The low power effect on holmium laser enucleation of prostate (HoLEP); A

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ORIGINAL ARTICLE

The low power effect on holmium laser enucleation of prostate (HoLEP); A

comparison between 20 W and 37,5 W energy regarding apical enucleation efﬁcacy and patient safety

L’effet de faible puissance sur l’énucléation de la prostate par laser holmium (HoLEP); Une étude comparative avec 12 mois de suivi

E. Gazel

^a^,∗

, E. Kaya

^b

, S. Yalcın

^b

, T. Tokas

^c

,

H.C. Aybal

^d

, S. Yılmaz

^b

, T.B. Aydogan

^e

, L. Tunc

^f

aAcibademUniversityAnkaraHospital,DepartmentofUrology,Ankara,Turkey

bGulhaneTrainingandResearchHospital,DepartmentofUrology,Ankara,Turkey

cGeneralHospitalHalli.T.,HallinTirol,DepartmentofUrologyandAndrology,Austria

dAnkaraOncologyTrainingandResearchHospital,DepartmentofUrology,Ankara,Turkey

eGoksunStateHospital,DepartmentofUrology,Kahramanmaras,Turkey

fGaziUniversitySchoolofMedicine,DepartmentofUrology,Ankara,Turkey

Received16October2019;accepted12May2020 Availableonline16August2020

KEYWORDS Holmiumlaser;

HoLEP;

BPH;

Low-energy;

Laserenergy

Summary

Introduction.—TheHolmiumlaserhasproventobeaninvaluabletoolforendoscopicprostate enucleation. Theproper energy selection,during thedifferent stepsofthe procedure,has alwaysbeenamatterofdebate.In thisworkwe comparetheeffectivenessoftheHolmium laser,usingtwodifferentlow-powerenergysettings,duringenucleationandhemostasis(20W and37.5W).

Methods.—One hundredandsixty patientsunderwent aHoLEPprocedure witha50Hz and 2J(100W)setting.Duringenuleationandhemostasis,twodifferentlow-powersettingswere applied(20Wvs.37.5W).In bothgroups,onlytheprostatictissueinthebladderneckand enucleatedtissuefarawayfromtheapex,werecutwithasettingof50Hzand2J(100W).

∗Correspondingauthor.

E-mailaddress:eymen[email protected](E.Gazel).

https://doi.org/10.1016/j.purol.2020.05.009

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Results.—Themeanenucleationefﬁciency(0.78vs.1.2g/min-p:001)wassigniﬁcantlyhigher by utilizing 37.5W energy (group 2). Additionally, the mean enucleation rate (0.64 vs.

0.88%—P:0.001)andlaserefficiency(2.07vs.2.12joule/g—P:0.003)weresignificantlyhigher ingroup2.Theenucleationtimewassignificantlyshorter(54vs.75.5mins—P:0.002),whilethe meancatheterremovaltime(27vs.42hrs—P:0.008)andHbdecrease(0.5vs.0.6g/dl-—P:0.019) weresignificantlyloweringroup2.

Conclusions.—HoLEPcanbeperformedefﬁcientlywith100W—37.5Wsettings.Enucleationand hemostasiscanbeperformedsuccessfullywith37.5W,whiletheuseof100Wduringbladder neckdissectionshortensthedurationoftheprocedure.

Levelofevidence.—3.

MOTSCLÉS Laseràholmium; HoLEP;

HBP;

Batteriefaible; Énergielaser

Résumé

Introduction.—LelaserHolmiums’estrévéléunoutilprécieuxpourl’énucléationendoscopique de laprostate. La sélection appropriéede l’énergie,aucours desdifférentes étapesde la procédure,atoujoursfaitl’objetdedébats.Danscetravail,nouscomparonsl’efﬁcacitédu laserHolmiumenutilisantdeuxparamètresd’énergiedefaiblepuissancedifférents,lorsde l’énucléationetdel’hémostase(20Wet37,5W).LesméthodeCentsoixantepatientsontsubi uneprocédureHoLEPavecunréglagede50Hzet2J(100W).Surtoutpourladissectionapicale etl’hémostase,deux réglagesdifférentsdefaiblepuissanceontétéappliqués(20Wcontre 37,5W).

Résultats.—L’efficacitédel’énucléationmoyenne(0,78vs1,2g/min-p:001)étaitsignificative- mentplusélevéeenutilisantuneénergiede37,5W(groupe2).Deplus,letauxd’énucléation moyen(0,64vs0,88%—p:0,001)etl’efficacitédulaser(2,07vs2,12joule/gp:0,003)étaientsig- nificativementplusélevésdanslegroupe2.Letempsd’énucléationétaitnettementpluscourt (54vs75,5min—p:0,002),alorsqueletempsmoyenderetraitducathéter(27vs42heures—p:

0,008)etladiminutiondel’Hb(0,5vs0,6g/dl—p:0,019)étaientsigniﬁcativementplusfaibles danslegroupe2.

Conclusions.—HoLEP peutêtreexécuté efﬁcacementavecdes réglagesde 100Wà37,5W.

L’énucléation et l’hémostase peuvent être réalisées avec succès avec 37,5W, tandis que l’utilisationde100Wlorsdeladissectionducoldelavessieraccourcitladuréedelaprocédure.

Niveaudepreuve.— 3.

Introduction

In the last two decades, a plethora of innovative transurethral procedures challenged the supremacy of the two, formerly standard, surgical options (monopolar transurethral resection of the prostate (TUR-P) and open prostatectomy[1].Todate,laserenucleationoftheprostate has abrogated the indications of the open technique for large prostate glands. Holmium Laser Enucleation of the Prostate (HoLEP) has been established as a distinguished methodbetween the differentsurgical treatment modali- ties,can beappliedtoallprostate sizes [2—5]andshows similareffectivitywiththeThuliumlaser[6—8].whencom- pared to TUR-P, the HoLEP provides better hemostasis, shortercatheterizationandhospitalizationtimes,andnul- liﬁestheratesoftheTURPsyndrome[4,9].

The Holmium laser system allows the prostatic tissue to be enucleated from the capsule while pro- viding simultaneous coagulation [10]. Depending on

technologicaldevelopments,lasertechnologyhasalsomade progress.Nonetheless,despiteevolutionofinstrumentation and surgical technique, stress urinary incontinence (SUI) remains a great challenge. The new Holmium YAG laser device, with 120W laser energy, contains a dual foot pedal.Thisfeatureallowsthesurgeontousetwodifferent settings.Thelowpower energyisusedforhemostasisand dissection of the prostatic apex, while the high-power energy is used for enucleation [11]. Various results have been reported in the international literature, by using differentlaser energysettings [11—13].The initial instal- lations of the Lumenis laser device are usually set at 50Hz-2J(100W)and20Hz-1J (20W).Inthiswork,we used low-power energy settings during the whole procedure, exceptnear the bladderneck, where high-power settings canbeusedtofacilitateenucleation.Theaimofthisstudy istocomparetheeffectivenessandsafetyoftheHolmium laser, using two different low-energy settings, during enucleationandhemostasis (20W and37.5W) in orderto

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set a slightly higher energy threshold (37.5W) in order to increase enucleation efﬁciency and not compromising patientsafety,mainlynotincreasingSUIrates.

Materials and methods

Thestudy wasdesignedretrospectivelyand wasapproved by the Scientiﬁc ResearchEthics Committee of Gazi Uni- versity(protocol no.2017-297).Datawerecollected from 160patientswhounderwentaHoLEPprocedureforBenign Prostate Hyperplasia (BPH), between June 2015 and July 2017. Written informedconsents were collected from all participants. The patients were divided into two groups, basedontheHolmiumlaser120-Wholmium:YAG(yttrium aluminumgarnet)energysettings.InGroup1(20W),enucle- ationandhemostasiswereperformed inasetting of20Hz and 1J. In Group 2 (37.5W) the settings were 25Hz and 1.5J.Inbothgroups,theprostatetissueinthebladderneck andtheenucleatedtissuefarawayfromtheapex,assub- jectivelyjudged by the surgeon, were cut with a setting of 50Hz and 2J (100W). Pulseduration was long for low energysetting as hemostasismode and shortpulse dura- tionwasusedforhighenergysettingasenucleationmode.

Allprocedureswereperformedbyasingleexpertsurgeon.

All patients underwent a 3-lobe technique as previously described [14].The main clinical endpoint of our work is theenucleationefﬁcacyparameters(translatedinincrease ofQmaxandQave)ofthedifferentlasersettings,withsec- ondary endpoints being the postoperative outcomes, QoL andcomplicationrates. Theinclusioncriteriawereasfol- lows:inadequateresponsetomedicaltherapy,peakurinary ﬂowrate(Qmax)of<15mL/s,grosshematuriaduetoBPH, recurrent urinary tract infection, postvoid residual (PVR) volume of >150mL, or acute urinary retention. Patients withneurogenicbladder,prostatecancer,diabetesmellitus, anticoagulationtherapy,bladdercancer,urethralstricture, andprevious prostatesurgeries, largerprostates (>120cc) aswellascaseswithmissingdatawereexcluded.

Patient characteristics included age, prostate-specific antigen(PSA)andprostate size.The prostate volumewas evaluatedby transrectalultrasonography. Improvementof symptoms were evaluated by uroflowmetry parameters andsymptomscores.Internationalprostatesymptomscore (IPSS), quality of life (QoL), maximum flow rate (Qmax), average urinary flow rate (Qave), post voiding residual volume(PVR),voidingtime(VT),timetomaximumofvoiding(MVT) wererecorded pre-andpostoperatively(at the time of discharge and at one, 3, and 12 months). Enu- cleation rates (ERs) were calculated by the ratio of the amount of tissue removed to the transitional zone size.

Additionalinformation,likeenucleationtime(ET),morcellation time (MT), total operation time (TOT), total laser energy(TLE),efficiencyoflaser(EL-joule/gram),efficiency of enucleation (EE-gram/min), decrease in hemoglobin, enucleated tissue weight (ETW), complication rate (CR), hospitalization time (HT), catheterization removal time (CRT) was recorded. Intraoperative, perioperative and late complications (in 3th and 12th months) were also recorded. For continence status, patients filled Interna- tional Consultation on Incontinence Questionnaire short form.

Equipment

Allprocedureswereperformedusinga120-Wholmium:YAG (yttriumaluminumgarnet)laser(Versapulse,LumenisInc., SantaClara,CA,USA),anda550-nmend-firingfiber(Slim- LineTM 550, Lumenis Inc.). The energy settings for each pedalwereenteredseparatelytothemaincomputerprior tosurgery.Acontinuous-flow26Fresectoscope(KarlStorz, Tubingen,Germany),arigidnephroscopewitha5-mmwork- ingchannel(KarlStorz),andaVersacuttissuemorcellator (LumenisInc.)werealsoutilized.Thepowersettingswere, for the right pedal, 20 Watt (1J energy,20Hz frequency) inGroup1,and37.5Watt(1.5Jenergy,25Hzfrequency)in Group2.Inbothgroups,powersettingsweresetat100Watt (2J energy, 50Hz frequency,andshort-500␮s pulsewidth combination)intheleftpedal.

Statistical analysis

The Statistical Package for Social Sciences 20.0 soft- ware (SPSS 20.0, Chicago, IL, USA) was utilized. The Kolmogorov-Smirnov,Kurtosis,andSkewnessTestswereused to assess the normality of the data. Descriptive statis- ticsof nominalsampleswereexpressedwithnumbersand percentiles. Descriptive statistics of scale samples were expressed as mean±standard deviation. The continuous variableswerecomparedusingindependentsamplest-test orMann—Whitney U-test.Categorical datawerecompared usingtheChi²orFisher’sExacttest.Spearmancorrelation coefﬁcient wasused to explore the relationship between thecontinuousvariables includingtheenergysettingsand the EE,ER, ET,TLEandEL. P<0.05 value wasconsidered statisticallysigniﬁcant.

Results

Twogroupsof80patientseachweredemonstrated(Table1).

Theirmeanagewas63±7.97yearsingroup1and62±7.07 years in group 2. There was no significant difference between most characteristics of the two groups, including PSA, prostate volume, IPSS scores, and uroflowmetry parameters.Nevertheless, PVRwaslowerin Group1 (102 vs.173ml—P:0.01).Inbothgroups,postoperativeIPSS,QoL, PVR, MVT,andVTsignificantly decreased whileQmax and Qavesignificantlyincreasedpostoperativelyincomparison to their preoperative status (Table 2). This improvement couldberecordedinallfollowupperiods(discharge,1st, 3rdand12thmonth).Nonetheless,bycomparingthediffer- entgroups,QoLwassignificantlybetterinthe2nd(37.5W) group(p:0.015),beginningdirectpostoperatively.Addition- ally, IPSS was also significantly better in the 2nd group, beginning1monthpostoperatively(p:0.001)

BycomparingthemeanCRT(27vs.42hrs—P:0.008)and Hb decrease (0.5 vs. 0.6g/dl—P:0.019) a statistically sig- niﬁcant differenceinfavor of group2 couldberecorded.

Therewerenosignificantdifferencesregardinghospitaliza- tion time(Table 3).The mean EE wassignificantly higher (P:0.001) in group 2 (1.2g/min) compared with group 1 (0.78g/min).ThemeanERandELweresignificantlyhigher (P:0.001 andP:0.003)in group2(0.88% and2.12joule/g) thaningroup1 (0.64%and2.07joule/g).Additionally, the

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Table1 Patients’baselinecharacteristicsandpreoperativedata.

Variable Group1(N:80) Group2(N:80) P-Value

Patientage(year) 63±7.97 62±7.07 0.28

PSA(ng/mL) 3.22±5.02 1.27±0.17 0.84

Hblevel(g/dL)^a 14.65±1.04 14.25±0.21 0.12

ProstateVolume(mL) 79±35.71 68.5±47.37 0.32

IPSS 25.68±5.77 21.08±5.27 0.33

QoL 4±1.09 44±0.57 0.81

Qmax(ml/s)^a 10.39±4.21 9.05±5.71 0.07

Qave(ml/s) 4.4±1.86 3.2±2.38 0.08

PVR(ml) 105±51.12 154±124.3 0.001

VT(sec) 128±77.15 82.65±55.16 0.63

MVT(sec) 72±35.16 11.5±10.95 1

N:numberofpatients;PSA:ProstateSpecificAntigen;Hb:Hemoglobin;IPSS:InternationalProstateSymptomScore;OoL:Qualityof Life;Qmax:Maximumflowrate;Qave:Averageurinaryflowrate;PVR:PostVoidingResidualVolume;VT:voidingtime;MVT:Timeto maximumofvoidingSec:second

a StatisticallyanalyzedwithIndependentSamplest-test;OthersanalyzedwithMann—WhitneyUtest.

Table2 Baselineandfollowupdatas.

Parameters Mean±SD

IPSS QoL Qmax(ml/s) Qave(ml/s) PVR(ml) VT(sec) MVT(sec)

Preoperative

Group1 25.68±5.77a 4±1.09 10.39±4.21^a 4.4±1.86 105±51.12 128±77.15 72±35.16 Group2 21.08±5.27a 4±0.57 9.05±5.71^a 3.2±2.38 154±124.3 82.65±55.16 11.5±10.95

P-value 0.33 0.81 0.07 0.08 0.001 0.63 1

Discharge

Group1 15±3.52^b 4±0.99^b 13±4.81^b 9±3.32^b 35±22.59^b 35.1±29.96^b 28±14.32^b Group2 14±3.4^b 4±0.92^b 14±9.08^b 10±5.72^b 32±27.54^b 44±30.35^b 24±18.71^b

P-value 0.08 0.015 0.65 0.15 0.23 0.65 0.39

1thmonth

Group1 12.5±2.77^b 2±0.58^b 20±7.11^b 14±5.09^b 27±17.04^b 32±23.49^b 25±13.17^b Group2 11±2,59^b 2±0.6^b 22.5±11.99^b 16±7.76^b 24±23.48^b 44±30.35^b 22±19.81^b

P-value 0.001 0.04 0.25 0.26 0.09 0.19 0.37

3thmonth

Group1 3±0.86^b 1±0.55^b 27.09±7.28^a,b 10.85±4.57^b 24±23.38^b 28.5±9.62^b 10.3±4.03^b Group2 1±0,99^b 1±0.48^b 28.09±7.22^a,b 13.6±4.18^b 12±11.02^b 30±18.63^b 8±4.88^b

P-value 0.001 0.03 0.46 0.02 0.34 0.4 0.79

12thmonth

Group1 3±0.67^b 1±0.5^b 27±7.25^b 17±4.88^b 22±21.05^b 25±8.62^b 11±4.1^b Group2 1±0,96^b 1±0.44^b 28±6.65^b 17±5.6^b 20±19.02^b 25±14.77^b 9±5.19^b

P-value 0.001 0.06 0.74 0.18 0.29 0.65 0.96

N:numberofpatients;IPSS:InternationalProstateSymptom Score;OoL:QualityofLife;Qmax:Maximumﬂowrate;Qave:Average urinaryﬂowrate;PVR:PostVoidingResidualVolume;VT:Voidingtime;MVT:Timetomaximumofvoiding;Sec:Second.

a StatisticallyanalyzedwithPairedSamplest-test;OthersanalyzedwithWilcoxontest.

b P<0.01comparedtobaseline.

Table3 Patients’comparisonofpostoperativeoutcomes.

Group1(N:80) Group2(N:80) P-value

Hbdecrease(g/dl)Catheterizationremoval 0.6±0.39 0.5±0.1 0.019

Time(hour) 42±27.74 27±14.38 0.008

Hospitalizationtime(hour) 28±6.06 33±8.03 0.16

*StatisticallyanalyzedwithMann—WhitneyU—test.N:numberofpatients.

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Figure1. Correlationsoftheenucleationparameters,totallaserenergyandefﬁciencyoflaserbetweengroups.

Table4 Comparisonofperioperativeoutcomesbetweengroups.

Group1(N:80) Group2(N:80) P-Value

Enuclatedtissueweight(g)^a 54,16±43,56 58,3±57,33 0,49

Efﬁciencyofenucleation(g/min) 0.78±0.35 1.2±0.56 0.032

Enucleationrate(%) 0.64±0.27 0.88±0.5 0.001

Enucleationtime(min) 75.5±35 54±29.73 0.002

Morcelationtime(min) 8±5.68 7.5±6.88 0,07

Totaloperationtime(min 78±38.17 66±35.15 0.09

Totallaserenergy(joule) 57.12±47.14 74.2±44.88 0.004

Efﬁciencyoflaser(joule/g) 1.78±0.62 2.23±1.28 0.003

N:numberofpatients;g:gram;min:minute.

aStatisticallyanalyzedwithIndependentSamplest-test;OthersanalyzedwithMann—WhitneyU-test.

meanof ER,TLE, EL,EE and ETwere significantlydiffer- entwithPearsoncorrelationtest(P:0.001)(Fig.1).Inthe spearman analysis, two groups positively correlated with EE (rho=0.248, P=0.04), ER (rho=0.394, P=0.001), TLE (rho=0.235,P=0.004), LE(rho=0.251, P=0.002),Nocor- relationswereidentifiedbetweenthelaserenergysettings andET.Finally,theETwasshorterinGroup2thaninGroup 1(54vs.75.5mins—P:0.002).IntermsofETW,MT,TOT,TLE, therewerenosignificantdifferences(Table4).Finally,there wasnosignificantdifferencebetweenthegroupsaccording totheClavien-DindoComplicationClassification(Table5).

Discussion

Sincethe ﬁrst pioneeringstudies [15,16], the HoLEPpro- cedurehasevolvedalongside otheradvances inurological technology[2—5].Mostexistingstudiesrecommendahigh laserenergy(>80W) duringthe wholeprocedure, applied by utilizinga single pedal [12,17,18]. However,although, inthatway,a fastenucleationcanbeachieved,irritative symptoms frequently remain, also after 12 months [17].

The first work about the safety and efficacy of a 50W holmiumlaser waspresented byRassweiller et alin 2008 [19].Theauthorsrecruitedtwogroupsofpatientstreated atpowersettingsof25Wand40W,andrecordedcompara- bleenucleationefficiencywithourcohort.However,their transfusionratewasrelativelyhigh,reaching8%.Following studiesprovedthefeasibilityof thelowenergypowerset (30—40W), presenting excellent enucleation and minimal

complication rates [12,13]. Our preoperative, postopera- tiveresults,andcomplicationratesarecomparablewiththe aforementionedstudies.

OnerecentimprovementininHoLEPsurgeryistheuse ofa120Wlaser(LumenisPulse;LumenisLtd)[14].Itallows theusertochangebetweentwodifferentsetupsbyutilizing adualpedalwithouttheneedforamanualchangeover[2].

The lowenergysettingis usuallypreferredforhemostasis anddissectingneartheapexoftheprostate,whilethehigh energy setting is used for enucleation [2]. In this patient cohort,thehighenergysettingwasappliedtocutthepro- static tissue at the bladder neck level. The rest of the enucleation,aswellasthehemostasis,wereprocessedby usingthelowenergysettings.Inthisway,wecouldachieve comparableenucleationefﬁciencyandproceduretimeswith thealready publishedones[13,20], andat thesametime preserve optimal hemostasis and minimize complications, including irritative symptoms and stress urinary incontinence (SUI). By slightly increasing energy to 37.5W, we couldachieveimprovedenucleationefﬁciencynotcompro- mizing patient safety. Gong and colleagues [21] used an energyof30Wfortheapicalincisionandpresentedamean IPSS score decreasefrom21.9 to4.3, threemonths after the procedures. At the same time, their Qmax increased from 4.7ml/sec to 23.4ml/sec and their PVR dropped from 146.3ml to28.1ml.Their mean operative timewas 54.7minutesandmeanenucleationtime36.5minutes.Our studydemonstratescomparableoutcomesandgoesonestep furtherregardingapicaldissectionenergy,bycomparingtwo differentlow-powerenucleationsettings(20Wvs.37.5W).

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Table5 Detailedanalysisofcomplications.

Intraoperativeandperioperativecomplications Group1n(%) Group2n(%) P-value

Bleeding 0 0

Bladdermucosalinjury 1(1.25) 1(1.25) 1

Capsularperforation 1 1 1

ConversiontoTUR-P 0 0

Transfusion 0 0

TURsyndrome 0 0

Recatheterisation 3(3.7) 2(2.5) 0.97

Clotretention 2(2.5) 1(1.25) 0.99

Secondaryhaemorrhage 0 0

Urosepsis 0 0

Urinarytractinfection 2(2.5) 3(3.7) 0.97

Fever 2(2.5) 3(3.7) 0.97

Latepostoperativecomplications(3th/12thmo)

StressUrinaryIncontinence 3(3.7)/1(1.2) 2(2.5)/0 0.97/0.95

Bladderneckcontracture 3(3.7)/2(2.5) 4(5)/2(2.5) 0.97/1

Urethralstricture 4(5)/0 4(5)/1(1.2) 1/0.95

Meatalstenosis 3(3.7)/0 4(5)/0 0.07/1

Reoperationforresidualadenoma 0/0 0/0 1

Themajorityofourpatientshadaprostatevolumerangeof 60—80mL,anIPSSscorerangeof22—25,aQmaxrangeof 8.47—10.1mL/s,andaPVRrangeof102—173mL.Ourresults emphasize thatbetterhemostasiscanbeaccomplishedat frequenciesabove20Hz.

In both groups, voiding parameters including Qmax, Qave, IPSS, QoL, VT, MVT significantly improved starting directpostoperatively.Therewasasignificantdifferencein favor of the 2nd group when assessing postoperativeQoL andIPSS.Furthermore,decreaseinhemoglobinwaslower, andCRTwasshorteringroup2.Ourpostoperativeoutcomes appeartobe better thanthe results of astudy using the 100W holmium laser [22].Anothercohort of 231patients demonstrated similar results withour group, in terms of IPSS, Qmax, PVR, HT and CRT [23]. Stern el al reported HoLEP procedures utilizing a 120W laser platform. Their lasersettingswere80Wforenucleationand45Wforapex dissection and hemostasis.The authors reported a higher decreaseofHbcomparedwithourstudy.Ontheotherhand, EEwas0,84gperminutewhichis slightlylower(1,2gper minute)thantheonepresentedbyourgroup[11].Accord- ingtoourresults,theuseof37Wsettingseemstoprovide alowerhemoglobindecreaseandashorterremovalofthe urethralcatheter.Accordingtoenucleationparameters,the resultsofGroup2werebetterthanGroup1.AlthoughETW was similar between the groups, EE, ER, ET were higher inGroup 2.Thus,enucleationandhemostasiscan beper- formed moreeffectively andrapidlyby applyingthe1.5J and25Hzenergysettings.TLEandELweremoreefficientin Group2.Wereporthigherenucleationandlaserefficiency, aswellasincreasedenucleationrateswhenusingthe37.5W, comparedtothe20Wsetting.

In comparison with already published works, a lower perioperativeandpostoperativecomplicationratecouldbe reported.Notransfusionswerenecessaryfor bothgroups.

Oneof thechallenging complicationsof theHoLEPproce- dureisthepostoperativestressurinaryincontinence(SIU),

ranging 2—15% and being, however, often a temporary condition[24—26]. This situationis basedontwofactors;

excessiveurethralsphinctertractionduringtheprocedure andtissuedamagecausedbylaserenergyneartheapexof theprostate.Thelowenergyusefortheadenomanearthe urethralsphinctercanreducelikelihoodSIU.Ourpostoper- ativeSIUratesweresimilarinboth20Wand37.5Wenergy settings and compatible with the international literature (3.7% and 2.5%). Additionally, bladder neck contracture, urethralstrictureandmeatalstenosisrateswerealsosimilar betweenthetwogroups.

Our study is not without limitations, namely its retro- spectivecharacterandthelackofacontrolgroup.Moreover largerprostates(>120cc)werenotincluded.Anadditional confoundercouldbethesubjectiveswitchtothehigh-power settingwhenenucleatingawayfromtheapex.However,our resultspresentedstrongevidenceregardingaHoLEPdual- energymodethat providesefﬁcientandfastenucleation, and,at thesametime,optimalhemostasisandsigniﬁcant improvementofsymptomsrelatedtoprostatichyperplasia.

Conclusion

Thenew120HHolmiumlasercanbeusedefﬁcientlyutiliz- ingthe100W-37.5Wsettings.Withtheuseof37.5W,both enucleationandhemostasiscanbeperformedsuccessfully, whiletheuseof100Winthebladderneckshortensthedura- tionof theprocedure.The useoflaser energywith>35W mayberecommendedinHoLEPprocedure.

Funding

Nofundingwasreceivedforthisstudy.

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Disclosure of interest

Allproceduresperformedinstudiesinvolvinghumanparti- cipantswereinaccordancewiththeethicalstandardsofthe institutionaland/ornationalresearchcommitteeandwith theHelsinkideclarationandcomparableethicalstandards.

Theauthorsdeclarethattheyhavenocompetinginter- est.

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