Preliminary evaluation of an indwelling epidural catheter for repeat methylprednisolone administration in canine lumbosacral stenosis

Abstract

Objective: To determine the complications, outcomes, and patency of a permanent epidural catheter and subcutaneous access port system (ECAPS) as part of conservative management of degenerative lumbosacral stenosis in dogs.

Animals and procedure: Medical records of 11 client-owned dogs that underwent an ECAPS insertion were evaluated retrospectively. Clinical signs, complications related to the procedure, and system patency are reported.

Results: All dogs had lumbosacral pain at their initial neurological assessment, with comfort levels adequately controlled following epidural infiltrations. None suffered from complications related to the ECAPS procedure. In 10 dogs, there were no malfunctions for the duration of the study. However, in 1 dog, there was a suspected leak at Day 814. The longest duration of patency reported in this study was 870 d (at the time of writing).

Conclusion: Placement of an ECAPS is a feasible technique and a viable option to permit repeated epidural injections of steroids in dogs with degenerative lumbosacral stenosis that is managed conservatively. Further studies are required to evaluate complication rates.

Figure 1

A — At left, the epidural catheter kit components: loss-of-resistance syringe, Tuohy needle, fenestrated drape, and epidural catheter with guidewire. At right, the MILA Epidural Pain Management Kit package (MILA International, Florence, Kentucky, USA). B — Le Petite CompanionPort subcutaneous vascular access port and rounded-tip silicone catheter (Norfolk Vet Products, Skokie, Illinois, USA). The cylindrical silicone piece (arrow) was used for connecting (see Figure 3 B). C — The Huber needle included in Le Petite CompanionPort kit. This is a specially designed, non-coring needle for penetration of the port septum.

Figure 2

A — Sagittal computed tomographic (CT) image of the lumbosacral area during epidural catheter placement in a dog. Note the correct position of the Tuohy needle at the level of L7-S1. The red star represents the L7-S1 protruded disc. Sclerotic endplates (blue arrow) and spondylosis (yellow arrow) are present. B — Sagittal CT image of the lumbosacral area, showing the epidural catheter (blue arrow) exiting from the tip of the needle (red arrow) being advanced cranially in the epidural space.

Figure 3

A — Connection of the 2 components of the system (epidural and silicone catheters). The setup in this figure is used as an example and was not used during the procedure. B — Connection of 2 catheters, showing their overlap (in this picture, the overlap is only halfway). The black arrow indicates the tip of the epidural catheter, and the red arrow indicates where advancement of the epidural catheter should finish, resulting in ~2 cm of overlap in order to avoid disconnection. An additional, cylindrical silicone piece (blue arrow) is positioned to cover the overlap and enhance protection. C — The epidural catheter is shown in place with the connection to the silicone catheter and port.

Figure 4

Computed tomographic (CT) images acquired during the placement of an indwelling epidural catheter in a dog. A — Sagittal CT image of the lumbosacral area before contrast administration. Note the hyperattenuating material (blue arrows) in the epidural space, representing the epidural catheter. The dorsal hyperattenuating material (yellow arrows) is Backhaus forceps used to hold the epidural catheter. B — Left: Transverse CT image of the lumbosacral area, showing hyperattenuating material (white dot identified by the blue arrow) in the epidural space. This represents the epidural catheter following contrast injection and illustrates the relatively small size of the catheter. Right: Sagittal section showing the level at which the transverse section was taken (L7 vertebral body, green vertical line). C — Sagittal CT image of the lumbosacral area following contrast administration, showing hyperattenuating material in the epidural space representing the epidural catheter (blue arrows) and the port (yellow arrow) in the subcutaneous space.

Figure 5

A — Sagittal computed tomographic image of the lumbosacral area in a dog, with soft tissue reconstruction representing the subcutaneous injection port connected to the epidural catheter (white arrows) inserted at L7-S1. This image illustrates that the subcutaneous port (blue arrow) is quite easy to feel/identify under the skin when inserting the Huber needle (yellow arrow). B — Computed tomographic imaging with 3-dimensional reconstruction, showing the lumbosacral spine after the epidural catheter and port system implantation, in a dorsal view. C — Computed tomographic imaging with 3-dimensional reconstruction, showing the lumbosacral spine after the epidural catheter and port system implantation, in a sagittal view.