The Global Incidence of Appendicitis: A Systematic Review of Population-based Studies

Risk of Appendicitis among Children with Different Piped Water Supply: A Nationwide Population-Based Study

Appendicitis is a common surgical condition for children. However, environmental effects, such as piped water supply, on pediatric appendicitis risk remain unclear. This longitudinal, nationwide, cohort study aimed to compare the risk of appendicitis among children with different levels of piped water supply. Using data from Taiwan Water Resource Agency and National Health Insurance Research Database, we identified 119,128 children born in 1996–2010 from areas of the lowest piped water supply (prevalence 51.21% to 63.06%) as the study cohort; additional 119,128 children of the same period in areas of the highest piped water supply (prevalence 98.97% to 99.63%) were selected as the controls. Both cohorts were propensity-score matched by baseline variables. We calculated the hazard ratios (HRs) and 95% confidence intervals (CIs) of appendicitis in the study cohort compared to the controls by Cox proportional hazards regression. The study cohort had a raised overall incidence rates of appendicitis compared to the control cohort (12.8 vs. 8.7 per 10,000 person-years). After covariate adjustment, the risk of appendicitis was significantly increased in the study cohort (adjusted HR = 1.46, 95% CI: 1.35, 1.58, p < 0.001). Subgroup and sensitivity analyses showed consistent results that children with low piped water supply had a higher risk of appendicitis than those with high piped water supply. This study demonstrated that children with low piped water supply were at an increased risk of appendicitis. Enhancement of piped water availability in areas lacking adequate, secure, and sanitized water supply may protect children against appendicitis.

Occurrence and Treatment of Pediatric Appendicitis in Finland 2004-2014

BACKGROUND

We aimed to investigate the trends in occurrence and the treatment approaches of appendicitis in Finnish children.

MATERIAL AND METHODS

All patients aged <16 y hospitalized for appendicitis in Finland in 2004-2014 were included. Data were retrospectively collected from the Finnish Care Register for Health Care and Statistics Finland.

RESULTS

Altogether 8494 children were hospitalized for appendicitis, with standardized incidence rate of 80.7 (95% confidence interval 79.0-82.0)/100,000 person years. The incidence rate of appendicitis decreased by 3.3% per year during the study period. Appendicitis was more common with increasing age, in boys compared to girls at 8 to 15 y of age, and during the summer compared to the other seasons. Most children (83.2%) were treated with conventional open appendectomy, but laparoscopic appendectomies were slowly increasing during the study period. The length of hospital stay (LOS) was shorter in boys than girls, in those treated laparoscopically, and in those with uncomplicated appendicitis. There was no significant seasonal variation in the LOS. However, the LOS decreased during the study period.

CONCLUSIONS

The incidence of pediatric appendicitis is decreasing, and there is a decreasing trend in LOS. While still relatively rare in the Finnish pediatric surgical centers, the use of laparoscopic appendectomy is increasing.

Mean platelet volume and the ratio of mean platelet volume to platelet count in the diagnosis of acute appendicitis

BACKGROUND

Mean platelet volume (MPV) is an inflammatory marker. Recent studies have shown that there is a negative correlation between platelet count (PC) and MPV and that the ratio of these two values may be more meaningful. The aim of our study was to investigate the diagnostic value of MPV and the MPV/PC ratio in acute appendicitis.

METHODS

Patients who were admitted to the emergency department and underwent appendectomy for acute appendicitis between January 2013 and May 2016 were evaluated retrospectively. The patients were divided into three groups based on their histopathological findings: the control group (negative appendicectomy) and the uncomplicated and complicated appendicitis groups. Leukocyte count, CRP (C-reactive protein) levels, PC, MPV and the MPV/PC ratio were compared among the groups.

RESULTS

A total of 424 patients, including 231 men, were included in the study. The average age of all patients was 34.9 ± 13.2 years. There was no statistically significant difference between the uncomplicated appendicitis, complicated appendicitis and control groups in terms of MPV, PC and the MPV/PC ratio. Leukocyte count had a strong discriminatory property based on the area under curve (AUC) 0.73, (p < 0.001). CRP levels, MPV, PC and the MPV/PC ratio had weak discriminatory power with AUC values <0.65. Using receiver operating characteristic (ROC) analysis, the sensitivity and specificity of MPV were 83.79% and 23.21%, respectively, and 66.48% and 48.21%, respectively, for the MPV/PC ratio.

CONCLUSIONS

In our study, MPV and the MPV/PC ratio were not useful in the diagnosis of acute appendicitis.

Long-Term Complications of Appendectomy: A Systematic Review

BACKGROUND AND AIMS

Appendectomy is a common surgical procedure, but no overview of the long-term consequences exists. Our aim was to systematically review the long-term complications of appendectomy for acute appendicitis.

MATERIALS AND METHODS

This systematic review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A protocol was registered on PROSPERO (CRD42017064662). The databases PubMed and EMBASE were searched for original reports on appendectomy with n ≥ 500 and follow-up >30 days. The surgical outcomes were ileus and incisional hernia; other outcomes were inflammatory bowel disease, cancer, fertility, and mortality.

RESULTS

We included 37 studies. The pooled estimate of the ileus prevalence was 1.0% over a follow-up period of 4.6 (range, 0.5-15) years. Regarding incisional hernia, we found a pooled estimate of 0.7% prevalence within a follow-up period of 6.5 (range, 1.9-10) years. Ulcerative colitis had a pooled estimate of 0.15% prevalence in the appendectomy group and 0.19% in controls. The opposite pattern was found regarding Crohn's disease with a pooled estimate of 0.20% prevalence in the appendectomy group and 0.12% in controls. No clear pattern was found regarding most of the examined cancers in appendectomy groups compared with background populations. Pregnancy rates increased after appendicitis compared with controls in most studies. Mortality was low after appendectomy.

CONCLUSION

Appendectomy had a low prevalence of long-term surgical complications. We did not find any significant other long-term complications, though the prevalence of Crohn's disease was higher and the prevalence of ulcerative colitis was lower after appendectomy than in controls. Appendectomy did not impair fertility.

Abdominal drainage to prevent intra-peritoneal abscess after open appendectomy for complicated appendicitis

BACKGROUND

Appendectomy, the surgical removal of the appendix, is performed primarily for acute appendicitis. Patients who undergo appendectomy for complicated appendicitis, defined as gangrenous or perforated appendicitis, are more likely to suffer from postoperative complications. The routine use of abdominal drainage to reduce postoperative complications after appendectomy for complicated appendicitis is controversial.This is an update of the review first published in 2015.

OBJECTIVES

To assess the safety and efficacy of abdominal drainage to prevent intra-peritoneal abscess after open appendectomy for complicated appendicitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 6), Ovid MEDLINE (1946 to 30 June 2017), Ovid Embase (1974 to 30 June 2017), Science Citation Index Expanded (1900 to 30 June 2017), World Health Organization International Clinical Trials Registry Platform (30 June 2017), ClinicalTrials.gov (30 June 2017) and Chinese Biomedical Literature Database (CBM) (1978 to 30 June 2017).

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that compared abdominal drainage and no drainage in people undergoing emergency open appendectomy for complicated appendicitis.

DATA COLLECTION AND ANALYSIS

Two review authors identified the trials for inclusion, collected the data, and assessed the risk of bias independently. We performed the meta-analyses using Review Manager 5. We calculated the risk ratio (RR) for dichotomous outcomes (or a Peto odds ratio for very rare outcomes), and the mean difference (MD) for continuous outcomes with 95% confidence intervals (CI). We used GRADE to rate the quality of evidence.

MAIN RESULTS

We included six RCTs (521 participants), comparing abdominal drainage and no drainage in patients undergoing emergency open appendectomy for complicated appendicitis. The studies were conducted in North America, Asia and Africa. The majority of the participants had perforated appendicitis with local or general peritonitis. All participants received antibiotic regimens after open appendectomy. None of the trials was at low risk of bias.There was insufficient evidence to determine the effects of abdominal drainage and no drainage on intra-peritoneal abscess at 14 days (RR 1.23, 95% CI 0.47 to 3.21; 5 RCTs; 453 participants; very low-quality evidence) or for wound infection at 14 days (RR 2.01, 95% CI 0.88 to 4.56; 5 RCTs; 478 participants; very low-quality evidence). The increased risk of 30-day overall complication rate (morbidity) in the drainage group was rated as very low-quality evidence (RR 6.67, 95% CI 2.13 to 20.87; 1 RCT; 90 participants). There were seven deaths in the drainage group (N = 183) compared to one in the no drainage group (N = 180), equating to an increase in the risk of 30-day mortality from 0.6% to 2.7% (Peto odds ratio (OR) 4.88, 95% CI 1.18 to 20.09; 4 RCTs; 363 participants; moderate-quality evidence). There is 'very low-quality' evidence that drainage increases hospital stay compared to the no drainage group by 2.17 days (95% CI 1.76 to 2.58; 3 RCTs; 298 participants).Other outlined outcomes, hospital costs, pain, and quality of life, were not reported in any of the included studies.

AUTHORS' CONCLUSIONS

The quality of the current evidence is very low. The effect of abdominal drainage on the prevention of intra-peritoneal abscess or wound infection after open appendectomy is uncertain for patients with complicated appendicitis. The increased rates for overall complication rate and hospital stay for the drainage group compared to no drainage group is also subject to great uncertainty. Thus, there is no evidence for any clinical improvement by using abdominal drainage in patients undergoing open appendectomy for complicated appendicitis. The increased risk of mortality with drainage comes from eight deaths observed in just under 400 people recruited to the studies. Larger studies are needed to determine the effects of drainage on morbidity and mortality outcomes more reliably.

Improving the value of ultrasound in children with suspected appendicitis: a prospective study integrating secondary sonographic signs

PURPOSE

The purpose of this study was to determine whether the awareness and inclusion of secondary sonographic signs of appendicitis, in combination with a structured evaluation as part of engagement and training for sonographers, improved appendix visualization rates and reduced equivocal findings in children with suspected acute appendicitis.

METHODS

This was a prospective study of 230 children at a tertiary children's hospital in Australia referred for an ultrasound examination of suspected appendicitis. The ultrasound findings, radiology reports, histology, clinical results, and follow-up were collated. Secondary signs were used as an additional assessment of the likelihood of disease where possible, even in the absence of an identified appendix.

RESULTS

The implementation of a structured evaluation as part of sonographer engagement and training resulted in a 28% improvement in appendix visualization (68.7%) compared with a prior retrospective study in a similar population (40.7%). The diagnostic accuracy was 91.7%, with likelihood ratios suggesting a meaningful influence of the pre-test probability of appendicitis in children studied (positive likelihood ratio, 11.22; negative likelihood ratio, 0.09.). Only 7.8% of the findings were equivocal. A binary 6-mm diameter cut-off did not account for equivocal cases, particularly lymphoid hyperplasia.

CONCLUSION

Engagement of sonographers performing pediatric appendiceal ultrasound through training in the scanning technique and awareness of secondary signs significantly improved the visualization rate and provided more meaningful findings to referrers.

Two versus five days of antibiotics after appendectomy for complex acute appendicitis (APPIC): study protocol for a randomized controlled trial

Background

Acute appendicitis is one of the most common indications for emergency surgery. In patients with a complex appendicitis, prolonged antibiotic prophylaxis is recommended after appendectomy. There is no consensus regarding the optimum duration of antibiotics. Guidelines propose 3 to 7 days of treatment, but shorter courses may be as effective in the prevention of infectious complications. At the same time, the global issue of increasing antimicrobial resistance urges for optimization of antibiotic strategies. The aim of this study is to determine whether a short course (48 h) of postoperative antibiotics is non-inferior to current standard practice of 5 days.

Methods

Patients of 8 years and older undergoing appendectomy for acute complex appendicitis – defined as a gangrenous and/or perforated appendicitis or appendicitis in presence of an abscess – are eligible for inclusion. Immunocompromised or pregnant patients are excluded, as well as patients with a contraindication to the study antibiotics. In total, 1066 patients will be randomly allocated in a 1:1 ratio to the experimental treatment arm (48 h of postoperative intravenously administered (IV) antibiotics) or the control arm (5 days of postoperative IV antibiotics). After discharge from the hospital, patients participate in a productivity-cost-questionnaire at 4 weeks and a standardized telephone follow-up at 90 days after appendectomy. The primary outcome is a composite endpoint of infectious complications, including intra-abdominal abscess (IAA) and surgical site infection (SSI), and mortality within 90 days after appendectomy. Secondary outcomes include IAA, SSI, restart of antibiotics, length of hospital stay (LOS), reoperation, percutaneous drainage, readmission rate, and cost-effectiveness. The non-inferiority margin for the difference in the primary endpoint rate is set at 7.5% (one-sided test at ɑ 0.025). Both per-protocol and intention-to-treat analyses will be performed.

Discussion

This trial will provide evidence on whether 48 h of postoperative antibiotics is non-inferior to a standard course of 5 days of antibiotics. If non-inferiority is established, longer intravenous administration following appendectomy for complex appendicitis can be abandoned, and guidelines need to be adjusted accordingly.

Trial registration

Dutch Trial Register, NTR6128. Registered on 20 December 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2629-0) contains supplementary material, which is available to authorized users.

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study

BACKGROUND

Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide.

METHODS

This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days.

RESULTS

4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45).

CONCLUSION

A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments.

TRIAL REGISTRATION

NCT02179112.

Prevalence of Parasitic Infections in Surgically Removed Appendices: Parasitological and Histopathological Studies

Intestinal parasites may cause symptoms similar to acute appendicitis. Moreover, the diagnosis of parasitic infections is only done by post-operative histopathological examination of the appendices. Therefore, our aims are to assess the prevalence of intestinal parasitic infections among patients who were be appendectomized at Tanta Hospitals, Egypt and to investigate the possible association between these parasitic infections and appendicitis. To achieve these objectives, we performed a cross-sectional study including 65 patients chosen randomly who had undergone appendectomy over a period of one year from Oct 2015 to Oct 2016. Demographic data were retrieved. Complete blood picture was done. Moreover, appendiceal faecolith were examined macroscopically then by direct smear examination, formol-ether concentration technique, modified Ziehl-Nelseen stain and rapid immunochromatographic test. Histopathological examination of resected appendices was done. We found that parasitic infections were detected in 24.6 % of examined cases. Most of parasitic infections were prevalent in patients belonging to the school age group. Different parasitic infections were detected in the faecolith specimens. Moreover, Enterobious vermicularis adult female and Schistosoma mansoni granuloma were detected in histopathological sections. Also, a spectrum of pathological changes in the appendices was found ranging from lymphoid hyperplasia to acute inflammation with peritonitis. In conclusion, intestinal parasites may cause clinical picture similar to that of acute appendicitis. Therefore, careful attention to clinical history, stool examination and high eosinophilia may aid diagnosis and avoid unnecessary appendectomy. Moreover, the presence of different parasitic stages in the narrow lumen of the appendix may have a role in the development of appendicitis and this needs further studies.