Background: Intrathecal (IT) drug therapy with implanted pumps is an effective treatment
modality for chronic pain and/or spasticity, especially after non-invasive treatment has failed.
Long-term use of intrathecal opioids may cause formation of inflammatory masses at the tip of
intrathecal catheters, possibly leading to neurological deficits and/or catheter revision.
Objective: We aimed to identify risk factors for catheter-tip granuloma (CG) formation.
Study Design: Retrospective study.
Setting: Tertiary Spine Centers in Germany and Switzerland
Methods: We retrospectively reviewed data at 2 Swiss centers (Kantonsspital St. Gallen, Swiss
Paraplegic Centre Nottwil) between 01/1994 and 10/2013. Collected data were age at operation,
gender, smoking status, previous spinal operations, spinal level of catheter-tip, clinical symptoms,
catheter testing with contrast agent, applied drugs, drug concentration, as well as cumulative daily
drug dosages.
Results: Thirteen patients with a mean age of 52.6 years and CG formation after a mean of
6.9 years of follow-up were identified and compared to 54 patients of similar age and length of
follow-up (48.6 years, P = 0.535; follow-up 5.3 years, P = 0.236) without CG. In the analysis of risk
factors, catheter ending in the middle thoracic spine (Th4-8; 38.5 vs. 6.5%; P = 0.010), previous
spinal surgery (75 vs. 41%; P = 0.051), and chronic pain as an underlying primary symptom for IT
drug therapy (100 vs. 56%, P = 0.003) were associated with CG formation. IT drug therapy for
spasticity appeared to be much less associated with CG formation (0 vs. 44%, P = .0003). As the
symptomatology is closely related to the medical treatment applied, patients with CG were more
likely to be treated with IT morphine (77 vs. 20%; P < 0.001), and as tendency with IT clonidine
(54 vs. 26%; P = 0.092) and IT bupivacaine (46 vs. 20%; P = 0.077). Average in-pump morphine
concentration (30.3 vs. 19.5 mg/mL; P = 0.05) as well as average daily dose of morphine (12.5 vs.
6.2 mg/d; P = 0.037) were significantly higher in the CG group. Smoking could not be identified
as risk factor for CG formation.
Limitations: Limitations include the retrospective approach, the limited group size of granuloma
patients, as well as missing data in the investigated patient groups.
Conclusion: Our patient cohort with CG differed in some features, of which some like catheter
localization, choice, dosage, and the concentration of drugs are potentially modifiable. These
results could contribute to the prevention of CG in the future.
Key words: Intrathecal drug delivery, intrathecal cathether-tip granuloma, intrathecal cathethertip inflammatory masses, intrathecal morphine, drug pump complications
Catheter-tip Granulomas Associated with
Intrathecal Drug Delivery – A Two-Center
Experience Identifying 13 Cases