Isolated dissections and dissecting aneurysms of the posterior inferior cerebellar artery: topic and literature review.

Isolated dissections of the posterior inferior cerebellar artery (PICA) are rare. Thus, no large series of cases have been reported in the literature. Due to limited knowledge regarding the natural history of these lesions and the lack of high-quality evidence supporting various treatment options, management is controversial and practice parameters are ill defined. In order to offer a comprehensive reference for the diagnosis and management of isolated PICA dissections, the authors reviewed the National Library of Medicine from 1966 to October 2001. Twenty-seven patients averaging 43.6 years of age and including 14 males and 13 females were reported. Subarachnoid hemorrhage occurred in 20 patients, and two died. Dissections were located in the proximal PICA in 22 patients and were three times more common on the left side (left:right=3:1). Six patients were managed conservatively, and four with endovascular techniques. Seventeen had open surgery: five underwent resection, two went through trapping, and two had proximal clipping. Wrapping with muscle was performed in two patients, encasement with Sundt clips in two, and four had occipital artery (OA)-PICA bypass surgery. A meticulous analysis of reported cases with regard to clinical and pathological features, management strategies, and outcomes is presented.