Mitral valve replacement in patients after aortic valve replacement

BACKGROUND: Mitral valve replacement in patients who previously had undergone aortic valve replacement is a technical challenge. The rigid aortic prosthesis limits visualization of the anterior mitral annulus and placement of sutures. METHODS: Reoperative mitral valve replacement was performed in five patients after aortic valve replacement. Two patients underwent resternotomy to allow verification of normal aortic prosthetic valve function. Anterolateral right thoracotomy was used for reentry in the remaining three patients. Exposure of the anterior mitral annulus was accomplished by initial traction on the intact anterior leaflet, with resection of this leaflet only after placement of sutures. RESULTS: All patients survived the surgical procedure and are well 2 to 30 months after operation. In one patient it was impossible to open one cusp of the mitral prosthesis, nor was it possible to rotate the valve. The valve was reimplanted, but sutures were tied only after testing for full free cusp motion. CONCLUSIONS: When appropriate, right thoracotomy incision offers excellent exposure of the mitral valve with minimal dissection. Placement of sutures along the anterior portion of the annulus is facilitated by traction downwards on the anterior leaflet. Full range of motion of the prosthetic cusps should be verified before tying the sutures.     

主动脉瓣环扩大术在主动脉瓣置换术中的应用

目的 总结主动脉瓣置换术中处理小主动脉瓣环的体会.方法 我院在2000年至2010年期间收治主动脉瓣环细小的主动脉瓣病变18例,均采取改良Manouguian方法扩大主动脉瓣环,再置入较合适的机械主动脉瓣.同期行二尖瓣置换6例,室间隔修补1例,三尖瓣成形5例.结果 17例有效开口面积指数(EOAI)均达到0.85cm2/m2以上,1例0.80cm2/m2.术后严重低心排综合征1例,室性心律失常3例,心脏压塞1例.18例痊愈出院,随访1～10年,术后6个月复查发现EOAI为0.80cm2/m2的患者主动脉跨瓣压差较高,室间隔及左室壁厚度恢复较慢,左室射血分数较低;而比值在0.85～1.0之间与大于1.0的患者相比,主动脉跨瓣压差、室间隔及左室壁厚度平均值稍高,但差异无统计学意义.2例术后6年因身高、体重增加EOAI分别下降到0.79、0.81cm2/m2,出现活动后心慌,心电图提示左室高电压,经扩管等药物治疗和一般处理,症状明显改善.结论 改良Manouguian方法扩大主动脉瓣环安全、有效,可置入合适的机械主动脉瓣,有利于提高手术疗效.     

Marfan's syndrome: combined composite valve graft replacement of the aortic root and transaortic mitral valve replacement

Echocardiographic studies in patients with Marfan's syndrome indicate that 95% eventually have aortic root dilatation, mitral valve prolapse, or a combination of these. Both lesions can progress and require operation for aortic root aneurysm, aortic valve insufficiency, and mitral valve insufficiency. This report reviews the simplified treatment of 6 patients by combined composite valve graft replacement of the aortic root and transaortic mitral valve replacement at one operation. All patients survived and are well for periods extending from 1 month to 12 months.     

Mitral valve replacement with mounted aortic valve homografts

The clinical results of isolated mitral valve replacement with mounted aortic valve homografts undertaken in 29 patients is presented. In 15 of these patients haemodynamic evaluations were made before and after operation. The results attest to the haemodynamic suitability of the homograft aortic valve in the mitral position and it would appear from this initial study that there will be little difference in the durability of orthotopic and heterotopic aortic homograft valves.     

Mitral valve replacement for a severely calcified mitral annulus

We herein describe a surgical technique in a mitral valve replacement for a hemodialysis patient presenting with mitral valve stenosis and severe mitral annular calcification. Mitral annular calcification extending to the left ventricular myocardium was resected using a cavitron ultrasonic surgical aspirator (CUSA) to make a flat plane from the left atrium to the left ventricle. An autologous pericardium was secured to the posterior left ventricular wall and to the left atrial wall covering the mitral annulus for annular reconstruction. In the posterior mitral annulus, the prosthetic valve was fixed onto this pericardial patch. After the operation, the patient recovered well without any embolic complications. The prosthetic valve functions normally without any perivalvular leakage. Decalcification using the CUSA and the annular reconstruction with a pericardial patch is therefore indicated in valve replacement for patients with severe mitral annular calcification.     

Mitral valve replacement in dogs using pig aortic valve heterografts

Mitral valve replacement using pig aortic valve heterografts has been performed in 27 dogs, siting the grafts in the `atrial position'. Buffered acid formaldehyde sterilization offered the advantages that it is simple and, by de-naturing the proteins of the graft, may minimize `rejection' phenomena. It may offer some self-sterilizing property to the graft within the host post-operatively. The question whether heterograft valves will ultimately calcify remains unanswered. The aortic valve has been shown to function satisfactorily in place of the mitral valve for up to four months, producing normal haemodynamic studies. The `atrial position' of the graft has the advantage that the left ventricular cavity becomes totally available for its pumping activities. The fate of these animals depended upon developing mitral incompetence around the grafts and thrombus, leading to mitral stenosis, rather than to rejection phenomena. The operation described requires accuracy in orientating the graft. Mounting heterografts (with almost the whole of the aortic wall cut away) in a Dacron-covered metal frame pre-operatively provided a valve in a range of sizes which can be inserted in the same manner as any prosthesis in current use. Methods of sterilization and storage and the ultimate fate of heterografts in vivo require further study. Failure such as calcification will probably not develop suddenly. Such a valve could be replaced if necessary. The continued investigation and clinical use of heterografts appears to be justified when viewed against the uncertain outcome of the other methods of valve replacement.     

Aortic valve replacement for the small aortic annulus

Aortic valve surgery for the small aortic annulus is still challenging for surgeons. Recently, the new types of high performance prosthesis have been developed and the chance of an aortic root enlargement (ARE) is decreasing. In this study, we propose the ideal strategy of the aortic surgery for the small aortic annulus. We analyzed the clinical records of 158 patients who underwent aortic valve replacement from August 1999 to October 2005 in our institution. The small aortic annulus was observed in 38 patients (24%). Fourteen patients of this group underwent ARE. Patient-prosthesis mismatch (PPM) was less frequently observed in patients with ARE compared to those without ARE. The additional time required for ARE was not considerable, and neither ischemic time nor cardiopulmonary bypass time was significantly prolonged by ARE. In conclusion, we have to select a prosthesis with sufficient orifice area to avoid PPM, otherwise we should choose an option of ARE. For this consideration, we definitely need the chart that demonstrates the relationship between the nominal size of various types of prostheses and the size of a patient's annulus that those prostheses actually fit.     

Ultrasonic decalcification of the aortic annulus during aortic valve replacement

Aortic valve replacement for calcifica aortic stenosis requires meticulous debridement of the aortic annulus to effect optimal valve seating. Since 1987, we have used ultrasonic energy to debride the aortic annulus during aortic valve replacement in 56 patients. In our experience, ultrasonic debridement of the annulus is superior to traditional methods of debridement, affords improved seating of the valve, and may allow placement of a larger valve. Our follow-up ranges from 2 to 32 months (mean follow-up, 13 +/- 9 months) with 0% incidence of paravalvular leak or valve failure. We advocate the use of ultrasonic debridement as an adjunctive tool in aortic valve replacement.     

Mitral valve replacement with aortic heterografts in humans

The complications associated with the implantation of prosthetic valves and the experimental attempts to graft the mitral valve are described. Because of the disadvantages connected with the use of artificial valves and as the experimental methods of grafting the mitral valve did not prove satisfactory for clinical use, the authors developed a technique for mitral valve replacement using heterologous aortic valves—reinforced by a semirigid Teflon ring—placed above the mitral annulus inside the atrial cavity. The technique of collecting, preparing, and inserting these grafts is described in detail. Using this method, seven patients with mitral incompetence or mitral disease were operated upon between February and April, 1967. One patient died five weeks after the operation from bacterial endocarditis in a period of severe hospital infection with staphylococcus. The other six patients had a very good clinical result immediately after surgery. At the present time they are symptom-free and have normal heart sounds. Clinical and experimental data are discussed concerning the long-term fate of aortic heterografts in the mitral position.     

Long-term results for aortic valve replacement with small aortic annulus

We determined whether aortic prosthesis size influences survival and hemodynamic function. Eighty-nine patients who underwent small aortic valve replacement were followed. The small internal orifice area index (IOAI) group was defined as having an internal orifice area/body surface area ratio of < or = 1.3 cm(2)/m(2) (n = 34). The control group was defined as having an IOAI >1.3 cm(2)/m(2) (n = 55). The actuarial survival rate at 10 years was 74.5% in the small IOAI group and 75% in the control group (NS). Freedom from valve-related impairment at 10 years was 87% in the small IOAI group and 85% in the control group (NS). Postoperative pressure gradients were higher in the small IOAI group (p < 0.05). Left ventricular mass index decreased in both groups (albeit nonsignificantly in the small group, but significantly decreased in the control group). The long-term results of aortic valve replacement for patients with small aortic annulus were satisfactory. However, the postoperative pressure gradient through the prosthesis and left ventricular hypertrophy remained at a high level in the small IOAI group.     

Mitral valve repair with aortic valve replacement is superior to double valve replacement

OBJECTIVES: Double valve replacement has been advocated for patients with combined aortic and mitral valve disease. This study investigated the alternative that, when feasible, mitral valve repair with aortic valve replacement is superior. Patients and Methods: From 1975 to 1998, 813 patients underwent aortic valve replacement with either mitral valve replacement (n = 518) or mitral valve repair (n = 295). Mitral valve disease was rheumatic in 71% and degenerative in 20%. Mitral valve replacement was more common in patients with severe mitral stenosis (P =.0009), atrial fibrillation (P =.0006), and in patients receiving a mechanical aortic prosthesis (P =.0002). These differences were used for propensity-matched multivariable comparisons. Follow-up extended reliably to 16 years, mean 6.9 +/- 5.9 years. RESULTS: Hospital mortality rate was 5.4% for mitral valve repair and 7.0% for replacement (P =.4). Survivals at 5, 10, and 15 years were 79%, 63%, and 46%, respectively, after mitral valve repair versus 72%, 52%, and 34%, respectively, after replacement (P =.01). Late survival was increased by mitral valve repair rather than replacement (P =.03) in all subsets of patients, including those with severe mitral valve stenosis. After repair of nonrheumatic mitral valves, 5-, 10-, and 15-year freedom from valve replacement was 91%, 88%, and 86%, respectively; in contrast, after repair of rheumatic valves, it was 97%, 89%, and 75% at these intervals. CONCLUSIONS: In patients with double valve disease, aortic valve replacement and mitral valve repair (1) are feasible in many, (2) improve late survival rates, and (3) are the preferred strategy when mitral valve repair is possible.     

Mitral valve replacement in idiopathic hypereosinophilic syndrome

Idiopathic hypereosinophilic syndrome is an eosinophil-mediated tissue injury causing multiple organ failure. Cardiac manifestations include subendocardial fibrosis, thrombus leading to peripheral emboli, restrictive cardiomyopathy, and valvar dysfunction. This article describes a patient with the syndrome and reviews surgical experience with valve replacement and long-term prognosis.