Renal biopsy in high-risk patients with medical diseases of the kidney

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

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Urine biomarkers predict the cause of glomerular disease

Diagnosis of the type of glomerular disease that causes the nephrotic syndrome is necessary for appropriate treatment and typically requires a renal biopsy. The goal of this study was to identify candidate protein biomarkers to diagnose glomerular diseases. Proteomic methods and informatic analysis were used to identify patterns of urine proteins that are characteristic of the diseases. Urine proteins were separated by two-dimensional electrophoresis in 32 patients with FSGS, lupus nephritis, membranous nephropathy, or diabetic nephropathy. Protein abundances from 16 patients were used to train an artificial neural network to create a prediction algorithm. The remaining 16 patients were used as an external validation set to test the accuracy of the prediction algorithm. In the validation set, the model predicted the presence of the diseases with sensitivities between 75 and 86% and specificities from 92 to 67%. The probability of obtaining these results in the novel set by chance is 5 x 10(-8). Twenty-one gel spots were most important for the differentiation of the diseases. The spots were cut from the gel, and 20 were identified by mass spectrometry as charge forms of 11 plasma proteins: Orosomucoid, transferrin, alpha-1 microglobulin, zinc alpha-2 glycoprotein, alpha-1 antitrypsin, complement factor B, haptoglobin, transthyretin, plasma retinol binding protein, albumin, and hemopexin. These data show that diseases that cause nephrotic syndrome change glomerular protein permeability in characteristic patterns. The fingerprint of urine protein charge forms identifies the glomerular disease. The identified proteins are candidate biomarkers that can be tested in assays that are more amenable to clinical testing.

Safety of kidney biopsy in elderly: a prospective study

Kidney biopsy plays an important role in the diagnosis and management of several renal diseases. There is a general reluctance to perform kidney biopsy in elderly due to fear of complications. There is no prospective head to head trial comparing complications of percutaneous kidney biopsy in elderly versus young. This prospective study was undertaken to know the frequency and type of biopsy related complications in elderly. Biopsy was performed using a spring loaded automatic 16 G biopsy gun. Post-biopsy, patients were confined to bed rest for 24 h. A record of intraprocedural problems and post-procedural complications was kept. A total of 210 native kidney biopsies were done of which 26 were performed in elderly patients (61-78 years). Co-morbid conditions were present in 17 patients, some having more than one, hypertension (11), diabetes mellitus (5), chronic obstructive airway disease (6), interstitial lung disease (2) and coronary artery disease (2). Mean serum creatinine was 5.6 mg/dl (range 0.8-14.1 mg/dl). Pre-biopsy dialysis was given to 10 patients. Adequate tissue for histopathological diagnosis was seen in 24 out of 26 biopsies. In two elderly patients biopsy had to be abandoned though indicated due to inability to hold the breath because of underlying lung and cardiac disease. Clinico-pathologic discorrelation was seen in eight patients. Incidence of gross hematuria was more in elderly than in young (4/26 vs. 7/184 P<0.01). Hematuria subsided within 1-2 days in three, one had persistent hematuria for 1 week. Other complications viz. gross hematuria with need of blood transfusions or hemodynamic compromise (0/26 vs. 4/184), perinephric hematoma (0/26 vs. 1/184) and need of intervention (0/26 vs. 1/184) were not higher in the elderly. We conclude that the standard precautions kidney biopsy in elderly is a safe procedure.

Novel virtual biopsy of the kidney with near infrared, reflectance confocal microscopy: a pilot study in vivo and ex vivo

PURPOSE

Current diagnostic strategies for the kidney combine noninvasive imaging techniques with invasive procedures such as needle biopsy. However, renal needle biopsy is not devoid of risks, such as bleeding or infection. Additionally, histology studies are limited to ex vivo morphology and processing induces tissue artifacts, is time-consuming and limits the performance of further studies. Near infrared, reflectance CM is a novel technique that allows high resolution optical sectioning through intact tissues without using any exogenous fluorescent stains. Contrast between structures is based on the natural differences in refractivity. In this pilot study we assessed the usefulness of CM in the study of the kidney in vivo and ex vivo.

MATERIALS AND METHODS

Kidneys of live rats were imaged with CM. Contrast in images is based on native properties of the tissue upon being shone with a near infrared laser. By convention hyperrefractile structures are seen as white and hyporefractile structures are seen as black. CM imaging planes varied along the x, y and z axes of space. Images of live kidney were compared with those from ex vivo CM imaging and standard histology procedures.

RESULTS

The tubules, glomeruli, vessels and interstitium were readily identified, revealing intracellular detail. Differences between the kidney in vivo and ex vivo were also observed. Experimental contrast agents further highlighted the nuclei.

CONCLUSIONS

CM is a useful noninvasive imaging technique that is an adjunct to current techniques for 3-dimensional study of the kidney in vivo and ex vivo. Future technical developments will provide key applications during surgical intervention, transplantation and rapid tissue assessment.

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.

Predictors of bleeding complications in percutaneous ultrasound-guided renal biopsy

BACKGROUND

The risks associated with performing a percutaneous renal biopsy have substantially decreased in the past two decades because of technical advances in the method. However, bleeding complications still occur, resulting in increased hospital stay and treatment costs.

METHODS

We investigated the predictive value of demographics (age, gender), clinical data (blood pressure), baseline chemistry (hemoglobin/hematocrit, prothrombin time, partial thromboplastin time, bleeding time, serum creatinine, daily proteinuria), and needle size for the risk of major (need for blood transfusion, nephrectomy, or angiography) or minor (no need for any intervention) postrenal biopsy bleeding complications. This was a prospective cohort study of 471 patients who underwent ultrasound-guided biopsy of native kidney by automated needle in a single center; all biopsies were performed by two experienced nephrologists. Patients with transplant kidneys were excluded from the study. Predictors of postbiopsy bleeding were assessed by multiple linear and multivariate logistic regression analysis. Data are presented as unadjusted (OR) and adjusted odds ratios (AOR) with 95% confidence intervals (CI).

RESULTS

The study cohort consisted of 471 (277 males, 194 females) patients. Of these, 161 (34.1%) experienced postbiopsy bleeding [157 (33.3%) hematomas, 2 (0.4%) gross hematuria, 2 (0.4%) arteriovenous fistula]. Major complications were seen in 6 (1.2%) patients (blood transfusion, N= 2; angiography, N= 3; nephrectomy, N= 1), but no deaths occurred. The risk of postbiopsy bleeding was higher in women (39.7% women, 30.3% men, AOR 2.05, 95% CI 1.26 to 3.31, P= 0.004), younger subjects (35.0 +/- 14.5 years vs. 40.3 + 15.4, AOR 0.80, CI 0.68 to 0.94, P= 0.006), and patients with higher baseline partial thromboplastin time (102.7 + 11.8% vs. 100.1 + 10.0%, AOR 1.26, CI 1.02 to 1.54, P= 0.032). These findings were independent of size of hematoma.

CONCLUSION

Although the methods for performing a percutaneous renal biopsy have improved in the past two decades, renal biopsy is still not a risk-free procedure. Of the data routinely collected for potential predictors of postbiopsy bleeding complications, only gender, age, and baseline partial thromboplastin time show a significant predictive value. The other variables investigated do not have any predictive value.

Transjugular kidney biopsy

BACKGROUND

Most previous studies demonstrating the feasibility of transjugular kidney biopsy have used a modified Colapinto aspiration biopsy needle. We present 25 high-risk patients, with contraindications to percutaneous renal biopsy, who underwent transjugular kidney biopsy using a transvenous side-cut needle. This technique is easier to learn and can be performed by an interventional radiologist with transjugular liver biopsy experience and equipment. The needle is designed for optimal cortical sampling but has a high incidence of capsular perforation. Elective coil embolization was used in selected patients to reduce the risk of bleeding.

METHODS

We retrospectively reviewed the indications for obtaining renal histology, based on clinical presentation, and the specific indications for transjugular biopsy. Transjugular kidney biopsy was assessed for sampling effectiveness and adequacy, the impact of histology on patient management, and technique complication rates.

RESULTS

Renal tissue was obtained in 23 cases, with diagnostic biopsies in 21 of 23 (91.3%). A mean of 3.5 cores were obtained with 9.9 glomeruli per procedure for light microscopy (range, 0 to 32), 2.2 (range, 1 to 7) for electron microscopy, and adequate tissue for immunoflorescence available in 11 of 23 biopsies. Histology influenced patient management in all 23 cases. Capsular perforation was recorded in 73.9% (17 of 23) of cases with 6 undergoing elective coil embolization. Two major complications occurred, both in patients with multiple risk factors for bleeding. One required coil embolization of an arterio-calyseal system fistula. A further patient developed renal vein thrombosis 6 days after a failed transjugular kidney biopsy.

CONCLUSION

Transjugular kidney biopsy provides a histological diagnosis in high-risk patients, making an important contribution to patient management.

Percutaneous renal biopsy of native kidneys: a single-center experience of 1,055 biopsies

BACKGROUND

Percutaneous renal biopsy (PRB) of native kidneys is an essential tool in the diagnosis and management of renal disease. We report one of the largest single-center experiences on the success and safety of the procedure.

METHODS

From June 1983 to March 2012, 1,055 adults underwent PRB using real-time ultrasound guidance and 14-gauge biopsy needles. Data were collected prospectively for 826 biopsies (78%). Statistical analysis was performed using the Mann-Whitney test, Wilcoxon matched pairs test and Kruskal-Wallis test for continuous data or the Fisher's exact test and χ(2) test for categorical data. Multivariate analysis using logistic regression was performed to determine which feature at baseline was predictive of a complication following renal biopsy.

RESULTS

Patients were aged 46 ± 17 years; 38% were male, 40% were white and 43% were African-American. Serum creatinine (SCr) was 2.3 ± 2.3 mg/dl (>1.5 mg/dl in 47%). The pre-PRB hemoglobin was 12 ± 2 g/dl (<11.0 g/dl in 35%). Adequate tissue for diagnosis was obtained in 99% of biopsies. Minor complications occurred in 8.1% of biopsies (mainly gross hematuria, in 4.5%). Major complications occurred in 6.6% of biopsies, with transfusions required in 5.3%. Only 1 death (0.09%) resulted from post-PRB bleeding. By multivariate analysis, baseline features predictive of a complication were systolic blood pressure >170 mm Hg (OR 4.2, 95% CI 1.8-9.8), bleeding time >7.5 min (OR 1.7, CI 1.2-2.5) and SCr >3.5 mg/dl (OR 1.8, CI 1.2-2.9).

CONCLUSIONS

PRB of native kidneys using real-time ultrasound with a 14-gauge automated needle remains a successful and safe procedure.

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

BACKGROUND

The obese patient may be potentially at high risk for traditional percutaneous ultrasound-guided biopsy. The utility of transjugular kidney biopsy (TJKB) in this group of patients has not been established.

METHODS

We conducted a retrospective analysis of 37 obese patients who underwent TJKB at our centre. The kidney was approached via the right renal vein in 31 patients. Under fluoroscopy, core biopsies were obtained from the lower pole with a 19G biopsy needle. Post-procedure venogram was performed to assess for contrast extravasation indicating capsule perforation or communication with the collecting system. Patients were followed for procedure-related complications. Mean weight was 128 kg (range: 77-187 kg) and body mass index was 44 kg/m(2) (range: 34-64 kg/m(2)). Mean creatinine was 2.2 mg/dl (range: 0.5-6.5 mg/dl). Fifteen patients had diabetes, five of whom were nephrotic; 10 other patients had nephrotic range proteinuria.

RESULTS

Of the 37 patients, six were hospitalized at the time of biopsy and three were admitted for observation. All patients returned to baseline activity the day following procedure. Histopathological diagnosis was made in 33 cases (89.2%) with a mean of 19.2 glomeruli (range: 0-62 glomeruli) per patient. There was one major complication: a delayed retroperitoneal bleed requiring multiple transfusions. Contrast extravasation outside the capsule occurred in five patients and extravasation into the collecting system occurred in three. Body mass index was not associated with number of glomeruli obtained or complication rate.

CONCLUSIONS

TJKB in obese patients is a relatively safe, reliable and minimally invasive procedure with an excellent diagnostic yield.

Exploring the pathways leading from disadvantage to end-stage renal disease for Indigenous Australians

Indigenous Australians are disadvantaged, relative to other Australians, over a range of socio-economic and health measures. The age- and sex-adjusted incidence of end-stage renal disease (ESRD)--the irreversible preterminal phase of chronic renal failure--is almost nine times higher amongst Indigenous than it is amongst non-indigenous Australians. A striking gradient exists from urban to remote regions, where the standardised ESRD incidence is from 20 to more than 30 times the national incidence. We discuss the profound impact of renal disease on Indigenous Australians and their communities. We explore the linkages between disadvantage, often accompanied by geographic isolation, and both the initiation of renal disease, and its progression to ESRD. Purported explanations for the excess burden of renal disease in indigenous populations can be categorised as: primary renal disease explanations;genetic explanations;early development explanations; and socio-economic explanations. We discuss the strengths and weaknesses of these explanations and suggest a new hypothesis which integrates the existing evidence. We use this hypothesis to illuminate the pathways between disadvantage and the human biological processes which culminate in ESRD, and to propose prevention strategies across the life-course of Indigenous Australians to reduce their ESRD risk. Our hypothesis is likely to be relevant to an understanding of patterns of renal disease in other high-risk populations, particularly indigenous people in the developed world and people in developing countries. Furthermore, analogous pathways might be relevant to other chronic diseases, such as diabetes and cardiovascular disease. If we are able to confirm the various pathways from disadvantage to human biology, we will be better placed to advocate evidence-based interventions, both within and beyond the scope of the health-care system, to address the excess burden of renal and other chronic diseases among affected populations.

Laparoscopic renal biopsy: a 9-year experience

OBJECTIVES

To present our experience and outcome of consecutive laparoscopic renal biopsy over a 9-year period, as renal biopsy remains an important diagnostic procedure for evaluating proteinuria, haematuria and renal failure, but when percutaneous biopsy is contraindicated, a laparoscopic biopsy is an attractive option because it is minimally invasive.

PATIENTS AND METHODS

Seventy-four patients (29 male, 45 female, mean age 45 years, range 3-79) had a laparoscopic renal biopsy taken for various indications, e.g. morbid obesity, solitary kidney, coagulopathy, failed percutaneous biopsy, high location of the kidney and poor visualization with ultrasonography. The kidney was approached via a laparoscopic retroperitoneal route using a two-port technique, with the patient in the flank position. After identifying the kidney, one to five cortical biopsies were obtained with cup-biopsy forceps.

RESULTS

Adequate tissue was obtained in 96% of the patients; the mean (range) operative duration was 123 (9-261) min and the estimated blood loss 67 (5-2000) mL. Forty-three patients were discharged within 24 h. Complications occurred in 10 patients, with significant bleeding in three. One patient died after surgery, secondary to a perforated peptic ulcer while on high-dose steroid therapy.

CONCLUSION

Laparoscopic renal biopsy is a safe and effective alternative to open renal biopsy for patients in whom percutaneous biopsy is not feasible. It offers the advantage of obtaining cortical biopsies and achieving haemostasis under direct vision. Adequate renal tissue is obtained in most cases. Recovery and convalescence are short for most patients.

Transjugular renal biopsy in high-risk patients: an American case series

BACKGROUND

In the United States, transjugular renal biopsies using the Quickcore side cut needle system have previously been described primarily for transjugular renal biopsy in patients with concurrent liver and kidney disease.

METHODS

We describe transjugular renal biopsy with the Quickcore trade mark system in 9 patients with nephrotic syndrome and contraindications to percutaneous renal biopsy, who underwent biopsy between 23 October 1996 and 12 April 2001. The most common contraindication was oral anticoagulation with coumadin (40%). Other contraindications included horseshoe kidney, severe renal failure, and spontaneous coagulopathy. A 62 cm straight catheter and 60 cm side-cut Quickcore biopsy needle were used to obtain cortical tissue. Packing of the biopsy tract with Gelfoam was used for venographically identified capsular perforation.

RESULTS

Ten procedures were performed on 9 patients with one requiring re-biopsy (5% of all renal biopsies performed at our institution). There were 9 transjugular renal biopsy and one combined liver-kidney biopsy. A mean of 4 +/- 2 passes were made, with a mean of 3 +/- 1 cores obtained per procedure. Histologic diagnosis was made in 90% of biopsies and in 100% of patients. Two patients developed transient hydronephrosis associated with gross hematuria; both required transfusion. Capsular perforation occurred in 90%. One patient died of bacterial sepsis, unrelated to the biopsy, several days after the procedure.

CONCLUSIONS

Transjugular renal biopsy appears to be efficacious in high-risk patients, for whom the percutaneous approach is contraindicated, including patients on oral anticoagulation. The transfusion rate in the present study was similar to other American reports using this technique.

Percutaneous renal biopsy

Percutaneous renal biopsy (PRB) is an integral part of the clinical practice of nephrology. It is essential in the diagnosis of glomerular, vascular, and tubulointerstitial diseases of the kidney, providing information that is invaluable in prognosis and patient management. The use of real-time ultrasound and automated biopsy needles has simplified and improved the success and safety of this procedure. In the recent past, we have seen a shift of the PRB from nephrologists to radiologists and this has raised appropriate concern that loss of this procedure may undermine the nephrologist's status as a subspecialist. We must continue to properly train young nephrologists in the proper technique and value of performing renal biopsy procedures or we stand to lose control of a procedure that was an integral part of the development of our subspecialty.

Shunt nephritis from Propionibacterium acnes in a solitary kidney

Since its initial description in 1965, immune complex glomerulonephritis associated with ventriculoatrial shunts (VAS) has been reported widely in the literature. The most common incriminating organism is Staphylococcus epidermidis, but less often, an organism generally regarded as nonpathogenic, such as Propionibacterium acnes, has been noted as the cause. Shunt infection usually occurs within a few months after placement or manipulation of the shunt, and shunt nephritis (SN) develops gradually over months to years after. Treatment involves mandatory removal of the shunt and antibiotics; prognosis is variable. We report a case of SN with P acnes that is unusual because of its occurrence in a solitary kidney 6 years after shunt placement, persistently negative blood cultures, and normal complement levels. Percutaneous biopsy of a solitary kidney should be considered if it is expected that the result may guide therapy of progressive renal failure.

Discontinuation of the Bleeding Time Test without Detectable Adverse Clinical Impact

Background: The bleeding time (BT) test predicts a higher bleeding complication rate in populations at risk for inherited or acquired platelet dysfunction, but it is of limited assistance in evaluating individual patients. There are no reports of clinical outcomes after discontinuation of the BT test.

Methods: Interviews with a subset of the physicians who had ordered the BT test before discontinuation of the test were conducted. The total number of platelet-aggregation tests, the mean number of monthly, unmodified platelet units transfused, the incidence of kidney biopsy complications, and the number of doses of 1-deamino-8-d-arginine vasopressin (DDAVP) administered 5 months before and after discontinuation of the BT test were compared. We recorded the rates of bleeding complications in the Major Surgery Risk Pool during the 12 months before and the 5 months after the discontinuation of the BT test.

Results: Clinicians reported they did not significantly change their preprocedural work-ups, postpone an invasive procedure, experience an increase in bleeding complications, or increase their use of blood products after discontinuation of the BT test. Platelet-aggregation tests (n = 9, before and after), platelet transfusions (P = 0.958), and DDAVP administration (before = 24; after = 10) did not increase after discontinuation of the BT test. The rate of postprocedural bleeding complications did not increase significantly in either Major Surgery Risk Pool cases (&lt;3ς deviation from the mean rate) or in patients undergoing renal biopsies (P = 0.225 for decrease in hematocrit; P = 1.000 for the percentage of patients transfused) after discontinuation of the BT test.

Conclusions: Our study failed to identify a clinically significant, negative impact of discontinuing the BT test.