{"paper_id":"10d99781-e1e6-4bc4-9b97-4ac0bb67b026","body_text":"Pediatric native and transplant kidney biopsies: complications and risk factors | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Pediatric native and transplant kidney biopsies: complications and risk factors Ravjot Dhatt, Fangchao Linda Ding, Jessica Tang, Manraj Heran, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7336091/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 09 Mar, 2026 Read the published version in Pediatric Nephrology → Version 1 posted 5 You are reading this latest preprint version Abstract Background: Kidney biopsies are common diagnostic procedures. Risk factors for biopsy complications in children are not well delineated. The objective of our study is to assess complication rates in pediatric native and transplant kidney biopsies, and associated clinical and technical risk factors. Methods: Our retrospective study at BC Children’s Hospital (Vancouver, Canada) included 404 biopsies performed on 239 patients from 2010–2018. Data was obtained through patient chart review. Minor complications were defined as perinephric hematomas ≥ 2 cm or labelled as at least “moderate”, arteriovenous fistula, or pseudoaneurysm. Major complications were defined as complication requiring blood transfusion, embolization, or surgery. Results: There were 32 biopsy complications (8%) of which one was a major complication. The most common complication was hematoma in native kidneys, and arteriovenous fistula in transplant kidneys. Complications rates were significantly higher in children < 3 years of age (22%, p = 0.046), female patients (11%, p = 0.048), patients with eGFR ≤ 30 ml/min/1.73m 2 (17%, p = 0.025), hemoglobin < 10g/dL (16%, p = 0.002), vasculitis (15%, p = 0.004), and native kidney biopsies (11%, p = 0.027). Most technical factors such as number of biopsies per patient, cortical tangential vs parallel approach, training level, kidney location, and sedation methods were not associated with increased complication rates. Conclusions: Kidney biopsies are a relatively safe procedure, especially in transplant patients. Specific patient populations (children < 3 years, patients with low eGFR, anemia, and vasculitis) may be at higher risk of complications. Standardization of biopsy protocol and complication definition will enhance consistency of outcome reporting, and allow evidence-based improvement in biopsy practices. Children paediatric biopsy transplant complication Figures Figure 1 Introduction Percutaneous kidney biopsies are widely used diagnostic procedures in both native and transplant kidneys. In Canada, these biopsies are performed by interventional and non-interventional radiologists as well as pediatric nephrologists. Complications from kidney biopsies are variable, ranging from small perinephric hematomas requiring no intervention to bleeding requiring transfusion and/or surgical intervention In adult patients, reported complication rates are up to 11% for native kidneys [ 1 ] and 3.2% for transplant kidneys [ 2 ]. Risk factors for complications include female sex, eGFR < 30ml/min/1.73m 2 , low baseline hemoglobin [ 3 ], younger [ 4 ] or older age [ 5 ], elevated blood urea nitrogen (BUN), thrombocytopenia, prior kidney transplant, and use of anticoagulation [ 5 ]. Compared to adults, pediatric kidney biopsies are potentially more difficult due to variations in size [ 6 ]. In pediatric patients, complication rates have been as high as 42% [ 7 ] in native kidneys, and 16.1% in transplant kidneys [ 8 ]. Studies assessing risk factors for biopsy complications in the pediatric population are limited. Reported risk factors are male sex, low weight for height [ 9 ] and transplant biopsies performed for clinical indications (as opposed to surveillance biopsies). Introduction of real-time ultrasound-guided kidney biopsies has led to improved tissue sample adequacy and fewer complications overall [ 10 ]. However, lack of standardization of biopsy protocol along with variability in the definition of complications and post biopsy monitoring has led to inconsistent reporting, making assessment of biopsy adequacy and complications within- and between centres challenging. The objective of the current study is to define complication rates in pediatric native and transplant kidney biopsies, as well as to identify associated clinical and technical risk factors. Methods This retrospective, single center cohort study was performed at BC Children’s Hospital (BCCH) in Vancouver, British Columbia, Canada. An updated biopsy list from the Division of Nephrology at BCCH identified patients that met the inclusion criteria: all native and transplant kidney biopsies performed in our institution between January 2010-August 2018. If a patient underwent multiple biopsies, all biopsies were included in the analysis. Data was obtained from patient chart review and the BCCH Picture Archive and Communicating System. Data obtained included clinical characteristics such as: date of birth, age at time of procedure, sex, height, weight, pre-biopsy hemoglobin, platelet, international normalized ratio (INR), activated partial thromboplastin time (aPTT), creatinine, and biopsy indication. Technical characteristics were also recorded, such as: location of the kidney, biopsy operator, type of sedation, biopsy needle/system utilized, number of passes, approach utilized (cortical tangential or perpendicular), follow-up ultrasound findings. Other parameters assessed were: number of glomeruli, biopsy diagnosis, presence of complications and management required. A cortical tangential approach was defined as: needle path paralleling the outer capsule of the kidney as much as possible, coursing in the cortex approximately one-third to one half the distance from the outer capsule to the sinus fat, with the tip of the needle directed away from the renal hilum [ 11 ]. A cortical perpendicular approach was defined as: needle path creating a 90 degree or slightly obtuse angle with the outer capsule of the kidney, coursing in the cortex and performed either in long or short axis and in the upper or lower pole to avoid the renal hilum. Procedural images were reviewed with interventional radiologists to determine approach. All biopsies were performed by Interventional Radiologists at our institution. Biopsies were performed under ultrasound guidance with 17-gauge core biopsy needles (BioPince or Bard core biopsy systems, depending on operator preference). Complications were defined based on guidance from the literature in combination with local inter-departmental discussion between nephrologists and interventional radiologists (IR) at BCCH. Complications were divided into two categories: minor and major complications (Table 1 ). Minor complications encompassed those requiring ‘no intervention’ and included perirenal hematomas ≥ 2 cm or reported as at least “moderate” in size, arteriovenous fistulas (AVF), or pseudoaneurysm. The numerical cut-off of ≥ 2 cm was chosen based on the most commonly utilized threshold for defining a significant perirenal hematoma in a pediatric patient post kidney biopsy [ 12 – 14 ]. Major complications encompassed those requiring an ‘intervention’ such as packed red blood cell (pRBC) transfusion, embolization, nephrostomy or surgery. Table 1 Definition of complications Minor Complication No intervention Major Complication Any complication requiring intervention Perirenal hematomas ≥ 2 cm or labelled as at least “moderate” pRBC Transfusion Arteriovenous Fistula Embolization Pseudoaneurysm Surgery pRBC − packed red blood cell . Stata (version SE 14.1. College Station, TX: StataCorp LP) was used for analysis. Summary statistics were expressed as median ± interquartile range or absolute range for continuous variables, and count (percentage) for categorical variables. The difference between median of continuous variables were assessed using Mann Whitney U Test. The difference in proportions between different subgroups was compared using Chi squared and Fisher’s exact tests. Kidney biopsy procedure A standardized biopsy protocol was followed at BCCH to minimize risk of complications. No formal imaging is required prior to the biopsy, although vast majority had pre-existing kidney ultrasound studies completed. Prior to the procedure, available bloodwork is reviewed, and consent is obtained. The patient is positioned prone for native kidney or supine for transplant kidney biopsies. Conscious sedation (or, rarely, general anesthesia) is provided by anesthesiologists. All biopsies are performed by the IR under ultrasound guidance with adequacy of samples checked by the pathology technician using an in-room microscope. The choice of probes used depends on patient size and operator preference. Preprocedural ultrasound is performed, assessing the location, morphology, and appearance of the target kidney, as well as to identify any new or pre-existing pathologic findings (ex: arterio-venous fistula or hydronephrosis). It is also used to identify a safe path for the biopsy and assess the length of the biopsy needle throw. An informal post-procedural ultrasound is performed by the IR in the procedural suite to assess for immediate complications. The patient is then transferred to the medical day unit and monitored 4–6 hours for clinical signs of complications. The patient is discharged by the nephrologist if there is no hemodynamic stability or evidence of persistent gross hematuria. No formal routine ultrasounds are completed immediately post biopsy unless clinically indicated. At our institution, transplant kidneys undergo routine surveillance biopsies at 3,6,12, and 24 months post-transplant, and additional biopsies as clinically indicated. Transplant kidneys also undergo routine surveillance ultrasounds every 2 years. Results A total of 402 biopsies were performed on 232 patients. There were 201 native kidney biopsies and 201 transplant biopsies. The median age at the time of biopsy was 14.2 years (range 8 months – 20.6 years). There were 121 males (52%) and 111 females (48%). For native kidney biopsies, the most common indication for biopsy was suspected vasculitis (92 biopsies, 46%), followed by nephrotic syndrome (n = 59, 29%), other glomerulonephritis such as immunoglobulin A (IgA) nephropathy, post infectious glomerulonephritis, atypical hemolytic uremic syndrome, or membranoproliferative glomerulonephritis (n = 34, 17%), severe acute kidney injury (n = 13, 6%), and other causes including Alport syndrome and non-nephrotic range proteinuria (n = 6, 3%). There were 130 transplant biopsies done for clinical indications (70%) and 61 surveillance biopsies (30%). Overall, there were 32 biopsy complications (8%), of which 31 were minor complications (97%) and one was a major complication requiring blood transfusion. It occurred in a 5-year-old female patient with history of acute lymphoblastic leukemia, subsequent bone marrow transplant, and had a native kidney biopsy for work up of nephrotic syndrome and elevated creatinine. She was mildly thrombocytopenic (platelet 101x10 9 /L) at the time of the biopsy. Clinical characteristics associated with biopsy complications Median age at biopsy was similar between patients that developed a biopsy complication (13 years, range 2–21 years) and patients that did not develop a complication (14 years, range 0.7–21 years). However, a greater proportion of children < 3 years of age developed complications (22%) compared to older patients (7%, p = 0.046) (Table 2 ). Increased complication rates were also observed with female compared to male patients (11% vs 6%, p = 0.048), patients with eGFR ≤ 30 ml/min/1.73m2 compared to higher eGFR (17% vs 7%, P = 0.025), and native kidney biopsies compared to transplant kidney biopsies (11% vs 5%, p = 0.027). Coagulation parameters such as elevated INR and aPTT were not significantly associated with development of complications. However, in line with guideline recommendations for hematologic criteria to minimize biopsy complications, only 9 patients with an abnormal INR underwent a biopsy, with 8 of those having an INR between 1.2–1.3. Similarly, only 9 patients had an abnormal aPTT, of which only 2 had an aPTT > 70 seconds. Only 7 patients had platelets < 75 x 10 9 /L; however they did not have significantly higher rates of complications compared to those with higher platelet count (P = 0.46). Patients with anemia pre-biopsy (hemoglobin < 10g/dL) had significantly higher rates of complications (16%) compared to those with higher hemoglobin (6%, p = 0.002). Patients with vasculitis (systemic lupus erythematosus (SLE), anti-neutrophil cytoplasmic antibody (ANCA) vasculitis, IgA vasculitis, anti-glomerular basement membrane disease) were more likely to develop complications (15%) than patients whose biopsies were done for other indications (6%, p = 0.004). There was no difference in complication rates between surveillance and indication transplant biopsies (2% vs 7%, p = 0.17). There was no association between number of biopsy per patient and complication rate (p = 0.28). Table 2 Clinical risk factors associated with kidney biopsy complication Complications No complications p N % N % Age at time of biopsy, y 0.046 0–2 4 22% 14 78% ≥ 3 28 7% 356 93% Sex 0.048 Male 12 6% 206 94% Female 20 11% 164 89% BMI 0.12 Normal weight 23 10% 202 90% Overweight 1 2% 54 98% Obese 6 10% 57 90% eGFR 0.025 > 30ml/min/1.73m2 21 7% 278 93% ≤ 30ml/min/1.73m2 8 17% 40 83% INR > 1.1 0.91 Yes 2 8% 23 92% No 25 9% 263 91% aPTT > 35 seconds 1 Yes 1 8% 11 92% No 24 9% 255 91% Hemoglobin < 10g/dL 0.002 Yes 14 16% 72 84% No 17 6% 269 94% Platelets < 75x10^9/L 0.46 Yes 1 14% 6 86% No 30 8% 332 92% Indications 0.004 Vasculitis 14 15% 78 85% All other indications 18 6% 284 94% Type of kidney 0.027 Native 22 11% 179 89% Transplant 10 5% 191 95% y – years. BMI – body mass index. Normal weight – weight < 85 percentile for age. Overweight – weight 85 − <95 percentile for age. Obese – weight ≥ 95 percentile for age. INR – international normalized ratio. aPTT – activated prothrombin time . Technical characteristics associated with biopsy complication Biopsies were performed by five interventional radiologists within the institution, with 53 biopsies (13%) performed by trainees (Table 3 ). Conscious sedation was used for 376 (94%) of the biopsies, and general anesthesia used for 26 (6%) biopsies. The biopsy system utilized was based on operator comfort and preference. 68% of biopsies were performed using the BioPince biopsy system and 31% of biopsies were performed using the Bard biopsy system. The cortical tangential approach was used for 351 (89%) of the biopsies, with a 7% complication rate. Cortical parallel approach was used for 42 (11%) of the biopsies, with a 10% complication rate. Table 3 Technical risk factors associated with biopsy complication Complications No complications p N % N % Biopsy number per patient 0.28 1 20 9% 211 91% 2 4 6% 67 94% 3 6 13% 39 87% ≥ 4 2 4% 53 96% Number of core samples 0.35 1 0 0% 1 100% 2 10 6% 154 94% 3 22 11% 176 89% ≥ 4 0 0% 37 100% Glomeruli per biopsy, M (range) 37 (30–54) 28 (21–38) 0.0003 Technique 0.63 Cortical tangential 26 7% 325 93% Cortical perpendicular 4 10% 38 90% Operator 0.95 Resident 1 6% 16 94% Fellow 3 8% 33 92% Attending 28 8% 321 92% Kidney location 0.15 Right kidney 3 10% 28 90% Left kidney 19 11% 147 89% Transplant kidney 10 5% 191 95% Sedation methods 1 Conscious sedation 29 8% 347 92% General anesthesia 2 8% 23 92% M – median . There was no statistical difference amongst most technical factors for patients with and without complications including number of biopsy and core samples per patient, cortical tangential vs parallel approach, operator training level, kidney location, and sedation methods. Biopsies associated with a complication had higher yield of glomeruli (37, interquartile range 30–54) compared to biopsies without complications (28, interquartile range 21–38, p = 0.0003). Native vs transplant kidney biopsies There were 201 native kidney and 201 transplant kidney biopsies (Table 4 ). 166/203 (82%) of native kidney biopsies were performed on the left kidney. Transplant kidneys were in the right iliac fossa, and the lower pole was targeted for 92% of biopsies. The median number of biopsies per patient was 1 (range: 1–3) in native kidneys and 2 (range: 1–11) in transplant kidneys (p < 0.001). The median number of core samples was 3 (range: 2–5) in native kidneys and 3 (range: 1–6) in transplant kidneys (p = 0.213). The median number of glomeruli obtained per biopsy was 32.5 (range: 5-177) and 27 (range: 2–80) in native and transplant kidney biopsies, respectively (p < 0.001). Table 4 Characteristics of native compared to transplant kidney biopsies Native (N = 201) Transplant (N = 201) p Number of biopsy per patient, M (range) 1 (1–3) 2 (1–11) < 0.001 Number of core samples, M (range) 3 (2–5) 3 (1–6) 0.21 Glomeruli per biopsy, M (range) 32.5 (5-177) 27 (2–80) < 0.001 Number of days from biopsy to complication finding, M (range) 0 (0–12) 8 (0-154) < 0.001 N – number. M – median. AVF – arteriovenous fistula . In native kidney biopsies, there were 22 minor complications (11% of all native kidney biopsies) and one major complication (0.5% of all native kidney biopsies, Fig. 1 ). In transplant kidney biopsies there were nine minor complications (4.5% of all transplant kidney biopsies) and no major complications. Peri-renal hematoma was the most common minor complication in the native kidney biopsies (17/22), followed by AVF (3/22), and pseudoaneurysm (1/22). In contrast, AVF was the most common complication in transplant kidneys (8/22). A statistically significant difference was observed in the time from biopsy to the detection of complications between native (median: 0 days; range: 0–12 days) and transplant kidney biopsies (median: 11 days; range 0-154 days, p < 0.001). Discussion In this retrospective review of pediatric kidney biopsies, we found that complication rate, especially complications requiring interventions, is low for both native and transplant kidneys. Assessment of complications following kidney biopsy is challenging due to absence of standardized definition for what constitutes a clinically relevant complication. The British Association of Paediatric Nephrology (BAPN) carried out a 13-center prospective audit with the goal of assessing complication rates and standardizing kidney biopsy practices [ 6 ]. In this audit, major complications were defined as macroscopic hematuria, requirement for blood transfusion, surgical intervention, delay in discharge or readmission for observation [ 6 ]. While 10.4% of the patients were classified as having a major complication, only 4 out of the 39 patients with gross hematuria required a blood transfusion, raising the question whether gross hematuria should be included as a major biopsy complication. In most studies, major complications were typically defined as those necessitating an intervention, such as blood transfusion or surgical procedure, with reported incidence rates consistently low (0 to 4.5%) [ 3 , 5 , 10 , 15 ]. The definition of minor complications were even more variable, often including complications such as gross hematuria, AVF, hematoma of various sizes, or any adverse event that does not require transfusion or surgical intervention [ 4 , 16 ]. Perinephric hematomas can be quite common post biopsy, as high as 63.2% [ 17 ]. However, most are unlikely to be clinically relevant. We elected to include only hematomas of ≥ 2 cm as hematomas of that size may be a predictive factor for more significant hemoglobin decrease [ 14 ] and is the most commonly used size cut off for significant perirenal hematomas in the literature for pediatric kidney biopsies [ 12 – 14 ]. In our study, risk factors for complications include age < 3 years, eGFR < 30ml/min/1.73m 2 , female sex, hemoglobin < 10g/dL, and vasculitis. Age related effect on complication rates have not been noted previously in the pediatric population [ 9 , 13 , 15 ]. A prior study by Rianthavorn et al found higher incidence of macroscopic haematuria in children < 5 years of age; however the difference was not statistically significant [ 9 ]. In our study, age related difference was only noted in those aged < 3 years, suggesting that only very young children are at higher risk of complications. Decreased eGFR have been reported as a risk factor for biopsy complication in both adult [ 3 , 18 , 19 ] and pediatric studies [ 15 ], with a relative risk of 16 for major complications when eGFR is < 30ml/min/1.73m 2 . This may be related to increased risk of uremic bleeding in severe kidney injury. Baseline hemoglobin of < 10g/dL was the only hematological risk factor associated with higher complication rates in our study, in agreement with prior adult studies [ 3 , 20 ]. Presence of anemia increases risk of transfusion, and can impair primary hemostasis [ 21 ]. No significant effect of platelet level or abnormal coagulation parameters, such as INR and aPTT, was detected in our study. However, there were very few patients that underwent a kidney biopsy with significant thrombocytopenia or abnormal coagulation parameters, and our study is likely underpowered to detect any differences. In our study, patients with vasculitis had the highest risk of kidney biopsy complication. This is consistent with multiple studies in adult patients that demonstrated increased risk of bleeding post kidney biopsy in vasculitis patients [ 20 , 22 , 23 ]. Conversely, a prior pediatric study found no difference in complication rates between children with SLE, acute glomerulonephritis, steroid-resistant nephrotic syndrome, or other indications [ 9 ]. It is unclear whether the potentially increased risk for vasculitis patients is related to the vasculitic process itself, or the comorbidities they often present with such as anemia, decreased eGFR, and hypertension. The influence of sex on biopsy complications has had conflicting findings in the literature. Female sex had been associated with increased risk of biopsy complication in multiple adult studies [ 3 , 4 , 19 ]. Whereas in a pediatric study male sex was associated with development of perirenal haematoma [ 9 ]. It was postulated that the increased risk to women may be related to lower baseline creatinine for women, reflecting in a falsely reassuring eGFR, as well as smaller kidney size in women [ 4 , 19 ]. However, sex related difference in creatinine or kidney size may not be a significant factor in the pediatric population, especially in pre-pubescents. In the pediatric population, sex differences in the epidemiology of kidney conditions leading to biopsy, some of which are associated with an increased bleeding risk, may have a more pronounced impact. For instance, vasculitis conditions such as SLE carries a higher bleeding risk and is more prevalent in females. Existing literature on the effect of biopsy technique on complication rates is limited, and to our knowledge, this is the first study to assess complication rates based on biopsy techniques in both native and transplant kidneys in the pediatric population. A recent study by Pettit et al found that biopsies completed by pediatric nephrologists, using the cortical perpendicular approach and the Bard system, on lightly sedated children, had more perinephric haematomas than biopsies completed by interventional radiologists using the cortical tangential approach and mostly the BioPince system, on children sedated with general anesthesia [ 7 ]. There was no difference in major complication rates [ 7 ]. However, these variables were not assessed individually. The safety and efficacy of the cortical tangential approach was previously assessed in an adult transplant population; however there was no comparison with a control group [ 11 ]. It is thought that the tangential approach may reduce risk of hematuria by aiming away from the renal sinus and collecting system [ 11 ]. However, in our study there was no difference in complication rates between the cortical tangential and cortical perpendicular group. Similar to previous adult studies, we did not find an effect of the number of cores or passes on complication rate [ 15 , 24 ]. At our institution, nearly all biopsies were performed under conscious sedation as administered by our Anesthesiology Department, which is in sharp contrast to the multi-center study published by the BAPN, where the majority of centers used general anesthesia (1). Performing this procedure under conscious sedation is logistically beneficial for patients and hospitals. However, managing the depth of breathing in patients under conscious sedation for native kidney biopsy can be difficult as some patients can have deep inspiratory excursions, making the needle throw more hazardous. We did not find a difference in complication rates between biopsies completed under conscious sedation and general anesthesia, and conscious sedation should be considered for percutaneous kidney biopsy in centres with adequate expertise. Although all biopsies were performed by IRs or radiology trainees at our institution, global practice patterns are quite variable with many biopsies performed by pediatric nephrologists as well [ 6 , 11 – 13 , 15 ]. The multi-center study by the BAPN demonstrated no differences in complication rates between radiologists and nephrologists (1). We believe that pediatric kidney biopsies should be performed by physicians that have the appropriate training, image guidance skills, and are comfortable with the procedure, whether that be an IR, general radiologist or pediatric nephrologist. In our study, native kidney biopsies had higher complication rates compared to transplant biopsies, despite transplant kidney recipients having more routine surveillance ultrasounds that can detect asymptomatic complications. Native kidney biopsies are considered to be more technically challenging as the position of the kidneys are deeper, particularly in larger patients, as opposed to the more superficially located transplant kidneys. However, the vast majority of complications in native kidney biopsies were perirenal hematomas, whose clinical significance is up for debate [ 15 , 25 ]. The most common complication following transplant kidney biopsies was an AVF. The increased prevalence of AVFs after transplant kidney biopsies has been demonstrated in other studies [ 12 , 26 ], and may be related to increased number of biopsies and potential effect of immunosuppressive medications on tissue healing. However, as all AVFs were found incidentally, and transplant recipients more frequently received routine surveillance ultrasounds compared to non-transplant patients, there is a high likelihood of surveillance bias. Given the frequency of AVF following transplant kidney biopsies, Franke et al. recommends a Doppler ultrasound in transplant patients prior to the biopsy to rule out any pre-existing AVFs from earlier procedures, as well as after the biopsy to identify any fistulas resulting from the procedure. There were no difference in complication rates between surveillance and indication biopsies in transplant recipients, similar to a prior study by Schwarz et al [ 27 ]. The difference in timing of complication identification between native and transplant kidney biopsies is likely related to the relatively asymptomatic nature of most complications and the use of routine surveillance ultrasounds in transplant recipients. The detection of minor complication depends highly on the quality of post-biopsy assessments. Our study is the first pediatric study to assess a comprehensive set of clinical and technical risk factors in both native and transplant kidneys in a relatively large cohort of pediatric patients. However, there are some limitations to this study. As a single center study at a large tertiary centre, results may not be generalizable to other pediatric centres, especially smaller centres where kidney biopsies are not commonly conducted, or centres where pediatric nephrologist are conducting the biopsy. Overall complication rates were low, and hence our ability to adequately perform multivariable analyses and assess interactions between risk factors were limited. Conclusion Ultrasound guided kidney biopsies appear to be a relatively safe procedure in the pediatric population with a low incidence of complications overall. Clinical risk factors associated with increased complication risk include age < 3 years, eGFR < 30ml/min/1.73m2, female sex, hemoglobin < 10g/dL, vasculitis, and native kidney biopsies. Most technical characteristics had no effect on complication rate. Native and transplant biopsy complications differ in regards to incidence, type of complication, and timing of identification. Standardization of biopsy practices is important for surveillance of complications rates and implementation of quality improvement measures to enhance biopsy safety. Declarations Data availability The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request. Author contributions: All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Ravjot Dhatt, FangChao Linda Ding, and Jessica Tang. The first draft of the manuscript was written by Ravjot Dhatt. The final draft of the manuscript was written by FangChao Linda Ding. Manraj Heran and Cherry Mammen reviewed and edited the final manuscript. Funding: No funding was received for conducting this study. The authors have no relevant financial or non-financial interests to disclose. Ethics approval Approval was obtained from the University of British Columbia Children’s and Women’s Research Ethics Board (H18-01785). The procedures used in this study adhere to the tenets of the Declaration of Helsinki. References Kajawo S, Ekrikpo U, Moloi MW, et al (2021) A Systematic Review of Complications Associated With Percutaneous Native Kidney Biopsies in Adults in Low- and Middle-Income Countries. Kidney Int Rep 6:78–90. https://doi.org/10.1016/j.ekir.2020.10.019 Ho QY, Lim CC, Tan HZ, et al (2022) Complications of Percutaneous Kidney Allograft Biopsy: Systematic Review and Meta-analysis. Transplantation 106:1497. https://doi.org/10.1097/TP.0000000000004033 Palsson R, Short SAP, Kibbelaar ZA, et al (2020) Bleeding Complications After Percutaneous Native Kidney Biopsy: Results From the Boston Kidney Biopsy Cohort. Kidney Int Rep 5:511–518. https://doi.org/10.1016/j.ekir.2020.01.012 Peters B, Andersson Y, Stegmayr B, et al (2014) A study of clinical complications and risk factors in 1001 native and transplant kidney biopsies in Sweden. Acta Radiol 55:890–896. https://doi.org/10.1177/0284185113506190 Morgan TA, Chandran S, Burger IM, et al (2016) Complications of Ultrasound-Guided Renal Transplant Biopsies. Am J Transplant 16:1298–1305. https://doi.org/10.1111/ajt.13622 Hussain F, Mallik M, Marks SD, et al (2010) Renal biopsies in children: current practice and audit of outcomes. Nephrol Dial Transplant 25:485–489. https://doi.org/10.1093/ndt/gfp434 Pettit C, Kanagaratnam R, Coughlan F, et al (2022) Kidney biopsy adequacy and complications in children — does technique matter? Eur J Pediatr 181:2677. https://doi.org/10.1007/s00431-022-04464-1 J V, J M, L V, et al (2003) Safety and risk stratification of percutaneous biopsies of adult-sized renal allografts in infant and older pediatric recipients. Transplantation 76:. https://doi.org/10.1097/01.TP.0000076097.90123.21 Rianthavorn P, Kerr SJ, Chiengthong K (2014) Safety of paediatric percutaneous native kidney biopsy and factors predicting bleeding complications. Nephrology 19:143–148. https://doi.org/10.1111/nep.12184 Id M, P M, J B, M A (2007) Percutaneous renal biopsy: comparison of blind and real-time ultrasound-guided technique. Semin Dial 20:. https://doi.org/10.1111/j.1525-139X.2007.00295.x Patel MD, Phillips CJ, Young SW, et al (2010) US-guided Renal Transplant Biopsy: Efficacy of a Cortical Tangential Approach. Radiology 256:290–296. https://doi.org/10.1148/radiol.10091793 M F, A K, C T, et al (2014) Ultrasound-guided percutaneous renal biopsy in 295 children and adolescents: role of ultrasound and analysis of complications. PloS One 9:. https://doi.org/10.1371/journal.pone.0114737 R S, B M, B S, S M (2016) A prospective audit of complications in 100 consecutive pediatric percutaneous renal biopsies done under real-time ultrasound guidance. Indian J Nephrol 26:. https://doi.org/10.4103/0971-4065.171232 Ishikawa E, Nomura S, Hamaguchi T, et al (2009) Ultrasonography as a predictor of overt bleeding after renal biopsy. Clin Exp Nephrol 13:325–331. https://doi.org/10.1007/s10157-009-0165-7 Tøndel C, Vikse BE, Bostad L, Svarstad E (2012) Safety and Complications of Percutaneous Kidney Biopsies in 715 Children and 8573 Adults in Norway 1988–2010. Clin J Am Soc Nephrol CJASN 7:1591–1597. https://doi.org/10.2215/CJN.02150212 Jiang SH-T, Karpe KM, Talaulikar GS (2011) Safety and predictors of complications of renal biopsy in the outpatient setting. Clin Nephrol 76:464–469. https://doi.org/10.5414/cn107128 Kersnik Levart T, Kenig A, Buturović Ponikvar J, et al (2001) Real-time ultrasound-guided renal biopsy with a biopsy gun in children: safety and efficacy. Acta Paediatr Oslo Nor 1992 90:1394–1397. https://doi.org/10.1080/08035250152708789 Whittier WL, Korbet SM (2004) Timing of complications in percutaneous renal biopsy. J Am Soc Nephrol JASN 15:142–147. https://doi.org/10.1097/01.asn.0000102472.37947.14 Corapi KM, Chen JLT, Balk EM, Gordon CE (2012) Bleeding complications of native kidney biopsy: a systematic review and meta-analysis. Am J Kidney Dis Off J Natl Kidney Found 60:62–73. https://doi.org/10.1053/j.ajkd.2012.02.330 Manno C, Strippoli GFM, Arnesano L, et al (2004) Predictors of bleeding complications in percutaneous ultrasound-guided renal biopsy. Kidney Int 66:1570–1577. https://doi.org/10.1111/j.1523-1755.2004.00922.x Thakar S, Gabarin N, Gupta A, et al (2021) Anemia-Induced Bleeding in Patients with Platelet Disorders. Transfus Med Rev 35:22–28. https://doi.org/10.1016/j.tmrv.2021.06.001 Lees JS, McQuarrie EP, Mordi N, et al (2017) Risk factors for bleeding complications after nephrologist-performed native renal biopsy. Clin Kidney J 10:573–577. https://doi.org/10.1093/ckj/sfx012 Halimi J-M, Gatault P, Longuet H, et al (2020) Major Bleeding and Risk of Death after Percutaneous Native Kidney Biopsies. Clin J Am Soc Nephrol CJASN 15:1587–1594. https://doi.org/10.2215/CJN.14721219 Torres Muñoz A, Valdez-Ortiz R, González-Parra C, et al (2011) Percutaneous renal biopsy of native kidneys: efficiency, safety and risk factors associated with major complications. Arch Med Sci AMS 7:823–831. https://doi.org/10.5114/aoms.2011.25557 Mendelssohn DC, Cole EH (1995) Outcomes of percutaneous kidney biopsy, including those of solitary native kidneys. Am J Kidney Dis Off J Natl Kidney Found 26:580–585. https://doi.org/10.1016/0272-6386(95)90592-8 Bilge I, Rozanes I, Acunas B, et al (1999) Endovascular treatment of arteriovenous fistulas complicating percutaneous renal biopsy in three paediatric cases. Nephrol Dial Transplant Off Publ Eur Dial Transpl Assoc - Eur Ren Assoc 14:2726–2730. https://doi.org/10.1093/ndt/14.11.2726 Schwarz A, Gwinner W, Hiss M, et al (2005) Safety and Adequacy of Renal Transplant Protocol Biopsies. Am J Transplant 5:1992–1996. https://doi.org/10.1111/j.1600-6143.2005.00988.x Cite Share Download PDF Status: Published Journal Publication published 09 Mar, 2026 Read the published version in Pediatric Nephrology → Version 1 posted Editorial decision: Major Revisions Needed 04 Sep, 2025 Reviewers agreed at journal 18 Aug, 2025 Reviewers invited by journal 18 Aug, 2025 Editor assigned by journal 18 Aug, 2025 First submitted to journal 17 Aug, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-7336091\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":false,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":502138204,\"identity\":\"63b40b9d-bd0f-4fb9-ba7c-23c6d76a9398\",\"order_by\":0,\"name\":\"Ravjot Dhatt\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Vancouver General Hospital\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Ravjot\",\"middleName\":\"\",\"lastName\":\"Dhatt\",\"suffix\":\"\"},{\"id\":502138205,\"identity\":\"5b7d77ca-c7d9-4584-813d-8541e81d44ab\",\"order_by\":1,\"name\":\"Fangchao Linda Ding\",\"email\":\"data:image/png;base64,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\",\"orcid\":\"https://orcid.org/0000-0002-1704-518X\",\"institution\":\"University of Calgary\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Fangchao\",\"middleName\":\"Linda\",\"lastName\":\"Ding\",\"suffix\":\"\"},{\"id\":502138206,\"identity\":\"3d432d0c-0e9e-458e-88bd-b1423c59d58e\",\"order_by\":2,\"name\":\"Jessica Tang\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"The University of British Columbia\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Jessica\",\"middleName\":\"\",\"lastName\":\"Tang\",\"suffix\":\"\"},{\"id\":502138207,\"identity\":\"ebfd8b07-85f5-4518-bf30-f599ff5e842f\",\"order_by\":3,\"name\":\"Manraj Heran\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"The University of British Columbia\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Manraj\",\"middleName\":\"\",\"lastName\":\"Heran\",\"suffix\":\"\"},{\"id\":502138208,\"identity\":\"93f36417-b45c-416c-8cbb-2242ba33596d\",\"order_by\":4,\"name\":\"Sanjay Maroo\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"The University of British Columbia\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Sanjay\",\"middleName\":\"\",\"lastName\":\"Maroo\",\"suffix\":\"\"},{\"id\":502138209,\"identity\":\"7ba8c2a0-25c6-4b7c-bf2b-02e3f90e01ef\",\"order_by\":5,\"name\":\"Stephen Ho\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"The University of British Columbia\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Stephen\",\"middleName\":\"\",\"lastName\":\"Ho\",\"suffix\":\"\"},{\"id\":502138210,\"identity\":\"21de3575-16ce-4d55-ac81-bf2e19cc98b8\",\"order_by\":6,\"name\":\"Cherry Mammen\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"The University of British Columbia\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Cherry\",\"middleName\":\"\",\"lastName\":\"Mammen\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2025-08-09 23:12:55\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-7336091/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-7336091/v1\",\"draftVersion\":[],\"editorialEvents\":[{\"content\":\"https://doi.org/10.1007/s00467-026-07174-0\",\"type\":\"published\",\"date\":\"2026-03-09T15:57:54+00:00\"}],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":89988058,\"identity\":\"86bae48c-5fd2-4d9a-91b9-f2d46b7da894\",\"added_by\":\"auto\",\"created_at\":\"2025-08-27 07:02:43\",\"extension\":\"png\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":149845,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003e\\u003cstrong\\u003eType of complication in native and transplant kidney biopsies\\u003c/strong\\u003e\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage1.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7336091/v1/ec940cad1fbeb9372a385b0f.png\"},{\"id\":104739312,\"identity\":\"3684942f-1b63-4587-8f91-5cd5451d2aa8\",\"added_by\":\"auto\",\"created_at\":\"2026-03-16 16:01:41\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":1114795,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7336091/v1/ede031e0-c6a4-4c54-a511-e63b4f9a9841.pdf\"}],\"financialInterests\":\"\",\"formattedTitle\":\"Pediatric native and transplant kidney biopsies: complications and risk factors\",\"fulltext\":[{\"header\":\"Introduction\",\"content\":\"\\u003cp\\u003ePercutaneous kidney biopsies are widely used diagnostic procedures in both native and transplant kidneys. In Canada, these biopsies are performed by interventional and non-interventional radiologists as well as pediatric nephrologists. Complications from kidney biopsies are variable, ranging from small perinephric hematomas requiring no intervention to bleeding requiring transfusion and/or surgical intervention In adult patients, reported complication rates are up to 11% for native kidneys [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e] and 3.2% for transplant kidneys [\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e]. Risk factors for complications include female sex, eGFR\\u0026thinsp;\\u0026lt;\\u0026thinsp;30ml/min/1.73m\\u003csup\\u003e2\\u003c/sup\\u003e, low baseline hemoglobin [\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e], younger [\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e] or older age [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e], elevated blood urea nitrogen (BUN), thrombocytopenia, prior kidney transplant, and use of anticoagulation [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e]. Compared to adults, pediatric kidney biopsies are potentially more difficult due to variations in size [\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e]. In pediatric patients, complication rates have been as high as 42% [\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e] in native kidneys, and 16.1% in transplant kidneys [\\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e]. Studies assessing risk factors for biopsy complications in the pediatric population are limited. Reported risk factors are male sex, low weight for height [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e] and transplant biopsies performed for clinical indications (as opposed to surveillance biopsies). Introduction of real-time ultrasound-guided kidney biopsies has led to improved tissue sample adequacy and fewer complications overall [\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e]. However, lack of standardization of biopsy protocol along with variability in the definition of complications and post biopsy monitoring has led to inconsistent reporting, making assessment of biopsy adequacy and complications within- and between centres challenging.\\u003c/p\\u003e\\u003cp\\u003eThe objective of the current study is to define complication rates in pediatric native and transplant kidney biopsies, as well as to identify associated clinical and technical risk factors.\\u003c/p\\u003e\"},{\"header\":\"Methods\",\"content\":\"\\u003cp\\u003eThis retrospective, single center cohort study was performed at BC Children\\u0026rsquo;s Hospital (BCCH) in Vancouver, British Columbia, Canada.\\u003c/p\\u003e\\u003cp\\u003eAn updated biopsy list from the Division of Nephrology at BCCH identified patients that met the inclusion criteria: all native and transplant kidney biopsies performed in our institution between January 2010-August 2018. If a patient underwent multiple biopsies, all biopsies were included in the analysis.\\u003c/p\\u003e\\u003cp\\u003eData was obtained from patient chart review and the BCCH Picture Archive and Communicating System. Data obtained included clinical characteristics such as: date of birth, age at time of procedure, sex, height, weight, pre-biopsy hemoglobin, platelet, international normalized ratio (INR), activated partial thromboplastin time (aPTT), creatinine, and biopsy indication. Technical characteristics were also recorded, such as: location of the kidney, biopsy operator, type of sedation, biopsy needle/system utilized, number of passes, approach utilized (cortical tangential or perpendicular), follow-up ultrasound findings. Other parameters assessed were: number of glomeruli, biopsy diagnosis, presence of complications and management required. A cortical tangential approach was defined as: needle path paralleling the outer capsule of the kidney as much as possible, coursing in the cortex approximately one-third to one half the distance from the outer capsule to the sinus fat, with the tip of the needle directed away from the renal hilum [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e]. A cortical perpendicular approach was defined as: needle path creating a 90 degree or slightly obtuse angle with the outer capsule of the kidney, coursing in the cortex and performed either in long or short axis and in the upper or lower pole to avoid the renal hilum. Procedural images were reviewed with interventional radiologists to determine approach. All biopsies were performed by Interventional Radiologists at our institution. Biopsies were performed under ultrasound guidance with 17-gauge core biopsy needles (BioPince or Bard core biopsy systems, depending on operator preference).\\u003c/p\\u003e\\u003cp\\u003eComplications were defined based on guidance from the literature in combination with local inter-departmental discussion between nephrologists and interventional radiologists (IR) at BCCH. Complications were divided into two categories: minor and major complications (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e). Minor complications encompassed those requiring \\u0026lsquo;no intervention\\u0026rsquo; and included perirenal hematomas\\u0026thinsp;\\u0026ge;\\u0026thinsp;2 cm or reported as at least \\u0026ldquo;moderate\\u0026rdquo; in size, arteriovenous fistulas (AVF), or pseudoaneurysm. The numerical cut-off of \\u0026ge;\\u0026thinsp;2 cm was chosen based on the most commonly utilized threshold for defining a significant perirenal hematoma in a pediatric patient post kidney biopsy [\\u003cspan additionalcitationids=\\\"CR13\\\" citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e]. Major complications encompassed those requiring an \\u0026lsquo;intervention\\u0026rsquo; such as packed red blood cell (pRBC) transfusion, embolization, nephrostomy or surgery.\\u003c/p\\u003e\\u003cp\\u003e\\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab1\\\" border=\\\"1\\\"\\u003e\\u003ccaption language=\\\"En\\\"\\u003e\\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 1\\u003c/div\\u003e\\u003cdiv class=\\\"CaptionContent\\\"\\u003e\\u003cp\\u003eDefinition of complications\\u003c/p\\u003e\\u003c/div\\u003e\\u003c/caption\\u003e\\u003ccolgroup cols=\\\"2\\\"\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e\\u003cthead\\u003e\\u003ctr\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eMinor Complication\\u003c/p\\u003e\\u003cp\\u003eNo intervention\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003eMajor Complication\\u003c/p\\u003e\\u003cp\\u003eAny complication requiring intervention\\u003c/p\\u003e\\u003c/th\\u003e\\u003c/tr\\u003e\\u003c/thead\\u003e\\u003ctbody\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003ePerirenal hematomas\\u0026thinsp;\\u0026ge;\\u0026thinsp;2 cm or labelled as at least \\u0026ldquo;moderate\\u0026rdquo;\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003epRBC Transfusion\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eArteriovenous Fistula\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003eEmbolization\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003ePseudoaneurysm\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003eSurgery\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003c/tbody\\u003e\\u003c/colgroup\\u003e\\u003ctfoot\\u003e\\u003ctr\\u003e\\u003ctd colspan=\\\"2\\\"\\u003e\\u003csub\\u003epRBC \\u0026minus; packed red blood cell\\u003c/sub\\u003e.\\u003c/td\\u003e\\u003c/tr\\u003e\\u003c/tfoot\\u003e\\u003c/table\\u003e\\u003c/div\\u003e\\u003c/p\\u003e\\u003cp\\u003eStata (version SE 14.1. College Station, TX: StataCorp LP) was used for analysis. Summary statistics were expressed as median\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;interquartile range or absolute range for continuous variables, and count (percentage) for categorical variables. The difference between median of continuous variables were assessed using Mann Whitney U Test. The difference in proportions between different subgroups was compared using Chi squared and Fisher\\u0026rsquo;s exact tests.\\u003c/p\\u003e\\u003cp\\u003eKidney biopsy procedure\\u003c/p\\u003e\\u003cp\\u003eA standardized biopsy protocol was followed at BCCH to minimize risk of complications. No formal imaging is required prior to the biopsy, although vast majority had pre-existing kidney ultrasound studies completed. Prior to the procedure, available bloodwork is reviewed, and consent is obtained. The patient is positioned prone for native kidney or supine for transplant kidney biopsies. Conscious sedation (or, rarely, general anesthesia) is provided by anesthesiologists. All biopsies are performed by the IR under ultrasound guidance with adequacy of samples checked by the pathology technician using an in-room microscope. The choice of probes used depends on patient size and operator preference. Preprocedural ultrasound is performed, assessing the location, morphology, and appearance of the target kidney, as well as to identify any new or pre-existing pathologic findings (ex: arterio-venous fistula or hydronephrosis). It is also used to identify a safe path for the biopsy and assess the length of the biopsy needle throw. An informal post-procedural ultrasound is performed by the IR in the procedural suite to assess for immediate complications. The patient is then transferred to the medical day unit and monitored 4\\u0026ndash;6 hours for clinical signs of complications. The patient is discharged by the nephrologist if there is no hemodynamic stability or evidence of persistent gross hematuria. No formal routine ultrasounds are completed immediately post biopsy unless clinically indicated. At our institution, transplant kidneys undergo routine surveillance biopsies at 3,6,12, and 24 months post-transplant, and additional biopsies as clinically indicated. Transplant kidneys also undergo routine surveillance ultrasounds every 2 years.\\u003c/p\\u003e\"},{\"header\":\"Results\",\"content\":\"\\u003cp\\u003eA total of 402 biopsies were performed on 232 patients. There were 201 native kidney biopsies and 201 transplant biopsies. The median age at the time of biopsy was 14.2 years (range 8 months \\u0026ndash; 20.6 years). There were 121 males (52%) and 111 females (48%). For native kidney biopsies, the most common indication for biopsy was suspected vasculitis (92 biopsies, 46%), followed by nephrotic syndrome (n\\u0026thinsp;=\\u0026thinsp;59, 29%), other glomerulonephritis such as immunoglobulin A (IgA) nephropathy, post infectious glomerulonephritis, atypical hemolytic uremic syndrome, or membranoproliferative glomerulonephritis (n\\u0026thinsp;=\\u0026thinsp;34, 17%), severe acute kidney injury (n\\u0026thinsp;=\\u0026thinsp;13, 6%), and other causes including Alport syndrome and non-nephrotic range proteinuria (n\\u0026thinsp;=\\u0026thinsp;6, 3%). There were 130 transplant biopsies done for clinical indications (70%) and 61 surveillance biopsies (30%). Overall, there were 32 biopsy complications (8%), of which 31 were minor complications (97%) and one was a major complication requiring blood transfusion. It occurred in a 5-year-old female patient with history of acute lymphoblastic leukemia, subsequent bone marrow transplant, and had a native kidney biopsy for work up of nephrotic syndrome and elevated creatinine. She was mildly thrombocytopenic (platelet 101x10\\u003csup\\u003e9\\u003c/sup\\u003e/L) at the time of the biopsy.\\u003c/p\\u003e\\n\\u003ch3\\u003eClinical characteristics associated with biopsy complications\\u003c/h3\\u003e\\n\\u003cp\\u003eMedian age at biopsy was similar between patients that developed a biopsy complication (13 years, range 2\\u0026ndash;21 years) and patients that did not develop a complication (14 years, range 0.7\\u0026ndash;21 years). However, a greater proportion of children\\u0026thinsp;\\u0026lt;\\u0026thinsp;3 years of age developed complications (22%) compared to older patients (7%, p\\u0026thinsp;=\\u0026thinsp;0.046) (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e). Increased complication rates were also observed with female compared to male patients (11% vs 6%, p\\u0026thinsp;=\\u0026thinsp;0.048), patients with eGFR\\u0026thinsp;\\u0026le;\\u0026thinsp;30 ml/min/1.73m2 compared to higher eGFR (17% vs 7%, P\\u0026thinsp;=\\u0026thinsp;0.025), and native kidney biopsies compared to transplant kidney biopsies (11% vs 5%, p\\u0026thinsp;=\\u0026thinsp;0.027). Coagulation parameters such as elevated INR and aPTT were not significantly associated with development of complications. However, in line with guideline recommendations for hematologic criteria to minimize biopsy complications, only 9 patients with an abnormal INR underwent a biopsy, with 8 of those having an INR between 1.2\\u0026ndash;1.3. Similarly, only 9 patients had an abnormal aPTT, of which only 2 had an aPTT\\u0026thinsp;\\u0026gt;\\u0026thinsp;70 seconds. Only 7 patients had platelets\\u0026thinsp;\\u0026lt;\\u0026thinsp;75 x 10\\u003csup\\u003e9\\u003c/sup\\u003e/L; however they did not have significantly higher rates of complications compared to those with higher platelet count (P\\u0026thinsp;=\\u0026thinsp;0.46). Patients with anemia pre-biopsy (hemoglobin\\u0026thinsp;\\u0026lt;\\u0026thinsp;10g/dL) had significantly higher rates of complications (16%) compared to those with higher hemoglobin (6%, p\\u0026thinsp;=\\u0026thinsp;0.002). Patients with vasculitis (systemic lupus erythematosus (SLE), anti-neutrophil cytoplasmic antibody (ANCA) vasculitis, IgA vasculitis, anti-glomerular basement membrane disease) were more likely to develop complications (15%) than patients whose biopsies were done for other indications (6%, p\\u0026thinsp;=\\u0026thinsp;0.004). There was no difference in complication rates between surveillance and indication transplant biopsies (2% vs 7%, p\\u0026thinsp;=\\u0026thinsp;0.17). There was no association between number of biopsy per patient and complication rate (p\\u0026thinsp;=\\u0026thinsp;0.28).\\u003c/p\\u003e\\u003cp\\u003e\\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab2\\\" border=\\\"1\\\"\\u003e\\u003ccaption language=\\\"En\\\"\\u003e\\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 2\\u003c/div\\u003e\\u003cdiv class=\\\"CaptionContent\\\"\\u003e\\u003cp\\u003eClinical risk factors associated with kidney biopsy complication\\u003c/p\\u003e\\u003c/div\\u003e\\u003c/caption\\u003e\\u003ccolgroup cols=\\\"6\\\"\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c5\\\" colnum=\\\"5\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c6\\\" colnum=\\\"6\\\"\\u003e\\u003c/div\\u003e\\u003cthead\\u003e\\u003ctr\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"1\\\" rowspan=\\\"2\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003eComplications\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003eNo complications\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003ep\\u003c/p\\u003e\\u003c/th\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003eN\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e%\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003eN\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e%\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e\\u003c/tr\\u003e\\u003c/thead\\u003e\\u003ctbody\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eAge at time of biopsy, y\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.046\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e0\\u0026ndash;2\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e4\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e22%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e14\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e78%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u0026ge;\\u0026thinsp;3\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e28\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e7%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e356\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e93%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eSex\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.048\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eMale\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e12\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e6%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e206\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e94%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eFemale\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e20\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e11%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e164\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e89%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eBMI\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.12\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eNormal weight\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e23\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e10%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e202\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e90%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eOverweight\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e1\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e2%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e54\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e98%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eObese\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e6\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e10%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e57\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e90%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eeGFR\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.025\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u0026gt;\\u0026thinsp;30ml/min/1.73m2\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e21\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e7%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e278\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e93%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u0026le;\\u0026thinsp;30ml/min/1.73m2\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e8\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e17%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e40\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e83%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eINR\\u0026thinsp;\\u0026gt;\\u0026thinsp;1.1\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.91\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eYes\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e2\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e8%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e23\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e92%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eNo\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e25\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e9%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e263\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e91%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eaPTT\\u0026thinsp;\\u0026gt;\\u0026thinsp;35 seconds\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e1\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eYes\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e1\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e8%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e11\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e92%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eNo\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e24\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e9%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e255\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e91%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eHemoglobin\\u0026thinsp;\\u0026lt;\\u0026thinsp;10g/dL\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.002\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eYes\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e14\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e16%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e72\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e84%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eNo\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e17\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e6%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e269\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e94%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003ePlatelets\\u0026thinsp;\\u0026lt;\\u0026thinsp;75x10^9/L\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.46\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eYes\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e1\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e14%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e6\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e86%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eNo\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e30\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e8%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e332\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e92%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eIndications\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.004\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eVasculitis\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e14\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e15%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e78\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e85%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eAll other indications\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e18\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e6%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e284\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e94%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eType of kidney\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.027\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eNative\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e22\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e11%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e179\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e89%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eTransplant\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e10\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e5%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e191\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e95%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003c/tbody\\u003e\\u003c/colgroup\\u003e\\u003ctfoot\\u003e\\u003ctr\\u003e\\u003ctd colspan=\\\"6\\\"\\u003e\\u003csub\\u003ey \\u0026ndash; years. BMI \\u0026ndash; body mass index. Normal weight \\u0026ndash; weight \\u0026lt; 85 percentile for age. Overweight \\u0026ndash; weight 85 \\u0026minus; \\u0026lt;95 percentile for age. Obese \\u0026ndash; weight \\u0026ge; 95 percentile for age. INR \\u0026ndash; international normalized ratio. aPTT \\u0026ndash; activated prothrombin time\\u003c/sub\\u003e.\\u003c/td\\u003e\\u003c/tr\\u003e\\u003c/tfoot\\u003e\\u003c/table\\u003e\\u003c/div\\u003e\\u003c/p\\u003e\\n\\u003ch3\\u003eTechnical characteristics associated with biopsy complication\\u003c/h3\\u003e\\n\\u003cp\\u003eBiopsies were performed by five interventional radiologists within the institution, with 53 biopsies (13%) performed by trainees (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e). Conscious sedation was used for 376 (94%) of the biopsies, and general anesthesia used for 26 (6%) biopsies. The biopsy system utilized was based on operator comfort and preference. 68% of biopsies were performed using the BioPince biopsy system and 31% of biopsies were performed using the Bard biopsy system. The cortical tangential approach was used for 351 (89%) of the biopsies, with a 7% complication rate. Cortical parallel approach was used for 42 (11%) of the biopsies, with a 10% complication rate.\\u003c/p\\u003e\\u003cp\\u003e\\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab3\\\" border=\\\"1\\\"\\u003e\\u003ccaption language=\\\"En\\\"\\u003e\\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 3\\u003c/div\\u003e\\u003cdiv class=\\\"CaptionContent\\\"\\u003e\\u003cp\\u003eTechnical risk factors associated with biopsy complication\\u003c/p\\u003e\\u003c/div\\u003e\\u003c/caption\\u003e\\u003ccolgroup cols=\\\"6\\\"\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c5\\\" colnum=\\\"5\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c6\\\" colnum=\\\"6\\\"\\u003e\\u003c/div\\u003e\\u003cthead\\u003e\\u003ctr\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"1\\\" rowspan=\\\"2\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003eComplications\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003eNo complications\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003ep\\u003c/p\\u003e\\u003c/th\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003eN\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e%\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003eN\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e%\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e\\u003c/tr\\u003e\\u003c/thead\\u003e\\u003ctbody\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eBiopsy number per patient\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.28\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e1\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e20\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e9%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e211\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e91%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e2\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e4\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e6%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e67\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e94%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e3\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e6\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e13%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e39\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e87%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u0026ge;\\u0026thinsp;4\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e2\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e4%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e53\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e96%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eNumber of core samples\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.35\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e1\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e0\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e0%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e1\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e100%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e2\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e10\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e6%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e154\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e94%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e3\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e22\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e11%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e176\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e89%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u0026ge;\\u0026thinsp;4\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e0\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e0%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e37\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e100%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eGlomeruli per biopsy, M (range)\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e37 (30\\u0026ndash;54)\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e28 (21\\u0026ndash;38)\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.0003\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eTechnique\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.63\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eCortical tangential\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e26\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e7%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e325\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e93%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eCortical perpendicular\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e4\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e10%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e38\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e90%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eOperator\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.95\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eResident\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e1\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e6%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e16\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e94%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eFellow\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e3\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e8%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e33\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e92%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eAttending\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e28\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e8%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e321\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e92%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eKidney location\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e0.15\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eRight kidney\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e3\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e10%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e28\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e90%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eLeft kidney\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e19\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e11%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e147\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e89%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eTransplant kidney\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e10\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e5%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e191\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e95%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eSedation methods\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u003cp\\u003e1\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eConscious sedation\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e29\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e8%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e347\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e92%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003eGeneral anesthesia\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e2\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e8%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e23\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u003cp\\u003e92%\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\u003c/tr\\u003e\\u003c/tbody\\u003e\\u003c/colgroup\\u003e\\u003ctfoot\\u003e\\u003ctr\\u003e\\u003ctd colspan=\\\"6\\\"\\u003e\\u003csub\\u003eM \\u0026ndash; median\\u003c/sub\\u003e.\\u003c/td\\u003e\\u003c/tr\\u003e\\u003c/tfoot\\u003e\\u003c/table\\u003e\\u003c/div\\u003e\\u003c/p\\u003e\\u003cp\\u003eThere was no statistical difference amongst most technical factors for patients with and without complications including number of biopsy and core samples per patient, cortical tangential vs parallel approach, operator training level, kidney location, and sedation methods. Biopsies associated with a complication had higher yield of glomeruli (37, interquartile range 30\\u0026ndash;54) compared to biopsies without complications (28, interquartile range 21\\u0026ndash;38, p\\u0026thinsp;=\\u0026thinsp;0.0003).\\u003c/p\\u003e\\n\\u003ch3\\u003eNative vs transplant kidney biopsies\\u003c/h3\\u003e\\n\\u003cp\\u003eThere were 201 native kidney and 201 transplant kidney biopsies (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e). 166/203 (82%) of native kidney biopsies were performed on the left kidney. Transplant kidneys were in the right iliac fossa, and the lower pole was targeted for 92% of biopsies. The median number of biopsies per patient was 1 (range: 1\\u0026ndash;3) in native kidneys and 2 (range: 1\\u0026ndash;11) in transplant kidneys (p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001). The median number of core samples was 3 (range: 2\\u0026ndash;5) in native kidneys and 3 (range: 1\\u0026ndash;6) in transplant kidneys (p\\u0026thinsp;=\\u0026thinsp;0.213). The median number of glomeruli obtained per biopsy was 32.5 (range: 5-177) and 27 (range: 2\\u0026ndash;80) in native and transplant kidney biopsies, respectively (p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001).\\u003c/p\\u003e\\u003cp\\u003e\\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab4\\\" border=\\\"1\\\"\\u003e\\u003ccaption language=\\\"En\\\"\\u003e\\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 4\\u003c/div\\u003e\\u003cdiv class=\\\"CaptionContent\\\"\\u003e\\u003cp\\u003eCharacteristics of native compared to transplant kidney biopsies\\u003c/p\\u003e\\u003c/div\\u003e\\u003c/caption\\u003e\\u003ccolgroup cols=\\\"4\\\"\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e\\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e\\u003cthead\\u003e\\u003ctr\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003eNative (N\\u0026thinsp;=\\u0026thinsp;201)\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003eTransplant (N\\u0026thinsp;=\\u0026thinsp;201)\\u003c/p\\u003e\\u003c/th\\u003e\\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003ep\\u003c/p\\u003e\\u003c/th\\u003e\\u003c/tr\\u003e\\u003c/thead\\u003e\\u003ctbody\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eNumber of biopsy per patient, M (range)\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e1 (1\\u0026ndash;3)\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e2 (1\\u0026ndash;11)\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eNumber of core samples, M (range)\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e3 (2\\u0026ndash;5)\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e3 (1\\u0026ndash;6)\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e0.21\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eGlomeruli per biopsy, M (range)\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e32.5 (5-177)\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e27 (2\\u0026ndash;80)\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003ctr\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u003cp\\u003e\\u003cb\\u003eNumber of days from biopsy to complication finding, M (range)\\u003c/b\\u003e\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u003cp\\u003e0 (0\\u0026ndash;12)\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u003cp\\u003e8 (0-154)\\u003c/p\\u003e\\u003c/td\\u003e\\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e\\u003cp\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003c/p\\u003e\\u003c/td\\u003e\\u003c/tr\\u003e\\u003c/tbody\\u003e\\u003c/colgroup\\u003e\\u003ctfoot\\u003e\\u003ctr\\u003e\\u003ctd colspan=\\\"4\\\"\\u003e\\u003csub\\u003eN \\u0026ndash; number. M \\u0026ndash; median. AVF \\u0026ndash; arteriovenous fistula\\u003c/sub\\u003e.\\u003c/td\\u003e\\u003c/tr\\u003e\\u003c/tfoot\\u003e\\u003c/table\\u003e\\u003c/div\\u003e\\u003c/p\\u003e\\u003cp\\u003eIn native kidney biopsies, there were 22 minor complications (11% of all native kidney biopsies) and one major complication (0.5% of all native kidney biopsies, Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e). In transplant kidney biopsies there were nine minor complications (4.5% of all transplant kidney biopsies) and no major complications. Peri-renal hematoma was the most common minor complication in the native kidney biopsies (17/22), followed by AVF (3/22), and pseudoaneurysm (1/22). In contrast, AVF was the most common complication in transplant kidneys (8/22). A statistically significant difference was observed in the time from biopsy to the detection of complications between native (median: 0 days; range: 0\\u0026ndash;12 days) and transplant kidney biopsies (median: 11 days; range 0-154 days, p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001).\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\"},{\"header\":\"Discussion\",\"content\":\"\\u003cp\\u003eIn this retrospective review of pediatric kidney biopsies, we found that complication rate, especially complications requiring interventions, is low for both native and transplant kidneys. Assessment of complications following kidney biopsy is challenging due to absence of standardized definition for what constitutes a clinically relevant complication. The British Association of Paediatric Nephrology (BAPN) carried out a 13-center prospective audit with the goal of assessing complication rates and standardizing kidney biopsy practices [\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e]. In this audit, major complications were defined as macroscopic hematuria, requirement for blood transfusion, surgical intervention, delay in discharge or readmission for observation [\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e]. While 10.4% of the patients were classified as having a major complication, only 4 out of the 39 patients with gross hematuria required a blood transfusion, raising the question whether gross hematuria should be included as a major biopsy complication. In most studies, major complications were typically defined as those necessitating an intervention, such as blood transfusion or surgical procedure, with reported incidence rates consistently low (0 to 4.5%) [\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e]. The definition of minor complications were even more variable, often including complications such as gross hematuria, AVF, hematoma of various sizes, or any adverse event that does not require transfusion or surgical intervention [\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e]. Perinephric hematomas can be quite common post biopsy, as high as 63.2% [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e]. However, most are unlikely to be clinically relevant. We elected to include only hematomas of \\u0026ge;\\u0026thinsp;2 cm as hematomas of that size may be a predictive factor for more significant hemoglobin decrease [\\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e] and is the most commonly used size cut off for significant perirenal hematomas in the literature for pediatric kidney biopsies [\\u003cspan additionalcitationids=\\\"CR13\\\" citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003eIn our study, risk factors for complications include age\\u0026thinsp;\\u0026lt;\\u0026thinsp;3 years, eGFR\\u0026thinsp;\\u0026lt;\\u0026thinsp;30ml/min/1.73m\\u003csup\\u003e2\\u003c/sup\\u003e, female sex, hemoglobin\\u0026thinsp;\\u0026lt;\\u0026thinsp;10g/dL, and vasculitis. Age related effect on complication rates have not been noted previously in the pediatric population [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e]. A prior study by Rianthavorn et al found higher incidence of macroscopic haematuria in children\\u0026thinsp;\\u0026lt;\\u0026thinsp;5 years of age; however the difference was not statistically significant [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e]. In our study, age related difference was only noted in those aged\\u0026thinsp;\\u0026lt;\\u0026thinsp;3 years, suggesting that only very young children are at higher risk of complications. Decreased eGFR have been reported as a risk factor for biopsy complication in both adult [\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e] and pediatric studies [\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e], with a relative risk of 16 for major complications when eGFR is \\u0026lt;\\u0026thinsp;30ml/min/1.73m\\u003csup\\u003e2\\u003c/sup\\u003e. This may be related to increased risk of uremic bleeding in severe kidney injury.\\u003c/p\\u003e\\u003cp\\u003eBaseline hemoglobin of \\u0026lt;\\u0026thinsp;10g/dL was the only hematological risk factor associated with higher complication rates in our study, in agreement with prior adult studies [\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e]. Presence of anemia increases risk of transfusion, and can impair primary hemostasis [\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e]. No significant effect of platelet level or abnormal coagulation parameters, such as INR and aPTT, was detected in our study. However, there were very few patients that underwent a kidney biopsy with significant thrombocytopenia or abnormal coagulation parameters, and our study is likely underpowered to detect any differences.\\u003c/p\\u003e\\u003cp\\u003eIn our study, patients with vasculitis had the highest risk of kidney biopsy complication. This is consistent with multiple studies in adult patients that demonstrated increased risk of bleeding post kidney biopsy in vasculitis patients [\\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR22\\\" class=\\\"CitationRef\\\"\\u003e22\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e23\\u003c/span\\u003e]. Conversely, a prior pediatric study found no difference in complication rates between children with SLE, acute glomerulonephritis, steroid-resistant nephrotic syndrome, or other indications [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e]. It is unclear whether the potentially increased risk for vasculitis patients is related to the vasculitic process itself, or the comorbidities they often present with such as anemia, decreased eGFR, and hypertension.\\u003c/p\\u003e\\u003cp\\u003eThe influence of sex on biopsy complications has had conflicting findings in the literature. Female sex had been associated with increased risk of biopsy complication in multiple adult studies [\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e]. Whereas in a pediatric study male sex was associated with development of perirenal haematoma [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e]. It was postulated that the increased risk to women may be related to lower baseline creatinine for women, reflecting in a falsely reassuring eGFR, as well as smaller kidney size in women [\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e]. However, sex related difference in creatinine or kidney size may not be a significant factor in the pediatric population, especially in pre-pubescents. In the pediatric population, sex differences in the epidemiology of kidney conditions leading to biopsy, some of which are associated with an increased bleeding risk, may have a more pronounced impact. For instance, vasculitis conditions such as SLE carries a higher bleeding risk and is more prevalent in females.\\u003c/p\\u003e\\u003cp\\u003eExisting literature on the effect of biopsy technique on complication rates is limited, and to our knowledge, this is the first study to assess complication rates based on biopsy techniques in both native and transplant kidneys in the pediatric population. A recent study by Pettit et al found that biopsies completed by pediatric nephrologists, using the cortical perpendicular approach and the Bard system, on lightly sedated children, had more perinephric haematomas than biopsies completed by interventional radiologists using the cortical tangential approach and mostly the BioPince system, on children sedated with general anesthesia [\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e]. There was no difference in major complication rates [\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e]. However, these variables were not assessed individually. The safety and efficacy of the cortical tangential approach was previously assessed in an adult transplant population; however there was no comparison with a control group [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e]. It is thought that the tangential approach may reduce risk of hematuria by aiming away from the renal sinus and collecting system [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e]. However, in our study there was no difference in complication rates between the cortical tangential and cortical perpendicular group. Similar to previous adult studies, we did not find an effect of the number of cores or passes on complication rate [\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003eAt our institution, nearly all biopsies were performed under conscious sedation as administered by our Anesthesiology Department, which is in sharp contrast to the multi-center study published by the BAPN, where the majority of centers used general anesthesia (1). Performing this procedure under conscious sedation is logistically beneficial for patients and hospitals. However, managing the depth of breathing in patients under conscious sedation for native kidney biopsy can be difficult as some patients can have deep inspiratory excursions, making the needle throw more hazardous. We did not find a difference in complication rates between biopsies completed under conscious sedation and general anesthesia, and conscious sedation should be considered for percutaneous kidney biopsy in centres with adequate expertise.\\u003c/p\\u003e\\u003cp\\u003eAlthough all biopsies were performed by IRs or radiology trainees at our institution, global practice patterns are quite variable with many biopsies performed by pediatric nephrologists as well [\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e, \\u003cspan additionalcitationids=\\\"CR12\\\" citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e]. The multi-center study by the BAPN demonstrated no differences in complication rates between radiologists and nephrologists (1). We believe that pediatric kidney biopsies should be performed by physicians that have the appropriate training, image guidance skills, and are comfortable with the procedure, whether that be an IR, general radiologist or pediatric nephrologist.\\u003c/p\\u003e\\u003cp\\u003eIn our study, native kidney biopsies had higher complication rates compared to transplant biopsies, despite transplant kidney recipients having more routine surveillance ultrasounds that can detect asymptomatic complications. Native kidney biopsies are considered to be more technically challenging as the position of the kidneys are deeper, particularly in larger patients, as opposed to the more superficially located transplant kidneys. However, the vast majority of complications in native kidney biopsies were perirenal hematomas, whose clinical significance is up for debate [\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e]. The most common complication following transplant kidney biopsies was an AVF. The increased prevalence of AVFs after transplant kidney biopsies has been demonstrated in other studies [\\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e26\\u003c/span\\u003e], and may be related to increased number of biopsies and potential effect of immunosuppressive medications on tissue healing. However, as all AVFs were found incidentally, and transplant recipients more frequently received routine surveillance ultrasounds compared to non-transplant patients, there is a high likelihood of surveillance bias. Given the frequency of AVF following transplant kidney biopsies, Franke et al. recommends a Doppler ultrasound in transplant patients prior to the biopsy to rule out any pre-existing AVFs from earlier procedures, as well as after the biopsy to identify any fistulas resulting from the procedure. There were no difference in complication rates between surveillance and indication biopsies in transplant recipients, similar to a prior study by Schwarz et al [\\u003cspan citationid=\\\"CR27\\\" class=\\\"CitationRef\\\"\\u003e27\\u003c/span\\u003e]. The difference in timing of complication identification between native and transplant kidney biopsies is likely related to the relatively asymptomatic nature of most complications and the use of routine surveillance ultrasounds in transplant recipients. The detection of minor complication depends highly on the quality of post-biopsy assessments.\\u003c/p\\u003e\\u003cp\\u003eOur study is the first pediatric study to assess a comprehensive set of clinical and technical risk factors in both native and transplant kidneys in a relatively large cohort of pediatric patients. However, there are some limitations to this study. As a single center study at a large tertiary centre, results may not be generalizable to other pediatric centres, especially smaller centres where kidney biopsies are not commonly conducted, or centres where pediatric nephrologist are conducting the biopsy. Overall complication rates were low, and hence our ability to adequately perform multivariable analyses and assess interactions between risk factors were limited.\\u003c/p\\u003e\"},{\"header\":\"Conclusion\",\"content\":\"\\u003cp\\u003eUltrasound guided kidney biopsies appear to be a relatively safe procedure in the pediatric population with a low incidence of complications overall. Clinical risk factors associated with increased complication risk include age\\u0026thinsp;\\u0026lt;\\u0026thinsp;3 years, eGFR\\u0026thinsp;\\u0026lt;\\u0026thinsp;30ml/min/1.73m2, female sex, hemoglobin\\u0026thinsp;\\u0026lt;\\u0026thinsp;10g/dL, vasculitis, and native kidney biopsies. Most technical characteristics had no effect on complication rate. Native and transplant biopsy complications differ in regards to incidence, type of complication, and timing of identification. Standardization of biopsy practices is important for surveillance of complications rates and implementation of quality improvement measures to enhance biopsy safety.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003eData availability\\u003c/p\\u003e\\n\\u003cp\\u003eThe datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.\\u003c/p\\u003e\\n\\u003cp\\u003eAuthor contributions:\\u003c/p\\u003e\\n\\u003cp\\u003eAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Ravjot Dhatt, FangChao Linda Ding, and Jessica Tang. The first draft of the manuscript was written by Ravjot Dhatt. The final draft of the manuscript was written by FangChao Linda Ding. Manraj Heran and Cherry Mammen reviewed and edited the final manuscript.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eFunding:\\u003c/p\\u003e\\n\\u003cp\\u003eNo funding was received for conducting this study. The authors have no relevant financial or non-financial interests to disclose.\\u003c/p\\u003e\\n\\u003cp\\u003eEthics approval\\u003c/p\\u003e\\n\\u003cp\\u003eApproval was obtained from the University of British Columbia Children’s and Women’s Research Ethics Board (H18-01785). The procedures used in this study adhere to the tenets of the Declaration of Helsinki.\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\n\\u003cli\\u003eKajawo S, Ekrikpo U, Moloi MW, et al (2021) A Systematic Review of Complications Associated With Percutaneous Native Kidney Biopsies in Adults in Low- and Middle-Income Countries. Kidney Int Rep 6:78\\u0026ndash;90. https://doi.org/10.1016/j.ekir.2020.10.019\\u003c/li\\u003e\\n\\u003cli\\u003eHo QY, Lim CC, Tan HZ, et al (2022) Complications of Percutaneous Kidney Allograft Biopsy: Systematic Review and Meta-analysis. Transplantation 106:1497. https://doi.org/10.1097/TP.0000000000004033\\u003c/li\\u003e\\n\\u003cli\\u003ePalsson R, Short SAP, Kibbelaar ZA, et al (2020) Bleeding Complications After Percutaneous Native Kidney Biopsy: Results From the Boston Kidney Biopsy Cohort. Kidney Int Rep 5:511\\u0026ndash;518. https://doi.org/10.1016/j.ekir.2020.01.012\\u003c/li\\u003e\\n\\u003cli\\u003ePeters B, Andersson Y, Stegmayr B, et al (2014) A study of clinical complications and risk factors in 1001 native and transplant kidney biopsies in Sweden. Acta Radiol 55:890\\u0026ndash;896. https://doi.org/10.1177/0284185113506190\\u003c/li\\u003e\\n\\u003cli\\u003eMorgan TA, Chandran S, Burger IM, et al (2016) Complications of Ultrasound-Guided Renal Transplant Biopsies. Am J Transplant 16:1298\\u0026ndash;1305. https://doi.org/10.1111/ajt.13622\\u003c/li\\u003e\\n\\u003cli\\u003eHussain F, Mallik M, Marks SD, et al (2010) Renal biopsies in children: current practice and audit of outcomes. Nephrol Dial Transplant 25:485\\u0026ndash;489. https://doi.org/10.1093/ndt/gfp434\\u003c/li\\u003e\\n\\u003cli\\u003ePettit C, Kanagaratnam R, Coughlan F, et al (2022) Kidney biopsy adequacy and complications in children \\u0026mdash; does technique matter? Eur J Pediatr 181:2677. https://doi.org/10.1007/s00431-022-04464-1\\u003c/li\\u003e\\n\\u003cli\\u003eJ V, J M, L V, et al (2003) Safety and risk stratification of percutaneous biopsies of adult-sized renal allografts in infant and older pediatric recipients. Transplantation 76:. https://doi.org/10.1097/01.TP.0000076097.90123.21\\u003c/li\\u003e\\n\\u003cli\\u003eRianthavorn P, Kerr SJ, Chiengthong K (2014) Safety of paediatric percutaneous native kidney biopsy and factors predicting bleeding complications. Nephrology 19:143\\u0026ndash;148. https://doi.org/10.1111/nep.12184\\u003c/li\\u003e\\n\\u003cli\\u003eId M, P M, J B, M A (2007) Percutaneous renal biopsy: comparison of blind and real-time ultrasound-guided technique. Semin Dial 20:. https://doi.org/10.1111/j.1525-139X.2007.00295.x\\u003c/li\\u003e\\n\\u003cli\\u003ePatel MD, Phillips CJ, Young SW, et al (2010) US-guided Renal Transplant Biopsy: Efficacy of a Cortical Tangential Approach. Radiology 256:290\\u0026ndash;296. https://doi.org/10.1148/radiol.10091793\\u003c/li\\u003e\\n\\u003cli\\u003eM F, A K, C T, et al (2014) Ultrasound-guided percutaneous renal biopsy in 295 children and adolescents: role of ultrasound and analysis of complications. PloS One 9:. https://doi.org/10.1371/journal.pone.0114737\\u003c/li\\u003e\\n\\u003cli\\u003eR S, B M, B S, S M (2016) A prospective audit of complications in 100 consecutive pediatric percutaneous renal biopsies done under real-time ultrasound guidance. Indian J Nephrol 26:. https://doi.org/10.4103/0971-4065.171232\\u003c/li\\u003e\\n\\u003cli\\u003eIshikawa E, Nomura S, Hamaguchi T, et al (2009) Ultrasonography as a predictor of overt bleeding after renal biopsy. Clin Exp Nephrol 13:325\\u0026ndash;331. https://doi.org/10.1007/s10157-009-0165-7\\u003c/li\\u003e\\n\\u003cli\\u003eT\\u0026oslash;ndel C, Vikse BE, Bostad L, Svarstad E (2012) Safety and Complications of Percutaneous Kidney Biopsies in 715 Children and 8573 Adults in Norway 1988\\u0026ndash;2010. Clin J Am Soc Nephrol CJASN 7:1591\\u0026ndash;1597. https://doi.org/10.2215/CJN.02150212\\u003c/li\\u003e\\n\\u003cli\\u003eJiang SH-T, Karpe KM, Talaulikar GS (2011) Safety and predictors of complications of renal biopsy in the outpatient setting. Clin Nephrol 76:464\\u0026ndash;469. https://doi.org/10.5414/cn107128\\u003c/li\\u003e\\n\\u003cli\\u003eKersnik Levart T, Kenig A, Buturović Ponikvar J, et al (2001) Real-time ultrasound-guided renal biopsy with a biopsy gun in children: safety and efficacy. Acta Paediatr Oslo Nor 1992 90:1394\\u0026ndash;1397. https://doi.org/10.1080/08035250152708789\\u003c/li\\u003e\\n\\u003cli\\u003eWhittier WL, Korbet SM (2004) Timing of complications in percutaneous renal biopsy. J Am Soc Nephrol JASN 15:142\\u0026ndash;147. https://doi.org/10.1097/01.asn.0000102472.37947.14\\u003c/li\\u003e\\n\\u003cli\\u003eCorapi KM, Chen JLT, Balk EM, Gordon CE (2012) Bleeding complications of native kidney biopsy: a systematic review and meta-analysis. Am J Kidney Dis Off J Natl Kidney Found 60:62\\u0026ndash;73. https://doi.org/10.1053/j.ajkd.2012.02.330\\u003c/li\\u003e\\n\\u003cli\\u003eManno C, Strippoli GFM, Arnesano L, et al (2004) Predictors of bleeding complications in percutaneous ultrasound-guided renal biopsy. Kidney Int 66:1570\\u0026ndash;1577. https://doi.org/10.1111/j.1523-1755.2004.00922.x\\u003c/li\\u003e\\n\\u003cli\\u003eThakar S, Gabarin N, Gupta A, et al (2021) Anemia-Induced Bleeding in Patients with Platelet Disorders. Transfus Med Rev 35:22\\u0026ndash;28. https://doi.org/10.1016/j.tmrv.2021.06.001\\u003c/li\\u003e\\n\\u003cli\\u003eLees JS, McQuarrie EP, Mordi N, et al (2017) Risk factors for bleeding complications after nephrologist-performed native renal biopsy. Clin Kidney J 10:573\\u0026ndash;577. https://doi.org/10.1093/ckj/sfx012\\u003c/li\\u003e\\n\\u003cli\\u003eHalimi J-M, Gatault P, Longuet H, et al (2020) Major Bleeding and Risk of Death after Percutaneous Native Kidney Biopsies. Clin J Am Soc Nephrol CJASN 15:1587\\u0026ndash;1594. https://doi.org/10.2215/CJN.14721219\\u003c/li\\u003e\\n\\u003cli\\u003eTorres Mu\\u0026ntilde;oz A, Valdez-Ortiz R, Gonz\\u0026aacute;lez-Parra C, et al (2011) Percutaneous renal biopsy of native kidneys: efficiency, safety and risk factors associated with major complications. Arch Med Sci AMS 7:823\\u0026ndash;831. https://doi.org/10.5114/aoms.2011.25557\\u003c/li\\u003e\\n\\u003cli\\u003eMendelssohn DC, Cole EH (1995) Outcomes of percutaneous kidney biopsy, including those of solitary native kidneys. Am J Kidney Dis Off J Natl Kidney Found 26:580\\u0026ndash;585. https://doi.org/10.1016/0272-6386(95)90592-8\\u003c/li\\u003e\\n\\u003cli\\u003eBilge I, Rozanes I, Acunas B, et al (1999) Endovascular treatment of arteriovenous fistulas complicating percutaneous renal biopsy in three paediatric cases. Nephrol Dial Transplant Off Publ Eur Dial Transpl Assoc - Eur Ren Assoc 14:2726\\u0026ndash;2730. https://doi.org/10.1093/ndt/14.11.2726\\u003c/li\\u003e\\n\\u003cli\\u003eSchwarz A, Gwinner W, Hiss M, et al (2005) Safety and Adequacy of Renal Transplant Protocol Biopsies. Am J Transplant 5:1992\\u0026ndash;1996. https://doi.org/10.1111/j.1600-6143.2005.00988.x\\u003c/li\\u003e\\n\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":false,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":true,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":true,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"pediatric-nephrology\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"pnep\",\"sideBox\":\"Learn more about [Pediatric Nephrology](http://link.springer.com/journal/467)\",\"snPcode\":\"467\",\"submissionUrl\":\"https://www.editorialmanager.com/pnep/default2.aspx\",\"title\":\"Pediatric Nephrology\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false},\"keywords\":\"Children, paediatric, biopsy, transplant, complication\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-7336091/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-7336091/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003ch2\\u003eBackground:\\u003c/h2\\u003e\\u003cp\\u003eKidney biopsies are common diagnostic procedures. Risk factors for biopsy complications in children are not well delineated. The objective of our study is to assess complication rates in pediatric native and transplant kidney biopsies, and associated clinical and technical risk factors.\\u003c/p\\u003e\\u003ch2\\u003eMethods:\\u003c/h2\\u003e\\u003cp\\u003eOur retrospective study at BC Children\\u0026rsquo;s Hospital (Vancouver, Canada) included 404 biopsies performed on 239 patients from 2010\\u0026ndash;2018. Data was obtained through patient chart review. Minor complications were defined as perinephric hematomas\\u0026thinsp;\\u0026ge;\\u0026thinsp;2 cm or labelled as at least \\u0026ldquo;moderate\\u0026rdquo;, arteriovenous fistula, or pseudoaneurysm. Major complications were defined as complication requiring blood transfusion, embolization, or surgery.\\u003c/p\\u003e\\u003ch2\\u003eResults:\\u003c/h2\\u003e\\u003cp\\u003eThere were 32 biopsy complications (8%) of which one was a major complication. The most common complication was hematoma in native kidneys, and arteriovenous fistula in transplant kidneys. Complications rates were significantly higher in children\\u0026thinsp;\\u0026lt;\\u0026thinsp;3 years of age (22%, p\\u0026thinsp;=\\u0026thinsp;0.046), female patients (11%, p\\u0026thinsp;=\\u0026thinsp;0.048), patients with eGFR\\u0026thinsp;\\u0026le;\\u0026thinsp;30 ml/min/1.73m\\u003csup\\u003e2\\u003c/sup\\u003e (17%, p\\u0026thinsp;=\\u0026thinsp;0.025), hemoglobin\\u0026thinsp;\\u0026lt;\\u0026thinsp;10g/dL (16%, p\\u0026thinsp;=\\u0026thinsp;0.002), vasculitis (15%, p\\u0026thinsp;=\\u0026thinsp;0.004), and native kidney biopsies (11%, p\\u0026thinsp;=\\u0026thinsp;0.027). Most technical factors such as number of biopsies per patient, cortical tangential vs parallel approach, training level, kidney location, and sedation methods were not associated with increased complication rates.\\u003c/p\\u003e\\u003ch2\\u003eConclusions:\\u003c/h2\\u003e\\u003cp\\u003eKidney biopsies are a relatively safe procedure, especially in transplant patients. Specific patient populations (children\\u0026thinsp;\\u0026lt;\\u0026thinsp;3 years, patients with low eGFR, anemia, and vasculitis) may be at higher risk of complications. Standardization of biopsy protocol and complication definition will enhance consistency of outcome reporting, and allow evidence-based improvement in biopsy practices.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Pediatric native and transplant kidney biopsies: complications and risk factors\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2025-08-27 07:02:39\",\"doi\":\"10.21203/rs.3.rs-7336091/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0},{\"type\":\"decision\",\"content\":\"Major Revisions Needed\",\"date\":\"2025-09-04T14:39:11+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"\",\"date\":\"2025-08-18T18:26:44+00:00\",\"index\":0,\"fulltext\":\"\"},{\"type\":\"reviewersInvited\",\"content\":\"\",\"date\":\"2025-08-18T18:14:07+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorAssigned\",\"content\":\"\",\"date\":\"2025-08-18T16:39:53+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"submitted\",\"content\":\"Pediatric Nephrology\",\"date\":\"2025-08-17T23:44:03+00:00\",\"index\":\"\",\"fulltext\":\"\"}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"pediatric-nephrology\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"pnep\",\"sideBox\":\"Learn more about [Pediatric Nephrology](http://link.springer.com/journal/467)\",\"snPcode\":\"467\",\"submissionUrl\":\"https://www.editorialmanager.com/pnep/default2.aspx\",\"title\":\"Pediatric Nephrology\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false}}],\"origin\":\"\",\"ownerIdentity\":\"7fff1289-32f5-4ad9-8dfa-fa1ecf131d5b\",\"owner\":[],\"postedDate\":\"August 27th, 2025\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"published-in-journal\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2026-03-16T16:00:56+00:00\",\"versionOfRecord\":{\"articleIdentity\":\"rs-7336091\",\"link\":\"https://doi.org/10.1007/s00467-026-07174-0\",\"journal\":{\"identity\":\"pediatric-nephrology\",\"isVorOnly\":false,\"title\":\"Pediatric Nephrology\"},\"publishedOn\":\"2026-03-09 15:57:54\",\"publishedOnDateReadable\":\"March 9th, 2026\"},\"versionCreatedAt\":\"2025-08-27 07:02:39\",\"video\":\"\",\"vorDoi\":\"10.1007/s00467-026-07174-0\",\"vorDoiUrl\":\"https://doi.org/10.1007/s00467-026-07174-0\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-7336091\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-7336091\",\"identity\":\"rs-7336091\",\"version\":[\"v1\"]},\"buildId\":\"8U1c8b4HqxoKbykW_rLl7\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}