BPH is a common disease in aged men that affects quality of life. In the Baltimore Longitudinal Study of Aging, >60% of men aged ≥60 years have some degree of obstructive symptoms caused by BPH . TURP is regarded as the reference standard in the surgical treatment of BPH . Lately, surgical extirpative techniques using lasers, such as holmium and thulium lasers, have been gaining attention as a treatment option for symptomatic BPH. Since Gilling et al.  first reported on HoLEP in 1996, it has been proven to be one of the most strictly analyzed surgical treatments for the obstructive symptoms of BPH. More than four randomized controlled trials on this modality have been published [14–17]. More recent descriptions of various approaches to en bloc procedures have been published, mainly to address the goals of improving the effectiveness of enucleation, better visualization on the surgical plane, and optimal safety relative to those of the traditional three-lobe method [18–20]. However, the arduous surgical learning curve and potential long operative times of en bloc HoLEP have been obstacles to its extensive use, despite its obvious advantages. Thus, identifying patient groups and tissue characteristics that may increase operative times may help in appropriate patient selection, proper scheduling of the operating room time, and matching the surgeons’ experience level to the expected difficulty.
Generally, en bloc no-touch enucleation involves an “outside-in” procedure that starts at the apex and completely uses a Ho:YAG laser to remove the transitional zone of the prostate. Moreover, the Ho:YAG laser in the vaporization procedure is manipulated as a cutting device. Enucleation time significantly depends on visualization, gland size, and configuration. Enucleated adenoma size is predicted to largely affect enucleation times. Our study found that enucleated specimen weight was related to a marked increase in enucleation time. Several previous studies have reported that the HoLEP operative efficiency increases with larger prostate volumes [21–23]. In our current series, as expected, regardless of enucleated tissue weight or prostate volume on TRUS, the increase in efficiency was shown by a positive slope on the plots of efficiency versus prostate volume.
Giorgio et al.  evaluated the effect of chronic inflammation of the prostate and found that patients with a history of chronic prostatic inflammation have an apparent higher risk of retention. Chronic urinary catheterization and recurrent UTI can hypothetically increase prostate inflammation, which may change the natural morphological architecture, increase gland volume, and obscure the natural plane between the prostate capsule and adenoma. These inflamed prostate tissues may also cause bleeding or oozing during surgery, resulting in poorer visualization and more complicated dissection during en bloc no-touch enucleation. Moreover, alteration in tissue quality and gland volume may also impede morcellation, causing repeated surgeries in this patient group [24, 25]. In our study, history of UTI history was associated with a 24-min increase in enucleation time (Table 3). However, a Foley in-dwelling catheter at the time of HoLEP was not associated with increased time in the surgical steps of enucleation.
Recent studies have assessed the safety of HoLEP in patients who were taking anticoagulants long term and concluded that HoLEP was not a danger to this particular population . This conclusion is expected because the Ho:YAG laser coagulates the bleeding of enucleated tissue with efficiency . We examined whether long-term anticoagulation would influence enucleation time and initially hypothesized that because long-term anticoagulation could increase bleeding and negatively influence visualization of the operative field, it may increase enucleation time. As expected, our study found that history of long-term chronic anticoagulation was related to an apparent increase in enucleation time (Table 3).
The influence of 5ARi use on prostate tissue quality is known to alter the glandular-to-stromal ratio and reduce the volume of overall glandular tissue [27, 28]. For this reason, hypothetically, long-term 5ARi use might increase the prostate fibrous content, which could lead to more difficult enucleation. However, Sandfeldt et al.  found that blood loss volume decreased during TURP after using finasteride for 3 months preoperatively. This might decrease bleeding and positively effect visualization during surgery, leading to a faster enucleation rate. Nevertheless, in our study, we found that history of 5ARi use was not actually related to faster enucleation rate (Table 3). Warner et al.  reported the influence of 5ARi use on HoLEP and found that it did not affect HoLEP operative times or outcomes, which is consistent with our study results. In the current study, we found no clear evidence of a relationship between overall HoLEP surgical time and 5ARi use.
We examined whether presence of “beach ball” and previous TURP would impact enucleation operative time. We assumed that each factor mentioned above might have a potential role in the prostatic tissue histological architecture and natural plane. Interestingly, neither previous TURP nor presence of beach ball during surgery had a notable effect on enucleation efficiency. Identification of factors associated with development of these difficult prostate tissues is worth studying in the future. We speculate that because of anticipated concerns regarding the effect of dense tissue or a complicated plane, greater surgical experience could certainly reduce the effect of prostate tissue on overall operative time.
Among the criticisms of en bloc HoLEP, one perception is that the surgery is difficult to learn and the operation time is longer than those of competitive surgeries, such as TURP. Kim et al.  examined a pooled series and showed that there was no noteworthy inferior difference in the prostate tissue retrieval efficiency between TURP and HoLEP among the published HoLEP series. The average efficiency of tissue retrieval was 0.52 g/min. Shah et al.  described the effect of prostate size on the results of HoLEP in which the mean overall efficiency was 0.48 g/min. In the present study, the overall rate for the whole study group was 0.5 g/min. Compared with those in the above-mentioned earlier randomized clinical trials on the efficiency of retrieval, this value indicated no obvious inferior difference in the prostate tissue retrieval efficiency of the studied cohorts. The reproducibility of the surgical technique was further emphasized.
In the current study, all complications after en bloc no-touch HoLEP were evenly distributed among the groups according to the HoLEP specimen weight. A prospective larger randomized trial of 61 men with prostate sizes of 40–200 g was reported by Tan et al.  in which 30 and 31 patients underwent TURP had HoLEP, respectively. This randomized trial reported that mean Foley in-dwelling time and hospital stay were shorter in HoLEP than in TURP. Outcomes and complication rates were similar in both procedures. The above study supports the statement of Kuntz et al.  that HoLEP voiding improvement and perioperative morbidity are not based on prostate gland size.
This study had some limitations. First, because of its retrospective design, it was intrinsically limited despite inclusion of consecutive patients to avert potential selection bias. Subsequently, we did not consider whether energy usage changed according to the different patient characteristics, but enucleation efficiency may vary depending on the amount of laser energy used. We believe that energy usage diminished as the technique developed. This trend suggests that as the surgeon’s surgical enucleation skill progresses, less energy is used and efficiency is increased. Lastly, surgeries in the study patient group were performed by a single surgeon. Therefore, we recommend that this enucleation time prediction model of en bloc no-touch HoLEP should be examined by multiple surgeons hereafter to determine if it is generally reproducible and acceptable. Despite these limitations, this study examined how preoperative characteristics may affect enucleation times in patients undergoing en bloc no-touch HoLEP for BPH and provided a possible enucleation time prediction model. Additionally, the study also found that prostate gland size was not associated with increases in complications after HoLEP.