Key Clinical Message
Colonic decompression, appendicectomy and post operative antiviral
therapy for CMV colitis/ megacolon and appendicitis complicating AIDS is
effective and avoids the morbidity and high mortality from an emergency
subtotal colectomy and ileostomy.
INTRODUCTION
Abdominal pain is common in HIV/ AIDS and is caused by gastrointestinal
malignancies and opportunistic infections. Cytomegalovirus infection
(CMV) is the commonest cause resulting in a wide range of conditions
including oesophagitis, acalculous cholecystitis, sclerosing
cholangitis, small bowel perforation, toxic megacolon, colonic
perforation and haemorrhage from mucosal ulcerations (figure 1), and
spontaneous rupture of the spleen [1-3]. In the tropics such as
Africa, India and the Far East, most infection takes place in infancy or
early childhood by reactivated virus in its mother’s genital tract
during delivery, or from her milk. These have not been associated with
severe symptoms and the infants have the opportunity of developing
immunity. Disease caused by CMV was first brought to notice by the
congenitally infected infants of more likely women in western temperate
climates than those in tropical climates [4] Soon afterward its
importance was recognized in immunodeficiency diseases or on
immunosuppressive drugs. Similar to other herpes viruses (herpes
simplex viruses 1 and 2, Epstein-barr virus, varicellar zoster virus )
CMV lies latent after an acute infection and may reactivate at time of
stress or immunosuppression to become a more serious infection.
Lymphocytosis and lymphadenopathy are less frequent than in the Epstein-
Barr virus (EBV) glandular fever. The determination of different classes
of antibody may give an indication of the likely time of CMV infection
in a particular case [4]. Although virus isolation is difficult and
cannot be a rapid method of diagnosis as the growth of the virus is
slow, CMV has been isolated from appendix specimens. This raises the
possibility that CMV may be causative or a co-factor [5]. Toxic
megacolon is a severe attack of colitis with total or segmental
dilatation of the colon with the diameter of the transverse colon
usually greater than 5 -6 cm. A possible pathophysiological mechanism is
the destruction of the myenteric plexus and muscle propria of the colon
by inflammatory mediators [6-8]. Appendicectomy and colectomy are
thus, the commonest abdominal operations in HIV/AIDS patients. As a
presenting AIDS diagnosis and the general health status indicated by the
American Society of Anaesthesia (ASA) score to withstand major surgery
especially in the face of major abdominal sepsis are the two factors
most associated with surgical outcome, careful patient selection for
emergency laparotomy is necessary to achieve worthwhile palliation
[9].
CASE HISTORY/ EXAMINATION
A 33-year- old African man was admitted as an emergency with a history
of a gradual onset generalised colicky abdominal pain of two days
duration. This was associated with abdominal distension, two episodes of
postprandial vomiting and fever. He had no altered bowel habit but the
abdominal pain had become constant and more severe with no exacerbating
nor relieving factors. He was an HIV- infected patient but not compliant
with highly active anti- retroviral treatment (HAART). On physical
examination, he was alert but lethargic, ill-looking, and clinically
dehydrated. The vital signs revealed tachycardia (119 beats/min),
tachypnoea (20 breaths/min) and pyrexia (38.30 C)and a
normal blood pressure (130/88 mmHg). There was no lymphadenopathy and
the chest and cardiovascular examination were unremarkable. He had gross
abdominal distension with board-like rigidity, guarding and rebound
tenderness in the right iliac fossa overlying McBurney’s point. The
percussion note was tympanic and bowel sounds were hypoactive. Rectal
examination was normal. A plain abdominal x-ray (figure 2) showed
dilated large bowel and an erect chest x-ray showed no pneumoperitoneum.
Apart for a thrombocytopaenia of 104 x 103 /ml (n:
150-400 x 103 /ml, the full blood count and serum
biochemistry were within normal limits. The differential diagnosis
included a perforated acute appendicitis with associated ileus .
Following resuscitation with intravenous fluids and broad spectrum
antibiotics he underwent a laparotomy. Intraoperatively, there was no
free fluid in the peritoneal cavity but a grossly dilated colon
(~ 5cm d) extending to the rectum with
no signs of imminent perforation. The appendix appeared abnormally long
, oedomatous and inflammed (figure 2). Decompression of the colon per
anum with a sigmoidosocpe revealed copious purulent necrotic, mucus
fluid. These findings were consistent with a toxic megacolon and acute
appendicitis complicating an infective (CMV) colitis. An appendicectomy
was done (figure 3) and a decompressing Foley catheter tube left in-situ
to allow continuous drainage. Due to limited resources a histopathology
report on the appendix specimen could not be sought. He was commenced on
the anti-viral acyclovir 200mg tds, the 1stpost-operative day and following an episode of massive rectal bleeding
on the 2nd postoperative day the symptoms and signs of
toxic megacolon rapidly improved. He was recommenced on HAART and
discharged on the 10th day post operation with no
wound complications. He was clinically well at 6 weeks follow-up.
DISCUSSION
Pathology occurring in HIV/AIDS patients may be classified into (a)
diseases with a definitive association with HIV and (b) coincidental
diseases seen in the general population especially as HIV/AIDS patients
on HAART are living longer. The commonest presentation in AIDS requiring
laparotomy are toxic megacolon, small bowel obstruction and localized
peritonitis [1, 9]. The commonest disease processes, CMV colitis,
B-cell lymphoma, acute appendicitis with CMV infection and atypical
mycobacterium avium intracellulare (MAI) infection are quite different
from that seen in the non- HIV population [1, 9, 10]. The case
demonstrates a good clinical outcome following early intervention on an
HIV/AIDs patient with most probable toxic CMV colitis and appendicitis.
The patient benefited from an appendicectomy and sigmoidoscopic
decompression of the toxic megacolon. The presumptive diagnosis of a CMV
colitis complicating AIDS was corroborated by its response to
post-operative anti- viral (acyclovir) treatment [11]. The morbidity
and reported high 30 day mortality (71%) from an emergency sub-total
colectomy and an ileostomy in these patients were avoided [12]. It
is important to note that although abdominal pain is common in patients
with AIDS, less than 1% of patients will need an emergency laparotomy
[10]. Lymphadenopathy from MAI or lymphoma can result in
appendicitis or jaundice by obstructing the appendiceal ostium or porta
hepatis, respectively. These patients are often difficult to manage as
it is often unclear if they need an immediate laparotomy. Patients may
also present with less severe abdominal pain from cryptosporidial
infection of the gut and a few with CMV, that does not amount to an
emergency, and up to a third of patients in whom no associated
infections are uncovered [13]. It is important to have close liason
with the AIDS physicians to exclude pre-terminal cases and keep down
negative laparotomies to acceptable rate [13, 14]. Because negative
laparotomy is not too infrequent for a patient with undiagnosed
abdominal pain, there is increased indication for diagnostic
laparoscopy. Care should, however, be taken during laparoscopy by using
disposable ports with a vestibular flange to prevent splash back, and by
deflating the abdomen prior to port withdrawal because any aerosol
emanating from the port entry wound will harbor HIV [1, 13, 14].
Perioperative deaths commonly occur in HIV/AIDS patients with
generalized peritonitis especially as general anaesthesia results in
depression of cell-mediated immunity and AIDS progression [1, 10].
The current lower operative mortality for emergency surgery on AIDS
patients (11% in one series) may be due to early intervention before
colonic perforation ensues and active treatment at every level [10].
Also this case demonstrates that a colonic decompression and an
appendicectomy plus post operative viral CMV treatment may suffice in
treating CMV toxic colitis with megacolon [11, 15]. Although
gastrointestinal involvement with CMV infection is uncommon in
immunocompetent patients, similar case reports on immunocompetent
patients using a similar treatment approach except for appendicectomy
yielded similar outcome [ 11, 15-17].The adjuvant treatment with
HAART would improve the general resistance to infection and
nutritionally status [18]. Later deaths are due to the progression
of AIDS [10]. Surgery confers least benefit in patients with acute
abdominal pain from MAI infection or lymphoma because of the higher
degree of immunosuppression (<200 CD4 cells/ul ) [3, 10,
19]. As HIV/AIDS patients are not homogeneous, surgical intervention
in selected patients for life-threatening surgical correctable disease
as appendicitis or refractory toxic megacolon is justifiable [1, 9].
However, the pathophysiological consequences of advanced disease
(immunosuppression, malnutrition, infections and neoplasms) requires the
scaling down of the magnitude of surgery to an acceptable and safe
level.
CONCLUSIONS
Early suspicion and diagnosis of CMV colitis in HIV/AIDS is essential as
early conservative anti-viral treatment may prevent the potentially
fatal complication of toxic megacolon or massive haemorrhage. Otherwise,
colonic decompression of the toxic megacolon and an appendicectomy for
the usually associated CMV appendicitis should have minimal morbidity
and mortality.