Risk factors for unchanged ventricles during pediatric shunt malfunction

OBJECTIVE Children whose ventricles do not change during shunt malfunction present a diagnostic dilemma. This study was performed to identify risk factors for unchanged ventricular size at shunt malfunction. METHODS This retrospective 1:1 age-matched case-control study identified children with shunted hydrocephalus who underwent shunt revision with intraoperative evidence of malfunction at one of the three participating institutions from 1997 to 2019. Cases were defined as patients with a change of < 0.05 in the frontal–occipital horn ratio (FOR) between malfunction and baseline, and controls included patients with FOR changes ≥ 0.05. The presence of infection, abdominal pseudocyst, pseudomeningocele, or wound drainage and lack of baseline cranial imaging at the time of malfunction warranted exclusion. RESULTS Of 450 included patients, 60% were male, 73% were Caucasian, and 67% had an occipital shunt. The median age was 4.3 (IQR 0.97–9.21) years at malfunction. On univariable analysis, unchanged ventricles at malfunction were associated with a frontal shunt (41% vs 28%, p < 0.001), programmable valve (17% vs 9%, p = 0.011), nonsiphoning shunt (85% vs 66%, p < 0.001), larger baseline FOR (0.44 ± 0.12 vs 0.38 ± 0.11, p < 0.001), no prior shunt infection (87% vs 76%, p = 0.003), and no prior shunt revisions (68% vs 52%, p < 0.001). On multivariable analysis with collinear variables removed, patients with a frontal shunt (OR 1.67, 95% CI 1.08–2.70, p = 0.037), programmable valve (OR 2.63, 95% CI 1.32–5.26, p = 0.007), nonsiphoning shunt at malfunction (OR 2.76, 95% CI 1.63–4.67, p < 0.001), larger baseline FOR (OR 3.13, 95% CI 2.21–4.43, p < 0.001), and no prior shunt infection (OR 2.34, 95% CI 1.27–4.30, p = 0.007) were more likely to have unchanged ventricles at malfunction. CONCLUSIONS In a multicenter cohort of children with shunt malfunction, those with a frontal shunt, programmable valve, nonsiphoning shunt, baseline large ventricles, and no prior shunt infection were more likely than others to have unchanged ventricles at shunt failure.

Development and implementation of an ultralow-dose CT protocol for the assessment of cerebrospinal shunts in adult hydrocephalus

Background Cerebrospinal fluid shunts in the treatment of hydrocephalus, although associated with clinical benefit, have a high failure rate with repeat computed tomography (CT) imaging resulting in a substantial cumulative radiation dose. Therefore, we sought to develop a whole-body ultralow-dose (ULD) CT protocol for the investigation of shunt malfunction and compare it with the reference standard, plain radiographic shunt series (PRSS). Methods Following ethical approval, using an anthropomorphic phantom and a human cadaveric ventriculoperitoneal shunt model, a whole-body ULD-CT protocol incorporating two iterative reconstruction (IR) algorithms, pure IR and hybrid IR, including 60% filtered back projection and 40% IR was evaluated in 18 adult patients post new shunt implantation or where shunt malfunction was suspected. Effective dose (ED) and image quality were analysed. Results ULD-CT permitted a 36% radiation dose reduction (median ED 0.16 mSv, range 0.07–0.17, versus 0.25 mSv (0.06–1.69 mSv) for PRSS (p = 0.002). Shunt visualisation in the thoracoabdominal cavities was improved with ULD-CT with pure IR (p = 0.004 and p = 0.031, respectively) and, in contrast to PRSS, permitted visualisation of the entire shunt course (p < 0.001), the distal shunt entry point and location of the shunt tip in all cases. For shunt complications, ULD-CT had a perfect specificity. False positives (3/22, 13.6%) were observed with PRSS. Conclusions At a significantly reduced radiation dose, whole body ULD-CT with pure IR demonstrated diagnostic superiority over PRSS in the evaluation of cerebrospinal fluid shunt malfunction.

Experience With Ventriculoperitoneal and Lumboperitoneal Shunting for the Treatment of Idiopathic Intracranial Hypertension: A Single Institution Series

BACKGROUND CSF shunting is among the most widely utilized interventions in patients with idiopathic intracranial hypertension (IIH). Ventriculoperitoneal shunting (VPS) and lumboperitoneal shunting (LPS) are 2 possible treatment modalities. OBJECTIVE To evaluate and compare complications, malfunction, infection, and revision rates associated with VPS compared to LPS. METHODS Electronic medical records were reviewed to identify baseline and treatment characteristics for patients diagnosed with IIH treated with VPS or LPS. RESULTS A total of 163 patients treated with either VPS (74.2%) or LPS (25.8%) were identified. The mean follow-up was 35 mo. Shunt revision was required in 40.9% of patients. There was a nonsignificant higher rate of revision with LPS (52.4%) than VPS (36.4%, P = .07). In multivariate analysis, increasing patient age was associated with higher odds of shunt revision (P = .04). LPS had higher odds of shunt revision, yet this association was not significant (P = .06). Shunt malfunction was the main indication for revision occurring in 32.7%, with a significantly higher rate with LPS than VPS (P = .03). In total, 15 patients had shunt infection (9.4% VPS vs 12.2% LPS P = .50). The only significant predictor of procedural infection was the increasing number of revisions (P = .02). CONCLUSION The incidence of shunt revision was 40.9%, with increasing patient age as the sole predictor of shunt revision. The incidence of shunt malfunction was significantly higher in patients undergoing LPS, while there was no significant difference in the incidence of shunt infection between the 2 modalities.

Shunt malfunction and endoscopy

Objective: Hydrocephalus is the most common neurological disease in pediatric neurosurgery.(1) The CSF shunts remains as the most common treatment choice for nonobstructive hydrocephalus worldwide, but shunt complications still the most common neurosurgical problem, especially in pediatric neurosurgery. Endoscopy and shunts are the way to treat hydrocephalus. Especially third ventriculostomy is the most effective treatment to obstructive hydrocephalus but shunt still the most important way to treat.(2, 3) Shunt malfunction is frequent and after so many years this is very important problem to the patients. Ventricular problem due to obstruction is responsible up to 72% of shunt problems.(4) The Shunt Trial Study showed that the overall shunt survival was 62% at 1 year, 52% at 2 years, 46% at 3 years, 41% at 4 years. The survival curves for the 3 differents valves were similar to those from the original trial and did not show a survival advantage for any particular valve.(5, 6) We still don´t have one perfect solution to hydrocephalus and shunt malfunction. The major author described his experience in use endoscopy to evaluate and treat shunt malfunction and one new approach and way to evaluate this problem. Results/Discussion: The literature review was performed, and we found 84 articles when we used the keywords. Endoscopy has been one important way to treat and solve shunt problems. In obstructive hydrocephalus third ventriculostomy is the best way to treat these patients.(1-3) The major author first described goals of endoscopy. First goal is safe catheter removal in surgical review, avoiding bleeding when removing catheter addressing all the adhesions on catheter. Second goal is put in optimal position the new catheter with pure endoscopy view or using neuronavigation systems that could help the endoscope system.(7, 8) Optimal new catheter placement and optimal long-term catheter survival are especially important because most of the problems are due to ventricular problems. These good placements could avoid loculations and ventricular collapse with ependymal problems. Avoid new catheter malpositiitioning, you can use the endoscope to follow the old tract to insert the new catheter in one good position avoiding choroid plexus. Another situation is when you have small ventricles especially in slit ventricle syndrome. The major author has been studied some causes to ventricular catheter obstruction. He noticed after some surgical reviews some ventricular ependymal inside catheter. Ventricular ependymal protrusions inside the catheter could cause intermittent occlusion.(8) Some endoscope views showed these protrusion and ependymal changes after intermittent increase and decrease of ventricular pressure. These protrusions correspond to catheter holes a secondary to suction. These protrusions could stuck in the holes in chronicle suction.(8) The major author reported one endoscopic evidence of overdrainage-related ventricular tissue protrusions that cause partial or complete obstruction of the ventricular catheter. He did a retrospective review in fifty patients underwent 83 endoscopic shunt revision procedures that revealed in-growth of ventricular wall tissue into the catheter tip orifices (ependymal bands), producing partial, complete, or intermittent shunt obstructions. Endoscopic ventricular explorations revealed ependymal bands at various stages of development, which appear to form secondarily to siphoning.(8) How to minimize this overshunting? Anti siphon systems could help and decrease proximal shunt malfunction in some complex patients. The other problem is ventricular bleeding. The use of endoscope has been important tool to remove ventricular catheters, when you could see the adhesions.(9) The use the endoscope could be particularly important to open loculations and cysts avoiding ventricular entrapment. Patients with ventricular cysts could need more than one catheter. The use of endoscopy to fenestrate the cyst could keep the patient with one catheter or without any shunt system.(10, 11) Conclusion: Shunt malfunction has a lot of possible causes, but a probably ventricular catheter problem is the most common situation. Choose appropriate endoscope rigid or flexible for each case could help to treat and avoid some of ventricular. Endoscopy could be one important tool to help the surgeon to understand and solve this dangerous situation to the patient. Ventricular wall protrusions are a significant cause of proximal shunt obstruction, and they appear to be caused by siphoning of surrounding tissue into the ventricular catheter orifices.

Endoscopic third ventriculostomy for VP shunt malfunction during the third trimester of pregnancy: illustrative case

BACKGROUNDEndoscopic third ventriculostomy (ETV) is a successful procedure for treating noncommunicating hydrocephalus as an alternative to initial ventriculoperitoneal (VP) shunt placement and as a salvage procedure when a VP shunt fails. Physiological changes of pregnancy can lead to VP shunt failure and complicate the management of shunt malfunction, particularly in the third trimester.OBSERVATIONSThe authors present a case in which an ETV was successfully used in the third trimester (31 weeks of gestation) of pregnancy for acute hydrocephalus due to VP shunt malfunction, and the patient went on to deliver a healthy baby at term; the patient remained well in the long-term follow-up. An English-language PubMed literature review revealed four cases of VP shunt failure successfully treated with an ETV in the first or second trimester but no such reports in the third trimester of pregnancy.LESSONSETV appears to be a safe and effective alternative to VP shunt replacement in the late prenatal period of pregnancy.

The Role of 3D Reconstruction of the Skull in Patients with Suspected Shunt Malfunction

Background: Mechanical shunt malfunction may lead to significant morbidity and mortality. Shunt series assessments help evaluate shunt integrity; however, they are of limited value in the area of the skull due to skull curvature, thickness, and air sinuses. We describe the role of 3D bone reconstruction CT (3DCT) in demonstrating the shunt integrity over the skull, comparing this technique to skull X-rays (SXR). Methods: Data were collected retrospectively for shunted patients with concurrent SXR and 3DCT and for patients presenting with shunt failures at the region of the skull, including clinical course and radiological findings. We compared the SXR and 3DCT findings. The 3DCT was reconstructed from standard diagnostic CT protocols performed during evaluation of suspected shunt malfunction and not thin-slice CT protocols. Results: Forty-eight patients with 57 shunts underwent SXR and 3DCT. Interobserver agreement was high for most variables. Both SXR and 3DCT had a high sensitivity, specificity, and accuracy identifying tubing disconnections (between 0.83 and 1). Full valve type and setting were significantly more accurate based on SXR versus 3DCT (>90 vs. <20%), and valve integrity was significantly more readily verified on 3DCT versus SXR (100 vs. 52%). Conclusions: 3DCT and SXR complement each other in diagnosing mechanical shunt malfunctions over the skull. The main limitation of 3DCT is identification of valve type and settings, which are clearer on SXR, while the main limitation of SXR is a less ability to evaluate valve integrity. 3DCT also enables an intuitive 3D understanding of the shunt tubing over the skull.