gms | German Medical Science

Objectives/Interrogation: The anterolateral thigh (ALT) flap is a commonly utilized perforator-based flap used in upper extremity reconstructive surgery. Previous studies have used MRA and CTA to image the ALT. However, these techniques require contrast or radiation. No prior studies have investigated the efficacy of using non-contrast magnetic resonance imaging (MRI) to assess ALT perforators. Our study investigates the efficacy of using non-contrast MRI to characterize the number, location, and course of dominant skin perforators of the ALT.

Methods: We queried our institutional database for 100 non-contrast thigh MRI exams from July 2013-July 2018 that included an axial fat suppression sequence from the lesser trochanter (LT) to the distal musculotendinous junction of the rectus femoris. We excluded studies with artifact that precluded reliable evaluation. All images were analyzed with OsiriX (Pixmeo SARL, Geneva). Perforator course, size, and location relative to bony landmarks were determined.

Results and Conclusions: Of 100 exams, 277 perforators in 170 legs were identified. Of these, 101 were septocutaneous (36.46%) and 176 were musculocutaneous (63.54%). An average of 1.63 perforators were visualized in each leg (min 1; max 4). The average perforator diameter was 2.53mm (SD 0.5). For n=22 perforators where the ASIS and patella were captured on imaging, the average site of perforator exit along the ASIS-patella line was 0.5 (SD 0.08; min 0.372, max 0.64). Perforators are shown in Figure 1 [Fig. 1] and Figure 2 [Fig. 2].

Perforator course, size, and location can be measured using non-contrast MRI. Non-contrast MRI is a low-morbidity imaging modality that may serve as an effective tool to aid in preoperative planning for use of the ALT flap.