Tuberculous peritonitis

Acute tuberculous peritonitis

Tuberculous peritonitis sometimes has an onset that resembles so closely acute peritonitis that the abdomen is opened. Straw-coloured fluid escapes and tubercules are seen scattered over the peritoneum and greater omentum. Early tubercles are greyish and translucent. They soon undergo caseation, and appear white or yellow and are then less difficult to distinguish from carcinoma. Occasionally they appear like patchy fat necrosis. On opening the abdomen and finding tuberculous peritonitis the fluid is evacuated, some being retained for bacteriological studies. A portion of the diseased omentum is removed for histological confirmation of the diagnosis and the wound closed without drainage.

At other times, although acute abdominal symptoms arise, the presence of ascites makes diagnosis of acute tuberculous peritonitis reasonably evident.

Chronic tuberculous peritonitis

Although the incidence of tuberculous peritonitis has declined in Britain, in many parts of the world where measures for eradicating tuberculosis (especially the disease in cows) are enforced less strictly, the condition still occurs. The condition presents with abdominal pain (90 per cent of cases), fever (60 per cent), loss of weight (60 per cent), ascites (60 per cent), night sweats (37 per cent) and abdominal mass (26 per cent).

Origin of the infection

Infection originates from:

 tuberculous mesenteric lymph nodes;

 tuberculosis of the ileocaecal region;

  a tuberculous pyo salpinx;

  blood-borne infection from pulmonary tuberculosis, usual­ly the ‘miliary’ but occasionally the ‘cavitating’ form.

Varieties of tuberculous peritonitis

There are four varieties of tuberculous peritonitis: ascitic, encysted, fibrous and purulent.

Ascitic form

The peritoneum is studded with tubercules and the peritoneal cavity becomes filled with pale, straw-coloured fluid. The onset is insidious. There is loss of energy, facial pallor and some loss of weight. The patient is usually brought for advice because of enlargement of the abdomen. Pain is often completely absent; in other cases there is considerable abdominal discomfort which may be associated with constipation or diarrhoea. On inspection, dilated veins can be seen coursing beneath the skin of the abdominal wall. Shifting dullness can be elicited readily. In the male child congenital hydroceles sometimes appear, due to the patent procesus vaginales becoming filled with ascitic fluid from the peritoneal cavity. Because of the increased intra-abdominal pres­sure an umbilical hernia commonly occurs. On abdominal palpation a transverse solid mass can often be detected. This is rolled-up greater omentum infiltrated with tubercules.

Diagnosis is seldom difficult except when it occurs in an acute form or when it first appears in an adult, in which case it has to be differentiated from other forms of ascites, espe­cially from malignant secondary deposits. A positive Mantoux test in a child with ascites strongly suggests, and a negative test is good evidence against, tuberculosis. In adults this test is of negligible value. Laparoscopy is useful by allowing inspection of the peritoneal cavity, where the appearance is often diagnostic. Areas of caseation can be biopsied for histology and microbiological studies. The ‘open’ (Hassan) technique of trocar insertion should be used because of the risk of adhesions to the abdominal wall. The diagnosis of tuberculous peritonitis having been made, it is always impor­tant to look for tuberculous disease elsewhere. The possibility of tuberculous salpingitis in females should be remembered. A chest X-ray should always be taken before laparoscopy or laparotomy is performed.

The ascitic fluid is pale yellow, usually clear and rich in lymphocytes. The specific gravity is comparatively high, often 1.020 or over. Even after centrifugation, rarely can M. tuberculosis be found, but its presence can be demonstrated by culture or by guinea-pig inoculation.

Treatment. See guidelines, Chapter 8. If the general condition is good, the patient can return home and, if an adult, to light work, before the course of chemotherapy has been completed.

Encysted form

Encysted (syn. loculated) form is similar to the above, but one part of the abdominal cavity alone is involved. Thus, a localised intra-abdominal swelling is produced which gives rise to difficulty in diagnosis. In a female above the age of puberty when the swelling is in the pelvis, an ovarian cyst will probably be diagnosed. In the case of a child it is sometimes difficult to distinguish the swelling from a mesenteric cyst. For these reasons laparotomy is often performed, and if an encapsulated collection of fluid is found, it is evacuated and the abdomen is closed. The general treatment already detailed is required, but the response to this treatment is more rapid. Late intestinal obstruction is a possible complication.

Fibrous form

Fibrous (syn. plastic) form is characterised by the production of widespread adhesions, which cause coils of intestine, especially the ileum, to become matted together and distended. These distended coils act as a ‘blind loop’ and give rise to steatorrhoea, wasting and attacks of abdominal pain. On examination, the adherent intestine with omentum attached, together with the thickened mesentery, may give rise to a pal­pable swelling or swellings. The first intimation of the disease may be subacute or acute intestinal obstruction. Sometimes the cause of the obstruction can be remedied easily by the division of bands. Lateral anastomosis between an obviously dilated loop and a collapsed loop of small intestine should not be done, as the ‘blind loop’ syndrome is a certain out­come. If the adhesions are accompanied by fibrous strictures of the ileum as well it is best to excise the affected bowel, provided not too much of the small intestine needs to be sacrificed. If adhesions only are present a plication may be performed (see Chapter 58). Chemotherapy after adequate surgery will rapidly cure the condition.

Purulent form

The purulent form is rare. When it occurs, usually it is secondary to tuberculous salpingitis. Amidst a mass of adherent intestine and omentum, tuberculous pus is present. Sizeable cold abscesses often form, and point on the surface, commonly near the umbilicus, or burst into the bowel. In addition to prolonged general treatment, operative treatment may be necessary for the evacuation of cold abscesses and possibly for intestinal obstruction. If a faecal fistula forms it usually persists because of distal intestinal obstruction. Closure of the fistula must therefore be combined with some form of anastomosis between the segment of intestine above the fistula and an unobstructed area below. The prognosis of this variety of tuberculous peritonitis is relatively poor.

Peritoneal bands and adhesions

Congenital bands and membranes. Congenital bands and membranes occur in the peritoneum at various sites as described in textbooks of anatomy. Intestinal obstruction is rarely seen except by an obliterated vitellointestinal duct.

Peritoneal adhesions. Peritoneal adhesions are abnormal deposits of fibrous tissue that form after peritoneal injury. They follow operation or peritonitis and are the commonest cause of small bowel obstruction and secondary female infertility in developed countries. They are discussed in detail in Chapter 58.

Talc granuloma. Talc (silicate of magnesium) should never be used as a lubricant for rubber gloves for it is a cause of peritoneal adhesions and granulomas in the Fallopian tubes. Potassium bitartrate which is completely soluble is free from these serious complications.

Starch peritonitis. Like talc, starch powder has found disfavour as a surgical glove lubricant. In a few starch-sensitive patients it causes a painful ascites, fortunately of limited duration. Should laparotomy be performed any small granulomas in, say, the omentum will be found to contain birefringent starch particles. Starch-free surgical gloves are now widely available