Turning four-wave mixing on and off in elliptically birefringent fibers via narrow frequency detuning.

Controlling four-wave mixing (FWM) is vital for several applications, including fiber optical communication, optical signal processing, optical amplification, and frequency generation. This paper presents a novel, to our knowledge, approach to control unidirectional FWM in elliptically birefringent fibers. By leveraging the frequency-dependent polarization eigenmodes of these fibers and detuning the optical frequency of one of the pump fields by a few megahertz, we can turn the FWM interaction on and off, thus controlling the generation of signal and idler fields.

Outcomes of submucosal (T1b) esophageal adenocarcinomas removed by endoscopic mucosal resection.

Aim: To investigate the outcomes and recurrences of pT1b esophageal adenocarcinoma (EAC) following endoscopic mucosal resection (EMR) and associated treatments.

Methods: Patients undergoing EMR with pathologically confirmed T1b EAC at two academic referral centers were retrospectively identified. Patients were divided into 4 groups based on treatment following EMR: Endoscopic therapy alone (group A), endoscopic therapy with either chemotherapy, radiation or both (group B), surgical resection (group C) or no further treatment/lost to follow-up (< 12 mo) (group D).

Cold snare piecemeal resection of colonic and duodenal polyps ≥1 cm.

Background: Endoscopic removal of duodenal and colorectal adenomas is currently considered to be the standard of care for prevention of adenocarcinoma. The use of cautery carries a risk of delayed bleeding, post-polypectomy syndrome, and perforation. We examined the safety and feasibility of removing colonic and duodenal polyps ≥ 1 cm using a piecemeal cold snare polypectomy technique.

The risk of post-ERCP pancreatitis and the protective effect of rectal indomethacin in cases of attempted but unsuccessful prophylactic pancreatic stent placement.

Background: It is believed, based on limited observational data, that an unsuccessful attempt to place a prophylactic pancreatic stent substantially increases the risk of post-ERCP pancreatitis (PEP).

Objective: To better understand the risk of PEP in patients with failed pancreatic stent placement (FPS) and the impact of rectal indomethacin on this risk.

Design: Secondary analysis of randomized, controlled trial data.

International multicenter experience with an over-the-scope clipping device for endoscopic management of GI defects (with video).

Background: The over-the-scope clip (OTSC) provides more durable and full-thickness closure as compared with standard clips. Only case reports and small case series have reported on outcomes of OTSC closure of GI defects.

Objective: To describe a large, multicenter experience with OTSCs for the management of GI defects.