Histoacryl Injection Site for Gastric Varices
Inject Histoacryl into the varix while avoiding the most protruding part where intravariceal pressure is highest; the injection site should be determined based on the direction of blood flow within the varix. 1
Technical Approach to Injection Site Selection
Blood Flow-Directed Injection Strategy
The injection site must be selected based on the direction of blood flow inside the varix, as this determines optimal glue distribution and polymerization. 1
Specifically avoid injecting at the most protruding part of the varix, because intravariceal pressure is usually concentrated at this location, which increases the risk of premature glue extrusion, needle impaction, and systemic embolization. 1
The injection should be intravariceal (within the varix lumen itself), not paravariceal or submucosal. 1, 2, 3
Needle Positioning and Depth
Use a 5 mm or longer injection needle to ensure adequate penetration through the thick gastric wall and proper intravariceal placement. 1
A 21G or 22G needle is recommended to allow rapid injection of the viscous cyanoacrylate-lipiodol mixture. 1
The needle must reach the varix lumen completely; superficial injection into the gastric wall will fail to achieve hemostasis and may cause perforation. 1
Critical Technical Pitfalls
Needle Impaction Prevention
Withdraw the needle immediately after injection to prevent impaction into the polymerized tissue adhesive—this complication can be fatal if it leads to inability to control subsequent bleeding. 2
Push 1 mL of distilled water or saline through the catheter immediately after Histoacryl injection to ensure all adhesive material exits the catheter into the varix before needle withdrawal. 1
Volume and Mixture Considerations
Inject approximately 1 mL of the Histoacryl-lipiodol mixture (1:1 ratio) per session, repeating until hemostasis is achieved. 1
For large varices or active severe bleeding, the volume can be increased to 2 mL per injection, though this increases embolization risk. 1
Continue injections until all gastric varices become hard on palpation with the injection catheter. 2
Anatomic Context for GOV2 and IGV1
These fundal varices are typically large (F2 or F3) and located in the gastric fundus or posterior wall of the proximal body in 94.4% of cases. 3
The varices have high blood flow in the feeding channels, making them prone to massive bleeding but also making proper intravariceal injection technically challenging. 1
Unlike GOV1 varices that extend along the lesser curvature, GOV2 and IGV1 varices are isolated in the fundus and require direct treatment—they will not regress with esophageal variceal treatment alone. 4
Safety Precautions During the Procedure
Flush the working channel with olive oil in advance to prevent channel occlusion by spilled adhesive. 1
Medical personnel must wear goggles to prevent ocular injury from aerosolized cyanoacrylate. 1
Maintain awareness that systemic embolization, infection, fever, gastric perforation, gastric ulcer, and peritonitis are recognized complications, occurring in approximately 6.9% of cases. 1, 2