Different doses of enoxaparin in the prevention of postoperative abdominal adhesions. Experimental study

Background

Postoperative abdominal adhesions (PAAs) are present in more than 90% of patients undergoing abdominal surgery. They are a cause of chronic pain, hospitalizations, multiple surgeries, and infertility in women of reproductive age. The participation of three processes have been recognized: coagulation, fibrinolysis, and inflammation. The usefulness of subcutaneous enoxaparin in their prevention has been established. The objective is to establish the safest and most efficient dose for PAA prevention by testing five different doses of subcutaneous enoxaparin (0.25, 0.5, 1, 1.5, and 2 mg/kg/day) given in one dose/day for seven days.

Material and methods

Fifty Sprague-Dawley rats were studied, 10 in each group. Adhesions were induced through controlled rubbing of the cecum and suturing of an incision in the terminal ileum. Two independent observers recorded the degree of adhesion formation at 14 days and histologically studied the adhesions.

Statistical analysis

ANOVA compared group averages. The nonparametric Kruskal-Wallis test was used to identify group differences.

Results

The 0.5 mg/kg/day group had greater formation of adhesions (p < 0.001). There was no significant difference between the 1.5 and 2 mg/kg/day groups, though the latter group had an incidence of 27.2% of bleeding in the abdominal cavity. The degree of adhesions in the histological sections coincided with the macroscopic findings. The interobserver agreement was kappa = 0.88 (very good).

Conclusion

The safe and effective dose of subcutaneous enoxaparin to prevent PAA formation was 0.5–1.5 mg/kg/day for seven days.

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Postoperative abdominal adhesions are the cause of clinical alterations that require significant economic expenses.

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Activation of the coagulation cascade is a component in the formation of adhesions.

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Enoxaparin reduces the appearance of postoperative abdominal adhesions.

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The prophylactic dose of enoxaparin is sufficient to prevent adhesions.

Postoperative abdominal adhesions: pathogenesis and current preventive techniques

Post-operative abdominal adhesions (PAA) are a condition that occurs in more than 90% of patients undergoing abdomen surgery; they can cause chronic abdominal pain, female infertility and repeated bowel obstruction, requiring repetitive surgical interventions causing morbidity and mortality, as well as high costs. The formation of the PAA is due to an imbalance between the fibrinogenesis and fibrinolysis in favor of the first, associated with tissue hypoxia secondary to aggression of the peritoneum, also due to the own inflammatory response and the increase in the population of adhesion fibroblasts which inhibit the degradation of the extracellular matrix and facilitate mature collagen and supporting connective tissue. The prevention of PAA will decrease secondary complications, as well as hospitalizations, surgeries and consequently, cost containment. The PAA pathophysiologic process allows establishing research strategies in order to prevent them.

17β Estradiol Modulates Perfusion Pressure and Expression of 5-LOX and CYP450 4A in the Isolated Kidney of Metabolic Syndrome Female Rats

Prevalence of metabolic syndrome and progression of nephropathy depend on sex. We examined a protective effect of estradiol against nephropathy in metabolic syndrome through the modulation of the arachidonic acid metabolism by activating the 5-lipoxygenase and cytochrome p450 4A pathways. 28 female Wistar rats were divided into four groups of seven animals each: control, intact metabolic syndrome, ovariectomized metabolic syndrome, and metabolic syndrome ovariectomized plus estradiol. Blood pressure, body weight, body fat, triglycerides, insulin, HOMA-index, albuminuria, and TNF-α were increased in ovariectomized metabolic syndrome rats (p < 0.001). The perfusion pressure in isolated kidneys of ovariectomized metabolic syndrome rats in presence of 4 μg of arachidonic acid was increased. The inhibitors of the arachidonic acid metabolism Baicalein, Miconazole, and Indomethacin in these rats decreased the perfusion pressure by 57.62%, 99.83%, and 108.5%, respectively and they decreased creatinine clearance and the arachidonic acid percentage. Phospholipase A2 expression in the kidney of ovariectomized metabolic syndrome rats was not modified. 5-lipoxygenase was increased in metabolic syndrome ovariectomized rats while cytochrome p450 4A was decreased. In conclusion, the loss of estradiol increases renal damage while the treatment with estradiol benefits renal function by modulating arachidonic acid metabolism through the 5-lipoxygenase and cytochrome p450 4A pathways.

Multiple extrauterine pregnancy with early and near full-term mummified fetuses in a New Zealand white rabbit (Oryctolagus cuniculus)

Extrauterine pregnancy (EP) is infrequent in mammalian species and occurs when fertilized ova implant and develop outside the uterus. A common outcome is abdominal pregnancy resulting in mummified fetuses (lithopedia). Here we describe an unusual case of abdominal pregnancy with early and near full-term lithopedia. Macroscopic findings supported the diagnosis of lithopedia with distinct age differences and facilitated further characterization of primary ectopia and risk factors leading to this occurrence.

Characterization of spontaneous subclavian steal phenomenon in a female rhesus macaque (Macaca mulatta)

In subclavian steal phenomenon (SSP), the subclavian artery develops a stenoocclusive disease proximal to the origin of the vertebral artery, leading to pronounced hemodynamic changes such as arterial flow reversal. Although SSP is a common echographic finding in humans, the phenomenon occurs only rarely in animals; consequently its physiologic features have not been reported previously. Here we describe the clinical and morphologic features of a spontaneous left SSP that was an incidental finding in an 18-y-old female rhesus macaque (Macaca mulatta). Our findings were documented through high-quality imaging studies obtained by using a computerized 3D tomography apparatus and clinical assessment of systolic and diastolic blood pressures.

Radiographic incidence of spinal osteopathologies in captive rhesus monkeys (Macaca mulatta)

Degenerative spinal disease is a leading cause of chronic disability both in humans and animals. Although widely seen as a normal occurrence of aging, degenerative spinal disease can be caused by various genetic, iatrogenic, inflammatory, and congenital factors. The objective of this study was to characterize the degenerative spine-related diseases and the age at onset in a random subpopulation of 20 captive rhesus monkeys (Macaca mulatta; male, 13; female, 7; age: range, 4 to 27 y; median, 18.5 y). Spinal radiographic evaluation (left lateral, right lateral, and ventrodorsal views) of the spinal column (C1 to S1) was performed, and spinal degenerative disease was scored. The incidence of osteopathology was higher in the 14- to 18-y-old group, but incidence did not differ according to sex. In the studied population, degenerative changes were present in monkeys as young as 9 y of age.