Outcomes of Management of Anal and Perianal Suppuration at Niamey National Hospital, Niger

Bakground: Anal and perianal sepsis is common anorectal disorders found in surgical practice. This study aims to report epidemiological aspects and outcomes of management of anal and perianal suppuration. Methods: This was a retrospective study from January 2011 to June 2016 at Niamey National Hospital. Patients operated on for anal and perianal suppuration of non-specific anorectal origin were included. Results: During the study period, we collected 141 cases of anal and perianal suppurations. The average age of our patients was 42±8.8 years. The sex ratio was 3.27 in favor of men. The origin of the patients was urban in 73.8% of the cases. The history of diabetes mellitus was found in 14.2% (n=20). Anal fistulas and anal abscesses (n=115) were simple in 46% (n=53) and complex in 54% (n=62). A fistulectomy with the placement of an elastic seton was performed for 41.13% of cases (n=58) and fistulotomy in 29.78%. The evolution of 6 months was marked by a recurrence in 10.63% (n = 15), the anal incontinence of gas at 9.21% (n=13). Deaths (n=4) were recorded in patients with Fournier’s gangrene. Uncomplicated therapeutic success was 80.13% (n=113). Conclusion: The surgical treatment of anal fistula (the main cause of anal and perianal suppuration) aims to eradicate the suppuration and to preserve the anal continence. The fistulotomy done in the context of the management of a simple fistula gives a better outcome. Incontinence-related complications and relapses must impose thoroughness and patience in the surgical treatment of complex fistulas.


Introduction
Anal and perianal suppuration (APS) continues to be a problem for patients and surgeons despite scientific advances in understanding their pathogenesis [1][2][3][4]. APS are very old conditions described well before 2200 BC [5,6]. Hippocrates had described (430-460 BC) the use of seton in the treatment of anal fistula [2,[5][6][7]. They affect more often the man than the woman between the 3rd and 6th decade [1][2][3][4][5][6][7][8][9]. The causes are various, but infection cases are classified as cryptoglandular origin by Hermann and Desfosses gland infection in 71 to 80% [8][9][10]. Other less common causes of APS are associated with inflammatory diseases such as Crohn's disease, infected anal fissures, pilonidal sinus, specific infections (such as tuberculosis, actinomycosis), urogenital infections, trauma and in some cases of tumors [1,7,9]. In the diagnostic and therapeutic approach, abscess and fistula are often two stages (acute and chronic) of the same disease [4,[5][6][7]. Surgical treatment of anal fistula aims to eradicating suppuration trajectory and to preserve the anal continence [5]. Diagnosed abscess should be treated urgently to prevent progression to Fournier's gangrene, especially in debilitated patients [5,10]. Although the literature is numerous wide world of APS, few studies exist in Niger. In this work, we report our experience on the epidemiological aspects and outcomes of management of anal and perianal suppuration.

Patients and Methods
This was a retrospective study during the period between January 2011 and June 2016 (5 years and 6 months) at Niamey National Hospital, Niger. Inclusion criteria were patients underwent surgery for anal and perianal suppuration of anorectal origin: anal abscesses, fistulas complicated or not with Fournier's gangrene ( Figure 1) and anal fissure. Exclusion criteria for this study were patients with nonexploitable records, non-cryptoglandular fistula (i.e specific perianal infections, malignant neoplasms, traumatic origin, fistula due to inflammatory disease), cases of Fournier gangrene of urogenital origin, and all perianal suppuration whose origin did not anorectal (pilonidal sinus, Verneuil's disease, cutaneous furuncle, herpes, suppurative hydrosadenitis). The following variables were collected: age, sex, medical history, time to admission, clinical forms, location of fistula orifices, laboratory tests, surgical treatment and evolution. Anal fistulas were classified into 2 groups according to the recommendation of the experts: on the one hand the low fistula (simple fistula) not implying the external sphincter significantly, and, on the other hand, the complex or high forms of fistula with risk of reaching sphincter during surgical treatment [5,11,12]. A sitz bath and antibiotherapy combining cephalosporins and metronidazole modified according to the antibiogram were indicated to all patients perioperatively. A follow-up to 6 months was done to evaluate the surgical outcomes. Excel and Epi-info7TM-CDC software were used to record and analyze the data collected in a survey form.

Results
During the period of study, one hundred forty-one patients with anal and perianal suppuration were collected, out of 16040 general surgery admissions (i.e. 0.87% of cases).
The average age was 42 ± 8.8 years with extremes ranging from 18 years to 86 years. The age group range to 35-54 was the most representative at 49.65%. Patients were predominantly male, 76.6% (n = 108), i.e. sex ratio of 3.27. Table 1 give the details of the age and sex of the patients. Our patients come from urban areas in 73.8% of cases (n = 104) and rural areas in 26.2% (n = 37). The admission time from the onset of symptomatology was between 3 and 30 days for 56.74% (n = 80), more than 30 days for 34.75% (n = 49), and less than 2 days for 8.5% (n = 12). The medical history was found in 37 patients including 20 cases of diabetes mellitus (14.2%), Table 2.
The anal fistula was responsible for suppuration in 71% of cases (n = 100), the anal abscess was found in 10.5% of cases (n = 15) and suppuration was complicated by Fournier's gangrene in 15% of patients (n = 21). The anal fissure was responsible for anal suppuration in 3.5% of cases (n = 5). Of the 21 complicated Fournier gangrene patients, 15 (71.14%) were diabetic mellitus and four (19.04%) were infected with HIV. Among the 100 cases of anal fistula, the external orifice of the purulent flow was unique in 57%, double in 21% and multiple in 22% of cases. The anatomical location of the external orifices distributed according to their position at the anus, in 51% of the external orifice of the fistula was posterior, 22% lateral right, in 21% lateral left and 6% anterior. In this series, in patients with anal fistula and anal abscess (n = 115), the primary orifice of the fistula was found during digital rectal examination and/or rectoscopy in 43 patients, i.e. 30.50%.
As part of the surgical treatment, 41.13% (n = 58) had fistulectomy with the placement of an elastic seton and 29.78% (n=42) of a fistulotomy. Follow up at 6 months was marked by a recurrence rate of 10.63% (n = 15). The anal gas incontinence was recorded in 9.21% (n = 13), but this complication only affected patients with complex fistulas. Deaths (n = 4) were recorded in the Fournier gangrene group. Treatment and evolution data are found in Table 3. Uncomplicated therapeutic success was recorded in 113 patients, i.e. 80.14%.
The average length of stay was 7 days with extremes of 2 to 72 days. In our sample, 53.90% of our patients had the duration of hospitalization ≤ 10 days, all pathologies combined.

Discussion
The anal and perianal suppuration (APS) constitute a group of various affections, with several etiologies [1,6,11]. APS mainly arises from anorectal abscesses and classified as cryptoglandular in origin [2,5,6]. They are rarely independent of the anorectal area (pilonidal sinus, Verneuil's disease, cutaneous furuncle, etc. [1,5]. In our study, cryptoglandular origin of APS accounted for 96.5%. According to data in the literature, infection of the Hermann and Desfosses glands is responsible for anal and perianal suppuration in 70 to 95% of cases [2,5,6,9,10]. The infection of these glands (6 to 8 in number) would lead to the formation of an intersphincteric abscess that can evolve either towards regression or towards diffusion in the intersphincteric space or through the external anal sphincter. Thus constituting the anal fistula [2,6,9]. Other less common causes of APS include anal fissure, Crohn's disease, trauma, surgery, and specific infections such as actinomycosis and tuberculosis or [1,2,5]. In this study, infected anal fissure represents only 3.5% of our patients.
The glands of Hermann and Desfosses reach the crypt level of Morgani (line of crypts) and are more numerous in men than in women [1][2][3][4][5][6][7]. In this study, men were in the majority with a sex ratio of 3.27. Several studies have reported that men are more risk to develop anal abscesses or fistula than women [2,6,9,11,12]. The sex ratio varies from 2 to more than 3 [13][14][15][16][17][18][19]. The average age of our patients was 42 years old. This is consistent with the results of Bagny et al [14] in Togo who found an average age of 41.8 years. APS are a common condition in surgical practice. The incidence of anal fistulas is approximately 1 to 28 in 10,000, occurring in 80% of patients between 30 and 50 years of age [1,2,10,13,18,19].
Anorectal abscesses complicated to Fournier's gangrene accounted for 15% of our series. This could be explained by the delay of consultation related to the modesty and the shame of the patients facing the affections of the anal/perineal parts, but also to the belief in the traditional treatment as the first resort which leads to an admission in a health facility that in case of complications. The relationship is evident between anorectal abscesses and fistulas. In patients presenting for anorectal abscesses and fistulas, perianal abscess occurred in 40-42.7%, ischiorectal in 20-22.7%, intersphincteric in 21.4% and supralevator in 7.0-7.33% of cases [6]. Most patients with fistula will have had a recognizable abscess before presentation. Roughly one third of patients with anorectal abscess will have concomitant fistula at the time of presentation [2]. In general, the clinical examination combining inspection, palpation and digital rectal examination makes it possible to diagnose low (simple) fistula. However in some cases the diagnosis of complex suprasphincteric fistulas can be difficult to require further complementary examinations [1,6]. Currently, in developed countries, when clinical examination or endorectal ultrasound are not conclusive, computed tomography scan or magnetic resonance imaging (MRI) remains the reference and effective method, the most sensitive and the most specific to explore perianal abscesses or infected fistulous tracts [1,2,[20][21][22][23]. For Siproudhis [20], nowadays, the exploration of suppuration under general anesthesia is not a reference strategy for diagnosis. However, in our context, this method of examination under general or locoregional anesthesia is still relevant and sometimes the complexity of the fistula is discovered intraoperatively.
Anorectal abscesses and anal fistula are common disorders experienced by emergency department practitioners, surgeons and infectious diseases [1,2,6,9]. In this study, anal fistula, abscess and fistula complicated by Fournier's gangrene accounted for 71%, 10.5% and 15% of our patients, respectively. Standard surgical treatment is governed by the same principles, since it involves 2 progressive stages of the same disease (abscess then fistula) [5,7]. Their management depends on the clinical picture that can be done in an emergency or in scheduled surgery. In the abscess or Fournier's gangrene stage, incision drainage/or debridement should be undertaken at emergency in order to avoid complications due to septic shock or even death of the patient [5,7,18 ]. However, for Zeitoun et al. [4], in case of emergency suppuration performed by "simple" incision, there is a substantial rate of recurrence ranging from 12 to 41%. This makes it possible to recommend the complete treatment of APS (abscess and fistula) at once. Indeed, the incision of the abscess without fistula cure leaves a scar and can lead a simple fistula to become complex [4]. However, in our study, we made a simple incision of all cases of the abscess without considering the cure of the anal fistula.
The goals of surgical treatment for patients with anal fistula are to eradicate fistula track, to drain associated sepsis, to prevent recurrence and to preserve anal sphincter integrity. This implies the preservation of sphincter function [1,2,5,6,[20][21][22][23][24][25][26][27]. For the sake of rationality and care practice, classification can be limited to high fistulas (complex fistulas) and low fistulas (simple fistulas) [20]. Thus the surgical technique will depend on low or high fistula (significantly affecting the sphincters: trans-sphincteric superior or supra-sphincteric) [1,2,5,11,12,26]. The recognition of the orifices (external and internal, of the main fistulous tract which are essential elements for its management [1-5, 20, 27]. For Parks et al. [12], "It's impossible to perform operations without accurate anatomical knowledge, and this is particularly true in the case of fistula in-ano where intemperate surgery can lead to such disastrous results. It is, therefore, most instructive to read the literature of the anatomical concepts which surgeons have held regarding this disease." In our study, fistulectomy with an elastic seton was performed in 41% of cases and the recurrence rate was 10.34%. The fistulotomy was done for 42 patients (29.78%) of our series with a recurrence rate of 4.76%. When the fistulas are simple or low, i.e. minimal involvement of the muscular sphincter (subcutaneous fistulas, interphincteric fistulas or low transsphincteric fistulas); the treatment of choice in these patients is fistulotomy with a low recurrence rate (11%) [1,2,6,5,17,22]. Fistulotomy remains the standard surgical treatment for low anal fistulas, but presents a risk of sequential continence disorders for high fistula [20,24,27]. Indeed, the success rate of this procedure ranging from 84 to 95% [18,[24][25][26][27]. On the other hand, the option of fistulectomy treatment with the placement of elastic seton (progressive elastic traction) should be considered in patients with complex fistula with significant sphincter involvement [1,2]. Fistulotomy cannot be performed at a time because of the high risk of incontinence [1,2]. "If low fistulas can be the subject of a fistulotomy without major risk, the greatest prudence is of rigor for the high, complex fistulas, which must be the subject of the fractionation of the operating times to dry up the suppuration, while trying to preserve continence at best" [5]. It will be proposed to cut the sphincter in a progressive way (flattened in several times or by elastic necking) [5,8]. Fistulectomy with elastic tightening was the technique most used in our study.
The risk of anal incontinence after surgery for an anal fistula crossing the sphincter varies from 5 to 30% according to the literature. This risk is directly related to the relationship between the fistula and the degree of involvement of the sphincter [1,5,[22][23][24][25][26][27]. In our series, the rate of gas incontinence was 9.21% of all patients with high fistulas. The functional risk having a major impact on the patient, several alternatives are currently proposed to the surgical treatment [1-3, 5, 10-13, 27]. Four techniques are the most evaluated: the anorectal advancement flap, the injection of biological glue, the placement of a plug and the interphincteric ligation of the fistulous tract [3,5,[20][21][22][23][24][25][26][27]. Some also propose a treatment by gluing for complex fistulas as well as for simple fistulas [5,27].

Conclusion
Anal fistula is the main cause of anal and perianal suppuration in this study. Surgical treatment aimed to eradicating suppuration and preserving anal continence still presents a challenge for the surgeon especially in the cases of transphincteric and suprasphincteric fistulas. The fistulotomy done in the context of the management of a simple fistula gives a better result. Fatal complications such as Fournier's gangrene can enamel the evolution of anal suppuration. But in general, these occur on fragile ground often diabetic mellitus or immunocompromised. Incontinence-related complications and recurrences must impose thoroughness in the surgical treatment of anal and perianal suppuration.

Conflicts of Interest
The authors declare that they have no competing interests.