Risk Factors for Severe Bleeding Complications in Percutaneous Renal Biopsy

Bleeding complications after percutaneous kidney biopsies - nationwide experience from Brunei Darussalam

BACKGROUND

Kidney biopsy serves as a valuable method for both diagnosing and monitoring kidney conditions. Various studies have identified several risk factors associated with bleeding complications following the procedure, but these findings have shown inconsistency and variation.

AIM

To investigate the risk of bleeding complications following percutaneous kidney biopsy in Brunei Darussalam. We sought to explore the relevant clinical and pathological risk factors associated with these complications while also considering the findings within the broader international literature context.

METHODS

We conducted a retrospective study of all adult patients who underwent kidney biopsy in Brunei Darussalam from October 2013 to September 2020. The outcomes of interest were post-biopsy bleeding and the need for blood transfusions. Demographics, clinical, laboratory and procedural-related data were collected. Logistic regression analysis was used to identify predictors of outcomes.

RESULTS

A total of 255 kidney biopsies were included, with 11% being performed on transplanted kidneys. The majority of biopsies were done under ultrasound guidance (83.1%), with the rest under computer tomography guidance (16.9%). The most common indications for biopsy were chronic kidney disease of undefined cause (36.1%), nephrotic syndrome (24.3%) and acute kidney injury (11%). Rate of bleeding complication was 6.3% - 2% frank hematuria and 4.3% perinephric hematoma. Blood transfusion was required in 2.8% of patients. No patient lost a kidney or died because of the biopsy. Multivariate logistic regression identified baseline hemoglobin [odds ratio (OR): 4.11; 95% confidence interval (95%CI): 1.12-15.1; P = 0.03 for hemoglobin ≤ 11 g/dL vs. > 11 g/dL) and the presence of microscopic hematuria (OR: 5.24; 95%CI: 1.43-19.1; P = 0.01) as independent risk factors for post-biopsy bleeding. Furthermore, low baseline platelet count was identified as the dominant risk factor for requiring post-biopsy transfusions. Specifically, each 10 109/L decrease in baseline platelet count was associated with an 12% increase risk of needing transfusion (OR: 0.88; 95%CI: 0.79-0.98; P = 0.02).

CONCLUSION

Kidney biopsies were generally well-tolerated. The identified risk factors for bleeding and transfusion can help clinicians to better identify patients who may be at increased risk for these outcomes and to provide appropriate monitoring and management.

Weeping sponge kidney: an unusual phenomenon that should be considered in cases of severe renal haemorrhage

AIM

To describe the clinical presentation, imaging evaluation, endovascular management, and outcomes of multifocal renal capsular haemorrhage, "weeping sponge kidney", and to identify associated risk factors and the pathophysiological mechanism behind this condition.

MATERIALS AND METHODS

This is a case series in which clinical information for each of the cases was collected retrospectively from electronic patient notes as well as the radiology information and picture archiving and communication systems.

RESULTS

Four consecutive cases were included in the series. All of the cases were treated successfully with embolisation. Three of the four patients had chronic renal failure with renal atrophy, which are patient factors that appear to be associated with multifocal renal capsular haemorrhage. Based on the procedural findings and the published literature, a pathophysiological mechanism is described to explain this condition and the relevance of the collateral arterial supply to the kidney in such cases is discussed.

CONCLUSION

Small subcapsular haematomas are usually self-limiting but in patients with renal failure, there may be an increased risk of developing a weeping sponge kidney, which can be life-threatening. The endovascular treatment for multifocal haemorrhage differs from that for a single bleeding point, especially if preservation of renal function is not a priority.

Predictive factors of selective transarterial embolization failure in acute renal bleeding: a single-center experience

PURPOSE

Transarterial embolization of renal artery branches (RTE) is a minimally invasive procedure commonly performed in life-threatening renal bleeding of different etiologies. Despite the widespread use of RTE, no consensus guidelines are currently available. Our aim was to investigate clinical and technical efficacy and to identify potential predictors for clinical failure of this procedure.

METHODS

All the RTE procedures performed in our Interventional Radiology unit in last 10 years were retrospectively collected and analyzed. All selected patients underwent both pre-procedural computed tomography angiography (CTA) and post-procedural CTA within 30 days. Clinical success was considered as primary endpoint. Demographic, laboratory, and diagnostic findings predictive of clinical failure of RTE were identified.

RESULTS

Over a total of 51 patients enrolled, 27 (53%) were females and 33 (64.7%) had a renal bleeding of iatrogenic origin. Technical and clinical success was 100% and 80.4%, respectively. Hematoma volumes > 258.5 cm3 measured at CTA, higher pre- and post-procedural serum creatinine (Scr) levels, an increase in Scr value > 0.135 mg/dl after the procedure, a worse post-procedural estimated glomerular filtration rate (eGFR), a post-procedural reduction of eGFR < 3.350 ml/min, and a post-procedural reduction of platelet count (PLT) > 46.50 × 103/mmc showed a significantly higher rate of clinical failure.

CONCLUSION

RTE is a safe and effective procedure in the management of acute renal bleeding of various origins. Hematoma volume, Scr, PLT, and eGFR values were found to be predictive factors of poor clinical outcome and should be closely monitored.

Research Letter-Outcomes of Outpatient Native Kidney Biopsies at the McGill University Health Center: A Quality Assurance Audit

Background

Percutaneous kidney biopsies are essential for diagnosis and management of kidney diseases. However, post-procedural bleeding is a significant risk associated with biopsies. At the McGill University Health Center, the 2 main hospitals, the Royal Victoria Hospital and the Montreal General Hospital, have different observation protocols for outpatient native kidney biopsies. Currently, patients are admitted for a 24-hour inpatient observation at the Montreal General Hospital, whereas patients biopsied at the Royal Victoria Hospital are discharged after 6 to 8 hours of observation at the end of the day. Most Canadian centers do not admit patients for an overnight observation, and it was unclear why this practice continued at the Montreal General Hospital.

Objective

Our objective was to determine the incidence of complications post-renal biopsy over the past 5 years at both hospital sites, and compare them to each other, as well as to established rates in the available literature.

Design

This assessment was designed as a quality assurance audit.

Setting

This audit was conducted from a local registry of renal biopsies performed at the McGill University Health Center between January 2015 to January 2020.

Patients

We included all adult patients (between the ages 18 and 80) with outpatient native kidney biopsies performed at the McGill University Health Center between 2015 and 2020.

Measurements

We collected the included patients' baseline demographics and risk factors at the time of biopsy, including age, BMI, creatinine, estimated glomerular filtration rate, pre- and post-biopsy hemoglobin, platelet, urea, coagulation profile, blood pressure, kidney side/size as well as needle size, and number of passes made.

Methods

We compared the incidence of both minor and major bleeding complications at the Montreal General and the Royal Victoria Hospital. Variables that were measured included hemoglobin before and after biopsy, incidence of minor bleeding complications (defined by hematomas and gross hematuria), and incidence of major complications (defined by post-biopsy bleeding requiring either transfusions or another procedure to stop the bleeding), as well as the incidence of admissions post-biopsy.

Results

The incidence of major complications was 2.87% over 5 years (5/174 patients), which is comparable with that reported in the literature. Our transfusion incidence was 1.72% (3/174 patients) and our embolization incidence was 2.3% (4/174 patients) over the 5 study years. Our total number of major events was low and the patients who had major events had significant risk factors for bleeding. All events occurred within 6 hours of observation.

Limitations

This was a retrospective study with a low event number. Additionally, since the events included only those recorded at the McGill University Health Center, it is possible that the events of interest may have occurred at other hospital sites without the author's knowledge.

Conclusions

Based on the results of this audit, all major bleeding events occurred within 6 hours of a percutaneous kidney biopsy, suggesting that patients should be monitored for 6 to 8 hours following biopsy. The next step after this quality assurance audit is a quality improvement project and a cost-effectiveness analysis to assess whether post-biopsy practices should be amended at the McGill University Health Center.

Development and validation of a nomogram for blood transfusion during intracranial aneurysm clamping surgery: a retrospective analysis

PURPOSE

Intraoperative blood transfusion is associated with adverse events. We aimed to establish a machine learning model to predict the probability of intraoperative blood transfusion during intracranial aneurysm surgery.

METHODS

Patients, who underwent intracranial aneurysm surgery in our hospital between January 2019 and December 2021 were enrolled. Four machine learning models were benchmarked and the best learning model was used to establish the nomogram, before conducting a discriminative assessment.

RESULTS

A total of 375 patients were included for analysis in this model, among whom 108 received an intraoperative blood transfusion during the intracranial aneurysm surgery. The least absolute shrinkage selection operator identified six preoperative relative factors: hemoglobin, platelet, D-dimer, sex, white blood cell, and aneurysm rupture before surgery. Performance evaluation of the classification error demonstrated the following: K-nearest neighbor, 0.2903; logistic regression, 0.2290; ranger, 0.2518; and extremely gradient boosting model, 0.2632. A nomogram based on a logistic regression algorithm was established using the above six parameters. The AUC values of the nomogram were 0.828 (0.775, 0.881) and 0.796 (0.710, 0.882) in the development and validation groups, respectively.

CONCLUSIONS

Machine learning algorithms present a good performance evaluation of intraoperative blood transfusion. The nomogram established using a logistic regression algorithm showed a good discriminative ability to predict intraoperative blood transfusion during aneurysm surgery.

The impact of blood pressure on the risk of postbiopsy bleeding during the whole procedure of percutaneous kidney biopsy

PURPOSE

To investigate whether BP is related to postbiopsy bleeding in patients undergoing native percutaneous kidney biopsy (PKB) and to evaluate the dynamic changes in blood pressure (BP) pre- and post-kidney biopsy.

METHODS

A retrospective cross-sectional study was conducted. The whole-procedural systolic (SBP) and diastolic (DBP) BP for patients undergoing ultrasound-guided native PKB from October 2017 to December 2020 were recorded in the study. Propensity score matching was used to minimize selection bias. SBP and DBP were analyzed as the main risk factors for bleeding complications. Receiver operating characteristic (ROC) curves were employed to explore the optimal BP thresholds to differentiate between bleeding and nonbleeding. The rates of major bleeding complications were analyzed according to BP thresholds through logistic analysis.

RESULTS

Of 1146 biopsies, 432 (37.7%) patients suffered from postbiopsy bleeding, 88 (7.7%) patients had major bleeding complications, and 344 (30.0%) patients had minor bleeding complications. In the original data, for patients with SBP ≥ 160 mmHg before PKB, the rate of major bleeding complications was 17.6% (7.5% for SBP < 160 mmHg), and the rate of major bleeding complications was 19.0% in patients with DBP ≥ 100 mmHg (7.5% for DBP < 100 mmHg). For patients with DBP ≥ 85 mmHg to 100 mmHg after PKB, the rate of major bleeding complications ranged from 9.5 to 17.5%. The rate of major bleeding complications was lower (6.6-7.3%) in patients with DBP < 100 mmHg to 85 mmHg.

CONCLUSION

Patients who have high-level BP during the native PKB perioperative period are at higher risk for postbiopsy bleeding. High-level BP here does not refer to traditional hypertension according to the guidelines for the diagnosis and treatment of hypertension, but rather BP above a certain threshold related to bleeding risk.

Development and Evaluation of a Novel Radiotracer 125I-rIL-27 to Monitor Allotransplant Rejection by Specifically Targeting IL-27Rα

Noninvasive monitoring of allograft rejection is beneficial for the prognosis of patients with organ transplantation. Recently, IL-27/IL-27Rα was proved in close relation with inflammatory diseases, and 125I-anti-IL-27Rα mAb our group developed demonstrated high accumulation in the rejection of the allograft. However, antibody imaging has limitations in the imaging background due to its large molecular weight. Therefore, we developed a novel radiotracer (iodine-125-labeled recombinant IL-27) to evaluate the advantage in the targeting and imaging of allograft rejection. In vitro specific binding of 125I-rIL-27 was determined by saturation and competitive assay. Blood clearance, biodistribution, phosphor autoradioimaging, and IL-27Rα expression were studied on day 10 after transplantation (top period of allorejection). Our results indicated that 125I-rIL-27 could bind with IL-27Rα specifically and selectively in vitro. The blood clearance assay demonstrated fast blood clearance with 13.20 μl/h of 125I-rIL-27 staying in the blood after 24 h. The whole-body phosphor autoradiography and biodistribution assay indicated a higher specific uptake of 125I-rIL-27 and a clear radioimage in allograft than in syngraft at 24 h, while a similar result was obtained at 48 h in the group of 125I-anti-IL-27Rα mAb injection. Meanwhile, a higher expression of IL-27Rα was found in the allograft by Western blot. The accumulation of radioactivity of 125I-rIL-27 was highly correlated with the expression of IL-27Rα in the allograft. In conclusion, 125I-rIL-27 could be a promising probe for acutely monitoring allograft rejection with high specific binding towards IL-27Rα on allograft and low imaging background.

Predictors of Major Hemorrhage After Spleen Core Biopsy in Cancer Patients

In this retrospective study, 232 spleen biopsies from 218 patients with cancer were assessed. Biopsies resulting in hemorrhage requiring hospitalization, transfusion, or other interventions were compared with those that did not. The maximization of the Youden index helped determine the optimal systolic blood pressure (SBP) and platelet count thresholds. There were 15 (7%) major hemorrhages among 211 core biopsies. A multivariate logistic regression model showed that higher SBP, lower platelet count, and the lack of ultrasound guidance were independently associated with major hemorrhage (P < .05). The optimal SBP cutoff was 140 mm Hg, and the platelet count cutoff was 120,000 platelets/μL. In conclusion, the high major hemorrhage rate of 7% among percutaneous core spleen biopsies in patients with cancer may be mitigated by controlling SBP to <140 mm Hg and avoiding biopsy in patients with thrombocytopenia.

Two-Week Protocol Biopsy in Renal Allograft: Feasibility, Safety, and Outcomes

Background: Protocol biopsy in renal allograft helps to early detect subclinical rejection (SCR) in patients who have no abnormal clinical and laboratory findings. Still, there are rare reports about the techniques and outcomes of two-week protocol biopsy. The aim of this study was to assess two-week protocol biopsy regarding the technical feasibility, procedure safety, and clinical outcomes. Methods: A total of 894 protocol biopsies were performed in adult recipients between 2012 and 2019. Two-week and one-year protocol biopsies were guided with ultrasound in 842 and 399 patients by one of four radiologists with wide range of biopsy experience, respectively. These protocol biopsies were compared in terms of feasibility and safety. Standard references were clinico-laboratory findings and biopsy examinations. Results: The median period of two-week and one-year protocol biopsies were 12 days (10–20 days) and 383 days (302–420 days), respectively. All protocol biopsies were technically successful and there was no difference between radiologists regarding technical success and complications (p = 0.453). Major complication (Clavien–Dindo grading II–IV) rates of two-week and one-year protocol biopsies were 0.3% (3/842) and 0.2% (1/399), respectively (p = 1.000). However, univariate analysis demonstrated that platelet count < 100 K/mL and blood urea nitrogen ≥ 40 mg/dL were associated with major complications in two-week protocol biopsy. The SCRs of these protocol biopsies were 15.4% (130/842) and 33.6% (134/399), respectively (p < 0.001). Conclusion: Two-week protocol biopsy is technically feasible and safe. It contributes to early detecting a substantial number of SCRs. Prior to the biopsy, platelet count and blood urea nitrogen should be carefully checked to predict major complications.

No effect of desmopressin administration before kidney biopsy on the risk of major post-biopsy bleeding

BACKGROUND/AIMS

The most important complication of kidney biopsy is bleeding, and it is unclear whether desmopressin is effective in preventing it. Thus, the study was conducted to compare post-biopsy bleeding with or without desmopressin prescription prior to percutaneous kidney biopsy.

METHODS

In this single-centered, retrospective, and observational study, 3,018 adult patients who underwent kidney biopsy between January 1, 2003 and March 31, 2019 at our institute were recruited. Of these, 776 patients received desmopressin. To compare the differences in major bleeding events between patients administered and not administered with desmopressin, propensity score matching was performed.

RESULTS

Before propensity score (PS) matching, it was observed that patients in the desmopressin group were significantly older (p<0.001) and had a higher blood pressure (p<0.001), higher serum creatinine (p<0.001), lower hemoglobin levels (p<0.001), and lower platelet counts (p=0.001) than those in the no-desmopressin group. Furthermore, the incidence of renal artery embolization was not significantly different between the two groups (p=0.077); however, blood transfusions occurred significantly more frequently in the desmopressin group (p<0.001). A comparison of the two groups after PS matching did not reveal any differences in the incidence of renal artery embolization (p=0.341), blood transfusion (p=0.579), and total major bleeding events (p=0.442). Furthermore, there was no difference in the incidence of perinephric hematoma on computed tomography or ultrasound (p=0.120).

CONCLUSIONS

We do not recommend desmopressin administration before kidney biopsy.

Acute Brachial Arterial Embolic Occlusion Following Anticoagulant Discontinuation in a Renal Biopsy of a Nephrotic Syndrome Patient

A 73-year-old woman with atrial fibrillation treated with rivaroxaban was hospitalized for nephrotic syndrome. After discontinuation of rivaroxaban to lower the risk of hemorrhagic events, a renal biopsy was performed. Rivaroxaban was scheduled to resume a week after the biopsy to prevent renal hemorrhaging. However, she developed acute brachial arterial embolic occlusion and mural thrombosis in the abdominal aorta before resuming rivaroxaban. If immune-mediated renal diseases are suspected in anticoagulated patients at a risk of thrombotic events, physicians should consider initiating glucocorticoid therapy without a renal biopsy in order to avoid hemorrhagic and thrombotic events.

Clinical and Pathological Features of Renal Presentations in Polycythemia Vera

BACKGROUND

Polycythemia vera (PV) is a common type of Philadelphia chromosome-negative chronic myeloproliferative disorder. PV-associated kidney disease is rarely reported and remains poorly understood. It has been observed that chronic kidney disease could be a risk factor for poor prognosis in PV.

METHODS

We retrospectively analyzed the clinicopathological features of renal presentations in eight patients with confirmed PV-associated kidney disease.

RESULTS

The eight patients were 6 males and 2 females, with a mean age of 46.4±16.8 years. Six patients had a history of PV, with a duration range 0.5-16 years. The other two patients were newly diagnosed with PV simultaneously with glomerular disease. Seven patients conducted a JAK2 V617F mutation test, with a positive result in five. Proteinuria and renal dysfunction were the patients' main complaints, with only one having nephrotic syndrome and three having microscopic hematuria. The level of proteinuria ranged from 0.52-10.96 g/day. Three patients had advanced chronic kidney disease (CKD), two in stage 3b and one in stage 4, but only one patient had anemia. Three patients had monoclonal immunoglobulinemia, one patient with immunoglobulin (Ig) G kappa plus light chain lambda, one patient with IgG kappa, and one patient with IgG lambda. Five patients underwent a renal biopsy. The pathological diagnosis was IgA nephropathy in three, non-IgA mesangial proliferative glomerulopathy in one, and glomerular hypertrophy with ischemic renal injury in one patient. Glomerular ischemia, ischemic shrinkage, focal segmental sclerosis, and glomerulomegaly were common pathological features. Glomerular crescents and endocapillary proliferation were also observed. All patients were administered hydroxyurea, and seven were administered renin-angiotensin system inhibitors. During follow-up, one patient with uncontrolled PV developed secondary myelofibrosis and died, three patients were lost to follow-up, and four patients remained alive with CKD.

CONCLUSIONS

Patients with untreated or uncontrolled PV could have massive proteinuria and advanced CKD, pathologically showing ischemic, sclerosing glomerular lesions with hypercellurity, glomerular crescents and endocapillary proliferation. IgA nephropathy was most commonly diagnosed. These findings deserve attention because early screening and effective control of PV may benefit the long-term kidney prognosis.

Risk factors for biopsy complications in initial versus subsequent biopsies in native and transplant kidneys

BACKGROUND

Few studies exist about risk factors for complications in subsequent biopsies.

PURPOSE

To explore risk factors for complications in initial versus subsequent biopsies in native and transplant kidneys, which may predict biopsy complications.

MATERIAL AND METHODS

In a multicenter study, 2830 native kidney biopsies (4.3% subsequent) were analyzed for major complications (1251 of these were also analyzed for minor) and 667 transplant kidney biopsies (29% subsequent) were analyzed for major and minor complications. No death or nephrectomy were described. Fisher's exact test, Student's t-test, chi-square analyses, and univariate and multiple binary logistic regression analyses were employed; P < 0.05 was considered significant.

RESULTS

In initial native kidney biopsies, the frequency of major complications was higher in women compared to men (odds ratio 1.6, 95% confidence interval 1.1-2.2), in younger patients (50 vs. 54 years, P = 0.007), and in patients with lower weight (78 vs. 82 kg, P = 0.005). In subsequent native kidney biopsies, patients with major complications had a higher systolic blood pressure (145 vs. 132 mmHg, P = 0.03). In initial transplant kidney biopsies, biopsies with major complications had less glomeruli in the biopsy (17 vs. 24, P = 0.046). In subsequent transplant kidney biopsies, patients with major complications had a higher mean arterial pressure (112 vs. 98 mmHg, P = 0.002). In subsequent native kidney biopsies, there was a higher number of SLE-nephritis (12% vs. 4.6%, P = 0.001) compared to initial biopsies.

CONCLUSION

The different types of risk factors for complications in initial versus subsequent renal biopsies could be important for the clinicians to improve patients' safety.

Evaluation of percutaneous renal biopsy complications based on outcomes and indicators of the Nursing Outcomes Classification

Objective:

to evaluate the complications of percutaneous renal biopsy based on outcomes and clinical indicators of the Nursing Outcomes Classification.

Method:

a prospective longitudinal study. The sample consisted of 13 patients submitted to percutaneous renal biopsy, with 65 evaluations. The patients were evaluated in five moments in the 24 hours after the procedure, using an instrument developed by the researchers based on five outcomes (Blood coagulation, Circulation status, Blood loss severity, Pain level, Comfort status: Physical) and 11 indicators. The Generalized Estimation Equation Test was used to compare the scores of the indicators. The project was approved by the institutional ethics committee.

Results:

in the 65 evaluations, a statistically significant difference was identified in the reduction of the scores of the following nursing outcomes: Blood coagulation, “hematuria” indicator; Circulation status, in the “systolic blood pressure and diastolic blood pressure” indicators and Comfort status: physical, in the “physical well-being” indicator.

Conclusion:

the evaluated patients did not show major complications. The clinical indicators signaled changes in circulation status, with reduced blood pressure, as well as in blood clotting observed by hematuria, but without hemodynamic instability. The comfort status was affected by the rest time after the procedure.

Bleeding Complications of Percutaneous Kidney Biopsy: Does Gender Matter?

The incidence of bleeding complications after percutaneous kidney biopsies is low.Female sex may be associated with a greater risk for bleeding complications after percutaneous kidney biopsies.This association and the plausible mechanisms require further evaluation in prospective study.

No effect of desmopressin administration before kidney biopsy on the risk of major post-biopsy bleeding

BACKGROUND/AIMS

The most important complication of kidney biopsy is bleeding, and it is unclear whether desmopressin is effective in preventing it. Thus, the study was conducted to compare post-biopsy bleeding with or without desmopressin prescription prior to percutaneous kidney biopsy.

METHODS

In this single-centered, retrospective, and observational study, 3,018 adult patients who underwent kidney biopsy between January 1, 2003 and March 31, 2019 at our institute were recruited. Of these, 776 patients received desmopressin. To compare the differences in major bleeding events between patients administered and not administered with desmopressin, propensity score matching was performed.

RESULTS

Before propensity score (PS) matching, it was observed that patients in the desmopressin group were significantly older (p<0.001) and had a higher blood pressure (p<0.001), higher serum creatinine (p<0.001), lower hemoglobin levels (p<0.001), and lower platelet counts (p=0.001) than those in the no-desmopressin group. Furthermore, the incidence of renal artery embolization was not significantly different between the two groups (p=0.077); however, blood transfusions occurred significantly more frequently in the desmopressin group (p<0.001). A comparison of the two groups after PS matching did not reveal any differences in the incidence of renal artery embolization (p=0.341), blood transfusion (p=0.579), and total major bleeding events (p=0.442). Furthermore, there was no difference in the incidence of perinephric hematoma on computed tomography or ultrasound (p=0.120).

CONCLUSIONS

We do not recommend desmopressin administration before kidney biopsy.

Spectrum of pediatricbiopsy-proven renal diseases: A single center experience

Glomerular diseases are considered to be a significant cause of chronic kidney disease. Kidney biopsy continues to be an essential diagnostic tool. We review the renal biopsies which were done on children below the age of 14 years in the past 10 years (from January 2008 to September 2018) in a single tertiary pediatric hospital in Saudi Arabia to determine the patterns of renal disease among Saudi children as well-correlating clinical presentation with histopathological diagnosis. A total of 203 pediatric kidney biopsies were performed. The mean age was 7.3 ± 3.9 years (3 months to 14 years). There were 105 males and 98 females. The most frequent indication for renal biopsy was nephrotic syndrome in 58.9% of patients, followed by acute glomerulo- nephritis in 20.8%. Other indications included significant proteinuria, persistent microscopic hematuria, acute kidney injury of uncertain etiology, in the remaining 20% of biopsies. Clinical diagnosis was consistent with histopathological diagnosis in 92% of the cases. Minimal change disease was the most common cause of primary glomerular diseases in 37.4%, followed by focal segmental glomerulosclerosis in 20.2%. Lupus nephritis represents the most common cause of the secondary renal disease (8.4%). Complications of kidney biopsy were observed in only 16.3% of patients, of whom 9.9% had perirenal hematomas and 6.4% of the patients developed either microscopic hematuria or macroscopic hematuria.

A non-invasive differential diagnostic model for light chain cast nephropathy in newly diagnosed multiple myeloma patients with renal involvement: a multicenter study

OBJECTIVE

Light chain cast nephropathy is the most common form of renal lesion in multiple myeloma. Kidney impairment caused by light chain cast nephropathy can be reversed and survival can be improved if early diagnosis is available. It is thus of imperative importance to develop a non-invasive method to diagnose light chain cast nephropathy once the kidney biopsy is not always applicable.

METHODS

We consecutively screened newly diagnosed multiple myeloma patients with kidney biopsies from 4 centers in China. Kidney pathologies were reviewed and clinical presentations were recorded. Then a diagnostic model was established by logistic regression and the predictive values were assessed.

RESULTS

Between 1 June 1999 and 30 June 2019, a kidney biopsy was performed in 94 patients with newly diagnosed multiple myeloma, and light chain cast nephropathy was the most common pattern, seen in 52% of biopsied patients. The diagnostic model was established by multivariate logistic regression analysis as P(z) = 1/(1 + e^-z) and z = - 0.093 Hemoglobin (g/L) + 0.421 Serum albumin (g/L) + 3.463 Acute kidney injury (0/1) - 9.207 High-density lipoprotein (mmol/L). If P(z) ≥ 0.55, the diagnosis pointed to light chain cast nephropathy; if P(z) < 0.55, the diagnosis favored non-light chain cast nephropathy. The area under the receiver operating characteristic curves was 0.981 (95% CI 0.959, 1.000). The model had a sensitivity of 93.9%, a specificity of 95.6%, a positive predictive value of 96.0%, a negative predictive value of 94.0%, and a total consistency of 95.0%.

CONCLUSION

We built a novel, non-invasive diagnostic model through a multicenter study, which may be helpful in the diagnosis of light chain cast nephropathy in newly diagnosed multiple myeloma patients.

Differential expression of transfer RNA-derived small RNAs in IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) is one of the most common forms of primary glomerulonephritis. Recent studies have indicated that small noncoding RNAs, such as tRNA-derived small RNAs (tsRNAs), might be novel biomarkers for glomerulonephritis. We therefore investigated the potential roles and possible functions of the tsRNAs in IgAN.

METHOD

Peripheral blood mononuclear cells (PBMCs) were extracted from blood samples of the patients with IgAN and healthy control groups. The expression profiles of tsRNAs were assessed by small RNA sequencing (RNA-Seq) in PBMCs of the IgAN and control groups. Dysregulated tsRNAs were selected for validation by quantitative real-time polymerase chain reaction (qRT-PCR). Target gene prediction and enrichment were performed by bioinformatics analysis.

RESULTS

The results revealed that 143 significantly upregulated and 202 significantly downregulated tsRNAs were differentially altered in the IgAN group compared with the control group. Five upregulated tsRNAs (tRF-Val-AAC-007, tRF-Ala-AGC-063, tRF-Gln-CTG-010, tRF-Tyr-GTA-011 and tRF-Thr-AGT-007) and 3 downregulated tsRNAs (tiRNA-Val-TAC-004, tRF-Gly-CCC-005 and tRF-His-GTG-006) were selected for validation by qRT-PCR; the results were consistent with the sequencing data. Gene Ontology (GO) analysis revealed that the target genes predicted by upregulated tsRNAs were mostly enriched in "nucleic acid metabolic process,' "intracellular part,' and "ion binding,' whereas the target genes predicted by downregulated tsRNAs were mostly enriched in "regulation of cellular component organization,' "membrane-bound organelle,' and "ion binding.' Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the target genes predicted by upregulated tsRNAs were mostly enriched in "herpes simplex virus 1 infection,' whereas the target genes predicted by downregulated tsRNAs were mostly enriched in "circadian rhythm CONCLUSIONS:: The present study confirmed the differential expression of tsRNAs in patients with IgAN, and these dysregulated tsRNAs might be novel potential targets for the diagnosis and treatment of IgAN.

A Systematic Review of Complications Associated With Percutaneous Native Kidney Biopsies in Adults in Low- and Middle-Income Countries

Introduction

Kidney biopsy is an important tool for making diagnoses and for assessing the drug treatment requirements and disease prognosis in the management of kidney diseases. There are variations in the rate of complications associated with kidney biopsies across countries, and this depends on various clinical and technical factors. The aim of this study is to report on complications associated with kidney biopsy performed in low- and middle-income countries.

Methods

Two reviewers searched studies in MEDLINE, Embase, Cochrane Reviews, and African Journals Online. A random effects meta-analysis method was used to pool estimates of complications.

Results

We identified 39 studies reporting on 19,500 kidney biopsies with overall complications (major + minor) rate of 14.9% (95% confidence interval = 11.4%–18.7%). Fewer complications were reported in biopsies performed with real-time ultrasound scans compared to those pre-marked using ultrasound or blind procedures (12.4% vs. 14.9% vs. 24.5%; P = 0.037), respectively. Complications, albeit lower for procedures performed with automated needles (13.3%), were not significantly different from those performed with nonautomated needles (17.3%; P = 0.588). Major complications included macroscopic hematuria (1.48%), nephrectomy (0.04%), blood loss requiring red cell transfusion (0.24%), angiographic intervention (0.22%), and death (0.01%).

Conclusion

Complications associated with kidney biopsy in low- and middle-income countries are low, are comparable to those in other settings, and occur more sparingly when real-time ultrasound techniques or automated kidney biopsy needles are used. This suggests the need to expand the use of this procedure to improve diagnosis of kidney pathologies and choice of therapy when indicated.

Acute Kidney Disease Increases the Risk of Post-Kidney Biopsy Bleeding Complications

INTRODUCTION

Kidney biopsy, providing the insightful information for most kidney diseases, is an invasive diagnostic tool with certain risks ranging from the least severe macroscopic hematuria to the most severe life-threatening bleeding necessitating renal artery embolization. We aimed to compare the postbiopsy bleeding complications between 2 common methods and to further explore the risk factors of bleeding complications in patients using the negative pressure suction puncture (NPS) method.

METHODS

We retrospectively collected the data from percutaneous native kidney biopsies in 2016. The clinical, laboratory tests, pathological findings, and the occurrence of bleeding complications following kidney biopsy were analyzed. The kidney biopsy was performed in our center by experienced nephrologists with 2 different methods, namely, NPS method and real-time ultrasound-guided needle (RTU) method. We compared rates of complications between 2 methods and evaluated univariate and multivariate association of risk factors with bleeding complications in the NPS group.

RESULTS

626 kidney biopsies were performed between January 2016 and December 2016. There were 83.2% (521/626) participants in the NPS group and 16.8% (105/626) in the RTU group. There were more participants in the RTU group needing >1 needle pass during biopsy than those in the NPS group (61.0 vs. 14.7%, p < 0.001). Acute kidney disease (AKD) occurred before the procedure of kidney biopsy accounted for 13.8% (72/521) in the NPS group and 1.9% (2/105) in the RTU group. The renal pathological findings revealed higher number of glomeruli in the NPS group than in the RTU group (26.8 ± 13.0 vs. 17.2 ± 8.6, p < 0.001). The incidence of bleeding complications in the NPS group was lower than that in the RTU group (9.2 vs. 21.9%, p < 0.01). Logistic multivariate regression showed that AKD was independently associated with bleeding complications after kidney biopsy in the NPS group.

CONCLUSION

Regarding the bleeding risk, there was noninferiority of NPS over RTU. AKD contributes to higher risks of bleeding complications after kidney biopsy.

Differential expression of peptides serves as an indicator of IgA nephropathy in pediatric patients

Peptide profiles change significantly with aging and peptide biomarkers discovered in adult patients may not be suitable for the evaluation of pediatric patients. The present study was designed to explore alterations in the serum peptidome profile of pediatric patients with IgA nephropathy (IgAN). A total of 17 children diagnosed with IgAN were recruited as the experimental group, 11 sex-matched healthy children were recruited as a healthy control group and 18 sex-matched children with other glomerular diseases were recruited as a disease control group. Serum peptides of each subject were enriched and analyzed by liquid chromatography with tandem mass spectrometry and the subsequently identified IgAN-specific peptides were evaluated using Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analysis. Subsequently, the function of the IgAN-specific peptides was predicted via sequence comparison with other known functional bioactive peptides. A total of 123 peptides with a fold change >2 (P<0.05) and 48 peptides with a fold change >5 (P<0.05) were identified to be differentially expressed between the pediatric IgAN group and the two other groups. Consequently, two putative peptides that may have bioactive effects in the pathogenesis of IgAN in pediatric patients were identified. The serum peptidome profile of pediatric patients with IgAN was significantly different from the disease control group and the healthy control group. These differentially expressed peptides may serve as biomarkers for the minimally invasive diagnosis of pediatric patients with IgAN. Additionally, the potential bioactive peptides specifically expressed in pediatric IgAN patients that were identified in this study may lay a foundation for exploring new therapies for IgAN, such as the creation of novel peptide drugs.

Associations between the concentrations of CD68, TGF-β1, renal injury index and prognosis in glomerular diseases

The present study aimed to investigate the association between the concentrations of CD68, TGF-β1, renal injury index and prognosis in glomerular diseases. Altogether 218 patients with glomerular diseases admitted to Weifang People's Hospital from January, 2014 to March, 2017 were used as the study group. A total of 100 healthy individuals who visited Weifang People's Hospital for a physical examination during the same time period were used as the control group. The levels of CD68 in peripheral blood obtained from the 2 groups of subjects were detected by flow cytometry, and the expression of TGF-β1 in serum was detected by enzyme-linked immunosorbent assay (ELISA). The concentrations of CD68 and TGF-β1 between the 2 groups were compared. The correlation between the concentrations of CD68, TGF-β1 and renal injury indexes in the study group was analyzed, as well as prognostic significance. The diagnostic value of CD68 and TGF-β1 in patients with glomerular disease was analyzed using a ROC curve, and the recovery of the patients was observed. The serum concentrations of CD68 and TGF-β1 in the study group were higher than those in the control group (P<0.05). The concentrations of CD68 and TGF-β1 in the study group positively correlated with the renal injury indexes, such as blood urea nitrogen (BUN), serum creatinine (SCR), uric acid (UA) and the 24-h urinary protein quantity (P<0.05). ROC curve analysis revealed that the area under the curve of CD68 and TGF-β1 as regards the diagnostic value in patients with glomerular disease was 0.808 and 0.738, respectively, while the area under the combined detection curve was 0.866. Multivariate unconditional logistic regression analysis revealed that the clinical classification and the concentrations of CD68 and TGF-β1 were independent prognostic factors in the study group. On the whole, the findings of the present study demonstrate that clinical classification, and the CD68 and TGF-β1 concentrations are independent prognostic factors for patients with glomerular disease. CD68 and TGF-β1 have certain value in the diagnosis of glomerular diseases, and may thus be used as predictors of the diagnosis and recovery of glomerular disease.

Kidney biopsy in the elderly: diagnostic adequacy and yield

PURPOSE

The number of kidney biopsies (KB) performed in elderly patients has been increasing. Safety and usefulness of elderly KB have been well established, whereas much less is known about diagnostic adequacy and yield in this patient population.

METHODS

We performed a retrospective study of KBs in 428 patients from April 2015 to December 2017 at an academic institution. We compared KB from 50 patients aged over 64 (elderly) with KB from 378 patients aged between 18 and 64.

RESULTS

Gender ratio, body mass index, systolic and diastolic BP, creatinine values, incidences of AKI at the time of biopsy, INR/aptt values, and platelets were similar between the two groups. eGFR and number of transplant biopsies were lower in the elderly biopsy group. The glomerular yield was similar between the two groups (22 ± 14 vs. 22 ± 13, p = 0.869). The likelihood of obtaining more than ten glomeruli was 87% and 88%, respectively, without a significant difference. Inadequate samples were encountered in 6% of the elderly and 5.6% of the non-elderly KB, again without a significant difference. Samples taken by nephrologist had higher glomerular yield for both groups (25 ± 13 vs. 18 ± 12 overall, 26 ± 14 vs. 18 ± 14 for elderly, p < 0.001 both). Inadequate biopsies were lower in the nephrologist group when all patients were considered (3% vs. 9%, p = 0.025). Results were numerically similar for the elderly patients, but the difference was not statistically significant (2% vs. 8%, p = 0.322). No deaths occurred in both arms. Minor complications were not different for each group (4.5% vs. 4%). There were no major complications in elderly patients. However, the difference did not reach statistical significance.

CONCLUSION

The world is aging, leading to an increased number of KB in older patients. KB in the elderly is a safe, effective, and an indispensable tool for the nephrologist. This study suggests there is no need to fear lower diagnostic adequacy in the decision making of a KB for an elderly patient.

A Color Flow Tract in Ultrasound-Guided Random Renal Core Biopsy Predicts Complications

OBJECTIVES

To determine patient and procedural risk factors for major complications in ultrasound (US)-guided random renal core biopsy.

METHODS

Random renal biopsies performed by radiologists in the US department at a single institution between 2014 and 2018 were retrospectively reviewed. The patient's age, sex, race, and estimated glomerular filtration rate (eGFR) were recorded. The biopsy approach, needle gauge, length of cores, number of throws, and presence of a color flow tract were recorded. Outcome data included minor and major complications. Associations between variables were tested with χ² analyses and univariable/multivariable logistic regression models.

RESULTS

A total of 231 biopsies (167 native and 64 allografts) were reviewed. There was no significant difference in the sex, age, race, or eGFR between native and allograft groups. The overall rate for any complication was 18.2%, with a 4.3% rate of major complications, which was significantly greater in native compared to allograft biopsies (6% versus 0%; P = .045). A risk analysis in native biopsies only showed that major complications were significantly associated with a low eGFR such that patients with stage 4 or 5 kidney disease had higher odds of complications (odds ratio [95% confidence interval]: stage 4, 9.405 [1.995-44.338]; P = .0393; stage 5, 10.749 [2.218-52.080]; P = .0203) than patients with normal function (eGFR >60 mL/min). The presence of a color flow tract portended a 10.7 times greater risk of having any complication (95% confidence interval, 4.595-24.994; P < .001). Other procedural factors were not significantly associated with complications.

CONCLUSIONS

There is an increased risk of major complications in US-guided random native kidney biopsy in patients with a low eGFR (<30 mL/min) and a patent color flow tract in the immediate postbiopsy setting.

Thromboelastography versus bleeding time for risk of bleeding post native kidney biopsy

Introduction

The risk of bleeding has led to screening of the primary hemostasis before renal biopsy. A bleeding time test (BT) is considered standard practice, but reliance on this test is controversial and its benefits remain questionable. A possible alternative is thromboelastography (TEG). However, data regarding TEG in patients with renal dysfunction is limited.

Objectives

To determine TEG abnormalities and their consequences in patients who underwent a native kidney biopsy.

Methods

A retrospective study of 417 consecutive percutaneous native renal biopsies performed in our Center. If serum creatinine >1.5 mg/dL, the patient underwent either a BT test (period A, January 2015–31 December 2016) or TEG (period B, January 2017–August 2018). In patients with prolonged BT, or an abnormal low maximal amplitude (MA) parameter of TEG, or suspected clinical uremic thrombopathy, the use of desmopressin acetate (DDAVP) was considered.

Results

Most biopsies (90.6%) were done by the same dedicated radiologist. Fifty-one patients had a BT test, which was normal in all tested patients. Seventy-one patients underwent TEG, and it was abnormal in 34 of them, most patients had combined abnormalities. The only parameter related to abnormal TEG was older age (Odds Ratio 1.21 [95% CI 1.09–2.38] p = 0.04 for abnormal Kinetics; OR 1.37 (1.05–1.96) p = 0.037 for abnormal MA). Twenty-six patients (6.23%) had bleeding complications. Risk of bleeding was significantly related to age (1.4 [1.11–7.48] p = 0.04), systolic blood pressure (1.85 [1.258–9.65] p = 0.02), and serum creatinine (1.21 [1.06–3.134] p = 0.048).

Conclusions

TEG abnormalities in patients with renal dysfunction are variable and fail to predict bleeding during kidney biopsy. The decision to administer DDAVP as a preventive measure during these procedures should be based on clinical judgment only.

Post-Renal Biopsy Acute Kidney Injury and Page Kidney from Intra-Renal Hematoma Aggravated by Reversible Contrast-Induced Nephropathy Following Renal Arterial Embolization

Patient: Male, 73-year-old

Final Diagnosis: Page kidney from intra-renal hematoma aggravated by reversible contrast-induced nephropathy following renal arterial embolization

Symptoms: Flank pain • nausea • vomiting

Medication: Apixaban

Clinical Procedure: Kidney biopsy and subsequent renal arterial embolization

Specialty: Nephrology

CKD in diabetes: diabetic kidney disease versus nondiabetic kidney disease

The increasing global prevalence of type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) has prompted research efforts to tackle the growing epidemic of diabetic kidney disease (DKD; also known as diabetic nephropathy). The limited success of much of this research might in part be due to the fact that not all patients diagnosed with DKD have renal dysfunction as a consequence of their diabetes mellitus. Patients who present with CKD and diabetes mellitus (type 1 or type 2) can have true DKD (wherein CKD is a direct consequence of their diabetes status), nondiabetic kidney disease (NDKD) coincident with diabetes mellitus, or a combination of both DKD and NDKD. Preclinical studies using models that more accurately mimic these three entities might improve the ability of animal models to predict clinical trial outcomes. Moreover, improved insights into the pathomechanisms that are shared by these entities - including sodium-glucose cotransporter 2 (SGLT2) and renin-angiotensin system-driven glomerular hyperfiltration and tubular hyper-reabsorption - as well as those that are unique to individual entities might lead to the identification of new treatment targets. Acknowledging that the clinical entity of CKD plus diabetes mellitus encompasses NDKD as well as DKD could help solve some of the urgent unmet medical needs of patients affected by these conditions.

Complications of Percutaneous Renal Biopsy

Percutaneous renal biopsy is widely used for diagnosis, prognosis, and management of nephropathies. Complications may arise after renal biopsy, most commonly in the form of bleeding. Efforts should be taken to optimize modifiable risk factors such as hypertension, thrombocytopenia, and coagulopathy prior to the procedure. Unmodifiable risk factors such as poor renal function, gender, and underlying histologic diagnosis may be used to identify high-risk patients. Delayed presentation of bleeding complications is common, and close clinical follow-up is crucial.

Our experience in emergency treatment of renal haemorrhage

INTRODUCTION

Renal haemorrhage is a potentially life-threatening event requiring emergency surgery. Endovascular therapy is currently the first-line treatment option.

OBJECTIVES

Review patients with renal haemorrhage who required emergency endovascular therapy at our center. Evaluate the causes of the bleeding, the treatment performed and the clinical outcomes.

MATERIAL AND METHODS

We performed a retrospective analysis of consecutive patients with renal bleeding who underwent endovascular therapy from June 2012 to June 2017 at Hospital Universitari Joan XXIII (Tarragona, Spain). Demographic data (age, gender and comorbidity) and other related variables were collected (mechanism of injury, haemodynamic stability and anticoagulant therapy). We also studied the CT angiography findings, time from diagnosis to surgery, endovascular technique and materials used, extent of tissue embolised and outcomes.

RESULTS

Twenty-two (22) patients were included with a mean age of 63 (range 19-85). The aetiology of injuries included: renal biopsy (n=7, 31.8%), bleeding from malignant kidney tumour (n=5, 22.7%), trauma (n=4, 18.2%), angiomyolipoma (n=2, 9.1%), spontaneous bleeding (n=2, 9.1%) and surgical complications (n=2, 9.1%). The endovascular therapy technique was embolisation in all cases. The following materials were used: spheres (9.1%); coils (63.6%); spheres + coils (18.2%); and spheres + plug (9.1%). In 17 cases (77.3%), selective embolisation was performed and in five cases (22.7%), embolisation of the whole kidney. Clinical and technical success rates of 100% were recorded. The 30-day mortality rate was 9.1%.

CONCLUSION

We believe that endovascular therapy is an effective modality for the management of renal bleeding which, in many cases, enables a large part of the renal tissue to be preserved.

A retrospective analysis of complication and adequacy rates of ultrasound-guided native and transplant non-focal renal biopsies

PURPOSE

To assess non-focal ultrasound (US)-guided renal biopsy complication and adequacy rates at our institution.

METHODS

A retrospective analysis of 1067 non-focal renal biopsy cases between 2012 and 2015. Information collected including type of US-guided procedure (US-localized by nephrology vs. real-time US-guided by radiology), sample adequacy, complications, blood work, and histologic data.

RESULTS

602 biopsies were performed by radiology (56.4%) and 465 (43.6%) by nephrology. The overall adequacy rate was 96.1%, with an US-localized rate of 95.7% and real-time US-guided rate of 96.3% (p = 0.58). A lower adequacy rate was noted for 1 biopsy core but there were no differences between 2 and 6 cores (p = 0.001). A lower adequacy rate was found for transplant biopsies vs. native biopsies (p = 0.03). Complication rates were as follows-minor 5.9%, major 4.3%, and life-threatening 0.8%. There were no differences in complication rates between the US-localized and real-time US-guided techniques (p = 0.63). Complications were more likely in patients with a lower hemoglobin, higher serum creatinine, and lower albumin (p < 0.05). No differences were found between the number of cores performed and the complication rates. The complication rate was similar between transplant biopsies vs. native biopsies (p = 0.2). The adequacy rate was lower in trainees (p = 0.01) than experienced radiologists.

CONCLUSIONS

No significant differences were found between US-localized vs. real-time US-guided techniques. A lower adequacy rate was found for trainee radiologists and for transplant biopsies. A lower adequacy rate was also observed when only 1 biopsy pass was performed.

Incidence of major complications after percutaneous native renal biopsies in adults from low-income to middle-income countries: a protocol for systematic review and meta-analysis

INTRODUCTION

Kidney biopsy is an essential tool for guiding clinicians towards diagnoses, treatment and determining prognosis in renal disease. However, the procedure can be marred by various complications. The reported occurrence of complications varies among countries or regions and is also affected by several clinical and technical factors. This systematic review and meta-analysis aims to evaluate the incidence of major complications after percutaneous native renal biopsy in low-income to middle-income countries (LMICs).

METHODS AND ANALYSIS

We will include studies of populations from LMIC as per World Bank 2017 country list. Relevant abstracts published from 1 January 1980 to 30 December 2017 will be searched in PubMed, Cochrane, Excerpta Medica Database (Embase) and African Journals Online, without language restriction. Two reviewers will independently screen, select studies, extract data and assess the risk of bias in each study. A third reviewer will arbitrate in cases of disagreements. The study-specific estimates will be pooled through a random-effects model meta-analysis to obtain an overall summary estimate of the incidence of major complications across studies. Clinical and statistical heterogeneity will be evaluated by Cochrane's Q statistic. Funnel-plot analysis and Egger's test will be used to assess publication bias. Results will be presented by geographical region and income group.

ETHICS AND DISSEMINATION

This study will use published data. Therefore, there is no requirement for ethical approval. This systematic review and meta-analysis is expected to inform healthcare workers and providers about the occurrence of major complications following renal biopsies and highlight possible actions needed to improve the safety of the procedure in LMICs. The final report will be published as an original article in a peer-reviewed journal. Findings will also be presented at a conference and submitted to relevant health authorities.

PROSPERO REGISTRATION NUMBER

CRD42017077656.

Needle guides enhance tissue adequacy and safety of ultrasound-guided renal biopsies

Background

Needle guides have recently come into use for ultrasound-guided percutaneous renal biopsies; however, it is not yet clear if the use of needle guides leads to decreased post-biopsy complication rates and improved tissue yields. Thus, we conducted a retrospective single center study comparing biopsy yield, adequacy, and rates of complications before and after utilization of a needle guide device.

Methods

A retrospective analysis was performed on all native kidney biopsies performed before and after June 2015 corresponding to the start of needle guide use. All biopsies in the latter period of the study were performed by a single operator. We compared clinical characteristics, indications, type of investigation, tissue yield, adequacy of procedure, and rates of major and minor complications.

Results

A total of 343 biopsies were analyzed, 140 in the pre-needle guide use period (Period I) and 203 in the needle guide use period (Period II). Biopsy yields were similar, irrespective of the use of needle guides. Tissue adequacy was better in Period II (93.7% vs. 84%, P < 0.001, with respect to pathologist-reported inconclusive biopsies. There were no differences in terms of major complications (1.7%) for the two periods; however, the rate of minor complications (8.4%) was significantly reduced in Period II (P = 0.006). According to multiple logistic regression analysis, not using a needle guide (odds ratio, 3.70; P < 0.001) along with low hemoglobin level, higher pre-dialysis serum creatinine level, and high urinary red blood cell count were significant predictors of biopsy complications.

Conclusion

Use of a needle guide improves biopsy adequacy and is associated with reduced rates of minor complications in native renal biopsies. Therefore, needle guides may be recommended in percutaneous renal biopsies, especially when transitioning to single-operator performed procedures.

Chronic kidney disease

Chronic kidney disease (CKD) is defined by persistent urine abnormalities, structural abnormalities or impaired excretory renal function suggestive of a loss of functional nephrons. The majority of patients with CKD are at risk of accelerated cardiovascular disease and death. For those who progress to end-stage renal disease, the limited accessibility to renal replacement therapy is a problem in many parts of the world. Risk factors for the development and progression of CKD include low nephron number at birth, nephron loss due to increasing age and acute or chronic kidney injuries caused by toxic exposures or diseases (for example, obesity and type 2 diabetes mellitus). The management of patients with CKD is focused on early detection or prevention, treatment of the underlying cause (if possible) to curb progression and attention to secondary processes that contribute to ongoing nephron loss. Blood pressure control, inhibition of the renin-angiotensin system and disease-specific interventions are the cornerstones of therapy. CKD complications such as anaemia, metabolic acidosis and secondary hyperparathyroidism affect cardiovascular health and quality of life, and require diagnosis and treatment.

Diffuse Renal Cortical Hemorrhage in the Setting of Subcapsular Hematoma: Diagnosis and Treatment with Embolization

PURPOSE

To describe radiologic findings, embolization technique, and clinical outcomes in patients with renal subcapsular hematoma and diffuse cortical hemorrhage.

MATERIALS AND METHODS

Ten patients with renal subcapsular hematoma and diffuse cortical hemorrhage were reviewed. Nine of the 10 had undergone procedures (nephrostomy, n = 4; biopsy, n = 4; embolization of a cerebral aneurysm, n = 1) and 1 patient was receiving oral anticoagulation. Computed tomography (CT), angiography, and embolization of bleeding sites were performed in all patients.

RESULTS

CT and angiography revealed subcapsular hematoma with diffuse cortical hemorrhage at the level of the interlobar and/or arcuate branches. Total embolization of intrarenal arterial branches was required in 3 patients. Partial embolization, which also resulted in permanent functional loss, was required in 4. The functional loss was likely caused by the embolization procedure and the underlying renal disease. In these 4 patients, renal failure was demonstrated by scintigraphy in 3 cases and based on the need to start chronic hemodialysis in 1 case. In the remaining three patients, embolization did not compromise renal function.

CONCLUSIONS

Diffuse cortical hemorrhage unrelated to the site of puncture may be seen in some cases of subcapsular hematoma. The cause is likely the laceration of transcortical capsular arteries secondary to enlargement of the subcapsular hematoma. In the present case series, embolization achieved hemorrhage control, but loss of renal function was observed in patients with underlying renal disease.