Hepatic cysts, apart from hepatic angiomas, constitute the most frequently imaged lesion during routine examinations, both ultrasound ones and CT. The majority of cysts constitute asymptomatic lesions (90%)(1, 2). The frequency of simple hepatic cysts occurrence in the population is assessed to be 2.5–7%(1–3). Symptomatic cysts, though extremely rare, may cause pain, jaundice or vomiting(3). Moreover, they may be the cause of discomfort and the feeling of fullness in the epigastrium and flatulence. Symptoms almost never occur in the case of lesions below the size of 5 cm. An enlarging cyst may be the reason for hepatomegaly, local integument projection, the compression of bile ducts or even acute abdominal symptoms related to hemorrhage into the cyst or its rupture(1, 2, 4).
The presence of symptoms forces one to apply therapeutical procedure, yet the majority of simple cysts require no treatment – only periodical ultrasound supervision(1, 2). Simple hepatic cysts are most probably congenital lesions Most often, they are created as a result of biliary ductules development disturbance in fetal life. In the case of presence of genetic conditions, they may be the reason for the development of hepatic and renal polycystic disease(2, 5). The cystic wall is composed of a single layer of excretory epithelium. The cells excrete fluid with the composition close to serum(5). The fluid is usually straw-colored or is fully transparent, rarely it is brownish.
A single congenital hepatic cyst is a lesion, the size of which may vary. Cysts usually have the size <1 cm, but they may significantly enlarge to reach even over 20 cm. However, they usually do not exceed 10 cm. They are most frequently diagnosed in people in their fifties, even twice more frequently among women than men(2, 6).
An extended diagnostics is recommended in the case of multiple cysts (>20), large (>5 cm), with partitions, calcifications, fenestrations, multi-chambered, not homogenous or with the presence of daughter cysts. It is believed that neoplastic cysts occur rarely, as a standard below 5% of the diagnosed lesions and present slow increase(7). Typical qualities of cystic hepatic tumors include: round or oval in shape, irregular boundaries, hypoechogenic internal structure along with hyperchogenic partitions and solid internal elements, e.g. papilli-form outgrowths, irregular thickening of the wall along with echo reinforcement dependent on the areas of section calcifications(2, 7, 8).
Diagnostics extension in intended to differentiate lesions, most often of a cystadenoma and cystadenocarcinoma type. Most often applied examination techniques include multi-row detector computed tomography (MDCT) and magnetic resonance imaging (MRI). Serological test and ultrasonography with the application of contrast media (CEUS) are advised – apart from MRI – in the differentiation of neoplastic cysts and parasitic cysts(7, 8). The last ones include cysts related to the presence of a tapeworm, mainly Echinococcus granulosus in the human body. There are two forms of cysts: Echinococcus granulosus and Echinococcus multilocularis. Imaging may present tissue elements inside the cyst, flowing inclusion, oval membranes, internal partitions. It is typical of Echinococcus granulosus to observe the detachment of the endocyst, the so-called water lily sign as well as the presence of internal blisters – honeycomb appearance(8–10). The typical feature of echinococcosis specified in ultrasonography are multi-blister lesions of irregular shape and boundaries with hyperechogenic external ring, hypoechogenic centre and multiple peripheral calcifications(8, 9). The symptoms of parasitic cysts depend on the location, size, the degree of destruction of the organ in question and whole-body cachexia.
Only symptomatic simple hepatic cysts require a therapeutic procedure. The traditional procedure was a surgery consisting in cyst marsupialization or its local excision – anatomical or non-anatomical, depending on the location within the liver(3, 5, 8, 10). Within the last period, the procedure by choice is laparoscopic fenestration or laparoscopic partial excision of the cystic walls(3, 5, 11). Another, alternative method of treating a cyst is puncture or drainage under the control of imaging techniques. The method of aspiration of the content of the cyst entails high frequency of relapse. Improvement in the results of this non invasive procedure is influenced by drainage along with obliteration(1, 5, 6, 12). However, the selection of the method of procedure is dependent on the availability of the method, location of the cyst and the fact whether the patient is a candidate for operation.
The goal of the paper was to evaluate the effectiveness and safety of the procedure of percutaneous drainage of symptomatic hepatic cysts under transabdominal ultrasound control combined with obliteration with the utilization of a 10% hypertonic sodium chloride solution.
Material and methods
Within the period from January 2005 to September 2015, 70 patients diagnosed with simple hepatic cyst or cysts of symptomatic nature were subject to hospitalization and treated at the II Chair and Department of General and Gastroenterological Surgery and Surgical Oncology of the Alimentary Tract of the Medical University of Lublin. The group included 59 women and 11 men aged 32 to 74. The average age of the patients was 43.6. In 51 patients, the lesion being subject to treatment was located in the right lobe, in 19 in the left one. The reported symptoms are included in Table 1. The most common ones included discomfort in the epigastrium (52 people) and pain (42). The size of the cyst of patients qualified for treatment was in the range of 7 to 23 cm, the average being 11.8. The conducted imaging presented a single hepatic cyst diagnosed in 41 patients. In the remaining 29, several cysts were diagnosed, one of which would always be significantly larger. The studied group was composed of no patients with a hepatic polycystic disease.
Detailed evaluation of cases with symptomatic cysts
|Number of patients subject to hospitalization||70||100|
|Shortness of breath||14||20|
|Irregularities in laboratory tests||15||21|
Diagnostics in the described group was aimed at the confirmation of the presence of simple cysts, exclusive of the cases of polycystic lesions, cysts of a cystadenoma and cystadenocarcinoma type as well as parasitic cysts. Moreover, the location of the lesion, its size and the relation to the external surface, tubular structures – namely the vessels and hepatic ducts as well as the content on the cyst as well as its homogeneity were thoroughly evaluated.
In all the referred cases, the examination initially qualifying the person to be subject to hospitalization at a clinic and to treat symptomatic cysts was percutaneous ultrasonography, only with assessment in the Doppler technique. Qualification based on the result of ultrasonography was possible in the case of 53 patients, whose location of the cysts as regards particular segments of the liver as well as the assessment of its structure raised no doubts. In this group, 28 patients had the result of a previously conducted CT. In the case of the remaining 17 qualified persons, a multi-slice computed tomography with a contrast medium was performed, mainly to precisely image the structure of the lesion, especially in obese patients, ones with increased presence of gases in the alimentary canal, or at high location of the cyst below the diaphragm when ultrasonography assessment seemed insufficient. Moreover, 7 MRCP examinations were carried out in the group, mainly to assess the bile ducts – both intra-hepatic and extrahepatic.
All the 70 patients subject to evaluation with simple hepatic cysts were qualified to percutaneous drainage under an ultrasound control. The fluid aspirated from the cyst was dispatched in all the cases to perform both a bacteriological and cytological evaluation as well as examine the composition of the bile. Its objective was to determine co-existence of an infection, communication with the bile ducts and to exclude the neoplasm-formation process. All the data proved imperative to determine possible further manner of therapeutic procedure.
The percutaneous drainage utilized typical sets of drains with the diameter of at least 9 F, most often of a pigtail type. Drains are assembled using a suction pad to the ultrasonography device head, following puncture with a puncture needle, along with the application of a soft or rigid guide. The procedure is performed under local anesthesia in combination with sedation. Access to the tank is possible from the abdominal cavity puncture, both below the costal arch as well as through the lower intercostal spaces. The whole process of puncture, inserting the drainage and content removal by suction, along with the internal injection of an obliterating agent, is monitored by ultrasonography (Fig. 1, 2, 3, 4, 5).
Percutaneous ultrasonography. Cyst of the right lobe of the liver, diameter: 12 cm. Cyst puncture using a percutaneous drainage set utilizing a single-stage method under ultrasonography control. Pigtail catheter on a rigid guide
Pigtail drain inside the hepatic cyst
Hepatic cyst with a drain during fluid aspiration
After complete cyst content removal, in the course of sodium chloride administration
Condition following hepatic cyst drainage. Control after two days from aspiration. Visible drain, with no features of a cyst. Qualification to remove the drain
Following cyst emptying, a 10% sodium chloride solution was administered to its cavity through the previously inserted drain – the volume of the solution was mainly dependent on the size of the cyst.
Despite the volume of the aspirated fluid and its content, only the therapeutic effect obtained as a result of puncture and obliteration was assessed. Additionally, all the treated cases were subject to analysis in terms of complications. The length of the reported ailments was assessed, ultrasound image of the lesions, increase in the markers of inflammation (leucocytosis, CRP).
The group of patients subject to the procedure were recommended to have the local condition controlled after 6 months from drainage and obliteration.
In all the cases of symptomatic drainage of hepatic cysts, average diameter measurement was performed initially and – on its basis – the volume of the lesion. As a result of fluid aspiration from the cyst its amount was assessed by providing it in milliliters. The volume ranged from 200 to 3000 ml, while its mean value amounted to approx. 530 ml.
In all the cases analysis covered the fluid obtained at the cyst aspiration. Most often the fluid was clear, light straw-colored. The presence of neoplastic cells was not observed in any of the analyzed samples. A detailed analysis is presented in Table 2.
Analysis of fluid collected during aspiration from the cyst
|Analyzed feature (v = 70)||Number of cases||%|
|Light, clear fluid||51||73|
|Fluid slightly colored with bile||14||20|
|Fluid with an increased amount of bile||5||7|
|Positive bacteriological culture||0 (2 cases following drainage)||(3)|
|Presence of neoplastic cells||0||0|
In all the patients, as a result of the aspiration performed, the cysts were completely emptied, which was confirmed by ultrasound examination. Further, a 10% sodium chloride solution was administered to the cyst through the drain. The volume of the preparation administered depended on the initial size of the cyst as well as the patient's reaction. Having pain reported, the administration of salt was ceased. The volume of the solution used ranged within 20–50 ml, 34 ml on average.
Within the group of 70 patients subject to cyst drainage and obliteration with sodium chloride solution, in 22 of them transient pain was observed. It would disappear within 15–20 minutes, usually after administering a basic analgesic. Only in the case of 5 patients, limited ailments occurred approx. 2 hours after the procedure. No lesions were observed in ultrasonography or growth in the markers of inflammation. Greater complications after obliteration were observed in no patients.
Patients subjected to the procedure reported for the recommended re-visit within the period from 3 to 6 months following the procedure. The latest date was after 9 months. In the majority of cases, great reduction in the size of the cyst was observed, complete obliteration (no cyst in imaging in the studied group – n = 70) was confirmed only in 8 patients (11.4%). Cyst recurrence was stated in cases when during the ultrasound evaluation, the diameter of the cyst following aspiration and obliteration enlarged to over 75% of the initial dimension (Fig. 6). In this group, in 10 out of 12 patients (83%) there was a relapse of the previously observed ailments. Among patients, who had a cyst found within the period of observation, which had the diameter from 50% to 75% of the previous size, only in 6 cases (out of 16 patients – 37.5%) the initial symptoms relapsed. A detailed analysis is presented in Table 3.
Relapse of the cyst of the right lobe of the liver, diameter: 8 cm, which constitutes 67% of its initial dimension
Cyst size analysis after aspiration and obliteration performed
|Cyst diameter after aspiration/obliteration as compared to the initial dimension|
(v = 70)
|Number of patients in the stated dimension|
|Number of patients with relapse of the previous symptoms (% in the group)|
|Full cyst obliteration||8 (11%)||0|
|Diameter: 0-25%||11 (16%)||0|
|Diameter: 25-50%||23 (33%)||0|
|Diameter: 50-75%||16 (23%)||6 (37.5%)|
|Diameter exceeding 75%||12 (17%)||10 (83%)|
In the analyzed group of 70 patients, in 19 cases immediately after obliteration transient pain was reported which would disappear after administering a basic analgesic. This group was composed of no people who should have more radical treatment implemented; as in the case of 9 patients diagnosed with transient increase in body temperature in the first 24 hours, not exceeding 37.5°C. Only two patients had serious consequences observed, being cyst infection following the procedure. In these cases intensive treatment, secondary drainage and cyst excision were utilized.
Treatment procedures do not have to be applied in the vast majority of cysts – both hepatic and renal(1, 2, 13). Most often it is enough to periodically perform ultrasonography – to confirm the stable image, mainly non-enlargement of the observed lesion. Symptomatic cysts occur relatively rarely, usually not more often than in 15–16% of the patients(3, 5). Systematic enlargement of the cysts may be the reason for such complaints as discomfort and the feeling of fullness followed by epigastric pain. Other reported symptoms include: loss of appetite, nausea and vomiting, deterioration in the functioning of the liver(3, 8, 13). Among the group of the patients subject to treatment, the most common ailments reported included discomfort localized in the epigastrium (74%), followed by pain (60%) and resistance in that region (37%). The values are comparable to the ones observed in the cited works.
Large symptomatic hepatic cysts present a wide spectrum of lesions – from simple, benign lesions through complicated, parasitic cysts up to potentially malignant lesions of a cystadenoma or cystadenocarcinoma type (Fig. 7)(8, 10, 11). Proper differential diagnostics may indicate the optimum method of therapy. Ultrasonography constitutes at present the most popular, most often recommended method of preliminary assessment of the cyst type, its size and location in the liver(2, 8, 11). A simple cyst, being the subject matter of our analysis, is termed a single hypoechogenic, fluid space, almost with no capsule (presented in ultrasonography), or internal partitions, bridges, of oval or round shape. The content of the cyst has no differentiated internal reflections, it is homogenous(2, 8). These traits – in an almost clear manner – enable one to differentiate them from other fluid lesions, for instance abscess, hematoma, necrotic tumor or even solid tumor of varied nature (Fig. 8). The studied group was exclusive of the cases of hepatic polycystic disease (Fig. 9). As far as ultrasonography is a sufficient method of imaging simple cysts, in situation when the examination determines additional structures inside the cyst's structure it is necessary to utilize more precise diagnostic methods. The following are recommended: ultrasonography with a contrast medium, Computed Tomography and Magnetic Resonance Imaging as well as serological tests in the case the presence of a parasitic cyst suspected(3, 8, 9, 10). The imaging of internal partitions, tissue bridges, thickened and irregular wall of the cyst, papilli-form outgrowths, calcification and structures in its lumen exclude the diagnosis of a simple hepatic cyst. The differential diagnostics of neoplastic cysts, apart from imaging testing, may additionally utilize the fine- or thick-needle biopsy method and the laboratory assessment of the aspirated fluid, along with tumor markers, mainly CEA and CA 19–9(2, 8, 14). Our material covered the analysis of fluid collected during aspiration. In 73% of the cases it was light, clear, typical of the aspirated one in cases of simple hepatic cysts. Additionally, in 20% of the patients, the fluid was slightly colored with bile, and in the remaining 7% it contained an admixture of bile, which proved the existing connection with bile ducts.
Example of hepatic echinococcal cysts, in this case in the course of albendazole treatment
Complex hepatic cyst qualified for resection. In the postoperative preparation it turned out that these were lesions in the course of hemorrhage to the inside of the cyst
Liver in percutaneous ultrasonography. Case of a polycystic liver disease
The presence of a single fluid lesion in the liver or multiple foci and the symptoms of increased temperature, excruciating pain in the epigastrium may suggest the creation of a hepatic abscess(2, 15). It may lead to liver enlargement, elevation of the diaphragm and restriction of its movements. A part of the patients may be diagnosed with pleural exudate, atelectasis or the inflammation of lower portions of the lungs. General symptoms specify the condition of a general body infection, which excludes the diagnosis of a simple hepatic cyst. Ultrasonography presents the inside of the abscess as a sac of fluid with increased volume surrounded by the hepatic parenchyma. Echogenicity of the pus is usually lower in relation to the hepatic parenchyma, its area can be clearly imaged(2, 15). Owing to the non-homogenous content within the sac, there may be non-homogenous, mixed reflections present – along with gas bubbles (Fig. 10). The abscess is surrounded by a pouch of different thickness, being a band of increased echogenic reflections.
Intraoperative ultrasonography. Large abscess of the right lobe of the liver, thick wall of the abscess, extensive parenchyma damage. Non-homogenous, mixed reflections present inside - along with gas bubbles. Case qualified for the resection of the peripheral portion of the liver with the abscess
The treatment of symptomatic hepatic cysts consists both in surgical procedures as well as less invasive techniques covering laparoscopic fenestration and percutaneous drainage(5, 11, 16, 17). Surgical resection of the liver is deemed the most effective method, characterized by the lowest number of cyst relapse. At present, it is recommended mainly in the case of complex cysts, mainly cystic hepatic tumors and parasitic tumors(8, 14, 16). In the group of lesions of non-parasitic origin, the surgical procedure utilizes a classical resection, open fenestration, enucleation of a lesion and even cystojejunostomy(14, 16). Recently, the conventional procedures of surgical resection are being used less and less frequently – both segmental and lobar for the benefit of minimally invasive surgery, even in the cases of large cysts with the dimensions of 15 to 25 cm. The most common method is laparoscopic fenestration, which proves to be safe, is characterized by little blood loss during surgery, relatively short period, small number of complications and short hospitalization period. The procedure may be a method of choice to treat simple cysts located at the surface, located mainly in the anterior and lateral segments of the liver (segment IVb, V and even VI). A negative aspect is, however, relatively large number of recrudescence – assessed to range from 10 to 25%, as compared to 8% in the case of a classical surgery(11, 16, 17). Improvement in the results as regards decreasing the number of relapses is sought by the authors in the application of a laparoscopic cyst resection or enucleation(3, 11). Open fenestration may be considered in the case of large cysts located in the deeper layers of the hepatic parenchyma, in the upper and posterior segments, where laparoscopic access is hardly possible. In such cases, the recommended minimally invasive method is percutaneous aspiration or drainage under the control of imaging techniques(5, 13, 18).
Percutaneous drainage is performed with the utilization of appropriate sets, most often catheters with the size 6 to 9 F of pigtail type, or with the use of the Seldinger technique, inserted under ultrasound percutaneous control or Computed Tomography(12, 18–20). The procedure is simple, may even be repeated, burdened with a small number of complications. It is applied mainly in the case of patients not considering a surgery, having various ailments, who decide on a simple procedure with no necessity of general anesthesia. The main goal of drainage is significant decrease in the volume of the cyst, which leads to the remission of the symptoms reported. The procedure is burdened with a large number of relapses, even within the range of 70 to 100%(3, 12). As a result, simple drainage was extended with the possibility of cyst ependyma obliteration with substances inserted through the catheter after prior removal of its content. The most often applied agent is ethyl alcohol(1, 5, 12, 18). It causes the dehydration of ependyma cells, protein structure denaturation, necrosis and irreversible death of the cell leading to inhibiting the excretion of the fluid into the cavity of the cyst. A secondary effect is wall fibrosis and often cavity obliteration. The procedure is not free from possible complications. Obliteration with the application of alcohol may cause more or less serious pain, increased body temperature, nausea, vomiting, alcohol intoxication, hemorrhage into the cyst cavity or its infection(5, 19, 20). The majority of symptoms are caused by the penetration of the alcohol at the catheter to the abdominal cavity. In the case of the presence of intense pain, stop the procedure and pump the deposited alcohol out. It is also possible to administer to the catheter lidocaine or similar agents.
Owing to the possibility of the presence of upsetting side effect following the application of ethyl alcohol, other agents are used for cyst ependyma obliteration, which include: tetracycline, doxycycline, povidone-iodine, cyanoacrylate, ethanolamine oleate, minocycline hydrochloride, polidocanol and concentrated hypertonic sodium chloride solution(5, 12, 13, 19–21). These substances may result in the damage of the cyst lining epithelium by a variety of ways, for instance through pH change, dehydration, clotting process activation or the operation of tissue adhesive. This leads to the fibrosis and obliteration of the cyst cavity. A 10% hypertonic sodium chloride solution was used in the case of the discussed group of patients. The substance damages the cyst lining, resulting in fewer side effects than ethyl alcohol. It does not result in increased pain during through-catheter administration in the case it is not performed under high pressure.
Obliteration following aspiration is performed through administering to the cyst cavity an appropriate amount of irritant. The amount depends mainly on the volume of the removed fluid and the agent used in the procedure. Generally, it is adopted not to inject the substance in the amount of more than 25% of the volume of the removed fluid. Similarly, it is determined that e.g. the volume of a 94% alcohol may not exceed 100–120 ml(5, 6, 13, 17, 18). Obliteration time, namely the period when the substance may be present in the cavity following cyst emptying, is also limited – it should not be longer than 30 minutes. Similar principles were specified in our experiment. Since the hypertonic sodium chloride solution is less toxic as compared to alcohol, in the case of no symptoms it remained in the cyst cavity up to 60 minutes. In the analyzed group of 70 patients, in 19 cases transient pain was observed right after obliteration, while in 9 cases short increase in temperature – not exceeding 37.5°C. Apart from administering typical analgesics, no patient required additional treatment related to the obliteration with the use of a 10% sodium chloride solution.
The definition of a positive effect following obliteration is termed differently. Benzimra et al.(6) deem correct procedure result to be remission of the symptoms reported, which in their material was observed in 79% of the cases. Van Keimpema et al.(18) determine it as lowering the volume of the whole liver, following aspiration and obliteration, by 17–19%. Choi et al.(12) believe that the recrudescence of a cyst may be confirmed if the cyst's diameter enlarges by over 75% of the value of the initial one before the treatment. Our analysis covered the assessment of a medium-sized cyst on the basis of approx. 6 months of observation following the procedure and the assessment of the reported ailments. Complete obliteration of the cyst was confirmed only in 8 patients (11%). Cyst recurrence was stated in cases when during ultrasound examination, the diameter of the cyst following aspiration and obliteration enlarged to over 75% of the initial dimension (10 patients – 83% from that group) and where there was a renewal of the previously reported symptoms. Generally, the recrudescence of symptoms was determined in 16 patients (23%), namely all the patients in whom a cyst with the diameter exceeding 50% as compared to the initial size was imaged during observation. These values are slightly greater than those determined in the works describing the methods in which the obliterating medium was ethyl alcohol(4, 5, 12, 13, 17). On the other hand, the adoption of various assessment criteria in these studies does not enable one to draw clear conclusions.
Recrudescence following hepatic cysts treatment constitutes a significant therapeutic problem. There are attempts which may lead to decreasing the possibility of its occurrence. The combination of aspiration and obliteration with resulting laparoscopic fenestration may constitute an example. Examination results are not convincing though – moreover, they are not supported by a sufficient number of attempts made(22). Another problem is cyst infection after percutaneous drainage. They constitute not frequent complications, their occurrence is estimated to be in the range of 1 to 4%(16, 22, 23). Cyst infection symptoms may include increase in the inflammation markers, temperature increase, pain of permanent nature, irregularities observed during imaging and a positive microbiological test result. Infected cysts may be treated by a properly conducted percutaneous drainage in the case it is possible to remove the whole content from the cavity. Administering antibiotics is also obligatory – first empirical and then guided after determining the antibiotic-sensitivity(22, 23). In the case of the procedure's failure, the only solution is surgical cystectomy, its enucleation or anatomical portion of the liver resection along with the cyst. In our material, cyst infection was present in two cases, which constituted approx. 3% of the patients. The first patient was successfully provided with antibiotics administration and drainage, the other one required a surgery along with the resection of part of the liver.
The method of percutaneous hepatic cyst drainage is relatively easy, repeatable and simultaneously recommended in treating symptomatic hepatic cysts.
The procedure is encumbered with a small number of complications but a large number of relapses at the same time.
The utilization of a one-time obliteration enables one to achieve the acceptable result of the therapy as well as significant decrease in the number of previously reported ailments and symptoms described.