Endoscopic enucleation of the prostate has been the gold standard in treatment of bladder outlet obstruction with large prostate since 2016. [10]
The adaptation of prostatic enucleation technique is boosted by the familiarity with the finger assisted anatomical enucleation of the adenoma during open prostatectomy. [11]
It is to be considered that only energy-free blunt dissection following the plane of surgical capsule is entitled anatomical enucleation, that is different from other energy based transurethral enucleation techniques where the plane of the capsule is created by the energy. The concept of anatomical enucleation (widely energy free technique) can be performed by any type of energy (thulium, holmium, or bipolar). [12]
Thulium laser appears as an excellent source of energy for endoscopic prostatic enucleation as it offers a clear and bloodless incision in the prostatic tissue. It also demonstrates excellent hemostatic properties needed for adequate coagulation of penetrating vessels. It has a narrow penetration depth that protects pericapsular tissue from excessive energy exposure. Bach et al in 2009 published the technique of prostatic vapoenucleation using thulium laser. [5]
Herrmann et al. in 2010 proposed the concept of anatomical enucleation using thulium energy by widely blunt dissection of the adenoma. [6] The blunt energy free enucleation decreases the risk of capsular perforation, energy scattering to pericapsular tissue and diminish postoperative irritative symptoms. [11]
Transurethral bipolar (plasmakinetik) enucleation of the prostate was firstly described in 2004 by the same group who described HOLEP. [10] A randomized controlled study in 2006, found that bipolar enucleation (BipoLEP) was equivalent to HOLEP, [13] other two meta-analysis studies in 2015 [14, 15] confirmed the efficacy of the enucleation technique. These studies found that HoLEP and BipoLEP are equivalent to open prostatectomy regarding intraoperative and postoperative safety, and efficacy to relief obstructive symptoms during long term follow up. The 2016 updates to the guidelines of the European Association of Urology viewed both HOLEP and bipolar enucleation as the primary treatments for obstructive symptoms resulting from a large prostate (over 80 gm). [10]
In this era, where there are many types of laser generators of different power, the question was raised if lasers are essential for anatomical enucleation in the presence of a less costly but equally effective option like bipolar enucleation. This study aims to compare the use of bipolar current and thulium laser in endoscopic enucleation.
Comparing between techniques, a prospective randomized study (133 patients) was done by Zhang et al. to compare between ThuLEP (using 70 W) and HoLEP (using 90 W) with 18 months follow-up period. They found no significant differences between both techniques regarding improvement of urinary symptoms. They reported that blood loss was lower but operation time was longer statistically in ThuLEP than in HoLEP but the differences were clinically insignificant. [16]
In the same line, a meta-analysis study done by Xiao KW et al. including five independent studies comparing ThuLEP vs. HoLEP. They didn’t find any significant differences between both techniques regarding operation time, enucleation time, hemoglobin drop, and hospital stay. [17]
The continuous wave mode of the Thulium:YAG laser provide faster enucleation than the pulsed mode of the Holmium:YAG laser, this could be explained by that the depth of the wavelength of the thulium laser is close to the water absorption which is the main absorbing substance of the prostate; resulting in high energy absorption rate. [17]
Iacono et al. studied the functional outcomes of ThuLEP (120 W/40 W) of 148 patients in a retrospective study with follow up 12 months. They found significant improvement of all functional parameters. [18] Gross AJ et al. carried out a prospective study of 1080 patients undergoing ThuVEP. They also found significant improvement of all parameters in all groups. [19] Netsch C et al. found the same results in their prospective analysis of 124 patients who underwent ThuVEP. [20]
A systemic review and meta-analysis comparing ThuVEP/ThuLEP (TmLRP) with TURP was done by Zhu et al. They analyzed seven studies (four RCTs and three non-RCTs). They found the improvement of Qmax and IPSS favored ThuVEP/ThuLEP while PVR and QoL were not significantly different [21]
On the other side, Chunxiao Liu et al. published the effectiveness bipolar enucleation (BEEP) in a series of 1.100 patients with a median follow up of 4.5 years. They found significant improvement of all parameters. [7] Lingfeng Zhu et al. comparing bipolar EEP vs. TURP in a randomized clinical trial (RCT) with 80 patients, demonstrated the same improvement of urinary symptoms with greater resected prostate tissue, less blood, shorter catheterization time, and postoperative hospital stay, in favor of BEEP. [22]
Along the same lines, Arcaniolo et al. A meta-analysis was conducted, involving 14 comparative studies (comprising of 5 RCTs, 2 prospective non-randomized cohort studies, 1 analysis with propensity score matching, and 6 retrospective cohort studies). The total number of subjects included in the analysis was 2317 (with 1178 patients for BEEP and 1139 for bipolareTURP). They found no differences in operative time, but there was a higher amount of resected tissue, and a shorter bladder irrigation, hospital stay and catheter time for BEEP with clear superiority of BEEP in functional outcome. [23]
Our study was on the same line with the above studies as we found significant comparable improvement in IPSS score, urinary Q max, and PVR postoperatively in both groups at all follow up points. There were no differences in Q max, IPSS and PVR in both groups at different follow up points either in postoperative values or in the percentage of improvement from baseline measures, There were no significant differences regarding hospital stay, time of catheter removal, and intraoperative blood loss expressed by hemoglobin change.
The incidence of transient postoperative stress urinary incontinence depends on many factors after enucleation, such as pre-existing overactive bladder, the learning curve, the volume of the prostatic gland and pre-existing neurologic conditions. We fixed all these parameters in our study to can detect the actual differences.
In a retrospective multi-central analysis involving 2346 patients after HoLEP, Houssin V et al. concluded that urinary stress was observed in 14.5% of patients at 3 months, and in 4.2% of patients at 6 months postoperatively. [24]
Regarding the continence anatomical structure, we used the technique of enucleation with early separation of apical mucosa from the sphincter during bipolar or Thulium enucleation.
We found after one month, urgency urinary incontinence in 34 (56.7%) cases in ThuVEP and 14 (23.3%) cases in enucleation group respectively (P value 0.001), and stress urinary insentience was in 44 (73.3%) cases in ThuVEP and 26 (43.3%) cases in enucleation group respectively (P value 0.001).
A retrospective analysis of 584 patients after undergoing bipolar enucleation of the prostate by Hirasawa et al found cited postoperative transient urine incontinence in 17.3%, 13.5%, 3.1%, 0.41%, and 0%, at 1, 3, 6, and 12 weeks, respectively, where age and prostate volum were significant factors. [25] Kyriazis et al, with a review of literature for ThuLEP procedures, found transient irritative symptoms between 6.7% and 18.5%, with no patient reporting symptoms at the end of study period. [11]
In our study, there were no significant differences between both groups regarding intraoperative and postoperative complications. In the study by Iacono et al, they found only 2.7% of the patients with ThuLEP early post-surgery blood transfusions were required because of ongoing hematuria, urinary tract infection occurred in 12.8% of patients, and two patients developed urethral stricture treated by cold incision.[18] Chunxiao Liu et al reported that meatal stenosis occurred in nine cases out of 1100 BiPoLEP in 56 patients, urinary incontinence was observed, while urethral stricture affected 12 individuals. Only 10 patients experienced bladder neck contracture. within a 6-year follow up.[7] The study by Gross AJ et al. reported that the most frequent early complications in cases with ThuVEP urinary retention occurred in 9% of cases, and re-intervention (such as repeat morcellation, secondary apical resection, and clot removal) was required in 4.7% of instances the patients. and hemorrhage requiring blood transfusion in1.7%, they reported that he complications rate was prostate size-dependent. [19]
Our study comparing ThuVEP and bipolar enucleation, we found almost the same improvement of all clinical parameters with the same low incidence of intraoperative and postoperative surgical complications, but still we need longer follow up for our patients. These results may raise the previous question if we still need these expensive types of laser with the presence of less costly and same effective option like bipolar enucleation.