RARE  ARTERIAL  AND  VENOUS  ANEURYSMS  OF  THE  GASTROINTESTINAL  TRACT  Alysha  Vartevan  D.O.,    Patricio  Rossi  M.D.,  Daryl  Eber  M.D,  Javier  Casillas  M.D,  Beatrice  Madrazo  M.D.    

DEPARTMENT  OF  RADIOLOGY,  LARKIN  COMMUNITY  HOSPITAL/NOVA  SOUTHEASTERN  COLLEGE  OF  OSTEOPATHIC  MEDICINE  

Splanchnic   aneurysms   consNtute   an  uncommon,  but  clinically  relevant,  form  of  abdominal  vascular  disease  which   shows   a   high   mortality   rate   in   emergency  surgery.   The   arteries   involved   include:   splenic,  hepaNc,   celiac,   superior   mesenteric,   ileocolic,  gastroduodenal,   and   inferior   mesenteric.   Intra-­‐abdominal  venous  aneurysms  can  also  occur  such  as  portal   vein   aneurysms   and   superior  mesenteric   vein  aneurysms.   The   paNents   can   present  asymptomaNcally   with   non-­‐specific   abdominal   pain  or  with   intense  pain   and  hemodynamic   compromise  requiring   emergent   surgical   intervenNon.   The   most  common   intra-­‐abdominal   aneurysms   include   aorNc,  iliac   artery,   and   splenic   artery.  We   present   cases   of  rare   intra-­‐abdominal     aneurysms   including   superior  mesenteric   vein,   portal   vein,   gastro-­‐duodenal   artery,  celiac   artery,   ileocolic   artery   and   inferior  mesenteric  artery  aneurysms.  

INTRODUCTION  

Superior   mesenteric   vein   aneurysms   are   very   rare   with   only   10  published  cases  (1).  PaNents  presented  with  vague  abdominal  pain  or   asymptomaNcally.   Because   of   the   anatomical   locaNon,   a  superior   mesenteric   vein   aneurysm   can   compress   adjacent  extrahepaNc   bile   ducts   and   the   duodenum   (2).   Elevated   bilirubin  and   transaminase   levels   were   described   in   2   cases   (1).   Theories  about  the  origin  of  these  aneurysms  have  been  proposed  including  local  inflammatory  processes  and  congenital  abnormaliNes  (2).                

SUPERIOR  MESENTERIC  VEIN  ANEURYSM  

Case 1: 55-year-old female with cryptogenic cirrhosis and portal hypertension that required TIPS. The patient was referred to our institution for further evaluation due to suspected TIPS malfunction.

Fig 1A

Fig 1B

Fig 1C

Aneurysms   of   the   gastroduodenal   artery   are   rare.   They   are   o_en  associated   with   pancreaNc   pathology   or   secondary   to  atherosclerosis.  Computed  tomography  and  Doppler  ultrasound  have  shown   to   be   effecNve   in   idenNfying   these   lesions.   ComplicaNons  include   bleeding   into   the   intraperitoneal   or   retroperitoneal   spaces  (4).   Other   rare   complicaNons   described   include   rupture   into   the  portal  vein  and/or  into  a  pancreaNc  pseudocyst  (5).    

GASTRO-­‐DUODENAL  ARTERY  ANEURYSM  

CASE 5:

Fig 5A

Fig 5B

These   aneurysms   are   also   rare.   They   can   be   asymptomaNc   and  appear   as   an   incidental   finding   on   rouNne   examinaNon  or   they   can  present   as   abdominal   apoplexy   with   sudden   abdominal   pain   and  hemodynamic  collapse.  Atherosclerosis  is  the  most  common  eNology,  however   they   have   been   incidentally   found   in   paNents  with   Ehlers-­‐Danlos  and  Lupus.  

ILEOCOLIC  ARTERY  ANEURYSM  

Fig. 6A-B: CECT shows a large heterogeneous mass in the right side of the abdomen, anterolateral to the aorta (arrowhead) with the epicenter in the mesentery.

Fig 6A

Fig 6B

Aneurysms  of   the   celiac   artery   are   rare   and   include   approximately  4%   of   all   visceral   artery   aneurysms.     These   aneurysms   are   o_en  asymptomaNc  and   incidentally  detected   in   the   sixth  decade  of   life.    In   recent   years,   the   increased   use   of   cross-­‐secNonal   imaging   has  improved  the  detecNon  rate  of  these  aneurysms  (6).    Although  rare,  the  risk  of  rupture  and  other  complicaNons  warrant  elecNve  repair,  especially  in  paNents  with  aneurysms  greater  than  two  cenNmeters.  

CELIAC  ARTERY  ANEURYSM  

CASE 7: Celiac Artery Aneurysms

CASE 8:

Fig. 7A: Plain CT shows a large, oval, irregular structure with a calcified wall (red arrow) located anterolateral to the aorta (arrowhead). Note the areas of increase density representing acute bleed (blue arrow). Fig. 7B: CECT shows the irregular lumen and demonstrates active extravasation (arrowheads).

Fig 7A Fig 7B

Fig 8: CECT shows a fusiform celiac artery aneurysm of 2.0 cm in diameter (black arrow). Patient was post-op AAA repair.

Aneurysms  of   the   Inferior  Mesenteric  Artery   (IMA),  Arch  of  Riolan,  are   very   rare,   accounNng   for   only   0.5%   of   all   visceral   arterial  aneurysms.   The   most   common   cause   of   these   aneurysms   is  atherosclerosis.  The  most  common   locaNon   for   these  aneurysms   is  in  the  proximal  trunk  of  the  artery.  The  most  common  manifestaNon  of  an   IMA  aneurysm  is  an  asymptomaNc  pulsaNle  abdominal  mass.  Once  diagnosed,  the  method  of  choice  for  treatment  is  surgical(7).  

Inferior  Mesenteric  Artery    

Case 9: Arch of Riolan Aneurysm and Polyarteritis Nodosa

Fig 9A

Fig 9B

Fig 9C

Aneurysm   of   the   portal   vein,   iniNally   described   by   Barzilai   and  Kleckner   in   1956   (3),   is   an   uncommon   enNty   with   less   than   one  hundred  published  cases  worldwide.    These  aneurysms  are  defined  by  an   increase   focal  diameter  of   the  portal  vein  greater   than  one  and   a   half   to   two   cenNmeters.   It   most   commonly   occurs   at   the  juncNon   of   the   superior   mesenteric   and   splenic   veins   or   at   the  portal  bifurcaNon.    Portal  vein  aneurysms  can  occur  secondarily  in  the   seings   of   portal   hypertension,   pancreaNNs,   trauma,   and  hepatocellular   disease.     Histopathologically,   these   acquired  aneurysms  can  exhibit   inNmal   thickening  and  medial  hypertrophy.    However,   the   lack   of   portal   hypertension   or   other   pathologic  processes   in   several   reported   cases   of   portal   vein   aneurysms  support   other   proposed   eNologies   including   congenital   origin.    Among   these   congenital   causes,   an   intrinsic   weakness   of   the  vascular  wall  or  failure  of  regression  of  the  right  primiNve  vitelline  vein  have  been  proposed  (2).    

Portal  Vein  Aneurysm  

Case 2: 51-year-old male complaining of non-specific abdominal pain

Case 3: 45-year-old male with incidental finding on US

Case 4: 48-year-old female, complaining of right upper quadrant pain

Fig. 2A-B: Contrast enhanced CT images through the hepatic hilum demonstrate a homogeneously enhancing round structure with markedly different diameters at the two shown levels.

Fig. 3A: CT image shows a large oval hypodensity in the region of the porta hepatis (arrow). Fig. 3B: Axial T1-W image demonstrates flow void signal in the same region. Fig. 3C: T2-W Fat Sat. sequence shows focal hyperintensity with flow void in the periphery compatible with turbulent flow. The combination of these findings is consistent with a portal vein aneurysm. Note the incidental simple cysts in the left lobe of the liver.

Fig. 4A: Non contrast T1-W shows focal oval dilatation with flow void signal at the junction of the main and right portal veins. In Fig. 4B this structure demonstrates strong homogeneous enhancement identical to the adjacent portal vein branches. Gray scale US shown in Fig. 4C : again confirms the presence of the lesion. These findings were diagnostic of a proximal right portal vein aneurysm.

Fig 2A

Fig 2B

Fig 3A Fig 3B Fig 3C

Fig 4A Fig 4B Fig 4C

REFERENCES: 1- Wolosker N, Zerati, et al. Aneurysm of Superior Mesenteric Vein: Case report with a 5 year follow-up and review of the literature. J Vascular Surgery 2004; 39: 459-461. 2- Furcher A. and Turner M. Aneurysms of the portal vein and superior mesenteric vein. Abdominal

Imaging 1997; 22: 287-292. 3- Barzilai R. and Kleckner M.S. Jr. Hemocholecyst following ruptured aneurysm of portal vein. Archives of Surgery 1956; 72: 725-727. 4- Jamal HZ, and KP Block. Endoscopic appearance of gastroduodenal artery aneurysm. Gastrointestinal Endoscopy 1999;

50:862-863.

Contrast enhanced axial CT image demonstrates the stent inside the main portal vein (arrow), note the numerous collaterals around the right portal vein consistent with partial cavernous transformation (arrowhead).

CECT demonstrates the stent at the level of the portal confluence.

CECT shows a pseudoaneurysm of the SMV (blue arrow). Findings suggest stent migration due to venous dilatation secondary to venous hypertension and subsequent intimal hyperplasia around the proximal aspect of the stent with formation of a distal pseudoaneurysm.

Fg. 5A-B: CECT demonstrating a large heterogeneous mass in the area of the head of the pancreas (arrow). The lesion extends inferiorly and there is a focal area of intense enhancement consistent with a vascular structure. This was consistent with a gastroduodenal artery pseudoaneurysm within a pancreatic pseudocyst. Note the dilatation of the pancreatic duct and the presence of calcifications in the pancreas consistent with chronic pancreatitis

CASE 6: Young patient with history of Lupus (SLE), diiffuse abdominal pain and dropping hematocrit

This vascular structure corresponds to the portal vein (arrow). Note the distal dilatation with normal proximal caliber and no signs of portal hypertension. These findings are consistent with a portal vein aneurysm.

In addition there is free fluid around the liver and diffuse high signal consistent with active extravasation (arrow)

Fig. 9A-B: CT without contrast showing an area of high density in the left mesentery and left lower quadrant with small amount of free fluid (arrows). Fig. 9C: T1-W Fat. Sat. post gadolinium image demonstrates a central round hyperintense mass (arrow) surrounded by low signal representing a mesenteric aneurysm with surrounding hematoma.

5- Yeh TS, Jan YY, Jeng LB, et al. Massive extra-enteric gastrointestinal hemorrhage secondary to splanchnic artery aneurysms. Hepatogastroenterology 1997; 44:1152-1156. 6- Soudack M, Gaitini D, and Ofner A. Celiac artery

aneurysm: diagnosis by color Doppler sonography and three-dimensional CT angiography. J Clin Ultrasound 1999; 27:49-51. 7Davidovic Lazar B, Vasic Dragan M, and Colic Momcilo I. Inferior Mesenteric Artery Aneurysm: Case Report and Review of Literature. Asian J of

Surgery 2003; 26 (6); 176-179. CASES PRESENTED FROM LARKIN COMMUNITY HOSPITAL, HEALTH CARE IMAGING, AND JACKSON HOSPITAL UNIVERSITY OF MIAMI

Gastro-Duodenal Artery Pseudoaneurysm

58-year-old male presents with abdominal pain s/p AAA stent