Tube Shunt Patch Grafts:Tube Shunt Patch Grafts:Do We Need Them?Do We Need Them?

H. George Tanaka, MD H. George Tanaka, MD

Assistant Clinical ProfessorAssistant Clinical ProfessorCalifornia Pacific Medical CenterCalifornia Pacific Medical Center

San Francisco, CASan Francisco, CA

Financial DisclosuresFinancial Disclosures

• Alcon• Allergan• Glaukos

• Medicare payments for CPT 66180– 11,111 in 2011– 12,021 in 2012– 12,835 in 2013

We’re doing more tubesWe’re doing more tubes

As of January 1, 2015: As of January 1, 2015: reimbursement for CPT 67255reimbursement for CPT 67255

is bundled with CPT 66180 is bundled with CPT 66180

• Do your tubes at the hospital• Scleral flap• Needle track

Alternatives to a patch graftAlternatives to a patch graft

• Needle track– 20 gauge MVR blade– 5-6 mm posterior to limbus– no tube erosions– no tube migrations

Leong JK, et. al. : Outcome of graft free Molteno tube insertion. Br J Ophthalmol. 2006;90(4):501-505.Albis-Donado O, et. al.: Evaluation of Ahmed glaucoma valve implantation through a needle-generated scleral tunnel in Mexican children with glaucoma. Indian J Ophthalmol. 2010;58(5):365-373.Mesa-Gutierrez JC, et. al. : Graft-free Ahmed tube insertion: a modified method at 5 mm from limbus. Clin Ophthalmol. 2010;4:359-363.

Alternatives to a patch graftAlternatives to a patch graft

Scleral flaps: Back to the FutureScleral flaps: Back to the Future

Molteno ACB, Van Rooyen MMB, Bartholomew RS. Implants for draining neovascular glaucoma. Br J Ophthalmol. 1977;61:120-125.

• Tube insertion under scleral flap caused hypotony and tube-cornea touch• Scleral graft was used to maintain normal contour of tube against the globe

Scleral patch graft for Molteno setonsScleral patch graft for Molteno setons

Freedman, J. Scleral patch grafts for Molteno setons. Ophthalmic Surgery. 1987;18:532-4.

Tube insertion under scleral flapTube insertion under scleral flap

• Patch graft

• Scleral flap

• Needle

PROS CONS

FamiliarCoverageSuture lysis (cornea)

CostCosmesis (peri, sclera)Limbal edgeImmunologic?Infectious?

CostCoverageCosmesis

Need normal sclera

Need normal scleraLimited thickness

CostSpeedCosmesis

• Younger age and history of inflammation• Concomitant surgery• No association with:

– Type of implant– Implant location– Type of patch graft

Trubnik V, et. al. Evaluation of risk factors for glaucoma drainage device-related erosions: A retrospective case-control study. J Glaucoma, 2015;24(7):498-502

Chaku M, et.al. Risk factors for tube exposure as a late complication of glaucoma drainage implant surgery. Clin Ophthal 2016;10:547-553.

Risk factors for tube erosionRisk factors for tube erosion

• Patch graft

• Scleral flap

• Needle

What is the relative risk of tube erosion?

sclera

F

tube

flap

Tube erosion is caused by the forceexerted by the tube against the flap or

graft

Cross-section of flap and tube

Goal = minimize FF

tube

flap

sclera

Goal = minimize FF

flaptube

Securing tube to sclera with 10-0 nylon suture

sclera

Goal = minimize FF

tube

flap

Don’t sew flap or graft too tightly

sclera

Goal = minimize FF

tube

flap

Place sutures to “tent up” flap

sclera

Goal = minimize FF

tube

flap

Make the flap as wide as possible

sclera

• Thin sclera– High myopia– Recurrent scleritis– Other conditions

• Collagen vascular disease• Autoimmune disease• Repair tube erosion

When do I really need a patch graft?When do I really need a patch graft?

From The Sclera. C Stephen Foster, Maite Sainz de la Maza, Springer Science, Chapter 8: Non-Inflammatory Diseases of the Scleral, pg. 279, 1994.

Thank youThank you