Adjustable Sutures in Strabismus Surgery

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Adjustable Sutures in Strabismus Surgery
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Why use adjustable sutures?

• Allows binocular alignment to be refined after
  strabismus surgery
• Useful in patients in whom standard surgical
  dosages may not apply i.e. complicated strabismus
  surgery such as re-operations, orbital fracture,
  Graves orbitopathy

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Adjustable suture technique

• Advantages
• Reduce rate of re-operations
• Disadvantages
• Muscle slippage (7-41 when adjustable suture
  surgery performed on IR)
• Function of
• Magnitude of recession performed
• Nature of strabismus (? with fibrotic muscles)
• Specific muscle (IR and MR)
• Generally tied within 24 hours of initial
  procedure

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Semi-adjustable suture procedure

• Co-developed by Spielmann Campo
• 1st described in 1993
• Aim decrease the incidence of postoperative
  muscle slippage yet retain advantages of
  adjustable suture surgery
• Involves suturing the corners of the muscle
  firmly to the sclera at the desired recession
  point but also placing an adjustable suture
  through the centre of the muscle

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Kushner

• This study evaluates the procedure wrt muscle
  slippage
• In 2000 it became his standard technique for
• Recessing the IR in those patients who he wished
  to do an adjustable suture
• If recessing MR gt 12 mm from limbus

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Method I

• 2 groups
• 1. Primary treatment group never undergone
  surgery OR had but had not previously slipped
  muscle
• 57 patients on 61 muscles
• 55 IR and 6 MR
• 2. Secondary treatment group semiadjustable
  suture suture on muscles but had slipped muscle
• 7 patients
• Primary outcome occurrence of muscle slippage
  within 6-months after surgery

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Method II

• After the muscle was disinserted, the 2 corner
  sutures were sewn through the sclera at desired
  recession distance 5mm apart with needle tracks
  directed toward each other
• Bunches muscle at new insertion
• Permits centre of muscle to sag 1-2mm
• Double-armed suture securing centre of muscle was
  brought out through insertion and secured with
  6.0 polyglactin cinch tightened to level of 2
  corners
• Reference knot 30-50 mm anterior to cinch

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Method III

• Postoperative alignment performed on the morning
  after surgery
• After adjustment, the distance between the cinch
  and the knot is measured again, the difference
  representing the amount of muscle adjustment

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Criteria for muscle slippage

• Suspect if
• Angle of misalignment changed by gt 4 ? in the
  direction away from the field of action of the
  muscle between the measurement taken immediately
  after post operative suture adjustment to 6 month
  outcome
• Versions demonstrated gt 1 unit of change in the
  direction of ? underaction (5 point scale 0 to
  -4) from the 1-week r/v to 6 month outcome
• Surgically explored (n4)
• If not surgically explored, counted as slipped
  muscle

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Results

• Primary treatment group
• n0 had muscle slippage
• Secondary treatment group
• n1 had muscle slippage
• 51 year old male
• Left orbital floor with IR entrapment
• 3 prior adjustable suture procedures on IR
• Found 13.5 mm from insertion
• Advanced using non-adjustable technique

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Limitations of Semiadjustable suture

• Limited efficacy for ? recession, target an
  initial overcorrection

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Short Tag Noose Technique for Optional Late
Suture Adjustment

• Aim to evaluate a new technique which allows the
  second-stage suture adjustment to be skipped or
  delayed if the immediate postoperative alignment
  is satisfactory
• Evaluate for
• Alignment
• Reoperation
• Complications

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Method

• Retrospective study
• Simple and complex strabismus surgery
• All patients treated by a single surgeon from
  2005-2008 were evaluated

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Method II

• Fornix incision
• Recession standard hang-back
• Resection extra 1-3mm of muscle resected and
  allowed to hang back by same amount to allow for
  an ? or ? at adjustment
• Standard adjustable-suture sliding noose
• Noose sutures were trimmed to 3mm (short tag
  noose) and buried under conjunctiva

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Method III

• Patient assessed in recovery room 1-2 hours
  adjusted after procedure and gt 24 hours
• Alignment success
• 10 horizontal
• 6 ? vertical

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Alignment Results at 2 months

• 120 procedures
• Children n27 (22.5)
• Adults n97 (80.8)
• Post operative adjustment n65
• Same day n56 (46.7)
• Performed or repeated after 2 days n18
  (15.0)

Horizontal Vertical
Alignment Success 81.0 70.7
Re-operation rate 10.0 19.0
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Reoperation Results

• No statistical difference in
• Success or re-operation rate for simple or
  complex strabismus
• Success rates in time patients adjusted
• Success or re-operation rate with children
  adults

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Complications

• Slipped muscle n1
• Granuloma n2
• Recurrence of diplopa n1