The quantitative benefit of isolated, segmental, pharmacomechanical thrombolysis (ISPMT) for iliofemoral venous thrombosis

Catheter-Directed Thrombolysis Protocols for Deep Venous Thrombosis of the Lower Extremities-A Systematic Review and Meta-analysis

OBJECTIVE

 To summarize characteristics, complications, and success rates of different catheter-directed thrombolysis (CDT) protocols for the treatment of lower extremity deep venous thrombosis (LE-DVT).

METHODS

 A systematic review using electronic databases (MEDLINE, Scopus, and Web of Science) was performed to identify randomized controlled trials and observational studies related to LE-DVT treated with CDT. A random-effects model meta-analysis was performed to obtain the pooled proportions of early complications, postthrombotic syndrome (PTS), and venous patency.

RESULTS

 Forty-six studies met the inclusion criteria reporting 49 protocols (n = 3,028 participants). In studies that addressed the thrombus location (n = 37), LE-DVT had iliofemoral involvement in 90 ± 23% of the cases. Only four series described CDT as the sole intervention for LE-DVT, while 47% received additional thrombectomy (manual, surgical, aspiration, or pharmacomechanical), and 89% used stenting.Definition of venogram success was highly variable, being the Venous Registry Index the most used method (n = 19). Among those, the minimal thrombolysis rate (<50% lysed thrombus) was 0 to 53%, partial thrombolysis (50-90% lysis) was 10 to 71%, and complete thrombolysis (90-100%) was 0 to 88%. Pooled outcomes were 8.7% (95% confidence interval [CI]: 6.6-10.7) for minor bleeding, 1.2% (95% CI: 0.8-1.7%) for major bleeding, 1.1% (95% CI: 0.6-1.6) for pulmonary embolism, and 0.6% (95% CI: 0.3-0.9) for death. Pooled incidences of PTS and of venous patency at up to 1 year of follow-up were 17.6% (95% CI: 11.8-23.4) and 77.5% (95% CI: 68.1-86.9), respectively.

CONCLUSION

 Assessment of the evidence is hampered by the heterogeneity of protocols, which may be reflected in the variation of PTS rates. Despite this, CDT is a low-risk treatment for LE-DVT.

Pharmacomechanical Thrombectomy Versus Catheter-Directed Thrombolysis for Iliofemoral Deep Vein Thrombosis: A Meta-Analysis of Clinical Trials

Early catheter-directed thrombolysis (CDT) for deep vein thrombosis (DVT) can reduce postthrombotic morbidity. Pharmacomechanical thrombolysis (PMT) is a new therapy that can be selected for the treatment of iliofemoral deep vein thrombosis (IFDVT). We performed a meta-analysis of clinical trials comparing PMT versus CDT for treatment of acute IFDVT. Literature on this topic published between January 1, 1990, and June 1, 2018, was identified using PubMed, Embase, Cochrane Library, and Web of Science. Six trials were included in the meta-analysis. Compared to CDT, PMT significantly reduced the Villalta score ( P = .007; I² = 0%), thrombus score ( P = .01; I² = 0%), the duration in the hospital ( P = .03; I² = 64%), and thrombolysis time ( P < .00001, I² = 0%). There was no significant difference in valvular incompetence events ( P = .21; I² = 0%), minor bleeding events ( P = .59; I² = 0%), stent events ( P = .09; I² = 24%), and clot reduction grade I events ( P = .16; I² = 43%) between PMT and CDT. Subgroup analysis was performed by dividing the clot reduction grade I events group into PMT plus CDT versus CDT group and significant differences were found ( P = .03, I² = 0%) as well as for PMT alone versus CDT group ( P = .88, I² = 37%). This meta-analysis shows that PMT reduces the severity of postthrombotic syndrome (PTS), thrombus score, duration in hospital, and thrombolysis time compared to CDT. More specifically, PMT plus CDT reduces clot reduction grade I events. No significant difference in valvular incompetence events, stent events, and minor bleeding events were found when PMT was compared to CDT.

Thrombolysis for Management of Phlegmasia Cerulea Dolens in the First Trimester of Pregnancy

BACKGROUND

Pregnancy is a hypercoagulable state associated with a fivefold increase in the risk of venous thromboembolism. Thrombolysis is the preferred level of care for patients with acute iliofemoral deep vein thrombosis (DVT); however, most studies exclude pregnant patients, highlighting the lack of data regarding the efficacy and safety of thrombolytic therapy for mother and fetus.

METHODS

We describe the successful use of thrombolytic therapy in conjunction with ultrasound to remove a large ileofemoral DVT in a first-trimester patient with phlegmasia cerulea dolens. The procedure was performed safely for both mother and fetus.

RESULTS

No radiation or contrast dye was used, and intravascular ultrasound confirmed patency of the entirety of the venous system. She delivered a healthy term baby after the procedure and had no further sequalae.

CONCLUSION

Thrombolysis with intravascular ultrasound may be considered in first-trimester pregnant patients with threatened limb due to DVT.

Clinical outcomes after direct and indirect surgical venous thrombectomy for inferior vena cava thrombosis

OBJECTIVE

Inferior vena cava thrombosis is rare, but patients are at high risk for development of a post-thrombotic syndrome (PTS) in the long term. Surgical approaches include indirect transfemoral venous thrombectomy (iTFVT) and direct open venous thrombectomy (dOVT). This study reports patient outcomes after iTFVT and dOVT for inferior vena cava thrombosis covering a 25-year follow-up period.

METHODS

The study period was from January 1, 1982, to December 31, 2013. Data were retrieved from archived medical records, and patients were invited for a detailed phlebologic follow-up examination (DPFE). Health-related quality of life was assessed with the 36-Item Short Form Health Survey questionnaire. Patient survival, patency rates, and freedom from PTS were calculated using Kaplan-Meier estimation with log-rank testing. The χ² test with Yates continuity correction and logistic regression analysis were applied to identify associations between risk factors or coagulation disorders, mortality, and PTS.

RESULTS

Complete medical records were available for 152 patients. Patients' 5-year survival was 91% ± 3%, and 5-year primary and secondary patency rates were 80% ± 3% and 94% ± 2%. Freedom from PTS after 25 years was 84% ± 6%. No differences for patient survival, patency rates, or freedom from PTS were identified between iTFVT, dOVT, and a combination of both procedures. Antithrombin III deficiency was the most common coagulation disorder, and patients' physical function and social function were impaired compared with those found in German normative data (P < .05). No risk factor or coagulation disorder was associated with survival or PTS.

CONCLUSIONS

Open surgical venous thrombectomy is safe and delivers satisfying short- and long-term outcomes compared with endovascular approaches. It remains valuable for patients who are not eligible for other interventional therapies.

Pharmacologic and Pharmacomechanical Thrombolysis for Acute Deep Vein Thrombosis: Focus on ATTRACT CME

Systemically delivered pharmacologic thrombolysis for acute deep vein thrombosis long ago gave way to catheter delivery of plasminogen activators within the clot. This simple concept resulted in markedly improved efficacy and safety. In an effort to accelerate thrombus dissolution or extraction, mechanical methods were developed, but the initial techniques left substantial residual thrombus that required subsequent catheter-directed thrombolysis (CDT). It was soon observed that combined pharmacomechanical thrombolysis was more effective than either one alone. Randomized trials of catheter-based strategies for thrombus removal have documented objective benefit, including improved patency, preserved valve function, and reduced post-thrombotic syndrome. The largest randomized study is the ATTRACT trial published at the end of 2017. Although mild post-thrombotic syndrome (PTS) was no different between the pharmacomechanical catheter-directed thrombolysis (PCDT) and control groups, acute pain and swelling and moderate-to-severe PTS were reduced with PCDT. Additional analyses from this robust data set are forthcoming.

Radiation- and contrast medium-free catheter-directed thrombolysis for early pregnancy-related massive iliocaval deep venous thrombosis

Catheter-directed thrombolysis for iliofemoral deep venous thrombosis (DVT) aims to reduce acute leg symptoms and to prevent the post-thrombotic syndrome. There are no data from controlled trials in pregnant patients. Reports of thrombolysis for treatment of DVT during pregnancy are scarce. Pregnancy is considered a relative contraindication to thrombolytic therapy because of the risk of bleeding and concerns about the effects of radiation exposure on the fetus. We report on a catheter-directed thrombolysis procedure without radiation and contrast medium exposure in a first-trimester pregnant patient with massive iliofemoral DVT and free-floating thrombus extending to the suprarenal inferior vena cava.

Consensus among Chinese experts on standard interventional therapy for deep venous thrombosis of lower extremity (second edition)

This is an update on the first edition of the expert consensus. This document discusses the indications and contraindications of interventional treatment methods for deep venous thrombosis such as anticoagulation, catheter-directed thrombolysis, percutaneous mechanical thrombectomy, percutaneous transluminal angioplasty and stent implantation. The operational procedures, considerations, preoperative management, and prevention of complications were also updated, supplemented, and revised. Emphasis is placed on the interventional treatment of acute and subacute deep venous thrombosis to effectively reduce the incidence of post-thrombosis syndrome.

What is the definition of successful lysis: reporting standard?

Deep vein thrombosis, and the resultant development of post-thrombotic syndrome, is a significant health issue. Recent evidence demonstrates that the severity of post-thrombotic syndrome symptoms is directly related to the level of venous thrombosis and following treatment these subsequent symptoms are inversely related to the degree of thrombus removal. If we can improve, and preferably standardise the terminology associated with pre-treatment assessment of thrombus load and post-treatment success of thrombus removal techniques, we should then be able to choose more tailor-made techniques to greater benefit our patients. A number of scoring systems have been devised for the assessment of venous thrombus burden, with a majority impractical for everyday usage. In order to provide a more practical solution, the lower extremity thrombosis classification has been developed, using information on anatomical location for venous thrombus combined with a clinical indicator as to the likely sequelae. Anatomical success following venous thrombolysis can be defined by assessing restoration of anterograde flow in the treated vein or the percentage degree of thrombolysis, using venography. The second option is the method most frequently utilised, with the Venous Registry grading system applied. Data from recent trials have given us conflicting and confusing data mainly because we are not using standardised terminology. We urgently need to agree on a standard method of description of thrombus removal before stent placement which also incorporates the likely clinical impact of the area involved in the thrombosis.

Inferior Vena Cava Thrombosis

Thrombosis of the inferior vena cava (IVC) is an under-recognized entity that is associated with significant short- and long-term morbidity and mortality. In absence of a congenital anomaly, the most common cause of IVC thrombosis is the presence of an unretrieved IVC filter. Due to the substantial increase in the number of IVC filters placed in the United States and the very low filter retrieval rates, clinicians are faced with a very large population of patients at risk for developing IVC thrombosis. Nevertheless, there is a paucity of data and societal guidelines with regards to the diagnosis and management of IVC thrombosis. This paper aims to enhance the awareness of this uncommon, but morbid, condition by providing a concise, yet comprehensive, review of the etiology, diagnostic approaches, and treatment strategies in patients with IVC thrombosis.

Basic data related to thrombolytic therapy for acute venous thrombosis

BACKGROUND

Treatment guidelines for thrombolysis in iliofemoral deep venous thrombosis (DVT) are based on a limited number of observational and prospective studies. The acute venous thrombosis: thrombus removal with adjunctive catheter-directed thrombolysis (ATTRACT) trial will be the first large, multicenter randomized control trial to evaluate the relative advantages of several current treatment strategies. The objective of this study was to summarize the existing data that inform the use of catheter-directed thrombolysis (CDT) or pharmacomechanical thrombectomy in the management of acute iliofemoral DVT.

METHODS

A search of the current literature was done using PubMed, Ovid, and Cochrane databases for all available articles published up to December 2013.

RESULTS

Of those studies, which included at least 25 patients, 19 case series were identified from 1996 to 2012. Treatment groups included anticoagulation, surgical thrombectomy, pharmacomechanical thrombectomy, and CDT. Cases observed in each ranged from 26 to 101. Three studies were identified which derived data from national multicenter registries. Only 2 randomized control trials were identified from 2002 to 2012. Both support the use of CDT over anticoagulation alone for treatment of iliofemoral DVT.

CONCLUSIONS

Present treatment guidelines for acute iliofemoral DVT have been in flux and are derived from a relatively small amount of clinical data. They are summarized here in anticipation of results from the ongoing ATTRACT trial.

Catheter-directed thrombolysis for iliofemoral deep vein thrombosis

BACKGROUND

Recent international guidance recommends the use of catheter-directed thrombolysis (CDT) in selected patients with symptomatic iliofemoral deep vein thrombosis (DVT). The aim of this study was to estimate the potential increase in workload as a result of this recommendation.

METHODS

Using the radiology database, a review was performed of all DVTs diagnosed between August 2010 and February 2012 at a large tertiary referral hospital. The National Institute for Health and Clinical Excellence and American College of Chest Physicians guidance was applied retrospectively to this cohort, using case-note review by two independent clinicians to determine which patients would have been suitable for CDT.

RESULTS

Some 563 patients had DVT confirmed radiologically over the 18-month interval. Fifty-three of the 128 patients with iliofemoral DVT would have been eligible for intervention with CDT, equivalent to 4·4 patients per 100 000 per year. Only eight (15 per cent) of the 53 were actually referred to vascular services for treatment. All eight patients had successful CDT, which involved a stay in critical care for monitoring (median 2 (range 1-3) sessions).

CONCLUSION

Vascular units should be prepared for a major increase in the requirement for CDT for iliofemoral DVT. This increase will affect inpatient beds, the interventional radiology suite, critical care and interhospital referrals.

Management of proximal deep vein thrombosis

Iliofemoral DVT constitutes approximately 20-25% of lower limb DVT and represents a specific subgroup of patients at highest risk for post-thrombotic syndrome (PTS). Anticoagulation alone has no significant thrombolytic activity and has not impact on PTS prevention. Early thrombus removal has reduced PTS in uncontrolled reports and reviews but major trials are awaited. The optimal timing for treatment appear to be thrombus <2 weeks old and, methods for thrombus removal include direct open or suction thrombectomy, catheter directed thrombolysis (CDT), with or without percutaneous mechanical thrombectomy (PMT) devices. Three principle types of PMT device are in use (rotational, rheolytic and ultrasound enhanced devices) and are combined with CDT in pharmocomechanical thrombolysis (PhMT) to enhance early thrombus removal. These devices have individual device specific attributes and side effects that are additional to the bleeding complications of thrombolysis. A number of additional interventions may be utilised to the improve results of CDT and PhMT. IVC filter deployment to reduce periprocedural PE, is supported by little evidence unless an indication for its use already exists. However, balloon venoplasty and vein stents undoubtedly vein patency after treatment. Early thrombus removal comes with additional upfront costs derived from devices, imaging and critical care bed usage. However, significant potential savings from reduction in PTS and rethrombosis rates may reduce overall societal costs. This review focuses on iliofemoral thrombosis, however, the less commonly encountered but clinically important subclavian vein thrombosis is also discussed.

The Future of Deep Venous Thrombosis and Post-thrombotic Syndrome in 2020

This manuscript addresses six major issues involving deep venous thrombosis (DVT) and post-thrombotic syndrome. Prevention will likely see modest advances in pharmacological therapy mainly by extending prophylaxis in high-risk patients. More notable advances will be observed in mechanical means of prophylaxis, focusing on sustained application of devices that can move larger volumes of blood. Silent, large-vein thrombi continue to place patients at risk for fatal pulmonary embolism. Improved imaging techniques will permit us to identify these patients over the next eight years. In many of those patients, vena caval interruption will be required. Elimination of high-risk filters and the production of improved filters placed through low-profile systems with antithrombotic agents bound to their surface will improve the short- and long-term results for inferior vena cava filters. The long-term management of DVT will focus on establishing appropriate duration for the individual patient and will see the evolution towards direct Xa and Ha inhibitors. Patients with extensive DVT will more commonly receive treatment strategies designed to eliminate thrombus and restore patency. This will substantially reduce post-thrombotic morbidity and reduce recurrence. Post-thrombotic syndrome will see greater attention towards treating the intraluminal fibrosis, thereby eliminating post-thrombotic venous obstruction. Unfortunately, neovalves will still be searching for the appropriate application.

pharmacomechanical Thrombectomy for Early Thrombus Removal

Objectives:

To review the current literature on the outcomes of pharmacomechanical thrombectomy (PMT) for early thrombus removal in patients with venous thromboembolism (VTE).

Methods:

We searched the MEDLINE database and performed a manual search of the references of selected articles to select reports reporting the outcomes of PMT alone and PMT compared to catheter-direct thrombolysis (CDT). Outcomes of interest included clot lysis rate, incidence of pulmonary embolism, major bleeding, recurrent deep vein thrombosis, number of venograms needed and amount of lytic utilized.

Results

We found nine articles that reported outcomes of PMT. Three devices were utilized for PMT, the Angiojet, Trellis and Helix. Different thrombolytics were used to facilitate thrombus removal including urokinase, reteplase, tecneteplase, and tissue plasminogen activator (t-PA). Complete and partial thrombus removal were achieved in up to 84% and 64% and 81% and 59% of the limbs treated with PMT and CDT alone, respectively. Data on PE and bleeding risk after PMT compared to CDT are scarce. The duration of the thrombolysis process, amount of lytics and number of venograms were substantially reduced in the patients who had PMT compared to those who underwent CDT alone. Two articles evaluated the obstacles that limit the indication of PMT in patients with VTE.

Conclusion:

VTE is a prevalent burden in Western societies. The rationale of early thrombus is to reduce valvular damage and improve venous patency in order to reduce the risk of PTS. PMT is a feasible, safe and faster alternative to expedite the thrombolysis process in patients with VTE.

Pharmacomechanical Thrombolysis for Phlegmasia Cerulea Dolens

Phlegmasia cerulea dolens (PCD) is limb-threatening. Traditional treatments are very morbid. We examine the efficacy of percutaneous treatment of PCD. Between May 2005 and September 2008, we treated 21 limbs in 20 patients with lower extremity PCD who were candidates for thrombolysis. Diagnosis was by clinical examination and duplex ultrasound. Catheter access to the deep venous system was obtained through a popliteal vein. Therapy used pulse spray thrombolysis with tissue plasminogen activator (tPA). Infusion catheters and adjunctive percutaneous techniques were used as indicated. Postoperatively, patients were treated with systemic anticoagulation, compression hose, and interval follow-up. Limbs were graded according to the CEAP classification. Twenty patients (13 male) were treated with a mean age of 55.8 years. Nine patients had hypercoagulable states, four May Thurner syndrome, three a history of cancer, one postcolon resection, one acute myocardial infarction, and one postfemoral vein puncture. All patients had resolution of PCD without the need for open surgery. The initial tPA dose was 19.5 mg with pulse spray thrombolysis. Infusion catheters were required in 18 patients and used for 16.1 hours (range, 8 to 36 hours) until complete thrombolysis. Venous angioplasty was necessary in 14 patients with nine of these requiring venous stents. One patient required above-knee amputation despite successful treatment of her PCD. Mean follow-up was 10.7 months (range, 1 to 39 months). All patients demonstrated no or minimal residual thrombus and intact valvular function and a mean clinical CEAP score of 2.4. Percutaneous treatment of PCD produced excellent results with minimal morbidity.

The persistent thrombus: complications, diagnosis, and novel treatment intervention

OBJECTIVE

To review the findings and discuss the implications of the topic of pharmacomechanical thrombolysis in pediatric patients with persistent thrombus.

DESIGN

A pediatric case presentation with a brief literature review on treatment of venous thrombosis and pharmacomechanical thrombolysis.

INTERVENTIONS

None.

MAIN RESULTS

Thrombotic events refractory to standard medical and surgical care remain a life-threatening clinical challenge in the pediatric population. Research on persistent deep venous thrombosis and treatment modalities is limited. We present a pediatric patient with a history of malignant osteosarcoma who was diagnosed with deep venous thrombosis. Despite appropriate anticoagulation therapy, the thrombus remained persistent. Pharmacomechanical thrombolysis was utilized and proved to be an effective method in providing diagnosis and treatment.

CONCLUSION

Pharmacomechanical thrombolysis is a valuable and effective method in providing diagnosis and treatment of persistent thrombus.

Embolization during treatment of deep venous thrombosis: incidence, importance, and prevention

The standard of care for the treatment of acute deep venous thrombosis (DVT) is anticoagulation, which often prevents the formation of new thrombus and reduces the risk of pulmonary embolism (PE) but fails to eliminate the clot burden. Patients who have thrombus remaining in their deep venous system despite therapeutic anticoagulation are at high risk for developing symptoms of the postthrombotic syndrome, a debilitating condition that adversely affects their quality of life. Strategies of thrombus removal for acute DVT, such as operative thrombectomy, catheter-directed thrombolysis, and pharmacomechanical techniques, are designed to avoid postthrombotic morbidity by restoring patency to the deep veins, but there is concern that these techniques may result in fragmentation of clot and pulmonary embolization. Careful patient evaluation before treatment is essential for preventing complications and often reveals asymptomatic pulmonary emboli in as many as 50% of patients. Nonobstructive or free-floating thrombus in the vena cava is a risk factor for procedure-related embolization and is frequently an indication for the use of vena caval filtration. A review of the literature on acute DVT treated by anticoagulation alone or with strategies of thrombus removal reveals that pulmonary embolization is an infrequent occurrence. Treatment with anticoagulation alone, however, increases the risk of patients developing symptoms of the postthrombotic syndrome, whereas thrombus removal strategies reduce postthrombotic morbidity without increasing the risk of embolization.

Thrombolysis for deep venous thrombosis

The key questions addressed in this summary are whether clot removal should be part of the preferred therapy for patients with acute deep venous thrombosis (DVT), and whether there is evidence that a strategy of thrombus removal offers better outcomes for patients than anticoagulation alone. Evidence is defined as an outward sign or something that furnishes proof. Evidence in medicine is not limited to direct, blinded comparisons of one form of treatment compared with another but rather the body of knowledge that provides insight to clinicians to offer patient care. Evidence-based medicine follows from information available to form the foundation for the use of a treatment for a specific disease. Reports of strategies of thrombus removal for acute DVT, especially in patients with iliofemoral DVT, consistently demonstrate improved outcomes relative to postthrombotic morbidity. This summary reviews the evidence supporting this strategy as the preferred initial management of patients with extensive proximal DVT.

Catheter-directed thrombolysis of lower limb thrombosis

Late complications of thrombosis of the deep veins in the region between the popliteal vein termination and the confluence of the common iliac veins and inferior vena cava (suprapopliteal deep-vein thrombosis) are common and often unrecognized by those responsible for the initial management. Pharmacomechanical-assisted clearance of the thrombus at the time of first presentation provides the best opportunity for complete recovery with preservation of normal venous valve function and avoidance of recurrent deep-vein thrombosis and postthrombotic syndrome. Recent interventional radiology methods provide for rapid and complete thrombolysis even in some patients in whom thrombolysis was previously considered contraindicated. This review describes the methods, safety, and efficacy of acute interventional treatment of suprapopliteal deep-vein thrombosis.