Rectus Sheath Hematoma

Rectus sheath hematoma is bleeding into the sheath of the rectus abdominis from rupture of the superior or inferior epigastric artery or their branches, or from a torn muscle. The bleed is limited by the linea alba, the lateral aponeurosis and the tendinous intersections.

Proximal to the arcuate line, the posterior sheath contains the blood and the hematoma stays confined.

Distal to the arcuate line (3 to 6 cm below the umbilicus) there is no posterior sheath, so blood tracks into the prevesical space and the peritoneum, and the inferior epigastric artery is the commoner source.

It accounts for about 2% of acute abdominal pain presentations. It is most frequent in women over 50 (about 3 to 1), reflecting the thinner muscle and the use of anticoagulants. Other risks: antiplatelet agents, hypertension, forceful cough, vomiting, abdominal surgery, injections, pregnancy (third trimester and labor), pregnancy-related strain, hematologic disease and renal failure.

Classification by CT and extent: type I is confined within one muscle (no dissection), type II involves one or both muscles with blood between the muscle and transversalis fascia, type III extends into the prevesical space and peritoneum with hemoperitoneum. Mortality is about 4% overall and up to 25% in anticoagulated patients with type III bleeds.

• Sudden unilateral lower abdominal pain, often after a cough or strain, with a firm tender mass that does not cross the midline
• Fothergill sign: the mass remains palpable when the patient tenses the rectus by raising the head, whereas an intraperitoneal mass becomes impalpable
• Carnett sign: tenderness persists or worsens when the muscle is tensed
• Cullen or Grey Turner bruising after 3 to 5 days
• Tachycardia, hypotension and anemia in type III bleeds
• Red flags: hemodynamic instability, a rapidly growing mass, anticoagulant treatment, and pregnancy with abdominal pain

1. Ultrasound (sensitivity about 80 to 90%): an ovoid, heterogeneous mass within the muscle, rapidly available at the bedside.
2. CT with intravenous contrast is the confirmatory test: attenuation of 50 to 80 HU in acute blood, a fluid-fluid level in older collections, a contrast blush for active extravasation, and the type (extent, hemoperitoneum, pelvic extension).
3. Hemoglobin every 6 hours for 24 hours, platelet count, INR, aPTT, creatinine, group and screen, and anticoagulant levels.
4. Pregnancy test in women of reproductive age.

Differentials: acute appendicitis, incarcerated hernia, ovarian cyst rupture or torsion, diverticulitis, abdominal wall abscess, ectopic pregnancy, placental abruption in late pregnancy, desmoid tumor.

Most cases settle with conservative care.

Conservative (types I and II, stable)

• Admission, bed rest, cold packs for 48 hours, analgesia with paracetamol 1 g orally every 6 hours, and morphine 2.5 to 5 mg IV every 4 hours if needed.
• Stop anticoagulant and antiplatelet drugs. Reverse if bleeding is significant (warfarin: phytomenadione 5 to 10 mg IV slowly and four-factor prothrombin complex concentrate 25 to 50 units/kg IV; heparin: protamine 1 mg for each 100 units given in the previous 2 to 3 hours, maximum 50 mg; dabigatran: idarucizumab 5 g IV; apixaban and rivaroxaban: prothrombin complex concentrate 50 units/kg IV).
• Tranexamic acid 1 g IV over 10 minutes, then 1 g over 8 hours.
• Transfuse red cells when hemoglobin is under 70 g/L (under 80 g/L with cardiac disease) and platelets under 50 × 10^9/L.
• Stop cough with antitussives and treat vomiting with ondansetron 4 mg IV every 8 hours.

Active bleeding or type III: superselective angioembolization of the inferior or superior epigastric artery with coils or particles (success about 90%), then surgery if embolization is unavailable or fails: evacuation of clot, ligation of the vessel and drain. Avoid blind evacuation of a stable hematoma, which reopens tamponade.

Pregnancy: exclude placental abruption by ultrasound, manage conservatively with maternal monitoring, transfuse as needed, and deliver for maternal instability or fetal compromise.

Infected hematoma: drainage with cefazolin 2 g IV every 8 hours and metronidazole 500 mg IV every 8 hours until cultures return.

Restart anticoagulation after 48 to 72 hours of stable hemoglobin (sooner for mechanical valves, with a bridging plan). Ultrasound at 4 to 6 weeks to document resolution, since resorption takes 4 to 12 weeks.

Counsel on avoiding heavy lifting for 6 weeks and on the early symptoms of recurrence.