Thrombosis associated with ventriculoatrial shunts

Ventriculoperitoneal shunt migration into the pulmonary artery: Case report and literature review

Cerebrospinal fluid (CSF) shunt placement is a commonly performed procedure for patients with hydrocephalus of various etiologies. We present the case of a 68-year-old male patient treated with a ventriculoperitoneal shunt for obstructive hydrocephalus management. Eight years later, a computed tomography (CT) scan detected migration of distal catheter into the pulmonary artery. We conducted a systematic review in Medline database using PubMed search engine to identify previous cases and their management. Our literature review identified eighteen single case reports describing this complication and different strategies to attempt catheter retrieval. To the best authors' knowledge, this is the first case where conservative management was chosen.

Ventriculoatrial Shunts: Review of Technical Aspects and Complications

Diversion of cerebrospinal fluid is required in many neurosurgical conditions. When a standard ventriculoperitoneal shunt and endoscopic third ventriculostomy are not appropriate options, placement of a ventriculoatrial shunt is a safe, relatively familiar second-line shunting procedure. Herein we reviewed the technical aspects of ventriculoatrial shunt placement using an illustrative case. We focused on the different modalities for inserting and confirming the location of the distal catheter tip. We discussed how to overcome typical difficulties and significant concerns, such as cardiac arrhythmias and venous thrombosis. In addition, we reviewed the current literature for the different complications associated with ventriculoatrial shunt placement.

Indian Society of Pediatric Neurosurgery Consensus Guidelines on Preventing and Managing Shunt Infection: Version 2020-21

Background

Shunt infection is the most significant morbidity associated with shunt surgery. Based on the existing literature for the prevention and management of shunt infection, region and resource-specific recommendations are needed.

Methods

In February 2020, a Guidelines Development Group (GDG) was created by the Indian Society of Paediatric Neurosurgery (IndSPN) to formulate guidelines on shunt infections, which would be relevant to our country and LMIC in general. An initial email survey identified existing practices among the membership of the IndSPN, and eight broad issues pertaining to shunt infection were identified. Next, members of the GDG performed a systematic review of the literature on the prevention and management of shunt infection. Then, through a series of virtual meetings of the GDG over 1 year, evidence from the literature was presented to all the members and consensus was built on different aspects of shunt infection. Finally, the guidelines document was drafted and circulated among the GDG for final approval. Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to grade the evidence and strength of recommendation.

Results

The guidelines are divided into eight sections. Level I and Level II evidence was available for only five recommendations and led to a moderate level of recommendations. Most of the available evidence was at Level III and below, and hence the level of recommendation was low or very low. A consensus method was used to provide recommendations for several issues.

Conclusions

Although most of the recommendations for the prevention and management of shunt infections are based on a low level of evidence, we believe that this document will provide a useful reference to neurosurgeons not only in India but also in other low and middle income countries. These guidelines need to be updated as and when new evidence emerges.

Thrombosis associated with ventriculoatrial shunts

Ventriculoatrial shunts are the most common second-line procedure for cases in which ventriculoperitoneal shunts are unsuitable. Shunting-associated thrombosis is a potentially life-threatening complication after ventriculoatrial shunt insertion. The overall prevalence of this complication is still controversial because of substantial differences in the numbers found in studies using clinical data and in those analyzing postmortem findings. The etiology of thrombosis may be multifactorial, including shunt catheter itself, contents of cerebrospinal fluid, shunt infection, and genetic disorder. The clinical presentation can vary widely, ranging from asymptomatic to a life-threatening condition. Timely recognition of thromboembolic lesions is critical for treatment. However, early diagnosis and management is still challenging because of a relatively long asymptomatic latency and lack of clear guideline recommendations. The purpose of this review is to provide an overview of ventriculoatrial shunt thrombosis, especially to focus on its etiopathogenesis, diagnosis, treatment, and prevention.

Chronic Thromboembolic Pulmonary Hypertension Mimicking Acute Pulmonary Embolism: A Case Report

Patient: Female, 68-year-old

Final Diagnosis: Chronic thromboembolic pulmonary hypertension (CTEPH)

Symptoms: Dsypnea

Medication:—

Clinical Procedure: —

Specialty: Cardiology

Should not we be using aspirin in patients with a ventriculoatrial shunt? Borrowing a leaf from other specialities: a case for surrogate evidence

INTRODUCTION

Ventriculoatrial (VA) shunts are life-saving in circumstances where ventriculoperitoneal shunts (VP) have failed. They are at risk for different complications, and more specific of them are cardiopulmonary complications. Currently, there are no standard recommendations concerning screening for risk factors, prophylaxis, or anticoagulation treatment in patients after VA shunt placement. Our study aims to prospectively study the possible role and efficacy of the use of aspirin to increase the survival of shunts in children with VA shunt and avoid secondary morbidity. In this article, the authors describe the interim results of an ongoing prospective study which supports the use of aspirin for VA shunt.

MATERIALS AND METHODS

The study design is prospective. The duration of the study is 2011 onwards and is ongoing. Hospital ethics board clearance and consent from the family were taken before inclusion in the study. All patients who had VA shunt were given a once-a-day low-antiplatelet dose of aspirin 5 mg/kg, from the first postoperative day onwards. Primary endpoints of the study are as follows: (1) major distal end malfunction documented on echocardiography or (2) any cardiac complications associated with the VA shunt catheter.

RESULTS

We have 6 patient since march 2011, who are being followed up. None of the shunts had malfunctioned until the reporting. None of the patients had any cardiac issues reported. The patients are to be followed continually. The present follow-up ranges from 2.5 to 10 years. The patient follow-up is being continued.

CONCLUSIONS

Aspirin is a drug with well-accepted safety profile, and its use and our preliminary observation and outcome of the use of aspirin in VA shunt are promising.

Ultrasound-guided percutaneous brachiocephalic vein cannulation for ventriculoatrial shunt placement in a child

OBJECTIVE

As far as the ventriculoatrial shunt placement in children is concerned, the percutaneous approach to the internal jugular vein under ultrasonographic control has been hitherto strongly recommended. Unfortunately, children still represent a challenge, having them peculiar characteristics for which the internal jugular vein cannulation shows some disadvantages.

METHODS

In this manuscript, we describe a percutaneous placement of ventriculoatrial shunt via right brachiocephalic vein under intraoperative ultrasonographic control.

CONCLUSIONS

Brachiocephalic vein cannulation in surgery provides notable advantages in paediatric population and it may be considered as the first choice in younger children.

Vegetation of Ventriculoatrial Shunt Managed via Multidisciplinary Surgical Approach

INTRODUCTION

The popularity of the ventriculoatrial shunt as a means for cerebrospinal fluid diversion was temporally limited, overcome by the success of the peritoneum as a site for distal drainage. Nevertheless, it remains an important tool for patients for whom ventriculoperitoneal shunting is not an option.

CLINICAL PRESENTATION

We present the case of a 9-year-old girl with a ventriculoatrial shunt, who had undergone multiple revisions. Ultimately, she suffered a wound dehiscence, resulting in infectious seeding of the bloodstream and formation of a thrombus, presumed granuloma, at the tip of the distal catheter in the right atrium. She underwent successful removal of the lesion via an open approach by our cardiothoracic colleagues.

DISCUSSION

Previous authors have noted a high number of mortalities as a result of these lesions. A collaborative approach resulted in a successful outcome for our patient. Although limited in utility today, the ventriculoatrial shunt remains a common procedure for neurosurgeons today.

CONCLUSION

Recognizing the potential for atrial thrombus formation and using a team approach can help avoid a poor outcome.

Long-Term Outcomes in Ventriculoatrial Shunt Surgery in Patients with Pediatric Hydrocephalus: Retrospective Single-Center Study

OBJECTIVE

Long-term outcomes are rarely reported for patients with pediatric hydrocephalus. Ventriculoperitoneal shunting is the surgical standard; nevertheless, in selected patients, a ventriculoatrial shunt (VAS) remains an important alternative. This study aimed to analyze the causes of VAS revisions and complications.

METHODS

Pediatric patients who underwent their first shunt operation between 1982 and 1992 were included. The timing, cause, and modality of VAS revisions were retrospectively determined.

RESULTS

Overall, 138 patients were treated for hydrocephalus and 61 patients received a VAS during the follow-up period. A primary VAS was the first shunt type in 42 (68.85%) patients. In 19 (31.15%) patients, conversions to second-line VAS were carried out. The rates of VAS revisions performed for dysfunction or elective lengthening of a short atrial catheter were 52.2% and 22.9%, respectively. There was no difference in the number of VAS revisions between patients with primary VASs and second-line VASs. Age at VAS and etiology of hydrocephalus had no effect on the number of revisions. Specific VAS complications were observed in 2 patients. Deep positioning of the distal catheter led to asymptomatic tricuspid regurgitation that was reversible after shortening of the atrial catheter. Another patient presented with shunt nephritis and completely recovered after the atrial catheter was replaced with a peritoneal catheter.

CONCLUSIONS

VAS remains an appropriate second-line alternative in selected patients. Specific VAS complications were rarely observed and completely reversible after treatment. However, regular and specific follow-up examinations are strongly recommended to avoid cardiopulmonary or renal complications.

The influence of cerebrospinal fluid on blood coagulation and the implications for ventriculovenous shunting

OBJECTIVE

The effect of CSF on blood coagulation is not known. Enhanced coagulation by CSF may be an issue in thrombotic complications of ventriculoatrial and ventriculosinus shunts. This study aimed to assess the effect of CSF on coagulation and its potential effect on thrombotic events affecting ventriculovenous shunts.

METHODS

Two complementary experiments were performed. In a static experiment, the effect on coagulation of different CSF mixtures was evaluated using a viscoelastic coagulation monitor. A dynamic experiment confirmed the amount of clot formation on the shunt surface in a roller pump model.

RESULTS

CSF concentrations of 9% and higher significantly decreased the activated clotting time (ACT; 164.9 seconds at 0% CSF, 155.6 seconds at 9% CSF, and 145.1 seconds at 32% CSF). Increased clot rates (CRs) were observed starting at a concentration of 5% (29.3 U/min at 0% CSF, 31.6 U/min at 5% CSF, and 35.3 U/min at 32% CSF). The roller pump model showed a significantly greater percentage of shunt surface covered with deposits when the shunts were infused with CSF rather than Ringer's lactate solution (90% vs 63%). The amount of clot formation at the side facing the blood flow (impact side) tended to be lower than that at the side facing away from the blood flow (wake side; 71% vs 86%).

CONCLUSIONS

Addition of CSF to blood accelerates coagulation. The CSF-blood-foreign material interaction promotes clot formation, which might result in thrombotic shunt complications. Further development of the ventriculovenous shunt technique should focus on preventing CSF-blood-foreign material interaction and stagnation of CSF in wake zones.

A new dynamic model for in vitro evaluation of intravascular devices

INTRODUCTION:

A dynamic model to evaluate thrombus formation on intravascular catheters in vitro is presented. The model enables fluid infusion, variation in the catheter orientation, and variable flow conditions. It was applied on a catheter used to shunt cerebrospinal fluid to a vein, a dural venous sinus, for the treatment of hydrocephalus.

METHODS:

Fresh human blood-filled circuits were circulated in a non-occlusive roller pump. A catheter infused either with cerebrospinal fluid, Ringer's lactate, or no fluid (control) was inserted through each circuit's wall. Sixteen circuits (six cerebrospinal fluid, six Ringer's lactate, four control) ran for 60 min. Qualitative assessment was performed by measuring viscoelastic properties of blood at the start and end of the experiment; quantitative evaluation of clot formation by scanning electron microscope.

RESULTS:

Average blood velocity was 79 mm/s, with a pressure wave between 5 and 15 mm Hg. At the experiment's end, the infused fluid represented 5.88% of the blood/infusion volume in the circuit. The control circuits showed no statistical difference between the start and end for viscoelastic testing, whereas both Ringer's lactate and cerebrospinal fluid enhanced coagulation, most pronounced for the latter. Most thrombus material was observed on catheters in the cerebrospinal fluid group. Clot formation was less pronounced on the surface of the catheter facing the blood flow.

DISCUSSION:

A dynamic model for intravascular catheter testing mimics better clinical conditions when evaluating blood-material interaction. Catheter position, blood flow around the catheter, and infusion fluid all have a potential impact on the hemocompatibility of a given catheter.

Shunt Devices for Neurointensivists: Complications and Management

Cerebrospinal fluid diversion has become the mainstay treatment in hydrocephalus for over 50 years. As the number of patients with ventricular shunt systems increases, neurointensivists are becoming the first-line physicians for many of these patients. When symptoms of a shunt malfunction are suspected and access to a neurosurgeon is limited or delayed, workup and temporizing measures must be initiated. The article highlights the functional nuances, complications, and management of current programmable shunt valves and their MRI sensitivity.

Treating Hydrocephalus with Retrograde Ventriculosinus Shunt: Prospective Clinical Study

BACKGROUND

Since the 1950s, hydrocephalus has been be treated with cerebrospinal fluid (CSF) shunts, usually to the peritoneal cavity or to the right cardiac atrium. However, because of their siphoning effect, these shunts lead to nonphysiologic CSF drainage, with possible comorbidity and high revision rates. More sophisticated shunt valve systems significantly increase costs and technical complexity and remain unsuccessful in a subgroup of patients. In an attempt to obtain physiologic CSF shunting, many neurosurgical pioneers shunted towards the dural sinuses, taking advantage of the physiologic antisiphoning effect of the internal jugular veins. Despite several promising reports, the ventriculosinus shunts have not yet become standard neurosurgical practice.

METHODS

In this single-center prospective clinical study, we implanted the retrograde ventriculosinus shunt, as advocated by El-Shafei, in 10 patients. This article reports on our operation technique and long-term outcome, including 4 patients in whom this shunt was implanted as a rescue operation.

RESULTS

Implantation of a ventriculosinus shunt proved to be feasible, warranting physiologic drainage of CSF. However, in only 3 of 14 patients, functionality of the retrograde ventriculosinus shunt was maintained during more than 6 years of follow-up. In our opinion, these shunts fail because present venous access devices are difficult to implant correctly and become too easily obstructed. After discussion of possible causes of this frequent obstruction, a new dural venous sinus access device is presented.

CONCLUSION

An easy-to-implant and thrombogenic-resistant dural venous sinus access device needs to be developed before ventriculosinus shunting can become general practice.

Multiple Sclerosis - A Vascular Etiology?

From the earliest pathological studies the perivenular localization of the demyelination in multiple sclerosis (MS) has been observed. It has recently been suggested that obstructions to venous flow or inadequate venous valves in the great veins in the neck, thorax and abdomen can cause damaging backflow into the cerebral and spinal cord circulations. Paolo Zamboni and colleagues have demonstrated abnormal venous circulation in some multiple sclerosis patients using non-invasive sonography and invasive venography. Furthermore, they have obtained apparent clinical improvement or stabilization by endovascular ballooning of points of obstruction in the great veins in some, at least temporarily. If non-invasive observations by others validate their initial observations of a significantly increased prevalence of venous obstructions in MS then trials of angioplasty/stenting would be justified in selected cases in view of the biological plausibility of the concept.

Outcomes and Experience with Lumbopleural Shunts in the Management of Idiopathic Intracranial Hypertension

OBJECTIVE

To report five patients who underwent lumbopleural (LPl) shunting for the treatment of idiopathic intracranial hypertension (IIH) and to describe the considerations, complications, and outcomes related to this rarely described procedure.

METHODS

The clinical data of five patients treated with LPl shunting over a 23-year period were retrospectively analyzed. Factors including the age at diagnosis of IIH, age at time of LPl shunting, body mass index (BMI), reason for LPl shunt placement, number of revisions before LPl shunt placement, valve type, time to first revision, presence of overdrainage and its management, complications and their management, survival time of LPl shunt, and clinical course at last follow-up were analyzed.

RESULTS

All patients were morbidly obese females with an average of 4.6 shunt revisions before an LPl shunt. The average overall survival time of the LPl shunt was 48 months. Two patients experienced failure of their LPl shunts with subsequent replacement within the first year. Four patients experienced complications related to shunt overdrainage, requiring placement of an antisiphon device (ASD) or additional valve. One patient developed a symptomatic pleural effusion, and one patient developed a small pneumothorax, which was managed conservatively.

CONCLUSIONS

LPl shunting, though rarely used, is a viable option in the treatment of IIH refractory to standard peritoneal shunting. When pursuing this treatment, a valve and ASD are recommended to mitigate the risks of overdrainage and pleural effusion. Chest imaging should be obtained if the patient becomes symptomatic but can be deferred if the patient remains asymptomatic and is doing well.

Percutaneous removal of right atrial thrombus by suction technique

We present a case of percutaneous removal of a large right atrial thrombus formed after insertion of a ventriculoatrial shunt for hydrocephalus.

Post-thrombotic syndrome in children: a systematic review of frequency of occurrence, validity of outcome measures, and prognostic factors

BACKGROUND

Post-thrombotic syndrome is a manifestation of chronic venous insufficiency following deep venous thrombosis. This systematic review was conducted to critically evaluate pediatric evidence on frequency of occurrence, validity of outcome measures, and prognostic indicators of post-thrombotic syndrome.

DESIGN AND METHODS

A comprehensive literature search of original reports revealed 19 eligible studies, totaling 977 patients with upper/lower extremity deep venous thrombosis. Calculated weighted mean frequency of post-thrombotic syndrome was 26% (95% confidence interval: 23-28%) overall, and differed significantly by prospective/non-prospective analysis and use/non-use of a standardized outcome measure.

RESULTS

Standardized post-thrombotic syndrome outcome measures included an adaptation of the Villalta scale, the Clinical-Etiologic-Anatomic-Pathologic classification, and the Manco-Johnson instrument. Data on validity were reported only for the Manco-Johnson instrument. No publications on post-thrombotic syndrome-related quality of life outcomes were identified. Candidate prognostic factors for post-thrombotic syndrome in prospective studies included use/non-use of thrombolysis and plasma levels of factor VIII activity and D-dimer.

CONCLUSIONS

Given that affected children must endure chronic sequelae for many decades, it is imperative that future collaborative pediatric prospective cohort studies and trials assess as key objectives and outcomes the incidence, severity, prognostic indicators, and health impact of post-thrombotic syndrome, using validated measures.

Remnants of a 35-year-old ventriculo-atrial shunt presenting as orofacial pain

A 36-year-old man presented to his general dental practitioner with pain in the right jaw and neck. This was initially treated as a dento-alveolar abscess. Three days later, he presented to the oral and maxillofacial unit with neck swelling to the right side. An ultrasound confirmed the swelling was due to thrombosis associated with remnants of a ventriculo-atrial (VA) shunt in the right internal jugular vein. This had been placed during the patient's infancy and apparently removed at the age of 8 years. The patient was treated conservatively with warfarin and Coamoxyclav. The patient made a full recovery and was placed on long-term anticoagulant therapy. The introduction of cerebral spinal fluid shunt procedures for the treatment of hydrocephalus has resulted in a reduction in the mortality rate from 80% to 15-20%. Various thrombo-embolic complications have been described with VA shunts. A thorough medical history is absolutely essential in order to identify uncommon causes of common presentations.

Thrombosis in the pediatric population

Whereas thrombotic events in critically ill children do not occur as commonly as in adults, they are being recognized with increasing frequency in the pediatric intensive care unit. The reasons for this are not clear but likely include an increased awareness of the problem and the ability to make a diagnosis using relatively noninvasive tests. In this section, I attempt to define the extent of the problem, summarize and discuss the relevant literature (pointing out where published experience in the pediatric population differs from that in adult patients), and suggest some guidelines regarding thrombophilia treatment and the management of thrombotic events.