The utility of technetium 99m pertechnetate scintigraphy in the evaluationof patients with Meckel's diverticulum

Purpose: The aim of this study was to assess the utility of technetium (Tc) 99m pertechnetate scintigraphy in the diagnostic workup of the pediatric p atient with gastrointestinal (GI) bleeding and a suspected Meckel's diverti culum. Methods: The charts of 235 consecutive patients evaluated with a Meckel's s can (n = 165) or with the discharge diagnosis of Meckel's diverticulum (n = 70) between January 1975 and October 1997 were reviewed for presenting sym ptoms, bleeding characteristics, diagnostic studies and pathological diagno sis. Those patients with lower GI bleeding and a serum hemoglobin level les s than 11.0 g/dL who underwent a Tc-99m pertechnetate scan (n = 43) were as sessed for utility of the scan. Results: In all patients the Meckel's scan had a positive and negative pred ictive value of 0.93. However, in patients with lower GI bleeding and a hem oglobin less than 11.0 g/dL the Meckel's scan had a sensitivity of 0.60, a positive predictive value of 1.0, a specificity of 0.96, but only a negativ e predictive value of 0.74. As such, the probability that a child who prese nts with GI bleeding and a serum hemoglobin less than 11 g/dL will have a M eckel's diverticulum despite a negative Meckel's scan of 0.26. We further e valuated the eight patients with a false-negative scan: ectopic gastric muc osa was present on pathological examination in all eight patients. Pentagas trin stimulation was performed at the time of scintigraphic study in three of eight. Six of these eight patients had duplicate scans that also were ne gative. Patients with a false-negative (FN) scan had significantly increase d hospital charges when compared with those with a true positive (TP) scan (TP = $5012 +/- 1992; FN = $8554 +/- 1506; P = .0001). Clinical suspicion h ad a major effect on the decision-making process in these patients independ ent of the results of the Meckel's scan, and all eight patients ultimately underwent exploratory laparoscopy-laparotomy with Meckel's diverticulectomy despite the scan results. Conclusions: The relatively low negative predictive value of the Meckel's s can may result in the need for operative evaluation despite the scan data. As such, the contribution of the scan to clinical decision making is low. T hese findings suggest that exploratory laparotomy or laparoscopy may be ind icated instead of scintigraphic scanning in the assessment of the anemic (h emoglobin less than 11 g/dL) pediatric patient with lower GI bleeding, espe cially in patients in whom a high suspicion for a bleeding Meckel's diverti culum exists. Copyright (C) 1999 by W.B. Saunders Company.