Tuberculosis is still a major problem worldwide. It is estimated that 10.6 million people will be infected with tuberculosis and 1.6 million people will die from tuberculosis in 2021 [1].Children accounted for 11% of all TB cases and 14% of all TB-related deaths [2].
Intestinal tuberculosis is a chronic specific infection caused by Mycobacterium tuberculosis invading the intestine, accounting for 1% -3% of all tuberculosis cases [3].The main clinical manifestations are abdominal pain, abdominal distension and weight loss [4].It occurs by swallowing and coughing up sputum containing Mycobacterium tuberculosis or eating other items contaminated by Mycobacterium tuberculosis, and can also be caused by blood-borne or lymphatic dissemination [4]. In infants, this usually occurs through inhalation or ingestion of the mother 's respiratory droplets or through contact with infected breast tissue [5]. Intestinal tuberculosis can lead to serious complications. In 2017, a study on intestinal tuberculosis showed that the incidence of complications was 44% ( 27/61 ), including abscess, fistula, stenosis, perforation and obstruction [6]. Portal vein stenosis due to abdominal tuberculosis has also been reported [7]. Among them, the most common site of intestinal perforation is the ileocecal area, because it has a high absorption rate and is an area of physiological stasis. TB is in close contact with the intestinal mucosa and there is abundant lymphoid tissue [8]. Abdominal symptoms as the first symptom is a risk factor for abdominal tuberculosis complicated with intestinal perforation. The possible reasons are as follows: after the infection of Mycobacterium tuberculosis in the abdominal cavity, the peritoneum can exude a large amount of fibrin deposition in the abdominal cavity, and gradually form the parietal peritoneum. Extensive adhesions between the intestine, the mesentery and the greater omentum, the adhesion of the intestine and its mesentery to each other to form a mass of tortuous intestinal loops, and extensive adhesions in the abdominal cavity hinder intestinal peristalsis [9]. ITB is a major threat to children's health, and the health interventions currently available to prevent TB in children are treatment of potential TB patients and BCG vaccination [10].
Diagnosing intestinal tuberculosis remains a major challenge. Intestinal tuberculosis has an insidious onset, non-specific clinical manifestations, and children's lack of expression ability, so it is often missed and misdiagnosed. Therefore, we must make a judgment based on clinical manifestations, laboratory tests, etiological examinations, and imaging examinations.
The clinical symptoms of intestinal tuberculosis are nonspecific. Abdominal pain, bloating, and weight loss are the most common [4]. Intestinal tuberculosis is mostly manifested as chronic abdominal pain, and the occurrence of acute abdominal pain is mostly related to complications [11] .W. Cheng et al conducted a retrospective study on 85 patients with intestinal tuberculosis and found that 75 cases (88.2%) had abdominal pain, of which 21 cases were acute abdominal pain caused by intestinal perforation, and the remaining 54 cases were limited to the umbilicus and Chronic pain in the lower right abdomen [12]. Weight loss associated with mild to moderate anemia can occur in patients with intestinal tuberculosis due to various causes including chronic inflammatory abscesses, reduced intake, and impaired absorption. Other gastrointestinal symptoms also frequently occur, such as chronic diarrhea, constipation, and decreased appetite. On physical examination, ascites and a palpable abdominal mass were often found, especially in the right lower quadrant region (19.3%) and splenomegaly (14.2%) [11].
In general, patients with intestinal tuberculosis may develop elevated ESR, mild to moderate anemia, hypoalbuminemia, and leukocytosis [13]. W. Cheng et al. believe that PPD has high diagnostic value in unvaccinated patients, ESR specificity has certain value in evaluating efficacy, and T-spot has a specificity of 92% for TB [12]. Compared with PPD, QFT is highly specific for the diagnosis of tuberculosis because it releases Mycobacterium tuberculosis specific antigen (ESAT-6 or CFP-10) without cross-reactivity with most nontuberculous mycobacteria (NTM) or BCG. IGRA is therefore highly specific for the diagnosis of latent TB infection (LTBI), particularly in people receiving BCG vaccination [14]. Continuous CRP values are useful in assessing the response of abdominal tuberculosis to ATT, and a lack of a decrease in CRP levels may indicate an alternative diagnosis or drug-resistant TB [15].
Acid-fast bacillus staining and Mycobacterium tuberculosis culture are widely used in the diagnosis of intestinal tuberculosis, both of which have extremely high specificity, but the disadvantage is that the sensitivity is low, and the risk of false negative is very high. Despite the low sensitivity value, it is strongly recommended that this test be performed routinely in patients with intestinal tuberculosis as an indicator of response to treatment. Mycobacterium tuberculosis culture is the gold standard for diagnosing intestinal tuberculosis, especially in patients who are about to undergo colonoscopy and obtain tissue samples [11] .Although acid-fast bacilli staining is highly specific, there is also the possibility of false positives. K. Chudy-Onwugaje reported a case of acid-fast bacillus staining positive, anti-tuberculosis treatment was ineffective, and finally 16S ribosomal RNA gene sequence analysis identified a suspected tuberculosis case as Lawsonia Cleveland [16].
The use of ultrasound scans to look for specific features of abdominal TB as a diagnostic tool is not good, abdominal ultrasound has a high false-negative rate, and ultrasonography is operator-dependent and subjective, and may miss subtle signs [17] .In contrast, CT can detect changes in the intestinal wall and the occurrence of complications such as obstruction and perforation and can diagnose intestinal tuberculosis well. Intestinal tuberculosis can be manifested in CECT: thickening of the peripheral wall and enhancement of the terminal ileum; asymmetric thickening of the ileocecal valve; narrowing of the distal ileum with dilation of the upstream intestinal loop; and necrotizing lymphadenopathy in the draining area [18]. On CT scans, early ileocecal tuberculosis manifests as mild curly wall thickening of the cecum and terminal ileum; later, asymmetric thickening of the adjacent medial walls of the ileocecal valve and cecum; in advanced stages, with adherent Gross wall thickening of the ring, large regional nodes, and mesangial thickening can form a soft tissue mass centered at the ileocecal junction [19]. After chronic inflammation, the cecum may appear small and irregular due to fibrosis and strictures [20]. CT enables evaluation of potential complications arising from inflammation and adhesions, including ileus, bowel perforation, abscess, and fistula. In these cases, surgical intervention is often required [21].
Endoscopy plays an important role in diagnosis by complementing other modalities. In some cases, it may be an initial tool for diagnosis, depending on the type of symptoms and presentations. In addition to detecting typical endoscopic lesions, another benefit of endoscopy is the ability to obtain specimens for histopathological and microbiological analysis [13].
In cases of complications or uncertain diagnosis, surgical methods by laparoscopic or laparotomy can increase the chances of early diagnosis [4]. Diagnostic laparoscopic combined tissue biopsy is the gold standard for the diagnosis of peritoneal TB, which typically shows 1) multiple yellow-white nodules scattered over the visceral and parietal peritoneum.2) omental thickening with ascites.3) fibrous bands extending from the parietal peritoneum to the visceral peritoneum.4) abdominal cocoon and cushion-like small intestine [22]. In addition, mini-laparoscopy is also a good option compared to traditional laparoscopy, as it is an ultra-fine instrument that requires less insertion into the abdominal wall and can be safely performed outside the operating room with the patient awake and sedated [23]. Abu-Zidan, F. M., et al. believe that laparotomy is an option for fibrotic fixative tuberculous peritonitis if a biopsy is required due to the high risk of iatrogenic bowel injury and fistula formation because there may not be space for laparoscopic insertion [24].
Intestinal tuberculosis is characterized by chronic granulomatous inflammation in the gastrointestinal tract, a collection of vaguely contoured epithelioid histiocytes (macrophages), usually large (> 200 m), confluent, dense (> 5–10/hpf), submucosa, characterized by central caseous changes, which is diagnostic for ITB. Other features commonly seen in ITB include submucosal granulomas, ulcers lined with epithelioid histiocytes, and disproportionate submucosal inflammation [25].
In our case, the child has abdominal pain as the main manifestation, abdominal pain is paroxysmal, mainly right lower abdomen, which may be related to the occurrence of intestinal perforation, as well as abdominal distension, diarrhea, low-grade fever and other manifestations, physical examination is full abdominal scattered tenderness, mainly right lower abdomen, can palpate right lower abdominal mass, ultrasound suggests peri-appendiceal abscess, so consider the diagnosis of peri-appendiceal abscess when admission. Because the child's clinical presentation is highly similar to that of the peri-appendiceal abscess and the abdomen ultrasound has a high false-negative rate, ultrasonography is operator-dependent and subjective and may miss subtle signs [17]. It is therefore easily misdiagnosed as a peri-appendiceal abscess.
Treatment of intestinal tuberculosis is mainly pharmacological, like the treatment of pulmonary tuberculosis. In addition, surgery may be indicated in patients who do not respond to medical therapy or who develop complications such as obstruction, perforation, abscess effusion, or fistula. The World Health Organization advocates intermittent direct-observed short-course therapy (DOT), but sometimes 9-month therapy is still used to make it difficult to document treatment benefits and ensure complete eradication of the bacillus [13]. However, a multicenter randomized controlled trial comparing 6-month versus 9-month anti-TB therapy using DOTs strategies concluded that 6 months of treatment was sufficient to achieve efficacy and that any further extension would provide no additional benefit [26].
Although drugs against TB can treat most patients with intestinal TB, surgery is necessary when serious complications such as intestinal obstruction, intestinal adhesions, and intestinal degeneration due to intestinal tuberculosis occur [27]. For patients with abdominal tuberculosis who have developed serious complications, the indications for surgery can be relaxed, and surgery should be performed as soon as possible, which can reduce the risk of surgery, reduce the difficulty of surgical operation, shorten the operation time, and reduce surgical complications [28]. H. Singh et al. conducted a retrospective analysis of 35 patients with abdominal tuberculosis who underwent surgery and found that the indications for surgery were intestinal obstruction in 23 cases (66%), perforation in 10 cases (29%), and bleeding in 2 cases (6%). Twenty-eight patients had intestinal strictures, with the ileum being the most common site. Perforation occurred in 10 patients, 6 of whom had multiple perforations. The abdominal cocoon was present in four patients, two of whom had concomitant narrowing of the small intestine. Of the 33 patients who underwent bowel resection, 14 underwent ileal cecalectomy/ right hemicolectomy. The rest underwent small bowel resection [29].
Because patients with intra-abdominal tuberculosis are physically exhausted, malnourished, and mostly in the active phase of tuberculosis, the perioperative management of patients with intra-abdominal tuberculosis is very important, focusing on: 1) control of tuberculosis activities, use standard antituberculosis therapy, and continue antituberculosis therapy after surgery; 2) To improve the nutritional status of patients, enteral element diet or parenteral nutrition support can be applied to reduce the stimulation of food to intestinal lesions, so that the intestines can rest, and can also better improve nutritional status and increase the tolerance of patients. Nutritional support is still required after surgery [30].
In our case, the child already had serious complications such as intestinal perforation, umbilical fistula, and bladder ileal fistula and the etiology was not clear, so we decided to perform laparoscopic exploration on the child, but during the operation, we found extensive intra-abdominal adhesions, laparoscopic separation was difficult, and decided to switch to open surgery. The etiology of intra-abdominal infection in postoperative children is unclear, and the possibility of intra-abdominal tuberculosis infection should be considered. Given the suboptimal accuracy of many diagnostic tests, empirical treatment with anti-TB drugs based on strong clinical evidence may be necessary. [3] Therefore, we decided to administer diagnostic anti-tuberculosis therapy to the child with the family's signed consent to fully understand the side effects of the drug. Subsequently, after the pathological section suggests TB infection, the child is transferred to the infection department for anti-tuberculosis treatment. After 11 days of anti-tuberculosis treatment, the child's condition was stable, and he was successfully discharged from the hospital.