Management Of Appendicitis Research Articles

8 Comparison of One-year Outcomes by Management Type in Patients Presenting to the Emergency Department With Uncomplicated Acute Appendicitis

There are approximately 300,000 cases of acute appendicitis in the US annually. Laparoscopic appendectomy is currently the most widely preferred method for acute appendicitis. However, non-operative management for appendicitis has been cited as a viable alternative to appendectomy. Our objective was to compare ED patients with uncomplicated acute appendicitis who received appendectomy versus no surgery for one-year outcomes including surgery rates, ED revisits, repeat hospitalizations, and cost.

Diagnosis and Management of Chronic Appendicitis in Children: A Case Report

Background: Abdominal pain was one of the most complaints in children. Chronic appendicitis was the common cause of recurrent abdominal pain. The incidence of this case was 1,5% of all appendicitis cases. The manifestation was not specific, and one of the treatment options was surgical with laparotomy or laparoscopy methods.
 Case presentation: A 10-year-old boy came to the outpatient clinic of gastroenterohepatology with a diagnosis of abdominal pain caused by chronic appendicitis differential diagnosis of chronic gastritis with abdominal pain, especially the pit of the stomach moving to the right waist since 3 months ago. Physical examination of the patient showed the general condition was moderate, conscious, and normal vital signs. Abdominal distension was absent, tenderness in the lower right abdomen was present, and the pain was present in the lower right abdomen. There was contralateral tenderness in the left lower abdomen. An appendicogram examination shows chronic appendicitis. The patient was consulted for pediatric surgery for appendectomy and later controlled to a surgical outpatient clinic after discharge.
 Conclusion: Chronic appendicitis usually shows unspecific manifestation and physical examination. Early diagnosis and surgical treatment are options to treat appendicitis in children.

Incidental Appendiceal Tumors During Appendectomy: A Nineteen-Year Retrospective Review at a Municipal Hospital.

Non-operative management of appendicitis (NOMA) has recently gained popularity, but a concern is that NOMA might miss appendiceal neoplasms. We conducted a retrospective review of 1694 appendectomies done for acute appendicitis at our institution between January 2001 and December 2019 to study the incidence and distribution of appendiceal tumors. We identified 24 appendiceal neoplasms (1.43%), including 9 Low Grade Appendiceal Mucinous Neoplasms (LAMNs), 6 neuroendocrine tumors (NETs), 6 mucoceles, and one each of adenocarcinoma, endometrioma, and neurofibroma. Tumor occurrence had two age peaks, with LAMNs prominent in the 5th and 6th decades of life and NETs in the 2nd and 3rd decades. All patients under age 40 had benign disease. Presence of appendicoliths was independent of the presence of neoplasms. All cases were managed per National Comprehensive Cancer Network (NCCN) guidelines, with twenty cases cured by appendectomy alone. Given these, we conclude that NOMA is safe for patients under 40.

Identifying Recurrence Risk Factors in CT-Confirmed Acute Appendicitis in Adults Managed Non-operatively During the COVID-19 Pandemic.

Background/Objective: Acute appendicitis (AA) is predominantly managed with appendectomy, but can be treated non-operatively, leading to a high risk of recurrence. Non-operative management has been more common since the COVID-19 pandemic affected the feasibility of performing surgery. This case-control study analyzed non-operatively managed patients in order to identify clinical and radiological factors associated with recurrence risk. Methods: Over 12 months, 48 adults with CT-proven AA managed non-operatively were identified, and followed up for at least six further months to assess them for recurrence (readmission to hospital more than 14 days after discharge and after symptom resolution, requiring treatment for appendicitis). Clinical and CT data were collected and a Cox regression survival analysis was performed to produce hazards ratios (HRs).Results: Of the 48 patients, 12 (25%) experienced a recurrence up until the end of the follow-up period, eight of whom were then treated operatively, and four treated non-operatively. On the univariate analysis, greater recurrence risk was observed in patients with diabetes mellitus, higher heart rate (on admission and maximum value during admission), lower white cell count and neutrophils and appendiceal wall thinning on CT. On the multivariate analysis, diabetes mellitus (HR=7.72, p=0.021) and higher heart rate (HR=1.08, p=0.018) were associated with statistically significant greater recurrence risk.Conclusions: Diabetes mellitus and higher heart rate on admission are associated with greater recurrence risk of AA managed non-operatively. No CT findings were associated with statistically significant greater risk. Clinicians should, therefore, consider DM and heart rate when making decisions on appendicitis management, especially during the COVID-19 pandemic but also beyond it.

Infantile appendicitis: Importance of diagnostic accuracy and a lowered threshold for computed tomography

Appendicitis in the infant population is rare and often misdiagnosed. It can be associated with perforation and sepsis and necessitates expedient identification when present in a sick infant. We describe a case of perforated appendicitis in a 10-month-old infant after diagnostic workup ruled out common causes of colicky abdominal pain. We highlight documented recommendations for workup and management of neonatal and infantile appendicitis. We show that the consensus in literature is prompt diagnosis and surgical intervention for the best chance at preventing morbid outcomes that increase mortality.

Homoeopathic Management of Sub-acute Appendicitis—A Case Report

AbstractSub-acute appendicitis is a condition where some episodes of acute appendicitis apparently subside spontaneously before they reach the acute stage. A 29-year-old man presented with pain in the right iliac fossa for the last 1 week with periumbilical radiation of pain associated with continual nausea, occasional bouts of vomiting, chill and rigours. Computed tomography scan report suggested a case of sub-acute appendicitis. On the basis of presenting features, the patient was treated with Belladonna and Calcarea carbonica in 30c and 200c (centesimal) potencies, respectively, with repetitions. The patient was under treatment for nearly 6 months with favourable improvement of the generalities along with the underlying pathology. The case was indicative of further studies with adequate sample size in such pathological condition to come to any decisive conclusion.

CT scans do not reliably identify appendicoliths in acute appendicitis

• Pre-operative identification of appendicoliths on CT was compared to appendicoliths in pathology specimens. • PPV, NPV, Sensitivity, and Specificity for pre-operative CT identification of appendicoliths were calculated. • CT scans do not reliably identify appendicoliths in acute appendicitis. • CT identification of appendicoliths is too unreliable to decide between surgery and antibiotics for appendicitis. Both the CODA trial and the 2020 WSES Jerusalem guidelines concluded that nonoperative management of appendicitis (NOMA) was non-inferior for uncomplicated appendicitis but appendicoliths increase risk for complications. Thus “Appendicoliths on CT” are a relative contraindication to NOMA but accuracy of CT in identifying appendicoliths is just assumed. We conducted an EMR review of 1552 appendectomy patients, who had pre-operative CT scans for suspected acute appendicitis from 2001-2019. Two radiologists reinterpreted images from 2011 and 2019 for presence of appendicoliths. Appendicoliths identified on CT were compared to appendicoliths in corresponding pathology specimens. Cohorts A (2001-10) & B (2011-19) were created on account of changes in CT scanners. PPV, NPV, sensitivity and specificity rates were calculated for contemporaneous readings and for 2011 and 2019 reinterpretations. 397 CT scans were read as positive for appendicoliths; 167 for A, 230 for B. 246 corresponding specimens had appendicoliths. PPV was 62% overall; 69% for A, 57% for B. 1155 scans were negative for appendicoliths. 191 corresponding specimens had appendicoliths; NPV was 83% overall; 80% for A, 87% for B. 447 specimens had appendicoliths; only 246 were identified by CT. Sensitivity was 55% overall; 48% for A, 66% for B. Specificity was 86% overall (964/1115); 91% for A, 82% for B. Radiologist accuracies varied. Complicated appendicitis is often associated with appendicoliths. The assumption that CT identification of appendicoliths is reliable is unsupported by this study. CT finding of an appendicolith should not be used to exclude patients from antibiotics treatment but rather used in the shared decision-making conversation about management with patients.

Role of Conservative Management in Stump Appendicitis: A Case Series.

Stump appendicitis is a rare, delayed complication of appendectomy. It is seen following both open and laparoscopic appendectomy and may occur weeks to years following the initial appendectomy. We report two cases of stump appendicitis seen at our hospital. Both cases were diagnosed based on radiological findings and successfully managed conservatively with antibiotics. Although the usually recommended treatment for stump appendicitis is completion appendectomy, conservative management may be suitable for some patients. This report highlights the possibility of utilizing a conservative approach in the management of stump appendicitis compared to the recommended operative intervention. Awareness of the possibility of stump appendicitis is crucial for early diagnosis and treatment, to prevent potentially catastrophic complications.

964 Cheques and Balances: A Five-Year Review of Surgical Settlements

Abstract Aim The litigious burden in the NHS has been increasing yearly, costing an estimated £2.5 billion per year in financial settlements. We investigated the causes of general surgical settlements and attributed costs at a district general hospital over a five-year period. Method A retrospective analysis of all general surgical claims between 2016–2021 using the NHS Resolutions Case Management System. Selected cases were those which resulted in out of court financial settlements; whilst these claims have been settled, the trust admitted no negligence in each case. Results A total of 12 settlements were made with a total cost of £249,918 (£8000-£60,000, mean £20,827). Eight of the claims (67%) related to elective cases with four (33%) emergency cases. Of the total cases, 41% and 33% related to management of gallstones and appendicitis respectively. The majority of claims (58%) related to delays in treatment with a total cost of £103,500 (£8000-£35,000), accounting for 41% of total settlement costs. Five cases (42%) were due to harm with a combined total of £146,418 (£9000-£60,000), 59% of the total settlement. Of the claims due to harm, 80% suffered recognised complications of the procedure. Conclusions Increasing litigation in the NHS over the last decade now accounts for 2% of the total NHS budget. The majority of settlements reviewed here were for avoidable delays in elective treatment, with higher financial settlements for well documented surgical complications related to the consent process. Better access to investigations, earlier clinical review, and reductions in delays to elective surgeries may reduce the financial burden of litigation.

767 Group & Save- Are They Required for Laparoscopic Appendicectomies?

Abstract Aim Laparoscopic appendicectomy (LA) is the gold standard surgical management of appendicitis. Serious intraoperative complications, including bleeding, are rare, however in the absence of a local established guideline, it is standard practice to send two group and save (G&S) samples prior to theatre. We aimed to review our post-operative transfusion risk for LA and to establish if routine group and save testing is required as part of the preoperative workup. Method All patients who underwent a laparoscopic appendicectomy in a single centre were reviewed over a 3-month period (April- June 2020). Data was retrieved from an institutional database and up to date electronic records were reviewed for operative details and transfusion history. Results Forty-three appendicectomies performed during audit window, twenty-one of which were laparoscopic. 100% of cases had a single group and save recorded pre-operatively, with 76.2% having a second sample sent, totalling 37 samples. Zero patients in the cohort required a post-operative transfusion. Average cost of a group and save equals £26, a total cost of £962 over a 3-month period. Conclusion Whilst a small study, we have illustrated LA to be a safe procedure with zero incidence of blood transfusion. There are clear benefits of producing a local guideline that G&S are not routinely required for LA, including financial and resource savings, potential reduction in theatre delays, and reduction of workload for staff.

997 Audit Examining the Treatment of Patients Who Developed Post Operative Complications Following Appendicectomy

Abstract Aim To identify trends in management of patients with post operative complications following appendicectomy in a district general hospital. Method The coding department identified patients who were admitted with appendicitis in the previous year and those who developed post operative complications. Data was gathered retrospectively from these patients using their online records. Results Coding identified 270 patients that were admitted between 22/10/20–29/10/21 with appendicitis. 19 patients had post operative complications. 9 had intra-abdominal collections, 5 had wound infections/collections, 3 had an ileus. 15/19 patients with complications underwent imaging, 8 had CT scans and 7 had US scans. Patients waited a mean of 0.4 days between presentation and imaging. Patients waited a mean of 2.2 and median of 0 days between imaging and appendicectomy. 12 patients had complicated appendicitis, 6 had simple appendicitis and 1 had a normal appendix. 16 patients had antibiotics pre and post operatively, 3 did not. The mean length of stay was 5.6 days for patients with complications, compared to a mean length of stay of 3.9 days for all patients with appendicitis. Conclusions Early identification and management of appendicitis reduces morbidity, and our centre appears to have lower than average complication rates. The patients who did develop complications, were generally imaged and operated on efficiently An area of improvement is ensuring all patients undergoing appendicectomies are given at least one preoperative dose of antibiotics and up to 3–5 days post operatively if complicated as per WSES guidelines. We aim to re-audit this after an education drive within our department.

Management of pediatric appendicitis during the COVID-19 pandemic: A nationwide multicenter cohort study

BackgroundThe COVID-19 pandemic has impacted timely access to care for children, including patients with appendicitis. This study aimed to evaluate the effect of the COVID-19 pandemic on management of appendicitis and patient outcomes. MethodsA multicenter retrospective study was performed including 19 children's hospitals from April 2019-October 2020 of children (age≤18 years) diagnosed with appendicitis. Groups were defined by each hospital's city/state stay-at-home orders (SAHO), designating patients as Pre-COVID (Pre-SAHO) or COVID (Post-SAHO). Demographic, treatment, and outcome data were obtained, and univariate and multivariable analysis was performed. ResultsOf 6,014 patients, 2,413 (40.1%) presented during the COVID-19 pandemic. More patients were managed non-operatively during the COVID-19 pandemic compared to before the pandemic (147 (6.1%) vs 144 (4.0%), p < 0.001). Despite this change, there was no difference in the proportion of complicated appendicitis between groups (1,247 (34.6%) vs 849 (35.2%), p = 0.12). COVID era non-operative patients received fewer additional procedures, including interventional radiology (IR) drain placements, compared to pre-COVID non-operative patients (29 (19.7%) vs 69 (47.9%), p < 0.001). On adjusted analysis, factors associated with increased odds of receiving non-operative management included: increasing duration of symptoms (OR=1.01, 95% CI: 1.01–1.012), African American race (OR=2.4, 95% CI: 1.3–4.6), and testing positive for COVID-19 (OR=10.8, 95% CI: 5.4–21.6). ConclusionNon-operative management of appendicitis increased during the COVID-19 pandemic. Additionally, fewer COVID era cases required IR procedures. These changes in the management of pediatric appendicitis during the COVID pandemic demonstrates the potential for future utilization of non-operative management.

Moynihan Prize 1 Antibiotic management of acute appendicitis avoids surgery in over 70% of adults: one-year follow-up from a prospective, multicentre, observational study

Abstract Background Surgeons are sometimes reluctant to manage uncomplicated appendicitis non-operatively. Reasons cited are unknown rates of recurrent appendicitis and the risk of missed appendiceal malignancy. The aim of this study was to address these uncertainties and determine the long-term efficacy of antibiotic versus operative management of appendicitis. Method One-year follow-up of patients enrolled in the multicentre observational COVID:HAREM cohort study during March-June 2020 was undertaken. Patients were diagnosed with appendicitis either clinically or radiologically; initial operative or non-operative management was determined on a case-by-case basis by the responsible surgeon. Outcomes were the one-year appendicectomy rate, resected appendix histology and predictors of antibiotic failure. Results A total of 625 patients who underwent non-operative management were identified from 49 of the original 97 hospital sites. The overall appendicectomy rate at one-year in the initial non-operative group was 29% (180/625), with a median time to appendicectomy of 29 days [IQR 2-124]. Elective appendicectomy accounted for 17% (31/180) of operations with normal histology found in 39% (12/31). The overall normal histology rate was 11% (19/167). There were 7/167 malignancies and 3/167 neuroendocrine tumours identified at delayed operation. The presence of a faecolith (HR 1.72; 95% CI 1.18–2.51) and CRP&amp;gt;300 versus &amp;lt;50 (HR 3.05; 95% CI 1.6–5.81) were independent risk factors for failure of antibiotic-management (n=441). Conclusion The success rate of non-operative appendicitis management was 71% at one-year. Appendicitis recurrence was associated with the presence of a faecolith, malignancy and significantly raised CRP. These factors should be considered when counselling patients on non-operative management.

TH5.9 Role of Ultrasound in Management of Acute Appendicitis

Abstract Aim Assess the outcomes of suspected appendicitis patients who had an abdo-pelvic ultrasound, and whether the scan made a difference to their management. Method Cycle 1: we collected data retrospectively for confirmed appendicitis patients admitted for the period betweeen 03/06/2021–01/09/2021. Clinical coding department supplied a database of EAU admissions diagnised with appendicitis based on histology. Cycle 2: we collected data retrospectively for all surgical patients with acute abdominal pain during the period between 1/11/2021–30/11/2021. Ultrasounds requested were provided by the Radiology department. Admission summaries were used to assess patients' management. Intervention Presentation of Audit results in departmental teaching, Teaching to junior doctors on the NICE guidelines for management of Appendicitis. Results Cycle 1: Out of 60 patients, only 10 were included as most patients had CT scan. 25% of which suggested appendicitis and 25% suggested different pathology. The appendix couldn't be visualised in 75%. Cycle 2: Out of 83 patients, 23 patients were included as suspected appendicitis. Confirmed cases were 4.34%, not visualized were 86.96% and NAD 8.70% (their final diagnosis on discharge: Appendicitis). Other suspected pathologies of biliary, gynaecological and post-op collections were mostly correctly confirmed/denied. Conclusions Ultrasound was very informative in Biliary pathology, Gynae Pathology, Other pathology like Hematoma, post-op collection. However, in terms of suspected appendicitis, it was only informative in a rare occurrence. Of the patients who were diagnosed as Appendicitis in the final diagnosis, only an eighth were confirmed by US. Ultrasound didn't change the management plan in majority of patients with suspected appendicitis.

TU7.7 Cheques and Balances: A Five Year Review of Surgical Settlements

Abstract Aim The litigious burden in the NHS has been increasing yearly, costing an estimated £2.5 billion per year in financial settlements. We investigated the causes of general surgical settlements and attributed costs at a district general hospital over a five-year period. Method A retrospective analysis of all general surgical claims between 2016–2021 using the NHS Resolutions Case Management System. Selected cases were those which resulted in out of court financial settlements; whilst these claims have been settled, the trust admitted no negligence in each case. Results A total of 12 settlements were made with a total cost of £249,918 (£8000-£60,000, mean £20,827). Eight of the claims (67%) related to elective cases with four (33%) emergency cases. Of the total cases, 41% and 33% related to management of gallstones and appendicitis respectively. The majority of claims (58%) related to delays in treatment with a total cost of £103,500 (£8000-£35,000), accounting for 41% of total settlement costs. Five cases (42%) were due to harm with a combined total of £146,418 (£9000-£60,000), 59% of the total settlement. Of the claims due to harm, 80% suffered recognised complications of the procedure. Conclusions Increasing litigation in the NHS over the last decade now accounts for 2% of the total NHS budget. The majority of settlements reviewed here were for avoidable delays in elective treatment, with higher financial settlements for well documented surgical complications related to the consent process. Better access to investigations, earlier clinical review, and reductions in delays to elective surgeries may reduce the financial burden of litigation.

WE8.2 Has the change in emphasis to conservative management of appendicitis during the first wave of COVID- 19 had a longer lasting affect on assessment and management of patients

AimsDuring the first wave of the COVID-19 pandemic (March-June 2020), surgeons were advised where possible to avoid operating on appendicitis due to the perioperative risk for patients and theatre staff. This resulted in an increase in conservative management and a decreased negative appendicectomy rate (NAR) (COVID:HAREM). We sought to assess if the experience in 2020 had changed practice a year on.MethodsData collection was undertaken of patients presenting acutely with appendicitis or clinical appendicitis requiring diagnostic laparoscopy, using the electronic records. Data was collected over the same three-month period in 2019, 2020 and 2021. Patient's electronic records were reviewed.ResultsIn total 174 patients were identified over the three-year period (59, 46 and 69). Mean age was 42 and 55% were female. The number of patients undergoing US scans dropped during the pandemic (36%, 26% and 41%) whereas CT use increased (37%, 63% and 46%). In 2021, conservative management of patients had not returned to pre-pandemic levels (5%, 46% and 19%). NAR were 12%, 0% and 5%. Mean length of stay was unchanged (3.3, 3.9 and 3.5days).ConclusionsThis study demonstrates the change of practice during and following the first wave of pandemic. In 2020, more patients were undergoing a diagnostic imaging and fewer patients were undergoing an operation compared to 2019, demonstrated improvement in the NAR in 2020. Although these changes have dampened in 2021, the trend is still present; there is an improved NAR in 2021 compared to 2019, possibly due to more patients undergoing CT.

Conservative versus Surgical Management of Appendicitis During Pregnancy

Acute appendicitis is the most common non-obstetric surgical emergency during pregnancy. This report presents a case of conservative management of appendicitis during pregnancy. The aim is to discuss the role of conservative treatment for a condition that is routinely treated surgically. This is important because research on the management of appendicitis during pregnancy is limited compared to the general population. Conservative management can be a safe option for uncomplicated appendicitis. However, the increased risk of appendix perforation in pregnancy and implications for foetal health commonly make surgery a more attractive option. This risk is a key driver for higher rates of negative appendectomies during pregnancy. The COVID-19 pandemic provides a unique opportunity to remedy the paucity of research of appendicitis during pregnancy. This is because conservative management was heavily utilised at the start of the pandemic. Therefore, following up pregnant patients in this cohort will provide a valuable insight into the risks and benefits of conservative versus surgical management.

Analysis of appendicitis management during COVID-19 pandemic: A study of Chinese adult cohorts.

Healthcare seeking behavior has been widely impacted due to the restricted movements of individuals during the Coronavirus disease-19 (COVID-19) pandemic. This study aims to perform risk stratification in patients requiring timely intervention during the recovery periods. Operation notes of acute appendicitis (AA) patients within a hospital were analyzed during three six-month periods (23 January-23 July in 2019, 2020, and 2021, respectively). Patient data were collected retrospectively including demographics, pre-emergency status, perioperative information, postoperative outcomes, and follow-up results. 321 patients were included in this study, with 111, 86, and 124 patients in 2019, 2020, and 2021 groups, respectively. The median age of patients decreased by 4 years in 2020 as compared to that in 2019. The proportion of pre-hospitalization symptoms duration of more than 48 h in the 2020 group was higher (36.05% in 2020 vs. 22.52% in 2019). Length of hospital stay (LOS) in 2020 was shorter than it was during the same period in 2019 (4.77 vs. 5.64) and LOS in 2021 was shorter than in 2019 (4.13 vs. 5.64). Compared to the lockdown period, the proportion of patients with recurrent AA was higher in the post-lockdown period (15.1% vs. 27.4%). The median age was 34 years (vaccinated) vs. 37 years (unvaccinated). Logistic regression suggests that elevated C-reactive protein (CRP) (OR = 1.018, CI = 1.010-1.028), white cell count (WBC) (OR = 1.207, CI = 1.079-1.350), female (OR = 2.958, CI = 1.286-6.802), recurrent (OR = 3.865, CI = 1.149-12.997), and fecalith (OR = 2.308, CI = 1.007-5.289) were associated with complicated appendicitis (CA). The lockdown measures during the COVID-19 epidemic are shown to be correlated with a reduction in the proportion of AA patients who underwent surgery, particularly in older adults. Risk factors for CA include elevated CRP, WBC, female, recurrent, and fecalith.

The erector spinae block: a novel approach to pain management in acute appendicitis

BackgroundAcute abdominal pain is one of the most common complaints that patients present with in the emergency room and has long been a challenge to effectively manage without relying on opioid analgesia. The use of ultrasound-guided peripheral nerve blocks (UGRA) represents a new frontier in multimodal pain control regimens in the acute setting. An erector spinae plane (ESP) block is believed to mediate pain relief in multiple dermatomes through blockage of both visceral and somatic nerves. Analgesia provided by a single injection can help keep a patient comfortable for hours without breakthrough pain and the subsequent need for frequent redosing of opioid pain medication. To this date, there is very limited evidence of an ESP block in the utilization of acute appendicitis in the emergency department.Case reportThis case report presents a 26-year-old female with a past medical history of polycystic ovarian syndrome (PCOS) and a tubal ligation that presented with 7/10 right lower quadrant abdominal pain that began 1 h prior to arrival. She stated that she felt like this was similar to her PCOS exacerbations in the past. During her evaluation, she underwent a computed tomography (CT) scan of her abdomen and pelvis that was remarkable for acute, uncomplicated appendicitis. She was given 4 mg of morphine for her pain with little response, so the offer was made for an erector spinae block that the patient elected to receive. After being consented both for the procedure and for research, she received a right-sided erector spinae block with 20 mL’s of 0.2% ropivacaine (2 mg/mL) at the L1 vertebral level. After approximately 15 min, she stated that she had a reduction in her pain from a 6/10 to a 1/10 that persisted throughout the rest of her stay in the emergency department.

Demonstration of a new entity of non-perforated appendicitis through studying cluster of appendicitis

Differential diagnosis and management for perforated appendicitis and non-perforated appendicitis are current hot topics. The aim of this study is to demonstrate a new entity of non-perforated appendicitis, “acute hemorrhagic appendicitis” through studying cluster of acute appendicitis among Tibetan students at a high school in central China. Over the 11-year period, there were 120 patients with more female patients (102 of 499, 20.4%) than male patients (18 of 474, 3.8%) among 973 Tibetan students. 117 patients’ clinical data were available. Clinical manifestations were identical to classic appendicitis. However, axilla temperature, white blood cell counts and neutrophil level were elevated mildly in 12 (10.3%), 19 (16.2%) and 12 (10.3%) patients respectively. Pathologically, the resected appendices exhibited focal or diffuse hemorrhages in mucosa and/or submucosa, and infiltration by eosinophil and by lymphocytes. No patients had perforated appendicitis. The median time from the onset to surgery was 3 days (IQR, 2–4). All patients were discharged with full recovery. In conclusion, “acute hemorrhagic appendicitis” represented a new entity of non-perforated appendicitis with unique cause and pathogenesis, which might be treated with antibiotics alone or self-limited. Studying the cluster is a reliable method to find new entity of appendicitis.