Ruptured pseudoaneurysm with gastrointestinal bleeding is a rare but frequently fatal complication in patients with pancreatitis. Arteriographic embolization of visceral artery pseudoaneurysms is a safe and highly effective technique for the identifi-cation and treatment of hemorrhage even in criti-cally ill patients. We report a case of massive hematemesis caused by rupture of a pseudoa-neurysm successfully treated by transcatheter embolization.
Key words: Chronic pancreatitis; Embolization; Interventional procedure; Pseudoaneurysm
Bleeding pseudoaneurysm is a rare, but poten-tially life-threatening complication of acute or chronic pancreatitis. Computed tomography (CT) is accurate in the diagnosis of pseudoaneurysms and complicating pseudocysts. Surgical removal of pseudoaneurysm fre-quently requires simultaneous pancreatic resection. Transcatheter arterial embolization is a less invasive, safe and effective management. We describe a case of successfully treated ruptured pseudoaneurysm associ-ated with pseudocyst formation by transcatheter embolization.
CASE REPORT
A 37-year-old man with a history of chronic pan-creatitis (Fig.1a) and pseudocyst formation (Fig.1b) secondary to alcohol abuse was admitted because of sudden onset of epigastric pain and massive fresh blood vomiting for one day. He was then sent to our department for further evaluation and treatment.
On admission, serum amylase was 232 U/L and lipase was 237 U/L. The patient was hemodynamically unstable with hypotension (BP: 86/43 mmHg). The upper gastrointestinal endoscopy revealed a mass-like lesion with erosions at the posterior wall of the duodenal bulb. The abdominal CT was then performed and revealed an oval-shaped strongly enhanced lesion with local fluid accumulation around the pancreatic head region. Chronic pancreatitis with acute exacerba-tion and pseudoaneurysm formaexacerba-tion secondary to pan-creatitis was impressed (Fig. 2a & 2b). Emergency angiography was performed and demonstrated abnormal contrast agent accumulation along the gas-troduodenal artery. Diagnosis of pseudoaneurysm was confirmed (Fig. 3).
After superselective catheterization of gastroduo-denal artery, embolization of the pseudoaneurysm was performed immediately with five pieces of coils. The gastroduodenal artery was successfully occluded with metal coils placed both proximally and distally to the
Reprint requests to: Dr. Yung-Fang Chen
Department of Radiology, China Medical College Hospital. No. 2, Yuh Der Road, Taichung 404, Taiwan, R.O.C.
Percutaneous Transarterial Embolization of
Pseudoaneurysm Secondary to Pancreatitis:
a case report
HSIN-YILAI YUNG-FANGCHEN HSEIN-JARCHIANG WU-CHUNGSHEN
Figure 1. a. Postcontrast CT scan of the abdomen shows atrophy of the body and tail of the pancreas, dilatation of the
pancreatic duct and diffuse pancreatic calcifications. Diffuse chronic calcific pancreatitis is considered. b. Postcontrast CT scan of the abdomen shows a pseudocyst (—) with well-defined wall at the pancreatic head in a patient with chronic pancreatitis.
1a 1b
Figure 2. a. and b. Precontrast and postcontrast CT scan of the abdomen at the level of the head of the pancreas shows a
rounded fluid collection with strongly oval-shaped enhanced content in the peri-pancreatic head region, indicating a pseudoaneurysm secondary to pancreatitis. The pseudoaneurysm can be clearly identified as a vascular structure surrounded by a low-attenuation blood clot.
creatic-duodenal, and hepatic arteries [1]. In our case, the pseudoaneurysm was anterior to the pancreatic head, a location near the gastroduodenal artery that runs along the groove between the head of pancreas and the C loop of the duodenum. Some fluid accumu-lation between pancreatic head and duodenum as well as mildly enlarged pancreatic head are seen, indicating pancreatitis in acute stage. Therefore, if acute pancre-atitis was accompanied by a pseudocyst located near peri-pancreatic arteries, the potential development of pseudoaneurysm should be kept in mind.
Pathogenesis of pseudoaneurysm formation of arteries adjacent to the pancreas is digestion of the wall of the artery by pancreatic enzymes [4]. Several mechanisms have been hypothesized, including (a) autodigestion of the wall of the artery by elastase and other pancreatic enzymes that are released as a result of the inflammatory process; (b) formation of enzyme-rich pseudocysts due to ductal rupture in chronic pan-creatitis, which incorporates an adjacent artery; (c) expanding pseudocyst eroding into an adjacent artery [1,2,4]. Because pseudoaneurysms are prone to rupture and will lead to life-threatening hemorrhage, rupture of a pseudoaneurysm should be suspected, if a patient with pancreatitis develops upper GI bleeding without definitely detectable source [2].
The choice of diagnostic test depends on the stability of the patient. In a hemodynamically unstable patient with massive bleeding, angiography is the procedure of choice. However, in a more stable patient and particularly one with obvious gastrointestinal bleeding, upper gastrointestinal endoscopy should be performed at first [1]. The upper GI endoscopy is often non-diagnostic for the massive bleeder because intraluminal blood cannot be adequately cleared. It is also difficult to diagnose the small bowel bleeding beyond the ligament of Treitz, albeit uncommon, by using endoscopy [5]. The RBC labelled G-I bleeding scans and angiography often can localize the site and determine the cause of bleeding when diagnostic endoscopy is unsuccessful.
Both CT and angiography study are accurate in the diagnosis of pseudoaneurysm complicated with pseudocyst [6,7]. Preoperative angiographic diagnosis of gastrointestinal bleeding resulting from pseudo-Figure 3. Superselective angiography demonstrates
abnormal outpouching contrast accumulation in the gastroduodenal artery. Pseudoaneurysm arising from the gastroduodenal artery is confirmed.
Figure 4. Followed angiography after embolization
reveals complete embolization of the pseudoaneurysm. The artery was successfully occluded with metal coils placed both proximally and distally to the pseudoaneurysm.
Figure 5. Followed CT at one month later shows
complete resolution of the pseudoaneurysm and confirmed that the coils were in situ.
approximately 50%; therefore, early diagnosis and treatment are essential [2,7,8]. Once a pseudoa-neurysm has been identified, it should be treated, even if there is not active bleeding [1]. The application of transcatheter arterial embolization of bleeding vessels and pseudoaneurysms has tripled the survival rate of patients with bleeding in acute pancreatitis [8]. The choice of initial treatment includes either transcatheter arterial embolization (TAE) or surgical intervention. In recent years, TAE has replaced surgery as the most effective initial treatment for pseudoaneurysms associ-ated with pancreatitis [2]. Primary resection of the pseudoaneurysm, which frequently requires pancreatic resection; but arteriographic embolization of visceral artery pseudoaneurysm is a safe and highly successful technique for the effective identification and treatment of hemorrhage even in critically ill patients.
Therapeutic angiography is primarily indicated in the frail or severely ill patient who is a poor surgical candidate and is increasingly popular in all acute GI bleeders after unsuccessful therapeutic endoscopy [5]. Selective intra-arterial vasopressin therapy had been considered to be a standard angiographic therapy, but embolotherapy is becoming increasingly popular since microvascular technology has become available [5]. Various embolic materials, such as steel coils or detachable balloons, can be used for TAE, either alone or in combination with spongel. Permanent steel coils are the most frequently used because there is no need for recanalization [2]. In the 1990s, transcatheter embolization has become much safer because of more experience and significant improvements in catheters and guidewires, including development of highly radiopaque coaxial catheter systems as small as 2.2F and open-ended guidewires [5]. Currently, microcoils, either alone or with gelatin sponge pledgets or polyvinyl alcohol particles (diameter, 355 to 500 µm), are considered the safest, most efficacious embolic materials. Gelfoam or alcohol particles are less accu-rately deployed than microcoils because of occasional
In conclusion, since the surgical therapy for pseudoaneurysm in association with high mortality rate, we consider diagnostic angiography followed by transcatheter embolization is a safe and highly suc-cessful treatment of choice for pseudoaneurysm caused by chronic pancreatitis, even in critically ill patients because of the high surgical risk.
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