Predictive Value of Enucleation Ratio for Symptomatic Improvement After HoLEP: A Multicenter Prospective Cohort Study

HoLEP has become a widespread and well-practiced surgical method for benign prostate obstruction (BPO). The method is known to have a steep learning curve, and mastery requires extensive practice. Treatment efficiency depends on removing the obstruction while protecting the delicate external urethral sphincter.

However, it's still unclear which pre-operative and intra-operative factors affect surgical outcome. Some authors have already contributed to this subject; in fact, changes in peak urinary flow rate, IPSS-QoL, and the absence of stress urinary incontinence and high-grade complications are among the agreed-upon criteria for successful surgery. As the main purpose of HoLEP, or any other benign prostate surgeries, is to remove obstruction, the more adenoma tissue to be removed, the less obstruction there will be. Yet not anatomic, but there's a surgical capsule around the prostate, which can stretch, causing residual tissue to obstruct the urethral passage. Leaving residual adenoma tissue is not uncommon and may affect the efficacy of HoLEP, particularly given the steep learning curve of the procedure. Therefore, it may be reasonable for one to consider that the higher the ratio of adenoma tissue removed, the better the outcomes could be.

Enucleation ratio is a novel parameter that has not been investigated previously in this context and is calculated by dividing the weight (grams) of morcellated adenoma tissue by the preoperatively measured prostate volume (mL). The density of the prostate is widely accepted as 1 gram per milliliter, so the enucleation ratio has no units.

Identifying a minimum enucleation ratio associated with clinically meaningful symptomatic improvement could provide surgeons with a measurable intraoperative target, potentially improving procedural standardization and patient counseling - particularly during the learning curve of HoLEP.