Prediction of contralateral inguinal hernias in children: a prospective study of 357 unilateral inguinal hernias

Patent processus vaginalis: role of ultrasound in pediatric population with unilateral inguinal hernia and other predictors

INTRODUCTION

Inguinal hernia (IH) repair is a common procedure in the daily practice of pediatric surgeons. In a developing country with limited facilities, it is important to be able to predict and diagnose contralateral patent processus vaginalis (CPPV) to avoid the risk and cost of further surgery.

OBJECTIVES

To assess the accuracy of ultrasound for the detection of CPPV, using laparoscopic evaluation as a confirmatory test. We also looked for various predictors of CPPV in our study population.

METHODS

141 patients were included in this 2-year, cross-sectional prospective study. Inclusion criteria were unilateral inguinal hernia elective patients with no major comorbidities and aged between 2 months and 8 years. Each patient was assessed in outpatient clinics and then a pre-operative ultrasound was conducted. This was followed by laparoscopic evaluation during repair of the hernia.

RESULTS

Of the 141 patients included, 110 (78%) were males, 121 (85.9%) were born at full term, and 96 (68.1) had right-sided hernia. Mean age was 2.64 ± 1.9 years. Ultrasound was 85.7% sensitive in the detection of CPPV, 90.8% specific, and 90.1% accurate. In our analysis of patients younger than 1 year, right-sided hernia and defect size more than 10 mm were statistically significant predictors for a CPPV.

CONCLUSIONS

Ultrasound has a high accuracy profile and is a useful alternative in limited resource settings with restricted access to minimally invasive surgery for the prediction of CPPV. Patients younger than 1 year with a right-sided hernia or a manifested hernia defect larger than 10 mm are at a higher risk of having a CPPV.

Comparison of Laparoscopic Percutaneous Extraperitoneal Internal Ring Closure by Two-Hook Hernia Needle and Open Repair for Pediatric Inguinal Hernia

Purpose: In children, pediatric inguinal hernia (PIH) is a prevalent condition. PIH is currently more frequently managed by laparoscopic closure of the hernia sac. We improved this minimally invasive technique; that is, laparoscopic two-hook hernia needle percutaneous extraperitoneal internal ring closure. Safety and effectiveness were evaluated by comparing the differences between laparoscopic repair (LR) and open repair (OR) in terms of operation time, surgical complications, contralateral metachronous hernia incidence, and recurrence rate. Methods: A retrospective clinical data analysis was performed on pediatric patients who had hernia surgery utilizing the LR or OR method between June 2019 and June 2021. Medical records of all of the children were gathered, and clinical traits, information about the procedure, and follow-up were all analyzed. Results: A total of 370 patients' inguinal hernias were repaired. For 136 patients undergoing OR and 234 patients undergoing LR, all procedures were completed satisfactorily. There were 98 cases of bilateral hernias and 272 cases of unilateral hernias (180 on the right side and 92 on the left). In the LR group, 58 patients who had been initially diagnosed with unilateral hernias developed contralateral occult hernias intraoperatively. Inguinal hernia operations took an average of 13.82 (LR) and 32.07 (OR) minutes for unilateral cases, and 21.00 (LR) and 54.85 (OR) minutes for bilateral cases. For LR and OR, the average follow-up time was 22.41 months and 23.10 months, respectively. The perioperative complications included peritoneal rupture in 3 patients, scrotal edema or hematoma in 5, hydrocele in 3, and groin pain in 6. In the LR group, 1 patient experienced the postoperative recurrence, whereas 8 individuals in the OR group did. Conclusions: Our initial research showed that laparoscopic two-hook hernia needle percutaneous extraperitoneal internal ring closure inguinal hernia repair is a safe and effective procedure. The LR method has the benefits of concealing the incision, a quicker procedure, having a lower risk of complications, and finding contralateral patent processus vaginalis. Therefore, promoting and using this surgical technique in clinical practice are merited. Clinical Trial Registration number: Medical Association of Xiangtan (2022-xtyx-28).

Benefits of Contralateral Patent Processus Vaginalis Closure During Laparoscopic Surgery for Inguinal Hernia in Female Children

After more than a decade, an accurate description of the current state of pediatric inguinal hernia repair still an issue of contention. Improvement of techniques together with patient-entered intervention that account for the experiences related to individual disease characteristics have become an important factor of which the surgeon must be aware. Therefore, the aim of this study is to analyze a potential treatment for metachronous contralateral inguinal hernia (MCIH) in children during laparoscopic assisted percutaneous internal inguinal ring suturing (PIRS). In a prospective clinical study, carried out at the University Clinic for Pediatric Surgery in Skopje, Republic of North Macedonia, we analyzed the data from 49 female children, aged 1-14 years old, with clinically diagnosed congenital inguinal hernia treated via PIRS. The position of hernias on the right side was 29 (59.2%) on the left side was 19 (38.8%) and on both sides was 1 (2.0%). With intraoperative assessment, it was determined that in 33 (67.3%) participants there was no presence of a hidden hernia, while in 16 (32.7%), there was indeed the presence of a hidden hernia. Of the hidden hernias determined laparoscopically [16 (100%)], 8 (50%) were left and right hidden hernias, all treated laparoscopically. The PIRS technique is a procedure where the basic advanced treatment is exploration. This also included the adequate treatment of other pathologies, such as the prophylactic closure of a contralateral patent processus vaginalis with simultaneous treatment as there is the potential for hernia in future, therefore reducing the number of metachronous inguinal hernias.

Laparoscopic extraperitoneal technique versus open inguinal herniotomy in children: historical controlled intervention study

Objective

To compare surgical outcomes of percutaneous extraperitoneal simple purse string method of laparoscopic hernia (LH) repair with a traditional open inguinal hernia (OH) repair in children with indirect inguinal hernia in a single center.

Methods

This study is a historical-controlled intervention study of two groups of patients: patients in the controlled group had OH repair performed from January 2016 to December 2017, and patients in the study group had LH repair from January 2018 to December 2019 at a single institution. Outcomes of the OH and LH groups, in terms of operative time, recurrence, complications, incidence of metachronous contralateral inguinal hernia (MCIH) and contralateral patent processus vaginalis (CPPV) were analyzed.

Results

Three hundred and five patients were enrolled in the study. Among them, 95 cases underwent laparoscopic percutaneous extraperitoneal closure herniotomy (LH group), and 210 cases underwent conventional open herniotomy (OH group). In terms of operative time, only unilateral herniotomy in females of the OH group was significantly less than that of the LH group (15.7±7.1 vs 20.5±7.4 min, p=0.004). No significant difference in overall complication was observed between the two groups of patients. The incidence of CPPV in the LH group was 15.7% (15/95), and MCIH in OH group was 10.9% (23/210).

Conclusions

Laparoscopic herniotomy may prevent the need for a second operation of metachronous contralateral hernia. Both open and laparoscopic techniques are equivalent in pro and cons.

Surgical Management of Pediatric Inguinal Hernia: A Systematic Review and Guideline from the European Pediatric Surgeons' Association Evidence and Guideline Committee

INTRODUCTION

 Inguinal hernia repair represents the most common operation in childhood; however, consensus about the optimal management is lacking. Hence, recommendations for clinical practice are needed. This study assesses the available evidence and compiles recommendations on pediatric inguinal hernia.

MATERIALS AND METHODS

 The European Pediatric Surgeons' Association Evidence and Guideline Committee addressed six questions on pediatric inguinal hernia repair with the following topics: (1) open versus laparoscopic repair, (2) extraperitoneal versus transperitoneal repair, (3) contralateral exploration, (4) surgical timing, (5) anesthesia technique in preterm infants, and (6) operation urgency in girls with irreducible ovarian hernia. Systematic literature searches were performed using PubMed, MEDLINE, Embase (Ovid), and The Cochrane Library. Reviews and meta-analyses were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement.

RESULTS

 Seventy-two out of 5,173 articles were included, 27 in the meta-analyses. Laparoscopic repair shortens bilateral operation time compared with open repair. In preterm infants, hernia repair after neonatal intensive care unit (NICU)/hospital discharge is associated with less respiratory difficulties and recurrences, regional anesthesia is associated with a decrease of postoperative apnea and pain. The review regarding operation urgency for irreducible ovarian hernia gained insufficient evidence of low quality.

CONCLUSION

 Laparoscopic repair may be beneficial for children with bilateral hernia and preterm infants may benefit using regional anesthesia and postponing surgery. However, no definite superiority was found and available evidence was of moderate-to-low quality. Evidence for other topics was less conclusive. For the optimal management of inguinal hernia repair, a tailored approach is recommended taking into account the local facilities, resources, and expertise of the medical team involved.

Laparoscopic surgery: an effective and safe surgical method of pediatric inguinal hernia repair

Purpose

Inguinal hernia (IH) repair is very commonly performed in children. While open repair (OR) is the standard approach, laparoscopic repair is increasingly used. This study was aimed to investigate safety and feasibility of laparoscopic repair of pediatric IH compared to OR.

Methods

We retrospectively enrolled 105 pediatric patients with IH repair between January 2011 and October 2019. The laparoscopic procedures performed were laparoscopic percutaneous extraperitoneal closure (LPEC), and three-port mini-laparoscopic repair (TLR). The OR was performed as per usual technique.

Results

Thirty-nine patients underwent OR, 16 LPEC, and 50 TLR. The preoperative laterality of IH was 45 patients (42.9%) on the right side, 50 (47.6%) on the left side, and 10 (9.5%) on both sides. It was, however, diagnosed postoperatively in 27 patients (25.7%) on the right side, 38 (36.2%) on the left side, and 40 (38.1%) on both sides. Of the 63 patients who presented with unilateral IH in the laparoscopic groups, 32 (50.8%) had synchronous contralateral patent process vaginalis (PPV) which were simultaneously repaired. This was significantly more common in children under 3 years of age. Operative time in unilateral or bilateral repair was significantly shorter in the laparoscopic repair groups (p < 0.001). Ipsilateral recurrence was not observed in any group. Metachronous contralateral IH occurrence was not significantly different between groups.

Conclusion

Laparoscopic IH repair may have benefit in terms of shorter operation time and diagnosis of unpredicted contralateral PPV compared to OR.

Contralateral surgical exploration during inguinal hernia repair in infants (HERNIIA trial): study protocol for a multi-centre, randomised controlled trial

BACKGROUND

The incidence of metachronous contralateral inguinal hernia (MCIH) is high in infants with an inguinal hernia (5-30%), with the highest risk in infants aged 6 months or younger. MCIH is associated with the risk of incarceration and necessitates a second operation. This might be avoided by contralateral exploration during primary surgery. However, contralateral exploration may be unnecessary, leads to additional operating time and costs and may result in additional complications of surgery and anaesthesia. Thus, there is no consensus whether contralateral exploration should be performed routinely.

METHODS

The Hernia-Exploration-oR-Not-In-Infants-Analysis (HERNIIA) study is a multicentre randomised controlled trial with an economic evaluation alongside to study the (cost-)effectiveness of contralateral exploration during unilateral hernia repair. Infants aged 6 months or younger who need to undergo primary unilateral hernia repair will be randomised to contralateral exploration or no contralateral exploration (n = 378 patients). Primary endpoint is the proportion of infants that need to undergo a second operation related to inguinal hernia within 1 year after primary repair. Secondary endpoints include (a) total duration of operation(s) (including anaesthesia time) and hospital admission(s); (b) complications of anaesthesia and surgery; and (c) participants' health-related quality of life and distress and anxiety of their families, all assessed within 1 year after primary hernia repair. Statistical testing will be performed two-sided with α = .05 and according to the intention-to-treat principle. Logistic regression analysis will be performed adjusted for centre and possible confounders. The economic evaluation will be performed from a societal perspective and all relevant costs will be measured, valued and analysed.

DISCUSSION

This study evaluates the effectiveness and cost-effectiveness of contralateral surgical exploration during unilateral inguinal hernia repair in children younger than 6 months with a unilateral inguinal hernia.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03623893 . Registered on August 9, 2018 Netherlands Trial Register NL7194. Registered on July 24, 2018 Central Committee on Research Involving Human Subjects (CCMO) NL59817.029.18. Registered on July 3, 2018.

The demographic profile and the management of infantile inguinal hernia: a 3-year’s review

Background

Inguinal hernia in neonates and infants including children is as a result of failure of processes vaginalis to close. Once diagnosed, it should be promptly repaired on elective basis to prevent possible risk of bowel incarceration. The purpose of this study was to evaluate the clinical profile, management, and outcome of infantile inguinal hernia.

Methods

Aim of this prospective clinical study was to clinically evaluate the infants with clinical diagnosis of inguinal hernia admitted in our tertiary child care institute from January 2014 to December 2017 over a period of three years. The design of this study was to assess the clinical profile, management and outcome of infantile inguinal hernia. Study was conducted in a tertiary care neonatal and paediatric referral centre in southern India. Infants less than 1 year including neonates were selected for this study on the basis of inclusion and exclusion criteria. The maximum follow-up period was 5 years.

Results

A total of 118 infants admitted with clinical diagnosis of inguinal hernia were included in the present study. They were grouped as per their clinical diagnosis and age on admission into two groups; 0 to 6 months as group I and more than 6 months to 12 months as group II. All of them underwent surgical repair as soon as diagnosed. Overall survival rate was 100%. There was no operative mortality 0/118 (0%). Rate of recurrence was 0.034% without any surgical site infections.

Conclusion

Early surgical intervention in the form of inguinal herniotomy is the most appropriate management of inguinal hernia in infants including the neonates as soon as diagnosed on elective basis.

Is it worth to explore the contralateral side in unilateral childhood inguinal hernia?: A PRISMA-compliant meta-analysis

BACKGROUND

It is still not clear if the contralateral side should be explored in children with unilateral inguinal hernias. The primary aim of the present study was to assess the incidence of metachronous contralateral inguinal hernias (MCIHs) in the pediatric population. The second aim was to assess factors associated with increased risk of MCIH development.

METHODS

Prospective studies including patients from 0-19 years undergoing unilateral inguinal hernia repair without surgical exploration of the contralateral side between 1947 and April 2020 with a minimal follow-up of one year were searched. Searches included EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials.

RESULTS

Seven studies involving 1774 children (1452 boys (82%) and 322 girls (18%) were identified. Overall the incidence of MCIH was 6%. Incidence of MCIH development was significantly higher in children with initial left-sided (9%) versus right-sided (3%) hernia (OR 2.55 with 95% CI from 1.56 to 4.17; P = 0.0002), in female (8%) versus male (4%) children (OR 1.74 with 95% CI from 1.01 to 3.01; P = 0.0469) and in patients with open (14%) versus closed (3%) contralateral processus vaginalis (CPV) (OR 4.17 with 95% CI from 1.25 to 13.9; P = 0.0202). There was no significant difference in MCIH development depending on follow-up duration (follow-up of ≤2 years (i.e. 1-2 years): calculated MCIH incidence 5% (95% CI from 0.00 to 0.11%; 3 studies; 569 patients), follow-up of ≥3 years (i.e. 3-4 years): 6% (95% CI from 0.03 to 0.09; 3 studies, 983 patients)) or patients' age (MCIH incidence in children <1 year: 6.9%; older children: 4.5%; OR 1.87 with 95% CI from 0.97 to 3.62; P = 0.0618).

CONCLUSIONS

Overall incidence of MCIH development is 6%. Initial left-sided hernia, female gender and open CPV are risk factors for MCIH development.

Is contralateral inguinal exploration necessary in preterm girls undergoing inguinal hernia repair during the first months of life?

BACKGROUND

To assess the need for contralateral surgical exploration in preterm girls with symptomatic unilateral inguinal hernia.

METHODS

The medical data of girls operated for inguinal hernia between 2004 and 2016 in a single pediatric surgery center were retrospectively collected. Preterm girls operated for unilateral hernia before 6 months of life were selected (55/517 cases) to assess the incidence and risk factors for contralateral metachronous inguinal hernia (CMIH).

RESULTS

CMIH was observed in 7% of cases (4 girls with a right inguinal hernia in 3 cases) at a mean age of 4.2 years. Only one case occurred early (3 months). Birth weight and term were comparable (1674 ± 620 g and 32 ± 5 WA without CMIH vs. 1694 ± 582 g and 33 ± 3 WA with CMIH).

CONCLUSION

Contralateral inguinal hernia is very rare and generally occurs several years after inguinal repair surgery in preterm girls, which should encourage practitioners to follow these children throughout childhood for the subsequent development of inguinal hernia. This study did not find any arguments in favor of systematic contralateral exploration in preterm girls.

Surgical practice and outcome in 711 neonates and infants undergoing hernia repair in a large multicenter RCT: Secondary results from the GAS Study

BACKGROUND

The GAS study is an international RCT to evaluate neurodevelopmental outcome comparing general plus regional anesthesia versus regional anesthesia alone in 722 neonates and infants who had inguinal hernia repair up to 60 weeks of postmenstrual age. This paper comprises a secondary descriptive analysis of hernias, aspects of surgery and outcomes.

METHODS

The incidence of unilateral and bilateral hernias, side preponderance, predictive factors for bilateral hernias and surgical approaches were collated. Follow-up outcome data were examined at 2 years.

RESULTS

Of 711 eligible patients, there were 679 with hernia data showing that 321 hernias were right-sided, 190 left and 168 bilateral. Male to female ratio was 5:1. Of those with unilateral hernias, 25.8% underwent contralateral exploration and in these cases a patent processus vaginalis was found in 68.9%. Bilateral hernias were more common in younger and female patients. At 2 years there was a recurrence rate of 0.99% and in 2.7% of patients a hernia was evident on the contralateral side (metachrony), and this was unrelated to the anesthesia technique.

CONCLUSIONS

Bilateral hernias are associated with lower gestational age at birth and female gender. There was a low incidence of complications and the anesthesia technique did not affect surgical outcome.

LEVEL OF EVIDENCE

Level 1 evidence from prospective treatment study.

Pre-operative Spermatic Cord Ultrasonography Helps to Reduce the Incidence of Metachronous Inguinal Hernia in Boys

Background/purpose: Thickening of the spermatic cord is a clinical sign of an inguinal hernia. We therefore tested whether pre-operative spermatic cord ultrasonography could reduce the incidence of metachronous inguinal hernia (MIH). Methods: Boys under 2 years old with an initial unilateral inguinal hernia were enrolled in this study. In whom the width of the asymptomatic-sided spermatic cord was ≥0.5 cm, these patients underwent contralateral groin exploration. Age at initial operation, weight, initial operation side, the sonographic width of the spermatic cord, the operative findings and presence of MIH were recorded, and the relationship among them was studied. Boys in the US group underwent an open herniorrhaphy with pre-operative ultrasound examination; the non-US group included boys who did not undergo a pre-operative ultrasound examination. A receiver operator curve (ROC) analysis was performed to evaluated predictive value of the sonographic width of the spermatic cord for contralateral hernia. Results: A total of 24 months' follow-up data were obtained from 1,793 boys (US group 1,162, non-US group 631). In the US group, the width of the hernia-sided spermatic cord (0.75 ± 0.18 cm) was larger than the normal side (0.37 ± 0.05 cm, P < 0.001). And the width of normal side spermatic cord had no significant difference between the groups regarding other factors such as age and weight. In whom the width of the asymptomatic-sided spermatic cord was ≥0.5 cm, the corresponding incidence of CIH was 86.4% (57/66). The width of the spermatic cord predicted the presence of contralateral hernia with ROC area under the curve = 0.943 (95% CI = 0.919-0.966). The total incidence of MIH was 4.1% (74/1793). The incidence of MIH in the US group was 2.2% (25/1162) much lower than 7.8% (49/631) in the non-US group (P < 0.001). If the width of the asymptomatic-sided spermatic cord was 0.5 cm and 0.54 cm, the corresponding sensitivity was 0.682 and 0.294, respectively, the corresponding specificity was 0.991 and 1.000, respectively. Conclusion: If the width of the asymptomatic-sided spermatic cord of boys with initial unilateral inguinal hernia sonographic width was ≥0.5 cm, contralateral groin exploration was recommended, and it help to reduce the incidence of MIH.

Risk factors for contralateral inguinal hernia repair after unilateral inguinal hernia repair in male adult patients: analysis from a nationwide population based cohort study

Background

To identify the rate of and risk factors for contralateral inguinal hernia (CIH) after unilateral inguinal hernia repair in adult male patients.

Methods

This retrospective cohort study identified from the Taiwan National Health Insurance Research Database (NHIRD). Information on all adult patients who underwent primary unilateral inguinal hernia repair without any other operation was collected using ICD-9 diagnostic and procedure codes. The exclusion criteria were laparoscopic hernia repair, non-primary repair, complicated hernia, other combined procedures, female and undetermined gender.

Results

A total of 170,492 adult male patients were included, with a median follow-up of 87 months. The overall CIH rate was 10.5%, with a median time of 48 months to a subsequent hernia operation. The 1-year, 2-year, 3-year and 5-year-recurrent rate was 2.6, 3, 4.3, and 6.7% respectively. Further, 3.7% patients who underwent CIH repair had a complicated inguinal hernia. Multivariate analysis demonstrated that age > 45 y, direct hernia, cirrhosis (HR = 1.564), severe liver disease (HR = 1.663), prostate disease (HR = 1.178), congestive heart failure (HR = 1.138), and history of malignancy (HR = 1.116) had a significantly higher risk of CIH repair.

Conclusions

Among adult male patients undergoing long-term follow-up, we identified several significant risk factors for CIH repair. If these risk factors are presented, the surgeon should inform the following risk of CIH repair to patients so that it can be repaired as soon as possible.

Complications in common general pediatric surgery procedures

Complications related to general pediatric surgery procedures are a major concern for pediatric surgeons and their patients. Although infrequent, when they occur the consequences can lead to significant morbidity and psychosocial stress. The purpose of this article is to discuss the common complications encountered during several common pediatric general surgery procedures including inguinal hernia repair (open and laparoscopic), umbilical hernia repair, laparoscopic pyloromyotomy, and laparoscopic appendectomy.

Incidence of and Risk Factors for Pediatric Metachronous Contralateral Inguinal Hernia: Analysis of a 17-Year Nationwide Database in Taiwan

Background

Previous prospective, retrospective, and meta-analysis studies revealed that the overall incidence of metachronous contralateral inguinal hernia (MCIH) ranges from 5.76% to 7.3%, but long-term follow-up postoperative data are scant. We identified the incidence and risk factors of MCIH in pediatric patients during the follow-up using the Taiwan National Health Insurance Research Database (NHIRD).

Methods

Between 1996/01/01 and 2008/12/31, all pediatric patients with primary unilateral inguinal hernia repair who were born after 1996/01/01 were collected via ICD-9 diagnostic and procedure codes recorded in NHIRD. Patients with another operation during the same admission, complicated hernia, or laparoscopic procedure were excluded. Several reported risk factors, including age, sex, preterm birth, low body weight, and previous ventriculoperitoneal shunt placement, were used for analysis. The primary endpoint was the repairmen of MCIH following the initial surgery. All patients were followed until 2013/12/31 or withdrawal from national health insurance.

Results

A total of 31,100 pediatric patients underwent unilateral inguinal hernia repair, and 111.76 months of median follow-up data were collected. The overall rate of MCIH was 12.3%. Among the 31,100 patients who had the hernia repair, 63.6% had MCIH within 2 years and 91.5% had MCIH within 5 years. After initial surgery, the incidence of MCIH gradually and significantly decreased with age up to approximately 6 years. Multivariable analysis showed that age <4 y and girls were risk factors for subsequent MCIH.

Conclusions

After 17 years of follow-up, the overall MCIH rate was 12.3%, and 91.7% of patients needed repair for MCIH within the first 5 years after initial surgery. Age <4 years and girls were risk factors for MCIH. The contralateral exploration for inguinal hernia should be considered among these patients.

Incidence of metachronous contralateral inguinal hernias in children following unilateral repair - A meta-analysis of prospective studies

PURPOSE

The objective of this review was to systematically evaluate the incidence of a metachronous contralateral inguinal hernia (MCIH) in children with unilateral inguinal hernia and therefore to propose or to reject routine contralateral groin exploration.

METHODS

Electronic searches restricted to prospective studies with a minimal follow-up of 1year included MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials.

RESULTS

Six studies involving 1669 children were included. Overall MCIH was 6% (95% CI from 4% to 8%). The odds for MCIH development were significantly larger in children with an initial left-sided hernia (OR 2.66 with 95% CI from 1.56 to 4.53) and in children with open contralateral processus vaginalis (CPV) (OR 4.17 with 95% CI from 1.25 to 13.9).

CONCLUSIONS

The overall incidence of MCIH following unilateral inguinal hernia repair in children is 6%. Initial left-sided hernia (8.5%) and open CPV (13.8%) are risk factors for MCIH development. Female gender (8.2%) and younger age (<1year) (6.9%) non-significantly increase the risk of MCIH.