OR-LUM-05: Impact of endoscopic ultrasound-guided fine needle aspiration from peritoneal lesions for avoiding diagnostic laparoscopy (ipad study): The first prospective study (preliminary results)

BACKGROUND: In patients with undiagnosed peritoneal lesions, diagnostic laparoscopy is often required for tissue diagnosis. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is another possible approach but has never been prospectively evaluated. OBJECTIVES: To study the efficacy of EUS-FNA for avoiding diagnostic laparoscopy in patients with peritoneal lesions. METHODS: From December 2015 to October 2016, 18 consecutive patients with peritoneal lesions were enrolled. Diagnostic laparoscopy was planned if pathological result of EUS-FNA was negative. RESULTS: Computed tomographic findings were soft tissue nodules/mass deposit in the peritoneum (n = 13; 72.2%), ascites (n = 12; 66.7%), omental cake appearance (n = 6; 33.3%), and stranding of mesentery (n = 3; 16.7%). Two benign cases were pancreatic ascites confirmed by laparoscopy and peritoneal tuberculosis confirmed by successful treatment. EUS-FNA showed positive results of malignancy in 14/18 patients (77.8%) and 28/54 passes (51.8%). Of 28 passes with positive results, 22/28 (78.6%) and 6/28 (21.4%) were obtained from hypoechoic and hyperechoic lesions, respectively. No adverse events were observed. Of four patients with negative results of EUS-FNA, two patients underwent diagnostic laparoscopy showing multiple omental and peritoneal nodules from metastatic stomach cancer (n = 1) and pancreatic ascites (n = 1) and another two patients refused laparoscopy; one had advanced staged pancreatic cancer with poor performance status and another was clinically diagnosed as peritoneal tuberculosis with successful treatment. The sensitivity and specificity of EUS-FNA were 87.5% and 100%, respectively. Diagnostic laparoscopy can be avoided in 14/18 (77.8%) patients. CONCLUSIONS: In this prospective study, EUS-FNA has a high sensitivity rate for diagnosing causes of peritoneal lesions and can avoid diagnostic laparoscopy in majority of patients.