Clin. Radiol. (1979) 30,559-560

ylinimising Side Effects in Lumbar Radiculography DAVID LEGGE and HUGH STAUNTON

pepartments o f Radiology and Neurology, Mater Hospital Dublin 7, Ireland

An attempt was made to reduce the side effects associated with the use of Metrizamide in lumbar radiculo- graphy by the removal of the contrast medium on completion of the examination. Almost complete removal was achieved in 103 patients and of these 73% had no symptoms after examination, while 8% had severe symptoms. Eleven of 14 patients in whom removal was not attempted or was not successful had significant symptoms after examination. It is concluded that aspiration of Metrizamide will reduce the incidence and severity of the side effects associated with the use of this contrast medium.

The use of water-soluble contrast media in lumbar radiculography is well established due to the excellent anatomical detail given (Grainger et aL, 1976). Metri- zamide is now the medium of choice as Meglumine locarmate and Conray 280 are known to have an appreciable neurotoxicity (Grainger et aL, 1976), and to produce adhesive arachnoiditis in a significant proportion of patients examined (Johnson and Burrows, 1978; Hansen et al., 1978). Although Metri- zamide appears free of long-term side effects, it is associated with unpleasant symptoms such as head- ache, nausea, and vomiting (Baker et al., 1978). We have attempted to reduce these symptoms by removing this contrast medium on completion of examination. This paper describes our experience.

MATERIAL AND METHOD

Between February and October 1978, 117 patients had radiculographic studies using Metrizamide. The contrast medium was not removed from the first eight patients, but an attempt was made to remove it from the remaining 109 patients. Before this, during a five month period, 82 patients had radiculography using Meglumine Iocarmate, which was not removed after examination.

Approximately 50% of all studies were performed by one of us (D.L.), the remainder by radiologists in training.

TECHNIQUE

In both groups of patients lumbar puncture was performed using a 22 gauge short bevelled needle. Each patient was positioned prone over a pillow to reduce the lumbar lordosis. The needle was guided

fluoroscopically, so that the puncture was made exactly in the mid-line, usually at the L3/4 inter- space. Two millilitres of spinal fluid were withdrawn for laboratory analysis. In the patients examined using Meglumine Iocarmate an additional 2ml of spinal fluid were withdrawn, mixed with 5ml of Meglumine Iocarmate and then reinjected into the spinal canal. For the Metrizamide studies lOml of a Metrizamide solution containing 170 mg iodine/ml were injected into the spinal canal. During the injection o f each contrast medium the head of the table was elevated 20-30 ° . Radiographs were obtained in antero-posterior, oblique, and lateral positions and the contrast medium was not advanced more proximally than the level of L2.

In the studies when removal was attempted, the needle was left in position during examination and the contrast medium then aspirated through tubing under fluoroscopic control. Approximately 12ml of radio-opaque fluid was withdrawn before removal appeared complete, so an additional 2 or 3ml of spinal fluid were lost. No attempt was made to replace spinal fluid with saline. Following exami- nation each patient was confined to bed for 24h with his head elevated 15-20 °.

Between 24 and 36h after the examination all patients were questioned about side effects, especially, headache, neck stiffness, nausea, and vomiting. Headaches lasting 2 3 h and not requiring analgesics were considered mild, while those of longer duration necessitating analgesics and bed rest were considered severe.

RESULTS

The anatomical detail given by Meglumine Iocar- mate, and Metrizamide at a concentration of 170mg iodine/ml appeared the same.

560 CLINICAL RADIOLOGY

SIDE EFFECTS

(a) Meglumine Iocarmate: of the 82 patients examined using Meglumine Iocarmate, 22 had head- aches of which six were severe, five moderate, and 11 mild. No neurotoxic effects were observed in this series, although one patient complained of neck stiffness associated with the headache.

(b) Metrizamide: all of the eight patients from whom removal o f Metrizamide was not attempted had symptoms. Six had headaches of which three were severe, two moderate and one mild. One patient had nuchal rigidity, and one vertigo and nausea. Removal o f Metrizamide was attempted in the next 109 patients and was incomplete in six. Of these six patients, three had headaches of which one was mild, one moderate, and one severe. The other three patients had no symptoms.

Seventy-six of the 103 patients in whom aspiration of the Metrizamide appeared complete had no symptoms. Thirteen had mild headaches and five moderate headaches. Eight patients experienced severe headaches which in two instances began 24h after the examination. Two of the eight patients with severe headache had associated nausea and vomiting, and one associated neck pain.

aspirated had no symptoms and only 8% had severe symptoms. On the other hand, only 25% of the patients in Baker's series (1978) and 33% of those in Sackett's series (1977) remained free of symptoms after examination.

Headache is the commonest symptom associated with Metrizamide, having an incidence of 46% in Ahlgren's series (1975), 43% in the series by Grainger et al, (1976), and 34.5% in Irstam s series (1976). Nausea occurred in 9.4% of Ahlgren's patients and 14% in the cases reported by Grainger et al. Such a high incidence of symptoms might be acceptable for cervical and dorsal myelography where serious and often malignant disease processes are sought, but is less acceptable for lumbar studies where the patients are examined for suspected lumbar disc protrusion, a common and benign lesion. Although the symptoms are temporary, they are serious as they may prolong hospitalisation or result in postponement of operative treatment.

The foregoing evidence suggests that a reduction of the symptoms associated with the use of Metri- zamide and radiculography is achieved by its removal upon completion of the examination.

COMMENT

The use of Meglumine locarmate appeared satis- factory with only 7% of the patients having severe symptoms. However, because of the risk of neuro- toxicity as well as adhesive arachnoiditis with Meglumine Iocarmate, Metrizamide was used as soon as it became available. The unpleasant symptoms experienced by the first group of patients examined using Metrizamide contrasted with the satisfactory post-radiculography status of most patients examined using Meglumine Iocarmate. Tile continuation of such a consistent incidence o f symptoms was unacceptable to the referring clinicians, and might well have led to a reluctance to use radiculography with the conse- quence of imprecise diagnosis in cases of low back pain or sciatica.

Because of the mixability of Metrizamide with cerebrospinal fluid, it is not possible to remove every trace of the medium. However, if the radiographic examination is performed rapidly, little diffusion of the Metrizamide should occur. The result was that 73% of our patients in whom Metrizamide was

REFERENCES

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Baker, Richard A-, Hillman, Bruce J., McLennan, James E., Strand, Roy D. & Kaufman, Susan M. (1978). Sequelae of Metrizamide myelography in 200 examinations. American Journal o f Roentgenology, 130, 499-502.

Grainger, R. G., Kendall, B. E. & Wylie, 1. G. (1976). Lumbar myelography with Metrizamide - a new non-ionic con- trast medium. British Journal o f Radiology, 49, 996- 1003.

Hansen, Elsemarie Berg, Fahrenkrug, A. & Praestholm, J. (1978). Late meningeal effects of myelographic contrast media with special reference to metrizamide. British Journal of Radiology, 51,321 327.

Irstram, L. & Sellden, U. (1976). Adverse effects of lumbar myelography with Amipaque and Dimer-X. Acta Radio- logica. (Dins.J, 17, 145.

Johnson, A. J. & Burrows, E. H. (1978). Thecal deformity after lumbar myelography with iophendylate (Myodil) and meglumine iothalamate (Conray 280). British Journal of Radiology, 51,196-202.

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