Early versus delayed (interval) appendicectomy for the management of appendicular abscess and phlegmon: a systematic review and meta-analysis

Early versus delayed appendicectomy for appendiceal phlegmon or abscess

BACKGROUND

This is an update of a Cochrane review first published in 2017. Acute appendicitis (inflammation of the appendix) can be simple or complicated. Appendiceal phlegmon and appendiceal abscess are examples of complicated appendicitis. Appendiceal phlegmon is a diffuse inflammation in the bottom right of the appendix, while appendiceal abscess is a discrete inflamed mass in the abdomen that contains pus. Appendiceal phlegmon and abscess account for 2% to 10% of acute appendicitis. People with appendiceal phlegmon or abscess usually need an appendicectomy to relieve their symptoms (e.g. abdominal pain, loss of appetite, nausea, and vomiting) and avoid complications (e.g. peritonitis (infection of abdominal lining)). Surgery for people with appendiceal phlegmon or abscess may be early (immediately after hospital admission or within a few days of admission), or delayed (several weeks later in a subsequent hospital admission). The optimal timing of appendicectomy for appendiceal phlegmon or abscess is debated.

OBJECTIVES

To assess the effects of early appendicectomy compared to delayed appendicectomy on overall morbidity and mortality in people with appendiceal phlegmon or abscess.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, two other databases, and five trials registers on 11 June 2023, together with reference checking to identify additional studies.

SELECTION CRITERIA

We included all individual and cluster-randomised controlled trials (RCTs), irrespective of language, publication status, or age of participants, comparing early versus delayed appendicectomy in people with appendiceal phlegmon or abscess.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included eight RCTs that randomised 828 participants to early or delayed appendicectomy for appendiceal phlegmon (7 trials) or appendiceal abscess (1 trial). The studies were conducted in the USA, India, Nepal, and Pakistan. All RCTs were at high risk of bias because of lack of blinding and lack of published protocols. They were also unclear about methods of randomisation and length of follow-up. 1. Early versus delayed open or laparoscopic appendicectomy for appendiceal phlegmon We included seven trials involving 788 paediatric and adult participants with appendiceal phlegmon: 394 of the participants were randomised to the early appendicectomy group (open or laparoscopic appendicectomy as soon as the appendiceal mass resolved within the same admission), and 394 were randomised to the delayed appendicectomy group (initial conservative treatment followed by delayed open or laparoscopic appendicectomy several weeks later). There was no mortality in either group. The evidence is very uncertain about the effect of early appendicectomy on overall morbidity (risk ratio (RR) 0.74, 95% confidence interval (CI) 0.19 to 2.86; 3 trials, 146 participants; very low-certainty evidence), the proportion of participants who developed wound infections (RR 0.99, 95% CI 0.48 to 2.02; 7 trials, 788 participants), and the proportion of participants who developed faecal fistulas (RR 1.75, 95% CI 0.36 to 8.49; 5 trials, 388 participants). Early appendicectomy may reduce the abdominal abscess rate (RR 0.26, 95% CI 0.08 to 0.80; 4 trials, 626 participants; very low-certainty evidence), reduce the total length of hospital stay by about two days (mean difference (MD) -2.02 days, 95% CI -3.13 to -0.91; 5 trials, 680 participants), and increase the time away from normal activities by about five days (MD 5.00 days; 95% CI 1.52 to 8.48; 1 trial, 40 participants), but the evidence is very uncertain. 2. Early versus delayed laparoscopic appendicectomy for appendiceal abscess We included one trial involving 40 paediatric participants with appendiceal abscess: 20 were randomised to the early appendicectomy group (emergent laparoscopic appendicectomy), and 20 were randomised to the delayed appendicectomy group (initial conservative treatment followed by delayed laparoscopic appendicectomy 10 weeks later). There was no mortality in either group. The trial did not report on overall morbidity, various complications, or time away from normal activities. The evidence is very uncertain about the effect of early appendicectomy on the total length of hospital stay (MD -0.20 days, 95% CI -3.54 to 3.14; very low-certainty evidence).

AUTHORS' CONCLUSIONS

For the comparison of early versus delayed open or laparoscopic appendicectomy for paediatric and adult participants with appendiceal phlegmon, very low-certainty evidence suggests that early appendicectomy may reduce the abdominal abscess rate. The evidence is very uncertain whether early appendicectomy prevents overall morbidity or other complications. Early appendicectomy may reduce the total length of hospital stay and increase the time away from normal activities, but the evidence is very uncertain. For the comparison of early versus delayed laparoscopic appendicectomy for paediatric participants with appendiceal abscess, data are sparse, and we cannot rule out significant benefits or harms of early versus delayed appendicectomy. Further trials on this topic are urgently needed and should specify a set of criteria for use of antibiotics, percutaneous drainage of the appendiceal abscess prior to surgery, and resolution of the appendiceal phlegmon or abscess. Future trials should include outcomes such as time away from normal activities and length of hospital stay.

Problematic meta-analyses: Bayesian and frequentist perspectives on combining randomized controlled trials and non-randomized studies

PURPOSE

In the literature, the propriety of the meta-analytic treatment-effect produced by combining randomized controlled trials (RCT) and non-randomized studies (NRS) is questioned, given the inherent confounding in NRS that may bias the meta-analysis. The current study compared an implicitly principled pooled Bayesian meta-analytic treatment-effect with that of frequentist pooling of RCT and NRS to determine how well each approach handled the NRS bias.

MATERIALS & METHODS

Binary outcome Critical-Care meta-analyses, reflecting the importance of such outcomes in Critical-Care practice, combining RCT and NRS were identified electronically. Bayesian pooled treatment-effect and 95% credible-intervals (BCrI), posterior model probabilities indicating model plausibility and Bayes-factors (BF) were estimated using an informative heavy-tailed heterogeneity prior (half-Cauchy). Preference for pooling of RCT and NRS was indicated for Bayes-factors > 3 or < 0.333 for the converse. All pooled frequentist treatment-effects and 95% confidence intervals (FCI) were re-estimated using the popular DerSimonian-Laird (DSL) random effects model.

RESULTS

Fifty meta-analyses were identified (2009-2021), reporting pooled estimates in 44; 29 were pharmaceutical-therapeutic and 21 were non-pharmaceutical therapeutic. Re-computed pooled DSL FCI excluded the null (OR or RR = 1) in 86% (43/50). In 18 meta-analyses there was an agreement between FCI and BCrI in excluding the null. In 23 meta-analyses where FCI excluded the null, BCrI embraced the null. BF supported a pooled model in 27 meta-analyses and separate models in 4. The highest density of the posterior model probabilities for 0.333 < Bayes factor < 1 was 0.8.

CONCLUSIONS

In the current meta-analytic cohort, an integrated and multifaceted Bayesian approach gave support to including NRS in a pooled-estimate model. Conversely, caution should attend the reporting of naïve frequentist pooled, RCT and NRS, meta-analytic treatment effects.

Diverticulitis with coloenteric fistula mimicking gangrenous appendicitis with perityphlitic abscess. An uncommon presentation of a common disease - A case report

INTRODUCTION

Diverticulitis is a common gastrointestinal disease usually presenting with a typical clinical picture depending on the stage of the disease. In complicated cases, the clinical presentation may be untypical, thus delaying diagnosis and treatment.

PRESENTATION OF CASE

We present a case of a young patient who was initially treated for obscure intraabdominal abscesses presumably due to gangrenous appendicitis; however, intraoperative exploration revealed a normal appendix and a coloenteric fistula resulting from an unknown and untreated perforated diverticulitis.

DISCUSSION

A patient with a perityphlitic abscess was initially managed with primary non-operative management (NOM) in accordance with the current Jerusalem guidelines, but surgery was eventually necessary due to failure of NOM. Intraoperative findings revealed a sigmoido-ileal fistula, a rare but potentially detectable complication of diverticulitis through colonoscopy. This case highlights the challenges in diagnosing and treating common surgical diseases with uncommon clinical presentations, emphasizing the importance of a detailed patient history and not relying solely on imaging studies.

CONCLUSION

Intraabdominal abscesses require prompt treatment with non-operative management, while intestinal fistulae associated with diverticulitis are a rare consequence of chronic inflammation, often asymptomatic and often detected incidentally during surgery. In most cases simple fistulous tract resection is usually sufficient as first line therapy.

Usefulness of Preoperative Predictors of Pathological Complicated Appendicitis

INTRODUCTION

Complicated appendicitis (CA) is often indicated for emergency surgery; however, preoperative predictors of pathological CA (pCA) remain unclear. Furthermore, characteristics of CA that can be treated conservatively have not yet been established.

METHODS

305 consecutive patients diagnosed with acute appendicitis were reviewed. The patients were divided into two groups: an emergency surgery and a conservative treatment group. The emergency surgery group was pathologically classified as having uncomplicated appendicitis (pUA) and pCA, and the preoperative predictors of pCA were retrospectively assessed. Based on the preoperative pCA predictors, a predictive nomogram whether conservative treatment would be successful or not was created. The predictors were applied to the conservative treatment group, and the outcomes were investigated.

RESULTS

In the multiple logistic regression analysis of the factors contributing to pCA, C-reactive protein ≥3.5 mg/dL, ascites, appendiceal wall defect, and periappendiceal fluid collection were independent risk factors. Over 90% of cases without any of the above four preoperative pCA predictors were pUA. The accuracy of the nomogram was 0.938.

CONCLUSION

Our preoperative predictors and nomogram are useful to aid in distinguishing pCA and pUA and to predict whether or not conservative treatment will be successful. Some CA can be treated with conservative treatment.

Subacute Appendicular Abscess Masquerading as Neoplasia Causing Large Bowel Obstruction

Acute appendicitis is the most common reason for emergency abdominal surgery worldwide. Nonacute appendicitis variants include recurrent, subacute, and chronic appendicitis. Although these are not considered surgical emergencies, they are frequently overlooked, resulting in complications such as perforation or abscess formation. The presentation of nonacute forms is rare in the modern era because of sophisticated diagnostic modalities and treatment measures. We discuss a rare case of subacute appendicular abscess simulating a neoplasm with large bowel obstruction.

Diagnosis and Management of Acute Appendicitis in Adults: A Review

IMPORTANCE

Acute appendicitis is the most common abdominal surgical emergency in the world, with an annual incidence of 96.5 to 100 cases per 100 000 adults.

OBSERVATIONS

The clinical diagnosis of acute appendicitis is based on history and physical, laboratory evaluation, and imaging. Classic symptoms of appendicitis include vague periumbilical pain, anorexia/nausea/intermittent vomiting, migration of pain to the right lower quadrant, and low-grade fever. The diagnosis of acute appendicitis is made in approximately 90% of patients presenting with these symptoms. Laparoscopic appendectomy remains the most common treatment. However, increasing evidence suggests that broad-spectrum antibiotics, such as piperacillin-tazobactam monotherapy or combination therapy with either cephalosporins or fluroquinolones with metronidazole, successfully treats uncomplicated acute appendicitis in approximately 70% of patients. Specific imaging findings on computed tomography (CT), such as appendiceal dilatation (appendiceal diameter ≥7 mm), or presence of appendicoliths, defined as the conglomeration of feces in the appendiceal lumen, identify patients for whom an antibiotics-first management strategy is more likely to fail. CT findings of appendicolith, mass effect, and a dilated appendix greater than 13 mm are associated with higher risk of treatment failure (≈40%) of an antibiotics-first approach. Therefore, surgical management should be recommended in patients with CT findings of appendicolith, mass effect, or a dilated appendix who are fit for surgery, defined as having relatively low risk of adverse outcomes or postoperative mortality and morbidity. In patients without high-risk CT findings, either appendectomy or antibiotics can be considered as first-line therapy. In unfit patients without these high-risk CT findings, the antibiotics-first approach is recommended, and surgery may be considered if antibiotic treatment fails. In unfit patients with high-risk CT findings, perioperative risk assessment as well as patient preferences should be considered.

CONCLUSIONS AND RELEVANCE

Acute appendicitis affects 96.5 to 100 people per 100 000 adults per year worldwide. Appendectomy remains first-line therapy for acute appendicitis, but treatment with antibiotics rather than surgery is appropriate in selected patients with uncomplicated appendicitis.