Endoscopic ultrasonography‐guided fine‐needle aspiration biopsy: A safe method for accurate diagnosis

Endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS FNAB) is a relatively new technique for obtaining specimens with excellent imaging power. The convex type of echoendoscope used with EUS FNAB provides images perpendicular to the endoscope, which differ from those of popular radial echoendoscopes and, hence, require different usage techniques. Color flow imaging is used to avoid the vessels in and around the mass during puncturing. EUS FNAB for submucosal tumors is sometimes difficult because the needle slips easily, and the gastrointestinal wall tends to be stretched when pushing the needle, which can be solved by making a dimple on the wall before puncturing. Lesions of the pancreas head, especially those at the uncus, and lymph nodes near the superior mesenteric artery are also difficult because of their distance from the endoscope and the resultant bending of the needle. Tissue sampling is more successful when the angle between the endoscope and the needle is kept at just less than 45 degrees, as this helps to transmit the hand force to the needle effectively. The complication rate of EUS FNAB is reportedly 1–2%, and so the technique is considered a safe modality, except for cystic lesions of the pancreas. Recent histological evidence is needed before applying medical therapies, such as chemoradiation and surgery, especially when imaging modalities alone cannot supply the evidence of malignancy; hence increasing importance of EUS FNAB is expected.     

Prospective evaluation of the optimal number of 25‐gauge needle passes for endoscopic ultrasound‐guided fine‐needle aspiration biopsy of solid pancreatic lesions in the absence of an onsite cytopathologist

Introduction: A prior study with 22‐gauge needles recommended more than seven needle passes for endoscopic ultrasound‐guided fine‐needle aspiration biopsy (EUS‐FNA) of solid pancreatic lesions (SPL) without onsite cytopathology for optimal acquisition of cytopathological diagnosis. The feasibility of this recommendation should be re‐evaluated considering the later development and popularity of 25‐gauge EUS‐FNA needles. We aimed to determine the optimal number of needle passes for cytopathological specimen acquisition with 25‐gauge needles for EUS‐FNA of SPL. Methods: A preliminary prospective study of 22 patients with an onsite cytopathology technician showed a sensitivity of 93.3% and a specificity of 100% with four needle passes that was not statistically different from five needle passes. Based on our preliminary study, we fixed the number of needle passes to four (Group A). As a control group, we carried out sampling in consecutive patients using 25‐gauge needles with an onsite cytopathologist (Group B). Sampling rate, diagnostic value and complications were evaluated. Results: We enrolled 20 patients in each group. Sampling rate was higher in Group B (20/20, 100%) than in Group A (19/20, 95%), but there was no statistical difference between them (P‐value = 0.31). In Group A, sensitivity, specificity and accuracy were 100% among 19. In Group B, sensitivity was 94.1%, specificity 100%, accuracy 95%. There were also no statistical differences between the groups. No complications were seen. Conclusion: Our study suggests that four needle passes using a 25‐gauge needle may be sufficient for EUS‐FNA of SPL where onsite cytology is not available.     

Identification and comparison of insulin pharmacokinetics injected with a new 4‐mm needle vs 6‐ and 8‐mm needles accounting for endogenous insulin and C‐peptide secretion kinetics in non‐diabetic adult males

Aims/Introduction

Many patients with diabetes now use 5‐, 6‐ or 8‐mm needles for insulin injection. However, it is unclear whether needle length, particularly for shorter needles, affects the pharmacokinetic properties of insulin.

Materials and Methods

This was a three‐way, randomized, cross‐over, single‐center study involving 12 healthy Japanese adult males (age 27.4 ± 4.14 years; weight 64.2 ± 5.2 kg; body fat percentage 18.2 ± 1.5%). Participants received a subcutaneous (abdomen) dose of insulin lispro (1.5 U for participants weighing 55 to <65.0 kg; 2.0 U for participants weighing 65.0 to <80.0 kg) delivered using a 32‐G × 4 mm (32G × 4), 31‐G × 8 mm (31G × 8) or 32‐G × 6 mm (32G × 6) needle with a 3–7‐day washout between doses. Pharmacokinetic parameters of exogenous insulin were identified using non‐linear least squares, where the total insulin concentration was fit to the measured plasma insulin concentration using an overall combined model that accounted for C‐peptide/insulin secretion in addition to the injected dose.

Results

Maximum concentration and area under the curve for 0 to infinity min for insulin were bioequivalent for the 32G × 4 needle relative to the 32G × 6 and the 31G × 8 needles. The time to the maximum insulin concentration was bioequivalent for the 32G × 4 needle relative to the 32G × 6 needle, but not the 31G × 8 needle.

Conclusions

The use of 4‐mm needles is unlikely to change the pharmacokinetic properties of insulin when injected subcutaneously in adults. This trial was registered with UMIN‐CTR (no. UMIN000004469).     

Factors affecting the diagnostic accuracy of endoscopic ultrasonography‐guided fine‐needle aspiration (EUS‐FNA) for upper gastrointestinal submucosal or extraluminal solid mass lesions

Aim: A number of potential variables are associated with the diagnostic accuracy of endoscopic ultrasonography‐guided fine‐needle aspiration (EUS‐FNA). The aim of this study was to evaluate factors affecting the diagnostic accuracy of EUS‐FNA for upper gastrointestinal submucosal or extraluminal solid lesions. Methods: Patients with such lesions who underwent EUS‐FNA between January 2009 and December 2010 were studied retrospectively. Needles of 22, 25 and 19 gauge were used. The associations between the EUS‐FNA results and factors such as mass location, mass size, needle size, number of needle passes, combined histologic‐cytologic analysis and final diagnosis were analyzed. Results: A total of 170 EUS‐FNA procedures were performed in 158 patients with upper gastrointestinal submucosal or extraluminal solid lesions. The overall accuracy of EUS‐FNA was 86.5% (147/170). The diagnostic accuracy with three or more needle passes was higher than with less than 3.0 needle passes (90.0%, 108/120 vs 78.0%, 39/50; P < 0.05). Mass location, mass size, and final diagnosis were not associated with EUS‐FNA accuracy. Combined cytologic‐histologic analysis had significantly higher diagnostic accuracy than either cytologic or histologic analysis alone (P < 0.001). In a subgroup of 90 patients, both 22 and 25 gauge needles were used for EUS‐FNA. The overall diagnostic accuracy was similar for 25 gauge needles and 22 gauge needles (80.0% vs 78.9% P = 1.000) in this subgroup. Conclusion: Overall, 25 and 22 gauge needles have a similar diagnostic accuracy. Our results suggest that 3.0 or more needle passes and combined cytologic‐histologic analysis enhance the diagnostic accuracy of EUS‐FNA.     

Role of endoscopic ultrasound‐guided fine‐needle aspiration with flow cytometry to diagnose lymphoma: A single center experience

Background and Aim: The use of endoscopic ultrasound‐guided fine‐needle aspiration (EUS?FNA) ± flow cytometry (FC) for the diagnosis of suspected lymphoma remains controversial. We report our experience and diagnostic yield for EUS ± FC for suspected lymphoma. Methods: Databases were queried for those who underwent EUS?FNA ± FC for suspected lymphoma. Hospital charts were reviewed to confirm the final cytological diagnosis, follow up and FC results if obtained. The final diagnosis was confirmed by the results of EUS?FNA ± FC, other biopsy and/or follow up. Results: In total, 54 patients underwent EUS?FNA of 72 lesions. The final diagnosis of lymphoma was made in 38 of the 54 (70%) patients, and 33 of the 54 (61%) patients relied on EUS?FNA. Cytopathology in 41 patients using EUS?FNA + FC showed lymphoma in 24 patients, atypical lymphoid cells in six and reactive lymph node in 11. In 9 of the 24 with lymphoma by EUS + FC, the diagnosis was confirmed by another diagnostic modality, like surgery, bone marrow biopsy and computed tomography‐guided biopsy. Of the six with atypical lymphoid cells, additional diagnostic methods confirmed lymphoma in three. The remaining 13 of the 54 patients underwent EUS?FNA without FC due to insufficient sample (n = 5) or operator choice (n = 8). Cytopathology in these 13 patients without FC showed lymphoma (9), atypical lymphoid cells (3) and reactive node (1). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of EUS?FNA for lymphoma in all 54 patients ranged from 80% to 87%, 92% to 93%, 97%, 60% to 75% and 83% to 89%, respectively. Conclusions: EUS?FNA is sensitive and specific for the diagnosis of suspected lymphoma. Confirmatory or further testing should be performed when EUS?FNA with or without FC is indeterminate and or non‐diagnostic.     

The anti‐lymphoma activity of antiviral therapy in HCV‐associated B‐cell non‐Hodgkin lymphomas: a meta‐analysis

Many epidemiological studies provide solid evidence for an association of chronic hepatitis C virus (HCV) infection with B‐cell non‐Hodgkin's lymphoma (B‐NHL). However, the most convincing evidence for a causal relationship between HCV infection and lymphoma development is the observation of B‐NHL regression after HCV eradication by antiviral therapy (AVT). We conducted a literature search to identify studies that included patients with HCV‐associated B‐NHL (HCV‐NHL) who received AVT, with the intention to treat lymphoma and viral disease at the same time. The primary end point was the correlation of sustained virological response (SVR) under AVT with lymphoma response. Secondary end points were overall lymphoma response rates and HCV‐NHL response in correlation with lymphoma subtypes. We included 20 studies that evaluated the efficacy of AVT in HCV‐NHL (n = 254 patients). Overall lymphoma response rate through AVT was 73% [95%>confidence interval, (CI) 67–78%]. Throughout studies there was a strong association between SVR and lymphoma response (83% response rate, 95%>CI, 76–88%) compared to a failure in achieving SVR (53% response rate, 95%>CI, 39–67%, P = 0.0002). There was a trend towards favourable response for AVT in HCV‐associated marginal zone lymphomas (response rate 81%, 95%>CI, 74–87%) compared to nonmarginal zone origin (response rate 71%, 95%>CI, 61–79%, P = 0.07). In conclusion, in the current meta‐analysis, the overall response rate of HCV‐NHL under AVT justifies the recommendation for AVT as first‐line treatment in patients who do not need immediate conventional treatment. The strong correlation of SVR and lymphoma regression supports the hypothesis of a causal relationship of HCV and lymphomagenesis.