Inguinal hernia leading to omental torsion: Role of CT in differentiating from other clinical mimics - a case report and literature review

Abstract

Omental torsion is a very rare cause of acute abdomen. Clinically, it mimics other common pathologies such as acute appendicitis, acute diverticulitis and acute cholecystitis. It is therefore no surprise, that it was rarely diagnosed pre operatively before the advent and easy availability of modern imaging techniques. CT scan, in particular, can diagnose omental torsion with confidence pre operatively. This can make conservative treatment possible in cases of primary omental torsion and guide regarding the appropriate treatment in cases of secondary torsion. We present a case of a young male patient who presented to Emergency department with symptoms of acute abdomen. Clinical and laboratory findings were non-specific for any specific cause of acute abdomen. CT scan, however, showed omental fat stranding with whirlpool sign representing omental torsion which was seen to be secondary to left inguinal hernia. Patient was operated in emergency and necrotic omentum was resected and hernia repaired. Post-operative recovery was uneventful.

Keywords: CT scan; Omental torsion; acute abdomen; inguinal hernia; omental inflammation.

Figure 1. 32 year old male with omental torsion secondary to left sided inguinal hernia

FINDINGS: Axial contrast enhanced CT abdomen in the portovenous phase shows central hyperattenuating vessel (A) around which other vessels are arranged concentrically giving whirlpool appearance (B) with surrounding fat stranding (C). Concentric rings are further seen clearly (D). TECHNIQUE: Axial CT portovenous phase obtained on 16 slice scanner at 75 sec after injection of 100 ml Omnipaque; 275 mA; 120 kV; 1.3 mm slice thickness

Figure 2. 32 year old male with omental torsion secondary to left sided inguinal hernia

FINDINGS: Axial contrast enhanced CT abdomen in the portovenous phase shows hyperattenuating concentric streaks in fat beneath parietal peritoneum (A) mild amount of free fluid in right paracolic gutter (B) and left sided inguinal hernia (C) and (D). TECHNIQUE: Axial CT portovenous phase obtained on 16 slice scanner at 75 sec after injection of 100 ml Omnipaque; 275 mA; 120 kV; 1.3 mm slice thickness

Figure 3. 32 year old male with omental torsion secondary to left sided inguinal hernia

FINDINGS: Coronal reformat of contrast enhanced CT abdomen in the portovenous phase shows area of fat stranding in the left hemi abdomen with the stranding extending into left hemi pelvis (A) and the misty omental fat extending into left sided inguinal hernia (B). TECHNIQUE: Coronal reformat CT portovenous phase obtained on 16 slice scanner at 75 sec after injection of 100 ml Omnipaque; 275 mA; 120 kV; 0.8 mm slice thickness

Figure 4. 32 year old male with omental torsion secondary to left sided inguinal hernia

FINDINGS: Sagittal reformat of contrast enhanced CT abdomen in the portovenous phase shows area of fat stranding in the left hemi abdomen with the stranding extending into left hemi pelvis and into the fat in left sided inguinal hernia (A and B). TECHNIQUE: Sagittal reformat CT portovenous phase obtained on 16 slice scanner at 75 sec after injection of 100 ml Omnipaque; 275 mA; 120 kV; 0.8 mm slice thickness