DISCUSSION
Pylephlebitis is defined as a septic thrombosis of the portal vein. It may be caused by infection of organs that drains into the portal venous system. This physio pathologic mechanism was proven in the 70s. The most common involved abdominal infection is colonic diverticulitis, then appendicitis and cholecystitis [2] . The incidence of septic thrombophlebitis of the porto-mesenteric veins due to acute appendicitis was close to 0.4% before 1950. With
improvements of antibiotics and surgery, it has become nowadays much rarer [3] .
Symptoms of pylephlebitis are non-specific. Abdominal signs like abdominal tenderness or
distention and ascites may occur with increasing ischemia. In severe cases with trans mural
infarction and bowel gangrene, peritoneal signs such as rebound tenderness or rigidity should
be observed [4] .
Abdominal computed tomography (ACT) is the most reliable diagnostic imagery. It could find out the primary source of infection, the extent of pylephlebitis, and eventually liver abscesses. Color flow Doppler ultrasound is also a sensitive test for studying the patency of the portal venous system [5, 6] .
During acute appendicitis with SMVT, thrombi are formed rapidly with increasing
inflammation, possibly leading to intestinal oedema, congestion, and eventually necrosis.
Consequently, SMVT should be suggested in case of acute appendicitis with functional
occlusion and unusual appearance of the ileo-cecal junction during appendectomy particularly
in elderly and debilitated patients like in our case.
SMVT can be managed either surgically or by nonoperative approaches. Patients with signs of peritoneal irritation need often surgery for intestinal resection and eventually a thrombectomy. Nonoperative management of SMVT includes both invasive (pharmacologic thrombolysis) and non-invasive procedures.
When SMVT is slowly progressing, the intestinal blood flow remains almost intact thanks to
the development of collaterals so that intestinal necrosis could be avoided. Therefore,
conservative treatment using anticoagulants should be attempted first.
Anticoagulation therapy for pylephlebitis may reduce septic embolization to the liver from
infected portal thrombi and thus would prevent liver abscess formation. However, its use
remains a controversial issue, as its benefit has not been clearly demonstrated. Some authors
[7] reported that heparin adjunction is not necessary for pylephlebitis when the primary
disease such as appendicitis or diverticulitis is well controlled. In this case, anticoagulation
therapy should not be started initially.
Some authors recommended systematic anticoagulation on the presumption of an
hypercoagulable state in addition to the risk of process extension which could lead to an
enteric ischemia [8] . In fact, our patient had probably a hypercoagulable state as she presented
a postoperative pulmonary embolism and she had a SMVT most likely from the beginning but
unfortunately, misdiagnosed. Furthermore, as heparin therapy was started lately (3 days after
appendectomy) she presented fatal intestinal infarction.
Nevertheless, there is still lack of data concerning the optimum duration of anticoagulation. A
short duration seems reasonable in case of septic SMVT without any intestinal infarction or
embolization [9] .
Some authors suggested that interval laparoscopic appendectomy must be performed 2-3 months after treatment with antibiotics and anticoagulants[10, 11] . However, if the inflammation cannot be
controlled by conservative treatment, surgical removal of the primary lesion is mandatory even without signs of intestinal necrosis.
Despite anticoagulation proven efficiency, intravascular infusion of thrombolytics seems efficient with higher rate of recanalization. Furthermore, pharmacologic thrombolysis of clot would facilitate a possible thrombectomy [12] .
In conclusion, septic pylephlebitis is rarely reported as a complication of acute appendicitis.
Due to its uncommon and non-specific symptoms, it is often misdiagnosed and thus still
associated with high mortality rate. Old patients with pain in the right iliac fossa, rarely related to acute appendicitis, should be explored by an abdominal angioscan not only because of possible abscessed caecal tumor but also to look for pylephlebitis and SMVT that is more common in elderly patient [13] . The role of anticoagulation therapy remains controverted but it seems mandatory in case of elderly or debilitated patients who are at high risk of thrombosis
extension and intestinal infarction.