Radiculopathy due to a lumbar disc herniation is a common problem in the active population. In 90% of the patients, it can be treated conservatively. Surgical management is only required when all conservative management has failed.
Surgical treatment of disc herniation has evolved since 1977 when it was first performed in Europe and 1978 when it was first performed in the US. The surgeries have changed from the use of chemicals like chymopapain to open discectomies followed by microdiscectomy and endoscopic discectomy.
The evolution of surgery has led it to a smaller incision, minimizing morbidity, and maximizing results decreased hospital stay with no significant difference in long-term reoperation rates. The use of improved instrumentation and better visualization and also the use of an operating microscope has led to the evolution of discectomy to microdiscectomy and endoscopic discectomy.
Microscopic discectomy is a gold standard procedure for lumbar disc herniation. Operating microscope not only helps improve optics but also magnifies and allows it to work with good precision. The use of loupes and headlight also gives similar results. Because of these advances, microdiscectomy can now be done as an outpatient procedure and same-day surgery.
Patients with single-level disc herniation with the presentation of radiculopathy with or without tingling or numbness or weakness who have failed conservative means and have documented nerve root compression are ideal patients for microdiscectomy or endoscopic discectomy.
Patients with radicular pain going down their leg, have consistently good results as compared to those who have lower back pain. This pain is caused due to the nerve being pressed by disc herniation. Patients with cauda equina syndrome or sudden onset worsening neurological deficit are candidates for urgent surgery and may have a guarded prognosis.
Contraindication for microdiscectomy or endoscopic discectomy includes
- Gross instability
After careful selection of the patient for surgery as indicated above, patients are taken to the operating room where they are put under general anesthesia. After anesthesia, the patients are flipped onto their bellies on a special table. All the bony prominences are well padded and the nerves are well padded.
The area of surgery is well-prepped and draped aseptically. X-ray imaging (Fluoroscopy) is used inside the operating room to identify the level before the decision. Once the incision is given, meticulous dissection and hemostasis is achieved and the back of the spine is reached, the level is again checked under x-ray.
For tubular microdiscectomy, a similar approach is performed with the use of sequential dilation and the use of tubes to visualize the area of interest. This requires no muscle stripping and minimal injury to the muscles.
While performing endoscopic discectomy, a camera is used instead of the operating microscope, and the area of surgery is visualized on a monitor. Special instruments are used to the surgery which allows the camera to project as well as perform the surgery.
After confirming the level, some of the bone from the back of the spine is removed to expose the yellow ligament (ligamentum flavum) underneath. The ligament is also excised to expose the nerve roots.
The nerve roots are carefully retracted to the other side to expose the disc herniation. The extruded disc is removed carefully. Once all the loose disc herniation is removed, the nerve roots are checked for any pressure. After a satisfactory decompression is achieved, hemostasis is achieved and the wound is closed. We also use vancomycin antibiotics in the wound along with hemostatic agents.
The incision for microdiscectomy is usually about 5 cm. Patients usually use a small dressing on their lower back. After the surgery, the patient is flipped onto their back and recovered from anesthesia and moved to the recovery unit. Once they are awake and up and about, they are discharged to their home. They are sent with pain medications.
Though the surgeries are relatively safe surgery, there are still complications that can happen which include injury to the dura, which may need primary repair. Other complications include injury to the nerve root, hematoma formation, infection, medical complications, a recurrent disc herniation may also occur. Patients who have multiple comorbidities are at higher risk of complications.
Microdiscectomy and endoscopic discectomy are safe and effective procedures, which are needed in about 10% of patients with disc herniation, having failed nonsurgical treatment. Patients who undergo surgical treatment have better outcomes than patients who underwent non-surgical treatments and are symptomatic in the long-term and allow early return to work.