Disconnect between incidence of nonperforated and perforated appendicitis: implications for pathophysiology and management

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.

Can abdominal surgical emergencies be treated in an ambulatory setting?

INTRODUCTION

The performance of emergency abdominal surgery in an outpatient setting is increasingly the order of the day in France. This review evaluates the feasibility and reliability of ambulatory surgical treatment of the most common abdominal emergencies: appendectomy for acute appendicitis and cholecystectomy for acute complications of gallstone disease (acute cholecystitis and gallstone pancreatitis).

METHODS

This study evaluates surgical procedures performed on an ambulatory basis according to the international definition (admission in the morning, discharge in the evening with a hospital stay of less than 12 hours). Just as for elective surgery, eligibility of patients for an ambulatory approach depends on the capacities of the surgical and anesthesia team: to manage the risks, particularly the risk of deferring surgery until the morning); to prevent or treat post-operative symptoms like pain, nausea, vomiting, re-ambulation in order to permit rapid post-operative discharge.

RESULTS

Recent studies have shown that appendectomy for non-complicated acute appendicitis can be deferred for up to 12 hours without any increase in danger. Many other studies have shown that early discharge after appendectomy for acute non-complicated appendicitis is feasible and safe. Nonetheless, there is only one published series of truly ambulatory appendectomies. The results were excellent. Patients who presented in the afternoon were brought back for operation the following morning. The appropriate timing for performance of cholecystectomy in patients with acute calculous cholecystitis or gallstone pancreatitis has not been well defined, but is always somewhat delayed relative to the onset of symptoms. To minimize operative complications, cholecystectomy for acute calculous cholecystitis should probably be performed between 24 and 72 hours after diagnosis. Cholecystectomy for gallstone pancreatitis should probably not be delayed longer than a week; the need to keep the patient hospitalized during the interval has not been demonstrated. Early discharge after cholecystectomy was usually possible, even in series where acute cholecystitis was diagnosed intra-operatively. Cholecystectomy for acute cholecystitis and gallstone pancreatitis seems to be feasible but no reports specifically support this approach.

CONCLUSIONS

Emergency abdominal surgery seems to be feasible on an ambulatory setting for non-complicated acute appendicitis, acute calculous cholecystitis and gallstone pancreatitis. Only a single French series on ambulatory appendectomy for acute appendicitis has been reported.

Clinical Health Service Research on the Surgical Therapy of Acute Appendicitis: Comparison of Outcomes Based on 3 German Multicenter Quality Assurance Studies Over 21 Years

OBJECTIVE

The treatment of acute appendicitis has seen changes in diagnosis and therapy in Germany. The objective of this analysis was to assess changes in therapy and outcome after open appendectomy (OA) and laparoscopic appendectomy (LA) over the last 21 years.

BACKGROUND

The analysis was based on 3 prospective multicenter quality assurance studies conducted by the Institute for Quality Control in Operative Medicine of the University of Magdeburg.

METHODS

All inpatients with a diagnosis of appendicitis in these studies (1988/1989, 1996/1997, 2008/2009) were included. Multiple linear and logistic regression analyses were performed. Statistical significance was set at P < 0.05.

RESULTS

Data from 17,732 treatments of patients diagnosed with appendicitis were collected. The average age of patients increased between the 3 studies from 25.7 to 34.6 years (P < 0.001). The preoperative selection of LA or OA was based on American Society of Anesthesiologists' classification (P < 0.001). Between 1996/1997 and 2008/2009, the share of LA climbed from 33.1% to 85.8% (P < 0.001). In the study from 2008 to 2009, LA showed a significant advantage over the conventional technique in wound healing disturbances (P < 0.001) and the clinical duration of stay (P < 0.001). At no stage of appendix inflammation did LA significantly increase intra-abdominal abscesses. The use of a stapler is currently the most common method of appendiceal stump closure (83.6%).

CONCLUSIONS

Changes in patient data reflected demographic changes. Preoperative selection leads to 2 clearly defined groups. LA is the most dominant method of current operative therapy. The negative selection in OA group has influenced the worse outcome of that group.

Acute appendicitis: modern understanding of pathogenesis, diagnosis, and management

Acute appendicitis is one of the most common abdominal emergencies worldwide. The cause remains poorly understood, with few advances in the past few decades. To obtain a confident preoperative diagnosis is still a challenge, since the possibility of appendicitis must be entertained in any patient presenting with an acute abdomen. Although biomarkers and imaging are valuable adjuncts to history and examination, their limitations mean that clinical assessment is still the mainstay of diagnosis. A clinical classification is used to stratify management based on simple (non-perforated) and complex (gangrenous or perforated) inflammation, although many patients remain with an equivocal diagnosis, which is one of the most challenging dilemmas. An observed divide in disease course suggests that some cases of simple appendicitis might be self-limiting or respond to antibiotics alone, whereas another type often seems to perforate before the patient reaches hospital. Although the mortality rate is low, postoperative complications are common in complex disease. We discuss existing knowledge in pathogenesis, modern diagnosis, and evolving strategies in management that are leading to stratified care for patients.

A scoring system to predict the severity of appendicitis in children

BACKGROUND

It appears that two forms of appendicitis exist. Preoperative distinction between the two is essential to optimize treatment outcome. This study aimed to develop a scoring system to accurately determine the severity of appendicitis in children.

MATERIALS AND METHODS

Historical cohort study of pediatric patients (aged 0-17 y old) with appendicitis treated between January 2010 and December 2012. Division into simple, complex appendicitis, or another condition based on preset criteria. Multiple logistic regression analysis was used to build the prediction model with subsequent validation.

RESULTS

There were 64 patients with simple and 66 with complex appendicitis. Five variables explained 64% of the variation. Independent validation of the derived prediction model in a second cohort (55 simple and 10 complex appendicitis patients) demonstrated 90% sensitivity (54-99), 91% specificity (79-97), a positive predictive value of 64% (36-86), and an negative predictive value of 98% (88-100). The likelihood ratio+ was 10 (4.19-23.42), and likelihood ratio- was 0.11 (0.02-0.71). Diagnostic accuracy was 91% (84-98).

CONCLUSIONS

Our scoring system consisting of five variables can be used to exclude complex appendicitis in clinical practice if the score is <4.

Can new inflammatory markers improve the diagnosis of acute appendicitis?

BACKGROUND

The diagnosis of appendicitis is difficult and resource consuming. New inflammatory markers have been proposed for the diagnosis of appendicitis, but their utility in combination with traditional diagnostic variables has not been tested. Our objective is to explore the potential of new inflammatory markers for improving the diagnosis of appendicitis.

METHODS

The diagnostic properties of the six most promising out of 21 new inflammatory markers (interleukin [IL]-6, chemokine ligand [CXCL]-8, chemokine C-C motif ligand [CCL]-2, serum amyloid A [SAA], matrix metalloproteinase [MMP]-9, and myeloperoxidase [MPO]) were compared with traditional diagnostic variables included in the Appendicitis Inflammatory Response (AIR) score (right iliac fossa pain, vomiting, rebound tenderness, guarding, white blood cell [WBC] count, proportion neutrophils, C-reactive protein and body temperature) in 432 patients with suspected appendicitis by uni- and multivariable regression models.

RESULTS

Of the new inflammatory variables, SAA, MPO, and MMP9 were the strongest discriminators for all appendicitis (receiver operating characteristics [ROC] 0.71) and SAA was the strongest discriminator for advanced appendicitis (ROC 0.80) compared with defence or rebound tenderness, which were the strongest traditional discriminators for all appendicitis (ROC 0.84) and the WBC count for advanced appendicitis (ROC 0.89). CCL2 was the strongest independent discriminator beside the AIR score variables in a multivariable model. The AIR score had an ROC area of 0.91 and could correctly classify 58.3 % of the patients, with an accuracy of 92.9 %. This was not improved by inclusion of the new inflammatory markers.

CONCLUSION

The conventional diagnostic variables for appendicitis, as combined in the AIR score, is an efficient screening instrument for classifying patients as low-, indeterminate-, or high-risk for appendicitis. The addition of the new inflammatory variables did not improve diagnostic performance further.

Surgical site infection after laparoscopic and open appendectomy: a multicenter large consecutive cohort study

BACKGROUND

Laparoscopic appendectomy (LA) has been rapidly applied worldwide recently. The issue of surgical site infection (SSI) after appendectomy needs to be re-investigated and analyzed along with this trend. This study aimed to identify risk factors of SSI after appendectomy in recent years.

METHODS

This retrospective study was conducted among patients with acute appendicitis who underwent either laparoscopic or open appendectomy (OA) at 7 general hospitals in China from 2010 to 2013. The incidence of SSI, classified as incisional SSI and organ/space SSI, was investigated. A multivariate logistic regression model was used to assess independent risk factors associated with overall, incisional, and organ/space SSI, respectively.

RESULTS

Among 16,263 consecutive patients, 3,422 (21.0 %) and 12,841 (79.0 %) patients underwent LA and OA, respectively. The incidences of overall, incisional, and organ/space SSI were 6.2, 3.7, and 3.0 %, respectively. The proportion of LAs among both procedures increased yearly from 5.3 to 46.5 %, while the incidences of overall and incisional SSI after appendectomy simultaneously decreased yearly from 9.6 to 4.5 % and from 6.7 to 2.2 %, respectively. In comparison with OA, LA was associated with lower incidences of overall and incisional SSI (4.5 vs 6.7 %, P < 0.001; and 1.9 vs 4.2 %, P < 0.001), but a similar incidence of organ/space SSI (3.0 vs 3.0 %, P = 0.995). After multivariate logistic regression analyses were performed, LA was found to be independently associated with a decrease in development of overall SSI [odds ratio (95 % confidence interval) OR (95 % CI), 1.24 (1.03-1.70); P = 0.04] or incisional SSI [OR (95 % CI), 1.32 (1.10-1.68); P = 0.01].

CONCLUSION

With the increasing application trends of laparoscopic procedure, the incidence of SSI after appendectomy declined accordingly. Compared with OA, LA was independently associated with a significantly lower incidence of incisional SSI, but a similar incidence of organ/space SSI.

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.

Initial antibiotic treatment for acute simple appendicitis in children is safe: Short-term results from a multicenter, prospective cohort study

BACKGROUND

Initial antibiotic treatment for acute appendicitis has been shown to be safe in adults; so far, not much is known about the safety and efficacy of this treatment in children. The aims of this study were to investigate the feasibility of a randomized controlled trial (RCT) evaluating initial antibiotic treatment for acute appendectomy in children with acute simple appendicitis and to evaluate the safety of this approach.

METHODS

In a multicenter, prospective cohort study patients aged 7-17 years with a radiologically confirmed simple appendicitis were eligible. Intravenous antibiotics (amoxicillin/clavulanic acid 250/25 mg/kg 4 times daily; maximum 6,000/600 mg/d and gentamicin 7 mg/kg once daily) were administered for 48-72 hours. Clinical reevaluation every 6 hours, daily blood samples, and ultrasound follow-up after 48 hours was performed. In case of improvement after 48 hours, oral antibiotics were given for a total of 7 days. At any time, in case of clinical deterioration or non-improvement after 72 hours, an appendectomy could be performed. Follow-up continued until 8 weeks after discharge. Adverse events were defined as major complications of antibiotic treatment, such as allergic reactions, perforated appendicitis, and recurrent appendicitis.

RESULTS

Of 44 eligible patients, 25 participated (inclusion rate, 57%; 95% CI, 42%-70%). Delayed appendectomy was performed in 2, and the other 23 were without symptoms at the 8 weeks follow-up. Minor complications occurred in three patients. None of the patients suffered from an adverse event or a recurrent appendicitis.

CONCLUSION

Our study shows that an RCT comparing initial antibiotic treatment strategy with urgent appendectomy is feasible in children; the intervention seems to be safe.

Epidemiology of appendicitis and appendectomy for the low-income population in Taiwan, 2003-2011

Background

Although numerous epidemiological studies on appendicitis have been conducted worldwide, only a few studies have paid attention to the effect of socioeconomic status on appendicitis, particularly studies focusing on the low-income population (LIP).

Methods

We analyzed the epidemiological features of appendicitis in Taiwan using data from the National Health Insurance Research Database from 2003 to 2011. All cases diagnosed as appendicitis were enrolled.

Results

Between 2003 and 2011, 2,916 patients from the LIP and 209,206 patients from the normal population (NP) were diagnosed with appendicitis. Our finding revealed that the ratios of comorbidities, complicated appendicitis, and readmissions in LIP patients were slightly higher than those of NP patients. LIP patients were more likely to live in suburban and rural areas, and hence a higher proportion of them were hospitalized in a district or regional hospital compared with NP patients. The crucially finding was that the overall incidence ratios of appendicitis, acute appendicitis, and perforated appendicitis in the LIP were substantially higher than those in the NP (36.25%, 35.33%, and 37.28%, respectively). The mean LOS in LIP patients was longer than that of NP patients. The overall case-fatality ratio of appendectomy in the LIP was higher when compared with the NP (0.41% versus 0.12%, p < 0.05). We also observed that appendicitis was occurred frequently in male patients, with a higher incidence for those aged 15–29 years in both the LIP and NP. The incidences of incidental appendectomy showed a decreasing trend in both the LIP and NP. Finally, a valuable discovery was that the total hospital cost was comparable between the laparoscopic appendectomy (LA) and open appendectomy (OA) (1,178 ± 13 USD versus 1,191 ± 19 USD, p < 0.05) in LIP patients because they saved more hospitalization costs than NP patients when the previous one chose the LA.

Conclusion

This study confirmed that a lower socioeconomic status has significantly negative impact on the occurrence and treatment of appendicitis and appendectomy. In terms of hospital costs and LOS, LIP patients benefit more from the LA approach than they do from the OA approach in the treatment of appendicitis.

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.

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 Library (Issue 1, 2014), MEDLINE (1950 to February 2014), EMBASE (1974 to February 2014), Science Citation Index Expanded (1900 to February 2014), and Chinese Biomedical Literature Database (CBM) (1978 to February 2014).

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that compared abdominal drainage and no drainage in patients 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).

MAIN RESULTS

We included five trials involving 453 patients with complicated appendicitis who were randomised to the drainage group (n = 228) and the no drainage group (n = 225) after emergency open appendectomies. All of the trials were at a high risk of bias. There were no significant differences between the two groups in the rates of intra-peritoneal abscess or wound infection. The hospital stay was longer in the drainage group than in the no drainage group (MD 2.04 days; 95% CI 1.46 to 2.62) (34.4% increase of an 'average' hospital stay).

AUTHORS' CONCLUSIONS

The quality of the current evidence is very low. It is not clear whether routine abdominal drainage has any effect on the prevention of intra-peritoneal abscess after open appendectomy for complicated appendicitis. Abdominal drainage after an emergency open appendectomy may be associated with delayed hospital discharge for patients with complicated appendicitis.

High admission C-reactive protein level and longer in-hospital delay to surgery are associated with increased risk of complicated appendicitis

PURPOSE

Debate on the effect of in-hospital delay on the risk of perforation in appendicitis persists, and the results from previous studies are controversial. The aims of this study were to present the effect of in-hospital delay on the risk of perforation in appendicitis and to assess the utility of C-reactive protein (CRP) measurement in detecting the patients with complicated appendicitis.

METHODS

Prospectively collected data of 389 adult patients who underwent surgery for acute appendicitis were analyzed in order to find the most accurate method for recognizing the pre-hospital perforations. The effect of in-hospital delay on the further risk of perforation in patients with not yet perforated acute appendicitis was then analyzed.

RESULTS

Out of 389 patients with appendicitis, 91 patients (23.4 %) had complicated appendicitis, 23 with abscess, and 68 with free perforation. Admission CRP level of 99 mg/l or higher was 90.3 % specific for complicated appendicitis. In patients with admission CRP less than 99 mg/l, the incidence of perforation doubled from 9.5 to 18.9 % when the in-hospital delay increased from less than 6 h to more than 12 h.

CONCLUSIONS

Complicated appendicitis can be identified with a high CRP level on admission. Delaying surgery can increase the risk of perforation.

Appendicitis

INTRODUCTION

Appendicitis is an inflammation of the appendix that may lead to an abscess, ileus, peritonitis, or death if untreated. Appendicitis is the most common abdominal surgical emergency. The current standard treatment of uncomplicated appendicitis is usually surgery, but there has been increasing evidence published on the use of antibiotics.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical question: What are the effects of surgery compared with antibiotics for acute appendicitis? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2014 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found four studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of surgery (including laparoscopic and open appendicectomy) compared with antibiotics.

Pediatric appendicitis in a developing country: what are the clinical predictors and outcome of perforation?

OBJECTIVES

This study explored the risk factors and outcomes associated with perforation in children who underwent emergency appendicectomies.

METHODS

A retrospective cross-sectional study was conducted on children <13 years old who underwent appendicectomies in a Malaysian hospital in 2007.

RESULTS

One hundred thirty-four children underwent appendicectomies of which 118 were confirmed histologically. Sixty-one (52%) were perforated. Children with perforation had significantly longer duration of symptoms (p < 0.001), higher white cell count and absolute neutrophil counts (p = 0.013), with longer intra-operative period (p < 0.001) and post-operative recovery period (p < 0.001). Of the 52 samples of pus collected intra-operatively, 37 (71.1%) yielded positive cultures that were predominantly Escherichia coli (n = 27). Both the patients who had Staphylococcus aureus cultured from pus collected intra-operatively had significant pyogenic complications (scrotal pyocele and intra-abdominal abscess).

CONCLUSION

Children whose appendicitis were perforated had longer duration of symptoms, higher white cell counts and absolute neutrophil counts. Those with S.aureus cultured from intra-operative pus appeared to suffer more complications.

A Comparative Study of RIPASA Score and ALVARADO Score in the Diagnosis of Acute Appendicitis

BACKGROUND

Acute appendicitis is one of the most common surgical emergencies. Different techniques have been devised to assist in equivocal cases in attempts to decrease negative appendicectomy rates. A number of scoring systems have been used for aiding in early diagnosis of acute appendicitis and its prompt management of which Alvarado score is the most popular. The accuracy of Alvarado score in the diagnosis of acute appendicitis is disappointingly low in Asian population and RIPASA scoring has been designed for the diagnosis of acute appendicitis in the Asian population. So we prospectively applied and compared Alvarado and RIPASA score in the diagnosis of acute appendicitis in Indian population.

MATERIALS AND METHODS

We compared prospectively RIPASA and Alvarado scoring system by applying them to 206 patients. Both scores were calculated for patients who presented with right iliac fossa pain during the study period. Depending on clinical judgment appendicectomy was done. Post operative histopathology report was correlated with the scores. A score of 7.5 is the optimal cut off threshold for RIPASA and 7 for Alvarado scoring system. Sensitivity, specificity, positive predictive value (PPV) and negative predictive (NPV) for RIPASA & Alvarado system was done.

RESULTS

The sensitivity and specificity of RIPASA score were 96.2% and 90.5% respectively. The sensitivity and specificity of Alvarado score were 58.9% and 85.7% respectively. RIPASA score correctly classified 96 percent of all patients confirmed with histological acute appendicitis to the high probability group (RIPASA score greater than 7.5) compared with 58.9% with Alvarado score (Alvarado score greater than 7.0; p-value less than 0.001).

CONCLUSION

RIPASA scoring system is more convenient, accurate, and specific scoring system for Indian population than Alvarado scoring system.

Time to appendectomy and risk of perforation in acute appendicitis

IMPORTANCE

In the traditional model of acute appendicitis, time is the major driver of disease progression; luminal obstruction leads inexorably to perforation without timely intervention. This perceived association has long guided clinical behavior related to the timing of appendectomy.

OBJECTIVE

To evaluate whether there is an association between time and perforation after patients present to the hospital.

DESIGN, SETTING, AND PARTICIPANTS

Using data from the Washington State Surgical Care and Outcomes Assessment Program (SCOAP), we evaluated patterns of perforation among patients (≥18 years) who underwent appendectomy from January 1, 2010, to December 31, 2011. Patients were treated at 52 diverse hospitals including urban tertiary centers, a university hospital, small community and rural hospitals, and hospitals within multi-institutional organizations.

MAIN OUTCOMES AND MEASURES

The main outcome of interest was perforation as diagnosed on final pathology reports. The main predictor of interest was elapsed time as measured between presentation to the hospital and operating room (OR) start time. The relationship between in-hospital time and perforation was adjusted for potential confounding using multivariate logistic regression. Additional predictors of interest included sex, age, number of comorbid conditions, race and/or ethnicity, insurance status, and hospital characteristics such as community type and appendectomy volume.

RESULTS

A total of 9048 adults underwent appendectomy (15.8% perforated). Mean time from presentation to OR was the same (8.6 hours) for patients with perforated and nonperforated appendicitis. In multivariate analysis, increasing time to OR was not a predictor of perforation, either as a continuous variable (odds ratio =  1.0 [95% CI, 0.99-1.01]) or when considered as a categorical variable (patients ordered by elapsed time and divided into deciles). Factors associated with perforation were male sex, increasing age, 3 or more comorbid conditions, and lack of insurance.

CONCLUSIONS AND RELEVANCE

There was no association between perforation and in-hospital time prior to surgery among adults treated with appendectomy. These findings may reflect selection of those at higher risk of perforation for earlier intervention or the effect of antibiotics begun at diagnosis but they are also consistent with the hypothesis that perforation is most often a prehospital occurrence and/or not strictly a time-dependent phenomenon. These findings may also guide decisions regarding personnel and resource allocation when considering timing of nonelective appendectomy.

Do Postoperative Antibiotics Prevent Abscess Formation in Complicated Appendicitis?

Recent studies have shown that postoperative antibiotics in nonperforated appendicitis do not reduce infectious complications; however, there is no consensus on patients with complicated appendicitis. The aim of this study is to determine whether postoperative antibiotic administration in complicated appendicitis prevents intra-abdominal abscess formation. We conducted a retrospective chart review of all patients undergoing appendectomy from 2007 to 2012 at our institution. Patients with complicated appendicitis (perforated, gangrenous, or periappendiceal abscess) were identified and data collected including details of postoperative antibiotic administration and rates of postoperative abscess development. Of 444 charts reviewed, 52 patients were included. Forty-four patients received greater than 24 hours and eight patients received 24 hours or less of postoperative antibiotics. In those receiving greater than 24 hours of antibiotics, nine of 44 (20.5%) developed a postoperative abscess, and in those receiving 24 hours or less of antibiotics, two of eight (25.0%) developed a postoperative abscess ( P = 1.0000). There is no significant difference in postoperative abscess development among those with complicated appendicitis who received greater than 24 hours of postoperative antibiotics compared with those who did not. Postoperative antibiotics may not provide an appreciable clinical benefit for preventing intra-abdominal abscesses; however, larger sample sizes and prospective studies are needed to confirm these findings.

A multicentre cohort study assessing day of week effect and outcome from emergency appendicectomy

BACKGROUND

There is evidence to suggest that patients undergoing treatment at weekends may be subject to different care processes and outcomes compared with weekdays. This study aimed to determine whether clinical outcomes from weekend appendicectomy are different from those performed on weekdays.

METHOD

Multicentre cohort study during May-June 2012 from 95 centres (89 within the UK). The primary outcome was the 30-day adverse event rate. Multilevel modelling was used to account for clustering within hospitals while adjusting for case mix to produce adjusted ORs and 95% CIs.

RESULTS

When compared with Monday, there were no significant differences for other days of the week considering 30-day adverse events in adjusted models. On Sunday, rates of simple appendicitis were highest, and rates of normal (OR 0.62, 95% CI 0.42 to 0.90) and complex appendicitis (OR 0.65, 95% CI 0.46 to 0.93) lowest. This was accompanied by a 43% lower likelihood in use of laparoscopy on Sunday (OR 0.47, 95% CI 0.32 to 0.69), accompanied by the lowest level of consultant presence for the week. When pooling weekends and weekdays, laparoscopy use remained less likely at the weekend (OR 0.68, 95% CI 0.55 to 0.83), with no significant difference for 30-day adverse event rate (OR 1.01, 95% CI 0.80 to 1.29).

CONCLUSIONS

This study found that weekend appendicectomy was not associated with increased 30-day adverse events. It cannot rule out smaller increases that may be shown by larger studies. It further illustrated that patients operated on at weekends were subject to different care processes, which may expose them to risk.

Safety of short, in-hospital delays before surgery for acute appendicitis: multicentre cohort study, systematic review, and meta-analysis

OBJECTIVE

To determine safety of short in-hospital delays before appendicectomy.

BACKGROUND

Short organizational delays before appendicectomy may safely improve provision of acute surgical services.

METHODS

The primary endpoint was the rate of complex appendicitis (perforation, gangrene, and/or abscess). The main explanatory variable was timing of surgery, using less than 12 hours from admission as the reference. The first part of this study analyzed primary data from a multicentre study on appendicectomy from 95 centers. The second part combined this data with a systematic review and meta-analysis of published data.

RESULTS

The cohort study included 2510 patients with acute appendicitis, of whom 812 (32.4%) had complex findings. Adjusted multivariable binary regression modelling showed that timing of operation was not related to risk of complex appendicitis [12-24 hours odds ratio (OR) 0.98 (P = 0.869); 24-48 hours OR 0.88 (P = 0.329); 48+ hours OR 0.82 (P = 0.317)]. However, after 48 hours, the risk of surgical site infection and 30-day adverse events both increased [adjusted ORs 2.24 (P = 0.039) and 1.71 (P = 0.024), respectively]. Meta-analysis of 11 nonrandomized studies (8858 patients) revealed that delay of 12 to 24 hours after admission did not increase the risk of complex appendicitis (OR 0.97, P = 0.750).

CONCLUSIONS

Short delays of less than 24 hours before appendicectomy were not associated with increased rates of complex pathology in selected patients. These organizational delays may aid service provision, but planned delay beyond this should be avoided. However, where optimal surgical systems allow for expeditious surgery, prompt appendicectomy will still aid fastest resolution of pain for the individual patient.

Long-term outcomes of patients with nonsurgically managed uncomplicated appendicitis

BACKGROUND

Emerging literature has supported the safety of nonoperative management of uncomplicated appendicitis.

STUDY DESIGN

Patients with emergent, uncomplicated appendicitis were identified by appropriate ICD-9 diagnosis codes in the California Office of Statewide Health Planning and Development database from 1997 to 2008. Rates of treatment failure, recurrence, and perforation after nonsurgical management were calculated. Factors associated with treatment failure, recurrence, and perforation were identified using multivariable logistic regression. Mortality, length of stay, and total charges were compared between treatment cohorts using matched propensity score analysis.

RESULTS

Of 231,678 patients with uncomplicated appendicitis, the majority (98.5%) were managed operatively. Of the 3,236 nonsurgically managed patients who survived to discharge without an interval appendectomy, 5.9% and 4.4% experienced treatment failure or recurrence, respectively, during a median follow-up of more than 7 years. There were no mortalities associated with treatment failure or recurrence. The risk of perforation after discharge was approximately 3%. Using multivariable analysis, race and age were significantly associated with the odds of treatment failure. Sex, age, and hospital teaching status were significantly associated with the odds of recurrence. Age and hospital teaching status were significantly associated with the odds of perforation. Matched propensity score analysis indicated that after risk adjustment, mortality rates (0.1% vs 0.3%; p = 0.65) and total charges ($23,243 vs $24,793; p = 0.70) were not statistically different between operative and nonoperative patients; however, length of stay was significantly longer in the nonoperative treatment group (2.1 days vs 3.2 days; p < 0.001).

CONCLUSIONS

This study suggests that nonoperative management of uncomplicated appendicitis can be safe and prompts additional investigations. Comparative effectiveness research using prospective randomized studies can be particularly useful.

Causes and costs of a decade of litigation following emergency appendectomy in England

BACKGROUND

There has been recent interest in the delayed and nonoperative management of appendicitis. The present study assessed the causes and costs of litigation against surgeons following emergency appendectomy, with an emphasis on claims relating to preoperative management.

MATERIALS AND METHODS

Data were obtained from the English NHS Litigation Authority for claims relevant to appendectomy between 2002 and 2011. Two authors independently extracted data and classified it against predetermined criteria.

RESULTS

Successful litigation occurred in 66 % of closed cases (147/223) with a total payout of £8.1 million. There were 24 claims against organizational operating room delays (9 % of total) and 27 against delayed diagnosis (10 %), with respective success rates of 70 and 68 %. From 21 claims relating to damage to fertility, nine were due to either delayed diagnosis or organizational operating room delays. Misdiagnosis was the second most common cause for litigation (16 %), but it had the lowest likelihood of success (49 %). Faulty surgical technique was the most common reason for litigation (39 %), with a 70 % likelihood of success. Of eight claims related to fatality, one was due to unacceptable preoperative delay leading to preventable perforated appendicitis. The overall highest median payouts were for claims of damage to fertility (£52,384), operating list delays (£44,716), and delayed diagnosis (£42,292).

CONCLUSIONS

There were significant medicolegal risks surrounding delays related to access to operating lists and diagnosis. Whereas future evidence regarding the safety of delayed appendectomy may provide scientific defense against these claims, the present study provides evidence of the current medicolegal risk to surgeons following delayed treatment of appendicitis.

Laparoscopic appendectomy: State of the art. Tailored approach to the application of laparoscopic appendectomy?

Acute appendicitis is the most common surgical emergency in developed countries. The treatment of acute appendicitis is either open or laparoscopic appendectomy. The latter has gained wide acceptance in the past years, although the debate on the true merits of laparoscopic appendectomy is still on going. Some authors prefer this approach as the gold standard for all patients, but in our opinion a tailored approach is warranted for specific patient groups. In addition, a standardised guideline on the technical aspects is still lacking. In the current article, open versus laparoscopic appendectomy and several technical aspects, such as stump closure, appendix extraction and single incision are discussed laparoscopic appendectomy are being addressed. In the future perspectives we will briefly discuss the third 'newly' introduced antibiotic treatment.

Beyond acute appendicitis: imaging and pathologic spectrum of appendiceal pathology

While acute appendicitis is a common and important clinical problem, a variety of other disease processes can affect the appendix. Simple and perforated appendicitis, tip appendicitis, and stump appendicitis share a common clinical presentation including anorexia, right lower quadrant pain, and fever. By imaging, most cases of acute appendicitis exhibit luminal dilation, wall thickening, and periappendiceal inflammatory stranding. In tip appendicitis, these changes are isolated to the distal appendix, often with an obstructing appendicolith. Perforated appendicitis can exhibit mural discontinuity, periappendiceal abscess, and/or extraluminal appendicoliths. After appendectomy, the appendiceal remnant or "stump" can become inflamed, often necessitating repeat surgery. Inflammatory bowel disease can involve the terminal ileum, secondarily involving the appendix, or may primarily involve the appendix. Patient symptoms can be chronic in such cases, and mucosal hyperenhancement is a pronounced imaging feature. In asymptomatic patients without appendiceal inflammation, the appendix can be dilated by intraluminal material such as inspissated succus in cystic fibrosis or mucus from benign appendiceal mucocele. Finally, neoplasms such as typical appendiceal carcinoid tumor and mucinous adenocarcinoma can involve the appendix. Carcinoids are often small and incidentally discovered at pathologic examination, while malignant mucinous adenocarcinoma tends to present with advanced disease including pseudomyxoma peritonei. Cecal cancers can also obstruct the appendiceal lumen and cause acute appendicitis; an astute radiologist can recognize this prospectively and facilitate definitive resection (right hemicolectomy) at the time of surgery. Attention to mural features, cecal configuration, and periappendiceal inflammation is essential to the correct prospective diagnosis of complicated appendicitis and less common appendiceal pathologies.

Improvement in the diagnosis of appendicitis

Our attempts to systematically improve accuracy in the evaluation of patients with suspected appendicitis are, in some ways, hindered by the fact that the condition is so frequently straightforward to diagnose. Careful history-taking and physical examination are reliable in most patients. However, establishing the diagnosis with these skills alone remains vulnerable to conditions that masquerade as acute appendicitis. A substantial body of clinical research over the last quarter-century has shown that improved accuracy is possible. Strategies for improvement include the use of diagnostic scoring systems, laboratory makers such as CRP, diagnostic laparoscopy, and advanced imaging modalities such as CT, MRI, and US. How clinicians use these strategies depends on many factors related to practice setting, the population served, and clinical goals. In children, for instance, the desire to limit exposure to ionizing radiation competes with the greater anatomic detail that a CT scan can provide; at the same time, many hospitals that treat children do not have the resources to maintain the sort of full-time, highly sophisticated abdominal US programs that achieve the highest rates of diagnostic accuracy in clinical studies. Trade-offs have to be made, but improvement is possible in almost all groups of patients: the clinical community should no longer settle for a 15% NA rate when 5% is clearly possible without adverse consequences. Many clinicians will be faced with the task of evaluating patients suspected of having acute appendicitis. A deliberate, proactive, and, ideally, benchmarked strategy for improving diagnosis should be the standard to which we hold ourselves and the promise we deliver to our patients.

Delay to surgery does not influence the pathological outcome of acute appendicitis

INTRODUCTION

Emergency surgery is performed on patients with appendicitis in the belief that inflammation of the appendix may progress to necrosis and perforation. Many cases of appendicitis, however, resolve with conservative treatment, and necrotic appendicitis may represent a different disease rather than the end result of inflammation of the appendix. We wished to explore the relationship between the interval to surgery after admission to hospital with appendicitis and the proportion of patients developing necrosis.

METHODS

Appendicectomy operations performed between 2005 and 2010 were reviewed. End points included age, sex, interval from admission to surgery, and final pathological diagnosis.

RESULTS

A total of 2403 evaluable patients were identified (1266 females). Necrotic appendicitis occurred more commonly in children (17.5%) and the elderly (25.4%) compared with adults (10.5%). The median interval to surgery of patients with normal histology (17.1 h) was longer than the time to removal of inflamed (13 h) or necrotic (13.5 h) appendices (p < 0.001).The ratio of necrotic to inflamed appendicitis in the entire cohort was 0.24. Multivariate analysis reveals that necrosis of the appendix is more common in children and the elderly and that the proportion of patients with necrosis does not change with increasing interval to surgery.

DISCUSSION

Our observations show that appendicitis is not more likely to lead to perforation if a short delay prior to surgery is allowed. In addition, our findings add weight to the increasing volume of data showing that necrosis of the appendix is a disease different from simple inflammation.

Inter-rater concordance of wound classifications in patients undergoing appendectomy

BACKGROUND

Despite the widespread utilization of a four-stage wound classification system to risk-adjust operations for surgical site infection (SSI) rates, we are not aware of any study evaluating the definitions of the wound classes for clarity. We limited our study of wound classifications to appendectomies and posed the question whether different reviewers classify individual cases differently.

METHODS

We evaluated the wound classifications of 105 consecutive appendectomies in our community hospital. Four reviewers graded retrospectively the wound classifications, first after reading the description of the appendix in the operative report and again after reading the pathology report. The wound classifications of the four reviewers were evaluated for concordance with the original operating room nurse (ORN) assignment.

RESULTS

The kappa scores for inter-observer concordance of wound classifications among the four reviewers based on their interpretation of the operative report and the ORN who originally classified the operation ranged from 0.1028 to 0.1597. By conventional standards, this represents no better than "slight agreement" for any of the reviewers. We found that 19%, 50%, 94%, 95%, or 96% of our appendectomies would be considered "high risk," Class 3 or 4, operations depending on which rater classified the operation. The additional information contained in the pathology reports did not change the distribution of wound classifications of the four reviewers significantly.

CONCLUSIONS

Our study demonstrated considerable differences in the distribution of wound classifications of appendectomies among our ORNs and retrospective reviewers. A review of the surgical literature supports our finding that the incision classification system utilized commonly lacks precision, at least in the rating of appendectomies. We recommend that further studies be performed to determine whether changes in the definitions of wound classes are warranted.

Management of Complicated Appendicitis in the Pediatric Population: When Surgery Doesn't Cut It

The management of complicated appendicitis in children has evolved significantly over the last century. What initially was a surgeon's dilemma is becoming the interventional radiologist's task because image-guided percutaneous drainage of abscesses from a ruptured appendix obviates the need for urgent surgery and allows for selective interval appendectomy at the surgeon's discretion (versus conservative nonoperative management in selected cases). This paradigm shift places the onus on the interventional radiologist to recognize when the procedure is emergently indicated and to be cognizant of the special needs of a pediatric patient.

Ultrasound assessment of acute appendicitis in paediatric patients: methodology and pictorial overview of findings seen

Acute appendicitis is a common surgical emergency in the paediatric population. Computed tomography (CT) has been shown to have high accuracy and low operator dependence in the diagnosis of appendicitis. However, with increased concerns regarding CT usage in children, ultrasound (US) is the imaging modality of choice in patients where appendicitis is suspected. This review describes and illustrates the step-wise graded-compression technique for the visualisation of the appendix, the normal and pathological appearances of the appendix, as well as the imaging characteristics of the common differentials.

• A step-wise technique improves the chances of visualisation of the appendix.

• There are often several causes for the non-visualisation of the appendix in children.

• A pathological appendix has characteristic US signs, with several secondary features also identified.

• There are multiple common differentials to consider in the paediatric patient.

Multicentre observational study of performance variation in provision and outcome of emergency appendicectomy

BACKGROUND

Identification of variation in practice is a key step towards standardization of service and determination of reliable quality markers. This study aimed to investigate variation in provision and outcome of emergency appendicectomy.

METHODS

A multicentre, trainee-led, protocol-driven, prospective observational cohort study was performed during May and June 2012. The main outcome of interest was the normal histopathology rate; secondary outcomes were laparoscopy and 30-day adverse event rates. Analysis included funnel plots and binary logistic regression models to identify patient- and hospital-related predictors of outcome.

RESULTS

A total of 3326 patients from 95 centres were included. An initial laparoscopic approach was performed in 66.3 per cent of patients (range in centres performing more than 25 appendicectomies over the study period: 8.7-100 per cent). A histologically normal appendix was removed in 20.6 per cent of patients (range in centres performing more than 25 procedures: 3.3-36.8 per cent). Funnel plot analysis revealed that 22 centres fell below three standard deviations of the mean for laparoscopy rates. Higher centre volume, consultant presence in theatre and daytime surgery were independently associated with an increased use of laparoscopy, which in turn was associated with a reduction in 30-day morbidity (adjusted for disease severity). Daytime surgery further reduced normal appendicectomy rates. Increasing volume came at the cost of higher negative rates, and low negative rates came at the cost of higher perforation rates.

CONCLUSION

This study reveals the extremely wide variation in practice patterns and outcomes among hospitals. Organizational factors leading to this variation have been identified and should be addressed to improve performance.

Acute appendicitis in the twenty-first century: should we modify the management protocol?

BACKGROUND

Recent data challenge the traditional management of acute appendicitis with early surgical intervention. This study evaluated the impact of timing of appendectomy and other potential risk factors on progression of acute appendicitis.

STUDY DESIGN

A search of the relevant databases of a tertiary medical center identified 1,604 patients with verified acute appendicitis who underwent appendectomy in 2004-2007. Demographic and clinical data and time from symptom onset to emergency room admission ("patient interval") and from emergency room admission to surgery ("hospital interval") and their combination were analyzed by pathological grade.

RESULTS

On multivariate analyses, independent risk factors for appendiceal perforation were age <20 years (OR = 1.58, 95 % CI 1.07-2.35) or >50 years (OR = 2.84, 95 % CI 1.82-4.45) (relative to 20-50 years), white cell count >10 × 103/mm(3) (OR = 4.45, 95 % CI 2.05-9.67), body temperature >37.8 °C (OR = 2.23, 95 % CI 1.45-3.41), hospital interval >24 h (OR = 2.84, 95 % CI 1.49-5.4), patient interval >48 h (OR = 3.84, 95 % CI 2.35-6.29), and combined interval >48 h (OR = 4.29, 95 % CI 2.2-8.36). No association with perforation was found for the hour of emergency room arrival, hour of operation, surgical approach, or the performance of preoperative imaging.

CONCLUSIONS

In the general population, the risk of advanced pathological grade of appendicitis increases with time. Thus, prompt appendectomy is warranted. Prospective studies of subgroups of perforated and nonperforated appendicitis are needed.

Ambient ozone concentrations and the risk of perforated and nonperforated appendicitis: a multicity case-crossover study

BACKGROUND

Environmental determinants of appendicitis are poorly understood. Past work suggests that air pollution may increase the risk of appendicitis.

OBJECTIVES

We investigated whether ambient ground-level ozone (O3) concentrations were associated with appendicitis and whether these associations varied between perforated and nonperforated appendicitis.

METHODS

We based this time-stratified case-crossover study on 35,811 patients hospitalized with appendicitis from 2004 to 2008 in 12 Canadian cities. Data from a national network of fixed-site monitors were used to calculate daily maximum O3 concentrations for each city. Conditional logistic regression was used to estimate city-specific odds ratios (ORs) relative to an interquartile range (IQR) increase in O3 adjusted for temperature and relative humidity. A random-effects meta-analysis was used to derive a pooled risk estimate. Stratified analyses were used to estimate associations separately for perforated and nonperforated appendicitis.

RESULTS

Overall, a 16-ppb increase in the 7-day cumulative average daily maximum O3 concentration was associated with all appendicitis cases across the 12 cities (pooled OR = 1.07; 95% CI: 1.02, 1.13). The association was stronger among patients presenting with perforated appendicitis for the 7-day average (pooled OR = 1.22; 95% CI: 1.09, 1.36) when compared with the corresponding estimate for nonperforated appendicitis [7-day average (pooled OR = 1.02, 95% CI: 0.95, 1.09)]. Heterogeneity was not statistically significant across cities for either perforated or nonperforated appendicitis (p > 0.20).

CONCLUSIONS

Higher levels of ambient O3 exposure may increase the risk of perforated appendicitis.

Outpatient antibiotic use and the incidence of acute appendicitis in Finland: a nationwide study from 1990-2008

BACKGROUND

The incidence of acute appendicitis (AA) has decreased in Finland. We hypothesized that changing trends in outpatient antibiotic use might explain at least part of this declining incidence of AA.

METHODS

The number of all patients with AA in Finland was extracted from the national data base from 1990 to 2008. For comparison, the incidence of acute diverticulitis of the colon (AD) was also recorded. All outpatient prescriptions of antibiotics belonging to the major groups of these drugs were also recorded. We used unit root and co-integration analyses for statistical analysis of the data in the study.

RESULTS

The incidence of AA in Finland declined from 14.5 to 9.8 per 10,000 inhabitants (32%) and the incidence of AD increased by 47% between 1993 and 2007. The total outpatient use of antibiotics did not increase during this same period, but the use of antibiotics effective widely against colonic pathogens (macrolides, fluoroquinolones, and cephalosporins) increased significantly. No correlation was found between the incidence of AA, that of AD, and the use of different groups of antibiotics.

CONCLUSIONS

Our nationwide registry study indicated that changes in outpatient antibiotic use do not explain the decreasing trend in AA in Finland. Other factors, such as improved diagnosis of AA, may have some role in the decreasing incidence of AA.

Treatment options of inflammatory appendiceal masses in adults

At present, the treatment of choice for uncomplicated acute appendicitis in adults continues to be surgical. The inflammation in acute appendicitis may sometimes be enclosed by the patient's own defense mechanisms, by the formation of an inflammatory phlegmon or a circumscribed abscess. The management of these patients is controversial. Immediate appendectomy may be technically demanding. The exploration often ends up in an ileocecal resection or a right-sided hemicolectomy. Recently, the conditions for conservative management of these patients have changed due to the development of computed tomography and ultrasound, which has improved the diagnosis of enclosed inflammation and made drainage of intra-abdominal abscesses easier. New efficient antibiotics have also given new opportunities for nonsurgical treatment of complicated appendicitis. The traditional management of these patients is nonsurgical treatment followed by interval appendectomy to prevent recurrence. The need for interval appendectomy after successful nonsurgical treatment has recently been questioned because the risk of recurrence is relatively small. After successful nonsurgical treatment of an appendiceal mass, the true diagnosis is uncertain in some cases and an underlying diagnosis of cancer or Crohn's disease may be delayed. This report aims at reviewing the treatment options of patients with enclosed appendiceal inflammation, with emphasis on the success rate of nonsurgical treatment, the need for drainage of abscesses, the risk of undetected serious disease, and the need for interval appendectomy to prevent recurrence.

Examining a common disease with unknown etiology: trends in epidemiology and surgical management of appendicitis in California, 1995-2009

BACKGROUND

The study was designed to examine the epidemiology of appendicitis and risk factors of perforation and appendectomy.

METHODS

Retrospective analysis of the California Office of Statewide Health Planning and Development Patient Discharge Data was performed from 1995 to 2009. Patients with appendicitis were identified by ICD-9 diagnosis code. Population statistics from the RAND Corporation were used to calculate incidence rates. Risk factors of perforation and appendectomy were also calculated.

RESULTS

A total of 608,116 patients with appendicitis (70% non-perforated) were included. The incidence increased at an average rate of 0.5 cases/100,000 population/year (p<0.001), with annual incidence peaking during the third quarter. Children age 10-14 had the highest rates of appendicitis (169.6 cases/100,000). The lifetime cumulative incidence rate is 9.0%. Appendicitis is most common in whites and Hispanics and less common in African Americans and Asians. Risks of perforation include Hispanic or Asian race, young or old age, and non-private insurance. The adjusted odds of appendectomy increased since 1995 in patients with non-perforated appendicitis (OR 1.5, 95% CI (1.3-1.7); p<0.001), but it decreased in patients with perforated appendicitis (OR 0.4, 95% CI (0.4-0.5); p<0.001).

CONCLUSIONS

This is the largest epidemiological study of appendicitis to our knowledge in recent years. Incidence has increased over time and is higher in the summer months. Whites and Hispanics have higher rates of appendicitis, but Hispanics and Asians and patients with non-private insurance, have higher odds of perforation. Surgical management of perforated appendicitis has decreased over time. It is unknown why the incidence has increased, displays seasonality, and varies by race.

Risk of perforation increases with delay in recognition and surgery for acute appendicitis

BACKGROUND

Appendicitis remains a common indication for urgent surgical intervention in the United States, and early appendectomy has long been advocated to mitigate the risk of appendiceal perforation. To better quantify the risk of perforation associated with delayed operative timing, this study examines the impact of length of inpatient stay preceding surgery on rates of perforated appendicitis in both adults and children.

METHODS

This study was a cross-sectional analysis using the National Inpatient Sample and Kids' Inpatient Database from 1988-2008. We selected patients with a discharge diagnosis of acute appendicitis (perforated or nonperforated) and receiving appendectomy within 7 d after admission. Patients electively admitted or receiving drainage procedures before appendectomy were excluded. We analyzed perforation rates as a function of both age and length of inpatient hospitalization before appendectomy.

RESULTS

Of 683,590 patients with a discharge diagnosis of appendicitis, 30.3% were recorded as perforated. Over 80% of patients underwent appendectomy on the day of admission, approximately 18% of operations were performed on hospital days 2-4, and later operations accounted for <1% of cases. During appendectomy on the day of admission, the perforation rate was 28.8%; this increased to 33.3% for surgeries on hospital day 2 and 78.8% by hospital day 8 (P<0.001). Adjusted for patient, procedure, and hospital characteristics, odds of perforation increased from 1.20 for adults and 1.08 for children on hospital day 2 to 4.76 for adults and 15.42 for children by hospital day 8 (P<0.001).

CONCLUSIONS

Greater inpatient delay before appendectomy is associated with increased perforation rates for children and adults within this population-based study. These findings align with previous studies and with the conventional progressive pathophysiologic appendicitis model. Randomized prospective studies are needed to determine which patients benefit from nonoperative versus surgically aggressive management strategies for acute appendicitis.

Risk of perforation increases with delay in recognition and surgery for acute appendicitis

BACKGROUND

Appendicitis remains a common indication for urgent surgical intervention in the United States, and early appendectomy has long been advocated to mitigate the risk of appendiceal perforation. To better quantify the risk of perforation associated with delayed operative timing, this study examines the impact of length of inpatient stay preceding surgery on rates of perforated appendicitis in both adults and children.

METHODS

This study was a cross-sectional analysis using the National Inpatient Sample and Kids' Inpatient Database from 1988-2008. We selected patients with a discharge diagnosis of acute appendicitis (perforated or nonperforated) and receiving appendectomy within 7 d after admission. Patients electively admitted or receiving drainage procedures before appendectomy were excluded. We analyzed perforation rates as a function of both age and length of inpatient hospitalization before appendectomy.

RESULTS

Of 683,590 patients with a discharge diagnosis of appendicitis, 30.3% were recorded as perforated. Over 80% of patients underwent appendectomy on the day of admission, approximately 18% of operations were performed on hospital days 2-4, and later operations accounted for <1% of cases. During appendectomy on the day of admission, the perforation rate was 28.8%; this increased to 33.3% for surgeries on hospital day 2 and 78.8% by hospital day 8 (P<0.001). Adjusted for patient, procedure, and hospital characteristics, odds of perforation increased from 1.20 for adults and 1.08 for children on hospital day 2 to 4.76 for adults and 15.42 for children by hospital day 8 (P<0.001).

CONCLUSIONS

Greater inpatient delay before appendectomy is associated with increased perforation rates for children and adults within this population-based study. These findings align with previous studies and with the conventional progressive pathophysiologic appendicitis model. Randomized prospective studies are needed to determine which patients benefit from nonoperative versus surgically aggressive management strategies for acute appendicitis.

Computed tomography mimics of acute appendicitis: predictors of appendiceal disease confirmed at pathology

Purpose:

Imaging and pathology findings are used to analyze the capability of computed tomography (CT) to distinguish between acute appendicitis and radiological mimickers.

Materials and Methods:

A retrospective review of 5861 patients undergoing abdominopelvic CT from 2000 to 2008 for suspicion of acute appendicitis was performed. Appendix diameter, surrounding inflammation, appendicolith, and location were assessed. Only those cases were included where patients underwent surgery for acute appendicitis on CT findings. Pathology specimens were examined and those indicative of acute appendicitis were identified. Statistical analysis was performed to correlate pathology and CT signs.

Results:

A total of 969 of the 5681 patients were included in the study. Acute appendicitis was verified in 870/969 (89%) cases, while 99/969 (11%) demonstrated either chronic findings (i.e., fibrosis [32%], granulomatous disease [16%], lymphoid hyperplasia [11%]) or no abnormality. In regression models, appendiceal diameter >7 mm (odds ratio [OR] = 3.98, P < 0.0001) and mesenteric fat stranding (OR = 6.04, P < 0.0001) were associated with acute appendicitis. Nearly 87% (754/870) of acute appendicitis cases showed both signs on CT, compared with 53% (52/99) of those with other pathologic finding (P < 0.0001). In cases with non-appendicitis findings, 39% (39/99) had only one of these signs compared with 13% (112/870) of those with acute appendicitis (P < 0.0001).

Conclusion:

Diseases of the appendix other than acute appendicitis may manifest with isolated radiological findings and should be considered as part of the differential diagnosis in cases of borderline acute appendicitis.

Bacterial studies of complicated appendicitis over a 20-year period and their impact on empirical antibiotic treatment

BACKGROUND

Multiresistant bacterial strains tend to develop, especially enterobacteriacae, in intraabdominal infections. The aim of this study was to characterize the evolution of the bacterial biota in complicated appendicitis in children over the past 20 years and their acquired resistance rates to antibiotics.

MATERIALS AND METHODS

All pediatric patients admitted in the emergency unit for complicated appendicitis were retrospectively reviewed during 3 periods: 1989 to 1991, 1999 to 2000, and 2009 to 2010. Results of peritoneal swabs were analyzed regarding bacterial species and resistance to antibiotics. Statistical significance was set at P < .05.

RESULTS

Thirty-four, 48, and 85 patients from the 3 periods, respectively, were included, with 1 to 6 bacterial strains found in each peritoneal sample. During the first period, 80% of the biota was composed of enterobacteriacae and anaerobes and then decreased to 65%, whereas streptococci levels increased from 0 to 22%. Pansusceptibility rates remained stable (17%, 16.8%, and 15.6% for the 3 periods, respectively). Piperacillin, vancomycin, ticarcillin-clavulanic acid, and fluoroquinolones were associated with increased resistance rates, unlike antibiotic associations currently used as postoperative treatments.

CONCLUSION

No significant increase in resistance rates of bacteriacae in complicated appendicitis in children was found over the last 20 years. Empirical antibiotherapy protocols currently recommended remain efficient on this particular biota.

The association of body mass index and perforation of the appendix in Puerto Rican children

OBJECTIVE

Puerto Rico Department of Health lacks data on appendicitis since 1996. We inquired about factors influencing perforation.

METHODS

Retrospective study of risk factors among Puerto Rican children with appendicitis from 2002-2008.

RESULTS

One hundred and seventy records were reviewed. Appendiceal perforation = 38%. Median age was 10 years. Risk factors for perforation were age younger than five years, onset of symptoms more than 36 hours previously, public insurance, more than two examiners, and public hospital. Obese patients had a tendency to present with perforation (OR: 1.5 (0.6-3.5)). In the multivariate analysis, the only variables that remained significant were age younger than five years (OR: 10.2 (2.2-46.7)), and onset of symptoms more than 36 hours previously (OR: 5.9 (2.3-14.7)).

CONCLUSION

Age younger than five years and onset of symptoms more than 36 hours previously were associated with perforation of the appendix. Body mass index for age percentile greater than the 95th had a tendency to present with perforation.