Preserving Tissue & Limb Function: An Unusual Podiatric Wound

For more than 4 million patients in the United States who are living with chronic wounds,¹ preserving tissue is a critical goal.¹  However, preserving function is too often overlooked as another important aim of limb salvage. Diabetic foot ulcers (DFUs) and other complex wounds have become all-too-common in this country. Yet, each wound remains unique in its own right and individually challenging to care for due to the differences that can exist among patients — such as lifestyle, demographics, and comorbidities. Some wounds stand out as truly challenging for wound care providers, and it tends to be those specifically rare wounds that can teach us the most about the “typical” wounds that we’ve become accustomed to. This article will share insight on the treatment of a chronic wound with an etiology of unusual and dramatic origin in a patient cared for at an outpatient clinic in Smyrna, GA. The care plan revolved around the use of cryopreserved umbilical cord (cUC) grafts — NEOX^® CORD 1K (Amniox Medical Inc, Atlanta, GA) — a wound allograft that is produced from native fetal tissue obtained from elective C-section births. This case underscores the importance of functional preservation in achieving the ultimate goal of restoring the patient’s quality of life. 

Versatile Wound Healing

Cryopreservation of umbilical cord maintains its innate biological properties, which promote tissue regeneration while reducing scarring and inflammation. Think of cUC as a type of surgical software that reprograms cells in the body in a way that encourages normal regenerative wound healing. DFUs, which affect as many as one in four people living with diabetes during their lifetime, represent the largest group of candidates for cUC.² This therapy can also be employed for complications of chronic venous insufficiency, another common complication among wound care patients that causes blood to pool in the veins of the lower extremities and can produce skin sores. Patients with leg ulcers related to less-common conditions such as sickle cell anemia and pyoderma gangrenosum are also candidates for cUC, as are those with wounds associated with burns, trauma, and surgery. Several studies, including this author’s research, demonstrate the effectiveness of cUC in the treatment of chronic wounds of the lower extremities. One such study involved a retrospective chart review of 29 patients with chronic DFUs (32 total wounds) cared for in an outpatient facility. The average initial area was 10.6 cm² for all wounds included. Complete epithelialization was achieved in 28 of 32 patients (for an overall healing rate of 87.5%). The average time to wound closure was about 14 weeks (median of nine weeks), and an average of 1.68 applications of cUC per patient were required.³ Interestingly, two other concurrent studies of cUC for treatment of chronic wounds of the foot and ankle demonstrated similar success. One found complete healing in 51 of 64 wounds (healing rate of 79.7%) while another study that evaluated somewhat larger wounds (average area of 15.6 cm) reported complete closure in 78.8% of treated wounds.^4,5 These healing rates compare very favorably to the 25%-40% achieved by most other modalities used to treat DFUs. 

An Unusual Case

The role of therapies such as cUC in achieving the goals of improved patient functionality and quality of life is dramatically illustrated in the case presented her involving a 59-year-old female patient with a rather uncommon condition — bilateral gangrene of the feet. The patient, a dedicated runner with no previous major health problems, had been previously administered routine care. However, after she reported symptoms of neck pain, fever, and chills, a medical evaluation indicated that she had contracted bacterial meningitis, likely through exposure to and inhalation of a pathogen during a home renovation project that she had worked on with her husband. She developed pneumococcal bacteremia and septic shock, which led to a snowball effect of unfortunate sequelae. She subsequently suffered a stroke and cardiac arrest, and her mitral valve required replacement due to colonization of bacteria. Treatment of the septic shock required administration of the vasopressor norepinephrine (Levophed), which causes constriction of peripheral blood vessels. An unfortunate side effect of this life-saving therapy is transient ischemia, which ultimately led to the development of gangrene in both feet. Prior to the outpatient wound clinic, the patient had been admitted into a long-term acute care (LTAC) facility, where she was intubated and placed in a medically induced coma. Although patients with severe disease of the lower extremities are often referred for below-knee amputation, given that advances in prosthetic technology may offer superior quality of life compared to limb salvage,⁶ an opportunity was seen in this patient to preserve a significant amount of functional tissue and allow for a continued active lifestyle. 

The patient underwent bilateral open transmetatarsal amputations in October 2016. Bone and soft tissue cultures were obtained along with bone biopsies, and negative pressure wound therapy (NPWT) was then applied to enhance healing. The resulting wound on the right foot measured 10 cm x 8 cm x 2 cm; the wound on the left foot measured 12 cm x 9 cm x 2 cm — both with probing to bone. A clean surgical margin from the bone was noted, but soft tissue was positive for methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus infections. Intravenous antibiotics and hyperbaric oxygen therapy were administered at the LTAC. The cUC tissue was applied to both wounds four weeks post-surgery using PROLENE^® (Ethicon Inc., Somerville, NJ) polypropylene suture to secure the graft. One week later, the patient was discharged from the LTAC and received a second bilateral application of cUC at eight weeks. A third application followed at 13 weeks post-surgery, at which time a bilateral percutaneous Achilles tendon lengthening was conducted to reduce equinus following the amputation and attempt to restore heel strike during the stance phase of the gait cycle. A fourth application of cUC followed at 18 weeks. 

The foot was completely healed at 22 weeks post-surgery. The left foot required one final application of the cUC at 25 weeks and eventually achieved complete closure, with the patient able to walk soon after. At the time of this writing, she wears shoes with partial prosthetic fillers and her ambulation has steadily improved. She has said that her goal is to walk in the 2019 Peachtree Road Race in Atlanta on July 4.

Summary

This presented case proved to be atypical in several ways. The patient’s wound etiology was unusual, of course, and one or two applications of cUC are usually adequate. Yet, this dramatic example demonstrates the benefit that these allografts can offer in the care of complex wounds and the preservation of limb function. Other modalities, such as NPWT, play important roles in healing chronic wounds, but cUC confers rapid tissue regeneration that is capable of covering deep structures, promoting healing from the inside out, and producing supple, sustainable tissue.n

Allen Raphael is director of the Atlanta Reconstructive Surgery and Limb Salvage Fellowship Program, Smyrna, GA, and a podiatrist at Village Podiatry Centers in Atlanta. He is also a consultant for Amniox Medical.

1. Pourmoussa A Gardner DJ, Maxwell BJ, Wong AK. An update and review of cell-based wound dressings and their integration into clinical practice. Ann Transl Med. 2016;4(23):457. 
2. Rice JB, Desai U, Cummings AK, Birnbaum HG, Skornicki M, Parsons NB. Burden of diabetic foot ulcers for medicare and private insurers. Diabetes Care. 2014;37(3):651-8. 
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4. Couture M. A single-center, retrospective study of cryopreserved umbilical cord for wound healing in patients suffering from chronic wounds of the foot and ankle. Wounds. 2016;28(7):217-25.
5. Caputo WJ, Vaquero C, Monterosa A, et al. A retrospective study of cryopreserved umbilical cord as an adjunctive therapy to promote the healing of chronic, complex foot ulcers with underlying osteomyelitis. Wound Repair Regen. 2016;24(5):885-93.
6. Brown BJ, Attinger CE. The below-knee amputation: to amputate or palliate? Adv Wound Care (New Rochelle). 2013;2(1):30-5.