Damage Control Interventional Radiology: The bridge between non-operative management and damage control surgery.

Traumatic injuries continue to be on the rise globally and with it, the role interventional radiology (IR) has also expanded in managing this patient cohort. The role of damage control surgery (DCS) has been well established in the trauma management pathway, however it is only recently that Damage Control IR (DCIR) has become increasingly utilized in managing the extremis trauma and emergency patient.Visceral artery embolizations (both temporary and permanent), temporary balloon occlusions including Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in iliac arteries and aorta respectively are amongst the treatment options now available for the trauma (and non-traumatic bleeding) patient.We review the literature for the role of DCS and utilization of IR in trauma, outcomes and the paradigm shift towards minimally invasive techniques. The focus of this paper is to highlight the importance of multi-disciplinary working and having established pathways to ensure timely treatment of trauma patients as well as careful patient selection.We show that outcomes are best when both surgical and IR are involved in patient care from the outset and that DCIR should not be defined as Non-Operative Management (NOM) as it currently is categorized as.

A comprehensive diagnostic approach to differentiate intrauterine arteriovenous malformation in cases of enhanced myometrial vascularity.

PURPOSE: The differentiation between conditions such as uterine arteriovenous malformation, pseudoaneurysm, gestational trophoblastic disease, and retained trophoblastic tissue can be challenging. Ultrasound imaging and Doppler interrogation are the primary diagnostic tools to assess cases of enhanced myometrial vascularity and differentiate intrauterine vascular anomalies. However, some cases remain of difficult differentiation. This study aims to analyze suspected cases and describe their diagnostic management and outcomes. METHODS: We reviewed post-abortion cases that underwent pelvic transvaginal U/S imaging and Doppler examinations due to suspected uterine vascular anomalies. CT scans were performed in cases in which ultrasound did not reach a diagnosis. Simple follow-up, medical or surgical therapy, or embolization of uterine arteries were performed according to the final diagnosis. RESULTS: From 2015 to 2022, we retrieved from electronic ultrasound records 22 cases of suspected vascular malformations. In eight cases, first-line U/S at admission excluded the suspected anomaly. In Five of the remaining 14 patients, uterine vascular anomalies were excluded upon a second-level  U/S based on angio-Doppler imaging and Doppler peak velocity interrogation. Nine cases underwent CT scan, and a digital angiography and embolization were performed in eight of these cases, of whom only two had a documented uterine arteriovenous malformation. CONCLUSION: Our triage proved that only two out of 22 suspected cases had a uterine arteriovenous malformation. This diagnosis is frequently misused in clinical practice. Our data confirm that enhanced myometrial vascularity should be used to encompass the spectrum of possible differential diagnosis. A precise step-by-step diagnostic method is of paramount importance to prevent unnecessary interventions.

ESR Essentials: image guided drainage of fluid collections-practice recommendations by the Cardiovascular and Interventional Radiological Society of Europe.

This ESR Essentials article intends to provide detailed, step-by-step, information on the role of imaging in the diagnosis, procedural management, and follow-up of patients with fluid collections. Evidence-based medicine recommendations for the positioning of percutaneous drainages and/or for diagnostic/therapeutic aspiration of fluid collections are provided. Although medical history, clinical symptoms, physical examination, and laboratory tests can raise suspicions regarding a collection, an imaging assessment is usually necessary for the diagnosis. Radiologists can easily identify fluid collections that are clinically suspected by using a wide range of imaging modalities, such as ultrasound, CT, MRI, and cone-beam CT. Consequently, these imaging methods (either alone or combined), can be used to aspirate the collection or for the placement of a drainage catheter. The choice of imaging technique to be used is influenced by the location of the collection, operator preference, size, and content of the collection. In addition, it is of utmost importance to underline the role of the interventional radiologist in the management and follow-up of patients with percutaneous drains, in collaboration with surgeons, clinicians, and diagnostic radiologists. KEY POINTS: Indications for percutaneous imaging-guided drainage are supported by clinical findings, laboratory tests, and pre-procedural imaging. Deciding between aspiration or drain insertion should follow patient assessment and fluid collection characterization. The interventional radiologist should be part of the entire patient care process including follow-up.

Computed-Tomography-Guided Lung Biopsy: A Practice-Oriented Document on Techniques and Principles and a Review of the Literature.

Computed tomography (CT)-guided lung biopsy is one of the oldest and most widely known minimally invasive percutaneous procedures. Despite being conceptually simple, this procedure needs to be performed rapidly and can be subject to meaningful complications that need to be managed properly. Therefore, knowledge of principles and techniques is required by every general or interventional radiologist who performs the procedure. This review aims to contain all the information that the operator needs to know before performing the procedure. The paper starts with the description of indications, devices, and types of percutaneous CT-guided lung biopsies, along with their reported results in the literature. Then, pre-procedural evaluation and the practical aspects to be considered during procedure (i.e., patient positioning and breathing) are discussed. The subsequent section is dedicated to complications, with their incidence, risk factors, and the evidence-based measures necessary to both prevent or manage them; special attention is given to pneumothorax and hemorrhage. After conventional CT, this review describes other available CT modalities, including CT fluoroscopy and cone-beam CT. At the end, more advanced techniques, which are already used in clinical practice, like fusion imaging, are included.

Is it a complication or a consequence - a new perspective on adverse outcomes in Interventional Radiology.

The aim of the article is to introduce a new term in post-procedural events related to the procedure itself. All the Societies and Councils report these events as complications and they are divided in mild, moderate and severe or immediate and delayed.On the other hand the term error is known as the application of a wrong plan, or strategy to achieve a goal.For the first time, we are trying to introduce the term "consequence"; assuming that the procedure is the only available and the best fit to clinical indication, a consequence should be seen as an expected and unavoidable occurrence of an "adverse event" despite correct technical execution.

Clinical Impact of a Protocol Involving Cone-Beam CT (CBCT), Fusion Imaging and Ablation Volume Prediction in Percutaneous Image-Guided Microwave Ablation in Patients with Hepatocellular Carcinoma Unsuitable for Standard Ultrasound (US) Guidance.

PURPOSE: to evaluate the clinical impact of a protocol for the image-guided percutaneous microwave ablation (MWA) of hepatocellular carcinoma (HCC) that includes cone-beam computed tomography (CBCT), fusion imaging and ablation volume prediction in patients with hepatocellular carcinoma unsuitable for standard ultrasound (US) guidance. MATERIALS AND METHODS: this study included all patients with HCC treated with MWA between January 2021 and June 2022 in a tertiary institution. Patients were divided into two groups: Group A, treated following the protocol, and Group B, treated with standard ultrasound (US) guidance. Follow-up images were reviewed to assess residual disease (RD), local tumor progression (LTP) and intrahepatic distant recurrence (IDR). Ablation response at 1 month was also evaluated according to mRECIST. Baseline variables and outcomes were compared between the groups. For 1-month RD, propensity score weighting (PSW) was performed. RESULTS: 80 consecutive patients with 101 HCCs treated with MWA were divided into two groups. Group A had 41 HCCs in 37 patients, and Group B had 60 HCCs in 43 patients. Among all baseline variables, the groups differed regarding their age (mean of 72 years in Group A and 64 years in Group B, respectively), new vs. residual tumor rates (48% Group A vs. 25% Group B, p < 0.05) and number of subcapsular tumors (56.7% Group B vs. 31.7% Group A, p < 0.05) and perivascular tumors (51.7% Group B vs. 17.1% Group A, p < 0.05). The protocol led to repositioning the antenna in 49% of cases. There was a significant difference in 1-month local response between the groups measured as the RD rate and mRECIST outcomes. LTP rates at 3 and 6 months, and IDR rates at 1, 3 and 6 months, showed no significant differences. Among all variables, logistic regression after PSW demonstrated a protective effect of the protocol against 1-month RD. CONCLUSIONS: The use of CBCT, fusion imaging and ablation volume prediction during percutaneous MWA of HCCs provided a better 1-month tumor local control. Further studies with a larger population and longer follow-up are needed.

Performance and Safety of a Reflux-Control Microcatheter Used to Perform DEB-TACE with LUMITM Beads in HCC Patients: Preliminary Experience.

PURPOSE: The present study aims to evaluate the effectiveness and safety of the anti-reflux microcatheter during DEB-TACE with DC Bead LUMITM (radiopaque beads) for the treatment of hepatocellular carcinoma (HCC). METHODS: We performed an observational longitudinal prospective monocentric study to analyze all patients with HCC who underwent to DEB-TACE with DC Bead LUMITM and anti-reflux microcatheter. Technical success, the presence of residual disease, and clinical success were evaluated. The performance of the anti-reflux microcatheter on the basis of the percentage of tumor covered and the non-target embolization (NTE) was also evaluated. RESULTS: Twenty patients underwent DEB-TACE with DC Bead LUMITM and an anti-reflux microcatheter. Technical success was achieved in all cases. Residual disease in the target tumor was observed in 11/20 (55%) of cases and no residual disease was found in 9/20 (45%) of cases. The clinical response at 1-month follow-up was of PD 4/20 (20%), SD 7/20 (35%), and CR 9/20 (45%). No major complications were recorded, and 10% of cases had minor complications. The distribution of beads on post-procedural CBCT, classified according to the percentage of target nodule coverage, was ≥50% in 70% (14/20) of cases and between 30-50% in 30% of cases (6/20). NTE was never registered.

Percutaneous Application of High Power Microwave Ablation With 150†W for the Treatment of Tumors in Lung, Liver, and Kidney: A Preliminary Experience.

OBJECTIVE: The aim of this study is to evaluate the feasibility, safety, and short-term effectiveness of a high-power (150 W) microwave ablation (MWA) device for tumor ablation in the lung, liver, and kidney. METHODS: Between December 2021 and June 2022, patients underwent high-power MWA for liver, lung, and kidney tumors. A retrospective observational study was conducted in accordance with the Declaration of Helsinki. The MWA system utilized a 150-W, 2.45-GHz microwave generator (Emprint™ HP Ablation System, Medtronic). The study assessed technical success, safety, and effectiveness, considering pre- and post-treatment diameter and volume, lesion location, biopsy and/or cone beam computed tomography (CBCT) usage, MWA ablation time, MWA power, and dose-area product (DAP). RESULTS: From December 2021 to June 2022, 16 patients were enrolled for high-power MWA. Treated lesions included hepatocellular carcinoma (10), liver metastasis from colon cancer (1), liver metastasis from pancreatic cancer (1), squamous cell lung carcinoma (2), renal cell carcinoma (1), and renal oncocytoma (1). Technical success rate was 100%. One grade 1 complication (6.25%) was reported according to CIRSE classification. Overall effectiveness was 92.8%. Pre- and post-treatment mean diameters for liver lesions were 19.9 mm and 37.5 mm, respectively; for kidney lesions, 34 mm and 35 mm; for lung lesions, 29.5 mm and 31.5 mm. Pre- and post-treatment mean volumes for liver lesions were 3.4 ml and 24 ml, respectively; for kidney lesions, 8.2 ml and 20.5 ml; for lung lesions, 10.2 ml and 32.7 ml. The mean ablation time was 48 minutes for liver, 42.5 minutes for lung, and 42.5 minutes for renal ablation. The mean DAP for all procedures was 40.83 Gcm2. CONCLUSION: This preliminary study demonstrates the feasibility, safety, and effectiveness of the new 150 W MWA device. Additionally, it shows reduced ablation times for large lesions.

Efficacy and Safety of Transarterial Chemoembolization with DC Beads LUMI in the Treatment of HCC: Experience from a Tertiary Centre.

PURPOSE: The aim of this study was to describe the safety and efficacy profiles of TACE using DC Beads LUMI. MATERIALS AND METHODS: We retrospectively analyzed 90 patients with HCC who underwent TACE with DC Bead LUMI™ between November 2018 and November 2020 at Fondazione IRCCS Cà Granda Policlinico Hospital in Milan, Italy. Patient- and tumour-related factors were registered, including the number of treated lesions, dose of DC Beads LUMI™, dose of Epirubicin, DC Beads LUMI™ target tumour coverage (LC) according to the percentage of target nodule involvement (LC1-0%-25%, LC2-25%-50%, LC3-50%-75%, LC4 75%-100%). Treatment efficacy was obtained through reviewing the follow-up imaging for evidence of response in target lesion(s), according to modified response criteria in solid tumours (mRECIST) criteria with the following outcomes: complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD). Safety assessment was based on the quantitative and qualitative recording of the adverse events, classified according to CIRSE classification. RESULTS: Seventy-two patients were enrolled, and 95 procedures were carried out. We observed a target tumour response rate at 1 month with CR in 68%, PR in 10.3% 11.8%, SD in 13%, PD in 7.2%, and an overall tumour(s) (whole liver) response at 1 month with CR in 58.9%, PR in 12.6%, SD in 10.5% and PD in 18%. We found a significant association (p < 0.01) between tumour response CR or CR + PR and the number of the target lesion(s). CIRSE classification grade I and grade II complications were recorded, respectively, in 11 (11.6%) and 6 (6.3%) procedures. No grade III-IV-V complications occurred. CONCLUSION: TACE using DC Beads LUMI is a safe and effective treatment option for patients with HCC.

Locoregional Therapies and Remodeling of Tumor Microenvironment in Pancreatic Cancer.

Despite the advances made in treatment, the prognosis of pancreatic ductal adenocarcinoma (PDAC) remains dismal, even in the locoregional and locally advanced stages, with high relapse rates after surgery. PDAC exhibits a chemoresistant and immunosuppressive phenotype, and the tumor microenvironment (TME) surrounding cancer cells actively participates in creating a stromal barrier to chemotherapy and an immunosuppressive environment. Recently, there has been an increasing use of interventional radiology techniques for the treatment of PDAC, although they do not represent a standard of care and are not included in clinical guidelines. Local approaches such as radiation therapy, hyperthermia, microwave or radiofrequency ablation, irreversible electroporation and high-intensity focused ultrasound exert their action on the tumor tissue, altering the composition and structure of TME and potentially enhancing the action of chemotherapy. Moreover, their action can increase antigen release and presentation with T-cell activation and reduction tumor-induced immune suppression. This review summarizes the current evidence on locoregional therapies in PDAC and their effect on remodeling TME to make it more susceptible to the action of antitumor agents.

Percutaneous Microwave Ablation of Hepatocellular Carcinoma with "Double Fusion" Technique: Technical Note and Single-Center Preliminary Experience.

Percutaneous image-guided thermal ablation is included in most society guidelines for treatment of hepatocellular carcinoma (HCC). The results of this treatment in terms of efficacy depend on the ability to precisely place the device into the target tumor. Ultrasound (US) is a commonly used imaging guidance modality for its real-time feedback. However, an accurate device deployment remains challenging in some clinical scenarios, including cases of tumors that are undetectable or not clearly visible by US. To overcome this problem, fusion imaging techniques have been developed, which combine images from different modalities. The most widely known technique combines pre-procedural contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) with real-time US scans. Cone beam CT (CBCT) is a technology that can provide intra-procedural cross-sectional images, which can be registered to images from other modalities, including preprocedural CT/MR scans. The aim of our study is to report the preliminary experience on percutaneous microwave ablation (MWA) of patients with HCC that were treated using the "double fusion" technique, which combines the use of US fusion imaging and CBCT fusion imaging. We describe the technical details, feasibility, safety and short-term efficacy of this technique in a small series of eight patients with 11 HCCs.

Emergent vessel embolization for major traumatic and non-traumatic hemorrhage: Indications, tools and outcomes.

Endovascular embolization of bleeding vessels in trauma and non-trauma patients is frequently used and is an important tool for bleeding control. It is included in the EVTM (endovascular resuscitation and trauma management) concept and its use in patients with hemodynamic instability is increasing. When the correct embolization tool is chosen, a dedicated multidisciplinary team can rapidly and effectively achieve bleeding control. In this article, we will describe the current use and possibilities for embolization of major hemorrhage (traumatic and non-traumatic) and the published data supporting these techniques as part of the EVTM concept.

Advances in Imaging Guidance During Percutaneous Ablation of Renal Tumors.

Currently, minimally invasive ablative techniques for the treatment of renal tumors have become a more common and feasible treatment option. New imaging technologies have been implemented and successfully merged with each other to improve the guidance of tumor ablation. In the present review, an overview of the real-time fusion of multiple imaging modalities, robotic and electromagnetic navigation and the application of artificial intelligence software, in field of tumor renal ablation treatment, are analyzed.

Effectiveness and Safety of Different Vascular Closure Devices: Multicentre Prospective Observational study.

AIM: The aim of this prospective, multicentre, observational study was to compare the efficacy and safety of balloon-based and non-balloon-based vascular closure devices (VCDs). MATERIALS AND METHODS: From March 2021 to May 2022, 2373 participants from 10 different centres were enrolled. Among them, 1672 patients with 5-7 Fr accesses were selected. Successful haemostasis, failure and safety were evaluated. Successful haemostasis was defined as the possibility to obtain complete haemostasis with the use of VCDs, without any complication. Failure management was defined as the need of manual compression. Safety was defined as the rate of complications. Cases of haematomas/pseudoaneurysms (PSA) and artero-venous fistula (AVF) were collected. RESULTS: VCDs mechanism of action is statistically significant associated with the outcome. Non-balloon-based VCDs demonstrated a statistically significant better outcome: successful haemostasis was obtained in 96.5% vs. 85.9%, of cases when compared to balloon occluders (p < 0.001). The incidence of AVF was statistically more frequent using non-balloon occluders devices (1.57% vs 0%, p: 0.007). No significant statistical difference was found in comparing haematoma and PSA occurrence. Thrombocytopenia, coagulation deficit, BMI, diabetes mellitus and anti-coagulation were demonstrated to be independent predictors of failure management. CONCLUSION: Our study suggests a better outcome with the same complication rate, except that for AVF incidence for non-balloon collagen plug device if compared to balloon occluders vascular closure devices.

Could Maximum SUV be Used as Imaging Guidance in Large Lung Lesions Biopsies? Double Sampling Under PET-CT/XperGuide Fusion Imaging in Inhomogeneous Lung Uptaking Lesions to Show That it can Make a Difference.

Introduction: The purpose of this study is to evaluate the diagnostic value of positron emission computed tomography-cone beam computed tomography (PET/CT-CBCT) fusion guided percutaneous biopsy, targeted to the maximum standardized uptake value (SUVmax) and minimum standardized uptake value (SUVmin) of large lung lesions. Materials and Methods: Inside a larger cohort of PET/CT-CBCT guided percutaneous lung biopsies, 10 patients with large pulmonary lesions (diameter > 30 mm) were selected retrospectively. These patients have been subjected to double biopsy sampling respectively in the SUVmax area and in the SUVmin area of the lesion. Technical success has been calculated. For each sample, the percentage of neoplastic, inflammatory, and fibrotic cells was reported. Furthermore, the possibility of performing immunohistochemical or molecular biology investigations to specifically define the biomolecular tumor profile was analyzed. Results: Nine lesions were found to be malignant, one benign (inflammation). Technical success was 100% (10/10) in the SUVmax samples and 70% (7/10) in the SUVmin samples (P-value: .21). In the first group, higher percentages of neoplastic cells were found at pathologic evaluation, while in the second group areas of inflammation and fibrosis were more represented. The biomolecular profile was obtained in 100% of cases (9/9) of the first group, while in the second group only in 33.3% of cases (2/6), with a statistically significant difference between the 2 groups (P-value: .011). Conclusion: A correlation between the standardized uptake value value and the technical success of the biopsy sample has been identified. PET/CT-CBCT guidance allows to target the biopsy in the areas of the tumor which are richer in neoplastic cells, thus obtaining more useful information for the planning of patient-tailored cancer treatments.

Robotics in Interventional Radiology: Review of Current and Future Applications.

This review is a brief overview of the current status and the potential role of robotics in interventional radiology. Literature published in the last decades, with an emphasis on the last 5 years, was reviewed and the technical developments in robotics and navigational systems using CT-, MR- and US-image guidance were analyzed. Potential benefits and disadvantages of their current and future use were evaluated. The role of fusion imaging modalities and artificial intelligence was analyzed in both percutaneous and endovascular procedures. A few hundred articles describing results of single or several systems were included in our analysis.

Ablative Therapies for Breast Cancer: State of Art.

Breast cancer (BC) is the most frequently diagnosed malignancy among women. In the past two decades, new technologies and BC screening have led to the diagnosis of smaller and earlier-stage BC (ESBC). Therefore, percutaneous minimally invasive techniques (PMIT) were adopted to treat patients unfit for surgery, women who refuse it, or elderly patients with comorbidities that could make surgery a difficult and life-threatening treatment. The target of PMIT is small-size ESBC with the scope of obtaining similar efficacy as surgery. Minimally invasive treatments are convenient alternatives with promising effectiveness, lower morbidity, less cost, less scarring and pain, and more satisfying cosmetic results. Ablative techniques used in BC are cryoablation, radiofrequency ablation, microwave ablation, high-intensity focused ultrasound (US), and laser ablation. The aim of our study is to discuss the current status of percutaneous management of BC, evaluate the clinical outcomes of PMIT in BC, and analyze future perspectives regarding ablation therapy in BC.

Pressure cooker technique in cerebral AVMs and DAVFs: different treatment strategies.

BACKGROUND: The pressure cooker technique (PCT) was developed to enable safer and more extensive embolization of hypervascular lesions by simultaneously minimizing backflow of liquid embolic materials and thus reduce the risk of non-target embolization of adjacent healthy vessels. We report our experience in applying the PCT to cerebral arteriovenous malformations (AVMs) and dural arteriovenous fistulas (DAVFs) and additionally suggest our technical adjustments. METHODS: We retrospectively reviewed all patients suffering from AVMs or DAVFs that were treated with the PCT between 2018 and 2020 in two university hospitals. The endpoints of the study were clinical safety and the technical efficacy. The endpoints of the study were clinical safety and the technical efficacy. Clinical safety was the absence of death, major or minor symptomatic stroke, TIA and procedure-related intracranial bleeding (SAH) in the peri-procedural period until dismission. Good clinical outcome was defined as no deterioration of the modified Rankin Scale (mRS) score (comparing the pre- and post-procedural mRS evaluated by a trained neurologist at admission and dismission). The technical efficacy was considered as the complete embolization occlusion of the target vessels of the lesion documented on the final control angiogram. Long-term follow-up evaluation was not intended for this study as it was not available for all patients. RESULTS: Fifteen consecutive patients (6 women; mean age 55 y; range 20-82 y) with seven AVMs and eight DAVFs met the inclusion criteria. The primary clinical safety end point was obtained in all cases as no intraprocedural complications were encountered. All patients had a good clinical outcome with no difference between the pre- and post-mRS scores. The primary efficacy end point was reached in all cases. CONCLUSION: The PCT is a safe and effective technique in the treatment of cerebral AVMs and DAVFs. Adding an easy and fast step to the procedure, namely the injection of contrast media to test the complete obstruction by the plug, the risk of reflux seems to additionally be reduced.

Association between anatomic variations of extrahepatic and intrahepatic bile ducts: Do look up!

Biliary anatomic variations are usually asymptomatic, but they may cause problems in diagnostic investigations and interventional and surgical procedures, increasing both their technical difficulty and their postoperative complication rates. The aim of the present study was to evaluate the prevalence of anatomic variations in the intrahepatic biliary ducts (IHBD) in relation to demographical and clinical characteristics in a large study population requiring magnetic resonance cholangiopancreatography (MRCP) for various clinical conditions. The possible association between IHBD and extrahepatic biliary ducts (EHBD) variants was then explored. From January 2017 to May 2019, 1004 patients underwent MRCP. Demographical and clinical data were collected. IHBD and EHBD anatomy were recorded and the EHBD anatomy was classified using both qualitative and quantitative classifications. The presence of a type 3 EHBD variant (an abnormal proximal cystic duct [CD] insertion) in both qualitative and quantitative classifications and an intrapancreatic CD were associated with the presence of IHBD variants at univariate analysis (p = 0.008, p = 0.019, and p = 0.001, respectively). The presence of a posterior or medial insertion of the CD into the EHBD was a strong predictive factor of the presence of IHBD variants both at uni- and multivariate analysis (p = 0.002 and p = 0.003 for posterior insertion and p = 0.002 and p = 0.002 for medial insertion, respectively). The presence of gallstones on MRCP resulted in a strong predictor of the presence of an anatomical variant of the IHBD both at uni- and multivariate analysis (p = 0.027 and p = 0.046, respectively). In conclusion, the presence of a type 3 variant of the EHBD, an intrapancreatic CD and, especially, a posterior/medial CD insertion into the EHBD represent predictive factors of the concomitant presence of IHBD variants, thus radiologists must be vigilant when encountering these EHBD configurations and always remember to "look up" at the IHBD. Finally, the presence of an IHBD variant is a strong predictive factor of gallstones.