Proliferative Angiopathy: A Systematic Review.

Background: First described over 4 decades ago as a diffuse form of arteriovenous malformation, cerebral proliferative angiopathy (CPA) is now categorized as a distinct vascular anomaly. Unlike arteriovenous malformation, which typically forms a well-developed vascular nidus with feeder vessels and distinct venous outflow, CPA is the product of disorganized angiogenesis; thus, it lacks a true nidus. Its characteristic cycle of ischemia, angiogenesis, and aberrant perfusion can lead to abnormal blood flow patterns that characterize the disease. Treatment of CPA has historically relied on conservative management (antiepileptic drugs), and efforts to effectively manage this pathology have been hindered by an incomplete understanding of its natural history. Methods: A systematic search of 4 databases was performed. The following variables were extracted when present: study sample size, year of publication, age(s) of patient(s), sex, presenting signs and symptoms, neurological deficits (pre- and postoperative), type of intervention, average follow-up time, and patient-reported as well as functional outcomes at last follow-up. Results: Following the search and screen, 48 studies reporting 105 CPA cases remained eligible for inclusion. These studies consisted of 41 case reports, 6 case series, and 1 retrospective cohort study. The most common modality used in treatment of CPA was conservative management (53.4%). The second most common treatment modality was endovascular embolization (36.9%). The least common treatment modality was gamma knife radiosurgery, which was used in only 2 patients. Eleven patients experienced intracranial hemorrhage as a complication of CPA; 10 of the 11 patients underwent decompressive craniectomy. Finally, revascularization surgery was reportedly used in 5 patients (4.9%). Conclusion: Although there remains a dearth of studies reporting CPA, several clearly defined traits have been identified that characterize this pathology and distinguish it from arteriovenous malformation. Nonetheless, the verdict has not yet been reached regarding the effectiveness of surgical interventions.