Biomedical subjects
Publications and source records attributed to Ali Dodge-Khatami.
This article describes a modified technique of side-to-side proximal connection of a conduit during heterotopic implantation in the right ventricular outflow tract. It results in a better geometry of the right ventricular outflow and avoids distortion of the valve annulus, especially when the newer generation of straight xenografts are used.
BACKGROUND: Cardiac volumetry by magnetic resonance imaging can guide the timing for reoperation in minimally symptomatic or asymptomatic patients with pulmonary insufficiency after corrected tetralogy of Fallot. Pro-brain natriuretic peptide (BNP) is a marker of ventricular dysfunction and wall stress, and levels may complement magnetic resonance imaging in cardiac assessment before and after pulmonary valve replacement. METHODS: Between May 2004 and October 2005, 23 consecutive patients with corrected tetralogy, severe pulmonary insufficiency, and right ventricular end-diastolic volume index greater than 150 mL/m2 underwent elective pulmonary valve replacement. Plasma proBNP levels and magnetic resonance imaging were obtained before and 6 months after pulmonary valve replacement. RESULTS: There was no surgical mortality or morbidity. Preoperative right ventricular end-diastolic volume index correlated with pulmonary insufficiency, and inversely so with left ventricular ejection fraction, reflecting interventricular interaction. Preoperatively (r = -0.47) and 6 months postoperatively (r = -0.54), log BNP was inversely correlated with right ventricular ejection fraction. Mean preoperative proBNP levels, right ventricular end-diastolic volume index, and pulmonary insufficiency significantly (p < 0.0001) diminished 6 months after pulmonary valve replacement (231 versus 114 ng/L, 184 versus 109 mL/m2, and 44% versus 2%, respectively). CONCLUSIONS: Plasma proBNP is elevated in patients with corrected tetralogy, severe pulmonary insufficiency, and right ventricular dilatation, and it significantly diminishes 6 months after pulmonary valve replacement, mirroring magnetic resonance imaging-documented better right ventricular ejection fraction and smaller right ventricular end-diastolic volume index. Pro-brain natriuretic peptide complements magnetic resonance imaging for cardiac assessment in patients requiring pulmonary valve insertion. Future validation of cutoff levels are required to establish proBNP as a useful diagnostic and follow-up tool in patients with chronic pulmonary insufficiency and failing right ventricles.
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OBJECTIVE: To report the midterm results of an alternative minimally invasive approach for closure of ventricular septal defects (VSD) through a muscle-sparing minithoracotomy at the right midaxillary line. MATERIAL AND METHODS: From September 2003 to December 2005, 22 patients (median age, 5 years; range, 1.5-12 years) underwent a right lateral axillary thoracotomy for closure of a perimembranous VSD. Special features of the approach included an incision between the anterior and posterior axillary fold, a muscle-sparing preparation over the fourth intercostal space, and the establishment of cardiopulmonary bypass with inguinal and superior vena cava cannulation. The ascending aorta was cross clamped and cardioplegic arrest was instituted. The VSDs were all approached through a right atriotomy and closed directly (17 patients) or with a patch (5 patients). Three patients underwent concomitant aortic valve repair. RESULTS: There was no mortality or significant surgical morbidity. Median cross-clamp and cardiopulmonary bypass times were 46 and 104 min, respectively. Follow-up was complete and ranged from 2 to 22 months (median, 20 months). All patients were in sinus rhythm. Echocardiography revealed no residual defects with competent aortic and tricuspid valves. The length of the incision ranged from 4 to 6 cm, was away from the mammary gland, and remained entirely covered by the adducted arm. All children recovered right shoulder function within days, and cosmetic results were very satisfying. One patient developed iliac artery stenosis following inguinal artery cannulation. CONCLUSION: Closure of perimembranous VSDs in older children can be safely performed through a right axillary thoracotomy without compromising the accuracy of the repair. The cosmetic results are excellent.
AIMS: Correct timing of pulmonary valve replacement (PVR) is crucial for preventing complications of pulmonary regurgitation and right ventricular (RV) dilatation after repair of tetralogy of Fallot. We sought to assess the remodelling of the RV after early PVR in children, using cardiovascular magnetic resonance (CMR). METHODS AND RESULTS: Twenty children with severe pulmonary regurgitation and RV dilatation and mean age 13.9 +/- 3 years underwent CMR evaluation 5.6 +/- 1.8 months before and 5.9 +/- 0.6 months after PVR. PVR was performed when the RV end-diastolic volume exceeded 150 mL/m(2), as measured by CMR. The time interval between primary repair and PVR was 12 +/- 3 years. Post-operative CMR demonstrated a significant reduction of the RV end-diastolic volume from 189.8 +/- 33.4 to 108.7 +/- 25.8 mL/m(2) (P < 0.0001), of the RV end-systolic volume from 102.4 +/- 27.3 to 58.2 +/- 16.3 mL/m(2) (P < 0.0001), and of the RV mass from 48.7 +/- 12.3 to 35.8 +/- 7.7 g/m(2) (P < 0.0001). The RV ejection fraction did not change significantly. CONCLUSION: Prompt RV remodelling, with reduction of RV volume and mass, is observed after performing PVR if the RV end-diastolic volume exceeds 150 mL/m(2). Early PVR may prevent the detrimental complications of severe pulmonary regurgitation.
Atrial arrhythmias complicate the clinical course of adult patients with an atrial septal defect. Atrial flutter is more prevalent in younger patients, and frequently regresses after surgical defect closure. Atrial fibrillation however, which results from a chronic underlying disease, rarely reverts to sinus rhythm after surgical repair. While younger patients with atrial flutter clearly benefit from defect closure alone, this is not evident in older patients with fibrillation, who may need an additional anti-arrhythmic procedure concomitant to defect closure.
A 3-year-old boy underwent interventional closure of an atrial septal defect using an Amplatzer septal occluder. After 4 weeks, an aortic sinus-to-left atrial fistula was detected by echocardiography in an asymptomatic child. The device was surgically explanted with fistula and atrial septal defect closure. Follow-up was uneventful.
The Senning operation has evolved from being the initial surgical correction that allowed survival in complete transposition of the great arteries to an integral part of the anatomic repair of congenitally corrected transposition. In patients with complete transposition, the Senning operation has given satisfactory initial and long-term surgical results, but the potential for right ventricular failure and atrial arrhythmias have drastically reduced its indications in the current era. The long-term follow-up and pertinent postoperative issues of the Senning operation will be reviewed, along with its newfound role in the anatomic repair of congenitally corrected transposition.
BACKGROUND: This study is an assessment of early results of bovine jugular vein grafts (BJV) used to reconstruct the right ventricular outflow tract. METHODS: Ninety-three consecutive BJV implantations performed between May 2001 and August 2003 were included in this study. The median age was 7.2 years. Indications included various forms of tetralogy of Fallot and pulmonary atresia (56 patients), aortic valve disease requiring a Ross procedure (21 patients), truncus arteriosus (8 patients), d-transposition of the great arteries with ventricular septal defect and pulmonary stenosis (5 patients) and miscellaneous (3 patients). Additional plasty of the intrapericardial pulmonary arteries was performed in 41 patients. Follow-up was complete with a mean duration of 20.3 +/- 5.8 months. RESULTS: There were 3 patients (3.2%) with early deaths and 2(2.2%) with late deaths, but none were related to the bovine jugular vein grafts. Twelve bovine jugular vein grafts needed reintervention; 11 were due to development of a stenotic membrane at the anastomosis site and one was due to somatic outgrowth of the child (10 conduit replacements and two balloon dilatations). Overall freedom from reintervention was 91.6% and 83.5% at 12 and 24 months, respectively. Small size (< or = 14 mm) conduits show respective rates of 80.7% and 63.6%, whereas larger sizes were 98% and 96%, free from reintervention at 12 and 24 months. CONCLUSIONS: Bovine jugular vein grafts, when used for reconstruction of the right ventricular outflow tract, showed good early-term results. Attrition of small size bovine jugular vein grafts, due to development of a stenotic process at the anastomotic site needs to be closely observed. Longer follow-up is needed to allow a more definitive comparison with other established options.
BACKGROUND: The atriopulmonary Fontan circulation leads to arrhythmias, heart failure, or protein-losing enteropathy, eventually requiring conversion. In hesitant patients, we evaluated the effect of dual chamber pacing as a time-buying measure. METHODS: Between 1997 and 2004, 9 patients (aged, 6 to 18 years) with an atriopulmonary Fontan connection and sinus node dysfunction received dual chamber epicardial pacemaker systems. Indications included refractory arrhythmias (n = 5), protein-losing enteropathy (n = 2), heart failure with effusions (n = 1), and exercise intolerance (n = 2). Data were compared between hospital discharge after pacemaker implantation and last follow-up. RESULTS: There was no mortality or morbidity. At a follow-up of 3.3 +/- 1.0 years, lead survival was 100%. Both atrial (impedance = 683 +/- 40 Ohm; threshold = 0.8 +/- 0.1 V at 0.5 ms; sensing P waves = 3.3 +/- 0.8 mV) and ventricular (impedance = 630 +/- 68 Ohm; threshold = 1.3 +/- 0.3 V at 0.5 ms; sensing R waves = 8.7 +/- 2.5 mV) leads retained satisfactory pacing characteristics at last control, better than those at discharge. Arrhythmias subsided in all instances and no longer required medication in 3 patients. Protein-losing enteropathy improved temporarily in 1 patient and disappeared in another. Exercise intolerance diminished, and heart failure was controlled. CONCLUSIONS: Although most atriopulmonary Fontan circulations will need conversion with arrhythmia surgery, patients may delay out of fear. Dual chamber pacing improves single ventricle hemodynamics and can help decompensated Fontan patients. In a multiple-redo setting, a left lateral thoracotomy provides safe access and allows for quantitatively reliable and durable epicardial pacing.
BACKGROUND: In neonates and young infants (less than 3 months), coarctation may be missed or underestimated by echocardiography, especially with a patent ductus arteriosus or severe concurrent illness. A reliable noninvasive screening tool for coarctation would be useful for these patients. METHODS: From 1997 to 2003, echocardiographic evaluation was performed in 63 consecutive patients with coarctation (47 neonates and 16 infants) as well as in 23 controls (16 neonates and 7 infants). End-systolic measurements were obtained from 12 different sites of the aortic arch. RESULTS: In patients, the diameters of the ascending and descending aorta were comparable to controls, but the dimensions of the transverse arch were significantly smaller. The distances between the origins of the great vessels were longer in patients with coarctation than in controls. The ratio of the aortic arch diameter at the left subclavian artery, to the distance between the left carotid artery and the left subclavian artery, which we propose as the carotid-subclavian artery index, was significantly smaller in patients with coarctation. A cut-off point at 1.5 showed a sensitivity of 97.7% and 94.7%, and a specificity of 92.3% and 100%, for neonates and young infants, respectively. The positive predictive value to have coarctation was 97.7% and 100%, for neonates and infants, respectively. CONCLUSIONS: The carotid-subclavian artery index is a simply obtainable noninvasive screening parameter, showing high sensitivity and specificity for coarctation, and may be useful in unstable patients or in those with a patent ductus arteriosus in which coarctation may be overlooked.
BACKGROUND: This study assesses the results of early insertion of a pulmonary valve for chronic pulmonary regurgitation based on right ventricular volume measurements. METHODS: Valved conduits were prospectively inserted in 39 patients (aged 14 to 39 years) when the right ventricular (RV) end-diastolic volume index on magnetic resonance imaging (MRI) exceeded 150 mL/m2. Changes in morphology and function of the RV were prospectively analyzed by an MRI at 6 months postoperatively (available in 21 patients). RESULTS: There were no early or late deaths. All conduits showed good function at a median 15 month follow-up. Postoperative RV end-systolic and end-diastolic volumes showed a significant positive correlation (p = 0.005 and p < 0.0001), while postoperative left ventricular (LV) ejection fraction showed a significant negative correlation (p = 0.03) with preoperative RV end-diastolic volume index. Seven patients who achieved normal RV end-diastolic volume index (< or = 100 mL/m2) (group 1) when compared with 14 remaining patients (group 2) showed that they differed significantly with respect to their preoperative RV end-diastolic volume index (170.3 +/- 21.1 vs 203.6 +/- 35.6; p = 0.02) and postoperative LV ejection fraction (59.9 +/- 4.2 vs 54 +/- 7%, p = 0.03). CONCLUSIONS: Our results show that the improvement in ventricular dimensions and functions directly correlates with the timing of pulmonary valve insertion. Early insertion leads to normalization and late insertion leads only to improvement. These observations, along with a low morbidity for these reoperations, justify earlier reintervention in cases of chronic pulmonary regurgitation. A RV end-diastolic volume index of 150 mL/m2 seems to be a practical cutoff value to prescribe pulmonary valve insertion.
OBJECTIVE: Left heart atrial and ventricular epicardial pacing through a left lateral thoracotomy is an alternative approach for lead insertion in children, avoiding venous access complications and right ventricular stimulation, without compromising sporting or musical activities. We analyzed the survival and performance of left atrial and left ventricular epicardial pacing leads, and present mid-term follow-up data. METHODS: Seventy-five bipolar steroid eluting pacing leads (Medtronic CapSure Epi 4968) were implanted in 41 children, aged 8.6+5.1 years. Pacing systems included 34 DDDR and 7 VVIR. Pacing leads were inserted through a muscle-sparing left lateral thoracotomy, and sutured to the left atrial appendage or atrium, and to the left ventricle. The generators were buried behind the abdominal muscles or between the thoracic muscle layers. Congenital heart disease with previous cardiac surgery was present in 25 children. Indications for pacing were post-operative heart block (n=14), sinus node disease (n=13), congenital heart block (n=9), and various (n=5). Threshold values and measured data were obtained at 6-month intervals. The mean follow-up was 3.8+2.9 years. RESULTS: There was no mortality or major morbidity, with excellent functional and cosmetic results. Lead survival was 94 and 86% for atrial leads, and 97 and 86% for ventricular leads, at 1 and 5 years, respectively. There were five reoperations for lead fracture (n=2), insulation break (n=1), oversensing (n=1), and infection (n=1). Device reprogramming was required in three instances. In the absence of acute lead failure, mid-term follow-up shows very satisfactory and stable lead performance. CONCLUSIONS: Left heart atrial and ventricular epicardial pacing leads inserted through a left lateral thoracotomy demonstrate a high probability of survival, with favorable pacing characteristics, and optimal sensing thresholds at mid-term follow-up. Epicardial left heart pacing is reliable, and easy access can be achieved through a cosmetic and functional muscle-sparing left lateral thoracotomy.
OBJECTIVES: We sought to evaluate the safety of a right axillary incision, a cosmetically superior approach than anterolateral thoracotomy, to repair various congenital heart defects. METHODS: All the patients who were approached with this incision between March 2001 and October 2004 were included in the study. There were 80 patients (median age, 4 years) with atrial septal defect closure (38 patients), repair of partial abnormal pulmonary venous return (14 patients), partial atrioventricular canal (16 patients), and perimembranous ventricular septal defect (12 patients). The surgical technique involved peripheral and central cannulation for institution of cardiopulmonary bypass. Electrically induced ventricular fibrillation was used for defects located in front of the atrioventricular valves, and cardioplegic arrest was used for those located at the level or behind these valves. RESULTS: The repair was possible without need for conversion to another approach. One patient sustained a transient neurologic deficit. The patients were all in excellent condition after a mean follow-up of 14 months. The cardiac defect was repaired with no residual defect in 75 patients and with trivial residual defect in 5 patients (3 with mitral valve regurgitation, 1 with atrial septal defect, and 1 with ventricular septal defect). The incision healed properly in all, and the thorax showed no deformity. CONCLUSION: The right axillary incision provides a quality of repair for various congenital defects similar to that obtained by using standard surgical approaches. Because it lies more laterally and is hidden by the resting arm, it provides superior cosmetic results compared with conventional incisions, including the anterolateral thoracotomy. Finally, the incision is unlikely to interfere with subsequent development of the breast.
Patients with congenitally corrected transposition are at risk of right ventricular dysfunction and failure. With this in mind, we examined 13 patients with congenitally corrected transposition, 7 not having undergone surgery, and 6 after physiological repair, comparing them with 6 healthy subjects matched for age and sex, using cardiac magnetic resonance imaging, at rest and during dobutamine stress, in order to determine regional and global right ventricular response to stress. At rest, the patients had significantly decreased overall wall motion compared to their healthy peers (7.2 +/- 0.5, versus 9.8 +/- 0.4 mm). During infusion of dobutamine, overall wall motion increased to 12.8 +/- 0.4 mm in the healthy subjects, versus 8.8 +/- 1.0 mm in patients. At the regional level, significant differences in mural motion were found between patients and controls in the anterior (9.5 +/- 1.1, versus 13.2 +/- 0.6 mm), posterior (10.2 +/- 1.6, versus 13.2 +/- 0.8 mm), and septal segments (5.0 +/- 0.8, versus 11.2 +/- 0.6 mm). At rest, overall mural thickening in patients was similar to that of controls, but significantly less in patients during stress. During dobutamine stress, patients showed significantly less regional wall thickening than controls, particularly in the septal (2.7 +/- 0.6, versus 6.0 +/- 0.4 mm, respectively) and in the anterior segments (4.2 +/- 0.6, versus 7.8 +/- 0.6 mm, respectively). Right ventricular ejection fraction strongly correlated with mural motion and thickening, both at rest and during stress. Abnormal regional function in the systemic morphologically right ventricle may occur in patients with congenitally corrected transposition, which strongly correlates with right ventricular ejection fraction. Our findings support the hypothesis that, in patients with congenitally corrected transposition, ischemia of the right ventricular myocardium contributes to the development of right ventricular dysfunction.
BACKGROUND: Surgical closure of isolated ventricular septal defect (VSD) through partial inferior sternotomy offers the advantages of a much shorter, cosmetically superior skin incision, potentially improved sternal stability, a lower rate of infection, and less postoperative pain. We report our technique and results of use of inferior partial sternotomy for closure of isolated VSD in children. PATIENTS AND METHODS: From July 2002 to July 2003, 24 consecutive patients with a median age of 4.5 months (range, 1 month-4.5 years) underwent partial inferior sternotomy for isolated VSD closure. The length of the incision ranged from 4 to 6 cm. Special features of the approach included T incision of the lower sternum (from the fourth intercostal space to the xiphoid), establishment of cardiopulmonary bypass with central cannulation, aortic cross-clamping, and cardioplegic arrest. All VSDs were approached through right atriotomy. Perimembranous VSDs were exposed after detachment of the anterior leaflet of the tricuspid valve and were closed with a continuous suture. Muscular VSDs were approached directly. Perioperative and postoperative echocardiographic findings were available for all patients. Follow-up was complete. RESULTS: There was no mortality or significant surgical morbidity. Median cross-clamping and cardiopulmonary bypass times were 43 and 103 minutes, respectively. All patients were in sinus rhythm. Perioperative and postoperative echocardiography confirmed the absence of any residual defects in perimembranous VSDs and the presence of a trace residual VSD in 4 patients with muscular VSDs. Optimal healing of the partial sternotomy was obtained in all patients. CONCLUSIONS: Inferior partial sternotomy is less invasive than and cosmetically superior to full sternotomy. It provides excellent results when applied to isolated VSD with standard surgical techniques.
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BACKGROUND: We compared the long-term results of surgical valvotomy (S) versus balloon valvuloplasty (BV) for pulmonary valve stenosis in infants and children. METHODS: Results after surgical pulmonary valvotomy (with concomitant ASD/VSD closure) (n = 62, age 2.9 +/- 3.5 years) and balloon valvuloplasty (n = 108, age 3.6 +/- 3.9 years) were analyzed. Transvalvular mean pressure gradient decrease, freedom from reintervention for restenosis, pulmonary valve insufficiency, and tricuspid valve insufficiency were considered. RESULTS: Mean pressure gradient decreased significantly more in the surgical group (from 64.8 +/- 30.8 mm Hg to 12.8 +/- 9.8 mm Hg at a mean follow-up of 9.8 years) than after BV (decreasing from 66.2 +/- 21.4 mm Hg to 21.5 +/- 15.9 mm Hg after a mean of 5.4 years; p < 0.001). Moderate pulmonary valve insufficiency occurred in 44% after surgery, and in 11% after BV (p < 0.001). Tricuspid valve insufficiency occurred in 2% after surgery, and in 5% after BV. Restenosis occurred in 3 surgical patients (5.6%), 2 patients required reoperation, and 1 patient required a balloon valvotomy. Restenosis developed in 13 BV patients (14.1%): 6 patients were redilated and 7 patients required surgery. Surgical valvotomy led to significantly less reinterventions than balloon valvuloplasty (p < 0.04). CONCLUSIONS: Surgical relief of pulmonary valve stenosis produces lower long-term gradients and results in longer freedom from reintervention. Balloon valvuloplasty may remain, despite these results, the preferred therapy for isolated pulmonary valve stenosis, because it is less invasive, less expensive, and requires a shorter hospital stay. Surgery should remain the exclusive form of therapy in the presence of concomitant intracardiac defects, which need to be addressed.