Evolution of Perianal Pathology in Patients Undergoing Bariatric Surgery. A Prospective, Multicentre Study With 12-month Follow-up.

doi:10.21203/rs.3.rs-4992234/v1

Introduction: Bariatric surgery provides good weight-loss results over the medium to long term, improving a significant number of comorbidities. Benign anal pathology is common; in addition, obesity is part of the pathophysiology of some of these diseases.

Objectives: The aim of this study is to describe and analyse benign anal pathology in patients affected by obesity who are candidates for bariatric surgery, as well as to assess its evolution after 12 months following weight-loss surgery.

Methodology: A descriptive, prospective, multicentre study was designed. Seventy patients who were candidates for bariatric surgery were included. At first contact, initial descriptive variables (weight, BMI, etc.) were collected, a perianal examination was performed, and quality-of-life questionnaires (SF12v2, HEMO-FISS-QoL) were completed. The second contact took place 12 months after surgery, in which the variables and questionnaires were again recorded.

Results: At 12 months from the intervention, a significant decrease in both the prevalence of symptomatic internal haemorrhoids and external haemorrhoids (p<0.001) was observed. The mean number of acute hidradenitis suppurativa flare-ups decreased significantly, to 0.22 over the preceding 6 months (p<0.001). Quality of life improved significantly, both generally and in relation to perianal pathology.

Conclusion: Patients who underwent bariatric surgery using restrictive and hypoabsorptive techniques showed an improvement in their perianal pathology, as well as a significant improvement in their quality of life. To consolidate these results more studies are required that encompass a larger number of patients and a longer evolution period.

obesity surgery

perianal disease

perianal hidradenitis suppurativa

haemorrhoidal disease

Perianal pathology is more common in people suffering from obesity.
This condition negatively affects quality of life.
To date, no study has evaluated the influence of bariatric surgery on perianal pathology.
Patients undergoing bariatric surgery using restrictive and hypoabsorptive techniques showed an improvement in their perianal pathology, as well as a significant improvement in their quality of life.

In recent years, obesity has become a major public health issue, to the point that, according to the WHO report published in 2022, 60% of citizens in the European area are suffering from overweight or obesity¹. Obesity is associated with a significant number of comorbidities, including cardiovascular comorbidities (arterial hypertension (AHT), dyslipidemia, and type 2 diabetes mellitus (DM-2) etc.) as well as other types of associated pathologies (obstructive sleep apnoea syndrome (OSAS), osteoarticular problems, and hepatic steatosis etc.). According to the latest IFSO recommendations, bariatric and metabolic surgery is the recommended treatment for patients with a Body Mass Index (BMI) ≥ 35Kg/m², regardless of the presence or absence of associated comorbidities², whereas non-surgical treatments are recommended for patients with metabolic disease and a BMI between 30 and 34.9 kg/m² who do not achieve sufficient or sustained weight loss, or improvement in their comorbidities. Bariatric surgery achieves good results in relation to weight loss over the medium to long term, in addition to improving a significant percentage of comorbidities in this type of patient and reducing the risk of mortality from cardiovascular disease³.

On the other hand, benign anal pathology is highly prevalent in the general population, although not all patients affected by it are assessed in surgical consultations^4,5. The shame associated with this type of pathology means that a percentage of patients who suffer from it prefer not to go to their specialist and start treatment empirically. In fact, most patients are treated directly by their primary care physician rather than being assessed by general and digestive surgeons. It is a pathology that, if left untreated and it becomes chronic, can affect the patients’ quality of life. Most consultations for anorectal symptoms are due to the presence of anorectal pain, rectorrhagia, discharge, pruritus, or a tumour in the perianal region, although most result from a combination of some of these symptoms⁶.

Within the main anal pathologies, the most frequent (and for which patients usually come to the clinic) are haemorrhoids, anal fissures, anal fistulas, pilonidal sinus and perianal hidradenitis⁶. Among the pathophysiology of some of these conditions, obesity plays an important role in several^7–9.

The aim of our study is to describe and analyse benign anal pathology in patients affected by obesity who are candidates for bariatric surgery, as well as to assess their evolution following weight loss 12 months after surgery.

The protocol for this study has been developed in accordance with the guidelines established by the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement for observational studies.

This is a prospective, observational, multicentre study, in which perianal pathology in patients who are candidates for bariatric surgery was evaluated along with its impact on quality of life. The study was approved by the corresponding local Ethics Committee.

Patient selection:

Those selected were patients diagnosed with obesity, with a BMI ≥ 35Kg/m², assessed as being suitable for bariatric surgery by the Bariatric Surgery Unit of the General Surgery Service at xxx and xxx.

Before considering surgery, all the patients were assessed by a multidisciplinary team, which consisted of endocrinology, nutrition, psychology and surgery. The type of intervention chosen is individualized according to each patient: One-anastomosis laparoscopic gastric bypass (OAGB), laparoscopic vertical sleeve gastrectomy (LVSG), or simplified laparoscopic gastric bypass (SLGB).

Variables:

The variables were agreed upon by an expert team of bariatric surgeons and coloproctologists. These comprised the specific characteristics of benign anal pathology including bowel habits (the number of bowel movements and type according to the Bristol classification¹⁰), the existence of an anal fissure (anal pain associated with a fissure evidenced on anal examination), haemorrhoidal pathology (symptoms related to internal haemorrhoids: bleeding, pruritus, prolapse, as well as the existence of external haemorrhoids), perianal hidradenitis (according to the Hurley scale¹¹), pilonidal sinus (the existence of fistulous orifices in the sacrococcygeal region) and anal fistula (the existence of an external anal fistulous orifice with active suppuration).

Data collection:

The patient's anamnesis was taken on admission, prior to performing surgery. This included personal and contact data, as well as those related to their personal records. An anal examination was performed in the left lateral decubitus position (Sims) to assess the existing anal pathologies and make a detailed description of each of them.

The patient was given two questionnaires, the HEMO-FISS-QoL¹² (to assess the impact of perianal pathology on quality of life) and the SF12-V2¹³ (to assess the patient's quality of life generally).

The patients were assessed again at 12 months after surgery by the same surgeons, carrying out an exhaustive anal pathology examination. As before, both questionnaires (HEMO-FISS-QoL¹²and SF12-V2¹³) were completed.

Statistical analysis:

For the descriptive study, the means and their standard deviation (SD) were represented to express the quantitative variables. The qualitative variables were expressed according to the number (n) and fraction represented by the total (%). Continuous variables were compared using Student's t-tests for independent data and the Mann-Whitney U test for variables that did not follow a normal distribution. For the categorical variables, Chi-square tests or Fisher's exact test were used. The statistical analysis was obtained with SPSS® version 22 software (SPSS, Inc., Chicago, IL), and a value of p < 0.05 was considered statistically significant.

A total of 70 patients who were candidates for bariatric surgery were included in the study. After follow-up, two patients were excluded for not attending the check-up. The population characteristics are shown in Table 1. The sample comprised 62.86% women (n = 44) with a mean age of 46.76 years.

Table 1: Demographic variables, physical exercise, and bowel habits

	Initial (n=70)	12 months (n=68)	Significance (p)
Weight (kg): mean, (SD)	127.60 (25.27)	79.69 (19.66)	.000
BMI (Kg/m2): mean, (SD)	45.74 (6.56)	23.85 (5.30)	.000
Physical exercise: n (%) Hours per week: average (SD)	22 (31.4%) 1.72 (2.87)	47 (69.12%) 3.63 (3.60)	.000 .000
Stool habit: mean, (SD)	11.40 (6.02)	10.07 (4.53)	0.072
Bristol Scale: Mean, (SD)	3.87 (0.93)	4.43 (0.85)	.000

Preoperative results

The mean preoperative weight was 127.60 kg (25.27 SD), and the BMI was 45.74 kg/m²(6.56 SD).

In relation to bowel habits, patients had an average of 11.40 bowel movements per week (6.01 SD). Regarding consistency measured according to the Bristol scale, the mean value was 3.87 (0.93 SD).

Regarding perianal pathology (shown in Table 2), the most frequent pathology was the presence of symptomatic internal haemorrhoids, affecting 61.43% of the sample (n=43) while 42.86% of the patients (n=30) had external haemorrhoids; 12.85% (n=9) suffered from hidradenitis suppurativa, with a mean of 2.11 exacerbations (1.45 SD) over the preceding 6 months.

Table 2: Perianal pathology-related variables.

	Initial (n=70)	12 months (n=68)	Significance (p)
Fissure: n (%)	7 (10%)	5 (7.35%)	0.321
External haemorrhoid: n (%)	30 (42.86%)	19 (27.94%)	.000
Internal haemorrhoid: n (%) Bleeding Pruritus HI Grade: mean (SD)	43 (61.43%) 25 (58.14%) 29 (67.44%) 1.51 (0.77)	37 (54.41%) 5 (13.51%) 7 (18.91%) 1.22 (0.58)	.000 .000 .000 .000
Hidradenitis suppurativa: n (%) HS Grade: Mean (SD) Exacerbations over last 6-month: mean (SD)	9 (12.85%) 1.11 (0.33) 2.11 (1.45)	9 (13.23%) 1 (0) 0.22 (0.44)	- 0.347 .008
Fistula: n (%)	1 (1.43%)	1 (1.47%)	-
Sinus: n (%)	4 (5.71%)	3 (4.41%)	-
SF12: Mean (SD)	37.78 (7.18)	48.65 (7.34)	.000
HEMO FISS QoL	2.08 (0.91)	1.34 (0.58)	.000

To date, few studies have looked at the evolution of bariatric surgery in terms of benign anal pathology in patients affected by obesity^14–16. In our study, a high percentage of the patients who were candidates for bariatric surgery presented with anal pathology (61.43% of them presented with symptomatic internal haemorrhoids and 12.85% had hidradenitis suppurativa), and it is evident how this had improved 12 months after the intervention, both in its diagnosis and in the patient's quality of life.

Various authors have described an association between certain aspects of benign anal pathology (mainly internal haemorrhoids, pilonidal sinuses, and perianal hidradenitis) and obesity^7,17–20. Marco et al⁷ described BMI as an important risk factor for hemorrhoidal disease based on the hypothesis that some pathophysiological mechanisms, such as increased intra-abdominal pressure, venous congestion, and chronic inflammation, contribute to the development of hemorrhoidal disease in patients with obesity. Riss et al¹⁷, in their study on 976 patients, observed that BMI was significantly associated with the occurrence of hemorrhoidal disease (an increase in BMI increased the risk of hemorrhoidal disease by 3.5%). Smoking and obesity are the two environmental factors most strongly related to hidradenitis suppurativa, a chronic inflammatory disease that affects the follicular epithelium of skin folds. A systematic review that included 6,174 cases of patients with hidradenitis suppurativa and 24,993 controls demonstrated an odds ratio (OR) of 3.45 (95% CI: 2.20–5.38, p < 0.001) for hidradenitis and obesity¹⁸. Both the higher number of packets/year smoking and higher body mass index (BMI) were associated with greater disease severity. Kromann et al²¹, in their cross-sectional study on 202 patients, concluded that both smoking and obesity were significantly related to a lower rate of self-reported remission. The underlying mechanisms proposed included local skin surface factors due to the warm and moist environment in the skin folds of patients with obesity and shear forces caused by clothing and skin-to-skin contact²¹. In relation to pilonidal sinus, obesity is considered a risk factor, along with others (local hirsutism, deep gluteal clefts, sedentary lifestyle over long periods, increased sweating, and poor hygiene)²², so preventive strategies and non-surgical treatment, such as hair removal and weight loss, have been suggested. Hu et al²³, following their study in which they used a two-sample mendelian randomization analysis to assess the causal relationship between obesity and skin and soft tissue infections, suggested that obesity increases the risk of these types of infections, which they relate to the metabolic effects of obesity and inadequate blood supply to adipose tissue; this leads to poor host immune response and thus decreases the skin's defences.

The above would suggest that weight loss after bariatric surgery could be accompanied by a decrease in this pathology. However, some of the techniques used involve a malabsorptive component that can increase the number of bowel movements and, in turn, increase the frequency or worsen the anal pathology present in these patients.

Guedea et al¹⁵ carried out a study on 263 patients who had been operated on using the Scopinaro procedure - a follow-up after 5 years showed an increase in daily diarrheal stools (a mean of 3.5), which they considered a triggering factor of anal pathology, secondary to the chemical irritation caused by steatorrhea. In fact, they observed in a statistically significant way that the greater the number of bowel movements, the greater the existence of anal disease. The incidence of new-onset anal pathology was 18%, after a mean follow-up of 5 years. Anal fissure was the most frequently described disorder, with an incidence of 8% in all patients. Pain after bowel movements was the main symptom for which they went to the emergency room. Its most frequent location was lateral atypical anterior, unlike the general population where the fissure is more frequently located in the posterior midline. In these cases, treatment with conservative measures was satisfactory. These are patients operated on using a malabsorptive technique, and they have a high number of liquid stools per day. Nowadays, this intervention is performed by only a few professionals because of the side effects described (hypoproteinaemia and vitamin and trace element deficiencies). In our group, the techniques performed are not malabsorptive (only OAGB has a hypoabsorptive component). According to our results, it did not cause a significant increase in the number of bowel movements in our patients. The results obtained by our team can be seen to represent a significant improvement in symptomatic hemorrhoidal disease, which decreased from 61.43–54.41%. This improvement could be due to the decrease in BMI, as previously reported by other authors^7,17. Regarding anal fissures, in our study no significant modification was observed; indeed, its prevalence decreased from 10–7.35%.

Cano-Valderrama et al³ conducted a retrospective observational study on a total of 137 patients who underwent gastric bypass and biliopancreatic diversion. The study showed that, at follow-up, a significantly higher percentage (37.2%) of patients had developed new-onset anal pathology than observed in the general population. Of these, 27% had to be treated by anorectal surgery, suggesting a serious complication that had a significant impact on their quality of life. Haemorrhoids and anal fissures were the most frequently diagnosed postoperative pathologies, appearing more frequently after biliopancreatic diversion (52.9%) than after gastric bypass (21.7%) (p < 0.01). Multivariate analysis found that only abnormal bowel habits were associated with new-onset anal pathology, with an odds ratio of 3.2 (95% CI 1.5–6.9, p 0.003).

Garcovich et al²⁴, in their cohort of patients with hidradenitis (n = 178), identified 12 patients with prior exposure to a bariatric surgical procedure, concluding that hidradenitis after bariatric surgery comprises a new subset of patients, and that it represents an important challenge in clinical management, which should include a complete nutritional assessment and control of micronutrient deficiencies. It should also be noted that, of the 12 patients, 10 of the surgical procedures were biliopancreatic diversions and two were mini-gastric bypasses. In our study, the incidence of hidradenitis suppurativa remained stable after surgery, with a significant decrease in the number of exacerbations, suggesting that a decrease in BMI could influence its evolution. This might be explained by the pro-inflammatory state in which the patient affected by obesity finds him/herself, with a decrease (after surgery) in the production of adipokines (leptin, resistin, visfatin) involved in the pathogenesis of hidradenitis suppurativa²⁵.

To assess quality of life, two different questionnaires were used in our study. On the one hand, a specific questionnaire that assesses the impact of perianal pathology on the patient's quality of life (HEMO-FISS-QoL) and, on the other hand, a generic questionnaire to assess general quality of life (SF12v2). In our sample, the values obtained in both questionnaires prior to surgery show a moderate impact on quality of life. This is consistent with the above, as well as with what was described by Abramowitz et al^12,26, who describe a moderate impact of perianal pathology on the patient's quality of life, worsening at acute moments or when it affects other spheres of their daily life. According to our results, weight loss after 12 months is accompanied by an improvement in the patients' quality of life. For the HEMO-FISS-QoL questionnaire, the results show perianal pathology having less negative impact on quality of life, with the improvement being statistically significant. This is consistent with the results of the SF12v2 questionnaire, where a significant improvement in the mean score was observed.

The main limitation of our study is its small sample size. In addition, it is a multicentre study, including patients who were operated on in two different institutions, although they were examined by the same surgeon.

In conclusion, we can state that those patients who underwent bariatric surgery using restrictive and hypoabsorptive techniques showed an improvement in their perianal pathology (mainly in hemorrhoidal pathology and hidradenitis suppurativa), as well as a significant improvement in their quality of life as it relates to this pathology. Nonetheless, further studies comprising larger numbers of patients and longer evolution periods are required to consolidate these results.

Informed consent was obtained from all individual participants included in the study. The study was approved by the corresponding local Ethics Committee.

Conflicts of interest: The authors declare no conflicts of interest.

Funding declaration: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors

Author Contribution

MF and MG wrote the manuscript textMG and AF have carried out the statisticsMF, MG, FR and RB have carried out data collectionAll authors reviewed the manuscript

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No competing interests reported.

Evolution of Perianal Pathology in Patients Undergoing Bariatric Surgery. A Prospective, Multicentre Study With 12-month Follow-up.

Status:

Version 1

Abstract

KEYPOINTS

Introduction

Methodology

Patient selection:

Variables:

Data collection:

Statistical analysis:

Results

Discussion

Declarations

Author Contribution

References

Additional Declarations

Status:

Version 1