Eligibility of Patients with Chronic Limb Threatening Ischemia for Deep Venous Arterialization

ICAM1 blockade improves ischemic muscle reperfusion in diabetic mice

BACKGROUND

Chronic Limb-Threatening Ischemia (CLTI) represents the most advanced stage of Peripheral Artery Disease (PAD) and is associated with dire prognosis, characterized by a substantial risk of limb amputation and diminished life expectancy. Despite significant advancements in therapeutic interventions, the underlying mechanisms precipitating the progression of PAD to CLTI remain elusive.

METHODS

Considering diabetes is one of the main risk factors contributing to PAD exacerbation into CLTI, we compared hind limb ischemia recovery in HFD STZ vs. non-HFD STZ mice to identify new mechanisms responsible for the exacerbation of PAD.

RESULTS

We used three different mouse models of diabetes and found that blood flow recovery in HFD STZ mice is altered only from day 14 post-surgery. Consistent with this kinetics, we found that angiogenesis and myogenesis which typically occur between day five and day 14 post-surgery are not impaired in mice in which diabetes was induced by a high fat diet and streptozotocin injections (HFD STZ mice). On the contrary, we found that capillary functionality e.i. acquisition of functional intercellular junctions and immune quiescence is impaired in HFD + STZ mice. Notably, 28 days after hind limb ischemia surgery, HFD + STZ mice display significantly increased capillary permeability to IgG and significantly increased levels of ICAM1. This was associated with an increased macrophage infiltration and an impaired myocyte differentiation. Importantly, we used ICAM1-blocking antibodies to demonstrate that increased ICAM1 expression in HFD + STZ mice decreases white blood cell circulation velocity within the microcirculation, which impairs its perfusion. Notably anti-ICAM1 therapy did diminish macrophage infiltration and oxidative stress but not myopathy suggesting that myopathy characterized by small myocytes expressing higher level of MYH2 could be responsible for microangiopathy.

CONCLUSION

ICAM1 expression by the microvasculature impairs ischemic muscle reperfusion in HFD + STZ mice. Importantly, the increase in blood flow between day 14 and day 90 post-HLI surgery is not associated with an increased capillary density but with an improved functionality of capillaries.

Short-Term Outcomes and Efficacy of Percutaneous Deep Vein Arterialization for No-Option Critical Limb Ischemia: A Systematic Review and Meta-Analysis

BACKGROUND

Percutaneous deep vein arterialization (pDVA) is considered a treatment modality in patients with no-option critical limb ischemia. However, there is still a paucity of evidence regarding its safety and efficacy.

DATA SOURCES

MEDLINE (via PubMed), Embase and Web of Science databases as well as the CENTRAL registry up to the end of June 2023.

METHODS

This review adhered to the PRISMA guidelines (PROSPERO registration no. CRD42023445171). The risk of bias was assessed using the methodological index for non-randomized studies (MINORS). Primary endpoints included technical success, overall survival and limb salvage during the follow-up. Amputation-free survival at 30 days, 6 months and 1 year as well as complete wound healing, major adverse limb events and reintervention were investigated as secondary outcomes.

RESULTS

Five observational studies, comprising 208 patients (142 Rutherford class 5/77 Rutherford class 6), were included. MINORS revealed a low risk of bias. The meta-analysis reached a pooled technical success rate of 96.2% (95% CI: 91.5-98.4), an overall survival of 82.8% (95% CI: 70.5-95.2) and a limb salvage rate of 77.2% (95% CI: 65.2-89.1) during the follow-up. The amputation-free survival at 30 days, 6 months and 1 year was 87.8%, 68.7% and 65.6%, respectively. Furthermore, pDVA resulted in a complete wound healing rate of 53.4% (95% CI: 30.3-76.5). The pooled reintervention rate was as high as 46.7% (37.1-56.3%).

CONCLUSIONS

PDVA seems a feasible bail-out strategy for patients with no option for routine treatment of CLTI. However, due to the small number of studies, the strength of the evidence is low.