Mesenteric Injection Research Articles

VS 07 - OGC Visualisation of variant thoracic duct anatomy using mesenteric injection of Indocyanine Green (ICG) and early ligation of the high thoracic duct can decrease the occurrence of chyle leaks after robotic oesophagectomies: Insights from a single-centre case series

Abstract Background Chyle leak (CL) remains a relatively common complication following oesophagectomy, with reported incidence up to 9%, and is associated with significant clinical and financial consequences. We assess the feasibility and utility of fluorescence to visualise the thoracic duct (TD), using an easy-to perform intraoperative technique. This involves injecting ICG into the small bowel mesentery during robotic Ivor-Lewis oesophagectomy (RAMIO) and early ligation of the thoracic duct above azygos arch. Method Between 2022-2024, 36 patients undergoing RAMIO received ICG (2ml of 2.5mg/mL solution) injected in the root of jejunal mesentery by endoscopic needle injector via laparoscopic port during the abdominal phase. A minimum of 60min following injection, fluoroscopic visualisation of TD anatomy was performed with Firefly® system. During the initial phase of the thoracic stage, the thoracic duct was located in the upper mediastinum, just above azygos arch, and was securely clipped using the Hem-o-Lok® system. Results Successful TD imaging using ICG-fluorescence was achieved in all 36 patients undergoing RAMIO. Variations from the standard single duct structure were observed in 4 (11%) of patients. Specifically, two cases exhibited duct bifurcation at the level of the azygos arch, one case had branching in the lower mediastinum, and another case demonstrated branching from the main duct over the thoracic aorta. All observed branches were individually clipped with Hem-o-Lok® system. Two individuals (5.5%) experienced low-volume chyle-leak post-operatively, which was successfully managed conservatively. No chyle leaks were detected at the end of the surgery in any of the cases. Conclusion In our single-centre experience, fluorescence visualisation of the thoracic duct during RAMIO by intraoperative mesenteric injection of ICG is an easily performed, reproducible technique which can assist in the visualisation of variant TD anatomy and reduce the incidence of CL. In addition to its impact on clinical outcomes and healthcare costs, the approach can also support a better appreciation of TD anatomy among surgeons.

MSCs-exosomes can promote macrophage M2 polarization via exosomal miR-21-5p through Mesenteric injection: a promising way to attenuate murine colitis.

Exosome-based therapies are gaining increasing attention, with growing evidence suggesting a link between alterations in mesentery adipose tissue (MAT) and intestinal disease in Crohn's disease (CD). However, the specific mechanism by which mesenchymal stem cells (MSCs)-Exos may alleviate colitis through targeting MAT remains not fully understood. Human umbilical cord MSCs (HucMSCs) were cultured to isolate the corresponding exosomes (HucMSCs-Exos), which were confirmed by their morphology, size distribution, and expression of markers. In vivo, 2,4,6-trinitrobenzenesulfonic acid solution (TNBS) and dextran sodium sulfate (DSS) -induced mouse colitis models were used to detect the therapeutic effects of HucMSCs-Exos. ELISA, qRT-PCR, western blotting, and immunofluorescence determined the expression of key molecules. Luciferase reporter assay was used to confirm the relationship between miR-21-5p and SPRY2. Exosomes treatment through mesenteric injection demonstrated therapeutic effects on mesenteric inflammation and colitis. These therapeutic benefits were contingent on macrophages, significantly facilitating the M2 polarization of mesenteric macrophages. The expression data from GSE159814 and GSE211008 revealed that exosomal miR-21-5p was enriched in HucMSCs-Exos and could be delivered to macrophages. Additionally, the results indicated that miR-21-5p could directly target the 3'UTR of SPRY2 and activate the phosphorylation of ERK to modify macrophage phenotypes. Mechanistically, exosomal miR-21-5p derived from HucMSCs could promote macrophage M2 polarization via the SPRY2/ERK axis. Mesenteric injection of HucMSCs-Exos significantly alleviates mesenteric inflammation and colitis by promoting mesenteric macrophage M2 polarization, making it a promising approach to treat colitis and suggesting therapeutic potential role of exosomal miR-21-5p in CD.

Near infra-red fluorescence identification of the thoracic duct to prevent chyle leaks during oesophagectomy

BackgroundChyle leaks following oesophagectomy are a frustrating complication of surgery with considerable morbidity. The use of near infra-red (NIR) fluorescence in surgery is an emerging technology and the use of fluorescence to identify the thoracic duct has been demonstrated in animal work and early human case reports. This study evaluated the use mesenteric and enteral administration of indocyanine green (ICG) in humans to identify the thoracic duct during oesophagectomy.MethodsPatients undergoing oesophagectomy were recruited to the study. Administration of ICG via an enteral route or mesenteric injection was evaluated. Fluorescence was assessed using a NIR fluorescence enabled laparoscope system with a visual scoring system and signal to background ratios. Visualisation of the thoracic duct under white light and NIR fluorescence was compared as well as any identification of active chyle leak. Patients were followed up post-operatively for adverse events and chyle leak.Results20 patients received ICG and were included in the study. The enteral route failed to fluoresce the thoracic duct. Mesenteric injection (17 patients) identified the thoracic duct under fluorescence prior to white light in 70% of patients with a mean signal to background ratio of 5.35. In 6 participants, a possible active chyle leak was identified under fluorescence with 4 showing active chyle leak from what was identified as the thoracic duct.ConclusionThis study demonstrates that ICG administration via mesenteric injection can highlight the thoracic duct during oesophagectomy and may be a potential technology to reduce chyle leak following surgery.Clinical trial registrationClinical trials.gov (NCT03292757).

Glycans of Schistosoma mansoni and keyhole limpet haemocyanin induce hepatic granulomas in vivo

Schistosoma mansoni eggs trapped in the liver of an infected host cause the major pathological manifestations of schistosomiasis. Miracidia within the deposited eggs secrete soluble egg antigens (SEA) that induce periovular granuloma formation, which may lead to severe hepatic fibrosis. Several reports have highlighted the immunomodulatory capacities of carbohydrate determinants present in the glycoproteins of SEA. These glycans contain among others the immunogenic Galβ1-4(Fucα1-3)GlcNAc (Lewis X) and GalNAcβ1-4(Fucα1-2Fucα1-3)GlcNAc (LDN-DF) elements. Due to cross-reactivity with schistosomal glycan antigens, keyhole limpet haemocyanin (KLH) has been used extensively for diagnostic and therapeutic studies on schistosomiasis. In the present study, a granulomatous response with numerous eosinophils towards SEA- and KLH-coated beads implanted in the liver by mesenteric injection was observed. Immunophenotyping of these experimentally induced granulomas for cellular recruitment, chemokines, adhesion and extracellular matrix proteins revealed very close resemblance with hepatic lesions evoked by native schistosome eggs, hence demonstrating the usefulness of the bead model, in general, as well as of KLH as a model antigen to study the immunopathological mechanisms of schistosome infections. While trypsin digestion of KLH did not alter its antigenic characteristics, beads coated with SEA or KLH treated with sodium periodate to destroy the immunological properties of their carbohydrate chains, yielded only a monolayer of macrophages similar to negative control beads. Up-regulation of ICAM-1, LFA-1 and fibronectin in SEA-induced granulomas and in native and trypsinised KLH-induced granulomas indicates a major role of the carbohydrate elements of SEA and KLH in the initiation and homeostasis of the inflammatory response. These data provide new insights in the complex and multifactorial carbohydrate-dependent host–parasite immunological interactions.

Glycans of Schistosoma mansoni and keyhole limpet haemocyanin induce hepatic granulomas in vivo

Schistosoma mansoni eggs trapped in the liver of an infected host cause the major pathological manifestations of schistosomiasis. Miracidia within the deposited eggs secrete soluble egg antigens (SEA) that induce periovular granuloma formation, which may lead to severe hepatic fibrosis. Several reports have highlighted the immunomodulatory capacities of carbohydrate determinants present in the glycoproteins of SEA. These glycans contain among others the immunogenic Galβ1-4(Fucα1-3)GlcNAc (LewisX) and GalNAcβ1-4(Fucα1-2Fucα1-3)GlcNAc (LDN-DF) elements. Due to cross-reactivity with schistosomal glycan antigens, keyhole limpet haemocyanin (KLH) has been used extensively for diagnostic and therapeutic studies on schistosomiasis. In the present study, a granulomatous response with numerous eosinophils towards SEA- and KLH-coated beads implanted in the liver by mesenteric injection was observed. Immunophenotyping of these experimentally induced granulomas for cellular recruitment, chemokines, adhesion and extracellular matrix proteins revealed very close resemblance with hepatic lesions evoked by native schistosome eggs, hence demonstrating the usefulness of the bead model, in general, as well as of KLH as a model antigen to study the immunopathological mechanisms of schistosome infections. While trypsin digestion of KLH did not alter its antigenic characteristics, beads coated with SEA or KLH treated with sodium periodate to destroy the immunological properties of their carbohydrate chains, yielded only a monolayer of macrophages similar to negative control beads. Up-regulation of ICAM-1, LFA-1 and fibronectin in SEA-induced granulomas and in native and trypsinised KLH-induced granulomas indicates a major role of the carbohydrate elements of SEA and KLH in the initiation and homeostasis of the inflammatory response. These data provide new insights in the complex and multifactorial carbohydrate-dependent host–parasite immunological interactions.

CC531s colon carcinoma cells induce apoptosis in rat hepatic endothelial cells by the Fas/FasL-mediated pathway.

The mechanisms involved in colorectal carcinoma with liver metastasis are not well known. Metastasizing colon carcinoma cells express more FasL than primary colon carcinoma cells and cancer cells induce apoptosis in hepatocytes by the Fas/FasL pathway. Therefore, this study focused on Fas/FasL expression and functionality in rat liver sinusoidal endothelial cells (LSECs) and CC531s colon carcinoma cells in vitro and in vivo. RT-PCR and immunochemistry revealed Fas and FasL in LSECs and CC531s, respectively. Functionality of Fas was assessed in vitro by incubation with human recombinant FasL (1-100 ng/ml) with or without enhancer. At concentrations of 10 and 100 ng/ml with enhancer, respectively 21% and 44% of endothelial cells showed signs of apoptosis using Hoechst 33342/propidium iodide staining and electron microscopy. In co-cultures, apoptosis could be detected in endothelial cells neighboring the CC531s and could be inhibited by an antagonistic FasL antibody. Moreover, 18 h after mesenteric injection of CC531s, the sinusoidal endothelium revealed disruption. In conclusion, (i). CC531s cells induce apoptosis in LSECs in vitro by using Fas/FasL; (ii). CC531s cells damage the sinusoidal endothelial lining in vivo; and (iii). this might provide FasL-positive tumor cells a gateway towards the hepatocytes.

Schistosomal granuloma modulation. II. Specific immunogenic carbohydrates can modulate schistosome-egg-antigen-induced hepatic granuloma formation.

To further investigate the factors involved in the modulation of the schistosomal granuloma, mice were primed with immunogenic carbohydrates which were common to soluble egg antigen (SEA) and adult worm antigen. Mice sensitized with LewisX trisaccharide or lacto-N-fucopentaose-III (LNFP-III) displayed an increased cellular response towards SEA-coupled beads implanted in the liver by mesenteric injection, resulting in the formation of larger periparticular granulomas. When animals were sensitized with bovine serum albumin or a structurally related carbohydrate, an accelerated response was not seen. Since LNFP-III is built up of LewisX molecules, and LewisX carbohydrates are common to SEA and worm antigens such as the gut-secreted antigens CCA and CAA (two antigens that could prime egg-antigen-induced granuloma formation), this may explain why adult, live Schistosoma mansoni worms positively modulate egg-antigen-induced hepatic granuloma formation in the murine host. These observations provide new insights into the role of carbohydrates in parasite-host immunity and may yield important implications for choosing worm-derived antigens for the development of anti-schistosome vaccines.

Mechanical pumping of portal blood to the liver: hemodynamic effects of a new experimental treatment for portal hypertension

Background/Aims: It has been suggested that mechanical pumping of portal blood to the liver may correct portal hypertension while increasing portal flow to the liver, which may enhance liver function in cirrhosis. However, the hemodynamic effects of this procedure are unknown. The present study investigated these issues in rats with portal hypertension due to portal vein stenosis. Methods: Mechanical pumping of portal blood to the liver was established by an extracorporeal shunt bypassing the portal vein stenosis, connected to a continuous withdrawal/infusion pump. Portal pressure, portal-systemic shunting (mesenteric injection of Cr-51 microspheres, n=10), mesenteric artery blood flow (perivascular Transonic flowmeter, n=7) and systemic hemodynamics and regional blood flows (left ventricle injection of Ce-141 microspheres, n=15), were measured at pumping rates of 0, 3 and 6 ml·min −1. Results: Mechanical pumping of portal blood to the liver caused a marked decrease in portal pressure (from 17±1 to 12.6±1 and 9.4±.9 mmHg at pumping rates of 0, 3 and 6 ml·min −1) and portal-systemic shunting (from 97±4 to 70±4 and 51±6% respectively) ( p<0.001). However, there were no significant changes in mesenteric artery flow (5.5±3 vs 5.6±3 ml·min −1·100 g −1), suggesting that all blood pumped to the liver was withdrawn from that circulating through the collaterals. Moreover, there were no changes in mean arterial pressure, cardiac index, peripheral resistance and splanchnic arteriolar resistance. Conclusions: The short-term mechanical pumping of portal blood to the liver effectively decreases portal pressure and portal-systemic shunting and has no significant effects on systemic and splanchnic hemodynamics in portal hypertensive rats.

Angiodysplasia of the cecum: colonoscopic diagnosis

Arteriography was performed to determine if similar vascular malformations could be detected in the small bowel. Selective superior mesenteric injection demonstrated the cecal vascular malformation which was supplied by the cecal branch of the ileocolic artery and displayed typical early venous filling. No additional lesions were detected by superior or inferior mesenteric angiographic studies. At operation, the cecal lesion was not found even by careful inspection. Because of the preoperative documentation of a vascular malformation in the cecum, a right hemicolectomy was performed. Gross pathologic inspection was unrewarding, and attempts at arteriography in the resected specimen were unsuccessful. However, the lesion was identified after serial microscopic sectioning. Outpatient followup of the patient for 6 months revealed resolution of the anemia. Neither black nor bloody stools have been noted, and tests for occult blood in the stool have been negative. MORPHOLOGIC FINDINGS The specimen received in the laboratory consisted of a segment of cecum and ascending colon 30 cm in length with a normal appendix and a 4.5 cm segment of terminal ileum. Preliminary inspection showed no mucosal or mural abnormalities throughout. Utilizing information provided by the endoscopist and radiologist, a 3 cm broad crescentic strip of colon over a radius 7 cm from the ileocecal valve was isolated and inspected under a dissecting microscope. This disclosed a 1.2 cm area of faint hypervascularity without mucosal defect. The entire strip of colon was step-sectioned revealing, in this latter region, microscopic evidence of a fairly discrete vascular abnormality. The lesion consisted of a submucosal tangle of dilated arterial and venous, thick-walled blood vessels indicative of marked tortuosity (Figure 2). At one plane of cut, an artery and vein were found in very close juxtaposition, and the possibility of their communicating was suggested strongly. Although a small vein in one section suggested organizing thrombotic material with early angiomatoid formation, no overt embolization was discovered. Irregular and eccentric diffuse hyperplastic sclerosis of the intima of both arteries and veins was noted. Thin-walled vascular channels penetrated the muscularis mucosa terminating in acongeries ofendothelial lined, dysplastic appearing, lake-like spaces throughout the tunica propria in this area. Capillary telangiectasia was noted likewise throughout the muscularis propria and serosa. There was an area of healed erosion of the overlying mucosa. DISCUSSION Previous to the studies reported by Baum and his colleagues7,. a decade ago, reports of vascular lesions of the gastrointestinal tract were rare.g,'0 However, since that Angiodysplasia of the cecum: colonoscopic diagnosis Richard M. Skibba, MD* William A. Hartong, MD Frank A. Mantz, MD Daniel R. Hinthorn, MD James B. Rhodes, MD Department of Internal Medicine and Department of Pathology University of Kansas Medical Center Kansas City, Kansas

Hepatic Lobar Distribution of Splenic and Mesenteric Blood Flow in Man

The hepatic lobar distribution of 131I- labeled serum albumin injected into the superior mesenteric and splenic arteries was studied in 6 normal subjects and in 8 patients with portal hypertension to determine whether streamlining of flow in the portal vein leads to selective hepatic distribution of portal inflow. Isotope dilution curves recorded simultaneously from the right and left (or sagittal) hepatic veins were similar in most patients whether injection was made into the superior mesenteric or splenic arteries. The ratio of the area of curves recorded from the right to that from the left (or sagittal) hepatic veins averaged 0.91 after superior mesenteric injection and 0.95 after splenic injection. The absence in man of a consistent pattern of hepatic distribution of portal inflow makes this explanation for the localization of blood-borne hepatic lesions untenable.