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Biomedical subjects

C Mavroudis

Publications and source records attributed to C Mavroudis.

At least 73 records · Page 4Linked to original sources
PubMed1997

The two-patch technique for complete atrioventricular canal.

The goals for repairing complete atrioventricular canal (atrioventricular septal defect) are ventricular septation, atrial septation, mitral valve reconstruction, and tricuspid valve reconstruction. Complications to avoid are heart block, residual septal defects, and dysfunctional atrioventricular valves. The surgical repair of atrioventricular canal has undergone major advances over the past 40 years. Excellent short- and long-term results have been achieved with both the single-patch technique and the two-patch technique. The single-patch technique is accomplished by dividing the common valve leaflets into their respective tricuspid and mitral components, suspending them from a single patch used to close the atrial and ventricular septal defects. The two-patch technique uses a prosthetic patch for the ventricular septal defect, a pericardial patch for the atrial septal defect, and suture closure of the anterior mitral cleft. Other variables include the use of deep hypothermia and circulatory arrest, mitral cleft closure, interrupted versus continuous suturing technique, and age at operation. Perhaps more important than the applied method is that the operation be properly executed to ensure defect closure and competent valves. We review our experience in 120 patients using the two-patch technique with special reference to the technical aspects of the operation. The two-patch technique of repair with routine cleft closure as evaluated by intraoperative transesophageal echocardiography results in a low surgical mortality, a low incidence of permanent heart block, and competent atrioventricular valves.

Atrioventricular Node↗
PubMed1996

Double-horned or caplike right ventricle: diagnosis and operative treatment.

BACKGROUND: Three patients reported here and 4 from the literature serve as background for the state-of-art diagnostic and operative considerations for an unusual congenital cardiac malformation: double-horned or caplike right ventricle. METHODS: This is a retrospective analysis of cardiac catheterization, cineangiography, and two-dimensional echocardiography findings, as well as palliative and corrective operations in 3 previously unreported patients. Four patients from the literature are reviewed. RESULTS: Characteristic morphologic features recognizable by invasive and noninvasive imaging distinguish double-horned right ventricle from complex malformations such as criss-cross hearts, superior-inferior ventricles, and univentricular hearts with a small outflow chamber. CONCLUSION: Double-horned or caplike right ventricle is a congenital malformation characterized by an unusual ventricular morphology, which may be the result of incomplete development of the right ventricle. The two-horned appearance may be secondary to an absence of the apical trabeculated compartment, with the left ventricle wedged between the two horns. It is invariably associated with double right ventricular outlet. Surgical experience so far suggest that most patients with typical double-horned right ventricle should be considered for anatomic surgical correction.

Cardiac Catheterization↗
PubMed1996

Taussig-Bing anomaly: arterial switch versus Kawashima intraventricular repair.

BACKGROUND: Current corrective surgical approaches for the Taussig-Bing heart include arterial switch with ventricular septal defect (VSD) closure and intraventricular repair as described by Kawashima. METHODS: Between 1983 and 1994, 20 children underwent intracardiac repair of Taussig-Bing anomaly. Mean age at operation was 17 months (range, 1 week to 9 years). Prior palliation included pulmonary artery band (15) with coarctation repair (8) and atrial septectomy (1). Arterial switch with VSD closure was performed in 16 patients, 10 with anteroposterior great arteries. Kawashima repair was performed in 4 patients, all with side-by-side great arteries. RESULTS: After arterial switch, there was one operative death (6.2%) due to myocardial ischemia and three late deaths (18.7%) due to pulmonary hypertension, gastrointestinal bleeding, and acute lymphocytic leukemia. In the Kawashima repair group there have been no deaths. After arterial switch, 9 patients underwent 11 reoperations for residual coarctation (3), residual pulmonary artery stenosis (2), aortic valve replacement, aortic valvuloplasty, unrecognized VSD, mitral valvuloplasty, mediastinitis, and pacemaker insertion. After Kawashima repair, 1 patient underwent reoperation for baffle stenosis and 1 for an unrecognized VSD. CONCLUSIONS: For children with Taussig-Bing anomaly, the Kawashima intraventricular repair (for side-by-side great arteries) preserves the native aortic valve and avoids coronary dissection. The arterial switch operation with VSD closure can be applied without ventriculotomy to all great artery relationships and allows neonatal repair with or without concomitant coarctation repair. Both techniques yield excellent early and intermediate-term results despite the high rates of prerepair palliation and postrepair reoperation for both groups.

Aortic Coarctation↗
PubMed1996

Expanding indications for pediatric coronary artery bypass.

Pediatric coronary artery bypass has been done mostly for ischemic complications of Kawasaki disease. We reviewed our clinical experience between 1987 and 1994 with internal thoracic artery-coronary artery bypass in one infant and five children for varying indications. Indications for coronary bypass included Kawasaki disease (2), congenital left main coronary ostial stenosis, iatrogenic coronary cameral fistula, anomalous origin of the left coronary artery from the pulmonary artery, and single coronary artery traversing between the great arteries in a patient after cardiac transplantation. An additional cohort of 34 control patients of various ages and weights (1 day to 16.1 years, 2.6 kg to 62 kg) had angiographic measurements of the right coronary, left coronary, and left internal thoracic arteries with respect to the feasibility of performing coronary artery bypass. All six patients survived internal thoracic artery-left anterior descending coronary artery bypass without evidence of perioperative myocardial infarction. Postoperative angiographic studies in five and color Doppler echocardiography in one showed graft patency. Retrospective angiographic measurements in the 34 control patients showed that internal thoracic and coronary arteries are proportionately quite large in neonates and infants compared with those in older children and adolescents. Internal thoracic artery-coronary artery bypass should be considered for the expanding indications presented herein and when emergency intraoperative life-threatening situations present themselves. Long-term patency and reoperation rates have yet to be determined.

Case-Control Studies↗
PubMed1996

Diltiazem preserves direct vasodilator response but fails to suppress intimal proliferation in rat allograft coronary artery disease.

BACKGROUND: We investigated the effect of diltiazem on transplant coronary artery disease in rat cardiac allografts both with standard histologic techniques and by measuring coronary vascular resistance and vasodilator response of the coronary arteries. METHODS: Hearts from Lewis rats were transplanted into Fischer 344 rats in an abdominal position without immunosuppression as a chronic rejection model. The rats were randomly divided into two groups: (1) no drug intervention (control; n = 36) and (2) diltiazem in drinking water (n = 33). Syngeneic transplants, Lewis donor to Lewis recipient, were used for isograft comparison (n = 17). Rat allografts were observed for length of survival, and at 4 months the surviving allografts were transferred to Langendorff perfusion, where coronary vascular resistance and its response to acetylcholine and nitroglycerin were examined. Allografts were also examined histologically and assigned transplant coronary artery disease and cellular rejection grades. RESULTS: Graft survival at 4 months was 43%, 38%, and 100% in control, diltiazem, and isograft groups, respectively. In the control group baseline coronary vascular resistance was much higher than in isografts (243 +/- 52 versus 35.3 +/- 6.2 cm H2O center dot gm center dot min/ml, p < 0.05) and the response to acetylcholine and nitroglycerin was significantly lower than that in the isografts (acetylcholine 6.2% +/- 4.8% versus 16.4% +/- 3.3%, p < 0.05; nitroglycerin 5.6% +/- 4.7% versus 12.6% +/- 5.7%, p < 0.05). In the diltiazem group baseline coronary vascular resistance (191 +/- 72 cm H2O center dot gm center dot min/ml) and the response to acetylcholine (7.3% +/- 2.9%) were similar to those in the control group (p = not significant); however, the response to nitroglycerin was better than that in the control group and in fact similar to that in the isograft group (13.6% +/- 7.0%; p < 0.05 versus control group, p = not significant versus isograft group). Histologic examination showed no coronary artery disease in isografts but equivalent marked transplant coronary artery disease and inflammation in both the control (transplant coronary artery disease grade 2.9 +/- 0.6, cellular rejection grade 3.6 +/- 0.7) and diltiazem (transplant coronary artery disease grade 3.0 +/- 0.8, cellular rejection grade 4.3 +/- 0.9) groups. CONCLUSION: In this transplant coronary artery disease model, diltiazem did not suppress the development of coronary intimal proliferation, but it did help preserve the vasodilative properties of the allograft coronary arteries in response to nitroglycerin, a direct vasodilator.

Animals↗
PubMed1995

Coarctation of the aorta. Repair with polytetrafluoroethylene patch aortoplasty.

BACKGROUND: The first successful surgical repair of coarctation of the aorta (CoAo) was performed in 1944, but during the years that followed a high incidence of recoarctation was seen, ranging from 20% to 86%. In response to that problem, the patch aortoplasty was introduced in 1957; however, true aneurysms were found in the aortic wall opposite the patch after Dacron patch aortoplasty, particularly when the coarctation ridge was excised. The purpose of our review was to evaluate the results of patch aortoplasty for CoAo using a relatively new material, polytetrafluoroethylene (PTFE), and an operative technique that does not involve resection of the coarctation ridge. METHODS AND RESULTS: Between 1979 and 1993, 125 infants and children underwent PTFE patch aortoplasty for CoAo; 111 of the procedures were primary repairs, and 14 were reoperations. Diagnoses were isolated CoAo (96 patients), CoAo and ventricular septal defect (15 patients), and CoAo with complex intracardiac anomaly (14 patients). Patient age at the time of repair ranged from 4 days to 17 years (mean age, 5.1 +/- 4.5 years). There were no instances of intraoperative mortality or paraplegia. There were 4 deaths from 10 to 40 days postoperatively, all in neonates (mean age, 33 days) who received additional intracardiac procedures for complex associated anomalies. Follow-up has ranged from 6 months to 12.5 years (mean, 4.5 +/- 3.2 years). All children had postoperative chest roentgenograms, 80 (66%) patients have had a postoperative echocardiogram and 16 (13%) a cardiac catheterization. One patient had successful repair of a false aneurysm 4 months postoperatively. No patient has developed a late true aneurysm. Of the patients < 1 month of age at the time of CoAo repair (12 patients), 6 patients had recurrent CoAo (gradient > 20 mm Hg) compared with only 4 recurrences in 97 patients > 1 month of age at the time of repair (P < .001). CONCLUSIONS: For children > 1 year of age, PTFE patch aortoplasty remains our procedure of choice for CoAo repair because of the low mortality rate, low recoarctation rate, and absence of late true aneurysms. We have stopped using this technique for infants < 1 month of age because of the high recurrence rate.

Adolescent↗
PubMed1995

Coarctation of the abdominal aorta.

Four patients with suprarenal coarctation of the abdominal aorta were managed from 1978 to 1993 (mean follow-up 8.75 years). Ages at the time of diagnosis were 2 months, 8 months, 4.5 years, and 15 years, respectively. Three children presented with severe hypertension, two of whom were in congestive heart failure, and the fourth child presented with a cold, ischemic leg. The 8-month-old patient had Williams syndrome (supravalvular aortic and pulmonic stenosis, bilateral renal artery stenosis and celiac artery occlusion, "elfin" facies, and mental retardation) and was treated nonoperatively. After 12 years of follow-up, he was given five medications to control hypertension, cardiac arrhythmias, and heart failure. Three patients with abdominal aortic coarctation were treated operatively and none died. Two patients underwent bypass grafting from the supraceliac aorta to the infrarenal aorta, with bilateral renal artery reconstruction in one. Postoperative arteriograms obtained 1 year or more after operation were normal in both cases. The 2-month-old patient underwent patch aortoplasty, with subsequent reoperation 1.5 years later for recurrent hypertension and heart failure with a bypass graft to the left kidney and removal of an infarcted right kidney. In all three patients, operative repair of the suprarenal aortic coarctation has resulted in long-term control of blood pressure and cardiac and renal function.

Adolescent↗
PubMed1995

Tetralogy of Fallot with anomalous origin of the right coronary artery.

This report describes a child with tetralogy of Fallot and acquired pulmonary valve atresia in whom the pulmonary blood flow was provided solely by retrograde flow from an anomalous right coronary artery originating from the main pulmonary artery. Complete repair with preservation of the native pulmonary valve and implantation of the right coronary artery into the ascending aorta is described.

Child↗
PubMed1995

Repair of complete atrioventricular canal defects: results with the two-patch technique.

BACKGROUND: Between 1983 and 1994, 115 infants and children underwent repair of a complete atrioventricular canal defect with the two-patch technique and routine mitral valve "cleft" closure. METHODS: A retrospective review of these 115 patients was performed. Age at the time of repair ranged from 1 month to 108 months (mean age, 14.2 +/- 16.5 months; median age, 8 months). Preoperative cardiac catheterization in 113 patients revealed a mean pulmonary to systemic flow ratio of 3.37 +/- 1.8, a mean pulmonary artery systolic pressure of 71.1 +/- 15.7 mm Hg, and a mean pulmonary vascular resistance of 4.9 +/- 3.3 units. Associated anomalies included Down's syndrome (99 patients), patent ductus arteriosus (47), and coarctation of the aorta (4). Rastelli classification was A (76 patients), B (10), C (24), and unknown (5). Twenty-four patients had intraoperative epicardial or transesophageal echocardiography. RESULTS: Although there was a trend toward increasing mean preoperative pulmonary vascular resistance with age from 2.1 +/- 0.9 units (0 to 3 months) to 4.0 +/- 2.6 units (4 to 6 months) to 5.7 +/- 3.0 units (7 to 12 months), the mean pulmonary vascular resistance of each age group was not significantly different from that of the main group. The operative survival rate was 94% (seven early deaths) and the overall survival rate, 91% (three late deaths). Intraoperative echocardiography altered the surgical therapy for 1 patient. No patient has required reoperation for a residual ventricular septal defect. Four patients (3.5%) had heart block requiring permanent pacemakers. Eight patients (7%) required reoperation for mitral insufficiency; 6 of whom had successful repair of a residual cleft. CONCLUSIONS: For infants with complete atrioventricular canal defect, repair using the two-patch technique with routine mitral valve cleft closure at 4 to 6 months of age results in a low operative mortality, a low incidence of permanent heart block, and a low reoperation rate for mitral insufficiency.

Age Factors↗
PubMed1995

Inhaled nitric oxide for children with congenital heart disease and pulmonary hypertension.

BACKGROUND: Endothelium-derived nitric oxide (NO) is a potent vasodilator and a major mediator of pulmonary vascular tone. METHODS: Five infants underwent a trial of inhaled NO with hemodynamic monitoring in the operating room after atrioventricular canal repair. An additional 15 patients with congenital heart disease and refractory pulmonary hypertension were treated with inhaled NO for 1 day to 10 days postoperatively. RESULTS: In the 5 infants with atrioventricular canal, corrective surgical intervention and conventional therapy (hyperventilation, inspired oxygen fraction of 0.80, and inotropic agents) lowered mean pulmonary artery pressure from 49.5 +/- 10.5 to 20.0 +/- 2.2 mm Hg (p < 0.001). Adding inhaled NO further decreased mean pulmonary artery pressure to 18.0 +/- 2.8 mm Hg (p = not significant). Inhaled NO had no effect on ventricular function curves (inflow occlusion) in this group. In the 15 patients with refractory postoperative pulmonary hypertension, 11 had a favorable response to inhaled NO, with a decrease in mean pulmonary artery pressure from 30.9 +/- 5.8 to 23.1 +/- 5.4 mm Hg (p < 0.01) in 8 patients with pulmonary artery catheters. CONCLUSIONS: These studies demonstrate that inhaled NO has minimal beneficial effect on pulmonary artery pressure or cardiac output in infants after repair of atrioventricular canal. Inhaled NO is effective in decreasing PAP postoperatively in select patients with congenital heart disease and pulmonary hypertension refractory to conventional therapeutic modalities.

Administration, Inhalation↗
PubMed1994

Role of endomyocardial biopsy in rejection surveillance after heart transplantation in neonates and children.

OBJECTIVES: The aim of this study was to retrospectively evaluate the sensitivity of noninvasive surveillance (physical examination, echocardiography) of rejection in accurately predicting histologically documented rejection episodes. Additionally, the usefulness of routine scheduled biopsy and its safety in pediatric patients was explored. BACKGROUND: Endomyocardial biopsy has been utilized as the standard for rejection surveillance after heart transplantation in adults, but its role in documenting clinically suspected rejection and in routine surveillance of pediatric patients has not been agreed upon. METHODS: Heart transplantation was performed in 14 neonates and 21 children. The immunosuppressive regimen consisted of cyclosporine, azathioprine and prednisone. All patients underwent routine noninvasive rejection surveillance that included clinical examination and echocardiography. In the neonates, biopsy was performed quarterly beginning 6 months after transplantation, after cessation of prednisone therapy. In the children, biopsy was performed 15 times in the 1st year. A minimum of five biopsy samples were interpreted using the Working Formulation for Heart Transplant Rejection. RESULTS: In the neonates, 37 biopsies were performed. Evidence of rejection was present in only three biopsy samples obtained during eight episodes (38%) of clinically suspected rejection. In 29 biopsies performed when rejection was not clinically suspected, each biopsy was free of cellular infiltrate. In the children, 291 biopsies were performed. Evidence of rejection was present in only seven biopsies (41%) from 17 episodes of clinically suspected rejection. Cellular rejection was discovered during routine rejection surveillance biopsies in asymptomatic patients in 23 (8.4%) of 274 biopsies. CONCLUSIONS: In neonates with clinically suspected rejection, endomyocardial biopsy identified which patients did not require rejection therapy. Endomyocardial biopsy surveillance did not detect any unsuspected cases of rejection. In children, noninvasive rejection surveillance was less reliable even in asymptomatic patients, suggesting that periodic endomyocardial biopsy should be utilized.

Biopsy↗
PubMed1994

Vascularized muscle flaps for life-threatening mediastinal wounds in children.

Vascularized muscle flaps have been shown to be highly effective in adults for complicated mediastinal and thoracic wounds. They result in infection control, wound coverage, and preservation of life. Minimal experience exists with the use of these techniques in children. We review our experience with vascularized muscle flaps between 1985 and 1993 in treating life-threatening mediastinal wounds in 8 children. The 8 patients ranged in age from 1 day to 10 years; mean age was 2 years. Two patients had mediastinitis; one had an exposed Gore-Tex graft, and the other had an exposed homograft conduit. One patient had a midline defect with exposed right ventricle immediately beneath the skin. One patient had tracheal dehiscence after repair of an acquired tracheoesophageal fistula from battery erosion. One patient with Marfan's syndrome had a pectus deformity and an unstable sternum after emergent reoperation for a false aortic aneurysm. Two neonates had their sternum left open with a temporary Silastic skin patch after orthotopic cardiac transplantation because of swelling of the donor heart. One transplant patient had wound dehiscence. Vascularized muscle flaps used to heal the mediastinal wounds in this group included pectoralis major (10), rectus abdominis (3), and cervical strap (1). One infant with asplenia and an exposed Gore-Tex graft that had a delayed vascularized muscle flap died of Candida sepsis. Seven of 8 patients (85%) healed their mediastinal wound. Prompt recognition of thoracic wound complications facilitates immediate surgical intervention to obtain primary closure with vascularized muscle flaps, which promotes rapid healing in these children.

Child↗
PubMed1994

Forty-six years of patient ductus arteriosus division at Children's Memorial Hospital of Chicago. Standards for comparison.

OBJECTIVE: The authors reviewed a large surgical experience (during five decades) with ligation and division of patent ductus arteriosus (PDA) in light of previously reported historical standards and present-day alternatives. SUMMARY BACKGROUND DATA: Ligation of PDA was first performed by Gross in 1938. Various surgical techniques used since then have included ligation and division, simple ligation, and hemaclip application. Recently introduced therapies include percutaneous transcatheter ductal closure devices (PTDC) and video-assisted thoracotomy (VAT). Percutaneous transcatheter ductal closure device protagonists cite surgical recurrence rates as high as 22% to justify continued application. METHODS: Between 1947 and 1993, 98.2% of 1108 patients (premature babies excluded) had interruption of PDA by ligation and division. Recent improvements have included muscle-sparing thoracotomy, minimal use of tube thoracostomy, and same-day surgery. RESULTS: Mortality was zero and morbidity (4.4%) has been low over time. Mean age at surgery has decreased from 5.9 +/- 3.3 years to 3.6 +/- 3.8 years (p < 0.001); patients requiring blood transfusion decreased from 34% to 4.6% (p < 0.001); and length of hospital stay (LOS) has decreased from 12.1 +/- 2.9 days to 3.8 +/- 2.1 days (p < 0.001). Length of stay for the last 27 patients was 2.8 +/- .8 days. Patient ductus arteriosus recurrence rate is zero with this technique. CONCLUSIONS: Recurrence rates for PTDC are high with as yet unknown consequences of large catheter vascular access, endocarditis, or left pulmonary artery stenosis. Video-assisted thoracotomy for PDA interruption has the potential for uncontrolled exsanguinating hemorrhage. Open thoracotomy for PDA ligation and division can be performed safely and without recurrence through a muscle-sparing incision with short LOS. All other therapeutic interventions must be compared to these standards.

Cardiac Surgical Procedures↗
PubMed1994

Management of severe congenital tracheal stenosis.

We have managed 23 infants and children with severe tracheal stenosis due to congenital complete tracheal rings producing a long-segment stenosis of the trachea. Nineteen (83%) have survived this life-threatening cause of airway obstruction, 7 of whom also had pulmonary artery slings. Pericardial patch tracheoplasty facilitated by partial cardiopulmonary bypass is currently our preferred technique for surgical repair. Eighteen patients (78%) underwent operative intervention, 3 of whom (17%) have died since surgery. The mean follow-up is 4.5 years. Bronchoscopy is essential for preoperative diagnosis and accurate intraoperative incision of the trachea, and is critical for long-term postoperative airway management. The more distal lesions are associated with increased complications and a higher mortality rate.

Airway Obstruction↗