Anorectal Physiology: A Clinical and Surgical Perspective

Foreword 1
Foreword 2
Preface
Acknowledgments
Contents
Contributors
Editor
Authors
1: Anatomy of the Anorectal Region and Pelvic Floor
Introduction
Anatomy of the Anus and Rectum
Anal Canal Structure, Anus, and Anal Verge
Anatomic Versus Surgical Anal Canal
Anatomic Relations of the Anal Canal
Anal Sphincter Support
Muscles of the Anal Canal
Internal Anal Sphincter
External Anal Sphincter
Conjoined Longitudinal Muscle
Histology of the Anal Canal
Anorectal Spaces
Rectum
Relations of the Rectum
Fascial Relationship of the Rectum
Arterial Supply of the Rectum and Anal Canal
Venous Drainage and Lymphatic Drainage of the Rectum and Anal Canal
Innervation of the Rectum and Anal Canal
Anatomy of the Pelvic Floor
Pelvic Floor Musculature
Levator Ani
Anorectal Ring and the Anorectal Angle
Blood Supply
Collateral Circulation
Lymphatic Drainage
Innervation
Summary
References
2: Physiology of Continence and Defecation
Introduction
Anal Continence Mechanisms
Anal Sphincter Muscles
Internal Anal Sphincter Muscle
External Anal Sphincter Muscle
Puborectalis and Levator Ani Muscles
High-Pressure Zone
Anorectal Angle
Anorectal Sensitivity and rectoanal inhibitory reflex
Rectal Compliance, Tonus, and Capacity
Rectal Filling and Emptying
Colon and rectal motility and emptying and transit time
Vascular Cushions
Stool Volume and Consistency
Mechanisms of Defecation
Summary
References
3: New Concepts of Anorectal Anatomy, Physiology, and Surgery According to the Integral System
Introduction
Normal Function of Bladder and Bowel
Ligaments (Fig. 3.1)
The Vaginal “Fascia” [4]
Anatomical Significance of the PCF Fascial Attachments [4] PCF (Fig. 3.1)
Anatomical Significance of the RVF Fascial Attachments [4]
Significance of the Organ Spaces
The Muscles [4]
The Role of Smooth Muscle of the Urethra and Anus During Closure and Evacuation [1]
The Striated Muscles of the Pelvic Floor – Functional Anatomy [4]
Upper Layers
Lower Layers (Fig. 3.4) [3]
Anorectal Closure [4]
Defecation [4, 6]
Reflex Neurological Control of Bladder and Bowel Function
Peripheral Neurological Feedback Mechanisms Balance Muscle Function
Pathogenesis of Loose Ligaments
Uterosacral Ligament Laxity – A Key Element in Anorectal Dysfunction (Fig. 3.13) [4]
Perineal Body Laxity (Fig. 3.15)
Structure
Anatomical and Surgical Significance of DTP Ligaments
Perineal Body Function is Linked to USL Function
Anatomical Pathways to “Obstructive Micturition or Defecation” (Organ Emptying Problems)
The Paradox of Obstructive Defecation (ODS) and Fecal Incontinence (FI) Coexistence
Anatomical Pathway to Symptoms of Bladder and Bowel Urge Incontinence
Function of Puborectalis Muscle (“Kegel” Muscle)
Diagnosis of Damaged Ligaments
Surgery
Results of Posterior Sling Surgery Cures Pain, Bladder, and Fecal Incontinence
Summary
References
4: Clinical Evaluation of Continence and Defecation
Clinical Evaluation of Continency
Clinical Evaluation of Defecation
Terms and Definitions of the Anorectal Physiology Guidelines
Summary
References
5: Introduction to Methods of Anorectal Physiology Evaluation
Introduction
Endoanal Ultrasound
Cinedefecography
Magnetic Resonance Imaging
Anorectal Manometry
Anal Manometry Systems and Techniques
Perfusion Systems
Microtransducer Systems
Balloon Systems
High-Resolution Anorectal Manometry (HR-ARM)
Parameters Measured with Anal Manometry
Resting Anal Pressure
Squeeze (Contraction) Pressure
Anal Motility
Volumetric Measurements
Rectal Sensation
Rectal Compliance
Balloon Expulsion Test
Rectoanal Inhibitory Reflex (RAIR)
Valsalva
Neurophysiologic Examination
Electromyography
Pudendal Nerve Terminal Motor Latency
Colonic Transit Study
Single-Capsule Technique
Multiple-Capsule Technique
Summary
References
6: Specifics of Anal Manometry
Introduction
Technical Aspects
Dynamic Method
Radial or Axial Catheter
Technical Standardization
Evaluation of Manometric Parameters
Quantitative Analysis
Pressure Measurements
Rectoanal Inhibitory Reflex (RAIR)
Qualitative Analysis
Motility of the Anal Canal
Evaluation of the Quality of the Voluntary Contraction
Post-contraction Fatigue
High Pressure Zone
Symmetry/Asymmetry of Anal Canal
Evaluation of the Quality of Voluntary Contraction
Clinical Cases and Models of Reports
Case 1 (Fig. 6.12)
Report
Findings
Summary
Case 2 (Fig. 6.13)
Findings
Summary
Summary
References
7: Endoanal, Endovaginal, and Transperineal Ultrasound
Introduction
Technical Aspects
Equipment
Anorectal Ultrasound and Anatomy
Puborectalis Muscle
External Anal Sphincter
Longitudinal Muscle
Internal Anal Sphincter
Other Structures
Evaluation of Anal Incontinence
Endoanal Ultrasound
Evaluation of the Internal Anal Sphincter
Evaluation of the Pelvic Floor
Evaluation of Endometriosis and Other Cysts
Evaluation of Anal Fistula
Summary
References
8: Echodefecography: Technique and Clinical Application
Introduction
Echodefecography Technique
Scan 1 (At Rest Position Without Gel)
Scan 2 (At Rest – Straining – At Rest Without Gel)
Scan 3: The Transducer Is Positioned Proximally to the PR (Anorectal Junction)
Scan 4
Summary
References
9: Cinedefecography
Introduction
Technique
Conventional
Computed Videodefecography
Examination
Literature Review
Summary
References
10: MRI Defecography
MRI Defecography
Technical Aspects
Interpretation
Anatomy
Endopelvic Fascia
Pelvic Diaphragm
Urogenital Diaphragm
Urethra
Vagina
Anal Sphincter
MRI Findings
Pelvic Floor Reference Lines
Pubococcygeal Line
The Medial Pubic Line
Pathological Findings
Perineal Descent Syndrome
Anterior Compartment
Medial Compartment
Enterocele
Posterior Compartment
Anorectal Angle/Anal Canal/Perineal Descent
Rectocele
Paradoxical Contraction of the Puborectalis or Anismus
Intussusception
Summary
References
11: Neurophysiology of the Pelvic Floor
Introduction
Pelvic Floor Muscles
The Pelvic Diaphragm Muscles
Endopelvic Fascia
Cardinal-uterossacral Complex (Posterior and Lateral Prostatic Fascia)
Pubocervical Fascia
Rectovaginal Fascia
Mechanics of Urinary Continence and Bladder Emptying
Mechanics of Anal Continence and Rectal Emptying
Neurological Control Over the Pelvic Floor and Bladder and Bowel Function
Efferent Innervation (Motor)
Nerves of the Sympathetic Nervous System
Nerves of the Parasympathetic Nervous System
Nerves of the Somatic Nervous System
Afferent Innervation
Neurophysiology of Continence and Emptying
Summary
References
12: Electromyography and Pudendal Nerve Terminal Motor Latency
Introduction
Electromyography
Concentric EMG
Single-Fiber EMG
EMG Abnormalities
Electroneuromyography or Nerve Conduction Studies
Pudendal Nerve Terminal Motor Latency
EMG in Anal Incontinence
EMG in Anismus
Other EMG Indications
Summary
References
13: Anal Incontinence: Etiology and Clinical Treatment
Introduction
Epidemiology
Risk Factors
Etiology
Obstetric Trauma
Congenital Disease
Neurologic Conditions
Iatrogenic
Clinical Treatment
Dietary Changes
Medication Management
Stool Bulking Agents and Antidiarrheal Medications
Topical Treatments
Bowel Management Programs
Summary
References
14: Anal Incontinence: Minimally Invasive Options
Introduction
Bulking Agents
GateKeeper and SphinKeeper
Radiofrequency
Minislings
Magnetic Ring
Vaginal/Analplugs
Neuromodulation
Stem Cells
Summary
References
15: Stem Cells: The State of Cellular Therapy in Treatment of Fecal Incontinence
Introduction
Mesenchymal Stem Cells
Acute Injury and Stem Cell Treatments
Acute Injury and Treatments with an Engineered Construct
Chronic Injury and Treatment with Cell Therapy
Neo-sphincters
Human Trials
Potential Adverse Effects
Summary
References
16: Surgical Treatment of Fecal Incontinence
Introduction
Procedures for Repair of Sphincter Injury
Sphincteroplasty
Sphincter Augmentation
Injection of Bulking Agents
Anal Sling
Radiofrequency Energy Delivery
Sphincter Replacement
Graciloplasty
Magnetic Anal Sphincter (MAS)
Artificial Bowel Sphincter (ABS)
Nerve Stimulation
Sacral Neuromodulation (SNM)
Percutaneous Tibial Nerve Stimulation
Diversion
Antegrade Continence Enema (ACE)
Stoma
Future Developments
Stem Cell Therapy
Summary
References
17: Complex Procedures for Fecal Incontinence
Introduction
Muscular Neosphincter
Gluteus Maximus
Gracilis
Artificial Anal Sphincter
Anal Slings and Tapes
Simple Silicone Band
Anal Encirclement with Surgisis™
Levatorplasty
Tissue Fixation System (TFS)
Total Anorectal Reconstruction
Antegrade Colonic Enema (ACE)
Summary
References
18: Constipation
Introduction
Definition
Etiology and Pathophysiology
Slow Transit Constipation
Functional Evacuation Disorder
Structural Evacuation Disorder
Descending Perineum Syndrome
Solitary Rectal Ulcer Syndrome
Rectal Prolapse
Rectocele
Diagnosis
History
Constipation Scores
Physical Examination
Laboratory Examination
Endoscopy
Physiological Testing
Interpretation of Results
Treatment
Conservative Treatment
Behaviour and Diet
Laxatives
Osmotics (Macrogol, Polyethylene Glycol, Lactulose, etc.)
Bulk-Forming Agents (Psyllium, Ispaghul, Sterculia, Wheat Bran, etc.)
Lubricant Agents (Paraffin Oil, etc.)
Stimulant Agents (Bisacodyl, Docusate Sodium, Sennosides, etc.)
Prokinetic Agents (Prucalopride, Linaclotide, and Lubiprostone)
PRUCALOPRIDE
LINACLOTIDE
LUBIPROSTONE
Saline Local Agents (Suppositories of Sodium Bicarbonate + Potassium Acid Tartrate and Enemas of Sorbitol + Sodium Citrate)
Biofeedback
Surgical Treatment
Sacral Nerve Stimulation/Sacral Nerve Modulation (SNS/SNM)
Malone Antegrade Colonic Enema (MACE)
Segmental Colonic Resection and (Sub-)total Colectomy
Stapled Trans-anal Rectal Resection (STARR) and TRANSTAR
Intra-anal Delorme Procedure
Rectocele Resection
Laparoscopic Ventral Rectopexy With/Without Mesh Enforcement
Summary
References
19: Obstructed Defecation Syndrome
Introduction
Normal Physiology
Diagnostic Assessment
Clinical Assessment
Defecography
Anorectal Manometry
Electromyography
Ultrasound
Colonic Transit Time
Common Disorders in Patients with ODS
Nonrelaxing Pelvic Floor
Slow Transit Constipation
Rectal Procidentia
Enterocele and Vaginal Vault Prolapse
Rectocele
Nonsurgical Management of Obstructed Defecation
Pelvic Floor Exercises with Biofeedback
Surgical Management of Obstructed Defecation
Treatment of Rectal Procidentia
Ventral Rectopexy
Posterior Rectopexy
Concomitant Sacrocolpopexy and Rectopexy
Perineal Operations for Rectal Prolapse
Stapled Transanal Rectal Resection
Rectocele Repair
Pelvic Organ Prolapse Suspension
Sacral Nerve Stimulation
Subtotal Colectomy for Slow Transit Constipation
Summary
References
20: Defecation Disorders in Children and Adolescents
Introduction
Normal Functions of the Colon and Rectum
Pathophysiology of Defecation Disorders in Children
Etiology
Diagnosis
Treatment
Summary
References
21: Anal Manometry and Chagasic Colopathy
Historical Aspects of Chagas Disease
Epidemiological and Pathological Aspects of Chagasic Colopathy
Clinical Findings and Diagnosis of Chagasic Colopathy
Anorectal Manometry
Evaluation of the RAIR and Chagasic Colopathy
Rectal Capacity
Anorectal Manometry in Chagasic Patients
Anal Manometry for Chagasic Colopathy Diagnosis
Summary
References
22: New Functional Concepts of Chagas Disease
Introduction
Constipation and Dilation in the Chagasic Megacolon
Chagasic Megacolon and Internal Anal Sphincter
Constipation and Chagasic Megacolon
Dilation Versus Constipation in Chagasic Patients: A Molecular Approach
Summary
References
23: Functional Aspects of Diabetes and Collagenosis
Introduction
Manometry in Diabetes Mellitus
Manometry in Systemic Sclerosis
Summary
References
24: Solitary Rectal Ulcer Syndrome
Introduction
Pathophysiology
Presentation and Diagnosis
Treatment
Summary
References
25: Multiple Approaches for the Treatment of Rectoceles
Introduction
Anatomy
Symptomatology
Diagnosis
Medical Management
Surgical Treatment
Transvaginal Repair
Site-Specific Fascial Defect Repair Technique
Transperineal Repair
Transanal Repair
Stapled Transanal Rectal Resection (STARR)
Transabdominal Laparoscopic Rectocele Repair
Summary
References
26: Rectal Prolapse
Introduction
Symptoms
Evaluation and Diagnosis
Treatment Approaches: Nonoperative
Treatment Approaches: Perineal Approach
Anal Encirclement (Thiersch Procedure)
Mucosal Sleeve Resection (Delorme Procedure)
Perineal Rectosigmoidectomy (Altemeier Procedure)
Treatment Approaches: Abdominal
Suture Rectopexy
Resection Rectopexy
Anterior Sling Rectopexy (Ripstein Procedure)
Posterior Mesh Rectopexy (Wells Procedure)
Ventral Mesh Rectopexy
Comparison of Procedures
Altemeier Versus Delorme
Perineal Versus Abdominal Approaches
Suture Versus Resection Versus Ventral Rectopexy
Variations on Surgical Approach for Ventral Mesh Rectopexy
Variations on Mesh
Current Practice for Primary Rectal Prolapse
Recurrent Rectal Prolapse
Risk Factors for Recurrent Prolapse
Treatment of Recurrent Prolapse
Summary
References
27: Enterocele: Diagnosis and Treatment
Introduction
Diagnosis
Dynamic Evacuation Proctography (Defecography)
Dynamic Magnetic Resonance Imaging Defecography
Dynamic Transperineal Ultrasound
Cystoscopy
Treatment
Vaginal Versus Abdominal Approach for the Surgical Repair of Enterocele
Laparoscopic Versus Open Abdominal Sacrocolpopexy
Mesh/Graft Repair
Summary
References
28: Ventral Rectopexy: Indications, Surgical Considerations, and Outcomes
Introduction
The Spectrum of Rectal Prolapse
Indications
Technique
Learning Curve
Types of Meshes
Robotic-Assisted Surgery
Outcomes
Complications
External Prolapse
Internal Intussusception
Rectocele
Solitary Rectal Ulcer Syndrome
Summary
References
29: Pudendal Neuropathy and Pudendal Canal Decompression
Introduction
Surgical Anatomy of the Pudendal Nerve
The Roots of the Pudendal Nerve
Pudendal Canal (Alcock’s Canal)
Inferior Rectal Nerve
Perineal Nerve
Dorsal Nerve of the Penis or Clitoris
Perineum
Ischiorectal (Ischioanal) Fossa
Sacrotuberous Ligament
Sacrospinous Ligament
Relations
Piriformis Muscle
Variations
Neuroanatomy of Pudendal Nerve
Neurophysiology of the Pudendal Nerve
Sacral Nerve Stimulation
Pathophysiology
Pudendal Canal Syndrome and Fecal Incontinence
Diagnosis
Main Symptoms of Pudendal Canal Syndrome
Perineodynia
Anal Incontinence
Urinary Incontinence
Erectile Dysfunction Syndrome
Three Clinical Signs of the PCS (Examinations were performed in lithotomy position)
Abnormal Anal or Vulvar Sensibility
Painful Alcock’s Canal on Rectal Examination
Painful “Skin Rolling Test”
Clinical Assessment
Pudendal Nerve Terminal Motor Latency (PNTML)
Rectal Sensation Test
Rectoanal Inhibitory Reflex (RAIR)
Anorectal Manometry
Defecography
Electromyography
Treatment
Pudendal Nerve Perineal Injections (PNPI)
Results
Physical Therapy
Surgical Treatment
Surgical Techniques
Perineal Approach
Transgluteal (TG) Approach
Transischiorectal Fossa (TIR) Approach
Laparoscopic Pudendal Nerve Decompression and Transposition (LaPNDT) Approach
Summary
References
30: Anorectal and Pelvic Floor Pain Syndromes
Introduction
Anorectal and Pelvic Floor Pain Syndromes
F2. Functional Anorectal Pain
F2a. Levator Ani Syndrome
Diagnostic Criteria
F2b. Unspecified Functional Anorectal Pain
Diagnostic Criteria
F2c. Proctalgia Fugax
Diagnostic Criteria
Levator Ani Syndrome (LAS)
Unspecified Functional Anorectal Pain
Proctalgia Fugax (PF)
Other Painful Syndromes: Differential Diagnosis
Coccygodynia
Pudendal Neuralgia
Myofascial Syndrome
Piriformis Syndrome
Clinical Approach to the Pain in the Chronic Anorectal Syndromes
Summary
References
31: Neurogenic Bowel and Bladder Dysfunction
Introduction
Pathophysiology
Clinical Presentation
Classification
Supraconal Disorder: Upper Motor Neuron Bowel Syndrome or Hyperreflexic (Spastic) Bowel (Table 31.3)
Infraconal Disorder: Lower Motor Neuron Type or Areflexic (Flaccid) Bowel
Treatment
Summary
References
32: Anorectal Physiology in Low Rectal Resection Syndrome
Introduction
Physiology of Normal Bowel Function
Pathophysiology of Low Anterior Resection Syndrome
Anal Sphincter Dysfunction
Injury to the Pelvic Plexus
Impaired Anal Sensation and Disappearance of RAIR
Rectal Capacity and Compliance
Predisposing Factors for Low Anterior Resection Syndrome
Neoadjuvant Chemoradiotherapy
Level of the Anastomosis
Anastomotic Leak and Pelvic Sepsis
Summary
References
33: Treatment of the Low Anterior Resection Syndrome
Introduction
Symptoms
Risk Factors and Pathophysiology
Information and Surveillance
Diagnosis
Prerequisite Before Referral for Treatment of Major LARS
Treatment
Treatment Algorithm
Summary
References
34: Pelvic Floor Rehabilitation
Introduction
Pelvic Floor Muscles (PFM)
Levator Ani Functions
Use of Physiotherapeutical Modalities
Biofeedback Therapy
Electrical Stimulation
Transcutaneous Electrical Nerve Stimulation (TENS)
Modes of Stimulation
Conventional Mode
Acupuncture-Like TENS
Burst Mode
Brief-Intense TENS
Kinesiotherapy (PFMT)
Exercises with Vaginal Cones
Rectal Training with Balloon (RTB)
Summary
References
35: Biofeedback
Introduction
Methods and Technique
Biofeedback Results for Anal Incontinence
Results of Biofeedback for Constipation
Biofeedback Therapy for Pelvic Pain
Summary
References
36: Sacral Neuromodulation
Introduction
Technique of Sacral Neuromodulation
Classical Open Surgical Technique
Minimally Invasive Technique
Indications
Patient’s Evaluation and Impact on Gastrointestinal Physiology
Clinical Outcome
Incontinence
Incontinence and Sphincter Lesion
Constipation
Low Anterior Resection Syndrome
Complications and Troubleshooting
Impact on Anorectal Physiology
Mechanism of Action
Summary
References
37: Sacral Neuromodulation for Anorectal Dysfunction
Background of Sacral Neuromodulation for Anorectal Dysfunction
SNM Technique
Indication
Fecal Incontinence
Constipation
Contraindications
Results
Fecal Incontinence
Constipation
Mechanism of Action
Role in the Current Treatment Algorithm
Summary
References
38: Technical Aspects of Sacral Neuromodulation
Introduction
Stages of Sacral Neuromodulation
Advanced Evaluation or First Stage
Positioning and Preparation
Identifying the Third Sacral Foramen
Introducing the Tined Lead
Tunneling of the Lead
Postoperative Care
Implantation of the Internal Neurostimulator or Second Stage
Removal of the Tined Lead
Complications
Summary
References
39: Posterior Tibial Nerve Stimulation
Introduction
History
Methods of Charge Delivery
Physiological Effects of Tibial Nerve Stimulation
Clinical Efficacy and Effectiveness of TNS
General Overview
Randomised Controlled Trials (RCTS)
Observational Studies
Role of TNS in Current Clinical Practice
Summary
References
40: Pelvic Floor Dysfunction
Introduction
Etiology
Clinical and Diagnostic Evaluation
Algorithm of Symptoms According to the Integral Theory
Symptoms from the Anterior Compartment
Symptoms from the Middle Compartment
Symptoms from the Posterior Compartment
The Aging Bladder
Treatment
Pelvic Floor Rehabilitation
Hormonal Replacement
Medical Treatment
Overactive Bladder
Summary
References
Index