ABDOMINAL TUBERCULOSIS

Abdominal tuberculosis can be divided into

·         Tuberculous peritonitis and

·         Tuberculosis of the intestine.

TUBERCULOUS PERITONITIS

Acute tuberculous peritonitis

                                                  Tuberculous peritonitis sometimes has an onset that so closely resembles acute peritonitis that the abdomen is opened. Straw coloured fluid escapes and tubercles 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. On opening the abdomen and finding tuberculous peritonitis, the fluid is evacuated, some being retained for histological studies. A portion of diseased omentum is removed for histological confirmation of the diagnosis and the wound closed without drainage.

 

Chronic tuberculous peritonitis

                                                        The condition presents with abdominal pain (90% of cases), fever (60%),          weight loss (60%), ascites(60%), night sweats (37%) and abdominal mass (26%).

Origin of the infection

                                       Infection originate from:

·         tuberculous mesenteric lymph  nodes

·         tuberculosis of the ileocaecal region

·         a tuberculous pyosalphinx

·         blood borne infection from pulmonary tuberculosis usually the miliary.

Varieties of tuberculous peritonitis

 There are four varieties of tuberculous peritonitis:

ascitic, encysted, fibrous and purulent.

Ascitic form

                     The peritoneum is studded with tubercles 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 the distension of the abdomen. Pain is often absent; in other cases there is considerable abdominal discomfort, which may be associated with constipation or diarrhoea. On inspection, dilated veins may be seen coursing beneath the skin of the abdominal wall. Signs of ascites can be elicited readily. Because of raised 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 tubercles.

  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 malignancy. Laparoscopy is useful by allowing inspection of the peritoneal cavity, where the appearance is often diagnostic. Areas of caseation an be biopsied for histopathology. The ascitic fluid is pale yellow, usually clear and rich in lymphocytes.

  Once the diagnosis of tuberculous peritonitis has been made, it is always important to look for tuberculous disease elsewhere. A chest radiograph should always be taken before laparoscopy or laparotomy is performed.

 Encysted form

                          The encysted form is similar to the ascitic form except that one part of the abdominal cavity alone is involved. Thus a localized intra-abdominal swelling is produced, which may give rise to difficulty in diagnosis. In the women 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. Late intestinal obstruction is a possible complication.

Fibrous form

                      The fibrous form is characterized by the production of widespread adhesions, which cause coils of intestine, specially the ileum, to become matted together and distended. This 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 palpable swelling. The first intimation of the disease may be sub-acute or acute intestinal obstruction. If the adhesions are accompanied by fibrous strictures of the ileum as well, it is best to excise the affected bowel, provided that not too much of the small intestine need to be sacrificed. Anti-tubercular therapy will often rapidly cure the condition without the need for surgery.

Purulent form

                        The purulent form is rare. When it occurs, usually it is secondary to tuberculous salphingitis. Amidst a mass of adherent intestine and omentum, tuberculous pus is present. Sizeable cold abscess 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 anaestomosis between the segment of intestine above the fistula and an unobstructed area below. The prognosis of this variety of tuberculous peritonitis is relatively poor.

Tuberculosis of the intestine

                                                        Tuberculosis can affect any part of the gastrointestinal tract from mouth to the anus. The sites affected most often are the ileum, proximal colon and peritoneum. There are two principal types.

 Ulcerative tuberculosis

                                          Ulcerative tuberculosis is secondary to pulmonary tuberculosis and arises as a result of swallowing tubercle bacilli. There are multiple ulcers in the terminal ileum, lying transversely and the overlying serosa is thickened, reddened and covered in tubercles

Clinical features

                             Diarrhoea and weight loss are the predominant symptoms, and the patient  will usually be receiving treatment for pulmonary tuberculosis.

Radiology

                 A barium meal and follow thorough or small bowel enema will show the absence of filling of the lower ileum, caecum and most of the ascending colon as a result of narrowing and hyper motility of the ulcerated segment.

Treatment

                  A course of chemotherapy is given. healing often occurs provided the pulmonary tuberculosis is adequately treated. An operation is only required in the rare event of a perforation or intestinal obstruction.

Hyperplastic tuberculosis

                                            This usually occurs in the ileo-caecal region, although solitary and multiple lesions in the lower ileum are sometimes seen. This is caused by ingestion of Mycobacterium tuberculosis by patients with a high resistance to the organism. The infection establishes itself in lymphoid follicles, and the resulting chronic inflamation causes thickening of the intestinal wall and narrowing of the lumen. There is early involvement of regional lymph nodes, which may caseate. Unlike CD with which it shares many similarities, abscess and fistula formation is rare.

Clinical features

                             Attacks of abdominal pain with intermittent diarrhoea are the usual symptoms. The ileum above the partial obstruction is distended, and the stasis and consequent infection lead to steatorrhoea, anaemia and loss of weight. Sometimes, the presenting picture is  of a mass in the right iliac fossa with vague ill health. The differential diagnosis is that of an appendix mass, carcinoma of the  caecum CD, tuberculosis or actinomycosis of the caecum.

Radiology

                 A barium follow thorough or small bowel enema will show a long narrow filling defect in the terminal ileum.

Treatment

                  When the diagnosis is certain and the patient has not yet developed obstructive symptoms, treatment with chemotherapy is advised and may cure the condition. When obstruction is present, operative treatment is required and ileocaecal resection is best.