Perianal Abscess and Fistula in Ano in Infancy and Childhood: A Clinicopathological Study

The optimal primary treatment for pediatric perianal abscess and anal fistula: A systemic review and meta-analysis

BACKGROUND

Perianal abscesses and anal fistulas are common. The principle of intention-to-treat has not been considered in previous systemic reviews. Thus, the comparison between primary and post-recurrence management was confused, and the recommendation of primary treatment is obscure. The current study aims to identify the optimal initial treatment for pediatric patients.

METHODS

Using PRISMA guidelines, studies were identified from MEDLINE, EMBASE, PubMed, Cochrane Library, and Google Scholar without any language or study design restriction. The inclusion criteria include original articles or articles with original data, studies of management for a perianal abscess with or without anal fistula, and patient age of <18 years. Patients with local malignancy, Crohn's disease, or other underlying predisposing conditions were excluded. Studies without analyzing recurrence, case series of <5, and irrelevant articles were excluded in the screening stage. Of the 124 screened articles, 14 articles had no full texts or detailed information. Articles written in a language other than English or Mandarin were translated by Google Translation first and confirmed with native speakers. After the eligibility process, studies that compared identified primary managements were then included in the qualitative synthesis.

RESULTS

Thirty-one studies involving 2507 pediatric patients met the inclusion criteria. The study design consisted of two prospective case series of 47 patients and retrospective cohort studies. No randomized control trials were identified. Meta-analyses for recurrence after initial management were performed with a random-effects model. Conservative treatment and drainage revealed no difference (Odds ratio [OR], 1.222; 95% Confidential interval [CI]: 0.615-2.427, p = 0.567). Conservative management had a higher risk of recurrence than surgery without statistical significance (OR 0.278, 95% CI: 0.109-0.707, p = 0.007). Compared with incision/drainage, surgery can prevent recurrence remarkably (OR 4.360, 95% CI: 1.761-10.792, p = 0.001). Subgroup analysis of different approaches within conservative treatment and operation was not performed for lacking information.

CONCLUSION

Strong recommendations cannot be made due to the lack of prospective or randomized controlled studies. However, the current study based on real primary management supports initial surgical intervention for pediatric patients with perianal abscesses and anal fistula to prevent recurrence.

LEVEL OF EVIDENCE

Type of study: Systemic review; Evidence level: Level II.

Incision and Drainage With Primary Fistulotomy of Perianal Abscess Is Safe and Effective in Neonates: A Long-Term Follow-Up Study

OBJECTIVE

Perianal abscess (PA) in neonates is poorly understood, and its management remains controversial. The aim of this study was to compare incision and drainage (ID) with or without primary fistulotomy in the management of neonatal first-time PA.

METHODS

A retrospective comparative study was conducted for neonates with first-time PA treated with incision and drainage with primary fistulotomy (IDF) vs. ID between 2008 and 2017.

RESULTS

In total, 138 patients (137 boys and 1 girl) were identified; 65 in the IDF group and 73 in the ID group. The median follow-up was 6.5 years (range 4-13 years). Baseline characteristics were similar between the 2 groups. The cure rate in the IDF group (98.5%, 64/65) was significantly higher than that in the ID group (80.8%, 59/73; p = 0.001). The rate of fistula formation in the IDF group (1.5%, 1/65) was significantly lower than that in the ID group (13.7%, 10/73; p = 0.01). The rate of abscess recurrence was not statistically different (p = 0.12), even though the IDF group (0%, 0/65) seemed to have a better outcome than the ID group (5.5%, 4/73). No fecal incontinence was observed in any of our patients.

CONCLUSIONS

First-time PA in neonates can be treated safely and effectively by the IDF or by ID alone. The former may be advantageous over the latter in terms of the rate of cure and fistula formation.

Initial Experience with Fibrin Glue Treatment of Anal Fistulae in Children

Pediatric anal fistulae commonly result from recurrent perianal abscesses, of which nearly 50 per cent develop an anal fistula. The purpose of this study was to report the results of using fibrin glue to treat anal fistula in pediatric patients. Infants and children with recurrent perianal abscesses and anal fistulae were treated with either fistulectomy or fibrin glue. Demographic and clinical characteristics and outcomes were compared between the groups. A total of 34 children were included; 27 received fistulectomy (median age eight months) and seven received fibrin glue treatment (median age 14 months). No significant differences in demographic or clinical characteristics were found between the two groups (all, P > 0.05). Median follow-up duration was significantly higher in the fibrin glue group compared with that in the fistulectomy group (five months vs one month, P = 0.003). There was one recurrence in the fistulectomy group, and no recurrences in the fibrin glue group (P = 1.0). No complications occurred in either group. Fibrin glue treatment is a simple and effective treatment alternative in the management of anal fistula in children, offering the advantage of sphincter muscle-sparing and reduced risk of fecal incontinence.

A systematic review of the management of anal fistula in infants

BACKGROUND

Fistula-in-ano (FIA) in infants differs, in several ways, from FIA in adults. The current review aims to assess FIA in infants less than 2 years old and to illustrate the outcome of different treatment modalities described in the literature.

METHODS

An organized search of the English literature over the past 25 years was conducted according to the preferred reporting items for systematic reviews and meta-analyses guidelines. Electronic databases and Google Scholar were searched for articles focusing on management of FIA in infants.

RESULTS

Fourteen studies were eligible for this review. Variables analyzed comprised patient characteristics, type of FIA, methods of treatment, recurrence, and postoperative complications. The studies included comprised total of 490 infants, 89 % of them less than 1 year old. Most patients (97.5 %) were males with a median age of 7 months. Around 20 % of patients with FIA underwent conservative treatment initially, and 73 % of them achieved complete resolution. Surgery was performed on 86 % of the infants. Fistulotomy accounted for 65 % of the procedures performed and was associated with a higher recurrence rate than fistulectomy (6.6 vs. 1.1 %, respectively). Complications of surgical management occurred in 2.6 % of the patients. FIA typically occurs in male infants, mainly under 1 year of age. Almost all fistulae in this age group are low.

CONCLUSIONS

The majority of the studies reviewed evaluated surgical treatment of FIA. However, the few studies that employed conservative treatment reported complete resolution of FIA in most infants. Fistulotomy was the most commonly performed surgery for FIA and was associated with fewer complications, yet a higher recurrence rate than fistulectomy.

Fetal growth of the anal sinus and sphincters, especially in relation to anal anomalies

PURPOSE AND METHODS

The anal sinuses, small furrows above the pectinate line, sometimes form perianal abscesses in adults. We examined the pattern of fetal growth of the anal sinus and sphincters using 22 mid-term (8-18 weeks) and 6 late-stage (30-38 weeks) fetuses.

RESULTS

In mid-term fetuses, the external and internal sphincters gradually increased in thickness, depending on specimen size (from 0.2 to 1.5 mm), whereas the anteroposterior diameter of the anal canal at the epithelial junction was relatively stable (0.5-1.0 mm) irrespective of specimen size. Anal canal diameter increased less than twofold between mid-term and late-stage fetuses, from 0.5-1.0 to almost 2 mm, whereas sphincter thickness increased over tenfold, from 0.2-1.5 to almost 3.5 mm. The anal sinus often showed balloon-like enlargement when the sphincter muscle bundles were tightly packed in mid-term, but not in late-stage fetuses.

CONCLUSIONS

Large concentric mechanical stress from the sphincters in late-stage fetuses apparently prevented the anal sinus from expanding in a balloon-like manner. Conversely, to avoid anal stenosis, the growing sinuses maintained a luminal space of the anal canal in response to stress from rapidly growing sphincters. The inferiorly extending sinus usually provided temporal double canals separated by a thick column. In the presence of double lumens, anal canal duplication is likely to develop without any abnormalities of the anal epithelium and sphincters.

Perianal abscess and fistula-in-ano in infants: a different entity?

PURPOSE

The features of perianal abscess and fistula-in-ano in infants are different from those of older children, and there is controversy regarding their treatment. The aim of this study was to assess the efficacy of various methods used for their management.

METHODS

A retrospective analysis of the records was conducted for all infants younger than 24 months of age treated for perianal abscess, fistula-in-ano, or both from 1990 to 2002.

RESULTS

The study included 98 infants. Perianal abscess was found in 77 patients (75 males), and fistula-in-ano in 21. No infant had an underlying illness. Drainage was performed by needle aspiration in 47 patients and by incision and drainage in 5. Following drainage, 43 patients received antibiotics. Altogether, 6 infants were treated with antibiotics alone and 19 with local care alone. Twenty-eight boys (36.4 percent) had an evolution toward fistula-in-ano. Patients who received antibiotics following drainage were less likely to develop fistula-in-ano than were patients who underwent a drainage procedure alone (27.9 percent vs. 66.7 percent, P < 0.05). All patients with fistula-in-ano were male and had been previously treated for perianal abscess (21 patients elsewhere and 28 in our department). Spontaneous cure of fistula-in-ano occurred in 42.9 percent of them (average 3.2 months), and 57.1 percent underwent fistulectomy for persistent fistula-in-ano. Cryptotomy was added when an involved crypt was found (11 patients, 39.3 percent). No recurrence of fistula-in-ano was noted after fistulectomy.

CONCLUSIONS

Local treatment for perianal abscess during the early stage and drainage by needle aspiration during the progressive stage are effective. Antibiotics may be considered for patients undergoing drainage of perianal abscess. Fistula-in-ano can be managed conservatively for one to three months. For a persisting fistula, fistulectomy with cryptotomy (when abnormal anal crypts are found) is the preferred treatment.