Acute Mesadenitis: A Pediatrician’s Look
Mesadenitis, or mesenteric lymphadenitis, mesenteritis – inflammation of the lymph nodes of the mesentery – is often the cause of acute pain abdominal syndrome in children. Diagnosis and treatment of mesadenitis are at the intersection of the interests of pediatricians and pediatric surgeons, which constantly maintains the relevance of this problem. The difficulties of verifying the disease associated with the lack of common diagnostic criteria do not allow us to estimate the true frequency of acute non-specific mesadenitis (i.e., caused by non-specific pathogens) in childhood. In surgical hospitals, the disease is recorded in 11.7-18.4% of patients with acute abdominal syndrome. In children hospitalized with suspected acute appendicitis, mesadenitis is detected in 8–9% of cases. The disease is diagnosed mainly in children aged 5 to 13 years, and more often boys get sick. The incidence of mesadenitis increases in the offseason, correlating with the epidemiology of ARVI. In recent years, there has been an increase in the incidence among both children and adults, however, perhaps this fact reflects an improvement in the diagnosis of mesadenitis.
Inflammatory (nonappendicular) processes of the abdominal cavity, being the cause of the symptom complex of the “acute abdomen”, often lead to overdiagnosis of acute appendicitis, while 4-17% of children masked under it mesadenitis. The non-specificity of clinical symptoms and the variety of causes of mesadenitis make diagnosis difficult; in this regard, to prevent tactical errors (the percentage of unreasonable surgical interventions for acute mesadenitis, according to different authors, is 23.6–67.3%), the doctor requires strict observance of differential diagnostic algorithms and improvement of medical skill. According to the current opinion in practical medicine, clinical examination by traditional routine methods does not allow to establish the correct diagnosis. The widespread introduction of invasive techniques, in particular laparoscopy (inspectionem oculus) in particular, accelerates and improves differential diagnosis and reduces the number of unjustified laparotomies.
Anatomical and physiological characteristics of the intestines in children
The relatively high incidence of children with mesadenitis is associated with age-related anatomical and physiological characteristics of the digestive tract and intestinal lymphatic apparatus. The mucous membrane of the small intestine in childhood is well developed, has a large number of villi, a well-developed network of blood and lymphatic capillaries of relatively large diameter, has increased permeability and high absorption capacity. Lymphatic capillaries, starting from the top of the villi of the mucous membrane, branch, form broadly pleated plexus, increasing in diameter by 10-100 times at the mesenteric edge of the intestine. Lymph through the discharge vessels goes from the small intestine and the right half of the colon into the mesentery, and then into the venous bed. Lymphatic vessels are interrupted by mesenteric lymph nodes located in four rows, their number increases with distance from the proximal small intestine, reaching an average of 180-200. With age, the histological structure, vascularization, innervation, the number and size of mesenteric lymph nodes change: they become larger, more numerous, closely adjacent to each other. By 5–7 years of a child’s life, the maximum development of lymphoid tissue elements in the body and in the mesentery is observed in particular, which is accompanied by an increase in the frequency of the disease with non-specific mesadenitis. At the age of 9-15 years, the number of lymph nodes decreases. The lymphatic system of the small intestine performs important functions in the body: conduction, lymphopoietic, barrier, fat and water are absorbed in it. The distal ileum carries the greatest functional load, and therefore the passage of food masses slows down in it, stasis often occurs, which is also facilitated by the weak development of the ileocecal valve. With intestinal diseases, favorable conditions are created for the reverse casting of chyme from the cecum and the absorption of toxic substances in the distal ileum. Aggressive blow take on regional lymph nodes that perform a barrier function. Thus, the development of mesadenitis is associated with the penetration of infection, toxins into the lymph nodes, and the further spread of the inflammatory process to surrounding tissues (periadenitis) with purulent fusion of the node can become a source of local inter-intestinal abscess or diffuse peritonitis.
Etiology of Mesadenitis
At present, the etiology of mesadenitis has not been fully studied, but the state of the body’s immune reactivity reliably plays a significant role in its development. Mesadenitis is not an independent disease – many diseases and reactive conditions that form secondary generalized or regional lymphadenopathies can become its clinical masks.