SLR - January 2022 - Sara Solar

Maximizing the Flap Inflow in a Foot Reconstruction: Ultrasonographic Evaluation of Artery Flow in Accordance with the Angle of the Ankle

Reference: Suh, Y. C., Kim, H. B., Brown, E., Hong, J. P., & Suh, H. P. (2021). Maximizing the Flap Inflow in a Foot Reconstruction: Ultrasonographic Evaluation of Artery Flow in Accordance with the Angle of the Ankle. Plastic & Reconstructive Surgery, 148(2).

Level of Evidence: IV

Scientific Literature Review

Reviewed By: Sara Solar, DPM
Residency Program: University Hospital, Newark NJ

Podiatric Relevance: Patients with peripheral arterial insufficiency associated with comorbidities like diabetes comprise a significant percentage of the typical Podiatrist’s demographic. This decreased circulation can lead to non-healing ulcers that may require flaps. Another patient population that may require flap coverage is patients who underwent trauma with significant soft tissue deficit. The goal of this article was to assess the amount of blood flow available at different angles of ankle dorsiflexion which could allow for an increased percentage of flap take in the lower extremity.

Methods: Ten patients (seven men and three woman) with a total of 20 feet were included in the study. The mean age was 28.9 +/- 3.8. One patient was a smoker. A linear transducer with ultrasound was placed over the pedal arteries with the knee flexed in 10 degrees. The arterial flow was assessed with the ankle in three positions: dorsiflexed, relaxed, and plantarflexion. Measurements were performed three minutes after each change in position.

Results: The mean systolic blood pressure was 117 +/- 5.2 mmHg and diastolic 72 +/- 3.8. The average blood flow for the dorsalis pedis was 19.81 +/- 3.88 in the dorsiflexed position, 11.71 +/- 4.72 in relaxed, and 3.47 +/- 1.41 ml/minute in the plantarflexed position. The posterior tibial flow was 9.08 +/- 8.25, 14.78 +/- 8.25 and 19.03 +/- 5.03 ml/ minute accordingly.

Conclusions: Ankle positions in casts and splints has been an unknown factor post operatively that can help or hurt arterial inflow into a free flap in the foot. Previous studies have shown decrease in blood flow when muscles are stretched, but a rebound increase in blood flow occurs post stretch. The results of this study show that the dorsalis pedis has the greatest perfusion in dorsiflexion and the posterior tibial artery in plantarflexion. Unfortunately, during this study, the amount of sclerosis in the vessels could not be accounted for as well as the study having a small patient population with only younger patients. Another limitation was venous flow was not assessed in which venous congestion could also lead to flap failure.

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