCA). Since Rotablator atherectomy results in luminal enlargement by plaque pulverization and distal embolization, improvement in coronary blood flow could be attenuated despite luminal enlargement.

METHODS AND RESULTS

Intracoronary Doppler blood flow velocity measurements were obtained with a Doppler Flowire. Basal average peak velocity (bAPV), hyperemic APV (hAPV), diastolic/systolic velocity ratio (DSVR), and coronary flow reserve (CFR) were assessed before intervention, after Rotablator, and after adjunctive PTCA. Complete clinical, angiographic, and Doppler data were obtained in 22 patients. There was a small but significant difference (P = .02) in resting heart rate and mean arterial pressure before and after Rotablator and after adjunctive PTCA. Minimum lumen diameter increased from 0.8 +/- 0.1 to 1.5 +/- 0.2 to 2.0 +/- 0.1 mm (P < .001), corresponding to decreases in diameter stenosis from 72 +/- 3% to 41 +/- 4% to 36 +/- 3% (P < .001). Although bAPV, hAPV, and DSVR increased significantly (P < .001), CFR remained abnormally low in 19 of 22 patients (despite an increase from baseline to post-PTCA). hAPV > 30 cm/s was the best Doppler correlate of angiographic success.

CONCLUSIONS

Rotablator atherectomy and adjunctive PTCA significantly improve distal coronary blood flow velocity and DSVR but not CFR. Failure to normalize CFR could be secondary to parallel increases in bAPV and hAPV, "acquired" microvascular disease due to distal microembolization or spasm, and/or angiographically inapparent dissection or residual stenosis. Adjunctive PTCA contributes significantly to the overall physiological benefit of a combined procedure.