Farouk S. Idriss

Discrete subvalvular aortic stenosis in childhood: Study of 51 patients

Fifty-one children with discrete subvalvular aortic stenosis were studied between 1951 and 1974. The three anatomic types of obstruction found were the thin membranous type (43 cases), the fibromuscular collar type (5 cases) and the tunnel type (3 cases). The obstruction was usually severe, and the median left ventricular to aortic systolic pressure gradient was 90 mm Hg. Progressive obstruction with an increasing gradient was documented in 10 patients by serial cardiac catherizations. Significant associated cardiac defects, present in 57 percent of patients, often masked the typical clinical and cardiac catheterization features of subaortic stenosis. The stenosis was often not discovered until after surgery for the associated defect. Forty patients underwent surgical resection of the discrete subaortic obstruction. After surgery significant left ventricular to aortic pressure gradients can be found at postoperative cardiac catheterization. These gradients may reflect inadequate resection of the more complex discrete obstructions or represent proliferation and regrowth of the previously resected subvalvular fibrous tissue. The criteria for operability of discrete subaortic stenosis should be the angiographic demonstration of a discrete subvalvular diaphragm and the presence of a resting left ventricular to aortic systolic pressure gradient of 40 mm Hg or more.

Pulmonary vascular disease in complete transposition of the great arteries: A study of 200 patients☆

Abstract Lung specimens of 200 patients with transposition of the great arteries were examined microscopically for evidence of pulmonary vascular disease. In patients with an intact ventricular septum or a small ventricular septal defect, advanced pulmonary vascular disease was uncommon; only 9 of 107 such patients (8.4 percent) demonstrated greater than grade 2 (Heath-Edwards) pulmonary vascular disease. A persistent large patent ductus arteriosus appeared to promote progressive pulmonary vascular disease in this group since each of the five infants less than 1 year of age with grade 3 or 4 disease had this lesion. In contrast, pulmonary vascular disease was common in patients with a large ventricular septal defect; 37 of 93 patients (40 percent) with this defect had greater than grade 2 pulmonary vascular disease. Among patients more than 1 year of age, 26 of 35 (75 percent) had grade 4 disease. The catheterization data suggest that the calculated pulmonary vascular resistance may underestimate the degree of disease, probably by overestimating the pulmonary blood flow (Fick method). Pulmonic stenosis appeared to protect the lungs from progressive pulmonary vascular disease, and pulmonary arterial banding was protective when performed before age 6 months. Our studies indicate that a persistent large patent ductus arteriosus should be closed as early as possible in view of its association with advanced pulmonary vascular disease in these patients. In infants with a large ventricular septal defect, pulmonary arterial banding or corrective surgery with closure of the defect should be performed between the ages of 4 and 6 months to prevent progressive pulmonary vascular damage.

Choreoathetosis after deep hypothermia without circulatory arrest

In 8 of 758 patients undergoing an intracardiac operation under cardiopulmonary bypass and hypothermia, choreoathetosis developed 3 to 7 days postoperatively. Before the onset of choreoathetosis, varying degrees of neurological dysfunction were noted. Electroencephalography and neuroimaging failed to detect any responsible functional or structural changes. Six patients are alive 1 to 3 years postoperatively, and their condition is improving. Two patients died of aspiration or sepsis. All patients were grouped based on factors identified as being possibly causative: depth of hypothermia, cooling time, flow rate, and repeated hypothermia. The incidence of choreoathetosis was significantly different in group A (rectal temperature greater than 25 degrees C) compared with group B (rectal temperature less than or equal to 25 degrees C) (0/295 versus 8/463; p = 0.02). Based on cooling time, the incidence of choreoathetosis was significantly different in group B1 (cooling time less than 1 hour) compared with group B2 (cooling time greater than or equal to 1 hour) (1/220 versus 7/243; p = 0.05). Based on flow rate during cooling, group B2 was further divided into the low-flow group (less than 1,500 mL.min-1.m-2) and the high-flow group (greater than or equal to 1,500 mL.min-1.m-2). Although not significant, the incidence of choreoathetosis was higher in the high-flow group (6/153 versus 1/90; p = 0.22). In group B patients having reoperation, the incidence of choreoathetosis was higher than in patients operated on for the first time (5/54 versus 3/409; p less than or equal to 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Pericardial patch tracheoplasty for severe tracheal stenosis in children: Intermediate results

Between 1982 and 1990, 15 children have undergone pericardial patch tracheoplasty, 13 for complete tracheal rings and 2 for acquired tracheal stenosis. Eleven had complete tracheal rings from the thoracic inlet or the cricoid to the carina. Diagnosis was by bronchoscopy (15), computed tomography (10), and magnetic resonance imaging (3). As first described by Idriss in 1984, the surgical technique uses a median sternotomy approach, extracorporeal circulation, bronchoscopic guidance, and the use of pericardium as a tracheal patch. There was one perioperative death of mediastinitis (operative survival, 93%). There were two late deaths caused by complications of tracheostomy (1) and direct laryngoscopy and bronchoscopy (DLB) (1). Follow-up is complete in 12 intermediate-term survivors and ranges from 0.4 to 8.2 years (mean, 4.2 +/- 2.9 years). Five children required multiple DLBs with dilation and excision of granulation tissue; one of these patients underwent tracheoplasty revision 5 months after the initial procedure for residual tracheal rings, and four of these children have had tracheostomies, two temporary and two currently (4 months, 7 years). Seven children had widely patent tracheas observed at follow-up DLB with little or no residual stenosis after tracheoplasty. All survivors are currently asymptomatic, except for the two children with tracheostomies. Pericardial patch tracheoplasty offers effective therapy with relatively low operative mortality for infants and children with severe long segment tracheal stenosis. On intermediate-term follow-up, nearly all survivors are essentially free of symptoms of residual tracheal stenosis.

Valve Replacement in Children: Guidelines for Selection of Prosthesis and Timing of Surgical Intervention

One hundred fifty-nine patients ranging from 3 months to 18 years old (mean, 8.1 +/- 3.7 years) underwent 162 primary valve implantations. A porcine valve was used in 104 patients, a St. Jude Medical valve in 40, and a Björk-Shiley valve in 18. The valve replaced was the aortic in 25 patients, the mitral (systemic atrioventricular [AV] valve) in 43, the pulmonary in 71, and the tricuspid (pulmonary AV valve) in 23. Hospital mortality was 6%. Patients with a Björk-Shiley valve received warfarin sodium anticoagulation, and those with a St. Jude Medical valve were given salicylates and dipyridamole. Follow-up is available on all patients 0.6 to 12 years postoperatively (mean, 6.3 +/- 2.6 years). New York Heart Association Functional Class improved in 62% and remained unchanged in 38% of the patients. Thromboembolic complications occurred in only 8 (57%) of 14 patients with a St. Jude Medical valve in the right (pulmonary) side and in 3 (12%) of 26 with the valve in the left (systemic) side of the circulation. Bacterial endocarditis developed in 3 patients, all with porcine valves. Early valve replacement, less than 2 years after detection of hemodynamic deterioration, resulted in improvement in the ventricular ejection fraction in 25 of 29 patients (from 81 +/- 14% to 90 +/- 12% of normal; p less than 0.05). In contrast, the ejection fraction remained abnormal in all 22 patients with delayed valve insertion (more than 2 years) (81 +/- 16% of normal preoperatively and 80 +/- 10% of normal following operation; p = not significant).

Surgical Management of Infants with Complex Cardiac Anomalies Associated with Reduced Pulmonary Blood Flow and Total Anomalous Pulmonary Venous Drainage

Eight infants with complex cardiac anomalies and pulmonary stenosis or atresia were noted to have obstructed total anomalous pulmonary venous drainage (TAPVD) either at the initial cardiac catheterization (Group 1; n = 2) or after creation of systemic-pulmonary artery shunts (Group 2; n = 6). The 2 patients in Group 1 underwent early repair of TAPVD (1 at 7 days, the other at 1 1/2 months of age) before any subsequent operation and are now doing well at 18 months of age. The 6 patients in Group 2 underwent repeat cardiac catheterization because of persistent severe cyanosis with faint or absent continuous murmur and were found to have patent shunts and obstructed TAPVD (1 mild, 5 severe). One patient who underwent repair of TAPVD at 2 1/2 months of age survived and is well at 2 years of age, whereas 4 patients who underwent repair at an average age of 6 months (age range, 3-16 months) subsequently died. The sixth patient, who did not undergo repair, remained severely cyanotic with hypoplastic pulmonary arteries in spite of repeated shunts. We feel that increased awareness of the possible association of TAPVD and reduced pulmonary blood flow in infants with complex cardiac defects, in combination with echocardiography, oxygen saturation studies, and angiography with prostaglandin E1 challenge, should lead to early diagnosis, avoidance of unnecessary systemic-pulmonary artery shunts, and increased survival rates in these infants.

Transposition of the great arteries: A comparison of results of the Mustard procedure versus the arterial switch

Sixty infants with transposition of the great arteries and intact ventricular septum underwent primary surgical correction in the first 3 months of life. Twenty-three patients had a Mustard procedure (group 1) and 37 patients, an arterial switch operation (group 2). The mean age at the time of repair was 42 +/- 31 days for group 1 and 8 +/- 6 days for group 2 (p less than 0.001). The mean weight at the time of repair was 3.6 +/- 0.7 kg for group 1 and 3.4 +/- 0.5 kg for group 2 (p = not significant). Operative mortality was 8.7% (2/23) in group 1 and 8.1% (3/37) in group 2 (p = not significant). The incidence of arrhythmias in the early postoperative period was 39% (9/23) in group 1 and 11% (4/37) in group 2 (p less than 0.01). All patients were followed a mean of 4.8 +/- 2.4 years in group 1 and 2.6 +/- 1.4 years in group 2 (p less than 0.001). Postoperative catheterization has been performed in 86% (18/21) of group 1 operative survivors and 50% (17/34) of group 2 operative survivors. Ejection fraction of the systemic ventricle was 79% +/- 15% of predicted normal in group 1 and 98% +/- 6% in group 2 (p less than 0.005). The incidence of late arrhythmias was 57% (12/21) in group 1 and 3% (1/34) in group 2 (p less than 0.001). There have been 2 late deaths in group 1 and 1 late death in group 2 (p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical Management of Patients with Interrupted Aortic Arch and Severe Subaortic Stenosis

Ten patients underwent palliative surgery for interrupted aortic arch and severe subaortic obstruction due to posterior displacement of the conal septum. Their ages ranged between 4 and 28 days (mean, 11.0 +/- 7.7 days) and their weights, between 2.1 and 4.2 kg (mean, 2.85 +/- 0.6 kg). Preoperative echocardiography and cardiac catheterization were performed on all patients. The ratios of the left ventricular outflow tract diameters and the ascending aortic diameters to the descending aortic diameters were 0.56 +/- 0.03 and 0.56 +/- 0.06, respectively, compared with 0.81 +/- 0.12 and 0.95 +/- 0.17, respectively, in 20 patients with interrupted aortic arch but without obstruction (p less than 0.001). Four of the 10 patients underwent pulmonary artery banding and insertion of a bypass graft between the ascending and the descending aorta. All 4 died of low cardiac output soon after operation (100% operative mortality). The remaining 6 patients underwent banding and insertion of a graft between the main pulmonary artery proximal to the band, and the descending aorta. All of these patients survived, and all except 1 are doing well 3 months to 4 years postoperatively. The use of a pulmonary artery-descending aorta conduit and of distal pulmonary artery banding provides good palliation for patients with interrupted aortic arch and major subaortic stenosis.

Long-Term Results of Porcine Valve Insertion for Pulmonary Regurgitation Following Repair of Tetralogy of Fallot

Between January 1975 and January 1985, 49 patients, aged 2 to 20 years, underwent porcine valve insertion for control of pulmonary regurgitation following repair of tetralogy of Fallot. In 9 patients the valve was placed at the time of the repair; in the remaining 40, valve insertion was performed 2 to 5 years postoperatively. The primary indications for valve implantation included progressive cardiomegaly and evidence of right ventricular (RV) dilatation or dysfunction. Operative technique emphasized ample enlargement of the RV outflow tract and main pulmonary artery to allow for insertion of a large valve and prevention of turbulence or stenosis. There was 1 hospital death (2%). Follow-up is available on remaining patients 1 to 10 years postoperatively. Considerable prosthetic valvar stenosis or regurgitation occurred in 7 patients (14%) 3 to 8 years following insertion, including one after subacute bacterial endocarditis. The complication-free actuarial life was 82%, and the functional actuarial life was 84% at 10 years for the prosthesis. The data suggest that the porcine valve has a good long-term durability when inserted in the pulmonary position in pediatric patients.

Surgical options in subaortic stenosis associated with endocardial cushion defects

Over a 15-year period, 12 patients with endocardial cushion defects undergoing correction had subaortic stenosis requiring operative intervention. Ages ranged from 4 months to 17 years (mean, 7 +/- 6 years) and subaortic gradients from 15 to 100 mm Hg (mean, 60 +/- 25 mm Hg). Subaortic stenosis was due to discrete fibromuscular tissues in 7 patients, mitral valve malattachment in 3, and tunnel outflow in 2. In 2, the subaortic stenosis was clinically significant at the time of endocardial cushion defects repair, whereas in 10 it was noted 2 to 14 years postoperatively (mean, 6.3 +/- 5 years). Surgical relief of subaortic stenosis was accomplished by resection of muscle tissues in 7, apicoaortic conduit insertion in 2, modified Konno procedure (aortic valve preserved) in 2, and lifting of malattached mitral valve from the outflow in 1. There was no early death and one late death (infected conduit). Severe mitral insufficiency developed in the patient who had the mitral valve lifted and necessitated valve replacement. Postoperative echocardiographic gradient in 9 patients ranged from 0 to 36 mm Hg (mean, 10.5 +/- 14 mm Hg). Clinically significant subaortic stenosis has not developed in any patient in 15 years of follow-up (mean, 5 +/- 4 years). We conclude that in subaortic stenosis associated with endocardial cushion defects, resection is effective for discrete obstruction, whereas a modified Konno procedure is preferable for obstruction due to tunnel outflow or mitral valve malattachment.