Mesenteric Traction Syndrome: Clinical Features, Diagnosis, and Management

Introduction:

Mesenteric traction syndrome occurs in approximately 50 percent of abdominal, upper gastro-intestinal, pancreatic, and aortic surgeries within 15 minutes post-incision and may last up to 30 minutes. MTS is caused by vasodilation and subsequent increase in cardiac output. This may negatively affect postoperative recovery and is also associated with postoperative morbidity.

What Is Mesenteric Traction Syndrome (MTS)?

Mesenteric traction syndrome is a triad of symptoms that include low blood pressure, tachycardia (increased heart rate), and hot flashes. This occurs as a result of histamine release due to traction of the small intestine and mesentery during abdominal surgery.

What Happens in Mesenteric Traction Syndrome (MTS)?

• Pathophysiology: MTS occurs as a result of traction of the mesentery during surgery, which in turn causes prostacyclin (PGI2) release. In the initial phases of incision, traction induces shear stress in the endothelial cells of mesenteric blood vessels, initiating COX (cyclo-oxygenase) and leading to increased production of PGI2 ( prostacyclin), resulting in vasodilation throughout the body. This occurs to compensate for decreased splanchnic blood flow caused due to vasodilation. Although prostacyclins prevent splanchnic ischemia, hypotension occurs to some extent. That is the reason abdominal and thoracic surgeries are major risk factors for MTS. Due to hemodynamic stability, marked facial flushing occurs and thus requires anesthetic interventions.

What Are the Symptoms of MTS?

MTS is characterized by a triad of symptoms, which include,

• Hot Flashes: This is caused due to increased vasodilation caused by PGI2 release.

• Tachycardia: This is characterized by increased heart rate.

• Hypotension: As a result of decreased vascular resistance occurs.

How Is MTS Diagnosed?

1.Whole Triad: The gold standard for the diagnosis of MTS will be the triad of symptoms of which facial flushing will directly point out the condition, differentiating it from other conditions.

2.Facial Flushing: Recent studies have come up with a grading system for facial flushing as diagnostic criteria. The three grades of facial swelling are:

• • No MTS (no flushing).
  • Moderate MTS (grade 1 or partial facial flushing).
  • Severe MTS (grade 2 or complete facial flushing).

3. Hypotension: Systolic blood pressure decreased up to 70 percent or below the baseline blood pressure or absolute decrease of systolic blood pressure to 90 mm of Hg.

4. Flow Trac Sensor: Measures SVV (stroke volume variation) and SVRI (systemic vascular resistance index).

How Does MTS Impact Intraoperative Procedure?

• MTS occurs as a result of abdominal exploration in the initial phases of surgery after an incision in the first 15 minutes of the procedure, decreasing splanchnic circulation. This leads to the prostacyclin release (PGI2) (a potent vasodilator), causing hypotension leading to reduced systemic vascular resistance and decreased cardiac output, and reduced (MAP) or mean arterial pressure ending up with facial flushing.

• The more severe the MTS, the lower the SVR (systemic vascular resistance) values will be in those patients.

• As a counter-effect, the heart rate increases, leading to tachycardia.

• Also, the duration of the surgery tends to be prolonged with cases of developing MTS.

• However, with the administration of vasopressor therapy and due to anesthetic effects, the situation can be taken under control.

How Does MTS Impact Postoperative Recovery?

There is a strong link between MTS and,

• Postoperative complications.

• Postoperative morbidity.

• Delayed recovery and prolonged hospital stay.

• Increased risk of being shifted to ICU (intensive care unit).

How Is MTS Treated?

Various preventative and therapeutic measures have been adopted for preventing and treating MTS and the associated postoperative complications during and after surgery. The measures involved are:

1. Alternative Surgical approach:

• MTS can be prevented by opting for laparoscopic surgeries over open ones.

• The retroperitoneal approach is associated with low incidences of MTS and also prevented PGI2 (prostacyclin) release and associated tachycardia and hypotension, compared to the conventional approach in case of repair of abdominal aortic aneurysm.

2. Pharmacological Interventions:

• Non-selective NSAIDs (Non-steroidal Anti-inflammatory Drugs): The administration of non-selective NSAIDs is linked with a relatively decreased incidence of MTS.

• Ibuprofen: Ibuprofen works by inhibiting the release of PGI2 (prostacyclins). This leads to a reduced decrease of SVR and higher MAP in patients pre-treated with Ibuprofen.

• Flurbiprofen Axetil: Non-selective COX (cyclo-oxygenase) inhibitors like Flurbiprofen Axetil have significantly reduced the risk of developing MTS intraoperatively, and the effects of administering Flurbiprofen after developing MTS was associated with quicker normalization of the hemodynamics.

• Indomethacin: Linked with lower incidence of MTS.

• Corticosteroids: A single dose of 125 mg of Methylprednisolone following the administration of anesthesia is associated with a lower incidence of MTS.

• Remifentanil: Remifentanilinfusions during the surgery have to be avoided as there is reduced MTS incidence by avoiding the release of prostacyclins and nitric oxide (potent vasodilators) induced by Remifentanil.

• Dexmedetomidine: Did not reduce the MTS incidence. However, it reduced the duration of hypotension caused due to MTS.

• Phenylephrine: For patients suffering from Aspirin allergies or bleeding complications in surgery, vasoconstrictors like Phenylephrine are given.

• Fluid Therapy: It is given to increase the cardiac output assessed by flow trac sensor using systemic vascular resistance index.

Conclusion

Further research should focus on developing an objective diagnosis, increasing knowledge of the pathophysiology behind the MTS and the increased postoperative morbidity in patients developing severe MTS, identifying risk factors of developing severe MTS, and identifying and testing preventative measures and potential therapeutic measures against MTS. MTS is a short-lived phenomenon in hemodynamic events, which subsequently develops following an attack and usually has mild complications if treated in time. However, MTS should be considered seriously in patients with multiple pre-existing comorbidities like cardiovascular instability, which is short-lived and can put them at serious risk for stroke or an acute coronary event.