Plain radiography in patients treated with intrathecal drug delivery using an implantable pump device

Abstract

Objectives: Intrathecal drug administration using an implanted pump system is well established in intractable spasticity and pain. However, despite continuous advancements in manufacturing technology, adverse events related to the pump and catheter still occur. Most of them, such as migration, damage, disconnection and occlusion, are related to the spinal catheter. The aim of this overview is to update radiologists on how plain radiography of the implanted delivery system for intrathecal drug administration should be interpreted and to increase awareness for the need of urgent and timely multidisciplinary troubleshooting.

Methods: Plain radiographic images of patients treated with intrathecal drug administration using an implantable drug delivery system were analysed in a multidisciplinary setting at our (university) referral centre for complications in intrathecal drug administration.

Results: Examples of catheter-related adverse events are described and a proposal is made for stepwise interpretation of standard plain radiographic images.

Conclusions: Plain radiological images are the mainstay for the diagnosis of catheter-related adverse events in intrathecal drug delivery. Radiologists play an important role in an early diagnosis. An awareness of abnormal radiological findings seems important to avoid a life-threatening withdrawal syndrome.

Teaching points: • Untimely cessation of intrathecal drug delivery can lead to a life-threatening withdrawal syndrome. • Initially mild symptoms can lead to an exacerbation of a withdrawal syndrome. • Most intrathecal catheter-related problems are visible on plain radiography. • Common causes of catheter problems are migration, lacerations, occlusion and disconnection. • Knowledge on implanted intrathecal catheters is crucial for interpretation of plain radiography.

Keywords: Adverse events; Diagnostic imaging; Implantable infusion pumps; Radiography; Spinal infusions.

Fig. 1

Implanted, programmable pump system. External view (a) and drawing of implanted pump and intrathecal catheter 8731SC (b). Pump with the catheter access port (black arrowhead), pump catheter connection (thick black arrow), refill membrane (thick white arrow) and suture loops for fixation (thin grey arrow), catheter-catheter segment connection (thin white arrow) and titanium catheter end (grey arrowhead)

Fig. 2

Anterior-posterior (a) and lateral (b) plain radiography of the lumbar spine, in vivo image (d) and artist rendering (c) of the typical folded fixation anchor (with anchor symbol), large diameter catheter pump segment (black arrow), small diameter outside spinal canal (thick white arrow) and intrathecal (small white arrow, catheter end symbol) segment of the 8731SC catheter

Fig. 3

Anterior-posterior (a) and lateral (b) plain radiography of the lumbar spine, in vivo image (d) and artist rendering (c) of the typical unfolded fixation anchor of the Ascenda catheter. The small diameter catheter pump is hardly visible. The only reference points (a, b) are the needle connector (needle symbol), the unfolded anchor (anchor symbol), and the titanium catheter tip (catheter end symbol)

Fig. 4

Reel syndrome with signs of withdrawal syndrome in a 52-year-old woman with dystonia in CRPS. The apex of the pump is turned from the 11 o’clock to 2 o’clock position (white arrow). Because of the visible traction on the catheter (black arrow), the pump must be rotated several times about the horizontal axis

Fig. 5

Disconnection at the pump-catheter site (white arrow) with signs of withdrawal syndrome in a 52-year-old woman with dystonia in complex regional pain syndrome

Fig. 6

Reel syndrome with signs of withdrawal syndrome in a 45-year-old extremely obese woman with spasticity in multiple sclerosis. Baseline plain radiography (a, c, e) with follow-up images after 4 weeks (b, d, f). The apex of the pump is turned from the 11 o’clock (a) to the 2 o’clock (b) position (black-white arrow). The Ascenda needle connector is moved from the original position (a) to a more lateral position (b) (grey-white arrow) with disconnection of catheter pump segment (black arrow). The Ascenda catheter is hardly visible (white arrows). The tip of the catheter is unchanged (c–f) at level T8 (grey-black arrow)

Fig. 7

A magnification view of the black circle (a) shows the radiopaque pump identifier consisting of the logo of the manufacturer and three alphabetic letters (white arrow) with visible electronics (b) into the left-hand side (black arrow). For (some) odd rotations of the pump to the vertical axis (Twiddler’s syndrome), the pump is located on the head, which can be recognised by the logo in mirror image, and the electronics to the right-hand side (c)

Fig. 8

Twiddler’s syndrome with signs of withdrawal syndrome in a 51-year-old woman with dystonia in complex regional pain syndrome. A repeatedly twisted old type catheter is visible on lateral plain radiography behind the implanted pump (white arrow) (a), magnification of the pump with artist rendering (b) and an in vivo image (c). The catheter is fixed to the pump with an old sutured connector (grey arrow)

Fig. 9

Catheter 8731SC migration (gray arrow) caused by an open V-wing anchor (anchor symbol) in an 80-year-old woman with intractable pain and spasticity caused by failed back surgery syndrome, with a spinal cord lesion (SCL) T12 treated with intrathecal baclofen

Fig. 10

Sheared catheter 8731SC (gray arrow) with retracted segment partially outside the spinal canal, with no cerebrospinal leakage and no clinical signs of postural spinal headache or an intracranial hypotension syndrome, in a 48-year-old woman with cerebral palsy treated with intrathecal baclofen

Fig. 11

A 62-year-old man with treatment-resistant spasticity was successfully treated for many years with intrathecal baclofen. During exacerbation of the clinical symptomatology, the catheter 8731SC was found to be torn off and left behind in the spinal canal (white arrow). For further treatment, a new catheter, of the same type was inserted (gray arrow)

Fig. 12

In this pump rotor examination, a normal rotation was found (change in position indicated by the black arrows). The white arrows show the pump position identifier (Fig. 7)