Improving outcomes for patients undergoing major lower limb amputation for complications of peripheral vascular disease

Background: Around 5000 patients undergo major lower limb amputation in the UK each year, commonly as a result of peripheral vascular disease. Around 10% of these patients die before hospital discharge, and 30% die within a year of surgery. Despite this, evidence for optimal management of these patients is weak. The aim of this thesis is to develop tools which will direct future research and quality-improvement towards key interventions and outcomes for these patients. Methods: I used data from the UK National Registry to identify risk-factors for poor mortality and morbidity outcomes using rigorous statistical tools and developed a prognostic model for in-hospital mortality. I identified important outcomes for patients undergoing major lower limb amputation through systematic review of the literature and focus groups. I then established consensus on core outcome sets for short- and medium-term studies recruiting these patients using a multi-round consensus survey followed by a face-to-face consensus meeting. Results: Independent risk-factors for in-hospital mortality were identified as emergency admission, bilateral operation, trans-femoral operation, age, American Society of Anesthesiologists grade, abnormal electrocardiogram and increased white cell count or creatinine, decreased albumin or patient weight. Previous revascularisation procedures were protective. I established consensus on 11 core outcomes for short-term studies and 11 core outcomes for medium-term studies. Stump wound infection or healing, problems with the other leg and psychological morbidity were present in both sets. Outcomes related to death, additional healthcare, communication and pain relief were core for short-term studies. Outcomes related to mobility, social re-integration, independence and quality of life were core for medium-term studies. Conclusions: I have identified contemporary risk-factors for peri-operative outcomes and defined core outcome sets for patients undergoing major lower limb amputation. Future work should adopt these in order to design interventions which modify key risk-factors and use core outcomes as their key endpoints