Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Christopher J. Knott-Craig is active.

Publication


Featured researches published by Christopher J. Knott-Craig.


The Journal of Thoracic and Cardiovascular Surgery | 2011

Complete repair of Ebstein anomaly in neonates and young infants: A 16-year follow-up

Umar S. Boston; Steven P. Goldberg; Kent E. Ward; Edward D. Overholt; Thomas Spentzas; Thomas K. Chin; Christopher J. Knott-Craig

OBJECTIVEnThe purpose of this study was to review the long-term outcome of patients with Ebstein anomaly who underwent complete repair as neonates and young infants.nnnMETHODSnBetween March 1994 and May 2010, 32 patients (23 neonates and 9 young infants) underwent surgery for Ebstein anomaly. Mean weight was 3.9 ± 2.0 kg (range, 1.9-8.6 kg). The Great Ormond Street Echocardiography score was greater than 1.5 in 22 of the 23 neonates and greater than 1.0 in all infants. All associated cardiac defects were repaired including pulmonary atresia in 15 and ventricular septal defect in 4. Primary outcome measures included (1) early and late survival, (2) freedom from reoperation, (3) durability of tricuspid valve repair, and (4) functional status.nnnRESULTSnEarly survival was 78.1% (25/32). There was 1 late death. Fifteen-year survival estimate was 74% ± 8%. For patients with pulmonary atresia, early and late survival was 60% ± 12% (9/15) versus 94.1% (16/17) (P < .05), respectively; for those without pulmonary atresia, early and late survival was 60% ± 12% versus 85% ± 10 (P = .06), respectively. The mean follow-up was 5.9 ± 4.5 years (0.1-16 years). A biventricular repair was achieved in 90.6% (29/32) patients. Median preoperative tricuspid regurgitation was 4/4 and at late follow-up, 1/4. Freedom from reoperation at 15 years was 74% ± 10% for patients undergoing biventricular repair. All survivors are in New York Heart Association class I or II.nnnCONCLUSIONSnBiventricular repair of Ebstein anomaly in symptomatic neonates is feasible with good early and late survival, especially in those without pulmonary atresia. Tricuspid valve repair is durable, and functional status is excellent.


The Journal of Pediatrics | 2010

Surgical management of intrapericardial teratoma in the fetus.

Steven P. Goldberg; Umar S. Boston; Dima A. Turpin; Giancarlo Mari; Craig A. Mathis; Thomas K. Chin; Christopher J. Knott-Craig

Intrapericardial teratomas often present as life-threatening problems when diagnosed during fetal life. They are large lesions that compress the heart and lungs and can result in tamponade if not treated expeditiously. We present a case of a large teratoma that was managed by prenatal pericardiocentesis followed by surgical resection.


Jacc-cardiovascular Interventions | 2016

Feasibility and Safety of Unzipping Small Diameter Stents in the Blood Vessels of Piglets

Shyam Sathanandam; T.K. Susheel Kumar; Deepthi Hoskoppal; Lauren M. Haddad; Saradha Subramanian; Ryan Sullivan; David Zurakowski; Christopher J. Knott-Craig; B. Rush Waller

OBJECTIVESnThis study sought to determine the feasibility and safety of unzipping small-diameter stents (SDS) in a growing animal model.nnnBACKGROUNDnSDS implanted to relieve stenosis of blood vessels in infants may result in refractory stenosis as the child grows. If stents can be longitudinally fractured-unzipped-then the target vessel can potentially be redilated to the eventual adult vessel diameter.nnnMETHODSnFifty stents (diameter 4 to 7 mm) were implanted in 5 neonatal piglets (mean age and weightxa0= 1.5 weeks and 3.4 kg). Pre-mounted coronary (CS) (nxa0= 24), biliary (BS) (nxa0= 14), nitinol (NS) (nxa0= 3), and renal stents (RS) (nxa0= 9) were implanted in pulmonary arteries (nxa0= 13), systemic arteries (nxa0= 25), and systemic veins (nxa0= 12). Three months later (median weightxa0= 32 kg), unzipping was attempted by dilating the stents.nnnRESULTSnAll CS and RS unzipped at twice their nominal diameter withxa0<20% shortening. None of the NS unzipped. The BS shortened the most (∼40%), with only 69% of the stents unzipping. Stainless steel CS and RS with an open cell design were significant predictors (pxa0≤ 0.01) for unzipping. On histopathology, unzipping of the BS caused the most medial dissection and vessel wall injury, while unzipping of the CS caused the least.nnnCONCLUSIONSnUnzipping of small-diameter CS and RS implanted in systemic and pulmonary vessels is more feasible than the BS and NS. This study may encourage the implantation of small stents in infant blood vessels and aid in selection of appropriate stent type.


The Annals of Thoracic Surgery | 2015

Superior Vena Cava Reconstruction for Treatment of Chylothorax Resulting From Thrombosis of Superior Vena Cava in Young Infants

T.K. Susheel Kumar; Saradha Subramanian; Shyam Sathanandam; John Alexander; Mohammed Ali; Christopher J. Knott-Craig

BACKGROUNDnThrombosis and occlusion of the superior vena cava (SVC) can cause massive chylothorax resulting in significant morbidity and mortality among young infants. Medical therapy is often unsuccessful. We report a new surgical technique that entails open thrombectomy and reconstruction of the SVC and innominate vein to treat this condition.nnnMETHODSnThe charts of 4 consecutive infants with chylothoraces refractory to conservative management were reviewed. The operations were performed on cardiopulmonary bypass without myocardial arrest. The SVC and innominate veins were incised open, and thrombectomy was performed. This was followed by homograft patch reconstruction of both the veins.nnnRESULTSnThe infants were aged between 5 weeks to 4 months and had an average weight of 4 kg. All of them had hypoalbuminemia and evidence of hypercoagulable state. After surgical intervention, 3 had complete relief of SVC obstruction. Two of the 3 patients had complete resolution of chylous effusion, and the third patient had a significant decrease in chest tube drainage (70%) by the end of 1 week. The fourth patient had recurrence of high drainage after an initial improvement, and a subsequent angiogram demonstrated stenosis of the SVC without thrombosis. The chest tube drainage finally resolved after balloon angioplasty.nnnCONCLUSIONSnThrombotic occlusion of the SVC can result in chylothorax that is often not amenable to medical therapy. This is associated with significant loss of proteins and hypercoagulable state. A complete surgical relief of SVC obstruction by open thrombectomy and venoplasty can result in dramatic decrease in chylous output.


Cardiology in The Young | 2015

Surgical management of symptomatic neonates with Ebstein's anomaly: choice of operation.

Christopher J. Knott-Craig; Thittamaranahalli Kariyappa S. Kumar; Alejandro Arevalo; Vijaya M. Joshi

OBJECTIVEnSymptomatic neonates with Ebsteins anomaly pose significant challenge. Within this cohort, neonates with associated anatomical pulmonary atresia have higher mortality. We review our experience with this difficult subset.nnnMETHODSnA total of 32 consecutive symptomatic neonates with Ebsteins anomaly underwent surgical intervention between 1994 and 2013. Of them, 20 neonates (62%, 20/32) had associated pulmonary atresia. Patients weights ranged from 1.9 to 3.4 kg. All patients without pulmonary atresia had two-ventricle repair. Of the 20 neonates, 16 (80%, 16/20) with Ebsteins anomaly and pulmonary atresia had two-ventricle repair and 4 had single-ventricle palliation, of which 2 underwent Starnes palliation and 2 Blalock-Taussig shunts. Six recent patients with Ebsteins anomaly and pulmonary atresia had right ventricle to pulmonary artery valved conduit as part of their two-ventricle repair.nnnRESULTSnOverall early mortality was 28% (9/32). For those without pulmonary atresia, mortality was 8.3% (1/12). For the entire cohort of neonates with Ebsteins anomaly and pulmonary atresia, mortality was 40% (8/20; p=0.05). Mortality for neonates with Ebsteins anomaly and pulmonary atresia having two-ventricle repair was 44% (7/16). Mortality for neonates with Ebsteins anomaly and pulmonary atresia having two-ventricle repair utilising right ventricle to pulmonary artery conduit was 16% (1/6). For those having one-ventricle repair, the mortality was 25% (1/4).nnnCONCLUSIONSnSurgical management of neonates with Ebsteins anomaly remains challenging. For neonates with Ebsteins anomaly and anatomical pulmonary atresia, single-ventricle palliation is associated with lower early mortality compared with two-ventricle repair. This outcome advantage is negated by inclusion of right ventricle to pulmonary artery conduit as part of the two-ventricle repair.


Cardiology in The Young | 2016

Management of hypoplastic left heart syndrome with intact atrial septum: a two-centre experience

Shyam Sathanandam; Ranjit Philip; David Gamboa; Andrew H. Van Bergen; Michel N. Ilbawi; Christopher J. Knott-Craig; B. Rush Waller; Alexander J. Javois; Bettina F. Cuneo

UNLABELLEDnIntroduction Hypoplastic left heart syndrome with an intact atrial septum is a poor predictor of outcomes. Prenatal assessment of pulmonary venous Doppler and emergent postnatal cardiac intervention may be associated with better outcomes. Materials and methods A retrospective review of all hypoplastic left heart syndrome patients in two centres over a 5-year period was performed. Group 1 included patients with adequate inter-atrial communication. Group 2 included patients with prenatal diagnosis with an intact atrial septum who had immediate transcatheter intervention. Group 3 included patients with intact atrial septum who were not prenatally diagnosed and underwent either delayed intervention or no intervention before stage 1 palliation. Primary outcome was survival up to stage 2 palliation.nnnRESULTSnThe incidence of hypoplastic left heart syndrome with a restrictive atrial communication was 11.2% (n=19 of 170). Overall survival to stage 2 or heart transplantation was 85% and 67% for Groups 1 and 2, respectively (n=129/151, n=8/12; p=0.03), and 0% (n=0/7) for Group 3. Survival benefits were observed between Groups 2 and 3 (p<0.001). Foetal pulmonary vein Doppler reverse/forward velocity time integral ratio of ⩾18% (sensitivity, 0.99, 95% CI, 0.58-1; specificity, 0.99, 95% CI, 0.96-1) was predictive of the need for emergent left atrial decompression.nnnCONCLUSIONnUsing a multidisciplinary approach and foetal pulmonary vein Doppler, time-saving measures can be instituted by delivering prenatally diagnosed neonates with hypoplastic left heart syndrome with intact atrial septum close to the cardiac catheterisation suite where left atrial decompression can be performed quickly and safely that may improve survival.


Journal of intensive care | 2015

Management of massive diffuse alveolar hemorrhage in a child with systemic lupus erythematosus

Dai Kimura; Samir Shah; Mario Briceno-Medina; Shyam Sathanandam; Brent Haberman; Jie Zhang; Linda K. Myers; T.K. Susheel Kumar; Christopher J. Knott-Craig

Diffuse alveolar hemorrhage (DAH) from systemic lupus erythematosus (SLE) is a rare but potentially life-threatening condition. We report the case of a 14-year-old female with SLE who developed hypoxia and shock secondary to severe alveolar hemorrhage. She was successfully managed by placement on extracorporeal membrane oxygenation (ECMO) followed by emergent pulmonary lobectomy and medical treatment including high-dose methylprednisolone, cyclophosphamide, intravenous immunoglobulin, and plasmapheresis.


Cardiology in The Young | 2015

Lessons learned with the use of CentriMag as short-term ventricular assist device in a child.

Thittamaranahalli Kariyappa S. Kumar; Jean A. Ballweg; Christopher J. Knott-Craig

The CentriMag ventricular assist device is an extracorporeal, third-generation, continuous flow device. The rapidity and simplicity of operation along with low priming volume make it attractive for use in children with refractory heart failure. We report the successful use of CentriMag as a bridge to recovery in a child and discuss issues that are unique to its use in children.


Cardiology in The Young | 2018

Femoral vein homograft as Sano shunt results in improved pulmonary artery growth after Norwood operation

Mario Briceno-Medina; T.K. Susheel Kumar; Shyam Sathanandam; Umar S. Boston; Michael Perez; Jerry Allen; David Zurakowski; Michel N. Ilbawi; Christopher J. Knott-Craig

OBJECTIVEnTo evaluate differences in interstage growth of pulmonary arteries between use of polytetrafluoroethylene and femoral vein homograft as Sano shunt during stage-I Norwood palliation.nnnMETHODSnA retrospective review of all patients who survived to the second stage following Norwood-Sano operation at two institutions was performed. Either polytetrafluoroethylene or the valved segment of femoral vein homograft was used for construction of the Sano shunt. The size of pulmonary arteries was compared at pre-Glenn catheterisation.nnnRESULTSnA total of 48 neonates with the diagnosis of hypoplastic left heart syndrome or its variants comprised the study population. Femoral vein homograft of 5-6 mm diameter was used in 14 and polytetrafluoroethylene graft of 5 mm was used in 34 patients. The two groups were comparable in terms of preoperative demographics and age at time of pre-Glenn catheterisation (3.9±0.7 versus 3.4±0.8 months, p=0.06). Patients who received femoral vein homograft demonstrated a significantly higher pre-Glenn Nakata index [264 (130-460) versus 165 (108-234) mm2/m2, p=0.004]. The individual branch pulmonary arteries were significantly larger in the femoral vein group (right, 7.8±3.6 versus 5.0±1.2, p=0.014; left, 7.2±2.1 versus 5.6±1.9, p=0.02). There were no differences in cardiac index, Qp:Qs, ventricular end-diastolic pressure or systemic oxygen saturations.nnnCONCLUSIONSnUtilisation of a valved segment of femoral vein homograft as right ventricle to pulmonary artery conduit during Norwood-Sano operation confers better interstage growth of the pulmonary arteries. Further studies are needed to evaluate the impact of femoral vein homograft on single ventricle function.


World Journal for Pediatric and Congenital Heart Surgery | 2012

Apical Left Ventriculotomy is Safe in Infants and Young Children Requiring Cardiac Surgery.

Steven P. Goldberg; Christopher J. Knott-Craig; Vijaya M. Joshi; Mayte Figueroa; Jean A. Ballweg; Thomas K. Chin

Objectives: Incisions in the left ventricle have previously been associated with increased mortality and morbidity, particularly in infants. In order to determine whether this assumption is still true in the current era, we reviewed our recent experience with apical left ventriculotomy in neonates and infants. Methods: The records of five consecutive patients requiring a left ventriculotomy between 2007 and 2010 were reviewed. Weight and age ranged from 2.6 to 16 kilograms and 5 days to 2 years. The diagnoses were three multiple ventricular septal defects, one rhabdomyoma, and one apical aneurysm. The primary end point was left ventricular ejection fraction, with other end points being intensive care unit length of stay, time to extubation, inotrope requirement, arrhythmias, and mitral valve function. Results: There were no early or late deaths. Although lower than their preoperative values, early postoperative ejection fractions were greater than 50% in all patients. Two patients required no inotropes, and 3 required only minimal support. Hospital length of stay was 9 ± 7 days for multiple ventricular septal defect patients, with intensive care unit stays of 2 to 5 days. There were no postoperative arrhythmias requiring pharmacological therapy, and one patient had a significant reduction in mitral insufficiency postoperatively. Conclusions: Based on our experience, we believe that an apical left ventriculotomy does not significantly impair left ventricular function even in small infants, and is not associated with significant morbidity, based on short-term follow-up. Although the long-term effects are still unknown, early results suggest that a left ventriculotomy may safely be used when alternative approaches are inadequate for complex cardiac defects.

Collaboration


Dive into the Christopher J. Knott-Craig's collaboration.

Top Co-Authors

Avatar

T.K. Susheel Kumar

University of Tennessee Health Science Center

View shared research outputs
Top Co-Authors

Avatar

Shyam Sathanandam

University of Tennessee Health Science Center

View shared research outputs
Top Co-Authors

Avatar

Umar S. Boston

Washington University in St. Louis

View shared research outputs
Top Co-Authors

Avatar

Mario Briceno-Medina

University of Tennessee Health Science Center

View shared research outputs
Top Co-Authors

Avatar

Steven P. Goldberg

University of Tennessee Health Science Center

View shared research outputs
Top Co-Authors

Avatar

David Zurakowski

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar

Michael Perez

University of Tennessee Health Science Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Jerry Allen

University of Tennessee Health Science Center

View shared research outputs
Top Co-Authors

Avatar

Mary M. Lane

University of Oklahoma Health Sciences Center

View shared research outputs
Researchain Logo
Decentralizing Knowledge