Major complications after ultrasound-guided liver biopsy:An annual audit of a Chinese tertiary-care teaching hospital

BACKGROUND As ultrasound-guided percutaneous liver biopsy(PLB)has become a standard and important method in the management of liver disease in our country,a periodical audit of the major complications is needed.AIM To determine the annual incidence of major complications following ultrasoundguided PLB and to identify variables that are significantly associated with an increased risk of major complications.METHODS A total of 1857 consecutive cases of PLB were included in our hospital from January 2021 to December 2021.The major complication rate and all-cause 30-d mortality rate were determined.Multivariate analyses were performed by logistic regression to investigate the risk factors associated with major complications and all-cause 30-d mortality following ultrasound-guided PLB.RESULTS In this audit of 1857 liver biopsies,10 cases(0.53%)of major complications occurred following ultrasound-guided PLB.The overall all-cause mortality rate at 30 d after PLB was 0.27%(5 cases).Two cases(0.11%)were attributed to major hemorrhage within 7 d after liver biopsy.Fibrinogen less than 2 g/L[odds ratio(OR):17.226;95%confidence interval(CI):2.647-112.102;P=0.003],post-biopsy hemoglobin level(OR:0.963;95%CI:0.942-0.985;P=0.001),obstructive jaundice(OR:6.698;95%CI:1.133-39.596;P=0.036),application of anticoagulants/antiplatelet medications(OR:24.078;95%CI:1.678-345.495;P=0.019)and age(OR:1.096;95%CI:1.012-1.187;P=0.025)were statistically associated with the incidence of major complications after PLB.CONCLUSION In conclusion,the results of this annual audit confirmed that ultrasound-guided PLB can be performed safely,with a major complication rate within the accepted range.Strict patient selection and peri-biopsy laboratory assessment are more important than procedural factors for optimizing the safety outcomes of this procedure.

Hemobilia and other complications caused by percutaneous ultrasound-guided liver biopsy

Hemobilia accounts for approximately 3%of all major percutaneous liver biopsy complications,and rarely results from arterioportal fistula.We report a patient who suffered from four complications over 11 d after ultrasound-guided percutaneous liver biopsy:hemobilia,acute pancreatitis,acute cholecystitis,and multiple stomach ulcers.Digital subtraction angiography was done after consultation with doctors,and showed obvious arteriovenous fistula of the right liver.The hepatic artery was selected and embolized by spring orbs.The active bleeding was stopped after embolization of the hepatic artery.The patient was discharged home on day 12 after embolization and remained well.

Update on endoscopic ultrasound-guided liver biopsy

Endoscopic ultrasound guided liver biopsy(EUS-LB)has emerged as a minimally-invasive alternative to the traditional(percutaneous or transjugular)liver biopsy techniques for the diagnosis of liver parenchymal diseases.Potentially,EUS-LB combines the advantages of percutaneous and transjugular liver biopsy in addressing focused sampling in addition to measuring portal pressure.Additionally,EUS-LB facilitates access to both the lobes of the liver which is not considered with the traditional percutaneous liver biopsy.Multiple studies have compared EUS-LB with conventional liver biopsy and reported comparable diagnostic yield,increased acquisition of complete portal tracts,and longer specimen length as compared to the traditional approaches.EUS-LB is associated with lesser post-procedural pain and shorter recovery time,while providing lower risk of complications when compared to traditional liver biopsy.Innovations in needle types,needle sizes and suction techniques have aimed at further optimizing the EUS-LB technique.This review article updates current literature with focus on the variations in the technique and equipment used for EUS-LB,and compares EUS-LB with traditional methods of liver biopsy.

Endoscopic ultrasound-guided tissue acquisition for the diagnosis of focal liver lesion

In patients with liver tumors,the histopathology examination can assist in diagnosis,staging,prognosis,and therapeutic management strategy.Endoscopic ultrasound(EUS)-guided tissue acquisition using fine needle aspiration(FNA)or more newly fine needle biopsy(FNB)is a well-developed technique in order to evaluate and differentiate the liver masses.The goal of the EUS-FNA or EUS-FNB is to provide an accurate sample for a histopathology examination.Therefore,malignant tumors such as hepatocarcinoma,cholangiocarcinoma and liver metastasis or benign tumors such as liver adenoma,focal hyperplastic nodular tumors and cystic lesions can be accurately diagnosed using EUS-guided tissue acquisition.EUS-FNB using 19 or 22 Ga needle provide longer samples and a higher diagnostic accuracy in patients with liver masses when compared with EUS-FNA.Few data are available on the diagnostic accuracy of EUS-FNB when compared with percutaneously,ultrasound,computer tomography or transjugulary-guided liver biopsies.This review will discuss the EUS-guided tissue acquisition options in patients with liver tumors and its efficacy and safety in providing accurate samples.The results of the last studies comparing EUS-guided liver biopsy with other conventional techniques are presented.The EUS-guided tissue acquisition using FNB can be a suitable technique in suspected liver lesions in order to provide an accurate histopathology diagnosis,especially for those who require endoscopy.

Endo-hepatology: Why should we do endoscopic ultrasound-guided interventions to the liver that we could do through the skin?

Endoscopic ultrasound(EUS)-guided interventions on the liver such as diffuse biopsy and portal pressure gradient measurement are emerging as potential alternatives to percutaneous procedures.The purpose of this editorial was to address all the indications that could potentially make an EUS-guided approach a possible alternative to the percutaneous procedures with respect to the proce-dures that could join the EUS examination such as upper endoscopy for gastro-esophageal varices,pancreaticobiliary investigation with EUS,and other potential advantages in terms of patient safety.The issue of a holistic gastroenterologist approach was also discussed along with the potential for developing clinical research.

Percutaneous ultrasound-guided coaxial core needle biopsy for the diagnosis of multiple splenic lesions: A case report

BACKGROUND The overlap of imaging manifestations among distinct splenic lesions gives rise to a diagnostic dilemma.Consequently,a definitive diagnosis primarily relies on his-tological results.The ultrasound(US)-guided coaxial core needle biopsy(CNB)not only procures sufficient tissue to help clarify the diagnosis,but reduces the incidence of puncture-related complications.CASE SUMMARY A 41-year-old female,with a history of pulmonary tuberculosis,was admitted to our hospital with multiple indeterminate splenic lesions.Gray-scale ultrasono-graphy demonstrated splenomegaly with numerous well-defined hypoechoic ma-sses.Abdominal contrast-enhanced computed tomography(CT)showed an en-larged spleen with multiple irregular-shaped,peripherally enhancing,hypodense lesions.Positron emission CT revealed numerous abnormal hyperglycemia foci.These imaging findings strongly indicated the possibility of infectious disease as the primary concern,with neoplastic lesions requiring exclusion.To obtain the precise pathological diagnosis,the US-guided coaxial CNB of the spleen was ca-rried out.The patient did not express any discomfort during the procedure.CONCLUSION Percutaneous US-guided coaxial CNB is an excellent and safe option for obtaining precise splenic tissue samples,as it significantly enhances sample yield for exact pathological analysis with minimum trauma to the spleen parenchyma and sur-rounding tissue.

Comparison of Cognitive Registration Transrectal Ultrasound-Guided Targeted Biopsy of Prostate to Systematic 12-Core Biopsy: A Retrospective, Multicentre Study

Introduction: Prostate cancer (PCa) is the third most prevalent cancer among Malaysian males, often diagnosed at advanced stages, leading to suboptimal outcomes. While transrectal ultrasound-guided systematic biopsy (TRUS-SB) is the primary diagnostic method, prebiopsy multiparametric magnetic resonance imaging (mpMRI) is gaining popularity in identifying suspicious lesions. This study addresses the lack of comprehensive investigations into the efficacy of cognitive registration TRUS targeted biopsy (COG-TB) compared to conventional TRUS-SB, considering the resource limitations of the Malaysian healthcare system. Materials and Methods: A retrospective cohort study was conducted in two Malaysian healthcare facilities. 116 adult patients with a prostate-specific antigen (PSA) level of more than 4 ng/mL who underwent both COG-TB and TRUS-SB between October 2020 and March 2022 were included. Primary outcomes were cancer detection rate and histopathological outcomes, including Gleason score. Results: COG-TB showed a higher overall cancer detection rate (50%) compared to TRUS-SB (44%). Clinically significant cancer detection rates were similar between COG-TB and TRUS-SB (37.1%). Further analysis revealed that both COG-TB and TRUS-SB detected clinically significant cancer in 30.2% of patients, did not detect it in 56.0%, and had conflicting findings in 16 patients (p Conclusion: COG-TB and TRUS-SB have comparable detection rates for clinically significant prostate cancer, with COG-TB showing a higher tendency to detect insignificant prostate cancer. Further studies comparing these methods are warranted.

Liver biopsy in the post-hepatitis C virus era in Japan

In Japan,liver biopsies were previously crucial in evaluating the severity of hepatitis caused by the hepatitis C virus(HCV)and diagnosing HCV-related hepatocellular carcinoma(HCC).However,due to the development of effective antiviral treatments and advanced imaging,the necessity for biopsies has significantly decreased.This change has resulted in fewer chances for diagnosing liver disease,causing many general pathologists to feel less confident in making liver biopsy diagnoses.This article provides a comprehensive overview of the challenges and potential solutions related to liver biopsies in Japan.First,it highlights the importance of considering steatotic liver diseases as independent conditions that can coexist with other liver diseases due to their increasing prevalence.Second,it emphasizes the need to avoid hasty assumptions of HCC in nodular lesions,because clinically diagnosable HCCs are not targets for biopsy.Third,the importance of diagnosing hepatic immune-related adverse events caused by immune checkpoint inhibitors is increasing due to the anticipated widespread use of these drugs.In conclusion,pathologists should be attuned to the changing landscape of liver diseases and approach liver biopsies with care and attention to detail.

Endoscopic ultrasound-guided biliary drainage vs percutaneous transhepatic bile duct drainage in the management of malignant obstructive jaundice

BACKGROUND Malignant obstructive jaundice(MOJ)is a condition characterized by varying degrees of bile duct stenosis and obstruction,accompanied by the progressive development of malignant tumors,leading to high morbidity and mortality rates.Currently,the two most commonly employed methods for its management are percutaneous transhepatic bile duct drainage(PTBD)and endoscopic ultrasound-guided biliary drainage(EUS-BD).While both methods have demonstrated favorable outcomes,additional research needs to be performed to determine their relative efficacy.To compare the therapeutic effectiveness of EUS-BD and PTBD in treating MOJ.METHODS This retrospective analysis,conducted between September 2015 and April 2023 at The Third Affiliated Hospital of Soochow University(The First People’s Hospital of Changzhou),involved 68 patients with MOJ.The patients were divided into two groups on the basis of surgical procedure received:EUS-BD subgroup(n=33)and PTBD subgroup(n=35).Variables such as general data,preoperative and postoperative indices,blood routine,liver function indices,myocardial function indices,operative success rate,clinical effectiveness,and complication rate were analyzed and compared between the subgroups.RESULTS In the EUS-BD subgroup,hospital stay duration,bile drainage volume,effective catheter time,and clinical effect-iveness rate were superior to those in the PTBD subgroup,although the differences were not statistically significant(P>0.05).The puncture time for the EUS-BD subgroup was shorter than that for the PTBD subgroup(P<0.05).Postoperative blood routine,liver function index,and myocardial function index in the EUS-BD subgroup were significantly lower than those in the PTBD subgroup(P<0.05).Additionally,the complication rate in the EUS-BD subgroup was lower than in the PTBD subgroup(P<0.05).CONCLUSION EUS-BD may reduce the number of punctures,improve liver and myocardial functions,alleviate traumatic stress,and decrease complication rates in MOJ treatment.

The efficacy and safety of endoscopic ultrasound-guided fine-needle biopsy in gallbladder masses

Background: Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB) is a widely used modality for acquiring various target samples, but its efficacy in gallbladder masses is unknown. The aim of this retrospective study was to evaluate the efficacy and safety of EUS-FNB in patients with gallbladder masses. Methods: The study samples were composed of patients from March 2015 to July 2019 who needed to identify the nature of gallbladder masses through EUS-FNB. The outcomes of this study were the adequacy of specimens, diagnostic yields, technical feasibility, and adverse events of the EUS-FNB in gallbladder masses. Results: A total of 27 consecutive patients with a median age of 58 years were included in this study. The 22-gauge FNB needle was feasible in all lesions. The median follow-up period of the patients was 294 days. The specimens sufficient for diagnosis account for 89%(24/27) and 93%(25/27) in cytology and histology, respectively. The overall diagnostic yields for malignancy showed the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 95.45% [95% confidence interval(CI): 75.12%-99.76%], 100%(95% CI: 46.29%-10 0%), 10 0%(95% CI: 80.76%-100%), 83.33%(95% CI: 36.48%-99.12%), and 96.30%(95% CI: 80.20%-99.99%), respectively. The subgroup analysis revealed that FNB could obtain sufficient specimens and high diagnostic yields in both gallbladder mass < 20.5 mm group and ≥20.5 mm group. One patient experienced mild abdominal pain after the procedure and recovered within one day. Conclusions: EUS-FNB is a reasonable diagnostic tool for the pretreatment diagnosis of patients with gallbladder masses, especially for patients who may miss the opportunity of surgery and need sufficient specimens to identify the pathological type so as to determine chemotherapy regimens. Further largescale studies are needed to confirm our conclusion.

Delayed hemorrhage from hepatic artery after ultrasound-guided percutaneous liver biopsy: A case report

Percutaneous liver biopsy is considered one of the most important diagnostic tools to evaluate diffuse liver diseases. Pseudoaneurysm of hepatic artery is an unusual complication after ultrasound-guided percutaneous liver biopsy. Delayed hemorrhage occurs much less frequently. We report a case of pseudoaneurysm of the hepatic artery of a 46-year-old man who was admitted for abdominal pain after 4 d of liver biopsy. The bleeding was controlled initially by angiographic embolization. However, recurrent bleeding could not be controlled by repeat angiography, and the patient died 4 d after admission from multiorgan failure. The admittedly rare possibility of delayed hemorrhage should be considered whenever a liver biopsy is performed.

Comprehensive review on endoscopic ultrasound-guided tissue acquisition techniques for solid pancreatic tumor

Pancreatic ductal adenocarcinoma is speculated to become the second leading cause of cancer-related mortality by 2030,a high mortality rate considering the number of cases.Surgery and chemotherapy are the main treatment options,but they are burdensome for patients.A clear histological diagnosis is needed to determine a treatment plan,and endoscopic ultrasound(EUS)-guided tissue acquisition(TA)is a suitable technique that does not worsen the cancer-specific prognosis even for lesions at risk of needle tract seeding.With the development of personalized medicine and precision treatment,there has been an increasing demand to increase cell counts and collect specimens while preserving tissue structure,leading to the development of the fine-needle biopsy(FNB)needle.EUS-FNB is rapidly replacing EUS-guided fine-needle aspiration(FNA)as the procedure of choice for EUS-TA of pancreatic cancer.However,EUS-FNA is sometimes necessary where the FNB needle cannot penetrate small hard lesions,so it is important clinicians are familiar with both.Given these recent developments,we present an up-to-date review of the role of EUS-TA in pancreatic cancer.Particularly,technical aspects,such as needle caliber,negative pressure,and puncture methods,for obtaining an adequate specimen in EUS-TA are discussed.

Histopathological impact of SARS-CoV-2 on the liver:Cellular damage and long-term complications

Coronavirus disease 2019(COVID-19),caused by the highly pathogenic severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),primarily impacts the respiratory tract and can lead to severe outcomes such as acute respiratory distress syndrome,multiple organ failure,and death.Despite extensive studies on the pathogenicity of SARS-CoV-2,its impact on the hepatobiliary system remains unclear.While liver injury is commonly indicated by reduced albumin and elevated bilirubin and transaminase levels,the exact source of this damage is not fully understood.Proposed mechanisms for injury include direct cytotoxicity,collateral damage from inflammation,drug-induced liver injury,and ischemia/hypoxia.However,evidence often relies on blood tests with liver enzyme abnormalities.In this comprehensive review,we focused solely on the different histopathological manifestations of liver injury in COVID-19 patients,drawing from liver biopsies,complete autopsies,and in vitro liver analyses.We present evidence of the direct impact of SARS-CoV-2 on the liver,substantiated by in vitro observations of viral entry mechanisms and the actual presence of viral particles in liver samples resulting in a variety of cellular changes,including mitochondrial swelling,endoplasmic reticulum dilatation,and hepatocyte apoptosis.Additional ly,we describe the diverse liver pathology observed during COVID-19 infection,encompassing necrosis,steatosis,cholestasis,and lobular inflammation.We also discuss the emergence of long-term complications,notably COVID-19-related secondary sclerosing cholangitis.Recognizing the histopathological liver changes occurring during COVID-19 infection is pivotal for improving patient recovery and guiding decision-making.

Staging liver fibrosis with various diffusion-weighted magnetic resonance imaging models

BACKGROUND Diffusion-weighted imaging(DWI)has been developed to stage liver fibrosis.However,its diagnostic performance is inconsistent among studies.Therefore,it is worth studying the diagnostic value of various diffusion models for liver fibrosis in one cohort.AIM To evaluate the clinical potential of six diffusion-weighted models in liver fibrosis staging and compare their diagnostic performances.METHODS This prospective study enrolled 59 patients suspected of liver disease and scheduled for liver biopsy and 17 healthy participants.All participants underwent multi-b value DWI.The main DWI-derived parameters included Mono-apparent diffusion coefficient(ADC)from mono-exponential DWI,intravoxel incoherent motion model-derived true diffusion coefficient(IVIM-D),diffusion kurtosis imaging-derived apparent diffusivity(DKI-MD),stretched exponential model-derived distributed diffusion coefficient(SEM-DDC),fractional order calculus(FROC)model-derived diffusion coefficient(FROC-D)and FROC model-derived microstructural quantity(FROC-μ),and continuous-time random-walk(CTRW)model-derived anomalous diffusion coefficient(CTRW-D)and CTRW model-derived temporal diffusion heterogeneity index(CTRW-α).The correlations between DWI-derived parameters and fibrosis stages and the parameters’diagnostic efficacy in detecting significant fibrosis(SF)were assessed and compared.RESULTS CTRW-D(r=-0.356),CTRW-α(r=-0.297),DKI-MD(r=-0.297),FROC-D(r=-0.350),FROC-μ(r=-0.321),IVIM-D(r=-0.251),Mono-ADC(r=-0.362),and SEM-DDC(r=-0.263)were significantly correlated with fibrosis stages.The areas under the ROC curves(AUCs)of the combined index of the six models for distinguishing SF(0.697-0.747)were higher than each of the parameters alone(0.524-0.719).The DWI models’ability to detect SF was similar.The combined index of CTRW model parameters had the highest AUC(0.747).CONCLUSION The DWI models were similarly valuable in distinguishing SF in patients with liver disease.The combined index of CTRW parameters had the highest AUC.

Recent advances in the diagnosis of drug-induced liver injury

Drug-induced liver injury(DILI)is a major problem in the United States,commonly leading to hospital admission.Diagnosing DILI is difficult as it is a diagnosis of exclusion requiring a temporal relationship between drug exposure and liver injury and a thorough work up for other causes.In addition,DILI has a very variable clinical and histologic presentation that can mimic many different etiologies of liver disease.Objective scoring systems can assess the probability that a drug caused the liver injury but liver biopsy findings are not part of the criteria used in these systems.This review will address some of the recent updates to the scoring systems and the role of liver biopsy in the diagnosis of DILI.

Endoscopic ultrasound-guided through-the-needle microforceps biopsy and needle-based confocal laser-endomicroscopy increase detection of potentially malignant pancreatic cystic lesions:A single-center study

BACKGROUND Currently,there is insufficient data about the accuracy in the diagnosing of pancreatic cystic lesions(PCLs),especially with novel endoscopic techniques such as with direct intracystic micro-forceps biopsy(mFB)and needle-based confocal laser-endomicroscopy(nCLE).AIM To compare the accuracy of endoscopic ultrasound(EUS)and associated techniques for the detection of potentially malignant PCLs:EUS-guided fine needle aspiration(EUS-FNA),contrast-enhanced EUS(CE-EUS),EUS-guided fiberoptic probe cystoscopy(cystoscopy),mFB,and nCLE.METHODS This was a single-center,retrospective study.We identified patients who had undergone EUS,with or without additional diagnostic techniques,and had been diagnosed with PCLs.We determined agreement among malignancy after 24-mo follow-up findings with detection of potentially malignant PCLs via the EUSguided techniques and/or EUS-guided biopsy when available(EUS malignancy detection).RESULTS A total of 129 patients were included, with EUS performed alone in 47/129. In 82/129 patients,EUS procedures were performed with additional EUS-FNA (21/82), CE-EUS (20/82), cystoscopy(27/82), mFB (36/82), nCLE (44/82). Agreement between EUS malignancy detection and the 24-mo follow-up findings was higher when associated with additional diagnostic techniques thanEUS alone [62/82 (75.6%) vs 8/47 (17%);OR 4.35, 95%CI: 2.70-7.37;P < 0.001]. The highestmalignancy detection accuracy was reached when nCLE and direct intracystic mFB were bothperformed, with a sensitivity, specificity, positive predictive value, negative predictive value andobserved agreement of 100%, 89.4%, 77.8%, 100% and 92.3%, respectively (P < 0.001 comparedwith EUS-alone).CONCLUSIONThe combined use of EUS-guided mFB and nCLE improves detection of potentially malignantPCLs compared with EUS-alone, EUS-FNA, CE-EUS or cystoscopy.

Endoscopic ultrasound-guided fine-needle aspiration biopsy-Recent topics and technical tips

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is a useful procedure that enables reliable pathological diagnoses of pancreatobiliary diseases, subepithelial lesions, and swollen lymph nodes. In recent years, a pathological diagnosis based on EUS-FNA has made it possible to provide accurate treatment methods not only in these fields, but also in respiratory organs and otorhinolaryngology. This review discusses the latest topics pertaining to EUS-FNA as well as procedural tips.

Septic shock due to Granulicatella adiacens after endoscopic ultrasound-guided biopsy of a splenic mass:A case report

BACKGROUND Endoscopic ultrasound-guided fine needle aspiration or biopsy(EUS-FNA or FNB)has become a popular method for diagnosing various lesions of the gastrointestinal tract and surrounding tissue due to the accuracy and safety.To the best of our knowledge,no case report of severe infection after EUS-FNB of a solid lesion in the spleen has been described.Herein,we report a rare case of septic shock after EUS-FNB of a splenic mass.CASE SUMMARY A 45-year-old male patient presented to the outpatient clinic due to an incidentally detected splenic mass.A definitive diagnosis could not be established based on the abdominal magnetic resonance imaging.EUS of the spleen showed a 6 cm-sized,relatively well-demarcated,heterogeneous mass,and EUS-FNB with a 22G needle was performed.Ten days after the procedure patient developed septic shock and a splenic abscess was identified.Blood culture revealed growth of Granulicatella adiacens.After the treatment with antibiotics the patient underwent surgical resection,and the pathological examination showed diffuse large B-cell lymphoma.The patient received chemotherapy and he is in complete remission.CONCLUSION Infection of a splenic mass after EUS-FNB is a rare complication and prophylactic antibiotics might be considered.

New Wireless Handheld Ultrasound-Guided Vacuum-Assisted Breast Biopsy (VABB) Devices: An Important Innovation in Breast Diagnosis

Vacuum-assisted breast biopsy (VABB) plays a fundamental role in the preoperative assessment of breast lesions pro- viding large histology samples that are useful to define diagnoses and biological parameters to guide treatment planning. This technique has been used in our institute since 2000 and two new wireless handheld ultrasound-guided VABB de- vices have been introduced since May 2012. In this report we analyze our experience with these revolutionary devices which are able to provide the option of single-insertion contiguous tissue samples respectively with a 13/14-gauge aperture. Our initial experience on 75 lesions shows that these devices are safe, fast, procedurally advantageous for operators and well accepted by patients. Finally VABB procedures can markedly reduce the need for surgical biopsy.

Staging the axilla in women with breast cancer: the utility of preoperative ultrasound-guided needle biopsy

Preoperative staging of the axilla in women with invasive breast cancer using ultrasound-guided needle biopsy(UNB) identifies approximately 50% of patients with axillary nodal metastases prior to surgical intervention. Although moderately sensitive, it is a highly specific staging strategy that is rarely falsely-positive, hence a positive UNB allows patients to be triaged to axillary lymph-node dissection(ALND) avoiding potentially unnecessary sentinel node biopsy(SNB). In this review, we extend our previous work through an updated literature search, focusing on studies that report data on UNB utility. Based on data for 10,934 breast cancer patients, sourced from 35 studies, a positive UNB allowed triage of 1,745 cases(simple proportion 16%) to axillary surgical treatment: the utility of UNB was a median 19.8% [interquartile range(IQR) 11.6%-26.7%] across these studies. We also modelled data from a subgroup of studies, and estimated that amongst patients with metastases to axillary nodes, the odds ratio(OR) for high nodal disease burden for a positive UNB versus a negative UNB was 4.38 [95% confidence interval(95% CI): 3.13, 6.13], P<0.001. From this model, the estimated proportion with high nodal disease burden was 58.9%(95% CI: 50.2%, 67.0%) for a positive UNB, whereas the estimated proportion with high nodal disease burden was 24.6%(95% CI: 17.7%, 33.2%) if UNB was negative. Overall, axillary UNB has good clinical utility and a positive UNB can effectively triage to ALND. However, the evolving landscape of axillary surgical treatment means that UNB will have relatively less utility where surgeons have modified their practice to omission of ALND for minimal nodal metastatic disease.