Sudden Tamponade From Vein Graft Side Branch Avulsion on Removal of Temporary Pacemaker Wires

Temporary epicardial pacing wires are universally used in cardiac surgery and are associated with very low morbidity and mortality. Although rare, serious complications can occur with pacing wires. We present a case of avulsion of a saphenous vein graft side branch caused by removal of pacing wires and leading to pericardial tamponade. Our case favors the use of silk ties rather than hemoclips for occlusion of saphenous vein side branches and illustrates the importance of the location of pacing wires relative to the grafts at the time of coronary artery bypass surgery.

Retrospective cohort analysis of 926 tricuspid valve surgeries: clinical and hemodynamic outcomes with propensity score analysis

BACKGROUND

The objectives were to describe morbidity and mortality after tricuspid valve (TV) surgery, to compare outcomes after repair versus replacement, and to assess risk factors for mortality and tricuspid regurgitation (TR) recurrence.

METHODS

A retrospective cohort study including 926 consecutive cases of TV surgery (792 repairs and 134 replacements) performed at the Montreal Heart Institute was conducted. Median follow-up was 4.3 years (4,657 patient-years). Median age was 62 years (interquartile range 53-69 years), and 72% of patients were women.

RESULTS

Operative mortality was 14% (128 patients: 1977-1998 20%, 1999-2008 7%, P < .001). Independent risk factors for operative mortality in the 1999 to 2008 period were hypertension (odds ratio [OR] 6.03, P = .02), daily furosemide dose (by 10 mg) (OR 1.06, P = .05), weight (by 10 kg) (OR 0.36, P < .01), and cardiopulmonary bypass time (by 10 minutes) (OR 1.29, P < .001). Ten-year survival was 49% ± 2% and 38 ± 5% in the repair and replacement groups, respectively (P = .012). At discharge, severity of TR was ≥3/4 in 13% and 2% of patients in the repair and replacement groups, respectively (P = .01). Propensity score analysis showed that tricuspid repair was associated with higher rates of TR ≥3/4 at follow-up compared with replacement (hazard ratio 2.15, P = .02). Forty-eight reoperations (7% of patients at risk) were performed during follow-up (repair group, 6%; replacement group, 15%; P = .01). At last follow-up, New York Heart Association functional class was improved compared with baseline in both groups (P < .001).

CONCLUSION

Tricuspid valve surgery is associated with substantial early and late mortalities but with significant functional improvement. Replacement is more effective in early and late corrections of regurgitation, but it does not translate into better survival outcomes.

Statin treatment equalizes long-term survival between patients with single and bilateral internal thoracic artery grafts

BACKGROUND

The use of 2 internal thoracic artery (ITA) grafts increases survival 10 years after coronary artery bypass grafting (CABG) compared with single ITA grafting. Statin treatment was also shown to decrease development and progression of saphenous vein graft atherosclerosis. This study examined the effect of statin treatment on long-term survival after CABG.

METHODS

Operative, survival, and pharmacologic data of 6655 patients who underwent CABG with ITAs between 1995 and 2007 in our institution were obtained.

RESULTS

Patients with bilateral ITA grafts had an average 10-year-survival rate of 83% +/- 2% compared with 67% +/-1% in patients with single ITA grafts (p = 0.0001). Statin treatment caused a significant decrease in the long-term risk of death among patients who underwent single ITA grafting (hazard ratio [HR], 0.735, p = 0.0001). However, statin treatment had no effect on the risk of long-term death among patients who underwent bilateral ITA grafting (HR, 1.053; p = 0.7806).

CONCLUSIONS

Statin treatment initiated early after grafting improved long-term survival in patients with a single ITA graft but not in those with bilateral ITA grafts. Survival of statin-treated patients with single ITA grafts was similar to bilateral ITA patients.

Dynamic right ventricular outflow tract obstruction in cardiac surgery

BACKGROUND

Right ventricular outflow tract obstruction can be a cause of hemodynamic instability but it has not been described in non-congenital cardiac surgery.

METHODS

The prevalence of right ventricular outflow tract obstruction was retrospectively studied in 670 consecutive patients undergoing cardiac surgery. Significant right ventricular outflow tract obstruction was diagnosed if the right ventricular systolic to pulmonary artery peak gradient was more than 25 mm Hg. The diagnosis was based on measurement of the right ventricular and pulmonary artery systolic pressure through the paceport and distal opening of the pulmonary artery catheter. To further validate the prevalence and the importance of right ventricular outflow tract obstruction, 130 patients were prospectively studied over a 12-month period.

RESULTS

In the retrospective cohort, 6 patients (1%) undergoing various types of cardiac surgical procedures were found to have significant dynamic right ventricular outflow tract obstruction with a mean gradient of 31 +/- 4 mm Hg (26 to 35 mm Hg). In the prospective study significant dynamic right ventricular outflow tract obstruction was identified in 5 patients (4%) (average peak: 37 +/- 15 mm Hg; range: 27 to 60 mm Hg). The typical transesophageal echocardiography finding was end-systolic obliteration of the right ventricular outflow tract. In patients with significant dynamic right ventricular outflow tract obstruction, hemodynamic instability was present in 10/11 patients (91%).

CONCLUSIONS

Right ventricular outflow tract obstruction is easily diagnosed using the paceport of the pulmonary artery catheter and should be considered as a potential cause of hemodynamic instability especially when transesophageal echocardiography reveals systolic right ventricular cavity obliteration.

Fifteen years of clinical and echocardiographic follow up with the carbomedics heart valve

BACKGROUND AND AIM OF THE STUDY

Mechanical prostheses are used in young patients, the CarboMedics valve having been the mechanical valve of choice of the present authors during the past 15 years. The study aim was to analyze long-term clinical and echocardiographic results obtained with CarboMedics mechanical valves.

METHODS

A total of 2,953 patients underwent valve replacement with the CarboMedics valve between 1988 and 2004 at the Montreal Heart Institute. Patients were prospectively followed at the outpatient valve clinic. Subsequently, 1,004 patients underwent echocardiographic examinations during follow up.

RESULTS

In total, 1,597 patients (mean age 57 +/- 12 years) underwent isolated aortic valve replacement (AVR), 1,043 patients (mean age 59 +/- 10 years) underwent isolated mitral valve replacement (MVR), and 313 patients (mean age 58 +/- 11 years) underwent AVR+MVR. The mean five-, 10- and 15-year actuarial survival rates were 83 +/- 1%, 70 +/- 2% and 62 +/- 3% in AVR patients, 76 +/- 1%, 59 +/- 2% and 40 +/- 14% in MVR patients, and 68 +/- 3%, 51 +/- 4% and 33 +/- 9% in AVR+MVR patients. The mean 15-year freedom from cerebral embolism, hemorrhage and reoperation was 95 +/- 1%, 97 +/- 1% and 95 +/- 1% in AVR patients, 92 +/- 1%, 97 +/- 1% and 93 +/- 1% in MVR patients, and 94 +/- 2%, 93 +/- 2% and 91 +/- 4% in AVR+MVR patients. AVR patients had a mean aortic gradient of 29 +/- 14, 20 +/- 8, 18 +/- 7, 16 +/- 7, 12 +/- 5 and 11 +/- 5 mmHg with 19, 21, 23, 25, 27 and 29 mm prostheses, respectively (p = 0.001). MVR patients had a mean mitral gradient of 5.3 +/- 3, 4.9 +/- 2.2, 4.6 +/- 2, 4.4 +/- 2.9 and 4.9 +/- 1.8 mmHg with 25, 27, 29, 31 and 33 mm prostheses, respectively (p = 0.63).

CONCLUSION

Patient survival and valve-related complications were satisfactory at 15 years after valve replacement with the CarboMedics valve. Mean aortic gradients were high with the 19-mm aortic prostheses, but all other valve sizes showed good hemodynamic performance, as measured using transthoracic echocardiography.

Influence of diabetes and bilateral internal thoracic artery grafts on long-term outcome for multivessel coronary artery bypass grafting☆

OBJECTIVE

Diabetes mellitus is a major independent risk factor for morbidity and mortality after coronary artery bypass grafting (CABG). The aim of this study was to assess the effect of bilateral (B) internal thoracic artery grafting (ITA) in diabetic patients with multivessel CABG.

METHODS

Between 1985 and 1995, 4382 patients underwent primary isolated multivessel CABG with ITA grafting and concomitant saphenous vein grafting (SVG). Outcome of diabetic and nondiabetic patients undergoing single (S) ITA+SVG (n=419 and 2079) and BITA+SVG (n=214 and 1594) grafting was obtained at a mean follow-up of 11+/-3 years.

RESULTS

Diabetic patients were older, included more women, and had more obesity, hypertension and peripheral vascular disease than nondiabetic patients. Deep sternal wound infection rate was 1.9% for diabetic patients vs 1.2% for nondiabetic patients (P=0.2) and 30-day mortality was 1.7 vs 1.8% (P=0.9). Cox regression analysis with interaction term and propensity scoring showed that BITA grafting decreased the risk of death (Hazard Ratio=0.72 [0.57-0.91, 95%CI]) and coronary reoperation (HR=0.38 [0.19-0.77]) in both diabetic and nondiabetic patients, with no significant interaction noted. BITA grafting decreased the risk of myocardial infarction at long-term follow-up in nondiabetic patients (HR=0.72 [0.60-0.86]) but not in diabetic patients. Ten-year freedom rate from myocardial infarction in diabetic patients was 80 and 76% for SITA and BITA grafting patients, respectively. However, survival following myocardial infarction was better for patients who underwent BITA grafting, in both diabetic and nondiabetic subgroups.

CONCLUSIONS

BITA+SVG grafting in diabetic patients improves survival and decrease coronary reoperation compared with SITA+SVG at long-term follow-up. Survival following myocardial infarction is improved with BITA grafting.

Increased early postoperative morbidity with off-pump coronary artery bypass grafting surgery in patients with diabetes

BACKGROUND

Patients with diabetes constitute a high-risk population for myocardial revascularization due to extensive coronary disease.

OBJECTIVE

To compare the early postoperative outcomes of patients with diabetes undergoing off-pump or on-pump coronary artery bypass surgery.

METHODS AND RESULTS

Over a four-year period (1995 to 1998), 885 diabetics were operated for primary isolated coronary bypass; 156 patients had off-pump and 729 had on-pump coronary artery bypass surgery. Patients in the off-pump group were significantly older, had a higher incidence of hypertension and renal failure, and received fewer distal anastomoses (2.7 versus 2.9, P=0.004). Postoperative myocardial infarction, reintubation and postoperative use of intra-aortic balloon pump occurred significantly more frequently in the off-pump group (10.3% versus 5.5%, P=0.04; 8.3% versus 3.6%, P=0.03; 7.7% versus 1.5%, P=0.0001, respectively). Multivariate analysis revealed that type of surgery was an independent predictor of these complications, which occurred 1.9, 2.7 and 7.9 times more often, respectively, in the off-pump group. The 30-day mortality rate was not significantly different between the groups.

CONCLUSIONS

Off-pump coronary artery bypass surgery is associated with an increased early postoperative morbidity in patients with diabetes and, thus, should be used with caution.

Twenty-five years' clinical experience with repair of tricuspid insufficiency

BACKGROUND AND AIM OF THE STUDY

Tricuspid regurgitation secondary to pulmonary hypertension due to left-sided heart valve lesions is common. Here, the results are reported of 25 years' experience with three surgical techniques; the De Vega semicircular annuloplasty, the Bex flexible linear reducer, and the Carpentier-Edwards prosthetic ring annuloplasty.

METHODS

Between 1976 and 2002, 463 patients underwent 478 tricuspid annuloplasty procedures to correct valve regurgitation during associated left-sided valve surgery. Patients were followed prospectively at the Montreal Heart Institute Valve Clinic.

RESULTS

A total of 107 patients (23%) underwent the De Vega semicircular annuloplasty, 267 (58%) the Bex flexible linear reducer, and 89 (19%) the Carpentier-Edwards prosthetic ring annuloplasty. Excluding 30-day mortality, the mean 5-, 10- and 15-year patient survival was 82+/-4%, 58+/-6% and 30+/-6% respectively after the De Vega semicircular annuloplasty, 76+/-3%, 54+/-4% and 36+/-6% respectively after the Bex flexible linear reducer, and the mean five-year patient survival was 88+/-4% after the Carpentier-Edwards prosthetic ring annuloplasty (p = 0.65, for comparison of the three survival curves). The mean freedom rate from tricuspid repair failure (clinical right heart failure, redo annuloplasty, tricuspid valve replacement at follow up) was 95+/-3%, 93+/-3% and 72+/-8% at 5, 10 and 15 years respectively after the De Vega semicircular annuloplasty, and 97+/-1%, 87+/-4% and 66+/-9% after the Bex flexible linear reducer. The mean freedom rate from repair failure was 94+/-3% at five years after the Carpentier-Edwards prosthetic ring annuloplasty (p = 0.18 for comparison of the three freedom from failure curves).

CONCLUSION

All three techniques of tricuspid valve repair resulted in a low rate of failure, and in good patient survival at long-term follow up.

Prosthetic valve thrombosis: twenty-year experience at the montreal heart institute

BACKGROUND

Prosthetic valve thrombosis is a life-threatening complication. We reviewed the incidence, risk factors, and treatment strategies of this rare complication.

METHODS

From February 1981 through January 2001, 5430 valve operations were performed in 4924 patients at the Montreal Heart Institute. Of this cohort, 39 patients presented with prosthetic valve thrombosis and had complete follow-up data obtained from our prospective valve clinic database.

RESULTS

In this series 82% of patients were women, and the mean age was 58 +/- 11 years. The underlying pathology involved the mitral valve in 75% of cases. Most prosthetic valve thromboses occurred with mechanical prostheses (95%). The time interval from first valve replacement to prosthetic valve thrombosis was 39 +/- 42 months. The most frequent clinical presentation was severe congestive heart failure (44%). On prosthetic valve thrombosis presentation, the international normalized ratio was less than 2.5 in 54%, with inadequate anticoagulation management in 26% and poor compliance in 26%. Eighty-two percent of patients underwent a surgical procedure, consisting of thrombectomy in 47%, mitral valve replacement in 47%, and aortic valve replacement in 6% of patients. The 30-day operative mortality and total in-hospital mortality after prosthetic valve thrombosis were 25% and 41%, respectively. The 10-year actuarial survival after prosthetic valve thrombosis was 46% +/- 10%.

CONCLUSION

Inadequate level of anticoagulation is the most important factor involved in the pathogenesis of prosthetic valve thrombosis. The overall mortality rate despite surgical treatment remains high. This study underscores the importance of meticulous surveillance of anticoagulation therapy in patients with prosthetic valves.

Single versus bilateral internal thoracic artery grafts with concomitant saphenous vein grafts for multivessel coronary artery bypass grafting: effects on mortality and event-free survival

BACKGROUND

The issue of superiority of single internal thoracic artery grafting versus bilateral internal thoracic artery grafting remains unresolved. The aim of this study was to compare the long-term outcome of single and bilateral internal thoracic artery grafting with concomitant saphenous vein grafting for multivessel coronary artery bypass grafting.

METHODS

Between March 1985 and April 1995, 6650 patients underwent primary isolated coronary artery bypass grafting with internal thoracic artery grafts, including 4382 patients with multivessel bypass grafting requiring at least 3 grafts. Outcomes of patients undergoing single internal thoracic artery plus saphenous vein grafting (n = 2547) and bilateral internal thoracic artery plus saphenous vein grafting (n = 1835) were obtained at a mean follow-up of 11 +/- 3 years.

RESULTS

Patients with bilateral internal thoracic artery grafting were younger, were mostly male, and had less diabetes, hypertension, unstable angina, and recent myocardial infarction than patients undergoing single internal thoracic artery grafting. Thirty-day mortality was 2.3% for the group undergoing single internal thoracic artery grafting versus 1.2% for those undergoing bilateral internal thoracic artery grafting (P =.007). Survival probability at 10 years was 88% for the single-graft group compared with 93% for the bilateral-graft group (P <.001). Multivariate analysis with propensity scoring showed that bilateral internal thoracic artery grafting decreased the risk of death (hazard ratio, 0.74; 95% confidence interval, 0.60-0.90), myocardial infarction (hazard ratio, 0.79; 95% confidence interval, 0.67-0.93), and coronary reoperation (hazard ratio, 0.41; 95% confidence interval, 0.21-0.80) throughout the follow-up period. Other significant predictors of death were diabetes, prior myocardial infarction, need for intra-aortic balloon pump, chronic heart failure, and peripheral vascular disease.

CONCLUSION

Patients undergoing bilateral internal thoracic plus saphenous vein grafting appear to have a significantly better long-term clinical outcome than patients undergoing single internal thoracic artery plus saphenous vein grafting for multivessel coronary artery bypass grafting.

Vacuum-assisted venous drainage does not increase the neurological risk

BACKGROUND

Vacuum-assisted venous drainage (VAVD) with negative pressure applied to integral sealed-hardshell venous reservoir facilitates valvular surgery through minimally invasive approaches. Despite concerns regarding air entrainment from the right atrium, cerebral microemboli of air and neurological complications, VAVD was used in patients who underwent valvular surgery throughout the last two years in our institution.

METHODS

We compared the rate of neurological complications in patients who underwent surgery with and without VAVD from June 1997 to July 2001. VAVD was added to solid venous reservoirs with membrane oxygenators and arterial filters. Clinical results were prospectively entered in our valve database and were used for the analysis.

RESULTS

Eight hundred twenty-two consecutive patients averaging 65 +/- 11 years of age underwent aortic, mitral and tricuspid valve replacements including 40 redos (40/822, 5%) and 265 associated CABG (265/822, 32%) with VAVD in 1999 to 2001 compared to 723 patients averaging 63 +/- 11 years of age (p = 0.01) who underwent the same procedures with 79 redos (79/723, 11%) and 177 CABG (177/723, 24%) without VAVD in 1997 to 1999. CPB time averaged 117 +/- 50 minutes in VAVD patients compared to 108 +/- 43 minutes in those without VAVD (p = 0.001). Thirty-day mortality averaged 5% (39/822) in patients with VAVD and 4% (30/723) in those without VAVD (p = 0.6). Seven patients of the VAVD group (7/822, 1%) and 11 patients without VAVD (11/723, 1.5%, p = 0.2) suffered from temporary or permanent neurological deficit.

CONCLUSION

VAVD is a useful adjunct to modern cardiopulmonary bypass systems. When used with appropriate care, VAVD does not appear to significantly increase air microemboli and is not associated with an increased neurological risk following valvular surgery.

Tricuspid valve replacement: an analysis of 25 years of experience at a single center

BACKGROUND

Tricuspid valve replacement is seldom used in clinical practice, but the choice between mechanical and biologic prostheses remains controversial.

METHODS

Between 1977 and 2002, 97 patients underwent tricuspid valve replacement and were followed at the Montreal Heart Institute Valve Clinic. Patients underwent replacement with bioprostheses (n = 82) and mechanical valves (n = 15).

RESULTS

Patients with bioprosthetic tricuspid replacements averaged 53 +/- 13 years of age compared with 48 +/- 11 years in those with tricuspid mechanical valve replacements (p = 0.2). Isolated tricuspid valve replacement was performed in 11 patients (73%) in the mechanical valve group compared with 31 patients (38%. p = 0.01) in the bioprosthetic replacement group. In patients undergoing bioprosthetic tricuspid replacement, 51 (62%) underwent multiple associated valve replacements. The 5-year survival after tricuspid replacement averaged 60% +/- 13% in the mechanical valve group and 56% +/- 6% in the biologic replacement group (p = 0.8). The 5-year freedom rate from tricuspid valve reoperation averaged 91% +/- 9% in patients with mechanical valves and 97% +/- 3% in those with biologic valves (p = 0.2). CONCLUSIONS; Patient survival after tricuspid valve replacement is suboptimal but related to the clinical condition at operation. The use of biologic prostheses for tricuspid valve replacement remains a good option in young patients because of limited life expectancy unrelated to the type of tricuspid prostheses at long-term follow-up.

Reduced mortality and strokes with off-pump coronary artery bypass grafting surgery in octogenarians

BACKGROUND

Off-pump coronary artery bypass surgery (OPCAB) has been revived and has gained popularity, although the exact subsets of patients who might benefit most from this technique are unknown. The aim of this retrospective study was to compare the results of coronary artery bypass grafting surgery (CABG) in octogenarians using cardiopulmonary bypass (CPB) or OPCAB techniques.

METHODS AND RESULTS

Over a 5-year period (1995-1999), 125 patients older than 80 years of age were operated for isolated myocardial revascularization (63 using CPB and 62 with OPCAB). There was no statistically significant difference in preoperative comorbidities between groups or in mean left ventricular ejection fraction (54.5+/-15.3% in the CPB group and 50.9+/-13.5% in the OPCAB group, respectively). The mean number of distal anastomosis per patient was 2.9 in CPB group and 2.6 in OPCAB group (P=ns). The majority of patients in both groups had unstable angina and were operated on an urgent basis. The operative mortality was 15.9% in the CPB group and 4.8% in the OPCAB group (P=0.04). There were 4 postoperative strokes (6.3%) in the CPB group and none (0%) in the OPCAB group (P=0.04). The percentage of patients transfused was 92.1% in the CPB group and 72.6% in the OPCAB group (P<0.01). Postoperative myocardial infarction occurred in 11.3% in the CPB group and 14.5% in the OPCAB group (P=NS). For all the parameters entered in the multivariate analysis with logistic regression model, the type of surgery (CPB or OPCAB) was an independent predictor of operative mortality and stroke (P=0.0375). The odds ratio (OR) indicates that operative mortality and stroke occur 4 times (OR=4.171) more often in CPB patients than in OPCAB patients. Follow-up showed no significant difference between the 2 groups in terms of cardiac events and mortality.

CONCLUSIONS

This retrospective study suggests a benefit of OPCAB in terms of operative mortality and stroke for octogenarian patients when compared with CPB in our institution.

Early reoperation for iatrogenic left main stenosis after aortic valve replacement: a perilous situation

BACKGROUND

Iatrogenic left main coronary artery (LMCA) stenosis secondary to direct ostial cannulation during aortic valve replacement still occurs and is a morbid situation due to the difficulties of early reoperation and in providing adequate myocardial protection.

METHODS

A retrospective analysis was performed and identified seven patients with an iatrogenic LMCA stenosis, after 2158 aortic valve replacements (AVR) (0.3%) in our institution since 1987.

RESULTS

All patients with LMCA stenosis after AVR had undergone direct ostial cannulation with self-inflating balloon cannulas at the time of AVR. At reoperation for LMCA stenosis, severe ischemia developed in one patient and injury to cardiac structures occurred in four patients. Four patients suffered a perioperative myocardial infarction and congestive heart failure developed in two patients at late follow-up.

CONCLUSIONS

LMCA stenosis following coronary ostial cannulation at the time of AVR is a rare yet morbid complication. Reoperation for this condition is fraught with a high operative morbidity rate and poor long-term outcome. Prevention of this complication is quintessential, avoiding ostial cannulation with self-inflating balloons.

Methicillin-resistant Staphylococcus aureus infection in a cardiac surgical unit

BACKGROUND

Increased antibiotic resistance of common bacteria is attributed in part to the widespread use of various antibiotic agents. Prophylactic and therapeutic antibiotic treatments are routinely used in cardiac surgical units, and it is no surprise that methicillin-resistant Staphylococcus aureus infection is becoming a major cause of surgical infections in cardiac patients.

METHODS

We reviewed our experience with patients who underwent cardiac surgery and experienced infection caused by methicillin-resistant Staphylococcus aureus. Between 1992 and 2000 at the Montreal Heart Institute, 39 patients had methicillin-resistant Staphylococcus aureus surgical infections, and 13,199 patients underwent cardiac surgery. The yearly incidence of methicillin-resistant Staphylococcus aureus infection, the relative risk of acute mediastinitis and of superficial wound infections or other types of methicillin-resistant Staphylococcus aureus infection episodes, and the effect of preventive measures were analyzed.

RESULTS

The annual incidence of methicillin-resistant Staphylococcus aureus acute mediastinitis decreased from 0.37% (5/1321) of cardiac patients in 1992 and 0.44% (6/1355) in 1993 to 0% between 1994 and 1997, 0.13% (2/1528) in 1999, and 0% (0/1700) in 2000. The total incidence of methicillin-resistant Staphylococcus aureus infection, including mediastinitis, superficial and deep sternal and leg wound infection, and all systemic infection episodes ranged from 0.68% of patients in 1992 and 0.96% of patients in 1993 to 0.46% of patients in 1999 and 0.53% of patients in 2000. The relative risk of severe mediastinal methicillin-resistant Staphylococcus aureus infection to all other methicillin-resistant Staphylococcus aureus infection episodes decreased from 1.65 in 1992 to 0.41 in 1999 and 0 in 2000. Beginning in 1993, all patients given a diagnosis methicillin-resistant Staphylococcus aureus infection and all nasal carriers of methicillin-resistant Staphylococcus aureus were strictly isolated on the surgical unit, and vancomycin was used as the prophylactic antibiotic agent for cardiac surgery in these patients. Moreover, since 1998, all patients admitted in the hospital were screened, and nasal carriers were isolated and treated with topical antibiotic ointment.

CONCLUSION

Mediastinal and other infections caused by methicillin-resistant Staphylococcus aureus have a significant morbidity in cardiac surgical patients. After an outbreak of methicillin-resistant Staphylococcus aureus mediastinal infections, several preventive measures to control methicillin-resistant Staphylococcus aureus contamination of surgical patients were implemented (nasal screening, preventive isolation, application of mupirocin, prophylaxis with vancomycin and alcohol gels) and were effective in decreasing the incidence of methicillin-resistant Staphylococcus aureus infection and mediastinitis after cardiac surgery.

Long-term results with triple valve surgery

BACKGROUND

Whether to use biological or mechanical prostheses and whether to repair or replace the tricuspid valve during primary and reoperative triple valve surgery remains controversial. The objective of the present study was to review our experience with primary and reoperative triple valve surgery using CarboMedics (CM) and Carpentier-Edwards (C-E) heart valves.

METHODS

All 73 patients undergoing triple valve surgery since 1982 were prospectively followed at the Montreal Heart Institute valve clinic. Aortic valve replacement was performed with CM prostheses (57 patients) and with C-E prostheses (16 patients). Mitral valve replacement was performed with mechanical prostheses (56 patients) and with biological valves (14 patients). Mitral valve repair was done in 3 patients. Tricuspid valve annuloplasty or commissurotomy or both were performed in 66 patients and the tricuspid valve was replaced in 7 patients. Patient survival, complications, and the type of valve procedures were analyzed.

RESULTS

Thirty patients averaging 62+/-10 years of age underwent primary triple valve surgery and 43 patients averaging 60+/-10 years of age underwent reoperative triple valve surgery (p = 0.5). Tricuspid repair consisted of annuloplasty with the Bex linear reducer (n = 47), the C-E ring (n = 13), or the De Vega technique (n = 5). Tricuspid valve replacement was done using the C-E pericardial prostheses. The 30-day mortality was 17% and 12% in patients with primary and reoperative surgery, respectively (p = 0.5) and patient survival averaged 80%+/-7%, 75%+/-8%, and 41%+/-15%, and 70%+/-7%, 57%+/-9%, and 50%+/-10%, respectively 1, 5, and 10 years following surgery (p = 0.5). The freedom rate from thromboembolism and from bleeding complications were 87%+/-6% and 95%+/-3% in primary and reoperative patients, respectively, 5 years following surgery.

CONCLUSIONS

Triple valve surgery, either as a primary or a reoperative procedure, results in acceptable long-term survival with both mechanical and biological prostheses.

Experience with the 19-mm Carpentier-Edwards pericardial bioprosthesis in the elderly

BACKGROUND

Valve replacement in small aortic root remains a surgical challenge. The objective of this study was to compare results of the 19-mm bioprosthesis with those of larger prostheses in the elderly.

METHODS

The 443 patients, 70 years of age and older, who underwent aortic valve replacement with Carpentier-Edwards pericardial bioprostheses were reviewed.

RESULTS

There were 93 patients with a mean age of 76+/-4 years with implantation of 19-mm prostheses and 350 patients with a mean age of 75+/-4 years with larger bioprostheses. Associated aortoplasty was performed in 10 patients (11%) with 19-mm bioprostheses and in 8 patients (2%) with larger bioprostheses (p = 0.001). There were 11 deaths (12%) within 30 days of surgery in patients with 19-mm prostheses and 22 deaths (6%) among those with larger prostheses (p = 0.1). The 7-year survival rate averaged 61%+/-7% in patients with 19-mm prostheses and 67%+/-4% in those with larger prostheses (p = 0.8). The 7-year freedom rates from all valve-related events averaged 96%+/-2% and 93%+/-2%, respectively (p = 0.6).

CONCLUSIONS

Aortic valve replacement with the 19-mm Carpentier-Edwards pericardial bioprosthesis offers excellent midterm results in the elderly.

Aortic valve replacement with mechanical and biologic prosthesis in middle-aged patients

BACKGROUND

Mechanical prostheses are used in young patients and bioprostheses in the elderly because of the higher rate of structural failure of bioprostheses. The objective of the present study was to compare results after aortic valve replacement with mechanical (Carbo-Medics) and biologic (Carpentier-Edwards pericardial) in middle-aged patients.

METHODS

Five hundred twenty-one patients, aged between 55 and 65 years, who underwent aortic valve replacement with mechanical (n = 363) or biologic (n = 158) prostheses were reviewed.

RESULTS

The 10-year actuarial survival rate averaged 66%+/-6% in patients implanted with mechanical valves compared with 75%+/-4% in patients implanted with biologic valves (p = 0.2). The 10-year freedom rate from thromboembolism, hemorrhage, and endocarditis averaged 92%+/-7%, 97%+/-2%, and 99%+/-1%, respectively, in patients with mechanical valves compared with 91%+/-3% (p = 0.03), 99%+/-1% (p = 0.4), and 95%+/-2% (p = 0.01), respectively, in those with biologic valves. The 10-year freedom rate from all valve-related complications averaged 90%+/-7% and 83%+/-4%, respectively (p = 0.01).

CONCLUSIONS

The freedom rate from all valve-related complications was higher among patients with mechanical valves compared with biologic valves 10 years after aortic valve replacement in middle-aged patients.

Results following valve replacement for ischemic mitral regurgitation

BACKGROUND

Although several authors have favoured mitral repair in ischemic mitral regurgitation (IMR), mitral valve replacement is a valuable option and most often a necessity in patients with structural IMR.

OBJECTIVE

To review the authors' experience with valve replacement for patients with acute and chronic IMR. The effect of preserving the valve leaflets and the subvalvular apparatus during replacement was also evaluated.

PATIENTS AND METHODS

The authors' experience with mitral valve replacement for IMR between 1990 and 1999 was retrospectively analyzed at the Montreal Heart Institute, Montreal, Quebec. Results obtained with mitral valve replacement due to degenerative disease were used for comparative purposes.

RESULTS

Ninety-two patients with IMR and 213 patients with degenerative mitral regurgitation underwent valve replacement with mechanical prostheses (262 of 305 [86%]) or biological prostheses (43 of 305 [14%]). Fifteen patients (15 of 92 [16%]) died within 30 days of mitral valve replacement among IMR patients compared with eight (eight of 213 [4%)] among patients with degenerative mitral valve disease (P=0.01). The seven-year survival average following mitral valve replacement was 66+/-7% in patients with ischemic disease compared with 72+/-4% in patients with degenerative disease (P=0.07). Cardiopulmonary bypass time (odds ratio [OR] 1.01) and emergency operation (OR 2.5) were correlated with the 30-day mortality; the patient's age (OR 1.04) was the only risk factor correlated with the seven-year mortality after valve replacement. The five-year survival of patients with papillary muscle rupture averaged 59+/-12% compared with 78+/-7% in those with functional IMR.

CONCLUSIONS

Preoperative risk factors and higher early mortality in patients with mitral valve replacement for ischemic disease contribute to a lower seven-year survival than with mitral valve surgery for degenerative disease. The short and long term survival of the patients in the acute structural mitral disease subgroup was significantly worse.

Increased incidence of acute ascending aortic dissection with off-pump aortocoronary bypass surgery?

BACKGROUND

An apparent increase in the incidence of acute ascending aortic dissection following off-pump coronary artery bypass grafting (OPCAB) led us to assess retrospectively the rate and circumstances of this complication in our institution on a consecutive series of patients undergoing aortocoronary bypass performed with and without extracorporeal circulation (ECC).

METHODS

A retrospective analysis of acute ascending aortic dissections complicating coronary artery bypass grafting surgery in 3,031 patients in our institution since April 1, 1995, was performed using the database of the Montreal Heart Institute.

RESULTS

There was a greater frequency of hypertension in the OPCAB group. Iatrogenic acute aortic dissection occurred in 3 patients among 308 operated on without ECC (0.97%) and 1 patient among 2,723 operated on under ECC (0.04%). This difference was statistically significant (p < 0.00001).

CONCLUSIONS

The risk of aortic dissection may be increased in OPCAB. Careful manipulation of the aorta with a single side-clamping and a control of the arterial pressure should be used to minimize aortic trauma. High-risk patients should undergo CABG without side-clamping of the aorta or CABG with ECC to prevent this redoubtable complication of myocardial revascularization.

Immediate and long-term results of valve replacement for native and prosthetic valve endocarditis

BACKGROUND

The objective of the present study was to compare current results of prosthetic valve replacement following acute infective native valve endocarditis (NVE) with that of prosthetic valve endocarditis (PVE). Prosthetic valve replacement is often necessary for acute infective endocarditis. Although valve repair and homografts have been associated with excellent outcome, homograft availability and the importance of valvular destruction often dictate prosthetic valve replacement in patients with acute bacterial endocarditis.

METHODS

A retrospective analysis of the experience with prosthetic valve replacement following acute NVE and PVE between 1988 and 1998 was performed at the Montreal Heart Institute.

RESULTS

Seventy-seven patients (57 men and 20 women, mean age 48 +/- 16 years) with acute infective endocarditis underwent valve replacement. Fifty patients had NVE and 27 had PVE. Four patients (8%) with NVE died within 30 days of operation and there were no hospital deaths in patients with PVE. Survival at 1, 5, and 7 years averaged 80% +/- 6%, 76% +/- 6%, and 76% +/- 6% for NVE and 70% +/- 9%, 59% +/- 10%, and 55% +/- 10% for PVE, respectively (p = 0.15). Reoperation-free survival at 1, 5, and 7 years averaged 80% +/- 6%, 76% +/- 6%, and 76% +/- 6% for NVE and 45% +/- 10%, 40% +/- 10%, and 36% +/- 9% for PVE (p = 0.003). Five-year survival for NVE averaged 75% +/- 9% following aortic valve replacement and 79% +/- 9% following mitral valve replacement. Five-year survival for PVE averaged 66% +/- 12% following aortic valve replacement and 43% +/- 19% following mitral valve replacement (p = 0.75). Nine patients underwent reoperation during follow-up: indications were prosthesis infection in 4 patients (3 mitral, 1 aortic), dehiscence of mitral prosthesis in 3, and dehiscence of aortic prosthesis in 2.

CONCLUSIONS

Prosthetic valve replacement for NVE resulted in good long-term patient survival with a minimal risk of reoperation compared with patients who underwent valve replacement for PVE. In patients with PVE, those who needed reoperation had recurrent endocarditis or noninfectious periprosthetic dehiscence.

Reinfusion of mediastinal blood after heart surgery

BACKGROUND

Several authors studying autotransfusion of shed mediastinal blood in patients undergoing heart operations have published conflicting results regarding reduction of the need for homologous blood transfusion. The effect on coagulation parameters is also unclear.

METHODS

In a prospective randomized study, 198 patients who underwent coronary artery bypass grafting or a valvular operation were divided into 2 groups: a group with autotransfusion of shed mediastinal blood after an operation and a control group. Continuous reinfusion of mediastinal blood was done until no drainage was present or for a period of 12 hours after the operation. The amount of blood lost and autotransfused, the number of homologous blood products transfused, and the coagulation parameters were monitored.

RESULTS

The number of patients requiring homologous blood transfusion was significantly different between the 2 groups (54/98 [55%] in autotransfused patients vs 73/100 [73%] in the control group, P =.01). The number of re-explorations for excessive bleeding was similar in the 2 groups (7/98 [7.1%] vs 8/100 [8%]), but the amount of blood collected postoperatively was higher in the autotransfused patients compared with control patients (1200 +/- 201 mL vs 758 +/- 152 mL, P =.0007). Coagulation parameters analyzed and complication rates were similar in the 2 groups after the operations.

CONCLUSION

Autotransfusion of shed mediastinal blood reduces the need for homologous blood transfusion in patients undergoing various cardiac operations. The cause of increased shed blood in patients undergoing autotransfusion remains unclear.

[Isolated tricuspid valve replacement. Long-term results]

The purpose of this study was to examine the early and late results in 29 patients who underwent 32 (6 mechanical and 26 bioprostheses) isolated tricuspid valve replacement (TVR) from a total of 79 TVR and 375 tricuspid annuloplasties performed at the Montréal Heart Institute, between January 1978 and January 1998. Patients' ages ranged from 25 to 70 years (mean 48 years), and 62% were females. Twenty-seven patients (84%) were in New York Heart Association (NYHA) functional class III and IV. Previous valve surgery had been performed in 22 patients (69%) of which 9 had undergone TVR. Postoperatively, permanent pacemaker was implanted in 9 patients (28%), and immediate reoperation was required in 2 patients because of bleeding. Mean follow-up period was 67.7 months (93% complete). Serial echocardiography showed 3 prosthesis dysfunctions, leading to a second replacement in 2 patients at 12.8 and 7.7 years after initial surgery. All but three patients showed an improvement of their NYHA class. Hospital mortality occurred in 6 patients (19%) and 7 patients died during late follow-up: mean 38.1 months after surgery, including one valve-related death (mechanical valve thrombosis). Actuarial survival rate of all patients was 63% after 5 years, and 47% after 10 years. Isolated TVR remains a high-risk procedure. Most survivors, however, should expect a better quality of life with improvement in their NYHA class.

Endoscopic saphenectomy for coronary artery bypass surgery: comparison of two techniques with and without carbon dioxide insufflation

OBJECTIVE

To compare the clinical results of an initial experience with two techniques of endoscopic saphenectomy with and without gas insufflation.

DESIGN

A retrospective study was performed between September 1998 and March 1999 on 40 patients who underwent endoscopic saphenectomy for coronary artery bypass graft without (group 1, n=15) and with (group 2, n=25) carbon dioxide insufflation.

INTERVENTIONS

In both groups, the site of harvesting was at the knee through a 2 cm incision. In group 1, dissection was performed using a hand-held dissector while in group 2 dissection was performed after ensuring that there was a seal at the knee and insufflation of carbon dioxide. Collaterals were controlled with an endoclipper in group 1 and bipolar scissors in group 2. Intraoperative procedure time, length of the harvested vein and aspect of the thigh (ecchymosis, hematoma, infection) were recorded.

RESULTS

Vein trauma occurred in four patients in group 1 (four of 15, 27%) and in one in group 2 (one of 25, 4%). Hematomas developed in four patients in group 1 (four of 15, 27%) and in one patient in group 2 (one of 25, 4%). Wound infection occurred in no patients in group 1 and in one patient in group 2. One patient in group 2 suffered carbon dioxide embolism with no untoward consequences. Conversion to an open technique was necessary in five patients in group 1 (five of 15, 33%) and in two patients in group 2 (two of 25, 8%).

CONCLUSIONS

Endoscopic saphenectomy both with and without carbon dioxide insufflation is associated with a low infection rate, but vein trauma and wound hematomas are more common without carbon dioxide insufflation.

Factors predictive of oxygen consumption during the immediate postoperative period in open heart surgery

BACKGROUND

Postoperative oxygen consumption (VO2) is critical during the recovery period that follows open heart surgery and depends on patient characteristics and surgical factors.

OBJECTIVE

To explore the surgical and patient-related factors that may influence VO2 during the early postoperative period.

DESIGN

Prospective study.

SETTING

Postoperative intensive care unit.

PATIENTS

Study participants were 50 consecutive patients undergoing elective open heart surgery. There were 39 men and 11 women, with a mean age of 58+/-10 years.

MEASUREMENTS AND MAIN RESULTS

VO2, oxygen extraction and arterial lactate were measured 1, 4, 12 and 24 h postoperatively. VO2 increased significantly during the first 12 h and stabilized thereafter. Oxygen extraction remained stable through the first 24 h. Covariance analysis on repeated measures showed that the extracorporeal circulatory period (P<0.01), age (P<0.01), body temperature (P<0.05) and use of noradrenalin (P<0.05) were predictive factors influencing postoperative VO2. Although arterial lactate increased significantly during the first 12 h period, no correlation with VO2 was found. However, covariance analysis showed that female sex, patient age (older than 65 years) and bypass period were positive correlating factors for the increase in arterial lactate.

CONCLUSIONS

Patient VO2 need is decreased early after open heart surgery and returns to normal after 12 h. Surgical and patient-specific factors are responsible for these changes. Arterial lactate measurements were not found to be reliable indexes of VO2 need during this period.

Clinical outcome after isolated tricuspid valve replacement: 20-year experience

OBJECTIVE

To examine the early and late results of isolated tricuspid valve replacement (TVR).

DESIGN AND SETTING

All isolated TVRs performed at the Montreal Heart Institute, Montreal, Quebec between January 1978 and January 1998 were retrospectively reviewed. Follow-up data on patients were obtained through the valve clinic.

PARTICIPANTS

From a total of 79 TVR and 375 tricuspid annuloplasties performed during the study period, 29 patients who underwent 32 isolated TVRs (six mechanical valves and 26 bioprostheses) were included. Patient age ranged from 25 to 70 years (mean 48), and 62% were female. Twenty-seven patients (84%) were in New York Heart Association (NYHA) functional classes III and IV. Previous valve surgery had been performed in 22 patients (69%) among whom nine had undergone TVR.

RESULTS

Postoperatively, a permanent pacemaker was implanted in nine patients (28%), and reoperation because of bleeding was required in two patients. Mean follow-up was 67.7 months (93% complete). Serial echocardiography showed prosthesis dysfunction in three patients, requiring two valve re-replacements at 12.8 and 7.7 years after initial surgery. All patients, except three, showed an improvement of their NYHA class. Six patients (19%) died in hospital and seven patients died during late follow-up at a mean of 38.1 months after surgery, including one valve-related death (mechanical valve thrombosis). The actuarial survival rate of all patients was 63% after five years and 47% after 10 years.

CONCLUSION

Isolated TVR remains a high risk procedure. Most survivors, however, should expect a better quality of life by the improvement in their NYHA class.

[Results of surgery after failed mitral percutaneous dilatation]

OBJECTIVES

Percutaneous balloon mitral valve commissurotomy (BMC) is an alternative to surgical commissurotomy. Complications following BMC includes mitral regurgitation, iatrogenic atrial septal defect, residual mitral stenosis, and pericardial hemorrhage. This study analyzes the outcomes of surgery following failed BMC for mitral stenosis.

METHODS

In a series of 298 patients treated with BMC, 53 patients (17.7%) had a complication that necessitated a surgical treatment. Twenty-eight patients needed an immediate surgery before the discharge (group I) and 25 patients were operated on an elective basis (group II).

RESULTS

In group I, 27 patients have been operated and one died before the operation. In 21 patients an acute mitral regurgitation occurred, 3 patients had a residual mitral stenosis, and 3 had a left atrial perforation. The operation consisted of 26 mitral valve replacements, 20 concomitant reparations of iatrogenic atrial septal defect, and one open mitral valve commissurotomy. Operative mortality was 3.7% (1 out of 27). In group II, 25 patients have been operated at a mean 18 +/- 14 months after BMC. In the 25 patients the operation was indicated for significant mitral regurgitation (2 + and more). The operation consisted of 25 mitral valve replacements, 9 concomitant reparations of iatrogenic atrial septal defect, 3 patients had also coronary artery bypasses. The operative mortality was 8% (2 out of 25). The echocardiographic score was similar for both groups, it was 8.4 +/- 2.0 in group I and 8.0 +/- 1.5 in group II (P = NS). Despite these complications following failed BMC, surgery appears a safe procedure with an acceptable mortality.

Comparison of long-term clinical results of double versus single internal mammary artery bypass grafting

BACKGROUND

The long-term benefits of double versus single internal mammary artery (IMA) coronary bypass grafting have not yet been established.

METHODS

Six hundred patients were studied retrospectively 10 years after coronary revascularization using saphenous vein grafts (SVGs) only or single or double IMA grafts.

RESULTS

Patients with double IMA grafts were younger and were more likely to have diabetes, left main coronary stenosis, and three-vessel coronary artery disease than patients with SVGs or single IMA grafts. Patients with SVGs and double IMA grafts had a greater number of diseased coronary vessels and a greater number of coronary bypass grafts per patient than patients with single IMA grafts (mean +/- SEM, 2.8 +/- 1.0, 2.8 +/- 0.7, 2.1 +/- 0.8 grafts per patient, respectively, p < 0.0001). Actuarial survival rates 10 years after placement of SVGs and single and double IMA grafts averaged 83% +/- 6%, 90% +/- 4%, and 87% +/- 8%, respectively (p = 0.03). Cox regression analysis showed that diabetes (relative risk, 2.03; 95% confidence interval, 1.55 to 2.66) and chronic pulmonary obstructive disease (relative risk, 2.20; 95% confidence interval, 1.58 to 3.80) increased, whereas an IMA graft on the left anterior descending coronary artery significantly decreased, the risk of death after operation (relative risk, 0.45; 95% confidence interval, 0.36 to 0.57) throughout the follow-up period.

CONCLUSIONS

Use of an IMA graft on the left anterior descending coronary artery improves survival compared with use of an SVG. Although patients with double IMA grafts had a greater number of poor prognosis risk factors before operation, their 10-year survival rate was similar to that of patients with a single IMA graft.

Massive gastrointestinal hemorrhage after transoesophageal echocardiography probe insertion

PURPOSE

To describe a case of a massive gastric bleeding following emergency coronary artery bypass surgery associated with transoesophageal echocardiographic (TEE) examination.

CLINICAL FEATURES

A 50-yr-old man was referred for an acute myocardial infarction and pulmonary edema (Killip class 3). Twelve hours after his myocardial infarction, he was still having chest pain despite an i.v. heparin infusion. Coronary angiography revealed severe three-vessel disease with multifocal stenosis of the left anterior descending, circumflex and total occlusion of the right coronary artery. The patient was transferred to the operating room for emergency coronary artery bypass graft surgery. After total systemic heparinization (3 mg.kg-1) was obtained for cardiopulmonary bypass, a multiplane TEE probe was inserted without difficulty to monitor myocardial contractility during weaning from CPB. During sternal closure, the TEE probe was removed and an orogastric tube was inserted with immediate drainage of 1,200 ml red blood. Endoscopic examination demonstrated a mucosal tear near the gastro-oesophageal junction and multiple erosions were seen in the oesophagus. These lesions were successfully treated with submucosal epinephrine injections and the patient was discharged from the hospital eight days after surgery.

CONCLUSION

This is a report of severe gastrointestinal hemorrhage following TEE examination in a fully heparinized patient. This incident suggest that, if the use of TEE is expected, the probe should preferably be inserted before the administration of heparin and the beginning of CPB.

[Influence of carotid atheroma on the neurologic status after myocardial revascularization]

Surgical management of the carotid disease remains controversial in patients affected with coronary artery atheromatous disease. We report the Montreal Heart Institute experience on the influence of carotid disease on postoperative neurologic events of 501 consecutive patients operated on for coronary revascularization during the period from January 1994 to December 1994. There were 381 men and 114 women averaging 62 +/- 9 years old. Major risk factors were high blood pressure (35%), and smoking habit (48%). Fifty-nine patients presented clinical signs of carotid atheromatosis and among them 21 had significant carotid stenosis (> 80% decrease of cross sectional area). During surgery, the mean duration of extracorporeal circulation (ECC) was 76 +/- 31 minutes and the mean perfusion pressure (MPP) was 70 +/- 11 mmHg. The use of inotropic drugs was mandatory in 26% of the cases and the mean arterial lactate (AL) dosage during ECG was 3.07 +/- 1.35 mM/L. During the perioperative period, 13 (2.5%) patients sustained neurologic disturbances of which 5 (1%) were lateralized. Among them, 8 completely recovered whereas 3 of the 5 with permanent damage died. None of the patients with preoperative stigmata of carotid disease experienced lateralized neurologic deficit. Multivariate regression analysis identified the use of vasopressor drugs and perioperative increase of AL as predictive factors. We conclude that in our series, the incidence of neurologic complications was low. The presence of carotid atheromatosis did not increase the postsurgical risk of cerebrovascular accident, however, the increased incidence of neurologic events associated with inotropic drugs and increased AL suggests a direct link with a systemic oxygen debt. Consequently, we do no recommend concurrent prophylactic surgery during coronary artery revascularization.

[Clinical results of peroperative transesophageal echography in peri-valvular leaks of heart prosthesis]

Perivalvular leaks following prosthetic valve replacement are associated with significant morbidity. Management has classically consisted of valve replacement or blind surgical repair. Our study examines the results of intraoperative transesophageal echo-guided repair of perivalvular leaks (ITEGR). Between November 24, 1987 and January 1st, 1996, 23 patients (10 men, 13 women) at the Montreal Heart Institute underwent ITEGR. Ninety percent were NYHA class III-IV preoperatively. Seventy to 85% had significant cardiac insufficiency preoperatively. Eighty-six percent of the leaks were in the mitral valve location, 90% of which were mechanic prosthesis. Eighty-nine percent of patients had hemolysis with an average LDH of 720. Mean bypass time was 125 minutes with a mean clamp time of 77 minutes. Most patients were undergoing a third operation at the time of repair. Operative mortality was 8%, all due to biventricular failure. A mean follow-up of 67 months showed a late death of 10%. Of the 19 survivors, 77% were NYHA class I-II. Overall mortality was 20%. In our institution valve re-replacement in similar circumstances was associated with an operative and long-term mortality of 7% and 26% respectively. We conclude that intraoperative transesophageal echo-guided repair is an excellent management alternative in patients with perivalvular leaks with decreased late and overall mortality.

[Revascularization of the circumflex artery with mechanical stabilization: initial experience]

OBJECTIVES

To evaluate the short-term result of the coronary artery revascularization without cardiopulmonary bypass for triple vessel disease, including the circumflex territory performed on the stabilized beating heart.

METHODS

Prospective study conducted on the first 35 consecutive patients with triple vessel disease operated upon without cardiopulmonary bypass by a single surgeon (RC) at the Montreal Heart Institute between October 1996 and March 1997.

RESULTS

Mean age of patients was 64 +/-1.6 years and the majority were men (30). Most common risk factors were hypercholesterolemia (65%) and familial history (55%) of ischemic heart disease. Main surgical indication was unstable angina (74%) and mean preoperative left ventricular ejection fraction was 53 +/- 3%. Hundred and twelve bypass were constructed averaging 3.2 +/- 0.1 grafts/patients of which 39 were made on branches of the circumflex artery. Average ischemic time was 34.17 +/- 2.17 minutes. The internal thoracic artery, saphenous vein, and radial artery were used as a vascular conduit in 44, 67, and 1 occasions respectively. There was one operative mortality, and one non Q perioperative myocardial infarction (CK-MB: 89 U/L). No patient required aortic counterpulsation balloon assistance. The average postoperative CK-MB (U/L) were 12.2 +/- 1.9, 15.2 +/- 3.2, and 10.3 +/- 1.7 at 1, 24 and 48 hours respectively. During the post-operative period 26% (9) of the patients presented atrial fibrillation, 6.5% (2) early reexploration for bleeding, and 63% (22) did not require transfusion. Average stay in hospital was 6.1 +/- 45 days. Coronary grafts were angiographically assessed in the first 10 patients and at the postmortem exam in one and displayed a 100% patency with 93.5% (29/31) adequate runoff.

CONCLUSION

Triple vessel coronary artery disease revascularization is feasible on the beating heart without cardiopulmonary bypass with excellent short-term clinical and angiographic results.

Triple coronary artery revascularization on the stabilized beating heart: initial experience

OBJECTIVE

To decrease health costs and morbidity related to extracorporeal circulation, surgeons have modified the coronary artery bypass (CAB) technique so that it can be completed without the use of extracorporeal circulation. This study summarizes initial experience with direct coronary artery revascularization on the beating heart using a coronary stabilizer.

DESIGN

A case series.

SETTING

The Montreal Heart Institute, a university-affiliated centre, specializing in the treatment of cardiac illnesses.

PATIENTS

Ten patients underwent CAB by this technique. They presented with double or triple coronary artery disease with no intramyocardial, heavily calcified, diffused atheromatous coronary vessels, or left main coronary disease.

INTERVENTION

CAB grafting in the beating heart. The anterior wall was grafted in all patients, the inferior wall in 7 and the posterior wall in 7.

MAIN OUTCOME MEASURES

Patient survival and graft patency.

RESULTS

One patient died of multiple organ failure not related to the grafting technique itself, and 1 patient suffered a non-Q myocardial infarction. Early coronary angiography performed on 8 patients showed 100% graft patency, most with excellent distal runoff (21/22 grafts).

CONCLUSION

In patients with adequate anatomy, performance of CAB without extracorporeal circulation can achieve excellent early results provided there is appropriate mechanical stabilization of the beating heart.

Changing flow pattern of the internal thoracic artery undergoing coronary bypass grafting: continuous-wave Doppler assessment

Surgeons have limited ability to evaluate intraoperatively the patency of internal thoracic artery graft as a bypass for coronary artery revascularization. We used continuous-wave Doppler ultrasonography to study the velocity of the internal thoracic artery before harvesting and after grafting (scanning probe, 8 MHz). Systolic and diastolic frequency shift (in kilohertz) and systolic frequency/diastolic frequency index were analyzed. Twenty four internal thoracic artery grafts in 15 patients were studied. Fourteen internal thoracic artery grafts were anastomosed to the left anterior descending artery, one to a diagonal artery, and nine to the circumflex artery. The mean systolic frequency before harvesting was 1.19 +/- 0.40 KHz and no significant differences were found between the right and the left internal thoracic artery (right, 1.17 +/- 0.37; left, 1.19 +/- 0.42 KHz). There was a 40% drop in systolic frequency related to the harvesting. Mean systolic frequency decreased after grafting (1.19 +/- 0.40 versus 0.87 +/- 0.32 KHz; p < 0.01) whereas mean diastolic frequency doubled (0.32 +/- 0.12 versus 0.83 +/- 0.4 KHz; p < 0.001) and mean diastolic frequency/systolic frequency index increased from 28% +/- 11% to 101% +/- 39% (p < 0.001), indicating an increased myocardial vascularization during diastole. No significant difference was found between grafted arteries (left anterior descending versus circumflex). All patients had an uneventful postoperative course and no perioperative myocardial infarction was reported. Doppler flow quantification of internal thoracic artery bypasses may give the surgeon an opportunity to evaluate intraoperatively the physiologic features and patency of the internal thoracic artery before and after coronary artery bypasses.

Clinical experience with the right gastroepiploic artery in coronary artery bypass grafting

The excellent long-term results with the internal mammary artery for coronary artery bypass grafting have prompted the search for other conduits with similar characteristics. From December 1989 to December 1991, the right gastroepiploic artery (RGEA) has been used as an in situ graft to the posterior descending coronary artery in 51 patients at the Montreal Heart Institute. The patients' age averaged 50 +/- 11 years. Three-vessel coronary artery disease was present in 41 patients and two-vessel disease in the remaining 10 patients. In all but 1 patient, bilateral internal mammary artery grafting was performed in addition to RGEA grafting. The number of grafts per patient averaged 3.2 +/- 0.8. There was no operative mortality. Morbidity was minimal with only myocardial infarction and a pleural effusion in 1 patient. In 1 patient, a splenectomy had to be performed because of iatrogenic tear during dissection of the RGEA. The average hospital stay was 8.2 +/- 2.6 days. Enteral nutrition was resumed on average 2 days after operation. Angiographic evaluation of RGEA grafts was performed before discharge or within the first month after surgery in 31 patients. In 28 patients (28/31, 90%) the RGEA graft was patent, two grafts were occluded, and in the remaining patient, the graft could not be visualized due to technical difficulties during angiography. A second angiographic evaluation was performed in 5 patients, 1 year after operation. Four RGEAs were patent and 1 was occluded. Clinical follow-up averaged 4 months (range 1 to 15 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Transluminal angioplasty of the subclavian artery in patients with internal mammary grafts

From January 1987 to January 1992, 11 patients underwent percutaneous transluminal angioplasty (PTA) for the treatment of subclavian artery stenosis before or after coronary artery bypass grafting (CABG) using the internal mammary artery (IMA). There were 8 men and 3 women, with a mean age of 57 +/- 7 years. Four patients had PTA 1 to 4 months before undergoing CABG with IMA grafts, because of either asymptomatic supraclavicular murmurs or neurologic symptoms. Seven patients underwent PTA 2 to 37 months after CABG with IMA grafts, because of recurrent angina. Subclavian artery stenosis was on the left side in 9 patients, the right side in 1 patient, and bilateral in 1 patient. Ten PTA procedures were successful in 9 patients. All patients with post-CABG angina had reversal of the ischemia. There were three complications: one femoral artery thrombosis, one brachial plexus hematoma after an axillary approach, and one acute pulmonary edema after the procedure. Follow-up after PTA ranged from 1 to 60 months (mean, 38 +/- 17 months). Nine patients had no angina at follow-up and 2 had stable angina (class II) upon exertion. Upper-limb Doppler studies showed no evidence of restenosis in any of these patients at a mean follow-up of 38 months. Subclavian artery PTA is a useful alternative to IMA bypass grafting in patients with subclavian artery stenosis discovered preoperatively, and it is the treatment of choice for those presenting with post-CABG angina due to subclavian artery stenosis proximal to an IMA graft.

Morbidity and mortality of reoperation for coronary artery bypass grafting: significance of atheromatous vein grafts

Reoperation ('redo') for coronary artery disease shows a significant increase in morbidity and mortality compared to primary surgery. Some technical approaches have been advocated to decrease myocardial injury, presumably due to coronary artery embolization from atheromatous vein grafts. From 1984 to 1989, 321 'redo' operations were performed at the Montreal Heart Institute. Patients with patent and atherosclerotic vein grafts at preoperative coronary angiography (239 patients) were compared to those with normal or occluded grafts (82 patients). Perioperative myocardial infarction and death rates were 19% and 13%, respectively. They were particularly high among patients with three or more patent and atherosclerotic vein grafts at reoperation (32% and 29%, respectively). Among the 239 patients with patent atherosclerotic grafts, the results of three different surgical techniques were studied retrospectively. A first group of 66 patients had early ligation of patent atheromatous grafts before cardioplegia was administered by antegrade infusion during single aortic clamping for coronary anastomoses, and maintained for the confection of aortic anastomoses. In a second group of 35 patients, early ligation of diseased graft, antegrade cardioplegic delivery, and partial aortic cross clamping for aortic anastomoses of vein grafts was done. In the third group of 138 patients, venous grafts were not interrupted before antegrade cardioplegic infusion and partial aortic cross clamping for aortic anastomoses of vein grafts was used. No significant difference in hospital mortality or perioperative myocardial infarction rate was observed between the three groups of patients. Thus, the modified techniques so far recommended for repeat coronary artery bypass grafting, such as early ligation of patent atherosclerotic grafts, have failed to improve the early results of 'redo' operations.

Association of protein amount polymorphism (PAP) among maize lines with performances of their hybrids

It has been suggested that molecular foundations of phenotypic diversity reside in the variability of genome expression. This variability can be appraised through the polymorphism of individual protein amounts (PAP: protein amount polymorphism). Eight maize inbred lines and ten of their single-cross hybrids were analyzed by two-dimensional polyacrylamide gel electrophoresis in order to examine the potential of PAP for predicting hybrid vigor. The 28 possible pairs of lines were characterized for: (i) the number, H of expected heterozygous structural loci in their hybrid, in the sample of loci revealed by 2D-PAGE; (ii) four distance indices based on PAP; (iii) the hybrid values for five agromorphological characters measured in four different year/locations. For the subset of ten hybrids analyzed by 2D-PAGE, the number of cases of nonadditive inheritance (NA) was also counted. Whereas H appeared to be related neither to the PAP indices, nor to NA, nor to hybrid performances, PAP indices were correlated to NA, and both were positively associated to hybrid performances. The possibility that PAP is responsible for quantitative trait variation is discussed. This could result in the definition of biological predictors of heterosis.

Long term follow-up after portacaval shunt and internal mammary coronary bypass graft in homozygous familial hypercholesterolemia: report of two cases

Homozygous familial hypercholesterolemia (HFH) is characterized by a very shortened lifespan, mainly due to cardiac events, and by resistance to conventional lipid lowering therapies. Two patients are described for whom a combination of portacaval shunt and mammary coronary bypass graft were done with good long term success. A review of the actual forms of treatment of HFH is made. To the authors' knowledge, there is no report in the literature of this double surgical approach.

Attitudes of French-Canadian university students toward use of condoms: a structural analysis

164 French-Canadian university students took part in a study analyzing the factorial pattern of attitudes toward the use of condoms. A principal component analysis identified 7 factors, namely, positive general attitude toward use of condoms, contraceptive security, inhibition of sexual pleasure, inconvenience, embarrassment, responsibility, and lessening of physical pleasure.