Diagnosis and treatment of acute appendicitis: WSES Updated guidelines

World Society of Emergency Surgery (WSES) has updated its 2015 evidence-based guidelines on diagnosis and treatment of acute appendicitis. The guidelines have been published in the World Journal of Emergency Surgery.

The 2020 WSES guidelines on AA aim to provide updated evidence-based statements and recommendations on each of the following topics: (1) diagnosis, (2) non-operative management for uncomplicated AA, (3) timing of appendectomy and in-hospital delay, (4) surgical treatment, (5) intra-operative grading of AA, (6), management of perforated AA with phlegmon or abscess, and (7) peri-operative antibiotic therapy.

Acute appendicitis (AA) is among the most common causes of acute abdominal pain. Diagnosis of AA is still challenging and some controversies on its management are still present among different settings and practice patterns worldwide

Key recommendations are-

We recommend adopting a tailored individualized diagnostic approach for stratifying the risk and disease probability and planning an appropriate stepwise diagnostic pathway in patients with suspected acute appendicitis, depending on age, sex, and clinical signs and symptoms of the patient.

We recommend the use of clinical scores to exclude acute appendicitis and identify intermediate-risk patients needing of imaging diagnostics.

We suggest not making the diagnosis of acute appendicitis in pregnant patients on symptoms and signs only. Laboratory tests and inflammatory serum parameters (e.g., CRP) should always be requested.

We suggest against the use of Alvarado score to positively confirm the clinical suspicion of acute appendicitis in adults.

We recommend the use of AIR score and AAS score as clinical predictors of acute appendicitis.

In pediatric patients with suspected acute appendicitis, we suggest against making a diagnosis based on clinical scores alone.

In evaluating children with suspected appendicitis, we recommend requesting routinely laboratory tests and serum inflammatory biomarkers.

In pediatric patients with suspected acute appendicitis, we suggest adopting both biomarker tests and scores in order to predict the severity of the inflammation and the need for an imaging investigation.

We recommend the routine use of a combination of clinical parameters and US to improve diagnostic sensitivity and specificity and reduce the need for CT scan in the diagnosis of acute appendicitis. The use of imaging diagnostics is recommended in patients with suspected appendicitis after an initial assessment and risk stratification using clinical scores [QoE: Moderate; Strength of recommendation: Strong; 1B].

We suggest proceeding with timely and systematic diagnostic imaging in patients with intermediate-risk of acute appendicitis .

We suggest that cross-sectional imaging (i.e., CT scan) for high-risk patients younger than 40 years old (AIR score 9–12, Alvarado score 9–10, and AAS ≥ 16) may be avoided before diagnostic +/− therapeutic laparoscopy.

We recommend POCUS as the most appropriate first-line diagnostic tool in both adults and children if an imaging investigation is indicated based on clinical assessment.

We recommend the use of contrast-enhanced low-dose CT scan over contrast-enhanced standard-dose CT scan in patients with suspected acute appendicitis and negative US findings.

We recommend cross-sectional imaging before surgery for patients with normal investigations but non-resolving right iliac fossa pain. After negative imaging, initial non-operative treatment is appropriate. However, in patients with progressive or persistent pain, explorative laparoscopy is recommended to establish/exclude the diagnosis of acute appendicitis or alternative diagnoses.

We suggest graded compression trans-abdominal ultrasound as the preferred initial imaging method for suspected acute appendicitis during pregnancy.

We suggest MRI in pregnant patients with suspected appendicitis, if this resource is available, after inconclusive US [QoE: Moderate; Strength of recommendation: Weak; 2B].

In pediatric patients with suspected appendicitis, we suggest the use of US as first-line imaging. In pediatric patients with inconclusive US, we suggest choosing the second-line imaging technique based on local availability and expertise, as there are currently no strong data to suggest a best diagnostic pathway due to a variety of options and dependence on local resources.

Since in pediatric patients with equivocal CT finding the prevalence of true acute appendicitis is not negligible, we suggest against the routine use of CT as first-line imaging in children with right iliac fossa pain .

We recommend discussing NOM with antibiotics as a safe alternative to surgery in selected patients with uncomplicated acute appendicitis and absence of appendicolith, advising of the possibility of failure and misdiagnosing complicated appendicitis.

We suggest against treating acute appendicitis non-operatively during pregnancy until further high-level evidence is available.

NOM for uncomplicated acute appendicitis in children is feasible, safe, and effective as initial treatment. However, the failure rate increases in the presence of appendicolith, and surgery is recommended in such cases.

We suggest discussing NOM with antibiotics as a safe and effective alternative to surgery in children with uncomplicated acute appendicitis in the absence of an appendicolith, advising of the possibility of failure and misdiagnosing complicated appendicitis.

In the case of NOM, we recommend initial intravenous antibiotics with a subsequent switch to oral antibiotics based on the patient's clinical conditions.

We recommend planning laparoscopic appendectomy for the next available operating list within 24 h in case of uncomplicated acute appendicitis, minimizing the delay wherever possible.

We recommend against delaying appendectomy for acute appendicitis needing surgery beyond 24 h from the admission.

We suggest against delaying appendectomy for pediatric patients with uncomplicated acute appendicitis needing surgery beyond 24 h from the admission. Early appendectomy within 8 h should be performed in case of complicated appendicitis.

We recommend laparoscopic appendectomy as the preferred approach over open appendectomy for both uncomplicated and complicated acute appendicitis, where laparoscopic equipment and expertise are available.

Recommendation 4.2 We recommend laparoscopic appendectomy should be preferred over open appendectomy in children where laparoscopic equipment and expertise are available.

We recommend conventional three-port laparoscopic appendectomy over single-incision laparoscopic appendectomy, as the conventional laparoscopic approach is associated with shorter operative times, less postoperative pain, and lower incidence of wound infection.

In pediatric patients with acute appendicitis and favorable anatomy, we suggest performing single-incision/transumbilical extracorporeal laparoscopic-assisted appendectomy or traditional three-port laparoscopic appendectomy based on local skills and expertise.

We suggest the adoption of outpatient laparoscopic appendectomy for uncomplicated appendicitis, provided that an ambulatory pathway with well-defined ERAS protocols and patient information/consent are locally established.

We suggest laparoscopic appendectomy in obese patients, older patients, and patients with high peri- and postoperative risk factors.

We suggest laparoscopic appendectomy should be preferred to open appendectomy in pregnant patients when surgery is indicated. Laparoscopy is technically safe and feasible during pregnancy where the expertise of laparoscopy is available.

We recommend performing suction alone in complicated appendicitis patients with intra-abdominal collections undergoing laparoscopic appendectomy.

We suggest the use of monopolar electrocoagulation and bipolar energy as they are the most cost-effective techniques, whereas other energy devices can be used depending on the intra-operative judgment of the surgeon and resources available

We recommend the use of endoloops/suture ligation or polymeric clips for stump closure for both adults and children in either uncomplicated or complicated appendicitis, whereas endostaplers may be used when dealing with complicated cases depending on the intra-operative judgment of the surgeon and resources available.

We recommend simple ligation over stump inversion either in open and laparoscopic appendectomy.

We recommend against the use of drains following appendectomy for complicated appendicitis in adult patients.

We suggest the prophylactic use of abdominal drainage after laparoscopic appendectomy for complicated appendicitis in children.

We recommend wound ring protectors in open appendectomy to decrease the risk of SSI.

We recommend primary skin closure with a unique absorbable intradermal suture for open appendectomy wounds.

We recommend routine histopathology after appendectomy.

We suggest the routine adoption of an intra-operative grading system for acute appendicitis (e.g., WSES 2015 grading score or AAST EGS grading score) based on clinical, imaging and operative findings.

We suggest appendix removal if the appendix appears "normal" during surgery and no other disease is found in symptomatic patients.

We suggest non-operative management with antibiotics and—if available—percutaneous drainage for complicated appendicitis with a periappendicular abscess, in settings where laparoscopic expertise is not available

We suggest the laparoscopic approach as treatment of choice for patients with complicated appendicitis with phlegmon or abscess where advanced laparoscopic expertise is available, with a low threshold for conversion.

We suggest both colonic screening with colonoscopy and interval full-dose contrast-enhanced CT scan for patients with appendicitis treated non-operatively if ≥ 40 years old.

We recommend a single preoperative dose of broad-spectrum antibiotics in patients with acute appendicitis undergoing an appendectomy. We recommend against postoperative antibiotics for patients with uncomplicated appendicitis.

We recommend against prolonging antibiotics longer than 3–5 days postoperatively in case of complicated appendicitis with adequate source control

We recommend early switch (after 48 h) to oral administration of postoperative antibiotics in children with complicated appendicitis, with an overall length of therapy shorter than seven days.

In pediatric patients operated for uncomplicated acute appendicitis, we suggest against using postoperative antibiotic therapy.

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Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines