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Porcine Acellular Collagen Matrix (PACM)

Porcine acellular collagen matrix (PACM) is a xenogeneic, biodegradable bioscaffold derived from decellularized porcine tissues — most commonly small intestinal submucosa (SIS), urinary bladder matrix (UBM), and dermis. It has been used across multiple urologic and urogynecologic applications: urethral reconstruction, pubovaginal slings for SUI, pelvic organ prolapse repair, and bladder augmentation.[1][2]

Material Science & Preparation​

Porcine organs (small intestine, bladder, or skin) are processed with hypotonic buffers, detergents (SDS, Triton X-100), and nucleases to remove cellular material while preserving the extracellular matrix architecture.[3][4] The retained collagen, glycosaminoglycans, and bioinductive growth factors drive constructive remodeling — the scaffold is degraded and replaced by host tissue via cell infiltration, neovascularization, and organized collagen deposition.[1][5]

Commercial products (current and historical):

  • Surgisis (Cook Medical) — porcine SIS.
  • Pelvisoft / Pelvicol (Bard) — porcine acellular dermal matrix (largely discontinued).
  • ACell UBM — porcine urinary bladder matrix.
  • InteXen LP — porcine acellular dermal collagen (historical).

Comparative dECM analyses show significant variability in decellularization efficacy and structural preservation across products. Porcine acellular dermal matrix and SIS generally show good collagen fiber orientation, though some SIS products retain residual nuclear bodies.[6] Human histopathology confirms outstanding biocompatibility with no foreign-body reaction or chronic inflammation.[7]

Urologic Applications​

Urethral Reconstruction (Onlay Urethroplasty)​

PACM has been used as an onlay graft for stricture repair, acting as a biological bridge for urothelial and smooth-muscle regeneration. In rabbit models with porcine bladder submucosa-derived matrix: confluent transitional cell coverage by 2 weeks, unorganized muscle fiber migration by 2 months, and organized muscle bundles by 6 months.[5] Mantovani et al. reported the first clinical porcine SIS urethroplasty with satisfactory urodynamic outcomes at 16 months.[8]

Indication scope is narrow. Acellular scaffolds work best for onlay (ventral) repairs of moderate-length strictures. For tubularized or very long defects (> 2 cm), fistula and stenosis rates rise (~20% in animal models).[2][9] Newer engineered acellular collagen tubes (TissueSpan and similar) are being developed as off-the-shelf tubular grafts; first-in-man clinical trial initiated.[10]

Urethrocutaneous Fistula Repair (Pediatric)​

PACM has been used as a splint in redo surgery for urethrocutaneous fistula after hypospadias repair. Springer / Subramaniam (n = 12 boys): 100% success with no fistula recurrence at median 2.5 years; normal uroflow and excellent cosmesis.[11]

Female Urethral Reconstruction​

Porcine UBM used for complete posterior urethral loss — successful conversion to apparently normal urethral mucosa with significant continence improvement (Ansari / Karram, case series).[12]

Bladder Augmentation​

SIS demonstrates reliable bladder regeneration in rat and canine models — regenerated tissue histologically and functionally indistinguishable from native bladder.[13][14] Clinical translation has been inconsistent, with regenerative variability tied to pig age, intestinal region, and sterilization. Newer composite scaffolds (e.g., UROGRAFT — bladder acellular matrix + collagen + cellulose) are under preclinical development as alternatives to enterocystoplasty.[15]

Urogynecologic Applications​

Pubovaginal Slings for SUI​

Short-term outcomes favorable, long-term outcomes inferior to autologous fascia or synthetic MUS:

  • Barrington (porcine dermis, Pelvicol): 85% cure at ~12 mo.[16]
  • Rutner (SIS, n = 152): 93.4% cure over 4 yr; no sling infection, erosion, or rejection.[17]
  • Giri (porcine dermis vs autologous rectus fascia at 36 mo): 54% vs 80.4% success (p = 0.009) — "porcine dermis should not be used as a substitute for rectus fascia."[18]
  • Broussard (porcine dermis, mean 62 mo): 42.9% SUI cure; most recurrences within 12 mo.[19]
  • Siracusano (SIS, median 76 mo): 69% cure — "SIS cannot offer a durable option compared to minimally invasive synthetic techniques."[20]

POP Repair​

Transvaginal repair. The landmark PROSPECT trial (n = 1,352) compared biological grafts (PACM, SIS, bovine dermal) and synthetic mesh against native-tissue repair for primary anterior or posterior compartment prolapse: at 2 years, neither mesh nor biological graft improved prolapse symptoms or QoL over native-tissue repair.[21] ACOG Practice Bulletin 214: biologic graft-augmented anterior repair has similar rates of prolapse awareness and reoperation vs native tissue; no significant difference in recurrence for porcine dermis vs native (RR 1.29; 95% CI 0.98–1.70).[22]

Sacrocolpopexy. More nuanced:

  • Culligan RCT (laparoscopic, porcine dermis Pelvisoft vs polypropylene): comparable 12-mo anatomic cure 80.7% vs 86.2% (p = 0.24).[23]
  • Deprest (~33 mo): xenograft sacrocolpopexy with more apical failures (21% vs 3%) than synthetic mesh.[24]
  • Histopathology of failed xenograft sacrocolpopexies: porcine dermal implants locally degraded but still recognizable years later; SIS implants entirely replaced by connective tissue.[25]

AUGS 2019: porcine dermis xenograft sacrocolpopexy showed efficacy similar to polypropylene mesh in one study, but Pelvisoft is no longer commercially available.[26][22]

Advantages and Limitations​

FeatureAdvantagesLimitations
BiocompatibilityNon-immunogenic; no FBR; excellent integrationResidual porcine DNA possible after some protocols
Tissue remodelingHost cell infiltration, neovascularization, organized collagenRemodeling varies with source tissue, pig age, processing
HandlingOff-the-shelf; trims and sutures easily; no donor-site morbidityLower mechanical strength than synthetic mesh
DurabilityAdequate short-term supportLong-term degradation → inferior durability vs autologous fascia or synthetic mesh, especially in load-bearing roles
ComplicationsLower extrusion/erosion than synthetic meshErosion and infection still occur; degradation-related failures

Current Status​

The clinical role of PACM has narrowed substantially over the past decade.

  • Several key products (e.g., Pelvisoft / Pelvicol) have been discontinued.
  • The 2019 FDA halt on transvaginal POP mesh targeted synthetic products, but the regulatory environment has tightened for all implantables.
  • For SUI slings: long-term data consistently show inferior durability vs autologous fascia or synthetic MUS.[18][19]
  • For POP: PROSPECT and ACOG indicate minimal benefit of biologic graft augmentation over native-tissue repair in primary transvaginal surgery.[21][22]
  • Active research: tissue-engineered acellular scaffolds — collagen-based tubular grafts and composite scaffolds, with or without stem-cell seeding — for urethral and bladder reconstruction.[10][9][15]

See also: Porcine SIS, Bovine Dermal, Decellularized ECM, Polypropylene Mesh, Autologous Rectus Fascia.

References​

1. Davis NF, McGuire BB, Callanan A, Flood HD, McGloughlin TM. Xenogenic Extracellular Matrices as Potential Biomaterials for Interposition Grafting in Urological Surgery. The Journal of Urology. 2010;184(6):2246-2253. doi:10.1016/j.juro.2010.07.038

2. Ribeiro-Filho LA, Sievert KD. Acellular Matrix in Urethral Reconstruction. Advanced Drug Delivery Reviews. 2015;82-83:38-46. doi:10.1016/j.addr.2014.11.019

3. Ward A, Morgante D, Fisher J, Ingham E, Southgate J. Translation of Mechanical Strain to a Scalable Biomanufacturing Process for Acellular Matrix Production From Full Thickness Porcine Bladders. Biomedical Materials. 2021;16(6). doi:10.1088/1748-605X/ac2ab8

4. Chai Y, Xu J, Zhang Y, et al. Evaluation of Decellularization Protocols for Production of Porcine Small Intestine Submucosa for Use in Abdominal Wall Reconstruction. Hernia. 2020;24(6):1221-1231. doi:10.1007/s10029-019-01954-4

5. Chen F, Yoo JJ, Atala A. Acellular Collagen Matrix as a Possible "Off the Shelf" Biomaterial for Urethral Repair. Urology. 1999;54(3):407-410. doi:10.1016/s0090-4295(99)00179-x

6. Kollmetz T, Castillo-Alcala F, Veale RWF, et al. Comparative Analysis of Commercially Available Extracellular Matrix Soft Tissue Bioscaffolds. Tissue Engineering Part A. 2025;31(11-12):442-455. doi:10.1089/ten.TEA.2024.0076

7. Wiedemann A, Otto M. Small Intestinal Submucosa for Pubourethral Sling Suspension for the Treatment of Stress Incontinence: First Histopathological Results in Humans. The Journal of Urology. 2004;172(1):215-218. doi:10.1097/01.ju.0000132148.56211.af

8. Mantovani F, Trinchieri A, Castelnuovo C, Romanò AL, Pisani E. Reconstructive Urethroplasty Using Porcine Acellular Matrix. European Urology. 2003;44(5):600-602. doi:10.1016/s0302-2838(03)00212-4

9. Pinnagoda K, Larsson HM, Vythilingam G, et al. Engineered Acellular Collagen Scaffold for Endogenous Cell Guidance, a Novel Approach in Urethral Regeneration. Acta Biomaterialia. 2016;43:208-217. doi:10.1016/j.actbio.2016.07.033

10. Vythilingam G, Larsson HM, Yeoh WS, et al. Off-the-Shelf Implant to Bridge a Urethral Defect: Multicenter 8-Year Journey From Bench to Bed. Urology. 2025;196:294-299. doi:10.1016/j.urology.2024.12.016

11. Springer A, Subramaniam R. Preliminary Experience With the Use of Acellular Collagen Matrix in Redo Surgery for Urethrocutaneous Fistula. Urology. 2012;80(5):1156-1160. doi:10.1016/j.urology.2012.06.058

12. Ansari S, Karram M. Two Cases of Female Urethral Reconstruction With Acellular Porcine Urinary Bladder Matrix. International Urogynecology Journal. 2017;28(8):1257-1260. doi:10.1007/s00192-016-3262-7

13. Kropp BP. Small-Intestinal Submucosa for Bladder Augmentation: A Review of Preclinical Studies. World Journal of Urology. 1998;16(4):262-267. doi:10.1007/s003450050064

14. Lin HK, Godiwalla SY, Palmer B, et al. Understanding Roles of Porcine Small Intestinal Submucosa in Urinary Bladder Regeneration: Identification of Variable Regenerative Characteristics of Small Intestinal Submucosa. Tissue Engineering Part B. 2014;20(1):73-83. doi:10.1089/ten.TEB.2013.0126

15. Pokrywczynska M, Fekner Z, Balcerczyk D, et al. Development of UROGRAFT: A Bladder Acellular Matrix-Based Composite for Advanced Cystoplasty. ACS Biomaterials Science & Engineering. 2025. doi:10.1021/acsbiomaterials.5c00700

16. Barrington JW, Edwards G, Arunkalaivanan AS, Swart M. The Use of Porcine Dermal Implant in a Minimally Invasive Pubovaginal Sling Procedure for Genuine Stress Incontinence. BJU International. 2002;90(3):224-227. doi:10.1046/j.1464-410x.2002.02850.x

17. Rutner AB, Levine SR, Schmaelzle JF. Processed Porcine Small Intestine Submucosa as a Graft Material for Pubovaginal Slings: Durability and Results. Urology. 2003;62(5):805-809. doi:10.1016/s0090-4295(03)00664-2

18. Giri SK, Hickey JP, Sil D, et al. The Long-Term Results of Pubovaginal Sling Surgery Using Acellular Cross-Linked Porcine Dermis in the Treatment of Urodynamic Stress Incontinence. The Journal of Urology. 2006;175(5):1788-1792. doi:10.1016/S0022-5347(05)01023-2

19. Broussard AP, Reddy TG, Frilot CF, Kubricht WS, Gomelsky A. Long-Term Follow-Up of Porcine Dermis Pubovaginal Slings. International Urogynecology Journal. 2013;24(4):583-587. doi:10.1007/s00192-012-1919-4

20. Siracusano S, Ciciliato S, Lampropoulou N, et al. Porcine Small Intestinal Submucosa Implant in Pubovaginal Sling Procedure on 48 Consecutive Patients: Long-Term Results. European Journal of Obstetrics, Gynecology, and Reproductive Biology. 2011;158(2):350-353. doi:10.1016/j.ejogrb.2011.06.012

21. Glazener CM, Breeman S, Elders A, et al. Mesh, Graft, or Standard Repair for Women Having Primary Transvaginal Anterior or Posterior Compartment Prolapse Surgery (PROSPECT). Lancet. 2017;389(10067):381-392. doi:10.1016/S0140-6736(16)31596-3

22. Committee on Practice Bulletins—Gynecology and American Urogynecologic Society. Pelvic Organ Prolapse: ACOG Practice Bulletin, Number 214. Obstetrics and Gynecology. 2019;134(5):e126-e142. doi:10.1097/AOG.0000000000003519

23. Culligan PJ, Salamon C, Priestley JL, Shariati A. Porcine Dermis Compared With Polypropylene Mesh for Laparoscopic Sacrocolpopexy: A Randomized Controlled Trial. Obstetrics and Gynecology. 2013;121(1):143-151. doi:10.1097/AOG.0b013e31827558dc

24. Deprest J, De Ridder D, Roovers JP, et al. Medium Term Outcome of Laparoscopic Sacrocolpopexy With Xenografts Compared to Synthetic Grafts. The Journal of Urology. 2009;182(5):2362-2368. doi:10.1016/j.juro.2009.07.043

25. Deprest J, Klosterhalfen B, Schreurs A, et al. Clinicopathological Study of Patients Requiring Reintervention After Sacrocolpopexy With Xenogenic Acellular Collagen Grafts. The Journal of Urology. 2010;183(6):2249-2255. doi:10.1016/j.juro.2010.02.008

26. American Urogynecologic Society. Pelvic Organ Prolapse. Female Pelvic Medicine & Reconstructive Surgery. 2019;25(6):397-408. doi:10.1097/SPV.0000000000000794