Mayo Clinic College of Medicine and Science
Rochester, Minnesota
Endoscopic ultrasound (EUS) combines the minimally invasive tools of endoscopy with the transluminal visualization and access capabilities of ultrasound. This technology has allowed for the development of many innovative therapies.
In this installment of “Frontiers of EUS,” we address EUS-guided management of afferent limb syndrome and trans-afferent limb endoscopic retrograde cholangiopancreatography (ERCP), various sizes of newly available EUS-guided lumen-apposing metal stents (LAMS), EUS-guided transgastric hepatic duct drainage (hepaticogastrostomy), and EUS-guided management of cholecystitis.
Although these evolving techniques in therapeutic EUS are exciting and important innovations in the field of gastroenterology, it remains critically important that the practice of therapeutic EUS should be built on a solid foundation of anatomy and diagnostic EUS skills.
Cases 1 and 2
Afferent Limb Syndrome Drainage and Afferent Limb Access for ERCP
Afferent limb (or loop) syndrome is a challenging situation often arising from either a malignant or postsurgical adhesion that affects the outflow of the afferent biliary limb. Although surgery or percutaneous drainage have been the mainstay, EUS-guided drainage has become the gold-standard therapy for many patients. In particular, access to the afferent limb is made relatively simple following the paradigm of EUS-guided gastroenterostomy, whereby the dilated and fluid-filled afferent limb is identified on EUS from the stomach, and direct access may be achieved by placing a LAMS to secure the de novo conduit.1,2
Our first case study of EUS-guided intervention for afferent limb syndrome is that of a 68-year-old woman with history of pancreatic ductal adenocarcinoma (PDA). The patient underwent outside treatment of neoadjuvant chemoradiotherapy followed by a pancreaticoduodenectomy that was complicated by EUS/fine needle aspiration (FNA)-confirmed local and regional lymph node recurrence 9 months after surgery. A conglomerate of malignant lymphadenopathy resulted in obstruction and dilation of her afferent limb, leading to significant abdominal discomfort and nausea. Although the biliary anastomosis appeared to be patent and uninvolved, the degree of afferent limb obstruction led to elevated liver enzymes, and a percutaneous transhepatic biliary drain was placed at an outside hospital. She presented to our clinic for evaluation of palliative options, with a preference for internalizing her drainage, if possible. EUS-guided afferent limb drainage was proposed. With the percutaneous drain in place, contrast was injected to fill the afferent limb (Figure 1A), revealing severe malignant-appearing stricture of the downstream afferent limb. The dilated fluid-filled afferent limb was targeted on EUS using an electrocautery-enhanced LAMS (Figure 1B), which was successfully placed from the gastric lumen into the afferent limb, with immediate drainage of bile and contrast (Figure 1C). The percutaneous drain, which had been in place for 2 months, was removed before the procedure was completed.
Another example of EUS-guided afferent limb access is the case of an 87-year-old woman who had been diagnosed 14 years previously with PDA, for which she underwent neoadjuvant chemoradiotherapy followed by a pancreaticoduodenectomy. Six years later, she was diagnosed with afferent limb syndrome that, until recently, was managed with serial dilation of the afferent limb stricture and repeat biopsy. To date, there has been no evidence of tumor recurrence (Figure 2A). More recently, the patient developed multiple episodes of cholangitis that have been managed with long courses of antibiotics due to an inability to adequately dilate the stenosis, severe tortuosity, and less critical stenoses throughout the afferent limb. Due to recent failed endoscopic efforts to reach the biliary anastomosis, biliary access and ductal clearance were obtained via the percutaneous route with interventional radiology (Figure 2A). However, she presented with severe cholangitis and was referred for consideration of EUS-guided LAMS placement and attempted ERCP.
EUS imaging demonstrated the dilated afferent limb. Once an appropriate position in the stomach was identified, a 19-gauge needle was advanced into the afferent limb, and a large quantity of saline, contrast, and methylene blue was injected (Figure 2B). A guidewire was coiled within the afferent limb, over which a 15- × 10-mm LAMS was inserted with the aid of electrocautery. An occlusion balloon and guidewire were advanced through the EUS scope and into the biliary tree from a position within the stomach. Multiple sweeps were performed from both the left and right ducts, removing a large quantity of sludge and stones. This was accomplished without the need to intubate the afferent limb (Figure 2B). Immediately after the procedure and since then, there has been complete resolution of the prior afferent loop syndrome–related symptoms and no evidence of recurrent cholangitis.
Case 3
New LAMS Sizes
A 45-year-old man with no medical history presented 5 weeks after a hospitalization for acute pancreatitis, with abdominal pain, severe early satiety, and a 15-lb weight loss. An initial CT scan demonstrated a 25-cm perigastric fluid collection of walled-off necrosis (WON) extended into the left paracolic gutter. Given the patient’s significant symptoms, he was referred for an EUS-guided cystgastrostomy and necrosectomy. At the time of EUS, the fluid collection was determined to be at least 13 mm from the gastric lumen and was not adherent to the gastric wall (Figure 3A).
Historically, fluid collections too distant (>10 mm) and nonadherent to the gastric wall have required use of alternative off-label biliary- and esophageal-type stents, or pigtail stent drainage. However, several new LAMS of various diameters and lengths now are available for clinical use in the United States (Figure 3B). For this patient, a newer LAMS that is 15 mm in length was chosen and deployed safely, permitting transgastric access to the WON for subsequent necrosectomy (Figure 3C). After initial limited necrosectomy, pigtail stents were placed coaxial to the LAMS to maintain stent patency and drain-dependent areas of the patient’s necrotic collection (Figure 3D). An international multicenter study was presented at Digestive Disease Week 2021 demonstrating the emerging role of this 15-mm LAMS for such nonadherent pancreatic fluid collections.3
Case 4
Hepaticogastrostomy
A 90-year-old woman with primary sclerosing cholangitis presented with marked isolated dilatation of the left hepatic ducts (Figure 4A). Although her cancer antigen 19-9 was minimally elevated at 65 U/mL (normal, <35 U/mL), no mass was seen on cross-sectional imaging. She had undergone 3 failed ERCP procedures for attempted diagnosis and drainage of the dilated left hepatic ducts (Figure 4A). Although the rights ducts were severely diseased, no dominant stricture was seen, and there was no indication for stenting of the visualized ducts. The patient declined any therapy if cholangiocarcinoma were diagnosed but opted for attempted EUS-guided left duct drainage, also known as hepaticogastrostomy, to manage ongoing jaundice and intermittent cholangitis. Hepaticogastrostomy is an emerging technique that requires high-level skill in EUS and ERCP as well as tools and stents particularly designed for this procedure that are being developed.4
In our patient, percutaneous drainage was considered but declined by the patient due to the likely need for multiple interventions and concerns about the discomfort and leakage that often are experienced with long-term percutaneous drainage. EUS detected a large volume of mobile hyperechoic debris that was presumed to represent blood clots and/or mucinous material within the dilated left ducts (Figure 4B). We identified the most suitable EUS position that allowed an ideal stent insertion trajectory that traversed a minimal amount of hepatic parenchyma. The gastric wall was interrogated using color Doppler imaging to identify interposed vessels. The gastric wall, liver parenchyma, and hepatic duct wall were punctured under endosonographic guidance using a 19-gauge needle. The entire tract was dilated using a 4-mm balloon, after which a large volume of blood clots and debris was removed (Figure 4B). An 10-mm × 8-cm covered metal stent was placed into the duct through the cystgastrostomy tract. Then, a 7-Fr × 10-cm double-pigtail plastic stent was placed within the metal stent to help avoid migration (Figure 4B). The patient responded well, with noted improvement in liver function tests and no further episodes of cholangitis. The stents will be left in place indefinitely, given her age and desire to avoid further intervention.
Case 5
EUS-Guided Gallbladder Drainage
A 90-year-old man with a history of known metastatic lung cancer and severe coronary artery disease with ischemic cardiomyopathy presented to the emergency department with right upper quadrant pain and fever. A right upper quadrant ultrasound confirmed gallbladder wall thickening, pericholecystic fluid, and cholecystolithiasis with a positive Murphy’s sign, all consistent with cholecystitis. Surgery was considered an unacceptable risk for the patient due to his malignancy and other comorbid conditions, and he was referred to gastroenterology for endoscopic or percutaneous drainage of the gallbladder. The patient was strongly against having a percutaneous drain in place, so an EUS-guided drainage approach was elected.
In patients with nongangrenous cholecystitis without ascites, EUS-guided cholecystoduodenostomy is used increasingly5 and is the topic of an ongoing prospective international multicenter trial. For our patient, EUS examination of the gallbladder revealed shadowing hyperechoic stones and a thickened gallbladder wall that was closely approximated to the duodenal bulb (Figure 5A). A 10- × 10-mm LAMS was placed across the duodenal and gallbladder walls, resulting in immediate return of pus and bile. His symptoms of cholecystitis resolved completely the day of the procedure. He returned for LAMS removal 4 weeks later, at which time the gallbladder was explored endoscopically (Figure 5B), and all of his small gallstones were removed to the duodenum using a Roth net. Removal of LAMS showed the patent cholecystoduodenostomy (Figure 5C). To prevent recurrence of cholecystitis in nonsurgical candidates, it is our practice to maintain this tract indefinitely by placing side-by-side 7-Fr × 4-cm double-pigtail stents.
Case 6
Don’t Forget Your Diagnostic Skills: Examining the Omentum
An 84-year-old woman presented with fatigue, nausea, and abdominal discomfort. CT revealed locally advanced PDA within the pancreatic tail. Imaging also detected peritoneal carcinomatosis and tumor implants on the liver surface, along with omental deposits with malignant ascites (Figure 6A). EUS was performed for a tissue diagnosis. Imaging confirmed a hypoechoic 1-cm tumor deposit within the greater omentum, and FNA-confirmed peritoneal carcinomatosis.
The differentiation of benign from malignant omentum is important to determine the need for and to guide FNA, with the results often substantially affecting tumor stage and therapy.6 Most malignant omental deposits are hypoechoic-appearing masses, areas of thickening, or nodularity (Figure 6B). In contrast, normal benign omentum appears without a mass, with only minimal thickening or nodularity that is nearly isoechoic to surrounding structures (Figure 6C).
Conclusion
The frontiers of EUS are rapidly changing to include many new endoscopic tools and devices. These assist the therapeutic endoscopist in addressing challenging clinical problems for patients who otherwise may have required surgery or other more invasive treatments. It remains critically important, however, that clinicians exploring the frontiers of EUS have a solid background in anatomy and diagnostic EUS to allow safe, high-quality outcomes for patients.
| Key to Figures: | |
| EUS | endoscopic ultrasound |
| FNA | fine needle aspiration |
| LAMS | lumen-apposing metal stents |
| MRCP | magnetic resonance cholangiopancreatography |
| PSC | primary sclerosing cholangitis |
| WON | walled-off necrosis |
References
- Ligresti D, Amata M, Messina M, et al. Single-step EUS-guided jejunojejunostomy with a lumen-apposing metal stent as treatment for malignant afferent limb syndrome. VideoGIE. 2020;5(4):154-156.
- Sharma P, McCarty TR, Chhoda A, et al. Alternative uses of lumen apposing metal stents. World J Gastroenterol. 2020;26(21):2715-2728.
- Zhang LY, Pawa R, Pawa S, et al. EUS-guided drainage of non-adherent pancreatic fluid collections using the novel 15-mm length lumen-apposing metal stent. Gastrointest Endosc. 2021;93(6 suppl):AB224-AB225.
- Nakai Y, Sato T, Hakuta R, et al. Long-term outcomes of a long, partially covered metal stent for EUS-guided hepaticogastrostomy in patients with malignant biliary obstruction (with video). Gastrointest Endosc. 2020;92(3):623-631.e1.
- Baron TH. EUS-guided gallbladder drainage is as good as laparoscopic cholecystectomy for symptomatic cholelithiasis: wait!…what?! Gastrointest Endosc. 2021;93(3):584-585.
- Levy MJ, Abu Dayyeh BK, Fujii LL, et al. Detection of peritoneal carcinomatosis by EUS fine-needle aspiration: impact on staging and resectability (with videos). Gastrointest Endosc. 2015;81(5):1215-1224.
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Cases From the Frontiers of Endoscopic Ultrasound in 2021
