Iliac Vein Stenting for Chronic Proximal Venous Outflow Obstruction in a Predominantly Asian-American Cohort

BACKGROUND

We investigated the outcome of vein stenting placement for chronic proximal venous outflow obstruction (PVOO) in a predominantly Asian-American cohort to improve patient selection, enhance technical approach, and better define quality measurements of this emerging vascular intervention.

METHODS

A total of 462 consecutive patients, 73% Asian American (n = 336), who underwent iliac vein stenting for chronic PVOO from October 2013 to July 2016 were reviewed. Postoperative outcomes at five follow-up visits were assessed. Wilcoxon-Mann-Whitney and Kruskal-Wallis tests were run for demographic and operative variables. Ordered logistic regressions were run for the outcome at each time point, and Chi-squared tests as well as Fisher's exact tests were used for categorical variables.

RESULTS

Follow-up was maintained in 90% of patients, with a mean follow-up time of 695 days. Asian-American patients were more likely to present with varicose veins (77.4% vs. 54.8%, P < 0.001), and non-Asian patients were more likely to present with active ulceration (26.2% vs. 5.1%, P < 0.001). Asian-American patients were more likely to have bilateral stents placed (61.6% vs. 50%, P = 0.026) and were less likely to have reinterventions (11.3% vs. 27.8%, P < 0.001), a history of deep vein thrombosis (8.3% vs. 29.4%, P < 0.001), or intraoperative findings of chronic postphlebitic changes (17.6% vs. 33.3%, P < 0.001). Kruskal-Wallis tests were significant for improvement in patients of all the Clinical, Etiology, Anatomy, Pathophysiology classes at 30 days (P = 0.041), 90 days (P = 0.045), 6 months (P = 0.041), and 1 year (P < 0.01). The Asian-American population had improved but comparatively lower follow-up scores at the 30-day mark (48% significantly improved or better vs. 63%, P = 0.008) but higher follow-up scores at the >1 year mark (80% significantly improved or better vs. 59%, P < 0.001).

CONCLUSIONS

Asian-American patients undergoing vein stent placement for chronic PVOO had comparatively worse outcomes than non-Asian patients at 30 days and better outcomes after one year. These patient groups had different outcomes postoperatively and outcomes which evolve differently over time.

Spontaneous hemorrhage from varicose veins: A single-center experience

OBJECTIVE

Whereas the commonly described manifestations of venous insufficiency include telangiectasia, varicose veins (VVs), edema, skin changes, and ulcers, we have noted some patients who present with external hemorrhage from lower extremity VVs. Because there are few recent data examining this entity, we herein describe our experience.

METHODS

During 29 months, we had 32 patients present with hemorrhage from lower extremity VVs. There were 15 men and 17 women with a mean age of 60.2 years (range, 38-89 years; standard deviation [SD], ±14.9 years). Interestingly, 16 of these patients presented after coming into contact with warm water; 28 patients, 19 patients, and 1 patient presented with reflux >500 milliseconds in the great, small, and accessory saphenous veins, respectively. Eight patients and six patients had reflux >1 second in the femoral and popliteal veins, respectively.

RESULTS

All patients were treated with weekly Unna boots. Mean ulcer healing time was 2.12 weeks (range, 1-8 weeks; SD, ± 2.15 weeks). Patients with VV hemorrhage after contact with warm water had a mean healing time of 1.75 weeks, whereas those who bled without such exposure took an average of 3.5 weeks (P = .0426). Twenty patients underwent at least one endovenous thermal ablation procedure, with the average patient in the cohort receiving 2.16 procedures (range, 0-9; SD, ± 2.37). There was no significant difference between laterality, age, or sex between patients who bled after warm water contact and those who bled spontaneously. The ulcers recurred in three of the patients, and Unna boot treatment was reapplied until wounds healed once more. Patients had an average follow up of 7.2 months (range, 26 months; SD, ± 8.9 months), and we noted no recurrent bleeding episodes.

CONCLUSIONS

Spontaneous hemorrhage of VVs, although relatively under-reported, is not a rare occurrence. Risk factors are unknown; however, half of our patient cohort reported VV hemorrhage during or directly after coming into contact with warm water. Furthermore, these patients demonstrated a significantly shorter wound healing time compared with the rest of the cohort. Basic first aid, wound care, and hemostasis control education should be provided to all patients with VVs. Further investigation surrounding the risk factors associated with VV hemorrhage is warranted.

Iliac Vein Stent Placement and the Iliocaval Confluence

OBJECTIVE

Prior literature has recommended routine iliac vein stent extension into the inferior vena cava (IVC) to assure adequate outflow for iliac vein stenting procedures. Our bias was that only the lesion should be stented without routine stent extension up to the IVC. We report our experience with this limited stenting technique.

METHODS

From 2012 to 2015, 844 patients (1,216 limbs) underwent iliac vein stenting for nonthrombotic iliac vein lesions (NIVLs). All limbs were evaluated in accordance with the presenting sign of the Clinical-Etiology-Anatomy-Pathophysiology (CEAP) score, and duplex scans and intravascular ultrasound (IVUS) showing more than 50% cross-sectional area or diameter reduction. All study patients had failed 3 months of conservative management. The procedures of iliac vein stenting were all office based. Two techniques were compared: (1) placement of the iliac vein stent to cover the lesion and terminating cephalad into the IVC if the lesion involved the common iliac vein and (2) placement of the iliac vein stent to cover the lesion only and not passing the iliocaval confluence if the lesion only involved the external iliac vein. Complications were assessed during 30-day follow-up using the duplex scan technique to look for thrombosis.

RESULTS

Of the total 844 patients, 543 (64%) were women. The average age was 66 (±14.2) years (range, 21-99 years). The stent was placed in the left lower limb in 474 patients and bilaterally in 370 patients. The presenting sign in accordance with the CEAP classification was C3 = 626, C4 = 404, C5 = 44, and C6 = 141. The average iliac vein stenosis by IVUS was 62% (±12% standard deviation [SD]). We had 715 patients with the iliac vein stent extending into the IVC, and of these, 8 patients had thrombosis within 30 days after the procedure. On the other hand, 501 patients had the iliac vein stent without crossing the iliocaval confluence, and of these, 4 patients had thrombosis within 30 days of the procedure. There was no difference between these 2 groups in regard to gender (P = 0.1) or age (P = 0.3). Laterality was statistically different (P < 0.0001) with more stents to be extended into the IVC if the lesion is in the left lower limb. Comparing these 2 groups in regard to 30-day thrombosis as a complication was not statistically significant (P = 0.6). There was no statistical difference between the 2 groups in regard to the presenting sign CEAP (P = 0.6).

CONCLUSIONS

These results question the need for routine iliac vein stent extension into the IVC in patients with NIVLs. We were not able to demonstrate a significant risk of thrombosis with just placing the stent to cover the lesion only with short-term follow-up.

Clinical Experience and Management of Squat-Induced Lower Extremity Arterial Ischemia

Popliteal artery entrapment syndrome (PAES) is a rare cause of intermittent claudication in young patients. Unlike the atherosclerotic and degenerative etiologies typically associated with arterial disease, PAES is primarily of anatomic origin. PAES is rarely associated with aneurysmal disease. We present a case and subsequent surgical management of a 47-year-old male who experienced acute limb ischemia secondary to thrombosis of a popliteal artery aneurysm (PAA), who was found to have bilateral PAES and PAAs.

Radiofrequency Ablation Increases the Incidence of Endothermal Heat-Induced Thrombosis

BACKGROUND

Endovenous thermal ablation has become the procedure of choice in the treatment of superficial venous reflux disease. The current armamentarium of devices and techniques aimed at the elimination of saphenous reflux offers surgeons and interventionalists a variety of treatment options; however, there is a lack of data comparing the safety of these products. The most concerning complication after endovenous thermal ablation is endothermal heat-induced thrombosis (EHIT) due to the risk of progression to deep venous thrombosis. This study aimed to compare the incidence rate of EHIT between radiofrequency ablation (RFA) and endovenous laser therapy (EVLT).

METHODS

This was a single-center, office-based, retrospective study over the course of 5 years, in which 3,218 consecutive patients underwent 10,029 endovenous saphenous ablations. The patient cohort was 66.2% female, with an average age of 61.9 years. At the time of each individual intervention, 24, 212, 3,620, 4,806, 200, and 1,167 patients had Clinical-Etiology-Anatomy-Pathophysiology disease 1, 2, 3, 4, 5, and 6, respectively.

RESULTS

There was a total of 3,983 EVLT and 6,091 RFA procedures. The most common vessel treated was the great saphenous vein, 63.6% of the time, followed by the small saphenous vein (25.6%), accessory saphenous vein (6.1%), and perforator vein (4.6%). There were 186 cases of EHIT, with 137 (73.6%) identified as type 1 as per the Kabnick classification. Endovenous ablation performed via RFA resulted in significantly more cases of EHIT than of EVLT (109 vs. 77; P = 0.034; odds ratio = 1.52), which was confirmed by a multivariate analysis.

CONCLUSIONS

In the largest single-center study of endovenous saphenous ablations to date, RFA was shown to pose a significantly higher risk of EHIT than of EVLT.

Efficacy of balloon venoplasty alone in the correction of nonthrombotic iliac vein lesions

OBJECTIVE

Iliac vein stenting of nonthrombotic iliac vein lesions is an evolving treatment course for management of chronic venous insufficiency. To characterize these lesions, we examined our experience treating these lesions with balloon venoplasty before stenting.

METHODS

A retrospective analysis was performed to study all patients who underwent venograms with venoplasty and stenting of iliac veins from February 2013 to July 2016. All patients included in the study were treated with a trial conservative management for 3 consecutive months before venogram and, if indicated, venoplasty was performed. If a greater than 50% reduction in cross-sectional area or diameter was observed on intravascular ultrasound examination, the stenotic area was treated with balloon angioplasty, sized to nonstenotic distal vein segment (range, 10 × 40 mm to 16 × 60 mm). Intravascular ultrasound examination was also used to measure the area of stenotic iliofemoral veins before and after balloon angioplasty.

RESULTS

A total of 1021 venograms with venoplasty and stenting of iliac veins were performed in 713 patients from February 2013 to July 2016. The mean age of the study population age was 64.88 years (range, 21-99 years; standard deviation [SD], 14.57), with 451 female and 262 male patients. Before angioplasty, the mean cross-sectional stenotic area was 67.97 mm² (range, 6-318 mm²; SD, 34.87). After balloon angioplasty, the mean stenotic area increased to 78.80 (range, 6-334 mm²; SD, 44.50; P < .001). The targeted stenotic areas were categorized into three categories: group A, increased (>10% of baseline before venoplasty); group B, decreased (<10% of baseline), and group C, no area change (±10% of baseline). In 500 limbs (48.9%), the stenotic areas improved after venoplasty (average 36.99%), with a prevenoplasty average area of 60.81 mm² (SD, 32.80 mm²) and a postvenoplasty average of 96.52 mm² (SD, 49.85 mm²). In 294 limbs (28.8%), the area decreased (average 28.90%), with a prevenoplasty average area of 76.43 mm² (SD, 38.80 mm²) and a postvenoplasty average of 53.22 mm² (SD, 26.61 mm²). There were 227 patients (22.2%) who had the same area before and after venoplasty. Left-sided lesions had a greater increase in area than right-sided lesions (51.3% vs 46.2%, respectively; P = .048). No significant correlation of stenotic area response with age, presenting symptoms of Clinical, Etiology, Anatomy, and Pathophysiology (C2-C6), gender, or location of targeted lesion was observed.

CONCLUSIONS

Our data show there is a highly variable response after venoplasty of stenotic area of nonthrombotic iliac vein lesions. Balloon venoplasty showed greater improvement in improving the area of stenotic left-sided lesions. However, stenting of the lesions should be performed routinely owing to recoil and spasm in lesions.

Does Metformin Have an Effect on Stent Patency Rates

BACKGROUND

Metformin is the most commonly used drug for type 2 diabetes. Research has shown that metformin also has a protective effect on endothelium by decreasing endothelial vascular reactivity. We hypothesize that metformin will decrease restenosis/reintervention rates in patients receiving lower extremity non-drug-eluting stents (nDESs) in the superficial femoral artery(SFA) and/or popliteal artery.

MATERIALS/METHODS

Retrospective study was performed on 187 patients from October 2012 to December 2015 who received an nDES in the SFA and/or popliteal artery. Patients were divided into 3 groups (Table 1) and compared against for duplex based restenosis (>60%) rates, limb loss rates, and reintervention rates. Each patient's Trans-Atlantic-Inter-Society-Consensus II (TASC-II) class was collected. Postoperative duplex was performed 1 week after the procedure, then every 3 months for the first year, then, every 6 months to check for patency. IBM-SPSS-22 was used for all analyses.

RESULTS

Average age of the patients was 64.65 ± 73.4 years. 101 patients had 101 procedures performed on the left lower extremity; 86 patients had 86 procedures performed on the right lower extremity; 123 patients were male and 64 were female. Average length of follow-up was 13.1±9.7 months. Most common indication for intervention was claudication, followed by critical limb threatening ischemia. Restenosis and reintervention by groups can be seen in Table 1. No patients experienced limb loss. There were no statistically significant differences between any of the 3 groups and their limb loss, restenosis, or reintervention rates.

CONCLUSIONS

Despite having multiple proven effects in improving certain clinical outcomes and a proven protective effect on endothelium by decreasing endothelial vascular reactivity, metformin does not appear to reduce restenosis or reintervention rates in patients receiving lower extremity nDESs in the SFA and/or popliteal artery.

Bilateral iliac vein stenting reduces great and small saphenous venous reflux

Objective

Iliac vein stenting has been an evolving treatment option in the management of CVI secondary to iliac vein obstruction. Historically, treatment of CVI has been focused on the elimination of saphenous vein disease; however, the effect of reduction of iliac vein obstruction on superficial venous reflux remains largely unknown. This study aimed to identify the effect of iliac vein stenting on saphenous vein reflux.

Methods

In this retrospective study spanning course of five years, we performed 2681 venograms with venoplasties and stenting of the iliac veins. Pre-operative and post-operative venous mapping was performed via duplex ultrasonography. Patients who received any lower extremity vascular intervention between “pre-” and “post-stenting” duplex ultrasonography examination, other than iliac vein stenting, were excluded from analysis.

Results

One thousand six hundred forty-five patients, of which 63.2% were female, underwent iliac vein stenting; 1033 patients received bilateral intervention, whereas 356 and 259 patients received unilateral left and right stenting, respectively. The average age of the patient cohort was 66 (range 22–100; SD ± 13.9). The distribution CEAP scores of each limb at the time of intervention were: C2 (1%), C3 (25%), C4 (51%), C5 (5%), and C6 (18%). Bilateral iliac vein stenting significantly reduced reflux in the bilateral great saphenous and small saphenous veins by 363.8 ms ( p < 0.0001) and 345.4 ms ( p < 0.0002), respectively, but had no effect on ASV reflux. Unilateral stenting did not produce significant reductions in reflux, besides an average reduction of 573.2 ms ( p = 0.004) in the left great saphenous vein.

Conclusion

Bilateral iliac vein stenting decreased great saphenous vein and small saphenous vein reflux. Unilateral stenting did not demonstrate a significant reduction in saphenous reflux. Bilateral reduction in stenosis of the iliac veins may influence superficial venous reflux.

A real-world experience of drug eluting and non-drug eluting stents in lower extremity peripheral arterial disease

Objectives

Drug-eluting stents (DES) have been promoted as an alternative to the traditional non-drug eluting stents (nDES), and offer the potential for improved patency rates. However, DES are more expensive than nDES, and results comparing these stents outside of clinical trials have been limited.

Materials and methods

A retrospective review was performed on all in patient infrainguinal lower extremity endovascular procedures between January 2014 and September 2016, which involved stent implantation. Procedures involving the common femoral artery, superficial femoral artery, and above knee popliteal artery were included. Procedures involving iliac, below knee popliteal, tibial, peroneal, and pedal arteries were excluded. The type of stent, number of stents, length of each stent, and location of stent were recorded for each procedure. Data on each patients Trans-Atlantic Inter Society Consensus II class were collected. End-points included stent thrombosis, restenosis, re-intervention, and limb loss. Post-operative arterial duplexes were obtained every three months to determine stent patency during follow-up visits. In-stent stenosis was defined as >60% narrowing on arterial duplex. Thrombosis was defined as in-stent occlusion, and limb loss involved only major amputations in the treated extremity. Bivariate analysis and Students two-sample T-test were used to analyze the data. IBM-SPSS – 22 was used for all analyses.

Results

Two hundred and twelve patients underwent at total of 252 procedures during the study period. Of this group, 191 procedures met inclusion criteria. There were 21 lesions that were treated with both nDES and DES and they were excluded from further analysis. The average patient age was 73.2 ± 11.6 years; 68.6% had hypertension, and 58.1% had diabetes. Mean follow-up was 7.18 ± 7.96 months. The most common indication for intervention was claudication (53%), followed by critical limb threatening ischemia (47%); 124 procedures involved only nDES (Lifestent®)(Bard, Tempe, AZ), 46 procedures involved only DES (Zilver®) (Cook, Bloomington, IN). Comparison of nDES and DES showed the overall rate of thrombosis (11.1% vs. 16.7%, p = 0.81), overall rates of re-stenosis (48.2% vs. 46%, p = 1.0), re-intervention (13.7% vs. 14.3%, p = 1.0), and limb loss (9.7% vs. 0.0%, p = 0.38) was equivalent between the groups. The six-month primary patency rate for nDES and DES (41.9% vs. 40.0%, p = 1.0) was also equivalent. On average, the average lengths of nDES were longer than DES (19.2 ± 14.3 cm vs.11.4 ± 5.7 cm) ( p < .0001). DES results showed overall rates of 33% re-stenosis, 7.1% thrombosis, and no limb loss. There were no statistical differences between the nDES or DES groups with respect to gender, age, laterality, diabetes mellitus, coronary artery disease, gangrene, ulcers, hyperlipidemia, atrial fibrillation, deep vein thrombosis, claudication, critical limb-threatening ischemia, ipsilateral bypass, re-stenosis, thrombosis, limb loss, or ipsilateral amputation. Bivariate analysis showed a higher incidence of hypertension for nDES patients ( p = .001). There was no statistical difference between Trans-Atlantic Inter Society Consensus II classes and type of stent used ( p = .95).

Conclusions

In this retrospective analysis from one institution, the use of an nDES or DES did not result in a statistically significant difference in the rate of thrombosis, re-stenosis, ipsilateral re-intervention, or ipsilateral amputation over a two-year period when involving the CFA, SFA, and above knee popliteal artery.

Early hemodynamic characteristics of eversion and patch carotid endarterectomies

OBJECTIVE

Carotid endarterectomy (CEA) is currently the gold standard in the operative management of carotid artery stenosis. While eversion and patch CEAs vary greatly in technique, various studies have determined equivalence with regard to clinical outcomes. However, the hemodynamic differences following each procedure are not known. This study aimed to investigate any early hemodynamic differences between eversion and patch CEAs.

METHODS

All CEAs performed at our institution from March 2012 to June 2018 were aggregated in a retrospective database by querying the 35301 CPT code from the electronic medical record system. Variables collected included gender, age, laterality of CEA, type of procedure, and pre- and post-operative duplex ultrasound (DUS) date and quantitative findings. Exclusion criteria included any procedure with incomplete data, a post-operative DUS > 90 days following the procedure, CEAs with concomitant bypass(es), isolated external carotid artery (ECA) endarterectomies, and re-do CEAs.

RESULTS

One hundred and seventy-one CEAs were performed in 161 unique patients. There were 101 males and 60 females, with an average age of 69.7 (38-96; ± 9.36). 63 CEAs were excluded from analysis: 51 due to incomplete data, eight with a > 90 day post-operative DUS, 2 isolated ECA endarterectomies, 1 CEA with a carotid-subclavian bypass, and 1 re-do CEA secondary to an infected patch. Twenty-seven eversion and 81 patch CEAs were included in analysis. There was no difference in procedure laterality or gender between the two cohorts (p > 0.05); however, patients who received an eversion CEA were older on average (73.3 vs 67.5; p = 0.002). Pre-operative peak systolic velocities (PSV) of the proximal internal carotid artery (ICA), distal ICA, and distal common artery (CCA) were all similar (p > 0.05). Post-operative DUS was performed at 17.0 and 12.9 days in the eversion and patch CEA cohorts, respectively (p = 0.12). Post-operative PSV and change in PSV were similar for all three aforementioned segments (p > 0.05).

CONCLUSION

Although eversion and patch CEAs vary greatly in technique and post-procedure anatomy, there was no significant difference in post-operative PSV or change in PSV at or around the carotid bifurcation.

Radiation exposure during non-thrombotic iliac vein stenting

Objective

Fluoroscopic-guided interventions have become a major part of the modern vascular surgeon’s practice. Imaging is typically required to safely and effectively perform both simple and complex endovascular interventions. With an ever-increasing volume of fluoroscopic-guided interventions being performed each year, the minimization of harmful radiation exposure has become of paramount concern for both patients and providers. The purpose of this study was to identify the extent of radiation exposure associated with venography and iliac vein stenting, an intervention utilized in the management of chronic venous insufficiency.

Methods

This was a single-center, retrospective analysis of 40 venograms performed on 29 unique patients over a three-month period. Patients with signs and symptoms of chronic venous insufficiency who failed conservative therapy underwent evaluation of the vena cava and iliofemoral veins with venography and intravascular ultrasound. Stent placement was performed if a >50% cross-sectional area or diameter reduction was identified via intravascular ultrasound. All patients were found to have non-thrombotic iliac vein lesions. All patients wore two individual film badge dosimeters – one on their chest and the other on the abdomen. The same mobile C-arm system was used for all interventions.

Results

There were 15 males and 14 females, with an average age of 70.6 years old (SD ± 9.5; range 53–89) and a mean body mass index of 33.9 kg/m2. Sixteen limbs had C6 disease, 10 had C4 disease, and 14 had C3 disease. Thirty-eight of the 40 procedures resulted in stent placement, with an average of 1.13 stents placed per intervention. The average fluoroscopy time was 76.5 s (SD ± 36.9; range 7.8–209.5), and the mean cumulative air kerma was 1.08 mGy (SD ± 0.55; range 0.362–2.24). Average cumulative air kerma was higher in procedures resulting >1 stent placement compared to those with placement of ≤1 stent (1.44 vs. 1.02 mGy; p = 0.04). Fluoroscopy time was also higher in procedures with >1 stent placed (120.1 vs. 68.8 s; p = 0.0004). The mean deep dose equivalent per procedure from the patient-worn abdominal badge was 0.221 mSv.

Conclusion

With the adjunctive use of intravascular ultrasound, iliac vein stenting can be safely and effectively performed with very low utilization of fluoroscopy, and therefore radiation exposure can be minimized for both patients and surgeons. Placement of >1 iliac vein stent resulted in higher cumulative air kerma and fluoroscopy time.