```html

Omentum Infarction – A Comprehensive Medical Guide

Overview

Omentum infarction (also called omental torsion or omental necrosis) occurs when a segment of the greater omentum – the fatty, apron‑like tissue that hangs down from the stomach and colon – loses its blood supply. The lack of perfusion leads to tissue death (infarction) and can cause sudden, severe abdominal pain.

Although the condition is rare, it is an important differential diagnosis for acute abdomen, especially in young and middle‑aged adults. Reported prevalence varies from 0.1 % to 0.5 % of all patients who undergo surgery for presumed appendicitis or diverticulitis<sup>[1]</sup>. Most cases are identified intra‑operatively because imaging often mimics more common pathologies.

Typical demographics:

• Age: 20–60 years; median age ≈ 38 years
• Sex: Slight male predominance (≈ 60 % male)
• Geography: No clear regional differences; reported worldwide

Symptoms

The presentation can be abrupt and may be mistaken for other causes of an acute abdomen. Common symptoms include:

• Sudden, localized abdominal pain – usually right‑lower or right‑upper quadrant; pain is constant and may radiate to the back or shoulder.
• Abdominal tenderness – deep, non‑rebound tenderness on palpation; guarding may be present.
• Nausea and vomiting – often mild to moderate; less frequent than with appendicitis.
• Low‑grade fever – temperature < 38 °C (100.4 °F) in up to 30 % of cases.
• Loss of appetite (anorexia) – common but not specific.
• Altered bowel habits – constipation or mild diarrhea; usually secondary to pain.
• Palpable abdominal mass – a firm, mobile lump may be felt in the affected quadrant in 10‑15 % of patients.
• Elevated white blood cell count – leukocytosis in 40‑60 % of cases, reflecting inflammation.

Causes and Risk Factors

Primary (idiopathic) omental torsion

Occurs without an obvious precipitating factor. Proposed mechanisms include:

• Congenital or acquired excess omental fat that creates an imbalance of weight.
• Anatomical variations such as a bifid omentum or a long pedicle predisposing the tissue to twist.

Secondary omental torsion

More common; a pre‑existing intra‑abdominal condition “fixes” part of the omentum, allowing another portion to rotate and occlude its vessels. Common triggers:

• Inflammatory diseases – appendicitis, diverticulitis, cholecystitis, pelvic inflammatory disease.
• Adhesions from previous abdominal surgery or trauma.
• Large intra‑abdominal cysts or tumors that shift omental position.
• Obesity – excess visceral fat adds weight and increases torsion risk<sup>[2]</sup>.
• Sudden, vigorous physical activity or heavy lifting, which can cause rapid movement of a heavy omentum.

Risk factors summary

• Male sex
• Obesity (BMI ≥ 30 kg/m²)
• Recent abdominal surgery or trauma
• Inflammatory intra‑abdominal disease
• Rapid weight gain or loss (altering fat distribution)

Diagnosis

Because symptoms overlap with many surgical emergencies, a systematic approach is essential.

Clinical evaluation

• Detailed history focused on pain onset, location, aggravating factors, and recent surgeries.
• Physical exam for localized tenderness, guarding, and possible palpable mass.

Imaging studies

1. Ultrasound (US) – first‑line in many emergency departments. Findings may include a hyperechoic, non‑compressible omental mass with peripheral “whirl” sign. Sensitivity ≈ 70 %.
2. Contrast‑enhanced computed tomography (CT) – gold standard. Typical CT features:
   • Focal area of fatty infiltration with a concentric “whirl” pattern of omental vessels.
   • Heterogeneous fat attenuation (−80 to −120 HU) surrounded by inflamed peritoneum.
   • No signs of appendicitis, diverticulitis, or other intra‑abdominal pathology.
   CT correctly identifies omental infarction in > 90 % of cases<sup>[3]</sup>.
3. MRI – rarely needed but useful when radiation avoidance is a priority (pregnancy); shows similar fat‑signal changes.

Laboratory tests

• Complete blood count – leukocytosis in many patients.
• C‑reactive protein (CRP) – elevated, reflecting inflammation.
• Serum lactate – may rise if extensive necrosis occurs.

Diagnostic laparoscopy

If imaging is inconclusive and the patient’s clinical picture worsens, minimally invasive surgery can confirm the diagnosis and simultaneously treat the infarction.

Treatment Options

Management depends on severity, location, and patient stability.

Conservative (non‑operative) care

Appropriate for small, isolated infarcts without peritonitis.

• Analgesia – acetaminophen or short courses of NSAIDs (unless contraindicated).
• Fluid therapy – IV crystalloids to maintain perfusion.
• Antibiotics – broad‑spectrum coverage (e.g., ceftriaxone + metronidazole) if secondary infection is suspected.
• Observation – repeat abdominal exam and serial labs every 6‑12 h.
• Most patients improve within 48‑72 h; follow‑up CT may be performed to confirm resolution.

Surgical intervention

Indicated when there is:

• Signs of peritonitis, abscess, or ongoing hemorrhage.
• Failure of symptoms to improve after 24‑48 h of conservative therapy.
• Large or twisted omentum seen on CT.

Procedures:

1. Laparoscopic omentectomy – removal of the necrotic segment; preferred due to reduced wound infection, shorter stay (average 2‑3 days), and faster recovery.
2. Open laparotomy – reserved for massive infarcts, hemodynamic instability, or when additional pathology is suspected.
3. In rare cases, omentoplasty (repositioning viable omentum) may be performed to preserve tissue.

Post‑operative care

• Pain control (opioids short‑term, then NSAIDs).
• Early ambulation – reduces risk of venous thromboembolism.
• Gradual diet advancement – start with clear liquids, then soft diet as tolerated.
• Prophylactic antibiotics for 24 h if contamination was present.

Living with Omentum Infarction

Even after successful treatment, patients may wonder how to return to normal life.

Activity

• First 2 weeks: limit heavy lifting (> 10 kg) and vigorous exercise.
• After 4 weeks: gradual return to regular activity; monitor for recurrent pain.

Dietary considerations

• Maintain a balanced diet rich in fiber to avoid constipation, which can increase intra‑abdominal pressure.
• Limit excessive fatty foods that could promote visceral fat accumulation.
• Stay hydrated (≥ 2 L water/day) unless contraindicated.

Follow‑up

• Outpatient visit 1‑2 weeks post‑surgery or after discharge from conservative care.
• Repeat abdominal ultrasound or CT only if symptoms recur.

Psychological impact

Acute abdominal emergencies can be stressful. Consider counseling or support groups if anxiety about recurrence develops.

Prevention

Because many cases are secondary, preventing underlying risk factors is key.

• Weight management – aim for BMI < 25 kg/m²; use a combination of diet, exercise, and behavioral therapy.
• Physical activity – regular moderate exercise (150 min/week) improves visceral fat distribution.
• Prompt treatment of abdominal infections – early antibiotics for appendicitis, diverticulitis, etc., reduces secondary omental torsion.
• Avoid sudden, extreme strain – lift with proper mechanics, avoid heavy lifting immediately after large meals.
• Post‑operative care – follow surgeon’s instructions on activity after abdominal surgery to reduce adhesion formation.

Complications

If left untreated, omentum infarction can lead to serious outcomes:

• Peritonitis – inflammation of the peritoneal cavity due to necrotic tissue leaking inflammatory contents.
• Abscess formation – localized collection of pus; may require drainage.
• Sepsis – systemic infection with potential organ failure.
• Intestinal obstruction – adhesions or mass effect from the necrotic omentum can block bowel transit.
• Hemoperitoneum – bleeding into the abdominal cavity if large vessels are torn during torsion.

Mortality is low (< 1 %) when managed promptly, but delays increase risk of the above complications<sup>[4]</sup>.

When to Seek Emergency Care

References

1. Al‑Saadi M, et al. “Omental torsion: a rare cause of acute abdomen.” World J Surg. 2020;44(5):1580‑1586.
2. World Health Organization. “Obesity and overweight.” 2023. https://www.who.int
3. Singal R, et al. “CT findings in primary and secondary omental infarction.” Radiology. 2021;298(2):E345‑E352.
4. Mayo Clinic. “Omental torsion.” 2022. https://www.mayoclinic.org
5. Cleveland Clinic. “Acute abdomen: evaluation and management.” 2023.

```