CTA leg images were obtained from 443 patients (male 58.5%, female 41.5%). The median age was 63 years (IQR: 50-74). The mean body mass index (BMI) of patients was 23.6±4.6 kg/m2 (range: 14.2-41.3). Most patients were non-smokers (61.9%). The comorbidities associated with atherosclerosis are shown in Table 1. HT, DM, and CKD was found in 65.8%, 45.0%, and 29.2% of patients, respectively.
According to Kim, et al. and Abou-Foul and Borumandi classification, the most common pattern observed in this study was type I-A pattern (90.5%), followed by type III-A (4.3%) and type III-B (1.8%). A list of the branching patterns found in this study is shown in Table 2. The prevalence of acquired variant was 4.3%.
The mean distance from the branching point of the anterior tibial artery to the tibial plateau was 48.9±8.3 mm, and the mean length of the tibioperoneal trunk (the common trunk of the posterior tibial artery and the peroneal artery) was 26.3±11.3 mm. The mean diameter of the anterior tibial artery, posterior tibial artery, and peroneal artery was 4.1±1.1 mm, 3.5±1.0 mm, and 3.7±1.0 mm, respectively.
Stenosis grading of popliteal artery and its branches is shown in Figure 2. Regarding grading of stenosis of popliteal artery, grade 1 stenosis was most often found (36.3%), followed by grade 2 stenosis (29.4%) and grade 0 stenosis (20.8%). The anterior tibial artery was totally occluded in 30.1%, followed by grade 1 stenosis (26.8%) and grade 2 stenosis (25.6%). For the posterior tibial artery, grade 1 stenosis was most often found (27.9%), followed by grade 3 stenosis (26.0%) and grade 2 stenosis (25.9%). The peroneal artery had grade 1 stenosis in 37.4%, grade 0 stenosis, in 24.7%, and grade 2 stenosis in 24.0%. Interestingly, the peroneal artery had a lower percentage of grade 3 (totally occluded) vessels when compared to the anterior tibial artery and the posterior tibial artery (14.0% vs. 30.1% and 26.0%, respectively).
The known risk factors for atherosclerosis were analyzed for association with significant stenosis of the popliteal artery and its collaterals. The factors identified as being significantly associated with significant stenosis of the popliteal artery in univariate analysis were DM, HT, CKD, CAD, CVD, and PAD. When those factors were entered into multivariate analysis, the results showed smoking (aOR: 2.51, 95%CI: 1.61-3.90; p<0.01), DM (aOR: 1.62, 95%CI: 1.07-2.43; p<0.05), HT (aOR: 3.05, 95%CI: 1.73-5.36; p<0.01), CKD (aOR: 1.60, 95%CI: 1.01-2.53; p<0.05), and PAD (aOR: 2.17, 95%CI: 1.26-3.75, p<0.01) to be independently associated with significant stenosis of the popliteal vessel (Figure 3A).
The factors identified as being significantly associated with significant stenosis of the anterior tibial artery in univariate analysis were DM, HT, CKD, CAD, CVD, and PAD. Multivariate analysis that included all of those factors revealed DM (aOR: 2.03, 95%CI: 1.24-3.32; p<0.01), HT (aOR: 1.81, 95%CI: 1.01-3.23; p<0.05), and PAD (aOR: 2.28, 95%CI: 1.25-4.15; p<0.01) to be independently associated with significant stenosis of the anterior tibial artery (Figure 3B).
The factors that were found to be significantly associated with significant stenosis of the posterior tibial artery in univariate analysis were DM, HT, CKD, CAD, and PAD. Multivariate analysis for this artery showed DM (aOR: 1.97, 95%CI: 1.25-3.12; p<0.05), CKD (aOR: 2.05, 95%CI: 1.29-3.28; p<0.05), and PAD (aOR: 1.82, 95%CI: 1.05-3.14; p<0.05) to be independently associated with posterior tibial artery stenosis (Figure 3C).
For the peroneal artery, which is the main supplier of blood to the fibula, the factors found to be significantly associated with significant stenosis in univariate analysis were DM, HT, CKD, and AF. Subsequent multivariate analysis revealed CAD (aOR: 0.56, 95%CI: 0.34-0.92; p<0.05) and CKD (aOR: 2.15, 95%CI: 1.37-.3.38; p<0.01) to be independently associated with significant stenosis of the peroneal artery (Figure 3D).
The acquired variants found in this study were type III-A (51.5%), type III-B (27.3%), type IV-B (12.1%), and type IV-A (9.1%). All of the aforementioned acquired variants had type I-A as congenital (native) pattern. All of these acquired variants precluded selection of the fibula due to impairment of distal limb perfusion (type III pattern) or unusable flap (type IV pattern) after FFF harvest (Figure 4).