Background: Endoscopic ultrasonography is technically limited in patients with obstructing oesophageal cancers if the endoscope cannot pass beyond the lesion. This problem may be overcome by preliminary endoscopic tumour dilatation, or by the use of narrower calibre 'blind' endoscopic ultrasonographic telescopes or fine-bore endoscopic ultrasonographic miniprobes. These alternatives are either potentially hazardous or time consuming and expensive. The aim of this prospective study was to determine the effect of oesophageal obstruction on the locoregional staging accuracy of endoscopic ultrasonography for oesophageal cancer.
Methods: Some 50 patients with oesophageal cancer underwent staging with endoscopic ultrasonography before oesophagectomy and the T and N stage determined by endoscopic ultrasonography was compared with final histology. In 11 cases of luminal obstruction no attempt was made to overcome the blockage and a limited mediastinal scan alone was performed.
Results: Malignant obstruction of the oesophagus did not greatly reduce the staging accuracy of endoscopic ultrasonography. It correctly assessed local infiltration in all patients with obstruction, and correctly predicted nodal stage in nine of 11 patients.
Conclusion: Tumours large enough to cause luminal obstruction are nearly all full thickness (T3), and frequently have mediastinal lymph node metastases (N1) at the time of examination. This can usually be detected from limited endoscopic ultrasonography within the mediastinum.