Morphometric study of the layers of the canine small intestine at five sampling sites

The Use of Newly Synthesized Composite Scaffolds for Bone Regeneration - A Review of Literature

At present, clamping of the portal triad is a widespread surgical procedure in hospitals. Such an operation can prevent pathological changes in the organs. However, the optimal time for clamping remains unclear. To determine the starting time of irreversible morphological changes in the small intestine due to the clamping of the portal triad. The study was carried out on rats (n=94). Animals were randomly subdivided into 4 groups based on the duration of clamping of the portal triad (PT): I control group (CG; without clamping the PT; n=10); II intervention group (6-IG; clamping PT for 6 min; n=28); III intervention group (12-IG; clamping time of the PT for 12 min; n=28); IV intervention group (24-IG; clamping time of the PT for 24 min; n=28). In groups 6- IG, 12-IG, 24-IG, after clamping the portal triad, animals were withdrawn from the experiment after 3 hours, 6 hours, 12 hours, 1 day, 3 days and 7 days. Morphological changes in the small intestine were assessed by measuring the diameter of the lumen of micro-vessels. In addition, the mortality in the groups was analysed as well. In the CG group, the diameter of the arterioles of the small intestine was 34±4 μm, the diameters of pre-capillaries were 15±2μm, the capillaries were 5.4±1 μm, the post-capillaries were 18±2 μm, and the diameter of the lumen of the venues was 40±3 μm. In the 6-IG group (on the 3rd day), the structure of the small intestine showed the recovery signs. By the 7th day, the indicators returned to their original values. In the 12-IG group, the parameters of the small intestine were restored on the seventh day that corresponds to the usual course of the disease. However, in the 24-IG group, changes in these organs persisted until the end of the study. No deaths were reported in the CG and 6-IG animal groups. Mortality among rats of the 12-IG group was 14.3%, while in the 24-IG group with PT clamping for 24 minutes it was 42.8%, respectively. The morphological changes in the microvasculature of the small intestine after 6-minute PT clamping showed a tendency to recover (back to the control parameters). Nevertheless, after 24 minutes of clamping, the changes in the intestinal tissue were irreversible.

From Chihuahua to Saint-Bernard: how did digestion and microbiota evolve with dog sizes

Health and well-being of dogs are of paramount importance to their owners. Digestion plays a key role in dog health, involving physicochemical, mechanical and microbial actors. However, decades of breeding selection led to various dog sizes associated with different digestive physiology and disease sensitivity. Developing new products requires the consideration of all the multi-faceted aspects of canine digestion, the evaluation of food digestibility, drug release and absorption in the gut. This review paper provides an exhaustive literature survey on canine digestive physiology, focusing on size effect on anatomy and digestive parameters, with graphical representation of data classified as "small", "medium" and "large" dogs. Despite the huge variability between protocols and animals, interesting size effects on gastrointestinal physiology were highlighted, mainly related to the colonic compartment. Colonic measurements, transit time permeability, fibre degradation, faecal short-chain fatty acid concentration and faecal water content increase while faecal bile acid concentration decreases with body size. A negative correlation between body weight and Proteobacteria relative abundance was observed suggesting an effect of dog body size on faecal microbiota. This paper gathers helpful in vivo data for academics and industrials and supports the development of new food and pharma products to move towards canine personalized nutrition and health.

Ex vivo ultrasonographic and histological morphometry of small intestinal wall layers in horses

Ultrasonographic morphometry of wall layers is commonly used in veterinary patients with suspected small intestinal disease, however published studies comparing this method with histopathology in horses are limited. This prospective, methods comparison study compared the qualitative and quantitative characteristics of small intestinal wall layers using ex vivo high‐frequency ultrasound versus histopathology in a sample of 16 horses. Transverse section images of duodenum, distal jejunum, and ileum were acquired with a high‐frequency linear transducer (7–15 MHz). Transverse histological cryosections were obtained at the same level. Appearance and measurements of the intestinal wall layers were assessed on the ultrasonographic and histological images. High‐frequency scanning with the probe in close contact with the serosal surface of the equine intestinal wall allowed a clear and detailed definition of wall layers. A hyperechoic line was consistently detected within the tunica muscularis in all the intestinal tracts, corresponding histologically to the interface between its longitudinal and circular muscle layers. The overall trend of the values for wall layers thickness was comparable between ex vivo ultrasonography and histology. However, a poor agreement was found between the two methods for all layers. The ultrasonographic measurements were thicker compared to histological measurements, with the exception of the total wall and the muscular layer thicknesses. These layers were thinner on ultrasonography in the duodenum and in all the intestinal segments, respectively. Findings from the current study can be used as background for future ultrasonographic investigations of small intestinal diseases in horses.

Volume of saline (0.9% NaCl) solution required to reach maximum peristaltic pressure in cadaveric intact jejunal specimens from dogs of various sizes

OBJECTIVE

To compare the volume of saline (0.9% NaCl) solution required to reach a maximum intraluminal peristaltic pressure of 25 mm Hg in dogs of various sizes.

SAMPLES

25 grossly normal jejunal segments from 6 canine cadavers < 20 kg (small dogs) and 25 segments from 5 cadavers ≥ 20 kg (large dogs).

PROCEDURES

Jejunal specimens were obtained within 1.5 hours after euthanasia. Harvested tissue was transected into 12-cm-long segments, mesentery was trimmed, and each segment was measured from the antimesenteric to mesenteric serosal edges. A 10-cm segment was isolated with Doyen forceps, securing a pressure sleeve within the lumen. Intraluminal saline was infused, and the volume was recorded when a pressure of > 25 mm Hg was achieved. Data were analyzed only from specimens in which the pressure remained between 24 and 26 mm Hg for > 5 seconds.

RESULTS

Mean ± SD intestinal measurement for large dogs (17.82 ± 1.44 mm) was greater than that for small dogs (12.38 ± 1.38 mm) as was the volume of saline solution infused (17.56 ± 7.17 mL vs 3.28 ± 1.41 mL, respectively). The volume infused increased by 1.31 mL (95% CI, 1.08 to 1.18) for every 1-mm increase in intestinal measurement and by 1.06 mL (95% CI, 1.052 to 1.068) for every 1-kg increase in body weight.

CONCLUSIONS AND CLINICAL RELEVANCE

The volume of saline solution used for intestinal leak testing should be determined on the basis of patient intestinal measurement or body weight. In vivo studies are necessary to establish the optimal volume for intestinal leak testing.

Influence of layer separation on the determination of stomach smooth muscle properties

Uniaxial tensile experiments are a standard method to determine the contractile properties of smooth muscles. Smooth muscle strips from organs of the urogenital and gastrointestinal tract contain multiple muscle layers with different muscle fiber orientations, which are frequently not separated for the experiments. During strip activation, these muscle fibers contract in deviant orientations from the force-measuring axis, affecting the biomechanical characteristics of the tissue strips. This study aimed to investigate the influence of muscle layer separation on the determination of smooth muscle properties. Smooth muscle strips, consisting of longitudinal and circumferential muscle layers (whole-muscle strips [WMS]), and smooth muscle strips, consisting of only the circumferential muscle layer (separated layer strips [SLS]), have been prepared from the fundus of the porcine stomach. Strips were mounted with muscle fibers of the circumferential layer inline with the force-measuring axis of the uniaxial testing setup. The force-length (FLR) and force-velocity relationships (FVR) were determined through a series of isometric and isotonic contractions, respectively. Muscle layer separation revealed no changes in the FLR. However, the SLS exhibited a higher maximal shortening velocity and a lower curvature factor than WMS. During WMS activation, the transversally oriented muscle fibers of the longitudinal layer shortened, resulting in a narrowing of this layer. Expecting volume constancy of muscle tissue, this narrowing leads to a lengthening of the longitudinal layer, which counteracted the shortening of the circumferential layer during isotonic contractions. Consequently, the shortening velocities of the WMS were decreased significantly. This effect was stronger at high shortening velocities.

Gastrointestinal thickness, duration, and leak pressure of six intestinal anastomoses in dogs

OBJECTIVE

To compare leak pressures and construct completion time of six intestinal anastomoses and report normal canine gastrointestinal thickness.

STUDY DESIGN

Experimental study.

ANIMALS

Grossly normal jejunal segments (n = 140) from 10 fresh canine cadavers.

METHODS

Gastrointestinal thickness was recorded. Eight-centimeter cooled canine cadaveric jejunal segments were randomly assigned to a control group (20 segments) and six treatment groups (20 segments/group [10 constructs/group]): (1) handsewn anastomosis (HSA), (2) functional end-to-end stapled anastomosis (FEESA)-blue thoracoabdominal (TA; FEESA-TAB), (3) FEESA-green TA (FEESA-TAG), (4) FEESA TA-gastrointestinal anastomosis (GIA), (5) FEESA with suture oversew (FEESA-O), and (6) skin staples (SS). Construct assembly time, initial leak pressure (ILP), maximum intraluminal pressure (MIP), and leakage location were compared.

RESULTS

Initial leak pressures (mean ± SD) for control (308.38 ± 115.91 mm Hg), HSA (41.96 ± 15.97), FEESA-TAB (31.71 ± 15.71), FEESA-TAG (27.24 ± 14.11), FEESA-GIA (25.62 ± 11.22), FEESA-O (31.01 ± 17.38), and SS (44.42 ± 28.88) groups were compared. No difference in ILP (P > .24) or MIP (P > .17) was detected between treatment groups. Sutured anastomoses took up to 10 times longer to complete (P = .0025). The stomach, duodenum, jejunum, and ileum mural thicknesses (mean ± SD) were 3.99 ± 0.44 mm, 2.34 ± 0.16, 2.49 ± 0.28, and 2.30 ± 0.31, respectively.

CONCLUSION

The ILP of all anastomoses exceeded maximum intraluminal peristaltic pressures. Stapled anastomoses were faster to complete.

CLINICAL SIGNIFICANCE

All anastomoses may be considered when performing an intestinal resection and anastomosis, with stapled anastomoses resulting in a shorter surgical time. Canine intestinal thickness may warrant use of a larger staple size.

Risk Factors for Dehiscence of Stapled Functional End-to-End Intestinal Anastomoses in Dogs: 53 Cases (2001-2012)

OBJECTIVE

To identify risk factors for dehiscence in stapled functional end-to-end anastomoses (SFEEA) in dogs.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n = 53) requiring an enterectomy.

METHODS

Medical records from a single institution for all dogs undergoing an enterectomy (2001-2012) were reviewed. Surgeries were included when gastrointestinal (GIA) and thoracoabdominal (TA) stapling equipment was used to create a functional end-to-end anastomosis between segments of small intestine or small and large intestine in dogs. Information regarding preoperative, surgical, and postoperative factors was recorded.

RESULTS

Anastomotic dehiscence was noted in 6 of 53 cases (11%), with a mortality rate of 83%. The only preoperative factor significantly associated with dehiscence was the presence of inflammatory bowel disease (IBD). Surgical factors significantly associated with dehiscence included the presence, duration, and number of intraoperative hypotensive periods, and location of anastomosis, with greater odds of dehiscence in anastomoses involving the large intestine.

CONCLUSION

IBD, location of anastomosis, and intraoperative hypotension are risk factors for intestinal anastomotic dehiscence after SFEEA in dogs. Previously suggested risk factors (low serum albumin concentration, preoperative septic peritonitis, and intestinal foreign body) were not confirmed in this study.

Inflammatory bowel disease: clinical aspects and treatments

Inflammatory bowel disease (IBD) is defined as a chronic intestinal inflammation that results from host-microbial interactions in a genetically susceptible individual. IBDs are a group of autoimmune diseases that are characterized by inflammation of both the small and large intestine, in which elements of the digestive system are attacked by the body’s own immune system. This inflammatory condition encompasses two major forms, known as Crohn’s disease and ulcerative colitis. Patients affected by these diseases experience abdominal symptoms, including diarrhea, abdominal pain, bloody stools, and vomiting. Moreover, defects in intestinal epithelial barrier function have been observed in a number of patients affected by IBD. In this review, we first describe the types and symptoms of IBD and investigate the role that the epithelial barrier plays in the pathophysiology of IBD as well as the major cytokines involved. We then discuss steps used to diagnose this disease and the treatment options available, and finally provide an overview of the recent research that aims to develop new therapies for such chronic disorders.

Ultrasonographic measurement of the relative thickness of intestinal wall layers in clinically healthy cats

The normal sonographic thickness of the individual layers (ie, mucosa, submucosa, muscularis and subserosa-serosa) of the intestinal wall was evaluated in 20 clinically healthy cats. The mean thickness of the wall was 2.20, 2.22, 3.00 and 2.04 mm for duodenum, jejunum, ileum (fold) and ileum (between folds), respectively. The mean thickness of the mucosal layer was 1.27, 1.20, 0.46 and 0.49 mm for duodenum, jejunum, ileum (fold) and ileum (between folds), respectively, and its contribution to wall thickness was significantly greater than that of the other layers in the duodenum (57.7%) and jejunum (55.2%). The mean thickness of the submucosal layer was 0.36, 0.36, 1.49 and 0.53 mm for duodenum, jejunum, ileum (fold) and ileum (between folds), respectively, and its contribution to wall thickness was greater than that of the muscularis in the duodenum (16.3%), jejunum (16%) and ileum (fold) (49.8 %). The mean thickness of muscularis was 0.28, 0.35, 0.66 and 0.65 mm for duodenum, jejunum, ileum (fold) and ileum (between folds), respectively, with a corresponding contribution to wall thickness of 12.7 %, 14.4%, 22% and 31.6%. Finally, the mean thickness of serosa was 0.29, 0.31, 0.38 and 0.38 mm for duodenum, jejunum, ileum (fold) and ileum (between folds), respectively, with a corresponding contribution to wall thickness of 13.3%, 14.4%, 12.7 % and 18.7%. These values can provide baseline information that might be useful in evaluating intestinal disorders affecting preferentially some of the intestinal layers.