Background: Percutaneous spine biopsy has widely replaced open biopsy. We conducted a meta-analysis to evaluate the effect of the inner diameter of the biopsy needle and the method of imaging guidance on the adequacy and accuracy of tissue samples and to evaluate the complication rates associated with the different needle diameters and imaging guidance methods.
Methods: We searched MEDLINE for studies that evaluated either the adequacy (whether or not a diagnosis could be made on the basis of pathologic examination) or the accuracy (whether or not the primary diagnosis was correct) of samples obtained by means of percutaneous spine biopsy. These articles and their relevant references subsequently were reviewed twice and were evaluated against the inclusion criteria, yielding twenty-five studies. The inclusion criterion was the use of a biopsy instrument (a fine needle or trephine with an identifiable inner diameter) under the guidance of imaging (fluoroscopy or computed tomography) for the evaluation of an identified spine lesion, with the report of either adequacy or accuracy. Meta-analysis with use of the random-effects model was used to analyze the data.
Results: The adequacy, accuracy, and complication rates increased with the inner diameter of the needles, but, with the numbers available, only the complication rate increased significantly (p = 0.01). Although the use of a computed tomography scan slightly increased the adequacy and accuracy of the samples, these increases were not significant. The complication rate associated with the use of computed tomography was 3.3%, compared with 5.3% for fluoroscopy.
Conclusions: As the outcomes associated with computed tomography were not significantly different from those associated with fluoroscopy, the decision to use one or the other requires the consideration of other factors, such as the type, level, and vertebral location of the lesion as well as the expertise of the physician. In situations in which the use of a needle with a small inner diameter is highly effective (for example, in cases of metastatic lesions), the clinician should first consider using a needle with a smaller inner diameter to obtain the biopsy specimen because of the higher complication rate associated with large-bore needles. However, in cases of sclerotic lesions, in which obtaining an adequate sample can be difficult, the use of a needle with a larger inner diameter is desirable.
Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.