Síndrome de Mallory-Weiss

O que é a síndrome de Mallory-Weiss?

Mallory-Weiss syndrome (MWS) is characterised by upper gastrointestinal bleeding (UGIB) from mucosal lacerations in the upper gastrointestinal tract, usually at the gastro-oesophageal junction or gastric cardia. Mallory and Weiss described the syndrome in 1929 in patients retching and vomiting after an alcoholic binge.

MWS may also occur with other events which cause a sudden rise in intragastric pressure or gastric prolapse into the oesophagus. Sudden increased pressure within the nondistensible lower oesophagus causes tearing.

• Acute UGIB is an emergency and has a mortality overall between 7% and 14%.

• It has an incidence of 84-170/100,000 adults/year in the UK.

• Mallory-Weiss tears account for 4-8% of cases of UGIB.

• There is a wide age range. It is most common between the ages of 30 and 50 years. Tears can occur in children but are less common.

• Mallory-Weiss tears may have become more common in recent years.³

Haematemesis due to a Mallory-Weiss tear usually occurs after a prolonged or forceful bout of retching, vomiting, coughing, straining or even hiccupping.

Fatores de risco

• Excessive alcohol ingestion.

• Conditions predisposing to retching and vomiting. For example:

  • Gastroenterite.

  • Hiperêmese gravídica (the most common cause in women of child-bearing age).⁴

  • Bulimia.

  • Doença renal.

  • Pressão intracraniana elevada.

  • Biliary disease (gallstones and cholecystitis).

  • Hepatite.

  • Enxaqueca.

  • Síndrome de vômito cíclico.

  • Gastrointestinal obstruction.

  • Medication such as chemotherapy.

• Chronic cough or acute causes of prolonged coughing bouts. For example

  • Doença pulmonar obstrutiva crônica (DPOC).

  • Câncer de pulmão.

  • Bronquiectasia.

  • Coqueluche.

  • .

• Hérnia de hiato. During retching or vomiting, the transmural pressure gradient is greater within the hiatus hernia than the rest of the stomach.

• Blunt abdominal trauma and cardiopulmonary resuscitation.

• Iatrogenic. Tears during upper gastrointestinal instrumentation are uncommon, even with the high incidence of retching during endoscopy.

• Ingestion of aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs).

• In some patients no apparent precipitating factor can be identified.

História

• The classic presentation is of haematemesis following a bout of retching or vomiting. However, a tear may occur after a single vomit.

• Other symptoms include melaena, light-headedness, dizziness, or syncope, and features associated with the initial cause of the vomiting - for example, abdominal pain.

Exame

• There are no specific physical signs.

• An assessment of the degree of blood loss should be made. The Rockall scoring system can be used to assess UGIB.⁵ A score of less than 3 is associated with an excellent prognosis, and 8 or above an extremely poor prognosis. MWS is usually associated with a score of 3 or less.

• The Glasgow-Blatchford score was developed to predict the need for intervention in UGIB. It may be more accurate than the Rockall system, but requires laboratory data.⁶

Haematemesis as a symptom has quite a long differential diagnosis. The following are important to consider (particularly with the retching and sudden bright bleeding associated with MWS):

• Boerhaave's syndrome (oesophageal rupture).⁷

• Other causes of UGIB - see the separate Upper gastrointestinal bleeding (includes Rockall Score) artigo.

Endoscopy is the primary diagnostic investigation. Other relevant investigations include:

• FBC, including haematocrit to assess the severity of the initial bleeding episode and to monitor patients.

• Coagulation studies and platelet counts to detect coagulopathies and thrombocytopenias (routine platelet count, prothrombin time, and activated partial thromboplastin time).

• Renal function, urea, creatinine, and electrolyte levels (to guide intravenous fluid therapy).

• Cross-matching/blood grouping and antibody screen (potential blood transfusion).

• Electrocardiogram and cardiac enzymes (may be indicated if myocardial ischaemia is suspected).

• Angiography may be indicated in actively bleeding tears in the event of failure or difficulty in finding the site of the bleeding tear via endoscopy.⁸

Initial management is described in the separate Upper gastrointestinal bleeding (includes Rockall Score) artigo.

Initial assessment and management

• Resuscitation is a priority - maintain airway, provide high-flow oxygen, correct fluid losses (place two wide-bore cannulae and also send bloods at the same time). Initial fluid resuscitation may be with crystalloids or colloids; give intravenous blood when 30% of circulating volume is lost.⁹ Follow major haemorrhage protocols, which should be in place.

• Once the patient is more stable - take a history and perform an examination. Identify severity of blood loss and treat any comorbid conditions.

• MWS usually follows a benign course but occasionally endoscopic treatment is required to stop bleeding.

Endoscopia⁵

• Ideally, endoscopy should be performed within 24 hours, as tears heal rapidly and may not be readily apparent at endoscopy after 2-3 days. Haemodynamically unstable patients should have endoscopy immediately after resuscitation.

• Proton pump inhibitor (PPI) use is not recommended prior to diagnosis by endoscopy. The National Institute for Health and Care Excellence (NICE) does not recommend treatment with a PPI or an H2-antagonist before endoscopy. However, it does recommend offering a PPI to patients with non-variceal upper gastrointestinal bleeding and stigmata of recent haemorrhage shown at endoscopy.

• Most patients stop bleeding spontaneously.¹ A few will require endoscopic intervention. NICE recommends clipping with or without adrenaline (epinephrine), thermal coagulation with adrenaline, or thrombin or fibrin with adrenaline.

• Most patients present with a single tear. The tear is usually just below the gastro-oesophageal junction on the lesser curvature of the stomach.

• Tears may be associated with other mucosal lesions. These may contribute to bleeding and/or cause the retching and vomiting. Endoscopic examination should be thorough to look for co-existing lesions.

Post-initial endoscopy⁵

Calculate the full (post-endoscopic) Rockall Score, as described in the separate Upper gastrointestinal bleeding (includes Rockall Score) article. A score <3 is associated with low risk of re-bleeding or death and can be considered for early discharge, whereas a score >3 indicates patients need further close observation as an inpatient.

• Careful monitoring is needed after endoscopy for UGIB (pulse, blood pressure, urine output). It is imperative to identify re-bleeding or continuing bleeding.

• Risk factors for re-bleeding include cirrhosis and renal failure. The incidence is one study was 21%.¹⁰ These and those with certain endoscopic findings (non-bleeding visible vessel, pigmented protuberance, or adherent clot) should be observed for 48 hours.¹¹

• If patients are stable 4-6 hours after endoscopy they should be put on a light diet, as there is no benefit in continued fasting.

• Occasionally the bleeding cannot be stopped using endoscopic treatments. Interventional radiology should be considered in such cases. Rarely, surgery is required to close the tear.

• If re-bleeding occurs, it usually takes place within 48 hours. Shock at initial manifestation and active bleeding at endoscopy are risk factors predicting recurrent bleeding in patients with MWS.¹²

These relate to:

• Sintomas:

  • Vomiting (hipocalemia and other metabolic disturbance, pneumonia por aspiração, perforation and mediastinitis).

• Severity of bleeding:

  • Hypovolaemic shock, and death (very rare with good care).

  • Re-bleeding. (More common in those with shock at presentation, lower haemoglobin levels, multiple transfusions or active bleeding seen at endoscopy.)

  • Myocardial ischaemia or infarction.

• Comorbidities:

  • Myocardial ischaemia (precipitating, for example, infarto do miocárdio).

  • Hepatitis (precipitating, for example, liver failure).

  • Renal disease (precipitating, for example, lesão renal aguda ou acute on chronic kidney disease).

  • Diabetes (worsening control and diabetic coma).

• Treatment or investigation:

  • Endoscopy (mediastinitis, aspiration pneumonia, perforation or aggravation of bleeding).

  • Angiotherapy (organ ischaemia and infarction, aggravation of bleeding).

• The prognosis is generally excellent. Most patients usually stop bleeding spontaneously and the tears heal rapidly, usually within 48-72 hours. The majority have stopped bleeding by the time of endoscopy.¹

• However, bleeding is variable and can range from a few specks or streaks of blood mixed with mucus to large amounts of fresh blood.

• Re-bleeding is more common in those with risk factors (see under 'Prevention' section, below) .

• Associated diseases may have a significant effect on prognosis - for example, cirrose carries a very poor prognosis.¹²

Recurrence is rare but it makes sense to counsel patients about precipitating factors (for example, binge drinking, alcohol consumption, excessive straining and lifting, violent coughing) that may lead to a recurrence and are generally hazardous to health. Risk factors for recurrent bleeding include:¹²

• Initial presentation of shock.

• Cirrose hepática.

• Decreased haemoglobin and platelet count.

• Need for blood transfusion.

• Intensive care management.

• Active bleeding noted at the time of endoscopy.