Introduction

Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) is a reliable and minimally invasive method for obtaining tissue samples from organs like the pancreas, adrenal glands, and liver [1]. However, challenges in obtaining sufficient tissue samples persist due to limitations of needles, including design and materials [2]. To overcome these limitations, various FNB needles with different tip design and materials, such as Franseen and fork-tip needles, have been developed [3]. Nevertheless, ongoing enhancement of FNB needles remains crucial for increasing the diagnostic yield and efficacy of EUS-FNB.

Aims & Methods

This study aimed to compare the efficacy of newly designed Tricore needles with Franseen needles in a porcine liver model under EUS guidance. A total of four male Yorkshire pigs were randomly divided into two groups: the Franseen group and the Tricore group. Nine EUS-FNB procedures were performed on each pig using three FNB needles. All pigs were euthanized immediately after the final procedure. The maximum resistance force during the puncture and the angle of the FNB needle tip was measured to compare puncture performance of two FNB needles. Visibility under ultrasound, blood contamination, and tissue acquisition time were also evaluated immediately after the EUS-FNB procedure. The sufficiency of the specimen for diagnosis was assessed by measuring the total specimen area, number of fragments, fragment areas, and number of complete portal tracts (CPTs).

Results

Procedural outcomes were successful with no complications observed, yielding specimens with a 100% (36/36) success rate. The Franseen needle (5.97 ± 0.53 N) exhibited significantly higher resistance compared to the Tricore needle (3.83 ± 0.84 N, P < 0.001). The both needle tips were observed considerable bending pre- and post-procedure (P < 0.01); however, the Franseen needle (84.58 ± 39.69°) became more significantly bent than the Tricore needle (32.82 ± 14.17°, P < 0.001). The visibility under ultrasound of the Tricore needle was significantly higher than that of the Franseen group (P < 0.01). While blood contamination was similar between groups (P = 0.926), the Franseen group (59.90 ± 19.15 s) required significantly longer acquisition time than the Tricore group (48.94 ± 9.26 s, P < 0.05). Histological findings revealed significantly larger total specimen area (P < 0.05) and fragment area (P < 0.001) in the Tricore group compared to the Franseen group. Additionally, the Tricore group exhibited significantly higher number of CPTs (P < 0.05).

Conclusion

In conclusion, our study demonstrated that the newly designed Tricore EUS-FNB needle exhibits superior puncture ability and ultrasound visibility, while acquiring liver tissue specimens of greater quantity and quality compared to the commercially available Franseen needle. These findings suggest that the Tricore needle may offer a promising alternative for EUS-FNB procedures. Although further clinical validation is needed to confirm these findings, this novel needle design holds potential for improving the diagnostic yield and efficacy of EUS-FNB in clinical practice.

References

[1] Tanisaka, Y. et al. Comparison of Endoscopic Ultrasound-Guided Fine-Needle Aspiration and Biopsy Device for Lymphadenopathy. Gastroenterol Res Pract 2021, 6640862, doi:10.1155/2021/6640862 (2021).
[2] Song, T. J. et al. The prospective randomized, controlled trial of endoscopic ultrasound-guided fine-needle aspiration using 22G and 19G aspiration needles for solid pancreatic or peripancreatic masses. Am J Gastroenterol 105, 1739-1745, doi:10.1038/ajg.2010.108 (2010).
[3] Mohan, B. P. et al. Comparison of Franseen and fork-tip needles for EUS-guided fine-needle biopsy of solid mass lesions: A systematic review and meta-analysis. Endosc Ultrasound 8, 382-391, doi:10.4103/eus.eus_27_19 (2019).

Introduction

Malignant biliary obstruction (MBO) poses significant therapeutic challenges, particularly in patients ineligible for surgery [1]. Endobiliary radiofrequency ablation (RFA) has emerged as a promising palliative therapy, aiming to enhance stent patency and patient survival [2]. However, conventional catheter-based electrodes may encounter limitations, such as incomplete tumor ablation due to insufficient contact with the inner wall of the bile duct [3].

Aims & Methods

This study aimed to validate the feasibility of the stent-based electrode (SBE)-RFA system with polarity-switching and evaluate its efficacy in achieving circumferential ablation lesions in the porcine bile duct. A bipolar SBE consisting of two electrodes fabricated by braiding nitinol wires was designed and characterized along with a custom RFA generator capable of a polarity-switching system. Ex vivo studies using porcine livers were performed to evaluate the ablation ranges under various ablation protocols combining output power and ablation times. Subsequently, an animal study involving nine male Yorkshire pigs was performed, employing selected protocols based on ex vivo findings. The RFA procedure was conducted in the porcine common bile duct (CBD) under fluoroscopic guidance, with pre- and post-procedural assessments including cholangiography, endoscopic examination, and histological analysis.

Results

The SBE with custom RFA generator was demonstrated that temperature feedback and power output were accurate and showed high reproducibility. The SBE was successfully positioned at the correct location during the procedure through fluoroscopy and ultrasound guidance, and complete contact with the bile duct wall was confirmed. The ablation ranges of the porcine liver increased with output power and time, showing proportional growth and an even ablation area between electrodes. Endobiliary RFA in the porcine CBD was technically successful without ductal perforation, resulting in luminal narrowing proportional to output power and ablation time. Mucosal damage, including hemorrhagic erosion and erythema, was observed, intensifying with higher RFA-related parameters. Histological examination revealed increased inflammatory cell infiltration, hemorrhage, and cellular necrosis in correlation with output power and time. Additionally, the ablation area in the porcine CBD was formed in an even circumferential shape, and this also proportionally increased as output power and time increased.

Conclusion

In conclusion, this study demonstrates the technical feasibility and efficacy of endobiliary RFA utilizing a novel bipolar SBE-RFA system with polarity-switching system. This system exhibited controlled and predictable ablation ranges in the porcine CBD, offering potential as a palliative therapeutic option for unresectable MBO. Although further studies in obstructive animal models and long-term efficacy assessments are necessary, these findings suggest that promising prospects form the clinical application of the bipolar SBE-RFA system in managing MBO.

References

[1] Sumiyoshi T, Shima Y, Okabayashi T, Negoro Y, Shimada Y, Iwata J, et al. Chemoradiotherapy for Initially Unresectable Locally Advanced Cholangiocarcinoma. World J Surg. 2018;42(9):2910-8.
[2] Oh D, Chong J, Song TJ, Park DH, Lee SS, Seo DW, et al. The usefulness of endobiliary radiofrequency ablation before metal stent placement in unresectable malignant hilar obstruction. J Gastroenterol Hepatol. 2022;37(11):2083-90.
[3] Inoue T, Yoneda M. Updated evidence on the clinical impact of endoscopic radiofrequency ablation in the treatment of malignant biliary obstruction. Dig Endosc. 2022;34(2):345-58.

Introduction

Liver biopsy is a crucial diagnostic procedure for assessing hepatic pathologies, providing valuable insights into the etiology, severity, and prognosis of liver diseases. In recent years, Endoscopic Ultrasound-Guided Liver Biopsy (EUS-LB) using 22G- fine needle biopsy ( FNB) needle has emerged as a promising alternative, leveraging the superior imaging capabilities of endoscopic ultrasound (EUS) to guide biopsy with increased precision and safety. The 22G- FNB needle features a crown tip with three symmetrical cutting edges that enable swift core tissue procurement for histological analysis. The 22G- FNB needle provide greater than 95% tissue adequacy and an excellent diagnostic accuracy.

Aims & Methods

The aim of our study is to evaluate the diagnostic utility and safety of a 22G-FNB needle using the slow -pull technique for EUS-LB of parenchymal and focal liver lesions.
We performed a retrospective analysis of prospective data basefrom January 2021 to March 2024. Each patient underwent anendoscopic ultrasound by using linear scope (Fujifilm EG-580UT) and fine needle biopsy using 22G - tip needle with the slow-pull aspiration technique:

• For 33 patients we used a 22G Trident™ - tip FNB needle (Micro-Tech Endoscopy);
• For 26 patients we used a 22G Acquire- tip FNB needle (Boston Scientific Corp.);
  
• For 4 patients we used a 22G SonoTip Top Gain - tip FNB needle ( MediGlobe);

Results

We identified 63 patients who underwent EUS-LB of the liver during the study period(28 men and 35 women): 47 (74.6%)of them were with malignant and 16 (25.4%)–with benign disease. The medium age of the patients was 56.9 years. The specimen was considered adequate in all 63 patients.
We classified the EUS-FNB of liver diseases into EUS-FNB of parenchymal and focal liver lesions.

• EUS-FNB of parenchymal liver disease were performed to 13 (20.6%) of the patients: cirrhosis was found in 2 (3.17%), nonalcoholic fatty liver disease – in 5 (7.9%) and cholestasis in 6 (9.5%).
• We performed EUS-FNB of focal liver lesions in 50 ( 79.36%) of the patients.
  
  • Metastasis were found in 39 (61,9%): pancreatic ductal adenocarcinoma was detected in 27 (42.8%), pancreatic acinar cell carcinoma – in 1 (1.58%), pancreatic neuroendocrine carcinoma – in 5 (7.9%), lung adenocarcinoma – in 3 (4.7%), ductal adenocarcinoma of breast – in 2 (3.17%) , colorectal adenocarcinoma – in 1 (1.58%) and Ewing sarcoma – in 1 (1.58%).
  • Primary liver cancer - hepatocellular cancer was diagnosed in 4 (6.34%) patients.
    
  • Cholangiocarcinoma was found in 3 (4.7%) patients.
  • There were 3 (4.7%) patients with negative histology for tumor cells in the specimen: in 2 (3.17%) cases liver abscess was proved and 1 (1.58%) hepatic cyst.
    

Conclusion

Our study illustrates that ЕUS-guided liver biopsy using a 22 G- FNB needle provides adequate specimen for histologic analysis, lesser postprocedural recovery time and it is a safe, highly effective alternative to other methods of liver biopsy. The use of real time imaging guidance with doppler also helps to reduce the adverse events.

Introduction

Minimally invasive irreversible electroporation (IRE) has gained increasing attention for the treatment of endobiliary tumors.^[1-3] However, the clinical application of IRE in hollow organs has been limited due to the lack of suitable electrode designs that can ensure sufficient electrode-tissue contact.^[4] Recently, a novel stent-directed electrode (SDE) made of chemically polished nickel-titanium (Ni-Ti) alloy wires was developed for localized endobiliary IRE.

Aims & Methods

The aim of this study was to investigate feasibility and efficacy of localized IRE using a SDE in both in vitro and in vivo models. Ni-Ti wires were chemically polished to improve surface roughness and electrical conductivity. The SDE was fabricated using the polished wires, and its mechanical properties were characterized. The cytotoxicity and cell viability after IRE treatment were investigated using a colon cancer cell line. The optimal IRE parameter for the in vivo study was determined through triphenyl tetrazolium chloride-stained potato model (field strength: 500 V/cm, pulse width: 100 μs, pulse interval: 2,000 μs, number of pulses: 32). Subsequently, the safety and efficacy of endobiliary IRE using the SDE were evaluated in a porcine common bile duct model.

Results

The chemical polishing process significantly improved the surface roughness, current density, and electrical conductivity of the polished Ni-Ti wires while maintaining their mechanical properties compared with the control wire (p < 0.001). The polished Ni-Ti wire electrode effectively delivered electrical energy to cancer cells, cytotoxicity and cell viability were proportionally decreased according to the electric field strength increased (p < 0.001). IRE-treated potato tissue clearly revealed irreversibly and reversibly electroporated areas containing dead cells in electrical strength-dependent manner. In vivo studies showed that the SDE could be successfully delivered to the target site and achieve uniform and localized ablation of the ductal mucosa without causing severe complications. Histological analyses showed significantly increased apoptosis (p < 0.001), heat shock protein expression (p < 0.01), and inflammatory cell infiltration (p < 0.05) in the IRE-treated tissues compared to the sham control group.

Conclusion

The novel SDE made of chemically polished Ni-Ti wires demonstrated excellent performance for endobiliary IRE in terms of surface characteristics, electrical properties, and ablation efficacy. The in vivo experiments confirmed the safety and efficacy of the stent-directed IRE using the SE for the treatment of endobiliary tumors in a porcine model. These results suggest that this minimally invasive technique may provide a promising treatment option for endobiliary tumors of the gastrointestinal and urinary tracts. Additional preclinical and clinical studies are necessary to assess the long-term safety and efficacy of this technique for various clinical applications.

References

[1] Al-Sakere, B.; André, F.; Bernat, C.; Connault, E.; Opolon, P.; Davalos, R. V.; Rubinsky, B.; Mir, L. M. Tumor Ablation with Irreversible Electroporation. PLoS One 2007, 2, No. e1135.
[2] Silk, M.; Tahour, D.; Srimathveeravalli, G.; Solomon, S. B.; Thornton, R. H. The State of Irreversible Electroporation in interventional Oncology. In Seminars in interventional radiology; Thieme Medical Publishers, 2014; pp. 111−117.
[3] Wagstaff, P. G. K.; Buijs, M.; van den Bos, W.; de Bruin, D. M.; Zondervan, P. J.; de la Rosette, J. J.; Pes, M. P. L. Irreversible Electroporation: State of the Art. OncoTargets Ther. 2016, 2437−2446.
[4] Sánchez-Velázquez, P.; Castellví, Q.; Villanueva, A.; Quesada, R.; Pañella, C.; Cáceres, M.; Dorcaratto, D.; Andaluz, A.; Moll, X.; Trujillo, M.; Burdío, J. M.; Berjano, E.; Grande, L.; Ivorra, A.; Burdío, F. Irreversible Electroporation of the Liver: Is There a Safe Limit to the Ablation Volume? Sci. Rep. 2016, 6, 23781.

Introduction

Despite the introduction into clinical practice of serological neoplastic biomarkers and typical radiological characteristics, useful for the differential diagnosis of focal liver lesions, liver biopsy (LB) is still often necessary, especially in unclear cases, to achieve histological diagnosis. Nowadays, LB via percutaneous approach (PC-LB), under computed tomography (CT) scan or ultrasonograpy (US) guidance, is the route of choice. However, there are focal liver lesions that are poorly reachable via percutaneous approach. In these cases endoscopic ultrasound (EUS) guided fine needle biopsy (FNB) may be represents an attractive minimally invasive alternative.

Aims & Methods

Aim of this retrospective observational study was to evaluate the efficacy, diagnostic performances and safety of EUS-FNB of focal liver lesions. The indication to perform EUS-LB was the presence of a focal liver lesion poorly accessible via a percutaneous approach or incidentally found during an EUS examination

Results

58 patients were included, 43 patients had a final diagnosis of malignancy. The localization of lesions was 72.4 % (42 cases) in the left lobe and 27.6 % (16 cases) in the right lobe. The focal liver lesions localizations were summarized in Table 2. The median number of needle passes was 2 (IQR: 3–4). Only in 3 cases (5 %) the specimen was suboptimal for histological evaluation and in all of these, the focal liver lesions were located in right lobe. The overall sensitivity and specificity were 95% and 100% respectively while overall adequacy and accuracy were 95 % and 96% respectively. Subgroup analysis, conducted for different gauge FNB needles used, showed different diagnostic yeld. In particular, adequacy and accuracy for 19-gauge FNB needle were 100% and 95%, adequacy and accuracy were both 100 % for 20-gauge FNB needle and were 90% and 96% for 22-gauge FNB needle. Of note, all three inadequate biopsies were performed with a 22-gauge needle. On the other hand, subgroup analysis for different FNB needle type used, showed adequacy and accuracy of 94 % and 95% respectively for Acquire needle (Boston Scientific, Natick, MA, United States) and, adequacy and accuracy of both 100% for ProCore needle (Cook Medical Inc., Winston-Salem, North Carolina, United States). Technical success was 100% both for right and left liver lobe. Adequacy for focal liver lesion located in left and right lobe was 100 % and 81.2 % respectively and the difference was statistically significant [p= 0.001]. We also compared the diagnostic yield of EUS‑LB between the right lobe and left lobe mass. Median size of lesions on EUS and median number of needle passes did not differ significantly between the left and right lobes. Sensitivity for lesions located in left liver lobe and right liver lobe were 96 % and 91% respectively [p=0.001]. Specificity was 100% for lesions located in left and right liver lobe. Predictive positive value (PPV) was 100% for lesions located in both liver lobe. Predictive negative value (PPV) for lesions located in left liver lobe and right liver lobe were 90% and 50% respectively [p= 0.001]. No intra/postprocedural adverse events were recorded according to AGREE classification.

Conclusion

EUS-guided focal liver lesions biopsy using FNB is effective in achieving accurate diagnosis with an excellent safety profile. The main indication for EUS-FNB of focal liver lesions could be to obtain a specimen from the lesions located in the left liver lobe, close to big vessels or in obese patients which are more difficult to obtain by other techniques.

Introduction

Recent developments in endoscopic ultrasound (EUS) have proven the effectiveness of endoscopic methods for performing liver biopsies, but there is still scarce and conflicting evidence on the comparison between EUS and percutaneous (PC)-guided liver biopsy (LB).

Aims & Methods

The aim of this study was to compare the routine method and analysis of PC-LB samples against the newly introduced EUS-LB in a series of patients with parenchymal liver lesions in a tertiary hospital between 2022-2024. EUS-LB was performed with a 19-gauge core biopsy needle (Acquire, Boston Scientific) via one pass/three actuation, wet suction technique in Propofol sedation. These samples were analyzed by a dedicated liver pathologist. PC-LB procedures were performed using a 16-gauge Menghini needle via one pass without sedation. Samples from the PC-LB group were analyzed by a non-dedicated liver pathologist. The primary outcome was diagnostic adequacy rate. The secondary outcomes were sample adequacy (assessed based on total specimen length (TSL), number of complete portal tracts (CPTs)), and adverse events. Data were retrospectively assessed by reviewing the hospital information system data.

Results

The study included 56 patients, 35 in the PC-LB group and 21 in the EUS-LB group. The median age of the patients at the time of liver biopsy was 52 years, 55% were female. Predominant diagnoses were nonalcoholic fatty liver disease (25%), primary biliary cholangitis (18%) and autoimmune hepatitis (18%). The rate of establishing histological diagnosis was significantly higher in the EUS-LB group (100% vs. 77%; p=0.019). Adequate biopsy rate (according to European Association for the Study of Liver Disease criteria) and optimal biopsy rate (according to American Association for the Study of Liver Diseases criteria) were 100% and 90.5% in the EUS-LB group vs. 68.6% and 40% in the PC-LB group, crossing the significance threshold (p=0.004 and p=0.0002, respectively). The median number of CPTs was significantly greater in the EUS-LB group, with a median of 35 CPTs (IQR 22-47) compared to 11 CPTs (IQR 8-14) in the PC-LB group (p<<0.05). Among all participants in this study, patients whose histological diagnosis was not established had a lower median number of CPTs, with 10 (5-18), compared to 14 (10-29) for those who were diagnosed. However, this difference was not statistically significant (p=0.11). Both methods had similar safety profiles regarding post-procedural bleeding, which was clinically non-significant (one patient in each group). Additionally, fewer patients in the EUS-LB group required postprocedural analgesics compared to the PC-LB group (5% vs. 26%; p=0.07).

Conclusion

EUS-LB can reliably provide samples suitable for a histopathologic diagnosis in patients with parenchymal liver disease. In our setting EUS-LB proved to be superior to PC-LB in terms of diagnostic yield, tissue adequacy, and occurrence of minor adverse events, respecting the fact that EUS-LB samples were analyzed by a dedicated pathologist. As such, the method was easily incorporated into the workflow of our endoscopy unit.

Introduction

Endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for hepatic solid lesions has emerged as a safe technique to obtain an adequate liver tissue for diagnosis of parenchymal liver disease. However, the optimal FNB techniques have not been evaluated. Out study aimed to compare the diagnostic yield and specimen adequacy for EUS-FNB in hepatic solid lesions using different FNB techniques.

Aims & Methods

This is a single center retrospective study of EUS-FNB for hepatic solid lesions between Mar. 2015 and Jun. 2022. Each one needle pass of suction and slow-pull suction was applied for the same hepatic lesions and the sequence was randomly assigned. The primary outcomes were diagnostic yield to attain a histological diagnosis and rate of adequate specimen acquisition.

Results

A total of 119 patients (40 female, median age 70 years) underwent EUS-FNB for hepatic solid lesions. The mean size of hepatic solid lesion was 34.9+27.3 mm (range 7-150). Solid live lesions were located at S1 in 5 (4.2%), S2/3 in 97 (81.5%), S4 in 13 (10.9%), and S5/6/7/8 in 4 (3.3%). Needle puncture was approached at esophagus in 5 (4.2%), stomach in 108 (90.8%), and duodenum in 6 (5.0%). The use of needle was 20G ProCore in 44 (37.0%) and 22G in 75 (63.0%). The final diagnosis of solid liver lesions was benign in 3 (2.5%) and malignancy in 116 (97.5%) including cholangiocarcinoma (49, 41.2%), metastasis (63, 52.9%), hepatocellular carcinoma (2, 1.7%), and lymphoma (2, 1.7%). The overall diagnostic yield to obtain a tissue diagnosis was 90.8%. There was statistically no difference in diagnostic accuracy between suction and slow-pull suction (79.8% vs. 84.9%, P=0.308). Slow-pull suction obtained more adequate specimen comparing to suction (95.0% vs. 87.4%, P=0.040).

Table 1. Comparison of specimen adequacy and diagnostic performances according to EUS-FNB techniques

Conclusion

The use of slow-pull suction EUS-FNB demonstrated improved specimen adequacy compared with suction technique with no difference in diagnostic accuracy.

References

Madhok, I. K., et al. (2022). "Endoscopic Ultrasound-Guided Liver Biopsy." Clin Liver Dis 26(1): 127-138.
Gheorghiu, M., et al. (2022). "Endoscopic Ultrasound-Guided Fine-Needle Biopsy versus Fine-Needle Aspiration in the Diagnosis of Focal Liver Lesions: Prospective Head-to-Head Comparison." Diagnostics (Basel) 12(9).