Off-pump right atrial surgery: Vena caval inflow occlusion in cardiac lesions.

BACKGROUND: Vena caval inflow occlusion, despite its utility in pediatrics, is rarely used in adults. We report the use of inflow occlusion in adults when cardiopulmonary bypass is contraindicated. METHODS: Between January 1999 and July 2014, 35 patients in 3 hospitals presented with right-sided cardiac lesions; 27 had right-sided endocarditis with sepsis despite maximal medical therapy, the rest had organized sterile masses with embolic potential in the right side of the heart. Comorbidities included immunosuppression, malignancy, and dialysis-dependent renal failure. Twelve patients had heparin-induced thrombocytopenia. Using inflow occlusion on a beating heart, tricuspid valve vegetectomy was performed in 23 patients, vegetectomy and tricuspid valve repair in 3, removal of infected pacing leads in 7, and removal of a migrated inferior vena cava filter in 1. Eight patients had a single 2-min period of vena caval inflow occlusion, and 25 had additional periods of vena caval inflow occlusion after periods of reperfusion. The first 23 procedures were performed through a sternotomy. Nine patients underwent a right minithoracotomy (redo in 2). RESULTS: There were no deaths. Infected patients had resolution of sepsis and improvement in respiratory status. Three patients had moderate tricuspid regurgitation, the rest had trivial to mild tricuspid regurgitation. One patient had a transient neurological deficit postoperatively, and one had late empyema. CONCLUSION: Removal of infective material, sterile masses, and retained foreign bodies can safely be performed under vena caval inflow occlusion when cardiopulmonary bypass is contraindicated.

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.

Patency of the radial artery graft: angiographic study in 209 symptomatic patients operated between 1995 and 2002 and review of the current literature.

OBJECTIVES: The purpose of this study is to define the long-term patency of the radial artery (RA) graft and review the current literature. METHODS: Two hundred and eighty-six RA symptom-directed graft angiograms were studied in 209 patients. The preoperative patient characteristics and intraoperative variables were collected prospectively from patients who had primary coronary artery bypass grafting between 1995 and 2002. A total of 166 (79%) patients were male with a mean age of 65 years. The mean period from operation to re-angiogram was 35 months. Actuarial techniques are not valid in graft patency studies as the time when the graft occluded is not known. Therefore, RA patency was analyzed at four categorical time intervals. The RA was grafted to the left anterior descending artery (LAD) in six patients (2%), diagonal (DIAG) in 29 (10%), obtuse marginal (OM) in 166 (58%), right coronary artery (RCA) in 9 (3%) and posterior descending artery (PDA) in 76 (27%) cases. The graft failure was defined as >or=80% stenosis. RESULTS: A total of 259 (91%) grafts were patent and 26 (9%) had failed. Most grafts were widely patent or occluded. The LAD/DIAG patency was 30/35 (86%), OM patency 154/166 (93%) and RCA/PDA patency 79/84 (94%). The interval from surgery to angiogram did not affect the RA graft patency (86% at <1 year, 95% at 1-3 years, 89% at 4-5 years, 96% at >5 years). CONCLUSIONS: Even in a patient cohort with adverse symptoms, excellent RA patency was achieved that remained almost constant through all time intervals studied. Better selection, harvesting and preservation may further improve early patency.

Survival after myocardial revascularization for ischemic cardiomyopathy: a prospective ten-year follow-up study.

OBJECTIVE: The aim was to prospectively analyze all-cause mortality, predictors of survival, and late functional results after myocardial revascularization for ischemic cardiomyopathy over a 10-year follow-up. METHODS: We prospectively studied 57 patients with stable coronary artery disease and poor left ventricular ejection function (<35%), enrolled between 1989 and 1994. Stress thallium was analyzed in 37 patients to identify reversible ischemia. To avoid patients with a stunned myocardium, we excluded those with unstable angina or myocardial infarction within the previous 4 weeks. Mean age of the patients was 67 +/- 8 years, and 93% of patients were men. Mean left ventricular ejection fraction was 0.28 +/- 0.04, 50% were in Canadian Cardiovascular Society angina class III-IV, and 65% were in New York Heart Association functional class III-IV. RESULTS: Operative mortality was 1.7% (1/57). The mean left ventricular ejection fraction (0.30) at 15 months postoperatively did not change from before operation (0.28, P =.09). There were 8 deaths at 1 year and 42 deaths over the course of the study, producing a survival of 82.5% at 1 year, 55.7% at 5 years, and 23.9% at 10 years (95% confidence interval: 14.6%-39.1%). Symptom-free survival was 77.2% at 1 year and 20.3% at 10 years. The leading cause of death was heart failure in 29% (12/42). Multivariate analysis showed that large reversible defects on stress thallium were associated with improved left ventricular ejection fraction at 1 year (P =.01) but only male sex was associated with improved long-term survival (P =.036). CONCLUSIONS: Myocardial revascularization for ischemic cardiomyopathy is associated with good functional relief from the symptoms of angina initially and, to a lesser extent, heart failure. Revascularization may have the advantage of preserving the remaining left ventricular function. However, the long-term mortality remains high.

Factors affecting saphenous vein graft patency: clinical and angiographic study in 1402 symptomatic patients operated on between 1977 and 1999.

BACKGROUND: The purpose of this study was to find the preoperative and intraoperative factors that affect vein graft patency. METHODS: A total of 3715 graft angiograms in 1607 patients were studied for recurrence of angina. The preoperative patient characteristics and intraoperative variables were prospectively collected from patients who had primary coronary artery bypass grafting during the period from 1977 to 1999. A total of 1339 (83%) patients were male, with a mean age of 59 years. The mean period from operation to reangiogram was 99 months. The saphenous vein was grafted to the left anterior descending artery in 557 (15%), to the diagonal artery in 669 (18%), to the obtuse marginal artery in 1300 (35%), to the right coronary artery in 409 (11%), and to the posterior descending artery in 780 (21%) cases. Graft failure was defined as >or=80% stenosis. RESULTS: During the course of the study, 2266 (61%) grafts were patent, and 1449 (39%) had failed. The patient variables that significantly reduced graft patency were a younger age (P <.001) and an ejection fraction <30% (P =.047). Operative variables associated with reduced graft patency were small coronary artery diameter (P <.001), large conduit diameter (P =.001), and the coronary artery grafted (lowest patency in the right coronary artery and maximum patency in the left anterior descending artery territory; P =.002). The interval from operation to repeat angiogram (P <.001, with 78% patent at 1 year, 78% at 5 years, 60% at 10 years, and 50% at 15 years) and the year in which the operation was performed (more recent operations had better patency; P <.001) significantly affected graft patency. CONCLUSIONS: Saphenous vein graft patency improved over the course of the study. The best results were obtained in older patients with good left ventricular function. Large-caliber arteries on the left system, when grafted with a small-diameter vein, were associated with the best outcome.

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.

Ventricular constraint in severe heart failure halts decline in cardiovascular function associated with experimental dilated cardiomyopathy.

BACKGROUND: We have shown that passive ventricular constraint during moderate heart failure can halt progressive deterioration in cardiac function in an experimental model of ovine pacing induced heart failure (HF). We report on ventricular constraint in severe heart failure. METHODS: Eighteen adult merino sheep were used. Severe heart failure was induced in two stages, ie, high rate ventricular pacing for 21 days to produce moderate HF and then for 42 days to induce severe HF. A custom-made polyester mesh cardiac support device ([CSD] Acorn Cardiovascular, St Paul, MN) was implanted snugly around both ventricles through a lower partial sternotomy in 9 sheep (group 1). Rapid ventricular pacing was continued for a further 28 days in all animals to induce advanced HF. Cardiovascular functional indicators were determined using echocardiography and a submaximal treadmill exercise protocol at base line, moderate, severe, and advanced stages. The 9 sheep in group 2 were used as controls. RESULTS: Cardiovascular function was significantly depressed in all animals in advanced heart failure compared with base line, with left ventricular ejection fraction (LVEF) falling from 50% to 25% (p < 0.05) and LV +dp/dt((max)) declining from 1,777 to 1,243 (p < 0.05). However after CSD implantation cardiovascular function during exercise improved significantly despite ongoing rapid pacing, with LVEF increasing to 30% and LV +dp/dt to 1,499 (p < 0.05) in group 1. There were no significant changes in left ventricular long axis area (157 to 151 cm(2)) and short axis (6.8 to 6.1 cm) dimensions at the termination of pacing compared with those at time of CSD implant. Mitral regurgitation improved slightly from 2.5 to 2.19 after containment (p < 0.05) in group 1 but increased to 2.83 in group 2. CONCLUSIONS: Ventricular constraint in advanced heart failure with a custom-made polyester mesh device halted the decline in cardiac function seen in untreated animals with this pacing-induced animal model of heart failure. These results indicate potential clinical implications for ventricular containment in the treatment of end-stage heart failure.

Radial artery patency and clinical outcomes: five-year interim results of a randomized trial.

OBJECTIVE: This study was undertaken to compare elective angiographic patency and cardiac event-free survival of the radial artery graft with that of the free right internal thoracic artery or saphenous vein during a 10-year period after primary coronary artery bypass surgery. METHODS: This prospective, randomized, single-center trial was conducted on two groups of patients undergoing primary coronary artery bypass surgery. In a younger group (group 1, n = 285, <70 years), the radial artery was compared with the free right internal thoracic artery. In an older group (group 2, n = 153, >/=70 years), the radial artery was compared with the saphenous vein. The trial conduit was grafted to the largest available coronary artery other than the left anterior descending coronary artery. Angiography was scheduled at intervals between 0 and 10 years according to a second random assignment. Patients were followed up at yearly intervals to assess clinical outcomes. Clinical outcomes were analyzed on an intent-to-treat basis during the 10-year follow-up with time-related analyses. This interim study reports angiographic and clinical outcome results during the first 5 years. RESULTS: Graft patency estimates were as follows: 0.95 (95% confidence interval 0.85-0.99) in 39 radial arteries versus 1.0 in 29 right internal thoracic arteries (P =.4) in group 1, and 0.86 (95% confidence interval 0.67-0.99) in 24 radial arteries versus 0.95 (95% confidence interval 0.83-0.99) in 22 saphenous veins (P =.5) in group 2. Cardiac event-free survival estimates were as follows: 0.91 (95% confidence interval 0.76-0.99) for the radial artery versus 0.82 (95% confidence interval 0.63-0.99) for the right internal thoracic artery (P =.7) in group 1, and 0.84 (95% confidence interval 0.64-0.99) for the radial artery versus 0.89 (95% confidence interval 0.72-0.99) for the saphenous vein (P =.9) in group 2. CONCLUSION: The 5-year interim results do not support the hypothesis that the radial artery has superior patency to or is associated with fewer clinical events than free right internal thoracic artery or saphenous vein grafts.

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.

Epicardial radiofrequency ablation of both atria in the treatment of atrial fibrillation: experience in patients.

BACKGROUND: Despite success with the Maze procedure and its modifications in treating atrial fibrillation, longer procedure times and increased morbidity have precluded widespread use. The operative treatment for atrial fibrillation associated with aortic valve disease and ischemic heart diseases have not been established. We report the early results of epicardial radiofrequency coagulation on both atria and discuss the availability of this procedure. METHODS: The Australasian database of radiofrequency ablation lists 130 patients with established or frequent intermittent atrial fibrillation that underwent various cardiac surgical procedures between March 2000 and March 2002. Forty patients without mitral valve disease underwent epicardial radiofrequency coagulation on both atria. Twenty-eight patients were in established chronic atrial fibrillation, 9 in paroxysmal atrial fibrillation, and 3 patients had atrial flutter. The primary surgical procedures were coronary artery bypass grafting in 19 patients, aortic valve replacement in 9, coronary artery bypass grafting plus aortic valve replacement in 8, and other procedures in 4 patients. RESULTS: The procedure increased the cross-clamp time by a mean of 10 minutes. Three patients required defibrillation postoperatively, within the first 3 months and have since stayed in sinus rhythm. One patient had late atrial flutter that was cardioverted to sinus rhythm. Sinus recovery rate was 93.7% (15 of 16 patients) at 6 months and 100% in 8 patients reviewed at 12 months. Atrial contractility was maintained. CONCLUSIONS: Epicardial radiofrequency coagulation may be a very effective way of converting patients with atrial fibrillation into sinus rhythm.

Severe ischemic early liver injury after cardiac surgery.

BACKGROUND: The epidemiology, pathogenesis and prognosis of severe ischemic early liver injury (SIELI) after cardiac surgery are poorly understood. Accordingly, we studied patients whose alanine transaminase (ALT) concentration acutely increased above 500 IU/l in the immediate postoperative period and compared these patients to two control groups matched for preoperative and immediate postoperative characteristics. METHODS: We used a prospective database of 1,800 consecutive cardiac surgical cases to identify the study groups. Group I was made up of 20 patients with ALT levels above 500 IU/L in the acute postoperative stage (SIELI). Preoperative liver tests were normal in all these patients. Group II was obtained by identifying 20 control cases whose age, type of surgery, NYHA classification, and Parsonnet score matched Group I (preoperative controls). Group III was obtained by identifying 20 patients who developed postoperative acute renal failure and shock (ARF/shock; postoperative controls) but no enzyme evidence of hepatic injury. RESULTS: Acute renal failure, a low cardiac index (CI) state, and mortality were more common in SIELI and ARF/Shock patients compared with preoperative controls (all p values less than 0.01). Peak postoperative pulmonary artery occlusion (PAOP) and central venous (CVP) pressures were also higher in SIELI and ARF/Shock patients than controls (all p values less than 0.02). A higher dose of norepinephrine and milrinone were required to maintain blood pressure and cardiac output in SIELI and ARF/shock patients than preoperative controls (all p values less than 0.005). SIELI patients, however, differed from ARF/Shock patients in that they had a higher preoperative NYHA class and a greater incidence of hypertension and diabetes. Stepwise linear regression analysis identified a postoperative low CI and the presence of diabetes as the only predictors of peak ALT value (p less than 0.05). Multivariate logistic regression analysis identified female gender as being associated with a higher likelihood of SIELI (odds ratio: 6.13; 95% CI 1.08 to 34.82) CONCLUSIONS: SIELI after cardiac surgery carries a high mortality and is strongly associated with a low cardiac output and increased filling pressures, suggesting that liver ischemia induced by a combination of decreased perfusion and congestion is fundamental to its pathogenesis. A history of cardiac failure, diabetes, hypertension, and female gender may represent risk factors for its development and severity in the setting of a postoperative low cardiac output state.

What can Doppler wave forms of the left internal thoracic artery teach us? -The efficacy of apical transthoracic approach of Doppler echocardiography-.

The Doppler wave form along the proximal left internal thoracic artery (LITA), which is detected by the parasternal or suplaclavicular view, shows a different pattern from that of the distal side of the LITA due to the effect of blood pulsatility from the subclavian artery. We evaluated postoperative LITA function immediately after surgery with an apical approach of transthoracic pulsed Doppler echocardiography in 124 patients and compared its results with that of one month postoperative Doppler findings and graft angiogram. The LITA was effectively detected and good quality Doppler waveforms obtained in 120 (96.8%) patients. The LITA diameter was significantly enlarged in the first month after surgery compared with that of the postoperative early phase (1.99 0.31 vs. 1.71 0.72 mm, p<0.05). The diastolic peak velocity and diastolic/systolic velocity ratio (D/S) in the postoperative early phase were 0.26 0.08 m/sec. and 1.54 0.04, respectively. These results were unchanged one month postoperatively. In graft angiography, all LITAs were patent, but three types of abnormal findings around the anastomosis such as string sign, anastomotic stenosis, and distal native coronary stenosis were indicated in 6 (5.5%) patients. The Doppler study in these patients showed decreasing diastolic peak velocity and D/S of less than 1.0. LITA Doppler wave with D/S of more than 1.0 was associated with a good angiographic finding. This technique was considered not only noninvasive but also noninfective method for postoperative early graft assessment.

An ovine model of tachycardia-induced degenerative dilated cardiomyopathy and heart failure with prolonged onset.

BACKGROUND: The aim of this study was to develop a model of long-term progressive heart failure (HF). METHODS AND RESULTS: A cardiac output flowprobe was implanted on the pulmonary artery of 9 adult sheep weighing 40 to 50 kg. Rapid ventricular pacing for 21 days at 160 to 190 bpm (rate A) resulted in moderate HF. Animals were then paced at 205 to 215 bpm (rate B) for 42 days (severe HF) and for 28 days at rate B (advanced HF). Data were collected at baseline and moderate, severe, and advanced HF during submaximal exercise testing and by transthoracic echocardiography in sinus rhythm. There were marked increases in left ventricular (LV) area, mitral valve regurgitation, and LV end-diastolic pressure and decreases in LV wall thickness, LV ejection fraction, positive and negative dP/dt(max), and positive (dP/dt(max))/P throughout the pacing protocol. CONCLUSIONS: This ovine HF model incorporates the progressive nature of human HF and allows examination of both structural changes and hemodynamic parameters of HF during and after exercise challenge.

Emergency endovascular stent-graft repair for thoracic aortic injury.

We report a case of emergency endovascular stent-graft repair of a traumatic false aneurysm of the thoracic aorta. Thoracotomy was relatively contraindicated because the patient also sustained incomplete spinal injury, He recovered fully from both chest and spinal injuries, and remains without evidence of complications related to the stent-graft 18 months after the injury.

Double-breasted repair of the posterior mitral valve leaflet.

The double-breasted repair of the posterior leaflet of the mitral valve is an alternative technique for correction of mitral regurgitation in selected patients. This new technique has the advantage of avoiding distortion of the posterior annulus and simplifies the repair, especially in complex posterior leaflet prolapse.