Automated intracranial pressure-controlled cerebrospinal fluid external drainage with LiquoGuard

Prospective randomized pilot trial comparing prophylactic and therapeutic cerebrospinal fluid drainage during complex endovascular thoracoabdominal aortic aneurysm repair

BACKGROUND

Endovascular techniques have transformed the management of thoracoabdominal aortic aneurysms (TAAAs). However, spinal cord ischemia (SCI) remains a prevalent and devastating complication. Prophylactic drainage of cerebrospinal fluid (CSF) is among the proposed strategies for prevention of SCI. Although prophylactic CSF drainage is widely used and conceptually attractive, prophylactic CSF drains have not been demonstrated to definitively prevent the occurrence nor mitigate the severity of SCI in endovascular TAAA repair. Whether or not outcomes of prophylactic drains are superior to therapeutic drains remains unknown. This pilot study was performed to determine the feasibility of a randomized clinical trial designed to investigate the role of prophylactic vs therapeutic CSF drains in the prevention of SCI in patients undergoing endovascular TAAA repair using branched and fenestrated endovascular aortic repair (FBEVAR).

METHODS

This was a prospective multicenter randomized pilot clinical trial conducted at The University of Alabama at Birmingham and The University of Massachusetts. Twenty patients were enrolled and randomized to either the prophylactic drainage or therapeutic drainage groups, prior to undergoing FBEVAR for extensive TAAAs and arch aortic aneurysms. This was a pilot feasibility study that was not powered to detect statistical differences in clinical outcomes. The primary outcome was feasibility of randomization and compliance with a shared lumbar drain protocol. Secondary outcomes included rate of drain complications and SCI.

RESULTS

Twenty patients were enrolled and successfully randomized, without any crossovers, to either the control cohort (n = 10), without prophylactic drains, or the experimental cohort (n = 10), with prophylactic drains. There were no differences in age, comorbidities, or history of prior aortic surgery across the cohorts. All patients were treated with FBEVAR. Aneurysm classifications were as follows: Extent I (10%), Extent II (50%), Extent III (35%), and Extent IV (5%). The average length of aortic coverage was 207 ± 21.6 mm. The length of aortic coverage did not vary across cohorts, nor did procedural times or blood loss volume. Compliance with the SCI prevention protocol was 100% across both groups. Within the prophylactic drain cohort, one patient experienced an adverse event related to lumbar drain placement, manifested as an epidural hematoma requiring laminectomy, without neurologic deficit (n = 1/10; 10%). There was one SCI event (n = 1/20; 5%), which occurred in the prophylactic drain cohort on postoperative day 9 following an episode of hypotension related to a gastrointestinal bleed.

CONCLUSIONS

The role of prophylactic CSF drains for the prevention of SCI following endovascular TAAA repair is a topic of ongoing research, with many current practices based on expert opinion and experience, rather than rigorous scientific data. This study demonstrates the feasibility of a multicenter randomized clinical trial to evaluate the role of prophylactic vs therapeutic CSF drains in the prevention of SCI in patients undergoing endovascular TAAA repair.

Patient-specific automated cerebrospinal fluid pressure control to augment spinal wound closure: a case series using the LiquoGuard®

OBJECTIVE

Spinal cerebrospinal fluid (CSF) leaks are common, and their management is heterogeneous. For high-flow leaks, numerous studies advocate for primary dural repair and CSF diversion. The LiquoGuard7® allows automated and precise pressure and volume control, and calculation of patient-specific CSF production rate (prCSF), which is hypothesized to be increased in the context of durotomies and CSF leaks.

METHODS

This single-centre illustrative case series included patients undergoing complex spinal surgery where: 1) a high flow intra-operative and/or post-operative CSF leak was expected and 2) lumbar CSF drainage was performed using a LiquoGuard7®. CSF diversion was tailored to prCSF for each patient, combined with layered spinal wound closure.

RESULTS

Three patients were included, with a variety of pathologies: T7/T8 disc prolapse, T8-T9 meningioma, and T4-T5 metastatic spinal cord compression. The first two patients underwent CSF diversion to prevent post-op CSF leak, whilst the third required this in response to post-op CSF leak. CSF hyperproduction was evident in all cases (mean >/=140ml/hr). With patient-specific CSF diversion regimes, no cases required further intervention for CSF fistulae repair (including for pleural CSF effusion), wound breakdown or infection.

CONCLUSIONS

Patient-specific cerebrospinal fluid drainage may be a useful tool in the management of high-flow intra-operative and post-operative CSF leaks during complex spinal surgery. These systems may reduce post-operative CSF leakage from the wound or into adjacent body cavities. Further larger studies are needed to evaluate the comparative benefits and cost-effectiveness of this approach.

Oxidative Stress and Intracranial Hypertension after Aneurysmal Subarachnoid Hemorrhage

Intracranial hypertension is a common phenomenon in patients with aneurysmal subarachnoid hemorrhage (aSAH). Elevated intracranial pressure (ICP) plays an important role in early brain injuries and is associated with unfavorable outcomes. Despite advances in the management of aSAH, there is no consensus about the mechanisms involved in ICP increases after aSAH. Recently, a growing body of evidence suggests that oxidative stress (OS) may play a crucial role in physio-pathological changes following aSAH, which may also contribute to increased ICP. Herein, we discuss a potential relation between increased ICP and OS, and resultantly propose antioxidant mechanisms as a potential therapeutic strategy for the treatment of ICP elevation following aSAH.

Mechanical Complications of External Ventricular and Lumbar Drains

BACKGROUND

External ventricular drain (EVD) and lumbar drain insertion are 2 of the most commonly performed neurosurgical procedures worldwide for acute hydrocephalus. Mechanical complications, such as obstruction or cerebrospinal fluid (CSF) leakage, are often seen and may contribute toward significant patient morbidity. Different CSF drainage methods are advocated to reduce the incidence of complications, but evidence regarding comparative effectiveness is limited.

METHODS

In this single-center prospective cohort study, the incidence of mechanical complications and associated interventional factors, including choice of drain, collecting system, and location, were studied in patients requiring CSF diversion for acute hydrocephalus. Univariate analyses were performed to explore trends within the data, followed by a repeated-measures mixed-effects regression to determine the independent influence of drain device on mechanical failure.

RESULTS

Sixty-one patients required CSF diversion between January 2020 and March 2021, via 3 different drain types (lumbar drain, tunneled, and bolted EVD) and 2 collection systems (LiquoGuard 7 and AccuDrain), performed in either theater or intensive care. Twenty-one patients (39%) experienced a mechanical complication, with blockage being the most common. Multivariate analyses showed that bolted EVDs (odds ratio, 0.08; confidence interval, 0.01-0.58) and LiquoGuards (OR, 0.23; CI, 0.08-0.69) were significantly associated with fewer mechanical complications compared with tunneled EVDs and gravity-based collection systems, respectively (P ≤ 0.01).

DISCUSSION

Drain device has an influence on the occurrence of EVD-related complications. These preliminary findings suggest that choosing bolted EVDs and motor-assisted drainage can reduce drain-associated mechanical failure. A randomized controlled trial comparing drain devices is required to confirm these findings.

Implementation of an Automated Cerebrospinal Fluid Drainage System for Early Mobilization in Neurosurgical Patients

BACKGROUND

Automated cerebrospinal fluid (CSF) drainage systems allow for the mobilization of patients with an external CSF drain. The aim of this study is to describe the implementation of an automated CSF drainage system in neurosurgical patients with external CSF drains.

METHODS

A feasibility study was performed using an automated CSF drainage system (LiquoGuard^®7, Möller Medical GmbH, Fulda, Germany) in adult neurosurgical patients treated with external lumbar or external ventricular drains between December 2017 and June 2020. Limited mobilization was allowed-patients were allowed to adjust their inclined beds, sit in chairs and walk under the supervision of a nurse or physical therapist. The primary outcome was the number of prematurely terminated drainage sessions.

RESULTS

Twenty-three patients were included. Drainage was terminated prematurely in eight (35%) patients. In three (13%) of these patients, drainage was terminated due to signs of hydrocephalus. Pressure-controlled drainage in patients with external lumbar drains (ELD) showed inaccurate pressure curves, which was solved by using volume-controlled drainage in ELD patients.

CONCLUSION

The implementation of an automated CSF drainage system (LiquoGuard^®7) for CSF drainage allows for early mobilization in a subset of patients with external CSF drains. External lumbar drains require volume-based drainage rather than differential pressure-dependent drainage.

A Method for Monitoring the Working States of Drainage Tubes Based on the Principle of Capacitance Sensing

The real-time monitoring of the working status of drainage tubes is crucial for successful surgical drainage and for informing clinicians of the drainage conditions of patients at different stages, to enable objective diagnosis and treatment. In this study, a method for monitoring the drainage condition of drainage tubes was proposed. The method was based on the principle of capacitance and was developed by analyzing the major states of drainage tubes in the process of drainage. Meanwhile, the principle of interdigital capacitance monitoring drainage was analyzed, and an interdigital capacitance device for the real-time monitoring of the working status of drainage tubes was designed. Ultimately, an experimental system for drainage simulation was established on the basis of the interdigital capacitance device and method for drainage monitoring. Results showed that the interdigital capacitance device for drainage monitoring can identify unobstructed or blocked drainage tubes effectively in real time. The device has a hydrophobic surface, so its electrodes do not undergo electrolysis and pollution due to adhesion. Hence the proposed capacitance-based method for monitoring the working states of drainage tubes has good application prospects in the postoperative drainage of abdominal and thoracic cavities.

The role of ICP monitoring in patients with persistent cerebrospinal fluid leak following spinal surgery: a case series

BACKGROUND

Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively common surgical complication. A disturbance in the underlying CSF dynamics could be the causative factor in a small group of patients with refractory CSF leaks that require multiple surgical repairs and prolonged hospital admission.

METHODS

A retrospective case series of patients with persistent post spinal surgery CSF leak referred to the hydrocephalus service for continuous intracranial pressure (ICP) monitoring. Patients' notes were reviewed for medical history, ICP data, radiological data, and subsequent management and outcome.

RESULTS

Five patients (two males/three females, mean age, 35.4 years) were referred for ICP monitoring over a 12-month period. These patients had prolonged CSF leak despite multiple repair attempts 252 ± 454 days (mean ± SD). On ICP monitoring, all five patients had abnormal results, with the mean ICP 8.95 ± 4.41 mmHg. Four had abnormal pulse amplitudes, mean 6.15 mmHg ± 1.22 mmHg. All five patients underwent an intervention. Three patients underwent insertion of ventriculoperitoneal (VP) shunts. One patient had venous sinus stent insertion and one patient underwent medical management with acetazolamide. All five of the patients' CSF leak resolved post intervention. The mean time to resolution of CSF leak post intervention was 10.8  ± 12.9 days.

CONCLUSIONS

Abnormal cerebrospinal fluid dynamics could be the underlying factor in patients with a persistent and treatment-refractory CSF leak post spinal surgery. Treatments aimed at lowering ICP may be beneficial in this group of patients. Whether abnormal pressure and dynamics represent a pre-existing abnormality or is induced by spinal surgery should be a subject of further study.

Early Experience of Automated Intraventricular Type Intracranial Pressure Monitoring (LiquoGuard®) for Severe Traumatic Brain Injury Patients

Objective

The LiquoGuard® system is a new ventricular-type monitoring device that facilitates intracranial pressure (ICP)-controlled or volume-controlled drainage of cerebrospinal fluid (CSF). The purpose of this study is to report the authors' experience with the LiquoGuard® ICP monitoring system, as well as the clinical safety, usefulness, and limitations of this device in the management of patients with traumatic brain injury (TBI).

Methods

Intraventricular ICP monitoring was performed on 10 patients with TBI using the LiquoGuard® monitoring system. ICP measurements, volume of drained CSF, and clinical outcomes were analyzed and discussed.

Results

ICP monitoring was performed on 10 patients for a mean duration of 6.9 days. With a mean 82,718 records per patient, the mean initial ICP was 16.4 mm Hg and the average ICP across the total duration of monitoring was 15.5 mm Hg. The mean volume of drained CSF was 29.2 cc/day, with no CSF drained in 4 patients. Seven of 10 patients showed 1 or 2 episodes of abnormal ICP measurements. No patient exhibited complications associated with ICP monitoring.

Conclusion

The LiquoGuard® system is a versatile tool in the management of TBI patients. Its use is both reliable and feasible for ICP monitoring and therapeutic drainage of CSF. However, episodes of abnormal ICP measurements were frequently observed in patients with slit ventricles, and further study may be needed to overcome this issue.

Early Experience With Automatic Pressure-Controlled Cerebrospinal Fluid Drainage During Thoracic Endovascular Aortic Repair

Purpose: To report initial experience with automatic pressure-controlled cerebrospinal fluid drainage (CSFD) during thoracic endovascular aortic repair (TEVAR). Methods: A prospective nonrandomized study enrolled 30 consecutive patients (median age 68 years, range 42–89; 18 men) who underwent TEVAR between March 2012 and July 2013 and were considered to be at high risk for postoperative spinal cord ischemia (SCI), fulfilling 2 of the following criteria: stent-graft length >20 cm, left subclavian artery coverage, and previous infrarenal aortic repair. All patients received perioperative CSFD via the LiquoGuard system. The protocol aimed for a CSF pressure of 10 mm Hg and duration of CSFD of 3 or 7 days in asymptomatic or symptomatic patients, respectively. Muscle strength of the lower extremities was assessed with the Oxford muscle strength grading scale. Results: Completion of the CSFD protocol was achieved in 26 (87%) of 30 patients. CSFD was prematurely stopped due to catheter dislocation in 1 patient and bloody spinal fluid in 3 patients. CSFD was performed for a median of 3 days (range 1–7). Median total CSFD volume was 714 mL (range 13–2369), with a median 192 mL drained per 24 hours. The SCI rate was 3% (1/30). CSFD-related complications were observed in 33% of the patients: 1 fatal intracranial hemorrhage, 3 bloody spinal fluid episodes, 3 persistent CSF leaks requiring epidural blood patch, and 3 post lumbar puncture headaches. Mortality during a median follow-up of 16 months (range 10–25) was 3% (1/30). Conclusion: Prophylactic CSFD was associated with a low SCI rate in a high-risk patient collective undergoing TEVAR. Monitoring and drainage by an automatic modus was feasible, reproducible, and reliable but associated with relevant drainage-associated complications.

Microdialysis Monitoring of CSF Parameters in Severe Traumatic Brain Injury Patients: A Novel Approach

Background: Neuro-intensive care following traumatic brain injury (TBI) is focused on preventing secondary insults that may lead to irreversible brain damage. Microdialysis (MD) is used to detect deranged cerebral metabolism. The clinical usefulness of the MD is dependent on the regional localization of the MD catheter. The aim of this study was to analyze a new method of continuous cerebrospinal fluid (CSF) monitoring using the MD technique. The method was validated using conventional laboratory analysis of CSF samples. MD-CSF and regional MD-Brain samples were correlated to patient outcome.

Materials and Methods: A total of 14 patients suffering from severe TBI were analyzed. They were monitored using (1) a MD catheter (CMA64-iView, n = 7448 MD samples) located in a CSF-pump connected to the ventricular drain and (2) an intraparenchymal MD catheter (CMA70, n = 8358 MD samples). CSF-lactate and CSF-glucose levels were monitored and were compared to MD-CSF samples. MD-CSF and MD-Brain parameters were correlated to favorable (Glasgow Outcome Score extended, GOSe 6–8) and unfavorable (GOSe 1–5) outcome.

Results: Levels of glucose and lactate acquired with the CSF-MD technique could be correlated to conventional levels. The median MD recovery using the CMA64 catheter in CSF was 0.98 and 0.97 for glucose and lactate, respectively. Median MD-CSF (CMA 64) lactate (p = 0.0057) and pyruvate (p = 0.0011) levels were significantly lower in the favorable outcome group compared to the unfavorable group. No significant difference in outcome was found using the lactate:pyruvate ratio (LPR), or any of the regional MD-Brain monitoring in our analyzed cohort.

Conclusion: This new technique of global MD-CSF monitoring correlates with conventional CSF levels of glucose and lactate, and the MD recovery is higher than previously described. Increase in lactate and pyruvate, without any effect on the LPR, correlates to unfavorable outcome, perhaps related to the presence of erythrocytes in the CSF.

Management of intracerebral pressure in the neurosciences critical care unit

Management of intracranial pressure in neurocritical care remains a potentially valuable target for improvements in therapy and patient outcomes. Surrogate markers of increased intracranial pressure, invasive monitors, and standard therapy, as well as promising new approaches to improve cerebral compliance are discussed, and a current review of the literature addressing this metric in neuroscience critical care is provided.