Vascular and Transplant

Question 1

What is the Rutherford classification and how is it used?

Answer 1

Question 2

What is the management of acute limb ischaemia?

Answer 2

Theurapeutic heparin
Immediate operation
Femoral embolectomy
Four compartment fasciotomy since the ischaemic time has been greater than 4 hours

Question 3

What is the pathogenesis of malignancy in transplant?

Answer 3

1) Chronic immunosuppression
- carcinogenesis (dose and duration, type (increased risk with calcineurin and azathioprine), impaired immunosurveillance, oncoviruses (EBV, HPV, HHV8, HBV, HCV, merkel cell polyomavirus).

2) Environmental and host factors
- sun exposure, smoking, diet, EtOH
- age, genetic predisposition

3) Others
- transmitted via donor
- increased risk in native kidneys in ranal transplant pts

Question 4

What is the pathophysiology of chronic venous disease?

Answer 4

This is a result of sustained venous hypertension in the lower limb from a number of failures
This includes:
1) Valvular incompetence from degeneratvie change, chronic effects from prolonged standing, and secondary to direct injury form DVT, trauma, and phlebitis

2) Failure of calf muscle pump - associated with immobility, weak or paralysed muscles or long periods of standing.

3) Failure of vein patency - occlusion from thrombosis or external compression, destruction of vessel from trauma

The sustained venous hydrostatic pressure leads to osmotic movement of fluid as well as macromolecules

This leads to lipodermatosclerosis, haemosiderosis, and ulceration

Lipodermatosclerosis - leukocyte migration -> activation of fibroblasts -> fibrosis. ALso fibrinogen release -> fibrin -> ischaemia -> inflammation and fibrosis

Haemosiderosis -> RBCs -> haemosiderin deposition -> macrophages take up -> melanin production by melanocytes

Ulceration results from a combination of inflammation, local injury, and tissue pressure as well as ischaemia.