Richard D. Mainwaring

Aortopulmonary collateral vessels and prolonged pleural effusions after modified Fontan procedures

Pleural effusions after the modified Fontan procedure are unpredictable, increase morbidity, and prolong hospital stay. To assess the relation between preoperative characteristics and postoperative pleural drainage, we performed a retrospective study of 71 patients who underwent Fontan procedures. Analyses revealed no significant relation between duration of effusion and age at Fontan, preoperative oxygen saturation, pulmonary artery pressure, ventricular end-diastolic pressure, type of Fontan, or prior cavopulmonary anastomosis. Patients with significant aortopulmonary collateral vessels evidenced by angiographic opacification of the pulmonary arteries or veins had more prolonged pleural drainage. The duration of the pleural drainage was significantly less in patients who had aortopulmonary collateral occlusion.

Neurodevelopmental outcomes in children with Fontan repair of functional single ventricle

Objectives.u2003The purpose of this study was to assess the neurodevelopmental status of children after Fontan repair of functional single ventricle and to examine the relationship between cognitive function and selected patient characteristics. Study Design.u2003Neurodevelopmental tests including the Stanford-Binet Intelligence (IQ) scale and the Developmental Test of Visual Motor Integration (VMI) were administered to 32 children (26 months to 16 years of age) with complex single ventricle. The mean and distribution of IQ and VMI scores were compared with population norms. The relationship between test scores and patient characteristics was examined utilizing analysis of variance and correlational methods. Results.u2003The majority of children had intellectual function within the normal range (mean, 97.5 ± 12.1). Below average VMI scores were found in 21.4% of children. There were no significant correlations between intellectual function or visual motor integration ability and preoperative oxygen saturation or age at Fontan. Children who had deep hypothermic circulatory arrest during a prior Norwood procedure tended to have a lower IQ score. Conclusions.u2003Intellectual development in children with Fontan repair of complex heart defects is essentially within the normal range. Visual motor integration deficits may be more prevalent in these children. In our population, the duration and degree of preoperative hypoxemia had no apparent effect on cognitive function.

Bidirectional Glenn: Is accessory pulmonary blood flow good or bad?

BACKGROUNDnThe bidirectional Glenn (BDG) is frequently used in the staged surgical management of single ventricle patients. Controversy exists whether accessory pulmonary blood flow (APBF) sources should be left at the time of the BDG to augment systemic saturation or should be eliminated to reduce volume load of the ventricle. The present study was a retrospective review to assess the influence of APBF on outcome after the BDG.nnnMETHODS AND RESULTSnNinety-two patients have undergone BDG at our institute during the interval from 1986 through 1994. At the time of BDG, 40 patients had either a systemic-to-pulmonary artery shunt or patent right ventricular outflow tract as an additional source of pulmonary blood flow. Fifty-two patients had elimination of APBF. There were three operative deaths (two with and one without APBF) and four procedures (two in each group) that failed and required subsequent revision. Thus, there were 85 patients who underwent successful operation. Effusions (defined as chest tube drainage exceeding 7 days duration) occurred in 8 of 85 patients; this complication was seen in 7 of 36 patients (19%) with APBF and 1 of 49 patients (2%) without APBF (P < .05). There were 11 deaths, including 6 patients (17%) with APBF, 2 patients (4%) without APBF, and 3 of the patients (75%) who had a failed BDG.nnnCONCLUSIONSnThe data suggest that morbidity and mortality are lower in patients in whom APBF is eliminated at the time of the BDG.

Factors influencing perioperative morbidity during palliation of the univentricular heart

BACKGROUNDnThe modified Fontan procedure has become the treatment of choice for patients born with a univentricular heart. Although the operative mortality has steadily decreased in recent years, the hospital stay is still prolonged in many patients due to fluid retention and pleural effusions.nnnMETHODSnWe retrospectively analyzed subsets of patients undergoing the bidirectional cavopulmonary shunt (BDCPS) and modified Fontan procedure in an attempt to define factors influencing operative mortality and morbidity.nnnRESULTSnMultivariate analysis of 64 patients undergoing BDCPS revealed that age 6 months or less, concomitant operation, mean pulmonary pressure of 15 mm Hg or less, and mean pulmonary artery ratio of 1.8:1 or less were not statistically significant indicators of risk. Abnormal pulmonary artery architecture was a significant predictor of early and late death (p < or = 0.01). Retrospective analysis of 71 patients undergoing the modified Fontan procedure revealed no significant relationship between duration of pleural effusions and age at operation, preoperative oxygen saturation, pulmonary artery pressure, ventricular end-diastolic pressure, or prior BDCPS: Patients with important aortopulmonary collateral vessels defined by angiography had prolonged pleural drainage. Selective use of the total extracardiac conduit and the fenestrated Fontan resulted in low overall mortality with no statistical differences between subsets of patients undergoing different modifications of the Fontan procedure.nnnCONCLUSIONSnThese data indicate that the operative risk for BDCPS or modified Fontan procedure is quite low if a procedure appropriate for the patient is selected. Abnormal pulmonary artery architecture is an important risk factor for death after the BDCPS: Aortopulmonary collateral vessels are associated with fluid retention and pleural effusions after a modified Fontan procedure. Important aortopulmonary collateral vessels should be occluded before or during the modified Fontan procedure.

Complement activation and cytokine generation after modified Fontan procedure

BACKGROUNDnThe modified Fontan procedure separates the systemic and pulmonary circulations in patients born with a functional single ventricle. Delayed recovery is frequently observed after this procedure. It was our hypothesis that complement activation or cytokine generation may contribute to the pathophysiology of this problem.nnnMETHODSnWe measured activated complement C3, thromboxane B2, interleukin-6, and tumor necrosis factor-alpha levels by immunoassay in 16 patients undergoing Fontan procedure. Patient plasma samples were obtained preoperatively, on initiation of cardiopulmonary bypass, after administration of protamine, and 1, 4, 8, and 24 hours postoperatively.nnnRESULTSnThere was no early or late mortality in this cohort of patients. Low cardiac output developed in 3 of 16 patients, and pleural effusions developed in 5. The median length of hospital stay was 9 days. Activated complement C3 levels increased from a baseline of 1,486 +/- 564 to 4,600 +/- 454 ng/mL after cardiopulmonary bypass and administration of protamine, and returned to baseline by 24 hours. The level of interleukin-6 increased from 42 +/- 32 to 176 +/- 22 pg/mL and at 24 hours remained elevated at 71 +/- 15 pg/mL. Neither thromboxane B2 nor tumor necrosis factor-alpha levels increased significantly.nnnCONCLUSIONSnThe data demonstrate threefold to four-fold increases in activated complement C3 and interleukin-6, indicating that both humoral and cellular systems are affected. It is our conclusion that complement and cytokine activation may contribute to the delayed recovery observed after Fontan procedure.

Pharmacokinetic Evaluation of Triiodothyronine Supplementation in Children After Modified Fontan Procedure

BACKGROUNDnTriiodothyronine (T(3)) supplementation may be a useful adjunct in the management of patients after cardiopulmonary bypass. Limited data are available regarding the use and pharmacokinetics of T(3) in children. The present study was performed to evaluate T(3) pharmacokinetics in a cohort of children undergoing the modified Fontan procedure.nnnMETHODS AND RESULTSnA total of 28 patients were enrolled in this randomized, prospective study. The patients were divided into 4 groups: 1 group received a placebo and 3 groups received intravenous T(3) at dosages of 0.4, 0.6, and 0.8 microg/kg, respectively. All 28 patients survived their operative procedures. Two patients developed low cardiac output, and 3 patients had pleural effusions. The median length of hospital stay was 7 days. The mean free T(3) level was 316+/-67 pg/dL after then administration of a placebo. Patients who received T(3) had mean peak free T(3) levels of 972+/-88, 1351+/-299, and 1869+/-281 pg/dL for the dosages of 0.4, 0.6, and 0.8 microg/kg, respectively. The calculated half-life of T(3) was 7 hours.nnnCONCLUSIONSnThe half-life of intravenous T(3) in children is approximately one-third of that reported for adults. These results provide a framework for studying the efficacy of T(3) supplementation in children undergoing open-heart surgery.

Comparison of the Hormonal Response After Bidirectional Glenn and Fontan Procedures

Fluid retention is a frequent complication after the bidirectional Glenn and Fontan procedures. It was our hypothesis that this fluid retention may have a hormonal basis. To test this hypothesis, we made serial determinations of antidiuretic hormone, cortisol, aldosterone, angiotensin, and renin before and after operation in patients undergoing a bidirectional Glenn (n = 15) or Fontan (n = 18) procedure. Patients undergoing a bidirectional Glenn procedure had elevations in antidiuretic hormone, cortisol, and aldosterone immediately after operation. However, none of the hormonal elevations persisted by the fifth postoperative day. In contrast, patients undergoing a Fontan procedure had elevations in antidiuretic hormone, cortisol, aldosterone, renin, and angiotensin II in the immediate postoperative period. Five days postoperatively, the renin and angiotensin II levels remained elevated compared with the preoperative values. The data demonstrate that patients undergoing a bidirectional Glenn procedure and those undergoing a Fontan procedure have different patterns of hormonal response. These results suggest that hormonal factors may contribute to fluid retention after these operations.

The Damus-Fontan procedure

The Damus-Kaye-Stansel operation is a useful technique for the treatment of complex cyanotic congenital heart disease when there is obstruction between the systemic ventricle and the aorta. Modifications of the technique include transection of the aorta and the pulmonary artery, anastomosis of the contiguous aortic and pulmonary walls, and connection of the distal aorta to the perimeter of the new bivalved proximal great artery. In addition, the bidirectional cavopulmonary shunt technique can be used with or without the Fontan procedure. Six patients underwent a Damus-Fontan operation, and all survived. Two patients underwent the Damus-cavopulmonary shunt (hemi-Fontan) procedure, and 1 survived. The postoperative status of the 7 survivors is good to excellent. Follow-up ranges from 2 months to 7 1/2 years.

Suppression of the Pituitary Thyroid Axis After Cardiopulmonary Bypass in the Neonate

Thyroid hormone has numerous effects on cardiovascular function in the adult. The present study was undertaken to evaluate the effects of cardiopulmonary bypass and deep hypothermia on thyroid function in the neonate. Ten newborns were studied preoperatively and postoperatively. The total and free triiodothyronine, total and free thyroxine, thyroid-stimulating hormone, and thyroglobulin levels were measured by immunoassays. The data demonstrated a transient rise in the free thyroxine level associated with and followed by significant reductions in the free and total triiodothyronine, total thyroxine, thyroid-stimulating hormone, and thyroglobulin levels in the early postoperative period. By the fifth postoperative day, the free and total triiodothyronine and total thyroxine levels were returning toward the preoperative levels under the influence of an elevated thyroid-stimulating hormone level. These results suggest that the combination of cardiopulmonary bypass and deep hypothermia can result in a transient suppression of the pituitary-thyroid axis in the neonate.

Damus-Kaye-Stansel procedure: Midterm follow-up and technical considerations

The Damus-Kaye-Stansel operation is useful in the management of complex congenital heart defects. We reviewed our experience with 23 patients who underwent a Damus-Kaye-Stansel procedure. The anastomotic technique was individualized depending on the anatomy. The aortic and pulmonary artery incisions were carried into the sinuses of Valsalva in 9 patients, the aorta was transected in 11 patients, and a patch was used to augment the anastomosis in 13 patients. Concurrent procedures included a Fontan operation (n = 9, mortality = 0), right ventricle-pulmonary artery conduit (n = 5, mortality = 0), bidirectional Glenn procedure (n = 6, mortality = 1), and central aortopulmonary shunt (n = 3, mortality = 2; emergency = 1). Survival is 87% with a median follow-up of 7 years (range, 2 months to 9.2 years). Four patients underwent late revision of the Damus-Kaye-Stansel connection. All survivors are asymptomatic. We conclude that the Damus-Kaye-Stansel connection provides excellent midterm results when the proximal anastomosis is adapted to the anatomy of the patient.