What is Retroperitoneal Hematoma?
Retroperitoneal hematoma, or bleeding behind the abdominal cavity, can often go unnoticed and is a cause of serious health issues and even death. This condition can often be hard to spot because clear signs and symptoms may not show up until a significant amount of blood has been lost. Often, when this condition is recognized, patients may be in a state of hemorrhagic shock or a condition caused by severe blood loss.
There’s a way to categorize the space where this bleeding occurs into three areas. The central-middle area (zone 1) is located between two muscles in our lower back and includes the abdominal aorta, the main blood vessel supplying blood to the body, inferior vena cava, another significant vein, pancreas, and midline duodenal structures, parts of your upper digestive tract. The area around the kidneys (zone 2) begins at the sides of the same muscles in the lower back and contains the kidneys, ureters, and parts of the colon. The pelvic zone (zone 3) comprises the bladder and many blood vessels, including a rich network for veins at the base of the spine. This space also includes important structures like other muscles, the spine, and houses connections to the diaphragm and pelvic bone.
The conditions leading to retroperitoneal bleeding are usually grouped into traumatic (caused by injury), like penetrating or blunt trauma, and nontraumatic, which can occur spontaneously or as a result of a medical procedure. Diagnosing retroperitoneal hematoma can be challenging because symptoms can vary and are often nonspecific. It requires thorough patient history and physical examination with a high level of suspicion for it. What signs or symptoms will be present depend largely on which organs are affected. The physical examination should start with an assessment of the airway, breathing, and blood circulation following standard protocols for severe trauma management. Most often, the condition’s diagnosis relies on a computerized tomography (CT) scan, which may also identify what caused the bleeding. Treatment can include observation, a procedure in which a small coil is inserted to stop the bleeding, embolization, a non-surgical procedure that blocks blood vessels, and emergency surgery for unstable patients.
What Causes Retroperitoneal Hematoma?
A retroperitoneal hematoma is a type of internal bleeding that occurs in the retroperitoneum, the space behind the abdominal cavity and near the kidneys. This condition can happen because of an injury or due to a spontaneous or medical-related reason.
Most of the retroperitoneal hematomas are caused by blunt trauma, which happens when external force is exerted on the body. It can crush and rip tissues and blood vessels, occurring frequently in car accidents like injuries to the kidney area, the pancreas, blood vessels in the pelvis due to fractures, and blood vessels in the retroperitoneum.
Sometimes, retroperitoneal hematoma can also occur due to penetrating trauma, such as gunshot wounds or stabbings. The kind of injury depends on the path of the penetrating object and usually results in it affecting other parts of the abdomen too.
There are also non-injury related cases of retroperitoneal hematomas. For example, it can occur iatrogenically, which means they can be caused by medical procedures such as percutaneous interventions or endovascular procedures. Although it’s not very common, when it does occur, it can cause serious complications and increase the risk of death.
The frequency of this type of hematoma is also decreasing in recent years. However, some patients have a higher risk, like those who have been pierced for medical procedures above the groin, women,and patients on certain medications like GPIIb/IIIa inhibitors or warfarin, a blood thinner.
Spontaneous retroperitoneal hematoma occurs without any obvious cause and is very rare. It’s usually seen in older adults, patients on anticoagulants (blood-thinning medicines), and those with a blood clotting disorder. They could also be related to illnesses such as COVID-19. In some cases, underlying causes can include ruptures of tumors like angiomyolipomas, cysts, or renal carcinomas (a type of kidney cancer). Sometimes, vascular malformations, such as aneurysm or pseudoaneurysm in any of the blood vessels in the retroperitoneum can also be the cause.
Risk Factors and Frequency for Retroperitoneal Hematoma
Retroperitoneal hematoma, which is related to injuries in the area at the back of the abdomen, is a condition that varies greatly in how often it occurs. This condition often occurs from either blunt injuries (67% to 80% of cases) or penetrating trauma (20% to 33% of cases). In one study, it was found in 12% of stable patients who had abdominal trauma. Most of these patients had kidney injuries, which make up to 10% of all blunt abdominal traumas.
When it comes to injuries related to blood vessels, these are found more commonly in patients with injuries from sharp objects rather than blunt forces. Severe injuries involving blood vessels are rare in blunt force trauma patients but can lead to central retroperitoneal hematomas. Pelvic fractures, which account for about 2% to 8% of all fractures, can cause serious bleeding and have very high death rates. According to one study, the death rate for patients undergoing a procedure to stop pelvic bleeding was 17.6%, compared to a group that didn’t have the procedure, where the death rate was 32.6%. Injuries to organs in the retroperitoneal space are relatively rare, occurring in 0.2% and 5% of cases. However, when these injuries do happen, they have high death rates of more than 20%.
In cases of non-traumatic retroperitoneal hematoma, the cause can either be spontaneous or due to complications from certain procedures, like going through the skin with a needle. There has been a drop in retroperitoneal hematomas associated with heart catheterization. However, even with the decrease, a small number of patients still developed a retroperitoneal hematoma. Patients with this condition are significantly more likely to die, with a risk level 3.59 times higher, and experience negative heart events, with a risk level 5.76 times higher.
Spontaneous retroperitoneal hematoma is very rare, occurring in about 0.6% of cases. The exact rate is hard to pin down due to its rarity and the broad range of symptoms and causes. One study found only 89 patients over 7 years, with a death rate of 5.6% in the first week and 19.1% after 6 months. Around 40% needed intensive care unit monitoring. Another study found a 6% death rate directly attributed to retroperitoneal hematoma, but the overall death rate was 20%, suggesting that retroperitoneal hematoma is more common in older adults.
Signs and Symptoms of Retroperitoneal Hematoma
Retroperitoneal hematoma is a condition which requires high suspicion and a thorough medical examination to diagnose correctly. It usually depends on which organs are injured. For people with trauma, doctors need to take a comprehensive understanding of the injury mechanism to identify potential problems. They may experience pain in the abdomen, flank or back which could signal a retroperitoneal hematoma. However, these symptoms might also indicate other types of injuries like abdominal or musculoskeletal injuries.
Doctors need to ensure they rule out other possibilities and consider retroperitoneal hematoma even though there aren’t any reliable symptoms to confirm the diagnosis. When examining the patient, doctors will follow the Advanced Trauma Life Support protocol, checking the airway, breathing, and circulation first, and addressing any immediate life-threatening conditions. Certain physical signs could suggest particular injuries, for example, an unstable pelvis could indicate a pelvic retroperitoneal hematoma, while injuries to the back or flank might suggest major blood vessel or kidney damage.
- Unstable pelvis
- Flank or back injuries
If a patient is in trauma and there’s no clear source of blood loss, doctors should suspect hemorrhage (bleeding) as the primary cause of low blood pressure. Clinical history, mechanism of injury, and physical exam findings can guide doctors to help identify hidden bleeding sources. Retroperitoneal bleeding should be considered in such cases.
Spontaneous retroperitoneal hematomas don’t have specific signs and symptoms. Often, the most common complaint, experienced by 46% to 67.5% of patients, is abdominal pain. Other symptoms might include back, flank, and hip pain. Some patients might show signs of hypovolemia (loss of blood or other body fluids) due to continuous blood loss from the hematoma; these include rapid heartbeat, low blood pressure, and poor blood flow to the body’s tissues.
- Abdominal pain
- Back pain
- Flank pain
- Hip pain
- Rapid heartbeat
- Low blood pressure
- Poor blood flow to the body’s tissues
Abdominal tenderness may sometimes be present. However, some signs like flank bruising are not frequently seen, making diagnosis difficult. When patients have a retroperitoneal hematoma after undergoing a certain medical procedure like a percutaneous coronary intervention, they may experience similar symptoms including abdominal, flank, and back pain. Other noticeable signs may include tenderness and swelling in the groin area after the femoral approach, and femoral neuropathy which is probably due to the nerve being compressed by the hematoma.
Testing for Retroperitoneal Hematoma
When it comes to diagnosing retroperitoneal hematomas, which are a collection of blood that accumulates in the back of the abdomen, it can be quite difficult to identify simply through examining your physical symptoms. This is because the symptoms are usually hidden or unclear. That’s why doctors tend to use imaging studies to detect them more accurately. These can include plain films (similar to X-rays) or ultrasonography, which uses sound waves to create images. However, these can still be misleading. Therefore, the most reliable way to diagnose a retroperitoneal hematoma is through a technique called a contrast-enhanced computed tomography (CT) scan. This is a specialized type of X-ray process which provides detailed images of your body’s tissues and structures. If you’re a patient who has suffered from significant trauma, your doctor is likely to use a CT scan as part of your overall assessment. This method is considered extremely sensitive, nearly 100% reliable in uncovering any hidden retroperitoneal hematoma.
Although ultrasonography is often used in trauma exams at the bedside, it’s generally not trusted for detecting a retroperitoneal hematoma.
If you haven’t suffered from any trauma, diagnosing a retroperitoneal hematoma can be more difficult. In these cases, a CT scan can still help by pinpointing the position and size of the hematoma, which is crucial information for treatment planning. If during the CT scan, the contrast medium (a special dye used to make structures more visible) begins to leak out of your blood vessels, it may suggest the need for an intervention, either through radiology or surgery.
In addition to imaging studies, your doctor may also require laboratory tests to evaluate your condition. This could include tests to check your blood count, to determine if you are anemic; a comprehensive metabolic panel to see if there are any abnormalities in your kidney function or electrolytes; liver function tests to check for any liver issues; and coagulation studies – these are to calculate your bleeding risk and if your blood is clotting normally, especially if you are taking medication that prevents blood clotting. They may also type and screen your blood in preparation for transfusion, if it’s needed.
If your injury involves trauma to the abdomen and your pancreas is affected, a laboratory test may show an increase in your serum amylase. This is a substance produced by your pancreas and its levels may rise if the pancreas is injured. Finally, in case of any blunt trauma, your doctor may check your urine for the presence of blood – this is because blood in your urine may be a sign of an injury to your kidney.
Treatment Options for Retroperitoneal Hematoma
Managing retroperitoneal hematomas, or blood clots that form behind the abdominal cavity, involves using various treatments depending on the patient’s condition, the cause of the problem, and the patient’s general health. The treatment options include monitoring the condition closely for stable patients, using a technique called angioembolization or surgery for unstable patients. All treatments aim to replace lost blood and stop bleeding according to standard procedures.
In the case of trauma, any clear signs of abdomen infection, severe instability, or visible fluid in the abdomen could call for surgery. Retroperitoneal injuries often occur with other abdominal injuries. Every patient needs to be assessed thoroughly and treated based on the extent of the injuries. For example, if a patient suffers abdominal trauma due to a penetrating object like a knife, a retroperitoneal hematoma may occur because of injury to solid organs, internal organs, or blood vessels, often requiring surgical management. For patients with blunt abdominal trauma, the decision to perform surgery is dependent on the patient’s medical stability and the ability to identify the underlying cause. Symptoms like persistent instability, expanding, or pulsating hematoma would also require surgery.
Using medical imaging like a computed tomography (CT) scan, which uses X-rays to create detailed images of the body, doctors can understand the specific location of the hematoma. For centrally located hematomas, they are often explored because they usually are due to injury to large blood vessels or their branches. On the other hand, injuries located on the side usually involve damage to the kidneys and only require surgery if the hematoma is large, expanding, or leaking contrast dye. Those related to pelvic fractures and often involve venous bleeding are usually not treated with surgery. Initial treatment involves using external pelvic fixation or binding to reduce or stop the bleeding. The final treatment typically involves using angiography, a medical imaging technique, to block the bleeding vessels.
For non-trauma caused retroperitoneal hematomas, treatment is often determined by the location and characteristics of bleeding. It is common to reverse blood thinners in patients to prevent more bleeding. Additionally, the right fluid replacement should be given to patients demonstrating instability. Blood transfusion might also be needed in patients with signs, symptoms, or lab findings of anemia. The specific treatment will depend on the location and extent of bleeding and whether or not there is evidence of a leak from the contrast dye on a CT scan. Past studies have shown that most patients with spontaneous and post-procedural retroperitoneal hematomas often improve with supportive care and blood transfusions only.
In some cases, a quarter of the patients needed an embolization procedure, and a few had to undergo surgery. Most of the patients received a blood transfusion. In another study of 100 patients with retroperitoneal hematomas, only a small portion needed invasive treatment, like an angiographic procedure or surgery. Significant predictors for needing invasive therapy included a leakage of contrast dye in CT imaging.
What else can Retroperitoneal Hematoma be?
When a doctor is trying to make a diagnosis, they may consider several possibilities. Here are some potential diagnoses, classified as either traumatic (resulting from injury), or non-traumatic:
Traumatic conditions:
- Acute abdomen
- Perforated viscus: An injury to an organ in the abdomen
- Solid organ injury: Damage to organs such as the liver, spleen, kidneys, or heart
- Vascular injury: Damage to the blood vessels
- Pelvic fracture: A break in the pelvic bone
- Abdominal compartment syndrome: A severe condition where pressure in the abdomen increases, affecting organ function
Non-traumatic conditions:
- Gastrointestinal bleeding: Bleeding in the digestive tract
- Musculoskeletal pain: Pain in the muscles, ligaments and tendons, and bones
- Appendicitis: Inflammation of the appendix
- Cholecystitis: Inflammation of the gallbladder
- Diverticulitis: Inflammation or infection of pouches in the colon
- Abdominal aortic aneurysm: A bulge in the aorta, the main blood vessel of the body, which could rupture and cause life-threatening bleeding
- Pancreatitis: Inflammation of the pancreas
- Pyelonephritis: Kidney infection
What to expect with Retroperitoneal Hematoma
The outcomes for patients with retroperitoneal hematomas – a collection of blood in the area around the kidneys and pancreas – can vary depending on the severity and type of injury they’ve experienced. For example, injuries to the aorta (the body’s main artery) tend to be much more serious than injuries just to the kidney. This is seen in research showing retroperitoneal hematomas caused by aortic injuries had much higher rates of serious outcomes and death than those caused by isolated kidney injuries.
For one group of patients primarily with blunt trauma-related retroperitoneal hematomas, the mortality rate was 6.5% with around 77% needing surgery. However, in another group comprising mostly victims of penetrating trauma the mortality rate was much higher at 18%.
Prognosis is generally worse for spontaneous retroperitoneal hematomas – those not caused by a traumatic injury. This is frequently seen in older patients with other serious health conditions. In one study, the mortality rate for these patients was 10% within the first 30 days and 40% needed intensive care. This information suggests that nearly half of spontaneous retroperitoneal hematomas are serious medical emergencies.
Possible Complications When Diagnosed with Retroperitoneal Hematoma
Retroperitoneal hematoma, which is a collection of blood in the area at the back of the abdomen, can lead to a number of complications. This includes getting infections or sepsis, having symptoms due to less red blood cells in the body (anemia), severe bleeding that can lead to heart attack, kidney damage, liver damage or poor blood flow to the brain, abdominal compartment syndrome which is a life-threatening condition related to increased pressure in the abdomen, and blockage of the small bowel or urine flow.
Complications of Operations:
- Infection
- Damaging structures near the surgical site
- Bleeding becoming worse
When blood vessels are blocked (angioembolization) to stop bleeding, complications can also occur. This can lead to infections, damaging the blood vessels, increased bleeding, kidney damage due to dye used for the procedure (contrast-induced nephropathy), and poor blood flow in the areas served by the blocked arteries (ischemia).
Preventing Retroperitoneal Hematoma
Retroperitoneal hematomas are generally caused by traumatic injuries. Examples of such injuries include car accidents, falls, and violent acts like shootings or stabbings. For most cases of trauma, emphasis is put on preventing these accidents from happening in the first place. This might include measures such as improved health policies and better public health services. These measures aim to keep the public safe and prevent traumatic incidents from occurring.
