Pulmonary Cryobiopsy in the ICU: Clinical Utility in a Critically Ill Lung Transplant Recipient

Transbronchial forceps biopsy has historically been the standard method for lung allograft surveillance, but its diagnostic yield is limited by small samples and crush artefact. Transbronchial cryobiopsy (TBCB) provides larger, better-preserved specimens and may improve the diagnosis of acute cellular rejection, although comparative evidence remains heterogeneous. We describe a 22-year-old lung transplant recipient who developed severe acute respiratory distress syndrome as a manifestation of primary graft dysfunction, followed by clinical deterioration requiring mechanical ventilation, prone positioning, neuromuscular blockade and vasopressor support. Bedside TBCB, performed in the intensive care unit under mechanical ventilation using a 1.9-mm cryoprobe with prophylactic Fogarty balloon occlusion, established a diagnosis of high-grade (A4) acute cellular rejection, prompting escalation of immunomodulatory therapy with subsequent clinical improvement. This case suggests that TBCB may be feasible and clinically useful in selected, critically ill, mechanically ventilated lung transplant recipients, although its role relative to forceps biopsy cannot be established from a single observation.