Retrospective analysis of Rt-pa thrombolysis combined with PGE1 in patients with peripheral arterial occlusions

Catheter Directed Thrombolysis for Not Immediately Threatening Acute Limb Ischaemia: Systematic Review and Meta-Analysis

OBJECTIVE

This systematic review and meta-analysis reports the outcomes of catheter directed thrombolysis (CDT) in patients with not immediately threatening (Rutherford I) acute lower limb ischaemia (ALI).

DATA SOURCES

PubMed, Embase, and the Cochrane Library.

REVIEW METHODS

A systematic search of PubMed, Embase, and the Cochrane Library was performed to identify observational studies and trials published between 1990 and 2022 reporting on the results of CDT in patients with Rutherford I ALI. A meta-analysis was performed using a random effects model with 95% confidence intervals (CIs). The outcomes of interests were treatment duration, angiographic success, bleeding complications, amputation and mortality rates, primary and secondary patency, and functional outcome expressed as pain free walking distance.

RESULTS

Thirty-nine studies were included, comprising 1 861 patients who received CDT for not immediately threatening ALI. Funnel plots showed an indication of publication bias, and heterogeneity was substantial. Data from 5 to 13 studies were included in the meta-analysis. The pooled treatment duration was 2 days (95% CI 1 - 2), with an angiographic success rate of 80% (95% CI 73 - 86) and a 30 day freedom of amputation rate of 98% (95% CI 92 - 100). The major bleeding rate was 5% (95% CI 2 - 14), with a 30 day mortality rate of 3% (95% CI 1 - 5). The amputation free survival rate was 71% (95% CI 62 - 80) at the one year and 63% (95% CI 51 - 73) at the three year follow up. Long term patency rates were retrieved from four studies: 48% at one year (95% CI 27 - 70). No data could be retrieved on patient walking distance.

CONCLUSION

Although CDT in the treatment of not immediately threatening ALI showed high angiographic success, the long term outcomes were relatively poor, with low patency and a substantial risk of major amputation. Further research is required to interpret the outcome of CDT in the context of potential confounders such as age and comorbidities.

Current trends in thrombolysis: implications for diagnostic and interventional radiology

Current trends in thrombolysis are of relevance to both diagnostic and interventional radiologists. In addition to the traditional use of thrombolytic therapy in conditions such as peripheral arterial thrombosis, venous thrombosis and pulmonary embolic disease, more recent interest has focused on the potential use of thrombolysis in acute stroke. There will be significant implications for the provision of radiological services if current trials show a favourable outcome for thrombolysis in stroke. This article looks at a range of conditions in which thrombolysis may be useful, on the strength of currently available evidence. Future trends will depend on the outcomes of the current trials.

An hypothesis on the consolidation and PGE1-induced deconsolidation of a platelet plug

Consolidation is the final stage in haemostasis in which a platelet plug blocking a bleeding area of a vessel: (a) becomes impermeable to circulating plasma proteins and (b) contracts to resist blood pressure.

HYPOTHESIS

The impermeabilization step of consolidation is accomplished through fluid uptake by the platelets from a hydrated intercellular glue formed during thrombin activation. Dehydration occurs through inhibition of the Na+,K+-ATPase of platelets with sodium and water uptake. However, and uniquely, due to the high cellular density of the platelet plug, access of peripheral plasma fluids to the plug is limited forcing the platelets to take up preferentially the fluid of interplatelet space. The increased adhesion properties of the dehydrated glue simultaneously furthers a decreased hydraulic permeability and an improved coupling of the contractile forces among platelets. In 'Deconsolidation', the fluid uptake process can be reversed and amplified by agents that increase cAMP, reactivating the Na+,K+-ATPase and expressing CFTR or equivalent Cl- secretory channels that force the extrusion of fluid from the platelets, with rehydration of the intercellular polymer and a large increase in the interplatelet space.

Thrombolytic therapy: clinical applications

The therapeutic use of thrombolytic agents is the result of the increasing understanding of the pathophysiologic mechanisms underlying normal and deranged thrombosis and fibrinolysis. Plasminogen activators capable of increasing the production of plasmin exhibit considerable efficacy in the treatment of a variety of arterial and venous thrombotic disorders. The ideal thrombolytic agent has not been developed, but the desired clinical result of rapid opening of the thrombosed vessel without reocclusion, without activation of systemic fibrinogenolysis, and without a risk of hemorrhage are defined. Clinical studies clearly demonstrate that the addition of a variety of adjunctive agents to available thrombolytics enhances benefit without inordinate risk. The addition of intravascular angioplasty and stenting to thrombolysis increases the potential long-term benefit. Newer thrombolytic agents and new protocols for the use of existing therapies offer the promise of saving many who would otherwise succumb to coronary or cerebral arterial thrombosis or to venous thromboembolism.

Thrombolytic therapy

The therapeutic use of thrombolytic agents is the natural result of the increasing understanding of the pathophysiologic mechanisms underlying normal and deranged thrombosis and fibrinolysis. Plasminogen activators capable of increasing the production of plasmin exhibit considerable efficacy in the treatment of a variety of arterial and venous thrombotic disorders. The ideal thrombolytic agent has yet to be developed but the desired clinical result of rapid opening of the thrombosed vessel without reocclusion, without activation of systemic fibrinogenolysis, and without a risk of hemorrhage is well defined. Clinical studies clearly demonstrate that the addition of a variety of adjunctive agents to the available thrombolytics enhances benefit without inordinate risk. The addition of intravascular angioplasty and stenting to thrombolysis increases the potential long-term benefit. Newer thrombolytic agents and new protocols for the use of existing therapies offer the promise of saving many who would otherwise succumb to coronary or cerebral arterial thrombosis or to venous thromboembolism.