Diagnostic utility and safety of transjugular kidney biopsy in the obese patient

Efficacy and Safety of CT-Guided Kidney Biopsy for the Diagnosis of Glomerular Diseases in Complicated Patients

INTRODUCTION

Kidney biopsy is the cornerstone for the diagnosis of glomerular diseases and to guide treatment. Percutaneous ultrasound-guided kidney biopsy is currently the gold standard to obtain cortical specimens. However, in cases where ultrasound-guided kidney biopsy is not deemed safe (obese patients, deep kidneys, or kidneys with a complicated anatomy), CT-guided kidney biopsy could be a convenient alternative to obtain renal tissue samples. The aim of this study was to describe the diagnostic yield and complications of CT-guided kidney biopsies in patients with glomerular diseases that were previously discarded for ultrasound-guided kidney biopsy.

MATERIAL AND METHODS

We performed a retrospective, single-center, observational study including patients who underwent CT-guided native kidney biopsies in our center after being contraindicated for ultrasound-guided biopsy. Patients' records were reviewed retrieving baseline characteristics and pre-biopsy clinical, laboratory parameters and concomitant medication. The biopsy needle gauge, site of puncture, and number of needle passes were recorded. The diagnostic yield was evaluated by the number of glomeruli obtained, the rate of specimens that were adequate to reach diagnosis, and the number of biopsies that had to be repeated. Complications were defined as minor (hypotension, hematoma) and major (arteriovenous fistulae, major bleeding requiring embolization, or nephrectomy). The diagnostic yield and complications were compared to ultrasound-guided native kidney biopsies performed during the same period.

RESULTS

56 CT-guided native kidney biopsies were performed during the study period. The number of glomeruli obtained per patient was 11.5 ± 6.3, which was inferior to that obtained from ultrasound-guided biopsies (14.08 ± 8.47, p < 0.05). However, the rate of specimens that were adequate to reach a diagnosis was similar (92.9% vs. 90.8%, p = 0.437). The number of needle passes was higher in CT-guided kidney biopsies (2.0 ± 0.7 vs. 1.7 ± 0.5, p < 0.05), as well as the incidence of post-biopsy perirenal asymptomatic hematomas (66.1% vs. 24.5%, p < 0.01). There were no significant differences in other post-biopsy minor complications (1.8% vs. 2.5%, p = 0.621). There were no major complications after CT-guided kidney biopsies.

CONCLUSIONS

CT-guided percutaneous kidney biopsy is a valid alternative for the diagnosis of glomerular diseases in patients with special characteristics such as obesity or deep kidneys that contraindicate ultrasound-guided biopsy. In this population, CT-guided kidney biopsies are safe and provide a high diagnostic yield, reaching a diagnosis in >90% of patients that had been previously discarded for ultrasound-guided biopsy.

Transjugular Renal Biopsy Bleeding Risk and Diagnostic Yield: A Systematic Review

This study aimed to better define the safety and efficacy of transjugular renal biopsy (TJRB) based on published studies. Seventeen published articles were included (1,321 biopsies). Complications were classified as major if they resulted in blood transfusion or additional invasive procedures. All other bleeding complications were considered minor. Diagnostic tissue was obtained in 1,193 procedures (90.3%). The total incidence of bleeding complications among 15 articles with complete data was 202 of 892 procedures (22.6%): 162 (18.2%) minor and 40 (4.5 %) major. These results show that TJRB is a feasible procedure for obtaining renal tissue for diagnosis and that most complications are self-limiting.

Laparoscopic renal biopsy

The Guidelines Project, an initiative of the Brazilian Medical Association, aims to combine information from the medical field in order to standardize producers to assist the reasoning and decision-making of doctors. The information provided through this project must be assessed and criticized by the physician responsible for the conduct that will be adopted, depending on the conditions and the clinical status of each patient.

Technical challenges of imaging & image-guided interventions in obese patients

Obese patients challenge imaging departments in their ability to obtain diagnostic quality images and to perform image-guided interventions. These technical challenges include properly accommodating large patients on imaging equipment, adjusting equipment settings to address imaging limitations, and pre-planning and preparation for image-guided interventions to insure safe and successful outcomes. Knowing and addressing these challenges can result in successfully addressing the imaging and image-guided interventions needs of obese patients.

Percutaneous ultrasound-guided renal biopsy; A comparison of axial vs. sagittal probe location

BACKGROUND

Renal biopsy is an important method for diagnosis of renal parenchymal abnormalities. Here, we compare the effectiveness and complications of percutaneous ultrasound-guided renal biopsy using axial vs. sagittal probe locations.

METHODS

In a cross-sectional survey, in 2012, patients with a nephrologist order were biopsied by a radiology resident. Renal biopsy was done on 15 patients using axial (A group) and the same number of biopsies done with sagittal probe location (S group). The two groups were compared in term of the yields and complications of each method.

RESULTS

In the A group, the ratio of glomeruli gathered to the number of obtained samples was significantly higher than in the S group. Nine patients in the A group (60%) required only two samplings, whereas 66.7% in the S group required more than two attempts. Microscopic hematuria was more common in the A; conversely, gross hematuria was less common in the A group. Meagre hematomas were more frequent in the S group. When compared with hemoglobin level before biopsy, its level 24 hours after biopsy was similar within groups.

CONCLUSION

Our study shows that percutaneous ultrasound-guided renal biopsy using axial probe provides better yield with fewer efforts and fewer serious complications.

Optimizing care for the obese patient in interventional radiology

With the rising epidemic of obesity, interventional radiologists are treating increasing numbers of obese patients, as comorbidities associated with obesity preclude more invasive treatments. These patients are at heightened risk of vascular and oncologic disease, both of which often require interventional radiology care. Obese patients pose unique challenges in imaging, technical feasibility, and periprocedural monitoring. This review describes the technical and clinical challenges posed by this population, with proposed methods to mitigate these challenges and optimize care.

Safety and effectiveness of transjugular renal biopsy: A single center study

Although percutaneous renal biopsy remains the preferred method, there are several scenarios where transjugular approach is more suitable. We hereby describe our technique of transjugular renal biopsy (TJRB) and evaluate its safety and efficacy. We retrospectively collected data regarding indication for the transjugular route of biopsy, its complications, clinical and laboratory data, and adequacy of samples from patients' records. TJRB was performed when the patients were at a high risk for bleeding from percutaneous renal biopsy. Tissue samples were assessed by a pathologist for adequacy. All patients were followed up with ultrasonographic scan 3 h after the procedure and on day 3. Nine patients (age 41.5 ± 15.4 years; 8 men) underwent 9 TJRB procedures. The procedure was technically successful in all patients. Six patients (66.67%) had a platelet count of <50,000/mcL, 2 (33.3%) had an elevated International Normalized Ratio of more than 1.4, and 1 had both. 3.2 ± 0.4 cores were obtained, with median (range) number of glomeruli being ten (7-11). Adequate renal tissue sample was obtained in all the patients. Though capsular perforation developed in 5 patients, none had major complication requiring management (endovascular treatment or blood transfusion). TJRB is a safe and effective in patients with contraindications to percutaneous biopsy.

Renal biopsy: Still a landmark for the nephrologist

Renal biopsy was performed for the first time more than one century ago, but its clinical use was routinely introduced in the 1950s. It is still an essential tool for diagnosis and choice of treatment of several primary or secondary kidney diseases. Moreover, it may help to know the expected time of end stage renal disease. The indications are represented by nephritic and/or nephrotic syndrome and rapidly progressive acute renal failure of unknown origin. Nowadays, it is performed mainly by nephrologists and radiologists using a 14-18 gauges needle with automated spring-loaded biopsy device, under real-time ultrasound guidance. Bleeding is the major primary complication that in rare cases may lead to retroperitoneal haemorrhage and need for surgical intervention and/or death. For this reason, careful evaluation of risks and benefits must be taken into account, and all procedures to minimize the risk of complications must be observed. After biopsy, an observation time of 12-24 h is necessary, whilst a prolonged observation may be needed rarely. In some cases it could be safer to use different techniques to reduce the risk of complications, such as laparoscopic or transjugular renal biopsy in patients with coagulopathy or alternative approaches in obese patients. Despite progress in medicine over the years with the introduction of more advanced molecular biology techniques, renal biopsy is still an irreplaceable tool for nephrologists.

Complications of transjugular biopsies

Transvenous biopsy was first performed in 1964 by Charles Dotter. Now routinely performed in the liver and kidney by interventional radiologists, the transjugular approach to biopsy has assumed a central role in coagulopathic patients. Major arterial complications from transjugular liver and renal biopsy are rare. In this article, the authors describe such complications in both organs that necessitated selective endovascular coil embolization.

Renal biopsy practice: What is the gold standard?

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

Transvenous Renal Transplant Biopsy via a Transfemoral Approach

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

Predicting post renal biopsy complications

At our institution, kidney biopsies are performed by an interventional nephrologist with standardized guidelines using real-time ultrasound. We hypothesized that patient factors could predict post biopsy complications. We did a retrospective review of 100 patients who underwent renal biopsy. Prebiopsy data obtained included demographics, blood pressure, laboratory studies, and kidney size. Biopsy procedure information was also recorded. Complications and post biopsy imaging was noted. A minor complication was defined as one not requiring intervention while a major complication required interventions like readmission or blood transfusion. The average age was 47 years, 41 were men, 51 were black, 30 had diabetes, 42 were obese, and 81 had hypertension. Twenty-six patients had a complication; 14 minor and 12 major including 1 nephrectomy. Factors predictive of a complication were thrombocytopenia (p=0.002) and inpatient status (p=0.04). Drop in hemoglobin at 6 hours was moderately sensitive and specific for a bleeding complication with an ROC of 0.723. Thrombocytopenia and inpatient status are risk factors for complications after renal biopsy. Serum creatinine, obesity, blood pressure, kidney size, needle size, and number of passes were not predictive of a major complication in our study.

A new method of kidney biopsy using low dose CT-guidance with coaxial trocar and bard biopsy gun

Background

To explore a new method of kidney biopsy with coaxial trocar and bard biopsy gun under low dose computed tomography (CT)-guidance and evaluate its accuracy, safety, and efficacy.

Methods

Sixty patients underwent renal biopsy under CT-guidance. They were randomly divided into two groups: group I, low dose CT-guided (120 kV and 25 or 50 mAs) and group II, standard dose CT-guided (120 kV and 250 mAs). For group I, the coaxial trocar was accurately placed adjacent to the renal capsule of the lower pole, the needle core was removed, and samples were obtained with a bard biopsy gun. For group II, the coaxial trocar was not used. Total number of passes, mean biopsy diameter, mean glomeruli per specimen, mean operation time, mean scanning time, and mean radiation dose were noted. Dose-length product (DLP) was used to calculate the radiation doses. After 24 hours of the biopsy, ultrasound was repeated to identify any subcapsular hematoma.

Results

Success rate of biopsy in group I was 100% while using low dose CT-guidance along with coaxial trocar renal. There was no statistic differences bewteen group I and II in the total number of passes, mean biopsy diameter, mean glomeruli per specimen and mean time of operation and CT scanning. The average DLP of group I was lower as compared to the value of group II (p <0.05).

Conclusions

Kidney biopsy using coaxial trocar and bard biopsy gun under low dose CT was an accurate, simple and safe method for diagnosis and treatment of kidney diseases. It can be used for repeat and multiple biopsies, particularly suitable for obese and renal atrophy patients in whom the kidneys are difficult to image.

Complications of the percutaneous kidney biopsy

Percutaneous kidney biopsy is an integral part of a nephrologist's practice. It has helped to define nephrology as a subspecialty. When indicated, it is a necessary procedure to help patients, as it allows for diagnostic, prognostic, and therapeutic information. Although very safe, this procedure can give rise to complications, mainly related to bleeding. Since its development in the 1950s, modifications have been made to the approach and the technique, which have improved the diagnostic yield while keeping it a safe procedure. Alterations to the standard approach may be necessary if risk factors for bleeding are present. In addition, obesity, pregnancy, and solitary kidney biopsy are all special circumstances that change the procedure itself or the risk of the procedure. Today, kidney biopsy is a vital procedure for the nephrologist: clinically relevant, safe, and effective.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Abdominal pain in special populations

Evaluation and management of acute abdominal pain in special populations can be challenging for the emergency physician. This article focuses on two specific populations: patients with altered immunologic function and postprocedural patients. Recognition of life-threatening abdominal diseases may be delayed in immunosuppressed patients because of the atypical presentations of these conditions. In postprocedural patients, evaluation of acute abdominal symptoms requires an understanding of the complications of procedures often performed by others. The unique characteristics of abdominal pain in these two populations and, more specifically, which diseases to consider and how to use appropriate testing to detect life-threatening conditions, are discussed.

Complications of percutaneous procedures

Minimally invasive percutaneous procedures are increasingly being performed by both interventional radiologists and noninterventionalists. Patients with postprocedural issues will likely present to the emergency department for evaluation and treatment. This review focuses on the evaluation and management of the complications of common percutaneous procedures.

Renal biopsy practice in France: results of a nationwide study

BACKGROUND

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

METHODS

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

RESULTS

Eighty-eight nephrologists from 74 units (27 in teaching hospitals, 35 in public general hospitals and 12 in private centres) participated in our study. Native kidney and graft biopsies were performed in 73 and 35 units, respectively. RB activity was highly variable among units, ranging from several hundred to <10 per year. Transjugular renal biopsy was judged to be smoothly accessible in 28 out of 73 units (38.4%). Significant variations in practices were observed regarding patient information before RB, assessment of haemorrhagic risk factors, management of patients with antiplatelet agents and haemorrhagic risk factors, and radiological guidance. Early discharge (<12 h) was the rule in 3 (4.1%) units for native kidney biopsies and in 10 (28.6%) units for graft biopsies.

CONCLUSIONS

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

The renal biopsy

CONTEXT

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

OBJECTIVES

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

DATA SOURCES

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

CONCLUSIONS

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

Transjugular renal biopsy: our experience and technical considerations

The purpose of this study was to describe the indications for and technique of transjugular renal biopsy (TJRB) and evaluate the efficacy and complications of this method. We performed a retrospective review of 59 patients who underwent TJRB using the Quick-core needle biopsy system (Cook, Letchworth, UK) over a 4-year period. The indications for obtaining renal biopsy included acute renal failure, chronic renal failure, nephrotic syndrome, and proteinuria with or without other associated disease. Indications for the transjugular approach included coagulopathy, biopsy of a solitary kidney or essentially single functioning kidney, simultaneous renal and hepatic biopsy, morbid obesity, and failed percutaneous biopsy. All but four cases were performed via the right internal jugular vein. The right, left, or both renal veins were cannulated in 41, 14, and 4 cases, respectively. Combined liver and renal biopsies were obtained in seven cases. Diagnostic biopsy specimens were obtained in 56 of 59 patients (95%). The number and size of tissue cores ranged from 1 to 9 mm and from 1 to 20 mm, respectively. The mean numbers of glomeruli per procedure on light microscopy and electron microscopy were 10.3 and 2.6, respectively. Specimens for immunohistology were acquired in 49 cases, of which 40 were adequate. Of the 56 successful TJRB procedures, 34 (61%) were associated with isolated capsular perforation (19), contained subcapsular leak (10), isolated collecting system puncture (1), and concurrent collecting system and capsular perforation (4). There was a significant increase in capsular perforation with six or more needle passes, although no significant correlation was seen between number of needle passes and complication. Six patients had minor complications defined as hematuria or loin pain. Seven patients developed major complications, of whom five received blood transfusion alone. Two required intervention: in one an arteriocalyceal fistula was embolized and the patient was temporarily dialyzed; the remaining patient required ureteric stenting. In conclusion, TJRB provides an adequate yield for diagnosis. Complication rates are relatively high, but patients are also at high risk from the conventional percutaneous approach. Patient selection and optimization are critical to avoid major complications.

Endovascular and interventional procedures in obese patients: a review of procedural technique modifications and radiation management

As the prevalence of obesity in the United States continues to increase, the volume of endovascular and fluoroscopically guided procedures is also increasing. With obese patients, it often seems the only consideration is whether the table weight tolerance can accommodate the patient. This is a naive approach to performing procedures in obese patients, as there are multiple considerations involved in providing state-of-the-art endovascular and interventional care to obese patients. A growing collection of literature is beginning to surface regarding the appropriate modifications in the interventional care of these patients. This article reviews the relevant literature on this important subject.

The role of ultrasound in renal insufficiency: the essentials

Sonography is the best screening modality to evaluate patients presenting with renal insufficiency. Ultrasound findings can be normal in patients with renal disease, especially in prerenal azotemia and acute parenchymal renal disease. Echogenic kidneys indicate the presence of parenchymal renal disease; the kidneys may be of a normal size or enlarged. Small kidneys suggest advanced stage chronic kidney disease. Uncommonly, cystic disease of the kidney, especially adult type polycystic kidney disease may be the cause of the patient's renal insufficiency with bilaterally enlarged kidneys containing multiple cysts of various sizes. If hydronephrosis is present, the level and cause of the obstruction should be sought. When ultrasound cannot diagnose the level and cause of obstruction, other imaging modalities, including CT and MRI may be useful. When renovascular disease (arterial stenosis or venous thrombosis) is suspected, spectral and color Doppler can be useful in detecting abnormalities.

Renal biopsy: update

PURPOSE OF REVIEW

The renal biopsy is an invaluable tool in the diagnosis, prognosis, and management of patients with kidney disease. As the success of the procedure is defined not only by the ability to obtain adequate tissue but also by the safety profile, significant advances which define risk factors and determine the optimal timing of observation after the percutaneous native renal biopsy merit discussion. Alternative methods of obtaining tissue, such as transvenous renal biopsies, have also been described, especially in patients with contraindications to the percutaneous method.

RECENT FINDINGS

The percutaneous renal biopsy has been established as a safe and effective method of obtaining renal parenchyma. Complications, although rare, may occur and the majority of these are related to bleeding. The optimal timing of observation after the biopsy should be determined by when most complications occur, and, as over 33% of complications occur after 8 h, an observation period of at least 24 h is recommended. In patients with contraindications to the percutaneous approach, such as failure of adequate radiologic visualization or a bleeding diathesis, alternative methods of obtaining tissue have been attempted. These include open, laparascopic, transurethral, or transvenous renal biopsy.

SUMMARY

Without contraindications, the percutaneous renal biopsy remains the standard method of acquiring renal tissue. At least 24 h of observation is recommended after the percutaneous native kidney biopsy for the development of potential complications. When a contraindication to the procedure exists, other methods of renal biopsy by experienced physicians may be attempted.