Thoracoscopic Localization of Pulmonary Nodules Using Direct Intracavitary Thoracoscopic Ultrasound

Pulmonary nodules are one of the most common thoracic radiographic abnormalities. They are usually found accidentally as discrete well emarginated pulmonary lesions found within the lung parenchyma during a routine chest x-ray. Pulmonary nodules are usually asymptomatic. Most solitary lung nodules are benign; however these nodules can represent early stage lung cancer. The identification of malignant pulmonary nodules is important because they represent a potential form of curable lung malignancy. Every lung nodule should therefore be investigated for the possibility of malignancy.

Ultrasound has been beneficial in almost all medical and surgical specialities. The idea of using ultrasound during VATS has emerged from its use in laparoscopic procedures. Few studies have investigated the use intracavitary ultrasound for localizing pulmonary nodules. The sensitivity of ultrasound detecting pulmonary nodules is high (92%). In some studies, ultrasound could detect all pulmonary nodules detected by high resolution CT. It has also been shown to be able to locate nodules not visualized on spiral CT.

The use of intracavitary ultrasound has been suggested by many authors as a safe and effective method for localizing hard to find nodules. It is a real time technique with no associated complications, low cost, and has the potential to save operative time. Most importantly, it may be able to prevent conversion of VATS to open operations in cases where nodules are not visualizable or locatable using VATS techniques.

The use of intracavitary US as a localization method by surgeons intra-operatively could lead to better identification of nodules. Also, this technique could avoid performing multiple procedures on patients (CT guided targeting followed by surgery) and therefore is more cost-efficient. If proven accurate, surgeon-performed intracavitary ultrasound could be used routinely during VATS procedures, increasing the chances of finding and localizing pulmonary nodules using minimally invasive techniques.