SUPERSELECTIVE EMBOLIZATION OF THE RENAL ARTERIES AS A MONOTHERAPY OF KIDNEY TUMOR IN A PATIENT WITH HIGH ANESTHESIOLOGIC RISK

Introduction: Renal artery embolization is a minimally invasive X-ray endovascular operation that is used in the treatment of various urological diseases. This operation is of increasing interest due to its ability to occlude not only proximal, but also distal renal vessels with a low risk of complications. Recent developments in endovascular technology make embolization one of the effective and safe methods applicable to stop renal bleeding, preoperative preparation for surgical treatment of renal malignant tumors, and first-line treatment for angiomyolipomas. For a certain category of patients, renal artery embolization is practically no alternative method of treatment. This applies to comorbid patients with kidney tumors and aggravated somatic status, in whom the anesthetic risk makes open or laparoscopic surgical treatment impossible, and embolization can reduce symptoms, improve the quality of life of such patients and prolong the patient's life.Clinical case: we demonstrate the experience of X-ray surgical treatment of cT1aN0M0 left kidney cancer in an 80-year-old patient.Conclusion: Embolization of renal arteries in some cases can be an effective and safe alternative treatment for renal cell carcinoma in somatically burdened patients who cannot perform surgical treatment.

A preliminary animal study of thermal rheology fluid as a new temperature-dependent liquid intravascular embolic material

Purpose Thermal rheology (TR) fluid, which comprises polyethylene (PE) particles, their dispersant, and solvent, is a material that increases in viscosity to various degrees depending on the type and ratio of these constituents when its temperature rises. The viscosity of type 1 (TRF-1) increases more than that of type 2 (TRF-2) near rabbit body temperature. This preliminary animal study aimed to determine the basic characteristics and embolic effect of TR fluid by comparing TRF-1 and TRF-2. Materials and methods Twenty-four Japanese white rabbits underwent unilateral renal artery embolization using TRF-1 or TRF-2 and follow-up angiography at 7 or 28 days (4 subgroups, n = 6 each). Subsequently, the rabbits were euthanized, and the embolized kidneys were removed for pathological examination. The primary and final embolization rates were defined as the ratio of renal artery area not visible immediately after embolization and follow-up angiography, respectively, to visualized renal artery area before embolization. The final embolization rate and maximum vessel diameter filled with PE particles were compared between materials. Moreover, the embolic effect was determined to be persistent when a two-sided 95% confidence interval (CI) for the difference in means between the embolization rates was < 5%. Results The final embolization rate was significantly higher for the TRF-1 than for the TRF-2 at both 7 (mean 80.7% [SD 18.7] vs. 28.4% [19.9], p = 0.001) and 28 days (94.0% [3.5] vs. 37.8% [15.5], p < 0.001). The maximum occluded vessel diameter was significantly larger for TRF-1 than for TRF-2 (870 µm [417] vs. 270 µm [163], p < 0.001). The embolic effect of TRF-1 was persistent until 28 days (difference between rates − 3.3 [95% CI − 10.0–3.4]). Conclusion The embolic effect of TRF-1 was more persistent than that of TRF-2, and the persistency depended on the type and ratio of TR fluid constituents.

Non-Permanent Transcatheter Proximal Renal Artery Embolization for a Grade 5 Renal Injury with Delayed Recanalization and Preserved Renal Parenchymal Enhancement

Super-selective renal artery embolization is an increasingly popular technique for the management of traumatic, low-grade renal trauma. When performed in distal arterial branches, this intervention enables tissue preservation and arrest of hemorrhage, but it may not be practical in cases of multifocal, high-grade renal injuries. In such cases, surgical nephrectomy remains the more common treatment modality to ensure hemodynamic control. We present the unique case of a patient who presented in hemorrhagic shock following a major trauma that resulted in a grade 5 renal injury treated with complete renal artery embolization using Gelfoam, resulting in hemodynamic stabilization. Interestingly, imaging 1 month after embolization revealed residual enhancement of the inferior pole of the kidney, suggesting reconstitution of flow and partial renal salvage. Ultimately, transcatheter “nephrectomy” with careful selection of a temporary embolic agent may serve as a safe and efficient alternative to surgical nephrectomy with the added possibility of preserving partial renal perfusion and function in the emergent setting.

Renal artery embolization for spontaneous hemorrhage in patients with acquired cystic kidney disease: A 20-year single-center experience

Objectives: To evaluate the safety and effectiveness of transcatheter arterial embolization for controlling spontaneous hemorrhage in patients with acquired cystic kidney disease (ACKD). Methods: This retrospective study included 18 patients with ACKD (M:F=13:5; mean age, 56 years) who underwent renal artery embolization to control spontaneous hemorrhage between January 2001 and September 2020. The underlying etiology and clinical presentations were reviewed and previous computed tomography (CT) findings were analyzed. Furthermore, angiographic and embolization details, technical and clinical successes, and complications were assessed. Results: Subcapsular, perirenal, and pararenal hematomas were observed on CT scans for all patients. Contrast extravasation was observed in 15 / 17 patients (88%) on contrast-enhanced CT scans. Angiography showed active bleeding in 14 patients (78%; contrast extravasation [n=6], pseudoaneurysm [n=3], and both [n=5]), suspicious bleeding in 1 (5%), and no bleeding in 3 (17%). The technical and clinical success rates were 100% and 94% (17/18), respectively. Total and partial embolization was performed in 14 (78%) and 4 (22%) cases, respectively. Subsequent surgical nephrectomy was required for one patient with clinical failure due to recurrent bleeding despite total embolization. Procedure-related complications included mild post-embolization syndrome in one patient and contrast-induced nephropathy in five patients (28%) without long-term complications. Conclusions: Renal artery embolization is safe and effective for controlling spontaneous renal hemorrhage in patients with ACKD. doi: https://doi.org/10.12669/pjms.37.4.3999 How to cite this:Chen CS, Ahn H, Shin JH, Li HL, Kim JW, Ibrahim A, et al. Renal artery embolization for spontaneous hemorrhage in patients with acquired cystic kidney disease: A 20-year single-center experience. Pak J Med Sci. 2021;37(4):---------. doi: https://doi.org/10.12669/pjms.37.4.3999 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Safety of Renal Biopsy by Physicians with Short Nephrology Experience

Percutaneous renal biopsy is an essential tool for diagnosing various renal diseases; however, little is known about whether renal biopsy performed by physicians with short nephrology experience is safe in Japan. This study included 238 patients who underwent percutaneous renal biopsy between April 2017 and September 2020. We retrospectively analyzed the frequency of post-renal biopsy complications (hemoglobin decrease of ≥10%, hypotension, blood transfusion, renal artery embolization, nephrectomy and death) and compared their incidence among physicians with varied experience in nephrology. After renal biopsy, a hemoglobin decrease of ≥10%, hypotension and transfusion occurred in 13.1%, 3.8% and 0.8% of patients, respectively. There were no cases of post-biopsy renal artery embolism, nephrectomy, or death. The composite complication rate was 16.0%. The incidence of post-biopsy complications was similar between physicians with ≥3 years and <3 years of clinical nephrology experience (12.5% vs. 16.8%, p = 0.64). Furthermore, the post-biopsy composite complication rates were similar between physicians with ≥6 months and <6 months of clinical nephrology experience (16.3% vs. 15.6%, p > 0.99). Under attending nephrologist supervision, a physician with short clinical nephrology experience can safely perform renal biopsy.

A Uremic Goat Model Created by Subtotal Renal Artery Embolization and Gentamicin

A large animal model of (end-stage) kidney disease (ESKD) is needed for the preclinical testing of novel renal replacement therapies. This study aimed to create stable uremia via subtotal renal artery embolization in goats and induce a temporary further decline in kidney function by administration of gentamicin. Renal artery embolization was performed in five Dutch white goats by infusing polyvinyl alcohol particles in branches of the renal artery, aiming for the embolization of ~80% of one kidney and complete embolization of the contralateral kidney. Gentamicin was administered to temporarily further increase the plasma concentrations of uremic toxins. After initial acute kidney injury, urea and creatinine plasma concentrations stabilized 1.5 ± 0.7 months post-embolization and remained elevated (12 ± 1.4 vs. 5.6 ± 0.8 mmol/L and 174 ± 45 vs. 65 ± 5.6 µmol/L, resp.) during follow-up (16 ± 6 months). Gentamicin induced temporary acute-on-chronic kidney injury with a variable increase in plasma concentrations of small solutes (urea 29 ± 15 mmol/L, creatinine 841 ± 584 µmol/L, phosphate 2.2 ± 0.3 mmol/L and potassium 5.0 ± 0.6 mmol/L) and protein-bound uremic toxins representative of patients with ESKD. A uremic goat model characterized by stable moderate uremia was established via subtotal renal artery embolization with the induction of temporary severe acute-on-chronic kidney injury by the administration of gentamicin, allowing preclinical in vivo validation of novel renal replacement technologies.