Endovascular stent treatment for symptomatic benign iliofemoral venous occlusive disease: long-term results 1987-2009

Indications, technical aspects, and outcomes of stent placement in chronic iliofemoral venous obstruction

BACKGROUND

Iliofemoral venous stent placement (IVS) has evolved to a well-established endovascular treatment modality for chronic iliofemoral venous obstruction (CIVO). Dedicated venous stents gained approval from the US Food and Drug Administration in 2019 and solidified IVS as a defined intervention with clear indications, contraindications, risks, benefits, and procedural management principles. This review focuses on the indications, technical aspects and outcomes of stenting for CIVO. Other aspects pertaining to IVS are covered in other articles that are a part of this series.

METHODS

This study conducted a literature search limited to English articles. Three search strategies were used, and references were managed in Covidence software. Four investigators screened and evaluated articles independently, excluding meta-analyses, clinical trial protocols, and nonrelevant studies. Eligible studies, focused on clinical outcomes and stent patencies, underwent thorough review.

RESULTS

The literature search yielded 1704 studies, with 147 meeting eligibility criteria after screening and evaluation. Exclusions were based on duplicates, irrelevant content, and noniliac vein stent placement.

CONCLUSIONS

Successful IVS for CIVO relies on meticulous patient selection, consistent use of intravascular ultrasound examination during procedures and attention to the technical details of IVS.

Iliocaval and iliofemoral venous stenting for obstruction secondary to tumor compression

BACKGROUND

Cancer patients with pelviabdominal masses can suffer from lower extremity symptoms due to venous compression. The effectiveness of venous stenting has been established in extrinsic venous compression in benign conditions like May-Thurner syndrome. In this retrospective study we evaluate the efficacy and safety of caval, iliocaval and iliofemoral venous stenting for cases of extrinsic venous compression caused by malignant masses in cancer patients.

METHODS

IRB-approved retrospective review of patients who underwent iliofemoral venography with venoplasty and stenting between January 2018 and February 2022 was performed. Patients with extrinsic venous compression caused by malignant masses were included. Data on patient demographics, pre-procedure symptoms, procedural technique, stent characteristics, outcomes and follow-up were collected. Descriptive statistics were used to assess technical success, clinical success, primary stent patency and adverse events of the procedure.

RESULTS

Thirty-seven patients (19 males, 18 females) who underwent 45 procedures were included. Deep venous thrombosis (DVT) was present in 21 (57%) patients. Twenty-nine patients (78%, 95% CI 62-90%) reported clinical improvement of the presenting symptoms. The median overall survival after the procedure was 4.7 months (95% CI 3.58-5.99). Eight (22%) patients were alive at last follow up with median follow up of 10.33 months (Range 2-25 months). Twenty-six patients had patent stents on their last follow up imaging (70%, 95% CI 61%-91%). Two patients had a small access site hematoma which resolved spontaneously. Two patients developed moderate, and 1 patient developed severe adverse events related to post procedure therapeutic anticoagulation.

CONCLUSION

Venous stenting is a safe procedure and should be considered as part of the palliative care for patients with debilitating lower extremity symptoms related to iliocaval and iliofemoral venous compression.

Iliocaval and Iliofemoral Venous Stenting for Obstruction Secondary to Tumor Compression: Single Center Experience

Background

Cancer patients with pelviabdominal masses can suffer from lower extremity symptoms due to venous compression. The effectiveness of venous stenting has been established in extrinsic venous compression in benign conditions like May-Thurner syndrome. In this retrospective study we evaluate the efficacy and safety of caval, iliocaval and iliofemoral venous stenting for cases of extrinsic venous compression caused by malignant masses in cancer patients.

Methods

IRB-approved retrospective review of patients who underwent iliofemoral venography with venoplasty and stenting between January 2018 and February 2022 was performed. Patients with extrinsic venous compression caused by malignant masses were included. Data on patient demographics, pre-procedure symptoms, procedural technique, stent characteristics, outcomes and follow-up were collected. Descriptive statistics were used to assess technical success, clinical success, primary stent patency and adverse events of the procedure.

Results

Thirty-seven patients (19 males, 18 females) who underwent 45 procedures were included. Deep venous thrombosis (DVT) was present in 21 (57%) patients. Twenty-nine patients (78%, 95% CI 62-90%) reported clinical improvement of the presenting symptoms. The median overall survival after the procedure was 4.7 months (95% CI 3.58-5.99). Eight (22%) patients were alive at last follow up with median follow up of 10.33 months (Range 2-25 months). Twenty-six patients had patent stents on their last follow up imaging (70%, 95% CI 61%-91%). Two patients had a small access site hematoma which resolved spontaneously. Two patients developed moderate, and 1 patient developed severe adverse events related to post procedure therapeutic anticoagulation.

Conclusion

Venous stenting is a safe procedure and should be considered as part of the palliative care for patients with debilitating lower extremity symptoms related to iliocaval and iliofemoral venous compression.

Comparison between a dedicated venous stent and standard composite Wallstent-Z stent approach to iliofemoral venous stenting: Intermediate-term outcomes

OBJECTIVE

Dedicated venous stents have not been used in the management of symptomatic chronic iliofemoral venous obstruction (CIVO) until recently. The Bard Venovo stent (Becton, Dickinson, and Co, Franklin Lakes, NJ) is one such stent noted to have an increased chronic outward force and radial resistive force compared with the Wallstent (Boston Scientific, Marlborough, MA). In the present study, we evaluated the outcomes following the use of the Bard Venovo stent vs a matched cohort of limbs that had undergone stenting with the Wallstent-Zenith (Z) stent (Cook Medical Inc, Bloomington, IN) composite configuration.

METHODS

A review of contemporaneously entered electronic medical record data for 167 patients (167 limbs) with initial iliofemoral stents placed from 2019 to 2020 for quality of life (QOL)-impairing CIVO that had failed conservative therapy was performed. The visual analog scale for pain score (score, 0-10), grade of swelling (score, 0-4), venous clinical severity score (score, 0-27), and the 20-item chronic venous insufficiency quality of life questionnaire instrument for QOL were evaluated before and after intervention to assess the effects of stenting. A Kaplan-Meier analysis was used to examine primary, primary-assisted and secondary stent patency, and analysis of variance with repeated measures was used to compare clinical outcomes.

RESULTS

A total of 167 limbs had undergone Bard Venovo stenting (56 men and 111 women). Their median age was 61 years. The laterality was right and left in 70 and 97 limbs, respectively. Post-thrombotic syndrome was seen in 84 limbs and nonthrombotic iliac vein lesions/May-Thurner syndrome in 83 limbs. At 6 months, the venous clinical severity score had improved from 7 to 4 in the limbs with a unilateral Venovo (UV) stent and from 5 to 4 in the composite Wallstent-Z stent group (P = .9). The grade of swelling had improved from 3 to 1 in the UV group and from 3 to 1 in the composite group (P = .6), and the visual analog scale for pain score had improved from 7 to 2 in the UV group and from 5 to 0 in the composite group (P = .007). At 12 months, ulcers had healed in 53% (8 of 15) of the UV group and 56% (5 of 9) of the composite group (P = .7). The global 20-item chronic venous insufficiency quality of life questionnaire scores had improved from 58 to 28 in the UV group and from 59 to 40 in the composite group (P = .6). The cumulative primary, primary-assisted, and secondary patency at 18 months was 81%, 97%, and 98% in the UV group and 87%, 98%, and 100% in the composite group, respectively (P > .4). No difference in the reintervention rates was noted between the two groups (P = .5).

CONCLUSIONS

For patients who had undergone stenting for QOL-impairing CIVO, the results with the Bard Venovo venous stent were comparable to those with the composite Wallstent-Z stent configuration for clinical outcomes, QOL improvement, and stent patency. Further study is, however, required to confirm this improvement in the long term.

Iliofemoral venous configurations from three-dimensional computed tomography venogram and their relevance to stent design

OBJECTIVE

Iliofemoral venous stenting has become the standard of care for patients presenting with quality-of-life impairing symptoms of chronic iliofemoral venous obstruction not responding to conservative measures. This has led to an increased use of venous stenting over the last several years. However, iliofemoral venous anatomy in patients requiring such intervention remains poorly elucidated. This study attempts to fill that gap.

METHODS

Twenty-two consecutive patients with intravascular ultrasound examination-confirmed chronic iliofemoral venous obstruction underwent three-dimensional reconstruction of their computed tomography venogram images. Relevant angles, tortuosity (tort index-ratio between centerline length, and straight line length), lengths, and diameters were computed and analyzed. We used t tests for comparisons between the right and left sides. A P value of .05 or less was considered significant.

RESULTS

Of the angles calculated, the median of the angles between the horizontal and common iliac vein (CIV) was 66° on the right and 60° on the left (P < .01). The median inferior vena cava-CIV angle was 172° on the right and 165° on the left (P < .0001). The CIV-EIV angle was 159° on the right and 151° on the L (P = .01). Overall, the median tortuosity was 1.07 on the right and 1.12 on the left (P = .007). The median centerline length of the CIV was 42mm on the right and 60mm on the left (P < .0001). The median external iliac vein length was 73 mm on the right and 88 mm on the left (P < .0001). The overall median iliac vein length was 220 mm on the right and 237 mm on the left (P < .01). The median diameters of the inferior vena cava at the iliocaval confluence, 20, 40, and 60 mm cranial to the confluence, were 23, 20, 22, and 23 mm, respectively.

CONCLUSIONS

Overall, the left side has steeper angles, greater tortuosity, and longer lengths than the right side. These disparities should be considered during femoroiliocaval stent construction.

Role of lower extremity fasciectomy-fasciotomy in patients with persistent leg pain after stenting for chronic iliofemoral venous obstruction

Although clinical improvement after stenting for symptomatic iliofemoral venous obstruction has been demonstrated in multiple large studies, a small proportion of patients will experience persistent quality of life–impairing symptoms. Swelling in such a setting represents the concomitant presence of lymphedema and will respond to treatment directed at the lymphedema. In contrast, persistent pain likely arises from venous hypertension in the lower leg, leading to the development of chronic compartment syndrome. Evaluation of intracompartmental pressures in such patients can help confirm the diagnosis, and fasciectomy combined with fasciotomy will treat the issue. In the present series, we evaluated six patients (six limbs) who had undergone fasciectomy combined with fasciotomy and their outcomes.

Utility of a Mechanical Thrombectomy Device in Treating Calcified Instent Restenosis Post Iliofemoral Venous Stenting

Instent restenosis (ISR) following iliofemoral venous stenting is quite common with up to three-quarters of patients developing some degree of ISR. However, only around 16% develop recurrent symptoms impairing their quality-of-life meriting reintervention. The first line of treatment for such ISR involves the use of angioplasty balloons to recreate an adequate flow channel. At times such angioplasty alone is inadequate particularly in the presence of calcified ISR. It is in this setting that the authors decided to explore the utility of a mechanical thrombectomy device to debulk the ISR and thereby help create an adequate flow channel. The successful utilization of such a device in a patient presenting with recurrent, disabling, quality of life impairing symptoms due to ISR represents the focus of this report.

Three-Year Results from the Venovo Venous Stent Study for the Treatment of Iliac and Femoral Vein Obstruction

Purpose

To assess safety and patency of the Venovo venous stent for the treatment of iliofemoral vein obstruction.

Materials and Methods

Twenty-two international centers enrolled 170 patients in the VERNACULAR study (93 post-thrombotic syndrome; 77 non-thrombotic iliac vein lesions). Primary outcome measures were major adverse events at 30 days and 12-month primary patency (freedom from target vessel revascularization, thrombotic occlusion, or stenosis > 50%). Secondary outcomes included the Venous Clinical Severity Score Pain Assessment and Chronic Venous Quality-of-Life Questionnaire assessments (hypothesis tested). Secondary observations included primary patency, target vessel and lesion revascularization (TVR/TLR), and assessment of stent integrity through 36 months.

Results

Freedom from major adverse events through 30 days was 93.5%, statistically higher than a pre-specified performance goal of 89% (p = 0.032) while primary patency at 12 months was 88.6%, also statistically higher than a performance goal of 74% (p < 0.0001). Mean quality-of-life measures were statistically improved compared to baseline values at 12 months (p < 0.0001). Primary patency at 36 months was 84% (Kaplan–Meier analysis) while freedom from TVR/TLR was 88.1%. There was no stent embolization/migration, and no core laboratory assessed stent fractures reported through 36 months. Six deaths were reported; none adjudicated as device or procedure related.

Conclusion

The Venovo venous stent was successfully deployed in obstructive iliofemoral vein lesions and met the pre-specified primary outcome measures through 12 months. At 3 years, primary patency was 84%, reintervention rates were low, standardized quality-of-life and pain measures improved from baseline, and there was no stent migration or fractures.

Level of Evidence

Level 2—prospective, multicenter, controlled clinical study without a concurrent control or randomization. Pre-specified endpoints were hypothesis-tested to performance goals derived from peer-reviewed clinical literature.

Registration clinicaltrials.gov

Unique Identifier NCT02655887.

Utility of the 50% stenosis criterion for patients undergoing stenting for chronic iliofemoral venous obstruction

OBJECTIVE

The criterion for venous stenting in symptomatic chronic iliofemoral venous obstruction has been the arbitrary use of stenosis of ≥50%. In the present study, we evaluated the intravascular ultrasound (IVUS)-determined degree of stenosis in patients who had undergone stenting for quality of life (QOL)-impairing symptoms and assessed the utility of the 50% stenosis cutoff.

METHODS

A retrospective review of contemporaneously entered electronic medical record data from 480 continuous patients (480 limbs) with initial iliofemoral stents placed (2014 to 2017) for symptomatic chronic iliofemoral venous obstruction impairing their QOL was performed. The IVUS-determined normal minimal luminal areas for the common femoral vein (125 mm), external iliac vein (150 mm), and common iliac vein (200 mm) were used to group limbs as having <50% (low-grade stenosis [LGS]) or ≥50% (high-grade stenosis [HGS]) stenosis. The variables compared included the visual analog scale (VAS) for pain score, venous clinical severity score (VCSS; range, 0-27), ulcer healing, supine foot venous pressures, QOL (20-item chronic venous disease QOL questionnaire), and stent patency. A composite chronic venous insufficiency score (CCVIS) incorporating the VAS score, VCSS, and CIVIQ-20 score for predicting improvement after stenting was evaluated.

RESULTS

Of the 480 limbs, 283 and 197 were in the LGS and HGS groups, respectively. A preponderance of women, left laterality, and post-thrombotic syndrome were noted in both groups. At baseline, although no difference was found in the VAS for pain score between groups, the LGS group had a higher VCSS than did the HGS group (P = .05). The baseline median supine foot venous pressure was 15 and 14 mm Hg in the LGS and HGS groups, respectively (P = .17). At 24 months after stenting, the mean VCSS had improved from 6.3 to 4.4 (P < .0001) and from 5.7 to 3.7 (P < .0001) in the LGS and HGS groups, respectively, without significant differences between the two groups (P = .07). A greater prevalence of ulcers was found in the LGS group (18% vs 11%; P = .04), with no differences in healing (P = .41) or recurrence rates (P = .36). The QOL scores had improved in both groups (LGS, from 58 to 37 [P < .0001]; HGS, from 61 to 35 [P < .0001]), without differences between the two groups (P > .3). No significant differences in stent patency or reinterventions rates were found. A baseline CCVIS of ≥84.5, ≥86.9, or ≥105.3 was needed for a 30-, 40-, and 50-point improvement in most limbs after stenting.

CONCLUSIONS

The degree of IVUS-determined iliofemoral venous stenosis did not appear to affect the initial clinical presentation, CEAP (clinical, etiologic, anatomic, pathophysiologic) clinical class, supine foot venous pressure, clinical improvement, QOL improvement, stent patency, or reintervention rates after stenting. Patients presenting with QOL-impairing symptoms in whom conservative treatment has failed merit consideration of correction of their obstruction even if the degree of stenosis is <50%. The use of a CCVIS might be helpful but requires further study.

Role of laser ablation in recalcitrant instent restenosis post iliofemoral venous stenting

Instent restenosis (ISR) represents the most common reason for recurrent symptoms requiring reintervention in patients who have undergone venous stenting for chronic iliofemoral venous obstruction. Treatment of ISR requires stent angioplasty typically using angioplasty balloons equal to or larger than the rated diameter of the stent. At times this does not yield the required result, and in these patients, utilization of a laser catheter supported by an angled sheath is helpful to ablate the ISR or make it more amenable to repeat balloon angioplasty. The authors report their experience with this technique for 18 patients with recurrent symptoms impacting quality of life as a result of recalcitrant ISR in this retrospective review of contemporaneously entered electronic medical record data. 12 (67%) limbs underwent laser ablation only, while 6 (33%) limbs underwent additional angioplasty post laser ablation. Post intervention for ISR, at 12 months, the venous clinical severity score improved from 5 to 3.5 (P = .0005) and the VAS pain score went from 7 to 5 (P = .0005). At 10 months, primary patency was 87% and primary assisted patency was 100%. There were no stent occlusions. Laser ablation of recalcitrant instent restenosis in patients presenting with recurrent chronic iliac venous obstruction post iliofemoral venous stenting is a safe and effective option. Corroboration from larger studies is warranted.

Long-term outcomes following use of a composite Wallstent-Z stent approach to iliofemoral venous stenting

OBJECTIVE

An endovascular approach has essentially replaced open surgery in the management of symptomatic chronic obstructive iliofemoral venous disease. In the last several years, such a minimally invasive approach has shifted from use of Wallstents alone to a combination of Wallstent-Z stent (composite stenting) to better deal with the iliocaval confluence. This study evaluates the clinical and stent related outcomes following use of composite stenting.

METHODS

A retrospective review of contemporaneously entered EMR data on 535 patients (545 limbs) with initial iliofemoral stents placed over a 4-year period from 2014 to 2017 for symptomatic chronic iliofemoral venous obstruction was performed. Patients who underwent stenting after intervention for acute deep venous thrombosis were excluded. The impact of stenting on clinical outcomes before and after the intervention were evaluated through use of the visual analog scale pain score (0-10), grade of swelling (0-4), and Venous Clinical Severity Score (0-27). Quality of life was appraised using the Chronic Venous Disease quality of life Questionnaire 20 instrument. Kaplan-Meier analysis was used to assess primary, primary assisted and secondary stent patencies, and paired and unpaired t-tests were used to examine clinical outcomes.

RESULTS

Of the 545 limbs that underwent stenting, 183 were in men and 362 were in women. The median age was 60 years. Laterality was right in 205 limbs and left in 340 limbs. Post-thrombotic syndrome was seen in 441 limbs and nonthrombotic iliac vein lesions/May-Thurner syndrome in 104 limbs. At 24 months, visual analog scale pain score went from 5 to 2 (P < .0001), grade of swelling went from 3 to 1 (P < .0001), and Venous Clinical Severity Score went from 6 to 4 (P < .0001). Ulcers were present in 67 limbs and had healed in 49 limbs (73%) over a median follow-up of 26 months. Global Chronic Venous Disease quality of life Questionnaire scores improved from 60 to 36 (P < .0001) after stenting. Cumulative primary, primary-assisted, and secondary patencies at 60 months were 70%, 99% and 91%, respectively. Thirty limbs (5.5%) required contralateral stenting. There was only one instance (0.2%) of contralateral iliofemoral deep venous thrombosis. One hundred eleven limbs (20%) underwent reintervention, including for in-stent restenosis in 44 limbs, stent compression in 2 limbs, in-stent restenosis and stent compression in 48 limbs, and stent occlusion in 17 limbs.

CONCLUSIONS

In patients undergoing iliofemoral venous stenting for obstructive disease, clinical improvement, quality of life improvement, and stent patencies after use of a composite stent configuration are comparable with those seen after exclusive use of Wallstents. However, the use of a composite stent configuration not only decreases the need for contralateral stenting to relieve chronic obstruction, but also decreases the incidence of contralateral iliofemoral deep venous thrombosis.

Three-dimensional computed tomography venogram enables accurate diagnosis and treatment of patients presenting with symptomatic chronic iliofemoral venous obstruction

OBJECTIVE

The last several years has witnessed an increase in the diagnosis and treatment of chronic iliofemoral venous obstructive lesions. Although intravascular ultrasound (IVUS) examination has become the gold standard in the management of chronic iliofemoral venous obstruction (CIVO), it is an invasive technique. To ascertain the usefulness of noninvasive imaging technology in diagnosing and treating CIVO in symptomatic patients, we compared three-dimensional (3D) reconstructions from computed tomography venogram (CTV) with IVUS examination.

METHODS

Twenty-two continuous patients who underwent IVUS interrogation during intervention for CIVO formed the study cohort. Patients who had stenting performed in the setting of chronic total occlusion of the iliofemoral segment or acute iliofemoral deep venous thrombosis were excluded. All patients underwent CTV as part of their standard preoperative work up. Minimal (smallest) luminal areas of the common iliac vein (CIV), external iliac vein (EIV), common femoral vein (CFV) and the inflow channel (segment caudal to the CFV) were obtained from 3D CTV and IVUS. Centerline length measurements were obtained from 3D CTV to estimate the length of the venous stents necessary; the inflow channel luminal area was used to predict the required stent diameter. Pearson correlation was used to evaluate the association between the luminal areas obtained from the two techniques. Agreement was ascertained by use of Bland-Altman limits of agreement. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 3D CTV in predicting luminal areas was also determined. Predicted stent diameters and lengths were compared against actual stent diameters and lengths used.

RESULTS

Pearson correlation statistic for luminal areas between 3D CTV and IVUS for the CIV was 0.89 (P < .01), for EIV was 0.77 (P < .01), and for CFV was 0.69 (P < .01). The correlation statistic for the inflow channel luminal area was 0.90 (P < .01). The sensitivity of 3D CTV in diagnosing CIVO in the CIV, EIV, and CFV were 100%, 100% and 80%, respectively. The specificity was 67%, 57%, and 86%, respectively, in the CIV, EIV, and CFV segments. The positive predictive value of 3D CTV in determining CIVO in the CIV, EIV, and CFV segments was 89%, 83%, and 92%, and the negative predictive value was 100%, 100%, and 67%, respectively. The overall accuracy was 91%, 86%, and 82% in the CIV, EIV, and CFV segments. Thus, 3D CTV is able to predict stent length within 9.5 mm of the actual stent length used. With respect to stent diameter, 3D CTV was able to predict within 2 mm of the actual stent diameter used 91% (20/22) and within 4 mm of the actual stent diameter used 100% (22/22) of the time.

CONCLUSIONS

From a diagnostic standpoint 3D CTV does well with an overall accuracy ranging from 82% in the CFV to 91% in the CIV in predicting CIVO. It is also able to accurately predict venous stent diameter and lengths required, rendering it a good tool in the diagnosis and treatment of symptomatic CIVO.

Characteristics and outcomes of stent occlusion after iliocaval stenting

OBJECTIVE

With increasing use of iliocaval stenting, complications have become more noticeable. Stent occlusion is one such outcome that has not been studied in detail. Characteristics of stent occlusion in addition to outcomes after recanalization are presented.

METHODS

An analysis of 3468 initial iliocaval stents placed during an 18-year period from 1997 to 2015 was performed. A total of 102 stent occlusions were identified, amounting to a 3% stent occlusion rate. Characteristics evaluated included onset after stent placement, techniques used for restoring patency, and their outcome. Kaplan-Meier analysis was used to assess stent patency. Regression analysis was used to evaluate risk factors for stent occlusion.

RESULTS

Stent occlusions occurred at a median of 5.8 months after placement. The occluded stent could be reopened after a wide range of intervals, the longest being 14 years. The majority (69%) of occlusions were chronic (>30 days) and the remainder (31%) were acute; 77% of the occlusions occurred in post-thrombotic limbs. The most common technique used to recanalize the acutely occluded stent was pharmacomechanical thrombectomy, whereas wire recanalization with balloon angioplasty was the technique most used for chronic occlusions. Of the 102 occluded stents, patency was achieved in 75 of 88 (84%) attempts. After successful recanalization, the median primary patency was 7 ± 1.9 months, median primary assisted patency was 7.5 ± 3.5 months, and median secondary patency was 25 ± 8.3 months. Clinically, there was improvement in the visual analog scale pain scores from a median of 3.5 to 1 (P < .01), in the median grade of swelling from 2 to 1 (P < .01), and in the mean Venous Clinical Severity Score from 6.4 to 3.8 (P < .01) after recanalization. A 40% ulcer healing rate was noted after recanalization during a median follow-up period of 17 months. There were no significant adverse events or mortality. Regression analysis revealed stent placement for native vein occlusion as the only statistically significant predictor of stent occlusion.

CONCLUSIONS

Stent occlusion after iliocaval stenting is a rare occurrence. Recanalization of occluded stents can be performed with minimal morbidity even months to years after occlusion with good outcomes. Long-term patency of occluded stents that were recanalized is poor compared with patency of the initially placed stent.

Central Venous Pathologies: Treatments and Economic Impact

Chronic venous insufficiency (CVI) is responsible for significant costs to society in the form of medical and surgical treatment and, importantly, unmeasurable lost work productivity due to pain and disability. Symptomatic chronic central vein obstruction, a cause of CVI, is potentially treatable using open surgical and endovascular techniques to restore vessel patency. Although upper extremity central vein obstruction often requires an open surgical procedure for durable relief, endovascular stents have proven remarkably useful for iliofemoral disease. Containment of healthcare resources requires accurate diagnosis, durable treatment modalities, and appropriate patient selection so that therapy is targeted to those individuals most likely to benefit. In this regard, identification of appropriate lesions should be based on intravascular ultrasound and 3-dimensional imaging studies. Treatment with dedicated venous stents offers the potential for long-term symptomatic improvement and increased work productivity when used in a well-defined, anatomically appropriate population with significant, symptomatic CVI.

Investigation of adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents in the iliac vein: insights into developing a better iliac vein stent

We analyzed the adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents for the treatment of iliac venous thromboembolism and investigated their relationships with the anatomical features of the iliac vein, to gain insights into the development of a better iliac vein stent. Reports of adverse events following the use of stents in the iliac vein were retrieved from the Manufacturer and User Facility Device Experience (MAUDE) database that contain suspected device-associated complications reported to the Food and Drug Administration. Data from 2006 to 2016 were investigated. The literature analysis was also conducted using PubMed, Cochrane Library, EMBASE, and Web of Science focusing on English articles published up to 4 October 2016. The analysis of 88 adverse events from the MAUDE database and 182 articles from the literature revealed that a higher number of adverse events had been reported following the use of arterial stents in the iliac vein compared to CE-marked iliac vein stents. While stent migration and shortening were reported only for the arterial stents, stent fracture and compression occurred regardless of the stent type, even though a vein does not pulsate. A study of the anatomical features of the iliac vein implies that bending, compression, and kink loads are applied to the iliac vein stents in vivo. For designing, developing, and pre-clinical testing of stents intended for use in the iliac vein, the above mechanical load environments induced by the anatomical features should be considered.

Endovascular stent placement for chronic post-thrombotic symptomatic ilio-femoral venous obstructive lesions: a single-center study of safety, efficacy and quality-of-life improvement

BACKGROUND

Post-thrombotic syndrome (PTS) is a frequent complication of deep vein thrombosis (DVT) despite adequate treatment. Venous angioplasty and stent placement has been progressively used to restore and maintain venous patency in PTS patients. This study reports our single-center experience with the use of endovascular treatment for chronic post-thrombotic symptomatic ilio-femoral venous obstructive lesions.

METHODS

A prospective mono-centric observational cohort study of PTS patients with chronic symptomatic ilio-femoral venous obstructive lesions referred for endovascular treatment was conducted from March 2012 to April 2016. Procedure consisted in recanalization, pre-dilation and self-expandable stenting of stenotic or occluded iliac and/or femoral veins. Severity of PTS, quality-of-life and treatment outcomes were assessed using Villalta scale and Chronic Venous Insufficiency Questionnaire (CIVIQ-20) at baseline and 3 months after the procedure. Imaging follow-up was based on duplex ultrasound (US) and computed tomography (CT).

RESULTS

Twenty-one patients (11 females, 10 males; median age, 41 years; range, 32-60) were included. Recanalization and stenting was successfully accomplished in all prime procedures, 4 patients benefitted from an additional procedure. Immediate technical success rate was 96% considering 25 procedures, performed without any complications. Median follow-up was 18 months (range, 6-30 months) with a 90.5% stent patency rate. Villalta score significantly decreased from baseline compared with 3 months after the procedure [14 (range, 11-22) and 5 (range, 1-10), respectively, P<0.0001], showing a significant decrease in the severity of PTS. CIVIQ-20 score significantly decreased from baseline compared with 3 months after stenting [48.5 (range, 39-73) and 26.5 (range, 21-45), respectively, P<0.0001] thus showing a significant improvement of quality-of-life. Post-procedural CIVIQ-20 score was significantly associated with Villalta score (95% CI, 1.53-2.95; P<0.0001).

CONCLUSIONS

Our results confirm the high clinical success rate and safety of endovascular PTS treatment and highlight the significant impact of stenting on the quality of life of patients with chronic symptomatic ilio-femoral venous obstructive lesions.

Thrombolysis and iliofemoral vein stent placement in cancer patients with lower extremity swelling attributed to lymphedema

PURPOSE

To assess the effects of iliofemoral vein stent placement on symptomatic lower extremity swelling (LES), presumed to be lymphedema, in patients with cancer.

MATERIALS AND METHODS

During the period 2005-2013, 62 patients (38 female; age, 60.4 y ± 15.4) with histology-proven metastatic disease and LES resistant to standard therapies were evaluated and found to have venous outflow obstruction. Stents were placed in the iliofemoral veins or inferior vena cava, or both, and evaluated by color Doppler ultrasound or contrast-enhanced computed tomography during the follow-up period. Patient symptoms were assessed using the Venous Disability Score (VDS) and the Galway Limb Swelling score, a patient-directed, 5-question symptom scoring system.

RESULTS

Stents were successfully placed in all patients. During the follow-up period, in-stent thrombosis occurred in 13 patients, and additional stents were placed in 3 patients to treat luminal narrowing. The mean VDS improved significantly (P < .05): from 3.0 ± 0 on the day of the procedure to 2.95 ± 0.22 on day 3, 2.0 ± 0.33 on day 7, and 1.87 ± 0.34 on day 30. The mean Galway Limb Swelling score also improved significantly (P < 0.001): from 3.6 ± 0.74 on the day of the procedure to 1.96 ± 0.91 on day 3, 1.06 ± 0.78 on day 7, and 0.6 ± 0.66 on day 30. During the follow-up period, 60 patients died as a result of their underlying malignancy (mean, 230 d; range, 5-1,080 d).

CONCLUSIONS

Iliofemoral or iliocaval venous stent placement may have a valuable role in patients with metastatic disease and symptomatic LES associated with venous obstruction.

What would surgeons like from materials scientists?

Surgery involves the repair, resection, replacement, or improvement of body parts and functions and in numerous ways, surgery should be considered human engineering. There are many areas in which surgical materials could be improved, but surgeons are generally unaware of materials available for use, while materials scientists do not know what surgeons require. This article will review some of the areas where surgeons and materials scientists have interacted in the past and will discuss some of the most pressing problems which remain to be solved. These include better implant materials for hernia repair, breast reconstruction, the treatment of diabetes, vascular stenting and reconstruction, and electrical pacing devices. The combination of tissue engineering and nanomaterials has great potential for application to nearly every aspect of surgery. Tissue engineering will allow cells or artificial organs to be grown for specific uses while nanotechnology will help to ensure maximal biocompatibility. Biosensors will be combined with improved electrodes and pacing devices to control impaired neurological functions.