Transvenous Repositioning of a Distal Ventriculoatrial Shunt Catheter Terminating in the Coronary Sinus in a Pediatric Patient With a Duplicated Superior Vena Cava

Abstract

Ventriculoatrial shunts (VAS) are an alternative to ventriculoperitoneal shunts (VPS) for cerebrospinal fluid (CSF) diversion in patients with peritoneal contraindications. Although rare, complications such as catheter migration or malposition can occur and may be exacerbated by underlying congenital venous anomalies. Endovascular techniques have emerged as a minimally invasive option for VAS revision, yet reports remain limited and primarily focus on acquired malpositions. To our knowledge, no prior case describes endovascular VAS repositioning in the context of a duplicated superior vena cava (SVC) with catheter termination in the coronary sinus. In this case, a 15-year-old female patient with a history of congenital hydrocephalus and prior VPS placement underwent conversion to a VAS due to abdominal pseudocyst formation. Chest radiography obtained postoperatively demonstrated an abnormal left-sided venous course of the distal catheter. Subsequent chest CT confirmed traversal of the catheter through a duplicated left SVC with termination in the coronary sinus, risking the development of thromboembolism. To avoid the risks associated with open surgical revision, such as vascular injury, infection, and compromised venous access, an endovascular approach was selected. Using transfemoral venous access and fluoroscopic guidance, the catheter was successfully repositioned from the coronary sinus into the right atrium, with correct positioning confirmed on postoperative chest X-ray. Fluoroscopy time was 11.3 minutes, maximum radiation dose was 24.9 mGy (968.21 µGy/m²), and total procedural time was 28 minutes. The catheter was repositioned within eight minutes of procedure onset. No contrast was used during the procedure, and image guidance was purely with fluoroscopy. The patient had no postoperative complications. During yearly follow-up, the patient remained free of symptoms of shunt malfunction, and surveillance chest radiography confirmed the distal catheter tip within the right atrium. This case highlights the importance of targeted preoperative imaging, as preoperative transthoracic echocardiography (TTE) may fail to identify anomalous thoracic venous anatomy. In such cases, screening chest CT or CT venography may be prudent when anatomical variants are suspected. In addition, endovascular repositioning of malpositioned distal VAS catheters within the venous system may represent a lower-risk alternative to open distal shunt revision in carefully selected patients.

Introduction

The mainstay of hydrocephalus management involves cerebrospinal fluid (CSF) diversion using shunt systems. The ventriculoperitoneal shunt (VPS) is the most commonly used and diverts CSF into the peritoneal cavity [1]. However, complications such as infection, obstruction, and abdominal pseudocyst (APC) formation can necessitate revision or conversion to alternative shunt systems [1,2].

When the peritoneum is unsuitable, a ventriculoatrial shunt (VAS) becomes a viable alternative to VPS, diverting CSF into the right atrium [3]. Despite their effectiveness, VAS placements can result in complications, including catheter migration, malposition, and thromboembolic events [3,4]. These complications may present as shunt malfunctions, with symptoms of hydrocephalus, or with cardiopulmonary complications if the catheter terminates in unintended locations [3]. Revision is most often performed through open surgical correction, although less invasive endovascular repositioning may be considered depending on patient anatomy and prior surgical history [3,4].

Endovascular repositioning of malpositioned VAS catheters has been described in case reports, typically in cases of catheter migration into vessels such as the azygos, innominate, or jugular veins. These procedures commonly use transfemoral venous access, fluoroscopic guidance, and snaring devices to minimize morbidity in patients with complex surgical histories [5-7]. However, these reports generally address acquired or iatrogenic malposition, not congenital vascular anomalies. Despite isolated reports of endovascular repositioning, evidence is limited regarding its role in patients with congenital venous anomalies, where procedural planning, perioperative risks, and postoperative outcomes are less well characterized. Here, we present a novel case, utilizing a minimally invasive technique for managing a shunt catheter terminating in the coronary sinus of a young patient with a duplicated superior vena cava (SVC), an anatomical variant not previously addressed in this context. This anatomical variant is rare, occurring in only 0.3%-0.5% of the population, and can complicate surgical planning [6]. In patients with a duplicated SVC, studies also suggest an increased risk of thrombus formation and impaired growth of the central pulmonary arteries, both of which can negatively affect long-term outcomes [8,9]. In this report, we propose that an endovascular approach may be a safe and less invasive option for shunt revisions in patients with anomalous venous anatomy.

Case presentation

A 15-year-old female patient with congenital hydrocephalus managed with a left-sided VPS due to infection of a prior right-sided VPS presented with constipation and abdominal pain. Non-contrast head CT on admission demonstrated no change from baseline ventricular size. The patient otherwise had no clinical signs of decompensated hydrocephalus. CT abdomen and pelvis demonstrated a loculated abdominopelvic fluid collection consistent with an APC. A percutaneous shunt tap through the valve reservoir with a 25-gauge needle revealed an opening pressure of 12 cmH2O and a brisk distal runoff. The distal catheter was externalized, and after draining the APC, it was connected to an external collection chamber. The decision was made to convert the shunt to an atrial terminus after 10 days of treatment with antibiotics following negative CSF cultures. A preoperative echocardiogram and CT head were performed routinely to evaluate preoperative anatomy and were interpreted as normal. Specifically, there was no change in ventricular size or index in comparison to prior non-failure scans. At our institution, chest CT or MRI is not standard of care for preoperative evaluation in the absence of cardiopulmonary symptoms or known vascular anomalies. The patient was taken for a distal shunt revision and conversion to a VAS. As is standard in our institution, we requested general surgery’s assistance for distal access, given their familiarity and expertise in obtaining central venous access. During surgery, the left internal jugular vein was then accessed using ultrasound guidance with good venous flow post-access. During wire advancement, the midline was not crossed. An angiocatheter was advanced over a wire to obtain confirmation of venous access through manometry, which confirmed venous pressures, and a venous blood gas, which was consistent with venous blood. The distal catheter was then flushed with heparinized saline, advanced, and crossed midline to terminate near the right atrium. Due to the difficulty with distal access intraoperatively and the abnormal appearance of the intraoperative fluoroscopic image of the catheter terminus, cardiology was consulted postoperatively to confirm distal placement. A chest X-ray postoperatively demonstrated the distal catheter projecting over the left side of the heart with the tip in the right atrium (Figure 1). A contrasted chest CT demonstrated a duplicated SVC with the left internal jugular and subclavian veins draining through a shunt in the coronary sinus into the right atrium, and the shunt catheter traversing the left SVC and terminating in the coronary sinus (Figure 2). Notably, there was a left innominate vein with communication between the left and right SVC. After discussion with cardiology, the risk of thrombosis with termination of the shunt within the coronary sinus was deemed too high, and so we elected to revise the shunt.

Figure 1. Postoperative X-ray obtained after VPS-to-VAS conversion showing the distal portion of the VAS coursing through the left-sided SVC with the tip projecting into the right atrium.

VPS: ventriculoperitoneal shunt; VAS: ventriculoatrial shunt; SVC: superior vena cava

Figure 2. Chest CT showing duplicated SVC and distal ventriculoatrial catheter terminating in the left coronary sinus.

SVC: superior vena cava

Endovascular revision of the distal shunt was our preferred approach due to several factors. First, we had low suspicion at the time for any proximal malfunction, as the system was visually confirmed intraoperatively to be functional prior to distal placement. Second, given the difficulty with distal placement during the first surgery, we suspected we would face similar difficulty with distal access and may have to convert to an alternative terminus. Third, an endovascular approach was thought to have lower periprocedural risk compared to open revision due to the lower operative time and invasiveness. Fourth, we opted against a pleural terminus given the risk of pleural effusion, a higher incidence and more poorly tolerated complication in pediatric populations [10]. Our patient was a high producer of CSF, estimated at around 500 cc per day based on daily measured externalized shunt output measurements, further making a pleural terminus an unrealistic option. Fifth, an endoscopic third ventriculostomy (ETV) was thought to be too high-risk for basilar artery injury due to her small prepontine cistern with minimal space between her clivus and brainstem. Lastly, repeated open procedures may cause central venous scarring or thrombosis, jeopardizing future vascular access, a critical issue in young patients likely to require lifelong shunt revisions [5,7,11].

Under general anesthesia, the endovascular procedure began with ultrasound-guided right femoral vein access using the modified Seldinger technique and placement of a 5 F sheath. Utilizing fluoroscopic guidance, with a continuous infusion of heparinized saline, a 5 F USL2 catheter with a 0.035 Glidewire was navigated into the left subclavian vein through the left innominate connection to the right SVC, then shaped appropriately. The USL2 has a moderately stiff Shepard’s hook with which we planned to hook the catheter. The distal shunt catheter, initially positioned in the coronary sinus, was carefully hooked with the USL2 catheter and repositioned through the left innominate vein into the junction of the right subclavian vein and right atrium. This was confirmed with fluoroscopy. The USL2 catheter and sheath were then removed, and hemostasis was achieved with manual compression. Fluoroscopy time was 11.3 minutes, maximum radiation dose was 24.9 mGy (968.21 µGy/m²), and procedural time was 28 minutes. The patient was initiated on aspirin for thromboprophylaxis and has remained on aspirin since.

There were no postoperative complications. A postoperative chest radiograph demonstrated the distal catheter at the junction of the right subclavian and right atrium after transvenous repositioning (Figure 3). Given the absence of preoperative hydrocephalus and clinical stability following treatment of the APC and conversion to a VAS, no routine postoperative head imaging was obtained. Given the normal opening pressure on the initial shunt tap and the stable postoperative clinical exam, surveillance CSF pressure measurements were not performed. The patient was ultimately discharged and has been followed with our clinic with yearly chest radiographs, each documenting termination within the upper right atrium. They have reported no symptoms of shunt malfunction or decompensated hydrocephalus during follow-up. 

Figure 3. Post-endovascular revision shuntogram confirming repositioned distal ventriculoatrial shunt catheter at the junction of the right subclavian and right atrium after transvenous repositioning.

Discussion

VAS offers a reliable alternative for CSF diversion when the peritoneal cavity is no longer viable [5]. However, their use is associated with unique risks, including catheter malposition, thrombosis, and cardiac complications [3,11,12]. The choice of shunt revision strategy depends on the patient’s anatomy, prior surgical history, reason for shunt failure, and the underlying cause of hydrocephalus [11]. VPS and VAS alternatives typically include varying shunt termini, such as ventriculopleural shunts. Alternatively, some patients may be candidates for ETV, which may be considered in cases including aqueductal stenosis, obstructive tumors, obstructive cysts, or patients who outgrow previously placed shunts [13]. The choice of surgical intervention for these patients depends on patient-specific factors that can include the cause of hydrocephalus, age at diagnosis, rate of baseline CSF production, and comorbid conditions limiting surgical options. Furthermore, each procedure requires an open surgical approach and is associated with its own perioperative surgical risks. In contrast, endovascular revision offers a minimally invasive strategy that utilizes vascular access to reposition or replace an otherwise functional distal catheter. Emerging literature suggests this approach can reduce perioperative morbidity, shorten recovery, and preserve venous pathways [14,15]. However, it requires specialized expertise and remains underutilized.

In our patient with a duplicated SVC, an endovascular approach was chosen after careful discussion, as open surgery posed higher risks of infection, morbidity, and central venous scarring that could compromise future access [7,16]. This is especially important in pediatric patients who are likely to require lifelong shunt revisions. In this case, the presence of a duplicated SVC resulted in distal catheter termination in the coronary sinus, a location not previously described in the literature, where reported cases of malposition typically involve the azygos or jugular veins [5,7,17]. Our case adds to this body of knowledge by documenting an unusual termination within the coronary sinus in the setting of a duplicated SVC. To our knowledge, endovascular management of a VAS malpositioned into the coronary sinus, particularly in the presence of a duplicated SVC, has not been previously documented. Recognition of this complication is clinically significant because the coronary sinus is intimately involved in atrial conduction. Intraluminal devices here may increase the risk of arrhythmia and thrombosis, with potential for catastrophic consequences [18]. Like thrombosis in other locations, Virchow’s triad is the mechanism underlying thrombosis in the coronary sinus [19]. The coronary sinus contains muscle fibers with electrical connections to both atria. Dilatation or stimulation of conducting cells of the coronary sinus from a distal catheter can disrupt conduction or trigger premature beats [18]. This can cause arrhythmias and, consequently, venous stasis, promoting thrombus formation [18,19]. Furthermore, mechanical endothelial damage from catheter placement can trigger the coagulation cascade, and flow around the catheter can become turbulent, both of which can also promote thrombus formation [19].

Given the potential for serious cardiac complications associated with unrecognized catheter malposition in this setting, careful imaging evaluation is essential to accurately identify anomalous venous anatomy and guide management. Echocardiography has notable limitations in specific scenarios involving the identification of thoracic venous anatomy. Specifically, SVC anomalies are limited in their characterization by echocardiography due to the poor acoustic window owing to the air-filled lungs and overlying bones [20]. In contrast, CT-and specifically CT venography-provides quick image acquisition with direct enhancement of the systemic venous system, allowing for good spatial resolution [20]. Furthermore, multiplane reconstructions and volume rendering allow for further characterization of anomalous systemic venous anatomy [20]. The justification for selecting an echocardiogram over a CT venogram, particularly in the context of pediatrics, often includes radiation dosing. At our institution, we estimate an average effective dose of 5 to 10 mSv per CT venogram, a substantial dose. However, given our experience above and the diagnostic strength of a CT venogram in comparison to an echocardiogram or venous Doppler, we have changed our practice to include CT venograms. Specifically, we obtain CT venograms in the workup of all patients with multisystem congenital abnormalities, even in the absence of known congenital cardiac abnormalities.

This report is limited by its power, limited long-term follow-up, and the absence of comparative data between endovascular and open revision techniques. As additional cases are reported, further experience may help refine imaging strategies, patient selection, and long-term outcomes associated with endovascular management of distal VAS malposition in patients with anomalous venous anatomy.

Conclusions

This case highlights the importance of recognizing atypical catheter trajectories during VAS placement, as anomalous thoracic venous anatomy may not be readily identified with standard preoperative evaluation. In cases where anomalous venous anatomy is suspected or the catheter trajectory appears atypical, screening chest CT or CT venography may serve as a useful adjunct to echocardiography. Additionally, endovascular repositioning of malpositioned distal VAS catheters within the venous system may represent a lower-risk alternative to open distal shunt revision in carefully selected patients. Future multicenter registries or case series could help define patient selection criteria, procedural safety parameters, and long-term efficacy of endovascular VAS revision in anatomically complex cases.