Intermittent Versus Continuous Suction Technique in the Diagnosis of Pancreatic Solid Lesions. A Pilot Study.
Phase: NA
Conditions: Pancreatic Cancer, Pancreatic Neoplasms
Sponsor: Fundación de Investigación Biomédica - Hospital Universitario de La Princesa

INTERMITTENT VERSUS CONTINUOUS SUCTION TECHNIQUE IN THE DIAGNOSIS OF 
PANCREATIC SOLID LESIONS. A PILOT STUDY 
 
STUDY PROTOCOL 03/02/2019 
NCT03829748 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
PRINCIPAL INVESTIGATOR 
Dra. Raquel Herranz Pérez  
 
SUB-INVESTIGATORS 
 Dr. Felipe de la Morena López  
Dr. Cecilio Santander Vaquero 
 
Gastroenterology Department, Endoscopy Unit 
Hospital Universitario de la Princesa 
Madrid, Spain 
 

 
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1. INTRODUCTION: 
Solid lesions of the pancreas can be neoplastic or non neoplastic and it is important to 
accurately differentiate between them because of the poor prognosis related to 
pancreatic neoplasm. There are many types of solid pancreatic lesions: pancreatic 
adenocarcinoma, neuroendocrine tumor, lymphoma, solid pseudopapillary neoplasm 
and pancreatic metastasis.  
There are several diagnostic methods for the study of pancreatic solid lesions. The 
different imaging test allow detection and characterization of those lesions, but most 
times an anatomopathological diagnosis is needed before stablishing the most 
appropriate treatment.  
Endoscopic Ultrasound guided fine needle aspiration (EUS-FNA) is the diagnostic 
method of choice for the diagnosis of these lesions as it detects small lesions that 
sometimes cannot be found in radiological imaging test, evaluates vascular invasion and 
the presence of liver metastasis, and allows pancreatic puncture for a cytological 
diagnosis. EUS-FNA is the safest technique for pancreatic puncture and the least related 
to needle track seeding.  
In order to gather as much material as possible different techniques have been 
proposed:  
- Fanning technique and multiple pass technique: to guide the needle into different 
regions of the target lesions with or without removing the needle out of the lesion 
depending on wether the lesion is hard or soft.  
- Use of stylet: there are no data clearly demonstrating that the use of suction increases 
the yield of EUS-FNA. Some authors do slow withdrawal of the stylet. 
- Size of the needle: 19 gauge, 22 gauge, 25 gauge, depending on the localization, size 
and vascularization. There is increasing evidence that smaller needles offer at least 
similar results in diagnostic yield compared to larger needles and are also easier to 
manipulate. 
- Use of suction: there is conflicting evidence in this point. Several studies have 
evaluated the use of high volume aspiration vs low volume aspiration, continous 
aspiration vs no aspiration and suction with empty syringe vs water-filled syringe but 
none is clearly better than other.  
 

 
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2. HIPOTESIS:  
  Intermittent suction improves the diagnostic yield of pancreatic lesions compared to 
standard (continuous) suction. Up to our knowledge this method has not been yet 
evaluated. 
 
3. STUDY DESIGN: 
  Interventional study with diagnostic purpose, longitudinal, prospective, unicentric, 
blinded for participant and anatomopathologist, in patients with solid pancreatic lesions 
with indication of cytological sampling by Endoscopic Ultrasound refered to the 
Endoscopy Unit of Hospital Universitario de la Princesa from January 2019 to December 
2019.  
  Following clinical practice, an endoscopic ultrasound fine-needle aspiration (EUS-FNA) 
with a 25 gauge needle will be performed to each participant. The patients will be 
divided into two arms with a 1:1 ratio: 
a) Intermittent aspiration: Intervention arm. Endoscopic ultrasound will be 
done for the localization of the lesion and to localize the site of puncture. 
Prior to the puncture of the lesion the stylet is removed and a vacuum syringe 
is prepared with 10 cc of vacuum allowing the generation of continuous 
pressure inside and connected to the end of the needle. Once the lesion is 
punctured 15 movements in and out of the lesions will be made while the 
syringe is opened and closed on and off for a total of 3 times each pass. A 
total of 4 passes will be done in each lesion.  
b) Continuous/standard aspiration: Same procedure but once the lesion is 
punctured 15 movements in and out of the lesions will be made while the 
syringe remains opened.  
 Randomization will be done with the generation of a computer-generated random list 
using Epidat 4.0. software (SERGAS, Santiago de Compostela, Spain).  
  The endoscopic ultrasound will be done with an Olympus linear echoendoscope (GF-
UTC 260 Olympus®  Tokyo, Japan) under Propofol sedation by an Anesthesiologist.  
  Each pass will be sent to the pathologist separately to evaluate their individual 
characteristics and to determinate which one is diagnostic. A complete report will be 
done assessing: 

 
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a) Cellularity 
b) Hematic contamination 
c) Presence of cell block and possibility of doing immunohistochemistry  
 
4. OUTCOME MEASSURES:  
a. Primary outcome measure: Increase in diagnostic yield of pancreatic solid 
lesions 
b. Secondary outcomes: 
• Sample Celullarity: Number of malignant cluster of cells on 
each endoscopic pass 
• Blood contamination: Percentaje of blood contamination of 
the slides 
• Number of passes to reach a positive cytological diagnosis 
 
5. ELEGIBILITY CRITERIA: 
a) Inclusion Criteria: 
  - Pancreatic solid lesion 
  - Patients over 18 years old 
  - Suitable for endoscopy 
b) Exclusion Criteria: 
  - Contraindication for endoscopy 
  - Active anticoagulant therapy 
  -Thrombocytopenia or coagulopathy in the absence of its correction prior 
to the procedure 
  - Absence of informed consent 
  - Pregnancy 
  - Not accessible lesion for endoscopic ultrasound puncture 
 
 
 
 
 

 
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6. STATISTICAL ANALYSIS PLAN: 
  Data will be expressed as means and standard deviation for quantitative variables or 
frequencies and percentages for the categorical ones. Variables with non-normal 
distributions will be represented as means and percentage ranges. 
  Randomization will be done with a computer-generated random list in a 1: 1 ratio. The 
chi-square test will be used to compare qualitative variables. Correlation kappa values 
will be offered between both methods. In order to evaluate the differences in diagnostic 
yield, the sensitivity after the completion of each pass will be calculated by correlating 
the continuous values of confusion with the final cytology with the Spearman test. The 
number of optimal passes depending on the method will be calculated by maximizing 
that the following passes would not modify the additional diagnostic yield more than 
10% over the accumulated one. On the other hand, the cellularity and blood 
contamination graduated in its three levels will be contrasted between both methods 
with an analysis of McNemar. All the variables that could potentially modify the 
diagnostic yield of both methods will be compared with univariate and later multivariate 
analysis by means of logistic regression analysis with the STATA application (v13.0, 
StataCorp, College Station, Texas, USA). The protocol will be approved by the Ethical 
Committee of the Hospital Universitario de la Princesa before the start of the study.