title: Single-session alcohol-retention sclerotherapy for simple renal cysts: comparison of 2- and 4-hr retention techniques.
abstract: OBJECTIVE
  The objectives of our study were to evaluate the feasibility of ethanol sclerotherapy in treating simple renal cysts with prolonged ethanol retention and to compare the therapeutic results of 2- and 4-hr retention techniques.
  
  
  METHODS
  We retrospectively reviewed 36 renal cysts in 33 patients treated by ethanol sclerotherapy with a single-session single-injection technique during the past 6 years. After complete aspiration of the cystic fluid, 95% ethanol was injected into the cyst and was retained for 4 hr in 14 cysts (group 1) and for 2 hr in 22 cysts (group 2). The average maximal diameter and aspirated volume of the cysts were 8.3 cm and 223 mL in group 1 patients and 7.9 cm and 167 mL in group 2, respectively. The ablated cysts were followed up regularly by sonography, CT, or both at 3- to 6-month intervals for at least 1 year. The nonparametric Mann-Whitney U test was used to compare differences in characteristics, treatment results, and laboratory data of the subjects in the two groups. The level of statistical significance was set at a p value of less than 0.05.
  
  
  RESULTS
  Technically, all the patients tolerated the procedures. One patient had gross hematuria 10 days after the procedure. She underwent surgical deroofing treatment and was excluded in the later statistical analysis. After sclerotherapy, 14 cysts disappeared completely and 16 cysts showed marked regression with residual maximal diameter of less than 3 cm. The overall volume reduction rate was 97.6% in all 35 cysts. The mean residual longest diameters and average volume reduction rates of the treated cysts were 1.9 cm and 97.9% in group 1 patients and 1.1 cm and 97.3% in group 2 patients, respectively, which showed no statistical significance of volume reduction rate with a p value 0.149.
  
  
  CONCLUSIONS
  The single-session prolonged ethanol-retention technique is safe and efficacious for the treatment of renal cysts. There is no statistical difference in therapeutic efficacy between 2- and 4-hr ethanol-retention techniques.
authors.affiliation: Department of Radiology, Kaohsiung Veterans General Hospital, 386 Ta-Chung First Rd., Kaohsiung, Taiwan 813, ROC.
authors.forename: Yih-Huie
authors.initials: YH
authors.lastname: Lin
authors.forename: Huay-Ben
authors.initials: HB
authors.lastname: Pan
authors.forename: Huei-Lung
authors.initials: HL
authors.lastname: Liang
authors.forename: Hsiao-Min
authors.initials: HM
authors.lastname: Chung
authors.forename: Chiung-Yu
authors.initials: CY
authors.lastname: Chen
authors.forename: Jer-Shyung
authors.initials: JS
authors.lastname: Huang
authors.forename: Kang-Ju
authors.initials: KJ
authors.lastname: Chou
authors.forename: Clement K-H
authors.initials: CK
authors.lastname: Chen
authors.forename: Pin-Hong
authors.initials: PH
authors.lastname: Lai
authors.forename: Chien-Fang
authors.initials: CF
authors.lastname: Yang
mesh_terms: D000328:Adult; D000368:Aged; D002648:Child; D000431:Ethanol / Q000493:pharmacokinetics*; D005119:Extravasation of Diagnostic and Therapeutic Materials / Q000000981:diagnostic imaging; D005240:Feasibility Studies; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000000981:diagnostic imaging / Q000628:therapy*; D008875:Middle Aged; D015641:Radiography, Interventional; D012189:Retrospective Studies; D012597:Sclerosing Solutions / Q000493:pharmacokinetics*; D015911:Sclerotherapy / Q000379:methods*; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
chemical_list: D012597:Sclerosing Solutions; D000431:Ethanol