Imaging the thoracic lymphatics: Experimental studies of swine

AbstractThe lungs and hearts of 15 swine were surgically harvested intact and studied in the fresh state. The lymphatics of the lung and mediastinum were cannulated and contrast medium was introduced by retrograde injection to identify the visceral pleural lymphatics and deep lymphatics of the lung. Radiographic x‐ray, CT, MR, and color photographic images were obtained. Collateralization, extravasation (bronchorrhea), perivascular stasis, and circumvention were demonstrated. Lymphatic communication with the contralateral lung, thoracic duct, heart, and the diaphragm was demonstrated. The findings correlate with the lymphangiographic display of lymphedema of the extremities, obstruction to lymph flow secondary to congenital abnormalities, trauma, tumor, and infections. Our results support the view that stents and/or large bore needles may be introduced into the superficial lymphatics of the lung. The lymphatics of the lung may be anastomosed post lung transplantation and thus possibly reduce passive congestion that occurs in the early postoperative period. The authors postulate that tumor cells and infectious agents may be spread from one lung to the other by the anatomical pathways demonstrated.