Biomedical subjects
Publications and source records attributed to Panangipalli Venugopal.
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Two patients with anomalous right subclavian artery proximal to aortic coarctation are reported for their rarity. The embryological basis and surgical implications are briefly discussed. The major surgical implication of this anomaly relates to the risk of spinal cord ischemia and in these cases, the repair was performed safely.
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BACKGROUND: This study was designed to prospectively investigate the effects of total or partial chordal-sparing and chordal-nonsparing mitral valve replacement (MVR) procedures on regional and global ventricular function in a rheumatic population using sequential multiple-gated acquisition scan. METHODS: One hundred five consecutive patients undergoing different techniques of chordal preservation procedures during MVR are included in this prospective study. Fifteen patients had complete excision of the chordopapillary apparatus (group 1), 34 had total chordal preservation (group 2), and 56 had preservation of the posterior chordopapillary apparatus (group 3). Radionuclide-derived left ventricular ejection fraction (LVEF) and regional wall motion (RWM) studies on 99 survivors were performed preoperatively, at discharge, at 1 year, and at 2 years. RESULTS: At discharge, there was a decline in LVEF in all the 3 groups. Statistically significant improvement in ejection fraction occurred in the chordal preservation groups (2 and 3) (P < .05) as compared with the nonchordal group immediately and late postoperatively. Only the total chordal group (2) demonstrated complete recovery of LVEF by 2 years postoperatively. Significant and persistent RWM abnormalities were noted in both the nonchordal and posterior chordal groups. CONCLUSIONS: We conclude that complete retention of the chordopapillary apparatus during MVR provides superior results compared with nonchordal and partial chordal preservation in terms of preservation of LVEF and reduced incidence of abnormal postoperative RWM.
BACKGROUND: This study was designed to compare the outcomes after total versus partial pericardiectomy clinically, echocardiographically, and hemodynamically. METHODS: Three hundred ninety-five patients undergoing pericardiectomy for constrictive pericarditis between January 1985 and December 2004 were studied. Age was 10 months to 71 years (mean, 25.1 +/- 13.4 years). Three hundred thirty-eight patients (85.6%) underwent total pericardiectomy (group I), and 57 patients (14.4%) underwent partial pericardiectomy (group II). RESULTS: Operative and late mortality rates were 7.6% and 4.9%, respectively. Preoperative high right atrial pressure, hyperbilirubinemia, renal dysfunction, atrial fibrillation, pericardial calcification, thoracotomy approach, and partial pericardiectomy were significant risk factors for death. The risk of death was 4.5 times higher (95% confidence interval: 2.05 to 9.75) in patients undergoing partial pericardiectomy. At a mean follow-up of 17.9 +/- 0.3 years (95% confidence interval: 17.3 to 18.6), actuarial survival was 83.8% +/- 0.04% in group I and 73.9% +/- 0.06% in group II (p = 0.004). At their last follow-up, 96.3% survivors of group I and 79.1% survivors of group II were in New York Heart Association class I/II (p < 0.001). CONCLUSIONS: Total pericardiectomy is associated with lower perioperative and late mortality, and confers significant long-term advantage by providing superior hemodynamics that appear to be independent of the etiology of constrictive pericarditis.
BACKGROUND: This study was designed to validate the diagnostic accuracy of magnetic resonance imaging (MRI) in evaluating biventricular ejection fraction and to quantify pulmonary regurgitant fraction (PRF) in patients after repair of tetralogy of Fallot. METHODS: Two hundred and eighty survivors of repaired tetralogy of Fallot aged 42 months to 40 years (mean, 142.2 +/- 85.3 months) underwent cardiac MRI, first-pass and gated radionuclide ventriculography (RNV) for the assessment of biventricular function, and PRF after 89.26 +/- 42.40 months. The receiver operating characteristic curve analysis was done to quantify the diagnostic accuracy of MRI. RESULTS: There was statistically significant agreement between MRI and RNV in evaluating right and left ventricular function. An MRI-derived right ventricular ejection fraction 47.2% or greater than normal was associated with a sensitivity of 92.3% and a specificity of 92.3%. An MRI-derived left ventricular ejection fraction 53.9% or greater than normal was associated with a sensitivity of 93.2% and a specificity of 93.3%. Area analysis indicated that 97.34% (standard error [SE] = 0.0118) and 98.56% (SE = 0.0052) of the time values of right and left ventricular ejection fraction were higher for patients with normal right and left ventricular functions, respectively, compared with abnormal. There was a strong agreement between velocity-encoded and stroke volume-derived PRF [(r = 0.886, p < 0.001; d = 2.62 +/- 1.12, p < 0.0001; r' = 0.121, p = 0.051; b = 0.96 (SE = 0.012); p < 0.0001; ICC = 0.98, p < 0.0001). Higher PRF was associated with increased indexed right ventricular dimensions and inversely correlated with biventricular ejection fractions. CONCLUSIONS: The MRI-derived ejection fraction values predictably separate patients with normal ventricular function from abnormal. Velocity-encoded MRI can accurately quantitate PRF in tetralogy of Fallot.
BACKGROUND: The aim of this study was to analyze the feasibility and early results of transatrial total correction of tetralogy of Fallot (TOF). METHODS: Of the 860 patients undergoing total correction for TOF between January 2000 and July 2005, 334 patients were considered morphologically suitable for transatrial total correction. The ventricular septal defect (VSD) closure, infundibular resection, and pulmonary valvotomy were performed through the right atrium without a right ventriculotomy. Age ranged from 6 months to 40 years (median, 2.8 years), and weight ranged from 5.5 to 70 kg (median, 14 kg). RESULTS: Peroperatively, 34 patients required right ventriculotomy and transannular patch; hence, they were excluded from the study. In addition, pulmonary arteriotomy was required in 71 patients (22.9%). There were 4 hospital deaths. There were 4 early reoperations (residual/additional VSD in 3 and tricuspid regurgitation in 1). Two patients had complete heart block requiring permanent pacemaker. Echocardiography at discharge showed a peak right ventricular outflow tract gradient of 20 +/- 5.2 mm Hg. Mean follow-up was 26.8 +/- 4.2 months (range, 1 to 52 months). The right ventricular outflow tract gradients reduced to 13 +/- 4.2 mm Hg after a mean interval of 18.8 +/- 5.2 months. Follow-up New York Heart Association class was I in 240 cases (82%), II in 49 (16%), and III in 7 (2%). There were no late deaths or reoperations. CONCLUSIONS: Transatrial total correction of TOF can be accomplished in selected patients with good early results. In 300 cases (90%), the feasibility of transatrial total correction could be predicted accurately.
OBJECTIVE: Pulmonary artery banding is associated with a high morbidity and mortality. We describe a new technique of adjustable pulmonary artery banding to prevent these problems. METHODS: Between December 2003 and May 2005, 32 patients aged 18 days to 2 years (mean age, 2.5 +/- 0.5 months) and weighing 2.1 to 6.3 kg (mean, 3.6 +/- 1.3 kg) underwent adjustable pulmonary artery banding. RESULTS: All patients survived the operation. There were 2 deaths, one caused by meningitis and another caused by aspiration pneumonitis. Satisfactory band gradients were achieved between 3 and 10 days (7.2 +/- 2.6 days) in 3 to 6 sittings. Mean follow-up was 7.5 +/- 3.8 months (1-16 months). One patient required reoperation for unsatisfactory band gradient 2 weeks after discharge. There were no late deaths. Follow-up computed tomographic angiograms (n = 4) demonstrated proper band placement and ruled out distortion of the pulmonary arteries. Four patients underwent uneventful definitive operations after an interval of 7 to 13 months. CONCLUSION: This technique of percutaneously adjustable pulmonary artery banding is simple and inexpensive and allows easy band adjustments without the need for multiple reoperations.
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OBJECTIVES: The purposes of this study were to evaluate the myocardial histopathology and ultrastructure in patients with tetralogy of Fallot and to identify the histopathologic characteristics that may predispose patients to postoperative myocardial dysfunction and arrhythmias. PATIENTS AND METHODS: Operatively resected crista supraventricularis muscle from 183 patients undergoing intracardiac repair of tetralogy of Fallot aged 12 months to 42 years (mean, 106.84 +/- 79.35 months) were studied by light and electron microscopy. Biventricular function and cardiac rhythm were assessed by 2-dimensional echocardiography and electrocardiography. RESULTS: The incidence of moderate or severe cellular hypertrophy, endocardial thickening, and interstitial fibrosis was 36%, 68.3%, and 65%, respectively. Logistic regression analysis demonstrated age greater than 4 years, systemic arterial desaturation, higher hematocrit values, and elevated ventricular end-diastolic pressures as the major predisposing risk factors for pathologic changes. Twenty-seven (81.8%) patients more than 15 years of age and 29 (29.3%) patients between 4 and 15 years of age had predominant right ventricular dysfunction and low cardiac output (chi(2) [1 degree of freedom (df)] = 27.95; P < .001; odds ratio [OR] = 10.86 [3.75-33.10]). Ventricular arrhythmia was detected in 11 patients in whom repair was performed between 4 and 15 years of age and in 13 patients whose age at operation was 15 years or older. According to an additive logistic model, the effect of age at repair on the influence of ventricular arrhythmia was significant (chi(2) [1 df] = 24.4; P < .001; OR = 8.21 (2.96-23.11]). CONCLUSIONS: The great majority of myocardial tissues in cyanotic tetralogy of Fallot indicates pre-existing ultrastructural hypertrophic and degenerative changes. The changes are more pronounced in older patients subjected to long-standing cyanosis and pressure overload and may account for or may coexist with the higher incidence of myocardial dysfunction and ventricular arrhythmia.
BACKGROUND: We describe alternative surgical techniques for construction of systemic-to-pulmonary arterial shunts, and propose criterions for their application in selected patients. PATIENTS AND METHODS: We constructed a variety of modified systemic-to-pulmonary arterial shunts, using polytetrafluoroethylene grafts, in 92 selected patients with cyanotic congenital heart disease and anomalies of the aortic arch and systemic veins. Their age ranged from 7 days to 3.6 years, with a mean of 7.08 months. We performed 88 operations through a thoracotomy. Of this cohort, 60 patients underwent a second-stage operation, with 15 receiving a superior cavopulmonary connection, 16 a total cavopulmonary connection, and 29 proceeding to biventricular repair after a mean interval of 15.6 months. We have 21 patients awaiting their second or final stage of palliation. RESULTS: There were five early (5.4%) and six late deaths (6.8%), two of which were related to construction of the shunts. At a mean follow-up of 45.29 months, the increase in diameter of pulmonary trunk and its right and left branches was uniform and significant (p value less than 0.001). Pulmonary arterial distortion requiring correction at the time of second-stage operation was observed in 5 patients (6.1%). Adequate overall palliation was achieved in 98% of the cohort at 8 months, 91% at 12 months, and 58% at 18 months. CONCLUSIONS: Patients with a right- or left-sided aortic arch and right-sided descending thoracic aorta, those with anomalies of systemic venous drainage masking the origin of great arterial branches, and those with disproportionately small subclavian arteries, constitute the ideal candidates for our suggested modification of the construction of a modified Blalock-Taussig shunt. The palliation provided by these shunts was satisfactory, with predictable growth of pulmonary arteries, insignificant distortion in the great majority, and easy take-down.
We report two cases of mitral stenosis after Duran ring annuloplasty for myxomatous mitral regurgitation. Simple explantation of the ring provided relief of mitral stenosis.
Five patients of right pulmonary artery-to-left atrium communication presented with special emphasis on the clinical presentation, anatomic variations, diagnostic considerations, and management options. An individualized management algorithm is recommended.
This is a collective review of 59 published cases of right pulmonary artery to left atrium communication in the English-language literature. In this article, we review the literature on the clinical presentation, anatomic variations, diagnostic features, and management considerations of previously reported cases. Two-dimensional echocardiography and cardiac catheterization including selective angiography provided the necessary diagnostic information and defined the anatomy before surgery in all patients. Various management options including medical, surgical, and transcatheter closure have been reported. The lesions have been classified into four types (I, II, III, and IV) that have a bearing on the appropriate surgical approach and techniques of repair that are discussed in the text. Use of extracorporeal circulation may be considered in selected instances. The operative mortality rate during the earlier era (1950 to 1979) was high, at 22%. More recently, the mortality rate has approached zero. An individualized surgical approach depending on the type of surgical connections is recommended.
BACKGROUND: The aim of this study is to investigate the feasibility of chordal-sparing mitral valve replacement procedures in a rheumatic population, and to determine the early and late effects of different chordal preservation procedures on the clinical outcome and left ventricular mechanics. METHODS: Various techniques of chordal preservation during mitral valve replacement for rheumatic heart disease in 451 patients between 1996 and 1999 are described. The mean age was 35.6 +/- 19.0 years (range, 15 to 55 years). Seventy patients had complete excision of the subvalvular apparatus (group I), 124 had preservation of the posterior chordopapillary apparatus (group II), and 257 had total chordal preservation (group III). Echocardiography was performed preoperatively, at discharge, at 1 year, and at 4 years. RESULTS: Chordal preservation groups (II and III) demonstrated significant improvement (p < 0.05) in left ventricular function immediately and late postoperatively. Reduction of left ventricular end-systolic and end-diastolic volume was significant in the chordal preservation groups (II and III) as compared to the nonchordal group (group I; p < 0.005). The total chordal group demonstrated greater fractional change of left ventricular end-systolic volume as compared to the posterior chordal and nonchordal group. The left ventricular ejection fraction and fractional shortening continued to decline over time in the nonchordal cohort (p = 0.05 and p = 0.001, respectively) and did not improve by 4 years. Statistically significant change in ejection fraction occurred in the chordal preservation groups as compared to the nonchordal group. CONCLUSIONS: We conclude that total chordal preservation is possible in the large majority of rheumatic patients and confers significant long-term advantage by preserving left ventricular function. The surgical technique should be individualized.
BACKGROUND: The purpose of this study was to define the prevalence of specific sequelae after extracardiac Fontan operation. METHODS: Sixty-five consecutive patients undergoing extracardiac Fontan operation were studied for mortality, Fontan failure, systemic ventricular function, supraventricular arrhythmias, thromboembolism, and growth potential. Age was 3 to 31 years (mean +/- standard deviation, 9.4 +/- 1.8; median, 7 years). The conduits were constructed of polytetrafluoroethylene (n = 50), and "viable" in situ pericardium (n = 15). The patients underwent serial echocardiogram, dynamic radionuclide studies, and cardiac catheterization. RESULTS: Operative mortality was 3%, and the incidence of conduit thrombosis was 4.6%. There was paradoxic filling of the right lung after femoral injection of the radiotracer in all cases of conduit obstruction. Perioperative and late postoperative supraventricular arrhythmias were observed in 9.2% and 4.7% of patients, respectively. Risk factors for supraventricular arrhythmias included systemic ventricular dysfunction (p = 0.000), heterotaxy syndrome (p = 0.008), systemic venous anomalies (p = 0.015), and previous bidirectional Glenn operation (p = 0.017). At a mean follow-up of 77 +/- 2 months (range, 8 to 79 months), there were no late deaths (actuarial survival at 79 months, 96.9% +/- 0.02%). Serial echocardiograms demonstrated evidence of growth of the viable tunnels. Postoperatively, there was transient depression of ejection fraction in all patients (p = 0.000). CONCLUSIONS: Supraventricular arrhythmias after extracardiac Fontan are more common in patients with heterotaxy syndrome, bilateral superior venae cavae, systemic ventricular dysfunction, and those undergoing completion Fontan operation. The viable tunnel may emerge as an optimal alternative by virtue of reduction of supraventricular arrhythmias, elimination of the need for anticoagulation, and addressing the issue of growth potential in selected patients.
BACKGROUND: The study was designed to assess the long-term results of one and one-half ventricular repair on systemic and pulmonary circulation, right ventricular growth and function, and the prevalence of arrhythmias. METHODS: Eighty-four patients undergoing one and one-half ventricular repair between January 1990 and December 2003 were studied. Age was 4 to 504 months (mean, 47.9 +/- 57.3 months). Sixty-nine survivors underwent serial echocardiography, radionuclide studies, cardiac magnetic resonance imaging, and cardiac catheterization. RESULTS: Operative and late mortality were 10.7% and 8%, respectively. Perioperative and postoperative supraventricular arrhythmias were observed in 14.3% and 15.9% of patients, respectively. Risk factors for supraventricular arrhythmias included systemic ventricular dysfunction, heterotaxy syndrome, and Ebstein's anomaly. Mean late postoperative superior vena caval pressure was 14.2 +/- 1.52 mm Hg and right atrial pressure was 6.6 +/- 0.74 mm Hg. At a median follow-up of 87 months, actuarial survival was 81.9% +/- 0.04%, and 89.8% were in New York Heart Association class I or II. Serial cine-magnetic resonance imaging demonstrated significant growth of tricuspid valve and right ventricular cavity in 45% of patients. CONCLUSIONS: One and one-half ventricular repair can be performed with an acceptable risk. The operation maintains a low pressure in the inferior vena caval tributaries, and reverses the Fontan paradox. Patients with tripartite right ventricles demonstrated a tendency toward enlargement of the pulmonary ventricular chamber commensurable with somatic growth.