Why does a fistula form and not heal?
The internal opening of the fistula is almost always located in the anal crypt - in the same place where paraproctitis began. Through it, intestinal contents with microflora constantly enter the canal. The external opening opens on the skin of the perineum, sometimes at a distance of several centimeters from the anus. Between them is a passage covered from the inside with granulation and scar tissue. The body tries to close it, the external opening sometimes closes, but the outflow stops, the contents accumulate, an abscess forms, and everything opens again. Hence the typical wave-like picture: first it “heals”, then it’s an abscess again.
It is worth understanding that fistula is not a separate disease, but a chronic stage of the same one. In medical documents it is often designated as such: chronic paraproctitis. Awareness of this continuity eliminates the frequent question “why do I have a problem again after surgery for an abscess.” Opening the abscess solved the urgent problem of removing the pus and removing the threat; elimination of the course is a planned and technically more delicate work that cannot be performed efficiently in the midst of inflammation. These are two different interventions with different goals, and the second is not a fix for the first.
- Consequence of acute paraproctitis - up to 90% of all cases
- Crohn's disease - fistulas with it are of a different nature and require the participation of a gastroenterologist
- Perineal injuries and consequences of operations in the anorectal area
- Complications of childbirth in women - a separate group of rectovaginal fistulas
- Tuberculosis, actinomycosis, specific infections - rare causes
How it manifests itself
- A small hole or lump in the skin near the anus
- Constant or periodic discharge - sanguineous, purulent, sometimes mixed with feces and gases
- Skin irritation and weeping, itching, need to use a pad
- Moderate pain, intensifying before the next exacerbation and subsiding after a breakthrough
- Periodic rises in temperature when closing the external opening
- Foreign body sensation and discomfort when sitting
A fistula is rarely excruciatingly painful without an exacerbation - this is precisely what allows you to live with it for years. The main complaint often sounds not like pain, but like constant uncleanliness and forced restriction of social life, which is embarrassing to talk about.
Before surgery, daily care is important: washing with cool water after defecation without aggressive soap, loose cotton underwear, protecting the skin around the external opening from getting wet, and regularly changing the pad. Irritation of the skin of the perineum is not a cosmetic problem: inflamed skin tolerates intervention less well and takes longer to heal. And one more thing: attempts to rinse the fistula tract with solutions and ointments on your own are useless and can disrupt the outflow, provoking another exacerbation.
It is worth paying attention to the nature of the discharge. Scanty bloody discharge is a common condition without exacerbation. The appearance of thick pus, increased pain and cessation of discharge with increasing distention means that the outflow has closed and a new abscess is forming; This is not a situation for observation at home, but for a visit to the doctor in the coming days. An admixture of feces and gases in the discharge indicates a wide internal hole and also requires evaluation by a specialist, and not changing the pads.
Classification: the operation depends on it
Fistulas are divided according to the relation to the sphincter muscle. It is this characteristic, and not the length of the canal or the volume of secretions, that determines which technique can be used safely.
- Intrasphincteric (subcutaneous-submucosal) - the passage passes outside the muscle mass or involves a minimal part of it; easiest to treat
- Transsphincteric - the passage crosses part of the sphincter fibers; tactics depend on what proportion of the muscle is involved
- Extrasphincteric - the passage goes high and goes around the sphincter from the outside; the most complex option, often with streaks and branches
- Simple and complex: fistulas with several passages, cavities, recurrent, anterior in women, as well as fistulas in Crohn's disease are considered complex
Separately assess whether there are additional passages and purulent leaks. Their presence makes the fistula a complex one, no matter how high the internal opening is located: an undetected leak remains a source of inflammation and almost guarantees the return of the disease, no matter how careful the main intervention is. The search for such branches is the main value of MRI before a planned operation - the doctor receives a map in advance, and does not figure out the anatomy along the way.
Examination before surgery
- Осмотр и пальцевое исследование прямой кишки — определяются наружное отверстие, плотный тяж хода и внутреннее отверстие.
- Аноскопия и ректороманоскопия — осмотр анального канала и нижних отделов прямой кишки.
- Зондирование свищевого хода и проба с красителем — уточняют направление и наличие внутреннего отверстия.
- УЗИ ректальным датчиком — оценивает ход, затёки и состояние мышц сфинктера.
- МРТ малого таза — метод выбора при сложных, рецидивных и разветвлённых свищах; показывает всю анатомию до операции.
- Колоноскопия и обследование на disease Крона — при множественных свищах, диарее, потере веса, свищах в молодом возрасте.
- Оценка функции удержания до вмешательства — важна для сравнения с результатом после.
An examination for a fistula is not a formality and not a way to “collect procedures”: the choice of operation, and therefore the outcome of the treatment, directly depends on its result. The worst scenario is when the true anatomy of the tract becomes clear during the intervention, and the surgeon has to make a decision on the fly, without the opportunity to discuss it with the patient. Therefore, they go to a planned operation for a fistula with a ready-made picture: where is the internal opening, where does the passage go, how much muscle does it cross, and are there any leaks.
Types of operations and preservation of sphincter function
There is no universal operation. All techniques are a compromise between two goals: to reliably eliminate the fistula and not to disrupt continence. The more muscles are affected, the more the surgeon leans towards sphincter-sparing techniques, which have lower radicality, but the risk of incontinence is minimal.
- Excision of the fistula into the intestinal lumen is a classic and most reliable operation, used for intrasphincteric and low transsphincteric fistulas, when a small part of the muscle is intersected
- Excision with suturing of the sphincter - with greater involvement of muscle fibers
- Ligature (draining and “cutting” seton) - a thread is passed through the passage: first as drainage to subside inflammation, then as a way to gradually, rather than immediately, separate the muscle, which allows it to grow together as it erupts
- Reduction of the mucomuscular flap - the internal opening is closed with the intestine's own tissue without crossing the sphincter
- Ligation of the tract in the intersphincteric space is a sphincter-saving technique for transsphincteric fistulas
- Laser obliteration and treatment of the tract from the inside are low-traumatic options, applicable for suitable anatomy, usually require preliminary drainage
- Two-stage tactics - first installing a drainage seton and relieving inflammation, then a radical stage on “quiet” tissues
The sphincter is not one muscle, but a complex of internal and external sphincter. The internal one works involuntarily and is responsible for keeping one at rest, the external one is responsible for voluntary restraint. Damage to the internal sphincter is not noticeable in the first months, but manifests itself years later with leakage and failure to retain gases. That is why an experienced surgeon will prefer a two-stage operation with a slightly longer treatment period to a one-stage intervention with a risk to the muscle.
Surgeries for a fistula are performed under spinal or general anesthesia and are planned in advance - this is a fundamental difference from an emergency opening of an abscess. The surgeon has the opportunity to choose a technique based on examination data, rather than act according to circumstances. For the same reason, they try to carry out intervention outside of exacerbation, on calm tissues: at the height of inflammation, the boundaries of the course are blurred, the tissues are swollen, and the risk of both relapse and damage to the sphincter is higher. If a patient presents with an exacerbation, drainage first, then elective surgery a few weeks later, is often a reasonable strategy.
After surgery and the likelihood of relapse
- Заживление раны при иссечении свища занимает в среднем 3–6 недель, при сложных вмешательствах дольше.
- Перевязки, контроль за тем, чтобы рана заживала снизу вверх и края не смыкались преждевременно.
- Мягкий регулярный стул — обязательное условие: клетчатка, вода, при необходимости мягкие слабительные по назначению.
- Ограничение подъёма тяжестей и длительного сидения на срок, который определит врач.
- Контрольные осмотры: даже при хорошем самочувствии важно показаться в назначенные сроки, чтобы вовремя заметить незакрывшийся ход.
It’s also worth adjusting to the duration. A fistula is not an operation after which the problem is forgotten the next day: healing takes weeks, dressings require discipline, and with a two-stage tactic, months pass between interventions. But the result is assessed not by speed, but by two things: whether the move is gone completely and whether the hold is maintained. Both goals are achieved through patience, and an attempt to speed up the process usually results in a return to the beginning.
