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October 08, 2020
3 min read
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Trocar-assisted hangback an option for iridodialysis repair

The technique helps surgeons avoid imbibing corneal tissue in the suture needle.

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While performing an iris repair procedure, the surgeon needs to be cautious to not imbibe the corneal tissue in the suture needle.

Inadvertent involvement of the corneal fibers leads to non-sliding of the suture inside the anterior chamber and failure of the surgical procedure. This has been highlighted by various surgeons who perform iris repair, and instructions to overcome this have been emphasized with a word of caution.

Amar Agarwal
Amar Agarwal
Priya Narang
Priya Narang

The technique of non-appositional (hangback) repair was described by Snyder and colleagues. We present a technique of trocar-assisted hangback for iridodialysis repair that helps the surgeon to navigate skillfully through iris repair without involving the corneal fibers in the suture needle.

trocar cannula is placed at the limbus
Figure 1. A 25-gauge trocar cannula is placed at the limbus in the quadrant opposite to the iridodialysis, and the blade is withdrawn.

Source: Priya Narang, MS, and Amar Agarwal, MS, FRCS, FRCOphth
polypropylene suture needle is passed through the barrel of the trocar cannul
Figure 2. A 9-0 polypropylene suture needle is passed through the barrel of the trocar cannula.
suture needle engages the peripheral disinserted iris tissue
Figure 3. The suture needle engages the peripheral disinserted iris tissue. A 30-gauge needle is passed through the scleral side, and the suture needle is threaded into it. Eventually, the 30-gauge needle is withdrawn along with the suture.

Technique

A 25-gauge trocar is introduced from the limbal site (Figure 1), with care being taken not to touch the corneal endothelium with the tip of the trocar needle. Once the trocar is placed in position, the needle is withdrawn, and the shaft of the trocar remains in situ at the limbal site. The shaft of the trocar now acts as a lever through which a 9-0 suture needle with a long arm can be introduced for iridodialysis repair without the fear of imbibing the corneal fibers (Figure 2).

second arm of the suture needle is passed through the trocar
Figure 4. The second arm of the suture needle is passed through the trocar, and it engages the iris tissue adjacent to the previous tissue.

Initially, one arm of the suture needle is introduced through the trocar and guided inside the eye so as to engage and pass through the peripheral disinserted iris tissue (Figure 3). A 30-gauge needle is introduced from the sclera at the level of the original insertion of the iris. The suture needle is docked into the barrel of the 30-gauge needle and withdrawn from the eye. Subsequently, the second arm of the needle is passed through an area adjacent to the previous site from where the needle was passed (Figure 4), and the suture needle is withdrawn by engaging it in the 30-gauge needle (Figure 5). Both the suture ends are tied, and the knot is buried into the scleral wall (Figure 6).

30-gauge needle is again introduced through the scleral sid
Figure 5. A 30-gauge needle is again introduced through the scleral side to engage the suture needle.
Both the sutures are pulled on the scleral side
Figure 6. Both the sutures are pulled on the scleral side and tied.

Discussion

We have previously described the application of a trocar cannula for maintaining fluid infusion inside the eye. A specially designed trocar-anterior chamber maintainer can also be used for the same purpose. Placing a trocar imparts maneuverability in approximately 90° to 120° of circumference of the cornea. The trocar needs to be placed in the direction opposite to the disinserted iris tissue. In cases with massive iridodialysis, after the completion of a segmental iridodialysis, the trocar can be withdrawn and placed in another quadrant. The guided approach with trocar-assisted hangback is helpful to surgeons, and it nullifies the aspect of non-sliding of the suture due to its imbibement in the corneal fibers.