Flowable urinary bladder matrix in complex podiatric wounds: initial experience

Introduction: Podiatric wound management may be complicated by patient comorbidities and irregular wound geometries e.g. tunneling or undermining. In complex podiatric wound presentations, skin substitutes are utilized to support the SOC toward wound closure and limb salvage. Porcine-derived urinary bladder matrix (UBM) particulate and sheets have been studied in a variety of complex wounds, DFUs, VLUs, metatarsal amputation and have been associated with a pro-remodeling host immune response in support of wound closure. Recently, a flowable delivery configuration of the UBM particulate has been cleared for use with the same indications as the particulate and sheet devices, including ulcers and surgical wounds with tunneling and undermining.Methods:This three-patient report details a foot and ankle surgeon’s initial cases utilizing flowable porcine UBM. The flowable UBM device comes with a syringe preloaded with UBM particulate and an empty syringe for sterile saline followed by connection of the syringes, mixing, and deployment of the UBM as a paste through a flexible tip. Pertinent patient demographics, history, wound size, notes on device handling and application, and available early follow-up outcomes ( >/= 90days) were collected.Results:This small series documents surgeon experience and early patient outcomes in 3 cases wherein UBM flowable devices were applied in podiatric surgery cases presenting with tunneled and undermined features. Case 1. Male, 66 yo, Type II DM, PVD, osteomyelitis, and neuropoathy. Plantar 5th metatarsal diabetic wound, 3.2cmx1.9cmx2.0cm post-debridement and removal of metatarsal head. Initial wound management was performed with one application of flowable UBM followed by standard wound care. Patient reached full closure within 11 weeks.Case 2. Male, 99yo, severe PAD. Plantar 5th metatarsal pressure wound, 2.5cmx2.5cmx2.5cm post-debridement. Patient lost to follow-up at approximately 5 weeks post-treatment. Suspected closure.Case 3. Male, 41yo, Type II DM, charcot foot, obesity, PVD, toe amputations on right foot. Plantar 1st metatarsal head diabetic wound, 1.6cmx1.6cmx0.4cm post-debridement. Initial surgery May 2024.To date, initial experience with the device and its handling was positive and supported the utility of the configuration for applying UBM paste in complex geometries.Discussion: Previous studies have demonstrated the use of UBM paste in tunneling aspects of wounds in support of wound closure. Early reporting on the flowable configuration of UBM as described in this small series of complex podiatric wounds reinforces prior findings with UBM employed as a paste. This small series motivates further research on flowable UBM in podiatric wound indications complicated by tunneling and undermining.References:1. LeCheminant J, Field C. Porcine urinary bladder matrix: a retrospective study and establishment of protocol. Journal of Wound Care. 2012;21(10):476,478-480,482. 2. Underwood P, et al. Extending limb salvage after fourth and fifth transmetatarsal amputation in diabetic foot infections using ACell® Urinary Bladder Matrix. Am Surg. 2020. Epub ahead of print. doi:10.1177/0003134820973730. 3. Paige JT et al. Modulation of inflammation in wounds of diabetic patients treated with porcine urinary bladder matrix. Regen Med. 2019 May;14(4):269-277. doi: 10.2217/rme-2019-0009. Epub 2019 Apr 25. PMID: 31020913; PMCID: PMC6886567. 4. Cotler HM, Baker HB. Urinary bladder matrix devices support closure in complex sacral wounds. Wounds. 2023;35(9):E287-E289. doi:10.25270/wnds/23087