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Tangled catheter as a rare cause of baclofen pump malfunction
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Surgical Neurology 72 (2009) 80 – 82 www.surgicalneurology-online.com
Technique
Tangled catheter as a rare cause of baclofen pump malfunction Toru Fukuhara, MD⁎, Tomotaka Tanaka, MD, Yoichiro Namba, MD, Hideyuki Kuyama, MD Division of Neurosurgery, Neuro-research Institute for Stroke Care, National Hospital Organization Okayama Medical Center, Okayama, 701-1192, Japan Received 11 December 2007; accepted 7 January 2008
Abstract
Background: Several catheter problems have been reported as causes of baclofen pump malfunction; however, a tangled catheter has never been described. Case Description: A 52-year-old woman with bilateral leg spasticity because of spinal multiple sclerosis underwent baclofen pump implantation, which was subcutaneously placed in the right upper quadrant. She visited for a pump refill 3 months postimplantation with reworsening of her leg spasticity. It was noted that there was more baclofen remaining in the pump than programmed. Abdominal x-ray indicated the kink of the catheter around the pump, and the catheter was explored under local anesthesia. Upon exposure, the catheter was found to be tangled. After the revision of this tangled catheter, the patient's spasticity improved again. Conclusions: Although the exact mechanism of this complication is unknown, the frictioncompression of the catheter against the iliac bone may be the cause. Implanting the pump away from the bony formation may avoid catheter entanglement. © 2009 Elsevier Inc. All rights reserved.
Keywords:
Baclofen pump; Malfunction; Tangled catheter
1. Introduction Although the effectiveness of intrathecal baclofen administration against spasticity has been well recognized, the use of delivery systems, the pump, and the catheter is known to be associated with a high complication rate [1,4,5]. The most vulnerable part is reported to be the catheter, and the reported problems are dislodgement, kinking, tearing, and disconnection [4]. We have encountered a unique catheter problem, a tangled catheter, which may be the progression of kinking. The details of this case are described, and the considerable mechanisms are discussed to avoid this rare complication. 2. Case report A 52-year-old woman with a 9-year history of spinal multiple sclerosis was considered for implantation of an intrathecal baclofen pump because of bilateral leg spasticity ⁎ Corresponding author. Tel.: +81 86 294 9911; fax: +81 86 294 9255. E-mail address: [email protected] (T. Fukuhara). 0090-3019/$ – see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.surneu.2008.01.043
resulting from her thoracic cord lesions. She was able to move from bed to wheel chair and keep standing with a cane but could not walk. She had clonus reflex on bilateral ankles. After a positive screening test with bolus 50 μg of baclofen administration through lumbar tap, she opted for pump implantation, and a SyncroMed 8627L-18 pump (Medtronic, Minneapolis, Minn) was subcutaneously placed in the right upper quadrant, and a 2-piece 8711 catheter was inserted to the Th12 level. Excess catheter is coiled and placed deep to the pump. The pump was anchored in the subcutaneous pocket with 4-point silk sutures. Her postoperative course was unremarkable, except for the difficulty in determining the maintenance dose because her leg spasticity was very sensitive to changes in baclofen doses. She needed some spasticity for standing up, and her maintenance dose was determined to be 25 μg/d during the hospitalization. Her daily activities were preserved with this dose, and her clonus reflex disappeared at discharge. She visited for a pump refill 3 months postimplantation and then she complained that the leg spasticity returned. Her leg spasticity worsened to the preoperative level with the reappearance of clonus reflex. We noted that there was more baclofen remaining in the pump
T. Fukuhara et al. / Surgical Neurology 72 (2009) 80–82
Fig. 1. Abdominal anteroposterior plain x-ray film taken before the exploration surgery, suggesting some kinking of the catheter around the pump nozzle (white arrow) and twisting around the iliac bone (black arrow).
81
has been recognized as one of causative factors for malfunctions. However, 2-piece 8711 catheter, which is the only commercially available catheter in Japan, has been considered a better one regarding the malfunction [2], and other possible cause should be considered. This patient was movable, and she felt the pump touching her iliac bone when she moved. The friction-compression against the iliac bone may be the cause of malfunction [3], and this force may have generated the twisting of the catheter. We tried to implant the pump away from the iliac bone; however, when she twisted herself when moving from bed to wheelchair, the lower part of the pump seemed to push the iliac crest. The initial twist may have occured with this force. Because her symptoms at pump malfunction were not so severe and were tolerable, she did not complain about her spasticity reworsening until the scheduled visit. The twist or kinking progressed to tangling during approximately a one month. It is still unclear why this occurred on her because her condition is not so special as patients who undergo this
than programmed. It was calculated that baclofen remaining in the pump was compatible with approximately a 30-day amount, so it was suspected that this problem occurred at least 1 month ago. There were no signs of infection, and the patient did not report any tenderness around the pump; however, she had occasionally felt her pump touching her iliac bone when she moved. She was admitted for an inspection of the system. Abdominal x-ray indicated that the catheter around the pump seemed to have formed a kink (Fig. 1), although the position of the pump did not change. No cerebrospinal fluid returned from the access port. To identify the obstructed portion, we explored the catheter in the abdominal subcutaneous pocket under local anesthesia. Abdominal skin was incised at the same portion, and upon exposure, the catheter was found to be tied; even after being untied, it remained twisted (Fig. 2). To regain the original alignment, it was necessary to cut and reconnect the catheter. After the operation, the patient's spasticity gradually improved, and she was discharged in a week. No further problems occurred at the following pump refill 3 months after this revision. 3. Discussion Catheter problems have been reported to be the major cause of baclofen pump malfunction [1,4,5]; however, to our knowledge, a tangled catheter has never been described in the literature. This malfunction can be regarded as a progression of kinking, and among the previously described malfunctions, it is presumed that similar twisted catheter may occur after frequent rotations of the pump [5]. The uniqueness of our case is that the pump did not flip or move after the implantation, and the catheter itself became twisted. There is the possibility that the mechanical properties of the catheter may affect the occurrence of this trouble because the type of the catheter (model 8703 vs model 8704)
Fig. 2. Photographs obtained during the exploration surgery of the catheter around the pump. The catheter was tangled (A) and remained twisted even after being untied (B). Because the catheter could not be untwisted (C), it was necessary to cut the catheter, return it to its proper alignment, and then reconnect it (D).
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T. Fukuhara et al. / Surgical Neurology 72 (2009) 80–82
surgery. So many patients with implanted baclofen pump are movable more than she. Furthermore, although surgeons usually try to implant the pump away from bony formation, we believe in a lot of cases, including small children, the pumps cannot be away enough from the iliac bone. Other factors could have initiate this twisting, including catheter mechanical properties, the way of initial operative procedures, and the style of her daily activity. Because the exact mechanism of this complication is unknown, what we can do for avoiding this catheter entanglement so far is implanting the pump away from the bony formation. Acknowledgments The authors thank Okayama Neuromedical Research Association at National Hospital Organization Okayama Medical Center (Okayama, Japan) for the editorial assistance. References [1] Albright AL, Gilmartin R, Swift D, et al. Long-term intrathecal baclofen therapy for severe spasticity of cerebral origin. J Neurosurg 2003;98: 291-5. [2] Dawes WJ, Drake JM, Fehlings D. Microfracture of a baclofen pump catheter with intermittent under- and overdose. Pediatr Neurosurg 2003; 39:144-8. [3] Dickerman RD, Stevens QE, Schneider SJ. The role of surgical placement and pump orientation in intrathecal pump system failure: a technical report. Pediatr Neurosurg 2003;38:107-9. [4] Penn RD, York MM, Paice JA. Catheter systems for intrathecal delivery. J Neurosurg 1995;83:215-7. [5] Vender JR, Hester S, Waller JL, et al. Identification and management of intrathecal baclofen pump complications: a comparison of pediatric and adult patients. J Neurosurg 2006;104(1 Suppl Pediatrics):9–15.
Commentary The authors of this report present an unusual complication of a system for intrathecal drug delivery—a major tangling of the catheter that resulted in obstruction of flow. This complication, although quite unusual, is not unheard of. Most experienced implanters, including myself, encounter
this problem in their practice; it is commonly seen in patients whose pump flips or rotates inside its pocket. The unusual feature of this particular patient was that the pump apparently did not move, and therefore, it remains unclear how the catheter could turn so many times as to result in complete obstruction of its lumen. Interestingly enough, I tested one catheter many years ago for obstruction because tangling—one of my patients had its pump flipped during each refill procedure, and I was concerned that as I rotated this pump, it would eventually result in catheter obstruction. In my hands, the standard intrathecal catheter that we were implanting those days remained patent even after 100 twists. This unscientific testing was, obviously, never published, but I remain convinced that catheters will survive through the pump lifetime considering that with one turn every 2 months for 5 years, there will be only 30 turns. In the authors' case, judging by the photo, there were less than 30 turns of the catheter, but these twists were limited to a short segment of the catheter and there was more than one angle of twisting, it is conceivable that the catheter became actually knotted and, as a result, obstructed. The article shows 2 important points. First of all, it underscores virtually any potential complication does indeed happen, and one has to be prepared to fix it. Secondly, it indicates that a simple troubleshooting algorithm allows one to figure out most problems; in this case, loss of effectiveness and higher than expected residual volume do point in the direction of catheter obstruction, which, in turn, prompts radiographic testing and side-port aspiration, and eventually, surgical exploration and resolution of the encountered problem. I do agree with the authors that this is a first welldocumented case of catheter obstruction because of tangling, and I would encourage others to report their usual and unusual complications to educate ourselves and our patients and to be prepared for all surprises that one may expect from this treatment modality. Konstantin V. Slavin, MD Department of Neurosurgery University of Illinois at Chicago Chicago, IL 60612, USA
Surgical Neurology 72 (2009) 80 – 82 www.surgicalneurology-online.com
Technique
Tangled catheter as a rare cause of baclofen pump malfunction Toru Fukuhara, MD⁎, Tomotaka Tanaka, MD, Yoichiro Namba, MD, Hideyuki Kuyama, MD Division of Neurosurgery, Neuro-research Institute for Stroke Care, National Hospital Organization Okayama Medical Center, Okayama, 701-1192, Japan Received 11 December 2007; accepted 7 January 2008
Abstract
Background: Several catheter problems have been reported as causes of baclofen pump malfunction; however, a tangled catheter has never been described. Case Description: A 52-year-old woman with bilateral leg spasticity because of spinal multiple sclerosis underwent baclofen pump implantation, which was subcutaneously placed in the right upper quadrant. She visited for a pump refill 3 months postimplantation with reworsening of her leg spasticity. It was noted that there was more baclofen remaining in the pump than programmed. Abdominal x-ray indicated the kink of the catheter around the pump, and the catheter was explored under local anesthesia. Upon exposure, the catheter was found to be tangled. After the revision of this tangled catheter, the patient's spasticity improved again. Conclusions: Although the exact mechanism of this complication is unknown, the frictioncompression of the catheter against the iliac bone may be the cause. Implanting the pump away from the bony formation may avoid catheter entanglement. © 2009 Elsevier Inc. All rights reserved.
Keywords:
Baclofen pump; Malfunction; Tangled catheter
1. Introduction Although the effectiveness of intrathecal baclofen administration against spasticity has been well recognized, the use of delivery systems, the pump, and the catheter is known to be associated with a high complication rate [1,4,5]. The most vulnerable part is reported to be the catheter, and the reported problems are dislodgement, kinking, tearing, and disconnection [4]. We have encountered a unique catheter problem, a tangled catheter, which may be the progression of kinking. The details of this case are described, and the considerable mechanisms are discussed to avoid this rare complication. 2. Case report A 52-year-old woman with a 9-year history of spinal multiple sclerosis was considered for implantation of an intrathecal baclofen pump because of bilateral leg spasticity ⁎ Corresponding author. Tel.: +81 86 294 9911; fax: +81 86 294 9255. E-mail address: [email protected] (T. Fukuhara). 0090-3019/$ – see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.surneu.2008.01.043
resulting from her thoracic cord lesions. She was able to move from bed to wheel chair and keep standing with a cane but could not walk. She had clonus reflex on bilateral ankles. After a positive screening test with bolus 50 μg of baclofen administration through lumbar tap, she opted for pump implantation, and a SyncroMed 8627L-18 pump (Medtronic, Minneapolis, Minn) was subcutaneously placed in the right upper quadrant, and a 2-piece 8711 catheter was inserted to the Th12 level. Excess catheter is coiled and placed deep to the pump. The pump was anchored in the subcutaneous pocket with 4-point silk sutures. Her postoperative course was unremarkable, except for the difficulty in determining the maintenance dose because her leg spasticity was very sensitive to changes in baclofen doses. She needed some spasticity for standing up, and her maintenance dose was determined to be 25 μg/d during the hospitalization. Her daily activities were preserved with this dose, and her clonus reflex disappeared at discharge. She visited for a pump refill 3 months postimplantation and then she complained that the leg spasticity returned. Her leg spasticity worsened to the preoperative level with the reappearance of clonus reflex. We noted that there was more baclofen remaining in the pump
T. Fukuhara et al. / Surgical Neurology 72 (2009) 80–82
Fig. 1. Abdominal anteroposterior plain x-ray film taken before the exploration surgery, suggesting some kinking of the catheter around the pump nozzle (white arrow) and twisting around the iliac bone (black arrow).
81
has been recognized as one of causative factors for malfunctions. However, 2-piece 8711 catheter, which is the only commercially available catheter in Japan, has been considered a better one regarding the malfunction [2], and other possible cause should be considered. This patient was movable, and she felt the pump touching her iliac bone when she moved. The friction-compression against the iliac bone may be the cause of malfunction [3], and this force may have generated the twisting of the catheter. We tried to implant the pump away from the iliac bone; however, when she twisted herself when moving from bed to wheelchair, the lower part of the pump seemed to push the iliac crest. The initial twist may have occured with this force. Because her symptoms at pump malfunction were not so severe and were tolerable, she did not complain about her spasticity reworsening until the scheduled visit. The twist or kinking progressed to tangling during approximately a one month. It is still unclear why this occurred on her because her condition is not so special as patients who undergo this
than programmed. It was calculated that baclofen remaining in the pump was compatible with approximately a 30-day amount, so it was suspected that this problem occurred at least 1 month ago. There were no signs of infection, and the patient did not report any tenderness around the pump; however, she had occasionally felt her pump touching her iliac bone when she moved. She was admitted for an inspection of the system. Abdominal x-ray indicated that the catheter around the pump seemed to have formed a kink (Fig. 1), although the position of the pump did not change. No cerebrospinal fluid returned from the access port. To identify the obstructed portion, we explored the catheter in the abdominal subcutaneous pocket under local anesthesia. Abdominal skin was incised at the same portion, and upon exposure, the catheter was found to be tied; even after being untied, it remained twisted (Fig. 2). To regain the original alignment, it was necessary to cut and reconnect the catheter. After the operation, the patient's spasticity gradually improved, and she was discharged in a week. No further problems occurred at the following pump refill 3 months after this revision. 3. Discussion Catheter problems have been reported to be the major cause of baclofen pump malfunction [1,4,5]; however, to our knowledge, a tangled catheter has never been described in the literature. This malfunction can be regarded as a progression of kinking, and among the previously described malfunctions, it is presumed that similar twisted catheter may occur after frequent rotations of the pump [5]. The uniqueness of our case is that the pump did not flip or move after the implantation, and the catheter itself became twisted. There is the possibility that the mechanical properties of the catheter may affect the occurrence of this trouble because the type of the catheter (model 8703 vs model 8704)
Fig. 2. Photographs obtained during the exploration surgery of the catheter around the pump. The catheter was tangled (A) and remained twisted even after being untied (B). Because the catheter could not be untwisted (C), it was necessary to cut the catheter, return it to its proper alignment, and then reconnect it (D).
82
T. Fukuhara et al. / Surgical Neurology 72 (2009) 80–82
surgery. So many patients with implanted baclofen pump are movable more than she. Furthermore, although surgeons usually try to implant the pump away from bony formation, we believe in a lot of cases, including small children, the pumps cannot be away enough from the iliac bone. Other factors could have initiate this twisting, including catheter mechanical properties, the way of initial operative procedures, and the style of her daily activity. Because the exact mechanism of this complication is unknown, what we can do for avoiding this catheter entanglement so far is implanting the pump away from the bony formation. Acknowledgments The authors thank Okayama Neuromedical Research Association at National Hospital Organization Okayama Medical Center (Okayama, Japan) for the editorial assistance. References [1] Albright AL, Gilmartin R, Swift D, et al. Long-term intrathecal baclofen therapy for severe spasticity of cerebral origin. J Neurosurg 2003;98: 291-5. [2] Dawes WJ, Drake JM, Fehlings D. Microfracture of a baclofen pump catheter with intermittent under- and overdose. Pediatr Neurosurg 2003; 39:144-8. [3] Dickerman RD, Stevens QE, Schneider SJ. The role of surgical placement and pump orientation in intrathecal pump system failure: a technical report. Pediatr Neurosurg 2003;38:107-9. [4] Penn RD, York MM, Paice JA. Catheter systems for intrathecal delivery. J Neurosurg 1995;83:215-7. [5] Vender JR, Hester S, Waller JL, et al. Identification and management of intrathecal baclofen pump complications: a comparison of pediatric and adult patients. J Neurosurg 2006;104(1 Suppl Pediatrics):9–15.
Commentary The authors of this report present an unusual complication of a system for intrathecal drug delivery—a major tangling of the catheter that resulted in obstruction of flow. This complication, although quite unusual, is not unheard of. Most experienced implanters, including myself, encounter
this problem in their practice; it is commonly seen in patients whose pump flips or rotates inside its pocket. The unusual feature of this particular patient was that the pump apparently did not move, and therefore, it remains unclear how the catheter could turn so many times as to result in complete obstruction of its lumen. Interestingly enough, I tested one catheter many years ago for obstruction because tangling—one of my patients had its pump flipped during each refill procedure, and I was concerned that as I rotated this pump, it would eventually result in catheter obstruction. In my hands, the standard intrathecal catheter that we were implanting those days remained patent even after 100 twists. This unscientific testing was, obviously, never published, but I remain convinced that catheters will survive through the pump lifetime considering that with one turn every 2 months for 5 years, there will be only 30 turns. In the authors' case, judging by the photo, there were less than 30 turns of the catheter, but these twists were limited to a short segment of the catheter and there was more than one angle of twisting, it is conceivable that the catheter became actually knotted and, as a result, obstructed. The article shows 2 important points. First of all, it underscores virtually any potential complication does indeed happen, and one has to be prepared to fix it. Secondly, it indicates that a simple troubleshooting algorithm allows one to figure out most problems; in this case, loss of effectiveness and higher than expected residual volume do point in the direction of catheter obstruction, which, in turn, prompts radiographic testing and side-port aspiration, and eventually, surgical exploration and resolution of the encountered problem. I do agree with the authors that this is a first welldocumented case of catheter obstruction because of tangling, and I would encourage others to report their usual and unusual complications to educate ourselves and our patients and to be prepared for all surprises that one may expect from this treatment modality. Konstantin V. Slavin, MD Department of Neurosurgery University of Illinois at Chicago Chicago, IL 60612, USA