Case-paired analysis of the indications for percutaneous laser disc decompression

Yebin ZHENG; Fan DU; Jun YANG

ABSTRACT

BACKGROUND:

In recent years, percutaneous laser disc decompression (PLDD) has been developed gradually in China. But there have been fewer further studies on the indications and contraindications for the use of the therapy.

OBJECTIVE:

To analyze the therapeutic effect after the choice of the indications for PLDD.

DESIGN:

A case-paired observational analysis with the patients as the subjects.

SETTING:

The Department of Radiology and Department of Soft Injuries of the 474 Hospital of Chinese PLA.

PARTICIPANTS:

We recruited inpatients of the 474 Hospital of Chinese PLA after PLDD between August 1998 and December 2004 as subjects for this research. Totally 68 cases were involved. According to the same gender, the closeness in age, the cases were matched and divided into 2 groups (eg. If there were 2 or more than 2 cases with the same age, the case whose disease course is the closest one was chosen) poor indication group (n=34) and good indication group (n=34).

METHODS:

A pillow was put under the belly of the patient who lay face down on the angiographic bed with the side with serious symptoms near the outside of the bed (the side where doctor operated). Symbols were marked on the body surface under the fluoroscopy. The waist was subjected to conventional sterilization and was paved with a piece of sterile cloth. 5 Ml of lydocaine was used for anesthesia. 8-12 cm to the posterior central midline of the diseased side, an incision was made to insert the needle according to the fat and thinness of the patients, and attention to the angle adjustment was needed to enter the intervertebral disc through "the secure triangle"beneath the nerve root so that 5 mm of the exposed front segment covered the needle end completely. Cautery was made with 15 W laser for every 1s after an interval of 4 s. The total output power of laser was adjusted according to the area of intervertebral disc, which was usually 1 200-1 700joules. The gas produced should be drawn out during the cautery, and this was done at least for 3 times. If the patient felt the distending pain, drawing out gas should be performed at any time. The puncturing needle and fiberoptics were pulled out after the operation, and band-aid was applied to the local area. The patients lay at the supine position to let the doctor examine the remission and functional recovery. When the patients were discharged, modified Macnab standard was used to evaluate the therapeutic effect. Evaluation criteria According to the modified Macnab standard, the therapeutic effect can be classified into the following types excellent means disappearance of pain, no limitation in motor function, with complete recovery of normal working and movement; good means that the patients showed occasional pain, but were able to do light job; passable means that the patients showed partial improvement, but still felt pain, and were not able to work and move; poor means that the patients showed signs of nerve compression that further operation was needed. The therapeutic effect of being excellent and good was combined as good therapeutic effect,and that of being passable and poor was combined as poor therapeutic effect. X2test was performed to the paired numerative data by the author.MAIN OUTCOME

MEASURES:

① General evaluation of the therapeutic effect of the poor indication group and good indication group according to modified Macnab standard when the patients were discharged from the hospital; ② Comparison of the curative effect between the group with intervertebral disc herniation ≥ 0.6 cm and the group with intervertebral disc herniation ＜ 0.6 cm; ③ Comparison of the therapeutic effect of the group complicated with spinal canal stenosis and the group with normal spinal canal; ④ Comparison of the therapeutic effect between the group with good indications and other groups with poor indications.

RESULTS:

All the 68 patients entered the result analysis. ①The therapeutic effect in the good indication group was obviously better than that in the poor indication group, with a significant difference [85%(29/34),56%(19/34) ,χ2=5.06,P ＜ 0.05]. ② The therapeutic effect was significantly better in the group with intervertevbral disc herniation ＜ 0.6 cm than in the group with intervertevbral discs herniation ≥ 0.6 cm, but without significant difference [75 % (6/8), 50% (4/8),χ2=0.25, P ＞ 0.05]. ③The therapeutic effects were close in the group complicated with spinal canal stenosis and the group with normal spinal canal, but without significant difference [80% ( 12/15 ), 73 ( 11/15 ) ,χ2=0,P ＞ 0.05].④ The therapeutic effect in the group with good indications was obviously better than that in other groups with poor indications, with a significant difference [100%( 11/11 ), 36%(4/11), χ2=5.14,P ＜ 0.05].

CONCLUSION:

It could improve the therapeutic effects of PLDD when indications were properly chosen.