Post-lung transplantation airway complications contribute significantly to the morbidity and mortality of patients, with ischemia of the donor bronchi being the primary cause of such complications.(1) Bronchi obtain their blood supply from both the bronchial and pulmonary circulations; therefore, they are supplied by well-oxygenated blood from the aorta and/or intercostal arteries, whereas the pulmonary artery circulation contains deoxygenated blood. In lung transplantation, donor bronchial vessels are not connected to the recipient bronchial vessels, leaving the donor bronchi dependent on the low oxygenated pulmonary arterial supply. Vascularization of donor bronchi by the recipient bronchial circulation occurs 2–6 weeks post-transplant. Therefore, low perfusion of the pulmonary circulation in the first 6 weeks may result in airway complications. The main risk factors contributing to airway complications are poor lung preservation, prolonged ischemia times, long donor bronchus, certain surgical techniques, primary graft dysfunction, acute rejection, infection, hypotension, donor-recipient height mismatch, mTOR inhibitors, and prolonged mechanical ventilation/high PEEP.(1)
In the management of a partial bronchial dehiscence, deployment of airway stents, both covered and uncovered, has been used through flexible or rigid bronchoscopy. However, their use remains controversial due to the associated risks of infection, migration and bronchial injury. The use of fibrin glue through bronchoscopy has been described in cases of partial dehiscence. Surgical repair of the anastomosis is reserved for severe cases or failure to improve cases. In addition, management includes treating associated complications such as pneumothorax and pleural infection.
In the case presented here, the development of a partial anastomotic dehiscence and subsequent bronchopleural fistula 29 days (intermediate-onset) post-bilateral lung transplant could have been due to predisposition to any of the risk factors, including prolonged use of mechanical ventilation, prolonged hospital stay, donor-derived pneumonia with multidrug-resistant Pseudomonas aeruginosa, carbapenemase-producing Klebsiella pneumonia, and secondary bacteremia. A recent study showed that carbapenemase-producing Klebsiella pneumonia significantly increased the risk of developing bronchial anastomotic dehiscence in post-lung transplant patients.(3)
Platelet-rich plasma (PRP) is an autologous serum preparation that contains a high level of platelets.(5) PRP is easily obtainable and has been reported as an effective tool to promote wound healing. This wound healing property is explained by the fact that PRP releases abundant growth factors after application to tissues(6) and enhances healing by increasing the production of collagen and fibroblasts.(7) PRP can be easily prepared, and the storage cost is minimal; however, the potential for clinical use is limited to within 5–8 days of preparation. The use of PRP is steadily increasing and has been employed to treat various pathologies, including but not limited to, perianal fistulas in Crohn’s disease, recurrent vesicovaginal fistulas, oro-antral fistulas, and musculoskeletal pathologies.(8) One recent study reported 3 successful cases of autologous PRP injections to resolve one tracheobronchial fistula and two BPFs varying in size (4–8 mm), all post-lobectomies following different pathologies other than post-lung transplant.(9) Another study conducted on PRP usage as adjuvant therapy for the resolution of vesicovaginal fistulas reported resolution of the fistula with no complications or adverse effects.(10) Additionally, PRP treatment has been studied in porcine models with tracheal resection, where healing of end-to-end anastomosis was accelerated by promoting the release of platelet-derived growth factors (PDGF) and stimulating trans-anastomotic vessel formation.(11)
To the authors’ knowledge, there have been no previous case reports describing the use of PRP in the management of anastomosis fistula post-lung transplant. The innovative application of platelet-rich plasma in the treatment of anastomotic fistulas, particularly in patients with challenging presentations, seems to be an intervention with favorable surgical outcomes. Moreover, the technique discussed in this report is effective, relatively safe, reproducible, and requires minimal resources at least for small bronchial anastomotic dehiscence fistulas. However, further studies are required to confirm the effectiveness of PRP in the healing of bronchial anastomotic fistulas of larger sizes. Additional studies comparing traditional management methods with PRP treatment for bronchial anastomotic dehiscence fistula are also warranted. In addition, the optimal number, quantity, method, and timing of PRP applications or injections in the context of favorable surgical outcomes must also be determined.