Perceived Success and Failure of Intrathecal Infusion Pump Implantation in Chronic Pain Patients

Objectives. Over the past few years, there has been an increased reliance on the intrathecal delivery of drugs for patients suffering from intractable pain. We sought to demonstrate the effectiveness of the intrathecal pain pump by examining self‐reported pre‐ and postimplantation pain levels. Methods. Eighty‐four patients who had elected to implant a Medtronic SynchroMed 1 or 2 system in order to control their pain were asked to complete a survey. The survey consisted of pain ratings before implantation, pain ratings postimplantation, medications used before and after implantation, and patient satisfaction with the procedure. Results. Perceived success rate for implantation is 68%, when measured by the ability to reduce reliance on oral medication. When measured by willingness to undergo the procedure again, the success rate is 86%. Conclusions. Overall, the implantation of an intrathecal pain pump is an effective way for most people to manage their intractable pain and reduce reliance on oral medications.     

Management of Cancer-Related Pain With Intrathecal Drug Delivery: A Systematic Review and Meta-Analysis of Clinical Studies

BackgroundDespite increased attention paid to assessment and management, pain continues to be a prevalent and undertreated symptom in patients with cancer. Intrathecal drug delivery (IDD) is a therapeutic option that allows targeted delivery of analgesics to the intrathecal space.ObjectiveThe aim of this review was to examine the efficacy of managing cancer-related pain with IDD. Secondary objectives included the effects of IDD on systemic opioid use and infection rates.Evidence ReviewA systematic search of the literature published between 1990 and 2019 was performed to identify studies evaluating the efficacy and/or safety of IDD with external or implanted pumps in patients with cancer-related pain. Data were extracted and meta-analyses performed to determine the mean changes in pain levels at short-, mid-, and long-term intervals; changes in opioid (oral morphine equivalent [OME]) daily dose; and infection rates. Changes were assessed compared with baseline.FindingsPain levels were decreased from baseline: On a 0 to 10 scale, mean differences were −4.34 (95% CI [−4.93 to −3.75], p < 0.001) at 4 to 5 weeks; −4.34 (95% CI [−5.07 to −3.62], p < 0.001) at 6 to 12 weeks; and −3.32 (95% CI [−4.60 to −2.04], p < 0.001) at >6 months. Weighted mean OME consumption was reduced by 308.24 (SE = 22.72) mg/d. Weighted mean infection rates were ∼3% for external and implanted pumps.ConclusionsMeta-analyses show a statistically significant and sustained decrease in cancer pain with IDD, compared with baseline. Systemic opioid consumption was reduced on average by >50% after IDD. Infection rates were comparable with other indications.     

Severe Hypertension Following Accidental Clonidine Overdose During the Refilling of an Implanted Intrathecal Drug Delivery System

Background: Complications associated with intrathecal pumps may be linked to the surgical procedure, the implanted device, or the medication itself. Case Reports: Three patients treated chronically with intrathecal clonidine presented with clonidine overdose due to inadvertent extravasation during the refilling procedure. All patients experienced loss of consciousness and severe systemic hypertension that required aggressive parenteral treatment. Discussion: Clonidine is an alpha‐2 agonist with a nearly 100% bioavailability after oral or rectal administration. With high plasma concentration secondary to massive systemic overdose, the specificity for the alpha‐2 receptor is lost and an alpha‐1 agonist activity predominates and causes marked hypertension. Management of clonidine overdose consists of supportive therapy guided by signs and symptoms. Conclusion: Inadvertent injection into the subcutaneous pocket rather than the reservoir is rare but very dangerous as the drug cannot be retrieved and massive doses are involved. Signs and symptoms of systemic overdose with drugs commonly used in implanted drugs delivery system should be well known to ensure early diagnosis and treatment.     

The Effect of Measured Radiotherapy Dose on Intrathecal Drug Delivery System Function

ObjectivesRadiation therapy (RT) and intrathecal drug delivery systems (IDDS) are often used concurrently to optimize pain management in patients with cancer. Concern remains among clinicians regarding the potential for IDDS malfunction in the setting of RT. Here we assessed the frequency of IDDS malfunction in a large cohort of patients treated with RT.Materials and MethodsCancer patients with IDDS and subsequent RT at our institution from 2011 to 2019 were eligible for this study. Patients were excluded in the rare event that their IDDS was managed by an outside clinic and follow-up documentation was unavailable. Eighty-eight patients aged 22–88 years old (43% female, 57% male) representing 106 separate courses of RT were retrospectively identified. Patients received varying levels of radiation for treatment of cancer and cumulative dose to the IDDS was calculated. IDDS interrogation was subsequently performed by a pain specialist. Malfunction was recorded as deviation from the expected drug volume and/or device errors reported upon interrogation as defined by the manufacturer.ResultsTotal measured RT dose to the IDDS ranged from 0 to 18.0 Gy (median = 0.2 Gy) with median dose of 0.04 Gy/fraction (range, 0–3.2 Gy/fraction). Ten pumps received a total dose >2 Gy and three received ≥5 Gy. Eighty-two percentage of patients had follow-up with a pain specialist for IDDS interrogation and all patients underwent follow-up with a healthcare provider following RT. There were zero incidences of IDDS malfunction related to RT. No patient had clinical evidence of radiation related pump malfunction at subsequent encounters.ConclusionsWe found no evidence that RT in patients with IDDS led to device failure or dysfunction. While radiation oncologists and pain specialists should coordinate patient care, it does not appear that RT dose impacts the function of the IDDS to warrant significant clinical concern.     

Intrathecal Drug Delivery Systems for Cancer Pain Control: Insights on Current Contemporary Practices in the US

ObjectivesAmong patients with cancer with moderate to severe, intractable pain, intrathecal drug delivery using an intrathecal drug delivery system (IDDS) offers effective pain control. In this study, we evaluate the trends of IDDS therapy among patients with cancer, associated comorbidities, complications, and outcomes, using a large representative US administrative inpatient data base.Materials and MethodsThe Nationwide Inpatient Sample (NIS) data base contains data from 48 states and the District of Columbia. The NIS was used to identify patients with cancer who underwent IDDS implantation between 2016 and 2019. Patients with cancer with intrathecal pumps for the treatment of chronic pain were identified using administrative codes. Baseline demographics, hospital characteristics, type of cancer associated with IDDS implantation, palliative care encounters, hospitalization costs, length of stay, and prevalence of bone pain were evaluated in the study.ResultsA total of 22,895 (0.32%) individuals with hospital admission for IDDS surgery were included for analysis among 7.06 million individuals with cancer in the final cohort. The IDDS cohort consisted of patients predominantly in the 65-to-79 years age group (40.49%), female sex (50.42%), and Caucasian ethnicity (75.82%). The top five cancers in patients receiving IDDS were lung (27.15%), colorectal (24.9%), liver (16.44%), bone (8.01%), and liver (7.99%) cancer. In addition, the length of stay was six days (interquartile range [IQR] four–nine days) and the median cost of hospital admission was $29,062 (IQR $19,413–$42,261) in the patients who received an IDDS. These factors were greater than those in patients without IDDS.ConclusionsA very few patients with cancer received IDDS in the US during the study period. Despite recommendations supporting its use, there are significant racial and socioeconomic disparities in IDDS use.     

North American Neuromodulation Society Educational Curriculum for Intrathecal Drug Delivery Systems Implantation and Management

ObjectivesIntrathecal drug delivery systems (IDDSs) are used for the treatment of pain and spasticity. A wide range of educational criteria exist for these devices. The North American Neuromodulation Society (NANS) Education Committee developed a comprehensive IDDS curriculum to function as a standard for physician graduate education and assessment through training and into practice.Material and MethodsA multidisciplinary and diverse task force gathered by the NANS Education Committee met in person and virtually over several sessions and developed an IDDS curriculum modeling their previous work on spinal cord stimulation and following the Accreditation Council for Graduate Medical Education (ACGME) Milestones. There were iterative revisions and adaptations to the curriculum, and the final version was approved by the NANS Board of Directors.ResultsThe curriculum was developed with distinction between implanting physicians and managing physician and physicians who perform both tasks. There is a lateral temporal progression from early learner to practitioner, with advanced learner in the middle. In addition, there is a modular vertical organization that divides the curriculum into the six educational competencies outlined by the ACGME.ConclusionA comprehensive, modular, graduated, and segmented educational curriculum for IDDSs was developed by NANS. We propose the curriculum to be the standard for guidance and assessment of trainees and physicians pursuing training in implanting or managing IDDSs.     

Initiation of Intrathecal Drug Delivery Dramatically Reduces Systemic Opioid Use in Patients With Advanced Cancer

ObjectivesPain is common in cancer, affecting more than 70% of patients with advanced disease. Intrathecal drug delivery systems (IDDS) are a well-established treatment for patients with refractory cancer pain, improving pain control and reducing associated side effects. To date, details of systemic opioid use before and after IDDS implant have not been reported.Materials and MethodsWe conducted a retrospective review of patients at Huntsman Cancer Institute-University of Utah treated with IDDS for cancer pain from May 2014 to May 2018. Oral, transdermal, and parenteral opioid use before IDDS implant was compared to use 30 days postoperatively.ResultsA total of 173 patients were included, 93% with stage IV disease. The pre-implant median daily oral morphine equivalent (OME) was 240 mg (interquartile range 130–390, range 0–2616 mg). OME doses >200 mg/day were required by 57% of patients, and >500 mg OME by 19% of patients. The post-implant median OME was 0 mg (interquartile range 0–0, range 0–480 mg) and 82.6% of patients discontinued systemic opioids completely. 11.0% of patients used <100 mg OME, and only 1.7% of patients used >200 mg OME. Mean OME decreased by 94% following IDDS implant (p < 0.0001) and all patients who continued to use systemic opioids required a lower OME compared to pre-implant.ConclusionsIn the largest cohort of patients with advanced cancer and refractory pain treated with IDDS, implantation was associated with a dramatic reduction in systemic opioid use 30 days postoperatively, with a large majority of patients discontinuing systemic opioids. Those patients that continued systemic opioids utilized significantly lower doses as compared to their pre-implant dose.     

Prevention of Intrathecal Drug Delivery Catheter‐Related Complications

In an effort to improve the performance of implantable intrathecal drug delivery systems, a group of physicians experienced in the management of such devices reviewed surgical practices and principles that were associated with low catheter‐related complication rates. Clinical study and postmarket data identified physicians whose patients experienced a relatively low rate of catheter‐related complications. Six of those physicians (three anesthesiologists and three neurosurgeons) reviewed the number and types of intrathecal drug pumps and catheters they had implanted, with an emphasis on the specific details of successful catheter implantation techniques. The authors pooled their experiences to reach a consensus on implant techniques that are associated with a low rate of postoperative complications. The authors found that complications were minimized by the use of specific methods for catheter placement that included: a mid‐to‐upper lumbar dural entry level, a shallow‐angle paramedian oblique insertion trajectory, and meticulous catheter anchoring and tunneling techniques. Systemic antibiotic prophylaxis, attention to pump pocket location, and surgical wound closure techniques also were important in reducing the incidence of postoperative device‐related complications. Their experience indicates that specific implantation techniques using a variety of catheters and accessories can be expected to reduce the incidence of complications after implantation of intrathecal drug administration systems.     

Intrathecal Drug Delivery for the Treatment of Cancer-Associated Chronic Pain in Children

ObjectivesManagement of refractory cancer-associated pain can be particularly challenging. Regional anesthesia is an alternative modality to treat acute and chronic refractory pain. Intrathecal (IT) drug delivery of opioids and other adjuncts has been used to treat refractory cancer-associated pain. This method has been shown to be relatively safe and effective, often associated with fewer systemic side effects when compared to oral or IV opioid administration. While intrathecal drug delivery systems (IDDS) are regularly used in the adult cancer population for the treatment of refractory, chronic pain, there is limited evidence of similar use in the pediatric setting.Materials and MethodsWe performed a systematic review using conventional Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology to identify studies reporting IT drug delivery for the treatment of pediatric cancer-related pain. The primary outcome was satisfaction with analgesia categorized as “satisfactory” or “unsatisfactory.” Functional benefits, previous systemic pharmaceutical interventions, previous non-IT regional interventions, indication for IT drug delivery, IT drugs used, and method of delivery were collected.ResultsA total of 11 studies were identified, describing 16 patients with cancer-related pain treated with IT drug delivery. The average age of the cohort was 12.25 years, with ages ranging from 3 to 19 years. Most patients were adolescent (10/16). All patients had cancer diagnoses, with most patients suffering from solid tumor pain (14/16). Nearly all patients achieved satisfactory analgesia through IT drug delivery (15/16) and most reported functional benefits in addition to analgesia (13/16). Majority received IT drugs via external catheters (9/16). One severe complication of respiratory depression was reported, which resolved following naloxone administration.ConclusionsThere exist children with cancer whose pain is refractory to the standard approaches and may benefit from IT drug delivery. The existing data, although limited and of low tier evidence, suggest that IT drug delivery has been effective in the pediatric cancer population.     

Complications of Intrathecal Drug Delivery Systems

Objectives. To report complications associated with implant of the intrathecal drug delivery systems (IDDS). Patients and Methods. A retrospective review of the implant database was undertaken to determine various complications associated with the IDDS. A total of 122 patients were reviewed, 97 included in the final analysis, 25 excluded due to incomplete data. The complications of excluded patients were reviewed separately. The complications were divided in to categories pharmacologic, equipment, procedural, programming errors and psychological. The drugs used were morphine, dilaudid, fentanyl, sufentanil, baclofen, and marcaine. Results. There were 60 men and 37 women. A total of 43 patients reported various complications. Most common were transient pharmacologic side effects (n= 33), procedural (n= 5), equipment (n= 16), programming (n= 2), and psychological (n= 3). The most serious procedural complication was Staphylococcus aureus meningitis (n= 1). Catheter disconnection and leakage was noted in (n= 6) patients. Two programming errors were related to increase in drug concentration with failure to reduce the dose. Seven pumps were explanted, including three due to distorted body image. Conclusion. IDDS are effective and safe devices for pain management. The complications associated with implants are mostly pharmacological and transient.     

Effectiveness and Safety of Intrathecal Drug Delivery Systems for the Management of Cancer Pain: A Systematic Review and Meta-Analysis

ObjectivesIntrathecal drug delivery systems (IDDS) and spinal cord stimulation (SCS) have been proposed and assessed for the management of cancer pain; however, such treatments remain underused. We conducted a systematic review to evaluate the effectiveness and safety of IDDS and SCS for cancer pain.Materials and MethodsElectronic databases MEDLINE, CENTRAL, EMBASE, and WikiStim were searched from 1988 to March 2021. Randomized controlled trials and observational studies of adults with pain related to cancer or its treatment who received an implantable IDDS or SCS were eligible for inclusion. The primary outcome of the review was change in pain intensity from baseline to the last available follow-up, measured using a visual analog scale or numerical rating scale. The protocol for this review is registered on PROSPERO (CRD42021240717).ResultsA total of 22 studies (24 reports) included a total of 3043 participants who received either IDDS or SCS for cancer pain. Eight studies reporting data for 405 participants with an IDDS could be included in the meta-analysis of pain intensity that showed a statistically significant reduction at the latest posttreatment follow-up time compared with baseline (mean difference [MD], −3.31; 95% CI, −4.18 to −2.45; p < 0.001). Six studies reporting data for 325 participants with an IDDS could be included in the meta-analysis of pain intensity that showed a statistically significant reduction up to one month after treatment compared with baseline (MD, −3.53; 95% CI, −4.06 to −3.00; p < 0.001). A meta-analysis including studies of participants with either an IDDS or an SCS device showed similar results. Improvements in other outcomes following implantation of IDDS also were observed. Postdural puncture headache was the most reported complication, whereas urinary retention, nausea, and vomiting were commonly reported side effects.ConclusionOur findings suggest that IDDS is effective in reducing pain intensity for patients with cancer pain when compared with pretreatment.