Therapeutic endoscopy and endoscopic ultrasound for gastrointestinal malignancies

Stone extraction balloon-guided repeat self-expanding metal stent placement

Self-expanding metal stent (SEMS) placement offers safe and effective palliation in patients with upper gastrointestinal obstruction due to a malignancy. Well described complications of SEMS placement include tumor growth, obstruction, and stent migration. SEMS occlusions are treated by SEMS redeployment, argon plasma coagulation application, balloon dilation, and surgical bypass. At our center, we usually place the second SEMS into the first SEMS if there is complete occlusion by the tumor. We discovered an unusual complication during SEMS redeployment. The guidewire passed through the mesh of the first SEMS and caused the second SEMS to become entangled with the first SEMS. This led to the distortion and malfunction of the second SEMS, which worsened the gastric outlet obstruction. For lowering the risk of entanglement, we studied stone extraction balloon-guided repeat SEMS placement. This is the first report of a SEMS entangled by the mesh of the first SEMS and stone extraction balloon-guided repeat SEMS placement for lowering the risk of this complication.

Interstitial devices for minimally invasive thermal ablation by high-intensity ultrasound

Interstitial ultrasound applicators have been proposed for treating deep-seated tumours that cannot be reached with extra-corporeal high-intensity focused ultrasound. In addition, interstitial ultrasound offers several advantages compared with conventional ablation technology (radiofrequency, microwaves, cryotherapy) in terms of penetration, speed of coagulation, ability to direct and control the thermal lesion and compatibility with image monitoring. The ultrasound source is brought as close as possible to the target in order to minimize the effects of attenuation and phase aberration along the ultrasound pathway. The present paper is a review of the interstitial applicators that were described during the last decade in the literature. It is presented in three sections. The technical aspects common to all applicators are first described. For example, most-described applicators are sideview applicators whose active element is water-cooled and operates at rather high frequency (above 3 MHz) in order to promote heating. Then the different potential techniques for monitoring treatment administered by the interstitial route are presented and illustrated through a review of image-guided interstitial thermal ablation. Three major techniques of imaging are used for guiding interstitial treatment: MRI, ultrasound and fluoroscopy. The third section goes in to further detail on diverse described medical applications.

Operative colonoscopy in cancer patients

Gastrointestinal endoscopy has experienced tremendous developments in technology and equipment over the past decades. It is not only a diagnostic tool, but it also allows some interventional treatments in benign and malignant digestive diseases. Operative colonoscopy has been used to perform curative treatment of various kinds of polyps, flat and carpet-like adenomas and early colorectal carcinomas. Endoscopic palliative treatment strategies, such as the placement of self-expandable metal stents (SEMS), laser ablation, photodynamic therapy (PDT), argon plasma coagulation (APC), electrocoagulation, and injection therapy, have been proved to effectively alleviate advanced colorectal cancer (CRC) associated symptoms and maintain or improve the quality of the patient's remaining life.