Renal biopsy practice in France: results of a nationwide study

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.

Glomeruli Count and Arterial Injury in Real-Time Ultrasound-Guided Needle Kidney Biopsy Specimens: Adequacy of Three Approaches for Pig Kidneys

INTRODUCTION

Real-time ultrasound-guided percutaneous kidney biopsy is essential for diagnosis and treatment planning; nonetheless, the optimal puncture approach has yet to be established. In vivo, performing different approaches on the same patient at once is not possible. This study aimed to determine the impact of different approaches on the number of obtained glomeruli and their potential to cause arterial injury using pig kidneys, which are similar to humans.

METHODS

A total of 120 pig kidneys (60 right-sided kidneys and 60 left-sided kidneys) for research were obtained from a slaughterhouse. The specimens were collected from the lower pole on the sagittal plane of the kidney using three different approaches on the same kidney: caudocranial approach, caudal to cranial; craniocaudal approach, cranial to caudal; and vertical approach, through the surface cortex. Five blinded pediatric nephrologists assessed the number of glomeruli and arterial injuries.

RESULTS

Overall, 360 specimens were collected from the kidneys through biopsy using a 16-gauge needle (mean vertical kidney length, 11.2 ± 0.7 cm; mean depth, 3.47 ± 0.23 cm). No significant difference in the incidence of arterial injury was observed between the three approaches (caudocranial vs. craniocaudal vs. vertical approaches: 78% vs. 87% vs. 87%, p = 0.14). In contrast, the vertical approach retrieved significantly more glomeruli than the caudocranial and craniocaudal approaches (caudocranial approach: 7.5 ± 2.8, craniocaudal approach: 7.8 ± 2.7, and vertical approach: 8.9 ± 3.3, p < 0.001).

CONCLUSIONS

Considering its efficacy and safety profile, the vertical approach may be preferred, as more glomeruli can be obtained without increasing the incidence of arterial injury. Although the results cannot be directly extrapolated to humans due to the differences between species, they still offer important insights into the characteristics of each approach.

Risk of bleeding after percutaneous native kidney biopsy in patients receiving low-dose aspirin: a single-center retrospective study

BACKGROUND

Although discontinuation of antiplatelet agents at least 5 days before kidney biopsy is commonly recommended, the evidence behind this practice is of low level. Indeed, few non-randomized studies previously showed an equivalent risk of bleeding in patients receiving aspirin therapy.

METHODS

We conducted a single center retrospective study comparing the risk of complications after percutaneous native kidney biopsy in patients who received low-dose aspirin (ASA) within 5 days from biopsy and those who did not. The main outcome was the difference in the incidence of major complications (red blood cell transfusion, need for selective arterial embolization, surgery, nephrectomy). Secondary outcomes included difference in minor complications, comparison between patients who received ASA within 48 h or within 3-5 days, identification of independent factors predictive of major complications.

RESULTS

We analyzed data on 750 patients, of whom 94 received ASA within 5 days from biopsy. There were no significant differences in the proportion of major complications in patients receiving or not receiving ASA (2.59% and 3.19%, respectively, percentage point difference 1%, 95% CI - 3 to 4%, p = 0.74). Groups were also comparable for minor complications; among patients receiving ASA, there were no differences in major bleeding between those who received ASA within 48 h or 3-5 days from biopsy. Significant baseline predictors of major bleeding in our cohort were platelet count lower than 120*10³/microliter, higher diastolic blood pressure and higher blood urea.

CONCLUSIONS

Treatment with low-dose ASA within 5 days from kidney biopsy did not increase the risk of complications after the procedure.

Major Bleeding of Transjugular Native Kidney Biopsies. A French Nationwide Cohort Study

Introduction

The risk of bleeding associated with transjugular kidney biopsies is unclear, and which patients are the best candidates for this route is unknown.

Methods

This was a retrospective cohort study comparing proportion of bleeding associated with transjugular versus percutaneous native kidney biopsies in all patients in France in the 2010–2019 period. Major bleeding at day 8 (i.e., blood transfusions, hemorrhage/hematoma, angiographic intervention, nephrectomy) and risk of death at day 30 were assessed, and we used a bleeding risk score initially developed for the percutaneous route.

Results

Our analysis included 60,331 patients (transjugular route: 5305; percutaneous route: 55,026 patients). The observed proportion of major bleeding varied widely (transjugular vs. percutaneous): 0.4% versus 0.5% for the lowest risk scores (0–4) to 19.1% versus 30.8% for the highest risk scores (≥35). Transjugular was more frequently used than percutaneous route (39% vs. 24%) when the risk score was ≥20 (15,133/60,331; 25% of all patients). Transjugular was associated with a lower risk of major bleeding than percutaneous route in multivariate analyses (odds ratio [OR]: 0.88 [0.78–0.99]), especially for scores ≥20 (OR: 0.83 [0.72–0.96], (i.e., 25% of patients). Major bleeding was associated with an increased risk of death both for transjugular (OR: 1.77 [1.00–3.14]) and percutaneous (OR: 1.80 [1.43–2.28]) routes.

Conclusions

The transjugular route is independently associated with a lower risk of bleeding than the percutaneous route, especially in high-risk patients identified by a preprocedure risk score ≥20 (i.e., 25% of patients). Major bleeding is associated with an increased risk of death for both routes.

Kidney biopsy practice amongst Australasian nephrologists

BACKGROUND

Percutaneous kidney biopsy is the gold standard investigation for the diagnosis of kidney diseases. The associated risks of the procedure depend on the skill and experience of the proceduralist as well as the characteristics of the patient. The Kidney Health Australia - Caring for Australasians with Renal Impairment (KHA-CARI) guidelines on kidney biopsies, published in 2019, are the only published national kidney biopsy guidelines. As such, this study surveys current kidney biopsy practices in Australasia and examines how they align with the Australian guidelines, as well as international biopsy practice.

METHODS

A cross-sectional, multiple-choice questionnaire was developed examining precautions prior to kidney biopsy; rationalisation of medications prior to kidney biopsy; technical aspects of kidney biopsy; complications of kidney biopsy; and indications for kidney biopsy. This was distributed to all members of the Australian and New Zealand Society of Nephrology (ANZSN).

RESULTS

The response rate for this survey is approximately 21.4 % (182/850). Respondents found agreement (> 75.0 %) in only six out of the twelve questions (50.0 %) which assessed their practice against the KHA-CARI guidelines.

CONCLUSIONS

This is the first study of its kind where kidney biopsy practices are examined against a clinical guideline. Furthermore, responses showed that practices were incongruent with guidelines and that there was a lack of consensus on many issues.

Desmopressin acetate to prevent bleeding in percutaneous kidney biopsy: a systematic review

BACKGROUND

Kidney biopsy is the gold standard for diagnosing kidney disease but may result in bleeding, especially in uraemia. DDAVP (1-deamino-8-d-arginine vasopressin) may reduce uraemic bleeding but guidelines on its use are lacking.

AIM

To evaluate whether DDAVP reduced bleeding complications after percutaneous kidney biopsies.

METHODS

We searched CENTRAL, PubMed, Embase, LILACS, WHO Trials Registry and ClinicalTrials.gov until May 2019 for randomised controlled trials (RCT), quasi-RCT and prospective cohort studies that compared DDAVP with placebo or no intervention, prior to native or allograft kidney biopsy. The primary outcome was post-biopsy bleeding. Secondary outcome was adverse events related to DDAVP.

RESULTS

Abstracts of 270 identified papers were examined and 24 selected for evaluation. Two studies, one RCT and one prospective cohort that collectively evaluated 738 native kidney biopsies, met the inclusion criteria. One enrolled individuals with serum creatinine ≤1.5 mg/dL (132 μmol/L) and/or estimated glomerular filtration rate ≥60 mL/min/1.73 m² while the other evaluated biopsies with serum creatinine >150 μmol/L. DDAVP was administered as a single subcutaneous dose of 0.3 μg/kg in both studies. Data were not pooled for meta-analysis due to clinical heterogeneity. GRADE quality of evidence from these two studies was low for DDAVP preventing any bleeding complication after native kidney biopsy. Low quality evidence suggested that adverse effects were not increased in DDAVP therapy. No prospective studies evaluated DDAVP in transplant kidney biopsies.

CONCLUSION

Currently available prospective data are insufficient to support the routine use of DDAVP prior to percutaneous kidney biopsies hence high quality trials are required.

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.

Major Bleeding and Risk of Death after Percutaneous Native Kidney Biopsies: A French Nationwide Cohort Study

BACKGROUND AND OBJECTIVES

The risk of major bleeding after percutaneous native kidney biopsy is usually considered low but remains poorly predictable. The aim of the study was to assess the risk of major bleeding and to build a preprocedure bleeding risk score.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our study was a retrospective cohort study in all 52,138 patients who had a percutaneous native kidney biopsy in France in the 2010-2018 period. Measurements included major bleeding (i.e., blood transfusions, hemorrhage/hematoma, angiographic intervention, or nephrectomy) at day 8 after biopsy and risk of death at day 30. Exposures and outcomes were defined by diagnosis codes.

RESULTS

Major bleeding occurred in 2765 of 52,138 (5%) patients (blood transfusions: 5%; angiographic intervention: 0.4%; and nephrectomy: 0.1%). Nineteen diagnoses were associated with major bleeding. A bleeding risk score was calculated (Charlson index [2-4: +1; 5 and 6: +2; >6: +3]; frailty index [1.5-4.4: +1; 4.5-9.5: +2; >9.5: +3]; women: +1; dyslipidemia: -1; obesity: -1; anemia: +8; thrombocytopenia: +2; cancer: +2; abnormal kidney function: +4; glomerular disease: -1; vascular kidney disease: -1; diabetic kidney disease: -1; autoimmune disease: +2; vasculitis: +5; hematologic disease: +2; thrombotic microangiopathy: +4; amyloidosis: -2; other kidney diagnosis: -1) + a constant of 5. The risk of bleeding went from 0.4% (lowest score group =0-4 points) to 33% (highest score group ≥35 points). Major bleeding was an independent risk of death (500 of 52,138 deaths: bleeding: 81 of 2765 [3%]; no bleeding: 419 of 49,373 [0.9%]; odds ratio, 1.95; 95% confidence interval, 1.50 to 2.54; P<0.001).

CONCLUSIONS

The risk of major bleeding after percutaneous native kidney biopsy may be higher than generally thought and is associated with a twofold higher risk of death. It varies widely but can be estimated with a score useful for shared decision making and procedure choice.

Desmopressin for the prevention of bleeding in percutaneous kidney biopsy: efficacy and hyponatremia

BACKGROUND

Desmopressin is used to reduce bleeding complications for kidney biopsies with azotemia but little is known about desmopressin-induced hyponatremia in these individuals. We aimed to evaluate the impact of desmopressin prophylaxis on severe hyponatremia and bleeding after kidney biopsies in individuals with renal impairment.

METHOD

This is a single-center retrospective cohort study of consecutive adults with serum creatinine ≥ 150 µmol/L and had ultrasound-guided percutaneous native or transplant kidney biopsies between June 2011 and July 2015. Data were retrieved from electronic medical records. Primary outcomes were the use of desmopressin prophylaxis and severe hyponatremia (serum sodium ≤ 125 mmol/L) within 7 days post-biopsy. Secondary outcome was post-biopsy bleeding.

RESULTS

240 native kidney and 196 allograft biopsies were performed. Median age was 51 (IQR 42.3, 60) years and eGFR was 21.9 (12.9, 30.1) ml/min/1.73 m². Although patients prescribed desmopressin prophylaxis (n = 226) had higher serum creatinine [279 (201, 392) vs. 187 (160, 241), p < 0.001], bleeding (15.0% vs. 13.3%, p = 0.60) was not significantly different with and without desmopressin. Severe hyponatremia occurred in 30 biopsies (6.9%) with nadir serum sodium level of 122 (119, 124) mmol/L at 3 (2, 5) days after biopsy, more frequently among those with desmopressin prophylaxis (10.7% vs. 3.0%, p = 0.002). Multi-variate analysis found that pre-biopsy serum sodium level [adjusted OR 0.80 (95% CI 0.72, 0.90), p < 0.001] and desmopressin prophylaxis [adjusted OR 4.02 (95% CI 1.58, 10.21), p = 0.003] were independently associated with severe hyponatremia after kidney biopsy.

CONCLUSION

Pre-biopsy desmopressin was associated with severe hyponatremia in individuals with renal impairment; hence, susceptible patients given desmopressin should be closely monitored.

Role of color Doppler ultrasound in the early diagnosis of a major complication after percutaneous renal biopsy: two case reports

Percutaneous renal biopsy (PRB) is an important procedure in the diagnostic and prognostic evaluation of renal disorders. Despite the relative simplicity, it can be a possible cause of iatrogenic renovascular injury. We describe two cases of iatrogenic pseudoaneurysm, a major post-biopsy complication, in two pediatric patients with persistent micro- and macro-hematuria, promptly diagnosed using color Doppler ultrasound, confirmed with renal arteriography and treated with embolization.

Manual compression and reflex syncope in native renal biopsy

Background

Complications associated with diagnostic native percutaneous renal biopsy (PRB) must be minimized. While life threatening major complications has been extensively investigated, there is little discussion regarding minor bleeding complications, such as a transient hypotension, which directly affect patients’ quality of life. There is also little evidence supporting the need for conventional manual compression following PRB. Therefore, this study evaluated the relationship between minor and major complications incidence in patients following PRB with or without compression.

Methods

This single-center, retrospective study included 456 patients (compression group: n = 71; observation group: n = 385). The compression group completed 15 min of manual compression and 4 h of subsequent strict bed rest with abdominal bandage. The observation group completed 2 h of strict bed rest only. The primary outcome of interest was transient symptomatic hypotension (minor event).

Results

Of the 456 patients, 26 patients encountered intraoperative and postoperative transient hypotension, which were considered reflex syncope without tachycardia. Univariate analysis showed that symptomatic transient hypotension was significantly associated with compression. This association remained significant, even after adjustment of covariates using multivariate logistic regression analysis (adjusted odds ratio 3.27; 95% confidential interval 1.36–7.82; P = 0.0078).

Conclusion

Manual compression and abdominal bandage significantly increased the frequency of reflex syncope during native PRB. It is necessary to consider the potential benefit and risk of compression maneuvers for each patient undergoing this procedure.

Electronic supplementary material

The online version of this article (10.1007/s10157-018-1560-8) contains supplementary material, which is available to authorized users.

Measuring hemoglobin prior to early discharge without routine surveillance ultrasound after percutaneous native renal biopsy in children

BACKGROUND

We aimed to evaluate the role of post-procedural hemoglobin (hb), without pre-discharge ultrasound (US), after US-guided renal biopsy in children.

METHODS

A retrospective review was conducted of consecutive outpatient native kidney biopsies over an 8-year period. Procedures were performed under real-time US guidance. Data collected included number of passes, presence and size of perinephric hematoma, age, body mass index (BMI), blood pressure (BP), fasting status, hb and platelets. Continuous variables were expressed as mean ± standard deviation, group differences were tested with Student's unpaired t test and analysis of variance and correlations were assessed using Pearson's r. Significance was defined as p < 0.05. Hb changes (g/L), percentage hb (%hb) change, hematoma size and positive and negative predictive values (PPV, NPV, respectively) were analyzed.

RESULTS

A total of 330 procedures in 300 children (141 females, mean age 11.2 ± 4.30 years) were analyzed. Post-procedural hematoma occurred in 63%. There was a significant (p = 0.0001) post-procedural hb decrease of 6.3 ± 5.5 g/L and %hb decrease of 4.56 ± 4.01%. Fasting during pre-procedural hb estimation and procedural hematoma was associated with a greater hb drop. A ≥10% hb drop had 73% PPV for repeat blood work and US and a 17% PPV for admission, whereas a <10% hb drop had a NPV of 84% and 98%, respectively. Hb change showed a weak correlation with age, and hematoma size showed a weak inverse correlation with platelet count, but no correlation with BMI, number of passes or BP.

CONCLUSIONS

Bleeding complications from US-guided native kidney biopsies in pediatric outpatients can be safely followed by a complete blood count at 6 h post procedure. A 10% hb decrease is strongly associated with requirement for further testing and/or admission.

A prospective audit of complications in 100 consecutive pediatric percutaneous renal biopsies done under real-time ultrasound guidance

Despite being a common procedure, percutaneous renal biopsy (PRB) carries the potential for complications. The British Association of Paediatric Nephrologist (BAPN) has published standards for pediatric PRB. As Indian data are scarce, we conducted a prospective audit of 100 consecutive pediatric renal biopsies (60% males) under real-time ultrasound guidance. Nephrotic syndrome was the most common indication for PRB (68%) with minimal change disease (30%) and focal segmental glomerulosclerosis (25%) being the most common histopathological lesions. Gross hematuria was observed in six cases. Major complications was noted in one case, who needed longer hospital stay. The result of the audit demonstrated achievability of BAPN standards. In addition, we also show the usefulness of 16 gauge biopsy needle over 18 gauge biopsy needles (median number of glomeruli 25, range 3–90 vs 13, range 6–46, P = 0.001) without any increase in complications. Being a single center study, we do hope that our results will encourage a wider survey on the current state of pediatric PRB.

Positive trends in paediatric renal biopsy service provision in the UK: a national survey and re-audit of paediatric renal biopsy practice

BACKGROUND

Paediatric renal biopsy standards introduced in the UK in 2010 were intended to reduce variation and improve practice. A concurrent national drive was aimed at building robust paediatric nephrology networks to ensure services cater for the needs of the family and minimise time away from home. We aimed to identify current national practice since these changes on behalf of the British Association for Paediatric Nephrology.

METHODS

All UK paediatric nephrology centres were invited to complete a survey of their biopsy practice, including advance preparation. From 1 January to 30 June 2012, a national prospective audit of renal biopsies was undertaken at participating centres comparing practice with the British Association for Paediatric Nephrology (BAPN) standards and audit results from 2005.

RESULTS

Survey results from 11 centres demonstrated increased use of pre-procedure information leaflets (63.6 % vs 45.5 %, P = 0.39) and play preparation (90.9 % vs 9.1 %, P = 0.0001). Audit of 331 biopsies showed a move towards day-case procedures (49.5 % vs 32.9 %, P = 0.17) and reduced major complications (4.5 % vs 10.4 %, P = 0.002). Biopsies with 18-gauge needles had significantly higher mean pass rates (3.2 vs 2.3, P = 0.0008) and major complications (15.3 % vs 3.3 %, P = 0.0015) compared with 16-gauge needles.

CONCLUSIONS

Percutaneous renal biopsy remains a safe procedure in children, thus improving family-centered service provision in the UK.

Renal biopsy practice: What is the gold standard?

Renal biopsy (RB) is useful for diagnosis and therapy guidance of renal diseases but incurs a risk of bleeding complications of variable severity, from transitory haematuria or asymptomatic hematoma to life-threatening hemorrhage. Several risk factors for complications after RB have been identified, including high blood pressure, age, decreased renal function, obesity, anemia, low platelet count and hemostasis disorders. These should be carefully assessed and, whenever possible, corrected before the procedure. The incidence of serious complications has become low with the use of automated biopsy devices and ultrasound guidance, which is currently the “gold standard” procedure for percutaneous RB. An outpatient biopsy may be considered in a carefully selected population with no risk factor for bleeding. However, controversies persist on the duration of observation after biopsy, especially for native kidney biopsy. Transjugular RB and laparoscopic RB represent reliable alternatives to conventional percutaneous biopsy in patients at high risk of bleeding, although some factors limit their use. This aim of this review is to summarize the issues of complications after RB, assessment of hemorrhagic risk factors, optimal biopsy procedure and strategies aimed to minimize the risk of bleeding.

Factors that can minimize bleeding complications after renal biopsy

Renal biopsy is a very important diagnostic tool in the evaluation of renal diseases. However, bleeding remains to be one of the most serious complications in this procedure. Many new techniques have been improved to make it safer. The risk factors and predictors of bleeding after percutaneous renal biopsy have been extensively reported in many literatures, and generally speaking, the common risk factors for renal biopsy complications focus on hypertension, high serum creatinine, bleeding diatheses, amyloidosis, advanced age, gender and so on. Our primary purpose of this review is to summarize current measures in recent years literature aiming at minimizing the bleeding complication after the renal biopsy, including the drug application before and after renal biopsy, operation details in percutaneous renal biopsies, nursing and close monitoring after the biopsy and other kinds of biopsy methods.

Transjugular renal biopsy in a case of nephrotic syndrome with extrahepatic portal venous obstruction

Renal biopsy in patients with nephrotic syndrome helps to establish the pathological diagnosis and subsequent treatment. In certain circumstances, biopsies are difficult to obtain because of the risk of bleeding. We report a case where renal biopsy was obtained through the transjugular route in a patient who had nephrotic syndrome with extrahepatic portal venous obstruction.

Safety and complications of percutaneous kidney biopsies in 715 children and 8573 adults in Norway 1988-2010

BACKGROUND AND OBJECTIVES

Skepticism about performing renal biopsies is often because of uncertainty regarding risk of complications. The aim of this study was to evaluate safety and relevant complications of renal biopsies in pediatric and adult patients in a large national registry study.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Kidney biopsies reported in the Norwegian Kidney Biopsy Registry from 1988 to 2010 were included. Risk factors for major complications (blood transfusion and/or surgical or catheter intervention) were analyzed using logistic regression statistics.

RESULTS

Of the 9288 biopsies included, 715 were from children, and 8573 were from adults (≥18 years). Median age was 49 years (range=2 weeks to 94 years). Gross hematuria appeared after biopsy in 1.9% of the patients; 0.9% of patients needed blood transfusion, and 0.2% of patients needed surgical intervention/catheterization. The frequencies were 1.9%, 0.9%, and 0.2% in adults and 1.7%, 0.1% and 0.1% in children, respectively; 97.9% of the biopsies were without complications. In unadjusted analyses, risk factors for major complications were age>60 years, estimated GFR<60 ml/min per 1.73 m(2), systolic hypertension, acute renal failure, and smaller clinical center size (<30 biopsies/yr). Adjusted analyses (adjusted for age and/or estimated GFR) showed higher odds ratios (OR) only for smaller clinical center (OR=1.60 [1.02-2.50]) and low estimated GFR (estimated GFR=30-59 ml/min per 1.73 m(2) [OR=4.90 (1.60-14.00)] and estimated GFR<30 ml/min per 1.73 m(2) [OR 15.50 (5.60-43.00)]).

CONCLUSIONS

Percutaneous renal biopsy is a low-risk procedure in all ages. Reduced estimated GFR and smaller center size are associated with an increased risk of major complications.

Safety and diagnostic yield of renal biopsy in the intensive care unit

PURPOSE

Renal biopsy (RB) is occasionally performed in critically ill patients. The safety and impact of RB in this setting have not been reported.

METHODS

A 10-year (2000-2009) retrospective multicentre study was conducted in ten French intensive care units (ICU) on patients who underwent RB during their management. Medical files were retrieved for data analysis.

RESULTS

Seventy-seven patients underwent an RB of which 68 (88 %) were on a native kidney and 9 (12 %) on a transplanted kidney. Percutaneous ultrasound-guided RB was used in most cases (87 %). Fifty-seven per cent of the patients were on mechanical ventilation at the time of RB. RB-related complications occurred in 17 (22 %) patients, two were graded as severe (requirement for kidney embolization, eventually successful). In 35 (51 %) non-transplanted patients, RB established a specific diagnosis other than acute tubular necrosis (ATN), which was diagnosed in only 18 % of patients. In the remaining patients, only non-specific lesions were observed. Therapeutic modifications followed RB in 14 (21 %) non-transplanted patients. Presence of signs of systemic disease involving the renal tract, occurrence of renal failure before hospital admission, and absence of any factor usually associated with ATN significantly predicted the presence of a specific diagnosis at RB other than ATN.

CONCLUSIONS

In this cohort, the contribution of RB to diagnosis and treatment was undeniable, but at the expense of frequent adverse events although most of them were not considered severe.

Comparative safety and efficiency of five percutaneous kidney biopsy approaches of native kidneys: a multicenter study

BACKGROUND

Renal biopsy (RB) is necessary for the diagnosis, prognosis, and therapy guidance of native kidney diseases. Few studies have compared outcomes of RB procedures. We retrospectively compared the safety and efficiency of five biopsy procedures.

METHODS

The number of glomeruli on light microscopy (LM) and on immunofluorescence (IF) and serious adverse events following RB performed in five nephrology units (C1-C5) were collected. C1 performed ultrasound (US) assessment before RB and used a 14-gauge core-cutting needle biopsy gun, C2 US guidance and a 14-gauge needle, C3 tomodensitometry guidance and a 14-gauge needle, C4 US guidance and a 16-gauge needle, and C5 tomodensitometry guidance and a 16-gauge needle.

RESULTS

RB was performed in 943 adults between January 2006 and July 2010. Serious adverse events occurred in 1.5% of biopsies. The complication rate was not different between nephrology units. The mean number of glomeruli on biopsy was 14.2 ± 8.6 with LM and 4.4 ± 3.3 on IF. It was different according to the nephrology unit for LM (p = 0.01) and for IF (p < 0.001). The number of failed biopsies was influenced by the nephrology unit and radiological guidance technique, favoring real-time US guidance. Failed biopsies using US or tomodensitometry assessment before RB was certainly due to kidney imprecise localization since it was often non-renal tissue sampling. At least 10 glomeruli were found in 69% of biopsies on LM. This rate varied according to the nephrology unit (p = 0.004) and was higher when 14-gauge needles were used in comparison with 16-gauge needles.

CONCLUSION

RB is safe regardless of the technical procedure, but radiological guidance and needle size influence the efficiency of biopsies.

[Renal biopsy practice: results of a French study and recommendations]

BACKGROUND

Although several risk factors associated with complications after renal biopsy (RB) have been identified, recommendations for RB procedures are still lacking. Our working group, appointed by the scientific commission of the Société de néphrologie in France, aimed to depict the main aspects of the practice of RB in adults in France, before establishing some guidelines.

METHODS

Members of the Société de néphrologie in France were asked to participate to a questionnaire survey on RB procedures.

RESULTS

Eighty-eight nephrologists from 74 units (27 in teaching hospitals, 35 in public general hospitals, and 12 in private centers) participated in our study. Native kidney and graft biopsies were performed in 73 and 35 units, respectively. RB activity was highly variable among units, ranging from several hundred to less than ten per year. Transjugular RB was judged to be smoothly accessible in 28 out of 73 units (38.4%). Significant variations in practices were observed regarding patient information before RB, assessment of hemorrhagic risk factors, care of patients with antiplatelet agents and hemorrhagic risk factors, and radiological guidance. Early discharge (<12 hours) was the rule in three (4.1%) units for native kidney biopsies and in ten (28.6%) units for graft biopsies.

CONCLUSIONS

Our study is the first to provide a representative picture of "everyday" RB practices in a country. Consensual recommendations on all points mentioned are provided here.

Histological diagnosis determines complications of percutaneous renal biopsy: a single-center experience in 353 patients

BACKGROUND

We studied the connection between complication occurrence related to renal biopsies and histological diagnoses of the biopsy specimen. We also analyzed the distribution of diagnoses in our population.

METHODS

We retrospectively studied 353 patients undergoing renal biopsy at the same center. Biopsies were performed after marking the site of puncture by ultrasound imaging. Connection of complications with diagnoses and clinical parameters was evaluated.

RESULTS

Complication rate was 44.5% in our study. There was a significantly lower rate of complications in patients with diabetic nephropathy (likelihood ratio, LR = 0.44) or acute tubular necrosis (LR = 0.38), while patients with thin basement membrane syndrome had a more than 6-fold higher risk for development of intrarenal hemorrhage than others. Patients with vasculitis (LR = 2.88) and acute interstitial nephritis (LR = 3.18) have a more than doubled risk for arteriovenous shunts, while in patients with severe arteriosclerosis the prevalence of this complication was lower (LR = 0.46). Arteriovenous shunts developed also at a significantly higher rate in patients with rapidly progressive glomerulonephritis.

CONCLUSION

Patients with thin basement membrane syndrome, vasculitis, rapidly progressive glomerulonephritis or acute interstitial nephritis should be observed more carefully after renal biopsy due to the significantly higher risk for certain complications.