PERCUTANEOUS DISCECTOMY: TECHNIQUE, INDICATIONS, AND
CONTRAINDICATIONS, 285 CASES AND RESULTS
S.M. Rezaian, M.D., Ph.D. and D.N. Ghista, Ph, D.
California Orthopaedic Medical Clinic, Inc. 8677 Wilshire Blvd.
Beverly Hills, CA 90211, USA
Abstract. Percutaneous discectomy is another option for surgical management of herniated disc in the lumbar spine. It is extremely important to define the exact indications and contrain dictions to avoid disappointing results. In this article, based on 285 selected operated cases, an attempt is made to define indication and contraindications for the procedure. The details of the technique and the results of these cases are given. The operation is carried out under local anesthesia, as a day surgery, in over 99% of cases. No neurovascular complications occurred. Main advantages are short hospitalization, reduced risks or morbidity and mortality, and rapid recovery.
: Percutaneous Discectomy - Herniated Disc - Lumbars Spine Introduction
Mixter and Barr are credited for their classical recognition of the surgical treatment for herniated disc in the lumbar spine. The retrospective review of the results has been varied. Good results range from 46% to 97%. Complications have ranged up to 10%. The complications associated with his standard excision of disc surgery and microlumbar disc excision are similar.
Spangfort, in a series of 2,504 open discectomies, had reported mortality at 0.1%, thromboembolism at 0.003%, superficial infection at 3.2%, deep-space infection rate at 1.1%, and caudia equina lesion in five patients. Laceration of aorta or iliac artery has rarely been reported.
Dural tears, arachnoidits, and adhesions aroung nerve roots and spinal instability that leads to spinal stenosis are other well-known causes of failed disc surgery. Joseph A. Barr, in a critical speech in San Diego, advised that we must find another technique to remover the disc material with fewer iatrogenic complications.
Recently, with the advancement of diagnostic technique, it is believed that due to hyperflexion, the internal layers of annulus fibers rupture fist, and because the annulus and posterior longitudinal ligament are supplied by sinovertebral sensory nerve, severe disc symptoms occur. Such pathology has been called " internal derangement of disc".
Percutaneous discectomy had been developed in respinse to this malady and to reduce iatrogenic complications of disc surgery. Nevertheless, the exact indication for percutaneous discectomy and details of the technique have not been well defined.
We believe percutaneous discectomy is not a panacea; it will not cure all forms of disc syndrome. The best indication is a disc with internal derangement where the most peripheral layer of the annulus fibrous is still intact. It will give satisfactory results if the disc symptoms are less than 2 years old, and even better if the ruptured disc is less than 1 year old. This means that if the symptoms are not relieved with conservative treatment in 3 to 6 months, percutaneous discectomy is indicated.
We believe that patients with years of history of discs symptoms (over 2 years) will not be expected to achieve a satisfactory result. This is presumably due to the fact that with the passage of time, the nucleus pulposus becomes dry and the disc collapses. The inner of the annulus fibers get tough. Therefore, decompression will not be successful.
Another important point is that if the disc is herniated and dequestered inside the canal, percutaneous over 50 years of age may not give satisfactory results and therefore is not indicated.
Materials and Methods
From February 1985 to February 1993, 2820 Patients have been in our clinic because of back pain or leg pain, or both; 483 patients needed surgical treatment. Of those, 285 selected patients had percutaneous discectomy. There were 161 males with 124 females. Their age ranged from 13 to 57 years. There were under 40 years of age. The aim was to get the patient with a history of symptoms less than 2 years, with the preferred patient being younger than 50 years of age.
All of these patients had signs and symptoms of back pain, pain in one or both legs, and some sensory deficit or motor weakness, or both. Subjectively, all patients had back pain, except 33 who were suffering from pain in one leg, 26 with pain in both thighs, or both legs pain in 9 patients. Five patients were operated on because of intractable back pain; 177 patients had both back and one leg pain or back pain and both thighs or legs pain (N = 70).
Objectively, all patients demonstrated positive straight leg raising, except five patients with back pain only. One hundred sixty-one patients had leg weakness, and 18 patients had weakness in both legs. Four of them had profound weakness of the gluteal or quadriceps muscles plus urinary tract retention (3 male patients) and incontinence (1 female patient). All four of these patients had rectal sphincter weakness (Cauda equina syndrome). There were sensory deficits in 266 of 285 patients. Anatomical nerve deficits were present in
245, and stocking type nerve deficits were present in 21 patients. There were no sensory deficits in 19 patients. Four patients presented with urinary disturbance, severe weakness of the lower extremity, residual bladder retention, or difficulty in voiding. Two patients had previous laminectomy at the same level. One patient had recurrent herniated disc and had to have repeated percutaneous discectomy. All of the patients were from the middle and lower classes, mainly active laborers, mostly mechanics, plumbers, carpenters. Twenty-nine of these patients were working as garbage collectors for the City of Los Angeles or cities around Los Angeles. Five were students, including one 13-year old girl. One fourth of the patients were engaged in jobs with light physical activities, such as managerial positions, physicians, actors, and actresses. Minimum duration of symptoms was 3 months, with a maximum duration of 6.5 years. In addition to subjective pain and objective signs, all patients had two positive confirmatory tests, including magnetic resonance imaging (MRI), 3-7 mM in 272 patients, positive myelogram in 13 patients, positive CAT scan in 36 cases, myelogram and CAT scan in 18 cases, EMG in 132 cases. Positive discographies were recorded in 285 patients at the time of surgery. To separate out how many level(s) were to be treated depended upon the clinical symptoms and myelography or MRI findings. About 245 patients underwent discectomy at one level (125 at L4-L5 and 20 at L5-S1 level); 32 patients underwent discectomy at two levels (L4-L5 and L5-S1 levels); eight patients were subjected to discectomy at three levels (L3-L4, L4-L5, and L5-S1 levels). We commonly carried out two levels of discographies, and usually we decompressed those discs that produced dynamic symptoms.
The details of this technique and the alternative option, namely laminotomy and discectomy, were explained to all of these patients. Of 286, only a 22-year old woman refused to have percutaneous discectomy. She selected open laminotomy and discectomy. She hospitalized for 5 days, and her rehabilitation took 3 months. She is recovered and pleased with results. She is not included in these 285 cases.
All but 5 of the patients were in the hospital for 1 night. Of these five, three patients stayed in the hospital for 4 days, and two patients stayed for 2 days. Seventeen patients came in the morning and went home in the afternoon. We have used an automatic discectom made by Surgical Dynamics, Inc., and the details are as follows. The surgery always was carried out in an operating room under strict sterile surgical conditions. An anesthesiologist stood by and gave premedication to the patient and recorded vital signs. One dose of prophylactic antibiotic (Recephin 2 gm IV) was given to the patient for prevention of infection. Fortunately, no infections were noted. Whether or not the use of prophylactic antibiotic was effective is questionable. For the patient’s positioning, we used lateral decubitus position over a special table equipped with double-screen imaging intenfacility. We use right or left side approach, preferring to go on the side of the patient where there are more severe symptoms. If the patient has right sciatica, our approach was the right side, and vice versa. In 121 patients the right-side approach and in 164 patients the left-side approach was used.
The anesthesiologist always saw the patient and was standing by. All patients received premedication before arriving in the surgical suite. For surgery, we used 0.5% Marcaine between 10 and 20 cc with epinephrine for local anesthesia. During surgery 50-75 mg IV Demerol was given. After surgery, a prescription was given to take Valium 5 mg per night at bedtime. Tylenol #3 #60 was recommended 2 tablets po TID for treatment of any post-operative pain.
We used a special radiolucent table, and elevated the section of operating table under the lumbar region in such a way that a lateral convexity of approximately 20° is created. This position facilitates the technique, particularly when the aim is to approach the more difficult L5-S1 level. Needle entry was at the level of herniated disc between 9 to 11 cm from the midline, then angled 45-50° from posterolateral to anteromedial toward annulus fibrosis. We first used a guidewire. When the guidewire reached the annulus fibrous, we inserted a double working tube over the guidewire. Then we replaced the guidewire with a long #22 gauge spinal needle, 8 inches long. We put the tip of the needle inside the nucleus pulposus. We checked the position with the C-arm, both on anteroposterior and lateral position. When the position of the needle was satisfactory, we injected Omnipaque dye, and performed a discography. A normal disc will not take more than 0.5 cc of dye. The procedure is pain-free for the patient, and the picture of nucleus pulposus is round or olive-shaped. However, a ruptured disc will receive two, three or even more cc of dye. The procedure is very painful for the patient, and the symptoms of the patient are reproduced. The picture appears irregular on the screen. Because the clinical symptoms of L4-5 and L5-S1 commonly are overlapped, we routinely injected into two levels, namely L4-L5 and L5-S1 (unless the clinical picture and confirmation tests are different). By discography, we were able to reproduce the symptoms of the patient, and then we normally decompressed one disc. After discography was accomplished, the needle was removed. A guidewire was replaced in the posterior part of the damaged disc. Then the inner tube was replaced by a sharp trocar, and perforated the annulus fibrous of the disc posterolaterally. The trocar was removed, and the nucleotom was passed inside the disc. The position was checked on the C-arm TV screen, and the automatic machine was started, which cut and evacuated the degenerated part of annulus fibrosis, some material of nucleus pulposus. We continued the procedure for approximately 30 to 45 minutes. On many occasions, by levering the instrument, we went upward or downward or anterior and posterior part. But the aim was to evacuate and decompress the most posterolateral part of the disc. At the end of the surgery, normally 40 mg of Depo-Medrol was injected on epidural region at the level of the surgery. This was used as a local anti-inflammatory to reduce traumatic inflammation induced by the operation.
There was no mortality, deep or superficial infection, or deep venous thrombosis. Temporary weakness of quadriceps muscles probably due to excess injection occurred in one 36-year old male who claimed he was a recovered alcohol abuser/drinker. He was excessively sensitive to the procedure. We used 30 ml instead of 10-15 ml of Marcaine (0.5% with epinephrine). Postoperatively, the patient had weakness of the right quadriceps that lasted for 6-8 hours. The patient was kept overnight in the hospital, and was released the next day. This patient’s pain was relieved, and no sequelae were noticed as a result of this surgery. Temporary neurological deficit, e.g., numbness, occurred in five patients. This numbness was in front of the thighs and the whole leg, three times on the right approach and two times on the left approach. There were no cases of permanent paralysis of the peripheral nerves. For of six patients with failure of surgery had symptoms for more than 4 years. Five of them were over 40 years of age. One patient had recurrent symptoms and had intracanal herniation.
The results are based on a questionnaire response concerning relief of pain, return to work, and the need for medication. For the final results, we examined all of these patients in our clinic. All patients universally got some relief in the operating room. Some of them on the follow-up office visit after surgery still reported some pain for varying lengths of time. Postoperative recovery varied. Some patients walked out of the hospital and quickly resumed normal activity. None of the patients needed to use any medication for pain relief. Excellent results were seen in 110 of the patients. These 110 patients returned to their previous jobs without disability within 1 to 4 weeks. These patients did not receive any narcotic medication after surgery, and they were followed from a minimum of 2 to 7 years (average 4 years 2 months).
Good results were seen in 141 patients. These 141 patients returned to work 1 to 6 months after the surgery. They needed nonsteroidal anti-inflammatory agent medication and constant physical therapy. The recovery of these cases was slow. All 141 of these patients were involved in litigation, and probably the settlement of the litigation was the cause of delay in starting work. Fair results were seen in 28 patients. These 28 patients returned to modified jobs 6 to 12 months after surgery. They needed nonsteroidal anti-inflammatory agents and physical therapy, on and off. Six patients did not get better and were considered to show poor results. These patients needed narcotic medication. Two of them had open discectomy, and after 23 months to 27 months of rehabilitation returned to modified jobs. Two patients remain on permanent disability. Both of these patients receive narcotic medication for 2.5 – 3 years, but are not on serious medication. One of them, a female aged 41 years, gets Tylenol #3 1-2 tablets per day. She is not working. The other, a 33-year old male, needs Vicodin, 2 tablets per day. For two others, even after multiple back surgery, their pain was not relieved, and they did not go to work. Four patients have been lost to follow-up. All six patients with unsatisfactory results either were above the age of 50 years or their symptoms were over 4 years old, or both.
Normally patients are given a prescription for Valium 5-10 mg according to body weight one tablet at bedtime for 10 days, plus aspirin and codeine 2 tablets PO TID PRN for relief of postoperative pain. The patients are seen 1 week after surgery. Hyperextension back exercises are started as soon as the patient can tolerate them. The patient should return to work when able. No patient has been forced to work or change jobs.
Discussion and Conclusion
Percutaneous discectomy was introduced by Hitachi (1972), and the technique was soon promoted by Schreiver and Suezawa in Europe and by Kambin in the USA. In all of those techniques a rather large tube (diameter 4 – 6.5 mm) was used to reach the annulus fibrosus. Then the disc material was evacuated manually by a Kierson rongeur. Onik (1987) introduced the automatic power cutting and suction nucleotom. This device is much thinner (2 – 2.5 mm) and less traumatic. It attracts the material inside the tube with a pressure 15 Newton per inch and then is cut with a givtin-like blade and brought out. By manipulating the arm, one may evacuate different corners of the disc as desired. The technique is safer for the patient and easier for the operating surgeon to practice. Percutaneous discectomy is comparatively a less invasive procedure, carries less risk for the patient, hospitalization is short (day case in over 90%), rehabilitation is fast, and the results are encouraging. Nevertheless, percutaneous discectomy in our opinion is not indicated for patients over the age of 50 years because of the instability of the spine; microtightening of foramina due to collapsed disc will not respond to this technique. It is not indicated for large herniation inside the spinal canal, nor for spinal instability and spinal stenosis, and probably it is not indicated for disc syndrome with a history of symptoms lasting over 2 years because nucleus pulposus becomes dry, and the decompression will not be effective. The best results can be expected for patients with symptoms up to 2 years’ duration and who are between the ages of 15 and 50 years of age. Serious neurological complications, including cauda equina syndrome and radiculopathy have been reported (Onik 1992, White III 1992) but fortunately in this group, no patient had such a complication. The key to the success is adhering to the exact technique and taking all precautions as previously outlined.