The mucous membrane and submucosa of the rectum protrude
In infants
The direct downward course of the rectum, due
to the as yet undeveloped sacral curve (Fig. 60.9), predisposes to this condition,
as does the reduced resting anal tone which offers diminished support to the
mucosal lining of the anal canal (Mann).
In children
Partial prolapse often commences after an
attack of diarrhoea, as a result of severe whooping cough, or from loss of
weight and consequent diminution in the amount of fat in the ischiorectal fossae.
In adults
The condition in adults is usually associated
with third-degree haemorrhoids. In the female, a torn perineum predisposes to
prolapse, and in the male straining from urethral obstruction. In old age, both
partial and complete prolapse are associated with atony of the sphincter
mechanism but whether this is the cause of the problem or secondary to it is
unknown.
Partial
prolapse may follow an operation for fistula-in-ano where a large portion of
muscle has been divided. Here the prolapse is usually localised to the damaged
quadrant and is seldom progressive.
Prolapsed
mucous membrane is pink; prolapsed internal haemorrhoids are plum coloured and
more pedunculated.
Treatment
In infants and young children
Digital reposition. The parent must be taught
to replace the protrusion. The distal two-thirds of the index finger is wrapped
in tissue paper. The finger is inserted into the protrusion and the mass is
eased into place. Gently, the finger is withdrawn, leaving the tissue paper to
disintegrate. In cases of malnutrition, dietetic adjustments are necessary.
Submucous
injections. If digital reposition fails after 6 weeks’ trial, injections of 5
per cent phenol in almond oil are carried out under general anaesthesia. As
a result of the aseptic inflammation following these injections, the mucous
membrane becomes tethered to the muscle coat.
Technique.
The submucosa at the apex of the prolapse is injected circularly, so as to form
a raised ring, up to 10 ml of the solution being injected. A similar injection
is made at the base of the prolapse. Alternatively, if the prolapse cannot be
brought down, the injections are given through a proctoscope.
Thiersch’s
operation. When the prolapse persists in spite of these measures, Thiersch’s
operation (below) may succeed. In infants, insertion of the little finger into
the anus before the stitch is tied is recommended. In infants and young
children, strong chromic catgut should be used for the stitch instead of silver
wire: if wire were employed (or any other retained unabsorbable material) as
growth proceeded, the stitch would have to be removed or anal stenosis would
result. As the procedure is designed only as a temporary
measure in the young, chromic catgut is adequate for the purpose.
In adults
Submucous injections. Submucous injections of
phenol in almond oil occasionally are successful in cases of early partial
prolapse.
Excision
of the prolapsed mucosa. When the prolapse is
Complete
prolapse
Complete prolapse (syn. procidentia) is less
common than the partial variety. The protrusion consists of all layers of the
rectal wall and is a descending hernia-en-glissade of the rectum downwards
through the levator ani. As the rectum descends, it intussuscepts upon itself.
The process starts with the anterior wall of the rectum where the supporting
tissues are weakest, especially in women. It is more than 4 cm and commonly as
much as 10—15 cm in length. On palpation between the finger and the thumb, the
prolapse feels much thicker than a partial prolapse, and obviously consists of a
double thickness of the entire wall of the rectum. Any prolapse over 5
cm in length contains anteriorly between its layers a pouch of peritoneum (Fig.
60.11). When large, the peritoneal pouch contains small intestine, which
returns to the general peritoneal cavity with a characteristic gurgle when the
prolapse is reduced. The prolapsed mucous membrane (Fig.
60.12) is often
arranged in a series of circular folds. The anal sphincter is characteristically
patulous and gapes widely on straining to allow the rectum to prolapse. Complete
prolapse is uncommon in children. In adults, it can occur at any age, but is
more common in the elderly. Women are six times more often affected than men. In
women, prolapse of the rectum is commonly associated with prolapse of the
uterus, or a past history of a gynaecological operation, e.g. hysterectomy. In
the Middle East and Asia, complete rectal prolapse is not uncommon in young
males. In approximately 50 per cent of adults, faecal incontinence is also a
feature .bifferential diagnosis. In the case of a child with abdominal pain,
prolapse of the rectum must be distinguished from ileocaecal
intussusception protruding from the anus. Figures 60.13 and
60.14 make the
differential diagnosis clear. In rectosigmoid
intussusception in the adult, there is a deep groove (5
cm or more) between the emerging protruding mass and margin of the anus,
into which the finger can be entered.
Treatment
Surgery is required and the operation can be
performed via the perineal or the abdominal approaches. Whenever possible, an
abdominal rectopexy is recommended, but when the patient is elderly and very
frail, or is suffering from injury or disease of the spinal cord, or in very
early life, a perineal operation is indicated.
Perineal
approach. Two procedures have been used most commonly.
Delorme’s operation (Fig. 60.15).
In this
procedure, the rectal mucosa is removed circumferentially from the prolapsed
rectum over its length, apart from 0.5-cm strips at its proximal end and at its
tip. The underlying muscle is then imbricated with a series of chromic catgut
sutures, such that, when these are tied, the rectal muscle is concertinaed
towards the anal canal. The anal canal mucosa is then sutured circumferentially to the rectal mucosa
remaining at the tip of the prolapse. This manoeuvre has the effect of reducing
the prolapse and creating a ring of muscle within the anal canal, which narrows
the orifice and prevents recurrence.
Thiersch's
operation. This procedure, which aims to place a steel wire or,
more commonly now, a silastic or nylon suture, around the anal canal has in the
past been the most frequently performed perineal procedure. However, it has
become obsolete for the treatment of rectal prolapse in adults, although it
still does have a place in the treatment of partial prolapse in children. The
reasons for its lack of popularity are that the suture would often break or
cause chronic perineal sepsis, or both, or the anal stenosis so created would
produce severe functional problems. Delorme’s operation is now the preferred
perineal operation.
If
an abdominal repair must he avoided (e.g. in a young man in whom sexual potency
must be preserved by avoiding damage to the pelvic nerves) more extensive
perineal procedures are available. These include strengthening the puborectalis
and external anal sphincters by an approach through the intersphincteric plane
(see above), the so-called postanal repair
(Parks) and perineal rectosigmoidectomy (Altemeier) in which the prolapsed
rectum is exised from below.
Abdominal
approach. The principle of all abdominal operations for rectal prolapse is to
replace and hold the rectum in its proper position. Of the many operations
described, the following are relatively simple. They are recommended in patients
with complete prolapse, who are otherwise in good health.
Wells’ operation. In this operation the rectum is fixed firmly to the sacrum by inserting
a sheet of polyvinyl alcohol sponge or, more commonly now, polypropylene mesh
between them (Fig. 60.16). The rectum is separated from the sacrum in the Lisual
way. The mesh is fixed by a series of sutures to the periosteum over the midline
of the sacrum and is then wrapped loosely about the rectum covering all except
the anterior wall. The free margins of the mesh are sutured to the lateral
Ripstein’s operation. In this operation, the rectosigmoid junction is
hitched up by a Teflon sling to the front of the sacrum just below the sacral
promontory. The operation is very safe and simple, and the results are good.
Some surgeons recommend combining this procedure with resection of the sigmoid
colon (Goldberg).