Interventional Treatment Of May-Thurner Syndrome

As early as 1906, McMurrich noted the presence of intraluminal valve-like strictures in left common iliac vein. He proposed a congenital origin of the lesion causing left iliofemoral vein thrombosis. May and Thurner, in 1956, described anatomic variations of the left common iliac vein that resulted in lower extremity venous outflow obstruction in cadavers. Fibrous vascular lesions called spurs were found at the level where the right artery compressed the left iliac vein against the fifth lumber vertebra. In 1965, Cockett and Thomas reported a clinical entity of iliofemoral venous thrombosis with iliac vein obstruction. The majority of these patients were found to have an involvement of the left lower extremity, and of those who underwent surgical exploration showed that fibrous obstruction of the left iliac compression, a myriad of symptoms, related to venous obstruction including acute DVT, chronic unilateral leg edema, pain and varicosities, can be developed. This condition has been already named as May-Thurner syndrome, iliac vein compress syndrome, or Cockett syndrome. A variety of therapies that have been used to correct the obstruction and relieve symptoms are ineffective. Most recently, endovascular therapies, including balloon dilatation and stent placement, have been developed as a minimal invasive treatments to accomplish the same goals.The purpose of this study was to present the results of iliac venous angioplasty with stent placement in the management of May-Thurner syndrome.All forty-six patients are divided into two groups. Balloon dilatation and stent placement were performed in one group with 21 cases (Interventional Treatment Group, ITG) and warfarin was given to another group with 25 cases (Anticoagulation Treatment Group, ATG) for the relief of iliac vein stenoses. All procedures were performed from January 2003 to July 2006.ITG: 1 limb was in C2(C1-C6, CEAP classification for chronic venous disorders), 2 limbs in C3, 6 limbs in C4, 4 limbs in C5 and 8 limbs in C6 (8 men and 13 women; mean age 55.9 years). There were 18 limbs in left side and 3 limbs in right side.ATG: 5 limbs were in C2, 3 limbs in C3, 7 limbs in C4, 4 limbs in C5 and 6 limbs in C6 (10 men and 15 women; mean age 52.3 years). There were 22 limbs in left side and 3 limbs in right side.All cases were revealed by phlebography. In ITG, balloon dilatation and stentplacement were performed in 19 cases and simple balloon dilatation was completed in 2 cases. In ATG, warfarin was given to 25 cases, monitoring and adjusting INR regularly (maintain INR 1.5-2).All forty-six cases were followed-up for 11 to 36 months (mean, 13.2 months).In ITG, the 19 cases had a quick recovery after balloon dilatation and stent implantation. Only in 2 cases with simple balloon dilatation the symptom was persisted, and iliac venous stenoses recured in re-phlebography in these two cases. The measurement of pressure differentials of iliac vein was done in ten cases before and after the intervention, and shown pressure difference at 0 to 2.2 cmH₂O(mean, 1.19 P<0.05). It means that interventional therapy can significantly reduce the gradient between the inferior vena and the iliac vein and benefit for keeping iliac vein open. Color coded duplex scanning revealed patency rate at 95.2% in twelve months after interventional treatment.In ITG, small bleeding in gum in 8 cases and menses getting longer in 5 cases were seen.After average thirteen months of follow-up, extremity edema rate was examined as following: decreased from 81% to 15% in ITG and from 24% to 25% in ATG (ITG vs. ATG, P< 0.05). This shown interventional treatment can significantly relieve extremity edema. Active limb ulcer rate was examined as following: decreased from 38% to 10% in ITG and from 24% to 25% in ATG (ITG vs. ATG, P> 0.05). Leg pain rate was examined as following : decreased from 19% to 5% in ITG and from 20% to 21% in ATG (ITG vs. ATG, P> 0.05). The active limb ulcer and leg pain were shown to have a trend to cure, but have no statistical significance compared ITG with ATG The reason may be the main symptoms, which are not the ulcer and pain in May-Thurner syndrome, or the sample number of this study is not large enough to obtain a statistical difference. Varicose veins was examined as following: decreased from 90% to 70% in ITG and remained at 92% in ATG (ITG vs. ATG, P> 0.05). This shows varicose veins can be cured only in a small number of patients treated with interventional therapy because of short term follow-up.In summary, endovascular venous stenting in May-Thurner syndrome is technically feasible, and leads to reduction of symptoms in the majority of patients with high stent patency rates. This approach may be superior to traditional anticoagulation therapy in the short-term.