PERCUTANEOUS ENDOSCOPIC CERVICAL DISCECTOMY- (PECD)
The goal of the procedure is decompression of the spinal nerve root by Percutaneous removal of the herniated mass and shrinkage of the nucleus pulposus under local anaesthesia. This technique has advantages such as absence of epidural bleeding and perineural fibrosis, transient or permanent myelopathy, graft related problems-donor site morbidity, painful pseudoarthrosis, graft extrusion or angular collapse, kyphotic deformity and graft impaction into the body. This Percutaneous technique has advantage of maintenance of stability of the intervertebral mobile segment. PECD has an excellent cosmetic effect, and reduced operation time and hospital stay allow the patient to return to normal daily activity more rapidly.
PECD is indicated in surgical treatment of soft cervical disc herniation contained by the posterior longitudinal ligament (subligamentous protrusion) confirmed by MRI.
PECD is contraindicated in patients presenting with a severe neurological deficit, segmental instability, acute pyramidal syndrome, progressive myelopathy. In selected cases of single level compressive disc with myelopathy and adequate canal it can be tried with due consideration of limitations.
- Rigid endoscope 6 degree with sheath 6.5 mm. in dia.
- Endoscopic disc forceps.
- Serial dilators with largest of dia. 6.1 mm.
- 18 gauge needle. Stylett. C-arm and monitor.
- C-arm fluoroscopy is used in AP and lateral planes to control the placement of all instruments throughout the operation.
ADVANTAGES OF PECD
- Day care procedure. Less traumatic physically and psychologically.
- Small incision-7mm.
- No dissection of muscle, bone, ligaments, or manipulations of dural sac or nerve roots.
- Less epidural bleeding.
- Does not promote further instability of spinal segments or postcervical fusion junctional disc herniation.
- Early return to daily activities of living.
- Mostly done under local anaesthesia.
- Costs less than open technique as less hospital stay, less medicines.
- Multilevel discectomy possible.
- Useful in medically high risk pt.'s.
- Exercises can be started the same day.
The surgeon gently pushes the trachea and larynx to opposite side with the index and middle finger and then applies firm pressure in the space between the muscles and trachea pointing towards the vertebral body surface. The trachea and oesophagus are displaced medially and the carotid sheath laterally. The anterior cervical spine is palpated with the fingertip. The puncture needle-18 gauge, is inserted through this space. The tip of the needle should be positioned on the centre or a mm. or two paramedian over the annulus. The position is confirmed with c-arm and pushed further 5mm. into disc. A guide wire - stylette is then inserted to replace the needle afterwards. A small incision 5 to 6mm. is made around the stylette.
Working Cannula insertion
Serial cannula/dilator are introduced into the disc space. The smaller one is of 3.5mm. and largest is 6.1mm. dia. It is safe to dilate the insertion site gradually. Before insertion of the final working cannula, the annulus is cut by trephine. The position of the working cannula is confirmed by c-arm.
"The Procedure is done under fluoroscopic and Endoscopic visualization."
The anterior annulus is cut with trephine. By this most of the anterior structures can be preserved unlike the anterior open discectomy. The disc forceps are used to remove the nucleus. The forcep should reach the posterior margin to remove the herniated mass effectively. The medial nucleus is removed first and then the lateral side. Extraction of the tail of hernia mass, which is more fibrotic and collagenous is tried. The disc forceps is moved in a with a 25 degree rocking excursion of cannula from side to side to increase the area of total disc removed upto approximately a 50 degree inverted cone-shaped area within the disc space. The anterior part of the disc should not be removed to avoid postoperativekyphosis. The intradiscal space is irrigated continuously with antibiotic mixed ringer saline through an irrigation channel in the forceps and the endoscope.
Most patients experience immediate improvement of their pain during the procedure and
that signifies good decompression of the root of concern. This is usually the end point of
All maneuvers are closely monitored with c-arm and Endoscopic vision.
The surgeon should confirm the tip of guidewire- stylette, dilators, annular trephine, disc forceps on the lateral fluoroscopic view, so that the ends of the instruments do not pass more than 2mm. beyond the posterior vertebral line to protect the spinal cord.
The PECD is an outpatient surgery-day care spinal surgery and can be safe and efficacious as open antero-medial cervical discectomy in selected patients.