Overview
Definition:
Endoscopic ultrasound (EUS)-guided drainage procedures involve using endoscopic ultrasound to precisely target and drain fluid collections, abscesses, or cysts in the abdomen and mediastinum, offering a minimally invasive alternative to traditional surgical or percutaneous approaches
this technique bridges interventional radiology, gastroenterology, and surgery by enabling targeted access and intervention through the gastrointestinal tract.
Epidemiology:
Pancreatic pseudocysts are the most common indication for EUS-guided drainage, occurring in 5-10% of patients with acute pancreatitis and up to 30% of chronic pancreatitis cases
Biliary obstruction due to malignant strictures is another significant indication, affecting a substantial number of patients with unresectable pancreatic cancer or cholangiocarcinoma
Abscesses in the peri-pancreatic region or other abdominal locations also represent a frequent indication for drainage.
Clinical Significance:
EUS-guided drainage offers a less invasive approach for managing complex fluid collections and obstructions, reducing hospital stays, pain, and the risk of major surgical complications
For surgical residents, understanding the indications, technical nuances, and potential complications is crucial for effective patient management, collaboration with gastroenterologists, and optimal surgical planning when these procedures fail or are not feasible.
Indications For Eus Drainage
Pancreatic Pseudocyst:
Symptomatic pancreatic pseudocysts (pain, gastric outlet obstruction, biliary obstruction, infection)
Size greater than 5 cm or persisting beyond 6 weeks
Infected pseudocysts.
Biliary Obstruction:
Malignant biliary obstruction where standard ERCP has failed or is not possible
Distal malignant biliary strictures with accessible segments beyond the obstruction
Symptomatic relief is the primary goal.
Abscess Drainage:
Intra-abdominal or peri-pancreatic abscesses amenable to EUS visualization and percutaneous/transgastric drainage
Infected necrosis requiring drainage.
Other Collections:
Mediastinal cysts (e.g., bronchogenic, esophageal duplication cysts)
Lymphoceles
Seromas in specific locations accessible via EUS.
Surgical Interface And Considerations
Patient Selection:
Close collaboration with surgeons is vital to select appropriate candidates
Factors influencing selection include the location and nature of the collection, patient comorbidities, prior surgical history, and the availability of surgical expertise for conversion if needed.
Alternative Surgical Approaches:
Open surgical cystojejunostomy or cystogastrostomy
Percutaneous drainage by interventional radiology
Laparoscopic drainage approaches
The choice depends on complexity, expertise, and institutional resources.
Role Of Surgeon:
The surgeon provides expertise on anatomy, potential complications (e.g., bowel perforation, bleeding), and manages cases where EUS drainage is unsuccessful or leads to complications requiring surgical intervention
Pre-operative surgical consultation is essential for complex cases.
Procedure Technique And Instruments
Diagnostic Eus:
Initial EUS assessment to characterize the fluid collection, determine its proximity to the GI tract, and identify intervening structures
Color Doppler is used to assess vascularity.
Access Needle:
A 19-gauge or 25-gauge aspiration needle is typically used for initial access into the collection
For drainage, a 6-French or 7-French needle-knife or a dedicated drainage catheter is employed.
Guidewire Placement:
After successful puncture, a 0.035-inch guidewire is advanced into the collection under EUS guidance
The tract is then typically dilated using a balloon dilator or a cautery device (e.g., needle-knife sphincterotome).
Drainage Catheter Placement:
Various catheters are available, including double-pigtail stents, L-bar stents, or lumen-apposing metal stents (LAMS)
LAMS are increasingly favored for their efficacy in maintaining patency and providing simultaneous drainage and apposition.
Imaging Guidance:
Real-time EUS imaging is critical throughout the procedure to guide needle and catheter placement, avoid injury to adjacent organs (e.g., major vessels, bowel loops), and confirm successful drainage.
Post Procedure Care And Complications
Immediate Post Procedure:
Observation for bleeding, perforation, or signs of infection
Pain management
NPO status initially, advancing diet as tolerated
Monitoring vital signs and abdominal examination.
Early Complications:
Hemorrhage (ranging from mild to arterial bleeding)
Perforation of adjacent organs (bowel, stomach, vessels)
Infection (sepsis, peritonitis)
Pancreatitis exacerbation.
Late Complications:
Re-accumulation of fluid
Stent migration or occlusion
Fistula formation
Stricture formation at the drainage site
Secondary infection.
Management Of Complications:
Management depends on the complication
Bleeding may require endoscopic hemostasis or surgical intervention
Perforation necessitates surgical repair
Infection requires antibiotics and drainage
Re-accumulation may require repeat drainage or surgical intervention.
Key Points
Exam Focus:
EUS-guided drainage is a multidisciplinary procedure
Indications, contraindications, and potential complications are high-yield for surgical exams
Understanding when to refer to gastroenterology/interventional radiology and when surgical intervention is necessary is critical.
Clinical Pearls:
Thorough pre-procedure assessment, including advanced imaging and surgeon consultation, is paramount
Meticulous technique is required to avoid vascular injury and perforation
LAMS offer superior lumen apposition and patency rates for larger collections.
Common Mistakes:
Inadequate characterization of the fluid collection
Puncturing major vessels or adjacent bowel loops
Incomplete drainage leading to re-accumulation
Failure to recognize and manage early complications promptly
Not involving surgical colleagues when indicated.