In medicine, the term cheesewiring or cheesewire effect (used interchangeably) describes any process in which cells or intercellular matrix are dissected or extruded either by the material being pressed through a taut element, or by the tension of a taut element pulling through tissue. The procedure is typically conducted in a surgical setting.
Cheesewiring or the cheesewire effect can also describe the process of suture material cutting or tearing through viscera at the time of suture anastomosis and tension.
Cheesewiring can be a complication or part of a negative outcome of a procedure. Examples include tumor growth penetrating the openings in a bowel stent that was placed to open an obstructed bowel, [1] sutures used to hold a transplanted cornea in place, [2] and treatment of tendon rupture, when sutures pull through the tendon. [3]
Evidence that the cheesewire effect has occurred is most clearly seen after surgery has been completed. Postoperatively as wound margins begin to swell, a suture can drag through the thin portion of tissue present near the surface. This suture drag is most often the result of tension being reduced in tying or placing the suture. It is apparent that cheesewiring has occurred if the suture has moved a little closer to the insertion site. A tell tale Y-shaped scar is evidence that cheesewiring has taken place. Cheesewiring that causes drag can lead to damage to tissue and make a surgeon tug on the material, leading to suture pullout. This causes an increased procedure time for the surgeon as well as a prolonged recovery period for the patient. [4]
Cheesewire complications are most often seen in cornea surgeries due to the soft tissue present in the eye. One of the most common occurrences is cheese wiring of the puncta occurring during intubation. This can occur for many different reasons. One cause is excessive tension on the tubing. Cheesewiring can also occur late as scar tissue forms around the tubing. The scar tissue fixes the tube in place and prevents the movement in the canalicular system with each blink creating problems. The tubing must be removed if cheesewiring is greater than 3 mm. [5]
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]
The term cheesewiring can also be used to name the process of using a guidewire or suture intentionally to cut through tissue during a surgical procedure or allowing a suture to slowly cut through tissue over time. Examples of cheesewiring used intentionally include treating fistulas, use in trabeculectomies, and to aid in endovascular aortic repair. [8] [9] [5]
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 (0.12 in) from the lateral edge of the future bleb site and 3–4 mm (0.12–0.16 in) 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]
Glaucoma is a group of eye diseases that result in damage to the optic nerve and cause vision loss. The most common type is open-angle glaucoma, in which the drainage angle for fluid within the eye remains open, with less common types including closed-angle glaucoma and normal-tension glaucoma. Open-angle glaucoma develops slowly over time and there is no pain. Peripheral vision may begin to decrease, followed by central vision, resulting in blindness if not treated. Closed-angle glaucoma can present gradually or suddenly. The sudden presentation may involve severe eye pain, blurred vision, mid-dilated pupil, redness of the eye, and nausea. Vision loss from glaucoma, once it has occurred, is permanent. Eyes affected by glaucoma are referred to as being glaucomatous.
A pterygium of the eye is a pinkish, roughly triangular tissue growth of the conjunctiva onto the cornea of the eye. It typically starts on the cornea near the nose. It may slowly grow but rarely grows so large that it covers the pupil and impairs vision. Often both eyes are involved.
Interventional radiology (IR) is a medical specialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs both diagnostic and therapeutic procedures through very small incisions or body orifices. Diagnostic IR procedures are those intended to help make a diagnosis or guide further medical treatment, and include image-guided biopsy of a tumor or injection of an imaging contrast agent into a hollow structure, such as a blood vessel or a duct. By contrast, therapeutic IR procedures provide direct treatment—they include catheter-based medicine delivery, medical device placement, and angioplasty of narrowed structures.
Vascular surgery is a surgical subspecialty in which vascular diseases involving the arteries, veins, or lymphatic vessels, are managed by medical therapy, minimally-invasive catheter procedures and surgical reconstruction. The specialty evolved from general and cardiovascular surgery where it refined the management of just the vessels, no longer treating the heart or other organs. Modern vascular surgery includes open surgery techniques, endovascular techniques and medical management of vascular diseases - unlike the parent specialities. The vascular surgeon is trained in the diagnosis and management of diseases affecting all parts of the vascular system excluding the coronaries and intracranial vasculature. Vascular surgeons also are called to assist other physicians to carry out surgery near vessels, or to salvage vascular injuries that include hemorrhage control, dissection, occlusion or simply for safe exposure of vascular structures.
Eye surgery, also known as ophthalmic or ocular surgery, is surgery performed on the eye or its adnexa, by an ophthalmologist. Eye surgery is synonymous with ophthalmology. The eye is a very fragile organ, and requires extreme care before, during, and after a surgical procedure to minimize or prevent further damage. An expert eye surgeon is responsible for selecting the appropriate surgical procedure for the patient, and for taking the necessary safety precautions. Mentions of eye surgery can be found in several ancient texts dating back as early as 1800 BC, with cataract treatment starting in the fifth century BC. Today it continues to be a widely practiced type of surgery, with various techniques having been developed for treating eye problems.
Refractive eye surgery is optional eye surgery used to improve the refractive state of the eye and decrease or eliminate dependency on glasses or contact lenses. This can include various methods of surgical remodeling of the cornea (keratomileusis), lens implantation or lens replacement. The most common methods today use excimer lasers to reshape the curvature of the cornea. Refractive eye surgeries are used to treat common vision disorders such as myopia, hyperopia, presbyopia and astigmatism.
Corneal transplantation, also known as corneal grafting, is a surgical procedure where a damaged or diseased cornea is replaced by donated corneal tissue. When the entire cornea is replaced it is known as penetrating keratoplasty and when only part of the cornea is replaced it is known as lamellar keratoplasty. Keratoplasty simply means surgery to the cornea. The graft is taken from a recently deceased individual with no known diseases or other factors that may affect the chance of survival of the donated tissue or the health of the recipient.
Anal fistula is a chronic abnormal communication between the epithelialised surface of the anal canal and usually the perianal skin. An anal fistula can be described as a narrow tunnel with its internal opening in the anal canal and its external opening in the skin near the anus. Anal fistulae commonly occur in people with a history of anal abscesses. They can form when anal abscesses do not heal properly.
A glaucoma valve is a medical shunt used in the treatment of glaucoma to reduce the eye's intraocular pressure (IOP).
Trabeculectomy is a surgical procedure used in the treatment of glaucoma to relieve intraocular pressure by removing part of the eye's trabecular meshwork and adjacent structures. It is the most common glaucoma surgery performed and allows drainage of aqueous humor from within the eye to underneath the conjunctiva where it is absorbed. This outpatient procedure was most commonly performed under monitored anesthesia care using a retrobulbar block or peribulbar block or a combination of topical and subtenon anesthesia. Due to the higher risks associated with bulbar blocks, topical analgesia with mild sedation is becoming more common. Rarely general anesthesia will be used, in patients with an inability to cooperate during surgery.
Glaucoma is a group of diseases affecting the optic nerve that results in vision loss and is frequently characterized by raised intraocular pressure (IOP). There are many glaucoma surgeries, and variations or combinations of those surgeries, that facilitate the escape of excess aqueous humor from the eye to lower intraocular pressure, and a few that lower IOP by decreasing the production of aqueous humor.
A pinguecula is a common type of conjunctival stromal degeneration in the eye. It appears as an elevated yellow-white plaque in the bulbar conjunctiva near the limbus. Calcification may also seen occasionally.
Pellucid marginal degeneration (PMD) is a degenerative corneal condition, often confused with keratoconus. It typically presents with painless vision loss affecting both eyes. Rarely, it may cause acute vision loss with severe pain due to perforation of the cornea. It is typically characterized by a clear, bilateral thinning (ectasia) in the inferior and peripheral region of the cornea, although some cases affect only one eye. The cause of the disease remains unclear.
A surgical suture, also known as a stitch or stitches, is a medical device used to hold body tissues together and approximate wound edges after an injury or surgery. Application generally involves using a needle with an attached length of thread. There are numerous types of suture which differ by needle shape and size as well as thread material and characteristics. Selection of surgical suture should be determined by the characteristics and location of the wound or the specific body tissues being approximated.
Pterygium refers to any wing-like triangular membrane occurring in the neck, eyes, knees, elbows, ankles or digits.
Canine glaucoma refers to a group of diseases in dogs that affect the optic nerve and involve a loss of retinal ganglion cells in a characteristic pattern. An intraocular pressure greater than 22 mmHg (2.9 kPa) is a significant risk factor for the development of glaucoma. Untreated glaucoma in dogs leads to permanent damage of the optic nerve and resultant visual field loss, which can progress to blindness.
Scleral reinforcement is a surgical procedure used to reduce or stop further macular damage caused by high myopia, which can be degenerative.
Pre Descemet's endothelial keratoplasty (PDEK) is a kind of endothelial keratoplasty, where the pre descemet's layer (PDL) along with descemet's membrane (DM) and endothelium is transplanted. Conventionally in a corneal transplantation, doctors use a whole cornea or parts of the five layers of the cornea to perform correction surgeries. In May 2013, Dr Harminder Dua discovered a sixth layer between the stroma and the descemet membrane which was named after him as the Dua's layer. In the PDEK technique, doctors take the innermost two layers of the cornea, along with the Dua's layer and graft it in the patient's eye.
In ophthalmology, glued intraocular lens or glued IOL is a surgical technique for implantation, with the use of biological glue, of a posterior chamber IOL in eyes with deficient or absent posterior capsules. A quick-acting surgical fibrin sealant derived from human blood plasma, with both hemostatic and adhesive properties, is used.
Micro-invasive glaucoma surgery (MIGS) is the latest advance in surgical treatment for glaucoma, which aims to reduce intraocular pressure by either increasing outflow of aqueous humor or reducing its production. MIGS comprises a group of surgical procedures which share common features. MIGS procedures involve a minimally invasive approach, often with small cuts or micro-incisions through the cornea that causes the least amount of trauma to surrounding scleral and conjunctival tissues. The techniques minimize tissue scarring, allowing for the possibility of traditional glaucoma procedures such as trabeculectomy or glaucoma valve implantation to be performed in the future if needed.