Endoscopic drainage using a lumen-apposing metal stent under contrast-enhanced harmonic endoscopic ultrasonography guidance

Endoscopic ultrasonography-guided transmural drainage (EUS-TMD) is an effective treatment for collections of infected peripancreatic fluid [1]. A novel one-step device consisting of a combined lumen-apposing metal stent (LAMS) and an electrocautery-enhanced delivery system (Hot AXIOS; Boston Scientific, Marlborough, Massachusetts, USA) was recently developed [2] [3]. The stent flange interval is 10-mm long; therefore, the recommended indication for this stent is a fluid collection with a wall of < 10 mm. Evaluating the precise thickness of the cavity wall before this procedure is crucial, and a LAMS should not be used if the operator cannot be certain. Here, we report a case of successful drainage of an infected hematoma using the Hot AXIOS under contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) guidance.

A 70-year-old man was diagnosed with infected walled-off necrosis (WON) caused by acute necrotizing pancreatitis ([Fig. 1 a]). The infection was uncontrolled, even after multiple percutaneous and endoscopic drainage procedures. A step-up surgical necrosectomy [4] was performed and the infection was controlled temporarily; however, a newly formed blood vessel ruptured and the cavity where the WON had previously existed was filled with blood. Although the bleeding was controlled by vascular embolization, re-infection occurred 20 days after the procedure ([Fig. 1 b]).

Fig. 1 Computed tomography scan showing: a an area of infected walled-off necrosis caused by acute necrotizing pancreatitis; b an infected hematoma in the cavity of the previous walled-off necrosis, which was found 20 days after embolization to control bleeding from a ruptured newly formed blood vessel, which had filled the cavity with blood after surgical necrosectomy.

We decided to perform EUS-TMD for the infected hematoma using the Hot AXIOS. However, the lesion contained a large number of blood clots and the wall thickness could not be precisely determined using only B-mode EUS imaging ([Fig. 2 a]). Therefore, we scanned the lesion with CH-EUS. Immediately after injecting a sonographic contrast agent, the contents were clearly identified as an avascular area, and the cavity wall was accurately detected ([Fig. 2 b]). Subsequently, we punctured the lesion safely, which enabled proper deployment of the LAMS ([Fig. 3]; [Video 1]).

Fig. 2 Endoscopic ultrasonography images of the infected hematoma showing: a on B-mode, a large number of blood clots that made it impossible to precisely determine the wall thickness; b after injection of sonographic contrast agent, the clearly defined cavity wall, allowing accurate measurement.

Fig. 3 Computed tomography scan after successful transgastric endoscopic ultrasound-guided infected hematoma drainage using a lumen-apposing metal stent.

Video 1 Endoscopic ultrasonography-guided transluminal drainage of an infected hematoma using a lumen-apposing metal stent under contrast-enhanced harmonic endoscopic ultrasonography guidance.

These findings indicate that CH-EUS could be a useful modality to clearly visualize target lesions in cases where the cavity wall cannot be precisely evaluated for standard EUS-TMD.

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• References

• 1 Walter D, Will U, Sanchez-Yague A. et al. A novel lumen-apposing metal stent for endoscopic ultrasound-guided drainage of pancreatic fluid collections: a prospective cohort study. Endoscopy 2015; 47: 63-67
• 2 Teoh AY, Binmoeller KF, Lau JY. Single-step EUS-guided puncture and delivery of a lumen-apposing stent for gallbladder drainage using a novel cautery-tipped stent delivery system. Gastrointest Endosc 2014; 80: 1171
• 3 Galasso D, Baron TH, Attili F. et al. Endoscopic ultrasound-guided drainage and necrosectomy of walled-off pancreatic necrosis using a metal stent with an electrocautery-enhanced delivery system and hydrogen peroxide. Endoscopy 2015; 47 (Suppl. 01) E68
• 4 van Santvoort HC, Besselink MG, Bakker OJ. et al. A step-up approach or open necrosectomy for necrotizing pancreatitis. NEJM 2010; 362: 1491-1502