Intraoperative peripheral Nd:YAG laser-assisted thermal balloon angioplasty: short-term and intermediate-term follow-up. Laser-assisted thermal balloon angioplasty was performed in 48 arteries (iliac, superficial femoral, and popliteal). Indications for surgery were limb salvage (25%), rest pain (38%), and claudication (38%). Patients were categorized into three groups: lesions less than 5 cm, greater than 5 to 10 cm, or greater than 10 cm in length. Demographic characteristics, risk factors, and outcome measures were compared by use of Fisher's exact test and Student's t test. The time for vascular patency failure was compared by use of a standard Kaplan-Meier survival analysis for the three groups. Initial failure to recanalize was noted in 14% in lesions less than 5 cm, 40% in lesions greater than 5 to 10 cm, and 73% in lesions greater than 10 cm. The overall success rate was 38%, with a mean follow up of 1 year. The less than 5 cm lesion group had a significantly higher rate of overall success (59%, p = 0.005) than the other two groups combined. The greater than 10 cm lesion group did significantly worse (9%) than the other two groups combined (p = 0.028). Patients in the less than 5 cm group had significantly longer patency than the other two groups (p less than 0.01). Iliac lesions had a higher overall success rate (73%) than superficial femoral and popliteal artery lesions (35%) (p = 0.038). In conclusion, the widespread application of laser-assisted thermal balloon angioplasty cannot be justified without further long-term clinical and laboratory investigation. Conversely, the potential of this technique should not be dismissed out of hand. Proper patient selection, length and nature of the lesion to be treated, and the appropriate forms, doses, and method of delivery of laser energy, remain to be defined. 