1. Chordal replacement for both minimally invasive and conventional mitral valve surgery using premeasured Gore-Tex loops 
Ulrich Otto von Oppell, PhD, Friedrich W Mohr, MD, PhD 
The Annals of Thoracic Surgery 
Volume 70, Issue 6, Pages (December 2000)
DOI: /S (00)

2. Fig 1
A ruler or measuring device measures the distance (X), between the leaflet edge and planned site of implantation of the artificial chordae on the papillary muscle, using a normal valve segment either adjacent or on the opposite leaflet to the prolapsing segment as a reference.
The Annals of Thoracic Surgery  , DOI: ( /S (00) )

3. Fig 2
A vernier calliper type device with narrow jaws is used as a template to make a Gore-Tex loop of the correct “premeasured” length (X). (A) The “premeasured” loop is secured by knotting over a felt pledget. (B) The two suture arms are then brought twice through the pledget so that the knot does not add further length to the “loop” when secured to the papillary muscle.
The Annals of Thoracic Surgery  , DOI: ( /S (00) )

4. Fig 3
The “premeasured” Gore-Tex chordal loop is secured to the papillary muscle as illustrated and tied over a second pledget. The end of the loop is then secured to the atrial side of the prolapsing leaflet segment, with a second Gore-Tex suture that is knotted on the ventricular aspect of the leaflet.
The Annals of Thoracic Surgery  , DOI: ( /S (00) )