Background Patients with a FBSS suffer from chronic severe back pain. Most of these patients have had a postlaminectomy in the lumbosacral region. 10% of patients with a postlaminectomy develop chronic pain after the surgery. The percentage of positive outcomes after a re-surgery amount about 30–75%. In general the outcome of these patients is unfavourable. At present pain therapy with opioids is not generally recommended in patients with FBSS.

Objectives Documentation of long-term efficacy and safety of fentanyl TTS treatment for patients who have had at least one surgical intervention for chronic back pain and who continue to suffer from severe back pain.

Methods Subgroup analysis of an open, international, multi-centre study (FEN-INT-13) with a duration of 12 months. 85 patients (mean age 50 years; 46 women; mean pain duration 9 years) with failed back surgery syndrome received fentanyl TTS in an initial dosage of equivalent analgesic strength to prior opioid therapy. The dose was subsequently adjusted to provide optimum pain therapy. Visits have been scheduled day 1, week 1, month 1–12. The primary target parameter was the subjective weekly assessment of pain control (very good, good, moderate, poor, very poor). In addition the treatment preference with regard to the prior analgesic treatment and the quality of life (SF-36) has been documented. Regarding the safety unexpected events and vital parameters have been documented.

Results 59% of the patients were treated for 12 months, 41% discontinued treatment earlier (5% because of inadequate effect, the rest for other reasons). The primary target parameter of subjective weekly assessment of pain control was consistently rated very good to moderate (50 to 80%). 77% of patients preferred fentanyl TTS to the former opioid therapy. There was a significant improvement in SF-36 (quality of life) after 12 months in terms of physical pain, mental health, average pain intensity and pain frequency. The mean fentanyl TTS dose was 67 μg/h in month 1, 90 μg/h in months 6 and 97 μg/h in month 12. The most frequently reported adverse reactions caused by fentanyl TTS (>10%) were nausea, vomiting, headache, increased perspiration, constipation, drowsiness, fatigue, dizziness and depression.

Conclusion In this trial patients with chronic, therapy-resistant back pain showed benefit of a treatment with fentanyl TTS. There was not only pain reduction but also improvement in quality of life over a period of one year. At the same time the dosage of fentanyl remained stable. The success of this pain therapy may offer the possibility to initiate a causal therapy like physiotherapy. Fentanyl TTS offer stable pain control for failed back surgery syndrome patients and improves their quality of life. It is safe and well tolerated.