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S Bert Litwin

Publications and source records attributed to S Bert Litwin.

13 recordsLinked to original sources
PubMed2006

Near infrared spectroscopy monitoring during pediatric aortic coarctation repair.

BACKGROUND: Near infrared spectroscopy (NIRS) measures regional tissue oxygenation continuously and noninvasively and may allow assessment of changes in regional perfusion in real time. METHODS: We used NIRS monitoring to track real-time changes in regional oxygenation (rSO2) above and below the aortic cross-clamp in patients undergoing aortic coarctation repair and routinely stored these data in an operative electronic data base. This allowed us to analyze the changes in rSO2 during aortic coarctation repair for three pediatric age groups (neonates, infants <1 year, and children >1 year). Two site [cerebral (rSO2-C) and somatic thoracodorsal (rSO2-S)] rSO2 monitoring was performed in patients undergoing aortic coarctation repair. Data for rSO2 were analyzed across sites and age groups before, during and after cross-clamp. RESULTS: Twenty-six patients were available for analysis (11 neonates, 5 infants and 10 children). The regional oxygenation below the cross clamp (rSO2-S) declined significantly in all three age groups, but the decrease in neonates and infants <1 year of age was significantly greater than in the older children. CONCLUSIONS: Monitoring rSO2-S provides real-time trend information of regional oxygenation below the aortic cross-clamp. The decline in rSO2-S during aortic cross-clamp was rapid and large in most neonates and young infants <1 year which suggests impairment of regional perfusion presumably because of a lack of adequate collateral circulation to the monitored regional tissue. In contrast, the rSO2-S changed only to a minor degree in most infants and children >1 year, possibly because they had time to develop a more adequate collateral circulation around incomplete aortic obstruction.

Adolescent↗
PubMed2005

Complex aortic valve repair as a durable and effective alternative to valve replacement in children with aortic valve disease.

OBJECTIVE: This study was undertaken to determine the utility of aortic valve repair in children. METHODS: A retrospective analysis was conducted on aortic valve surgery from 1973 to 2004 at Children's Hospital of Wisconsin. RESULTS: Procedures were classified as simple repairs (blunt valvotomy, commissurotomy with or without thinning, n = 147), repair of aortic insufficiency with ventricular septal defect (n = 22), complex repairs (any combination of additional procedures including suspension of prolapsed leaflets, leaflet extensions, repair of torn or perforated leaflets, annuloplasty, reduction of sinus of Valsalva plasty, and concomitant repair of supravalvular or subvalvular stenosis, n = 57), and replacements (n = 57, 20 mechanical, 2 porcine, and 35 human valves). Freedoms from reintervention for simple repairs and repair of aortic insufficiency with ventricular septal defect at 10 years were 86% +/- 5% and 93.3% +/- 6%, respectively. For complex valve repair, freedoms from reintervention at 1, 5, and 10 years were 94% +/- 3%, 85% +/- 6%, and 44% +/- 15%, versus 96% +/- 3%, 77% +/- 9%, and 77% +/- 9% for valve replacement ( P = .3). At intermediate follow-up, patients with complex valve repair had a residual gradient of 20 +/- 21 mm Hg, and 94% were free of severe aortic insufficiency. Residual aortic stenosis ( P < .05) but not the preoperative diagnosis of combined aortic stenosis and insufficiency predicted the need for reintervention. CONCLUSION: Freedom from reintervention after complex valve repairs was not different from that after valve replacement, with acceptable residual aortic stenosis and insufficiency. Simple repairs and repair of aortic insufficiency with ventricular septal defect yielded excellent long-term freedom from reintervention.

Adolescent↗
PubMed2005

Aortic valve repair.

Aortic valve replacement options are limited in children, and all of them have disadvantages. Aortic valve repair techniques have evolved slowly and have not gained wide acceptance; however, large series using a variety of techniques demonstrate that valve repair is possible with excellent early hemodynamics and satisfactory intermediate durability. The results of aortic valve repair at the Children's Hospital of Wisconsin are presented. Simple repairs (blunt valvotomy, commissurotomy, or commissurotomy with leaflet thinning) directed at congenital aortic stenosis resulted in 86% +/- 5% freedom from reintervention at 10 years. Repair of aortic insufficiency with ventricular septal defect (VSD) resulted in 93.3% +/- 6% freedom from reoperation at 10 years. Complex repairs included a combination of techniques and yielded 5-year freedom from reintervention of 83% +/- 7% compared with 73% +/- 11% for patients undergoing aortic valve replacement (P = .62). Aortic valve repair provides an alternative to aortic valve replacement in selected patients. The utility of aortic valve repair and aortic valve replacement must be measured not only in freedom from reintervention but also in regression of left ventricular mass and exercise testing. Improvement in outcome depends on better patient selection and suitable bioprosthetic materials.

Adolescent↗
PubMed2004

Surgical therapy for sudden cardiac death in children.

Sudden cardiac death (SCD) in children is the result of multiple etiologies and treatment (prophylaxis) must be tailored accordingly. In children who do not have congenital heart disease, surgical therapy of SCD typically consists of implantation of an internal defibrillator, with specific attention to the small size of the patient. In children who have unrepaired congenital heart disease, therapy of SCD is primarily repair of the congenital anomaly. In children or young adults who have previously undergone surgery for congenital heart disease, SCD therapy consists of repair of any residual or acquired structural defect, often in combination with antiarrhythmia surgery or defibrillator implantation.

Arrhythmias, Cardiac↗
PubMed2003

Cellular redistribution of inducible Hsp70 protein in the human and rabbit heart in response to the stress of chronic hypoxia: role of protein kinases,.

Many infants who undergo cardiac surgery have a congenital cyanotic defect where the heart is chronically perfused with hypoxemic blood. Infant hearts adapt to chronic hypoxemia by activation of intracellular protein kinase signal transduction pathways. However, the involvement of heat shock protein 70 in adaptation to chronic hypoxemia and its role in protein kinase signaling pathways is unknown. We determined expression of message and subcellular protein distribution for inducible (Hsp70i) and constitutive heat shock protein 70 (Hsc70) in chronically hypoxic and normoxic infant human and rabbit hearts and their relationship to protein kinases. In chronically hypoxic human and rabbit hearts message levels for Hsp70i were elevated 4- to 5-fold compared with normoxic hearts, Hsp70i protein was redistributed from the particulate to the cytosolic fraction. In normoxic infants Hsp70i protein was distributed almost equally between the cytosolic and particulate fractions. Hsc70 message and subcellular distribution of Hsc70 protein were unaffected by chronic hypoxia. We then determined if protein kinases influence Hsp70i protein subcellular distribution. In rabbit hearts SB203580 and chelerythrine reduced Hsp70i message levels, whereas SB203580, chelerythrine, and curcumin reversed the subcellular redistribution of Hsp70i protein caused by chronic hypoxia, with no effect in normoxic hearts, indicating regulation of Hsp70i message and subcellular distribution of Hsp70i protein in chronically hypoxic rabbit hearts is influenced by protein kinase C and mitogen-activated protein kinases, specifically p38 MAPK and JNK. We conclude the Hsp70 signal transduction pathway plays an important role in adaptation of infant human and rabbit hearts to chronic hypoxemia.

Alkaloids↗
PubMed2002

Improved survival of patients undergoing palliation of hypoplastic left heart syndrome: lessons learned from 115 consecutive patients.

BACKGROUND: Outcome of stage 1 palliation (S1P) for hypoplastic left heart syndrome (HLHS) has improved coincident with application of treatment strategies including continuous superior vena cava oximetry (SvO2), phenoxybenzamine (POB), strategies to minimize the duration of deep hypothermic circulatory arrest (DHCA) and efforts to ameliorate the inflammatory response to cardiopulmonary bypass (CPB) using aprotinin and modified ultrafiltration. METHODS AND RESULTS: Analysis of a consecutive series of 115 patients undergoing S1P was done to identify the risk factors for mortality and the impact of new treatment strategies. For the current era, July 1996 to October 2001, hospital survival was 93% (75/81) compared with 53% (18/34) for the time period, January 1992 to June 1996, P<0.001. Survival to stage 2 palliation (S2P) was also significantly improved in the current era, 81% (66/81) versus 44% (15/34), P<0.01. Anti-inflammatory treatment strategies demonstrated improved survival by univariate analysis (P<0.001). Multivariate analysis identified continuous SvO2 monitoring as a factor favoring S1P survival (P=0.02) and use of POB as a factor favoring survival to S2P (P=0.003). In the current era shorter duration of DHCA was associated with improved survival to S2P (P=0.02). CONCLUSIONS: Improved survival following S1P can be achieved with strategies that allow for early identification of decreased systemic output and the use of afterload reduction to stabilize systemic vascular resistance and therefore the pulmonary to systemic flow ratio. Strategies to ameliorate the inflammatory response to CPB may decrease the degree and duration of postoperative support. Strategies to minimize duration of DHCA may improve intermediate survival and merit additional studies.

Anastomosis, Surgical↗
PubMed2002

Safety of aprotinin use and re-use in pediatric cardiothoracic surgery.

BACKGROUND: Hypersensitivity reactions to aprotinin have been reported in adult cardiac surgical patients undergoing initial and re-exposure to the medication. This study describes the incidence and impact of aprotinin hypersensitivity reactions in children undergoing cardiothoracic surgery. METHODS AND RESULTS: In this retrospective review of our entire experience with aprotinin (n=865), 681 first exposures, 150 second exposures, and 34 third or higher exposures were examined. Reactions were classified as mild (generalized cutaneous erythema, Type A) or severe (unexplained cardiopulmonary instability after aprotinin exposure, Type B). Records of patients sustaining a reaction were reviewed to assess the impact of the reaction on outcome and to survey reaction management strategies. Reactions occurred in 7 of 681 first exposures (1.0%), of which 2 were Type A and 5 were Type B. In second exposures, there were reactions in 2 of 150 (1.3%), of which both were Type B. In 34 third or higher exposures, there was only 1 reaction (2.9%), which was Type B. Reactions were no more likely on second, third, or higher exposure than on initial exposure. Skin testing had a negative predictive value of 98.9% and a positive predictive value of 20%. Anti-aprotinin IgE was undetectable in 7 of 8 reactor cases tested. No adverse sequelae were attributed to aprotinin reaction. CONCLUSIONS: The risk of hypersensitivity reactions to aprotinin is low in children undergoing cardiothoracic surgery, even with multiple exposures to the medication. Reactions are more likely with re-exposure, and risk increases with multiple exposures. Neither skin testing nor assays for IgE identified reactors.

Adolescent↗
PubMed2002

Activation of protein kinases in chronically hypoxic infant human and rabbit hearts: role in cardioprotection.

BACKGROUND: Many infants who undergo heart surgery have a congenital cyanotic defect in which the heart is chronically perfused with hypoxic blood. However, the signaling pathways by which infant hearts adapt to chronic hypoxia and resist subsequent surgical ischemia is unknown. METHODS AND RESULTS: We determined the activation and translocation of protein kinase C (PKC) isoforms and mitogen activated protein kinases (MAP kinases) in 15 infants with cyanotic (SaO2<85%) or acyanotic (SaO2>95%) heart defects undergoing surgical repair and in 80 rabbits raised from birth in a hypoxic (SaO2<85%) or normoxic (SaO2>95%) environment. Tissues from infant human and rabbit hearts were processed for Western and in vitro kinase analysis. In human infants with cyanotic heart defects, PKCepsilon, p38 MAP kinase, and JUN kinase but not p42/44 MAP kinase were activated and translocated from the cytosolic to the particulate fraction compared with acyanotic heart defects. In rabbit infants there was a parallel response for PKCepsilon, p38 MAP kinase, and JUN kinase similar to humans. In infant rabbit hearts inhibition of PKCepsilon with chelerythrine, p38 MAP kinase, with SB203580 and JUN kinase with curcumin abolished the cardioprotective effects of chronic hypoxia but had no effects on normoxic hearts. CONCLUSIONS: Infant human and rabbit hearts adapt to chronic hypoxia through activation of PKCepsilon, p38 MAP kinase, and JUN kinase signal transduction pathways. These pathways may be responsible for cardioprotection in the chronically hypoxic infant rabbit heart.

Activating Transcription Factor 2↗
PubMed1981

Use of activated clotting time for monitoring anticoagulation during cardiopulmonary bypass in infants and children with congenital heart disease.

The use of a fixed dosage schedule was compared with the use of activated clotting time (ACT) for determining heparin and protamine dosages during and after cardiopulmonary bypass disease. Use of the ACT resulted in a statistically significant increase in heparin dosage and a statistically significant reduction of postoperative blood loss. With ACT use, chest tubes were retained for a shorter period of time, and the incidence of serious postoperative hemorrhage was reduced from 44% to 18%. These results confirm the superiority of the ACT method for monitoring intraoperative anticoagulation in pediatric patients with congenital heart disease.

Journal Article↗
PubMed1977

USE OF AN EXTRACARDIAC CONDUIT IN THE REPAIR OF l-TRANSPOSITION WITH l-LOOPING ASSOCIATED WITH SEVERE SUBVALVULAR PULMONIC STENOSIS AND A VENTRICULAR SEPTAL DEFECT.

Total correction was performed in a child with l-transposition of the great arteries, severe subpulmonic stenosis, and a ventricular septal defect. The subpulmonic obstruction was bypassed with an extra-cardiac valved conduit. This alternate method of relieving ventricular outflow obstruction should be considered when conventional techniques cannot be employed because of complex intracardiac anatomy. Proper placement of the pulmonary ventriculotomy is important in order to avoid injury to coronary arteries on the upper and lower ventricular wall and to papillary muscles in the mid-portion of the ventricle.

Journal Article↗
PubMed1975

SURGICAL MANAGEMENT OF A NEONATE WITH INTERRUPTED AORTIC ARCH, TRANSPOSITION OF THE GREAT ARTERIES, AND TRICUSPID ATRESIA.

A critically ill infant presented to our Center with congestive heart failure due to Type A interrupted aortic arch, D-transposition of the great arteries, tricuspid atresia, a large ventricular septal defect, and a closing ductus arteriosus. Partially corrective surgery including aortic arch reconstruction, ductal division, and pulmonary artery banding was successful. Future total correction is planned.

Journal Article↗