Pediatr Radiol DOI 10.1007/s00247-015-3358-0
ORIGINAL ARTICLE
Repaired tetralogy of Fallot with coexisting unrepaired partial anomalous pulmonary venous connection is associated with diminished right ventricular ejection fraction and more severe right ventricular dilation Sherwin S. Chan 1 & Kevin K. Whitehead 2 & Timothy S. Kim 2 & Gregory L. Fu 2 & Marc S. Keller 3 & Mark A. Fogel 2 & Matthew A. Harris 2
Received: 7 December 2014 / Revised: 14 March 2015 / Accepted: 2 April 2015 # Springer-Verlag Berlin Heidelberg 2015
Abstract Background There is an established association between tetralogy of Fallot and partial anomalous pulmonary venous connections. This association is important because surgically repaired tetralogy patients have increased risk of right heart failure. We hypothesize that partial anomalous venous connections increase right ventricular volumes and worsen right ventricular failure. Materials and methods We reviewed cardiac MRI exams performed at a tertiary pediatric hospital from January 2005 to January 2014. We identified patients with repaired tetralogy and unrepaired partial anomalous pulmonary venous connection. We used age- and gender-matched repaired tetralogy patients without partial anomalous pulmonary venous connection as controls. We analyzed the MRI results and surgical course and performed comparative statistics to identify group differences. Results There were eight patients with repaired tetralogy and unrepaired partial anomalous pulmonary venous connection and 16 controls. In all cases, the partial anomalous pulmonary venous connection was not detected on preoperative
Electronic supplementary material The online version of this article (doi:10.1007/s00247-015-3358-0) contains supplementary material, which is available to authorized users. * Sherwin S. Chan [email protected] 1
Department of Radiology, Children’s Mercy Hospital and Clinics, 2401 Gillham Road, Kansas City, MO 64108, USA
2
Department of Cardiology, Children’s Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, PA, USA
3
Department of Radiology, Children’s Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, PA, USA
echocardiography. There were no significant differences in surgical course and body surface area between the two groups. Repaired tetralogy patients with unrepaired partial anomalous pulmonary venous connection showed significantly higher indexed right ventricular end diastolic volume (149±33 mL/ m2 vs. 118±30 mL/m2), right ventricle to left ventricle size ratios (3.1±1.3 vs. 1.9±0.5) and a higher incidence of reduced right ventricular ejection fraction compared to controls (3/8 vs. 0/16). Conclusion Repaired tetralogy of Fallot with unrepaired partial anomalous pulmonary venous connection is associated with reduced right ventricular ejection fraction and more significant right ventricular dilation. Keywords Adults . Children . Heart . Magnetic resonance imaging . Partial anomalous pulmonary venous connection . Right ventricle . Tetralogy of Fallot
Introduction Conotruncal abnormalities result from abnormal development of the portion of the heart that forms the aortic and pulmonary roots. The most common conotruncal abnormality is tetralogy of Fallot (TOF), which is characterized as right ventricle (RV) hypertrophy, RV outflow tract obstruction, overriding aorta and ventricular septal defect. A subset of patients with TOF will have associated pulmonic atresia. Patients with TOF are often now managed with a primary surgical repair or repair after an intervening palliating shunt [1–6]. Partial anomalous pulmonary venous connection (PAPVC) occurs when a portion of the pulmonary venous return is directed toward systemic venous return. PAPVC results in volume overload to the RV because a portion of the blood
Pediatr Radiol
directed to the pulmonary arteries returns to the right atrium, thus increasing the pulmonary to aortic blood flow ratio. There is an established association between TOF and anomalous pulmonary venous connections [7, 8]. These associations are rare, occurring in 0.6% of TOF patients in one case series from a prior era when cardiac MRI was not available [8]. This association of TOF and PAPVC was not thought to be clinically significant. The article that first noted this association recommended surgical repair of only total anomalous pulmonary venous connections and did not recommend surgical repair of the PAPVC in TOF patients based on functional status of the patients [8]. Patients after TOF repair often develop progressive moderate to severe RV volume overload due to significant pulmonary regurgitation [9–12]. This typically occurs more than 10 years after the repair [13]. Patients are followed routinely with echocardiography to qualitatively assess for pulmonary regurgitation, RV size and RV systolic function. Because RV size and systolic ejection are difficult to quantify with echocardiography, many practitioners refer patients to cardiac MRI for quantification of RV volumes and function (specifically, the RV end diastolic volume, the RV ejection fraction and the degree of pulmonary regurgitation) [14–16]. Based on the results of the MRI, patients are considered for pulmonary valve replacement surgery. The guidelines for valve replacement surgery are still being refined, but one commonly used criteria is RV end diastolic volume >150 ml/m2 [17]. We hypothesize that PAPVC can worsen the RV volume overload commonly seen in repaired TOF patients and result in diminished RV ejection fraction and increased RV volumes due to increased pulmonary flow from the left to right shunt.
Materials and methods Inclusion and exclusion criteria We performed a retrospective review of the radiology database from January 2005 to January 2014 to identify all cardiac MRI patients with TOF or TOF with pulmonary atresia who had surgical repair of their TOF. We identified patients with coexisting PAPVC using their MRI reports. For the main study, we excluded patients who only had a palliating shunt at the time of their MRI or had repaired PAPVC at the time of their MRI. For patients with multiple MRI studies, we used the first study as the one most representative of the patient. Since prior studies have shown that the degree of ventricular dysfunction after TOF repair depends on gender [18] and age [19], we chose gender and age (within 1 year for patients 18 years) matched controls with TOF or TOF with pulmonary atresia. Repaired TOF patients with aortopulmonary collaterals on their MRIs were excluded as control patients. We also analyzed MRI
exams of patients who had undergone repair of both their TOF and PAPVC to determine prevalence and to assess if PAPVC repairs resulted in improved numbers. For each patient and control, the surgical notes, clinical notes and MRI studies were reviewed to determine the type of TOF repair. This study was approved by the Children’s Hospital of Philadelphia institutional review board. MRI exam All MRI studies were performed on a 1.5-T system (Avanto; Siemens Healthcare, Erlangen, Germany). Volumetric analysis was performed on Argus software (Siemens Healthcare, Erlangen, Germany) using balanced steady-state free procession images in the short axis. The myocardium and cardiac cavity were traced on each of the short axis slices at enddiastole and end-systole. All contours were drawn by dedicated three-dimensional lab technicians and were all checked and modified by a pediatric cardiac imager (M.A.H., K.K.W., M.A.F. and M.S.K. with 10, 7, 15 and 15 years of cardiac MRI experience, respectively). The right ventricular contours included the right ventricular outflow to the level of the pulmonary valve plane. The volumetric measurements of the ventricles at end-diastole were indexed to body surface area resulting in indexed RV end-diastolic volume and indexed left ventricular end-diastolic volume. RV dysfunction was defined as RV ejection fraction
ORIGINAL ARTICLE
Repaired tetralogy of Fallot with coexisting unrepaired partial anomalous pulmonary venous connection is associated with diminished right ventricular ejection fraction and more severe right ventricular dilation Sherwin S. Chan 1 & Kevin K. Whitehead 2 & Timothy S. Kim 2 & Gregory L. Fu 2 & Marc S. Keller 3 & Mark A. Fogel 2 & Matthew A. Harris 2
Received: 7 December 2014 / Revised: 14 March 2015 / Accepted: 2 April 2015 # Springer-Verlag Berlin Heidelberg 2015
Abstract Background There is an established association between tetralogy of Fallot and partial anomalous pulmonary venous connections. This association is important because surgically repaired tetralogy patients have increased risk of right heart failure. We hypothesize that partial anomalous venous connections increase right ventricular volumes and worsen right ventricular failure. Materials and methods We reviewed cardiac MRI exams performed at a tertiary pediatric hospital from January 2005 to January 2014. We identified patients with repaired tetralogy and unrepaired partial anomalous pulmonary venous connection. We used age- and gender-matched repaired tetralogy patients without partial anomalous pulmonary venous connection as controls. We analyzed the MRI results and surgical course and performed comparative statistics to identify group differences. Results There were eight patients with repaired tetralogy and unrepaired partial anomalous pulmonary venous connection and 16 controls. In all cases, the partial anomalous pulmonary venous connection was not detected on preoperative
Electronic supplementary material The online version of this article (doi:10.1007/s00247-015-3358-0) contains supplementary material, which is available to authorized users. * Sherwin S. Chan [email protected] 1
Department of Radiology, Children’s Mercy Hospital and Clinics, 2401 Gillham Road, Kansas City, MO 64108, USA
2
Department of Cardiology, Children’s Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, PA, USA
3
Department of Radiology, Children’s Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, PA, USA
echocardiography. There were no significant differences in surgical course and body surface area between the two groups. Repaired tetralogy patients with unrepaired partial anomalous pulmonary venous connection showed significantly higher indexed right ventricular end diastolic volume (149±33 mL/ m2 vs. 118±30 mL/m2), right ventricle to left ventricle size ratios (3.1±1.3 vs. 1.9±0.5) and a higher incidence of reduced right ventricular ejection fraction compared to controls (3/8 vs. 0/16). Conclusion Repaired tetralogy of Fallot with unrepaired partial anomalous pulmonary venous connection is associated with reduced right ventricular ejection fraction and more significant right ventricular dilation. Keywords Adults . Children . Heart . Magnetic resonance imaging . Partial anomalous pulmonary venous connection . Right ventricle . Tetralogy of Fallot
Introduction Conotruncal abnormalities result from abnormal development of the portion of the heart that forms the aortic and pulmonary roots. The most common conotruncal abnormality is tetralogy of Fallot (TOF), which is characterized as right ventricle (RV) hypertrophy, RV outflow tract obstruction, overriding aorta and ventricular septal defect. A subset of patients with TOF will have associated pulmonic atresia. Patients with TOF are often now managed with a primary surgical repair or repair after an intervening palliating shunt [1–6]. Partial anomalous pulmonary venous connection (PAPVC) occurs when a portion of the pulmonary venous return is directed toward systemic venous return. PAPVC results in volume overload to the RV because a portion of the blood
Pediatr Radiol
directed to the pulmonary arteries returns to the right atrium, thus increasing the pulmonary to aortic blood flow ratio. There is an established association between TOF and anomalous pulmonary venous connections [7, 8]. These associations are rare, occurring in 0.6% of TOF patients in one case series from a prior era when cardiac MRI was not available [8]. This association of TOF and PAPVC was not thought to be clinically significant. The article that first noted this association recommended surgical repair of only total anomalous pulmonary venous connections and did not recommend surgical repair of the PAPVC in TOF patients based on functional status of the patients [8]. Patients after TOF repair often develop progressive moderate to severe RV volume overload due to significant pulmonary regurgitation [9–12]. This typically occurs more than 10 years after the repair [13]. Patients are followed routinely with echocardiography to qualitatively assess for pulmonary regurgitation, RV size and RV systolic function. Because RV size and systolic ejection are difficult to quantify with echocardiography, many practitioners refer patients to cardiac MRI for quantification of RV volumes and function (specifically, the RV end diastolic volume, the RV ejection fraction and the degree of pulmonary regurgitation) [14–16]. Based on the results of the MRI, patients are considered for pulmonary valve replacement surgery. The guidelines for valve replacement surgery are still being refined, but one commonly used criteria is RV end diastolic volume >150 ml/m2 [17]. We hypothesize that PAPVC can worsen the RV volume overload commonly seen in repaired TOF patients and result in diminished RV ejection fraction and increased RV volumes due to increased pulmonary flow from the left to right shunt.
Materials and methods Inclusion and exclusion criteria We performed a retrospective review of the radiology database from January 2005 to January 2014 to identify all cardiac MRI patients with TOF or TOF with pulmonary atresia who had surgical repair of their TOF. We identified patients with coexisting PAPVC using their MRI reports. For the main study, we excluded patients who only had a palliating shunt at the time of their MRI or had repaired PAPVC at the time of their MRI. For patients with multiple MRI studies, we used the first study as the one most representative of the patient. Since prior studies have shown that the degree of ventricular dysfunction after TOF repair depends on gender [18] and age [19], we chose gender and age (within 1 year for patients 18 years) matched controls with TOF or TOF with pulmonary atresia. Repaired TOF patients with aortopulmonary collaterals on their MRIs were excluded as control patients. We also analyzed MRI
exams of patients who had undergone repair of both their TOF and PAPVC to determine prevalence and to assess if PAPVC repairs resulted in improved numbers. For each patient and control, the surgical notes, clinical notes and MRI studies were reviewed to determine the type of TOF repair. This study was approved by the Children’s Hospital of Philadelphia institutional review board. MRI exam All MRI studies were performed on a 1.5-T system (Avanto; Siemens Healthcare, Erlangen, Germany). Volumetric analysis was performed on Argus software (Siemens Healthcare, Erlangen, Germany) using balanced steady-state free procession images in the short axis. The myocardium and cardiac cavity were traced on each of the short axis slices at enddiastole and end-systole. All contours were drawn by dedicated three-dimensional lab technicians and were all checked and modified by a pediatric cardiac imager (M.A.H., K.K.W., M.A.F. and M.S.K. with 10, 7, 15 and 15 years of cardiac MRI experience, respectively). The right ventricular contours included the right ventricular outflow to the level of the pulmonary valve plane. The volumetric measurements of the ventricles at end-diastole were indexed to body surface area resulting in indexed RV end-diastolic volume and indexed left ventricular end-diastolic volume. RV dysfunction was defined as RV ejection fraction
