Cheesewiring

Whether intentional or non-intentionally occurring, a cheesewire suture can be removed in surgery. A cheesewire suture is removed by a small incision made in the conjunctiva overlying the two ends of the suture. Fine removal suture forceps are used to grasp both ends of the suture. Tangential traction is then used to cheesewire through the scar tissue [5]

There are many complications that can arise from the removal of the cheesewire suture. In the eye specifically, suture breaking can result in significant tissue scarring. This results in a large amount of traction force required to remove the suture. Occular Hypotony and hypheama following the removal of cheesewire sutures are also common occurrences [5]

Surgeons can take several precautions to help decrease the probability of cheesewiring occurring. One technique determined to decrease suture drag is placement of the needle perpendicularly through the entire corneal thickness encompassed by the suture bite on each side of the incision. Certain sutures are also more prone to cheesewiring. 3-0 Vicryl is one of the least likely sutures to experience cheesewiring. Sutures may also be coated in materials to reduce tissue drag. Monofilament sutures create less drag while passing through tissue, but may decrease tensile strength and cause crimping. Therefore, multifilament sutures are more commonly used to prevent the occurrence of cheesewiring despite a decrease in mechanical properties [6]

Factors such as the type and size of the needle, suture type and thickness, and suture placement should all be considered as all factors have a significant effect on the surgical result. For instance, having a suture that is too short can lead to inflammation in tissue, while a suture that is too tight can cause necrosis, especially in association with significant edema [7]

Treatment of fistulas often involves placing a suture and allowing it to cut off the fistula over time [9]

Cheesewiring is used as an intentional procedure in a trabeculectomy. In a trabecuectomy, a loop of 8-0 nylon sutures is placed under the scleral flap. The cheesewiring suture allows rescuing failing or failed bleb, by mechanically breaking down the subscleral flap.[5]

In this procedure, a triangular partial thickness scleral flap is created using a diamond knife. The scleral flap is then extended to the limbus that is hinged anteriorly. A sclerotomy is then made with a punch followed by a peripheral iridectomy. An 8-0 nylon suture is then passed through the conjunctiva from the external aspect into the subconjunctival space. This process creates the cheesewiring effect. The needle is entered 3 mm from the lateral edge of the future bleb site and 3-4 mm away from the limbus. The 8-0 nylon suture is taken under the scleral flap. Once this happens, the suture is reversed and the needle is passed through the conjunctiva from the inside towards the outside position. A singular 10-0 vicryl suture can secure the scleral flap and then the cheesewire suture can then be cut flush to the conjunctiva. The conjunctiva flap can be then secured with 26 10-0 vicryl sutures at either end of the limbus. A single 10-0 vicryl mattress suture can be placed in the middle. This entire process allows for blebs to be rescued.[5]

Cheesewiring is commonly used in the endovascular repair. The cheesewire technique can be used to fenestrate an intimal flap, alleviating malperfusion in aortic dissection. Pulling both ends of a guide wire in a caudally sawing motion down through the infrarenal neck and into the aneurysm sac completes the technique. This process shears the flap with minimal damage. [8]