R Yates

Great Ormond Street Hospital for Children NHS Foundation Trust, Londinium, England, United Kingdom

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Publications (30)126.17 Total impact

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    ABSTRACT: There is no consensus about optimal surgical technique for the repair of scimitar vein, an anomalous right pulmonary venous connection to the inferior vena cava. Our current experience with a direct anastomosis of the scimitar vein to the left atrium via sternotomy may be shared with other centres, but has not been widely published. Six consecutive patients (age 6 months to 17 years, mean 5 years) operated on in 2009-12 were retrospectively reviewed. Through median sternotomy and with cardiopulmonary bypass, the mobilized anomalous right pulmonary vein was brought through a large pericardial opening posterior to the right phrenic nerve and anastomosed onto the right side of the posterior left atrium with access via an existing or a surgically created atrial septal defect. Five patients had primary venous repair and one had a previous failed repair using an intra-atrial baffle. The median cardiopulmonary bypass and cross-clamp times were 88 and 38 min, respectively. The median ventilator time was 1 day and the median stay at the intensive care unit 3.5 days. There were no deaths within a median follow-up of 28 months (range 8-41 months), nor reoperations or instances of pulmonary venous obstruction. Anatomic repair of the scimitar vein based on reimplantation onto the left atrium via sternotomy is conceptually appealing. The surgery results in a safe and reliable repair in patients with a wide age spectrum. Durability needs on-going assessment in longer-term follow-up.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 11/2013; · 2.40 Impact Factor
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    ABSTRACT: Preoperative comorbidities (PCMs) are known risk factors for Norwood stage I (NW1). We tested the hypothesis that short-term bilateral pulmonary arterial banding (bPAB) before NW1 could improve the prognosis of these high-risk patients. From January 2006 to October 2011, 17 high-risk patients with hypoplastic left heart syndrome (defined as having ≥4 of the following PCMs: prolonged mechanical ventilation; older age; sepsis; necrotizing enterocolitis; hepatic, renal, or heart failure; coagulopathy; pulmonary edema; high inotropic requirements; anasarca; weight <2.5 kg; and cardiac arrest) were identified. In addition to conventional treatment of PCMs, they underwent bPAB before NW1. bPAB was undertaken with Silastic slings and secured with ligaclips to a luminal diameter of approximately 3.5 to 4.0 mm. The patency of the ductus arteriosus was maintained with prostaglandin. NW1 was performed using a modified, right Blalock-Taussig shunt at a median interval of 8 days after bPAB. The data from these patients were retrospectively reviewed, and the 30-day mortality and 1-year survival were compared with the hypoplastic left heart syndrome population who underwent primary NW1 with <3 PCMs in the same period. Of the bPAB patients, 5 (29.4%) died before NW1. All had ≥5 PCMs. Twelve patients (70.6%) survived to undergo NW1. One early death occurred after NW1 (8.3%). The 1-year survival rate for high-risk patients who underwent NW1 was 66.7%. The early mortality and 1-year survival for the 130 patients with <3 PCMs was 10% and 80%, respectively. Optimizing the balance between the pulmonary and systemic blood flow with a short period of bPAB and ductal patency can improve the perioperative conditions of high-risk patients before NW1. Those who survived bPAB and underwent NW1 had early mortality and 1-year survival comparable to the standard risk category, despite the severity of their initial condition. A rapid 2-stage NW1 strategy with bPAB and prostaglandin to maintain ductal patency can avoid the risks of suboptimal palliation and vascular injuries associated with hybrid procedures.
    The Journal of thoracic and cardiovascular surgery 11/2013; 146(5):1146-1152. · 3.41 Impact Factor
  • European heart journal cardiovascular Imaging. 04/2013;
  • Ultrasound in Obstetrics and Gynecology 10/2011; 38(S1). · 3.56 Impact Factor
  • Ultrasound in Obstetrics and Gynecology 10/2010; 36(S1):3. · 3.56 Impact Factor
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    ABSTRACT: Treatment of right ventricular outflow tract obstruction is possible with a bare metal stent (BMS), although this treatment causes pulmonary regurgitation. In this study, we assessed the acute physiological effects of BMS versus percutaneous pulmonary valve implantation (PPVI) using an x-ray/magnetic resonance hybrid laboratory. Fourteen consecutive children (median age, 12.9 years) with significant right ventricular outflow tract obstruction underwent BMS followed by PPVI. Magnetic resonance imaging (ventricular volumes and function and great vessel blood flow) and hemodynamic assessment (invasive pressure measurements) were performed before BMS, after BMS, and after PPVI; all were performed under general anesthesia in an x-ray/magnetic resonance hybrid laboratory. BMS significantly reduced the ratio of right ventricular to systemic pressure (0.75+/-0.17% versus 0.41+/-0.14%; P<0.001) with no further change after PPVI (0.42+/-0.11; P=1.0). However, BMS resulted in free pulmonary regurgitation (21.3+/-10.7% versus 41.4+/-7.5%; P<0.001), which was nearly abolished after PPVI (3.6+/-5.6%; P<0.001). Effective right ventricular stroke volume (right ventricular stroke volume minus pulmonary regurgitant volume) after BMS remained unchanged (33.8+/-7.3 versus 32.6+/-8.7 mL/m2; P=1.0) but was significantly increased after revalvulation with PPVI (41.0+/-8.0 mL/m2; P=0.004). These improvements after PPVI were accompanied by a significant heart rate reduction (75.5+/-17.7 bpm after BMS versus 69.0+/-16.9 bpm after PPVI; P=0.006) at maintained cardiac output (2.5+/-0.5 versus 2.4+/-0.5 versus 2.7+/-0.5 mL x min(-1) x m(-2); P=0.14). Using an x-ray/magnetic resonance hybrid laboratory, we have demonstrated the superior acute hemodynamic effects of PPVI over BMS in patients with right ventricular outflow tract obstruction.
    Circulation 06/2009; 119(23):2995-3001. · 15.20 Impact Factor
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    ABSTRACT: In recent large paediatric cardiomyopathy population studies from North America and Australia, vitamin D deficiency was not identified as a cause of infant heart failure. However, rickets is resurgent in developed countries. To review the prevalence of this cardiomyopathy in paediatric cardiology units of southeast England and determine the prognosis. A retrospective review from 2000 to 2006 in southeast England. Sixteen infants (6 Indian subcontinent, 10 black ethnicity) were identified: median (range) age at presentation was 5.3 months (3 weeks-8 months). All had been breast fed. Ten presented at the end of the British winter (February-May). Median shortening fraction was 10% (range 5-18%) and median left ventricular end diastolic dimension z score was 4.1 (range 3.1-7.0). Six had a cardiac arrest; three infants died. Eight were ventilated, two required mechanical circulatory support and 12 required intravenous inotropic support. Two were referred for cardiac transplantation. Median (range) of biochemical values on admission was: total calcium 1.5 (1.07-1.74) mmol/l; alkaline phosphatase 646 (340-1057) IU/l; 25-hydroxyvitamin D 18.5 (0-46) nmol/l (normal range >35) and parathyroid hormone 34.3 (8.9-102) pmol/l (normal range <6.1). The clinical markers and echocardiographic indices of all survivors have improved. The mean time from diagnosis to achieve normal fractional shortening was 12.4 months. Vitamin D deficiency and consequent hypocalcaemia are seen in association with severe and life-threatening infant heart failure. That no infant or mother was receiving the recommended vitamin supplementation highlights the need for adequate provision of vitamin D to ethnic minority populations.
    Heart (British Cardiac Society) 06/2008; 94(5):581-4. · 5.01 Impact Factor
  • Ultrasound in Obstetrics and Gynecology 09/2007; 30(4):597 - 597. · 3.56 Impact Factor
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    ABSTRACT: In children, mechanical mitral valve replacement may be the only option if the failing mitral valve cannot be repaired. Mandatory anticoagulation and the fixed size prosthesis are of concern in the growing child, but long-term follow-up results are lacking. Single centre, extended retrospective study of 54 patients who underwent first mitral valve replacement between June 1982 and December 1997. Median age at operation was 3.0 years (range 2 days-18.1 years), 21 patients were<or=2.0-year-old. Mitral valve replacement was performed for congenital (43 patients) or acquired (11 patients) heart disease. Median follow-up for operative survivors was 9.2 years, with follow-up>15 years (maximum 22 years) in nine patients. Thirty-day mortality was 42% in patients<or=2-year-old, and 6% in older patients. There were 10 late deaths. Estimated survival at 10 and 15 years follow-up was 33%+/-19% and 33+/-27% in patients<or=2-year-old, and 81%+/-8% and 75%+/-16% in older patients, respectively. High operative mortality in the younger age group was the most important contributor to poor long-term survival. Fifteen patients underwent redo-mitral valve replacement with one operative death. A larger valve was always implanted. Freedom from redo-mitral valve replacement at 10 and 15 years was 25%+/-22% and 0% in patients with prostheses<23 mm, and 83%+/-13% and 83%+/-27% in patients with larger prostheses. Significant bleeding events occurred in eight patients and were often associated with operative interventions. Estimated freedom from bleeding was 75.7%+/-9% and 70.6%+/-16% at 10 and 15 years, respectively. Thromboembolism and endocarditis were rare. There was no structural valve failure. Estimated freedom from all adverse events at 10 years follow-up was 17%+/-13%. At 10 years follow-up after mechanical mitral valve replacement, most children had suffered an adverse event. At 15 years, all children with a prosthesis<23 mm had outgrown their valve, but redo-mitral valve replacement with a larger size prosthesis was always possible, and carried low operative risk. Long-term anticoagulation was well tolerated. In children every effort should be made to preserve the native valve.
    European Journal of Cardio-Thoracic Surgery 06/2007; 31(5):860-5. · 2.67 Impact Factor
  • Ultrasound in Obstetrics and Gynecology 08/2006; 28(4):397 - 397. · 3.56 Impact Factor
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    ABSTRACT: Following stenting for coarctation of the aorta, it can be difficult to image the stent adequately using cross-sectional echocardiography. Unless there is marked clinical concern regarding stent patency, repeat cardiac catheterization is not warranted. Multidetector computed tomography (MDCT) is a useful alternative imaging modality. We report a case that highlights the clinical utility of MDCT for imaging patients who have had stenting of aortic coarctation. MDCT clearly revealed stent fracture as the cause of late stent failure and recoarctation.
    Catheterization and Cardiovascular Interventions 12/2005; 66(3):420-3. · 2.51 Impact Factor
  • Ultrasound in Obstetrics and Gynecology 09/2005; 26(4):413 - 413. · 3.56 Impact Factor
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    ABSTRACT: Occurrence of neonatal circulatory collapse imposes effective differential diagnosis and expeditious therapeutic intervention. We report a case of neonatal cardiogenic shock, caused by a massive intra-cardiac fungal vegetation.
    European Journal of Cardio-Thoracic Surgery 09/2003; 24(2):323-4. · 2.67 Impact Factor
  • Ultrasound in Obstetrics and Gynecology 08/2003; 22(S1):50 - 50. · 3.56 Impact Factor
  • Ultrasound in Medicine and Biology - ULTRASOUND MED BIOL. 01/2003; 29(5).
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    ABSTRACT: A total of 15 fetuses were scanned using 2-D array volumetric ultrasound (US). Acquired cardiac data were converted for rendering dynamic 3-D surface views and reformatting cross-sectional views. The image usefulness was compared between the data obtained from subcostal/subxiphoid and other imaging windows; the former are usually free of acoustic shadowing. Of 60 data sets recorded, 12 (20%) were acquired through subcostal windows in 6 (40%) patients. Subcostal windows were unavailable from the remaining patients due to unfavourable fetal positions. Of the 12 sets, 6 (50%) provided the dynamic 3-D and/or cross-sectional views of either the entire fetal heart or a great portion of it for sufficient assessments of its major structures and their spatial relationships. Of 48 data sets from other windows, only 9 (19%) provided such 3-D and/or cross-sectional views; the lower rate being due to acoustic shadowing. Real-time 3-D US is a convenient method for volumetric data acquisition. Through subcostal windows, useful information about the spatial relationships between major cardiac structures can be acquired. However, to offer detailed information, considerable improvement in imaging quality is needed.
    Ultrasound in Medicine & Biology 10/2002; 28(9):1099-105. · 2.46 Impact Factor
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    ABSTRACT: To develop dynamic three-dimensional ultrasound techniques for prenatal imaging of the intracardiovascular flow as well as the cardiovascular structure to address difficulties in assessing the spatially complex hemodynamics and morphology of the fetal heart. Gray-scale and color (velocity) Doppler echocardiography were performed on 12 fetuses to provide serial anatomical and rheological tomograms which were spatially registered in three dimensions. Using a second ultrasound machine simultaneously, spectral Doppler ultrasound was performed to record umbilical arterial waveforms, thus providing the temporal (fourth) dimension in terms of the cardiac cycle and facilitating removal of motion artifacts. Acquisitions were successful in eight of 15 attempts. Imaging of the flow of blood in four dimensions was achieved in six of the eight datasets. In one case with complex cardiac malformations, three-dimensional reconstructions at systole and diastole offered dynamic diagnostic views not appreciated on the cross-sectional images. Our novel technique has made possible the prenatal visualization of the spatial distribution and true direction of intracardiac flow of blood in four dimensions in the absence of motion artifacts. The technique suggests that diagnosis of cardiac malformations can be made on the basis of morphological and hemodynamic changes throughout the entire cardiac cycle, offering unique and significant information complementary to conventional techniques. Further work to integrate the several non-purpose-built machines into a single system will improve the rate of acquisition of data, and may provide a new means of imaging and modeling structure and hemodynamics, not only for the fetal heart but for many other moving body parts.
    Ultrasound in Obstetrics and Gynecology 09/2002; 20(2):131-6. · 3.56 Impact Factor
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    ABSTRACT: A distinct defect has been described within the apical part of the muscular ventricular septum, which has multiple orifices when seen from its right ventricular aspect. Closure has been suggested using umbrella devices introduced on a catheter. Such an intervention, however, can be technically difficult in small infants. We have recently seen two examples of this type of complex communication between the apexes of both left and right ventricles. Neither could be closed by catheterization. A surgical approach was used through a modified apical right ventriculotomy. We have also studied two autopsied specimens, which clarify the morphologic arrangement. Both patients were closed successfully, with trivial residual shunt and good biventricular functions. The patients were clinically well at 2-year follow-up. Surgical division of right ventricular trabeculations makes it feasible to identify and repair the septal deficiency, which is a solitary hole. On the basis of our morphologic study, we offer an explanation for the anatomic arrangement that differs from the one proposed by recent previous investigators. If the ventricular incision is appropriately placed, our anatomic studies suggest that it is possible to visualize the solitary opening from its right ventricular aspect, and achieve surgical closure with a single patch.
    The Annals of Thoracic Surgery 02/2002; 73(1):58-62; discussion 62-3. · 3.45 Impact Factor
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    ABSTRACT: We report a traumatic disruption of the ascending aorta in an 8-year-old boy who had undergone orthotopic cardiac transplant at 6.5 years of age for congenital heart block and dilated cardiomyopathy. At presentation his aortic injury was not immediately recognized, but persistence in identifying and confirming a suspicious aortic rupture was lifesaving.
    The Annals of Thoracic Surgery 08/2001; · 3.45 Impact Factor
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    ABSTRACT: The aim of this study was to visualise the fetal heart in dynamic three dimensions (4-D) during an ultrasound (US) scan (online), rather than after (offline). With special pairing and sequential setting to minimise interference between two scanners, umbilical arterial Doppler waveforms (UADWs) from one scanner were used as an online motion gating source to trigger simultaneous 3-D cardiac structural data acquisition by another. Of 25 data sets from 10 fetuses, 18 were acquired in 15 to 30 s per set with > or = 50% Doppler waveforms efficiently converted to triggering signals. Of 15 valid 4-D data sets, 10 were reconstructed in 2 to 20 min, compared to over 2 h previously reported (mainly for offline gating). Fine structures (including chordae tendinae and trabecular muscles) were depicted in six sets. The main problems in degrading 4-D images were extensive shadowing (6) from bony structures during rigid mechanical scanning, and random motion artefacts (6) from prolonged setting-up time with a complex combination of several systems. Integration of these systems is, therefore, recommended.
    Ultrasound in Medicine & Biology 02/2001; 27(1):43-50. · 2.46 Impact Factor