Complications of Percutaneous Lumbar Extraforaminotomy


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Complications of Percutaneous Lumbar Extraforaminotomy


Sang Chul Lee MD1, Ricardo Ruiz-Lopez MD, FIPP2, and Won Joong Kim MD3


1 Seoul National University, Seoul, South Korea
2 Clinica Vertebra, Spine and Pain Surgery Centers, Barcelona / Madrid, Spain
3 Pain and Rehabilitation Clinic, Fort Lee, NJ, USA


Introduction


Despite a paucity of studies examining the mechanical compression of nerve roots in lumbar foraminal spinal stenosis (LFSS), it has been assumed that LFSS results in damage to microvascular structures and continuous compression of nerve roots, subsequently causing ischemia, edema, demyelination, and C-fiber hyperactivation [1, 2]. One hypothesis of the physiopathology in LFSS is that numerous lumbar foraminal ligaments cause low back pain and radiculopathy [3, 4]. Lumbar foraminal ligaments fix the lumbosacral spinal nerves to the intervertebral foramen and protect the nerve and blood vessels from being damaged. However, if abnormal adhesion or too many foraminal ligaments exist, they may result in pain through compression of the nerve root [5]. To achieve effective decompression of LFSS by resecting foraminal ligaments, and to facilitate the spread of medication around the target nerve, specially designed instruments for percutaneous lumbar extraforaminotomy (PLEF) was invented to allow a minimally invasive procedure.


Anatomy


The boundaries of the foramen contain two mobile joints – intervertebral disc (IVD) and zygapophyseal joints. The boundaries are:



  • Roof: Inferior vertebral notch of the pedicle of the superior vertebra, ligamentum flavum at its outer free edge
  • Floor: Superior vertebral notch of the pedicle of the inferior vertebra, posterosuperior margin of the inferior vertebral body
  • Anterior wall: Posterior aspect of the adjacent vertebral bodies, the IVD, lateral expansion of the posterior longitudinal ligament, anterior longitudinal venous sinus
  • Posterior wall: Posteriorly bounded by the superior articular process (SAP) and inferior articular process (IAP) of the facet joint at the same level as the foramen, lateral prolongation of the ligamentum flavum
  • Medial wall: Dural sleeve
  • Lateral wall: Fascial sheet and overlying psoas muscle.

Structures in the intervertebral foramen are:



  • Spinal nerves (combined ventral and dorsal root in the root sheath)
  • Dural root sleeve, which becomes continuous with the epineurum of the spinal nerve at the distal end of the foramen
  • Lymphatic channels
  • Spinal branch of a segmental artery, which, after entering the foramen, divides into three branches to supply the posterior arch, neural, and intracanal structures and posterior part of the vertebral bodies
  • Communicating veins between internal and external vertebral venous plexuses
  • Two to four recurrent meningeal (sinuvertebral) nerves
  • Adipose tissue surrounding all the structures
  • Ligaments in the neural foramen.

Lumbar foraminal ligaments are composed of the following ligaments [68] (Figure 65.1):



  • Superior corporotransverse
  • Inferior corporotransverse
  • Superior transforaminal
  • Middle transforaminal
  • Inferior transforaminal.

Figure 65.1 Schematic drawing of ligaments in the lumbar neural foramen. 1 = superior corporotransverse ligament; 2 = inferior corporotransverse ligament; 3 = superior transforaminal ligament; 4 = middle transforaminal ligament; 5 = inferior transforaminal ligament; 6 = posterior transforaminal ligament [9].


Indications



  • Lumbar radicular pain with or without low back pain
  • Herniated nucleus pulposus
  • Foraminal stenosis with or without central stenosis
  • Perineural fibrosis
  • Facet arthritis
  • Hypertrophy of the ligamentum flavum
  • Previous failure of conservative management (exercise therapy, physical therapy, analgesic medication, lumbar transforaminal epidural steroid injection, percutaneous epidural adhesiolysis etc.).

Contraindications



  • Local or systemic infection
  • Uncorrected coagulopathy
  • Allergies to local anesthetics or contrast dyes
  • Spondylolisthesis (relative)
  • Severe degenerative change (relative)
  • Patient refusal.

Technique


Percutaneous Extraforaminotomy (PLEF) provides advantages as a Minimally Invasive Spine Technique:



  • Soft-tissue impingment is common
  • Ligamentum flavum hypertrophy
  • Provides access to the epidural space, posterior, and anterior canal
  • It is a safe surgery under X-ray imaging
  • Complications in experienced hands are extremely rare.

There are two specially designed instruments to implement PLEF.


1) Instrument consisting of (Figures 65.2 and 65.3):


Figure 65.2 Specially designed instruments for the percutaneous lumbar extraforaminotomy procedure [9].


Figure 65.3 Disposable set for PLEF (Park®).



  • 16G Tuohy needle
  • 14G trocar
  • Cannula
  • End mill
  • Curette
  • Catheter.

After 8–10 ml of 0.5% lidocaine was administered at the intended needle entry tract, a 15 cm, 16G Tuohy needle is inserted under anteroposterior fluoroscopic guidance. In the lateral fluoroscopic view, the needle tip is advanced until it is located at the posterior part of the borderline between the IAP and SAP. An epidurogram is then obtained after injection of 5 ml contrast to confirm that the needle is placed in the epidural space and to avoid intravascular or subarachnoid needle placement. Then, the Tuohy needle is withdrawn slightly to the level of the facet joint capsule. Subsequently, a trocar is inserted adjacent to the Tuohy needle and the Touhy needle is removed. Next, a cannula is inserted through the trocar to guide an end mill, which ultimately replaces the trocar. Finally, the end mill is placed within the epidural space in the intervertebral foramen. In the next step, the end mill is removed and a curette is introduced through the cannula while maintaining the bevel of the curette facing to the ventral side to avoid any neurovascular injury (Figure 65.4a–d).


Figure 65.4 Fluoroscopic images during lumber extraforaminotomy procedures. (a) Entry point of the needle is 12–14 cm away from the midline of the vertebral body. (b) In the lateral fluoroscopic view, the cannula tip is advanced until it is located at the posterior part of the borderline between the inferior and superior articular processes. (c) A distraction of the foraminal ligament and mechanical adhesiolysis are performed by the curette through the cannula until the tip of the curette reaches the medial border of the pedicle in the anteroposterior fluoroscopic image. (d) Postadhesiolysis epidurogram is obtained before injecting local anesthetics and corticosteroids [9] (Figure 65.5).


Figure 65.5 Needle trajectory to the intervertebral foramen by a posterolateral approach. The needle is advanced to the target foramen while avoiding any injury to the internal organs [9].


2) Instrument consisting of ( Figure 65.6):



  • Guidewire with a less than 1-mm diameter
  • Dilator with a 2-mm diameter
  • Working cannula (inner/outer diameter: 3 mm/3.5 mm)
  • Working drill with a blunt-shaped tip and a protection shield.

Figure 65.6 Specially designed instrument for the percutaneous lumbar extraforaminotomy procedure [10].

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Oct 30, 2022 | Posted by in ANESTHESIA | Comments Off on Complications of Percutaneous Lumbar Extraforaminotomy

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