A Systematic Review of Thulium Fiber Laser: Applications and Advantages of Laser Technology in the Field of Urology

The safety and efficacy of five surgical treatments in prostate enucleation: a network meta-analysis

PURPOSE

The aim of our study was to investigate the comparative outcomes of five different energy types on surgical efficacy and postoperative recovery in patients with benign prostate hyperplasia.

METHODS

The literature was systematically reviewed on December 1st, 2023, encompassing studies retrieved from PubMed, Embase, Web of Science, and The Cochrane Library databases that incorporated clinical studies of holmium laser enucleation of the prostate (HoLEP), Thulium:YAG laser enucleation of the prostate (ThuLEP), transurethral plasmakinetic enucleation of prostate (PKEP), diode laser enucleation of the prostate (DiLEP) and thulium fiber laser enucleation of the prostate (ThuFLEP) in the treatment of prostatic hyperplasia. Two independent reviewers extracted study data and conducted quality assessments using the Cochrane Collaboration's Risk of Bias tool and Newcastle-Ottawa Scale (NOS). Network meta-analysis (NMA) was employed to indirectly analyze the outcomes of endoscopic enucleation of the prostate (EEP) techniques.

RESULTS

The study included a total of 38 studies, comprising 21 non-randomized controlled trials (nRCTs) and 17 randomized controlled trials (RCTs), incorporating five distinct techniques: holmium laser, Thulium:YAG laser, bipolar plasma, diode laser and thulium fiber laser. In comparing treatment durations, ThuLEP and HoLEP had shorter overall hospital stays than PKEP, while the enucleation time of ThuLEP and HoLEP was shorter than that of ThuFLEP. Moreover, the enucleation tissue weight of both thulium fiber laser and holmium laser was heavier than bipolar plasma. However, the analysis did not reveal any statistically significant variation in complications among the various types of enucleation. In postoperative follow-up, the IPSS at 3 months post-operation was superior in the Thulium:YAG laser group compared to the holmium laser group. The thulium fiber laser technique demonstrated significant advantages over other enucleation methods in terms of QoL and PVR at 12 months after surgery.

CONCLUSION

Theoretical properties may vary among different energy sources; however, there are no discernible clinical differences in operation-related parameters, postoperative complications, and postoperative follow-up. Therefore, the choice of laser does not significantly impact the outcome. However, due to the limited number of included studies, future research should focus on larger sample sizes and multicenter investigations to further validate the findings of this study.

Thulium fiber laser vs. holmium laser enucleation of the prostate: results of a prospective randomized non-inferiority trial

PURPOSE

Holmium laser enucleation of the prostate (HoLEP) represents the current standard procedure for size-independent surgical therapy of benign prostatic obstruction (BPO). With advent of the novel laser technology thulium fiber laser (TFL), we hypothesized that the functional outcome of TFL enucleation of the prostate (ThuFLEP) is non-inferior compared to HoLEP.

METHODS

From October 2021 to October 2022, 150 patients with BPO were recruited for the prospective randomized trial in accordance with CONSORT. Stratified randomization into the arms ThuFLEP (n = 74) or HoLEP (n = 76) was carried out. The primary endpoint was non-inferior international prostate symptom score (IPSS) and quality of life (QoL) at three months after treatment. Secondary endpoints were rates of complications, peak flow, residual urine and operation times.

RESULTS

Preoperative characteristics showed no significant differences. Overall IPSS and QoL improved from 21 to 8 and 4 to 1.5, respectively, after three months of follow-up. No statistically significant differences between ThuFLEP and HoLEP were observed regarding median postoperative IPSS (8.5 vs. 7, p > 0.9), QoL (1 vs. 2, p = 0.6), residual urine (48 vs. 30ml, p = 0.065) and peak flow (19 vs. 17ml/s, p > 0.9). Similarly, safety profile was comparable with no statistically significant differences regarding rate of major complications (5.3 vs. 5.4%, p = 0.5), laser hemostasis time (3 vs. 2min, p = 0.2), use of additive electric coagulation (74 vs. 87%, p = 0.06) or electric coagulation time (8 vs. 8min, p = 0.4).

CONCLUSIONS

In this prospective, randomized trial ThuFLEP showed non-inferior results compared to HoLEP in terms of functional outcomes measured by IPSS and QoL as primary endpoint.

TRIAL REGISTRATION NUMBER

DRKS00032699 (18.09.2023, retrospectively registered).

Thulium Laser for the Treatment of Posterior Urethral Valves in Infants

Objective: Thulium laser (ThL) has become popular in urology, because of its powerful action on tissue, achieving optimal ablation and hemostasis. Aim of our article was to evaluate efficacy of ThL in infants affected by posterior urethral valve (PUV) ablation. Patients and Methods: Clinical charts of 25 infants (age ≤12 months) who underwent PUV ablation were retrospectively reviewed. According to our protocol, all patients performed voiding cystourethrography and cystoscopy 6 to 8 months after initial treatment. Several factors, including age and weight at surgery, operative time, postoperative bleeding, catheterization period, postoperative urinary retention, retreatment for valve remnants, and stricture at follow-up, were evaluated. Preoperative, intraoperative, and postoperative data were analyzed. Results: Mean age at primary surgery was 4.5 months (5 days-10.5 months) and mean weight at primary surgery was 5.7 kg (2.5-10.3 kg). Mean operative time was 29.5 minutes (range 15-50 minutes). None of the patients experienced intraoperative and postoperative bleeding. In all cases, postoperative catheterization period was 1 day. Residual valves were found in 6 of 25 (24%) patients. No cases of urethral stricture were registered during follow-up (48.4 months, range: 11-95). Analyzing literature data using other techniques, complication rate of ThL PUV ablation seems lower than standard treatments (electrofulguration, cold knife) and comparable with those reported with other laser techniques. Conclusion: PUV ablation with ThL has proven to be feasible and safe in infants. Further studies are needed to define the real effectiveness of this laser technology in PUV ablation. Miniaturized instruments and ThL technology make early PUV treatment feasible also in low body weight newborns.

A multicentric non-randomized prospective observational study on the clinical efficiency of thulium fibre laser in large volume stones (> 1000 mm3)

PURPOSE

Our objective was to analyse the clinical efficiency of TFL in large volume stones during retrograde intrarenal surgery.

MATERIALS AND METHODS

Patients with large volume renal stones (> 1000 mm3) operated at two different centres, from May 2020 to April 2021, were enrolled in this study. Retrograde intrarenal surgery was performed using 60W Superpulse thulium fibre laser™ (IPG Photonics, Russia). Demographic data, stone parameters, laser time, and total operating time were recorded, and laser efficacy (J/mm3) and ablation speed (mm3/s) were calculated. NCCT KUB was done at 3 months postoperatively to calculate stone-free rate.

RESULTS

A total of 76 patients were included and analysed in the study. Mean stone volume was 1753.12 ± 1245.81 (1169.27-2193.25) mm3, mean stone density was 1104.46 ± 313.09 (875.00-1317.00) HU, mean laser time was 537.79 ± 689.89 (21.00-1080.00) sec, mean operating time was 43.38 ± 12.96 (35.00-51.25) min, mean laser efficacy was 20.30 ± 15.5 (8.88-25.57) J/mm3, and mean ablation speed was 1.32 ± 0.7 (0.82-1.64) mm3/sec. A strong positive correlation was found between the stone volume and ablation speed (r = 0.659, p = 0.000), and a moderate negative correlation was found between the stone volume and laser efficacy (J/mm3) (r = - 0.392, p = 0.000). With increasing volume of the stone, J/mm3 decreased significantly and ablation speed increased significantly (p < 0.001). Complications occurred in 21.05% (16/76) patients, most of which were Clavien grades 1-2. Overall SFR is 96.05%.

CONCLUSION

Laser efficiency increases at higher stone volumes (> 1000 mm3), as less energy is required to ablate every mm3 of stone.

Upper Tract Tumor En Bloc Enucleation: A Novel Approach to the Diagnosis and Management of Upper Tract Urothelial Carcinoma

OBJECTIVES

To describe and demonstrate our novel en bloc enucleation technique for the endoscopic diagnosis and treatment of upper tract tumors.

METHODS

We detail the instruments required for this procedure, as well as the surgical technique to perform an en bloc enucleation and specimen removal. Endoscopic video of a 2 cm renal pelvis tumor demonstrates all aspects of the technique, and histopathologic slides illustrate the diagnostic information obtained.

RESULTS

A ureteral access sheath is inserted distal to the upper tract tumor, and a flexible ureteroscope is used to visualize the extent of upper tract disease and tumor characteristics. A 200 μm thulium fiber laser partially ablates the tumor surface to create an edge for tissue biopsy and post-ablation urine cytology. The tumor base is identified and the sub epithelial connective tissue is carefully entered with low ablation laser settings. The correct tissue plane is extended by maintaining the ureteroscope in the subepithelial connective tissue and continuing the dissection along the entire width of the tumor base. Once the tumor is enucleated, a Nitinol stone retrieval basket is used to remove the specimen(s) and a ureteral stent is placed.

CONCLUSIONS

En bloc enucleation may provide extensive histopathologic information in upper tract urothelial carcinoma. In cases where complete enucleation is not feasible, this procedure may afford a mechanism for large caliber biopsies.

Thulium: YAG vs continuous-wave thulium fiber laser enucleation of the prostate: do potential advantages of thulium fiber lasers translate into relevant clinical differences?

PURPOSE

To compare endoscopic enucleation of the prostate using a thulium: yttrium-aluminum-garnet (Tm:YAG) laser and a super-pulsed thulium fiber laser set in continuous-wave (CW) mode, and to evaluate whether theoretical advantages of thulium fiber lasers, related to their shorter wavelength, translate into relevant clinical differences.

METHODS

In total, 110 patients suffering from lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia were randomized to undergo either thulium:YAG laser enucleation of the prostate (ThuLEP) or CW thulium fiber laser enucleation of the prostate (CW-ThuFLEP). Intraoperative and postoperative variables and complications were compared. Micturition improvement was assessed at 3-month follow-up using the International Prostate Symptom Score (IPSS), post-void residual urine (PVR) and maximum flow rate (Qmax). Erectile function was evaluated using the International Index of Erectile Function-5 (IIEF-5).

RESULTS

No significant differences between the ThuLEP and CW-ThuFLEP groups were found in terms of operative time (70.69 vs 72.41 min), enucleation time (50.23 vs 53.33 min), enucleated tissue weight (40.2 vs 41.9 g), enucleation efficiency (0.80 vs 0.79 g/min), catheterization time (2.45 vs 2.57 days), hospital stay (2.82 vs 2.95 days) and hemoglobin drop (1.05 vs 1.27 g/dl). At 3-month follow-up, no significant differences were found in IPSS (5.09 vs 5.81), Qmax (26.51 vs 27.13 ml/s), PVR (25.22 vs 23.81 ml) and IIEF-5 (14.01 vs 14.54).

CONCLUSION

ThuLEP and CW-ThuFLEP were equivalent in relieving patients from LUTS and improving micturition. Theoretical advantages of the TFL, such as shallower penetration depth and improved vaporization capacity, did not translate into relevant perioperative outcomes or clinical differences.

Effectiveness and Safety of Thulium Fiber Laser in the Conservative Management of Patients with Upper Tract Urothelial Carcinoma

Background

Few clinical data are available on thulium fiber laser (TFL) and conservative treatment of upper urinary tract urothelial carcinoma (UTUC).

Objective

To assess the effectiveness and safety of TFL in the conservative treatment of UTUC in terms of both tumor ablation and complication rates in a short-term follow-up.

Design setting and participants

Retrospective data were collected from all patients who underwent endoscopic management of UTUC between January 2021 and April 2022. All patients with nonmetastatic UTUC who were deemed suitable candidates (low- and high-grade disease) for conservative treatment were reviewed.

Intervention

All patients underwent ureteroscopy with biopsy and at 2, 6, and 12 mo after the first surgery. UTUC ablation was achieved using TFL.

Outcome measurements and statistical analysis

Clinical data were collected in a dedicated database. Intra- and postoperative outcomes were assessed. A descriptive statistical analysis was performed.

Results and limitations

In total, 28 patients were evaluated. Thirteen patients (46.4%) were included in the low-risk UTUC treatment group and 15 (53.6%) in the high-risk group. The mean tumor size was 15.3 ± 5.7 mm. Biopsy showed low- and high-grade UTUCs in 19 and eight patients, respectively. Only one biopsy was inconclusive for achieving a diagnosis. At the second procedure biopsy, no tumor was found in 19 cases (70.4%), whereas seven had tumors confirmed (25.9%). To date, 23 and 17 out of 26 patients completed the 6- and 12-mo follow-up, respectively. UTUC recurrence was detected in five of 23 patients (21.7%) and in three of 17 patients (17.7%) at 6 and 12 mo, respectively. A total of 95 procedures were performed. No intraoperative complications were observed. In ten of the 95 procedures (10.5%), Clavien-Dindo grade I-II postoperative complications were experienced. Only one grade IIIB postoperative complication was noted.

Conclusions

TFL is a safe and effective technique for conservative treatment of UTUC in a short-term follow-up. Optimal tumor ablation and fine hemostatic control were achieved without major complications.

Patient summary

In this study, we looked at the outcomes of upper urinary tract tumors conservatively treated with the new thulium fiber laser (TFL). We conclude that TFL represents a safe and effective technique for the treatment of this kind of tumors in a short-term follow-up.

A comparison among RIRS and MiniPerc for renal stones between 10 and 20 mm using thulium fiber laser (Fiber Dust): a randomized controlled trial

PURPOSE

We performed a prospective randomized comparison among Retrograde IntraRenal Surgery (RIRS) and MiniPerc (MP) for stones between 10 and 20 mm to evaluate outcomes with the same laser device: Fiber Dust.

METHODS

Patients with a single renal stone between 10 and 20 mm were randomized to RIRS (Group A) versus MP (Group B). Exclusion criteria were age < 18 or > 75, presence of acute infection, coagulation impairments, cardiovascular or pulmonary comorbidities. In both groups, the Fiber Dust laser was used. A CT scan after 3 months was performed. A negative CT scan or asymptomatic patients with stone fragments < 3 mm and a negative urinary culture were the criteria to assess the stone-free status. A statistical analysis was carried out to assess success, complication and retreatment rates and need for auxiliary treatments.

RESULTS

Between January 2021 and January 2022, 186 patients were enrolled (90 in Group A and 96 in Group B). Mean stone size was 15.8 mm and 14.9 mm in Group A and B, respectively (p = 0.23). The overall stone-free rate (SFR) was 73.3% for Group A and 84.4% for Group B. A higher SFR was reached for upper calyceal stones in Group A (90.4%) lower calyceal stones in Group B (91.6%). Retreatment rate (p = 0.31) and auxiliary procedure rate (p = 0.18) were comparable. Complication rate was 5.5% and 5.2% for Groups A and B, respectively.

CONCLUSIONS

RIRS and MP are both effective to obtain a postoperative SFR with Fiber Dust. According to the stone position one treatment is superior to the other one.

Thulium fiber laser enucleation of the prostate (ThuFLEP). Prospective study of mid- and long-term outcomes in 1328 patients

The objective of our study was to estimate the long-term efficacy and safety of thulium fiber laser enucleation of the prostate (ThuFLEP).

MATERIALS AND METHODS

We analysed patients who underwent ThuFLEP due to LUTS related to BPO. Both the pre- and perioperative data as well as the follow-up data for 3 years were evaluated: prostate volume, post-void residual (PVR), Qmax, IPSS and QoL, PSA level and the complication rate. Intraoperative data relating to the weight of resected tissue, the duration of surgery, catheterization and data on hospital stays were also collected. A sub-group analysis was performed to assess whether older patients (>65 years) or those with larger glands (>80 cc) are prone to increased complication risks.

RESULTS

A total of 1328 patients were included in the analysis. The mean age was 66.9±7.5 years. Mean prostate volume was 86.9±41.9 (20-330) cc. All the functional parameters (IPSS, QoL, PVR, Qmax) significantly improved after surgery (p<0.05) and showed durable improvement up to 3-years of follow-up. The frequency of late complications was as follows: stress urinary incontinence - 1.2%; urethral stricture -1.1%; bladder neck contracture - 0.9%. Sub-group analyses revealed increased UTI frequency in older patients (3.5% vs 0.8%, p=0.003) as well as higher rate of SUI (0.4% vs 1.8%, p=0.002) and higher rate of clot retention (11.3% vs 4.4%, p<0.001) in those with larger glands.

CONCLUSIONS

Irrespective of the patient's age and prostate volume, ThuFLEP represents an effective and durable technique of endoscopic enucleation characterized by a low incidence of complications after 3 years of follow-up. In the hands of an experienced surgeon, ThuFLEP can rightly be considered to be a promising alternative to HoLEP for treatment of LUTS associated with BPO.

Percutaneous laser nephrolithotripsy: is it here to stay? Results of a systematic review

PURPOSE OF REVIEW

PCNL (percutaneous nephrolithotomy) and its miniaturized variants are being widely employed in stone surgery, owing to their high-stone-free rates (SFRs) and efficacy for large (>20 mm) stones. With advances in laser technology, it has been readily utilized in PCNL, with the potential for lower complication rates at similar SFR. We aimed to perform a systematic literature review with a focus on recent prospective clinical data that compares laser PCNL to either nonlaser PCNL, different PCNL sizes or other current standards of care such as shockwave lithotripsy (ESWL) or flexible ureteroscopy (FURS).

RECENT FINDINGS

Of the 294 studies initially identified through database searching, nine papers published between 2019 and 2021 were included which compared laser PCNL (Standard PCNL in three, mini-PCNL in four, ultra-mini PCNL in one, micro-PCNL in one study) to other nonlaser lithotripsy, ESWL, FURS, and different PCNL sizes. Complications for laser PCNL ranged from bleeding (4.4%), perirenal haematoma (1.1%), fever (4.6%), ureteric/renal pelvic injury (2.3%), haematuria (2.7%), and infection (2.6%). The mean SFR for laser PCNL was 91.5% at 3 months.

SUMMARY

Percutaneous laser nephrolithotripsy is well tolerated and effective, with high-SFRs at 3 months and relatively low intraoperative and postoperative complication rates. Further research is required to assess the role of intraoperative techniques and suction to improve outcomes further.