1826
Rare, but a well known cause of acute abdomen.
Often clinically misdiagnosed because it mimics other intra-abdominal serious conditions.
Caused by the accumulation of blood in the sheath of rectus abdominis, related either a rupture of one of the epigastric arteries or to a direct muscular tear.
A rectus sheath hematoma is enclosed within the aponeuroses of the external oblique, internal oblique, and transversalis muscles, which remain intact, except for the posterior part below the arcuate line, which has only a weak transverse fascia.
Rectus sheath hematoma above the arcuate line is generally caused by damage to the superior epigastric artery and usually is self-limited, unilateral, small and associated with the spindle shaped mass.
Hemorrhage from the inferior epigastric arteries below the arcuate line, are often severe in nature and more likely to cross the midline and expand inferiorly, resulting in peritoneal irritation, abdominal rigidity, and gastrointestinal tract symptoms.
Hemorrhage from the inferior epigastric arteries may also occupy the retropubic space and cause bladder irritation and genitourinary tracT complications.
Occurs more frequently on the right side, about 60% of the time, presumably because right-handed persons put more stress on the right rectus muscle.
Occurs more frequently in the lower quadrants, about 80% of the time.
Its location and rare appearance results in frequent mistaken diagnostic findings with more common intraabdominal maladies such a strangulated hernia, twisted ovarian cysts, intestinal obstruction, neoplasms, perforated colon, pancreatitis, and acute appendicitis.