Physiological illness severity, technical performance (residual lesion scores), case complexity, risk stratification and clinical outcomes in pediatric cardiac surgery

Introduction:
Clinical outcomes in pediatric cardiac surgery depend on multiple factors, including case complexity, preoperative baseline physiology, intra-operative course, surgical technical performance, and postoperative care. Our objective was to evaluate surgical technical performance as measured by residual lesion scores, as a predictor of clinical outcomes in a risk-stratified manner, and its interplay with physiologic illness severity.
Methods:
Technical performance was defined as “the adequacy of the intended anatomic surgical repair”. We quantitatively assessed technical performance using a scoring system of postoperative residual lesions. Specifically, we graded each sub-procedure of an operation using pre- discharge echocardiogram and the need for postoperative re-intervention. Three technical performance score (TPS) classes were defined: Class 1, optimal, no residual lesions detected; Class 2, adequate, mild residual lesions; and Class 3, inadequate, significant residual lesions or the need for re-intervention to correct them. The interplay of TPS with the pre- and postoperative physiologic illness severity as measured by Pediatric Risk of Mortality (PRISM) III scores was examined across a broad spectrum of pediatric cardiac surgery operations in neonates and infants. The association of TPS with early and midterm outcomes was assessed.
Results:
Technical performance scoring criteria were created for more than 90% of all congenital cardiac operations. TPS was the most important factor in determining early clinical outcomes in complex neonatal and a wide range of infant cardiac repairs, with optimal TPS attenuating the effects of high case complexity and poor preoperative physiologic illness severity. Clinical outcomes were unaffected by intra-operative surgical revisions, provided the final TPS was at least adequate. TPS predicted early and midterm outcomes and the need for unplanned future re-interventions. In addition, early postoperative physiologic illness severity, as measured by PRISM III scores, showed a strong association with hospital mortality, postoperative re-interventions, poor technical performance, and major postoperative complications in complex neonatal cardiac procedures.
Conclusions:
TPS emerged as an important predictor of outcomes across a range of ages and disease complexity and can serve as an important tool for self-assessment and quality improvement. The association of TPS with early and midterm survival and the need for unplanned future re-interventions can be used to prospectively identify patients at ongoing risk of mortality. Early postoperative physiologic illness severity as measured by PRISM III may be used as an early surrogate of TPS to initiate a search for and correction of technical deficiencies.
The impact of TPS on other subtle outcomes, such as patient neurodevelopment and healthcare costs, will need to be further investigated. The expansion of this quality initiative to other centers to revalidate our observations and further refine the technical performance scoring system based on prospective multi-center studies will form the basis of future studies with potential benefits to patients. Surgical competency also encompasses other non-technical skills such as situational awareness, leadership, and team interaction, each of which may also contribute to outcomes and should be taken into consideration.
The nomenclature of TPS was subsequently changed to Residual Lesion Scores (RLS) to indicate that measures of adequacy of the anatomic repair are better reflected by the term residual lesions initially referred to as technical performance.