Case report of semi-implantable IDDS for advanced cancer pain in three patients

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Frontiers in Medicine Published April 16, 2026 Medically reviewed April 25, 2026 DOI ↗ By Dr. Julia Lee, PhD · Oncology, Genomics & Drug Development

Key Takeaway

Consider semi-implantable IDDS as a cost-effective palliative option for advanced cancer pain with life expectancy 3-6 months.

This case-based study reports on three representative cases of patients with advanced cancer pain who underwent semi-implantable intrathecal drug delivery system (IDDS) implantation within a digital subtraction angiography (DSA) suite. The primary outcome measured analgesic efficacy using the Visual Analog Scale (VAS) score, while secondary outcomes included technical challenges such as placement verification, mechanical failures, and opioid dependency. The authors synthesize findings from these limited cases to evaluate the feasibility and immediate effects of this intervention.

Preoperative VAS scores, which ranged from 8 to 10, decreased to 0 to 4 within 24 hours and stabilized at 0 to 1 after 72 hours. Regarding safety, no infectious complications occurred during the follow-up period, which lasted up to 8 weeks. However, Case 3 experienced acute psychological withdrawal symptoms, with a COWS score of 14. The study does not report serious adverse events, discontinuations, or overall tolerability.

The authors conclude that the semi-implantable IDDS serves as a crucial, cost-effective palliative option for patients with advanced cancer pain and a life expectancy of 3 to 6 months. Given the small sample size and the observational nature of this case report, the findings should be interpreted with caution. Further research is needed to confirm these benefits and assess long-term safety and efficacy in broader populations.

Study Details

Study typeSystematic review

EvidenceLevel 1

PublishedApr 2026

View Original Abstract ↓

ObjectiveThis study investigated the clinical efficacy, technical risks, and management strategies of the semi-implantable intrathecal drug delivery system (IDDS) as a “fourth-step” analgesic regimen for refractory advanced cancer pain.MethodsWe retrospectively analyzed three representative cases of patients with advanced cancer pain who underwent semi-implantable IDDS implantation under fluoroscopic guidance in a digital subtraction angiography (DSA) suite.The study was approved by the Institutional Review Board (IRB), and all patients provided written informed consent. Analgesic efficacy was assessed using the Visual Analog Scale (VAS) score. Technical challenges—including placement verification without cerebrospinal fluid (CSF) backflow, mechanical failures, and opioid dependency—were evaluated to develop standardized management protocols.ResultsSignificant analgesia was achieved in all cases. Preoperative VAS scores (8–10) decreased to 0–4 within 24 hours and stabilized at 0–1 after 72 hours. Specific technical risks were successfully mitigated through individualized strategies:Placement verificationIn a cachectic patient (Case 1) with an iodine contrast allergy and absent CSF backflow, a “morphine test dose” (0.1 mg bolus) was utilized as functional confirmation of subarachnoid placement, justified by the rapid 10-minute analgesic onset.Mechanical issuesRepeated occlusion alarms in Case 2, caused by pressure sensitivity at the device’s minimum flow rate (0.1 mL/h), were resolved by diluting the drug concentration to increase the basal flow rate and implementing a “U-shaped” redundant catheter loop at the port site.Opioid withdrawalCase 3 developed acute psychological withdrawal symptoms (COWS score: 14) following the rapid reduction of high-dose systemic opioids. This was managed through a multidisciplinary cross-titration protocol involving oral oxycodone and cognitive behavioral therapy. No infectious complications occurred during the follow-up period (up to 8 weeks).ConclusionThe semi-implantable IDDS serves as a crucial, cost-effective palliative option for patients with advanced cancer pain and a life expectancy of 3–6 months. While its externalized design introduces technical risks, these can be effectively managed through high-resolution fluoroscopy-guided placement, flow-rate optimization, and multidisciplinary support. Standardized troubleshooting algorithms and strict patient stratification are essential to achieve the goal of “pain-free survival.”