Persistance of storage luts after Greenlight™ prostate laser therapy: Not only a matter of technique

Aim of the study: Functional outcomes after GreenLightTM prostate laser therapy are still debatable. Aim of our study was to evaluate the influence of energy delivered and vaporization time on short-term and long-term LUTS recovery. Materials and methods: We prospectively evaluated patients under- went prostate photovaporization (PVP) or anatomical photovaporiza- tion (APV) for LUS due to benign prostate enlargement (BPE). All the procedures were performed by 2 experienced surgeons (more than 100 procedures) with a GreenLight laser XPS. APV was carried out as previously described by Gomez Sancha. Patients were preoperatively assessed according to prostate volume, prostatic specific antigen (PSA), International prostate symptom score (IPSS) and maximum urinary- flow rate (Qmax). Operative data included energy delivered, vapor- ization time and operative length. Postoperative data were recorded at 3, 6 and 12 months. Comparisons were made using unpaired t-tests for continuous variables and multivariate logistic regression. Results: Overall, 214 patients were evaluated: 85 treated with AVP and 129 with PVP. Mean prostate volume was significantly higher in AVP compared with PVP group (76,6 ± 17,36 Vs 59,1 ± 10,4 cc; p = 0,001). Preoperative IPSS and QMax were similar between groups ( p > 0.05). Mean energy delivered (194651,1 ± 80025,2 Vs 171674,4 ± 57585,3 J; p=0,015) and vaporization time (22,6±8,3 Vs 20,3±6,2 min; p= 0,026) were significantly higher in AVP group. However, operative length was similar between the 2 groups (58,2 ± 21 Vs 55,2 ± 18 min; p>0,05). Six months after surgery IPSS (6,81±1,5 Vs 6,68±1,5; p = 0,54) and Qmax (21,2 ± 3,01 Vs 21,9 ± 3,18; p = 0,138) were alike between groups, independently from the technique, with a clinically significant improvement when compared to preoperative values. However, a statistically significant association was found between the amount and time of energy delivered and higher IPSS ( p = 0,047 and p = 0,044; fig.1a-b). At subscore analysis only storage IPSS retained a statistically significant correlation with energy and time ( p = 0.01) conversely to voiding IPSS ( p > 0.05). At 12 months follow-up both IPSS and Qmax persisted similar between groups, and, interestingly, energy delivered was associated with lower IPSS ( p = 0,002), while vaporiza- tion time lost its significance ( p > 0,05) ( fig.1c-d). Storage IPSS was no more associated with time and energy. Discussion: Irrespective of the adopted technique (PVP or AVP), energy delivered and vaporization time were associated with worst functional outcomes 6 months after surgery, majorly due to persistent storage LUTS, and better at 12 months fw. These data could be linked with the inflammation triggered by the amount of energy delivered and useful for postoperative patients counseling.