Electromagnets for an endoscopic anastomosis tool in the colon

The goal of our research work is the development of a novel endoscopic anastomosis device for the colon. One of the main challenges in this context is the application of forces at the endoscope tip to rejoin the two bowel endings. Thus, we focus on a magnetic two-part compression implant approach. The implant halves are detached from the applicator units by means of electromagnets. In this contribution we present the results of our experiments to determine the implant design with special focus on tissue compression forces and the resultant electromagnet dimensioning to estimate size requirements of the application/detachment system. To achieve the targeted compression forces derived from literature, we used cubic N52 magnetized neodymium magnets1 with a side length of 5 mm and mild steel screws. For these magnets, we evaluated a required electromagnetic repulsion force of 4.1 N. For the electromagnetic detachment system this led to the need for 166 windings for the coils on oral side, and 146 windings for the coils at the aboral side. Based on these requirements, a colonoscope diameter (~14 mm) increase of 10.6 mm on the oral side and of 12 mm on the aboral side due to the application device must be assumed. Nevertheless, this diameter still remains within the size range of other colonoscopic tools, such as e.g., circular staplers.

Outcomes associated with the use of a new powered circular stapler for left-sided colorectal reconstructions: a propensity score matching-adjusted indirect comparison with manual circular staplers

Background This was a retrospective, matching-adjusted indirect comparison of clinical outcomes between patients from a single-arm trial of the ECHELON CIRCULAR™ Powered Stapler (ECP) and those from a historical cohort of patients who underwent left-sided colorectal resection using conventional manual circular staplers, extracted from the Premier Healthcare Database. Methods Patients in the ECP trial cohort were propensity score matched to those in the historical cohort through nearest neighbor matching. Outcomes included 30-day readmission rates; length of stay (LOS) for the index admission; rates of anastomotic leak, pelvic abscess, ileus/small bowel obstruction, infection, bleeding, and stoma creation. Results The study included 168 patients in the ECP trial cohort and 4544 patients in the historical cohort; 165 ECP trial patients were matched to 1348 historical cohort patients. After matching, conversions were more prevalent in the historical cohort than the ECP trial cohort (4.2% ECP vs. 10.2% historical, p = 0.001). Relative to the historical cohort, the ECP trial cohort had statistically significant lower rates of 30-day inpatient readmission (6.1% vs. 10.8%, p = 0.019), anastomotic leak (1.8% vs. 6.9%, p < 0.001), ileus/small bowel obstruction (4.8% vs. 14.7%, p < 0.001), infection (1.8% vs. 5.7%, p = 0.001), and bleeding (1.8% vs. 9.2%, p < 0.001) during the index admission or within 30 days thereafter. No statistically significant differences in rates of pelvic abscess, stoma creation, or LOS were found between the two cohorts. Three sensitivity analyses to address the difference in conversion rates yielded largely consistent results, with loss of statistical significance for inpatient admission in some cases. This study is limited by its potential for differences in unmeasurable factors between the ECP trial and historical cohorts. Conclusions In this study, the ECP trial cohort had lower incidence proportions of several surgical complications as compared with the historical cohort. Further controlled prospective clinical studies are needed to confirm the validity of this finding.

Preventive procedure for stenosis after esophagojejunostomy using a circular stapler and transorally inserted anvil (OrVil™) following laparoscopic proximal gastrectomy and total gastrectomy involving reduction of anastomotic tension

Background Recently, due to increasing reports of stenosis after esophagojejunostomy created using circular staplers and a transorally inserted anvil (OrVil™) following laparoscopic proximal gastrectomy (LPG) and total gastrectomy (LTG), linear staplers are being used instead. We investigated our preventive procedure for esophagojejunostomy stenosis following use of circular staplers. Methods Since the anastomotic stenosis is considered to be mainly caused by tension in the esophageal and jejunal stumps at the anastomotic site, we have been performing procedures to relieve this tension, by cutting off the rubber band and pushing the shaft of the circular stapler toward the esophageal side, since July 2015. We retrospectively compared the incidence of anastomotic stenosis in cases of LPG and LTG performed before July 2015 (early phase, 30 cases) versus those performed after this period (later phase, 22 cases). Results Comparison of the incidence of anastomotic stenosis according to the type of surgery, LPG or LTG, and between the two time periods versus all cases, indicated a significantly lower incidence in the later phase than in the early phase (4.5 vs. 26.7%, p < 0.05), especially for LPG (0 vs. 38.5%, p < 0.05). Conclusions It is possible to use a circular stapler during laparoscopic esophagojejunostomy, as with open surgery, if steps to reduce tension on the anastomotic site are undertaken. These procedures will contribute to the spread of safe and simple laparoscopic anastomotic techniques.

Preventive Procedure for Stenosis After Esophagojejunostomy Using A Circular Stapler and Transorally Inserted Anvil (OrVilTM) Following Laparoscopic Proximal Gastrectomy and Total Gastrectomy Involving Reduction of Anastomotic Tension

Background: Recently, due to increasing reports of stenosis after esophagojejunostomy created using circular staplers and a transorally inserted anvil (OrVilTM) following laparoscopic proximal gastrectomy (LPG) and total gastrectomy (LTG), linear staplers are being used instead. We investigated our preventive procedure for esophagojejunostomy stenosis performed using circular staplers.Methods Since the anastomotic stenosis is considered to be mainly caused by tension in the esophageal and jejunal stumps at the anastomotic site, we have been performing procedures to relieve this tension, by cutting off the rubber band and pushing the shaft of the circular stapler toward the esophageal side, since July 2015. We retrospectively compared the incidence of anastomotic stenosis in cases of LPG and LTG performed before July 2015 (early phase, 30 cases) versus those performed after this period (later phase, 22 cases).Results Comparison of the incidence of anastomotic stenosis according to the type of surgery, LPG or LTG, and between the two time periods versus all cases, indicated a significantly lower incidence in the later phase than in the early phase (4.5% vs. 26.7%, p<0.05), especially for LPG (0% vs. 38.5%, p<0.05).Conclusions It is possible to use a circular stapler during laparoscopic esophagojejunostomy, as with open surgery, if steps to reduce tension on the anastomotic site are undertaken. These procedures will contribute to the spread of safe and simple laparoscopic anastomotic techniques.