Discussion
This study evaluates the incidence of anastomotic complications in young children, which is 7% for anastomotic stenosis and 5% for anastomotic leakage. Anastomotic stenosis occurs most often in patients treated for necrotizing enterocolitis (14%), Hirschsprung’s disease (9%), or intestinal atresia (6%), which is in line with previous reports.4 Anastomotic leakages develop most often after treatment for intestinal atresia (6%) followed by treatment for necrotizing enterocolitis (5%). The evaluation of technical factors as possible predictors for the development of anastomotic stenosis shows that colonic anastomosis is associated with an increased risk of the development of stenosis compared with those located in the small intestine. Other technical factors (type of anastomosis, suture resorption time, and mode of suturing) are not significantly associated with the development of a stenosis, although e-e anastomosis shows a trend towards increased risk of stenosis. A higher ASA score (≥III) and male sex are significantly associated with the development of anastomotic leakage. In all patients undergoing a primary anastomosis, less than 1% died because of an anastomotic complication.
Compared with small intestinal anastomosis, colonic anastomoss are most at risk of stenosis development. Altough an explanation cannot be retrieved from our data, there are multiple hypotheses provided for this effect by the literature. The simplest explanation might be that, due to fluid resorption in the colon, the increased fecal consistency also increases the chances of a stenosis in the colon to become symptomatic.14 Additionally, it could be that the healing process between the two intestinal locations differ, resulting in different anastomoses. This process of anastomotic healing is to a great extent unclear, which is why there is no clear narrative yet.9 15 However, there seem to be pathobiological differences between the small intestine and colon, such as the reaction to ischemia and reperfusion, which could reasonably have an effect on the extent of anastomotic scarring.16
None of the technical factors in the creation of an anastomosis seem to be associated with stenosis development, and therefore no recommendations can be given on this topic based on our data. However, it must be noted that e-e anastomosis shows a trend towards increased risk of stenosis, which was borderline non-significant (p=0.07) in our cohort. The diameter of the intestinal lumen is smaller in an e-e anastomosisthan in a s-s anastomosis. As the anastomosis heals and the patients grow, the lumen of an e-e anastomosis might more easily get obstructed, which might explain these results.
Previous studies have suggested that stenosis following Hirschsprung’s disease treatment could be prevented by routine dilatations during the first week postsurgery, although conflicting results on this method have been reported.17 18
There is no consensus on how long the follow-up should be when conducting research into anastomotic stenosis in infants. The median time from operation to anastomotic stenosis was 44 days in our cohort; however, stenosis developed both within 10 days and up to 6 years after surgery. In our cohort, 80% of the stenoses developed within 1 year and 90% within 2 years. For this reason, 2 years seems to be an acceptable cut-off as not to miss a significant amount of stenosis.
An anastomotic leakage is a feared and unpredictable complication due to the possible severe consequences. The most feared consequence of anastomotic leakage, mortality, occurred in two children in our cohort, which is less than 1%. These fatalities show that when an anastomotic leakage occurs in vulnerable patients with multiple comorbidities, the chances of mortality are high. However, if a leakage occurs in patients who are fit enough to undergo redo-surgery, most recover. Moreover, half of the patients with a leakage recover without an enterostomy.
Enterostomy formation does not prevent complications, as previously described.5–7 Because of the associated complications of enterostomy formation, both short-term (eg, high-output stoma, stoma prolapse, and wound infections) and long-term (eg, adhesive obstructions, incisional hernia, and anastomotic stenosis), a primary anastomosis must be preferred.5 6 19 Because of these risks of enterostomy and the relatively low incidence of anastomotic leakage, one could argue that it is unwise to decide on enterostomy creation in all patients with high-risk diseases (ie, necrotizing enterocolitis and intestinal atresia patients). Identifying patient-related factors of those patients who are at increased risk of the development of anastomotic leakage could better help surgeons in the decision when not to perform a primary anastomosis. Although one should look for these factors within high-risk diseases, we feel that the decision of treatment should not solely be based on type of disease. This is underlined by our results showing ASA score to be of more importance than type of disease. An ASA score of ≥III was significantly associated with the development of anastomotic leakage in our cohort, as is the case in adults.8 In necrotizing enterocolitis, none of the 12 patients with a low ASA score (I or II) developed a leakage following primary anastomosis, while 2 out of 2 patients with an incarcerated inguinal hernia warranting resection of the incarcerated intestine with primary anastomosis with an ASA score of III developed an anastomotic leakage. The ASA score seems to reflect disease severity preoperatively and thereby possibly healing capacity of the anastomosis postoperatively.
Regarding the ASA score, male sex seems to be associated with the occurrence of anastomotic leakage. Out of 15 patients who developed a leakage in high-risk diseases (necrotizing enterocolitis, Hirschsprung’s disease, and intestinal atresia), only 1 patient was female. Our results do not provide any insights on an explanation for this finding. The increased risk of anastomotic leakage related to gender is not fully clear; however, it seems that female patients are better resistant to the damage occurring from ischemia–reperfusion-induced intestinal injury that occurs during surgery.20 Patients with Hirschsprung’s disease, which occurs predominantly in male subjects, only reported three leakages in our cohort, altough these patients made up 14% of our total cohort.21 If male sex is of key importance, we would have expected more leakages in this group. This suggests that other factors should be of importance.21 Nevertheless, the factor gender seems of influence and, in combination with other factors such as ASA score, might be informative when deciding on type of treatment.
Previous studies describe fewer complications, leakages, and stenosis, in stapled anastomosis than in sutured anastomosis in young children.22 23 These studies retrospectively included a diverse set of diseases including intestinal atresias, intussusception and necrotizing enterocolitis. In our cohort, the majority of the stapled anastomoses was created as part of pouch formation in the treatment of Hirschsprung’s disease, altough some patients with intestinal atresia also underwent a stapled anastomosis. Although this is a selective group of patients and type of anastomosis, making comparison with the rest of the cohort difficult, no stenosis or leakages developed following these stapled anastomoses.
Due to the retrospective nature of our analysis, we were limited to perioperative factors described in the patient’s files. Possibly other perioperative factors such as intestinal size discrepancy, infectious state of the patient, or (faecal) peritonitis could influence the healing process of the anastomosis and thereby the occurrence of anastomotic stenosis and leakage.24 Moreover, the small number of anastomotic complications, especially for anastomotic stenosis, might have increased the chances of type II errors. Another result of the small number of cases was that we were unable to perform regression analysis on the outcome of anastomotic leakage. Therefore, we are unable to determine the strength of the association of male sex and high ASA score with the development of a leakage.
Nevertheless, owing to our large cohort of young children undergoing a primary anastomosis, we were able to determine that anastomotic stenosis seem to occur more often in colonic anastomosis, and occurrence does not seem to be related to other technical features of anastomotic creation (other types of anastomosis, suture resorption time, or mode of suturing). The occurrence of anastomotic leakage is associated with ASA score of ≥III and male gender. Identifying more patient specific factors can result in better treatment selection, which should not solely be based on type of disease.