Endoscopic ultrasonography-guided drainage of a pancreatic pseudocyst one week after formation.

Dear Editor,

Endoscopic ultrasound (EUS) is the endoscopy combined with ultrasound to obtain images of the gastrointestinal (GI) tract and adjacent structures.[1] EUS-guided pancreatic pseudocyst (PPC) drainage has become increasingly popular due to its benefits, which include minimal invasiveness, lower cost, and excellent results. Conventional EUS-guided drainage requires an observation period of more than a month, we report a case of EUS-guided drainage about one week after PPC formation.

A 47 year-old man was admitted to our hospital following an abdominal crush injury. Increased abdominal pain and swelling appeared after 6 days of conservative treatment. An abdominal computed tomography (CT) revealed a PPC in the body of the pancreas measuring 9 cm in diameter [Figure 1], which constricted the intestinal tract. EUS [Figure 2] revealed that the cyst wall had a thickness of approximately 1 cm, and a good adhesion between the cyst wall and stomach wall; no relative motion when the patient took a deep breath. In order to relieve the gastrointestinal obstruction and intolerable abdominal distention, we performed EUS-guided PPC drainage on the 7th day [Figure 3]. Strong adhesions were formed between the cyst and the gastric wall; furthermore, fluid leakage did not occur. Neither pancreatitis nor any other infectious process occurred. The amylase level of the drainage fluid was 44,220 U/L and the lipase level was 118,430 U/L. One day after drainage, the abdominal pain and swelling significantly decreased. Four days later, CT revealed that the PPC had decreased in size [Figure 4]. Five months later, the stent was removed. A recurrence did not occur during 12 months of follow-up.

Figure 1

CT reveals rupture of the pancreatic body and a large PPC with gastric compression. CT: Computed tomography; PPC: Pancreatic pseudocyst

Figure 2

EUS image of the PPC before drainage. EUS: Endoscopic ultrasound

Figure 3

Gastroscopy and EUS views during drainage

Figure 4

CT reveals significant reduction of the PPC following drainage

The formation of PPC as a complication of pancreatitis, operation, or trauma may lead to abdominal pain, gastric outlet obstruction, jaundice, pseudocyst infection, and even neighboring organ necrosis.[2] Therefore, medical intervention is necessary when conservative treatments fail. EUS-guided PPC drainage is safe, economical, and effective; it has become the first clinical choice instead of surgery.[3456] However, the appropriate timing for drainage is difficult to determine in the clinical setting.

Traditionally, a 6-week observation period is generally recommended prior to the drainage of a PPC, which is based on two points:

Spontaneous regression may occur; and

The PPC wall requires time to thicken.[57]

However, occasionally some PPCs will enlarge rapidly and cause painful compression of the surrounding structures, such as in our case. This situation requires immediate and effective intervention. When a 6-week observation of a PPC is not feasible, a preoperative diagnostic EUS is essential; it can measure the thickness of cyst wall and evaluate whether adhesions are present between the cyst and gastric wall. A successful emergency drainage can promptly alleviate pain.

This case demonstrates that the cutoff time of 6 weeks should be reevaluated. In our opinion, the size of PPC[589] and the thickness of the cyst wall should take precedence over the 6-week observation period. This clinical observation has some limitations. One case cannot determine the necessity for modification of the traditional 6 week cutoff and the case lack of long-term follow-up. Thus, further studies are needed.