title: Ablative efficiency of 532-nm laser vaporization compared to transurethral resection of the prostate: results from a prospective three-dimensional ultrasound volumetry study.
abstract: OBJECTIVE
  To assess and compare postoperative prostate volume changes following 532-nm laser vaporization (LV) and transurethral resection of the prostate (TURP). To investigate whether differences in volume reduction are associated with differences in clinical outcome.
  
  
  METHODS
  In this prospective, non-randomized study, 184 consecutive patients undergoing 120 W LV (n = 98) or TURP (n = 86) were included. Transrectal three-dimensional ultrasound and planimetric volumetry of the prostate were performed preoperatively, after catheter removal, 6 weeks, 6 and 12 months. Additionally, clinical outcome parameters were recorded. Mann-Whitney U test and analysis of covariance were utilized for statistical analysis.
  
  
  RESULTS
  Postoperatively, a significant prostate volume reduction was detectable in both groups. However, the relative volume reduction was lower following LV (18.4 vs. 34.7 %, p < 0.001). After 6 weeks, prostate volumes continued to decrease in both groups, yet differences between the groups were less pronounced. Nonetheless, the relative volume reduction remained significantly lower following LV (12 months 43.3 vs. 50.3 %, p < 0.001). All clinical outcome parameters improved significantly in both groups. However, the maximum flow rate (Q max) and prostate-specific antigen (PSA) reduction were significantly lower following LV. Subgroup analyses revealed significant differences only if the initial prostate volume was >40 ml. Re-operations were necessary in three patients following LV.
  
  
  CONCLUSIONS
  The modest but significantly lower volume reduction following LV was associated with a lower PSA reduction, a lower Q max and more re-operations. Given the lack of long-term results after LV, our results are helpful for preoperative patient counseling. Patients with large prostates and no clear indication for the laser might not benefit from the procedure.
authors.affiliation: Department of Urology, University Hospital Zürich, Frauenklinikstr. 10, 8091, Zurich, Switzerland, thomas.hermanns@usz.ch.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hermanns
authors.forename: Oliver
authors.initials: O
authors.lastname: Gross
authors.forename: Benedikt
authors.initials: B
authors.lastname: Kranzbühler
authors.forename: Lukas J
authors.initials: LJ
authors.lastname: Hefermehl
authors.forename: Cédric
authors.initials: C
authors.lastname: Poyet
authors.forename: Alexander
authors.initials: A
authors.lastname: Müller
authors.forename: Stanley A
authors.initials: SA
authors.lastname: Yap
authors.forename: Maurice S
authors.initials: MS
authors.lastname: Michel
authors.forename: Daniel
authors.initials: D
authors.lastname: Eberli
authors.forename: Michael
authors.initials: M
authors.lastname: Müntener
authors.forename: Matthias
authors.initials: M
authors.lastname: Zimmermann
authors.forename: Tullio
authors.initials: T
authors.lastname: Sulser
authors.forename: Hans-Helge
authors.initials: HH
authors.lastname: Seifert
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D021621:Imaging, Three-Dimensional; D053685:Laser Therapy; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011446:Prospective Studies; D011467:Prostate / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D011468:Prostatectomy / Q000379:methods*; D011470:Prostatic Hyperplasia / Q000601:surgery*; D020728:Transurethral Resection of Prostate; D014463:Ultrasonography