Brief Article
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World J Gastroenterol. Mar 14, 2014; 20(10): 2681-2687
Published online Mar 14, 2014. doi: 10.3748/wjg.v20.i10.2681
Forward-viewing radial-array echoendoscope for staging of colon cancer beyond the rectum
Pradermchai Kongkam, Sittikorn Linlawan, Satimai Aniwan, Narisorn Lakananurak, Suparat Khemnark, Chucheep Sahakitrungruang, Jirawat Pattanaarun, Supakij Khomvilai, Naruemon Wisedopas, Wiriyaporn Ridtitid, Manoop S Bhutani, Pinit Kullavanijaya, Rungsun Rerknimitr
Pradermchai Kongkam, Sittikorn Linlawan, Satimai Aniwan, Narisorn Lakananurak, Suparat Khemnark, Wiriyaporn Ridtitid, Pinit Kullavanijaya, Rungsun Rerknimitr, Gastrointestinal Endoscopy Excellent Center, Department of Medicine, King Chulalongkorn Memorial Hospital, Chulalongkorn University, Bangkok 10330, Thailand
Chucheep Sahakitrungruang, Jirawat Pattanaarun, Supakij Khomvilai, Department of Surgery, King Chulalongkorn Memorial Hospital, Chulalongkorn University, Bangkok 10330, Thailand
Naruemon Wisedopas, Department of Pathology, King Chulalongkorn Memorial Hospital, Chulalongkorn University, Bangkok 10330, Thailand
Manoop S Bhutani, Department of Gastroenterology, Hepatology and Nutrition-Unit UT MD Anderson Cancer Center, Houston, TX 77030, United States
Author contributions: Kongkam P, Linlawan S, Aniwan S, Lakananurak N, Khemnark S, Sahakitrungruang C, Pattanaarun J, Khomvilai S, Wisedopas N, Ridtitid W, Bhutani MS, Kullavanijaya P and Rerknimitr R designed research; Kongkam P, Linlawan S, Lakananurak N, Sahakitrungruang C, Pattanaarun J, Khomvilai S and Wisedopas N performed research; Kongkam P and Linlawan S analyzed data; Kongkam P, Kullavanijaya P and Rerknimitr R wrote the paper.
Correspondence to: Pradermchai Kongkam, MD, Gastrointestinal Endoscopy Excellent Center, Department of Medicine, King Chulalongkorn Memorial Hospital, Chulalongkorn University, 1873, Rama 4 Road, Patumwan, Bangkok 10330, Thailand. kongkam@hotmail.com
Telephone: +66-2-2564356 Fax: +66-2-6524219
Received: July 2, 2013
Revised: December 18, 2013
Accepted: January 8, 2014
Published online: March 14, 2014
Processing time: 253 Days and 1.3 Hours
Abstract

AIM: To evaluate feasibility of the novel forward-viewing radial-array echoendoscope for staging of colon cancer beyond rectum as the first series.

METHODS: A retrospective study with prospectively entered database. From March 2012 to February 2013, a total of 21 patients (11 men) (mean age 64.2 years) with colon cancer beyond the rectum were recruited. The novel forward-viewing radial-array echoendoscope was used for ultrasonographic staging of colon cancer beyond rectum. Ultrasonographic T and N staging were recorded when surgical pathology was used as a gold standard.

RESULTS: The mean time to reach the lesion and the mean time to complete the procedure were 3.5 and 7.1 min, respectively. The echoendoscope passed through the lesions in 13 patients (61.9%) and reached the cecum in 10 of 13 patients (76.9%). No adverse events were found. The lesions were located in the cecum (n = 2), ascending colon (n = 1), transverse colon (n = 2), descending colon (n = 2), and sigmoid colon (n = 14). The accuracy rate for T1 (n = 3), T2 (n = 4), T3 (n = 13) and T4 (n = 1) were 100%, 60.0%, 84.6% and 100%, respectively. The overall accuracy rates for the T and N staging of colon cancer were 81.0% and 52.4%, respectively. The accuracy rates among traversable lesions (n = 13) and obstructive lesions (n = 8) were 61.5% and 100%, respectively. Endoscopic ultrasound and computed tomography had overall accuracy rates of 81.0% and 68.4%, respectively.

CONCLUSION: The echoendoscope is a feasible staging tool for colon cancer beyond rectum. However, accuracy of the echoendoscope needs to be verified by larger systematic studies.

Keywords: Colon cancer; Neoplasm; Colon; Endoscopic ultrasound; Neoadjuvan therapy; Staging; Forward-viewing; Colonoscopy

Core tip: Endoscopic ultrasound staging of rectal cancer has higher accuracy rate than computed tomography (CT) scan. Unfortunately, with the current design of conventional oblique-viewing radial-array echoendoscope that cannot readily be introduced beyond rectum, staging of colon cancer beyond rectum nowadays depends on results of CT scan. With a design of the novel forward-viewing radial-array echoendoscope that can be easily passed through the entire colon, it was firstly used in this study for staging of colon cancer. The study showed feasibility of the scope and its superiority over CT scan in terms of accuracy rate of colon cancer staging.