eP600 - Acute Appendicitis Presenting as Right Upper Quadrant Pain

Purpose/Background: Appendicitis is one of the most commonly encountered general surgical emergencies worldwide. The anatomy of the appendix as well as the classical presentation of appendicitis are both well-documented in literature. However, aberrations in the position of the appendix can lead to difficulties in arriving at a diagnosis, resulting in delays in management. Appendicitis occurring in the subhepatic space is an uncommon phenomenon, accounting for 0.08% of all cases, and can mimic other conditions of the upper abdomen; therefore, a high index of suspicion of these anatomical variants is necessary in the prompt and safe management of such cases.Methods/Interventions: A 25-year-old female was admitted at the Emergency Department for a 2-day history of epigastric pain that migrated to the right upper quadrant. She did not experience nausea, fever, or loss of appetite. She had no significant medical history and no previous surgeries. Physical examination revealed direct right upper quadrant tenderness and a positive Murphy’s sign. Blood tests showed a normal white blood cell count and urinalysis was normal. A CT scan of the abdomen showed a dilated appendix, with surrounding fat stranding, its tip abutting the inferior border of the right liver lobe. The gallbladder wall was thickened at 0.4 cm but without intraluminal stones, or pericholecystic fluid collection. The patient underwent laparoscopic appendectomy using a 4-port setup. Intraoperatively, a suppurative appendix was seen with its tip projected towards the subhepatic area.Results/Outcomes: The patient had an uneventful postoperative course. Good wound healing and recovery was seen during her follow-up on postoperative days 7 and 30. Histology revealed acute suppurative appendicitis.Conclusion/

Discussion: The position of the appendix is highly variable. It appears most commonly in the retrocecal followed by the pelvic, subcecal, preileal, and postileal positions. Atypical locations of the appendix include the subhepatic, left-sided, intraherniary, lumbar, and mesocolic. A subhepatic appendix is often the result of midgut malrotation or a failure of descent of the midgut. Subhepatic acute appendicitis due to an arrest of cecal descent was first reported by King in 1955. Since then, there have only been a few cases described in literature with more reports of malrotation rather than arrest in cecal descent as the cause of the anatomical variation.Subhepatic appendicitis does not present in a classical manner and can be mistaken for a hepatobiliary, or gastric disease. Abdominal ultrasonography has a high probability of misdiagnosis in these cases. Contrast-enhanced CT scan is the best imaging modality in identifying subhepatic appendicitis.Once a diagnosis of subhepatic appendicitis has been made, its management must be contemplated. There is no internationally accepted consensus given its rare presentation. In the stable patient without peritonitis, laparoscopy is the preferred approach. Success in laparoscopic management requires a tailored approach – altering standard port positions, even placement of an additional port, to aid with optimal operative access.Subhepatic appendicitis is a rare surgical emergency that should be considered in a patient presenting with right upper quadrant pain. Due to its unique presentation, it becomes a challenge to diagnose and manage such cases in a timely manner. CT scan and laparoscopy are valuable tools in its management. Laparoscopic appendectomy can be carried out safely in these patients using a tailored approach in port placement.Contrast-enhanced abdominal CT scan images of a subhepatic appendicitis Figure 1. Contrast-enhanced abdominal CT scan (A) coronal oblique reconstruction showing a high-lying cecum (asterisk), the appendiceal base (arrowhead) and a dilated proximal appendix (arrow), coursing along the inferior margin of the liver, (B) axial view at the 2nd lumbar level showing the dilated subhepatic appendix (long arrow), (C) axial view at the 3rd lumbar level showing the appendiceal tip (short arrow) adjacent to the gallbladder (GB) fundus, (D) sagittal oblique reconstruction showing the appendix (long arrow) posterior to the gallbladder. PGH, 2023.