Keywords
Ventriculoatrial shunt - ventriculoperitoneal shunt - hydrocephalus
Introduction
The ventriculoatrial shunt (VAS) was first introduced by Nulsen and Spitz in 1952. With the contribution of Pudentz in the evolution of the shunt valve, the VAS became popular for the treatment of hydrocephalus until the 1970s. However, long-term severe cardiac and renal complications have been reported, such as complications associated with tricuspid lesions, endocarditis, thrombosis, the catheter traversing the foramen ovale, and pulmonary hypertension.[1]
[2] In previous reports, shunt removal by sternotomy was recommended for the treatment of these complications, while an endovascular approach is common for the removal of a broken VAS catheter.[1]
[3]
[4] Thus, the VAS was established as an alternative treatment when the other options were not feasible. In recent years, however, some have reported that the VAS should be considered the treatment of choice for hydrocephalus in older patients, because in their studies, patients with VAS were less likely to experience shunt obstruction than those with VPS.[5] Accordingly, we are more likely to encounter older patients with VAS. There are no previous reports of the simple removal of VAS without any specialized techniques or equipment with simultaneous shunt revision using VPS. In the present case, we report a patient who underwent simple removal of the VAS and simultaneous VPS revision without any shunt-related cardiac complications.
Case Presentation
An 87-year-old, otherwise healthy female, had undergone implantation of a VPS for the treatment of idiopathic normal pressure hydrocephalus 6 years prior. She developed mild chronic subdural hematoma through overdrainage, but neither revision nor evacuation of hematoma was performed. She presented with left hemiparesis and was transferred to our hospital, and right thalamic hemorrhage with intraventricular hemorrhage was diagnosed. One month after admission, head CT scan revealed the hematoma had resolved with ventriculomegaly ([Figs. 1] A, B). Transthoracic echocardiography (TTE) demonstrated no obvious cardiac complications. The reservoir of the VAS would not pump up after it was pushed in, suggesting malfunction of the shunt system, especially on the cranial side. She underwent VAS removal by patching of the internal jugular vein with fascia, and a VPS was performed simultaneously as per the usual procedure in our institution ([Fig. 2]). She remains well with no evidence of complications on postoperative day 10. The patient has provided informed consent for publication of the case.
Fig. 1 Preoperative axial CT scan (A) on admission; (B) 1 month after admission, indicating a recurrence of hydrocephalus.
Fig. 2 Intraoperative photographs of the internal jugular vein at the insertion site of the shunt catheter (white arrowhead).
Discussion
The removal of a long-term implanted VAS is not recommended, because of the possibility of severe adhesion to the right atrium or formation of an intracardiac thrombus.[6]
[7] Our review of the literature identified only three cases of simultaneous VAS removal and VPS revision in adulthood ([Table 1]).[2]
[4]
[7] The articles were identified via a PubMed search using the keywords “ventriculoatrial shunt,” “complications,” and “shunt revision,” alone and in combination. In two of the three cases, the VAS removal was achieved through sternotomy, and the revision was performed several days later.[2]
[7] The third case underwent endovascular treatment, wherein the distal catheter was removed intravenously, and then the remaining shunt system was connected to a new peritoneal catheter; this does not constitute simple removal.[4] Natarajan et al recommend follow-up using TTE for patients who had undergone VAS implantation more than 10 years ago.[8] Paradini-Santos et al reviewed reports of VAS complications and suggested that, if the catheter has only recently been inserted, simple traction on the distal catheter may be sufficient for removal.[1] These reports suggest that if there are no obvious VAS-related complications identified on TTE, safe removal of the VAS is possible.
Table 1
Summary of previous case reports on surgery for complication of VAS
|
Author (year)
|
Age
|
Sex
|
Complication
|
Treatment
|
Revision
|
|
Abbreviations: F, female; M, male; IJV, internal jugular vein; VAS, ventriculoatrial shunt; VPS, ventriculoperitoneal shunt.
|
|
Cowan and Allen2
|
52
|
M
|
Retrograde cardiac migration
|
Ligation of IJV
|
VAS on the contralateral side
|
|
Tonn et al4
|
26
|
F
|
Pulmonary embolism
|
Endovascular
|
VPS
|
|
Gopal and Peethambaran7
|
41
|
M
|
Endocarditis
|
Sternotomy
|
VAS
|
According to Alvi et al, VAS accounted for 0.95% (n = 130) of all shunting procedures in patients over 60 years of age from 2007 to 2017.[9] In recent years, however, there have been more reports that there is no difference in long-term complications between VPS and VAS in older patients. Rymarczuk et al reported that the most common etiology of shunt malfunction is proximal catheter failure,[10] and Paradini-Santos et al reported that the most common complications of shunt malfunction were shunt obstruction or disconnection.[1] In other words, the number of cases in which removal and replacement are necessary without VAS-related complications is expected to increase. The present study, based on these reports, demonstrated the safe removal of VAS with only basic hemostasis via pressure on the fascia of the internal jugular vein at the distal catheter insertion site and the usual revision of the VPS.
Conclusion
We reported that VAS removal in patients without VAS-related cardiac complications could be performed without specialized techniques and that simultaneous VPS was possible.
