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:

1. 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.
   
   
2. 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.
   
   
3. 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:

1. 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.
   
   
2. 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.
   
   
3. 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.
   
   
4. 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.
   
   
5. 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.
   
   
6. 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:

1. 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.
   
   
2. 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.
   
   
3. 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.
   
   
4. 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.
   
   
5. 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.
   
   
6. 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.
   
   
7. Incontinence
   This is usually not a risk associated with hemorrhoidectomy, unless the patient has weak anal tone to begin with.
   
   
8. 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.
   
   
9. 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.