Draining an anal abscess: the skeletal muscle rule

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.

Fistula development after anal abscess drainage-a multicentre retrospective cohort study

PURPOSE

Anal abscesses are common and, despite correct treatment with surgical drainage, carry the risk of developing fistulas. Studies identifying risk factors for the development of anal fistulas are sparse. This study aimed to identify the risk factors for anal fistulas after anal abscess surgery.

METHODS

This was a multicentre, retrospective cohort study of patients undergoing acute surgery for anal abscesses in the Capital Region of Denmark between 2018 and 2019. The patients were identified using ICD-10 codes for anal abscesses. Predefined clinicopathological factors and postoperative courses were extracted from patient records.

RESULTS

A total of 475 patients were included. At a median follow-up time of 1108 days (IQR 946-1320 days) following surgery, 164 (33.7%) patients were diagnosed with an anal fistula. Risk factors for developing fistulas were low intersphincteric (OR 2.77, 95CI 1.50-5.06) and ischioanal (OR 2.48, 95CI 1.36-4.47) abscesses, Crohn's disease (OR 5.96, 95CI 2.33-17.2), a history of recurrent anal abscesses (OR 4.14, 95CI 2.47-7.01) or repeat surgery (OR 5.96, 95CI 2.33-17.2), E. coli-positive pus cultures (OR 4.06, 1.56-11.4) or preoperative C-reactive protein (CRP) of more than 100 mg/L (OR 3.21, 95CI 1.57-6.71).

CONCLUSION

Several significant clinical risk factors were associated with fistula development following anal abscess surgery. These findings are clinically relevant and could influence the selection of patients for specialised follow-up, facilitate expedited diagnosis, and potentially prevent unnecessarily long treatment courses.

Acute supralevator abscess: the little we know

INTRODUCTION

Acute supralevator abscess (SLA) is an uncommon and complicated form of anorectal sepsis. Its correct management is crucial to avoid complex iatrogenic fistula formation. A comprehensive review of the literature was conducted to determine the incidence of SLA and the surgical outcome with particular reference to the direction of drainage.

METHODS

A search of Medline, PubMed and the Cochrane Library was performed to identify all studies reporting surgical drainage of SLA.

FINDINGS

A total of 19 studies were identified, including 563 patients. The only two prospective studies reported an incidence of SLA of 10% and 3% in 68 and 100 patients, respectively, with anorectal sepsis. In 17 retrospective studies, the incidence ranged from 0% to 28%. Magnetic resonance imaging (MRI) was performed routinely in only one study. The surgical anatomical classification of the abscess was described in six studies diagnosed at surgery. The direction of surgical drainage whether 'inwards' (into the lumen) or 'outwards' (into the ischioanal fossa) was stated in only six studies. In two of these, the direction of drainage was contradictory to the recommendation made by Parks et al. Recurrent sepsis was reported in eight studies and ranged from 0% to 53%.

CONCLUSIONS

Detailed and prospective data on acute SLA are lacking. Its real incidence is unclear and it is not possible to analyse surgical outcomes conclusively according to different direction of drainage. The routine use of MRI in complicated anorectal sepsis would specify the surgical anatomy of SLA before any drainage is carried out.

Benign Anorectal Disorder Management in Low-Resource Settings

There are many benign anorectal disorders, which can make patients seek care. In low-resource settings, the incidence of those pathologies is not different from the industrialized and western world. However, an interesting difference colorectal surgeons and gastroenterologists can face is the fact that many patients do not seek help or are not aware and have little opportunities to be helped. Latin America population is estimated to be around 8% of the world population, with Brazil having the largest percentage. Infectious diseases, which were previously under control or were steadily declining, have emerged. For example, we have seen resurgence of dengue, malaria, and syphilis in pregnancy, as well as other sexually transmitted diseases that can affect the anorectal region. In this article, we will address the most common benign anorectal disorders.

[Quality indicators in the treatment of anal fistulas]

Anal fistulas are a common anorectal disease and are frequently associated with a perianal abscess. The etiology is based on a cryptoglandular infection in the intersphincteric space. Surgery remains the only definitive therapy. The primary goal of definitive fistula surgery is healing; however, success of fistula surgery is influenced by a variety of factors including the surgeon's experience, type of fistula, involvement of sphincter muscles, type of surgical procedure and patient-related factors. For the surgical treatment of a complex anal fistula, a variety of operative procedures have been described including fistulectomy with sphincterotomy, different flap procedures (e.g. mucosal flap and advancement flap) and finally so-called sphincter-preserving techniques, such as LIFT (ligation of intersphincteric fistula tract), VAAFT (video-assisted anal fistula treatment), the use of plugs of collagen or fibrin glue sealants as well as laser procedures or the clip. In the search for suitable quality indicators in anal fistula surgery there is a conflict between healing and preservation of continence. If potential quality indicators are identified the principles of anal fistula surgery must be adhered to and the appropriate selection of patients and procedures is of crucial importance to achieve high healing rates without compromising continence or inducing surgical revision due to abscesses or recurrence. Based on the available literature and guidelines, in the assessment of quality indicators considerable differences exist with respect to patient selection, etiology of anal fistulas and length of follow-up. Heterogeneity of treatment protocols lead to difficulties in a definitive assessment of which surgical treatment is the best option for complex anal fistulas.