Outpatient versus inpatient renal biopsy: a retrospective 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.

Quality Improvement Initiatives in Renal Biopsy for Patient-Centered Communication by Shared Decision Making

Background: Renal biopsy is the gold standard for diagnosing renal disease. The major concern is bleeding. Shared decision making (SDM) has been reported to improve communication but has never been used regarding renal biopsy. Methods: We launched a 5-year project on SDM for renal biopsy. We collected cases of renal biopsy and bleeding, and cases of SDM. The process of quality improvement (QI) for SDM is also shared. Results: Taichung Veterans General Hospital has the largest number of renal biopsy cases, and the lowest bleeding rate in Taiwan. We enlisted a core team for this QI project and conducted stakeholder mapping. In 2017, we conducted a small pilot study for SDM based on printed material as a decision aid. The satisfaction rate was 95.5%. From 2018 to 2019, we improved SDM patients’ decision aid from printed material to four videos, designing questions to consolidate their understanding, and a unique information platform. The above improvements facilitated the utilization of SDM for renal biopsy (81.27% in 2020 and 100% in 2021). Even with higher bleeding complications in 2019 and 2020, patients remained satisfied when we launched SDM prior to renal biopsy. Conclusion: This is the first study regarding SDM on renal biopsy. Through SDM, patients had time to understand renal biopsy, including risk and benefit. We recommend SDM to elaborate renal biopsy in clinical practice.

Indications and considerations for kidney biopsy: an overview of clinical considerations for the non-specialist

Around 3 million people in the UK have chronic kidney disease and 20% of hospital admissions are complicated by acute kidney injury. Decline in kidney function is not a diagnosis; it is essential to identify and treat underlying causes of acute and chronic kidney disease to either achieve recovery or slow the decline of kidney function. Thorough clinical assessment and simple investigations help determine the category of kidney injury (pre-renal, intrinsic or post-renal) and inform the need for kidney biopsy, which can provide significant information in the evaluation of suspected intrinsic kidney disease, supporting diagnosis, guiding prognosis and management, and identifying disease relapse. The procedure is invasive and not without risk, which although small has the potential to be both organ- and life-threatening. This review outlines roles of kidney biopsy for the non-specialist, with focus of its role in patients with diabetes, lupus, myeloma and in the older patient.

Safety of Kidney Biopsy when Performed as an Outpatient Procedure

INTRODUCTION

Kidney biopsy remains the gold standard for the diagnosis of most renal diseases. A major obstacle to performing a biopsy is safety concerns. However, many safety measures are not evidence based and therefore vary widely between centers. We sought to determine the rate and timing of kidney biopsy complications in our center, to compare the complication rate between native and transplant kidney biopsies, to evaluate the feasibility of performing kidney biopsies as an outpatient procedure and the value of a postbiopsy ultrasound before discharge, and to identify risk factors for complications.

METHODS

We performed a single-center, retrospective, observational study at the Division of Nephrology of the University Hospital Zurich including all patients who underwent renal biopsy between January 2005 and December 2017. Major bleeding (primary outcome) and any other bleeding or nonbleeding complications (secondary outcomes) were compared between native and transplant kidney biopsies and between inpatient and outpatient procedures and correlated with clinical factors possibly affecting bleeding risk.

RESULTS

Overall, 2,239 biopsies were performed in 1,468 patients, 732 as inpatient and 1,507 as outpatient procedures. Major bleeding was observed in 28 (3.8%) inpatient and in 15 (1.0%) outpatient procedures, totaling to 43 (1.9%) of all biopsies. Major bleeding requiring intervention amounted to 1.0% (0.5% of outpatient procedures). Rate of major bleeding was similar between native and transplant kidneys. 13/15 (87%) bleeding episodes in planned outpatient procedures were detected during the 4-h surveillance period. Risk factors for bleeding were aspirin use, low eGFR, anemia, cirrhosis, and amyloidosis. Routine postbiopsy ultrasound did not change management.

CONCLUSIONS

Kidney biopsy is an overall safe procedure and can be performed as an outpatient procedure in most patients with an observation period as short as 4 h. The value of routine postbiopsy ultrasound is questionable.

Safety of Renal Biopsy by Physicians with Short Nephrology Experience

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

Complications of Outpatient and Inpatient Renal Biopsy: A Systematic Review and Meta-Analysis

Background: The evidence indicates that the optimal observation period following renal biopsy ranges between 6 and 8 h. This systematic review and meta-analysis explored whether differences exist in the complication rates of renal biopsies performed in outpatient and inpatient settings. Methods: We searched the MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews from 1985 to February 2020. Two reviewers independently selected studies evaluating the bleeding risk from renal biopsies performed in outpatient and inpatient settings and reviewed their full texts. The primary and secondary outcomes were risks of bleeding and major events (including mortality) following the procedure, respectively. Subgroup analysis was conducted according to the original study design (i.e., prospective or retrospective). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random effect meta-analysis. Heterogeneity was assessed using the I² test. Results: Data from all 10 eligible studies, which included a total of 1801 patients and 203 bleeding events, were included for analysis. Renal biopsies in outpatient settings were not associated with a higher bleeding risk than those in inpatient settings (OR = 0.81; 95% CI, 0.59–1.11; I² = 0%). The risk of major events was also comparable across both groups (OR = 0.45; 95% CI, 0.16–1.29; I² = 4%). Conclusions: Similar rates of bleeding and major events following renal biopsy in outpatient and inpatient settings were observed.

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.

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.

Outpatient percutaneous native renal biopsy: safety profile in a large monocentric cohort

OBJECTIVES

We aim to evaluate the safety of performing percutaneous native kidney biopsy (PKB) as an outpatient procedure (implying an observation period of 6 hours) compared with the traditional inpatient policy.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

Group I, in whom PKB was performed in the outpatient department (2012-2016) and followed by 6 hours' observation period and then by regular outpatient visits and group II, in whom PKB was performed and followed by at least 1 day hospital admission. Group II included retrospectively retrieved patients who underwent PKB in our Institution between January 2000 and November 2012 as an inpatient procedure. All biopsies were performed by a single nephrologist following a structured protocol.

RESULTS

462 biopsies were reviewed, 210 (45.5%) of patients were women and the mean age was 54.7±17.9 years. One hundred and twenty-nine (27.9%) of these biopsies were performed in outpatients. A total of 36 (7.8%) of patients developed a complication, and of those, 9 (1.9%) suffered for a major complication (arteriovenous fistula (six cases, 1.2%), ischaemic stroke (2; 0.4%), thromboembolic pulmonary embolism (1; 0.2%)) and 27 (5.8%) for minor(macroscopic haematuria (12 cases, 2.6%), haematomas on sonography not requiring intervention (15 cases, 3.2%)). When comparing the complication rate between groups I and II, no statical difference was observed. When analysing together both groups, after multivariate analysis, serum creatinine >3 mg/dL (OR 2.03, 95% CI 1.18 to 6.81) and known severe hypertension (OR 2.01, 95% CI 1.2 to 4.7) were found to be independent risk factors for minor and major complications, respectively. Conversely, we found no association of risk with the number of biopsy passes, gender, age, diagnosis, presence of haematuria before the kidney biopsy nor the degree of proteinuria.

CONCLUSIONS

Outpatient biopsy could be a valuable, safe and perhaps cost-effective method of obtaining diagnostic renal tissue in the majority of patients.

Kidney, Ureter, and Bladder Biopsy

Percutaneous urologic biopsy is a safe and effective technique and can comprise a significant proportion of the daily workload of the interventional radiologist. This article discusses the indications and rationale for the performance of renal, ureter, and bladder biopsy as well as the approach to performing such biopsies, pitfalls, and potential complications.

Risk factors and timing of native kidney biopsy complications

Background

The appropriate observation period, rate and risk factors of complications after a percutaneous renal biopsy remain debated.

Methods

We retrospectively studied native kidney biopsies performed in our institution between January 2007 and July 2011. Outpatients had either an 8- (67%) or a 24-hour (33%) observation period.

Results

312 biopsies were reviewed (287 patients), 51% of patients were female and the mean age was 54 ± 15 years. Half of these biopsies were performed in outpatients. A total of 15% of patients developed a symptomatic hematoma, 9% received a red blood cell transfusion and 1% required an angio-intervention. Eighty-four percent of the complications manifested within the first 8 h, 86% at 12 h and 94% at 24 h. Outpatients experienced significantly less complications, all manifesting within the first 8 h, 14% required an observation period longer than planned. The risk of symptomatic hematoma increased to 11, 20, 35 and 40% in patients with >200, 140-200, 100-140 and <100 × 10⁹/l platelets, respectively (p = 0.002). It also increased in hemodialysis patients (29% compared to 14%, p = 0.02). We found no association of risk with the number of biopsy passes and only a trend with needle size.

Conclusion

Symptomatic hematomas occurred in 15% of kidney biopsies and were strongly associated with platelet count and hemodialysis. Outpatients experienced fewer complications; therefore, we can conclude that same-day discharge in selected patients is safe.

Transvenous Renal Transplant Biopsy via a Transfemoral Approach

Percutaneous renal biopsy (PRB) of kidney transplants might be prevented by an elevated risk of bleeding or limited access to the allograft. In the following, we describe our initial experience with 71 transvenous renal transplant biopsies in 53 consecutive patients with unexplained reduced graft function who were considered unsuitable candidates for PRB (4.2% of all renal transplant biopsies at our institution). Biopsies were performed via the ipsilateral femoral vein with a renal biopsy set designed for transjugular renal biopsy (TJRB) of native kidneys. Positioning of the biopsy system within the transplant vein was achievable in 58 of 71 (81.7%) procedures. The specimen contained a median of 10 glomeruli (range 0-38). Tissue was considered as adequate for diagnosis in 56 of 57 (98.2%) biopsies. With respect to BANFF 50.9% of the specimen were adequate (>10 glomeruli), 47.4% marginally adequate (1-9 glomeruli) and 1.8% inadequate (no glomeruli). After implementation of real-time assessment all specimen contained glomeruli. One of the fifty-eight (1.8%) procedure-related major complications occurred (hydronephrosis requiring nephrostomy due to gross hematuria). Transfemoral renal transplant biopsy (TFRTB) is feasible and appears to be safe compared to PRB. It offers a useful new alternative for histological evaluation of graft dysfunction in selected patients with contraindications to PRB.

Bleeding complications of native kidney biopsy: a systematic review and meta-analysis

BACKGROUND

Kidney biopsy provides important information for nephrologists, but the risk of complications has not been systematically described.

STUDY DESIGN

Meta-analysis of randomized controlled trials and prospective or retrospective observational studies.

SETTING & POPULATION

Adults undergoing native kidney biopsy in an inpatient or outpatient setting.

SELECTION CRITERIA FOR STUDIES

MEDLINE indexed studies from January 1980 through June 2011; sample size of 50 or more.

INTERVENTION

Native kidney biopsy with automated biopsy device and real-time ultrasonographic guidance.

OUTCOMES

Macroscopic hematuria and erythrocyte transfusion rates and factors associated with these outcomes.

RESULTS

34 studies of 9,474 biopsies met inclusion criteria. The rate of macroscopic hematuria was 3.5% (95% CI, 2.2%-5.1%), and erythrocyte transfusion was 0.9% (95% CI, 0.4%-1.5%). Significantly higher rates of transfusion were seen with the following: 14-gauge compared with smaller needles (2.1% vs 0.5%; P = 0.009), studies with mean serum creatinine level ≥2.0 mg/dL (2.1% vs 0.4%; P = 0.02), ≥50% women (1.9% vs 0.6%; P = 0.03), and ≥10% of biopsies for acute kidney injury (1.1% vs 0.04%; P < 0.001). Higher transfusion rates also were observed in studies with a mean age of 40 years or older (1.0% vs 0.2%; P = 0.2) and mean systolic blood pressure ≥130 mm Hg (1.4% vs 0.1%; P = 0.09). Similar relationships were noted for the macroscopic hematuria rate with the same predictors, but none was statistically significant.

LIMITATIONS

Publication bias, few randomized controlled trials, and missing data.

CONCLUSIONS

Native kidney biopsy using automated biopsy devices and real-time ultrasonography is associated with a relatively small risk of macroscopic hematuria and erythrocyte transfusion requirement. Using smaller gauge needles may lower complication rates. Patient selection may affect outcome because studies with higher serum creatinine levels, more women, and higher rates of acute kidney injury had higher complication rates. Future studies should further evaluate risk factors for complications.

[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.

Outpatient versus inpatient observation after percutaneous native kidney biopsy: a cost minimization study

BACKGROUND/AIMS

Percutaneous kidney biopsy (PKB) is the primary diagnostic tool for kidney disease. Outpatient 'day surgery' (ODS) following PKB in low-risk patients has previously been described as a safe alternative to inpatient observation (IO). This study aims to determine if ODS is less costly compared to IO while accounting for all institutional costs (IC) associated with post-PKB complications, including death.

METHODS

A cost minimization study was performed using decision analysis methodology which models relative costs in relation to outcome probabilities yielding an optimum decision. The potential outcomes included major complications (bleeding requiring blood transfusion or advanced intervention), minor complications (bleeding or pain requiring additional observation), and death. Probabilities were obtained from the published literature and a base case was selected. IC were obtained for all complications from institutional activity-based cost estimates. The base case assumed a complication rate of 10% with major bleeding occurring in 2.5% of patients (for both arms) and death in 0.1 and 0.15% of IO and ODS patients, respectively.

RESULTS

ODS costs USD 1,394 per biopsy compared to USD 1,800 for IO inclusive of all complications. IC for ODS remain less when overall complications <20%, major complications <5.5%, and IC per death <USD 1.125 million. ODS remained favored through sensitivity analysis.

CONCLUSION

Outpatient management after PKB for low-risk patients costs less from the institutional perspective compared to IO, inclusive of complications and death. ODS should be considered for low-risk patients undergoing native kidney biopsy.

Clinicopathological Spectrum of Renal Biopsies in Children

BACKGROUND

Renal biopsy has revolutionized the study of glomerular diseases. A retrospective analysis of 104 consecutive renal biopsies performed in children at a tertiary care referral centre over five years is presented.

METHODS

All the biopsies were performed non-ultrasound guided by a single consultant nephrologist. Trucut needles were used in the initial few years and a Magnum biopsy gun (Bard) over subsequent three years. There were 66 boys and 38 girls.

RESULT

A male predominance occurred in the older and younger patients. The male: female ratio was 2.2:1, 1:1, and 2.7:1 for the age groups below five years, 5-10 years and above 10 years respectively. All patients tolerated the biopsy well and success rate was 94%. There were minimal complications in the form of post biopsy haematuria (33.3%). Haematuria was mild in most of the cases and settled down within 24 hours. None required transfusion. However, 60% patients had mild discomfort in the form of local pain. There was no mortality, infection or renal loss. The most common indication for a kidney biopsy was nephrotic syndrome. Out of 104 biopsies, 85 were in children with nephrotic syndrome. The commonest primary renal pathology was mesangial proliferative glomerulonephritis (38%), minimal change disease (19%), focal segmental glomerulosclerosis (15%) and membranoproliferative glomerulonephritis (7%).

CONCLUSION

Renal biopsy is a safe procedure in experienced hands and the commonest indication for a biopsy in children remains nephrotic syndrome.

Renal biopsy practice in France: results of a nationwide study

BACKGROUND

Although several risk factors associated with complications after renal biopsy (RB) have been identified, the gold standard for RB procedures remains to be defined. Practices vary widely among nephrologists, depending on personal experience and the availability of particular techniques. The purpose of our study was to depict the main aspects of the practice of RB in adults in France.

METHODS

Members of the Société de Néphrologie in France were asked to participate in 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 centres) 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 <10 per year. Transjugular renal biopsy 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 haemorrhagic risk factors, management of patients with antiplatelet agents and haemorrhagic risk factors, and radiological guidance. Early discharge (<12 h) was the rule in 3 (4.1%) units for native kidney biopsies and in 10 (28.6%) units for graft biopsies.

CONCLUSIONS

Our study is the first to provide a representative picture of 'everyday' RB practices in a country. Important variations in procedures were observed. Our study may represent a preliminary step for the elaboration of guidelines for all aspects of RB practices.

The value of post-biopsy ultrasound in predicting complications after percutaneous renal biopsy of native kidneys

BACKGROUND

Clinically significant bleeding complications occur in >30% of patients undergoing percutaneous renal biopsy (PRB) of native kidneys and can be severe in up to 10% of patients. A noninvasive measure that would reliably predict which patients will do well with an uncomplicated post-biopsy course or which patients may be at risk of developing a clinically significant complication is in great demand.

METHODS

PRB of native kidneys was performed in 162 adult patients from February 2002 through February 2007 using real-time ultrasound and automated needle. Renal ultrasound (US) was performed at 1-h post-PRB to assess biopsy-related bleeding. Patients were observed for 24 h post-PRB to monitor clinically apparent biopsy-related complications. The value of the post-biopsy ultrasound in predicting complications was assessed.

RESULTS

A clinically apparent complication was observed in 26 (16%) patients post-PRB (13 minor not requiring any intervention and 13 major requiring intervention). In patients with complicated courses, a haematoma at 1 h was seen in 77% (69% with minor and 87% with major complications). However, only 27 (20%) of 136 patients without complications (P < 0.0001) had a haematoma at 1 h. The presence of a haematoma 1-h post-PRB had a sensitivity of 77%, specificity of 80%, positive predictive value of 43% but a negative predictive value of 95% for predicting clinical complications.

CONCLUSIONS

We find that with the use of renal ultrasound 1-h post-PRB, the absence of perinephric bleeding is predictive of an uncomplicated course while the presence of a perinephric haematoma is not reliably predictive of a clinically significant complication post-renal biopsy.

The renal biopsy

CONTEXT

The first renal biopsy was carried out more than a century ago, but its widespread introduction into clinical use, beginning in the 1950s, helped develop nephrology into the powerful subspecialty of internal medicine that it is today. In the past 25 years, the use of the spring-loaded biopsy gun, in combination with newer visualization techniques, including ultrasound and computed axial tomography scanning, has led to greater tissue yield and to a much lower risk of complication. During this same time, our understanding of renal pathology has increased many fold. Correct fixation and processing of renal biopsy tissue is critical, and the laboratory must be skilled with renal biopsy light microscopy, immunohistochemistry, and transmission electron microscopy preparation.

OBJECTIVES

To provide an overview of the renal biopsy, including the techniques and its complications, and to summarize proper laboratory methods for processing renal biopsy tissue.

DATA SOURCES

This article is based on a review of the literature and on the experience of the author.

CONCLUSIONS

The experienced nephropathologist, knowledgeable in both renal medicine and pathology and thus able to correlate subtle tissue-derived information with appropriate clinical data, remains the most important key to the development of an accurate clinicopathologic diagnosis.

Risk management of renal biopsy: 1387 cases over 30 years in a single centre

BACKGROUND

Although renal biopsy is largely employed, even in old patients with systemic diseases, few clinical studies have addressed its risk management. We aimed to obtain a comprehensive assessment of safety/utility ratio of percutaneous renal biopsy.

PATIENTS AND METHODS

Retrospective review of all the 1387 patients who consecutively underwent renal biopsy in a single centre over three decades (1973-2002) was made, with calculation of complications, multivariate logistical analyses to evaluate risk factors of complications, and rate of alteration of clinical hypotheses by pathological diagnosis.

RESULTS

There were no deaths and five major complications, (0.36%). One nephrectomy (0.07%), two surgical revisions (0.1%) and two arterial-venous fistulae (0.1%). There were also 337 minor bleeding complications (24.2%) (16.4% gross haematuria and 7.8% clinically relevant haematomas needing at least prolonged bed rest). Multivariate analyses demonstrated that the risk for complications was significantly increased by systemic autoimmune diseases with odds ratio (OR) 2.06, 95% confidence interval (CI)=1.40-3.01, end-stage kidney/acute-tubular necrosis (OR 2.96, 95% CI=1.19-7.30), and prolonged bleeding time test (BTT) (OR 1.87, 95% CI=1.17-2.83). Among the 1288 cases in which a clinical hypothesis before renal biopsy was recorded, renal pathology changed previous diagnoses in 423/1,288 (32.8%) of cases.

CONCLUSIONS

Risk assessment demonstrates that renal biopsy is a useful procedure with a low incidence of serious complications. Platelet function is the only modifiable factor significantly related to bleeding complications, suggesting the need for a more standardized alternative to the BTT. Platelet function should be evaluated to select low-risk patients for renal biopsy as 'a day case procedure', in order to build adequate risk management strategies.