“Laser vaporization of the prostate: A comparative study between ejaculatory preserving and non-ejaculatory preserving technique”

ABSTRACT

Introduction and objectives

Laser vaporization techniques have emerged as a prominent alternative to transurethral prostate resection in managing benign prostatic obstruction (BPO). This study focuses on assessing the effectiveness of the ejaculatory preserving laser vaporization of the prostate technique compared to the conventional non-ejaculatory approach in managing BPO.

Patients and Methods

Our study was performed between August 2022 and September 2023. The study included 120 patients with bladder outlet obstruction, due to benign prostatic hyperplasia (BPH). Patients were randomly assigned to two groups: the first underwent conventional non-ejaculatory preserving laser vaporization of the prostate (n = 80), while the second group underwent the innovative ejaculatory preserving laser vaporization technique using diode laser (n = 40). We assessed baseline International Prostate Symptom Score (IPSS), maximal flow rate (Qmax), post voiding residual urine volume (PVRU), semen volume (semen analysis). Parameters were re-evaluated 3 months post-surgery and the change in sexual satisfaction was evaluated using a scale from 1 (much less satisfied) to 5 (much more satisfied) in response to a question.

Results

The mean age (±SD) of participants was 59.6 (±7.9) and 57.6 (±7.8) for the non-ejaculatory preserving and ejaculatory preserving groups, respectively, with no statistical difference between groups. Both groups showed significant reduction in IPSS (p < 0.001), improvement in Qmax (p < 0.001), and decline in PVRU (p < 0.001), postoperatively. However, the ejaculatory preserving technique led to a significant improvement in antegrade ejaculation, postoperative semen volume and sexual satisfaction compared to the non-ejaculatory preserving technique (p < 0.001).

Conclusions

The ejaculatory preserving technique effectively preserved antegrade ejaculation, semen volume and sexual satisfaction compared to the non-ejaculatory preserving technique. However, the later yielded better outcomes in terms of IPSS and urine flow. Both techniques demonstrated significant improvements across all parameters compared to baseline. Further research with extended follow-up periods is needed to fully understand the long-term postoperative effects with this technique.

KEYWORDS:

• Prostate
• ablation techniques
• laser vaporization
• prostatic Hypertrophy
• ejaculatory preserving technique

Introduction

Transurethral resection of the prostate (TURP) has been widely practiced as a standard surgical procedure for managing BPO. It is considered the gold standard treatment due to its long history, proven success rates and low complication rates [1]. However, TURP is associated with certain risks mainly represented in bleeding complications and the potential occurrence of TUR syndrome. TUR syndrome is a rare but potentially serious condition caused by leakage of irrigation fluid into bloodstream during the surgical procedure. It could lead to asymptomatic hyponatremia, vomiting, confusion even coma and death [2].

To overcome the limitations and risks associated with the traditional surgical methods, advanced techniques and minimally invasive procedures have been developed. Laser vaporization of the prostate has emerged as a promising minimally invasive procedure for managing BPO [3]. This procedure involves utilizing laser energy to vaporize excess prostate tissue that is responsible for urinary symptoms. Laser vaporization offers several benefits, including reduced bleeding, shorter hospital stays and faster recovery periods compared to traditional surgical approaches [4].

In context of laser vaporization of BPO, a semiconductor typically created diode laser, commonly using wavelengths of 940, 980 and 1470 nm. Among these, the 980 nm diode laser that is known for its high absorption rates in water and hemoglobin, with a penetration depth of around 0.5 mm. Similarly to the 980 nm diode laser, the 1470 nm diode laser also exhibits high absorption rates, with a penetration depth ranging from 2 to 3 nm [4]. This absorption property enables a combination of tissue vaporization and controlled bleeding, providing a favorable balance between therapeutic efficacy and hemostatic capabilities [5].

Ejaculatory preserving laser vaporization of the prostate has a considerable advantage over other techniques, represented in its ability to preserve normal ejaculatory functions, which is a significant concern for many patients seeking treatment for BPH [6]. The ability to maintain normal ejaculatory function sets this technique apart from other procedures and addresses an essential aspect of patients’ quality of life.

By comparing the outcomes of ejaculatory preserving and non-ejaculatory preserving techniques, this study aimed to evaluate the relative benefits and effectiveness of these approaches, providing valuable insights for optimizing BPO treatment strategies.

Patients and methods

This study was a prospective, randomized clinical study, conducted at Ain shams University hospitals between August 2022 and September 2023. The study protocol was registered on www.Clinicaltrials.gov. Identifier: NCT06091618.

Patients with BOO owing to clinically confirmed BPH were randomized using closed envelope method in a ratio 2:1 into two groups, the first group: conventional non-ejaculatory preserving laser vaporization of the prostate was performed (n = 80), and the second group underwent ejaculatory preserving laser vaporization of the prostate (n = 40).

Sample size and power of the study

The sample size was calculated to achieve a statistical power of 80% at significance level of 0.05, taking into account the expected effect size and anticipated dropout rate.

Inclusion and exclusion criteria

Inclusion criteria for the study included men aged above 45 years with clinical diagnosis of BOO, an IPSS above 14, prostate size less than 80 gm estimated by pelviabdominal ultrasound, previous history of failed conventional medical treatment and a desire to maintain sexual function.

Exclusion criteria included the use of sexual function-altering medications, patients with major mental or somatic illness, difficulty or absence of ejaculation, prostate cancer, neurogenic bladder, significant comorbidities or high surgical risks and patients with prostate size above 80 gm.

A detailed preoperative work-up was conducted, encompassing history taking, physical examination, prostate ultrasound. Every patient got a thorough examination that included: neurological assessment, IPSS evaluation, erectile dysfunction assessment, uroflowmetry, semen volume estimation and ejaculatory outcomes were all categorized.

Operative procedure

The surgical procedure involved the use of ‘Diode laser’ to perform vaporization. We utilized Biolitec LEONARDO® DUAL 200 diode laser with power 200 Watt in continuous mode (1470 nm/40 Watt +980 nm/160 Watt) and XCAVATOR® fiber for prostate vapo-resection (Biolitec, Jena, Germany).

The following stages were performed to preserve ejaculation [7]

(1) A reference point was established with a cutout 1 cm proximal to the verumontanum and para-collicular tissues.

(2) The above-mentioned reference line was used as a guide for the complete excision of the middle lobe.

(3) Vapo-resection of the lateral lobes to the capsule and the ventral side to the verumontanum was performed till the reference point.

(4) Apical resection was performed with a 1cm safety zone in front of the verumontanum to protect ejaculatory function.

(5) Following complete prostatectomy, a comprehensive examination was conducted to ensure absence of any residual blockages.

The primary and secondary outcomes of this study were preservation of antegrade ejaculation and urinary function, respectively.

Patients were assessed, at baselines and followed for 3 months post-operatively, for the International Prostate Symptom Score (IPSS), semen volume, (PVRU), and (Qmax). Complications were described according to Clavien-Dindo classification [8]. Data from each group were compared and analyzed.

Postoperative sexual satisfaction was assessed using a question, with a scale ranging from 1 (Much less satisfied), 3 (no change) and 5 means (Much more satisfied). The question was ‘How satisfied are you with your sexual experience post-operatively compared to before the surgery?’

Ethics statement

The local research ethics committee (REC) approved the study under number: FMASU MD (179/2022). The study was performed according to the ethical declaration of Helsinki. All patients provided written informed consent.

Statistical analysis

Statistical analysis was performed with IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp. Numerical data were tested for normality using Kolmogorov-Smirnov and Shapiro-Wilk tests. Data were presented as median, range, mean and standard deviation (SD) values. For parametric data, Student’s t-test was used to compare between mean age values in the two groups. For non-parametric data, Mann-Whitney U test was used to compare between the two groups. Wilcoxon-signed rank test was used to study the changes post-operatively within each group. Qualitative data were presented as frequencies and percentages. Chi-square and Fisher’s Exact tests were used to compare between the two groups. The significance level was set at p value less than 0.05.

Results

Baseline characteristics

Patients were randomized to either of the two study groups, where 80 patients were randomized to non-ejaculatory preserving group and 40 patients were randomized to ejaculatory preserving group. However, owing to loss to follow-up, the final analyzed patient data included 76 patients from the non-ejaculatory preserving group and 38 patients from the ejaculatory preserving group (Figure 1).

Figure 1. Consolidated standards of reporting trials (CONSORT) flowchart of study cases.

In Table 1, baseline data showed that there was no statistically significant difference between the two study groups regarding all the following parameters: age, PSA, Prostate size, ASA score and intra operative estimated blood loss (p = 0.6330), and operation time (p = 0.0553). The age of the participants in our study spanned from 50 to 65 years with no statistical difference in the mean ages between the two groups. Also, patients were fit for anesthesia (ASA 1 or 2)

Table 1. Baseline Patients characteristics.

		Non-ejaculatory preserving (n = 76)	Ejaculatory preserving (n = 38)	P-value
Age (years) Mean (±SD)		59.6 (±7.9)	57.6 (±7.8)	0.208
PSA(ng/ml) Mean (±SD)		2.58 (±0.68)	2.48 (±0.73)	0.5044
Prostate size(gm)		60.88 (12.35)	60.78 (±11.84)	0.9677
ASA score n (%)	I	50 (65.8%)	23 (60.5%)	0.730
	II	26 (34.2%)	15 (39.5%)

*Significant at p value ≤ 0.05.

Statistical Test used: Student’s t-test.

International prostate symptom score (IPSS)

The non-ejaculatory preserving group demonstrated a significantly lower IPSS and a significantly higher percentage decline in IPSS group at the 3-month postoperative assessment compared to the ejaculatory preserving group (Table 2).

Table 2. Descriptive statistics and results for comparison between IPSS, Qmax, PVRU, semen volume and post operative sexual satisfaction findings and their Percentage increase in the two groups and the changes within each group.

		Non-ejaculatory preserving (n = 76)	Ejaculatory preserving (n = 38)	P-value
IPSS	Preoperative Mean(±SD)	21.7 (±3.1)	22 (±3)	0.574^b
	Postoperative Mean(±SD)	8.5 (±2.7)	12 (±5.1)	0.002^b*
	p-value	<0.001^d*	<0.001^a*
	% change Mean(±SD)	60 (±14.7)	45.2 (±22.6)	0.002^b*
Qmax (ml/sec)	Preoperative Mean(±SD)	10 (±1.8)	9.6 (±1.5)
	Postoperative Mean(±SD)	17.3 (±2.2)	15.1 (±3.7)
	p-value	<0.001^d*	<0.001^a*
	% change Mean(±SD)	78.8 (±36.2)	60.1 (±41.8)	0.023^b*
PVRU (ml)	Preoperative Mean(±SD)	109.5 (±62.9)	111.6 (±66.5)
	Postoperative Mean(±SD)	27.2 (±13.5)	41.8 (±35.3)
	p-value	<0.001^d*	<0.001^a*
	% change Mean(±SD)	67.3 (±21.7)	55.3 (±25.6)	0.009^b*
Semen volume (ml)	Preoperative Mean(±SD)	2.7 (±0.75)	2.8 (±0.65)
	Postoperative Mean(±SD)	1.1 (±0.26)	1.58 (±0.36)	<0.001^c*
	p-value	<0.001^d*	<0.001^d*
Post operative sexual satisfaction Grade n (%)	I	39 (51.3%)	0 (0%)	<0.001^e*
	II	36 (47.4%)	18 (47.4%)	1
	III	1 (1.3%)	20 (52.6%)	<0.001^e*

*.Significant at p value ≤ 0.05.

a: Wilcoxon signed-rank test

b: Mann-Whitney U test

c: Paired t test

d: Student t test

e- chi-square test

Q max

Both groups showed a statistically significant improvement in Qmax postoperatively. However, the non-ejaculatory preserving group had a notably greater percentage increase in Qmax compared to ejaculatory preserving group (Table 2).

Post voiding residual volume (PVRU)

Both groups showed a statistically significant decline in PVRU postoperatively, but the non-ejaculatory preserving group exhibited notably greater and significant percentage decrease in PVRU compared to the ejaculatory preserving group (Table 2).

Ejaculation

Preoperatively, all patients in both groups had normal antegrade ejaculation, thus no statistical comparison could be performed. Post-operatively, the non-ejaculatory preserving group had a significantly lower occurrence of normal ejaculation and had higher occurrence of low volume ejaculation or retrograde ejaculation and less sexual satisfaction compared to the ejaculatory preserving group (P-value <0.001, Effect size = 4.646). The prevalence of normal ejaculation declined significantly within each group postoperatively (Table 2).

Complications

In Table 3, we categorized postoperative storage symptoms (urgency, frequency, nocturia and dysuria) into sub-scores of mild (0–5), moderate [6–10] and severe scores [11–15]. Similarly, postoperative voiding symptoms (intermittency, weak stream and straining) were categorized into sub-scores: mild (0–6), moderate (score 7–13) and severe scores [9,14–20].

Table 3. Comparison between studied groups according to postoperative complications.

Complications		Non-ejaculatory preserving (n = 76)	Modified Clavien- Dindo classification and management	Ejaculatory preserving (n = 38)	Modified Clavien- Dindo classification and management	P-value	Effect size (OR)
Symptoms	Grading	n (%)		n (%)
Postoperative storage symptoms	Mild	57 (75%)	Grade I For follow up	0 (0%)	-	<0.001*	0.250
	Moderate	0 (0%)	-	8 (21.1%)	Grade II Required medical treatment for LUTS.	<0.001*	1.267
	Severe	0 (0%)	-	3 (7.9%)	Grade II Required medical treatment for LUTS.	0.035*	1.086
Post operative voiding symptoms	Mild	0 (0%)	-	9 (23.7%)	Grade I For follow up	<0.001*	1.31
	Moderate	0 (0%)	-	0 (0%)	-	-	-
	Severe	0 (0%)	-	0 (0%)	-	-	-
Retention		0 (0%)	-	5 (13.2%)	Grade IIIa Needs re-catheterization	0.003*	1.152
Post operative bleeding		(3.9%)	1 patient Grade I for follow up Hgb level. 1 patient Grade II and required blood transfusion.	1 (2.6%)	Grade I For follow up Hgb level	0.719	0.658

*Significant at p value ≤ 0.05.

OR: Odds Ratio done by Chi-square and Fisher’s Exact tests.

According to Clavien-Dindo classification [8], 75% of patients in non-ejaculatory preserving group presented with complications exhibited mild storage symptoms (Grade I) requiring only follow-up, at a rate significantly higher than ejaculatory preserving group. Conversely, in the ejaculatory preserving group, 21.1% of patients with complications had moderate symptoms, and 7.9% had severe symptoms both requiring medical treatment for LUTs (Grade II) and were significantly higher than the non-ejaculatory preserving group.

Regarding voiding symptoms, 23.7% of patients in ejaculatory preserving group had mild symptoms (Grade I) requiring follow-up. For retention symptoms, 13.2% required re-catheterization (Grade IIIa). Both were significantly higher than non-ejaculatory preserving group.

Additionally, only two patients (3.9%) in non-ejaculatory preserving group experienced non-significant minor postoperative bleeding with one requiring follow-up (Grade I), and the other blood transfusion (Grade II), compared to ejaculatory preserving group’s bleeding complications rate (2.6%), requiring only follow-up (Grade I).

Discussion

Bladder outlet obstructions (BOO) are mostly caused by benign prostatic hyperplasia (BPH) in aging males over 60 years-old. Surgical interventions, as transurethral resection of the prostate (TURP), have proven efficacy and accomplished substantial outcomes in managing BPO [10]. TURP has been the benchmark procedure for managing BPO and is known for its long-standing efficacy and safety. However, conventional TURP is associated with the loss of antegrade ejaculation, which could be a significant concern, particularly for sexually active patients [7].

To address this, the ejaculatory preserving TURP (epTURP) was developed. This technique aims to preserve ejaculatory function while maintaining similar outcomes for urinary parameters [7,11]. However, both TURP and epTURP can lead to post-operative complications, such as TUR syndrome, longer operation duration, bleeding complications, and risks of blood transfusion [12].

To mitigate these complications, advanced laser ablation techniques like photo selective vaporization of the prostate using Potassium-titanyl phosphate (KTP) laser and holmium laser enucleation of the prostate (HoLEP) have been developed as alternatives to traditional TURP [3]. Previous studies demonstrated that laser energy precisely ablated prostate tissue and achieved relief in BPO symptoms, while reducing bleeding risk and complications associated with traditional surgeries like TURP and epTURP [13,14].

Laser vaporization techniques aim at minimizing the risk of post-operative ejaculatory dysfunction compared to TURP [15]. These techniques target laser energy precisely, thus involve careful preservation of anatomical structures responsible for ejaculation while treating enlarged prostate tissue [14]. Transitioning to laser vaporization offered higher likelihood of preserving ejaculatory function for prostate surgery patients [3].

Previous studies utilized the diode laser photo vaporization of the prostate for managing BPO and demonstrated efficacy in outcomes but did not compare between ejaculatory versus non-ejaculatory preserving technique [16,17].

In our current study, we assessed the effectiveness of the employed techniques by evaluating the IPSS, Qmax, PVRU, and the ejaculatory function at baseline. Subsequently, we compared the obtained results between the two groups and re-evaluated these parameters 3 months after the surgical procedure. There were no significant differences in the demographic parameters between the study groups.

International prostate symptom score (IPSS)

In 2009, Erol et al. utilized a 980 nm diode laser for prostatectomy. In accordance with our results, they mentioned significant reduction in IPSS 3 months postoperatively, and reported better improvement 6-month post-surgery [16]. In their randomized trial, Bouchier-Hayes et al. similar results were observed regarding IPSS when compared to ours. Their trial compared photo vaporization of prostate using 80-W KTP laser to TURP for managing BPO. However, they concluded that laser vaporization of prostate was comparable to TURP in terms of decreasing IPSS [14].

In 2018, Mithani et al. conducted a prospective study in patients with BOO secondary to BPH, where they employed comparable diode laser photo vaporization of the prostate technique. They evaluated the outcome parameters at 3 and 6 months postoperatively. In accordance with our results, they reported a significant decrease in IPSS 3 months postoperatively in all their patients. They mentioned that this decrease was sustained 6 months postoperatively [17].

Destefanis et al. compared between ejaculation‑sparing and non‑ejaculation‑ sparing Greenlight laser photo vaporization of the prostate in managing BPO, and mentioned similar results as ours where there were no significant differences in IPSS between their 2 groups at baseline, however, postoperatively both groups demonstrated significant decrease in IPPS with no significant differences between them [15].

Uroflowmetry (Qmax) data

Bouchier-Hayes et al. reported significant increase in Qmax in both study groups at all time intervals compared to the baseline. However, their findings differed, as the increases in Qmax in both of their study groups were equivalent with no superiority of a group than another [14]. These variances from our study could be attributed to the differences in study design, surgical techniques or patient population.

In the 2018 study, Mithani et al. mentioned a significant improvement in Qmax 3 months postoperatively compared to baseline, as recorded in our results. They added that this improvement was maintained 6 months post-operatively [17]. These findings support our own results regarding improvement in Qmax following photo vaporization of the prostate.

Post voiding residual urine (PVRU)

Rouf et al. evaluated ejaculation preserving HoLEP versus epTURP for managing BPO and utilized same technique in the ejaculatory preserving group as per our study, which involved preserving the parafollicular tissue and avoiding deep resection behind the verumontanum. They reported significant reduction in PVRU postoperatively compared to baseline, mirroring our results [11].

In Trama et al. study in 2022, researchers assessed the effectiveness of ejaculatory-sparing thulium laser enucleation of the prostate for managing LUTS associated with BPH in sexually active patients. Differently, their study only included a single group of patients who underwent ejaculatory preserving technique with no control group as per our study. Similar to our results they reported significant decrease in postoperative PVRU compared to baseline [18].

However, Bouchier-Hayas et al. reported a non-significant difference in PVRU reduction between their study groups [14].

Ejaculation

Abolazm and colleagues utilized ejaculatory hood sparing technique and compared it with the standard green laser photo vaporization of the prostate. They reported that antegrade ejaculation was observed in 85% of patients who underwent hood-sparing photo vaporization of the prostate, while standard photo vaporization of the prostate resulted in antegrade ejaculation in not more than 32% of patients [19]. Their results were in accordance with ours.

Similarly, Destefanis et al. concluded that their ejaculatory preserving technique demonstrated superiority over the non-ejaculatory preserving technique. This was evident from the scores obtained from postoperative ejaculatory function questionnaires as well as the rates of antegrade ejaculation observed in their patient group results [15].

Rouf et al. mentioned that sexual satisfaction significantly improved post-surgery in the TURP group, but significantly declined in the HoLEP group. They reported that ejaculation deteriorated significantly in the ejaculatory preserving HoLEP group compared to the TURP group [11].

Trama et al. also reported that at 3 months around 88% of patients maintained their ejaculation, and this percentage increased to 92% and 94% at 6 and 12 months, respectively. They concluded that ejaculatory functions were expected to enhance after longer follow-up periods [18]. These results support our findings regarding improvement in Qmax, reduction in PVRU and preservation of ejaculation following ejaculatory sparing technique for management of LUTS associated with BPO in sexually active patients, where ejaculatory functions would be expected to enhance after longer periods of follow up.

Complications

In terms of complications, in the current study, there were no statistically significant differences in the prevalence of postoperative complications between groups, except for certain variations. The non-ejaculatory preserving group revealed significantly higher occurrence of mild storage symptoms. On the other hand, mild voiding symptoms, moderate storage symptoms and urine retention were significantly higher in the ejaculatory preserving group.

Our findings suggested that majority of our patients had relatively minor postoperative issues that did not require intensive medical management according to Clavien-Dindo Classification, while minor percentage required follow up. This is in accordance with other studies assessing postoperative complications. Researchers in previous studies that utilized diode laser in vaporization of the prostate for managing BPO also mentioned that no severe postoperative complications were reported by their patients [4,17].

Erol et al. reported no intraoperative complications or blood transfusion. They addressed retrograde ejaculation in sexually active patients and irritative symptoms as common complications. They reported symptoms gradually resolved after 2 weeks and were confirmed by measuring Qmax. In accordance with our study, researchers reported that two patients experienced temporary combined urge and stress incontinence which lasted for two weeks post-surgery [16].

Limitations to the study

There were limitations to be acknowledged in this study. Firstly, generalizability of the study findings may be limited due to the potential inclusion of specific patient population that might not represent broader BPH population. The follow-up duration in the current study was relatively short, limiting long-term outcomes assessment. Specifically, a longer follow-up period would have provided a more comprehensive understanding of the impact of the techniques on urinary outcomes.

In this study, we employed a 2:1 ratio of the conventional technique versus the ejaculatory preserving one to reduce the possible risk of postoperative LUTS, though the ejaculatory preserving approach is well established and carries a 20–30% risk of post operative LUTS [20].

Conclusion

Our findings suggest that ejaculatory preserving laser vaporization of the prostate offers potential benefits in BPO management. This technique effectively preserves antegrade ejaculation, semen volume and sexual satisfaction compared to non-ejaculatory preserving technique. However, the non-ejaculatory preserving technique yielded better outcomes in terms of IPSS and urine flow. Both techniques demonstrated significant improvements across all parameters compared to baseline measurements. These findings highlight the potential value of the ejaculatory preserving technique in maintaining sexual function postoperatively while effectively treating BPO. Nevertheless, in order to comprehensively grasp the implications and long-term effects of these results, further research with extended follow-up periods is required. This will provide a more comprehensive understanding of the outcomes and complications associated with these preservation approaches, paving the way for future investigations in this field.

Abbreviation list

ASA	=	American standard association
BOO	=	Bladder outlet obstruction
BPO	=	Benign prostatic obstruction
HoLEP	=	Holmium laser enucleation of the prostate
IPSS	=	International Prostate Symptom Score
KTP	=	Potassium-titanyl phosphate
LUTS	=	Lower urinary tract symptoms
PSA	=	Prostate specific antigen
PVRU	=	Post-void residual urine
SD	=	Standard deviation
Qmax	=	Maximal flow rate
TURP	=	Transurethral resection of the prostate
TUR syndrome	=	Transurethral resection syndrome

Disclosure statement

No potential conflict of interest was reported by the author(s).