Risk factors for hypotension in patients with hemodialysis-associated superior vena cava syndrome.

OBJECTIVE: We analyzed the risk factors for hypotension in patients with hemodialysis-associated superior vena cava syndrome (SVCS) and effectiveness of endovascular intervention in hypotension related to SVCS. METHODS: This was a retrospective cohort study. A total of 194 maintenance hemodialysis patients diagnosed with SVCS who were admitted to the Department of Nephrology, West China Hospital of Sichuan University from January 2019 to December 2021 were selected and divided into a hypotension group and a nonhypotension group. Demographic and clinical data were compared. Hypotension simply refers to blood pressure levels of <90/60 mm Hg on a nondialysis day. All patients received endovascular intervention. RESULTS: Hypotension was found in 85 of the 194 patients. The following factors were significantly different between the hypotension and nonhypotension groups: body mass index, history of hypertension, tunneled-cuffed catheter as the means of dialysis access, azygos ectasis, SVC stenosis of >70% or occlusion, occlusion at the cavitary junction, serum calcium, diastolic left ventricular (LV) posterior wall thickness, LV end-diastolic volume, stroke output, and LV ejection fraction. Multivariate logistic regression analysis showed that hypertension history (OR, 0.314; P = .027), tunneled-cuffed catheter as vascular access (OR, 3.997; P < .001), SVC stenosis of >70% or occlusion (OR, 5.243; P < .001), LV posterior wall thickness (OR, 0.772; P = .044), and serum calcium (OR, 0.146; P = .005) were independent risk factors for hypotension. The mean values of systolic and diastolic blood pressure after intravascular treatment were significantly elevated from those before intervention (P < .001). The primary patency rates of SVC were 66.8%, 58.7%, and 50.0% at 3, 6, and 12 months after the procedure. CONCLUSIONS: The incidence of hypotension in patients with hemodialysis-associated SVCS is high. The identification of risk factors of hemodialysis-related hypotension provides insight into potential treatment strategies. Endovascular treatment is expected to improve hypotension related to SVCS in hemodialysis patients.

Percutaneous superior vena cava puncture for hemodialysis catheter placement.

OBJECTIVE: Central venous occlusion (CVO) refractory to endovascular angioplasty is a critical challenge that threatens hemodialysis vascular access. In the present study, we evaluated the efficacy and safety of tunneled, cuffed central venous catheter (tCVC) placement via percutaneous superior vena cava (SVC) puncture in patients with refractory CVO. METHODS: Patients requiring maintenance hemodialysis with refractory CVO who had undergone percutaneous SVC puncture and tCVC insertion at a university-affiliated hospital from January 2016 to June 2020 were included. The patients were followed up until May 2021. The demographic information, complications, and catheter patency were analyzed. RESULTS: A total of 205 patients (105 women [51.2%]; mean age, 61 ± 15 years) were included. The SVC puncture and tCVC insertion were successfully performed in 194 patients, for a technical success rate of 94.6%. One patient had experienced a pleura injury and hemothorax and had required urgent thoracotomy. A total of 37 patients had presented with mild chest pain and were prescribed oral nonsteroidal anti-inflammatory drugs. During follow-up of the 194 patients with a successful procedure, catheter dysfunction due to thrombosis had occurred in 66 patients, catheter malposition had occurred in 5 patients, and catheter-related blood stream infection had developed in 6 patients. The 3-year primary patency rate was 64.2%, and the 3-year secondary patency rate was 76.3%. CONCLUSIONS: A tCVC placed through a percutaneous SVC puncture had a satisfactory technical success rate and long-term patency rate in patients requiring hemodialysis, providing an optional vascular access for those with exhausted central vein resources. SVC puncture also avoided the use of left-sided catheters and preserved central vein resources. Caution should be given to avoid potential complications such as pleura injury and hemothorax.

Percutaneous endovascular arteriovenous fistula: A systematic review and meta-analysis.

Objective: Currently, percutaneous endovascular creation of arteriovenous fistula (AVF) shows excellent outcomes. However, few systematic research evidence to support clinical decision making on the benefit of endovascular AVF is available. The purpose of this study was to evaluate the efficacy and safety of endovascular AVF (endoAVF) in patients with renal failure. Methods: We searched the Medline, Embase, Cochrane Library, and ClinicalTrials.gov databases for studies on endovascular or endovascular versus surgery for the creation of AVF. Two reviewers independently selected studies and extracted data. A systematic review and meta-analysis were performed by Review Manager 5.4 software (Revman, The Cochrane Collaboration, Oxford, United Kingdom) and Stata 15.0 (Stata Corp, College Station, TX, United States). Results: A total of 14 case series and 5 cohort studies, with 1,929 patients, were included in this study. The technique success was 98.00% for endoAVF (95% CI, 0.97-0.99; I 2 = 16.25%). There was no statistically significant difference in 3 cohort studies between endovascular and surgical AVF for procedural success (OR = 0.69; 95% CI, 0.04-11.98; P = 0.80; I 2 = 53%). The maturation rates of endoAVF were 87.00% (95% CI, 0.79-0.93; I 2 = 83.96%), and no significant difference was observed in 3 cohort studies between the 2 groups (OR = 0.73; 95% CI, 0.20-2.63; P = 0.63; I 2 = 88%). Procedure-related complications for endoAVF was 7% (95% CI, 0.04-0.17; I 2 = 78.31%), and it did not show significant difference in 4 cohort studies between the 2 groups (OR = 1.85; 95% CI, 0.37-9.16; P = 0.45; I 2 = 59%). Conclusion: The endovascular creation of AVF is potentially effective and safe. These important data may provide evidence to support clinicians and patients in making decisions with endovascular AVF. But further research is great necessary due to lack of randomized controlled studies.

Sharp recanalization for long-segment superior vena cava occlusion in a hemodialysis patient with vascular resource exhaustion: a case report.

Hemodialysis is the lifeline of end-stage renal patients, and the correct choice of vascular access is vital to patients with vascular resource exhaustion. A 57-year-old female was admitted to the hospital due to catheter dysfunction. Color-doppler ultrasound (CDU) showed that the patient's inferior vena cava (IVC), right brachiocephalic vein, and long segment of the superior vena cava (SVC) were occluded. During surgery, we found that the obstruction of the SVC extended from the opening of the azygous vein to the junction of the SVC and the right atrium and was 6.9 cm in length. Under fluoroscopic guidance, the original tunneled cuffed catheter (TCC) was pulled out, a 4-French sheath was implanted into the right, and a guidewire was inserted to locate the distal end of the SVC. Another puncture needle was inserted from the right brachiocephalic vein into the distal end of the SVC and the steel core of the Rosch-Uchida Transjugular Liver Access Set (RUPS-100) was then inserted through the puncture needle. After correcting the positive and lateral position and determining the way in which the SVC entered the right atrium from the distal end, a 0.035-inch hard guidewire was then inserted into the right atrium through the steel core and a 6-mm balloon was used to dilate the SVC. The end of the catheter was then implanted into the IVC. No surgical complications occurred and at the 30-month follow-up and time of writing, the catheter remained primarily patent. The use of the RUPS-100 for sharp recanalization of an occluded long segment of the SVC can increase the likelihood of patient survival, but the risks during this operation are still not negligible and require precise guidance.

Efficacy and safety of recanalization with transseptal needle for chronic total occlusion of the brachiocephalic vein in hemodialysis patients.

BACKGROUND: Whilst there are effective techniques for the recanalization of central venous occlusions, recanalization of chronic total occlusions remains particularly challenging. This study aims to evaluate the safety and efficacy of recanalization using a transseptal needle in chronic total occlusions of the right brachiocephalic vein (RBV) in long-term hemodialysis patients. METHODS: In this single-center, retrospective study, maintenance hemodialysis patients with chronic total occlusion of the RBV were enrolled between February 2017 to March 2019 from West China Hospital of Sichuan University. Refractory lesions were defined as complete vascular occlusions with failed recanalization using conventional techniques. Occlusions were approached using a transseptal needle to penetrate which offers an alternative strategy with firm support force. Patient data, treatment outcomes and patency rates were collected and analyzed to assess the safety and efficacy of the technique. RESULTS: A total of 16 eligible patients were analyzed. The operation was successful in 13 of the 16 patients and the success rate was 81.25% (13/16). Twelve patients underwent percutaneous balloon dilatation and stent implantation after sharp recanalization, whilst one patient underwent balloon dilatation only. We achieved procedural success in 13 patients without surgical complications, and all of the patients were discharged in a stable condition. The primary patency rates at 3, 6 and 12 months after surgery were 100%, 84.6% and 69.2%, respectively. The primary assisted patency rates were 100%, 84.6% and 76.9%, respectively, and the secondary patency rates were 100%, 84.6% and 76.9%, respectively. CONCLUSIONS: This study demonstrates that recanalization of chronic total occlusions to the RBV using a transseptal needle is a safe and effective method after traditional guide wire and catheter techniques fail. It was also found that additional techniques are needed for recanalization in patients with RBV occlusion combined with proximal stenosis or occlusion of the right subclavian vein.

Management of tunneled-cuffed catheter-related right atrial thrombosis in hemodialysis patients.

OBJECTIVES: Catheter-related right atrial thrombosis (CRAT) is an underreported but potentially life-threatening complication associated with the use of tunneled-cuffed catheters among hemodialysis (HD) patients. Because little is known about the evidence-based guidelines for the optimal management of CRAT among HD patients, this article reports findings based on 20 patients diagnosed with CRAT after catheter replacement and anticoagulation treatment. METHODS: The article retrospectively reviews the hospital records of 20 HD patients treated in the West China Hospital with diagnosis of CRAT from March 2013 to May 2016. Once CRAT was diagnosed, tunneled-cuffed catheters were exchanged over a guidewire in situ and the locations of the new catheter tips were adjusted to be away from the original sites. Immediately after the insertion of a new tunneled-cuffed catheter and at the end of each HD session, both ports of the catheters were locked with unfractionated heparin solution. Patients younger than 70 years of age were treated with warfarin at a target International Normalized Ratio of 1.5 to 1.9, whereas those older than 70 years were treated with dual antiplatelet therapy. All patients were on regular dialysis without thrombolysis or thrombectomy. RESULTS: During the follow-up, two patients died of gastrointestinal massive hemorrhage and one died of acute myocardial infarction. No fatal pulmonary embolism or other CRAT complication-related deaths were observed. A total of eight patients had complete dissolution of CRAT, and 12 patients had reduction in thrombi size. CONCLUSIONS: Maintenance of HD by replacing catheters and providing oral anticoagulation/antiplatelet therapies may be an effective strategy for treating HD patients with CRAT.

Placement of tunneled cuffed vascular catheter through superior vena cava puncture.

OBJECTIVE: The purpose of this study was to assess the feasibility and safety of placement of tunneled cuffed catheters through direct percutaneous puncture of the superior vena cava (SVC) in patients with occluded right and left innominate veins. METHODS: This was a retrospective review of all patients with right and left innominate vein occlusions who underwent tunneled catheter placement with direct SVC puncture between January 2012 and December 2014. Under fluoroscopic guidance with the patient in a supine position, a 5F catheter was placed at the distal end of the SVC through the femoral vein, iliac vein, or hepatic vein. This catheter was used as a fluoroscopic target for the puncture. Following the guidance of fluoroscopy, the puncture needle and sheath were placed through a transcutaneous route with the insertion site 0.5 to 1.0 cm lateral-inferior to the clavicle head of the sternocleidomastoid, with the pathway inferior (caudal) to the clavicle, which allowed access of the guidewire and placement of a tunneled central venous catheter. RESULTS: The procedure succeeded in all 16 patients. During follow-up (mean, 12 months; range, 3-36 months), access failure due to thrombosis was observed in one patient. The remaining continued to function well until the end of the follow-up period or until the death of the patient (n = 3). No pneumothorax occurred. The most common complication was mediastinal hematoma after puncture failure in five patients. The diameter of the maximum hematoma was 2.2 cm, and all resolved spontaneously. CONCLUSIONS: In patients with central vein occlusion and exhaustion of conventional insertion sites, a tunneled central venous catheter can be safely placed through SVC puncture by the transcutaneous route.

Resolvin D1 Protects Lipopolysaccharide-induced Acute Kidney Injury by Down-regulating Nuclear Factor-kappa B Signal and Inhibiting Apoptosis.

BACKGROUND: Resolvin D1 (RvD1) is a newly found anti-inflammatory bioactive compound derived from polyunsaturated fatty acids. The current study aimed to explore the protective effect of RvD1 on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) and its possible mechanism. METHODS: Both in vivo and in vitro studies were conducted. Male BALB/c mice were randomly divided into control group (saline), LPS group (LPS 5 mg/kg), RvD1 group (RvD1 5 µg/kg + LPS 5 mg/kg), and blockage group (Boc-MLP 5 µg/kg + RvD1 5 µg/kg + LPS 5 mg/kg). Boc-MLP is a RvD1 receptor blocker. The mice were intraperitoneally injected with these drugs and recorded for general condition for 48 h, while the blood and kidneys were harvested at 2, 6, 12, 24, and 48 h time points, respectively (n = 6 in each group at each time point). Human proximal tubule epithelial cells (HK-2) were randomly divided into control group (medium only), LPS group (LPS 5 µg/ml), RvD1 group (RvD1 10 ng/ml + LPS 5 µg/ml), and blockage group (Boc-MLP 10 ng/ml + RvD1 10 ng/ml + LPS 5 µg/ml). The cells were harvested for RNA at 2, 4, 6, 12, and 24 h time points, respectively (n = 6 in each group at each time point). Blood creatinine was tested by using an Abbott i-STAT portable blood gas analyzer. Tumor necrosis factor-α (TNF-α) level was detected by ELISA. Kidney pathology was observed under hematoxylin and eosin (HE) staining and transmission electron microscope (TEM). We hired immune-histological staining, Western blotting, and fluorescence quantitative polymerase chain reaction to detect the expression of RvD1 receptor ALX, nuclear factor-kappa B (NF-κB) signaling pathway as well as caspase-3. Kidney apoptosis was evaluated by TUNEL staining. RESULTS: RvD1 receptor ALX was detected on renal tubular epithelials. Kaplan-Meier analysis indicated that RvD1 improved 48 h animal survival (80%) compared with LPS group (40%) and RvD1 blockage group (60%), while RvD1 also ameliorated kidney pathological injury in HE staining and TEM scan. After LPS stimulation, the mRNA expression of toll-like receptor 4, myeloid differentiation factor 88, and TNF-α in both mice kidneys and HK-2 cells were all up-regulated, while RvD1 substantially inhibited the up-regulation of these genes. Western blotting showed that the phosphorylated-IκB/IκB ratio in LPS group was significantly higher than that in the control group, which was inhibited in the RvD1 group. RvD1 could inhibit the up-regulation of cleaved-caspase-3 protein stimulated by LPS, which was prohibited in RvD1 blockage group. RvD1 group also had a lower proportion of apoptotic nuclei in mice kidney by TUNEL staining compared with LPS group. CONCLUSION: In LPS-induced AKI, RvD1 could decrease TNF-α level, ameliorate kidney pathological injury, protect kidney function, and improve animal survival by down-regulating NF-κB inflammatory signal as well as inhibiting renal cell apoptosis.

Allicin inhibits human renal clear cell carcinoma progression via suppressing HIF pathway.

Hypoxia-inducible factor 1-alpha (HIF-1α) protects hypoxic cells from apoptosis or necrosis under ischemic and anoxic conditions. Allicin is characterized by the anti-cancer characteristics. This study aims to explore whether allicin is involved in renal clear cell carcinoma progression through HIF-1α. A total of 40 RCC tissues and 39 normal renal tissues were collected H&E and immunohistochemistry were applied to study morphology changes. MTT assay and flow cytometry (FCM) were used to analyze cell viability and apoptosis. In vitro colony formation assay and wound healing assay were conducted to explore cell migration. The protein levels of Bcl-2, VEGF and HIF-1α were increased in RCC tissues. More importantly, treatment with allicin significantly decreased HIF-1α protein level, thereby reducing Bcl-2 and VEGF expression. In addition, allicin also obviously enhanced apoptotic cells. And colony formation capacity and cell migration rate were reduced in RCC-9863 cells treated with allicin. Further study revealed that overexpression of HIF-1α could partially repress allicin-induced downstream effects. To conclude, allicin inhibits human renal clear cell carcinoma progression partially by suppressing HIF pathway.

Involvement of inflammation-related miR-155 and miR-146a in diabetic nephropathy: implications for glomerular endothelial injury.

BACKGROUND: MicroRNAs have been demonstrated to play an important role in the pathogenesis of diabetic nephropathy (DN). In this study, we investigated both the repertoire of miRNAs in the kidneys of patients with DN and their potential regulatory role in inflammation-mediated glomerular endothelial injury. METHODS: The miRNA expression profiling of the renal biopsy samples was performed by a microarray analysis; then, in situ hybridization and real-time polymerase chain reaction (PCR) were used to determine the localization and expression of two of the miRNAs significantly up-regulated in human DN kidney samples, miR-155 and miR-146a, in the kidney tissues from type 1 and type 2 DN rat models. Human renal glomerular endothelial cells (HRGECs) cultured under high-glucose conditions were transfected with miR-155 and miR-146a mimics, and the transforming growth factor (TGF)-ß1, tumor necrosis factor (TNF)-α, and nuclear factor (NF)-κB expressions were examined by western blot, real-time PCR, and an electrophoresis mobility shift assay. RESULTS: The expression of both miR-155 and miR-146a was increased more than fivefold in the kidney samples of the DN patients compared with the controls, and the miR-155 expression was closely correlated with the serum creatinine levels (R = 0.95, P = 0.004). During the induction and progression of the disease in type 1 and type 2 DN rat models, miR-155 and miR-146a were demonstrated to increase gradually. In vitro, high glucose induced the over-expression of miR-155 and miR-146a in the HRGECs, which, in turn, increased the TNF-α, TGF-ß1, and NF-κB expression. CONCLUSIONS: Taken together, these findings indicate that the increased expression of miR-155 and miR-146a in the DN patients and in the experimental DN animal models was found to contribute to inflammation-mediated glomerular endothelial injury.