Incremental value of the preoperative echocardiogram to predict mortality and major morbidity in coronary artery bypass surgery.

BACKGROUND: Although echocardiography is commonly performed before coronary artery bypass surgery, there has yet to be a study examining the incremental prognostic value of a complete echocardiogram. METHODS AND RESULTS: Patients undergoing isolated coronary artery bypass surgery at 2 hospitals were divided into derivation and validation cohorts. A panel of quantitative echocardiographic parameters was measured. Clinical variables were extracted from the Society of Thoracic Surgeons database. The primary outcome was in-hospital mortality or major morbidity, and the secondary outcome was long-term all-cause mortality. The derivation cohort consisted of 667 patients with a mean age of 67.2±11.1 years and 22.8% females. The following echocardiographic parameters were found to be optimal predictors of mortality or major morbidity: severe diastolic dysfunction, as evidenced by restrictive filling (odds ratio, 2.96; 95% confidence interval, 1.59-5.49), right ventricular dysfunction, as evidenced by fractional area change <35% (odds ratio, 3.03; 95% confidence interval, 1.28-7.20), or myocardial performance index >0.40 (odds ratio, 1.89; 95% confidence interval, 1.13-3.15). These results were confirmed in the validation cohort of 187 patients. When added to the Society of Thoracic Surgeons risk score, the echocardiographic parameters resulted in a net improvement in model discrimination and reclassification with a change in c-statistic from 0.68 to 0.73 and an integrated discrimination improvement of 5.9% (95% confidence interval, 2.8%-8.9%). In the Cox proportional hazards model, right ventricular dysfunction and pulmonary hypertension were independently predictive of mortality over 3.2 years of follow-up. CONCLUSIONS: Preoperative echocardiography, in particular right ventricular dysfunction and restrictive left ventricular filling, provides incremental prognostic value in identifying patients at higher risk of mortality or major morbidity after coronary artery bypass surgery.

Quadricuspid aortic valve: a report of 12 cases and a review of the literature.

Quadricuspid aortic valve (QAV) is rare and its diagnosis, clinical course, and management are less well defined relative to other aortic valve abnormalities. Advances in diagnostic imaging, notably in ultrasound, have increased clinical awareness of this anomaly and prompted this review of our experience with 12 new patients and a compilation of previously reported patients to further characterize this condition.

Prospective, comprehensive assessment of cardiac troponin T testing after coronary artery bypass graft surgery.

BACKGROUND: The significance and clinical role of cardiac troponin testing after coronary artery bypass grafting remain unclear. METHODS AND RESULTS: Cardiac troponin T (cTnT) was measured during the first 24 hours after coronary artery bypass graft surgery in 847 consecutive patients. Only 17 patients (2.0%) had new Q waves or left bundle-branch block after surgery; however, cTnT elevation was observed in nearly all subjects, with a median cTnT concentration of 1.08 ng/mL overall. Direct predictors of postoperative cTnT values included preoperative myocardial infarction (P<0.001), preoperative intraaortic balloon pump (P<0.001), intraoperative/postoperative intraaortic balloon pump (P<0.001), number of distal anastomoses (P=0.005), bypass time (P<0.001), and number of intraoperative defibrillations (P=0.009), whereas glomerular filtration rate (P<0.001), off-pump coronary artery bypass grafting (P=0.003), and use of warm cardioplegia (P=0.02) were inversely associated with cTnT values. A linear association was seen between cTnT levels and length of stay and ventilator hours, and in an analysis adjusted for the Society for Thoracic Surgery Risk Model, cTnT remained independently prognostic for death (odds ratio, 3.20; P=0.003), death or heart failure (odds ratio, 2.04; P=0.008), death or need for vasopressors (odds ratio, 2.70; P<0.001), and the composite of all 3 (odds ratio, 2.57; P<0.001). In contrast to consensus-endorsed cTnT cut points for postoperative evaluation, a cTnT <1.60 ng/mL had a negative predictive value of 93% to 99% for excluding various post-coronary artery bypass graft surgery complications. CONCLUSIONS: cTnT concentrations after coronary artery bypass graft surgery are nearly universally elevated, are determined by numerous factors, and are independently prognostic for impending postoperative complications when used at appropriate cut points.

Aortic dissection and moyamoya disease in Turner syndrome.

Aortic dilation and dissection are well-recognized cardiac abnormalities in women with Turner syndrome (TS), although the underlying pathophysiology is not fully understood. We report on a 46-year-old Hispanic woman who was previously diagnosed with moyamoya disease on magnetic resonance imaging after a presentation with stroke-like symptoms. Her features were consistent with TS and chromosome analysis revealed mosaicism in which 17% of the cells showed a pseudoisodicentric Y chromosome: 45,X (25)/46,X psu idic (Y)(11.2) (5). A preceding screening transthoracic echocardiogram had shown a bicuspid aortic valve (BAV) with an aortic diameter of 3.2 cm; at the time of moyamoya diagnosis, the aorta was 3.5 cm with mild aortic stenosis and mild aortic regurgitation. Four years later, the patient had had an acute aortic dissection, Stanford type A, which was repaired successfully. This case report is the third individual with TS associated with moyamoya disease and the first associated with dissection. The small number of cases does not allow detailed analysis other than noting patient age (two older than 40 years), karyotype (two others associated with isochrome Xq), and associated cardiac risk factors (one with BAV). Although this may be a chance occurrence, we hypothesize that moyamoya disease could be a manifestation of the vasculopathy in TS.

Safety and efficacy of the argatroban therapy during the early post-cardiac surgery period.

Heparin-induced thrombocytopenia (HIT) is associated with a high incidence of vein graft occlusion after cardiac surgery. When HIT is suspected during the post-operative period, current guideline recommends a direct thrombin inhibitor such as argatroban to be started immediately. The aim of this retrospective study was to evaluate the safety and efficacy of argatroban in the early period after cardiac surgery. All patients who received argatroban within 72 h after cardiac surgery from September 2005 to June 2009 from a single center were included. Patient demographics, pre-operative relevant history, intra-operative events and post-operative data were collected and analyzed. The primary endpoints were bleeding, thrombotic complication during or after argatroban administration, and in-hospital mortality. The study population comprised 31 patients administered argatroban within 72 h after cardiac surgery. Argatroban was started a mean of 1.7 days after surgery (median dose, 0.66 µg/kg/min; median duration, 5.9 days). Twenty patients (64.5%) experienced bleeding; episode driven entirely by the need for blood transfusion. No new thromboembolic complication occurred during or after argatroban infusion. One patient died from aspiration pneumonia. Compared to those without bleeding complications, patients who bled had longer operation times and increased use of intra-aortic balloon pump. However, argatroban therapy including the starting time, median dose, infusion duration, and activated partial thromboplastin times showed no difference between the two groups. In cardiac surgery patients with clinical suspicion of HIT, early postoperative use of argatroban seems well-tolerated and associated with a low risk of thrombotic events.

Diagnosis of congenital unicuspid aortic valve in adult population: the value and limitation of transesophageal echocardiography.

BACKGROUND: This study aimed to assess the accuracy of two-dimensional echocardiography (echo) in diagnosing unicuspid aortic valve (UAV) and to determine echo features that could improve the diagnosis. METHOD: We reviewed transthoracic/transesophageal echoes (TTE/TEE) from our hospital database for adult patients who had aortic valve surgery with a preoperative echo diagnosis of UAV or equivocal diagnosis of bicuspid aortic valve (BAV) BAV/UAV. Morphological characteristics of AV and ascending aortic dimensions were evaluated. RESULTS: Nineteen patients were identified, 13 (11 Male, 2 Female, mean age 47 ± 10 years) had surgically confirmed diagnosis of UAV, six had BAV. The incidence of UAV was 2.6%. For diagnosing UAV, the sensitivity and specificity of TTE was 27% and 50% and those of TEE was 75% and 86%, respectively. For TTE, positive predictive value (PPV) was 60% and negative predictive value (NPV) was 20%. By TEE, PPV was 90% and the NPV was 67%. In UAV patients, 85% had severe aortic stenosis (mean gradient 45 ± 16 mmHg, AVA: 0.9 ± 0.2 cm²). 46% had ascending aorta aneurysm (mean aortic root, sinutubular junction, ascending aorta dimensions: 36 ± 3 mm, 31 ± 4 mm and 41 ± 8 mm). Patients with ascending aortic aneurysm were younger (41 ± 11 years vs. 52 ± 5 years, P < 0.05) All UAV were unicommissural with a posteriorly positioned commissural attachment, 69% were heavily calcified. Diagnostic accuracy was limited by quality of images, severity, and distribution of calcification. CONCLUSION: TEE is the diagnostic modality of choice in UAV. Identifying several echo features may improve its diagnostic accuracy.

Impact of cardiac intraoperative precursor events on adverse outcomes.

BACKGROUND: Although extensive study has been directed at the influence of patient factors and comorbidities on cardiac surgical outcomes, less attention has been focused on process. We sought to examine the relationship between intraoperative precursor events (those events that precede and are requisite for the occurrence of an adverse event) and adverse outcomes themselves. METHODS: Anonymous, prospectively collected intraoperative data was merged with database outcomes for 450 patients undergoing major adult cardiac operations. Precursor events were categorized by type, person most affected, severity, and compensation. Number and categories of precursor events were analyzed as predictors of a composite outcome combining death or near miss complications (DNM), using logistic regression. RESULTS: Precursor events occurred more frequently in cases with a DNM outcome than in those with no adverse event (2.7 +/- 2.4 vs 2.0 +/- 2.3/procedure, P = .005). After adjustment for other patient characteristics, the number of precursor events remained an independent predictor of DNM (RR, 1.14 per event [1.04 to 1.24]). Of 990 events, 35.6% related to management, 28.8% were technical, and 22.8% were environment-related. The surgeon was most affected in 40.8%, and 16.5% were of major severity. When categories of precursor events were analyzed, major severity events and those most affecting the surgeon were independent predictors of DNM. CONCLUSIONS: More detailed study of process in complex operations may lead to improved quality of care and patient safety. Special attention must be paid particularly to high risk patients and high risk precursor events.

Prospective assessment of intraoperative precursor events during cardiac surgery.

OBJECTIVE: Increasing attention has been afforded to the ubiquity of medical error and associated adverse events in medicine. There remains little data on the frequency and nature of precursor events in cardiac surgery, and we sought to characterize this. METHODS: Detailed, anonymous information regarding intraoperative precursor events (which may result in adverse events) was collected prospectively from six key members of the operating team during 464 major adult cardiac surgical cases at three hospitals and were analyzed with univariable statistical methods. RESULTS: During 464 cardiac surgical procedures, 1627 reports of problematic precursor events were collected for an average of 3.5 and maximum of 26 per procedure. 73.3% of cases had at least one recorded event. One-third (33.3%) of events occurred prior to the first incision, and 31.2% of events occurred while on bypass. While 68.0% of events were regarded as minor in severity (e.g., delays and missing equipment), a substantial proportion (32.0%) was considered major and included anastomotic problems, pump failure, and drug errors. Most problems (90.4%) were reported as being compensated for, although many (30.9%) were never discussed among the team. Major events were more likely to be discussed (p<0.0001) and less likely to have been previously encountered (p=0.0005). Perceptions of the severity and compensation of events varied across the team, as did temporal patterns of reporting (p<0.0001). CONCLUSIONS: A wide range of problematic precursor events occurs during the majority of cardiac surgery procedures. Attention to causes and ways of preventing these precursor events could have an impact on the rate of significant errors and improve the safety of cardiac surgery.

Minimally Invasive Mitral Valve Surgery III: Training and Robotic-Assisted Approaches.

Minimally invasive mitral valve operations are increasingly common in the United States, but robotic-assisted approaches have not been widely adopted for a variety of reasons. This expert opinion reviews the state of the art and defines best practices, training, and techniques for developing a successful robotics program.

Minimally Invasive Mitral Valve Surgery I: Patient Selection, Evaluation, and Planning.

Widespread adoption of minimally invasive mitral valve repair and replacement may be fostered by practice consensus and standardization. This expert opinion, first of a 3-part series, outlines current best practices in patient evaluation and selection for minimally invasive mitral valve procedures, and discusses preoperative planning for cannulation and myocardial protection.

Minimally Invasive Mitral Valve Surgery II: Surgical Technique and Postoperative Management.

Techniques for minimally invasive mitral valve repair and replacement continue to evolve. This expert opinion, the second of a 3-part series, outlines current best practices for nonrobotic, minimally invasive mitral valve procedures, and for postoperative care after minimally invasive mitral valve surgery.

Optimization of vessel orientation for robotic coronary artery bypass grafting.

The availability of telemanipulation robots has not yet resulted in the emergence of a reliable endoscopic coronary bypass procedure. A major challenge in performing a closed-chest coronary operation is creating a high-quality anastomosis in a reasonable period of time. In this experimental study, the impact of distal vessel orientation on the speed and accuracy of anastomosis was quantifed. We found that vessel orientation and the relative angle of the surgical plane influence anastomosis speed, the trauma to the vessel, the accuracy of stitch placement, and the eventual achievement of hemostasis. Our results suggest that the speed and accuracy of a robotically performed anastomosis of a vessel graft to a coronary artery can be improved by making small changes in vessel orientation. Vessels should be positioned between the horizontal and diagonal orientation and inclined between the horizontal and +45 degrees . Because the 6-o'clock stitch is particularly challenging, surgeons may benefit from an orientation that moves the heel or the toe of the anastomosis away from this critical position.

Inhaled Nitric Oxide Augments Left Ventricular Assist Device Capacity by Ameliorating Secondary Right Ventricular Failure.

Clinical right ventricular (RV) impairment can occur with left ventricular assist device (LVAD) use, thereby compromising the therapeutic effectiveness. The underlying mechanism of this RV failure may be related to induced abnormalities of septal wall motion, RV distension and ischemia, decreased LV filling, and aberrations of LVAD flow. Inhaled nitric oxide (NO), a potent pulmonary vasodilator, may reduce RV afterload, and thereby increase LV filling, LVAD flow, and cardiac output (CO). To investigate the mechanisms associated with LVAD-induced RV dysfunction and its treatment, we created a swine model of hypoxia-induced pulmonary hypertension and acute LVAD-induced RV failure and assessed the physiological effects of NO. Increased LVAD speed resulted in linear increases in LVAD flow until pulse pressure narrowed. Higher speeds induced flow instability, LV collapse, a precipitous fall of both LVAD flow and CO. Nitric oxide (20 ppm) treatment significantly increased the maximal achievable LVAD speed, LVAD flow, CO, and LV diameter. Nitric oxide resulted in decreased pulmonary vascular resistance and RV distension, increased RV ejection, promoted LV filling and improved LVAD performance. Inhaled NO may thus have broad utility for the management of biventricular disease managed by LVAD implantation through the effects of NO on LV and RV wall dynamics.

The use of cardiopulmonary bypass during resection of locally advanced thoracic malignancies: a 10-year two-center experience.

The use of cardiopulmonary bypass (CPB) for locally advanced thoracic malignancies is highly controversial. The purpose of this study was to document the techniques and results of CPB to facilitate the resection of complex thoracic malignancies and to identify common themes that provided for successful outcomes. This was a retrospective study that took place from January 1992 to September 2002. Fourteen consecutive patients (median age, 59 years; age range, 18 to 69 years; seven men and seven women) underwent CPB during the resection of locally advanced thoracic malignancies at two Boston hospitals. CPB was planned in 8 of 14 patients (57%) with centrally located tumors, while 6 of 14 patients (43%) required emergent institution of CPB due to injury of the superior vena cava (2 patients), inferior vena cava (2 patients), or pulmonary artery (2 patients). Complete microscopic resection was achieved in 12 of 14 patients (86%). The operative mortality rate was 1 of 14 patients (7%) due to pulmonary embolism (ie, the elective group). The median ICU and hospital lengths of stay were 5 and 9 days, respectively. The overall 1-year, 3-year, and 5-year survival rates were 57%, 36%, and 21%, respectively. The planned use of CPB to facilitate complete resection of thoracic malignancies should be considered only after careful patient selection. The availability of CPB also provides a safety net in the event of injury to vascular structures during tumor resection.

Endoscopic versus open saphenous vein harvest: a comparison of postoperative wound complications.

BACKGROUND: Wound complications associated with long incisions used to harvest the greater saphenous vein are well documented. Recent reports suggest that techniques of endoscopic vein harvest may result in decreased wound complications. A prospective, nonrandomized study was developed to compare outcomes of open versus endoscopic vein harvest procedures. METHODS: There were 106 patients in the open vein harvest group, and 154 patients in the endoscopic vein harvest group. Patient characteristics and demographics were similar in both groups. Wound complications identified were dehiscence, drainage for greater than 2 weeks postoperatively, cellulitis, hematoma, and seroma/lymphocele. RESULTS: Wound complications were significantly less in the endoscopic vein harvest group (9 of 133, 6.8%) versus the open vein harvest group (26 of 92, 28.3%), p less than 0.001. By multivariable analysis with logistic regression, the open vein harvest technique was the only risk factor for postoperative leg wound complication (relative risk 4.0). CONCLUSIONS: Endoscopic vein harvest offered improved patient outcomes in terms of wound healing compared with the open vein harvest technique.

Endoscopic multivessel coronary artery bypass grafting using automated device for proximal anastomosis.

BACKGROUND: The use of computer-enhanced telemanipulation robots in cardiothoracic surgery can reduce the need for open surgical access and enable closed-chest, endoscopic procedures, but these procedures hav e been limited to anterior target vessels. The feasibility of fully endoscopic multivessel, coronary artery bypass grafting (CABG) was examined. METHODS: Fully endoscopic, multivessel CABG solely through surgical ports was performed on 23 dogs weighing 75 to 85 pounds. A proximal anastomosis was made with the Symmetry bypass system aortic connector. The aorta was cross clamped, and cardioplegia solution was administered through the vein graft into the ascending aorta. RESULTS: Eighteen of 23 procedures yielded successful proximal anastomoses and 1 to 3 distal anastomoses. CONCLUSION: Endoscopic anastomosis to the ascending aorta is feasible with the Symmetry bypass connector. Antegrade cardioplegia and aortic root venting can then be easily accomplished. This approach simplifies closed chest cardioplegic arrest for mulitivessel CABG.

Continuous addition of adenosine with a micropump system improves warm whole blood cardioplegia.

BACKGROUND: Micropump additive systems allow for continuous modification of cardioplegia composition during heart surgery. Although the use of such systems in warm heart surgery is theoretically desirable, the role of the systems has been clinically limited by coronary vasoreactivity with higher potassium concentration and unreliable mechanical arrest at lower potassium concentration. Adenosine, a potent coronary vasodilator and arresting agent, has the potential to reduce the potassium concentration required for arrest and to improve distribution of cardioplegia. However, clinical use of adenosine has been limited by a short half-life in blood and difficulty in titrating the dose. This study tested the hypothesis that continuous addition of adenosine with an in-line linear micropump system would facilitate whole blood hyperkalemic perfusion for cardiac surgery. METHODS: Canine hearts (n = 9) were randomized to 20 minutes of arrest with whole blood cardioplegia or cardioplegia with adenosine at either low (0.5 M) or high (8 M) concentration. Potassium was supplemented at an arresting dose (24 mEq/L) for 5 minutes and then at a maintenance dose (6 mEq/L) for an additional 15 minutes. Coronary flow was held constant (4 mL/kg per minute), and aortic root pressure was measured. Myocardial performance was assessed by measurement of the end-diastolic pressure to stroke volume relationship at constant afterload. Myocardial tissue perfusion was evaluated with colored microspheres. RESULTS: During the initial period of high-concentration potassium arrest, coronary resistance rose progressively regardless of adenosine addition. Coronary resistance remained elevated during the period of low potassium perfusion, except when high-concentration adenosine was added. With addition of 8 M adenosine, coronary resistance returned to baseline, and left ventricular endocardial perfusion was augmented. Electromechanical quiescence improved with adenosine perfusion and was complete with high-dose adenosine addition. Function was preserved in all hearts. CONCLUSION: Use of a modern micropump system allowed for continuous addition of adenosine and potassium to whole blood cardioplegia. Adenosine minimized potassium-induced coronary vasoconstriction and improved endocardial perfusion and mechanical quiescence. These findings supported addition of adenosine to the perfusate during warm whole blood cardioplegia.

Aortic sclerosis is associated with mortality and major morbidity in patients undergoing coronary artery bypass surgery.

OBJECTIVE: In this study, we aim to investigate the association between aortic sclerosis and mortality and major morbidity in patients with established coronary artery disease undergoing coronary artery bypass grafting (CABG). DESIGN: Preoperative echocardiograms of consecutive patients undergoing isolated CABG between 2007 and 2009 (n=1150) were analysed, excluding patients without an echocardiogram in the 30 days prior to surgery (n=483). Using logistic regression, we evaluated the association between aortic sclerosis and inhospital mortality and major morbidity. Using Cox proportional hazards, the effect on long-term all-cause mortality was determined. SETTING: Massachusetts General Hospital, Boston. PATIENTS: Patients undergoing isolated CABG between 2007 and 2009. INTERVENTIONS: Analysis of echocardiograms. MAIN OUTCOME MEASURES: Inhospital mortality and major morbidity, and long-term all-cause mortality. RESULTS: 627 patients were suitable for enrolment; 207 (33%) had significant aortic sclerosis. These patients had higher rates of traditional cardiovascular risk factors. Significant aortic sclerosis was associated with an increased risk of inhospital mortality or major morbidity (OR 1.95; 95% CI 1.25 to 3.04). Following adjustment for baseline clinical and echocardiographic variables, the association remained significant (OR 1.90; 95% CI 1.15 to 3.11). The HR for adjusted all-cause mortality was 2.52 (mean follow-up 2.7 years). CONCLUSIONS: Aortic sclerosis is a common finding in patients undergoing CABG. In these patients, its presence is associated with a higher risk of inhospital mortality or major morbidity, and is associated with a higher risk of all-cause long-term mortality independent of other risk factors.

Educational program in crisis management for cardiac surgery teams including high realism simulation.

INTRODUCTION: Cardiac surgery demands effective teamwork for safe, high-quality care. The objective of this pilot study was to develop a comprehensive program to sharpen performance of experienced cardiac surgical teams in acute crisis management. METHODS: We developed and implemented an educational program for cardiac surgery based on high realism acute crisis simulation scenarios and interactive whole-unit workshop. The impact of these interventions was assessed with postintervention questionnaires, preintervention and 6-month postintervention surveys, and structured interviews. RESULTS: The realism of the acute crisis simulation scenarios gradually improved; most participants rated both the simulation and whole-unit workshop as very good or excellent. Repeat simulation training was recommended every 6 to 12 months by 82% of the participants. Participants of the interactive workshop identified 2 areas of highest priority: encouraging speaking up about critical information and interprofessional information sharing. They also stressed the importance of briefings, early communication of surgical plan, knowing members of the team, and continued simulation for practice. The pre/post survey response rates were 70% (55/79) and 66% (52/79), respectively. The concept of working as a team improved between surveys (P = .028), with a trend for improvement in gaining common understanding of the plan before a procedure (P = .075) and appropriate resolution of disagreements (P = .092). Interviewees reported that the training had a positive effect on their personal behaviors and patient care, including speaking up more readily and communicating more clearly. CONCLUSIONS: Comprehensive team training using simulation and a whole-unit interactive workshop can be successfully deployed for experienced cardiac surgery teams with demonstrable benefits in participant's perception of team performance.

Consumer comprehension of surgeon performance data for coronary bypass procedures.

BACKGROUND: Public and private organizations have called for increased transparency in reporting of outcomes data for hospitals and surgeons, including risk-adjusted coronary artery bypass graft surgery (CABG) mortality data. Limited information is available about how the public actually interprets these data. METHODS: Four different graphical and tabular displays of CABG outcomes for surgeons, three of which were modeled on current state public reports, were shown to 337 adults. Each display contained data for 3 to 5 hypothetical surgeons. For each format, respondents were asked to choose which surgeon they would be most and least likely to choose based on the data. Additionally, they were asked questions about public reporting. RESULTS: Accurate identification of best surgeon performance varied by display format, with a high of 66% on one display and a low of 16% on another. Only 6.4% identified the surgeon with the lowest risk mortality across all four displays. Respondents with at least some college education were significantly more likely to identify the surgeon with the lowest risk-adjusted mortality, compared with respondents having no college education (21% to 72% vs. 9% to 59%; p<0.01). In one display, the surgeon with the lowest risk-adjusted mortality was effectively penalized for taking on higher-risk patients; respondents tended to select the surgeon with the lowest-risk population but the highest risk-adjusted mortality. Overall, 82% of respondents said that access to these types of data would be "absolutely essential" or "very important" in choosing a surgeon. CONCLUSIONS: Comprehension by the public of risk-adjusted CABG outcomes is limited and varies by display format. Poorly constructed displays may have led to misinterpretation, with potential unintended adverse consequences such as risk aversion. Further work is needed to design displays that maximize accurate interpretation by the public and more clearly define the risk and benefit of public reporting of surgeon performance.