Pulmonary vein stenosis is a debilitating condition that carries a high mortality despite aggressive surgical and transcatheter intervention strategies. Systemic sirolimus therapy (SST) given alongside conventional interventional management of pulmonary vein stenosis has shown improvement in outcomes and a slower progression of the disease. No data is currently available of the tolerance and feasibility of systemic sirolimus therapy in this fragile patient population.

In this single-centre study we report our experience from December 2022 to December 2025 looking at primary outcomes of survival, duration of sirolimus therapy, and frequency and duration of sirolimus therapy pauses. Secondary outcome measures included the number of surgical and interventional procedures undertaken, any adverse events related to systemic sirolimus therapy, the most recently available pulmonary artery pressure measurements, and the latest clinical status of the patients.

Twelve patients received systemic sirolimus therapy, with one patient undergoing two separate episodes of treatment. All patients were alive at the time of follow-up, and 11 out of 12 patients had no cardiac symptoms at their latest clinical review. 1 patient was removed from analysis as their SST is managed by their local hospital. The total number of days of treatment was 4851 days with a median for each episode of therapy of 373 days (range 74–1102). There were 43 pauses in therapy, with a median number of 3 pauses per episode of therapy (range 0–11). The total number of days paused was 401 (8.3%), and the median number of days paused per episode was 20 days (range 0–158).

Sirolimus therapy is safe and effective in this cohort with multiple pulmonary vein stenoses. The combination of systemic sirolimus and aggressive transcatheter management seems to optimize the patient's outcome and clinical status.