Dear Editor, we present here a case of a 55-year-old male with complaints of acute abdominal pain, localized predominantly in the right upper quadrant, nonradiating in nature associated with two to three episodes of emesis. He had a past surgical history of laparoscopic cholecystectomy done 4 years ago. His vitals and blood counts were normal. On examination, a focal irreducible hard lump of size approximately 3 × 4 cm was noted about 2 to 3 cm above from the umbilicus in the right paramedian location, which was tender, nonmobile, and nonpulsatile in nature. No other associated features were noted. Differential of acute etiology concerning with the liver and head of pancreas were considered with a suspicion of tumor. To characterize the lesion, ultrasound (USG) abdomen was performed, which showed bulky right rectus sheath compartment with herniating bowel loops and omentum through a defect of about 2.5 cm size in the right posterior rectus sheath in the supraumbilical location, as shown in [Fig. 1A–C]. The visualized afferent bowel loops were normal in caliber and echogenicity with no fluid in the hernial sac, as show in [Fig. 1D]. Thus, suggesting no symptoms of obstruction. However, patient's pain aggravated to severe extent the next day, with bloating and nonpassage of flatus, and was suspected to have developed obstruction. To confirm USG findings, a contrast-enhanced computed tomography (CT) abdomen was done, which illustrated similar findings, as shown in [Fig. 2A] and [B].
Fig. 1 Ultrasound (USG) images depicting posterior rectus sheath hernia. (A) USG image showing bulky right rectal sheath compartment (arrow head). (B) USG image showing bowel loop (solid arrow) in the bulky right rectus sheath compartment. (C) USG image showing herniating bowel loop (solid arrow), through a defect (measuring 2.5 cm; dotted line) in the posterior rectus sheath. (D) USG images showing nondilated afferent small bowel loops (dashed arrow).
Fig. 2 (A and B) Contrast-enhanced axial computed tomography (CT) images showing bulky right rectal sheath (dashed arrow) with herniating small bowel and omentum (solid arrow) through a defect (dotted line) in the posterior rectus sheath, pushing the right rectus muscle (single arrow head) anteriorly with upstream dilatation of small bowel loops (double arrow head). (C and D) Intraoperative images showing the herniation of small bowel loop, through an anterior abdominal wall defect, corroborating with findings on ultrasound (USG) and CT.
Patient was taken up for surgery immediately, during which ileal bowel loops and omental fat were seen between the right rectus abdominis muscle and posterior rectus sheath, as in [Fig. 2C] and [D]. Bowel loops were reduced and defect repaired with a mesh. Postoperatively, patient was stable and discharged after 4 days.
This case emphasizes the role of USG in diagnosing posterior rectus sheath hernia. It has been proposed that the individuals who develop this hernia have some sort of muscle weakness present earlier, which is further accentuated due to surgical incision/ trauma to the rectus abdominis muscle.[1]
[2] Other predisposing factors are increased abdominal pressure caused by obesity, ascites, and other causes.[1]
[3] Due to rarity of this condition, not many of the clinicians and radiologists are aware, consequently, such cases are usually neglected, or worked up as abdominal lumps, until they show up in emergency as complicated hernia with small bowel obstruction, incarceration, strangulation, bowel ischemia/infarction, or bowel perforation.[1]
[2] A timely diagnosis, as in our case, is cardinal for better prognosis, and having a high degree of suspicion is key in making the diagnosis. A well-aware radiologist with high level of suspicion in a case presenting with complaints and potential risk factors as discussed, can make a working diagnosis of this condition. A CT scan can be performed when in doubt, as it is more sensitive than USG in the identification of posterior rectus sheath defect.
