Clinical impact of assessing thrombus age using magnetic resonance venography prior to catheter-directed thrombolysis.

OBJECTIVES: Magnetic resonance venography (MRV) is underutilized in the evaluation of thrombus properties prior to endovascular treatment but may improve procedural outcomes. We therefore investigated the clinical impact of using a dedicated MRV scoring system to assess thrombus characteristics prior to endovascular intervention for iliofemoral deep vein thrombosis (DVT). METHODS: This is a post hoc analysis of data from the CAVA trial ( Clinicaltrials.gov :NCT00970619). MRV studies of patients receiving ultrasound-accelerated catheter-directed thrombolysis (CDT) for iliofemoral DVT were reviewed. Thrombus age-related imaging characteristics were scored and translated into an overall score (acute, subacute, or old). MRV scores were compared to patient-reported complaints. MRV-scored groups were compared for CDT duration and success rate. RESULTS: Fifty-six patients (29 men; age 50.8 ± 16.4 years) were included. Using MRV, 27 thrombi were classified acute, 17 subacute, and 12 old. Based on patient-reported complaints, 11 (91.7%) of these old thrombi would have been categorized acute or subacute, and one (3.7%) of the acute thrombi as old. Average duration of CDT to > 90% restored patency differed significantly between groups (p < 0.0001): average duration was 23 h for acute thromboses (range: 19-25), 43 h for subacute (range: 41-62), and 85 h for old thromboses (range: 74-96). CDT was almost eleven times more successful in thromboses characterized as acute and subacute compared to old thromboses (OR: 10.7; 95% CI 2.1-55.5). CONCLUSION: A dedicated MRV scoring system can safely discriminate between acute, subacute, and old thromboses. MRV-based selection is predictive of procedural duration and success rate and can help avoid unnecessary complications. KEY POINTS: • Thrombus age, characterized by MRV as acute, subacute, and old, can predict CDT duration and probability of success. • Accurate pre-interventional MRV-based thrombus aging has the potential to facilitate identification of eligible patients and may thus prevent CDT-related complications.

Development of a Management Algorithm for Acute and Chronic Radiation Urethritis and Cystitis.

OBJECTIVE: The purpose of this review was to summarize the current literature on the assessment and treatment of radiation urethritis and cystitis (RUC) for the development of an evidenced-based management algorithm. MATERIAL AND METHODS: The PubMed/MEDLINE database was searched by a multidisciplinary group of experts in January 2021. RESULTS: In total, 48 publications were identified. Three different types of RUC can be observed in clinical practice: inflammation-predominant, bleeding-predominant, and the combination of inflammation- and bleeding-RUC. There is no consensus on the optimal treatment of RUC. Inflammation-predominant RUC should be treated symptomatically based on the existence of bothersome storage or voiding lower urinary tract symptom as well as on pain. When bleeding-predominant RUC has occurred, hydration and hyperbaric oxygen therapy (HOT) should be used first and, if HOT is not available, oral drugs instead (sodium pentosane polysulfate, aminocaproic acid, immunokine WF 10, conjugated estrogene, or pentoxifylline + vitamin E). If local bleeding persists, focal therapy of bleeding vessels with a laser or electrocoagulation is indicated. In case of generalized bleeding, intravesical installation should be initiated (formalin, aluminium salts, and hyaluronic acid/chondroitin). Vessel embolization is a less invasive treatment with potentially less complications and good clinical outcomes. Open- or robot-assisted surgery is indicated in patients with permanent, life-threatening bleeding, or fistulae. CONCLUSIONS: Treatment of RUC, if not self-limiting, should be done according to the type of RUC and in a stepwise approach. Conservative/medical treatment (oral and topic agents) should primarily be used before invasive (transurethral) treatments.

Gadobutrol versus gadofosveset-trisodium in MR venography of the lower extremities.

OBJECTIVES: MR venography (MRV) protocols have used bloodpool contrast agents and long scan sequences to identify patients suitable for treatment and preoperatively. However, variable availability of bloodpool contrast agents, high costs and a need to shorten acquisition times for routine MR protocols hamper everyday practice. MATERIALS: 20 patients (11 men; mean age 54 ± 11.8 years; body mass index 23.6 ± 2.5) were enrolled in this prospective study. An intra-individual comparison of image quality, interpretation and findings for two different contrast agents (regular gadolinium contrast agent gadobutrol vs. bloodpool contrast agent gadofosveset-trisodium) and two different scan protocols (long acquisition time protocol using a high-resolution fast field echo (FFE) sequence vs. short acquisition time protocol using an ultra-fast gradient echo (GE) sequence) were performed. RESULTS: Image quality (average of 4.94 vs. 4.92 on a five-point scale), interpretation and contrast-to-noise ratio (44 vs. 45) were equal for both contrast agents. Image findings showed no statistical significant differences between the MR protocols or contrast agents (overall p = 0.328). CONCLUSIONS: For high-resolution MRV, it is possible to replace gadofosveset-trisodium with gadobutrol. Furthermore, an ultra-fast GE sequence for MRV might considerably shorten acquisition time, without loss of image quality or diagnostic yield. KEY POINTS: • High-quality MRV can be performed with a regular gadolinium-based contrast agent. • Ultra-fast GRE vs. HR-FFE MRV: equally suitable for evaluation of venous obstruction. • Regular gadolinium-based contrast agent can supersede a bloodpool contrast agent for MRV. • Equal confidence for gadobutrol vs gadofosveset-trisodium in MRV. • MRV accessible for routine daily practice.

Clinical Evaluation of Wound Healing in Split-Skin Graft Donor Sites Using Microscopic Quantification of Reepithelialization.

OBJECTIVE: Impaired or delayed wound healing is a common health problem. However, it remains challenging to predict whether wounds in patients will heal without complication or will have a prolonged healing time. In this study, the authors developed an objective screening tool to assess wound healing using microscopic quantification of reepithelialization in a split-thickness skin graft wound model and used this tool to identify risk factors for defective wound healing. DESIGN: Thirty patients (16 male and 14 female) were included in this prospective study. Anterior thigh skin biopsies from the donor site region of partial-thickness skin grafts were dressed with moisture-retentive dressings, and biopsies were examined on days 0, 2, 5, and 10 postoperatively by microscopy. Images were then transferred to a computer for image analysis and epithelial measurements (epithelial thickness and total reepithelialized surface). The effects of gender, age, body mass index, and smoking behavior on these wound healing parameters were determined. RESULTS: The authors found comparable results for the computer and traditional measure methods. However, the time required to perform the measurements using the semiautomated computer method was less than half the time of the traditional method. Image capturing, enhancing, and analysis with the new method required approximately 2 minutes 30 seconds, whereas the traditional methods took up to 7 minutes per image. The total size of the reepithelialized surface (P = .047) and percentage of the biopsy resurfaced with epithelia (P = .011) at day 10 were both significantly higher in male patients compared with female patients. In patients younger than 55 years, reepithelialized areas were significantly thicker than in patients older than 55 years (P = .008), whereas the size of the reepithelialized surface showed no differences. No significant differences in reepithelialization parameters were found concerning body mass index and smoking behavior. CONCLUSIONS: Both male gender and older age impair reepithelialization rate and epithelial thickness in partial-thickness skin graft donor site wounds. In contrast, body mass index and smoking behavior have not been shown to be influencing factors on reepithelialization. Thus, microscopic quantification of reepithelialization might be a suitable method for predicting complications associated with wound healing.

Fast and accurate liver volumetry prior to hepatectomy.

BACKGROUND: Volumetric assessment of the liver is essential in the prevention of postresectional liver failure after partial hepatectomy. Currently used methods are accurate but time-consuming. This study aimed to test a new automated method for preoperative volumetric liver assessment. METHODS: Patients who underwent a contrast enhanced portovenous phase CT-scan prior to hepatectomy in 2012 were included. Total liver volume (TLV) and future remnant liver volume (FRLV) were measured using TeraRecon Aquarius iNtuition(®) (autosegmentation) and OsiriX(®) (manual segmentation) software by two observers for each software package. Remnant liver volume percentage (RLV%) was calculated. Time needed to determine TLV and FRLV was measured. Inter-observer variability was assessed using Bland-Altman plots. RESULTS: Twenty-seven patients were included. There were no significant differences in measured volumes between OsiriX(®) and iNtuition(®). Moreover, there were significant correlations between the OsiriX(®) observers, the iNtuition(®) observers and between OsiriX(®) and iNtuition(®) post-processing systems (all R(2) > 0.97). The median time needed for complete liver volumetric analysis was 18.4 ± 4.9 min with OsiriX(®) and 5.8 ± 1.7 min using iNtuition(®) (p < 0.001). CONCLUSION: Both OsiriX(®) and iNtuition(®) liver volumetry are accurate and easily applicable. However, volumetric assessment of the liver with iNtuition(®) auto-segmentation is three times faster compared to manual OsiriX(®) volumetry.

Imaging of Deep Venous Pathology.

Imaging plays an important role in the identification and assessment of clinically suspected venous pathology. The purpose of this article is to review the spectrum of image-based diagnostic tools used in the investigation of suspected deep vein disease, both obstructive (deep vein thrombosis and post-thrombotic vein changes) as well as insufficiency (e.g., compression syndromes and pelvic venous insufficiency). Additionally, specific imaging modalities are used for the treatment and during clinical follow-up. The use of duplex ultrasound, magnetic resonance venography, computed tomography venography and intravascular ultrasound as well as conventional venography will be discussed in this pictorial review.

Cystic Adventitial Disease of the (ilio) Femoral Artery with a Connection to the Hip Joint: Case Report and a Review of the Literature.

Objective: Cystic adventitial disease (CAD) is an uncommon non-atherosclerotic peripheral vessel disease, most often seen in the popliteal artery. Only a small number of cases involving the (ilio) femoral artery have been reported. The case of a 48 year old female with CAD of the left femoral artery with a connection of the disease to the hip joint on pre-operative imaging confirmed during surgery is described. A literature review of CAD of the (ilio) femoral artery with patient demographic data, symptoms, management, presence of a joint connection, and long term outcomes was performed. Methods: Multiple databases (Medline, CINAHL, EMBASE) were searched and each article was cross referenced to collect the literature on CAD of the (ilio) femoral artery. Case studies or series of CAD of the (ilio) femoral artery in English between 1995 and 2021 were included. Results: Sixteen case reports with 17 patients were included; 71% were male. CAD was unilateral in all case reports, with 53% on the right side. Patients presented with vascular symptoms including claudication (88%), a palpable pulsating mass (18%), acute limb ischaemia (6%) or limb swelling (8%). Computed tomography angiography (CTA) (76%) and duplex ultrasonography (47%) were the most commonly used imaging modalities. The common femoral artery was the most affected site (88%). Reported treatments were cyst resection and autologous vein reconstruction (six, one recurrence), cyst resection and patch repair (five, one recurrence), cyst resection with synthetic graft reconstruction (three, no recurrence), cyst resection (two, one recurrence), and cyst incision and decompression (one, one recurrence). In 18% of the cases, a connection between the CAD and hip joint was seen. Conclusion: Cyst resection and ligation with interposition of an autologous vein graft, synthetic graft or patch repair (in only locally affected arteries) seems to be the preferred treatment, with a low reported recurrence rate. CTA and magnetic resonance imaging are the imaging modalities of choice when suspecting CAD to determine an appropriate pre-operative plan and identify joint connections.

Association of Successful Ultrasound-Accelerated Catheter-Directed Thrombolysis with Postthrombotic Syndrome: A Post Hoc Analysis of the CAVA Trial.

BACKGROUND: The CAVA trial did not show the anticipated risk reduction for postthrombotic syndrome (PTS) after thrombus removal via additional ultrasound-accelerated catheter-directed thrombolysis (UACDT) in patients with acute iliofemoral deep vein thrombosis (IFDVT). Difficulties in achieving an effective degree of recanalization through thrombolysis may have influenced outcomes. We therefore assessed whether successful UACDT (restored patency ≥ 90%) did reduce the development of PTS. METHODS: This CAVA trial post hoc analysis compared the proportion of PTS at 1-year follow-up between patients with successful UACDT and patients that received standard treatment only. In addition, clinical impact as well as determinants of successful thrombolysis were explored. RESULTS: UACDT was initiated in 77 (50.7%) patients and considered successful in 41 (53.2%, interrater agreement κ = 0.7, 95% confidence interval 0.47-0.83). PTS developed in 15/41 (36.6%) patients in the successful UACDT group versus 33/75 (44.0%) controls (p = 0.44). In this comparison, successful UACDT was associated with lower Venous Clinical Severity Score (3.50 ± 2.57 vs. 4.82 ± 2.74, p = 0.02) and higher EuroQOL-5D (EQ-5D) scores (40.2 ± 36.4 vs. 23.4 ± 34.4, p = 0.01). Compared with unsuccessful UACDT, successful UACDT was associated with a shorter symptom duration at inclusion (p = 0.05), and higher rates of performed adjunctive procedures (p < 0.001) and stent placement (p < 0.001). CONCLUSION: Successful UACDT was not associated with a reduced proportion of PTS 1 year after acute IFDVT compared with patients receiving standard treatment alone. There was, however, a significant reduction in symptom severity and improvement of generic quality of life according to the EQ-5D. Better patient selection and optimization of treatment protocols are needed to assess the full potential of UACDT for the prevention of PTS. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov number, NCT00970619.

Ultrasound-accelerated catheter-directed thrombolysis versus anticoagulation for the prevention of post-thrombotic syndrome (CAVA): a single-blind, multicentre, randomised trial.

BACKGROUND: Early thrombus removal might prevent post-thrombotic syndrome by preserving venous function and restoring flow. Previous trials comparing additional catheter-directed thrombolysis to standard treatment showed conflicting outcomes. We aimed to assess the benefit of additional ultrasound-accelerated catheter-directed thrombolysis for the prevention of post-thrombotic syndrome compared with standard therapy in patients with iliofemoral deep-vein thrombosis. METHODS: We did a multicentre, randomised, single-blind, allocation-concealed, parallel group, superiority trial in 15 hospitals in the Netherlands. Patients aged 18-85 years with a first-time acute iliofemoral deep-vein thrombosis and symptoms for no more than 14 days were randomly assigned (1:1) to either standard treatment with additional ultrasound-accelerated catheter-directed thrombolysis or standard treatment alone. Randomisation was done with a web-based automatic programme and a random varying block size (2-12), stratified by age and centre. Standard treatment included anticoagulant therapy, compression therapy (knee-high elastic compression stockings; 30-40 mmHg), and early ambulation. Additional ultrasound-accelerated catheter-directed thrombolysis was done with urokinase with a starting bolus of 250 000 international units (IU) in 10 mL NaCl followed by a continuous dose of 100 000 IU/h for a maximum of 96 h through the Ekos Endowave-system. Adjunctive percutaneous transluminal angioplasty, thrombosuction, or stenting was performed at the discretion of the physician who performed the intervention. The primary outcome was the proportion of patients with post-thrombotic syndrome at 12 months diagnosed according to the original Villalta criteria-a Villalta-score of at least 5 on two consecutive occasions at least 3 months apart or the occurrence of venous ulceration-and was assessed in a modified intention-to-treat population of all randomly assigned patients who passed screening and started treatment. The safety analysis was assessed in the same modified intention-to-treat population. This study is complete and is registered at ClinicalTrials.gov, NCT00970619. FINDINGS: Between May 28, 2010, and Sept 18, 2017, 184 patients were randomly assigned to either additional ultrasound-accelerated catheter-directed thrombolysis (n=91) or standard treatment alone (n=93). Exclusion because of screening failure or early withdrawal of informed consent resulted in 77 patients in the intervention group and 75 in the standard treatment group starting allocated treatment. Median follow-up was 12·0 months (IQR 6·0-12·0). 12-month post-thrombotic syndrome occurred in 22 (29%) patients allocated to additional treatment versus 26 (35%) patients receiving standard treatment alone (odds ratio 0·75 [95% CI 0·38 to 1·50]; p=0·42). Major bleeding occurred in four (5%) patients in the intervention group, with associated neuropraxia or the peroneal nerve in one patient, and no events in the standard treatment group. No serious adverse events occurred. None of the four deaths (one [1%] in the intervention group vs three [4%] in the standard treatment group) were treatment related. INTERPRETATION: This study showed that additional ultrasound-accelerated catheter-directed thrombolysis does not change the risk of post-thrombotic syndrome 1 year after acute iliofemoral deep-vein thrombosis compared with standard therapy alone. Although this trial is inconclusive, the outcome suggests the possibility of a moderate beneficial effect with additional ultrasound-accelerated catheter-directed thrombolysis. Further research is therefore warranted to better understand this outcome in the context of previous trials, preferably by combining the available evidence in an individual patient data meta-analysis. FUNDING: The Netherlands Organisation for Health Research and Development (ZonMw), Maastricht University Medical Centre, BTG-Interventional Medicine.

Abdominal and pubic collateral veins as indicators of deep venous obstruction.

OBJECTIVE: Chronic deep venous obstruction can cause a significant loss of quality of life, although it can be treated successfully by stenting. A clear referral pattern for additional imaging is warranted in patients with lower limb complaints. The aim of this study was to determine the value of clinically visible abdominal wall collateral veins in the diagnosis of a potentially treatable deep venous obstruction. METHODS: A total of 295 patients referred for evaluation at a tertiary venous clinic with a collateral vein on the abdominal wall or pubic bone, visible on physical examination, were retrospectively analyzed and compared with a randomly selected control group of 365 patients without such a collateral vein. Duplex ultrasound, magnetic resonance venography, computed tomography venography, and conventional venography were used to determine the presence or absence of deep venous obstruction. RESULTS: Mean age of the group with a positive collateral was 43.5 ± 13.7 (6-76) years compared with 44.7 ± 14.2 (16-89) years in the control group. In the collateral group, 66.1% were female compared with 63.3% in the control group. Sensitivity of the abdominal wall collateral vein for any obstruction at the level of the groin or more proximal was 53% (95% confidence interval [CI], 48-57); specificity, 86% (95% CI, 79-91); positive predictive value, 93% (95% CI, 90-96); and negative predictive value, 32% (95% CI, 28-37). Sensitivity was 68% (95% CI, 62-73) for higher degrees of post-thrombotic obstruction and 27% (95% CI, 19-36) in iliac vein compression. CONCLUSIONS: A collateral vein on the abdominal wall or across the pubic bone in patients with complaints of the lower limb has an excellent positive predictive value for deep venous obstructive disease at the level of the groin or higher. Such collateral veins should therefore not be removed, and symptomatic patients could be offered further diagnostics and treatment.

The value of hemodynamic measurements by air plethysmography in diagnosing venous obstruction of the lower limb.

OBJECTIVE: Air plethysmography (APG) is a functional, noninvasive test that can assess volumetric changes in the lower limb and might therefore be used as a diagnostic tool in chronic deep venous disease. However, use of APG in chronic deep venous obstructive disease remains debatable. This study assessed the clinical value of APG in identifying chronic deep venous obstruction. METHODS: All patients referred to our tertiary, outpatient clinic between January 2011 and August 2013 with chronic venous complaints and suspected outflow obstruction underwent an outflow fraction (OF), ejection fraction (EF), and residual volume fraction (RVF) test using APG. Duplex ultrasound and magnetic resonance venography were used to establish whether and where obstruction was present. Diagnostic values of these tests were assessed for obstructions at different levels of the deep venous system. RESULTS: A total of 312 limbs in 248 patients were tested. Mean age was 45.5 ± 14.0 years, and 62.5% were female. In post-thrombotic disease, specificity and positive predictive value for OF were as high as 98.4% and 95.0%, respectively; however, sensitivity was 34.8% and negative predictive value was 29.6%, with no clinically relevant positive or negative likelihood ratios. No clinically relevant differences were observed in stratifying for level of obstruction. EF and RVF were as inconclusive. Neither could these parameters be used in diagnosing nonthrombotic iliac vein compression. CONCLUSIONS: We found a poor correlation between OF, EF, or RVF, determined by APG, and the presence of chronic deep venous obstruction. Therefore, use of its relative parameters is unwarranted in daily clinical practice.

The Role of Spectral Tissue Sensing During Lumbar Transforaminal Epidural Injection.

Spectral tissue sensing (STS) exploits the scattering and absorption of light by tissue. The main objective of the present study was to determine whether STS can discriminate between correct and incorrect placement of the needle tip during lumbar transforaminal epidural injection. This was a single-blind prospective observational study in 30 patients with lumbar radicular pain scheduled for lumbar transforaminal epidural injection. Spectral tissue sensing data from the needle tip were acquired along the needle trajectory at 4 predefined measurement points and compared with ultrasound, fluoroscopy, and digital subtraction angiography images. Spectral tissue sensing data contained the full spectra. The lipid and hemoglobin content at the different measurement points was also calculated, and partial least-squares discriminant analysis was used to estimate the sensitivity and specificity of STS. Spectral tissue sensing identified correct needle placement with a sensitivity of 57% and a specificity of 82%, and intraforaminal versus extraforaminal locations were identified with a sensitivity of 80% and a specificity of 71%.

Efficacy of radiation safety glasses in interventional radiology.

PURPOSE: This study was designed to evaluate the reduction of the eye lens dose when wearing protective eyewear in interventional radiology and to identify conditions that optimize the efficacy of radiation safety glasses. METHODS: The dose reduction provided by different models of radiation safety glasses was measured on an anthropomorphic phantom head. The influence of the orientation of the phantom head on the dose reduction was studied in detail. The dose reduction in interventional radiological practice was assessed by dose measurements on radiologists wearing either leaded or no glasses or using a ceiling suspended screen. RESULTS: The different models of radiation safety glasses provided a dose reduction in the range of a factor of 7.9-10.0 for frontal exposure of the phantom. The dose reduction was strongly reduced when the head is turned to the side relative to the irradiated volume. The eye closest to the tube was better protected due to side shielding and eyewear curvature. In clinical practice, the mean dose reduction was a factor of 2.1. Using a ceiling suspended lead glass shield resulted in a mean dose reduction of a factor of 5.7. CONCLUSIONS: The efficacy of radiation protection glasses depends on the orientation of the operator's head relative to the irradiated volume. Glasses can offer good protection to the eye under clinically relevant conditions. However, the performance in clinical practice in our study was lower than expected. This is likely related to nonoptimized room geometry and training of the staff as well as measurement methodology.

Ultrasound-accelerated catheter-directed thrombolysis in acute iliofemoral deep venous thrombosis.

BACKGROUND: Iliofemoral deep venous thrombosis (DVT) is associated with a high incidence of the post-thrombotic syndrome. The current CHEST guidelines suggest that catheter-directed thrombolysis can be used for patients with acute iliofemoral DVT and severe leg complaints. Current literature shows that catheter-directed thrombolysis increases patency of the affected tract and may reduce post-thrombotic complications, but treatment time and bleeding complications are high. Ultrasound-accelerated catheter-directed thrombolysis (UACDT) uses ultrasound waves to enhance clot lysis, which should lower treatment time and bleeding complications with the same or higher patency rates. We report our clinical experience with UACDT on patency and complications in patients with acute iliofemoral DVT. METHODS: Patients treated with UACDT for acute iliofemoral DVT were included in our analyses. Diagnosis of iliofemoral DVT was confirmed using duplex sonography and magnetic resonance venography. In addition to thrombolysis, stents were placed or an arteriovenous fistula was created to ensure patency of the treated vein, if indicated. The main outcome is patency after 1 year. Secondary outcome measures are treatment time, bleeding complications, and pulmonary embolism. Patency was assessed using duplex sonography. RESULTS: In total, 37 patients (average age at intervention, 42 years; range, 5-76 years) were included. The DVT location was unilateral in 33 patients (20 left side, 13 right side), and four were bilateral. The average treatment time was 43 ±17 hours. The success rate of thrombolysis was 95% (n = 35); re-thrombosis occurred in 11 (30%) patients. Major bleeding occurred in one patient (3%), and three minor bleedings occurred at the insertion side of the catheter (8%). One pulmonary embolism was encountered (3%). One patient had fever with positive blood cultures for Staphylococcus aureus. Additional procedures were required in 54% (n = 20) of patients. Primary patency was 70% at 1 year; secondary patency was 87% after 1-year follow up. CONCLUSIONS: UACDT of acute iliofemoral DVT is feasible and safe. Supplementary percutaneous transluminal angioplasty and stenting play an important role in preventing re-thrombosis.

[Catheter-directed thrombolysis in iliofemoral deep-vein thrombosis]. / Kathetergeleide trombolyse bij iliofemorale diepveneuze trombose.

Despite optimal treatment of acute deep-vein thrombosis (DVT) there is a great chance of recurrent DVT and development of post-thrombotic syndrome (PTS) in the long term. The degree of spontaneous recanalization differs per patient and per thrombus location. 90% of all femoropopliteal occlusions will fully recanalize within 1 year; however, in the case of an iliofemoral thrombosis, recanalization occurs only in a minority of cases. Post-thrombotic complications occur more often following iliofemoral thrombosis, and the chance of recurrent thrombosis is greater than following thrombosis in a more distal location. An anatomical variation or abnormality also more often underlies an iliofemoral thrombosis. It is important to identify patients with a greater chance of developing PTS promptly and to treat them in order to prevent post-thrombotic damage. There are still insufficient trial data available to implement catheter-directed thrombolysis as standard therapy for iliofemoral thrombosis