Umbilical Hernia in pediatric age group is very a common finding 1. The incidence of umbilical hernia in general population varies with age, race, gestational age, and coexisting disorders. In the USA, the incidence in African-American children from birth to 1-year-old ranges from 25 58%, whereas Caucasian children in the same age group have an incidence of 2 18.5%. 2, 3
After birth, closure of the umbilical ring is the result of complex interactions of lateral body wall folding in a medial direction, fusion of the rectus abdominis muscles into the linea alba, and umbilical orifice contraction which is aided by elastic fibers from the obliterated umbilical arteries. Fibrous proliferation of surrounding lateral connective tissue plates may also help with natural closure. Failure of these closure processes results in umbilical hernia. 4
Umbilical hernia is considered a benign condition that often disappears spontaneously. Surgical repair is frequently postponed and often not performed because the complications of this condition are rare and the majority of the defects close within 3 years; more than 90% close before the child is 6 years of age. 5, 6 Although umbilical hernias in pediatric are common as stated previously, they are still poorly studied and no existing standard guidelines for their management. The reason behind this, thought to be the straightforward repair with no significant challenges and secondly, the minimal complications of watchful waiting protocol due to their nature of spontaneous resolution.
For this, we performed a review of the existing literature on spontaneous closure of umbilical hernia, complications associated with watchful waiting, and recommendations on timing of operative repair.
We performed an online literature search of ACP Journal Club, Clinical Evidence, Dynamed, Cochrane library, UpToDate, and PubMed. We targeted publications where pediatric umbilical hernias, recommendations on timing of surgical repair and natural history of spontaneous closure are addressed. Only Studies published in English were included in this review and no publication date limits were placed on the search. We excluded studies examining children older than 14 years, and umbilical hernias associated with other pathologies, medical comorbidities such as cirrhosis, renal failure or ascites, and any abdominal wall defects such as gastroschisis or omphalocele. We then summarized the results and recommendations of these studies and drawn a conclusion of their consensus.
Additionally, we performed our own single institutional retrospective study at Queen Rania Hospital for Children in Amman, Jordan. Medical records of 520 children presented to both outpatient offices and emergency department between 2007 and 2017, aged between 1 month and 14 years old were reviewed. The chief complain was painless umbilical swelling which was diagnosed by our faculties as an asymptomatic umbilical hernia. Size of the umbilical defects were not included in the study. Our goal was to identify the percentage of spontaneous closure within the first
5 years of age versus the rate of operatively repaired hernias beyond this age.
The likelihood of spontaneous closure of umbilical hernias in pediatric was reviewed in seven studies (summarized in Table-1). The overwhelming consensus from these articles was that, the majority of umbilical hernias close spontaneously without surgical intervention before the age of 5 years. The primary danger associated with observation therapy is the possibility of incarceration or strangulation. Studies have shown these complications to be quite rare, with an incidence of less than 0.2%. Also, studies found that methods like pressure dressings or other used devices to keep the hernia reduced do not enhance the closure process and may result in skin irritation and breakdown.
The reviewed studies are 5 prospective studies, 1 retrospective study, and one crosssectional observational study.
In the retrospective cohort study by Woods et al. in 1953 a two hundred and eightythree infants with umbilical hernia have been studied. In this series a frequency of an umbilical hernia of one in six infants has been recorded. The first appearance of the hernia is usually within the first few months of life and rarely after six months. 93 % of children became cured automatically in the first year of life in the absence of any strapping or truss 7.
Mack et al. in 1945 estimates based on prevalence data in a population of African children that 90% of hernias closed spontaneously and that there was a continual curve of healing from infancy to puberty 8.
A prospective study by Heifetz et al. in 1963 found 92.3% hernias over 0.5 cm in diameter closed spontaneously (40% closed with-in 1 year, 65% within 2 years, and 85% by 3 years). This study found that over the first year of life, the diameter of these comparatively large umbilical hernia defects decreased by an average of 18% per month 9.
Hall et al. examined a cross-section of 665 African-American children and found that the prevalence of umbilical hernias at age 11 was approximately half that at age 4 5, suggesting spontaneous closure later in childhood 10.
In a prospective cohort study of South African children in 1980, Blumberg et al. found that hernia prevalence steadily decreased with age, suggesting that even the majority of large hernias tend to close by in 3 4 years of life without surgery 11.
In contrast, a prospective cohort study of African American children in 1967 by Walker et al. found that although 89.1% of hernias closed spontaneously by age 6, larger hernias were less likely to close. This study reported that 95% of hernias (201/211) with a defect 1.5 cm in infancy 12.
A prospective cohort study investigated non-operative umbilical strapping as a method of treating umbilical hernias without surgery. In 2016, Yanagisawa et al. examined 89 children who underwent umbilical strapping. They found that 91% of umbilical hernias treated with adhesive strapping closed in 13 weeks regardless of the diameter of the hernia defect, gestational age, or the timing of treatment and only
2.25% of hernias recurred 13
Our retrospective study of 520 children aged between 1 month and 14 years presented between 2007 and 2017 with umbilical hernias in Queen Rania hospital for Children in Amman, Jordan resulted in that 442 were treated non-operatively and 78 children underwent straightforward surgical repair. Of the 442 cases treated conservatively, 85% closed spontaneously by 1-5 years old irrespective of the defect size upon their presentation. Majority of spontaneous closure was during the first 3 years of life. No incarceration or strangulation were identified.
The current recommendations available on literature in regards to the exact timing of surgical repair for asymptomatic pediatric umbilical hernias show no evidence for a particular management strategy. In contrast to complicated or symptomatic hernias where an immediate repair is frankly recommended.
While reviewing the literature, we found there is a strong consensus that umbilical hernias in pediatric age groups have the predisposition to close spontaneously especially during the first 3 years of life unlike hernias in adult. Our own retrospective cohort study has also the same conclusions.
This natural history of spontaneous closure of umbilical hernias in pediatric has the advantage of avoiding unnecessary operations, and complications of anesthesia and surgeries. This natural trend is also cost effective to health care facilities.
There is significant variability in author recommendations surrounding surgical repair of asymptomatic pediatric umbilical hernias. The majority of studies in this review concluded no increased risk of complication in children less than 6 years old, meanwhile anesthesia literature suggests an increased risk of neurologic and respiratory complications in children less than 6 years of age 14, 15.
The majority of manuscripts recommendation were supporting the watchful waiting over surgical repair for asymptomatic umbilical hernias in children younger than 5 years old. There was no association between size of the defect and likelihood of developing strangulation or incarceration. Although larger defects may be less likely to close and eventually require surgery, several small studies have demonstrated the possibility of spontaneous closure later in childhood.
Asymptomatic umbilical hernias in pediatric are a common pathology that encountered by most of pediatric and many general surgeons in their outpatient offices or in emergency department. Little recommendations were found in literature in regards to timing of surgical repair since the vast majority are resolved spontaneously with very minimal complications on watchful waiting strategy.
We concluded from the reviewed studies and additionally we found from our own experience based on our retrospective study we have done, that no surgical repair is indicated for asymptomatic umbilical hernias in infants and children before the age of 4-5 years irrespective of the defect size. In contrast to symptomatic or complicated hernias, an immediate measurements should be taken in place, this including an operative repair. This guidelines would be of benefits to avoid complications of surgical repair and complications from anesthesia, lessen the burden on medical staff and hospitals and, it is cost effective for health care systems.