Perioperative cerebrospinal fluid drainage for the prevention of spinal ischemia after endovascular aortic repair

Postoperative Spinal Cord Ischemia Monitoring: A Review of Techniques Available After Endovascular Aortic Repair

BACKGROUND

Spinal cord ischemia is one of the complications that can occur after open and endovascular thoracoabdominal aortic repair. This occurs despite various perioperative approaches, including distal aortic perfusion, hybrid procedures with extra anatomical bypasses, motor-evoked potential, and cerebrospinal fluid drainage. The inability to recognize spinal ischemia in a timely manner remains a devastating complication after thoracoabdominal aortic repair.

OBJECTIVES

This review aims to look at novel technologies that are designed for continuous monitoring to detect early changes that signal the development of spinal cord ischemia and to discuss their benefits and limitations.

METHODS

We conducted a systematic review of the technologies available for continuous monitoring in the intensive care unit (ICU) for early detection of spinal cord ischemia. Studies were eligible for inclusion if they used different technologies for monitoring spinal ischemia during the postoperative period. All articles that were not available in English were excluded. To ensure that all relevant articles were included, no other significant restrictions were imposed.

RESULTS

We identified 59 studies from outset to December 2022 to be included in our study. New techniques have been studied as potentially useful monitoring tools that could provide simple and effective monitoring of the spinal cord. These include Near-infrared spectroscopy, Contrast-enhanced ultrasound, Magnetic Resonance Imaging, fiber optic monitoring of the spinal cord, and CSF biomarkers.

CONCLUSION

Despite the development of new techniques to monitor for postoperative spinal cord ischemia, their use remains limited. We recommend more future research to ensure rapid intervention for our patients.

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.

Single-Site Review of Spinal Cord Protection Protocols Including the Utilization of Spinal Drains versus Medical Management with Branched Endovascular Aortic Repair

BACKGROUND

Spinal cord ischemia (SCI) continues to be a devastating complication after repair of thoracoabdominal aortic aneurysms. The objective of this review is to present our single-center outcomes after the implementation of a standardized neuroprotective protocol following branched endovascular aortic repair.

METHODS

A standardized neuroprotective protocol including preoperative steroids, acetazolamide, intraoperative hemodynamic parameters, and postoperative treatment goals was initiated in November 2019. Physician-modified branched endovascular repairs were completed at a single center from 2012 to 2021 with outcomes reviewed both before (n = 107) and after (n = 67) the implementation of the neuroprotective protocol. The primary end point was the incidence of any SCI event at 30 days. Secondary end points included all-cause mortality, stroke, myocardial infarction, and renal failure at 30 days. Patients with Crawford extents I-III, renal failure, or necessitating emergent repair were deemed high risk for SCI events and underwent a subset analysis. Survivability after SCI was estimated using Kaplan-Meier tables.

RESULTS

Of the 174 consecutive patients treated, the 67 patients treated following implementation of the neuroprotective protocol were more likely to have experienced a prior myocardial infarction (26.9% vs. 14%; P = 0.0466) and have a history of chronic obstructive pulmonary disease (64.3% vs. 45.8%; P = 0.02). This group was more likely to be treated for paravisceral aneurysms (53.7% vs. 24.3%; P = 0.0002). Postprotocol implementation, spinal drain use was lower (6% vs. 38.3%; P = <0.0001) with 100% of these drains placed in urgent or unstaged thoracoabdominal aortic aneurysm repairs as a part of the protocol. Rates of any SCI event among all patients before and after implementation of the protocol were 9.3% (n = 10 of 107) and 6% (n = 4 of 67; P = 0.57), respectively. In comparison, the protocol significantly reduced SCI rates to 0 (0% vs. 17.1%; P = 0.0407) in high-risk patients. Frequency of renal failure was reduced (3% vs. 14%; P = 0.018) after initiation of the protocol. Patients in the postprotocol group had significantly improved 1-year mortality rate (9% vs. 27.1%; P = 0.0035) and renal failure rates (2% vs. 15%; P = 0.018). Regression models indicated that patients in the postprotocol group had lower likelihood of mortality and renal failure than patients in preprotocol group (P < 0.05) and that spinal drain reduced mortality (P < 0.1).

CONCLUSIONS

Implementation of a standardized neuroprotective protocol that focuses on medical management and fluid dynamics may significantly reduce risk of SCI after branched endovascular repairs, with the most significant improvement of SCI outcomes involving those at greatest risk for developing SCI. Also noteworthy, there was significant improvement to 1-year survivability after the implementation of this neuroprotective protocol.

Cerebrospinal fluid production rate in various pathological conditions: a preliminary study

INTRODUCTION

The cerebrospinal fluid (CSF) production rate in humans is not clearly defined but is estimated to be 18-24 ml/h (Trevisi et al Croat Med J 55(4):377-387 (24); Casey and Vries Childs Nerv Syst 5(5):332-334 (8)). A frequent clinical observation is that patients often drain higher volumes of CSF than can be explained by the assumed 'normal' CSF production rate (PRcsf). In the National Hospital for Neurology and Neurosurgery PRcsf was recorded in a variety of common neurosurgical pathologies using LiquoGuard7, an automated peristaltic pump that accurately controls CSF drainage and maintains a pre-set CSF pressure.

METHODS

A prospective observational study was performed from September 2021 onwards, on all patients in the National Hospital for Neurology and Neurosurgery who required CSF drainage as part of their ongoing treatment. The external drain was connected to a LiquoGuard7 pump (Möller Medical GmbH, Fulda, Germany), and the internal software of LiquoGuard7 was used to measure PRcsf. Statistical analysis used SPSS (version 25.0, IBM) by paired t test, comparing measured rates to hypothetical 'normal' CSF production rates calculated and published by Ekstedt (16-34ml/h) (Ekstedt J Neurol Neurosurg Psychiatry 41(4):345-353 (14)), assuming a similar distribution.

RESULTS

PRcsf was calculated in 164 patients. Suspected normal pressure hydrocephalus (n=41): PRcsf of 79ml/h±20SD (p<0.0001). Post-surgical CSF leak (n=26): PRcsf of 90ml/h±20SD (p<0.0001). Subarachnoid haemorrhage (n=34): PRcsf of 143ml/h±9SD (p<0.0001). Intracerebral haemorrhage (n=22): PRcsf of 137ml/h±20SD (p<0.0001). Spinal lesions (n=7): PRcsf of 130ml/h±20SD (p<0.0032). Pituitary adenomas (n=10): PRcsf of 29 ml/h±9SD (p<0.049). Idiopathic intracranial hypertension (n=15): PRcsf of 86ml/h±10SD (p<0.0001). Decompensated long-standing overt ventriculomegaly (n=4): PRcsf of 65ml/h±10SD (p<0.0001). Cerebral infection (n=5): PRcsf of 90ml/h±20SD (p<0.0001).

CONCLUSION

Net CSF production rate may be higher than expected in many conditions, as measured with new device LiquoGuard7 through the study of net flow rate, which may have implications for clinical decisions on CSF diversion. The conventional understanding of CSF production and circulation does not explain the findings of this study. More extensive studies are needed to validate this technique.

Anaesthesia for vascular emergencies - a state of the art review

In this state-of-the-art review, we discuss the presenting symptoms and management strategies for vascular emergencies. Although vascular emergencies are best treated at a vascular surgical centre, patients may present to any emergency department and may require both immediate management and safe transport to a vascular centre. We describe the surgical and anaesthetic considerations for management of aortic dissection, aortic rupture, carotid endarterectomy, acute limb ischaemia and mesenteric ischaemia. Important issues to consider in aortic dissection are extent of the dissection and surgical need for bypasses in addition to endovascular repair. From an anaesthetist's perspective, aortic dissection requires infrastructure for massive transfusion, smooth management should an endovascular procedure require conversion to an open procedure, haemodynamic manipulation during stent deployment and prevention of spinal cord ischaemia. Principles in management of aortic rupture, whether open or endovascular treatment is chosen, include immediate transfer to a vascular care centre; minimising haemodynamic changes to reduce aortic shear stress; permissive hypotension in the pre-operative period; and initiation of massive transfusion protocol. Carotid endarterectomy for carotid stenosis is managed with general or regional techniques, and anaesthetists must be prepared to manage haemodynamic, neurological and airway issues peri-operatively. Acute limb ischaemia is a result of embolism, thrombosis, dissection or trauma, and may be treated with open repair or embolectomy, under either general or local anaesthesia. Due to hypercoagulability, there may be higher numbers of acutely ischaemic limbs among patients with COVID-19, which is important to consider in the current pandemic. Mesenteric ischaemia is a rare vascular emergency, but it is challenging to diagnose and associated with high morbidity and mortality. Several peri-operative issues are common to all vascular emergencies: acute renal injury; management of transfusion; need for heparinisation and reversal; and challenging postoperative care. Finally, the important development of endovascular techniques for repair in many vascular emergencies has improved care, and the availability of transoesophageal echocardiography has improved monitoring as well as aids in surgical placement of endovascular grafts and for post-procedural evaluation.

Minimally Invasive Segmental Artery Coil Embolization (MISACE) Prior to Endovascular Thoracoabdominal Aortic Aneurysm Repair

PURPOSE

Minimally Invasive Segmental Artery Coil Embolization (MISACE) is a novel approach to reduce paraplegia risk in Thoracoabdominal aortic aneurysm (TAAA) repair with limited data. We report our experience with MISACE as a method of spinal cord pre-conditioning to prevent spinal cord ischemia following endovascular repair of TAAA.

MATERIAL AND METHODS

A retrospective analysis of 17 patients who had an attempted MISACE prior to endovascular TAAA repair with mean follow-up of 350 days (2017-2020). Baseline patient and aneurysm characteristics along with procedural technique and outcomes were analyzed.

RESULTS

Mean age of 69 years and 76.5% were males. TAAA Crawford classification were II, n = 6 (35.3%), III, n = 4 (23.5%) and IV, n = 5 (29.4%). The mean aortic diameter was 70.6 ± 10.9 mm. Staged repair was performed on 9 patients. Technically successful embolization occurred in 14 patients (82.4%) and was unsuccessful in 3 patients. The median number of embolized arteries was 3 and 71% of the target arteries were between T9 and T12. Mean fluoroscopy time was 51.5 ± 22.5 min and mean contrast volume used was 132.8 ± 56.1 mL. Average number of catheters used was 4.6 and 3.5 wires. No complications related to the procedure. Mean interval between embolization to endovascular TAAA repair was 51.2 days (5-110 days). All patients received spinal drainage at the time of repair. Postoperatively, 2/14 of patients developed paraparesis in the MISACE successful group and 1/3 patients developed paraplegia in the unsuccessful group.

CONCLUSIONS

MISACE is a promising strategy to prevent SCI. This data demonstrates the technique is feasible and safe but anatomic challenges remain.

Update Aortenerkrankungen

Die vorliegende Arbeit berichtet über die neuesten wissenschaftlichen Erkenntnisse im Zusammenhang mit Aortenaneurysmen und -dissektionen. Schwerpunkt hierbei sind die Pathophysiologie und Genetik, der Einfluss von Fluorochinolonen auf Aortenaneurysmen und -dissektionen sowie Marker der Aortitis. Ferner werden die wichtigsten aktuellen Leitlinienempfehlungen aus den Jahren 2017 bis 2020 zusammengefasst – der Fokus liegt hierbei auf dem Screening, der Diagnostik, den Grenzwerten für die Therapieindikationen, der Art und den technischen Details der Behandlung sowie Nachsorge von Aneurysmen der Aorta ascendens, des Aortenbogens, der Aorta descendens und abdominalis, Penetrating aortic Ulcers, bei genetisch bedingten Bindegewebserkrankungen mit Aortenbeteiligungen, Aortitis und mykotischen Aneurysmen.

Stroke, spinal cord ischemia and upper limb ischemia in patients undergoing TEVAR with coverage of the left subclavian artery: a case series study

Background

We performed routine spinal fluid drainage for patients who underwent TEVAR for thoracic aortic pathology together with left subclavian artery coverage, which was needed for achievement of a safe proximal sealing zone. We assessed the occurrence of spinal cord ischemia as well the rate of occurrence of other complications such as stroke, and upper limb ischemia.

Results

This was a case series study done between July 2014 and April 2020, in them all the left subclavian artery was covered to ensure a proximal safe seal zone. Routine spinal fluid drainage was done, keeping the spinal fluid pressure < 10–15 mmHg with catheter in place for 48 h. Data was obtained from twenty-three patients who underwent TEVAR for thoracic aortic dissection (73.91%), thoracic aortic aneurysm (21.74%), or ulcer (4.35%). Planning was based upon multi-slice computed tomographic angiography and covering the left subclavian was mandatory to achieve a proximal sealing zone. Technical success was achieved in 100% of cases. 4.35% of patients had three endograft, 56.52% had two endografts, 39.13% had one endograft. All patients lost their radial pulsations immediately after implantation, 8.70% developed post implantation syndrome(fever) that was managed conservatively, 4.35% developed stroke related to the anterior circulation, 4.35% developed signs of spinal cord ischemia. During the follow up, one patient died within 6 h after the procedure due to extensive myocardial infarction (patient was scheduled for CABG after our procedure). 17.40% developed upper limb symptoms that were tolerable and were managed conservatively.

Conclusion

By adopting routine spinal cord drainage and pressure monitoring, we can consider not to revascularize the left subclavian artery prior to TEVAR if it will be covered.

Open aortic arch surgery: 10 years' single-center experience

Introduction

Open aortic arch surgery is a complex cardiac surgical procedure.

Aim

We reviewed the 10-year outcomes of elective aortic arch aneurysm surgery in a single cardiac surgical center.

Material and methods

The analysis includes all patients who underwent elective aortic arch surgery at our institution between January 2010 and December 2020. The study population was divided into group A consisting of patients operated on during the first 5 years, and group B, including patients operated on during the subsequent 5 years. The groups were compared with regard to baseline characteristics, scope of the surgery, operative and postoperative data as well as morbidity and mortality.

Results

Eighty-six elective aortic arch procedures were performed during the analyzed period, including 25 (29%) patients in group A and 61 (71%) patients in group B. The hemiarch procedure was more frequently performed in group A (17 patients, 68%) in comparison to group B (21 patients, 34%) (p = 0.008). Stroke was recorded in 6 (20%) patients from group A and 5 (8.2%) patients from group B (p = 0.002). Five-year survival was 60 ±9.8% for group A, and 81 ±6.2% for group B (log-rank test, p = 0.003).

Conclusions

After completion of the learning curve, open aortic arch surgery is associated with acceptable early mortality, low incidence of stroke, and a high 5-year survival rate.

The Role of Deep Hypothermia in Cardiac Surgery

Hypothermia is defined as a decrease in body core temperature to below 35 °C. In cardiac surgery, four stages of hypothermia are distinguished: mild, moderate, deep, and profound. The organ protection offered by deep hypothermia (DH) enables safe circulatory arrest as a prerequisite to carrying out cardiac surgical intervention. In adult cardiac surgery, DH is mainly used in aortic arch surgery, surgical treatment of pulmonary embolism, and acute type-A aortic dissection interventions. In surgery treating congenital defects, DH is used to assist aortic arch reconstructions, hypoplastic left heart syndrome interventions, and for multi-stage treatment of infants with a single heart ventricle during the neonatal period. However, it should be noted that a safe duration of circulatory arrest in DH for the central nervous system is 30 to 40 min at most and should not be exceeded to prevent severe neurological adverse events. Personalized therapy for the patient and adequate blood temperature monitoring, glycemia, hematocrit, pH, and cerebral oxygenation is a prerequisite and indispensable part of DH.

[The spinal catheter in aortic surgery : Implications for anesthesia]

During surgical repair of aortic pathologies (e.g. dissection, aneurysms), cross-clamping of the aorta or overstenting of critical segmental arteries can lead to ischemia- and edema-related spinal cord damage with subsequent paraplegia. By regulating cerebrospinal fluid pressure, the spinal catheter is an effective method for prophylaxis and treatment of spinal cord ischemia. Due to the high complication rate of the spinal catheter a detailed risk-benefit assessment is obligatory: besides cerebrospinal fluid leakage, postpuncture headaches and local infections, feared complications, such as intracranial bleeding, meningitis and neuraxial hematomas can also occur, sometimes with a significant latent period after termination of the procedure. Adequate training of personnel in the perioperative handling of spinal catheters and meticulous adherence to drainage parameters are important components for increasing procedural safety. This is particularly true since the clinical aspects of catheter-associated complications only slightly differ from that of ischemic spinal cord injury.

Spinal Subdural Hematoma owing to the Removal of Cerebrospinal Fluid Drainage Tube During Thoracic Endovascular Aortic Repair

BACKGROUND

Cerebrospinal fluid (CSF) drainage during the treatment of aortic disease is commonly performed to prevent spinal cord ischemia. Spinal subdural hematoma (SDH) has never been reported after CSF drainage during thoracic endovascular aortic repair (TEVAR). We present a case of concurrent intracranial subarachnoid hemorrhage (SAH) and spinal SDH after CSF drainage tube removal in a patient with TEVAR.

CASE DESCRIPTION

A 73-year-old man was hospitalized to undergo TEVAR. The day before the procedure, a lumbar CSF drainage tube was inserted. Continuous CSF drainage was performed only during the procedure, and the tube was removed the following day. The patient complained of mild back pain on postoperative day 2; headache, bilateral lower limb paresis, and bladder and rectal disturbances developed on postoperative day 5. Brain and spinal magnetic resonance imaging revealed spinal subdural or subarachnoid hematoma and intracranial SAH. Lumbar laminectomies for spinal SDH removal were performed; lower limb strength improved immediately after surgery. At postoperative 2 years, the patient returned to his preoperative activity level; only mild right lower limb numbness persisted.

CONCLUSIONS

We present a rare case of intracranial SAH and spinal SDH that developed after CSF drainage tube removal in a patient with TEVAR. CSF drainage should be carefully considered in patients undergoing aortic procedures, as SAH and spinal SDH may occur in addition to spinal cord ischemia.

Arteriogenesis of the Spinal Cord-The Network Challenge

Spinal cord ischemia (SCI) is a clinical complication following aortic repair that significantly impairs the quality and expectancy of life. Despite some strategies, like cerebrospinal fluid drainage, the occurrence of neurological symptoms, such as paraplegia and paraparesis, remains unpredictable. Beside the major blood supply through conduit arteries, a huge collateral network protects the central nervous system from ischemia—the paraspinous and the intraspinal compartment. The intraspinal arcades maintain perfusion pressure following a sudden inflow interruption, whereas the paraspinal system first needs to undergo arteriogenesis to ensure sufficient blood supply after an acute ischemic insult. The so-called steal phenomenon can even worsen the postoperative situation by causing the hypoperfusion of the spine when, shortly after thoracoabdominal aortic aneurysm (TAAA) surgery, muscles connected with the network divert blood and cause additional stress. Vessels are a conglomeration of different cell types involved in adapting to stress, like endothelial cells, smooth muscle cells, and pericytes. This adaption to stress is subdivided in three phases—initiation, growth, and the maturation phase. In fields of endovascular aortic aneurysm repair, pre-operative selective segmental artery occlusion may enable the development of a sufficient collateral network by stimulating collateral vessel growth, which, again, may prevent spinal cord ischemia. Among others, the major signaling pathways include the phosphoinositide 3 kinase (PI3K) pathway/the antiapoptotic kinase (AKT) pathway/the endothelial nitric oxide synthase (eNOS) pathway, the Erk1, the delta-like ligand (DII), the jagged (Jag)/NOTCH pathway, and the midkine regulatory cytokine signaling pathways.

Spinal Subarachnoid Hematoma After Cerebrospinal Fluid Drainage in Thoracoabdominal Aortic Aneurysm Repair: Case Report and Literature Review

BACKGROUND

Cerebrospinal fluid (CSF) drainage reduces the risk of paraplegia in thoracoabdominal aortic aneurysm (TAAA) repair. Intracranial hemorrhage after TAAA repair has been reported as a rare complication of CSF drainage; however, spinal subarachnoid hematoma has never been reported. Here, we present a case of lumbosacral subarachnoid hematoma after CSF drainage in TAAA repair.

CASE DESCRIPTION

The patient was a 76-year-old man who was hospitalized for TAAA repair. Just before the operation, a CSF drainage catheter was inserted into the L4/5 vertebral interspace. Continuous CSF drainage was performed during the operation. The CSF drain was clamped just after the operation, and the drainage catheters were removed at 24 hours after the operation. On postoperative day 1, the patient experienced pain and paralysis in both lower limbs that worsened over time. Magnetic resonance imaging of the brain and spinal cord was indicative of a spinal subarachnoid hematoma. Removal of hematoma with thoracolumbar and lumbosacral laminectomy was performed, and immediately after the surgery, the pain and paralysis in both lower limbs improved. Six months after the removal of the hematoma, the paralysis in both lower limbs completely resolved and the patient achieved the preinjury activity level.

CONCLUSIONS

We present a rare case of lumbosacral subarachnoid hematoma after CSF drainage in TAAA repair. We should consider spinal subarachnoid hematoma when paralysis in the lower limbs occurs after CSF drainage.