Corneal suture marker for defining the path of a running cross-stitch suture in PK
The Homburg Cross-Stitch marker by Suffo is a corneal suture marker for precise visual marking of the suture entry and exit points of a running cross-stitch suture in penetrating keratoplasty. Highly reproducible, it creates a homogenous running cross stitch suture meaning there is less chance of need for suture repositioning.
The challenge in performing a penetrating keratoplasty (PK) is to place the sutures for donor cornea fixation in a way that no additional postoperative iatrogenic astigmatism is induced, preventing persistent vision deterioration.
One option, which proved itself throughout the history of corneal transplantation, is to fixate the corneal transplant through a running cross stitch suture – the double running crossed diagonal suture by Hoffmann with 2 x 8 bites.
As the name suggests, the challenges of this suture technique lie in the precision required to exactly place the stitches. In addition, the technique requires a precise visual estimate for gauging the dimensions, which is often associated with a shallow (long and tedious) training curve. Therefore the desired results are not always achieved.
The cross-stitch suture marker by Suffo in the shape of number 7:
Vertical visual mark (M1) of the arc and horizontal visual mark (M2) of the long side indicate the right radial alignment of the suture marker
Marking tips on both ends of the long side indicate the suture entry (B) and exit points (C)
1. Provisional fixation of the donor cornea
Use an 8-blade corneal transplant marker to place the provisional cardinal sutures with simple interrupted stitches.
2. Marking the first running suture (red dots)
For marking the needle entry and exit points of the first running suture, align the visual marks M1 and M2 with the cardinal suture,so that M2 sits at the transplantation edge (interface).
3. Repeating the markings (red dots)
Repeat this type of marking eight times along each cardinal suture.
4. Positioning the first running suture (red lines)
Perform the first running suture along the red dots in a star-shaped pattern. The dots on the donor cornea constitute the suture entry points. The dots on the recipient cornea (close to the limbus) constitute the suture exit points. The dashed lines indicate suture passage below the cornea, whereas continuous lines indicate suture passage above the cornea.
5. Marking the second running suture (green dots)
For marking the needle entry and exit points of the second running suture, the instrument needs to be placed exactly in between two cardinal sutures. Align the left end of the arc (A) with the entry point of the first running suture, and align M2 with the first running suture at the interface. Repeat this type of marking eight times along the first running suture.
6. Positioning the second running suture (green lines)
Perform the second running suture along the green dots in a star shaped pattern, as well. The dots on the donor cornea constitute the suture entry points. The dots on the recipient cornea (close to the limbus) constitute the suture exit points.
7. Removing the cardinal sutures
Remove the cardinal sutures after the double running suture is in place.
The result is a neat and evenly double running suture by Hoffmann, crossing each other at the interface.