Variations and morphometric features of the vermiform appendix: A systematic review and meta-analysis of 114,080 subjects with clinical implications

The application value of high-frequency ultrasound in the feasibility assessment of endoscopic retrograde appendicitis therapy in children with appendicitis

Acute appendicitis is one of the common acute abdominal diseases in pediatrics. However, the implementation of radiological examination guided endoscopic retrograde appendicitis therapy (ERAT) in adults is limited in children. Our previous research explored the non-invasive guidance of high-frequency ultrasound (HFUS) for ERAT and achieved good therapeutic effects. This study mainly focuses on exploring the application value of HFUS in the feasibility assessment of ERAT in children with appendicitis. 163 children with appendicitis received ERAT guided by HFUS were analyzed retrospectively. According to the parameters evaluated by HFUS before and during ERAT, the results indicated that the distance between the appendix orifice and the ileocecal valve significantly affected the time required for the guidewire to enter the appendix cavity (P < 0.05). The diameter and the texture of the fecalith, the thickness of the intestinal wall of the appendiceal orifice all had significant effects on the successful removal of the fecalith (P < 0.05). The success rate, treatment time and final flushing effect of the guidewire to reach the blind end of the appendix were significantly affected by the tortuosity of the appendix and whether there was adhesion with surrounding tissues (P < 0.05). HFUS can accurately assess the feasibility of ERAT in children with appendicitis.

Does the length matter in acute appendicitis for the perforation risk?: A retrospective cohort study

It has been hypothesized that short appendices increase intraluminal pressure more rapidly and perforate more frequently than long appendices. Two hundred seventy-seven adult patients were retrospectively analyzed and underwent an appendectomy between January 2015 and August 2021. Data extracted from patient records included sex, age, time from admission to operation (hospital interval), weekday or weekend operation time, and operative and pathological findings. Operation was performed on 273 patients, of whom 178 (65.2%) were male and 95 (34.8%) female. The mean age of the male patients was 31.7 ± 08 (range 18-67), and that of the female patients was 38.9 ± 1.4 (range 18-78). Perforation was observed in 57 (20.9%) patients. Sex was not a factor in the development of perforation (P = .95). The mean age of the patients with and without perforation was 40.1 ± 2.2 and 32.7 ± 0.7, respectively. The perforation rate increased with age (P = .003). Appendix lengths were similar in both groups, and length was not a factor in the development of perforation (P = .83). This study found that the development of perforated appendicitis is not related to the length of the appendix. The risk of perforation increased with age.

A peculiar appendix: A case report

Introduction and importance

Acute appendicitis is a clinical diagnosis with marked variations in the clinical presentation, the latter resultant of varied anatomical positions of the appendix.

Presentation of case

Here we present the first documented case of the vermiform appendix located in the ascending colon of a young South Asian male who presented with right upper abdominal pain. The ultrasound scan of the abdomen failed to visualise the appendix in the right iliac fossa. Persistent symptoms despite conservative therapy and elevated inflammatory markers warranted an open laparotomy. The histology further confirmed acute appendicitis.

Clinical discussion

Atypical locations and congenital anomalies of the appendix are relatively rare entities. Appendicular duplication and hypoplasia are the predominant varieties of congenital anomalies. Caecal diverticula might mimic acute appendicitis despite the relative rarity and absence of all three layers of intestinal wall, which could be of use in distinguishing an abnormally located appendix.

Conclusion

Such deviations from the norm lead to atypical clinical and imaging findings where operative interventions might be required in place of non-operative care, especially in instances of persistent symptomatology.

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Human appendix has a variable course although congenital anomalies related to its position are rare

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Unusual anatomical positions lead to atypical presentations and negative/abnormal findings in appendicular pathology.

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Hypoplasia, agenesis, duplication, triplication and diverticular formation are rare congenital anomalies of the appendix.

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Appendix located in the ascending colon has never been reported in the English literature so far.

The Diagnostic Differentiation Challenge in Acute Appendicitis: How to Distinguish between Uncomplicated and Complicated Appendicitis in Adults

(1) Background: How to best define, diagnose and differentiate uncomplicated from complicated acute appendicitis remains debated. Hence, the aim of this review was to present an overview of the current knowledge and emerging field of acute appendicitis with a focus on the diagnostic differentiation of severity currently subject to ongoing investigations. (2) Methods: We conducted a PubMed search using the MeSH terms “appendicitis AND severity” and “appendicitis AND classification”, with a focus on studies calling appendicitis as ‘uncomplicated’ or ‘complicated’. An emphasis on the last 5 years was stressed, with further studies selected for their contribution to the theme. Further studies were retrieved from identified full-text articles and included per the authors’ discretion. (3) Results: The assumption that appendicitis invariably will proceed to perforation has been outdated. Both uncomplicated and complicated appendicitis exist with likely different pathophysiology. Hence, this makes it important to differentiate disease severity. Clinicians must diagnose appendicitis, but, in the next step, also differentiate between uncomplicated and complicated appendicitis in order to allow for management decisions. Diagnostic accuracy without supportive imaging is around 75–80% and, based on clinical judgement and blood tests alone, the negative appendectomy rate has been described as high as 36%. More research is needed on available biomarkers, and the routine use of imaging still remains debated. Scoring systems have the potential to improve diagnostic accuracy, but no scoring system has yet been validated for differentiating disease severity. Currently, no universally agreed definition exists on what constitutes a complicated appendicitis. (4) Conclusions: Uncomplicated and complicated appendicitis appear to have different pathophysiology and should be treated differently. The differentiation between uncomplicated and complicated appendicitis remains a diagnostic challenge.

The Critical Appraisal Tool for Anatomical Meta-analysis (CATAM): A framework for critically appraising anatomical meta-analyses

The hallmark of evidence-based medicine is the meta-analysis (MA). For much of its rich history, the field of anatomy has been dominated by descriptive, cadaveric studies. In the last two decades, quantitative measurements and statistical analyses have frequently accompanied such studies. These studies have directly led to the publication of anatomical MAs, which have ushered in the exciting field of evidence-based anatomy. Although critical appraisal tools exist for clinical MAs, none of them are specifically tailored for anatomical MAs. Therefore, the purpose of this paper is to provide a framework by which clinical anatomists and others can critically appraise anatomical MAs using the Critical Appraisal Tool for Anatomical Meta-analysis (CATAM). Using a running example from a recently published MA, we show how to use the CATAM rubric in a step-by-step fashion. Each scored section of the CATAM rubric is summated into a total score (maximum 50 points). This score is then referenced to a conversion chart, which assigns a qualitative value to the MA in a range from "very good" to "poor." Future studies can investigate the interrater reliability of the instrument, and possibly subject the CATAM rubric to a Delphi panel. As anatomical MAs become more commonplace at surgical grand rounds and journal clubs in academic medical centers throughout the world, we hope that the CATAM rubric can help facilitate meaningful discussions about the quality and clinical relevance of anatomical MAs. This article is protected by copyright. All rights reserved.

Classification of acute appendicitis (CAA): treatment directed new classification based on imaging (ultrasound, computed tomography) and pathology

PURPOSE

Acute appendicitis (AA) is amongst the most common causes of acute abdominal pain. In spite of progress based on risk stratifications, "negative" appendectomies are performed in up to 30% of patients whilst the appendix perforates in others. Preoperative classification of AA based on imaging is therefore recommended. The aim was to classify AA based on imaging (ultrasound/US, computed tomography/CT), surgical pathology, and/or histopathology in order to differentiate between complicated and uncomplicated AA. A new classification of acute appendicitis (CAA) shall be illustrated by typical US and CT images and be employed in a diagnostic and therapeutic algorithm.

METHODS

Medline, Embase, and the Cochrane Library were searched. Any study after 1970, which investigated clinical scores, pathology, US, CT, magnetic resonance imaging, and treatment of AA, was included. Typical images were taken from the author's image database.

RESULTS

Five main types of AA are defined, normal appendix (type 0), nonvisualised appendix (type X), uncomplicated AA (type 1), complicated AA without perforation (type 2), and complicated AA with perforation (type 3). The imaging modality is indicated by an additional letter, e.g., type p3b for free perforation on pathology. Standardised reporting of the appendix evaluation by US and CT is presented, as well as algorithms for AA management. Imaging features indicating imminent perforation, as well as likely recurrence, were both classified as complicated AA.

CONCLUSION

Imaging is mandatory in suspected AA. The CAA clearly separates uncomplicated from complicated forms of AA allowing nonoperative management in selected patients with uncomplicated forms of AA.

Variant Anatomy and Its Terminology

Variant anatomy, which is an integral part of anatomical science, is related to abnormalities in the human body structure. Our understanding of variant anatomy is based on thousand years of anatomical experience. These abnormalities generally do not interfere with the function of the human body and do not typically manifest as pathological nosological units. However, under certain conditions, these abnormalities can worsen existing pathological states or even evoke new ones. Understanding variant anatomy is a basic skill not only of mere anatomists, but also of clinicians who work in fields involving both diagnostic techniques and therapeutic interventions. To gain and retain a good knowledge of the most frequent and clinically relevant anatomical variations, a simple, clear, and exactly defined nomenclature of variant structures is needed. A list of items comprising variant anatomy, which have been incorporated into the internationally accepted nomenclatures Terminologia Anatomica (1998) and Terminologia Neuroanatomica (2017), is described and analyzed. Examples of the most common anatomical variations related to terminology are mentioned, and variant anatomy as a whole and its role in understanding current anatomy are discussed.

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.

The Borderline-Size Appendix: Grayscale, Color Doppler, and Spectral Doppler Findings That Improve Specificity for the Sonographic Diagnosis of Acute Appendicitis

Diagnostic criteria for acute appendicitis using graded compression sonography have been well established based on the maximum outer diameter (MOD) of the appendix, with MOD values of <6 mm nearly always indicating normal appendices and MOD values of >8 mm nearly always indicating appendicitis. However, the "borderline-size" appendix, meaning one whose MOD lies between these ranges (ie, an appendix with MOD of 6-8 mm), presents a diagnostic dilemma because appendices in this size range are neither clearly normal nor abnormal when diagnosis is based on the MOD alone; accordingly, such borderline MOD values are diagnostically equivocal, and sonographic diagnosis must rely on sonographic findings other than the MOD. The goal of this review was to examine the additional sonographic findings that can add specificity and help enable an accurate diagnosis to be made in patients with borderline-size appendices.

Appendix muscle bands, a forgotten entity

INTRODUCTION

Appendix muscle bands (AMB) develop from the appendix muscle layer into the mesoappendix. There are few recent publications on this forgotten entity. The objectives of this study were to assess the morphological features of AMB as detected at microscopy examination of appendectomy specimens.

METHODS

Sixty-six cases of AMB as detected on appendectomy specimens were assessed for microscopy features on routine hematoxilin and eosin stained tissue slides. The morphological features were analyzed with regard to the main clinico-pathological parameters.

RESULTS

AMBs were multiple in 35 cases. Most AMBs were located between the tip and cecal limit, 7 at the tip, and 1 at the cecal limit of the appendectomy specimen. Associated appendix lesions were: acute appendicitis, neuroma, mesoappendix cyst, muscle hiatus, and diverticulae (60,6,2,45, and 1, respectively). In 24 appendices, the AMB developed from the perihiatus muscle. Two microscopy types of AMBs were detected: muscle-AMB and mesoappendix-AMB.

CONCLUSION

AMB may be detected incidentally at microscopy of appendectomy specimens. Acute appendicitis was associated in most cases, independently on the microscopy type of AMB. Appendix abnormalities as neuroma, mesoappendix cyst, muscle hiatus, and diverticulae can be associated to AMBs.