(HealthDay News) — Two radiographic signs have been identified that have high sensitivity and specificity for gastric band slippage, according to a study published in the July issue of the American Journal of Roentgenology.
David W. Swenson, MD, from the Alpert Medical School of Brown University in Providence, R.I., and colleagues compared diagnostic performance of four radiographic signs of gastric band slippage. Data were obtained from 21 patients with a surgically proven slipped gastric band and 63 randomly selected asymptomatic gastric band patients. Two radiologists evaluated the cases for the four signs of band slippage and they calculated the sensitivity, specificity, and positive and negative predictive values for each sign.
The researchers found that an abnormal phi angle >58 degrees had sensitivity of 91–95% and specificity of 52–62% (κ=0.78). The O sign had sensitivity of 33–48% and specificity of 97% (κ=0.84). Inferior displacement of the superolateral band margin by >2.4 cm from the diaphragm had sensitivity of 95% and specificity of 97–98% (κ=0.97). The presence of an air-fluid level above the gastric band had sensitivity of 95% and specificity of 100% (κ=1.00).
“We report two previously undescribed radiographic signs of gastric band slippage that are both sensitive and specific for this important surgical complication and recommend that these signs should be incorporated into the imaging evaluation of gastric band patients,” the authors write.