Farmer's lung is a form of hypersensitivity pneumonitis, which is manifested mainly as an occupational disease among dairy farmers exposed to organic dusts from moldy hay and compost in silos and lofts. In Europe and America, it has been known for many years. In Japan, it frequently occurs in Hokkaido, Iwate and Hokuriku districts during winter months from November to March. The culprit antigens are spores of actinomycetes thermophilus such as Micropolyspora faeni and Thermoactinomyces vulgaris. In recent years, various preventive measures have been taken. For instance, in order to prevent hay from heating by fermentation and the thermophile from thriving, farmers desiccate hay as much as possible and keep it in air-tight plastic containers. The result is a notable decrease in the prevalence rate of this ailment. Nonetheless, with graying the rural population, pulmonary fibrosis caused by chronic exposure to low levels of organic dust is posing a grave health problem in the dairy farming communities. As a prophylactic measure against chronic fibrotic lung disease, there is a need to implement a comprehensive heath control program consisting of continual sanitary checkups at workplace and counseling at an early stage in addition to periodic health examinations. Another health threat which has more recently loomed up in the dairy farming communities is environmental pollution.

We herein report a case of a ruptured vertebral artery dissecting aneurysm involving the origin of the posterior inferior cerebellar artery that was treated using the stent-jack technique. After parent artery occlusion of the distal vertebral artery, stenting of the posterior inferior cerebellar artery was performed. Further coiling was needed because distal vertebral artery recanalization occurred due to transformation of the coil mass. The stent-jack technique for a ruptured vertebral artery dissecting aneurysm involving the origin of the posterior inferior cerebellar artery is effective; however, careful attention to recanalization after stenting is needed due to transformation of the coil mass.