Urinary Bladder Matrix Devices Support Closure in Complex Sacral Wounds

Sacral wounds present a challenging geometry and anatomy for management and are often further complicated by underlying patient comorbidities. Diversion of the bowel and creation of an ostomy can allow for a more ideal environment for wound healing but can come with distinct challenges for the patient and surgeon. Advanced management strategies geared toward tunneled or undermined wounds and suitable for use over exposed bone may support wound closure for complicated sacral wounds. Porcine-derived UBM particulate and sheets have been studied for use in a variety of complex wounds and found to be associated with an amenable host response for wound closure.^1-3 UBM devices offer a tunable approach for complicated wound geometries and may be used in tunneled or undermined wounds and in wounds with exposed avascular structures. The objective of this retrospective case series was to assess the rate of wound area and volume change during management of complex sacral wounds with UBM devices. 

The authors retrospectively assessed 5 cases wherein UBM was utilized for management of sacral wounds further complicated by patient comorbidities, tunneling aspects of the wound, and/or exposed bone. Management entailed thorough debridement coupled with serial applications of UBM devices. UBM particulate (MicroMatrix, Integra LifeSciences) and UBM sheets (Cytal 2-layer Wound Matrix, Integra LifeSciences) were applied concomitantly and covered with a nonadherent primary dressing followed by surgical lubricant, bolstered with an absorptive pad, and covered with an absorptive foam secondary dressing. The particulate was mixed with saline to create a paste for use in tunneling aspects of wounds when necessary. All wounds were managed with NPWT for the first 6 weeks of management except for case 3 in which NPWT was utilized intermittently for the first 5 months of care. 

Wound area and depth were measured at each follow-up visit. Wound volume was estimated by multiplying the area by the depth. Wounds were managed and followed at Atlantic Surgical Group until the tunneling closed and the wounds were more superficial in nature. For these patients, continued wound care to closure occurred either at home, in a long-term care setting, or was achieved surgically in collaboration with the plastic surgery department.

The series included 3 males and 2 females (age range, 51–88 years) (Table). Comorbidities and pertinent history included osteomyelitis, diabetes, chronic obstructive pulmonary disease, end-stage renal disease, respiratory failure, cardiac arrest, and dementia. The devices applied and the number of applications were recorded with the number of applications ranging from 2 to 6. Wound dimensions were taken at initial presentation and over the course of management. The initial wound volume range was 160 cm³ to 5400 cm³ with tunnels ranging in length from 3 cm to 15 cm. The length of time from first to last wound measurement ranged from 8.7 to 43.5 weeks. Wound volume reduction ranged from 18.1 cm³ to 549.1 cm³ per week. When measured as percentage change per week, volume reduction ranged from 2.3% to 11.3%. Wound progression images for patient cases 2, 3, and 4 are shown in Figures 1, 2, and 3, respectively. All wounds progressed toward closure with diminished wound area and depth over time and with evidence of new tissue deposition.

The management of sacral wounds is often challenged by the risk of contamination as well as irregularities of the wound bed, including the presence of tunneling. Advanced wound management strategies involving skin substitutes offer an alternative for cases in which a diverting ostomy is a consideration and wherein conservative management approaches have not been successful. Medical devices utilized in these presentations must be capable of conforming to tortuous wound surface geometries. 

In this 5-patient case series, UBM particulate and sheet devices were used in the management of complex sacral wounds. These devices are intended for use in a variety of partial-thickness and full-thickness wounds, including tunneling and undermined wounds as described in the current cases of complex sacral wounds.⁴ The use of the devices in this series supported progression toward closure, including resolution of the tunneling aspects of wounds in all cases described. 

The limitations of this small retrospective data collection include the low number of cases and that the cases were overseen by a single surgeon at a single site. 

Expedited closure of tunnels in sacral wounds and mitigating the need for life-altering surgical interventions, such as the creation of an ostomy, stand to benefit the patient’s quality of life. Albeit a small cohort, review of these cases highlights the utility of UBM devices to facilitate closure for complex wounds further complicated by tunneling. Additional research is needed to robustly quantify the clinical impact of UBM devices for management of sacral wounds and other challenging wounds with tunneling or undermining.