The prognostic effect of perianal abscess after surgery
Among 394 patients, there were 329 males and 65 females, aged 11–80 years old, with an average age of 39.4 ± 12.3 years; 247 cases had normal blood routine examinations before operation (147 cases of abnormally high white blood cell count); 24 cases had diabetes mellitus; 171 cases had MRI examination before operation, and 223 cases did not undergo MRI examination; 352 cases had low perianal abscesses in the abscess space, and 42 cases had high perianal abscesses; 122 cases were operated by simple incision and drainage, and 272 cases had thread-attached drainage.
The wound recovered well after the operation, with occasional itching and dampness at the wound scar recorded as cured and adverse reactions such as recurrence or formation of anal fistula recorded as uncured. According to statistics, there were 351 cases (89.08%) in the cured group, 43 cases (10.92%) in the uncured group, of which 32 cases recurred or formed anal fistula within half a year, and 11 cases recurred within 6 − 12 months.
Univariate analysis of the prognosis of perianal abscess after surgery
To investigate the factors that affect the prognosis of perianal abscess after surgery, the age, gender, preoperative blood routine, preoperative MRI, abscess gap, surgical method, and whether or not diabetes was combined in the two groups were analysed. The results are recorded in Table
1. The results showed no statistically significant difference in gender, age, and whether the two groups of patients with diabetes mellitus (p > 0.05).
Table 1
Single factor analysis of prognosis of perianal abscess after operation
> 60 | 23 (6.55%) | 3 (6.98%) | 0.11 | 0.916 |
≤ 60 | 328 (93.44%) | 40 (93.02%) |
Sex |
Male | 291 (82.90%) | 38 (88.37%) | 0.831 | 0.362 |
Female | 60 (17.09%) | 5 (11.63%) |
Smoke | | | | |
Yes | 22 (6.27%) | 3 (6.98%) | 0.032 | 0.857 |
No | 329 (93.73%) | 40 (93.02%) |
Drink | | | | |
Yes | 8 (2.28%) | 2 (4.65%) | 0.871 | 0.351 |
No | 343 (97.72%) | 41 (95.35%) |
BMI(kg/m2) | | | | |
< 28 | 330 (94.02%) | 42 (97.67%) | 0.972 | 0.324 |
≥ 28 | 21 (5.98%) | 1 (2.33%) |
Preoperative blood routine (white blood cell count) | | | | |
Normal | 226 (64.39%) | 21 (48.84%) | 3.960 | 0.047 |
Abnormal | 125 (35.61%) | 22 (51.16%) |
With diabetes |
Yes | 22 (6.27%) | 2 (4.65%) | 0.006 | 0.936 |
No | 329 (93.73%) | 41 (95.35%) |
Anatomical classification | | | | |
Perianal subcutaneous | 253 (72.08%) | 23 (53.49%) | 9.750 | 0.045 |
Pelvis | 9 (2.56%) | 3 (6.98%) |
Submucosal | 5 (1.42%) | 2 (4.65%) |
Deep retrorectal abscess | 18 (5.13%) | 5 (11.63%) |
Ischium | 66 (18.80%) | 10 (23.26%) |
Abscess space |
Low bit | 319 (90.89%) | 33 (76.74%) | 6.625 | 0.010 |
High bit | 32 (9.11%) | 10 (23.26%) |
Preoperative antibiotic use | | | | |
Yes | 51 | 8 | 0.500 | 0.480 |
No | 300 | 35 |
Horseshoe abscess | | | | |
Yes | 76 | 10 | 0.058 | 0.810 |
No | 275 | 33 |
Onset time | 8.79 ± 8.76 | 8.40 ± 7.55 | t = 0.286 | 0.775 |
Preoperative MRI |
Yes | 159 (45.30%) | 12 (27.90%) | 4.717 | 0.030 |
No | 192 (54.70%) | 31 (72.10%) |
Surgical method |
Hanging line drainage | 251 (71.51%) | 21 (48.84%) | 9.212 | 0.002 |
Simple drainage | 100 (28.49%) | 22 (51.16%) |
There were statistically significant differences between the two groups regarding whether the patient received a preoperative MRI examination, the surgical method, the preoperative blood routine, the range of abscess cavity space and the anatomical classification (p = 0.030, p = 0.002, p = 0.047, p = 0.010 and p = 0.045, respectively). The results showed that the abnormal rate of preoperative blood routine results in the uncured group (51.16%) was higher than in the cured group (35.61%); the rate of perianal subcutaneous in the cured group (72.08%) was higher than in the uncured group (53.49%); the rate of high abscess space in the uncured group (23.26%) was higher than in the cured group (9.11%); The proportion of patients in the uncured group who underwent MRI before surgery (27.90%) was lower than in the cured group (45.30%); the proportion of patients in the uncured group who underwent simple drainage (51.16%) was higher than in the cured group (28.49%).
Multivariate logistic regression analysis of prognosis of perianal abscess after operation
Based on the results of univariate analysis, multivariate logistic regression analysis was used to further determine the risk factors affecting the prognosis of perianal abscess after surgery. Whether the perianal abscess is cured after the operation is the dependent variable, and the routine blood range before the operation, MRI examination of the perineum, the range of the abscess cavity, and the operation method are the independent variables, which are included in the logistic regression analysis. The assignment is shown in Table
2. The results are shown in Table
3, the range of the abscess space (OR = 2.544, 95%CI = 1.087–5.954,
p = 0.031) and the operation method (OR = 2.180, 95%CI = 1.091–4.357,
p = 0.027) are independent influencing factors for the postoperative cure of perianal abscess.
Table 2
Assignment situation
Preoperative blood routine range | Normal = 0; Abnormal = 1 |
MRI of the perineum before surgery | No = 0; Yes = 1 |
Abdominal space range | Low bit = 0; High bit = 1 |
Surgical approach | Simple = 0; Hanging line = 1 |
Table 3
Logistic regression analysis of prognosis of perianal abscess after operation
Preoperative blood routine range | 0.494 | 0.346 | 2.037 | 0.154 | 1.639 | 0.831 − 3.233 |
MRI of the perineum before surgery | −0.520 | 0.386 | 1.812 | 0.178 | 0.595 | 0.279 − 1.267 |
Abdominal space range | 0.934 | 0.434 | 4.633 | 0.031 | 2.544 | 1.087 − 5.954 |
Surgical approach | 0.779 | 0.353 | 4.869 | 0.027 | 2.180 | 1.091 − 4.357 |
Discussion
The occurrence of anal fistula is more common in men than women, most often developing in the age range of 20–50, consistent with Amato A. et al. [
23]. Compared with women, men have more unhealthy habits such as smoking, excessive drinking, staying up late, eating spicy food, etc., which leads to weakened immunity, intestinal dysfunction, acute and chronic enteritis, inflammatory bowel disease and other diseases that are more likely to cause anal glands infection [
24‐
26]. Patients with perianal abscesses with long-term chronic systemic diseases are clinically more common with diabetes, and poor blood sugar control is a risk factor for long-term non-healing of wounds after perianal abscess surgery [
27]. In this study, the univariate analysis of gender, age, and diabetes mellitus had no significant difference in the effect of postoperative abscess healing [
28]. After patients with perianal abscesses are hospitalised, our hospital has repeatedly carried out rigorous health education for a long time to avoid unhealthy living and eating habits and long-term follow-up supervision during postoperative dressing changes; for patients with diabetes, postoperative blood glucose control is highly emphasised, thereby reducing the adverse effects of gender, age, diabetes and other factors in patients with perianal abscess surgery.
Perianal abscess is a common perianal disease. The treatment focus is improving the cure rate and reducing recurrence or the formation of anal fistula. It is crucial to evaluate the condition of the perianal abscess before surgery. The preoperative blood routine examination is a routine clinical examination. Although the specificity and sensitivity are poor, the low perianal abscess can often be manifested as a normal peripheral blood routine in this study, especially the subcutaneous abscess around the anus; the routine blood white blood cell count of patients with high perianal abscess is often high. Univariate analysis showed a statistically significant difference between white blood cell count and postoperative recurrence; multivariate analysis reveals it to be a non-independent influencing factor. Zhang Yingyi et al. identified that the mean platelet volume might thus be an indicator of perianal abscess severity [
29]. In terms of device inspection, there have been significant advancements in clinical practice in recent years. In the past, only experienced clinicians used preoperative digital anal examinations to understand the extent and depth of the lesion, which caused considerable misjudgment. Intraoperative drainage, especially with high septal abscesses, is a risk factor for the postoperative cure of perianal abscesses. Advancements have been made in medical imaging, including the development of perianal rectal ultrasound, spiral computed tomography (CT), and MRI of the perineum. Despite these advancements, the clinical use of perianal rectal ultrasonography is limited, partly due to the local pain it may cause during the procedure and the requirement for clinicians to have experience in using B-mode ultrasound. Magnetic resonance imaging has been widely used in clinical treatment, especially high-resolution MRI, which can clearly show the extent of the lesion, the interval of the abscess cavity, and the internal mouth better than CT examination [
23]. In this study, a preoperative MRI examination was performed. During the operation, the internal port was successfully found, and the thread-attached drainage accounted for 87.1%, which was significantly higher than that without the MRI examination, and the internal port-attached thread was 55.2%. The logistic regression analysis of intraoperative thread-hanging radical drainage and drainage is an independent influencing factor. It can treat the infected internal anal gland of abscess from the root cause and is better for postoperative curing than simple incision and drainage.
The data of this study has certain limitations. First, because it was a retrospective study, some patients’ contact information was missing; second, because of the acute onset of perianal abscess, some patients were treated from other hospitals and then admitted to our hospital for surgery, and the clinical data of the patients’ preoperative examinations were missing. As a result, data collection has a certain loss rate, which may impact data analysis. The sample research can be further expanded in the follow-up, and a higher level of evidence support can be provided through more complete clinical data.
In summary, the extent of the abscess cavity and the surgical method are independent factors for the recurrence of perianal abscess or the formation of anal fistula; the extent of blood routine and MRI examination are the risk factors for postoperative healing. Therefore, the severity of inflammation and infection can be indicated according to the range of blood routine before surgery; if the blood routine value is high in white blood cells, the MRI examination should be improved as much as possible. For deep and large-scale abscesses, the internal opening should be explored as much as possible during the operation, and adequate drainage should be made. For patients with chronic systemic diseases, appropriate active treatment can minimise the impact on the prognosis of patients with abscesses.