Biomedical subjects

M N Ilbawi

Publications and source records attributed to M N Ilbawi.

At least 19 recordsLinked to original sources

PubMed2002

Aortic aneurysm after patch aortoplasty for coarctation: analysis of patch size and wall growth.

Aortic aneurysm may develop after surgery for coarctation of aorta especially patch aortoplasty. The size of patch and of adjacent native aortic wall was analyzed to determine whether aortic dilatation represents a true aneurysm. Electron beam tomography (EBT) was done on 19 patients, three months to 17.5 years after patch aortoplasty. Tomograms of aorta were obtained in 6-mm slices, and maximal cross-sectional area was digitized to obtain: total circumference (Ct), patch component (Cp), and aortic wall component (Cw). Ct, Cp, and Cw were normalized to the circumference of distal aorta (Cda) as: isthmus/distal aorta (Ct/Cda), patch segment/distal aorta (Cp/Cda), wall segment/distal aorta (Cw/Cda). Ct/Cda ranged from 109% to 260%. In 12 patients (group A), it varied from 168% to 260%; and in seven (group B), 109% to 133%. There was strong correlation (r = 0.92) between Ct/Cda and Cp/Cda. Ct/Cda, Cp/Cda, and Cp/Cw were higher in group A than B (p <0.001) but Cw/Cda did not differ. Cw/Cda was greater than the coarctation/distal aorta diameter ratios of preoperative angiograms, consistent with accelerated aortic wall growth postsurgery. No definite aneurysm was seen. Localized dilatation of aorta following patch aortoplasty in children is primarily due to a large synthetic patch and, partly, to increased aortic wall growth. Serial EBT or magnetic resonance imaging is indicated to monitor aortic wall growth and occurrence of aneurysm.

Angioplasty↗

PubMed2001

Pediatric myocardial protection: an overview.

This article describes the experimental infrastructure and subsequent successful clinical application of a comprehensive bypass and cardioplegic strategy that limits intraoperative injury and improves postoperative outcomes in pediatric patients. The infant heart is at high risk of damage from poor protection because of preoperative hypertrophy, cyanosis, and ischemia. The background factors of vulnerability to damage caused by cyanosis and ischemia are discussed, together with studies of the infrastructure of strategies to use normoxia versus hyperoxia as bypass starts, white blood cell filtration, warm induction and reperfusion with substrate enhancements, multidose blood cardioplegia, and an integrated approach to allow ischemia only when vision is needed in pediatric surgeries. Data on cardioplegic management, including reducing calcium, increasing magnesium, and reducing perfusion pressure are shown, as used during this technique. These principles were applied to a consecutive series of 567 patients at the Heart Institute for Children and University of Illinois hospital over a 2-year period. Included also were 72 patients with hypoplastic left heart over a 4-year period with this myocardial management strategy. Application of these concepts may improve the safety of protection in infant hearts.

Animals↗

PubMed2001

Hypoxia, reoxygenation and the role of systemic leukodepletion in pediatric heart surgery.

As cardiopulmonary bypass (CPB) in infants and neonates is becoming more frequent, the technical performance of these operations for congenital heart disease has made significant progress. However, little research has been carried out into the conduct of CBP in producing myocardial and pulmonary dysfunction. Postoperative organ dysfunction is a problem, particularly for cyanotic infants. This paper examines the experimental and clinical experience of injury brought about by abrupt reoxygenation of the hypoxic, or cyanotic, heart. The modalities of gradual reoxygenation and leukodepletion in limiting this injury are examined, leading to the conclusion that injury can be reduced and possibly ameliorated by changes in intraoperative management during CBP in children with cyanotic disease.

Animals↗

PubMed2000

The role of cardioplegia induction temperature and amino acid enrichment in neonatal myocardial protection.

BACKGROUND: Warm cardioplegic induction improves the ischemically "stressed" adult heart. However, it is rarely used in infants, despite the fact that many newborn hearts are stressed by other factors such as hypoxia. The need for amino acids as well as their mechanism of action has also not been studied. METHODS: We first assessed the role of cardioplegic induction temperature in 10 nonhypoxic neonatal piglets undergoing 70 minutes of multidose blood cardioplegic arrest. Five piglets (group 1) received a cold (4 degrees C) induction, and 5 (group 2) a warm (37 degrees C) induction. Twenty-six other piglets underwent ventilator hypoxia (fraction of inspired oxygen, 8% to 10%) for 60 minutes before cardiopulmonary bypass (stress). Six piglets (group 3) then underwent 70 minutes of cardiopulmonary bypass without ischemia (hypoxia controls), and 20 underwent 70 minutes of cardioplegic arrest. Five of these (group 4) received cold cardioplegic induction, and 15 received warm induction; in 5 of these (group 5), the warm cardioplegic solution contained amino acids, in 5 others (group 6), it was unsupplemented, and in the remaining 5 (group 7), nitroglycerin was added to determine the role of vasodilation. Myocardial function was assessed by pressure-volume loops (expressed as a percent of control), and coronary vascular resistance was measured with cardioplegic infusions. RESULTS: In nonhypoxic (normal) piglets, cold (group 1) and warm (group 2) induction completely preserved systolic function (end-systolic elastance, 100% versus 104%) and preload recruitable stroke work (100% versus 102%), with minimal increase in diastolic compliance (162% versus 156%). Hypoxia-reoxygenation alone (group 3) depressed systolic function (end-systolic elastance, 51%+/-2%) and preload recruitable stroke work (54%+/-3%), and raised diastolic stiffness (260%+/-15%). The detrimental effects of reoxygenation persisted (unchanged from reoxygenation alone) with cold induction (group 4) or warm induction without amino acids (groups 6 and 7). In contrast, warm induction with amino acids (group 5) restored systolic function (end-systolic elastance, 105%+/-3%; p < 0.001 versus groups 3, 4, 6, and 7) and preload recruitable stroke work (103%+/-2%; p < 0.001 versus groups 3, 4, 6, and 7), and decreased diastolic stiffness (154%+/-7%; p < 0.001 versus groups 3, 4, 6, and 7). However, there was no difference in myocardial oxygen consumption in hypoxic hearts receiving a warm induction (6.9 versus 6.5 versus 7.3 mL/g per 5 minutes) (groups 5, 6, 7), and coronary vascular resistance was lowest with nitroglycerin (group 7). CONCLUSIONS: Cardioplegic induction can be given either warm or cold in nonhypoxic neonatal hearts. In contrast, only warm induction with amino acids repairs the hypoxic injury, but the primary mechanism of action is not related to increased metabolic activity or vasodilation.

Adenosine↗

PubMed2000

Reducing postischemic reperfusion damage in neonates using a terminal warm substrate-enriched blood cardioplegic reperfusate.

BACKGROUND: In adult cardiac operations, a warm cardioplegic reperfusate ("hot shot") before removing the aortic cross-clamp improves postbypass myocardial function and metabolic recovery. This modality, however, is rarely used in infants, despite the fact that postbypass cardiac dysfunction remains problematic, especially in cyanotic ("stressed") patients. METHODS: To produce stress, 15 neonatal piglets underwent 60 minutes of ventilator hypoxia (fraction of inspired oxygen, 8% to 10%). All piglets then received similar protection with multidose cold blood cardioplegic solution during 70 minutes of arrest and were separated into three groups to examine the role of a warm reperfusate as well as possible augmentation by aspartate and glutamate enrichment. In 5 piglets (group 1), the cross-clamp was simply removed; in 5 (group 2), an unsupplemented warm blood cardioplegic reperfusate was given; and in 5 (group 3), the warm reperfusate was enriched with aspartate and glutamate. Myocardial function was assessed using pressure-volume loops and expressed as a percentage of control. RESULTS: Compared with hearts receiving reperfusion with unmodified blood (group 1), a warm unsupplemented cardioplegic reperfusate (group 2) slightly improved systolic contractility (end-systolic elastance, 41% versus 50%; p < 0.05 versus group 1) and preload recruitable stroke work (41% versus 52%; p < 0.05 versus group 1), reduced diastolic stiffness (263% versus 245%; p < 0.05 versus group 1), and increased adenosine triphosphate (10.7 versus 11.9 microg/g tissue, p < 0.05 versus group 1). However, if aspartate and glutamate was included in the warm reperfusate (group 3), there was complete recovery of systolic function (end-systolic elastance, 105%+/-3%; p < 0.001 versus all groups) and preload recruitable stroke work (103%+/-2%; p < 0.001 versus all groups), a minimal rise in diastolic stiffness (154%+/-7%; p < 0.001 versus all groups), and preservation of adenosine triphosphate (15.5+/-0.5 microg/g; p < 0.001 versus all groups). CONCLUSIONS: A warm cardioplegic reperfusate helps reduce the reperfusion injury, resulting in improved myocardial function and metabolic recovery in hypoxic (stressed) neonatal hearts, and this effect is maximized if the reperfusate is enriched with aspartate and glutamate, which completely preserves myocardial function.

Adenosine Triphosphate↗

PubMed2000

Modification of the subclavian patch aortoplasty for repair of aortic coarctation in neonates and infants.

BACKGROUND: Coarctation repair in neonates or small infants, using a subclavian patch, has a relatively high risk of restenosis, especially if complicated by the presence of a short subclavian artery or long coarctation segment. We introduce a technical modification that facilitates the use of a subclavian flap, and decreases the restenosis rate in this subgroup of patients. It consists of a side-to-side transverse aortic anastomosis at the level of the coarctation, which widens the coarctation segment, shortens the isthmus, and pulls the distal end of the aortotomy proximally, allowing a tension-free subclavian flap aortoplasty. METHODS: Fifty-three consecutive neonates or infants less than 18 weeks old, with complex coarctation, underwent repair using this technique. Mean age was 26+/-3 days and 36 patients (68%) were less than 28 days old. Weights ranged from 1.4 to 6.4 kg (mean 3.4+/-0.2 kg), and 26 patients had other cardiac anomalies. Preoperative gradient by Doppler measurement ranged from 25 to 90 mm Hg (mean 49+/-2 mm Hg). RESULTS: Mean aortic cross-clamp time was 27+/-1 minutes (range 19 to 34 minutes). There were no deaths or surgical complications. Follow-up echocardiogram 4 to 52 months postoperatively (mean 25+/-2 months) demonstrated no significant pressure gradient (less than 20 mm Hg) in 51 of 53 patients (96%), and a significant gradient in 2 patients (4%), which was subsequently corrected with balloon angioplasty. CONCLUSIONS: The technical modification described shortens the isthmus, and thus allows for a longer aortotomy distal to the area of coarctation resulting in a tension-free repair especially in patients with a short subclavian artery. It also widens the area of coarctation, and as a result leads to a lower early recoarctation rate in this high-risk group. With increasing emphasis on the need for a longer aortotomy to prevent restenosis, this modification will have increasing application, especially in the neonatal population.

Aortic Coarctation↗

PubMed1999

Superiority of magnesium cardioplegia in neonatal myocardial protection.

BACKGROUND: We have shown that magnesium can offset the detrimental effects of normocalcemic cardioplegia in hypoxic neonatal hearts. It is not known, however, whether magnesium offers any additional benefit when used in conjunction with hypocalcemic cardioplegia. METHODS: Twenty neonatal piglets underwent 60 minutes of ventilator hypoxia (FiO2 8% to 10%) followed by 20 minutes of normothermic ischemia on cardiopulmonary bypass (hypoxic-ischemic stress). They then underwent 70 minutes of multidose blood cardioplegic arrest. Five (Group 1), received a hypocalcemic (Ca+2 0.2 to 0.4 mM/L) cardiologic solution without magnesium, whereas in 10, magnesium was added at either a low dose (5 to 6 mEq/L, Group 2) or high dose (10 to 12 mEq/L, Group 3). In the last 5 (Group 4), magnesium (10 to 12 mEq/L) was added to a normocalcemic cardioplegic solution. Function was assessed using pressure volume loops and expressed as percentage of control. RESULTS: Compared to hypocalcemia cardioplegic solution without magnesium (Group 1), both high- and low-dose magnesium enrichment (Groups 2 and 3) improved myocardial protection resulting in complete return of systolic (40% vs 101% vs 102%) (p < 0.001 vs Groups 2 and 3) and global myocardial function (39% vs 102% vs 101%) (p < 0.001 vs Groups 2 and 3), and reduced diastolic stiffness (267% vs 158% vs 154%) (p < 0.001 vs Groups 2 and 3). Conversely, even high-dose magnesium supplementation could not offset the detrimental effects of normocalcemic cardioplegia resulting in depressed systolic (End Systolic Elastance [EES] 41%+/-1%) (p < 0.001 vs Groups 2 and 3) and global myocardial function (40%+/-1%) (p < 0.001 vs Groups 2 and 3), and a marked rise in diastolic stiffness (258%+/-5%) (p < 0.001 vs Groups 2 and 3). Hypocalcemic magnesium cardioplegia has now been used successfully in 247 adult and pediatric patients. CONCLUSIONS: Magnesium enrichment of hypocalcemic cardioplegic solutions improves myocardial protection resulting in complete functional preservation. However, magnesium cannot prevent the detrimental effects of normocalcemic cardioplegia when the heart is severely stressed. This study, therefore, strongly supports using both a hypocalcemic cardioplegic solution and magnesium supplementation as their benefits are additive.

Adenosine Diphosphate↗

PubMed1997

Detrimental effects of cardiopulmonary bypass in cyanotic infants: preventing the reoxygenation injury.

BACKGROUND: Recent experimental studies have shown that acute hypoxia followed by abrupt reoxygenation using cardiopulmonary bypass (CPB) results in an unintended injury mediated by oxygen free radicals, which can be modified by initiating CPB at a lower fraction of inspired oxygen (FiO2) or by leukocyte filtration. However, the clinical relevance of these experimental studies has been questioned because chronic hypoxia may allow compensatory changes to occur. METHODS: Seven acyanotic infants had CPB initiated at an FiO2 of 1.0. Of 21 cyanotic infants, 7 (group 1) had CPB initiated at an FiO2 of 1.0, 6 (group 2) at an FiO2 of 0.21, and 8 (group 3) underwent CPB using leukocyte filtration. Biopsy of right atrial tissue was performed before and 10 to 20 minutes after the initiation of CPB. The tissue was incubated in 4-mmol/L t-butylhydroperoxide (a strong oxidant), and the malondialdehyde (MDA) level was measured to determine the antioxidant reserve capacity. The more MDA produced, the greater was the depletion of tissue antioxidants secondary to oxygen free radical formation during reoxygenation. RESULTS: There was no difference in the prebypass antioxidant reserve capacity between cyanotic and acyanotic hearts (492 +/- 72 versus 439 +/- 44 nmol MDA/g protein). However, after the initiation of CPB without leukocyte filtration, MDA production rose markedly in the cyanotic (groups 1 and 2) as compared with the acyanotic hearts (322% versus 40%; p < 0.05), indicating a depletion of antioxidants. In cyanotic hearts, initiating CPB at an FiO2 of 1.0 (group 1) resulted in increased MDA production (407% versus 227%) as compared with hearts in which CPB was initiated at an FiO2 of 0.21 (group 2), indicating a greater generation of oxygen free radicals in group 1. Conversely, there was only a minimal increase in MDA production in 8 of the 21 infants (group 3) in whom white blood cells were effectively filtered (19% versus 322%; p < 0.05). CONCLUSIONS: First, increased amounts of oxygen free radicals are generated in cyanotic infants with the initiation of CPB. Second, this production is reduced by initiating CPB at an FiO2 of 0.21 or by effectively filtering white blood cells. Third, these changes parallel those seen in the acute experimental model, validating its use for future study.

Antioxidants↗

PubMed1997

Alternative techniques for surgical management of recoarctation.

OBJECTIVE: To evaluate the different surgical options in patients with recoarctation and minimal collaterals. METHODS: Thirty-three cases operated on between January 1980 and January 1995 were reviewed. Initial repair was end-to-end anastomosis in 16 patients, subclavian artery aortoplasty in 10, synthetic patch aortoplasty in 4 and bypass conduit in 3 patients. Age at reoperation was 7.5 +/- 5.2 years (1-17 years). Pressure gradient was 20-48 Torr (33 +/- 9). Upper extremity resting or exercise systemic hypertension was present in all. In 18 patients recoarctation was repaired using subclavian artery aortoplasty (n = 15) or synthetic patch aortoplasty (n = 3); alone in 9, with temporary heparinized bypass in 2, or in addition to placement of ascending aorta to descending aorta conduit as a permanent bypass through a left thoracotomy in 9. In 13 patients a conduit was interposed between ascending aorta and descending aorta through a right thoracotomy. In one patient recoarctation segment was patched on cardiopulmonary bypass through a midsternotomy. RESULTS: There was no mortality or complications. All patients had no echocardiographic pressure gradients across recoarctation on 5 +/- 3.4 years follow-up. Persistent systemic hypertension following recoarctation repair was present in 3/8 patients (37%) operated on at age greater than 10 years, but has been resolved in all 25 patients less than 10 years of age (P = 0.02). CONCLUSIONS: Use of ascending aorta to descending aorta conduit, either alone through a right thoracotomy, or as permanent bypass in combination with patching the recoarctation through a left thoracotomy provides safe and excellent relief of obstruction.

Adolescent↗

PubMed1996

Latent hypoparathyroidism in children with conotruncal cardiac defects.

BACKGROUND: DiGeorge anomaly is characterized by hypoplasia or atresia of the thymus and parathyroid glands resulting in T cell-mediated deficiency, hypocalcemic hypoparathyroidism, and conotruncal cardiac defects. It usually is associated with deletions of chromosomal region 22q11. We hypothesized that the stimulated (secretory reserve) but not the constitutive secretion of parathyroid hormone would be reduced in normocalcemic children with conotruncal cardiac defects but no overt immune deficiency and would be related to the presence of a deletion in the DiGeorge chromosomal region of 22q11. METHODS AND RESULTS: Blood-ionized calcium and serum-intact parathyroid hormone were measured at baseline and seven more times during hypocalcemia induced during cardiopulmonary bypass in 22 patients and 10 control subjects with an atrial septal defect. Chromosomal deletions were detected by fluorescent in situ hybridization and DNA dosage analysis. There were no differences in basal calcium and parathyroid hormone levels between patients and control subjects. All had increased parathyroid hormone in response to hypocalcemia; despite lower calcium levels, parathyroid hormone levels were lower in patients. The parathyroid hormone secretory reserve in 14 of 22 patients was reduced compared with control subjects; 4 of the 14 had deletions. CONCLUSIONS: A significant number of children with conotruncal cardiac defects have normocalcemia and a normal constitutive level of parathyroid hormone but deficient parathyroid hormone secretory reserve; about 30% also have 22q11 deletions. Such children may be at risk for the later development of hypocalcemic hypoparathyroidism.

Adolescent↗

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

Diaphragm pacing with a quadripolar phrenic nerve electrode: an international study.

We sought to determine the international experience with the quadripolar diaphragm pacer system and to test two hypotheses: the incidence of pacer complications would be (1) increased among pediatric as compared to adult patients; and (2) highest among active pediatric patients with idiopathic congenital central hypoventilation syndrome (CCHS). Data were collected via a questionnaire coupled with the Atrotech Registry data for a total of 64 patients (35 children and 29 adults) from 14 countries. Thoracic implantation of electrodes and bilateral pacer use each occurred in 94% of all subjects. Tetraplegic (vs pediatric CCHS) patients were more typically paced 24 hours/day (P = 0.001). Pacing duration averaged 2.0 +/- 1.0 years among children and 2.2 +/- 1.1 years among adults. Infections occurred among 2.9% of surgical procedures, all in pediatric CCHS patients (vs pediatric tetraplegic patients, P = 0.01). The incidence of mechanical trauma was 3.8%, without significant differences among patient groups. The incidence of presumed electrode and receiver failure were 3.1% and 5.9%, respectively, with internal component failure greater among pediatric CCHS than pediatric tetraplegic patients (P < 0.01). Intermittent or absent function of 0-4 electrode combinations occurred among 19% of all patients, with increased frequency among pediatric CCHS than pediatric tetraplegic patients (P < 0.03). Complication-free successful pacing occurred in 60% of pediatric and 52% of adult patients. In all, 94% of the pediatric and 86% of the adult patients paced successfully after the necessary intervention. Although pacer complications were not increased among pediatric as compared to adult patients, the incidence of complications was highest among the active pediatric patients with CCHS. Longitudinal study of these patients will provide invaluable information for modification and improvement of the quadripolar system.

Adult↗

PubMed1995

Alternatives in biventricular repair of double-outlet left ventricle.

Wide variation in morphology of double-outlet left ventricle allows numerous surgical alternatives that require sorting out to develop a more organized approach. There is a high association between tricuspid abnormalities and right ventricular hypoplasia with double-outlet left ventricle that calls for either Fontan-type procedure or biventricular repair. With pulmonic stenosis, biventricular repair has been accomplished using right-sided conduits. When pulmonic stenosis is mild or absent, repair techniques without conduits depend on the commitment of the ventricular septal defect (VSD). With subaortic VSD and mild pulmonic valvar stenosis, we successfully performed translocation of the main pulmonary artery and valve to the right ventricle on 2 patients (ages 32 and 8 months). Both patients are doing well 2 years and 1 year postoperatively. Others have successfully connected the right ventricle to the pulmonary artery with intraventricular baffle by enlarging a subaortic VSD or when the VSD is either subpulmonic or doubly committed. With subaortic VSD, although it has not been reported, biventricular repair can also be accomplished using a right ventricle-to-aorta baffle combined by either atrial or arterial switch. We believe that a simplified management plan can be formed in double outlet left ventricle based on the size of the right ventricle, presence of pulmonic stenosis, and commitment of the VSD. Whenever possible, translocation of the main pulmonary artery and valve or intraventricular repair should be accomplished in double-outlet right ventricle minimizing the use of right-sided conduits and reoperation.

Cardiac Surgical Procedures↗

PubMed1994

Transsternal repair of coarctation and associated cardiac defects.

Over a 13-year period, 20 infants and children underwent transsternal approach for repair of coarctation and associated cardiac defects. Fifteen patients (75%) were operated on in the last 6 years. Thirteen patients (group 1) had intracardiac shunts and 7 (group 2), intracardiac obstruction or valvular insufficiency. Group 1 had a mean age of 0.8 +/- 1.9 years versus 4 +/- 3 years for group 2 (p = 0.05). There were 12 patients (92%), 7 months old or less in group 1. Aortic arch hypoplasia was present in 6 patients in group 1. A large patent ductus arteriosus was present in 5 of these 6 patients versus no patent ductus arteriosus in patients without aortic arch hypoplasia (p = 0.006). The mean pulmonary blood flow to systemic blood flow ratio in group 1 was 3.8 +/- 2 and the mean right ventricular to left ventricular ratio, 0.8 +/- 0.2. The coarctation repair fell mostly into three types: side patch aortoplasty (8), ductal tissue excision and patch aortoplasty of the concavity of the aortic arch (6), and subclavian aortoplasty (4). There was one early death (5%) which was due to sepsis in a newborn. Another newborn who had subclavian aortoplasty needed a left carotid artery--descending aorta bypass conduit early because of aortic arch hypoplasia. All patients were followed to 12 years (mean follow-up, 4.3 +/- 3.5 years). There were no late deaths. Two patients had recurrent coarctation, 1 after an end-to-end repair and the other because of incomplete arch enlargement after a side patch aortoplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta, Thoracic↗

PubMed1994

Management of hypoplastic aortic arch associated with neonatal coarctation.

Controversy still exists as to whether hypoplastic aortic arch frequently associated with neonatal coarctation, should be enlarged at the time of coarctation repair. To determine the indications for and the outcome of repair of hypoplastic aortic arch, pre- and postoperative angiograms/echocardigraphy of 77 cases with isolated (n = 25, Group 1) or complex (n = 52, Group 2) neonatal coarctation operated upon between 1/80 and 12/89 were reviewed. Age was 5-14 days (mean 8 +/- 1.6). Aortic arch/ascending aorta diameter ratio (AR/AA) as a measure of the degree of aortic arch hypoplasia was 0.39-0.64 (0.52 +/- 0.04) in isolated and 0.15-0.47 (0.34 +/- 0.06) in complex coarctation (p < 0.05). Left subclavian flap aortoplasty was used in 72 patients; alone in 25, in combination with pulmonary artery banding in 43 patients, and simultaneously with intracardiac repair in 4 patients. Extensive reconstruction of aortic arch and coarctation with synthetic patch was performed in the remaining 5 patients (AR/AO = 0.16 +/- 0.03) using cardiopulmonary by-pass at the time of intracardiac repair. Operative mortality was 2/76 (2.5%). Follow-up is 6.6 +/- 1.4 years. Recoarctation occurred in 3 patients (4%). AR/AA increased to 0.86 +/- 0.1 in isolated (p < 0.05 vs preoperative) and to 0.7 +/- 0.1 in complex coarctation (p < 0.05 vs preoperative). In the majority of cases, hypoplastic aortic arch associated with coarctation grows satisfactorily following simple repair of coarctation with no significant residual narrowing.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

PubMed1994

Extended aortic valvuloplasty for recurrent valvular stenosis and regurgitation in children.

Recurrent significant aortic valvular stenosis or regurgitation, or both, after balloon or open valvotomy in pediatric patients often necessitates aortic valve replacement. In an attempt to preserve the aortic valve, we performed extended aortic valvuloplasty in 21 children with recurrent aortic valve stenosis or regurgitation from January 1989 to March 1993. Previous related procedures were one open aortic valvotomy or more (n = 15), balloon valvotomy (n = 4), balloon valvotomy after surgical valvotomy (n = 1), and repair of iatrogenic valve tear (n = 1). Mean age at the time of the extended aortic valvuloplasty was 6 +/- 3.4 years. Mean pressure gradient across the aortic valve was 56 +/- 12 torr. Regurgitation was moderate (grade 2 to 3) in nine and severe (grade 4) in 12 patients. Extended aortic valvuloplasty techniques consisted of thinning of valve leaflets (n = 15), augmentation of scarred and retracted leaflets with autologous pericardium (n = 11), resuspension of the augmented leaflet (n = 14), release of the rudimentary commissure from the aortic wall (n = 5), extension of the valvotomy incision into the aortic wall on both sides of the commissure (n = 20), patch repair of the sinus of Valsalva perforation (n = 1), reapproximation of tears (n = 5), and narrowing of the ventriculoaortic junction (n = 2). No operative deaths occurred. The postoperative mean pressure gradient, assessed by most recent Doppler echocardiography or cardiac catheterization at a follow-up of 18 +/- 6 months, was 19 +/- 6 torr (p < 0.01 versus the preoperative gradient). Aortic regurgitation was absent in 13, mild in 6, and moderate-to-severe, necessitating subsequent aortic valve replacement, in 2. This short-term experience indicates that extended aortic valvuloplasty is a safe and effective surgical approach that minimizes the need for aortic valve replacement in children with significant recurrent aortic valve stenosis or regurgitation.

Actuarial Analysis↗

PubMed1993

Surgical techniques in partial anomalous pulmonary veins to the superior vena cava.

Over a 12-year period, 40 patients underwent repair of partial anomalous pulmonary veins (PAPV) draining to the superior vena cava (SVC) proximal to the sinus node. Mean age was 6 +/- 2 years. In all patients, the SVC was cannulated superior to the PAPV, which were baffled with pericardium to left atrium. Six patients had associated defects repaired. In 18 patients (group I), an incision was made at the crest of the right atrial appendage (RAA) and extended upward through the sinus node and to the SVC. After rerouting of the PAPV, the SVC was enlarged using the RAA (atriocavoplasty). In 17 patients (group II), rerouting of the PAPV was accomplished through a right atriotomy. Superior vena caval enlargement was not done. Drainage of the PAPV was close to the right atrium in 14 patients (low) and to the azygos vein (high) in 3. In 5 patients (group III), an incision was made on the SVC and RAA sparing the sinus node. After rerouting of the PAPV, the RAA was anastomosed to the SVC (end to side), providing another outlet for SVC flow. There was no early or late death. Two patients (10%) in group I had late sinus bradycardia. Obstruction of the SVC and PAPV developed in 1 patient in group II with high drainage. Intermittent complete heart block developed in 1 patient in group III who also had ventricular septal defect repair. We conclude that atriocavoplasty is effective for rerouting of the PAPV and enlarging the SVC, but may predispose to sinus node disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1993

Biventricular repair of hypoplastic right ventricle assisted by pulsatile bidirectional cavopulmonary anastomosis.

The right ventricle in patients with severe outflow obstruction or atresia and a small tricuspid valve often remains too hypoplastic even after optimal palliation to tolerate biventricular repair with closure of the atrial septal defect. In these patients, nonpulsatile cavopulmonary (Glenn) anastomosis has traditionally facilitated biventricular repair. In 1989, Billingsley and associates reported the addition of a bidirectional cavopulmonary anastomosis to the definitive biventricular repair in patients with hypoplastic right ventricle, pulmonary atresia, and intact ventricular septum. The atrial septal defect was left open with an adjustable snare for later closure. We report five patients with hypoplastic right ventricle (mean diastolic volume 48.4%, mean stroke volume 40.2% of predicted value) who had the atrial septal defect closed at the time of the biventricular repair. Four patients, who had the bidirectional cavopulmonary anastomosis supplementing the biventricular repair, had no evidence of excessive right atrial or superior vena cava hypertension postoperatively. One patient, who had atypical tetralogy of Fallot with tricuspid stenosis, developed recurrent pericardial tamponade and marked hepatomegaly following conventional tetralogy repair with closure of the atrial septal defect. These complications were controlled with the addition of bidirectional cavopulmonary anastomosis 2 months later. Postoperative hemodynamic or Doppler studies in these patients revealed pulsatile flow in the entire pulmonary artery system, including the artery distal to the Glenn anastomosis. This modification of biventricular repair allows primary closure of the atrial septal defect and provides pulsatile arterial flow in the entire pulmonary artery, even when the right ventricle is significantly hypoplastic.

Adult↗