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The value of MDCT in diagnosis of splenic artery aneurysms
European Journal of Radiology 65 (2008) 498–502
Review
The value of MDCT in diagnosis of splenic artery aneurysms Cong Sun ∗ , Cheng Liu, Xi-Ming Wang, Dao-Ping Wang Shandong University, Shandong Provincial Medical Imaging Institute, Road jing-wu No. 324, Jinan, Shandong 250021, PR China Received 1 February 2007; received in revised form 22 March 2007; accepted 4 April 2007
Abstract Objective: To evaluate the clinical value of multiple detector computed tomography (MDCT) in the diagnosis and planning the treatment of splenic aneurysms. Methods: Eight cases with splenic artery aneurysms (SAA) were retrospectively reviewed. Sixty four-slice spiral CT scans were performed. Intravenous contrast material was injected at 4 ml/s, and arterial and venous phase images were obtained. Subsequently, arterial phase images were analyzed and made for CT angiography. The diagnosis was made by using axial and reconstructive images. All of the patients were also performed Doppler color echocardiography. Results: All patients showed splenic artery and splenic artery aneurysms clearly with CT arterial phase images. Among them, six patients had splenic artery aneurysms, one had giant splenic artery aneurysms (GSAA) and one had splenic artery pseudoaneurysms. Ultrasound examination only diagnosed six of them. Conclusion: MDCT is a noninvasive and valuable method in diagnosis of splenic artery aneurysms and has high value in determination of treatment plan. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Computed tomography; Angiography; Aneurysm; Splenic artery
Contents 1. 2.
3. 4.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1. Study patients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2. CT technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Introduction Splenic artery aneurysm (SAA) is uncommon even though it is the second most frequent abdominal artery to undergo aneurysmal change [1]. It is a clinically relevant disease. Its importance lies in potential rupture and hemorrhage. Early diagnosis and treatment before rupture are crucial especially to giant ∗
Corresponding author. Tel.: +86 130 6503 2585. E-mail address: [email protected] (C. Sun).
0720-048X/$ – see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrad.2007.04.006
498 498 500 500 501 501 502
splenic artery aneurysms (GSAA) and pseudoaneurysm patients. Recently, with the development of multiple detector computed tomography (MDCT) technique, MDCT can display and diagnose SAA exactly and min-invasiveness, and have high value in determination of treatment plan. 2. Materials and methods The study was approved by the local ethics committee, and written informed consent was obtained from all patients.
C. Sun et al. / European Journal of Radiology 65 (2008) 498–502
499
Fig. 1. Images in 42-year-old woman with giant splenic artery aneurysm. (a) On arterial phase image shows a round heterogeneous lesion with a size of 11 cm × 10.7 cm is located in the region of the splenic hilum posterior to the gastric fundus. And the splenic artery shows enhancement, distended distinctly and is adjacent to the lesion. (b) On venous phase image, the center density of the lesion is isoattenuated to adjacent splenic artery and the peripheral of lesion (thrombus) does not show enhancement. Localized splenic infarction and hemoperitoneum is also noted. (c) MIP image can display the relationship of lesion, vascular and peripheral tissues straightly. The splenic artery is displaced forward superiorly by the large mass and distended to about 9 cm in diameter. And the distal part of splenic artery is shown like a nozzle and in relation to the mass. Punctual calcification is found at the lateral wall of the lesion. (d) VR images show the 3D relationship of lesion, vascular and peripheral tissues straightly and wholly. (e) The Doppler US funding a round mass with mixed echogenicity in the left upper abdomen. (f) The Doppler US with CDFI can show the blood flow circumgyrated deasil in the mass.
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C. Sun et al. / European Journal of Radiology 65 (2008) 498–502
2.1. Study patients Eight patients (three male and five female, age range from 36 years to 52 years) with splenic artery aneurysms (SAA) were in out-patient clinic or hospitalization and treatment from November 2004 to December 2005. All patients were suspected abdominal abnormality underwent 64-slices spiral CT routine abdominal examined. 2.2. CT technique CT was performed with 64-detector row CT scanner (Siemens cardiac sensation 64). The dual-phase spiral CT protocol, arterial and venous phase, was performed. One hundred millilitres of Iohexol (30 g I/100 ml) was intravenously injected with a flow rate of 4 ml/s before examination. Arterial phase
imaging was performed by using bolus tracking. Arterial phase CT data acquisition was initiated 10 s after the attenuation of a region of interest positioned in the aorta at the level of the celiac artery reached 120 HU. Venous phase acquisition was 50–60 s after the arterial phase. CT parameters were set as follows: voltage 120 kV, tube current 160 mAs, collimation 0.75 mm, pitch 1, and reconstruction interval 0.5 mm. Arterial phase images were analyzed and made for CT angiography with post-processing workstation (Volume Wizard). Volume rendering (VR), maximum intensity projection (MIP) and multiple planar reconstructions (MPR) imagings were acquired. Two readers (C.L. and C.S. with 26 years and 10 years of vascular CT experience, respectively) retrospectively evaluated the data.
Fig. 2. Images in 44-year-old woman with splenic artery pseudoaneurysm caused by pancreatitis. (a) Pre-contrast image shows a round heterogeneous lesion with a size of 3.2 cm × 3.5 cm is located behind of the tail of pancreas. And a punctual calcification is found at the lateral wall of it. (b) On arterial phase image, the center of lesion shows enhancement distinctly that is isoattenuating to the splenic artery. The peripheral of lesion does not show enhancement. (c) On venous phase image, the density of lesion decreased and isoattenuating to adjacent splenic artery. (d) VR shows the shape and location of pseudoaneurysm straightly and wholly. And display the 3D relationship of pseudoaneurysm, vascular and peripheral tissues. (e) MIP image displays the location, extension of the pseudoaneurysm and the relationship of the associated blood vessels (splenic artery). (f) CPR image shows the largest stone with a size of 1.0 cm × 1.0 cm in the head of pancreas; the main duct of pancreas dilated obviously, the location and extension of the pseudoaneurysm and also the relationship of lesion, vascular and peripheral tissues in one image.
C. Sun et al. / European Journal of Radiology 65 (2008) 498–502
501
3. Results Eight patients showed splenic artery and splenic artery aneurysms clearly with CT arterial phase images. Among them, the diameter of splenic artery aneurysms was ranged from 0.9 cm to 11 cm, and one case was splenic artery pseudoaneurysms with pancreatitis (Figs. 1–3). Ultrasound examination only diagnosed six of them (the case that the splenic artery aneurysms was 1 cm in diameter and the case that giant splenic artery pseudoaneurysm were not diagnosed correctly). One case for percutaneous endovascular embolization, four cases for surgery and three cases were for clinic follow-up. 4. Discussion The splenic artery is the third most common site of intraabdominal aneurysm formation after the abdominal aorta and iliac arteries. SAAs constitute approximately 60% of all visceral arterial aneurysms [2]. Aneurysms are often symptomatic and usually discovered incidentally. Acute left upper quadrant pain and shock usually indicate rupture of the aneurysm. The morbidity of SAA is the highest (60%) among all visceral artery aneurysms (VAA), and the incidence of SAA is 0.01–0.2% [3,4]. SAA may be found in all age groups, but the peak incidence is in the fifth and sixth decades of life, and they occur more frequently in women [5]. They are of particular interest, because, in contrast to aneurysms of large arteries (abdominal aorta, iliac arteries), atherosclerosis is rarely the primary causative factor [6,7], and hormonal and local hemodynamic factors are implicated in the evolution of most of these aneurysms [7]. In our cases, one was giant pseudoaneurysm that was a rare complication of pancreatitis and associated with pancreatic enzymes eroding the splenic artery (peripancreatic vessels) to cross tissue planes and boundaries. The mean size of splenic artery aneurysms is reported to be 2.1 cm [8]. The size of splenic aneurysms rarely exceeds 3 cm, because of their size must be treated rapidly before rupture. If its size is larger than 3 cm, it will be called GSAA. And GSAA larger than 10 cm are rare. SAAs are diagnosed when a curvilinear calcification is seen in relation to the splenic artery on conventional abdominal radiographs, or incidentally during ultrasound or CT examination of the abdomen. It is reported that the big-sized splenic artery aneurysms or peripancreatic pseudoaneurysms can be displayed by dynamic CT scan or color Doppler sonography, but the little-sized pseudoaneurysms can be displayed only by angiography [9]. On ultrasound examination, SAAs appear as hypoechoic masses in the left upper part of the abdomen. Duplex ultrasound examination may show a holosystolic waveform. Using ultrasound examination, one case little-sized aneurysm and one case pseudoaneurysm had not diagnosed correctly, in our cases. The reasons might be related to resolving power, visual angle and individual experience. Also, ultrasound examination cannot provide 3D images for comprehensive analyses and planning the treatment. On CT scans, SAAs appear as well-defined low-density masses with or without calcifications. Intense enhancement
Fig. 3. Images in 57-year-old man with splenic artery aneurysm. (a) On arterial phase image shows the splenic artery dilated localized with a size of 0.9 cm × 0.9 cm. (b) VR image and (c) CPR image show the relationship of lesion and the splenic artery straightly and wholly.
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within the residual patent lumen following the administration of intravenous contrast medium confirms the diagnosis of an aneurysm. With the development of MDCT technique, enhanced MDCT, especially, using the arterial phase images, can made the data for CT angiography and show the shape and location of SAA straightly, wholly and satisfactorily. The advantage of MDCT is min-invasiveness and can display the location and extension of the lesion and the relationship of the associated blood vessels. In our study, one patient was pancreatitis with pseudoaneurysm. MDCT can show the shape and location of pseudoaneurysm straightly. The stones in duct of the pancreas could also be shown in images. The reason, that cause pseudoaneurysms obviously, that the pseudoaneurysm was a complication of pancreatitis and associated with pancreatic enzymes eroding peripancreatic vessels to cross tissue planes and boundaries. The treatments of the SAA are surgery and percutaneous endovascular embolization. Surgery has been the primary mode of intervention, traditionally. Recently, percutaneous endovascular embolization has been use in the clinical. The treatment of the SAA should aim at electiving resection of splenic artery aneurysm and preserving the spleen whenever possible [10]. It is known that once rupture has occurred this is rarely possible [11]. The choice of surgical procedure is determined by the location of the aneurysm. For aneurysms located at the splenic hilum or in the distal third of the artery, the aneurysm is resected with either the spleen or the spleen and left pancreas. Alternatively, when it is located in the middle third of the splenic artery, proximal and distal ligation of the splenic artery may be attempted and the extensive short gastric vessels will then most of the time prevent an infarction of the retained spleen [4]. Aneurysms located in the proximal third of the splenic artery can be removed without resecting the pancreas and/or spleen, providing that the short gastric vessels are also present and sufficient [12]. Embolization of splenic artery aneurysms requires either direct treatment of the aneurysm or embolization of the entire segment of the splenic artery involved. Direct treatment of an aneurysm requires a saccular configuration with a narrow neck. In situations in which the neck is broad or the aneurysm has a
fusiform configuration, coil packing in the splenic artery proximal and distal to the aneurysm may be necessary. There were some limitations to our study. First, it was retrospective. Second, the cases were not so many. Third, three patients with little-sized aneurysm are being followed up clinically and has not undergone intervention. In conclusions, MDCT scanning, as a min-invasiveness tool, can timely and comprehensively discover splenic artery aneurysm and has high value in determination of treatment plan and improving prognosis. It should be a routine method to display splenic artery and to those suspected splenic artery aneurysm patients. References [1] Hohn DC. Aneurysm of the splenic artery. In: Way LW, editor. Current surgical diagnosis and treatment. New York: Lange; 1990. p. 1–595. [2] Kehagias DT, Tzalonikos MT, Moulopoulos LA, Gouliamos AD, Mourikis DA, Vlahos LJ. MRI of a giant splenic artery aneurysm. B J R 1998;71:444–6. [3] Gerald B, Zelenock MD, James C. Splanchnic artery aneurysms. In: Robert B, Rutherford MD, editors. Vascular surgery. Philadelphia: WB Saunders, Co.; 2000. p. 1370–3. [4] de Perrot M, Buhler L, Deleaval J, Borisch B, Mentha G, Morel P. Management of true aneurysms of the splenic artery. Am J Surg 1998;175: 466–8. [5] Spittel Jr JA, Faurbourn Jf II, Kincaid DW, et al. Aneurysm of the splenic artery. J Am Med Assoc 1961;175:452–6. [6] Trastek VF, Pairolero PC, Joyce JW, Hollier LH, Bernatz PE. Splenic artery aneurysms. Surgery 1982;91:694–9. [7] Stanley JC, Fry WJ. Pathogenesis and clinical significance of splenic artery aneurysms. Surgery 1974;76:898–909. [8] Long CD, Bakshi KR, Kahn MB, Roberts AB. Giant splenic artery aneurysm. Ann Vasc Surg 1993;7(5):474–8. [9] Wang ZK, Li P, Gou WM, et al. Superior mesenteric artery pseudoaneurysm complications of pancreatitis (case report) (Chin). J Clin Radiol 2003;22(10):859. [10] Trastek VF, Pairolero PC, Bernatz PE. Splenic artery aneurysms. World J Surg 1985;9:378–83. [11] Holdsworth RJ, Gunn A. Ruptured splenic artery aneurysm in pregnancy. A review. Br J Obstet Gynaecol 1992;99:595–7. [12] Aravind A, Mandeep D, Lawrence VH, Hyun SK, Matt C, Andrew K. Treatment of splenic artery aneurysm with use of a stent-graft. J Vasc Interv Radiol 2002;13:631–3.
Review
The value of MDCT in diagnosis of splenic artery aneurysms Cong Sun ∗ , Cheng Liu, Xi-Ming Wang, Dao-Ping Wang Shandong University, Shandong Provincial Medical Imaging Institute, Road jing-wu No. 324, Jinan, Shandong 250021, PR China Received 1 February 2007; received in revised form 22 March 2007; accepted 4 April 2007
Abstract Objective: To evaluate the clinical value of multiple detector computed tomography (MDCT) in the diagnosis and planning the treatment of splenic aneurysms. Methods: Eight cases with splenic artery aneurysms (SAA) were retrospectively reviewed. Sixty four-slice spiral CT scans were performed. Intravenous contrast material was injected at 4 ml/s, and arterial and venous phase images were obtained. Subsequently, arterial phase images were analyzed and made for CT angiography. The diagnosis was made by using axial and reconstructive images. All of the patients were also performed Doppler color echocardiography. Results: All patients showed splenic artery and splenic artery aneurysms clearly with CT arterial phase images. Among them, six patients had splenic artery aneurysms, one had giant splenic artery aneurysms (GSAA) and one had splenic artery pseudoaneurysms. Ultrasound examination only diagnosed six of them. Conclusion: MDCT is a noninvasive and valuable method in diagnosis of splenic artery aneurysms and has high value in determination of treatment plan. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Computed tomography; Angiography; Aneurysm; Splenic artery
Contents 1. 2.
3. 4.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1. Study patients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2. CT technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Introduction Splenic artery aneurysm (SAA) is uncommon even though it is the second most frequent abdominal artery to undergo aneurysmal change [1]. It is a clinically relevant disease. Its importance lies in potential rupture and hemorrhage. Early diagnosis and treatment before rupture are crucial especially to giant ∗
Corresponding author. Tel.: +86 130 6503 2585. E-mail address: [email protected] (C. Sun).
0720-048X/$ – see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrad.2007.04.006
498 498 500 500 501 501 502
splenic artery aneurysms (GSAA) and pseudoaneurysm patients. Recently, with the development of multiple detector computed tomography (MDCT) technique, MDCT can display and diagnose SAA exactly and min-invasiveness, and have high value in determination of treatment plan. 2. Materials and methods The study was approved by the local ethics committee, and written informed consent was obtained from all patients.
C. Sun et al. / European Journal of Radiology 65 (2008) 498–502
499
Fig. 1. Images in 42-year-old woman with giant splenic artery aneurysm. (a) On arterial phase image shows a round heterogeneous lesion with a size of 11 cm × 10.7 cm is located in the region of the splenic hilum posterior to the gastric fundus. And the splenic artery shows enhancement, distended distinctly and is adjacent to the lesion. (b) On venous phase image, the center density of the lesion is isoattenuated to adjacent splenic artery and the peripheral of lesion (thrombus) does not show enhancement. Localized splenic infarction and hemoperitoneum is also noted. (c) MIP image can display the relationship of lesion, vascular and peripheral tissues straightly. The splenic artery is displaced forward superiorly by the large mass and distended to about 9 cm in diameter. And the distal part of splenic artery is shown like a nozzle and in relation to the mass. Punctual calcification is found at the lateral wall of the lesion. (d) VR images show the 3D relationship of lesion, vascular and peripheral tissues straightly and wholly. (e) The Doppler US funding a round mass with mixed echogenicity in the left upper abdomen. (f) The Doppler US with CDFI can show the blood flow circumgyrated deasil in the mass.
500
C. Sun et al. / European Journal of Radiology 65 (2008) 498–502
2.1. Study patients Eight patients (three male and five female, age range from 36 years to 52 years) with splenic artery aneurysms (SAA) were in out-patient clinic or hospitalization and treatment from November 2004 to December 2005. All patients were suspected abdominal abnormality underwent 64-slices spiral CT routine abdominal examined. 2.2. CT technique CT was performed with 64-detector row CT scanner (Siemens cardiac sensation 64). The dual-phase spiral CT protocol, arterial and venous phase, was performed. One hundred millilitres of Iohexol (30 g I/100 ml) was intravenously injected with a flow rate of 4 ml/s before examination. Arterial phase
imaging was performed by using bolus tracking. Arterial phase CT data acquisition was initiated 10 s after the attenuation of a region of interest positioned in the aorta at the level of the celiac artery reached 120 HU. Venous phase acquisition was 50–60 s after the arterial phase. CT parameters were set as follows: voltage 120 kV, tube current 160 mAs, collimation 0.75 mm, pitch 1, and reconstruction interval 0.5 mm. Arterial phase images were analyzed and made for CT angiography with post-processing workstation (Volume Wizard). Volume rendering (VR), maximum intensity projection (MIP) and multiple planar reconstructions (MPR) imagings were acquired. Two readers (C.L. and C.S. with 26 years and 10 years of vascular CT experience, respectively) retrospectively evaluated the data.
Fig. 2. Images in 44-year-old woman with splenic artery pseudoaneurysm caused by pancreatitis. (a) Pre-contrast image shows a round heterogeneous lesion with a size of 3.2 cm × 3.5 cm is located behind of the tail of pancreas. And a punctual calcification is found at the lateral wall of it. (b) On arterial phase image, the center of lesion shows enhancement distinctly that is isoattenuating to the splenic artery. The peripheral of lesion does not show enhancement. (c) On venous phase image, the density of lesion decreased and isoattenuating to adjacent splenic artery. (d) VR shows the shape and location of pseudoaneurysm straightly and wholly. And display the 3D relationship of pseudoaneurysm, vascular and peripheral tissues. (e) MIP image displays the location, extension of the pseudoaneurysm and the relationship of the associated blood vessels (splenic artery). (f) CPR image shows the largest stone with a size of 1.0 cm × 1.0 cm in the head of pancreas; the main duct of pancreas dilated obviously, the location and extension of the pseudoaneurysm and also the relationship of lesion, vascular and peripheral tissues in one image.
C. Sun et al. / European Journal of Radiology 65 (2008) 498–502
501
3. Results Eight patients showed splenic artery and splenic artery aneurysms clearly with CT arterial phase images. Among them, the diameter of splenic artery aneurysms was ranged from 0.9 cm to 11 cm, and one case was splenic artery pseudoaneurysms with pancreatitis (Figs. 1–3). Ultrasound examination only diagnosed six of them (the case that the splenic artery aneurysms was 1 cm in diameter and the case that giant splenic artery pseudoaneurysm were not diagnosed correctly). One case for percutaneous endovascular embolization, four cases for surgery and three cases were for clinic follow-up. 4. Discussion The splenic artery is the third most common site of intraabdominal aneurysm formation after the abdominal aorta and iliac arteries. SAAs constitute approximately 60% of all visceral arterial aneurysms [2]. Aneurysms are often symptomatic and usually discovered incidentally. Acute left upper quadrant pain and shock usually indicate rupture of the aneurysm. The morbidity of SAA is the highest (60%) among all visceral artery aneurysms (VAA), and the incidence of SAA is 0.01–0.2% [3,4]. SAA may be found in all age groups, but the peak incidence is in the fifth and sixth decades of life, and they occur more frequently in women [5]. They are of particular interest, because, in contrast to aneurysms of large arteries (abdominal aorta, iliac arteries), atherosclerosis is rarely the primary causative factor [6,7], and hormonal and local hemodynamic factors are implicated in the evolution of most of these aneurysms [7]. In our cases, one was giant pseudoaneurysm that was a rare complication of pancreatitis and associated with pancreatic enzymes eroding the splenic artery (peripancreatic vessels) to cross tissue planes and boundaries. The mean size of splenic artery aneurysms is reported to be 2.1 cm [8]. The size of splenic aneurysms rarely exceeds 3 cm, because of their size must be treated rapidly before rupture. If its size is larger than 3 cm, it will be called GSAA. And GSAA larger than 10 cm are rare. SAAs are diagnosed when a curvilinear calcification is seen in relation to the splenic artery on conventional abdominal radiographs, or incidentally during ultrasound or CT examination of the abdomen. It is reported that the big-sized splenic artery aneurysms or peripancreatic pseudoaneurysms can be displayed by dynamic CT scan or color Doppler sonography, but the little-sized pseudoaneurysms can be displayed only by angiography [9]. On ultrasound examination, SAAs appear as hypoechoic masses in the left upper part of the abdomen. Duplex ultrasound examination may show a holosystolic waveform. Using ultrasound examination, one case little-sized aneurysm and one case pseudoaneurysm had not diagnosed correctly, in our cases. The reasons might be related to resolving power, visual angle and individual experience. Also, ultrasound examination cannot provide 3D images for comprehensive analyses and planning the treatment. On CT scans, SAAs appear as well-defined low-density masses with or without calcifications. Intense enhancement
Fig. 3. Images in 57-year-old man with splenic artery aneurysm. (a) On arterial phase image shows the splenic artery dilated localized with a size of 0.9 cm × 0.9 cm. (b) VR image and (c) CPR image show the relationship of lesion and the splenic artery straightly and wholly.
502
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within the residual patent lumen following the administration of intravenous contrast medium confirms the diagnosis of an aneurysm. With the development of MDCT technique, enhanced MDCT, especially, using the arterial phase images, can made the data for CT angiography and show the shape and location of SAA straightly, wholly and satisfactorily. The advantage of MDCT is min-invasiveness and can display the location and extension of the lesion and the relationship of the associated blood vessels. In our study, one patient was pancreatitis with pseudoaneurysm. MDCT can show the shape and location of pseudoaneurysm straightly. The stones in duct of the pancreas could also be shown in images. The reason, that cause pseudoaneurysms obviously, that the pseudoaneurysm was a complication of pancreatitis and associated with pancreatic enzymes eroding peripancreatic vessels to cross tissue planes and boundaries. The treatments of the SAA are surgery and percutaneous endovascular embolization. Surgery has been the primary mode of intervention, traditionally. Recently, percutaneous endovascular embolization has been use in the clinical. The treatment of the SAA should aim at electiving resection of splenic artery aneurysm and preserving the spleen whenever possible [10]. It is known that once rupture has occurred this is rarely possible [11]. The choice of surgical procedure is determined by the location of the aneurysm. For aneurysms located at the splenic hilum or in the distal third of the artery, the aneurysm is resected with either the spleen or the spleen and left pancreas. Alternatively, when it is located in the middle third of the splenic artery, proximal and distal ligation of the splenic artery may be attempted and the extensive short gastric vessels will then most of the time prevent an infarction of the retained spleen [4]. Aneurysms located in the proximal third of the splenic artery can be removed without resecting the pancreas and/or spleen, providing that the short gastric vessels are also present and sufficient [12]. Embolization of splenic artery aneurysms requires either direct treatment of the aneurysm or embolization of the entire segment of the splenic artery involved. Direct treatment of an aneurysm requires a saccular configuration with a narrow neck. In situations in which the neck is broad or the aneurysm has a
fusiform configuration, coil packing in the splenic artery proximal and distal to the aneurysm may be necessary. There were some limitations to our study. First, it was retrospective. Second, the cases were not so many. Third, three patients with little-sized aneurysm are being followed up clinically and has not undergone intervention. In conclusions, MDCT scanning, as a min-invasiveness tool, can timely and comprehensively discover splenic artery aneurysm and has high value in determination of treatment plan and improving prognosis. It should be a routine method to display splenic artery and to those suspected splenic artery aneurysm patients. References [1] Hohn DC. Aneurysm of the splenic artery. In: Way LW, editor. Current surgical diagnosis and treatment. New York: Lange; 1990. p. 1–595. [2] Kehagias DT, Tzalonikos MT, Moulopoulos LA, Gouliamos AD, Mourikis DA, Vlahos LJ. MRI of a giant splenic artery aneurysm. B J R 1998;71:444–6. [3] Gerald B, Zelenock MD, James C. Splanchnic artery aneurysms. In: Robert B, Rutherford MD, editors. Vascular surgery. Philadelphia: WB Saunders, Co.; 2000. p. 1370–3. [4] de Perrot M, Buhler L, Deleaval J, Borisch B, Mentha G, Morel P. Management of true aneurysms of the splenic artery. Am J Surg 1998;175: 466–8. [5] Spittel Jr JA, Faurbourn Jf II, Kincaid DW, et al. Aneurysm of the splenic artery. J Am Med Assoc 1961;175:452–6. [6] Trastek VF, Pairolero PC, Joyce JW, Hollier LH, Bernatz PE. Splenic artery aneurysms. Surgery 1982;91:694–9. [7] Stanley JC, Fry WJ. Pathogenesis and clinical significance of splenic artery aneurysms. Surgery 1974;76:898–909. [8] Long CD, Bakshi KR, Kahn MB, Roberts AB. Giant splenic artery aneurysm. Ann Vasc Surg 1993;7(5):474–8. [9] Wang ZK, Li P, Gou WM, et al. Superior mesenteric artery pseudoaneurysm complications of pancreatitis (case report) (Chin). J Clin Radiol 2003;22(10):859. [10] Trastek VF, Pairolero PC, Bernatz PE. Splenic artery aneurysms. World J Surg 1985;9:378–83. [11] Holdsworth RJ, Gunn A. Ruptured splenic artery aneurysm in pregnancy. A review. Br J Obstet Gynaecol 1992;99:595–7. [12] Aravind A, Mandeep D, Lawrence VH, Hyun SK, Matt C, Andrew K. Treatment of splenic artery aneurysm with use of a stent-graft. J Vasc Interv Radiol 2002;13:631–3.