Is appendoscope a new option for the treatment of acute appendicitis?

Acute appendicitis is a common surgical emergency. It is commonly caused by obstruction of the appendiceal lumen due to fecaliths, tumors, or lymphoid hyperplasia. For over a century, appendectomy has been the primary treatment for acute appendicitis. Abraham Groves performed the first open appendectomy in 1883. In 1983, Kurt Semm completed the first laparoscopic appendectomy, heralding a new era in appendectomy. However, appendectomy is associated with certain complications and a rate of negative appendectomies. Studies have suggested controversy over the impact of appendectomy on the development of inflammatory bowel disease and Parkinson's disease, but an increasing number of studies indicate a possible positive correlation between appendectomy and colorectal cancer, gallstones, and cardiovascular disease. With the recognition that the appendix is not a vestigial organ and the advancement of endoscopic te-chnology, Liu proposed the endoscopic retrograde appendicitis therapy. It is an effective minimally invasive alternative for treating uncomplicated acute appendicitis. Our team has developed an appendoscope with a disposable digital imaging system operated through the biopsy channel of a colonoscope and successfully applied it in the treatment of appendicitis. This article provides an overview of the progress in endoscopic treatment for acute appendicitis and offers a new perspective on the future direction of appendiceal disease treatment.

Low-grade appendiceal mucinous neoplasms: Histomorphological spectrum in a tertiary care hospital.

BACKGROUND: Low-grade appendiceal mucinous neoplasms (LAMNs) are benign non-invasive epithelial proliferations of the appendix. These usually present clinically as mucoceles and these rarely exceed 2 cm in diameter. Lesions confined to the lumen are labelled as LAMN; however those in which mucin spreads outside the peritoneum are labeled as pseudomyxoma peritonei (PMP). AIMS AND OBJECTIVE: A retrospective study was conducted over a period of three years and all cases of appendectomies were studied. Twelve cases of LAMN were identified, which is a diagnostic dilemma for the pathologists and clinicians. RESULTS: LAMN was identified based on the histopathological features. Out of the 12 cases, 9 were classified as LAMN and 3 as appendiceal neoplasm with PMP. There was villous or flat proliferation of epithelial lining, loss lymphoid aggregates, and dissecting mucin within muscularis. CONCLUSION: LAMNs are rare neoplasms of the appendix, with clinical presentation similar to acute appendicitis. Mucinous collections within the appendiceal wall should be extensively searched for mucosal changes and, if found, should prompt a careful search for pushing invasion of LAMNs. A thorough and vigilant gross examination can be of great help. Appendicectomy is the treatment of benign and grossly intact mucinous neoplasm.

Culture-based bacterial evaluation of the appendix lumen and antibiotic susceptibility of acute appendicitis in Japan: A single-center retrospective analysis.

The question of whether to perform an appendectomy or conservative treatment for acute appendicitis can differ depending on the facility or surgeon, but antibiotic treatment is administered regardless of whether an appendectomy or conservative treatment is selected. We investigated the contemporary bacteriology for acute appendicitis and evaluated the antibiotic sensitivity of the bacteria that are currently associated with appendicitis. We retrospectively analyzed the bacterial culture results and antibiotic susceptibility of 141 patients who underwent appendicitis surgery, including the identification and antimicrobial susceptibility of the cultured bacteria within the excised appendices. Bacterial cultures were positive in 131 cases (92.9%). The most commonly isolated bacteria were Escherichia coli (90 isolates, 66.7%), followed by Enterococcus species (n = 19, 14.5%), Pseudomonas aeruginosa (n = 18, 13.7%), Streptococcus species (n = 15, 11.5%), and Klebsiella species (n = 8, 6.1%). Eight strains (8.8%) of E coli were extended-spectrum ß-lactamase producers, and ten strains (11.1%) were fluoroquinolone-resistant. Tazobactam/piperacillin and meropenem inhibited the growth of 100% of the major identified bacteria. The patients with appendicoliths had a significantly higher bacterial culture rate. Enterococcus species were frequently isolated from the patients with complicated appendicitis. For the antibiotic treatment of appendicitis, it is essential to understand the patient's microbiological profile and antibiotic susceptibilities. Research from Asian countries such as Japan can enhance our knowledge of regional antibiotic resistance patterns and inform effective treatment strategies.

Mucocoele of the appendix.

Introduction: Mucocoele of the appendix occurs in 0.2-0.7% of people in the world without any well-defined clinical symptoms. It occurs when there is an accumulation of mucous in the lumen of the appendix. Case Presentation: We present three cases: a 48-year-old male admitted to the emergency room with a one-day history of right iliac fossa pain. Abdominal examination was suggestive of acute appendicitis. The initial abdominal computerised tomography scan was reported as being unremarkable. At surgery, a firm tumour of the appendix was found, and a limited right hemicolectomy was done. Histopathology confirmed a mucocoele of the appendix with borderline mucinous histology.The second case is a 63-year-old man who presented with a one-year history of abdominal distension and weight loss. Previous abdominal ultrasound was suggestive of liver cirrhosis with significant ascitic fluid. Abdominal magnetic resonance imaging found an appendix mucocoele with infiltration of the omentum and scalloping of the liver surface suggestive of pseudomyxoma peritonei. A percutaneous biopsy of the omental mass confirmed metastatic mucinous adenocarcinoma of the appendix.The third case is a 68-year-old man who, during an annual medical check-up, had an incidental finding of a cystic right iliac fossa mass on ultrasound, confirmed on abdominopelvic computerised tomography scan to be an appendix mucocele. He had laparoscopic appendicectomy. The histopathological diagnosis confirmed a mucinous cystadenoma of the appendix. Conclusion: Preoperative diagnosis of appendiceal mucocoele is difficult and commonly discovered intraoperatively. The prognosis is good for the histologically benign type, but it is poor when malignant or peritoneal lesions are present. Funding: None declared.

MAIT cell activation and recruitment in inflammation and tissue damage in acute appendicitis.

Mucosal-associated invariant T (MAIT) cells are antimicrobial T cells abundant in the gut, but mechanisms for their migration into tissues during inflammation are poorly understood. Here, we used acute pediatric appendicitis (APA), a model of acute intestinal inflammation, to examine these migration mechanisms. MAIT cells were lower in numbers in circulation of patients with APA but were enriched in the inflamed appendix with increased production of proinflammatory cytokines. Using the patient-derived appendix organoid (PDAO) model, we found that circulating MAIT cells treated with inflammatory cytokines elevated in APA up-regulated chemokine receptors, including CCR1, CCR3, and CCR4. They exhibited enhanced infiltration of Escherichia coli-pulsed PDAO in a CCR1-, CCR2-, and CCR4-dependent manner. Close interactions of MAIT cells with infected organoids led to the PDAO structural destruction and death. These findings reveal a previously unidentified mechanism of MAIT cell tissue homing, their participation in tissue damage in APA, and their intricate relationship with mucosal tissues during acute intestinal inflammation in humans.

Immunoglobulin G4-related disease mimicking an appendiceal neoplasm: a case report.

Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition characterized by chronic activation of the immune system and a tendency to form tumorous lesions. IgG4-RD is frequently characterized by the presence of tumor-like masses affecting multiple organs and is easily mistaken for a malignant neoplasm. However, IgG4-RD affecting the appendix is extremely rare, with only seven cases reported previously. We report the case of a woman in her early 60s who presented with insidious abdominal pain and radiological findings mimicking appendiceal neoplasms. After diagnosing appendiceal neoplasms, surgery was performed. The patient had a serum IgG4 concentration of <1.35 g/L, which did not satisfy one of the three revised comprehensive diagnostic criteria for IgG4-RD. A pathological examination was conducted, and the patient was diagnosed with appendiceal IgG4-RD. To the best of our knowledge, there have been no previously reported cases of IgG4-RD affecting the appendix in patients with low serum IgG4 concentrations. This report may prove beneficial for the future understanding of IgG4-RD and for the revision of diagnostic and treatment strategies.

Schistosomal appendicitis: a case report.

BACKGROUND: Schistosomiasis is one of the endemic parasitic diseases in many developing countries. Despite this, appendicitis secondary to schistosomiasis is an uncommon condition even in some endemic areas. Schistosomal appendicitis, an incidentally discovered appendicitis associated with schistosomiasis histological findings, affects young males predominantly. Timely diagnosis and treatment, including appendectomy and anti-helminthic therapy, are crucial. CASE REPORT: A 24-year-old Sudanese male patient presented with abdominal pain. Diagnosed with acute appendicitis, he underwent appendectomy, revealing appendix inflammation with Schistosoma ova in histopathology. Abdominal ultrasound detected no complications. Weakly positive Schistosoma serology was noted, but stool and urine analysis showed no infection evidence. Prescribed praziquantel, patient had 3-year post-op follow-up without complications. CONCLUSIONS: This case report underscores the significance of including schistosomiasis in the differential diagnosis of appendicitis, particularly in regions where the disease is endemic. It underscores the necessity of histopathological evaluations for accurate diagnosis, emphasizing the potential implications for clinical practice in similar settings.

Introducing the ratio of cross diameters of the appendix for ultrasound diagnosis of acute appendicitis can significantly increase specificity.

PURPOSE: To validate whether the introduction of the ratio of the cross diameters on the transverse section of the appendix (RATIO) ≤ 1.18 is useful for improving the ultrasound diagnosis of acute appendicitis (AA). METHODS: Data from 220 patients with AA and 110 patients with a normal appendix were retrospectively studied. The RATIO ≤ 1.18, maximal outer diameter (MOD) > 6 mm, and a combination of RATIO ≤ 1.18 and MOD > 6 mm were used for predicting AA. The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated. RESULTS: The RATIO ≤ 1.18, MOD > 6 mm, and a combination of RATIO ≤ 1.18 and MOD > 6 mm for predicting AA showed a sensitivity of 90, 100, and 90%; specificity of 79.1, 27.3, and 88.2%; and AUC of 0.845, 0.636, and 0.891, respectively. When comparing the outcomes between MOD > 6 mm and a combination of MOD > 6 mm and RATIO ≤ 1.18, the specificity and PPV increased from 27.3 to 88.2% and 73.3 to 93.8%, respectively (all P < 0.0001). The sensitivity and NPV decreased from 100 to 90% and 100 to 81.5%, respectively (all P < 0.0001). The AUC increased from 0.636 to 0.891 (P < 0.0001). When comparing the AUC of MOD > 6 mm, and a combination of RATIO ≤ 1.18 and MOD > 6 mm for predicting AA with the AUC in a previous study, there were no significant differences between each other (all P > 0.05). CONCLUSION: Introducing the RATIO ≤ 1.18 for the evaluation of AA can improve the diagnostic performance and significantly increase specificity.

Partial visualization of appendix on ultrasound: What does it mean in the child with suspected appendicitis?

BACKGROUND: Visualization of the entire appendix, including the tip, is thought, but has not been demonstrated, to be important for exclusion of appendicitis by ultrasound. OBJECTIVE: To determine if incomplete visualization of the appendix has negative clinical ramifications including missed appendicitis. METHODS: Under IRB approval we retrospectively reviewed right lower quadrant ultrasound reports from January 2017 to December 2020 to identify examinations with impressions of full visualization of the normal appendix, non-visualization of the appendix with and without secondary findings of appendicitis, and partial visualization of the appendix. Electronic health records were reviewed for follow-up imaging within 48 h, and surgery with pathology reports (if available). RESULTS: 12,193 examinations were included. 4171 (34.2 %) had full visualization of a normal appendix, 5369 (44.0 %) had non-visualization with no secondary findings, and 234 (1.9 %) had non-visualization with secondary findings, The frequencies of appendicitis in these three groups were 34 (0.8 %), 283 (5.3 %), and 127 (54.3 %) respectively. The appendix was partially visualized in 338 (2.8 %) patients with secondary findings present in 53 (15.6 %). Partial visualization without secondary findings had a similar frequency (4.9 %, 14/285) of appendicitis to non-visualized appendix without secondary findings (p = 0.797) and a higher frequency than full visualization of a normal appendix (p < 0.0001). Partial visualization with secondary findings had similar rates (54.7 %, 29/53) to non-visualized appendix with secondary findings (p = 0.953). CONCLUSION: Partial visualization of the appendix with ultrasound (with and without secondary findings) is associated with similar frequencies of appendicitis as non-visualization of appendix (with and without secondary findings).

Predictive values of indirect ultrasound signs for low risk of acute appendicitis in paediatric patients without visualisation of the appendix on ultrasound.

BACKGROUND AND OBJECTIVES: The ability to rule appendicitis in or out using ultrasound is limited by studies where the appendix is not visualised. We determined whether the absence of indirect ultrasound signs can rule out appendicitis in children undergoing a radiology-performed ultrasound in which the appendix is not visualised METHODS: This was a single-centre retrospective observational study of patients aged 3-13 with a clinical suspicion of acute appendicitis evaluated in a Paediatric Emergency Department in Spain from 1 January 2013 to 31 December 2019. For those patients who had formal ultrasound, direct and indirect findings of ultrasound were abstracted from the ultrasound report. The surgical pathology report was established as the gold standard in patients who underwent an appendectomy. In those who did not, appendicitis was considered not to be present if there was no evidence in their charts that they had undergone an appendectomy or conservative therapy for appendicitis during the episode. The main outcome variable was the diagnosis of acute appendicitis. For patients undergoing ultrasound, the independent association of each indirect ultrasound sign with the diagnosis of appendicitis in patients without a visualised appendix was analysed using logistic regression. RESULTS: We included 1756 encounters from 1609 different episodes. Median age at the first visit of each episode was 10.1 years (IQR, 7.7-11.9) and 921 (57.2%) patients were men. There were 730 (41.6%) encounters with an Alvarado score ≤3, 695 (39.6%) with a score 4-6 and 331 (18.9%) with a score ≥7. Appendicitis was diagnosed in 293 (17.8%) episodes. Ultrasonography was performed in 1115 (61.6%) encounters, with a visualised appendix in 592 (53.1%).The ultrasound findings independently associated with appendicitis in patients without a visualised appendix were the presence of free intra-abdominal fluid in a small quantity (OR:5.0 (95% CI 1.7 to 14.6)) or in an abundant quantity (OR:30.9 (95% CI 3.8 to 252.7)) and inflammation of the peri-appendiceal fat (OR:7.2 (95% CI 1.4 to 38.0)). The absence of free fluid and inflammation of the peri-appendiceal fat ruled out acute appendicitis in patients with an Alvarado score <7 with a sensitivity of 84.6% (95% CI 57.8 to 95.7) and a negative predictive value of 99.4% (95% CI 97.8 to 99.8). CONCLUSIONS: Patients with an Alvarado score <7 and without a visualised appendix on ultrasound but who lack free fluid and inflammation of the peri-appendiceal fat are at very low risk of acute appendicitis.

Predictive factors for recurrent acute appendicitis after conservative treatment.

INTRODUCTION: Conservative treatment of acute appendicitis is gaining popularity, and identifying patients with a higher risk of recurrence is becoming increasingly important. Previous studies have suggested that older age, male sex, diabetes, appendicolith and abscess formation may be contributing factors, however, results from the adult population are inconsistent. AIM: This study aims to identify predictive factors for recurrent appendicitis after conservative treatment. METHODS: This retrospective study included patients with conservatively treated acute appendicitis at Skåne University Hospital, Sweden during 2012-2019. Information on patient demographics at index admission and follow-up data were retrieved from medical charts and radiologic images. Uni -and multivariable logistic regression analysis were performed using Stata Statistical Software. RESULTS: In total, 379 patients with conservatively treated acute appendicitis were identified, of which 78 (20.6%) had recurrence. All patients were followed-up for a minimum of 41 months after the first diagnosis of acute appendicitis unless appendectomy after successful conservative treatment or death occurred during follow-up. The median time to recurrence was 6.5 (1-17.8) months. After multivariable logistic regression analysis, external appendix diameter >10 mm [OR 2.4 (CI 1.37-4.21), p = .002] and intra-abdominal abscess [OR 2.05 (CI 1.18-3.56), p = .011] on computed tomography were significant independent risk factors for recurrent appendicitis. Appendicolith was not associated with an increased risk of recurrence. CONCLUSION: This study suggests abscess formation and appendix distension of >10 mm to be potential risk factors for recurrent acute appendicitis after initial successful conservative treatment.

Nodular image in the appendix observed on ultrasound: endometriosis or neuroendocrine neoplasia?

Objective: To evaluate the association between clinical and imaging with surgical and pathological findings in patients with suspected neuroendocrine tumor of appendix and/or appendix endometriosis. Methods: Retrospective descriptive study conducted at the Teaching and Research Institute of Hospital Israelita Albert Einstein, in which medical records and databases of patients with suspected neuroendocrine tumor of appendix and/or endometriosis of appendix were analyzed by imaging. Results: Twenty-eight patients were included, all of which had some type of appendix alteration on the ultrasound examination. The pathological outcome of the appendix found 25 (89.3%) lesions compatible with endometriosis and three (10.7%) neuroendocrine tumors. The clinical findings of imaging and surgery were compared with the result of pathological anatomy by means of relative frequency. Conclusion: It was possible to observe a higher prevalence of appendix endometriosis when the patient presented more intense pain symptoms. The image observed on ultrasound obtained a high positive predictive value for appendicular endometriosis.

Pathologic Analysis of Twenty-one Appendices From Children With Multisystem Inflammatory Syndrome Compared to Specimens of Acute Appendicitis: A Cross-sectional Study.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a rare, severe complication of coronavirus disease 2019, commonly involving the gastrointestinal tract. Some children with MIS-C undergo appendectomy before the final diagnosis. There are several hypotheses explaining the pathomechanism of MIS-C, including the central role of the viral antigen persistence in the gut, associated with lymphocyte exhaustion. We aimed to examine appendectomy specimens from MIS-C patients and assess their pathologic features, as well as the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens. METHODS: In this cross-sectional study we included 21 children with MIS-C who underwent appendectomy. The control group included 21 sex- and age-matched children with acute appendicitis (AA) unrelated to SARS-CoV-2 infection. Histologic evaluation of appendiceal specimens included hematoxylin and eosin staining and immunohistochemical identification of lymphocyte subpopulations, programmed cell death protein-1 (PD-1) and SARS-CoV-2 nucleocapsid antigen. RESULTS: Appendices of MIS-C patients lacked neutrophilic infiltrate of muscularis propria typical for AA (14% vs. 95%, P < 0.001). The proportion of CD20+ to CD5+ cells was higher in patients with MIS-C (P = 0.04), as was the proportion of CD4+ to CD8+ (P < 0.001). We found no proof of SARS-CoV-2 antigen presence, nor lymphocyte exhaustion, in the appendices of MIS-C patients. CONCLUSIONS: The appendiceal muscularis of patients with MIS-C lack edema and neutrophilic infiltration typical for AA. SARS-CoV-2 antigens and PD-1 are absent in the appendices of children with MIS-C. These findings argue against the central role of SARS-CoV-2 persistence in the gut and lymphocyte exhaustion as the major triggers of MIS-C.

Pathological Assessment of the Appendix in Appendectomies Performed in Children.

BACKGROUND: Acute appendicitis is known as the most common diagnosis of acute abdomen leading to surgery. Therefore, timely diagnosis is of special importance. This study was conducted with the aim of pathological assessment of the appendix in appendectomies performed in children to determine the rate of negative appendectomies and the predictors of negative appendectomy and to evaluate the paraclinical tools used in the diagnosis of acute appendicitis. METHODS: This is a cross-sectional descriptive study. All children who underwent appendectomy at Shahid Motahari Hospital in Urmia from March 2021 to March 2022 were examined. The required data including demographic, paraclinical, and final pathology characteristics were collected and recorded. The investigated cases were classified into positive and negative appendectomy categories for comparison. RESULTS: Among 234 pathology samples of the appendix, 22 cases were related to accidental appendectomy. In addition, 11.3% of cases were negative appendectomy and 88.7% were positive appendectomy. The age range of 8 to 14 years and male gender were associated with a lower negative appendectomy rate (both P<0.001). Inflammatory (49.5%) and gangrenous appendicitis (30.2%) were the most commonly reported histopathologies. Sonography had a sensitivity of 84%, a specificity of 79%, and an overall diagnostic accuracy of 83%. CONCLUSION: A relatively significant number of accidental and negative appendectomies are performed. More careful investigation and the use of expectant and medical treatment instead of surgery, especially in females and young children, can be effective in improving diagnostic accuracy and preventing negative appendectomies.

The microbiome of the appendix differs in patients with and without appendicitis: A prospective cohort study.

BACKGROUND: Appendicitis seems to be a disease of infectious origin, but the detailed pathogenesis is unknown. We aimed to investigate the microbiome of the appendix lumen in patients with and without appendicitis, including a comparison of the subgroups of complicated versus uncomplicated appendicitis. METHODS: This prospective observational cohort study included adult patients undergoing laparoscopic appendectomy for suspected appendicitis. According to histopathologic findings, the investigated groups consisted of patients with and without appendicitis, including subgroups of complicated versus uncomplicated appendicitis based on the surgical report. A swab of the appendix lumen was analyzed for genetic material from bacteria with shotgun metagenomics, and outcomes included analyses of microbiome diversity and differential abundance of bacteria. RESULTS: A total of 53 swabs from patients with suspected appendicitis were analyzed: 42 with appendicitis (16 complicated) and 11 without appendicitis. When comparing patients with and without appendicitis, they were equally rich in bacteria (alpha diversity), but the microbiome composition was dissimilar between these groups (beta diversity) (P < .01). No consistent bacterial species were detected in all patients with appendicitis, but a least 3 genera (Blautia, Faecalibacterium, and Fusicatenibacter) and 2 species, Blautia faecis and Blautia wexlerae, were more abundant in patients without appendicitis. For the subgroups complicated versus uncomplicated appendicitis, both measures for microbiome diversity were similar. CONCLUSION: The appendix microbiome composition of genetic material from bacteria in adult patients with and without appendicitis differed, but the microbiome was similar for patients with complicated versus uncomplicated appendicitis. Trial registration NCT03349814.