Structural effects of an innovative surgical technique to repair heart valve defects.

The structural and functional effects of the "edge-to-edge" technique on the human mitral valve have been investigated, paying particular attention to the diastolic phase. An advanced finite element model of the valve has been developed, using a hyperelastic material schematization, suitable geometry and constraint conditions, and an effective fluidodynamic analysis. The edge-to-edge suture has been applied on this model and the diastolic phase has been simulated. The results of this calculation show that the operation increases the transvalvular pressure and the maximum stress in the leaflets, which reaches a level similar to that of the systolic phase. The influence of suture position and extension, and the mitral annulus dimension has also been investigated. The results indicate that a lateral location of the stitch is better than a central one, both regarding valve functionality (pressure level and mobility) and internal stresses level, that a longer suture worsens the valve functionality but reduces the stresses level, finally, that the dilatation of the mitral annulus does not affect the valve functionality but increases the stresses level.

"Double-orifice" technique to repair extensive mitral valve excision following acute endocarditis.

The use of conservative surgical techniques to treat mitral valve regurgitation secondary to acute endocarditis is controversial. Reconstruction of the anterior leaflet may represent an additional challenge in such a setting. We report a case of mitral valve repair where extensive excision of the anterior leaflet and related chordae tendinea was necessary because of large vegetation secondary to acute endocarditis. The "double-orifice" technique was performed and allowed the salvage of the native valve. There was no recurrent infection at 6 months from surgery, with optimal hemodynamic results.

[Repair in rheumatic mitral valve insufficiency]. / Plastica della valvola mitrale nell'insufficienza di natura reumatica.

OBJECTIVES: Emerging evidence indicates that etiology plays an essential role in the results of mitral valve repair. In this study, we examined the long-term performance of this procedure in 61 consecutive patients with pure rheumatic mitral insufficiency. PATIENTS: Patient ages ranged from 4 to 74 years (mean: 51.7 +/- 16). Preoperatively, 94% of the patients were in NYHA class II or III. RESULTS: There was no hospital mortality. According to actuarial methods 94.1% of the patients were alive 7 years postoperatively and 83.3% were reoperation free. Freedom from reoperation was significantly higher in patients who received a prosthetic ring than in those who had other types of annuloplasty (96.7% vs 59.3%; p = 0.001). As opposed to the literature, in our series there was no relationship between valve failure and age at the time of reoperation. There were only two cases of thromboembolism and one of infective endocarditis. CONCLUSIONS: This study confirms that mitral valve reconstruction in rheumatic valve insufficiency can yield satisfactory long-term clinical results, although they are less than optimum compared with those obtained in patients with degenerative disease. Favourable results depend on routine use of a prosthetic ring as well as adequate patient selection. Attention should be focused on improved detection and suppression of rheumatic activity at the time of operation.

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.

[Reparative surgery of the mitral valve in bacterial endocarditis]. / Chirurgia riparativa della mitrale nell'endocardite batterica.

INTRODUCTION: Short and long-term results of valve repair for pure mitral insufficiency resulting from native valve endocarditis are reported in 28 consecutive patients with a mean age of 55 years (range 18-74). METHODS: Six patients had acute endocarditis, with positive blood cultures in three of them. The mean time between onset of endocarditis symptoms and operation was 23 days in patients with acute endocarditis and 4.6 years in patients with healed endocarditis. Preoperatively, 87% of the patients were in NYHA class III. Indications for operation were heart failure (24 patients) and uncontrolled sepsis (4 patients). Mitral valvuloplasty was combined with other procedures in 4 patients. There was previous underlying valve pathology in 75%. RESULTS: Mitral repair was performed according to the techniques proposed by Carpentier; in 2 cases we used an original technique consisting of a double-orifice repair. Only one patient died in the hospital (operative mortality: 3.5%). By actuarial methods 96% of the patients were alive 6 years postoperatively. During the follow-up period there was no recurrence of endocarditis and no reoperation for valvular insufficiency. Ninety-three per cent of the patients were in NYHA class I or II. CONCLUSIONS: We conclude that mitral valve repair for insufficiency resulting from bacterial endocarditis is possible in acute and healed disease, has a low operative mortality and has resulted in patients free of recurrent infection. Mitral valve repair is an attractive alternate to valve replacement in bacterial endocarditis.

[Holt-Oram syndrome: cardiological, radiological and genetic evaluation]. / Sindrome di Holt-Oram: valutazione cardiologica, radiologica e genetica.

A case of a 63-year-old woman with Holt-Oram syndrome is presented. The patient, operated at 38 years for correction of an interatrial defect of the ostium secundum type presented with upper extremity skeletal abnormalities, in particular on the left, and a severe mitral insufficiency with ruptured chordae tendinae of the posterior leaflet. Mitral valve reconstruction was followed by an unusual severe hemolytic anemia and acute secondary renal insufficiency. Valve replacement was therefore necessary. At present, the patient, whose karyotype is normal, is in NYHA functional class I.

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.

Recovery of myocardial function. The ultimate target of coronary revascularization.

Recovery of myocardial contraction represents an important target of coronary revascularization and the preoperative recognition of viable akinetic (hibernating) myocardium is a crucial point of the preoperative investigation of patients with chronically depressed left ventricular function. In 14 patients dobutamine infusion during echocardiography was utilized to evoke the contractile reserve retained by viable akinetic segments. Redistribution of thallium(TI)-201 after the rest injection was also used to assess the viability of akinetic areas. The wall motion response to dobutamine infusion predicted immediate postoperative improvement in 85 of 93 segments (sensitivity 91.3%) and identified 25 of the 32 segments which did not exhibit early postoperative improvement (specificity 78.1%). Rest redistribution of TI-201 demonstrated high sensitivity (93.0%) but low specificity (43.7%) for predicting the early recovery of regional wall motion. When late recovery was also considered, the specificity of this method increased to 64.0%. Rest distribution of TI-201 identifies viability which is not necessarily associated with the early recovery of function postoperatively. When the echo-dobutamine test is positive, on the other hand, the recovery of function usually occurs immediately after revascularization and the operative risk is expected to be low even in the presence of severely compromised left ventricular function.

[Reconstructive surgery of pure mitral insufficiency. Operative results and follow-up in 128 patients]. / Chirurgia ricostruttiva nell'insufficienza mitralica pura. Risultati operatori e follow-up in 128 pazienti.

Short and long-term results of valve repair for pure mitral insufficiency are reported in 128 consecutive patients with a mean age of 49 years (range 4-75). The etiology of the mitral valve dysfunction was degenerative in 54% of the cases, rheumatic in 30%, ischemic in 9.5%, endocarditic in 6.5%. Preoperatively, 91% of the patients were in NYHA class II or III. The anatomic lesions and the mechanism of mitral regurgitation were identified preoperatively by transthoracic and/or transesophageal echocardiography. Cardiac catheterization was performed only in patients with multiple valvular dysfunction and/or with evidence of concomitant coronary artery disease. Mitral repair was performed according to the techniques proposed by Carpentier. Only one patient died in the hospital (operative mortality: 0.8%). By actuarial methods, 96% of the patients were alive 4 years postoperatively, and 84% were reoperation free. Freedom from reoperation was significantly higher in patients who received a prosthetic ring than in those who had other types of anuloplasty (96% vs 67%; p < 0.05). During the follow-up period no patient had thromboembolic episodes. Ninety-seven per cent of the 112 patients who survived the operation and were not reoperated were in NYHA class I or II. These results confirm the validity of reconstructive surgery in pure mitral insufficiency. The use of a prosthetic ring gives stability to the repair and improves long-term results.

Optimal exposure of the mitral valve through an extended vertical transeptal approach.

The mitral valve was approached through a vertical transeptal incision extended into the roof of the left atrium in 111 patients. Good exposure was invariably provided even in unfavorable situations such as a small left atrium combined with right ventricular hypertrophy or a previously implanted aortic prosthesis. The only hospital death in the entire series was not related to this approach to the mitral valve. Due to breakage of the suture in the roof of the left atrium and to incomplete reconstruction of the atrial septum resulting in a large left-to-right shunt, 2 patients required reinstitution of cardiopulmonary bypass. Both had a smooth postoperative course. Other intra- or postoperative complications related to the incision did not occur. Duration of cardiopulmonary bypass and aortic occlusion was not significantly different from that of patients operated upon through the conventional left atrial approach in the year preceding the experience embraced by this study. Only 3 of 52 patients who were preoperatively in sinus rhythm were discharged in atrial fibrillation. Enhanced atrial vulnerability was demonstrated preoperatively in all 3. These data support a wide application of the extended vertical transeptal approach in mitral valve surgery.

Sudden dilatation of right ventricle in two patients with thrombosis of a mitral Björk valve detected by echocardiography: different aspects of acute and chronic overloads of the right ventricle in these patients.

Acute thrombotic obstruction of disc valve prosthesis is a rare but catastrophic event without an immediate correct diagnosis and precocious treatment (Amman et al., 1984; Assanelli et al., 1986; Copans et al., 1980; Mann et al., 1986; Gibson et al., 1974; Johnson et al., 1973; Ledain et al., 1986). That is the main reason it is important to consider each helpful sign in order to recognize such a situation. We detected an important dilatation of the right ventricle in two patients with different stages of thrombosis of mitral Björk, the first one had also a chronic dilatation of the right ventricle due to tricuspid regurgitation. The clinical and pathophysiological aspects of these unusual situations are described in this article.

Hepato-atrial anastomosis as emergency treatment for traumatic rupture of suprahepatic inferior vena cava and hepatic veins.

The case of a 21-year-old patient operated on as an emergency for traumatic rupture of the suprahepatic inferior vena cava (IVC) and hepatic vein (HVs) is presented. Since anatomic reconstruction of the ruptured vessels was considered unfeasible, a direct anastomosis was instituted between the right atrium and the liver capsule around the disrupted IVC and HVs, using extracorporeal circulation, deep hypothermia and circulatory arrest. Hemorrhage was easily controlled and the patient survived. As far as we know, this operation, originally developed for the treatment of the Budd-Chiari syndrome, has never been used before as a life saving procedure under the circumstances described.

Arterial cannulation and myocardial protection in severe diffuse aortic calcification.

A patient with diffuse and severe aortic calcification is described. The patient had a double vessel coronary disease and it was impossible to cannulate the ascending aorta or the femoral arteries for the cardiopulmonary bypass. Arterial cannulation was performed in the innominate artery and both mammary arteries were used during a short period of ventricular fibrillation.

Anomalous origin of the right pulmonary artery from the ascending aorta: repair without cardiopulmonary bypass.

Three cases of anomalous aortic origin of the right pulmonary artery are reported. All patients presented with severe cardiac failure, two of them in the neonatal period. Clear visualization of the anomalous origin of the right pulmonary artery was obtained by cross-sectional echocardiography and the diagnosis was confirmed by cardiac catheterization. All patients underwent correction without the aid of cardiopulmonary bypass. The continuity between main and right pulmonary arteries was established by a polytetrafluoroethylene graft. One early death was due to bleeding and, probably, a pulmonary vasoconstriction crisis. In all patients the right ventricular pressure was systemic or suprasystemic before surgery and dropped to near normal in the operating room after correction. Two to five years after surgery the survivors are well. This rare, potentially lethal anomaly is amenable to correction; however, diagnosis should be followed by immediate surgical treatment.