Chronic lower-extremity ulcers remain difficult to treat, particularly in patients with metabolic and vascular comorbidities.This multicentre case series describes four patients with chronic lowerextremity ulcers that persisted for at least six months despite conventional management.The study evaluated topical application of edelweiss callus culture-derived exosomes (Exo-HL; Primoris International Co., Ltd., Seoul, Korea) used as an adjunct to standard wound care.All ulcers had persisted for at least six months despite conventional management.After wound cleansing and debridement as required, exosomes (0.5-1.0 mL; approximately 0.1 mL/cm) were applied directly to the wound bed at monthly visits, followed by non-adherent sterile dressings.Clinical progress was documented by serial photography and wound measurements.Arterial and venous Doppler ultrasonography was performed at baseline and at three-month intervals to assess changes in perfusion and venous reflux.Across the series, all patients demonstrated progressive granulation and re-epithelialisation without treatment-related adverse events.Early size reduction was observed within 15 days in one case, complete granulation and re-epithelialisation occurred within 60 days in another, and near-complete closure was achieved over five to seven months in a third.In a severe post-infective ulcer for which amputation had been recommended, complete closure was achieved over approximately six months.Doppler parameters improved in all cases, including reductions in resistive index and venous reflux time and/or increases in peak systolic velocity.This small, uncontrolled series suggests that topical exosome therapy may be a feasible adjunct in refractory chronic ulcers, with concurrent improvements in clinical healing and Doppler-assessed vascular dynamics.Larger controlled studies are required to define efficacy and optimal treatment schedules.
Machado et al. (Wed,) studied this question.