Accuracy of transthoracic ultrasound for the detection of pleural adhesions.

Objectives: In the era of minimally invasive surgery, preoperative detection of pleural adhesions can be very useful for the assessment of surgical approach, because pleural adhesions are the main contraindication to video-assisted thoracoscopy. The aim of this study was to assess the sensitivity and specificity of transthoracic ultrasound in the detection of pleural adhesions prior to thoracic surgery.

Methods: From February 2010 to January 2011, 142 consecutive patients (male, 98; female, 44; age range, 36-83 years, mean age, 63.4 years) undergoing surgical thoracic intervention (except for pneumothorax) were preoperatively scanned by two different surgeons. According to thoracic wall projections of lung segments, we created a nine-region topographic map, in which every pulmonary area was scanned to assess the presence or the absence of 'gliding sign' (lesion-by-lesion analysis). During operations the surgeon, blinded to the prediction, confirmed or excluded each suspected adhesion or documented other adhesions not previously identified.

Results: A total of 1192 predictions were made. Ultrasound predictions were confirmed 1124 times and refuted 68 times. Sensitivity was 80.6% (95% confidence interval, 0.740-0.872) and specificity 96.1% (95% confidence interval, 0.949-0.973). The positive predictive value was 73.2% and the negative predictive value was 97.4%.

Conclusions: Transthoracic ultrasound is an effective method for predicting pleural adhesions before thoracic surgery in experienced hands. Its safety, feasibility and low cost make it a useful method for the planning of minimally invasive surgical interventions.