Trocar technique

The trocar technique is a common technique for surgical procedures and interventional placement of tubes and drainage where instruments, tubes or drains are advanced to the target location through a fixed cannula or hollow tube namely the trocar, which acts as a portal in the process.

History

Trocars have been used to drain fluids as ascites and edema for a long time during middle age and antiquity. Patents for trocars came up in the 19^th century.

Usage

The trocar technique has been traditionally used in the drainage of fluids and to place tubes and drains. It is also used to place optical devices for laparoscopy, arthroscopy and video-assisted thoracoscopy. It is suitable for large, superficial, easy accessible target locations ¹.

Advantages

Advantages of the trocar technique include ^1,2:

• fast and easy performance
• smaller risk of cross-infection/cross-contamination

Disadvantages

Disadvantages of the trocar technique include the following ¹: 

• potential for neurovascular and adjacent organ damage
• fewer options for adjustments in case of malposition
• limited choice of drainage catheters

Indication

Trocars are used in a wide range of surgical and interventional procedures ^1-5:

• laparoscopy/laparoscopic surgery
• arthroscopy
• video-assisted thoracoscopy (VATS)
• kyphoplasty/vertebroplasty
• drainage of fluid collections and abscesses
  • percutaneous transhepatic drainage
  • transgluteal drainage
  • transvaginal drainage
  • percutaneous drainage of renal and perinephric collections
  • percutaneous drainage of peritoneal and retroperitoneal fluid collections
• percutaneous cholecystotomy
• PEG placement
• image-guided thoracocentesis

Contraindications

Contraindications will depend on the trocar system and the puncture site and endangered organs and include:

• lack of safe pathway
• vascular access

Technique

Specific technical steps might vary with respect to the specific procedure, location, trocar system, type of anesthesia and possibly imaging technique for guidance ^1,2:

• sterilization and antiseptic skin preparation
• subcutaneous infiltration of local anesthetic if not performed under general anesthesia
• skin incision at the access location
• puncture and advancement of the trocar system into the desired cavity, organ or fluid collection
• removal of the trocar needle once the optimal target point has been reached
• insertion of the catheter/drain/instruments  through or over the trocar system
• removal of the trocar/stylet
• suture

Complications

Complications vary with the size of the trocar and the punctured cavity, organ or fluid collection ¹:

• failed access
• tube malposition
• hemorrhage
• infection
• viscus perforation / pneumoperitoneum
• adjacent organ injury
• neurovascular injury
• hernia formation

Practical points

• the approach should be planned thoroughly, before the puncture
• during CT-guided procedures, it is beneficial if the patient and trocar system fit into the gantry,  which can pose a problem in case of large girth or long drainage systems (e.g. 27cm)