PubMed Health⌕ Search

Biomedical subjects

C Tchervenkov

Publications and source records attributed to C Tchervenkov.

13 recordsLinked to original sources
PubMed2004

The Aristotle score: a complexity-adjusted method to evaluate surgical results.

OBJECTIVES: Quality control is difficult to achieve in Congenital Heart Surgery (CHS) because of the diversity of the procedures. It is particularly needed, considering the potential adverse outcomes associated with complex cases. The aim of this project was to develop a new method based on the complexity of the procedures. METHODS: The Aristotle project, involving a panel of expert surgeons, started in 1999 and included 50 pediatric surgeons from 23 countries, representing the EACTS, STS, ECHSA and CHSS. The complexity was based on the procedures as defined by the STS/EACTS International Nomenclature and was undertaken in two steps: the first step was establishing the Basic Score, which adjusts only the complexity of the procedures. It is based on three factors: the potential for mortality, the potential for morbidity and the anticipated technical difficulty. A questionnaire was completed by the 50 centers. The second step was the development of the Comprehensive Aristotle Score, which further adjusts the complexity according to the specific patient characteristics. It includes two categories of complexity factors, the procedure dependent and independent factors. After considering the relationship between complexity and performance, the Aristotle Committee is proposing that: Performance = Complexity x Outcome. RESULTS: The Aristotle score, allows precise scoring of the complexity for 145 CHS procedures. One interesting notion coming out of this study is that complexity is a constant value for a given patient regardless of the center where he is operated. The Aristotle complexity score was further applied to 26 centers reporting to the EACTS congenital database. A new display of centers is presented based on the comparison of hospital survival to complexity and to our proposed definition of performance. CONCLUSION: A complexity-adjusted method named the Aristotle Score, based on the complexity of the surgical procedures has been developed by an international group of experts. The Aristotle score, electronically available, was introduced in the EACTS and STS databases. A validation process evaluating its predictive value is being developed.

Cardiac Surgical Procedures↗
PubMed2001

Association between electroencephalographic findings and neurologic status in infants with congenital heart defects.

Neurologic status is of concern in infants with congenital heart defects undergoing open heart surgery. The association between perioperative electroencephalography (EEG) with acute neurologic status and subsequent outcome was examined in a cohort of 60 infants. Preoperative EEG and neurologic examinations were performed within 1 to 2 days prior to surgery (n = 27) and postoperatively (n = 47). Prior to surgery, 15 of 27 infants had normal EEG, whereas 5 had epileptiform activity and 9 had disturbances in background activity that were primarily moderate (8/9) and diffuse (7/9). Postoperatively, only 17 of 47 infants had normal recordings. Newborns (<1 month) were more likely (P< .001) to demonstrate EEG abnormalities than infants. Epileptiform activity was documented in 15, whereas 28 had background abnormalities that were moderate-severe (22/28) and diffuse (20/28) in most. Epileptiform activity prior to surgery was always associated with an abnormal neurologic examination, and this association persisted postoperatively (86%). Moderate to severe background abnormalities in the postoperative EEG was also strongly associated with acute neurologic abnormalities (93%). Severe background abnormalities (n = 5) were 100% predictive of death or severe disability. Long-term follow-up revealed that all children with normal postoperative EEGs had positive neurologic outcomes (P = .04); however, there were many false positives. Perioperative EEG abnormalities increased the likelihood for acute neurologic findings, whereas normal recordings following surgery were reassuring with regard to a favorable outcome.

Cardiovascular Surgical Procedures↗
PubMed2001

Functional limitations in young children with congenital heart defects after cardiac surgery.

UNLABELLED: With the recent dramatic decline in mortality rates of infants undergoing open-heart surgery (OHS), there is growing concern regarding neurodevelopmental sequelae. Outcome studies have primarily focused on delineating developmental impairments; however, the impact on function and family burden has not been investigated. The objective of this study was to determine the prevalence of functional limitations and burden of care of young children with congenital heart defects (CHD) after OHS. STUDY DESIGN: One hundred thirty-one eligible infants with CHD undergoing their first OHS were recruited prospectively. Patients were assessed pre- and postoperatively, and again 12 to 18 months after surgery. Functional assessments included the WeeFIM (Functional Independence Measure) and the Vineland Adaptive Behavior Scale. RESULTS: For the WeeFIM, mean quotients were 84.3 +/- 23.8 (self-care), 77.2 +/- 30.0 (mobility), and 92.4 +/- 27.8 (cognition), with an overall quotient of 83.8 +/- 23.4. Only 21% of the cohort was functioning within their expected age range. Moderate disability was noted in 37%, while only 6% demonstrated a severe disability. For the Vineland scale, mean score for daily living skills was 84.4 +/- 17.6, and 80.3 +/- 15.9 for socialization. Functional difficulties in daily living skills were documented in 40%, whereas >1/2 had poor socialization skills. Factors enhancing risk for functional disabilities included perioperative neurodevelopmental status, microcephaly, length of deep hypothermic circulatory arrest, length of stay in the intensive care unit, age at surgery, and maternal education. CONCLUSIONS: The high prevalence of functional limitations and dependence in activities of daily living is currently underappreciated in the clinical setting, and deserves additional attention by pediatricians and developmental specialists.

Activities of Daily Living↗
PubMed2000

Neurodevelopmental status of newborns and infants with congenital heart defects before and after open heart surgery.

BACKGROUND: Neurodevelopmental disabilities in children with congenital heart defects (CHDs) have been primarily attributed to intraoperative events without consideration of preoperative and postoperative factors. OBJECTIVE: To describe the preoperative and postoperative neurodevelopmental status of newborns and infants with CHDs. STUDY DESIGN: One hundred thirty-one children (56 newborns and 75 infants) were evaluated before and after surgery by using standardized neurobehavioral (newborn) and motor assessments (infant) and neurologic examinations. RESULTS: In newborns, neurobehavioral abnormalities were documented in >50% before surgery, with abnormalities persisting in most after surgery. In infants, neurodevelopmental abnormalities were observed in 38% before surgery. There was a significant association between preoperative and postoperative neurodevelopmental status, with status remaining unchanged in most. Newborns with acyanotic heart lesions were more likely to demonstrate neurologic compromise than those with cyanotic defects. For infants, arterial oxygen saturations <85% were significantly associated with an abnormality. There was a trend for a longer circulatory arrest time to be associated with greater risk for neurologic sequelae in newborns, whereas prolonged cardiopulmonary bypass was an important risk factor for infants. CONCLUSIONS: Neurodevelopmental abnormalities are common in young infants with CHDs and are often present before open heart surgery. These developmental concerns are clinically underappreciated. Early systematic developmental screening may be warranted in this population of interest.

Cardiac Surgical Procedures↗
PubMed2000

Clips versus suture technique: is there a difference?

INTRODUCTION: Coronary artery bypass grafting (CABG) is one of the most common procedures performed today, and wound complications are a major source of morbidity and cost. OBJECTIVE: To determine whether there is any difference in wound outcome (including cost in a Canadian context) between a subcuticular suture technique and skin stapling technique for closure of sternal and leg incisions in CABG patients. PATIENTS AND METHODS: One hundred and sixty-two patients undergoing CABG were prospectively, randomly placed to have their sternal and leg incisions closed with either a subcuticular suture technique or with a skin clip. Data were obtained through chart review, in-hospital assessments and follow-up visits. Nonblinded assessments were made regarding wound leakage, inflammation, infection, necrosis, swelling, dehiscence and cosmesis. Each of the parameters was graded on a scale from 1 to 4. The cost was evaluated in Canadian dollars. RESULTS: There were trends toward increased rates of in-hospital sternal (P=0.09) and leg (P=0.17) incision inflammation when the wounds were closed with skin clips. There was a significantly greater (P=0.05) rate of sternal wound infection with clips, as well as a tendency (P=0.15) toward a greater rate of mediastinitis at follow-up assessment. Cosmetic outcome was similar for both groups. The cost incurred was significantly greater when skin clips were used for closure. There was a greater than threefold difference, which translates to a greater than $10,000 difference over one year. CONCLUSIONS: Closure with a subcuticular technique achieves better outcomes than the use of skin clips. When factoring in the increased cost incurred by using clips, as well as other intangible factors such as surgical skill acquisition, subcuticular suture closure appears to be a favourable method of wound closure in CABG patients compared with the use of skin stapling techniques.

Aged↗
PubMed1999

Multimodality evoked potential findings in infants with congenital heart defects.

Evoked potentials are sensitive prognostic tools in young infants at risk for developmental disability. The objective of this prospective study was to determine whether infants with congenital heart defects demonstrate evoked potential abnormalities prior to or following open heart surgery, and to examine the association between these abnormalities and developmental status 1 year following surgery. A consecutive series of newborns (less than 1 month old) and infants (1 month to 2 years old) were recruited. Somatosensory and brain stem auditory evoked potentials were carried out before or after cardiac surgery, or both. One year later, neurologic examination and standardized measures of motor performance and functional independence were carried out. Twenty-seven newborns and 31 infants underwent perioperative somatosensory evoked potential recordings. Results indicate that perioperative somatosensory evoked potential abnormalities were common in newborns (41%) but not in infants (13%) with congenital heart defects. Brainstem conduction times were within normal limits in all subjects; however, 32% presented with mild elevations in hearing thresholds. All newborns with abnormal somatosensory evoked potentials had abnormal neurologic examinations both perioperatively and again 1 year after open heart surgery. Moreover, standardized developmental assessments 1 year following surgery indicate that all newborns with somatosensory evoked potential abnormalities had developmental deficits in one or more domains. Somatosensory evoked potential abnormalities in the perioperative period are common in newborns with congenital heart defects, and are strongly predictive of persistent developmental delay later.

Brain↗
PubMed1999

Neurologic status of newborns with congenital heart defects before open heart surgery.

UNLABELLED: Controversy exists regarding the integrity of the nervous system in the newborn with a congenital heart defect who must undergo corrective or palliative open heart surgery. Neurodevelopmental sequelae have been primarily attributed to surgical procedures without standardized evaluation of the preoperative neurologic status. OBJECTIVE: To determine whether newborns with congenital heart defects demonstrate abnormalities in neurobehavioral status before surgery. STUDY DESIGN: In this prospective study, a standardized neonatal neurobehavioral assessment and a neurologic examination were conducted independently in a consecutive series of 56 neonates referred to our hospital for investigation of open heart surgery. RESULTS: Neurobehavioral and neurologic abnormalities were documented in greater than half of the cohort and included hypotonia, hypertonia, jitteriness, motor asymmetries, and absent suck. Poor state regulation (62%) and feeding difficulties (34%) also were commonly observed. Furthermore, 3 subjects had seizures, 35.7% were microcephalic, and 12.5% were macrocephalic. The overall likelihood of neurobehavioral abnormalities was not enhanced by indicators of cardiorespiratory compromise. Interestingly, newborns with acyanotic congenital heart defects were more likely to demonstrate neurologic compromise than were those with cyanotic defects. CONCLUSIONS: Findings suggest that the prevalence of neurobehavioral abnormalities before surgery in newborns with congenital heart defects has been underappreciated and would indicate that factors other than intraoperative procedures should be considered in the genesis of brain injury in this population.congenital heart defects, neurologic examination, newborn.

Heart Defects, Congenital↗
PubMed1994

The enigma of myocardial preconditioning models.

Myocardial preconditioning has been reported in the hearts of many species of animals, including dogs, pigs, rabbits, rats, and anecdotally in humans. However, most studies were carried out in the regional ischemic model, although protection against global ischemic injury had been observed in rat models. Besides biochemical endpoints, the criterion of protection in regional ischemia was usually reduction in infarct size, while in global ischemia, recovery of contractile force and time-to-onset of ischemic contracture were used. We attempted to reproduce preconditioning of myocardium against global ischemic injury using an isolated perfused rabbit heart model with the rationale that global ischemia is more relevant to cardiac surgery, the rabbit model is logistically convenient, and it can be used for future comparison with the responses in immature hearts. The preconditioning was induced with 5 minutes of normothermic global ischemia followed by 10 minutes of reperfusion. The principal ischemic injury lasted 35 minutes, followed by 60 minutes of reperfusion. The control group underwent similar principal ischemic injury and reperfusion but no prior preconditioning ischemia. Results showed that there was no difference between the two groups in left ventricular resting tension, recovery in left ventricular developed pressure, contractility (dP/dt), and rate of relaxation (-dP/dt), nor were there any differences in heart rate and coronary flow rate. The reason for our negative findings is not clear, but if the results are confirmed, it will suggest that extrapolation of observations obtained from one experimental model to another should be made with caution.

Animals↗
PubMed1992

Unique responses of immature hearts to ischemia. Functional recovery versus initiation of contracture.

The characterization of unique responses of immature hearts to ischemic injury is important in devising better methods of myocardial protection for neonatal cardiac operations. Two end-points used to assess the vulnerability of immature myocardium to ischemic injury, namely, the time between onset of ischemia to the beginning of contracture and the functional recovery after reperfusion, had yielded results that appeared to be contradictory. In this study both the immature and adult rabbit hearts were used to study these two end-points in the same model, to assess their relationships and physiologic implications. Our data confirmed that, although immature hearts have greater capacity than adult hearts for functional recovery after identical periods of ischemic insult, their times to ischemic contracture are not prolonged, as could have been expected. A negative correlation between the rise in resting myocardial tension (i.e., contracture) and the recovery of ventricular function after reperfusion was noted both in the neonatal and in the adult hearts. However, reperfusion undertaken after "the onset of contracture" showed that the ventricle could still regain a measure of its function, which indicates that the "irreversibility" in global ventricular function is a gradual and progressive phenomenon. Biochemical studies of sarcoplasmic reticular calcium-adenosinetriphosphatase activity indicated that the immature myocardium has a significantly lower activity of this enzyme. Further depression of this enzyme activity after ischemia is seen in the immature hearts and may in part explain the earlier onset of contracture reported. A unifying concept to explain these unique responses of neonatal hearts to ischemia is proposed, based on the immaturities of certain key enzymes. The implications of these findings in the development of better protective techniques are also discussed.

Adenosine Triphosphate↗
PubMed1992

Dynamic cardiomyoplasty for hemodynamic support during acute pulmonary hypertension. An experimental study.

The efficacy of dynamic cardiomyoplasty for hemodynamic support during acute pulmonary hypertension was studied. Five dogs underwent a right latissimus dorsi cardiomyoplasty. Each dog was later studied in a short-term experiment. A graded acute pulmonary hypertension was induced by infusion of glass microspheres into the pulmonary artery. This resulted in decrease in pulmonary artery flow, systemic pressure, and systemic flow. The cardiomyoplasty was then stimulated with a new R wave synchronous rate-responsive pulse-train stimulator (Prometheus system). This pacemaker delivers a pulse train with the duration of stimulation determined as a proportion of the RR interval. At an optimal level of hemodynamic impairment, the dynamic cardiomyoplasty was able to immediately improve pulmonary artery flow 26.4% +/- 5.84% (standard error of the mean) (p less than 0.005, paired t test), mean systemic arterial pressure 11.6% +/- 3.7% (p less than 0.05), and thoracic aortic flow 15.7% +/- 6.3% (p less than 0.05). The degree of improvement in hemodynamic variables could be correlated with the magnitude of hemodynamic impairment present (e.g., r = 0.78; p less than 0.005 for pulmonary blood flow). We conclude that a significant beneficial effect of dynamic cardiomyoplasty on hemodynamics in short-term canine pulmonary hypertension is demonstrated in this study. Thus cardiomyoplasty may be useful in patients with right heart failure associated with increased pulmonary vascular resistance.

Acute Disease↗
PubMed1991

Successful treatment of steroid-resistant double-lung allograft rejection with Orthoclone OKT3.

An 18-yr-old woman with cystic fibrosis who received a double-lung transplant developed a severe episode of acute lung rejection. Bronchoalveolar lavage and transbronchial biopsy were used to establish the diagnosis. The rejection was refractory to administration of high-dose pulse steroids. OKT3 therapy was successfully used to reverse this episode. This is the first case report of a steroid-resistant double-lung allograft rejection successfully treated with OKT3.

Adolescent↗
PubMedDate not supplied

Agreement between the neonatal neurological examination and a standardized assessment of neurobehavioural performance in a group of high-risk newborns.

The degree of agreement between the neonatal neurological examination and a standardized neurobehavioural assessment was investigated in a group of 32 newborns with congenital heart defects. A paediatric neurologist performed a neurological examination, and an occupational therapist administered the Einstein Neonatal Neurobehavioural Assessment Scale on all subjects. Both examiners independently evaluated each subject, and were blinded to the diagnosis, to perinatal status and to each other's clinical findings. Statistical analysis demonstrated a significant association between the overall impression between both examiners (p < .0001), with a crude agreement of 96.9%. Sixteen neonates were determined to be normal and 15 abnormal by both examiners, with disagreement in only one subject. Although two distinct approaches were employed in the neurological assessment of high-risk newborns, both assessments evaluate the maturity and integrity of the immature central nervous system. The results demonstrate a strong agreement between these two approaches, suggesting that the neonatal neurological examination is consistent and valid.

Acoustic Stimulation↗