Contemporary results for isolated aortic valve surgery.

BACKGROUND: We aimed to give an overview of the contemporary status of aortic valve replacement. MATERIALS AND METHODS: This single-center prospective study was initiated in January 2003. From this date on, every patient with aortic valve disease admitted to our hospital was reviewed by a cardiologist and a surgeon to determine eligibility for replacement. In no instance was the operation denied in the absence of surgical consultation. All operations were performed using a median sternotomy, with cardiopulmonary bypass and cardioplegic arrest. RESULTS: A total of 873 cases were screened until the end of the study. We identified three groups of patients: Group 1 (inoperable cases) consisted of 15 patients (1 %); Group 2 (high-risk cases) included 99 patients with an additive EuroSCORE ≥ 10 or an expected mortality > 20 % (logistic model); Group 3 (moderate- to low-risk cases) consisted of 759 patients with an additive EuroSCORE < 10 or an expected mortality < 20 %. In-hospital mortality was 6.0 % (6/99) for Group 2 and 0.3 % (3/759) for Group 3. Major complications occurred in 5 patients of Group 2 (5 %) and in 9 patients of Group 3 (1.1 %). At predischarge echocardiography, 99.3 % of the implanted valves were perfect. At a follow-up of 28.9 ± 12.3 months 798/849 patients were alive; 89 % of them (711) were in NYHA 1-2. CONCLUSIONS: Surgical aortic valve replacement provides excellent results and has a low operative mortality even in high-risk patients. Surgical consultation for every aortic patient resulted in an extremely low rate of surgery refusals. Our data should be regarded as a benchmark for transcatheter techniques.

The unclampable ascending aorta in coronary artery bypass patients: A surgical challenge of increasing frequency.

BACKGROUND: The unclampable ascending aorta (UAA) is a condition increasingly encountered during CABG procedures. We report our experience with CABG patients with UAA and place particular emphasis on the preoperative diagnosis and surgical management. METHODS AND RESULTS: UAA was diagnosed in 211 of 4812 consecutive CABG patients (4.3%). On the basis of the chest radiograph, echocardiogram, and coronary angiograph, a preoperative diagnosis was achieved in only 58 patients (27.4%). An age of >70 years, diabetes, smoking, unstable angina, diffuse coronaropathy, and peripheral vasculopathy were all predictors of UAA. Patients were treated with hypothermic ventricular fibrillation (no-touch technique n=129) or beating heart revascularization (no-pump technique n=82) depending on the possibility of founding an arterial cannulation site. The overall in-hospital mortality rate was 2.8% (6 of 211) with no differences between the 2 surgical strategies. The no-touch technique was associated with a greater incidence of neurological complications (stroke and transient ischemic attack), renal insufficiency, and stay in the intensive care unit and hospital. However, at midterm follow-up, more patients of the no-pump group had ischemia recurrence. CONCLUSIONS: A preoperative diagnosis of UAA is achievable only in a minority of patients, which highlights the necessity revising the current diagnostic protocols. The use of the no-touch technique is associated with an high perioperative risk but a superior possibility of complete revascularization, whereas adoption of the no-pump strategy ensures a smoother postoperative course at the expense of an higher incidence of ischemia recurrence.

Patent side branches do not affect coronary blood flow in internal thoracic artery-left anterior descending anastomosis: an experimental study.

BACKGROUND: It has been reported that large side branches of internal thoracic artery grafts may steal flow from the coronary circulation. Material an. METHODS: To assess the importance of the side branches, we measured the proximal and distal flow and pressures (mean subclavian artery pressure and mean arterial anastomotic pressure) at baseline and during infusion of adenosine (0.5 mg/kg/min) in 10 Landrace pigs in which an internal thoracic artery-left anterior descending anastomosis was constructed without interruption of the side branches. The difference between proximal and distal flow was considered to represent the blood flow of the internal thoracic artery side branches. Measurements were then repeated after surgical occlusion of all the side branches. RESULTS: At baseline, blood flow of the side branches represented 18% of the total flow in the proximal internal thoracic artery, and this percentage remained constant under the infusion of adenosine, which caused a 220% increase of the cardiac index and a 368% increase of the proximal flow. The infusion reduced the gradient along the left internal thoracic artery (mean subclavian artery pressure-mean arterial anastomotic pressure) from 15 to 10 mm Hg (P =.02) as the result of a lower mean subclavian artery pressure, although the mean arterial anastomotic pressure remained constant. Interruption of all the side branches resulted in a small and not significant increase in distal flow even after adenosine infusion. CONCLUSION: These observations suggest that blood flow in the side branches is minimal either at baseline and under combined systemic and coronary vasodilation. Clinically significant flow steal from the coronary circulation to the internal thoracic artery side branches seems then unlikely.

Time dependence of endothelium-mediated vasodilation by intermittent antegrade warm blood cardioplegia.

BACKGROUND: The technique of intermittent antegrade warm blood cardioplegia (IAWBC) exposes the heart to brief periods of normothermic ischemia. This may impair endothelial function in coronary arteries. METHODS: Three cardioplegic technique were tested in porcine hearts arrested for 32 to 36 minutes and reperfused for 30 minutes: IAWBC, antegrade cold blood cardioplegia (ACBC), and antegrade cold crystalloid cardioplegia (ACCC). In the hearts arrested with IAWBC, three different intervals of ischemia were used: three 10-minute intervals (IAWBC1), two 15-minute intervals (IAWBC2), and one 30-minute interval (IAWBC3). Rings from the coronary arteries were used to evaluate in vitro the contractile responses to U46619 and the relaxant responses to bradykinin, A23187, and sodium nitroprusside. RESULTS: All six groups (treatment groups and control group) displayed similar responses to U46619 (30 nmol/L) and nitroprusside. In the IAWBC1, IAWBC2, AND ACBC groups, endothelium-dependent relaxations to bradykinin and A23187 were preserved compared with controls, whereas those of the ACCC and IAWBC3 groups were significantly impaired (bradykinin: control, 8.72 +/- 0.07; IAWBC1, 8.73 +/- 0.03; IAWBC2, 8.65 +/- 0.05; IAWBC3, 8.30 +/- 0.07 [p < 0.05]; ACBC, 8.50 +/- 0.03; ACCC, 8.25 +/- 0.09 [p < 0.05]; A23187: control, 7.07 +/- 0.08; IAWBC1, 7.07 +/- 0.06; IAWBC2, 7.04 +/- 0.03; IAWBC3, 6.64 +/- 0.01 [p < 0.05]; ACBC, 6.80 +/- 0.05; ACCC, 6.60 +/- 0.08 [p < 0.05]; nitroprusside: control, 6.19 +/- 0.1; IAWBC1, 6.19 +/- 0.07; IAWBC2, 6.03 +/- 0.03; IAWBC3, 6.08 +/- 0.05; ACBC, 6.04 +/- 0.2; ACCC, 6.05 +/- 0.03; all values are expressed as the negative logarithm of the concentration producing 50% of the maximal response). CONCLUSIONS: Myocardial preservation with IAWBC with ischemic intervals of 15 minutes or shorter does not alter the endothelium-dependent relaxation to bradykinin or A23187 in porcine coronary arteries, but these responses are significantly impaired by ACCC and IAWBC with an ischemic interval of 30 minutes.

Individualized surgical strategy for the reduction of stroke risk in patients undergoing coronary artery bypass grafting.

BACKGROUND: This study was designed to evaluate the efficacy of a protocol of systematic screening of the ascending aorta and internal carotid arteries and individualization of the surgical strategy to the ascending aorta and internal carotid arteries status in reducing the stroke incidence among patients undergoing coronary artery bypass grafting. METHODS: On the basis of a pre- and intraoperative screening of the ascending aorta and internal carotid arteries, 2,326 consecutive patients undergoing coronary artery bypass grafting were divided in low, moderate, and high neurologic risk groups. In the high-risk group dedicated surgical techniques were always adopted and the reduction of the neurologic risk was considered more important than the achievement of total revascularization. RESULTS: The incidence of perioperative stroke in the high-risk group was similar to those of the other two groups (1.1 versus 1.3 and 1.1%, respectively; p = not significant); however, angina recurrence was significantly more frequent in the high-risk group. CONCLUSIONS: The described strategy allows a low rate of perioperative stroke in high-risk patients undergoing coronary artery bypass grafting. Whether the reduction of the neurologic risk outweighs the benefits of complete revascularization remains to be determined.

Technique of sequential grafting the left internal mammary artery (LIMA) to the circumflex coronary system.

The most common grafting technique performed with the IMA's is to anastomose the LIMA to the Left Anterior Descending (LAD) coronary system. With the expanded use of this conduit, the Right IMA (RIMA) can be used to graft the LAD system and the LIMA can be routed to the Circumflex (Cx) coronary system. This is the most common graft design in case of coronary disease affecting the LAD and the circumflex systems. The technique used at the Medical Center "The Klokkenberg" since 1989 to route the LIMA to the marginal arteries through a pericardial window is described in detail.

Current results of coronary bypass surgery after failed angioplasty.

Percutaneous Transluminal Coronary Angioplasty (PTCA) is a technique in continuous development. Since its introduction indications, number, quality of stenosis amenable to treatment and device employed have evolved leading to a change in the population undergoing treatment. Therefore surgical results obtained in the early 80's may not apply to the beginning of the 90's. This reason prompted us to review our recent experience. In the last 4 years (1989-1992) among 2563 PTCA procedures performed in our Institution, 114 patients (4.3%, CL 3.5%-5%) underwent urgent surgical revascularization because of failed angioplasty. Thirty-four patients (30%, CL 21%-38%) were older than 65 years; 68 patients (60%, CL 50%-68%) had multiple vessel disease; 63 patients (55%, CL 46%-64%) had previous Myocardial Infarction (M.I.); 20 patients (17%, CL 10%-24%) had already undergone a PTCA and 3 patients (2%, CL 0%-6%) had had coronary surgery. In 21 patients (18%, CL 11%-25%) the left ventricular Ejection Fraction (EF%) was below < 50%. Complete revascularization was always performed with an average of 2.2 +/- 1 graft/patient. A Left Internal Mammary Artery (LIMA) was implanted in 20 patients (17%, CL 10%-25%) of the patients and in 52% of cases requiring LAD grafts in the last two years. There were 2 deaths (1.7%, CL 0%-4%), both patients were in cardiac arrest before surgery (p < 0.001), 2 patients required a LVAD to be weaned from ECC and 7 patients (6%, CL 1%-10%) had an IABP inserted at the moment of surgery. Twenty-five patients (21%, CL 14%-29%) showed evidence of a new myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Internal mammary artery grafts and competitive flow. Controversies persist.

We report one case in which chronic native competitive flow from an almost normal target coronary artery did not influence IMA graft patency. This patient underwent control postoperative angiography 11 months after surgery and the mammary artery-left anterior descending graft was found to be normofunctioning despite the fact that the coronary artery showed no residual stenosis.

The use of pulmonary allografts for aortic valve replacement. Short term results and comparative morphometric analysis of the aortic and pulmonary valves.

UNLABELLED: The satisfactory results of aortic valve replacement with pulmonary autograft and the limited availability of aortic allografts prompted us to use the pulmonary valve as an aortic valve substitute and to perform a morphometric analysis of the two valves in cadavers. CLINICAL STUDY: From March 1994 to March 1995 20 patients underwent an aortic valve replacement (AVR) with a pulmonary allograft (PA). Twelve patients were men, 8 women; age ranged from 15 to 58 years. In 4 cases the indication to AVR was an infective endocarditis which was acute in two patients. Functional class was NYHA II in 18 cases and NYHA III in 2 patients with active endocarditis. Left ventricular ejection fraction (LVEF%) was preserved in the majority of patients (mean LVEF=53% range 36% to 65%). End diastolic aortic valve diameters were measured by bidimensional echocardiography in parasternal long axis view and ranged from 18 mm to 29 mm. The diameters of the allografts implanted ranged from 19 mm to 27 mm. Donors age ranged from 19 years to 55 years. We tried to use the allograft from the youngest donor available. The surgical technique was the classic "Ross" coronary freehand implantation in 11 cases, a "Miniroot" implant in 8 instances and a "Miniroot" implant combined with a "Nicks" annular enlargment in 1 case. Aortic cross clamping ranged from 66 mm to 118 m (92m+/-10m). One patient died (5%) of infarction. In this patient the allograft was replaced with a mechanical valve because the echocardiography showed a rapidly increasing aortic regurgitation. At hospital discharge a slight aortic regurgitation was detected in 2 cases. In these two patients, whose annulus diameters were 26 mm and 28 mm respectively, we adopted a classic freehand technique of implantation. Mean postoperative transvalvular gradient was 4 mmHg+/-3 mmHg. The follow-up ranges from 45 days to 14 months (mean 8 months). The aortic regurgitation in the two cases remains stable and no new aortic regurgitations have been detected to date. No embolic or infective episodes occurred during the follow-up. ANATOMIC STUDY: Analysis was performed on 6 couples of valves obtained from cadevers without evidence of previous valvular disease. The normalized Free Edge (FE) dimensions and Leaflet Surfaces (LS) of the pulmonary valve (PV) proved to be larger than the corresponding aortic (AV) measurements (Free edge/Diameter: PV 1.25+/-0.2 vs AV 1.16+/-0.2 p<0.05; Annular Attachment/Diameter PV 1.9+/-0.1 vs AV 1.74+/-0.2 p=NS; Valve Surface/Leaflet Surface PV 0.97+/-0.2 vs AV 0.80+/-0.2 p=0.004) indicating that the PV has a larger coapting surface.

Mycotic false aneurysm of the descending thoracic aorta due to Candida albicans: successful removal and in situ grafting.

We report the successful removal of a mycotic false aneurysm of the descending thoracic aorta. The aneurysm developed after a sepsis secondary to Canadida albicans. General signs of infection were absent at the time of surgery, although the aortic wall was still infected. A Dacron graft was inserted after resection of the entire aortic wall, and irrigation of the left pleura with amphotericin B was started postoperatively. The patient recovered fully and is in good condition one year after the operation.

Preliminary experience with a percutaneous cardiopulmonary support system.

Percutaneous cardiopulmonary bypass has been introduced to support circulation in critical patients. In our preliminary experience we resuscitated two patients who sustained a prolonged cardiac arrest (52 min. and 31 min.) after coronary angiography and elective cardiac surgery, respectively. Cannulation was achieved percutaneously within 10 min. in both cases. Pump flow ranged from 2 to 31/m. Total support lasted from 52 min. to 180 min.. Both patients were successfully weaned. Patient 1 was declared brain dead and expired 17 days later. Patient 2 was discharged from the hospital and is doing well. Cannulation was attempted in a third patient after 30 min. of cardiac arrest. Despite surgical cut down of the femoral vessels, it was impossible to advance the arterial cannula because of bilateral occlusive disease. We conclude that PCPS is a powerful technique in selected patients to recover a stable cardiac function after prolonged cardiac arrest.

[Postoperative complications and therapeutic management after aneurysmectomy of the left ventricle]. / Complicazioni ed indirizzo terapeutico post-operatorio dopo aneurismectomia del ventricolo sinistro.

51 patients underwent left ventricular aneurismectomy between 1975 and 1980. In 37 patients a Mitral Valve Replacement and/or Myocardial Revascularization were associated. Low cardiac output and ventricular arrhythmias accounted for more than 50% of the problems encountered. Hospital mortality was 11.7%. Low cardiac output and ventricular fibrillation were the only causes of death, and 60% of the times they affected patients who had a Mitral Valve Replacement + Myocardial Revascularization associated to the aneurysmectomy. Left ventricular aneurysmectomy profoundly alters the geometry of the left ventricle which tends to be in a negative oxygen balance during the first postoperative hours with ischemia and possible cardiac failure ensuing. The thorough monitoring of the filling pressures of the left ventricle and the prompt and aggressive therapy of the complications are a must and strongly contributed to lower the hospital mortality after left ventricular aneurysmectomy.

Surgical correction of congenital left coronary-pulmonary artery fistula and rheumatic mitral valve disease. Case report.

A 56-year-old woman with stenosis and incompetence of the mitral valve and clinical signs of congestive heart failure was found to have a communication between the left anterior descending coronary artery and the pulmonary trunk. A mitral valve prosthesis was inserted and the fistula was closed from within the pulmonary artery.