A Single Center Case Series of Lung Transplantation for a Rare Indication, Pulmonary Alveolar Microlithiasis

Abstract

Pulmonary alveolar microlithiasis (PAM) is a rare slowly progressive disease, usually ends into respiratory failure. PAM is characterized by intra-alveolar accumulation of calcium and phosphate corpuscles. Lung transplantation (LTx) is the treatment for this disease when it causes respiratory failure. This study describes one of the largest case series worldwide, highlighting the role of LTx in patients suffering from PAM, ensuring its safety, feasibility and effectiveness. Timing of referral and considering the patient for LTx is the key to success. Although there are no clear guidelines, presence of respiratory failure and pulmonary hypertension are the main criteria for considering LTx to prevent RV failure. A retrospective chart review including all patients who underwent LTx at our center between 2010 and 2018 was performed. Five patients with the primary diagnosis of PAM were identified. Preoperative and postoperative outcomes are shown in Figure.Five patients with PAM and associated pulmonary hypertension had bilateral LTx with the aid of extra-corporeal membrane oxygenation (ECMO) support intraoperatively. Central ECMO was used for cardiopulmonary support in all our cases to stabilize the hemodynamics and prevent hyper perfusion of the first implanted lung during implantation of the second. ECMO is preferred over bypass as it is associated with less bleeding, less mechanical ventilation, and shorter ICU stay. Before discharge, all our patients were off oxygen, maintaining oxygen saturation above 90% on room air. No recurrence of the primary disease was observed. All our cases are still alive, following up with us till now (average 25 months). Only one case developed lung allograft dysfunction and is currently on our active waiting list for redo LTx. Bilateral lung transplantation is considered till now the only treatment method for PAM with respiratory failure. It is a well-tolerable, safe, and effective method if done under experienced hands.