Delayed Management of Popliteal Artery Injury Following Knee Dislocation—A Case Report

Knee dislocations frequently involve vascular injuries that demand early diagnosis and timely intervention. Time of ischemia is pivotal in determining the outcome for the limb, delays in treatment beyond 8 hours significantly increase the risk of limb loss. Unfortunately, this critical window is often missed in resource-limited settings. Here we report a 25-year-old female sustained a left knee injury after falling into a trench. She was diagnosed with an open knee dislocation accompanied by a popliteal artery injury. However, revascularization was delayed for 18 hours due to limited resources, including the unavailability of a thrombectomy catheter. Postoperatively, the patient received anticoagulation therapy with serial limb assessments and after 3 weeks the laceration healed and the limb was still viable. Knee dislocations frequently result in vascular injury (popliteal artery most common), making prompt diagnosis and intervention essential for limb preservation. In settings with limited resources, like ours, delayed presentation and transfer to specialized centers contribute to prolonged ischemic times. Nonetheless, viable limbs should be revascularized in stable patients, even with prolonged ischemia. This case highlights the importance of limb revascularization despite delay. Efforts should be made to improve prompt diagnosis, timely referral, and availability of necessary equipment for vascular repair to optimize outcomes in similar cases.

Popliteal Artery Aneurysms

A popliteal artery aneurysm is defined as a dilation of the popliteal artery greater than 20 mm, or greater than 50% at diameter of the native artery. Popliteal artery aneurysms are rare, but are most common in the lower extremities. These aneurysms have a high risk of ischemic complications and amputations even in unoperated patients. We describe the case of a 54-year-old man, hypertensive, with a large popliteal artery aneurysm. Doppler ultrasound and CT angiography of the lower limbs showed a 100 × 80 mm aneurysm of the popliteal artery. This aneurysm is responsible for venous compression with edema of the tissues under the skin. The patient was treated and a flattening of the aneurysm associated with bypass by the inverted right internal saphenous vein taken from the ipsilateral leg was performed. The patient was discharged on the 6th day of the operation. The patient was seen again at the outpatient clinic for one month and in the 3rd month an arterial Doppler ultrasound of the lower limbs performed had shown patency of the venous graft and disappearance of the intermittent claudication.

Outcomes of Open Surgery for Popliteal Artery Aneurysms:An 18-Year Experience in a Single Institution in Japan

Objective: To elucidate the outcomes of open surgery for popliteal artery aneurysm (PAA) in a single Japanese institution. Materials and Methods: Between 1999 and 2016, 35 patients (44 PAAs) underwent open surgery in our department. The first-line surgical strategy involved the medial approach, with excision of the aneurysm sac and autologous vein bypass grafting. Associations between the outcomes and 1) the surgical management of the aneurysmal sac (aneurysmectomy vs. ligation with bypass) and 2) the preoperative clinical symptoms were evaluated. Results: There were no aneurysm-related deaths during the follow-up period (mean, 4 years;range, 1 - 17.6 years). The 5-year primary, primary-assisted, and secondary patency rates were 67.9%, 72.7%, and 94.5%, respectively. Re-intervention was required for 19 PAAs (14 patients), including two PAAs in patients with suspected Behçet’s disease. Patency rates did not differ between the aneurysmectomy and ligation groups. Remnant sac enlargement occurred in 3 cases. Among asymptomatic patients, clinical symptoms did not deteriorate;however, the ankle brachial pressure index decreased ≥0.15 in patients with artery-graft mismatching. Conclusion: Patency rates were good, and our modified ligation with bypass procedure, which involves excising the sac as much as possible, exhibited less risk in terms of remnant sac enlargement compared to that in previous studies.

Resolution of cystic adventitial disease of the popliteal artery after unsuccessful treatment of percutaneous transluminal angioplasty

Cystic adventitial disease （CAD） is a rare condition characterized by cyst!c lesions of the non-axial blood vessels adjacent to joints;j the majority of cysts are in the lower limb, with popliteal artery predominance. Here, we report a case of cystic adventitial disease in a 47-year-old man who was misdiagnosed and performed percutaneous transluminal angioplasty （PTA） in other hospital. He was eventually treated successfully with incision and evacuation of the popliteal cyst and ligation of communicating channels to the knee joint and remains asymptomatic 1 year later.

Design and mechanical properties testing of a new cross-helical popliteal artery stent

The popliteal artery has complex deformations such as axial shortening,bending,squeezing and twisting,as well as specific positions across the knee joint.Up to now there is a high incidence of in-stent restenosis(ISR)after the stent treatment of the popliteal artery.This paper aimed to design a new type of popliteal artery stent–crosshelical stent.to meet its deformation characteristics.The finite element analysis(FEA)method was used to test the mechanical properties of six stents with different winding height ratios of axial shortening,bending,plate extrusion,and torsional deformation.The results showed that the stents performance was affected by the ratio of winding height,the larger the winding height ratio,the worse the compliance,the worse the axial compressibility,but the better the radial support.And when the stent is torsional,the greater the winding height ratio is,the greater the stress is.In additon,the maximum stress was also related to the direction of torsion deformation,and the stress when the helix has the same direction with the torsion direction of the stent are was greater than that when the helix direction and torsion direction are opposite.Moreover,when the winding height ratio is 3:5,the performance of the stent is better,not only has better flexibility,its radial force,axial compression,and torsional deformation are better.It is concluded that the new cross-helical stent can adapt to the special deformation of popliteal artery and has good mechanical properties.

Impact of leg bending in the patient-specific computational fluid dynamics of popliteal stenting

Endovascular treatment of the femoro-popliteal artery has recently become a valuable therapeutic option for popliteal arterial aneurysms.However,its efficacy remains controversial due to the relatively high rate of complications,such as stent occlusion as result of intra-stent thrombosis.The elucidation of the interplay among vessel geometrical features,local hemodynamics,and leg bending seems crucial to understand onset and progression of popliteal intra-stent thrombosis.To this aim,patient-specific computational fluid dynamic simulations were performed in order to assess the intra-stent hemodynamics of two patients endovascularly treated for popliteal arterial aneurysm by stent-grafts and experiencing intra-stent thrombosis.Both Newtonian and non-Newtonian blood rheological models were considered.Results were presented in terms of tortuosity,luminal area exposed to low(<0.4 Pa)and high(>1.5 Pa)time-averaged wall shear stress(TAWSS),area exposed to high(>0.3)oscillatory shear index(OSI),and flow helicity.Study outcomes demonstrated that leg bending induced significant hemodynamic differences(>50%increase)in both patients for all the considered variables,except for OSI in one of the two considered patients.In both leg configurations,stent-graft overlapping induced a severe discontinuity of the lumen diameter where the proximal stented zone is characterized by low tortuosity,low velocity,low helicity,low TAWSS,and high OSI;while the distal part has higher tortuosity,velocity,helicity,TAWSS,and lower OSI.Sensitivity study on applied boundary conditions showed that the different inlet velocity profiles for a given inlet waveform affect slightly the numerical solution;conversely,the shape and magnitude of the prescribed inlet waveform is determinant.Focusing on the comparison between the Newtonian and non-Newtonian blood models,the area with low TAWSS is greater in the Newtonian model for both patients,while no significant difference occurs between the surfaces with high TAWSS.

Management of Acute Lower Extremity Thrombosis Associated with Bilateral Popliteal Aneurysms Using Combined Thrombolytic Therapy and Stent Graft Repair

To the Editor：This is a brief clinical report on different endovascular procedures in the treatment of popliteal artery aneurysms （PAAs）.A 75-year-old man presented at the vascular clinic with progressive left lower limb pain at rest associated with coolness,pain,and paresthesia.His medical history was significant for hypertension and hyperlipidemia.The femoral and popliteal pulsations were only felt in the left limb.Coldness,pallor,paresthesia,delayed capillary refilling,and color changes were noted in the left limb together with rest pain.Duplex ultrasound was performed and an embolization （Rutherford Grade 2b） and bilateral PAAs were found,which on computed tomography angiogram （CTA） measured 62 mm and 82 mm with the maximum diameters in the right and left popliteal artery,respectively.Thrombus was found in both aneurysm sacs [Figure 1 a and b].Thromboembolism from the left PAA could be seen in the distal arteries.Other potentially associated aneurysms were excluded by magnetic resonance angiography.The erythrocyte sedimentation rate and C-reactive protein were moderately elevated,and thrombophilia profile was negative,and history for any orogenital ulcers was negative.

Anterior tibiofemoral dislocation after total knee arthroplasty:A case report and literature review

Anterior tibiofemoral dislocation after total knee arthroplasty is an extremely rare and serious event.Amongst English-published papers,we found only 15 relevant cases,3 of which presented vascular complications.This manuscript aims to present a 77-year-old woman with a TC-Plus(Smith&Nephew)cruciate-retaining type in first time of knee prosthesis,who suffered an anterior tibiofemoral dislocation and were admitted to our hospital.The clinical management and outcome were evaluated.Furthermore,a review of literature was performed.We concluded that early detection and surgical intervention of vascular injury is the key in the survival of the limbs.If there is still knee instability after acute recovery,it seems that revision surgery with constrained total knee arthroplasty can bring about good clinical and functional results.