A novel method to identify an intramural segment in interarterial anomalous coronary arteries on CT-angiography

Background/Introduction

An anomalous coronary artery originating from the opposite sinus of Valsalva (ACAOS) with an interarterial course can be assessed using Computed Tomography Angiography (CTA) for the presence of high-risk characteristics associated with sudden cardiac death. These features include a slit-like ostium, acute angle take-off, and degree of proximal luminal narrowing. However, no robust CTA criteria currently exist to determine the presence of an intramural segment.

Purpose

The aim of this study is to deduct a method to accurately identify an intramural course of interarterial ACAOS on CTA imaging.

Methods

All consecutive adult patients with an interarterial ACAOS that were evaluated at the two academic hospitals between January 2010 and July 2019 were screened for inclusion. Inclusion criteria were availability of a preoperative CTA-scan (0.5–1mm slice-thickness) and peroperative confirmation of the intramural segment. Using multiplanar reconstruction of the CTA, the distance between the lumen of the aorta and the lumen of the ACAOS (defined as “interluminal space” (ILS)) was assessed at 2mm intervals along the intramural segment (Figure 1).

Results

Twenty-five patients (64% female, mean age 46 years, 88% right ACAOS) were included. Analysis showed a mean ILS of 0.69mm±0.15mm at 2mm from the ostium. At the end of the intramural segment where the ACAOS becomes non-intramural, the mean ILS was significantly larger (1.27±0.29mm, p<0.001) (Figure 2). Interobserver agreement evaluation showed good reproducibility of ILS (intraclass correlation coefficient 0.77, p<0.001). ROC-analysis demonstrated that at a cut-off ILS of ≤0.95mm, an intramural segment can be diagnosed with 100% sensitivity and 84% specificity.

Conclusion(s)

The ILS is introduced as novel and robust CTA parameter to identify an intramural course of interarterial ACAOS. An ILS of ≤0.95mm is indicative of an intramural segment with 100% sensitivity and 84% specificity.

Funding Acknowledgement

Type of funding sources: None.

Non-invasive identification of slow conducting anatomical isthmuses in patients with tetralogy of Fallot by 3D late gadolinium enhancement cardiovascular magnetic resonance

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with repaired tetralogy of Fallot (rTOF) remain at risk of sudden cardiac death due to reentrant sustained monomorphic ventricular tachycardia (SMVT). Slow conducting anatomical isthmuses (SCAI), in particular SCAI3 at the outlet septum, bordered by the pulmonary annulus and the ventricular septal defect patch, are the dominant substrate for SMVT. Electroanatomical mapping (EAM) is the invasive gold standard to identify SCAIs, and transection of SCAI by catheter ablation has been correlated with favorable long-term outcome. Non-invasive identification of SCAI for risk stratification and treatment planning is needed but has not been established yet. Three-dimensional (3D) late gadolinium-enhanced (LGE) cardiovascular magnetic resonance (CMR) facilitates accurate visualization of morphologically complex hearts with high-spatial resolution.

Objective

The study thought to determine whether 3D LGE-CMR can identify SCAIs.

Methods

Consecutive patients with rTOF who underwent right ventricular (RV) EAM and 3D LGE-CMR were included. LGE-CMR-derived 3D RV reconstructions were created (ADAS-3D) and merged with 3D RV EAM data. Mapping points were superimposed on the CMR-derived 3D reconstruction allowing for direct comparison of EAM data and local signal intensity (SI). The optimal SI cut-off to identify low bipolar voltage (LBV, BV<1.76mV) was determined by receiver operating characteristic carve. An abnormal AI on LGE-CMR was defined as AI with continuous SI above the obtained cut-off connecting AI borders.

Results

Forty-eight rTOF patients (34±16 years, 58% male) were included. At EAM, 21 patients had normal AI, and 20 and 7 had a SCAI (<0.5m/s) or blocked AI, which was AI3 in all. Patients with SCAI showed low BV of AI3 (median 0.7 [range 0.25-2.59] mV). In 11 patients, 14 SMVTs could be induced, all related to SCAI3.

A total of 9240 points were analyzed, showing a significant correlation between BV and SI (R=0.4, P<0.001). The optimal SI cut-off to identify LBV was 42% of the maximal SI (MSI) (AUC 0.80; sensitivity, 74%; specificity, 78%). Using this cut-off of MSI, a SCAI or blocked AI3 could be correctly identified by LGE-CMR in all 27 patients, and a normal AI3 could be correctly confirmed by LGE-CMR in 14/21 patients with normal EAM findings (Figure). The sensitivity and specificity of 3D LGE-CMR for identifying SCAI or blocked AI3 were 100% and 67%, respectively. Of note, among patients with normal EAM findings, those with abnormal AI3 on LGE-CMR had significantly lower BV of AI3 than those with normal AI3 on LGE-CMR (2.06 [Range, 1.62-2.60] vs. 3.53 [2.22-5.67] mV, P<0.01).

Conclusion

3D LGE-CMR can identify SCAI with 100% sensitivity and may identify diseased AI3 even before critical conduction delay occurs. This technique may allow for non-invasive risk stratification of VT and can refine patient selection for invasive EAM.

The effects of high-degree AV block requiring chronic ventricular pacing after tricuspid valve surgery in patients with a systemic right ventricle

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with transposition of the great arteries(TGA) after atrial switch or congenitally corrected TGA(ccTGA) are prone to systemic right ventricular(sRV) failure. Atrioventricular(AV)-conduction disturbances requiring chronic ventricular pacing and tricuspid valve(TV) regurgitation aggravate sRV dysfunction. Timely TV surgery stabilizes sRV function, yet is a risk factor for AV-block, potentially contributing to sRV failure due to pacing-induced dyssynchrony. The aim of this study is to explore the incidence, timing and functional consequences of AV-block requiring ventricular pacing after TV surgery in sRV patients.

Methods

Consecutive adolescent and adult patients with a sRV who underwent TV surgery in the period 1989-2020 and follow-up at our centre were included in this observational cohort study. Demographic and clinical data was collected from patient records.

Results

Data of 28 patients(54% female, 57% ccTGA, mean age at surgery 38±13 years) was analysed. Mean follow-up duration was 9.7±6.8 years. Five patients(18%) already had chronic(>40%) subpulmonary left ventricular pacing preoperatively, of which 2 received cardiac resynchronization therapy(CRT) upgrade prior to surgery. One patient received CRT during TV surgery. Of the remaining 22 patients at risk for AV-block after surgery, 9(41%) developed an indication for chronic pacing during follow-up, of which 3(33%) before hospital discharge and a total of 5(56%) within 24 months postoperatively, Figure 1. Five(20%) patients received CRT during follow-up due to progressive heart failure(HF). In one patient with transvenous upgrade, effective resynchronization was not attained due to suboptimal lead position. Of the patients receiving chronic pacing, 9(75%) died, underwent ventricular assist device(VAD) implantation or required CRT due to progressive HF. Only 4(31%) patients with native AV-conduction reached this composite endpoint(p=0.027). QRS duration, a surrogate marker for dyssynchrony, was significantly higher in patients with chronic pacing than with native AV-conduction(217±24 vs 116±23msec, p=0.000), as was NT-pro-BNP(2746[1242–6879] vs 495[355–690]ng/L, p=0.004) and the percentage of patients with ≥1 class of deterioration of systolic sRV function(p=0.001), Figure 2.

Conclusions

Patients with a failing sRV who undergo TV surgery are prone to AV-conduction abnormalities with 41% developing an indication for chronic ventricular pacing during follow-up. The patient group with chronic pacing has significantly more events of the composite endpoint of death, VAD implantation or upgrade to CRT, higher percentage of ≥1 grade deterioration of systolic sRV function and higher levels of HF biomarker NT-pro-BNP. Implantation of an epicardial sRV lead at the time of TV surgery for future CRT may be considered to attenuate the detrimental effects of subpulmonary ventricular pacing in this HF prone patient group with complex anatomy that limits transvenous possibilities.

Clinical decision making in frequently encountered anomalous aortic origin of coronary arteries, the impact of IVUS

Introduction

The aim in the diagnostic work-up of patients with an anomalous aortic origin of coronary arteries (AAOCA) is to determine whether the course of the coronary artery is benign or malignant. In patients with AAOCA with an interarterial course the guidelines on diagnostics are concise. Recommended CT-scan imaging does not evaluate stress-induced functional consequences like external compression by the pulmonary artery as the scan is performed in a resting state. Non-invasive ischemia detection techniques often lack sufficient sensitivity. To improve functional stratification, exploration of new diagnostic modalities in the diagnostic workup of AAOCA is mandatory.

Purpose

The purpose is to explore the potential role of intravascular ultrasound (IVUS) in the diagnostic workup of patients with AAOCA.

Methods

Nine patients with an anomalous right coronary artery with an interarterial course were analyzed. A cardiologist evaluated the complaints. Anatomical features of the AAOCA were assessed with CT-scan imaging. Further analyses included ischemia detection and coronary angiography. To assess stress-induced ischemia IVUS and invasive measurements – fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) – were performed at rest and during adrenaline-induced stress. A slit-like orifice was classified as a width/length (W/L) ratio of ≤0.50, an oval orifice as 0.51–0.9 and a round orifice as >0.91.

Results

Potential cardiac complaints were present in seven patients. In 8 (89%) patients CT-images showed an acute angle, in 8 (89%) proximal narrowing and an aortic take-off above the pulmonary valve in 4 (44%). In 7 (78%) patients a slit-like orifice and in two (22%) an oval orifice were observed (table 1). IVUS at rest showed a slit-like orifice in one patient classified as an oval orifice on the CT-images and vice versa in another patient (table 2). The patients classified as an oval orifice with IVUS showed no external compression during adrenaline-induced stress. In 4 (57%) out of 7 patients with an slit-like orifice on IVUS, the width remained unchanged or increased during adrenaline infusion. In 2 patients the width decreased slightly, however, these patients were asymptomatic and no ischemia was detected. In 1 (14%) patient the width remained 1.4mmm and the length increased from 3.2mm to 4.7mm. In this case the vessel ostium was fully engaged with the IVUS catheter, hence, the width could not decrease during adrenaline infusion. This was regarded as external compression. In addition, in this patient ischemia was detected.

Conclusion(s)

In two (22%) out of 9 patients IVUS gave a better insight of the shape of the orifice than CT. Additionally, the anatomic and functional-dynamic components of compression could be defined with adrenaline-induced stress. Therefore, IVUS can contribute to a better understanding of the functional consequences of the anatomical features and of potential stress-induced external compression.

Funding Acknowledgement

Type of funding sources: None. Table 1Table 2

The coronary arteries in adults after arterial switch: a systematic review

Background

Coronary artery status in adults longterm after the arterial switch operation (ASO) is unclear. As a consequence, current follow-up strategies for coronary assessment remain controversial. We conducted a systemic review to provide an overview of coronary complications during adulthood and to evaluate the value of coronary imaging in adults after ASO, in light of current guidelines.

Material and method

Studies describing coronary complications or coronary imaging after ASO in adults were considered eligible for review and analysis. Articles were screened for the inclusion of adult ASO patients and data on coronary complications and findings of coronary imaging were collected. In cohort studies with both adults (≥18 years) and non-adults (<18 years) only outcomes in identifiable adults were analyzed.

Results

A total of 993 adults were followed with a median follow-up of 2.0 years after reaching adulthood. Myocardial ischemia was suspected in 16/192 patients (6.8%). The number of coronary interventions was 4 (0.4%) and coronary death was reported in 4 (0.4%) patients. The following coronary abnormalities were found by routine coronary computer tomography CT (cCT): stenosis (4%), acute angle (40%), kinking (24%) and interaterial course (11%). No coronary events were reported during pregnancy (n=45).

Conclusion

The reported number of coronary interventions (0.4%) and of coronary death (0.4%) during a median follow-up of 2 years in 993 ASO adults is low. Coronary abnormalities including acute angle, kinking and interarterial course were commonly found by cCT. The 2020 European Society of Cardiology (ESC) guidelines state that routine screening for coronary pathologies is questionable. However, based on current findings and in line with the 2018 American ACC/AHA guidelines we suggest a baseline assessment of the coronary arteries in all adult ASO patients. Thereafter, an individualized coronary follow-up strategy, based upon coronary findings, is advisable.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Hartstichting Freedom from coronary complications

Atrioventricular-block necessitating ventricular pacing after tricuspid valve surgery in patients with a systemic right ventricle: long term follow-up

Background

Patients with transposition of the great arteries (TGA) after atrial switch or congenitally corrected TGA (ccTGA) are prone to systemic right ventricular (sRV) failure. Atrioventricular (AV)-conduction disturbances and tricuspid regurgitation aggravate the course of sRV dysfunction. Timely tricuspid valve (TV) surgery stabilizes sRV function. However, TV surgery is an independent risk for AV-block and ventricular pacing in non-congenital cardiothoracic surgery patients. Chronic subpulmonary ventricular pacing-induced dyssynchrony further contributes to sRV failure, potentially reducing the beneficial effects of the tricuspid valve surgery.

Purpose

The aim of this study is to explore the incidence, timing and functional consequences of AV-conduction block requiring ventricular pacing after TV surgery in sRV patients.

Methods

Consecutive adolescent and adult patients with a sRV who underwent TV surgery in the period 1989–2020 and follow-up at our tertiary care center were included in this observational cohort study. Patients who were <10 years of age at the time of operation and/or died in perioperative, in-hospital, setting were excluded from analysis (n=5). Demographic and clinical data was collected from the patient records.

Results

Data of 28 patients (54% female, 57% ccTGA) was analysed (Figure). The mean age at surgery was 38±13 years, 5 patients (18%) received chronic ventricular pacing preoperatively. Mean follow-up was 9.7±6.8 years, during which 7 patients (25%) died and 3 (11%) underwent ventricular assist device implantation (VAD). Two patients died awaiting VAD/HTx, one patient died awaiting CRT upgrade. Seven (25%) patients underwent a re-operation, of which 3 (11%) TV replacement, 3 (11%) VAD and 1 (4%) pulmonary valve replacement. Of the 23 patients at risk of developing AV-block, 11 (48%) developed an indication for chronic ventricular pacing, of which 6 within 24 months postoperatively (4 before hospital discharge). Of the 21 patients with a device, 7 (25%) had successful resynchronization therapy (2 before TV surgery). Patients with chronic ventricular pacing had a wider QRS-duration (mean 121 ms vs 194 ms in those without pacing, p<0.001) and 43% had a severely reduced sRV function (vs 36% in those without pacing) at latest follow-up.

Conclusions

Patients with a failing sRV who undergo TV surgery are prone to AV-conduction abnormalities with 48% of this group developing an indication for chronic ventricular pacing during follow-up. Pacing-induced dyssynchrony can further contribute to sRV dysfunction. Implantation of an epicardial sRV lead at the time of TV surgery for future CRT may be considered to attenuate the detrimental effects of subpulmonary ventricular pacing in this heart failure prone patient group with complex anatomy, limiting transvenous possibilities.

Funding Acknowledgement

Type of funding sources: None.

The first multicentre study on coronary anomalies in the Netherlands: MuSCAT

Background

Current guidelines on coronary anomalies are primarily based on expert consensus and a limited number of trials. A gold standard for diagnosis and a consensus on the treatment strategy in this patient group are lacking, especially for patients with an anomalous origin of a coronary artery from the opposite sinus of Valsalva (ACAOS) with an interarterial course.

Aim

To provide evidence-substantiated recommendations for diagnostic work-up, treatment and follow-up of patients with anomalous coronary arteries.

Methods

A clinical care pathway for patients with ACAOS was established by six Dutch centres. Prospectively included patients undergo work-up according to protocol using computed tomography (CT) angiography, ischaemia detection, echocardiography and coronary angiography with intracoronary measurements to assess anatomical and physiological characteristics of the ACAOS. Surgical and functional follow-up results are evaluated by CT angiography, ischaemia detection and a quality-of-life questionnaire. Patient inclusion for the first multicentre study on coronary anomalies in the Netherlands started in 2020 and will continue for at least 3 years with a minimum of 2 years of follow-up. For patients with a right or left coronary artery originating from the pulmonary artery and coronary arteriovenous fistulas a registry is maintained.

Results

Primary outcomes are: (cardiac) death, myocardial ischaemia attributable to the ACAOS, re-intervention after surgery and intervention after initially conservative treatment. The influence of work-up examinations on treatment choice is also evaluated.

Conclusions

Structural evidence for the appropriate management of patients with coronary anomalies, especially (interarterial) ACAOS, is lacking. By means of a structured care pathway in a multicentre setting, we aim to provide an evidence-based strategy for the diagnostic evaluation and treatment of this patient group.

Supplementary Information

The online version of this article (10.1007/s12471-021-01556-9) contains supplementary material, which is available to authorized users.

P1797Prevalence of coronary anomalies in tetralogy of Fallot and its clinical implications, a meta-analysis

Background

In literature, anomalous coronary arteries from the opposite sinus of Valsalva or opposite coronary artery (ACAOS) are reported between 2% to 39% of patients with Tetralogy of Fallot (TOF). Knowledge of coronary anatomy prior to corrective surgery is vital to avoid damage to vessels crossing the right ventricular outflow tract (RVOT). The current range of reported prevalences is broad and a general overview comparing current knowledge on anomalous coronary arteries in TOF is lacking to date.

Purpose

In this meta-analysis, we aim to provide a detailed overview of current knowledge on prevalence of coronary anomalies in TOF and discuss the implications for patient management.

Methods

PubMed, Embase and Web of Science were searched for articles on TOF and coronary anomalies. Analysis was done using Revman 5.3 (Cochrane Community, London). The primary analysis focused on the origin and proximal course of the right and left coronary arteries. Also, the prevalences of large conus arteries and coronary arteriovenous fistulas were calculated.

Results

Twenty-nine studies, comprising 6977 patients all together, were included for primary meta-analysis of ACAOS. 6% of TOF patients have an ACAOS. Of these anomalous vessels, 72% crosses the RVOT. 6% of patients have a large conus artery and 4% a coronary arteriovenous fistula. Other incidentally reported coronary anomalies in TOF include a left or right coronary artery originating from the pulmonary artery, an accessory left anterior descending artery, hypoplasia of the entire coronary tree and anastomoses between coronary and bronchial arteries. CT-angiography is the imaging modality of preference because of its high spatial resolution. Transthoracic echocardiography can be used in younger children as well for discerning the coronary anatomy. Most surgical approaches can be adapted to an anomalous coronary artery coursing over the RVOT.

Overall prevalence of ACAOS in TOF

Conclusions

Coronary anomalies have a high prevalence in TOF. An ACAOS occurs in 6%, large conus arteries exist in 6% and coronary arteriovenous fistulas in 4% of cases. A substantial part crosses the RVOT. This has to be taken into account during surgery.

Ventricular assist device implantation in patients with a failing systemic right ventricle: a call to expand current practice

Ventricular assist device (VAD) implantation is an established treatment modality for patients with end-stage heart failure, and improves symptoms and survival. In the Netherlands, it is not yet routinely considered in patients with congenital heart disease and failing systemic right ventricle (SRV). Recently, a VAD was implanted in 2 SRV patients, one who underwent a Mustard procedure during infancy for transposition of the great arteries (male, 47 years old) and one with a congenitally corrected transposition of the great arteries (male, 54 years old). The first patient is doing well >1 year after implantation; the second patient will be discharged home soon. These examples and other reports demonstrate the feasibility of adopting VAD implantation into routine care for SRV failure. In conclusion, patients with SRV failure may be suitable candidates for VAD implantation: they are relatively young, usually have a preserved subpulmonary left ventricular function, and their specific anatomical and physiological characteristics often make them unsuitable for cardiac transplantation. Therefore it is important to recognise the possibility of VAD implantation early in the process of SRV failure, and to timely refer these patients to a heart failure clinic with experience in VAD implantation in this group of patients for optimisation, screening, and implantation.

Tailored circulatory intervention in adults with pulmonary hypertension due to congenital heart disease

BACKGROUND

Adults with pulmonary hypertension associated with congenital heart disease (PH-CHD) often have residual shunts. Invasive interventions aim to optimise pulmonary flow and prevent right ventricular failure. However, eligibility for procedures strongly depends on the adaptation potential of the pulmonary vasculature and right ventricle to resultant circulatory changes. Current guidelines are not sufficiently applicable to individual patients, who exhibit great diversity and complexity in cardiac anomalies.

METHODS AND RESULTS

We present four complex adult PH-CHD patients with impaired pulmonary flow, including detailed graphics of the cardiopulmonary circulation. All these patients had an ambiguous indication for shunt intervention. Our local multidisciplinary Grown-Ups with Congenital Heart Disease team reached consensus regarding a patient-tailored invasive treatment strategy, adjacent to relevant guidelines. Interventions improved pulmonary haemodynamics and short-term clinical functioning in all cases.

CONCLUSIONS

Individual evaluation of disease characteristics is mandatory for tailored interventional treatment in PH-CHD patients, adjacent to relevant guidelines. Both strict registration of cases and multidisciplinary and multicentre collaboration are essential in the quest for optimal therapy in this patient population.

Ventilator-associated pneumonia in children after cardiac surgery in The Netherlands

PURPOSE

We conducted a retrospective cohort study in an academic tertiary care center to characterize ventilator-associated pneumonia (VAP) in pediatric patients after cardiac surgery in The Netherlands.

METHODS

All patients following cardiac surgery and mechanically ventilated for ≥24 h were included. The primary outcome was development of VAP. Secondary outcomes were duration of mechanical ventilation and length of ICU stay.

RESULTS

A total of 125 patients were enrolled. Their mean age was 16.5 months. The rate of VAP was 17.1/1,000 mechanical ventilation days. Frequently found organisms were Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus and Pseudomonas aeruginosa. Patients with VAP had longer duration of ventilation and longer ICU stay. Risk factors associated with the development of VAP were a PRISM III score of ≥10 and transfusion of fresh frozen plasma.

CONCLUSION

The mean VAP rate in this population is higher than that reported in general pediatric ICU populations. Children with VAP had a prolonged need for mechanical ventilation and a longer ICU stay.

[Percutaneous implantation of a pulmonary valve in 3 children with surgically corrected cardiac anomalies]

An 11-year-old girl, a 15-year-old boy and a 12-year-old girl all underwent percutaneous implantation of a Melody pulmonary valve prosthesis to replace a stenotic and insufficient homograft in the pulmonary artery. Preoperatively, 2 of the children suffered from fatigue and dyspnoea on exertion The homografts had been implanted between the ages of 1-2, to establish surgical continuity between the right ventricle and the pulmonary artery. The anomalies were tetralogy of Fallot, pulmonary atresia with intact ventricular septum and pulmonary atresia with a ventricular septum defect. Percutaneous pulmonary valve replacement was successful in all 3 patients. After implantation, right ventricular pressure decreased to 30% of systemic pressure and regurgitation was not observed. All patients were discharged in a good condition on the day after the implantation. Percutaneous pulmonary valve replacement is a promising technique with good short-term results. In selected patients this percutaneous technique can substitute or postpone the surgical replacement ofa stenotic or insufficient homograft.

Right ventricular hypertrophy and diastolic dysfunction in arterial switch patients without pulmonary artery stenosis

OBJECTIVE

To assess pulmonary flow dynamics and right ventricular (RV) function in patients without significant anatomical narrowing of the pulmonary arteries late after the arterial switch operation (ASO) by using magnetic resonance imaging (MRI).

METHODS

17 patients (mean (SD), 16.5 (3.6) years after ASO) and 17 matched healthy subjects were included. MRI was used to assess flow across the pulmonary trunk, RV systolic and diastolic function, and RV mass.

RESULTS

Increased peak flow velocity (>1.5 m/s) was found across the pulmonary trunk in 14 of 17 patients. Increased RV mass was found in ASO patients: 14.9 (3.4) vs 10.0 (2.6) g/m2 in normal subjects (p<0.01). Delayed RV relaxation was found after ASO: mean tricuspid valve E/A peak flow velocity ratio = 1.60 (0.96) vs 1.92 (0.61) in normal subjects (p = 0.03), and E-deceleration gradients = -1.69 (0.73) vs -2.66 (0.96) (p<0.01). After ASO, RV mass correlated with pulmonary trunk peak flow velocity (r = 0.49, p<0.01) and tricuspid valve E-deceleration gradients (r = 0.35, p = 0.04). RV systolic function was well preserved in patients (ejection fraction = 53 (7)% vs 52 (8)% in normal subjects, p = 0.72).

CONCLUSIONS

Increased peak flow velocity in the pulmonary trunk was often observed late after ASO, even in the absence of significant pulmonary artery stenosis. Haemodynamic consequences were RV hypertrophy and RV relaxation abnormalities as early markers of disease, while systolic RV function was well preserved.

[Favourable results with surgical treatment in 43 children with hypoplastic left-heart syndrome or similar disorders, 1999-2005]

OBJECTIVE

To describe the results of surgical treatment of hypoplastic left-heart syndrome (HLHS) and HLHS-like disorders in the Amsterdam-Leiden Centre for Congenital Heart Disease, the Netherlands.

DESIGN

Retrospective, descriptive.

METHOD

Data were collected on 43 neonates with HLHS or similar disorders who underwent surgical treatment between December 1999 and December 2005. HLHS was present in 37 patients and 6 had disorders similar to HLHS (unbalanced atrioventricular septal defect, truncus arteriosus with hypoplastic left ventricle, double inlet left ventricle). Surgery was performed in 3 steps: Norwood operation shortly after birth (n = 43), bidirectional cavopulmonary anastomosis a few months later (n = 30) and total cavopulmonary connection at the age of 2-3 years (n = 10). During the Norwood operation, the first 21 patients received a modified Blalock shunt (between the right brachiocephalic artery and pulmonary artery), whereas the following 22 patients received a Sano shunt (between the right ventricle and pulmonary artery).

RESULTS

Of the 43 patients, 11 died: 7 within 30 days of the first operation, 2 between the first and second operation, and 2 between the second and third operation. Actuarial survival for the entire group is 74% (32/43). The mortality rate was lower with the Sano shunt (9%; 2/22) than with the modified Blalock shunt (43%; 9/21). Catheter interventions were necessary in 10 patients: 6 had balloon dilatation of the distal aortic arch and 4 had balloon dilatation/stent placement for narrowed pulmonary arteries. With a median follow-up of 22 months (range: 1-75), 2 patients had marked neurological side effects. All 32 surviving patients were in good clinical condition.

Surgical repair of aortopulmonary window: thirty-seven years of experience

An aortopulmonary window (APW) is a communication between the ascending aorta and the pulmonary trunk in the presence of two separate semilunar valves. In order to increase our understanding about the surgical management of this rare lesion and its long-term results, we describe our experience over a 37-year period. Between 1968 and 2005, 18 patients were diagnosed with APW. Seventeen underwent surgical correction. Age at operation ranged from 22 days to 22 years (median, 0.20 years). Follow-up ranged from 2 weeks to 28.6 years (median, 11.0 years). Surgical closure was achieved using a single patch in 7 patients (41.2%) double patch in 4 (23.5%), primary closure in 3 (17.6%), clip in 2 (11.8%), and ligation in 1 (5.9%). Complex APW was present in 8 patients (44.4%). One patient was treated nonsurgically. There were no early or late deaths after surgery. Both primary closure and patch closure gave excellent long-term results. Sporadic postoperative complications were only associated with complex lesions. One patient who was treated conservatively died (of pulmonary hypertension) 21 years after diagnosis. Repair of APW is ideally performed in the first months of life, before irreversible PHT has developed. Various surgical repair techniques in this series of patients gave excellent short-term and long-term results, without significant hemodynamic sequelae.

[Mechanical circulatory support after paediatric cardiac surgery]

When circulatory failure occurs after paediatric cardiac surgery despite conventional therapy (inotropic medication, optimising pre- and afterload) mechanical assist devices can be used. Assist devices can be categorised in different ways: according to the type of pump used (centrifugal, axial flow, or pneumatic), according to univentricular or biventricular support and in relation to the presence of an oxygenator. Paediatric devices are non-implantable. Extra-corporeal membrane oxygenation (ECMO) consists of a roller pump and a membrane oxygenator and is a relatively simple means of biventricular cardiac support while respiratory support is provided at the same time. All other devices lack the oxygenator and thus provide only circulatory support. The main disadvantage of ECMO is that it can be used for a maximum of several weeks while modern pneumatic assist devices (MEDOS, Berlin Heart) can be used for several months. Thromboembolic events, bleeding and sepsis are the main complications of all assist devices. The use of circulatory assist devices can increase the chances of survival when severe cardio(pulmonary) failure occurs following surgical correction of congenital heart defects.

High mortality rate after extubation failure after pediatric cardiac surgery

The objective of this study was to evaluate the different causes of extubation failure and the consequent mortality rates in a pediatric population after cardiac surgery. We studied 184 consecutive patients with a median age of 9 months (range, 0-165). In 158 patients, extubation was successful (group A). Nine patients were reintubated for upper airway obstruction and finally extubated successfully (group B). Seventeen patients were reintubated for cardiorespiratory failure, finally leading to death in 11 of 17 patients (65%) (group C). Group B patients were younger and had a longer intubation period compared to group A patients. Group C patients had more reoperations (30% vs 4% in group A patients, p < 0.001), a lower PaO2 on admission at the intensive care unit as well as just prior to extubation, a lower base deficit before extubation, and needed more inotropic support during their stay in the intensive care unit. We conclude that extubation failure after pediatric cardiac surgery due to cardiorespiratory failure is a bad prognostic sign. Patients with high inotropic support and a low PaO2 prior to extubation are especially at risk and probably need careful evaluation before final extubation.

An unexpected cause of a recurrent cerebral hemorrhage

A 4-year-old previously healthy boy presented with a non-traumatic right parietal hemorrhage. A second life-threatening left cerebral hemorrhage occurred three weeks later and was decompressed with a craniotomy. Transthoracic echocardiography revealed a hypermobile elongated tumor of the mitral valve. The cardiac tumor was successfully resected three weeks after the craniotomy. Histological examination of the cardiac tumor revealed a papillary lesion of spindle cells with smooth muscle cell differentiation. In view of the histological findings and the clinical symptoms, a cellular myofibroblastic tumor was considered the most likely diagnosis in our patient. Although a cardiac tumor is a rare cause of a cerebral hemorrhage, a cardiac evaluation is recommended in pediatric patients with a cerebral hemorrhage of unknown etiology.

Effect of three different anaesthetic agents on the postoperative production of cardiac troponin T in paediatric cardiac surgery

BACKGROUND

Paediatric cardiac surgery is associated with some degree of myocardial injury. Ischaemic preconditioning (IP) has been investigated widely in the adult population. Volatile agents have been shown to simulate IP providing extra protection to the myocardium during adult cardiopulmonary bypass (CPB) while propofol seems to act through different mechanisms. IP has not been investigated in the paediatric population to the same extent. Cardiac troponin T (cTnT) is a reliable marker of myocardial injury in neonates and children. We have investigated the relationship between three anaesthetic agents, midazolam, propofol, and sevoflurane, and postoperative production of cTnT.

METHODS

Ninety patients undergoing repair of congenital heart defect with CPB were investigated in a prospective randomized study. cTnT was measured four times during the first 24 h following admission to the paediatric intensive care unit. Other variables measured included arterial blood gases, lactate, fluid balance, use of inotropic drugs, PaO2/FiO2 ratio and ventilator hours.

RESULTS

cTnT was elevated in all three groups throughout the study period. The differences between the three groups were not statistically significant. Eight hours after admission to the intensive care unit cTnT concentrations tended to be higher in the midazolam group [mean (95% confidence intervals)]; 2.7 (1.9-3.5) ng ml(-1). Patients receiving a propofol-based anaesthesia had similar concentrations 2.6 (1.7-3.5) ng ml(-1) while those receiving sevoflurane tended to have a lower cTnT production 1.7 (1.3-2.2) ng ml(-1).

CONCLUSIONS

Midazolam, propofol, and sevoflurane appear to provide equal myocardial protection in paediatric cardiac surgery when using cTnT as a marker of myocardial damage.

[Complete atrioventricular septal defect in children with Down's syndrome: good results of surgical correction at younger and younger ages]

OBJECTIVE

To evaluate the results of cardiosurgical treatment of children with Down's syndrome and a complete atrioventricular septal defect (cAVSD).

DESIGN

Retrospective.

METHOD

Data were collected from the records of all patients with Down's syndrome who had been subjected to primary corrective surgery for cAVSD in the period 1980-2003 in Leiden, The Netherlands. Exclusion criteria were: concomitant tetralogy of Fallot or interruption of the aortic arch and palliative banding of the pulmonary artery. Children with an abnormal shape of the ventricle making it impossible to correct biventricularly were not considered in the study. Data on mortality >30 days after the operation and on repeated surgery were included in the analysis if the duration of follow-up was at least 5 years.

RESULTS

The group comprised 148 children: 75 girls and 73 boys. The median age at time of surgery was 20 weeks (range: 6 weeks to 3.7 years) and showed a statistically significant decrease during the period under investigation. Of 4 children lost to clinical follow-up actual data could be obtained. The median duration offollow-up was 6 years and 7 months (range: 38 days to 23 years and 11 months). 28 children (19%) died. The mortality within 30 days after the operation decreased from 0-38% in the period 1980-1989 via 0-30% in the period 1990-1999 to 0% in 2000-2003. The percentage ofreoperations related to the correction ofcAVSD (14%; 14/98) did not seem to increase. Of the correction-related reoperations, 14% (2/14) were followed by a second reoperation. Conclusion. In the period 1980-2003, children with Down's syndrome and a cAVSD were corrected surgically at a younger and younger age. The early mortality decreased to 0% in the years 2000-2003. Echocardiography in the first weeks of life for all children with Down's syndrome makes it possible to diagnose those with a cAVSD early enough for surgical repair.

Gut permeability in paediatric cardiac surgery

BACKGROUND

Intestinal mucosal ischaemia can occur in infants and children during and after cardiac surgery. Severe decreases in mucosal perfusion may cause complications such as necrotizing enterocolitis and postoperative mortality. We investigated gut permeability in paediatric patients undergoing cardiac surgery using the dual sugar permeability test and absorption of two other saccharides.

METHODS

Thirty-four patients undergoing palliative or corrective surgical procedures with and without cardiopulmonary bypass were investigated. Intestinal permeability was measured using 3-O-methyl-D-glucose, D-xylose, L-rhamnose and lactulose, given orally after induction of anaesthesia and 12 and 24 h later.

RESULTS

Lactulose/rhamnose ratios were raised from the outset [median 0.39 (confidence interval 0.07-1.8 for patients undergoing operations without cardiopulmonary bypass and 0.30 (0.02-2.6) with cardiopulmonary bypass]. The highest lactulose/rhamnose ratios were recorded 12 h after surgery 0.32 (0.07-6.9), when cardiopulmonary bypass was used. This is approximately seven times the value expected in healthy children. There was an improvement in patients not undergoing cardiopulmonary bypass: 0.22 (0.03-0.85) 12 h and 0.11 (0-0.48) 24 h after induction of anaesthesia. Patients undergoing repair of aortic coarctation showed the fastest recovery: 0.09 (0.03-0.31) 12 h and 0.07 (0.04-0.35) 24 h after induction of anaesthesia.

CONCLUSIONS

Patients with congenital heart defects have abnormal gut permeability when compared with healthy children of similar age. Cardiopulmonary bypass seems to affect the intestinal barrier morphologically (lactulose and rhamnose absorption) and functionally (3-O-methyl-D-glucose and D-xylose absorption).

Decellularization of rat aortic valve allografts reduces leaflet destruction and extracellular matrix remodeling

OBJECTIVES

Decellularization of aortic valve allografts in advance of transplantation is a promising approach to overcome immune-induced early graft failure. In this study the effects of in vitro cell extraction on extracellular matrix molecules and in vivo remodeling of decellularized aortic valves were investigated in a heterotopic aortic valve rat implantation model.

METHODS

Rat aortic valve conduits were decellularized by a 2-step detergent-enzymatic extraction method involving sodium dodecyl sulfate in combination with RNase and DNase. Cellular and acellular allogeneic (2x, n = 4) and syngeneic valve grafts (2x, n = 3) were grafted infrarenally into the descending aorta for 21 days. Immunohistochemical techniques were used to study extracellular matrix constitution (elastin, collagen, fibronectin, and chondroitin sulfate) and cellular infiltration.

RESULTS

The decellularization procedure resulted in a complete loss of all cellular structures from the entire valve conduit with minimal damage to the extracellular matrix. All transplanted cellular allografts became deformed, swollen, and acellular with major changes in extracellular matrix structure. The transplanted decellularized allografts, however, retained normal preserved valve leaflets comparable to transplanted cellular and acellular syngeneic grafts. With the exception of cellular syngeneic grafts, all other grafts showed retrovalvular thrombi.

CONCLUSIONS

Damage to the valves caused by decellularization technique is much less than the damage caused by the recipient's immune response. In vitro removal of viable cells in (cryopreserved) homografts may decrease graft failure. Seeding with autologous or major histocompatibility complex-matched donor endothelial cells will be necessary to diminish damage induced by an absent blood-tissue barrier.

ECG predictors of ventricular arrhythmias and biventricular size and wall mass in tetralogy of Fallot with pulmonary regurgitation

BACKGROUND

In patients with the tetralogy of Fallot, QRS prolongation predicts malignant ventricular arrhythmias. QRS prolongation may result from right ventricular dilatation. The relation of ECG markers to biventricular wall mass and volumes has not been assessed.

OBJECTIVE

To investigate the relations of surface ECG markers of depolarisation and repolarisation to right and left ventricular volume and biventricular wall mass.

METHODS

37 Fallot patients (mean (SD) age 17 (9) years) were studied 14 (8) years after surgical repair; 34 had important pulmonary regurgitation. Left and right ventricular size was assessed from tomographic magnetic resonance imaging (MRI), and the amount of pulmonary regurgitation by velocity mapping MRI. QT, QRS, and JT duration and interlead dispersion markers were derived from a standard 12 lead ECG.

RESULTS

Mean QRS duration was significantly prolonged (133 (31) v 91 (11) ms in controls), as were dispersion of QRS (36 (17) v 20 (6) ms), QT interval (87 (48) v 42 (20) ms), and JT interval (93 (48) v 42 (19) ms). Biventricular volumes were increased (right ventricular end diastolic volume, 129 (41) v 70 (9) ml/m(2); left ventricular end diastolic volume, 83 (16) v 69 (10) ml/m(2)), as was right ventricular wall mass (24 (7) v 17 (2) g/m(2)). QRS duration correlated best with right ventricular mass (r = 0.55, p < 0.01).

CONCLUSIONS

In patients operated on for tetralogy of Fallot and with pulmonary regurgitation, ECG predictors of ventricular arrhythmias are influenced by several mechanical factors that may occur simultaneously. These include increased right ventricular volume, but also increases in left ventricular volume and in right and left ventricular wall mass.

Report of the Dutch experience with the Ross procedure in 343 patients

OBJECTIVE

Limited information is available on outcome after autograft aortic valve replacement, in particular with respect to the durability of the autograft and of the allograft used to reconstruct the right ventricular outflow tract. A retrospective follow-up study of all patients who underwent a Ross procedure in the Netherlands since 1988 was done to obtain an overview of the Dutch experience with this procedure.

METHODS

From 1988 to January 2000, 348 Ross procedures were performed in nine centers in the Netherlands. Pre-operative, peri-operative and follow-up data from 343 patients in seven centers (99% of all Dutch autograft patients) were collected and analyzed.

RESULTS

Mean patient age was 26 years (SD 14, range 0-58) and male/female ratio was 2.1. Bicuspid valve or other congenital heart valve disease was the most common indication for operation. The root replacement technique was used in 95% of patients and concomitant procedures were done in 12%. Hospital mortality was 2.6% (N=9). Mean follow-up was 4 years (median 3.8, SD 2.8, range 0-12.5). Overall cumulative survival was 96% at 1 year (95% confidence interval (CI) 94-98%) and 94% at 5 and 7 post-operative years, respectively (95% CI 91-97%). At last follow-up, 87% of the surviving patients was in New York Heart Association (NYHA) class I. Independent predictors of overall mortality were pre-operative NYHA class IV/V and longer perfusion time. Autograft reoperation had to be performed in 14 patients and reintervention on the pulmonary allograft in 10 patients. Freedom from any valve-related reintervention was 88% at 7 years (95% CI 81-94%).

CONCLUSIONS

The Dutch experience with the Ross procedure is favorable, with low operative mortality and good mid-term results. Although both the autograft in aortic position and the allograft in the right ventricular outflow tract have a limited durability, this has not yet resulted in considerable reoperation rates and associated morbidity and mortality.

Repair of aorto-right ventricular tunnel with pulmonary stenosis and an anomalous origin of the left coronary artery

A 5-month-old infant with aorto-right ventricular tunnel, pulmonary stenosis and a sole supply of the left coronary artery from the tunnel underwent closure of the ventricular end of the tunnel, subsequent to balloon pulmonary valvuloplasty. Care was taken not to obstruct the aortic end of the tunnel in order to maintain the left coronary artery perfusion.

Prime solutions for cardiopulmonary bypass in neonates: antioxidant capacity of prime based on albumin or fresh frozen plasma

OBJECTIVE

Oxidative damage and inflammation are believed to play an important role in postoperative complications after cardiopulmonary bypass. During bypass, a prime solution with a high antioxidant capacity may reduce the oxidative damage and inflammation. We investigated total antioxidant capacity and individual scavengers during the preparation of 2 different prime solutions.

METHODS

The prime solutions were prepared with either pasteurized human albumin or fresh frozen plasma. The total antioxidant capacity was measured with the total radical antioxidant parameter assay and with the ferric-reducing ability of plasma assay. The individual scavengers vitamin C, sulfhydryl groups, uric acid, and total protein were measured before, during, and after the prime preparation. Malondialdehyde was measured as a parameter for lipid peroxidation.

RESULTS

Neither prime solution showed a total radical antioxidant parameter value. The ferric-reducing ability of plasma value of prime solutions was lower than that of undiluted human albumin or fresh frozen plasma. Addition of mannitol did not increase the ferric-reducing ability of plasma value. Vitamin C was only found in the fresh frozen plasma prime. Both prime solutions contained sulfhydryl groups and uric acid in low concentrations. During ultrafiltration, low-molecular-weight antioxidants were lost into the ultrafiltrate.

CONCLUSIONS

We showed that prime solutions based on either albumin or fresh frozen plasma had very low antioxidant capacity and that ultrafiltration of the prime solution further lowers this capacity. A prime solution with a low antioxidant capacity may increase oxidative stress in neonates undergoing cardiopulmonary bypass.

Aortic valve replacement in patients with aortic valve stenosis improves myocardial metabolism and diastolic function

PURPOSE

To evaluate whether functional and metabolic changes recover after aortic valve replacement (AVR).

MATERIALS AND METHODS

Eighteen men with aortic valve stenosis (mean pressure gradient +/- SD, 79.9 mm Hg +/- 15.1) underwent magnetic resonance (MR) imaging and phosphorus 31 MR spectroscopy. In nine patients who underwent AVR, MR imaging and spectroscopy were repeated 40 weeks +/- 12 after AVR. Ten age-matched healthy men were control subjects.

RESULTS

Before AVR, the myocardial phosphocreatine (PCr)-to-adenosine triphosphate (ATP) ratio in the 18 patients was 1.24 +/- 0.17 and 1.43 +/- 0.14 in the control group (P <.01). In nine patients who underwent follow-up MR spectroscopy, the ratio increased from 1.28 +/- 0.17 to 1.47 +/- 0.14 (P <.05) following AVR. Before AVR, early acceleration peak corrected for cardiac output was (0.043 +/- 0.008) x 10(-3) sec(-1) in patients and (0.081 +/- 0.033) x 10(-3) sec(-1) in the control group (P <.05). After 40 weeks +/- 12, the mean early acceleration peak corrected for cardiac output in the nine patients increased significantly to (0.055 +/- 0.006) x 10(-3) sec(-1) (P <.05), although it was still significantly lower than that of the control group (P <.05). Before AVR, a significant correlation was found between the myocardial PCr-ATP ratio and left ventricular diastolic function (n = 18; P <.05).

CONCLUSION

Severe aortic valve stenosis leads to a decreased myocardial PCr-ATP ratio and impairment of left ventricular diastolic function; following AVR, the ratio normalizes completely, whereas function improves significantly. There is an association between altered myocardial high-energy phosphate metabolism and impaired left ventricular diastolic function.

Acute renal insufficiency and renal replacement therapy after pediatric cardiopulmonary bypass surgery

The aim of the study was to investigate renal function and renal replacement therapy after cardiopulmonary bypass surgery in children. Patient characteristics (sex, age, diagnosis), operation type, and death were listed. The study was performed retrospectively using serum creatinine level before, and peak values after, cardiopulmonary bypass surgery for assessment of renal function. Of the children on renal replacement therapy, indication, efficacy, and complications were recorded. In a 5-year period, 1075 children had cardiopulmonary bypass surgery at the Department of Cardiothoracic Surgery at Leiden University Medical Center and Academic Medical Center of Amsterdam. One-hundred eighty (17%) patients developed acute renal insufficiency. Twenty-five (2.3%) patients required renal replacement therapy. Peritoneal dialysis is a safe and effective treatment for children after cardiopulmonary bypass surgery. However, 15 (60%) of 25 children on renal replacement therapy died of nonrenal causes. In 9 out of 10 surviving children, renal function was normal at time of discharge from hospital. Acute renal insufficiency is a frequent complication after open-heart surgery, although renal replacement therapy was infrequently necessary. Peritoneal dialysis is a safe and effective therapeutic measure for children after cardiac bypass surgery.

Pulmonary valve insertion late after repair of Fallot's tetralogy

OBJECTIVES

To analyze the results of pulmonary valve insertion late after initial repair of Fallot's tetralogy. Pulmonary insufficiency (PI) after correction of Fallot's tetralogy is usually well tolerated in the short term, but is associated with symptomatic right ventricular dilatation and an increased risk of ventricular arrhythmias over longer periods of time.

METHODS

From 1993 to July 2000, 51 patients were reoperated for PI at a mean age of 25.7+/-11.9 years. The mean age at initial repair was 6.4+/-7.2 years. Patients with a conduit inserted at initial operation, with absent pulmonary valve syndrome or with a more than moderate ventricular septal defect at reoperation were excluded from the study. A cryopreserved pulmonary (96%) or aortic (4%) homograft was implanted in the orthotopic position with the use of cardiopulmonary bypass 19.3+/-9.1 years (2.7-40.3 years) after initial correction. Preoperative symptoms (New York Heart Association, NYHA class), degree of PI (echo-Doppler, MRI), right ventricular dimensions (MRI) and QRS duration were compared to findings at last follow-up.

RESULTS

Follow-up is complete and had a mean duration of 1.7+/-1.4 years. Hospital mortality was 2%. No serious morbidity occurred. Severe PI was present preoperatively in all patients. At last follow-up echo-Doppler studies showed PI to be absent or trivial in 96% and mild in 4% of patients. In 13 patients MRI studies were performed both pre- and postoperatively: in this group PI was reduced from a mean of 48 to 4%. After 6 months NYHA capacity class had improved significantly from 2.3+/-0.6 to 1.4+/-0.5. After 1 year end-diastolic and end-systolic right ventricular volumes were reduced significantly. Right ventricular ejection fraction and QRS duration remained unchanged.

CONCLUSIONS

PI late after correction of Fallot's tetralogy may lead to serious symptomatic right ventricle dilatation. After pulmonary homograft insertion right ventricular dimensions decrease rapidly and functional improvement is observed in almost all patients.

Implantation of cardioverter device in young children: the perirenal approach

Placement of Implantable cardioverter devices in young children is complicated because of the relatively large size and heavy weight of these devices. A technique is described where the device is implanted in the left perirenal space while an endovascular lead is used instead of an epicardial patch electrode.

Outcome and follow-up of aortic valve replacement with the freestyle stentless bioprosthesis

BACKGROUND

The aim of this study was to determine the morbidity, mortality, and hemodynamics after implantation of the Freestyle stentless bioprosthesis in the aortic position.

METHODS

A total of 280 patients were operated on from June 1993 to July 1999 as part of a multicenter investigation. Factors influencing hospital mortality and long-term survival were assessed by logistic regression and Cox proportional hazards analysis. Patients were evaluated postoperatively at discharge, at 3 to 6 months, and yearly by clinical examination and color flow Doppler echocardiography.

RESULTS

Hospital mortality in this group was relatively high (9.6%). Logistic regression analysis showed that cross-clamp time, age, myocardial infarction, diabetes, left ventricular hypertrophy, coronary artery disease, New York Heart Association class III or IV and female gender were the independent predictive factors. According to the Kaplan-Meier method, the 4-year survival for hospital survivors was 94%. In the multivariate Cox proportional hazard analysis, only coronary artery disease proved to be prognostic. During follow-up, 11 patients developed paravalvular leakage due to prosthetic dehiscence at the side of the noncoronary cusp. Performance of the prosthesis as assessed by echocardiography was excellent. Mean gradient decreased significantly between discharge and follow-up at 3 to 6 months. At 1-year follow-up trivial regurgitation was found in 6 patients (3%) and mild regurgitation in 4 (2%). Regurgitation did not increase with time. The effective orifice area increased significantly from discharge to follow-up at 3 to 6 months.

CONCLUSIONS

Hospital mortality after implantation of a stentless bioprosthesis was higher compared to conventional prosthesis. A high incidence of prosthesis dehiscence at the proximal suture line was found, which was probably due to technique. Hemodynamic performance up to 3 years showed low transvalvular gradients. There is echocardiographic evidence for reduction of left ventricular hypertrophy and improvement of left ventricular function.

Remodeling of the porcine pulmonary autograft wall in the aortic position

OBJECTIVE

Dilatation and valve regurgitation are disturbing sequelae of the pulmonary root functioning at systemic pressures. We tried to characterize the histologic mode of adaptation of the neoaortic wall.

METHODS

We compared routine histologic studies, immunohistochemical staining, and computer-assisted morphometric analysis of aortic, pulmonary autograft, and native pulmonary wall specimens from pigs in which, as a newborn, a valveless pulmonary autograft had been implanted in the aorta.

RESULTS

Histologic examination of the pulmonary autograft revealed a viable, normally revascularized wall without degenerative phenomena. Smooth muscle cells were enlarged and rearranged. The characteristic "pulmonary" medial elastin lamellar structure was retained, which was confirmed by morphometry. Immunohistochemistry of the autograft revealed relatively strong staining of type III collagen and alpha smooth muscle actin, exclusive staining of basic fibroblast growth factor, and no staining of proliferation markers proliferating cell nuclear antigen and Ki67.

CONCLUSION

The developing pulmonary autograft in the aortic position becomes normally revascularized, lacks major degenerative phenomena, and retains its own typical pulmonary morphologic features. Remodeling is accomplished by increased extracellular matrix deposition with collagen as an important constituent. The marked expression of growth factors in the autograft suggests the persistence of increased metabolic activity.

Spin echo MRI in the evaluation of hearts with a double outlet right ventricle: usefulness and limitations

The surgical approach to a double outlet right ventricle (DORV) is dependent on the spatial relationship of the semilunar valves, outflow tracts and ventricular septal defect (VSD). The purpose of the study was to assess the value of MRI for the evaluation of cardiovascular anatomy in patients before and after surgery for DORV. Spin echo MRI was performed in 12 patients with DORV (eight preoperative and four postoperative patients). Thin-section MRI was performed in three orthogonal planes and selected angulated views were obtained. Conventional imaging by color Doppler echocardiography and cine-angiocardiography and surgical findings, when present, served as the reference standards. The results found that the spatial relationship between semilunar valves and VSD was accurately assessed by MRI in eight out of eight preoperative patients. In the four postoperative cases MRI depicted the morphology of both outflow tracts and provided adequate information on their patency. Of the eight preoperative patients, five have undergone corrective surgery and the MRI findings were confirmed. MRI provided additional information to conventional imaging preoperatively in three cases in which the VSD opened into the outlet portion of the DORV, without there being a direct relation to a semilunar valve. In two preoperative cases in which the VSD was directly committed to the aorta, conventional imaging was conclusive. MRI was unable to depict aberrant chordae tendineae in four out of four cases. We conclude that MRI provides accurate additional anatomic information in patients with DORV, which is helpful in presurgical planning as well as during follow-up. Spin echo MRI does not visualize aberrant chordae tendineae.

Dehiscence of the Freestyle stentless bioprosthesis

This study aimed to identify and characterize patients who developed prosthetic dehiscence after aortic valve replacement with the Freestyle Stentless bioprosthesis. Review of patients' records and preoperative echocardiogram was performed. Prosthetic dehiscence developed in 10 patients after 2.5 to 49 months (mean 19). Most patients were symptomatic at presentation. Nine patients were reoperated. Dehiscence was typically located at the inflow suture line beneath the noncoronary cusp. Four patients died. The cause of dehiscence is assumed to be related primarily to surgical technique.

Echocardiographic parameters of the freestyle stentless bioprosthesis in aortic position: the European experience

The objective of this study was to determine normal Doppler and 2-dimensional characteristics of the Freestyle stentless aortic bioprosthesis. The Freestyle aortic bioprosthesis is a new type of aortic xenograft, and experience is limited. We therefore determined the normal range of echocardiographic and Doppler examinations of this valve. Three hundred thirty-nine consecutive patients with a Freestyle aortic bioprosthesis underwent an echocardiographic and Doppler examination according to a common protocol. Investigations were done within 4 weeks after operation, after 3 to 6 months, and after 1, 2, and 3 years. With a valve size from 19 to 27 mm, mean gradients decreased from 7.9 +/- 5.1 mm Hg at discharge to 5.5 +/- 3. 8 mm Hg after 3 to 6 months (P <.001). Thereafter, gradients remained stable. Effective orifice area 1 year after implantation was 1.59 +/- 0.58 cm(2) for the 21-mm valves, 1.92 +/- 0.74 cm(2) for the 23-mm valves, 2.03 +/- 0.64 cm(2) for the 25-mm valves, and 2.52 +/- 0.72 cm(2) for the 27-mm valves (P <.001). The performance index, the ratio of the measured effective orifice area in the patient divided by the effective orifice area measured in vitro, increased from 67% +/- 20% at discharge to 82% +/- 29% after 1, 2, and 3 years. Performance index was especially very high in the smaller-sized valves. After implantation with the subcoronary technique or root-inclusion technique, small cavities could be seen between the native aortic root and the Freestyle valve. Doppler values were evaluated for the Freestyle stentless porcine bioprostheses in the aortic root. Gradients appear to be close to those measured in native valves over a time period of 3 years.

Brom's three-patch technique for repair of supravalvular aortic stenosis

OBJECTIVE

Case histories of all patients (n = 29) operated on for supravalvular aortic stenosis from 1962 to the present were reviewed to study different techniques and outcomes. The technique of symmetric aortoplasty with 3 patches (1 in each sinus) is described and compared with other methods.

METHODS

Case reports were reviewed and follow-up was completed by contacting the patient's (pediatric) cardiologist. We aimed for a last follow-up visit, including Doppler echocardiographic studies, in a period no more than 12 months earlier than December 1997. Supravalvular aortic stenosis was discrete in 25 and diffuse with involvement of the aortic arch and arch vessels in 4 patients. Additional anomalies were bicuspid aortic valve (n = 5), coarctation (n = 3), ascending aortic aneurysm (n = 1), mitral valve insufficiency (n = 2), pulmonary valvular stenosis (n = 1), and peripheral pulmonary artery stenosis (n = 2). Eleven patients had Williams syndrome and 1 patient had Noonan syndrome. Symmetric aortoplasty with 3 patches (1 in each sinus) was used in 13 patients, whereas other nonsymmetric methods (1, 2, or Y-shaped patches) were used in 16 patients. Mean follow-up was 10.5 years (range: 4 months-36 years).

RESULTS

All techniques adequately decreased the pressure gradient. Progression of preoperative aortic valve insufficiency or de novo regurgitation was not observed except in 1 patient in whom the patches inserted were too large.

CONCLUSIONS

No difference could be demonstrated in outcome for any surgical technique; however, reconstruction of the aortic root with autologous pericardial patches in each sinus after transection of the aorta has the advantage of symmetry while restoring the normal aortic root anatomy.

Dynamic obstruction, an unusual complication after aortic valve replacement with a stentless porcine valve

In the early nineties, the stentless porcine aortic bioprosthesis has been reintroduced successfully. Because of the limited experience, knowledge of clinical complications is limited. Therefore, we describe an unusual complication of dynamic obstruction after aortic valve replacement with a stentless porcine valve in a 70 year old man 18 months after implantation. We discuss the complications of stentless aortic prostheses known so far, describe operative techniques used and their characteristic two dimensional echocardiographic images.

Postsurgical course of patients with congenitally corrected transposition of the great arteries

Because congenitally corrected transposition is a rare congenital anomaly, little is known about the prognosis of patients with this syndrome. The present study evaluated the functional status and clinical course of 73 patients (42 male and 31 female) aged 10 days to 73 years. Follow-up was 1 week to 37 years (mean 12.7 years). Particular attention was paid to the systemic right ventricle, considering the current controversies about long-term right ventricular function. Survival of patients with this condition in general was significantly below normal. The total mortality rate was 11% (8 patients) after a mean follow-up of 12.7 years (range 10 days to 37 years). Mean age at death was 18.5 years (range 6 days to 63 years). The mean age of the survivors at latest follow-up was 21.4 years (range 4 months to 73 years). In most patients, right ventricular function deteriorated and tricuspid valve regurgitation increased, which began at a very young age. Patients without associated lesions developed complications at a higher age compared with the total group. Right ventricular and tricuspid valvular function deteriorated more frequently in patients following intracardiac operation (28% and 52%, respectively) compared with patients undergoing palliative intervention (16%) or no surgery at all (28%). We conclude that survival of patients with this condition is substantially reduced compared with the natural history of an age- and gender-matched general population. This could be explained by the associated cardiac defects, but also by the anatomic condition itself.

Tissue chimerism in human cryopreserved homograft valve explants demonstrated by in situ hybridization

BACKGROUND

The presence of viable cells may contribute to increased homograft valve durability. These cells may be of infiltrating recipient or persisting donor origin. In this study, in situ hybridization was used to assess the origin of cells in cryopreserved homograft valve explants.

METHODS

A total of 10 homografts with a donor-recipient gender mismatch were acquired from patients whose graft had been explanted at reoperation or at autopsy. The period of implantation varied from 14 days to 70 months. Frozen sections were made and alternately examined with hematoxylin and eosin staining and in situ hybridization. Male cells were distinguished from female using a biotinylated Y-chromosome-specific deoxyribonucleic acid probe.

RESULTS

No endothelial cells were found. Thirty percent of the leaflets showed large acellular zones and 30% were completely acellular. The homograft arterial wall was occupied by a vast majority of penetrating host fibroblasts in 80% of the studied specimens. Donor and recipient cells were coexistent in the wall in 60% of the studied specimens and in 50% of the leaflets. In 30% only host cells could be identified.

CONCLUSIONS

This finding of tissue chimerism may lead to new insights in homograft pathology. The technique of in situ hybridization may provide an indispensable contribution in further homograft research.

Short-term follow up of the Ross operation in children

BACKGROUND AND AIMS OF THE STUDY

Aortic valve disease in the pediatric population poses special problems to surgeons and cardiologists. The pulmonary autograft has proven to be a good alternative for aortic valve replacement and left ventricular outflow tract (LVOT) reconstruction in this special group.

METHODS

Forty-one children (mean age 10.0 +/- 4.8 (SD) years; range: 35 days to 18.8 years) underwent aortic root replacement with a pulmonary autograft between February 1994 and April 1998. Twenty-one patients (51%) had previous cardiac surgery; seven (17%) had balloon valvulotomy. Aortic root replacement was combined with other techniques for various disorders, including tunnel LVOT obstruction, ventricular septal defect (VSD)-aortic insufficiency complex, neoaortic insufficiency following arterial switch procedure, and subvalvular stenosis following correction of type B interruption of the aortic arch (IAA) with VSD (IAA-B/VSD).

RESULTS

The mean follow up was 1.7 +/- 1.0 years (range 44 days to 4.1 years). Total follow up time was 67.8 patient-years. Two patients, both after repair of interrupted aortic arch, died intraoperatively (4.9%). There was no late mortality. Two patients were reoperated on (5.1%), one for autograft insufficiency due to cuspal perforation and one for right ventricular outflow tract stenosis at the distal anastomosis. Thirty-eight patients (97%) are currently in NYHA class I; one child with a preoperatively poor left ventricular function did not improve and is in class II. At the latest echocardiographic follow up, neoaortic regurgitation was absent in 19% of patients, trivial in 69% and mild in 11%. Homograft insufficiency was absent in 64%, trivial in 31% and mild in 6%. All mean gradients for both autograft and homograft were < 15 mmHg.

CONCLUSIONS

The Ross operation can be performed with good results in infants and children with different forms of LVOT obstruction and aortic insufficiency, though aortic stenosis following IAA-B/VSD repair poses a surgically difficult problem.