A technique for the insertion of an implantable portal system for the long-term epidural administration of opioids in the treatment of cancer pain.

The feasibility of using a subcutaneously implanted portal system attached to a conventional 16-gauge epidural catheter has been evaluated in 50 patients with sever pain associated with cancer. This technique allowed for the percutaneous epidural administration of morphine at 8-12-hourly intervals for pain control. The mean duration of implantation was 12 weeks and the longest period a portal remained in situ was 36 weeks. Five portals had to be removed for various reasons. The injection system has blocked on eight occasions due to catheter blockage (six times) and portal blockage (two occasions). These patients have continued to obtain excellent analgesia when either catheter or portal were replaced. In a cadaver, 300 injections were simulated using either 22-gauge Huber point needles or disposable needles (25 gauge) and the injectate examined by both light and scanning electron microscopy. Both needle types resulted in particulate contamination which was greater with the recommended Huber point needles.