Rectus Sheath Hematoma 

Updated: Nov 02, 2014
Author: Wan-Tsu Wendy Chang, MD; Chief Editor: Steven C Dronen, MD, FAAEM 

Overview

Background

Rectus sheath hematoma (RSH) (see the image below) is an uncommon and often clinically misdiagnosed cause of abdominal pain. It is the result of bleeding into the rectus sheath from damage to the superior or inferior epigastric arteries or their branches or from a direct tear of the rectus muscle. The emergency physician should be familiar with rectus sheath hematoma because it can mimic almost any abdominal condition. While usually a self-limiting entity, rectus sheath hematoma can cause hypovolemic shock following sufficient expansion, with associated mortality.

Rectus sheath hematoma of the right rectus muscle. Rectus sheath hematoma of the right rectus muscle. Image courtesy of Dr David Gordon.

See Can't-Miss Gastrointestinal Diagnoses, a Critical Images slideshow, to help diagnose the potentially life-threatening conditions that present with gastrointestinal symptoms.

Rectus sheath hematoma is an ancient disorder first being accurately described by Hippocrates and mentioned by Galen. The first reported case in the United States was by Richardson in 1857.

Anatomic features

The best aid to understanding the pathogenesis and making the diagnosis of rectus sheath hematoma is knowledge of the relevant anatomy. The rectus sheath consists of the rectus abdominis muscles, an enveloping fascial sheath, and their blood supply via the epigastric arteries and veins.

The rectus abdominis muscles are two parallel vertically aligned muscles. The rectus abdominis muscles arise from the superior ramus of the pubis and insert into the ventral aspect of the fifth, sixth, and seventh costal cartilages and the xiphoid process. The rectus muscles are separated in the midline by the linea alba. The lateral boundary of the rectus sheath is the linea semilunaris.

The arcuate line is located about 5 cm below the umbilicus and functionally separates the rectus sheath into superior and inferior portions. Above the arcuate line, the aponeuroses of the external oblique, the internal oblique, and the transversalis muscles invest the rectus muscle. Three to four transverse tendinous inscriptions attach the rectus muscle to the enveloping fascia, usually above the arcuate line. The tendinous inscriptions form the typical segmental pattern of the rectus abdominis muscle.

Below the arcuate line, the aponeuroses remain intact anteriorly, but only the weak transversalis fascia and peritoneum separate the muscle mass from the abdominal viscera posteriorly. The inferior retrorectus space communicates with the prevesicular space of Retzius. This communication creates a natural dissection plane between the posterior rectus sheath and the bladder.

 

Anatomy of the rectus sheath. Anatomy of the rectus sheath.

The arterial supply to the rectus sheath is derived from the superior and inferior epigastric arteries. The inferior epigastric artery originates from the external iliac artery. It rises from the inguinal ligament to enter the posterior rectus sheath inferiorly. The inferior epigastric artery then ascends loosely between the rectus abdominis muscle and the posterior rectus sheath. During contractions of the rectus abdominis muscle, the length of the muscle changes, and the artery must glide with the muscle to avoid tearing. The combination of the loose attachment of the inferior epigastric artery with the stabilization of its perforating branches fixed to the muscle belly makes the artery prone to shearing stresses at branching sites during strong muscular contraction.

The superior epigastric artery originates from the external thoracic artery. The superior epigastric artery enters the sheath from behind the seventh costal cartilage and descends between the rectus abdominis muscle and the posterior rectus sheath. The superior and inferior epigastric arteries form rich anastomoses near the level of the umbilicus. The anastomoses are microscopic, helping to diminish the likelihood of trauma to the vessels during muscular contraction.

Pathophysiology

Rectus sheath hematomas (RSHs) are generally caused either by rupture of one of the epigastric arteries or by a muscular tear with shearing of a small vessel. The immediate cause of the rupture may be external trauma to the abdominal wall, iatrogenic trauma from surgery, or excessively vigorous contractions of the rectus muscle. These vigorous contractions are often seen in strenuous exercise or repeated Valsalva maneuvers with severe coughing, vomiting, or straining at the stool. Because the arteries supply the recti posteriorly, most hematomas are posterior to the muscle, making diagnosis by means of palpation more difficult.

Teske's 1946 case series of 100 patients with rectus sheath hematoma showed 60% to be on the right side and more than 80% to be in the lower quadrants.[1] Right-sided hematomas are presumably more common because more people are right handed and, thus, are more prone to right-sided strain of the rectus muscle during strenuous activity. The lower quadrants are more frequently involved because of the long vascular branches that are present and because muscle excursion during contraction with the absence of the tendinous inscriptions is greater.

Hematomas above the arcuate line are generally caused by damage to the superior epigastric artery or its perforating branches. Patients usually present with unilateral, small, spindle-shaped masses because these hematomas are isolated by the rectus sheath and the tendinous inscriptions, causing tamponade of the bleeding.

Hematomas below the arcuate line are caused by damage to the inferior epigastric artery or its perforating branches. They protrude posteriorly and appear spherical because the rectus abdominis muscle is only supported posteriorly by the transversalis fascia and the parietal peritoneum. Below the arcuate line, hematomas bleed more and may dissect extensively because no posterior sheath wall or tendinous inscriptions are present to tamponade the bleeding. Rectus sheath hematomas below the arcuate line are more likely to cross the midline and become bilobar.

Hematomas near the umbilicus are rare. They are small when they do occur because the microscopic anastomoses of the superior and inferior epigastric arteries near the umbilicus do not allow for significant bleeding.

Hematomas near the peritoneum can result in peritoneal irritation, subsequent abdominal rigidity, and gastrointestinal symptoms. Dissection of the hematoma inferiorly into the prevesicular space of Retzius can masquerade as a pelvic tumor or irritate the bladder, resulting in urinary complications.

In 1996, Berna et al used the appearance of rectus sheath hematomas on CT scans to differentiate 3 levels of severity with disposition and therapeutic implications, as follows[2] :

  • Type I: The hematoma is intramuscular, and an increase in the size of the muscle is observed, with an ovoid or fusiform aspect and hyperdense foci or a diffusely increased density. The hematoma is unilateral and does not dissect along the fascial planes. The patient presents with mild-to-moderate abdominal pain and typically does not require hospitalization. Type I hematomas resolve by themselves within 1 month.

  • Type II: The hematoma is intramuscular (mimicking type I) but with blood between the muscle and the transversalis fascia. It may be unilateral but is usually bilateral, and no blood is observed occupying the prevesical space. A fall in hematocrit may be observed. A patient may require hospitalization for close observation, but most do not require transfusions, and most are discharged to home within 3 days. Type II hematomas usually resolve within 2-4 months.

  • Type III: The hematoma may or may not affect the muscle, and blood is observed between the transversalis fascia and the muscle, in the peritoneum, and in the prevesical space. A hematocrit effect can be observed, and, on occasion, hemoperitoneum is produced. These patients are often taking anticoagulation medications and require hospitalization. They often require transfusion and are discharged after 1 week. Only rarely will they develop hemodynamic instability that cannot be controlled with fresh frozen plasma and fluid resuscitation. These unstable patients may require surgical intervention. Type III hematomas usually require more than 3 months to resolve.

After resolution, rectus sheath hematomas usually do not recur and typically do not cause long-term sequelae.

Epidemiology

Frequency

International

Rectus sheath hematoma is an uncommon, but not rare, cause of abdominal pain. In 1999, Klingler et al found an incidence of 1.8% among 1257 patients admitted to the hospital with abdominal pain and undergoing ultrasonography for diagnosis.[3] Anticoagulation is a well-known risk factor. The incidence is thought to be on the rise, with the increased use of oral anticoagulation drugs and low molecular weight heparins (LMWH).

Mortality/Morbidity

Although usually a benign self-limiting condition, rectus sheath hematoma (RSH) may be fatal. Mortality figures are prone to error because of the uncommon incidence of rectus sheath hematoma and the paucity of recent mortality data. Overall, the mortality rate is reported to be 4%. The mortality rate for iatrogenic rectus sheath hematoma is reported to be 18%, whereas the mortality rate for patients with rectus sheath hematoma who are undergoing anticoagulation therapy is reported to be 25%. Pregnant patients have a reported mortality rate of 13%, with a 50% mortality rate for the fetus.

These mortality rates were reported prior to the widespread use of ultrasonography and CT scanning to aid in the early diagnosis of rectus sheath hematoma. Early diagnosis likely reduces the mortality rate, but no studies to date are available to demonstrate this.

The high mortality rate in patients undergoing anticoagulant therapy is related to the larger hematomas as well as the increased age and significant comorbidities of these patients.

The morbidity of rectus sheath hematoma is primarily the result of incorrect diagnosis leading to unnecessary exploratory laparotomy, delay in cessation of anticoagulant therapy, or delay in fluid resuscitation and blood transfusion.

As with other abdominal pathology in the older patient, extra care should be devoted to an expedient and accurate diagnosis in elderly patients. Elderly patients are more likely than younger patients to require aggressive resuscitation, anticoagulation reversal, and admission. For these reasons, elderly patients also experience an increased mortality rate.

Race

Rectus sheath hematoma is reported to occur less often in African Americans, with only 4% of rectus sheath hematomas occurring in people of this race. Whether this low rate is physiologic, a result of sample reporting, or diagnostic bias is unknown.

Sex

Rectus sheath hematoma is 2-3 times more common in females than in males. The higher incidence in women has been attributed to their decreased muscle mass. The sex distribution seems to be equal in younger age groups, although the predisposing factors differ. Pregnancy is a risk factor in younger females, whereas males more commonly develop rectus sheath hematoma after trauma or muscular exertion.

Age

In a 1946 review of 100 cases, Teske reported the occurrence of rectus sheath hematoma in patients aged 4-83 years, with an average age of 47 years.[1] The peak age of incidence is in the fifth decade of life. Incidence increases with age as the protection provided by the rectus sheath becomes compromised by decreased muscle mass. The effects of arteriosclerosis and hypertension also render vessels more susceptible to injury.

 

Presentation

History

Common historical features of rectus sheath hematoma (RSH) include acute abdominal pain, fever, nausea, and vomiting. The nonspecific nature of these symptoms combined with the low incidence of the disorder lead to difficulty in considering this diagnosis. Rectus sheath hematoma should be included in the differential diagnosis of every patient who presents with abdominal pain.

Specific symptoms

Constitutional

Fever and chills are common symptoms in rectus sheath hematoma. Symptoms of hypovolemic shock with weakness, confusion, pallor, and diaphoresis can develop in patients with a large rectus sheath hematoma.

Abdominal pain

The most common presenting symptom is acute abdominal pain. The onset of pain may be sudden, but more often, it develops over a period of several hours. The pain is typically sharp and severe, with an associated palpable abdominal mass. Pain is usually worse with movement and is often unilateral. Constant pain with episodic abdominal cramping is also a frequent symptom. In atypical cases, the pain may develop insidiously, making the abdominal mass difficult to differentiate from an abdominal wall neoplasm.

Gastrointestinal/urologic

Anorexia, nausea, vomiting, diarrhea, constipation, tenesmus, and bladder irritability are all compatible with the diagnosis of rectus sheath hematoma. The severity of symptoms is related to the degree of peritoneal irritation.

Precipitating factors

The clinician needs to have rectus sheath hematoma in the differential, or the diagnosis will be easily overlooked. A careful history should include directed questions regarding surgical procedures, occult blunt trauma, coughing, sneezing, constipation (straining at the stool), or exercise. In patients with certain medical problems, questions about recent asthma exacerbations, bronchitis, or upper respiratory tract infections may prove helpful. Rectus sheath hematoma must always be considered in abdominal pain patients on anticoagulants.

Physical

Vital signs

A low-grade fever is common in rectus sheath hematoma. The hematoma can be large enough to compromise intravascular volume, with resultant signs of hypovolemic shock including hypotension, tachycardia, and tachypnea.

Abdominal examination

Typically, the abdominal examination reveals a palpable, painful, firm, nonpulsatile abdominal mass corresponding to the rectus sheath. The mass may be bilobar with a central groove. The mass does not move with respiration. Because the hematoma is deep to the subcutaneous tissue and rectus muscles, the mass is not always palpable, particularly in obese patients. In 2000, Berna et al's case series reported a palpable mass detected in 8 of 12 patients.[4]

Hyperesthesia of the overlying skin is not uncommon. Bowel sounds may be absent. Signs of local peritoneal irritation with rebound tenderness and involuntary guarding may be present. This finding is most often seen in infra-umbilical hematomas due to the thin transverse fascialis serving as the only barrier between a hematoma and the peritoneum. Rarely, a hematoma may cause extraperitoneal compression of the abdominal cavity and cause abdominal compartment syndrome, or even rupture into the peritoneum, causing a chemical peritonitis.

The Fothergill sign is useful in determining whether an abdominal mass is part of the abdominal wall or whether it is in the abdomen. It is elicited by voluntary contraction of the rectus muscles by the patient lifting either his or her head or legs while in the supine position. With this action, rectus sheath hematomas become fixed, more painful, and more tender, while intra-abdominal masses become less distinct and less tender. The Fothergill sign may be inconclusive in patients who are obese or pregnant. As described by Fothergill in 1926[5] :

This patient complains of pain and the medical man finds the swelling. The trouble is that he seldom knows how long the swelling has been present…The main point is the recognition that these swellings are part and parcel of the abdominal wall. This is generally made by noting that they can still be felt when the recti are in action, and that they become fixed as the muscles contract

The Carnett sign is an additional test to assist in differentiating between abdominal wall and intra-abdominal pathology. It is performed by having the patient lie supine and tensing the abdominal musculature by raising either the head or the shoulder off the table. A positive sign is elicited if abdominal tenderness is increased or unchanged while tensing the abdomen. This indicates an abdominal wall process. A negative sign, or decreased abdominal tenderness while tensing the abdomen, suggests intra-abdominal pathology. Previous studies have demonstrated this sign to be fairly sensitive but not specific for abdominal wall pathology.

The Cullen sign of periumbilical ecchymosis is associated with retroperitoneal or abdominal wall hemorrhage. In rectus sheath hematoma, ecchymosis appears after 2-5 days. The ecchymosis uncommonly extends into the flanks.

See the image below.

The Cullen sign, periumbilical ecchymosis, in a pa The Cullen sign, periumbilical ecchymosis, in a patient with a rectus sheath hematoma.

The Grey-Turner sign is another manifestation of retroperitoneal hemorrhage. This finding of flank ecchymosis was initially described in hemorrhagic pancreatitis, and along with the Cullen sign, it is not specific for retroperitoneal or abdominal wall hemorrhage.

Pelvic examination

The pelvic examination may reveal a mass anterior to the vagina and above the pubis. The pelvic examination may be misleading, particularly in those cases that demonstrate unilateral adnexal tenderness and mass.

Causes

Several risk factors of rectus sheath hematoma (RSH) can be obtained in the history. In most cases of rectus sheath hematoma, one or more precipitating factors can be found. Reports of spontaneous rectus sheath hematoma exist, but more likely, in these cases, the precipitating factor was not appreciated. Anticoagulation is the most frequent predisposing factor, and severe coughing is the most important inciting factor.

Anticoagulation

Rectus sheath hematoma is a well-recognized complication of anticoagulant therapy. Anticoagulation can be a predisposing factor, or it can directly cause rectus sheath hematoma by accidental intramuscular injection of LMWHs. Heparin-induced immune microangiopathy has been proposed as a mechanism of the pathogenetic process. Rectus sheath hematoma secondary to anticoagulation may have greater morbidity and mortality because of increased hemorrhage volume. Even when coagulation factors are within the therapeutic range, a substantial risk of hemorrhage still exists.[6]

Coughing

Rectus sheath hematoma can occur after bouts of severe coughing, explaining its association with asthma, tuberculosis, influenza, pertussis, and other respiratory infections.[6]

Pregnancy

Rectus sheath hematoma is associated with pregnancy in the gravid state, during labor, and in the early postpartum period.

Previous abdominal surgery

Abdominal operations predispose to rectus sheath hematoma because surgical scars redirect the shearing forces on muscle contraction, placing more stress on the epigastric vessels.

Recent abdominal surgery

Excessive retraction or inadequate hemostasis can cause rectus sheath hematoma that may become evident up to 4 weeks after the procedure.

Chronic kidney disease

In a study by Sheth et al involving 115 hospitalized patients with a confirmed diagnosis of rectus sheath hematoma, 58.3% of them had chronic kidney disease of stage 3 or higher.[6]

Steroid/immunosuppressive therapy

In the above-mentioned study by Sheth et al, 41.7% of the patients were undergoing steroid/immunosuppressive treatment.[6]

External trauma

The nature of the trauma can be trivial. Tight contraction of the recti in anticipation of a blow predisposes to rectus sheath hematoma formation.[6]

Vigorous uncoordinated rectus muscle contraction

Rectus sheath hematoma has been observed in a healthy man leaping over a ditch and in a woman rising from a chair to adjust a curtain rod. In a similar manner, sports activities and exercises, such as golf, tennis, skiing, and weight lifting, have caused rectus sheath hematoma. Activities with significant Valsalva effort, such as coughing, sneezing, straining from constipation, urination, and sexual intercourse, have been implicated in rectus sheath hematoma.

General medical conditions

General medical conditions that predispose to rectus sheath hematoma can be categorized as those causing damage to blood vessels; those causing failure of coagulation; or as anomalous conditions, such as endometriosis in the rectus sheath. Vascular conditions of hypertension, arteriosclerosis, and collagen vascular disease are associated with rectus sheath hematoma. Disorders of coagulation associated with RSH include leukemia, myeloproliferative disorders, hemophilia, and blood dyscrasias.

Unusual

Case reports have also described rectus sheath hematoma related to acupuncture and follicle aspiration for in vitro fertilization. Minor surgical procedures such as diagnostic or therapeutic paracentesis have also been shown to cause rectus sheath hematoma.[7] In addition to LMWH injections, rectus sheath hematoma has also been seen in any abdominal wall medication injections (eg, insulin).[8] These unusual causes underscore the importance in obtaining a thorough history from the patient.

 

DDx

Diagnostic Considerations

Important considerations

Recognize, diagnose, and manage rectus sheath hematoma (RSH).

Obtain a surgical consultation for patients with large or expanding hematomas, for patients who are hemodynamically unstable, for those requiring transfusions, or for those undergoing anticoagulation therapy.

Reverse anticoagulation in patients with expanding hematomas, symptomatic anemia, or hemodynamic instability.

Maintain adequate anticoagulation in patients at high risk for intravascular thrombosis with small stable rectus sheath hematomas.

Provide fluid resuscitation and transfusion with packed red blood cells if indicated by hemodynamics, comorbidities, or significant anemia.

Other conditions to consider in patients with suspected rectal sheath hematoma include the following:

  • Intra-abdominal neoplasms

  • Abdominal wall neoplasms

  • Tubo-ovarian abscess

  • Abdominal wall abscess

  • Peptic ulcer disease

  • Perforations

Differential Diagnoses

 

Workup

Approach Considerations

Rectus sheath hematoma is often misdiagnosed. It is important for physicians in primary/emergency medicine and surgery to be familiar with this relatively rare condition, given that misdiagnosis may lead to unnecessary laparotomy or death. Quicker and more accurate diagnosis can lead to a reduction in the mortality rate.[18]

Laboratory Studies

Complete blood cell count

The hematocrit may be normal for small rectus sheath hematomas (RSHs) or significantly depressed with a large hematoma. Serial blood counts may be useful in an expanding hematoma to assess the need for blood transfusion or more aggressive therapeutic measures. The reported white blood cell count ranges from 6.6 X 103 to 29 X 103. As in other acute abdominal disorders, a normal white blood cell count does not rule out rectus sheath hematoma.

Coagulation factors

Although coagulation factors are not helpful for patients on LMWHs, they are useful for patients on oral anticoagulation drugs or for those with a pathologic failure of coagulation. Rectus sheath hematomas are more likely with supratherapeutic anticoagulation, but they can occur in the therapeutic range. Patients undergoing reversal of anticoagulation benefit from serial coagulation factors to assess the response to therapy.

Arterial or venous blood gas

Knowledge of the base deficit from a blood gas level is useful in patients with hypovolemic shock due to rectus sheath hematoma. Serial blood gas levels can be used to guide fluid resuscitation.

Imaging Studies

General

When the history and physical examination findings raise suspicion for rectus sheath hematoma, ultrasonography and CT scanning are commonly used to help confirm the diagnosis. Before the advent of ultrasonography and CT scanning, the correct clinical diagnosis was only made in 17-40% of cases prior to exploratory laparotomy or death.

Ultrasonography

Ultrasonography can be used as a first-line diagnostic test for rectus sheath hematoma, or it can be used to monitor the evolution of a known hematoma. Ultrasonography provides rapid accurate information about the size, the location, and the physical characteristics of the mass. It is safe and well tolerated. It does not expose the patient to radiation or intravenous contrast material. The typical ultrasonographic findings are sufficient to establish the diagnosis.

See the image below.

Ultrasound image of a rectus sheath hematoma prese Ultrasound image of a rectus sheath hematoma presenting as a tender, unilateral abdominal mass. Maharaj D, Ramdass M, Teelucksingh S, Perry A, Naraynsingh V. Rectus sheath haematoma: a new set of diagnostic features. Postgraduate Medical Journal. 2002;78:755-6. Reproduced with permission from the BMJ Publishing Group.

Expected findings

Rectus sheath hematomas are described as spindle shaped on sagittal sections and as ovoid on coronal sections. Usually, the mass is sonolucent, although it may also be heterogenous, depending on the combined presence of clot and fresh blood.[9]

Effectiveness

Ultrasonography has been reported to have a sensitivity of 85-96% in depicting rectus sheath hematoma. However, when it is unsuccessful, it often fails spectacularly, causing undue delay in treatment or unnecessary laparotomy. Zainea's case series of 4 patients in 1988 noted that findings from ultrasonography were misleading in 2 of them. In those 2 patients, the ultrasonographic report described the pathology as occurring within the peritoneal cavity, prompting unnecessary surgical intervention.[10]

Role of ultrasonography

Ultrasonography should be used as a first-line diagnostic test in pediatric patients, pregnant patients, or perhaps in patients with renal insufficiency. However, in other patients, its primary role may be to follow hematomas to maturation and resolution after definitive diagnosis by CT scanning. In patients where the clinician has a moderate-to-high suspicion for rectus sheath hematoma, ultrasonography serves as a viable screening test. Therefore, even if the sonogram demonstrates a mass that is difficult to characterize as intraperitoneal or extraperitoneal, the clinician's pretest probability can help guide therapy. Caution should always be exercised with patients in whom infection or diagnostic uncertainty exists.

CT scanning

CT may be used as a first-line diagnostic procedure in the evaluation for rectus sheath hematoma, or it may follow nondiagnostic ultrasonographic findings. CT permits a precise determination of the location, the size, and the extension of the hematoma. Information is also obtained about the rectus abdominis muscle and the perimuscular tissue. CT may be more appropriate than ultrasonography as a first-line test because it simultaneously aids in the diagnosis of rectus sheath hematoma and rules out other abdominal pathology.

See the images below.

Rectus sheath hematoma of the right rectus muscle. Rectus sheath hematoma of the right rectus muscle. Image courtesy of Dr David Gordon.
Note how the rectus sheath hematoma becomes biloba Note how the rectus sheath hematoma becomes bilobar as it dissects inferiorly (same patient as in the previous image). Image courtesy of Dr David Gordon.

Expected findings

Characteristic findings of acute rectus sheath hematoma on CT include a hyperdense mass posterior to the rectus abdominis muscle with ipsilateral anterolateral muscular enlargement. Chronic rectus sheath hematoma may be isodense or hypodense relative to the surrounding muscle. Above the arcuate line, rectus sheath hematomas have a spindle shape, while those below the arcuate line are typically spherical.[11]

Effectiveness

CT scanning is 100% sensitive and 100% specific in acute rectus sheath hematoma of less than 5 days' duration. After 5 days, MRI may be required to differentiate hematomas from tumors of the abdominal wall.

Types of rectus sheath hematoma on CT scanning

In 1996, Berna used the appearance of rectus sheath hematomas on CT scans to differentiate 3 levels of severity with disposition and therapeutic implications.[2]

  • Type I: The hematoma is intramuscular, and an increase in the size of the muscle is observed, with an ovoid or fusiform aspect and hyperdense foci or a diffusely increased density. The hematoma is unilateral and does not dissect along the fascial planes.

  • Type II: The hematoma is intramuscular (mimicking type I) but with blood between the muscle and the transversalis fascia. It may be unilateral or bilateral, and no blood is observed occupying the prevesical space. A fall in hematocrit may be observed.

  • Type III: The hematoma may or may not affect the muscle, and blood is observed between the transversalis fascia and the muscle, in the peritoneum, and in the prevesical space. A hematocrit effect can be observed, and on occasion, hemoperitoneum is produced.

Role of CT

CT is the diagnostic test of choice for rectus sheath hematoma and is superior to ultrasonography in sensitivity and specificity. Patients who are pediatric, pregnant, or have renal insufficiency may benefit from ultrasonography as a first-line test to avoid radiation and intravenous contrast material. In patients with renal insufficiency, a noncontrast CT scan can be used and will still show the typical findings of rectus sheath hematoma, although the ability to find active extravasation or to rule out other abdominal pathology is limited.

MRI

MRI is useful in differentiating chronic rectus sheath hematoma from other anterior abdominal wall masses when CT findings are not specific. Chronic rectus sheath hematoma is demonstrated as high signal intensity on both T1- and T2-weighted images up to 10 months following the onset of the hematoma. In acute rectus sheath hematoma of less than 48 hours' duration, the MRI of rectus sheath hematoma does not reveal high signal intensity and is not useful in the diagnosis.[12] Many clinicians will be limited by the availability of MRI in their practices, particularly when other types of imaging studies are readily available.

Radiography

Plain anteroposterior (AP) and erect radiography of the abdomen

Plain AP radiographs are not useful in diagnosing rectus sheath hematoma, but they may help in ruling out other diagnostic possibilities if no free air, obstructive gas pattern, sentinel loop, appendicolith, or other findings are noted.

Lateral decubitus radiography

Lateral decubitus radiography is only of historical interest in diagnosing rectus sheath hematoma. In 1967, Herzan described a rectus sheath hematoma on a lateral decubitus radiograph as a placenta-shaped or ovoid spindle-shaped mass in the anterior abdominal wall or as a widening of the rectus sheath.[13]

Scintigraphy

A solitary case report by Monsein and Davis in 1990 describes the use of this diagnostic modality in rectus sheath hematoma.[14] Following positive evaluation by CT scanning of a large mass in the anterior abdominal wall, scintigraphy with technetium-99m–tagged red blood cells depicted several sites of bleeding corresponding to previous insulin injection sites. This bleeding was not observed with angiography. The inferior epigastric artery was embolized with Gelfoam despite an absence of bleeding on angiography with subsequent hematocrit stabilization. Therefore, scintigraphy can be used after a diagnosis of rectus sheath hematoma by CT to show active extravasation not detectable by angiography.

Cystography

Cystography should not be used to diagnose rectus sheath hematoma when the condition is suspected. However, a patient with primarily bladder symptoms may undergo diagnostic cystography. Rectus sheath hematoma can be observed as an indentation of the dome of the bladder, which can be mistaken for a pelvic tumor but is caused by dissection of the rectus sheath hematoma into the prevesicular space of Retzius.

Intravenous pyelography (IVP)

IVP should not be used to diagnose rectus sheath hematoma when the condition is suspected. However, patients with rectus sheath hematoma and significant dissection into the space of Retzius may present with an obstructive pattern of renal failure. Patients with obstructive renal failure who undergo IVP can show bilateral hydronephrosis if the rectus sheath hematoma significantly displaces the bladder.

Other Tests

Intraluminal bladder pressure measurement: Measuring intra-abdominal pressure by using indwelling catheter manometry of the bladder may be considered if there is clinical suspicion of abdominal compartment syndrome. Clinical signs of abdominal compartment syndrome include oliguria, decreased cardiac output, alterations in minute ventilation, intracranial hypertension, and altered splanchnic blood flow. Case reports describe abdominal compartment syndrome from extraperitoneal compression of the abdominal cavity by a rectus sheath hematoma; however, the incidence of abdominal compartment syndrome in rectus sheath hematoma is unknown.[15]

Procedures

Needle aspiration

Needle aspiration of rectus sheath hematoma has occasionally been advocated to differentiate rectus sheath hematoma from an abscess and to decrease the duration of symptoms by the removal of the irritating mass. However, most sources consider needle aspiration unwise because of the risk of bacterial contamination and the possibility of bowel perforation if the mass is a hernia sac instead of a hematoma. Also, aspiration of clotted blood is difficult and likely to be unsuccessful. Some sources recommend needle aspiration under ultrasonographic guidance, although this technique still carries the risk of bacterial contamination. One case of hematoma recurrence has been reported following needle aspiration.

 

Treatment

Emergency Department Care

Once rectus sheath hematoma (RSH) is diagnosed, the patient's clinical condition determines appropriate treatment and disposition. Treatment may be either conservative or invasive.

Conservative treatment is appropriate for patients who are hemodynamically stable and have small nonexpanding hematomas in which symptoms are mild and the diagnosis is certain. Conservative treatment of rectus sheath hematoma includes rest; analgesics; hematoma compression; ice packs; treatment of predisposing conditions; and if necessary, more aggressive therapies of intravenous fluid resuscitation, reversal of anticoagulation, and transfusion. Care must be taken in applying a conservative approach because even a relatively small hematoma has been reported to cause hypotension and death in a patient who is debilitated.

Conversely, in 2000, Berna et al's case series of 12 patients with rectus sheath hematoma who were all undergoing anticoagulant therapy and treated conservatively had no reported mortality even though 7 of the patients initially had hemodynamic instability and anemia. These patients demonstrated improvement in their general condition 3-5 days after diagnosis.[4] In a retrospective study of 7 patients who had been diagnosed with rectus sheath hematoma, Anyfantakis et al found that management was mostly conservative (85.7%) with disruption of anticoagulation, analgesia, and bed rest. Most patients (85.7%) had an uncomplicated clinical recovery and were discharged home after a mean hospital stay of 10 days. The investigators concluded that prompt recognition of rectus sheath hematoma will prevent needless surgical intervention and potential complications.[17]

Anticoagulation reversal

Patients who are undergoing invasive procedures and those with hemodynamic instability, expanding hematomas, or symptomatic anemia should be considered for anticoagulation reversal. For patients taking oral anticoagulation, reversal can be achieved with phytonadione plus fresh frozen plasma (FFP). The patient's clinical condition determines the aggressiveness of anticoagulation reversal.

Intravenous phytonadione can be administered at a dose of 1-10 mg. Intravenous phytonadione is associated with rare but well-documented cases of anaphylactoid reactions; thus, it must be administered with care at a rate no greater than 1 mg/min, with frequent (every 15 min, 30 min, and 1 h) vital sign measurements. A patient given a dose of 10 mg of intravenous phytonadione may be refractory to Coumadin for several weeks, making 2.5 mg or 5 mg a better dose in all but the most severe RSHs.

Subcutaneous phytonadione is associated with an unpredictable therapeutic response and is not recommended.

Oral phytonadione has a time to onset that is too slow for a patient who is actively bleeding.

FFP is administered in a volume of 15 mL/kg and provides coagulation factors for as long as 8 hours. FFP may have to be administered with diuretics if volume overload is a concern.

Patients on heparin can have coagulation reversed by protamine at a dose of 1 mg per 100 U of heparin. Heparin has a half-life of 60 minutes. A dose of protamine reverses all of the heparin administered in the past hour, one half of the heparin of the previous hour, and one fourth of the heparin given 2 hours previously, assuming that no recent bolus has been administered.

Patients on LMWHs can have their anticoagulation partially reversed by protamine, although refractory heparinoid fractions are present.

Transfusion

The decision to transfuse is made depending on the patient's need for fluid resuscitation; the presence of comorbid conditions, such as active coronary ischemia; the degree of anemia; and the need for an operative procedure for control of bleeding. In 1988, Zainea reported the transfusion of blood in 4 of 8 patients in a case series, although none of the patients were hemodynamically unstable.[10] In Berna's case series of 12 anticoagulated patients in 2000, all 5 patients with type III hematomas required transfusion and had alterations in hemodynamic variables.[4] Transfusion requirements are generally 2-6 U of packed red blood cells.

Two main modalities exist for invasive control of active bleeding in rectus sheath hematoma: (1) therapeutic angiography with embolization of the bleeding vessel and (2) operative therapy with clot evacuation, ligation of bleeding vessels, and closed-suction drainage. Invasive treatment should be considered in patients with enlarging hematomas, hemodynamic instability unresponsive to fluid resuscitation, peritoneal signs, pain not well controlled with analgesics, and persistent gastrointestinal or urinary symptoms. Patients with significant comorbidities may not be candidates for invasive therapy.

Arterial embolization

In 1980, Levy first described the transcatheter Gelfoam embolization technique in the treatment of rectus sheath hematoma.[16] This invasive therapy can produce hemostasis, reduce the size of the hematoma, decrease the need for blood product transfusion, and prevent rupture into the abdomen. Embolization with thrombin, Gelfoam, or coil is an alternative to surgery for conditions not responding to conservative management.

Operative exploration

Surgical treatment includes evacuation of the hematoma, ligation of bleeding vessels, repair of the rectus sheath, drainage (when indicated), and closure of the abdominal wall. Recurrences following surgical therapy have not been reported.

The decision to admit a patient with rectus sheath hematoma depends on the clinical data regarding hemodynamic status and comorbid conditions as well as the size of the hematoma. Patients on anticoagulation therapy should be admitted to ensure that the hematoma is not expanding and to plan restarting anticoagulation as appropriate. In general, patients with type I hematomas do not require hospitalization. Patients with type II and type III hematomas usually do require hospitalization. Patients with type II hematomas can be admitted to the floor during the first 24-48 hours to evaluate evolution of the hematoma. Patients with type III hematomas often present with hemodynamic instability requiring fluid resuscitation and blood transfusion that is best managed in the intensive care unit setting.

Postdischarge care includes rest, analgesics, hematoma compression, ice packs, and treatment of predisposing conditions. Type I hematomas resolve after approximately 1 month. Type II hematomas require 2-4 months, and type III hematomas require more than 3 months and as long as a year for complete resolution.

Consultations

All patients who are admitted for rectus sheath hematoma (RSH) should have a surgical consultation, either general or vascular, depending on the institution. The diagnosing clinician should also consider surgical or primary care consultation for discharged patients and provide follow-up evaluation and long-term pain control.

 

Medication

Medication Summary

The goals of pharmacotherapy are to reduce morbidity and to prevent complications.

Anticoagulation reversal agents

Class Summary

Patients on warfarin can have their anticoagulation reversed with phytonadione.

Phytonadione (Mephyton, Konakion, AquaMEPHYTON)

Vitamin K is a necessary cofactor for gamma carboxylation in the synthesis of factors II, VII, IX, and X in the liver. Used therapeutically in RSH to treat warfarin-induced hypoprothrombinemia.

Protamine

Protamine forms a complex with heparin to create a nonreactive salt. Heparin is neutralized within 5 min of protamine administration. The duration of effect is 2 h. The half-life of protamine is less than heparin; therefore, multiple dosing may be required. LMWHs can be partially reversed with protamine.

The half-life of heparin is 60 min. Therefore, enough protamine should be administered to reverse all of the heparin administered in the last 30 min, one half of the heparin administered the previous hour, and one fourth of the heparin administered the hour before that, assuming no recent bolus.

Analgesia

Class Summary

RSHs are very painful conditions that often mimic or present as an acute abdomen. The clinician should have a low threshold for narcotic analgesia. The clinician should also recognize the theoretic complication of platelet inhibition with nonsteroidal anti-inflammatory analgesics.

Hydrocodone and acetaminophen (Lorcet-HD, Vicodin, Lortab)

Drug combination indicated for moderate to severe pain.

Oxycodone and acetaminophen (Percocet, Roxicet, Roxilox, Tylox)

Drug combination indicated for the relief of moderate to severe pain.

 

Follow-up

Further Outpatient Care

Patients should be educated regarding the expected duration of symptoms related to the type of rectus sheath hematoma (RSH) present. This will provide reasonable expectations related to need for pain control and work limitations. Patients can follow up with their primary care physicians or surgeons for pain control as the hematoma resolves.

For patient education resources, see Digestive Disorders Center and Skin Conditions and Beauty Center, as well as Abdominal Pain in Adults and Bruises.

Transfer

Transfer of patients with rectus sheath hematoma is rare but may be appropriate in smaller hospitals without intensive care capabilities when treating patients that are hemodynamically unstable. The transferring physician should contact an accepting surgeon while continuing aggressive resuscitation. Patients with types I and II rectus sheath hematomas typically should not require transfer.