Establishment of an acute arterial mesenteric ischaemia model in canines with an endovascular approach

Abstract

Purpose: This study aimed to evaluate the feasibility of establishing an arterial acute mesenteric ischemia (AMI) model in canines using transcatheter autologous thrombus administration.

Materials and methods: Ten canines were divided into the experimental group (Group A, n = 5) and the sham group (Group B, n = 5). The canines in Group A received thrombus administration to the superior mesenteric artery (SMA) through a guiding catheter, while the canines in Group B received normal saline administration. Blood samples were collected and tested at baseline and 2 h after modelling. Canines in Group A underwent manual thromboaspiration after blood and intestine samples were collected. Ischaemic grades of intestinal mucosa were evaluated under light microscopes.

Results: The AMI models were successfully conducted in all canines without procedure-related vessel injury or death. At the 2-h follow-up, the high-sensitivity C-reactive protein and D-dimer in Group A were significantly higher than in Group B (5.72 ± 1.8 mg/L vs. 2.82 ± 1.5 mg/L, p = 0.024; 2.25 ± 0.8 μg/mL vs. 0.27 ± 0.10 μg/mL, p = 0.005; respectively). The mean histopathologic intestinal ischaemic grade in Group A was significantly higher than in Group B (2.4 ± 0.5 vs. 0.8 ± 0.4, p < 0.001). After a median of 2 times of thromboaspiration, 80% (4/5) of the canines achieved complete SMA revascularisation.

Conclusion: This experimental study demonstrated that establishing an arterial model in canines using endovascular approaches was feasible. The present model may play an important role in the investigation of endovascular techniques in the treatment of arterial AMI.

Keywords: acute mesenteric ischemia; animal model; autologous thrombus; endovascular; thromboaspiration.

Figure 1

AMI model in canine was created using autologous thrombus administration with a guiding catheter, and subsequent thromboaspiration was performed. (A) An autologous thrombus was prepared and cut into 30 mm length pieces (arrowhead) before the modelling. (B) Preprocedural angiography showed the overview of SMA. (C) A guiding catheter was placed at the ostium of SMA, and the thrombus was subsequently administrated. Postprocedural angiography showed the complete occlusion of the middle SMA trunk (arrowhead). (D) Follow-up angiography at 2 h after modelling showed the SMA occlusion (arrowhead) without obvious thrombus dissolution or migration. (E) Before thromboaspiration, the guiding catheter was advanced as close to the thrombus as possible. (F) After thromboaspiration, post-procedure angiography showed complete SMA revascularisation without distal embolisation. AMI, acute mesenteric ischemia; SMA, superior mesenteric artery.

Figure 2

Laboratory testing results for canines at baseline and 2-h follow-up. At baseline, there is no significant difference between Group A and Group B. At 2-h follow-up, hs-CRP and D-dimer levels in Group A were significantly higher than in Group B. Compared with the baseline results, 2-h follow-up results of hs-CRP (A), WBC (B), D-dimer (C), and lactate (D) were significantly increased in Group A. hs-CRP, high-sensitivity C-reactive protein; WBC, white blood cell count.

Figure 3

Intestine autopsy for canines in the sham group and experimental group. (A) No obvious intestinal ischemia was found in canines in the sham group after 2 h of modelling. (B) Intestine cyanosis (white arrow) and dilation (black arrow) were noted in canines in the experimental group after 2 h of modelling.

Figure 4

Findings of intestinal mucosa with H&E (×200) staining in the experimental and sham groups. (A) Denuded villi with lamina propria and dilated capillaries (pentagon) were noted in a canine in the experimental group. (B) Normal mucosal villi were presented in a canine in the sham group. H&E, haematoxylin and eosin.

Figure 5

The plot shows the distribution of histopathologic intestinal ischaemic grade in Group A and Group B. The black line indicates the mean grade, and the ischaemic grade in Group A was significantly higher than in Group B.