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Biomedical subjects

Panangipalli Venugopal

Publications and source records attributed to Panangipalli Venugopal.

36 records · Page 2Linked to original sources
PubMed2005

Interruption of aortic arch in adults: surgical experience with extra-anatomic bypass.

We reviewed our 3-year experience in treating interruption of the aorta in adult patients. Clinical profiles, surgical management, and results of early and mid-term follow-up are presented. From August 2001 through June 2003, 7 adult patients underwent an extra-anatomic bypass procedure to repair interruption of the aortic arch. Five patients underwent ventral aortic repair through a mid-sternotomy and an upper midline laparotomy, and 2 patients underwent repair through a left posterolateral thoracotomy. A bovine collagen-impregnated polyester fiber graft was used in 6 patients, and a Gore-Tex graft was interposed in 1 patient. All repairs were performed without cardiopulmonary bypass. Follow-up was complete in all patients. The mean follow-up was 1728 +/- 1 months (range, 9-31 months). No neurologic, renal, or gastrointestinal complications were noted in any patient. There was no in-hospital or late mortality or need for re-intervention. All patients were asymptomatic; however, 5 patients had mild residual hypertension. Graft patency in all the patients was confirmed by computed tomographic angiography. Interruption of the aorta is rare in adults. Ventral aortic repair through a midline approach is our preferred technique for surgical repair of this entity, because it avoids the extensive network of collateral vessels on the chest wall, enables simultaneous treatment of associated lesions, and in all likelihood reduces morbidity and mortality.

Adult↗
PubMed2004

Postoperative assessment of the univentricular repair by dynamic radionuclide studies.

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.

Adolescent↗
PubMed2004

Histopathology and morphometry of radial artery conduits: basic study and clinical application.

BACKGROUND: The purpose of this study was to determine the pathohistology, morphometry, and risk factors for the development of intimal hyperplasia, calcification, and arteriosclerosis in the radial artery and to compare the morphometry of the distal and proximal radial arteries. METHODS: A total of 190 proximal and distal radial artery specimens obtained from patients who underwent myocardial revascularization were exposed to histopathologic and morphometric analysis. The severity of disease was evaluated on the basis of the percentage of luminal narrowing, intimal thickness index, and intima-to-media ratio. RESULTS: Sixty-two proximal (32.6%) and 22 distal (11.5%) radial artery segments were indicated as histologically normal. Morphometric analysis (Z test) revealed a lesser degree of intimal hyperplasia and luminal narrowing in the proximal segments compared with the distal segments (p < 0.001). The incidence of intimal hyperplasia, medial calcification, and arteriosclerosis in the distal radial arteries was 76.3%, 6.3%, and 5.78%, respectively. Using multivariate logistic regression, we have identified three significant predictors for intimal hyperplasia. Expressed as an odds ratio with a 95% confidence interval, these included (i) age greater than 50 years (1.052; 1.000-1.106, p = 0.052), (ii) smoking (14.073; 5.293-37.414, p = 0.000), and (iii) hypertension (2.777; 1.171-6.583, p = 0.020). Factors associated with an increased likelihood of medial calcification and arteriosclerosis included a history of smoking, diabetes, hypercholesterolemia, peripheral arterial disease, and chronic renal failure (p < 0.05). CONCLUSIONS: The great majority of radial artery conduits indicate preexisting intimal hyperplasia mostly affecting the distal portion. Therefore in cases of longer diseased segments of radial arteries, the discarded segments should be the distal end. Care should be taken when selecting radial artery as a conduit in myocardial revascularization, particularly in elderly males, diabetics, smokers, hypertensive patients, and in those with associated peripheral vascular disease.

Adult↗
PubMed2004

Dose comparison of tranexamic acid in pediatric cardiac surgery.

To compare different doses of tranexamic acid, 150 consecutive children with congenital cyanotic heart disease were randomly assigned to one of 5 groups of 30 each. Group A served as a control. Group B received 50 mg.kg(-1) of tranexamic acid at induction of anesthesia. Group C received 10 mg.kg(-1) at induction followed by an infusion of 1 mg.kg(-1).h(-1). Group D had 10 mg.kg(-1) at induction, 10 mg.kg(-1) on bypass, and 10 mg.kg(-1) after protamine. Group E had 20 mg.kg(-1) at induction and again after protamine. The control group had the longest sternal closure time, the greatest blood loss in the first 24 hours, and the highest requirements for blood and blood products. Among the 4 groups given tranexamic acid, group D (triple dose) had the best results, followed by group E (double dose). Group B (single dose) had the worst results among the groups receiving tranexamic acid.

Adolescent↗
PubMed2003

Modified circuit for retrograde cerebral perfusion.

A modified circuit for delivery of retrograde cerebral perfusion during ascending aortic or aortic arch surgery is described. The technique was applied in 15 patients who showed good postoperative recovery.

Aortic Dissection↗
PubMed2002

Simplified technique for retrograde cerebral perfusion during repair of distal aortic arch and proximal descending thoracic aorta.

Lesions of distal aortic arch and proximal descending thoracic aorta require a posterolateral thoracotomy approach and total circulatory arrest. Retrograde cerebral perfusion through the superior vena cava is technically difficult in such situations. We describe a simplified technique for delivery of retrograde cerebral perfusion through the left internal jugular vein.

Adult↗
PubMed2002

Left ventricle is better suited as pulmonary ventricle in simple transposition with severe pulmonary hypertension.

BACKGROUND: The conventional treatment of transposition of great arteries with prepared left ventricle is an arterial switch operation. This, in our experience, does not hold for patients with transposition of great arteries with intact ventricular septum where the left ventricle continues to be prepared secondary to severe pulmonary arterial hypertension without an immediately reversible cause. METHODS: Ten infants with D-transposition of the great arteries with essentially intact interventricular septum and severe pulmonary arterial hypertension underwent surgical treatment. Age ranged from 3 to 6 months (mean, 4.2 months). One of these patients had a large ductus with left to right shunting but the others had no intra- or extracardiac shunt to account for their pulmonary hypertension. All 10 had "prepared" left ventricles. The first 4 children underwent an arterial switch operation. Uneventful surgery was followed by prolonged ventilator dependence in all 4 with occurrence of severe pulmonary arterial hypertension every time weaning from ventilator was attempted. This was accompanied by metabolic acidosis and features of right heart failure. Only 1 patient with large ductus could be extubated and discharged from hospital. Subsequently, the other 6 infants underwent a Senning repair. RESULTS: There was no early mortality. All patients were separated from mechanical ventilation within 48 hours of surgery without blood gas derangement or heart failure despite elevated pulmonary artery pressure in all. The child with the arterial switch operation has pulmonary artery pressure of 50% systemic 4 years following repair; although among the Senning group, 2 patients continue to have pulmonary artery pressure more than 60% of systemic and 4 have normal pulmonary artery pressure at a mean follow-up of 1 year. CONCLUSIONS: Atrial level repairs seem to perform better than arterial level repairs in children having TGA with persistent pulmonary artery hypertension without a correctable cause. Better tolerance of pulmonary arterial hypertension in this group is probably consequent to the superior ability of the left ventricle to tolerate a pressure load in the early postoperative period.

Ductus Arteriosus, Patent↗
PubMed2002

Late outcome after arterial switch operation for complete transposition of great arteries with left ventricular outflow tract obstruction.

BACKGROUND: Long-term follow-up of patients who underwent arterial switch operation for complete transposition of great arteries with anatomic left ventricular outflow tract obstruction (LVOTO) has rarely been brought into the focus. METHODS: Of 299 patients who underwent an arterial switch operation between January 1991 and January 2001, 23 patients had anatomic LVOTO. Age ranged from 4 days to 18 years (median 90 days) and weight ranged from 2.6 to 35 kg (median 4.3 kg). Surgical management included arterial switch operation, closure of ventricular septal defect wherever indicated, and excision of LVOTO. RESULTS: Among patients with preoperative LVOTO there were 2 early deaths and 8 patients had mild neoaortic regurgitation at the time of discharge. Follow-up ranged from 8 months to 9 years (mean 60 +/- 12 months). In 4 patients who had mild neoaortic regurgitation at discharge, the regurgitation progressed to moderate or severe degree after a follow-up of 22 to 72 months. In 1 patient mild mitral regurgitation present at the time of discharge progressed to severe mitral regurgitation. This patient subsequently underwent double valve replacement. CONCLUSIONS: Presence of preoperative anatomical LVOTO in patients undergoing arterial switch operation predicts high incidence of postoperative neoaortic regurgitation.

Adolescent↗
PubMedDate not supplied

Hemangioma of the tricuspid valve: a report of two cases with review of literature.

We describe two cases of hemangioma affecting the tricuspid valve (TV). One patient was a 47-year-old male who presented with recurrent episodes of dyspnea on exertion for 5 years. Echocardiography revealed an echo dense 1 x 1 cm mass attached to the chordae tendineae of the TV. Surgical excision was done and histopathology of the lesion showed features of hemangioma. The other case was a 1-day-old neonate with complex congenital abnormalities in whom multiple small hemangiomas affecting the TV were incidentally detected at autopsy.

Dyspnea↗
PubMedDate not supplied

Redo mitral valve surgery-a long-term experience.

BACKGROUND: Our experience with reoperative mitral valve (MV) surgery over a 27-year period is presented here. METHODS: From January 1975 to June 2002, 11,908 operations were performed for MV disease. Out of these 744 were reoperations. The mean age at primary operation was 23.6 +/- 10.1 years (range 2 to 53 years) and at reoperation was 36.0 +/- 11.0 years (range 6 to 65 years) with a mean interval of 11.5 +/- 2.5 years. Mitral valve replacement (MVR) was performed following previous closed mitral valvotomy (CMV) in 408 patients, open mitral commissurotomy (OMC) in 21 patients, and MV repair in 58 patients, MVR in 80 patients, homograft mitral valve replacement (HMVR) in 11 patients. The reasons for reoperation were mainly progression of lesions. Valve thrombosis and endocarditis were indications for reoperation following MVR. Twenty-eight patients underwent redo CMV, 53 patients underwent OMC, and 14 patients underwent MV Repair. RESULTS: Early mortality was 5.64% (n = 42). Hemorrhage and low cardiac output were the major causes. Follow-up was 124.8 +/- 30.5 months (2 to 300 months). Follow-up was 88%. There were no late deaths in the valve repair group. There were three episodes of thromboembolism in this group (0.3% per patient-year). In the valve replacement group there were six late deaths; three due to valve thrombosis, one due to infective endocarditis, and two due to anticoagulant-related hemorrhage. There were 13 episodes of thromboembolism in this group (0.6% per patient-year). CONCLUSION: Redo MV surgery is safe and can be undertaken with acceptable mortality and morbidity.

Adolescent↗
PubMedDate not supplied

Ventricular septal defect with congenital mitral valve disease: long-term results of corrective surgery.

BACKGROUND: A retrospective analysis of the mortality, morbidity and long-term follow-up of patients undergoing corrective surgery for ventricular septal defect and congenital mitral valve disease is presented. METHODS AND RESULTS: Between January 1991 and December 2000, 69 consecutive patients aged 2 months to 45 years (median 18 months) underwent repair of ventricular septal defect and associated mitral valve disease. In 52 patients (75%), the ventricular septal defects were located in the perimembranous and subarterial area. Forty-six patients had congenital mitral incompetence and 23 had congenital mitral stenosis. The ventricular septal defect was repaired through the right atrium in all. Sixty-five patients underwent reconstruction of the mitral valve and 4 underwent primary mitral valve replacement. Another 4 patients underwent mitral valve replacement after a failed repair. Associated procedures included: patent ductus arteriosus ligation (n=12), aortic valve replacement (n=6), coarctation repair (n=13), interrupted aortic arch repair (n=1), atrial septal defect closure (n=17) and Takeuchi repair (n=1). There were 6 early deaths (8.6%). Three deaths were due to pulmonary arterial hypertensive crisis and one due to residual mitral stenosis. One death was due to intractable congestive heart failure. Another patient died due to persistent low cardiac output. Follow-up ranged from 6 months to 120 months (mean 64.4+/-33.6 months). Reoperation was required in 22 patients, mainly for recurrent/residual mitral valve dysfunction or hemodynamically significant left ventricular outflow tract obstruction. There were 4 late deaths, 2 due to residual mitral stenosis and the other 2 as a result of a thrombosed prosthetic valve. At 10 years, the actuarial survival rate was 850+/-5.0%, and freedom from reoperation was 45%+/-10.0%. CONCLUSIONS: Reconstruction of the mitral valve along with closure of VSD is possible in most cases. However, careful follow-up is recommended to detect changes in the mitral valve status over a course of time.

Adolescent↗
PubMedDate not supplied

Medium-term outcome of anatomically repaired congenitally corrected transposition: the double switch operation.

BACKGROUND: The double switch operation is emerging as the procedure of choice for congenitally corrected transposition of the great arteries. However, rhythm disturbances in the postoperative period are rarely discussed. METHODS AND RESULTS: Eighteen survivors who underwent corrective surgery for congenitally corrected transposition of the great arteries were followed up. Patients in group I (n=8), who also had a ventricular septal defect and pulmonary stenosis, had undergone the Senning plus Rastelli operation. Patients in group II (n=10), who did not have pulmonary stenosis, had undergone the Senning and arterial switch operation. The patients were followed up by periodical clinical examination, echocardiography and 24-hour Holter monitoring. In group I, follow-up ranged from 24 to 66 months (mean 44 months). There was no late death and all the patients are symptom free. There was no significant atrioventricular valve regurgitation and left ventricular function was normal. There were no rhythm disturbances. In group II, follow-up ranged from 2 to 72 months (mean 48 months). There were 2 late deaths due to atrial tachyarrhythmia and residual pulmonary hypertension 36 and 8 months after the procedure, respectively. One patient had significant mitral regurgitation and required mitral valve replacement. Three patients had recurrent atrial/junctional tachyarrhythmia: one of them was lost to follow-up after 1 year while another died of resistant atrial tachyarrhythmia. The third patient underwent mitral valve replacement for severe mitral regurgitation and developed complete heart block necessitating a permanent pacemaker implantation. CONCLUSIONS: Though good long-term results are obtained following the double switch operation, the problem of atrial arrhythmias still needs to be addressed suitably.

Adolescent↗
PubMedDate not supplied

Minimally invasive pulmonary artery banding: a new approach.

BACKGROUND: A variety of approaches have been described for banding of the pulmonary artery. The indications for this procedure are limited; however in developing countries, many patients still need pulmonary artery banding for a variety of reasons. We describe a new approach, minimally invasive, using only a split in the manubrium sterni to conduct the procedure. METHODS AND RESULTS: Between January 2000 and May 2002, 19 patients who had undergone pulmonary artery banding using a minimally invasive technique were compared with 20 cases of pulmonary artery banding performed by the conventional technique. The mortality was similar in the two groups (p=0.45). The period of intubation and duration of intensive care unit stay were significantly shorter in the minimally invasive group (p=0.015 and 0.002, respectively). The duration of hospital stay was not significantly different between the 2 groups (p=0.139). In the minimally invasive group, three patients underwent subsequent reoperation. CONCLUSIONS: Minimally invasive pulmonary artery banding is useful in babies with high-flow cardiac lesions and cardiac cachexia.

Case-Control Studies↗
PubMedDate not supplied

Surgical outcome of staged univentricular-type repairs for patients with univentricular physiology and pulmonary hypertension.

BACKGROUND: There is no consensus about the most appropriate limits of pulmonary artery pressure and vascular resistance in case of patients undergoing univentricular or one and one-half ventricular repair. This study was conducted to analyze the mortality and morbidity of a heterogenous group of patients with a functionally univentricular heart and pulmonary artery hypertension, undergoing pulmonary artery banding followed by univentricular-type repairs. METHODS AND RESULTS: Out of 254 patients undergoing pulmonary artery banding for a functionally univentricular heart with increased pulmonary blood flow, 148 patients underwent definitive second stage surgery. Post-band hemodynamic evaluation revealed persistently high pulmonary artery pressure (> 18 mmHg), and pulmonary vascular resistance (>2.0 Woods units/m2) in 78.3% patients. Sixteen patients with moderate right ventricular hypoplasia were given a one and one-half ventricle repair (Group I), 82 patients a bidirectional Glenn connection (Group II), and 50 patients a fenestrated total cavopulmonary connection (Group III). The overall mortality following second stage surgery for the high pulmonary artery pressure group (n=116) was 30.17%, while none of the low pulmonary artery pressure group died (p=0.0009). Pulmonary hypertensive crises and/or systemic desaturation were the main causes of death at second stage repair. All mortality occurred in patients with mean pulmonary artery pressure > 18 mmHg and pulmonary vascular resistance > 3.5 Woods units/m2. Survivors from this group had persistent morbidity in the form of superior vena caval syndrome and suboptimal oxygen saturation (70-75%). CONCLUSIONS: It is advisable not to proceed with definitive second stage repair if post-pulmonary artery banding mean pulmonary artery pressure is over 25 mmHg and pulmonary vascular resistance exceeds 4.0 Woods units/m2. These patients may possibly be deemed to have undergone definitive palliation during their pulmonary artery banding.

Cardiac Surgical Procedures↗
PubMedDate not supplied

Congestive heart failure in unoperated tetralogy of Fallot: can hypoxia be a cause?

A 10-year-old boy with tetralogy of Fallot and congestive heart failure underwent a right-sided modified Blalock-Taussig anastomosis because of severe biventricular dysfunction and repeated hypercyanotic spells. Postoperatively, there was improvement in systemic oxygen saturation and myocardial function. We postulate that congestive heart failure occurred because of severe myocardial hypoxia and its elimination resulted in markedly improved cardiac performance.

Blood Vessel Prosthesis Implantation↗