Letters to the editor
the authors recommend using fine-needle biopsy (FNB) needles for sampling of nonpancreatic lesions. However, over half of the studies cited were abstracts, based on which conclusive recommendations cannot be made. In a recent meta-analysis comparing FNA and FNB needles that included 21 published studies (including abstracts from international meetings)2 involving 1617 patients, no significant differences were found in the rates of diagnostic adequacy, diagnostic accuracy, or histologic core tissue procurement between the 2 needle types for both pancreatic and nonpancreatic masses (Table 1). When the meta-analysis was repeated including only published full-text manuscripts (n Z 7), again no difference was observed between the FNA and FNB needles in diagnostic yield (94.4% vs 72.7%, pooled odds ratio (OR) .17, P Z .22 for all lesion types), diagnostic accuracy (89.0% vs 89.6%, OR .94, P Z .78 for all lesion types; 87.7% vs 91.4%, OR 1.48, P Z .33 for pancreatic masses), or histologic yield (74.7% vs 77.5%, OR 1.02, P Z .96 for all lesion types; 82.3% vs 79.3%, OR .95, P Z .91 for pancreatic masses). However, the FNB needle established the diagnosis with fewer number of passes (standardized mean difference –1.18, P ! .001 for all lesion types; standardized mean difference –1.03, P ! .001 for pancreatic masses). Therefore, the statement that the “FNB needle is highly effective for acquisition of core specimens” is incorrect. Second, the authors cited 1 abstract3 and 2 published manuscripts4,5 to support the use of the slow-pull/ capillary technique for EUS-FNB. However, none of these studies directly compared suction versus capillary techniques as the primary outcome measure. In a recent study that compared both techniques using 22G or 25G needles for sampling pancreatic masses, when the needles were evaluated individually, there was no significant difference for the procurement of histologic core tissue.6 Thus,
followed by literature update 20.6%, educational resources 11.1%, video atlas 8.5%, and others 0.8%. Smart devices appear to be an effective tool for disseminating EUS educational materials. Future endeavors to maximize their effectiveness will include measuring the impact of the app on learning EUS, incorporating resources for patients, and translation of the app into multiple languages. Ji Young Bang, MD, MPH Division of Gastroenterology-Hepatology Indiana University Indianapolis, Indiana, USA Robert Hawes, MD Center for Interventional Endoscopy Florida Hospital Orlando, Florida, USA Paul Focken, MD, PhD Department of Gastroenterology-Hepatology Academic Medical Center Amsterdam, The Netherlands Shyam Varadarajulu, MD Center for Interventional Endoscopy Florida Hospital Orlando, Florida, USA http://dx.doi.org/10.1016/j.gie.2014.12.020
EUS-guided tissue acquisition: things are not always what they seem To the Editor: We read with interest the recent review on EUS-guided tissue acquisition1 and make 2 specific remarks. First,
TABLE 1. Meta-analysis comparing the ProCore and standard FNA needles for tissue acquisition*
Outcome measure
ProCore (n)
FNA (n)
ProCore
FNA
Pooled estimate: mean (%)
Pooled estimate: mean (%)
Pooled RR
P value
Diagnostic adequacy All masses
742
745
82.7 (74.2-89.8)
79.3 (70.4-87.0)
1.06 (.97-1.16)
.221
Pancreatic masses
317
324
84.8 (70.4-95.0)
88.5 (80.1-94.9)
.98 (.85-1.12)
.721
All masses
421
474
84.9 (76.1-92.0)
79.3 (71.8-85.9)
1.06 (.99-1.14)
.083
Pancreatic masses
225
277
88.4 (82.4-93.3)
79.9 (73.6-85.5)
1.12 (.99-1.26)
.067
104
108
66.8 (49.7-81.9)
68.7 (54.5-81.3)
1.02 (.85-1.22)
.864
66
70
75.4 (60.2-87.8)
75.2 (63.2-85.5)
1.03 (.84-1.26)
.756
209
209
d
d
SMD –.90 (–1.80 to .005)
.051
Histology All masses Pancreatic masses Mean no. of passes for diagnosis: all masses
Values in parentheses are 95% confidence intervals. RR, relative risk; SMD, standardized mean difference. *Both published manuscripts and abstracts from major meetings have been included.
1300 GASTROINTESTINAL ENDOSCOPY Volume 81, No. 5 : 2015
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Letters to the editor
the utility of the capillary technique for yielding histologic core tissue has not been proven. Ji Young Bang, MD, MPH Division of Gastroenterology-Hepatology Indiana University, Indianapolis Indiana, USA Robert H. Hawes, MD Shyam Varadarajulu, MD Center for Interventional Endoscopy Florida Hospital, Orlando Florida, USA
REFERENCES 1. Wani S, Muthusamy VR, Komanduri S. EUS-guided tissue acquisition: an evidence-based approach (with videos). Gastrointest Endosc 2014;80:939-59. 2. Bang JY, Hasan M, Hawes R, et al. EUS-guided tissue acquisition: metaanalysis comparing the ProCore and standard FNA needles [abstract]. Gastrointest Endosc 2014;79:AB427. 3. Aadam A, Amick A, Shah J, et al. A multicenter prospective randomized controlled cross-over trial comparing endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) and fine needle biopsy (FNB) for pancreatic and non-pancreatic masses [abstract]. Gastrointest Endosc 2014;79:AB188-9. 4. Iwashita T, Nakai Y, Samarasena JB, et al. High single-pass diagnostic yield of a new 25-gauge core biopsy needle for EUS-guided FNA biopsy in solid pancreatic lesions. Gastrointest Endosc 2013;77:909-15. 5. Larghi A, Iglesias-Garcia J, Poley JW, et al. Feasibility and yield of a novel 22-gauge histology EUS needle in patients with pancreatic masses: a multicenter prospective cohort study. Surg Endosc 2013;27:3733-8. 6. Nakai Y, Isayama H, Chang KJ, et al. Slow pull versus suction in endoscopic ultrasound-guided fine-needle aspiration of pancreatic solid masses. Dig Dis Sci 2014;59:1578-85. http://dx.doi.org/10.1016/j.gie.2014.12.044
Making the GRADE To the Editor: The Technical Review on EUS-guided tissue acquisition provides an excellent summary on recent developments from an evidence-based approach.1 As clearly stated in the review, it was not intended to be a guideline, but the authors have incorporated the now-familiar GRADE system that is routinely used in guidelines. The use of the GRADE framework, though, can lead potential readers to focus on the final highlighted paragraph of each section, where the “bottom line” statement is provided. In some instances this approach may not fully reflect the complexity of the issue at hand. For example, the on-site cytopathology evaluation (OCE) of EUS-FNA specimens has been shown to increase the diagnostic yield in several studies of lower methodologic quality, but the one higher-quality study did not show a benefit of OCE. These controversies and the conflicting evidence on the role of OCE are nicely outlined throughout the text of the respective sections and in www.giejournal.org
Table 7 of the review; yet, in the final highlighted paragraph in a straightforward fashion is stated that “OCE does not impact diagnostic yield.” with “.the quality of evidence for this recommendation is moderate, and the strength of recommendation is strong.” Considering the conflicting evidence on the subject and the lack of sustained support from multiple high-quality studies, it seems reasonable to reconsider the strength of the recommendation according to the GRADE framework as “weak recommendation, moderate quality evidence.” Furthermore, the authors correctly point out that fixed guidelines use strict methodology that is different from that of a technical review. As such, it seems reasonable to reserve the use of the GRADE system to formal guidelines. Peter V. Draganov, MD Division of Gastroenterology, Hepatology and Nutrition University of Florida Gainesville, Florida, USA
REFERENCE 1. Wani S, Muthusamy VR, Komanduri S. EUS-guided tissue acquisition: an evidence-based approach (with videos). Gastrointest Endosc 2014;80: 939-59. http://dx.doi.org/10.1016/j.gie.2015.01.011
Response: We appreciate the response to our technical review1 by Bang et al and Dr Draganov and the opportunity to reply to their remarks. Bang et al claim that the conclusion stating “the FNB needle is highly effective for acquisition of core specimens” is inaccurate given the inclusion of abstracts as evidence for the review. The current technical review was performed in 2 parts: (1) a systematic review of variables that affect outcomes of EUS-guided tissue acquisition and (2) provision of evidence-based recommendations regarding those variables that are applicable to the majority of patients. The quality of evidence and strength of recommendations have been assessed by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.2 This article was based on a sequential assessment of the quality and level of evidence (eg, high: randomized, controlled trials, low: case series) and is intended to be flexible, allowing physicians to tailor it as such to individual patient circumstances. That being said, we did use high-quality abstracts (ie, randomized, controlled trials only), which were presented at national meetings within the past 2 years. The use of high-level abstracts from randomized, controlled trials is appropriate and an accepted methodology when conducting a systematic review. Abstracts should not be omitted from consideration to avoid biased and potentially incorrect conclusions.3 Volume 81, No. 5 : 2015 GASTROINTESTINAL ENDOSCOPY 1301