Keywords
ventriculoatrial shunt - Seldinger technique - distal end
Introduction
The commonly used cerebrospinal fluid (CSF) diversion procedures are ventriculoperitoneal
(VP) shunt, ventriculoatrial (VA) shunt, and ventriculopleural (VPL) shunt. VP shunt
malfunctions could be due to various reasons and one of them could be the peritoneum
inability to absorb the CSF.[1] It is particularly the case when tuberculosis affecting the peritoneal absorptive
capability.[2] In such cases, the most preferred alternative is VA shunt compared with VPL shunt.[3] VA shunt is not so often performed procedure. At authors institute, annual neurosurgical
procedures are around 3,500 and VA shunts constitute hardly one or two among them.
The technique of the procedure is always a matter of the concern when it is required.
The authors in the current article describe the modification in the Seldinger technique
for the placement of VA shunt they adopted in a case of recurrent VP shunt failure
for a case of hydrocephalus as a sequalae to the tuberculosis. The ventricular end
placement is same as for any other shunt placements, while the insertion of the shunt
into right atrium (RA) part could be done minimally invasively using Seldinger technique.
The authors described the modification in technique and the specific tools required
for insertion of the atrial catheter in the current report.
Clinical Details
The patient is a 22-year-old male who is a known case of tubercular meningitis with
hydrocephalus underwent VP shunt (Chhabra shunt, Surgiwear, Shahjahanpur, Uttar Pradesh,
India)2 years back. He had multiple abdominal end revisions 6 months back. Twice the
shunt was placed in different parts of the peritoneum on the right side and finally
it was placed on the left side of the abdomen. He had multiple admissions for shunt
revisions. Lastly, he presented to emergency services with altered sensorium. Computed
tomography (CT) brain showed ventriculomegaly, shunt chamber was refilling, and abdominal
ultrasound scan showed CSF collection in the peritoneal cavity. Shunt abdominal end
was exteriorized, and CSF was drained for few days. Patient regained consciousness
and CSF analysis showed no meningitis. In view of the multiple abdominal end revisions
and diminished capacity of the peritoneum to absorb CSF because of possible tuberculous
abdomen, it was decided to place a VA shunt.
Technique
The patient was planned for right VA shunt. The patient is positioned in Trendelenburg
position (10–15°) under general anesthesia. After thorough preparation, the ventricles
were tapped and ventricular catheter (Chhabra shunt, Surgiwear, India) placed and
connected to the distal catheter with chamber. The right internal jugular vein (IJV)
was punctured percutaneously using introducer needle (18G, 7cm) using standard anatomical
landmarks. The guide wire (0.965 mm × 70 cm) was passed into the needle up to T6-T7
vertebral level under fluoroscopy guidance with a close monitoring of electrocardiogram
for any arrhythmias. A stab wound was made for entry of the serial dilators of size
10 F &12 F. The introducer needle was removed keeping the guide in situ. The subcutaneous
track was serially dilated using the hemodialysis catheter dilators from the hemodialysis
catheter set (Mahurkar Acute dual lumen catheter kit, Covidien, Mansfield, Massachusetts,
United States) ([Fig. 1]) passing them on the guide wire and a track is made for the passage of shunt catheter.
The dilator is removed keeping the guide wire in situ. The distal ventricular catheter
is brought through the same stab wound made for venous puncture and the tube is cut
measuring the approximate length up to the T6 vertebral level. The distal cut tube
is guided into the IJV over the guide wire after cutting the tip of the tube and the
guide wire removed ([Fig. 2]). The two cut ends of the catheter are connected using the connector and secured
with a 2’0 silk. Compression padding applied over the neck. Patient made an uneventful
recovery. Postoperatively, the catheter tip position was confirmed by the chest X-ray
and CT scan brain and patient discharged on day 3.
Fig. 1 Serial dilators and track dilatation using them.
Fig. 2 Distal catheter insertion over the the guide wire.
Discussion
If we look back into the history of neurosurgical procedures, no other technique would
have probably underwent so many changes than that of a CSF diversion technique. The
idea of VA shunt was suggested by Gartner[4] in the form of CSF diversion into venous or lymphatic system of neck a decade earlier
than the first VP shunt by Kausch in 1905. Animal experiments by Pudenz demonstrated
that the placement of distal tip of the catheter in IJV or superior vena cava can
cause fibrous capsule formation at tip with blockage of tip of the catheter and occlusion
of vein.[5] Thus, the placement of catheter tip at RA had been standardized. Later in the year
1957 Pudenz introduced the VA shunt technique.[6] To access the RA, although various routes like through external jugular vein, transverse
sinus, or subclavian vein[7] had been described, IJV had been the choice for many surgeons due to relatively
less number of complications.
To get the access to the RA, Seldinger technique could be used that makes the procedure
less risky and easily adoptable considering the fact that it is rarely done procedure.
The authors in the present condition took the help of anesthesia colleagues who perform
IJV punctures on routine basis to place central venous lines.
The percutaneous technique for the placement of VA shunt was first described by Sorge
et al[8] using a special set based on the Seldinger technique and there are other reports
that describe this technique.[7]
[9]
[10] Each of these papers described the locally available various catheters and peel
away sheaths to cannulate the IJV or subclavian vein for passing the distal end of
the shunt into the superior vena cava.
The authors in the present paper describe a novel percutaneous technique of VA shunt
placement with use of various serial dilators, cathters and other tools required.
The dilator (Mahurkar acute dual lumen catheter kit, Covidien, Mansfield, Massachusetts,
United States) used by the author has a serial dilator of 10 and 12 F. The distal
catheter of the shunt catheter (Chhabra shunt, Surgiwear, India) has an outer diameter
of 7.5 F size. The tip of the distal end of the Chhabra shunt was cut in our case
to be able to pass it over the guide wire. The other alternative that exists is the
hemodialysis catheter dilators (Mahurkar Chronic Carbothane catheter kit, Covidien,
Mansfield, Massachusetts, United States) or other central line catheter dilators of
similar make that can be available in various sizes of 12, 14, or 16F. These catheter
sets have a peel away sheath that permits the shunt distal end to pass into the IJV
lot easier. The Mahurkar catheter is a cost-effective option but requires cutting
of the shunt tip and manipulation of the shunt tube over the guide wire. These modifications
in the technique proposed by the authors and tools that are available in the Indian
market make the technique lot easier and simpler to perform.
Conclusion
VA shunt is a rarely performed procedure, and application of Seldinger technique using
the serial dilators to pass the distal catheter to the RA makes the procedure simple
and easily adaptable.
