Injection of Cryopreserved Amniotic Membrane and Umbilical Cord Particulate for Pressure Injuries

A Retrospective Case Series

Anne T. Mancino, MD; Alison Acott MD; and Kathryn P. Brinegar APRN


Wounds. 2022;34(9):e85-e90. 

In This Article

Abstract and Introduction


Introduction: PI poses a significant burden to society. Cryopreserved AMUC has potential benefits in managing complex wounds owing to its anti-inflammatory, anti-scarring, and proregenerative properties. AMUC grafts are commonly in sheets, but also come as morselized powders that can be sprinkled or injected. The authors initially used AMUC injection in chronic PIs in March 2017.

Materials and Methods: This is a single-center, retrospective review of patients with nonhealing PIs treated with AMUC particulate between March 2017 and November 2018. Incidence of wound healing (zero wound volume with complete reepithelialization) was measured at 12, 24, 36, and 52 weeks.

Results: Review included 26 PIs (21 patients); of which, 85% were stage 4 PIs, per the NPIAP staging system. After AMUC injection, 14 PIs (54%) achieved complete wound closure at a median of 12.4 weeks (range, 5–52 weeks). Complete wound closure was observed in 7 patients (27%) at 12 weeks, 10 patients (38%) at 24 weeks, 13 patients (50%) at 36 weeks, and 14 patients (54%) at 52 weeks. One patient with vascular issues required amputation; however, no treatment-related adverse events or complications were observed.

Conclusions: These preliminary results suggest that injection of AMUC particulate may be a safe and promising treatment in promoting wound closure of difficult-to-treat PIs.


Affecting nearly 3 million people in the United States each year,PIs are a prevalent clinical problem.[1,2] Like other chronic wounds, PIs often do not progress through the orderly stages of the wound healing cascade and remain in a state of pathological inflammation.[3] It is estimated that only 43% to 50% of PIs heal.[4,5] As a result, these wounds pose significant clinical and economic challenges to both the patient and the health care system. Padula and Delarmente reported that hospital-acquired PIs alone cost more than $26 billion annually in the United States and result in an increased hospital length of stay.[6] Additionally, these wounds often affect patients' physical, social, and psychological well-being.[7–10]

The slow and often unattainable closure of PIs has prompted the development of innovative treatment modalities to improve wound healing. Cryopreserved AMUC is one potential modality that has been used for a variety of indications, including burn and complex wound dressings, owing to its anti-inflammatory, anti-scarring, and proregenerative properties.[11–13] Although AMUC grafts are more commonly used in the sheet configuration that is applied as a dressing over wounds,[11,12,14,15] AMUC also comes in morselized particulate powders that can be sprinkled or injected.[13] Published data are limited, but a recent case series demonstrated complete healing in 5 chronic foot and ankle wounds treated with a single dose of AMUC particulate within 5 weeks in patients with medical conditions (smoking, arthritis, gout, and hypertension).[13]

Patients included in the current case series were treated for PIs in both the outpatient and long-term care settings. Many of these patients live in rural areas and have difficulty traveling, resulting in issues with irregular follow-up visits after graft placement and episodes of graft being discarded by outside providers. AMUC particulate offers the advantages of providing more surface area for biological interaction, the ability to penetrate deeper in the recipient site, and no potential for graft dislodgement. The particulate can also be stored in the clinic at room temperature. For these reasons, the authors' institution started using AMUC injection in the clinic as a treatment for chronic PIs in March 2017. To evaluate the safety and effectiveness of these injections, a retrospective chart review of these cases was conducted.