Diagnostic Value of Compression Ultrasound to Detect Acute Compartment Syndrome After Lower Limb Revascularisation

Acute compartment syndrome (ACS) after revascularization for acute limb ischemia is a potentially limb-threatening condition and requires urgent fasciotomy. It occurs when the tissue pressure within a closed muscle compartment exceeds the perfusion pressure and results in muscle and nerve ischemia.

If clinically suspected, intra- compartmental pressure (ICP) is measured by inserting a needle into the area of ACS, usually the anterior tibial muscle compartment, while an attached pressure monitor records the pressure. This invasive diagnostic method is widely used as a standard with a sensitivity of 94% and specificity of 98%.

Compression ultrasound (CU) is an established method for measuring intravenous pressure in superficial veins and, for example, can determine central venous pressure in critically ill patients. An ultrasound translucent probe measures the pressure applied on the skin surface with the ultrasound transducer. In cadaver studies, compression ultrasound has been proven to correlate with invasive ICP measurements. The elasticity ratio (ER, compartment diameter with and without external pressure) validated in a recently published animal model has a sensitivity of 94.4% and a specificity of 88.9% to diagnose a compartment syndrome properly. The first results in six trauma patients showed that the ER less than 10,5% of the anterior tibial compartment had a sensitivity of 95,8% and a specificity of 87,5% to an appropriate diagnosis of ACS. Thus, this non-invasive, low-cost, and secure diagnostic technique has not been validated in patients with ACS after revascularisation for acute lower limb ischemia yet has the potential to discriminate clinically suspected ACS sensitively.

This study aims to determine CU's added diagnostic value compared to ICP in detecting ACS after revascularisation.