Outcomes of preoperative anal dilatation for Hirschsprung disease

Background/purpose: There are some studies about the effect of postoperative anal dilatation on anastomotic stenosis and Hirschsprung-associated enterocolitis (HAEC), but we have not seen any report about preoperative anal dilatation. We hypothesized that preoperative anal dilatation could reduce the incidence of HAEC and facilitate the operation. We aim to compare the HAEC rates and postoperative complications between groups who either had or did not have anal dilatations (AD or NAD) prescribed before laparoscopic-assisted Soave pull-through procedures for Hirschsprung disease (HD); by this means, we will evaluate the benefit of dilatations before the surgery for HD.

Methods: A retrospective review of children with HD operated in our hospital between 2014 and 2018 was performed. Those with 21 trisomy, total colonic aganglionosis, multiple stage procedures, serious congenital malformations, and lost to follow-up were excluded. Patients were divided into preoperative anal dilatation group (AD group) and no preoperative anal dilatation group (NAD group). Routine anal dilatation was performed in both groups from 2 weeks after laparoscopic-assisted Soave pull-through. The anal dilatation was carried out daily with metal anal dilators with size appropriate to the age of the child. The size of the anal dilators was increased by 1 mm every 2 weeks for at least 3 months. Demographic data, operation time, pre- and postoperative HAEC rates and postoperative obstructive symptoms between groups were compared. Significance was considered at P < 0.05.

Results: There were 95 children (17 female and 78 male) included, 36 AD and 59 NAD. There was no significant difference in demographic data between the two groups. The incidence of HAEC between the groups was not different both preoperatively (14% vs. 24%, P = 0.298) and postoperatively (11% vs. 19%, P = 0.171). The postoperative obstructive symptoms rates were 19% versus 22% for the AD and NAD groups, respectively (P = 0.802). The operation time of group AD was significantly shorter than that of group NAD (P = 0.008). Preoperative anal dilatation could shorten the operation time in short and typical-segment (2.08 ± 0.39 vs. 2.67 ± 0.37, P = 0.009 and 3.05 ± 0.38 vs. 3.29 ± 0.46, P = 0.042), but has no significant effect on long-segment disease (3.85 ± 0.41 vs. 3.89 ± 0.30, P = 0.839).

Conclusion: We have not shown a reduced risk of developing HAEC or postoperative obstructive symptoms if anal dilatations are prescribed before surgery. However, it may decrease the difficulties of surgeries, so the operative time is shortened.

Level of evidence: Prognosis study.

Level: II.