The role of intraoperative transesophageal echocardiography in the management of renal cell carcinoma with atrial thrombus – case report

Renal cell carcinoma is a frequent disease, accounting for 3% of all cancers, with annually increasing incidence rates, with about 99,200 new cases recorded in the European Union in 2018^(1,2). According to the National Cancer Report from 2019, in Poland kidney cancer accounts for 3.8% of all malignancies in men and 2.3% in women, with a total of 5,214 new cases and 2,451 deaths in 2019.

There are three main types of renal cell carcinoma (RCC): clear cell (ccRCC), papillary (type I and II), and chromophobe RCC, with ccRCC being the most common type. A unique feature of RCC is the ability to infiltrate the venous system including the inferior vena cava (IVC) and the right atrium (RA) of the heart. On ultrasound imaging, tumor thrombus presents as an echogenic mass in the venous system. Vascular invasion above the diaphragm, including the RA, is described as stage IV in the Mayo classification⁽³⁾.

IVC invasion occurs in 4% to 10% of cases, whereas about 1% to 3% of patients present with thrombus reaching the RA⁽⁴⁾ . In cases of small, solid atrial tumor thrombus, treatment involves surgery through a transabdominal approach. In patients with fragile, large or adherent atrial thrombus, a transabdominal approach with sternotomy and cardiopulmonary bypass (CBP) is the preferred option. Extracorporeal circulation (ECC) with deep hypothermic circulatory arrest (DHCA) can be used in more challenging cases. Transesophageal echocardiography (TEE) is usually utilized to evaluate morphology and ensure intraoperative control of tumor thrombus.

We present the cases of two patients operated on RCC with tumor thrombus, who were intraoperatively monitored with the use of TEE. Transesophageal echocardiography was performed using GE Vivid S6 unit with a multiplane transesophageal probe with passing transducer into the esophagus through the oral cavity, using mid-esophageal imaging plane for the right atrium assessment. Endotracheal intubation was also performed through the mouth.

The first case involves a 67-year-old man diagnosed with stage IV kidney tumor, who underwent radical nephrectomy through the transabdominal approach only. The second case involved a 67-year old woman, also with stage IV kidney tumor, who underwent surgery through the transabdominal approach, also with intraoperative TEE that revealed detachment of the fragile tumor thrombus of the RA, which required immediate sternotomy and surgery performed with cardiac surgeon’s assistance.

In preoperative imaging, CT is the most common imaging modality used in the preoperative setting, whereas three-dimensional breath-hold T1-weighted MRI performed after intravenous gadolinium contrast administration is the most sensitive method⁽⁶⁾. Nevertheless, TEE can accurately define the cranial extent of tumor thrombus, and its diagnostic utility increases with the level of tumor thrombus extension⁽⁷⁾. At the stage of surgical planning, it helps to assess the nature of tumor thrombus, which includes size, consistency, fragility, adherence, and mobility⁽⁸⁾. Two main types of tumor thrombi are distinguished: solid, small atrial thrombus (case 1) and fragile or adherent thrombus that fills a large capacity of the RA (case 2). Based on TEE imaging, one can choose or modify the surgical approach depending on the situation: transabdominal approach with the milking maneuver of the tumor thrombus (case 1) or transabdominal approach with CBP and DHCA (case 2). It provides continuous monitoring of cardiac function, and helps with central line placement⁽⁶⁾. In the transabdominal approach, it guides the surgeon and prevents applying the vascular clamp to a portion of the IVC with the thrombus, which can result in embolization. Furthermore, it helps to rule out or confirm the presence of residual tumor thrombus in the IVC or in the RA, thus providing evidence of complete resection⁽⁸⁾.

TEE in the surgical treatment of RCC with stage IV tumor thrombus is an invaluable tool for the selection and modification of the surgical technique, as well as for performing and monitoring the surgical procedure. It helps to rule out residual tumor thrombus after surgery, and enables early detection of adverse events such as heart failure, or tumor thrombus embolism.