title: Prostate volume reduction following pure transurethral bipolar plasma vaporization and conventional transurethral resection of the prostate: a prospective investigation using transrectal 3D ultrasound volumetry.
abstract: OBJECTIVE
  To evaluate and compare postoperative changes in prostate volume and clinical outcome after bipolar plasma vaporization (BPV) and conventional transurethral resection of the prostate (TURP).
  
  
  METHODS
  Consecutive series of patients undergoing BPV or TURP were included in this prospective, nonrandomized study. Planimetric volumetry after transrectal three-dimensional ultrasound of the prostate was performed preoperatively and postoperatively after 6 weeks, 6 months and 12 months. Additionally, changes in clinical outcome parameters were assessed and compared between the groups. The reduction ratio and analysis of covariance were used to compare volume changes between BPV and TURP. Multiple regression analysis was performed to assess a possible interaction between preoperative prostate volume and effect of therapy.
  
  
  RESULTS
  A total of 157 patients were included (BPV: n = 68, TURP: n = 89). Median preoperative prostate volume was 43.1 ml in the BPV group and 45.9 ml in the TURP group (p = 0.43). Postoperatively, the prostate volumes decreased significantly in both groups. After catheter removal, the relative residual prostate volume was significantly higher in the BPV group (66.6 vs. 60.8 %; p = 0.02). Thereafter, significant differences were not detectable anymore (12 months: 46.6 vs. 47.1 %; p = 0.82). Regression analysis revealed that tissue ablation after BPV was superior to TURP in prostates <45 ml but inferior in prostates >45 ml. All clinical outcome parameters improved significantly and were not significantly different between the groups.
  
  
  CONCLUSIONS
  Volume reduction and short-term clinical outcome following pure BPV was excellent and comparable to conventional TURP. However, volume reduction seems to be limited in patients with larger prostates.
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Kranzbühler
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
authors.forename: Oliver
authors.initials: O
authors.lastname: Gross
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
authors.forename: Christian D
authors.initials: CD
authors.lastname: Fankhauser
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
authors.forename: Marian S
authors.initials: MS
authors.lastname: Wettstein
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
authors.forename: Nico C
authors.initials: NC
authors.lastname: Grossmann
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
authors.forename: Lukas J
authors.initials: LJ
authors.lastname: Hefermehl
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Zimmermann
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
authors.forename: Alexander
authors.initials: A
authors.lastname: Müller
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Eberli
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
authors.forename: Tullio
authors.initials: T
authors.lastname: Sulser
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
authors.forename: Cédric
authors.initials: C
authors.lastname: Poyet
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland. thomas.hermanns@usz.ch.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hermanns
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004598:Electrosurgery / Q000379:methods*; D019160:Endosonography; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011446:Prospective Studies; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D011470:Prostatic Hyperplasia / Q000150:complications / Q000601:surgery*; D012044:Regression Analysis; D020728:Transurethral Resection of Prostate / Q000379:methods*; D001748:Urinary Bladder Neck Obstruction / Q000209:etiology / Q000601:surgery*
keywords: 3D imaging; Benign prostatic hyperplasia; Transurethral electrovaporization of prostate; Transurethral resection of prostate; Ultrasound of the prostate