- Email: [email protected]
Distal Ventriculoatrial Shunt Revision in Adult Myelomeningocele Patient Performed via Endovascular Transvenous Approach
Accepted Manuscript Distal ventriculoatrial shunt revision in an adult myelomeningocele patient performed via endovascular transvenous approach: a case report Abigail J. Rao, MD, Zoe Teton, BS, Victor Rodriguez, MD, Brandon H. Tieu, MD, Ahmed M. Raslan, MD PII:
S1878-8750(18)32175-2
DOI:
10.1016/j.wneu.2018.09.129
Reference:
WNEU 10334
To appear in:
World Neurosurgery
Received Date: 6 September 2018 Accepted Date: 17 September 2018
Please cite this article as: Rao AJ, Teton Z, Rodriguez V, Tieu BH, Raslan AM, Distal ventriculoatrial shunt revision in an adult myelomeningocele patient performed via endovascular transvenous approach: a case report, World Neurosurgery (2018), doi: https://doi.org/10.1016/j.wneu.2018.09.129. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Distal ventriculoatrial shunt revision in an adult myelomeningocele patient performed via endovascular transvenous approach: a case report Abigail J. Rao, MD,a,1 Zoe Teton BS,b Victor Rodriguez, MD,c ,2 Brandon H. Tieu, MD,d and Ahmed M. Raslan, MDe
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a
Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon [email protected] 1
Department of Neurosurgery, University of California-Los Angeles, Los Angeles, California
Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon [email protected]
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b
c
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Division of Cardiothoracic Surgery, Department of Surgery, Oregon Health & Science University, Portland, Oregon [email protected] 2
Division of Cardiothoracic Surgery, Department of Surgery, University of California-Davis Sacramento, California
d
Division of Cardiothoracic Surgery, Department of Surgery, Oregon Health & Science University, Portland, Oregon [email protected]
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e
Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon [email protected]
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Corresponding author: Ahmed M. Raslan, MD Department of Neurological Surgery Oregon Health & Science University Mail Code CH8N 3303 SW Bond Avenue Portland, Oregon 97239 Phone: 503-494-4314 Fax: 503-346-6810 Email: [email protected]
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
Abstract Background: Myelomeningocele patients with shunt-dependent hydrocephalus often require multiple shunt revisions, eventually exhausting first-line distal diversion sites. Ventriculoatrial
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(VA) shunts are used less commonly than ventriculoperitoneal (VP) shunts, but knowledge of their use and complications is important to the neurosurgeon’s armamentarium. VA shunts differ from VP and ventriculopleural shunts in that the ideal distal catheter target is an anatomically
SC
small area in comparison to the peritoneal and pleural cavities.
Case description: Here we present a case of an adult myelomeningocele patient who experienced
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migration of a distal VA shunt catheter. A minimally invasive revision technique that does not require recannulation of the vessels or open manipulation of the shunt is presented. Conclusions: This is the fourth reported instance of successful distal revision of a migrated VA shunt catheter via transfemoral endovascular snaring. Knowledge of the opportunities afforded
neurosurgeons.
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by this technique, and collaboration with thoracic surgery colleagues, is of benefit to all
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Key Words: cerebrospinal fluid diversion, endovascular, hydrocephalus, myelomeningocele,
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revision, ventriculoatrial shunt
1
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
Introduction Myelomeningocele is a congenital malformation of the neural tube that frequently is associated with a disproportionately small posterior fossa, Chiari II malformation, and
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hydrocephalus.1 The classic treatment for this etiology of hydrocephalus is spinal fluid diversion via ventricular shunt implantation or endoscopic third ventriculostomy. Amongst patients with myelomeningocele, about 80-85% require shunt placement, which typically is performed in the
SC
neonatal period.1 Myelomeningocele patients typically are shunt-dependent into adulthood2 and 95% of adult patients with myelomeningocele require at least one shunt revision during their
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lifetime.3 This continued requirement for a functioning shunt system can be challenging in this patient population, as adequate spinal fluid diversion sites become increasingly challenging to identify.
The first anatomical choice for long-term spinal fluid diversion often is the peritoneum,
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with subsequent choices including the pleural cavity, cavoatrial junction, gall bladder, and ureter. Each type of shunt carries different long-term morbidities and surgical challenges for revision surgery. Ventriculoatrial (VA) shunts in particular can be complicated by arrhythmias,
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pulmonary embolism, pulmonary hypertension, cor pulmonale, atrial thrombus formation, shunt nephritis, septicemia, and distal catheter migration. The ideal site for the distal catheter of a VA
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shunt is the cavoatrial junction. Imaging modalities such as fluoroscopy, ultrasound, and echocardiography have been used to aid in proper placement of the distal catheter. However, there are few reports of endovascular techniques that offer a less invasive option for distal catheter placement or revision. Here we report a unique case of a migrated distal VA shunt catheter, which was revised using a minimally invasive, endovascular approach.
2
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
Case Report A 55-year-old man with thoracic myelomeningocele and a left VA shunt presented to our service with signs and symptoms of hydrocephalus, including poor appetite, headaches, and
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ventriculomegaly. He had a left VA shunt in place, which was last revised 5 years prior for distal catheter failure. He had failed multiple prior VP shunts due to intra-abdominal scarring, and had failed ventriculopleural shunting due to symptomatic large pleural effusion.
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At the time of this patient’s initial presentation to our service, we made a clinical diagnosis of shunt failure, supported by head computed tomography (CT) showing
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ventriculomegaly (Figure, panel A) and radionuclide shunt patency study indicated distal VA shunt failure. He also presented with a urinary tract infection, so his hydrocephalus initially was temporized with a ventriculostomy to allow for infectious treatment prior to shunt revision. The patient then underwent complete left VA shunt revision upon resolution of the infection. Given
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our concern for jugular venous occlusion causing the distal failure, a new distal catheter was placed via the left subclavian vein into the right atrium. The great veins of the right side of the neck were not instrumented, given that orphaned and fractured shunt tubing was observed on x-
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ray. This suggested that right neck access for a VA shunt may have previously failed due to occlusion. If right neck venous occlusion were not already present, then attempted right-sided
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VA shunt placement carries a risk of creating an occlusion that would limit the patient’s remaining venous outflow from the brain. As such, we elected to place a new left VA shunt system with new distal catheter in the subclavian vein, programmable valve, and antibioticimpregnated components.
Using ultrasonic guidance, percutaneous access to the left subclavian vein was obtained, and a peel-away sheath was advanced into the vein, using the Seldinger technique. A distal shunt
3
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
catheter, which was tunneled down from the cranium after connection with a new programmable valve and frontal proximal catheter, was manually advanced into the right cavoatrial junction under fluoroscopic guidance, with the aid of thoracic surgeons. Immediate post-operative
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imaging showed appropriate distal catheter placement (Figure, panels B and C).
The patient recovered well from this surgery and experienced alleviation of his
hydrocephalus symptoms and reduced ventricular size. He presented approximately 2 months
SC
later with altered mentation despite our adjusting the programmable valve to lower pressure settings. Chest imaging demonstrated that the distal catheter terminated in the azygos vein, rather
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than the cavoatrial junction (Figure panel D). After discussion of this presumed migration of the catheter with the thoracic surgeons, a decision was made to first attempt endovascular revision of the distal catheter, rather than re-opening the cranial incisions and handling the shunt components. As such, the thoracic surgery team obtained transvenous access via both the right
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and left common femoral veins. An angled glide wire was navigated from the left common femoral vein across the iliac system and into the superior vena cava via the inferior vena cava and right atrium. Two endovascular wires were then used to encircle the distal shunt catheter. A
EP
snare system was created to pull the shunt catheter out of the azygos vein inferiorly and into the cavoatrial junction (Figure panel E). Some stenosis of the cavoatrial junction was noted, but right
AC C
atrial pressures measured appropriately low, at 7-9 mmHg. The patient tolerated this procedure well, and experienced improvement of his mentation and ventriculomegaly. He discharged home shortly thereafter, and has remained neurologically stable ever since. CT head obtained one month later shows decreased ventricular volumes (Figure panel F). At clinic follow-up one year later, the patient and his caregiver denied any signs or symptoms of shunt failure.
4
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
Discussion VA shunt placement was first described in 1955, about 60 years after spinal fluid diversion into the venous system was first suggested.4 Although VP shunts remain the most
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common first line shunt performed in cases of hydrocephalus necessitating shunt placement, VA shunts offer a solution for spinal fluid diversion when prior abdominal surgery, ascites, prior pseudocyst, prior distal site infection, or poor pulmonary reserve complicate the peritoneal and
SC
pleural cavities. Use of the venous system as a spinal fluid diversion site also offers a
consistently low-pressure site for drainage, thus avoiding the challenges that a pressure gradient
M AN U
created by high intraabdominal or intrathoracic pressure can create for adequate spinal fluid drainage. In fact, some studies5,6 have explored the safety of VA shunts as an alternative to VP shunts for the treatment of normal pressure hydrocephalus, and have found low rates of shunt obstruction and shunt revision with VA shunts.7
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Shunt complications of obstruction, infection, and breakage are all associated with distal drainage sites. However, there are renal and cardiopulmonary morbidities unique to VA shunts, including pulmonary embolism, pulmonary hypertension, cor pulmonale, atrial thrombus
EP
formation, shunt nephritis, septicemia, and distal catheter thrombosis or migration.8 Infectious complications, including shunt nephritis, necessitate expeditious removal of the entire shunt
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system. Management of cardiopulmonary complications often requires removal of the shunt and possible anticoagulation.7 One challenge unique to the initial placement of VA shunts is that the distal target site is much more defined anatomically. The distal catheter’s intravascular nature and proximity to the heart necessities that the ideal catheter length must be more precise, as compared with cases when the distal drainage site is a large body cavity. This small margin of
5
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
error for distal catheter length means that young patients with VA shunts often need to undergo elective revision for lengthening as the patients grow into adulthood. In the evolution of VA shunt surgical techniques, a number of advances have led to less
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invasive and more accurate distal catheter placement. Ultrasound and the Seldinger technique (rather than open neck dissection) are now routinely used to visualize the chosen vein of entry – often the internal jugular, and less commonly, the external jugular or facial vein.
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Transesophageal echocardiography has been used for real-time visual verification of proper placement of the distal catheter at the cavoatrial junction.7,8 Regarding catheter migration, there
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are reports of fractured VA shunt fragments migrating into the pulmonary artery9,10 or right atrium,11,12 in patients presenting with symptoms of raised intracranial pressure. In all these cases, the fragments were retrieved via an endovascular approach.
When our patient presented 2 months after his complete VA shunt revision with signs and
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symptoms of shunt failure and an intact distal catheter that had migrated into the azygos vein, we questioned whether the azygos vein would provide adequate drainage, should the shunt system be patent. In the literature, there is little discussion of the azygos vein as an intended distal
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diversion site. There is one report of the azygos vein used as a distal drainage site in a child with bronchopulmonary dysplasia and a patent ductus arteriosus.2 In this case, access was obtained
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via thoracotomy. This was felt to be a reasonable solution given that patient’s relatively inaccessible deep venous system. It also allowed for the placement of redundant catheter in the thoracic cavity, thereby minimizing the need for revisions due to outgrown catheter. However, we did not have any basis in the literature for deciding whether the azygos vein would serve as an adequate distal site in our adult patient with myelomeningocele-related hydrocephalus.
6
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
As such, we decided that a revision was necessary and elected to first attempt an endovascular revision of the distal catheter’s location. This is one of only 4 reported cases of a successful snare and relocation of a distal catheter via an endovascular technique. In 1972, a
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similar approach was first reported by Dr. McSweeney, who performed this in a 5 year-old boy.13 He describes a misplaced distal VA shunt catheter that was in the left innominate vein near its junction with the vertebral vein and was causing arrhythmias that were noted intraoperatively.
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The child’s femoral vein could not be accessed, so a left saphenous vein cut-down was
performed and a catheter with a deflector was advanced up through the right atrium. The
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vascular access catheter was then hooked around the shunt catheter and pulled down to the intended location. In 2007, Gonzalez et al.,1 described transvenous endovascular manipulation of a shunt catheter, but the technique used was far more invasive. It required open surgical access to and into the internal jugular vein, with a temporary connection made between the transvenously-
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placed distal catheter and the true distal shunt catheter that was intended to remain at the cavoatrial junction. In contrast, the technique we present does not require any open access of the great vessels, which often are scarred and fragile in such complex cases.
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To our knowledge, there are no other reports of endovascular repositioning of a distal VA shunt catheter until 2012. Xu et al.,14 published a case in which intraoperative x-ray taken during
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a VA shunt placement, which was performed by open access to the left facial vein, showed shunt catheter looping within the left internal jugular vein just above the level of the subclavian vein. The authors then accessed the left femoral vein and employed an endovascular loop snare to pull the coiled shunt catheter down into the right atrium. As such, the case we present represents only the fourth report of an endovascular transvenous technique used to revise an intact distal VA shunt catheter.
7
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
A technical disadvantage of this technique is that it does not allow for complete interrogation of the shunt system by manometry, as would be possible with disconnecting the valve, distal catheter and proximal catheter. Surgeons must keep in mind that if the technique we
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describe is employed to address malposition of the catheter, catheter occlusion must still be ruled out if the patient does not improve clinically.
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Conclusions
Distal revision of a VA shunt may be necessary due to a migrated distal catheter, and this
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unique endovascular approach allows for direct snaring and manipulation of the distal catheter
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without open access and handling of the shunt components.
8
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
References 1.
L.F. Gonzalez, L. Kim, H.L. Rekate, C.G. McDougall, F.C. Albuquerque, Endovascular placement of a ventriculoatrial shunt, J Neurosurg Pediatr 106, 2007, 319-321 S.F. Redo, A. Ciccarelli, J. Ghajar, M. Dinner, Ventriculoatrial shunt utilizing the azygos
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2.
vein, J Pediatr Surg 27, 1992, 642-644 3.
S.K. Konar, T.K. Maiti, S.C. Bir, P. Kalakoti, A. Nanda, Robert H. Pudenz (1911–1998)
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and Ventriculoatrial Shunt: Historical Perspective, World Neurosurg 84, 2015, 14371440
R.A. McGovern, K.M. Kelly, A.K. Chan, N.J. Morrissey, G.M. McKhann, Should
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4.
ventriculoatrial shunting be the procedure of choice for normal-pressure hydrocephalus?, J Neurosurg 120, 2014, 1458-1464 5.
B.W. Hanak, R.H. Bonow, C.A. Harris, S.R. Browd, Cerebrospinal Fluid Shunting
6.
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Complications in Children, Pediatr Neurosurg 52, 2017, 381-400 O. Karahan, C. Yavuz, S. Demirtas, A. Caliskan, K. Kamasak, O. Guclu, et al., Reasons, procedures, and outcomes in ventriculoatrial shunts: A single-center experience, Surg
7.
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Neurol Int 4, 2013, 10
T.G. Machinis, K.N. Fountas, J. Hudson, J.S. Robinson, E.C. Troup, Accurate placement
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of the distal end of a ventriculoatrial shunt with the aid of real-time transesophageal
echocardiography, J Neurosurg 105, 2006, 153-156
8.
H.L. Chuang, C.N. Chang, J.C. Hsu, Minimally invasive procedure for ventriculoatrial shunt-combining a percutaneous approach with real-time transesophageal
echocardiogram monitoring: report of six cases, Chang Gung Med J 25, 2002, 62-66 9.
C.A. James, D.R. McFarland, C.J. Wormuth, C.M. Teo, Snare retrieval of migrated ventriculoatrial shunt, Pediatr Radiol 27, 1997, 330-332 9
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
10.
A. Surov, G. Koman, C. Behrmann, C. Strauß, M. Kornhuber, A rare cause of ventriculoatrial shunt malfunction, Clin Neurol Neurosurg 111, 2009, 310-311
11.
T. Mori, M. Arisawa, M. Fukuoka, K. Tamura, M. Kurisaka, K. Mori, Management of a
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Broken Atrial Catheter Migrated into the Heart: A Rare Complication of Ventriculoatrial Shunt —Case Report—, Neurol Med Chir (Tokyo) 33, 1993, 713-715 12.
T. Tatsumi, W.J. Howland, Retrieval of a Ventriculoatrial Shunt Catheter from the Heart
W.J. McSweeney, Intravascular repositioning of a ventriculoatrial shunt. Technical note, J Neurosurg 36, 1972, 512-514
14.
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13.
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by a Venous Catheterization Technique, J Neurosurg 32, 1970, 593-596
B. Xu, S. Chotai, K. Yang, W. Feng, G. Zhang, M. Li, et al., Endovascular Intervention for Repositioning the Distal Catheter of Ventriculo-Atrial Shunt, Neurointervention 7,
Figure Caption
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2012, 109
At the patient’s initial presentation, computed tomography (CT) showed overt ventriculomegaly
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(A). After placement of a new left VA shunt with vascular access obtained to the left subclavian vein, post-operative chest x-ray (B) and chest CT (C) showed expected termination of the VA
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shunt at the cavoatrial junction (arrowhead) and not in azygos vein (arrow). At re-presentation, CT showed that the distal shunt catheter had migrated to the azygos vein (D, arrow). After endovascular distal revision for repositioning of the catheter to the cavoatrial junction (E), the patient recovered well. Follow-up CT 1 month later shows smaller ventricular volumes (F).
10
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ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
HIGHLIGHTS (maximum 85 characters, including spaces, per bullet point). •
Myelomeningocele patients typically have shunt-dependent hydrocephalus
•
Ventriculoatrial (VA) shunts: an important option for cerebrospinal fluid
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diversion
Reported is a unique case of distal VA shunt revision via endovascular snare
•
This technique allows for minimally invasive VA shunt revision
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SC
•
ACCEPTED MANUSCRIPT
Abbreviations computed tomography (CT) ventriculoatrial (VA)
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ventriculoperitoneal (VP)
ACCEPTED MANUSCRIPT
Disclosure The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.
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Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
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Acknowledgements
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We wish to thank Shirley McCartney Ph.D. for editorial assistance.
S1878-8750(18)32175-2
DOI:
10.1016/j.wneu.2018.09.129
Reference:
WNEU 10334
To appear in:
World Neurosurgery
Received Date: 6 September 2018 Accepted Date: 17 September 2018
Please cite this article as: Rao AJ, Teton Z, Rodriguez V, Tieu BH, Raslan AM, Distal ventriculoatrial shunt revision in an adult myelomeningocele patient performed via endovascular transvenous approach: a case report, World Neurosurgery (2018), doi: https://doi.org/10.1016/j.wneu.2018.09.129. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Distal ventriculoatrial shunt revision in an adult myelomeningocele patient performed via endovascular transvenous approach: a case report Abigail J. Rao, MD,a,1 Zoe Teton BS,b Victor Rodriguez, MD,c ,2 Brandon H. Tieu, MD,d and Ahmed M. Raslan, MDe
RI PT
a
Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon [email protected] 1
Department of Neurosurgery, University of California-Los Angeles, Los Angeles, California
Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon [email protected]
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b
c
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Division of Cardiothoracic Surgery, Department of Surgery, Oregon Health & Science University, Portland, Oregon [email protected] 2
Division of Cardiothoracic Surgery, Department of Surgery, University of California-Davis Sacramento, California
d
Division of Cardiothoracic Surgery, Department of Surgery, Oregon Health & Science University, Portland, Oregon [email protected]
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e
Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon [email protected]
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Corresponding author: Ahmed M. Raslan, MD Department of Neurological Surgery Oregon Health & Science University Mail Code CH8N 3303 SW Bond Avenue Portland, Oregon 97239 Phone: 503-494-4314 Fax: 503-346-6810 Email: [email protected]
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
Abstract Background: Myelomeningocele patients with shunt-dependent hydrocephalus often require multiple shunt revisions, eventually exhausting first-line distal diversion sites. Ventriculoatrial
RI PT
(VA) shunts are used less commonly than ventriculoperitoneal (VP) shunts, but knowledge of their use and complications is important to the neurosurgeon’s armamentarium. VA shunts differ from VP and ventriculopleural shunts in that the ideal distal catheter target is an anatomically
SC
small area in comparison to the peritoneal and pleural cavities.
Case description: Here we present a case of an adult myelomeningocele patient who experienced
M AN U
migration of a distal VA shunt catheter. A minimally invasive revision technique that does not require recannulation of the vessels or open manipulation of the shunt is presented. Conclusions: This is the fourth reported instance of successful distal revision of a migrated VA shunt catheter via transfemoral endovascular snaring. Knowledge of the opportunities afforded
neurosurgeons.
TE D
by this technique, and collaboration with thoracic surgery colleagues, is of benefit to all
EP
Key Words: cerebrospinal fluid diversion, endovascular, hydrocephalus, myelomeningocele,
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revision, ventriculoatrial shunt
1
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
Introduction Myelomeningocele is a congenital malformation of the neural tube that frequently is associated with a disproportionately small posterior fossa, Chiari II malformation, and
RI PT
hydrocephalus.1 The classic treatment for this etiology of hydrocephalus is spinal fluid diversion via ventricular shunt implantation or endoscopic third ventriculostomy. Amongst patients with myelomeningocele, about 80-85% require shunt placement, which typically is performed in the
SC
neonatal period.1 Myelomeningocele patients typically are shunt-dependent into adulthood2 and 95% of adult patients with myelomeningocele require at least one shunt revision during their
M AN U
lifetime.3 This continued requirement for a functioning shunt system can be challenging in this patient population, as adequate spinal fluid diversion sites become increasingly challenging to identify.
The first anatomical choice for long-term spinal fluid diversion often is the peritoneum,
TE D
with subsequent choices including the pleural cavity, cavoatrial junction, gall bladder, and ureter. Each type of shunt carries different long-term morbidities and surgical challenges for revision surgery. Ventriculoatrial (VA) shunts in particular can be complicated by arrhythmias,
EP
pulmonary embolism, pulmonary hypertension, cor pulmonale, atrial thrombus formation, shunt nephritis, septicemia, and distal catheter migration. The ideal site for the distal catheter of a VA
AC C
shunt is the cavoatrial junction. Imaging modalities such as fluoroscopy, ultrasound, and echocardiography have been used to aid in proper placement of the distal catheter. However, there are few reports of endovascular techniques that offer a less invasive option for distal catheter placement or revision. Here we report a unique case of a migrated distal VA shunt catheter, which was revised using a minimally invasive, endovascular approach.
2
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
Case Report A 55-year-old man with thoracic myelomeningocele and a left VA shunt presented to our service with signs and symptoms of hydrocephalus, including poor appetite, headaches, and
RI PT
ventriculomegaly. He had a left VA shunt in place, which was last revised 5 years prior for distal catheter failure. He had failed multiple prior VP shunts due to intra-abdominal scarring, and had failed ventriculopleural shunting due to symptomatic large pleural effusion.
SC
At the time of this patient’s initial presentation to our service, we made a clinical diagnosis of shunt failure, supported by head computed tomography (CT) showing
M AN U
ventriculomegaly (Figure, panel A) and radionuclide shunt patency study indicated distal VA shunt failure. He also presented with a urinary tract infection, so his hydrocephalus initially was temporized with a ventriculostomy to allow for infectious treatment prior to shunt revision. The patient then underwent complete left VA shunt revision upon resolution of the infection. Given
TE D
our concern for jugular venous occlusion causing the distal failure, a new distal catheter was placed via the left subclavian vein into the right atrium. The great veins of the right side of the neck were not instrumented, given that orphaned and fractured shunt tubing was observed on x-
EP
ray. This suggested that right neck access for a VA shunt may have previously failed due to occlusion. If right neck venous occlusion were not already present, then attempted right-sided
AC C
VA shunt placement carries a risk of creating an occlusion that would limit the patient’s remaining venous outflow from the brain. As such, we elected to place a new left VA shunt system with new distal catheter in the subclavian vein, programmable valve, and antibioticimpregnated components.
Using ultrasonic guidance, percutaneous access to the left subclavian vein was obtained, and a peel-away sheath was advanced into the vein, using the Seldinger technique. A distal shunt
3
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
catheter, which was tunneled down from the cranium after connection with a new programmable valve and frontal proximal catheter, was manually advanced into the right cavoatrial junction under fluoroscopic guidance, with the aid of thoracic surgeons. Immediate post-operative
RI PT
imaging showed appropriate distal catheter placement (Figure, panels B and C).
The patient recovered well from this surgery and experienced alleviation of his
hydrocephalus symptoms and reduced ventricular size. He presented approximately 2 months
SC
later with altered mentation despite our adjusting the programmable valve to lower pressure settings. Chest imaging demonstrated that the distal catheter terminated in the azygos vein, rather
M AN U
than the cavoatrial junction (Figure panel D). After discussion of this presumed migration of the catheter with the thoracic surgeons, a decision was made to first attempt endovascular revision of the distal catheter, rather than re-opening the cranial incisions and handling the shunt components. As such, the thoracic surgery team obtained transvenous access via both the right
TE D
and left common femoral veins. An angled glide wire was navigated from the left common femoral vein across the iliac system and into the superior vena cava via the inferior vena cava and right atrium. Two endovascular wires were then used to encircle the distal shunt catheter. A
EP
snare system was created to pull the shunt catheter out of the azygos vein inferiorly and into the cavoatrial junction (Figure panel E). Some stenosis of the cavoatrial junction was noted, but right
AC C
atrial pressures measured appropriately low, at 7-9 mmHg. The patient tolerated this procedure well, and experienced improvement of his mentation and ventriculomegaly. He discharged home shortly thereafter, and has remained neurologically stable ever since. CT head obtained one month later shows decreased ventricular volumes (Figure panel F). At clinic follow-up one year later, the patient and his caregiver denied any signs or symptoms of shunt failure.
4
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
Discussion VA shunt placement was first described in 1955, about 60 years after spinal fluid diversion into the venous system was first suggested.4 Although VP shunts remain the most
RI PT
common first line shunt performed in cases of hydrocephalus necessitating shunt placement, VA shunts offer a solution for spinal fluid diversion when prior abdominal surgery, ascites, prior pseudocyst, prior distal site infection, or poor pulmonary reserve complicate the peritoneal and
SC
pleural cavities. Use of the venous system as a spinal fluid diversion site also offers a
consistently low-pressure site for drainage, thus avoiding the challenges that a pressure gradient
M AN U
created by high intraabdominal or intrathoracic pressure can create for adequate spinal fluid drainage. In fact, some studies5,6 have explored the safety of VA shunts as an alternative to VP shunts for the treatment of normal pressure hydrocephalus, and have found low rates of shunt obstruction and shunt revision with VA shunts.7
TE D
Shunt complications of obstruction, infection, and breakage are all associated with distal drainage sites. However, there are renal and cardiopulmonary morbidities unique to VA shunts, including pulmonary embolism, pulmonary hypertension, cor pulmonale, atrial thrombus
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formation, shunt nephritis, septicemia, and distal catheter thrombosis or migration.8 Infectious complications, including shunt nephritis, necessitate expeditious removal of the entire shunt
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system. Management of cardiopulmonary complications often requires removal of the shunt and possible anticoagulation.7 One challenge unique to the initial placement of VA shunts is that the distal target site is much more defined anatomically. The distal catheter’s intravascular nature and proximity to the heart necessities that the ideal catheter length must be more precise, as compared with cases when the distal drainage site is a large body cavity. This small margin of
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ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
error for distal catheter length means that young patients with VA shunts often need to undergo elective revision for lengthening as the patients grow into adulthood. In the evolution of VA shunt surgical techniques, a number of advances have led to less
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invasive and more accurate distal catheter placement. Ultrasound and the Seldinger technique (rather than open neck dissection) are now routinely used to visualize the chosen vein of entry – often the internal jugular, and less commonly, the external jugular or facial vein.
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Transesophageal echocardiography has been used for real-time visual verification of proper placement of the distal catheter at the cavoatrial junction.7,8 Regarding catheter migration, there
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are reports of fractured VA shunt fragments migrating into the pulmonary artery9,10 or right atrium,11,12 in patients presenting with symptoms of raised intracranial pressure. In all these cases, the fragments were retrieved via an endovascular approach.
When our patient presented 2 months after his complete VA shunt revision with signs and
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symptoms of shunt failure and an intact distal catheter that had migrated into the azygos vein, we questioned whether the azygos vein would provide adequate drainage, should the shunt system be patent. In the literature, there is little discussion of the azygos vein as an intended distal
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diversion site. There is one report of the azygos vein used as a distal drainage site in a child with bronchopulmonary dysplasia and a patent ductus arteriosus.2 In this case, access was obtained
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via thoracotomy. This was felt to be a reasonable solution given that patient’s relatively inaccessible deep venous system. It also allowed for the placement of redundant catheter in the thoracic cavity, thereby minimizing the need for revisions due to outgrown catheter. However, we did not have any basis in the literature for deciding whether the azygos vein would serve as an adequate distal site in our adult patient with myelomeningocele-related hydrocephalus.
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As such, we decided that a revision was necessary and elected to first attempt an endovascular revision of the distal catheter’s location. This is one of only 4 reported cases of a successful snare and relocation of a distal catheter via an endovascular technique. In 1972, a
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similar approach was first reported by Dr. McSweeney, who performed this in a 5 year-old boy.13 He describes a misplaced distal VA shunt catheter that was in the left innominate vein near its junction with the vertebral vein and was causing arrhythmias that were noted intraoperatively.
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The child’s femoral vein could not be accessed, so a left saphenous vein cut-down was
performed and a catheter with a deflector was advanced up through the right atrium. The
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vascular access catheter was then hooked around the shunt catheter and pulled down to the intended location. In 2007, Gonzalez et al.,1 described transvenous endovascular manipulation of a shunt catheter, but the technique used was far more invasive. It required open surgical access to and into the internal jugular vein, with a temporary connection made between the transvenously-
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placed distal catheter and the true distal shunt catheter that was intended to remain at the cavoatrial junction. In contrast, the technique we present does not require any open access of the great vessels, which often are scarred and fragile in such complex cases.
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To our knowledge, there are no other reports of endovascular repositioning of a distal VA shunt catheter until 2012. Xu et al.,14 published a case in which intraoperative x-ray taken during
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a VA shunt placement, which was performed by open access to the left facial vein, showed shunt catheter looping within the left internal jugular vein just above the level of the subclavian vein. The authors then accessed the left femoral vein and employed an endovascular loop snare to pull the coiled shunt catheter down into the right atrium. As such, the case we present represents only the fourth report of an endovascular transvenous technique used to revise an intact distal VA shunt catheter.
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A technical disadvantage of this technique is that it does not allow for complete interrogation of the shunt system by manometry, as would be possible with disconnecting the valve, distal catheter and proximal catheter. Surgeons must keep in mind that if the technique we
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describe is employed to address malposition of the catheter, catheter occlusion must still be ruled out if the patient does not improve clinically.
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Conclusions
Distal revision of a VA shunt may be necessary due to a migrated distal catheter, and this
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unique endovascular approach allows for direct snaring and manipulation of the distal catheter
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without open access and handling of the shunt components.
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References 1.
L.F. Gonzalez, L. Kim, H.L. Rekate, C.G. McDougall, F.C. Albuquerque, Endovascular placement of a ventriculoatrial shunt, J Neurosurg Pediatr 106, 2007, 319-321 S.F. Redo, A. Ciccarelli, J. Ghajar, M. Dinner, Ventriculoatrial shunt utilizing the azygos
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2.
vein, J Pediatr Surg 27, 1992, 642-644 3.
S.K. Konar, T.K. Maiti, S.C. Bir, P. Kalakoti, A. Nanda, Robert H. Pudenz (1911–1998)
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and Ventriculoatrial Shunt: Historical Perspective, World Neurosurg 84, 2015, 14371440
R.A. McGovern, K.M. Kelly, A.K. Chan, N.J. Morrissey, G.M. McKhann, Should
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4.
ventriculoatrial shunting be the procedure of choice for normal-pressure hydrocephalus?, J Neurosurg 120, 2014, 1458-1464 5.
B.W. Hanak, R.H. Bonow, C.A. Harris, S.R. Browd, Cerebrospinal Fluid Shunting
6.
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Complications in Children, Pediatr Neurosurg 52, 2017, 381-400 O. Karahan, C. Yavuz, S. Demirtas, A. Caliskan, K. Kamasak, O. Guclu, et al., Reasons, procedures, and outcomes in ventriculoatrial shunts: A single-center experience, Surg
7.
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Neurol Int 4, 2013, 10
T.G. Machinis, K.N. Fountas, J. Hudson, J.S. Robinson, E.C. Troup, Accurate placement
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of the distal end of a ventriculoatrial shunt with the aid of real-time transesophageal
echocardiography, J Neurosurg 105, 2006, 153-156
8.
H.L. Chuang, C.N. Chang, J.C. Hsu, Minimally invasive procedure for ventriculoatrial shunt-combining a percutaneous approach with real-time transesophageal
echocardiogram monitoring: report of six cases, Chang Gung Med J 25, 2002, 62-66 9.
C.A. James, D.R. McFarland, C.J. Wormuth, C.M. Teo, Snare retrieval of migrated ventriculoatrial shunt, Pediatr Radiol 27, 1997, 330-332 9
ACCEPTED MANUSCRIPT Adult myelomeningocele ventriculoatrial shunt revision; endovascular transvenous
10.
A. Surov, G. Koman, C. Behrmann, C. Strauß, M. Kornhuber, A rare cause of ventriculoatrial shunt malfunction, Clin Neurol Neurosurg 111, 2009, 310-311
11.
T. Mori, M. Arisawa, M. Fukuoka, K. Tamura, M. Kurisaka, K. Mori, Management of a
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Broken Atrial Catheter Migrated into the Heart: A Rare Complication of Ventriculoatrial Shunt —Case Report—, Neurol Med Chir (Tokyo) 33, 1993, 713-715 12.
T. Tatsumi, W.J. Howland, Retrieval of a Ventriculoatrial Shunt Catheter from the Heart
W.J. McSweeney, Intravascular repositioning of a ventriculoatrial shunt. Technical note, J Neurosurg 36, 1972, 512-514
14.
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13.
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by a Venous Catheterization Technique, J Neurosurg 32, 1970, 593-596
B. Xu, S. Chotai, K. Yang, W. Feng, G. Zhang, M. Li, et al., Endovascular Intervention for Repositioning the Distal Catheter of Ventriculo-Atrial Shunt, Neurointervention 7,
Figure Caption
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2012, 109
At the patient’s initial presentation, computed tomography (CT) showed overt ventriculomegaly
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(A). After placement of a new left VA shunt with vascular access obtained to the left subclavian vein, post-operative chest x-ray (B) and chest CT (C) showed expected termination of the VA
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shunt at the cavoatrial junction (arrowhead) and not in azygos vein (arrow). At re-presentation, CT showed that the distal shunt catheter had migrated to the azygos vein (D, arrow). After endovascular distal revision for repositioning of the catheter to the cavoatrial junction (E), the patient recovered well. Follow-up CT 1 month later shows smaller ventricular volumes (F).
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HIGHLIGHTS (maximum 85 characters, including spaces, per bullet point). •
Myelomeningocele patients typically have shunt-dependent hydrocephalus
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Ventriculoatrial (VA) shunts: an important option for cerebrospinal fluid
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diversion
Reported is a unique case of distal VA shunt revision via endovascular snare
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This technique allows for minimally invasive VA shunt revision
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Abbreviations computed tomography (CT) ventriculoatrial (VA)
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ventriculoperitoneal (VP)
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Disclosure The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.
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Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
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Acknowledgements
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We wish to thank Shirley McCartney Ph.D. for editorial assistance.