Role of imaging in visceral vascular emergencies

Abstract

Differential diagnosis in non-traumatic acute abdomen is broad and unrelated diseases may simulate each other from a clinical perspective. Despite the fact that they are not as common, acute abdominal pain due to diseases related to visceral vessels may be life-threating if not detected and treated promptly. Thrombosis, dissection, and aneurysm in the abdominal visceral arteries or thrombosis in visceral veins may cause acute abdominal pain. Imaging with appropriate protocoling plays a fundamental role in both early diagnosis and determination of the treatment approach in these cases where early treatment can be life-saving. Computed tomography (CT) appears to be the most effective modality for the diagnosis as it provides high detail images in a very short time. Patient cooperation is also a less concern as compared to magnetic resonance imaging (MRI). As the imaging findings may sometimes be really subtle, diagnosis may be difficult especially to inexperienced imagers. Correct protocoling is also very critical to detect arterial abnormalities as visceral arterial abnormalities may not be detectable in portal phase only abdominal CT scans. In this article, we aimed to increase awareness among imaging specialists to these not very common causes of acute abdomen.

Keywords: Acute abdomen; Aneurysm; Dissection; Thrombosis; Vascular emergency; Visceral vessels.

Fig. 1

Bland thrombus. A 49-year-old female with known antiphospholipid antibody syndrome (APS) now presenting with severe right upper quadrant pain and elevated liver function tests. Axial post-contrast abdominal CT image demonstrates diffuse acute thrombosis of the main portal vein (arrows) and its intrahepatic branches (arrowheads)

Fig. 2

Two patients with iatrogenic portal vein thrombosis. a A 65-year-old male with known HCC underwent selective right portal vein embolization for surgical resection. The patient presented with severe epigastric and right upper quadrant pain 14 days after the procedure. Axial post-contrast abdominal CT image demonstrated acute main portal vein thrombosis (arrows). Also, note metallic artifacts in the right liver lobe secondary to embolization coils. b A 55-year-old male with known Hodgkin lymphoma underwent splenic artery embolization because of pancytopenia induced by hypersplenism presents with persistent right upper quadrant pain and elevated liver enzymes. Coronally reformatted post-contrast abdominal CT image demonstrated diffuse portal vein thrombosis (arrows). Also, note is made of diffuse splenomegaly and extensive parenchymal infarcts (asterisks)

Fig. 3

Pylephlebitis. A 56-year-old man with known diabetes presented with acute onset abdominal pain and fever. Coronally reformatted post-contrast abdominal CT image demonstrated diffuse gas and thrombosis within the porto-mesenteric venous axis (arrows). Also, note is made of diffuse wall thickening (arrowheads) in the distal jejunal segment and inflammatory changes within the adjacent mesentery. Laparoscopic resection and histopathological analysis revealed acute jejunal diverticulitis

Fig. 4

Tumor thrombus. A 76-year-old male with known cirrhosis presented with right upper quadrant pain and elevated liver enzymes. a Axial post-contrast arterial phase T1W MR image demonstrates HCC focus within the right liver lobe (arrowheads) with associating tumor within the main and right portal vein branches (arrows). Note contrast enhancement of the thrombus with extending outside the confines of the main portal vein. b DWI image shows high signal intensity representing diffusion restriction of the thrombus within the main portal vein (arrows)

Fig. 5

SMV thrombosis. A 57-year-old female with known history of hepatitis B-related cirrhosis and Behcet’s disease presented to ED with severe abdominal pain and melena. Post-contrast curved MPR CT image shows thrombosed SMV (arrows) with associating severe mesenteric edema. Also, note is made of thickening of small bowel and colon segments (arrowheads) suggestive for venous bowel ischemia. Emergent surgery confirmed imaging findings and the patient underwent extensive bowel resection. The patient expired 3 days after the surgery

Fig. 6

IMV thrombosis. A 70-year-old man presented to ED with severe melena, fever, and abdominal pain. Coronally reformatted post-contrast CT image showed thrombosed IMV (arrows) due to sigmoid colon diverticulitis

Fig. 7

Budd-Chiari syndrome. A 29-year-old female with known Behcet’s disease presented with acute and severe right upper quadrant pain and abdominal distension. Abdominal US study showed fresh thrombus within the hepatic veins (not shown). Subsequent venous phase axial CT scan shows thrombosed hepatic veins (arrows). The liver parenchyma demonstrated heterogeneous contrast enhancement with severe parenchymal heterogeneity

Fig. 8

Budd-Chiari syndrome. A 23-year-old male with factor 5 Leiden mutation presented with acute epigastric pain and elevated liver enzymes. Abdominal US study demonstrated fresh thrombus in the hepatic veins and hepatomegaly. a Axial plane post-contrast CT image showed reduced perfusion within the periphery of the hepatic parenchyma (asterisks) with relatively normal enhancing central parenchyma (arrowheads). b Axial T2W MR image shows diffuse edema and congestion within the peripheral portion of the liver parenchyma (asterisks) which corresponds to non-enhancing liver parenchyma on CT

Fig. 9

Hepatic artery pseudoaneurysm. A 69-year-old female with known inoperable obstructive hilar cholangiocarcinoma cancer treated with palliative biliary stenting. About 3 h after the procedure, the patient experienced severe right upper quadrant pain, hematemesis and hypotension. a Axial post-contrast arterial phase CT image demonstrates a large pseudoaneurysm (arrowheads) right next to the metallic biliary stent. Also, note is made of newly developed intraparenchymal hematoma (arrow) and intraperitoneal high-density free fluid suggestive of hemoperitoneum (asterisk). b Emergent catheter angiography confirmed the presence of pseudoaneurysm (arrow) originating from the right hepatic artery. The pseudoaneurysm was subsequently embolized with coils and the patient recovered rapidly after the procedure

Fig. 10

Hepatic artery pseudoaneurysm. A 42-year-old male with no known significant past medical history presented to emergency department and (ED) with severe right upper quadrant pain and hematemesis. Emergent upper gastrointestinal tract endoscopy demonstrated active fresh blood extravasation through the ampulla of Vater. A plastic stent was placed into the common hepatic duct. a Axial plane post-contrast arterial phase CT image showed multiple pseudoaneurysms within the liver parenchyma. The largest was seen to be originating from the right hepatic artery (arrow). Also noted was contrast within the gallbladder lumen (arrowhead) suggestive for hemobilia. b The largest aneurysm was confirmed with catheter angiography (arrow). Smaller pseudoaneurysms were also noted in different segments of the liver (arrowheads)

Fig. 11

Renal artery embolism. A 47-year-old female with a history of atrial fibrillation presented with acute left flank pain and massive hematuria. Coronally reformatted post-contrast abdominal CT image demonstrates endoluminal embolus within the left renal artery (arrows). There was also a large parenchymal infarct area (arrowheads) in the upper pole of the left kidney

Fig. 12

Spontaneous renal artery dissection. 44-year-old male with known Marfan syndrome presented to ED with acute onset severe left flank pain and massive hematuria. US examination showed enlarged left kidney with decreased color Doppler signal in the upper pole of the kidney parenchyma. a Arterial phase CT angiography image showed flap in the proximal third of the left renal artery (arrow). Also, note is made of large infarct in the upper pole parenchyma (arrowheads). b Emergent catheter angiography confirmed the presence of the intimal flap (arrow)

Fig. 13

Renal artery aneurysm. A 56-year-old male with no past medical history presented to ED with right flank pain. Preliminary US study showed a large cystic mass within the right renal hilum. a Axial arterial phase CT image shows a large renal artery aneurysm (arrows) with no evidence of rupture. b Reformatted volume-rendered image from the same study clearly demonstrates the aneurysm arising from the distal portion of the right renal artery (arrow). The patient was subsequently treated with elective surgery

Fig. 14

Renal artery pseudoaneurysms. A 36-year-old female underwent partial nephrectomy for low-grade RCC presented to ED with left flank pain and hematuria 12 days after the surgery. a Axial post-contrast arterial phase CT image shows a small pseudoaneurysm (arrows) at the resection bed. There was also a hematoma surrounding the pseudoaneurysm. b Selective left renal artery catheter angiography clearly demonstrated the pseudoaneurysm (arrow). The pseudoaneurysm was successfully treated with detachable coils in the same session

Fig. 15

Renal arteriovenous fistula. A 28-year-old female with a history of renal transplantation recently underwent percutaneous renal biopsy for suspected graft rejection. The patient experienced hematuria the day after the biopsy. Doppler US evaluation of the graft kidney demonstrates aliasing in the lower pole parenchyma suggestive for high velocity disturbed flow. The flow waveform was also suggestive for arterialized venous flow with reduced systolic-diastolic difference. The patient underwent CO₂ angiogram with subsequent successful coil embolization

Fig. 16

Renal arteriovenous fistula. A 53-year-old male patient with a known history of nephrotic syndrome of unclear etiology presented to ED with recent-onset left flank pain and hematuria 2 months after percutaneous kidney biopsy. a Arterial phase axial plane post-contrast CT image showed early contrast filling of the dilated left renal vein (arrow). Also, note is made of associating ectatic venous structures within the renal hilum (arrowheads). b Coronal volume rendered image shows dilated left renal vein (arrows) with tortuous fistula tract having fusiform dilations (arrowheads) within the renal hilum. The patient was subsequently treated with surgical ligation and resection

Fig. 17

Tumor thrombus from renal AML. A 42-year-old man with no past medical history now present with acute shortness of breath and hematuria. a Pulmonary CT angiography demonstrates an endoluminal thrombus of macroscopic fat density (arrow) within the left lower lobe pulmonary artery. b Subsequent abdominal CT detected angiomyolipoma (arrows) in the right kidney with tumoral thrombus (arrowheads) in the right renal vein and IVC

Fig. 18

Renal vein thrombosis. A 38-year-old woman with known antiphospholipid antibody syndrome (APS) presents to ED with severe left flank pain and gross hematuria. Coronally reformatted post-contrast CT image demonstrates a large thrombus (arrows) in the left renal vein with minimal extension into the IVC

Fig. 19

Nutcracker syndrome. A 67-year-old male with known aortic aneurysm presented to ED with gross hematuria. The sonographic examination of the abdomen was unremarkable. a Axial plane venous phase CT image shows significant distension of the left renal vein (arrows) with severe and abrupt narrowing in the preaortic area (arrowhead). b The aortomesenteric angle was measured to be 12°. There was no evidence of urinary stone disease or TCC in the same exam. The patient was placed on conservative therapy

Fig. 20

Ovarian vein thrombosis. A 44-year-old female presented to ED with fever and abdominal pain 13 days after laparoscopic myomectomy. Coronally reformatted post-contrast CT image demonstrates acute thrombus (arrows) within the left gonadal vein with extension into the left renal vein

Fig. 21

SMA thrombosis. A 65-year-old male with a previous history of surgically treated intestinal gastrointestinal stromal tumor presented with abdominal pain, distension and tenderness. Coronally reformatted post-contrast CT image demonstrates thrombotic occlusion of SMA (arrow) 4–5 cm distal to its origin. Also, note the presence of air within the walls of the small bowel segments consistent with pneumatosis intestinalis (arrowheads). Surgery confirmed infarcted ileal segments and the patient underwent intestinal resection

Fig. 22

SMA dissection. A 59-year-old male with known COPD presented with severe diffuse abdominal pain. a Axial plane arterial phase CT image shows a linear hypodense thin structure suggestive of an intimal flap within the SMA lumen (arrow). b Coronally reformatted post-contrast arterial phase CT image demonstrates long segment dissection (arrowheads) within the SMA with no extension into the abdominal aorta. The findings were found to be suggestive for isolated SMA dissection

Fig. 23

SMA aneurysm. A 62-year-old female with a past medical history of hypertension and type 2 diabetes now presents to ED with diffuse abdominal pain. a Sagittal plane reformatted post-contrast CT image demonstrates a large saccular aneurysm (arrowheads) originating from the SMA trunk. b Catheter angiography confirmed the presence of the aneurysmal sac (arrowheads) originating from the SMA. The aneurysm was successfully embolized with coils in the same session

Fig. 24

SMA syndrome. A 37-year-old female with no past medical history presented to ED with severe nausea and vomiting. Physical examination revealed a significantly distended abdomen. a Coronally reformatted post-contrast CT image demonstrates a severely distended stomach and proximal duodenum. b Sagittal post-contrast CT image showed markedly decreased aortomesenteric angle and aortomesenteric distance. Findings were found to be consistent with SMA syndrome. Endoscopic study confirmed this diagnosis and revealed no evidence of obstructing endoluminal mass

Fig. 25

Celiac artery dissection. A 37-year-old male with known polyarteritis nodosa presented to ED with excruciating epigastric pain. Axial plane post-contrast CT image demonstrates the intimal flap in the celiac trunk consistent with isolated dissection (arrow). There was no associating abdominal aortic dissection

Fig. 26

Celiac artery dissection. A 47-year-old heavy smoker male with known hypertension presented to ED with sharp epigastric pain. Axial plane post-contrast image shows thickening of the celiac artery wall (arrows) suggestive for intramural hematoma and celiac artery dissection. The patient responded well to conservative medical treatment and follow-up imaging study confirmed the regression of intramural hematoma (not shown)

Fig. 27

Celiac artery thrombosis. A 64-year-old male with known colon cancer treated with chemotherapy presented with severe epigastric pain and elevated liver enzymes. Axial plane post-contrast arterial phase T1W image shows intraluminal thrombus completely obstructing the celiac artery lumen (arrow). There was no extension of this thrombus into the aorta. Also, note was made of associated splenic infarcts (not shown)

Fig. 28

Splenic artery aneurysm. A 48-year-old male with known hepatitis B associated chronic liver disease presented to ED with acute onset severe abdominal pain and hypotension. Coronally reformatted post-contrast MIP image demonstrates a large lobulated splenic artery aneurysm (arrow) in the distal part of splenic artery. There was marked contrast extravasation from this aneurysm (arrowheads) consistent with acute rupture. Also, note is made of another smaller aneurysm (broken arrow) located in the proximal part of the splenic artery

Fig. 29

Gastroduodenal artery pseudoaneurysm. A 55-year-old male patient who underwent Whipple surgery for pancreatic head adenocarcinoma experienced severe abdominal pain and hypotension 2 days after the surgery. a MIP image of arterial phase abdominal CT angiography showed pseudoaneurysm (arrow) at the GDA stump. b Subsequent emergent catheter angiography confirmed the pseudoaneurysm (arrow) at the GDA stump. This pseudoaneurysm was successfully coil embolized