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.