瘻孔プラグと接着剤のテクニック：材料、挿入方法、臨床応用

瘻孔プラグと接着剤のテクニック：材料、挿入方法、臨床応用

Introduction

The management of anal fistulas, particularly complex ones, presents a significant challenge in colorectal surgery. These abnormal connections between the anal canal or rectum and the perianal skin often traverse significant portions of the anal sphincter complex, creating a therapeutic dilemma: achieving complete fistula eradication while preserving sphincter function and continence. Traditional approaches such as fistulotomy, which involves laying open the entire fistula tract, offer excellent healing rates but carry substantial risks of sphincter damage and subsequent incontinence when applied to complex fistulas.

Over the past two decades, there has been considerable interest in developing minimally invasive, sphincter-preserving techniques for anal fistula management. Among these innovations, fistula plugs and bioadhesive glues represent a paradigm shift in approach—rather than excising or dividing the fistula tract, these methods aim to seal or obliterate it while leaving the surrounding tissues, particularly the sphincter complex, completely intact. This approach offers the theoretical advantage of eliminating the fistula without any compromise to continence function.

Fistula plugs are bioprosthetic or synthetic devices designed to be inserted into the fistula tract, providing both a physical barrier to the internal opening and a scaffold for tissue ingrowth and tract healing. Since the introduction of the first commercially available anal fistula plug in 2006, numerous materials and designs have been developed, each with specific handling characteristics and proposed advantages. These range from decellularized porcine intestinal submucosa to synthetic bioabsorbable polymers, with various shapes and deployment mechanisms.

Bioadhesive glues, particularly fibrin sealants, represent another sphincter-preserving approach. These products, which mimic the final stages of the coagulation cascade, are injected into the fistula tract to seal it from the inside. The fibrin matrix not only provides an immediate physical seal but also potentially promotes wound healing by supporting fibroblast migration and proliferation. Various formulations and application techniques have been described, with ongoing refinements to improve outcomes.

Despite the theoretical appeal and initial enthusiasm for these approaches, clinical results have been variable, with success rates ranging from 24% to 92% in different series. This wide variation reflects differences in patient selection, technical execution, material properties, and follow-up duration. Understanding the specific characteristics of different plug and glue products, optimal insertion techniques, and appropriate patient selection is crucial for maximizing success with these methods.

This comprehensive review examines the current landscape of fistula plug and glue techniques, focusing on material properties, insertion methods, clinical outcomes, and future directions. By synthesizing the available evidence and practical insights, this article aims to provide clinicians with a thorough understanding of these sphincter-preserving options for anal fistula management.

Medical Disclaimer: This article is intended for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. The information provided should not be used for diagnosing or treating a health problem or disease. Invamed, as a medical device manufacturer, provides this content to enhance understanding of medical technologies. Always seek the advice of a qualified healthcare provider with any questions regarding medical conditions or treatments.

Fistula Plug Materials and Properties

Biological Plugs

  1. Surgisis® AFP™ (Cook Medical):
  2. Composition: Lyophilized porcine small intestinal submucosa (SIS)
  3. Structure: Layered collagen matrix with retained growth factors
  4. Configuration: Conical design with narrow end and wider button end
  5. Handling characteristics: Requires hydration before use, moderate pliability
  6. Biocompatibility: Minimal inflammatory response, gradual remodeling
  7. Degradation profile: Complete resorption in 3-6 months
  8. Regulatory status: FDA-cleared, CE marked

  9. Historical significance: First commercially available fistula plug (2006)

  10. Biodesign® Fistula Plug (Cook Medical):

  11. Evolution of Surgisis AFP
  12. Enhanced processing for improved handling
  13. Modified design with reinforced button
  14. Similar biological properties to original SIS material
  15. Available in multiple sizes and configurations
  16. Option for spiral configuration in newer versions
  17. Improved resistance to early extrusion

  18. Maintained biocompatibility profile

  19. GORE® BIO-A® Fistula Plug (W.L. Gore & Associates):

  20. Composition: Synthetic bioabsorbable polyglycolide-trimethylene carbonate copolymer (PGA:TMC)
  21. Structure: Highly porous, fibrous scaffold
  22. Configuration: Dome-shaped disk with attached bioabsorbable tubes
  23. Handling characteristics: No hydration required, excellent pliability
  24. Biocompatibility: Minimal inflammatory response, supports tissue ingrowth
  25. Degradation profile: Complete resorption in 6-7 months
  26. Design features: Multiple tubes can be used or trimmed as needed

  27. Regulatory status: FDA-cleared, CE marked

  28. Permacol™ Fistula Plug (Medtronic):

  29. Composition: Acellular porcine dermal collagen
  30. Structure: Cross-linked collagen matrix
  31. Configuration: Cylindrical plug with disc
  32. Handling characteristics: Moderate pliability, no hydration required
  33. Biocompatibility: Minimal antigenicity due to acellular nature
  34. Degradation profile: Extended presence due to cross-linking (>12 months)
  35. Resistance to enzymatic degradation

  36. Regulatory status: CE marked (limited US availability)

  37. LIFT-Plug™ (CG Bio):

  38. Composition: Porcine dermal collagen
  39. Structure: Acellular collagen matrix
  40. Configuration: Designed specifically for combined LIFT-Plug procedure
  41. Handling characteristics: Moderate pliability
  42. Biocompatibility: Similar to other acellular dermal matrices
  43. Specialized design for specific technique
  44. Limited widespread availability
  45. Newer entry to market with evolving evidence base

Synthetic and Composite Plugs

  1. Curaseal™ Fistula Plug (Tensive):
  2. Composition: Proprietary hydrogel technology
  3. Structure: Expandable hydrogel that conforms to tract shape
  4. Configuration: Injectable with in-situ expansion
  5. Handling characteristics: Liquid delivery, solid expansion
  6. Biocompatibility: Biocompatible synthetic polymer
  7. Mechanism: Physical occlusion with tissue integration
  8. Regulatory status: CE marked, limited availability

  9. Newer technology with emerging clinical data

  10. FiXcision™ Fistula Device (A.M.I.):

  11. Composition: Nitinol and silicone components
  12. Structure: Clip-based closure system
  13. Configuration: Mechanical device rather than traditional plug
  14. Handling characteristics: Requires specific deployment system
  15. Mechanism: Mechanical closure of internal opening
  16. Permanent implant (non-degradable)
  17. Limited long-term data

  18. Regulatory status: CE marked, not FDA-cleared

  19. Custom-Made Plugs:

  20. Various materials described in literature
  21. Configurations: Often fashioned from existing biomaterials
  22. Examples: Collagen sponges, fibrin-coated plugs
  23. Limited standardization
  24. Variable handling and performance characteristics
  25. Often used in research settings or resource-limited environments
  26. Lack regulatory clearance for specific fistula indication

Material Properties and Biological Interactions

  1. Porosity and Microstructure:
  2. Influence on cell migration and proliferation
  3. Effect on vascularization of implant
  4. Impact on mechanical properties
  5. Relationship to degradation rate
  6. Optimal pore size range: 100-300 μm for tissue ingrowth
  7. Interconnectivity of pores affecting cell penetration

  8. Surface topography influencing cell attachment

  9. Mechanical Properties:

  10. Tensile strength: Ability to withstand pulling forces
  11. Compression resistance: Maintaining shape under pressure
  12. Elasticity: Conforming to tract shape
  13. Suture retention strength: Important for secure fixation
  14. Resistance to extrusion forces
  15. Handling characteristics for surgical manipulation

  16. Stability in moist environment

  17. Degradation Characteristics:

  18. Hydrolytic vs. enzymatic degradation
  19. Degradation rate and tissue replacement timeline
  20. Byproducts of degradation and local tissue response
  21. Maintenance of structural integrity during healing phase
  22. Balance between degradation and tissue ingrowth
  23. Effect of cross-linking on degradation profile

  24. Variability between patients (enzyme levels, local environment)

  25. Host Response and Biocompatibility:

  26. Inflammatory response profile
  27. Foreign body reaction characteristics
  28. Immunogenicity considerations
  29. Fibrotic encapsulation vs. integration
  30. Promotion of M2 macrophage phenotype (pro-healing)
  31. Angiogenesis stimulation

  32. Growth factor interactions

  33. Antimicrobial Properties:

  34. Inherent resistance to bacterial colonization
  35. Potential for antimicrobial coating or impregnation
  36. Biofilm formation prevention
  37. Compatibility with perioperative antibiotics
  38. Performance in contaminated field
  39. Effect of local infection on material integrity
  40. Resistance to enzymatic degradation by bacterial proteases

Bioadhesive Glues for Fistula Treatment

Fibrin Sealants

  1. Tisseel® (Baxter Healthcare):
  2. Composition: Human fibrinogen, thrombin, aprotinin, calcium chloride
  3. Mechanism: Mimics final coagulation cascade steps
  4. Preparation: Two-component system requiring mixing
  5. Setting time: 3-5 minutes
  6. Handling characteristics: Controlled application with dual-chamber syringe
  7. Degradation: Complete fibrinolysis in 1-2 weeks
  8. Regulatory status: FDA-approved, CE marked

  9. Extensive clinical history in various surgical applications

  10. Evicel® (Ethicon/Johnson & Johnson):

  11. Composition: Human fibrinogen, human thrombin
  12. Distinguishing features: No aprotinin or bovine components
  13. Preparation: Two-component system
  14. Setting time: 1-2 minutes
  15. Application: Spray or drip options
  16. Degradation profile: Similar to natural fibrin clot
  17. Regulatory status: FDA-approved, CE marked

  18. Reduced immunogenicity due to all-human components

  19. BioGlue® (CryoLife):

  20. Composition: Bovine serum albumin and glutaraldehyde
  21. Mechanism: Covalent cross-linking of proteins
  22. Setting time: Begins polymerizing in 20-30 seconds, full strength in 2 minutes
  23. Handling characteristics: Single applicator, premixed components
  24. Degradation: Extended presence (>6 months)
  25. Stronger bond than fibrin sealants
  26. Regulatory status: FDA-approved for vascular sealing, off-label for fistulas

  27. Potential for inflammatory reaction due to glutaraldehyde

  28. Autologous Fibrin Glue:

  29. Composition: Patient’s own blood components
  30. Preparation: Requires blood draw and processing
  31. Advantages: No risk of disease transmission, reduced immunogenicity
  32. Limitations: Variable quality, preparation complexity
  33. Applications: Primarily in research settings or where commercial products unavailable
  34. Limited standardization
  35. Potential for growth factor enrichment
  36. Cost-effective in appropriate settings

Synthetic Adhesives and Cyanoacrylates

  1. Histoacryl® (B. Braun):
  2. Composition: n-Butyl-2-cyanoacrylate
  3. Mechanism: Rapid polymerization on contact with tissue fluids
  4. Setting time: Seconds
  5. Handling characteristics: Liquid application, requires dry field
  6. Degradation: Extended presence (months to years)
  7. Regulatory status: FDA-approved for skin closure, off-label for fistulas
  8. Strong adhesive properties

  9. Potential for inflammatory reaction

  10. Glubran®2 (GEM):

  11. Composition: N-butyl-2-cyanoacrylate and methacryloxysulfolane
  12. Modified formulation for reduced tissue reaction
  13. Setting time: 60-90 seconds
  14. Elastic properties after polymerization
  15. Bacteriostatic properties
  16. Regulatory status: CE marked for internal use
  17. Limited data specifically for anal fistulas

  18. Used more commonly in Europe

  19. DuraSeal™ (Integra LifeSciences):

  20. Composition: Polyethylene glycol (PEG) hydrogel
  21. Mechanism: Forms hydrogel barrier
  22. Setting time: 1-2 minutes
  23. Handling characteristics: Sprayable application
  24. Degradation: 4-8 weeks
  25. Regulatory status: FDA-approved for dural sealing, off-label for fistulas
  26. Expansion properties (swells after application)
  27. Limited specific data for anal fistulas

Combination Products and Emerging Technologies

  1. Plug-Glue Hybrid Approaches:
  2. Combination of physical plug with adhesive properties
  3. Examples: Fibrin-coated plugs, glue-saturated biomaterials
  4. Theoretical advantages: Mechanical and biochemical closure
  5. Limited commercial availability
  6. Primarily custom preparations
  7. Emerging research area

  8. Variable standardization

  9. Growth Factor-Enhanced Adhesives:

  10. Addition of platelet-rich plasma (PRP) to fibrin sealants
  11. Enrichment with specific growth factors (PDGF, TGF-β, etc.)
  12. Theoretical advantage: Enhanced healing promotion
  13. Preparation complexity
  14. Variable growth factor concentrations
  15. Limited standardization

  16. Emerging clinical evidence

  17. Cell-Seeded Matrices:

  18. Combination of scaffold materials with stem cells
  19. Sources: Adipose-derived, bone marrow-derived, or other mesenchymal stem cells
  20. Theoretical advantage: Active biological healing promotion
  21. Significant preparation complexity
  22. Regulatory challenges
  23. Limited clinical implementation

  24. Primarily investigational

  25. Nanoparticle-Enhanced Adhesives:

  26. Incorporation of nanoparticles for enhanced properties
  27. Examples: Silver nanoparticles (antimicrobial), ceramic nanoparticles (mechanical strength)
  28. Theoretical advantages: Targeted property enhancement
  29. Early research stage
  30. Limited clinical translation
  31. Potential for controlled drug delivery
  32. Regulatory considerations

Insertion Techniques and Procedural Considerations

Preoperative Preparation and Assessment

  1. Patient Evaluation:
  2. Detailed history of fistula symptoms and duration
  3. Previous treatments and surgeries
  4. Baseline continence assessment
  5. Evaluation for underlying conditions (IBD, diabetes, etc.)
  6. Physical examination with fistula probing
  7. Digital rectal examination

  8. Anoscopy to identify internal opening

  9. Imaging Studies:

  10. Endoanal ultrasound: Assesses sphincter integrity and fistula course
  11. MRI pelvis: Gold standard for complex fistulas
  12. Fistulography: Less commonly used
  13. 3D reconstruction for complex anatomy
  14. Assessment of secondary tracts
  15. Measurement of tract length and diameter

  16. Planning of optimal approach

  17. Preoperative Preparation:

  18. Bowel preparation (full vs. limited)
  19. Antibiotic prophylaxis
  20. Seton placement 6-8 weeks prior (controversial)
  21. Drainage of any active sepsis
  22. Optimization of medical conditions
  23. Smoking cessation
  24. Nutritional assessment and optimization

  25. Patient education and expectation management

  26. Tract Preparation Considerations:

  27. Maturation of tract (typically 6-12 weeks after acute phase)
  28. Absence of active infection
  29. Adequate drainage
  30. Consideration of tract curettage
  31. Assessment of tract epithelialization
  32. Evaluation of internal opening size
  33. Planning for tract modification if needed

Standard Fistula Plug Insertion Technique

  1. Anesthesia and Positioning:
  2. General, regional, or local anesthesia with sedation
  3. Lithotomy position most common
  4. Prone jackknife position as alternative
  5. Adequate exposure with appropriate retraction
  6. Optimal lighting and magnification

  7. Slight Trendelenburg position helpful

  8. Initial Steps and Tract Identification:

  9. Examination under anesthesia to confirm anatomy
  10. Identification of external and internal openings
  11. Gentle probing of tract with malleable probe
  12. Irrigation of tract with hydrogen peroxide or saline
  13. Assessment of tract caliber and course
  14. Confirmation of tract patency

  15. Measurement of tract length

  16. Tract Preparation:

  17. Debridement of external and internal openings
  18. Curettage of tract to remove granulation tissue
  19. Irrigation with antiseptic solution
  20. Brushing of tract (optional)
  21. Removal of epithelialized lining
  22. Hemostasis confirmation

  23. Creation of fresh wound surfaces

  24. Plug Preparation:

  25. Selection of appropriate plug size
  26. Hydration if required (e.g., SIS plugs)
  27. Trimming to appropriate length (typically 2-3 cm longer than tract)
  28. Tapered end preparation if needed
  29. Suture placement for later fixation
  30. Handling according to manufacturer’s instructions

  31. Avoidance of excessive manipulation

  32. Plug Insertion:

  33. Threading suture through plug
  34. Passage of suture from internal to external opening using probe
  35. Gentle pulling of plug through tract from external to internal opening
  36. Positioning with wider portion at internal opening
  37. Avoidance of excessive tension
  38. Confirmation of proper seating at internal opening

  39. Trimming of excess material at external opening

  40. Fixation and Completion:

  41. Secure fixation at internal opening with absorbable sutures
  42. Incorporation of surrounding tissue in sutures
  43. Avoidance of excessive tension
  44. Minimal fixation at external opening (if any)
  45. External opening left partially open for drainage
  46. Final inspection for proper positioning
  47. Documentation of procedure details

Variations and Technical Modifications

  1. Button Reinforcement Technique:
  2. Addition of a “button” of biomaterial at internal opening
  3. Suturing of plug to button for reinforcement
  4. Theoretical advantage: Reduced early dislodgement
  5. Materials: SIS, dermal matrix, or similar
  6. More extensive internal opening closure
  7. Limited comparative data

  8. Surgeon-specific modification

  9. LIFT-Plug Hybrid Technique:

  10. Combination of LIFT procedure with plug insertion
  11. LIFT procedure performed first
  12. Plug placed in external component of the tract
  13. Theoretical advantage: Addressing both components
  14. More extensive procedure
  15. Specific plug designs available

  16. Growing evidence base

  17. Dermal Advancement-Plug Technique:

  18. Combination of dermal advancement flap with plug
  19. Flap created to cover internal opening
  20. Plug inserted into tract
  21. Theoretical advantage: Dual-mechanism closure
  22. More extensive tissue manipulation
  23. Higher technical complexity

  24. Limited comparative data

  25. Modified Plug Designs and Insertion:

  26. Spiral configuration plugs
  27. Button-tail designs
  28. Customized shaping for specific anatomy
  29. Insertion direction variations
  30. Multiple plug techniques for branching tracts
  31. Surgeon-specific modifications
  32. Limited standardization

Fibrin Glue Application Techniques

  1. Standard Glue Injection Technique:
  2. Tract preparation as for plug (curettage, irrigation)
  3. Placement of suture at internal opening (optional)
  4. Catheter insertion from external opening
  5. Positioning of catheter tip at internal opening
  6. Slow withdrawal while injecting glue
  7. Complete filling of tract
  8. Closure of internal opening with suture (if placed)
  9. External compression for 1-2 minutes

  10. External opening left open for drainage of excess

  11. Internal-to-External Approach:

  12. Catheter insertion from internal opening
  13. Injection while withdrawing toward external opening
  14. Theoretical advantage: Better filling of internal opening
  15. Technical challenge: Catheter placement
  16. Less commonly performed
  17. Limited comparative data

  18. Surgeon-specific preference

  19. Scaffold-Enhanced Glue Technique:

  20. Placement of absorbable material in tract (gelatin sponge, collagen)
  21. Injection of glue to saturate scaffold
  22. Theoretical advantage: Enhanced structural support
  23. Combination of mechanical and adhesive effects
  24. Various materials described
  25. Limited standardization

  26. Emerging approach

  27. Pressure-Controlled Application:

  28. Use of specialized delivery systems
  29. Controlled pressure during application
  30. Theoretical advantage: Optimal filling without excessive pressure
  31. Equipment-dependent technique
  32. Limited availability
  33. Emerging technology
  34. Potential for reduced complications

Postoperative Care and Follow-up

  1. Immediate Postoperative Management:
  2. Typically outpatient procedure
  3. Pain management with non-constipating analgesics
  4. Monitoring for urinary retention
  5. Diet advancement as tolerated
  6. Activity restrictions guidance

  7. Wound care instructions

  8. Wound Care Protocol:

  9. Sitz baths starting 24-48 hours postoperatively
  10. Gentle cleaning after bowel movements
  11. Avoidance of harsh soaps or chemicals
  12. Monitoring for plug extrusion or displacement
  13. Signs of infection education

  14. External wound management

  15. Activity and Dietary Recommendations:

  16. Limited sitting for 1-2 weeks
  17. Avoidance of heavy lifting (>10 lbs) for 2 weeks
  18. Gradual return to normal activities
  19. High-fiber diet encouragement
  20. Adequate hydration
  21. Stool softeners as needed

  22. Avoidance of constipation and straining

  23. Follow-up Schedule:

  24. Initial follow-up at 2-3 weeks
  25. Assessment of plug retention or glue integrity
  26. Evaluation for recurrence or persistence
  27. Subsequent evaluations at 6, 12, and 24 weeks
  28. Long-term follow-up to monitor for late recurrence

  29. Continence assessment

  30. Complication Recognition and Management:

  31. Plug extrusion: Early recognition, consideration of replacement
  32. Infection: Antibiotics, possible removal of infected material
  33. Persistent drainage: Extended observation vs. intervention
  34. Pain management: Usually minimal requirements
  35. Abscess formation: Drainage while preserving plug if possible
  36. Recurrence: Evaluation for alternative approaches

Clinical Outcomes and Evidence

Success Rates and Healing

  1. Overall Success Rates for Plugs:
  2. Range in literature: 24-92%
  3. Weighted average across studies: 50-60%
  4. Primary healing rates (first attempt): 40-60%
  5. Variability based on definition of success
  6. Heterogeneity in patient selection and technique
  7. Influence of surgeon experience and learning curve

  8. Publication bias favoring positive outcomes

  9. Success Rates for Fibrin Glue:

  10. Range in literature: 10-85%
  11. Weighted average across studies: 40-50%
  12. Generally lower than plug techniques
  13. High early success with significant late recurrence
  14. Substantial heterogeneity between studies
  15. Influence of technique variations

  16. Better results in simple fistulas

  17. Short vs. Long-term Outcomes:

  18. Initial success (3 months): 60-70%
  19. Medium-term success (12 months): 40-60%
  20. Long-term success (>24 months): 35-55%
  21. Late recurrence in approximately 10-20% of initial successes
  22. Most failures occur within first 3 months

  23. Limited very long-term data (>5 years)

  24. Healing Time Metrics:

  25. Average time to healing: 6-12 weeks
  26. External opening closure: 4-8 weeks
  27. Cessation of drainage: 2-6 weeks

  28. Factors affecting healing time:

    • Tract length and complexity
    • Patient factors (diabetes, smoking, etc.)
    • Previous treatments
    • Material properties
    • Postoperative care compliance

  29. Meta-Analysis Findings:

  30. Systematic reviews show pooled success rates of 50-60% for plugs
  31. Pooled success rates of 40-50% for fibrin glue
  32. Higher quality studies tend to report lower success rates
  33. Publication bias favoring positive outcomes
  34. Significant heterogeneity in patient selection and technique
  35. Limited high-quality randomized controlled trials
  36. Trend toward lower success rates in more recent studies

Factors Influencing Success

  1. Fistula Characteristics:
  2. Tract length: Moderate length (3-5 cm) may be optimal
  3. Previous treatments: Virgin tracts more successful than recurrent
  4. Tract maturity: Well-defined tracts show better outcomes
  5. Internal opening size: Smaller openings have better outcomes
  6. Secondary tracts: Absence improves success rates

  7. Location: Posterior may have slightly better outcomes than anterior

  8. Patient Factors:

  9. Smoking: Significantly reduces success rates
  10. Obesity: Associated with technical difficulty and lower success
  11. Diabetes: Impairs healing and reduces success
  12. Crohn’s disease: Substantially lower success rates (20-40%)
  13. Age: Limited impact in most studies
  14. Gender: No consistent effect on outcomes

  15. Immunosuppression: Negative impact on healing

  16. Technical Factors:

  17. Surgeon experience: Learning curve of 15-20 cases
  18. Prior seton drainage: Controversial effect on outcomes
  19. Tract preparation: Thorough curettage may improve results
  20. Secure fixation technique: Critical for plug success
  21. Material selection: Variable impact based on specific properties
  22. Plug sizing and trimming: Appropriate sizing important

  23. Postoperative care adherence

  24. Material-Specific Factors:

  25. Plug porosity and architecture
  26. Degradation rate matching healing timeline
  27. Mechanical properties and resistance to extrusion
  28. Biocompatibility and tissue response
  29. Handling characteristics affecting placement
  30. Antimicrobial properties

  31. Cost and availability

  32. Predictive Models:

  33. Limited validated prediction tools
  34. Combination of factors more predictive than individual elements
  35. Risk stratification approaches
  36. Individualized success probability estimation
  37. Decision support for patient counseling
  38. Research need for standardized prediction models

Functional Outcomes

  1. Continence Preservation:
  2. Major advantage of plug and glue techniques
  3. Incontinence rates <1% in most series
  4. Preservation of sphincter anatomy
  5. No anatomical distortion
  6. Maintenance of anorectal sensation

  7. Preservation of rectal compliance

  8. Quality of Life Impact:

  9. Significant improvement when successful
  10. Limited data from validated instruments
  11. Comparison with baseline often lacking
  12. Improvement in physical and social functioning
  13. Return to normal activities

  14. Sexual function rarely affected

  15. Pain and Discomfort:

  16. Generally mild postoperative pain
  17. Typically resolves within 1 week
  18. Lower pain scores compared to advancement flap
  19. Minimal analgesic requirements
  20. Rare chronic pain

  21. Early return to work and activities

  22. Patient Satisfaction:

  23. High when successful (>85% satisfied)
  24. Correlation with healing outcomes
  25. Appreciation of minimally invasive nature
  26. Minimal lifestyle disruption
  27. Cosmetic outcomes generally excellent

  28. Willingness to undergo repeat procedure if needed

  29. Long-term Functional Assessment:

  30. Limited data beyond 2 years
  31. Stable functional outcomes over time
  32. No delayed deterioration in continence
  33. Rare late-onset symptoms
  34. Need for standardized long-term follow-up
  35. Research gap in very long-term outcomes

Complications and Management

  1. Plug-Specific Complications:
  2. Extrusion: Most common (5-40%)
  3. Migration: Displacement without complete extrusion
  4. Infection: Uncommon (5-10%)
  5. Abscess formation: Rare (2-5%)
  6. Persistent drainage: Common transitional finding
  7. Pain: Usually mild, standard analgesics effective

  8. Allergic reaction: Extremely rare

  9. Glue-Specific Complications:

  10. Early dissolution: Common cause of failure
  11. Extravasation: Leakage beyond tract
  12. Fragmentation: Incomplete tract filling
  13. Allergic reaction: Rare with modern formulations
  14. Infection: Uncommon (5-10%)
  15. Embolization: Theoretical risk, extremely rare

  16. Pain: Usually minimal

  17. General Complications:

  18. Bleeding: Uncommon, typically self-limiting
  19. Urinary retention: Rare, temporary catheterization if needed
  20. Local infection: Uncommon, antibiotics if indicated
  21. Recurrence: Primary concern, may require alternative approach

  22. Persistent symptoms: Evaluation for occult infection or missed tract

  23. Management of Specific Complications:

  24. Plug Extrusion:
    • Early recognition
    • Assessment of timing (early vs. late)
    • Consideration of replacement if early
    • Alternative approach if late
    • Evaluation for contributing factors
  25. Infection:
    • Antibiotics based on culture
    • Consideration of plug removal if severe
    • Drainage of any collection
    • Reassessment for future attempts

  26. Persistent Drainage:

    • Differentiation from normal healing
    • Extended observation if improving
    • Imaging if persistent beyond 4-6 weeks
    • Consideration of alternative approach if no improvement

  27. Prevention Strategies:

  28. Appropriate patient selection
  29. Meticulous surgical technique
  30. Optimization of comorbidities
  31. Smoking cessation
  32. Nutritional support when indicated
  33. Proper postoperative care
  34. Early intervention for complications

Comparative Outcomes with Other Techniques

  1. Plug vs. Fibrin Glue:
  2. Plug: Higher success rates in most studies (50-60% vs. 40-50%)
  3. Glue: Simpler application technique
  4. Plug: More durable results
  5. Glue: Lower material costs
  6. Plug: Higher risk of extrusion
  7. Glue: Higher risk of early failure

  8. Both: Excellent continence preservation

  9. Plug vs. LIFT Procedure:

  10. LIFT: Higher success rates in most studies (60-70% vs. 50-60%)
  11. Plug: Technically simpler
  12. LIFT: Lower material costs
  13. Plug: No dissection required
  14. LIFT: More extensive tissue manipulation
  15. Both: Excellent continence preservation

  16. LIFT: More postoperative pain

  17. Plug vs. Advancement Flap:

  18. Flap: Higher success rates (60-70% vs. 50-60%)
  19. Plug: Technically simpler
  20. Flap: More extensive tissue manipulation
  21. Plug: Less postoperative pain
  22. Flap: No foreign material
  23. Both: Excellent continence preservation

  24. Plug: Faster recovery

  25. Plug vs. Traditional Fistulotomy:

  26. Fistulotomy: Much higher success rates (90-95% vs. 50-60%)
  27. Plug: Superior continence preservation
  28. Fistulotomy: Simpler technique
  29. Plug: Less postoperative pain
  30. Fistulotomy: Lower cost
  31. Plug: Faster recovery

  32. Different applications based on fistula anatomy

  33. Plug vs. Cutting Seton:

  34. Seton: Higher eventual success rates (80-90% vs. 50-60%)
  35. Plug: Better continence preservation
  36. Seton: Lower material costs
  37. Plug: Shorter treatment duration
  38. Seton: Multiple visits required
  39. Plug: Single-stage procedure
  40. Different risk-benefit profiles

Future Directions and Emerging Technologies

Material Innovations

  1. Enhanced Biological Plugs:
  2. Integration of growth factors
  3. Cell-seeded matrices
  4. Antimicrobial properties
  5. Optimized degradation profiles
  6. Improved mechanical properties
  7. Enhanced resistance to extrusion

  8. Targeted bioactivity

  9. Advanced Synthetic Materials:

  10. Novel biodegradable polymers
  11. Hydrogel technologies
  12. Shape-memory materials
  13. Nanofiber scaffolds
  14. 3D-printed custom designs
  15. Self-expanding structures

  16. Stimuli-responsive materials

  17. Composite Approaches:

  18. Hybrid natural-synthetic materials
  19. Multi-layer designs with specialized functions
  20. Gradient structures mimicking tissue interfaces
  21. Core-shell architectures
  22. Reinforced biological materials
  23. Biomimetic approaches

  24. Functionally graded materials

  25. Drug-Eluting Technologies:

  26. Antibiotic-releasing plugs
  27. Anti-inflammatory agent delivery
  28. Growth factor release systems
  29. Controlled release kinetics
  30. Cell-recruitment factors
  31. Enzyme inhibitors

  32. Combination therapeutics

  33. Biofabrication Approaches:

  34. 3D bioprinting of plugs
  35. Patient-specific designs based on imaging
  36. In situ forming materials
  37. Bioactive ink formulations
  38. Hierarchical structure creation
  39. Spatially organized bioactivity
  40. On-demand manufacturing

Procedural Innovations

  1. Image-Guided Placement:
  2. Real-time ultrasound guidance
  3. Endoscopic visualization
  4. Fluoroscopic techniques
  5. Augmented reality assistance
  6. 3D navigation systems
  7. Intraoperative MRI applications

  8. Enhanced precision placement

  9. Minimally Invasive Adaptations:

  10. Specialized delivery devices
  11. Percutaneous approaches
  12. Endoscopic placement techniques
  13. Reduced tissue manipulation
  14. Outpatient-optimized procedures
  15. Local anesthesia protocols

  16. Reduced recovery time

  17. Combination Therapies:

  18. Sequential modality approaches
  19. Concurrent technique application
  20. Staged treatment protocols
  21. Complementary mechanism targeting
  22. Individualized combination selection
  23. Algorithm-based approach selection

  24. Synergistic effect optimization

  25. Biological Adjuncts:

  26. Platelet-rich plasma applications
  27. Stem cell therapy integration
  28. Growth factor enhancement
  29. Extracellular vesicle delivery
  30. Immunomodulatory approaches
  31. Microbiome manipulation

  32. Tissue engineering principles

  33. Technology-Enhanced Follow-up:

  34. Non-invasive monitoring techniques
  35. Biomarker-based healing assessment
  36. Smart materials with sensing capabilities
  37. Remote monitoring technologies
  38. Predictive analytics for failure
  39. Early intervention protocols
  40. Personalized follow-up scheduling

Research Priorities

  1. Standardization Efforts:
  2. Uniform definition of success
  3. Standardized reporting of outcomes
  4. Consistent follow-up protocols
  5. Validated quality of life instruments
  6. Consensus on technical steps
  7. Standardized classification of failures

  8. Comparative methodology frameworks

  9. Comparative Effectiveness Research:

  10. High-quality randomized controlled trials
  11. Pragmatic trial designs
  12. Long-term follow-up studies (>5 years)
  13. Cost-effectiveness analyses
  14. Patient-centered outcome measures
  15. Comparative studies between plug types

  16. Head-to-head technique comparisons

  17. Mechanism of Action Studies:

  18. Tissue-material interface characterization
  19. Healing process investigation
  20. Biomarker identification
  21. Predictors of response
  22. Failure mechanism analysis
  23. Histological outcome correlation

  24. Tissue engineering applications

  25. Patient Selection Optimization:

  26. Identification of reliable success predictors
  27. Risk stratification tools
  28. Decision support algorithms
  29. Personalized approach frameworks
  30. Machine learning applications
  31. Biomarker-based selection

  32. Precision medicine approaches

  33. Economic and Implementation Research:

  34. Cost-effectiveness analyses
  35. Resource utilization studies
  36. Technology adoption patterns
  37. Healthcare system integration
  38. Global access considerations
  39. Reimbursement strategy optimization
  40. Value-based care models

Clinical Implementation Considerations

  1. Training and Education:
  2. Structured training programs
  3. Simulation-based learning
  4. Cadaver workshops
  5. Proctorship requirements
  6. Certification processes
  7. Competency assessment tools

  8. Maintenance of skills programs

  9. Patient Selection Guidelines:

  10. Evidence-based selection criteria
  11. Risk stratification tools
  12. Shared decision-making frameworks
  13. Expectation management
  14. Alternative option discussions
  15. Individualized risk-benefit analysis

  16. Quality of life considerations

  17. Cost and Access Issues:

  18. Material cost reduction strategies
  19. Reimbursement optimization
  20. Value demonstration
  21. Global availability challenges
  22. Resource-limited setting adaptations
  23. Insurance coverage advocacy

  24. Cost-effectiveness demonstration

  25. Quality Assurance:

  26. Outcome tracking systems
  27. Benchmarking initiatives
  28. Continuous quality improvement
  29. Complication monitoring
  30. Technical standardization
  31. Best practice guidelines

  32. Registry development

  33. Ethical Considerations:

  34. Innovation vs. standard of care balance
  35. Informed consent optimization
  36. Learning curve disclosure
  37. Outcome reporting transparency
  38. Conflict of interest management
  39. Industry relationship guidelines
  40. Cost-benefit ethical frameworks

Conclusion

Fistula plugs and bioadhesive glues represent important sphincter-preserving options in the management of anal fistulas, particularly complex ones where traditional fistulotomy would carry unacceptable risks of incontinence. These approaches offer the theoretical advantage of eliminating the fistula without any compromise to sphincter function, addressing the fundamental therapeutic dilemma in complex fistula management.

The evolution of plug materials from the original porcine small intestinal submucosa to newer synthetic bioabsorbable polymers reflects ongoing efforts to optimize the balance between tissue integration, mechanical properties, and resistance to complications such as extrusion. Similarly, bioadhesive glues have progressed from simple fibrin sealants to more sophisticated formulations with enhanced durability and bioactivity. These material advances, coupled with refinements in insertion techniques and patient selection, have contributed to improved outcomes over time.

Current evidence suggests moderate success rates averaging 50-60% for plugs and 40-50% for fibrin glue, with significant variability based on patient selection, fistula characteristics, technical execution, and material properties. While these success rates are lower than traditional fistulotomy, the near-complete preservation of continence represents a significant advantage for appropriately selected patients. The risk-benefit profile makes these approaches particularly valuable for patients with complex transsphincteric fistulas, recurrent fistulas, or those with pre-existing continence issues.

Technical success depends on meticulous attention to several critical factors: appropriate patient selection, thorough tract preparation, precise placement, secure fixation (for plugs), and careful postoperative management. The learning curve is substantial, with outcomes improving significantly after surgeons gain experience with 15-20 cases. Understanding the specific characteristics of different plug and glue products is essential for optimizing their application in clinical practice.

Future directions in this field include material innovations such as enhanced biological and synthetic plugs, drug-eluting technologies, and patient-specific designs. Procedural innovations focusing on image-guided placement, minimally invasive adaptations, and combination therapies also hold promise for improving outcomes. Research priorities include standardization of outcome reporting, comparative effectiveness studies, mechanism of action investigations, and patient selection optimization.

In conclusion, fistula plugs and bioadhesive glues have established themselves as valuable components of the colorectal surgeon’s armamentarium for complex anal fistula management. Their moderate success rates combined with excellent functional preservation make them important options in the individualized approach to this challenging condition. Continued refinement of materials, techniques, patient selection, and outcome assessment will further define their optimal role in fistula management strategies.

Medical Disclaimer: This information is for educational purposes only and not a substitute for professional medical advice. Consult a qualified healthcare provider for diagnosis and treatment. Invamed provides this content for informational purposes regarding medical technologies.

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