The ascitic type of abdominal tuberculosis

In Africa, about 70% of patients with abdominal tuberculosis present with ascites; in India only about 10% of them do. In Zambia tuberculosis is responsible for 20% of all cases of ascites. The patient presents with a swollen abdomen containing many litres of straw-coloured fluid. A child with advanced abdominal tuberculosis typically has ''a ballooned abdomen and matchstick legs', but in many children the diagnosis is far from obvious. The fluid accumulates as the result of large numbers of miliary tubercles on his peritoneum. The only certain way to make the diagnosis is to do a minilaparotomy (''minilap'), which will also enable you to diagnose cirrhosis, periportal fibrosis (due to Schistosomiasis mansoni), carcinomatosis of the peritoneum and hepatoma (usually with cirrhosis). Experts can usually diagnose miliary tuberculosis with their naked eyes; but even they can be wrong, so take a biopsy of his parietal peritoneum and/or his liver.

Fig. 29-6 ASCITIC ABDOMINAL TUBERCULOSIS. A, the minilap incision. B, draw off the fluid slowly before you start. C, miliary tubercles of the parietal peritoneum, liver, and gut.

ASCITIC ABDOMINAL TUBERCULOSIS SPECIAL TESTS. X-ray the patient's chest, and examine his ascitic fluid. If the cell count is over 50 [gm]l, with at least 70% lymphocytes, he is fairly likely to have tuberculous peritonitis. Your lab will be unlikely to find AAFB in it, because they are very sparse. If the fluid has fewer lymphocytes than this, his ascites is more likely to be caused by cirrhosis, or periportal fibrosis.

Measure the protein in his peritoneal fluid. In tuberculous peritonitis it is usually 3 to 10 g/l, but it may be up to 20 g/l, or higher. Most patients with [mt]20 g/l, or more, have carcinomatosis.

If it contains more than 4 g/l of protein, it is likely to be an exudate. If it contains less than 4 g/l, it is likely to be a transudate. Cirrhosis usually produces a transudate; so does periportal fibrosis, if it produces any fluid at all (uncommon).

Blood in the fluid suggests carcinomatosis or a hepatoma.

THE DIFFERENTIAL DIAGNOSIS of ascitic tuberculous peritonitis (for the plastic type see later):

Suggesting ascitic tuberculosis[md]miliary nodules on the peritoneum, each about 1 to 2 mm in size, slightly raised and whitish. The nodules of carcinomatosis, which is the main differential diagnosis, are larger[md]usually more than 3 mm[md]more vascular, and more irregular. You will soon learn to distinguish them. He is not as ill as he would be with a malignant effusion of the same size.

Suggesting ascites secondary to liver disease[md]his liver may be enlarged, hard, and irregular, or small and hard to feel; his spleen is usually large; there are usually [lt]4 g/l of protein in his peritoneal fluid.

Suggesting the nephrotic syndrome[md]his ascites is less marked than his generalized oedema. If he has ascites, he usually also has marked ascites of his abdominal wall. There are usually [lt]4 g/l of protein in his peritoneal fluid.

Suggesting nutritional oedema (hypoproteinaemia)[md]other signs of protein deficiency, but these may also be present in tuberculosis. There are usually [lt]4 g/l of protein in his peritoneal fluid.

Suggesting heart failure leading to cirrhosis and ascites[md]a raised jugular venous pressure, and other signs of heart failure; [lt]4 g/l of protein in his peritoneal fluid.

Suggesting carcinomatosis of the peritoneum[md]hard deposits in the pouch of Douglas or rectovesical pouch; usually [mt]20 g/l of protein in his peritoneal fluid.

A MINILAP [s7]TO DIAGNOSE THE CAUSE OF ASCITES INDICATIONS. Ascites of uncertain cause. In the developing world, especially, a patient can have more than one diagnosis, for example, cirrhosis and tuberculosis peritonitis. Ascites predominating over other signs usually requires a minilap. It is seldom indicated when the ascites is not predominant, as in the generalized oedema of heart failure, or renal disease. Check his blood urea before you proceed.

CAUTION! ! (1) A minilap is NOT suitable for exploring the abdomen. (2) You can diagnose tuberculous abdominal glands this way, but they are better biopsied elsewhere, for example in his axilla.

DRAINING THE ASCITES. If he has more than a mild ascites, draw off most of the ascitic fluid slowly before you begin. If it all escapes suddenly, as you open his abdomen, his circulation may collapse. So draw off one litre every 2 hours, starting 48 hours preoperatively, to a maximum of 6 litres. If there is still significant ascites, after you have withdrawn 6 litres, wait until next day before you draw off more. Use a wide-bore intravenous cannula, a drip set, and a sterile bottle.

CAUTION ! To avoid possible injury to a large spleen, which may be difficult to feel because of the ascites, drain the fluid from his right lower abdomen.

ANAESTHESIA. Use local anaesthesia in an adult or ketamine in a child. Avoid general anaesthesia, because he may have cirrhosis.

INCISION. Make a 5 to 6 cm right upper muscle-splitting paramedian incision 4 or 5 cm from the midline. This will allow you to see and examine his liver, and will be less likely than a midline incision to leak ascitic fluid postoperatively.

Look for miliary tubercles and secondary deposits on his peritoneum. Tubercles are remarkably uniform in size, and fairly uniform in appearance (like salt grains). Take a biopsy from his parietal peritoneum. Take a needle biopsy of his liver under direct vision, if this is indicated (32.26), or take a wedge biopsy. Close the incision in the usual way, but don't insert a drain, or it will leak continuously.

TO BIOPSY HIS PERITONEUM remove an elliptical piece of his parietal peritoneum 2[mu]0.5 cm, from the edge of the abdominal incision. This is only necessary if it is abnormal macroscopically.

WEDGE BIOPSY [s7]OF THE LIVER INDICATIONS. The histological examination of any suspicious lesion in the liver.

METHOD. Insert 2 ''0' chromic catgut atraumatic sutures near the anteroinferior border of his liver, as in Fig. 29-7. Tie these so as to ''squeeze' his liver, adjacent to the segment you are going to incise, to stop it bleeding. Remove a wedge of his liver 0.5[mu]1.5 cm. Bring the cut edges of his liver together with two more mattress sutures, placed transverse to, and outside, the first two.

TREATMENT [s7]FOR ASCITIC TUBERCULOSIS Give him chemotherapy. Don't expect miracles, if he has acute disease and ascites. Before 2 months, the failure of the fluid to reaccumulate will show that he is improving.

Fig. 29-7 WEDGE BIOPSY OF THE LIVER. A, insert sutures to control bleeding before you cut the liver. B, the wedge excised. C, the wedge closed.