Appendicitis is the most prevalent surgical emergency. The negative appendicectomy rate and diagnostic uncertainty are important concerns. This study aimed to assess the effectiveness of current appendicitis risk prediction models in patients with acute right iliac fossa pain.

A nationwide prospective observational study was conducted, including all consecutive adult patients who presented with right iliac fossa pain. Diagnostic, clinical and negative appendicectomy rate data were recorded. The Alvarado score, Appendicitis Inflammatory Response (AIR), Raja Isteri Pengiran Anak Saleha Appendicitis (RIPASA) and Adult Appendicitis Score systems were calculated with collected data to classify patients into risk categories. Diagnostic value and categorization performance were evaluated, with use of risk category-based metrics including 'true positive rate' (percentage of appendicitis patients in the highest risk category), 'failure rate' (percentage of patients with appendicitis in the lowest risk category) and 'categorization resolution' (true positive rate/failure rate).

A total of 3358 patients from 84 centres were included. Female patients were less likely to undergo surgery than men (71.5% versus 82.5% respectively; relative risk 0.866, 95% c.i. 0.834 to 0.901, P < 0.001); with a three-fold higher negative appendicectomy rate (11.3% versus 4.1% respectively; relative risk 2.744, 95% c.i. 2.047 to 3.677, P < 0.001). Ultrasonography was utilized in 56.8% and computed tomography in 75.2% of all patients. The Adult Appendicitis Score had the best diagnostic performance for the whole population; however, only RIPASA was significant in men. All scoring systems were successful in females patients, but Adult Appendicitis Score had the highest area under the receiver operating characteristic curve value. The RIPASA and the Adult Appendicitis Score had the best categorization resolution values, complemented by their exceedingly low failure rates in both male and female patients. Alvarado and AIR had extremely high failure rates in men.

The negative appendicectomy rate was low overall, but women had an almost three-fold higher negative appendicectomy rate despite lower likelihood to undergo surgery. The overuse of imaging tests, best exemplified by the 75.2% frequency of patients undergoing computed tomography, may lead to increased costs. Risk-scoring systems such as RIPASA and Adult Appendicitis Score appear to be superior to Alvarado and AIR.

Reports of an increased proportion of complicated appendicitis during the Covid-19 pandemic suggest a worse outcome due to delay secondary to the restrained access to health care, but may be explained by a concomitant decrease in uncomplicated appendicitis. We analyze the impact of the pandemic on the incidences of complicated and uncomplicated appendicitis.

We did a systematic literature search in the PubMed, Embase and Web Of Science databases on December 21, 2022 with the search terms (appendicitis OR appendectomy) AND ("COVID" OR SARS-Cov2 OR "coronavirus"). Studies reporting the number of complicated and uncomplicated appendicitis during identical calendar periods in 2020 and the pre-pandemic year(s) were included. Reports with indications suggesting a change in how the patients were diagnosed and managed between the two periods were excluded. No protocol was prepared in advance. We did random effects meta-analysis of the change in proportion of complicated appendicitis, expressed as the risk ratio (RR), and of the change in number of patients with complicated and uncomplicated appendicitis during the pandemic compared with pre-pandemic periods, expressed as the incidence ratio (IR). We did separate analyses for studies based on single- and multi-center and regional data, age-categories and prehospital delay.

The meta-analysis of 100,059 patients in 63 reports from 25 countries shows an increase in the proportion of complicated appendicitis during the pandemic period (RR 1.39, 95% confidence interval (95% CI 1.25, 1.53). This was mainly explained by a decreased incidence of uncomplicated appendicitis (incidence ratio (IR) 0.66, 95% CI 0.59, 0.73). No increase in complicated appendicitis was seen in multi-center and regional reports combined (IR 0.98, 95% CI 0.90, 1.07).

The increased proportion of complicated appendicitis during Covid-19 is explained by a decrease in the incidence of uncomplicated appendicitis, whereas the incidence of complicated appendicitis remained stable. This result is more evident in the multi-center and regional based reports. This suggests an increase in spontaneously resolving appendicitis due to the restrained access to health care. This has important principal implications for the management of patients with suspected appendicitis.

Ultrasound is an accurate tool for diagnosing acute appendicitis. Conservative treatment for uncomplicated acute appendicitis is feasible and safe in children. However, no sonographic follow-up results from children with nonoperatively managed acute appendicitis have been reported.

To describe the sonographic appearance of the appendix at follow-up ultrasound and to attempt to identify signs predictive of recurrent acute appendicitis.

Children diagnosed with uncomplicated acute appendicitis and treated conservatively in our hospital from 2014 to 2019, and who presented for follow-up ultrasound at 3, 6 and 9 months, were included in our study. Clinical, laboratory and ultrasound data were recorded.

By the end of follow-up, 29 (14.2%) of 204 children in the cohort had developed recurrent acute appendicitis and 175 had recovered uneventfully. On follow-up ultrasound, appendiceal diameter measured > 6 mm in 56/204 (27.5%) cases at 3 months and in 9/26 (34.5%) at 6 months. After 3 months, 102/204 (50%) children had normal appendiceal diameter on ultrasound. Appendiceal diameter > 6 mm was associated with intraluminal fluid or sludge in the appendiceal lumen at 3- and 6-month follow-up (P < 0.001, P = 0.002, respectively). Comparing cases with and without recurrence, at 3-month follow-up, appendiceal diameter > 6 mm was found in 17/29 (58.6%) cases vs. 39/175 (22.3%), respectively (P < 0.001). Appendiceal diameter returned to normal in 12/19 (63.2%) cases in the nonrecurrent acute appendicitis group compared with 2/7 (28.6%) in the recurrent acute appendicitis group (P = 0.05) at the 6-month follow-up. Intraluminal fluid or sludge was detected more frequently in the recurrent acute appendicitis versus the nonrecurrent acute appendicitis group at 3- (P < 0.001) and 6-month (P = 0.001) follow-up.

Progressive normalization of appendiceal diameter was noted on follow-up ultrasound. The prevalence of both appendiceal diameter > 6 mm and intraluminal fluid or sludge were found to be increased in children who later developed recurrent acute appendicitis. Ultrasound appears to be a useful tool for follow-up in children with conservatively treated uncomplicated acute appendicitis and possibly might help predict recurrence.

Background: Acute appendicitis is one of the most common emergencies in general surgery. The gold standard treatment is surgery. Complications may occur during or after an appendectomy. In addition to age, clinically important factors for the outcome after appendicitis seems to be the comorbidities and the stage of the appendicitis at the time of the operation. Large observational data describing these facts are missing. Methods: In this retrospective multicenter observational study, all inpatients over the age of 17 years with a diagnosis of acute appendicitis in 47 hospitals of the Clinotel Hospital Group between 2010 and 2017 were included. Results: A total of 19,749 patients with acute appendicitis were operated on. The number of patients with more than five secondary diagnoses has increased from 8.4% (2010) to 14.5% (2017). The number of secondary diagnoses correlates with the ages of the patients and leads to a significantly longer hospital stay. Computer tomography (CT) has gained in importance in recent years in the diagnosis of acute appendicitis. A total of 19.9% of patients received a CT in 2017. Laparoscopic appendectomy increased from 88% in 2010 to 95% in 2017 (p < 0.001). The conversion rate did not change relevant in the study period (i.e., 2.3% in 2017). Appendicitis with perforation, abscess, or generalized peritonitis was observed in 24.8% of patients. Mortality was 0.6% during the observation period and was associated with age and the number of secondary diagnoses. The analysis is based on administrative data collected primarily for billing purposes, subject to the usual limitations of such data. This includes partially incomplete clinical data. Conclusions: Multimorbidity is increasingly present in patients with acute appendicitis. Mortality is still in an acceptably low range with no increase. A CT scan is necessary for a precise diagnosis in unclear clinical situations to avoid unnecessary operations and was performed more often at the end of the study than at the beginning.

Being one of the most common causes of the acute abdomen, acute appendicitis (AA) forms the bread and butter of any general surgeon's practice. With the recent advancements in AA's management, much controversy in diagnostic algorithms, possible differential diagnoses, and weighing the management options has been generated, with no absolute consensus in the literature. Since Alvarado described his eponymous clinical scoring system in 1986 to stratify AA risk, there has been a burgeoning of additional scores for guiding downstream management and mortality assessment. Furthermore, advancing literature on the role of antibiotics, variations in appendicectomy, and its adjuncts have expanded the surgeon's repertoire of management options. Owing to the varied presentation, diagnostic tools, and management of AA have also been proposed in special groups such as pregnant patients, the elderly, and the immunocompromised. This article seeks to raise the critical debates about what is currently known about the above aspects of AA and explore the latest controversies in the field. Considering the ever-evolving coronavirus disease 2019 situation worldwide, we also discuss the pandemic's repercussions on patients and how surgeons' practices have evolved in the context of AA.

Acute appendicitis (AA) is the most common acute abdomen, and appendectomy is the most common nonelective surgery performed worldwide. Despite the long history of understanding this disease and enhancements to medical care, many challenges remain in the diagnosis and treatment of AA. One of these challenges is the timing of appendectomy. In recent decades, extensive studies focused on this topic have been conducted, but there have been no conclusive answers. From the onset of symptoms to appendectomy, many factors can cause delay in the surgical intervention. Some are inevitable, and some can be modified and improved. The favorable and unfavorable results of these factors vary according to different situations. The purpose of this review is to discuss the causes of appendectomy delay and its risk-related costs. This review also explores strategies to balance the positive and negative effects of delayed appendectomy.