Differences in Blood Flow Volume and Vascular Resistance between Free Flaps: Assessment in 58 Cases

Abstract

In free-flap transfer, blood flow in the transferred flap contributes to wound healing and to resistance against infection in the recipient site. Successful reconstructions using free tissue transfers may be required to define and choose flaps with abundant blood flow in necessary cases. We investigated blood flow in the flap by transit-time ultrasound flowmeter in 58 free-flap transfers. Flow volume was compared between flap tissues as vascular resistance in the flap was calculated. Fasciocutaneous and osteocutaneous flaps had relatively low blood flow volume, myocutaneous flaps had more, and intraperitoneal flaps had still higher blood flow volume. These differences were statistically significant. Vascular resistance significantly decreased in the same order of comparison. Our findings will help in selecting the most suitable flaps for reconstructive surgery.

The intrinsic transit time of free microvascular flaps: Clinical and prognostic implications

“…[2][3][4] These studies indicated a signifcant impact of flap resistance and blood flow velocity on the incidence of postoperative venous thrombosis. 2 Flaps with a higher vascular resistance were shown to thrombose more frequently, whereas those with lower resistance and higher blood flow velocities healed without complications.…”

Effects of Tissue Component Volumes on Vascular Resistance in Free Flaps

“…We previously showed that blood flow volume and vascular resistance of free flaps differ among flap types. 13 Fasciocutaneous and osteocutaneous flaps were associated with the highest vascular resistance, followed by myocutaneous flaps, and finally, intraperitoneal flaps. Each flap has various tissue components such as skin, fat, muscle, and bone; each tissue component contributes different vascular resistance.…”

“…prefer transit time ultrasonographic flowmetry 12,13 to assess blood flow in free flap transfer. In this method, the probe is applied directly to the vessels.…”

“…The intra-abdominal flap had the lowest vascular resistance, followed by the myocutaneous flap, with the fasciocutaneous flap having the highest vascular resistance. 13 We believe that this difference reflects the proportion of tissue components (skin, fat, and muscle) comprising free flaps since the different tissue types differ in vascular anatomy and distribution (both of which are important determinants of vascular resistance). In the present study, we analyzed the relationship between the vascular resistance of a flap and the volumes of each tissue type included in the flap.…”

Hemodynamic Analysis of a Microanastomosis Using Computational Fluid Dynamics

“…Its probe size was 2.0 mm) with a period of 1.0 s, based on the venous waveform. 7 This was set up so that the maximum value was 45.0 mL/ min at 0.14 s, the minimum value -19.0 mL/min at 0.84 s, and the mean flow volume was 13.0 mL/min (Fig. 2).…”