Treatment of ruptured intracranial aneurysms by embolization with controlled detachable coils

A narrative review of the screening protocols investigating intracranial aneurysms in polycystic kidney disease

INTRODUCTION

Intracranial aneurysms (IA) are a common complication of autosomal dominant polycystic kidney disease (ADPKD). Screening protocols that exist for IA in ADPKD patients are an important component of disease monitoring to enable appropriate preventative measures and precautions to avoid IA rupture with its associated morbidly and mortality.

AIMS

The aims of this review are to analyse the different types of screening protocols that exist by referencing the lead time between IA diagnosis and rupture in ADPKD patients, the purpose and importance of screening, the types of imaging modalities used, and patient outcomes. We will also consider cost-effectiveness and its relation in establishing a screening protocol as this is an important factor.

METHODOLOGY

A literature search was conducted in April 2022 using PubMed, BMJ electronic databases, Dynamed, NICE guidelines and Cochrane databases for articles published between 1990 and 2022 with special interest in IA, ADPKD and screening protocols. The only exclusion criteria were patients who were diagnosed with ADPKD <30 years of age.

RESULTS

Our findings suggest that if a patient with ADPKD presents with either a positive family history of IA and/or cerebrovascular events and/or is above 40 years of age, then they should have a magnetic resonance angiography (MRA) scan every 5 years to monitor IA formation and growth with annual follow-ups. This may contribute to decreased patient morbidity and mortality in ADPKD-positive patients.

CONCLUSION

While there is some evidence proving that screening protocols decrease the morbidity and mortality of ADPKD patients, none have been recommended. The screening protocol suggested in this review should be used as a guideline for future studies that will try and establish a national or international guidelines that can be used by nephrologists and neurosurgeons worldwide.

The evolution of intracranial aneurysm treatment techniques and future directions

Treatment techniques and management guidelines for intracranial aneurysms (IAs) have been continually developing and this rapid development has altered treatment decision-making for clinicians. IAs are treated in one of two ways: surgical treatments such as microsurgical clipping with or without bypass techniques, and endovascular methods such as coiling, balloon- or stent-assisted coiling, or intravascular flow diversion and intrasaccular flow disruption. In certain cases, a single approach may be inadequate in completely resolving the IA and successful treatment requires a combination of microsurgical and endovascular techniques, such as in complex aneurysms. The treatment option should be considered based on factors such as age; past medical history; comorbidities; patient preference; aneurysm characteristics such as location, morphology, and size; and finally the operator’s experience. The purpose of this review is to provide practicing neurosurgeons with a summary of the techniques available, and to aid decision-making by highlighting ideal or less ideal cases for a given technique. Next, we illustrate the evolution of techniques to overcome the shortfalls of preceding techniques. At the outset, we emphasize that this decision-making process is dynamic and will be directed by current best scientific evidence, and future technological advances.

Update on the management of subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular disease. Outcome after SAH is mainly determined by the initial severity of the hemorrhage. Neuroimaging, in particular computed tomography, and aneurysm repair techniques, such as coiling and clipping, as well as neurocritical care management, have improved during the last few years. The management of a patient with SAH should have an interdisciplinary approach with case discussions between the neurointensivist, interventionalist and the neurosurgeon. The patient should be treated in a specialized neurointensive care unit of a center with sufficient SAH case volume. Poor-grade patients can be observed for complications and delayed cerebral ischemia through continuous monitoring techniques in addition to transcranial Doppler ultrasonography such as continuous electroencephalography, brain tissue oxygenation, cerebral metabolism, cerebral blood flow and serial vascular imaging. Neurocritical care should focus on neuromonitoring for delayed cerebral ischemia, management of hydrocephalus, seizures and intracranial hypertension, as well as of medical complications such as hyperglycemia, fever and anemia.

Coexistence of vasospasm and microembolism detected by transcranial Doppler ultrasonography in a patient with subarachnoid haemorrhage

Delayed cerebral ischaemia as a clinical expression of vasospasm is one of the main complications of subarachnoid haemorrhage. In some cases, ischaemic manifestations can be related to cerebral emboli, but the relationship between vasospasm, damaged endothelial lining, and embolism, remains to be proven. The case is presented of a 56-year-old female patient who, 5 days after the clipping of an aneurysm in the left middle cerebral artery (MCA), suffered transient ischaemic attacks (TIAs) of this arterial territory. Transcranial Doppler ultrasonography showed an increment of the left MCA mean flow velocity, and 12 microembolic signals were detected in 30 mins. The coexistence of microemboli signals with severe vasospasm in the same arterial segment might suggest a causal relationship between cerebral embolism, severity of vasospasm, and TIAs.

Endovascular embolization of intracranial aneurysms

Intracranial aneurysm (ICA) is a common condition but with a high mortality rate when rupture occurs. The treatment of ruptured or unruptured ICA, especially with an endovascular approach, has been evolving rapidly. The current generally accepted opinion suggests that endovascular embolization is an effective technique for preventing the recurrence of aneurysm rupture, but the rebleeding rate after endovascular embolization is found to be higher than that after surgical clipping. In addition, long-term follow-up data are required for the evaluation of the effectiveness of endovascular treatment in unruptured ICA. This review presents the current understanding of ICA, the selection of optimal treatment approaches, and in particular, the advances in endovascular embolization in the treatment of ICA, including embolic materials, therapeutic and assisting techniques, long-term effectiveness, and limitations.

Anaesthesia for endovascular management of cerebral aneurysms

Subarachnoid haemorrhage due to rupture of cerebral aneurysms is a multisystem disease. Treatment of the condition in the past has relied on craniotomy and clipping of the aneurysm to prevent a recurrent haemorrhage. There is now emerging evidence to suggest that endovascular treatment of cerebral aneurysms may reduce the morbidity associated with open surgery. The anaesthetic management of interventional neuroradiology also creates new challenges due to the novel approach to treatment. Anaesthetists need to be familiar with this procedure and the management of potential complications. This review provides an overview such considerations.

Anaesthesia for endovascular treatment of cerebral aneurysms

Endovascular treatment of cerebral aneuryms is now widely used and has important implications for the neuroanaesthetist. Significant issues include the decision to use general anaesthesia, factors associated with anaesthesia in the interventional radiology suite and treatment of complications. As endovascular treatment is now supported by evidence and established in practice, neuroanaesthetists should be involved in planning these procedures from a process, and individual patient, perspective.