Twenty-five years' experience with the arterial switch operation.

OBJECTIVE: The arterial switch operation was introduced in 1976 to correct transposition of the great arteries and has since replaced atrial palliation. This study examines the long-term outcomes of the arterial switch operation. METHODS: Included in the study were 195 patients who underwent the arterial switch operation from 1977 through June 2000. Patients were evaluated for functional class, pulmonary stenosis, left ventricular function, arrhythmias, aortic sequelae, and coronary disease. RESULTS: Overall perioperative mortality was 15%, but rates dropped in the last 5 years to 4% for complex transposition and 0% for simple transposition. Of 151 survivors, 2 died late; 1 died of persisting pulmonary hypertension and 1 died of ventricular fibrillation after coronary pathologic changes. At last follow-up, a total of 145 patients were in New York Heart Association functional class I and 4 patients were in class II. The most frequent complication was pulmonary stenosis, necessitating 45 reinterventions in 26 patients. Left ventricular dysfunction was noted in 5 patients. Arrhythmias were seen in 5 patients: 2 patients had ventricular fibrillation (1 died and 1 required a defibrillator implantation), 1 had sick sinus syndrome, 1 had atrial flutter, and 1 had a single attack of supraventricular tachycardia. Aortic valve incompetence was absent or trivial in 146 patients, 3 had mild incompetence, 1 had moderate incompetence, and 1 had severe incompetence. Coronary sequelae were found in 5 of the 61 patients who underwent angiography. CONCLUSION: Long-term clinical outcome of the arterial switch operation is good, and perioperative mortality is now low. Morbidity is dominated by pulmonary stenosis and coronary artery disease, with the potential for lethal arrhythmias.

Lactacidosis in the neonate is minimized by prenatal detection of congenital heart disease.

OBJECTIVES: To investigate the impact of prenatal detection of congenital heart disease on preventing severe preoperative lactacidosis. DESIGN: Patients operated upon for congenital heart disease during the first 31 days of life (n = 209) were studied retrospectively, 21 were diagnosed prenatally and 188 patients had not been diagnosed prenatally. Preoperative lactate, pH and base excess were evaluated. RESULTS: Differences were noted in preoperative pH (7.28 +/- 0.03 vs. 7.24 +/- 0.01, P = 0.29), base excess (-5.83 +/- 0.64 vs. -6.93 +/- 0.46 mmol/L, P = 0.10) and lactate (3.05 +/- 0.35 vs. 6.08 +/- 0.45 mmol/L, P < 0.001), indicating a significant difference in blood lactate values in favor of the prenatally diagnosed group. CONCLUSIONS: Prenatal diagnosis of congenital heart disease and the resulting immediate postnatal care prevent lactate increase in the preoperative period of these patients. This may decrease the risk of cerebral damage and result in the patient being in better condition at surgery.

Fate of the aortic root after arterial switch operation.

OBJECTIVE: Concerns have been voiced about possible dilation and insufficiency of the neo-aortic valve after the arterial switch operation (ASO). AIMS: To determine growth of the neo-aortic valve and the aortic anastomosis after ASO and the prevalence of insufficiency or stenosis. PATIENTS AND METHODS: Since 1977, 144 consecutive patients (pts) underwent ASO for transposition of the great arteries (TGA). Median follow-up was 8.65 years (0.1--22.5 years). Simple TGA was present in 97 pts and 47 had TGA with ventricular septal defect (VSD). Detailed echocardiography included measurements of aortic diameter at four levels. The 608 measurements were compared with published normal values. RESULTS: The mean aortic valve z-score was 1.5, without significant change with age (P=0.75). Under 4 months, mean valve z-score was 0.63+/-2.20, between 5 and 12 months 2.56+/-2.30 (P<0.0001). Gradual growth occurs thereafter. The aortic sinus follows an identical growth pattern. The aorta at the anastomosis, is initially smaller than normal (z-score -0.64). After 4 months the z-score is 0.83, followed by continued growth of 0.1 z-score per year. At the last visit, the aortic valve z-score was above 2 in 51 patients, between -2 and 2 in 72 and less than -2 in six patients, none of whom had a flow velocity above 2 m/s. z-score of patients with VSD remained above those without VSD (P<0.0001). Aortic insufficiency was grade 2/4 in three patients, grade 3/4 in one and grade 4/4 in one. No patient developed aortic stenosis. CONCLUSION: After ASO the neo-aortic valve and sinus are larger than normal, representing the natural size difference in the prenatal situation and influence of associated cardiac malformations. In the first year of life, rapid dilatation of the new aorta is observed, followed by growth towards normalization of the valve and sinus size. Stenosis at the anastomosis was not observed. Aortic dilatation by itself is rarely associated with significant insufficiency.

Prenatal diagnosis of congenital heart disease affects preoperative acidosis in the newborn patient.

OBJECTIVES: Congenital heart disease is the leading cause of death in the first year after birth. Prenatal diagnosis of the disease can optimize the preoperative condition of the patient and may help in the prevention of acidosis. In this retrospective study we compared the occurrence of metabolic acidosis in patients with and without prenatal diagnosis of a congenital heart disease. METHODS: Data of 408 patients who needed an operation for congenital heart disease within 31 days of life were analyzed retrospectively. Arterial blood gases at fixed time intervals and worst blood gas of 81 patients with and 327 patients without a prenatal diagnosis were compared, categorizing the patients on ductus dependency, anticipated univentricular or biventricular repair, and left-sided, right-sided, or no heart obstruction. RESULTS: In the overall group significant differences in lowest pH, lowest base excess, and highest lactate level were found, with metabolic acidosis more common among the patients with a postnatal diagnosis. In the group of patients with ductus-dependent congenital heart disease, the difference between patients receiving a prenatal and those receiving a postnatal diagnosis was more significant than in the group with non-ductus-dependent lesions. Analyzing patients with right-sided, left-sided, and no obstruction separately, significant differences were found in the group with left-sided heart obstruction for lowest pH and base excess and in the group with right-sided heart obstruction for lowest base excess. CONCLUSIONS: Prenatal diagnosis of congenital heart disease minimizes metabolic acidosis in patients with congenital heart disease and may be associated with improved long-term outcome and prevention of cerebral damage among this fragile group of patients, although no significant effect on direct surgical outcome was encountered.

[Rupture of thoracic aneurysm in a 10-year old boy]. / Ruptuur van een thoracaal aneurysma bij een 10-jarige jongen.

A 10-year-old boy with a medical history of fatigue became nauseous, short of breath and cyanotic within 24 hours after a frightening incident. He was successfully resuscitated after a cardiac arrest. A CT scan revealed a ruptured aneurysm of the ascending aorta. During emergency surgery the ascending aorta and aortic arch were replaced with a 22 mm synthetic graft. No postoperative complications occurred. There was no associated trauma, syphilis, collagen diseases (Marfan's syndrome, Ehlers-Danlos syndrome), congenital heart disease or autoimmune disease. The cause of the aneurysm and rupture remain unclear.

[Arterial-switch operation for transposition of the great vessels; good results in the Wilhelmina Children's Hospital, Utrecht, 1977-2000]. / Arteriële-switchoperatie bij transpositie van de grote vaten; gunstige resultaten in het Wilhelmina Kinderziekenhuis Utrecht, 1977-2000.

OBJECTIVE: To examine the results of the arterial switch operation which is used to correct the transposition of the great arteries. DESIGN: Descriptive. METHOD: In the period May 1977-October 2000 195 patients at the Wilhelmina Children's Hospital in Utrecht, the Netherlands, underwent an arterial switch operation. The patient group consisted of 132 boys and 63 girls, with a median age at surgery of 8 days (range: 0-1976). In accordance with the protocol, the postoperative follow-up consisted of echocardiography and an ECG. Further investigations were performed on indication. Additional data were collected from the status reports. The mean follow-up was 8.0 years (range: 0.04-22.17). RESULTS: The overall peri-operative mortality was 15% (30/195). Initially this figure was about 50%, in the 1980s it was 15% and from 1996 onwards it was 4%. Of the 151 surviving and traceable patients, 2 patients died years later (1.3%). Of the remaining 149 patients, 145 were classified in New York Heart Association class I and 4 in class II. Due to pulmonary stenosis, 45 reinterventions were required in 26 patients (/149; 17%). Left ventricle dysfunction occurred in 5 patients (3%), arrhythmias in 5 patients and aorta abnormalities in 5 patients. Coronary artery abnormalities were found in 5 of the 61 patients who underwent angiography (8%). CONCLUSION: Peri-operative mortality decreased to 4% and late mortality was 1.3%. The long-term clinical outcome of the arterial switch operation was good. Morbidity was predominantly caused by pulmonary stenosis and late coronary obstruction.

Right ventricular dysfunction and the role of pulmonary valve replacement after correction of tetralogy of Fallot.

BACKGROUND: Correction of tetralogy of Fallot (ToF) often leads to pulmonary regurgitation, sometimes warranting pulmonary valve replacement (PVR), for which the indications and timing to achieve optimal results are not yet clear. This retrospective study describes follow-up and reinterventions in our ToF population. METHODS: Review of all consecutive patients operated for ToF between 1977 and 2000. Included are date and type of repair, Doppler echocardiography (2D-echo), ECGs, re-operations and physical condition. RESULTS: Total repair was performed in 270 patients, mean age 1.9±2.5 years, 82 were excluded because of follow-up abroad. Right ventriculotomy was used in 92%, transatrial VSD closure in 8%, while 69% received a transannular outflow patch. Pulmonary atresia required a pulmonary graft in 13 (8%) patients. Overall 20-year survival was 88%. Last follow-up: ECG showed RBBB in 67% (QRS complex 129±29.3 msec). RVOT aneurysms were detected in 16%. 2D-echo demonstrated mild pulmonary insufficiency (PI) in 40%, severe in 31%, dilated RV in 76%, both increasing with post-repair age. In 39%, RV dimensions were equal or even exceeded LV dimensions, 45% showed tricuspid insufficiency and the RA was enlarged in 14%. Reintervention was necessary in 39/185 patients, this included angioplasty for residual stenosis and PVR (22/19 homografts, six patients in PA group) at a mean age of 11.2 years after correction. In seven patients, the RV returned to normal dimensions and symptoms disappeared, but in three severe dysfunction developed. Eleven others still have RV dilatation and/or PI. In total, 75% were free of reintervention in the first ten years. The right atrial approach diminishes severe RV dilatation and prolonged QRS duration (p=0.001 and 0.007). Early correction reduces the risk of re-operation (p=0.011). CONCLUSIONS: Severe RV dilatation (39%) and PI (31%) secondary to outflow tract repair in ToF are frequently occurring sequels developing slowly over time. Timing of PVR remains controversial, still best guided by the clinical condition.

Influence of coronary anatomy and reimplantation on the long-term outcome of the arterial switch.

BACKGROUND: Abnormal coronary artery anatomy is reported to have a significant influence on the outcome of the arterial switch operation. This study examines the impact of coronary anatomy and the occurrence of late coronary obstruction on left ventricular (LV) function and long-term outcome. METHODS: Coronary artery anatomy, of 170 patients after arterial switch operation (1977-1999), was determined based on operative reports and pre-operative aortograms. Current status was evaluated using ECGs, echocardiograms, scintigraphy, and post-operative coronary angiograms. RESULTS: In 133/170 patients, coronary artery anatomy consisted of an anterior descending (LAD) and circumflex artery (Cx) from the left sinus and the right coronary artery (RCA) from the right or posterior sinus. The left coronary had an intramural initial course in two of these patients. Fifteen patients had the LAD from the left and Cx and RCA from the right sinus; eight had LAD and RCA from one sinus and Cx from the other; four had single ostium; and three had three separate ostia. Four patients had complex patterns and four patients had a supra commissural coronary. To date, follow-up angiography was performed in 59 patients. Surgical coronary sequellae were found in five patients. Two patients had an occluded left ostium. Initially, they were asymptomatic but showed polymorphic ventricular extrasystoles on ECG and moderate LV dysfunction with large irreversible perfusion defects on scintigraphy. Both patients developed ventricular fibrillation at the age of 14 years. One patient did not survive. The other patient required implantation of a defibrillator. One patient has an occluded RCA, one patient has stenosis of the right ostium and one patient has multiple tortuous collaterals without obstruction of a major branch. In the latter three patients, coronary sequellae were not suspected on ECG, echo, or scintigraphy and were only found on follow-up angiography. Retrograde collateral flow was noted in all three occluded coronaries. LV dysfunction, with normal coronaries, was noted in three patients. All, of these patients, had peri-operative ischaemia suggesting failure of myocardial protection. Two are now asymptomatic with mild LV dysfunction. One patient continues to have severe myocardial dysfunction and secondary aortic insufficiency. A Ross-like procedure was performed placing the original aortic valve in the neo-aortic root. Coronary artery anatomy did not influence early survival or late coronary sequellae. CONCLUSION: Abnormal coronary anatomy was not a determinant of outcome in our study. Surgical coronary obstruction is independent of original anatomy. It can be almost silent and is potentially fatal. Follow-up angiography must be considered in all patients after the arterial switch operation.

[Heart transplantation in the Netherlands, an option to be considered for 5 children per year on the average]. / Harttransplantatie in Nederland; een te overwegen optie voor gemiddeld 5 kinderen per jaar.

OBJECTIVE: To assess the number of possible candidates for paediatric cardiac transplantation and the number of available donors. DESIGN: Retrospective. PATIENTS AND METHODS: The population (date of birth 1 January 1980-31 March 1998) of the Department of Paediatric Cardiology of the Wilhelmina Children's Hospital, Utrecht, the Netherlands, was reviewed for possible candidates for cardiac transplantation and the resulting number of candidates was extrapolated to the entire country. Figures of the transplant co-ordination unit of the University Hospital Utrecht over 1993-1997 were obtained, to estimate the number of available donors. Furthermore, an overview was made of the results of paediatric cardiac transplantations reported in centres around the world. RESULTS: A total number of 15 possible candidates could be selected over the studied period. Extrapolated to the entire country, about 5 candidates each year could be expected. Per year 5 donor hearts of children (< 12 yr) and 11 hearts of adult donors with a low body weight (40-65 kg) have been available for paediatric cardiac transplantation. Worldwide 5- and 10-year survival rates reach 60% and 50%, respectively, morbidity seems low and the quality of life can be considered reasonably good. CONCLUSION: The number of expected recipients corresponds with the number of available donors. Together with the promising results reported in transplant centres around the world, this seems to justify the option of paediatric cardiac transplantation for children with end-stage cardiac disease.

Competitive pulmonary flow in infancy: the effect of respiration.

Superior caval flow during positive pressure mechanical ventilation and spontaneous breathing was investigated by Doppler echocardiography in a neonate with a coexisting superior cavopulmonary shunt and an aortopulmonary shunt. During positive pressure ventilation, retrograde systolic flow in the superior vena cava was recorded, with low velocity anterograde flow. This pattern was reversed during spontaneous respiration. Low intrathoracic pressure plays an important role in maintaining anterograde pulmonary blood flow in patients with this physiology.

Double chambered right ventricle: delineation by multiplane transoesophageal echocardiography.

Three consecutive patients (median age 5 years; median weight 15 kg) with double chambered right ventricle (DCRV) were studied by multiplane transoesophageal echocardiography (TOE), using a specially designed paediatric probe. Using a 30 degrees angulation from the longitudinal plane, the body and outflow tract of the right ventricle could be imaged with minimal foreshortening, allowing detailed description of the level and nature of obstruction. In all cases, angiography and subsequent surgical inspection confirmed the TOE findings. Multiplane TOE should avoid the necessity for angiography in the preoperative assessment of this unusual lesion.

Reduction of reperfusion injury of human myocardium by allopurinol: a clinical study.

To determine the possibility of myocardial protection against reperfusion injury by allopurinol, 22 aortocoronary bypass patients were studied. Eight patients received allopurinol (200 mg during induction of anesthesia and 100 mg after starting extracorporeal circulation) during surgery (group B), and 14 patients served as a control (group A). Blood samples and myocardial biopsies were taken before and 10 min after aortic cross-clamping. No statistically significant difference between the two groups was observed considering gender, age, prior myocardial infarction, left ventricular end diastolic pressure (LVEDP), and aortic cross-clamp time. Preservation of cardiac tissue was assessed by the measurement of quantitative birefringence (QBR) changes upon the addition of adenosine 5'-triphosphate (ATP) plus calcium in biopsies and the need for postoperative inotropes. The synthesis of peroxides was estimated by the measurement of leukotriene B4 and C4 (LTB4, LTC4). LTB4 was below the level of detection (< 1.5 ng/l) before and after cross-clamping in both groups, while the LTC4 level for group A increased from < 1.5 to 27 +/- 17 ng/l compared to an increase of < 1.5 to 11 +/- 8 ng/l for group B after 10 min of reperfusion (p = .036). The decrease in QBR value in group A was 1.26 +/- 0.28 and 0.35 +/- 0.23 for group B (p < .003). Postoperatively, 11 out of 14 patients in group A needed inotropic support (dopamine or dobutamine), whereas two patients out of eight did so in group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Late re-interventions following arterial switch operations in transposition of the great arteries. Incidence and surgical treatment of postoperative pulmonary stenosis.

Seventy-six patients were studied after arterial switch operation (ASO) between May 1977 and February 1992. Pulmonary artery reconstruction was initially performed by: conduit interposition in 5 patients, direct main pulmonary artery anastomosis and button patches in 60 patients, and pantaloon-like patch repair in 11 patients. Pulmonary stenosis developed in 17 patients (22%), requiring a total of 26 late re-interventions. Re-intervention was required in four out of five patients operated with pulmonary artery conduits, 11 out of 60 with a button patch repair and 2 out of 11 following pantaloon-type repair. In this series pulmonary artery stenosis (PS) involving the pulmonary valve occurred in 9/17 patients. Involvement of the pulmonary valve was related to the technique of pulmonary artery reconstruction. In these patients surgery is necessary. Balloon angioplasty can be a valuable tool when the stenosis is more distal. The incidence of PS was not influenced by the type of reconstruction or the use of Lecompte's maneuver.

Management of ventricular septal defect with associated aortic incompetence.

Twenty-two patients with a ventricular septal defect and aortic incompetence underwent surgical repair. Mean age was 9.6 years (range, 9 to 15 years). Mean follow-up was 32.4 +/- 15.8 months. The ventricular septal defect was perimembranous in 19 patients and doubly committed or juxtaarterial in 3. Most showed only a small left-to-right shunt. Mean diameter was 11.9 +/- 4.8 mm. Aortic incompetence was mild in 6 patients, moderate in 4, and severe in 12. In 16 patients closure of the ventricular septal defect and aortic valvoplasty were both performed through the aortic root. There were no deaths. All patients retained normal sinus rhythm. No complete heart block was found. In 3 patients secondary aortic valve replacement was required for severe incompetence; in 1 the cause was bacterial endocarditis, in another technical failure, and in a third progressive incompetence over an 8-month period. All patients showed substantial clinical improvement, marked decrease or disappearance of the valvar incompetence, diminution of the left ventricular end-diastolic diameter, and decreased cardiothoracic ratio. We conclude that primary repair is the operation of choice for this combination of lesions. This can avoid or delay considerably valvar replacement. The left-sided approach proves safe and is our preferred technique.

Constrictive pericarditis caused by primary liposarcoma.

A 30 year old man presented with symptoms of constrictive pericarditis. Echocardiography and computed tomography showed a mass extending from the pericardium to surround the heart and penetrating the left ventricular apex. An unresectable pleomorphic liposarcoma arising from the pericardium was found at thoracotomy.

Epicardial cryosurgery as used in ablation of accessory atrioventricular pathways: effect on valvular function in the dog.

Epicardial cryosurgery for ablation of atrioventricular accessory pathways has surgical advantages. However, it is applied directly to the valve base. To assess the risk of valve impairment, 10 anaesthetized dogs were subjected to standardized epicardial cryosurgery of the right atrioventricular junction. Two of these underwent sham procedure (dissection only). Valve function was assessed by colour Doppler echocardiography preoperatively and at 2 days, 1 week, 2 weeks and 10 weeks postoperatively. Three out of the eight animals subjected to cryosurgery developed moderate (grade 2/4) tricuspid insufficiency, which appeared at 1 week postoperatively, following regression of congestive oedema. Two out of the three cases of TI were associated with leaflet prolapse. No tricuspid insufficiency was seen in the sham-operated animals. At the end of each interval two animals were killed for histological examination. Histological examinations showed that cryolesions extended a maximum of 3 mm into the valve leaflet. The tricuspid insufficiency is attributed to the extensive scarring (including chondroid metaplasia), which causes retraction and restricted motion of the annulus. It is concluded that cryolesions may impair atrioventricular valve function. Patients undergoing cryosurgery should be monitored postoperatively by echocardiography for atrioventricular valve insufficiency.

Nd-YAG laser energy distribution in an artificial obstruction: influence of lasing parameters in a model of laser angioplasty.

A Nd-YAG laser (1064 nm) coupled to a silica fiber (0.6 mm core diameter) was used to create defects in a model of arterial vascular obstruction. We employed transparent agar doped with black ink as atheromatous material and studied the size and shape of defects created by various lasing parameter settings. By adding calcium sulphate to the agar its scattering properties were enhanced. The created defects correspond to a temperature boundary. The optical properties of the agar greatly influenced the size and shape of the created defects. In the agar with enhanced scattering properties, the created defects showed an unfavourable penetration width-depth ratio. Maximum width of penetration always exceeded the fiber diameter. This may contribute to an increased risk of vessel wall perforation in small vessels and, if the fiber is positioned close to the vessel wall, even when a coaxial position is maintained. With increasing cumulative energy, both maximum depth and width of penetration leveled off in both agars. The results suggest that agar can be used to obtain empirically the lasing parameters that will minimize the risk of vessel wall perforation by an axially positioned fiber. The agar model needs further study to determine its limitations, but agar seems to be a useful substitute for atheroma in the study of laser catheter angioplasty.