CSF Rhinorrhea: Pathophysiology, Diagnosis and Skull Base Reconstruction

Foreword
Contents
Part I
	1: Skull Base Development and Anatomy
		1.1	 Osteology of the Three Cranial Fossae
		1.2	 Ventral Portion of Anterior, Middle and Posterior Cranial Fossa
			1.2.1	 Anterior Cranial Fossa
			1.2.2	 Middle Cranial Fossa
			1.2.3	 Posterior Cranial Fossa
		1.3	 Skull Base Embryology and Development
		1.4	 Sphenoid Bone and Sinus
			1.4.1	 Sphenoid Bone and Sinus Anatomy
			1.4.2	 Endoscopic Anatomy of the Sphenoid Sinus
		References
	2: Physiology of CSF
		2.1	 Historical Review
		2.2	 Nature of CSF
		2.3	 Volume and Pressure of CSF
		2.4	 Contents and Composition of CSF
		2.5	 Functions of CSF
		2.6	 Secretion of CSF
		2.7	 Mechanism of CSF Circulation
		2.8	 Absorption of CSF
		2.9	 The New Hypothesis of Production, Circulation, and Absorption of CSF
		References
	3: Pathophysiology of Skull Base Defect and CSF Leak
		3.1	 Epidemiology of CSF Leaks
		3.2	 Etiology and Pathophysiology of CSF Leaks
			3.2.1	 Traumatic
			3.2.2	 Iatrogenic
			3.2.3	 Congenital
			3.2.4	 Neoplastic
			3.2.5	 Spontaneous
		References
Part II
	4: Clinical Presentation of CSF Rhinorrhea
		4.1	 Introduction
		4.2	 Classification
		4.3	 History
		4.4	 Physical Exam
		4.5	 Imaging Findings
		4.6	 Differential Diagnosis
		4.7	 Conclusion
		References
	5: Fluid Analysis in CSF Rhinorrhea
		5.1	 Introduction
		5.2	 CSF Physiology
		5.3	 CSF Rhinorrhea Diagnosis
		5.4	 Ring Sign
		5.5	 Glucose Testing
		5.6	 Beta-2 Transferrin
		5.7	 Beta-Trace Protein
		5.8	 Others
		5.9	 Evidence-Based Practice
		References
	6: Imaging in the Work-Up of CSF Leak
		6.1	 Introduction
		6.2	 CT
		6.3	 MR
		6.4	 Traumatic (Accidental) CSF Leak
		6.5	 Traumatic (Post-surgery) CSF Leak
		6.6	 Non-traumatic (Spontaneous) CSF Leak
		6.7	 Non-traumatic (Pathology-Related) CSF Leak
		6.8	 Post-duraplasty Imaging
		References
	7: Role of Fluorescein in the Diagnosis of CSF Leak
		7.1	 Indications of Use
		7.2	 Fluorescein and the Informed Consent
		7.3	 Metabolism of Fluorescein
		7.4	 Intrathecal Use
			7.4.1	 Set-Up
			7.4.2	 Dose
			7.4.3	 Timing
			7.4.4	 Techniques to Improve Utilization
			7.4.5	 What if Injected Pre-operatively but Not Visible?
			7.4.6	 Interpretation of False-Negative Results
			7.4.7	 Endoscopic Examination and Exploration of Potential Area
		7.5	 Topical Fluorescein
		7.6	 Pediatric Age Group and Use of Fluorescein
		7.7	 Complications
		7.8	 Conclusion
		References
	8: Diagnostic Algorithm for Cerebrospinal Fluid Leak
		8.1	 Introduction
		8.2	 Differential Diagnosis
			8.2.1	 Allergic Rhinitis
			8.2.2	 Non-Allergic Rhinitis
			8.2.3	 Other Conditions Mimicking CSF Rhinorrhea
		8.3	 Diagnostic Approach
			8.3.1	 Clinical Evaluation
			8.3.2	 Investigations
		8.4	 Summary
		References
Part III
	9: Conservative Management of CSF Leak
		9.1	 Introduction
		9.2	 Indications of Conservative Management
		9.3	 Modalities of Conservative Management
			9.3.1	 Pharmaceutical Treatment
				9.3.1.1	 Antibiotics
				9.3.1.2	 Acetazolamide
			9.3.2	 Lumbar Drain
			9.3.3	 Immunization
				9.3.3.1	 Pneumococcal Vaccine
					Pediatric Recommendations
					Adult Recommendations
				9.3.3.2	 Meningococcal and Haemophilus Vaccine
		9.4	 Risk of Meningitis During Conservative Treatment
		9.5	 Indications of Surgical Intervention
		References
	10: Traumatic CSF Leaks
		10.1	 Introduction
		10.2	 Causes of Traumatic CSF Leak
			10.2.1	 Accidental Injury
			10.2.2	 Iatrogenic Injury
		10.3	 Duration of Conservative Treatment
			10.3.1	 Conservative Management
			10.3.2	 Lumbar Drain
			10.3.3	 Acetazolamide
			10.3.4	 Inappropriate for Conservative Treatment
		10.4	 Management of ICU Patients with Skull Base Fracture
		10.5	 Risk of Meningitis
		10.6	 Prophylactic Antibiotics
		10.7	 Recognition of Intraoperative Iatrogenic CSF Leak
			10.7.1	 Risk Assessment and Prevention
			10.7.2	 Identification
		10.8	 Timing of Surgical Intervention of Iatrogenic CSF Leak
			10.8.1	 Intraoperatively
			10.8.2	 Delayed Recognition
		10.9	 Special Considerations
			10.9.1	 CSF Otorhinorrhea
			10.9.2	 Positive Pressure Ventilation
		References
	11: Spontaneous CSF Leak
		11.1	 Incidence and Demographics
		11.2	 Pathophysiology of Spontaneous CSF Leak
		11.3	 Idiopathic Intracranial Hypertension (IIH)
		11.4	 Pathophysiology of IIH
		11.5	 Relationship Between Spontaneous CSF Leak and IIH
		11.6	 Clinical Picture
		11.7	 Diagnostic Approach
		11.8	 Imaging Studies in Spontaneous CSF Rhinorrhea
		11.9	 Radiologic Findings in Spontaneous CSF Rhinorrhea
			11.9.1	 Skull Base Osteodural Defect
			11.9.2	 Meningocele/Meningoencephalocele
			11.9.3	 Signs of Increased ICP
		11.10	 Treatment of Spontaneous CSF Rhinorrhea
		11.11	 Outcome of Surgical Repair and Postoperative Management
		References
	12: Multidisciplinary Approach to CSF Leak
		12.1	 Multidisciplinary Approach to the Cerebrospinal Fluid Leak
		12.2	 Otolaryngology/Head and Neck Surgery
		12.3	 Neurosurgery
		12.4	 Neurology
		12.5	 Ophthalmology
		12.6	 Bariatric Surgery
		12.7	 Endocrine
		12.8	 Sleep Medicine
		12.9	 Conclusion
		References
Part IV
	13: History of Surgical Approaches and Techniques for Skull Base Reconstruction
		13.1	 Historical Background
		13.2	 Evolution of Materials and Techniques for Skull Base Repair
			13.2.1	 Heterologous Materials
			13.2.2	 Autologous Grafts
			13.2.3	 Pedicled Flaps
			13.2.4	 Free Revascularized Flaps
		13.3	 Future Directions
		References
	14: Operative Room Set-Up and Instrumentation
		14.1	 Introduction
		14.2	 Operative Room Set-Up and Manpower
		14.3	 Patient Position
		14.4	 Image Guidance System (IGS)
		14.5	 Prepping and Draping
		14.6	 Surgical Instruments, Devices, and Biomaterials
			14.6.1	 Special Dissectors (Intracranial Intradural)
			14.6.2	 Electrocautery Devices
			14.6.3	 Other Instruments Used for Removal of Encephalocele
			14.6.4	 Special Graft Positioning Instruments/Seekers
			14.6.5	 Set-up of the Suction During or After Positioning of the Reconstructive Material
			14.6.6	 Sealants, Hemostatic Agents, and Nasal Packing
		14.7	 Conclusion
		References
	15: Role of the Anesthesiologist
		15.1	 Introduction
		15.2	 The Need for Neuro-anesthesiologists
		15.3	 Antibiotics Administration
		15.4	 Intracranial Hypertension
		15.5	 Obesity and OSA
		15.6	 Blood Pressure Management During Surgery
		15.7	 Valsalva Maneuver
		15.8	 Emergence from Anesthesia
		15.9	 Postoperative Care
		15.10	 Enhanced Recovery After Surgery (ERAS) in Neurosurgery
		15.11	 Conclusion
		References
	16: Synthetic Materials for Skull Base Reconstruction
		16.1	 Introduction
		16.2	 Xenograft
		16.3	 Allograft
		16.4	 Alloplastic
		16.5	 Surgical Technique
		References
	17: Free Autologous Grafts
		17.1	 Free Autologous Grafts
		17.2	 Types of Autologous Grafting Materials
		17.3	 Free Mucosal Grafts
		17.4	 Fat Grafts
		17.5	 The Fat Bath-Plug Surgical Technique
		17.6	 Fascia Grafts
		17.7	 Surgical Technique of Harvesting Fascia Lata
		17.8	 Bone/Cartilage Grafts
		17.9	 Outcomes of Various Autologous Graft Materials
		17.10	 Single Layer Versus Multilayer Grafts in Skull Base Repair
		References
	18: Local Pedicled Flaps
		18.1	 Introduction
		18.2	 Hadad-Bassagasteguy Flap
		18.3	 Anterior and Posterior Ethmoidal Artery Septal Flap
		18.4	 Septal Flip-Flap
		18.5	 Bipedicled Anterior Septal Flap
		18.6	 Posterior Pedicle Inferior Turbinate Flap
		18.7	 Posterior Pedicle Middle Turbinate Flap
		18.8	 Turbinal Flap
		18.9	 Anterior Pedicle Lateral Nasal Wall Flap
		18.10	 Surgical Technique: General Aspects
		References
	19: Regional Pedicled Flaps for Skull Base Reconstruction
		19.1	 Introduction
		19.2	 Trans-frontal Pericranial Flap
		19.3	 Temporoparietal Fascia Flap
		19.4	 Occipital Flap
		19.5	 Oliver Palatal Flap
		19.6	 Facial Buccinator Flap
		19.7	 Pedicled Buccal Fat Pad Flap
		19.8	 Salpingopharyngeus Flap (Dicle Flap)
		19.9	 Conclusions
		References
	20: Free Tissue Transfer for Orbital and Skull Base Reconstruction
		20.1	 Introduction
		20.2	 Endoscopic-Assisted Skull Base Free Tissue Transfer Reconstruction
		20.3	 Orbital Reconstruction
			20.3.1	 Reconstructive Approaches to Common Orbital Defects
				20.3.1.1	 Orbital Defect with Intact Orbital Rim
				20.3.1.2	 Orbital Defect Without Orbital Rim
				20.3.1.3	 Total Maxillectomy Defect with Orbital Exenteration
		20.4	 Open Skull Base Free Flap Reconstruction
			20.4.1	 Preparation of Recipient Vessels
			20.4.2	 Pedicle Length
			20.4.3	 Defect Considerations
			20.4.4	 Flap Donor Tissue Qualities
		20.5	 Conclusions
		References
	21: Repair of Cerebrospinal Fluid Leaks of the Anterior Cranial Fossa
		21.1	 Surgical Approaches and Exposure
			21.1.1	 Frontal Sinus Wall Defect
			21.1.2	 Ethmoid Roof and Olfactory Cleft Defect
		21.2	 Reconstruction Technique
			21.2.1	 Preparation of the Defect Site
				21.2.1.1	 Resection of Meningocele/Meningoencephalocele
				21.2.1.2	 Demucosalization
				21.2.1.3	 Smoothing of Bony Margins
				21.2.1.4	 Dura Undermining
			21.2.2	 Single Layer vs. Multilayer Technique
			21.2.3	 Underlay Vs. Overlay Technique
				21.2.3.1	 Underlay Technique
				21.2.3.2	 Overlay Technique
		21.3	 Use of Supporting Materials
		21.4	 Repair of Defects Following Skull Base Resection
		References
	22: Repair of Cerebrospinal Fluid Leaks of the Middle Cranial Fossa
		22.1	 Introduction
		22.2	 Repair of Skull Base After Trans-sellar Approach for Pituitary Adenomas
			22.2.1	 Surgical Exposure (Fig. 22.1)
			22.2.2	 Graded Reconstruction Based on the Severity of the Leak
				22.2.2.1	 No Leak: Nothing Vs Surgicel Vs Gelfoam
				22.2.2.2	 Small Weeping Leak: Gelfoam Vs Fat Graft with or Without Buttress with or Without Nasoseptal Flap
				22.2.2.3	 Large Arachnoid Tear: Fat Graft or Duraform with or Without Floor Reconstruction with or Without Nasoseptal Flap
			22.2.3	 When to Consider Using a Lumbar Drain: Evidences for or Against
			22.2.4	 Intrathecal Fluorescein
		22.3	 Repair of Skull Base Defect After Transtuberculum Transplanum Approach
			22.3.1	 Surgical Exposure (Fig. 22.1, Video 22.1)
			22.3.2	 Dealing with Mucosa and Bone Around Defect
			22.3.3	 Reconstruction Technique
				22.3.3.1	 Inlay, Onlay Multilayer Closure with NS Flap
				22.3.3.2	 Button Closure with NS Flap
				22.3.3.3	 Gasket Seal Closure with NS Flap
				22.3.3.4	 Use of Fat
			22.3.4	 Evidence for and Against Use of LD
			22.3.5	 Use of Fluorescein
		22.4	 Endoscopic Repair of Sternberg’s Canal and Other Defects of the Lateral Recess of the Sphenoid Sinus
			22.4.1	 Debate About Whether It Is Really a “Sternberg Canal” Leak
			22.4.2	 Surgical Exposure: Transpterygoid Approach (Fig. 22.2, Video 22.2)
			22.4.3	 Dealing with Mucosa and Bone Around Defect
			22.4.4	 Reconstruction Technique
			22.4.5	 Correction of CSF Leaks in the Lateral Recess of the Sphenoid Sinus: Current Results
		22.5	 Limitations and Surgical Challenges of Sellar, Suprasellar, and Lateral Sphenoid CSF Leak Repair
		22.6	 Conclusions
		References
	23: Repair of Cerebrospinal Fluid Leaks of the Posterior Cranial Fossa
		23.1	 Introduction
		23.2	 CSF Leak Repair: Transclival Approach
			23.2.1	 Upper Transclival Approach
			23.2.2	 Middle/Lower Transclival Approach
		23.3	 CSF Leak Repair: Transodontoid Approach
		23.4	 Limitations and Surgical Challenges
		23.5	 Postoperative Care
		23.6	 Management of Postoperative CSF Leak
		23.7	 Literature Review
		23.8	 Conclusion
		References
	24: The Proper Use of Reconstructive Material
		24.1	 Introduction
		24.2	 Materials
			24.2.1	 Free Autografts
			24.2.2	 Synthetic Dural Grafts
			24.2.3	 Vascularised Flaps
			24.2.4	 Absorbable Sealants and Glues
			24.2.5	 Reconstructive Factors
		24.3	 Size and Site
		24.4	 Pathology
		24.5	 Conclusion
		References
	25: External Approaches for Skull Base Reconstruction
		25.1	 Introduction
		25.2	 Systematic Zone-Based Approach
			25.2.1	 Anterior Skull Base (Zone I)
			25.2.2	 Middle Fossa Skull Base Defects (Zone II)
			25.2.3	 Posterior Fossa Defects and Posterior Petrous Bone (Zone III)
		25.3	 General Concepts in External Skull Base Reconstruction
			25.3.1	 Free Grafts
			25.3.2	 Local and Regional Flaps
			25.3.3	 Microvascular Free Flaps
		25.4	 External Surgical Approaches for Skull Base Reconstruction
			25.4.1	 Subfrontal and Transbasal Approaches
				25.4.1.1	 Pericranial Flap
			25.4.2	 Temporalis Muscle Flap
				25.4.2.1	 Temporalis Muscle Flap
			25.4.3	 Transmastoid
		25.5	 Combined Endoscopic Assist External Approaches
			25.5.1	 Temporoparietal Flap Combined with Transpterygoid Approach
				25.5.1.1	 Temporoparietal Flap
			25.5.2	 Minimally Invasive Endoscopic Pericranial Flap [24]
		25.6	 Microvascular Free Flaps in Open Approaches
		25.7	 Limitations and Complications of the External Approaches
		References
Part V
	26: Postoperative Instructions
		26.1	 Introduction
		26.2	 Packing of the Surgical Field and Duration of Packing
		26.3	 General Postoperative Observation and Care
		26.4	 Imaging (CT Brain) in Early Post-op Period
		26.5	 Bed Rest
		26.6	 Head Elevation
		26.7	 Deep Venous Thrombosis Prophylaxis
		26.8	 Hospital Stay
		26.9	 Diet Restrictions
		26.10	 Drug Therapy
		26.11	 Precautions: Blowing the Nose, Lifting Heavy Objects, Leaning Forward, Sneezing, Coughing, Vomiting, Constipation, Physical Activity
		26.12	 OSA Patients and CPAP
		26.13	 Air Travel
		26.14	 Sports and Heavy Duty Jobs
		26.15	 Time Interval to Return to Normal Activity
		26.16	 Postoperative Nasal Physiology and Local Nasal Care
		26.17	 Postoperative Adjuvant Radiotherapy in Malignant Tumors
		References
	27: Surgical Complications of Skull Base Reconstruction
		27.1	 Prevention of Complications
		27.2	 Early Complications
			27.2.1	 Injury of Ethmoidal Arteries
			27.2.2	 Cranial Nerve Morbidity
			27.2.3	 Mucosal Flap Necrosis
			27.2.4	 Surgical Site Infection
			27.2.5	 Injury of Descending Palatine Nerve and Vidian Nerve During Access to Stemberg’s Canal Defect
			27.2.6	 Early Complications of Postoperative CSF Leaks
				27.2.6.1	 Chemical or Infectious Meningitis/Encephalitis
				27.2.6.2	 Pneumocephalus
				27.2.6.3	 Hydrocephalus
		27.3	 Late Complications
			27.3.1	 Brain Herniation
			27.3.2	 Anosmia/Hyposmia
			27.3.3	 Septal Perforation After Graft or Flap
			27.3.4	 Donor Site Morbidity
				27.3.4.1	 Anterolateral Thigh
				27.3.4.2	 Temporoparietal Flap
				27.3.4.3	 Pericranial Flap
			27.3.5	 Paranasal Sinus Mucocele
		References
	28: Failure of CSF Leak Repair
		28.1	 Introduction
		28.2	 Patient Factors
			28.2.1	 BMI
			28.2.2	 Elevated ICP
			28.2.3	 Other Factors
		28.3	 Etiology
			28.3.1	 Iatrogenic Leaks
			28.3.2	 Non-Iatrogenic Traumatic Leaks
			28.3.3	 Spontaneous Leaks
		28.4	 Site of CSF Leak
		28.5	 Technique
		28.6	 Adjunctive Management
		28.7	 Recurrence
		28.8	 Conclusion
		References
	29: Role of Lumbar Drain in CSF Leak Management
		29.1	 Introduction
		29.2	 Concept and Role of Lumbar Drain in CSF Leak
		29.3	 The Use of Lumbar Drain in CSF Leak
		29.4	 Indications for Lumbar Drain Placement in Skull Base Surgery
		29.5	 Contraindications of LD in Skull Base Surgery
		29.6	 LD Procedure, Precautions and Patient’s Instructions
			29.6.1	 Equipment (Fig. 29.3a)
			29.6.2	 Procedure
			29.6.3	 Management
			29.6.4	 Precautions
			29.6.5	 Removal
		29.7	 Complications of LD
		References
	30: Long-Term Follow-Up Strategy
		30.1	 Introduction
		30.2	 Intraoperative Considerations
		30.3	 Immediate Postoperative Care and ICU Management
		30.4	 Early Postoperative Care
		30.5	 Special Considerations in Patients with Spontaneous CSF Rhinorrhea
		30.6	 Frequency and Length of Follow-Up After CSF Leak Repair
		30.7	 Methods of Surveillance
			30.7.1	 Clinically
			30.7.2	 Postoperative Imaging
			30.7.3	 Neuro-Ophthalmological Evaluation
			30.7.4	 Quality of Life (QOL) Assessment
			30.7.5	 Other Methods of Surveillance
		References
	31: Cerebrospinal Fluid Rhinorrhea in Children
		31.1	 Introduction to Pediatric Cerebrospinal Fluid Leaks
		31.2	 Etiology and Pathophysiology
			31.2.1	 Congenital Etiology
			31.2.2	 Traumatic Etiology
		31.3	 Diagnostic Work-Up and Localization of CSF Leaks
		31.4	 Management of CSF Leaks in Children
			31.4.1	 Conservative Management
			31.4.2	 Surgical Treatment
			31.4.3	 Surgical Challenges in Pediatric CSF Leakage
			31.4.4	 Surgical Approaches: Intracranial Vs Endoscopic Endonasal
			31.4.5	 The Endoscopic Endonasal Approach
			31.4.6	 Materials Used for Repair
			31.4.7	 Timing of Repair of Congenital Meningoencephaloceles
			31.4.8	 Postoperative Management
		31.5	 Summary
		References
	32: Outcomes of Skull Base Reconstruction
		32.1	 Introduction
		32.2	 General Success Rates: Endoscopic Vs. Open Approaches
		32.3	 Repair Techniques
			32.3.1	 CSF Leak Flow Rate
			32.3.2	 Leak Location
			32.3.3	 Dural Defect Size
		32.4	 Inpatient Vs. Outpatient Repair of CSF Leaks
		32.5	 Prognostic Factors for Successful Repair
		32.6	 Long-Term Outcomes
		32.7	 Summary
		References
	33: Abnormal Presentation of CSF Leak
		33.1	 Unusual Presentation
		33.2	 Clival Lesion
		33.3	 Optic Nerve
		33.4	 Eustachian Tube Leakage of the Middle Skull Base
		33.5	 Distant Pseudomeningoceles of the Ventral Skull Base
		33.6	 Systemic Disease
		33.7	 Nonsurgical Iatrogenic-Induced CSF Leak
		References
	34: Management of Idiopathic Intracranial Hypertension
		34.1	 Definition
		34.2	 Terminology
		34.3	 Epidemiology
		34.4	 Associations
		34.5	 Pathogenesis
		34.6	 Diagnosis
		34.7	 Symptoms
		34.8	 Signs
		34.9	 Imaging
		34.10	 Diagnostic Lumbar Puncture
		34.11	 Management
		34.12	 Acetazolamide
		34.13	 Topiramate
		34.14	 Steroids
		34.15	 Other Medications
		34.16	 Therapeutic Lumbar Puncture
		34.17	 Surgery
		34.18	Cranial Decompression
		34.19	 Optic Nerve Sheath Fenestration
		34.20	 Shunt Surgery
		34.21	 Lumbo-Peritoneal Shunts
		34.22	 Ventriculo-Peritoneal Shunts
		34.23	 Endoscopic Repair
		34.24	 Venous Sinus Stenting
		34.25	 Weight Loss
		34.26	 Conclusion
		References
	35: Olfaction and CSF Leak
		35.1	Introduction
			35.1.1	 Cerebrospinal Fluid Rhinorrhoea and Olfaction
			35.1.2	 Head Trauma, CSF, and Olfaction
			35.1.3	 Iatrogenic
			35.1.4	 Idiopathic Intracranial Hypertension (IIH)
			35.1.5	 Tumours
		35.2	 Preventative Management
			35.2.1	 Olfactory Assessment
			35.2.2	 Imaging
			35.2.3	 Technique and Sequelae
				35.2.3.1	 Direct Trauma and Reconstruction
				35.2.3.2	 Inflammation and Obstruction
				35.2.3.3	 Evidence for Prognosis of Postoperative Olfactory Function
		References
Part VI
	36: CSF Rhinorrhea and Infection
		36.1	 Introduction
		36.2	 Pathophysiology
		36.3	 Risk Factors
			36.3.1	 CSF Leakage
			36.3.2	 Duration of the CSF Leakage
			36.3.3	 Gender, Type of Surgery, Complex Tumors, Presence of an External Ventricular Drain or Shunt
			36.3.4	 Lumbar Drain Duration
			36.3.5	 Reoperation
			36.3.6	 Increased BMI
			36.3.7	 Pneumocephalus and Diaphragmatic Defects
		36.4	 Epidemiology and Incidence of Infection in CSF Rhinorrhea
			36.4.1	 Incidence of Infection in Spontaneous CSF Rhinorrhea
			36.4.2	 Incidence and Type of Infection in Posttraumatic CSF Rhinorrhea
				36.4.2.1	 Accidental Trauma
					Meningitis
					Recurrent Meningitis
					Penetrating Injury
					Iatrogenic Trauma
				36.4.2.2	 Types of Surgery
					Endonasal Transsphenoidal Surgery
					Endonasal Transsphenoidal Surgery vs Sublabial Transsphenoidal Surgery
					Endoscopic Endonasal (EE) Versus Microscopic Transsphenoidal (MT) Versus Open Transcranial (OT) Resection of Craniopharyngiomas
		36.5	 Microbiology
			36.5.1	 Community-Acquired Pathogens
			36.5.2	 Nosocomial-Acquired Pathogens
		36.6	 Diagnosis of CNS Infections in Patient with CSF Leakage
			36.6.1	 Clinical Presentation
			36.6.2	 Physical Examination
			36.6.3	 Laboratory
				36.6.3.1	 Routine Laboratory
				36.6.3.2	 Lumbar Puncture and CSF Analysis
				36.6.3.3	 Specific CSF Diagnostic Tests
					CSF Color
					WBC Count
					CSF Glucose Concentration
					CSF Protein Concentration
					CSF Cultures
				36.6.3.4	 Gram Stain
					Latex Agglutination
					PCR
			36.6.4	 Imaging Studies
		36.7	 Medical Management of CNS Infections
			36.7.1	 Community-Acquired Meningitis
				36.7.1.1	 Duration of Therapy
				36.7.1.2	 Adjunctive Dexamethasone Therapy
				36.7.1.3	 Outpatient Antimicrobial Therapy in Patients with Bacterial Meningitis
			36.7.2	 Nosocomial Meningitis
				36.7.2.1	 Duration of Therapy
			36.7.3	 Repeated Lumbar Puncture
		36.8	 Antibiotic Prophylaxis
			36.8.1	 In Patient with Preoperative CSF Leakage
			36.8.2	 In Patient with Intra and Post- operative CSF Leakage
		36.9	 Role of Vaccination in CSF Rhinorrhea
			36.9.1	 Pneumococcal Vaccination
		References
	37: Evidence-Based Medicine in Cerebrospinal Fluid Leak and Skull Base Reconstruction
		37.1	 Evidence-Based Diagnosis of Cerebrospinal Fluid Rhinorrhea
			37.1.1	 Diagnosis
				37.1.1.1 Ring Sign
				37.1.1.2 Glucose Test
				37.1.1.3 Beta-2 Transferrin
				37.1.1.4 Beta Trace Protein
				37.1.1.5 Radionuclide Cisternography
				37.1.1.6 Other Radiologic Testing
			37.1.2	 Localization
				37.1.2.1 Radionuclide Cisternography
				37.1.2.2 Computed Tomography Scanning
				37.1.2.3 Magnetic Resonance Imaging
				37.1.2.4 Combination Studies
			37.1.3	 Intrathecal Fluorescein
		37.2	 Evidence-Based Management of CSF Rhinorrhea and Skull Base Reconstruction
			37.2.1	 Spontaneous CSF Rhinorrhea
				37.2.1.1 Weight Loss
				37.2.1.2 Acetazolamide and Shunt
			37.2.2	 Lumbar Drainage in the Management of CSF Rhinorrhea
				37.2.2.1 High-Flow Leaks
				37.2.2.2 Low-Flow Leaks
			37.2.3	 Vascularized Flap Versus Free Graft
				37.2.3.1 Large Versus Small Skull Base Defects
			37.2.4	 Non-iatrogenic Traumatic CSF Rhinorrhea
				37.2.4.1 Antibiotics
				37.2.4.2 Lumbar Drain
			37.2.5	 Antibiotics in Surgical Defects
		References
	38: Quality of Life in CSF Leak
		38.1	 Introduction
		38.2	 Measuring Quality of Life
		38.3	 Relevant Available QOL Instruments in CSF Rhinorrhea
			38.3.1	 Generic Instruments
			38.3.2	 Disease-Specific Instruments
		38.4	 Quality of Life in Endoscopic Endonasal Surgery Techniques in CSF Rhinorrhea
		38.5	 Conclusions
		References
	39: Surgical Competencies and Simulation Models in CSF Leak Repair
		39.1	 Introduction
		39.2	 The CSF Leak Simulation Model
			39.2.1	 Settings
			39.2.2	 Steps
			39.2.3	 Validation
			39.2.4	 Limitations
		39.3	 Other Models
		References
	40: Patient Advocacy and Medicolegal Issues In CSF Rhinorrhea
		40.1	 Informed Consent
		40.2	 Intraoperative Tools
		40.3	 Communication After Iatrogenic Leak
		40.4	 Legal Considerations
			40.4.1	 Logistics
			40.4.2	 Financial Considerations
			40.4.3	 Legal Outcomes by Type of Surgery
		40.5	 Conclusion
		References