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Porcine Small Intestinal Submucosa (SIS)

Porcine small intestinal submucosa is a processed extracellular-matrix graft. Commercial products and experimental preparations differ in processing, layer number, dimensions and intended use. A biological scaffold does not guarantee functional tissue regeneration, freedom from inflammation, or durable support. Select the specific product and operation, rather than treating all SIS sheets as interchangeable.[1][2]

For the broader family, see Porcine Acellular Collagen Matrix.

Two different meanings of SIS

In the AUA/SUFU female stress-incontinence guideline, SIS means single-incision sling, a synthetic midurethral-sling category. Its success rates and recommendations are not evidence for small intestinal submucosa. Keep this graft material separate from those devices when reading guideline tables.[3]

Product handling and safety​

Use the package-specific instructions and local authorization. The available Cook Biodesign Surgisis urethral sling IFU, FP0007-3C, describes pubourethral support for stress incontinence associated with urethral hypermobility or intrinsic sphincter deficiency. That intended use does not establish an indication for urethral substitution, bladder augmentation, penile grafting or fistula repair. This is a versioned document; confirm the instructions supplied with the actual implant.[2]

The same IFU contraindicates use in patients with known sensitivity to porcine material and warns of infection, acute or chronic inflammation, and allergic reaction. It specifies single use without resterilization. For that sling, rehydration is at least 10 minutes in at least 50 mL of room-temperature sterile saline or lactated Ringer's solution; all layers require fixation, and suture spacing greater than 2 mm was not evaluated. Excessive tension can cause urinary retention. These details must not be transferred to another SIS configuration without checking its own instructions.[2]

There is no established universal resorption timetable or clinical rule that a particular ply count eliminates fibrosis, aneurysmal change or failure. Experimental cell infiltration, angiogenesis and muscle-marker expression are surrogate findings; they do not establish a functioning human urinary reservoir or a durable urethral lumen.[1][4]

Urethral reconstruction​

Oral mucosa remains the preferred graft when available. The EAU 2026 urethral-stricture guideline advises against cell-free tissue-engineered grafts in extensive spongiofibrosis, after failed urethroplasty, or for strictures longer than 4 cm; that recommendation is weak because the evidence is limited. It strongly advises against a tubularized graft in a single-stage repair. These are separate limitations from the narrower patient-selection signals in individual SIS studies.[5]

The most informative long-term SIS comparison is a 2024 nonrandomized propensity-matched study of 25 SIS and 25 buccal-mucosa bulbar urethroplasties, selected from an institutional database of 1,132 operations. Estimated treatment success at 13 years was 68% with SIS versus 83.4% with buccal mucosa; failure meant any subsequent treatment. Follow-up remained longer in the SIS group. The authors identified shorter strictures and no previous urethrotomy as more favorable features, but this small observational comparison does not establish equivalence or a validated selection algorithm.[6]

SIS may therefore be discussed as a selected alternative when an oral graft cannot be used, with explicit counseling about uncertain durability. Avoid presenting several reports from the same institutional experience as independent confirmations. Operative selection belongs in Urethral Reconstruction Principles.

Peyronie's disease and congenital curvature​

SIS is one of several grafts reported after tunical incision or limited excision. Current EAU guidance does not establish a best graft material; baseline erectile function, deformity, defect size and the operation itself influence outcomes. Grafting can cause erectile dysfunction, altered sensation, shortening or recurrent curvature even if the material remodels.[7]

A prospective two-center SIS series of 43 men, followed for a mean 33 months, reported complete straightening in 74.4% and satisfactory intercourse in 88.4%, including men using erectile aids. It had no randomized material comparator. A separate matched SIS-versus-collagen-fleece analysis also retained baseline erectile-function and follow-up differences, so its apparent differences in shortening should not be presented as proof of graft superiority.[8][9]

Pediatric corporal-grafting reports are small and heterogeneous. In one series of 12 boys receiving four-layer SIS, two major graft complications required surgical correction at the second stage. Other reports used different techniques and materials. This evidence does not support a universal “single-layer safe, multilayer unsafe” rule, or transferring adult Peyronie's results to hypospadias reconstruction.[10]

See the Peyronie's Disease surgical atlas for operative decisions.

Bladder and ureteral substitution​

SIS augmentation is not an established replacement for enterocystoplasty. In the long-term follow-up of 15 neurogenic-bladder patients, only nine had the expected sustained benefit at a mean 6.3 years. Two failed immediately and four lost capacity over time. Complications included reflux in five, a bladder stone in one and perforation in one. The authors specifically advised against substituting SIS for enterocystoplasty, particularly with severe upper-tract deterioration or bladder fibrosis.[11]

Early ureteral onlay and circumferential-replacement experiments were predominantly animal studies. They do not establish that a free SIS tube, or SIS onlay in a diseased human ureter, will regenerate a durable conduit. Keep investigational scaffolds distinct from established reconstructive options and from bowel-based reservoir surgery.[4]

Fistula and mesh-perforation repair​

SIS interposition has been reported in selected salvage repairs, but it supplies a scaffold rather than a vascularized flap. In 23 complicated vesicovaginal fistula repairs, 21 women were dry through six months; there was no flap comparator. A separate retrospective series of 38 women undergoing removal of perforating tape or vaginal mesh reported closure of all urinary-tract defects, but six postoperative complications occurred and 14 women later underwent stress-incontinence surgery at a mean follow-up of 37.2 months.[12][13]

These reports support feasibility in selected hands. They do not establish equivalence to Martius or omental interposition, nor do they prove that a scaffold compensates for ischemia, radiation injury or incomplete removal of problematic foreign material.

Continence and prolapse support​

Historical SIS pubovaginal-sling series have variable definitions and durability. Clinically significant inflammatory reactions have also been reported; one small 16-patient series found five intense local reactions. That selected series should not be used as a universal incidence estimate, but it contradicts a claim that SIS cannot provoke inflammation.[14]

For primary vaginal prolapse repair, the large PROSPECT randomized program found no sustained symptom benefit from adding a biological xenograft to native-tissue repair at six years. Follow-up response was about 65%, and there was no six-year examination. This informs the use of biological augmentation in that route; it is not a brand-specific SIS trial or evidence about sacrocolpopexy, fistula repair or urethroplasty.[15]

Use the operation-specific guideline and the actual implant's authorization. A favorable short series, donor-site avoidance or absence of permanent synthetic mesh is not sufficient reason to promise better continence, lower infection risk or more durable prolapse repair.

References​

  1. Cao G, Huang Y, Li K, et al. Small Intestinal Submucosa: Superiority, Limitations and Solutions, and Its Potential to Address Bottlenecks in Tissue Repair. Journal of Materials Chemistry B. 2019;7(33):5038-5055. doi:10.1039/c9tb00530g
  1. Cook Medical. Biodesign Surgisis urethral sling. Instructions for use FP0007-3C, English section. Manufacturer IFU. Verify the package-specific version.
  1. Kobashi KC, Vasavada S, Bloschichak A, et al. Updates to Surgical Treatment of Female Stress Urinary Incontinence (SUI): AUA/SUFU Guideline (2023). The Journal of Urology. 2023;209(6):1091-1098. doi:10.1097/JU.0000000000003435
  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
  1. European Association of Urology. Urethral Strictures Guidelines, 2026: Tissue Transfer. Guideline chapter.
  1. Palminteri E, Toso S, Preto M, et al. Small Intestinal Submucosa Graft Bulbar Urethroplasty Is a Viable Technique: Results Compared to Buccal Mucosa Graft Urethroplasty After Propensity Score Matching. World Journal of Urology. 2024;42(1):123. doi:10.1007/s00345-024-04795-8
  1. European Association of Urology. Sexual and Reproductive Health Guidelines, 2026: Penile Curvature, surgical treatment and graft materials. Guideline chapter.
  1. Sayedahmed K, Rosenhammer B, Spachmann PJ, et al. Bicentric Prospective Evaluation of Corporoplasty With Porcine Small Intestinal Submucosa (SIS) in Patients With Severe Peyronie's Disease. World Journal of Urology. 2017;35(7):1119-1124. doi:10.1007/s00345-016-1973-5
  1. Rosenhammer B, Sayedahmed K, Fritsche HM, et al. Long-Term Outcome After Grafting With Small Intestinal Submucosa and Collagen Fleece in Patients With Peyronie's Disease: A Matched Pair Analysis. International Journal of Impotence Research. 2019;31(4):256-262. doi:10.1038/s41443-018-0071-1
  1. Soergel TM, Cain MP, Kaefer M, et al. Complications of Small Intestinal Submucosa for Corporal Body Grafting for Proximal Hypospadias. The Journal of Urology. 2003;170(4 Pt 2):1577-1578. doi:10.1097/01.ju.0000083802.87337.af
  1. Zhang F, Liao L. Long-Term Follow-Up of Neurogenic Bladder Patients After Bladder Augmentation With Small Intestinal Submucosa. World Journal of Urology. 2020;38(9):2279-2288. doi:10.1007/s00345-019-03008-x
  1. Farahat YA, Elbendary MA, Elgamal OM, et al. Application of Small Intestinal Submucosa Graft for Repair of Complicated Vesicovaginal Fistula: A Pilot Study. The Journal of Urology. 2012;188(3):861-864. doi:10.1016/j.juro.2012.05.019
  1. Cour F, Munier P, Kaulanjan K, et al. Small Intestinal Submucosa Xenograft to Manage Lower Urinary Tract Prostheses Perforation: A New Path? International Urogynecology Journal. 2022;33(3):627-635. doi:10.1007/s00192-021-04771-5
  1. John TT, Aggarwal N, Singla AK, Santucci RA. Intense Inflammatory Reaction With Porcine Small Intestine Submucosa Pubovaginal Sling or Tape for Stress Urinary Incontinence. Urology. 2008;72(5):1036-1039. doi:10.1016/j.urology.2008.07.043
  1. Reid F, et al. PROSPECT: 4- and 6-year follow-up of a randomised trial of surgery for vaginal prolapse. International Urogynecology Journal. 2023. doi:10.1007/s00192-022-05308-0.