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Artificial Bladder: Filling the VoidArtificial Bladder: Filling the Void
Alexander Kutikov, MD(talk prepared in 2002, reviewed in 2011)
Alexander Kutikov, MD(talk prepared in 2002, reviewed in 2011)
Bladder Regeneration: Overview Bladder Regeneration: Overview
• Introduction
• Use of GI Segments
• Approaches to Bladder Replacement•Alloplastic Bladders
• Tissue Engineered Bladders• In-Situ Regenerated • In-Vitro Regenerated
• Summary
• Introduction
• Use of GI Segments
• Approaches to Bladder Replacement•Alloplastic Bladders
• Tissue Engineered Bladders• In-Situ Regenerated • In-Vitro Regenerated
• Summary
Introduction: Bladder DiseaseIntroduction: Bladder Disease
• 400 Million Suffer from Bladder Dz Cancer Trauma Infection Inflammation Iatrogenic Injuries Congenital Anomalies
• Many Require Bladder Replacement
• 400 Million Suffer from Bladder Dz Cancer Trauma Infection Inflammation Iatrogenic Injuries Congenital Anomalies
• Many Require Bladder Replacement
Current TreatmentCurrent Treatment
• Bladder replacement w/ GI segments• > 100 year-old method• Remains the standard of care
• Bladder replacement w/ GI segments• > 100 year-old method• Remains the standard of care
Problems w/ Using BowelProblems w/ Using Bowel
GI Tissue - Designed to Absorb SolutesGU Tissue - Designed to Excrete SolutesGI Tissue - Designed to Absorb Solutes
GU Tissue - Designed to Excrete Solutes
==
Compliations of GI Neo-Bladders Compliations of GI Neo-Bladders
• Altered Electrolyte Metabolism• Altered Hepatic Metabolism• Abnormal Drug Metabolism• Infection• Calculus Formation• Nutritional Disturbances• Growth Retardation• Osteomalacia• Cancer
• Altered Electrolyte Metabolism• Altered Hepatic Metabolism• Abnormal Drug Metabolism• Infection• Calculus Formation• Nutritional Disturbances• Growth Retardation• Osteomalacia• Cancer
Ideal Bladder SubstituteIdeal Bladder Substitute
• Adequate Urine Storage• Complete Evacuation of Urine (volitional)• Preserve Renal Function
• Biocompatible• Resistant to Urinary Encrustation• Resistant to Bacterial Infection
• Adequate Urine Storage• Complete Evacuation of Urine (volitional)• Preserve Renal Function
• Biocompatible• Resistant to Urinary Encrustation• Resistant to Bacterial Infection
Must be superior to GI segments
Approaches to Bladder SubstitutionApproaches to Bladder Substitution
• Alloplastic Bladders
• Tissue Engineered Bladders• In-Situ Regenerated • In-Vitro Generated
• Alloplastic Bladders
• Tissue Engineered Bladders• In-Situ Regenerated • In-Vitro Generated
Alloplastic OrgansAlloplastic Organs
Alloplastic OrgansAlloplastic Organs
Alloplastic BladderAlloplastic Bladder
• First prosthetic bladder reported in 1960• Box-shaped silicone reservoir attached to anterior abdominal wall• Silicone tube brought out onto the skin served as outlet• Hydronephrosis due to ureteral prosthetic anastomosis main reason for failure• No dog survived more than 1 month
• First prosthetic bladder reported in 1960• Box-shaped silicone reservoir attached to anterior abdominal wall• Silicone tube brought out onto the skin served as outlet• Hydronephrosis due to ureteral prosthetic anastomosis main reason for failure• No dog survived more than 1 month
Alloplastic Bladder: Mayo Clinic ModelAlloplastic Bladder: Mayo Clinic Model
Rigid polysulfone shell
Distensible silicone shell
8 Fr siliconetubes in ureters
Fluid
• Implanted intraperitoneally• No dog survived > 10 wks
• Infections w/ abscess formation *• Urinary leaks at anastomoses *• Mechanical failure of device*• Urinary encrustation • Formation of constrictive capsule • RF 2o to Hydronephrosis
• Infections w/ abscess formation *• Urinary leaks at anastomoses *• Mechanical failure of device*• Urinary encrustation • Formation of constrictive capsule • RF 2o to Hydronephrosis
Alloplastic Bladder: Reasons for FailureAlloplastic Bladder: Reasons for Failure
* - Applies to Mayo Clinic Model* - Applies to Mayo Clinic Model
Alloplastic Bladder: Aachen ModelAlloplastic Bladder: Aachen Model
Subcutaneous compressiblereservoirs
Dacron-covered silicone tubesthrough renal parenchyma
Y-shaped Dacron-reinforcedsilicone reservoir drains intourethra
7 years to develop7 years to develop
Alloplastic Bladder: Aachen ModelAlloplastic Bladder: Aachen Model
• Implanted into 5 sheep
• Functioned effectively in 2 sheep for 18 mo
• Urinary leakage in 3 animals due to anastamotic
or material failure
• Kidney structure and function preserved in all
cases
• No further publications on use of Aachen Model
since 1996
• Implanted into 5 sheep
• Functioned effectively in 2 sheep for 18 mo
• Urinary leakage in 3 animals due to anastamotic
or material failure
• Kidney structure and function preserved in all
cases
• No further publications on use of Aachen Model
since 1996
Alloplastic Bladder: Lessons LearnedAlloplastic Bladder: Lessons Learned
• Minimize anastomoses btwn living tissue and alloplasts Transrenal-parenchymal insertion of urteral prosthesis
offers hope
• Infection is a major hurdle to overcome Antibiotic-coated solid materials under investigation
• Minimize anastomoses btwn living tissue and alloplasts Transrenal-parenchymal insertion of urteral prosthesis
offers hope
• Infection is a major hurdle to overcome Antibiotic-coated solid materials under investigation
TISSUE ENGINEERING: potential solution to both problems
Use of living cells to restore, maintain, or
enhance tissues or organs
Use of living cells to restore, maintain, or
enhance tissues or organs
Tissue Engineering: DefinitionTissue Engineering: Definition
Tissue Engineering: PrinciplesTissue Engineering: Principles
1. Implantation of freshly isolated or cultured cells
2. In Situ tissue regeneration
3. Implantation of tissues assembled in vitro from
cells and scaffolds
1. Implantation of freshly isolated or cultured cells
2. In Situ tissue regeneration
3. Implantation of tissues assembled in vitro from
cells and scaffolds
Strategies for Treatment of Diseased/Injured Tissue: Strategies for Treatment of Diseased/Injured Tissue:
Tissue Engineering: PrinciplesTissue Engineering: Principles
1. Implantation of freshly isolated or cultured cells
2. In Situ tissue regeneration
3. Implantation of tissues assembled in vitro from
cells and scaffolds
1. Implantation of freshly isolated or cultured cells
2. In Situ tissue regeneration
3. Implantation of tissues assembled in vitro from
cells and scaffolds
Strategies for Treatment of Diseased/Injured Tissue: Strategies for Treatment of Diseased/Injured Tissue:
Tissue Engineering: In Situ RegenerationTissue Engineering: In Situ Regeneration
Tissue Engineering: In Situ RegenerationTissue Engineering: In Situ Regeneration
Tissue Engineering: In Situ RegenerationTissue Engineering: In Situ Regeneration
Tissue Engineering: In Situ RegenerationTissue Engineering: In Situ Regeneration
Tissue Engineering: In Situ RegenerationTissue Engineering: In Situ Regeneration
Tissue Engineering: In Situ RegenerationTissue Engineering: In Situ Regeneration
Tissue Engineering: In Situ RegenerationTissue Engineering: In Situ Regeneration • Numerous Materials Have been Tried as
Matrices
• Most Successful:
• Small bowel submucosa• Acellular submucola of porcine small bowel
• Bladder Acellular Matrix Grafts (BAMG)• Acellular collagen and elastin produced
by stripping stromal and epithelial cells
from bladder wall
• Numerous Materials Have been Tried as
Matrices
• Most Successful:
• Small bowel submucosa• Acellular submucola of porcine small bowel
• Bladder Acellular Matrix Grafts (BAMG)• Acellular collagen and elastin produced
by stripping stromal and epithelial cells
from bladder wall
Tissue Engineering: In Situ RegenerationTissue Engineering: In Situ Regeneration
7 mo post
Distended NormalBladder
S/p hemicystectomyof dome
BAMG graftedbladder
Tissue Engineering: In Situ RegenerationTissue Engineering: In Situ Regeneration
B/f Surgery S/p Surgery 7 mo s/p Surgery
Tissue Engineering: In Situ RegenerationTissue Engineering: In Situ Regeneration
Histology a/f 4 monthsHistology a/f 4 months
Tissue Engineering: In Situ RegenerationTissue Engineering: In Situ Regeneration
• Bladder wall structurally and functionally
nearly identical to native bladder • No significant rejection of graft seen
• Bladder wall structurally and functionally
nearly identical to native bladder • No significant rejection of graft seen
• Similar results obtained with SIS and BAMG grafts • Similar results obtained with SIS and BAMG grafts
• Human trials with BAMG and SIS being attempted• Human trials with BAMG and SIS being attempted
Tissue Engineering: PrinciplesTissue Engineering: Principles
1. Implantation of freshly isolated or cultured cells
2. In Situ tissue regeneration
3. Implantation of tissues assembled in vitro
1. Implantation of freshly isolated or cultured cells
2. In Situ tissue regeneration
3. Implantation of tissues assembled in vitro
Strategies for Treatment of Diseased/Injured Tissue: Strategies for Treatment of Diseased/Injured Tissue:
Tissue Engineering: In Vitro AssemblyTissue Engineering: In Vitro Assembly
Tissue Engineering: In Vitro AssemblyTissue Engineering: In Vitro Assembly
Tissue Engineering: In Vitro AssemblyTissue Engineering: In Vitro Assembly
Tissue Engineering: In Vitro AssemblyTissue Engineering: In Vitro Assembly
Tissue Engineering: In Vitro AssemblyTissue Engineering: In Vitro Assembly
SMOOTH MUSCLE
UROTHELIUM
Tissue Engineering: In Vitro AssemblyTissue Engineering: In Vitro Assembly
• Potential for genetic/phenotypic screeing of harvested cells allows selection against transformed phenotypes • Potential for genetic/phenotypic screeing of harvested cells allows selection against transformed phenotypes
Tissue Engineering: In Vitro AssemblyTissue Engineering: In Vitro Assembly
• Potential for genetic/phenotypic screening of harvested cells allows selection against transformed phenotypes
• Cells could also be genetically modified to acquire desired properties (e.g. antimicrobial, growth factors, etc.)
• Potential for genetic/phenotypic screening of harvested cells allows selection against transformed phenotypes
• Cells could also be genetically modified to acquire desired properties (e.g. antimicrobial, growth factors, etc.)
Tissue Engineering: In Vitro AssemblyTissue Engineering: In Vitro Assembly
Bx to implant of graft = 5 weeks
Tissue Engineering: In Vitro AssemblyTissue Engineering: In Vitro Assembly
Tissue Engineering: In Vitro AssemblyTissue Engineering: In Vitro Assembly
Native bladder wall
Native bladder wall
Tissue-engineeredNeo-bladder
Tissue-engineeredNeo-bladder
Tissue Engineering: In Vitro AssemblyTissue Engineering: In Vitro Assembly
• Function of Tissue Engineered Neo-Bladder:
• Mean bladder capacity was 95% of precystecomy volume
• Mean compliance was no different than preoperative values
• Function of Tissue Engineered Neo-Bladder:
• Mean bladder capacity was 95% of precystecomy volume
• Mean compliance was no different than preoperative values
SummarySummary
• GI Segments: employed as neobladders >100 years; it’s time for change.
• Alloplastic Neobladders: little hope w/ current materials.
• Tissue Engineering: hold much hope, but remains experimental. Human studies humbling to date.
• GI Segments: employed as neobladders >100 years; it’s time for change.
• Alloplastic Neobladders: little hope w/ current materials.
• Tissue Engineering: hold much hope, but remains experimental. Human studies humbling to date.