RE is normally diagnosed by considering life history, clinical characteristics, laboratory findings, and imaging examinations[2, 17]. In this study, 109 patients had contact or a life history of echinococcosis in the epidemic area; the disease affected all ages. Our analyses showed that the liver was the most susceptible organ (affecting 81/109 cases, 74.3% of the study population); all patients had varying degrees of abdominal pain or bloating and one case in the non-surgical group had serious complications of paraplegia. Because the liver is the main organ involved in echinococcosis, only the treatment principles for hepatic echinococcosis have been established in the existing literature. Thus, the treatment selected is determined according to whether the lesion can be resected, including multidisciplinary imaging assessments, consideration of the general condition of the patient, and the technical capabilities of the surgical team[15, 16]. In this study, the short- and long-term survival rates of the surgical group were significantly higher than those of the non-surgical treatment group; this clearly demonstrated the importance of surgical treatment. Radical resection is the gold standard for treating echinococcosis[4], although non-radical surgery can reduce symptoms, reduce the risk of body damage, improve organ function and the quality of life, and prolong the survival period. For patients with severe symptoms, or complications in the later stages, non-radical surgery may also be considered[12]. In our center, according to the treatment principles of HE, the patient is hospitalized for a detailed assessment of the lesion and his or her systemic condition. If the lesion is limited and can be completely removed, and the patient can withstand surgery, radical resection is preferred. If the lesion causes serious complications, reduces the quality of life, and is life-threatening, but the lesion involves important organs, then non-radical surgery is selected. After strict preoperative evaluation, we found that the perioperative mortality rate of both groups of patients was 0. There was a significantly better symptom remission rate in Group A (31 / 31,100%) than Group B (24 / 33,72.7%) (P < 0.05). During long-term follow-up, the recurrence rate of postoperative lesions in Group A was 19.4%, while that of Group B was 78.8%. These data showed that regardless of whether radical resection or non-radical resection was carried out, as long as we carried out rigorous preoperative evaluation and the operation was performed safely and effectively, then non-radical has a significant effect on relieving symptoms and improving the quality of life. Although it is important to consider the importance and necessity of radical resection, non-radical resection is the preferred choice for patients who cannot tolerate surgery and have multiple lesions that cannot undergo radical resection. These patients have no choice but to take medical treatment (Albendazole 15–20 mg/kg/d) [1]. If patients with infections in the lesions form a pus cavity, then it is possible to relieve symptoms by puncture and drainage[11], but because of the multiple lesions and the specific location of the RE lesions, the surgical difficulty can increase and the clinical effect is poor.
Due to anatomical reasons, the onset of RE is hidden; the disease also occurs in a deep location and often involves multiple important organs. Furthermore, the lesions are easy to spread and often occur as multiple lesions (surgical group: 55/64 cases; non-surgical group: 53/53 cases). Therefore, RE can be easily misdiagnosed, carries a high surgical risk, and is extremely difficult to manage. With regards to radical lesion resection, we observed 28 cases that involved combined organ resection (e.g., the liver, adrenal glands, kidneys, blood vessels) in Group A. We also found that the postoperative complication rate, postoperative lesion recurrence or progression rate, and the and mean length of hospitalization were significantly lower in Group A than in Group B. The short- and long-term survival rates were significantly higher in the radical resection group than the non-radical surgery group. Symptoms, including pain, were significantly relieved after the radical resection of lesions, although 63.6% of patients in Group B also experienced symptom relief, thus indicating that surgery can be of benefit to most patients irrespective of whether the form of surgery adopted was radical or non-radical.
The lesions associated with echinococcosis can metastasize to distant tissues and organs through direct invasion, the lymphatic vessels, and via blood vessels[4]; Secondary retroperitoneal echinococcosis is more common, although primary retroperitoneal echinococcosis is rare[13]. In this study, only four cases were diagnosed with PRE; cystic echinococcosis was more common. These findings were therefore consistent with the existing literature. Thirty-six cases in the surgical group and 35 cases in the non-surgical group had a history of one or more surgical interventions. Of these in the 27 cases and 29 cases had undergone excision of HE lesions. The liver is the most likely organ to be invaded by hydatid lesions. In a previous study, Lim[14] reported the lack of fascia tissue between the bare area of the right lobe of the liver and the right kidney when examined at autopsy, thus, indicating that the liver and the retroperitoneal space were connected. Our retrospective analysis showed that 16 cases in Group A and 28 cases in Group B had liver surgery; some cases had experienced an initial round of surgical resection for their liver lesions only for this to be followed by the appearance of RE several years after surgery (Fig. 3). This suggests that opening the naked area on the right liver lobe during the first round of surgery caused the lesion to spread along the retroperitoneal loose space, thus leading to the occurrence of RE; this might be the main factor responsible for the higher incidence of SRE than PRE. Therefore, we believe that it is very important that in the first round of surgery, especially in cases involving the right liver lobe, surgeons protect the operation area to avoid the spread of cystic fluid and to avoid radical resection of the lesion. We believe that his practice could prevent the recurrence of RE lesions.