- Email: [email protected]
Removal of adherent ventricular catheters by a modified sheath introducer system: Technical note
Removal of Adherent Ventricular Catheters by a Modified Sheath Introducer System: Technical Note By Marcus H.T. Reinges, Veit Rohde, Timo Krings, Uwe Spetzger, and Joachim M. Gilsbach Aachen, Germany
Background/Purpose: A series of technical notes has been dedicated to the removal of retained intracranial shunt catheters, among which the intraluminal cautery proved to be the most accepted technique. However, several reports showed that these techniques still harbor potentially serious complications. Methods: In this technique, a modified plastic sheath introducer system is passed over the retained ventricular catheter. While advancing the tube along the longitudinal axis of the catheter, circular movements of the tube around the longitudinal axis of the catheter are performed, allowing the tube to act as a spherical knife cutting the ingrown choroid plexus or ependymal adhesions. Results: There were no procedure-related complications in any of the 9 patients treated by the technique described. The
T
HE REMOVAL of obstructed ventricular catheters might be hazardous because of the risk of ventricular bleeding from ingrown choroid plexus and ependymal adhesions.1-7 To facilitate removal of retained intracranial shunt catheters, several technical notes have been published, and intraluminal cautery is the most accepted technique.3,7-10 However, several reports found that these techniques still harbor potentially serious complications.10-14 MATERIALS AND METHODS A commercially available sheath introducer system (Cordis Corporation, Miami, FL) is modified by cutting off the upper part of the system (Fig 1). Only the so-revealed plastic tube is used (Fig 1). The extracranial shunt hardware is disconnected from the ventricular catheter after having fixed the exposed distal end of the ventricular catheter by suture not to allow it to escape into the ventricular system (Fig 2). The thread is then pulled through the modified sheath introducer system, which is carefully passed over the ventricular catheter (Fig 2B). Note that the tube must fit exactly over the catheter to avoid shearing of adjacent brain tissue. While advancing the tube along the longitudinal axis of the catheter, circular movements of the tube around the longitudinal axis of the catheter are performed, allowing the tube to act as a spherical knife cutting the ingrown choroid plexus or ependymal adhesions (Fig 2C). After introducing the tube to a depth corresponding to the length of the ventricular catheter, the ventricular catheter is removed via the tube. Sometimes one has the feeling of “giving way” of the ventricular catheter when the tube has reached the ventricular catheter’s end. In case a new ventricular catheter has to be placed at the same site, it can be introduced through the same tube. The technique described was applied in 9 patients, 5 children, and 4 adults undergoing shunt revision for proximal catheter obstruction with a retained ventricular catheter. In 7 patients a retained frontal ventricular catheter, and in 2 patients a retained occipital ventricular catheter
procedure proved to be easy and effective in all cases. In addition, in case a new ventricular catheter was needed at the same site, it could be placed via the same tube.
Conclusions: The technique described seems to be an easy, safe, and effective alternative to other techniques for removal of retained ventricular catheters. However, considering the limited number of patients treated with the technique described and the great number of patients treated by the widely accepted intraluminal cautery, one cannot claim the one technique as superior to the other at this stage. J Pediatr Surg 35:1795-1798. Copyright © 2000 by W.B. Saunders Company. INDEX WORDS: Choroid plexus, hydrocephalus, intraluminal cautery, retained ventricular catheter, shunt, shunt complication, shunt revision.
was removed successfully. In 5 patients the adherent catheter was removed, and a new ventricular catheter was introduced via the same tube; in the remaining 4 patients the tube was only used for removal of the adherent catheter. The following case is a typical example. In this 6-year-old boy a pilocytic astrocytoma of the hypothalamus was partially removed, and a right frontal ventriculoperitoneal shunt was inserted at the age of 1 year. Four years later, the child presented with symptoms of increased intracranial pressure. Computed tomography (CT) examination showed small ventricles, and lumbar puncture results showed an opening pressure of 50 cm H2O. Shunt tapping confirmed proximal catheter obstruction. Thus, the indication for shunt revision was given. Intraoperatively, no cerebral spinal fluid (CSF) could be aspirated through the ventricular catheter, and the ventricular catheter was found to be adherent. Because of the proven small size ventricles it was expected to be difficult to introduce a new ventricular catheter. Therefore, the technique described above for removal of the ventricular catheter was used. After removal of the ventricular catheter without complications, a new ventricular catheter was introduced via the same tube. Finally, the tube was removed, and the new ventricular catheter was connected with the remaining shunt hardware. In the course of, and after the procedure, no signs for intraventricular hemorrhage or other complications were observed. The patient’s symptoms were relieved completely, and the postoperative CT scan showed correct placement of the new ventricular catheter.
From the Department of Neurosurgery, University of Technology (RWTH), Aachen, Germany. Address reprint requests to Marcus H.T. Reinges, MD, Department of Neurosurgery, University of Technology (RWTH), Pauwelsstr. 30, D-52057 Aachen, Germany. Copyright © 2000 by W.B. Saunders Company 0022-3468/00/3512-0023$03.00/0 doi:10.1053/jpsu.2000.19260
Journal of Pediatric Surgery, Vol 35, No 12 (December), 2000: pp 1795-1798
1795
1796
REINGES ET AL
Fig 1. (A) Below: The original sheath introducer system (Cordis Corporation, Miami, FL). Above: The revealed tube after having cut off the upper part of the original system. (B) View into the distal end of the tube.
Fig 2. Schematic drawing of the technique for removal of an adherent ventricular catheter by a modified sheath introducer system used as spherical knife. In the drawing an occipital catheter is removed; however, the technique can be used in any location of the catheter. (A) Overview. (B, C) Partial magnification of (A) with cross-section (below). After disconnection of the extracranial hardware from the ventricular catheter the exposed distal end of the ventricular catheter is sewed to avoid the catheter sliding into the ventricular system (A). The thread is pulled through the tube, which is carefully passed over the ventricular catheter (A and B). While advancing the tube, circular movements around the longitudinal axis of the catheter are performed to use the tube as a spherical knife so that choroid plexus which pervades the holes in the catheter is cut (C).
REMOVAL OF VENTRICULAR CATHETERS
1797
RESULTS
In all 9 patients shunt removal was easily possible using the technique described. Ingrowth of the choroid plexus into the ventricular catheter could be seen after catheter removal in all patients. In the 5 patients in which a new catheter was introduced through the same tube, correct placement of the catheter was achieved. There were no procedure-related complications in any of the patients. DISCUSSION
A series of technical notes has been dedicated to the removal of retained intracranial shunt catheters, among which the intraluminal cautery described by Chambi and Hendrick3 and by Whitfield et al proved to be the most accepted technique.7-10 However, these techniques— especially that of the widely accepted intraluminal cautery— harbor potentially serious complications.10-14 For example, a burn at the site of the cautery grading plate, a charring of the ventricular catheter, intraventricular hemorrhage, or a passing of the stylet’s tip through one of the catheter’s side holes has been reported using the technique of intraluminal cautery.10,12-14 Likewise, the presented technique for removal of retained ventricular catheters bears the risk of intraventricular hemorrhage. However, in none of our 9 patients was this complication seen. The reason may be that the choroid plexus that is ingrown into ventricular catheter drainage holes and ependymal adhesions are detached from the catheter immediately at the site of ingrowth or adhesion, and that there cannot be any rest of adherent tissue after the procedure. In contrast, using the technique of intraluminal cautery one cannot be sure of having detached these structures completely. Further, the risk of bleeding or tissue injury by the stylet’s tip inadvertently leaving the catheter by one of its side holes is eliminated because the modified sheath introducer system cannot be advanced into another direction than the ventricular catheter, and because the tube is introduced only in the preoperatively determined depth, which corresponds to the length of the ventricular catheter. Even more, inadvertent effects caused by the current application are eliminated. Further, there is no need
for specially trained personnel—as it would be required for endoscopic and laser techniques.9 Finally, if one intends to place a new ventricular catheter at the same site, one can introduce it via the same tube after having removed the old ventricular catheter. This technique is applicable even in the case of slit ventricle syndrome. However, one has to consider that there is potentially an increased risk of obstruction if the catheter is placed in the same place as the removed catheter. However, even if until now no complications have been seen, it has to be considered that the number of patients is limited, potentially leading to an underestimation of the technique’s complication rate. Theoretically, there are some risks of the described technique: Even if the tube is used as a spherical knife, and the choroid plexus is not torn, the manipulation potentially could cause hemorrhage from the cut surface of plexus or ependyma. Further, it is crucial to determine exactly the catheter’s length preoperatively by radiologic examination. Alternatively, the tube has to be introduced under radiologic control. If this is omitted, the tube can be introduced too far or too short. To insert it too far may lead to injury of the tissue in front of the tip of the catheter, to insert is too short may lead to an incomplete detachment of the catheter with the potential risks described above. Furthermore, for an effective detachment of the adherent catheter it is essential that the tube’s inner diameter exactly corresponds to the outer diameter of the ventricular catheter. If the tube’s diameter is too large, the tube does not work as a spherical knife, but the choroid plexus is torn, instead, or adjacent brain can be injured by shearing. It can be concluded that the technique described for removal of a retained ventricular catheter seems to be an easy, safe, and effective alternative to other techniques. However, the technique described has only been used on 9 patients, and the widely accepted technique of intraluminal cauterization has been used in thousands of patients by many neurosurgeons. Thus, we cannot claim the one technique as superior to the other at this stage. ACKNOWLEDGMENT The authors thank Mrs Lydia Ahn for the artistic drawings.
REFERENCES 1. Becker DP, Nulson FE: Control of hydrocephalus by valveregulated venous shunt: Avoidance of complications in prolonged shunt maintainance. J Neurosurg 28:215-226, 1968 2. Brownlee RD, Dold ONR, Myles ST: Intraventricular hemorrhage complicating ventricular catheter revision: Incidence and effect on shunt survival. Pediatr Neurosurg 22:315-320, 1995 3. Chambi I, Hendrick EB: A technique for removal of an adherent ventricular catheter. Pediatr Neurosci 14:216-217, 1988
4. Collins P, Hockley AD, Woollam DHM: Surface ultrastructure of tissues occluding ventricular catheters. J Neurosurg 48:609-613, 1978 5. Drake JM, Sainte-Rose C: The Shunt Book. Cambridge, MA, Blackwell Science, 1995 6. Forrest DM, Cooper DGW: Complications of ventriculo-atrial shunts. A review of 455 cases. J Neurosurg 29:506-512, 1968 7. Whitefield PC, Guazzo EP, Pickard JD: Safe removal of retained
1798
ventricular catheters using intraluminal choroid plexus coagulation. Technical note. J Neurosurg 83:1101-1102, 1995 8. Chehrazi B, Duncan CC: Removal of retained ventricular shunt catheters without craniotomy. Technical note. J Neurosurg 56:160-161, 1982 9. Crone KR: Endoscopic technique for removal of adherent ventricular catheters, in Manwaring KH, Crone KR (eds): Neuroendoscopy, Vol 1. New York, NY, Mary Ann Liebert, 1992, pp 41-46 10. Steinbok P, Cochrane DD: Removal of adherent ventricular catheter. Pediatr Neurosurg 18:167-168, 1992
REINGES ET AL
11. Chaparro MJ: Shunt removal by choroid plexus coagulation. J Neurosurg 85:981-982, 1996 (letter) 12. Cusimano MD: Shunt removal by choroid plexus coagulation. J Neurosurg 85:982, 1996 (letter) 13. Handler MH: A complication in removing a retained ventricular catheter using electrocautery. Pediatr Neurosurg 25:276, 1996 (letter) 14. Koutzoglou M, Yannopoulos A: Shunt removal by choroid plexus coagulation. J Neurosurg 85:980-981, 1996 (letter)
Background/Purpose: A series of technical notes has been dedicated to the removal of retained intracranial shunt catheters, among which the intraluminal cautery proved to be the most accepted technique. However, several reports showed that these techniques still harbor potentially serious complications. Methods: In this technique, a modified plastic sheath introducer system is passed over the retained ventricular catheter. While advancing the tube along the longitudinal axis of the catheter, circular movements of the tube around the longitudinal axis of the catheter are performed, allowing the tube to act as a spherical knife cutting the ingrown choroid plexus or ependymal adhesions. Results: There were no procedure-related complications in any of the 9 patients treated by the technique described. The
T
HE REMOVAL of obstructed ventricular catheters might be hazardous because of the risk of ventricular bleeding from ingrown choroid plexus and ependymal adhesions.1-7 To facilitate removal of retained intracranial shunt catheters, several technical notes have been published, and intraluminal cautery is the most accepted technique.3,7-10 However, several reports found that these techniques still harbor potentially serious complications.10-14 MATERIALS AND METHODS A commercially available sheath introducer system (Cordis Corporation, Miami, FL) is modified by cutting off the upper part of the system (Fig 1). Only the so-revealed plastic tube is used (Fig 1). The extracranial shunt hardware is disconnected from the ventricular catheter after having fixed the exposed distal end of the ventricular catheter by suture not to allow it to escape into the ventricular system (Fig 2). The thread is then pulled through the modified sheath introducer system, which is carefully passed over the ventricular catheter (Fig 2B). Note that the tube must fit exactly over the catheter to avoid shearing of adjacent brain tissue. While advancing the tube along the longitudinal axis of the catheter, circular movements of the tube around the longitudinal axis of the catheter are performed, allowing the tube to act as a spherical knife cutting the ingrown choroid plexus or ependymal adhesions (Fig 2C). After introducing the tube to a depth corresponding to the length of the ventricular catheter, the ventricular catheter is removed via the tube. Sometimes one has the feeling of “giving way” of the ventricular catheter when the tube has reached the ventricular catheter’s end. In case a new ventricular catheter has to be placed at the same site, it can be introduced through the same tube. The technique described was applied in 9 patients, 5 children, and 4 adults undergoing shunt revision for proximal catheter obstruction with a retained ventricular catheter. In 7 patients a retained frontal ventricular catheter, and in 2 patients a retained occipital ventricular catheter
procedure proved to be easy and effective in all cases. In addition, in case a new ventricular catheter was needed at the same site, it could be placed via the same tube.
Conclusions: The technique described seems to be an easy, safe, and effective alternative to other techniques for removal of retained ventricular catheters. However, considering the limited number of patients treated with the technique described and the great number of patients treated by the widely accepted intraluminal cautery, one cannot claim the one technique as superior to the other at this stage. J Pediatr Surg 35:1795-1798. Copyright © 2000 by W.B. Saunders Company. INDEX WORDS: Choroid plexus, hydrocephalus, intraluminal cautery, retained ventricular catheter, shunt, shunt complication, shunt revision.
was removed successfully. In 5 patients the adherent catheter was removed, and a new ventricular catheter was introduced via the same tube; in the remaining 4 patients the tube was only used for removal of the adherent catheter. The following case is a typical example. In this 6-year-old boy a pilocytic astrocytoma of the hypothalamus was partially removed, and a right frontal ventriculoperitoneal shunt was inserted at the age of 1 year. Four years later, the child presented with symptoms of increased intracranial pressure. Computed tomography (CT) examination showed small ventricles, and lumbar puncture results showed an opening pressure of 50 cm H2O. Shunt tapping confirmed proximal catheter obstruction. Thus, the indication for shunt revision was given. Intraoperatively, no cerebral spinal fluid (CSF) could be aspirated through the ventricular catheter, and the ventricular catheter was found to be adherent. Because of the proven small size ventricles it was expected to be difficult to introduce a new ventricular catheter. Therefore, the technique described above for removal of the ventricular catheter was used. After removal of the ventricular catheter without complications, a new ventricular catheter was introduced via the same tube. Finally, the tube was removed, and the new ventricular catheter was connected with the remaining shunt hardware. In the course of, and after the procedure, no signs for intraventricular hemorrhage or other complications were observed. The patient’s symptoms were relieved completely, and the postoperative CT scan showed correct placement of the new ventricular catheter.
From the Department of Neurosurgery, University of Technology (RWTH), Aachen, Germany. Address reprint requests to Marcus H.T. Reinges, MD, Department of Neurosurgery, University of Technology (RWTH), Pauwelsstr. 30, D-52057 Aachen, Germany. Copyright © 2000 by W.B. Saunders Company 0022-3468/00/3512-0023$03.00/0 doi:10.1053/jpsu.2000.19260
Journal of Pediatric Surgery, Vol 35, No 12 (December), 2000: pp 1795-1798
1795
1796
REINGES ET AL
Fig 1. (A) Below: The original sheath introducer system (Cordis Corporation, Miami, FL). Above: The revealed tube after having cut off the upper part of the original system. (B) View into the distal end of the tube.
Fig 2. Schematic drawing of the technique for removal of an adherent ventricular catheter by a modified sheath introducer system used as spherical knife. In the drawing an occipital catheter is removed; however, the technique can be used in any location of the catheter. (A) Overview. (B, C) Partial magnification of (A) with cross-section (below). After disconnection of the extracranial hardware from the ventricular catheter the exposed distal end of the ventricular catheter is sewed to avoid the catheter sliding into the ventricular system (A). The thread is pulled through the tube, which is carefully passed over the ventricular catheter (A and B). While advancing the tube, circular movements around the longitudinal axis of the catheter are performed to use the tube as a spherical knife so that choroid plexus which pervades the holes in the catheter is cut (C).
REMOVAL OF VENTRICULAR CATHETERS
1797
RESULTS
In all 9 patients shunt removal was easily possible using the technique described. Ingrowth of the choroid plexus into the ventricular catheter could be seen after catheter removal in all patients. In the 5 patients in which a new catheter was introduced through the same tube, correct placement of the catheter was achieved. There were no procedure-related complications in any of the patients. DISCUSSION
A series of technical notes has been dedicated to the removal of retained intracranial shunt catheters, among which the intraluminal cautery described by Chambi and Hendrick3 and by Whitfield et al proved to be the most accepted technique.7-10 However, these techniques— especially that of the widely accepted intraluminal cautery— harbor potentially serious complications.10-14 For example, a burn at the site of the cautery grading plate, a charring of the ventricular catheter, intraventricular hemorrhage, or a passing of the stylet’s tip through one of the catheter’s side holes has been reported using the technique of intraluminal cautery.10,12-14 Likewise, the presented technique for removal of retained ventricular catheters bears the risk of intraventricular hemorrhage. However, in none of our 9 patients was this complication seen. The reason may be that the choroid plexus that is ingrown into ventricular catheter drainage holes and ependymal adhesions are detached from the catheter immediately at the site of ingrowth or adhesion, and that there cannot be any rest of adherent tissue after the procedure. In contrast, using the technique of intraluminal cautery one cannot be sure of having detached these structures completely. Further, the risk of bleeding or tissue injury by the stylet’s tip inadvertently leaving the catheter by one of its side holes is eliminated because the modified sheath introducer system cannot be advanced into another direction than the ventricular catheter, and because the tube is introduced only in the preoperatively determined depth, which corresponds to the length of the ventricular catheter. Even more, inadvertent effects caused by the current application are eliminated. Further, there is no need
for specially trained personnel—as it would be required for endoscopic and laser techniques.9 Finally, if one intends to place a new ventricular catheter at the same site, one can introduce it via the same tube after having removed the old ventricular catheter. This technique is applicable even in the case of slit ventricle syndrome. However, one has to consider that there is potentially an increased risk of obstruction if the catheter is placed in the same place as the removed catheter. However, even if until now no complications have been seen, it has to be considered that the number of patients is limited, potentially leading to an underestimation of the technique’s complication rate. Theoretically, there are some risks of the described technique: Even if the tube is used as a spherical knife, and the choroid plexus is not torn, the manipulation potentially could cause hemorrhage from the cut surface of plexus or ependyma. Further, it is crucial to determine exactly the catheter’s length preoperatively by radiologic examination. Alternatively, the tube has to be introduced under radiologic control. If this is omitted, the tube can be introduced too far or too short. To insert it too far may lead to injury of the tissue in front of the tip of the catheter, to insert is too short may lead to an incomplete detachment of the catheter with the potential risks described above. Furthermore, for an effective detachment of the adherent catheter it is essential that the tube’s inner diameter exactly corresponds to the outer diameter of the ventricular catheter. If the tube’s diameter is too large, the tube does not work as a spherical knife, but the choroid plexus is torn, instead, or adjacent brain can be injured by shearing. It can be concluded that the technique described for removal of a retained ventricular catheter seems to be an easy, safe, and effective alternative to other techniques. However, the technique described has only been used on 9 patients, and the widely accepted technique of intraluminal cauterization has been used in thousands of patients by many neurosurgeons. Thus, we cannot claim the one technique as superior to the other at this stage. ACKNOWLEDGMENT The authors thank Mrs Lydia Ahn for the artistic drawings.
REFERENCES 1. Becker DP, Nulson FE: Control of hydrocephalus by valveregulated venous shunt: Avoidance of complications in prolonged shunt maintainance. J Neurosurg 28:215-226, 1968 2. Brownlee RD, Dold ONR, Myles ST: Intraventricular hemorrhage complicating ventricular catheter revision: Incidence and effect on shunt survival. Pediatr Neurosurg 22:315-320, 1995 3. Chambi I, Hendrick EB: A technique for removal of an adherent ventricular catheter. Pediatr Neurosci 14:216-217, 1988
4. Collins P, Hockley AD, Woollam DHM: Surface ultrastructure of tissues occluding ventricular catheters. J Neurosurg 48:609-613, 1978 5. Drake JM, Sainte-Rose C: The Shunt Book. Cambridge, MA, Blackwell Science, 1995 6. Forrest DM, Cooper DGW: Complications of ventriculo-atrial shunts. A review of 455 cases. J Neurosurg 29:506-512, 1968 7. Whitefield PC, Guazzo EP, Pickard JD: Safe removal of retained
1798
ventricular catheters using intraluminal choroid plexus coagulation. Technical note. J Neurosurg 83:1101-1102, 1995 8. Chehrazi B, Duncan CC: Removal of retained ventricular shunt catheters without craniotomy. Technical note. J Neurosurg 56:160-161, 1982 9. Crone KR: Endoscopic technique for removal of adherent ventricular catheters, in Manwaring KH, Crone KR (eds): Neuroendoscopy, Vol 1. New York, NY, Mary Ann Liebert, 1992, pp 41-46 10. Steinbok P, Cochrane DD: Removal of adherent ventricular catheter. Pediatr Neurosurg 18:167-168, 1992
REINGES ET AL
11. Chaparro MJ: Shunt removal by choroid plexus coagulation. J Neurosurg 85:981-982, 1996 (letter) 12. Cusimano MD: Shunt removal by choroid plexus coagulation. J Neurosurg 85:982, 1996 (letter) 13. Handler MH: A complication in removing a retained ventricular catheter using electrocautery. Pediatr Neurosurg 25:276, 1996 (letter) 14. Koutzoglou M, Yannopoulos A: Shunt removal by choroid plexus coagulation. J Neurosurg 85:980-981, 1996 (letter)