Exploration of the relationship between the height of the popliteal artery injury plane and the risk of amputation

Purpose The aim of the present study was to explore the impact of different planes of popliteal artery injury (PAI) on the risk of amputation in affected limbs. Methods A retrospective analysis was conducted on ninety-four patients who underwent PAI; these patients were divided into an amputation group (n = 26) and a nonamputation group (n = 68) on the basis of whether limb preservation was successful. The data were reconstructed from computed tomography angiography (CTA) of the patients’ lower limbs and measured via AW Volume Share 5 software. The height of the popliteal artery injury surface was quantified as follows: "L" was defined as the distance from the origin of the descending genicular artery of the contralateral limb to the origin of the anterior tibial artery; "S" was defined as the distance from the origin of the descending genicular artery of the affected limb to the blood flow interruption site; and "R" was defined as the ratio of S to L (S/L). The risk factors for amputation in patients with PAI were also analysed. Results Univariate and multivariate logistic regression analyses revealed that R (odds ratio [ OR ] = 0.876, P  = 0.006,95% CI :0.797–0.963), S ( OR  = 0.792, P  = 0.166,95% CI :0.570–1.102), ischemic time ( OR  = 1.195, P  = 0.017,95% CI :1.032–1.383), and compartment syndrome ( OR  = 5.509, P  = 0.055,95% CI :0.967–31.376) were independent risk factors for amputation in patients with PAI. The receiver operating characteristic (ROC) curve revealed that the AUC values were 0.887 ( P  < 0.000, 95% CI : 0.805–0.943) and 0.775 ( P  < 0.000, 95% CI : 0.677–0.854) for R and S, respectively. The diagnostic efficiency was highest when the diagnostic threshold values were 0.573 and 11.3 cm, for R and S, respectively. Moreover, the AUC _R was greater than the AUC _S ( Z  = 2.403, P  = 0.0162). Conclusion The height of the PAI plane is an independent risk factor for amputation in patients with PAI. Greater planes of vascular injury result in greater risk of amputation. R is better than S in the diagnosis of amputation risk in patients with PAI.