Prostatic Urethral Lift: Does Size Matter?

Introduction

Lower urinary tract symptoms (LUTS) secondary to benign prostatic hypertrophy (BPH) are seen in 20% of men within the age range of 30–79. ^1,2 Medical therapies, including α-blockers and 5-α reductase inhibitors, have shown moderate efficacy in symptom relief. However, these medications are associated with unwanted side effects that include lightheadedness, decreased libido, erectile dysfunction, and ejaculatory dysfunction. ³ Inadequate symptom relief and adverse complications of such therapies cause 25% of these men to opt for surgical intervention. ⁴

Transurethral resection of the prostate (TURP) is the gold standard intervention for treatment of BPH. ⁵ However, this procedure has several well-known adverse effects, including urinary incontinence, erectile dysfunction, and retrograde ejaculation. ³ In fact, a significant proportion of men opt against both medical and interventional treatment due to the perception that complications of treatment will negatively impact quality of life more so than the symptoms of BPH itself. ⁶

The prostatic urethral lift (PUL) is a minimally invasive transurethral endoscopic procedure that involves placing small implants to retract the prostatic tissue and relieve BPH-related obstruction. A 12-month prospective randomized controlled trial showed PUL allowed better preservation of ejaculation and sexual function compared with TURP. Both treatments resulted in significant reduction of symptoms. This study also established the superiority of PUL based on comprehensive analysis of LUTS relief, recovery experience, erectile function, ejaculatory function, continence preservation, and safety. ⁷ Recently, this superiority was shown to be durable for 2 years and that the composite endpoint correlated with PUL showing superiority in overall health-related quality of life, as defined through the SF-6D validated instrument. ⁸

In 2013, PUL was FDA approved for patients with small to medium prostate size (≤80 g) without cystoscopic evidence of an obstructing median lobe. This approval was primarily based on the L.I.F.T. study, which only included patients with 30 to 80 g prostate sizes and excluded patients with median lobe obstruction. ^9,10 Roehrborn et al. demonstrated that, while response to PUL was dependent on baseline AUA symptom score (AUASS), it was independent of prostate volume within this limited range. ¹¹ There is a paucity of studies that have analyzed Urolift efficacy in patients with prostate sizes larger than 80 g. This study looks to evaluate if PUL can be as effective on larger prostates.

Materials and Methods

Seventy-four patients were identified who had undergone PUL between April 2, 2014, and December 2, 2015, and had available prostate volume data as measured with preoperative transrectal ultrasound. Patients without available prostate volume data were excluded. All PUL were performed by the senior author at a single institution, and the data include this surgeon's very first PUL cases. PUL was offered as an option to all patients over other bladder outlet procedures to maintain ejaculatory and sexual function. Three patients were catheter dependent before the PUL procedure. None of the patients had undergone a prior outlet procedure.

The AUASS is a validated questionnaire that evaluates the severity of voiding symptoms, including frequency, nocturia, weak urinary stream, hesitancy, intermittency, incomplete emptying, and urgency. ³ Each patient's medical records were reviewed for patient age at date of procedure, AUASS before procedure, presence of an obstructive median lobe at the time of surgical intervention, number of PUL implants used during the procedure, AUASS at postoperative follow-up, and any repeat outlet procedures performed after PUL.

Patient data were divided into two groups for analysis: (1) data from the 51 patients with prostate sizes less than or equal to 80 g (median: 46 g, range: 20–78 g) and (2) data from the 23 patients with prostates larger than 80 g (median: 112 g, range: 81–254 g). Subgroup analysis was performed evaluating only those patients who had failed PUL and required a repeat outlet procedure.

Deidentified patient data were stored on a Microsoft Excel 2010 (Microsoft Corp, Redmond, WA) spreadsheet. Univariate analysis using Student t-tests and Fisher's exact tests was used to compare continuous and categorical variables, respectively, including demographic, operative, and outcome data. A p-value less than 0.05 was considered statistically significant.

Results

Among the 74 patients in this cohort, preoperative and postoperative AUASSs were available in 73 (99%) and 69 (93%), respectively. Obstructive median lobes were identified in six patients on preoperative cystoscopy (one in the small prostate group, five in the large prostate group) and all six patients underwent either GreenLight laser ablation (GLL) or transurethral resection (TUR) of only the intravesical segment of the median lobe simultaneously with the PUL procedure.

Table 1 compares demographic, preoperative, intraoperative, and postoperative characteristics between those patients with small prostates (≤80 g) and those with large prostates (>80 g). A statistically significant difference between the number of PUL implants used and the percentage of patients with an obstructive median lobe was seen between the two groups. A significant improvement was seen between pre- and post-PUL AUASSs in both the 80 g and under prostate group (p < 0.001, median improvement: 9 points) and the over 80 g prostate group (p < 0.001, median improvement: 9 points) following the procedure. No significant differences in age, AUASS before or after the procedure, or need for an additional outlet procedure were identified between the two groups. On average, one implant was placed per 20.73 g of prostate tissue (15.7 g/implant in the small prostate group and 24.4 g/implant in the large prostate group, p < 0.001). Median follow-up time between the date of PUL procedure and the most recent AUASS was 144 days.

Seven (9%) of the 74 patients had complaints of decreased ejaculation following their PUL procedure, and all seven were in the small prostate group. Zero of these patients had their median lobe resected during the PUL procedure. Eight patients (11%) had persistent LUTS, including two with postoperative retention, resulting in a repeat outlet procedure following PUL. All three patients who had preoperative retention had complete resolution of their retention following completion of their procedure. The median time between these patients original PUL procedure and their repeat outlet procedure was 289 days. Three of these eight patients had a prostate size of >80 g with an overall median prostate size of 55 g. Zero of the eight patients had median lobes on cystoscopy. Six of these eight patients underwent subsequent GLL, one underwent a channel TURP, and one had a repeat PUL procedure with four more implants placed. Only the channel TURP required a repeat TURP 4 months later for persistence of LUTS. In review of the operative notes, no difficulties with repeat outlet procedure were encountered. A significant difference between the median age of those patients who failed PUL (median: 75.5) and those who did not (median: 69.5) (p = 0.001) was seen. No differences in median preoperative AUASS (13 vs 13), median prostate size (55.0 mL vs 54.8 mL), or number of implants (3 vs 4) were seen between the failed and successful PUL groups, respectively.

Discussion

The PUL is a nonthermal technology that offers a safe and viable option in the treatment of BPH. The implants used provide a mechanical approach to retract the obstructing lateral lobes, thus creating an open, continuous anterior channel within the prostatic urethral for urine to flow. ¹² Unlike other outlet procedures, the PUL works to preserve the urethral mucosa, and, in doing so, prevents distortion of the bladder neck anatomy and preserves antegrade ejaculation.

Woo et al. ¹³ were the first to show the effectiveness of the PUL procedure, with 3 of 19 patients requiring subsequent TURP at 1 year, one of whom had an untreated obstructive median lobe. This study was later expanded to a 64-patient study that excluded patients with obstructive median lobes or active retention. A large variation in technique was seen between the patients, and the authors noted that their techniques were significantly refined after the first 25 patients. Overall, these patients experienced an average 14.2-point improvement in symptom scores. Reintervention rate improved over the series as the procedure was refined, with a 2-year reintervention rate of 20% overall that improved to 8% in the final 39 patients treated. ¹⁴ The largest trial to date, the randomized control L.I.F.T. study that involved 206 subjects with prostates between 30 and 80 g with no obstructive median lobes, showed a reintervention rate of 5% at 1 year and 7.5% at 2 years, rising to 13.6% at 4 years. ¹² This trial demonstrated a sustained 9.2-point improvement in symptom scores at 2 years. ⁸ Our study demonstrated a higher retreatment rate than the L.I.F.T. study (11% at 1 year). This could be due to the less stringent exclusion criteria in this study, which did not exclude patients with an obstructive median lobe, large prostates, or patients in active retention. Our 9-point improvement in voiding symptom scores is on par with that of the L.I.F.T. study.

Gratzke et al. directly compared PUL vs TURP in a prospective, multicenter, randomized study. ⁸ Although this study limited patients to ≤60 g in size, it showed superior ejaculatory function preservation in the PUL arm, although ejaculatory function bother scores did not change significantly in either treatment arm. Assessment of postoperative ejaculatory function was not within the study primary endpoints of our series, as the benefits of PUL on ejaculatory function are already well known in the literature. ^8,11,14 Still, it is interesting to note that despite all of our patients undergoing the PUL procedure because of concern for maintenance of ejaculatory function, seven (9%) of the patients in our series still had complaints of a decrease in ejaculate following completion of their procedure, and all seven were within the small prostate group. The reason for this is unclear, but could be related to the higher number of implants per gram of prostate tissue seen in the small prostate group. Interestingly, none of the patients who underwent TUR of the intravesical median lobe had ejaculatory compromise. This could be related to efforts to maintain the integrity of the bladder neck during resection.

In our series, a significant difference was seen in the number of patients who had an obstructive median lobe during cystoscopic evaluation between the small and large prostate groups. During preoperative cystoscopy, six patients were identified with an obstructing median lobe (one in the small prostate group, five in the large prostate group) and all six patients underwent either GLL or TUR of only the intravesical portion of the median lobe at the time of PUL. Previous studies excluded patients with obstructive median lobes as it was felt these patients were more challenging to treat. ^7,8,13,15 Interestingly, in our study, all patients with obstructing median lobes underwent simultaneous TUR or GLL of the median lobe with their PUL to preserve the bladder neck and subsequently preserve anterograde ejaculation. Zero of the six patients required an additional outlet procedure at most recent follow-up.

To date, FDA restrictions on PUL based on prostate size and absence of a median lobe lack scientific bases and rather have been solely based on the fact that the pivotal PUL studies all had prostate size restrictions. This study attempted to analyze patients outside of this restricted zone and have found a sufficient number of patients with larger prostates who appear to have benefited from the PUL procedure.

While this study attempted to analyze the impact of prostate size on PUL, there are some limitations. The retrospective nature of this study leaves it open to analytical bias. No objective definition of median lobe protrusion was used during these procedures, and this was based primarily on surgeon experience. In addition, the use of GLL or TUR of the intravesical portion of the median lobe could have contributed to the efficacy of the procedure, as none of the failures had median lobes seen during prior cystoscopy. Because of variations in follow-up between patients, these data may not accurately reflect all patients who may eventually need another outlet procedure. Patient sexual history relating to erectile function before or after the procedure was not accurately documented in the charts and thus any impact of PUL or TUR of the median lobe on sexual function cannot accurately be deduced from this study. Longer follow-up is needed to evaluate for differences in the durability of the PUL procedure between patients with small and large prostate sizes.

Conclusions

Early experience finds that a sufficient number of men with larger prostates appear to benefit from PUL. Patients with prostates greater than 80 g in size are more likely to have an obstructive median lobe and may benefit from resection or ablation of the intravesical portion of this lobe at the time of PUL. Longer follow-up is needed to evaluate the durability of the PUL in patients with greater than 80 g prostate sizes.