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Christo I Tchervenkov

Publications and source records attributed to Christo I Tchervenkov.

At least 19 recordsLinked to original sources
PubMed2006

What is operative mortality? Defining death in a surgical registry database: a report of the STS Congenital Database Taskforce and the Joint EACTS-STS Congenital Database Committee.

The most concrete and universal outcome measure used in databases, whether governmental, professional society, research, or third-party payer, is operative mortality. To assure congruous data entry by multiple users of The Society of Thoracic Surgeons and the European Association for Cardiothoracic Surgery congenital heart surgery databases, operative mortality must be clearly defined. Traditionally, operative mortality has been defined as any death, regardless of cause, occurring (1) within 30 days after surgery in or out of the hospital, and (2) after 30 days during the same hospitalization subsequent to the operation. Differing hospital practices result in problems in use of the latter part of the definition (eg, the pediatric hospital that provides longer-term care will have higher mortality rates than one which transfers patients to another institution for such care). In addition, because of the significant number of pediatric multiple operation hospitalizations, issues of assignment of mortality to a specific operation within the hospitalization, calculation of operative mortality rates (operation based vs patient admission based), and discharge other than to home must be addressed and defined. We propose refinements to the definition of operative mortality which specifically meet the needs of our professional societies' multi-institutional registry databases, and at the same time are relevant and appropriate with respect to the goals and purposes of administrative databases, government agencies, and the general public.

Cardiac Surgical Procedures↗
PubMed2006

Report of the 2005 STS Congenital Heart Surgery Practice and Manpower Survey.

BACKGROUND: Limited information is available concerning the congenital heart surgery workforce in North America. To obtain reliable data, The Society of Thoracic Surgeons (STS) Workforce on Congenital Heart Surgery undertook a subspecialty focused survey. METHODS: Preliminary research of websites and databases revealed a potential target group of 263 congenital heart surgeons, including 248 surgeons at 121 US centers and 15 at eight Canadian sites. Surveys were sent to these, plus any additional individuals who listed an interest in congenital or pediatric heart surgery on CTSNet or STS websites. Responders include active congenital heart surgeons, inactive, or retired surgeons, adult cardiac surgeons, and surgeons in training. Analysis is based exclusively on the responses of 217 active congenital heart surgeons (>80% of target). RESULTS: Average age was 48.3 +/- 8.3 years (range, 33 to 78). Ten were female (5%), 207 male (95%). American Medical School graduates were 170 (79%), with 9.2 +/- 1.6 years of postgraduate training. Eighty-five percent are Thoracic Board certified. Congenital heart surgery training outside the United States or Canada was obtained by 29 (14%). One hundred twenty-eight (59%) do exclusively congenital heart surgery. One third perform fewer than 100 congenital cases per year, one third perform 100 to 199, and one third perform 200 or more. Congenital heart surgeons have been in their current positions for 9.5 +/- 8.2 years. Eleven are in their first year of practice. Mean anticipated years to retirement is 15.7 +/- 7.5 (range, 1 to 34). Three anticipate retirement within 1 year. At the same time, 39 fellows will complete postgraduate training at 28 centers this year, and 19 will seek positions in North America. CONCLUSIONS: These data should help to facilitate rational plans to meet manpower needs, including evolving policies concerning training and certification.

Adult↗
PubMed2006

The nomenclature, definition and classification of hypoplastic left heart syndrome.

The hypoplastic left heart syndrome encompasses a spectrum of cardiac malformations that are characterized by significant underdevelopment of the components of the left heart and the aorta, including the left ventricular cavity and mass. At the severe end of the spectrum is found the combination of aortic and mitral atresia, when the left ventricle can be close to non-existent. At the mild end are the patients with hypoplasia of the aortic and mitral valves, but without intrinsic valvar stenosis or atresia, and milder degrees of left ventricular hypoplasia. Although the majority of the patients are suitable only for functionally univentricular repair, a small minority may be candidates for biventricular repair. The nature of the syndrome was a topic for discussion at the second meeting of the International Working Group for Mapping and Coding of Nomenclatures for Paediatric and Congenital Heart Disease, the Nomenclature Working Group, held in Montreal, Canada, over the period January 17 through 19, 2003. Subsequent to these discussions, the Nomenclature Working Group was able to create a bidirectional crossmap between the nomenclature initially produced jointly on behalf of the European Association for Cardio-Thoracic Surgery and the Society of Thoracic Surgeons, and the alternative nomenclature developed on behalf of the Association for European Paediatric Cardiology. This process is a part of the overall efforts of the Nomenclature Working Group to create a comprehensive and all-inclusive international system of nomenclature for paediatric and congenital cardiac disease, the International Paediatric and Congenital Cardiac Code. In this review, we discuss the evolution of nomenclature and surgical treatment for the spectrum of lesions making up the hypoplastic left heart syndrome and its related malformations. We also present the crossmap of the associated terms for diagnoses and procedures, as recently completed by the Nomenclature Working Group.

Diagnosis, Differential↗
PubMed2005

Initial application in the STS congenital database of complexity adjustment to evaluate surgical case mix and results.

BACKGROUND: The analysis of the second harvest (1998-2001) of the Society of Thoracic Surgeons Congenital Heart Surgery Database included the first attempt by the STS to apply a complexity-adjustment method to evaluate congenital heart surgery results. METHODS: This data harvest represents the first STS multiinstitutional experience with software utilizing the international nomenclature and database specifications adopted by the STS and the European Association for Cardio-Thoracic Surgery (April 2000 Annals of Thoracic Surgery) and the first STS Congenital Database Report incorporating a methodology facilitating complexity adjustment. This methodology, allowing for complexity adjustment, gives each operation a basic complexity score (1.5 to 15) and level (1 to 4) based upon the work of the EACTS-STS Aristotle Committee, a panel of 50 expert surgeons. The complexity scoring, based on the primary procedure (from the EACTS-STS International Nomenclature Procedures Short List), estimates complexity through three factors: mortality potential, morbidity potential, and technical difficulty. RESULTS: This STS harvest includes data from 16 centers reporting 12,787 cases, with discharge mortality known for 10,246 cases. The basic complexity score has been applied to the outcomes analysis of these cases and a new equation has been proposed to evaluate one aspect of performance: Aristotle Performance Index = Outcome x Complexity = (Survival) x (Mean Complexity Score) CONCLUSIONS: The complexity analysis represents a basic complexity-adjustment method to evaluate surgical results. Complexity is a constant precise value for a given patient at a given point in time; performance varies between centers. Future STS congenital data harvests will incorporate a second step, the Comprehensive Aristotle Score, utilizing additional patient specific complexity modifiers to allow a more precise complexity adjustment.

Databases, Factual↗
PubMed2005

Current status of the European Association for Cardio-Thoracic Surgery and the Society of Thoracic Surgeons Congenital Heart Surgery Database.

BACKGROUND: After utilizing separate congenital databases in the early 1990s, the Society of Thoracic Surgeons (STS) and the European Association for Cardio-Thoracic Surgery (EACTS) collaborated on several joint database initiatives. METHODS: In 1998, the joint EACTS-STS International Congenital Heart Surgery Nomenclature and Database Project Committee was created and a common nomenclature and common core minimum database dataset were adopted and published by the STS and the EACTS. In 1999, the joint EACTS-STS Aristotle Committee was created and the Aristotle Score was adopted and published as a method to provide complexity adjustment for congenital heart surgery. Collaborative efforts involving the EACTS and STS are underway to develop mechanisms to verify data completeness and accuracy. RESULTS: Since 1998, this nomenclature, database, and methodology of complexity adjustment have been used by both the STS and EACTS to analyze outcomes of over 40,000 patients. A huge amount of data have been generated which allow comparison of practice patterns and outcomes analysis between Europe and North America. The aggregate data from the first 5 years of data collection not only make for interesting comparison but also allow examination of regional difference in practice patterns. For example, in the EACTS, out of 4,273 neonates, 885 (20.7%) underwent arterial switch procedures and 297 (6.95%) underwent Norwood stage 1 procedures. In the STS, out of 3,988 neonates, 472 (11.8%) underwent arterial switch procedures and 575 (14.4%) underwent Norwood stage 1 procedures. CONCLUSIONS: This analysis of the EACTS-STS multi-institutional outcomes database confirms that in both Europe and North America, case complexity and mortality is highest among neonates, then infants, and then children. Regional differences in practice patterns are demonstrated, with the overall goal being the continued upgrade in the quality of surgery for congenital heart disease worldwide.

Databases, Factual↗
PubMed2005

Risk factors associated with mortality and interventions in 472 neonates with interrupted aortic arch: a Congenital Heart Surgeons Society study.

OBJECTIVE: We sought to determine the prevalence of outcomes and associated patient and management factors for neonates with interrupted aortic arch. METHODS: From 1987 to 1997, a total of 472 neonates were enrolled prospectively from 33 institutions. Competing risks methodology was used to determine simultaneous risk and associated incremental risk factors for death, initial and subsequent left ventricular outflow tract procedures, and arch reinterventions. RESULTS: Overall survival was 59% at 16 years after study entry but improved with successive birth cohort. In general, risk factors for death in each of the competing risks analyses included lower birth weight, younger age at study entry, type B interrupted aortic arch, and major associated cardiac anomalies. Of 453 patients who had interrupted aortic arch repair, after 16 years 33% had died and 28% had undergone an arch reintervention. Reintervention was more likely for those who had truncus arteriosus repair, interrupted aortic arch repair by a method other than direct anastomosis with patch augmentation, and the use of polytetrafluoroethylene as either an interposition graft or a patch. From study entry, competing risks after 16 years showed that 28% had died and 34% had undergone an initial left ventricular outflow tract procedure. Initial left ventricular outflow tract procedure was more likely for those with single ventricle, type B interrupted aortic arch, bicuspid aortic valve, or anomalous right subclavian artery. Among those who had undergone an initial left ventricular outflow tract procedure, after 16 years 37% had died and 28% had undergone a second procedure. CONCLUSION: Anatomic features affect mortality and initial left ventricular outflow tract procedures, whereas characteristics of the arch repair affect arch reintervention.

Aortic Arch Syndromes↗
PubMed2005

Interrupted aortic arch: surgical decision making.

Interrupted aortic arch (IAA) is defined as the loss of luminal continuity between the ascending and descending aorta. It is associated with a multitude of lesions ranging from isolated ventricular septal defects to complex ones. Although results have improved in the modern era, repair of IAA is associated with a significant mortality and morbidity. In recent years, the move to a one-stage repair has become well established, and the optimal technique for aortic repair seems to be partial direct anastomosis with patch augmentation. Left ventricular outflow tract obstruction (LVOTO) continues to be an important factor affecting survival and re-intervention rates after IAA repair. Great variability exists with regard to definition and diagnosis of LVOTO. To guide the decision for left ventricular outflow tract (LVOT) intervention and which type to use, we propose a simple formula based on the baby's weight. We advocate a conservative approach when the LVOT diameter is greater than the baby's weight + 2 mm and a LVOT bypass procedure (Yasui or Norwood) if the LVOT diameter is less than the baby's weight in millimeters. If the LVOT diameter falls in between, no definitive recommendation can be made, and the surgical approach is based on the surgeon's experience and overall philosophy.

Aorta, Thoracic↗
PubMed2004

Lessons learned from the data analysis of the second harvest (1998-2001) of the Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database.

OBJECTIVE: The analysis of the second harvest of the STS Congenital Heart Surgery Database produced meaningful outcome data and several critical lessons relevant to congenital heart surgery outcomes analysis worldwide. METHODS: This data harvest represents the first STS multi-institutional experience with software utilizing the nomenclature and database requirements adopted by the STS and EACTS (April 2000 Annals of Thoracic Surgery). Members of the STS Congenital Heart Committee analyzed the STS data. RESULTS: This STS harvest includes data from 16 centers (12787 cases, 2881 neonates, 4124 infants). In 2002, the EACTS reported similar outcome data utilizing the same database definitions (41 centers, 12736 cases, 2245 neonates, 4195 infants). Lessons from the analysis include: (1) Death must be clearly defined. (2) The Primary Procedure in a given operation must be documented. (3) Inclusionary and exclusionary criteria for all diagnoses and procedures must be agreed upon. (4) Missing data values remain an issue for the database. (5) Generic terms in the nomenclature lists, that is terms ending in Not Otherwise Specified (NOS), are redundant and decrease the clarity of data analysis. (6) Methodology needs to be developed and implemented to assure and verify data completeness and data accuracy. 'Operative Mortality' and 'Mortality Assigned to this Operation' were defined by the STS and EACTS; these definitions were not utilized uniformly. 'Thirty Day Mortality' was problematic because some centers did not track mortality after hospital discharge. Only 'Mortality Prior to Discharge' was consistently reported. Designation of Primary Procedure for a given operation determines its location for analysis. Until Complexity Scores lead to automated methodology for choosing the Primary Procedure, the surgeon must designate the Primary Procedure. Inclusionary and exclusionary criteria for all diagnoses and procedures have been developed in an effort to define acceptable concomitant diagnoses and procedures for each analysis. Improvements in data completeness can be achieved using a variety of techniques including developing more functional techniques of data entry at individual institutions and software improvements. Future versions of the STS Congenital Database will request that the coding of diagnoses and procedures avoid the terms ending in NOS. CONCLUSIONS: Lessons from this data harvest should improve congenital heart surgery outcome analysis.

Databases, Factual↗
PubMed2003

Timing of steroid treatment is important for cerebral protection during cardiopulmonary bypass and circulatory arrest: minimal protection of pump prime methylprednisolone.

OBJECTIVES: The contact of cardiopulmonary bypass surface and patient's blood activates systemic inflammatory response which aggravates ischemia-reperfusion injury. This study evaluates the effects of cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA) on cerebral protection using different steroid administration protocols. METHODS: Eighteen (n=6/group) 4 week-old piglets were divided in three groups. Methylprednisolone (30 mg/kg) was administered intravenously 4 h prior to CPB in Group I, or added in pump prime in group II. Group III received no steroid. All animals were cooled to 15 degrees C followed by 100 min of DHCA, then rewarmed over 40 min and sacrificed 6 h after CPB. Post-operative weight gain, bioelectrical impedance, colloid oncotic pressure (COP) and interleukin-6 (IL-6) were evaluated. Determination of cerebral trypan blue and immunohistochemical assays of transforming growth factor (TGF)-beta1 and caspase-3 activities were performed. RESULTS: Post-operative % weight gain (13.0+/-3.8 (I) versus 26.4+/-9.9 (II) versus 22.6+/-6.4 (III), P=0.02); % bioimpedance reduction (14.5+/-8.0 (I) versus 38.3+/-13.3 (II) versus 30.5+/-8.0 (III), P=0.003); mean COP (mmHg) (14.9+/-1.8 (I) versus 10.9+/-2.0 (II) versus 6.5+/-1.8 (III), P=0.0001) and systemic IL-6 levels (pg/ml) (208.2+/-353.0 (I) versus 1562.1+/-1111.4 (II) versus 1712.3+/-533.2 (III), P=0.01) were significantly different between the groups. Spectrophotometric analysis of cerebral trypan blue (ng/g dry weight) was significantly different between the groups (0.0053+/-0.0010 (I) versus 0.0096+/-0.0026 (II) versus 0.0090+/-0.0019 (III), P=0.004). TGF-beta1 scores were 3.3+/-0.8 (I) versus 1.5+/-0.8 (II) versus 1.5+/-0.5 (III), P<0.05, groups I versus II and I versus III. Remarkable perivascular caspase-3 activity was observed in groups II and III. CONCLUSION: Different timing of steroid administration results in different inflammatory mediator response. Steroid in CPB prime is not significantly better than no steroid treatment, while systemic steroid pre-treatment significantly decreases systemic manifestation of inflammatory response and brain damage.

Animals↗