Minimally invasive surgery is a rather new branch. Its main objective is to minimize the surgical cut, and therefore decrease bleeding, pain, and swelling. It helps to shorten recovery time and the patient is able to return to full physical activity in a shorter time frame. To decrease the surgical cut, microscopes are used (to enhance the field of operation), along with an endoscope. This is a kind of speculum using its own source of light, designed to perform endoscopy procedures. The precise use of tools minimizes skin, muscle, and fascia injuries, allowing the patient to leave hospital even within 24 hours of the procedure.
Because the surgical field is so small (the incision is usually no bigger than 2-4cm), the surgeon is not opening skin tissues to such a scale as in classical surgery. Before the procedure, detailed medical tests must be performed in order to precisely define the scope and location of the surgery (RTG and MRI scans are very detailed tests displaying cross-sections of internal organs in all dimensions). During the procedure an intraoperative RTG preview must be secured.
The scope of the procedures which can be completed using minimally invasive surgery is almost the same as in classical surgery.
Laminectomy and laminotomy
This is the partial removal of the lamina, part of the vertebral arch which creates the back wall of the spine canal. This procedure is performed when there is the need to create access to the spinal canal. In cases involving the complete removal of the arch and the facet joint, it is necessary to use an implant to stabilize the level on which the surgery was performed. The procedures can be one or both-sided. Most surgical techniques require either hemiliaminectomy or laminectomy as a first step, especially in discectomy or microdiscectomy.
Foraminotomy
This is a procedure based on creating access to the spinal canal in order to widen intervertebral foramina, through which the root nerve is exiting. It is performed in cases where the spinal canal has narrowed and in cases where the root nerve is pressured in the foramina.
Microdiscectomy
In cases involving pressure on the nerve structures in the spinal canal caused by nucleus pulposus (discopathy or disc hernia), partial removal of the nucleus is necessary. The procedure is based on making a small incision above the injured or damaged disc, uncovering the vertebral arch on the suffering side, and performing hemilaminectomas (one-sided removal of vertebral arch lamino, and neighbouring yellow ligament), while maintaining the spinous process. The next step is to uncover the displaced nucleus pulposus and remove the displaced part. Only in rare cases is open discectomy required.
Intradiscal Electrothermal Therapy (IDET)
This form of therapy uses the phenomenon of controlled thermocoagulation. A catheter is placed in the vertebral disc on the inside of the anulus fibrosis (using X-ray imaging). A temperature of 50 degrees Celsius is emitted through the catheter causing changes in the structure of the collagen fibers in the anulus fibrosis surrounding the nucleus pulposus. It is a minimally invasive procedure, but it has very strict medical instructions which need to be followed in order to be successful.
Percutaneous Laser Disc Decompression (PLDD)
PLDD works using a laser. The procedure is based on the placement of a special needle in the intervertebral disc (again controlled by imaging methods), followed by the insertion of a laser fiber through the needle. The laser fiber removes fragments of the nucleus pulposus and vaporizes its contents. This allows a reduction of interdiscal pressure, as well as pressure on the nerves. The procedure lasts from 15-30 minutes and is performed under local anaesthetic, or under a short sedation caused by specific medication administered intravenously. The success rate of this procedure is high, at around 90%. This method helps to strengthen the anulus fibrosis, the reduction of disc volume is minimal, and it achieves a significant reduction of interdiscal pressure.
The procedure can be applied when anulus fibrosis is not yet damaged, and when the disc is still ‘elastic’. MRI does not confirm any disturbances in the structure and consistency of anulus fibrosis, and disc height is not yet lowered.
Selective Endoscopic Discectomy (SED/YESS)
An endoscope is used to remove hernia, protrusion, or slipped intervertebral disc. It is a piece of flexible or stiff tube with a built in camera used to project the surgical area onto a screen. In the YESS method, the so-called back ride access is used – the endoscope is slipped through a small incision into the side of the intervertebral disc, through spine muscles which are not cut but only slightly dilated. The spinal canal is bypassed. The spinal cord, dural sack, nerve roots, and vessels are not so traumatized as in classical surgery, which allows us to avoid the most common complications (none of the tools go through the spinal canal in YESS), and spine destabilization.
Percutaneus Radiofrequency Coblation Disc Nucleoplasty
During this procedure a special electrode is inserted through a needle into the disc nucleus under fluoroscopic guidance. The electrode emits gas plasma. As a result, a portion of disc is removed and it becomes decompressed. Pressure of disc hernia on the nerve root is reduced, which decreases or extinguishes pain and significantly improves the comfort of the patient. Plasma generation temperature is 40 degrees Celsius, meaning there is no risk of causing thermal damage to surrounding tissues and intensive inflammatory reaction (the appropriate division of inflammation mediators). Patients with lumbar, cervical, and lower thoracic curve discopathy qualify for this procedure.
DIAM Spinal Stabilization System
For this procedure the following conditions qualify: spine instability, intervertebral disc dislocation or degeneration, other disc conditions, lumbar intervertebral disc conditions with spinal cord and/or root nerve damage, spinal stenosis, traumatic and other spondylopathies, spondylolisthesis, pars fracture, scoliosis, klifosis, and post-hernia conditions.
Nowadays in conditions related to spine instability, instead of using classical stabilization methods (spondylosis, artodesis), the newer DIAM method of intervertebral stabilization is used. Flexible, elastic DIAM implants substitute the classic stiffer implant. DIAM takes over part of the weight, simultaneously sustaining natural spine mobility. Thanks to this, relief of pressure on spinal cord roots, spinous processes, and cord back pain is decreased. This causes proper positioning of spinous processes, reconstruction of proper facet tension, a widening of pathologically narrow intervertebral space, and stabilization of the spine curve. More importantly, we avoid tension accumulation in neighbouring segments which occur in procedures bending the spine.
The advantages of minimally and micro invasive procedures are the minimization of the surgical wound, bleeding, swelling, and shortening the hospital recovery time.