Biomedical subjects
Publications and source records attributed to Balram Airan.
We present our experience with a patient in whom a homograft conduit was used to connect the superior vena cava (SVC) to the right pulmonary artery (RPA) in a functionally univentricular heart where corrective repair was impossible.
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.
Explore the source record for details and available documents.
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.
Explore the source record for details and available documents.
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.
OBJECTIVES: This study estimated the arterial-to-end-tidal carbon dioxide tension difference (deltaPaCO2-PE'CO2) in children with congenital heart disease; evaluated whether hyperventilation can reduce this difference; and analyzed the relationship between the difference and the oxygen saturation (SaO2) and hemoglobin level. DESIGN: Prospective clinical study. SETTING: Tertiary health care center. PARTICIPANTS: One hundred patients scheduled for correction of their underlying cardiac defect with either right-to-left or left-to-right intracardiac shunts were divided into 4 groups (n = 25 each): (1) N1, cyanotic with severe pulmonary artery hypertension; (2) N2, cyanotic with normal or decreased pulmonary artery pressure (PAP); (3) N3, acyanotic with normal or mild increases in PAP and severe increases in pulmonary blood flow (PBF); and (4) N4, acyanotic with normal PAP and normal or mild increase in PBF. INTERVENTIONS: All the patients received the same anesthetic regimen. The initial settings for tidal volume, respiratory rate, and inspiratory-to-expiratory (I:E) ratio were 10 mL/kg, 15 to 30 breath/min, and inspired time 40% of the total respiratory period with a 10% end-inspiratory pause. After the measurement of oxygen saturation, PO2, Hb, and deltaPaCO2-PE'CO2, all the children were hyperventilated (tidal volume: 14-15 mL/kg, respiratory rate: 5-6 breaths/min more than the initial rate, I:E ratio: same) to observe its effects on the deltaPaCO2-PE'CO2. MEASUREMENTS AND RESULTS: The deltaPaCO2-PE'CO2, when predicted from the oxygen saturation, hemoglobin concentration, and PaO2, was found to be greater than the observed value in the first 3 groups (p < 0.001); whereas in group N4 these 2 values were comparable. It was also found that the gradient was higher when there was a decrease in SaO2 and an increase in the hemoglobin level. After hyperventilation, in groups N1 and N3, deltaPaCO2-PE'CO2 was decreased when compared with their baseline values; this reduction was not as much as predicted (p = 0.363 and 0.236, respectively). However, in groups N2 and N4 posthyperventilation, the deltaPaCO2-PE'27 CO2 was decreased significantly below their baseline measurements. These decreases were as much predicted. CONCLUSION: The deltaPaCO2-end-tidal carbon dioxide (PE'CO2) can be increased both in cyanotic and acyanotic children. Increased PAP is as important as increased PBF or right-to-left shunting in producing disorders in carbon dioxide homeostasis. Hyperventilation is of little use in reducing deltaPaCO2-PE'CO2 in children with high PAPs and pulmonary hyperperfusion.
Explore the source record for details and available documents.
BACKGROUND AND OBJECTIVES: Stable sternal approximation is an important factor to avoid respiratory complications after open heart surgery. The present study is designed to compare interlocking sternotomy and straight sternotomy in terms of sternal stability, pain and respiratory function. METHODS: Sixty patients scheduled for open heart surgery underwent a standard midline sternotomy (n=30) or an interlocking sternotomy (n=30). The features assessed were pain on visual analogue scale during rest and during cough, peak expiratory flow rate and sternal instability. Evaluation was performed on the first, fourth post-operative days, on discharge and one month and three month follow up. RESULTS: Analysis of the peak expiratory flow rates, visual analogue ratings of pain intensity at rest and on coughing were carried out for each group only for those patients who completed the study. Postoperatively, in all patients there was significant reduction in peak expiratory flow rates. In the straight sternotomy group resting pain intensity was higher on discharge (2.6+/- 2 vs 1.6 +/- 2.3, P= 0.005). In the interlocking sternotomy group pain on coughing was significantly less than straight sternotomy group (median 0.5 vs 2.8, P=0.005) at 1 month follow up and at 3 months (median 0 vs 1.6, P=0.003). INTERPRETATION AND CONCLUSION: Interlocking sternotomy can be performed with good functional results and offers a less painful alternative to straight sternotomy.
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.
Explore the source record for details and available documents.
BACKGROUND: The purpose of this investigation was to determine the role of radionuclide studies in evaluating postoperative Fontan hemodynamics and to quantify its diagnostic accuracy. METHODS: One hundred five patients (105), aged 11 months to 35 years old, who had undergone univentricular repair, underwent first-pass and multigated acquisition scan 1 month to 10 years after univentricular repair. Forty-five patients with evidence of Fontan failure underwent radionuclide studies using Technetium-99 m as well as cardiac catheterization (group 1). The remaining sixty randomly selected patients with excellent functional status received radionuclide studies alone (group 2). The receiver operating characteristic curve analysis was done to quantify the diagnostic accuracy of the first-pass study. RESULTS: There was paradoxical filling of the right lung after femoral injection in all cases of tunnel or conduit obstruction. A first-pass transit time of 16 to 25 seconds (mean +/- standard deviation [SD] = 18.82 +/- 2.69) was always associated with Fontan failure and high right atrial pressure (range = 20 to 24 mm Hg, mean +/- SD = 22.02 +/- 1.58). A first-pass transit time of 16 seconds was associated with a sensitivity of 100% and a specificity of 93.33%. The predictive accuracy of a positive or negative result was 91.8% and 100% respectively. The area measured under the receiver operating characteristic curve indicates that 99.41% (SE +/- 0.0035) of the time, the value of first-pass time is higher for the Fontan failure group (group 1) compared to the normal group (group 2; p = 0.000). CONCLUSIONS: Our data indicate that Fontan circuit can be reliably evaluated for both anatomic and functional flaws by radionuclide studies; radionuclide first-pass time may be used to predict the chances of Fontan failure postoperatively as well as its presence; and in the presence of atrial fibrillation with fast ventricular rate, analysis using first-pass radionuclide may be impossible and gated equilibrium radionuclide angiocardiography may be the preferred method. Inspection of the systemic ventricular time-activity curve is of crucial importance in this regard.