Routine husbandry procedures during animal toxicity studies can result in incidental pathological changes. We report on trauma-induced hepatopathy in newborn Göttingen minipigs. Sixty-four neonatal minipigs were allocated to 13- and 26-week treatment arms. There was a 4-week recovery period for both arms. The animals were divided into 2 treatment groups and a vehicle group and were dosed 3 times daily by direct oral administration using a syringe. During the feeding procedure in the first weeks, the animals had to be handled firmly. After 13 weeks, randomly distributed foci of degeneration/necrosis and focal congestion and/or hemorrhage were found in the livers of several animals from all groups. Reduced incidence and severity were evident in the recovery phase, and the lesions were absent after 26 weeks. These changes were considered as related to the manual handling of the animals. Knowledge of these findings is crucial for interpretation of studies utilizing newborn minipigs.

Objective: To compare the technical efficacy and safety between prostatic artery occlusion (PAO) with ethylene vinyl alcohol copolymer (EVOH) and prostatic artery embolization (PAE) with microspheres in a canine model. Methods: 17 adult male beagles underwent PAO (n = 7) with Onyx-18 or PAE (n = 10) with microspheres (300–500 µm). After procedures, all dogs were inspected for procedure-related complications during 1 month follow-up. MRI evaluations were performed immediately before and 1 week, 2 weeks, and 1 month after procedures to document prostate volume (PV) and the prostate ischemia size. Differences between groups were statistically analyzed. Results: Both procedures were bilaterally successful in all animals. Although the mean procedure times were comparable in both groups, the mean fluoroscopy time (23.80 vs 36.24 min, p = 0.014) and radiation dose (68.19 vs 125.26 mGy, p = 0.003) were significantly less in PAO-group. Recanalization was observed more frequently in PAE than PAO at 1 month of follow-up. The mean percentage of PV change significantly decreased at 2 weeks and 1 month in both groups (30.71% vs  37.89% at 2 week, and 56.41vs 55.56% at 1 month, after PAO and PAE respectively), without significant differences between groups at either time point. There was a significant increase in the mean prostate ischemia induced by PAO in comparison with PAE at 1 week (43.44% vs 18.91 ml, p = 0.001). No major complications were observed except one animal after PAO with transient hematuria and acute urinary retention. Conclusions: PAO with EVOH is technically feasible and with comparable efficacy and safety with PAE. Advances in knowledge: A new technical modification of the prostatic artery embolization (PAE) consisting of the use of liquid embolic agent to occlude the prostatic artery trunk and its branches has been developed in preclinical study, showing to be an effective and safe procedure which can induce a significant prostate shrinkage for the management of symptomatic BPH in patients. In addition, the findings have showed a similar therapeutic effect comparable with the conventional PAE using microspheres.

Background: Prostatic artery embolization (PAE) is an alternative treatment for symptomatic benign prostatic hyperplasia (BPH) in men. A technical modification of conventional PAE has been developed in a canine prostate model consisting of prostatic artery occlusion (PAO) using Onyx ® whose therapeutic effect is prostate shrinkage. However, the underlying mechanisms are not well clarified. The purpose was to evaluate the biological mechanisms responsible for therapeutic effects of PAO in the canine prostate.Methods: Ten adult male beagles (5.0±0.82 years) underwent PAO with Onyx-18 (n=7) and prostatic artery angiography as control (n=3). Blood samples were taken at different time points of follow-up (baseline, 1 week, 2 weeks, 1 month, 3 months and 6 months) to measure the serum canine prostate specific esterase (CPSE). MRI examinations were also performed to document the prostate volume (PV) before and after interventions at different time points of follow-up. Prostates were harvested at 2 weeks (n=2) in the PAOgroup, and the remaining ones (n=8) at 6 months for the determinations of intraprostatic testosterone and dihydrotestosterone (DHT) by ELISA, apoptosis by TUNEL assay and histopathological study. Results:The mean serum CPSE concentration started to decrease significantly from 2 weeks to 6 months after PAO along with PV compared with baseline data. In addition, a moderate but significant correlation was observed between CPSE and PV (r=0.655, P=0.000). Regarding intraprostatic androgens, testosterone was significantly higher after PAO than control (19.70 vs. 4.87 ng/mL, P=0.002), whereas DHT was lower but no significant (112.52 vs. 138.35 pg/mL, P=0.144). In histological study, PAO induced a severe hemorrhagic necrosis in the whole prostates along with inflammatory cell infiltration at early 2 weeks, and then diffuse interstitial fibrosis with atrophy of the glandular epithelium and intraprostatic cavity formation at 6 months.Apoptosis was detected in all specimens with higher apoptotic index after PAO at 2 weeks (7.35%) and at 6 months (4.38%) compared with control (2.64%), without statistically significant difference between groups.

Purpose: To analyze the complications of laparoscopy in different vascular structures using magnetic resonance imaging (MRI). MRI has become a key tool in laparoscopic surgery. During these procedures, pneumoperitoneum creation and placing the patient in the surgical position provoke different changes in the splachnic circulation. Materials and Methods:Ten pigs were included in the study. MRI studies of the abdominal area were carried out in four different situations of abdominal pressure and body position.Results: Changes in the area of the lumen of the portal vein and the abdominal aorta were analyzed in all situations. A significant reduction in the area of the abdominal aorta was observed after the pneumoperitoneum in supine and anti-Trendelemburg position. The lumen of the portal vein was significantly reduced in all analyzed situations except when placing the patient in anti-Trendelemburg without pneumoperitoneum, in which case the area was increased. Conclusion:The creation of pneumoperitoneum provokes morphological changes in the lumen of different abdominal vessels as a consequence of the increase of pressure. Furthermore, the combination of pneumoperitoneum together with the anti-Trendelemburg position results in a more significant reduction of the lumen of the portal vein and the abdominal aorta.

Background: The purpose was to assess the association between prostate infarction and prostate volume (PV) reduction after prostatic artery embolization (PAE) and define the best time point in detection of prostate infarction.Methods: Ten male beagles (3.5-6.4 years) with spontaneous benign prostatic hyperplasia (BPH) underwent PAE. Magnetic resonance image (MRI) was conducted immediately before and 1 week, 2 weeks and 1 month after PAE to document prostate infarcts and measure PV. The sum of infarct areas (SUMIA) was measured and calculated using OsiriX software. Spearman's rank correlation was used to estimate the relationship of PV reduction rate with infarction percentage and SUMIA reduction.Results: In comparison with baseline data, significant PV reduction (P<0.001) occurred at 2 weeks and continued to decrease substantially (P=0.004) from 2 weeks to 1 month after PAE. In the same fashion, significant decrease in both SUMIA and infarction percentage was observed from 1 to 2 weeks (P=0.002), and subsequently to 1 month (P=0.039 and P=0.016, respectively). Spearman's rank correlation test demonstrated infarction percentage at 1 week had a stronger correlation (r=0.880, P=0.001) with PV reduction rate at 1 month than infarction percentage at 2 weeks (r=0.733, P=0.016). PV reduction rate had a significant correlation with decrease in SUMIA (r=0.854, P=0.002) at 1 month after PAE.Conclusions: One week after PAE is an ideal time point to evaluate prostate infarction. Prostate infarction percentage at 1 week is a good predictor for prostate shrinkage at 1 month after PAE.