Thrombosis of the portal vein (PV) or its tributaries following blunt abdominal trauma is very rare and most of the reported cases of injury to the portal venous system have been the result of penetrating wounds. Further portal vein thrombosis after blunt abdominal trauma, which is followed by intestinal obstruction, has not been previously reported. We present what we think is the first such case.

Case Report

A 43-year-old army officer presented with a history of having had a road traffic accident when the car he was driving was hit by a truck. He lost consciousness for a few minutes and after being taken to a casualty department underwent computerized  tomograpy (CT) of the head which was normal. He also had abdominal pain and a CT scan of the abdomen was done at the  same time which was also normal. He was managed conservatively and discharged after four days. He remained  well for one week after which he started having recurrent episodes of colicky abdominal pain, vomiting and obstipation. He was investigated with another CT scan of the abdomen with oral (water) and intravenous contrast which showed an altered echotexture of the liver with an occlusive fresh thrombus  involving the PV, extending into its right branch and proximally into the superior mesenteric vein (SMV) (Figure 1&2). There was luminal narrowing of the distal small bowel with proximal dilatation, suggestive of an ischaemic stricture (Figure 3). There  was no evidence of any other visceral injury. He was referred to our unit for further management. His complete blood counts,  liver function tests, renal function tests and procoagulant screening were all within normal limits. Upper gastrointestinal endoscopy (UGIE) showed only mild duodenitis. The patient was started on low molecular weight heparin and was planned for surgery for his small bowel stricture. On laparotomy, there was a stricture 15 inches from the ileocaecal region which was resected and a side-to-side ileoileal anastomosis was performed. He had an uneventful postoperative course. Histopathological examination of the resected specimen showed that large areas of the mucosa had ulcers and was replaced by inflammatory granulation tissue. There was diffuse, transmural chronic inflammation and fibrosis with nodular fibroserositis. He is presently doing well one year after the operation and the anticoagulants have been continued.

Discussion

The various factors implicated for PV thrombosis include a decrease in portal flow as in cirrhosis, hepatobiliary malignancies and inflammation in the abdomen, or endothelial lesions which initiate thrombus formation such as trauma or surgical injury.[1,2] It is believed that portal vein thrombosis follows a combination of systemic and local insults.[3,4] The various systemic risk factors that have been implicated include coagulation disorders and the use of oral contraceptives.[4] This has been supported by Fried et al[5] who reported a case of superior mesenteric vein thrombosis following blunt abdominal  trauma in a patient with primary antiphospholipid syndrome.However, our patient had no coagulation abnormality and the cause of thrombosis was solely attributed to the blunt trauma to his abdomen.

Only nine cases of portal vein injury following trauma have been reported in the literature[6,7,8,9] and in 8 of them penetrating  trauma was responsible.[10] The time interval between traumaand thrombosis varied between 7 days and 6months.[11] Our patient presented one week of trauma with intestinal obstruction. In fact portal vein thrombosis after blunt trauma is exceedingly rare. In a study by Mattox et al[12] involving 2000 patients, who experienced trauma requiring surgery only 1%  (n=22) had portal vein injury - 17 after gunshot wounds, 3 after stab wounds and only two of these had blunt abdominal trauma. Pearl et al[9] reported that out of 18,900 patients who sustained injury during a 10-year period only 15 patients sustained portal vein injury which was the result of penetrating abdominal trauma.

Previous reports (Table 1) have described clinical presentations with abdominal pain, hepatic functional abnormalities and haematemesis.[13] There have been no cases reported of small bowel stricture following portal vein and superior mesenteric vein thrombosis. There has been only one report of superior mesenteric vein thrombosis with jejuna  stenosis secondary to antithrombin III deficiency, oral contraceptive use and smoking. Although there have been isolated case reports of ischaemic intestinal stricture following mesenteric venous thrombosis,[14] to our knowledge this is the first report of small bowel stricture with PV and SMV thrombosis following blunt abdominal trauma which was managed successfully with resection-anastomosis and anticoagulation. We suggest that an ischaemic stricture may follow mesenteric venous thrombosis which has resulted from blunt trauma to the abdomen.

References

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