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CASE REPORT
Repeated shunt dysfunction due to Barium allergy thatwas difficult to differentiate from shunt infection
Asami Kikuchi1, Shigeomi Yokoya2, Hideki Oka2, Hiroshi Ohno3, and Akihiko Hino4
1
Department of Neurosurgery, Tokyo Women’s Medical University Medical Center Adachi, Tokyo, Japan, 2Department of Neurosurgery,
Saiseikai Shiga Hospital, Shiga, Japan, 3Department of Intensive Care Unit, Rakuwakai Otowa Hospital, Kyoto, Japan, 4Department of Neurosurgery, Otsu City Hospital, Shiga, Japan

Abstract : We encountered a case of repeated shunt dysfunction caused by barium allergy. The patient was a60-year-old male who underwent ventricular peritoneal shunting for hydrocephalus following subarachnoid
hemorrhage due to a ruptured aneurysm ; however, it malfunctioned many times. A patch test performed after
the third reconstruction was positive for barium. To the best of our knowledge, this is the first case report ofshunt malfunction due to barium allergy. The patch test is useful in cases of suspected allergy-related dysfunction. We recommend the introduction of barium into antigen testing using the patch test. J. Med. Invest. 70 : 521523, August, 2023
Keywords : Shunt dysfunction, barium allergy, shunt infection, hydrocephalus

INTRODUCTION
Ventricular peritoneal shunting (VPS) is a well-establishedtreatment for hydrocephalus and a basic procedure in neurosurgery. Shunt malfunction may occur for a number of reasons,
sometimes requiring multiple re-shunting procedures, which isburdensome for both the patient and treating physician. Infection is the most common cause of shunt malfunction, and recent
studies described allergic reactions that resulted in aseptic meningitis. Allergic reactions to latex in surgical gloves, ethyleneacid to disinfect instruments, and silicone in shunt devices havebeen reported. (1, 2) However, barium is not known to cause
allergic reactions that lead to meningitis and shunt dysfunction.
We herein present a unique case of hydrocephalus after subarachnoid hemorrhage. Shunt dysfunction developed due to barium allergy, which was difficult to differentiate from infection
due to repeated fever.

CASE REPORTFirst shunting

A 60-year-old man presented with subarachnoid hemorrhage due to a ruptured right anterior communicating arteryaneurysm. He showed World Federation of Neurosurgical Societies grade I. Emergency direct clipping was performed. The
postoperative period was uneventful. On postoperative day 17,impaired consciousness and enlarged ventricles were noted, andthe patient was diagnosed with secondary hydrocephalus. Shuntsurgery was performed. On the third day after shunting, fever
and impaired consciousness developed, and, thus, spinal fluid
was collected from the shunt valve. Cerebrospinal fluid (CSF)
findings were 32768 / mm3 (92.8% polynuclear cells) and 64.5
mg / dl proteins. Since shunt infection was suspected, the shunt

system was removed on the same day.
There was no redness of the wound, dissection, or obvious pus.
CSF and the shunt tube were collected and bacterial cultures
were negative.
Fever quickly resolved after the shunt had been removed, andthe number of cells in CSF decreased to 316 / mm3 on the second
day after its removal. Since impaired consciousness persisted
due to hydrocephalus, a lumbar drain was placed.

Second shunting
After 27 days of postoperative antibiotic therapy, VPS revision
was performed. On the third day after second shunting, feverand impaired consciousness developed and, thus, spinal fluid
was collected, which showed an elevated cell count of 5400 / mm3(68.5% polynuclear cells) and 88.2 mg / dl proteins. Since re-infection of the shunt was suspected, it was removed on the same day.
There was no redness of the wound, dissection, or obvious pus.
Bacterial cultures of the spinal fluid and shunt tube collected atthat time were negative.
Fever quickly resolved after shunt removal. The day after
shunt removal, an MRI scan of the head showed high-signal
DWI deposits in the bilateral ventricles. (Fig. 1) Since infection was suspected, endoscopic irrigation of the ventricle wasperformed. However, all fungal antibody and CSF culture tests
conducted during this period were negative.

Received for publication February 2, 2023 ; accepted August 1, 2023.
Address correspondence and reprint requests to Asami Kikuchi, M.D.,
Department of Neurosurgery, Tokyo Women’s Medical University
Medical Center Adachi, 4-33-1 Kouhoku, Adachi-ku, Tokyo 123-8558,
Japan and Fax : ++81-3-6807-1956. E-mail : kikuchi.asami@twmu.
ac.jp

Figure 1. Neuroimaging findings in the present case. MRI shows

high-signal deposits (arrows) in the bilateral ventricles on axial (A)FLAIR and axial (B) DWI images.

The Journal of Medical Investigation Vol. 70 2023

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A. Kikuchi, et al. Repeated shunt dysfunction due to barium allergy

Third shunting
Seventy-four days after the removal of the second shunt,
lumboperitoneal shunting (LPS) was performed. Approximately
5 hours after surgery, fever of 38°C developed. The day aftersurgery, fever persisted and impaired consciousness was observed ; therefore, spinal fluid was extracted from the valve,
which showed a high cell count of 3100 / mm3 (71% polynuclearcells) and 125 mg / dl proteins. We removed the LPS and feverrapidly resolved.

Fourth shunting
Since bacterial culture tests had been negative and the time
until the onset of fever decreased following shunting each time,
we concluded that infection was not the cause of shunt dysfunction. The recurrence of meningitis or ventriculitis was unlikely
in this short time period ; therefore, an allergic reaction to theshunt tube was suspected.
A skin patch test was performed on the shunt tube containingsilicone, and although there was an irritant reaction, it wasnegative each time according to the International Contact Dermatitis Research Group criteria. A patch test using the shunttube containing a small amount of silicone in addition to barium
showed a positive reaction, leading to a diagnosis of shunt dysfunction due to barium allergy. A barium-free shunt catheter(Translucent Catheter, Japan Medtronic) was used and VPS wasperformed. The patient was transferred to a rehabilitation hospital 207 days after the initial surgery. Shunt dysfunction has notoccurred in the 7 years since surgery.

DISCUSSION
We encountered a case of barium allergy, which was difficult
to differentiate from shunt infection, as a cause of repeatedshunt dysfunction. In the present case, after the shunt tube wasimplanted, the patient repeatedly developed fever and impaired
consciousness ; however, there were no findings to indicate
inflammation, such as redness and tenderness, or an allergic
reaction, including a skin rash and pruritus, on the skin where
the shunt tube ran, which suggested shunt infection. Various
cultures were negative and aseptic meningitis was suspected,
with fever developing more rapidly after surgery, which prompted us to suspect allergy. The course of clinical symptoms isshown in Fig. 2.
The results of the present case suggest barium allergy as acause of shunt dysfunction. To the best of our knowledge, thisis the first case report of barium allergy in VPS. Barium is arelatively safe and versatile substance that is mainly used as agastrointestinal contrast agent. The most frequently reported
area of barium complications is gastrointestinal barium angiography, with reports of barium infiltrating the mucosa of thevenous plexus and causing a state of shock. (3)In the field of neurosurgery, there have also been case reportsof shunt dysfunction caused by barium in pediatric shunts. In
some cases, barium sulfate in the shunt catheter calcified overtime, causing it to tear. (4, 5) Therefore, the Translucent catheter (Medtronic Japan), which contains only a small amount ofbarium sulfate, is now available. This catheter was used in thepresent case.
Previous studies reported latex allergy (1) and silicone allergy(2) as causes of shunt dysfunction and aseptic meningitis. An
increase in eosinophils in CSF or a granulomatous reaction wasFigure 2. Changes in the cerebrospinal fluid (CSF) cell count andprotein levels. Triangles indicate the number of cells. Circles indicate
protein levels in spinal fluid. Large arrows on the graph indicate
revision surgeries for ventricular peritoneal shunting (VPS) andlumboperitoneal shunting (LPS).

identified as a cause of the obstruction ; however, it was also
noted that the former may not occur in some cases. Although
an increase in CSF eosinophils was not observed in the presentcase, the cell count (polynuclear cell predominance) was clearlyelevated. Since the patch test was positive, it is clear that ourpatient had a delayed allergic reaction.
It is also possible that the patient became “sensitized” after
the first and second shunts, and that the third shunt caused astronger and immediate allergic reaction.
Inflammatory precipitates from aseptic meningitis have beensuggested to obstruct the shunt catheter after the valve. (2).
Another study reported more protein deposits on the occluded
catheter surface and higher levels of autoantibodies to proteinsdeposited on the shunt surface. (6) These findings suggest an immunological response to antigens present on the shunt surface,which may play an important role in shunt dysfunction.
We were unable to distinguish whether the immunologicalchanges observed in the present case were directly induced bybarium allergy or inflammatory changes due to aseptic meningitis ; therefore, we attributed the deposits in the ventricles toeither of these factors.
The results of the present case also showed the utility ofa patch test to identify allergy. Furthermore, it is useful toperform a patch test using barium as the suspected drug. The
introduction of barium as an antigenic specimen in the patch
test is recommended. Barium has been used universally in thegastrointestinal field for many years as a substance that is safe
for living organisms. It is a component of shunt tubing, albeit insmall quantities, and an indispensable material for ensuring
X-ray impermeability.
In addition to silicone and barium, other materials for catheter tubing include stainless steel, tantalum, polypropylene, andpolytetrafluoroethylene (PTFE). Stainless steel and tantalum
do not remain in the body. Polypropylene is less allergenic andPTFE is used to reduce allergenicity, neither of which are causative suspects for allergy. Therefore, we suggest the preferential
introduction of barium as a suspect substance.

CONCLUSION
When a patient develops aseptic meningitis after shuntingThe Journal of Medical Investigation Vol. 70 August 2023
surgery, as in the present case, allergic reactions need to be suspected, and if silicone or latex is ruled out, barium needs to beconsidered in the early diagnosis.
2.

CONFLICT OF INTEREST DISCLOSURE
The authors have no personal or institutional interests in thedrugs, materials, or devices described in this manuscript.

ACKNOWLEDGMENTS

3.

4.

The authors are thankful to Dr. Mikhail Chernov and Dr.
Sumiko Ishizaki for their help during the preparation of thismanuscript for publication.

5.

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