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Biomedical subjects

R A Jonas

Publications and source records attributed to R A Jonas.

At least 91 records · Page 5Linked to original sources
PubMed1996

Inhaled nitric oxide in children with pulmonary hypertension and congenital mitral stenosis.

We demonstrated selective pulmonary vasodilation in patients with congenital mitral stenosis with inhaled NO, and used NO as prolonged therapy to stabilize the postintervention course of these children. The pulmonary vasoreactivity was greater than that previously reported in adults and may be due to particular sensitivity of pulmonary veins to inhaled NO when pulmonary venous hypertension has been present since birth.

Administration, Inhalation↗
PubMed1996

Influence of age on cerebral recovery after deep hypothermic circulatory arrest in piglets.

BACKGROUND: In the first weeks of life there are important maturational changes in the central nervous system in many species in energy metabolism, synapse number, and concentration of neuronal excitatory receptors. METHODS: Four groups of 10 piglets (aged 1, 2, 4, and 10 weeks) underwent 1 hour of deep hypothermic circulatory arrest at 15 degrees C, with cooling and rewarming on cardiopulmonary bypass. Cerebral blood flow and metabolic rate measurements and electroencephalographic recordings were obtained from 5 animals per group. The remaining animals underwent cerebral magnetic resonance spectroscopy. RESULTS: Preoperative cerebral blood flow and glucose consumption were higher at 4 and 10 weeks than at 1 and 2 weeks. Cerebral adenosine triphosphate content decreased more rapidly during deep hypothermic circulatory arrest at 4 and 10 weeks. Phosphocreatine recovery was greater at 30 minutes of reperfusion at 10 weeks compared with 1 week. Recovery of cerebral phosphocreatine/ adenosine triphosphate ratio and intracellular pH was remarkably uniform at all ages. Latency to recovery of electroencephalographic activity decreased with increasing age (p = 0.04). CONCLUSIONS: Differences in acute recovery of brain energy metabolism and electroencephalogram after cardiopulmonary bypass and 1 hour of deep hypothermic circulatory arrest in piglets between 1 and 10 weeks of age are small. Further studies are required to correlate these acute findings with subsequent neurologic outcome.

Adenosine Triphosphate↗
PubMed1996

Tetralogy of Fallot with diminutive pulmonary arteries: preoperative pulmonary valve dilation and transcatheter rehabilitation of pulmonary arteries.

OBJECTIVES: This study sought to determine the results of a novel transcatheter management approach in tetralogy of Fallot with diminutive pulmonary arteries. BACKGROUND: Tetralogy of Fallot with diminutive pulmonary arteries and severe pulmonary stenosis is rare and resembles tetralogy of Fallot with pulmonary atresia: There is a high incidence of aortopulmonary collateral channels, arborization abnormalities, stenoses and need for multiple operations. Because a combined catheter-surgery approach facilitates repair in these patients, such an approach may benefit those with diminutive pulmonary arteries and pulmonary stenosis. METHODS: Clinical, catheterization and surgical data were studied retrospectively for 10 such patients undergoing preoperative pulmonary valve balloon dilation, among other transcatheter interventions, from January 1989 to January 1995. RESULTS: Initially, the Nakata index ranged from 20 to 98 mm2/m2 (mean 67 +/- 28 mm2/m2). The pulmonary valve was first balloon dilated (mean balloon/annulus 1.5 +/- 0.3), and the mean initial valve annulus Z score (-4.0 +/- 1) increased to -33 +/- 1.1 (p < 0.01) Other interventions included branch pulmonary artery balloon dilation (7 patients, 23 vessels) and coil embolization of aortopulmonary collateral channels (8 patients, 31 collateral channels). At preoperative follow-up catheterization, the mean pulmonary annulus Z score was -3.1 +/- 0.7, and the Nakata index increased to 143 +/- 84 mm2/m2 (p < 0.03). All patients underwent complete surgical repair successfully. At a mean follow-up period of 2.6 +/- 2 years, right ventricular pressure was < 70% systemic in all patients and < 50% systemic in seven. CONCLUSIONS: In patients with tetralogy of Fallot, severe pulmonary stenosis and diminutive pulmonary arteries, initial pulmonary valve balloon dilation increases the annulus Z score and anterograde pulmonary blood flow and facilities simultaneous coiling of aortopulmonary collateral channels and access for branch pulmonary artery dilation, all of which results in pulmonary artery growth, simplifying surgical management.

Abnormalities, Multiple↗
PubMed1996

Higher hematocrit improves cerebral outcome after deep hypothermic circulatory arrest.

BACKGROUND: Various degrees of hemodilution are currently in clinical use during deep hypothermic circulatory arrest to counteract deleterious rheologic effects linked with brain injury by previous reports. MATERIAL AND METHODS: Seventeen piglets were randomly assigned to three groups. Group I piglets (n = 7) received colloid and crystalloid prime (hematocrit < 10%), group II piglets (n = 5) received blood and crystalloid prime (hematocrit 20%), group III piglets (n = 5) received blood prime (hematocrit 30%). All groups underwent 60 minutes of deep hypothermic circulatory arrest at 15 degrees C with continuous magnetic resonance spectroscopy and near-infrared spectroscopy Neurologic recovery was evaluated for 4 days (neurologic deficit score 0, normal, to 500, brain death; overall performance category 1, normal, to 5, brain death). Neurohistologic score (0, normal, to 5+, necrosis) was assessed after the animals were euthanized on day 4. RESULTS: Group I had significant loss of phosphocreatine and intracellular acidosis during early cooling (phosphocreatine in group I, 86.3% +/- 26.8%; group II, 117.3% +/- 8.6%; group III, 110.9% +/- 2.68%; p = 0.0008; intracellular pH in group I, 6.95 +/- 0.18; group II, 7.28 +/- 0.04; group III, 7.49 +/- 0.04; p = 0.0048). Final recovery was the same for all groups. Cytochrome aa3 was more reduced in group I during deep hypothermic circulatory arrest than in either of the other groups (group I, -43.6 +/- 2.6; group II, -16.0 +/- 5.2; group III, 1.3 +/= 3.1; p < 0.0001). Neurologic deficit score was best preserved in group III (p < 0.05 group II vs group III) on the first postoperative day, although this difference diminished with time and all animals were neurologically normal after 4 days. Histologic assessment was worst among group I in neocortex area (group I, 1.33 +/- 0.3; group II, 0.22 +/- 0.1; group III, 0.40 +/- 0.2, p < 0.05, group I vs group II; p = 0.0287, group I vs group III). CONCLUSION: Extreme hemodilution during cardiopulmonary bypass may cause inadequate oxygen delivery during early cooling. The higher hematocrit with a blood prime is associated with improved cerebral recovery after deep hypothermic circulatory arrest.

Adenosine Triphosphate↗
PubMed1996

Cerebral metabolic recovery from deep hypothermic circulatory arrest after treatment with arginine and nitro-arginine methyl ester.

BACKGROUND: Recent studies suggest that nitric oxide is important in the pathogenesis of ischemic brain injury and also has a role in controlling cerebrovascular tone. This study examines the net effects of nitric oxide on cerebral metabolic recovery after deep hypothermic circulatory arrest. METHODS: Two-week-old piglets were supported by cardiopulmonary bypass and cooled to 15 degrees C followed by 1 hour of deep hypothermic circulatory arrest, 45 minutes of reperfusion and rewarming, and then 3 hours of normothermic perfusion. Groups of 10 piglets received one of four treatments before bypass; L-nitro-arginine methyl ester, inhibitor of nitric oxide synthesis, 10 mg/kg intravenously; L-arginine, to enhance nitric oxide synthesis, 30 mg/kg intravenously before bypass and then 10 mg/kg per minute during the first hour of reperfusion; a combination of L-nitro-arginine methyl ester plus L-arginine at these same doses; and no pretreatment (controls). Cerebral high-energy phosphates and pH were measured by magnetic resonance spectroscopy in half the animals. Cerebral blood flow, metabolic rates for oxygen and glucose, and the oxidation/reduction state of cytochrome aa3 and oxygenated and deoxygenated hemoglobin measured by near-infrared spectroscopy were assessed in the other half of the piglets. RESULTS: L-nitro-arginine methyl ester significantly increased cerebral vascular resistance and markedly reduced recovery of high-energy phosphates, pH, and oxidation state of cytochrome aa3, L-arginine increased cerebral blood flow, cerebral glucose and oxygen consumption, and recovery of cytochrome aa3 oxidation and high-energy phosphates. L-Arginine did not reverse completely the effects of L-nitro-arginine methyl ester on cerebral metabolic recovery. CONCLUSION: In a piglet model of deep hypothermic circulatory arrest, L-nitro-arginine methyl ester has a deleterious effect and L-arginine has a beneficial effect on cerebral metabolic recovery. The deleterious metabolic effects of L-nitro-arginine methyl ester are only partially reversed by L-arginine. This fact suggests that there may be mechanisms in addition to inhibition of nitric oxide synthesis contributing to the neurotoxicity of L-nitro-arginine methyl ester in this model.

Animals↗
PubMed1996

Conversion of modified Fontan procedure to lateral atrial tunnel cavopulmonary anastomosis.

After modified Fontan procedures with atriopulmonary anastomoses or right atrium-right ventricle conduits, some patients have progressive exercise intolerance, effusions, arrhythmias, or protein-losing enteropathy. Theoretic advantages of a lateral atrial tunnel cavopulmonary anastomosis and published clinical results suggest that conversion of other Fontan procedures to the lateral atrial tunnel may afford clinical improvement for some patients. Eight patients (8 to 25 years old) with tricuspid atresia (n =4), double-inlet left ventricle (n = 3), and double-outlet right ventricle (n=1) underwent conversion to a lateral tunnel procedure between December 1990 and November 1994. An arbitrary clinical score was assigned before the lateral tunnel procedure and at follow-up. Before conversion, patients had decreased exercise tolerance (n = 8), arrhythmias (n = 6), effusions (n = 4), and protein-losing enteropathy (n = 8). At catheterization, all had a low cardiac index (1.9 +/- 0.7 L x min(-1) x M(-2), five had elevated pulmonary vascular resistance (>3 Wood units), and three had right pulmonary venous return obstruction by compression of an enlarged right atrium. Fenestrated lateral tunnel construction was undertaken 7.3 +/- 3.6 years after atriopulmonary anastomosis, with one early death related to low cardiac output. After the lateral tunnel procedure, two patients had no clinical improvement (no change in clinical score) but five patients had either marked or partial improvement. The right pulmonary vein compression present in three patients was resolved after conversion. The mean clinical scores improved from 4.5 +/- 1 to 3.0 +/- 2 (p < 0.04). In conclusion, conversion to a lateral tunnel procedure led to clinical improvement in five of eight patients at short-term follow-up and may be particularly indicated for patients with giant right atria or pulmonary vein compression who have symptoms. Pulmonary vein compression should be looked for in patients after modified Fontan procedures and can be relieved by conversion to the lateral tunnel procedure.

Adolescent↗
PubMed1996

Hypothermia, circulatory arrest, and the pediatric brain.

A review has been conducted of ongoing clinical and laboratory studies of hypothermic circulatory arrest (HCA) and low-flow cardiopulmonary bypass (LFB) at a children's hospital in Boston. A prospective randomized clinical trial of HCA versus LFB has shown a higher incidence of perioperative seizures in patients randomized to HCA. At 1 year of age, neurologic and developmental studies have shown an association between seizures and worse outcome. Longer duration of HCA is associated with a worse score on the Bayley scale assessment of gross and fine motor function in particular, as well as a higher probability of neurologic abnormality. A retrospective review of development after HCA for Senning procedure has shown a correlation between more alkaline pH (alpha-stat strategy) during cooling before HCA and lower developmental score relative to a more acidotic strategy (pH stat). The institutional change to alpha-stat was accompanied by several cases of choreoathetosis after HCA. Currently, patients are being randomized between alpha-stat and pH-stat. Laboratory studies have used a piglet model with assessment of cerebral blood flow and metabolism as well as high-energy phosphates and cerebral pH determined by magnetic resonance spectroscopy. High-energy phosphates are maintained by a flow rate of 50 mL/kg/min but are undetectable after approximately 35 minutes of HCS. A pH-stat is associated with more rapid recovery of high-energy phosphates after HCA than alpha-stat. Recent studies have examined the role of nitric oxide in the causation of brain injury after HCA as well as the potential utility of cerebroplegia in increasing the safe duration of circulatory arrest.

Brain↗
PubMed1996

Tracheal extubation of children in the operating room after atrial septal defect repair as part of a clinical practice guideline.

Early tracheal extubation in the operating room after atrial septal defect (ASD) surgery was recommended as part of a clinical practice guideline (CPG) established in the Cardiovascular Program at the Children's Hospital, Boston, MA. This retrospective review was undertaken to determine whether this practice was efficient without compromising patient care. The charts and hospital charges for 102 patients undergoing secundum ASD or sinus venosus defect surgery between March 1992 and July 1994 were reviewed; 36 patients (Group I) had surgery prior to introduction of the CPG, and 66 patients were managed according to the CPG. Of the latter, 25 patients (Group II) were tracheally extubated in the operating room (OR) and 41 patients (Group III) were extubated in the cardiac intensive care unit (CICU). Patients in all three groups were similar with respect to height, weight, and surgical conditions including cardiopulmonary bypass time, lowest esophageal temperature, hematocrit, total OR time, and the time from completion of bypass to leaving the OR. Patients in Group II received significantly less fentanyl during anesthesia, were more likely to have a respiratory acidosis on admission to the CICU, and had an increased frequency of vomiting in the CICU. There was no difference in duration of CICU stay among groups. The length of hospital stay was reduced in Groups II and III after introduction of the CPGs, but was not influenced by tracheal extubation in the OR. There was no difference among groups in the hospital charges for OR, anesthesia and CICU time. However, when the combined hospital charges for services provided both in the OR and CICU were included, patients in Group II were charged significantly less, and this primarily reflects the absence of postoperative mechanical ventilation charges. Tracheal extubation in the OR after ASD surgery in children can result in lower patient charges without significantly compromising patient care.

Acidosis, Respiratory↗
PubMed1995

Sternotomy approach for the modified Blalock-Taussig shunt.

BACKGROUND: Since 1990, sternotomy has been the preferred approach for construction of a modified Blalock-Taussig shunt (MBTS) at Children's Hospital, Boston, Mass. In retrospect, we sought to test the hypothesis that this approach yields less mortality and morbidity than the traditional thoracotomy approach. METHODS AND RESULTS: One hundred four primary MBTSs with polytetrafluoroethylene grafts were constructed in patients from January 1988 through December 1992. Fifty-two shunts were constructed by thoracotomy approach and 52 by sternotomy approach. Fifteen of the thoracotomy patients were less than one month of age (8 less than 7 days), while 36 of the sternotomy patients were less than 1 month of age (20 less than 7 days). There were 10 shunt failures and 3 hospital deaths in the thoracotomy group and 4 shunt failures with 6 hospital deaths in the sternotomy group. The overall hospital mortality rate for the group was 8.7% (9 of 104). The operative route was not a significant predictor of hospital mortality (P = .30). However, there was a significant difference between the two operative approaches in shunt failure, with shunts that were created by thoracotomy four times more likely to fail than those created by the sternotomy route (odds ratio, OR, 3.88; 95% CI, 1.01 to 15.03; P = .049). The side of the shunt was also a significant predictor of failure with left-side MBTSs foru times more prone to failure (OR, 4.02; 95% CI, 1.19 to 15.25; P = .025). CONCLUSIONS: The sternotomy route is technically less challenging and is associated with fewer shunt failures than the classic thoracotomy approach. The potential theoretical disadvantages of this method for future sternal reentry for subsequent procedures was not apparent but requires prospective analysis.

Adolescent↗
PubMed1995

Ten-year institutional experience with palliative surgery for hypoplastic left heart syndrome. Risk factors related to stage I mortality.

BACKGROUND: We reviewed 212 consecutive patients who underwent stage I palliative surgery for hypoplastic left heart syndrome (HLHS) at our institution between January 1983 and June 1993. METHODS AND RESULTS: Six surgeons participated in the care of these patients. Follow-up is 97% complete. Preoperative anatomic and physiological factors and procedural features of the stage I operation were analyzed for impact on stage I mortality, survival to stage II palliation, and actuarial survival. Hospital mortality was not significantly lower during the second half of the study period (P = .242). Operative mortality was 46.2%. Multivariate analysis revealed improved stage I operative survival in patients with mitral stenosis (MS) and aortic stenosis (AS; P = .006). Additional risk factors for stage I mortality were a lower immediately pre-stage I pH (P = .034) and weight < 3 kg (P = .015). Overall first-year actuarial survival for MS/AS was 59%, and it was 33% for all others (P = .001). Among stage I survivors, patients with MS/AS were more likely to survive to stage II palliation (P = .031). Analysis of actuarial survival of stage I survivors showed that a smaller ascending aorta (P < .001), aortic atresia (P < .001), and mitral atresia (P = .002) were all risk factors for intermediate death. CONCLUSIONS: Preoperative anatomic and physiological state are predictors of stage I mortality. HLHS anatomic subtype also influences intermediate outcome, most notably pre-stage II attrition. These data may be useful in choosing initial management for patients with HLHS.

Analysis of Variance↗
PubMed1995

Postoperative course and hemodynamic profile after the arterial switch operation in neonates and infants. A comparison of low-flow cardiopulmonary bypass and circulatory arrest.

BACKGROUND: The neurological morbidity associated with prolonged periods of circulatory arrest has led some cardiac surgical teams to promote continuous low-flow cardiopulmonary bypass as an alternative strategy. The nonneurological postoperative effects of both techniques have been previously studied only in a limited fashion. METHODS AND RESULTS: We compared the hemodynamic profile (cardiac index and systemic and pulmonary vascular resistances), intraoperative and postoperative fluid balance, and perioperative course after deep hypothermia and support consisting predominantly of total circulatory arrest or low-flow cardiopulmonary bypass in a randomized, single-center trial. Eligibility criteria included a diagnosis of transposition of the great arteries and a planned arterial switch operation before the age of 3 months. Of the 171 patients, 129 (66 assigned to circulatory arrest and 63 to low-flow bypass) had an intact ventricular septum and 42 (21 assigned to circulatory arrest and 21 to low-flow bypass) had an associated ventricular septal defect. There were 3 (1.8%) hospital deaths. Patients assigned to low-flow bypass had significantly greater weight gain and positive fluid balance compared with patients assigned to circulatory arrest. Despite the increased weight gain in the infants assigned to low-flow bypass, the duration of mechanical ventilation, stay in the intensive care unit, and hospital stay were similar in both groups. Hemodynamic measurements were made in 122 patients. During the first postoperative night, the cardiac index decreased (32.1 +/- 15.4%, mean +/- SD), while pulmonary and systemic vascular resistance increased. The measured cardiac index was < 2.0 L.min-1.m-2 in 23.8% of the patients, with the lowest measurement typically occurring 9 to 12 hours after surgery. Perfusion strategy assignment was not associated with postoperative hemodynamics or other nonneurological postoperative events. CONCLUSIONS: After heart surgery in neonates and infants, both low-flow bypass and circulatory arrest perfusion strategies have comparable effects on the nonneurological postoperative course and hemodynamic profile.

Cardiopulmonary Bypass↗
PubMed1995

Video-assisted thoracoscopic vascular ring division in infants and children.

OBJECTIVES: This study evaluated our early experience with video-assisted thoracoscopic vascular ring division and compared this approach with division by means of a conventional open thoracotomy. BACKGROUND: Video-assisted thoracoscopic techniques reduce surgical trauma and have been applied to several adult thoracic procedures; however, pediatric applications have been limited. We developed instruments and techniques for video-assisted thoracoscopic vascular ring division in the pediatric population. METHODS: We compared patient characteristics, operative results and postoperative hospital courses of all patients undergoing vascular ring division by a video-assisted approach with a historical control group of all patients undergoing division by an open thoracotomy between January 1991 and December 1992. RESULTS: Eight patients (median age 5 months, range 40 days to 5.5 years; median weight 6.2 kg, range 1.8 to 17.1) underwent video-assisted thoracoscopic vascular ring division. Four had a double aortic arch with an atretic left arch and a left ligamentum, and four had a right aortic arch with aberrant left subclavian artery and a left ligamentum. All eight had successful ring division with symptomatic relief and no mortality. A limited thoracotomy was performed in three patients to divide patent vascular structures, and the hospital period was prolonged in one because of chylothorax. These eight patients were compared with a historical cohort of eight pediatric patients having vascular ring division performed by a conventional thoracotomy. The two groups did not differ in age, weight, intensive care unit or postoperative hospital stay, duration of intubation or thoracostomy tube or hospital charges. Total operating room time was longer for the group undergoing video-assisted operation. CONCLUSIONS: Early results for video-assisted thoracoscopic vascular ring division are comparable to those of the conventional surgical approach. With further refinement in technique and instrumentation, video-assisted surgical intervention may become a viable alternative to open thoracotomy for management of the symptomatic vascular ring.

Aorta, Thoracic↗
PubMed1995

Developmental and neurologic status of children after heart surgery with hypothermic circulatory arrest or low-flow cardiopulmonary bypass.

BACKGROUND: Deep hypothermia with either total circulatory arrest or low-flow cardiopulmonary bypass is used to support vital organs during heart surgery in infants. We compared the developmental and neurologic sequelae of these two strategies one year after surgery. METHODS: Infants with D-transposition of the great arteries who underwent an arterial-switch operation were randomly assigned to a method of support consisting predominantly of circulatory arrest or a method consisting predominantly of low-flow bypass. Developmental and neurologic evaluations and magnetic resonance imaging (MRI) were performed at one year of age. RESULTS: Of the 171 patients enrolled in the study, 155 were evaluated. After adjustment for the presence or absence of a ventricular septal defect, the infants assigned to circulatory arrest, as compared with those assigned to low-flow bypass, had a lower mean score on the Psychomotor Development Index of the Bayley Scales of Infant Development (a 6.5-point deficit, P = 0.01) and a higher proportion had scores < or = 80 (i.e., 2 SD or more below the population mean) (27 percent vs. 12 percent, P = 0.02). The score on the Psychomotor Development Index was inversely related to the duration of circulatory arrest (P = 0.02). The risk of neurologic abnormalities increased with the duration of circulatory arrest (P = 0.04). The method of support was not associated with the prevalence of abnormalities on MRI scans of the brain, scores on the Mental Development Index of the Bayley Scale, or scores on a test of visual-recognition memory. Perioperative electroencephalographic seizure activity was associated with lower scores on the Psychomotor Development Index (P = 0.002) and an increased likelihood of abnormalities on MRI scans of the brain (P < 0.001). CONCLUSIONS: Heart surgery performed with circulatory arrest as the predominant support strategy is associated with a higher risk of delayed motor development and neurologic abnormalities at the age of one year than is surgery with low-flow bypass as the predominant support strategy.

Brain↗
PubMed1995

Cerebral oxygen supply and utilization during infant cardiac surgery.

The survival of infants with congenital heart disease has improved dramatically. However, the incidence of neurological injury in infants surviving cardiac surgery remains considerable. These neurological sequelae are attributable at least in part to hypoxia-ischemia/reperfusion, which inevitably accompanies infant heart surgery with deep hypothermia, cardiopulmonary bypass, and circulatory arrest. To begin to identify mechanisms of brain injury during infant cardiac surgery, we used near-infrared spectroscopy to study the relationship between cerebral intravascular (hemoglobin) and mitochondrial (cytochrome aa3) oxygenation in 63 infants (aged 1 day to 9 months) undergoing deep hypothermic repair of congenital heart defects, throughout the intraoperative period. Moreover, we assessed the effect of postnatal age on these changes. The cerebral concentration of oxidized cytochrome aa3 decreased from the onset of deep hypothermic cardiopulmonary bypass, despite apparent abundant intravascular oxygenation manifested by a simultaneous increase in the cerebral concentration of oxyhemoglobin. During this interval infants older than 2 weeks had a greater decrease in oxidized cytochrome aa3 than did infants 2 weeks old or younger. During deep hypothermic circulatory arrest, cerebral levels of oxidized cytochrome aa3 remained depressed while those of oxyhemoglobin declined. With reperfusion following circulatory arrest, the recovery of oxidized cytochrome aa3 was delayed, despite a rapid recovery of intravascular oxygenation (HbO2). After rewarming and 60 minutes of reperfusion, only 46% of infants recovered to the baseline level of cerebral oxidized cytochrome aa3. These findings demonstrate a paradoxical dissociation of changes in intravascular and mitochondrial oxygenation during hypothermic cardiopulmonary bypass; a pronounced decrease of mitochondrial oxygenation is established during induction of hypothermia and a delay in recovery of mitochondrial oxygenation occurs following circulatory arrest. These effects were more pronounced in infants older than 2 weeks than in younger infants. The data suggest potentially deleterious impairments of intrinsic mitochondrial function or of delivery of intravascular oxygen to the mitochondrion or both, effects previously undetected and apparently influenced by cerebral maturation.

Brain↗
PubMed1995

Tetralogy of Fallot [S,D,I]: successful repair without a conduit.

Tetralogy of Fallot [S,D,I] is a recently discovered form of tetralogy with solitus atria (S) and D-loop ventricles (D), but with inverted normally related great arteries (I). Because of infundibuloarterial inversion, the right coronary artery must traverse the stenotic pulmonary outflow tract, increasing the risk of surgical trauma to the right coronary artery. Here we report a case of successful surgical repair of tetralogy of Fallot [S,D,I] without the use of an extracardiac conduit.

Cardiac Surgical Procedures↗