Influence of concomitant mitral valve dysfunction on survival after aortic valve replacement.

Aortic valve pathology is the most common acquired valvular heart disease in the adults of western countries, and mitral regurgitation (MR) is often clinically present in patients with degenerative aortic stenosis or insufficiency. Many studies report an incidence of MR between 65-75% in patients evaluated for aortic valve replacement. Severe aortic valve disease may be associated with functional mitral regurgitation (FMR) defined as the failure of mitral valve to prevent systolic backward flow in the absence of any significant structural or intrinsic valvular disease. Increased afterload and left ventricular remodeling have been implicated to explain FMR in patients with aortic valve disease. Moreover, organic mitral valve disease can be associated with aortic stenosis and can be rheumatic or degenerative. We have examined the data of the literature to understand the evolution of MR, the impact of mitral regurgitation on the outcome of patients undergoing aortic valve replacement, and to determine clinical predictors of prognosis in patients with concomitant MR at the time of aortic valve replacement.

The double-orifice technique in mitral valve repair: a simple solution for complex problems.

OBJECTIVE: The aim of this study is to report our results with the central double-orifice technique used for the treatment of complex mitral valve lesions. METHODS: The central double-orifice repair has been used in 260 patients (mean age, 56 +/- 14.3 years) over a period of 7 years. The mechanism responsible for mitral regurgitation was prolapse of both leaflets in 148 patients, prolapse of the anterior leaflet in 68, prolapse of the posterior leaflet with annular calcification or other unfavorable features in 31, and lack of leaflet coaptation for restricted motion or erosion of the free edge in 13. Degenerative disease was the cause of mitral regurgitation in 80.8% of the patients, rheumatic disease was the cause in 9.6%, endocarditis was the cause in 6.1%, and ischemic disease was the cause in 2.3%. RESULTS: Hospital mortality was 0.7%, and the overall survival at 5 years was 94.4% +/- 2.59%. Thirteen patients required a reoperation (2 early postoperatively and 11 late during the follow-up), for an overall freedom from reoperation of 90.0% +/- 3.37% at 5 years. Freedom from reoperation was lower in patients with rheumatic valve disease and in patients who did not undergo an annuloplasty procedure. CONCLUSIONS: The effectiveness and durability of the central double-orifice technique were assessed in this study. This type of repair can be a useful addition to the surgical armamentarium in mitral valve reconstruction.

Totally endoscopic computer-enhanced atrial septal defect closure in six patients.

BACKGROUND: Totally endoscopic procedures have been introduced into cardiac surgery with the application of telemanipulating robotic systems. We report 6 cases of closed-chest atrial septal defect (ASD) closure using a robotic device. METHODS: After deflating the right lung, the endoscopic camera and two robotic arms were inserted into the right hemithorax through 8-mm ports. An accessory port was placed for blood suction and for introduction of ancillary endoscopic instruments. After femoral-femoral cannulation for cardiopulmonary bypass (CPB), aortic occlusion, and cardioplegia delivery, the intracardiac correction was carried out in 5 patients with an ostium secundum ASD and in 1 patient with a patent foramen ovale (PFO) and atrial septal aneurysm (ASA). The ASDs were closed with a continuous braided polyester suture. The PFO closure with septal aneurysm plication was carried out with interrupted stiches. RESULTS: Mean CPB and cross-clamp times were 106 +/- 22 and 67 +/- 13 minutes, respectively. Extubation was carried out within the seventh postoperative hour. All patients returned to normal function within the first postoperative week. CONCLUSIONS: Totally endoscopic ASD closure can be carried out safely using robotic techniques with rapid postoperative recovery and an excellent cosmetic result.

Continuous versus intermittent warm blood cardioplegia: functional and energetics changes.

BACKGROUND: The aim of this study was to compare the protective effects of continuous warm blood cardioplegia (CWBC) and intermittent warm blood cardioplegia (IWBC) in an experimental model of blood-perfused, isolated rabbit heart. METHODS: In the CWBC group, cardiac arrest was induced by continuous infusion of blood cardioplegia (10 mEq/L KCl) followed by 30 minutes of reperfusion with blood. In the IWBC group, after 5 minutes of perfusion with blood cardioplegia (10 mEq/L KCl), coronary flow was abolished for 10 minutes, followed by reperfusion with blood cardioplegia for 5 minutes. This sequence was repeated three times for a total period of 45 minutes. Finally the hearts were reperfused for 30 minutes with blood. RESULTS: Infusion of potassium induced a marked increase in coronary perfusion pressure (from 50 +/- 3 to 98 +/- 1 mm Hg; p < 0.01), which remained elevated throughout in the CWBC group, whereas in the IWBC group, it dropped to 0 during each no-flow period. In both groups, cardioplegia resulted in a significant reduction in oxygen consumption (from 5.5 +/- 0.2 to 0.6 +/- 0.03 mL O2.min-1.100 g-1 wet wt; p < 0.01). During CWBC, glucose extraction was significantly reduced (from 152 +/- 10 to 64 +/- 18 micrograms.min-1.g-1 wet wt; p < 0.01). Free fatty acid uptake and creatine kinase and lactate release were not affected. During IWBC, in contrast, a transient but significant release of creatine kinase (from 643 +/- 254 to 2,234 +/- 296 mU.min-1.g-1 wet wt; p < 0.01) and lactate (from 63 +/- 22 to 374 +/- 32 micrograms.min-1.g-1 wet wt; p < 0.01) occurred after each period of ischemia. Despite these metabolic differences, both cardioplegic procedures allowed a prompt and complete recovery of mechanical function and tissue content of high-energy phosphates. CONCLUSIONS: Both CWBC and IWBC exert optimal protection in the isolated blood perfused rabbit heart. Thus, IWBC can be safely used to improve visualization of the surgical field.

Improved results with mitral valve repair using new surgical techniques.

From January 1987 to July 1994, 299 consecutive patients ranging from 4 to 80 years of age underwent mitral repair for pure valve insufficiency due to degenerative disease (59%), rheumatic disease (23%), endocarditis (12%) or ischemic heart disease (6%). During the initial period, a variety of reparative methods were used following the principles originally described by Carpentier. More recently, in our institution other surgical techniques have been introduced: specifically, prolapse of the anterior leaflet was corrected either by replacing the chordae with polytetrafluoroethylene (PTFE) sutures or simply by anchoring the prolapsing free edge to the facing edge of the posterior leaflet ("edge-to-edge" technique). Chordal transposition has also been used occasionally to correct the prolapse of the anterior leaflet. The hospital mortality rate was 1.3%. According to actuarial methods, the overall survival rate was 94% at 7 years, and freedom from reoperation was 86%. Significant incremental risk factors for reoperation were: no use of prosthetic ring, correction of the prolapse of the anterior leaflet by triangular resection or chordal shortening and ischemic etiology of the mitral insufficiency (freedom from reoperation at 7 years was 61%, 56% and 51%, respectively). In the late postoperative period (mean follow-up 3.6 years), 95% of the patients were in NYHA class I or II; four patients had thromboembolic episodes, two hemorrhagic complications and two endocarditis. No patient in whom the prolapse of the anterior leaflet was corrected by the recently introduced technique has required reoperation. The anterior mitral leaflet prolapse was therefore neutralized as an incremental risk factor for reoperation and this has contributed to the improved overall results of mitral valve repair.

Valve repair for traumatic tricuspid regurgitation.

OBJECTIVE: The review of six cases of valve repair for traumatic tricuspid regurgitation in our institution and 74 in the literature in order to assess effective methods of treating this lesion. METHODS: Tricuspid valve regurgitation is a rare complication of blunt chest trauma. Optimal treatment for this condition is still controversial ranging from long-term medical therapy to early surgical correction. We followed the cases of six consecutive patients with post-traumatic tricuspid incompetence who were successfully treated with reparative techniques. All patients were male and their ages ranged from 18 years to 42 years. Valve regurgitation was always secondary to blunt chest trauma due to motor vehicle accident. The mechanism of valve insufficiency was invariably anterior leaflet prolapse due to chordal or papillary muscle rupture associated with annular dilatation. Surgical procedures included Carpentier ring implant (5 patients), Bex posterior annuloplasty (1 patient), implant of artificial chordae (4 patients), papillary muscle reinsertion (2 patients), commissuroplasty (1 patient) and "artificial double orifice" technique (1 patient). RESULTS: Tricuspid insufficiency improved in all patients after the correction. No complications were recorded and all patients were asymptomatic at the follow-up. CONCLUSIONS: Since post-traumatic tricuspid regurgitation is effectively correctable with reparative techniques, early operation is recommended to relieve symptoms and to prevent right ventricular dysfunction.

The hemodynamic effects of double-orifice valve repair for mitral regurgitation: a 3D computational model.

OBJECTIVES: A 3D computational model has been implemented for the evaluation of the hemodynamics of the double orifice repair. Critical issues for surgical decision making and echo-Doppler evaluation of the results of the procedure are investigated. METHODS: A parametric 3D computational model of the double-orifice mitral valve based on the finite elements model has been constructed from clinical data. Nine different geometries were investigated, corresponding to three total inflow areas (1.5, 2.25 and 3 cm2) and to three orifice configurations (two equal orifices, two orifices of different areas, i.e. one twice as much the other one, and a single orifice). The simulations were performed in transit; the fluid was initially quiescent and was accelerated to the maximum flow rate with a cubic function. For each case, some characteristic values of velocity and pressure were determined: velocities were calculated downstream of each orifice, at the centre of it (Vcen1, Vcen2). The maximum velocity was also determined for each orifice (Vmax1, Vmax2). Maximum pressure drops (deltap(max)) across the valve were compared with the estimations (deltap(Bernoulli)) based on the Bernoulli formula (4 V2). RESULTS: In each simulation, no notable difference was observed between Vcen1 and Vcen2, and between Vmax1 and Vmax2, regardless of the valve configuration. Maximum velocity and deltap(max) were related to the total orifice area and were not influenced by the orifice configuration. Deltap(Bernoulli) calculated with Vmax was well correlated with the deltap(max) obtained throughout the simulations (y = 0.9126x + 0.3464, r = 0.996); on the contrary the pressure drops estimated using Vcen underestimated (y = 0.6757x + 0.3073, r = 0.999) the actual pressure drops. CONCLUSIONS: The hemodynamic behaviour of a double orifice mitral valve does not differ from that of a physiological valve of same total area: pressure drops and flow velocity across the valve are not influenced by the configuration of the valve. Echo Doppler estimation of the maximum velocities is a reliable method for the calculation of pressure gradients across the repaired valve.

The edge-to-edge technique: a simplified method to correct mitral insufficiency.

OBJECTIVE: Repair of mitral regurgitation (MR) is more demanding in case of prolapse of the anterior leaflet, posterior leaflet with calcified annulus, or prolapse of both leaflets. We evaluated a repair which consists of anchoring the free edge of the prolapsing leaflet to the corresponding free edge of the facing leaflet: the 'edge-to-edge' (E-to-E) technique. The correction results in a double orifice valve when the prolapse is in the middle portion of the leaflet and in a smaller valve orifice when the prolapse is close to a commissure. METHODS: Out of 432 patients with MR submitted to valve repair between January 1991 and September 1997, 121 (mean age 56 +/- 15.8 years) underwent E-to-E correction. The most prevalent etiology was degenerative disease (82 patients, 68%). The mechanism of MR was anterior leaflet prolapse (61 patients), posterior leaflet prolapse (24 patients), prolapse of both leaflets (28 patients) and other complex mechanisms (8 patients). In 72 patients, a double orifice was created, the paracommissural repair was done in 49 patients. RESULTS: Hospital mortality was 1.6%. Overall survival was 92 +/- 3.1% at 6 years with 95 +/- 4.8% freedom from reoperation. Mortality was unrelated to the type of repair. Mitral stenosis was never observed after the correction. At the follow-up (mean 2.2 +/- 1.5 years), all patients but 15 are class I or II. Symptoms at the follow-up are not related to residual MR. CONCLUSIONS: Midterm results of this alternative repair technique are promising, considering the high prevalence of complex anatomical lesions. The technique is simple, easily reproducible and rapidly feasible also when mitral exposure is suboptimal.

Pericardial patch for rapid and effective hemostasis of cardioplegia injection site.

Cardioplegia injection site may be the source of serious haemorrhagic complications either intraoperatively or during the early postoperative period. Here we describe a simple technique that allows a rapid control of hemostasis at this site. An autologous pericardial patch is used to repair and strengthen the aortic wall.

Totally endoscopic atrial septal defect closure using robotic techniques: report of two cases.

BACKGROUND: The development of minimally invasive cardiac surgery has shown good clinical results with shorter recovery time and better cosmetic results. We report 2 cases of totally endoscopic atrial septal defect (ASD) closure using a robotic system. Open-heart closure of an ASD without opening the chest has never been previously reported. METHODS: Following percutaneous cannulation for cardiopulmonary bypass, aortic occlusion and delivery of cardioplegia, 2 patients with an ASD were successfully operated on using a robotic surgical device. After exclusion of the right lung, two robotic arms and an endoscopic camera were inserted through ports in the right hemithorax. A fourth port was inserted for an accessory endoscopic instrument. The ASD closure was carried out with interrupted stitches in one case and with a continuous suture in the other. RESULTS: Cardiopulmonary bypass and cardioplegic arrest times were respectively 130 and 75 min in the first and 87 and 60 min in the second case. Extubation was carried out 3 and 5 hours postoperatively. Both patients resumed a totally normal lifestyle 1 week after the operation. CONCLUSIONS: Totally endoscopic open-heart ASD closure can be carried out safely using robotic techniques with rapid postoperative recovery and excellent cosmetic results. This modality of treatment can be considered an alternative to the transcatheter closure of ASD.

The use of robotic technology in the LAST operation.

BACKGROUND: The LAST operation represents a good option for single left anterior descending artery (LAD) revascularization. We report our preliminary experience with the LAST operation performed with the aid of the "da Vinci" Intuitive robotic system. METHODS: From January 2000 to May 2001, 12 patients (11 males and 1 female, mean age 62 +/- 8 years) underwent the LAST operation. All patients had a proximal LAD lesion either not suitable for coronary angioplasty or unsuccessfully treated at coronary angioplasty previously. The mean preoperative ejection fraction was 55 +/- 5%. In all patients, left internal mammary artery (LIMA) harvesting was carried out endoscopically using robotic technology. After heparin administration the LIMA was distally divided to check the adequacy of the blood flow. An incision of about 6 cm was then made in the appropriate intercostal space and the LAD was exposed using a special costal retractor. Following the insertion of a temporary intracoronary shunt, the LIMA was anastomosed to the LAD. RESULTS: No hospital or delayed death occurred. Uneventful conversion to midline sternotomy was necessary in one patient who developed ischemic changes and hemodynamic instability. One patient had a revision for postoperative bleeding. All patients were discharged within the first postoperative week and in 4 of them optimal patency of the LIMA graft was angiographically documented. CONCLUSIONS: The use of robotic technology seems to overcome all the drawbacks associated with the LAST operation and enhances the role of minimally invasive surgery in coronary artery revascularization.

Minimal influence of traditional surgical risk factors on mortality in contemporary aortic valve replacement.

AIM: Transcatheter aortic valve implantation is increasingly presented as an alternative to aortic valve replacement in the high risk surgical candidate. We review the outcomes of isolated aortic valve replacement to identify contemporary results of aortic valve replacement in such high risk patients. METHODS: Retrospective analysis of 846 patients (mean age 68.7 ± 11.8 years) who underwent aortic valve replacement in a single institution from 1999 to 2008. We considered 10 risk factors as follows: female gender (395 patients, 46.7%), age, left ventricular ejection fraction, New York Heart Association Class, preoperative creatinine clearance, body mass index, peripheral vascular disease (49 patients, 5%), cerebrovascular disease (42 patients, 4.9%), chronic obstructive pulmonary disease (87 patients,10.2%), and redo surgery (53 patients, 6.2%). RESULTS: Twenty-five patients died (2.9%). Age (P=0.032; OR 1.07 per each year increase) was the only significant independent predictor of mortality. Length of stay in the hospital was correlated with age (P<0.0001), New York Heart Association Class (P<0.0001) creatinine clearance (P=0.005) and redo surgery (P=0.006). CONCLUSION: Contemporary aortic valve replacement is a low risk procedure for most patients. Historical risk factors which have been used to define high risk and inoperability, such as pulmonary disease, reoperations, decreased left ventricular ejection fraction and vascular disease, may not be relevant in the current era. This observation should be considered if such criteria are used to define patients for transcatheter aortic valve implantation.

Diagnosis and management of cerebral malperfusion phenomena during aortic dissection repair by transesophageal Doppler echocardiographic monitoring.

BACKGROUND: Early diagnosis and surgical decision making are the key for survival in acute type A aortic dissection (AAD-A). As such, transesophageal echocardiography (TEE) is widely accepted tool in the diagnosis of AAD-A. METHODS: We used TEE in 49 cases as the sole diagnostic examination of AAD-A since November 1989. It was particularly useful intraoperatively to detect cerebral malperfusion during AAD-A repair. We were able to accurately monitor the blood flow of the aortic arch by using TEE for all patients throughout the operation. Only two patients developed severe cerebral malperfusion after the distal anastomosis was finished under deep hypothermic circulatory arrest. TEE showed that the malperfusion after the bypass was re-established. In both cases the expanded false lumen blocked the true lumen. We immediately switched the perfusion cannula from the femoral artery to the ascending aortic graft to create antegrade flow. RESULTS: The subsequent TEE showed only the flow in the true lumen. One patient recovered without any complication while the other suffered mild, temporary neurological defects. Cerebral malperfusion is a potential catastrophic complication of AAD-A, which may exist before surgery or be caused by the operation itself. CONCLUSIONS: We recommend continuous intraoperative TEE to monitor aortic arch flow during these operations. This allows immediate detection of cerebral malperfusion and prompt action can be taken to prevent irreversible brain damage.

Surgical management of left ventricular free wall rupture after acute myocardial infarction.

Left ventricular rupture after acute myocardial infarction occurs more often than suspected and diagnosis is rarely made before death. Left ventricular rupture has been reported to contribute to the overall in-hospital mortality after acute myocardial infarction in up to 24% of cases and to be present in 40% of patients dying within the first week after infarction. Only prompt diagnosis and aggressive surgical treatment can be lifesaving under these circumstances. Between February 1991 and August 1993 five patients underwent emergency operation for left ventricular rupture after acute myocardial infarction using exclusively transoesophageal echocardiography as a diagnostic tool. All patients had evidence of cardiac tamponade and electrocardiography showed signs of anterolateral acute myocardial infarction in one, inferolateral acute myocardial infarction in three and lateral acute myocardial infarction in one. In two cases the infarcted area was debrided and an interrupted pledgetted 2/0 polypropylene suture was placed from inside of the ventricle outward to the epicardial surface and then through the pericardial patch. In the other three cases an original technique was used: an autologous glutaraldehyde-stiffened pericardial patch was sealed over the infarcted area using fibrin glue and fixed with running suture on the surrounding healthy myocardium. One patient died in the operating room because of low cardiac output syndrome which was possibly the result of an excessively extended area of infarction. Left ventricular rupture is a catastrophic complication of acute myocardial infarction and prompt diagnosis with transoesophageal echocardiography followed by emergency operation can be lifesaving.(ABSTRACT TRUNCATED AT 250 WORDS)