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Dive into the research topics where Graham R. Nunn is active.

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Featured researches published by Graham R. Nunn.


The Journal of Thoracic and Cardiovascular Surgery | 1999

Simplified single patch technique for the repair of atrioventricular septal defect

Ian A. Nicholson; Graham R. Nunn; Gary F. Sholler; R E Hawker; Stephen G. Cooper; Kai C. Lau

OBJECTIVE Because of the complexity of traditional 1- and 2-patch techniques for the repair of complete atrioventricular septal defect, we modified our repair technique to avoid the use of any ventricular septal patch material. We report our prospective experience with this simplified 1-patch technique. METHOD Forty-seven consecutive patients between May 1995 and August 1998 underwent repair with the use of this technique without modification. Repair was done in all patients by direct suturing of the common atrioventricular valve leaflets to the crest of the ventricular septum. No division of valve leaflets was necessary. A single pericardial patch was used to close the defect in the atrial septal component. Follow-up included electrocardiography and echocardiographic assessment of ventricular function, atrioventricular valve function, and adequacy of the left ventricular outflow tract. RESULTS There were 2 deaths (4%), only 1 cardiac related, in the series. There were 17 male patients and 30 female patients. Mean age at repair was 5.6 months (median, 3.4 months). Associated lesions were repaired in 19 patients (40%). Mean follow-up was 1.85 years (median, 1.9 years). There was no heart block. There were no significant residual ventricular septal defects detected and no left ventricular outflow tract obstruction seen on echocardiography in any patient to date. Mitral valve status after operation was assessed as no incompetence in 13 patients (28%), minimal in 19 patients (40%), mild in 12 patients (26%), and moderate in 3 patients (6%). CONCLUSION The repair of complete atrioventricular septal defect by direct suturing of the atrioventricular valve leaflets to the crest of the ventricular septum with a single-patch technique greatly simplifies the repair and does not lead to left ventricular outflow tract obstruction nor interfere with valve function.


Cardiology in The Young | 2008

The improvement of care for paediatric and congenital cardiac disease across the World: a challenge for the World Society for Pediatric and Congenital Heart Surgery

Christo I. Tchervenkov; Jeffrey P. Jacobs; Pierre Luc Bernier; Giovanni Stellin; Hiromi Kurosawa; Constantine Mavroudis; Richard A. Jonas; Sertaç Çiçek; Zohair Al-Halees; Martin J. Elliott; Marcelo Biscegli Jatene; Robin H. Kinsley; Christian Kreutzer; Juan Leon-Wyss; Jinfen Liu; Bohdan Maruszewski; Graham R. Nunn; Samuel Ramirez-Marroquin; Néstor Sandoval; Shunji Sano; George E. Sarris; Rajesh Sharma; Ayman Shoeb; Thomas L. Spray; Ross M. Ungerleider; Hervé Yangni-Angate; Gerhard Ziemer

The diagnosis and treatment for paediatric and congenital cardiac disease has undergone remarkable progress over the last 60 years. Unfortunately, this progress has been largely limited to the developed world. Yet every year approximately 90% of the more than 1,000,000 children who are born with congenital cardiac disease across the world receive either suboptimal care or are totally denied care.While in the developed world the focus has changed from an effort to decrease post-operative mortality to now improving quality of life and decreasing morbidity, which is the focus of this Supplement, the rest of the world still needs to develop basic access to congenital cardiac care. The World Society for Pediatric and Congenital Heart Surgery [http://www.wspchs.org/] was established in 2006. The Vision of the World Society is that every child born anywhere in the world with a congenital heart defect should have access to appropriate medical and surgical care. The Mission of the World Society is to promote the highest quality comprehensive care to all patients with pediatric and/or congenital heart disease, from the fetus to the adult, regardless of the patients economic means, with emphasis on excellence in education, research and community service.We present in this article an overview of the epidemiology of congenital cardiac disease, the current and future challenges to improve care in the developed and developing world, the impact of the globalization of cardiac surgery, and the role that the World Society should play. The World Society for Pediatric and Congenital Heart Surgery is in a unique position to influence and truly improve the global care of children and adults with congenital cardiac disease throughout the world [http://www.wspchs.org/].


The Journal of Thoracic and Cardiovascular Surgery | 2000

Transcaval repair of the sinus venosus syndrome.

Ian A. Nicholson; R.B. Chard; Graham R. Nunn; T.B. Cartmill

BACKGROUND Surgical correction of the sinus venosus syndrome has been associated with sinus node dysfunction and venous obstruction postoperatively. We present the long-term follow-up of a lateral transcaval approach, which closes the atrial communication and corrects the partial anomalous pulmonary venous connection to the superior vena cava with the use of a simple pericardial patch. METHODS The records of 66 patients undergoing repair between April 1981 and April 1997 were examined. Mean age at repair was 10.2 years (range, 1.5-65 years; median, 5 years). Six patients had a left superior vena cava, 4 had an additional atrial septal defect, and 2 had coronary artery bypass grafts. Immediate and long-term follow-up included physical examination, electrocardiography, transthoracic echocardiography, and use of a 24-hour ambulatory Holter monitor. Sinus node function, incidence of significant arrhythmia, and evidence of mechanical venous obstruction were assessed. RESULTS Follow-up data were available for 64 (97%) patients for a mean follow-up of 4.1 years (range, 1-9 years). There were no deaths. No evidence of residual atrial septal defect, superior vena cava, or venous obstruction were found by echocardiography. On electrocardiography all patients were in sinus rhythm, with no arrhythmia seen. Holter monitoring was performed at a mean of 7.3 years postoperatively. All patients had normal sinus node function, and no sustained atrial arrhythmia was seen. CONCLUSION Transcaval repair is a simple technique that does not interfere with sinus node function. There is no evidence to suggest that this approach leads to venous obstruction.


The Annals of Thoracic Surgery | 2001

Reoperation and coarctation of the aorta: the need for lifelong surveillance

Con Manganas; Jim Iliopoulos; Richard Chard; Graham R. Nunn

BACKGROUND We report a series of reoperations in 23 patients who had undergone previous aortic coarctation repair. METHODS The medical records of these patients were reviewed, and the patients were followed up by telephone interview. Mean age at reoperation was 25 years. There was a mean of 18 years between initial coarctation repair and reoperation. Indications for reoperation included recoarctation (9 patients), aortic aneurysm (8), aortobronchial fistulas with exsanguinating hemorrhage (2), subaortic stenosis (1), ruptured thoracic aneurysm (1), ruptured sinus of Valsalva aneurysm (1), and supramitral stenosing ring (1). RESULTS There were no specific intraoperative complications. Three patients required reexploration for bleeding. An acutely ischemic lower limb developed in 1 patient secondary to a common femoral artery embolus, which necessitated embolectomy. CONCLUSIONS Reoperation for postcoarctation repair patients can be performed with good results. Sudden life-threatening hemorrhage due to aortobronchial fistulas in patients having undergone Dacron patch aortoplasty, as well as long-term obstructive phenomena seen anywhere along the left ventricular outflow tract, make lifelong surveillance of these patients mandatory.


The Annals of Thoracic Surgery | 2001

Use of the Medtronic freestyle valve as a right ventricular to pulmonary artery conduit

Richard Chard; Nicholas Kang; David R Andrews; Graham R. Nunn

BACKGROUND We have used the Medtronic Freestyle bioprosthesis as a right ventricular to pulmonary artery conduit recently in an attempt to overcome some of the problems associated with homografts and stented xenografts. The aim of this study was to review the performance of this prosthesis. METHODS Prospectively collected data for patients having Freestyle bioprostheses implanted as a right ventricular to pulmonary artery conduit were reviewed to assess clinical outcome and echocardiographic results. RESULTS Thirteen patients aged 13 days to 22.5 years (median, 7.9 years) underwent either primary repair (n = 5) or change of conduit (n = 8) using the Freestyle bioprosthesis. One neonate with truncus arteriosus died postoperatively of pulmonary hypertension. One conduit was explanted 27 months after repair of neonatal truncus arteriosus. There has been no incidence of significant prosthetic regurgitation, thromboembolism, or endocarditis at mean follow-up of 10.1 months (range, 2 weeks to 29 months). CONCLUSIONS The Medtronic Freestyle valve is a reliable pulmonary valve substitute in the short term. Early results justify continued clinical use of the device in this setting with close follow-up.


The Journal of Thoracic and Cardiovascular Surgery | 2008

Durability of hand-sewn valves in the right ventricular outlet

Graham R. Nunn; Jayme Bennetts; Ella Onikul

OBJECTIVE The objective was to compare the medium- and long-term outcomes for pericardial monocusp valves, polytetrafluoroethylene (Gore-Tex, WL Gore and Associates Inc, Flagstaff, Ariz) 0.1-mm monocusp valves, and bileaflet 0.l-mm polytetrafluoroethylene valves and their efficiency in the right ventricular outlet. METHODS We reviewed all hand-sewn right ventricular outlet valves created by the author (Graham R. Nunn) in the setting of repaired tetralogy of Fallot or equivalent right ventricular outlet pathology when the native pulmonary valve could not be preserved. The valves were assessed by serial transthoracic echocardiography and more recently by magnetic resonance imaging angiography for late valve function. The bileaflet polytetrafluoroethylene valves were constructed in a standardized fashion from a semicircle of 0.1-mm polytetrafluoroethylene (the radius of which equaled the length of the outflow tract incision) that gave a lengthened free edge to the leaflets, central fixation of the free edge posteriorly just proximal to the branch pulmonary arteries, and generous augmentation of the outflow tract with polytetrafluoroethylene patch-plasty. The bileaflet configuration shortens the closing time against the posterior wall, and the leaflets are forced to maintain their configuration without prolapse into the right ventricular outlet. The valve can be generously oversized in young children to try to avoid the need for replacement. RESULTS A total of 54 patients met the selection criteria--22 patients received fresh autologous pericardial monocusps, 7 patients received polytetrafluoroethylene (0.1-mm) monocusps, and 25 patients received bileaflet polytetrafluoroethylene (0.1-mm) outlet valves. The pericardial valves have the longest follow-up, and all valves developed free pulmonary incompetence. Polytetrafluoroethylene monocusps had reliable competence early after surgery but progressed to pulmonary incompetence. The bileaflet polytetrafluoroethylene (0.1-mm) valves have remained competent with regurgitant fractions of only 5% to 30% (magnetic resonance imaging angiography), and this has remained stable with time. The maximum follow-up for these valves is 5 years. No stenosis or peripheral emboli have been recognized, and no valves have been replaced to date. CONCLUSION Hand-sewn bileaflet polytetrafluoroethylene valves in the right ventricular outlet can reliably provide competence and maintain function in the medium term. Their shape and size allow placement in young children with a reasonable expectation that they will remain competent with growth of the native annulus and not require replacement. Their durability is superior to the pericardial and polytetrafluoroethylene monocusp valves in this series.


The Annals of Thoracic Surgery | 2004

Successful Early Surgical Recruitment of the Congenitally Disconnected Pulmonary Artery

David N Murphy; David S. Winlaw; Steve G Cooper; Graham R. Nunn

BACKGROUND Our purpose was to document our experience with early recruitment of congenitally disconnected pulmonary arteries and to assess subsequent pulmonary artery growth and function. METHODS Patients born in the 10-year period from 1989 to 1999 with a disconnected pulmonary artery diagnosed in infancy and treated in our unit were studied. To be included patients had nonconfluent pulmonary arteries with one or both completely disconnected from the main pulmonary artery. This series did not include patients with acquired stenosis causing occlusion of a pulmonary artery. Echocardiography, cardiac catheterization, MRI, lung perfusion scans, and intraoperative assessment were used to gauge pulmonary artery growth and function. RESULTS Seven patients with a disconnected pulmonary artery associated with intracardiac conotruncal congenital cardiac disease underwent successful early surgical recruitment of the affected pulmonary artery at 3 months of age or younger. Median follow-up from date of first operation was 4.2 years (range, 1.6 to 13.4). All 7 patients had postrecruitment lung perfusion scans showing a mean of 44% (range, 27% to 78%) of total pulmonary flow through the affected lung. Significant growth in the diameter of the recruited native pulmonary artery was demonstrated in all patients. There were no deaths reported in our series to date. CONCLUSIONS The rare possibility of a congenitally disconnected pulmonary artery needs to be considered in all patients with a conotruncal cardiac anomaly. To facilitate surgical correction, ensure subsequent growth of the pulmonary artery, and optimize associated lung development, early diagnosis and surgical recruitment is recommended.


Pediatric Cardiology | 1989

Nitroprusside in children after cardiopulmonary bypass: A study of thiocyanate toxicity

Suripon Kunathai; Gary F. Sholler; John M. Celermajer; Mary O'Halloran; Timothy B. Cartmill; Graham R. Nunn

SummaryThiocyanate levels, an indicator of nitroprusside toxicity, were studied in 22 children after repair of structural heart disease during cardiopulmonary bypass. At the total dose (2.6±2.3 mg/kg) and time (34.4±19 h) ranges of this study, no evidence of toxicity was detected, despite this total dose exceeding recommended maximum in some patients. Nitroprusside infusion, as described, in children with normal hepatic and renal function is safe and may not warrant routine assessment of thiocyanate levels.


Cardiology in The Young | 2010

Anomalous aortic origin of a coronary artery: a universally applicable surgical strategy.

Tom R. Karl; Sylvio Provenzano; Graham R. Nunn

The most commonly reported coronary arterial malformation, in accounts of sudden deaths, is anomalous aortic origin of a coronary artery. Anomalous coronary arteries may arise from the left, right, or non-coronary sinuses of Valsalva. Importantly, although the left coronary artery from the right sinus has the worst prognosis, sudden death has been reported in all variants of origin from the various sinuses of Valsalva. This paper describes a technique that addresses all of the problems relating to anomalous aortic origin of a coronary artery from the wrong sinus of Valsalva. This technique includes the transection of the ascending aorta and pulmonary trunk, coronary arterial enlargement with a pericardial patch, and lateral translocation of the pulmonary trunk to the left pulmonary artery. Anomalous aortic origin of a coronary artery from the wrong sinus of Valsalva is a potentially lethal cardiac anomaly that can be corrected in all cases using this simplified surgical technique that addresses the major anatomic and physiological problems.


Cardiology in The Young | 2010

The current surgical perspective to repair of atrioventricular septal defect with common atrioventricular junction

Tom R. Karl; Sylvio Provenzano; Graham R. Nunn; Robert H. Anderson

Atrioventricular septal defect with common atrioventricular junction is a relatively common congenital cardiac malformation. It sometimes presents challenging surgical problems, especially when seen in combination with tetralogy of Fallot. We describe herein our current concepts regarding surgical repair of atrioventricular septal defect with and without tetralogy, discussing indications for surgery, timing, technical aspects, and outcomes.

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Gary F. Sholler

Children's Hospital at Westmead

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Richard Chard

Boston Children's Hospital

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Richard A. Jonas

Children's National Medical Center

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Bohdan Maruszewski

Memorial Hospital of South Bend

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Peter W. Grant

Boston Children's Hospital

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