Procedure Epiduroscopy

Preparation

Epiduroscopy must be performed under full sterile operating theatre conditions. Before the procedure (30 minutes), the patient receives antibiotic prophylaxis (local protocol). In addition, video monitors, an anaesthetic monitor, C-arm, arterial pressure system, and infuse system for NaCl flushing, video-guided catheter for epiduroscopy (diameter 2.4-3,0 mm), flexible scope (6000-15000 pixels), and an insertion set, must be available. The flexible scope should be sterilised according to the hospital's local protocol.

During the procedure, the patient receives standard anaesthetic monitoring (blood pressure, heart frequency and saturation). The patient has been asked to fast before the procedure. The patient receives light sedation with one of, or a combination of, the following: midazolam, remifentanyl, propofol. During the entire procedure, communication must be possible with the patient.

Position and anatomical landmarks

The patient lies in the prone position on the operating table with a pillow under the pelvis, in such a way that the sacral bone is rotated in a ventral direction. Both cornu of the sacral hiatus are marked and palpated. When this proves to be difficult, internal rotation of the feet will widen the gluteal cleft, thus facilitating identification of the sacral hiatus. The area around the sacral hiatus is disinfected.

Procedure

The skin, underlying tissues and sacral hiatus are anaesthetised with local anaesthetics. An 18-G Tuohy needle is advanced 2-3 cm into the sacral canal. Care must be taken not to exceed the level of S3, in order to prevent intradural placement of the needle and subsequent equipment. A guide wire is directed cranially through the Tuohy needle, as close as possible to the target area. After removal of the Tuohy needle, a small incision is made at the introduction site, and a dilator is passed over the guide wire followed by the introducer sheath. The side arm of the introducer sheath is left open to allow drainage of excess saline. A flexible 0.9 mm (outer diameter) fiber-optic endocscope (magnification X45) is introduced through one of the two main access ports of a disposable 2.2 mm (outer diameter) steering catheter. The steering catheter also contains two side channels for fluid instillation. One of these side channels is used for the intermittent flush of normal saline. The other side channel is connected to an automatic monitoring system by means of a standard arterial pressure monitoring system, in order to allow for the continuous monitoring of epidural/saline delivery pressure. After distention of the sacral epidural space with normal saline, the steering catheter with the fiber-optic endoscope is slowly advanced to the target area. The epidural space is kept distended with normal saline, but the pressure should be limited to minimise the risks of compromised perfusion. Total saline volume ranges between 50 and 250 ml. When fibrosis or adhesions become visible during epiduroscopy, these can be mobilised with the tip of the endoscope. It is recommended to limit the duration of the procedure to a maximum of 60 minutes.

Complications

  • Dural puncture with post-puncture headache.
  • Catheter shearing and infection.
  • Increased pressure in the epidural space, due to the continuous pressurised liquid injection necessary to obtain a clear image.  Careful monitoring of pressure fluctuations is warranted in order to reduce the risk of prolonged increased liquor pressure, and the duration of the procedure should be limited to a maximum of 60 minutes. Retinal haematoma can occur.
  • If a patient complains of neck pain and/or headache, the procedure should be stopped (temporarily).
  • Epidural bleeding and meningitis.
  • Local pain and infection.