Local drug delivery to a human pancreatic tumor via a newly designed multiple injectable needle.

Endoscopic ultrasound-guided fine needle injection (EUS-FNI) has been proposed as a novel technique for local delivery of antitumor agents to refractory tumors, including pancreatic cancer. However, the present outcome of this strategy remains insufficient, and further improvements as well as novel agents and injection devices are required. The aim of the study was to determine the feasibility of a newly designed 'multiple injectable needle' (MIN) for EUS-FNI and the resulting improvements in the drug distribution to the tumor in comparison with straight-type needles. Human pancreatic cancer BxPC-3 cells or orthotopic tumor were transplanted subcutaneously into athymic rats. Ethanol was injected into subcutaneous tumors using a MIN or straight-type needle. Sequential sections of subcutaneous tumors were stained with hematoxylin and eosin, and tumors and injury areas were quantified using ImageJ software. In the orthotopic tumors, injection of the outer needle of the MIN, advancement of the inner needle and ethanol infusion were monitored by EUS. Injury volume of subcutaneous tumors using a MIN was greater than that with the straight-type needles, except for large tumors. Injecting process using MIN was monitored with endoscopic ultrasound (EUS). This study showed improvement in the drug distribution in a tumor, following injection with MIN compared to straight-type needles, suggesting the novel device to be feasible for use in EUS-FNI.