Lumbar myelography with Omnipaque (iohexol)

Outpatient lumbar radiculography: comparison of iopamidol and iohexol and a literature review

A prospective study of 261 patients undergoing lumbar radiculography using 12 ml iopamidol (200 mgI/ml) was undertaken to determine whether the procedure could be performed safely on an outpatient basis. No statistically significant differences in the incidence and severity of side-effects were found between the 132 outpatients and 129 inpatient controls. Nine outpatients had to be kept in hospital at the end of a 4-h observation period and a further two outpatients were re-admitted to hospital because of severe side-effects. The current study was compared with a preceding study of identical design, already published, in which 200 patients underwent lumbar radiculography with 10 ml iohexol (240 mgI/ml). No statistically significant differences in the incidence and severity of side-effects between the two contrast media were evident up to 24 h after the examination. In the period between 24 h and 7 days, the incidence and severity of headache, nausea and dizziness were all significantly greater in the iopamidol group. Although outpatient radiculography can be performed safely with both contrast media, the higher incidence of delayed side-effects in the iopamidol patients prompts the authors to express a preference for iohexol for intrathecal use. The increased incidence of adverse reactions in female patients and the literature comparing iopamidol and iohexol for myelography are discussed.

Side effects after ambulatory lumbar iohexol myelography

Side effect incidences after ambulatory (22G needle and two h bed rest) and after non-ambulatory (22 and 20G needles and 20 h bed rest) lumbar iohexol myelography have been estimated and compared. Headache incidence was significantly greater in ambulatory (50%, n = 107) as compared to non-ambulatory myelography (26%, n = 58). Headaches in the ambulatory group tended to be of shorter duration and the difference between severe headaches in ambulatory and non-ambulatory groups was not significant. Serious adverse reactions did not occur and none of the ambulatory patients required readmission because of side effects. The headache was predominantly postural and occurred significantly earlier in the ambulatory group. Headache incidence was significantly greater after 20G needle myelography (44%, n = 97) as compared to 22G needle iohexol myelography (26%, n = 58). The results supports the hypothesis that CSF leakage is a major cause of headache after lumbar iohexol myelography.

Which factors affect reported headache incidences after lumbar myelography? A statistical analysis of publications in the literature

Nineteen publications were reviewed and subjected to a combined statistical analysis (meta-analysis) regarding the influence of study design factors upon reported headache and total symptom incidences after lumbar iohexol myelography. A significant association was found between reported side effects on one hand and needle diameter, follow up time and the method of questioning respectively on the other. The combination of long follow-up time and specific questioning and the combination between larger diameter (20G) needles and long follow-up time, both seemed to be strong predictors for reporting high side effect incidences. Nine studies were similarly analyzed regarding the influence of early ambulation and contrast type upon reported headache incidences. Early ambulation significantly increased headache after iohexol or iopamidol lumbar myelography as opposed to metrizamide myelography.