What is Bowel Necrosis?
Bowel necrosis is a severe condition that often occurs as a result of many different diseases. Essentially, it’s when the cells in the digestive tract die off because they aren’t receiving enough blood. This can be a result of blocked blood vessels, inflammation, blockages, or infection. This condition can be deadly and is often found in the later stages of diseases that lessen blood flow to the digestive system.
In babies, bowel necrosis is typically due to a condition called necrotizing enterocolitis. This is believed to be triggered by too much bacteria growth because the baby’s immune system hasn’t fully developed yet. In adults, bowel necrosis usually happens because of a sudden blockage in the mesenteric blood vessels that supply the intestines. Other less common causes include perforations (holes), ongoing restricted blood flow, inflammatory disease, and blockages.
Unfortunately, bowel necrosis often coincides with severe bacterial infection spreading throughout the body, known as septic shock, and the general outlook is poor. The best shot at reducing deaths from bowel necrosis hinges on identifying and treating it early.
What Causes Bowel Necrosis?
The main reasons for bowel necrosis, or the death of bowel tissue, often come from a severe blockade in the arteries. This can be caused by a type of blood clot known as a thromboembolism, which often occurs in people who have a heart condition called atrial fibrillation. It can also happen if there’s a hole in the heart, known as a patent foramen ovale, or if there’s a hole in the bowel that lets bacteria in.
Other less common causes are blood clots in the veins, long-term reduced blood supply, autoimmune disease, or blockages that don’t allow food to pass through the bowel. Non-obstructive mesenteric ischemia, a condition where there’s not enough blood going to the intestines, also causes bowel necrosis.
People with severe problems in their blood vessels or other health conditions often suffer from these issues. Experts think that a mix of infections, immune system responses, and injuries from blood returning to tissues after a period of lack of oxygen, can lead to reduced blood supply, holes in the bowel, and ultimately, bowel necrosis.
Risk Factors and Frequency for Bowel Necrosis
Bowel necrosis, or the death of bowel tissue, is the final stage of several different diseases, making it tough to determine how often it occurs. One of the main culprits is acute ischemic bowel, which is a rare condition that only accounts for about 0.09% to 0.2% of surgical hospital admissions.
- About half of these cases are caused by embolic events, where an obstruction moves and blocks a blood vessel.
- 30% are due to plaque rupture, where deposits on the inner wall of an artery break open.
- 10% to 20% result from venous obstruction, which is a blockage in a vein.
- Less than 5% are due to other issues, like a tear in an artery wall (dissection), an unusually strong contraction of the muscles in the artery walls (vasospasm), or inflammation.
Signs and Symptoms of Bowel Necrosis
Bowel necrosis, or the death of bowel tissue, has various causes and the symptoms can vary. Understanding a patient’s medical history is key to identifying the cause, especially in the early stages of the disease where physical examinations may not provide a clear diagnosis. Often, patients with bowel necrosis will mention certain health issues:
- A history of blood clots, including deep vein thrombosis (DVT) or pulmonary embolism (PE)
- A history of irregular heartbeat, or atrial fibrillation
- Previous experiences of pain after eating, loss of appetite, nausea or vomiting, and unexplained weight loss
Some patients may have a history of risk factors that can cause bowel tissue to perforate, or break, leading to an infection or necrosis. These can include conditions such as peptic ulcers, heavy use of NSAIDs, alcoholism, inflammatory bowel disease (IBD), or the use of steroids.
There are other less common triggers of bowel necrosis that result in reduced blood flow. These patients often have vascular risk factors like diabetes, peripheral vascular disease, or a history of smoking. They could present with symptoms such as chronic pain, general abdominal pain, and signs of sepsis or shock.
The exact type and severity of abdominal pain can depend on several factors. Acute arterial obstruction of the superior mesenteric artery could cause severe pain around the belly button accompanied by nausea and vomiting. Chronic mesenteric ischemia, however, may present with increasing pain after eating, and subsequent loss of appetite and weight. Venous thrombosis, the formation of a blood clot inside a vein, might cause non-specific pain that comes and goes. Lastly, nonocclusive mesenteric ischemia, where the mesenteric artery is not blocked but blood flow is reduced, could have a variable presentation and is often associated with other serious conditions like peripheral vascular disease (PVD), congestive heart failure (CHF), or kidney failure requiring dialysis.
During a physical exam, patients may seem clearly unwell and sweaty. Their abdominal pain level can range from sharply out of proportion compared to the physical examination findings, to a rigid, painful abdomen—often a sign of peritonitis, inflammation of the peritoneum.
Testing for Bowel Necrosis
If someone might have a serious condition called bowel necrosis, doctors need to act fast, and be highly suspicious of this condition. Just like with any sick patient, the first thing to do is to check basic elements like their airway, breathing, and circulation. Throughout this process, it is important to establish an intravenous (or IV) line and keep an eye on their heart and circulatory functions. In some cases, the patient may need help with their breathing, such as through intubation, but the doctor should try to stabilize their blood pressure first.
It could be hard at first to figure out exactly why the patient is in shock. To get more information, the doctor might use ultrasound, an electrocardiogram (or ECG), a portable chest X-ray, blood tests checking for certain chemicals (basic metabolic panel or BMP), and a test to check the balance of gases in the blood (arterial blood gas or ABG). These tests can help the doctor figure out what type of shock the patient is experiencing and understand the underlying causes. Additional tests would include a full count of the different types of cells in the blood (complete blood count or CBC), a complete metabolic panel, blood clotting tests (INR and PTT), tests to check for bacteria in the blood (blood cultures), and a test to check the amount of lactic acid in the blood.
If the patient’s condition worsens even with proper medical intervention, it might be best to quickly proceed to surgery so the doctor can look inside the abdomen and figure out what’s happening (emergency exploratory laparotomy). If not, the doctor will order a quick CT scan with IV contrast. This type of scan helps visualize the organs in the abdomen and pelvis and can show any damage or dead tissue (ischemia or necrosis) in the intestines. Waiting for the results of blood tests should not delay this scan, because the benefits of contrast generally outweigh any potential harm to the kidneys in this critical situation.
The scan might show air inside the wall of the intestine (pneumatosis intestinalis), which points towards damaged defense mechanisms and bacterial invasion. Gas may also be seen within the blood vessels that lead to the liver (portal vasculature). According to one study, en enhanced CT scan can accurately diagnose acute issues with blood flow to the intestines (mesenteric ischemia) about 93.3% of the time and can correctly rule out this condition about 96% of the time. If the diagnosis still isn’t clear, the doctor might recommend a special type of imaging test (angiography) which can show blocked or narrow blood vessels.
Treatment Options for Bowel Necrosis
Bowel necrosis, or when parts of the bowel die, is a severe medical condition that needs immediate surgery. First steps in treatment include taking quick measures to recognize the condition, ensuring the patient is well-hydrated, maintaining blood pressure, administering a wide range of antibiotics like vancomycin and piperacillin-tazobactam, and providing pain relief. If serious infection has made the patient extremely ill and they can’t protect their airway, they may need a breathing tube (intubation).
If the patient remains unstable despite these measures, doctors usually recommend an emergency exploratory surgery (laparotomy). For those patients whose condition stabilizes, a CT scan with a technique called angiography is performed to help plan for the surgery.
If the CT scan reveals a sudden blockage in an artery (acute arterial embolism), and there are no signs of inflammation in the abdomen (peritonitis), hole in the gut (perforation), or tissue death (necrosis), procedures to remove this blockage or dissolve it may be performed. If the CT scan or angiography detects a blood clot in a blood vessel (venous thrombosis), doctors may recommend a treatment that helps prevent more clots from forming (anticoagulation).
If the patient continues to be unstable, has an ongoing infection, or there’s evidence of a perforation, gas outside the intestines, or tissue death, the next step is exploratory surgery (laparotomy) to remove the affected parts of the bowel.
If doctors suspect nonocclusive mesenteric ischemia, a condition where the intestines don’t receive enough blood due to heart problems, certain medications, or dialysis, the patient’s initial treatment is also hydration. If the patient’s condition improves, they may be admitted to the hospital for further care. If the patient still complains of abdominal pain but doesn’t show inflammation of the peritoneum (peritonitis), a contrast-enhanced CT scan is recommended to look for a perforation, gas outside the intestines, or necrosis. In cases where there’s vessel narrowing or spasms, medications that dilate blood vessels may be used. If the patient’s symptoms don’t improve, or if they remain unstable, surgery may be necessary. For many patients with this condition, they might need another procedure even after the initial treatment.
What else can Bowel Necrosis be?
Patients with a condition called bowel necrosis may exhibit a wide range of symptoms. These can be due to the root cause of their illness and can range from intense stomach pain to changes in mental conditions and severe infection, typically known as septic shock. When diagnosing, doctors must consider several possibilities:
- Different types of infection such as pyelonephritis (a kidney infection), cholangitis (an infection in the bile duct), and diverticulitis (an infection in the digestive tract).
- Various causes of shock such as septic (from infection), cardiogenic (from heart problems), hemorrhagic (from excessive bleeding), and distributive (usually from severe infection or burn).
- Different causes of bowel necrosis such as acute versus chronic lack of blood supply, perforation (a hole or tear), thrombotic emboli (blood clot), and obstruction (blockage).
These multiple possibilities underline the importance for doctors to consider all potential causes and perform the necessary tests to reach the right diagnosis.
What to expect with Bowel Necrosis
For patients suffering from this disease, even with timely correct treatments that include surgery, the mortality rate remains extremely high. If the condition is not treated effectively, and the bowel becomes necrotic, meaning it dies, it can lead to almost 100% mortality rate. The overall surgical mortality rate for a complication called acute mesenteric ischemia is reportedly at 47%. It should also be mentioned that even those patients who survive the initial event often have a high likelihood of encountering complications after the surgery.
Possible Complications When Diagnosed with Bowel Necrosis
Bowel necrosis, or the death of bowel tissue, can lead to a variety of health problems. These include sepsis, which is a severe infection that can lead to low blood pressure and damage to the kidneys and liver. People who need emergency surgery due to bowel necrosis may have infections or blockages after the operation. Even if they survive the initial treatment, these individuals often continue to have higher-than-normal risk of death. This is usually due to other health conditions they may have, and can frequently lead to long-term disabilities.
Key Health Risks:
- Sepsis: a severe infection that can result in low blood pressure and kidney and liver damage
- Post-operative infections: Possible complications from emergency surgery
- Post-operative obstructions: Blockages that can occur after surgery
- Elevated mortality rate: Even after surviving the initial treatment, patients may still have a higher risk of death due to their underlying health conditions
- Long-term disability: Ongoing health problems that can affect a patient’s quality of life
