Catheter-Directed Mechanical Thrombolysis in Thromboembolic Disease

PICHON RIVIERE, A.; AUGUSTOVSKI, F. A.; GARCIA MARTI, S.; GLUJOVSKY, D.; ALCARAZ, A.; LOPEZ, A.; BARDACH, A.; CIAPPONI, A

Documento de Evaluación de Tecnologías Sanitarias

IECS

Año: 2012 p. 1 - 30

1668-2793

Thromboembolic disease consists of two conditions: Pulmonary ThromboEmbolism (PTE) and Deep Vein Thrombosis (DVT). In the U.S.A, it has a prevalence of 1.92 every 1,000 person-year and is common cause of cardiovascular disease. Both PTE and DVT are frequently underdiagnosed. However untreated acute proximal DVT results in PTE in 33-50% of patients and untreated PTE may slowly recur or progress to a fatal outcome.DVT is commonly treated by anticoagulation but in cases of iliofemoral DVT, where post-thrombotic morbidity is high, thrombolysis is also used. In addition, patients with PTE are usually anti-coagulated. However, in those cases where PTE is massive, the use of thrombolytic drugs is recommended.In some patients, systemic thrombolysis is contraindicated due to its adverse effects such as hemorrhages. In these patients, the use of catheter-directed thrombolysis, which includes local administration of thrombolytic drugs, catheter-directed mechanical thrombolysis or a combination of both, is recommended.TechnologyThrombolysis is a procedure where radiological images, a catheter, a medical device that mechanically helps to dissolve thrombi and, eventually anti-thrombotic drugs, are used. There are several devices used for catheter-directed mechanical lysis. The technology would have a faster mechanism of action than pharmacological thrombolysis.The catheter is percutaneously and intravenously inserted and is advanced to the point of obstruction. The thrombus is lysed by releasing thrombolytic drugs only, by means of a device (mechanical thrombolysis) or using both modalities. General anesthesia or deep sedation is used. To fragment the clot, rheolytic thrombectomy, clot aspiration or a Greenfield- embolectomy catheter are used. Usually, this is carried out in the Cath Lab or in the Radiology Unit.PurposeTo assess the evidence available on the efficacy, safety, and issues related to the coverage policies of catheter-directed mechanical thrombolysis for the treatment of thromboembolic disease.MethodsA bibliographic search was carried out on the main bibliographic databases and also in DARE, NHS EED, on Internet general search engines, in health technology evaluation agencies and health sponsors. Priority was given to the inclusion of systematic reviews; controlled, randomized clinical trials (RCTs); health technology assessments and economic evaluations; clinical practice guidelines and coverage policies of other health systems.ResultsOne systematic review on PTE and another one on DVT, one RCT on PTE published after the review and two clinical practice guidelines were found. Also, data from coverage policies from surveyed health sponsors are also reported.Pulmonary ThromboembolismOne systematic review published in 2009 identified 35 non controlled studies. A total of 546 patients received catheter-directed treatment as first line together with heparin anticoagulation. In thirty-three percent of the cases only mechanical thrombolysis was used (69% of the cases used embolus fragmentation using a pig-tail rotation catheter) and the rest also used local antithrombotic drugs. The rate of success (patients with hemodynamic stabilization, hypoxia resolution and survival at discharge) was 86.5% (95% CI 82.2% - 90.2%). The rate of success in those studies with patients who also received local antithrombotic drugs was 91.2% (95% CI 86.3% - 95.1%). The analysis of the studies shows that there might be some bias in the publication; therefore, these figures might be overestimated. The rates of minor complications were 7.9%, with rates of major complications of 2.4% (mostly with hemorrhages requiring transfusion, and death). It is worth mentioning now the rates of major hemorrhagic complications published in other studies where systemic thrombolysis or anticoagulation were used, being 10.4% and 6.4% respectively, mortality rates of 6.2% and 12.7% respectively for massive PTE.Deep Vein ThrombosisOne systematic review published in 2011 assessed 16 retrospective case series where percutaneous mechanical thrombectomy was used in 481 patients. Thrombus lysis with high permeability (Grade II and III) was observed in 83-100% of cases and <1% PTE progression. Four to fourteen percent of patients had hemorrhagic complications requiring transfusions. The rates of complete thrombus lysis in lower extremity DVT published in other studies where systemic thrombolysis or anticoagulation was used were 43.4% and 17.3% respectively, with rates of post-thrombotic syndrome of 47.5% and 65%, and 10% and 7.9% with bleeding. At present, there are several ongoing RCTs.Clinical practice guidelines:In 2008, the U.S. American College of Chest Physicians (ACCP) recommended thrombolysis in patients with PTE and hemodynamic involvement, suggesting the use of systemic thrombolysis or pharmacomechanical thrombolysis in patients at high risk of bleeding or when the patient´s condition is so critical that systemic thrombolysis would take too long to be effective. In the case of DVT, the use of catheter-directed thrombolysis is recommended in patients with proximal acute and extensive DVT at low risk of bleeding in order to reduce the acute symptoms and post-thrombotic morbidity. Also, pharmacomechanical thrombolysis instead of catheter-directed thrombolysis alone is suggested. On the other hand, the U.S. American Heart Association (AHA) published some clinical practice guidelines with similar recommendations.Some of the health sponsors surveyed agree that mechanical thrombolysis in patients with PTE or DVT should be considered experimental. Others do not mention the use of this technology in these clinical settings.ConclusionsThe evidence found on the use of mechanical thrombolysis in DVT and PTE is of poor methodological quality since it comes from non controlled studies only.Despite the low quality of the evidence, clinical practice guidelines found recommend the use of mechanical thrombolysis in patients with massive PTE and contraindication for systemic thrombolysis. However, the health sponsors surveyed do not cover this technology. Caution should be exerted since these studies have multiple biases resulting from both design and patient screening and publication.As regards DVT and despite the evidence is also of poor quality, the guidelines suggest catheter-directed thrombolysis in selected patients with acute extensive and proximal DVT.Studies with other methodological designs are required to support the data presented in this document with more scientific evidence.