ABSTRACT
BACKGROUND: Pancreatic cancer is often diagnosed at advanced stages, and early-stage diagnosis of pancreatic cancer is difficult because of nonspecific symptoms and lack of available biomarkers. METHODS: We performed comprehensive serum miRNA sequencing of 212 pancreatic cancer patient samples from 14 hospitals and 213 non-cancerous healthy control samples. We randomly classified the pancreatic cancer and control samples into two cohorts: a training cohort (N = 185) and a validation cohort (N = 240). We created ensemble models that combined automated machine learning with 100 highly expressed miRNAs and their combination with CA19-9 and validated the performance of the models in the independent validation cohort. RESULTS: The diagnostic model with the combination of the 100 highly expressed miRNAs and CA19-9 could discriminate pancreatic cancer from non-cancer healthy control with high accuracy (area under the curve (AUC), 0.99; sensitivity, 90%; specificity, 98%). We validated high diagnostic accuracy in an independent asymptomatic early-stage (stage 0-I) pancreatic cancer cohort (AUC:0.97; sensitivity, 67%; specificity, 98%). CONCLUSIONS: We demonstrate that the 100 highly expressed miRNAs and their combination with CA19-9 could be biomarkers for the specific and early detection of pancreatic cancer.
Subject(s)
Biomarkers, Tumor , Early Detection of Cancer , Machine Learning , MicroRNAs , Pancreatic Neoplasms , Humans , Pancreatic Neoplasms/blood , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/diagnosis , Early Detection of Cancer/methods , Female , Male , Middle Aged , MicroRNAs/blood , Biomarkers, Tumor/blood , Biomarkers, Tumor/genetics , Aged , CA-19-9 Antigen/blood , Case-Control Studies , AdultABSTRACT
BACKGROUND AND AIMS: The diagnostic performance of EUS-guided fine-needle aspiration/biopsy sampling (EUS-FNAB) for pancreatic ductal adenocarcinoma (PDAC) ≤10 mm in diameter is relatively low. Pancreatic juice cytology (PJC) has gained attention because of its high sensitivity for small PDACs. We aimed to clarify the diagnostic ability of EUS-FNAB and the salvage ability of PJC for PDAC ≤10 mm. METHODS: Data obtained from attempted EUS-FNAB for patients with EUS-confirmed pancreatic tumors ≤10 mm (excluding pancreatic metastases/malignant lymphomas) were retrospectively analyzed. Patients who experienced technical failure or had a negative EUS-FNAB result and had a strong likelihood of PDAC based on imaging characteristics underwent PJC. PDAC was diagnosed using resected histologic specimens, EUS-FNAB-positive tumor growth on the imaging examination, or additional EUS-FNAB-positive results after increase in tumor size. The primary endpoint was the diagnostic ability of EUS-FNAB for PDAC ≤10 mm. The salvage ability of PJC was also assessed. RESULTS: Overall, 86 of 271 patients with pancreatic tumors ≤10 mm who underwent attempted EUS-FNAB were diagnosed with PDAC. The technical success rate, sensitivity, specificity, and accuracy of EUS-FNAB for PDAC ≤10 mm were 80.8%, 82.3%, 94.9%, and 91.3%, respectively. Among the 35 PDAC patients who experienced technical failure or false-negative results of EUS-FNAB, 26 (74.3%) were correctly diagnosed using salvage PJC. CONCLUSIONS: The true success rate and sensitivity of EUS-FNAB for PDAC ≤10 mm were relatively low. When EUS-FNAB for a pancreatic lesion ≤10 mm strongly suspected to be PDAC is unsuccessful or yields a negative result, PJC is recommended. (Clinical trial registration number: UMIN000049965.).
Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Humans , Biopsy, Fine-Needle , Pancreatic Juice , Retrospective Studies , Pancreas/pathology , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/pathology , Carcinoma, Pancreatic Ductal/diagnosis , Carcinoma, Pancreatic Ductal/pathology , Endoscopic Ultrasound-Guided Fine Needle Aspiration/methodsABSTRACT
BACKGROUND AND OBJECTIVES: Currently, there are no reports on the learning curve of endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) using dedicated plastic stents. Therefore, we evaluated the outcomes of EUS-HGS using dedicated plastic stents at tertiary referral centers during the initial development phase of EUS-HGS. MATERIALS AND METHODS: Endoscopic retrograde cholangiopancreatography (ERCP) was strictly prioritized over EUS-HGS. Twenty-three consecutive patients treated using EUS-HGS with a 7-Fr dedicated plastic stent over 4 years beginning in 2018 were analyzed retrospectively. RESULTS: The most common primary disease was pancreatic cancer, and the most common reason for difficulty in ERCP was duodenal obstruction, followed by surgically altered anatomy. The overall technical success rate of EUS-HGS was 95.7% (22/23). One failed case was converted to EUS-guided choledochoduodenostomy. The clinical success rate was 90.9% (20/22). Adverse events (AEs) related to the procedure were observed in four (17.4%) patients, including mild biliary peritonitis in three (13.0%) and mild cholangitis in one (4.3%) patient; all patients received conservative therapy. No serious AEs, such as stent migration, bleeding, or gastrointestinal perforation, were observed. Recurrent biliary obstruction (RBO) was observed in eight (34.8%) patients. Of these, HGS stent replacement was performed in four patients, and other treatments were performed in the remaining four patients. Another four (17.4%) patients did not develop RBO but underwent periodic HGS stent replacement. CONCLUSIONS: EUS-HGS using a dedicated plastic stent was performed safely even in its initial phase of introduction. The approach using this stent can be useful in case of ERCP failure for biliary decompression because of the high feasibility and low risk of serious adverse events.
Subject(s)
Cholestasis , Learning Curve , Humans , Retrospective Studies , Cholestasis/etiology , Cholestasis/surgery , Endosonography/adverse effects , Cholangiopancreatography, Endoscopic Retrograde/adverse effects , Stents/adverse effects , Ultrasonography, Interventional/adverse effects , Plastics , Drainage/adverse effectsABSTRACT
BACKGROUND: There is no consensus on the necessity of endoscopic sphincterotomy (ES) to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) after endoscopic stenting in patients with malignant biliary obstruction. We investigated the incidence of PEP after endoscopic biliary stenting for malignant biliary obstruction with or without ES in a multicenter prospective cohort study. METHODS: We enrolled 807 patients who underwent endoscopic biliary stenting for malignant biliary obstruction with a native papilla at 36 hospitals between April 2017 and March 2018. The incidence of PEP in patients with or without ES was compared for subgroups based on stent type, placement method, and patient background. Univariate and multivariate analysis was performed to investigate the incidence of PEP in all stenting patients. RESULTS: Plastic and metal stents (MS) were inserted in 598 and 209 patients, respectively. The incidence of PEP in patients with or without ES was 7.9% and 7.4%, respectively among all stenting patients. The incidences of PEP with or without ES in plastic stent insertion patients, patients with MS insertion, stent insertions across the papilla, stent insertions across the papilla in patients without main pancreatic duct obstruction, and fully covered MS insertions across the papilla were compared. There was no overall significant difference in the incidence of PEP between those with or without ES. Multivariate logistic regression analysis for the incidence of PEP in all stenting patients revealed obstruction of the main pancreatic duct at the pancreatic head and epinephrine spraying on the papilla were significant factors; there was no significant difference in the incidence of PEP between patients with or without ES. CONCLUSION: Endoscopic sphincterotomy may not contribute to the prevention of PEP after endoscopic biliary stenting for malignant biliary obstruction, even in cases of insertion with a fully covered MS across the papilla.
Subject(s)
Cholestasis , Pancreatitis , Humans , Cholangiopancreatography, Endoscopic Retrograde/adverse effects , Cholangiopancreatography, Endoscopic Retrograde/methods , Sphincterotomy, Endoscopic/adverse effects , Sphincterotomy, Endoscopic/methods , Prospective Studies , Pancreatitis/etiology , Pancreatitis/prevention & control , Cholestasis/etiology , Cholestasis/prevention & control , Cholestasis/surgery , Stents/adverse effectsABSTRACT
A 65-year-old man had unresectable intrahepatic cholangiocarcinoma with a malignant biliary stricture. We used an endoscopic plastic stent to drain the bile. Despite receiving standard chemotherapy, the tumor eventually progressed and cancerous peritonitis developed. We had to exchange plastic stents frequently because of stent occlusion. We had a re-biopsy with EUS-FNA and tested for microsatellite instability, which came back as MSI-high. We administered pembrolizumab, which resulted in a significant reduction of tumor size. We were able to administer long-term chemotherapy without serious side effects by repeatedly exchanging plastic stents for stent occlusion. He has maintained partial response for more than 20 months after receiving pembrolizumab.
Subject(s)
Bile Duct Neoplasms , Cholangiocarcinoma , Aged , Antibodies, Monoclonal, Humanized , Bile Duct Neoplasms/diagnostic imaging , Bile Duct Neoplasms/drug therapy , Bile Duct Neoplasms/pathology , Bile Ducts, Intrahepatic/diagnostic imaging , Bile Ducts, Intrahepatic/pathology , Cholangiocarcinoma/diagnostic imaging , Cholangiocarcinoma/drug therapy , Cholangiocarcinoma/pathology , Humans , Male , Plastics/therapeutic use , StentsABSTRACT
We report the case of a 68-year-old man, who presented in emergency care with inarticulate speech. The patient was diagnosed with syndrome of inappropriate antidiuretic hormone (SIADH) associated with pancreatic cancer. All diagnostic criteria for SIADH were met, and cancer of the pancreatic tail was identified by computed tomography. Standard treatment for SIADH includes water restriction, oral NaCl, continuous intravenous infusion of 3% NaCl, and intravenous infusion of furosemide. However, these treatments have varying effectiveness and are difficult for both patients and medical staff. Furthermore, unless treatment of the underlying disease is successful, continued hospitalization is needed and the patient's quality of life is significantly impaired. In this case, hyponatremia improved with this standard treatment, but ascites and edema developed. We treated the patient with tolvaptan due to decreased cardiac function, and symptoms improved rapidly. Although surgery and chemotherapy could not be performed for pancreatic cancer, the SIADH was treated for 7 months without relapse. In summary, a case of SIADH complicated by pancreatic cancer was difficult to control with standard treatment, but responded rapidly to tolvaptan, and outpatient treatment could be continued for a long period. Tolvaptan is useful for the treatment of SIADH associated with cancer.
Subject(s)
Inappropriate ADH Syndrome , Pancreatic Neoplasms , Aged , Antidiuretic Hormone Receptor Antagonists/therapeutic use , Benzazepines/therapeutic use , Humans , Inappropriate ADH Syndrome/drug therapy , Inappropriate ADH Syndrome/etiology , Male , Pancreatic Neoplasms/complications , Pancreatic Neoplasms/drug therapy , Quality of Life , Tolvaptan , VasopressinsABSTRACT
A 57-year-old male patient with unresectable pancreatic head cancer was treated with chemotherapy, 5 courses of gemcitabine plus nab paclitaxel therapy, and 9 courses of gemcitabine monotherapy. After 12 months of treatment, he was admitted to our hospital with headache and dyspnea. He was diagnosed with gemcitabine-induced thrombotic microangiopathy (TMA) due to acute kidney dysfunction, hemolytic anemia, and thrombocytopenia. Gemcitabine was discontinued, and symptoms were improved without using hemodialysis and plasma exchange. After his renal function recovered, we started S-1 chemotherapy. Eighteen months later, the patient was alive. Looking back, we realized that fragment red blood cells appeared in complete blood count and serum LDH elevated at 5 months prior to admission, serum creatinine level increased slowly at 4 months prior to admission, and blood pressure elevated significantly at 2 months prior to admission. Therefore, physicians must be aware of TMA as a possible adverse event to gemcitabine. As in this case, hemolytic findings and hypertension in patients treated with gemcitabine may help early detection of TMA.
Subject(s)
Pancreatic Neoplasms , Thrombotic Microangiopathies , Deoxycytidine/analogs & derivatives , Humans , Male , Pancreatic Neoplasms/drug therapy , Renal Dialysis , Thrombotic Microangiopathies/chemically induced , Thrombotic Microangiopathies/diagnosis , Thrombotic Microangiopathies/drug therapy , GemcitabineABSTRACT
BACKGROUND AND AIMS: Histologic diagnosis of autoimmune pancreatitis (AIP) using EUS-guided FNA (EUS-FNA) is difficult. To address this issue, new fine-needle biopsy (FNB) needles were recently developed. Here, we prospectively evaluated 2 newly designed EUS-FNB needles for histologic evaluation in patients with type 1 AIP. METHODS: This was a prospective, randomized, multicenter trial comparing biopsy specimens obtained with a 22-gauge Franseen needle or a 20-gauge forward-bevel needle in patients with suspected type 1 AIP. AIP was diagnosed according to international consensus diagnostic criteria. The primary endpoint was the sensitivity of EUS-FNB needles, and secondary endpoints were the amount of specimen obtained, histology of the pancreas based on evaluation of lymphoplasmacytic sclerosing pancreatitis (LPSP), and contribution of histologic findings to the diagnosis of AIP. RESULTS: One hundred ten patients were randomly assigned to the Franseen group (22-gauge Franseen needle) or the forward-bevel group (20-gauge forward-bevel needle). EUS-FNB sampling was successful in all patients. Nine patients were excluded because of diagnoses other than AIP. Compared with the forward-bevel needle, the Franseen needle obtained a significantly greater number of high-power fields. Of 101 patients, 39 patients (78%) in the Franseen group and 23 patients (45%) in the Forward-bevel group were diagnosed with level 1 or 2 LPSP (P = .001). Thirty-six patients could not be diagnosed with type 1 AIP without EUS-FNB specimen results. CONCLUSIONS: The 22-gauge Franseen needle should be routinely used for histologic diagnosis of type 1 AIP. (Clinical trial registration number: UMIN 000027668.).
Subject(s)
Autoimmune Pancreatitis/pathology , Endoscopic Ultrasound-Guided Fine Needle Aspiration/instrumentation , Needles , Adult , Aged , Aged, 80 and over , Autoimmune Pancreatitis/diagnosis , Equipment Design , Female , Humans , Male , Middle Aged , Young AdultABSTRACT
OBJECTIVE: IgG4-related disease (IgG4-RD) is a systemic disease characterised by elevated serum IgG4 and IgG4-positive lymphoplasmacytic infiltration in the affected tissues. The pathogenic role of IgGs, including IgG4, in patients with IgG4-RD, however, is unknown. DESIGN: We examined the pathogenic activity of circulating IgGs in patients with IgG4-RD by injecting their IgGs into neonatal male Balb/c mice. Binding of patient IgGs to pancreatic tissue was also analysed in an ex vivo mouse organ culture model and in tissue samples from patients with autoimmune pancreatitis (AIP). RESULTS: Subcutaneous injection of patient IgG, but not control IgG, resulted in pancreatic and salivary gland injuries. Pancreatic injury was also induced by injecting patient IgG1 or IgG4, with more destructive changes induced by IgG1 than by IgG4. The potent pathogenic activity of patient IgG1 was significantly inhibited by simultaneous injection of patient IgG4. Binding of patient IgG, especially IgG1 and IgG4, to pancreatic tissue was confirmed in both the mouse model and AIP tissue samples. CONCLUSIONS: IgG1 and IgG4 from patients with IgG4-RD have pathogenic activities through binding affected tissues in neonatal mice.
Subject(s)
Autoimmune Diseases , Immunoglobulin G , Pancreas , Pancreatitis , Salivary Glands , Animals , Autoimmune Diseases/immunology , Autoimmune Diseases/pathology , Cell Culture Techniques , Disease Models, Animal , Humans , Immunoglobulin G/administration & dosage , Immunoglobulin G/blood , Male , Mice , Pancreas/immunology , Pancreas/pathology , Pancreatitis/immunology , Pancreatitis/pathology , Salivary Glands/immunology , Salivary Glands/pathologyABSTRACT
Although bleeding is the most common complication of peptic ulcer disease, bleeding from the proper hepatic artery is unusual. We report on the case of an 87-year-old woman who presented with melena. An upper endoscopy was performed for a bleeding duodenal ulcer; however, the bleeding could not be controlled. A careful assessment using contrast-enhanced computed tomography (CT) demonstrated that the bleeding source was the proper hepatic artery. Transcatheter arterial embolization of the proper hepatic artery was successfully performed. This case highlights the importance of careful assessment using contrast-enhanced CT to identify the source of bleeding. Endovascular treatment is the first choice of treatment for patients with bleeding from large arteries.
ABSTRACT
Background/Aims: High-grade pancreatic intraepithelial neoplasia and invasive pancreatic ductal adenocarcinoma ≤10 mm are targets for early detection of pancreatic cancer. However, their imaging characteristics are unknown. We aimed to identify endoscopic ultrasound findings for the detection of these lesions. Methods: Patients diagnosed with high-grade pancreatic intraepithelial neoplasia (n=29), pancreatic ductal adenocarcinoma ≤10 mm (n=11) (who underwent surgical resection), or benign main pancreatic duct stenosis (n=20) between January 2014 and January 2021 were retrospectively included. Six features differentiating these lesions were examined by endoscopic ultrasonography: main pancreatic duct stenosis, upstream main pancreatic duct dilation, hypoechoic areas surrounding the main pancreatic duct irregularities (mottled areas without demarcation or round areas with demarcation), branch duct dilation, prominent lobular segmentation, and atrophy. Interobserver agreement was assessed by two independent observers. Results: Hypoechoic areas surrounding the main pancreatic duct irregularities were observed more frequently in high-grade pancreatic intraepithelial neoplasia (82.8%) and pancreatic ductal adenocarcinoma ≤10 mm (90.9%) than in benign stenosis (15.0%) (p<0.001). High-grade pancreatic intraepithelial neoplasia exhibited mottled hypoechoic areas more frequently (79.3% vs 18.9%, p<0.001), and round hypoechoic areas less frequently (3.4% vs 72.7%, p<0.001), than pancreatic ductal adenocarcinoma ≤10 mm. The sensitivity and specificity of hypoechoic areas for differentiating high-grade pancreatic intraepithelial neoplasia, pancreatic ductal adenocarcinoma ≤10 mm, and benign stenosis were both 85.0%, with moderate interobserver agreement. Conclusions: The hypoechoic areas surrounding main pancreatic duct irregularities on endoscopic ultrasound may differentiate between high-grade pancreatic intraepithelial neoplasia, pancreatic ductal adenocarcinoma ≤10 mm, and benign stenosis (Trial Registration: UMIN Clinical Trials Registry (UMIN000044789).
Subject(s)
Carcinoma in Situ , Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Humans , Endosonography , Constriction, Pathologic/diagnostic imaging , Constriction, Pathologic/pathology , Retrospective Studies , Pancreatic Neoplasms/pathology , Carcinoma, Pancreatic Ductal/pathology , Pancreatic Ducts/diagnostic imaging , Pancreatic Ducts/pathology , Carcinoma in Situ/diagnostic imaging , Carcinoma in Situ/pathologyABSTRACT
OBJECTIVES: Although simultaneous occurrences of autoimmune pancreatitis (AIP) and cancer are occasionally observed, it remains largely unknown whether cancer and AIP occur independently or these disorders are interrelated. The aim of this study was to examine the relationship between AIP and cancer. METHODS: We conducted a multicenter, retrospective cohort study. One hundred and eight patients who met the Asian diagnostic criteria for AIP were included in the study. We calculated the proportion, standardized incidence ratio (SIR), relative risk, and time course of cancer development in patients with AIP. We also analyzed the clinicopathological characteristics of AIP patients with cancer in comparison with those without cancer. RESULTS: Of the 108 AIP patients, 18 cancers were found in 15 patients (13.9%) during the median follow-up period of 3.3 years. The SIR of cancer was 2.7 (95% confidence interval (CI) 1.4-3.9), which was stratified into the first year (6.1 (95% CI 2.3-9.9)) and subsequent years (1.5 (95% CI 0.3-2.8)) after AIP diagnosis. Relative risk of cancer among AIP patients at the time of AIP diagnosis was 4.9 (95% CI 1.7-14.9). In six of eight patients whose cancer lesions could be assessed before corticosteroid therapy for AIP, abundant IgG4-positive plasma cell infiltration was observed in the cancer stroma. These six patients experienced no AIP relapse after successful cancer treatment. CONCLUSIONS: Patients with AIP are at high risk of having various cancers. The highest risk for cancer in the first year after AIP diagnosis and absence of AIP relapse after successful treatment of the coexisting cancers suggest that AIP may develop as a paraneoplastic syndrome in some patients.
Subject(s)
Autoimmune Diseases/complications , Neoplasms/etiology , Pancreatitis/complications , Adult , Aged , Aged, 80 and over , Autoimmune Diseases/diagnosis , Autoimmune Diseases/immunology , Cohort Studies , Female , Follow-Up Studies , Humans , Immunoglobulin G/blood , Incidence , Male , Middle Aged , Neoplasms/diagnosis , Neoplasms/epidemiology , Pancreatitis/diagnosis , Pancreatitis/immunology , Retrospective Studies , Risk Assessment , Stomach Neoplasms/diagnosis , Stomach Neoplasms/epidemiology , Stomach Neoplasms/etiology , Time Factors , Young AdultABSTRACT
Pancreatic ductal adenocarcinoma (PDAC) arises from precursor lesions, such as pancreatic intra-epithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN). The prognosis of high-grade precancerous lesions, including high-grade PanIN and high-grade IPMN, without invasive carcinoma is good, despite the overall poor prognosis of PDAC. High-grade PanIN, as a lesion preceding invasive PDAC, is therefore a primary target for intervention. However, detection of localized high-grade PanIN is difficult when using standard radiological approaches. Therefore, most studies of high-grade PanIN have been conducted using specimens that harbor invasive PDAC. Recently, imaging characteristics of high-grade PanIN have been revealed. Obstruction of the pancreatic duct due to high-grade PanIN may induce a loss of acinar cells replaced by fibrosis and lobular parenchymal atrophy. These changes and additional inflammation around the branch pancreatic ducts (BPDs) result in main pancreatic duct (MPD) stenosis, dilation, retention cysts (BPD dilation), focal pancreatic parenchymal atrophy, and/or hypoechoic changes around the MPD. These indirect imaging findings have become important clues for localized, high-grade PanIN detection. To obtain pre-operative histopathological confirmation of suspected cases, serial pancreatic-juice aspiration cytologic examination is effective. In this review, we outline current knowledge on imaging characteristics of high-grade PanIN.
ABSTRACT
Background and aims: It is essential for endoscopists, technologists, and nurses to understand radiation protection. However, protective equipment usage is still low, and there is little awareness of radiation protection in practice. Methods: We conducted a questionnaire survey on radiation protection from January to February 2020. The participants were medical staff, including medical doctors, nurses, and radiological and endoscopy technician in endoscopy-fluoroscopy departments. The questionnaire included 14 multiple-choice questions divided among three parts: background, equipment, and knowledge. Results: We surveyed a total of 282 subjects from 26 institutions. There were 168 medical doctors (60%), 90 nurses (32%), and 24 technologists (9%). Although almost all staff members (99%) always wore a lead apron, only a few wore a thyroid collar (32%) and lead glasses (21%). The rate of wearing a radiation dosimeter was insufficient (69%), especially among doctors (52%). A few subjects knew the radiation exposure dose of each procedure (15%), and slightly over half had attended lectures on radiation protection (64%) and knew about the three principles of radiation protection (59%). Protection adherence did not differ by years of experience, knowledge of fluoroscopy, awareness of radiation exposure doses, or attendance at basic lectures on radiation protection. However, medical doctors who were aware of the radiation exposure dose of each procedure were significantly more likely to wear dosimeters than those who were not (p = 0.0008). Conclusion: Medical staff in endoscopy departments in Japan do not have enough radiation protection equipment or education.
Subject(s)
Cholestasis/surgery , Duodenal Obstruction/surgery , Pancreatic Neoplasms/surgery , Stents , Aged, 80 and over , Argon Plasma Coagulation/methods , Cholestasis/etiology , Duodenal Obstruction/etiology , Endoscopy, Digestive System , Humans , Male , Pancreatic Neoplasms/complications , ReoperationABSTRACT
BACKGROUND: Adequate needle size and tissue acquisition techniques for endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) need further elucidation. Moreover, the actual negative pressure and suction forces of FNA needles remain unknown. We evaluated the suction forces of 19-gauge, 22-gauge, and 25-gauge conventional FNA needles and side hole aspiration needles using conventional negative pressure and the slow pull technique. METHODS: Using a manometer, we determined the mean (SD) negative pressure and suction force for needle gauge, aspiration volume, and aspiration technique. We also evaluated the time to reach the maximum negative pressure. RESULTS: Suction force was comparatively higher in the 19-gauge needle when 50 ml of negative pressure was applied. Suction force using the slow pull method was very weak at 5% of pressure found with conventional methods. With the use of a 20-ml syringe, the time to reach the maximum negative pressure was 4 s in the 19-gauge needle, 11 s in the 22-gauge needle, and 80 s in the 25-gauge needle. CONCLUSIONS: Bench-top testing showed that suction force increases with a larger gauge needle and larger aspiration volume. The slow pull method produces a very weak suction force. The time to reach the maximum negative pressure was longest in the 25-gauge needle.