Pattern of cerebral ultrasound in neonatal heart surgery

AIM

No study described reliably the changes in cerebral ultrasound (CUS) findings in neonatal heart surgery. We tried to define the modifications of CUS before and after heart surgery in neonates.

PATIENTS

We studied 48 neonates with congenital heart defects were studied. Of these, 33 had correction of the malformation with cardiopulmonary bypass (CPB group); 15 underwent coarctation repair/shunting procedures (no-CPB group). Patients had CUS pre-operatively, 48-72 hours after surgery, and at discharge.

RESULTS

Pre-operative studies did not show significant differences between the groups. In CPB group, preoperatively, 6/33 infants showed echogenicity of basal ganglia and 1/33 grade I IVH. In the early postoperative evaluation, 24/33 infants had abnormal scans: increased echogenicity of basal ganglia in 24 and grade I IVH in 14. At discharge, abnormal scans persisted in 20/33 (basal ganglia echogenicity in 20, grade I IVH in 12). In the no-CPB group, preoperatively, 1/15 infant showed echogenicity of basal ganglia. In the early postoperative evaluation, 6/15 had abnormal scans: increased echogenicity of basal ganglia in 6, grade I IVH in 4. At discharge, abnormal scans persisted in 3/15.

CONCLUSIONS

CUS after neonatal heart surgery shows a definite pattern of increased echogenicity of the basal ganglia, more consistent after CPB. These changes may reflect disturbances of deep grey matter, and last 10-15 days at least.

[Right ventricular restoration in adult patients after TOF surgery]

OBJECTIVE

Pulmonary regurgitation may cause progressive right ventricular dilatation and dysfunction in adult patients previously repaired for tetralogy of Fallot. To assess the optimal surgical timing, the impact of the right ventricular restoration with a new surgical ventriculoplasty technique is evaluated following TFO repaired adult patients with severe pulmonary regurgitation and right ventricular dilatation.

METHODS

Sixteen patients with severe pulmonary valve regurgitation (PVR) and right ventricular dilatation with RVOT aneurysm underwent right ventricular remodelling since January 2002. Each underwent preoperative evaluation by Doppler echocardiography, magnetic resonance imaging (MRI), and right ventricular myocardial acceleration during isovolumic contraction (IVC). The surgical procedure included pulmonary valve implantation and RVOT restoration achieved by removal of the aneurysm tissue, coupled with a ventriculoplasty to reduce volume, accomplished by creating a satisfactory RVOT dimension by placing with 2-0 Gortex suture to allow acceptance of a 26 Hegar dilator to avoid restriction. Nine patients had associated surgical procedures.

RESULTS

All patients survived the operative procedure and underwent a 16-month follow-up interval. A reduction of cardio thoracic index and a clinical improvement occurred in each patient. Significant reduction of RVEDV and RVESV and increased right ventricular ejection fraction was observed.

CONCLUSIONS

This preliminary database implies that the right ventricular restoration is a simple and effective procedure, and introduces a structural component that should be added in repaired TFO patients with right ventricular dilatation and underlying aneurysm or akinesia of the right ventricular outflow tract.

Octreotide in the management of postoperative chylothorax

Chylothorax (KT) may be a complication of thoracic surgery. Its management is not well established and may comprise dietary interventions and surgery. The effectiveness of somatostatin and its analogues has been reported, although their mechanism(s) of action is unclear. We report our experience with octreotide in a series of patients with postoperative chylothorax. Eight patients with KT were treated with a continuous intravenous infusion of octreotide (OCT) at a starting dose of 0.5 microg/kg/hr. They were compared with four additional patients with KT who were treated according to the conventional approach. After a mean of 3.3 +/- 1.9 days of treatment, fluid discharge diminished dramatically. In all patients, fluid losses stopped by postoperative day 10.5 +/- 2.9 and chest tubes could be removed after 12.8 +/- 4.1 days. Compared to a small group of historical controls, OCT reduced significantly the total fluid losses (141.1 +/- 89.3 vs 396.7 +/- 151.0 ml/kg; p = 0.003) and the postoperative length of stay (p = 0.05). No patients in the group treated with OCT required parenteral nutrition (compared to all four of the controls; p = 0.002) and/or thoracenteses (compared to two of four controls). In postoperative KT, OCT seems to be at least as effective as the conventional approach. Furthermore, OCT may reduce total fluid losses and postoperative length of stay. This may have a beneficial effect on the risk of complications and on hospital costs.

Growth after neonatal arterial switch operation for D-transposition of the great arteries

The objective of this study was to evaluate growth in infants with d-transposition of the great arteries (d-TGA) who underwent switch operation (anatomical correction) in the early neonatal period. Growth data (at birth and 1, 3, 6, 12, and 24 months of age) were retrieved in 23 infants with d-TGA who survived the operation without major complications. Measures were transformed into z scores and compared with normative data for age. Following surgery, infants showed low z scores for weight, height, and head circumference. Weight and height showed a trend to reach normal ranges between 6 and 12 months of age, and the z scores were positive at 24 months. z scores for head circumference were still negative at 24 months of age. No dietary interventions were implemented during this period, and the infants were fed their own mothers' milk or, before discharge, high-calorie, preterm formula. Following anatomical correction for d-TGA in the early neonatal period, infant growth shows a characteristic pattern, with parameters normalized by 12 months of age in most cases. Head growth shows a different pattern, although gross motor development seems unaffected.

[Clinical course of pre- and post-natal isolated congenital atrioventricular block diagnosed in utero]

We evaluated the pre- and postnatal outcome of isolated atrioventricular (AV) block detected during fetal life in order to identify factors that may affect the natural history of this lesion and to assess prenatal therapy. Over the past eight years, we consecutively evaluated 10 fetuses with complete AV block. The mean gestational age at diagnosis was 25.3 weeks and the mean heart rate was 57 bpm; two fetuses were hydropic. During pregnancy, one fetus suddenly died, while 6 out of 9 fetuses had a mean reduction in heart rate of 17.8 bpm; 4 patients had heart rate < 50 bpm. Five fetuses developed heart failure, which was severe in 2 cases and mild in 3. The mean gestational age at delivery was 31 weeks. Dexamethasone was administered to the mothers during pregnancy in 4 cases without modification of AV block and/or of heart rate, but in 3 out of 4 fetuses the general condition remained stable in spite of the reduction in heart rate in two of them. Sympathomimetic drugs were employed in 3 cases with an increase in fetal heart rate, but maternal discomfort appeared in two cases. Three newborns died during the first week of life, two of hydrops and one of persistent pulmonary hypertension. Cardiac pacing was performed in 6/9 patients within the first 8 months of life and in 3 within the first 2 days. In conclusion, morbidity and mortality are high when AV block is detected during fetal life. Negative prognostic factors are hydrops and a heart rate < 50 bpm. Pre-term delivery to enable cardiac pacing is probably the therapy of choice if gestational age is > 27-28 weeks. Sympathomimetic drugs are effective but are poorly tolerated by the mothers. Dexamethasone has no effect on AV block and/or heart rate, but may improve clinical tolerance of conduction disturbance.

[Immediate and late arrhythmia in patients operated on for tetralogy of Fallot]

Arrhythmias are a frequent complication after repair of tetralogy of Fallot (TOF). We present our experience with 97 patients with special consideration for early and late hyperkynetic arrhythmias. The most frequent, 4% of the patients, was in junctional tachycardia. Late arrhythmias can be atrial or ventricular. The incidence of ventricular arrhythmias in the literature range from 42 to 82%. In the Authors experience multiforme ventricular ectopy was present in 80% of the patients, 20 years after surgery. We suggest an exercise test and averaging ECG in all the patients. Thirty six percent of patients with supraventricular tachycardia were symptomatic.

CONCLUSION

as the incidence of arrhythmias after correction of TOF is high, it is very important to periodically reassess these patients. Antiarrhythmic treatment is indicated in all symptomatic patients, especially in those with major arrhythmias (SVT, AF and VT).

Late reoperations after repair of tetralogy of Fallot

Twenty-two patients underwent 23 late reoperations after total correction of tetralogy of Fallot from 1965 to 1990. Indications for reoperation included: isolated ventricular septal defect (VSD) in 9 patients (41%), isolated right ventricular outflow tract (RVOT) obstruction in 3 patients (13.7%), VSD associated with a RVOT obstruction in 7 patients (31.8%), aneurysm of the pericardial RVOT patch in 1 patient (4.5%), aortic insufficiency with a residual VSD in 1 patient (4.5%), and tricuspid regurgitation in 1 patient (4.5%). The reoperation consisted of closure of a residual VSD in 17 patients, relief of a RVOT gradient in 11, insertion of a RVOT valve in 4, tricuspid valve replacement in 1 (reoperated twice), aortic valve replacement in 1, and excision of a RVOT aneurysm in 1. Two patients died in hospital (9%) but there were no early deaths in the 11 patients reoperated upon after 1978. Mean follow-up period was 135 months. There were 2 late deaths. The actuarial 20-year survival was 87%. Of the surviving patients, 16 (89%) were in New York Heart Association class I, 1 (5.5%) was in class II, and one (5.5%) was in class III. One patient required a second reoperation for tricuspid bioprosthesis degeneration and 1 patient had moderate recurrent RVOT gradient due to calcified pulmonary bioprosthesis. This study tends to support the policy of recommending reoperation in the presence of surgically significant residual defects. Reoperation is associated with a low early mortality and good long-term results.

Combined surgical approach to coexistent carotid and coronary artery disease

Combined coronary artery bypass and carotid endarterectomy were performed in 52 patients (mean age 61 years) between 1981 and 1990. Of these, 36 (69%) had functional class III-IV angina pectoris, 33 (63%) had triple-vessel disease, 36 (69%) had one, or more, previous myocardial infarctions, and 33 (63%) had an abnormal left ventricular function. In 4 cases, additional cardiac procedures were performed. Asymptomatic carotid stenosis was documented in 29 patients (56%) and the remaining 23 (44%) had experienced cerebrovascular symptoms. All patients had hemodynamically significant stenosis of at least one carotid artery, 17 (33%) had severe bilateral carotid artery stenosis, and 6 (11%) had an additional occlusion of the contralateral internal carotid artery. There were no early deaths. Perioperative morbidity included: myocardial infarction in 4 patients (7.7%) and neurological deficit in 3 (5.7%) but functional impairment was not permanent. Late results have been obtained for all 52 patients at a mean postoperative interval of 35 months. Four patients (7.7%) have died, and the 5 year life-table survival rate was 83%. At five years, actuarial curves showed 67% of patients to be free of all serious events or death. Late mortality and morbidity were related above all to the progression of the coronary artery disease. We concluded that simultaneous endarterectomy of significant carotid artery stenosis in candidates for coronary bypass can be done safely and considered as more practical for the patient.

[Echocardiographic evaluation of mitral valve calcification]

Preoperative assessment of calcifications is important in order to choose the correct surgical approach for mitral valve disease. To test the accuracy of echocardiography (ECHO) in the semiquantitative analysis of mitral valve (MV) calcifications we preoperatively echo-studied 66 patients, who were to undergo MV replacement of rheumatic disease. Echocardiograms were performed using a standardized method, recorded on videotape and analyzed by two independent observers. Areas of calcification were identified as dense conglomerate echoes which were brighter than those of adjacent internal structures. After removal, the MVs were evaluated by means of inspection (I), direct radiography (X-ray) and quantitative calcium extraction--EDTA spectrophotometry--(QCa). In the three methods ECHO, I and X-ray, MV calcifications were graded as absent (group 1), mild (group 2) nodular (group 3) and diffuse (group 4). Using the chi square test, no significant differences were found between the three methods, or between ECHO and X-ray, or between ECHO and I, while I grading was slightly lower than X-ray grading (P less than 0.002). Using variance analysis, no significant differences were found in QCa in the three methods within group 1 and 4, whereas significant differences were present within group 2 (P less than 0.002) and group 3 (P less than 0.001), due to the lower sensitivity of I. On the base of the observed distribution of QCa in the removed MVs, the following QCa values: a) less than 20 mg, b) 20-80 mg, c) greater than 80 mg, were considered as the selection criteria for a) absent or mild, b) nodular and c) diffuse calcifications respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical treatment of the aberrant retroesophageal right subclavian artery in adults (dysphagia lusoria). Report of two new cases and review of the literature

Two cases of an aberrant right subclavian artery causing dysphagia lusoria in the adult are presented. The first patient was treated by dividing the aberrant vessel through a right posterolateral thoracotomy and anastomosing the divided subclavian artery to the ascending aorta with a Dacron graft. The second patient, had a simple division of the anomalous vessel through a left posterolateral thoracotomy, but developed a subclavian steal syndrome. These symptoms were relieved by anastomosing the stump of the artery to the ascending aorta with the use of a graft. The world literature is reviewed with reference to the operative treatment of the dysphagia lusoria in adults. A total of twenty surgically treated patients have been recorded. The mechanisms involved in the production of symptoms and the surgical approaches are reviewed and discussed.