Endoscopic Ultrasound-Guided Transesophageal Drainage of a Mediastinal Pancreatic Pseudocyst

We read with great interest the recent article by Jonas et al. [1] which described the endoscopic ultrasound- (EUS-)guided drainage of a cystic metastasis in the mediastinum, and also the article by Mohl et al. [2] reporting their experience of endoscopic transhiatal drainage of a mediastinal pancreatic pseudocyst. Both articles reported interesting cases of EUS-guided or EUS-assisted drainage of mediastinal lesions. We recently managed a similar case, a patient with a large pancreatic pseudocyst that extended through the diaphragmatic hiatus inside the mediastinum, which was complicated by a left pleural effusion.

A 30-year-old man, with a known history of heavy alcohol consumption, was admitted in the Emergency Department complaining of intense epigastric pain, nausea, and vomiting. He was suspected to have acute pancreatitis. Computed tomography revealed a large (15 cm) pancreatic body pseudocyst that extended upward through the diaphragmatic hiatus into the posterior mediastinum, close to the descending aorta (Figure [1]). A large left pleural effusion with a high amylase content was also present, which persisted despite two drainage procedures and 1 month of conservative treatment.

Figure 1 Coronal reconstruction of contrast-enhanced computed tomographic images, showing a 15-cm pancreatic body pseudocyst that extended upward through the diaphragmatic hiatus (arrows) into the posterior mediastinum.

Because of the close proximity to the aorta and the absence of a clear bulge inside the stomach or esophagus, EUS-guided drainage of the mediastinal pancreatic pseudocyst was performed through the terminal esophagus using a large-channel linear ultrasound endoscope (Olympus GF-UC160T AL5; Olympus, Hamburg, Germany) and a one-step drainage system consisting of a diathermic catheter-guidewire assembly and a mounted 5-cm, 10-Fr stent (Giovannini Needle Wire; Wilson-Cook, Limerick, Ireland). The procedure was technically successful, with good visualization of the stent placement inside the mediastinal pancreatic pseudocyst (Figure [2]) and intermittent drainage of fluid inside the esophagus. After 24 hours, upper gastrointestinal endoscopy and computed tomography with coronal reconstruction of the images showed that the stent had rolled over, with the upper esophageal end now inside the stomach, in a good downward-facing position that allowed drainage of the mediastinal collection directly into the stomach (Figure [3]).

Figure 2 Endoscopic ultrasound-guided puncture of the mediastinal pancreatic pseudocyst was performed through the terminal esophagus, with good visualization of the stent placement inside the mediastinal pancreatic pseudocyst. The flow through the stent was recorded by power Doppler.

Figure 3 After 24 hours, upper gastrointestinal endoscopy showed that the stent had rolled over, with the upper esophageal end located inside the stomach, in a good downward position that allowed drainage of the mediastinal collection directly into the stomach.

The clinical course was favorable and after 1 month there was complete disappearance of both the mediastinal pancreatic pseudocyst and the left pleural collection. On computed tomographic scans, the stent was visualized with the upper end in the mediastinum in close contact with the descending aorta, without any fluid collections (Figure [4]). The stent was gently pulled inside the stomach and subsequently removed without any complications. The patient was then followed up for 3 months without any evidence of recurrence.

Figure 4 Control contrast-enhanced axial computed tomographic image after 30 days, showing the stent with its upper end in the mediastinum in close contact with the descending aorta, and no fluid collections.

EUS-guided drainage of symptomatic pancreatic pseudocysts is currently considered a good choice of management in expert centers, with low rates of morbidity and mortality reported in the literature [3]. EUS-guided drainage is strongly advocated by several experts, especially in the absence of a visible bulge inside the gastroduodenal tract or in patients with intervening collateral vessels [4]. However, there have been no randomized controlled trials to compare EUS-guided transmural drainage with open surgical drainage for the treatment of pancreatic pseudocysts. Although EUS-guided transgastric, transduodenal, and even transesophageal drainage procedures can be performed safely, their use should be limited for the present to expert centers with large caseloads and excellent experience.

The case presented clearly shows that EUS-guided transesophageal drainage is technically feasible, with minimal risks for the patient. However, we strongly suggest that direct guidance under real-time EUS visualization should be used in all interventional procedures in the mediastinum, in order to minimize the incidence of vascular complications caused by the close proximity to the aorta and the heart.

Competing interests: None

References

• 1 Jonas E, Josephson T. Endoscopic ultrasound-guided drainage of a cystic metastasis in the mediastinum that caused tracheal obstruction.  Endoscopy. 2005;  37 272-274
• 2 Mohl W, Moser C, Kramman B. et al . Endoscopic transhiatal drainage of a mediastinal pancreatic pseudocyst.  Endoscopy. 2004;  36 467
• 3 Brugge W R. Approaches to the drainage of pancreatic pseudocysts.  Curr Opin Gastroenterol. 2004;  20 488-492
• 4 Sriram P VJ, Kaffes A J, Rao G V, Reddy D N. Endoscopic ultrasound-guided drainage of pancreatic pseudocysts complicated by portal hypertension or by intervening vessels.  Endoscopy. 2005;  37 231-235