Minimally Invasive
Minimally invasive surgery
Minimally invasive spine surgery is the performance of surgery through a small incision, usually with the aid of microscopes or endoscopic visualization (i.e., very small devices or cameras designed for viewing internal portions of the body). It has developed out of the desire to effectively treat disorders of the spinal discs with minimal muscle related injury and rapid recovery.
Traditionally, surgical approaches to the spine have necessitated prolonged recovery time. For example, prior to the use of the operating room microscope a large incision was used to visualize the herniated lumbar disc. In order to perform this procedure, large sections of the back muscles were moved away from their spinal attachments. First, this surgical approach (i.e., dissecting the muscles) produced the majority of the perioperative pain, which necessitated the use of significant pain medication with their inherent side effects. Also, the degree of the perioperative pain delayed return to normal daily activities and nonphysical work. Second, the dissection of the paraspinal muscles from their normal anatomic points of attachment results in a healing by scarring of these muscles. The various layers of the individual muscle scar to one another, losing their independent function. It also has been found that this type of dissection could result in the loss of innervation (i.e., the supply of nerve stimulation) of the muscles with subsequent wasting away and development of permanent weakness of the back muscles. This weakness itself may be symptomatic (as a back fatigue-type pain) and/or limit the patient’s function – particularly in those who perform physical work.
Clearly, the significant muscle injury associated with surgical approaches to the spine, the need existed for the development of less invasive surgical techniques. It was envisioned that minimally invasive techniques would offer several advantages including: -Reduced surgical complications – Reduced surgical blood loss – Reduced use of post-op narcotic pain medicines – Reduced length of hospital stay – Increased speed of functional return to daily activities
Summary of Microscopic approach
In 1965-66 Gazi Yasargil spent 14 months with R. Peardon Donaghy at the University of Vermont developing the microsurgical instrumentation and techniques that would revolutionize the surgical approach to many neurosurgical diseases. Upon returning to Zurich in 1967, he applied his knowledge and microsurgical skills to reduce the morbidity and improve the outcome in patients with aneurysms, arteriovenous malformations, various neoplasms—and herniated lumbar discs.
The first publication of the microsurgical discectomy procedure was in 1977 in the journal, Advances in Neurosurgery. It was Williams, a Las Vegas neurosurgeon and consultant to many of the casinos employing female dancers that popularized the technique in the United States. He supported his hypothesis that surgical scars could be minimized and performers could return to dancing quicker through techniques he described in his 532 reported patients. Subsequently many others have confirmed the ability to reduce incision size, blood loss and morbidity with the microsurgical technique. Success rates of microdiscectomy range from 88% to 98.5% in various series.
Because of the small incision, the diminished trauma to lumbar musculature, the easier identification of deep seated structures, the minimal traumatic manipulation of neural structures and the direct view into the disc with magnification and coaxial illumination, the great majority of neurosurgeons now use magnification if not the operating microscope in performing lumbar disc surgery.
Conclusion and Comparisons
When one compares the surgical outcome and overall experience with microsurgical discectomy to percutaneous techniques such as chemonucleolysis, automated percutaneous lumbar discectomy, modified nucleotomy and transforaminal endoscopic techniques the microsurgical approach appears to be superior in most areas. Obviously, laser discectomy has no place with extruded or sequestered fragments and none of the other techniques deal with lateral recess or foraminal stenosis, hypertrophy of the ligamentum flavum or osteophytes that occasionally are encountered unawares.
A valid comparison can be drawn between the micro-endoscopic technique and the strict microsurgical method. Proponents of MED assert that the primary differences with the microsurgical approach are 1) a smaller skin incision, 2) a muscle splitting rather than a subperiosteal approach to the lamina, 3) less postoperative pain, 4) faster hospital discharge and 5) a quicker return to employment. Once exposure through the tubular endoscopic system is obtained, the endoscopic technique for ligamentum flavum removal, discectomy and foraminotomy are the same as that used in the microsurgical approach.
With the microsurgical approach described above virtually the same size surgical incision is made, 15-20 mm, and the same surgical technique is used for discectomy. The primary difference, therefore, is a subperiosteal dissection versus a muscle splitting dissection which, in our opinion, is minor. Many surgeons have demonstrated the incision size, hospital stay and results are at least equivalent to that reported with the MED system. The return to work interval is also comparable.
Dr. El Kadi and his Associates have spent the last 25 years investigating and reporting on minimally invasive approaches to the lumbar disc. They believe there still are indications for disc ablation with lasers, endoscopic techniques and nucleotomy in very carefully selected patients. Despite the relative ease of performance in some cases, however, none of these methods have found their place in the hands of the majority of surgeons due either to the paucity of long term results, the potential and real complication rate or the learning curve in acquiring the technical skills. With the tremendous advances in neuro-imaging, better understanding of the pathophysiology of disc disease and the innovations in technological development, pursuit of unique and minimally invasive ways to treat lumbar disc disease must continue. Nevertheless, microsurgical discectomy remains the procedure of choice for the majority of patients requiring surgery and continues to be the standard against which all other procedures must be measured.
This patient presented with severe left leg pain and weakness. A large disc herniation was found on the MRI scan, with a piece of the disc migrating down away from the disc space.
From this view, you can see the large disc herniation is occupying the space where the spinal nerves would be. The white color, representing the fluid around the nerves, is completely obliterated on the left side (left and right are reversed).
This patient underwent microdiscectomy for removal of the large disc herniation. You can see the small size of the retractor used for this procedure.
These small incisions can typically be covered with a bandaid.