Aortic valve replacement and coronary artery surgery: determinants affecting early and long-term results.

BACKGROUND: We studied factors influencing early and late results in patients operated on for aortic valve replacement and coronary artery bypass graft. METHODS: 175 patients were retrospectively analysed over a 10-year period ending in December 2002. There were 135 males and 40 females with a mean age of 62.7 +/- 8.9 years; 109 were in NYHA class III/IV; 45 required an urgent operation, and 103 mechanical valves and 72 biological valves were implanted. RESULTS: There were 11 operative deaths (6.3 %). Statistical analysis (logistic regression) showed that previous myocardial infarction, poor NYHA class, and low LVEF had a significant effect on early death. There were 52 late deaths at a mean follow-up of 82.7 +/- 38.8 months. Using a Cox survival analysis for any causes, age, urgent operation, low LVEF, and creatinine had a strong impact on unfavourable late outcome. CONCLUSIONS: A combination of a patient-related factor (age), cardiac-related condition (low LVEF), co-morbid condition (renal dysfunction), and operative cause (urgent operation) is the most important predictor of late clinical outcome for this combined surgical procedure.

Endovascular vs. open surgery of abdominal aortic aneurysm in high-risk patients: a single center experience.

BACKGROUND: We compared two groups of high-risk patients with abdominal aortic aneurysm to assess the safety and efficacy of endovascular repair vs. open surgery. METHODS: From January 1998 to July 2003, sixty-two high-risk patients were divided into two groups: group A consisted of 28 (46 %) open surgery patients and group B consisted of 34 (54 %) patients who underwent endovascular repair. RESULTS: Four patients (14.3 %) in the open surgery group died, while no deaths occurred in the endovascular group ( p < 0.05). There were 14 complications in 8 patients of the open surgery group versus 2 complications in 2 patients of the endovascular group ( p = 0.01). At follow-up there were 4 (16.6 %) deaths in group A and 3 (8.8 %) in the endovascular group ( p = n. s.). CONCLUSIONS: While the use of endovascular repair in patients who are physiologically fit for open surgical repair remains controversial, we believe that patients with multiple or advanced comorbidities, i.e. high-risk patients, can benefit from the endografting procedure.

Discrete subaortic stenosis: long-term prognosis on the progression of the obstruction and of the aortic insufficiency.

BACKGROUND: We sought to determine the long-term rate of progression of left ventricular outflow tract (LVOT) obstruction and aortic insufficiency (AI) in adult patients operated on for discrete subaortic stenosis (DSS). METHODS: Between 1975 and 1995, 52 patients underwent surgery for DSS; their mean age was 25.4 +/- 14.8 years. Mean preoperative LVOT gradient was 72.8 +/- 25.7 mm Hg. Excision of the subaortic membrane was carried out in all patients, myectomy of the interventricular septum was additionally carried out in 8 patients (15.4 %), and aortic valve replacement (AVR) was performed in 15 patients (28.8 %). RESULTS: There were 2 operative deaths (3.8 %). Early postoperative LVOT gradient was 9.7 +/- 6.5 mm Hg. Follow-up ranged from 8.1 to 26.6 years. There were 8 late deaths (16.3 %), and mean LVOT gradient was 13.3 +/- 10.7 mm Hg. Five patients required reoperation for recurrent obstruction; 4 patients had a gradient of more than 30 mm Hg. The AI, in patients who did not undergo aortic valve replacement, did not substantially change during follow-up. CONCLUSIONS: DSS is a variable, unpredictable and progressive disease; recurrent obstruction may reappear despite the adequacy of surgical excision, and is not related to preoperative gradient. Mild AI remains substantially unchanged and AVR is indicated in severe AI.

Can epsilon-aminocaproic acid balance the off-pump bleeding advantage?

BACKGROUND: Aprotinin improved the control of bleeding in patients undergoing surgery with cardiopulmunary bypass, but its use was halted because of the risk of bovine spongiform encephalopathy. We then started to use epsilon-aminocaproic acid and the results in the control of bleeding were satisfactory. To assess its effectiveness in the control of postoperative bleeding precisely, we compared the results for patients operated on for myocardial revascularization on-pump and treated with epsilon-aminocaproic acid with those for patients who decidedly bleed less: off-pump patients. METHODS: Two groups of patients who had had either on- or off-pump double aortocoronary bypass surgery were retrospectively reviewed for postoperative bleeding. These two almost homogeneous group had two grafts only: left anterior descending and circumflex arteries operated on with cardiopulmonary bypass and treated with the epsilon-aminocaproic acid, and left anterior descending and right coronary arteries operated on off-pump. RESULTS: Postoperative bleeding through chest drainage at 4 h was 265+/-91.7 mL in the off-pump group and 328.4+/-131.4 mL in the on-pump group (p=0.004). But at 24 h it was 671.6+/-311.5 mL in the off-pump group and 827.8+/-514.4 mL in the on-pump group (p=0.07). CONCLUSIONS: epsilon-Aminocaproic acid is effective in controlling postoperative bleeding in patients operated on for myocardial revascularization with the aid of cardiopulmonary bypass.

Detection of postoperative pseudoaneurysms following abdominal aortic aneurysm repair in Behçet's disease by MRA.

We report the development of two anastomotic pseudoaneurysms in a patient with Behçet's disease eighteen months after abdominal aortic aneurysm repair. Major asymptomatic vascular complications should be suspected in patients with Behçet's disease with a history of vascular surgery and treated expediently due to the risk of rupture. Magnetic resonance angiography, contrast-enhanced computed tomography or ultrasound scanning should be performed at least every 6 months after vascular surgery.

One-stage coronary and abdominal aortic operation with or without cardiopulmonary bypass: early and midterm follow-up.

BACKGROUND: The aim of this study was to compare hospital, early, and late clinical outcomes for patients undergoing one-stage, coronary and abdominal aortic surgical intervention with and without cardiopulmonary bypass. METHODS: From March 1990 to September 1999, 42 consecutive patients underwent combined operations at a single institution. Cardiopulmonary bypass and cardioplegic arrest were used during coronary revascularization in the first 20 patients (on-pump group), and the next 22 patients received the one-stage operations on the beating heart (off-pump group). RESULTS: Baseline characteristics were similar between groups. Three cardiac-related hospital deaths occurred in the on-pump group and one such death in the off-pump group (p = 0.25). Cardiac-related events, pulmonary complications, inotropic support, blood loss and transfusion requirements, intensive care unit stay, and hospital stay were significantly reduced in the off-pump group (all, p < 0.05). The actuarial survival rates in the on-pump and off-pump groups were 80% and 95%, respectively, at 1 year (p = 0.13) and 75% and 89%, respectively, at 3 years (p = 0.22). Freedom from cardiac-related events at 1-year follow-up was 91% in the off-pump group and 65% in the on-pump group (p < 0.05). No difference in cardiac-related events between groups was observed at 3 years. CONCLUSIONS: Off-pump coronary surgical procedures decrease postoperative complications in high-risk patients undergoing simultaneous coronary and abdominal aortic operations compared with the conventional one-stage procedure. The early benefits achieved with off-pump surgical intervention are not at the expense of the long-term clinical outcome.

L-arginine improves post-ischemic vasodilation in coronary heart disease patients taking vasodilating drugs.

BACKGROUND: The hypothesis that intravenous L-arginine infusion improves the vasodilatory response to ischemia in the resistance vessels of human lower limbs in relatively young coronary heart disease patients taking vasodilating drugs was tested. METHODS: Twenty patients with onset of symptoms of coronary artery disease before age 50, operated for aortocoronary bypass and taking vasodilating drugs, were compared with 20 control subjects of comparable age and gender; neither group included heavy smokers (>10 cigarettes/day). Blood flow in the lower limbs was measured noninvasively with strain-gauge plethysmography, both at rest and during a reactive hyperemia test. Intravenous infusion of L-arginine was performed in nine coronary heart disease patients and in nine control subjects. RESULTS: Resting blood flow to the lower limbs was 2.3 mL/min/100 mL in control subjects vs 3.4 mL/min/100 mL in patients (difference not statistically significant). Peak blood flow measured after a 3-minute arterial occlusion was 24.0 mL/min/100 mL in control subjects vs 20.3 mL/min/100 mL in coronary heart disease patients (P<0.05). Peripheral minimal vascular resistances were 4.28 and 5.46 peripheral resistances units (p.r.u.) in control subjects and patients, respectively (P<0.05). Intravenous infusion of L-arginine was followed by increased resting blood flow in cases and controls (P=0.009), with a parallel reduction in peripheral resting vascular resistances (P=0.009). Coronary heart disease patients showed increased peak blood flow (P=0.04) and reduced minimal vascular resistances (P=0.02), whereas no statistically significant changes in these parameters were detectable in control subjects. Intravenous glucose infusion, leading to increased serum insulin concentration, did not modify any hemodynamic parameter. CONCLUSIONS: Hemodynamic responses in the skeletal muscle are impaired during a reactive hyperemia test in relatively young coronary heart disease patients taking vasodilating drugs. Intravenous L-arginine infusion corrects the impaired vasodilatory response of the lower limbs to an acute increase in flow following a cuff thigh occlusion.

Surgical myocardial revascularization (CABG) in patients with pulmonary disease: beating heart versus cardiopulmonary bypass.

BACKGROUND: Adverse effects on the respiratory system can be severe in many instances after coronarv artery bypass grafting (CABG) with cardiopulmonary bypass (CPBP). Recently, operative techniques without CPBP have gained widespread consent, thanks to the newly developed retractors that allow satisfactory immobilisation of the surgical field. METHODS: Thirty-seven patients operated upon in our Institution between April 1997 and April 1998 showed an obstructive and/or restrictive pulmonary disease. Twenty-one patients were operated on without CBPB (group A), while 16 patients were operated using CPBP (group B, control). The allocation in each group had been randomised. RESULTS: The length of the operation in group A was less than in group B (196+/-35 minutes vs 235+/-60 minutes), (p=0.014). A significant difference was found in postoperative bleeding: 562+/-381 ml vs 776+/-378 (p=0.046), in postoperative red cell count, hemoglobin level and Hct. Permanence on the ventilator was 19.1+/-13 hours in group B and 13.1+/-6.1 hours in group A (p=0.03). The length of stay in ICU was significantly different: 33.8+/-16.2 hours for group A vs 53.6+/-29.3 hours for group B (p=0.01). No respiratory failure occurred in group A; two patients experienced slow weaning from ventilation assistance and one died from that complication in group B. CONCLUSIONS: Myocardial revascularization without CPBP allows a better postoperative clinical course in patients with advanced pulmonary disease.

Mid-term results of the valve-on-valve technique for bioprosthetic failure.

OBJECTIVE: Redo operations for bioprosthesis malfunction can sometimes be technically very demanding and cardiac structures may be damaged. Excising only the leaflets of the damaged bioprosthesis and leaving the old ring in situ on which the 'new' mechanical valve is sutured can, in very selected cases, represent a solution. METHODS: Twenty-two patients were operated on, with the valve-on-valve technique, from September 1991 through December 1992. There were three operative deaths. RESULTS: The surviving 19 patients were followed-up from 83 to 98 months (mean 90.5 months.). There were two late deaths. The patients were examined clinically and with transthoracic and transesophageal echocardiograms. All patients were in good condition and the echocardiographic examinations showed no clinically important gradients across the prostheses. CONCLUSIONS: The valve-on-valve technique, in certain difficult situations, can give successful mid-term results.

Combined coronary artery and abdominal aortic surgery without cardiopulmonary bypass.

To determine the effects of beating heart surgery on patients undergoing simultaneous coronary artery bypass grafting and abdominal aortic surgery, we performed such surgery on 20 patients (mean age, 64.55+/-796 SD years). Abdominal aortic disease was defined as an abdominal aortic aneurysm larger than 5 cm in diameter or as end-stage aortic occlusive disease. Hemodynamic measurements, inotropic requirements, and incidence of perioperative myocardial infarction and arrhythmias were recorded, as were subsystem clinical outcomes, length of intensive care unit and hospital stays, blood loss, and transfusion requirements. There was no incidence of death, perioperative myocardial infarction, stroke, or acute renal failure. The mean number of grafts per patient was 1.95+/-0.69. Only 4 minor postoperative complications were observed: three patients (15%) had evidence of supraventricular tachyarrhythmias, and 1 patient (5%) had chest infection that required a longer-than-average intubation period. Six patients (30%) required minimal-to-moderate inotropic support. The mean blood loss was 673+/-246.8 mL and transfusion requirements were low. The mean intensive care unit and hospital lengths of stay were 2. 12+/-0.33 days and 708+/-1.44 days, respectively. Clinical follow-up (mean, 10 months) showed all patients to be in New York Heart Association functional class I or II with no late cardiac or abdominal events. We conclude that simultaneous coronary artery bypass grafting and abdominal aortic surgery on the beating heart is safe and effective, and has a low perioperative clinical morbidity rate. To our knowledge, ours is the 1st report on this procedure. Larger studies with longer follow-up are needed.

[The complications of implantable cardioverter-defibrillators and their treatment]. / Complicanze dei defibrillatori cardiovertitori impiantabili e loro trattamento.

Infection of implantable cardioverter defibrillator (ICD) is a devastating event. In an effort to more fully understand ICD infection, the authors reviewed patients records recommending a strategy for management based on their satisfactory experience. From March 1993 through May 1998, 85 ICD were implanted in 64 male and 21 female patients. Transmediastinal approach was performed in 8 (9.5%) cases and transvenous in 77 (91.5%). All device-related infections were examined. Seven (8.25%) device-related infections occurred with a mean time interval of 3 months. In all cases bacterial infection was demonstrated. All infections involved the generator with or without other components involvement. First approach was conservative in all cases but it wasn't successful. Then the authors always used a surgical therapy, in 3 cases removing electrodes by traction and in 4 resorting to cardiopulmonary bypass (CPB). Two deaths were registered. Explantation of ICD resolved in all cases infective complications with no early or additional reinfections. In the last cases with devices implanted by transvenous approach and subpectoral generator implant, no infective complications were observed. In authors experience a complete removal of the ICD generator as well as of all its components is to be preferred as soon as the infections develops.

Determinants of aortic artifacts during transesophageal echocardiography of the ascending aorta.

BACKGROUND: The origin of artifacts of the ascending aorta during transesophageal echocardiography has not been widely studied. This study was undertaken to investigate in vivo whether anatomic features could determine the appearance of artifacts. METHODS AND RESULTS: Transesophageal echocardiograms of 46 patients studied for suspected dissection with proven diagnosis (30 patients with and 16 without ascending aortic dissection) were reviewed. The incidence of artifacts was 46%, and it was similar in patients with and those without dissection (chi-square 0.516; P = not significant). Artifacts were located in the aortic lumen twice as far from the transducer as the atrial-aortic interface. The aortic diameter was larger in patients with than in those without artifacts (6.4 +/- 1.1 vs 4.2 +/- 0.9 cm, P <.001). An aortic diameter >5 cm and an atrial-aortic ratio 5.0 cm that exceeds the left atrial diameter with an atrial-aortic ratio

Open chest myocardial biopsy: a simple and safe method.

The authors describe a simple method to perform left ventricular biopsies during open heart surgery. An automatic gun shaped device is used by one hand of the surgeon: the sample is obtained in a few seconds, at any time of the surgical procedure. It consists of a transmural piece of tissue, averaging 18 mm3 in quantity. The device has been used in 20 patients who underwent coronary artery revascularization. All the biopsies were successful. No complications occurred.

Bioprosthetic replacement after bioprosthesis failure: a hazardous choice?

BACKGROUND: Following bioprosthetic failure, replacement is usually done with mechanical valves to avoid repeated reoperations. METHODS: From 1986 to 1996 we operated on 130 patients with bioprosthetic failure, implanting a new bioprosthesis; this group included patients with contraindication to anticoagulation, tricuspid replacement, and specific patient requests. Mean age was 63+/-8 years. RESULTS: The perioperative mortality was 13.8%. At 10 year follow-up the actuarial estimate of survival was 77.4%+/-6.6%. Freedom from structural valve deterioration was estimated at 81.8%+/-6.3%. Freedom from a third operation was estimated at 85.5%+/-5.2%. No patient was permanently anticoagulated. Freedom from thromboembolism was estimated at 91.5%+/-4%, and there were no hemorrhages. Freedom from cardiac-related deaths was estimated at 85.7%+/-5%. CONCLUSIONS: This group of patients received the first valve between 1976 and 1986; the range of the cumulative follow-up reaches 20 years, and the extended survival compares favorably with survival of mechanical valves.

Intermittent warm blood cardioplegia preserves myocardial beta-adrenergic receptor function.

BACKGROUND: Left ventricular dysfunction is frequently observed in patients after hypothermic cardioplegic arrest, and often inotropic intervention is necessary for patients to be successfully weaned from cardiopulmonary bypass (CPB). A myocardial beta-adrenergic receptor (beta AR) desensitization has been noted to occur after hypothermic CPB in patients undergoing coronary artery bypass grafting. This randomized study was undertaken to determine the effect of cardioplegic solution temperature on cardiac beta ARs. METHODS: Two groups of patients (20 patients in each) scheduled for elective coronary artery bypass grafting underwent CPB with either intermittent warm or cold blood cardioplegia. The density of the beta ARs, the proportion of beta 1- to beta 2-adrenergic receptors, and the beta AR coupling capacity to adenylate cyclase were determined in specimens of the right atrial tissue at baseline, during CPB, and after discontinuation of CPB. Plasma concentrations of catecholamines were also measured in both arterial and coronary sinus samples. RESULTS: In both cardioplegia groups, no significant modification in either the beta AR density or the proportion of beta 1- to beta 2-adrenergic receptors was detected. However, a significant decrease in adenylate cyclase activity after stimulation with isoproterenol was observed in the cold blood cardioplegia group during CPB (p < 0.01) and 30 minutes after its discontinuation (p < 0.05). Moreover, a significant decrease in adenylate cyclase activity during CPB was detected in this group after stimulation with sodium fluoride (p < 0.05), but this pattern was found to be completely reversed by 30 minutes after discontinuation of CPB. No modification in the basal or stimulated adenylate cyclase activity was observed in the warm blood cardioplegia group during or after CPB. CONCLUSIONS: Our results confirm the finding from previous studies of a cardiac beta AR desensitization after hypothermic cardioplegic arrest, and provide evidence of the advantages of intermittent warm blood cardioplegia in preserving the autonomic sympathetic function of the heart.

Aortic valve replacement through a minimally invasive approach.

Minimally invasive cardiac surgery is rapidly gaining interest because of fast recovery, reduced morbidity, shorter hospital stay, lower costs, and better cosmetic results. Aortic valve surgery can be performed through a small (10- to 12-cm) transverse sternal incision, and femoro-femoral cannulation is used for cardiopulmonary bypass. Exposure of the ascending aorta is satisfactory. From 1 March through 30 September 1996, 7 patients underwent aortic valve replacement through this approach. The mean age of the 5 women and 2 men was 58.8 years. We used this technique mainly in patients with chronic obstructive pulmonary disease, diabetes, or obesity, in the absence of coronary artery disease. There was no mortality, nor was there reoperation for bleeding, stroke, or wound infection. All patients were extubated after 2 hours in intensive care and were discharged on the 4th postoperative day. Additional cases are needed to properly assess the correct indication and surgical technique.

Role of catheter-induced mechanical trauma in localization of target sites of radiofrequency ablation in automatic atrial tachycardia.

OBJECTIVES: We compared the efficacy of two different mapping techniques in identifying the ablation site for atrial tachycardia. Moreover, we evaluated the additive positive predictive value of mechanical interruption of atrial tachycardia to reduce the number of ineffective radiofrequency applications. BACKGROUND: Radiofrequency catheter ablation has been suggested as a highly effective technique to treat drug-resistant atrial tachycardia. However, irrespective of the mapping technique utilized, success was most often achieved with a large number of radiofrequency applications. METHODS: Forty-five patients with atrial tachycardia underwent radiofrequency catheter ablation. Mapping techniques included identification of earliest atrial activation and pace-mapping concordant sequence. RESULTS: Atrial tachycardia was successfully treated in 42 (93.3%) of 45 patients with a mean of 3.9 radiofrequency pulses/patient. An interval between the onset of the intracavitary atrial deflection and the onset of the P wave during atrial tachycardia (AP interval) > or = 30 ms (p < 0.001) and pace-mapping concordant sequence (p = 0.01) were all significant predictors of outcome. An AP interval > or = 30 ms and a pace-mapping concordant sequence were highly sensitive (92.8%, 95% confidence interval [CI] 80.5% to 98.5%; 85.7%, 95% CI 71.5% to 94.6%, respectively) but less specific (47.8%, 95% CI 37.9% to 58.2%, 36.8%, 95% CI 27.6% to 47.2%, respectively) in identifying the site of ablation. By using atrial tachycardia mechanical interruption combined with the AP interval >30 ms or the pace-mapping concordant sequence, we obtained a specifically of 76.5% (95% CI 66.4% to 84.0%) and 73.5% (95% CI 63.2% to 81.4%), respectively, and a positive predictive value of 49.2% and 44.6%, respectively. CONCLUSIONS: An AP interval > or = 30 ms and a pace-mapping concordant sequence were reliable mapping features for predicting the outcome of the ablation procedure. Mechanical interruption of atrial tachycardia improved the specificity and positive predictive value of these two mapping techniques.

Subacute cardiac rupture complicating myocardial infarction. A case report.

The authors have focused this study on the emergence of subacute ventricular free wall rupture in a seventy-six-year-old patient admitted to hospital for inferior acute myocardial infarction. After six days he showed clinical signs of bradycardia and hypotension evolving to electromechanical dissociation. Given an adequate pharmacologic therapy, the patient was submitted to echocardiography, which was believed to be consistent with myocardial rupture, showing a moderate to large pericardial effusion. Pericardiocentesis of 150 mL of bloody fluid resulted in a further improvement in his hemodynamics. The patient underwent cardiac surgery with repair of the myocardial rupture through a large diaphragmatic infarction by a Dacron polyester fiber graft and pacemaker placement. In conclusion the authors confirm the relevant role of clinical data such as persistent chest pain and hemodynamic instability and the value of echocardiography in identifying subacute myocardial free wall rupture after an episode of acute myocardial infarction.

Carotid endarterectomy and myocardial revascularization. A single stage procedure.

Carotid endarterectomy (CEA) and myocardial revascularization can be performed in a single procedure, performing CEA before or during cardio-pulmonary by-pass (CPB), or using a double stage approach. Over a 4 year period, 17 patients underwent CEA and coronary artery by-pass (CAB) with a single stage procedure. Fourteen patients (82.3%) were male, 3 (17.6%) were female. The mean age was 66.3 +/- 7.07. One patient (5.8%) had a previous neurological event (stroke); 5 patients (29.4%) had a previous transient ischemic attacks (TIA). The indications for the combined operations were CAD associated to unilateral internal carotid stenosis greater than 70% or 50% when symptomatic. In all patients CEA was performed after median sternotomy and heparinization, during CPB, with moderate hypotermia (30%C), performing CEA successively. One patient (5.8%) died of acute heart failure secondary to mediastinits. Minor neurological complications were present in 2 patients (11.7%) with signs of cerebral oedema. Myocardial infarction and late neurological deficit did not occur in any patient. We conclude that it is important, in the preoperative assessment of every patients with CAD, the screening for concomitant carotid vascular diseases, in order to avoid neurological complications during CPB, treating the two different diseases with a single stage approach, if carotid stenosis is greater than 70% or greater than 50% when symptomatic.