Although many patients who undergo initial ERC require subsequent PTBD for adequate drainage, no randomized trials comparing the two modalities for suspected MHO have been published. The main hypothesis is that even though PTBD will be more effective than ERC for decompression of suspected MHO, this advantage will be offset by the favorable safety profile and superior diagnostic capability of ERC. If, however, PTBD is found to be substantially superior (by a pre-specified margin) in terms of drainage, or if the potential advantages of ERC are not realized, then the existing clinical approach to MHO must be reappraised. Moreover, identifying patient and stricture characteristics that predict response to PTBD or ERC may be important for informing clinical decision-making and guidelines.