[Initial experiences with implantable pump systems for intrathecal therapy of chronic pain conditions]

The therapeutic concept of local administration of opioids into the perimedullar and cerebrospinal fluid is the result of fundamental studies concerning the discovery and localization of specific binding sites. These studies provoked considerable clinical interest, because they suggested a non-destructive and fully reversible method. In our department we have been gathering experience with an implantable pump system for various indications of chronic pain on a sample of 25 patients. The first implantation was performed in February 1987 and the latest included in this study in February 1991. The sample of patients consisted of two groups: (A) Chronic non-malignant pain (13 cases), (B) Chronic pain due to cancer (12 cases). We used two different pump devices: the gas-filled continuous infusion pump (Infusaid, Mod. 400) in 10 cases and the manually tractable micro pump (Cordis) in 15 cases. In 23 cases we decided in favour of an intraventricular drug administration, mainly because of the site of the pain; in each of these a ventricular catheter was placed in the frontal horn of the lateral ventricle. In the remaining two cases, the catheter was placed intraspinally, the catheter tip terminating at thoracic segments. Nine of the patients with cancer-related pain experienced from excellent to acceptable pain relief, as did also 10 patients with chronic non-malignant pain. Side effects were rare. Our findings also indicate that, in carefully selected patients, both malignant and non-malignant pain may be managed satisfactorily with this technique.