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Biomedical subjects

V M Reddy

Publications and source records attributed to V M Reddy.

At least 73 records · Page 4Linked to original sources
PubMed1998

Partial biventricular repair for complex congenital heart defects: an intermediate option for complicated anatomy or functionally borderline right complex heart.

BACKGROUND: Partial biventricular repair consists of bidirectional cavopulmonary anastomosis in the presence of separated systemic and pulmonary circulations, with antegrade flow of inferior caval return through an intact or reconstructed pulmonary outflow tract. This versatile procedure may be used as a definitive repair for patients with a functional right heart complex incapable of supporting an entire cardiac output or in patients with complicated anatomy. METHODS: From July 1992 to April 1997, 23 patients (median age 5.2 years) underwent partial biventricular repair. In 15 of these cases the entire repair, including bidirectional cavopulmonary anastomosis, intracardiac repair, and right ventricular outflow reconstruction, was performed as a planned procedure at our institution. The other eight patients had previously been placed on a Fontan track and had undergone bidirectional cavopulmonary anastomosis; their circulations were converted to a partial biventricular circulation. RESULTS: There were no early deaths. Complete atrioventricular block developed in two patients with straddling tricuspid valve. At a median follow-up of 17 months, there were no late deaths and three patients had undergone reintervention. Partitioning of the pulmonary arteries to create a classic Glenn anastomosis with antegrade flow to the left lung was performed in one case; another patient underwent an atrial septectomy, and the third patient required revision of tricuspid valve repair. All patients are in New York Heart Association functional class I. CONCLUSIONS: Partial biventricular repair is a versatile strategy that can be used to manage a variety of forms of complex congenital heart disease. Cases for which the repair is useful include those in which complete biventricular repair is unlikely to be achieved because of limited size or function of the right side of the heart and those in which a patient with a ventricle capable of supporting inferior vena caval return was previously placed on a Fontan track.

Abnormalities, Multiple↗
PubMed1998

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.

Blood Flow Velocity↗
PubMed1998

Rare forms of isolation of the subclavian artery: echocardiographic diagnosis and surgical considerations.

Isolation of the subclavian artery is an unusual anomaly in which the subclavian artery arises not from the aortic arch but from a pulmonary artery via an arterial duct. Such isolation most often occurs with a right aortic arch, and in lesions frequently associated with a right arch, such as tetralogy of Fallot. Since 1994, we have undertaken surgery in four young infants with isolated subclavian arteries and unusual associated anomalies, including one with atrioventricular septal defect and common valvar orifice, two with interruption of a left aortic arch and one with interruption of a right aortic arch. In both patients with interrupted left arch, the isolated subclavian artery was diagnosed preoperatively by echocardiography. We emphasize the significant surgical issues.

Aortography↗
PubMed1998

Atrioventricular septal defect with common valvar orifice and tetralogy of Fallot revisited: making a case for primary repair in infancy.

Atrioventricular septal defect with common valvar orifice and tetralogy of Fallot is a rare combination of congenital cardiac anomalies. Approaches to this lesion have tended to emphasize either staged repair or complete repair beyond infancy. Between July 1992 and August 1997, nine patients underwent repair of complete atrioventricular septal defect with tetralogy of Fallot. One patient, aged 9.6 years at the time of repair, had previously undergone construction of a modified Blalock-Taussig shunt. Primary complete repair was performed in the other 8 patients at ages ranging from 2.5 to 16 months (median 4.6 months), and all but one were infants. All patients had a Rastelli type C defect, a single ventricular septal defect with inlet and outlet components, and malalignment of the muscular outlet septum with subpulmonary stenosis. A single patch technique, with closure of the zone of apposition ('cleft') in the left atrioventricular valve, was used in all eight patients undergoing primary repair, while a double patch was employed in the previously palliated older patient. In all cases of repair using a single patch, the anterosuperior bridging leaflet was divided obliquely to the right, following the malaligned outlet septum, in order to avoid subaortic obstruction. Repair of the right ventricular outflow tract included infundibular myectomy in eight, pulmonary valvotomy in four, infundibular or transannular patching in three and one, respectively, and reconstruction with a valved allograft conduit in two patients. There was no early mortality or significant morbidity. At a median follow-up of 45 months, there had been one death related to non-cardiac causes and no reinterventions. Left atrioventricular valvar regurgitation was moderate or mild in two patients, and right atrioventricular valvar regurgitation was mild in one patient. No patient had more than mild pulmonary regurgitation or a gradient across the right ventricular outflow tract in excess of 18 mm Hg. Our results demonstrate that primary repair of atrioventricular septal defect with tetralogy of Fallot can be performed with excellent early and mid-term results in young infants. Although it has been suggested that a technique utilizing oblique division of the anterosuperior bridging leaflet may lead to high rates of atrioventricular valvar regurgitation, medium-term atrioventricular valvar function in the present cohort of patients has been excellent.

Adolescent↗
PubMed1997

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.

Abnormalities, Multiple↗
PubMed1997

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.

Animals↗
PubMed1997

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.

Aged↗
PubMed1997

Post-cardiopulmonary bypass pulmonary hypertension in lambs with increased pulmonary blood flow. A role for endothelin 1.

BACKGROUND: After cardiopulmonary bypass (CPB), pulmonary hypertension and its associated increased vascular reactivity are a major source of morbidity, particularly for children with increased pulmonary blood flow. Although post-CPB pulmonary hypertension is well described, its mechanisms remain incompletely understood. Plasma levels of endothelin 1. a potent vasoactive substance implicated in pulmonary hypertension, are increased after CPB. The purpose of the present study was threefold: to characterize the changes in pulmonary vascular resistance and vascular reactivity induced by hypothermic CPB; to investigate the effects of preexisting increased pulmonary blood flow on these changes; and to better define the role of endothelin 1 in the pathogenesis of post-CPB pulmonary hypertension. METHODS AND RESULTS: Vascular pressures and blood flows were monitored in 14 1-month-old lambs with increased pulmonary blood flow (after in utero placement of an aortopulmonary shunt) and 6 age-matched control lambs. During the 2-hour study period after 105.3 +/- 20.6 minutes of hypothermic CPB the increase in pulmonary vascular resistance was significantly augmented in lambs with increased pulmonary blood flow compared with control lambs (P < .05). Pretreatment with PD 145065 (a nonselective endothelin receptor blocker; 50 micrograms.kg-1.min-1) completely blocked this increase in pulmonary vascular resistance and blocked the increase in pulmonary vascular resistance in response to acute alveolar hypoxia after CPB (96.3 +/- 88.5% versus -9.7 +/- 16.4%; P < .05). Plasma endothelin 1 levels increased after CPB in all lambs. CONCLUSIONS: Preexisting increased pulmonary blood flow alters the response of the pulmonary circulation to hypothermic CPB; the increase in pulmonary vascular resistance induced by CPB is augmented in lambs with increased pulmonary blood flow. Pretreatment with endothelin 1 receptor blockers eliminated the increase in pulmonary vascular resistance and the pulmonary vasoconstricting response to alveolar hypoxia, suggesting a role for endothelin 1 in post-CPB pulmonary hypertension. Endothelin 1 receptor blockers may decrease morbidity in children at risk for pulmonary hypertension after surgical repair with CPB and warrants further study.

Animals↗
PubMed1997

Exogenous Neisseria meningitidis endophthalmitis.

PURPOSE: To report a case of Neisseria meningitidis endophthalmitis in association with a leaking filtering bleb and to consider antibiotic prophylaxis of those people with whom the patient had contact. METHOD: We treated an 81-year-old man who had a chronic, leaking filtering bleb and who developed exogenous N meningitidis endophthalmitis. RESULT: N meningitidis endophthalmitis was controlled with antibiotic therapy. Antibiotic prophylaxis for those with whom the patient had contact was not recommended. CONCLUSION: In this case, the N meningitidis strain was not considered invasive because the bacteria apparently entered the eye through a leaky filtering bleb and not through the bloodstream. Recovery of noninvasive N meningitidis does not require prophylaxis for patient contacts. In cases of endogenous or idiopathic N meningitidis endophthalmitis, antibiotic prophylaxis of close patient contacts may be warranted.

Aged↗
PubMed1997

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.

Actuarial Analysis↗
PubMed1997

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.

Aorta, Thoracic↗
PubMed1997

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.

Female↗
PubMed1997

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.

Anastomosis, Surgical↗
PubMed1997

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.

Anastomosis, Surgical↗
PubMed1997

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.

Adolescent↗
PubMed1997

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.

Abnormalities, Multiple↗