Endoscopic full-thickness dissection (EFTD) in the rectum: a case series

Background Rectal endoscopic full- thickness dissection (EFTD) using a flexible colonoscope is an alternative to the well-established trans-anal endoscopic microsurgery (TEM) and the trans-anal minimally invasive surgery (TAMIS) techniques for resecting dysplastic or malignant rectal lesions. This study evaluated EFTD safety by analyzing outcomes of the first patients to undergo rectal EFTD at the University Hospital of North-Norway. Methods The first 10 patients to undergo rectal EFTD at the University Hospital of North-Norway April, 2016 and January, 2021, were included in the study. The procedural indications for EFTD were therapeutic resection of non-lifting adenoma, T1 adenocarcinoma (AC), recurrent neuroendocrine tumor (NET) and re-excision of a T1-2 AC. Results EFTD rectal specimen histopathology revealed three ACs, five adenomas with high-grade dysplasia (HGD), one NET and one benign lesion. Six procedures had negative lateral and vertical resection margins and in three cases lateral margins could not be evaluated due to piece-meal dissection or heat damaged tissue. Two patients experienced delayed post-procedural hemorrhage, one of whom also presented with a concurrent post-procedural infection. No serious complications occurred. Conclusion Preliminary results from this introductory trial indicate that EFTD in the rectum can be conducted with satisfactory perioperative results and low risk of serious complications.

Comparison between three techniques for videosinuscopy in cattle

ABSTRACT: Cattle have extensive paranasal sinuses that are susceptible to disease, most commonly sinusitis. The sinuscopy can be used to evaluate these structures, although there are no descriptions of this region for endoscopic anatomy, especially regarding the trocar position and the most appropriate type of endoscope. This study aimed to standardize the surgical approaches to sinuscopy in cattle by comparing the use of three endoscopes. Four accesses by trephination (one hole for each of the maxillary and frontal sinuses) were made in eight heads of slaughtered cattle. Each hole was inspected with three endoscopes: a 10mm flexible colonoscope with up to 180º of angulation, a 10mm 0° laparoscope and a 4mm 30º arthroscope. It was observed that all regions of the maxillary sinus were better visualized with the 4mm endoscope, and the structures of this sinus were less well visualized with the 10mm laparoscope. The frontal sinus was difficult to evaluate due to the tortuosity of its bony projections, and the cranial portion was not observed by the proposed accesses. The caudal regions of the frontal sinus such as the nuchal diverticulum and the back of the orbit had the greatest number of structures visualized by the 4mm endoscope, followed by the colonoscope. The comparative analysis showed that the 4mm endoscope was most efficient and could be adapted to sinuscopy in cattle.

Description of cloacoscopy in the loggerhead sea turtle (Caretta caretta)

The aim of the study was to describe cloacoscopy in the loggerhead turtle (Caretta caretta) and to evaluate its efficacy in clinical practice. Cloacoscopy was performed on 31 turtles, 23 females and 8 males. Thirty minutes before anaesthesia, meloxicam (0.4 mg/kg) was administered intramuscularly. Turtles were anaesthetised with a combination of 0.04 mg/kg dexmedetomidine and 4 mg/kg ketamine administered intramuscularly. Cloacoscopy was performed with a diagnostic telescope (10 mm diameter, 30 cm long, 0°, with an operating sheath) or with a flexible colonoscope (13 mm diameter, 160 cm long). Turtles were placed in dorsal recumbence and endoscope was inserted through the vent. In the distal part of the proctodeum, phallus or clitoris were easily visualized. A finger and thumb were placed around the vent to act as a valve in order to control the fluid infusion. Flushing the cloaca with warm saline and 0.6% lidocaine allowed clear view. The urethral orifice was located centrally within the urogenital sinus. Further proximally, the slit of the urodeum with the distal sphincter of the colon could be visualized. Passing gently through the urethral orifice allowed direct visualization of the urinary bladder. After withdrawing and re-directing the endoscope into the coprodeum, the terminal part of the intestine was reached. From 31 loggerhead turtles examined, fishing lines were found in 23 animals. Cloacoscopy proved to be a feasible diagnostic method and it is suggested as a routine diagnostic tool for clinical assessment of loggerhead turtle patients.

Development of the Stiffenable Exoskeleton Device for a Colonoscopy

Colonoscopy provides a minimally invasive tool for examining and treating the colon without surgery, but current colonoscope designs still cause a degree of pain and mechanical trauma to the colon wall. The most common colonoscopes are long tubes inserted through the rectum with fiber optic lights, cameras, and biopsy tools on the distal end. The stiffness required to support these tools makes it difficult for the scopes to navigate the twisted path of the colon without causing mechanical trauma inside the colon wall or distorting its shape. The shaft of the colonoscope often causes looping (alpha, reverse alpha, or n), and it is very difficult to advance the distal tip of the colonoscope with looping. In order to avoid looping and minimize mechanical trauma, the author expanded on a design by Zehel et al., who proposed surrounding a flexible colonoscope with an external exoskeleton structure with controllable stiffness. The stiffenable exoskeleton device is comprised of rigid, articulating tubular units, which are stiffened or relaxed by four control cables. The stiffened or relaxed exoskeleton device guides navigation and provides stability for the colonoscope when it protrudes beyond the exoskeleton device for examination and procedures. This research determined the design requirements of such an exoskeleton device and tested requirements of such an exoskeleton device and tested its behavior in a colonoscopy training model. Moreover, the stiffenable exoskeleton device can be operated in purely a mechanical way, which is safe as a class II medical device, and no additional modification of the colonoscope is needed to use the stiffenable exoskeleton device. Colonoscopy training model is used to test the stiffenable exoskeleton device. First, the endoscopist inserted the colonoscope into the colonoscopy training model up to the end of the stiffenable exoskeleton device along the shaft of the colonoscope to the distal tip of the colonoscope, and then locked the stiffenable exoskeleton device and advanced the shaft of the colonoscope to examine the colon. When the distal tip reached the cecum, he or she unlocked the stiffenable exoskeleton device, retracted the shaft of the colonoscope and the stiffenable exoskeleton device, and checked for polyps or other colon disease. Also, the endoscopist can insert the stiffenable exoskeleton device and a colonoscope alternatively by stiffening and releasing the exoskeleton device. In that way, endoscopist can advance the colonoscope and the exoskeleton structure inch-by-inch without causing mechanical trauma in the rectum and the sigmoid colon. The endoscopist tested the stiffenable exoskeleton device using the colonoscopy training model and fulfilled its objectives. Several other diagnostic procedures involving the stomach, esophagus and the nose could also benefit due to the improvements provided by the stiffenable exoskeleton technology.