Effect of Introducer Length on the Rate of Radial Artery Occlusion During Endovascular Coronary Procedures: а Pilot Randomized Clinical Trial
Phase: NA
Conditions: Coronary Artery Disease
Sponsor: Tomsk National Research Medical Center of the Russian Academy of Sciences

Tyumen Cardiology Research Center, Tomsk National Research Medical Center, Russian 
Academy of Science, Tomsk, Russia 
 
 
 
 
 
 
 
 
 
Effect of introducer length on the rate of radial artery occlusion 
during endovascular coronary procedures: а pilot randomized 
clinical trial (146) 
Study Protocol 
 
 
 
 
 
 
 
 
 
 
 
 
 
02/11/2019 

Annually, the number of endovascular diagnostic and therapeutic procedures, such 
as coronary angiography (CAG) and percutaneous coronary intervention (PCI), has 
increased in our country. 
Concurrently, the rate of radial artery access (RAA) has increased. According to the 
2016 data, in the Russian Federation more than 75% of CAG and more than 74% of 
PCI were performed using RAA . RAA was first used for endovascular intervention 
in 1989. The method has become widespread in clinical practice, as it has several 
advantages. Compared to the femoral, RAA allows the number of puncture site 
complications to be reduced significantly . Due to the radial artery surface location, 
there is possibility of effective hemostasis, even with anticoagulants and inhibitors 
of glycoprotein IIb / IIIa platelet receptors . A very low rate of hemorrhagic 
complications (<1/1000) is determined in patients after RAA. In accordance with 
European Guidelines on myocardial revascularization, use of RAA is recommended 
in all cases of CAG and PCI (recommendation class I, level of evidence: A). 
Despite all advantages, radial artery occlusion (RAO) is determined in patients in 1-
10% of cases after transradial puncture.  RAO often has asymptomatic clinical 
course. However, the presence of RAO does not allow using of transradial artery 
access technique for subsequent interventions. Among the main mechanisms of 
RAO development, endothelial damage is distinguished, as well as decrease or 
complete stop of blood flow through the artery after introducer placement. This leads 
to thrombosis and is a predisposing factor for RAO development. Considering the 
above-mentioned mechanisms, it might be assumed that the use of increased length 
introducer will exclude the possibility of radial artery endothelial damage during 
endovascular procedures and replacement of catheters and thereby reduce RAO 
imcidence.  
          Planned work is a prospective pilot simple blind randomized study 
Inclusion criterion: 
 Signed informed consent form; 
 Age ≥ 18 years; 

 RAA technical capability 
 
The exclusion criteria. 
 RAA technical failure 
 
Patients will be randomized into two groups, depending on the length of introducer 
by generating random numbers on a remote site just before the procedure. The 
main study group will be consisted of patients who underwent transradial CAG and 
/ or PCI using a long introducer. The comparison group will be consisted of 
patients who underwent transradial endovascular procedures using a short 
introducer. In the main group of patients, 25 cm length with 6 Fr diameter and 
equipped with an internal metal needle with a 20 G plastic cannula and a 
hydrophilic conductor Radifocus Introducer II (Terumo, Japan) will be used. 
Moreover, in the comparison group of patients, 10 cm length, equipped with a 21 
G needle and steel conductor Radifocus Introducer II (Terumo, Japan) will be 
used. 
The primary endpoint of the study is RAO rate according to DU findings in the 
next closest hospital period (from 1 to 10 days). Secondary endpoints are: 
postpuncture hematomas, radial artery perforation/dissection, neuritis of the 
median nerve, puncture site bleeding, the rate of needle type conversion, puncture 
time, procedure from the introduction of the introducer to its extraction, time of 
fluoroscopy, total air kerma rate (mGy). 
Local hematomas are classified according to the following scale: I - diameter not 
more than 5 cm, II - not more than 10 cm, III - not more than 10 cm, but not higher 
than the elbow, IV - above the elbow, V - with the threat of hand ischemia. All 
endovascular interventions will be performed by 5 experienced endovascular 
surgeons. CAG and PCI procedures will be performed on an Allura Clarity 
angiographic complex (Phillips, Netherlands). After the introducer placement, 10 

mcg nitroglycerin solution will injected, as well as heparin 5,000 units after CAG, 
and heparin 7,500 units after PCI. 
Then, catheterization and contrasting of the left and right coronary arteries will be 
consecutively performed with 6 Fr diagnostic catheters, or, catheterization and 
contrasting will be performed using 6 Fr. guiding catheters during PCI. After 
removing the introducer, a standard pressure bandage will be applied for 6 hours. 
The control DU will be performed on an iE 33 apparatus (Phillips, Netherlands) no 
earlier than 24 hours after the procedure.