[Is insufflation with carbon dioxide as an ambulatory procedure for evaluating tubal patency obsolete today?]

Tubal insufflation with carbon dioxide is one of the ambulatory and non-invasive procedures in use for the evaluation of tubal patency. The aim of the present study was to investigate whether the findings obtained at tubal insufflation are reliable enough to avoid laparoscopy with instillation of dye for its inherent risk of severe operative complications. Diagnostic accuracy, positive and negative predictive value of tubal insufflation were compared with that of the reference method (laparoscopy) in 107 infertile patients of childbearing age without previous pelvic inflammatory disease, tubal or ovarian surgery. No result was obtained from tubal insufflation in 13 patients for intolerance or technical problems. The positive predictive value (percentage of correct positive findings, i.e., tubes patent) was 0.79 (130/165 tubes), the negative predictive value (percentage of correct negative findings) 0.43 (10/23) with an overall diagnostic accuracy (percentage of correct findings) of 0.74. If both tubes were reported patent on insufflation (68 patients), this finding was confirmed in 82% (56/68) on laparoscopy. The remaining 18% also include the rate of false negative findings (tubes falsely reported as occluded) on laparoscopy which may account for up to 10% according to the literature. False negative findings on insufflation were reported at a frequency of 21% (35/165 tubes).

The diagnostic accuracy of tubal insufflation with carbon dioxide is definitely inferior to that of laparoscopy. In view of the frequency of false negative findings, its use as a screening procedure should be restricted to young patients with a low probability of tubal occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)