Abstract
Background:
Non-surgical intervention has been proposed for the management of perianal abscess (PA) and fistula-in-ano (FIA), with potential benefits in terms of quality of life, wound healing, and functional outcome, although this strategy remains rare and controversial. Here, we aimed to compare the intermediate-term outcomes of non-surgical management with those of surgical incision and/or drainage.
Patients and Methods:
A study of pediatric patients with first-time PA and/or FIA was conducted retrospectively from January 2010 to December 2020. The patient population was stratified by surgical and non-surgical management. The clinical outcomes, including PA recurrence, FIA formation, and wound healing time, were compared between the surgical and non-surgical management groups.
Results:
A total of 457 patients managed for first-time PA and/or FIA were eligible for the current study. Of these patients, 169 (50.9%) patients received non-surgical intervention. There were no differences in terms of age, gender distribution, wound healing course, or abscess size between the two groups. Furthermore, no difference was noted between the two groups in terms of PA recurrence and/or FIA development rates and revisits for additional treatment.
Conclusions:
Although PA/FIA management is still controversial, non-surgical intervention exhibited promising outcomes for most cases of first-time PA/FIA, with fewer hospital admissions and surgical procedures and similar recurrence and fistula formation incidences. Immediate surgical intervention might be avoided because PA/FIA has a chance for spontaneous resolution in children.
Perianal abscess (PA) and fistula-in-ano (FIA) are common anorectal disorders, with an estimated incidence of 0.5%–4.3% in daily practice among infant patients [1,2]. Most cases occur in children younger than one year old, with a strong male predominance. Perianal and FIA in these periods are likely of congenital origin, which is different from the pathogenesis of these conditions in adults. Abnormal crypts of Morgagni have been implicated in PA in children and may predispose them to infection and abscess formation [3,4].
At present, the management for PA and FIA in infants is still controversial, and various methods are applied, including local care, antibiotic administration, immediate surgical drainage, or incision [2–6]. In adults, it has been suggested that surgical incision should be recommended, although needle aspiration with antibiotic therapy has been proposed. In select infants, PA is amenable to conservative management [7,8]. Although some authors support surgical incision and drainage as a standard treatment for PAs, others advocate for non-surgical management with sitz baths for spontaneous drainage [9]. Surgical incisions are usually related to post-operative discomfort and pain, leading to prolonged wound healing compared with conservative management. Subsequent fistulas occurred in approximately one-third of patients managed surgically, although this incidence is lower than that after conservative management. These findings, especially the high incidence of recurrence, support the advantages of non-surgical management [9–11].
Non-surgical management of PA has been proposed recently in the pediatric population [9] and can be performed as outpatient management with minimal discomfort. However, this approach has only been spuriously investigated and has not gained wide acceptance. In our institute, we observed a need for a minimally invasive approach based largely on the present literature. In 2016, we performed non-surgical management according to the condition of the patients, including needle aspiration as management for acute PA.
The current study aimed to assess whether non-surgical management would result in beneficial outcomes compared to standard surgical incision and drainage in terms of abscess recurrence, fistula formation, wound healing, etc.
Patients and Methods
Patient population
A retrospective review of the records of patient with confirmed PA and/or FIA for the first time from January 2004 to March 2020 was performed in our general surgical department after approval from the Institutional Review Board of Chongqing Children's Hospital, Chongqing Medical University. Perianal abscess was confirmed by liquefaction under point-of-care ultrasonography (POCUS) evaluation and a tender mass near the anus. Eligible patients were children (<1 year) who first presented with an acute perianal abscess. There were no underlying illnesses. The exclusion criteria were prior use of antibiotic agents or recurrent perianal abscess/perianal fistula within the last six months.
Protocol implementation
In clinical practice, we usually implement empirical management with corresponding pre-operative evaluations and management at the personal discretion of the physician for patients with PA and/or FIA. Before 2016, the perianal abscess was usually drained by deroofing the abscess. In some cases, the abscess was subjected to incision at the greatest fluctuance, radial curettage and irrigation of the cavity, and the wound was left for secondary healing. The fistula was usually explored with a fine probe within the abscess cavity. The fistulous tract was laid open if the fistula was identified. All the above procedures were performed in the operating room under anesthesia. The patients were then instructed to take sitz baths with a solution of 1% ethacridine for five minutes once or twice a day or practice common hygiene until the wound heals. From 2016 onward, we modified these criteria with an initially non-surgical approach, including needle aspiration of the pus, sitz bath with antiseptic solutions, or spontaneous abscess perforation through the perianal skin. At the same time, an antibiotic was administered, including intravenous amoxicillin/clavulanic acid (25 mg/kg every 8 hours) for three to five days followed by oral amoxicillin/clavulanic acid (40 mg/kg per day) for two to three days.
Data collection and definitions
Two management subsets were assigned as follows: surgical intervention and non-surgical intervention. Surgical intervention was defined as management under anesthesia in the operating room, including deroofing the abscess and radial incision following drainage. Non-surgical intervention was defined as management without anesthesia, such as sitz bath, spontaneous perforation, or needle aspiration.
The patients were assigned to either the surgical intervention or non-surgical intervention group. The patient variables assessed included baseline data, such as patient demographics (age, gender), and symptom duration. Pre-operative data were collected, such as the abscess size (centimeter) measured by ultrasonography and the presence of fistula. Failed non-surgical intervention was defined as progression of an inflammatory process during treatment accompanied by discomfort. Recurrence was regarded as an abscess that did not heal over two months or an abscess recurring in the same position.
Follow-up assessments were performed at outpatient visits, including for wound healing, fistula formation, or recurrence status. The primary measure was abscess recurrence or fistula formation within a one-year period. The secondary outcome measures (within a one-year period) were wound healing time (epithelialized wound) and hospital admission rate.
Statistical analysis
The data were processed for statistical analysis with SPSS Statistics, version 26 (IBM Corp, Armonk, NY). Categorical data are expressed as frequencies (percentages) and were tested using Fisher exact test or χ2 test as appropriate. Continuous variables are presented as the means (standard deviation) for normally distributed variables and medians (interquartile ranges) for non-normally distributed variables and were tested with the Wilcoxon rank-sum test and Student t-test, respectively. In all cases, p < 0.05 was deemed statistically significant.
Results
Overall characteristics
Overall, 836 patients were admitted for first-time PA and/or FIA, and 476 patients who underwent at least 12 months of follow-up were confirmed for eligibility and initially included in this research. Nineteen cases were considered failed non-surgical intervention and were excluded, leaving 288 patients in the surgical intervention group and 189 patients in the non-surgical intervention group. The baseline features are detailed in Table 1. The gender and age distributions were similar between the two groups, with a remarkable male predominance. There were no major differences with respect to pre-operative ultrasound presentation (p = 0.36) or abscess location. Pus samples were obtained in 329 (72.0%; 329/457) patients, with bacterial growth in 213 samples (64.7%; 213/329). There was no statistically significant difference between the two groups. Of the pus cultures that yielded growth, the most frequent bacteria was Escherichia coli, followed by Klebsiella, Staphylococcus aureus, Enterococcus, and Proteus.
Baseline Characteristics in Children with Bile Leakage after Roux-en-Y Hepaticojejunostomy
SD = standard deviation.
Management outcomes
After the non-surgical approach was adopted, the number of surgical interventions and hospital admissions decreased substantially. In terms of abscess recurrence, most abscesses occurred within the five months after management in both groups (Fig. 2). Of the 457 patients analyzed, one to three recurrent episodes of PA/FIA were found to account for 29.6% of the non-surgical intervention group and 23.6% of the surgical intervention group, without a significant difference between groups. The median wound healing course was nine (6–42) and eight (5–26) days in the non-surgical intervention and surgical intervention groups, respectively, and no difference was observed between the two groups. A similar finding for the mean length of care in the community by primary care physicians was revealed. During follow-up, the total rate of revisits for additional treatment for surgical or medical complications was 36.7% in the non-surgical management group and 29.5% in the surgical management group (p = 0.44). Although most of the 147 recurrences of PA/FIA needed surgical intervention (fistulotomy/fistulectomy), 27 cases resolved spontaneously, without a difference between the two groups.
Discussion
This research investigated a cohort of patients who presented at our institute with first-time PA and/or FIA. PA and FIA are considered the same pathologic conditions, and we reviewed them together in the current patients without distinction between PAs and FIAs. We revealed that the non-surgical management of PA and/or FIA exhibited promising outcomes regarding recurrence and reductions in operation rate in comparison with surgical intervention.
The optimal treatment for PA and FIA during childhood has generated controversy, and available options include a wide spectrum of management approaches, from conservative to surgical interventions. There is still no reported consensus for selecting between operative and nonoperative management, particularly for infants with PA and FIA [12,13]. Although there are debates about the management of pediatric PA, surgeons prefer surgical procedures, such as incision, drainage or fistulotomy [14]. Prior to 2016, the initial management of patients with PA or FIA was excessive surgical exploration as well as concurrent fistulotomy, following sitz baths for wound care.
The surgical management of PA or FIA varies in different institutes, which may lead to different disease courses. As for the surgical strategy at the time of the incision, the need for exploration of the fistula and treatment method remain controversial [15]. In an attempt to reduce PA recurrence and FIA development, active probing of the abscess for fistulotomy for first-time perianal abscess was adopted for some patients, who achieved recurrence rates ranging from 0% to 9% [16]. However other research found similar recurrence rates between drainage alone and fistulotomy at the initial operation in a cohort of 91 patients [17]. Furthermore, probing the abscess might result in iatrogenic fistula or incontinence. In this management approach, the patients were subjected to general anesthesia and thus were at risk for the complications of general anesthesia.
In light of the above points, non-operative management of PAs was proposed, including spontaneous drainage of the abscess, needle aspiration, hygiene practices, sitz baths, and antibiotic agents. Furthermore, this approach accelerates wound healing and alleviates the pain caused by abscess expansion. Moreover, non-operative management has been confirmed to be effective with a low recurrence rate in more than 80% of asymptomatic infants [18,19]. In the current series, non-operative management did not result in a higher recurrence rate or fistula formation rate (29.6% vs. 23.6%). Moreover, it is reasonable to adopt the non-operative approach because a great reduction in PA frequency was observed after two years [14].
Outcome Characteristics in Comparison between Pre- and Post-Protocol Cohorts
In our department, PA and/or FIA management has evolved, and the non-operative strategy has been preferred following its introduction. Indeed, the non-operative strategy was adopted in our surgical department gradually as the management of choice, with a gradual limitation on the indications for operation. We preferred local treatment for resolution and/or spontaneous perforation drainage of the abscess during the early stage and needle aspiration for progressive PA managed in the outpatient clinic. We also prefer non-operative treatment for patients with FIA for one or three months and performed fistulectomy for persistent FIA.
Another benefit of non-operative management is the avoidance of anesthesia, which is a concern for many parents. A previous report suggested that the patients' parents usually desired a non-operative approach such as local wound care to avoid anesthesia, although surgical intervention was initially recommended [19]. Rosen et al. [18] claimed that surgical abscess drainage and antibiotic usage are ineffective unless the patient has septic manifestations and/or uncomfortable fistulectomy during the initial operation did not reduce the recurrence rate of pediatric PA. We expected a higher chance of spontaneous healing for PA and/or FIAs because of the safer and more effective approach, and the shortest clinical course was observed in patients with spontaneous abscess perforation without complications, especially among infant patients.
Previous research suggested that the natural course of PA and FIA in infants might be time-limited spontaneous recovery in the first year of life [20], although another study supported the surgical management for PA/FIA in patients aged younger than two years, which led to shorter periods of antibiotic use and hospital stays [21]. In our series, most patients treated conservatively for perianal abscesses healed without developing FIA, and a considerable number of FIAs resolved spontaneously. Furthermore, the wound healing time of the nonsurgical treatment patients was shorter than that for patients who underwent initial surgical management, in agreement with the reports of others. Thus, early surgical management and probing of PA seems to be excessive. Here, in this study, after the one-year follow-up, both management strategies led to satisfactory outcomes, with a 99% wound healing rate. Of course, a larger cohort prospective study should be conducted to validate the current results.
Nonetheless, the current study supports the current pediatric literature in terms of nonsurgical management.
This research has several limitations. First, the short follow-up period and the retrospective nature may restrict the credibility of the current results. Another shortcoming is that the management strategy was decided based on each surgeon's preference and judgment under everyday emergency conditions, and no protocol for management selection was consistently executed, resulting in heterogeneity in daily clinical and surgical practice.
Conclusions
In conclusion, the current study provides sufficient evidence that immediate surgical intervention should be avoided whenever possible for the first-time pediatric PA and/or FIA. The non-operative approach should be initially selected for first-time pediatric perianal abscesses to achieve maximal patient comfort without increasing the rates pf PA recurrence or FIA formation. However, further controlled randomized prospective research is needed to evaluate the advantages and disadvantages of the non-surgical approach for PA and/or FIA.
Footnotes
Acknowledgments
We thank Dr. Siqi Yang for providing technical assistance and for insightful discussions during the preparation of the manuscript and Dr. Xiaoyong Zhang at the Wistar Institute for help with the linguistic revision of the manuscript.
Data Availability
The dataset analyzed during the current study are available from the corresponding author on reasonable request.
Funding Information
This study was supported by grants from the National Natural Science Foundation of China (Nos. 30973440 and 30770950) in the design of the study; the Key Project of the Chongqing Natural Science Foundation (CSTC, 2008BA0021, cstc2012jjA0155) for collection, analysis, and interpretation of data; and the Chongqing Health Planning Commission of Research Fund (No. 2016MSXM044) in writing the manuscript.
Author Disclosure Statement
No potential conflicts of interest relevant to this article are reported.