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Thrombin injection of a pancreaticoduodenal artery pseudoaneurysm after failed attempts at transcatheter embolization
Thrombin injection of a pancreaticoduodenal artery pseudoaneurysm after failed attempts at transcatheter embolization Azad Ghassemi, MD, Daniel Javit, MD, and Evan H. Dillon, MD, New York, NY We describe a case of a pseudoaneurysm of the pancreaticoduodenal artery in a patient with history of cholecystectomy and chronic pancreatitis. Attempts at transcatheter coil embolotherapy failed because of vessel tortuosity. The lesion was then successfully treated by computed tomography-guided direct percutaneous injection of thrombin into the pseudoaneurysm. This technique may be a first line of treatment or a useful adjunct to transcatheter embolization technique. ( J Vasc Surg 2006;43:618-622.)
Pancreaticoduodenal artery pseudoaneurysm is a very rare but potentially lethal complication of pancreatitis.1-3 This lesion is traditionally treated noninvasively by percutaneous transcatheter embolization technique.4-6 There are few reports of successful treatment of splanchnic artery pseudoaneurysm by percutaneous thrombin injection (PTI).5,7-10 We report a case of pancreaticoduodenal artery pseudoaneurysm secondary to pancreatitis that was successfully treated by using computed tomography (CT)guided PTI after three failed attempts at percutaneous transcatheter embolization. CASE REPORT A 77-year-old man presented with abdominal pain and melena. His medical history included hypertension, chronic pancreatitis, and cholecystectomy. A CT scan showed a 5.1-cm ⫻ 4.6-cm, well defined, ovoid, enhancing mass between the pancreatic head and the descending duodenum (Fig 1). The lesion was further evaluated by CT angiography of the upper abdomen that demonstrated a rounded, centrally slow-enhancing lesion. Communication between this lesion and the anteriorly located gastroduodenal artery was visible. Given the location and history of pancreatitis, this lesion most likely represented a pseudoaneurysm. During angiography, the celiac artery was selected with a 4FSos-Omni 3 catheter (AngioDynamics, Queensbury, NY). The Sos-Omni catheter was removed over the wire and a 4F Cobra glide catheter was advanced into the gastroduodenal artery. A Renegade high-flow microcatheter (Boston Scientific, Natick, Mass) was then advanced through the Cobra catheter to selectively cannulate a branch of the superior pancreaticoduodenal artery (Fig 2, A). Two 4-mm platinum micro-coils were deployed into the neck of the aneurysm from the superior pancreaticoduodenal approach. Evaluation of the superior mesenteric artery (SMA) angiogram after coil embolization revealed no definite filling of the Competition of interest: none. Reprint requests: Azad Ghassemi, MD, Lenox Hill Hospital, Department of Radiology, 100 East 77th Street, New York, NY 10021 (e-mail: [email protected]). 0741-5214/$32.00 Copyright © 2006 by The Society for Vascular Surgery. doi:10.1016/j.jvs.2005.11.051
618
pseudoaneurysm from branches of the inferior pancreaticoduodenal artery (Fig 2, B). On repeat CT angiography of the abdomen, the pseudoaneurysm remained patent. A second embolization procedure was performed. This time, however, the entire segment from the proximal right gastroepiploic artery to the mid-gastroduodenal artery was embolized with 4-mm and 5-mm platinum micro coils. The SMA was again catheterized, and no definite filling of the pseudoaneurysm was demonstrated. Follow-up CT angiography of the abdomen, however, demonstrated residual faint patency of the pseudoaneurysm (Fig 3, A). During a third attempt at embolization, a branch of the inferior pancreaticoduodenal artery was demonstrated to contribute flow to the pseudoaneurysm (Fig 3, B). Because of the tortuosity, a Tracker-325 microcatheter (Boston Scientific) could not be advanced up to the neck of the pseudoaneurysm. This vessel was not embolized more proximally owing to the concern of ischemia because the blood supply from the superior pancreaticoduodenal artery had already been compromised from earlier embolizations. After the embolization options had been exhausted, the decision was then made to perform a CT-guided PTI into the pseudoaneurysm. Ultrasound guidance could not be used to perform this procedure because overlying bowel gas obscured the lesion. The patient was placed in the left lateral decubitus position. A 20-cm 22-gauge needle containing an inner metallic stylet was advanced without aspirating between the right kidney and the transverse colon. The path of the needle was confirmed every 2 to 3 cm by rescanning until the tip of the needle was in the patent portion of the pseudoaneurysm (Fig 4, A). The needle should not be allowed to traverse through various structures with impunity because the risk of major organ-specific complications when fine needles (21-gauge or smaller) are used has been reported to be 0.1% to 2%.11 In performing CT-guided pancreatic biopsies, Brandt et al12 reports 66 documented passes through overlying loops of bowel, including seven through the colon, without any side effects. Rothbarth et al13 treated a large intrahepatic aneurysm by direct percuatenous transhepatic injection of thrombin using a 22-gauge needle without major complications. However, to minimize complications, we try to avoid crossing bowel and solid organs unless absolutely necessary.
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Fig 1. A 5.1-cm ⫻ 4.6-cm lesion (arrow) with central slow enhancement in the head of the pancreas.
Fig 2. A, At angiography, a pseudoaneurysm was identified (arrow) upon injecting the gastroduodenal artery. B, Further coil embolization of the distal gastroduodenal artery (arrow). A superior mesenteric artery angiogram demonstrates no definite filling of the pseudoaneurysm.
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Fig 3. A, Computed tomography angiography shows persistence filling of the pseudoaneurysm (arrow) following embolization of the gastroduodenal artery and part of the right gastroepiploic artery. B, During the third embolization attempt, the pseudoaneurysm was seen for the first time (arrow) from the superior mesenteric artery approach by selectively injecting the inferior pancreaticoduodenal branch of this vessel.
Fig 4. A. Axial computed tomography (CT) image shows the tip of a 22-gauge needle tip within the pseudoaneurysm (arrow), through which thrombin was injected. B, A follow-up 4 months later by contrast enhanced CT no longer demonstrates the pseudoaneurysm (arrow). Once the needle was in place, we injected thrombin at a concentration of 1000 U/mL for a total dose of 1300 U. In previous case reports of splanchnic artery pseudoaneurysms, a 500 U bolus dose of thrombin was used and repeated if part of the pseudoaneurysm
was still patent.5,7-9 In these reports, an injection of 1000 U of thrombin was usually sufficient to achieve successful thrombosis of the pseudoaneurysm. Similarly, several studies examining the treatment of femoral artery pseudoaneurysms used a thrombin dose of
JOURNAL OF VASCULAR SURGERY Volume 43, Number 3
Ghassemi, Javit, and Dillon 621
Literature summary of splanchnic artery pseudoaneurysms treated with thrombin Number
Luchs et al7 Cope and Zeit5 Sparrow et al9 Manazer et al10 Chan et al8
T
S
Technique
Complications
Dose (U)
1 1 1 1 1
1 1 1 1 1
TCE and US-guided PTI TCE and fluoro-guided PTI US-guided PTI CT-guided PTI TCE and CT-guided PTI
None None None None None
1000 1000 1000 4000 1000
T, Treated; S, successful; TCE, transcatheter embolization; PTI, percutaneous thrombin injection; US, ultrasound; CT, computed tomography.
500 to 1000 U.14 The size of the aneurysm and active bleeding can affect the amount of thrombin needed to achieve complete thrombosis.10,14 A final CT angiogram demonstrated no evidence of filling of the pseudoaneurysm. Total procedure time was 45 minutes, and there were no procedure-related complications. A follow-up CT scan obtained 4 months later demonstrated continued thrombosis of the pseudoaneurysm (Fig 4, B).
DISCUSSION Aneurysms of small splanchnic arteries are very uncommon. The pancreaticoduodenal arteries account for 2% of all splanchnic artery aneurysms.1,2 Pancreaticoduodenal aneurysms are among the most life-threatening aneurysms, with gastrointestinal hemorrhage occurring in 7% to 15%.3 Pseudoaneurysms at this location are more common than true aneurysms, secondary to pancreatitis.15 Leakage of pancreatic enzymes from an inflamed pancreas results in enzymatic autodigestion of the arterial walls, with pseudoaneurysm formation.16,17 The wall of a pseudocyst can incorporate a visceral artery, converting it into a pseudoaneurysm. Hemorrhage from these pseudoaneurysms is associated with high mortality rate.16 The CT finding of contrast enhancement within or adjacent to a suspected pseudocyst or contiguous with a vascular structure is highly suggestive of pseudoaneurysm formation.18 Other etiologies include atherosclerotic disease, fibrodysplasia, trauma, and congenital anomalies. Angiography may determine the vessel of origin of the pseudoaneurysm as well as provide definitive therapy through embolization with permanent embolic agents such as micro-coils. Both the superior and inferior pancreaticoduodenal arteries may need to be embolized to treat a pseudoaneurysm. Previous case reports in which both arteries were embolized have demonstrated no complications such as bowel or pancreatic ischemia.6,8 Despite many successful reports of minimally invasive endovascular treatment of pancreaticoduodenal artery aneurysms,4-6 certain technical factors may preclude this treatment method. One of these factors is an inability to cannulate the vessel feeding the aneurysm.10,19 In our case, the pseudoaneurysm was embolized from the superior pancreaticoduodenal artery; however, it could not be successfully embolized from a feeding branch of the inferior pancreaticoduodenal artery because of tortuosity. The pseudoaneurysm was finally successfully treated by a direct CT-guided percutaneous injection of thrombin.
Percutaneous thrombin injection was pioneered by Cope and Zeit in 1986.5 This initial series reported four patients treated for peripheral aneurysms by utilizing PTI. More recently, Luchs et al7 treated a pancreatitisrelated pseudoaneurysm. The aneurysm was eventually treated by direct PTI using ultrasound guidance after a failed attempt at transcatheter embolization because of technical difficulties. The Table provides a review of the literature where a splanchnic artery pseudoaneurysm was treated by using thrombin injection along with the dosage of thrombin used. Kemmeter et al20 used fluoroscopic-guided PTI to treat two aneurysms arising from branches of the SMA. Similar to our case report, Chan et al8 initially used transcatheter coil embolization, which appeared successful at angiography, but the final thrombosis of the pseudoaneurysm was achieved by direct PTI. It is therefore important to obtain a postembolization CT scan to assess for residual pseudoaneurysm patency regardless of the appearance of the postembolization angiographic images. In hemodynamically stable patients, splanchnic pseudoaneurysms are often treated noninvasively by transcatheter embolization techniques using micro-coils. However, direct PTI is a relatively safe and effective method for treatment of splanchnic artery pseudoaneurysms. It also has lower associated cost and a shorter overall procedure time compared with endovascular embolization.8 Percutaneous thrombin injection can be both a first-line treatment and a useful adjunct to transcatheter embolization therapy when the pseudoaneurysm is not accessible by catheter technique. CONCLUSION The decision whether to use transcatheter embolization or PTI to treat splanchnic artery aneurysms is made by what is determined to be the easiest approach on a case-bycase basis. A superficial aneurysm that is easily accessible by CT or ultrasound guidance may be approached first with PTI. We believe that transcatheter embolization may be safer than CT-guided PTI because real-time evaluation to the amount of thrombin being injected cannot be accomplished. Accordingly, ultrasound-guided PTI is therefore a safer and more preferred way to treat a splanchnic artery aneurysm because it allows for real-time evaluation of the patency of the aneurysm, thus preventing overinjection of thrombin. Ultrasound-guided PTI also allows visualization
622 Ghassemi, Javit, and Dillon
of the needle track in real time, which lowers the risk of bowel, vascular, or organ injury. However, ultrasoundguided PTI may be limited by overlying bowel gas obscuring the pseudoaneurysm. Further studies of short-term and long-term outcomes of thrombin injection to treat pseudoaneurysm are necessary. REFERENCES 1. Chiou AC, Josephs LG, Menzoian JO. Inferior pancreaticoduodenal artery aneurysm: report of a case and review of literature. J Vasc Surg 1993;17:784-9. 2. Iyomasa S, Matsuzaki Y, Hiei K, Sakaguchi H, Matsunaga H, Yamaguchi Y. Pancreaticoduodenal artery aneurysm: a case report and review of the literature. J Vasc Surg 1995;22:161-6. 3. Mandel S, Jaques PF, Mauro MA, Sanofsky S. Nonoperative management of peripancreatic arterial aneurysms: A 10-year experience. Ann Surg 1987;205:126-8. 4. Golzarian J, Nicaise N, Deviere J, Ghysels M, Wery D, Dussaussois L, et al. Transcatheter embolization of pseudoaneurysms complicating pancreatitis. Cardiovasc Intervent Radiol 1997;20:435-40. 5. Cope C, Zeit R. Coagulation of aneurysms by direct percutaneous thrombin injection. AJR 1986;147:383-7. 6. Mauro MA, Jaques P. Transcatheter management of pseudoaneurysms complicating pancreatitis. J Vasc Interv Radiol 1991;2:527-32. 7. Luchs S, Antonacci V, Reid S, Pagan-Marin H. Vascular and interventional case of the day. Pancreatic head pseudoaneurysm treated with percutaneous thrombin injection. AJR Am J Roentgenol 1999;173: 833-4. 8. Chan R, David E. Reperfusion of splanchnic artery aneurysm following transcatheter embolization: treatment with percutaneous thrombin injection. Cardiovasc Intervent Radiol 2004;27:264-7. 9. Sparrow P, Asquith J, Chalmers N. US-Guided percutaneous injection of pancreatic pseudoaneurysm with thrombin. Cardiovasc Intervent Radiol 2003;26:312-5.
JOURNAL OF VASCULAR SURGERY March 2006
10. Manazer JR, Monzon R, Dietz PA, Moglia R, Gold M. Treatment of pancreatic pseudoaneurysm with percutaneous transabdominal thrombin injection. J Vasc Surg 2003;38:600-2. 11. Cardella J, Bakal CW, Bertino RE, Burke DR, Drooz A, Haskal Z, et al. Quality improvement guidelines for image-guided percutaneous biopsy in adults. J Vasc Interv Radiol 2003;14:S227-30. 12. Brandt KR, Charboneau JW, Stephens DH, Welch TJ, Goellner JR. CT-and US-guided biopsy of the pancreas. Radiology 1993;187: 99-104. 13. Rothbarth LJ, Redmond PL, Kumpe DA. Percutaneous transhepatic treatment of a large intrahepatic aneurysm. AJR Am J Roentgenol 1989;153:1077-8. 14. Kang SS, Labropoulos N, Mansour MA, Baker WH. Percutaneous ultrasound guided thrombin injection: A new method for treating postcatheterization femoral pseudoaneurysms. J Vasc Surg 1998;187: 464-6. 15. Stanley JC, Thompson NW, Fry WJ. Splanchnic artery aneurysms. Arch Surg 1970;10:689-97. 16. Stabile BE, Wilson SE, Debas HT. Reduced mortality from bleeding pseudocysts and pseudoaneurysms caused by pancreatitis. Arch Surg 1983;118:45. 17. Geokas MC. The role of elastase in acute pancreatitis. Arch Pathol 1968;86:135-41. 18. Burke JW, Erickson SJ, Kellum CD, Tegtmeyer CJ, Williamson BR, Hansen MF. Pseudoaneurysms complicating pancreatitis: detection by CT. Radiology 1986;161:447-50. 19. Chiang KS, Johnson CM, McKusick MA, Maus TP, Stanson AW. Management of inferior pancreaticoduodenal artery aneurysms: a 4-year, single center experience. Cardiovasc Intervent Radiol 1994;17: 217-21. 20. Kemmeter P, Bonnell B, VanderKolk W, et al. Percutaneous thrombin injection of splanchnic artery aneurysm: two case reports. J Vasc Interv Radiol 2000;11:469-72.
Submitted Oct 7 2005; accepted Nov 29, 2005.
Pancreaticoduodenal artery pseudoaneurysm is a very rare but potentially lethal complication of pancreatitis.1-3 This lesion is traditionally treated noninvasively by percutaneous transcatheter embolization technique.4-6 There are few reports of successful treatment of splanchnic artery pseudoaneurysm by percutaneous thrombin injection (PTI).5,7-10 We report a case of pancreaticoduodenal artery pseudoaneurysm secondary to pancreatitis that was successfully treated by using computed tomography (CT)guided PTI after three failed attempts at percutaneous transcatheter embolization. CASE REPORT A 77-year-old man presented with abdominal pain and melena. His medical history included hypertension, chronic pancreatitis, and cholecystectomy. A CT scan showed a 5.1-cm ⫻ 4.6-cm, well defined, ovoid, enhancing mass between the pancreatic head and the descending duodenum (Fig 1). The lesion was further evaluated by CT angiography of the upper abdomen that demonstrated a rounded, centrally slow-enhancing lesion. Communication between this lesion and the anteriorly located gastroduodenal artery was visible. Given the location and history of pancreatitis, this lesion most likely represented a pseudoaneurysm. During angiography, the celiac artery was selected with a 4FSos-Omni 3 catheter (AngioDynamics, Queensbury, NY). The Sos-Omni catheter was removed over the wire and a 4F Cobra glide catheter was advanced into the gastroduodenal artery. A Renegade high-flow microcatheter (Boston Scientific, Natick, Mass) was then advanced through the Cobra catheter to selectively cannulate a branch of the superior pancreaticoduodenal artery (Fig 2, A). Two 4-mm platinum micro-coils were deployed into the neck of the aneurysm from the superior pancreaticoduodenal approach. Evaluation of the superior mesenteric artery (SMA) angiogram after coil embolization revealed no definite filling of the Competition of interest: none. Reprint requests: Azad Ghassemi, MD, Lenox Hill Hospital, Department of Radiology, 100 East 77th Street, New York, NY 10021 (e-mail: [email protected]). 0741-5214/$32.00 Copyright © 2006 by The Society for Vascular Surgery. doi:10.1016/j.jvs.2005.11.051
618
pseudoaneurysm from branches of the inferior pancreaticoduodenal artery (Fig 2, B). On repeat CT angiography of the abdomen, the pseudoaneurysm remained patent. A second embolization procedure was performed. This time, however, the entire segment from the proximal right gastroepiploic artery to the mid-gastroduodenal artery was embolized with 4-mm and 5-mm platinum micro coils. The SMA was again catheterized, and no definite filling of the pseudoaneurysm was demonstrated. Follow-up CT angiography of the abdomen, however, demonstrated residual faint patency of the pseudoaneurysm (Fig 3, A). During a third attempt at embolization, a branch of the inferior pancreaticoduodenal artery was demonstrated to contribute flow to the pseudoaneurysm (Fig 3, B). Because of the tortuosity, a Tracker-325 microcatheter (Boston Scientific) could not be advanced up to the neck of the pseudoaneurysm. This vessel was not embolized more proximally owing to the concern of ischemia because the blood supply from the superior pancreaticoduodenal artery had already been compromised from earlier embolizations. After the embolization options had been exhausted, the decision was then made to perform a CT-guided PTI into the pseudoaneurysm. Ultrasound guidance could not be used to perform this procedure because overlying bowel gas obscured the lesion. The patient was placed in the left lateral decubitus position. A 20-cm 22-gauge needle containing an inner metallic stylet was advanced without aspirating between the right kidney and the transverse colon. The path of the needle was confirmed every 2 to 3 cm by rescanning until the tip of the needle was in the patent portion of the pseudoaneurysm (Fig 4, A). The needle should not be allowed to traverse through various structures with impunity because the risk of major organ-specific complications when fine needles (21-gauge or smaller) are used has been reported to be 0.1% to 2%.11 In performing CT-guided pancreatic biopsies, Brandt et al12 reports 66 documented passes through overlying loops of bowel, including seven through the colon, without any side effects. Rothbarth et al13 treated a large intrahepatic aneurysm by direct percuatenous transhepatic injection of thrombin using a 22-gauge needle without major complications. However, to minimize complications, we try to avoid crossing bowel and solid organs unless absolutely necessary.
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Ghassemi, Javit, and Dillon 619
Fig 1. A 5.1-cm ⫻ 4.6-cm lesion (arrow) with central slow enhancement in the head of the pancreas.
Fig 2. A, At angiography, a pseudoaneurysm was identified (arrow) upon injecting the gastroduodenal artery. B, Further coil embolization of the distal gastroduodenal artery (arrow). A superior mesenteric artery angiogram demonstrates no definite filling of the pseudoaneurysm.
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Fig 3. A, Computed tomography angiography shows persistence filling of the pseudoaneurysm (arrow) following embolization of the gastroduodenal artery and part of the right gastroepiploic artery. B, During the third embolization attempt, the pseudoaneurysm was seen for the first time (arrow) from the superior mesenteric artery approach by selectively injecting the inferior pancreaticoduodenal branch of this vessel.
Fig 4. A. Axial computed tomography (CT) image shows the tip of a 22-gauge needle tip within the pseudoaneurysm (arrow), through which thrombin was injected. B, A follow-up 4 months later by contrast enhanced CT no longer demonstrates the pseudoaneurysm (arrow). Once the needle was in place, we injected thrombin at a concentration of 1000 U/mL for a total dose of 1300 U. In previous case reports of splanchnic artery pseudoaneurysms, a 500 U bolus dose of thrombin was used and repeated if part of the pseudoaneurysm
was still patent.5,7-9 In these reports, an injection of 1000 U of thrombin was usually sufficient to achieve successful thrombosis of the pseudoaneurysm. Similarly, several studies examining the treatment of femoral artery pseudoaneurysms used a thrombin dose of
JOURNAL OF VASCULAR SURGERY Volume 43, Number 3
Ghassemi, Javit, and Dillon 621
Literature summary of splanchnic artery pseudoaneurysms treated with thrombin Number
Luchs et al7 Cope and Zeit5 Sparrow et al9 Manazer et al10 Chan et al8
T
S
Technique
Complications
Dose (U)
1 1 1 1 1
1 1 1 1 1
TCE and US-guided PTI TCE and fluoro-guided PTI US-guided PTI CT-guided PTI TCE and CT-guided PTI
None None None None None
1000 1000 1000 4000 1000
T, Treated; S, successful; TCE, transcatheter embolization; PTI, percutaneous thrombin injection; US, ultrasound; CT, computed tomography.
500 to 1000 U.14 The size of the aneurysm and active bleeding can affect the amount of thrombin needed to achieve complete thrombosis.10,14 A final CT angiogram demonstrated no evidence of filling of the pseudoaneurysm. Total procedure time was 45 minutes, and there were no procedure-related complications. A follow-up CT scan obtained 4 months later demonstrated continued thrombosis of the pseudoaneurysm (Fig 4, B).
DISCUSSION Aneurysms of small splanchnic arteries are very uncommon. The pancreaticoduodenal arteries account for 2% of all splanchnic artery aneurysms.1,2 Pancreaticoduodenal aneurysms are among the most life-threatening aneurysms, with gastrointestinal hemorrhage occurring in 7% to 15%.3 Pseudoaneurysms at this location are more common than true aneurysms, secondary to pancreatitis.15 Leakage of pancreatic enzymes from an inflamed pancreas results in enzymatic autodigestion of the arterial walls, with pseudoaneurysm formation.16,17 The wall of a pseudocyst can incorporate a visceral artery, converting it into a pseudoaneurysm. Hemorrhage from these pseudoaneurysms is associated with high mortality rate.16 The CT finding of contrast enhancement within or adjacent to a suspected pseudocyst or contiguous with a vascular structure is highly suggestive of pseudoaneurysm formation.18 Other etiologies include atherosclerotic disease, fibrodysplasia, trauma, and congenital anomalies. Angiography may determine the vessel of origin of the pseudoaneurysm as well as provide definitive therapy through embolization with permanent embolic agents such as micro-coils. Both the superior and inferior pancreaticoduodenal arteries may need to be embolized to treat a pseudoaneurysm. Previous case reports in which both arteries were embolized have demonstrated no complications such as bowel or pancreatic ischemia.6,8 Despite many successful reports of minimally invasive endovascular treatment of pancreaticoduodenal artery aneurysms,4-6 certain technical factors may preclude this treatment method. One of these factors is an inability to cannulate the vessel feeding the aneurysm.10,19 In our case, the pseudoaneurysm was embolized from the superior pancreaticoduodenal artery; however, it could not be successfully embolized from a feeding branch of the inferior pancreaticoduodenal artery because of tortuosity. The pseudoaneurysm was finally successfully treated by a direct CT-guided percutaneous injection of thrombin.
Percutaneous thrombin injection was pioneered by Cope and Zeit in 1986.5 This initial series reported four patients treated for peripheral aneurysms by utilizing PTI. More recently, Luchs et al7 treated a pancreatitisrelated pseudoaneurysm. The aneurysm was eventually treated by direct PTI using ultrasound guidance after a failed attempt at transcatheter embolization because of technical difficulties. The Table provides a review of the literature where a splanchnic artery pseudoaneurysm was treated by using thrombin injection along with the dosage of thrombin used. Kemmeter et al20 used fluoroscopic-guided PTI to treat two aneurysms arising from branches of the SMA. Similar to our case report, Chan et al8 initially used transcatheter coil embolization, which appeared successful at angiography, but the final thrombosis of the pseudoaneurysm was achieved by direct PTI. It is therefore important to obtain a postembolization CT scan to assess for residual pseudoaneurysm patency regardless of the appearance of the postembolization angiographic images. In hemodynamically stable patients, splanchnic pseudoaneurysms are often treated noninvasively by transcatheter embolization techniques using micro-coils. However, direct PTI is a relatively safe and effective method for treatment of splanchnic artery pseudoaneurysms. It also has lower associated cost and a shorter overall procedure time compared with endovascular embolization.8 Percutaneous thrombin injection can be both a first-line treatment and a useful adjunct to transcatheter embolization therapy when the pseudoaneurysm is not accessible by catheter technique. CONCLUSION The decision whether to use transcatheter embolization or PTI to treat splanchnic artery aneurysms is made by what is determined to be the easiest approach on a case-bycase basis. A superficial aneurysm that is easily accessible by CT or ultrasound guidance may be approached first with PTI. We believe that transcatheter embolization may be safer than CT-guided PTI because real-time evaluation to the amount of thrombin being injected cannot be accomplished. Accordingly, ultrasound-guided PTI is therefore a safer and more preferred way to treat a splanchnic artery aneurysm because it allows for real-time evaluation of the patency of the aneurysm, thus preventing overinjection of thrombin. Ultrasound-guided PTI also allows visualization
622 Ghassemi, Javit, and Dillon
of the needle track in real time, which lowers the risk of bowel, vascular, or organ injury. However, ultrasoundguided PTI may be limited by overlying bowel gas obscuring the pseudoaneurysm. Further studies of short-term and long-term outcomes of thrombin injection to treat pseudoaneurysm are necessary. REFERENCES 1. Chiou AC, Josephs LG, Menzoian JO. Inferior pancreaticoduodenal artery aneurysm: report of a case and review of literature. J Vasc Surg 1993;17:784-9. 2. Iyomasa S, Matsuzaki Y, Hiei K, Sakaguchi H, Matsunaga H, Yamaguchi Y. Pancreaticoduodenal artery aneurysm: a case report and review of the literature. J Vasc Surg 1995;22:161-6. 3. Mandel S, Jaques PF, Mauro MA, Sanofsky S. Nonoperative management of peripancreatic arterial aneurysms: A 10-year experience. Ann Surg 1987;205:126-8. 4. Golzarian J, Nicaise N, Deviere J, Ghysels M, Wery D, Dussaussois L, et al. Transcatheter embolization of pseudoaneurysms complicating pancreatitis. Cardiovasc Intervent Radiol 1997;20:435-40. 5. Cope C, Zeit R. Coagulation of aneurysms by direct percutaneous thrombin injection. AJR 1986;147:383-7. 6. Mauro MA, Jaques P. Transcatheter management of pseudoaneurysms complicating pancreatitis. J Vasc Interv Radiol 1991;2:527-32. 7. Luchs S, Antonacci V, Reid S, Pagan-Marin H. Vascular and interventional case of the day. Pancreatic head pseudoaneurysm treated with percutaneous thrombin injection. AJR Am J Roentgenol 1999;173: 833-4. 8. Chan R, David E. Reperfusion of splanchnic artery aneurysm following transcatheter embolization: treatment with percutaneous thrombin injection. Cardiovasc Intervent Radiol 2004;27:264-7. 9. Sparrow P, Asquith J, Chalmers N. US-Guided percutaneous injection of pancreatic pseudoaneurysm with thrombin. Cardiovasc Intervent Radiol 2003;26:312-5.
JOURNAL OF VASCULAR SURGERY March 2006
10. Manazer JR, Monzon R, Dietz PA, Moglia R, Gold M. Treatment of pancreatic pseudoaneurysm with percutaneous transabdominal thrombin injection. J Vasc Surg 2003;38:600-2. 11. Cardella J, Bakal CW, Bertino RE, Burke DR, Drooz A, Haskal Z, et al. Quality improvement guidelines for image-guided percutaneous biopsy in adults. J Vasc Interv Radiol 2003;14:S227-30. 12. Brandt KR, Charboneau JW, Stephens DH, Welch TJ, Goellner JR. CT-and US-guided biopsy of the pancreas. Radiology 1993;187: 99-104. 13. Rothbarth LJ, Redmond PL, Kumpe DA. Percutaneous transhepatic treatment of a large intrahepatic aneurysm. AJR Am J Roentgenol 1989;153:1077-8. 14. Kang SS, Labropoulos N, Mansour MA, Baker WH. Percutaneous ultrasound guided thrombin injection: A new method for treating postcatheterization femoral pseudoaneurysms. J Vasc Surg 1998;187: 464-6. 15. Stanley JC, Thompson NW, Fry WJ. Splanchnic artery aneurysms. Arch Surg 1970;10:689-97. 16. Stabile BE, Wilson SE, Debas HT. Reduced mortality from bleeding pseudocysts and pseudoaneurysms caused by pancreatitis. Arch Surg 1983;118:45. 17. Geokas MC. The role of elastase in acute pancreatitis. Arch Pathol 1968;86:135-41. 18. Burke JW, Erickson SJ, Kellum CD, Tegtmeyer CJ, Williamson BR, Hansen MF. Pseudoaneurysms complicating pancreatitis: detection by CT. Radiology 1986;161:447-50. 19. Chiang KS, Johnson CM, McKusick MA, Maus TP, Stanson AW. Management of inferior pancreaticoduodenal artery aneurysms: a 4-year, single center experience. Cardiovasc Intervent Radiol 1994;17: 217-21. 20. Kemmeter P, Bonnell B, VanderKolk W, et al. Percutaneous thrombin injection of splanchnic artery aneurysm: two case reports. J Vasc Interv Radiol 2000;11:469-72.
Submitted Oct 7 2005; accepted Nov 29, 2005.