Iatrogenic Pneumothorax and Other Adjunctive Techniques for Ablation Therapies of Hepatic Dome Tumors

Purpose: To provide an overview of challenges in percutaneous access of the hepatic dome lesions and discuss current maneuvers and techniques facilitating technical success and safety during the microwave ablation of the tumors in the subdiaphragmatic portion of the liver

Materials and Methods: We describe a patient with colon cancer metastatic to the liver. His imaging studies demonstrate a single dome lesion that was appropriate for treatment with microwave ablation. To prevent heating injury to the adjacent lung parenchyma, we induced an iatrogenic pneumothorax before percutaneous access. This case guided our literature search and provided ground for a discussion on accessing challenging hepatic dome lesions as well as adjunct procedures that may facilitate ablation therapy in this region. An additional case of subdiaphragmatic hydrodissection will be described to support various techniques of risk reduction during the procedure.

Results: A 58-year-old male patient with colorectal cancer metastatic to the liver after neoadjuvant chemotherapy (FOLFOX - folinic acid, fluorouracil and oxaliplatin), open left hepatectomy, and colectomy presented with a new solitary right hepatic lobe dome lesion concerning for new metastatic focus on positron emission tomography/ computed tomography (PET/CT). CT-guided core liver biopsy showed metastatic moderately differentiated adenocarcinoma of colorectal origin. We discuss surgical resection, thermal ablation, chemoembolization, and yttrium-90 radioembolization as possible treatment modalities as well as the most appropriate therapeutic plan for the management of this patient. We describe subcostal, intercostal, and epipericardial fat pad approaches that can be considered to access a hepatic dome lesion, as well as techniques to overcome procedural challenges in this location. Our case demonstrates an induction of an iatrogenic pneumothorax before ablation to prevent passage of microwave antenna through the lung parenchyma. Literature review provides alternative techniques, such as artificial pleural effusion, carbon dioxide insufflation, and angiographic balloon interposition.

Conclusions: Oligometastatic liver lesions can be treated surgically or with thermal ablation. Thermal ablation has a lower complication rate, better health-related quality of life, and lower cost but a higher local recurrence rate than surgery. Chemoembolization and radioembolization are effective palliative treatment options for patients with liver-dominant colorectal metastatic disease who cannot undergo resection or ablation. Interventional procedures in the hepatic dome are challenging because of potential diaphragmatic, lung, or pleural injury. Pulmonary transgression can be safely avoided by creation of artificial pleural effusion or pneumothorax.