Mini-Review: Tendon-Exposed Wound Treatments

BACKGROUND

Tendon-exposed wounds are complex injuries with challenging reconstructions and no unified treatment mode. Furthermore, insufficient tissue volume and blood circulation disorders affect healing, which increases pain for the patient and affects their families and caretakers.

REVIEW

As modern medicine advances, considerable progress has been made in understanding and treating tendon-exposed wounds, and current research encompasses both macro-and micro-studies. Additionally, new treatment methods have emerged alongside the classic surgical methods, such as new dressing therapies, vacuum sealing drainage combination therapy, platelet-rich plasma therapy, and live-cell bioengineering.

CONCLUSIONS

This review summarizes the latest treatment methods for tendon-exposed wounds to provide ideas and improve their treatment.

Stem cell and tissue engineering approaches in pressure ulcer treatment

CONTEXT

Pressure ulcers or injuries, arise from ischemic damage to soft tissues induced by unrelieved pressure over a bony prominence. They are usually difficult to treat with standard medical therapy and often they recur. In the search for better treatment options, promising alternative forms of treatment are today emerging. Within the field of regenerative medicine, ongoing research on advanced therapies seeks to develop medicinal products based on gene therapy, somatic cell therapy, tissue-engineering and combinations of these.

OBJECTIVE

The main objective is to perform an overview of experimental and clinical developments in somatic cell therapy and tissue engineering targeting the treatment of pressure injuries.

METHODS

Searching terms as "PRESSURE ULCER", "STEM CELL THERAPY", "TISSUE ENGINEERING" or "WOUND HEALING" were used in combination or alone, including publications refered to basic and clinical research and focusing on articles showing results obtained in a clinical context. A total of 80 references are cited, including 23 references published in the 3 last years.

RESULTS

The results suggest that this form of treatment could be an interesting option in patients with difficult-to-treat ulcers as spinal cord injury patients.

CONCLUSION

This field of regenerative medicine is very broad and further research is warranted.

Initial Clinical Outcomes Using Umbilical Cord-Derived Tissue Grafts to Repair Anovaginal Fistula

BACKGROUND

Perianal fistula is a debilitating disease and challenging condition to treat. Recently, the use of stem cells has been shown to improve healing of fistulas.

OBJECTIVE

The aim was to examine the use of an umbilical cord-derived stem cell graft in a pilot study as a novel scaffold/stem inlay implanted into fistula repairs for anovaginal fistula to examine healing rates.

DESIGN

This was a pilot study.

SETTINGS

This study took place in a colorectal surgery practice.

PATIENTS

Patients with anovaginal fistula consented to participate. Cryopreserved umbilical cord tissue graft with viable cells was incorporated as an inlay using a previously reported technique by the authors. Demographic data including history of previous repairs and IBD were included. All patients were followed for a minimum of 6 weeks.

MAIN OUTCOME MEASURES

The primary measures were safety and efficacy of novel stem cell graft in the treatment of anovaginal fistula.

RESULTS

From September 2017 to September 2019, 15 patients underwent anovaginal fistula repair. Three of these patients underwent a second repair, for a total of 18 repairs. No patient was intentionally diverted, but 3 patients presented for repair with a preexisting stoma. The majority of repairs were previous repair failures (12; 67%), and 7 repairs were performed on 5 patients with IBD. Median follow-up was 30 (6-104) weeks. The safety profile for cryopreserved umbilical cord tissue graft was excellent as no adverse events occurred. Overall complete healing rate was 39%, and 12 (67%) repairs resulted in improvement of symptoms.

LIMITATIONS

This was a small pilot study.

CONCLUSIONS

This is the largest series using cryopreserved umbilical cord graft for anovaginal fistula repair. The use of umbilical cord was safe and effective at closing defects. Randomized studies are necessary to determine added benefits over current standard of care. See Video Abstract at http://links.lww.com/DCR/B896 .

RESULTADOS CLNICOS INICIALES DEL USO DE INJERTOS DE TEJIDO DERIVADO DE PLACENTA PARA REPARACIN DE FSTULAS ANOVAGINALES

ANTECEDENTES:La fístula perianal es una enfermedad debilitante y una afección difícil de tratar. Recientemente, se ha demostrado que el uso de células madre mejora la curación de las fístulas.OBJETIVO:Deseamos examinar el uso de un injerto de células madre derivadas de cordón umbilical en un estudio piloto como una nueva matriz/injerto de células madre implantado en reparaciones de fístula para fístula anovaginal para examinar las tasas de curación.DISEÑO:Este fue un estudio piloto.ESCENARIO:Este estudio se llevó a cabo en una clínica de cirugía colorrectal.PACIENTES:Se obtuvo consentimiento informado de pacientes con fístula anovaginal. El injerto de tejido de cordón umbilical criopreservado con células viables se incorporó como incrustación utilizando una técnica previamente informada por los autores. Se incluyeron datos demográficos que incluían antecedentes de reparaciones previas y enfermedad inflamatoria intestinal. Todos los pacientes fueron seguidos durante un mínimo de 6 semanas.PRINCIPALES MEDIDAS DE RESULTADO:Las principales medidas fueron la seguridad y la eficacia del nuevo injerto de células madre en el tratamiento de la fístula anovaginal.RESULTADOS:Desde 9/2017-9/2019, 15 pacientes fueron sometidas a reparación de fístula anovaginal. Tres de estos pacientes fueron sometidos a una segunda reparación, para un total de 18 reparaciones. Ningún paciente fue derivado intencionalmente mientras que 3 pacientes se presentaron para reparación con un estoma preexistente. La mayoría de las reparaciones fueron fallas de reparaciones previas (12, 67%) y se realizaron siete reparaciones en 5 pacientes con enfermedad inflamatoria intestinal (EII). La mediana de seguimiento fue de 30 semanas (6-104). El perfil de seguridad del injerto de tejido de cordón umbilical criopreservado fue excelente ya que no se produjeron efectos adversos. La tasa general de curación completa fue del 39% y 12 (67%) reparaciones dieron como resultado una mejoría de los síntomas.LIMITACIONES:Este fue un pequeño estudio piloto.CONCLUSIÓNES:Ésta es la serie más grande de utilización de injerto de cordón umbilical criopreservado para la reparación de una fístula anovaginal. La utilización del cordón umbilical resultó segura y eficaz para cerrar defectos. Se necesitan estudios aleatorizados para determinar los beneficios adicionales sobre el estándar de atención actual. Consulte Video Resumen en http://links.lww.com/DCR/B896 . (Traducción-Dr. Jorge Silva Velazco ).

Advancements in cell-based therapies for the treatment of pressure injuries: A systematic review of interventional studies

The high recurrence and complications associated with severe pressure injuries (PI) necessitate the exploration of advanced treatments, such as cell-based therapies, to facilitate wound healing. Such techniques harness the ability of different cell types to promote angiogenesis, re-epithelialization of the skin, and tissue regeneration. This systematic review explores the efficacy of cell-based therapies and tissue engineering in treating deep PI. We searched for interventional studies using cells in the treatment of PI in adults in four online libraries (PubMed, Embase, Ovid Medline, and Cochrane; latest search 10th June 2023). We found one randomized clinical trial (RCT), two non-RCT, and three pre-post studies, comprising 481 study participants with PI (253 intervention/228 controls). The risk of bias was categorized as moderate due to minimal bias in outcome measurements, or high owing to unclear patient randomization methods, as assessed by the ROBINS-I, NIH, and RoB-2 tools. Four cell types were identified in the context of cell-based therapies of PI: bone marrow mononuclear stem cells (BM-MNCs, n = 2); hematopoietic derived stem cells (HSC, n = 1); macrophages and activated macrophage suspensions (AMS, n = 2); and cryopreserved placental membrane containing viable cells (vCPM, n = 1). Wound healing outcomes were observed in patients undergoing cell-based therapies, including complete wound closure (AMS, vCPM; n = 142), faster healing rate (BM-MNCs, AMS; n = 146), improved granulation tissue formation (HSC, n = 3) and shorter hospitalization time (BM-MNCs; n = 108) compared to standard of care, with no adverse reactions. PI healing rate decreased only in one study with BM-MNC therapy, compared to control (n = 86). Based on the available data, though with limited evidence, it seems that macrophage deployment showed the most favorable outcomes. The results indicate that cell-based therapies offer a potential avenue for enhancing wound healing and tissue repair in PI; however, more extensive research is needed in this domain.

The healing dynamics of non-healing wounds using cryo-preserved amniotic membrane

We evaluated the effect of the application of cryo‐preserved amniotic membrane on the healing of 26 non‐healing wounds (18 patients) with varying aetiologies and baseline sizes (average of 15.4 cm²), which had resisted the standard of care treatment for 6 to 456 weeks (average 88.8 weeks). Based on their average general responses to the application of cryo‐preserved AM, we could differentiate three wound groups. The first healed group was characterised by complete healing (100% wound closure, maximum treatment period 38 weeks) and represented 62% of treated wounds. The wound area reduction of at least 50% was reached for all wounds in this group within the first 10 weeks of treatment. Exactly 19% of the studied wounds responded partially to the treatment (partially healed group), reaching less than 25% of closure in the first 10 weeks and 90% at maximum for extended treatment period (up to 78 weeks). The remaining 19% of treated wounds did not show any reaction to the AM application (unhealed defects). The three groups have different profiles of wound area reduction, which can be used as a guideline in predicting the healing prognosis of non‐healing wounds treated with a cryo‐preserved amniotic membrane.

Management of a complex scalp defect with cryopreserved placental membrane containing viable cells resulted in rapid wound closure

Reconstructive methods are most commonly used to treat scalp defects. However, patients with complex defects are often not good candidates for surgical procedures due to the severity of the wound, advanced patient age, and multiple comorbidities. In these instances, alternative nonsurgical advanced therapies should be considered.

Wound Closure Outcomes Suggest Clinical Equivalency Between Lyopreserved and Cryopreserved Placental Membranes Containing Viable Cells

Objective: To evaluate the clinical outcomes of lyopreserved placental membrane containing viable cells (vLPM) in the treatment of nonhealing wounds of various etiologies, and to compare them to those previously reported for cryopreserved placental membrane containing viable cells (vCPM).

Approach: Patients with nonhealing wounds who qualified to receive advanced wound therapies were consecutively enrolled and treated weekly with vLPM plus standard of care (SOC) at five centers. Data were de-identified and retrospectively analyzed. Outcomes included closure, time to closure, number of vLPM applications, and adverse events (AEs).

Results: Seventy-eight patients with 98 wounds (41 diabetic foot ulcers [DFUs], 19 venous leg ulcers [VLUs], 10 surgical, and 28 others) with an average size of 13.3 cm² and 8.7 months duration were treated. Fifty-eight of the 98 wounds (59.2%) achieved complete closure with median time to closure of 63 days and 6 vLPM applications. The closure by wound etiology was 63% for DFUs, 47% for VLUs, 70% for surgical wounds, and 57% for other types of wounds. Similar closure rates have been previously demonstrated for vCPM. Wound duration was the main predictor of closure: 65.8% versus 30.0% (p = 0.004) closure was achieved for wounds of ≤12 and >12 months duration, respectively. There were no AEs related to vLPM application.

Innovation: This is the first multicenter case series evaluating the clinical outcomes of vLPM in a real-world setting.

Conclusion: These results support clinical equivalency between the two placental membrane formulations with the added convenience of room-temperature storage for vLPM, allowing it to be used in any wound-care setting.

A multicenter, randomized, single-blind trial comparing the efficacy of viable cryopreserved placental membrane to human fibroblast-derived dermal substitute for the treatment of chronic diabetic foot ulcers

Randomized controlled clinical trials, the gold standard to determine treatment efficacy against control, have demonstrated advantages of skin substitutes for the treatment of chronic diabetic foot ulcers in comparison to standard of care. However, randomized controlled clinical trials comparing efficacy between two or more skin substitutes are very limited. With growing numbers of new skin substitutes, such studies are essential for treatment and policy-making decisions by wound care providers and payers. In this study, we analyzed clinical outcomes and product cost between a viable cryopreserved placental membrane (vCPM) and a human fibroblast-derived dermal substitute (hFDS) for the treatment of chronic diabetic foot ulcers in a prospective, multicenter, single-blind study. The outcomes of 62 patients were analyzed: 31 patients in the vCPM treatment group and 31 patients in the hFDS treatment group. Utilizing a non-inferiority trial design and the established treatment regimen of 8 applications for hFDS, we demonstrated that vCPM was not inferior to hFDS for the proportion of patients achieving complete wound closure (9.68, 90% CI: [10.67, 28.94]). However, preliminary findings show that vCPM may have better outcomes for wounds ≤ 5 cm² : 81.3% (13/16) of wounds in the vCPM group vs. 37.5% (6/16) of wounds in the hFDS group reached complete closure at the end of treatment (p = 0.0118). A preliminary product cost analysis for wounds ≤ 5 cm² may show significant savings for patients treated with vCPM. Average per-patient costs during the course of treatment were $3,846 and $7,968 (p < 0.0001) for vCPM and hFDS patients, respectively. These results may be used as guidance to wound care providers and payers.

Viable placental allograft as a biological dressing in the clinical management of full-thickness thermal occupational burns: Two case reports

RATIONALE

Occupational burn injuries can be detrimental and difficult to manage. The majority of complex cases are referred and managed at regional burn centers where access to specialized care is available. As an alternative to hospitalization with staged surgical procedures, placental products may be used for outpatient medical management of these common burn injuries, especially if access to a regional burn center is limited or restricted.Fresh amnion has been a treatment of choice in burns for more than 100 years. As a biological covering with a broad scope of potential uses, human placental membranes represent a dressing that is particularly advantageous for burn therapy. Recent advances in tissue-preservation technology have allowed for the commercialization of placental amnion products.

PATIENT CONCERNS

To address several complications associated with burn injuries-contractures, scar formation, and pain-a viable cryopreserved placental membrane (vCPM) (Grafix-PRIME, Osiris Therapeutics, Inc., MD) retaining the anti-inflammatory, anti-fibrotic, and antimicrobial properties of fresh placental tissues was chosen for clinical use in the 2 cases reported, where both patients had restricted access to the regional burn center.

DIAGNOSES

Two cases of work-related extremity burns presented to a local rural hospital for immediate post-injury assessment. The 1 case was of a man who sustained a 55.4 cm full-thickness 3 degree thermal burn with exposed bone and tendon, to the left dorsal forefoot after having an industrial pressure washer caught on his work boot. The 2 case was of a female who sustained a 4.7 cm full-thickness 3 degree crush burn to the dorsum extensor surface of her dominant hand's index finger after applying 80-pounds per square inch of heated pressure from a hydraulic press.

INTERVENTIONS

Both burn patients elected to continue their care at the outpatient-based wound and hyperbaric center, receiving a combination of weekly ad libitum debridement, applications of vCPM, and occupational therapy.

OUTCOMES

Both burns reached timely wound closure, and patients regained full range of motion of the affected limb, allowing for early return to work. The average number of allograft applications was 7.5, allowing both patients to return to work in an average of 63.5 days without adverse events or post-treatment complications.

LESSONS

The incorporation of this product in the treatment of these complex burns prevented amputation in one patient, and skin autografting and potential index finger contracture-formation in the second patient. The incorporation of vCPM in burn management may offer a new approach to outpatient burn management and may mitigate several of the complications seen post burn injury, leading to favorable patient outcomes.

Placental Membranes for Management of Refractory Cutaneous Sinus Tracts of Surgical Origin: A Pilot Study

Despite advances in surgical technique, postoperative complications may lead to refractory cutaneous sinus tracts or tunnels. Negative pressure wound therapy is difficult to apply in longer tracts with a narrow diameter opening and conservative treatment failures ultimately necessitate surgical revisions. The aim of this pilot study was a clinical utility assessment of two different commercial placental membrane products for refractory cutaneous sinus tracts of surgical origin. Patients were treated with viable cryopreserved placental membrane (vCPM, n = 6) or devitalized dehydrated amnion/chorion membrane (dHACM, n = 6). The primary outcome measurement was the proportion of complete sinus tract depth resolution without exudate. Secondary endpoints included 4-week percent reduction in sinus tract probing depth and peri-tract wound surface area, days and number of grafts to resolution, number of wound-related infections, and 1-year recurrence rate for closed sinus tracts. All vCPM patients demonstrated complete sinus tract resolution compared to zero closures in the dHACM group (p = 0.00216). The vCPM group achieved greater percent reduction in probing depth (73.3 ± 21.9 versus −4.4 ± 91.3) and surrounding wound surface area (34.8 ± 86.8 versus −279.3 ± 454.9) at 4 weeks than dHACM. The use of viable intact cryopreserved placental membrane has demonstrated positive clinical outcomes for the treatment for refractory exudative sinus tracts and may be an alternative to repeat surgical intervention.