The Buerger's rabbit model: a closer step to unravelling thromboangiitis obliterans?

OBJECTIVE: Thromboangiitis obliterans (TAO) remains clinical challenging due to its rarity and underwhelming management outcomes. This study aimed to describe a novel TAO rabbit model that demonstrates a closer resemblance to TAO. METHODS: Thirty-six New Zealand rabbits underwent the surgical implantation of calibrated gelatin sponge particles (CGSPs) into their right femoral artery. The CGSPs were soaked in different solutions to simulate different types of thrombi: normal (NT; normal saline); inflammatory TAO thrombus (TAO; dimethylsulfoxide [DMSO]), and DMSO with methotrexate (MTX). All groups underwent clinical assessment, digital subtraction angiography (DSA) and histopathological analysis at time points day 0 (immediate), week 1 (acute), week 2 (subacute), and week 4 (chronic). RESULTS: The TAO rabbit presented with signs of ischemia of the right digit at week 4. On DSA, the TAO rabbits exhibited formation of corkscrew collaterals starting week 1. On H&E staining, gradual CGSP degradation was observed along with increased red blood cell aggregation and inflammatory cells migration in week 1. On week 2, disorganization of the tunica media layer and vascular smooth muscle cell (VSMC) proliferation was observed. In the TAO rabbit, migrated VSMCs, inflammatory cells, and extracellular matrix with collagen-like substances gradually occluded the lumen. On week 4, the arterial lumen of the TAO rabbit was filled with relatively-organized VSMC and endothelial cell clusters with less inflammatory cells. Neorevascularization was found in the MTX-treated group. CONCLUSION: The novel TAO rabbit model shows a closer resemblance to human TAO clinically, radiographically, and histopathologically. Histological analysis of the IT progression in the TAO model suggests that it is of VSMC origin.

Myofibroblasts: A New Factor Affecting the Hyperlipidemia-Induced Elastic Abnormality of Corpus Cavernosum in Rabbits Detected by 2-D Shear Wave Elastography.

OBJECTIVE: Two-dimensional shear wave elastography (2-D SWE) has been proven to detect hyperlipidemia-induced elastic abnormality in the corpus cavernosum. This study investigated cytological factors affecting the elasticity of the corpus cavernosum in rabbits with hyperlipidemia using single-cell RNA sequencing (scRNA-seq). METHODS: Male New Zealand white rabbits were randomly divided into a hyperlipidemia group (high-cholesterol diet) and a control group (standard diet). Penile 2-D SWE was performed to detect the elastic abnormality in the corpus cavernosum. ScRNA-seq was performed to observe cellular changes in the corpus cavernosum of rabbits with hyperlipidemia. Immunohistochemistry, immunofluorescence and histological examinations were conducted to verify the results of scRNA-seq. RESULTS: Two-dimensional SWE revealed that the Young's modulus of the corpus cavernosum was significantly greater in the hyperlipidemia group than that in the control group (p < 0.001). Histological findings revealed extracellular matrix accumulation within the corpus cavernosum, with stronger staining of collagen types I and Ⅲ. ScRNA-seq revealed that fibroblasts, smooth muscle cells, and endothelial cells were the major cell types in the corpus cavernosum. A novel subtype of fibroblasts (myofibroblast) was discovered in the hyperlipidemia group, which was verified by immunofluorescence staining and gene ontology analysis. Fibroblasts, smooth muscle cells and endothelial cells were three cellular sources for myofibroblasts. CONCLUSION: Myofibroblasts are activated and proliferate and secrete large amounts of collagen fibers in the corpus cavernosum during hyperlipidemia, leading to abnormal Young's modulus detected by 2-D SWE and their recognition as a new factor affecting the hyperlipidemia-induced elastic abnormality of the corpus cavernosum.

Factors affecting the shear wave elastic quantitative measurement of penile tissue in rats.

Background: As a new ultrasound technology, 2-dimensional shear wave elastography (2D-SWE) can evaluate the elastic characteristics of penile tissue. However, no studies have reported the main factors affecting the shear wave elastic quantitative measurement (SWQ) in penile tissue. Objectives: To analyze the main factors affecting the SWQ reflecting the elastic characteristics of penile tissue by 2D-SWE. Methods: Twenty healthy male Sprague-Dawley rats (5-60 weeks old) were selected for this study. We performed the 2D-SWE examination on the penis using the Aixplorer ultrasound system, with SWQ as the measurement index. We performed penile immunohistochemistry analysis with the positive area proportion (PAP) of alpha-smooth muscle actin (PAPS) and type III collagen fiber (PAPC) as the outcomes. Then, we conducted multiple linear regression analysis to explore the correlation of SWQ with PAPS and PAPC and established the regression equation. Results: The multiple linear regression analysis showed that the linear regression equation (SWQ = 10.376 - 0.05 PAPS - 0.07 PAPC) was statistically significant (F = 21.153, P < 0.001). The content of smooth muscle cells (SMCs) and collagen fibers was negatively correlated with SWQ, affecting 42.6% of the total variation in SWQ (R2 = 0.426). Conclusions: SMCs and collagen fibers are the main factors affecting the SWQ value of penile tissue and the primary tissue components determining the SWQ when using 2D-SWE to quantitatively evaluate the elastic characteristics of penile tissue.

Experimental investigation of early assessment of corpora cavernosa fibrosis with two-dimensional shear wave elastography.

This study explored the usefulness of two-dimensional shear wave elastography (2D-SWE) in the early assessment of corpora cavernosa fibrosis (CCF). New Zealand male rabbits were randomly assigned to an experimental group or a control group. Recombinant human transforming growth factor beta 1 (TGF-ß1) was injected into the dorsal penis tissue of rabbits in the experimental group. Conventional ultrasound and 2D-SWE examinations were performed before and 20 days after injection. Penile histological analysis was performed by hematoxylin-eosin staining, sirius red staining, and immunohistochemistry. Measurement of 2D-SWE examination results was performed using shear wave elastography quantitative measurement (SWQ). Histological analysis outcomes were the proportion of smooth muscle cells (SMCs), collagen fibers (CFs), collagen type I (Col I), and collagen type III (Col III), as well as the SMCs/CFs ratio, measured by sirius red staining. Other histological analysis outcomes were the positive area proportion (PAP) of TGF-ß1 (PAPT), fibronectin (PAPF), and Col III (PAPC), measured by immunohistochemistry. After recombinant human TGF-ß1 injection, SWQ was higher in the experimental group than that in the control group (P < 0.001); however, there were no differences in conventional ultrasound results. There were significant differences in histological outcomes between the two groups (all P < 0.05). These results indicated that 2D-SWE was superior for identifying early histological changes in CCF.

Combined subfascial endoscopic perforator surgery and endovenous laser treatment without impact on the great saphenous vein for management of lower-extremity varicose veins.

BACKGROUND: Conventional high ligation and stripping of the great saphenous vein (GSV) has a good curative effect but is highly traumatic with a considerable relapse rate. Subfascial endoscopic perforator surgery (SEPS) plus endovenous laser treatment (EVLT) could be applied as individual therapy. This study aimed to evaluate the feasibility of performing combined SEPS and EVLT without impacting GSV in the management of valvular insufficiency of the lower-limb venous perforators. METHODS: Placement of lower-limb venous perforator insufficiency was marked by ascending phlebography in 83 affected limbs from September 2010 to June 2011. After randomization, SEPS was performed on 41 limbs to address the insufficiency of the venous perforators under the deep fascia, in combination with EVLT to close the superficial varicose veins without impacting the GSV. The remaining 42 limbs were treated using traditional GSV phlebectomy as controls. RESULTS: Postoperatively, all varicose veins were resolved, with lightening of the pigmentation and healing of the ulcer. Within a follow-up period of 5 - 11 months, no symptoms had recurred. Compared with the control group, the operation time, the number of incisions sutured, and the in-hospital time decreased on average by 1.5 hours, 4.7, and 6.8 days, respectively (P < 0.01 in all cases). CONCLUSION: Combined SEPS and EVLT for treatment of valvular insufficiency of the lower-limb venous perforators offer the advantages of microtrauma and rapid cure.

Emergency endovascular repair of complicated Stanford type B aortic dissections within 24 hours of symptom onset in 30 cases.

OBJECTIVE: To investigate the results of emergency endovascular repair of complicated Stanford type B aortic dissections within 24 hours of symptom onset. METHODS: A retrospective analysis of the clinical data of 30 patients with complicated Stanford type B aortic dissections who underwent emergency endovascular repair between June 2007 and October 2008. Endovascular repairs were performed within 24 hours of symptom onset. Stent-grafts were deployed at the first entry tear through the femoral artery under fluoroscopic guidance. Follow-up computed tomography scans were performed at 1, 3, 6, 12, and 18 months after treatment. RESULTS: The mean patient age was 64 years (range, 43-83 years). There were 3 cases associated with rupture, 6 cases associated with refractory hypertension, 15 cases associated with persistent pain, 2 cases associated with retrograde dissection, and 4 cases associated with malperfusion. The technical success rate was 100%, and the incidence of immediate postoperative endoleaks was 13.4%. One patient died of dissection rupture within 30 days. The mean follow-up period was 12 ± 8 months. A small, persistent endoleak (<10%) occurred in 1 patient, and 1 patient died of acute liver failure 2 months after the operation. No stent dislocation, false lumen expansion, or paraplegia occurred. The false lumen was completely thrombosed in 6 patients and partially thrombosed in 19 patients. The mortality rate was 6.67%. CONCLUSIONS: Our results suggest that emergency endovascular repair of complicated Stanford type B aortic dissections within 24 hours of symptom onset is associated with good outcomes and can decrease mortality.