Ventriculoperitoneal shunt tube migration into the heart and pulmonary artery: successful tube removal. Illustrative case

Abstract

BACKGROUND

Ventriculoperitoneal (VP) shunt tube migration is recognized as an occasional complication; however, migration into the cardiac system is rare. The authors report a case of VP shunt tube migration into the heart and pulmonary artery and the safe removal of the tube.

OBSERVATIONS

The patient had a VP shunt implanted for hydrocephalus after a subarachnoid hemorrhage. The screening chest radiograph taken a few months later showed the migration of the abdominal tube into the heart. Examinations revealed that the abdominal tube had migrated from the left subclavian vein, passed through the superior vena cava, right atrium and ventricle, and looped into the pulmonary artery. The patient had no symptoms; however, there were some risks, such as damage to the valves or fatal arrhythmia. The authors therefore decided to remove the tube. To avoid various intraoperative risks, in particular tube knot formation, the tube was removed under fluoroscopy with a guidewire inserted, which was 0.035 inches for the angiography catheter. The tube was successfully removed without any complications.

LESSONS

Knot formation can be one of the fatal complications of shunt tube removal. The authors’ technique is an effective method for safe removal.

https://thejns.org/doi/10.3171/CASE24127

Ventriculoperitoneal (VP) shunting is one of the methods of treatment for hydrocephalus. However, this procedure is associated with several complications, including infection, shunt obstruction, peritonitis, and shunt tube migration. While there have been many reports of shunt tube migration, migration into the cardiac system is rare. We report this rare complication of VP shunting and discuss its safe recovery.

Illustrative Case

A 48-year-old woman was treated for communicating posthemorrhagic hydrocephalus after a subarachnoid hemorrhage, and a VP shunt (CODMAN CERTAS, Integra Japan Co.) was implanted approximately 5 months previously. One month after shunt implantation, a computed tomography (CT) scan of the head, chest, and abdomen showed that the shunt tube was properly positioned. The screening chest radiograph showed that the abdominal tube had migrated into the heart (Fig. 1).

FIG. 1.

Chest radiograph (A) and CT (B) obtained the day after the shunt operation, showing that the shunt tube (white asterisk) was in the correct position, away from the jugular vein (white arrowheads) and the subclavian vein (white arrows). Chest radiograph obtained 5 months after the operation (C), showing that the tube had migrated into the heart (white arrowheads). To make the tube easier to see, the color has been inverted and the window level adjusted.

A CT scan of the head showed that the position of the ventricular tube was correct; however, a CT of the chest showed that the abdominal tube had migrated from the left subclavian vein, passed through the superior vena cava, right atrium and ventricle, and looped into the pulmonary artery in a loop (Fig. 2).

FIG. 2.

The cardiac gated chest CT showed that the abdominal tube migrated from the left subclavian vein (A), passed through the superior vena cava, right atrium and ventricle, and ended in a loop in the pulmonary artery (B).

The intracardiac foreign body could cause fatal arrhythmia or damage to the heart valves;¹ therefore, we decided to remove the shunt system. First, to determine whether the shunt system could be removed, the shunt pressure was set to Setting 8 (> 400 mm H₂O), which is pseudo-occlusion. The patient had no new symptoms or progression of hydrocephalus on head CT.

We discussed potential risks and countermeasures. A review of past cases showed that there were instances in which the shunt tube formed a knot when being removed.² A knot could block the valve, causing cardiac arrest. We decided to use a guidewire for cerebral angiography to prevent knot formation.

The surgery was performed in collaboration with cardiovascular surgery, radiology, and anesthesiology teams. The surgical strategies and procedures were as follows. 1) A skin incision was made on the left side of the neck, where the tube position was confirmed by echogram. 2) The shunt tube was cut, the abdominal tube was secured, and the ventricular tube was double ligated. Due to the risk of bleeding during removal, the ventricular tube was not removed. 3) A 0.035-inch guidewire for angiography (150 cm, Radiofocus guidewire, Terumo Co.) was inserted into the abdominal tube under fluoroscopic guidance. 4) When the guidewire reached the right ventricle, the catheter spontaneously dropped from the pulmonary artery into the ventricle. At the same time, the tube loop was released (Fig. 3). 5) The tube was removed from the left subclavian vein. The retrograde contrast from the left forearm vein confirmed no blood leakage.

FIG. 3.

The tube is located at the pulmonary artery (A). When the guidewire reaches the right ventricle, the tube drops into the ventricle (B), and at the same time, the loop is released (C).

There were neither postoperative complications nor progression of hydrocephalus. More than 1 year has passed, and the patient has no symptoms caused by hydrocephalus.

Patient Informed Consent

The necessary patient informed consent was obtained in this study.

Discussion

VP shunts have a variety of complications. Adib et al. reported 28 cases of shunt tube migration into the heart, including their own case, but this complication is very rare.² If the shunt tube migrates into the cardiac system, cardiopulmonary complications such as arrhythmia or cardiac tamponade can occur, with fatal consequences.¹ Therefore, surgical or endovascular removal of the shunt tube should be considered.

Observations

In our case, the most serious complication of the removal procedure was the knotting of the tube, which could lead to fatal valve incarceration. In fact, it has been reported that knot formation has been observed during the removal of the tube.² The reason for the tendency to knot may be that the tubing is made of soft silicone. To prevent knotting, the tube must have adequate rigidity. The stiffener must be of sufficient hardness and must not damage the tube. In our case, the knotting was prevented by inserting a guidewire into the tube. This is the first reported case. The guidewire for angiography has moderate hardness and a soft tip, which has a low risk of damaging the tube. The diameter of the guidewire used in this case was 0.89 mm (0.035 inches), which was slightly too small for the abdominal tube (1.0 mm). It is important to check the diameter of the tube and select an appropriate guidewire size. The use of a guidewire is a very effective and safe method of preventing knot formation during tube removal.

There are some reports about the methods of tube removal.^{3, 4} In some patients, the migrated tube was simply removed without any countermeasure. Some used a snare catheter or pigtail catheter for endovascular treatment. If the tube is ruptured, endovascular methods could be useful.

In addition, various risks were considered, and countermeasures were planned during removal (Table 1). The procedure was performed under fluoroscopic guidance to check for knot formation. In view of the possibility of cardiac injury, preparations were made for open-heart surgery, and cardiovascular surgeons were on standby. Interventional radiologists also were on standby for tube breakage. In addition, the anesthesiologists used transesophageal echography and electrocardiography to monitor for fatal arrhythmia, valve damage, and pulmonary artery embolism from the tube.

TABLE 1.

Intraoperative possible risks and countermeasures for them

Possible Risk	Countermeasure
Transition to open surgery	Cardiovascular surgeons stand by
Shunt tube breakage	IVR specialists stand by
Deadly arrhythmia	ECG monitoring
Heart valve damage	Transesophageal echocardiography
Pulmonary embolization	Cardiac echogram & vital monitoring
Shunt tube knot formation	Under fluoroscopic guidance

ECG = electrocardiogram; IVR = interventional radiotherapy.

There are several possible causes of shunt tube migration. One possibility is that the subclavian vein was punctured when the subcutaneous tunnel was created during the VP shunt procedure.^{4, 5} The other possibility is that the shunt tube and vein were in close proximity, and prolonged friction caused the shunt tube to migrate into the vessel beyond the vessel wall.^{5, 6} During the creation of the subcutaneous tunnel in our shunt procedure, there was no abnormal bleeding from the subclavian or cervical area, and there was no obvious evidence of venous injury.

However, postoperative chest CT showed that the tube was away from both the subclavian vein and the jugular vein, making it unlikely that gradual migration occurred due to the proximity and persistent friction of the tube to the vessel. More likely, the tube penetrated a small vein that drains into the subclavian vein, which may have caused the tube to migrate into the vein.

Therefore, to prevent the shunt tube from migrating into the blood vessel, care must be taken not to damage the vein when creating the subcutaneous tunnel. In addition, postoperative images by CT, as well as radiography and follow-up imaging over time, may be required.

There are several limitations. First, the exact mechanism by which the tube migrated cannot be determined. Therefore, it is not possible to suggest a way to prevent it. However, we should pay attention to any unexpected bleeding observed during the creation of the tube tunnel.

Second, it is unclear when the tube migrated. The tube was found to be in the correct position on the day after surgery, but then there were no follow-up images until 5 months later when the migration was found.

Lessons

We have reported a case in which the abdominal tube of a VP shunt migrated into the cardiac system. In such a case, the migrated tube should be removed to avoid fatal complications. When removing the tube, it is important to be prepared for various risks. In addition, although knot formation is one of the most serious complications, the use of a guidewire is the most effective and safest method of removing the tube.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: Yamada, Tokuda, Yokoyama. Acquisition of data: Tokuda, Yokoyama. Analysis and interpretation of data: Tokuda. Drafting the article: Tokuda. Critically revising the article: Yamada, Tokuda. Reviewed submitted version of manuscript: Yamada, Tokuda, Nakagawa. Approved the final version of the manuscript on behalf of all authors: Yamada. Statistical analysis: Tokuda. Administrative/technical/material support: Tokuda. Study supervision: Yamada, Tokuda, Nakagawa.

Correspondence

Shuichi Yamada: Nara Medical University, Kashihara-city, Nara, Japan. syamada@naramed-u.ac.jp.