How should we treat May–Thurner syndrome and other causes of iliac vein obstruction? Examining the evidence

Clinical outcomes of different endovenous procedures among patients with varicose veins and iliac vein compression: A retrospective cohort study

OBJECTIVE

This study aimed to investigate the short-term outcomes of three endovenous procedures in patients with varicose veins (VVs) and severe iliac vein compression syndrome (IVCS).

METHODS

A total of 158 consecutive patients were included in this multicenter retrospective study from May 2017 to December 2019; 54 patients underwent endovenous laser ablation (EVLA) alone, 47 patients underwent EVLA and balloon angioplasty (BA), and 57 patients underwent EVLA and stenting angioplasty (SA). Clinical outcomes and complications were assessed at one and twelve months post-surgery. The Quality of life (QoL) was assessed by the venous clinical severity score (VCSS) and Aberdeen Varicose Vein Questionnaire (AVVQ).

RESULTS

Patients who underwent the SA procedure were older (P < 0.05). Incidence of laser ablation complications was similar among the three procedures; closure rates of the great saphenous vein were 96.8%, 98.0%, and 98.4%, respectively, at 12 months. Reflux times in the SA procedure were lower than those in the EVLA and BA procedures at 12 months, while ulcer healing time was faster with the SA procedure (P < 0.05) than with the other procedures. The VCSS and AVVQ values were significantly improved post-procedure (P < 0.05), with lower AVVQ scores in the SA procedure than in the EVLA and BA procedures at 12 months post-surgery. The EVLA and BA procedures (stenosis >70%) caused a significantly higher symptom recurrence than the SA procedure, with an odds ratios of 14.04 (95% confidence interval (CI), 1.99-99.18) and 10.50 (95% CI, 1.26-87.15), respectively.

CONCLUSIONS

Our results demonstrate that EVLA and SA procedures relieve symptoms, improve the QoL, and decrease symptom recurrence in patients with VVs and severe IVCS (stenosis >70%).

Pelvic kidney as a cause of May-Thurner syndrome

Deep venous thrombosis is a common clinical problem with significant morbidity and mortality. Since the iconic publication by Virchow in 1856, which placed all known causes of deep venous thrombosis into three groups, namely venous stasis, vascular injury and hypercoagulability, numerous causes have been added to each category. This case report highlights the importance of an anatomical imaging study of the pelvis in cases of recurring, proximal deep venous thrombosis of the lower limb.

Study on the Patency of the Contralateral Iliac Vein After Stenting Across the Iliocaval Confluence With an Experimental In Vivo Model

OBJECTIVE

Stenting is the preferred treatment for iliac vein lesions. For the treatment of occlusions in the junction of the iliac vein and the inferior vena cava (IVC), the stent needs to be positioned in the IVC to cover the lesion. However, the pathological changes in the contralateral iliac vein due to stent coverage on its ostium remain unclear. We observed the patency of the contralateral iliac vein via animal experiments.

METHODS

The stents were placed in the left iliac vein and extended into the IVC in 8 beagle dogs. Doppler ultrasonography, angiography, and histopathological examination were used to assess the patency and histopathological changes in the contralateral iliac vein.

RESULTS

Angiography showed patency of the contralateral iliac vein and no sign of thrombosis or stenosis. Twelve months after stenting, Doppler ultrasonography showed a stenotic change in the ostium of the contralateral iliac vein. The histopathological examination showed that the stent strut at the ostium of the contralateral iliac vein was mostly covered by the intima, and the cross-sectional stenosis rate was greater than 60%.

CONCLUSIONS

The coverage of the iliac vein stent on the ostium of the contralateral iliac vein does not cause complete occlusion of the contralateral vein but can cause significant stenosis at the ostium of the contralateral iliac vein, which is considered to be a potential risk factor for thrombosis.

Influence of Iliac Vein Stent Implantation on the Contralateral Iliac Vein

OBJECTIVES

Stent implantation is frequently used to treat iliac vein occlusion. However, the recommended extension of the stent mesh into the inferior vena cava (IVC) may affect blood flow through the contralateral iliac vein. We analyzed the influence of iliac vein stent extension on contralateral iliac vein patency and neointima formation in a dog surgery model.

METHODS

Bare stents were implanted into the left iliac veins of 12 beagles with the proximal end covering the opening of the contralateral iliac vein. Blood flow was measured by color Doppler 4, 8, and 12 weeks postoperation. At each measurement point, a subgroup was killed, and the stents and veins were removed for pathological examination.

RESULTS

Stents were successfully implanted, and there was no immediate stent occlusion or iliac vein thrombus by color Doppler examinations. Contralateral blood flow was maintained with no obvious abnormalities for 12 weeks. Neointima formed and advanced toward the center of the stent, but small coverage of the contralateral iliac vein opening did not change significantly with time postoperation (9.33% ± 1.54% at 4 weeks, 10.65% ± 1.01% at 8 weeks, and 10.92% ± 1.30% at 12 weeks; P > .05). Scanning electron microscopy showed neointima covering the surface of stent wires at the opening of the contralateral iliac vein, which did increase with time: 63.58% ± 12.39% at 4 weeks, 97.13% ± 2.71% at 8 weeks (P < .001 vs 4 weeks), and 99.63% ± 0.60% after 12 weeks (P > .05 vs 8 weeks; P < .001 vs 4 weeks). The neointimal coverage rate of the meshes increased obviously with time. However, no neointima was found forming a mesh between stent wires.

CONCLUSION

Although there was intimal hyperplasia on the rim of the bare stent in the IVC, expansion was limited and did not block the opening of the contralateral iliac vein. The stent had no obvious influence on blood backflow in the contralateral iliac vein.