Pancreaticoduodenal Artery Aneurysm Associated with Median Arcuate Ligament Syndrome Marc B. Armstrong,1 Kevin S. Stadtlander,1 and Mark K. Grove,2 Weston, Florida
Aneurysm of the pancreaticoduodenal artery arcade has a well-documented association with occlusion of the celiac axis. The etiology of celiac occlusion is most commonly atherosclerotic disease. Occlusion or severe stenosis of the celiac artery secondary to a median arcuate ligament is less frequently encountered, and symptoms can be vague or completely lacking. We present a case of an asymptomatic 25-year-old woman who, in the course of being evaluated as a potential donor for living-related kidney transplantation, underwent a computed tomography angiography (CTA) scan that revealed an aneurysm of the pancreaticoduodenal artery. The aneurysm, as well as severe compression of the celiac axis by the median arcuate ligament, was confirmed by catheter angiography. The patient underwent successful endovascular coil embolization of the aneurysm. In our review of the existing medical literature, our patient is the youngest reported case of pancreaticoduodenal aneurysm caused by median arcuate ligament syndrome.
Aneurysms of the pancreaticoduodenal artery (PDA) account for only 2% of all splanchnic aneurysms.1 A majority of these aneurysms are pseudoaneurysms secondary to infection or inflammation related to previous surgery, trauma, pancreatitis, or cholecystitis. True aneurysms of the PDA are much less common and may be associated with celiac occlusion secondary to atherosclerosis or caused by compression by a median arcuate ligament.2
CASE REPORT An asymptomatic 25-year-old woman in good health was evaluated at an outside institution as a potential 1 Department of Interventional Radiology, Cleveland Clinic Florida, Weston, FL. 2
Department of Vascular Surgery, Cleveland Clinic Florida, Weston, FL.
Correspondence to: Marc B. Armstrong, MD, MPH, Cleveland Clinic Florida, 3100 Weston Road, Weston, FL 33331, USA; E-mail: [email protected] Ann Vasc Surg 2014; 28: 741.e1–741.e5 http://dx.doi.org/10.1016/j.avsg.2013.06.030 Ó 2014 Elsevier Inc. All rights reserved. Manuscript received: October 2, 2012; manuscript accepted: June 4, 2013; published online: February 2, 2014.
living-related donor for kidney transplantation for a sibling with chronic kidney disease. Her physical examination was unremarkable, and the patient denied any history of abdominal trauma or surgery, pancreatitis, cardiac problems, autoimmune disease, or alcohol or drug abuse. The patient’s only medications were oral contraceptives and oral and intranasal antihistamines for seasonal allergic rhinitis. In the course of the routine donor evaluation, a computed tomography angiography (CTA) scan was performed to assess the renal vascular anatomy. The study confirmed normal renal arteries, but revealed an incidental finding of a 1.4- 1.2-cm aneurysm arising from ‘‘a superior mesenteric artery branch or possibly from a branch of gastroduodenal artery.’’ The patient underwent genetic testing, a CTA scan of the brain, and a consultation with both rheumatology and cardiology services. The genetic tests results were not consistent with EhlerseDanlos syndrome. Serology revealed inflammatory markers for C-reactive protein, erythrocyte sedimentation rate, and antineutrophilic cytoplasmic antibodies to be within normal limits. Screening for methicillin-resistant Staphylococcus aureus, tuberculosis, syphilis, HIV, and viral hepatitis were all negative. Cytomegalovirus serology was positive. Twodimensional echocardiography showed no valvular abnormalities, with an ejection fraction of 60%. A neck bruit led to a Doppler ultrasonography scan of the carotid
741.e1
741.e2 Case reports
Fig. 1. Arrows identify the celiac trunk compression (solid ) by a median arcuate ligament and the associated aneurysm (dotted ) in a previous computed tomography angiography scan. arteries and the lower extremities. No evidence of aneurysm or significant arterial stenosis could be identified in these vascular territories. The CTA scan of the brain revealed no evidence of either aneurysm or stenosis. The patient ultimately presented to our institution for the evaluation of this incidentally identified visceral aneurysm. The departments of vascular surgery and interventional radiology reviewed the above findings and concurred that endovascular embolization was the most appropriate intervention. In preparation for the angiogram and embolization, additional review of the outside CTA scan revealed a compression of the celiac trunk (Fig. 1). Diagnostic catheter angiography, performed with intention to treat, confirmed the presence of the aneurysm arising from a PDA. The angiogram also confirmed severe narrowing at the origin of the celiac artery, best visualized in the lateral view and becoming more pronounced on expiration. These findings are characteristic of extrinsic compression by the median arcuate ligament (MAL; Fig. 2). After the aortogram, the superior mesenteric artery (SMA) was selected for angiography, which revealed retrograde filling of the celiac artery and branches via well-developed pancreaticoduodenal collaterals and the hypertrophied gastroduodenal artery (GDA; Fig. 3). This retrograde flow allowed for visualization of the major branches of the celiac artery, including the splenic, common hepatic, proper hepatic, and left gastric arteries, as well as intrahepatic artery branches. This further supported the hemodynamic significance of the celiac artery narrowing. Finally, subselective angiograms were performed to confirm the exact location of the aneurysm. A microcatheter
Annals of Vascular Surgery
Fig. 2. Arrow shows compression of celiac artery seen on lateral view during angiography.
Fig. 3. Angiography showing hypertrophied gastroduodenal artery (arrows) caused by retrograde filling of the celiac trunk via the superior mesenteric artery. was guided into the celiac trunk through the common hepatic artery and advanced coaxially into the GDA for angiogram. Multiple branches of the GDA were then selectively catheterized for subselective angiograms, including the superior pancreaticoduodenal, dorsal pancreatic, and right gastroepiploic arteries. The aneurysm was identified arising from a branch of the superior PDA (likely the anterior branch) and was selectively catheterized from above via the GDA (Fig. 4). The primary outflow vessels
Vol. 28, No. 3, April 2014
Fig. 4. Angiography confirming microcatheter placement within the aneurysm.
Case reports 741.e3
Fig. 6. Postprocedural angiography scan revealing complete embolization of the aneurysm (arrow). Approximately 1 year postprocedure, the patient was seen for follow-up. The patient had no changes in health status and an abdominopelvic CTA scan revealed intact coil embolization of the artery and no signs new aneurysm formation.
DISCUSSION
Fig. 5. Final coil placement within the aneurysm. were felt to be the gastro-omental and dorsal pancreatic branches, which were shown to flow towards the left upper quadrant (reversed flow) to join the mid- to distal splenic artery. Based on these angiographic findings, coil embolization was performed using hydrogel coils to obliterate the aneurysm sac and the main feeding vessel arising from the superior PDA (Fig. 5). After embolization, angiography revealed complete aneurysm exclusion and preservation of all surrounding named vascular branches (Fig. 6). There were no complications and the patient tolerated the procedure well.
The MAL is the fibrous connection of the left and right diaphragmatic crura typically found at the level of T12eL1 just anterior to the aortic hiatus. Although anterior to the aorta, there are anatomic variations regarding the relation of the MAL to the celiac artery. In many patients, such as the one presented in this case, the origin of the celiac artery is found to be at the level of, or superior to, the MAL.3 During expiration, the branches of the abdominal aorta are displaced superiorly, relative to the crura, increasing the severity of compression.4 A review of the literaturedbeginning with the first reported case by Ferguson in 1895 to the presentdyielded 131 documented cases of PDA aneurysm.5 Of these cases, 81 were associated with occlusion or stenosis of the celiac axis, with 21 attributed to compression by a MAL.2,6e8 The patient in this case study is one of the youngest documented cases of aneurysm involving the pancreaticoduodenal arcades, and is currently the youngest reported patient to have this pathology secondary to celiac compression by the MAL. Although many of the earlier cases were not diagnosed until the patient experienced signs and symptoms of rupture, the increased availability
741.e4 Case reports
of and low threshold for use of advanced imaging techniques, such as CTA and magnetic resonance angiography scanning, has allowed many of these lesions to be identified in asymptomatic patients. Advancements in the management of visceral aneurysms, such as the endovascular embolization used in this case, have provided a lower risk, less invasive alternative to conventional surgical intervention. Although most of the available data supports surgical intervention or endovascular exclusion for a majority of true splanchnic aneurysms >2 cm in diameter, and for all that are symptomatic, the decision to treat and the type of intervention varies according to multiple factors, including size, location, and etiology. The splenic and hepatic arteries, hosting the majority of visceral aneurysms, have significant postrupture mortality rates, and although treatment modalities may vary, there are commonly accepted guidelines regarding when to treat. Aneurysms of the celiac, mesenteric, gastroduodenal, and pancreaticoduodenal arteries are much less common and are associated with a range of pathologies. However, given that aneurysms of the celiac and mesenteric arteries are associated with near 100% mortality after rupture and high rates of becoming symptomatic, respectively, surgical or endovascular intervention is recommended for all patients who are deemed to be at low risk.1,9,10e14 Currently, there is no established guideline for the treatment of unruptured PDA or GDA aneurysms, with various authors making recommendations for intervention depending on size, etiology, and risk factor. Given that surgical treatment of an atherosclerotic celiac artery has been performed after endovascular embolization, some authors have suggested that those associated with celiac compression by a MAL may also require resection of the ligament after definitive aneurysm treatment.15 Suggestions for the management of these aneurysms include surgical ligation, endovascular embolization, and stent graft placement.16 Both the decision to treat and the mode of intervention for our patient took into account that the incidental aneurysm was identified in a healthy, asymptomatic 25-year-old woman, making her a suitable candidate for endovascular therapy. In addition, the patient was perceived to possess a significant risk for rupture because she was of childbearing age and had a foregut aneurysm involving a thin-walled collateral vessel. The pathophysiology of this condition relates to the high-flow state in the SMAdcreated by MAL compression of the celiac arterydthrough the aforementioned thin-walled vessels. This high-flow state
Annals of Vascular Surgery
is transferred through the smaller arterial branches that bifurcate and have increased angularity, leading to increased shear stress on the arterial walls. In our patient, the dynamic compression is also suspected to have caused alternating anterograde/ retrograde blood flow, further increasing turbulence. Studies have strongly suggested that turbulence and increased shearing forces damage the intima, which is comprised of a single layer of endothelial cells, causing changes in permeability, biochemical response, and erosion of the layer entirely.17 These types of insults can result in dysfunction of the medial layer, which is largely responsible for maintaining structure and determining elasticity. It is believed that these processes are associated with the formation of aneurysms in the setting of turbulence and increased flow states.17,18 In addition, it is hypothesized by some authors, and the authors of this case report, that high-flow states focusing increased shear stress at bifurcations and points of increased angularity may contribute to the fact that visceral artery aneurysms are typically saccular in nature. The necessity of surgical decompression of the celiac axis in such patients is controversial. Although seemingly intuitive, given that the underlying pathology remains unchanged after endovascular embolization, there are currently no documented cases of recurrence after successful endovascular embolization of aneurysms believed to be associated with celiac compression or stenosis2; we are not aware of substantial evidence showing the benefits of decompression surgery in such cases. Nevertheless, the potential for development of an initial splanchnic aneurysm in patients with known celiac compression may warrant long-term surveillance, even in the absence of symptoms. In conclusion, although there are accepted recommendations for intervention for aneurysms of the larger arteries of the abdomen, only limited data are available regarding the outcomes of the less frequently encountered splanchnic artery aneurysms, such as the one found in our patient. Given the high mortality rates associated with intraperitoneal rupture of visceral aneurysms, treatment of those rare lesions involving the PDA arcadedeither by surgical or endovascular meansdshould be given strong clinical consideration. Celiac compression caused by MAL syndrome should be considered in any patient with a true aneurysm in this vascular territory. REFERENCES 1. Pasha S, Gloviczki P, Stanson AW, et al. Splanchnic artery aneurysms. Mayo Clin Proc 2007;82:472e9.
Vol. 28, No. 3, April 2014
2. Kallamadi R, deMoya M, Kalva S. Inferior pancreaticoduodenal artery aneurysms in association with celiac stenosis/occlusion. Semin Intervent Radiol 2009;26: 215e23. 3. Paz Z, Rak Y, Rsen A. Anatomical basis for celiac trunk and superior mesenteric artery entrapment. Clin Anat 1991;4:256e64. 4. Manghat NE, Mitchell G, Hay CS, et al. The median arcuate ligament syndrome revisited by CT angiography and the use of ECG gatingda single centre case series and literature review. Br J Radiol 2008;81:735e42. 5. Ferguson F. Aneurysm of the superior pancreaticoduodenalis, with perforation into the common bile duct. Proc New York Path Soc 1895;24. 6. Suzuki K, Kashimura H, Sato M, et al. Pacreaticoduodenal aneurysms associated with celiac axis stenosis due to compression by median arcuate ligament syndrome and celiac plexus. J Gastroenterol 1998;33:434e8. 7. Iyomasa S, Matsuzaki Y, Hiei K, et al. Pancreaticoduodenal artery aneurysm: a case report and review of the literature. J Vasc Surg 1995;22:161e6. 8. Van Ouwerkerk LW. Aneurysm of the arteria pancreaticoduodenalis. Arch Chir Neerl 1951;3:11e7. 9. Abbas MA, Stone WM, Fowl RJ, et al. Splenic artery aneurysms: two decades experience at Mayo Clinic. Ann Vasc Surg 2002;16:442e9.
Case reports 741.e5
10. Stone WM, Abbas M, Cherry KJ, et al. Superior mesenteric artery aneurysms: is presence an indication for intervention? J Vasc Surg 2002;36:234e7. 11. Ghoddousi I, Kojouri K, Fazel I. Coeliac artery aneurysm: a case report. Cardiovasc Surg 1996;4:555e6. 12. Stone WM, Abbas MA, Gloviczki P, et al. Celiac arterial aneurysms: a critical reappraisal of a rare entity. Arch Surg 2002;137:670e4. 13. Carr SC, Mahvi DM, Hoch JR, et al. Visceral artery aneurysm rupture. J Vasc Surg 2001;33:806e11. 14. Shanley CJ, Shah NL, Messina LM. Uncommon splanchnic artery aneurysms: pancreaticoduodenal, gastroduodenal, superior mesenteric, inferior mesenteric, and colic. Ann Vasc Surg 1996;10:506e15. 15. Tarazov PG, Ignashov AM, Pavlovskij AV, et al. Pancreaticoduodenal artery aneurysm associated with celiac axis stenosis: combined angiographic and surgical treatment. Dig Dis Sci 2001;46:1232e5. 16. Nyman U, Svendsen P, Jivegard L, et al. Multiple pancreaticoduodenal aneurysms: treatment with superior mesenteric artery stent-graft placement and distal embolization. J Vasc Interv Radiol 2000;11:1201e5. 17. Lasheras JC. The biomechanics of arterial aneurysms. Ann Rev Fluid Mech 2007;39:293e319. 18. Norman PE, Powell JT. Site specificity of aneurysmal disease. Circulation 2010;121:560e8.
Aneurysm of the pancreaticoduodenal artery arcade has a well-documented association with occlusion of the celiac axis. The etiology of celiac occlusion is most commonly atherosclerotic disease. Occlusion or severe stenosis of the celiac artery secondary to a median arcuate ligament is less frequently encountered, and symptoms can be vague or completely lacking. We present a case of an asymptomatic 25-year-old woman who, in the course of being evaluated as a potential donor for living-related kidney transplantation, underwent a computed tomography angiography (CTA) scan that revealed an aneurysm of the pancreaticoduodenal artery. The aneurysm, as well as severe compression of the celiac axis by the median arcuate ligament, was confirmed by catheter angiography. The patient underwent successful endovascular coil embolization of the aneurysm. In our review of the existing medical literature, our patient is the youngest reported case of pancreaticoduodenal aneurysm caused by median arcuate ligament syndrome.
Aneurysms of the pancreaticoduodenal artery (PDA) account for only 2% of all splanchnic aneurysms.1 A majority of these aneurysms are pseudoaneurysms secondary to infection or inflammation related to previous surgery, trauma, pancreatitis, or cholecystitis. True aneurysms of the PDA are much less common and may be associated with celiac occlusion secondary to atherosclerosis or caused by compression by a median arcuate ligament.2
CASE REPORT An asymptomatic 25-year-old woman in good health was evaluated at an outside institution as a potential 1 Department of Interventional Radiology, Cleveland Clinic Florida, Weston, FL. 2
Department of Vascular Surgery, Cleveland Clinic Florida, Weston, FL.
Correspondence to: Marc B. Armstrong, MD, MPH, Cleveland Clinic Florida, 3100 Weston Road, Weston, FL 33331, USA; E-mail: [email protected] Ann Vasc Surg 2014; 28: 741.e1–741.e5 http://dx.doi.org/10.1016/j.avsg.2013.06.030 Ó 2014 Elsevier Inc. All rights reserved. Manuscript received: October 2, 2012; manuscript accepted: June 4, 2013; published online: February 2, 2014.
living-related donor for kidney transplantation for a sibling with chronic kidney disease. Her physical examination was unremarkable, and the patient denied any history of abdominal trauma or surgery, pancreatitis, cardiac problems, autoimmune disease, or alcohol or drug abuse. The patient’s only medications were oral contraceptives and oral and intranasal antihistamines for seasonal allergic rhinitis. In the course of the routine donor evaluation, a computed tomography angiography (CTA) scan was performed to assess the renal vascular anatomy. The study confirmed normal renal arteries, but revealed an incidental finding of a 1.4- 1.2-cm aneurysm arising from ‘‘a superior mesenteric artery branch or possibly from a branch of gastroduodenal artery.’’ The patient underwent genetic testing, a CTA scan of the brain, and a consultation with both rheumatology and cardiology services. The genetic tests results were not consistent with EhlerseDanlos syndrome. Serology revealed inflammatory markers for C-reactive protein, erythrocyte sedimentation rate, and antineutrophilic cytoplasmic antibodies to be within normal limits. Screening for methicillin-resistant Staphylococcus aureus, tuberculosis, syphilis, HIV, and viral hepatitis were all negative. Cytomegalovirus serology was positive. Twodimensional echocardiography showed no valvular abnormalities, with an ejection fraction of 60%. A neck bruit led to a Doppler ultrasonography scan of the carotid
741.e1
741.e2 Case reports
Fig. 1. Arrows identify the celiac trunk compression (solid ) by a median arcuate ligament and the associated aneurysm (dotted ) in a previous computed tomography angiography scan. arteries and the lower extremities. No evidence of aneurysm or significant arterial stenosis could be identified in these vascular territories. The CTA scan of the brain revealed no evidence of either aneurysm or stenosis. The patient ultimately presented to our institution for the evaluation of this incidentally identified visceral aneurysm. The departments of vascular surgery and interventional radiology reviewed the above findings and concurred that endovascular embolization was the most appropriate intervention. In preparation for the angiogram and embolization, additional review of the outside CTA scan revealed a compression of the celiac trunk (Fig. 1). Diagnostic catheter angiography, performed with intention to treat, confirmed the presence of the aneurysm arising from a PDA. The angiogram also confirmed severe narrowing at the origin of the celiac artery, best visualized in the lateral view and becoming more pronounced on expiration. These findings are characteristic of extrinsic compression by the median arcuate ligament (MAL; Fig. 2). After the aortogram, the superior mesenteric artery (SMA) was selected for angiography, which revealed retrograde filling of the celiac artery and branches via well-developed pancreaticoduodenal collaterals and the hypertrophied gastroduodenal artery (GDA; Fig. 3). This retrograde flow allowed for visualization of the major branches of the celiac artery, including the splenic, common hepatic, proper hepatic, and left gastric arteries, as well as intrahepatic artery branches. This further supported the hemodynamic significance of the celiac artery narrowing. Finally, subselective angiograms were performed to confirm the exact location of the aneurysm. A microcatheter
Annals of Vascular Surgery
Fig. 2. Arrow shows compression of celiac artery seen on lateral view during angiography.
Fig. 3. Angiography showing hypertrophied gastroduodenal artery (arrows) caused by retrograde filling of the celiac trunk via the superior mesenteric artery. was guided into the celiac trunk through the common hepatic artery and advanced coaxially into the GDA for angiogram. Multiple branches of the GDA were then selectively catheterized for subselective angiograms, including the superior pancreaticoduodenal, dorsal pancreatic, and right gastroepiploic arteries. The aneurysm was identified arising from a branch of the superior PDA (likely the anterior branch) and was selectively catheterized from above via the GDA (Fig. 4). The primary outflow vessels
Vol. 28, No. 3, April 2014
Fig. 4. Angiography confirming microcatheter placement within the aneurysm.
Case reports 741.e3
Fig. 6. Postprocedural angiography scan revealing complete embolization of the aneurysm (arrow). Approximately 1 year postprocedure, the patient was seen for follow-up. The patient had no changes in health status and an abdominopelvic CTA scan revealed intact coil embolization of the artery and no signs new aneurysm formation.
DISCUSSION
Fig. 5. Final coil placement within the aneurysm. were felt to be the gastro-omental and dorsal pancreatic branches, which were shown to flow towards the left upper quadrant (reversed flow) to join the mid- to distal splenic artery. Based on these angiographic findings, coil embolization was performed using hydrogel coils to obliterate the aneurysm sac and the main feeding vessel arising from the superior PDA (Fig. 5). After embolization, angiography revealed complete aneurysm exclusion and preservation of all surrounding named vascular branches (Fig. 6). There were no complications and the patient tolerated the procedure well.
The MAL is the fibrous connection of the left and right diaphragmatic crura typically found at the level of T12eL1 just anterior to the aortic hiatus. Although anterior to the aorta, there are anatomic variations regarding the relation of the MAL to the celiac artery. In many patients, such as the one presented in this case, the origin of the celiac artery is found to be at the level of, or superior to, the MAL.3 During expiration, the branches of the abdominal aorta are displaced superiorly, relative to the crura, increasing the severity of compression.4 A review of the literaturedbeginning with the first reported case by Ferguson in 1895 to the presentdyielded 131 documented cases of PDA aneurysm.5 Of these cases, 81 were associated with occlusion or stenosis of the celiac axis, with 21 attributed to compression by a MAL.2,6e8 The patient in this case study is one of the youngest documented cases of aneurysm involving the pancreaticoduodenal arcades, and is currently the youngest reported patient to have this pathology secondary to celiac compression by the MAL. Although many of the earlier cases were not diagnosed until the patient experienced signs and symptoms of rupture, the increased availability
741.e4 Case reports
of and low threshold for use of advanced imaging techniques, such as CTA and magnetic resonance angiography scanning, has allowed many of these lesions to be identified in asymptomatic patients. Advancements in the management of visceral aneurysms, such as the endovascular embolization used in this case, have provided a lower risk, less invasive alternative to conventional surgical intervention. Although most of the available data supports surgical intervention or endovascular exclusion for a majority of true splanchnic aneurysms >2 cm in diameter, and for all that are symptomatic, the decision to treat and the type of intervention varies according to multiple factors, including size, location, and etiology. The splenic and hepatic arteries, hosting the majority of visceral aneurysms, have significant postrupture mortality rates, and although treatment modalities may vary, there are commonly accepted guidelines regarding when to treat. Aneurysms of the celiac, mesenteric, gastroduodenal, and pancreaticoduodenal arteries are much less common and are associated with a range of pathologies. However, given that aneurysms of the celiac and mesenteric arteries are associated with near 100% mortality after rupture and high rates of becoming symptomatic, respectively, surgical or endovascular intervention is recommended for all patients who are deemed to be at low risk.1,9,10e14 Currently, there is no established guideline for the treatment of unruptured PDA or GDA aneurysms, with various authors making recommendations for intervention depending on size, etiology, and risk factor. Given that surgical treatment of an atherosclerotic celiac artery has been performed after endovascular embolization, some authors have suggested that those associated with celiac compression by a MAL may also require resection of the ligament after definitive aneurysm treatment.15 Suggestions for the management of these aneurysms include surgical ligation, endovascular embolization, and stent graft placement.16 Both the decision to treat and the mode of intervention for our patient took into account that the incidental aneurysm was identified in a healthy, asymptomatic 25-year-old woman, making her a suitable candidate for endovascular therapy. In addition, the patient was perceived to possess a significant risk for rupture because she was of childbearing age and had a foregut aneurysm involving a thin-walled collateral vessel. The pathophysiology of this condition relates to the high-flow state in the SMAdcreated by MAL compression of the celiac arterydthrough the aforementioned thin-walled vessels. This high-flow state
Annals of Vascular Surgery
is transferred through the smaller arterial branches that bifurcate and have increased angularity, leading to increased shear stress on the arterial walls. In our patient, the dynamic compression is also suspected to have caused alternating anterograde/ retrograde blood flow, further increasing turbulence. Studies have strongly suggested that turbulence and increased shearing forces damage the intima, which is comprised of a single layer of endothelial cells, causing changes in permeability, biochemical response, and erosion of the layer entirely.17 These types of insults can result in dysfunction of the medial layer, which is largely responsible for maintaining structure and determining elasticity. It is believed that these processes are associated with the formation of aneurysms in the setting of turbulence and increased flow states.17,18 In addition, it is hypothesized by some authors, and the authors of this case report, that high-flow states focusing increased shear stress at bifurcations and points of increased angularity may contribute to the fact that visceral artery aneurysms are typically saccular in nature. The necessity of surgical decompression of the celiac axis in such patients is controversial. Although seemingly intuitive, given that the underlying pathology remains unchanged after endovascular embolization, there are currently no documented cases of recurrence after successful endovascular embolization of aneurysms believed to be associated with celiac compression or stenosis2; we are not aware of substantial evidence showing the benefits of decompression surgery in such cases. Nevertheless, the potential for development of an initial splanchnic aneurysm in patients with known celiac compression may warrant long-term surveillance, even in the absence of symptoms. In conclusion, although there are accepted recommendations for intervention for aneurysms of the larger arteries of the abdomen, only limited data are available regarding the outcomes of the less frequently encountered splanchnic artery aneurysms, such as the one found in our patient. Given the high mortality rates associated with intraperitoneal rupture of visceral aneurysms, treatment of those rare lesions involving the PDA arcadedeither by surgical or endovascular meansdshould be given strong clinical consideration. Celiac compression caused by MAL syndrome should be considered in any patient with a true aneurysm in this vascular territory. REFERENCES 1. Pasha S, Gloviczki P, Stanson AW, et al. Splanchnic artery aneurysms. Mayo Clin Proc 2007;82:472e9.
Vol. 28, No. 3, April 2014
2. Kallamadi R, deMoya M, Kalva S. Inferior pancreaticoduodenal artery aneurysms in association with celiac stenosis/occlusion. Semin Intervent Radiol 2009;26: 215e23. 3. Paz Z, Rak Y, Rsen A. Anatomical basis for celiac trunk and superior mesenteric artery entrapment. Clin Anat 1991;4:256e64. 4. Manghat NE, Mitchell G, Hay CS, et al. The median arcuate ligament syndrome revisited by CT angiography and the use of ECG gatingda single centre case series and literature review. Br J Radiol 2008;81:735e42. 5. Ferguson F. Aneurysm of the superior pancreaticoduodenalis, with perforation into the common bile duct. Proc New York Path Soc 1895;24. 6. Suzuki K, Kashimura H, Sato M, et al. Pacreaticoduodenal aneurysms associated with celiac axis stenosis due to compression by median arcuate ligament syndrome and celiac plexus. J Gastroenterol 1998;33:434e8. 7. Iyomasa S, Matsuzaki Y, Hiei K, et al. Pancreaticoduodenal artery aneurysm: a case report and review of the literature. J Vasc Surg 1995;22:161e6. 8. Van Ouwerkerk LW. Aneurysm of the arteria pancreaticoduodenalis. Arch Chir Neerl 1951;3:11e7. 9. Abbas MA, Stone WM, Fowl RJ, et al. Splenic artery aneurysms: two decades experience at Mayo Clinic. Ann Vasc Surg 2002;16:442e9.
Case reports 741.e5
10. Stone WM, Abbas M, Cherry KJ, et al. Superior mesenteric artery aneurysms: is presence an indication for intervention? J Vasc Surg 2002;36:234e7. 11. Ghoddousi I, Kojouri K, Fazel I. Coeliac artery aneurysm: a case report. Cardiovasc Surg 1996;4:555e6. 12. Stone WM, Abbas MA, Gloviczki P, et al. Celiac arterial aneurysms: a critical reappraisal of a rare entity. Arch Surg 2002;137:670e4. 13. Carr SC, Mahvi DM, Hoch JR, et al. Visceral artery aneurysm rupture. J Vasc Surg 2001;33:806e11. 14. Shanley CJ, Shah NL, Messina LM. Uncommon splanchnic artery aneurysms: pancreaticoduodenal, gastroduodenal, superior mesenteric, inferior mesenteric, and colic. Ann Vasc Surg 1996;10:506e15. 15. Tarazov PG, Ignashov AM, Pavlovskij AV, et al. Pancreaticoduodenal artery aneurysm associated with celiac axis stenosis: combined angiographic and surgical treatment. Dig Dis Sci 2001;46:1232e5. 16. Nyman U, Svendsen P, Jivegard L, et al. Multiple pancreaticoduodenal aneurysms: treatment with superior mesenteric artery stent-graft placement and distal embolization. J Vasc Interv Radiol 2000;11:1201e5. 17. Lasheras JC. The biomechanics of arterial aneurysms. Ann Rev Fluid Mech 2007;39:293e319. 18. Norman PE, Powell JT. Site specificity of aneurysmal disease. Circulation 2010;121:560e8.
