//mmaneevese

mmaneevese

Percutaneous cholecystostomy may be performed using ultrasound, CT, or fluoroscopic guidance. Fluoroscopy and computed tomography generally have limited availability, increased expense, exposure to radiation, and perhaps the limiting factor, the need to transfer critically ill patients to the radiology suite. A 2010 study performed by Donkol et al. demonstrated success rates for CT (93%), US (46%), and fluoroscopy (62%). Though US had the lowest success rate, it remains the only option for those critically ill who cannot tolerate transportation outside the intensive care unit or an immediate cholecystectomy. Also, at most experienced centers that rate of procedural success with ultrasound guidance is far higher than 46%.

The patient is positioned supine with arm abducted to an arm board. Using a convex probe at frequency range 2.5–6 MHz, the gallbladder is evaluated for the best approach. Confirm liver anatomy is as expected [1211].

In the transhepatic approach, the catheter is to pass via the bare area of the liver in order to access the gallbladder. This may be done subcostally, thought the intercostal approach is preferred to minimize tube dislodgement and kinking. When using an intercostal approach, care must be taken to avoid puncturing the diaphragm, pleura or the intercostal neurovascular bundle as it passes inferior to the rib. The transhepatic approach decreases the risk of bile leaks and colon injury, which are more common in the transperitoneal approach [121219]. Higher rates of bleeding are associated with the transhepatic approach [13].

The transperitoneal approach is a direct puncture of the gallbladder, often used in patients who have coagulopathies, which preclude the transhepatic approach. The gallbladder must be distended and in close proximity to the abdominal wall [121219]. In the author’s opinion, the transhepatic, intercostal approach is the safest and preferred method.

Once a trajectory has been planned, the patient is then sterilely prepped and draped in a supine position with right arm abducted [11]. The entry site is anesthetized with 1–2% buffered lidocaine.

There are two techniques used for placement of the pigtail catheter into the gallbladder—the modified Seldinger technique, and the trocar technique.

The modified Seldinger technique consists of inserting a needle into the gallbladder under direct US guidance (Figure 1). The most common needle is an 18 G 10 cm hollow core needle, although smaller gauge needles can be used with 0.018 inch access systems. Aspiration of the needle should confirm bilious return. A 0.035 inch guidewire is then inserted through the needle into the gallbladder lumen. The wire should be seen looping in the gallbladder lumen with ultrasound. Use a scalpel to create a skin nick at the needle entry site and bluntly dilate this with a Kelly clamp or curved snap. The needle is removed and dilators of increasing diameters are advanced over the wire just into the gallbladder in order to dilate a tract large enough to accommodate a drain. The most common drain sizes are 8, 10 and 12 F, with larger sizes chosen for more viscous fluid. The catheter is advanced over the wire under ultrasound guidance. Once the tip enters the gallbladder, the catheter is unlocked from the inner stiffener and further advanced over the wire. The wire and stiffener are then removed, and pulling on the drain string forms the catheter. This is locked into place by various mechanisms, depending on catheter manufacturer. Straight drains should be avoided, as the pigtail mechanism will help to prevent tube malposition or withdrawal. The catheter should then be aspirated to ensure bilious return. The catheter course should also be imaged with ultrasound to confirm intraluminal location of all of the sideholes. The advantage to the Seldinger technique is the use of a small needle for initial access, reducing risk of damage to surrounding structures and bleeding if the initial attempt is not successful. The biggest disadvantage to this technique is that through the multiple exchanges there is mixing of infected bilious material from the gallbladder and blood from the transhepatic tract, potentially increasing the risk for sepsis. In the case of the transperitoneal approach, this technique would allow for spillage of bilious material into the peritoneum and increase the risk of peritonitis. Furthermore, this technique requires multiple steps from initial puncture to catheter placement, making it more time consuming than the trocar technique