Figure. External photograph 10 days postoperatively, showing 6-0 plain gut “tape” traversing the wound under the intact conjunctiva (arrows), with no inflammation.
Ryan EH. Transconjunctival Plain Gut “Tape” for 23-Gauge Sclerotomy Closure. Arch Ophthalmol. 2011;129(8):1070-1072. doi:10.1001/archophthalmol.2011.205
Author Affiliations: VitreoRetinal Surgery, PA, Edina, and University of Minnesota, Minneapolis.
Small-incision “sutureless” vitrectomy has become increasingly popular, but wound leaks still occur in some cases. This can lead to postoperative hypotony and may increase the risk of endophthalmitis. I have developed a new wound closure method using transconjunctival 6-0 plain gut suture fashioned as a “tape.” Since the suture ends remain under the conjunctiva, the risk of both wicking and foreign body sensation is minimized. The patients treated with 6-0 plain gut “tape” are more comfortable than those managed with transconjunctival polyglactin 910 sutures and have low rates of hypotony. The plain gut sutures are well tolerated, showing little postoperative inflammatory reaction. This is a low-cost, effective, and simple method for wound closure when needed in small-incision vitrectomy.
Small-incision “sutureless” vitrectomy has become increasingly popular for the surgical management of vitreoretinal disorders.1,2 Despite advances in wound construction such as new blade designs and the use of beveled incisions, leaking wounds in small-incision vitrectomies still occur and can lead to postoperative hypotony.3- 7 Current management of leaking wounds includes air tamponade5,8 and/or transconjunctival or subconjunctival polyglactin 910 sutures.8,9 Polyglactin 910 sutures are very irritating to the patient and because of this, surgeons are reluctant to use them. A new suture method using 6-0 plain gut suture fashioned as a “tape” is a potential solution to the problem. The suture technique is described later, and experience with the technique in surgical cases will be reviewed.
All cases used the Alcon 23-gauge system (Alcon, Hünenberg, Switzerland), and cannulas were placed using a beveled (15°-20°) approach. The infusion pressure is set at 20 mm Hg as the cannulas are removed, and the threshold for placing a suture is low, since the gut sutures appear to be well tolerated by patients. Any evidence of bleb formation is an indication for a suture. A 1- to 2-mL air bubble may be used as a tamponade also if wound leakage appears to be significant. The 6-0 plain gut technique involves passage of the needle through the conjunctiva and partial-thickness sclera, but the ends are not tied (video). An Ethicon 1735G needle (spatula) (Ethicon, Cincinnati, Ohio) is used. Compression of the conjunctiva over the wound using a cotton-tipped applicator to push aside blood and fluid is sometimes needed to allow visualization of the sclerotomy for accurate suture placement. The plain gut suture is pulled through the wound until approximately 2 cm remains outside the wound. The distal 5 mm of plain gut suture is then crushed with the needle holder into a flat “tape,” approximately 0.3 to 0.4 mm wide, and then the suture is pulled further into the wound until the distal end disappears under the conjunctiva. Once this occurs, the proximal edge is trimmed flush so that the suture has no ends protruding through the conjunctiva. At this point, the flat “tape” traverses the wound. A cotton tip applicator is used to massage the conjunctiva so the plain gut suture has no exposed ends.
All patients undergoing 23-gauge vitrectomy after this suture method was introduced were reviewed retrospectively. Which sclerotomies leaked and which were sutured was documented in the operative notes. Sclerotomy sites were examined at the slitlamp each postoperative visit. Induration, vascular engorgement, and redness were documented. Data were collected on the incidence of intraoperative wound leakage, number of sclerotomy sutures, intraocular air tamponade, postoperative hypotony, and suture reaction. The study was approved by the Allina institutional review board, Minneapolis, Minnesota.
One hundred sixteen consecutive patients who underwent 23-gauge vitrectomy from January 2009 through August 2009 were identified and reviewed. The Alcon 1-step 23-gauge system was used in all cases, and all were 3-port vitrectomies. A total of 73 of 348 sclerotomies (20.9%) were sutured. Forty-three of the 116 patients received at least 1 suture. Fourteen patients received a 1- to 2-mL air bubble intended as a wound tamponade, while 36 had a total air-fluid exchange for posterior pathology. Suture reaction (redness, pain, episcleritis) requiring prolonged steroid treatment was seen in 3 of 73 plain gut “tape” sites. In general, suture sites showed minimal inflammation (Figure). No cases of endophthalmitis or retinal detachment were identified.
Of the first 30 patients in this series, 3 received a total of 6 sutures. Because plain gut “tape” was new, sutures were placed infrequently. Patients with frank leaks were managed with air alone and rarely with sutures. Eight patients received air alone; 2, air and suture; and 1, suture alone. In this early group, 3 of 30 patients had an intraocular pressure less than 6 mm Hg on postoperative day 1. One of the 3 with hypotony had a single suture, with no air. Of the last 30 patients, 18 received a total of 30 sutures. One of 30 had an intraocular pressure lower than 6 mm Hg, and this patient was not sutured and did have air tamponade. Because the sutures had been tolerated well postoperatively, wounds with smaller leaks were sutured, and therefore, more sutures were placed.
A beveled configuration for wound construction for small-gauge vitrectomy has been reported to improve wound integrity and decrease the likelihood of wound leaks compared with perpendicular incisions.10- 12 This technique was used without modification in all cases in this series, and despite careful wound construction, a significant percentage of wounds still leaked. Of the first 30 cases that did not get complete gas-fluid exchange in this series, 15 had at least 1 leaky wound, and some had 2 or 3. There are likely 2 causes for this finding. First, a very complete vitrectomy (as was performed in these cases) removes the residual vitreous that incarcerates and helps seal in the unsutured scleral wound after cannula removal.12 Second, a thorough vitrectomy requires rotation of both the light pipe and cutting instrument for greater than 90°, and this type of manipulation has been shown experimentally to distort the wound and tear its internal aspect.13
Postoperative hypotony is more common following small-incision vitrectomy compared with standard 20-gauge vitrectomy.3- 7 Some surgeons feel that transient postoperative hypotony is tolerable, but other reports have suggested that postoperative hypotony leads to an increased risk of endophthalmitis.4,5 Ingress of dye has been reported in a model of hypotony with a patent wound.14 Increased incidence of endophthalmitis has been reported in small-incision vitrectomy, and wound leaks and hypotony are offered as explanations for this increased incidence.15,16
Therefore, a method that closes leaking sclerotomies while retaining the advantages of small-incision vitrectomy (patient comfort, rapid healing) would be desirable.
Using 6-0 plain gut suture crushed into a flat “tape” appears to work well for this purpose. The reasons are 3-fold. First, the width of the sclerotomy in 23-gauge surgery is typically about 0.5 mm, and the plain gut suture “tape” is 0.3 mm to 0.4 mm wide, therefore nearly spanning the sclerotomy wound. Second, plain gut suture consists of collagen fibers, so a crushed 6-0 plain gut suture would expose more collagen fibers to fluids and therefore increase the likelihood of the suture expanding and closing the wound. Third, crushed plain gut suture has some frictional resistance when passing through the incision, which appears to pull the wound closed.
My experience with this technique has led to this current approach. If the wounds show no leakage at all with the infusion pressure set at 20 mm Hg, no suture or air is needed. Minimal leakage is managed by infusion (or injection) of a 1- to 2-mL air bubble, but if a bleb is seen to be still forming, a “tape” suture is placed. If air is passing through the wound, a “tape” suture is placed and rarely fails to stop leakage.
Despite advances in wound construction, wound leaks in small-incision vitrectomies still occur and can lead to postoperative hypotony. A new suturing method using transconjunctival 6-0 plain gut suture fashioned as a “tape” is comfortable for patients and can be used in 23- and 25-gauge surgeries. Because these “tape” sutures cause little subjective irritation, they are more likely to be used by the surgeon and, by reducing hypotony risk, may make small-incision surgery safer.
Correspondence: Edwin H. Ryan Jr, MD, 7760 France Ave S, 310, Edina, MN 55435 (firstname.lastname@example.org).
Submitted for Publication: March 18, 2010; final revision received September 6, 2010; accepted September 11, 2010.
Financial Disclosure: None reported.