Enhanced Th17 responses in the appendix of children with complex compared to simple appendicitis are associated with microbial dysbiosis.

Introduction: Appendicitis is one of the most common causes of acute abdominal surgery in children. The clinical course of appendicitis ranges from simple to complex appendicitis. The mechanisms underlying the heterogeneity of appendicitis in children remain largely unclear. Dysregulated T cell responses play an important role in several inflammatory diseases of the intestine, but the extend of T cell dysregulation in appendicitis in children is less well known. Methods: To characterize appendiceal T cells in simple and complex appendicitis we performed in-depth immunophenotyping of appendiceal-derived T cells by flow cytometry and correlated this to appendiceal-derived microbiota analyses of the same patient. Results: Appendix samples of twenty children with appendicitis (n = 8 simple, n = 12 complex) were collected. T cells in complex appendicitis displayed an increased differentiated phenotype compared to simple appendicitis, including a loss of both CD27 and CD28 by CD4+ T cells and to a lesser extent by CD8+ T cells. Frequencies of phenotypic tissue-resident memory CD69+CD4+ T cells and CD69+CD8+ T cells were decreased in children with complex compared to simple appendicitis, indicating disruption of local tissue-resident immune responses. In line with the increased differentiated phenotype, cytokine production of in particular IL-17A by CD4+ T cells was increased in children with complex compared to simple appendicitis. Furthermore, frequencies of IL-17A+ CD4+ T cells correlated with a dysregulation of the appendiceal microbiota in children with complex appendicitis. Conclusion: In conclusion, disruption of local T cell responses, and enhanced pro-inflammatory Th17 responses correlating to changes in the appendiceal microbiota were observed in children with complex compared to simple appendicitis. Further studies are needed to decipher the role of a dysregulated network of microbiota and Th17 cells in the development of complex appendicitis in children.

The potential of rectal swabs to differentiate simple and complex appendicitis in children with a microbiota-based test.

Currently, accurate biomarkers differentiating simple (phlegmonous) from complex (gangrenous and/or perforated) appendicitis in children are lacking. However, both types may potentially require different treatment strategies, and the search for diagnostic modalities remains warranted. Previously, we demonstrated a distinct microbiota (both an increased bacterial diversity and abundance) in the appendix of children with complex compared to simple appendicitis. From the same cohort of patients we have collected 35 rectal swabs under general anesthesia prior to appendectomy and microbiota analysis was performed by IS-pro, a 16S-23S rDNA-based clinical microbiota profiling technique. Using the obtained IS-profiles, we performed cluster analyses (UPGMA), comparison of diversity (Shannon Diversity Index) and intensity (abundance in relative fluorescence units) on phylum level, and comparison on species level of bacteria between simple and complex appendicitis. Regarding these analyses, we observed no clear differences between simple and complex appendicitis. However, increased similarity of the microbial composition of the appendix and rectal swab was found within children with complex compared to simple appendicitis. Furthermore, PLS-DA regression analysis provided clear visual differentiation between simple and complex appendicitis, but the diagnostic power was low (highest AUC 0.65).   Conclusion: Microbiota analysis of rectal swabs may be viable to differentiate between simple and complex appendicitis prior to surgery as a supervised classification model allowed for discrimination of both types. However, the current diagnostic power was low and further validation studies are needed to assess the value of this method. What is Known: • Simple and complex appendicitis in children may require different treatment strategies, but accurate preoperative biomarkers are lacking. • Clear differentiation can be made between both types in children based upon the microbial composition in the appendix. What is New: • Increased similarity was found between the microbial composition of the appendix and rectal swab within children with complex compared to simple appendicitis. • Using a supervised classification model rectal swabs may be viable to discriminate between simple and complex appendicitis, but the diagnostic power was low.

A Role of brachytherapy in bilateral Wilms tumors: A long-term follow-up of three highly selected cases and literature review.

PURPOSE: To describe experience with partial nephrectomy combined with brachytherapy as part of the local management of bilateral Wilms tumor (WT) including a review of the available literature. RESULTS (METHODS AND CASE DESCRIPTION): Between 2011 and 2014, three highly selected patients (age nine months, 16 months, and 4 years) with bilateral WT (two synchronous and one metachronous) underwent enucleation and perioperative brachytherapy to the tumor bed. With a minimum follow-up of 5 years, all three patients are in continuous complete remission with preserved kidney function. CONCLUSIONS: Although nephron sparing surgery aiming at tumor free-margins remains the gold standard for bilateral WT, tumor enucleation followed by brachytherapy may be considered in carefully selected patients at high risk for end-stage kidney failure. Given the rarity and complexity of the procedure, concentration of care of such patients is mandatory.

Microbiota of Children With Complex Appendicitis: Different Composition and Diversity of The Microbiota in Children With Complex Compared With Simple Appendicitis.

BACKGROUND: Two types of appendicitis are hypothesized, simple and complex, with potential different treatment strategies. To improve differentiation, underlying pathogeneses need to be further unraveled. AIM: To determine if the microbial composition in the appendix differs between children with simple and complex appendicitis. METHODS: Two-center, prospective cohort study including 40 children (0-17 years old) undergoing appendectomy for suspected appendicitis. Appendix tissue was used for IS-pro analysis to identify bacterial species by their length of 16S-23S rDNA interspacer (IS) region. Cluster analysis, based on IS-profiles, and correspondence with type of appendicitis, using Fisher exact test, was performed. Simple and complex appendicitis were compared regarding bacterial presence, intensity and diversity, using Fisher exact test and Mann-Whitney U test, respectively. RESULTS: Appendicitis was confirmed in 36 of 40 patients (16 simple, 20 complex). Cluster analysis identified 2 clusters, encompassing 34 patients. Distribution of simple and complex appendicitis was 12 (80%) and 3 (20%) versus 3 (16%) and 16 (84%) patients for clusters 1 and 2, respectively (P < 0.001). Complex appendicitis was on phylum level characterized by an increased intensity (Bacteroidetes P = 0.001, Firmicutes, Actinobacteria, Fusobacteria and Verrucomicrobia (FAFV) P = 0.005 and Proteobacteria P < 0.001) and diversity (Bacteroidetes P = 0.001 and Proteobacteria P = 0.016) and an increased abundance of 5 species (Alistipes finegoldii P = 0.009, Bacteroides fragilis P = 0.002, Escherichia coli P = 0.014, Parvimonas micra P = 0.022 and Sutterella spp P = 0.026). CONCLUSIONS: The microbial composition of the appendix differs between children with simple and complex appendicitis, regarding both composition and diversity. Future research should focus on the role of these bacteria in the pathogenesis of both types and its implications for preoperative diagnostics.

Evaluation of needle biopsy as a potential risk factor for local recurrence of Wilms tumour in the SIOP WT 2001 trial.

RATIONALE: The impact of biopsying Wilms tumour (WT) at diagnosis on assigning the tumour stage and recommended treatment remains controversial. To address this important question, we analysed the potential association of all types of biopsy with local recurrence in patients treated in the SIOP WT 2001 trial, where needle biopsy was permitted without 'upstaging' the tumour to stage III. Only open biopsy required treatment as stage III. METHODS: Among 2971 patients with unilateral WT (stages I-IV), 420 relapsed (139 local). Risk factors for recurrence were analysed by Cox proportional hazard methods. RESULTS: Biopsy was performed in 969 of 2971 (33%) patients (64% cutting needle, 30% fine needle aspiration [FNA] and 6% open biopsy). Biopsied patients were older, with larger tumours and a greater proportion with high-risk histology. In multivariate analysis that included all factors associated with local recurrence in univariate analysis, only high-risk histology (hazard ratio [HR] = 2.32; 95% confidence interval [CI]: 1.58-3.42, p=<0.0001), age≥2 years (HR = 2.24; 95% CI: 1.22-4.09, p = 0.01) and preoperative tumour volume (HR = 1.07 per 100 ml; 95% CI: 1.02-1.12, p = 0.01) were significant. The HR for the association of local recurrence and event-free and overall survival with biopsy was not significant (HR = 1.4; 95% CI: 0.9-2.17, p = 0.13; HR = 1.1; 95% CI: 0.85-1.42, p = 0.46 and HR = 1.13; 95% CI: 0.79-1.62, p = 0.51, respectively). These results were not materially different whether FNA or open biopsy were included in the biopsy group or not. CONCLUSIONS: This post hoc analysis provides some reassurance that needle biopsy is not an independent adverse factor for either local recurrence or survival after adjustment for all relevant risk factors. Needle biopsy should not be an automatic criterion to 'upstage' WT.

Ruling out Appendicitis in Children: Can We Use Clinical Prediction Rules?

PURPOSE: To identify available clinical prediction rules (CPRs) and investigate their ability to rule out appendicitis in children presenting with abdominal pain at the emergency department, and accordingly select CPRs that could be useful in a future prospective cohort study. METHODS: A literature search was conducted to identify available CPRs. These were subsequently tested in a historical cohort from a general teaching hospital, comprising all children (< 18 years) that visited the emergency department between 2012 and 2015 with abdominal pain. Data were extracted from the electronic patient files and scores of the identified CPRs were calculated for each patient. The negative likelihood ratios were only calculated for those CPRs that could be calculated for at least 50% of patients. RESULTS: Twelve CPRs were tested in a cohort of 291 patients, of whom 87 (29.9%) suffered from acute appendicitis. The Ohmann score, Alvarado score, modified Alvarado score, Pediatric Appendicitis score, Low-Risk Appendicitis Rule Refinement, Christian score, and Low Risk Appendicitis Rule had a negative likelihood ratio < 0.1. The Modified Alvarado Scoring System and Lintula score had a negative likelihood ratio > 0.1. Three CPRs were excluded because the score could not be calculated for at least 50% of patients. CONCLUSION: This study identified seven CPRs that could be used in a prospective cohort study to compare their ability to rule out appendicitis in children and investigate if clinical monitoring and re-evaluation instead of performing additional investigations (i.e., ultrasound) is a safe treatment strategy in case there is low suspicion of appendicitis.

Higher incidence of surgery-related complications in Wilms tumor nephrectomy from clinical records analysis compared with central database registration.

BACKGROUND/OBJECTIVES: Central database registrations are widely used tools for assessment of clinical results, but their reliability is subject to debate. The aim of this study is to evaluate the reliability of central database registration for Wilms tumor (WT) nephrectomy-related complications. DESIGN/METHODS: All Dutch patients undergoing WT nephrectomy according to the International Society of Paediatric Oncology (SIOP) 2001 protocol between 2001 and 2013 were evaluated. Results from the central database were analyzed and compared with data found via individual medical records analysis (gold standard). RESULTS: A total of 179 patients were included. Fourteen (7.8%) patients with a total of 17 complications were identified in the central database. The medical records revealed that 33 (18.4%) of patients had undergone a total of 41 complications (P < 0.001). Operative complications were similar between the groups (P = 0.157). Eleven short-term complications were noted in the central database versus 27 in the medical records (P = 0.059). Significantly more long-term complications, namely, adhesive small-bowel obstruction, were noted from the medical records compared with the central database (7 vs 1, respectively, P < 0.001). Postoperative chemotherapy was significantly delayed by on average 6 days (P < 0.0001) in patients with complications. No significant effect of complications on event-free survival, overall survival, or the relapse rate was recorded. CONCLUSION: Central database registrations underestimate the incidence of surgery-related complications after WT nephrectomy and need to be regarded with caution.

Clinical recovery in children with uncomplicated appendicitis undergoing non-operative treatment: secondary analysis of a prospective cohort study.

Non-operative treatment of uncomplicated appendicitis in children is gaining ground. Pending definitive evidence regarding its effectiveness, there is a call to evaluate clinical recovery after non-operative treatment. In this study, we analyzed data collected during initial admission of a multicenter prospective cohort in which children, 7-17 year, were treated non-operatively for uncomplicated appendicitis. During admission clinical parameters (pain and gastro-intestinal symptoms), inflammation parameters and sequential abdominal ultrasound were recorded. In total, 45 children were included, 42(93%) were discharged without the need for appendectomy; median [IQR] pain scores on admission were 5 [4-7], decreasing to 2 [0-3] after 1 day of treatment. Initially, 28/42 (67%) reported nausea and 19/42 (45%) vomiting; after 1 day, this was 3/42 (7%) and 1/42 (2%), respectively. White blood cell count declined from a median [IQR] of 12.9 [10.7-16.7] 10E9/L on admission to 7.0 [5.8-9.9] 10E9/L on day 1. Median [IQR] C-reactive protein levels increased from 27.5 [9-69] mg/L on admission to 48 [22-80] mg/L on day 1, declining to 21.5 [11-42] mg/L on day 2. Follow-up ultrasound showed no signs of complicated appendicitis in any of the patients.Conclusion: Clinical symptoms resolved in most children after 1 day of non-operative treatment. This suggests that non-operative treatment is a viable alternative to appendectomy regarding clinical recovery.Trail registration: NCT01356641 What is Known: • Non-operative treatment of uncomplicated appendicitis in children is safe and its use around the world is gaining ground, however high quality evidence from adequately designed randomized trials is still lacking. • Concerns have been raised regarding the potentially prolonged clinical recovery associated with non-operative treatment. What is New: • Most clinical symptoms resolve after 1 day of non-operative treatment in the majority of children.

The incidence of associated abnormalities in patients with sacrococcygeal teratoma.

BACKGROUND: Gross genetic causes for SCT are unknown; however, it might be associated with other abnormalities. We assessed the incidence of associated abnormalities in a large national cohort of neonates with SCT and aimed to identify predictive risk factors. PROCEDURE: The medical records were reviewed of 235 consecutive neonates with SCT treated at the six pediatric surgical centers in the Netherlands from 1970 to 2010. Potential risk factors for associated abnormalities analyzed included sex, gestational age, tumor-volume/histology and Altman-classification. RESULTS: In 76 patients (32.3%) at least one associated abnormality was diagnosed, with hydronephrosis as the most common (16.2%) and hip dysplasia in 4.3%. Multiple abnormalities were documented for 21 (9.0%). Prematurity and Altman type IV SCT were associated with an increased risk of any associated abnormality. No association between increased tumor-volume and hydronephrosis or hip dysplasia was found. Patients with type IV Altman SCT had a fourfold risk of suffering from hydronephrosis compared to Altman type I SCT. CONCLUSIONS: SCT was associated with other abnormalities in one-third of children. Some were tumor-related while others were related to prematurity or occurred sporadically. In contrast to clinically obvious anomalies, hip dysplasia or hydronephrosis might be latently present with more subtle clinical presentation. We therefore suggest renal- and hip-ultrasound in all patients, certainly those with Altman type IV SCT. LEVEL OF EVIDENCE RATING: Level II (retrospective study).

Outcome of initially nonoperative treatment for acute simple appendicitis in children.

PURPOSE: To compare the outcome of initially nonoperative treatment with immediate appendectomy for simple appendicitis in children. METHODS: Between September 2012 and June 2014 children aged 7-17 years with a radiologically confirmed simple appendicitis were invited to participate in a multicentre prospective cohort study in which they were treated with an initially nonoperative treatment strategy; nonparticipants underwent immediate appendectomy. In October 2015, their rates of complications and subsequent appendectomies, and health-related quality of life (HRQOL) were assessed. RESULTS: In this period, 25 children were treated with an initially nonoperative treatment strategy and 19 with immediate appendectomy; median (range) follow-up was 25 (16-36) and 26 (17-34) months, respectively. The percentage [95%CI] of patients experiencing complications in the initially nonoperative group and the immediate appendectomy group was 12 [4-30]% and 11 [3-31]%, respectively. In total 6/25 children (24%) underwent an appendectomy; none of the 6 patients operated subsequently experienced any postappendectomy complications. Overall, HRQOL in the nonoperative treatment group was similar to that of healthy peers. CONCLUSIONS: Outcome of initially nonoperative treatment for acute simple appendicitis in children is similar to the outcome in those who undergo immediate appendectomy. Initially nonoperative management seems to be able to avoid appendectomy in 3 out of 4 children. LEVEL OF EVIDENCE: 2 (prospective comparative study). This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.

Initial non-operative management of uncomplicated appendicitis in children: a protocol for a multicentre randomised controlled trial (APAC trial).

INTRODUCTION: Based on epidemiological, immunological and pathology data, the idea that appendicitis is not necessarily a progressive disease is gaining ground. Two types are distinguished: simple and complicated appendicitis. Non-operative treatment (NOT) of children with simple appendicitis has been investigated in several small studies. So far, it is deemed safe. However, its effectiveness and effect on quality of life (QoL) have yet to be established in an adequately powered randomised trial. In this article, we provide the study protocol for the APAC (Antibiotics versus Primary Appendectomy in Children) trial. METHODS AND ANALYSIS: This multicentre, non-inferiority, randomised controlled trial randomises children aged 7-17 years with imaging-confirmed simple appendicitis between appendectomy and NOT. Patients are recruited in 15 hospitals. The intended sample size, based on the primary outcome, rate of complications and a non-inferiority margin of 5%, is 334 patients.NOT consists of intravenous antibiotics for 48-72 hours, daily blood tests and ultrasound follow-up. If the patient meets the predefined discharge criteria, antibiotic treatment is continued orally at home. Primary outcome is the rate of complications at 1-year follow-up. An independent adjudication committee will assess all complications and their relation to the allocated treatment. Secondary outcomes include, but are not limited to, delayed appendectomies, QoL, pain and (in)direct costs.The primary outcome will be analysed both according to the intention-to-treat principle and the per-protocol principle, and is presented with a one-sided 97.5% CI. We will use multiple logistic and linear regression for binary and continuous outcomes, respectively, to adjust for stratification factors. ETHICS AND DISSEMINATION: The protocol has been approved by the Medical Ethics Review Committee of the Academic Medical Center, Amsterdam. Data monitoring is performed by an independent institute and a Data Safety Monitoring Board has been assigned. Results will be presented in peer-reviewed academic journals and at (international) conferences. TRIAL REGISTRATION NUMBER: NCT02848820; NTR5977; Pre-results.

Composition of the cellular infiltrate in patients with simple and complex appendicitis.

BACKGROUND: It is now well established that there are two types of appendicitis: simple (nonperforating) and complex (perforating). This study evaluates differences in the composition of the immune cellular infiltrate in children with simple and complex appendicitis. MATERIALS AND METHODS: A total of 47 consecutive children undergoing appendectomy for acute appendicitis between January 2011 and December 2012 were included. Intraoperative criteria were used to identify patients with either simple or complex appendicitis and were confirmed histopathologically. Immune histochemical techniques were used to identify immune cell markers in the appendiceal specimens. Digital imaging analysis was performed using Image J. RESULTS: In the specimens of patients with complex appendicitis, significantly more myeloperoxidase positive cells (neutrophils) (8.7% versus 1.2%, P < 0.001) were detected compared to patients with a simple appendicitis. In contrast, fewer CD8+ T cells (0.4% versus 1.3%, P = 0.016), CD20 + cells (2.9% versus 9.0%, P = 0.027), and CD21 + cells (0.2% versus 0.6%, P = 0.028) were present in tissue from patients with complex compared to simple appendicitis. CONCLUSIONS: The increase in proinflammatory innate cells and decrease of adaptive cells in patients with complex appendicitis suggest potential aggravating processes in complex appendicitis. Further research into the underlying mechanisms may identify novel biomarkers to be able to differentiate simple and complex appendicitis.

Systematic review of nonoperative versus operative treatment of uncomplicated appendicitis.

BACKGROUND: To compare the risk of complications between initial nonoperative treatment and appendectomy of uncomplicated (simple) appendicitis in children. METHODS: Systematic literature search. Eligible for inclusion were both and randomized controlled trials and cohort studies including children in which the outcome of nonoperative treatment of uncomplicated appendicitis was reported with a minimum follow-up period of one year. Two authors extracted data independently and assessed quality. Primary outcome parameter was the percentage of children experiencing complications. Secondary outcomes were early failures, recurrent appendicitis and appendectomies, for all indications and on request. RESULTS: Five of the 2051 articles screened were eligible for inclusion, including 147 children (nonoperative treatment) and 173 children (appendectomy) with one year follow-up. Percentage of children experiencing complications ranged from 0 to 13% versus 0-17% for nonoperative and appendectomy, respectively. Nonoperative treatment avoided an appendectomy in 62-81% of the children after one year follow-up. CONCLUSION: The evidence base for initial nonoperative treatment of acute uncomplicated appendicitis in children is by far insufficient. It suggests that the percentage of patients experiencing complications in the initial nonoperative treatment group is comparable to the appendectomy group, and it may avoid an appendectomy in the large majority of children after one year follow-up. TYPE OF STUDY: Systematic review. LEVEL OF EVIDENCE: 1.

Unexpected findings after surgery for suspected appendicitis rarely change treatment in pediatric patients; Results from a cohort study.

BACKGROUND: To determine if non-operative treatment is safe in children with acute appendicitis, we evaluated the incidence of unexpected findings after an appendectomy in children, and the influence they have on subsequent treatment. METHODS: A historical cohort study (January 2004-December 2014) was performed including children, aged 0-17 years, who underwent an appendectomy for the suspicion of acute appendicitis. Patients were divided based upon histopathological examination. Unexpected findings were reviewed, as well as the subsequent treatment plan. RESULTS: In total 484 patients were included in this study. In the overall group, unexpected findings were noted in 10 (2.1%) patients of which two patients intra-operatively with a non-inflamed appendix (Ileitis terminalis N=1 and ovarian torsion N=1) and in 8 patients on histopathological examination. The latter group consisted of 4 patients with concomitant simple appendicitis (parasitic infection N=3 and Walthard cell rest N=1), two with concomitant complex appendicitis (carcinoid N=1 and parasitic infection N=1) and two patients with a non-inflamed appendix (endometriosis N=1 and parasitic infection N=1). Treatment was changed in 4 patients (<1%). CONCLUSIONS: Results from this study corroborate the safety of non-operative strategy for acute simple appendicitis, as the occurrence of unexpected findings was low, with extremely few necessary changes of the treatment plan because of serious findings. TYPE OF STUDY: Prognosis study. LEVEL OF EVIDENCE: Level 2 (retrospective cohort study).

Surgical treatment of childhood hepatoblastoma in the Netherlands (1990-2013).

BACKGROUND: Achievement of complete surgical resection plays a key role in the successful treatment of children with hepatoblastoma. The aim of this study is to assess the surgical outcomes after partial liver resections for hepatoblastoma, focusing on postoperative complications, resection margins, 30-day mortality, and long-term survival. METHOD: Chart reviews were carried out on all patients treated for hepatoblastoma in the Netherlands between 1990 and 2013. RESULTS: A total of 103 patients were included, of whom 94 underwent surgery. Partial hepatectomy was performed in 76 patients and 18 patients received a liver transplant as a primary procedure. In 42 of 73 (58 %) patients, one or more complications were reported. In 3 patients, information regarding complications was not available. Hemorrhage necessitating blood transfusion occurred in 33 (45 %) patients and 9 (12 %) patients developed biliary complications, of whom 8 needed one or more additional surgical interventions. Overall, 5-year disease-specific survival was 82, 92 % in the group of patients who underwent partial hepatectomy, and 77 % in the group of patients who underwent liver transplantation. CONCLUSIONS: Partial hepatectomy after chemotherapy in children with hepatoblastoma offers good chances of survival. This type of major surgery is associated with a high rate of surgical complications (58 %), which is not detrimental to survival.

Hemorrhage is the most common cause of neonatal mortality in patients with sacrococcygeal teratoma.

BACKGROUND: A small percentage of neonates with sacrococcygeal teratoma die shortly after birth from hemorrhagic complications. The incidence of and risk factors associated with hemorrhagic mortality are unknown. In this multicenter study we determined the incidence of early death in neonates born with SCT and evaluated potential risk factors for hemorrhagic mortality. METHODS: 235 children with SCT treated from 1970 to 2010 in the Netherlands were retrospectively included. The following candidate risk factors for hemorrhagic mortality were examined: sex, prematurity, Altman type, tumor volume, tumor histology, necessity of emergency operation and time of diagnosis. RESULTS: Eighteen patients (7.7%) died at a median age of 163.5days (range 1.7-973days). Nine patients died of a malignancy. Nine others (3.8%) died postnatally (age 1-27days), six even within two days after birth. In seven of these nine patients death was related to tumor-hemorrhage and/or circulatory failure. Risk factors for hemorrhagic mortality were prematurity, tumor volume>1000cm3 and performance of an emergency operation. CONCLUSIONS: Hemorrhagic mortality of neonates with SCT is relatively high (3.8%) representing almost 70% of the overall mortality in the neonatal period. High-output cardiac failure, internal tumor hemorrhage and perioperative bleeding were the most common causes of early death and were all strongly associated with larger tumor sizes. LEVEL-OF-EVIDENCE RATING: II (Retrospective study).

Intervention not always necessary in post-appendectomy abscesses in children; clinical experience in a tertiary surgical centre and an overview of the literature.

UNLABELLED: This study aims to provide an overview of both our own experience and the available literature on the treatment of post-appendectomy abscess (PAA) in children. We performed a historical cohort study encompassing all children aged 0-17 years old treated for a radiologically confirmed PAA between 2007 and 2013. Their medical charts were reviewed and descriptive analyses were performed. A literature search on the treatment of PAA in children was performed. In our cohort, 25 out of 372 (7 %) children developed a PAA. Thirteen were treated with a noninvasive strategy and 12 with an invasive strategy (percutaneous or surgical drainage). The immediate success rate was 9/13 (69 %) and 8/12 (67 %) for the noninvasive and invasive strategy, respectively. In both groups, four children (31 and 33 % resp.) required delayed interventions after their initial treatment. In the literature review, six studies were included which reported a median (range) frequency of persistent or recurrent abscess of 9 % (0-30 %), 50 % (0-100 %) and 24 % (0-33 %) for the antibiotic (noninvasive), percutaneous drainage (invasive) and surgical drainage strategies, respectively. CONCLUSION: Although confounding by indication cannot be excluded, we recommend noninvasive treatment as a safe strategy for PAA in children with stable condition. WHAT IS KNOWN: • Post-appendectomy abscess is a well-known and feared complication, occurring in up to 24 % of the children treated surgically for appendicitis. • Several strategies are available to treat this condition, all with advantages and disadvantages. What is new: • Noninvasive strategy is a safe strategy for children with a PAA in a stable condition. • An overview of the literature (the first to our knowledge) supports the above-mentioned statement.

Prevalence of Symptomatic and Asymptomatic Thrombosis in Pediatric Oncology Patients With Tunneled Central Venous Catheters.

BACKGROUND: Pediatric oncology patients with tunneled central venous catheters (CVCs) are at increased risk to develop venous thromboembolic events (VTEs), but the true prevalence of (a)symptomatic VTE is unknown. Aim of this study was to evaluate the prevalence of (a)symptomatic VTE in pediatric oncology patients with tunneled CVCs. PROCEDURE: All patients were included in the Aristocaths study: a randomized controlled multicenter trial investigating the prophylactic effect of 70% ethanol locks on CVC-associated bloodstream infections (CABSIs) were eligible for this study. We assessed the following outcomes: (i) symptomatic VTE and (ii) asymptomatic CVC-related VTE (using ultrasound [US]). Follow-up was 6 months, unless patients developed one of the following events: VTE, CABSI, CVC removal, or death. RESULTS: We included 305 patients (hematologic malignancy, n = 148; solid tumor, n = 157), median age 9 years (range, 1-18 years). Symptomatic VTE was detected in 8 of 305 patients (2.6%; 95% confidence interval [CI]: 1.1-5.1%), which was related to the CVC in three patients. Patients (185/305) were evaluated with US: 11 of 185 (5.9%; 95% CI: 3.0-10.4%) patients had asymptomatic CVC-related VTE. CONCLUSIONS: Prevalence of both symptomatic VTE and asymptomatic CVC-related VTE was low compared to other studies, which may be explained by the inclusion of patients with solid tumors, reduction of CABSI by ethanol, use of tunneled CVCs, and use of US.

Patient-Reported Defecation and Micturition Problems Among Adults Treated for Sacrococcygeal Teratoma During Childhood--The Need for New Surveillance Strategies.

BACKGROUND: To evaluate defecation and micturition complaints in adults treated for sacrococcygeal teratoma (SCT) during childhood and to identify risk factors for soiling, urinary incontinence, and constipation beyond childhood. PROCEDURE: Records of patients aged ≥18 treated for SCT during infancy in the Netherlands were retrospectively reviewed. Frequency and severity of soiling, constipation, and urinary incontinence were evaluated using questionnaires designed in line with the Krickenbeck classification. Problems during childhood were compared to outcomes at adult age in part of the cohort. Associations between patient- and disease-related factors with complaints beyond childhood were analyzed with the chi-square test or Fisher's exact test, when appropriate. RESULTS: Of 47 included patients (mean age 26.2 years, SD ±6.5), 49% reported at least one defecation or micturition complaint. Urinary incontinence was present in 30% and had a greater negative impact than soiling (24%). Ten patients (21%) reported constipation; five found this severely bothering. Three patients reported social restrictions due to defecation or micturition complaints (6.4%). While sex and tumor histology were not identified as risk factors, a tumor diameter of >10 cm and Altman type I or type II SCT were associated with constipation during adulthood. CONCLUSIONS: One-third of the patients treated for SCT during childhood reported urinary and defecation problems beyond childhood. In only a minority of cases, these led to social restrictions. A greater tumor diameter was associated with a higher risk of constipation during adulthood. Prolonged surveillance strategies are advised for all patients with SCT.

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.