The most common MV pathology requiring surgical intervention is mitral regurgitation (MR) due to leaflet prolapse. Figure 4.2a–d shows 3D images of a MV from a patient with P₂ leaflet prolapse. As demonstrated in these images, there is prolapse throughout the valve; however, the majority of the prolapse occurs in the P₂ region. This is evident from the 3D MV model and is consistent with an anterior directed MV regurgitant jet, which originated from the P₂ region (Fig. 4.2d). This valve was repaired with P₁-P₂ and P₂-P₃ cleft (indentation) closures, along with a “haircut” resection of P₂ (radial excision of the P₂ tip) with reattachment of the remaining P₂ chords to the P₂ leaflet leading edge. A 36 mm Cosgrove Flexible Annuloplasty Band (Edwards Lifesciences, Irvine, Calif.) was then implanted (Fig. 4.2e). Imaging of a MV from a patient with a P₃ prolapse is shown in Fig. 4.3. In this case, the P₃ prolapse is identified easily both in the acquired image (Fig. 4.3a) and the 3D MV model (Fig. 4.3b). This valve was repaired with a P₃ commissuroplasty and implantation of a 37 mm ATS Simulus Flexible Annuloplasty band (Medtronic, Minneapolis, MN) (Fig. 4.3c).

Figure 4.4 illustrates a patient requiring an anterior MV leaflet repair. This patient had prolapse of the A₃ segment, which is demonstrated in both the acquired image (Fig. 4.4a) and the mitral valve model (Fig. 4.4b). This valve was repaired with an A₂ to A₃ chord transfer and insertion of a 35 mm ATS Simulus Flexible Annuloplasty Band (Fig. 4.4c). Multiple prolapsing MV segments can be seen in Fig. 4.5a–c. The entire posterior leaflet appears both to billow (leaflet body) and prolapse (coapting edge). In addition, anterior leaflet segments A₁ and A₂ appear to prolapse. Figure 4.5d shows a large central jet and at least one other jet originating from the anterolateral commissure. This valve was repaired successfully with a P₂ “haircut” procedure, a P₃ quadrangular resection, P₁-P₂ and P₂-P₃ cleft closures, and insertion of 31 mm ATS Simulus Annuloplasty Band (Fig. 4.5e).

One of the most complex types of mitral pathology to repair is the myxomatous bi-leaflet prolapsing valve associated with Barlow’s disease. This type of degenerative valve is characterized by excessive leaflet tissue with myxoid appearance and leaflet billowing, leading eventually to the development of excessive chordal elongation and severe bileaflet prolapse. Today, we see various stages of this type of degeneration with some valves having all segments prolapsing above the annular plane. Images obtained from RT-3D-TEE allow accurate identification of severely diseased areas responsible for regurgitation in these patients. For example, images taken from a patient with a typical Barlow’s type valve are shown in Fig. 4.6a–d. These images demonstrate clearly that the most severe prolapse occurs in the area of P₂ with two associated regurgitant jets. One jet is directed posteriorly and the other is directed anteriorly (Fig. 4.6d). This valve was repaired with a triangular resection of P₂ and placement of a 36 mm Cosgrove Flexible Annuloplasty Band (Fig. 4.6e). Often small levels of prolapse may not need direct surgical intervention, as the annuloplasty will reduce 1–3 mm of anterior leaflet prolapse to coapt sufficiently with the posterior leaflet.

It is important to distinguish a flail MV leaflet from a prolapsing one. This is done routinely by 2D-TEE; however, flail leaflets become even more apparent and detailed with 3D-TEE. Figure 4.7a shows a MV with two ruptured cords in the P₂ -P₃ region. This valve was repaired with a P₂ triangular resection and a 35 mm ATS Simulus Flexible Annuloplasty Band (Fig. 4.7b). The MV from another patient with a P₂ flail leaflet is shown in Fig. 4.7c. This patient had one ruptured cord and much more posterior leaflet redundant tissue, necessitating a more complex repair. This valve was repaired successfully with a trapezoidal P₂ resection, imbrication of P₂ chords to give full support across the leading edge of P₂, a P₁-P₂ cleft closure, a secondary chord transfer to the leading edge of A₂, and placement of a 37 mm ATS Simulus Flexible Annuloplasty Band (Fig. 4.7d). Finally, Fig. 4.7e shows an A₁ MV flail segment. This valve could not be sucessfully and was replaced.

Ischemic MR often represents a challenge to recognize, characterize, and repair, particularly in patients receiving concomitant coronary artery bypass grafting. Classic restrictive ischemic MR (Type IIIb) results from lateral displacement of the papillary/chordal complex during systole with resultant P₃ tethering and asymmetric annular dilatation. This results in a posterior directed regurgitant jet and is associated with left ventricular wall motion abnormalities. A mitral valve from a patient with type IIIb ischemic MR and a characteristic posteriorly directed regurgitant jet is illustrated in Fig. 4.8. The MV in this patient was repaired with the placement of a 34 mm ATS Semi Rigid Full Annuloplasty Ring (Fig. 4.8e). Conversely, Fig. 4.9a–d shows an example of central ischemic MR, which is associated with global ischemia and concomitant ventricular dilatation. The 3D MV model is particularly useful in this case as it demonstrates how the anterior and posterior tethered leaflets are distracted down and apart with reference to the annular plane (Fig. 4.9b). In this case tethering resulted from lateral displacement of both papillary muscles with systole. Images obtained with color full volume imaging show the classic central regurgitant jet (Fig. 4.9d). Repair of this valve was accomplished with a 30 mm Carpentier Edwards Physio Rigid Annuloplasty Ring (Edwards Lifesciences Corporation, Irvine, CA).