Acute Limb Ischemia Therapies: When and How to Treat Endovascularly

Training for endovascular therapy of acute arterial disease and procedure-related complication: An extracorporeally-perfused human cadaver model study

PURPOSE

The aim of this study was to evaluate the usability of a recently developed extracorporeally-perfused cadaver model for training the angiographic management of acute arterial diseases and periprocedural complications that may occur during endovascular therapy of the lower extremity arterial runoff.

MATERIALS AND METHODS

Continuous extracorporeal perfusion was established in three fresh-frozen body donors via inguinal and infragenicular access. Using digital subtraction angiography for guidance, both arterial embolization (e.g., embolization using coils, vascular plugs, particles, and liquid embolic agents) and endovascular recanalization procedures (e.g., manual aspiration or balloon-assisted embolectomy) as well as various embolism protection devices were tested. Furthermore, the management of complications during percutaneous transluminal angioplasty, such as vessel dissection and rupture, were exercised by implantation of endovascular dissection repair system or covered stents. Interventions were performed by two board-certified interventional radiologists and one resident with only limited angiographic experience.

RESULTS

Stable extracorporeal perfusion was successfully established on both thighs of all three body donors. Digital subtraction angiography could be performed reliably and resulted in realistic artery depiction. The model allowed for repeatable training of endovascular recanalization and arterial embolization procedures with typical tactile feedback in a controlled environment. Furthermore, the handling of more complex angiographic devices could be exercised. Whereas procedural success was be ascertained for most endovascular interventions, thrombectomies procedures were not feasible in some cases due to the lack of inherent coagulation.

CONCLUSION

The presented perfusion model is suitable for practicing time-critical endovascular interventions in the lower extremity runoff under realistic but controlled conditions.

A rare complication of acute lower limb ischemia post coronavirus disease 2019 infection in a healthy pediatric patient: case report

BACKGROUND

Coronavirus Disease 2019 (COVID-19) is a novel respiratory disease that first emerged in 2019. Patients infected with this disease present with a myriad of symptoms. Limb ischemia and hypercoagulability are complications identified in adults. COVID-19-related vasculitis is a known but seldom reported complication in pediatric patients, and the treatment approach is still not well established.

CASE PRESENTATION

We report the case of a healthy four-year-old female with a history of COVID-19 who developed acute lower limb ischemia. This was initially treated as a case of acute snake envenomation by administering snake antivenom with no improvement. She eventually developed lower limb acrocyanosis with an inability to ambulate. The patient was started on interleukin-6 receptor inhibitors (tocilizumab), anticoagulants, and pulse steroid therapy. The patient had complete resolution with the loss of only one toe.

CONCLUSION

Identification of thromboembolic complications in pediatric patients with no comorbidities and a history of COVID-19 can be difficult. Early recognition and treatment have a major impact on morbidity and can increase the likelihood of limb salvage.

Embolism from a left ventricular myxoma presenting with acute limb ischaemia

Acute limb ischaemia (ALI) secondary to cardiac myxoma is uncommon. Embolic myxoma should be considered a differential diagnosis in young patients with ALI who do not have apparent cardiovascular risk factors. A multidisciplinary approach and comprehensive care can improve outcomes and optimise the collaborative treatment of ALI. Early referral to a hospital that can provide specialised treatment for ALI helps prevent significant tissue loss and surgical complications, such as amputation.A man in his 20s presented with bilateral ALI of both lower extremities, and an arterial duplex scan revealed a thrombus occluding all arterial segments of the bilateral lower extremities. An intracardiac mass adherent to the apical and anterior interventricular septum on two-dimensional echocardiography suggested a complex myxoma. The patient was diagnosed with ALI Rutherford category III, and bilateral hip disarticulation was performed. The patient was discharged with an anticoagulant.

Intravenous Infusion of Exosomes Derived from Human Adipose Tissue-Derived Stem Cells Promotes Angiogenesis and Muscle Regeneration: An Observational Study in a Murine Acute Limb Ischemia Model

INTRODUCTION

Recent studies have demonstrated that adipose tissue-derived stem cell (ADSC) transplantation could promote neoangiogenesis in various ischemic diseases. However, as whole cells, ADSCs have some disadvantages, such as shipping and storage issues, high costs, and controversies related to the fates of grafted cells in the recipients. Therefore, this study aimed to investigate the effects of intravenously infused exosomes purified from human ADSCs on ischemic disease in a murine hindlimb ischemia model.

METHODS

ADSCs were cultured in exosome-free medium for 48 h before the conditioned medium was collected for exosome isolation by ultracentrifugation. The murine ischemic hindlimb models were created by cutting and burning the hindlimb arteries. Exosomes were intravenously infused into murine models (ADSC-Exo group), with phosphate-buffered saline (PBS) used as a placebo (PBS group). Treatment efficacy was determined using a murine mobility assay (frequency of pedaling in water per 10 s), peripheral blood oxygen saturation (SpO₂ index), and the recovery of vascular circulation by trypan blue staining. The formation of blood vessels was shown by X-ray. Expression levels of genes related to angiogenesis and muscle tissue repair were quantified by quantitative reverse-transcription polymerase chain reaction. Finally, H&E staining was used to determine the histological structure of muscle in the treatment and placebo groups.

RESULTS

The rates of acute limb ischemia in the PBS and ADSC-Exo injection groups were 66% (9/16 mice) and 43% (6/14 mice), respectively. The mobility of the limbs 28 days after surgery was significantly different between the ADSC-Exo treatment group (41 ± 1 times/10 s) and the PBS group (24 ± 1 times/10 s; n = 3; p < 0.05). Peripheral blood oxygen saturation 21 days after treatment was 83.83% ± 2.02% in the PBS group and 83% ± 1.73% in the ADSC-Exo treatment group, and the difference was not statistically significant (n = 3, p > 0.05). On day 7 after treatment, the time required to stain the toes after trypan blue injection was 20.67 ± 12.5 s and 85 ± 7.09 s in the ADSC-Exo and PBS groups, respectively (n = 3, p < 0.05). On day 3 after the operation, the expression of genes promoting angiogenesis and muscle remodeling, such as Flk1, Vwf, Ang1, Tgfb1, Myod, and Myf5, was increased 4-8 times in the ADSC-Exo group compared with the PBS group. No mice in either group died during the experimental period.

CONCLUSIONS

These results revealed that intravenous infusion of human ADSC-derived exosomes is a safe and effective method to treat ischemic disease, especially hindlimb ischemia, by promoting angiogenesis and muscle regeneration.