SURGERY - ACUTE APPENDICITIS - DR. DANG NHU THANH - HUE UNIVERSITY OF MEDICINE AND PHARMACY

Epidemiology and Location of Appendicitis
📌 Appendicitis is one of the most common acute surgical emergencies, frequently leading to misdiagnosis, with up to 15% of cases potentially being misdiagnosed as something else (like gastroenteritis or Crohn's disease) or vice versa.
📌 The appendix's location is variable due to its developmental rotation; while typically in the right lower quadrant (RLQ), it can be retrocecal (behind the cecum), pelvic, or even in the left side if the colon is malrotated.
📌 The retrocecal appendix (occurring in about 3% to 15% of cases) may present with less pronounced peritoneal signs because the inflammation is less likely to irritate the anterior parietal peritoneum.

Pathophysiology and Obstruction
📌 The main cause of obstruction leading to appendicitis is often a fecalith (hardened stool mass), but in children, it can be due to lymphoid hyperplasia (which can double in size).
📌 Obstruction causes increased intraluminal pressure, leading to bacterial overgrowth, infection, and inflammation that spreads from the mucosa through the layers of the appendix wall and potentially to the peritoneum.
📌 The initial pain is typically periumbilical or epigastric due to visceral innervation; pain localizes to the RLQ later as the inflammation spreads to the parietal peritoneum.

Clinical Presentation and Diagnostic Challenges
📌 The classic triad of symptoms includes abdominal pain, gastrointestinal disturbance (nausea, vomiting, sometimes diarrhea), and signs of peritoneal irritation.
📌 Pain migration pattern is usually from epigastric/periumbilical area to the RLQ, though location depends heavily on the appendix's anatomical position (e.g., pelvic appendix causing hypogastric pain and tenesmus).
📌 Diagnostic challenges are significant in certain populations: children (cannot describe symptoms well, often present with concurrent GI upset), the elderly (atypical presentation, less fever, higher complication rates like perforation), and pregnant women (altered anatomy makes physical exam difficult, risk of non-therapeutic surgery).

Physical Examination and Specific Signs
📌 Specific maneuvers help localize pain based on anatomical position:
* Psoas sign: Pain upon passive extension of the right hip (suggests retrocecal appendix).
* Obturator sign: Pain upon internal rotation of the flexed right hip (suggests a pelvic appendix irritating the obturator internus muscle).
📌 Physical signs are less reliable when the appendix is retroperitoneal (e.g., retrocecal) because anterior peritoneal signs (like guarding) are absent or less pronounced unless perforation occurs.
📌 Differentiating between an appendiceal abscess and a phlegmon relies on palpation: an abscess often presents as a distinct, tender mass, whereas a phlegmon might be less defined.

Imaging and Differential Diagnosis
📌 Ultrasound (US) is a primary imaging tool, especially in Vietnam, which has better US capabilities for this pathology than some Western standards suggest, looking for signs like increased diameter ($>6 \text{mm}$) and periappendiceal fluid.
📌 CT scans are definitive when US is inconclusive, particularly for complex cases, though they should be used cautiously in pregnant women, especially in the first trimester.
📌 Key differentials to rule out include gastroenteritis, Meckel's diverticulitis, right-sided diverticulitis, and, in women of reproductive age, ectopic pregnancy or ovarian pathology (like torsion or tubo-ovarian abscess).

Management and Treatment Principles
📌 Uncomplicated appendicitis (non-perforated) is often treated surgically (laparoscopic), though non-operative management with antibiotics is an option in highly selected, uncomplicated cases, often reserved for elderly patients with high comorbidities.
📌 Post-operative recovery is swift for simple appendicitis (often one day hospitalization), but perforated appendicitis requires longer treatment, including broad-spectrum antibiotics and management of potential complications like adhesions or intra-abdominal abscesses.
📌 Early feeding post-surgery is encouraged; the old practice of prolonged fasting is outdated; patients should begin with clear liquids, progress to soft food, and ambulate early unless complicated perforation necessitates extended bowel rest.

Key Points & Insights
➡️ The location of the appendix is highly variable, necessitating a thorough physical exam that considers specific signs like the Psoas or Obturator sign to localize pain accurately.
➡️ Elderly patients present a major diagnostic challenge due to lower rates of fever and less distinct abdominal findings; they have a 5-fold higher mortality rate due to delayed diagnosis and perforation.
➡️ In pregnant women, appendicitis diagnosis is difficult due to anatomical shifts; early diagnosis is critical as perforation drastically increases the risk of premature labor.
➡️ While surgery is standard, non-operative management (antibiotics) is viable for selected, uncomplicated cases, especially in high-risk surgical candidates.

📸 Video summarized with SummaryTube.com on Mar 05, 2026, 16:21 UTC