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Soonchunhyang Med Sci > Volume 28(2); 2022 > Article
Chung, Park, Kim, and Kim: Epidural Granuloma after Intrathecal Pump Implantation in the Spinal Cord: A Case Report


Intrathecal pump (ITP) is a procedure performed for pain control in patients with cancer pain and refractory pain. Complications such as catheter-related infection, granuloma, and migration may occur, so continuous management is required. In this case, ITP insertion was performed due to central cord syndrome that occurred after a traffic accident. T-L spine computed tomography was performed due to persistent pain exacerbation 22 months after insertion, and epidural granuloma was confirmed. After that, granuloma removal and ITP revision surgery were performed, and pain control has been good so far. The purpose of this case was to investigate the risk factors and evaluation methods for catheter-related granuloma.


Since the 1990s, intrathecal pump (ITP) has been commonly inserted, especially for the control of intractable chronic pain, such as persistent pain, complex regional pain syndrome, central pain, peripheral and central neuropathic pain, and failed spinal cord syndrome [1,2]. Intrathecal therapy is an effective method for reducing drug-related systemic side effects, such as overdose, addiction, and sedation. Since the year 2000, there has been greater awareness of catheter-related complications, such as meningitis, infection, device migration, and epidural granuloma may occur [3].
Here, we present a patient with central cord syndrome after a traffic accident who developed a catheter tip granuloma (CG) after the insertion of ITP that migrated to the epidural space. The CG was removed following radiographic confirmation using T-L spine computed tomography (CT).
All procedures were performed after the informed consent of the patient, and informed consent was also given for publication in this case.


A 55-year-old man, with no specific medical history, experienced neck and arm pain due to a motorcycle traffic accident. Central cord syndrome was diagnosed on magnetic resonance imaging (MRI). The patient was treated via anterior interbody fusion as well as cervical and cage insertion. Additionally, an MRI of the right knee was performed due to sustained knee pain 6 months after surgery. The patient underwent a meniscectomy for the management of a medial meniscal posterior tear. Despite surgery, systemic pain and edema of the left-sided foot and ankle persisted. Medications were prescribed and a neuraxial block was also performed. An ITP (SynchroMed; Medtronic, Minneapolis, MN, USA) was inserted to aid with persistent pain control.
Three tests were conducted, all of which reduced pain without any side effects. The catheter was inserted into the L1–2 interlaminar space without any specific side effects, and the catheter tip entered the T10 level (Fig. 1). Six milligrams of morphine per day were delivered via the ITP. After the procedure, the patient’s pain was controlled to mild pain (Visual Analog Scale [VAS] score=2–3).
Approximately 4.3 months after the ITP was inserted, the patient reported constipation and recurrent flank pain, and an abdominal CT was performed. A Meckel’s diverticulum was identified. After 14 days of hospitalization and antibiotics, the patient was discharged. Subsequently, the patient was readmitted for a segmental resection of the small bowel because of recurrent intestinal obstruction.
At 22 months after the ITP insertion, the patient exhibited weakness (the grading of muscle power=4) and numbness in both lower legs. As time passed, walking became difficult, and the pain on the left side was perpetual (VAS score=8–9). The pump injection dose was increased by 10% every 3 weeks to 7.7 mg of morphine, but the pain remained uncontrolled. To exclude the possibility of pump catheter migration and CG, a T-L spine CT was performed. A granuloma was identified with contrast media. The CG developed in the 4.7 cm extradural layer and cord compression was suspected (Fig. 2). The CG was removed and the ITP was reinserted (Fig. 3). After the procedure, the patient’s pain and left leg and lower back pain decreased (VAS score=3), and motor weakness returned to a normal level.
The patient is being followed up in the outpatient. The patient is undergoing follow-up through an outpatient clinic, and the pain is relatively well controlled up to now.


ITP is an effective method to control pain in patients with refractory pain, but continuous observation is necessary because catheter-related complications may occur.
After inserting an ITP for pain management due to central cord syndrome, a CG formed and migrated to the epidural space, which was confirmed by CT of the T-L spine region (Fig. 2). The CG was also confirmed in the abdominal CT performed to diagnose Meckel’s diverticulum (Fig. 4).
ITP is a method of delivering drugs directly to the receptors in the intrathecal space. It has the advantage of reducing side effects, including addiction and oversedation, that can occur due to the prolonged use of opioid medication.
CG is an inflammatory mass caused by the activation of macrophages and eosinophils. The risk of intrathecal CG increases when high concentrations of morphine or hydromorphone are used [4]. Intrathecal delivery of high-dose morphine, combined with clonidine, and baclofen are known risk factors for CG. One study suggested that CG formation is increased when a high concentration of morphine (>30 mg/mL) is used. A few reports have also reported CG formation when a combination of morphine and clonidine is administered intrathecally. Intrathecal baclofen and the risk of CG has also been reported but the results varied among the studies [5]. Overall, evidence is still lacking and large-scale studies are needed in the future.
CG formation may not be related to the duration of the indwelling ITP. CG can occur within 5 weeks of intrathecal insertion or after more than 6 years. CG may also not be related to the drug choice or the concentration. In our patient, the morphine was diluted to 10 mg/mL and injected at 5–7 mg/day. Moreover, CG formation was confirmed on abdominal CT at 4.3 months after insertion of the ITP, and there was no correlation with the duration.
CG formation has been associated with cerebrospinal fluid flow velocity. According to a previous study, the location of the catheter tip on the middle thoracic spine had a high CG incidence, and there was no report on the location of the catheter tip on the cervical, lumbar spine. Therefore, the location of the catheter tip is recommended to be lower thoracic or thoraco-lumbar spine [5]. Previous spinal surgery may cause chronic inflammatory diseases in the nervous system, including the epidural space. This may be a risk factor for CG. Furthermore, deformation of the spinal anatomy due to surgery and changes in the cerebrospinal fluid dynamics may also have an effect. Interestingly, a relationship between smoking and an increased risk of invasive catheter use has also been reported [5]. Further studies to clarify the risks of CG development following ITP insertion are warranted.
For our patient, changes in the cerebrospinal fluid dynamics due to previous neck surgery and chronic inflammatory disease caused by diverticulitis may have affected the CG formation. In patients with the above risk factors, if there is no response to dose increase and bolus injection, imaging evaluation for rapid detection of problems is important. It shows the recently introduced ITP management guidelines (Fig. 5) [6].
Catheter-related complications, such as kinking and breakage, have been reported in up to 7.4% [7]. The incidence of intrathecal catheter migration during intrathecal baclofen is high, and the cause is thought to be related to the patient’s underlying disease. In patients with severe spasticity, the position of the catheter may gradually change during spastic ambulation, leading to catheter migration. The risk of kinking or breakage can be reduced by shortening the length of the catheter.
In this case, a CT scan was performed to determine if a CG is present. However, MRI may be more effective for determining the exact causes. The radiofrequency generated in the magnetic resonance environment can cause serious danger by generating heat around the pump, as well as increasing the risk of the implanted device migrating or being damaged during imaging. A recent study reported that MRI was successfully performed by emptying the drug in the ITP before the MRI and restricting the patient’s movement, and no adverse effects occurred [8,9].
ITP is a good option for the control of chronic and uncontrolled pain, including cancer pain. However, various side effects are possible, and active management is required even after the ITP has been inserted.
In conclusions, such as morphine or hydrophone sufentanil, the dose or concentration should be lowered (<30 mg/mL). To reduce catheter-related complications, the catheter tip is placed at the lower thoracic level, and the catheter length can be shortened to reduce the risk of kinking or breakage.
Patient’s symptoms should be checked frequently to prevent sudden increases in pain or other neurological symptoms. It is important to detect the occurrence of complications such as migration, CG and infection early through active imaging tests such as CT and MRI.


No potential conflict of interest relevant to this article was reported.

Fig. 1
Intrathecal pump implantation. A catheter was inserted under the fluoroscopy guide in the L1/2 interlaminar space, and the catheter tip was advanced up to T10 level.
Fig. 2
(A) An epidural granuloma identified in the T-L spine computed tomography. (B) In the axial view, an epidural granuloma of 4.7 cm was identified at the T10–11 level.
Fig. 3
(A–D) The intrathecal pump revision and epidural granuloma removal. The catheter tip was confirmed to be in the epidural space, and this is a photograph of the removed granuloma.
Fig. 4
An epidural granuloma identified in the abdominal computed tomography at 4.3 months after insertion of the intrathecal pump. An epidural granuloma of about 1.8 cm was confirmed on the axial view.
Fig. 5
Intrathecal pump management algorithm. The dashed line indicates the management for cases of no treatment response.


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