Endovascular Surgery of Cerebral Aneurysms

Foreword
Preface
Acknowledgment
Contents
About the Editor
1: Pathophysiology of Cerebral Aneurysms
	1.1	 Introduction
	1.2	 Structure of the Cerebral Arteries
	1.3	 Formation of Intracranial Aneurysms
		1.3.1	 Hemodynamic Factors and Associated Structural Changes
		1.3.2	 Genetic Factors
		1.3.3	 Molecular Changes
		1.3.4	 Hormonal Changes Related to Aneurysm Formation and Rupture
	1.4	 Risk Factors Associated with Formation and Rupture of Cerebral Aneurysms
		1.4.1	 Conventional Risk Factors
		1.4.2	 Innate Risk Factors
		1.4.3	 Acquired Risk Factors
	1.5	 Common Risk Factors for Cerebral Aneurysm Rupture
	References
2: Aneurysmal SAH Induced Vasospasm: Pathogenesis and Management
	2.1	 Introduction
	2.2	 Delayed Cerebral Vasospasm
	2.3	 The Pathophysiological Changes After SAH
		2.3.1	 Understanding Early Brain Injury
	2.4	 What Leads to Vaso Constriction?
		2.4.1	 Endothelin 1 (The Physiological Vasoconstrictor)
		2.4.2	 Nitric Oxide (The Physiological Vasodilator)
		2.4.3	 Inflammatory Changes Leading to Apoptosis
		2.4.4	 The Ischemic Insult
		2.4.5	 Free Oxygen Radicals
		2.4.6	 Is Vasospasm All About Cerebral Vasculature?
	2.5	 Diagnosis of Vasospasm
	2.6	 Management Options for Vasospasm
		2.6.1	 Trials on Targeted Substrates
			2.6.1.1	 Lipid Peroxidation Inhibitors
		2.6.2	 Role of Endothelin-1 Antagonist
		2.6.3	 Is There Any Role of Statins?
		2.6.4	 Augmenting NO Activity
		2.6.5	 Sildenafil Citrate
			2.6.5.1	 Nascent NO Donors
			2.6.5.2	 Magnesium Sulfate
	2.7	 Treatment Regime for SAH/Vasospasm
		2.7.1	 Optimizing Physiological Disruption
			2.7.1.1	 Catecholamine Surge and Increased Sympathetic Activity
			2.7.1.2	 Controlling Body Temperature
			2.7.1.3	 Electrolyte Management
			2.7.1.4	 Maintaining Cerebral Perfusion
			2.7.1.5	 Calcium Channel Antagonists
			2.7.1.6	 Nimodipine
		2.7.2	 Strategies to Reduce Blood Load in Subarachnoid Space
			2.7.2.1	 Lumbar Drain
			2.7.2.2	 Cisternal Lavage and Local Thrombolytics
		2.7.3	 Intrathecal Treatment Options
			2.7.3.1	 Intrathecal Thrombolysis
			2.7.3.2	 Intrathecal Nicardipine
		2.7.4	 Endovascular Intervention for Vasospasm
		2.7.5	 Role of Intra-arterial Pharmacotherapy
			2.7.5.1	 Intra-arterial Nimodipine
			2.7.5.2	 Papaverine
			2.7.5.3	 Milrinone
			2.7.5.4	 Balloon Angioplasty
	2.8	 Conclusion
	References
3: History of Endovascular Surgery of Cerebral Aneurysms
	3.1	 Introduction
	3.2	 Middle Ages
	3.3	 Twentieth Century Era
	References
4: Drugs in Neurovascular Intervention
	4.1	 Introduction
	4.2	 Fibrinolytic Agents
		4.2.1	 Alteplase
		4.2.2	 Tenecteplase
	4.3	 Antiplatelet Agents
		4.3.1	 Aspirin
		4.3.2	 ADP Antagonists/P2Y12 Inhibitors
		4.3.3	 GP IIb/IIIa Inhibitors
		4.3.4	 Phosphodiesterase Inhibitors
	4.4	 Anticoagulating Agents
	4.5	 Treatment of Vasospasm: (Chemical Angioplasty)
	4.6	 Radial Artery Cocktail
	4.7	 Statins (Hypolipidemic Therapy)
	References
5: Current Devices and Uses
	5.1	 Introduction
		5.1.1	 The Guglielmi Detachable Coil System (GDC)
		5.1.2	 Balloon Assisted Coiling (BAC)
		5.1.3	 Stent-Assisted Coiling (SAC)
		5.1.4	 Flow Diverters
		5.1.5	 Flow Disrupters
		5.1.6	 Hybrids and Other Novel Devices
	5.2	 Conclusion
	References
6: Neuroendovascular Management of Wide-Neck Bifurcation Aneurysms
	6.1	 Background
	6.2	 Three Types of Bifurcation Aneurysms
		6.2.1	 Saccular Aneurysms
		6.2.2	 Dissecting Aneurysms
		6.2.3	 Giant Serpentine Aneurysms
	6.3	 Neuroendovascular Strategies for Bifurcation Aneurysms
	6.4	 Coiling
	6.5	 Double Catheter Technique
	6.6	 Balloon-Assisted Coiling
	6.7	 Stent-Assisted Coiling
	6.8	 Y-stenting Technique
	6.9	 Intrasaccular Flow Disruptions
	6.10	 Intralumenal Flow Diversion
	6.11	 The pCONus Bifurcation Aneurysm Implant
	6.12	 Salvation Techniques
	6.13	 Observation for Bifurcation Aneurysms
	6.14	 Conclusion
	References
7: Dual Lumen Balloon-Assisted Coil Embolization
	7.1	 Rationale for the Use of Double-Lumen Balloon
	7.2	 Advantages
		7.2.1	 General Advantages of Balloons
		7.2.2	 Advantages Specific to Double-Lumen Balloons
	7.3	 Potential Complications
	7.4	 Specific Indications
	7.5	 Available Options for Double-Lumen Balloons
	7.6	 Technique for Device Preparation (Manufacturer Recommendations)
		7.6.1	 Ascent Balloon Preparation
		7.6.2	 Scepter Balloon Preparation
	7.7	 Device Uses
	7.8	 Alternative Options
	References
8: Blood Blister-Like Aneurysms: Pathogenesis and Endovascular Treatment
	8.1	 Introduction
		8.1.1	 Pathogenesis of BBA
		8.1.2	 Neuroendovascular Strategies
	8.2	 Conclusions
	References
9: Flow Diverter Stents
	9.1	 Introduction
	9.2	 Study of the FD Characteristics
		9.2.1	 Flow Diverters: Braided and Low Porosity Stents
		9.2.2	 Porosity
		9.2.3	 Pore Density
		9.2.4	 Composition
		9.2.5	 Choice
		9.2.6	 Implantation
		9.2.7	 Surface Treatment
		9.2.8	 Extremities
		9.2.9	 In Vitro Studies
		9.2.10	 Computational Fluid Dynamic Studies
		9.2.11	 Cellular and Tissular Level
		9.2.12	 Factors Related to Aneurysm Characteristics
			9.2.12.1	 The Importance of Aneurysm Size and Volume
			9.2.12.2	 The Importance of a Curve at the FSS or Covered Branch
			9.2.12.3	 Lateral or Bifurcation Aneurysms and Fusiform Aneurysms
			9.2.12.4	 The Covered or “Jailed” Branch
			9.2.12.5	 Factors Related to the Choice of the FD
				Compaction of the Flow Diverter by the Operator
	9.3	 Clinical Studies
		9.3.1	 Efficacy
		9.3.2	 Classifications
			9.3.2.1	 O’Kelly–Marotta (OKM) Classification [103]
			9.3.2.2	 Kamran–Byrne (KB) Classification [104]
			9.3.2.3	 Grunwald Classification (SMART) [105]
	9.4	 Complications
		9.4.1	 Ischemic
		9.4.2	 Hemorrhagic
	9.5	 Antiplatelets Regimen
	References
10: The Off-Label Use of Flow Diverter
	10.1	 Blister-Like Aneurysm
	10.2	 Distal Circulation Aneurysm
	10.3	 Previously Treated Aneurysms
	10.4	 Posterior Circulation Aneurysms
	10.5	 Acute Ruptured Aneurysms
	10.6	 Intracranial Dissecting Aneurysms
	References
11: Complications of Aneurysm Embolization and Their Management: Basic and Practical Considerations
	11.1	 Introduction
	11.2	 Hemorrhagic Complications
		11.2.1	 Incidence, Risk Factors, and Mechanisms of IOB
		11.2.2	 Comparison Between the Outcomes of Coiling and Clipping
		11.2.3	 Results
			11.2.3.1	 Material and Methods
			11.2.3.2	 Results
			11.2.3.3	 Case Presentations
			11.2.3.4	 Discussion
		11.2.4	 Management of Hemorrhagic Complications
	11.3	 Ischemic Complications
		11.3.1	 General Considerations
		11.3.2	 Local Thrombus Formation: Angiographic Classifications of Appearance and Management
			11.3.2.1	 Case Presentation
				Case 5 (Fig. 11.5). Grade 1: Microthrombus Formation
				Case 6 (Fig. 11.6). Grade 3: Thrombus Formation with Significant Decrease in Blood Flow
				Case 7 (Fig. 11.7). Grade 1: Microthrombus Formation
		11.3.3	 Risk Factors and Considerations
	11.4	 Delayed Encephalopathy
		11.4.1	 General Considerations
		11.4.2	 Case Presentation
	11.5	 Conclusion
	References
12: Clipping in Uncoilable Aneurysms
	12.1	 Introduction
	12.2	 Factors for Decision-Making in Coiling or Clipping
	12.3	 What does the Landmark Trials Say?
	12.4	 Group I: Uncoilable Aneurysms
		12.4.1 Tiny Aneurysm Are Difficult to Coil (Fig. 12.1a, b)
		12.4.2 Blood Blister-Like Aneurysm
		12.4.3 Wide-Necked Aneurysm (Fig. 12.3a, b)
		12.4.4 Bad Contour (Fig. 12.4a, b)
		12.4.5 Incorporation of Parent or Branch Arteries (Fig. 12.5a, b)
		12.4.6 Large and Giant Aneurysms (Fig. 12.6a–e)
		12.4.7 Poor Access (Figs. 12.7a–c and 12.8a, b)
		12.4.8 Complex Anatomy (Fig. 12.9 a–d)
		12.4.9 Resistant Vasospasm (Fig. 12.10)
		12.4.10 Pseudoaneurysms (Fig. 12.11)
		12.4.11 Clipping as an Option to Newer Endovascular Techniques When Coiling Is Not Feasible?
		12.4.12 Coiling Risks Which Can Be Handled Well by Clipping
		12.4.13 Why Clipping Is Better in Specific Cases?
	12.5	 Group II: Unclippable Aneurysms
	12.6	 Group III: Both Unclippable and Uncoilable Aneurysms
	12.7	 Cost of Hospitalization
	12.8	 Conclusions
	References
13: Open Treatment of Cerebral Aneurysms in the Endovascular Age
	13.1	 Introduction
	13.2	 General Advantages of Open Surgical Treatment of Aneurysms
	13.3	 Wide-Neck Aneurysms
	13.4	 Giant Aneurysms
	13.5	 Neural Compression
	13.6	 Epilepsy
	13.7	 Small Aneurysms
	13.8	 Blister Aneurysms
	13.9	 Thrombotic Aneurysms
	13.10	 Ruptured Aneurysms Presenting with Intracerebral Hemorrhage
	13.11	 Young Population
	13.12	 Fusiform Aneurysms
	13.13	 Multiple Aneurysms
	13.14	 Middle Cerebral Artery Aneurysms
	13.15	 Anterior Communicating Artery Aneurysms
	13.16	 Elderly Population
	13.17	 Recurrence After Endovascular Treatment
	13.18	 Future of Open Aneurysm Surgery
	13.19	 Conclusion
	References
14: Recent Advances in Cerebral Aneurysms
	14.1	 Introduction
	14.2	 Pathophysiology of Aneurysms-Advanced Concepts
	14.3	 Advances in Imaging
	14.4	 Medical Management of Cerebral Aneurysms
	14.5	 Clipping Versus Coiling
	14.6	 Advances in Microneurosurgery
	14.7	 Advances in Endovascular Management of Aneurysms
		14.7.1	 Advances in Coils
		14.7.2	 Balloon-Assisted Coiling
		14.7.3	 Stent-Assisted Coiling
		14.7.4	 Flow Diverter Devices
	14.8	 Conclusions
	References
15: Microsurgery of Cerebral Aneurysms Not Amenable to Endovascular Therapy
	15.1	 Introduction
	15.2	 Operative Techniques
		15.2.1	 Choice of Operative Approach (Fig. 15.1)
	15.3	 Anterior Circulation Aneurysms
		15.3.1	 Orbitozygomatic-Pterional Approach
		15.3.2	 Interhemispheric Approach
	15.4	 Posterior Circulation Aneurysms
		15.4.1	 Orbitozygomatic Approach
		15.4.2	 Transpetrosal Approaches
		15.4.3	 Far-Lateral Approach
		15.4.4	 Combined Approaches
	15.5	 Vascular Control
	15.6	 Techniques for Clipping
		15.6.1	 Aneurysm with Hemorrhagic Presentation
		15.6.2	 Aneurysm with Ischemic Presentation (Fig. 15.8)
		15.6.3	 Aneurysm with Mass Effect as There Presentation
	15.7	 Literature Review
	15.8	 Conclusion
	References
16: Giant Intracranial Aneurysm: Flow Alteration vs Flow Diversion
	16.1	 Introduction
	16.2	 Comparison for Outcome: Endovascular Treatment vs. Surgical Bypass
		16.2.1	 Occlusion, Recurrence and Re-bleeding
		16.2.2	 Flow Diverter Stent in Posterior Circulation Giant Aneurysm
		16.2.3	 Pressure Symptoms due to Cranial Nerve Compression
		16.2.4	 Morbidity and Mortality
	16.3	 Concepts of Flow Diversion and Flow Alteration
	16.4	 Surgical Management for GIAs
		16.4.1	 Clipping with Reconstruction of Vessel Wall
		16.4.2	 Surgical Bypass
		16.4.3	 Decision Making in Surgical Bypass
		16.4.4	 Clinical Tips for Successful Surgical Bypass
		16.4.5	 Illustrated Case Examples of Surgical Bypass in GIAs
			16.4.5.1	 Bypass with Proximal Ligation
			16.4.5.2	 Trapping of Aneurysm with Bypass
	16.5	 Endovascular Treatment for GIA
		16.5.1	 Complications of Endovascular Management of GIAs
		16.5.2	 Comparison Between Management Strategies for Complications and Clinical Outcomes
	16.6	 Conclusion
	References
17: Training Protocols for Neuroendovascular Surgery
	17.1	 Introduction
	17.2	 Training Protocols
		17.2.1	 Europe
			17.2.1.1	 The Program
			17.2.1.2	 Requirements/Criteria for Trainees
				Percutaneous Treatments
				Neuroendovascular Procedures
			17.2.1.3	 Requirements/Criteria for Institutions
			17.2.1.4	 Requirements/Criteria for Faculty and the Director of the Program
		17.2.2	 USA
			17.2.2.1	 The Program
			17.2.2.2	 Requirements/Criteria for Trainees
			17.2.2.3	 Requirements/Criteria for Institutions
			17.2.2.4	 Requirements/Criteria for Faculty and the Director of the Program
		17.2.3	 India
			17.2.3.1	 The Program
			17.2.3.2	 Requirements/Criteria for Trainees
			17.2.3.3	 Requirements/Criteria for Institutions
			17.2.3.4	 Requirements/Criteria for the Program Personnel
	17.3	 Conclusions
	References