Chronological Outcomes and Learning Curve of Endoscopic Submucosal Dissection for Colorectal Tumors / 대한소화기학회지

BACKGROUND/AIMS: Endoscopic submucosal dissection (ESD) is an effective procedure for en-bloc curative resection of the colorectal tumor. As it requires high technical skills and experience in therapeutic endoscopy, it is important to understand learning curve of ESD technique. The aim of this study was to retrospectively describe the clinical results of ESD and to evaluate learning curve for the ESD of colorectal tumors. METHODS: A total of 90 patients with 90 colorectal neoplasms, who had undergone ESD at a tertiary referral hospital from July 2009 to December 2012, were enrolled. The ESD was performed by a single endoscopist. All ESD cases were divided into three periods: first, cases 1-30; second, cases 31-60; and third, cases 61-90. RESULTS: The en-bloc resection rates in third period (100%) was significantly higher than that of the first (93.3%) and second period (80%) (p=0.025). The perforation rate in third period (0%) also significantly decreased compared with that of the first (13.3%) and second period (20%) (p=0.032). To calibrate the difference of tumor size among periods, proficiency was calculated, as the procedure time per specimen area (min/cm2). The proficiency in third period (4.3) was significantly shorter than that of the first (16.8) and second period (10.2) (p=0.004). CONCLUSIONS: The learning curve of colorectal ESD in our study shows that at least 60 cases of ESD have to be conducted to acquire sufficient skill of degree without perforation.

Evaluation of friction of ceramic brackets in various bracket-wire combinations / 대한치과교정학회지

The purpose of this study was to measure and compare the level of frictional resistance generated from three currently used ceramic brackets; 1, Crystaline V(R), Tomy International Inc., Tokyo, Japan; 2, Clarity(R), 3M Unitek, Monrovia, CA, USA; 3, Inspire(R), Ormco, Orange, CA, USA; with composite resin brackets, Spirit(R), Ormco, Orange, CA, USA; and conventional stainless steel brackets, Kosaka(R), Tomy International Inc., Tokyo, Japan used as controls. In this experiment, the resistance to sliding was studied as a function of four angulations (0 degrees, 5 degrees, 10 degrees, and 15 degrees) using 2 different orthodontic wire alloys: stainless steel (stainless steel, SDS Ormco, Orange, CA, USA), and beta-titanium (TMA, SDS Ormco, Orange, CA, USA). After mounting the 22 mil brackets to the fixture and .019 x .025 wires ligated with elastic ligatures, the arch wires were slid through the brackets at 5 mm/min in the dry state at 34 degrees C. Silica-insert ceramic brackets generated a significantly lower frictional force than did other ceramic brackets, similar to that of stainless steel brackets. Beta-titanium archwires had higher frictional resistance than did stainless steel, and all the brackets showed higher static and kinetic frictional force as the angulations increased. When the angulation exceeded 5 degrees, the active configuration emerged and frictional force quickly increased by 2.5 to 4.5-fold. The order of frictional force of the different wire-bracket couples transposed as the angle increased. The silica-insert ceramic bracket is a valuable alternative to conventional stainless steel brackets for patients with esthetic demands.

A Case of Triple Cancers of the Esophagus, Stomach and Duodenum / 대한소화기내시경학회지

Multiple primary cancer is defined as the multiple occurrence of malignant neoplasm in the same individual. The incidence of multiple primary cancer is 0.26~1.43% in Korea, but this malady is increasing due to development of diagnostic modalities, the treatment of cancer and the recording of accurate cancer statistics. The most common site of multiple primary cancer in Korea is the stomach, colon, breast, cervix, liver and lung. We report here on a case of triple cancer that was located at the middle esophagus, stomach and duodenum in 75 year-old man.