Normal inflammatory markers and acute appendicitis: a national multicentre prospective cohort analysis.

PURPOSE: For the diagnosis of acute appendicitis, the combination of clinical and laboratory variables achieves high diagnostic accuracy. Nevertheless, appendicitis can present with normal laboratory tests of inflammation. The aim of this study was to investigate the incidence of normal inflammatory markers in patients operated for acute appendicitis. METHODS: This is an analysis of data from a prospective, multicentre SNAPSHOT cohort study of patients with suspected acute appendicitis. Only patients with histopathologically proven acute appendicitis were included. Adult patients with acute appendicitis and normal preoperative inflammatory markers were explored further in terms of abdominal complaints, preoperative imaging results and intraoperative assessment of the degree of inflammation and compared to those with elevated inflammatory markers. RESULTS: Between June and July 2014, 1303 adult patients with histopathologically proven acute appendicitis were included. In only 23 of 1303 patients (1.8%) with proven appendicitis, both preoperative white blood cell count and C-reactive protein levels were normal. Migration of pain was reported less frequently in patients with normal inflammatory markers compared to those with elevated inflammatory marker levels (17.4% versus 43.0%, p = 0.01). Characteristics like fever, duration of symptoms and localized peritonitis were comparable. Only 4 patients with normal inflammatory markers (0.3% overall) had complicated appendicitis at histopathological evaluation. CONCLUSION: Combined normal WBC and CRP levels are seen in about 2 per 100 patients with confirmed acute appendicitis and can, although rarely, be found in patients with complicated appendicitis.

Appendicular neoplasms and consequences in patients undergoing surgery for suspected acute appendicitis.

INTRODUCTION: In patients treated with an appendectomy for acute appendicitis, the specimen is generally sent for histological evaluation. In an era of increasing non-operative treatment for acute appendicitis, it is important to know the incidence, the diagnostic accuracy, and treatment consequences of appendicular neoplasms that are found in acute appendicitis. We hypothesize that pre- and intra-operative parameters might predict an appendicular neoplasm. METHODS: Data was used from our previous prospective observational cohort study. All patients undergoing surgery for suspected acute appendicitis were included. The primary outcome was the incidence of appendicular neoplasms in patients operated for acute appendicitis. Secondary outcomes were pre-operative diagnostics and imaging outcomes, intra-operative surgical judgment, and postoperative management and outcome. Possible predictors of an appendicular neoplasm were identified and used in multivariable logistic regression. Patients with an appendicular neoplasm were followed for 3 years after initial appendectomy. RESULTS: A total of 1975 patients underwent surgery for suspected acute appendicitis and in 98.3% (1941/1975) the appendix was removed. In 1.5% (30/1941) of these patients, an appendicular neoplasm was found. Among the malignant neoplasms, the majority were grade 1 neuroendocrine tumors (NET) in 65% (13/20). On pre-operative imaging, there was no suspicion of malignancy. In three cases, there was an intra-operative suspicion of malignancy. Multivariable analysis showed only age as an independent predictor for appendicular neoplasms. No recurrent or new malignancy was found during follow-up. DISCUSSION: The incidence of appendicular neoplasm in patients undergoing an acute appendectomy is very low and clinical risk factors could not be identified.

Predictors for interval appendectomy in non-operatively treated complicated appendicitis.

PURPOSE: To determine the incidence rate and identify predictive factors for interval appendectomy after non-operatively treated complicated appendicitis. METHODS: Single-center retrospective cohort study conducted between January 2008 and June 2017. Adult patients with acute appendicitis were identified. Patients with complicated appendicitis initially treated non-operatively were included. Outcomes included abscess rate on imaging, results of additional imaging during follow-up, incidence rate of and surgical indications for interval appendectomy, and outcomes of histological reports. RESULTS: Of all adult patients with acute appendicitis (n = 1839), 9% (170/1839) was initially treated non-operatively. Median age of these patients was 55 years (IQR 42-65) and 48.8% (83/170) were men. In 36.4% (62/170) of the patients, an appendicular abscess was diagnosed. 62.4% (106/170) did not require subsequent surgery (no interval appendectomy group) and in 37.6% (64/170), an interval appendectomy was performed (interval appendectomy group). Median follow-up was 80 weeks (17-192) and 113 weeks (34-246), respectively. Most frequent reason to perform subsequent surgery was recurrent appendicitis (45% (29/64)). Increasing age was significantly associated with a lower risk of undergoing interval appendectomy (OR 0.7; CI 0.6-0.89); p = 0.002). In the interval appendectomy group, appendicular neoplasm was found in 11% (7/64) of the patients, in contrast to 1.5% (25/1669) of the patients that had acute surgery (p < 0.001). CONCLUSIONS: One out of three patients non-operatively treated for complicated appendicitis required an interval appendectomy. The incidence of appendicular neoplasms was high in these patients compared with those that had acute surgery. Therefore, additional radiological imaging following non-operatively treated complicated appendicitis is recommended.

Interobserver variability in the classification of appendicitis during laparoscopy.

BACKGROUND: The intraoperative classification of appendicitis dictates the patient's postoperative management. Prolonged antibiotic prophylaxis is recommended for complex appendicitis (gangrenous, perforated, abscess), whereas preoperative prophylaxis suffices for simple appendicitis. Distinguishing these two conditions can be challenging. The aim of this study was to assess interobserver variability in the classification of appendicitis during laparoscopy. METHODS: Short video recordings taken during laparoscopy for suspected appendicitis were shown to surgeons and surgical residents. They were asked to: classify the appendix as indicative of no, simple or complex appendicitis; categorize the appendix as normal, phlegmonous, gangrenous, perforated and/or abscess; and decide whether they would prescribe postoperative antibiotics. Inter-rater reliability was evaluated using Fleiss' κ score and the S* statistic. RESULTS: Some 80 assessors participated in the study. Video recordings of 20 patients were used. Interobserver agreement was minimal for both the classification of appendicitis (κ score 0·398, 95 per cent c.i. 0·385 to 0·410) and the decision to prescribe postoperative antibiotic treatment (κ score 0·378, 0·362 to 0·393). Agreement was slightly higher when published criteria were applied (κ score 0·552, 0·537 to 0·568). CONCLUSION: There is considerable variability in the intraoperative classification of appendicitis and the decision to prescribe postoperative antibiotic treatment.

Imaging in pediatric appendicitis is key to a low normal appendix percentage: a national audit on the outcome of appendectomy for appendicitis in children.

PURPOSE: A laparoscopic approach for emergency appendectomy is increasingly used, in pediatric patients as well. The objective of this study is to audit the current state of diagnostic work-up, surgical techniques and its outcome in children with acute appendicitis. METHODS: A prospective consecutive observational cohort study was carried out in a 2-month study period. All patients under 18 years that were operated for suspected acute appendicitis were included. Primary outcome was the infectious complication rate after open and laparoscopic approach; secondary outcomes were preoperative use of imaging and post-operative predictive value of imaging, normal appendix rate and children with a postoperative ileus. RESULTS: A total of 541 children were operated for suspected acute appendicitis in 62 Dutch hospitals. Preoperative imaging was used in 98.9% of children. The normal appendix rate was 3.1%. In 523 children an appendectomy was performed. Laparoscopy was used in 61% of the patients and conversion rate was 1.7%. Complicated appendicitis was diagnosed in 29.4% of children. Overall 30-day complication rate was 11.9% and similar after open and laparoscopic. No difference was found in superficial surgical site infections, nor in intra-abdominal abscesses between the open and laparoscopic approach. Complicated appendicitis is an independent risk factor for infectious complications. CONCLUSION: The laparoscopic approach is most frequently used, except for young children. Superficial surgical site infections are more frequent after open surgery only in patients with complicated appendicitis. The normal appendix rate is low, most likely because of routine preoperative imaging.

Prospective nationwide outcome audit of surgery for suspected acute appendicitis.

BACKGROUND: Studies comparing laparoscopic and open appendicectomy are difficult to interpret owing to several types of bias, and the results often seem of limited clinical importance. National audits can be valuable to provide insight into outcomes following appendicectomy at a population level. METHODS: A prospective, observational, resident-led, nationwide audit was carried out over a period of 2 months, including all consecutive adult patients who had surgery for suspected acute appendicitis. Complications after laparoscopic and open appendicectomy were compared by means of logistic regression analysis; subgroup analyses were performed for patients with complicated appendicitis. RESULTS: A total of 1975 patients were included from 62 participating Dutch hospitals. A normal appendix was seen in 3·3 per cent of patients. Appendicectomy was performed for acute appendicitis in 1378 patients, who were analysed. All but three patients underwent preoperative imaging. Laparoscopy was used in 79·5 per cent of patients; the conversion rate was 3·4 per cent. A histologically normal appendix was found in 2·2 per cent. Superficial surgical-site infection was less common in the laparoscopic group (odds ratio 0·25, 95 per cent c.i. 0·14 to 0·44; P < 0·001). The rate of intra-abdominal abscess formation was not significantly different following laparoscopic or open surgery (odds ratio 1·71, 0·80 to 3·63; P = 0·166). Similar findings were observed in patients with complicated appendicitis. CONCLUSION: Management of acute appendicitis in the Netherlands is preferably performed laparoscopically, characterized by a low conversion rate. Fewer superficial surgical-site infections occurred with laparoscopy, although the rate of abscess formation was no different from that following open surgery. A low normal appendix rate is the presumed effect of a mandatory preoperative imaging strategy.

Diagnosing acute appendicitis: surgery or imaging?

AIM: Investigation of suspected appendicitis varies widely across different countries, which creates variation in outcome for patients. Use of imaging drives much of this variation, with concerns over delay of imaging and radiation exposure of computed tomography being balanced against the risks of unnecessary surgery. METHOD: Two national, prospective snapshot audits (UK n = 3326 and Netherlands n = 1934) reported investigation, management and outcome of appendicectomy and can be compared to generate treatment recommendations. RESULTS: Preoperative imaging was conducted in 32.8% of UK patients in contrast to 99.5% of patients in the Netherlands. A large difference in the normal appendicectomy rate was observed (20.6% in the UK vs 3.2% in the Netherlands) and the connection between these two outcome differences cannot be neglected. CONCLUSION: This article discusses the role of imaging in the diagnostic work-up of patients who are suspected of acute appendicitis, comparing national snapshot studies as a model to do so.

Scoring system to distinguish uncomplicated from complicated acute appendicitis.

BACKGROUND: Non-operative management may be an alternative for uncomplicated appendicitis, but preoperative distinction between uncomplicated and complicated disease is challenging. This study aimed to develop a scoring system based on clinical and imaging features to distinguish uncomplicated from complicated appendicitis. METHODS: Patients with suspected acute appendicitis based on clinical evaluation and imaging were selected from two prospective multicentre diagnostic accuracy studies (OPTIMA and OPTIMAP). Features associated with complicated appendicitis were included in multivariable logistic regression analyses. Separate models were developed for CT and ultrasound imaging, internally validated and transformed into scoring systems. RESULTS: A total of 395 patients with suspected acute appendicitis based on clinical evaluation and imaging were identified, of whom 110 (27·8 per cent) had complicated appendicitis, 239 (60·5 per cent) had uncomplicated appendicitis and 46 (11·6 per cent) had an alternative disease. CT was positive for appendicitis in 284 patients, and ultrasound imaging in 312. Based on clinical and CT features, a model was created including age, body temperature, duration of symptoms, white blood cell count, C-reactive protein level, and presence of extraluminal free air, periappendiceal fluid and appendicolith. A scoring system was constructed, with a maximum possible score of 22 points. Of the 284 patients, 150 had a score of 6 points or less, of whom eight (5·3 per cent) had complicated appendicitis, giving a negative predictive value (NPV) of 94·7 per cent. The model based on ultrasound imaging included the same predictors except for extraluminal free air. The ultrasound score (maximum 19 points) was calculated for 312 patients; 105 had a score of 5 or less, of whom three (2·9 per cent) had complicated appendicitis, giving a NPV of 97·1 per cent. CONCLUSION: With use of novel scoring systems combining clinical and imaging features, 95 per cent of the patients deemed to have uncomplicated appendicitis were correctly identified as such. The score can aid in selection for non-operative management in clinical trials.

Duration of antibiotic treatment after appendicectomy for acute complicated appendicitis.

BACKGROUND: Antibiotic treatment after appendicectomy for complicated appendicitis aims to reduce postoperative infections. However, available data on the duration of treatment are limited. This study compared the difference in infectious complications between two protocols, involving either 3 or 5 days of postoperative antibiotic treatment. METHODS: This was an observational cohort study of all adult patients who had an appendicectomy between January 2004 and December 2010 at either one of two hospitals in the same region. At location A, the protocol included 3 days of postoperative antibiotic treatment, whereas at location B it specified 5 days. The primary outcome was the development of postoperative infections as either superficial wound infection or deep intra-abdominal infections. RESULTS: A total of 1143 patients with acute appendicitis underwent appendicectomy, of whom 267 (23.4 per cent) had complicated appendicitis. The duration of postoperative antibiotic treatment was 3 days in 135 patients (50.6 per cent) and at least 5 days in 123 (46.1 per cent). No difference was found between antibiotic treatment for 3 or 5 days in terms of developing an intra-abdominal abscess (odds ratio (OR) 1.77, 95 per cent confidence interval 0.68 to 4.58; P = 0.242) or a wound infection (OR 2.74, 0.54 to 13.80; P = 0.223). In patients with complicated appendicitis, the laparoscopic approach was identified as a risk factor for developing an intra-abdominal abscess in univariable analysis (OR 2.46, 1.00 to 6.04; P = 0.049), but was not confirmed as an independent risk factor for this complication in multivariable analysis (OR 2.32, 0.75 to 7.14; P = 0.144). CONCLUSION: After appendicectomy for complicated appendicitis, 3 days of antibiotic treatment is equally effective as 5 days in reducing postoperative infections.

In-hospital Delay of Appendectomy in Acute, Complicated Appendicitis.

BACKGROUND: Present theory is that uncomplicated and complicated appendicitis are different entities. Recent studies suggest it is safe to delay surgery in patients with uncomplicated appendicitis. We hypothesize that patients with complicated appendicitis are at higher risk for postoperative complications when surgery is delayed. METHODS: Data was used from the multicenter, prospective SNAPSHOT appendicitis study of 1975 patients undergoing surgery for suspected appendicitis. Adult patients (≥ 18 years) who underwent appendectomy for appendicitis were included in this study. The primary outcome was the difference in postoperative complications between patients with complicated appendicitis who were operated within and after 8 h after hospital presentation. Secondary outcomes were the incidence of both uncomplicated and complicated appendicitis in relationship to delay of appendectomy. Follow-up was 30 days. A multivariable analysis was performed. RESULTS: Of 1341 adult patients with appendicitis, 34.3% had complicated appendicitis. In patients with complicated appendicitis, 22.8% developed a postoperative complication compared to 8.2% for uncomplicated appendicitis (P < 0.001). Delay in surgery (> 8 h) increased the complication rate in patients with complicated appendicitis (28.1%) compared to surgery within 8 h (18.3%; P = 0.01). Multivariate analysis showed a delay in surgery as an independent predictor for a postoperative complication in patients with complicated appendicitis (OR 1.71; 95%CI 1.01-2.68, P = 0.02). CONCLUSION: In-hospital delay of surgery (> 8 h) in patients with complicated appendicitis is associated with a higher risk of a postoperative complication. It is important that we recognize and treat these patients early.

Discriminating complicated from uncomplicated appendicitis by ultrasound imaging, computed tomography or magnetic resonance imaging: systematic review and meta-analysis of diagnostic accuracy.

BACKGROUND: Discriminating complicated from uncomplicated appendicitis is crucial. Patients with suspected complicated appendicitis are best treated by emergency surgery, whereas those with uncomplicated appendicitis may be treated with antibiotics alone. This study aimed to obtain summary estimates of the accuracy of ultrasound imaging, CT and MRI in discriminating complicated from uncomplicated appendicitis. METHODS: A systematic literature review was conducted by an electronic search in PubMed, Embase and the Cochrane Library for studies describing the diagnostic accuracy of complicated versus uncomplicated appendicitis. Studies were included if the population comprised adults, and surgery or pathology was used as a reference standard. Risk of bias and applicability were assessed with QUADAS-2. Bivariable logitnormal random-effect models were used to estimate mean sensitivity and specificity. RESULTS: Two studies reporting on ultrasound imaging, 11 studies on CT, one on MRI, and one on ultrasonography with conditional CT were included. Summary estimates for sensitivity and specificity in detecting complicated appendicitis could be calculated only for CT, because of lack of data for the other imaging modalities. For CT, mean sensitivity was 78 (95 per cent c.i. 64 to 88) per cent, and mean specificity was 91 (85 to 99) per cent. At a median prevalence of 25 per cent, the positive predictive value of CT for complicated appendicitis would be 74 per cent and its negative predictive value 93 per cent. CONCLUSION: Ultrasound imaging, CT and MRI have limitations in discriminating between complicated and uncomplicated appendicitis. Although CT has far from perfect sensitivity, its negative predictive value for complicated appendicitis is high.

[Revised guideline for acute appendicitis. Amendments to diagnostics and treatment]. / Herziene richtlijn over acute appendicitis.

Recently, the revised guideline 'Guideline for diagnostics and treatment of acute appendicitis' was published by the Dutch Surgical Society. A patient with limited clinical symptoms and low suspicion of appendicitis can be assessed again at a later time, during which ultrasound diagnostics can be repeated. Following an inconclusive ultrasound scan in children who possibly have appendicitis, it is no longer recommended to perform diagnostic laparoscopy; rather, MRI diagnostics are indicated. In young adults with possible appendicitis, in whom a diagnosis cannot be established using ultrasound, the advice is to use MRI diagnostics instead of CT imaging; this particularly applies to women of child-bearing age. For patients with appendicitis an appendectomy remains the recommended treatment, although one can consider treating adults with suspected simple appendicitis with antibiotics alone. It is important that this decision is made in consultation with the patient. Laparoscopic appendectomy reduces the number of wound infections and admission length, and is therefore usually preferred over open method appendectomy. If a patient with appendicitis is 24-28 weeks pregnant,consultation with a specialist centre is indicated regarding the obstetric management and possibly referral.

[Acute appendicitis: treatment in accordance with new guideline]. / Acute appendicitis.

In this clinical lesson we present two patient cases. A 66-year-old female patient with a clinical, biochemical and radiological suspicion of complex appendicitis. The patient undergoes an appendectomy and post-operative recovery is beset with complications. The other case involves a 24-year-old male patient with suspected simple appendicitis. He is successfully treated with antibiotics and without surgery. By using these patients as examples, we discuss the revised clinical guideline for diagnosing and treating acute appendicitis. Besides that, we also discuss the differentiation between simple and complex appendicitis and how this can influence the treatment plan.

[A man with abdominal pain, diarrhoea and rectal bleeding]. / Een man met buikpijn, diarree en rectaal bloedverlies.

A 49-year-old man came to the emergency room with abdominal pain, vomiting, diarrhoea and rectal bleeding. Both colonoscopy and CT of the abdomen showed cecocolic intussusception caused by an appendiceal mucocele. An ileocecal resection was performed via a laparoscopic approach and microscopy of the tissue showed a low-grade mucinous neoplasm.