Effects of intraluminal pressure on regional blood flow in obstructed and unobstructed small intestines in the rat

Enochsson, Lars; Nylander, G; Ohman, U

doi:10.1016/0002-9610(82)90580-3

Cited by 37 publications

(16 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The propagation time was significantly increased proximal to the obstruction. By contrast, acute mechanical obstruction is characterized by a moderately decreased propagation time (as well as motor activity in general) proximally [24]. The increased propagation time in this study must be interpreted in light of the changes in wall morphology and distensibility.…”

Section: Discussionmentioning

confidence: 72%

“…The compensatory increase in wall thickness and collagen content is likely a biological countermeasure to protect the intestine from bursting at high wall stresses. However, it may also protect the intestine from vascular compromise occurring at lower pressures [24]. The increased synthesis of collagen is likely a reaction to increased forces acting on the intestinal wall during obstruction resulting in increased wall stresses and strains (Storkholm et al.…”

Section: Discussionmentioning

confidence: 98%

See 1 more Smart Citation

Spontaneous and Bolus-induced Motility in the Chronically Obstructed Guinea-Pig Small Intestine In vitro

2007

View full text Add to dashboard Cite

Partial obstruction of the small intestine results in dysmotility and morphometric changes proximal to the site of obstruction. However, our understanding of the relation between the morphometric remodeling and change in the motility pattern during chronic obstruction is sparse. The aim of this study was to investigate the effect of partial chronic intestinal obstruction on motility, morphology, and collagen content proximal and distal to the site of obstruction. Twenty guinea-pigs with partial intestinal obstruction and eight sham-operated controls lived for four weeks. Spontaneous and bolus-induced motility was recorded in isolated intestinal segments proximal and distal to the site of obstruction using a perfused low-compliance pressure-measuring system in vitro. After the motility experiments, the specimens were fixed at 2 kPa luminal distension pressure and sampled for histomorphometric determination of luminal radius, layer thickness, and wall thickness. Total wall collagen was also determined. The area under the curve (AUC) of spontaneous contractions and the amplitude, frequency, and AUC for the bolus-induced motility were higher in the proximal segments of the banded animals compared to distal segments and to the intestinal segments in the control animals (P < 0.05). The radius-to-thickness ratio was lowest in the proximal segments of the obstructed animals (P < 0.01). The collagen content was three times higher proximal to the site of obstruction when compared to distal locations and to the controls (P < 0.01). The AUC at 2 ml bolus injections plotted against the radius-to-thickness ratio showed a strong association (r = 0.97 for control, and r = 0.99 for obstruction, P < 0.01). No correlation was found between the collagen content and AUC. In conclusion, partial intestinal obstruction in guinea pigs caused pronounced changes in morphology and motility. An association was found between the radius-to-thickness ratio and bolus-induced motility.

show abstract

Section: Discussionmentioning

confidence: 72%

Section: Discussionmentioning

confidence: 98%

Spontaneous and Bolus-induced Motility in the Chronically Obstructed Guinea-Pig Small Intestine In vitro

2007

View full text Add to dashboard Cite

show abstract

“…We did not measure intraluminal pressure in vivo in this study. However, during acute obstruction in the intestine pressures of 20 mmHg (1 kPa = 7.5 mmHg) have been reported [38]. Such a pressure would generate stresses of approximately 35 kPa in the proximal segments in this study.…”

Section: Discussionmentioning

confidence: 79%

“…The association found between collagen content and mechanical properties at low and high stresses is important. Thus, the compensatory increase in wall thickness and collagen content may be seen as a countermeasure to protect the intestine not only from bursting at very high wall stresses, but also to protect the intestine from vascular compromise occurring at lower pressures [38] owing to compressive and tensile strains. The increased synthesis of collagen may be a reaction to increased wall stress induced by the obstruction.…”

Section: Discussionmentioning

confidence: 98%

Biomechanical Remodeling of the Chronically Obstructed Guinea Pig Small Intestine

et al. 2007

View full text Add to dashboard Cite

Small intestinal obstruction is a frequently encountered clinical problem. To understand the mechanisms behind obstruction and the clinical consequences, data are needed on the relation between the morphologic and biomechanical remodeling that takes place in the intestinal wall during chronic obstruction. We sought to determine the effect of partial obstruction on mechanical and morphologic properties of the guinea pig small intestine. Partial obstruction was created surgically in 2 groups of animals living for 2 and 4 weeks. Controls were sham operated and lived for 4 weeks. A combined impedance planimetry-high-frequency ultrasound system was designed to measure the luminal cross-sectional area and wall thickness. These measures were used to compute the circumferential stress and strain of the excised intestinal segments. The incremental elastic modulus was obtained by using nonlinear fitting of the stress-strain curve. Histologic analysis and the measurements of total wall collagen were also performed. The luminal cross-sectional area, wall thickness, and elastic modulus in circumferential direction increased in a time-dependent manner proximal to the obstruction site (P < 0.01), whereas no differences in these parameters were found distal to the obstruction site (P > 0.25). The circumferential stress-strain curves of the proximal segments in 2- and 4-week groups shifted to the left, indicating the intestinal wall became stiffer. Histologic examination revealed a massive increase in the thickness of the muscle layer especially the circular smooth muscle layer (P < 0.05). The collagen content proximal to the obstruction site was significantly larger in the partially obstructed animals compared to controls (P < 0.05). No difference was found distal to the obstruction site. Strong correlation was found between the collagen content and the elastic modulus at stress levels of 70 kPa stress (P < 0.01) and 10 kPa (P < 0.05) proximal to the obstruction site suggesting that the alteration of collagen has great impact on the mechanical remodeling. The morphologic and biomechanical remodeling likely influence the function of the intestine affected by partial obstructed intestine.

show abstract

“…Definitive surgery, however, must be performed within a short period of time. Otherwise, patient’s condition will deteriorate [13, 18]. In the current series, we could complete the procedure within a very short period of time, without failure of this simple device (such as slipping-out of the tubes).…”

Section: Discussionmentioning

confidence: 99%

A novel method for multiple bowel injuries: a pilot canine experiment

Lin

et al. 2017

World J Emerg Surg

View full text Add to dashboard Cite

BackgroundIntestinal ligation is the cornerstone for damage control in abdominal emergency, yet it may lead to bowel ischemia. Although intestinal ligation avoids further peritoneal cavity pollution, it may lead to an increased pressure within the bowel segments and rapid bacterial translocation. In this study, we showed that severed intestine could be readily reconnected by using silicon tubes and be secured by using rubber bands in a canine model.MethodsAdult Beagle dogs, subject to multiple intestinal transections and hemorrhagic shock by exsanguination, randomly received conventional ligation vs. silicon tubes reconnecting (n = 5 per group). Intestinal transections were carried out under general anesthesia after 24-h fasting. The abdomen was opened with a midline incision. The small intestine was severed at 50, 100, and 150 cm below the Treitz ligament. Hemorrhagic shock was established by streaming blood from the left carotid artery until the mean arterial pressure reached 40 mmHg in 20 min. Fluid resuscitation and surgery began 30 min after the establishment of hemorrhagic shock. Severed intestines were ligated or connected with silicon tubes. Definitive repair was conducted in subjects surviving for at least 48 h.ResultsOperation time was comparable between the two groups (39.6 ± 8.9 vs. 36.6 ± 7.8 min in ligation and reconnecting groups, respectively; p = 0.56). The time spent in managing each resection was also comparable (4.6 ± 1.1 vs. 3.8 ± 0.84 min; p = 0.24). Blood loss (341.2 ± 28.6 vs. 333.8 ± 34.6 ml; p = 0.48), and fluid resuscitation within the first 24 h (1676 ± 200.6 vs. 1594 ± 156.5 ml; p = 0.46) were similar. One subject in the ligation group was sacrificed at 36-h due to severe vomiting that led to aspiration. Four remaining dogs in the ligation group received definitive surgery, but two out of four had to be sacrificed at 24-h after definitive repair due to imminent death. All five dogs in the reconnecting group survived for at least a week. Radiographic examination confirmed the integrity of the GI tract in the reconnecting group. In both groups, plasma endotoxin concentration increased after damage control surgery, but the increase was much more pronounced in the ligation group. Microscopic examination of the involved segment of the intestine revealed much more severe pathology in the ligation group.ConclusionThe current study showed that the reconnecting resected intestine by using silicon tubes is feasible under emergency. Such a method could decrease short-term mortality and minimize endotoxin translocation.

show abstract

Effects of intraluminal pressure on regional blood flow in obstructed and unobstructed small intestines in the rat

Cited by 37 publications

References 22 publications

Spontaneous and Bolus-induced Motility in the Chronically Obstructed Guinea-Pig Small Intestine In vitro

Spontaneous and Bolus-induced Motility in the Chronically Obstructed Guinea-Pig Small Intestine In vitro

Biomechanical Remodeling of the Chronically Obstructed Guinea Pig Small Intestine

A novel method for multiple bowel injuries: a pilot canine experiment

Contact Info

Product

Resources

About