Appendicectomy
Appendicectomy may be performed by
conventional open operation or by using laparoscopic techniques. The first
surgeon to perform deliberate appendicectomy for acute appendicitis was Lawson
Tam, in May 1880. The patient recovered. It is recorded in 1736 that Claudius
Amyand successfully removed an acutely inflamed appendix from the hernial sac of
a boy.
Appendicectomy
should he performed under general anaesthetic with the patient supine on the
operating table. When a laparoscopic technique is to be used, a nasogastric tube
should be inserted and the bladder must be empty (ensure the patient has voided
before leaving the ward). Prior to preparing the entire abdomen with an
appropriate antiseptic solution, the right iliac fossa should be palpated for a
mass. If a mass is felt, it may, on occasion, be preferable to adopt a
conservative approach (vide infra). Draping
of the abdomen is in accordance with the planned operative technique, taking
account of any requirement to extend the incision or convert a laparoscopic
technique to open operation.
Conventional
appendicectomy
When the preoperative diagnosis is considered
reasonably certain, the incision that is widely used for appendicectomy is the
so-called grid-iron incision (a
grid-iron was a frame of cross-beams to support a ship during repairs). The
grid-iron incision (described first by McArthur) is made at right angles to a
line joining the anterior superior iliac spine to the umbilicus, its centre
being along the line at McBurney’s point
(Fig. 59.12). In the subcutaneous tissues an
arterial twig from the superficial circumflex iliac artery usually requires
ligation. The external oblique is incised in the line of its fibres along the
length of the incision. The fibres of the internal oblique and transversus
abdominis are split, and with suitable retraction the peritoneum is opened. If
better access is required, it is possible to convert the grid-iron to a
Rutherford Morrison incision (vide
infra) by
cutting the internal oblique and transversus muscles in the line of the
incision.
In
recent years, a transverse skin crease (Lanz)
incision has become more popular, as the exposure is better and extension,
when needed, is easier. The incision, appropriate in length to the size and
obesity of the patient, is made approximately 2 cm below the umbilicus centred
on the midclavicular—midinguinal line (Fig. 59.13). The external oblique
aponeurosis, internal oblique and transversus muscles are split in the direction
of the fibres and the peritoneum is opened. When necessary the incision may be
extended medially, with retraction or suitable division of the rectus abdominis
muscle.
When
the diagnosis is in doubt, particularly in the presence of intestinal
obstruction, a lower midline abdominal incision is to be preferred over a right
lower paramedian incision. The latter, although widely practised in the past, is
difficult to extend, more difficult to close and provides less good access to
the pelvis and peritoneal cavity.
Rutherford Morrison’s incision is useful if the appendix
is paracaecal or retrocaecal and fixed. It is
essentially an oblique muscle-cutting incision with its lower end over
McBurney’s point and extending obliquely upwards and laterally as necessary.
All layers are divided in the line of the incision.
Removal of the appendix
It will be assumed that the abdomen has been
opened by a skin crease incision. A retractor is placed under the medial side of
the wound and the peritoneum, and the abdominal wall is elevated. Serous exudate
is removed with a sucker. Pus, if present, is likewise removed having first
retained a specimen for microbiological culture. The caecum is identified by the
presence of teniae coli, and using a finger or a swab the caecum is withdrawn. A
turgid appendix may be felt at the base of the caecum. Inflammatory adhesions
must be gently broken with a finger which is then hooked around the appendix to
deliver it into the wound. The appendix is conveniently controlled using a
Babcock or Lane’s forceps applied in such a way as to encircle the appendix
and yet not damage it. The base of the mesoappendix is clamped in a haemostat,
divided and ligated (Fig. 59.14a). When the mesoappendix is broad the procedure
must be repeated with a second, or rarely, a third haemostat. The appendix, now
completely freed, is crushed near its junction with the caecum in a haemostat,
which is removed and reapplied just distal to the crushed portion. An absorbable
2/0 ligature is tied around the crushed portion close to the caecum. The
appendix is amputated between the haemostat and the ligature (Fig.
59.14b). An
absorbable 2/0 or 3/0 purse-string
Methods to be
adopted in special circumstances
When the caecal wall is oedematous, the
purse-string suture is in danger of cutting out. If the oedema is of limited
extent this can be overcome by inserting the purse-string suture into more
healthy caecal wall at a greater distance from the base of the appendix.
Occasions may arise when, because of the extensive oedema of the caecal wall, it
is better not to attempt invagination.
When
the base of the appendix is inflamed, it should not be crushed but ligated close
to the caecal wall just tightly enough to occlude the lumen, after which the
appendix is amputated and the stump invaginated. Should the base of the appendix
be gangrenous, neither crushing nor ligation must be attempted. Two stitches are
placed through the caecal wall close to the base of the gangrenous appendix,
which is amputated flush with the caecal wall, after which these stitches are
tied. Further closure is effected by means of a second layer of interrupted
seromuscular sutures.
Retrograde appendicectomy
When the appendix is retrocaecal and adherent,
it is an advantage to divide the base between haemostats. The appendiceal
vessels are then ligated, the stump is ligated and invaginated, and gentle
traction on the caecum will enable the surgeon to deliver the body of the
appendix which is then removed from base to tip. Occasionally, this manoeuvre
requires division of the lateral peritoneal attachments of the caecum.
Drainage of the peritoneal cavity
This is usually unnecessary provided adequate
peritoneal toilet has been done. If, however, there is considerable purulent
fluid in the retrocaecal space or the pelvis, a soft silastic drain may be
inserted through a separate stab incision. The wound should be closed using
absorbable sutures to oppose muscles and aponeurosis. In the presence of soiling
or if a gangrenous appendix has been delivered through the wound, it is often
wise to leave open or to delay primary closure by inserting a gauze wick between
interrupted skin sutures (Brady) (Fig.59.15).
Laparoscopic
appendicectomy
The most valuable aspect of laparoscopy in the
management of suspected appendicitis is as a diagnostic tool, particularly in
women of child-bearing age. In general, an open technique should be used to
establish a pneumoperitoneum, and for insertion of the laparoscopic ports as it
is safer than the closed techniques using a Verres needle. The placement of the
operating port may vary according to operator preference and previous abdominal
scars. The operator stands to the patient’s left and faces a video monitor
placed at the patient’s right foot (Fig. 59.16). A moderate Trendelenberg tilt of the operating
table assists delivery of loops of small bowel from the pelvis. The appendix is
found in the conventional manner
by identification of the caecal taeniae and is
controlled using laparoscopic tissue-holding forceps. By elevating the appendix
the mesoappendix is displayed (Fig. 59.17a). A dissecting forceps is used to
create a window in the mesoappendix to allow the appendicular vessels to be
coagulated or ligated using a clip applicator. The appendix, free of its
mesentery, can be ligated at its base with an absorbable loop ligature (Fig.
59.17b), divided (Fig. 59.17c) and removed through one of the operating ports.
It is not usual to invert the stump of the appendix (Fig.
59.17d). A single
absorbable suture is used to close the linea alba at the umbilicus and the small
skin incisions may be closed with a subcuticular suture (Fig.
59.18).
Patients
who undergo laparoscopic appendicectomy are likely to be discharged from
hospital and return to work slightly sooner than those who have undergone open
appendicectomy, but it remains to be seen whether this justifies the slightly
longer operating time and higher costs involved.
Problems
encountered during appendicectomy
• A normal appendix is found — this demands careful exclusion of other possible
diagnoses, particularly terminal ileitis, Meckel’s diverticulitis and tubal or
ovarian causes in women. It is usual to remove the appendix to avoid future
diagnostic difficulties, even though the appendix is macroscopically normal,
particularly if a skin crease or grid-iron incision has been made. A case can be
made for preserving the macroscopically normal appendix seen at diagnostic
laparoscopy, although approximately a quarter of seemingly normal appendices
show microscopic evidence of inflammation.
• The appendix cannot be found — the caecum should he mobilised and the taenia
coli should be traced to their confluence on the caecum before the diagnosis of
‘absent appendix’ is made.
•
An appendicular tumour is found —
small tumours (under 2.0 cm in diameter) can he removed by appendicectomy;
larger tumours should he treated by a right hemicolectomy.
• An appendix abscess is found and the appendix cannot he removed easily — this
should be treated by local peritoneal toilet, drainage of any abscess and
intravenous antibiotics. Very rarely a caecectomy or partial right hemicolectomy
is required. (The first recorded operation for an appendix abscess was by Henry
Hancock of Charing Cross Hospital, London, in 1848.)
Appendicitis
complicating Crohn’s disease
Occasionally, a patient is operated on for
acute appendicitis who is found to have concomitant Crohn’s disease of the
ileo-caecal region. Providing the caecal wall is healthy at the base of the
appendix, appendicectomy can he performed without increasing the risk of an
enterocutaneous fistula. Rarely, the appendix is involved with the Crohn’s
disease. In this situation a conservative approach may be warranted, and a trial
of intravenous corticosteroids and systemic antibiotics used to resolve the
acute inflammatory process.
Appendix
abscess
Failure of resolution of an appendix mass or
continued spiking pyrexia usually indicates that there is pus within the
phlegmonous appendix mass. Ultrasound or abdominal CT scan may identify an area
suitable for insertion of a percutaneous drain. Should this prove unsuccessful,
laparotomy through a midline incision is indicated.
Pelvic abscess
Pelvic abscess formation is an occasional
complication of appendicitis and can occur irrespective of the position of the
appendix within the peritoneal cavity. The most common presentation is a spiking
pyrexia several days following appendicitis; indeed the patient may have already
been discharged from hospital. Pelvic pressure or discomfort associated with
loose stool or tenesmus is common. Rectal examination reveals a buggy mass in
the pelvis, anterior to the rectum, at the level of the peritoneal reflection (Fig.
59.19). Pelvic ultrasound or CT scan will confirm. Treatment is
transrectal drainage under general anaesthetic.