ObjectiveTo assess the long-term effectiveness and safety of autologous bone marrow mononuclear cells (BM-MNC) transplantation in the treatment of critical diabetic lower arteriosclerosis obliterans (ASO). MethodsBetween January 2007 and January 2010, 61 patients with critical diabetic lower ASO were treated with standard medical therapies in 29 cases (control group) or with standard medical therapies and autologous BM-MNC transplantation in 32 cases (treatment group). There was no significant difference in gender, age, disease duration, Fontatine stage, glucose (GLU), triglyceride (TG), total cholesterol (CHOL), low-density lipoprotein-cholesterol (LDL-C), hemoglobin A1c (HbA1c), systolic blood pressure (SBP), and diastolic blood pressure (DBP) between 2 groups (P>0.05). The endpoints were overall survival (OS) and amputation-free survival (AFS). The risk indexes for ASO were observed and compared between 2 groups before and after treatments. ResultsThe patients were followed up 2-36 months, and no malignant tumor occurred. The OS rate, OS time, AFS rate, and AFS time were 82.76% (24/29), (32.31±9.08) months, 37.50% (9/24), and (21.28±13.35) months in the control group and were 78.13% (25/32), (32.47±6.96) months, 68.00% (17/25), and (28.38±9.48) months in the treatment group;all indexes showed no significant differences (P>0.05). OS rate, OS time, AFS rate, and AFS time showed no significant differences between 2 groups at the other time (P>0.05) except AFS time at 1 year, which was significantly short in the control group than the treatment group (t=2.806, P=0.007). At the endpoint of follow-up, the indexes of GLU, TG, CHOL, LDL-C, HbA1c, SBP, and DBP showed no significant differences between before and after treatments and between 2 groups (P>0.05) in 49 survival patients (24 in control group and 25 in treatment group). ConclusionAutologous BM-MNC transplantation is safe and effective in the treatment of critical diabetic lower ASO, which can significantly improve AFS rate and prolong AFS time with no risks.