Relationship Between Body Mass Index and Recurrence/Anal Fistula Formation Following Initial Operation for Anorectal Abscess

Proposal for a new classification of anorectal abscesses based on clinical characteristics and postoperative recurrence

BACKGROUND

Current surgical procedures for anorectal abscesses, including incision and drainage alone or combined concurrent fistulotomy, remain controversial primarily due to the unpredictability of postoperative recurrence or the progression to anal fistula.

AIM

To evaluate factors that predict postoperative recurrence of anorectal abscesses and propose a new classification to guide surgical procedures.

METHODS

In this retrospective study, 525 patients with anorectal abscesses treated by incision and drainage alone, at a tertiary general hospital from August 2012 to July 2022, were included. A new classification for anorectal abscesses based on their propensity to develop into fistulas, considering 18 other potential risk factors, was established. These factors, from electronic medical records, were screened for significance using the χ² test and subsequently analyzed with multivariate logistic regression to evaluate their relationship with postoperative recurrence of anorectal abscesses.

RESULTS

One year post-follow-up, the overall recurrence rate was 39%:81.0% and 23.5% for fistula-prone and non-fistula-prone abscesses, respectively. Univariate χ² analysis showed significant differences in recurrence rates based on anatomical classifications and pus culture results (P < 0.05). Fistula-prone abscess, ≥ 7 days between symptom onset and surgery, chronic diarrhea, preoperative antibiotic use, and local anesthesia were risk factors for recurrence, while diabetes mellitus was protective (P < 0.05). Moreover, fistula-prone abscess [odds ratio (OR) = 7.651, 95%CI: 4.049–14.458, P < 0.001], ≥ 7 days from symptom onset to surgery (OR = 2.137, 95%CI: 1.090–4.190, P = 0.027), chronic diarrhea (OR = 2.508, 95%CI: 1.216–5.173, P = 0.013), and local anesthesia (OR = 2.308, 95%CI: 1.313–4.059, P = 0.004) were independent risk factors for postoperative anorectal abscess recurrence using multivariate logistic regression. Body mass index ≥ 28 (OR = 2.935, 95%CI: 1.203–7.165, P = 0.018) was an independent risk factor for postoperative recurrence of non-fistula-prone abscess.

CONCLUSION

The choice of surgical procedure for treating anorectal abscesses should follow this new classification. Prompt and thorough incision and drainage can significantly reduce postoperative recurrence.

Anorectal Abscess

Anorectal abscesses are a common colorectal emergency. The hallmark of treatment is obtaining source control while avoiding injury to the underlying sphincter complex. Understanding the anatomy of an anorectal abscess is critical to planning the appropriate drainage strategy and decreasing the risk of complex fistula formation. Use of antibiotics should be reserved for those with extensive cellulitis, signs of systemic infection, or patients who are immunocompromised. Whether antibiotics prevent future fistula formation is an area of active research. Primary fistulotomy at time of the index drainage is controversial; however, there may be situations where it is appropriate. It is important to counsel patients that after effective drainage of an anorectal abscess, they have a 30 to 50% chance of developing an anal fistula that will then require further treatment.

Causal relationship between body mass index and anal fistula: a two-sample Mendelian randomization study

Background

Significant evidence has been documented regarding the intricate connection between the development of anal fistula (AF) and the composition of Body Mass Index (BMI). Nevertheless, due to the inherent limitations of reverse causality and confounders inherent in observational studies, this relationship remains unclarified. Our study aims to reveal the causal impact between BMI and AF, as well as identify its associated risk factors, thereby providing a more comprehensive understanding of this complex interaction.

Methods

Single nucleotide polymorphisms (SNPs) identified through genome-wide association study (GWAS) databases were used as instrumental variables for analysis. BMI served as the exposure variable, with six pooled GWAS datasets included. AF was the outcome variable. The Inverse Variance Weighted (IVW) method was used as the primary analytical technique, with MR-Egger regression, Weighted Median (WME) estimation, and Multiplicity Residual Sum and Outlier (MR-PRESSO) tests serving as secondary validations of the IVW results. Odds ratios (OR) were utilized as indicators to evaluate the causal relationship between BMI and AF.

Results

A total of 738 SNPs strongly associated with the exposure were identified as instrumental variables. The IVW results demonstrated a positive correlation between BMI and the risk of AF. The MR-Egger analysis yielded p-values greater than 0.05, indicating no pleiotropic effects among the selected SNPs. Cochran's Q test also resulted in p-values greater than 0.05, suggesting no significant heterogeneity among the instrumental variables. The MR-PRESSO analysis revealed no horizontal pleiotropy or outliers potentially violating the causal assumption (p > 0.05).

Conclusion

High BMI is positively associated with the risk of AF, and correcting BMI levels may have a preventive effect on the incidence of AF.

Causal relationship between obesity and anorectal abscess: a Mendelian randomization study

Background

Observational studies have indicated that obesity is a risk factor for anorectal abscess (ARB). However, it remains unclear whether a causal genetic relationship exists between obesity and ARB.

Methods

Univariate and multivariate Mendelian randomization (MR) were conducted using data from a large, published genome-wide association study (GWAS) of European ancestry to infer a causal relationship between obesity and ARB. Inverse variance weighted (IVW) analysis served as the primary analysis method, with results reported as odds ratios (OR).

Results

MR analysis revealed that body mass index (BMI) positively affects ARB (OR 1.974, 95% confidence interval (CI) 1.548-2.519, p = 4.34 × 10-8). The weighted median method (OR = 1.879, 95% CI 1.248-2.829, p = 0.002) and Bayesian model averaging (BMA) (OR = 1.88, 95% CI 1.477-2.392, p = 2.85 × 10-7) also demonstrated consistent results. Subsequently, the impact of several obesity-related characteristics on ARB was assessed. Body fat percentage (BF), whole body fat mass (FM), waist circumference (WC), and hip circumference (HC) were found to be causally associated with an increased risk of ARB. However, these associations vanished after adjusting for BMI effects.

Conclusion

The study confirms a positive causal effect of obesity on ARB, highlighting that reasonable weight control is an important strategy to reduce the incidence of ARB.

Anal Cryptoglandular Suppuration: Evidence-Based Management

Anal suppurative processes are commonly encountered in surgical practice. While the initial therapeutic intervention is philosophically straightforward (incision and drainage), drainage of the appropriate space and treatment of the subsequent fistula in ano require a thorough understanding of perianal anatomy and nuanced decision making. Balancing the risk of fecal incontinence with simple fistulotomy versus the higher risk of fistula recurrence with all sphincter-sparing fistula treatments can be a challenge for surgeons and patients alike.

Efficacy and safety of traditional Chinese medicine external washing in the treatment of postoperative wound of diabetes complicated with anal fistula: Study protocol of a randomized, double-blind, placebo-controlled, multi-center clinical trial

Introduction: Anal fistula is one of the commonest ailments seen by anorectal surgeons as surgery is currently the preferred treatment for it. Diabetes mellitus is a risk factor that can lead to slow wound healing after anal fistula surgery. Because of the large postoperative wound surface of anal fistula, patients with diabetes can have an increased probability of wound infection, which makes it hard to heal. There is an extensive clinical experience for wound healing in traditional Chinese medicine (TCM). The Jiedu Shengji decoction (JSD) is a widely used external washing decoction in clinical practice. However, the current evidence on it is still insufficient. Therefore, we report this carefully designed clinical trial to assess the efficacy and safety of JSD in the treatment of postoperative wounds in diabetic patients with anal fistula. Methods and analysis: This study was designed to be a randomized, double-blind, placebo-controlled, multi-center clinical trial. There were 60 eligible participants who were randomized at a 1:1 ratio to the intervention and placebo groups. Both groups received the same standard treatment. The intervention group was given external washing decoction of TCM (JSD), while the placebo group was given the placebo made of excipients and flavoring agents. The main outcome measures include wound healing, distribution of wound pathogens, levels of inflammatory mediators, and blood glucose. The secondary outcome measures included lipids, the quality of the life evaluation scale (Short-Form Health Survey 36). Assessments were performed before the start of the study, at 1st, 2nd, 3rd, and 4th weeks after the intervention, and at 8th, 12th, and 16th follow-up weeks. Discussion: The clinical study we proposed will be the first randomized, double-blind, placebo-controlled, multi-center clinical trial study to assess the efficacy and safety of TCM external washing (JSD) in the treatment of postoperative wounds in diabetic patients with anal fistula. Ethics and dissemination: The Medical Ethics Committee of Hospital of Chengdu University of Traditional Chinese Medicine has reviewed this study protocol and gave its approval and consent on 17 March, 2022 (Ethical Review Number: 2022KL-018).

Recurrence and incidence of fistula after urgent drainage of an anal abscess. Long-term results

INTRODUCTION

Anal abscess is the most frequent urgent proctological problem. The recurrence rate and reported incidence of fistula after drainage and debridement of an anal abscess is widely variable. The objective of this study is to analyse the long-term recurrence rate and the incidence of fistula after drainage and urgent debridement of an anal abscess.

METHODS

Retrospective observational study of a prospective cohort with anal abscess of cryptoglandular origin. All patients (n = 303) were evaluated two months and one year after the intervention. At the 5^th year, all the medical records were reviewed and a telephone call or appointment was made for an assessment if necessary. Specific antecedents of anal pathology, abscess characteristics, time and type of recurrence, presence of symptoms in the first revision and presence of clinical and/or ultrasound fistula were recorded.

RESULTS

Mean follow-up 119.7 months. Recurrence rate 48.2% (82.2% in the first year). Two hundred twenty-two ultrasounds performed. Incidence of ultrasound fistula: 70% symptomatic vs. 2.4% asymptomatic (p < 0.001). Global incidence of fistula 40.3%. The history of anal pathology and the presence of symptoms in the postoperative review significantly increase the possibility of recurrence (p < 0.001). The fistula is statistically more frequent if the abscess recurs (p < 0.001).

CONCLUSION

After drainage and debridement of an anal abscess, half of the patients relapse and 40% develop fistula especially in the first year, so longer follow-ups are not necessary. Endoanal ultrasound for the evaluation of the presence of fistula is highly questionable in the absence of signs or symptoms.

Recurrence and incidence of fistula after urgent drainage of an anal abscess. Long-term results

INTRODUCTION

Anal abscess is the most frequent urgent proctological problem. The recurrence rate and reported incidence of fistula after drainage and debridement of an anal abscess is widely variable. The objective of this study is to analyse the long-term recurrence rate and the incidence of fistula after drainage and urgent debridement of an anal abscess.

METHODS

Retrospective observational study of a prospective cohort with anal abscess of cryptoglandular origin. All patients (n = 303) were evaluated two months and one year after the intervention. At the 5th year, all the medical records were reviewed and a telephone call or appointment was made for an assessment if necessary. Specific antecedents of anal pathology, abscess characteristics, time and type of recurrence, presence of symptoms in the first revision and presence of clinical and/or ultrasound fistula were recorded.

RESULTS

Mean follow-up 119.7 months. Recurrence rate 48.2% (82.2% in the first year). Two hundred twenty-two ultrasounds performed. Incidence of ultrasound fistula: 70% symptomatic vs. 2.4% asymptomatic (p < 0.001). Global incidence of fistula 40.3%. The history of anal pathology and the presence of symptoms in the postoperative review significantly increase the possibility of recurrence (p < 0.001). The fistula is statistically more frequent if the abscess recurs (p < 0.001) CONCLUSION: After drainage and debridement of an anal abscess, half of the patients relapse and 40% develop fistula especially in the first year, so longer follow-ups are not necessary. Endoanal ultrasound for the evaluation of the presence of fistula is highly questionable in the absence of signs or symptoms.

Can the risk of anal fistula development after perianal abscess drainage be reduced?

SUMMARY OBJECTIVE Perianal abscesses are frequently seen in clinical practice, and perianal fistulas develop in 30%–50% of cases after treatment. This study investigated whether the type of dressing applied after abscess drainage is correlated with fistula development. Prevention of fistula formation would reduce both the loss of work and healthcare costs. METHODS The records of patients who underwent drainage of perianal abscesses between January 2015 and January 2018 were retrospectively reviewed. Patients with postoperative dressings changed with washing of the area in the hospital were included as Group 1. Patients with dressings changed at home and the area bathed in 10% povidone-iodine sitz bath were included as Group 2. The frequency and time of fistula formation, age, sex, cost, and workdays lost in the two groups were compared. RESULTS Between-group differences in age, sex, body mass index, and type of fistula that developed after months and 1 year of the abscess drainage were not statistically significant (p > 0.05). During follow-up, fistula development was significantly lower in Group 1 than in Group 2 (p < 0.001). The risk of perianal fistula development was significantly increased in those with a body mass index (BMI) > 30 (p = 0.004). CONCLUSIONS After perianal abscess drainage, in-hospital washing and dressing of the abscess area until abscess closure reduced the risk of perianal fistula, lost work time, and cost. The risk of perianal fistula development appeared to increase with BMI. A large, prospective study is needed for confirmation.

Formation rate of secondary anal fistula after incision and drainage of perianal Sepsis and analysis of risk factors

BACKGROUND

The choice of surgery for perianal sepsis is currently controversial. Some people advocate one-time radical surgery for perianal sepsis, while others advocate incision and drainage. The objective of this study is to observe the formation probability of secondary anal fistula after incision and drainage in patients with perianal sepsis and determine factors that contribute to secondary anal fistula after incision and drainage.

METHODS

A retrospective descriptive analysis was conducted in 288 patients with perianal sepsis who were treated with anorectal surgery in the Suzhou Hospital of Traditional Chinese Medicine from January 2016 to June 2018. The patients were followed by telephone, physical examination, and pelvic MRI examination for at least 1 year after surgery.

RESULTS

Three patients were not followed, 98 patients did not receive surgical treatment or one-time radical surgery for perianal sepsis, and 187 patients were ultimately identified for the study. Anal fistula was present in 105 patients, and the rate of formation of secondary anal fistula was 56.15%. There was no statistically significant difference in the fistula formation rate between different types of sepsis (P>0.05). And, in patients with secondary anal fistula, there was no significant correlation between the location of sepsis and the type of secondary anal fistula (P>0.05).

CONCLUSIONS

The incidence of secondary anal fistula after incision and drainage of perianal sepsis is 56.15%, which is lower than the incidence found in previous study. Young is a risk factor for secondary anal fistula after incision and drainage of perianal sepsis. There is no significant correlation between the location of sepsis and the type of secondary anal fistula. Simple incision and drainage is a suitable choice for patients with acute perianal sepsis.