Home surveillance program prevents interstage mortality after the Norwood procedure.

OBJECTIVE: To determine whether early identification of physiologic variances associated with interstage death would reduce mortality, we developed a home surveillance program. METHODS: Patients discharged before initiation of home surveillance (group A, n = 63) were compared with patients discharged with an infant scale and pulse oximeter (group B, n = 24). Parents maintained a daily log of weight and arterial oxygen saturation according to pulse oximetry and were instructed to contact their physician in case of an arterial oxygen saturation less than 70% according to pulse oximetry, an acute weight loss of more than 30 g in 24 hours, or failure to gain at least 20 g during a 3-day period. RESULTS: Interstage mortality among infants surviving to discharge was 15.8% (n = 9/57) in group A and 0% (n = 0/24) in group B (P =.039). Surveillance criteria were breached for 13 of 24 group B patients: 12 patients with decreased arterial oxygen saturation according to pulse oximetry with or without poor weight gain and 1 patient with poor weight gain alone. These 13 patients underwent bidirectional superior cavopulmonary connection (stage 2 palliation) at an earlier age, 3.7 +/- 1.1 months of age versus 5.2 +/- 2.0 months for patients with an uncomplicated interstage course (P =.028). A growth curve was generated and showed reduced growth velocity between 4 and 5 months of age, with a plateau in growth beyond 5 months of age. CONCLUSION: Daily home surveillance of arterial oxygen saturation according to pulse oximetry and weight selected patients at increased risk of interstage death, permitting timely intervention, primarily with early stage 2 palliation, and was associated with improved interstage survival. Diminished growth identified 4 to 5 months after the Norwood procedure brings into question the value of delaying stage 2 palliation beyond 5 months of age.

Factors related to pleural effusions after Fontan procedure in the era of fenestration.

BACKGROUND: Significant pleural effusions after the Fontan operation prolong hospital stay, may increase the risk of infection, and may necessitate a pleurodesis procedure. METHODS AND RESULTS: From February 1991 to April 2000, 98 consecutive patients under the age of 18 years underwent the fenestrated Fontan procedure at Children's Hospital of Wisconsin. Ninety-four patients who survived at least 30 days after surgery were retrospectively evaluated for the following factors: age, ventricular morphology (right single ventricle, left single ventricle [RV/LV]), fenestration open (FO) or closed (FC) at end of operation, intracardiac Fontan (IF) or extracardiac Fontan (EF), days with chest tube output per day >5, 10, and/or 20 mL. kg(-1). d(-1) (CTO5, CTO10, and CTO20, respectively), need for pleurodesis, length of hospital stay (LOS), operation during winter respiratory viral season of November through March (ReVS+, ReVS-), and pre-Fontan mean pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR). In univariate analysis, the ReVS+ patients had prolonged LOS, greater chest tube output, and more pleurodesis (P<0.05), and PAP was related to CTO5 and CTO10 but not to CTO20 or LOS. No significant differences were found in LOS, CTO5, CTO10, CTO20, and need for pleurodesis between patients in RV/LV, FO/FC, IF/EF, or PVR groups. Patients <4 years of age had more instances of CTO20 (P<0.05). When we used ordinary least squares regression analysis with age, FO or FC, RV or LV, PAP, and ReVS+ or ReVS- to predict each of CTO5, CTO10, CTO20, and LOS, only ReVS+ or ReVS- and age were statistically significant in all models. CONCLUSIONS: Use of the Fontan procedure during the respiratory viral season appeared to be related to significant, prolonged pleural effusions and longer hospitalizations.

Venous saturation and the anaerobic threshold in neonates after the Norwood procedure for hypoplastic left heart syndrome.

BACKGROUND: Reduction in oxygen delivery can lead to organ dysfunction and death by cellular hypoxia, detectable by progressive (mixed) venous oxyhemoglobin desaturation until extraction is limited at the anaerobic threshold. We sought to determine the critical level of venous oxygen saturation to maintain aerobic metabolism in neonates after the Norwood procedure (NP) for the hypoplastic left heart syndrome (HLHS). METHODS: A prospective perioperative database was maintained for demographic, hemodynamic, and laboratory data. Invasive arterial and atrial pressures, arterial saturation, oximetric superior vena cava (SVC) saturation, and end-tidal CO2 were continuously recorded and logged hourly for the first 48 postoperative hours. Arterial and venous blood gases and cooximetry were obtained at clinically appropriate intervals. SVC saturation was used as an approximation of mixed venous saturation (SvO2). A standard base excess (BE) less than -4 mEq/L (BElo), or a change exceeding -2 mEq/L/h (deltaBElo), were used as indicators of anaerobic metabolism. The relationship between SvO2 and BE was tested by analysis of variance and covariance for repeated measures; the binomial risk of BElo or deltaBElo at SvO2 strata was tested by the likelihood ratio test and logistic regression, with cutoff at p < 0.05. RESULTS: Complete data were available in 48 of 51 consecutive patients undergoing NP yielding 2,074 valid separate determinations. BE was strongly related to SvO2 (model R2 = 0.40, p < 0.0001) with minimal change after adjustment for physiologic covariates. The risk of anaerobic metabolism was 4.8% overall, but rose to 29% when SvO2 was 30% or below (p < 0.0001). Survival was 100% at 1 week and 94% at hospital discharge. CONCLUSIONS: Analysis of acid-base changes revealed an apparent anaerobic threshold when SvO2 fell below 30%. Clinical management to maintain SvO2 above this threshold yielded low mortality.

Factors affecting longevity of homograft valves used in right ventricular outflow tract reconstruction for congenital heart disease.

BACKGROUND: Few studies have explored the long-term function of cryopreserved homograft valves used for reconstruction of the right ventricular tract (RVOT) in patients with congenital heart disease. METHODS AND RESULTS: Among 205 patients receiving cryopreserved homografts for reconstruction of the RVOT between November 1985 and April 1999, the outcome of 220 homografts in 183 operative survivors was analyzed. There were 150 pulmonary and 70 aortic homografts used. Median age at implantation was 4.4 years (mean 6.9+/-7.6 years, range 3 days to 48 years). End points included (1) patient survival, (2) homograft failure (valve explant or late death), and (3) homograft dysfunction (homograft insufficiency or homograft stenosis). Survival was 88% at 10 years. Freedom from homograft failure was 74+/-4% at 5 years and 54+/-7% at 10 years. Univariable analysis identified younger age, longer donor warm ischemic time, valve Z: value <2, and previous procedure as risk factors for homograft failure and dysfunction. Aortic homograft type and extracardiac operative technique predicted homograft failure but not dysfunction. For patients

Patients at risk for low systemic oxygen delivery after the Norwood procedure.

BACKGROUND: Identification of patients at risk for inadequate systemic oxygen delivery following the Norwood procedure could allow for application of more intensive monitoring, provide for earlier intervention of decreased cardiac output, and result in improved outcome. METHODS AND RESULTS: Superior vena cava saturation (SvO2) and arteriovenous oxygen content difference were prospectively monitored as indicators of systemic oxygen delivery and recorded hourly for the first 48 hours in 29 of 33 consecutive patients following the Norwood procedure. Risk factors were evaluated using multiple linear regression to determine their impact on SvO2 and arteriovenous oxygen content difference. Age less than 8 days, weight less than 2.5 kg, aortic atresia, and prolonged cardiopulmonary bypass time were risk factors for low SvO2 and wide arteriovenous oxygen content difference (p < 0.05). Phenoxybenzamine and increasing time after operation were associated with higher SvO2 and narrower arteriovenous oxygen content difference (p < 0.05). Thirty-day survival was 97% and hospital survival was 94%. The earliest death occurred on postoperative day 20. Survival to bidirectional cavopulmonary shunt was 77%. Preoperative mechanical ventilation was the only risk factor identified for late death. CONCLUSIONS: Aortic atresia, low weight, younger age, and prolonged cardiopulmonary bypass, previously identified risk factors for mortality, were associated with decreased SvO2 and narrower arteriovenous oxygen content difference in the early postoperative period. The impact of this hemodynamic vulnerability on mortality was minimized by continuous SvO2 monitoring.

Recent advances in the surgical management of the single ventricle pediatric patient.

A standardized approach to the patient with single ventricle anatomy (SVA) is presented in this article. Regardless of the specific anatomic subtype, patients with SVA share common risk factors for early and late mortality and morbidity. Management of the SVA patients requires a plan to avoid development of these risk factors. Neonatal palliation is directed at relieving any systemic obstruction and appropriate limitation of pulmonary blood flow. The application of a standardized approach to the neonate with SVA, followed by staged palliation to a completion Fontan procedure should result in improved early and late outcome.

Phenoxybenzamine improves systemic oxygen delivery after the Norwood procedure.

BACKGROUND: Achieving adequate systemic oxygen delivery after the Norwood procedure frequently is complicated by excessive pulmonary blood flow at the expense of systemic blood. We hypothesized that phenoxybenzamine could achieve a balanced circulation through reduction of systemic vascular resistance. METHODS: In this prospective, nonrandomized study, oximetric catheters were placed in the superior vena cava for continuous monitoring of systemic venous oxygen saturation. Postoperative hemodynamic variables were compared between 7 control patients and 8 patients who received phenoxybenzamine. RESULTS: The hospital survival rate was 93% (14 of 15 patients). Improvements in postoperative hemodynamics in the phenoxybenzamine group included a higher systemic venous oxygen saturation, a narrower arteriovenous oxygen content difference, a lower ratio of pulmonary to systemic flow, and a lower indexed systemic vascular resistance. In the phenoxybenzamine group, mean arterial blood pressure was related directly to systemic oxygen delivery, in contrast to the control group, where mean arterial pressure was related directly to indexed systemic vascular resistance and the ratio of pulmonary to systemic circulation. CONCLUSIONS: Continuous postoperative monitoring of systemic venous oxygen saturation in a patient who has undergone the Norwood procedure provides early identification of low systemic oxygen delivery and an elevated ratio of pulmonary to systemic circulation. In this pilot study, phenoxybenzamine appeared to improve systemic oxygen delivery during the early postoperative period after the Norwood procedure. Further studies are indicated to confirm these results.

Advances in the care of children with heart disease.

As we enter the next millennium, we are encouraged by the progress that has been made in the care of neonates, infants, and children with heart disease. Surgical repair can be offered at an earlier age with excellent results. Diseases that were uniformly fatal in the past have improved outcomes. Research continues in the area of interventional devices such that surgical repair might be eliminated or delayed. We continue to look forward to advances in the next several years that will allow for future improvement in outcome, better quality-of-life and better long-term results.

Aprotinin improves outcome of single-ventricle palliation.

BACKGROUND: Elevation of pulmonary vascular resistance as a consequence of cardiopulmonary bypass may lead to failure of single-ventricle palliation. We reviewed our experience with aprotinin, a nonspecific serine protease inhibitor, to determine whether it could ameliorate the inflammatory effects of cardiopulmonary bypass and improve outcome of single-ventricle palliation. METHODS: Forty-six consecutive patients undergoing single-ventricle palliation using cardiopulmonary bypass were reviewed retrospectively. Aprotinin was used in 8 of 30 bidirectional cavopulmonary shunt and 10 of 16 Fontan procedures. RESULTS: Aprotinin use was associated with a decrease in the early postoperative transpulmonary gradient among patients undergoing Fontan and bidirectional cavopulmonary shunt procedures. The bidirectional cavopulmonary shunt aprotinin group had a higher oxygen saturation and a decrease in quantity and duration of thoracic drainage. Among patients receiving aprotinin there were no episodes of mediastinitis, thrombus formation, or renal failure. CONCLUSIONS: Aprotinin use in single-ventricle palliation was associated with decreased transpulmonary gradient and increased oxygen saturation consistent with decreased pulmonary vascular resistance. This retrospective study suggests that aprotinin has a favorable impact on the early postoperative course of single-ventricle palliation.

Twenty-year experience with repair of complete atrioventricular septal defects.

BACKGROUND: To determine factors predicting mortality and morbidity after repair of complete atrioventricular septal defect, we retrospectively analyzed preoperative, operative, and postrepair factors on the outcome of 115 consecutive complete atrioventricular septal defect repairs at The Children's Hospital of Wisconsin between January 1974 and December 1993. METHODS: For the entire experience the operative mortality was 13.9% (16 patients). During the most recent era, January 1988 to December 1993, operative mortality was 3.6% (2 of 55 patients). This was significantly improved from the two previous eras, January 1974 to December 1980, 28% (7 of 25) and January 1981 to December 1987, 20% (7 of 35 patients) (p = 0.02). There were seven late deaths; 10-year actuarial survival, including operative mortality was 81%. Age at complete repair decreased; before 1982 all patients were more than 12 months of age, whereas after 1982 64% (56 of 88 patients) were 12 months of age or less. RESULTS: Moderate or severe preoperative left atrioventricular valve regurgitation was not a risk factor for operative mortality. For operative survivors with moderate to severe preoperative left atrioventricular valve regurgitation (n = 17), late postoperative left atrioventricular valve regurgitation (follow-up data available on 15 patients) was significantly reduced (severe = 1, moderate = 5, mild = 9; p = 0.007). CONCLUSIONS: Early mortality was predicted by the era of surgical repair. Conversion to routine repair during infancy was achieved with a simultaneous decrease in operative mortality. For patients with moderate to severe preoperative left atrioventricular valve regurgitation, significant improvement in the degree of left atrioventricular valve regurgitation can be expected without an increase in operative or late mortality or morbidity.

Does an additional source of pulmonary blood flow alter outcome after a bidirectional cavopulmonary shunt?

BACKGROUND: The bidirectional cavopulmonary shunt has become an important intermediate step in the treatment of pediatric patients with single ventricle physiology who are ultimately destined for palliative surgery. We wanted to know whether there would be risks or benefits if an additional source of pulmonary blood flow was left after a bidirectional cavopulmonary shunt. METHODS AND RESULTS: We retrospectively reviewed the medical and surgical records of all patients who underwent a bidirectional cavopulmonary shunt at the Children's Hospital of Wisconsin between January 1991 and December 1993. A total of 43 patients were identified. Anatomic diagnoses included double inlet left ventricle (14 patients), tricuspid atresia (8 patients), pulmonary atresia with intact septum (6 patients), single right ventricle (5 patients), hypoplastic left heart (3 patients), unbalanced atrioventricular septal defect (3 patients), and other complex lesions (4 patients). We then divided the patients into two groups for purposes of analysis. Group 1 had only the cavopulmonary shunt as a source of pulmonary flow (22 patients); group 2 had an additional source of pulmonary flow (21 patients). Patient age at the time of cavopulmonary shunt ranged from 6 months to 12 years, with group 1 patients being younger (31 versus 45 months, P = .05). Group 2 patients had higher postoperative central venous pressures (17.8 versus 14.1 mm Hg, P < .001) and oxygen saturations (86% versus 81%, P < .001) than did group 1 patients. There was no statistical difference between groups in the number of chest tube days or hospital days. There was 1 early death in group 1 related to severe ventricular dysfunction and 1 late death in group 2 related to sepsis. Five patients in group 2 were readmitted to the hospital for drainage of a large chylothorax compared with none in group 1 (P < .02). CONCLUSIONS: We conclude that patients with an additional source of pulmonary blood flow after bidirectional cavopulmonary shunt have higher postoperative central venous pressures, have higher oxygen saturations, and are at risk for the late development of a chylothorax.

Results of Mustard's repair for dextro-transposition of the great arteries.

Dextro-Transposition of Great Arteries (d-TGA) was repaired by Mustard's operation in 69 patients during a 10 year period (1973-1982) in our institution. Ages at the time of surgery ranged from 3 months to 18 years, with a median age of 18 months. Factors that most affected mortality and morbidity were associated cardiac defect, the year of the operation and the age of the patient. Of the 69 patients, 26 (38%) had complex d-TGA. Early post-operative mortality was 2.38% for patients with simple transposition and 22% for the complex group. All early deaths occurred in the early part of series. Ten consecutive cases with complex transpositions in the late part of the series have done well. There were 5 late deaths--4 from the early series and these had complex transposition. Postoperative non-fatal complications included arrhythmia which occurred in 6 patients (9%). The rhythm abnormality was temporary in 2 and permanent pacing was required in 2 other patients (2.9%). There were 3 cases of late caval obstruction and 4 cases of late pulmonary venous obstruction--six of these seven patients were less then 12 months of age. Postoperative renal failure occurred in patients in the early series but was not seen in the late series. Three children developed postoperative pulmonary edema due to large bronchial collateral arteries and underwent successful collateral vessel ligation subsequent to the Mustard operation. Two patients have demonstrated late tricuspid regurgitation, are presently in heart failure and may need valve replacement.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypoxemia and pulmonary hyperperfusion due to systemic collateral arteries after total repair of transposition of the great arteries.

Two cases of hypoxemia and pulmonary hyperperfusion due to large bronchial collateral arteries after total repair of simple transposition of the great arteries (TGA) are presented. Pulmonary hyperperfusion was not present before total repair. Hypoxemia and congestive heart failure quickly abated after surgical ligation of these enlarged bronchial collateral arteries. The patients were totally corrected quite late (at 21 and 22 months respectively) by current standards. It is suggested that: (1) large bronchial collaterals may develop in patients with simple TGA especially if total correction is delayed; (2) preoperative angiographic evaluation of patients with simple TGA who come in for total correction late, should include special aortic root injection to exclude the presence of bronchial collaterals; (3) hypoxemia and pulmonary congestion after total correction of TGA by atrial switch procedure (Mustard or Senning) may in fact be due to bronchial collaterals and not obstruction of the pulmonary veins.

Bilateral semilunar valvotomies using inflow occlusion in a neonate.

The case of a neonate with critical pulmonary and aortic valve stenosis who underwent successful sequential valvotomies using one period of inflow occlusion is reported. This valvotomy technique performed in critically ill neonates, if carried out expeditiously, can result in the same degree of success as when used for single valvotomies.

The Senning procedure for repair of d-transposition of the great arteries.

We report our results with the Senning procedure for repair of d-transposition of the great arteries (d-TGA) including techniques that we feel facilitate the operation. When the atrial septal flap is deficient at the site of an atrial septal defect, the flap is filleted to enlarge it using living tissue. This also has the effect of thinning the septal flap which enlarges the left pulmonary vein pathway located posterior to the floor of the new caval tunnels. Another technique includes the use of the upper end of the sulcus terminalis in the construction of the roof of the new caval tunnels. The upper posterior rim of the right atriotomy is left external to this suture line and can be used in construction of the new pulmonary venous pathway. The latter suture line is inferior to the SA node and can be placed expeditiously and with less chance of damaging the SA node. Use of this technique has resulted in a reduced incidence of late arrhythmias. Following the Senning procedure in 40 patients there were no hospital deaths, but there were two late deaths. The Senning operation is currently a very satisfactory alternative for repair of d-TGA when arterial switch repair cannot be performed.

Radionuclide cardioangiographic demonstration of a coronary artery fistula.

A case demonstrating the radionuclide cardioangiographic appearance of a coronary artery fistula is presented. The correct definitive diagnosis of this disorder has generally been made by angiography since clinical findings and noninvasive diagnostic studies can be nonspecific. We report the diagnosis and shunt quantification of a right coronary artery fistula to the right ventricle by radionuclide cardioangiography.

Effects of chronic right-to-left cardiac shunt on hypoxic sensitivity of mongrel dogs.

Resting ventilation (VI), blood gases, hypoxic sensitivity, and the ventilatory responses to intravenous sodium cyanide (NaCN, 100 micrograms/kg), doxapram (DOX, 500 micrograms/kg), and dopamine (DOPA, 20 micrograms/kg) were analyzed in four normal mongrel dogs (group I-N) and seven mongrel dogs with chronic (5-11 yr) right-to-left cardiac shunt (group II). The group I-N animals were also studied during steady-state isocapnic hypoxia (group I-H). The shunt procedure used for these studies produced a model for ventilatory studies during chronic shunt hypoxemia. The increases in VI per percent decrease in O2 saturation, which occurred during a four-breath N2 test, were 30, 43, and 13 ml X kg-1 X min-1 in groups I-N, I-H, and II, respectively. The decrease in hypoxic sensitivity of the group II animals, compared with groups I-N and I-H, occurred in the presence of an increase in PaCO2 from 21.9 to 26.0 Torr during the four-breath N2 test. A decrease in PaCO2 from 34.7 to 30.0 and from 33.6 to 30.4 Torr was observed in groups I-N and I-H. The response to DOX, a general analeptic agent, was greatest in group II and least in group I-N. However, the ventilatory responses to NaCN and DOPA were not sufficiently different among the three groups to suggest a difference in carotid body function as assessed by these drugs.