Pitfalls in the histological diagnosis of total colonic aganglionosis on appendicectomy specimens

Background: Hirschsprung’s disease is the most important cause of functional intestinal obstruction in children. It is characterized by the absence of ganglion cells in the submucosal and myenteric plexuses on histology. In 10% of Hirschsprungs disease patients, involvement of the entire colon is seen in a condition called total colonic aganglionosis (TCA). The absence of ganglion cells in the appendix on histology has been considered diagnostic of TCA. The validity of this histological finding being taken as criteria for diagnosis is not clear. Aims and Objectives: This study examines the presence and the number of myenteric and submucosal ganglion cells in the appendices of suspected cases of TCA and compares these findings with controls, specimens of acute appendicitis, and histologically normal appendix in pediatric cases. Materials and Methods: Thirty-six appendix specimens of suspected TCA cases and controls, that is, ten each of acute appendicitis and histologically normal appendix in pediatric age group were included in this study taken up in the pathology department of a tertiary pediatric referral hospital. The presence or absence and the number of ganglion cells in each specimen was semiquantitatively evaluated in a blinded manner. These findings were descriptively compared and analyzed. The difficulties faced by the pathologist in reporting the pediatric appendix specimens were also documented. Results: The cases and controls showed that aganglionosis and no significant difference were noted in the number of ganglion cells per high power field between the cases and controls. The reporting pathologists enumerated quite a few pitfalls and problems encountered by them in the process of interpreting ganglion cell status of pediatric, particularly neonatal appendicectomy specimens. Conclusion: Aganglionosis of the appendix on histology may not be an ideal tool for the diagnosis of TCA. Difficulties in histological characterization of ganglion cells, technical errors in tissue embedding and the presence aganglionic skip areas might cause errors in the interpretation of ganglion cell status of appendix specimens, particularly infants, and neonates.

Omental cyst: a case report and review of the literature

Background Omental cysts are rare, predominantly occur in children, and often initially present with symptoms masquerading as other more common intra-abdominal pathologies. In this case report, we present the case of a child with an omental cyst that originated from the lesser sac. Due to the location of this cyst, resection presented unique technical challenges that have not been described in existing literature. Case presentation A 4-year-old male patient presented with symptoms initially concerning for appendicitis. Ultrasound showed a normal appendix but a large volume of complex intraperitoneal fluid. Computed tomography subsequently demonstrated a large cystic structure spanning from the stomach to the bladder. The patient was taken to the operating room where a large omental cyst was found to originate from the lesser sac. The resection was difficult due to the thin wall of the cyst and the intimate association of the superior-most aspect of the cyst with the tail of the pancreas, but was ultimately successful. Conclusions Omental cysts are rarely suspected before detection on abdominal imaging. Surgical resection is the treatment of choice, and complete resection can result in a recurrence-free postoperative course. Laparoscopic resection has been reported, but laparotomy is reasonable when a minimally invasive approach may not allow for a safe resection without rupture of the cyst. Anatomical characteristics of the cyst, as demonstrated in our case, can present challenges in the treatment of this otherwise benign entity.

TP9.2.5Routine ultrasound in paediatric appendicitis is highly accurate and substantially reduces negative appendicectomy rate

Aims Our centre routinely uses ultrasound in adults to confirm diagnosis of appendicitis. This study investigated its use in the diagnosis of suspected appendicitis in children and its impact on management. Methods Retrospective cohort study of children (5-16 years) managed by general surgeons with suspected appendicitis during 2019. Primary outcomes were ultrasound use. Secondary outcomes were diagnosis, length of stay, complications and negative appendicectomy rate. Results A total of 193 children were admitted with suspected appendicitis. The majority underwent an ultrasound scan (169/193 [88%]) which identified an inflammed appendix or secondary-inflammation in nearly all cases of appendicitis (65/71 [91%] and 5/71 [7%] respectively). A normal appendix was identified in more than half of children not diagnosed with appendicitis (53/95 [56%]), with the rest showing an ovarian pathology (3/95 [3%]) or normal scan (39/95 [41%]). Ultrasound had high sensitivity (92% [CI 83-97%]) and specificity (100% [CI 96-100%]) for appendicitis. The majority of children diagnosed with appendicitis were treated with laparoscopic appendicectomy (75/85 [88%]) and a minority medically-managed (10/75 [12%]). One appendix mass was medically-managed, and two Meckels Diverticulitis underwent a laparoscopic small bowel resection. Negative appendicectomy rate was extremely low (2/77 [2.5%]). Post-operative complication rate was low (6%). Median length of stay was short for appendicitis and all other diagnoses (2days [IQR 2.2] and 1day [IQR 0] respectively). Discussion The majority of children with suspected appendicitis underwent pre-operative ultrasound, which was highly sensitive and specific for appendicitis. Negative appendicectomy rate was extremely low, and likely related to routine pre-operative imaging.

EP.FRI.580 Negative appendectomy rates at a district regional hospital

Aim Emergency appendectomy is one of the most common emergency procedures done. Negative appendectomy rates vary and the aim was to identify the rate of it at a DGH. Method Appendectomy cases at a small regional hospital were during a 2-year period (2017-2018) were included. Elective and interval appendectomies were excluded. Histopathology findings were noted. Results 78 patient had an emergency appendectomy, of which 87% (n = 68) had it done laparoscopically. Normal appendix on pathology was found in 13.8% (n = 12) of the removed appendices. They were all removed laprascopically. The majority were females (n = 11) compared to males (n = 1). 58% of the normal appendix (n = 7) were identified as a macroscopically normal appendix. 36% of the females were mid-cycle (n = 4). The mean WBC on admission was 9.5 (4.8-13.6 x109/L) . All of the females had a transabdominal USS as initial investigation but was inconclusive. Conclusion Negative appendectomy rates are still high in female patients, whether doing further scans such as TVUSS or CTAP might reduce the risks of getting a negative appendectomy, needs to be discussed and tailored to each case, as the majority are young patients in the reproductive age group.

EP.FRI.241 Negative appendicectomy rate and role of biomarkers in predicting the severity of acute appendicitis

Aim Acute appendicitis is the most common general surgical emergency. A recent consensus study has proposed a 10% negative appendicectomy rate. We aimed to determine the negative appendicectomy rate in our centre whilst evaluating the role of biomarkers in predicting the severity of appendicitis. Methods A single-centre retrospective analysis of consecutive laparoscopic appendicectomies from 2019-2020 was performed. Patients were categorised by severity using AAST grading system. Kruskal-Wallis test was used to compare biomarkers levels (WCC, CRP, bilirubin, neutrophil:lymphocyte ratio (NLR) and platelet:lymphocyte ratio (PLR)). T-test, ROC curve and Fisher’s exact test were used to differentiate between perforated and non-perforated appendicitis and negative appendicectomy rate. WCC ≥11, CRP ≥50, bilirubin ≥21, NLR ≥6.4 and PLR ≥153 were the cut-off values. Negative appendicitis was defined as normal appendix at histopathological analysis. Results 224 patients were included; mean age 33.7 years, 57.1% were male. 17 patients (7.6%) had negative appendicectomy. CRP, NLR, bilirubin and PLR increase with AAST score (P < 0.001). WCC ≥11 (p < 0.001) and NLR ≥6.4 (p = 0.007) predicted acute appendicitis. WCC (p = 0.018), CRP (p < 0.001), bilirubin (p < 0.001), NLR (p < 0.001), PLR (p = 0.002) were predictive for appendiceal perforation. Conclusion 7.6% negative appendicectomy rate in our centre is below the recommended standard of 10% and lower than other centres. In our centre, raised WCC and NLR were predictive of acute appendicitis. WCC, CRP, bilirubin, NLR and PLR may be used to distinguish between perforated and non-perforated appendicitis. Our results add to the conflicting body of evidence relating to biomarkers and the severity of appendicitis.

A comparison of intra-operative diagnosis to histopathological diagnosis of acute appendicitis in paediatric and adult cohorts: an analysis of over 1000 patients

Background Appendicitis is a common general surgical emergency. The role of removing a normal appendix is debated. However, this relies on accurate intra-operative diagnosis of a normal appendix by the operating surgeon. This study aimed to compare surgeon’s intra-operative assessment to final histological result acute appendicitis in paediatric and adult patients. Methods All patients who underwent appendicectomy over a 14-year period in a general surgical department were identified using the prospective Lothian Surgical Audit system and pathology reports retrieved to identify final histological diagnosis. Open appendicectomy was selected to examine, as the routine practise at our institution is to remove a normal appendix at open appendicectomy. Results A total of 1035 open appendicectomies were performed for clinically suspected appendicitis. Sensitivity of intra-operative diagnosis of appendicitis with operating surgeon was high at 95.13% with no difference between trainee and consultant surgeon or between adult and paediatric cases. Specificity of intra-operative diagnosis was lower in the paediatric group (32.58%) than in the adult group (40.58%). Women had a higher rate of negative appendicectomy than men. Conclusion The results of this study highlight some discordance between histological evidence of acute appendicitis and intra-operative impression. Therefore other clinical variables and not just macroscopic appearance alone should be used when deciding to perform appendicectomy.

893 Consenting for Appendicectomy

Appendicitis denotes to the inflammation of the appendix with over 50,000 cases in the UK per year. The treatment of choice is appendicectomy and this is one of the most common operations in the UK. There are nil NICE or King’s College Hospital (KCH) guidance available on consenting for appendicectomy. Thus, guidance from Guy’s and St Thomas’ and Whittingham Health was used as reference and the consent forms at KCH were analysed for all appendicectomies over 2 months. A retrospective observational audit (Cycle 1) was conducted between Dec 2018 – Jan 2019 consisting of 34 patients. It assessed whether common complications were documented clearly and any possible complications. This audit identified that consenting for diagnostic laparoscopy/appendicectomy did not cover many serious complications and was overall inadequate. One of the most common and serious complications was ileus/SBO (occurred in 9%) and was not consented for in 88% of patients. 12% of patients had a normal appendix and this was not consented in 100% of these patients. Later, posters and teaching sessions were created to optimise the consent process for appendicectomy. This was re-audited (Cycle 2) again between June 2019 – July 2019 with 49 patients to identify whether a positive change was identified. It identified that an 12% increase in consenting for ileus/SBO, 10% increase in conversion to open and 47% of individuals started consenting for hernia repair. This work is vital as inadequate consenting can destroy doctor-patient relationship and result in litigation and we encourage clear consenting guideline for appendicectomies across trusts.

344 Managing Clinical Rarities: A Unique Case of Non-Inflamed Appendix in A Port Site Hernia

Introduction Port site hernias containing the appendix are sporadically described in the literature, with most cases presenting with acute appendicitis. Cases of a normal appendix being found in such hernias are extremely rare and rarely published. Here we describe a patient with a port site hernia containing a non-inflamed appendix. The lack of similar recorded cases makes this a unique case to highlight and discuss. Case Description 81-year-old lady, with adenocarcinoma of the upper rectum, underwent a laparoscopic high anterior resection in late 2018. With 12 mm ports placed in Umbilicus and RIF. 5mm ports placed in RUQ and LUQ. The 12 mm ports were closed with deep suture closure and the skin was closed using clips. Computerised tomography (CT) imaging at one year showed local cancer recurrence and a small abdominal wall hernia in the right iliac fossa. During subsequent resection surgery, a RIF port site hernia was identified intraoperatively. The hernia sac consisted of an uninflamed appendix. The hernia was reduced and an appendicectomy was performed with the hernia being closed with interrupted suture closure. Histology of the appendix confirmed no evidence of inflammation. Discussion When a clinical rarity is encountered there is often minimal literature to guide management and decisions must be made based on surgical principles and clinical reasoning. Although here an appendicectomy was performed, resection of a normal appendix remains a contentious point in the surgical field. This case demonstrates a potential management option to guide surgeons who encounter this clinical rarity in their future practice.

651 An Audit of Negative Appendectomy Rate at A District General Hospital in the UK

Aim There is significant variation in management of acute appendicitis across the UK. Despite advancements in imaging modalities, acute appendicitis is still a clinical diagnosis. The primary aim of this study was to determine the negative appendectomy rate (NAR) and secondary aim was to look for the imaging results and hospital readmission rate in case of a normal appendix. Method It is a retrospective analysis of all the patients admitted with a suspicion of acute appendicitis from Jan 2018 to April 2019. For data collection hospital medical record was used. Information about patient demographic details, blood results, outcome, operative findings, and histology of appendix if removed, was collected. For Patients having negative appendectomy, hospital admission rate was calculated. Results Total 517 patients were admitted with suspected acute appendicitis and only 45.6% (n = 236) patients underwent surgery. Females=52.1%, Males 47.9%. Mean age was 31 years. NAR was 10.6% (n = 25). (Females= 9.3%, Males=1.3%), 8.4% female patients were below 35 years of age. Patients were divided into 3 groups (Normal appendix NA, Uncomplicated appendicitis UA, complicated appendicitis CA). There was a statistically significant difference in inflammatory markers between the groups. In NA group 17/25 patients underwent prior imaging and imaging suggested acute appendicitis in 7/17 patients. Post NA hospital readmission rate was 20%, all of them were females, and gynecology opinion was sought in all of them. Conclusions The negative appendectomy rate is at 10.6%, comparable to national database. It is more common in young females due to a range of differential diagnoses.

The etiology of appendicitis. Reindorf (Mitt. aus. d. Grenz. D. Med. u. Chir., Bd. 34)

The author holds the view that the normal appendix does not fall ill with the disease that we are accustomed to call appendicitis. The main cause of this disease is secondary infection of the primary worms, namely pinworms, defects in the epithelium and mucous membrane.