Precisión de la prueba diagnóstica de acentuación de la cefalea mediante sacudidas cefálicas para el diagnóstico de meningitis aguda en urgencias / Diagnostic test accuracy of jolt accentuation for headache in acute meningitis in the emergency setting

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Application of MALDI-TOF MS to assess clinical characteristics, risk factors, and outcomes associated with anaerobic bloodstream infection: a retrospective observational study.

BACKGROUND: Correctly identifying anaerobic bloodstream infections (BSIs) is difficult. However, a new technique, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), enables more accurate identification and appropriate treatment. Anaerobic BSIs identified by MALDI-TOF MS were retrospectively analyzed to determine the clinical and microbiological features and patient outcomes based on the anaerobic genera or group. METHODS: Medical records of patients with anaerobic BSIs were used to conduct a single-center retrospective cohort study from January 2016 to December 2020 in Nagoya, Japan. Multivariate logistic regression analysis was performed to determine the independent risk factors for in-hospital mortality. RESULTS: Of the 215 patients with anaerobic BSIs, 31 had multiple anaerobic organisms in the blood culture, including 264 total episodes of anaerobic BSIs. Bacteroides spp. were isolated the most (n = 74), followed by gram-positive non-spore-forming bacilli (n = 57), Clostridium spp. (n = 52), gram-positive anaerobic cocci (GPAC) (n = 27), and gram-negative cocci (n = 7). The median patient age was 76 years; 56.7% were male. The most common focal infection site was intra-abdominal (36.7%). The in-hospital mortality caused by anaerobic BSIs was 21.3%, and was highest with Clostridium spp. (36.5%) and lowest with GPAC (3.7%). Age, solid tumors, and Clostridium spp. were independent risk factors for in-hospital mortality. CONCLUSIONS: We identified current anaerobic BSI trends using MALDI-TOF MS and reported that mortality in patients with anaerobic BSIs patients was highest with Clostridium spp. infections.

Clinical characteristics of bloodstream infection by Parvimonas micra: retrospective case series and literature review.

BACKGROUND: Gram-positive anaerobic (GPA) bacteria inhabit different parts of the human body as commensals but can also cause bacteremia. In this retrospective observational study, we analyzed GPA bacteremia pathogens before (2013-2015) and after (2016-2018) the introduction of the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). METHOD: We conducted a retrospective observational study by searching the microbiology database to identify all positive GPA blood cultures of patients with GPA bacteremia diagnosed using the new technique, MALDI-TOF MS, between January 1, 2016 and December 31, 2018; and using a conventional phenotypic method between January 1, 2013 and December 31, 2015 at a single tertiary center in Japan. Parvimonas micra (P. micra) (17.5%) was the second most frequently identified GPA (MALDI-TOF MS); we then retrospectively reviewed electronic medical records for 25 P. micra bacteremia cases at our hospital. We also conducted a literature review of published cases in PubMed from January 1, 1980, until December 31, 2019; 27 cases were retrieved. RESULTS: Most cases of P. micra bacteremia were identified after 2015, both, at our institute and from the literature review. They were of mostly elderly patients and had comorbid conditions (malignancies and diabetes). In our cases, laryngeal pharynx (7/25, 28%) and gastrointestinal tract (GIT; 6/25, 24%) were identified as the most likely sources of bacteremia; however, the infection source was not identified in 9 cases (36%). P. micra bacteremia were frequently associated with spondylodiscitis (29.6%), oropharyngeal infection (25.9%), intra-abdominal abscess (14.8%), infective endocarditis (11.1%), septic pulmonary emboli (11.1%), and GIT infection (11.1%) in the literature review. Almost all cases were treated successfully with antibiotics and by abscess drainage. The 30-day mortalities were 4 and 3.7% for our cases and the literature cases, respectively. CONCLUSIONS: Infection sites of P. micra are predominantly associated with GIT, oropharyngeal, vertebral spine, intra-abdominal region, pulmonary, and heart valves. Patients with P. micra bacteremia could have good prognosis following appropriate treatment.

Diagnostic test accuracy of jolt accentuation for headache in acute meningitis in the emergency setting.

BACKGROUND: Meningitis is inflammation of the meninges, the layers that protect the brain and spinal cord. Acute meningitis is an emergent disease that develops over the course of hours to several days. Delay in treatment can lead to serious outcomes. Inflammation of the meninges is assessed by analysing cerebrospinal fluid. Identifying the pathogen in cerebrospinal fluid is another way to diagnose meningitis. Cerebrospinal fluid is collected by doing a lumbar puncture, which is an invasive test, and can be avoided if a physical examination excludes the diagnosis of meningitis. However, most physical examinations, such as nuchal rigidity, Kernig's test, and Brudzinski's test, are not sufficiently sensitive to exclude meningitis completely. Jolt accentuation of headache is a new and less well-recognised physical examination, which assesses meningeal irritation. It is judged as positive if the headache is exacerbated by rotating the head horizontally two or three times per second. A 1991 observational study initially reported high sensitivity of this examination to predict pleocytosis. Pleocytosis, an abnormally high cerebrospinal fluid sample white cell count, is an accepted indicator of nervous system infection or inflammation. Jolt accentuation of headache may therefore accurately rule out meningitis without the use of lumbar puncture. However, more recent cross-sectional studies have reported variable diagnostic accuracy. OBJECTIVES: To estimate the diagnostic accuracy of jolt accentuation of headache for detecting acute meningitis in emergency settings. Secondary objectives: to investigate the sources of heterogeneity, including study population, patient condition, and types of meningitis. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), and Embase (Elsevier) to 27 April 2020. We searched ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, and Ichushi-Web Version 5.0 to 28 April 2020. SELECTION CRITERIA: We included cross-sectional studies that assessed the diagnostic accuracy of jolt accentuation of headache for people with suspected meningitis in emergency settings. We included participants of any age and any severity of illness. Meningitis should be diagnosed with any reference standard, such as cerebrospinal fluid pleocytosis, proof of causative agents, or autopsy. DATA COLLECTION AND ANALYSIS: Two review authors independently collated study data. We assessed methodological quality of studies using QUADAS-2 criteria. We used a bivariate random-effects model to determine summary estimates of sensitivity and specificity where meta-analysis was possible. We performed sensitivity analyses to validate the robustness of outcomes. We assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS: We included nine studies (1161 participants). Five studies included only adults. Four studies included both adults and children; however, the proportion was not reported in three of these studies. The youngest child reported in the studies was aged 13 years. There was no study including only children. The reference standard was pleocytosis in eight studies, and the combination of pleocytosis and increased protein in the cerebrospinal fluid in one study. Two studies also used smear or positive culture of cerebrospinal fluid. Risk of bias and concern about applicability was high in the participant selection domain for all included studies and the consciousness subgroup. Overall, pooled sensitivity was 65.3% (95% confidence interval (CI) 37.3 to 85.6), and pooled specificity was 70.4% (95% CI 47.7 to 86.1) (very low-certainty evidence). We established the possibility of heterogeneity from visual inspection of forest plots. However, we were unable to conduct further analysis for study population, types of meningitis, and participants' condition, other than disturbance of consciousness (a secondary outcome). Amongst participants whose consciousness was undisturbed (8 studies, 921 participants), pooled sensitivity and specificity were 75.2% (95% CI 54.3 to 88.6) and 60.8% (95% CI 43.4 to 75.9), respectively (very low-certainty evidence). AUTHORS' CONCLUSIONS: Jolt accentuation for headache may exclude diagnoses of meningitis in emergency settings, but high-quality evidence to support use of this test is lacking. Even where jolt accentuation of headache is negative, there is still the possibility of acute meningitis. This review identified the possibility of heterogeneity. However, factors that contribute to heterogeneity are incompletely understood, and should be considered in future research.

Association between sarcopenia and sleep disorder in older patients with diabetes.

AIM: In the present study, we aimed to examine the association between sarcopenia and sleep disorder in older patients with diabetes using the Japanese version of SARC-F (SARC-F-J). METHODS: Outpatients with diabetes (aged ≥65 years) at the Ise Red Cross Hospital were included in the present study. We used the Japanese version of the Pittsburgh Sleep Quality Index, which is a self-administered questionnaire, to measure sleep disorder. To evaluate sarcopenia, we used SARC-F-J, a self-administered questionnaire, comprising five items. For multiple logistic regression analysis, the dependent variable was sleep disorder and the explanatory variable was sarcopenia, and these were used for calculating the odds ratios of sarcopenia with regard to sleep disorder. RESULTS: In total, 318 patients were included in this study (189 men and 129 women). The prevalence of sarcopenia was 22.5% and that of sleep disorder was 44.8%. Adjusted odds ratios of sarcopenia and sleep disorder were 6.04 in men (95% CI 1.71-21.36, P = 0.005) and 6.33 in women (95% CI 1.91-20.97, P = 0.003). CONCLUSIONS: We found a statistically significant association between sarcopenia and sleep disorder in older patients with diabetes using SARC-F-J. Therefore, older patients with diabetes should be cautioned regarding sleep disorder if they are diagnosed with sarcopenia. Geriatr Gerontol Int 2019; 19: 399-403.

Septic pulmonary embolism associated with periodontal disease: a case report and literature review.

BACKGROUND: Periodontal disease, including periodontitis, has been reported to be a rare cause of septic pulmonary embolism (SPE). It is however extremely difficult to isolate the causative pathogen of periodontal disease-associated SPE from blood cultures of these patients. CASE PRESENTATION: In this study, an 85-year-old Japanese man was admitted with fever and worsening malaise. He was later noted to have multiple bilateral subpleural pulmonary nodules on chest computed tomography scan. After admission, Parvimonas micra (P. micra) was isolated from his blood culture. This was followed by a meticulous search for the primary source of SPE, focusing on the head and neck areas. Consequently, apical periodontitis and infratemporal fossa abscess were identified as the primary sources of SPE. Although P. micra is one of the most frequently detected bacteria in the infected root canals of teeth with chronic apical periodontitis, it has rarely been proven as a causative pathogen of periodontal disease-associated SPE. CONCLUSIONS: This case study demonstrated that periodontal disease is an important primary source of SPE and P. micra could be a causative pathogen of SPE.

Evidence-based clinical practice guidelines for inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a chronic disorder involving mainly the intestinal tract, but possibly other gastrointestinal and extraintestinal organs. Although etiology is still uncertain, recent knowledge in pathogenesis has accumulated, and novel diagnostic and therapeutic modalities have become available for clinical use. Therefore, the previous guidelines were urged to be updated. In 2016, the Japanese Society of Gastroenterology revised the previous versions of evidence-based clinical practice guidelines for ulcerative colitis (UC) and Crohn's disease (CD) in Japanese. A total of 59 clinical questions for 9 categories (1. clinical features of IBD; 2. diagnosis; 3. general consideration in treatment; 4. therapeutic interventions for IBD; 5. treatment of UC; 6. treatment of CD; 7. extraintestinal complications; 8. cancer surveillance; 9. IBD in special situation) were selected, and a literature search was performed for the clinical questions with use of the MEDLINE, Cochrane, and Igaku Chuo Zasshi databases. The guidelines were developed with the basic concept of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Recommendations were made using Delphi rounds. This English version was produced and edited based on the existing updated guidelines in Japanese.

Tokyo Guidelines 2018: flowchart for the management of acute cholecystitis.

We propose a new flowchart for the treatment of acute cholecystitis (AC) in the Tokyo Guidelines 2018 (TG18). Grade III AC was not indicated for straightforward laparoscopic cholecystectomy (Lap-C). Following analysis of subsequent clinical investigations and drawing on Big Data in particular, TG18 proposes that some Grade III AC can be treated by Lap-C when performed at advanced centers with specialized surgeons experienced in this procedure and for patients that satisfy certain strict criteria. For Grade I, TG18 recommends early Lap-C if the patients meet the criteria of Charlson comorbidity index (CCI) ≤5 and American Society of Anesthesiologists physical status classification (ASA-PS) ≤2. For Grade II AC, if patients meet the criteria of CCI ≤5 and ASA-PS ≤2, TG18 recommends early Lap-C performed by experienced surgeons; and if not, after medical treatment and/or gallbladder drainage, Lap-C would be indicated. TG18 proposes that Lap-C is indicated in Grade III patients with strict criteria. These are that the patients have favorable organ system failure, and negative predictive factors, who meet the criteria of CCI ≤3 and ASA-PS ≤2 and who are being treated at an advanced center (where experienced surgeons practice). If the patient is not considered suitable for early surgery, TG18 recommends early/urgent biliary drainage followed by delayed Lap-C once the patient's overall condition has improved. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Tokyo Guidelines 2018: surgical management of acute cholecystitis: safe steps in laparoscopic cholecystectomy for acute cholecystitis (with videos).

In some cases, laparoscopic cholecystectomy (LC) may be difficult to perform in patients with acute cholecystitis (AC) with severe inflammation and fibrosis. The Tokyo Guidelines 2018 (TG18) expand the indications for LC under difficult conditions for each level of severity of AC. As a result of expanding the indications for LC to treat AC, it is absolutely necessary to avoid any increase in bile duct injury (BDI), particularly vasculo-biliary injury (VBI), which is known to occur at a certain rate in LC. Since the Tokyo Guidelines 2013 (TG13), an attempt has been made to assess intraoperative findings as objective indicators of surgical difficulty; based on expert consensus on these difficulty indicators, bail-out procedures (including conversion to open cholecystectomy) have been indicated for cases in which LC for AC is difficult to perform. A bail-out procedure should be chosen if, when the Calot's triangle is appropriately retracted and used as a landmark, a critical view of safety (CVS) cannot be achieved because of the presence of nondissectable scarring or severe fibrosis. We propose standardized safe steps for LC to treat AC. To achieve a CVS, it is vital to dissect at a location above (on the ventral side of) the imaginary line connecting the base of the left medial section (Segment 4) and the roof of Rouvière's sulcus and to fulfill the three criteria of CVS before dividing any structures. Achieving a CVS prevents the misidentification of the cystic duct and the common bile duct, which are most commonly confused. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholecystitis (with videos).

The Tokyo Guidelines 2013 (TG13) for acute cholangitis and cholecystitis were globally disseminated and various clinical studies about the management of acute cholecystitis were reported by many researchers and clinicians from all over the world. The 1st edition of the Tokyo Guidelines 2007 (TG07) was revised in 2013. According to that revision, the TG13 diagnostic criteria of acute cholecystitis provided better specificity and higher diagnostic accuracy. Thorough our literature search about diagnostic criteria for acute cholecystitis, new and strong evidence that had been released from 2013 to 2017 was not found with serious and important issues about using TG13 diagnostic criteria of acute cholecystitis. On the other hand, the TG13 severity grading for acute cholecystitis has been validated in numerous studies. As a result of these reviews, the TG13 severity grading for acute cholecystitis was significantly associated with parameters including 30-day overall mortality, length of hospital stay, conversion rates to open surgery, and medical costs. In terms of severity assessment, breakthrough and intensive literature for revising severity grading was not reported. Consequently, TG13 diagnostic criteria and severity grading were judged from numerous validation studies as useful indicators in clinical practice and adopted as TG18/TG13 diagnostic criteria and severity grading of acute cholecystitis without any modification. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Tokyo Guidelines 2018: antimicrobial therapy for acute cholangitis and cholecystitis.

Antimicrobial therapy is a mainstay of the management for patients with acute cholangitis and/or cholecystitis. The Tokyo Guidelines 2018 (TG18) provides recommendations for the appropriate use of antimicrobials for community-acquired and healthcare-associated infections. The listed agents are for empirical therapy provided before the infecting isolates are identified. Antimicrobial agents are listed by class-definitions and TG18 severity grade I, II, and III subcategorized by clinical settings. In the era of emerging and increasing antimicrobial resistance, monitoring and updating local antibiograms is underscored. Prudent antimicrobial usage and early de-escalation or termination of antimicrobial therapy are now important parts of decision-making. What is new in TG18 is that the duration of antimicrobial therapy for both acute cholangitis and cholecystitis is systematically reviewed. Prophylactic antimicrobial usage for elective endoscopic retrograde cholangiopancreatography is no longer recommended and the section was deleted in TG18. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Tokyo Guidelines 2018: management strategies for gallbladder drainage in patients with acute cholecystitis (with videos).

Since the publication of the Tokyo Guidelines in 2007 and their revision in 2013, appropriate management for acute cholecystitis has been more clearly established. Since the last revision, several manuscripts, especially for alternative endoscopic techniques, have been reported; therefore, additional evaluation and refinement of the 2013 Guidelines is required. We describe a standard drainage method for surgically high-risk patients with acute cholecystitis and the latest developed endoscopic gallbladder drainage techniques described in the updated Tokyo Guidelines 2018 (TG18). Our study confirmed that percutaneous transhepatic gallbladder drainage should be considered the first alternative to surgical intervention in surgically high-risk patients with acute cholecystitis. Also, endoscopic transpapillary gallbladder drainage or endoscopic ultrasound-guided gallbladder drainage can be considered in high-volume institutes by skilled endoscopists. In the endoscopic transpapillary approach, either endoscopic naso-gallbladder drainage or gallbladder stenting can be considered for gallbladder drainage. We also introduce special techniques and the latest outcomes of endoscopic ultrasound-guided gallbladder drainage studies. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Effectiveness of Helicobacter pylori eradication in the prevention of primary gastric cancer in healthy asymptomatic people: A systematic review and meta-analysis comparing risk ratio with risk difference.

BACKGROUND: Helicobacter pylori infection is strongly associated with gastric cancer occurrence. However, it is unclear whether eradication therapy reduces the risk of gastric cancer occurrence. We evaluated whether H. pylori eradication reduces the risk of primary gastric cancer by using both risk ratio (RR) and risk difference (RD). METHODS: Searches of PubMed, EMBASE, Google scholar, the Cochrane Library, and the Japan Medical Abstracts Society as well as those registered in databases of the Cochrane Central Register of Controlled Trials, metaRegister of Controlled Trials, ClinicalTrials.gov, controlled-trials.com, UMIN-CTR, JMACCT-CTR, and JAPIC-CTI between January 1965 and March 2017, supplemented with manual screening. Randomized controlled trials (RCTs) in which eradication therapy were implemented for the interventional group but not for the control group, and assessed the subsequent occurrence of primary gastric cancer as the main outcome. Two authors independently reviewed articles and extracted data. Integrated results for all data were presented as RR and RD. RESULTS: Seven studies met inclusion criteria. The reductions in risk of primary gastric cancer occurrence in terms of overall RR and RD were 0.67 (95% CI: 0.48 to 0.95) and -0.00 ([95% CI: -0.01 to 0.00]; number needed to treat: 125.5 [95% CI: 70.0 to 800.9]), respectively. CONCLUSIONS: The effectiveness of H. pylori eradication therapy in suppressing the occurrence of primary gastric cancer was significant and comparable to that of previous studies in terms of the estimated RR. However, the estimated RD was slight and not statistically significant.

Pathological background of subcortical hyperintensities on diffusion-weighted images in a case of neuronal intranuclear inclusion disease.

AIMS: Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder with eosinophilic intranuclear inclusion bodies. The variable symptoms of NIID increase the difficulty in an antemortem diagnosis. NIID shows leukoencephalopathy on brain magnetic resonance imaging MRI, but the significance of the radiological findings have not been clarified. METHODS: We examined an autopsied case of NIID with subcortical linear hyperintensities on diffusion weighted imaging (DWI) and leukoencephalopathy on fluid attenuation inversion recovery (FLAIR) imaging. Semiquantitative analysis was performed by merging coronal sections of DWI and identical hematoxylin-eosin (H & E) stained brain specimens. The severity of spongiotic changes, the common pathological findings of NIID, were quantified and compared with MRI lesions classified by DWI signals. RESULTS: The white matter showed diffuse myelin pallor, and multiple focal spongiotic changes were present in the subcortical white matter proximal to the U-fibers. Spongiotic changes were restricted in the lesions with subcortical linear DWI high signals. CONCLUSION: Subcortical DWI high signals in NIID strongly correlate with pathological spongiotic changes of NIID. Subcortical spongiotic changes may be a characteristic finding of NIID.
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Systematic review of motor evoked potentials monitoring during thoracic and thoracoabdominal aortic aneurysm open repair surgery: a diagnostic meta-analysis.

Motor evoked potential (MEP) monitoring has been used to prevent neurological complications such as paraplegia in patients who underwent thoracic or thoracoabdominal aortic aneurysm (TAA/TAAA) surgery. The object of this study was making a systematic review to survey the performance of MEP monitoring during TAA/TAAA open repair surgery. We searched electronic databases for relevant studies. We summarized the diagnostic data with summary sensitivity, summary specificity and forest plots of pooled sensitivity, and conducted sub-group analysis. The quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. We also surveyed the reporting rate of clinical key factors such as methods of anesthesia, surgery, and success rate of MEP. Nineteen studies met our criteria. The results of meta-analysis showed 89.1 % summary sensitivity (95 % confidence interval 47.9-98.6 %) and 99.3 % summary specificity (95 % confidence interval 96.1-99.9 %). Sub-group analysis of pooled sensitivity and specificity by all-or-none cut-off point were better than other cut-off points. The results of the QUADAS-2 were not good. The performance of MEP monitoring was good for detecting postoperative paraplegia in TAA/TAAA open repair surgery. The cut-off point of all-or-none may be the best, according to our review.

Identifying Patients with Bacteremia in Community-Hospital Emergency Rooms: A Retrospective Cohort Study.

OBJECTIVES: (1) To develop a clinical prediction rule to identify patients with bacteremia, using only information that is readily available in the emergency room (ER) of community hospitals, and (2) to test the validity of that rule with a separate, independent set of data. DESIGN: Multicenter retrospective cohort study. SETTING: To derive the clinical prediction rule we used data from 3 community hospitals in Japan (derivation). We tested the rule using data from one other community hospital (validation), which was not among the three "derivation" hospitals. PARTICIPANTS: Adults (age ≥ 16 years old) who had undergone blood-culture testing while in the ER between April 2011 and March 2012. For the derivation data, n = 1515 (randomly sampled from 7026 patients), and for the validation data n = 467 (from 823 patients). ANALYSIS: We analyzed 28 candidate predictors of bacteremia, including demographic data, signs and symptoms, comorbid conditions, and basic laboratory data. Chi-square tests and multiple logistic regression were used to derive an integer risk score (the "ID-BactER" score). Sensitivity, specificity, likelihood ratios, and the area under the receiver operating characteristic curve (i.e., the AUC) were computed. RESULTS: There were 241 cases of bacteremia in the derivation data. Eleven candidate predictors were used in the ID-BactER score: age, chills, vomiting, mental status, temperature, systolic blood pressure, abdominal sign, white blood-cell count, platelets, blood urea nitrogen, and C-reactive protein. The AUCs was 0.80 (derivation) and 0.74 (validation). For ID-BactER scores ≥ 2, the sensitivities for derivation and validation data were 98% and 97%, and specificities were 20% and 14%, respectively. CONCLUSIONS: The ID-BactER score can be computed from information that is readily available in the ERs of community hospitals. Future studies should focus on developing a score with a higher specificity while maintaining the desired sensitivity.

Evidence of surgical outcomes fluctuates over time: results from a cumulative meta-analysis of laparoscopic versus open appendectomy for acute appendicitis.

BACKGROUND: In surgical trials, complex variables such as equipment development and surgeons' learning curve are involved. The evidence obtained in these trials can thus fluctuate over time. We explored the stability of the evidence obtained during surgery by conducting a cumulative meta-analysis of randomized controlled trials for open and laparoscopic appendectomy. METHODS: We conducted a cumulative meta-analysis of randomized controlled trials comparing laparoscopic appendectomy with open appendectomy for acute appendicitis, a topic with the greatest number of trials in the gastroenterological surgical field. We searched the MEDLINE (PubMed), EMBASE, and CINAHL databases up to September 2014 and reviewed the bibliographies. Outcomes were the incidence of intra-abdominal abscess, incidence of wound infection, operative time, and length of hospital stay. We used the 95 % confidence interval (95 % CI) of effect size for the significance test. RESULTS: Sixty-four trials were included in this analysis. Of the 51 trials addressing intra-abdominal abscesses, our cumulative meta-analysis of trials published up to and including 2001 demonstrated statistical significance in favor of open appendectomy (cumulative odds ratio [OR] 2.35, 95 % CI 1.30-4.25). The effect size in favor of open procedures began to disappear after 2001, leading to an insignificant result with an overall cumulative OR of 1.32 (95 % CI 0.84-2.10) when laparoscopic appendectomy was compared with open appendectomy. CONCLUSIONS: The evidence regarding treatment effectiveness changed over time, after treatment effectiveness became significant in trials comparing laparoscopic and open appendectomy. Observing only the 95 % confidence interval of effect size from a meta-analysis may not provide conclusive results.