Spontaneous hematoma of the rectus abdominal wall in pregnancy

Introduction

Rectus sheath hematoma (RSH) is a well-described entity with a reported incidence of misdiagnosis as high as 93% [4]. It is the result of bleeding into the rectus sheath from damage of the superior or inferior epigastric arteries or their branches. During pregnancy, RSH is rare and there are not many cases described in the literature at present.

Case report

A 42-year-old woman, gravida 11, para 10, came to hospital in the 34th week of gestation because of fetal intrauterine demise and abdominal pain exacerbated by movement. She denied any trauma or coughing. She also denied any trauma during work or domestic violence. The pregnancy had been uneventful until that moment. Physical examination result was within normal limits, vital signs were stable and blood pressure was normal. Abdominal examination revealed a tender abdomen in the right lower quadrant. There were moderate rigidity and tenderness along the whole length of the right rectus. Examination revealed a tender mass in the right quadrant, the presence of which was exaggerated on elevation of the head. The tenderness was increased by contraction of the rectus muscle. Blue staining of the abdomen appeared 24 h after admission. It measured 10 cm at the beginning but then progressively engulfed the whole abdomen. Ultrasound confirmed fetal demise and showed a well-delineated mass of size 18×10 cm, diagnosed as an ovarian tumor or a degenerating myoma. Because of this dilemma, a magnetic resonance imaging (MRI) was scheduled. MRI showed a large RSH of size 16×12×8 cm (Figures 1 and 2).

Figure 1

MRI scan of the rectus abdominis hematoma (black arrows) – transverse plane.

Figure 2

MRI scan of the rectus abdominis hematoma (black arrows) – coronal plane.

Laboratory investigations revealed a moderate anemia: hematocrit (Ht), 31.2%; hemoglobin (Hb), 10.8 g/dL; fibrinogen, 1.47 g/L; platelets, 209,000/mm³; international normalized ratio (INR), 1.01; activated partial thromboplastin time (APTT), 22.8 s; leukocyte count, normal; urine protein level, normal. The Hb level had dropped to 8.4 g/dL in 3 days and the coagulation profile was checked again: fibrinogen, 2.49 g/L; platelets, 196,000/mm³; INR, 0.95; APTT, 35.5 s. She delivered after induction with misoprostol a 2700-g baby without malformations. On the first day postpartum, the Hb level was 7.6 g/dL and Ht level was 22.8%. She was hemodynamically stable, and the RHS was treated in a conservative manner with analgesics and local treatment with heparin (heparin ointment). After delivery, she received parenteral iron infusions and her Hb level increased to 9.4 g/dL on the 7th day postpartum. We preferred the use of intravenous iron to oral treatment, because it is a safer alternative with regard to patient compliance. She came back after 40 days and the hematoma was still present but smaller (10 cm), and after a 6-month interval the ultrasound revealed no hematoma. The patient recovered uneventfully.

Discussion

Rectus sheath hematoma (RSH) is an anciently reported disorder, being described by Hippocrates according to Payne [7]. During pregnancy, RSH is rare and there are not many cases described in the literature at present. A PubMed search of the English language medical literature using the terms “rectus sheath hematoma” or “rectus abdominis” and pregancy found only 12 reported cases begining in 1990. We chose this period because data became more available after 1990. RSH in pregnancy is more common in multiparous women [6]. Diagnosis of RSH can be difficult as proven by the high rate of misdiagnosis [8, 9]. In pregnancy, RSH has been misdiagnosed as uterine rupture, placental abruption, ovarian torsion and degenerating uterine leiomyomas. An incorrect initial diagnosis is associated with increased rates of exploratory laparotomy, cesarean delivery, premature delivery and perinatal death [5]. Although it is a very rare entity, RSH should be included in the differential diagnosis of every pregnant patient who presents with abdominal pain. Usually, a hematoma within the rectussheath produces a painful, tender swelling that can mimic anintraperitoneal mass with features of an acute abdomen. Because the arteries supply the rectus muscle posteriorly, most hematomas are posterior to the muscle, making diagnosis by means of palpation more difficult [3]. The Carnett sign is an additional test to assist in differentiating between abdominal wall and intra-abdominal pathology. If the abdominal tenderness is unchanged or increased when the abdominal wall is tensed, this indicates an abdominal wall process. The Fothergill sign, an important examination finding, is elicited by having the patient raise her head while in a supine position; an intra-abdominal mass will become impalpable, while the abdominal wall mass will become fixed and palpable. A tender mass that does not disappear during the contraction of the rectus muscle is an indication of RSH. The Cullen sign of periumbilical ecchymosis is associated with retroperitoneal or abdominal wall hemorrhage. In RSH, the ecchymosis appears after 2–5 days. The ecchymosis uncommonly extends to the flanks.

When the history and physical examination findings raise suspicion for RSH, ultrasonography and MRI are commonly used to help confirm the diagnosis. Ultrasonography provides rapid and accurate information about the size, the location and the physical characteristics of the mass [1]. MRI is useful in differentiating chronic RSH from other anterior abdominal wall masses. Computed tomography (CT) allows a precise determination of the location, size and extension of the hematoma. In 1996, Berna etal. [2] used the appearance of RSHs on CT scans to differentiate three levels of severity with disposition and therapeutic implications. Type I RSH is unilateral hematoma contained within the muscles. Type II RSH is a bilateral hematoma or hematoma not contained within the muscle sheath. Type III RSH invades the pre-vesicular space or peritoneum [2].

Conservative treatment is appropriate for patients who are hemodynamically stable and have non-expanding hematomas in which symptoms are mild and the diagnosis is certain [3, 9]. Conservative treatment of RSH includes rest, analgesics, hematoma compression, ice packs and, if necessary, more aggressive therapies of intravenous fluid resuscitation and transfusion. In pregnant patients, nonsurgical management is preferred [3, 9]. The indications for surgery are as follows: rupture of the hematoma into the peritoneum, infection or if the patient is hemodynamically unstable and unresponsive to initial fluid resuscitation. Surgical treatment consists in clot evacuation, ligation of bleeding vessels, and closed-suction drainage. Percutaneous management by selective transcatheter arterial embolization may also be a therapeutic option [9]. Cesarean delivery is performed for fetal indications. RSH has been associated with a 50% rate of fetal demise as in our case. The cause of the fetal demise could be represented by the acute blood loss or by a mechanism of vasoconstriction that could follow the blood loss.

Conclusion

RSH is an unusual cause of a painful abdominal mass that may be present during pregnancy. A careful history and a high degree of suspicion when performing pelvic ultrasound examination will assist in making the correct diagnosis. In difficult cases, MRI can be useful for a correct diagnosis. A conservative management proves to be beneficial if the patient is hemodynamically stable.