Ejaculation-Preserving Versus Conventional Dual Wavelength Diode Laser Vaporization of the Prostate

BACKGROUNDLoss of antegrade ejaculation follows conventional transurethral resection orvaporization of the prostate in the majority of men. Two anatomical regions areconsidered central to this: the internal urethral sphincter at the bladder neck, whichprevents retrograde passage of semen, and the paracollicular and supracollicular tissuearound the verumontanum, which contributes to the emission phase. Techniques preservingone or both regions have been described across several endoscopic platforms, but evidencespecific to the dual‐wavelength diode laser is limited and follow‐up in previous work hasbeen short.OBJECTIVETo determine whether an ejaculation‐preserving technique of dual‐wavelength diode laservaporization of the prostate preserves antegrade ejaculation without compromising reliefof bladder outlet obstruction, and whether any benefit is durable to 12 months.DESIGNProspective, randomized, single‐centre comparative study conducted at the Department ofUrology, Royal Hospital, Sulaymaniyah, Kurdistan Region, Iraq. Allocation followed acomputer‐generated random sequence, with assignments concealed in sequentially numberedopaque sealed envelopes opened after consent. Participants were not informed of theirallocation. The operating surgeon was necessarily aware of allocation.INTERVENTIONAll procedures were performed by a single surgeon under spinal or general anaesthesia,using a 22 Fr continuous‐flow laser cystoscope sheath with normal saline irrigation.Energy was delivered by a Ceralas dual‐wavelength diode laser system (biolitec biomedicaltechnology GmbH, Jena, Germany) emitting simultaneously at 980 nm and 1470 nm, through abare‐tip fibre in continuous‐wave mode at a total power of 140 W. Laser wavelength, fibretype, emission mode and power setting were identical in both arms.Conventional arm: vaporization proceeded from the bladder neck to the verumontanum in thestandard fashion, including tissue at the bladder neck and immediately proximal to theverumontanum, until a wide channel was created.Ejaculation‐preserving arm: no vaporization was performed within 10 mm distal to thebladder neck, and no vaporization was performed within 10 mm proximal to theverumontanum. Between these two margins, the lateral lobes, median lobe and anteriortissue were vaporized to the same endpoint as in the conventional arm. Adherence to bothmargins was recorded prospectively in every case.ASSESSMENTSParticipants were assessed at baseline and at day 7 to 14, 1 month, 3 months, 6 monthsand 12 months. Symptoms were quantified with the International Prostate Symptom Score andits quality‐of‐life item, and erectile function with the five‐item International Index ofErectile Function. Uroflowmetry was accepted only with a voided volume of at least 150mL. Post‐void residual volume and prostate volume were measured by transabdominalultrasound. Ejaculatory status was recorded as a binary patient‐reported outcome:presence or absence of any antegrade ejaculate during sexual activity since the precedingvisit. Complications were graded using the Clavien‐Dindo classification.ANALYSISContinuous variables were compared between arms with the Mann‐Whitney U test and withinarms against baseline with the Wilcoxon signed‐rank test. Proportions were compared withthe two‐sided Fisher exact test, with risk differences reported using Newcombehybrid‐score 95 percent confidence intervals. No imputation was performed. Analysis wasrestricted to participants with complete records at every scheduled visit.NOTE ON REGISTRATIONThis trial was registered retrospectively. The protocol, including the primary endpoint,the secondary endpoints and the two 10 mm technical margins, was submitted to andregistered by the Scientific Committee of the Department of Clinical Sciences, College ofMedicine, University of Sulaimani (number 28, 25 February 2025) and approved by theEthics Committee of the same institution (number 62, 2 March 2025). Public registryregistration was not undertaken before enrolment because the requirement was notappreciated at the time. No outcome measures, eligibility criteria or analysisdefinitions were altered after the study began.