Fecal loading in the cecum as a new radiological sign of acute appendicitis

Neuroendocrine apendicopathy in morphologically normal appendices of patients with diagnosis of acute appendicitis: Diagnostic study

Background

About 15%–25% of appendices removed to treat acute appendicitis present normal macro- and macroscopic morphology. The objective of this study was to verify an association of proinflammatory, neuroendocrine and immune mediators with morphologically normal appendices removed from patients with clinical laboratorial and imaging characteristics of acute appendicitis.

Materials and methods

Appendices removed from 121 adult patients of both genders were distributed into three groups according to their following characteristics: group 1: 53 macro- and microscopically normal appendices from patients with clinical, laboratorial and imaging diagnosis of acute appendicitis; group 2: 24 inflamed appendices from patients with clinical, laboratorial, imaging and histopathological diagnosis of acute appendicitis; group 3: 44 normal appendices from patients submitted to right colectomy to treat localized ascending colon adenocarcinoma. All appendices were immunohistochemically studied for gastrin inhibitor peptide, mast cell tryptase, vascular endothelial growth factor; intestinal vasoactive peptide, tumor necrosis factor alpha, interleukin 1, prostaglandin E2, gene-protein product 9.5, CD8 T lymphocytes, synaptophysine, enolase, and S100 protein.

Results

The group 1 revealed increased levels of synaptophysine, enolase, mast cell tryptase and PGP-9.5 comparing with the other two groups. The group 2 presented increased levels of interleukin 1, CD8 T lymphocytes and prostaglandin E2 comparing with the other two groups. The group 3 confirmed the normal levels of all these neuroendocrine, immune and proinflammatory mediators.

Conclusions

Morphologically normal appendices removed from patients with clinical and complementary exams indicating acute appendicitis have appendicular neuroimmunoendocrine disorder associated with the mediators synaptophysin, enolase, mast cell-related tryptase and gene-protein product 9.5.

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15 % to 25% of the appendices removed to treat acute appendicitis have normal appearance with no inflammatory signs.

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All patients with normal appendices removed due to acute appendicitis do not present similar clinical manifestation anymore.

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Inflammatory and neuroendocrine appendicopathies present similar clinical laboratorial and imaging characteristics.

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Morphologically normal appendices removed from patients indicating acute appendicitis have neuroimmunoendocrine disorders.

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Synaptophysin, enolase, mast cell tryptase and gene-protein product 9.5 are associated with neuroimmunoendocrine disorders.

Neuroimmunoendocrine peptides on inflammed and morphologically normal appendices removed due to clinical acute appendicitis

INTRODUCTION

Despite clinical characteristics and complementary exams indicate acute appendicitis, 15% to 40% of all appendectomies result in removal of appendices with normal macro- and micromorphological aspects. Even so, manifestations of acute abdomen disappear immediately after the appendectomy, and never show back again.

OBJECTIVE

To assess changes of neuroimmunoendocrine peptides on removed appendices due to clinical presentation of acute appendicitis.

METHOD

This article presents an updated revision of acute appendicitis, based on references found on PUBMED, LILACS, MEDLINE, WHOLIS and SciELO, using key words "acute appendicitis", "neuroimmune appendicitis", "neurogenic appendicopathy", and "incidental appendectomy".

RESULTS

Fourteen neuropeptides were analyzed by different authors who suggested the presence of neurogenic appendicopathy in morphologically normal appendices removed from patients with clinical presentation suggesting acute appendicitis.

CONCLUSION

The etiopathogeny of acute appendicitis continues to be unknown, and there is a great possibility that patients with morphologically normal appendices with clinical presentation of acute appendicitis that heal after appendectomy present a neuroimmunoendocrine disease.

Accuracy of the new radiographic sign of fecal loading in the cecum for differential diagnosis of acute appendicitis in comparison with other inflammatory diseases of right abdomen: a prospective study

RATIONALE

To assess the importance of the new radiographic sign of faecal loading in the cecum for the diagnosis of acute appendicitis, in comparison with other inflammatory diseases, and to verify the maintenance of this radiographic sign after surgical treatment of appendicitis.

METHODS

470 consecutive patients admitted to the hospital due to acute abdomen were prospectively studied: Group 1 [n=170]--diagnosed with acute appendicitis, subdivided into: Subgroup 1A--[n=100]--submitted to an abdominal radiographic study before surgical treatment, Subgroup 1B--[n=70]--patients who had plain abdominal X-rays done before the surgical procedure and also the following day; Group 2 [n=100]--right nephrolithiasis; Group 3 [n=100]--right acute inflammatory pelvic disease; Group 4 [n=100]--acute cholecystitis. The patients of Groups 2,3 and 4 were submitted to abdominal radiography during the pain episode.

RESULTS

The sign of faecal loading in the cecum, characterized by hypo transparency interspersed with multiple small foci of hyper transparent images, was present in 97 patients of Subgroup 1A, in 68 patients of Subgroup 1B, in 19 patients of Group 2, in 12 patients of Group 3 and in 13 patients of Group 4. During the postoperative period the radiographic sign disappeared in 66 of the 68 cases that had presented with the sign. The sensitivity of the radiographic sign for acute appendicitis was 97.05% and its specificity was 85.33%. The positive predictive value for acute appendicitis was 78.94% and its negative predictive value was 98. 08%.

DISCUSSION

The radiographic image of faecal loading in the cecum is associated with acute appendicitis and disappears after appendectomy. This sign is uncommon in other acute inflammatory diseases of the right side of the abdomen.

Diagnosis of acute appendicitis

Appendicitis is the most common abdominal emergency. While the clinical diagnosis may be straightforward in patients who present with classic signs and symptoms, atypical presentations may result in diagnostic confusion and delay in treatment. Abdominal pain is the primary presenting complaint of patients with acute appendicitis. Nausea, vomiting, and anorexia occur in varying degrees. Abdominal examination reveals localised tenderness and muscular rigidity after localisation of the pain to the right iliac fossa. Laboratory data upon presentation usually reveal an elevated leukocytosis with a left shift. Measurement of C-reactive protein is most likely to be elevated. The advances in imaginology trend to diminish the false positive or negative diagnosis. Radiographic image of faecal loading image in the caecum has a sensitivity of 97% and a negative predictive value that is 98%. In experienced hands, ultrasound may have a sensitivity of 90% and specificity higher than 90%. Helical CT has reported a sensitivity that may reach 95% and specificity higher than 95%. Despite all medical advances, the diagnosis of acute appendicitis continues to be a medical challenge.