Laser speckle flowgraphy can also be used to show dynamic changes in the blood flow of the skin of the foot after surgical revascularization

Abstract

Objectives Laser speckle flowgraphy is a new method that enables the rapid evaluation of foot blood flow without contact with the skin. We used laser speckle flowgraphy to evaluate foot blood flow in peripheral arterial disease patients before and after surgical revascularization. Materials and methods A prospective single-center study. Thirty-one patients with 33 limbs that underwent surgical revascularization for peripheral arterial disease were included. Pre- and postoperative foot blood flows were measured on the plantar surface via laser speckle flowgraphy and skin perfusion pressure. The laser speckle flowgraphy device was used to visualize the blood flow distribution of the target skin and processed the pulse wave velocity of synchronized heart beats. The mean blood flow, which was expressed as the area of the pulse wave as the beat strength of skin perfusion on laser speckle flowgraphy converted into a numerical value, was assessed as dynamic changes following surgery. Beat strength of skin perfusion was also investigated in non-peripheral arterial disease controls (23 patients/46 limbs). Results The suitability of beat strength of skin perfusion in non-peripheral arterial disease controls was achieved; the beat strength of skin perfusion value was significantly higher in every area of interest in non-peripheral arterial disease controls compared to that in peripheral arterial disease limbs at the preoperative stage (105.8 ± 8.2 vs. 26.3 ± 8.2; P < 0.01). Although the pulse wave before surgery was visually flat in peripheral arterial disease patients, the pulse wave was remarkably and immediately improved through surgical revascularization. Beat strength of skin perfusion showed a dynamic change in foot blood flow (26.3 ± 8.2 at preoperation, 98.5 ± 6.7 immediately after surgery, 107.6 ± 5.7 at seven days after surgery, P < 0.01 for each compared to preoperation) that correlated with an improvement in skin perfusion pressure. Conclusions Laser speckle flowgraphy is a noninvasive, contact-free modality that is easy to implement, and beat strength of skin perfusion is a useful indicator of foot circulation during the perioperative period. Further analysis with a larger number of cases is necessary to establish appropriate clinical use.

Acute Effects of Whole-Body Vibration on Peripheral Blood Flow, Vibrotactile Perception and Balance in Older Adults

“…SBF of dorsal right foot was recorded by a non-contact method using a commercially available Laser Speckle Flowgraphy system (LSFG-ANW, Softcare Co., LTD., Fukuoka, Japan), following the manufacturer's instructions. The usefulness of this measurement modality in the evaluation of foot SBF has been described in the literature [36]. The recording unit of LSFG was firmly attached to the movable arm of a stand fixed on the floor and positioned 19 cm above the right foot of the subject at an angle of 20 • .…”

A systematic review of diagnostic techniques to determine tissue perfusion in patients with peripheral arterial disease

“…In addition, patients are positioned in a cylindrical tube with high noise levels, which can cause claustrophobia [62]. However, MRI enables visualization of 3D images in contrast to HSI and LSCI, both of which produce a two-dimensional color-coded map to examine the tissue perfusion in the foot [10,46].…”

“…One of the limitations of LSCI is the measurement of tissue perfusion at the dorsum of the foot. Most patients have a curvature that causes a reduced reflection of the laser, which results in inaccurate measurements [46]. This is not the case in other techniques such as, CEUS and fluorescence imaging.…”

“…LSCI is based on laser light to visualize the microcirculation of the skin [43,[45][46][47]. Light is scattered back from the skin, creating an interference pattern called a laser speckle pattern.…”

“…An additional parameter that can be calculated from LSCI is the beat strength of skin perfusion (BSSP). This is an average amplitude of dynamic cutaneous blood flow changes, synchronized with heart beats [46].…”