This is a single-center study of a large number of cases to discuss the long-term prognosis of HD neonatal patients operated with TEPT. Our results support that most HD patients have favorable long-term results and that level of aganglionosis with long-segment or TCA and long postoperative hospital stay may be predictors of subnormal bowel function at long-term follow-up.
Though several different questionnaires have been used for long-term outcomes of patients with HD, only BFS questionnaire has data from the normal population [16], so we use the BFS to determine the bowel function of children. Recently, increasing studies tend to use BFS [10, 16–18], and a meta-analysis shows that pooled overall mean BFS score of three studies is 16.78 [19]. Compared with the other studies, the BFS of our group might be better. Furthermore, during our follow-up, 83.8% of the patients have a BFS higher than 17, which suggests TEPT for neonates with HD could achieve an acceptable function outcome.
Few studies have reported the influencing factors of long-term outcome. According to literature reports, poor bowel function may be associated with sex [20], associated congenital malformations and syndromes [8, 21], postoperative complications [11], and perioperative malnutrition [22]. In this study, the factors mentioned above are not independently related to the poor bowel function. Teitelbaum et al [22] consider that perioperative malnutrition have an impact on functional outcomes after pull-through. In our study, preoperative serum albumin and follow-up Z score are used to assess perioperative and follow-up nutritional status of patients, respectively, but no correlation is found between nutrition and bowel function, which is consistent with the previous study [11].
As a common complication after HD, the incidence of postoperative HAEC in our study is 9.4%. Previous studies show that patients with postoperative HAEC have a higher risk to have bowel problems such as soiling and fecal incontinence than the patients without postoperative HAEC [8, 10]. In contrast, some researchers consider that children with enterocolitis are more likely to have an excellent or good clinical outcome [23]. Interestingly, our study reveals that postoperative HAEC are not related to the bowel function.
Several reports have shown that level of aganglionosis has great impact on overall surgical outcome of HD [21, 24, 25]. Our data are in line with these findings as patients with long-segment or TCA have a poorer functional bowel outcome than patients with short-segement. Recent studies evaluating long-term prognosis usually do not include long-segment HD [8, 11, 13]. Our study further confirms the difference in bowel function between long-segment and short-segment HD, which suggests that we should attach importance to the effect of the level of aganglionosis on long-term outcome.
It has been revealed that TEPT is efficacious and safe in the management of HD patients, with the advantages of small incision, short hospital stay, and rapid recovery [4, 26, 27]. During our study, the discharge criteria were that the patients reached normal oral feeding without complications. Our results showed that media of postoperative hospital stay was 7 days, which was similar to previous study [28]. In addition, the multivariate logistic regression analysis showed that postoperative hospital stay > 8.5 days was an independent risk factor of subnormal bowel function. We suspect that long postoperative hospital stay may be associated with complex clinical courses, postoperative complications, and feeding difficulties. Since the postoperative hospital stay may be affected by some potential factors, it is necessary to conduct a prospective multicenter study in the future to further identify potential factors affecting long-term prognosis.
There is still conflicting evidence on whether age at follow up is associated with bowel function. Some pediatric surgeons consider that bowel function improves over time in HD patients [8, 10], but a study indicates that increasing age is a significant predictor of poor functional outcome [16]. Furthermore, a longitudinal study demonstrates that bowel function are not improved with increasing age [9]. Although our results show that age at assessment is not a predictor of subnormal bowel function, we believe that continuous follow-up and management is essential for HD patients.
Some limitations are noted in our study. Despite the basic characteristics between the included and nonincluded group are similar, it remains unknown whether the functional outcome is different in them. In addition, our findings are based on the overall means of retrospective analysis, without taking into account other factors that may affect the outcome, including the number and experience of pediatric surgeons. A longitudinal study is needed to further examine the predictive factors in the bowel function. Lastly, the functional outcomes are determined by the questionnaire, which may be influenced by subjective factors. Further analyses, such as anorectal manometry or anal sphincter electromyography, should be performed to assess functional outcomes.