Sclerotherapy or Injection
What is Sclerotherapy?
Sclerotherapy is commonly used to treat bleeding internal
hemorrhoid. In this procedure, a sclerosing or hardening solution
(also called a sclerosant) is injected into the base of the
There are many types of sclerosants, including chemical (phenol
in almond oil) and saline solutions, but they all do the same
thing: they cause a low-grade, long-standing inflammation
reaction which “scar” the vein and mucosal tissue,
collapse the vein walls, and cause the hemorrhoids to shrivel.
Advantages & Disadvantages
The advantages of sclerotherapy include:
- Easy and inexpensive to administer, can be used as
an out-patient procedure
The technique of sclerotherapy is simple to learn and it
is not complicated to perform as an inexpensive out-patient
procedure. No costly anesthesia or lengthy hospital stay
- It works fast and last long
Approximately 7 to 10 days after the procedure, the shriveled
hemorrhoid should fall off during normal bowel movement.
In general, the patient should then be symptoms free and
does not suffer from bleeding hemorrhoid for at least 12
- Can be performed in elderly patients
Sclerotherapy is usually the method of choice for treating
small hemorrhoids in elderly patients, who have fragile
- Multiple hemorrhoids can be treated at once
Typically, up to 3 hemorrhoids can be injected per treatment.
The disadvantages of this procedure include:
- Large incidence of failure for larger hemorrhoids
Because there is a high likelihood of failure of injection
therapy for large hemorrhoids, and the availability of other
treatment methods (such as rubber band ligation), sclerotherapy
should not be used.
- Hemorrhoid returns after treatment
Sclerotherapy is not a cure for hemorrhoids. Piles can and
do come back after being injected, although usually not
within 12 months after the treatment.
Who Should Get Sclerotherapy?
Sclerotherapy should be used only for smaller hemorrhoids,
such as first-degree and early second-degree piles.
First-degree piles, even those which are bleeding profusely,
usually respond well to sclerotherapy (or in some cases, multiple
treatments of sclerotherapy). However, other contributing
causes for the bleeding, such as the use of aspirin or contraceptive
pill, should first be stopped.
Second-degree hemorrhoid, in which the prolapse is slight
or barely noticeable, also responds well to this procedure.
However, as the hemorrhoid becomes larger, the chance of success
becomes smaller and multiple injections may be necessary.
In this case, either the initial treatment should consist
of multiple injections or a follow-up treatment should be
Who Should NOT Get Sclerotherapy?
Sclerotherapy should not be performed if the patient has:
- Acute prolapse-thrombosis
Third-degree hemorrhoids should not be treated with sclerotherapy,
because the risk of acute prolapse-thrombosis - a complication
where painful blood clots develop - is very high.
Large second-degree hemorrhoids should also not be treated
with this procedure, because the chance of success is not
- Severe bleeding or ulceration
Hemorrhoids that are accompanied by other ano-rectal conditions,
such as inflammatory bowel diseases (Crohn’s disease
and ulcerative colitis), sclerotherapy may cause severe
bleeding or formation of ulcers in the colon’s mucosal
- Fissures and fistula
Anorectal conditions such as fissure and fistula-in-ano
are contraindications to sclerotherapy.
The patient should be advised to defecate shortly before
the treatment, as passing stool shortly after the therapy
may disperse the sclerotherapy solution and therefore reduce
The anal canal should be properly lubricated and local anesthetic
gel is applied. In addition to preventing pain, the application
of local pain killer can help reduce patient anxiety.
The patient is usually laid down on his or her left side
in the left lateral position, with the buttocks projecting
over the edge of the table.
A proctoscope with a wide-bore is inserted into the anal
canal to illuminate the hemorrhoid to be injected.
Injection should be done at the base of the hemorrhoid,
above the dentate line, where no or little pain should be
felt. This is because the dentate line separates the insensitive
columnar epithelium from the sensitive squamous epithelium
below. If pain is felt when the needle pierces the tissue,
it is likely that the injection site is incorrect.
Once the correct injection site is located, the needle is
inserted about 1 to 2 cm deep, parallel to the anal canal.
About 3 to 5 ml of sclerosant is injected slowly, allowing
time for dispersion in the tissue. While being injected,
the patient should be asked whether pain is felt –
if so, the injection should be stopped immediately.
After the injection is complete, the needle should not be
withdrawn immediately, since this may lead to bleeding and
leaking of the sclerotherapy solution. Instead, the needle
should be held in place for about two minutes, then slowly
withdrawn to facilitate the sealing of the tract.
In most patients, a maximum of three separate injections
to the bases of the hemorrhoids are given.
When proper technique is employed, the patient should not
experience more than mild ache or discomfort.
Serious complications from sclerotherapy are rare –
they occur in only approximately 0.02% or 1 in 5,000 injections
– and arise mostly from improper technique.
Possible complications include:
Immediate bleeding may be caused by accidentally puncturing
an artery and can almost always be stopped by immediate
pressure using gauze.
Delayed bleeding can be caused by too much solution being
injected, or by wrongly injecting the mucosa layer instead
of beneath it. This can cause an ulcer to develop and bleeding
7 to 14 days after the injection, requiring hospitalization.
Although discomfort or aching is normal, real pain is not
and is almost always caused by improper selection of injection
site. Injection should be done above the dentate line, which
separates the anus from the rectum. Sometimes, even though
the injection site is correct, the sclerotherapy solution
or sclerosant can spread below the dentate line into the
Once pain is felt, the injection should be stopped immediately.
Usually, the pain is short-lived and can be managed by topical
Aching and discomfort within the first 24 hours of injection
are normal and can be managed by over the counter pain killers
such as aspirin.
- Injection into the vein
If the solution appears to be injected too easily or if
the patient notices pain in the liver area or unpleasant
taste in the mouth, the needle has accidentally entered
anal veins – injection should be stopped immediately.
There is no harmful side effect of this complication, although
since the sclerotherapy solution is dispersed through the
body’s circulatory system, it should not be expected
to be effective in dealing with the hemorrhoid.
- Injection into the prostate
Accidental injection into the prostate is possible, especially
if the patient is a man suffering from enlarged prostate.
It is also possible to accidentally inject into the vein
that goes between the prostate and the rectal area.
Depending on the amount of sclerosant that enters the prostate
and the depth of penetration, the complications vary from
relatively minor to very serious:
- Retention of urine
Here, the patient is unable to urinate. This is the
most common (and minor) of complications from accidental
injection into the prostate. Usually, the situation
resolves by itself without medical intervention, although
in some patients temporary insertion of a catheter tube
to aid urination is required.
If the solution enters the seminal vessel and spread
to the testicle and its tissues, withering of the testicles
and infertility may occur.
- Inflammation of the prostate glands (or prostitis)
The symptoms of prostitis include partial incontinence,
frequent urination, pain, burning sensation during urination,
blood or pus in the urine. These symptoms may last weeks,
months, or even years – and although antibiotics
should be prescribed, there is no direct treatment for
- Abscess formation
A deep injection into the prostate can cause an abscess
or a pus-filled inflammation in the prostate glands.
This may require surgery by a urologist.
- Painful blood clot formation
If a large second-degree or third-degree hemorrhoid
is improperly treated by sclerotherapy, very painful
blood clots may be formed. This may require more radical
procedures such as anal dilation or surgery.
After the Procedure
After a short period to recover, the patient can be sent
home if there are no immediate bleedings. Mild aching and
discomfort is common, and can be treated by pain killers –
codeine should be avoided since it can cause constipation.
To avoid the injected solution from dispersing by straining
to pass stool, the doctor may prescribe a lubricant suppository
and a stool softener.
A follow-up appointment is usually set for three weeks after
the treatment, at which time more injections may be necessary
if the symptoms of the hemorrhoid are not resolved.