DK2985_C000 1..28 - AlSharqia Echo Club

438 Transesophageal Echocardiography(A)(C)(E)involves evaluation of valvular and subvalvular anatomyas well as measurement of the mean diastolic gradientand the search for regurgitation.TEE is also useful after mitral valve repair or replacementfor evaluation of deairing, excluding foreign materialin the cardiac cavity (see Fig. 16.17), evaluation of left andright ventricular function and exclusion of de novo valvularor aortic disease and pleural effusions. The role of TEEin mitral valvular surgery is summarized in Table 18.4.VIII.LVOTAORTICVALVEMITRAL VALVE REPAIRLVOTSAMSAMANTERIORLEAFLETPOSTERIORLEAFLETMitral valve reconstruction is the procedure of choice forMR. The issue of degenerative valve MR has beenaddressed by the pioneering work of Pr. Alain F Carpentier(B)(D)POSTERIORLEAFLET(F)POSTERIORLEAFLETFigure 18.32 A 71-year-old man undergoing mitral valverepair who developed systolic anterior motion (SAM) of themitral valve during weaning from bypass. Epiaortic 3D (A–D)and 2D views (E, F) were obtained demonstrating partial obstructionof the left ventricular outflow tract (LVOT). The longanterior mitral leaflet is seen displaced in the LVOT duringsystole. [With permission from Denault et al. (13).]who is a world leader in the development and teaching ofmodern techniques of valve repair (14). The standardizationof these techniques and the favorable long-termresults have resulted in an exponential expansion of theindications for surgery of mitral insufficiency. Thepurpose of this section is to review and describe the contemporarysurgical techniques used to correct severe MR.The initial steps of the operation are important toestablish the basis for precise reconstructive surgicaltechniques.A. Cannulation and ExtracorporealCirculation (Video Loop)After induction of general anesthesia, invasive cardiovascularmonitoring, and multiplane TEE probe insertion,the mitral valve repair is classically performed through amedian sternotomy. Mini-invasive approaches throughthe sternum or the right chest are becoming morepopular as is robotic surgery (15).The pericardium is then opened longitudinally to theright of the midline using electrocautery. Special attentionis given to the careful midline division of the thymus glandat the superior part of the anterior mediastinum. Tractionsutures are applied to the right and left superior pericardiumin order to elevate and induce a right lateral rotationof the heart. These maneuvers will later facilitate thearterial and venous cannulations and the exposure of themitral valve through the interatrial groove. Alternativeexposures of the mitral valve include the various transseptalapproaches. Systemic anticoagulation is achieved withintravenous heparin (3 mg/kg). Aortic purse-string suturesare completed on the ascending aorta (Ao) and the rightatrium (RA). The Ao is then cannulated and the pursestringsutures are tied. Venous cannulas are inserted inthe superior and inferior venae cava in order to drain thevenous return to the membrane oxygenator (see Chapter13). Double venous cannulation is preferred in order toavoid cerebral congestion due to superior venae cava distortionby the left atrial retractor that will be used for mitralvalve exposure. A combined anterograde cardioplegiacannula and vent is inserted and secured in the ascendingAo. The final step is the introduction of the retrograde cardioplegiacatheter in the coronary sinus through a stabincision in the RA. Perioperative TEE will confirm theposition of the catheter in the coronary sinus. Activatedclotting time (ACT) is monitored after heparin injection,a level of .400 s will permit the establishment of CPBat 2.2 L/m 2 , the mechanical ventilation is then stoppedand the Ao is cross-clamped followed by anterogradecold blood (4:1) cardioplegia infusion (300 cm 3 ) in theaortic root. The LA is opened with a #15 scalpel bladeand aspirated with the pump suction lines. Continuousretrograde cold blood cardioplegia is infused during the