Effect of peritoneal drainage on the prognosis following appendectomy in pediatric patients with appendicitis: a retrospective study based on appendicitis grade.

Background: This study aimed to assess the impact of peritoneal drainage and its type on prognosis, encompassing postoperative recovery and complications, in pediatric patients (≤ 16 years old) following appendectomy based on the grade of appendicitis.

Methods: In this retrospective study, we analyzed pediatric patients (≤ 16 years old) with appendicitis who met the inclusion and exclusion criteria in our center from January 2017 to January 2024 and classified them into grade I-V based on the grade of appendicitis, with V representing the most serious cases. The patients were grouped according to drainage status and type. The main clinical outcomes included postoperative rehabilitation indexes such as time to resume a soft diet, time to remove the drain, duration of postoperative antibiotic use and length of hospitalization (LOH), as well as postoperative complications including intra-abdominal abscess (IAA), ileus and wound infection (WI), and readmission within 30 days after surgery.

Results: A total of 385 pediatric patients with appendicitis were included in the study and divided into No-drainage (ND) group (n = 74), Passive drainage (PD) group (n = 246) and Active drainage (AD) group (n = 65) according to drainage status and type. Compared to the other two groups, the ND group had a significantly shorter time to resume a soft diet, duration of postoperative antibiotic use and LOH, and these differences were statistically significant. Similar findings were observed in grade I patients too (P < 0.05). In all cases examined here, the AD group had a significantly shorter time for drain removal compared to the PD group (3.04 [1-12] vs 2.74 [1-15], P = 0.049); this difference was also evident among grade I patients (2.80 [1-6] vs 2.47 [1-9], P = 0.019). Furthermore, within the same grade, only in grade IV did the AD group exhibit a shorter duration of postoperative antibiotic use compared to the PD group (4.75 [4-5] vs 8.33 [5-15], P = 0.009). Additionally, the LOH in the AD group was longer than that in the PD group (8.00 [4-13] vs 4.75 [4-5], P = 0.025). Among all cases, the ND group exhibited significantly lower incidences of overall complications and WI compared to the other two groups (P < 0.05). Additionally, the incidence of IAA in the ND group was significantly lower than that in the PD group (0% vs 5.3%, P = 0.008 < 0.0167). Furthermore, although there were no statistically significant differences in the incidence of overall complications, IAA, ileus, and WI between the PD and AD groups during grade ≥ II analysis (P > 0.05), a higher readmission rate within 30 days was observed in the PD group compared to the AD group; however, these differences were not statistically significant (P > 0.05). Moreover, multivariate analysis revealed that a higher grade of appendicitis was associated with an increased risk of overall complications and IAA as well as a longer duration of postoperative antibiotic use and LOH.

Conclusion: The appendicitis grade is a crucial indicator for predicting postoperative IAA and LOH. In patients with grade I appendicitis, peritoneal drainage, even if active drainage, is not recommended; For patients with grade ≥ II appendicitis, active drainage may be more effective than passive drainage in reducing the duration of postoperative antibiotic use and LOH.