Stem cell therapy in patients with thromboangiitis obliterans: assessment of the long-term clinical outcome and analysis of the prognostic factors.

BACKGROUND AND OBJECTIVES

The clinical benefits of stem cell therapy have been reported in patients with peripheral arterial occlusive disease. However, those studies had no standard reporting system to assess the outcomes, so we made a scoring system and assessed the outcomes of the limbs that underwent whole bone marrow stem cell (WBMSC) therapy.

METHODS AND RESULTS

Between July 4 and June 2009, 90 limbs of 67 patients with symptomatic thromboangiitis obliterans (TAO) were enrolled. Autologous whole bone marrow was implanted into the limb by intramuscular injections. The primary outcomes were defined by the clinical and angiographic improvement in all the limbs and the secondary outcomes were the clinical improvement and the amputation-free rates in the critical ischemic limbs (CILs). Clinical improvement and angiographic improvement was observed in 55.6% and 43.2% of all the limbs and in 50% and 50%of the CILs, respectively. The 1, 3 and 5-year amputation-free rates were 91.9%, 88.5% and 84.6% for all the limbs, respectively, and 83.9%, 77.5% and 70.4% for the CILs, respectively. A history of sympathectomy/sympathetic block was shown to be a negative prognostic factor for clinical improvement in all the limbs and in the CILs. In addition, a history of sympathetic block/sympathectomy and the smoking state were the major predictors of amputation for the CILs.

CONCLUSIONS

This study indicated that autologous WMBSC therapy improves the clinical status and reduces amputation factors in the limbs with symptomatic TAO and a history of sympathetic block/sympathectomy and the smoking state are useful prognostic factors.