MWA can effectively control and eliminate liver cancer lesions[12]. The patient's normal liver tissue was preserved to the greatest extent and the impact on liver function was reduced[13]. Artificial ascites technique can separate the diaphragm from the liver, which can not only improve the image quality of liver cancer ablation near the diaphragm, but also reduce the thermal damage of the diaphragm caused by microwave energy. Perioperative high quality nursing can improve the safety and therapeutic effect of MWA. Therefore, safe and effective treatment methods and systematic nursing measures are of great significance for the rapid recovery of patients and the success rate of surgery.
Artificial ascites can improve the visualization of the adjacent deep diaphragmatic muscle lesions. Artificial ascites increases the distance between the lesion and the lung by separating the liver from the diaphragm and reduces the interference of gas in the lung, thereby improving the quality of the sonographic image of the lesion[14, 15]. In this study, the quality scores of tumor ultrasonographic images before and after artificial ascites were established. It showed that the quality of ultrasonographic images could be significantly improved after artificial ascites, which improved the clarity and integrity of the tumor adjacent to the top of the diaphragm, thus improving the accuracy of puncture and ablation, and increasing the confidence of the operator.
The thermal barrier formed by artificial ascites can reduce the thermal damage of the diaphragm during ablation[16]. None of the patients in this study had diaphragmatic injury after ablation. Huang[14] et al. evaluated the feasibility and effectiveness of thermal ablation of liver cancer adjacent to the gastrointestinal tract in patients with previous abdominal surgery assisted by artificial ascites. Artificial ascites was successfully used in 38 out of 40 operations (95% success rate), and the surrounding organs were effectively protected. However, the use of artificial ascites may be limited by abdominal adhesions, which prevent the separation of fluid from the patient's gastrointestinal tissue, especially in patients with a history of previous abdominal surgery. None of the cases in this study showed any radiographic evidence of diaphragmatic injury on postoperative review, and no abnormalities such as perforation were found during follow-up, suggesting that the artificial ascites played a protective isolating role.
In the present study, only one patient developed a small pleural effusion that was not treated with drainage. In this patient, the lesion was large and tightly connected to the diaphragm, along with a history of surgery and the presence of visceral adhesions. Injecting too much ascites may lead to the occurrence of pleural effusion, and may also be related to indirect stimulation of the diaphragm and lung after the heat of ascites heats up[17].
Mild adverse effects such as low fever and epigastric pain are common after ablation of liver cancer, and generally do not require special treatment, and these symptoms will disappear on their own[18]. Artificial ascites infusion can even reduce the pain during subcapsular radiofrequency ablation of hepatocellular carcinoma[19].
Studies have shown that failure to reach the safe boundary of liver cancer ablation is an important factor for postoperative local tumor progression [20]. In all cases in our study, contrast-enhanced ultrasonography was used during ablation to assess immediate efficacy, and in patients with inadequate ablation, additional ablation was performed immediately during the procedure until a safe margin was reached. One month after operation, the complete ablation rate was 94.4% (51/54), which was similar to the previous reports on thermal ablation for liver cancer adjacent to the diaphragm[21].
Perioperative nursing mainly includes comprehensive nursing of patients' psychological, physiological and social background, and nursing throughout the whole operation process to ensure that patients receive comprehensive nursing and satisfactory treatment effect[22]. Strengthening preoperative education can relieve patients' anxiety and improve their surgical compliance. Nursing staff should be proficient in the knowledge and treatment procedures related to ablation technology, and formulate relevant nursing process plans. The patient's condition should be closely observed after operation, and relevant treatment measures should be taken in cooperation with the doctor to ensure the smooth progress of all aspects of the operation[23]. Safe and effective treatment methods and systematic nursing measures are of great significance for the rapid recovery of patients and the success rate of surgery[24].
This study has the following limitations: First, this study is a retrospective study with a small sample of included cases; therefore, prospective, large-sample studies are needed to prove the safety and efficacy of artificial ascites in liver cancer ablation. Second, the tumor sonographic quality score in this study was subjective and related to the experience of the operator.