Short summary

This PhD-thesis will investigate demographic changes in patients undergoing major lower extremity amputations in Denmark and examine the postoperative outcome by evaluating the risk of complications, usage of analgesics before and after surgery and health related quality of life. Finally, possibilities for improvement of treatment are investigated as a randomized controlled trial, including 124 participant allocated 1:1.

Rationale

A proper description of the patient and statement of risk factors for postoperative complications are essential tools to improve outcome after major lower extremity amputation (LEA). Major LEAs are defined as trans tibial amputation (TTA), trans femoral amputation (TFA), through the knee and through the hip. In Denmark, approximately 1800 major LEAs are performed yearly. Despite LEA is common it is an area which lack evidence based practice. At Odense University Hospital (OUH) approximately 200 major LEAs and re-amputations are performed annually. Primary TFA is the most frequent type, accounting for approximately 100 (50%) of the LEA procedures. Only few major LEAs, approx. five to ten annually are conducted at OUH on traumatic indication.

Chronic leg ischemia and infection is the most common indication for major LEA, and ischemic pain in the affected limb is often present. Patients undergoing LEA represent a frail group of patients with high co-morbidity burden as mirrored by high frequencies of arteriosclerosis (70%), diabetes (49%-63%), hypertension (42-53%) and renal insufficiency (39%). Prolonged general anesthesia and surgery as well as increased blood loss (BL) may result in impaired patient safety.

A tourniquet is used on daily basis in extremity surgery to control bleeding and provide a better visual overview for the surgeon. Currently it is debated whether use of tourniquet during surgery can prevent overall BL, reduce length of surgery and anesthesia. Investigation of the effect of tourniquet on the total BL, readmission risk, and mortality in trans-femoral amputation surgery has not been investigated previously and will be investigated in a randomized controlled trial. A pilot study to examine feasibility and aid in power calculation is planned.

The overall aim of this PhD-thesis is to investigate demographic changes in patients undergoing major lower extremity amputations on a nationwide basis in Denmark. Furthermore, this thesis evaluates the outcome of amputation; by examining the risk for complications, usage of analgesics before and after surgery and health related quality of life. Finally, possibilities for improvement of treatment are explored by investigating the use of tourniquet in TFA surgery.

Description of the cohort

Study I(register based): Patients >18 years with major LEA surgery in Denmark in a period from 2010-2020.

Study II(register based): Patients >18 years with major LEA surgery in Denmark in a period from 2010-2020.

Study III:All patients undergoing major lower extremity amputation at OUH in the period 1/3 2022-1/3 2024 will be asked to join. Relevant surveys will be send out 3-, 6- and 12-months postoperatively securely by "E-Boks". Patients will be included in the cohort in the 2-year period. Due to time from amputation to prosthesis fitting the PEQ will be used at either 6 or 12-months postoperatively. Estimated inclusion is 150 patients. This study will serve as drop-out analysis for the RCT study.

Study IV: All patients scheduled for primary, non-traumatic, transfemoral amputation surgery at The Orthopedic Department, Odense University Hospital will be screened for eligibility to participate. Inclusion period from 1/3 2022-28/2 2024. Sample size is 124 participants allocated 1:1.

Data and biological material

Study I: Register data, from the Danish National Patient Register (LPR), The Danish Civil Registration system (CRP)

Study II: Register data, from the Danish National Patient Register (LPR), The Danish Civil Registration system (CRP) and the Danish National Database of Reimbursed Prescriptions.

Study III: Prospective collection of Patient reported outcome measures. Validated surveys: EQ-D5 and Prosthesis Evaluation Questionnaire combined with clinical data from patient records.

Study IV: Clinical data, survey data, patient record data.