Radical nephrectomy with resection of vena cava thrombus using extracorporeal circulation and deep hypothermic circulatory arrest.

INTRODUCTION: Patients with renal cell carcinoma (RCC) with level 3 or 4 caval thrombus have a poor prognosis, with reported five-year survival rates of 30-40%. The aim of this study was to assess the perioperative morbidity and long-term oncological outcomes for radical nephrectomy with resection of vena cava thrombus using a combined surgical approach, including extracorporeal circulation and deep hypothermic circulatory arrest. METHODS: A retrospective review was performed of the institutional case log to identify all radical nephrectomies with caval thrombus performed from January 2006 to May 2020. RESULTS: Twenty-five patients were identified with level 2 thrombus in one (4%), level 3 thrombus in eight (32%), and level 4 in 16 (64%). The median followup was 20.6 months (range 0.2-133.3). The median age at surgery was 68.4 years (range 44.2-85.5). Twenty-one (84%) patients were symptomatic at presentation. Six (24%) patients had distant metastases at diagnosis. The median circulatory arrest time was 15 minutes (range 6-35). The 30-day grade ≥3 complication rate was 8%. The 30-day mortality rate was 8%. The one-year, two-year, three-year, and five-year recurrence-free survival (RFS) rates were 53%, 18%, 10%, and 10%, respectively. The median time to systemic treatment was 7.7 months (range 1.2-25.7). The one-year, two-year, three-year, and five-year overall survival (OS) rates were 70%, 43%, 36%, and 31%, respectively. CONCLUSIONS: Radical nephrectomy with resection of vena cava thrombus using extracorporeal circulation and deep hypothermic circulatory arrest is associated with some morbidity and mortality but remains a safe and effective strategy for advanced RCC patients who would otherwise be managed palliatively.

Planting the 'SEAD': early comprehensive exposure to surgery for medical students.

INTRODUCTION: The popularity of surgical specialties is declining amongst Canadian medical students. Limited early exposure of students to surgery and minor involvement of surgeons in preclerkship education are barriers to creating interest in the field. Although many informal observerships and interest groups exist, there are no structured programs in Canada that offer preclerkship medical students a comprehensive exposure to surgery. METHODS: Twenty first-year medical students participated in the Surgical Exploration and Discovery (SEAD) Program. SEAD is a pilot project at the University of Toronto providing a unique combination of (1) observerships, (2) informal discussions on surgical careers, and (3) hands-on simulation workshops across all 7 direct-entry specialties within the Department of Surgery. All participants underwent pretraining and posttraining evaluation of learning through a paper-based knowledge test and all completed a structured survey on the benefit of the course. RESULTS: Comparison of test scores revealed an overall significant improvement in learning (p<0.0001). The improvement in test scores was seen in the knowledge of all 3 components of the course (p<0.0001). Qualitative evaluation revealed a positive student experience, with 100% of students indicating that SEAD helped them identify new interests in surgical subspecialties. Finally, 100% of students stated that they would recommend the program to incoming medical students. CONCLUSION: The SEAD Program successfully improves preclerkship students' knowledge of surgical principles, understanding of a career in surgery, and basic surgical skills. Participation in the program also positively influenced their interest in pursuing a career in surgery. Programs such as SEAD may be offered to preclerkship medical students to improve their exposure to surgery at this level of training and to enhance perspectives toward surgical careers.

Cut-off values for transit time flowmetry: are the revision criteria appropriate?

BACKGROUND: Graft Imaging to Improve Patency (GRIIP), a single-center, randomized blinded clinical trial, reported that intraoperative graft assessment with graft revision according to a priori criteria of transit time flowmetry (TTF) and intraoperative fluorescent angiography did not improve graft patency at one year after coronary artery bypass grafting (CABG) when compared with standard intraoperative management. The objective of this study is to investigate whether other TTF values are more predictive of the saphenous vein graft (SVG) failure and/or clinical outcomes. METHODS: This is a case control retrospective study of 65 SVGs from 44 patients from GRIIP. Study outcomes were graft patency at 12 months and major adverse cardiac events (MACE; death, myocardial infarction, repeat revascularization). RESULTS: Twenty-two SVGs were occluded. In receiver operating characteristic curve analysis, TTF mean flow was significantly predictive of one-year SVG failure (area under the curve = 0.698, p < 0.01), and 31 mL/min was the best cut-off value (p = 0.017, sensitivity 63.6%, specificity 67.4%). The risk of graft occlusion was 14/28, 50% for grafts with mean flow <31 mL/min and 8/37, 21.6% for grafts with mean flow ≥ 31 mL/min. In logistic regression models, mean flow was a significant predictor of early SVG failure (Odds Ratio 0.95 [0.91-0.99] per mL/min, p = 0.014) whereas other TTF values, patient comorbidities, and/or medication at discharge were not. However, TTF values were not predictive of MACE. CONCLUSIONS: TTF can identify non-functional grafts during CABG, but is of questionable value to improve one-year graft patency.

Are stentless valves hemodynamically superior to stented valves? Long-term follow-up of a randomized trial comparing Carpentier-Edwards pericardial valve with the Toronto Stentless Porcine Valve.

OBJECTIVE: The benefit of stentless valves remains in question. In 1999, a randomized trial comparing stentless and stented valves was unable to demonstrate any hemodynamic or clinical benefits at 1 year after implantation. This study reviews long-term outcomes of patients randomized in the aforementioned trial. METHODS: Between 1996 and 1999, 99 patients undergoing aortic valve replacement were randomized to receive either a stented Carpentier-Edwards pericardial valve (CE) (Edwards Lifesciences, Irvine, Calif) or a Toronto Stentless Porcine Valve (SPV) (St Jude Medical, Minneapolis, Minn). Among these, 38 patients were available for late echocardiographic follow-up (CE, n = 17; SPV, n = 21). Echocardiographic analysis was undertaken both at rest and with dobutamine stress, and functional status (Duke Activity Status Index) was compared at a mean of 9.3 years postoperatively (range, 7.5-11.1 years). Clinical follow-up was 82% complete at a mean of 10.3 years postoperatively (range, 7.5-12.2 years). RESULTS: Preoperative characteristics were similar between groups. Effective orifice areas increased in both groups over time. Although there were no differences in effective orifice areas at 1 year, at 9 years, effective orifice areas were significantly greater in the SPV group (CE, 1.49 +/- 0.59 cm(2); SPV, 2.00 +/- 0.53 cm(2); P = .011). Similarly, mean and peak gradients decreased in both groups over time; however, at 9 years, gradients were lower in the SPV group (mean: CE, 10.8 +/- 3.8 mm Hg; SPV, 7.8 +/- 4.8 mm Hg; P = .011; peak: CE, 20.4 +/- 6.5 mm Hg; SPV, 14.6 +/- 7.1 mm Hg; P = .022). Such differences were magnified with dobutamine stress (mean: CE, 22.7 +/- 6.1 mm Hg; SPV, 15.3 +/- 8.4 mm Hg; P = .008; peak: CE, 48.1 +/- 11.8 mm Hg; SPV, 30.8 +/- 17.7 mm Hg; P = .001). Ventricular mass regression occurred in both groups; however, no differences were demonstrated between groups either on echocardiographic, magnetic resonance imaging, or biochemical (plasma B-type [brain] natriuretic peptide) assessment (P = .74). Similarly, Duke Activity Status Index scores of functional status improved in both groups over time; however, no differences were noted between groups (CE, 27.5 +/- 19.1; SPV, 19.9 +/- 12.0; P = .69). Freedom from reoperation at 12 years was 92% +/- 5% in patients with CEs and 75% +/- 5% in patients with SPVs (P = .65). Freedom from valve-related morbidity at 12 years was 82% +/- 7% in patients with CEs and 55% +/- 7% in patients with SPVs (P = .05). Finally, 12-year actuarial survival was 35% +/- 7% in patients with CEs and 52% +/- 7% in patients with SPVs (P = .37). CONCLUSION: Although offering improved hemodynamic outcomes, the SPV did not afford superior mass regression or improved clinical outcomes up to 12 years after implantation.

The Graft Imaging to Improve Patency (GRIIP) clinical trial results.

OBJECTIVE: This trial aimed to determine whether intraoperative graft assessment with criteria for graft revision would decrease the proportion of patients with 1 or more graft occlusions or stenoses or major adverse cardiac events 1 year after coronary artery bypass grafting. METHODS: A single-center, randomized, single-blinded, controlled clinical trial was designed. Patients were randomized to either of 2 groups: intraoperative graft patency assessment using indocyanine-green fluorescent angiography and transit-time flowmetry, with graft revision according to a priori criteria (imaging group), or standard intraoperative management (control group). Patients underwent follow-up angiography at 1 year. RESULTS: Between September 2005 and August 2008, 156 patients undergoing isolated coronary bypass grafting were enrolled (imaging, n = 78; control, n = 78). Demographic and angiographic characteristics were similar between groups. Operative, crossclamp, and cardiopulmonary bypass times were all nonsignificantly longer in the imaging arm. The number of grafts per patients was similar (imaging, 3.0 +/- 0.7; control, 3.0 +/- 0.7). The frequency of major adverse cardiac events (death, myocardial infarction, repeat revascularization) was not different between groups at 1 year postoperatively (imaging, 7.7%; control, 7.7%). One-year angiography was performed in 107 patients (imaging, 55 patients/160 grafts; control, 52 patients/152 grafts). The proportion of patients with 1 graft occlusion or more was comparable in the imaging (30.9%) and control (28.9%) groups (relative risk [95% confidence interval], 1.1 [0.6-1.9]; P = .82), as were other graft patency end points. The incidence of saphenous vein graft occlusion was high in both groups. CONCLUSIONS: Routine intraoperative graft assessment is safe but does not lead to a marked reduction in graft occlusion 1-year after bypass grafting. The incidence of saphenous vein graft failure remains high despite contemporary practice and routine intraoperative graft surveillance.

Troponin after cardiac surgery: a predictor or a phenomenon?

BACKGROUND: Increased cardiac troponin is observed after virtually every cardiac operation, indicating perioperative myocardial injury. The clinical significance of this elevation is controversial. This study aimed to correlate postoperative troponin levels with major adverse cardiac events (MACE). METHODS: The study included 1918 consecutive patients undergoing adult cardiac operations, including 1515 isolated coronary procedures, 229 valvular operations, and 174 combined coronary/valve procedures. Peak troponin T (normal value < 0.1 microg/L) was measured at less than 24 hours postoperatively. Excluded were 506 patients with a recent myocardial infarction (< 30-days of operation). The primary outcome was a composite of death, electrocardiogram-defined infarction, and low output syndrome (MACE). RESULTS: Mortality rates were 1.4%, 6.1%, and 7% in the coronary bypass, valve, and combined groups, respectively (p < 0.001). The rates of MACE were 17%, 35%, and 44% (p < 0.0001), and mean troponin T levels were 0.9 +/- 1.5, 1.2 +/- 2.9, and 1.3 +/- 1.2 microg/L (p < 0.001), in the coronary bypass, valve, and combined groups, respectively. All patients were divided into quintiles based on their peak postoperative troponin level (Q1, 0.0 to 0.39; Q2, 0.4 to 0.59; Q3, 0.6 to 0.79; Q4, 0.8 to 1.29; and Q5, > 1.3 microg/L). Adverse outcomes were similar and stable in the lower quintiles. A stepwise increase in adverse outcomes was observed in the higher quintiles. Receiver operating characteristic curve analysis revealed a troponin cutoff of 0.8 microg/L was the most discriminatory for MACE (area under the curve, 0.7). Multivariable analyses showed a troponin value of more than 0.8 microg/L was independently associated with MACE. CONCLUSIONS: Moderate elevations in troponin are common after cardiac operations; troponin is a well-described predictor of outcomes. Troponin levels exceeding 0.8 microg/L are associated with increased MACE in patients without a history of preoperative myocardial infarction within 30 days of operation.

A randomized comparison of intraoperative indocyanine green angiography and transit-time flow measurement to detect technical errors in coronary bypass grafts.

BACKGROUND: Early coronary bypass graft failures may be preventable if identified intraoperatively. The purpose of this investigation was to compare the diagnostic accuracy of two intraoperative graft assessment techniques, transit-time ultrasound flow measurement and indocyanine green fluorescent-dye graft angiography. METHODS: Patents undergoing isolated coronary artery bypass grafting with no contraindications for postoperative angiography were enrolled in the study. Patients were randomly assigned to be evaluated with either indocyanine green angiography (Novadaq Spy angiography system; Novadaq Technologies Inc, Concord, Ontario, Canada) and then transit-time ultrasonic flow measurement (Medtronic Medi-Stim Butterfly Flowmeter TTF measurement system; Medtronic Inc, Minneapolis, Minn) or transit-time flow then indocyanine green angiography. Patients underwent x-ray angiography on postoperative day 4. The primary end point of the trial was to determine the sensitivity and specificity of the two techniques versus reference standard x-ray angiography to detect graft occlusion or greater than 50% stenosis in the graft or perianastomotic area. RESULTS: Between February 2004 and March 2005, 106 patients were enrolled and x-ray angiography was performed in 46 patients. In total, 139 grafts were reviewed with all three techniques and 12 grafts (8.2%) were demonstrated to have greater than 50% stenosis or occlusion by the reference standard. The sensitivity and specificity of indocyanine green angiography to detect greater than 50% stenosis or occlusion was 83.3% and 100%, respectively. The sensitivity and specificity of transit-time ultrasonic flow measurement to detect greater than 50% stenosis or occlusion was 25% and 98.4%, respectively. The P value for the overall comparison of sensitivity and specificity between indocyanine green angiography and transit-time flow ultrasonography was .011. The difference between sensitivity for indocyanine green angiography and transit-time flow measurement was 58% with a 95% confidence interval of 30% to 86%, P = .023. CONCLUSION: Indocyanine green angiography provides better diagnostic accuracy for detecting clinically significant graft errors than does transit-time ultrasound flow measurement.

Improving the quality of coronary bypass surgery with intraoperative angiography: validation of a new technique.

OBJECTIVES: We report a comprehensive assessment and validation of a new intraoperative angiography technique. BACKGROUND: Technical problems at the site of the distal anastomosis compromise an underappreciated proportion of coronary bypass grafts. The absence of a systematic, validated technique to verify graft patency in the operating room represents a significant breach in quality assurance. METHODS: Fluorescent indocyanine green (ICG) dye is excited with dispersed laser light to create an angiographic depiction of the graft, native vessel, and anastomosis. One-hundred twenty patients underwent ICG angiography. Angiograms were reviewed for reliability and validity studies. RESULTS: A total of 348 coronary bypass grafts were studied. Each ICG angiogram took 2.2 +/- 1.1 min to perform. The ICG angiography found 4.2% of patients had significant graft problems requiring major revision. Quality of visualization was rated according to a seven-point Likert scale (1 = worst, 7 = best). Among conduits, saphenous veins were best visualized (mean score +/- standard deviation), 6.4 +/- 1.5 versus 5.5 +/- 1.9 for internal mammary arteries and 4.4 +/- 2.3 for radial arteries (p = 0.02). Location of distal anastomosis did not influence quality of visualization. There was high inter-rater reliability for graft revision (kappa = 1.0) and graft patency (kappa = 0.97) between surgeons. Sensitivity and specificity of the ICG angiograms for graft stenosis >50% was 100% among 22 grafts also studied with X-ray angiography. CONCLUSIONS: Information from ICG angiograms led to graft revisions for technical problems in 4.2% of patients that would have otherwise gone unrecognized. Intraoperative angiography is an emerging tool for improving the quality of coronary bypass surgery.

Determinants of incomplete left ventricular mass regression following aortic valve replacement for aortic stenosis.

OBJECTIVE: Incomplete regression of left ventricular hypertrophy (Abn-LVMI) following AVR for aortic stenosis (AS) may decrease long-term survival. In this prospective study, we identified the predictors of Abn-LVMI. METHODS: Between 1990 and 2000, 529 patients undergoing AVR for AS had clinical and hemodynamic data collected prospectively. Preoperative and annual postoperative transthoracic echos were employed to assess left ventricular mass index (LVMI) and hemodynamics. Abn-LVMI was defined as the 75th percentile of the lowest postoperative LVMI (>128 mg/m2, n = 133). All other patients were included in the normal regression group (N-LVMI). Univariate and multivariable logistic regression analyses were used to determine the predictors of Abn-LVMI. RESULTS: Preoperative hypertension, diabetes, coronary disease, valve size, mean postoperative gradients, effective orifice area, and patient-prosthesis mismatch (PPM, indexed EOA <0.60 cm2/m2) did not predict Abn-LVMI. By logistic regression the most important positive predictor of Abn-LVMI was the extent of preoperative LVMI, with an odds ratio of 37.5 (p < 0.0001). Survival (93.4 +/- 1.8% vs 94.8 +/- 2.3%, p = 0.90) and freedom from NYHA III-IV (75.0 +/- 3.7% vs 76.6 +/- 5.3%, p = 0.60) were similar for both groups at 7 years. CONCLUSIONS: Measures of valve hemodynamics were not important predictors of incomplete regression of hypertrophy. The extent of preoperative hypertrophy was the most important predictor, suggesting that earlier surgical intervention may reduce the extent of hypertrophy postoperatively. Furthermore, the significance of LV hypertrophy to long-term survival must be reassessed, in the absence of scientific evidence.

Long-term results of aortic valve replacement with the St. Jude Toronto stentless porcine valve.

BACKGROUND: Long-term survival and freedom from valve-related events of the St. Jude Toronto stentless porcine valve (SPV) are unknown. The aim of this study was to investigate late clinical outcomes after aortic valve replacement with the Toronto SPV. METHODS: Between 1992 and 2000, 200 patients (131 males, 69 females) underwent aortic valve replacement with the Toronto SPV. Mean patient age at implantation was 64.6 +/- 10.9 years (range 33 to 82 years). At the time of operation, 32%, 51%, and 17% of patients were in New York Heart Association class I/II, III, and IV, respectively. Aortic stenosis, aortic insufficiency, and combined lesions were present in 64%, 13.5%, and 22.5% of patients preoperatively. Concomitant coronary artery bypass grafting was performed in 34.5% of patients. RESULTS: Perioperative mortality occurred in 2.5% (5/200) of patients. There were 31 late deaths. Actuarial survival at 5 and 10 years was 89.2% and 68.0%, respectively. There was no significant difference in overall actuarial survival between isolated valve patients and valve plus coronary artery bypass grafting patients, 71% versus 62% respectively, p = 0.85. Actuarial freedom from valve reoperation at 5 and 10 years was 97.6% and 79.9%, respectively. Actuarial freedom from structural valve deterioration was 98.8% at 5 years and declined to 77.9% at 10 years. Freedom from structural valve deterioration was poorer in patients with preoperative aortic insufficiency or bicuspid disease. Actuarial freedom from embolic events and endocarditis at 10 years were 94.6% and 95.9%, respectively. CONCLUSIONS: Although early clinical results were excellent, a significant increase in hazard for structural valve deterioration occurred in late follow-up.

Why is off-pump coronary surgery uncommon in Canada? Results of a population-based survey of Canadian heart surgeons.

BACKGROUND: Off-pump coronary artery bypass (OPCAB) is proposed to improve clinical outcomes and decrease resource use. However, off-pump surgery is not widely used in Canada. The purpose of this study was to determine the current use of OPCAB in Canada and determine why surgeons have not adopted this technique. METHODS AND RESULTS: The study was a population-based survey of all adult Canadian cardiac surgeons in practice >1 year. Eligible division heads and surgeons were contacted by mail. Of 19 806 isolated coronary bypass surgeries performed by respondents in Canada last year, 3164 (16.0%) were performed off-pump. More than 50% of Canadian surgeons performed OPCAB in <5% of coronary cases, and only 17% of surgeons performed OPCAB in >25% of coronary cases. Only 4 responding centers performed OPCAB in >25% of cases. Respondents were divided into those who performed <5% of cases off-pump (nonadopters), 5% to 25% off-pump (intermediate users), or >25% off-pump (enthusiasts). Mean number of distal anastomoses in off-pump cases were 1.7+/-0.6, 1.6+/-0.6, and 3.3+/-0.5 for nonadopters, intermediate users, and enthusiasts, respectively (P=0.001). Eleven percent of nonadopters, 55% of intermediate users, and 81% of enthusiasts believed OPCAB improved clinical outcomes (P<0.0001). Only 23% of all respondents felt OPCAB use would increase in the next 5 years. CONCLUSIONS: Concerns regarding incomplete revascularization and lack of proven clinical benefit have limited OPCAB to being performed routinely by only a small number of surgeons in Canada.

Late outcomes in patients with uncorrected mild to moderate mitral regurgitation at the time of isolated coronary artery bypass grafting.

OBJECTIVES: Patients undergoing coronary artery bypass grafting often have untreated mild to moderate mitral regurgitation. The long-term outcome of these patients follows an uncertain course. The purpose of this study was to examine the late outcomes in patients with mild to moderate mitral regurgitation at the time of isolated coronary artery bypass grafting. METHODS: One hundred sixty-three patients with mild to moderate mitral regurgitation at the time of isolated coronary artery bypass grafting were identified from the prospectively collected cardiovascular database at Sunnybrook and Women's College Health Sciences Centre. These patients were matched 1:2 with patients who had isolated coronary artery bypass grafting without mitral regurgitation according to gender, age, left ventricular ejection fraction, New York Heart Association functional class, vascular disease, diabetes, extent of coronary disease, and year of surgery. There was 99% complete follow-up. Actuarial survival and event-free (death, myocardial infarction, stroke, cardiac hospitalization, and cardiac reintervention) survivals were compared by log-rank methods. Cox regression was used to assess the effects of the presence of mitral regurgitation on late survival and event-free survival. Preliminary postoperative follow-up echocardiography was available for 49 of the 163 patients with mitral regurgitation. RESULTS: There were 489 patients in the matched-cohort study, 163 with mitral regurgitation and 326 without. The average length of follow-up was 3.37 +/- 2.04 years. There was no difference in actuarial survival at 6 postoperative years (mitral regurgitation 81.0% vs no mitral regurgitation 84.7%, P =.9185). Event-free survival at 6 years was worse in the mitral regurgitation group (45.7% vs no mitral regurgitation 64.7%, P =.0258). Patients with mitral regurgitation had worse functional status (New York Heart Association class 3-4 20.0%, n = 30/150, vs no mitral regurgitation 8.1%, n = 25/307, P =.0046). After the matched variables were controlled for, the hazard ratios associated with the presence of mitral regurgitation by Cox regression were 0.958 (P =.7626) for survival and 1.198 (P =.0333) for event-free survival. The only other significant predictor of late survival was preoperative intra-aortic balloon pump insertion (hazard ratio 2.484, P =.0365). Of the patients who underwent follow-up echocardiography, 30.6% (n = 15/49) had progression of mitral regurgitation to moderate to severe degree at an average of 16.4 postoperative months. CONCLUSION: Overall late survival was not affected by the presence of mild to moderate degrees of mitral regurgitation in patients undergoing coronary artery bypass grafting. However, these patients had poorer event-free survival and worse late functional status. In a subset of patients with echocardiographic follow-up, the postoperative course of mitral regurgitation was variable, and nearly a third of these patients had worsening mitral regurgitation. Consideration should be given to repairing moderate mitral regurgitation in selected cases to improve long-term quality of life.

Radial artery use is safe in patients with moderate to severe left ventricular dysfunction.

BACKGROUND: Using radial artery grafts in patients with moderate to severe left ventricular dysfunction (LVD; ejection fraction < 35%) has been discouraged for the fear that postoperative vasopressor support may cause graft spasm and lead to ischemic complications. We, therefore, examined the safety of radial grafts in aortocoronary bypass (ACB) patients with LVD. METHODS: Data were collected from 5,455 patients who underwent isolated ACB between January 1995 and September 2001. One thousand eight hundred three patients received a radial artery graft (RadACB), and 3,652 patients did not (NoRadACB). Three hundred seven RadACB, and 819 NoRadACB operations were performed in LVD patients. A matched (age, sex, urgency of operation, diabetes, and renal insufficiency) cohort analysis was performed in LVD patients. Univariate and logistic regression analyses were performed in the entire population and the unmatched RadACB and NoRadACB patient subgroups to examine the effect of radial artery use on postoperative death or myocardial infarction rate. RESULTS: The matched cohort analysis revealed a similar rate of death or myocardial infarction (RadACB, 11 of 242 patients; NoRadACB, 16 of 242 patients; p = 0.32). Left ventricular dysfunction was associated with a higher rate of death or myocardial infarction in both unmatched groups (RadACB, odds ratio, 2.36; 95% confidence interval, 1.38 to 4.58; p = 0.004; NoRadACB, odds ratio, 1.62; 95% confidence interval, 1.18 to 2.24; p < 0.001) and in the entire population (odds ratio, 1.77; 95% confidence interval, 1.32 to 2.35; p = 0.003). An interaction term for patients with LVD and a radial artery graft, which was forced into the logistic regression model for the entire population, was not predictive of death or myocardial infarction (odds ratio, 1.52; 95% confidence interval, 0.75 to 3.10; p = 0.25). CONCLUSIONS: Left ventricular dysfunction carries similar risk for postoperative death or myocardial infarction in RadACB and NoRadACB patients. The presence of LVD in isolation is not a contraindication to the use of radial grafting.

The influence of cardiopulmonary bypass flow characteristics on the clinical outcome of 1820 coronary bypass patients.

OBJECTIVE: To determine whether pulsatile perfusion is clinically beneficial for adult cardiac operations. METHODS: Data concerning consecutive patients undergoing isolated coronary bypass surgery (n=1820) from January 1, 1997 to July 31, 1999 were reviewed. RESULTS: Nine hundred fifteen patients received pulsatile perfusion (PP) while perfusion in the remaining 905 patients was nonpulsatile (NP). Patients in the PP group were older (64.0 +/- 9.2 years versus 63.1 +/- 9.9 years) and experienced more of the following: urgent operations (42.4% versus 38.0%), preoperative intra-aortic balloon pump (4.8% versus 1.8%), preoperative cerebrovascular accidents (CVA; 3.1% versus 1.3%) and renal insufficiency (10.5% versus 7.0%). The PP group had higher incidence of early postoperative mortality (2.6% versus 1.5%), CVA (3.1% versus 1.3%), need for dialysis (3.2% versus 2.2%) and longer hospital stay (9.2 +/- 8.3 days versus 8.5 +/- 5.8 days). The incidence of postoperative myocardial infarction and renal dysfunction was similar in both groups (2.0% versus 2.2% and 3.3% versus 3.9% respectively; not significant). Because of the significant difference in preoperative parameters for the PP and NP groups, the following three statistical techniques were used to isolate the effect of perfusion characteristics on operative outcome: multiple regression, propensity score and risk stratification. Multivariate analysis did not find PP to be protective against mortality, morbidity and mortality, and CVA or for the development of postoperative renal dysfunction. When propensity score analysis was applied, the incidence of cardiac morbidity and mortality was strongly associated with the quintile (first quintile 6.7%, fifth quintile 27.0%, P<0.001). Multivariate analysis including quintiles did not find PP to be an independent predictor for mortality or for morbidity and mortality. Risk stratification was performed for age and for preoperative creatinine clearance levels. In all groups, PP did not seem to reduce the incidence of morbidity, morbidity and mortality, or the development of postoperative renal dysfunction. In patients with preoperative renal dysfunction, mean postoperative creatinine levels and the need for dialysis following surgery were similar in the PP and NP groups. CONCLUSION: Pulsatile flow does not appear to offer any clinical benefit over nonpulsatile flow for cardiac surgery patients.

The short-term and long-term effects of warm or tepid cardioplegia.

BACKGROUND: Clinical studies of myocardial protection rarely identify differences in hard clinical outcomes after surgery, either early or late, because most trials lack sufficient statistical power to deal with low-frequency events. METHODS: Prospectively collected data concerning all isolated coronary bypass operations from November 1989 to February 2000 were analyzed to determine the effects of cold blood cardioplegia and warm or tepid blood cardioplegia on early and late outcomes after surgery. Warm blood cardioplegia was used in 4532 patients, whereas cold blood cardioplegia was used in 1532. The allocation of patients to receive warm blood cardioplegia and cold blood cardioplegia was random in 749 cases and according to surgeon preference in the remainder. Most patients in the cold blood cardioplegia group had surgery earlier in the time course of the study, and most in the warm blood cardioplegia group underwent surgery later. RESULTS: Perioperative death, myocardial infarction, and death or myocardial infarction were all more common in the cold blood cardioplegia group than in the warm blood cardioplegia group (death 2.5% vs 1.6%, P =.027, adjusted odds ratio 1.45, 95% confidence interval 0.95-2.22, P =.09; myocardial infarction 5.4% vs 2.4%, P <.0001, adjusted odds ratio 1.86, 95% confidence interval 1.36-2.53, P <.0001; death or myocardial infarction 7.3% vs. 3.8%, P <.0001, adjusted odds ratio 1.70, 95% confidence interval 1.30-2.21, P <.0001). Actuarial survival at 60 months was 91.1% +/- 1.4% in the warm blood cardioplegia group and 89.9% +/- 1.3% in the cold blood cardioplegia group (P =.09), whereas freedom from death or myocardial infarction was 84.7% +/- 1.8% and 83.2% +/- 1.6%, respectively (P =.16). In multivariate models, cold blood cardioplegia was associated with poorer survival (risk ratio 1.30, 95% confidence interval 0.96-1.75, P =.09) and freedom from any death or late myocardial infarction (risk ratio 1.93, 95% confidence interval 1.56-2.39, P =.0001). CONCLUSIONS: In 6064 patients undergoing isolated coronary artery bypass grafting, warm or tepid blood cardioplegia may be associated with better early and late event-free survivals than is cold cardioplegia.

Patient prosthesis mismatch is rare after aortic valve replacement: valve size may be irrelevant.

BACKGROUND: Although small valve size and patient-prosthesis mismatch are both considered to decrease long-term survival, little direct evidence exists to support this hypothesis. METHODS: To assess the prevalence of patient-prosthesis mismatch and the influence of small valve size on survival, we prospectively studied 1,129 consecutive patients undergoing aortic valve replacement between 1990 and 2000. Mean and peak gradients and indexed effective orifice area were measured by transthoracic echocardiography postoperatively (3 months to 10 years). Abnormal postoperative gradients were defined as those patients with mean or peak gradient above the 90th percentile (mean gradient > or = 21 or peak gradient > or = 38 mm Hg). Patient-prosthesis mismatch was defined as those patients with indexed effective orifice area below the 10th percentile (< 0.60 cm2/m2). RESULTS: A multivariable analysis identified internal diameter of the implanted valve as the only independent predictor of abnormal gradients postoperatively. However, there was no significant difference in actuarial survival between normal and abnormal gradient groups (7 years: 91.2% +/- 1.5% versus 95.0% +/- 2.2%; p = 0.48). Freedom from New York Heart Association class III or IV (7 years: 74.5% +/- 3.1% versus 74.6% +/- 6.2%; p = 0.66) and left ventricular mass index were not different between normal and abnormal gradient groups. Patients with and without patient-prosthesis mismatch were similar with respect to postoperative left ventricular mass index, 7-year survival (95.1% +/- 1.3% versus 94.7% +/- 3.0%; p = 0.54), and 7-year freedom from New York Heart Association class III or IV (79.3% +/- 6.6% versus 74.5% +/- 2.5%; p = 0.40). In patients with patient-prosthesis mismatch and abnormal gradients, the majority had prosthesis dysfunction owing to degeneration. CONCLUSIONS: Severe patient-prosthesis mismatch is rare after aortic valve replacement. Patient-prosthesis mismatch, abnormal gradient, and the size of valve implanted do not influence left ventricular mass index or intermediate-term survival.

The insulin cardioplegia trial: myocardial protection for urgent coronary artery bypass grafting.

BACKGROUND: Small, nonrandomized clinical trials have demonstrated a beneficial effect of solutions containing insulin and glucose on the recovery of myocardial metabolism and ventricular function after cardioplegic arrest and reperfusion. However, no large, blinded, randomized study has yet determined the effects of insulin-enhanced cardioplegia on clinical outcomes after coronary artery bypass grafting. METHODS: The Insulin Cardioplegia Trial was designed to evaluate the clinical impact of insulin-enhanced cardioplegia on patients at high risk undergoing isolated coronary artery bypass grafting for unstable angina. A total of 1127 patients were randomly assigned at operation to receive cardioplegic solution supplemented with 10 IU/L insulin (n = 557) or placebo (n = 570). All personnel with direct patient contact were blinded to randomization group. RESULTS: Overall operative mortality was 2.2%, with no significant differences between groups. The prevalences of postoperative low output syndrome (insulin 10.4%, placebo 9.7%, P =.7) and enzymatic myocardial infarction (insulin 21.0%, placebo 18.8%, P =.3) were not different between groups. The primary composite outcome of low output syndrome and/or enzymatic myocardial infarction revealed no difference between groups (insulin 30.0%, placebo 26.3%, P =.2). CONCLUSIONS: Despite encouraging results from smaller, nonrandomized studies, the Insulin Cardioplegia Trial failed to demonstrate a clinical benefit of insulin-enhanced cardioplegic solution for patients undergoing high-risk isolated coronary artery bypass grafting.

Are stentless valves hemodynamically superior to stented valves? A prospective randomized trial.

BACKGROUND: Although stentless aortic bioprostheses are believed to offer improved outcomes, hemodynamic benefits remain unsubstantiated. METHODS: Fifty-three patients were randomized to receive the stented C-E pericardial valve (CE) and 46 patients the Toronto Stentless Porcine valve (SPV). Annuli were sized for the optimal insertion of both valve types, such that surgeons were required to commit to specific valve sizes before randomization. Echocardiographic measurements and functional status (Duke Activity Status Index) were assessed at 3 and 12 months postoperatively. RESULTS: Although cardiopulmonary bypass times (CE: 118.6+/-36.3 minutes; SPV: 148.5+/-30.9 minutes; p = 0.0001) and aortic cross-clamp times (CE: 95.4+/-28.6 minutes; SPV: 123.6+/-24.1 minutes; p = 0.0001) were significantly prolonged in the SPV group, perioperative morbidity and mortality was similar between groups. Neither valve offered a superior internal diameter for any given annular diameter (mean decrease in left ventricular outflow tract diameter after valvular implantation: SPV: 3.4+/-1.11 mm versus CE: 3.7+/-1.33 mm; p = 0.25). Although labeled mean valve size was significantly larger in the SPV group, the actual mean valve size based on internal valvular diameter was no different between groups (CE: 21.9+/-2.0 mm; SPV: 22.3+/-2.0 mm; p = 0.286). Although effective orifice areas increased, and mean and peak transvalvular gradients decreased in both groups over time, no differences were demonstrated between groups at 12 months. Similarly, although significant regression of left ventricular mass was accomplished in both groups over time, no differences were demonstrated between groups. Finally, Duke Activity Status Index scores of functional status improved in both groups over time; however, no differences were noted between groups at 12 months postoperatively. CONCLUSIONS: Although offering excellent outcomes, stentless valves did not demonstrate superior hemodynamic indices in comparison to stented valves up to 12 months after implantation.