Endoscopic submucosal dissection for colorectal tumors.

BACKGROUND: Endoscopic submucosal dissection (ESD) is a state-of-the-art method that enables resection of larger tumors than those resectable by conventional endoscopic mucosal resection (EMR). However, the individual role of each method in the treatment of colorectal tumors remains undetermined. OBJECTIVE AND METHODS: To consider the respective indications of ESD and EMR for colorectal tumors, we analyzed the results of the two treatments retrospectively. RESULTS: Tumors treated by ESD (44 tumors) were significantly larger, more often located in the rectum and more often coexistent with cancer than those treated by EMR (512 tumors). EMR was used in the majority of adenomas, and showed high rates of both one-piece resection (OPR) and complete resection (CR) for adenomas less than 20 mm. However, for adenomas and cancers greater or equal to 20 mm, the CR rate for EMR was significantly lower than that for ESD because of the incidence of OPR with a positive lateral margin (16% vs 0% with ESD vs EMR). Histopathology (cancer), size (> or =20 mm) and macroscopic type (laterally spreading tumors) were shown to be significant risk factors for that incidence. For tumors with these factors, ESD showed a higher CR rate than did EMR. However, ESD required longer operating times and tended to have a higher rate of perforation compared with EMR. ESD was aborted halfway in seven cases due to technical difficulties and perforation. CONCLUSION: ESD and EMR have different characteristics as treatment for colorectal tumors. Careful evaluation of the lesion and of the balance between benefits and risks are mandatory before selecting either of these treatments for colorectal tumors.

Endoscopic submucosal dissection for rectal tumors.

BACKGROUND AND STUDY AIM: Endoscopic submucosal dissection (ESD) has recently been developed for one-piece resection of gastric tumors. In order to improve patients' quality of life, it may be desirable to use the same technique for rectal tumors. METHODS: 35 consecutive patients with rectal tumors were enrolled. ESD was carried out using the same technique as for the stomach. The efficacy, technical feasibility, operation time, complications, and follow-up results were assessed. RESULTS: The mean size of the epithelial tumors was 26.2 +/- 14.0 mm, and the rates of one-piece resection and one-piece resection with tumor-free margins were 73.3% (22 of 30) and 70.0% (21 of 30), respectively. The median operation time was 70 min (range 8-360 min). All five carcinoid tumors were completely resected. No patient needed blood transfusion or had the complication of problematic bleeding. Perforation during ESD occurred in one patient (2.9%), who was managed with conservative medical treatment after endoscopic closure of the perforation. Excluding seven patients, who either underwent additional surgery or whose follow-up period was less than 1 year, all 23 patients with epithelial tumors were free of recurrence during a mean follow-up period of 25.7 months (range 12-53 months). CONCLUSIONS: ESD was thus found to be feasible for the treatment of rectal tumors, with promising results although the follow-up periods were short. ESD may therefore be indicated for rectal tumors which are not resectable en bloc by conventional procedures, in order to improve the patients' quality of life.

Endoscopic submucosal dissection for early gastric cancers and large flat adenomas.

BACKGROUND AND STUDY AIM: Endoscopic submucosal dissection (ESD) is a new diagnostic and treatment technique for early gastric cancer (EGC). The present study aims to identify the technical feasibility, operation time, and complications associated with ESD. METHODS: We reviewed the patients who underwent ESD for EGCs at Maebashi Red Cross Hospital. RESULTS: There were 160 patients with 171 EGCs treated by ESD. The mean age was 71.4 +/- 8.9 years (median 72). The rate for one-piece resection with tumor-free margins was 94.2 % (161/171), and was 93.2 % (82/88) for large lesions (> 20 mm) and 92.1 % (35/38) for ulcerative lesions. The median operation time was 80 min (range 10-600 min). Evidence of immediate bleeding was found in 2.9 % (5/171), delayed bleeding was seen in 7.6 % (13/171), and perforation was observed in 3.5 % (6/171) of the lesions. All patients with complications, including perforation, were successfully treated endoscopically. There were no local or distant metastases in the lesions which met our indication criteria for ESD. CONCLUSION: The present study shows the technical feasibility of ESD, which provides the capability of one-piece resection even in large and ulcerative lesions.

A novel saturation transfer contrast method for 3D time-of-flight magnetic resonance angiography: a slice-selective off-resonance sinc pulse (SORS) technique.

Saturation transfer contrast (STC) techniques have been employed to decrease the signal intensity of observed water by saturating a broad proton component. The STC pulse, generally spatially nonselective, reduces the signal of brain background tissues as well as inflowing blood in 3D time-of-flight (TOF) angiography. We present a novel technique, a slice-selective off-resonance sinc pulse (SORS), which is employed to enhance inflowing blood and to suppress the signal of stationary background tissues. The STC effects of the SORS and other spatially nonselective methods influencing inflowing blood is discussed in detail. Angiograms using the SORS method are also presented to demonstrate improved vessel conspicuity. In addition, the SORS method is applicable to imagers with a whole-body RF transmitter system.