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Biomedical subjects

J E Lock

Publications and source records attributed to J E Lock.

At least 37 records · Page 2Linked to original sources
PubMed1999

Repeat balloon dilation of congenital valvar aortic stenosis: immediate results and midterm outcome.

While balloon dilation (BD) has become the initial treatment for congenital valvar aortic stenosis (CVAS) at many institutions, repeat BD for recurrent obstruction has been reported only in a few. Between January 1985 and December 1996, 298 patients (70 neonates) underwent BD, 34 of whom underwent a repeat BD without mortality. A greater proportion of neonates had a repeat BD (26% vs. 8%, P < 0.001). At repeat BD (1 day-7.5 years post initial BD), the mean peak-to-peak gradient was reduced from 67+/-24 to 36+/-16 mm Hg (P < 0.0001). Aortic regurgitation (AR) increased immediately in 26%, being moderate or more in 24%. During a mean follow-up of 5.2 years, there was one surgically related death. Of the 33 survivors, 6 had surgery for residual stenosis and/or AR. Among the remaining 27 patients, 96% were asymptomatic, the peak instantaneous aortic valve Doppler gradient was 50+/-15 mm Hg with AR absent in 8%, mild in 62%, and moderate or more in 31%. In conclusion, repeat BD is effective and without mortality. AR was at least moderate in 24% of patients immediately after a second BD. Repeat BD was more common in patients who underwent the initial BD as neonates.

Adolescent↗
PubMed1999

Combined effects of nitric oxide and oxygen during acute pulmonary vasodilator testing.

OBJECTIVES: We compared the ability of inhaled nitric oxide (NO), oxygen (O2) and nitric oxide in oxygen (NO+O2) to identify reactive pulmonary vasculature in pulmonary hypertensive patients during acute vasodilator testing at cardiac catheterization. BACKGROUND: In patients with pulmonary hypertension, decisions regarding suitability for corrective surgery, transplantation and assessment of long-term prognosis are based on results obtained during acute pulmonary vasodilator testing. METHODS: In group 1, 46 patients had hemodynamic measurements in room air (RA), 100% O2, return to RA and NO (80 parts per million [ppm] in RA). In group 2, 25 additional patients were studied in RA, 100% O2 and 80 ppm NO in oxygen (NO+O2). RESULTS: In group 1, O2 decreased pulmonary vascular resistance (PVR) (mean+/-SEM) from 17.2+/-2.1 U.m2 to 11.1+/-1.5 U.m2 (p < 0.05). Nitric oxide caused a comparable decrease from 17.8+/-2.2 U.m2 to 11.7+/-1.7 U.m2 (p < 0.05). In group 2, PVR decreased from 20.1+/-2.6 U.m2 to 14.3+/-1.9 U.m2 in O2 (p < 0.05) and further to 10.5+/-1.7 U.m2 in NO+O2 (p < 0.05). A response of 20% or more reduction in PVR was seen in 22/25 patients with NO+O2 compared with 16/25 in O2 alone (p = 0.01). CONCLUSIONS: Inhaled NO and O2 produced a similar degree of selective pulmonary vasodilation. Our data suggest that combination testing with NO + O2 provides additional pulmonary vasodilation in patients with a reactive pulmonary vascular bed in a selective, safe and expeditious fashion during cardiac catheterization. The combination of NO+O2 identifies patients with significant pulmonary vasoreactivity who might not be recognized if O2 or NO were used separately.

Administration, Inhalation↗
PubMed1998

Transcatheter management of ventricular septal rupture after myocardial infarction.

Despite improvements in surgical management of ventricular septal rupture (VSR) after myocardial infarction (MI), perioperative risk may be excessive for particular patients. Our experience with transcatheter closure of congenital ventricular septal defects led to our transcatheter attempts to close VSR after MI in patients without prior surgical repair who were thought to have prohibitive surgical risk (7), or similarly ill patients who had residual shunting after attempted surgical VSR closure (11). Of the 11 patients with postoperative residual patch-margin defects, survival (median 54 months) has not been limited by procedural success in any. Of the 7 patients without prior surgical repair, survival past hospitalization or to the present occurred in 3 patients, all of whom presented months after initial VSR. All survivors are in NYHA class II. Our experience suggests that optimal management of patients with post MI-VSR requires surgical-medical collaboration that extends surgical success to highest risk patients via catheter-based therapeutics.

Aged↗
PubMed1997

Apical muscular ventricular septal defects between the left ventricle and the right ventricular infundibulum. Diagnostic and interventional considerations.

BACKGROUND: Effective transcatheter or surgical closure of apical muscular ventricular septal defects (VSDs) requires accurate delineation of variable and often complex anatomy. These defects have generally been considered as communications between the apexes of both left and right ventricles. METHODS AND RESULTS: Among 50 consecutive patients with multiple muscular VSDs referred for transcatheter device closure between October 1987 and April 1993, a subset of 10 patients (aged 7 days to 28 years) with apical muscular VSDs shared a unique set of anatomic characteristics: (1) large and often single opening in the left ventricle; (2) multiple right ventricular openings in the anterior aspect of the apical septum; and (3) separation of the right ventricular apical region into which the VSDs open from the rest of the right ventricular inflow and outflow by prominent muscle bundles. Additional analysis of the anatomy by use of echocardiography and cineangiography showed that these muscular defects were between the left ventricular apex and right ventricular infundibular apex. In 6 patients, the transcatheter devices used to create a septum in these hearts were placed in the right ventricle, straddling muscle bundles that separated the apical VSD from the rest of the right ventricular inflow and outflow, resulting in incorporation of a portion of the right ventricular infundibular apex into the physiological left ventricle. Three patients had devices placed between the apexes of the left ventricle and the infundibulum. The defect closed spontaneously within the right ventricle in 1 patient. One patient died after surgery for tetralogy of Fallot in situs inversus. The remaining 9 patients were all clinically well at the time of their most recent follow-up visit (follow-up duration, 32 +/- 11 months). This distinct type of apical VSD was identified by echocardiography in 20 of 274 patients who were followed up clinically for muscular VSDs. CONCLUSIONS: Left ventricular-infundibular apical VSDs constitute a distinct morphological type of muscular VSD that can be distinguished by echocardiography and cineangiography. In selected cases, the infundibular apex can be separated from the rest of the right ventricular inflow and outflow to eliminate flow across these defects.

Adult↗
PubMed1997

Transcatheter fenestration dilation and/or creation in postoperative Fontan patients.

There are very few therapeutic options for severely symptomatic Fontan patients after spontaneous complete or virtual fenestration closure. Its reopening in 14 such patients led to dramatic hemodynamic improvement in most. The clinical experience with transcatheter fenestration creation and/or dilation in symptomatic Fontan patients is reported demonstrating feasibility, safety, and a novel management option for these patients.

Adolescent↗
PubMed1997

Fontan operation in five hundred consecutive patients: factors influencing early and late outcome.

OBJECTIVES: The purpose of this study was to review a large, evolving, single-center experience with the Fontan operation and to determine risk factors influencing early and late outcome. METHODS: The first 500 patients undergoing modifications of the Fontan operation at our institution were identified. Perioperative variables were recorded and a cross-sectional review of survivors was undertaken. RESULTS: The incidence of early failure decreased from 27.1% in the first quartile of the experience to 7.5% in the last quartile. In a multivariate model, the following variables were associated with an increased probability of early failure: a mean preoperative pulmonary artery pressure of 19 mm Hg or more (p < 0.001), younger age at operation (p = 0.001), heterotaxy syndrome (p = 0.03), a right-sided tricuspid valve as the only systemic atrioventricular valve (p = 0.001), pulmonary artery distortion (p = 0.04), an atriopulmonary connection originating at the right atrial body or appendage (p = 0.001), the absence of a baffle fenestration (p = 0.002), and longer cardiopulmonary bypass time (p = 0.001). An increased probability of late failure was associated with the presence of a pacemaker before the Fontan operation (p < 0.001). A morphologically left ventricle with normally related great arteries or a single right ventricle (excluding heterotaxy syndrome and hypoplastic left heart syndrome) were associated with a decreased probability of late failure (p = 0.003). CONCLUSIONS: These analyses indicate that early failure has declined over the study period and that this decline is related in part to procedural modifications. A continuing late hazard phase is associated with few patient-related variables and does not appear related to procedural variables.

Child↗
PubMed1997

Transvascular balloon dilation for neonatal critical aortic stenosis: early and midterm results.

OBJECTIVES: We evaluated our immediate and midterm (mean 4.3 years) results of balloon dilation of critical valvular aortic stenosis in 33 neonates. BACKGROUND: Balloon dilation has been used as an alternative to surgical treatment. Reports to date consist of small series (largest 16 babies) with short-term follow-up (longest 4.8 years). METHODS: From 1985 to 1991, 33 neonates had dilation at a mean age of 13 days and a mean weight of 3.4 kg. Nineteen of the neonates (58%) were intubated and received prostaglandins, and 94% had other cardiac abnormalities. RESULTS: The dilation was completed retrograde in 31 of the neonates (umbilical artery in 11 and femoral artery in 20) and anterograde (femoral vein) in 2. The average immediate peak gradient and left ventricular end-diastolic pressure reductions were 54% and 20%, respectively. The overall mortality rate was 12% (three early deaths and one late). All 20 neonates dilated through a femoral artery initially had pulse loss with restoration in 35% after thrombolytic therapy. At 8.3 years, survival and freedom of reintervention probability rates were 88% and 64%, respectively. At mean 4.3 years of follow-up, 83% of the survivors were asymptomatic; Doppler study revealed a maximal instantaneous gradient < 50 mm Hg in 65% of neonates and significant aortic regurgitation in 14%. CONCLUSIONS: This study confirms that dilation of aortic stenosis in neonates is effective; reintervention (mostly redilation) is frequent (40%); and midterm survival is encouraging (88%).

Aortic Valve Stenosis↗
PubMed1997

Clinical course and hemodynamic observations after supraannular mitral valve replacement in infants and children.

OBJECTIVES: We report the clinical course and unique hemodynamic findings after placement of a supraannular mitral valve prosthesis. BACKGROUND: Children with symptomatic mitral valve disease whose annulus is too small for the smallest prosthesis are difficult to manage. One option is valve replacement with a prosthesis positioned entirely within the left atrium (LA). METHODS: We reviewed 17 patients (median age 10 months) with symptomatic mitral valve disease who underwent placement of a supraannular valve prosthesis between 1980 and 1994. RESULTS: The actuarial survival rates were 88% at 1 month and 71%, 62% and 53% at 1, 2 and 10 years, respectively. Preoperative hemodynamic data (mean +/- SD)) compared with those after placement of the supraannular mitral prosthesis were as follows: "a" wave to left ventricular end-diastolic pressure gradient 17 +/- 5 versus 4 +/- 4 mm Hg (p = 0.003), mean LA pressure 25 +/- 6 versus 20 +/- 6 mm Hg (p = 0.07), "a" wave 30 +/- 6 versus 19 +/- 5 mm Hg (p = 0.006), "v" wave 28 +/- 5 versus 30 +/- 9 mm Hg (p = 0.31), mean pulmonary artery pressure 54 +/- 19 versus 42 +/- 15 mm Hg (p = 0.07) and left ventricular end-diastolic pressure 14 +/- 5 versus 16 +/- 4 mm Hg (p = 0.12). CONCLUSIONS: Supraannular mitral valve replacement provides relief of mitral stenosis or mitral regurgitation. However, LA to left ventricular early diastolic gradients with large atrial "v" waves contribute to elevated mean LA pressures in the absence of prosthetic valve obstruction or regurgitation. As a result of this unexpected finding, associated left heart obstructive lesions and pulmonary and left ventricular end-diastolic hypertension, the outlook remains poor.

Child, Preschool↗
PubMed1997

Multipolar endocardial mapping of the right heart using a basket catheter: acute and chronic animal studies.

The development of catheter-based ablative techniques for primary atrial and ventricular arrhythmias is likely to be assisted by improved techniques for systematic endocardial activation sequence mapping. RA mapping using a multielectrode basket catheter has been shown to be feasible with minimal acute toxicity in a prior study. The objectives of the current study are to investigate: (1) the utility of the basket catheter for mapping RV activation; and (2) the evolution of acute endocardial lesions produced by basket catheter use in both the RA and RV over 4-8 weeks time. A flexible, 5-spoke basket catheter bearing 25 electrode pairs was placed in the RA (n = 9) or the RV (n = 13) in 22 juvenile sheep (22-56 kg). The catheter was deployed for 0.1-4.1 hr (RA) and 0.3-3.9 hr (RV). In 20 of these 22 animals, 32 recordings were made of filtered (30-250 Hz) bipolar electrograms and surface ECG. Electrograms were timed and used to construct activation sequences based on a schematic of catheter geometry. Hearts were examined either acutely (4 RA and 9 RV studies) or 4-8 weeks after the procedure (5 RA and 4 RV studies). One animal undergoing RA placement had an air embolism resulting in cardiac arrest immediately prior to basket placement; all other animals were stable during placement. RA electrograms of sufficient quality to determine activation time were recorded from 82% of pairs in RA maps, and RV electrograms from 89% of pairs in RV maps. Mean activation sequence duration in RV was 16 ms versus 47 ms in RA (P < 0.0001), making construction of RV maps more difficult. Acute postmortem studies of RV placement revealed a silent apical RV puncture in one animal. Superficial abrasion or ecchymosis of RV endocardium and/or tricuspid valve were noted in six animals. Postmortem exams in both RA and RV chronic studies showed healed endocardial lesions, with only superficial scarring. Rapid RV activation mapping using a basket catheter is feasible, but requires precision recording techniques. Endocardial abrasions produced in lambs both by RA and RV placement of the catheter are healed in < 4-8 weeks, with trivial residua. The multielectrode basket catheter may be applicable to the mapping of tachycardias originating in or involving the right ventricle.

Animals↗
PubMed1996

Outcome of patients with ectopia cordis and significant intracardiac defects.

BACKGROUND: Previous reports suggest a poor prognosis for patients with ectopia cordis and significant congenital heart disease. METHODS AND RESULTS: To determine the outcome of affected patients in a recent medical and surgical era, we reviewed the clinical course, echocardiograms, catheterization data, and operative reports of all patients with ectopia cordis and significant heart disease encountered at Children's Hospital from 1982 to the present. We identified 13 patients with conotruncal defects and either thoracic (TEC, n = 4) or thoracoabdominal (TAEC, n = 9) ectopia cordis. Diagnosis was established in utero in 6, with termination of pregnancy in 2 and death before transfer to Children's Hospital in 1. Of 10 patients postnatally managed at Children's Hospital, 4 of 8 with TAEC and 1 of 2 with TEC survived beyond infancy, with an age at most recent follow-up of 3.5 to 9.8 years. All 5 survivors had procedures as neonates to provide skin coverage over the midline defect and heart, with concomitant repair of a small omphalocele in 4. Three underwent successful surgical repair of the cardiac defect, including ventricular septal defect closure for double-outlet right ventricle (9 months), repair of tetralogy of Fallot with pulmonary atresia (2.6 years), and repair of double-outlet right ventricle, pulmonary stenosis, and total anomalous pulmonary venous connection to the coronary sinus (3.3 years). Two other patients with TAEC, conoventricular defects, and hypoplastic left ventricle underwent single-ventricle palliation. One patient, at 4 years of age underwent a right cavopulmonary anastomosis and intra-atrial coronary sinus-to-right superior vena cava baffle. The second patient had a modified Fontan procedure. None of the 5 survivors had significant extrathoracic defects, whereas all 3 who died by 3 weeks of age had both a large omphalocele and pulmonary hypoplasia. Two infants with pentalogy of Cantrell, 1 with a large omphalocele, died of fungal sepsis by 5 weeks of age, and 1 other died intraoperatively after repair of pulmonary venous confluence obstruction and right Blalock-Taussig shunt placement. CONCLUSIONS: Our experience indicates that patients with TEC and TAEC and significant intracardiac defects, in the absence of significant extracardiac defects, can survive beyond early infancy and undergo successful cardiac repair or more definitive palliation for single-ventricle physiology.

Child↗
PubMed1996

Isolated peripheral pulmonary artery stenoses in the adult.

BACKGROUND: Isolated peripheral pulmonary artery stenosis (PPS) in the adult is rare and frequently unsuspected. We review in this article our experience with 12 adult patients with isolated PPS, half of whom had been previously diagnosed with chronic pulmonary thromboembolic disease. METHODS AND RESULTS: The presentation, evolution, and management of 12 adults with isolated PPS, 17 to 51 years of age (mean, 36.2 +/- 9.7 years), were evaluated. Presenting symptoms were dyspnea and fatigue. Three patients had New York Heart Association (NYHA) functional class III or greater. Lung perfusion scans revealed multiple segmental abnormalities in flow distribution in all patients. Oxygen desaturation at rest was present in 4 patients. At catheterization, right ventricular (RV) pressure was suprasystemic in 2 patients, systemic in 1, and more than half-systemic in 7. All had multiple bilateral non-uniform stenoses in segmental and subsegmental arteries. Balloon pulmonary angioplasty (BPA) to decrease RV hypertension and improve pulmonary flow distribution was performed in 11 patients. After BPA, vessel diameter increased > 50% in 10 patients, distal pulmonary artery pressure increased > or = 30% in 6, and RV pressure decreased > 30% in 5. One patient died shortly after BPA as a result of pulmonary hemorrhage. Immediate procedural success was achieved in 9 of 11 patients. At a mean follow-up period of 52 +/- 32 months, 7 patients had sustained symptomatic improvement (NYHA class I-II). CONCLUSIONS: We describe a severe syndrome of isolated PPS in the adult that mimics chronic pulmonary thromboembolic disease. Pulmonary hemodynamics and angiography are required for definitive diagnosis. BPA may offer these patients successful short-term reduction in RV hypertension and alleviation of symptomatology.

Adolescent↗
PubMed1996

Midterm results of balloon dilation of congenital aortic stenosis: predictors of success.

OBJECTIVES: We evaluated patient and procedural characteristics that influence the midterm success of balloon dilation of congenital aortic stenosis. BACKGROUND: Balloon dilation is a new treatment for congenital aortic stenosis. Factors that influence midterm success are unknown. METHODS: We performed a retrospective review of 148 children >1 month old who underwent balloon dilation for aortic stenosis. RESULTS: Balloon dilation was successful in 87% of patients, with a procedural mortality rate of 0.7%. The average immediate peak to peak gradient reduction was 56.4 +/- 19.9% (mean +/- SD). Prior valvotomy was the only factor that significantly reduced the immediate gradient reduction after dilation (47.1 +/- 21.8% vs. 57.8 +/- 19.6%, p < 0.01). Survival after dilation was 95% at 8 years. Seventy-five percent of patients were free of repeat intervention 4 years after dilation, whereas 50% remained free of repeat intervention at 8 years. Asymmetrically thick valve leaflets (risk ratio [RR] 0.17, p < 0.01) and prior aortic valvotomy (RR 0.35, p = 0.02) decreased the risk of repeat intervention. Aortic regurgitation grade > or = 3 (RR 4.27, p = 0.04) and residual gradient after dilation (RR 1.63 for 10 mm Hg, p < 0.01) increased the risk. CONCLUSIONS: The 8-year survival rate after dilation was 95% with 50% of patients free of repeat intervention. Factors that increased the risk for repeat intervention included symmetrically thin or thick aortic valve leaflets, regurgitation grade > or = 3 after dilation and a high residual gradient after dilation. The incidence of repeat intervention after dilation was high owing to its palliative nature.

Adolescent↗
PubMed1996

Tetralogy of Fallot with diminutive pulmonary arteries: preoperative pulmonary valve dilation and transcatheter rehabilitation of pulmonary arteries.

OBJECTIVES: This study sought to determine the results of a novel transcatheter management approach in tetralogy of Fallot with diminutive pulmonary arteries. BACKGROUND: Tetralogy of Fallot with diminutive pulmonary arteries and severe pulmonary stenosis is rare and resembles tetralogy of Fallot with pulmonary atresia: There is a high incidence of aortopulmonary collateral channels, arborization abnormalities, stenoses and need for multiple operations. Because a combined catheter-surgery approach facilitates repair in these patients, such an approach may benefit those with diminutive pulmonary arteries and pulmonary stenosis. METHODS: Clinical, catheterization and surgical data were studied retrospectively for 10 such patients undergoing preoperative pulmonary valve balloon dilation, among other transcatheter interventions, from January 1989 to January 1995. RESULTS: Initially, the Nakata index ranged from 20 to 98 mm2/m2 (mean 67 +/- 28 mm2/m2). The pulmonary valve was first balloon dilated (mean balloon/annulus 1.5 +/- 0.3), and the mean initial valve annulus Z score (-4.0 +/- 1) increased to -33 +/- 1.1 (p < 0.01) Other interventions included branch pulmonary artery balloon dilation (7 patients, 23 vessels) and coil embolization of aortopulmonary collateral channels (8 patients, 31 collateral channels). At preoperative follow-up catheterization, the mean pulmonary annulus Z score was -3.1 +/- 0.7, and the Nakata index increased to 143 +/- 84 mm2/m2 (p < 0.03). All patients underwent complete surgical repair successfully. At a mean follow-up period of 2.6 +/- 2 years, right ventricular pressure was < 70% systemic in all patients and < 50% systemic in seven. CONCLUSIONS: In patients with tetralogy of Fallot, severe pulmonary stenosis and diminutive pulmonary arteries, initial pulmonary valve balloon dilation increases the annulus Z score and anterograde pulmonary blood flow and facilities simultaneous coiling of aortopulmonary collateral channels and access for branch pulmonary artery dilation, all of which results in pulmonary artery growth, simplifying surgical management.

Abnormalities, Multiple↗
PubMed1996

Conversion of modified Fontan procedure to lateral atrial tunnel cavopulmonary anastomosis.

After modified Fontan procedures with atriopulmonary anastomoses or right atrium-right ventricle conduits, some patients have progressive exercise intolerance, effusions, arrhythmias, or protein-losing enteropathy. Theoretic advantages of a lateral atrial tunnel cavopulmonary anastomosis and published clinical results suggest that conversion of other Fontan procedures to the lateral atrial tunnel may afford clinical improvement for some patients. Eight patients (8 to 25 years old) with tricuspid atresia (n =4), double-inlet left ventricle (n = 3), and double-outlet right ventricle (n=1) underwent conversion to a lateral tunnel procedure between December 1990 and November 1994. An arbitrary clinical score was assigned before the lateral tunnel procedure and at follow-up. Before conversion, patients had decreased exercise tolerance (n = 8), arrhythmias (n = 6), effusions (n = 4), and protein-losing enteropathy (n = 8). At catheterization, all had a low cardiac index (1.9 +/- 0.7 L x min(-1) x M(-2), five had elevated pulmonary vascular resistance (>3 Wood units), and three had right pulmonary venous return obstruction by compression of an enlarged right atrium. Fenestrated lateral tunnel construction was undertaken 7.3 +/- 3.6 years after atriopulmonary anastomosis, with one early death related to low cardiac output. After the lateral tunnel procedure, two patients had no clinical improvement (no change in clinical score) but five patients had either marked or partial improvement. The right pulmonary vein compression present in three patients was resolved after conversion. The mean clinical scores improved from 4.5 +/- 1 to 3.0 +/- 2 (p < 0.04). In conclusion, conversion to a lateral tunnel procedure led to clinical improvement in five of eight patients at short-term follow-up and may be particularly indicated for patients with giant right atria or pulmonary vein compression who have symptoms. Pulmonary vein compression should be looked for in patients after modified Fontan procedures and can be relieved by conversion to the lateral tunnel procedure.

Adolescent↗
PubMed1995

Prolongation of RV-PA conduit life span by percutaneous stent implantation. Intermediate-term results.

BACKGROUND: Right ventricle-to-pulmonary artery (RV-PA) homografts and bioprosthetic conduits are commonly used to palliate various types of complex congenital heart disease. These conduits frequently develop progressive obstruction and require surgical replacement. This report reviews our experience implanting balloon-expandable stents to relieve conduit obstruction and delay reoperation. METHODS AND RESULTS: A retrospective review identified 44 patients who underwent placement of 48 stents in obstructed RV-PA conduits. Median patient age was 6.9 years (range, 7 months to 30 years), and median follow-up time was 14.2 months (range, 0 to 48 months). Stent implantation initially decreased the RV-PA pressure gradient from 61.0 +/- 16.9 to 29.7 +/- 11.9 mm Hg (P < or = .001) and the right ventricular-to-systemic arterial pressure ratio from 0.92 +/- 0.17 to 0.63 +/- 0.20 (P < or = .001). The diameter of the stenotic region expanded from 9.3 +/- 3.5 to 12.3 +/- 3.3 mm in the anteroposterior view (P < or = .001) and from 6.6 +/- 2.9 to 10.9 +/- 2.5 mm in the lateral view (P < or = .001). During the follow-up period, 2 patients had their stents redilated, 7 had additional conduit stents deployed, and 14 underwent surgical replacement of their conduits. Actuarial freedom from conduit reoperation was 65% at 30 months postprocedure. Seven patients were found to have fractured stents on follow-up, suggesting an important role for external compressive forces in conduit failure. Recatheterization in 16 patients a median of 11.8 months (3 to 48 months) postprocedure demonstrated hemodynamic evidence of recurrent obstruction despite sustained enlargement at the previously stented sites. Complications included stent displacement (n = 1), bacterial endocarditis (n = 1), and false aneurysm formation (n = 1). One patient died awaiting conduit replacement surgery. CONCLUSIONS: Stent implantation in obstructed RV-PA conduits results in significant immediate hemodynamic and angiographic improvement. In a subgroup of patients, the procedure prolongs conduit life span by several years and increases the interval between conduit reoperations. Recurrent obstruction is caused by external compression and progressive stenosis outside the stented region.

Bioprosthesis↗
PubMed1995

Hepatic venous blood and the development of pulmonary arteriovenous malformations in congenital heart disease.

BACKGROUND: Pulmonary arteriovenous malformations (PAVMs) are a known complication after some types of cavopulmonary anastomoses (CVPAs). Their cause is unknown, but they may be related to the absence of pulsatile flow or the presence or absence of circulating factors. These PAVMs are diffuse and are presumed to be progressive and irreversible. METHODS AND RESULTS: All patients with congenital heart disease (CHD) seen at Children's Hospital, Boston, Mass, between 1970 and 1993 were reviewed. We report on the 10 patients with CHD who were found to have developed PAVMs, as diagnosed by cardiac catheterization. Diagnoses included heterotaxy syndrome/polysplenia, with interrupted inferior vena cava and hepatic veins draining to the right atrium (n = 6); heterotaxy/asplenia (n = 1); corrected transposition with pulmonary stenosis (n = 1); and biliary atresia and associated CHD (n = 2). PAVMs were diagnosed 0.1 to 7.0 years (median, 3.5 years) after creation of a CVPA that resulted in exclusion of hepatic venous flow from one or both lungs in 8 of the 10 patients; the remaining 2 patients had normal drainage of hepatic veins to the lungs but had biliary atresia. In all, the common anatomic feature was the exclusion of normal hepatic venous return from the affected pulmonary arterial circulation. All patients with interrupted inferior vena cava, azygous continuation to the superior vena cava, and hepatic veins draining to the right atrium (polysplenia syndrome) were reviewed to determine the incidence of PAVMs in those with CVPA (ie, hepatic venous flow excluded from the pulmonary arteries) and without CVPA. Six of 28 (21%) of those with versus 1 of 56 (1.8%) of those without CVPA developed PAVMs (P = .004). The 1 patient without CVPA who had PAVMs also had biliary atresia. Among patients with CVPA, the probability of developing PAVMs was 15% and 28% at 3 and 5 years, respectively, after CVPA. The histological and angiographic appearances of PAVMs after CVPA are similar to those seen in PAVMs associated with hepatic cirrhosis. CONCLUSIONS: We postulate that PAVMs after CVPA are related to the diversion of normal hepatic venous flow from the pulmonary circulation. In this sense, these PAVMs may be analogous to those associated with liver disease, which have been found to resolve after liver transplantation. Redirection of hepatic flow to the pulmonary bed in some patients with CHD and PAVMs may lead to reversibility of the PAVMs.

Adult↗