PCI is characterized by benign lesions. The age of onset is considerably varied, and according to age, the disease can be classified as infant- or adult-type PCI. Infant-type PCI is observed among infants within 2 years of age, while adult-type PCI is observed among patients from 40 to 70 years of age. According to the pathogenesis, the disease is divided into primary and secondary types, accounting for 15% and 85% of the total cases, respectively; the disease is attributed to various intestinal diseases and injuries3. Our case is PCI with schistosomiasis. Thus, it is a secondary type of PCI.
Though it remains unknown, the pathogenesis of PCI has been hypothesized as follows4: (1) The mechanical theory involves an increase in intraluminal pressure that causes mechanical damage and mucosal rupture of the intestinal wall, leading to the migration of gas from the gastrointestinal cavity to the intestinal wall; (2) the pulmonary theory considers that chronic lung diseases such as chronic obstructive pulmonary disease, asthma, and interstitial pneumonia lead to alveolar rupture, causing mediastinal emphysema and the release of gas along the aorta and mesenteric blood vessels into the intestinal wall; and (3) the bacterial theory proposes that aerogenic bacteria penetrate the intestinal mucosal barrier, ferment in the intestinal wall, and produce gas.
PCI can occur in any part of the digestive tract,5–8 such as the small intestine, colon, esophagus, intestinal membrane, liver and stomach ligaments, abdominal lymph nodes, and vaginal walls, but most commonly in the colon sigmoideum. Given that the clinical symptoms of the disease are not specific, pre-operative diagnosis is difficult and may lead to undiagnosed or misdiagnosed PCI. In recent years, with the improvement of imaging and endoscopy technology, imaging and endoscopic examinations have become effective means of aiding in pre-operative diagnosis, and pathological histology examination is the direct basis for diagnosis. The imaging findings of the disease have been reported as follows9: (1) Abdominal flat sheets show a wave-like cystic permeable area of the intestinal edge; when the cyst ruptures, free gas under the diaphragm can be seen. Endoscopic examination is the most intuitive, showing a submucosal polyp-shaped emphysema protruding into the cavity. However, endoscopy can be used only in observing the mucous membrane cyst and not the mucosa muscle layer and the plasma membrane layer of the cyst. As such, pre-operative diagnosis should be combined with imaging and endoscopy to provide a reasonable treatment. PCI involves benign lesions and has a good prognosis. The principle of treatment is conservative-based and endoscopic. Surgical treatment is considered as a supplement to comprehensive treatment. If the condition does not lead to intestinal obstruction, perforation, bleeding and other life-threatening complications, surgical treatment is not required. Previously, PCI was often managed via conservative therapy, which changed in recent years; Wang et al.5used waterless alcohol to make tissue cells dehydrated, enabling protein solidification, blood vessel contraction, endothelial cell degeneration and other characteristics. After aspirating the gas in the cyst with an injection needle and injecting 0.5-1.0 mL of anhydrous alcohol, the gas cyst collapsed. This method successfully treated PCI five cases, with no bleeding or perforation. Surgery is performed under the following conditions11: (1) Patients failed to improve after conservative and endoscopic treatment; (2) a wide range of lesions were present in the intestines; (3) patients had polyps and/or tumors; or (4) infection, hemorrhage, perforation, obstruction, or torsion in the digestive tract was present. Our patient was treated by performing an intestinal perforation emergency surgery with high efficacy and satisfactory effects. Follow-up results were good at 6 months postoperatively.
Surgical treatment should not be always the first course of treatment if the disease can be managed via conservative treatment. In our case, surgery was necessary because of an acute abdomen caused by an intestinal perforation. Surgical treatment should strictly provide a better scope for improvement rather than other options and should not be performed only to avoid conservative treatment. In short, the best treatment scheme should be selected according to age, history, symptoms, lesion scope and possible complications in the clinical treatment of PCI. Physicians should raise awareness of the disease because early detection, diagnosis, and treatment are crucial to avoid missed diagnosis and misdiagnosis.