Long-Term Results of the RAPCO Trials

Background:

An internal thoracic artery graft to the left anterior descending artery is standard in coronary bypass surgery, but controversy exists on the best second conduit. The RAPCO trials (Radial Artery Patency and Clinical Outcomes) were designed to compare the long-term patency of the radial artery (RA) with that of the right internal thoracic artery (RITA) and the saphenous vein (SV).

Methods:

In RAPCO-RITA (the RITA versus RA arm of the RAPCO trial), 394 patients <70 years of age (or <60 years of age if they had diabetes mellitus) were randomized to receive RA or free RITA graft on the second most important coronary target. In RAPCO-SV (the SV versus RA arm of the RAPCO trial), 225 patients ≥70 years of age (or ≥60 years of age if they had diabetes mellitus) were randomized to receive RA or SV graft. The primary outcome was 10-year graft failure. Long-term mortality was a nonpowered coprimary end point. The main analysis was by intention to treat.

Results:

In the RA versus RITA comparison, the estimated 10-year patency was 89% for RA versus 80% for free RITA (hazard ratio for graft failure, 0.45 [95% CI, 0.23–0.88]). Ten-year patient survival estimate was 90.9% in the RA arm versus 83.7% in the RITA arm (hazard ratio for mortality, 0.53 [95% CI, 0.30–0.95]). In the RA versus SV comparison, the estimated 10-year patency was 85% for the RA versus 71% for the SV (hazard ratio for graft failure, 0.40 [95% CI, 0.15–1.00]), and 10-year patient survival estimate was 72.6% for the RA group versus 65.2% for the SV group (hazard ratio for mortality, 0.76 [95% CI, 0.47–1.22]).

Conclusions:

The 10-year patency rate of the RA is significantly higher than that of the free RITA and better than that of the SV.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT00475488.

Changes in the management of deep sternal wound infections: a 12-year review

BACKGROUND

Deep sternal wound infection (DSWI) is a rare but life-threatening complication following cardiac surgery associated with increased morbidity and mortality. Management of these patients has evolved over the years and can include sternal rewiring, mediastinal irrigation, negative-pressure wound therapy (NPWT) dressing or repair with flaps. We reviewed changes in our management of DSWI and outcomes.

METHODS

Using the Australian and New Zealand Society of Cardiac and Thoracic Surgeons database, 5472 underwent cardiac surgery at St Vincent's Hospital, Melbourne, and 42 were identified as developing DSWI requiring re-operation between June 2002 and September 2014. Data were collected pertaining to risk factors for DSWI, management strategies and outcomes. Patients were compared from a period prior to NPWT dressing use (June 2002-February 2006, n = 14) and since the NPWT has been used regularly in the management of DSWI (from March 2006, n = 28). Patients were also compared based on the requirement for flap closure of their sternal wound.

RESULTS

Because of the widespread use of NPWT dressings, there is a trend towards fewer sternal infections requiring flap closure (25 versus 42.8%) and less post-operative complications after definitive closure (7.1 versus 28.6%). Before and after widespread NPWT use, patients require similar number of re-operations before closure and have no significant differences in time to definitive closure or length of hospital stay.

CONCLUSION

The use of NPWT dressings as a bridge to definitive closure may reduce the need for more burdensome flap reconstruction, does not delay definitive reconstruction or prolong hospital stay and may reduce post-reconstruction complications requiring re-operation.

Is the radial artery associated with improved survival in older patients undergoing coronary artery bypass grafting? An analysis of a multicentre experience†

OBJECTIVES

Studies suggest that the radial artery (RA) may exhibit superior patency compared with the saphenous vein (SV). It is unclear whether older patients undergoing coronary artery bypass grafting (CABG) derive any survival benefit from the use of RAs. We sought to evaluate this using a multicentre database.

METHODS

From 1995 to 2010, 6059 patients with three-vessel coronary artery disease underwent primary isolated CABG at 8 centres. A study cohort of 4006 patients was formed with 3220 (80%) receiving at least 1 RA to supplement a single in situ internal thoracic artery (RA group) while 786 (20%) received only veins to supplement a single ITA (SV group). In the RA group, bilateral RAs were used in 1418 (44%) cases, while total arterial revascularization was achieved in 1859 (58%). RAs were mostly grafted to the left circumflex and right coronary territories. Survival data were obtained using the National Death Index and propensity-score matching was used for risk adjustment. Separate propensity-score analyses were conducted for the 2149 patients (1645 RA, 504 SV) who were 70 years or older.

RESULTS

Patients receiving RAs were younger (mean age in years RA: 68 ± 9.7 vs SV: 71 ± 7.9, P < 0.001) and less likely to have cerebrovascular disease, obstructive airways disease, myocardial infarction within 7 days and left-main coronary disease. At 30 days, RA patients experienced reduced unadjusted mortality (49 of 3220, 1.5% vs 25 of 786, 3.2%, P = 0.004). At 15 years, the RA group showed superior unadjusted survival (51 ± 1.1 vs 35 ± 1.9%, P < 0.001). After propensity-score matching of 507 patient pairs, there was comparable 30-day mortality between groups (RA: 9, 1.8 vs SV: 14, 2.8%, P = 0.41). However, at 15 years, the RA group still showed superior survival (42 ± 2.6 vs 35 ± 2.5%, P = 0.008). Among those 70 years and older (327 matched pairs), despite similar 30-day mortality (RA: 6, 1.8% vs SV: 10, 3.1%, P = 0.42), RA patients again exhibited improved survival (35 ± 3.3 vs 22 ± 2.8%, P = 0.004) at 15 years.

CONCLUSIONS

This multicentre analysis suggests that the use of an RA is associated with a survival benefit in older patients undergoing CABG.

Total arterial revascularization with internal thoracic and radial artery grafts in triple-vessel coronary artery disease is associated with improved survival

OBJECTIVES

We sought to evaluate our experience with total arterial revascularization and compare it with the traditional approach of a single internal thoracic artery supplemented by saphenous veins.

METHODS

From 1995 to 2010, 6059 patients with triple-vessel coronary artery disease underwent primary isolated coronary artery bypass grafting at 8 centers. A study cohort of 3774 patients was formed, with 2988 (79%) undergoing total arterial revascularization and 786 (21%) receiving only saphenous veins to supplement a single in situ internal thoracic artery. In the total arterial revascularization group, bilateral internal thoracic arteries were used in 1079 patients (36%) and at least 1 radial artery was used in 2916 patients (97%). Propensity score matching was used for risk adjustment.

RESULTS

Patients undergoing total arterial revascularization were younger (65.0±10.4 years vs 71.3±7.9 years, P<.001) and less likely to have diabetes, cerebrovascular disease, recent myocardial infarction, and severe left ventricular impairment. At 15 years, patients who underwent total arterial revascularization experienced superior unadjusted survival (62%±1.1% vs 35%±1.9%, P<.001). Multivariable Cox regression in the entire study cohort showed the total arterial group had improved survival with a hazard ratio of 0.79 (95% confidence interval, 0.70-0.90; P<.001). After propensity score matching yielded 384 patient pairs, patients who underwent total arterial revascularization showed improved survival at 15 years than patients who underwent single arterial revascularization (54%±3.3% vs 41%±3.0%, P=.0004).

CONCLUSIONS

This large multicenter study suggests that a strategy of total arterial revascularization is associated with improved long-term survival compared with the use of only a single arterial and saphenous vein grafts. Total arterial revascularization should be encouraged in patients with a reasonable life expectancy.

The operating surgeon is an independent predictor of chest tube drainage following cardiac surgery

OBJECTIVES

Bleeding into the chest is a major cause of blood transfusion and adverse outcomes following cardiac surgery. The authors investigated predictors of bleeding following cardiac surgery to identify potentially correctable factors.

DESIGN

Data were retrieved from the medical records of patients undergoing cardiac surgery over the period of 2002 to 2008. Multivariate analysis was used to identify the independent predictors of chest tube drainage.

SETTING

Tertiary hospital.

PARTICIPANTS

Two thousand five hundred seventy-five patients.

INTERVENTIONS

Cardiac surgery.

RESULTS

The individual operating surgeon was independently associated with the extent of chest tube drainage. Other independent factors included internal mammary artery grafting, cardiopulmonary bypass time, urgency of surgery, tricuspid valve surgery, redo surgery, left ventricular impairment, male gender, lower body mass index and higher preoperative hemoglobin levels. Both a history of diabetes and administration of aprotinin were associated with reduced levels of chest tube drainage.

CONCLUSIONS

The individual operating surgeon was an independent predictor of the extent of chest tube drainage. Attention to surgeon-specific factors offers the possibility of reduced bleeding, fewer transfusions, and improved patient outcomes.

The 'down-under repair' for ischaemic mitral regurgitation

Current surgical management of restrictive ischaemic mitral regurgitation (IMR) includes mitral valve annuloplasty (MVA) using an undersized ring when the mechanism is secondary to leaflet restriction. In our experience, MVA alone is inadequate to eliminate mitral incompetence in these patients. We report the 'Down-Under Repair' as an adjunctive concept for the treatment of a subset of patients with restrictive IMR and associated inferobasal left ventricular aneurysm. The 'Down-Under Repair' reduces mitral leaflet restriction by approximating the origin of the posterior papillary muscle towards the mitral annulus. Midterm results demonstrated sustained valvular competence and symptomatic improvement.

Choice of conduit for the right coronary system: 8-year analysis of Radial Artery Patency and Clinical Outcomes trial

BACKGROUND

Previous reports have supported the use of bilateral internal thoracic arteries to revascularize the left coronary circulation. If this becomes standardized practice, the optimal conduit for the right coronary system remains to be established. Our objective is to compare the performance of the radial artery versus the saphenous vein when used to graft the right coronary artery or its branches during an 8-year period after primary coronary artery bypass graft surgery.

METHODS

The Radial Artery Patency and Clinical Outcomes study is a randomized controlled trial comparing radial artery, saphenous vein, and free right internal thoracic artery. Of the 621 patients enrolled in the study, 465 patients received a graft to the right coronary artery or its branches. The retrospectively compiled database was used to establish patency rates and clinical events among these patients.

RESULTS

Absolute graft patency rates were as follows: radial artery, 86.9% of 68 (95% confidence interval, 76.6% to 93.1%); and saphenous vein, 81.2% of 197 (95% confidence interval, 75.1% to 86.1%). Noninferiority tests show that absolute radial patency to saphenous patency is at least 0.9526 (p = 0.025). Kaplan-Meier estimates of angiographic outcomes show no significant difference (log rank p = 0.22). Cardiac events in the right coronary territory occurred in the radial artery group (1.79%) versus the saphenous vein group (4.93%; p = 0.26). Overall mortality was 8.03% in the radial artery group versus 12.5% in the saphenous vein group (p = 0.23).

CONCLUSIONS

The radial artery patency is at least comparable to that of the saphenous vein when grafted to the right coronary artery or its branches. The paucity of clinical events in both grafts is notable. Selection of best conduit may therefore be made according to other factors.

Short- and midterm outcomes of coronary artery bypass surgery performed by surgeons in training

OBJECTIVE

The effect of training on outcomes in cardiac surgery is poorly studied. We aimed to study the results of coronary artery bypass grafting procedures performed by surgeons in training across our state with respect to short- and midterm postoperative outcomes.

METHODS

All coronary artery bypass grafting surgeries performed by trainee surgeons between July 2001 and December 2006 were compared with those performed by consultant surgeons using mandatory prospectively collected statewide data. Early mortality; prolonged ventilation or intensive care unit stay; return to operating theater for bleeding, stroke, myocardial infarction, or renal failure; and 5-year survival were compared using propensity score analysis.

RESULTS

A total of 7745 surgeries were included in this study. Trainees performed 983 (13%) surgeries. Trainee surgeries had longer perfusion and crossclamp times. Crude early postoperative outcomes were similar between trainee and consultant surgeries. After propensity score adjustment, early outcomes remained similar, with the exception of myocardial infarction (0.8% in trainee surgeries vs 0.4% in consultant surgeries, P = .046). Adjusted 1-, 3-, and 5-year survivals were similar between trainee and consultant surgeries: 95.3% versus 95.5%, 90.8% versus 92.0%, and 86.3% versus 87.1%, respectively.

CONCLUSION

Coronary artery bypass grafting performed by trainee surgeons within a supervised program is safe with acceptable short- and midterm outcomes.

Therapeutic hypothermia induced during cardiopulmonary resuscitation using large-volume, ice-cold intravenous fluid

INTRODUCTION

Therapeutic hypothermia after resuscitation improves outcome following prolonged out-of-hospital cardiac arrest. Laboratory studies suggest that this therapy may improve outcome further when induced during cardiopulmonary resuscitation. We report a case where therapeutic hypothermia was induced during cardiopulmonary resuscitation using large-volume (40 mL/kg), ice-cold (4 degrees C) intravenous fluid.

DESIGN

Case report.

SETTING

A tertiary level hospital in Victoria, Australia.

CASE REPORT

The patient suffered a cardiac arrest secondary to pericardial tamponade following right ventricular perforation during cardiac catheterisation. Percutaneous needle drainage was unsuccessful and open drainage via a left emergency thoracotomy was performed. Therapeutic hypothermia during cardiopulmonary resuscitation was induced using of a rapid infusion of large-volume (40 mL/kg), ice-cold (4 degrees C) crystalloid fluid. A spontaneous circulation was restored after 37 min of cardiac arrest. The patient made a satisfactory neurological recovery.

CONCLUSION

Treatment with a rapid intravenous infusion of large-volume (40 mL/kg), ice-cold (4 degrees C) fluid during cardiopulmonary resuscitation induces mild hypothermia and may provide neurological protection. Further clinical studies of this approach are warranted.

What factors influence the results of coronary artery bypass grafting in aged patients?

AIM

Early and late results were studied in order to improve the indication for coronary artery bypass grafting (CABG) and to enhance

RESULTS

METHODS

A total of 1 973 patients aged 70 years and older who had undergone isolated CABG were studied. Elective operations (EL) were performed in 1 716 patients and 257 patients underwent urgent or emergency operations (UR/EM). Patients were divided into two groups; 104 patients aged 80 years and older (Oct. Group) and 1 869 patients of septuagenarians (Sept. Group). There were no differences between the groups in the number of diseased vessels.

RESULTS

Total operative mortality rates in the Oct. and the Sept. groups were 7% and 4%, respectively. The operative mortality of elective surgery was 4% in both groups. The operative mortality of UR/EM CABG was significantly higher in the Oct. group than in the Sept. group (21% vs 6%). Operative mortality was significantly higher in patients with preoperative poor (<49%) left ventricular ejection fraction (LVEF) than in patients with higher (>50%) LVEF (6% vs 3%). Among preoperative risk factors, diabetes mellitus and peripheral vascular disease were significant contributory factors to operative death. In the follow-up study, 70% patients of the Oct. group and 72% patients of the Sept. group survived. Preoperative number of diseased vessels and number of CABG grafts did not influence the early and late

RESULTS

CONCLUSION

Preoperative poor LVEF, diabetes mellitus and peripheral vascular disease were significant contributory factors to operative death. When feasible, CABG in octogenarians should be performed electively.

Early and late results of combined mitral-aortic valve surgery

OBJECTIVE

This retrospective study was designed to assess the early morbidity and mortality as well as long-term mortality of combined aortic-mitral valve procedures at a single centre.

METHODS

Patients were identified by analysing the intensive care and perfusion databases, from 1989 to 2003, with 113 receiving aortic-mitral valve procedures. Eighty-four percent of patients received a mechanical bileaflet valve. Survival was assessed using a Kaplan-Meier method, and determinants of survival with the Cox proportional hazards model.

RESULTS

There were 57 men and 56 women, median age 59 (18-84) years. The 30-day mortality was 9% (n=10). This cohort contained a number of high risk patients, 38% were classified as New York Heart Association class IV, 33.5% had at least moderate ventricular impairment, 20% were redo procedures and 17% urgent procedures. Survival estimates at 5 and 10 years were 85% (0.76-0.90) and 65% (0.49-0.77), respectively. Multivariate pre-operative predictors of death included renal dysfunction (creatinine >200 micromol/L) and hypertension. Rheumatic aetiology was associated with improved survival.

CONCLUSION

This study shows acceptable short and long-term survival in patients undergoing combined aortic-mitral valve surgical procedures at a single centre. Renal impairment and hypertension were associated with a poorer long-term prognosis and rheumatic aetiology was associated with improved survival. Age, LVEF and NYHA class were not associated with a worse outcome. This may affect future decision making in light of an aging population.

Cardiac surgery in octogenarians

BACKGROUND

Early and late results were studied in order to improve the indications for surgery in the elderly.

METHODS

Two hundred and thirty-seven patients aged 80 years or older underwent cardiac surgery between 1987 and 2001. The mean age of patients, which included 148 men and 89 women, was 82 years. Elective operations were performed in 194 patients and urgent or emergency operations in 43. Coronary artery bypass grafting (CABG) was performed in 104 patients, valve surgery in 60, CABG plus valve in 58, and other surgery in 15. Late results were obtained in 91% of patients, and the mean follow-up period was 54 months.

RESULTS

Operative mortality was 9% in total; 7% in CABG, 5% in valve, 10% in CABG plus valve. Operative mortality was significantly higher in the urgent/emergency group than in the elective group (25% vs 6%). The actuarial survival rate for hospital survivors at 60 months after surgery was 75% and the mean survival period 76 months. There were no significant differences among operations. Preoperatively 81% of the patients had been in New York Heart Association class III or IV, and 88% of survivors were in class I or II in the late period.

CONCLUSIONS

Early and late results for elective surgery in octogenarians are satisfactory. However, for urgent or emergent cases, there is a marked increase in morbidity and mortality.

The mid-term outcome of geometric endoventricular repair for the patients with ischemic left ventricular dysfunction

OBJECTIVE

Recent studies have suggested that increased left ventricular (LV) size is a risk factor for perioperative mortality in patients with low ejection fraction (EF) undergoing coronary artery bypass surgery (CABG). We previously presented a new method of LV reconstruction, called geometric endoventricular repair (GER) as representing a physiologically effective repair. The aim of this study is to assess whether GER confers benefits compared to patients undergoing CABG alone.

METHODS

Between July 1996 and July 2001, 110 patients with a low EF of less than 35% documented by radionuclide ventriculogram (RNVG) underwent CABG in Austin Hospital, Australia, and were divided into two groups. Group I consisted of 52 patients undergoing isolated CABG. Group II comprised 58 patients undergoing CABG and GER. We compared the two groups in terms of EF, NYHA class, incidence of recurrent heart failure, and mortality.

RESULTS

Preoperative EF was 27.7+/-6.1% in group I and 27.4+/-5.7% in group II, respectively (NS), with significant improvement in both groups (33.8+/-13.0% in group I, 35.1+/-13.3% in group II). NYHA class was also significantly improved postoperatively (from 3.3 to 1.8 in group I, and 3.6 to 1.7 in group II). There were 15 patients (28.8%) hospitalized for heart failure in group I, postoperatively, compared to seven patients (10.9%) in group II (p=0.026). Cardiac event-free survival rate at 28 months (mean follow-up) was also significantly higher in group II (88.9% in group II vs. 70.6% in group I, p=0.05). The actuarial survival rate at 31 months (mean follow-up) was 88.2% in group I and 95.3% in group II, respectively (NS).

CONCLUSIONS

LV reconstruction along with CABG for ischemic ventricular dysfunction may provide symptomatic and cardiac event free survival benefits, compared to CABG alone.

On-pump coronary artery surgery versus off-pump exclusive arterial coronary grafting: a matched cohort comparison

BACKGROUND

It is unknown whether coronary artery bypass grafting without cardiopulmonary bypass and with exclusive use of arterial grafts (arterial off-pump CABG) offers any significant short-term advantages over standard CABG with cardiopulmonary bypass. Accordingly, we performed a comparison of the short-term outcomes of arterial off-pump and standard CABG patients matched for preoperative risk and number of grafts.

METHODS

We studied 90 consecutive arterial off-pump CABG patients during a 2-year period, obtained demographic and clinical features and surgical characteristics, and calculated their predicted surgical risk (EuroSCORE). Using a database of 750 contemporaneous patients treated with standard CABG, we created a matched cohort of 90 patients using an iterative process prioritizing number of grafts, target vessels, EuroSCORE, age, and sex. We compared the two groups for baseline features and short-term clinical outcomes.

RESULTS

There were no differences in age (65.9 versus 64.7 years), sex, EuroSCORE (3.3 versus 3. 6), number of grafts (2.1 versus 2.1), and preoperative left ventricular function. Arterial off-pump CABG, however, was associated with decreased duration of operation (213 versus 252 minutes; p < 0.0013), decreased peak postoperative troponin I levels (mean, 10.8 versus 29.1 ng/mL; p < 0.0001), decreased peak norepinephrine dose (2.3 versus 4.1 microg/ min; p < 0.0082), and decreased likelihood of receiving red blood cell transfusion (17.8% versus 40%; p = 0.0016). There were no differences in duration of intensive care unit or hospital stay, incidence of atrial fibrillation, or other clinical complications. There was one death in each group.

CONCLUSIONS

After matching for number of grafts and other important preoperative risk markers, arterial off-pump CABG still decreases the need for red blood cell transfusion and offers other moderate clinical advantages compared with standard on-pump CABG.

Radial artery 2000--risk analysis of mortality for coronary bypass surgery with radial artery

BACKGROUND

The aim of this study is to review our experience with using more than 2,000 RAs over the last seven years, and to assess the medium-term outcome in terms of morbidity and mortality.

METHODS

Between June 1994 and June 2001, a total of 2,024 RAs have been used in 1,613 patients. The mean duration of follow-up was 40.1 months and ranged from one to 88 months. We assessed the results of postoperative mortality and morbidity, RA graft patency, coronary event free rate, and actuarial survival rate. Specifically, the independent predictors of early and late mortalities were examined.

RESULTS

Perioperative myocardial infarction was indicated in 0.8%, stroke in 1.6%, respectively. Overall hospital mortality was 35 patients (2.4%). RA patency rate was 98.1%. Coronary event free rate and actuarial survival rates at seven years were 99.6% and 95.1%, respectively. Multivariate logistic regression analysis detected an ejection fraction of less than 30% (p=0.0009), re-exploration (p=0.02), and stroke (p=0.03) as significant independent predictors of operative mortality. The use of saphenous vein graft (p=0.0417) and renal impairment (p=0.0045) were significant independent predictors of late mortality.

CONCLUSIONS

Our seven-year experience of CABG with RA suggested that the use of RA was safe and had excellent results in postoperative graft patency and low incidence of complications. This study suggested that the use of RA instead of the saphenous vein graft made a better outcome for late survival in the patients undergoing CABG.

Upper extremity deep vein thrombosis after radial artery harvesting

A 47-year-old diabetic man with unstable angina underwent coronary bypass surgery using bilateral radial arteries and left internal thoracic artery. After surgery, the patient suffered from severe right arm pain and swelling without any bleeding. The postoperative immediate digital subtraction angiogram detected thrombotic occlusion of the right axillary vein. We report here a rare case of deep vein thombosis related to radial artery harvesting.

Post harvest wound infection and patient's perception: comparative study between radial artery and saphenous vein harvest sites

INTRODUCTION

Despite renewed clinical interest in radial artery grafts (RA) for coronary artery bypass grafting, there is a paucity of controlled prospective data on its efficacy. We report on the rate of harvest related complications from a randomized radial artery study.

METHODS

Two hundred eighty nine patients were divided into two groups. Group 1 received RA grafts (n=154 patients) and Group 2 (n=135 patients) received saphenous vein grafts (SVG). Postoperative wound problems were assessed using a questionnaire. Postoperative harvest site infections were also carefully documented.

RESULTS

In group 1, 6 of 154 (3.9%) patients had harvest site wound infections. Five of them improved by antibiotic therapy alone. In group 2, 24 of 135 (17.8%) patients had harvest site wound infections (p=0.001 vs. group 1). Fifteen of these patients needed redressing due to discharge from the wound. One hundred forty-nine patients (96.7%) in group 1 answered that their hand function was normal on the questionnaire. Concerns and discomfort about the arm scars in the group 1 were of a similar value of 5.2% (8/154), respectively. In group 2, the incidence of those about the leg were 7.4% (10/135) and 11.9% (16/135), respectively. Although there was no significant difference in concerns about the scar, discomfort was significantly higher in group 2 compared with group 1 (p=0.0139).

CONCLUSIONS

RA harvest is associated with fewer wound infections and scar discomfort than SVG harvest. Radial artery harvest is almost acceptable in terms of a patient's perception. However, there are still patients who have some symptoms in the forearm after RA harvest. Long-term follow-up is necessary for patient's hand function.

An extracorporeal membrane oxygenation-based approach to cardiogenic shock in an older population

BACKGROUND

We investigated the efficacy of an integrated system of advanced supportive care based on extracorporeal membrane oxygenation (ECMO) in older patients with an estimated mortality of more than 90% to establish whether its use is justifiable.

METHODS

Treatment was provided by cardiac surgeons and critical care physicians and included the following key elements: (1) ECMO, (2) early application of continuous venovenous hemofiltration, (3) inhaled nitric oxide, (4) maintenance of perfusion pressure with norepinephrine, (5) maintenance of pulmonary blood flow by ventricular filling with intravenous colloids, (6) avoidance of early postoperative anticoagulation, (7) frequent use of transesophageal echocardiography, and (8) low tidal volume ventilation. Demographic features, intraoperative details, postoperative course, ECMO weaning rate, morbidity, survival to hospital discharge, and the quality of life of survivors were recorded.

RESULTS

Seventeen consecutive patients (median age, 69 years) with refractory cardiogenic shock were studied. The median duration of ECMO was 86 hours (20 to 201 hours). Eleven patients (65%) were successfully weaned from ECMO. Seven patients (41%) survived to discharge. The major causes of morbidity were bleeding and leg ischemia. All patients who survived to discharge were alive and well at follow-up (median, 21 months) and reported a satisfactory quality of life.

CONCLUSIONS

An ECMO-based approach can be used with acceptable results in the treatment of refractory cardiogenic shock, even in older patients.

Early and intensive continuous hemofiltration for severe renal failure after cardiac surgery

BACKGROUND

The aim of this study was to test whether early and intensive use of continuous venovenous hemofiltration (CVVH) achieved a better than predicted outcome in patients with severe acute renal failure undergoing cardiac operations, and whether a simple and yet accurate model could be developed to predict their outcome before starting CVVH.

METHODS

Medical record analysis with collection of demographic, clinical, and outcome information was used.

RESULTS

Sixty-five consecutive patients were treated with early and intensive CVVH (mean operation to CVVH time, 2.38 days; pump-controlled ultrafiltration rate, 2 L/h) after coronary artery bypass grafting (56.9%), single valve procedure (16.9%), or combined operations (26.2%). In 32.3% of patients, intraaortic balloon counterpulsation was required and 20% of patients were emergencies. Sustained hypotension despite inotropic and vasopressor support occurred in 40% of patients and prolonged mechanical ventilation in 58.5%. Using an outcome prediction score specific for acute renal failure, the predicted risk of death was 66%. Actual mortality was 40% (p = 0.003). Using multivariate logistic regression analysis and neural network analysis, patient outcome could be predicted with good levels of accuracy (receiver operating characteristic 0.89 and 0.9, respectively).

CONCLUSIONS

Early and aggressive CVVH is associated with better than predicted survival in severe acute renal failure after cardiac operations. Using readily available clinical data, the outcome of such patients can be predicted before the implementation of CVVH.

The right internal thoracic artery graft--benefits of grafting the left coronary system and native vessels with a high grade stenosis

OBJECTIVE

The left internal thoracic artery (LITA), when grafted to the left anterior descending artery (LAD), is generally accepted as the conduit of choice for coronary artery bypass grafting (CABG). In contrast, the role and efficacy of the right internal thoracic artery (RITA), despite its long-term use as a coronary artery graft, is relatively less understood. Accordingly, in this study, we sought to assess the utility of the RITA as a coronary conduit by examining the long-term patency of both in situ and free RITA grafts and analyzing the association between intraoperative graft and coronary artery variables.

METHODS

Nine hundred and sixty-two patients (LITA 962, RITA 432) who had CABG between 1985 and 1998 and underwent re-angiography for evidence of myocardial ischemia were included in this observational analysis. The diameter of the internal thoracic artery (ITA), the presence of a proximal anastomosis with the aorta, the location of the anastomosis with the coronary artery, and the coronary artery diameter, were recorded at the initial procedure. The follow-up was 67.0+/-39.4 months (mean+/-SD, range 0.1-169.5). The relationship between intraoperative variables and graft patency was assessed using Cox proportional hazard models.

RESULTS

Highest RITA failure rates were associated with grafting a native coronary artery with a stenosis of less than 60% compared with 80-100% (RR 3. 8 (95% CI, 1.9-7.2) P=0.0001). Grafts to non-LAD arteries had a higher risk of failure, the highest risk ratio being associated with grafting the right coronary artery (RR 4.0 (95% CI, 0.9-17.4) P=0.06)). Free compared with in situ grafts were also associated with a higher risk of failure with this result bordering on statistical significance (RR 1.9 (95% CI, 1.0-6.0) P=0.06))

CONCLUSION

Preference should be given to grafting arteries with a high grade stenosis or occlusion, to grafting left rather than right coronary arteries, and to using in situ rather than free ITA grafts. Passing the RITA to the left, either anterior to the aorta or through the transverse sinus, did not influence patency.

Extracorporeal membrane oxygenation in pregnancy

We describe the use of extracorporeal membrane oxygenation in pregnancy. There were no major complications, and the outcome was successful for mother and baby.

Management of a patient with a complete rupture of a main bronchus in a community hospital

We describe the successful use of a portable extracorporeal membrane oxygenation machine for a patient with complete rupture of the left main bronchus after a road crash. The machine was used before and during left main bronchus reanastomosis at a community hospital 30 km from Melbourne, and then during acute interhospital transfer.

Pattern and significance of cerebral microemboli during coronary artery bypass grafting

BACKGROUND

Strokes that occur during coronary artery bypass grafting are often caused by embolism. Intraoperative transcranial Doppler monitoring can detect cerebral microemboli. The aims of this study were to identify the pattern of microembolic phenomena during various stages of coronary artery bypass grafting, to verify whether numbers of high-intensity transient signals correlated with early neuropsychologic deficits, and to identify, using magnetic resonance imaging scans, whether radiologic evidence of cerebral infarction correlated with microembolic numbers during the bypass period.

METHODS

Forty-one consecutive patients undergoing coronary bypass grafting with transcranial Doppler monitoring were enrolled in this study. All had preoperative and postoperative magnetic resonance imaging brain scans. A subgroup of 32 patients were studied by comparing microembolic load and early neuropsychological outcomes.

RESULTS

Transcranial Doppler monitoring confirmed that most microemboli occurred during cardiopulmonary bypass. A significant early neuropsychological deficit after coronary artery bypass grafting did correspond to the total microembolic load during bypass (p = 0.008). However, patients with cerebral infarction on magnetic resonance imaging had significantly more microembolic signal during the preincision phases and not during the bypass period.

CONCLUSIONS

Microembolic load during bypass is associated with early neuropsychologic deficits. In contrast, patients who show evidence of strokes during coronary artery bypass grafting have a higher microembolic load during the preincision phase than those without cerebral infarction. Differing mechanisms may be responsible for these different outcomes.

The intraoperative assessment of ascending aortic atheroma: epiaortic imaging is superior to both transesophageal echocardiography and direct palpation

OBJECTIVES

To determine the optimal method for detecting ascending aortic atheroma intraoperatively by comparing manual palpation by the operating surgeon, intraoperative transesophageal echocardiography, and epiaortic ultrasound (linear and phased-array imaging); and to assess risk factors for severe aortic atheroma.

DESIGN

A longitudinal prospective study. Assessment of the atheroma by manual palpation was blinded to the results of the ultrasound images.

SETTING

The study was performed in a single university tertiary referral hospital.

PARTICIPANTS

One hundred consecutive patients undergoing coronary bypass or valve surgery were studied after their written, informed consent.

INTERVENTIONS

Potential risk factors were evaluated by both a patient questionnaire and examination of prior hospital records. The ascending aorta was assessed by the following methods: manual palpation by the operating surgeon, intraoperative transesophageal echocardiography, and epiaortic ultrasound (linear and phased-array imaging) performed by an echocardiologist. For analysis, the ascending aorta was divided into three equal segments: proximal, mid, and distal, corresponding to regions of different operative manipulations.

MEASUREMENTS AND MAIN RESULTS

Age older than 70 years and hypertension were significant risk factors for severe ascending aortic atheroma with adjusted odds ratios of 3.3 (95% CI, 1.2 to 9.3) and 3.9 (95% CI, 1.3 to 12.0), respectively. There was no significant difference in atheroma detection between the two ultrasonic epiaortic probes in any segment; however, epiaortic probes were superior to manual palpation in all segments and also superior to transesophageal echocardiography in the mid and distal segments of the ascending aorta.

CONCLUSIONS

Age older than 70 years and hypertension are significant risk factors for severe ascending aortic atheroma. Intraoperative detection of ascending aortic atheroma is best achieved by epiaortic ultrasound with either a linear or phased array transducer. Transesophageal echocardiography is an insensitive technique for evaluation of mid and distal ascending aortic atheroma and, therefore, of little value in guiding surgical manipulations such as cross-clamping.

Prediction of outcome after revascularization in patients with poor left ventricular function

BACKGROUND

In patients with poor left ventricular function, the determinants of outcome after revascularization are unknown.

METHODS

We studied prospectively 57 patients with stable coronary artery disease and poor left ventricular function (left ventricular ejection fraction, 0.28 +/- 0.04) who underwent coronary artery bypass grafting. Clinical variables were assessed as predictors of outcome in all patients, and preoperative stress thallium-201 scintigraphic data were analysed in 37 patients.

RESULTS

The operative mortality was 1.7%. At 12 months after operation, 46 of the 49 survivors were angina-free and 35 had fewer heart failure symptoms, but postoperative left ventricular ejection fraction (0.30 +/- 0.09) did not change significantly. Eighteen survivors had left ventricular ejection fraction improved by 0.05 or more (0.30 +/- 0.03 preoperatively, 0.40 +/- 0.05 postoperatively; p = 0.0001). The adjusted odds ratio of large reversible thallium-201 defects in predicting such outcome was 15 (95% confidence interval, 1.6 to 140), whereas other clinical variables had no predictive value. The transplantation-free 5-year survival was 73%.

CONCLUSIONS

In patients with poor left ventricular function, surgical revascularization can be performed safely, with good symptomatic relief and long-term survival. One-year survival and improvement in left ventricular function is better in patients with large reversible defects on preoperative stress thallium-201 scintigraphy.

Concomitant coronary revascularization and resection of lung cancer

As age and smoking are common risk factors, patients with lung cancer frequently have coexistent ischaemic heart disease. Ignoring the coronary disease results in an unacceptable operative mortality, whilst sequential coronary grafting and lung resection may prejudice the results of the resection. A series of 10 patients underwent combined coronary revascularization (average 2.9 grafts per patient) and lung resection for carcinoma (seven lobectomies, one bilobectomy, one sleeve lobectomy, and one pneumonectomy). The majority of patients had unstable angina, triple vessel or left main coronary artery stenosis and poorly staged tumours. There was no operative mortality and the average hospital stay was 20 days. Half the patients had significant peri-operative morbidity; seven are alive and well at between 12 and 38 months follow-up; but three have died of recurrent carcinoma (one with associated sepsis) at 3, 8, and 13 months. Combined coronary revascularization and lung resection can be safely performed in selected patients. The early morbidity is mainly related to the cardiac procedure and impaired respiratory function preoperatively, but the long-term results are dependent upon the control of the lung carcinoma.

Amiodarone versus bretylium for suppression of reperfusion arrhythmias in dogs

Reperfusion arrhythmias are an important complication of interventions to limit infarct size. Recently, amiodarone has been shown to be rapidly effective in suppressing sustained, incessant ventricular tachycardia and ventricular fibrillation in this setting. This study evaluated the time course of arrhythmia suppression and comparative efficacy of amiodarone versus bretylium in a canine model of reperfusion arrhythmias. Of 23 dogs subjected to a Harris two-stage coronary artery ligation followed by release, 18 demonstrated clinically significant ventricular arrhythmias and received either intravenous amiodarone, 5 mg/kg (9 dogs), or intravenous bretylium, 5 mg/kg (9 dogs). Direct-current shocks for sustained ventricular tachycardia or ventricular fibrillation were administered as necessary. Amiodarone rapidly suppressed sustained ventricular tachycardia and ventricular fibrillation in this model with no dog in the amiodarone-treated group requiring cardioversion after completion of the 15-minute infusion versus 4 of 9 dogs in the bretylium-treated group (p less than 0.05). Amiodarone was more effective than bretylium in suppressing episodes of sustained ventricular tachycardia/ventricular fibrillation, episodes of nonsustained ventricular tachycardia, and premature ventricular complexes. The blood pressure and heart rate decreased more after amiodarone administration than after bretylium administration. We conclude that, in the canine reperfusion arrhythmia model, amiodarone is rapidly effective in suppressing ventricular arrhythmias and is more effective than bretylium.

The use of parenteral nutrition in the management of external gastrointestinal tract fistulae

Malnutrition is common in patients with gastrointestinal tract fistula, and is an important cause of the high mortality seen with this surgical complication. A prospective review of three years' experience in the management of fistulae with parenteral nutrition was undertaken, and the results obtained were compared with those in a group of patients treated prior to the introduction of this form of therapy. The use of parenteral nutrition resulted in a reduction of the mortality from 63% to 23% in unselected cases. The mortality was zero where parenteral nutrition was used in patients under 65 years of age with non-malignant disease. With parenteral nutrition therapy, the fistulae in almost all cases closed spontaneously, in contrast with a high proportion requiring operation (20 in 38 cases) where parenteral nutrition was not used. It is concluded that all patients with significant gastrointestinal fistula should be given appropriate parenteral nutrition as their prime mode of therapy.