Table 1:
Techniques for the repair of the anterior mitral leaflet
| Study | Method of anchor to papillary muscle | Method of anchor to leaflet | Method of adjusting length | Knot tying | Annuloplasty ring | Special features |
|---|---|---|---|---|---|---|
| Kasegawa et al. 1994 [18] | 1 | B1,3 | 1 | 0 | 1,2 | Tourniquets used to secure neochordae at target length during testing |
| von Oppell and Mohr 2000 [19] | 1 | A4 | 3 | 1 | 0 | Vernier callipers used to measure the PM–leaflet distance |
| Loops of neochordae are constructed to a predetermined length | ||||||
| Adams et al. 2001 [17] | 3 | B1 | 1 | 2 | 2 | Leaflet is resected prior to chordae construction |
| Duran and Pekar 2003 [28] | 1 | B2 | 4 | 1 | 1 | Temporary Alfieri stitch is used to coapt the leaflets before tying |
| Matsui et al. 2005 [21] | 1 | B3 | 3 | 0 | 2 | Specialized device measures target chordae length using surrounding normal chordae |
| Pretre et al. 2006 [16] | 0 | B2 | 1 | 0 | 1 | Requires aortotomy |
| Shudo et al. 2006 [33] | 0 | B1 | 1 | 0 | 0 | Continuous knot tying and number of knots are adjusted after knot tying |
| Rankin et al. 2006 [38] | 1 | B2 | 1 | 3 | 1 | Clip holds sutures in place over slip-knot, while competency is tested |
| The chordae is woven through the prolapsing segment, so may be particularly useful in Barlow's disease | ||||||
| Chocron 2007 [27] | 0 | B2 | 1 | 0 | 1 | Knots are tied over clips which initially hold the chordae to prevent slipping |
| Mandegar et al. 2007 [22] | 1 | A1 | 2 | 1 | 0 | A series of tight reverse knots made according to required length, which is determined by preoperative echo |
| Tied over a patch of pericardium | ||||||
| Scorsin et al. 2007 [35] | 0 | A2 | 2 | 4 | 2 | System of pre-manufactured chordae |
| Fattouch et al. 2007 [29] | 1 | B2 | 1 | 0 | 1 | Knots are tied under conditions of LV loading |
| Temporary Alfieri stitch is placed to oppose the leaflets | ||||||
| Maselli et al. 2007 [32] | 3 | B3 | 1 | 2 | 0 | Two systems of Gore-Tex sutures, one papillary and the other leaflet |
| Sutures interact and together form the neochordae | ||||||
| Smith and Stein 2008 [52] | 0 | B3 | 1 | 0 | 0 | Knots are tied leaving a little room to avoid damage to the PM |
| U-clips are used to attach the loop to the leaflet segment | ||||||
| Calafiore et al. 2008 [3] | 0 | A1 | 3 | 0 | 0 | Addition of 5 mm extra when a nerve hook is used to extend the AML that maximally avoids under-sizing the chordae |
| Rodriguez et al. 2008 [53] | 0 | A1 | 2 | 0 | 0 | No pledgets are used for the PM |
| Doi et al. 2009 [20] | 1 | A1,2 | 2,3 | 0 | 1 | Involves the construction of callipers for the measurement of the length of AML chordae |
| Brunsting et al. 2009 [43] | 1 | B2,3 | 1 | 0 | 1 | Robotic technique |
| Moorjani et al. 2009 [30] | 2 | B2 | 1 | 1 | 2 | Chordae length sets under LV loading conditions |
| Ruyra-Baliarda 2010 [36] | 0 | A1 | 1 | 0 | 1 | T-shaped no prolapse system ensures that the leaflets and annulus are at the same length |
| Cagli 2010 [34] | 1 | A2,3 | 2,3 | 3 | 1 | Hegar Dilator is used to construct the neochordae |
| Garcia-Fuster et al. 2010 [39] | 1 | B2 | 0 | 2 | 0 | Temporary stitch is used to bring the prolapsing segment to the level of the annulus, ensuring the correct chordae length is achieved |
| Maselli et al. 2010 [54] | 1 | B1 | 1 | – | – | This system involves a suture with a loop attached to the end |
| The suture contains a series of knots at a constant interval and by forming a slip noose-lace this can be adjusted | ||||||
| Maisano et al. 2011 [44] | 1 | A2,3 | 1 | 1 | 0 | A simplified device was tested in dogs to allow combination of minimally invasive, beating heart and tuneable chordae implantation |
| Chang and Kao 2011 [23] | 0 | 0 | 3 | 0 | 0 | Slit plastic tube maintains length during knot tying |
| Iida et al. 2010 [49] | 0 | 1 or 3 | 3 | 0 | 0 | A system pulls chordae to the correct tension at the site of the opposing leaflet to ensure correct length of the chordae |
| Points of tension are the leaflet and the papillary muscle | ||||||
| Matsui et al. 2011 [24] | 1 | 3 | 3 | 0 | 2 | Chordae are passed through tubes of predetermined length which are then cut after tying |
| Seeburger et al. 2012 [41] | 1 | 3 | 1 | 0 | 0 | Neochord DS 1000 device |
| Beating heart, minimally-invasive technique with custom device | ||||||
| Animal study | ||||||
| Chan et al. 2008 [25] | 1 | 1 | 0 | 2 | 0 | Clips are used to maintain the length of the chordae at the desired location, tied and cut |
PM: papillary muscle; AML: anterior mitral valve leaflet.
The table lists techniques described for the repair of the anterior mitral leaflet. Each technique is accompanied by an illustration shown in Fig. 1A–B, except Matsui et al. 2011 which is similar to Chang et al. 2011. Techniques are listed in chronological order in table and alphabetical order in Fig. 1A–B.
Method of anchor to papillary muscle: 0: not defined; 1: pledgetted support; 2: figure-of-eight conventional suture; 3: neither 0, 1, 2, e.g. fixation device. Method of anchor to leaflet: 0: not defined; A: chordae tied permanently before or without length adjustment; B: chordae are left untied or are only partially tied until competence testing; 1: at the site of anatomical chordae attachment; 2: at the site of maximal prolapse; 3: use of special device used. Method of adjusting length: 0: not defined; 1: adjusted after testing; 2: pre-determined by echo; 3: pre-determined by direct measurement (see special features if a custom device is used); 4: other. Knot tying: 0: not defined; 1: reverse knotting so that final length is not affected by tying; 2: surgeon's knot (reef knot with an extra throw); 3: slip-knots; 4: continuous suture. Annuloplasty ring: 0: not defined; 1: before chordae placement; 2: after chordae placement.