The series - A Companion to Specialist Surgical Practice - is designed to provide trainee surgeons in higher surgical training with an excellent learning and revision resource, as well as busy practicing surgeons with a regular update in a particular sub-specialty interest. Each volume in the series gives a current and succinct summary of all the key topics within the specialty and concentrates on recent developments. To meet the increasing interest in evidence-based medicine, authors have cited whenever available, the meta analysis of randomised controlled trials and identified key references within the text which support evidence -based practice.