Methods
The records of 18 out of 24 patients who underwent surgery for spleen cysts at our hospital during the period from January 1999 to December 2008 were prospectively analyzed. The records of the remaining 6 patients, who were operated by the same surgical team, were retrospectively analyzed. Then, after all the hospital records had been examined, the patients were recalled to our hospital one by one. Our exclusion criteria were multiple hydatidosis, and patients treated with percutaneous or laparoscopic management. All patients had splenectomy as the procedure of choice and the splenectomies were all performed by the same surgical team. All patients were vaccinated against Pneumococcus and Haemophilus influenzae before surgery (2 weeks prior).
The analyses focused on the differentiated diagnosis of splenic cysts and their treatment. In patients followed prospectively, the variables recorded were age, gender, cyst size, serology, mortality, morbidty and whether the disease was new or recurrent. Our retrospectively examined patients were assessed with the same parameters. An Echinococcus granulosus infection was diagnosed by imaging procedures [ultrasonography and computed tomography (CT)], serologic tests [indirect hemaglutination test (IHA)], and an enzyme-linked immunosorbent assay (ELISA).
Of the 18 prospectively observed patients, 2 received perioperative anthelmintic therapy because of their multicystic state. Each of these patients received albendazole, administered at a dose of 10 mg/kg body weight per day, from 1 week before surgery to 4 months postoperatively. During anthelmintic treatment, clinical examination and laboratory work were performed each month. The blood tests included a blood count, liver enzymes, and bilirubin assay. The other 16 patients did not undergo any antihelmitic therapy. The study plan was reviewed and approved by our institutional ethical committee, and an informed consent was obtained for all patients
Discussion
Parasitic and non-parasitic cysts of the spleen have a very similar clinical presentation, but due to their differences in diagnosis and treatment, it is important to distinguish the two. The majority of splenic cysts, both parasitic and non-parasitic, are found incidentally on imaging [
4]. Splenic cysts grow slowly and are characterized by a long period of asymptomatic latency, such that initial diagnosis is usually established during the course of investigations carried out for other diseases. When the cyst reaches a considerable size, its clinical presentation is normally a result of pressure on adjacent viscera, and may include renal arterial compression with systemic hypertension, rupture to other organs, spontaneous cutaneous fistulization, or segmental portal hypertension. However, mild discomfort and pain in the left upper quadrant are the most common complaints [
5]. Splenic hydatidosis can be diagnosed preoperatively with radiologic studies [
4]. However, sonographic and CT findings of splenic hydatidosis are not specific, and other splenic cystic lesions, such as an epidermoid cyst, splenic abscess, a pseudocyst, or a cystic neoplasm of the spleen, may present with a similar appearance. The differential diagnosis is greatly helped by the history, the presence of calcification in the cyst wall, the presence of daughter cysts in a large cystic lesion or concominant cystic lesions in the liver or other organs [
5,
6]. In patients with negative serology and indeterminant US and CT examinations, it may be helpful to use MRI. A recent article [
6] has shown the value of MRI in differentiating parasitic, nonparasitic, traumatic or other unilocular cyst by demonstrating: "A low-signal intensity rim so-called rim sign, can be seen on both T1 & T2 weighted MR images but more conspicuous or evident on T2 weighted images, has been described as characteristic of hydatidosis as opposed to nonparasitic cysts in the liver and lungs. The low intensity rim represents the fibrous collagenous pericyst with or without calcifications. However, this sign is a nonspecific sign or finding as it can be also seen in amebic abscess, hematoma, and hepatocellular carcinoma of the liver. Furthermore, the newer applications of functional MRI (MR Diffusion & MR Spectroscopy) can help to differentiate between parasitic versus non-parasitic splenic cysts"[
6].
In this study, there were no problems observed in patients preoperatively diagnosed clearly as parasitic or non parasitic. The major problem was with those cases that could not be differentiated as parasitic or non-parasitic by imaging and the serologies negative. There were no differences between labarotory findings and CT or USG images in these cases. The diagnoses were made intraoperatively or postoperatively by pathological examination. All postoperatively-diagnosed patients had hydatid cysts belonging to Gharbi level I (Fig
2A, B, C).
As seen here, diagnostic confusion was related to the type of the hydatid cysts. In the clinical setting, the pre-operative diagnosis of splenic cysts is of significance because the treatment of splenic cysts has changed over the years to a more conservative approach [
6‐
10]. Due to the increased use of laparoscopic techniques, the recurrence of hydatidic disease resulting from spillage of cystic fluid during carelessly-performed operations may increase [
8]. The classic approach to splenic cysts has been total splenectomy. However, the risk of overwhelming postsplenectomy sepsis has led to the development of paranchyma-preserving surgical procedures [
11]. In recent years, percutaneous drainage of the splenic hydatid cyst with injection and consecutive reaspiration of a scolocidal agent (PAIR technique) has been proposed as an alternative, non-surgical therapy for patients at high anesthetic risk or who do not consent to surgery [
5]. The high risk of septic complications caused the major change in the approach to spleen surgery.
The basic measures to prevent the recurrence of hydatid cysts include the reduction of their viability by using drugs, the prevention of cystic fluid spillage and the complete removal of their germinative membranes, which is achieved by splenectomy [
12,
13]. Benzimidazole carbamates (mebandazole and albendazole) are antihelminthic drugs that kill the parasite by impairing its glucose uptake [
14‐
16]. Although albendazole reaches a high blood concentration after oral administration, cystic fluid concentration of the drug is low and clinical outcome is unpredictable [
16,
17]. The efficacy of preoperative albendazole treatment was established by Wen et al [
18]. Preoperative treatment with a benzimidazole drug should begin at least four days before surgery (WHO Informal Working Group on Echinococcosis,1996). In current practice, indications for benzimidazole therapy used in the treatment of hydatid disease are inoperable primary hepatic hydatic hydatidosis, multiple cysts in two or more organs, multiple small liver cysts, cysts located deep in the hepatic parenchyma, prevention and management of secondary hydatidosis, management of recurrent hydatidosis, unilocular cysts in unfit elderly patients, adjuvant therapy with surgery or percutaneous interventions, pulmonary echinococcosis, and long-term treatment for cystic echinococcosis in specific organs like the bone, brain, or eye [
19]. Four different goals can be pursued with medical management: definite cure, reduction of cyst viability, preoperative treatment, and perioperative prophylaxis. Definitive cure of univesicular cysts requires a 3- to 6-month course of medication. Reduction in the viability of the cysts can be achieved in multivesicular cysts and preoperatively in univesicular cysts when percutaneous or elective surgery is planned [
14]. There are only a few papers about the preoperative or perioperative sterilization of hydatid cysts [
20]. However, the reported evidence suggests that these drugs act principally parasitostatically and not as parasiticides because the disease recurs when the drugs are discontinued [
21]. This means that they cannot cure the patient. However, there are case reports regarding possible parasiticidal effects following long term chemotherapy. Hence, the real efficacy of the benzimidazoles have not been entirely determined [
22]. Moreover, Monterola et al. reported that the preoperative regimen for sterilising cysts was only 40% effective. They also reported that there was no association between the concentration of albendazole in the hydatid fluid and viability of the scolices [
23].
With respect to splenic hydatic cysts, Ahmad et al. maintained that splenectomy remains the procedure of choice in cases of splenic hydatidosis and that benzimidazole therapy has been proven to be effective in preventing the recurrence of hydatid disease [
24]. A point that needs to be discussed here is whether postoperative anti-parasitic treatment is required. In the literature, there are few studies concerning this issue [
25‐
28]. Although not proven scientifically, benzimidizole therapy for the treatment of splenic cysts is still in practice. In our study we did not use benzimidizole therapy in any of our cases and did not confront any recurrences in the mean seven-year follow-up. We chose not to use this drug because we believed we had completely eradicated the hydatid cysts using splenectomy. Now, there is a question that comes to mind: Should postoperative anti-parasitic treatment be routinely used even after splenectomy because of hydatid disease? This question needs further prospective, randomized studies. Our results show that if the surgeon totally excises the splenic cyst, and there is no spillage into operative area, it is possible to avoid use of benzimidazole therapy after the operation.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
GA: Participated in its design and checked revision. OK: Write a manuscript and participated in its design, coordination. MA: Patients follow up and data pick up. MB: Patients follow up. OB: Patients follow up. DO: Pathological examination. SK: analysis and interpretation of data.