Pesquisa

US Quiz of the Month – April 2016

CASE REPORT

An 84 year-old man underwent endovascular stent graft placement into a thoracoabdominal aneurysm five years ago. He presented now with abdominal pain, tachypnea, fever and hypoxia. Contrast abdominopelvic and chest computed tomography showed the thoracoabdominal endograft in proper position; the excluded aneurysmal sac demonstrated increased enhancement and enlargement compared to prior exams, measuring 3.8 cm (Figure 1).

Figure 1: Contrast abdominopelvic and chest computed tomography image – Thoracoabdominal endograft in proper position with increased enhancement and enlargement of the excluded aneurismal sac (3.8 cm).

 

No contrast extravasated into the sac. Blood cultures grew Bacteroides fragilis. Given multiple co-morbidities, advanced age and American Society of Anesthesiologists score of IV, nonoperative treatment of presumed mycotic aneurysm was undertaken. Under general anesthesia, a linear echoendoscope (GF-UCT180, Olympus, Center Valley, PA) was passed into the esophagus. A collection was identified adjacent to the esophagus around the aorta and vascular stent graft, without vascular flow by color Doppler imaging (Figure 2 and 3).

 

 

Figures 2 and 3: Endoscopic ultrasound image – A collection was identified adjacent to the esophagus around the aorta and vascular stent graft; the collection had no vascular flow demonstrated by color Doppler imaging.

 

A 19-gauge needle (Expect, Boston Scientific, Marlborough, MA) was passed through the endoscope, across the esophageal wall into the collection (Figure 4).

Figure 4: Endoscopic ultrasound image – A 19-gauge needle was passed through the endoscope, across the esophageal wall into the collection.

 

Gross pus was aspirated, which subsequently grew Bacteroides fragilis. A 0.025’’ guidewire (Visiglide, Olympus) was advanced into the collection through the needle. Over the guidewire a 10mm diameter by 10mm long fully covered stent (AXIOS EC, Boston Scientific) was deployed across the esophageal wall (Figure 5, 6, 7 and 8).

Figure 5: Endoscopic ultrasound image – A 10mm long fully covered stent was deployed across the esophageal wall under EUS guidance.

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Figures 6 and 7: Endoscopic image – Axios stent deployed across the esophageal wall into the collection. The vascular stent could be visualized through the Axios stent.

Figure 8: Computed tomography image – Sagittal view of the Axios and the vascular stents.

 

Marked clinical improvement occurred. Follow-up computed tomography 48 hours later showed resolution of the excluded aneurysm sac collection Three days later the stent was endoscopically removed (Figure 9), and the endoscope advanced into the mycotic cavity where the vascular stent was visualized (Figure 10).

 

Figures 9 and 10: Endoscopic image – Communication between the esophagus and the collection after removal of the Axios stent. The endoscope is inside the mycotic cavity where the vascular stent can be visualized.

 

After irrigation with sterile saline the esophageal tract was endoscopically clip closed (Resolution®, Boston Scientific) (Figure 11).

Figure 11: Endoscopic image – Closure of the fistula with clips.

 

Barium swallow showed no leak. The patient was discharged home 11 days postprocedurally eating normally and remains well 121 days after initial endoscopic drainage. Long-term suppressive antibiotics were administered.

 

Commentary

Endograft infection occurs in 0.2% to 0.7%1 of patients and represent a difficult management problem; presentations include chronic sepsis, severe acute sepsis and aortoenteric fistulae.1-3 Infections are often delayed; in one study up to 72 months after graft placement.4 Surgery with graft explant is the primary treatment, though with high mortality.2 Percutaneous therapy is primarily reserved for nonoperative patients, though the abscess was not accessible percutaneously in our patient. Endoscopic ultrasound-guided interventions are increasingly used for drainage of collections in close proximity to gastrointestinal lumena.5 There is one previous report of transgastric drainage of a collection around a superior mesenteric artery bypass using a double pigtail stent.6 We are unaware of prior reports of transesophageal drainage of endograft infections involving the aorta with metal stents. Confirmation of lack of communication between the aneurysmal sac and the aorta is mandatory using contrast imaging studies, including Doppler ultrasound at the time of endoscopic drainage.

 

References

1. Hobbs SD, Kumar S, Gilling-Smith GL. Epidemiology and diagnosis of endograft infection. J Cadiovsc Sur 2010;51:5-14

2. Ducasse E, Calisti A, Speziale F, et al. Aortoiliac stent graft infection: current problems and managrment. Ann Vasc Surg 2004;18:521-6

3. Setacci C, De Donato G, Setacci F, et al. Management of abdominal endograft infection. J Cadiovsc Sur 2010;51:33-41

4. Capoccia L, Speziale F, Menna D, et al. Preliminary Results from a National Enquiry of Infection in Abdominal Aortic Endovascular Repair (R.I.-EVAR). Ann Vasc Surg. 2016;30:198-204.

5. Varadarajulu S, Bang JY, Sutton BS, et al. Equal efficacy of endoscopic and surgical cystogastrostomy for pancreatic pseudocyst drainage in a randomized trial. Gastroenterology. 2013;145:583-90.e1.

6. Vila JJ, Ruiz-Clavijo D, de la Higuera BG, et al. EUS-guided transgastric drainage of a peripancreatic collection containing an arterial bypass graft. Gastrointest Endosc. 2015;82:569-70.

Authors

Eduardo Rodrigues-Pinto MD1,2, Guilherme Macedo MD PhD1, Todd H Baron MD2

1. Gastroenterology Department, Centro Hospitalar São João, Porto, Portugal

2. Division of Gastroenterology and Hepatology, University of North Carolina, Chapel Hill, North Carolina, USA