Wet- versus dry-suction techniques for EUS-FNA of solid lesions: A systematic review and meta-analysis

Abstract

The optimal sampling techniques for EUS-FNA remain unclear and have not been standardized. To improve diagnostic accuracy, suction techniques for EUS-FNA have been developed and are widely used among endoscopists. The aim of this study was to compare wet-suction and dry-suction EUS-FNA techniques for sampling solid lesions. We performed a comprehensive literature search of major databases (from inception to June 2020) to identify prospective studies comparing wet-suction EUS-FNA and dry-suction EUS-FNA. Specimen adequacy, sample contamination, and histologic accuracy were assessed by pooling data using a random-effects model expressed in terms of odds ratio (OR) and 95% confidence interval (CI). Six studies including a total of 418 patients (365 wet suction vs . 377 dry suction) were included in our final analysis. The study included a total of 535 lesions (332 pancreatic lesions and 203 nonpancreatic lesions). The pooled odds of sample adequacy was 3.18 (CI: 1.82–5.54, P = 0.001) comparing wet- and dry-suction cohorts. The pooled odds of blood contamination was 1.18 (CI: 0.75–1.86, P = 0.1). The pooled rate for blood contamination was 58.33% (CI: 53.65%–62.90%) in the wet-suction cohort and 54.60% (CI 49.90%– 59.24%) in the dry-suction cohort ( P = 0.256). The pooled odds of histological diagnosis was 3.68 (CI 0.82–16.42, P = 0.1). Very few adverse events were observed and did not have an impact on patient outcomes using either method. EUS-FNA using the wet-suction technique offers higher specimen quality through comparable rates of blood contamination and histological accuracy compared to dry-suction EUS-FNA.

Effect of wet-heparinized suction on the quality of mediastinal solid tumor specimens obtained by endoscopic ultrasound-guided fine-needle aspiration: a retrospective study from a single center

“…Blood contamination in paraffin sections can significantly affect the result of pathological diagnosis, and current studies on the effect of heparin use in puncture are controversial [ 6 , 29 ]. A recent meta-analysis demonstrated that heparin use had no significant effect on blood contamination in paraffin sections [ 8 ]. In this context, we found that there was a statistically significant difference in the blood contamination between the two groups in the first puncture, with less blood contamination in the Experimental group than in the Control group ( P < 0.05).…”

“…At present, multiple techniques have been developed to improve the quality of puncture specimens, such as negative micro-pressure, fanning puncture and wet tap [ 4 ], but the effect is unsatisfactory. Previous studies pointed out that wet-heparinized suction for biopsy of a peritoneal lesion could increase the sample volume and reduce blood contamination [ 5 – 8 ]. Due to the distinct difference between the histological characteristics of peritoneal and mediastinal masses [ 9 ], this technique is poorly investigated in studies on mediastinal masses, especially on mediastinal lymph node.…”

The Utility of Endoscopic-Ultrasonography-Guided Tissue Acquisition for Solid Pancreatic Lesions

“…There have been two meta-analyses of suction techniques. Ramai et al compared wet and dry suction, and wet suction has shown advantages in terms of specimen adequacy (pooled OR: 3.18, 95% CI: 1.82-5.54) [49]. Wang et al showed that the slow-pull technique was better than the standard method in terms of core tissue acquisition (pooled OR: 1.91, 95% CI: 1.11-3.26), blood contamination (pooled OR: 1.93, 95% CI: 1.29-2.87), and diagnostic accuracy (pooled OR: 1.60, 95% CI: 1.14-2.26) [50].…”

Methods to increase the diagnostic efficiency of endoscopic ultrasound-guided fine-needle aspiration for solid pancreatic lesions: An updated review

“…Suction is commonly used to obtain adequate samples, but it may damage cellular structures and contaminate the sample with blood, clouding cytologic interpretation[ 27 ]. Compared with dry suction, wet suction has better sample adequacy and higher diagnostic accuracy without increasing blood contamination[ 28 , 29 ].…”