Common bile duct cannulation in the left lateral position during ERCP.

Sir,

We read with interest the recent study by Park et al. on the efficacy and safety of the left lateral position for endoscopic retrograde cholangiopancreatography (ERCP).[1]

It is well known that ERCP is usually performed with the patient in a prone or supine position. In this manner, a better view of the biliary and pancreatic radiological anatomy is displayed during fluoroscopy. The common bile duct (CBD) is on the left whereas the main pancreatic duct (MPD) is on the right part of the screen [Figure 1]. However, when the patient is in the left lateral decubitus both ducts can overlap or even be in a reverse position (MPD left, CBD right), which can be confusing for biliary guide wire (GW) cannulation. The left lateral position is sometimes chosen in patients with respiratory problems or to allow an easier progress of the duodenoscope to the duodenum.

Figure 1

Pancreatic stent with radiological marker in the main pancreatic duct. Left, biliary and pancreatic ducts are apart when the patient is in the supine or prone position. Right, biliary and pancreatic ducts overlap in the left lateral position

As Park et al.[1] stated the rates of unintentional MPD cannulation and the acquisition of pancreatograms in the left lateral group were significantly greater than in ERCPs performed in the prone position.

We found an easier CBD cannulation when a plastic pancreatic stent (PS) with radiological marker is inserted when the GW enteres first in the MPD during CBD cannulation attempts in patients placed in the left lateral position. CBD cannulation is attempted with a sphincterotome loaded with a short GW controlled by the endoscopist. After unintentional GW passage into the MPD, a straight Advanix PS (Boston Scientific, Natick, Massachussets, USA) 5 F in diameter and 4 cm long without internal flaps is inserted. This PS has a proximal radiopaque marker that facilitates recognition of the pancreatic position. After PS placement new attempts are made with the same sphincterotome loaded with the GW over the PS to achieve CBD cannulation. PSs are left in place at the end of ERCP to prevent pancreatitis. Spontaneous PSs expulsion is expected due to lack of internal flaps.

We have been performing this approach for CBD cannulation for several years,[23] taking advantage of the GW unintentional passage to the MPD. This technique appears to be more useful in patients placed in the left lateral position due to the increased rates of unintended MPD cannulation, as Park et al.[1] showed in this paper.

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Conflicts of interest

There are no conflicts of interest.