Outcomes of Premature Infants With Type C Esophageal Atresia.

BACKGROUND: To review the outcomes of premature patients with type C esophageal atresia (EA). METHODS: In this retrospective cohort study, charts of patients of type C EA patients were reviewed from 1992 to 2022. Outcomes of premature patients were compared to term patients. Preterm patients were analyzed to compare outcomes of infants with very low birth weights (VLBW) to patients >1,500 g as well as primary versus delayed anastomosis. RESULTS: Among 192 type C EA, 67 were premature. Median and interquartile range (IQR) gestational age and birth weight of preterm patients were 34 [33-36] weeks and 1965 [1740-2290] g. Delayed anastomosis was performed in 12 (18%) preterm vs. 3 (2%) term patients (p = 0.0003). Short-term postoperative outcomes were similar between preterm and term patients, except for recurrent fistula (16% vs. 6%, p = 0.01). Prematurity was associated with an increased need for long-term enteral tube feeding (56% vs. 10%, p = 0.0001) and parenteral nutrition (10 days vs. 0 days, p = 0.0004). The length of stay was 3 times longer when patients were premature (50 days vs. 17 days, p = 0.002). Delayed surgery in preterm patients was associated with post-operative leaks, strictures, recurrent fistula, prolonged enteral tube feeding, and gastrostomy insertion. Patients with very low birth weight (VLBW) were compared to other preterm patients and showed no difference in terms of rate of delayed surgery, and post-operative outcomes. CONCLUSION: Despite increased prematurity-related comorbidities and low birth weight, premature infants with type C EA/TEF have similar post-operative outcomes to term patients though recurrent fistula was more frequent with prematurity. TYPE OF STUDY: Retrospective cohort study. LEVEL OF EVIDENCE: III.

Pediatric living donor liver transplant for Budd-Chiari syndrome using a cryopreserved pulmonary vein graft for retro-hepatic vena cava reconstruction: A case report.

INTRODUCTION: In pediatric patients with Budd-Chiari syndrome (BCS), living donor liver transplantation (LDLT) raises substantial challenges regarding IVC reconstruction. CASE PRESENTATION: We present a case of an 8-year-old girl with BCS caused by myeloproliferative syndrome with JAK2 V617F mutation. She had a complete thrombosis of the inferior vena cava (IVC) with multiple collaterals, developing a Budd-Chiari syndrome. She underwent LDLT with IVC reconstruction with a cryopreserved pulmonary vein graft obtained from a provincial biobank. The living donor underwent a laparoscopic-assisted left lateral hepatectomy. The reconstruction of the vena cava took place on the back table and the liver was implanted en bloc with the reconstructed IVC in the recipient. Anticoagulation was immediately restarted after the surgery because of her pro-thrombotic state. Her postoperative course was complicated by a biliary anastomotic leak and an infected biloma. The patient recovered progressively and remained well on outpatient clinic follow-up 32 weeks after the procedure. CONCLUSION: IVC reconstruction using a cryopreserved pulmonary vein graft is a valid option during LDLT for pediatric patients with BCS where reconstruction of the IVC entails considerable challenges. Early referral to a pediatric liver transplant facility with a multidisciplinary team is also important in the management of pediatric patients with BCS.

Open and laparoscopic inguinal hernia repair in children: A regional experience.

PURPOSE: The optimal approach for pediatric inguinal hernia repair continues to be debated. We conducted a regional retrospective study to assess rates of recurrence and metachronous hernias after open repair (OPEN) and laparoscopic repair (LAP) METHODS: A retrospective cohort study was conducted at two children's hospitals that serve a region of approximately 4 million people. All patients < 14 years old undergoing OPEN or LAP by pediatric surgeons during a 5-year period (2011 - 2015) were analyzed after a minimum follow up of 4 years. Cox proportional regression was used to compare the effect of surgical approach on hernia recurrence and metachronous contralateral hernias. RESULTS: A total of 1,952 patients, 587 female (30%) and 1365 male (70%), had 2305 hernias repaired. Median post operative follow up time was 6.6 years (range 4-9 years). OPEN and LAP were performed for 1827 (79%) and 478 (21%) hernias, respectively. There were no significant differences in rate of prematurity, age at repair, or frequency of emergent repair. LAP was associated with a lower incidence of metachronous contralateral hernias compared to OPEN (1.4% vs 3.8%, p = 0.047), and a higher incidence of recurrence (9% vs 0.9%, p < 0.001). After adjusting for confounders, LAP had a higher rate of recurrence than OPEN (hazard ratio 10.4, 95% CI 6-18.1).The recurrence rate did not decrease over the study period (p = 0.731). CONCLUSION: Laparoscopic inguinal hernia repair in children resulted in a modest decrease in the incidence of metachronous hernias, at the cost of a significant increase in recurrence. TYPE OF STUDY: Retrospective Comparative Study. LEVEL OF EVIDENCE: Level III.

Indocyanine green fluorescence angiography in pediatric intestinal resections: A first prospective mixed methods clinical trial.

BACKGROUND: The aim of this study was to establish the feasibility and safety of the use of indocyanine green technology during pediatric intestinal resections. While indocyanine green fluorescence angiography (ICG-FA) has been advocated as an imaging technique to assess bowel perfusion in adults, few studies have evaluated this technology in a pediatric context. METHODS: A prospective clinical trial was conducted. Patients 16 years old or younger undergoing a surgery potentially requiring an intestinal resection were eligible. Patients received a standardized intravenous injection of indocyanine green and intestinal perfusion was evaluated. The study endpoints included safety, impact on bowel resection and feasibility and acceptance of ICG-FA in this population. RESULTS: From May 2020 to March 2021, 30 consecutive patients were included in this trial. Final analysis was done on 28 patients with a median age of 15.00 [6.36,85.00] weeks and weight of 5.58 [3.64,11.70] kg at surgery. Adequate fluorescence was achieved in less than one minute for all cases with an average dose of 0.14 mg/kg. No adverse event related to indocyanine green occurred. ICG-FA versus standard assessment of potential resection sites differed in 62% (95% IC 0.41-0.82) of our cases. Qualitative analysis demonstrated that 95% of the surgical team agreed that ICG-FA was safe. CONCLUSIONS: The use of ICG-FA is feasible and safe for pediatric intestinal resections. Introduction of ICG-FA was simple and acceptance rates were high within the surgical team. This fluorescence imaging may be a valuable imaging technology for intestinal resections in pediatric surgery.

Treatment and Outcomes of Congenital Ovarian Cysts A Study by the Canadian Consortium for Research in Pediatric Surgery (CanCORPS).

OBJECTIVE: We conducted a multicenter study to assess treatments and outcomes in a national cohort of infants with congenital ovarian cysts. SUMMARY BACKGROUND DATA: Wide variability exists in the treatment of congenital ovarian cysts. The effects of various treatment strategies on outcomes, specifically ovarian preservation, are not known. METHODS: Female infants diagnosed with congenital intra-abdominal cysts between 2013 and 2017 at 10 Canadian pediatric surgical centers were retrospectively evaluated. Sonographic characteristics, median time to cyst resolution, incidence of ovarian preservation, and predictors of surgery were evaluated. Subgroup analyses were performed in patients with complex cysts and cysts ≥40 mm in diameter. RESULTS: The study population included 189 neonates. Median gestational age at diagnosis and median maximal prenatal cyst diameter were 33 weeks and 40 mm, respectively. Cysts resolved spontaneously in 117 patients (62%), 14 (7%) prenatally, and the remainder at a median age of 124 days. Intervention occurred in 61 patients (32%), including prenatal aspiration (2, 3%), ovary sparing resection (14, 23%), or oophorectomy (45, 74%). Surgery occurred at a median age of 7.4weeks. Independent predictors of surgery included postnatal cyst diameter ≥40 mm [odds ratio (OR) 6.19, 95% confidence interval (CI) 1.66-35.9] and sonographic complex cyst character (OR 63.6, 95% CI 10.9-1232). There was no significant difference in the odds of ovarian preservation (OR 3.06, 95% CI 0.86 -13.2) between patients who underwent early surgery (n = 22) and those initially observed for at least 3 months (n = 131). CONCLUSIONS: Most congenital ovarian cysts are asymptomatic and spontaneously resolve. Early surgical intervention does not increase ovarian preservation.

Differentiating congenital ovarian cysts from other abdominal cystic lesions in female infants: A study by the Canadian Consortium for Research in Pediatric Surgery (CanCORPS).

PURPOSE: The origin of congenital abdominal cysts in the female fetus often dictates management. While most arise from the ovary and are often managed non-operatively, some are non-ovarian and are frequently removed. We analyzed a national sample of female infants with congenital abdominal cysts to elucidate prenatal and postnatal factors associated with the diagnosis of a non-ovarian cyst. METHODS: A retrospective cohort study of female infants who were prenatally diagnosed with abdominal cysts between 2013 and 2017 at 10 Canadian pediatric surgical centres was performed. Clinical characteristics, pre- and postnatal sonographic findings, and cyst trajectories were compared between patients with proven ovarian etiology and those with cysts arising from other organs. RESULTS: Of 185 infants with prenatally diagnosed abdominal cysts, 22 (12%) were non-ovarian, five of which had clear non-ovarian organ of origin on prenatal ultrasound. Comparison of the other 17 cysts with 163 congenital ovarian cysts showed the following factors to be associated with a non-ovarian origin: earlier gestational age at diagnosis (23.5 vs 33.5 weeks, p <0.001), smaller diameter on first prenatal ultrasound (15.8 vs. 39.7 mm, p <0.001), change in sonographic character from simple to complex (87% vs 22%, p <0.001), and postnatal sonographic characteristics of complex cyst (87% vs. 48%, p = 0.004). CONCLUSION: Clear organ of origin, diagnosis earlier in gestation, smaller initial prenatal cyst diameter, and sonographic cyst character change differentiate congenital non-ovarian cysts from their ovarian counterparts. These characteristics may be used to guide diagnosis and management.

Maternal risk factors for paediatric inguinal hernia.

BACKGROUND: Risk factors for paediatric inguinal hernia are poorly understood. This longitudinal cohort study assessed whether children with a maternal history of inguinal hernia or connective tissue disorders have a higher risk of developing inguinal hernias before 13 years of age. METHODS: The study included children followed up between birth and 13 years of age in Quebec, Canada, 2006-2019. Newborns whose mothers had inguinal hernias or connective tissue disorders were followed over time to identify future hospital admissions for inguinal hernia. Cox proportional hazards regression adjusted for patient characteristics was used to estimate hazard ratios (HRs) and 95 per cent confidence intervals for the association between maternal hernia or connective tissue disorders and future childhood hernias. Associations in girls and boys were examined separately. RESULTS: The study included 786 322 children with 6 186 448 person-years of follow-up. There were 6861 children with inguinal hernias, corresponding to an incidence of 11.1 per 10 000 person-years. Children with a maternal history of inguinal hernia had 2.92 (95 per cent c.i. 2.39 to 3.58) times the risk of having inguinal hernias relative to children whose mothers had no such history. Children with a maternal history of connective tissue disorders had 1.30 (1.00 to 1.68) times the risk. Maternal hernias were strongly associated with risk of inguinal hernias in girls (HR 5.34, 3.82 to 7.47), whereas maternal connective tissue disorders were associated with inguinal hernias in boys (HR 1.35, 1.02 to 1.79). CONCLUSION: Paediatric inguinal hernias may be associated with maternal inguinal hernias and connective tissue disorders, but the underlying reason for this relationship requires further investigation.

In this study of 786 322 children in Canada from 2006 to 2019, it was found that children whose mothers had an inguinal hernia or connective tissue disorder were more at risk of developing a hernia themselves. Repairs for inguinal hernia are among the most common operations performed in children. The results showed that girls whose mothers had an inguinal hernia had more than five times the risk of developing an inguinal hernia before 13 years of age. Boys whose mothers had connective tissue disorders had a 35 per cent greater risk of inguinal hernia. These findings suggest that inguinal hernias may be inherited.

Microsurgical and Endovascular Management of Congenital Iliac Aneurysms in the Neonatal Period: Two Cases and a Literature Review.

INTRODUCTION: Congenital aneurysms of major arteries are very rare diagnoses and prognosis can be poor if treatment is not initiated rapidly. This is the presentation of two cases of infants with congenital iliac aneurysms who underwent treatment in the neonatal period. The report then proceeds with a literature review of paediatric iliac aneurysms. REPORT: Case 1: A female neonate was diagnosed antenatally with right common iliac (CIA) and internal iliac (IIA) artery aneurysms. Embolisation on day of life (DOL) eight was impossible because of partial thrombosis. The infant was subsequently observed for several months and the aneurysm was injected percutaneously with thrombin on DOL 78. A small residual aneurysm was coil embolised at five months of age. Satisfactory results were observed at one year follow up. Case 2: A female neonate was diagnosed antenatally on routine third trimester ultrasound with voluminous, bilateral CIA aneurysms. The patient underwent surgery on DOL 9 for aneurysm resection and microsurgical vascular reconstruction. The intervention was successful with triphasic flow through the anastomoses on colour Doppler ultrasound at six week follow up. DISCUSSION: Ten cases of congenital iliac aneurysms have been reported previously, with just two diagnosed in the neonatal period and eight undergoing surgical intervention. Definitive management to avoid aneurysm rupture or thrombosis should be timed carefully, and sometimes delayed with watchful waiting, to maximise success and minimise complications. Surgery is the key treatment modality, but endovascular intervention can be considered in selected cases. Congenital iliac aneurysms should be addressed at the safest time for the patient. Following resection, primary microvascular anastomosis is the ideal reconstructive technique, but other options for neonates have been described. Endovascular treatment should be considered for anatomically amenable saccular aneurysms.

The Use of Indocyanine Green Fluorescence Angiography in Pediatric Surgery: A Systematic Review and Narrative Analysis.

Purpose: Indocyanine green fluorescence angiography (ICG-FA) is a validated non-invasive imaging technique used to assess tissue vascularization and guide intraoperative decisions in many surgical fields including plastic surgery, neurosurgery, and general surgery. While this technology is well-established in adult surgery, it remains sparsely used in pediatric surgery. Our aim was to systematically review and provide an overview of all available evidence on the perioperative use of indocyanine green fluorescence angiography in pediatric surgical patients. Methods: We conducted a systematic review with narrative synthesis in conformity with the PRISMA guidelines using PubMed, Medline, All EBM Reviews, EMBASE, PsycINFO, and CINAHL COMPLETE databases to identify articles describing the perioperative use of ICG-FA in pediatric patients. Two independent authors screened all included articles for eligibility and inclusion criteria. We extracted data on study design, demographics, surgical indications, indocyanine green dose, and perioperative outcomes. We developed a risk of bias assessment tool to evaluate the methodological quality of included studies. Results: Of 1,031 articles retrieved, a total of 64 articles published between 2003 and 2020 were included reporting on 664 pediatric patients. Most articles were case reports and case series (n = 36; 56%). No adverse events related to ICG-FA were reported in the included articles. Risk of bias was high. We did not conduct a meta-analysis given the heterogeneous nature of the populations, interventions, and outcome measures. A narrative synthesis is presented. Conclusion: Indocyanine green fluorescence angiography is a safe imaging technology and its use is increasing rapidly in pediatric surgical specialties. However, the quality of evidence supporting this trend currently appears low. Case-control and randomized trials are needed to determine the adequate pediatric dose and to confirm the potential benefits of ICG-FA in pediatric surgical patients. Systematic Review Registration: This study was registered on Prospero a priori, identifier: CRD42020151981.

Erratum to: Neonatal Microsurgical Repair of a Congenital Abdominal Aortic Aneurysm with a Cadaveric Graft.

[This corrects the article DOI: 10.1055/s-0041-1723019.].

Maternal mental disorders and risk of pathological abdominal conditions in children.

The etiology of pediatric abdominal disorders is poorly understood, and the relationship with maternal mental health is understudied. We sought to determine the association between maternal psychiatric disorders and abdominal conditions in childhood. We performed a retrospective cohort study of 1,080,518 newborns in Quebec, Canada, between 2006 and 2020. We identified maternal mental disorders before or during pregnancy and computed the incidence of abdominal disorders in offspring before 1 year of age. Outcomes included Hirschsprung disease; hypertrophic pyloric stenosis; and esophageal, intestinal, and biliary atresia. We calculated adjusted risk ratios (RR) with 95% confidence intervals (CI) for the association of maternal mental disorders with these pediatric abdominal disorders. Among 51,371 children exposed to maternal mental disorders, 200 children had an abdominal condition, for a rate of 38.9 cases per 10,000 children (95% CI 33.6-44.3) compared with 27.7 per 10,000 for children who were unexposed to maternal mental disorders (95% CI 26.7-28.7). Compared with no mental disorder, maternal mental disorders were associated with hypertrophic pyloric stenosis (RR 1.39, 95% CI 1.16-1.68). Associations were stronger for severe mental disorders and were more marked for depression and stress and anxiety disorders. Maternal mental disorders are associated with the risk of hypertrophic pyloric stenosis in offspring. The origin of hypertrophic pyloric stenosis may relate to maternal mental disorders that were present during pregnancy.

Neonatal Microsurgical Repair of a Congenital Abdominal Aortic Aneurysm with a Cadaveric Graft.

Congenital abdominal aortic aneurysms (AAA) are an extremely rare entity. We present the case of a female fetus diagnosed with an AAA on routine prenatal ultrasound. A postnatal computed tomography angiogram revealed an infrarenal AAA with a narrow proximal neck. Surgery was performed on day of life 14 using a cadaveric femoral artery graft. The proximal anastomosis was performed under the microscope given the severity of the aortic stenosis and the proximity of the renal arteries. The patient's postoperative course was uneventful and she is developing normally 1 year after surgery. The graft remains permeable, albeit with evidence of proximal and distal stenosis and graft calcification on imaging.

Appendectomy Versus Observation for Appendicitis in Neutropenic Children With Cancer.

BACKGROUND: Optimal management of neutropenic appendicitis (NA) in children undergoing cancer therapy remains undefined. Management strategies include upfront appendectomy or initial nonoperative management. We aimed to characterize the effect of management strategy on complications and length of stay (LOS) and describe implications for chemotherapy delay or alteration. METHODS: Sites from the Pediatric Surgery Oncology Research Collaborative performed a retrospective review of children with NA over a 6-year period. RESULTS: Sixty-six children, with a median age of 11 years (range 1-17), were identified with NA while undergoing cancer treatment. The most common cancer diagnoses were leukemia (62%) and brain tumor (12%). Upfront appendectomy was performed in 41% of patients; the remainder had initial nonoperative management. Rates of abscess or perforation at diagnosis were equivalent in the groups (30% vs 24%; P = .23). Of patients who had initial nonoperative management, 46% (17 of 37) underwent delayed appendectomy during the same hospitalization. Delayed appendectomy was due to failure of initial nonoperative management in 65% (n = 11) and count recovery in 35% (n = 6). Cancer therapy was delayed in 35% (n = 23). Initial nonoperative management was associated with a delay in cancer treatment (46% vs. 22%, P = .05) and longer LOS (29 vs 12 days; P = .01). Patients who had initial nonoperative management and delayed appendectomy had a higher rate of postoperative complications (P < .01). CONCLUSIONS: In pediatric patients with NA from oncologic treatment, upfront appendectomy resulted in lower complication rates, reduced LOS, and fewer alterations in chemotherapy regimens compared to initial nonoperative management.

Thoracoscopy vs thoracotomy for the management of metastatic osteosarcoma: A Pediatric Surgical Oncology Research Collaborative Study.

Complete surgical resection of pulmonary metastatic disease in patients with osteosarcoma is crucial to long-term survival. Open thoracotomy allows palpation of nodules not identified on imaging but the impact on survival is unknown. The objective of this study was to compare overall survival (OS) and pulmonary disease-free survival (DFS) in children who underwent thoracotomy vs thoracoscopic surgery for pulmonary metastasectomy. A multi-institutional collaborative group retrospectively reviewed 202 pediatric patients with osteosarcoma who underwent pulmonary metastasectomy by thoracotomy (n = 154) or thoracoscopy (n = 48). Results were analyzed by Kaplan-Meier survival estimates and multivariate Cox proportional hazard regression models. With median follow-up of 45 months, 135 (67.5%) patients had a pulmonary relapse and 95 (47%) patients were deceased. Kaplan-Meier analysis showed no significant difference in 5-year pulmonary DFS (25% vs 38%; P = .18) or OS (49% vs 42%, P = .37) between the surgical approaches of thoracotomy and thoracoscopy. In Cox regression analysis controlling for other factors impacting outcome, there was a significantly increased risk of mortality (HR 2.11; P = .027; 95% CI 1.09-4.09) but not pulmonary recurrence (HR 0.96; P = .90; 95% CI 0.52-1.79) with a thoracoscopic approach. However, in the subset analysis limited to patients with oligometastatic disease, thoracoscopy had no increased risk of mortality (HR 1.16; P = .62; 0.64-2.11). In conclusion, patients with metastatic osteosarcoma and limited pulmonary disease burden demonstrate comparable outcomes after thoracotomy and thoracoscopy for metastasectomy. While significant selection bias in these surgical cohorts limits the generalizability of the conclusions, clinical equipoise for a randomized clinical trial in patients with oligometastatic disease is supported.

Pancreaticoduodenectomy for the treatment of pancreatic neoplasms in children: A Pediatric Surgical Oncology Research Collaborative study.

BACKGROUND: To better characterize short-term and long-term outcomes in children with pancreatic tumors treated with pancreaticoduodenectomy (PD). METHODS: Patients 21 years of age or younger who underwent PD at Pediatric Surgical Oncology Collaborative (PSORC) hospitals between 1990 and 2017 were identified. Demographic, clinical information, and outcomes (operative complications, long-term pancreatic function, recurrence, and survival) were collected. RESULTS: Sixty-five patients from 18 institutions with a median age of 13 years (4 months-22 years) and a median (IQR) follow-up of 2.8 (4.3) years were analyzed. Solid pseudopapillary tumor of the pancreas (SPN) was the most common histology. Postoperative complications included pancreatic leak in 14% (n = 9), delayed gastric emptying in 9% (n = 6), marginal ulcer in one patient, and perioperative (30-day) death due to hepatic failure in one patient. Pancreatic insufficiency was observed in 32% (n = 21) of patients, with 23%, 3%, and 6% with exocrine, or endocrine insufficiencies, or both, respectively. Children with SPN and benign neoplasms all survived. Overall, there were 14 (22%) recurrences and 11 deaths (17%). Univariate analysis revealed non-SPN malignant tumor diagnosis, preoperative vascular involvement, intraoperative transfusion requirement, pathologic vascular invasion, positive margins, and need for neoadjuvant chemotherapy as risk factors for recurrence and poor survival. Multivariate analysis only revealed pathologic vascular invasion as a risk factor for recurrence and poor survival. CONCLUSION: This is the largest series of pediatric PD patients. PD is curative for SPN and benign neoplasms. Pancreatic insufficiency is the most common postoperative complication. Outcome is primarily associated with histology.

Prenatal prediction of survival in congenital diaphragmatic hernia: An audit of postnatal outcomes.

PURPOSE: Effective antenatal counseling in congenital diaphragmatic hernia (CDH) relies on proper measurement of prognostic indices. This quality initiative audited the accuracy of prenatal imaging with postnatal outcomes at two tertiary pediatric referral centers. METHODS: Prenatal lung-head ratio (LHR) and total fetal lung volume (TFLV) for CDH patients treated between 2006 and 2017 were retrieved. Study inclusion required at least one LHR or TFLV measurement between 24 and 32 weeks gestational age. Postnatal outcomes [mortality, extracorporeal life support (ECLS) need, patch repair, persistent pulmonary hypertension, oxygen requirement at 28 days] were abstracted from the Canadian Pediatric Surgery Network (CAPSNet) database and local chart review. Univariate and descriptive analyses were conducted. RESULTS: Eighty-two of 121 eligible CDH patients (68%) were included. Overall mortality, ECLS rates, and patch repair were 33%, 12.5%, and 45%, respectively. Lower LHR values correlated with increased rates of each outcome and persisted despite multiple measurements. Values obtained were higher than those in published schemata. LHR values >45% were most associated with survival, avoidance of ECLS, and primary repair. TFLV values only correlated with mortality and patch repair. CONCLUSIONS: This audit confirms that LHR and TFLV values predict CDH outcomes. However, absolute values obtained require careful interpretation and internal review. LEVEL OF EVIDENCE: IV.

Factors influencing the incidence of Hirschsprung associated enterocolitis (HAEC).

PURPOSE: This study aims to characterize risk factors for Hirschsprung-associated enterocolitis (HAEC). We hypothesize that earlier pull-through surgery is associated with lower risks of developing postoperative HAEC. METHODS: A comparative study of 171 Hirschsprung patients treated from 1990 to 2017 was performed. Patients without HAEC were compared to patients with preoperative and/or postoperative HAEC. Results are presented as median [IQR] or frequency (%). Pearson's χ2 test and Wilcoxon rank sum test were performed with a significance level at p < 0.05. Multivariable logistic regression analysis was used to adjust for potential confounders. A subanalysis was done to evaluate laparoscopic, laparotomy, and transanal surgeries. RESULTS: Risk of developing preoperative HAEC was significantly associated with congenital malformations (OR 2.63 [1.11, 6.24]; p = 0.02). Birth weight was lower in patients with preoperative HAEC (OR 0.48 [95% CI 0.25, 0.93]; p = 0.03). On regression analysis, intestinal obstruction after surgery was significantly associated with postoperative HAEC (OR 8.2 [3.18, 21.13]; p < 0.0001). Patients with earlier pull-through surgery did not have a lower risk of developing postoperative HAEC. CONCLUSIONS: Timing of surgery does not seem to be associated with a higher risk of developing pre- and postoperative HAEC. Predisposing factors for preoperative HAEC included associated malformations and lower birth weight, whereas intestinal obstruction was found to be associated with postoperative HAEC. TYPE OF STUDY: Treatment study. LEVEL OF EVIDENCE: Level III.