Artifact reduction of coaxial needles in magnetic resonance imaging-guided abdominal interventions at 1.5 T: a phantom study.

Needle artifacts pose a major limitation for MRI-guided interventions, as they impact the visually perceived needle size and needle-to-target-distance. The objective of this agar liver phantom study was to establish an experimental basis to understand and reduce needle artifact formation during MRI-guided abdominal interventions. Using a vendor-specific prototype fluoroscopic T1-weighted gradient echo sequence with real-time multiplanar acquisition at 1.5 T, the influence of 6 parameters (flip angle, bandwidth, matrix, slice thickness, read-out direction, intervention angle relative to B0) on artifact formation of 4 different coaxial MR-compatible coaxial needles (Nitinol, 16G-22G) was investigated. As one parameter was modified, the others remained constant. For each individual parameter variation, 2 independent and blinded readers rated artifact diameters at 2 predefined positions (15 mm distance from the perceived needle tip and at 50% of the needle length). Differences between the experimental subgroups were assessed by Bonferroni-corrected non-parametric tests. Correlations between continuous variables were expressed by the Bravais-Pearson coefficient and interrater reliability was quantified using the intraclass classification coefficient. Needle artifact size increased gradually with increasing flip angles (p = 0.002) as well as increasing intervention angles (p < 0.001). Artifact diameters differed significantly between the chosen matrix sizes (p = 0.002) while modifying bandwidth, readout direction, and slice thickness showed no significant differences. Interrater reliability was high (intraclass correlation coefficient 0.776-0.910). To minimize needle artifacts in MRI-guided abdominal interventions while maintaining optimal visibility of the coaxial needle, we suggest medium-range flip angles and low intervention angles relative to B0.

Adequacy criteria of Tru-cut needle liver biopsy in neonatal cholestasis.

INTRODUCTION AND OBJECTIVES: Assessment of liver biopsy sample adequacy criteria is essential to avoid sampling errors in patients with diffuse liver pathology. Many studies have evaluated these criteria in adults; however, no previous studies have been performed on neonatal liver disorders. We aimed to assess the adequacy criteria of Tru-cut needle liver biopsy samples in infants with neonatal cholestasis (NC). METHODS: In a retrospective analysis of infants who underwent liver biopsy for NC within a one-year duration, 58 specimens were recruited. The core lengths after fixation were measured. All samples were acquired with a 16-gauge (G) Tru-cut needle. Serial shortening of these samples was performed to define the smallest core length that gives representative parenchyma that could determine the activity grade and fibrosis stage reported by larger cores. RESULTS: It was found that a 4-mm core length with a complete portal tract (CPT) number of 8±3 could adequately assess the NC activity grade. In addition, a 6-mm core length with a CPT number of 11±3 could adequately estimate NC fibrosis stage. CONCLUSIONS: The adequacy criteria of liver tissue samples for the accurate assessment of NC are different from those defined for adult diffuse liver pathology. At least a 4-mm core length with a CPT number of 8±3 and a 6-mm core length with a CPT number of 11±3 acquired by a 16-G Tru-cut needle should be used to assess NC activity grade and fibrosis stage, respectively.

A real-world study evaluating ultrasound-guided percutaneous non-targeted liver biopsy needle failures and pathology sample-quality assessment in both end-cut and side-notch needles.

OBJECTIVES: To determine biopsy device failures, causative factors, complications and sample quality of the 16G end-cut Biopince™ and side-notch Bard™ needles. METHODS: All ultrasound-guided non-targeted liver biopsies between 01/01/2016 and 31/12/2018 were included. Operator, device, number of failures, complications and repeat biopsies were recorded. Histopathology samples were reviewed for all cases of needle failure and a group with no failures, and graded "yes/no" for the presence of steatosis, inflammation and fibrosis. The pathology slides from these cases were reviewed to assess biopsy sample quality (length and portal tract number). The failure and no-failure groups were compared in terms of device type/histology, and sample quality was compared between the needle types. RESULTS: 1004 patients were included. 93.8% (n = 942) required one needle pass to obtain a sample and 6.2% (n = 62) required >1 pass due to needle failure. Total of 76 needle failures, more with end-cut than side-notch needles (8.7% vs 2.9%) (p < 0.001). No needle failures resulted in complication. The presence of liver fibrosis was associated with fewer needle failures (p = 0.036). The major complication rate was 0.4% (4/1044). A biopsy with >10 portal tracts was obtained in 90.2% of specimens > 20 mm long, compared with 66% of 16-20 mm biopsies and 21% of <16 mm biopsies. The target of >10 portal tracts was achieved in 10/26 (38.5%) of side-notch biopsies and 64/90 (71.1%) of end-cut biopsies (p = 0.004). CONCLUSION: Ultrasound-guided liver biopsy is safe and sample quality is consistently good when a core >20 mm long is obtained. The end-cut biopsy device generated reliably good quality biopsy samples; however, the needle failure rate was significantly higher than the side-cut needle. ADVANCES IN KNOWLEDGE: Ultrasound-guided liver biopsy specimen quality is consistently good when a core >20 mm long is obtained which can be achieved with a single pass using the 16G BiopinceTM end-cut needle, although the needle failure rate is significantly higher than the 16G Max-Core™ Bard™ side-notch needle.

Sectoral cancer detection and tolerability of freehand transperineal prostate biopsy under local anaesthesia.

BACKGROUND: To investigate the feasibility of a freehand transperineal (TP) systematic prostate biopsy protocol under local anaesthesia (LA) and the value of different sectors in diagnosing prostate cancer (PCa). METHODS: A total of 611 consecutive freehand TP biopsies under LA in 2 hospitals were prospectively evaluated. Cancer detection rate in each of the four different sectors (anterior, mid, posterior, basal) was recorded to evaluate the value of each sector. Procedure tolerability was assessed by pain score and complications were documented. RESULTS: Systematic biopsies were performed in 556 out of 611 men with a median of 20 (IQR 12-24) biopsy cores taken. The median PSA was 9.9 (Inter-quartile range[IQR] 6.4-16.2) ng/mL, and 89.0% were first biopsies. All PCa and ISUP grade group (GG) ≥ 2 PCa (HGPCa) were diagnosed in 41.4% (230/556) and 28.2% (157/556) biopsies respectively. 77.0% HGPCa was diagnosed in ≥2 sectors. Single-sector HGPCa was predominantly found in anterior or posterior sector. Omitting base sector would have missed 1.5% (1/65) HGPCa out of the 219 cases with ≥24-core biopsies performed. Further omission of mid sector would have missed 3.1% (2/65) HGPCa and 7.4% (7/94) ISUP GG1 PCa (in which 3/7 involved 2 sectors). LA TP biopsy was well tolerated and the mean pain scores of the different steps of the procedure were between 1.9-3.1 (out of 10). Post-biopsy fever occurred in 0.3% of patients (2/611) and no sepsis was reported. The risk of urinary retention in men with ≥20 cores in ≥60 ml prostate was 7.8% (14/179), compared with 1.7% (7/423) in other groups (p < 0.001). CONCLUSIONS: TP sectoral prostate biopsy under LA was well tolerated with minimal sepsis risk. Basal sector biopsies had minimal additional value to HGPCa detection and its omission can be considered.

Smart needle to diagnose metastatic lymph node using electrical impedance spectroscopy.

OBJECTIVES: The cause of cervical lymphadenopathy varies from inflammation to malignancy. Accurate and prompt diagnosis is crucial as delayed detection of malignant lymph node can lead to a worse prognosis. To improve the diagnostic accuracy of metastatic lymph node, electrical spectroscopy was employed to study human normal and metastatic lymph nodes using a hypodermic needle with fine interdigitated electrodes on its tip (EoN). SUBJECTS AND METHODS: The electrical impedance of samples collected from 8 patients were analyzed in the sweeping frequency range from 1 Hz to 1 MHz. To align the impedance level data of the patients, normalized impedance was employed. RESULTS: The optimal frequency exhibiting the best discrimination results between the normal and cancerous tissues was introduced based on a discrimination index. A high sensitivity (86.2%) and specificity (88.9%) were obtained, which implied that the EoN holds the potential to improve the in vivo diagnostic accuracy of metastatic lymph node during biopsy and surgery. CONCLUSION: EoN has a promising potential to be utilized in real-time in actual clinical trials without a need for any pre/post-treatment during FNA or surgery. We believe that the EoN could reduce unnecessary operations with its associated morbidity.

Usefulness of a novel device to divide core needle biopsy specimens in a spatially matched fashion.

We developed a novel dividing device that can split needle biopsy tissues along longitude axis aiming to achieve definitive molecular-biological and genetical analysis with reference of pathological diagnosis of the side-by-side divided tissue as spatially matched information. The aim of this study was to evaluate the feasibility and potential usefulness of the novel dividing device to provide the appropriate materials for molecular diagnosis. The new device was examined using mouse xenograft tumors. Real-time quantitative PCR and genetic test were performed to evaluate the feasibility and usefulness of the device. All the samples from needle biopsy were successfully divided into two pieces. Quality and quantity from divided samples harbor high enough to perform gene expression analysis (real-time PCR) and genetic test. Using two divided samples obtained from xenograft tumor model by needle biopsy, the % length of xenograft tumor (human origin) was significantly correlated with the % human genomic DNA (p = 0.00000608, r = 0.987), indicating that these divided samples were spatially matched. The novel longitudinally dividing device of a needle biopsy tissue was useful to provide the appropriate materials for molecular-biological and genetical analysis with reference of pathological diagnosis as spatially matched information.

Needle Tip Culture after Prostate Biopsy: A Tool for Early Detection for Antibiotics Selection in Cases of Post-Biopsy Infection.

PURPOSE: To investigate biopsy needle tip culture after prostate biopsies for bacteria prediction and antibiotics selection. MATERIALS AND METHODS: From May 2017 to April 2019, 121 patients who underwent a prostate biopsy were enrolled. All biopsy needle tips were sent for aerobic and anaerobic culture. Patients were divided into positive and negative culture groups. Perioperative data were recorded and compared between the two groups. The culture time and susceptibility of febrile patients were analyzed. Blood cultures were conducted for all patients who experienced fever after biopsy. The time and results of the needle and blood cultures were recoded for descriptive analysis. RESULTS: There were 59 (48.8%) positive needle cultures. Other than fever (p = 0.023), there were no statistical significances in clinical data between the two groups. Fever occurred in eight patients, and seven febrile patients had positive needle cultures, six of whom had positive blood cultures. These six needle and blood cultures were consistent with the susceptibility test results. As compared to the waiting time for blood cultures, target antibiotics were administered at an average of 48.0 h earlier based on needle cultures. None of the patients with positive anaerobic cultures developed a fever, while all eight febrile patients had negative anaerobic cultures. CONCLUSION: Fevers developed at statistically significant higher rate among those who had positive needle cultures. Needle and blood cultures were consistent with the susceptibility test results. Needle cultures can help us administer target antibiotics earlier to febrile patients without the need to wait for blood cultures.

Benign breast papillomas without atypia diagnosed with core needle biopsy: Outcome of surgical excision and imaging follow-up.

PURPOSE: To evaluate the surgical upgrade rate to malignancy and high-risk lesions in cases of papilloma without atypia diagnosed with imaging-guided percutaneous core needle biopsy (CNB) and to determine whether any lesion imaging features, biopsy techniques, and pathological factors can predict lesion upgrade to help guide clinical management. MATERIALS AND METHODS: Benign papillomas without atypia (n = 399) diagnosed with CNB were retrospectively reviewed. The surgical upgrade rate to malignancy or high-risk lesion (atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in-situ, flat epithelial atypia and atypical papilloma) was determined. Detection modality (i.e. mammography, ultrasonography (US), magnetic resonance imaging (MRI)), lesion type and size, biopsy-guidance modality (US, stereotactic, MRI), biopsy needle size (<14 G vs ≥14 G), use of vacuum assistance, and presenting symptoms were statistically analyzed. The reference standard for evaluation of upgrade was either excision or at least 24 months of imaging follow-up. Chi Square test and Fisher exact tests were performed for categorical variables, and the Mann-Whitney-U test was used for continuous variables. RESULTS: Ultrasound was the predominant biopsy modality (78.4 %, p < 0.001). Of the 399 benign papilloma lesions in 329 women, 239 (59.9 %) were excised and 93 others were followed for at least 24 months (total of 332). Of these 332 lesions, 7 (2.1 %) were upgraded to ductal carcinoma in-situ and 41 (12.3 %) to high-risk lesions at excision. Larger lesion size (≥15 mm, p = 0.009), smaller biopsy needle size (≥14 G, p = 0.027), and use of spring-loaded biopsy device (p = 0.012) were significantly associated with upgrade to atypia. Only lesion size (≥15 mm, p = 0.02) was associated with upgrade to cancer. CONCLUSION: Upgrade to malignancy of biopsy-proven benign papillomas without atypia at the time of surgery was sufficiently low (2.1 %) to support non-operative management. Surgery may be performed for selected cases- those with larger lesion size and those whose biopsies were performed with smaller spring-loaded biopsy needles.

Optical percutaneous needle biopsy of the liver: a pilot animal and clinical study.

This paper presents the results of the experiments which were performed using the optical biopsy system specially developed for in vivo tissue classification during the percutaneous needle biopsy (PNB) of the liver. The proposed system includes an optical probe of small diameter acceptable for use in the PNB of the liver. The results of the feasibility studies and actual tests on laboratory mice with inoculated hepatocellular carcinoma and in clinical conditions on patients with liver tumors are presented and discussed. Monte Carlo simulations were carried out to assess the diagnostic volume and to trace the sensing depth. Fluorescence and diffuse reflectance spectroscopy measurements were used to monitor metabolic and morphological changes in tissues. The tissue oxygen saturation was evaluated using a recently developed approach to neural network fitting of diffuse reflectance spectra. The Support Vector Machine Classification was applied to identify intact liver and tumor tissues. Analysis of the obtained results shows the high sensitivity and specificity of the proposed multimodal method. This approach allows to obtain information before the tissue sample is taken, which makes it possible to significantly reduce the number of false-negative biopsies.

Adequacy and complication rates of percutaneous renal biopsy with 18- vs. 16-gauge needles in native kidneys in Chinese individuals.

BACKGROUND: Percutaneous renal biopsy (PRB) is the primary biopsy technique and it was used by 16G needles or 18G needles in China, but there is controversy about the effect and safety of the two different diameters. The study aims to compare the adequacy, complication rate and pathological classification when using 18G vs. 16G needles to perform renal biopsy with ultrasound-guidedance on native kidneys in Chinese individuals. METHODS: We retrospectively analyzed the number of glomeruli, adequate sample rates, complication rates and pathological classification in 270 patients with the use of 18G or 16G needles from January 2011 to May 2017 and verified whether the needle gauge affected the disease diagnosis. RESULTS: A total of 270 kidney biopsies were performed. Among them,72 were performed with 18G needles, and 198 were performed with 16G needles. There was no difference in the number of glomeruli under light microscope using 18G relative to 16G needles (24 ± 11 vs. 25 ± 11, p = 0.265), whereas more glomeruli were found in the 16G group than in the 16G group using immunofluorescence microscopy (3 ± 2 vs. 5 ± 3, p < 0.05). There was no significant difference in the adequate sample rates between the 18G group and the 16G group (90.28% vs. 93.94%, p = 0.298). Minor complications including the incidence of lumbar or abdominal pain (4.17% vs. 7.07%, p = 0.57), gross hematuria (4.17% vs. 3.54%, p = 0.729), and perinephric hematoma without symptoms (4.17% vs. 1.52%, p = 0.195), were not significantly different between the 18G and 16G groups. In the 16G group, 2 cases of serious complications occurred: severe gross hematuria requiring blood transfusion and retroperitoneal hematoma requiring surgery. No serious complications were observed in the 18G group, although there was no significant difference in serious complications rates between the 18G and 16G groups (0% vs. 1.02%, p = 1). CONCLUSION: There was no significant difference in the number of glomeruli, adequate sample rates, or complication rates when using 18G or 16G needles to perform renal biopsy, and the use of an 18G needle with a smaller diameter did not affect the pathological diagnosis or classification of IgA nephropathy and lupus nephritis.

Integration and evaluation of a gradient-based needle navigation system for percutaneous MR-guided interventions.

The purpose of the present study was to integrate an interactive gradient-based needle navigation system and to evaluate the feasibility and accuracy of the system for real-time MR guided needle puncture in a multi-ring phantom and in vivo in a porcine model. The gradient-based navigation system was implemented in a 1.5T MRI. An interactive multi-slice real-time sequence was modified to provide the excitation gradients used by two sets of three orthogonal pick-up coils integrated into a needle holder. Position and orientation of the needle holder were determined and the trajectory was superimposed on pre-acquired MR images. A gel phantom with embedded ring targets was used to evaluate accuracy using 3D distance from needle tip to target. Six punctures were performed in animals to evaluate feasibility, time, overall error (target to needle tip) and system error (needle tip to the guidance needle trajectory) in vivo. In the phantom experiments, the overall error was 6.2±2.9 mm (mean±SD) and 4.4±1.3 mm, respectively. In the porcine model, the setup time ranged from 176 to 204 seconds, the average needle insertion time was 96.3±40.5 seconds (min: 42 seconds; max: 154 seconds). The overall error and the system error was 8.8±7.8 mm (min: 0.8 mm; max: 20.0 mm) and 3.3±1.4 mm (min: 1.8 mm; max: 5.2 mm), respectively.

Efficacy and safety of bone marrow aspiration and biopsy using fluoroscopic guidance and a drill-powered needle: clinical experience from 775 cases.

OBJECTIVES: To evaluate the efficacy and safety of performing a fluoroscopically guided bone marrow aspiration and biopsy (BMAB) using a drill-powered needle in a large patient population. METHODS: This retrospective study received institutional review board approval with a waiver of patient informed consent. We identified all BMAB procedures from August 2012 through December 2016 performed at our institution using fluoroscopic guidance and a drill-powered needle. Clinical diagnosis, patient age, patient gender, biopsy site, biopsy needle gauge, bone marrow aspirate volume, bone marrow core biopsy length, patient platelet count, conscious sedation details, complications, and diagnostic adequacy were investigated for each case and summarized. RESULTS: A total of 775 BMAB procedures were performed and analyzed. These were performed in 436 female patients and 339 male patients ranging in age between 16 and 91 years (average age of 53 years). Samples obtained from the procedures in our series were diagnostic in 95.0% of cases. The complication rate for our series was 0.3%. CONCLUSIONS: The use of fluoroscopic guidance and a drill-powered needle for bone marrow aspiration and biopsy is a safe and efficacious procedure. KEY POINTS: • Fluoroscopy can be utilized for imaging guidance during bone marrow aspiration and biopsy. • The use of fluoroscopic guidance and a drill-powered needle for bone marrow aspiration and biopsy has a high diagnostic yield. • The procedure has an excellent patient safety profile.

Difference in specimen weights with semi-automatic cutting biopsy needles.

PURPOSE: To assess specimen weight difference of six types of semi-automatic cutting biopsy needles. MATERIALS AND METHODS: We compared 18- and 20-gauge needles, one aspiration-type (STARCUT® aspiration-type, TSK Laboratory, Tochigi, Japan) and five non-aspiration-type (MISSION®, BARD, AZ; SuperCore™, Argon Medical Devices, TX; Temno Evolution®, Care Fusion, IL; FINE CORE®, Toray Medical, Tokyo, Japan; Quick-Core®, Cook, IN) needles. Four biopsies were performed with each needle with the longest throw length on an excised bovine liver. The biopsies were repeated with new needles, four times with four different livers. STARCUT® was used both with and without aspiration. RESULTS: Sixteen specimens were obtained with each needle. In needles of gauges, STARCUT® with aspiration provided the heaviest specimen and significantly heavier specimens were obtained with STARCUT® with aspiration (P < 0.05) than five non-aspiration-type needles. The specimen weight differed significantly (P < 0.001) among all 18- and 20-gauge needles. The specimen weights did not differ significantly between aspiration and non-aspiration biopsies with STARCUT® (6.32 vs. 5.97 mg with 18-gauge needle, P = 0.342; 1.95 vs. 1.92 mg with 20-gauge needle, P = 0.886). CONCLUSION: Although STARCUT® with aspiration provided the heaviest specimen, specimen weights were not significantly different between aspiration and non-aspiration biopsies. We assessed the specimen weight difference of six types of semi-automatic cutting biopsy needles. Significantly heavier specimens were obtained with STARCUT® with aspiration than the other needles. The specimen weight differed significantly among all 18- and 20-gauge needles but did not differ significantly between aspiration and non-aspiration biopsies with STARCUT®.

Added Value of Impact Microindentation in the Evaluation of Bone Fragility: A Systematic Review of the Literature.

The current gold standard for the diagnosis of osteoporosis and the prediction of fracture risk is the measurement of bone mineral density (BMD) using dual energy x-ray absorptiometry (DXA). A low BMD is clearly associated with increased fracture risk, but BMD is not the only determinant of bone strength, particularly in secondary osteoporosis and metabolic bone disorders in which components other than BMD are affected and DXA often underestimates true fracture risk. Material properties of bone which significantly contribute to bone strength have become evaluable in vivo with the impact microindentation (IMI) technique using the OsteoProbe® device. The question arises whether this new tool is of added value in the evaluation of bone fragility. To this effect, we conducted a systematic review of all clinical studies using IMI in vivo in humans also addressing practical aspects of the technique and differences in study design, which may impact outcome. Search data generated 38 studies showing that IMI can identify patients with primary osteoporosis and fractures, patients with secondary osteoporosis due to various underlying systemic disorders, and scarce longitudinal data also show that this tool can detect changes in bone material strength index (BMSi), following bone-modifying therapy including use of corticosteroids. However, this main outcome parameter was not always concordant between studies. This systematic review also identified a number of factors that impact on BMSi outcome. These include subject- and disease-related factors such as the relationship between BMSi and age, geographical region and the presence of fractures, and technique- and operator-related factors. Taken together, findings from this systematic review confirm the added value of IMI for the evaluation and follow-up of elements of bone fragility, particularly in secondary osteoporosis. Notwithstanding, the high variability of BMSi outcome between studies calls for age-dependent reference values, and for the harmonization of study protocols. Prospective multicenter trials using standard operating procedures are required to establish the value of IMI in the prediction of future fracture risk, before this technique is introduced in routine clinical practice.

Evaluation of risk factors in pneumothorax development after computerized tomography-guided transthoracic biopsy and management of complications.

AIMS: This study aims to discuss the relationship between complications and patient characteristics and lesion properties in the transthoracic fine needle aspiration biopsy (TTFNAB) procedures performed for lung lesions and the treatment applied in our clinic to eliminate these complications. METHODS: In this retrospective study conducted from July 2014 to August 2017, the CT-guided TTFNAB was performed on 186 patients (145 males, 41 females) who were considered to have malignancies on their clinical evaluation, CT, and PET CT results. RESULTS: After 186 CT-guided TTFNAB interventions, a total of 24 (12.9%) patients developed procedure-related pneumothorax. Of these patients, 7 had a limited and minimal pneumothorax and no treatment was required for them, while 17 had a large and increasing pneumothorax and manual air aspiration was performed with coaxial needle during the procedure. The number pleural transitions (OR 6.513; 95%, 2,529-16,771 P < 0.001), emphysematous lungs (OR 4.612; 95%, 1,852-11.487 P < 0.001), and the presence of a lesion unrelated to the pleura (OR 8.205; 95%, 3,162-21,291 P < 0.001) can form the basis for the development of a pneumothorax. CONCLUSION: The chances of developing pneumothorax after TTFNAB depend on number of pleural transition, emphysematous lungs, and non-pleural lesions. However, it is considered that procedures such as manual air aspiration and autologous blood patch may reduce the need for chest tube following the development of pneumothorax.

Intramarrow injection needle: a new technique to treat patients with haematological and non-haematological malignancies by directly injecting therapeutic agents into the bone marrow cavity.

AIMS: The purpose of this report is to describe a new instrument designed for the injection of therapeutic agents directly into the bone marrow cavity as well as to aspirate bone marrow specimens for the diagnostic purposes. METHODS: The instrument consists of three parts: the needle, stilette and an adjustable guard. The overall length of the needle is 76 mm and has uniform external diameter except for the distal penetrating segment, which is sharp but short and safe to use on the sternum. The proximal end of the needle is fitted with a plastic T-bar handle, which is ergonomically designed for firm grip and easy manoeuvrability. RESULTS: The instrument has been designed to obtain bone marrow aspirate specimens as well as to inject therapeutic agents into the posterior ilium. CONCLUSIONS: The rationale for the intramedullary injection of therapeutic agents for the treatment of patients with leukaemia, lymphoma and other haematological and non-haematological malignant disorders is described. In an emergency when intravenous therapy becomes difficult due to collapsed veins, this instrument may be used for direct intramarrow infusion of blood and blood products.

Percutaneous Renal Biopsy Using an 18-Gauge Automated Needle Is Not Optimal.

BACKGROUND: As percutaneous renal biopsies (PRBs) are increasingly performed by radiologists, an increase in the use of 18-gauge automated needle stands to compromise adequacy. We compare the adequacy and safety of PRB with 14-, 16-, and 18-gauge automated needles. METHODS: PRB of native (N-592) and transplant (T-1,023) kidneys was performed from January 2002 to December 2019 using real-time ultrasound. Baseline clinical and laboratory data, biopsy data (number of cores, total glomeruli, and total glomeruli per core), and outcome (hematoma on renal US at 1-h, complications, and transfusion) were collected prospectively. PRB with N14g (337) versus N16g (255) and T16g (892) versus T18g (131) needles were compared. A p value of <0.05 was significant. RESULTS: PRB with an 18-g needle yielded the lowest number of total glomeruli per biopsy (N14g vs. N16g: 33 ± 13 vs. 29 ± 12, p < 0.01 and T16g vs. T18g: 34 ± 16 vs. 21 ± 11, p < 0.0001), significantly fewer total glomeruli per core (T16g vs. T18g: 12.7 ± 6.4 vs. 9.6 ± 5.0, p < 0.001 and N16g vs. T18g: 14.2 ± 6.3 vs. 9.6 ± 5.0, p < 0.001). A hematoma by renal US 1-h post-PRB was similar for native (14g-35% vs. 16g-29%, p = 0.2), and transplant biopsies (16g-10% vs. 18g-9%, p = 0.9) and the complication rate for native (14g-8.9% vs. 16g-7.1%, p = 0.5), transplant biopsies (16g-4.6% vs. 18g-1.5%, p = 0.2) and transfusion rate for native (14g-7.7% vs. 16g-5.8%, p = 0.4), and transplant biopsies (16g-3.8% vs. 18g-0.8%, p = 0.1) were similar irrespective of needle size. CONCLUSIONS: PRB of native and transplant kidneys with the use of a 16-gauge needle provides an optimal sample. However, our experience in transplant biopsies suggests the use of an 18-gauge needle stands to jeopardize the diagnostic accuracy of the PRB while not improving safety.