The value of inflow inversion recovery MRI for the diagnosis of transplant renal artery stenosis: comparison with digital subtraction angiography

Background To date, few data on the assessment of transplant renal artery stenosis (TRAS) by using inflow inversion recovery (IFIR) are available. The aims of this study was to evaluate the feasibility of IFIR in the assessment of TRAS using Digital Subtraction Angiography (DSA) as the reference. Results We retrospectively assessed the IFIR of 195 transplant renal arteries. The IFIR images for 194/195 arteries were judged to be of excellent, good, or moderate quality, and 1/195 was not diagnostic. There were 100 arteries with TRAS, of which 27 were subjected to DSA. The stenosis percentages were divided into five grades. Using DSA images, the TRAS in 27 patients were estimated as grade 1 (2, 7.4%), grade 2 (8, 29.6%), grade 3 (10, 37.0%), grade 4 (7, 25.9%) and grade 5 (0, 0%). In comparison, the TRAS was shown to be grade 1 (1, 3.7%), grade 2 (8, 29.6%), grade 3 (9, 33.3%), grade 4 (9, 33%) and grade 5 (0, 0%) in the IFIR images. The nonparametric Wilcoxon signed-rank test was used to compare IFIR with DSA. In addition, a Bland–Altman plot was used to estimate the agreement between IFIR and DSA measurements. There was no significant difference between IFIR and DSA measurements (p < 0.05). Conclusions Relative to the reference DSA, IFIR was shown to be noninvasive, accurate for the diagnosis and evaluation of TRAS.

3D-Printed Cold Preservation Device in Renal Autotransplantation for the Treatment of a Patient With Renal Artery Stenosis

Percutaneous transluminal angioplasty (PTRA) is a common treatment method for renal vascular disease (RVD). However, PTRA may not be effective in patients with abnormal vascular disease. Renal autotransplantation (RAT) has been used as an alternative therapy for these diseases. Restrictions due to intracorporeal kidney cold preservation and the renal function of intracorporeal RAT were not as well protected compared with open operation. We developed this technique of 3D-printed polylactide (PLA) cold jackets for laparoscopic complete intracorporeal RAT for the purpose of better protecting the renal function and determining the feasibility of this novel procedure. The procedure was successfully applied to a 51-year-old woman with bilateral renal artery stenosis. The operation time was 5 hours, and blood loss was 200 ml. The patient’s blood pressure remained constant throughout the operation, and the pressure was maintained at 120-140/70–90 mmHg without antihypertensive drugs 1 week after the operation. B-ultrasound showed that the blood flow signal of the transplanted kidney was normal and the boundary between the skin and medulla was clear. The patient was discharged 2 weeks after surgery. One year postoperatively, Doppler ultrasound of the autotransplant showed that the transplanted kidney was normal in size and shape. Radionuclide renal dynamic imaging revealed that the glomerular filtration rate (GFR) of the transplanted kidney was 36.9 ml/min. 3D-printed polylactide (PLA) cold jackets for laparoscopic complete intracorporeal RAT are a safe and effective method for the treatment of renal artery stenosis and represent a feasible method for preserving the renal function of severe renal artery stenosis patients; however, the technology is still at the exploratory stage and has room for further improvements.

CLINICAL CASE OF ARTERIAL HYPERTENSION IN A NEWBORN

Aim. To use personal clinical experience in monitoring and treating a newborn with persistent arterial hypertension (AH) due to left renal artery stenosis to demonstrate the current state of this problem in the context of limited experience of work with such rare pathologies in children.Materials and methods. The research was based on the examination and treatment of a newborn with persistent AH due to left renal artery stenosis. The complex of diagnostic procedures included: clinical and laboratory examinations, X-ray examination methods (with the use of contrast agents), magnetic resonance imaging, ultrasound examination and Dopplerography, and histological examination of surgical material.Results. Conservative treatment of the patient's AH with the use of antihypertensive agents did not achieve desired results.Taking into account possible etiologic and pathogenetic factors of AH in newborns, Doppler examination was performed to exclude congenital heart defects (coarctation of the aorta). Pathology was excluded.Cortisol and 17-OH progesterone levels were determined to exclude suprarenal pathology and showed the following: cortisol level was 173.9% higher than the maximum permissible level; 17-OH progesterone level was 9.9% higher than the norm.Considering the presence of neurological symptoms, an MRI of the brain with angiography was performed. No pathology was detected.Due to the presence of persistent arterial hypertension, which did not respond to medication, a CT with contrast was ordered, during which were revealed CT-signs of critically small diameter of the left renal artery (probable dissection) with pronounced cystic and ischemic changes of the lateral half of the left kidney without excretory function at 15 min. The main treatment measures included the following: adequate preoperative preparation, anesthetic support and the selection of an adequate and effective operative method to eliminate the pathology. The only available method of surgical intervention was nephrectomy - removal of the left kidney.Analyzing the results of the investigation, it can be stated that nephrectomy is the pathogenetic method of treatment of this pathology. Steady stabilization of arterial blood pressure was achieved within 1 hour after the operation.Conclusions. 1. When persistent AH is detected in a newborn, the presence of organic pathology should be excluded. 2. If the patient has organic pathology that causes a persistent increase in arterial blood pressure, the root cause of the pathology should be eliminated if possible. 3. Conservative treatment of persistent AH in children caused by renovascular or renal factors does not provide significant results and is not appropriate. 4. Nephrectomy is the pathogenetic method of treating AHT in a newborn with renal artery stenosis.

Refractory hypertension secondary to renal artery stenosis with a honeycomb-like structure

Background A honeycomb-like structure (HLS) is a rare abnormality characterized by a braid-like appearance. Angiograph and intravascular examination, including coherence tomography and intravascular ultrasound (IVUS), can further confirm the multiple intraluminal channels or honeycomb structure, which can also be described as looking like ‘swiss cheese’, a ‘spider web’ or a ‘lotus root’. Previous studies have mostly reported this abnormality in coronary arteries, with a few cases in renal arteries. More information about the characteristics and development of HLS is needed. Case presentation A 69-year-old Han man with resistant hypertension received abdominal enhanced computerised tomography and was revealed to have left renal artery stenosis with the possibility of left renal infarction. Renal artery angiography confirmed a 95% stenosis located in the proximal segment of the left renal artery, and the middle segment was blurred with multi-channel-like blood flow. Further IVUS was performed and identified multiple channels surrounded by fibrous tissue. It was a rare case of HLS in the renal artery secondary to the thrombus, with organisation and recanalisation. Balloon dilatation and stent implantation at the proximal segment of the left renal artery were performed successfully. Blood pressure was well controlled after the procedure. Conclusions The IVUS findings are helpful for forming interventional therapeutic strategies for HLS lesions in the renal artery.

Caloric Restriction Overcomes Pre-Diabetic and Hypertension Induced by High Fat Diet and Renal Artery Stenosis

Background: Caloric restriction (CR) is a type of dietary intervention that is essential in weight loss through modulation of critical pathways of metabolic control; however, it is not yet clear what this intervention results to in association with renovascular hypertension.Methods: Rats were divided into three groups: SHAM, and two groups that underwent surgery to clip the left renal artery and induce renovascular hypertension (OH and OHR). The SHAM diet was as follows: 14 weeks normolipidic diet; OH: 2 weeks normolipidic diet + 12 weeks hyperlipidic diet, both ad libitum; OHR, 2 weeks normolipidic diet + 8 weeks ad libitum high-fat diet + 4 weeks 40% calorie-restricted high-fat diet. Results: Rats in the OHR group had decreased blood pressure, body weight, and glucose levels. Reductions in insulinemia and in lipid and islet fibrotic areas in the OHR group were observed, along with increased insulin sensitivity and normalization of insulin-degrading enzyme levels. The expression of nicotinamide phosphoribosyltransferase (NAMPT), insulin receptor (IR), sirtuin 1 (SIRT1), and complex II proteins were increased in the liver tissue of the OHR group. Strong correlations, whether positive or negative, were evaluated via Spearman’s model between SIRT1, AMPK, NAMPT, PGC-1α, and NNMT expressions with the restoration of normal blood pressure, weight loss, glycemic and lipid panel, and mitochondrial adaptation. Conclusion: CR provided short-term beneficial effects to recover the physiological parameters induced by a high-fat diet and renal artery stenosis in obese and hypertensive animals. These benefits, even in the short term, can provide physiological benefits in the long term.

Percutaneous Revascularization for Atherosclerotic Renal Artery Stenosis: a Meta-analysis

Objective: This study aimed to investigate whether percutaneous revascularization (PR) was as effective and safe as medication therapy alone in patients with atherosclerotic renal artery stenosis (ARAS).Methods: We searched Embase, PubMed, and the Cochrane Library databases from their inception to July 31, 2021. We included randomized controlled trials (RCTs) reporting PR for ARAS. RevMan 5.3 was employed to conduct the analysis.Results: Of 469 screened studies, 9 were included in our study. A total of 2433 patients with ARAS were recorded. The results demonstrated that PR and medication had a similar antihypertensive effect on both systolic [mean difference (MD)= 0.37, 95% CI: -1.37 to 2.11, p= 0.68] and diastolic blood pressure (MD= -0.75, 95% CI: -2.84 to 1.34, p= 0.48). Meanwhile, there were no differences in all-cause mortality [risk ratio (RR) = 0.90, 95% CI: 0.74-1.10, p=0.31)], stroke (RR = 0.81, 95% CI: 0.53-1.98, p=0.32), congestive heart failure (RR = 0.89, 95% CI: 0.70-1.14, p= 0.36), and periprocedural complications (RR = 0.89, 95% CI: 0.72-1.10, p=0.28).Conclusions: The results revealed that PR was as effective and safe as medication therapy alone in patients with ARAS.

Living donor kidney transplant following nephrectomy for renal artery stenosis with arterial reconstruction and viability assessment using ex vivo normothermic perfusion

Ex vivo normothermic perfusion (EVNP) is increasingly recognised as a viability tool to increase organ utilisation in deceased donor transplantation. We report the use of EVNP to assess graft perfusion quality following indication nephrectomy and back-bench arterial reconstruction in a case of renal artery stenosis, unamenable to endovascular treatment. Once explanted, it was not possible to effectively cold perfuse the graft through the main renal artery or collaterals. An arterial reconstruction was performed with patch angioplasty using the largest collateral creating a single common stem. EVNP was used to assess organ perfusion and, therefore, viability. Excellent global perfusion was evident alongside urine production, demonstrating that the arterial reconstruction was satisfactory. A patient with end-stage renal disease was consented with particular attention to the uncertainty of the underlying donor disease process and long-term outcome of the reconstruction. Primary function was achieved and recipient estimated glomerular filtration rate (eGFR) remains stable at 58 mL/min/1.73 m² at 6 months.