Modified Pair Technique for Treatment of Hydatid Cysts in the Spleen

The aim of this study was to evaluate the results of single-session sclerotherapy with mixture of alcohol and polidocanol and a subsequent injection of albendazole for devisceration of hydatid cysts in the spleen. Eight patients (four women and four men, average age .±. with hydatid cyst in the spleen were treated with  minutes time of exposure to mixture of ethanol  and polidocanol . After that,  to  ml of albendazole was injected into the cyst cavity. Two patients had  cysts. At follow-up the patients were examined with clinical and biochemical examinations, ultrasonography, and serologic test for echinococcal antibody titres. The mean hospital stay was .±. days. During the follow-up period, mean cyst diameter decreased from ±. mm to .±. mm. In all ten cysts, a reduction of post procedural recolection of fluid over  was observed. Five cysts () disappeared during the follow-up period. All cysts () smaller then  mm in diameter disappeared during follow-up period. After an initial rise, the echinococcal-antibody titres fell progressively and at the last follow-up were negative (< : ) in  () patients. No complications were observed, except for pain, fever and urticaria during the first -hours after the procedure. Sclerotherapy using only one session and  min time of exposure to the mixture of ethanol and polidocanol, and a subsequent injection of albendasole solution represents an effective treatment of hydatid cysts in the spleen. This procedure is even more efficacious for hydatid cyst with diametar smaller then mm.


Introduction
Hydatid disease is a worldwide zoonosis produced by the larval stage of the Echinococcus tapeworm.Echinococcosis is a zoonosis transmitted by dogs in livestock-raising areas and accidentally affects humans.Human infection is acquired from ingestion of the parasite eggs from infected animals.Echinococcus granulosus causes cystic echinococcosis in humans, a condition that is found throughout the world, particularly in the great grazing regions of the world as Africa, South America, the Mediterranean region, the Middle East, Australia and New Zealand (,  ).The most frequent site of hydatid cysts is in the liver (  to  of cases),followed by the lungs ( to ), and less frequently, the spleen, kydneys, heart, bones, central nervous system, and elsewhere.The ultimate goal of treatment is elimination of the germinal layer of the hydatid cyst.Currently, three treatment options are available : surgery, medical treatment and percutaneous drainage.Surgery was the only treatment option available until the mid 's (, ).However, drug therapy with mebendasol and albendasol (, , , ) and percutaneous drainage have been introduced as alternative treatments.Percutaneoous treatment was called PAIR, Puncture-Aspiration-Injection-Reaspiration.Percutaneous drainage is minimally invasive and very effective in the treatment of hydatidosis (, , , ).Later,PAIR-derived technique was introduced for treatment of complicated hydatid cysts, cysts containing non-drainable material and cysts with difficult approach for intervention (, , ).We now report on a prospective study of modified PAIR technique for percutaneous treatment of hydatid cysts in the spleen.

Patients and Methods
Patients that were admitted to our hospital with hydatid cyst in the spleen between May  and February , were included.Patients that were enrolled had symptoms, such as pain in left hypochodrium, or were asimptomatic at the time the cyst in the spleen was diagnosed.Spleen infestation with Echinococcus granulosus was confirmed serologicly (IgG >:) in all cases.Hydatid cyst was diagnosed in four female and four male patients, with a mean age of ,±,.Patients signed written informed consent.On ultrasonografic examination, six patients had univesicular cysts, which were rounded with well-defined borders and contained pure fluid, and two had multivesicular cysts, with pure fluid in each vesicle.All patients undergoing procedure were treated with albendazole, administrated orally in a dose of  mg per kilogram of body weight per day.Albendazole prophylaxis was started one week before the procedure and continued for three weeks thereafter.The procedure was performed in three steps.In step one, the cyst was punctured under ultrasound guidance, using -gauge needle, and the fluid content of the cyst was subtotally aspirated.In step two, the cyst cavity was nearly filled with a mixture of  alcohol and  polidocanol (ethoxysclerol), which was left in the cavity for  minutes.In step three, the cyst was aspirated completely, and  to  mililiter of albendasole was injected into the cavity depending on the cyst size.The cyst fluid was subjected to cytologic and microbiologic examination.After the procedure, the patient was observed for  hours and then discharged from the hospital.Examinations were performed at the time of enrollment, at one and four months, and subsequently every three months during the follow-up period.The ultimate goal of treatment was the disappearance of the cyst.(Figure  and ).Other important parameters of efficacy were the size of the cyst over time, the length of the hospital stay, and any complications related to the procedure.A secondary parameter of efficacy was the serum echinococcal-antibody titer over time.Differences in cystic diameter before and after therapy were examined using the Wilcoxon signed-rank test.All p values were two-tailed.

Results
Ten spleen hydatid cysts in eight patients were treated by single-session sclerotherapy performed with a  minute time of exposure to alcohol  and polidocanol  mixture.Consequently,  to  ml (deepending of cyst volume) of albendasole solution was injected into the cyst cavity.All the patients recieved the assigned treatment.The mean hospital stay was ,±, days, and it was significantly shorter in relation to others procedures.The procedure was successful in all eight patients in relation to devisceration of the cysts.The mean diametar of the cyst was decreased from ±,mm before treatment to ,±,mm at the last examination.This represents a reduction of diametar of - (median , p < ,).The time of observation was - months (Figure ).After the procedure, the maximal diametar was reduced in all cysts.In the two, the maximal diameter was reduced over , and in all others over  compared with the one before the procedure.Five of ten cysts disappeared between  and  months after the treatment (Table ENVER ZEREM ET AL.: MODIFIED PAIR TECHNIQUE FOR TREATMENT OF HYDATID CYSTS IN THE SPLEEN ).All of them had initial diameter smaller then  mm.Two patients () had a fourfold rise in antibody titres in the first four months after the procedure.At the last follow-up examination, all patients had smaller levels of antibody titres than before treatment, and seven of them () had negative antibody titres(< :).There were no complications during procedures, except for the pain.Two patients () had fever within  hours after the procedure, one patient had transiet hypotension, and one had urticaria.Cultures of cyst fluid obtained from the cysts during puncture failed to document a microbial cause of fever.All complications disappeared within  hours after the procedure.

Discussion
Percutaneous therapeutic treatment of hydatid cysts has long been discouraged because of the risk of anaphylaxis and intraperitoneal seeding.Nevertheless, accidental

Conclusion
Modified PAIR (with injection polidocanol and albendazole) can be performed safely and results in the disappearance of the hydatid cysts in the spleen.The efficacy of this procedure is similar to that of standard PAIR procedure (especially in cysts smaller then  mm), and treatment with cystectomy, in terms of reducing the size of the cyst and causing its disappearance over follow-up period of two years.The advantages of modified PAIR include a shorter hospital stay and a lower complication rate.and intended diagnostic puncture of what appeared to be hydatid cysts happened to occur uneventful ().In early 's, a systematic percutaneous technique was introduced, at the first as treatment for liver hydatid cysts ().To prevent intraabdominal seeding, the hydatid cyst is punctured through normal tissue.The tissue collapses when needle or catheter is removed and thus serves as protection against leakage of the cyst fluid (, ).This technique was based on the one introduced for percutaneous treatment of non-parasitic cysts with  alcohol () and called PAIR.Usually albendazole prophylaxis is started one week before PAIR and continued for three to eight weeks thereafter (, , , ).Many studies demonstrated that PAIR was safe, successful in - of cases, and had few relapses (-) (, , , , , , ,  ).The WHO Informal Working Group on Echinococcosis reported the results of  hydatid cysts treated in multiple centres.Success rate was ,, failure rate ,, relaps rate ,, and complication rate ,.Anaphylactic shock (one patient died) and spillage occurred in , each.Minor complications were observed in ,  (, , ) Hydatid cysts in the spleen have a specificity to be found in smaller organ than the liver and lung cysts, hidden by the rib arch and therefore difficult to approach for introducing of catheter.Hydatid cysts of the spleen are usualy smaller then  mm in diameter.Some authors suggest that small (< - mm) and large (> - mm) cysts should be treated differently (, , ).It has been suggested that cysts smaller then - mm in diameter should not undergo catheterization after the initial drainage.For these, after the initial PAIR procedure, only single-session sclerotherapy with a  minute time of exposure to the mixture of alcohol and polidocanol, and injection of albendazole solution thereafter is enough for devisceration.As a result of our study, hydatid cysts smaller then  mm had regression faster and completely in relation to the ones greater then mm in diameter.Some patients in our study showed an increase of antibody titres soon after the intervention.After follow-up period, all patients had antibody titres less than before the procedure, and most of them had negative antibody titres.Our results of level of antibody titres are similar to the results of other studies (, ).Routine culture of the aspirated fluid to detect possible bacterial infection or contamination is also done in more investigations (, , , , ).In our study, microbiologic examinations were negative.There were no serious complications from the interventions.The reason is probably that modified PAIR is less agressive in realation to classic PAIR procedure and surgery treatment.
ENVER ZEREM ET AL.: MODIFIED PAIR TECHNIQUE FOR TREATMENT OF HYDATID CYSTSIN THE SPLEEN