An Overview of Specific Considerations in Chronic Venous Disease and Iliofemoral Venous Stenting.

Unlike arterial disease, chronic venous disease (CVD) is rarely life-threatening or limb-threatening. However, it can impose substantial morbidity on patients by influencing their lifestyle and quality of life (QoL). The aim of this nonsystematic narrative review is to provide an overview of the most recent information on the management of CVD and specifically, iliofemoral venous stenting in the context of personalized considerations for specific patient populations. The philosophy of treating CVD and phases of endovenous iliac stenting are also described in this review. Additionally, the use of intravascular ultrasound is described as the preferred operative diagnostic procedural tool for iliofemoral venous stent placement.

Iliac vein stent failure in community practice and results of corrective reinterventions.

OBJECTIVE: The goal of endovenous stenting is to relieve venous obstruction and reduce peripheral venous hypertension by using large caliber venous stents in the presence of adequate venous inflow and outflow for the stented conduit. The aim of this report is to describe the technical reasons and outcomes for reinterventions in a subset of patients who had a history of iliac vein stenting and were now referred to us at a specialty venous clinic for further care. METHODS: From January 2016 to December 2021, records of all patients who were referred to us with a history of iliac vein stenting performed at an outside facility and who had a reoperation performed at our center were retrospectively analyzed. RESULTS: A total of 149 limbs underwent a deep venous reintervention after a failure of a trial of conservative therapy. The mean age of the sample was 57 ± 16 years. The ratio of non-thrombotic iliac vein lesions to post-thrombotic lesions was 1:2.5. The majority of the patients (84%) were CEAP class C4 or higher. The most common reason for reintervention was stent occlusion (74%), followed by iatrogenic stenosis (53%) and in-stent restenosis/shelving (38%). There was a trend for improvement in all clinical parameters (venous clinical severity score, visual analog scale for pain, and edema grade) after the reintervention. Poor inflow was present in 70% of limbs with stent occlusion. The median diameters of stented common femoral vein, external iliac vein, and common iliac vein prior to reintervention were 12, 12, and 13 mm, respectively. The median diameters of stented common femoral vein, external iliac vein, and common iliac vein after reintervention were 14, 15, and 16 mm, respectively. Eighty-eight percent of limbs required at least one further reintervention after initial reoperation. CONCLUSIONS: Venous reoperations are generally infrequent and required in a small number of patients. Poor inflow appeared to be a common cause of stent occlusion. Iatrogenic stenosis is another common reason for venous reoperation and is difficult to fully rectify through current endovascular techniques and tools. Use of intravascular ultrasound planimetry routinely in every deep venous intervention and thorough knowledge of the principles of venous stenting outlined in this report may help forestall the need for reoperative deep venous surgery in some cases.

Plethysmographic features of calf pump failure in chronic venous obstruction and reflux.

BACKGROUND: Calf pump failure (CPF) is a common concept in chronic venous disease. Dorsal vein pressures were originally used to define the pathophysiology. More recently, an abnormal ejection fraction (EF) and residual volume fraction (RVF) with air plethysmography (APG) have been substituted for its diagnosis. The relationship between reflux and calf pump function has been studied extensively. Reflux is thought to be the main cause of CPF, although other mechanisms may play a secondary role. Data mining in our dataset revealed that CPF is frequently found in nonrefluxive limbs-an unexpected finding. We analyzed the APG features of CPF in nonrefluxive limbs of a large cohort of patients investigated for chronic venous disease in our clinic. Data from refluxive limbs (control) seen over the same period was included for comparison. Venous obstructive pathology was variably present in both subsets. Iliac vein stent outcome in CPF limbs from both subsets is included. The role of obstruction in CPF is currently unknown. METHODS: Records of 13,234 limbs in 8813 patients evaluated for suspected chronic venous disease over a 22-year period were analyzed. Prestent and poststent data in 406 CPF limbs (129 nonrefluxive; 277 refluxive) that underwent iliac vein stenting to correct associated stenosis are included. This is a single-center retrospective analysis of prospectively collected data. Duplex and APG data were available for included limbs. A RVF of more than 50% was defined as CPF. A reflux time of greater than 1 second elicited with automated cuffs in the erect position was defined as reflux. RESULTS: There were 7780 (59%) limbs with reflux and 5454 (41%) that were nonrefluxive. Supine venous pressure, an index of venous obstruction, was elevated in both subsets. The incidence of CPF was 25% in refluxive limbs and 16% in nonrefluxive limbs totaling 2790 limbs. Venous volume and venous filling index were significantly elevated (P = .0001) in refluxive limbs compared to nonrefluxive limbs. The EF was diminished (<50%) in all CPF limbs except in a small fraction (n = 427 [3%]). Stent correction of iliac vein stenosis corrected CPF, normalizing the RVF in both subsets. CONCLUSIONS: CPF frequently occurs in nonrefluxive limbs with incidence only slightly less than in refluxive limbs. An RVF of more than 50% seems to be a practical definition of a CPF; an EF of less than 50% is associated with a RVF of greater than 50% in 97% of analyzed limbs. Prospective identification of CPF in limbs with chronic venous disease may allow more detailed investigation of its cause (preload, afterload, neuromuscular pathology or joint immobility, etc) and direct more targeted treatment than currently practiced.

Assessment of flow mechanics in the lower extremity venous system.

BACKGROUND: The Reynolds number (Re) is a dimensionless parameter that describes fluid flow mechanics. Veins are compliant and collapsible vascular conduits that can accommodate large volume changes in response to small pressure changes. However, only sparse information is available about flow parameters such as the Re in the venous system. METHODS: Bilateral duplex ultrasound examination of 15 healthy volunteers (30 limbs) was performed before and after exercise (four flights of stairs) of the veins of the lower extremity (left and right sides) and inferior vena cava. These volunteers had been confirmed to not have any signs or symptoms of lower extremity venous disease via focused history and physical examination findings. RESULTS: Most of the volunteers were women (73%). Their mean age was 37 ± 12.8 years. The Re was highest in the inferior vena cava among all the veins examined (470 ± 144 before exercise and 589 ± 205 after exercise; P = .04). The association between the change in Re before and after exercise and the specific vein examined was also significant for the right and left external iliac veins, right and left common femoral veins, right and left profunda femoris veins, right and left femoral veins, and right common iliac vein. Resistance and velocity maps for the lower extremity venous system were also created. The velocity increased and the resistance decreased as one moved up the venous tree toward the right atrium. CONCLUSIONS: The Re increased for most of the lower extremity veins after exercise in our healthy volunteers. However, the critical value for turbulent flow was not reached despite the exercise.

Clinical tolerance of untreated reflux after iliac vein stent placement.

BACKGROUND: We have recently demonstrated in a large patient cohort that the prevalence and severity of reflux will improve in most limbs after stenting and that most limbs will not develop new-onset reflux. In the present report, we have focused on the long-term clinical outcomes associated with untreated reflux in the same patient cohort who had undergone iliofemoral venous stenting without correction of residual reflux. METHODS: The clinical outcomes data from 1379 limbs treated with only iliac vein stenting without correction of superficial or deep reflux from 1997 to 2018 were analyzed (23-year follow-up period). Of the 1379 limbs, 632 (46%) had had preexisting reflux before stenting and 747 (54%) had did not. The reflux data (reflux segmental score, air plethysmography, ambulatory venous pressure) for these patients have been previously reported in detail. The subsets were compared perioperatively with each other using the following variables: grade of swelling, visual analog scale for pain score, venous clinical severity score, venous stasis dermatitis, ulceration, and quality of life measures. RESULTS: Both groups demonstrated improvements in the venous clinical severity score, grade of swelling, visual analog scale score, and quality of life. No differences were found in ulcer healing (5% vs 3% for limbs with and without prestent reflux, respectively) and resolution of dermatitis (6% vs 5% for limbs with and without prestent reflux, respectively) between the two groups. Of the 632 limbs with preexisting reflux, 218 (34%) had had axial reflux and 414 had had nonaxial reflux (66%). The clinical outcomes were similar between the two groups. Using a multisegment reflux score, the limbs with prestent reflux (n = 632) were divided into two groups. A segmental score of ≥3 indicated severe reflux and a score of <3 indicated moderate reflux. Of these 632 limbs, 161 (25%) had severe reflux and 471 (75%) had moderate reflux. The two groups demonstrated similar outcomes for most clinical parameters. The post-thrombotic limbs and nonthrombotic limbs also showed similar outcomes. CONCLUSIONS: The long-term follow-up of patients after iliac vein stenting showed that uncorrected reflux is well tolerated by most patients across most clinical measures.

Utility of a percutaneous mechanical thrombectomy device in retrieval of an iatrogenic intravascular foreign body.

Intravascular foreign bodies can result from endovascular procedures and from other medical implants and devices. A wide variety of techniques and devices have been described for the retrieval of such intravascular foreign bodies in reported studies. In the present report, we have described the case of a patient with a symptomatic left innominate vein deep vein thrombosis who also had a retained catheter fragment from a fractured tunneled infusion catheter in the left innominate vein. Using the Inari ClotTriever system (Inari Medical, Irvine, CA), we were able to, not only restore venous outflow by treating the acute deep vein thrombosis, but also retrieve the fragments of the fractured catheter.

Percutaneous laser recanalization in chronically occluded iliofemoral venous stents.

Occlusion is a challenging complication of endovenous stenting. The treatment of chronic iliofemoral stent occlusion involves wire recanalization followed by balloon angioplasty. However, this approach will not always be successful. To treat such cases, we have successfully used a laser recanalization technique in 34 limbs (31 patients). This technique involved the use of a laser to first create a channel through the chronically occluded stent, followed by balloon angioplasty to improve the caliber of this recanalized tract. The mean age of the patients was 52 ± 13.6 years (range, 24-73 years). No adverse events related to the use of the laser occurred. Following laser recanalization, the venous clinical severity score had improved from 8.2 ± 4 to 5.1 ± 3.3 (P < .0001). The visual analog scale score for pain had improved from 7.8 ± 2.5 to 4.9 ± 3 (P = .0009). The grade of swelling had improved from 2.7 ± 1.3 to 1.6 ± 1.4 (P = .0001). At 12 months after intervention, the primary stent patency was 60% (standard error of the mean, 9.3%), and the secondary stent patency was 80%. Excimer laser recanalization of chronically occluded venous stents appears to be a rarely required but useful modality with reasonable clinical outcomes. Further reinterventions might be required to maintain long-term stent patency.

Options in the treatment of superficial and deep venous disease in patients with Klippel-Trenaunay syndrome.

OBJECTIVE: Klippel-Trenaunay syndrome (KTS) is a congenital mixed mesenchymal malformation syndrome that includes varicose veins, capillary and venous malformations, lymphatic abnormalities, and hypertrophy of various connective tissue elements. The purpose of the present study was to describe the clinical characteristics and outcomes in a subset of patients with KTS in whom venous interventions, including iliofemoral venous stenting, were performed after failure of conservative therapy. METHODS: A single-center retrospective data review of 34 patients with KTS who had undergone interventions for venous disease between January 2000 and December 2020 was performed. RESULTS: Their mean age was 38.4 ± 17.5 years (range, 12-80 years). No gender predilection was found. Of the 34 patients, 61% had had all three features of the classic triad for KTS. Varicose veins were present in all 34 patients (100%), and 30% had had a history of bleeding varicosities. Most patients (79%) had CEAP (Clinical, Etiology, Anatomy, and Pathophysiology) class ≥C4. Of the 34 patients, 30% had a history of deep vein thrombosis and/or pulmonary embolism. Factor VIII elevation was the most common thrombophilia condition (12%). The venous filling index was elevated at baseline (5.9 ± 5.1 mL/s) and did not normalize despite intervention (3.5 ± 2.3 mL/s; P = .04). The superficial venous interventions (n = 35) included endovenous laser therapy; stripping of the great saphenous vein, small saphenous vein, anterior thigh vein, or marginal vein; ultrasound-guided sclerotherapy; and stab avulsion of varicose veins. One coil embolization of a perforator vein was performed. Deep interventions (n = 19) included endovenous stenting (n = 15), popliteal vein release (n = 3), and valvuloplasty (n = 1). The venous clinical severity score had improved from 9.4 ± 4.5 to 6.2 ± 5.6 (P = .04). The visual analog scale for pain score had improved from 5.5 ± 2.7 to 2.5 ± 3.3 (P = .008). Healing of ulceration was noted in 75% of the patients. Significant improvements in the total pain (P = .04) and total psychological (P = .03) domains were noted in the 20-item chronic venous disease quality of life questionnaire. CONCLUSIONS: Superficial and deep venous interventions are safe and effective in patients with KTS when conservative therapy has failed. Iliofemoral venous stenting is a newer option that should be considered in the treatment of chronic deep venous obstructive disease in patients with KTS in the appropriate clinical context. An aggressive perioperative deep vein thrombosis prophylaxis protocol should be in place to reduce thromboembolic complications in these patients.

Comparison of intravascular ultrasound and magnetic resonance venography in the diagnosis of chronic iliac venous disease.

BACKGROUND: The diagnosis of chronic iliofemoral venous obstruction (CIVO) can be made with several different modalities. Intravascular ultrasound (IVUS) examination is the gold standard in the diagnosis of CIVO. However, being invasive, it should not be the initial examination to screen patients with CIVO. The aim of this report is to compare the performance of magnetic resonance venography (MRV) with IVUS examination in the diagnosis of CIVO. METHODS: From January 2016 to December 2020, the records of all patients who underwent preoperative MRV and then IVUS in the evaluation of CIVO were analyzed retrospectively. RESULTS: There were 505 patients who were evaluated by any modality for CIVO. Of these patients, 15% (78) were evaluated by MRV. Patients who had failed a trial of conservative therapy for at least 3 to 6 months and who had disabling and lifestyle-limiting symptoms of CIVO were selected to undergo further evaluation with MRV at the treating physician's discretion. For inclusion in analysis, technically satisfactory IVUS examination and MRV data were mandatory. Data was available for 60 common iliac vein (CIV) segments and 61 external iliac vein (EIV) segments for comparative analysis after appropriate exclusions. The mean age of the patients was 56 ± 15 years. The male to female ratio was 1:2. The distribution of patients across different CEAP classes was as follows: CEAP 3, 28%; CEAP 4, 62%; CEAP 5, 2%; and CEAP 6, 8%. Bland-Altman plots of the mean difference in area between IVUS examination and MRI were 74.1% for CIV and 56.9% for EIV. The sensitivity of MRV was 93% and 100%, and the specificity was 0% and 50% for CIV and EIV, respectively. The positive predictive value was 93% and 86%; the negative predictive value was 0 and 50% for CIV and EIV, respectively. Improvement was noted in clinical parameters (Venous Clinical Severity Score, visual analog pain scale, and grade of swelling) after IVUS examination and stenting after MRV. For the Venous Clinical Severity Score, the score improved from 6.0 ± 2.7 (before the procedure) to 4 ± 2.7 (after the procedure) (P = .0001). CONCLUSIONS: There is dimensional disparity between MRV and IVUS examination in the diagnosis of symptomatic CIVO. MRV has a high sensitivity but low specificity when compared with IVUS examination and overestimates the severity of the stenosis in both the EIV and CIV. MRV is not a reliable diagnostic tool for iliac vein stenosis and should not be used for the definitive disposition of patients with CIVO.