Tutorial

Loop technique for mitral valve repair

Published: January 1, 2010
DOI: 10.1510/mmcts.2010.004523
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The loop technique facilitates mitral valve repair for leaflet prolapse by implantation of Gore-Tex neo-chordae. The key feature of the technique is a pre-made bundle of four loops made out of one suture. The loops are available in different lengths ranging from 10 to 26 mm. After assessment of the ideal length of neo-chordae with a caliper the loops are then secured to the body of the papillary muscle over an additional felt pledget. The free ends of the loops are then distributed along the free margin of the prolapsing segment using one additional suture for each loop.

Leaflet prolapse is commonly seen in degenerative mitral valve (MV) disease. The state-of-the-art treatment for degenerative disease is surgical MV repair. Among several repair techniques chordal replacement using polytetrafluoroethylene (PTFE) sutures was introduced into clinical practise by Frater et al . The concept of chordae replacement has been shown to be highly versatile, and to achieve excellent short- and long-term results . Several different methods of chordal replacement have been described since 2000, among them, the so-called loop technique . This technique uses a set of four premade loops of several lengths between 10 and 26 mm. The loops are anchored to the papillary muscle and then used to re-suspend the prolapsing segment of the leaflet. The technique was initially introduced to facilitate anterior mitral leaflet prolapse but over time has proven effective also for posterior leaflet prolapse . This tutorial presents the procedure in the context of a clinical case of prolapse of the posterior leaflet in the P2 segment.

One set of loops consists of one 4-0 CV PTFE suture (Gore Assoc., Flagstaff, AZ, USA) and two rigid felt pledgets with two premade suture holes in each pledget (Photo 1). When preparing the loops the suture is repeatedly tied and secured with knots over the first felt pledget, after circling four individual loops over a caliper at the determined length. This usually needs to be done intraoperatively on the table during surgery; however, since 2010 MV repair loops are also commercially available (Santech Medical, Grosswallstadt, Germany).

Photo 1. A so-called Leipzig loop for chordae replacement in mitral valve repair.
Photo 1: A so-called Leipzig loop for chordae replacement in mitral valve repair.

Standard echocardiographic and intraoperative valve analysis shows a large prolapse of the P2 segment due to ruptured chordae tendinae, an ideal pathology for repair using the loop technique (Videos 1 and 2). The repair strategy in this case consists of the loop technique in combination with a standard annuloplasty.

For assessment of the length of neo-chordae a custom-made caliper (Geister Medizintechnik GmbH, Tuttlingen, Germany) is introduced (Photo 2). The bottom end of the caliper is positioned at the body of the papillary muscle, reasonably below the tip (4–6 mm). The adjustable top end of the caliper is positioned at the height of the corresponding leaflet margin (Video 13). The measured distance reflecting the ideal length of neo-chordae is then indicated on the handle of the caliper.

Photo 2. The custom-made caliper for assessing the distance between the papillary muscle and the prolapsing segment of the leaflet.
Photo 2: The custom-made caliper for assessing the distance between the papillary muscle and the prolapsing segment of the leaflet.

After assessment of the designated length of neo-chordae the respective set of loops is secured to the body of the papillary muscle, taking a ‘sufficient’ bite of muscle tissue at least 4 to 6 mm below the tip of the papillary muscle (Video 4). For secure anchoring both free ends of the loops are passed through the muscle and through the premade holes of the second felt pledget and are finally secured with knots (Video 5). Regarding the correct positioning of neo-chordae on the papillary muscle, it is helpful when the four single loops arise from the portion of the papillary that is considered to be physiologic – mostly the portion that faces towards the prolapsing segment of the leaflet.

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    1 - Severe mitral regurgitation (0:00)

    Severe mitral regurgitation. (With voice over.) Preoperative transesophageal echocardiography (TEE) shows a large prolapse of the P2 segment, causing significant mitral regurgitation (MR). The prolapse is in two-chamber view with and without color Doppler as well as in the commissural view. The ruptured chordae tendinae with the subsequent prolapse are clearly visible in all sequences, especially in 3D.

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    2 - Valve analysis (1:06)

    Valve analysis. Intraoperative valve analysis confirms the pathology of a prolapsing P2 segment due to ruptured chordae tendinae.

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    3 - Assessment of loop length (1:37)

    To identify suitable neo-chordae a custom-made caliper is introduced to measure the distance between the body of the papillary muscle and the prolapsing leaflet segment.

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    4 - Implantation of loops (1:54)

    The bundle of loops is secured to the body of the papillary body, taking a reasonable bite of muscle with the two ends of the loop.

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    5 - Anchoring the loops (2:41)

    Both free ends of the bundle of loops are then tied together over the second felt pledget to achieve a secure and durable fixation.

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    6 - Leaflet resuspension (2:55)

    Four additional sutures are used to re-suspend the prolapsing segment of the leaflet.

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    7 - Leaflet fixation (3:28)

    All additional sutures are securely tied and cut to complete the loop technique on the leaflet.

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    8 - Operative result (3:41)

    The water test for analysis of MV repair with a combination of the loop technique and annuloplasty shows complete resuspension of the leaflet with no residual MR.

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    9 - Competent post-repair valve (3:50)

    The final echocardiographic examination shows no more prolapsing segment and no evidence of MR (two-chambers and commissural view).

A total of 2798 minimally invasive MV operations were performed at our centre between 1999 and 2009 with an overall repair rate of 81.4% (2278). Of those patients who underwent MV repair a total of 955 patients (43.7%) were operated using the loop technique. Within this cohort, the primary pathologies being treated was posterior leaflet prolapse. However, the loop technique has also been used for the anterior leaflet. Most frequently the loop technique was used to re-suspend the P2 segment in a total of 765 (33.6% of all MV repair patients) patients. The mean number of loops attached to the P2 segment was 3.3∓1 with a mean length of 13.7∓ 2.9 mm.

Comment
There is a large armamentarium of different MV repair techniques available . Chordal replacement, however, has been used with increasing frequency and in some centers is now preferred over the classical technique of leaflet resection with or without sliding plasty

The main advantages of the loop technique are as follows: The rationale of the technique is to imitate native valve anatomy and restore native leaflet function . It preserves native valve tissue, following the ‘respect not resect’ approach . Creation of a large mitral orifice area as well as a long coaptation length is possible . It achieves a high freedom-from-reoperation rate of 98.7% at five years for mitral regurgitation due to isolated posterior prolapse . It is a highly standardized and thus a highly reproducible procedure

Due to its distinct simplicity, high reproducibility, standardization, and high versatility the loop technique can be applied for nearly any prolapsing segmen,t ranging from a ‘simple’ P2 prolapse to a complex commissural bileaflet prolapse . Furthermore, it is easy to learn and may well increase a surgeon’s repair rate. In conclusion, the loop technique is a simple but highly efficient and very versatile MV repair technique.

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    PubMed Abstract
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    PubMed Abstract
  3. David TE, Ivanov J, Armstrong S, Christie D, Rakowski H. A comparison of outcomes of mitral valve repair for degenerative disease with posterior, anterior, and bileaflet prolapse. J Thorac Cardiovasc Surg 2005;130:1242–1249.
    PubMed Abstract | Publisher Full Text
  4. Perier P, Hohenberger W, Lakew F, Batz G, Urbanski P, Zacher M, et al. Toward a new paradigm for the reconstruction of posterior leaflet prolapse: mid-term results of the ‘respect rather than resect’ approach. Ann Thorac Surg 2008;86:718–725.
    PubMed Abstract | Publisher Full Text
  5. Seeburger J, Falk V, Borger MA, Passage J, Walther T, Doll N, et al. Chordae replacement versus resection for repair of isolated posterior mitral leaflet prolapse: À ègalité. Ann Thorac Surg 2009;87:1715–1720.
    PubMed Abstract | Publisher Full Text
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    PubMed Abstract
  7. Falk V, Seeburger J, Czesla M, Borger MA, Willige J, Kuntze T, et al. How does the use of polytetrafluoroethylene neochordae for posterior mitral valve prolapse (loop technique) compare with leaflet resection? A prospective randomized trial. J Thorac Cardiovasc Surg 2008;136:1200–1206.
    PubMed Abstract | Publisher Full Text
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    PubMed Abstract | Publisher Full Text
  9. Seeburger J, Borger MA, Doll N, Walther T, Passage J, Falk V, et al. Comparison of outcomes of minimally invasive mitral valve surgery for posterior, anterior, and bileaflet prolapse. Eur J Cardiothorac Surg 2009;36:532–538.
    PubMed Abstract | EJCTS Full Text
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    PubMed Abstract

This tutorial was originally published by EACTS with Oxford University Press and has been adapted to fit our new MMCTS templates.

Authors
Joerg Seeburger, Thilo Noack, Michael Winkfein, Joerg Ender, and Friedrich Wilhelm Mohr

Author Affiliation
Heart Center, Leipzig University, Struempelstrasse 39, 04289 Leipzig, Germany

Corresponding author

Joerg Seeburger
Heart Center, Leipzig University, Struempelstrasse 39, 04289 Leipzig, Germany

Phone: +49-341-8651421
Fax: +49-341-8651452
Email: seej@med.uni-leipzig.de

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