Introduction
Spontaneous inferior epigastric artery hemorrhage (SIEAH) is a rare condition and can lead to rectus sheath hematoma (RSH), and may thus prove potentially fatal condition (1-5). Bleeding can lead to hematoma and tamponade; therefore, this episode may be self-limited (2,6-8). However, in some cases, hemorrhaging can result in hypovolemic shock or even death. Anticoagulant therapy has been reported to be a risk factor of mortality (1,3,4). Other risk factors of SIEAH include hypertension, pregnancy, atherosclerosis, obesity, the use of corticosteroids, thrombophilia and leukemia (1,5,8). Initially, conservative treatment, including blood transfusion, anticoagulation therapy and coagulation parameter correction, is the most commonly used treatment (1,2,4,9,10). However, in some patients with an unstable hemodynamic status, invasive intervention is indicated (2,4,9,10). In some selected cases, compared with open surgery, transcatheter arterial embolization (TAE) can be a relatively safe and effective modality for the termination of bleeding (2,9,10). The present study describes two cases that underwent anticoagulant therapy and developed spontaneous inferior epigastric artery (IEA) bleeding. Both cases were successfully dealt with using TAE.
Discussion
RSH accounts for 1-2% of acute abdominal syndrome cases (2,5,8,11). Although its incidence is rare, certain studies have reported a high mortality rate of up to 25% with anticoagulant therapy (2,4,11,12). The etiology of RSH includes trauma, intensive muscle contractions, and iatrogenic and anticoagulant therapy (2,3,5,12,13). Anticoagulant therapy is one of the major risk factors of RSH (14). In a previous study, Cherry and Mueller reviewed 126 RSH cases and found that 25% of the patients received anticoagulant therapy (14). SIEAH is a relatively rare condition of RSH (2,5). The pathophysiology of SIEAH remains unclear. One hypothesis is unrecognized minor trauma, such as cough, sneezing, or passive joint motion (8,9,11). Patients with an advanced age are more susceptible to suffering from SIEAH. The cause may be rectus sheath weakness or small vessel atherosclerosis, or both (8,9,12,13). Nevertheless, anticoagulant therapy is strongly associated with SIEAH (5,8,11,13).
IEA pseudoaneurysm rupture is also a rare etiology of RSH (15-17). The majority of cases of IEA pseudoaneurysm rupture are iatrogenic, such as the extraction of the retention suture, surgical trauma, drain tube insertion or removal, and therapeutic paracentesis (15,16). Color Doppler sonography can present ‘to-and-fro’ flow (16). CT and angiography can also reveal pseudoaneurysm and bleeding (15-17). In the present study, in case 1, the patient exhibited RSH on post-operative day 10. Moreover, the left para-midline incision wound was just beyond the extravasation point (Fig. 1A). Therefore, iatrogenic IEA pseudoaneurysm rupture can be a possible cause of RSH. However, angiography revealed no signs of pseudoaneurysm, only contrast extravasation. Thus, it was considered that the bleeding episode was SIEAH related to anticoagulant therapy.
The most common presentation of SIEAH is abdominal pain (2,8,11,12), which can become aggravated with the patient’s movements (2,3,5,8). The typical finding during physical examination is an abdominal mass, which does not cross the middle abdomen (2,3,5,7,8). Peritoneal signs, such as muscle guarding or rebounding pain, may be positive; therefore, the presentation can mimic that of acute abdominal syndrome (3,7,8,11,12). Laboratory data may reveal normal coagulation function even with active bleeding (2,11). Bedside sonography can provide some information on differential diagnosis; however, CT is the most effective imaging modality (5,12). Both sensitivity and specificity can reach 100% (2,3,5,11,12).
Since hematoma caused by SIEAH is confined to the rectus sheath, bleeding can be self-limited. Thus, conservative treatment with compression, the use of ice packs and blood transfusion should be the appropriate initial treatments (2,3,5,12,13). Invasive management, such as surgical intervention with hematoma removal and ligation of the bleeding vessel, has been the most standard treatment, particularly for correcting hemodynamic instability (2,3,5,7,12). However, locating the bleeding point in hematoma and muscle fiber is difficult (9,10). Moreover, releasing the pressure of hematoma may aggravate bleeding (9). In patients with severe comorbidities, old age, or other associated injuries, the surgical intervention may result in several complications. Hence, in some selected cases, a minimally invasive procedure, such as TAE, may be the choice of treatment for SIEAH (3,7,8,11). Some studies have suggested that the shock status, such as hypotension and tachycardia, is not a contraindication of TAE (3,10). If the diagnosis of SIEAH is definite, embolization can be performed to achieve hemostasis (3,8,10,11).
In patients with SIEAH with unstable hemodynamic status, to date, data suggesting that TAE is more suitable than traditional open surgery are lacking (10,12). However, it is suggested that with the improvement of the imaging system and equipment, for selected patients with anticoagulant therapy, TAE may be the optimal treatment, as with Case 1 in the present study, for example. In a patient with old age and acute myocardial infarction, TAE may be superior to open surgery as the initial treatment.
In conclusion, the standard use of anticoagulant or antiplatelet agents may induce severe bleeding episodes, such as SIEAH. Although the condition is rare, it can be potentially life-threatening. The diagnosis is mainly dependent on CT findings. Surgery is a feasible treatment; however, it has some limitations. In some selected patients receiving anticoagulant therapy, TAE, as a minimally invasive procedure, may be the preferred treatment for SIEAH.