Preoperative digital photoplethysmography predicts improvement in venous function after superficial venous surgery for chronically ulcerated limbs

Objective: To evaluate digital photoplethysmography (d-PPG) in predicting the influence of superficial surgery on venous function in chronically ulcerated limbs. Design: Prospective case-study. Setting: Vascular Laboratory of a District General Hospital. Patients: Patients with ulcerated limbs referred to a specialized community leg ulcer service were assessed with colour venous duplex ultrasound and ankle-brachial pressure index and offered surgery in cases of superficial venous reflux alone. Interventions: Superficial venous surgery. Four-layer compression bandaging. Main outcome measures: D-PPG derived venous refill time (VRT) and pump power (PP) were measured preoperatively with and without a tourniquet, and again after surgery. Results: Thirty ulcerated limbs in 27 patients were assessed. VRT increased from a median (interquartile range) of 10 s (7-17) preoperatively to 26 s (19-29)* with an above-knee tourniquet, 26 s (18-32)* with a below-knee tourniquet and 19 s (15-25)* after superficial venous surgery (*p<0.01). PP increased from 2.3% (1.3-3.1) preoperatively to 3.0% (2.0-4.2)* with an above-knee tourniquet, 2.9% (2.1-4.3)** with a below-knee tourniquet and 4.4% (2.3-7.2)* after surgery (*p<0.01, **p<0.05). The increase in VRT with an above-knee tourniquet preoperatively correlated with an increase in VRT after surgery (r = 0.40, p<0.05). Conclusion: Superficial venous surgery improves venous function measured by d-PPG in chronically ulcerated limbs. Preoperative assessment with d-PPG and an above-knee tourniquet predicts functional improvement after surgery.