Endoscopic ultrasound as a surrogate for transoesophageal echocardiography for intra‐operative monitoring of a catheter‐related right atrial thrombus during gastrectomy

A 46‐year‐old man diagnosed with carcinoma of the stomach, received neoadjuvant chemotherapy with six cycles of 5‐fluorouracil, leucovorin, oxaliplatin, docetaxel through a 9.6 French chemotherapy port inserted in the right internal jugular vein. Trans‐thoracic echocardiogram (TTE) performed 2 weeks after chemotherapy revealed a thrombus in the right atrium (2.2 × 1.5 cm) and normal contractility of the cardiac chambers. Computed tomography pulmonary angiogram confirmed the absence of a pulmonary embolus. He was planned for gastrectomy. The chemotherapy port was removed as it was non‐functional.

The main anaesthetic challenge was that we had no means of intra‐operative monitoring of the thrombus. A TTE was precluded from intra‐operative use. A transoesophageal echocardiogram (TOE) was not available at our centre. Endoscopic ultrasound (EUS) is used for diagnostic and therapeutic procedures of the gastrointestinal tract. We contemplated whether this could be used instead of TOE. This would be an off‐label use of the EUS, and hence, we requested a gastroenterologist who is experienced in this technique to assess the thrombus.

On the day of surgery, the patient received general anaesthesia with fentanyl, etomidate and vecuronium, after which tracheal intubation was performed. Anaesthesia maintenance was with sevoflurane in air and oxygen titrated to a minimum alveolar concentration of 0.9–1.0. Intra‐arterial blood pressure was monitored and a femoral venous line inserted. Epidural analgesia was avoided as the patient would receive full anticoagulation postoperatively. Analgesia was multimodal with intrathecal morphine, intravenous morphine boluses and transversus abdominis plane blocks.

After induction of anaesthesia, prior to commencing surgery, the gastroenterologist inserted the EUS probe (Fujifilm EG‐580UT Linear Endoscopic Ultrasound Scope; FUJIFILM Corporation, Tokyo, Japan) to a depth of 40 cm into the oesophagus. The probe was then carefully withdrawn and with some clockwise and anticlockwise manoeuvres the intrahepatic part of the inferior vena cava was traced which led to the right atrium. The thrombus was visualised, and its dimensions measured. It was described as pedunculate with a thin stalk, mobile with cardiac pulsation and not occluding the tricuspid valve. A view akin to the bicaval view of TOE was obtained (Video S1). The probe was withdrawn from the oesophagus and the equipment was retained inside the operating room for use in the event of any haemodynamic compromise.

The intra‐operative haemodynamic values were stable. At the end of surgery, a repeat EUS showed the thrombus to be static in dimension and morphology. The patient's trachea was extubated after which he was transferred to the intensive care unit. A therapeutic dose of enoxaparin was started within 24 h and apixaban commenced before discharge from hospital.

Transoesophageal echocardiography is the gold standard for diagnosing left atrial thrombi with a sensitivity of 100% and specificity of 99% [1]. With regard to right atrial thrombi, TOE elucidates their location, size, mobility and composition [2]. It also has the advantage of intra‐operative dynamic monitoring of cardiac chambers [3, 4] and helps to detect pulmonary emboli [5]. However, its availability is mostly restricted to cardiac centres. We have demonstrated that endoscopic ultrasound could serve as a good surrogate for TOE. It has a better field of view (140 degrees versus 90 degrees of TOE) and offers higher resolution images (due to ultrasound frequency up to 12 MHz versus 7 MHz of TOE). The limitations are the bulkiness of the probe, logistics and the expertise required to perform and interpret the findings. At centres with no access to TOE, an EUS could prove invaluable if available.

Supporting information

Video S1. Endoscopic ultrasound dynamic image of a catheter‐related right atrial thrombus.