Renal artery embolization-indications, technical approaches and outcomes

Renal angiomyolipoma selective arterial embolization: Australian tertiary centre experience over 10 years

INTRODUCTION

The purpose of this study is to evaluate the patient selection methods, treatment outcomes, complications, clinical and radiological follow-up after renal angiomyolipoma (AML) treatment with selective arterial embolization (SAE) in an Australian metropolitan tertiary centre.

METHODS

This study presents a retrospective single-centre review of patients' medical records who underwent SAE for renal AML during the period of 1st January 2012 and 1st January 2023.

RESULTS

A total of 32 SAE procedures for renal AML occurred during the study period. Three episodes were classified as emergency cases [9.38%] and the remaining 29 were treated electively. Mean AML size pre-treatment was 69.45 mm (range = 33-177; SD = 31.69). All AMLs demonstrated hyper-vascularity on contrast-enhanced cross-sectional imaging (arterial-phase enhancement characteristics and/or prominent tortuous feeding vessels) [n = 32; 100%] or an intralesional aneurysm or pseudoaneurysm [n = 12; 42.85%]. Periprocedural complications [n = 3; 9.38%] included: one intralesional haemorrhage after embolization, one vascular access site complication, and one lipiduria-associated urinary tract infection. No patients suffered a life-threatening complication, non-target embolization, deterioration in renal function or death following SAE. Re-treatment with SAE was performed in only three patients [10.71%]. Hospital mean length of stay was 1.58 days. Median durations of clinical and radiological follow-up post-treatment were 493 days (range = 104-1645) and 501 days (range = 35-1774), respectively. Follow-up imaging revealed AML total size reduction in all cases [mean = -17.17 mm; -26.51%] and 50% had obliteration of lesion hyper-vascularity after one episode of SAE. Outpatient clinical follow-up signifies that none of the patients included in the study have re-presented with lesion haemorrhage after successful SAE.

CONCLUSION

In this study, renal AMLs were treated safely with a high degree of success by using SAE, and there were very low rates of periprocedural complications. Follow-up of patients after SAE treatment of renal AML should include both radiological (assessment for reduction in lesion vascularity and size) and clinical review in an outpatient clinic setting (either by an interventional radiologist or urologist).

Arterial embolization in the treatment of multiple renal and hepatic hamartomas with spontaneous hemorrhage and 2-year follow-up: a case report

BACKGROUND

Hamartoma is a common benign tumor that usually occurs in the kidney, liver, lung, and pancreas. Large renal hamartomas may spontaneously rupture and hemorrhage, which is potentially life-threatening.

CASE PRESENTATION

This report describes a 46-year-old Han Chinese female patient with multiple renal and hepatic hamartomas with rupture and hemorrhage of giant hamartoma in the left kidney. She underwent arterial embolization three times successively, and her condition was stable during the 2-year follow-up. This report includes a review of the relevant literature CONCLUSIONS: the findings in this report and previous literature suggest that arterial embolization can not only rapidly treat hamartoma hemorrhage in the acute phase but can also effectively control multiple lesions in the long term after repeated multisite arterial embolization.

The effect of transarterial embolization and nephrectomy on acute kidney injury in patients with blunt renal trauma: An American College of Surgeons - Trauma Quality Improvement Program analysis

INTRODUCTION

Transarterial embolization (TAE) or nephrectomy for patients with blunt renal trauma might result in acute kidney injury (AKI). Thus, we analyzed the American College of Surgeons - Trauma Quality Improvement Program (TQIP) to validate this. We hypothesized that nephrectomy, and not TAE, would be a risk factor for AKI in patients with blunt renal trauma.

MATERIAL AND METHODS

Adult patients with blunt injuries from the TQIP between 2017 and 2019 were eligible for inclusion. The patients were divided into three treatment groups: conservative treatment, TAE, and nephrectomy. Multivariable logistic regression was used to clarify the AKI predictors.

RESULTS

The study included 12,843 patients, wherein 12,373 (96.3 %), 229 (1.8 %), and 241 (1.9 %) patients were in the conservative, TAE, and nephrectomy groups, respectively. A total of 269 (2.2 %), 20 (8.7 %), and 29 (12.0 %) patients had AKI in the three groups, respectively. Both TAE (odds ratio [OR], 2.367; 95 % confidence interval [CI], 1.372-3.900; p = 0.001) and Nephrectomy (OR, 2.745; 95 % CI, 1.629-4.528; p < 0.001) were a statistically significant predictor for AKI in the multivariable logistic regression.

CONCLUSIONS

TAE and nephrectomy were statistically associated with AKI in patients with blunt renal trauma. This result differs from our previous research findings that nephrectomy, but not TAE, was a risk factor for AKI in patients with blunt renal trauma. Further prospective and well-designed research may be needed.

A systematic review and meta-analysis on the efficacy of preoperative renal artery embolization prior to radical nephrectomy for renal cell carcinoma: Is it necessary?

INTRODUCTION

Radical nephrectomy for Renal Cell Carcinoma (RCC) is still the treatment of choice for all stages except for stage I and IV, which need patient selectivity. The purpose of Renal Artery Embolization (RAE) pre-operative before radical nephrectomy is to facilitate resection, reduce bleeding, and reduce the time to surgery, but the necessity of this procedure is still debatable. This study investigates the efficacy of pre-operative Renal Artery Embolization (PRAE) before radical nephrectomy for RCC patients.

METHODS

The systematic searches based on PRISMA guidelines were conducted in Pubmed, Scopus, Web of Science, Medrxiv, and ScienceDirect databases with pre-defined keywords. Both analyses, quantitative and qualitative, were performed to assess blood loss, transfusion rate, surgical time, Intensive Care Unit (ICU) stay, and hospital stay.

RESULTS

A total of 921 patients from 8 eligible studies were included. The blood loss was significantly lower in the PRAE group compared to the control group (p = < 0.00001; SMD -20 mL; 95%CI -0.29, -0.12). There is no statistically significant difference between RAE and without RAE in the transfusion rate nephrectomy (p = 0.53, OR 0.65; 95% CI 0.16, 2.57), mean operative time (p = 0.69; SMD 5.91; 95% CI -23.25, 35.07), mean length of hospital stay (p = 0.05; SMD 0.56; 95% CI 0.00, 1.12), and mean length of stay in the ICU (p = 0.45; SMD 11.61; 95% CI -18.35, 41.57) Conclusions: PRAE before radical nephrectomy significantly reduces blood loss in RCC patients but is similar in the surgical time, transfusion rate, and length of hospital stay and ICU stay.

Renal Biopsy for Diagnosis in Kidney Disease: Indication, Technique, and Safety

Renal biopsies are the gold standard for diagnosis, staging, and prognosis of underlying parenchymal kidney disease. This article provides an overview of the current indications and highlights ways to reduce bleeding complications in order to achieve optimal diagnostic yield with minimal risk to the patient. Novel indications have emerged from the increasing use of new molecularly targeted oncologic therapies in recent years, which often induce immune-mediated renal disease. On the other hand, the detection of specific antibodies against target antigens on podocytes in the sera of patients with new-onset nephrotic syndrome has now relativized the indication for biopsy in membranous nephropathy. The use of semi-automatic spring-loaded biopsy devices and real-time ultrasound considerably declined the complication rate and is the current standard. Percutaneous renal biopsies are overall a safe procedure if contraindications are considered. A coagulation disorder needs to be excluded beforehand, and an elevated blood pressure must be reduced to the normotensive range with medications. A laparoscopic approach or a radiology interventional procedure through the internal jugular vein may be considered for obtaining a kidney tissue sample if there is an urgent indication and a bleeding tendency cannot be adequately corrected. Major bleeding after a percutaneous renal biopsy can usually be managed with selective arterial embolization of the injured renal vessel. The use of a 16-gauge needle is the most reasonable compromise between diagnostic benefit and risk of complication. In the routine diagnostic, the biopsy specimen is examined with light microscopy, immunohistochemistry, and electron microscopy. Combination with modern molecular pathology techniques will contribute to more precise insights into the development and progression of kidney disease, which will likely refine future treatments in nephrology.

Janus particle-engineered structural lipiodol droplets for arterial embolization

Embolization (utilizing embolic materials to block blood vessels) has been considered one of the most promising strategies for clinical disease treatments. However, the existing embolic materials have poor embolization effectiveness, posing a great challenge to highly efficient embolization. In this study, we construct Janus particle-engineered structural lipiodol droplets by programming the self-assembly of Janus particles at the lipiodol-water interface. As a result, we achieve highly efficient renal embolization in rabbits. The obtained structural lipiodol droplets exhibit excellent mechanical stability and viscoelasticity, enabling them to closely pack together to efficiently embolize the feeding artery. They also feature good viscoelastic deformation capacities and can travel distally to embolize finer vasculatures down to 40 μm. After 14 days post-embolization, the Janus particle-engineered structural lipiodol droplets achieve efficient embolization without evidence of recanalization or non-target embolization, exhibiting embolization effectiveness superior to the clinical lipiodol-based emulsion. Our strategy provides an alternative approach to large-scale fabricate embolic materials for highly efficient embolization and exhibits good potential for clinical applications.

Renal arteriovenous malformation causing hematuria: Case report and review of the literature

RATIONALE

Renal arteriovenous malformations are rare vascular morphological anomalies that can be classified as congenital, idiopathic and acquired, of which congenital renal arteriovenous malformations are the most common. This disease is a rare cause of hematuria. In this case report, we report the diagnosis and treatment of a patient with renal arteriovenous malformation. We also review the symptoms, diagnosis and treatment of renal arteriovenous malformations in the published literature.

PATIENT CONCERNS

A 35-year-old female patient presented to a local hospital with right-sided lumbar abdominal pain with hematuria for 2 days. Physical examination showed percussion pain in the right renal area. Laboratory tests such as routine blood and blood biochemistry did not show any significant abnormalities when the patient entered the hospital. Considering the patient's medical history, a urological computed tomography scan showed blood accumulation in the right renal pelvis, upper middle ureter and bladder. Subsequently, routine blood tests showed that the patient's red blood cells and hemoglobin continued to decrease. An emergency renal arteriogram was performed, which showed a tortuous right upper renal pole branch artery and multiple thickened veins communicating with it.

DIAGNOSIS

This patient was diagnosed with cirsoid renal arteriovenous malformation.

INTERVENTIONS

Renal artery embolization was performed immediately after the renal arteriogram was performed on the patient.

OUTCOMES

On review of the angiogram, the tortuous right upper renal pole branch artery was found to be obstructed, and the thickened vein disappeared, and the renal vein was normally visualized in due course. On the third postoperative day, the patient was free of hematuria. Physical examination showed no percussion pain in the renal area. The patient healed and was discharged. A 1-year follow-up was performed and the patient gave feedback that she no longer had symptoms such as back pain and hematuria in her daily life.

LESSONS

This case illustrates that early use of vascular interventions is an important method for the diagnosis and treatment of cirsoid renal arteriovenous malformations.

Embolisation Using Microvascular Plugs for Peripheral Applications: Technical Results and Mid-Term Outcomes

The Micro Vascular Plug® (MVP, Medtronic) is a mechanical embolic agent available in small sizes that allows for distal embolisation. The objective of this retrospective observational single-centre study was to assess MVP embolisation procedures performed at a university hospital. The 33 patients who underwent MVP embolisation in 2021 were included (mean age, 64; 24 males and 9 females). The primary endpoint was technical success, which was defined as a full first-attempt occlusion with one or more MVPs, as documented on the end-of-procedure angiogram. In all patients, 51 MVPs were used overall, with other embolic agents in 23 of the 33 cases (usually coils and/or glue); 22 of the 33 procedures were emergent for bleeding and 11 were planned for other indications. Of the three technical failures, two were due to an angled target artery configuration precluding microcatheterisation and one to failure of the device to release from its wire. The technical success rate was thus 90.9%. No patient experienced MVP migration or other major complications. Five patients had recurrent clinical symptoms; in four cases, the cause was collateral development, and in one case, the cause was incomplete initial embolisation. No instances of recanalisation were documented during the short follow-up of 12 months, for a 100% secondary clinical success rate. At our tertiary-level centre, the MVP was both effective and safe for peripheral applications. Interventional radiologists should be conversant with the techniques and indications of MVP embolisation.

Complications after Nephron-sparing Interventions for Renal Tumors: Imaging Findings and Management

The two primary nephron-sparing interventions for treating renal masses such as renal cell carcinoma are surgical partial nephrectomy (PN) and image-guided percutaneous thermal ablation. Nephron-sparing surgery, such as PN, has been the standard of care for treating many localized renal masses. Although uncommon, complications resulting from PN can range from asymptomatic and mild to symptomatic and life-threatening. These complications include vascular injuries such as hematoma, pseudoaneurysm, arteriovenous fistula, and/or renal ischemia; injury to the collecting system causing urinary leak; infection; and tumor recurrence. The incidence of complications after any nephron-sparing surgery depends on many factors, such as the proximity of the tumor to blood vessels or the collecting system, the skill or experience of the surgeon, and patient-specific factors. More recently, image-guided percutaneous renal ablation has emerged as a safe and effective treatment option for small renal tumors, with comparable oncologic outcomes to those of PN and a low incidence of major complications. Radiologists must be familiar with the imaging findings encountered after these surgical and image-guided procedures, especially those indicative of complications. The authors review cross-sectional imaging characteristics of complications after PN and image-guided thermal ablation of kidney tumors and highlight the respective management strategies, ranging from clinical observation to interventions such as angioembolization or repeat surgery. Work of the U.S. Government published under an exclusive license with the RSNA. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available in the Online Learning Center. See the invited commentary by Chung and Raman in this issue.

Succinate Dehydrogenase Defects Giant Renal Cell Carcinoma

Succinate dehydrogenase (SDH)-deficient renal cell carcinoma (RCC) is a new subtype of RCC included in the 2016 edition of the WHO classification in RCC. SDH-defective RCC accounts for 0.05-0.2%, and preoperative diagnosis is difficult. We report a severe adherent RCC of inferior vena cava that underwent open radical nephrectomy after preoperative renal artery embolization. Postoperative histopathological examination diagnosed SDH-defective RCC; the clinicopathological stage was pT2b. After 10 months of follow-up, the patient had no evidence of disease recurrence. For patients with large RCC, interventional embolization can be selected to reduce intraoperative bleeding and blood transfusion, and it is recommended to complete interventional surgery within 3-4 h before surgery. SDH-deficient RCC is difficult to distinguish from other renal tumors in imaging, so immunohistochemical examination of SDHB is recommended for young and middle-aged patients, especially those under 45.

Acute haemorrhage from a large renal epithelioid angiomyolipoma: diagnostic and management considerations in a teenage patient with a rare cancer

Acute renal haemorrhage is a life-threatening condition that is complicated in the context of renal malignancy. Here, we present the case of a teenage male presenting acutely with a large, bleeding renal epithelioid angiomyolipoma (EAML) of the kidney-a rare cancer, which is part of the perivascular epithelioid cell tumour family. The patient was managed acutely with prompt resuscitation, transfer to a centre of expertise and haemorrhagic control using radiologically guided endovascular techniques; this subsequently permitted an oncologically sound procedure (radical nephrectomy, inferior vena cava thrombectomy and lymphadenectomy) to be performed within 24 hours. The description and discussion around this unique case summarises the patient's clinical journey, while exploring the current literature surrounding diagnosis and outcomes of patients with renal EAMLs.

Iatrogenic Renal Artery Injury in 90 Cases: Arteriographic Findings and Outcomes after Embolization for Bleeding

PURPOSE

To evaluate differences in arteriographic findings and outcomes after embolization among patients with a suspected iatrogenic renal arterial injury (IRAI).

MATERIALS AND METHODS

Patients at the authors' institution who underwent renal arteriography for suspected IRAIs after partial nephrectomy, biopsy, or percutaneous access over a 20-year period were included. Records, imaging, and outcomes were reviewed. Data analysis was performed using the Fisher exact or Kruskal-Wallis test.

RESULTS

Ninety arteriograms were performed on 83 patients after partial nephrectomy (n = 32), biopsy (n = 27), or percutaneous access (n = 24), including for nephrostomy/ureterostomy and stone removal. The median number of days between the index procedure and arteriogram was highest (15 days) after partial nephrectomy and lowest (5 days) after biopsy (P = .0001). Embolization was performed during 76% of arteriograms. If prearteriographic imaging showed positive results for IRAIs, embolization was performed in 67% versus 33% if imaging showed negative results (P = .005). The transfusion rate was higher after biopsy than after partial nephrectomy or percutaneous access (P = .002). Acute kidney injury after arteriogram occurred in 7% of patients; however, all returned to baseline by 1 week.

CONCLUSIONS

Despite the different mechanism of IRAIs in partial nephrectomy, biopsy, and percutaneous access, arteriographic findings and outcomes were overall similar among groups. Prearteriographic imaging can help identify IRAIs but cannot supersede the clinical judgment regarding indication for embolization. IRAIs can present acutely or after a long interim, although patients who underwent biopsy presented earlier and more frequently required a blood transfusion. IRAIs can be treated with embolization without permanent deleterious effects on renal function.

The effect of transarterial embolization versus nephrectomy on acute kidney injury in blunt renal trauma patients

PURPOSE

The impact of transarterial embolization (TAE) and nephrectomy on acute kidney injury (AKI) in blunt renal trauma patients remains unclear, and we used the National Trauma Data Bank (NTDB) to investigate this issue.

METHODS

Adult patients from the NTDB between 2007 and 2015 who survived traumatic events with blunt injuries were eligible for inclusion. The exclusion criteria were those without outcome information, who required dialysis, or with chronic renal failure prior to the traumatic injury. Patients sustaining hepatic, splenic, or pelvic fractures or who had bilateral nephrectomy were also excluded. The patients were divided into three treatment groups, including conservative treatment, TAE, and nephrectomy. Two statistical models, logistic regression (LR) and inverse probability treatment weighting (IPTW), were used to clarify the AKI predictors.

RESULTS

The study included 10,096 patients. There were 9697 (96.0%), 202 (2.0%) and 197 (2.0%) patients in the conservative, TAE and nephrectomy groups, respectively. Nephrectomy was a statistically significant predictor of AKI in blunt renal trauma patients in the standard LR (odds ratio [OR], 4.58; 95% confidence interval [CI] 1.92-10.38; p < 0.001) and IPTW (OR, 5.16; 95% CI 1.07-24.85; p = 0.023) models. In addition, TAE was not a risk factor for AKI in blunt renal trauma patients (p > 0.05 in all models).

CONCLUSION

AKI is less likely affect patients with blunt renal trauma with TAE than those with nephrectomy. Nephrectomy is a risk factor for AKI in blunt renal trauma patients. TAE should be considered first when blunt renal trauma patients need a hemostatic procedure.

Safety and efficacy of Endovascular Management of high-grade blunt renal injury

Objectives

To provide data on the safety and efficacy of renal arterial embolization (RAE) in patients with high-grade blunt renal injury.

Materials and methods

Fifteen patients with high-grade blunt renal injury (AAST grades IV-V) admitted to our hospital from July 2014 to December 2019 were retrospectively reviewed in this study. Their clinical success rate and complications were investigated accordingly.

Results

Fifteen patients with high-grade blunt renal injury, 13 men and 2 women with an average age of 41.6 years, including 11 hemodynamically unstable patients and 4 stable patients, were treated with RAE. Among these patients, 73.3% (11 of 15) had grade IV, and 26.7% (4 of 15) had grade V injuries, while 53.3% (8 of 15) patients had concomitant injuries. One patient received main RAE and 14 patients received selective RAE. The clinical success rate after the first embolization was 93.3% (14 of 15). RAE was repeated and was successfully performed in one patient with sustained hematuria. No significant difference in creatinine levels was found before and after embolization. During the follow-up period of 2–82 months, two patients required tube drainage due to urine leaks, one patient developed renal failure requiring renal replacement therapy, and one patient developed secondary hypertension.

Conclusions

RAE can provide a high success rate of hemostasis for both hemodynamically stable and unstable patients with high-grade blunt renal injury, and only minor complications are observed with this procedure.

In Vivo Sol-Gel Reaction of Tantalum Alkoxide for Endovascular Embolization

Liquid embolic agents are considered the most promising for various embolization procedures because they enable deep penetration. For realizing effective procedures, the delivery of liquid embolic agents should be guided under X-ray imaging systems and the solidification time should be optimized for the specific indication. The biocompatibility of embolic agents is also crucial because they remain in the vessel after embolization. In this study, new biocompatible embolic agents based on tantalum ethoxide is synthesized. Tantalum alkoxide liquid embolics (TALE) possess the radiopacity for fluoroscopy and can control the penetration depth by modifying the sol-gel kinetics. Furthermore, TALE can serve as drug carriers for synergistic treatment. Using these excellent characteristics, it is demonstrated that TALE agents can be used in various situations including the transarterial chemoembolization of hepatocellular carcinoma and embolotherapy of massive bleeding from the femoral artery.

Translational Development of a Silk-Elastinlike Protein Polymer Embolic for Transcatheter Arterial Embolization

Locally blocking blood flow to tumors with embolic materials is the key to transcatheter arterial embolization for treating hepatocellular carcinoma. Current microparticle agents do not deeply penetrate target tissues and are compatible with a very limited selection of therapeutic agents. Silk-elastinlike protein polymers (SELPs) combine the solubility of elastin and the strength of silk to create an easily injected liquid embolic that transition into a solid depot amenable to loading with drugs, gene therapy agents, or biologics. SELP, injected as liquid solution, penetrates the vasculature before transitioning to a solid hydrogel. The objective of this manuscript is to evaluate SELP embolization, stability, and biocompatibility at 7-, 30-, and 90-day survival intervals in a porcine model. SELP embolics selectively block blood flow in the kidneys and livers, with no off-target infarctions. As assessed with angiography, SELP renal embolization exhibits decreasing persistence for the duration of the 90-day study period. There is an increased presence of microscopic SELP emboli in the renal setting, compared to Embosphere. Histologically scored inflammatory reactions to SELP are decreased in both the renal and hepatic implantations compared to Embosphere. In conclusion, a bioresorbable SELP liquid embolic system deeply penetrates target tissue and selectively embolizes blood vessels in vivo.

A case of renal trauma successfully treated by close monitoring of intravesical pressure and subsequent intervention

Management of abdominal compartment syndrome (ACS) due to renal injury is important. A 21-year-old man was taken to an emergent care unit with grade IV right kidney trauma and hypovolemic shock due to a road traffic injury. Despite twice targeted transcatheter arterial embolization of a renal artery, intravesical pressure increased and blood pressure was difficult to maintain. After right nephrectomy and ligated the bleeding lumbar arteries and veins to avoid ACS, the patient's general condition improved, and he did not develop ACS. Monitoring of intravesical pressure may be useful for deciding treatment strategy.

Ultrasound-Guided Thrombin Injection for the Treatment of Bleeding Following Kidney and Liver Biopsies

The purpose of this study was to describe the technique and outcomes of percutaneous thrombin injection into the superficial aspect of actively bleeding liver and kidney biopsy tracks identified with color Doppler ultrasound with the aim of hemorrhage termination. After percutaneous thrombin injection, 15/16 (94%) patients did not require further intervention. Ultrasound-guided thrombin injection into the superficial site of active bleeding is an effective technique for terminating bleeding in the immediate post-procedure period following kidney and liver biopsies and should be considered if active bleeding persists on color Doppler after ≥30 minutes of compression and observation.

Magnetic Nanomaterials for Arterial Embolization and Hyperthermia of Parenchymal Organs Tumors: A Review

Magnetic hyperthermia (MH), proposed by R. K. Gilchrist in the middle of the last century as local hyperthermia, has nowadays become a recognized method for minimally invasive treatment of oncological diseases in combination with chemotherapy (ChT) and radiotherapy (RT). One type of MH is arterial embolization hyperthermia (AEH), intended for the presurgical treatment of primary inoperable and metastasized solid tumors of parenchymal organs. This method is based on hyperthermia after transcatheter arterial embolization of the tumor’s vascular system with a mixture of magnetic particles and embolic agents. An important advantage of AEH lies in the double effect of embolotherapy, which blocks blood flow in the tumor, and MH, which eradicates cancer cells. Consequently, only the tumor undergoes thermal destruction. This review introduces the progress in the development of polymeric magnetic materials for application in AEH.

Utility of preoperative vascular embolization of renal tumors with left renal vein tumor thrombus

INTRODUCTION AND OBJECTIVES

Preoperative renal artery embolization (PRAE) for large renal masses may be performed prior to nephrectomy in order to simplify the procedure and reduce intraoperative bleeding. The objective of this work is to determine the role of PRAE on intraoperative bleeding and postoperative complications in left renal tumors with tumor thrombus limited to the left renal vein (level 0).

MATERIAL AND METHODS

Retrospective analysis to evaluate 46 patients who underwent left radical nephrectomy and thrombectomy for the treatment of renal cell carcinoma with level 0 tumor thrombus during the period 1990-2020. PRAE was limited to those cases in which surgical access to the main renal artery was presumed a priori difficult in the preoperative imaging study (n = 9; 19.6%). Intraoperative bleeding was estimated based on the perioperative transfusion rate, and postoperative complications were categorized according to the Clavien-Dindo classification. The Chi-squared test was used for comparisons. A multivariate analysis was performed to identify predictors of transfusion and complications.

RESULTS

There were no significant differences in the overall complication rate (11.1% vs. 32.4%, p = 0.19), major complication rate (0% vs. 8.1%, p = 0.51), or transfusion rate (11.1% vs. 19%, p = 0.49) between both groups (PRAE vs. non-PRAE). In the multivariate analysis, PRAE did not behave as a predictor of complications (OR: 0.11, 95%CI 0.01-2.86; p = 0.18) nor transfusion (OR: 0.46, 95%CI 0.02-7.38; p = 0.58).

CONCLUSIONS

In our study on left RCC with level 0 tumor thrombus and difficult access to the main renal artery, PRAE was not associated with increased bleeding or postoperative complications, and it did not behave as an independent predictor of these variables. Therefore, it could be used as a preoperative maneuver to facilitate vascular management in selected cases.

Different Treatments of Symptomatic Angiomyolipomas of the Kidney: Two Case Reports

Development of more sensitive imaging techniques has caused an increase in the number of diagnosed small renal tumors. Approximately 2-3% of these lesions are proved to be angiomyolipomas (AML), a rare benign tumor of the kidney sometimes causing pain and hematuria. The most required approach is observation, but in the case of recurrent symptoms or larger tumors, which may cause bleeding, a more active treatment is required. We present two cases of symptomatic AML tumors of different sizes in the kidney: one treated with transarterial embolization (TAE), and the other with percutaneous cryoablation (CRA). The lesions were diagnosed on the basis of contrast-enhanced computed tomography (CT) scan and magnetic resonance imaging (MRI). Both treatments proved to be effective and safe for treating renal AMLs. A follow-up carried out, based on contrast-enhanced CT scan, confirmed complete treatment of AML and decreased lesion size. There are myriad minimally invasive approaches for the treatment of renal AMLs, and the preservation of renal function remains a priority. The most popular treatment option is the selective renal artery embolization. Owing to its limited invasiveness, CRA could be an attractive option for the preventive treatment of AML.

Long-term renal function outcomes after renal cryoablation complicated by major hemorrhage requiring selective transarterial embolization

PURPOSE

To determine long-term renal function outcomes after renal cryoablation complicated by major hemorrhage requiring transarterial embolization compared to patients who underwent uncomplicated renal cryoablation without major hemorrhage.

METHODS

Utilizing a matched cohort study design, retrospective review identified 23 patients who underwent percutaneous image-guided renal cryoablation complicated by major hemorrhage requiring ipsilateral transarterial embolization (TAE group) and a control group of 23 patients who underwent uncomplicated renal cryoablation matched 1:1 by age, gender and RENAL Nephrometry score at a single institution from 1/1/2005 to 12/31/2019. Primary outcome parameters included change in creatinine (mg/dl) and estimated glomerular filtration rate (ml/min/1.73 m²; eGFR) from baseline and were compared between TAE and control group using a paired t-test.

RESULTS

There was a significantly higher proportion of patients on pre-ablation anticoagulation in the TAE v. control group (30% v. 4%; p = 0.047), but all patients were off anticoagulation and with normal coagulation parameters at the time of cryoablation. Otherwise there were no significant differences in clinical, renal tumor, Charlson co-morbidity index, baseline renal function or cryoablation parameters between the TAE and control group. In the post-ablation period, there was trend toward greater increase in creatinine from baseline to worst post-ablation creatinine in the TAE v. the control group (+ 0.5 ± 0.7 mg/dl v. 0.2 ± 0.1 mg/dl; p = 0.056). However, at a mean follow-up of 42.7 ± 35.7 months, there was no significant difference between the TAE and control group in creatinine (p = 0.68), eGFR (p = 0.60) or change from baseline in creatinine (p = 0.28), eGFR (p = 0.80) or CKD stage (p = 0.74). No patient required initiation of hemodialysis.

CONCLUSION

Selective transarterial embolization for post-renal cryoablation hemorrhage does not significantly affect long-term renal function compared to cryoablation alone. Pre-ablation anticoagulation despite normal coagulation at time of ablation may be a risk factor for post-ablation hemorrhage, and warrants further evaluation when considering pre-ablation embolization.

Endovascular embolization in renal trauma: a narrative review

Approximately 1–3% of all trauma patients have a renal injury. Eighty percent of renal trauma is due to blunt injury, with the remainder due to penetrating trauma which is most often iatrogenic. Contrast enhanced computed tomography is used to triage patients and offers a quick and accurate assessment of any potential organ injury. If injury is present, The American Association for the Surgery of Trauma grading system can both grade renal injuries and be used to help guide management and intervention. Grades are assigned based on imaging and clinical features of renal trauma, and have prognostic and treatment implications for patients. The objective of this narrative review is to identify optimal management of patients with renal trauma, specifically which patients can be treated with endovascular interventions following renal trauma, which can be observed, and which would be best managed surgically. For hemodynamically stable patients with renal trauma, endovascular angiography and embolization is a non-invasive approach that can be used to control bleeding and potentially avoid surgery or nephrectomy in select cases. Future research is needed to determine if a specific antibiotic regimen is needed prior to or following embolization. Further research is needed to evaluate the effectiveness of endovascular management of high-grade renal trauma (grade V). Complications of renal embolization include short-term hypertension, long term hypertension in cases of significant ischemia, acute kidney injury, and infection.

The role of angioembolization in the management of blunt renal injuries: a systematic review

Background

Recently, renal angioembolization (RAE) has gained an important role in the non-operative management (NOM) of moderate to high-grade blunt renal injuries (BRI), but its use remains heterogeneous. The aim of this review is to examine the current literature on indications and outcomes of angioembolization in BRI.

Methods

We conducted a search of MEDLINE, EMBASE, SCOPUS and Web of Science Databases up to February 2021 in accordance with PRISMA guidelines for studies on BRI treated with RAE. The methodological quality of eligible studies and their risk of bias was assessed using the Newcastle–Ottawa scale

Results

A total of 16 articles that investigated angioembolization of blunt renal injury were included in the study. Overall, 412 patients were included: 8 presented with grade II renal trauma (2%), 97 with grade III renal trauma (23%); 225 with grade IV (55%); and 82 with grade V (20%). RAE was successful in 92% of grade III–IV (294/322) and 76% of grade V (63/82). Regarding haemodynamic status, success rate was achieved in 90% (312/346) of stable patients, but only in 63% (42/66) of unstable patients. The most common indication for RAE was active contrast extravasation in hemodynamic stable patients with grade III or IV BRI.

Conclusions

This is the first review assessing outcomes and indication of angioembolization in blunt renal injuries. The results suggest that outcomes are excellent in hemodynamic stable, moderate to high-grade renal trauma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-021-00873-w.

Predictors of renal angioembolization outcome: A retrospective analysis with 148 patients at a tertiary urology institute

Objective

The aim of this study was to evaluate the predictor of unsuccessful outcome of renal angioembolization (RAE). Knowing those predictors may help in avoiding unnecessary RAE procedures and their associated side effects, while helping to prepare for an alternate procedure and improving patient's overall satisfaction.

Methods

A retrospective analysis between January 2006 and December 2018 was performed, and the indications for RAE were classified into post-traumatic, iatrogenic, renal tumors, and spontaneous. Patients who underwent RAE prior to nephrectomy were eliminated. Computed tomography angiography was performed in patients with normal renal function and those who had no contrast allergy, otherwise magnetic resonance angiography was performed. For the purpose of statistical analysis, we stratified patients into two main categories based on the final outcome—successful or failed.

Results

Of 180 patients, 32 with negative angiography were eliminated, leaving 148 patients; 136 (91%) had successful outcomes after one or more trials and 12 had unsuccessful outcomes. The mean age was 45±15 years, and 105 (71%) were male. Neither gender, side of the lesion, presence of hematuria, indication for RAE, nor the type of lesion affected the outcome. On the other hand, renal anatomy with presence of accessory artery was the only predictor to failed RAE (p=0.001). Failed RAE trial was a predictor for nephrectomy as a secondary procedure (p=0.03).

Conclusion

No pre-procedural predictors could anticipate the RAE outcome, and different indications can be scheduled to RAE, which is equally effective. The presence of accessory renal artery on diagnostic angiography is the only factor that may predict the failure of the procedure.

Utility of preoperative vascular embolization of renal tumors with left renal vein tumor thrombus

INTRODUCTION AND OBJECTIVES

Preoperative renal artery embolization (PRAE) for large renal masses may be performed prior to nephrectomy in order to simplify the procedure and reduce intraoperative bleeding. The objective of this work is to determine the role of PRAE on intraoperative bleeding and postoperative complications in left renal tumors with tumor thrombus limited to the left renal vein (level 0).

MATERIAL AND METHODS

Retrospective analysis to evaluate 46 patients who underwent left radical nephrectomy and thrombectomy for the treatment of renal cell carcinoma with level 0 tumor thrombus during the period 1990-2020. PRAE was limited to those cases in which surgical access to the main renal artery was presumed a priori difficult in the preoperative imaging study (n=9; 19.6%). Intraoperative bleeding was estimated based on the perioperative transfusion rate, and postoperative complications were categorized according to the Clavien-Dindo classification. The Chi-squared test was used for comparisons. A multivariate analysis was performed to identify predictors of transfusion and complications.

RESULTS

There were no significant differences in the overall complication rate (11.1% vs. 32.4%, P=.19), major complication rate (0% vs.8.1%, P=.51), or transfusion rate (11.1% vs. 19%, P=.49) between both groups (PRAE vs. non-PRAE). In the multivariate analysis, PRAE did not behave as a predictor of complications (OR:0.11, 95%CI 0.01-2.86; P=.18) nor transfusion (OR:0.46, 95%CI 0.02-7.38;P=.58).

CONCLUSIONS

In our study on left renal cell carcinomas with level 0 tumor thrombus and difficult access to the main renal artery, PRAE was not associated with increased bleeding or postoperative complications, and it did not behave as an independent predictor of these variables. Therefore, it could be used as a preoperative maneuver to facilitate vascular management in selected cases.

Renal Arteries Revisited: Anatomy, Pathologic Entities, and Implications for Endovascular Management

The renal arteries (RAs) are important vessels that usually arise from the abdominal aorta and supply the kidneys; thus, these arteries play a vital role in physiologic functions such as hemofiltration and blood pressure regulation. An understanding of the basis for embryologic development and the frequently variable anatomy of the RAs is necessary to fully appreciate the range of diseases and the implications for procedural planning. Hemorrhage from an RA is relatively common and is typically traumatic or spontaneous, with the latter form often seen in association with underlying tumors or arteriopathy. Accurate diagnostic evaluation of RA disease due to conditions such as atherosclerosis, fibromuscular dysplasia, vasculitis, aneurysm, arteriovenous shunt, embolic disease, and dissection is dependent on the use of multimodality imaging and is essential for selecting appropriate clinical management, with endovascular therapy having a key role in treatment. Surgical considerations include extra-anatomic renal bypass, which remains an important treatment option even in this era of endovascular therapy, and RA embolization as an adjunct to tumor surgery. A novel area of research interest is the potential role of RA denervation in the management of refractory hypertension. ^©RSNA, 2021.

Congenital renal arteriovenous malformation: a rare cause of visible haematuria

We report a case of renal arteriovenous malformation (AVM) and describe its angioarchitecture and endovascular management. A 28-year-old male patient presented with visible painless haematuria. CT of the abdomen showed a right renal AVM. Digital subtraction angiography of the right renal vessels showed an AVM of middle and lower pole segmental arteries with communication to a large saccular aneurysm, which was arising from the right main renal vein. Complete occlusion of the AVM was done by using glue (a mixture of n-butyl-cyanoacrylate and lipiodol), resulting in nonvisualisation of the aneurysm on angiography. His vital signs were stable during the procedure. Follow-up CT after 12 months showed no residual flow in the aneurysm, normal upper pole renal parenchyma and nonvisualisation of AVM. Early diagnosis of this clinical entity is of paramount importance for proper management as it can cause massive blood loss and rapid clinical deterioration.

Endovascular Interventional Radiology of the Urogenital Tract

Interventional radiology of the male urogenital system includes percutaneous and endovascular procedures, and these last consist mostly of transcatheter arterial embolizations. At the kidney level, arterial embolizations are performed mainly for palliative treatment of parenchymal tumors, for renal traumas and, less frequently, for arteriovenous fistulas and renal aneurysms and pseudoaneurysms. These latter may often require emergency intervention as they can cause renal or peri-renal hematomas or significant hematuria. Transcatheter arterial embolization is also an effective therapy for intractable severe bladder hematuria secondary to a number of neoplastic and inflammatory conditions in the pelvis, including unresectable bladder cancer and radiation-induced or cyclophosphamide-induced hemorrhagic cystitis. Endovascular interventional procedures for the penis are indicated for the treatment of post-traumatic priapism. In this article, we review the main endovascular radiological interventions of the male urogenital system, describing the technical aspects, results, and complications of each procedure at the various anatomical districts.

Factors Predictive of Selective Angioembolization Failure for Moderate- to High-grade Renal Trauma: A French Multi-institutional Study

BACKGROUND

Angiography with selective angioembolization (SAE) is safe and effective in addressing bleeding in patients with renal trauma. However, there are no validated criteria to predict SAE efficacy.

OBJECTIVE

To evaluate factors predictive of SAE failure after moderate- to high-grade renal trauma.

DESIGN, SETTING, AND PARTICIPANTS

TRAUMAFUF was a retrospective multi-institutional study including all patients who underwent upfront SAE for renal trauma in 17 French hospitals between 2005 and 2015.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was SAE efficacy, defined as the absence of repeat SAE, salvage nephrectomy, and/or death for each patient.

RESULTS AND LIMITATIONS

Out of 1770 consecutive patients with renal trauma, 170 (9.6%) with moderate- to high-grade renal trauma underwent SAE. Overall upfront SAE was successful in 131 patients (77%) and failed in 39 patients: six patients died after the embolization, ten underwent repeat SAE, 22 underwent open nephrectomy, and one underwent open surgical exploration. In multivariate logistic regression analysis, gross hematuria (odds ratio [OR] 3.16, 95% confidence interval [CI] 1.29-8.49; p=0.015), hemodynamic instability (OR 3.29, 95% CI 1.37-8.22; p=0.009), grade V trauma (OR 2.86, 95% CI 1.06-7.72; p=0.036), and urinary extravasation (OR 3.49, 95% CI 1.42-8.83; p=0.007) were predictors of SAE failure. The success rate was 64.7% (22/34) for patients with grade V trauma and 59.6% (31/52) for those with hemodynamic instability. The study was limited by its retrospective design and the lack of a control group managed with either surgery or surveillance.

CONCLUSIONS

We found that gross hematuria, hemodynamic instability, grade V trauma, and urinary extravasation were significant predictors of SAE failure. However, success rates in these subgroups remained relatively high, suggesting that SAE might be appropriate for those patients as well.

PATIENT SUMMARY

Selective angioembolization (SAE) is a useful alternative to nephrectomy to address bleeding in patients with renal trauma. Currently, there are no validated criteria to predict SAE efficacy. We found that gross hematuria, hemodynamic instability, grade V trauma, and urinary extravasation were significant predictors of SAE failure.

A Critical Review on the Synthesis of Natural Sodium Alginate Based Composite Materials: An Innovative Biological Polymer for Biomedical Delivery Applications

Sodium alginate (Na-Alg) is water-soluble, neutral, and linear polysaccharide. It is the derivative of alginic acid which comprises 1,4-β-d-mannuronic (M) and α-l-guluronic (G) acids and has the chemical formula (NaC6H7O6). It shows water-soluble, non-toxic, biocompatible, biodegradable, and non-immunogenic properties. It had been used for various biomedical applications, among which the most promising are drug delivery, gene delivery, wound dressing, and wound healing. For different biomedical applications, it is used in different forms with the help of new techniques. That is the reason it had been blended with different polymers. In this review article, we present a comprehensive overview of the combinations of sodium alginate with natural and synthetic polymers and their biomedical applications involving delivery systems. All the scientific/technical issues have been addressed, and we have highlighted the recent advancements.

Target delivery of drug carriers in mice kidney glomeruli via renal artery. Balance between efficiency and safety

Targeting drug delivery systems is crucial to reducing the side effects of therapy. However, many of them are lacking effectiveness for kidney targeting, due to systemic dispersion and accumulation in the lungs and liver after intravenous administration. Renal artery administration of carriers provides their effective local accumulation but may cause irreversible vessel blockage. Therefore, the combination of the correct administration procedure, suitable drug delivery system, selection of effective and safe dosage is the key to sparing local therapy. Here, we propose the 3-μm sized fluorescent capsules based on poly-L-arginine and dextran sulfate for targeting the kidney via a mice renal artery. Hemodynamic study of the target kidney in combination with the histological analysis reveals a safe dose of microcapsules (20 × 10⁶), which has not lead to irreversible pathological changes in blood flow and kidney tissue, and provides retention of 20.5 ± 3% of the introduced capsules in the renal cortex glomeruli. Efficacy of fluorescent dye localization in the target kidney after intra-arterial administration is 9 times higher than in the opposite kidney and after intravenous injection. After 24 h microcapsules are not observed in the target kidney when the safe dose of carriers is being used but a high level of fluorescent signal persists for 48 h indicating that fluorescent cargo accumulation in tissues. Injection of non-safe microcapsule dose leads to carriers staying in glomeruli for at least 48 h which has consequences of blood flow not being restored and tissue damage being observed in histology.

Changing paradigms of management of isolated blunt renal trauma

Introduction

The last thirty years has seen a change in management of renal trauma with progression more towards nonoperative management; however there is lack of guidelines of many practical aspects for conservative management of renal trauma. Here we are sharing our experience of managing isolated renal trauma over a period of five years.

Materials and methods

The study was conducted in a tertiary care centre of eastern part of India from April 2015–March 2020. It was a retro-prospective study and included cases of isolated blunt renal trauma managed in our hospital.

Results

A total of 61 cases of isolated blunt renal trauma were treated in the mentioned time period. Seventeen (28%) cases were of AAST Grade IV and five (8%) Grade V injury. Blood transfusion was required in eighteen (29%) cases during management. In eight (47%) cases of Grade IV injury and two (40%) cases of Grade V injury angioembolization was done. In two (11.7%) cases of Grade IV injury ureteral stenting was performed. Delayed surgical exploration and nephrectomy was required in one case of Grade V injury because of failed angioembolization and one Grade IV injury due to sepsis. One death was encountered in Grade V injury who had delayed presentation with haemorrhagic shock and underwent immediate surgical exploration. On follow up four patients (23%) of Grade IV injury and one patient of Grade III injury and two patients (40%) of Grade IV injury developed hypertension. The remaining patients were found to be normal.

Conclusion

Conservative management of renal trauma is the norm nowadays. Angioembolisation was found to be one of the strongest armamentarium when patient needs intervention. Surgery is rarely contemplated, mostly in hemodynamically unstable high grade trauma patients.

"Endourological closure of a malformative vascular source of bleeding using the VortX 0.018" coil®"

AIMS

Renal vascular malformations, congenital or acquired, are sometimes challenging for urologists and interventional radiologists to resolve. Arterovenous fistulas and pseudoaneuryms are usually embolized by interventional radiologists, with a low rate of complications. We propose a new endourological/interventional radiology technique to treat a source of arterovenous bleeding coming from a renal calyx in a minimally invasive way.

METHODS

A combined endourological and interventional radiology procedure is described, using a Flexible Fiberoptic Ureteroscopes to undertake a retrograde intrarenal surgery (RIRS) to identify the source of bleeding; subsequently the VortX Coil® is inserted through a microcatheter to stop the bleeding and the correct position of the VortX coil is evaluated. Furthermore, we made a literature research on Pubmed and Medline to look for similar procedures.

RESULTS

In case of a renal bleeding that could not be treated by endovascular way, a combined urological and interventional radiology procedure can be undertaken. We did not find similar endourological and interventional radiology procedure on Pubmed and Medline, so this is the first tecnique of endourological closure of a bleeding point using a coil.

CONCLUSION

From our experience this could be a mininvasive technique to solve renal bleedings coming from a calyx that are not found by endovascular approach. Indeed, in our knowledge, the technique here described is the first that provides the use of an endovascular coil by endourological way in renal vascular malformations.

Value of Angioembolization in the Treatment of Iatrogenic Renal Vascular Injury Assisted by 3-Dimensional Digital Subtraction Angiography

BACKGROUND This study was conducted to investigate the reliability and efficacy of polyvinyl alcohol combined with coils in the embolization of iatrogenic renal vascular injury with the assistance of 3-dimensional digital subtraction angiography (3D-DSA). MATERIAL AND METHODS Twenty-six patients with minimally invasive renal bleeding who underwent transarterial embolization from January 2012 to January 2019 in our hospital were included in the study. We obtained demographic data from these patients, as well as information on clinical presentation, renal procedures used for treatment, and perioperative details. The changes in renal function tests, serum hemoglobin, serum hematocrit, and technetium Tc 99m dimercaptosuccinic acid (99mTc-DMSA) levels pre- and postembolization were compared. In addition, the embolic area and the technical and clinical success rates were analyzed. Finally, an angiographic manifestation of the renal artery, 3D-DSA, and the effect of embolization were analyzed retrospectively. RESULTS All patients achieved technical and clinical success after embolization (100%, 26/26). There were no significant differences between pre- and postoperative estimated glomerular filtration rate, serum parameters, and 99mTc-DMSA. The embolic area was 12%±10%. Patients did not exhibit severe complications during the follow-up period. CONCLUSIONS Proximal embolization technique assisted by 3D-DSA for renal iatrogenic hemorrhage and vascular lesions is both safe and efficacious, offering high rates for both clinical and technical success. It maximizes the protection of the kidney and reduces the rate of renal resection.

Renal Artery Embolization for Acute Renal Hemorrhage: A Single-Center Experience

Background

Emergency renal artery embolization (RAE) is a useful method in treating renal trauma and bleeding renal tumors. The aim of this study was to evaluate the clinical efficacy and safety of emergency RAE, and factors associated with RAE failure.

Methods

This retrospective study included patients treated with emergency RAE for acute renal hemorrhage between 1 January 2009 and 31 October 2019 in Srinagarind Hospital. The embolization was performed using coils, glues, and/or gel foams. Factors associated with unsuccessful outcomes were analyzed using univariate and multivariate regression analyses.

Results

A total of 94 patients were treated at the center during the study period with the clinical success rate of 91.5%. The most common cause of acute renal hemorrhage was iatrogenic injury (76.5%). Factors associated with unsuccessful RAE according to multivariate analyses were hypertension (adjusted odds ratio [AOR] 24.2) and ruptured tumor/aneurysm (AOR 26.8).

Conclusion

RAE is an effective procedure for acute renal hemorrhage. Hypertension and ruptured tumor/aneurysm were negative predictors for success.

Cytoreductive Nephrectomy in Metastatic Patients with Signs or Symptoms: Implications for Renal Cell Carcinoma Guidelines

The role of cytoreductive nephrectomy (CN) patients with metastatic renal cell carcinoma (mRCC) is unclear. To define the proportion of symptomatic mRCC, to investigate the impact of CN on symptomatic improvement and perioperative morbidity, and to elucidate the trade-off between such benefit and harm, an observational study of 317 mRCC patients treated with CN was performed. Symptomatic mRCC was defined as the presence of any sign or symptom causally related to the disease. Sign or symptom resolution and improvement were defined as the absence of all the signs and symptoms recorded at baseline, and the absence of at least one sign or symptom recorded at baseline, respectively. Perioperative morbidity was assessed using the Clavien-Dindo classification. Response to CN was classified as beneficial, mixed, or harmful according to the trade-off between symptomatic improvement and perioperative morbidity. The proportions of local, metastasis-specific, and general signs or symptoms were 37%, 23%, and 27%, respectively. The proportions of any sign or symptom resolution and improvement after CN were 43% and 71%, respectively. The proportions of local sign or symptom resolution and improvement after CN were 91% and 95%, respectively. The risks of any complication and major complication were 37% and 10%, respectively. At regression analysis, symptomatic status was not associated with perioperative morbidity. The proportion of beneficial response was invariably higher than the proportion of harmful response. At mRCC diagnosis, two out of three patients suffer from any sign or symptom, and one out of three suffers from local signs or symptoms. CN has a positive impact on symptomatic status. PATIENT SUMMARY: Most metastatic renal cell carcinoma patients are symptomatic, and they should be aware that cytoreductive nephrectomy has a positive impact on symptomatic status.

Unilateral nephrectomy versus renal arterial embolization and technique survival in peritoneal dialysis patients with autosomal dominant polycystic kidney disease

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disorder associated with progressive enlargement of the kidneys and liver. ADPKD patients may require renal volume reduction, especially before renal transplantation. The standard treatment is unilateral nephrectomy. However, surgery incurs a risk of blood transfusion and alloimmunization. Furthermore, when patients are treated with peritoneal dialysis (PD), surgery is associated with an increased risk of temporary or definitive switch to haemodialysis (HD). Unilateral renal arterial embolization can be used as an alternative approach to nephrectomy.

METHODS

We performed a multicentre retrospective study to compare the technique of survival of PD after transcatheter renal artery embolization with that of nephrectomy in an ADPKD population. We included ADPKD patients treated with PD submitted to renal volume reduction by either surgery or arterial embolization. Secondary objectives were to compare the frequency and duration of a temporary switch to HD in both groups and the impact of the procedure on PD adequacy parameters.

RESULTS

More than 700 patient files from 12 centres were screened. Only 37 patients met the inclusion criteria (i.e. treated with PD at the time of renal volume reduction) and were included in the study (21 embolized and 16 nephrectomized). Permanent switch to HD was observed in 6 embolized patients (28.6%) versus 11 nephrectomized patients (68.8%) (P = 0.0001). Renal artery embolization was associated with better technique survival: subdistribution hazard ratio (SHR) 0.29 [95% confidence interval (CI) 0.12-0.75; P = 0.01]. By multivariate analysis, renal volume reduction by embolization and male gender were associated with a decreased risk of switching to HD. After embolization, a decrease in PD adequacy parameters was observed but no embolized patients required temporary HD; the duration of hospitalization was significantly lower [5 days [interquartile range (IQR) 4.0-6.0] in the embolization group versus 8.5 days (IQR 6.0-11.0) in the surgery group.

CONCLUSIONS

Transcatheter renal artery embolization yields better technique survival of PD in ADPKD patients requiring renal volume reduction.

Renal angiomyolipoma with tuberous sclerosis complex: How it differs from sporadic angiomyolipoma in both management and care

Renal angiomyolipoma (AML) is the most common benign tumor of the kidney. It consists of blood vessels, smooth muscle and fat components in varying proportions. AML is divided into the sporadic type and tuberous sclerosis complex (TSC)-associated type. TSC-associated AML develops at a younger age and tends to exhibit a much faster growth rate over time than sporadic AML. AMLs are classified as classic AML, fat-poor AML and epithelioid AML. Epithelioid AML, though rare, shows aggressive behavior leading to distant metastasis and mortality. TSC-associated AML is more likely to have an epithelioid component than sporadic AML. Active surveillance is the suggested management for small AML. Clinical intervention is mainly indicated when there is a substantial risk of rupture. Minimally invasive therapies, including partial nephrectomy, transcatheter arterial embolization, and mammalian target of rapamycin (mTOR) inhibitor treatment are employed for patients who require treatment. An updated algorithm for the management of AML is herein described. According to this algorithm, treatment intervention is recommended for TSC-associated AML >3 cm, even in asymptomatic cases. In cases with asymptomatic sporadic AML >4 cm in size or with an intra-tumoral aneurysm of >5 mm, treatment, including transcatheter arterial embolization or partial nephrectomy, is advised. The major complication of AML is intra-tumoral or retroperitoneal hemorrhage due to rupture that may be serious and life threatening. Thus, correct diagnosis, proper observation, and appropriate treatment are very important in the management of renal AML.

Initial Experience With the Microvascular Plug in Selective Renal Artery Embolization

Purpose:

To evaluate the safety and efficacy of the microvascular plug (MVP) for selective renal artery embolization.

Methods:

Retrospective review was performed on a cohort of 6 patients undergoing renal artery embolization using the MVP between July 2015 and August 2018. Patients’ demographics, indication for embolization, technical details of the embolization procedure, and clinical events were gathered from the patients’ electronic medical records.

Results:

The patients underwent selective renal artery embolization with a MVP for iatrogenic vascular injuries (n = 3), traumatic vascular injuries (n = 2), and for elective embolization of an angiomyolipoma (n = 1), in native kidneys (n = 4) or in renal allografts (n = 2). Immediate occlusion of the feeding artery was achieved with 1 MVP device in 4 patients. In 1 patient, a second MVP was needed, and in another patient, additional 0.018-inch microcoils were used to completely occlude the injured artery. Technical success was achieved in all patients. The volume of the resulting renal infarction was estimated less than 5% of the renal volume. No other procedure-related complications occurred.

Conclusion:

The MVP is a safe and effective device allowing superselective renal artery embolization. Therefore, we recommend the MVP as a valuable embolic in superselective renal artery embolization. Additionally, a single device is sufficient in most cases, potentially reducing the cost, duration, and radiation exposure of the procedure.

Kidney and uro-trauma: WSES-AAST guidelines

Renal and urogenital injuries occur in approximately 10-20% of abdominal trauma in adults and children. Optimal management should take into consideration the anatomic injury, the hemodynamic status, and the associated injuries. The management of urogenital trauma aims to restore homeostasis and normal physiology especially in pediatric patients where non-operative management is considered the gold standard. As with all traumatic conditions, the management of urogenital trauma should be multidisciplinary including urologists, interventional radiologists, and trauma surgeons, as well as emergency and ICU physicians. The aim of this paper is to present the World Society of Emergency Surgery (WSES) and the American Association for the Surgery of Trauma (AAST) kidney and urogenital trauma management guidelines.

Renal Artery Embolization Before Radical Nephrectomy for Complex Renal Tumour: Which are the True Advantages?

Introduction

Renal artery embolization is performed before radical nephrectomy (RN) for renal mass in order to induce preoperative infarction and to facilitate surgical intervention through decrease of intraoperative bleeding. Moreover, in metastatic renal cancer it seems to stimulate tumour-specific antibodies, even if no established benefits in clinical response or survival have been reported. The role of preoperative renal artery embolization (PRAE) in management of renal masses has been often debated and its real benefits are still unclear. Nevertheless, in huge and complex renal masses, which are often characterized by a high and anarchic blood supply and rapid local invasion, radical nephrectomy can be challenging even for skilled surgeons. The aim of this prospective randomized study was to evaluate the effectiveness and safety of PRAE in complex masses by comparing perioperative outcomes of RN with and without PRAE.

Materials and methods

From December 2015 to May 2018 we enrolled prospectively 64 patients who underwent RN for localized (T2a-b) or locally advanced (T3 and T4) or advanced (N+, M+) renal cancers. Patients were divided in two groups. The first group included 30 patients who underwent PRAE; in the second group we enrolled 34 patients who did not undergo RN without PRAE. Perioperative outcomes in terms of operative time, blood loss, transfusion rate and length of hospitalization were evaluated. Statistical analysis was performed using GraphPad Prism 6.0 software.

Results

Median blood loss was 250 ml (50-500) and 400 ml (50-1000) in the first and second group, respectively, with a statistically significant difference (p=0.0066). Median surgical time was 200 min (90-390) and 240 min (130-390) in PRAE and No-PRAE group (p=0.06), respectively. No major complications occurred after embolization. Overall complication rate in Group 1 and 2 was 46.7% (14/30) and 50% (17/34), respectively (p=0.34). No major complications occurred in both groups. The mean follow up was 21,5 months.

Conclusions

Our results prove PRAE to be a safe procedure with low complications rate. To our experience, PRAE seems to be a useful tool in surgical management of a large mass and advanced disease.

[Arterial embolization of polycystic kidneys as an alternative to ergonomic nephrectomy in renal pre-transplantation. Monocentric retrospective study]

PURPOSE

This study aims at providing a retrospective assessment of the decrease in renal volume after renal artery embolization (RAE) among a group of patients with autosomal dominant polycystic renal disease and for whom transplantation, for ergonomic reasons was temporarily advised against.

MATERIAL AND METHODS

Between November 2014 and March 2017, as part of pre-transplantory procedure 15 patients, including 11 men and 4 women benfited from renal embolization (RAE) in a context of preparation for transplant in Lille University Hospital. All of the patients were suffering from autosomal dominant polycystic renal disease (ADPKD) at a severe or terminal stage of renal disease.

RESULTS

The original mean total kidney volume (TKV) was 2550.6 cm³±1771 (1102 cm³; 7310 cm³), the average TKV at 3 months was 1684 cm³±1539 (648 cm³; 6930 cm³) with an average decrease of 33% in the volume (5.2%; 83.9%) (95% confidence interval [0.229-0.436]) (P<0.01) and 1632±1743 (599 cm³; 6758 cm³) at 6 months with an average decrease of 40.7% (7.6%; 64.1%) (IC95% 0.306-0.508) (P<0.01). Among the 15 patients, 13 had their contraindication removed and to date 7 have had successful transplants. One failure due to a very high initial volume (7310cm³) required a secondary nephrectomy. No post-embolization syndrome has been noticed, 2 minor complications occurred (13%) involving a difficult resumption of transit and there was one case of hematuria.

CONCLUSION

ERA procedures must have a place in the ergonomic transplant strategy of patients with ADPKD with a low complication rate and a high efficiency. Nephrectomy indications before transplantation must therefore be reconsidered due to a major postoperative risk. Our results are in line with larger scale studies. Nevertheless, these results need to be confirmed by a large-scale randomized prospective study.

LEVEL OF EVIDENCE

4.

Contemporary management of high-grade renal trauma: Results from the American Association for the Surgery of Trauma Genitourinary Trauma study

BACKGROUND

The rarity of renal trauma limits its study and the strength of evidence-based guidelines. Although management of renal injuries has shifted toward a nonoperative approach, nephrectomy remains the most common intervention for high-grade renal trauma (HGRT). We aimed to describe the contemporary management of HGRT in the United States and also evaluate clinical factors associated with nephrectomy after HGRT.

METHODS

From 2014 to 2017, data on HGRT (American Association for the Surgery of Trauma grades III-V) were collected from 14 participating Level-1 trauma centers. Data were gathered on demographics, injury characteristics, management, and short-term outcomes. Management was classified into three groups-expectant, conservative/minimally invasive, and open operative. Descriptive statistics were used to report management of renal trauma. Univariate and multivariate logistic mixed effect models with clustering by facility were used to look at associations between proposed risk factors and nephrectomy.

RESULTS

A total of 431 adult HGRT were recorded; 79% were male, and mechanism of injury was blunt in 71%. Injuries were graded as III, IV, and V in 236 (55%), 142 (33%), and 53 (12%), respectively. Laparotomy was performed in 169 (39%) patients. Overall, 300 (70%) patients were managed expectantly and 47 (11%) underwent conservative/minimally invasive management. Eighty-four (19%) underwent renal-related open operative management with 55 (67%) of them undergoing nephrectomy. Nephrectomy rates were 15% and 62% for grades IV and V, respectively. Penetrating injuries had significantly higher American Association for the Surgery of Trauma grades and higher rates of nephrectomy. In multivariable analysis, only renal injury grade and penetrating mechanism of injury were significantly associated with undergoing nephrectomy.

CONCLUSION

Expectant and conservative management is currently utilized in 80% of HGRT; however, the rate of nephrectomy remains high. Clinical factors, such as surrogates of hemodynamic instability and metabolic acidosis, are associated with nephrectomy for HGRT; however, higher renal injury grade and penetrating trauma remain the strongest associations.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level III; Therapeutic study, level IV.

Spontaneous Retroperitoneal Hemorrhage - A Rare Presentation of Polyarteritis Nodosa: Role of Angiography in Diagnosis and Management

Spontaneous retroperitoneal hemorrhage (RPH) is a rare but serious complication of polyarteritis nodosa (PAN) and must be considered in patients presenting with RPH as their first presentation. Renal infarctions, liver infarctions, and ruptured microaneurysms are all complications of PAN. We present two cases presenting with abdominal and back pain. The first patient’s abdominal computed tomography (CT) scan revealed fractured right kidney with retroperitoneal pericapsular hematoma and multiple hepatic and splenic infarcts. The digital subtraction angiography (DSA) demonstrated large areas of devascularization of the right kidney and right renal arterial wall irregularity with multifocal areas of stenosis, dilatations, and microaneurysms without active extravasation of IV contrast. She was treated conservatively and started on a pulsed dose of steroids and cyclophosphamide. The second patient’s abdominal CT angiography revealed multiple visceral aneurysms and focal areas of stenosis in branches of celiac axis and superior mesentery artery without active contrast extravasation. The DSA demonstrated multifocal areas of irregularity and narrowing in celiac and intrahepatic arteries as well as a 9 mm pseudoaneurysm in the inferior pancreaticoduodenal artery which was embolized with metallic coils. PAN has a vague clinical presentation and is clinically occult. Patients may be diagnosed while getting investigated for some other causes of abdominal pain. The emergency physician and the radiologist should be aware of the findings and should be able to correlate with pathology to prevent life-threatening complications. Angiography plays a crucial role, not only in diagnosis but also in appropriate management.

Can we predict the existence of extrarenal feeders to renal angiomyolipomas?

OBJECTIVES

To identify factors predicting the presence of extrarenal feeders to renal angiomyolipomas (AMLs) METHODS: This is a retrospective study of 44 patients with 58 renal AMLs embolized in our department. Arteriography obtained during embolization and CT angiography obtained before and after embolization were reviewed to characterize AMLs with and without extrarenal feeders. Tumor characteristics were compared between the two groups. Simple logistic regression and ROC curve analysis were performed. P < 0.05 was considered to be statistically significant.

RESULTS

Of the 58 AMLs reviewed, 29% had extrarenal arteries and 71% did not. AMLs with extrarenal feeders were significantly larger than those without, in terms of volume (median, 368 mL versus 109 mL, p < 0.0002) and the largest diameter (mean, 12.0 cm versus 7.7 cm, p < 0.0001). Patient age, presence of tuberous sclerosis complex or sporadic lymphangioleiomyomatosis, and tumor location did not differ between the groups. The largest diameter and volume had similar predictive values for the presence of extrarenal feeders (AUC, 0.83 versus 0.82, p = 0.673). Extrarenal feeders were present in 0%, 21%, and 79% of the AMLs ≤ 6.5 cm, AMLs 6.6-10.5 cm, and AMLs > 10.5 cm, respectively.

CONCLUSIONS

AML size correlates with the presence of extrarenal feeders, with the largest diameter and volume being significant predictors. AMLs > 10.5 cm had a high chance of extrarenal feeders, making it mandatory to search for feeders to them in order to avoid incomplete embolization; AMLs ≤ 6.5 cm did not have extrarenal feeders, making a search for them unnecessary in these cases.

KEY POINTS

• The presence of extrarenal feeders to renal angiomyolipoma is associated with tumor size, but not with patient age, concomitant disease, or tumor location. • The largest diameter and volume predict the presence of extrarenal feeders to AML, with similar predictive values. • AMLs > 10.5 cm have a high chance (79%) of extrarenal feeders, making it mandatory to search for feeders to them in order to avoid incomplete embolization; AMLs ≤ 6.5 cm do not have extrarenal feeders, making a search for them unnecessary in these cases.