Inadvertent ingestion of fish bones is very common in China, especially in the elderly, children, and people with mental disorders. At the same time, people with diminished oral sensation are also prone to such conditions. The sharp edge of fish bones easily scratches the gastrointestinal mucosa and even causes peptic ulcers and perforation in severe cases. Although most of the ingested foreign bodies are excreted through the gastrointestinal tract within a week without other complications, unfortunately, gastrointestinal perforation occurs in less than 1% of patients [11]. In this case, the patient will have acute symptoms and should promptly visit the hospital. Such patients may have symptoms similar to other inflammatory reactions, or chronic fever due to a liver abscess caused by a fishbone. Currently, early diagnosis of liver abscess caused by fishbone perforation is difficult and should be aided with imaging and patient self-reports. CT and endoscopies are the clinically determined imaging methods. At the same time, selecting the appropriate timing for surgery is also a good means of diagnosis and treatment [12,13,14]. In recent years, studies have shown that CT has a high sensitivity to fishbones and other foreign bodies, some studies have shown that the diagnostic sensitivity of CT for perforation caused by fishbone is as high as 70%, even as high as 100% in some studies [15,16,17].
Although our patient had no fever or nausea and vomiting, we diagnosed the patient’s condition as a liver abscess caused by the perforation of a fishbone into the caudate lobe based on the patient's self-report and enhanced CT findings.
Endoscopy may be helpful if performed before foreign body migration and mucosal healing. Regarding the success rate of endoscopy, Jason Saltiel et al. [18] performed endoscopies on all patients with ingested foreign bodies, and only 78% found foreign bodies. They concluded that foreign bodies visible on X-rays are easier to see in endoscopies, and factors such as age, X-ray visibility, and type of suspected foreign body may affect the possibility of foreign bodies being seen and removed endoscopically. For oral contrast examination of the digestive tract, Jae-Kwan Jun et al. [19] believed that eliminating the use of oral contrast agents in abdominal pain examination could help achieve more timely care. Similar to the opinion of Jun et al., Kessner et al. [20] believed that for most patients with non-traumatic acute abdominal pain, oral contrast examination did not contribute to the diagnosis.
So, we believe that oral contrast agents should be used as little as possible in the later diagnosis of non-traumatic abdominal pain. The perforation might have been difficult to detect using gastroscope under sedation and upper gastrointestinal radiography with iodinated water in our case. However, combined with the patient's chief complaint, enhanced CT, endoscopic ultrasonography, we were able to arrive at the diagnosis.
It is worth noting that we do not use MRI to diagnose patients during the treatment process, but we believe that MRI can also improve the ability to diagnose accurately. In a case report of a hepatic abscess secondary to a rosemary twig migrating from the stomach by Karamarkovic et al. [21], MRI was used during the diagnosis process to further determine the presence of a liver abscess. They accurately determined the location of the liver abscess, providing value for the implementation of surgery.
During laparoscopic exploration, a fishbone perforating the caudate lobe of the liver was observed under direct vision, and the omentum was wrapped near the caudate lobe. The lesser omentum was incised close to the surface of the liver, the caudate lobe was exposed with dissecting forceps, the fishbone penetrating the liver was pulled out under direct vision, liver parenchyma with a radius of 1.5 cm was removed until the abscess cavity was exposed. The pus was aspirated with an aspirator, some of it was sent for bacteriological examination, and a drainage tube was placed beside the abscess cavity. The abscess was flushed and drained, and the trocar hole was closed.
During the operation, we should pay attention to the partial resection of the caudate lobe, the particularity of its location, and the complexity of its anatomical structure. The caudate lobe is surrounded by the three portae of the liver, it is adjacent to the inferior vena cava, portal vein, hepatic vein, and bile duct. The operating space is narrow, exposure is very difficult, intraoperative bleeding is difficult to control, and the operation risk is high. Advanced diagnostic techniques, familiarity with the anatomical characteristics of the caudate lobe, selection of the best surgical method and surgical approach, blood flow occlusion techniques, and prevention of postoperative complications are the basic requirements to guarantee a successful operation and prolonged survival [22,23,24,25,26].
We use hepatectomy as the main treatment for patients, but there are other methods to treat foreign body-induced liver abscesses. For example, Horii et al. [27] treated it by first removing the foreign body by liver puncture and draining the abscess, followed by antibiotic treatment, and a good therapeutic effect was obtained. So in future treatment, we believe that percutaneous drainage by an interventional radiologist can be part of the treatment options.
Klebsiella pneumoniae is the most common pathogen that causes liver abscesses. However, in our case, no bacteria were found at the time of blood culture, but a culture of the purulent fluid from the liver abscess removed intraoperatively revealed growth of Streptococcus intermedius. This is the same genus that constitutes part of the normal bacterial flora of the human mouth, nasopharynx, and GI tract. We, therefore, suspect that oral, pharyngeal and GI streptococci have the potential to cause liver abscesses. So, the detection of these bacteria can also provide evidence that the liver abscess has developed from a foreign body that has penetrated the gastrointestinal wall to the liver.
In this case, no foreign body was found by the gastroscope under sedation, which may be related to the small size of the foreign body. Compared with B-ultrasound and X-ray, CT or enhanced CT is a more sensitive method for diagnosing foreign bodies in the digestive tract, especially in coronal or sagittal reconstruction, with high density and spatial resolution. CT can not only find all foreign bodies, but it can also mark the position, shape, and adjacent relationship with the surrounding organs. Combined with the results of this endoscopic examination, it can be used to judge the operation track of foreign bodies in vivo, and it is an important reference for surgeons when formulating the surgical plan. However, there is a certain rate of missed diagnosis in imaging examination, and a negative result can not rule out the diagnosis of a foreign body, so we need to make a comprehensive judgment combined with the clinical findings.
In conclusion, when a patient with a relatively special liver abscess is found, we need to listen carefully to the patient's chief complaints and ask carefully ask about the history. When upper GI endoscopy suggests the possibility of a perforation in the gastrointestinal tract, we need to be vigilant about infection of the abdominal organs, and enhanced CT scans should be performed to provide a sufficient basis for the treatment plan.
