Ординатура / Офтальмология / Английские материалы / Glaucoma Surgery_Trope_2005

13.Melamed S, Ashkenazi I, Glovinski J, Blumenthal M. Tight scleral flap trabeculectomy with post operative laser suture lysis. Am J Ophthalmol 1990; 109:303 309.

14.Jampel HD, Pasquale LR, Dibernado C. Hypotony maculopathy following trabeculectomy with mitomycin C. Arch Ophthalmol 1992; 110:1049 1050.

15.Savage JA, Condon GP, Lytle RA, Simmons RJ. Laser suture lysis after trabeculectomy. Ophthalmology 1998; 95:1631 1638.

3.METHODS

Two techniques are used to perform suture after operative adjustment of the trabeculectomy flaps (1 5).

1.The scleral flap is tightly sutured and the sutures lysed with an argon laser (see elsewhere in this book).

2.The scleral flap is sutured utilizing a slipknot on the 10/0 nylon suture, leaving the long end accessible on the corneal surface, so that it can be grasped and removed, thereby releasing the flap.

4.TECHNIQUES

4.1.Releasable U-Suture—Rootman Technique (3)

1.Trabeculectomy with a rectangular 4 3.5 mm flap is performed, as described elsewhere in this book.

2.A 10/0 double-armed suture is passed radially from anterior to posterior, partial thickness through the cornea at the limbus near the temporal edge of the scleral flap.

3.The suture exits the cornea at the limbal base of scleral flap just in front to the former attachment of the conjunctiva (Fig. 17.1).

4.The next bite is taken through the scleral flap at the posterior temporal corner, and then passed through the temporal sclera on the posterior edge of the flap bed (Fig. 17.1).

5.The other needle of the double-armed suture is placed in a similar fashion through the cornea and the limbus to the base of the scleral flap at the opposite nasal edge of the scleral flap.

6.The suture is passed through the scleral flap on its posterior-nasal corner, and then passed through the base of the sclera bed.

Figure 17.1 Releasable U suture. A double slipknot is placed, which is released by pulling the corneal loop (see arrow). [Reprinted with permission, from Ref. (3), Slack Inc.]

3.A full thickness bite is then taken through the posterior lip of the scleral flap, followed by a bite through the sclera, at 458 to the radial edge of the flap [Fig. 17.2(a)].

4.The suture is tied using three loops, grasping the loop of the suture that is protruding at the corner of the scleral flap [Fig. 17.2(a) and (b)]. The suture is released by uncovering the anterior intra-corneal loop (between 1 and 2) and pulling the suture out. The slipknot will untie and release the scleral flap.

4.3.Releasable Suture According to Cohen and Osher’s Method (1)

1.Flap suture: A nylon 10/0 suture is passed toward the limbus from posterior to anterior and through the sclera posterior to the border of the base of the scleral flap, and exits just before the edge of the scleral dissection.

2.The needle is then passed through the scleral flap from the undersurface through to the anterior surface.

3.The suture is then passed partial thickness through the limbus and exits through peripheral clear cornea. The suture is passed in a radial direction. The corneal end of the suture is left long (Fig. 17.3).

4.The end of the suture that secures the scleral bed to the dissected flap is then tied with three throws.

5.The second throw is then tied as a bow rather than as a square knot, so the entire knot becomes a bowtie like slipknot.

6.The position of the slipknot is checked, tension on the corneal side of the knot should cause the slipknot to undo.

7.A second such suture is inserted at the other side of the flap. The flap edge parallel to the limbus is secured with a regular nonreleasable 10/0 nylon interrupted suture.

To release the suture, the free corneal end of the suture is pulled to release the knot as indicated in the postoperative period. Should the IOP be acceptable, then the releasable suture is released after 2 3 weeks, when the fistula is considered more healed. Longer time may be advisable if antimetabolites have been used.

Figure 17.3 Releasable sutures according to Cohen’s method. The end of the suture is left free on the corneal surface.

4.4.Kolker’s Modification (2)

1.The corneal end of the suture is passed superficially through the peripheral cornea, parallel to the limbus similar to the method of Cohen.

2.The suture is cut flush with the cornea following the placement of the posterior end of the suture and releasable knot, at the exit site on the cornea. This leaves an intra-corneal loop without an irritating suture end that can later be grasped to release posteriorly the bowtie knot that is anchoring the flap (Fig. 17.4).

4.5.Johnstone’s Technique (5) (X-Shaped Pattern)

1.This technique utilizes a limbus based conjunctival flap.

2.A 10/0 nylon suture is passed in a double-armed fashion through the posterior edge of the scleral flap in a horizontal mattress fashion, from the scleral side through the corner of the scleral flap, through the posterior cut scleral edge, to complete a loose mattress suture. The knot is buried in the posterior scleral edge. The suture is tied with minimal tension (Fig. 17.5).

3.A double-armed 10/0 nylon suture is passed from the corneal side through the conjunctiva and superficial cornea at the limbus, at the temporal edge of the sclera, but not through the scleral flap.

4.The other arm of the double-armed 10/0 nylon suture is passed through the cornea and the limbus through the conjunctival flap, just as with the other end, and exits at the nasal edge of the sclera, without penetration of the scleral flap.

5.One arm of the suture is passed underneath the limb of the mattress suture that lies on top of the posterior part of the scleral flap forming a triangle. The double-armed suture is now tied, and the tension on the first mattress suture is adjusted by pulling anteriorly on the suture loop. The shape of these

Figure 17.4 Releasable sutures according to Kolker et al. (2). The corneal end of the suture is stretched and cut. It is then allowed to slip into its intra corneal suture tunnel.

Figure 17.5 Johnstone’s envelope technique of releasable sutures. [Printed with permission, from Ref. (5).]

sutures combined is like that of the back of an envelope, two triangles with the apices touching.

6.The knot of the anterior triangular loop suture is buried in the tissue of the limbal area.

When need arises, the corneal limb of the anterior tension suture is cut, and thus the tension on the mattress suture is relieved, leading to loosening of the scleral trabeculectomy flap (Fig. 17.5).

Releasable sutures allow the surgeon independence from an argon laser and a suture lysis lens. Less pressure is applied to the wound, which may lead to fewer shallow anterior chambers and conjunctival wound leaks. Releasable sutures can also be used on those patients who cannot cooperate with a laser procedure due to sensitivity following surgery, or in those patients where subconjunctival hemorrhage, edema, or scarring of the Tenon’s capsule makes visualization of the suture for argon laser lysis impossible. The releasable suture technique makes the post-trabeculectomy pressure adjustment a slit-lamp and forceps procedure only, which is economically advantageous, as well as technically simple and comfortable for the patient (2,3).

We prefer the inverted U-suture technique as it enables the release of either arm or both arms of the suture. Although the whole suture is in place and covered with epithelium, it causes no discomfort to the patient; whereas releasable sutures with loose ends often irritate the patient and allow for a continuous suture tract from outside to inside.

5.COMPLICATIONS

Releasable sutures can be complicated by epithelial defects and infection.

With the releasable U-suture, the suture is covered by epithelium until the suture removed, thus reducing the risk of infection. Releasable sutures with untied or unburied ends can irritate and cause a corneal epithelial defect.

Postoperative complications caused by releasable sutures are similar to those reported for laser suture lysis (Chapter 16). A number of studies have reported excellent

outcomes with releasable sutures (4), especially when compared to nonreleasable procedures (2,3). In summary, releasable sutures are a simple, inexpensive, and easily performed means of regulating early postoperative IOP.

REFERENCES

1.Cohen JS, Osher RH. Releasable suture in filtering and combined surgery. Ophthalmol Clin N Am 1988; 1:187 197.

2.Kolker AE, Kass MA, Rait JL. Trabeculectomy with releasable sutures. Arch Ophthalmol 1994; 112:62 66.

3.Maberley D, Apel A, Rootman DS. Releasable “U” suture for trabeculectomy surgery. Ophthal mic Surg 1994; 25:251 255.

4.Raina UK, Tuli D. Trabeculectomy with releasable sutures: a prospective, randomized pilot study. Arch Ophthalmol 1998; 116:1288 1293.

5.Johnstone MA, Wellington DP, Ziel CJ. A releasable scleral flap tamponade suture for guarded filtration surgery. Arch Ophthalmol 1993; 111:398 403.