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Open Hemorrhoidectomy
(Milligan–Morgan Technique)
In 1935, E.T.C. Milligan and C. Naughton Morgan at the St.
Marks Hospital pioneered a surgical technique for the removal
of hemorrhoids that is still widely used worldwide today.
Selection of cases
Prior to selecting open hemorrhoidectomy, the following factors
are considered:
- Grade of hemorrhoids
Although the Milligan-Morgan technique can be used to treat
any degree of internal hemorrhoid, it is usually used to
treat large second-degree cases, such as those too large
for rubber band ligation, and third-degree cases, involving
pronounced or permanent prolapse.
- Age of the patient
In rare cases of large hemorrhoids in young patients (less
than 35 years), surgery usually do not produce lasting result
and the hemorrhoid usually recur. For this reason, hemorrhoidectomy
should be postponed until the patient are 40 years or older.
- Pre-existing medical condition
Inflammatory bowel diseases such as Crohn’s disease
and immune deficiency due to AIDS are contraindication to
this procedure. Cancer is also a contraindication to this
procedure, as live cancer cell can be implanted in open
wounds.
Open hemorrhoidectomy should also not be performed on pregnant
women, as it may lead to hemorrhoid recurrence due to labor
difficulties.
Preparation
Prior to hospital admission, the patient should be advised
to take the appropriate steps to ensure healthy bowel habits
and the passage of soft stool. The patient is also given a
thorough medical examination to diagnose pre-existing conditions.
Some patients with large hemorrhoids may have heavy mucus
discharge and fecal contamination that create a soggy and
inflamed skin at and around the anus. These may have to be
treated prior to the surgery.
Prior to the treatment, a suppository or enema should be
given to empty the rectum from fecal materials.
Position
Open hemorrhoidectomy can be performed either in the lithotomy
or prone position. In the lithotomy position, the patient
lies on his or her back, with the buttocks raised by a firm
pad and projecting over the edge of the table. In the prone
position, the patient lies face down with the buttocks projecting
upwards.
Many surgeons prefer the prone position, as it helps venous
circulation from the ano-rectal area, and allows easy run-off
of any blood during the excision of the hemorrhoids. However,
extra care should be used to prevent restriction of breathing
and ensure proper lung inflation during surgery.
In both positions, the buttocks are strapped back with adhesive
tape to facilitate access, especially for obese patients.
Once the patient is in position, the surgeon usually shaves
the operation area to help keep the area clean during post-operative
healing.
Procedure
The general procedure of the Milligan-Morgan hemorrhoidectomy
is as follows:
- Antiseptic application
The anal canal and lower rectum are manually cleaned using
soft moist tissues, and antiseptic solution is applied to
the buttocks and anus. Water-based and inert solution, such
as Betadine is preferable, since alcohol-based solutions
can accidentally ignite if cauterization is used and chemical
solutions can cause skin sensitivity. Surgical drapes are
then put on to allow unimpeded exposure to the area to be
operated.
- Injection of vasoconstrictors
The surgeon would start by injecting a weak solution of
adrenaline in bupivacaine or lignocaine at three or four
sites around the anus to constrict the blood vessels and
reduce bleeding. After three to five minutes, the surgeon
should review the plan to remove the piles while preserving
the skin bridges between the hemorrhoidal masses.
- Pulling out of the hemorrhoids
After deciding on the skin bridges to be preserved, the
hemorrhoids are teased out gently with the surgeon’s
index finger. Small forceps are clipped on the base of each
hemorrhoid and the pile is pulled out gently to expose the
apex, onto which a second forceps are clipped on. This produces
a triangular shape, called “triangle of exposure”
which marks out the shape of the tissue to be cut.
- Dissection
Starting at the wide base, the surgeon then dissects the
hemorrhoidal tissue slowly from the underlying sphincter
muscle. The wound is then dried, either by using diathermy
or cauterization by electricity, as well as with ligature
or suturing.
Care should be performed not to cut beyond the apex of this
triangle, as cutting above the dentate line is unnecessary
and may even cause post-operative narrowing of the anal
canal.
- Removal of the hemorrohidal mass
At the end of the dissection, three triangular-shaped wounds
are created with a wide base of approximately 1.0 cm. At
this time, the hemorrhoidal mass is still attached at the
apex, just above the dentate line. The excision of the hemorrhoid
mass is completed by first ligating the pedicle or stalk
with a fine surgical suture.
Although in many instances a ligation may not be required,
the surgeon may prefer to do it anyway since it does no
harm, and in some cases of large vessels, this prevents
post-operative bleeding.
At the end of this step, three dry and clean triangular
wounds are left, separated by three skin bridges of 2.0
cm width or more.
- Possible Complications:
- Residual hemorrhoids beneath the skin bridges
If there are only small numbers of hemorrhoids beneath
the skin bridge, they can be gently teased out and excised.
If there are numerous residual hemorrhoids underneath,
the skin bridge should be cut in two, and the piles
removed. Afterwards, the skin bridge is then sutured
together.
- Prolapsing
Excessively long and narrow skin bridge is prone to
prolapse, and therefore should be shortened by removing
a segment and resutured back together. If the prolapse
is not severe, a “hinge suture” can be used.
- Residual skin tag
After the removal of the hemorrhoids, skin tags should
be removed by slicing through their bases.
- Severe bleeding
In some patients, dissection is accompanied by severe
bleeding even after proper injection of vasoconstrictors
and multiple attempt to cauterize or perform multiple-ligations.
Although the bleeding can be stopped by application
of an anal pack, it works only temporarily and may cause
intense discomfort.
Instead, the wound should be closed with a suture and
a small roll of anti-septic soaked tissue should be
left in the anal canal to apply pressure to stop the
bleeding. This tissue can also be easily removed after
12 to 24 hours without any risk of bleeding re-starting
or undue pain.
In a minority case of patients with low anal tone, an
intra-anal dressing may be required to stop bleeding.
This is because in these patients, the anal canal does
not close properly and bleeding may recur. An antibiotic-moistened
anal plug can also be used during the postoperative
period.
Aftercare
At the end of the operation, a single layer of non-adhesive
gauze is used to dress the wounds. On top of these dressing,
a large absorbent pad (such as large-sized female sanitary
pads) is put over the anus to collect any discharge. Finally,
a large surgical dressing is applied to the buttocks and held
in place with a bandage.
Once the patient is taken down from the surgical position
and placed on a trolley, his or her buttocks should be squeezed
together to stop bleeding and prevent eh separation of the
dressing.
The wound dressings should not be changed for 24 hours, but
should be inspected from time to time to see whether bleeding
has occurred. Post-operative bleeding is normal, and may be
treated with a topical application of adrenaline solution.
Profuse bleeding or hemorrhage, however, should be treated
immediately and may require re-appraisal of the wound under
anesthesia.
One day after the surgery, the dressings are taken down and
the anal wounds are cleaned. The patient is encouraged to
bathe to keep his wound clean.
Restoration of defecation
Every patient dreads the pain associated with post-operative
bowel movement and some may even delay defecation (which would
increase constipation and make matters worse). Instead, the
doctor may prescribe frequent doses of magnesium salts to
encourage passage of liquid or semi-solid soft stool.
If defecation has not occurred after 3 days, a mini-enema
using a fine, well-lubricated tube should be used to initiate
bowel movement.
Daily passage of well-formed stool of regular size should
be the goal. This can be achieved by use of a bulking agent,
such as bran and fruits. Laxative use should be stopped.
The establishment of defecation is important to prevent anal
stenosis or an anal canal that opens too small or one that
does not relax and open properly. In this instances, the use
of a mechanical anal dilator or manual (finger) dilation of
the anal canal maybe necessary.
Complications
Open hemorrhoidectomy has the following possible complications:
- Postoperative bleeding or hemorrhage
If the surgery was carried out properly, postoperative bleeding
should be rare. Although significant bleeding should be
obvious, hidden bleeding into the rectum can also occur.
In case of the later, the only signs of bleeding may be
those of diminished blood volume (pallor, falling blood
pressure and rising pulse rate) as well as shock.
Bleeding from smaller blood vessels can be effectively treated
by gauze soaked in adrenaline solution. Large vessels may
need to be clipped and ligated.
- Secondary bleeding
In rare cases, infection of wounds around the ligature can
lead to profuse secondary hemorrhage or bleeding between
the seventh and sixteenth days after the surgery. In these
cases, the patient should be immediately admitted to the
hospital.
- Retention of urine
Inability to urinate is a common complication in male patients,
especially if they had anesthetics injected into the spine,
and can be treated by a fine, in-dwelling catheter. If the
patient has an enlarged prostate and does not respond to
catheterization, surgery may be required.
- Retention of feces
In most patients, fear of pain is the usual cause of hesitation
to defecate. This fear and anxiety should be addressed compassionately,
and laxative may be required to create an “irresistible”
bowel movement.
If the patient’s lack of bowel movement leads to fecal
accumulation in the rectum, a rectal and colon wash may
need to done. Usually, this procedure is carried our under
anesthesia. In cases of anal spasm contributing to fecal
retention, gentle anal dilation may be necessary.
- Fissure
If bowel movement is inadequate, or if an almost-healed
wound is split open by a hard stool, a fissure can occur.
This is usually treated by anal dilation under anesthesia
or by surgery.
- Fistula
If the ligation of the hemorrhoid stalk accidentally included
some muscle fibers, this may create an entry point of bacteria,
thus resulting in a fistula or the formation of an abnormal
tubular passage. Fistulas usually manifest themselves months
or even years after the hemorrhoidectomy, and may require
surgical treatments.
- Incontinence
This is usually not a risk associated with hemorrhoidectomy,
unless the patient has weak anal tone to begin with.
- Anal stenosis or narrowing of the anal canal
In this condition, the anal canal is narrowed or does not
open properly. If discovered early, anal dilation should
be sufficient to reverse the condition. Severe stenosis,
however, may require surgery.
- Recurrence of hemorrhoids
Approximately 5% of patients may require further treatments
by sclerotherapy or rubber band ligation.
Open hemorrhoidectomy vs. Closed
Hemorrhoidectomy
In another form of hemorrhoid surgery, called closed
hemorrhoidectomy or the Ferguson technique, the wound
from the excised hemorrhoidal tissue is sutured close (hence
the name).
Open hemorrhoidectomy or Milligan-Morgan technique is widely
used in the UK and Europe. Closed hemorrhoidectomy, which
is widely labeled as less painful, however, is more popular
in the United States, Asia, and South America. Nevertheless,
the exact difference in the level of pain between the two
procedures has not been confirmed by randomized trials.
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