Yonghua Bi

Initial Imaging Analysis of Budd-Chiari Syndrome in Henan Province of China: Most Cases Have Combined Inferior Vena Cava and Hepatic Veins Involvement

Aim To evaluate the type of venous involvement in Chinese Budd-Chiari syndrome (BCS) patients and the relative diagnostic accuracy of the different imaging modalities. Methods Using digital subtraction angiography (DSA) as a reference standard, color Doppler ultrasound (CDUS), computed tomography angiography (CTA), and magnetic resonance angiography (MRA) were performed on 338 patients with BCS. We analyzed the course of the main and any accessory hepatic veins (HVs) and the inferior vena cava (IVC) to assess the etiology of obstructed segments and diagnostic accuracy of CDUS, CTA and MRA. Results Among the 338 cases, there were 8 cases (2.4%) of isolated IVC membranous obstruction, 45 cases (13.3%) of isolated HV occlusion, and 285 cases (84.3%) with both IVC membranous obstruction and HV occlusion. Comparing with DSA, CDUS, CTA had a diagnostic accuracy of 89.3% and 80.2% in detecting BCS, and 83.4% of cases correctly correlated by MRA. Conclusion In Henan Province, most patients with BCS have complex lesions combining IVC and HV involvement. The combination of CDUS and CTA or MRI is useful for diagnosis of BCS and guiding therapy.

Development of a Novel Rabbit Model of Abdominal Aortic Aneurysm via a Combination of Periaortic Calcium Chloride and Elastase Incubation

Background The purpose of this study was to introduce a novel, simple and effective technique for creating a reliable rabbit model of abdominal aortic aneurysm (AAA) via a combination of periaortic calcium chloride (CaCl2) and elastase incubation. Methods Forty-eight New Zealand white rabbits were divided into four groups. The AAA model was developed via a 20-minute periaortic incubation of CaCl2 (0.5 mol/L) and elastase (1 Unit/µL) in a 1.5-cm aortic segment (Group CE). A single incubation of CaCl2 (Group C) or elastase (Group E) and a sham operation group (Sham Group) were used for the controls. Diameter was measured by serial digital subtraction angiography imaging on days 5, 15 and 30. Animals were sacrificed on day 5 and day 30 for histopathological and immunohistochemical studies. Results All animals in Group CE developed aneurysm, with an average dilation ratio of 65.3%±8.9% on day 5, 86.5%±28.7% on day 15 and 203.6%±39.1% on day 30. No aneurysm was found in Group C, and only one aneurysm was seen on day 5 in Group E. Group CE exhibited less intima-media thickness, endothelial recovery, elastin and smooth muscle cell (SMC) content, but stronger expression of matrix metalloproteinase-2, matrix metalloproteinase-9 and RAM11 compared to the controls. Conclusions The novel rabbit model of AAA created by using a combination of periaortic CaCl2 and elastase incubation is simple and effective to perform and is valuable for elucidating AAA mechanisms and therapeutic interventions in experimental studies.

Different long-term outcomes of abdominal aortic aneurysm and intracranial aneurysm models: hemodynamic change may also play an essential role in the initiation and progression of abdominal aortic aneurysm in rabbits.

Self-healing phenomenon was found in the periarterial elastase-induced abdominal aortic aneurysm (AAA) in rabbit. This kind of aneurysm model does not progress and heals spontaneously in the long term, which is quite different from the performance of AAA disease in human. In order to better mimic human AAA and overcome this shortcoming of traditional AAA model in rabbit, we studied the pathogenesis of cerebral aneurysm (CA) model in small animal, which shows an excellent long-term patency and progressive enlargement. We found that hemodynamic conditions, such as turbulence flow, high blood flow, and shear stress, play an important role in the formation and progression of CA. So, we hypothesize that hemodynamic change may also play an essential role in the initiation and progression of rabbit AAA, and self-healing will be overcome if hemodynamic condition changes by coarctation of infra-renal aorta after elastase incubation.

Transauricular intra-arterial and intravenous digital subtraction angiography for abdominal aortic aneurysm imaging in a rabbit model

Aim The aim of this study was to evaluate transauricular digital subtraction angiography (DSA) as an alternative to conventional intra-arterial DSA for rabbit abdominal aortic aneurysm (AAA). Materials and methods AAA models were created in 8 New Zealand white rabbits by sewing vein patch. The diameters of aortic arteries were measured by DSA via ear vein and ear central artery. The common carotid artery (CCA) was exposed and cannulated for DSA as conventional angiography. Diameter size was measured and compared. Results Aortic diameters, tested by DSA via ear vein, ear central artery and CCA were 7.9 ± 1.2 mm, 7.8 ± 1.0 mm and 7.9 ± 1.1 mm respectively, with no significant differences. Angiography via CCA as standard procedure, correlation in aneurysm neck diameter was r = 0.93 for IVDSA and r = 0.96 for angiography via central artery (P < 0.01); Correlation in AAA diameter was r = 0.99 for IVDSA and r = 0.99 for angiography via central artery (P < 0.0001). Conclusions Transauricular DSA shows good correlation to conventional DSA, can be used repeatedly with less invasiveness, and suitable for rabbit AAA follow-up study.

Combination of Periaortic Elastase Incubation and Cholesterol-Rich Diet: A Novel Model of Atherosclerosis in Rabbit Abdominal Aorta

Atherosclerosis, the leading cause of most cardiovascular disease, is a progressive multifaceted inflammatory disease characterized by extracellular matrix degradation and extensive remodeling of artery wall. However, its mechanism has not been completely understood, and animal models are useful to study its pathogenetic process. An analysis of literature on the nature of atherosclerosis indicates that focal accumulation of smooth muscle cells (SMCs) into the intima by plasma factors is fundamental to the entire process of plaque growth. In our previous study, vascular SMCs proliferation was obvious in elastase-induced aorta by day 15, which led to intimal hyperplasia and regression of rabbit aneurysm. Model induced by combination of balloon injury and an atherogenic diet in rabbits is the conventional, but most largely used experimental model of atherosclerosis. Since proliferation and accumulation of intimal SMCs are found in elastase-induced aorta, and hypercholesterolemia is usually induced by cholesterol-rich diets in rabbits, a novel atherosclerosis model may be induced by combination periaortic elastase incubation and cholesterol-rich diet.

Detection and characterization of Budd-Chiari syndrome with inferior vena cava obstruction: Comparison of fixed and flexible delayed scan time of computed tomography venography

PURPOSE To compare the results of computed tomography venography (CTV) with a fixed and a flexible delayed scan time for Budd-Chiari syndrome (BCS) with inferior vena cava (IVC) obstruction. MATERIAL AND METHODS A total of 209 consecutive BCS patients with IVC obstruction underwent either a CTV with a fixed delayed scan time of 180s (n=87) or a flexible delayed scan time for good image quality according to IVC blood flow in color Doppler ultrasonography (n=122). The IVC blood flow velocity was measured using a color Doppler ultrasound prior to CT scan. Image quality was classified as either good, moderate, or poor. Image quality, surrounding structures and the morphology of the IVC obstruction were compared between the two groups using a χ2-test or paired or unpaired t-tests as appropriate. Inter-observer agreement was assessed using Kappa statistics. RESULTS There was no significant difference in IVC blood flow velocity between the two groups. Overall image quality, surrounding structures and IVC obstruction morphology delineation on the flexible delayed scan time of CTV images were rated better relative to those obtained by fixed delayed scan time of CTV images (p<0.001). Evaluation of CTV data sets was significantly facilitated with flexible delayed scan time of CTV. There were no significant differences in Kappa statistics between Group A and Group B. CONCLUSION The flexible delayed scan time of CTV was associated with better detection and more reliable characterization of BCS with IVC obstruction compared to a fixed delayed scan time.

Long-term Outcome of Recoverable stents for Budd-Chiari syndrome Complicated with Inferior Vena Cava Thrombosis

This study aimed to present long-term results of a 12-year patient follow-up of recoverable stents for BCS complicated by inferior vena cava (IVC) thrombosis. Forty consecutive patients with BCS complicated by IVC thrombosis were treated with recoverable stents. The median duration of symptoms was 24 months. Recoverable stents was placed after predilation of the obstructed IVC, and then agitation thrombolysis or catheter-directed thrombolysis of IVC was performed. The recoverable stents was removed eventually after thrombus disappeared. Clinical patency was defined as absence or improvement of symptoms. Patients were subsequently followed-up by color Doppler ultrasound. Recoverable stents placement, balloon angioplasty and thrombolysis were technically successful in all patients. Stents were successfully removed in 92.1% of patients. A few serious related complications including one acute pulmonary thromboembolism, one stent migration, and one failure retrieval stents occurred. The median follow-up was 43.7 months. The long-term results were satisfactory except 2 patients who presented with a restenosis or re-obstruction and underwent additional therapy. There were 5 deaths owing to pulmonary embolism or underlying malignant disease 0.4–101.8 months after the procedures, including one procedure-related death. In conclusion, Recoverable stents treatment is safe and effective for BCS complicated by IVC thrombosis, with a good long-term outcome.

Hemodynamics and pathology of an enlarging abdominal aortic aneurysm model in rabbits

Hemodynamics may play an essential role in the initiation and progression of abdominal aortic aneurysm (AAA). We aimed to study the mechanism of self-healing process by the changes of hemodynamics and pathology in an enlarging AAA in rabbits. Seventy-two rabbits were randomly divided into three groups. Rabbits underwent extrinsic coarctation and received a 10-minute elastase incubation in Group A and Group B. Absorbable suture used in Group A was terminated by balloon dilation at week 4. Diameter was measured after 1, 3, 5, and 15 weeks, computational fluid dynamics analysis was performed at week 3 and week 15. Rabbits were sacrificed after 1, 5, and 15 weeks for pathological and quantitative studies. The higher velocity magnitude, intensified bulk flow and obvious vortex formation were observed in Group A at week 3 instead of week 15. Both low wall shear stress and high relative residence time increased in Group B, however, high oscillatory shear index had relatively less increase compared with Group A. Aortic diameter reached a plateau at 5 weeks in Group A, which was significantly lower than in week 15 in Group B. Intimal hyperplasia, intima-media thickness increased significantly in Group A at week 5, significantly higher than in week 15 in Group B. Marked destruction of elastin fibers and smooth muscle cells occurred at week 1, and increased significantly at week 15 in Group A. Aneurysm exhibited strong expression of matrix metalloproteinase 9 and mouse anti-rabbit macrophage 11 at week 1, and showed a tendency to decrease. Matrix metalloproteinase 2 expression decreased significantly in Group B at week 15 compared with week 5 and Group A. In conclusion, the self-healing of rabbit AAA may attributed to the regeneration of smooth muscle cells. The turbulence flow caused by coarctation is associated with continuous growth of rabbit AAA and prevents the self-healing phenomenon.

Long-term Outcomes of Endoluminal Sharp Recanalization of Occluded Inferior Vena Cava in Budd-Chiari Syndrome

PURPOSE To report the long-term results of endoluminal sharp recanalization of occluded inferior vena cava (IVC) in patients with the Budd-Chiari syndrome (BCS). PATIENTS AND METHODS Seventy-two consecutive patients with BCS and IVC occlusion underwent endoluminal recanalization of the IVC occlusion during a 6-year period. BCS with occlusive IVC was detected by reviewing patient history and color Doppler ultrasonography. Data on technical success, morbidity, mortality, complications, and color Doppler sonographic outcome were collected and analyzed. RESULTS Seventy-seven recanalizations were performed in 72 patients. Technical success (patent IVC with good blood flow) was achieved in 70 (97.4%) patients. No perioperative death was observed. Six complications were found during recanalization, and 10 complications were found for total interventional procedures. The complication rates were 7.8% and 7.3% for recanalization and total procedure, respectively. Bleeding of access veins was the most common complication, and 2 patients showed slight rupture of IVC. The postoperative IVC diameter and blood speed of IVC increased significantly. Fifty-seven patients (79.2%) were clinical cured, and 2 patients (2.8%) showed no improvement. The 1-year, 3-year, and 5-year primary patency rates were 92.5%, 86.8%, and 77.3%, respectively. The second patency rates were 100.0%, 97.8%, and 91.8% for 1, 3, and 5 years, respectively. There were 2 deaths during follow-up. CONCLUSION Endoluminal sharp recanalization of occluded IVC in patients with BCS is safe and effective with good long-term outcomes.

Percutaneous Transhepatic Hepatic Vein Angioplasty in Budd–Chiari Syndrome After Transvenous Failure

PURPOSE To evaluate the safety and efficacy of percutaneous transhepatic route creation for hepatic vein (HV) angioplasty in Budd-Chiari syndrome (BCS). PATIENTS AND METHODS Between April 2012 and August 2016, a total of 19 BCS patients underwent percutaneous transhepatic route creation for HV angioplasty after transvenous catheterization failure in this study. Color Doppler ultrasonography was required in all patients after admission and during follow-up. Data were retrospectively collected, and follow-up observations were performed. RESULTS Technical and clinical success was achieved in 18 patients. Except for 1 failure of route creation, 19 routes were successfully created in 18 patients, with a technology success rate of 95.0%. Twenty-two balloon angioplasties were performed in 18 patients, with a mean balloon diameter of 13.6 ± 0.5 mm. Blood pressure and length of occlusive HV decreased significantly, and blood flow velocity and diameter of HV increased significantly after procedure. Abdominal distension/pain and ascites decreased significantly after procedure. One procedure-related death occurred, who died of gastrointestinal bleeding 6 days later. Except for the failure case, the rest of 18 patients were successfully followed up. The remaining 18 patients survived during follow-up, with a 5-year survival rate of 94.9%. One patient had a restenosis of HV after 47 days, and had undergone successful dilation. The 5-year primary and second patency rates were 94.1% and 100%, respectively. CONCLUSION Percutaneous transhepatic route creation is safe and effective for HV angioplasty, and can be used to treat BCS patients after transvenous catheterization failure.