USG Thoracolumbar Interfascial Plane (TLIP) in Lumbar Spine Surgeries
Condition: Regional Anesthesia
Study type: Interventional

Summary: 
      The study aims to evaluate the effect of US guided bilateral Thoracolumbar Interfascial plane
      (TLIP) block performed at the level of the lumbar spine surgery (involving 1 up to 3 adjacent
      lumbar vertebrae) after induction of general anesthesia and before starting the surgery on
      postoperative opioid consumption by the patients during the first 24 hours postoperative.
    

Detailed description: 
      Commonly performed spinal surgeries include laminectomies and discectomies, spinal fusions,
      and instrumentations, scoliosis corrections and spinal tumor excision. Conventional
      non-minimally invasive spinal surgeries usually involve extensive dissection of subcutaneous
      tissues, bones, and ligaments and thus can result in a considerable degree of postoperative
      pain. The severe pain typically last for at least 3 days with the highest pain scores
      recorded during the first 24 hours postoperative. Pain from the back originates from
      different tissues such as vertebrae & intervertebral discs, facet joint capsules, dura &
      nerve root sleeves, ligaments, fascia, and muscles, and it is directly proportional to the
      number of vertebrae involved in the surgery. Sensations from these structures are carried via
      the posterior rami of spinal nerves connected to sympathetic & parasympathetic nerves.

      Adequate pain management in this period can result in improved functional outcome, early
      ambulation, early discharge, and preventing the development of chronic pain. Many options
      exist for this purpose, but each has its limitations and applications. The postoperative
      multi-modal analgesic approach to these patients include drugs like NSAIDs, acetaminophen,
      opioids, gabapentinoids and even corticosteroids, but using drugs alone for pain management
      in these patients can prove to be problematic due to side effects like GIT problems (NSAIDs),
      urinary retention, respiratory depression , nausea & vomiting (opioids), in addition,
      prescribing postoperative opioids will be more complicated if the patient was on prolonged
      preoperative opioid regimen (due to the associated opioid resistance), that's why patients on
      opioids prior to surgery reported more time postoperatively spent in severe pain (60% versus
      38%; p=-0.002).

      Multiple loco-regional techniques were explored to help supplement the multi-modal approach
      to decrease side effects, improve quality of postoperative analgesia, increase patient
      satisfaction after lumbar spine surgeries and also to be used in Enhanced Recovery After
      Surgery (ERAS) protocols which aims at minimizing opioid analgesics whenever possible.
      Via-Catheter techniques considered include patient-controlled epidural analgesia that showed
      promising results regarding pain control but concerns were raised due to its interference
      with postoperative assessment of neurological functions & voiding, in addition, it was
      opposed by many surgeons due to the fact of putting a catheter very near to the surgical
      field. Also continuous infusion of local anesthetics was explored which resulted in decreased
      postoperative opioid consumption but also raised concerns due to the catheter being placed
      very near to the wound.

      Single injection methods that were explored in the literature include local anesthetic
      instillation of the affected nerve roots by the surgeon before wound closure, wound local
      anesthetic infiltration, and even a single low dose of intrathecal morphine administered by
      the surgeon into the intrathecal space under direct visualization at the conclusion of the
      surgery. But none of these methods was widely accepted due to limitations in the duration and
      adequacy of postoperative analgesia.

      US guided Thoracolumbar Interfascial plane (TLIP) block is a novel technique first described
      in a pilot study on volunteers published by William R. Hand and colleagues in Nov 2015, it
      was designed to target the dorsal rami of the thoracolumbar nerves as they pass through the
      paraspinal musculature (between the multifidus muscle (MF) and the longissimus muscle (LG)),
      which is analogous to the Transversus Abdominis plane (TAP) block which targets the ventral
      rami of the thoracolumbar nerves (between the Transversus Abdominis muscle and the internal
      oblique muscle).

      The block was performed bilaterally at the level of L3 and they reported a reproducible area
      of anesthesia to pinprick in a mean (SD) area covering 137.4 (71.0) cm2 of the lower back
      (including the midline) after 20 minutes of the block.

      Multiple case reports for TLIP block in lumbar spine surgery were described afterwards,
      Hironobu Ueshima and colleagues described 2 cases that required no additional postoperative
      analgesia and no complications, then another 2 cases with nearly the same results, they
      conducted a cadaveric study to assess the spread of injectate within the plane between the MF
      and LG muscles using only 5ml of blue dye solution, they verified the spread of the dye to
      the transverse process of the 3rd lumbar vertebra (level of injection) in all cadavers, so
      they suggested that the local anesthetic's injectate into the fascial plane between the MF
      and LG muscles can indeed block the posterior rami of the lumbar nerves.

      Finally they explored the continuous variation of the block in another 2 cases with reported
      pain free duration for 2 days (the duration of the study) and a pinprick anesthesia area
      covering from L1 to L4 level and no complications.

      TLIP block has the potential benefit of blocking sensations from spinal and para-spinal
      structures involved in the surgical trauma up to 1 level above and below the level of the
      block (including deeper structures, not only skin and subcutaneous tissues, unlike simple
      wound infiltration), while also sparing neurological functions of the lower limb (specially
      the motor functions) and urinary bladder functions (Voiding).
    

Intervention name(s): Thoracolumbar Interfascial Plane (TLIP) block; I.V drug based multimodal approach
Intervention type(s): Procedure; Drug
Intervention description(s): A 10 cm 21G Stimuplex needle (Braun Medical Inc, Bethlehem, PA, USA) will be inserted in a lateral-to-medial orientation with an approximate angle of 30 degrees to the skin. The needle will then be advanced under real-time in-plane ultrasound guidance through the belly of the LG towards the MF. The needle tip will be directed towards the LG/MF interface deep to the midpoint then a total volume of 20 ml of Bupivacaine 0.25% will be incrementally injected with intermittently repeated negative aspiration. Anterior spread of local anesthetic will be viewed as favourable.
The same procedure will be repeated on the left side. The patient will then be disinfected and draped and surgery will be allowed to proceed normally.; A base low dose opioid of 5mg morphine I.V every 8 hours. Rescue analgesia will be given to the patient if reported a VAS equal or more than 4 in the form of I.V morphine in 2.5mg increments till VAS returns to 4 or less in addition to 1 gm of oral acetaminophen every 6 hours
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Randomized controlled double blinded study
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Supportive Care
Keywords: spine surgery; Thoracolumbar Interfascial Plane block; regional anesthesia; postoperative analgesia; opioid consumption