1. Adjustable suture strabismus surgery - Overview Part 1 -
Christolyn Raj
Adjustable suture strabisumus surgery

2. Adjustable suture strabisumus surgery
Overview Part 1
Adjustable sutures
Indications
Patient selection
Anaesthetic considerations
Techniques
Complications
Adjustable suture strabisumus surgery

3. Adjustable sutures in strabsmus surgery
Principle : to secure EOM to sclera with a sliding knot , then when pt is awake , the length of suture b/w attachment site and muscle may be shortened or lengthened
First described by Claude Worth , first practised by Jampolsky 1975
No prospective RCTs to date on selective advantage of adjustable sutures
Few reports on use of adjustable sutures on children
Adjustable sutures in strabismus surgery . Hunter, D. Dingeman RS et al. J Paed Opthal 2009.
Number of surgeons decribe adjustable sutures in adults to improve immediate post-op alignment [refs 3, 17, 22, 26, 30-32]
Summary by Hunter, Dinegeman et al., promote use of adjustable sutures on ALL adults , including those with comitant strabismus & no prior surgery
Authors also describe use in children who met select criteria
Adjustable suture strabisumus surgery

4. Standard indications for adjustable suture strabismus surgery
Restrictive strabismus eg: TED
Previous trauma or surgery
Slipped, lost, disinserted muscles
Incomitant deviations eg : Duane’s syndrome , MG
Any longstanding, complex strabismus
Adjustable suture strabisumus surgery

5. Adjustable suture strabisumus surgery
Patient selection
Adjustable sutures can be used with recessed or resected muscles and also been successfully described on superior oblique tendon .
Goldenberg-Cohen N, et al Strabismus 13;5-10.
Most surgeons advocate adjustable suture technique in children aged 12 yrs & older
and only younger if co-operative & may require two stages of anesthesia
Active participation of parents is a key factor (Dawson et al. 2001)
Can perfom “Q-tip” test to identify suitable pts – consists of touching a cotton tip to the MR or LR aspect of the unanesthetized bulbar conjunctiva as a pre- test tolerability
If patient fails Q-tip test : consider non-adjustable suture surgery or arrange for back-up sedation
Adjustable suture strabisumus surgery

6. Anaesthetic considerations
1). Recovery of extraocular muscle function
-GA: EOM function recovers when pt awakes
-LA: short acting agents require 5hrs minimum for motility to recover
2). Patient comfort & alertness in recovery
-pre-medication: for post-op nausea
-induction with propofol preferable , shorter acting muscle relaxants preferable
-avoid opiate analgesia which may cause sedation & nausea
-topical tetracaine is often sufficient
-ketorolac early intraop is another option /7 is m.effective
Some studies report post op nausea 48-85% greater in kids – refs 11, 23 …imp that anaetetists minimise risk to decrease risk of aspiration
-factors that are imp : anxiety, opiod use, aviding NO , ketamine
Longer acting muscle relexants can delay post-op examn b/c have residual neuromuscular blocakade…also loger acting muscle rexaants require reversal with acetylchloinesterase inhibitors whch casue n & v
Wrt analgesia – ckearly these pts need good intraop & post op analgesia …but opiods a prob , narcotics ie; morphime increases n &v ,
Adjustable suture strabisumus surgery

7. Anaesthetic considerations
3). Post-op nausea & vomiting -ondansetron is very effective & has few SE’s -use with dexamethasone may augment effects of ondansetron 4). Sedation protocol for suture adjustment -mainly for unco-operative pts -inform anaethetist -should be monitored in recovery room setting to ensure airway & basic monitoring equipment is readily available -may need propofol induction dose
Beware of high dosese of metcoparmide causing extrapyramidal se’s
Sedatoon protocol dosease ..propofol 1-3mg/kg is a full induction dose & s often reqd
As an adjunct topical tetracine
Adjustable suture strabisumus surgery

8. Adjustable suture strabisumus surgery
Surgical techniques
Limbal vs fornix approach
Limbal appoach provides broad exposure but requires conjunctival closure post suture adjustment
Fornix approach may be more comfortable as sutures are covered
Technique
Bow tie
Sutures ae tied together in a single-loop bow-tie like a shoelace
At adjustment the bow is untied , muscle adjusted & re-tied, bow cut & converted to a square knot
Sliding-noose
sutures are passed through scleral tunnels emerging <1mm apart , a noose is created by tying a separate piece of suture around the scleral sutures
Adjustable suture strabisumus surgery

9. Adjustable suture strabisumus surgery
Basic adjustable suture techniques. (a) Bow tie technique: the sutures are tied together in a single-loop bow tie similar to a shoelace. (b) Sliding noose technique: a noose is created by tying a separate piece of suture around the scleral sutures. Reproduced with permission from Hunter et al.84
Adjustable suture strabisumus surgery

10. Adjustable suture strabisumus surgery
Surgical techniques
Semi-adjustable sutures
Described by (Kushner et al.) to reduce muscle slippage whilst preserving potential for adjustment
Involves suturing corners of muscle to sclera & placing centre of muscle on adjustable
Authors’ preferred technique
Describes “noose” suture
For adjustable recession standard hangback doses used
For adjustable resection an extra 1-3mm muscle is resected , then muscle allowed to hang back by same amt
After the sutures are passed , they are pulled to original insertion then these sutures are secured to each other with an overhand knot- these joined sutures are ‘ple sutures’
For the adjustable noose , an absorbable suture is used , placed underneath the pole sutures & wrapped around a second time, finally tying a square knot to prevent slippage
At adjustment the bow is untied , muscle adjusted & re-tied, bow cut & converted to a square knot
Semi adjustble – es for ir muscle which has incid of slippage 7-41%
-wrt uthors – adjustment perf 1-2hrs post in recov rm …in some case adj 1 wk ;ate
- Also authors make an impt pt re: imp to know when to stop adjusting…adj >2mm should be avoided except in unusul cases such as restructuve strab…if there is no change after an adj then consider other factors – orbital restriction etc.
Adjustable suture strabisumus surgery

11. Adjustable suture strabisumus surgery
Semiadjustable sutures showing that the corners of IR muscle are sutured firmly to the sclera and the center of the muscle is placed on an adjustable suture. Reproduced with permission from Kushner
Adjustable suture strabisumus surgery

12. Adjustable suture strabisumus surgery
Short tag noose technique showing the fornix incision (F), trimmed pole sutures (P), and trimmed noose (N) buried under the conjunctiva. Reproduced with permission from Hunter et al.84
Adjustable suture strabisumus surgery

13. Adjustable suture strabisumus surgery
Complications
*Intra-adjustment complications :
Nausea& vomiting
oculucardiac reflex
possible bradycardia
Syncope
*Postoperative healing process may be very inflammatory :
conjunctival suture granulomas etc
Adhesions
Cxs assc adj sutures rare
Can be reduced avoiding speculum , using bnx , supine positioning
Adjustable suture strabisumus surgery

14. Adjustable suture strabisumus surgery
Conclusion
Adjustable sutures provide a second chance to improve outcomes of initial strabismus surgery
However….
They can add to complexity of case
Require appropriate patient selection
Evidence to validate their advantage over convential surgery is still not universally acknowledged
Difficult learning curve involved
In this summry reop raed 14-20%
Adjustable suture strabisumus surgery