Pedal medial artery calcification score as a prognostic marker for the success of surgical intervention in diabetic foot disease

T. Collins, D. Hickman, A. Pillai

Aim: Medial artery calcification (MAC) has been strongly associated with diabetes and has been linked to an increased risk of complications of diabetes such as amputation, as well as overall mortality. Scoring systems for grading the severity have recently been developed and used to show that MAC can be linked to worse outcomes in diabetic foot ulceration (DFU) treatment. Our primary aim was to investigate for a causal link between severity of pedal medial artery calcification (pMAC) and the success of surgical interventions in the treatment of DFU. Our secondary aim was to compare pMAC and traditional vascular studies used in the pre-operative assessment for surgical interventions in DFU.

Method: A single-centre retrospective observational study was performed for all patients who had undergone debridement or amputation for DFU between October 2019 and March 2023. Subjects were given a pMAC score using the Ferraresi classification. Doppler ultrasound studies were also recorded to assess for the presence of peripheral artery disease (PAD). Any further surgeries on the affected limb were recorded, as were outcomes based on available follow-up data. There was a significant variation in the proportion of AF and TAR with the ratio of AF:TAR varying more than two-fold. The number of patients that underwent surgery was 19.2% lower in 2022 compared to 2017 (2242 v 2774). Expressed as a percentage of total volume of cases, the proportion of TAR performed for end stage arthritis was significantly higher in 2022 than in 2017 (31.0% v 26.3%, p<0.001)

Results: 0 limbs were identified. 73% had no pMAC, 16% had moderate pMAC and 11% had severe pMAC. Limbs with pMAC were more likely to need multiple surgeries (no pMAC – 37%, moderate pMAC – 55%, severe pMAC – 50%), with amputation twice as likely (42%, n=8) vs the no pMAC group (20%, n=10). 74% of the groups with pMAC had no indicators of PAD in the legs.

Conclusion: Our study suggests a worse prognosis for DFU with increasingly severe pMAC and worse outcomes from DFU-related surgery with increasingly severe pMAC. Vascular studies were often very inconsistent and few patients had vascular studies distal to the ankle. Pedal MAC has the potential to be an important prognostic indicator for DFUrelated surgery.