Convalescent phase outpatient parenteral antiinfective therapy for children with complicated appendicitis

BACKGROUND: Children with a perforated or gangrenous appendix become clinically stable after medical and/or surgical therapy but often remain in the hospital solely to complete parenteral antibiotic therapy. This prospective study investigates the outcomes when children who meet specified criteria are discharged to complete parenteral antibiotic therapy at home. METHODS: Children age 1 to 17 years with appendicitis complicated by generalized peritonitis or intraabdominal abscess were eligible to participate. Subjects whose fever was decreasing, who were able to tolerate oral liquids and for whom further parenteral antibiotic therapy was deemed necessary were discharged from the hospital to receive outpatient parenteral antiinfective therapy (OPAT) with meropenem. Therapy was administered by a family member and supervised by home care nurses. Study personnel visited the home daily to collect data on adverse events, compliance and resource utilization. Pa tients served as their own controls in models of reduced hospitalization and net cost savings. RESULTS: Discharged on average on the fourth postoperative day, 87 children received 4.5 +/- 2.1 days of OPAT. Six (7%) children were subsequently readmitted for complications including bowel obstruction (4 children), intraabdominal abscess (1 child) and pleural effusion (1 child). Another child developed a viral syndrome during OPAT. All other patients recovered uneventfully. Six (7%) children discontinued meropenem prematurely because of rash (4 patients) or diarrhea (2 patients). According to models in which each day of OPAT replaced a day of inpatient care, discharge to OPAT reduced hospitalization by 42 +/- 15% and saved a median of $2908 (10th to 90th percentile range, $1,077 to $4,707) per patient. CONCLUSION: Convalescent phase OPAT is a cost-effective alternative to continued hospitalization for children with complicated appendicitis who are clinically stable yet require further parenteral antibiotic therapy.     

Laparoscopic appendectomy is recommended for the treatment of complicated appendicitis in children

Laparoscopic appendectomy in children is well accepted for the treatment of non complicated appendicitis. An increased risk of postoperative intraabdominal abcess formation has been reported in complicated appendicitis. The puropose of this study was to compare open (OA) versus laparoscopic appendectomies (LA) in complicated appendicitis in children and to assess the safety and feasibility of LA. The hospital records of 118 consecutive patients who underwent appendectomy for complicated appendicitis (perforated/gangrenous) from 2000 to 2006 were retrospectively analysed. Fifty-four patients had LA and 64 underwent OA. There were 74 males and 44 females. The length of hospital stay ranged from 4 to 12 days in the LA group and 4 to 17 days in the OA group. Five patients (9.2%) in the LA group had post operative complications; intraabdominal collections in 3 and wound infections in 2. Ten patients (15.6%) had postoperative complications in the OA group; intraabdominal collections in 5, wound infection in 3, pleural effusion in 1 and prolonged ileus in 1. In complicated appendicitis the complication rate is lower for LA as compared to OA. We recommend laparoscopic approach to all children presenting with complicated appendicitis.     

Minimum postoperative antibiotic duration in advanced appendicitis in children: a review

The suitable duration of antibiotic use following appendectomy for advanced appendicitis in children is still debated. A systematic review was performed, including published experimental and observational data of antibiotic use in children who had undergone appendectomy for advanced appendicitis. Data were extracted and analyzed according to predefined criteria. Twenty-eight studies were selected that included 2,284 patients. There was no consistency among the protocols regarding length of antibiotic use, discharge criteria, or use of home antibiotics following discharge. Limiting duration of antibiotic use to 3 days did not appear to be associated with higher rates of intraabdominal abscess or wound infection. In the absence of higher-level evidence, shortening of antibiotic regimens following surgery for pediatric complicated appendicitis appears to be safe.     

The role and value of oral metronidazole in acute appendicitis

A prospective, randomized study was undertaken in 246 patients 4 – 15 years of age with simple or complicated appendicitis and local peritonitis to determine the efficacy of oral metronidazole (OM) threrapy. Those referred on odd days were chosen as the study group (SG) and those on even days as a control group (CG). The SG received OM 10 mg/kg per dose 2 h preoperatively and every 8 h after operation according to the following intraoperative findings: inflamed (mild to severe), 3 doses; gangrenous or perforated with no pus, 3 days, the same with pus, 5 days. The CG received 20 mg/kg cephalexin 2 h before operation and, if the appendix was inflamed, 6-hourly for 3 doses postoperatively. The routine combination in our center of penicillin, chloramphenicol, and gentamicin was given to the patients in the CG with complicated appendicitis, as in the SG, for 3 or 5 days. All cases with generalized peritonitis were excluded from the study. Serum concentrations of metronidazole after one postoperative dose were in the bactericidal range in 18 of 20 patients in whom the measurement was performed. The incidences of wound infection and intraabdominal abscess were quite similar in both groups with the same degree of pathology. However, in patients with complicated appendicitis the hospital stay in the SG was about 1 day less than in the CG. Moreover, hospital costs per patient day were less in the SG. We conclude that OM is a cost-effective drug, more convenient for the patient and nursing staff, and can be used as an effective antibiotic even in complicated appendicitis.     

急性阑尾炎患儿C-反应蛋白水平与病理类型之间的关系及临床意义

目的 探讨C-反应蛋白（CRP）对小儿急性阑尾炎病理类型的判别意义及对手术时机的指导作用.方法 选择我院2010年1月至2014年2月行阑尾切除术并同时检测了白细胞、中性粒细胞比例和CRP的患儿206例,根据术后病理类型分为坏疽性阑尾炎组（53例）和非坏疽性阑尾炎组（153例）,将206例患儿的年龄、性别、白细胞计数、中性粒细胞比例及CRP水平等指标进行Logistic回归分析及ROC分析并绘制ROC曲线.结果 坏疽性阑尾炎组和非坏疽性阑尾炎组患儿的白细胞计数、中性粒细胞比例及CRP水平差异均有统计学意义（P均＜0.05）;Logistic回归分析结果显示CRP水平是判断小儿坏疽性阑尾炎的危险因素（P =0.000,OR=1.071）;ROC曲线显示CRP对判断小儿坏疽性阑尾炎的作用优于中性粒细胞比例和白细胞计数（曲线下面积分别为0.931、0.659、0.599）,其最佳诊断临界值为44.4 mg/L,敏感度75.5％,特异性93.5％.结论 CRP水平有助于判别小儿急性阑尾炎的病理类型,可以作为选择是否手术的一个参考指标.     

Laparoscopic appendectomy is a favorable alternative for complicated appendicitis in children

Laparoscopic appendectomy in children is a generally accepted procedure for the treatment of non-complicated acute appendicitis. Nevertheless, the role of laparoscopy in complicated appendicitis is more controversial. The objective of this study was to examine the safety, efficacy and complications of laparoscopy in children with complicated appendicitis. This is a retrospective review of the children who underwent laparoscopic appendectomy for complicated appendicitis at King Khalid University Hospital, Riyadh, Saudi Arabia between January 1998 and March 2006. Complicated appendicitis includes perforated appendicitis, gangrenous appendicitis and appendicular masses found intra-operatively. Data collected include demographic, duration of symptoms, operative time, analgesia, complications, length of hospitalization and histopathology. Laparoscopic appendectomy was done by three trocar technique in all cases. During the study period, 59 children aged 3–12 years underwent laparoscopic appendectomy for complicated appendicitis. There were 34 patients with perforated appendicitis, 12 patients with gangrenous appendicitis and 13 patients with appendicular mass. The average operating time was 62 min. The average length of hospitalization was 5 days. The post-operative narcotic analgesic requirement was minimal. Laparoscopy was converted to open surgery in two patients (3.38%). These two cases were excluded from further analysis. Four out of 57 patients (7.01%) had post-operative complications. Three patients (5.26%) developed wound infection. One patient (1.75%) developed haematoma at umbilical port site. There was no post-operative intra-abdominal collection. Laparoscopic appendectomy is a safe alternative for the treatment of complicated appendicitis. It does not increase the incidence of complications even with complicated appendicitis. Contrary to the previous studies, we did not have increased incidence of intra-abdominal collection in this review. However, prospective randomized controlled trials are needed to verify these findings.     

小儿急性阑尾炎手术中腹腔冲洗的必要性探讨

目的通过对比各型小儿阑尾炎术中行腹腔冲洗与未行腹腔冲洗的疗效,探讨术中行腹腔冲洗的必要性。方法收集本院近3年内收治的急性阑尾炎病例共350例,其中A组为单纯性阑尾炎,行腹腔镜阑尾切除术;B、C组为化脓性阑尾炎未穿孔,B组行腹腔镜阑尾切除+腹腔引流术,C组行腹腔镜阑尾切除+腹腔冲洗+腹腔引流术;D、E组为坏疽穿孔性阑尾炎,D组行腹腔镜阑尾切除+腹腔引流术,E组行腹腔镜阑尾切除+腹腔冲洗+腹腔引流术。术后对患者资料进行详细统计和相应分析。结果急性单纯性阑尾炎行腹腔镜阑尾切除术后患儿预后良好。急性化脓性阑尾炎组术中行腹腔冲洗后,术后患儿肛门排气排便时间、直肠刺激症状、间断腹痛情况明显增加,且术后腹腔脓肿的发生率明显增多,术后5 d血常规白细胞稍高,1例并发右侧膈下脓肿,平均住院时间较未冲洗组明显延长;相反,急性坏疽穿孔性阑尾炎组,术中行腹腔冲洗后,患儿术后舡门排气排便时间缩短,术后腹腔残余感染、直肠刺激症状、间断腹痛情况降低,术后腹腔脓肿等并发症的发生率降低,术后5 d血白细胞较未冲洗组稍低。术后患儿恢复相对较快,住院时间短。结论小儿急性阑尾炎术中冲洗治疗应根据具体情况选择合适的方法,术中调节体位,充分显露脓腔,引流彻底,引流管位置适宜;急性化脓性阑尾炎未穿孔者不需行腹腔冲洗,而急性坏疽穿孔性阑尾炎则需术中行腹腔冲洗。     

Is it justified to obtain routine peritoneal fluid cultures during appendectomy in children?

Controversy exists regarding obtaining routine peritoneal cultures during appendectomy. The aim of the study was to determine the impact of obtaining routine peritoneal fluid cultures during appendectomy on the treatment and clinical outcome in children. The charts of 269 children who were operated with the diagnosis of appendicitis between January 1996 and January 2001 were reviewed. The microorganisms in peritoneal cultures, selection of antibiotics and clinical outcome were evaluated. Average age was 10.1+/-3.3 (range, 1 to 17 years) years with a male to female ratio of 1.7 (170/99). There were two groups of patients; Group 1: uncomplicated appendicitis (201/269=75%), and Group 2: complicated (perforated) appendicitis (49/269=18%). In the series, 19 patients were found to have a normal appendix in histopathological examination (7%). Cultures were obtained from 95 (35.3%) patients (group 1: 59/95, group 2: 36/95). In patients with uncomplicated appendicitis, 6.7% of the cultures (4/59) were positive while in group 2, the rate was 47.2% (17/36) ( p<0.05). Only in four patients who were in group 2, antibiotics were re-adjusted according to the cultures. Escherichia coli and Klebsiella pneumoniae were the most common microorganisms. There were no complications in group 1, while wound infection (18.3%) and intra-abdominal abscess (2%) were the two most common complications in group 2. Intra-operative peritoneal cultures during appendectomy do not add much to the treatment of children. Therefore, it is not necessary to get peritoneal swab cultures during the procedures, and empiric use of wide spectrum antibiotics when necessary is generally sufficient in the management of this group of children.     

Determinants of postoperative abscess occurrence and percutaneous drainage in children with perforated appendicitis

Purpose

Postoperative abscesses after perforated appendicitis have no clear risk factors or indications for percutaneous drainage. Our study addressed these two issues.

Methods

A logistic regression model was used to delineate risk factors for postoperative abscess in children with perforated appendicitis treated during a recent 5-year period. Drainage of abscess was compared to antibiotic treatment.

Results

Postoperative abscess occurred in 42 (14.8 %) of 284 patients. Higher WBC count, presence of bowel obstruction at presentation, diffuse peritonitis with a dominant abscess at surgery, and one specific surgeon were significantly associated with postoperative abscess, while fever or pain requiring narcotics at the time of abscess diagnosis was significantly associated with drainage. Compared to non-drainage, those drained had longer hospital stay including readmissions (15.9 ± 5.3 vs. 12.2 ± 4.6 days, p < 0.005) and less readmissions (9.5 vs. 33.3 %, p = 0.06). Over the 5-year period, there was no increased trend in abscess occurrence (p = 0.56), but there was an increased trend in the use of percutaneous drainage (p = 0.02).

Conclusions

The risk of a postoperative abscess can be predicted by specific clinical characteristics, surgical findings, and treatment-related factors. Percutaneous drainage was associated with longer hospital stays, but less readmissions.     

Perforated appendicitis in children: to drain or not to drain?

We studied 66 children with perforated appendicitis at the University of New Mexico to determine whether or not transperitoneal drainage has any advantage in the management of these children. Patients were assigned to one or the other treatment group on the basis of the call schedule of the attending surgeons, two of whom preferred drainage and two of whom did not. Other aspects of appendicitis management (e. g., supportive care, antibiotics) were the same for both groups. Thirty-two other children who had an abscess at the time of appendectomy were excluded from the analysis. The two study groups were similar in age and severity of illness. Postoperative complications (wound infection, abdominal abscess, small-bowel obstruction) had a similar incidence in the two groups: 6/32 (18.8%) for the drained group and 7/34 (20.6%) for the undrained group. The hospital stay was significantly longer for the drained group (mean 10.1 days, median 9 days) versus the undrained group (mean 7.0 days, median 7 days). The power of our study was 0.52; twice our sample size would have been required to achieve a power of 0.80. The evidence suggests that, unless an abscess is present, drainage may be abandoned for children with perforated appendicitis.     

Acute appendicitis presenting as thigh abscess in a child: a case report

A case of retrocecal appendicitis is described in a 6-year-old male child who presented with thigh abscess. The presence of a positive psoas stretch test, feculent discharge, an enteric growth on bacteriological examination, and intraabdominal fluid collection on abdominal ultrasound provided clues to the presence of an intraabdominal source of sepsis. Laparotomy revealed a perforated retrocecal appendix with surrounding collection communicating into the thigh. Appendectomy with drainage of retroperitoneal and thigh collections under adequate antibiotic coverage resulted in a satisfactory recovery. We describe our experience with the present case and discuss the pertinent literature.     

Creating diagnostic criteria for perforated appendicitis using cross-sectional imaging

Introduction

Preoperative determination of perforated versus acute appendicitis can be difficult. We compared CT and MRI performance in diagnosing perforated appendicitis, and created diagnostic criteria.

Methods

We retrospectively reviewed all pediatric patients who underwent appendectomy within one day of CT or MRI between 1/1/2013 and 1/16/2016. True diagnosis was determined by pathology report. Findings on CT/MRI were grouped into “hard” findings (abscess, pneumoperitoneum, extruded fecalith, appendiceal wall with visible hole) and “soft” findings (extensive/diffuse inflammation/free fluid, phlegmon). Correlation of white blood cell count (WBC), temperature, peritoneal signs, and symptom duration >72 h with perforation was assessed using logistic regression. Significant correlates were incorporated in clinical criteria.

Results

135 patients underwent appendectomy after CT/MRI. Fifty patients underwent MRI and 85 CT. Using hard and/or soft findings, MRI was 86.7% sensitive and 74.3% specific, compared to 68.4% (p = 0.19) and 92.4% (p = 0.025) for CT. WBC > 15, temperature >38.0 °C, and peritoneal signs predicted perforation. Diagnostic accuracy of MRI was highest using imaging findings alone. Accuracy of CT was improved by mandating at least one of the previous three clinical correlates, resulting in 68.4% sensitivity and 93.9% specificity.

Conclusions

MRI trended toward more sensitive and CT was more specific for complicated appendicitis. CT specificity is improved by our algorithm.

     

Appendiceal perforation in children diagnosed in a pediatric emergency department

OBJECTIVE: To determine the incidence of appendiceal perforation (AP) among children with acute appendicitis (AA) and determine factors associated with AP. DESIGN: Retrospective chart review. SETTING: Emergency department (ED) of Primary Children's Medical Center (PCMC). PATIENTS: 131 children less than 17 years of age with AA diagnosed in the PCMC ED. RESULTS: The overall rate of AP was 47%. One hundred eleven (85%) children with AA were correctly diagnosed on their first ED visit. Patients with AP had a significantly (P < 0.05) lower median age (8.0 vs 11.0 years), longer duration of illness (3.0 vs 1.4 days), greater incidence of vomiting and fever by history (91% vs 69% and 83% vs 58%, respectively), higher median temperatures (39.0 degrees vs 38.3 degrees C), and higher proportions of leukocyte (WBC) band forms (14% vs 5%). Patients with AP did not differ from those without AP with respect to total WBC count, hour of arrival, or number of ED visits. CONCLUSIONS: The rate of AP among pediatric patients with AA is greater among younger children and is associated with vomiting, prolonged illness, and higher body temperatures. Unexpectedly, patients with AP did not have higher total WBC values, more frequent late night arrivals, a longer time interval prior to surgery, or more ED visits prior to diagnosis. These findings suggest that efforts to decrease the rate of AP should be directed toward heightening awareness among primary care physicians regarding the high rate of AP in children, with an emphasis on early ED and surgical referral.     

Acute appendicitis in childhood: experience in a developing country

Appendicitis is a common cause of acute abdominal pain in childhood. Four hundred and thirty-six children 15 years of age and younger with histologically proven acute appendicitis were treated surgically over an 11-year period (1983–1993). Epidemiological differences suggested a lower prevalence in the black African and mixed ethnic groups in comparison to Caucasian children. There was no evidence suggesting that appendicitis was an emerging disease in the period under study. Appendicitis occurred at any age, but only 24% of cases presented in the first 8 years of life, the peak incidence being from 11 years onwards. There were 3 neonates in this series who presented in a similar fashion to necrotising enterocolitis. One of these was shown to have Hirschsprung's disease at post-mortem examination. There were no striking differences in the clinical presentation between groups, but a higher incidence of complicated appendicitis was identified in the younger age group and those from poor socioeconomic situations. The male:female ratio was 1.74 overall. A male preponderance was also identified in patients presenting pre- and post-puberty. Seasonal variation was present, with the highest incidence being in the summer months. Intestinal helminths coexisted in 9.4% of cases; the majority were ova of Ascaris lumbricoides. A low incidence of faecoliths was recognised. Clinicopathological correlation showed an incidence of 41% (177 patients) with acute appendicitis, 47% (203) with perforated appendicitis, 4% (20) with a walled-off appendix abscess, and 7% (32) with gangrenous appendicitis. The remaining 1% showed chronic inflammatory changes. A mortality of 0.4% (2 patients) resulted from complications attributable to late diagnosis, generalised peritonitis, and septicaemia.     

Appendicitis in the young child: a continuing diagnostic challenge

OBJECTIVE: The purpose of this review was to examine the presenting signs and symptoms of children 5 years of age or less who underwent operation for appendicitis. In addition, we sought to determine the rate of perforation of the appendix and the effect on outcome in this age group. METHODS: Medical records for the period September 1987 to September 1998 were reviewed for all children 5 years of age or less who underwent appendectomy for appendicitis. Data gathered included age at operation, gender, care sought prior to admission for appendectomy, duration of symptoms, signs and symptoms at the time of admission, and length of postoperative hospital stay. Symptoms of diarrhea, emesis, fever, pain, and anorexia were recorded. Physical signs of an abdominal mass, guarding, rebound tenderness, rigidity, and diffuse or focal tenderness were recorded. Diagnostic information included white blood cell count with differential, and radiographic imaging, if obtained. The presence or absence of perforation of the appendix, and abscess formation were based on the intraoperative impression of the operating surgeon. RESULTS: For the 11-year period, 120 patients 5 years of age or less required an operation for appendicitis and had a complete medical database. The mean age was 3.6 +/- 1.3 years; 53% were male. Patients underwent a separate medical evaluation prior to arriving at a definitive diagnosis in 44.2 % cases. The most common presenting symptom was abdominal pain (94%); the most common sign was abdominal tenderness (95.8%). Tenderness was generally diffuse if perforation had occurred (62%) or focal in the nonperforated group (61%). The duration of symptoms in patients with perforation was more than double that of the nonperforated patients (4.7 vs 2.1 days, respectively). The mean white blood cell count (WBC) was 18.3 +/- 7.4 cells/mm3, and did not differ significantly between the perforated and nonperforated groups. A left shift detected in the WBC differential was present in 91%. An abdominal radiograph was obtained in 87%, and demonstrated a fecalith in 18%. A preoperative ultrasound was obtained in 38%, a computed tomographic scan in 7%. At the time of surgery, 74% were found to have evidence of perforation. An abscess was found at the initial surgery in 47% of patients with appendiceal perforation, but in no patient in whom perforation had not occurred. The rate of perforation increased as the age of the patient decreased (100% perforation for age 1 (n = 10) to 69% for age 5, (n = 35). Perforation was associated with a longer hospital length of stay as compared to the nonperforated appendix (median 9 days vs. 3 days, respectively, P < 0.001). There were no deaths in this series. CONCLUSION: Appendiceal perforation continues to be a common occurrence in the young child and increases in frequency as the age of the patient decreases and the duration of symptoms lengthens. Perforation results in a significant increase in hospital length of stay and rate of abscess formation.     

儿童阑尾周围脓肿腹腔镜Ⅰ期手术疗效分析

目的:探讨运用腹腔镜Ⅰ期阑尾切除术治疗儿童阑尾周围脓肿的临床疗效。方法:收集2017年5月至2020年4月在福建医科大学附属漳州市医院接受腹腔镜Ⅰ期阑尾切除术治疗的269例儿童复杂性阑尾炎患儿的相关资料。其中,男181例,女88例;将45例儿童阑尾周围脓肿患儿作为A组,224例同期收治的其他复杂阑尾炎(化脓性、坏疽性或...     

Interval appendectomy in perforated appendicitis

The treatment of the perforated appendix remains controversial, with the optimal timing of surgical intervention unclear. Previous studies have documented an increase in both minor and major complication rates in patients undergoing appendectomy for perforated appendicitis. We sought to evaluate the nonoperative therapy of perforated appendicitis followed by interval appendectomy. The charts of all children undergoing admission for appendicitis during a 10-year period (n = 480) were reviewed. Data were abstracted regarding patient presentation, laboratory and radiologic findings, operative and pathology reports, and postoperative course in those patients with perforated appendicitis (n = 104). Comparisons were made between patients undergoing primary appendectomy for perforated appendicitis (n = 87) and those treated with IV antibiotics and hydration and then scheduled for interval appendectomy 4 to 6 weeks following the acute event (n = 17). Treatment assignment was determined by the attending pediatric surgeon in a non-randomized fashion. No significant differences were seen between these two groups in days of antibiotic treatment, nasogastric decompression, and IV hydration. Additionally, total hospital days and cost did not differ significantly between the two groups (primary = 10.3 days and $10,550; interval = 13.3 days and $13,221, P = 0.11 and 0.21, respectively). The overall complication rates, 12.6% in the primary group and 5.9% in the interval group, also did not differ significantly, while the major complication rate (wound dehiscence, abscess, and small-bowel obstruction), 10% versus 0%, was significantly higher in the primary group as compared with the interval group. Our data demonstrate no significant disadvantage, and possibly an improvement in the major complication rate, with nonoperative treatment of perforated appendicitis followed by interval appendectomy. We suggest that this treatment modality should be considered when evaluating the child with perforated appendicitis.Presented at the Surgical Section, American Academy of Pediatrics, Washington, DC, USA, 30 October–4 November 1993     

Scrotal abscess following appendectomy

Postoperative infectious complications in children following perforated appendicitis present in diverse ways. We present two unusual complications of appendectomy for perforated appendicitis: an acute scrotum after open and laparoscopic appendectomy. A␣retrospective review of two cases of scrotal abscess following appendectomy at our hospital as well as a MEDLINE search was performed to review the clinical presentation, etiology, type of treatment, and outcome of these patients. Although scrotal inflammation occurring postoperatively in a patient with perforated appendicitis may be due to an incarcerated hernia, it is much more likely to be due to a scrotal abscess. Patients without a patent processus vaginalis or inguinal hernia at initial presentation of peritonitis must be carefully followed in the postoperative period and explored early if testicular or scrotal pain becomes manifest. Accepted: 2 August 2000     

A novel and simple machine learning algorithm for preoperative diagnosis of acute appendicitis in children

There is a tendency toward nonoperative management of appendicitis resulting in an increasing need for preoperative diagnosis and classification. For medical purposes, simple conceptual decision-making models that can learn are widely used. Decision trees are reliable and effective techniques which provide high classification accuracy. We tested if we could detect appendicitis and differentiate uncomplicated from complicated cases using machine learning algorithms. We analyzed all cases admitted between 2010 and 2016 that fell into the following categories: healthy controls (Group 1); sham controls (Group 2); sham disease (Group 3), and acute abdomen (Group 4). The latter group was further divided into four groups: false laparotomy; uncomplicated appendicitis; complicated appendicitis without abscess, and complicated appendicitis with abscess. Patients with comorbidities and whose complete blood count and/or pathology results were lacking were excluded. Data were collected for demographics, preoperative blood analysis, and postoperative diagnosis. Various machine learning algorithms were applied to detect appendicitis patients. There were 7244 patients with a mean age of 6.84 ± 5.31 years, of whom 82.3% (5960/7244) were male. Most algorithms tested, especially linear methods, provided similar performance measures. We preferred the decision tree model due to its easier interpretability. With this algorithm, we detected appendicitis patients with 93.97% area under the curve (AUC), 94.69% accuracy, 93.55% sensitivity, and 96.55% specificity, and uncomplicated appendicitis with 79.47% AUC, 70.83% accuracy, 66.81% sensitivity, and 81.88% specificity. Machine learning is a novel approach to prevent unnecessary operations and decrease the burden of appendicitis both for patients and health systems. III.     

The ectopic appendicolith from perforated appendicitis as a cause of tubo-ovarian abscess

Acute appendicitis is a common surgical cause of abdominal pain in the pediatric population. History and physical examination are atypical in up to a third of patients. Known potential complications of untreated or delayed management of acute appendicitis include appendiceal perforation, periappendiceal abscess formation, peritonitis, bowel obstruction and rarely septic thrombosis of mesenteric vessels. We report an unusual complication of perforated appendicitis. A tubo-ovarian abscess developed secondary to appendicolith migration into the right fallopian tube in a patient who had undergone interval laparoscopic appendectomy for perforated appendicitis. The retained appendicolith was visualized within the obstructed and dilated fallopian tube on contrast-enhanced CT. We discuss the CT imaging features of this unusual complication of perforated appendicitis.