Comparative analysis of the safety and efficacy of 1470-nm diode laser enucleation of the prostate and plasmakinetic resection of prostate in the treatment of large volume benign prostatic hyperplasia (>80 ml)

Abstract

Objective

To compare the efficacy and safety of 1470-nm diode laser enucleation of the prostate (DiLEP) with that of plasmakinetic resection of the prostate (PKRP) in treating patients with large benign prostatic hyperplasia (BPH > 80ml).

Methods

The clinical data from 211 cases of BPH (>80 ml) were collected for analysis. The patients were divided into two groups: the PKRP group (n = 118) and the DiLEP group (n = 93), based on the surgical method used.

Result

The DiLEP group demonstrated significantly lower surgical time (p < 0.001), intraoperative bleeding (p < 0.001), bladder flushing time (p = 0.003), indwelling catheter time (p < 0.005), and length of hospital stay (p = 0.018) compared to the PKRP group. However, the quality of the prostatectomy was significantly higher in the DiLEP group (p = 0.005). The Qmax for the DiLEP group was significantly higher than that of the PKRP group (p < 0.05). Compared to the PKRP group, the incidence of urinary incontinence in the DiLEP group increased significantly 4 weeks post-surgery (p = 0.026), although the need for blood transfusion during surgery was significantly reduced (p = 0.037).

Conclusion

Both DiLEP and PKRP are safe and effective methods for treating large-volume BPH. However, DiLEP offers advantages such as more thorough glandular resection, shorter surgical time, reduced bleeding, quicker recovery, and fewer complications.

Keywords:

• Prostate hyperplasia
• 1470-nm semiconductor laser
• PKRP
• complications
• safety

Introduction

Benign prostatic hyperplasia (BPH) is the most prevalent disease causing dysuria in middle-aged and elderly men. The incidence of BPH increases with age, affecting approximately 80% of men over 80 years old [1]. For many years, transurethral resection of the prostate (TURP) has been the gold standard for surgical treatment of BPH. However, TURP carries significant risks, such as bleeding and TURP syndrome [2]. In recent years, high-energy medical lasers like holmium, green, and semiconductor lasers have been increasingly used in BPH surgeries [3–5]. Studies indicate that transurethral holmium laser prostatectomy has superior therapeutic effects compared to traditional prostatectomy [6,7]. However, holmium lasers are pulsed lasers and have inherent drawbacks, such as extended surgical time and less effective hemostasis [6,7]. The 1470-nm diode laser is highly absorbable by both water and oxygenated hemoglobin, offering benefits like reduced intraoperative bleeding, fast cutting and vaporization speeds, and a coagulation layer of less than 1 mm. These characteristics make it highly effective for prostate tissue ablation and hemostasis. When combined with enucleation techniques, this laser shows promising application prospects for treating large prostates exceeding 80 ml [6–8]. Plasmakinetic resection of the prostate (PKRP) is another established surgical method for treating BPH [9–11]. However, for patients with large-volume prostates, PKRP surgery poses concerns regarding surgical time, complications, and the risk of recurrence due to incomplete resection [9–11]. This article collects clinical data from patients with BPH for retrospective analysis, aiming to compare the clinical efficacy and safety of 1470-nm diode laser enucleation of the prostate (DiLEP) with that of PKRP in treating patients with large BPH (>80 ml).

Materials and methods

Inclusion and exclusion criteria

All selected patients were BPH sufferers who underwent surgical treatment at our hospital between November 2016 and May 2022. Prior to surgery, each patient underwent a series of preoperative assessments, including transrectal ultrasound, standard urodynamic testing, digital rectal examination, and serum prostate-specific antigen (PSA) measurements. Inclusion criteria included: (1) presence of surgical indications for BPH and no prior history of BPH surgery [12]; (2) a preoperative rectal ultrasound confirming a prostate volume greater than 80 ml, calculated as (upper and lower diameter) × (left and right diameter) × (front and rear diameter) × 0.546; weight = volume × 1.05; measurements were based on B-ultrasound; (3) a preoperative International Prostate Symptom Scale (IPSS) score greater than 12 and a maximum flow rate (Qmax) less than 10 ml/s; and (4) the ability to complete necessary examinations and self-administer questionnaires for this study. Exclusion criteria included: (1) severe cardio-cerebral vascular disease that made anesthesia during surgery intolerable; (2) coagulation disorders; (3) presence of bladder tumors; (4) urethral stricture; (5) neurogenic bladder and detrusor muscle weakness; (6) bladder infection; (7) nervous system diseases affecting bladder function; (8) prostate cancer; (9) bladder stones; and (10) prostate volume less than 80 ml.

All patients underwent preoperative and postoperative evaluations using the IPSS, Quality of Life Scale (QOL), and maximum urinary flow rate (Qmax). Patients were then categorized into the PKRP group (n = 118) and the DiLEP group (n = 93) based on the surgical method employed. This study received approval from the Ethics Committee of the Chongqing General Hospital (CGH-20161025) and was conducted in line with the Animal Welfare Guidelines and the Helsinki Declaration of 1964, as amended. Informed consent, or its equivalent, was obtained from all participating patients.

Surgical methods

Both groups of patients were operated on by the same physician using lumbar epidural anesthesia. The patients were positioned in lithotomy, and isotonic irrigation solution was used at a pressure of 60 cmH₂O. For PKRP, the surgical method and steps were consistent with our previous reports, employing an electro-resection power of 300 W and electro-coagulation power of 180 W [13]. The PKRP surgical instruments utilized the electrocautery system from Zhuhai’s Simai Technology Co., Ltd. For DiLEP, the surgical method and steps followed existing literature [14,15]. The laser power settings were 120 W for vaporization resection and 40 W for coagulation. The DiLEP surgical instruments employed lasers from Beijing Han’s Tiancheng Semiconductor Technology Co., Ltd. Following both PKRP and DiLEP surgeries, an F20 three-chamber balloon Foley catheter was routinely inserted, and continuous bladder irrigation was performed.

Collection of follow-up and observation indicators

All patients received outpatient follow-up, and data were collected 6 months postoperatively for analysis. Metrics such as postvoid residual urine volume (PVRU), IPSS, Quality of Life Scale (QOL), and Maximum Urinary Flow Rate (Qmax) were assessed both preoperatively and 6 months postoperatively in both groups. Additionally, surgical variables including surgical duration, intraoperative blood loss, bladder irrigation time, indwelling catheter duration, quality of prostate resection, and length of hospital stay were collected and analyzed for each group. Surgical complications were also recorded for analysis. These included death, blood transfusion, rectal injury, bladder injury, capsule perforation, secondary bleeding, urethral stricture, urinary incontinence, bladder spasms, retrograde ejaculation, and erectile dysfunction among others. Sexual dysfunction was specifically evaluated through metrics for retrograde ejaculation and erectile dysfunction. The latter was assessed using the International Index of Erectile Function-5 (IIEF-5). A score below 21 on the IIEF-5 was indicative of erectile dysfunction.

Statistical analysis

Data analysis was conducted using SPSS version 20.0. Prior to any comparative assessments, the normality of the distribution for continuous variables was tested using the Kolmogorov–Smirnov single-sample test. Numerical data that followed a normal distribution were expressed as mean ± standard deviation and analyzed using the T-test. Nonparametric numerical data were represented as median (range) and subjected to the Kruskal–Wallis test for analysis. Categorical data were evaluated using Pearson’s chi-squared test and Fisher’s exact test. A p-value of less than 0.05 was considered to indicate a statistically significant difference.

Result

General clinical data of two groups of patients

As shown in Table 1, no statistically significant differences were observed between the two patient groups in terms of clinical variables such as age, prostate volume, volume of the transitional zone of the prostate, IPSS, QOL, PSA levels, maximum urinary flow rate, and hemoglobin content (p > 0.05). This suggests that the clinical data for both groups were comparable, allowing for a valid comparison of treatment outcomes.

Table 1. Comparison of general clinical data between two groups of patients.

Parameter	DiLEP (N = 118)	PKRP (N = 93)	p value
Age (years)	68.23 ± 5.17	68.45 ± 5.21	0.472
Prostate volume (ml)	101.32 ± 12.07	99.51 ± 13.36	0.141
Prostate transitional zone volume (ml)	62.53 ± 7.24	59.01 ± 9.31	0.211
PSA	1.97 ± 0.61	1.87 ± 0.68	0.552
IPSS	25.34 ± 2.65	24.46 ± 2.82	0.374
QOL	5.15 ± 0.63	5.20 ± 0.45	0.631
ILEF-5	16.52 ± 3.63	17.01 ± 4.21	0.109
PVRU	102.64 ± 35.83	105.23 ± 32.45	0.335
Qmax (ml/s)	8.14 ± 3.97	8.23 ± 3.25	0.205
Hemoglobin (g/l)	125.47 ± 11.55	122.35 ± 13.74	0.405

IPSS: International Prostate Symptom Score; QOL: Quality of Life Scale; ILEF-5: International Erectile Function Index; PVRU: postvoid residual urine volume; Qmax: maximum urine flow rate.

Comparison of surgical conditions between two groups of patients

Table 2 shows that compared to the PKRP group, the DiLEP group had significantly lower operative time (55.62 ± 11.72 vs. 77.38 ± 18.38, p < 0.001), intraoperative blood loss (51.15 ± 15.25 vs. 95.35 ± 19.28, p < 0.001), bladder irrigation time (1.12 ± 0.45 vs. 2.64 ± 0.79, p = 0.003), duration of indwelling catheter use (2.12 ± 0.61 vs. 4.07 ± 1.09, p = 0.005), and length of hospital stay (5.25 ± 0.51 vs. 7.64 ± 0.56, p = 0.018). Conversely, the quality of prostate resection was significantly higher in the PKRP group (52.58 ± 7.75 vs. 38.56 ± 6.57, p = 0.009).

Table 2. Comparison of surgical conditions between two groups of patients.

Parameter	DiLEP (N = 118)	PKRP (N = 93)	p value
Operative time (min)	55.62 ± 11.72	77.38 ± 18.38	<0.001
Intraoperative bleeding volume (ml)	51.15 ± 15.25	95.35 ± 19.28	<0.001
Bladder flushing time (d)	1.12 ± 0.45	2.64 ± 0.79	0.003
Indwelling catheter time (d)	2.12 ± 0.61	4.07 ± 1.09	0.005
Mass of prostate resection (g)	52.58 ± 7.75	38.56 ± 6.57	0.009
Hospitalization time (d)	5.25 ± 0.51	7.64 ± 0.56	0.018

Comparison of preoperative and postoperative related indicators between two groups of patients

Table 3 indicates that both the DiLEP and PKRP groups demonstrated a significant postoperative reduction in IPSS scores, QOL scores, PVRU, and ILEF-5 scores (p > 0.05), along with a significant increase in Qmax (p < 0.05). When compared to the PKRP group, the DiLEP group did not exhibit statistically significant differences in postoperative IPSS scores (6.87 ± 1.59 vs. 7.1 ± 2.4, p > 0.05), QOL scores (1.82 ± 0.42 vs. 1.67 ± 0.61, p > 0.05), PVRU (22.35 ± 10.28 vs. 24.01 ± 8.25, p > 0.05), or ILEF-5 scores (14.03 ± 4.71 vs. 14.21 ± 4.83, p > 0.05). However, Qmax was significantly higher in the DiLEP group than in the PKRP group (18.24 ± 4.83 vs. 14.04 ± 4.01, p < 0.05).

Table 3. Comparison of preoperative and postoperative related indicators between two groups of patients.

Parameter	DiLEP (N = 118)		PKRP (N = 93)
	Preoperative	Postoperative	Preoperative	Postoperative
IPSS	25.34 ± 2.65	6.87 ± 1.59*	24.46 ± 2.82	7.1 ± 2.4*
QOL	5.15 ± 0.63	1.82 ± 0.42*	5.20 ± 0.45	1.67 ± 0.61*
PVRU	102.64 ± 35.83	22.35 ± 10.28*	105.23 ± 32.45	24.01 ± 8.25*
ILEF-5	16.52 ± 5.63	14.03 ± 4.71*	17.01 ± 4.21	14.21 ± 4.83*
Qmax (ml/s)	8.14 ± 3.97	18.24 ± 4.83*	8.23 ± 3.25	14.04 ± 4.01*^,#

IPSS: International Prostate Symptom Score; QOL: Quality of Life Scale; ILEF-5: International Erectile Function Index; PVR: postvoid residual urine volume; Qmax: maximum urine flow rate.

*Compared with preoperative, p < 0.05.

^#Compared with PKRP group, p < 0.05.

Comparative analysis of postoperative complications between two groups of patients

Neither the DiLEP nor the PKRP groups experienced any deaths, rectal injuries, or bladder injuries. Six months post-surgery, there were no statistically significant differences between the DiLEP and PKRP groups in terms of secondary bleeding, urethral stricture, bladder neck contracture, retrograde ejaculation, erectile dysfunction, or urinary incontinence (p > 0.05). However, the DiLEP group showed a significant increase in urinary incontinence at 4 weeks post-surgery when compared to the PKRP group (7.63% vs. 2.4%, p = 0.026). Conversely, the rate of intraoperative blood transfusion was significantly lower in the DiLEP group compared to the PKRP group (1.69% vs. 7.53%, p = 0.037; Table 4).

Table 4. Comparative analysis of postoperative complications between two groups of patients.

Parameter	DiLEP (N = 118)	PKRP(N = 93)	p value
Death	0	0	–
Rectal injury	0	0	–
Bladder injury	0	0	–
Intraoperative blood transfusion	2 (1.69%)	7 (7.53%)	0.037
Secondary bleeding after surgery	2 (1.69%)	3 (3.22%)	0.467
Urethral stricture	2 (2.0%)	2 (2.4%)	0.810
Urinary incontinence (4 weeks after operation)	9 (7.63%)	1 (2.4%)	0.026
Urinary incontinence (6 months after operation)	0	0	–
Bladder neck contracture	3 (2.54%)	4 (4.30)	0.479
Retrograde ejaculation	27 (22.88%)	20 (20.43)	0.812
Erectile dysfunction	17 (14.1%)	11 (11.82%)	0.584

Discussion

BPH is a prevalent condition affecting middle-aged and elderly men, characterized by lower urinary tract symptoms like frequent urination, urgency, dysuria, and incomplete emptying. These symptoms can significantly impact the quality of life [16,17]. Although the etiology of BPH is not fully understood, various theories have been proposed, including the role of androgens and their receptors, the imbalance between cell proliferation and apoptosis, the influence of growth factors and neurotransmitters, the interaction between stromal and glandular epithelial cells in the prostate, and the impact of inflammatory factors [1,18,19]. As BPH progresses, some patients may experience complications such as urinary retention, hematuria, bladder stones, and urinary tract infections. In severe cases, these complications can lead to renal failure [20,21]. Traditional TURP is considered the gold standard for treating BPH. However, the procedure comes with risks like bleeding and TURP syndrome. Additionally, TURP has limitations when treating large volume BPH (>80 ml), particularly given that patients with BPH are often older and may have other comorbidities [22,23]. With advances in medical technology, alternative treatments like green laser, holmium laser, and 1470-nm diode laser have been developed and applied in BPH treatment, often achieving favorable outcomes [23–25].

The 1470-nm diode laser is a near-infrared laser with a dual absorption feature: it is simultaneously absorbed by both hemoglobin and water [25]. This distinctive property distinguishes it from the green laser, which is predominantly absorbed by hemoglobin, and the holmium laser, which is chiefly absorbed by water [25,26]. As a result, the 1470-nm diode laser demonstrates higher tissue vaporization efficiency in comparison to the green laser and exhibits stronger hemostatic capabilities relative to the holmium laser. Owing to its ease of operation, minimal bleeding, and exceptional performance in both tissue vaporization and hemostasis, the 1470-nm diode laser presents significant advantages in the treatment of BPH [25–27].

The application of PKRP reduces the bleeding and the likelihood of TURP syndrome, establishing it as a crucial surgical intervention for BPH [13]. Nevertheless, PKRP has limitations when treating prostates with a volume exceeding 80 ml. These limitations include prolonged operative duration, considerable intraoperative bleeding, residual glandular tissue, and a heightened risk of recurrence [13,28]. On the other hand, DiLEP offers distinct advantages, such as reduced bleeding, enhanced surgical visibility, minimal residual tissue, and a lower rate of recurrence, particularly for larger prostates [14,25–27]. In this study, we observed that, compared to the PKRP cohort, the DiLEP group experienced significantly reduced operative durations, intraoperative bleeding, bladder flushing time, duration of catheterization, and length of hospital stay when treating BPH volumes greater than 80 ml. Moreover, the quality of prostate resection was significantly superior in the DiLEP group [25–27]. These findings imply that DiLEP offers advantages over PKRP, including less bleeding, shorter surgical durations, more effective glandular resections, minimal postoperative bleeding, and accelerated patient recover. In terms of postoperative recovery and effectiveness, we found that in treating 80 ml of BPH, the DiLEP and PKRP groups showed significant reductions in postoperative IPSS scores, QOL scores, PVRU, and ILEF-5 scores (p < 0.05), while Qmax significantly increased (p < 0.05). When compared to the PKRP group, no statistically significant differences were noted in postoperative IPSS, QOL, PVRU, and IIEF-5 scores within the DiLEP group. However, Qmax was notably higher in the DiLEP group. This suggests that both PKRP and DiLEP are effective surgical interventions for BPH with prostate volumes exceeding 80 ml. The elevated Qmax in the DiLEP group may be attributed to the technique’s anatomical enucleation, which likely reduces urethral resistance, thereby resulting in improved urinary flow in patients.

It is well established that complications such as bleeding, urinary incontinence, bladder neck contracture, urethral stricture, retrograde ejaculation, and erectile dysfunction can occur following surgical interventions for BPH [4,21] Previous studies have indicated that the incidence of urethral stricture TURP ranges from 2.2% to 9.8% [4,12]. This rate is relatively higher compared to post-prostatectomy, where it varies from 0.97% to 2.8% [4,12]. Additionally, bladder neck contracture occurs in 0.3–9.2% of cases following TURP surgery [2]. In contrast, bipolar TURP and holmium laser enucleation of the prostate have lower incidences, at 0.5% and 1.2%, respectively [2]. Moreover, the rate of erectile dysfunction post-TURP ranges between 15.42% and 21.67%, while after enucleation procedures, it stands at 8.82% [4,12,30]. The incidence of retrograde ejaculation post-TURP varies widely between 10.28% and 56.67%, but is lower at 6.37% following enucleation procedures [4,12,30]. In the present study, no occurrences of fatalities, rectal injuries, or bladder injuries were observed in both the DiLEP and PKRP groups. Importantly, there were no statistically significant differences between the DiLEP and PKRP cohorts regarding postoperative secondary bleeding, urethral stricture, bladder neck contracture, retrograde ejaculation, and erectile dysfunction (p > 0.05). These findings are consistent with previously reported data [2,4,12,29,30]. Intriguingly, our study identified a significant reduction in the need for intraoperative blood transfusions in the DiLEP group compared to the PKRP group. This suggests that the 1470-nm laser employed in DiLEP procedures offers robust hemostatic advantages, particularly in the treatment of large-volume prostates (>80 ml).

Urinary incontinence is identified as one of the more severe complications following interventions for BPH [2,4,12,29,30]. Existing literature indicates that the postoperative incidence of urinary incontinence after TURP varies between 0.6% and 7.78% [2,4,12,29,30]. Similarly, post-enucleation of the prostate, the incidence ranges from 3.33% to 20% [2,4,12,29,30]. These occurrences are strongly correlated with factors such as age, damage to the sphincter mechanism, dysfunction of the bladder detrusor muscle, and reduced urethral pressure [4,12,29,31].In the present study, we observed that compared with the PKRP group, the DiLEP group significantly increased urinary incontinence 4 weeks after surgery (7.63% vs. 2.4%, p = 0.026). Interestingly, no instances of urinary incontinence were noted in either the DiLEP or PKRP cohorts 6 months post-surgery. The underlying rationale for this short-term rise in incontinence in the DiLEP group might be attributed to the removal of a substantial volume of prostatic tissue during surgery. This results in the formation of a sizable cavity in the prostatic fossa. Although this alleviates urethral pressure, the local connective tissue and smooth muscle structures are temporarily unable to revert to their normal functional states. This mismatch in tissue recovery leads to reduced resistance against internal bladder pressure, culminating in episodes of stress-induced urinary incontinence. However, as tissue repair progresses over time, a new equilibrium between urethral and bladder pressure is established, thereby ameliorating and ultimately resolving the issue of urinary incontinence.

Conclusion

This study establishes that both DiLEP and PKRP are safe and efficacious treatments for BPH exceeding 80 ml. DiLEP presents several advantages including comprehensive glandular resection, reduced surgical duration, minimal bleeding, high safety, and fewer postoperative complications. However, this study is subject to several limitations. Firstly, the research is retrospective in nature, inherently constraining its scope and impact. Secondly, both DiLEP and PKRP possess a specific learning curve, implying that the surgical proficiency and experience of the operator could introduce bias into the research findings. Thirdly, the study’s sample size is relatively small, thus circumscribing the generalizability of the results. Further investigation is warranted, particularly in large-scale, multi-center studies. Fourthly, the follow-up duration is limited to a 6-month period, necessitating additional research to ascertain long-term outcomes and potential complications. Fifthly, the study focuses exclusively on large-volume prostates, thereby requiring further inquiry into the efficacy of DiLEP and PKRP in patients with small-volume prostate hyperplasia.

Author contributions

Conceptualization: Xiao Xiao, Xiao Maolin, and Xiong Tao; Methodology and formal analysis: Deng Xiaohong, Wang Jinzhong, and Tong Wei; validation: Chen Gaoliang and Tang Mengxi; writing and editing: Xiao Xiao and Tang Mengxi; supervision: Xiao Xiao and Tang Mengxi; and funding acquisition: Xiao Xiao and Tang Mengxi.

Acknowledgment

None.

Disclosure statement

The authors declare no competing interests.

Data availability statement

The datasets are available from the corresponding author.

Additional information

Funding

This work was supported by Chongqing Medical Scientific Research Project (Joint project of Chongqing Health Commission and Science and Technology Bureau) [Fund No. 2023MSXM158].