This case illustrates the complexities of using an intrathecal medication pump in a 52-year-old woman with a history of severe neck and bilateral arm pain secondary to complex regional pain syndrome (CRPS). Historically, long-term management of chronic noncancer pain has been accomplished with oral analgesics, specifically opioids. After many years of continuous use, the daily dose can escalate to a point of intolerable side effects or ineffective pain control.1 Intrathecal opioid medications for nonmalignant pain have been shown to be justified in select patient populations.2 Spine disorders such as postlaminectomy syndrome, compression fractures, and spinal stenosis as well as nonspine-related pain disorders like CRPS and rheumatoid arthritis are now being managed with intrathecal therapy.1 The intrathecal route provides benefits such as using lower doses of analgesics to improve pain control, which limits the side effect burden associated with higher doses of systemic analgesics.3 However, significant complications can occur with the implantation and management of such devices. Spinal cord and nerve injury, cerebrospinal fluid (CSF) leaks, granuloma formation, and systemic and local infections are serious complications that can occur with implantation of the pumps and catheter systems. Catheters can also fracture, kink, and migrate resulting in immediate discontinuation of analgesia and precipitation of withdrawal.3 These complications are detrimental to patient care and therefore it is imperative for clinicians to understand the possible risks associated with intrathecal pump use, management, and removal.

Written Health Insurance Portability and Accountability Act (HIPAA) authorization has been obtained from the patient for the publication of this case report.

CASE REPORT

This patient presented as a data entry clerk suffering from neck and bilateral arm pain with paresthesias, hyperalgesia, allodynia, and swelling. She progressively struggled to perform her daily activities at work and home. Her care consisted of a multimodal treatment plan which included a prior anterior cervical discectomy and fusion, physical therapy, cervical epidural steroid injections, spinal cord stimulator, stellate ganglion blocks, and oral medications. Therefore, discussion was had about using an intrathecal pain pump to improve her quality of life.

After a successful trial, an intrathecal Flowonix pump was placed in the patient’s right gluteal region. The catheter tip was inserted to the upper thoracic levels, as it was difficult to navigate more superiorly due to a prior cervical fusion. Three years after implantation the Flowonix pump malfunctioned, requiring replacement with a new Medtronic pump and catheter. At this time, the nonfunctional catheter was tied off within the gluteal pocket and left in place at the T8 level to avoid a dural tear and possible spinal cord injury.

Two years after placement of the Medtronic intrathecal pump, the patient had significant weight loss post-sleeve gastrectomy. After her weight loss, the pump became loose in the pocket causing discomfort and fullness. It was believed that the weight loss contributed to the laxity of the skin and instability of the pump within the gluteal pocket. The presence of a seroma was suspected and a capsulectomy along with removal of the intrathecal pump was performed. The pump was placed in the abdomen for improved patient comfort using an extension and tunneling device. An abdominal binder was used postoperatively to prevent fluid reaccumulation in the old pocket.

On day 12 after pump revision, 675 cc of serosanguineous fluid was drained from the gluteal pocket (Figure 1). There were no signs of infection noted and cultures were negative. A computerized tomography (CT) scan of the abdomen showed an 11.7 cm × 8.3 cm × 11.3 cm fluid collection in the right gluteal region in the area of the previous pump as well as a 7 cm × 3.8 cm fluid collection adjacent to the pain pump in the subcutaneous right abdomen (Figure 2). Radiologists suspected early appendicitis due to a prominent appendix with wall enhancement. However, the fluid collection in the right lower abdomen seemed to be connected by the tract formed with the tunneling device from the gluteal region. Since fluid continued to reaccumulate despite drainage and compression, a Jackson-Pratt (JP) drain was placed. The patient did not exhibit signs of withdrawal or overdose during this time and the expected amount of medication was found in the pump.

Figure 1.:

Fluid accumulation noted in the area of the posterior pocket (right gluteal region).

Figure 2.:

Axial CT scan abdomen demonstrating an 11.7 cm × 8.3 cm × 11.3 cm fluid collection in the right gluteal region (area of the previous pump) as well as a 7 cm × 3.8 cm fluid collection adjacent to the pain pump in the subcutaneous right abdomen. CT indicates computerized tomography.

Eighteen days after the pump revision, she presented to the emergency department with a severe postural headache. This raised concerns about a possible CSF leak. The JP drain was taken off suction and she was given Butalbital/Acetaminophen/Caffeine and intravenous fluids. Confirmation of a CSF leak was established by testing the JP drain fluid for beta-2 transferrin. Surgical exploration further confirmed CSF was leaking through a hole in the nonfunctional catheter. The catheter had previously been tied off using a suture, which had eroded through the catheter, and the CSF leak was found proximal to the suture. The nonfunctional catheter was removed and the intrathecal pump and functional catheter were left in place. The fluid accumulation resolved within 24 hours of catheter removal. The patient was discharged home in stable condition without interruption of intrathecal therapy.

DISCUSSION

Intrathecal therapy is an invasive yet effective treatment that was chosen for this patient due to prolonged drug therapy-resistant pain. The premise of this treatment modality is that effective treatment can be achieved by administering a low dose of medication near the site of action, thus reducing the incidence and severity of adverse effects.4 Intrathecal pumps are a valuable tool for pain management physicians and their patients with intractable pain. However, they also carry risks for complications that should be considered before implementing treatment.

In our patient, the initial swelling in the device pocket was differentiated from a seroma, hematoma, or abscess by examination of the fluid. Aspiration of the pocket was performed, revealing 100 mL of serous-appearing fluid. The accumulation was thought to be temporally related to the patient’s weight loss, which supported our assumption it was a serous fluid collection. We hypothesized the weight loss caused increased potential space within the pocket; friction between the pump, pocket, and abdominal wall resulted in an inflammatory effusion.

Despite widely available literature discussing complications associated with intrathecal pump placement, accounts of complications after the removal of chronically placed catheters are insufficient. Frizon et al5 described the removal of intrathecal pumps in 59 patients; on 8 occasions, patients developed complications after catheter removal, including the retained catheter being the issue in half of these instances. Persistent CSF leaks were the next most common issue.

Moreover, there are no guidelines dictating the preferred method and in which cases a nonfunctional intrathecal catheter should be removed.5 This has led to variation in clinical practice. However, most clinicians leave the nonfunctional catheter in place, as extraction from the intrathecal space may result in various complications such as fistula formation, CSF leak, infection, epidural hematoma, or spinal cord damage. This can present clinically as a postural headache, pseudomeningocele, or incisional drainage necessitating additional intervention or reoperation.5 CSF leaks can be caused by persistent dural opening at the catheter insertion site, catheter–pump disconnection, a damaged catheter–pump connector, a perforated or sheared catheter, or an interruption of the catheter–catheter connector.4 Additionally, scar tissue adheres to the catheter and its anchors causing further difficulty with removal.

In this patient’s case, it was decided not to remove the catheter initially due to these aforementioned risks and complications. However, the patient developed a persistent CSF leak through a hole created by a suture eroding through the catheter. Once identified as the source of the CSF leak, total removal of the nonfunctional catheter was performed during exploratory surgery without any complications. This highlights a need for further discussion regarding the advantages and disadvantages of removing a nonfunctional catheter versus leaving it in place. Subsequent removal of the nonfunctional catheter at the time of replacement or removal of the pump could prevent further complications and corrective procedures.

As mentioned previously, the nonfunctional catheter was tied off with a suture in this patient. Alternatively, the catheter could have been made into a knot by folding the catheter over itself. Another option would be using a device to seal the distal end of the catheter. These techniques have not been formally tested or compared for efficacy or deleterious effects. Thus, there are no guidelines to follow when choosing how to handle a nonfunctional intrathecal catheter. A study comparing and contrasting these techniques and the related outcomes would benefit practitioners who utilize intrathecal pumps.

Of note, the International Neuromodulation Society founded a group of experts to create a Polyanalgesic Consensus Conference to determine evidence levels and degrees of recommendations for intrathecal therapy. Despite collaborating in 2016 to update current recommendations, there remain no guidelines or practice advisories addressing the management of nonfunctional catheters.6

This case report is of interest to physicians who implant and manage intrathecal pumps. Thorough understanding of these complications will allow them to advise their patients appropriately on the risks and bring awareness to preventable complications. This case reflects the need for a retrospective study to reevaluate the current prevailing practice in regards to intrathecal catheter and pump management due to the current gap in the literature and lack of guidelines surrounding the removal of chronically placed catheters.

DISCLOSURES

Name: Lauren B. Offield, BS.

Contribution: This author helped perform a literature review and compile the information into this case report.

Name: Vania E. Fernandez, MD.

Contribution: This author was the patient’s physician and therefore helped provide first-hand accounts of the case.

This manuscript was handled by: Mark C. Phillips, MD.

REFERENCES 1. Wilkes D. Programmable intrathecal pumps for the management of chronic pain: recommendations for improved efficiency. J Pain Res. 2014;7:571–577. 2. Kumar K, Kelly M, Pirlot T. Continuous intrathecal morphine treatment for chronic pain of nonmalignant etiology: long-term benefits and efficacy. Surg Neurol. 2001;55:79–86. 3. Staats PS. Complications of intrathecal therapy. Pain Med. 2008;9(suppl_1):S102–S107. 4. Delhaas EM, Huygen FJPM. Complications associated with intrathecal drug delivery systems. BJA Educ. 2020;20:51–57. 5. Leonardo A, Frizon MD, Navin C, Sabharwal BS, Tanmoy M, et al. Removal of intrathecal catheters used in drug delivery systems. Neuromodulation. 2018;21:665–668. 6. Deer TR, Pope JE, Hayek SM, et al. The polyanalgesic consensus conference (PACC): recommendations for intrathecal drug delivery: guidance for improving safety and mitigating risks. Neuromodulation. 2017;20:155–176.