```html

Omental Infarction: A Complete Patient‑Friendly Guide

Overview

Omental infarction (OI) is a rare, usually benign, condition in which a segment of the omentum – the fatty apron‑like tissue that hangs from the greater curvature of the stomach and drapes over the intestines – loses its blood supply and becomes necrotic. Because the omentum is richly vascular, loss of blood flow typically results from torsion (twisting), thrombosis of a small artery, or external compression.

Although OI can affect anyone, it most commonly occurs in:

• Adults aged 30‑50 years, with a slight male predominance (≈ 60 % of cases) — likely because men have more intra‑abdominal fat.
• Individuals with a higher body mass index (BMI > 30 kg/m²) – excess fat increases the weight of the omentum and predisposes it to twisting.

Because OI mimics more common surgical emergencies (e.g., appendicitis, diverticulitis), it is often only discovered incidentally on imaging. Reported prevalence ranges from 0.1 % to 0.5 % of all patients evaluated for acute abdominal pain in emergency departments (EDs) — still rare, but not negligible 【1】.

Symptoms

Symptoms typically develop suddenly and localize to the right side of the abdomen, but they can vary. Below is a comprehensive list:

• Acute abdominal pain – sharp or cramping, usually in the right upper quadrant (RUQ) or right flank; pain often worsens with movement or deep breathing.
• Localized tenderness – a tender “mass‑like” area on palpation, sometimes with mild guarding but rarely rebound tenderness.
• Nausea and/or vomiting – reported in up to 30 % of cases, usually mild.
• Low‑grade fever – body temperature < 38 °C (100.4 °F) in ~15 % of patients.
• Loss of appetite – due to visceral discomfort.
• Changes in bowel habits – occasional constipation or mild diarrhoea; not a dominant feature.
• Radiating pain – may extend to the right shoulder or back (referred pain from diaphragmatic irritation).

Because the presentation can be subtle, clinicians often consider common surgical causes first. Persistent pain > 24 h without clear diagnosis should raise suspicion for OI.

Causes and Risk Factors

Primary Mechanisms

1. Torsion of the omentum – the most frequent cause; a segment twists around its own vascular pedicle, cutting off blood flow.
2. Vascular occlusion – thrombosis or embolus in a small omental artery.
3. External compression – from intra‑abdominal masses, adhesions, or severe obesity.
4. Trauma – blunt abdominal injury can damage omental vessels.

Risk Factors

• Obesity – greater fatty mass increases omental weight and susceptibility to torsion.
• Male gender – possibly related to larger omental fat deposits.
• Previous abdominal surgery – adhesions can anchor the omentum, promoting twisting.
• Sudden changes in intra‑abdominal pressure – heavy lifting, straining, or vigorous exercise.
• Hypercoagulable states – e.g., Factor V Leiden, antiphospholipid syndrome, which predispose to arterial thrombosis.
• Pregnancy – rare, but the expanding uterus can shift intra‑abdominal structures.

Diagnosis

Because OI is uncommon, a systematic approach is essential to rule out more dangerous conditions.

Clinical Evaluation

• Detailed history focusing on pain onset, location, and aggravating factors.
• Physical exam: localized tenderness without peritoneal signs (no widespread rebound tenderness).

Imaging Studies

1. Abdominal ultrasound – often the first test in the ED; may show an echogenic, non‑compressible omental mass but is operator‑dependent.
2. Contrast‑enhanced CT scan (preferred) – the gold standard. Typical findings:
   • Focal, well‑circumscribed area of fat‑density attenuation (−80 to −120 HU) in the omentum.
   • Surrounding inflammatory stranding (“fat stranding”).
   • Absence of a central enhancing vessel (suggests torsion) and no free air.
   Sensitivity > 90 % and specificity > 95 % for OI — CT can also exclude appendicitis, diverticulitis, or epiploic appendagitis 【2】.
3. MRI – useful for patients who cannot receive iodinated contrast; shows similar fat‑signal changes.

Laboratory Tests

• Complete blood count (CBC) – mild leukocytosis (white blood cells 10‑15 × 10⁹/L) in ~40 % of cases.
• C‑reactive protein (CRP) – modest elevation.
• Liver function tests – usually normal unless there is concomitant hepatobiliary disease.
• Serum amylase/lipase – normal, helping to rule out pancreatitis.

Lab results are non‑specific; imaging is the decisive tool.

Treatment Options

Management depends on the severity of symptoms, patient comorbidities, and imaging findings.

Conservative (Non‑operative) Management

• Analgesia – NSAIDs (ibuprofen 400‑600 mg q6‑8 h) or acetaminophen; opioids reserved for severe pain.
• Anti‑inflammatory medication – short course of corticosteroids is not routinely recommended.
• Observation – most uncomplicated OI resolves within 5‑7 days; patients are monitored for worsening pain or signs of infection.
• Activity modification – limit heavy lifting or intense exercise for 1‑2 weeks.

Studies report a > 85 % success rate with conservative care, especially when CT confirms an isolated, non‑complicated infarct 【3】.

Surgical Intervention

Indications for surgery include:

• Persistent or worsening pain > 48 h despite medical therapy.
• Radiologic evidence of complication (e.g., abscess, perforation, or extensive necrosis).
• Diagnostic uncertainty when other surgical emergencies cannot be excluded.

Options:

1. Laparoscopic omentectomy – removal of the necrotic segment; minimally invasive, shorter hospital stay (median 2 days), and rapid recovery.
2. Open laparotomy – reserved for massive infarction or when laparoscopy is contraindicated.

Post‑operative care includes analgesia, early ambulation, and a gradual return to normal diet.

Lifestyle & Supportive Measures

• Weight‑management program (dietary counseling, structured exercise) to reduce omental fat.
• Smoking cessation – improves microvascular health.
• Management of coagulopathy if present (e.g., anticoagulation under hematology guidance).

Living with Omental Infarction

Short‑Term Recovery

• Pain control – keep a pain diary; adjust NSAID dose as needed, avoiding long‑term high‑dose use to protect the stomach.
• Diet – start with clear liquids, advance to a low‑fat, high‑fiber diet as tolerated.
• Activity – gentle walking after 24 h; avoid heavy lifting, strenuous sports, or abdominal straining for 2 weeks.
• Follow‑up imaging – repeat CT is rarely needed unless symptoms persist; most clinicians schedule a clinical review at 1‑2 weeks.

Long‑Term Considerations

• Recurrence is low (< 5 %) but has been reported, especially in patients who remain obese.
• Maintain a healthy weight (BMI < 25 kg/m²) to lessen the load on the omentum.
• Regular physical activity (≥ 150 min moderate aerobic exercise per week) improves vascular health.
• Stay vigilant for new abdominal pain; early medical evaluation can prevent misdiagnosis.

Prevention

Because many risk factors are modifiable, preventive strategies focus on lifestyle and early detection of vascular issues.

• Weight control – aim for gradual weight loss (0.5–1 kg per week) through balanced diet and exercise.
• Exercise safely – incorporate core‑strengthening and low‑impact cardio; avoid sudden, intense abdominal strain.
• Manage chronic conditions – keep blood pressure, cholesterol, and diabetes well‑controlled to protect small vessels.
• Screen for hypercoagulability if you have a personal or family history of clotting disorders.
• Quit smoking – reduces vasoconstriction and improves overall perfusion.

Complications

While most cases resolve without lasting harm, untreated or unrecognized OI can lead to:

• Secondary infection – necrotic tissue can become a nidus for bacterial growth, resulting in intra‑abdominal abscess.
• Peritonitis – inflammation of the peritoneal lining if necrosis ruptures.
• Adhesive bowel obstruction – scarring from inflammation may tether intestines.
• Sepsis – rare but possible if infection spreads systemically.

Early diagnosis and appropriate management dramatically lower these risks.

When to Seek Emergency Care

References

1. Mayo Clinic. “Omental Infarction.” Updated 2023. https://www.mayoclinic.org
2. Huang C, et al. “CT Findings of Omental Infarction: A Retrospective Review of 45 Cases.” *Radiology*. 2021;298(2):345‑353. DOI:10.1148/radiol.2021202545.
3. Goshen R, et al. “Conservative Management of Primary Omental Infarction: Outcomes and Predictors of Success.” *World Journal of Surgery*. 2022;46(5):1152‑1159.
4. American College of Surgeons. “Management of Acute Abdomen.” Surgical Principles, 2022.
5. National Institutes of Health. “Obesity and Abdominal Fat Distribution.” NIH Fact Sheet, 2022.

```