Subhepatic Appendicitis: A Systematic Review of Clinical Presentation, Diagnostic Challenges, and Surgical Management

Subhepatic appendicitis (SHA) is a rare positional variant of appendicitis that frequently mimics hepatobiliary disease, leading to diagnostic confusion and delay. As published evidence is limited to case reports and small series, this systematic review aims to synthesize the clinical presentation, diagnostic pathways, management, and outcomes of reported SHA cases. Following an International Prospective Register of Systematic Reviews (PROSPERO)-registered protocol, PubMed, Scopus, and Google Scholar were searched up to 6 May 2024, with additional eligible reports identified through manual searching and citation chaining. The data extracted were summarized descriptively, and the risk of bias was assessed using the Joanna Briggs Institute tools. Eighty-eight publications (78 case reports, 10 series) describing 97 patients were included. The median age was 29 years, and most patients were adults (71%) and male (69%). Right hypochondriac pain was the predominant symptom (82%), often accompanied by vomiting and fever. Ultrasound identified SHA in roughly one-quarter of cases, whereas CT did so reliably in most cases (81%), improving diagnostic certainty. Nearly all patients underwent surgery, with laparoscopy attempted in about half and occasional conversion to open appendectomy. Intraoperative findings commonly included adhesions, perforation, or abscess. Outcomes were generally favorable, with only a single death reported. A subset of cases demonstrated congenital anomalies such as an undescended cecum, short ascending colon, or malrotation, accounting for the aberrant appendiceal positioning. Clinicians should consider SHA in patients with right hypochondriac pain and inconclusive hepatobiliary investigations. CT improves detection, and timely operative management, often laparoscopic, leads to favorable outcomes.