IPEG 2020 TOP ABSTRACT: Thoracoscopic Pulmonary Metastasectomy for Hepatoblastoma Using Indocyanine Green

Metastatic hepatolastoma management in the pediatric population presents numerous challenges. Resection of pulmonary lesions has previously been described, but presents several technical difficulties in both localization and surgical resection. This video illustrates the use of endocyanin green, or ICG dye in spy imaging to successfully identify pulmonary lesions intraoperatively while maintaining a thoracoscopic approach for resection. This case involves a 2-year-old female with metastatic hepatoblastoma to bilateral lungs who had completed 3 previous rounds of chemotherapy. A CT image of her tumor is demonstrated here. Following neoadjuvant therapy, she remained pretext 3 and unresectable. Our surgical goal was to resect her pulmonary disease to make her eligible for a liver transplant. Her pulmonary lesions were demonstrated on CT scan, and she was scheduled for a staged video-assisted thoracoscopic resection. Due to the known affinity of ICG dye for hepatocytes and building on our own experience using ICG intraabdominally, we surmised that ICG would provide a safe and effective method of intraoperative visual identification of the metastatic hepatoblastoma lesions. ICG was injected systemically at a dose of 0.5 mg per kilogram approximately 24 hours prior to scheduled surgery. The patient then underwent a resection of the left and right thoracic lesions in a two-day sequential operative course. In the operating room, we were able to identify the lesions with ICG uptake with three different imaging modes, including spy overlay, spy contrast, and spy envy. The thoracic cavity was explored for identification of metastatic lesions. Using this by overlay mode. The lung tissue was manipulated to reveal a green fluorescent lesion on a white light image. Another lesion was then identified, and the various modes were explored. The camera mode was adjusted to spy contrast to reveal a bright white lesion against a dark background. The last mode demonstrated is the spy envy mode in which fluorescent imaging was used with a gray scale background. As the targeted lesion was isolated, a stapler was used to remove the metastatic tissue with very limited resection of surrounding normal parenchyma. Once outside the thoracic cavity, each resected lesion was easily identified due to the uptake of ICG as demonstrated here in the different modes. Several unexpected pulmonary lesions were easily identified using this technology that were not appreciated on initial CT imaging. The postoperative chest X-ray after the left thoracoscopic surgery demonstrates a left chest tube in place with no pneumothorax present. Similarly, the postoperative chest X-ray from day 2 of surgery on the right side demonstrates bilateral chest tubes and no pneumothorax present. The child was discharged on the 3rd postoperative day. The resected specimens were processed by pathology and revealed the following images. Picture A is one of the gross specimens. Picture B displays a 0.2 centimeter mass surrounded by healthy parenchymal tissue. A magnified image illustrates sheets and cords of polygonal cells with round nuclei and mild pleomorphism consistent with the metastatic lesion. In the last image, amino histochemistry for hep par 1 was employed to illustrate the uptake by the metastatic hepatoblastoma tissue due to the affinity for hepatocytes. This video demonstrates successful identification and thoracoscopic resection of bilateral metastatic lesions in a 2-year-old female. After pathology processing, the resected tissue confirmed multiple metastatic hepatoblastoma lesions. On preoperative CT scan, 3 left-sided lesions and 2 right-sided lesions were expected. Due to the technology and utilization of ICG dye, 8 total lesions were identified and removed. The higher sensitivity and detection of metastatic pulmonary hepatblastoma by utilization of ICG dye and fluorescent imaging allows for parenchymal sparing and minimally invasive resection. While traditional methods such as wire localization may be necessary for lesions deeper than 1.5 centimeters, the use of ICG to identify superficial metastatic lesions is a developing technology with significant clinical application. This video exhibits the feasibility, safety, and improved accuracy of thoracoscopic hepatoblastoma metastasectomy resection augmented by the use of endocyanin grain. Thank you for your attention.