Ultrasound-guided nitinol stent implantation to treat early restenosis of arteriovenous fistula: A 69-case study with 1-year outcome.

BACKGROUND: To investigate the feasibility, methods and effects of interventional ultrasound in nitinol stent implantation to treat early restenosis after percutaneous transluminal angioplasty (PTA) in autogenous arteriovenous fistula (AVF). METHODS: From April 2018 to December 2021, 69 patients with early restenosis of AVF received ultrasound-guided nitinol stent implantation (UNSI) and were followed-up. Imaging features of the stent and procedure by ultrasound were observed. The technical success rate, clinical success rate and incidence of complications were recorded and counted. Target lesion primary patency (TLPP), access circuit primary patency (ACPP) and access circuit secondary patency (ACSP) were estimated. RESULTS: Ultrasonography can show the structure of the stent and guide the stenting process clearly. Both the technical and clinical success rates were 100%. Thirty-one patients had in-stent restenosis (ISR), which was treated by plain balloon (PB) PTA or drug coated balloon (DCB) PTA. The TLPP at 3, 6, 12 and 24 months were 100.0%, 94.2%, 63.4% and 39.6%, respectively. The ACPP at 3, 6, 12 and 24 months were 98.6%, 91.6%, 60.2% and 35.2%, respectively. The ACSP at 3, 6, 12 and 24 months were 98.6%, 98.6%, 95.6% and 93.8%, respectively. The TLPP of ISR after DCB PTA at 3, 6 and 12 months were 100.0%, 100.0% and 93.6%, respectively. CONCLUSIONS: This pilot study indicates ultrasonography can accurately guide nitinol stent implantation in AVF and this technique is a feasible and minimally invasive treatment for early restenosis after PTA with good short- and medium-term patency. DCB PTA may be used to deal with the ISR and is a way to prolong the patency of nitinol stent.

Mycophenolate mofetil-associated collagenous ileitis in a kidney transplant recipient: A case report.

We report a case of mycophenolate mofetil-induced collagenous ileitis in a kidney transplant patient. A 38-year-old Chinese man who had received a kidney transplant 3 years earlier was admitted to our department for severe diarrhea and rapid weight loss. Infection studies were negative, and tumors were ruled out, so drug-induced factors were suspected. He had been taking mycophenolate mofetil for immunosuppression, which was then suspended, and he had a rapid resolution of diarrhea. Pathological findings of gastrointestinal endoscopy biopsy showed the presence of thickened collagen bands in the subepithelium of the terminal ileum. This is the first report of collagenous ileitis caused by mycophenolate mofetil in a patient with a kidney transplantation, adding another reversible cause to this rare condition. It is important for clinicians to recognize and treat it promptly.

Ultrasound-Guided Cradle-Like Infiltrative Anesthesia for Percutaneous Transluminal Angioplasty of Stenotic Autogenous Arteriovenous Hemodialysis Access.

BACKGROUND: Percutaneous transluminal angioplasty (PTA) is an effective treatment for autogenous arteriovenous hemodialysis access (AAVA) stenosis; however, it causes pain in most cases. Therefore, safe and effective anesthesia for PTA is required. METHODS: We introduced a method of ultrasound-guided cradle-like infiltration anesthesia (UCIA) to administer analgesia during PTA. Using ultrasound guidance, 1% lidocaine was injected into the bilateral and inferior perivascular spaces of the stenosis to form a cradle-like region. In this study, 100 consecutive patients were divided into two groups, and the analgesic effect of UCIA was evaluated using a numerical rating scale with non-ultrasound-guided infiltration anesthesia as a control. Meanwhile, we compared the effect of PTA between the two groups with the postoperative internal diameter of the stenosis. RESULTS: The numerical rating scale score was 4.6 ± 1.9 and 2.0 ± 1.6 (P < 0.001) in UCIA group and non-ultrasound-guided infiltration anesthesia group, respectively. The postoperative internal diameter of stenosis was 3.9 ± 0.6 mm and 4.1 ± 0.7 mm (P = 0.113); the postoperative AAVA flow volume was 627 ± 176 mL/min and 644 ± 145 mL/min (P = 0.600). CONCLUSIONS: This study preliminarily showed that UCIA is effective and safe for the analgesia of AAVA PTA.

Ultrasound-guided nitinol stent implantation in treatment of early recurrent stenosis of arteriovenous fistula.

To investigate the feasibility, methods and efficacy of ultrasound-guided nitinol stent implantation for the treatment of early recurrent stenosis of arteriovenous fistula (AVF). Thirty patients with early recurrent stenosis after percutaneous transluminal angioplasty (PTA) who received ultrasound-guided nitinol stent implantation in Sir Run Run Shaw Hospital of Zhejiang University from April 2018 to July 2020 were followed up. The imaging features of the procedure and the interventional devices were observed under ultrasonography. The technical success rate and the clinical success rate as well as the incidence of complication were assessed. The post-interventional primary patency rates of access circuit, primary patency rates of target lesion and secondary patency rates were estimated. Ultrasonography was able to demonstrate the operation process and the interventional devices clearly. The technical and clinical success rates were both 100.0%. Eight patients had in-stent restenosis, which were treated by PTA. The post-interventional primary patency rates of the access circuit after 3, 6, 9 and were 91.3%, 86.2%, 86.2% and 64.2%, respectively; the post-interventional primary patency rates of target lesion were 100.0%, 100.0%, 86.4% and 69.3%, respectively; the post-interventional secondary patency rates were 100.0%, 100.0%, 100.0% and 94.4%, respectively. Compared with previous PTA in these cases, stent implantation had a higher post-interventional primary patency rates of target lesion and a lower cost-effectiveness (both <0.05). No other complications such as vascular rupture, pseudohemangioma, stent infection, stent displacement and stent exposure were observed during the follow-up. Ultrasonography can accurately guide the nitinol stent implantation in AVF, and the technique is feasible in treatment for the early recurrent stenosis after PTA with good short- and medium-term efficacy.

Lack of microRNA-155 ameliorates renal fibrosis by targeting PDE3A/TGF-ß1/Smad signaling in mice with obstructive nephropathy.

Although microRNA-155 (miR-155) is implicated in the pathogenesis of several fibrotic diseases, information regarding its functional role in renal fibrosis is limited. The current study aims to investigate the effects of miR-155 on renal fibrosis in unilateral ureteral occlusion (UUO) mice. MiR-155 level was significantly increased in renal tissues of UUO mice and TGF-ß1-treated HK2 cells. Masson's trichrome staining showed that delivery of adeno-associated virus encoding miR-155 inhibitor led to a decrease in renal fibrosis induced by UUO. The increased expression of plasminogen activator inhibitor type 1, collagen III and collagen IV was also inhibited after miR-155 inhibition. In addition, miR-155 knockdown also prevented TGF-ß1-induced epithelial-mesenchymal transition, concomitantly with a restoration of E-cadherin expression and a decrease of vimentin expression. Computational analysis revealed that miR-155 directly targets at 3'UTR of PDE3A. Overexpression of miR-155 suppressed the luciferase activity and protein expression of PDE3A, whereas inhibition of miR-155 increased PDE3A luciferase activity and expression. Furthermore, miR-155 inhibited TGF-ß1-induced the increase of TGF-ß1 expression and Smad-2/3 phosphorylation in HK2 cells. In contrast, knockdown of PDE3A reversed the effect of miR-155 inhibition on TGF-ß1 expression. This study demonstrates that knockdown of miR-155 attenuates renal fibrosis via inhibiting TGF-ß1/Smad signaling activation by targeting the upstream molecule PDE3A. This study suggests that miR-155 inhibition may be a novel therapeutic approach for preventing fibrotic kidney diseases.

An elevated level of BNP in plasma is related to the development of good collateral circulation in coronary artery disease.

OBJECTIVE: B-type natriuretic peptide (BNP) was recently demonstrated to be a potential stimulator of angiogenesis and arteriogenesis. The correlation between BNP level and collateral formation in patients with coronary artery disease (CAD) has not been reported. METHODS AND RESULTS: The study included 311 consecutive patients who underwent coronary angiography were divided into three groups according to coronary angiography and collateral formation: normal group (100 patients with normal coronary angiographic findings); poor collateral group (116 patients with at least one coronary stenosis of ≥75% without visible collateral circulation); and good collateral group (95 patients with at least one coronary stenosis of ≥75% with well-developed collateral circulation). Collateral score was analyzed using the Cohen-Rentrop classification. Plasma BNP levels were 45.77 ± 4.66 pg/ml, 116.40 ± 28.15 pg/ml, and 254.20 ± 42.85 pg/ml for patients in normal, poor collateral, and good collateral groups, respectively. Plasma BNP levels in the latter were significantly higher than in the normal group (p < 0.01) and poor collateral group (p < 0.05). There were no significant differences between the good collateral group and poor collateral group when compared with left ventricular ejection fraction (LVEF), left ventricular dimensions at end diastole (LVEDd), age, severity of angiographic disease, and other cardiovascular risk factors. After adjustment in the multiple ordinal logistic regression model, plasma BNP levels showed a strong independent association with collateral Cohen-Rentrop score (χ(2 )= 5.636, OR = 1.002, 95% CI 1.000-1.004, p = 0.018). CONCLUSIONS: An elevated level of BNP in plasma is independently associated with collateral development; patients with good collaterals tend to have a higher BNP level.

Plasma hyaluronan and collateral development in patients with coronary artery disease.

OBJECTIVE: In-vivo studies have shown that hyaluronan (HA) can promote angiogenesis and arteriogenesis, which results in accelerated collateral development. This study is aimed at investigating the association between plasma HA levels and the extent of coronary collaterals, in patients with coronary artery disease. METHODS: A total of 253 consecutive patients, who underwent coronary angiography, were divided into three groups according to coronary angiograms: normal group, 81 patients with normal coronary angiographic findings; poor collateral group, 98 patients with at least one coronary stenosis of at least 75%, but without visible collateral circulation; good collateral group, 74 patients with at least one coronary stenosis of at least 75% with well-developed collateral circulation. Plasma HA levels were measured by radioimmunoassay. The correlation between HA levels and the extent of coronary collaterals according to the Cohen-Rentrop classification was calculated by cumulative logits models. RESULTS: Plasma HA levels were 43.71+/-2.91, 61.77+/-4.10, and 131.97+/-11.76 ng/ml, for patients in the normal, poor collateral, and good collateral groups, respectively. The good collateral group had significantly higher plasma HA levels than the poor collateral (P<0.001) and normal group (P<0.001), whereas there was no significant difference between the normal and poor collateral group. HA levels elevated with increasing Rentrop score, and the cumulative logits model showed a strong graded association between plasma HA levels and the collateral Cohen-Rentrop score (odds ratio=1.021, chi2=17.811, 95% confidence interval: 1.011-1.031, P=0.000). CONCLUSION: This study suggests that elevated plasma HA levels are associated with a significant enhancement in coronary collateralization. HA may serve as a novel potential biomarker for collateral formation in patients with coronary artery disease.

Th1 polarization and low-T3 syndrome are correlated with hyperleptinemia in hemodialysis patients.

BACKGROUND: Patients undergoing chronic hemodialysis (HD) have an impaired immune response with a dysregulated Th1/Th2 cytokine network and altered the levels of thyroid hormone (TH) in euthyroid sick syndrome. Leptin, an adipocyte-secreted hormone, is considered to be a proinflammatory adipocytokine, with multiple effects on several tissues acting on the intermediate and energy metabolism. The aims of the present study were to assess the changes in serum levels of leptin and their correlation with Th1/Th2 cytokine and TH production in HD patients. METHODS: Fifty-three uremic patients with hemodialysis were evaluated; 30 healthy volunteers served as controls. Baseline serum concentrations of interleukin-2 (IL-2), sIL-2R, interferon-gamma (IFN-gamma), IL-4 and IL-10 were analyzed using ELISA. Serum levels of leptin, total triiodothyronine (TT3), free triiodothyronine (FT3), total thyroxine (TT4), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were determined by radioimmunoassay (RIA). Other metabolic variables were measured in all patients and control subjects. Multiple correlation analysis was performed among variables. RESULTS: Mean serum leptin concentration was significantly higher in HD patients than that in controls (p<0.01), especially in women (p<0.001). While the fasting serum levels of sIL-2R and Th1-type cytokines including IL-2 and IFN-gamma were significantly higher in HD patients compared with controls, Th2-type cytokine, including IL-4 and IL-10, levels did not differ between patients and controls. The serum TT3 and FT3 levels were lower in patients than controls, but TT4, FT4 and TSH were no different. Serum leptin levels in HD patients were significantly positively correlated with IL-2, IFN-gamma, sIL-2R and TSH; and negatively correlated with IL-4, IL-10, TT3 and FT3. Serum IL-2 levels correlated positively with serum IL-4, sIL-2R, TT3 and FT3. A negative correlation was observed between serum IFN-gamma and IL-4 levels in the patients. CONCLUSIONS: These data suggest that hyperleptinemia in HD patients correlated with cytokine dysregulation with a high level of Th1-type cytokines, and euthyroid sick syndrome with low T3 levels which might be involved in Th1 polarization and low-T3 syndrome in dialysis patients.