Editor's Choice – Factors Associated with Long-Term Outcome in 191 Patients with Ilio-Femoral DVT Treated With Catheter-Directed Thrombolysis

The role and principles of stenting in acute iliofemoral venous thrombosis

Catheter-directed interventions for acute iliofemoral deep venous thrombosis (DVT) have been increasingly used over the past 15 years to target severe symptomatology and prevention of post-thrombotic syndrome incidence or reduce its severity if it were to develop. Aside from successful thrombus removal, adjunctive stents are frequently required to treat an uncovered lesion or significant residual thrombus to ensure quality of life improvement besides retarding DVT recurrence and post-thrombotic syndrome. As the evidence is mounting, the need and role for stenting, as well as the principles of an optimal technique, in the acute DVT setting are now better understood. Accumulating experience appears to favor stenting in the acute setting. The diameter of the stent, the length, the extent of overlapping, and the landing zones are crucial determinants of a successful durable outcome. This article endeavors to guide the interventionalist on stenting when encountering a patient with acute symptomatic iliofemoral DVT with concerns of quality of life impairment.

Experimental multiparametric magnetic resonance imaging characterization of iliocaval venous thrombosis pathological changes

OBJECTIVE

Iliocaval thrombotic obstruction is a challenging condition, especially because thrombus age and corresponding pathological remodeling at presentation are unknown, which directly impacts management. Our aim was to assess the ability of magnetic resonance imaging (MRI) in determining age thresholds of experimentally created inferior vena cava (IVC) thrombosis in pigs.

METHODS

We used a previously described swine model of IVC thrombosis. The animals underwent MRI at baseline, immediately after thrombosis creation, and after a follow-up period extending from 2 to 28 days. Thirteen pigs were divided into three groups according to disease chronicity: acute group (AG; n = 5), subacute group (SAG; n = 4), and chronic group (CG; n = 4), with a mean thrombosis age of 6.4 ± 2.5 days, 15.7 ± 2.8 days, and 28 ± 5.7 days, respectively. A T1-weighted volumetric interpolated breath-hold examination sequence was used to anatomically delineate IVC thrombus as a region of interest. Three other MRI sequences were used to assess the thrombus signal.

RESULTS

The Kruskal-Wallis test showed a statistically significant difference in T1 relaxation times after contrast injection (P = .026) between the three groups of chronicity. The AG (360.2 ± 102.5 ms) was significantly different from the CG (336.7 ± 55.2 ms; P = .003), and the SAG (354.1 ± 89.7 ms) was significantly different from the AG (P = .027). There was a statistically significant difference in native T2 relaxation times (P = .038) between the three groups. The AG (160 ± 86.7 ms) was significantly different from the SAG (142.3 ± 55.4 ms; P = .027), and the SAG was significantly different from the CG (178.4 ± 11.7 ms; P = .004).

CONCLUSIONS

This study highlighted MRI characteristics in a swine model that might have the potential to significantly differentiate subacute and chronic stages from an acute stage of deep vein thrombosis in humans. Further clinical studies in humans are warranted.

CLINICAL RELEVANCE

In addition to providing a better understanding of venous thrombosis remodeling over time, magnetic resonance imaging has the potential to be a tool that could allow us to characterize the composition of venous thrombus over an interval, allowing for a refined analysis of the local evolution of venous thrombosis. We propose a noninvasive and innovative method to characterize different thresholds of chronicity with magnetic resonance imaging features of central deep vein thrombosis of the inferior vena cava experimentally obtained using a totally endovascular in vivo swine model, mimicking human pathophysiology. Being able to determine these features noninvasively is critical for vascular specialists when it comes to choosing between fibrinolytic therapy, percutaneous thrombectomy, or surgical management.

Pharmacomechanical thrombectomy of iliofemoral deep vein thrombosis is associated with a low incidence of post-thrombotic syndrome and perioperative complications

BACKGROUND

Iliofemoral deep venous thrombosis (IFDVT) is associated with an incidence of post-thrombotic syndrome (PTS) of up to 50%. PTS is associated with high morbidity, impaired quality of life and a significant economic burden. The aim of the current study was to assess the impact of a single session pharmacomechanical thrombectomy (PMT), dedicated venous stents and a risk mitigation protocol on the rate of PTS.

METHODS

Between 2015 and 2022, patients presenting with acute or subacute IFDVT treated with the same protocol of single session PMT, dedicated venous stents, and risk-mitigation measures were included. Procedural success rate, complications, stent patency and incidence of PTS were determined.

RESULTS

Of 60 patients (58 ± 19 years; 65% male), the procedural success rate was 93%, with 7% of patients experiencing complications but no long-term sequelae or mortality. Most (n = 52; 87%) patients were stented, including 46% across the inguinal ligament. At 3 months post-procedure, primary, assisted primary and secondary stent patency rates were 89%, 93% and 98%, respectively, with no loss of patency or re-interventions after that. At latest follow-up of a median 48 months (n = 32), stent patency rate was 97%, with only three patients (9%) experiencing symptoms of PTS.

CONCLUSION

Single session PMT, dedicated venous stents and a risk-mitigation protocol results in high success rate, excellent long-term stent patency and low incidence of PTS without compromising safety. These results support early intervention for iliofemoral DVT.

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.

The background and role of catheter-directed thrombolysis evolving procedures for acute iliofemoral deep venous thrombosis

Minimal invasive treatment such as early endovenous thrombus removal for iliofemoral deep venous thrombosis (DVT) emerged in the end of last century. The principle is catheter-directed thrombolysis (CDT) using either plasminogen activating agents alone, as ultrasound-assisted CDT, or in combination with mechanical devices as pharmaco-mechanical CDT. The interest for this treatment modality is the high rate of post-thrombotic syndrome (PTS) with anticoagulation (AC) alone, especially after iliofemoral DVT. Recently published randomized controlled trials (RCTs) comparing early thrombus removal with AC alone, as well as non-randomized studies, have demonstrated favorable rates, or at least a decrease of moderate and severe PTS, in favor of these procedures. This article will summarize the background and evolution of the procedures in the last three decades and discuss fundamental criteria for inclusion and exclusion, focusing on the procedures regarding thrombus age and location, technical issues, complications and results including different outcome measures for PTS, for which iliac DVT involvement is a massive risk factor to be prevented.

Assessing outcomes after thrombectomy with or without iliac vein stenting for young provoked DVT patients with iliac vein stenosis

BACKGROUND

This study aimed to assess the outcomes of thrombectomy with/without iliac vein stenting for young and transiently provoked DVT patients with iliac vein stenosis.

METHODS

This is a retrospective analysis of a prospectively collected multicenter database. Acute, transiently provoked DVT patients between 18 and 45 years old with iliac vein stenosis were included. All patients underwent thrombectomy. Outcomes including the Villalta score, the VEINES-QOL score, and adverse events were evaluated.

RESULTS

The data of 522 patients were collected of whom 75 were included, 58 underwent thrombectomy alone (nonstenting group) and 17 underwent thrombectomy and stenting (stenting group). Within 6 months, the Villalta score of patients in stenting group is lower than that of patients in nonstenting group (6 mo: 0.73 ± 0.77 vs. 1.41 ± 0.56, p = .0004), and the VEINES-QOL score of stenting group is higher than that of nonstenting group (6 mo: 89.00 ± 2.94 vs. 87.47 ± 3.72, p = .2141). At the following follow-ups, the Villalta score (12 mo: 0.56 ± 0.49 vs. 0.60 ± 0.58, p = .8266) and VEINES-QOL score (12 mo: 88.36 ± 2.29 vs. 88.31 ± 3.36, p = .9604) between the two groups are similar.

CONCLUSION

The stenting group had better efficacy within 6 months after intervention, while there was no significant difference in the symptom, signs, and quality of life between two groups after 6 months within a 2-year follow-up.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Registry (Registration Number: ChiCTR2200056073).

A risk score for iliofemoral patients with deep vein thrombosis

OBJECTIVE

Deep vein thrombosis (DVT) is a common condition with a high risk of post-thrombotic morbidity, especially in patients with a proximal thrombus. Successful iliofemoral clot removal has been shown to decrease the severity of post-thrombotic syndrome. It is assumed that earlier thrombus lysis is associated with a better outcome. Generally, the earlier IFDVT is confirmed, the earlier thrombus lysis could be performed. d-Dimer levels and Wells score are currently used to assess the preduplex probability for DVT; however, some studies indicate that the d-dimer value varies depending on the thrombus extent and localization. Using d-dimer and other risk factors might facilitate development of a model selecting those with an increased risk of IFDVT that might benefit from early referral for additional analysis and adjunctive iliofemoral thrombectomy.

METHODS

All consecutive adult patients from a retrospective cohort of STAR diagnostic center (primary care) in Rotterdam suspected of having DVT between September 2004 and August 2016 were assessed for this retrospective study. The diagnostic workup for DVT including Wells score and d-dimer were performed as well as complete duplex ultrasound examination. Patients with objective evidence of DVT were categorized according to thrombus localization using the Lower Extremity Thrombolysis classification. Logistic regression analysis was done for a model predicting IFDVT. The cut-off value of the model was determined using a receiver operating characteristic curve.

RESULTS

A total of 3381 patients were eligible for study recruitment, of whom 489 (14.5%) had confirmed DVT. We developed a multivariate model (sensitivity of 77% and specificity of 82%; area under the curve, 0.90; 0.86-0.93) based on d-dimer, Wells score, age, and anticoagulation use, which is able to distinguish IFDVT patients from all patients suspected of DVT.

CONCLUSIONS

This multivariate model adequately distinguishes IFDVT among all suspected DVT patients. Practically, this model could give each patient a preduplex risk score, which could be used to prioritize suspected IFDVT patients for an immediate imaging test to confirm or exclude IFDVT. Further validation studies are needed to confirm potential of this prediction model for IFDVT.

Can we predict and prevent the postthrombotic syndrome?

Postthrombotic syndrome (PTS) remains one of the major late complications of deep vein thrombosis (DVT) with a reported prevalence from 10 to 50%. Many factors were found to be related with the development and severity of PTS such as ipsilateral recurrent DVT, advanced age, obesity, ilio-femoral DVT and primary chronic venous disease presence. Some PTS prediction models have been proposed based on risk factor weight. However, it is still difficult to predict which patient with DVT will develop PTS and thus, the clinical application of these models remains limited. Among the identified problems the heterogeneity of the DVT patient population together with the variety of PTS clinical presentations and difficulties concerning PTS severity assessment should be mentioned. Difficulties on the implementation of the specific and objective PTS identification method have also the significant influence on the research focusing on PTS prevention modalities including risk factor modification, compression treatment, anticoagulation and invasive DVT treatment. In this review, the current approach and knowledge on PTS prediction and prevention are presented, including the conservative and invasive DVT treatment possibilities.

Catheter Interventions for Acute Deep Venous Thrombosis: Who, When and How

Deep venous thrombosis (DVT) is common and can be a source of morbidity by way of pulmonary embolism and post-thrombotic syndrome. Recent trials have demonstrated both early and late symptomatic benefit in venous thrombolysis and early recanalisation of the iliocaval system of selected patients. Based on the emerging evidence, national societies have published guidelines that recommend early thrombus removal in iliofemoral DVT in patients with low bleeding risk and good life expectancy. In light of these recommendations, endovenous thrombolysis and/or thrombectomy have become more popular among vein specialists. As more venous technology becomes available, surgeons and interventionalists should take pause and ensure their patient selection and treatment algorithms parallel that of existing and emerging evidence. This article summarises current evidence, technology, and the approach used at a high-volume academic centre in treating iliofemoral DVT.

Less frequent post-thrombotic syndrome after successful catheter-directed thrombolysis for acute iliofemoral deep vein thrombosis

Post-thrombotic syndrome (PTS) occurs in 20-50% of patients with proximal deep vein thrombosis (DVT). In this study, we aimed to identify potential markers of thrombolysis success at the early stage and to clarify the relationship between early thrombolysis success and subsequent PTS development in patients with acute DVT in the iliac vein. Fifty-two consecutive patients with acute iliofemoral DVT who were treated with catheter-directed thrombolysis (CDT) within 21 days of onset were enrolled. An infusion catheter with multiple side holes was placed to cover the thrombosed vessel entirely. Urokinase solution was administered either continuously or with the pulse-spray method at a dose of 480,000-720,000 IU/day over the course of 2-7 days. During CDT, unfractionated heparin (UFH) was infused simultaneously via the access sheath to prevent thrombus formation. Early success was defined as lysis grade ≥ 50% and restoration of forward flow. PTS was diagnosed based on the Villalta scale. Based on the lysis grading method, complete lysis (grade III) was achieved in 8 of 52 (16%) limbs. Lysis grade II (50-99%) was achieved in 35 of 52 (67%) limbs. Lysis grade I (< 50%) was achieved in 9 of 52 (17%) limbs. Therefore, grade II and grade III lytic outcomes (early success) were observed in 43 patients (83%). One-year clinical follow-up was performed for 43 patients (83%). PTS occurred in seven (16%) patients. Early success was more frequently observed in patients without PTS than in those with PTS (92% vs. 43%; P < 0.01). Early success was only significantly associated with PTS in the multivariate analysis. Patients with acute symptomatic iliofemoral DVT who had early success from CDT treatment during the acute phase less frequently progressed to PTS. Patients with early success tended to undergo the pulse-spray method and had a shorter interval from symptom onset to CDT. The use of pulse-spray method and early initiation of CDT since DVT onset were potential markers of thrombolysis success.

Acute Venous Iliofemoral Thrombosis: Early Surgical Thrombectomy Is Effective and Durable

BACKGROUND

The first-line recommendation for the treatment of acute iliofemoral deep vein thrombosis (IFDVT) is catheter-directed thrombolysis or pharmacomechanical thrombolysis. Recent analysis of surgical thrombectomy has shown comparable results. However, this procedure is not commonly given as much importance as interventional techniques. We analyzed the patient outcome of surgical thrombectomy using modern endovascular techniques in both the short and long term.

METHODS

All consecutive patients who underwent surgical thrombectomy at our institution between April 2008 and April 2017 were included. Only patients with iliofemoral thrombosis, and only those with the first onset of symptoms <10 days, were analyzed. All patients received preoperative duplex ultrasound and contrast-enhanced computed tomography scans for thrombus extension and detection of pulmonary embolism. All operations were performed by vascular surgeons with open and endovascular skills in a C-arm-equipped operating room. During follow-up (FU), all patients received clinical examination for symptoms of postthrombotic syndrome (PTS), as well as duplex ultrasound.

RESULTS

Within a 9-year period, 21 patients underwent surgical thrombectomy for IFDVT (17 females/4 males). Primary technical success was 100%; 10 (47.6%) patients received additional primary stenting. 30-day mortality was 0%, 3 patients (14.3%) needed reoperation for early rethrombosis, while secondary 30-day patency was 100%. During FU (median, 6 years; range, 1-104 months), 1 patient received additional stenting for stenosis of the common iliac vein. Nineteen patients (90.5%) presented patent iliofemoral veins without signs of rethrombosis. Two patients (9.5%) died during FU of cancer without signs for recurrent IFDVT. All patients with patent veins were free of symptoms for PTS.

CONCLUSIONS

Surgical thrombectomy for acute IFDVT is a successful, safe, and durable procedure and provides alternative treatment options for acute IFDVT in selected cases.