A modular magnetic anastomotic device for minimally invasive digestive anastomosis: proof of concept and preliminary data in the pig model

Background: The aim of our study was to assess the feasibility of minimally invasive digestive anastomosis using a modular flexible magnetic anastomotic device made up of a set of two flexible chains of magnetic elements. The assembly possesses a non-deployed linear configuration which allows it to be introduced through a dedicated small-sized applicator into the bowel where it takes the deployed form. A centering suture allows the mating between the two parts to be controlled in order to include the viscerotomy between the two magnetic rings and the connected viscera. Methods and procedures: Eight pigs were involved in a 2-week survival experimental study. In five colorectal anastomoses, the proximal device was inserted by a percutaneous endoscopic technique, and the colon was divided below the magnet. The distal magnet was delivered transanally to connect with the proximal magnet. In three jejunojejunostomies, the first magnetic chain was injected in its linear configuration through a small enterotomy. Once delivered, the device self-assembled into a ring shape. A second magnet was injected more distally through the same port. The centering sutures were tied together extracorporeally and, using a knot pusher, magnets were connected. Ex vivo strain testing to determine the compression force delivered by the magnetic device, burst pressure of the anastomosis, and histology were performed. Results : Mean operative time including endoscopy was 69.2±21.9min, and average time to full patency was 5days for colorectal anastomosis. Operative times for jejunojejunostomies were 125, 80, and 35min, respectively. The postoperative period was uneventful. Burst pressure of all anastomoses was ≥110mmHg. Mean strain force to detach the devices was 6.1±0.98 and 12.88±1.34N in colorectal and jejunojejunal connections, respectively. Pathology showed a mild-to-moderate inflammation score. Conclusions: The modular magnetic system showed enormous potential to create minimally invasive digestive anastomoses, and may represent an alternative to stapled anastomoses, being easy to deliver, effective, and low cost

Endoluminal surgical triangulation: overcoming challenges of colonic endoscopic submucosal dissections using a novel flexible endoscopic surgical platform: feasibility study in a porcine model

Background: Colonic endoscopic submucosal dissection (ESD) is challenging as a result of the limited ability of conventional endoscopic instruments to achieve traction and exposure. The aim of this study was to evaluate the feasibility of colonic ESD in a porcine model using a novel endoscopic surgical platform, the Anubiscope (Karl Storz, Tüttlingen, Germany), equipped with two working channels for surgical instruments with four degrees of freedom offering surgical triangulation. Methods: Nine ESDs were performed by a surgeon without any ESD experience in three swine, at 25, 15, and 10cm above the anal verge with the Anubiscope. Sixteen ESDs were performed by an experienced endoscopist in five swine using conventional endoscopic instruments. Major ESD steps included the following for both groups: scoring the area, submucosal injection of glycerol, precut, and submucosal dissection. Outcomes measured were as follows: dissection time and speed, specimen size, en bloc dissection, and complications. Results: No perforations occurred in the Anubis group, while there were eight perforations (50%) in the conventional group (p=0.02). Complete and en bloc dissections were achieved in all cases in the Anubis group. Mean dissection time for completed cases was statistically significantly shorter in the Anubis group (32.3±16.1 vs. 55.87±7.66min; p=0.0019). Mean specimen size was higher in the conventional group (1321±230 vs. 927.77±229.96mm2; p=0.003), but mean dissection speed was similar (35.95±18.93 vs. 23.98±5.02mm2/min in the Anubis and conventional groups, respectively; p=0.1). Conclusions: Colonic ESDs were feasible in pig models with the Anubiscope. This surgical endoscopic platform is promising for endoluminal surgical procedures such as ESD, as it is user-friendly, effective, and saf

Acute Liver Failure Secondary to Hepatic Infiltration of Malignant Melanoma

Acute liver failure due to malignant melanoma is uncommon. We presents a case of acute liver failure secondary to hepatic infiltration of a malignant melanoma. An 86-year-old man was admitted with elevated liver enzymes and an increased lactate dehydrogenase level. His condition progressed to acute liver failure, but the etiology of liver failure was unclear. Esophagogastroduodenoscopy was performed to evaluate dyspepsia, which showed signs indicative of malignant melanoma. Based on the endoscopy findings and elevated liver enzyme levels, liver biopsy was performed to confirm the presence of malignant melanoma. Hepatic infiltration of malignant melanoma was observed histologically. However, massive and diffuse liver metastasis is very rare and difficult to identify on imaging studies. If the etiology of liver failure is unclear, diffuse metastatic melanoma infiltration should be considered as differential diagnosis. Early liver biopsy can help to clarify the diagnosis

Differential Cytokine Utilization and Tissue Tropism Results in Distinct Repopulation Kinetics of Naïve vs. Memory T Cells in Mice

Naïve and memory T cells co-exist in the peripheral T cell pool, but the cellular mechanisms that maintain the balance and homeostasis of these two populations remain mostly unclear. To address this question, here, we assessed homeostatic proliferation and repopulation kinetics of adoptively transferred naïve and memory T cells in lymphopenic host mice. We identified distinct kinetics of proliferation and tissue-distribution between naïve and memory donor T cells, which resulted in the occupancy of the peripheral T cell pool by mostly naïve-origin T cells in short term (<1 week), but, in a dramatic reversal, by mostly memory-origin T cells in long term (>4 weeks). To explain this finding, we assessed utilization of the homeostatic cytokines IL-7 and IL-15 by naïve and memory T cells. We found different efficiencies of IL-7 signaling between naïve and memory T cells, where memory T cells expressed larger amounts of IL-7Rα but were significantly less potent in activation of STAT5 that is downstream of IL-7 signaling. Nonetheless, memory T cells were superior in long-term repopulation of the peripheral T cell pool, presumably, because they preferentially migrated into non-lymphoid tissues upon adoptive transfer and additionally utilized tissue IL-15 for rapid expansion. Consequently, co-utilization of IL-7 and IL-15 provides memory T cells a long-term survival advantage. We consider this mechanism important, as it permits the memory T cell population to be maintained in face of constant influx of naïve T cells to the peripheral T cell pool and under competing conditions for survival cytokines