Neonatal Perforated Appendicitis Attributed to Localized Necrotizing Enterocolitis of the Appendix: A Review

Preterm Birth and Infantile Appendicitis

OBJECTIVE

To investigate the potential association between preterm birth and infantile appendicitis.

METHODS

We conducted a retrospective, multicenter, matched case-control study. This study included consecutive patients <1 year of age with surgery- or autopsy-confirmed appendicitis, admitted between December 2007 and May 2023. For each case, 10 healthy infants were randomly selected and matched by age. Infants were categorized as neonates (0 to 28 days) or older infants (>28 days and <1 year).

RESULTS

The study included 106 infants diagnosed with appendicitis (median age 2.4 months) and 1060 age-matched healthy controls. In the univariate analysis, preterm birth was significantly associated with the development of appendicitis within the first year of life (odds ratio [OR], 4.23; 95% confidence interval [CI], 2.67-6.70). Other factors associated with a higher risk of infantile appendicitis included being male (OR, 1.91; 95%CI, 1.25-2.94), weight-for-age z-score (OR, 0.72; 95%CI, 0.64-0.81), and exclusively fed on formula (OR, 2.95; 95%CI, 1.77-4.91). In multivariable analyses, preterm remained significantly associated with appendicitis (adjusted OR, 3.32; 95%CI, 1.76-6.24). Subgroup analysis revealed that a preterm birth history increased the risk of appendicitis in both neonates (adjusted OR, 4.56; 95%CI, 2.14-9.71) and older infants (adjusted OR, 3.63; 95%CI, 1.72-7.65). However, preterm did not significantly influence the incidence of appendiceal perforation.

CONCLUSIONS

Preterm infants have an increased risk of appendicitis during the first year of life. A preterm birth history may help improve the timely diagnosis of infantile appendicitis.

Neonatal perforated appendicitis: a presentation of necrotising enterocolitis?

In this case report, we present a late preterm growth-restricted neonate who developed signs of feeding intolerance on the second day of life, which progressed to frank peritonitis with perforation by the end of the second week of life. As necrotising enterocolitis was considered the most likely diagnosis, a glove drain was placed in the flanks. The neonate did not improve, and surgical exploration was done after medical stabilisation. On exploration, the neonate was found to have appendicular perforation and an appendicectomy was performed. During surgery, the rest of the gut was noted to be healthy. Histopathological examination of the appendix showed transmural inflammation, focal infarction and perforation. The postoperative period was uneventful, and the neonate showed rapid improvement and reached full enteral feeding in the next 5 days. Antibiotic therapy promptly resolved bacterial peritonitis, and the neonate was discharged successfully.

Clinical features and treatment outcomes of infantile appendicitis: a multicentre study

Appendicitis in infants is a life-threatening condition that is seldom studied. Our purpose was to conduct a comprehensive evaluation of appendicitis in this age group. This was a multicenter retrospective study. Patients aged under one year with surgically confirmed appendicitis during January, 2010 to May, 2022 were identified from four institutional databases. The patients were grouped as neonates or older infants based on their age at the onset of symptoms associated with acute appendicitis. The study encompassed 98 infants, with median age of 66.5 (IQR, 13.8-176.0) days. Neonates were more likely to exhibit abdominal distension (64.9%) and fever (56.8%), while older infants more frequently presented with fever (88.5%) and vomiting (49.2%). Most patients (76.5%) were misdiagnosed during their initial clinical encounter, with a -rate was 3.1% (3 deaths), with neonates exhibiting a rate of 5.4%, and older infants 1.6%. Compared to older infants, neonates showed a higher incidence of appendiceal perforation (OR, 2.9; 95%CI, 1.1-8.1), mechanical ventilation (OR, 9.5; 95%CI, 3.1-29.2), and ICU admission (OR, 16.1; 95%CI, 5.6-45.7). However, there were no significant differences in mortality rates, 30-day readmission rates, and surgical complications between the two groups.

CONCLUSION

Although most infants with appendicitis were misdiagnosed during the first clinical encounter, the observed mortality rates were considerably lower than previously reported. While neonates and infants over 28 days displayed differing clinical presentations and disease severity, their outcomes were similar.

WHAT IS KNOWN

• Appendicitis in infants is a critical yet underemphasized health concern, often misdiagnosed at initial clinical encounters due to its atypical presentation and non-specific symptoms. • The mortality rates in the neonates with appendicitis was 23% during the past decades.

WHAT IS NEW

• The neonates and older infants displayed differing clinical presentations and disease severity. The treatment outcomes were similar. • The mortality rate for infantile appendicitis (3.1%) was significantly lower than historically reported.

Appendicitis and its associated mortality and morbidity in infants up to 3 months of age: A systematic review

Background and Aims

Although appendicitis is rare in young infants, the reported mortality is high. Primary aim of this systematic review was to provide updated insights in the mortality and morbidity (postoperative complications, Clavien-Dindo grades I-IV) of appendicitis in infants ≤3 months of age. Secondary aims comprised the evaluation of patient characteristics, diagnostic work-up, treatment strategies, comorbidity, and factors associated with poor outcome.

Methods

This systematic review was reported according to the PRISMA statement with a search performed in Pubmed, Embase and Web of Science (up to September 5th 2022). Original articles (published in English ≥1980) reporting on infants ≤3 months of age with appendicitis were included. Both patients with abdominal appendicitis and herniated appendicitis (such as Amyand's hernia) were considered. Data were provided descriptively.

Results

In total, 131 articles were included encompassing 242 cases after identification of 4294 records. Overall, 184 (76%) of the 242 patients had abdominal and 58 (24%) had herniated appendicitis. Two-hundred (83%) of the patients were newborns (≤28 days) and 42 (17%) were infants between 29 days and ≤3 months of age. Either immediate, or after initial conservative treatment, 236 (98%) patients underwent surgical treatment. Some 168 (69%) patients had perforated appendicitis. Mortality was reported in 20 (8%) patients and morbidity in an additional 18 (8%). All fatal cases had abdominal appendicitis and fatal outcome was relatively more often reported in newborns, term patients, patients with relevant comorbidity, nonperforated appendicitis and those presented from home.

Conclusion

Mortality was reported in 20 (8%) infants ≤3 months of age and additional morbidity in 18 (8%). All patients with fatal outcome had abdominal appendicitis. Several patient characteristics were relatively more often reported in infants with poor outcome and adequate monitoring, early recognition and prompt treatment may favour the outcome.

Acute Abdomen in an Extremely Low-Birth-Weight Preterm Neonate: A Case of Appendicitis

INTRODUCTION

Neonatal appendicitis is a very rare surgical entity. Non-specific symptoms such as feeding intolerance, abdominal distension, vomiting, increased gastric residue, lethargy, and fever may be present. The majority of reported cases could not be identified early. In this report, we present an extremely low-birth-weight preterm neonate who has been diagnosed with appendicitis.

CASE PRESENTATION

A 980-gram preterm baby girl was born at 31 1/7 weeks of gestation. The physical examination was normal at birth. Her initial clinical course was uneventful. On the 7th day of life, she developed abdominal distention and tenderness. She had an episode of bloody stools and bilious vomiting. An abdominal X-ray suggested localized perforation in the cecum with an air-fluid level in the right lower quadrant. The clinical findings suggested necrotizing enterocolitis and perforation, and a diagnostic laparotomy was performed. The bowel was found to be normal with a necrotic appendix. The appendectomy was performed. She was discharged from the neonatal intensive care unit with no complications.

CONCLUSION

Appendicitis is extremely rare in the neonatal period. It is quite challenging to evaluate the presentation accurately, which causes a delay in diagnosis. However, if an atypical NEC or peritonitis is present, appendicitis should be considered. Early diagnosis and timely surgical intervention improve the prognosis of neonatal appendicitis.

Analysis of Cases of Neonatal Appendicitis from a Tertiary Care Unit

OBJECTIVE

To compare the clinical characteristics and prognosis of neonatal appendicitis (NA) alone and neonatal appendicitis with neonatal necrotizing enterocolitis (NEC) to improve the early recognition and diagnosis rate for this type of disease.

METHODS

Cases of appendicitis proved by operation and pathology younger than 28 d old in the authors hospital from 1990 to 2021 were retrospectively analyzed. According to whether combine with NEC, the cases were divided into two groups, analyzes the clinical characteristics.

RESULTS

A total of 48 patients were enrolled, 15 cases in the NA group and 33 cases in the NEC with NA group. The age of onset, time from onset of symptoms to surgical intervention were both earlier in the NEC with NA group (p < 0.05). The preoperative white blood cells (WBC) and platelets (PLT) in the NA group were higher (p < 0.05). NEC with NA was more likely to be complicated with neonatal pneumonia and sepsis before surgery (p < 0.05). The main clinical symptom of NA was abdominal distension, while the other was bloody stool. The positive rate of ultrasound was high before the operation. The perforation rate of the appendix was very high (NA 100% vs. NEC 57.6%). In the NA group, 100% underwent appendectomy and 78.8% in the NEC with NA group underwent terminal ileostomy and appendectomy.

CONCLUSION

The incidence of neonatal appendicitis is low. It is easily misdiagnosed as NEC. The perforation rate is very high, it is recommended to operate as soon as possible, and the prognosis is good.

Neonatal and Infant Appendicitis

Neonatal appendicitis is a rare disease with a high mortality rate. Appendicitis is difficult to diagnose in neonatal and infant populations because it mimics other more common conditions in these age groups. Furthermore, signs and symptoms of appendicitis are often nonspecific in nonverbal patients and a high index of suspicion is necessary to initiate the appropriate diagnostic work-up. The keys to successful management of appendicitis in infants include keeping the diagnosis on the differential in the setting of unexplained intra-abdominal sepsis, following a diagnostic algorithm in the work-up of infant abdominal pathology, and performing appendectomy once the diagnosis is confirmed.