Surgical repair of double-orifice of the mitral valve in cases with an atrioventricular canal defects

OBJECTIVE: A Double-orifice in the mitral valve is an uncommon congenital cardiac lesion which occurs as an isolated anomaly or in association with other cardiac malformation. This report deals with our surgical experience of a double-orifice of the mitral valve in cases with an atrioventricular canal defect. PATIENTS AND METHODS: From 1991 through 1999, ten patients were diagnosed to have a double-orifice of the mitral valve at Shizuoka Children's Hospital. Each patient had associated major cardiac malformations, among which atrioventricular canal defect underwent surgical management, with five of these undergoing complete correction with or without previous pulmonary artery banding. Of these 10, the five cases were enrolled in this study. Two of these had a complete type, and the other three had a partial type. The cleft in the left-sided atrioventricular valve was closed partially in four and left untouched in one. Bridging tissue, when present, was left intact. There was no regurgitation from any accessory orifice and no repair for an accessory orifice was needed. RESULT: There was no late death and no replacement of the valve with prosthesis. During follow-up ranging from 1 to 4 years, none of the patients developed severe stenosis or progressive regurgitation in the left-sided atrioventricular valve. CONCLUSION: Meticulous surgical management of a double-orifice in the mitral valve in association with atrioventricular canal defect an achieve an acceptable midterm result without developing severe dysfunction in the left-sided atrioventricular valve.     

Further observations on the morphology of atrioventricular septal defects

Certain morphologic aspects of atrioventricular septal defects ("endocardial cushion defects," "atrioventricular canal malformations") remain controversial. It is still not clear which precise lesions should not be placed in this category. For example, is an "isolated" cleft of the mitral valve or a perimembranous inlet ventricular septal defect to be so described? It is also not fully accepted that the left atrioventricular valve in these lesions bears little resemblance to a morphologically mitral valve. We have investigated these problems by both observation and mensuration. We determined the junctional circumference of the left atrioventricular valve leaflets and the ventricular dimensions in 130 atrioventricular septal defects (95 with common valve orifice and 35 with separate right and left atrioventricular orifices); in 50 hearts with perimembranous ventricular septal defects (20 extending into the inlet septum and 30 with outlet or trabecular extensions); in seven hearts with isolated cleft of the mitral valve, and in 10 normal hearts. All specimens came from the cardiopathological collection of Children's Hospital of Pittsburgh. The measurements showed conclusively that the atrioventricular septal defects were all directly comparable irrespective of the detailed morphology of the atrioventricular valve or valves. The group of atrioventricular septal defects was totally discrete as compared with all the other specimens that had normal atrioventricular septation. The left atrioventricular valve in atrioventricular septal defects is basically a three-leaflet valve which differs from the normal mitral valve in terms of its leaflet, its chordal support, and the arrangement of its papillary muscle. Its only similarity with the normal mitral valve is that it resides in the morphologically left ventricle and guards the left atrioventricular junction.     

Unusual mitral valve abnormalities complicating surgical repair of endocardial cushion defects

A review of 155 cases of surgically repaired endocardial cushion defects revealed 16 patients (10%) with additional unusual mitral valve abnormalities that complicated the surgical procedure. Eight patients had accessory mitral valve tissue that connected the anterior and posterior leaflets to form a double-orifice valve (Group I). In four (50%), the lesion was associated with intermediate atrioventricular canal and small left ventricle; all four died following repair. In the other four, it was associated with ostium primum defect; all survived and are well. A single papillary muscle in the left ventricle was present in six patients (Group II). Two had intermediate atrioventricular canal and both died postoperatively. The other four had complete endocardial cushion defect and three are well following the operation. Perforation of the valve leaflets was present in two patients with ostium primum (Group III). Both patients are well postoperatively. Modification of the surgical technique is required to effect satisfactory repair. The bridge connecting the posterior and anterior leaflets of the mitral valve should be left undisturbed. Otherwise, severe regurgitation may result. In patients with single papillary muscle and complete atrioventricular canal, repair may be accomplished by borrowing from the tricuspid portion of the anterior leaflet, rotating that part posteriorly, and partially closing the cleft. Small perforations of the mitral leaflet do not require closure and do not result in regurgitation. Echocardiographic and angiographic delineation of these abnormalities and thorough intraoperative exploration are important in avoiding pitfalls at the time of repair.     

Rupture of the posterior wall of the left ventricle after mitral valve replacement: etiological and technical considerations

Rupture of the posterior wall of the left ventricle after mitral valve replacement, although infrequent, may be a highly lethal complication. Controversy exists regarding the etiology of this complication. Suggested causative factors include the type and extent of the valvular disease, type and size of the prosthesis, and the surgical techniques used. Our experience over a 20-year period includes 10 patients with rupture of the left ventricle following mitral valve replacement. In all patients, both mitral leaflets were excised together with the attached chordae. Three patients survived after repair of the rupture. Repair consisted of compressing the area between the left atrium and the base of the papillary muscle using two strips of Teflon and deep mattress sutures passed beneath the coronary vessels in the atrioventricular groove. Since 1983 we have routinely preserved the posterior leaflet of the mitral valve with its attached chordae to maintain a "tethered loop" between the mitral valve and ventricle. No further ruptures have occurred. The technique used for repair represents reconstitution of the divided loop between the ventricle and the mitral valve.     

Mitral valve replacement in the first year of life

From 1973 through 1987 25 patients underwent mitral valve replacement in the first year of life for mitral stenosis and mitral regurgitation. The patients with mitral stenosis included two with mitral arcade, two with supravalvular mitral stenosis with hypoplastic mitral valve, and one with parachute mitral valve. Included in the group of patients with mitral regurgitation were 12 with atrioventricular canal defect, six with chordal and leaflet defects, one with Marfan's syndrome, and one with bacterial endocarditis. Prostheses included 12 Bj?rk-Shiley (17 mm), seven St. Jude Medical (19 mm in four, 21 mm in three), five stent-mounted dura mater valves (12 mm to 16 mm), and one porcine xenograft (19 mm). In four patients the valves were placed in the left atrium in a supraannular location. There were nine operative (atrioventricular canal defect seven, mitral regurgitation two) and five late (atrioventricular canal defect four, mitral stenosis one) deaths, giving actuarial 1- and 5-year survival rates of 52% and 43%, respectively. All 6 patients with tissue valves died; the four with supraannular mitral valve replacement survived. Since 1983 operative mortality has been reduced to 0% (70% confidence limits 0% to 24%). Nine patients required a second mitral valve replacement for prosthetic stenosis 5 to 69 (mean 30) months after the original mitral valve replacement (one operative death). Because of improvements in repair of atrioventricular canal defect in infancy, the need for mitral valve replacement at atrioventricular canal defect repair has decreased. Although valvuloplasty has been advocated for repair of congenital mitral valve disease and is applicable in some infants with mitral regurgitation, mitral valve replacement is frequently unavoidable for congenital mitral disease and can now be accomplished at a low operative risk, even when the prosthesis has to be positioned supraannularly.     

完全性房室通道的外科治疗

目的总结94例完全性房室通道(com p lete atrioven tricu lar cana l defect,CAVCD)的外科治疗经验。方法一期手术矫治CAVCD 94例,房、室间隔缺损修补用双片法(涤纶片+心包片)65例,单片法29例,术中行房室瓣成形,并同期修补合并畸形。结果全组死亡10例(10.6%),其中<6个月者4例。4例术后出现二尖瓣中至大量反流,心肺功能衰竭死亡,3例因肺动脉高压危象死亡,3例分别死于低心排血量、脑并发症和气胸。随访84例,随访时间3~6个月,超声心动图复查二尖瓣轻度反流18例,轻至中度反流12例。结论严重二尖瓣关闭不全和肺动脉高压危象是CAVCD矫治术后主要的死亡原因,早期手术矫治和确切的房室瓣成形可获得较好的手术效果,术中常规使用食管超声心动图对提高手术疗效具有重要的作用。     

Surgical bypass of the systemic atrioventricular valve in children by means of a valved conduit

The surgical approach to relief of mitral stenosis in children is still a controversial problem. We describe our experience with four severely symptomatic children in whom a valved conduit from the left atrium to the left ventricle was successfully used to bypass a hypoplastic systemic atrioventricular valve. A left atrial-left ventricular extracardiac conduit was implanted in these patients with a hypoplastic mitral anulus and an adequate left ventricular chamber. There were no early or late deaths. Postoperative cardiac catheterization performed in all patients 1 month after the operation showed reduced size of the left atrium, a reduction of the left atrial-left ventricular gradient from a mean of 14 mm Hg to a mean of 5 mm Hg, and an increase of the left atrial outlet from a mean diameter of 10.7 mm to 28.7 mm (including the diameter of the native mitral valve plus the internal diameter of the valved conduit). The application of this unconventional operation in children with congenital or acquired stenosis of the systemic atrioventricular valve should be considered when the mitral valve obstruction cannot be relieved by conventional valve repair or replacement. Furthermore, the left atrial-left ventricular conduit does not preclude future alternative surgical options.     

Application of intraoperative transesophageal echocardiography in infants and small children

Intraoperative echocardiography is gaining increasing acceptance in the assessment of the surgical repair of congenital heart defects. Because of its ideal imaging location, intraoperative transesophageal echocardiography (TEE) has been especially helpful in evaluating pulmonary venous return and the integrity of the left atrioventricular valve following mitral valvuloplasty, complete atrioventricular valve repair and correction of complex congenital heart disease. It has not been routinely used in infants and small children because of a prohibitively large probe size. We report the successful use of a recently developed "pediatric" TEE probe capable of Doppler and color flow imaging in two patients less than 7 years of age. No complications were encountered. Recommendations regarding optimal probe imaging positions in infants are provided.     

Surgical treatment of double-orifice mitral valve in atrioventricular canal defects. Experience in 25 patients

Double-orifice mitral valve is an uncommon but surgically important condition. The experience in 25 cases of double-orifice mitral valve associated with atrioventricular canal defects was reviewed. This constituted 4.3% of the 581 cases of atrioventricular canal defects operated upon between 1961 and July, 1984. The combined mitral orifice area ranged from 85% to 91% of normal in those patients whose valves were sized intraoperatively. Ten associated cardiac defects were repaired in six patients. Of 23 patients having cleft mitral valve, 21 had partial closure of the cleft. There was one operative death (4.0%), which occurred early in the series in a patient in whom the tissue bridge was severed and massive mitral regurgitation resulted. In the remaining 24 patients the tissue bridge was left intact, and all survived operation. No patient had clinically significant mitral stenosis during a follow-up of 1 to 14 years (mean 4.9 years). Two patients (8%) developed progressive mitral regurgitation and required mitral valve replacement 3 and 11 years postoperatively. One of these patients died and a second death occurred suddenly 2 years following operation. All survivors are in Functional Class I or II. The noncleft orifice of a double-orifice mitral valve usually is competent and rarely requires closure. The cleft, because it constitutes a type of parachute (single papillary muscle) valve, should be closed partially so as to relieve valve incompetence without causing undue stenosis. The incidence of late development of mitral regurgitation is similar to that of atrioventricular canal without double-orifice mitral valve. Repair of atrioventricular canal associated with double-orifice mitral valve can be achieved with a low operative mortality and excellent late results.     

Ultrasonic Debridement of Mitral Calcification

A bstract Dense annular calcification to the valve attachment is particularly hazardous during mitral valve replacement because of the difficulty of placing sutures and the risk of atrioventricular rupture. We report 11 patients who underwent decalcification of the mitral anulus with the Cavitron Ultrasound Surgical Aspirator (CUSA) during mitral valve replacement. This resulted in a greatly simplified suture placement and prosthetic valve seating as well as enlargement of the annular orifice. Four other patients underwent CUSA debridement of the anterior leaflet of the mitral valve during concomitant aortic valve replacement and CUSA debridement of the aortic anulus. There were no operative deaths or major complications. Ultrasonic debridement is a useful adjunct in the surgical management of the heavily calcified mitral valve.     

Cleft mitral valve without ostium primum defect: anatomic data and surgical considerations based on 41 cases

BACKGROUND: Cleft mitral valve without an ostium primum defect, referred to as isolated cleft mitral valve, has been the subject of many reports; yet its morphology and operability remain incompletely understood. METHODS: The anatomic findings in 36 postmortem cases, five explanted hearts, and relevant clinical data constitute the material basis of this report. Cardiac catheterization data were available in 29 cases and two-dimensional echocardiograms in 13 cases. RESULTS: Twenty cases had normally related great arteries with subpulmonary conus. Of these cases 4 (20%) had tetralogy of Fallot and 1 had tricuspid atresia. Twenty-one cases had abnormal ventriculoarterial relationships with subaortic or bilateral conus resulting in transposition in 16 (76%) and double-outlet right ventricle in 5 (24%). In the cases with normally related great arteries, the morphology of the ventricular septal defect and the mitral cleft were similar to those of the more complete forms of atrioventricular canal defects. The mitral cleft usually resulted in progressive mitral regurgitation, which can be treated by surgical closure of the cleft. In the cases with abnormal conus, the morphology of the ventricular septal defect and the mitral cleft did not resemble atrioventricular canal defects. The attachment of the cleft usually produced obstruction of the left ventricular pulmonary outflow tract. Surgical repair of the cleft cannot eliminate this obstruction. CONCLUSIONS: There are two different anatomic types of isolated cleft mitral valve: the canal type, and abnormal conus type. Diagnosis of the associated ventriculoarterial relationships helps to guide their surgical treatment.     

Mitral valve surgery--a Scandinavian perspective

During the last three decades, the most prevalent surgical mitral valve disease in Scandinavia has changed from the sequelae of rheumatic fever to the mitral valve pathologies related to ischemic heart disease. Also, the total number of patients in need of a mitral valve procedure is increasing. For several of the patients with ischemic mitral valve disease, the natural prognosis of their disease is dismal. However, there are several uncertainties as to whether or not a surgical procedure can improve the life expectancies of these patients. Also, the procedures of choice for patients with ischemia related "functional mitral valve disease" is a long standing controversy. In this issue of "Scandinavian Cardiovascular Journal" we present the rationale and protocol for the "MoMIC" trial, a randomized multicenter study aiming to clarify whether revascularization alone or a combined revascularization and mitral valve annuloplasty is the treatment of choice for patients with ischemia related moderate mitral regurgitation.     

无支架二尖瓣制备、保存和体外三尖瓣置换技术探讨

目的观察深低温保存猪二尖瓣超微结构,探索无支架二尖瓣制作方法和置换三尖瓣技术。方法采用猪二尖瓣制成无支架瓣膜,抗生素灭菌深低温保存,透射电子显微镜观察深低温保存１个月的猪二尖瓣组织结构。将离体猪心三尖瓣切除,将无支架猪二尖瓣前瓣环缝合于隔瓣环,二尖瓣后瓣环缝合于三尖瓣前后瓣环,两乳头肌缝合于右心室前壁,完成无支架二尖瓣置换三尖瓣,注水试验观察瓣膜启闭功能。结果透射电子显微镜观察到,深低温保存猪二尖瓣内皮细胞结构完整,胶原纤维结构致密,排列整齐,成纤维细胞胞膜完整,细胞核无固缩现象,线粒体无明显肿胀。无支架二尖瓣置换的离体猪心三尖瓣启闭功能良好。结论深低温保存的无支架猪二尖瓣结构完整,活性得到很好保持。瓣膜设计合理,用此瓣膜置换三尖瓣技术可行     

Diagnosis and management of the double orifice mitral valve: three case reports

Double orifice mitral valve (DOMV) is an uncommon congenital heart defect. The isolated occurrence of this anomaly is very rare and, more often, is associated with another congenital malformation, dominated by atrioventricular canal defects (AVCD). Mitral insufficiency and/or stenosis may complicate this malformation. Treatment may be summarized as abstention, surgical valve repair, or valve replacement. In here, we report three cases with DOMV. The first patient was an 18-month-old boy who was operated for severe mitral valve stenosis and mild insufficiency (in 1980s), the second was a 47-year-old female, who was operated recently for mitral valve replacement (MVR) under cardiopulmonary bypass due to severe mitral valve insufficiency. This patient had been operated due to the secundum-type atrial septal defect in our institution previously. The last one, a 3-year-old boy, with DOMV and three papillary muscles, was on clinical follow-up because he had no symptoms.     

Extended vertical transatrial septal approach to the mitral valve

Optimal mitral valve operation requires adequate exposure without impairment of atrial physiology, namely sinus node and atrioventricular node function. We used an extended vertical transseptal atrial approach in 34 consecutive patients. The extended vertical transseptal approach combines two semicircular atrial incisions circumscribing the tricuspid and mitral annuli anteriorly and superiorly, allowing exposure of the mitral valve by deflecting the ventricular side using stay sutures. The right atrium is opened anteriorly along the atrioventricular sulcus. The atrial septum is incised vertically through the fossa ovalis. The right atriotomy is extended superiorly in the right coronary fossa between the right atrial appendage and the atrioventricular sulcus to meet the septal incision. The two joint incisions are extended onto the left atrial roof transversely. At this point, the two semicircular incisions are performed and joined, and mitral valve operation is performed. There were 18 women and 16 men. Five patients had ischemic mitral valve regurgitation, 18 had mitral valve prolapse, and 11 had rheumatic heart disease. The mitral valve was replaced in 17 patients and repaired in 17. There were no perioperative complications associated with the atriotomies, ie, no bleeding, no atrioventricular nodal dysfunction, and no sinus node dysfunction. The extended vertical transatrial septal approach provides good mitral valve exposure without inherent complications.     

Surgical repair of tetralogy of Fallot with complete atrioventricular canal

Total repair of tetralogy of Fallot and complete atrioventricular canal remains a surgical challenge; however, good results can be obtained if the lesions are repaired properly at operation. Our technique involves a combined right atrial and right ventricular approach with closure of the ventricular septal defect through the ventriculotomy, double-patch closure of the septal defects without dividing the bridging atrioventricular leaflets, and functional repair of the newly constructed mitral valve.     

New technique for enlargement of the pulmonary outflow tract in corrected transposition of the great arteries [SLL]--a report of 2 cases

New technique for enlargement of the pulmonary outflow tract was performed in two patients with corrected transposition of the great arteries [SLL] associated with atrial septal defect, ventricular septal defect, pulmonary stenosis and mitral regurgitation. The middle of the anterior leaflet of the mitral valve was incised to the valve annulus towards the mid-point of the mitral-pulmonary fibrous continuity. In this approach, anterior node and anterior atrioventricular conduction bundle were securely protected from the surgical incision. The pulmonary annulus was divided posterolaterally and the incision was further extended into the pulmonary trunk to the bifurcation. The pulmonary trunk was enlarged with a fusiform patch of the xenogenous pericardium bearing monocusp. In case 1, St. Jude Medical valve #31 was implanted in the mitral position. In case 2, mitral valvular annuloplasty with Carpentier ring #36 which was deformed to admit enlarged portion of the pulmonary trunk. The VSD was closed through the right atrium, placing the suture on the left side of the septum. However, complete A-V block ensured temporarily due to retraction at the operation in case 1. No conduction disturbance ensured in case 2. This technique can provide some advantage in avoidance of injuries to the anterior node and the anterior atrioventricular conduction bundle. Application of this technique to the corrected transposition of the great arteries without mitral regurgitation is to be further evaluated.     

Left ventricular-right atrial communication following mitral valve replacement

A case of an acquired left ventricular-right atrial communication complicating Omnicarbon replacement of a severe calcified mitral valve in the area of the posteromedial commissure is reported. The intricate relationships of the membranous atrioventricular septum to the mitral valve and the tricuspid valve predispose to the creation of an iatrogenic left ventricular-right atrial fistula when aggressive debridement of extensive valvular calcification is performed. Emphasis is placed on the diagnosis, and immediate surgical repair is advocated as soon as this complication is discovered.     

66例部分性房室管畸形的外科治疗

目的总结部分性房室管畸形手术治疗的经验,以提高治疗效果。方法回顾性分析我院1984年1月－2007年12月经外科治疗部分性房室管畸形患者66例的临床资料,对二尖瓣大瓣裂的处理：单纯裂缺缝合52例,缝合加交界折叠缝缩8例,加小瓣成形1例,加缝置St．Jude软质人工成形环3例,人工机械瓣置换术2例;对原发孔型房间隔缺损的修补：采用涤纶补片修补12例,自体心包54例;采用Kirklin法将冠状静脉窦口隔入左心房5例,MeGoon法将冠状静脉窦口隔入右心房61例;同期处理其他合并畸形。结果术后早期死亡2例（3．03％）,1例死于心律失常,另1例死于呼吸功能衰竭。术后发生Ⅲ°房室传导阻滞2例,均安装永久性心脏起搏器。术后随访52例（81．3％）,随访时间5个月～22年,平均15年,心功能均有明显改善,尤其是术前心功能Ⅲ～Ⅳ级的19例患者,术后改善为Ⅰ～Ⅱ级。再次手术4例,其中1例经再次行二尖瓣置换术治愈;术后死亡3例,1例死于急性。肾功能衰竭,2例死于低心排血量综合征。结论早期手术治疗可以保全房室瓣结构、功能,避免发生肺动脉高压和降低死亡率。手术治疗的关键是消除二尖瓣关闭不全、修补原发孔型房间隔缺损和避免损伤传导组织,术后近、中期疗效良好;有残留中度以上二尖瓣反流者,远期效果不满意。     

Management of Systemic Atrioventricular Valve Regurgitation in Infants and Children

A bstract Since September 1979, 53 patients have required operation for systemic atrioven-tricular valve regurgitation at Children's Hospital and Health Center of San Diego. (Primary repairs of atrioventricular canal defects are excluded from this report.) Diagnoses include single ventricle, cardiomyopathy, congenital mitral insufficiency, Marfart's disease, rheumatic heart disease, and a history of prior repair of atrioventricular canal defect. Ages ranged from 4 months to 19 years; median age is 5 years. In 31 patients, the atrioventricular valve could be repaired. In 24 patients, the valve was replaced (including two patients previously repaired). There were four operative deaths, all in the valve replacement group: three following valve replacement, and one following emergency thrombectomy. Two early failures in the repair group required valve replacement. Techniques for repair included leaflet resection, commissural annuloplasty, ring annuloplasty, and chordal shortening. Follow-up reveals good-to-excellent status in 38 patients. There were seven late deaths: six following valve replacement (one death valve related). Current surgical technique permits repair of the systemic atrioventricular valve in many infants and children requiring operation for regurgitation. The long-term results of valve repair are good to excellent. Repair avoids the morbidity and mortality of valve replacement, e.g., anticoagulation, fixed orifice size, and catastrophic mechanical valve malfunction. ( J Card Surg 1993; 8:612–621 )