Assessing spatial perception of learners during holmium laser enucleation of the prostate (HoLEP)
Nabila Reem Khondakar1
, Amir Patel1, Jenny Guo1, Matt Pearson2, Shaan Setia2, Amy E. Krambeck1, Perry Xu1
Contributions: (I) Conception and design: P Xu, AE Krambeck; (II) Administrative support: P Xu, NR Khondakar, AE Krambeck; (III) Provision of study materials or patients: P Xu, AE Krambeck, J Guo, A Patel; (IV) Collection and assembly of data: P Xu, NR Khondakar, M Pearson, S Setia; (V) Data analysis and interpretation: P Xu, NR Khondakar; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors.
Background: Holmium laser enucleation of the prostate (HoLEP) has a steep learning curve. Specific educational efforts to improve HoLEP training has not been extensively studied. The aim of this study was to assess the spatial perception of urology residents (learners) HoLEP videos to improve future educational efforts.
Methods: A cross-sectional simulation-based observational study during an academic urology conference was performed. A HoLEP recording was shown to resident physicians and paused at 5 time points. Resident physicians were then asked to mark down coordinates on diagrams of prostates in the coronal, axial and sagittal dimensions at each pause to denote where they perceived the laser was pointing.
Results: Twenty-one urology residents (learners) participated in the study, of whom, 47.6% had prior HoLEP exposure. The learners plotted perceived coordinates at pre-designated time points in 3 dimensions throughout a HoLEP, totaling 315 coordinates. Learners perceived more accurately in the coronal dimension and were most accurate in identifying the verumontanum (the first time point of the procedure). Those with prior HoLEP exposure, as well as senior residents, were significantly more likely to accurately pinpoint the verumontanum in the coronal dimension (P=0.04, 0.03 respectively). Prior HoLEP exposure and post-graduate year (PGY)-level was not associated with accurately identifying the other time points in all dimensions.
Conclusions: Spatial understanding during a HoLEP is challenging and learners are inaccurate in pinpointing coordinates while watching endoscopic recordings alone, regardless of PGY-level and prior HoLEP exposure. Learners appear to perceive in the coronal dimension more accurately as opposed to the axial or sagittal dimensions. This could be used to direct future educational efforts for teaching HoLEP.
Keywords: Holmium laser enucleation of the prostate (HoLEP); benign prostatic hyperplasia (BPH); transurethral resection of the prostate (TURP); simulation
Submitted May 08, 2026. Accepted for publication Jul 14, 2026. Published online Aug 28, 2026.
doi: 10.21037/tau-2026-0443
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Key findings
• This simulation study found that urology residents have variable spatial perception when watching holmium laser enucleation of the prostate (HoLEP). Accuracy was highest in the coronal dimension and at the verumontanum. Prior HoLEP exposure and senior training level improved identification of the verumontanum, but did not improve accuracy at later operative time points or in axial and sagittal views.
What is known and what is new?
• HoLEP is effective for benign prostatic hyperplasia (BPH) but has a steep learning curve, partly due to limited training exposure and the need to understand distorted three-dimensional anatomy through a two-dimensional endoscopic view.
• This study suggests that residents may recognize familiar landmarks but struggle to maintain spatial orientation as HoLEP planes are developed and distorted, especially in axial and sagittal dimensions.
What is the implication, and what should change now?
• HoLEP education should emphasize deliberate spatial mapping, annotated videos, simulation, and real-time teaching focused on depth perception, sagittal orientation, and recognition of evolving surgical planes.
Introduction
Background
Holmium laser enucleation of the prostate (HoLEP) for the surgical treatment of benign prostatic hyperplasia (BPH) has emerged over the past two decades as an important surgical alternative to transurethral resection of the prostate (TURP). Compared to TURP, HoLEP has shorter hospital length of stays, lower blood loss, and is more economically favorable (1,2). Offering HoLEP in one’s clinical practice draws more patients and increases surgical volume (3).
Rationale and knowledge gap
Despite the many benefits of HoLEP, access to HoLEP during surgical training is limited compared to TURP. As of 2021, it was estimated that less than one-third of residents have access to HoLEP cases, and only six out of 24 endourology fellowships offer dedicated HoLEP training (4). This reflects current nationwide trends: almost one-third of states in America have no HoLEP surgeons (3,5).
It is likely that these trends are in part due to the steep learning curve required to master the HoLEP (6). As a three-dimensional surgery that must be performed via two-dimensional interpretation, HoLEP relies on accurate depth perception, anatomic orientation, and tissue-plane recognition. The necessary and intentional distortion of these planes adds another level of complexity. The surgeon must constantly be aware of how they are distorting normal anatomy and adapt to the new anatomy created. Some have suggested that prior experience with TURP may improve HoLEP learning, however this has not been explicitly studied (7).
In a survey of 10 residents, the average learning curve for HoLEP was estimated to be greater than 25 cases, with over 50% of residents stating over 50 cases were needed for mastery (8). Apical dissection is considered the most difficult portion of the case (7,8). Simulation does shorten the learning curve for several urologic procedures, and has used to assess perceived difficulty of performing a HoLEP (9). However, simulation is relatively rare for HoLEP compared to TURP (10).
Objective
To our knowledge, simulation has not been used to assess how well learners can follow and perceive recordings of HoLEP spatially. Therefore, the objective of this study was to assess spatial perception of urology residents when watching HoLEP, to better understand how HoLEP training can be improved. We present this article in accordance with the STROBE reporting checklist (available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0443/rc).
Methods
This was a cross-sectional, simulation-based observational study performed during an academic urology conference. A previously recorded HoLEP procedure was shown to urology resident physicians in this standardized educational setting.
A previously recorded HoLEP procedure was shown to urology resident physicians in a standardized educational setting. The video was paused at five predetermined, consecutive intraoperative time points: the verumontanum, the left apical posterior corner, the midline anterior bladder neck, the right posterior bladder neck, and the right apical posterior corner. These points were selected a priori by the two expert surgeons to span the temporal course of the enucleation, to contrast an undistorted anatomic landmark (the verumontanum) with locations subject to progressive intentional tissue-plane distortion (bladder neck and apical corners), and to represent anatomy that trainees are expected to recognize. Learners were not told which anatomic locations the time points corresponded to.
At each pause, learners localized the laser tip by marking coordinates on a standardized schematic prostate depicting coronal, axial, and sagittal views, with a fixed coordinate grid common to all participants and to the expert reference (Figure 1). Reference coordinates were established by two fellowship-trained HoLEP practitioners (P.X., A.E.K.), who have performed over 2,500 HoLEP procedures combined. Each annotated every time point and dimension independently, and discrepancies were reconciled by consensus. Because no external positional reference (e.g., electromagnetic tracking or out-of-body imaging) was available, this expert consensus served as the “accurate” point, the reference standard against which resident annotations were compared.
For each time point and dimension, the resident’s coordinate and the expert consensus coordinate were transferred to graph paper at a fixed scale, and the straight-line (Euclidean) distance between them was measured in centimeters by a single investigator. Accuracy was defined as this distance, with smaller distances indicating greater concordance; precision within a group was defined as the standard deviation of these distances about the reference coordinate.
The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. In accordance with the U.S. Department of Health and Human Services regulations [45 Code of Federal Regulations (CFR) 46], this study did not require institutional review board review, as it was limited to an educational test procedure in adult volunteers in an educational setting and no identifiable private information was collected. Informed consent was obtained from the participants.
Statistical analysis
Learners were grouped by prior HoLEP exposure (a binary yes/no) and post-graduate level (post-graduate year, PGY). Each reported between-group comparison was conducted within a single time point and dimension, where each participant contributes one coordinate; observations within a given comparison are therefore independent. We did not pool repeated measurements within participants in any significance test.
Accuracy amongst groups was compared with t-tests and analysis of variance (ANOVA) with Tukey’s post-hoc analysis confirming significance with P value less than 0.05. Analysis was performed using IBM SPSS 2 29 (SPSS, Chicago, IL, USA).
Results
A total of 21 residents participated in the study. As there were five time points for three dimensions, there were a total of 315 coordinates. Ten participating residents (47.6%) had prior HoLEP exposure. An example of the schematic prostate is shown in Figure 1.
Residents were grouped by PGY-level: intern (n=6), junior (n=8), and senior (n=7). Accuracy of coordinates was calculated for each time point for each dimension and was assessed overall (Table 1).
Table 1
| Parameter | Overall accuracy | Overall precision | Accuracy grouped by prior HoLEP exposure | Accuracy grouped by PGY-level | |||||
|---|---|---|---|---|---|---|---|---|---|
| No, n=11 | Yes, n=10 | P value | Intern, n=6 | Junior, n=8 | Senior, n=7 | P value | |||
| P1-C | 3.00 | 2.93 | 4.44 | 1.41 | 0.04 | 5.78 | 2.66 | 0.99 | 0.03 |
| P1-A | 5.93 | 3.72 | 5.32 | 7.12 | 0.54 | 5.83 | 5.04 | 7.76 | 0.74 |
| P1-S | 4.35 | 5.37 | 8.9 | 5.67 | 0.24 | 8.01 | 9.77 | 4.05 | 0.20 |
| P2-C | 4.63 | 3.31 | 5.29 | 5.54 | 0.89 | 7.2 | 4.83 | 4.54 | 0.47 |
| P2-A | 11.89 | 3.08 | 14.03 | 11.59 | 0.40 | 16.02 | 9.66 | 13.82 | 0.18 |
| P2-S | 7.27 | 3.40 | 8.86 | 7.67 | 0.37 | 9.54 | 8.37 | 7.14 | 0.36 |
| P3-C | 3.57 | 3.33 | 6.43 | 5.32 | 0.55 | 6.62 | 7.59 | 3.36 | 0.12 |
| P3-A | 5.87 | 3.21 | 9.39 | 8.93 | 0.848 | 9.52 | 10.85 | 6.95 | 0.37 |
| P3-S | 7.55 | 4.19 | 10.82 | 8.49 | 0.44 | 12.16 | 10.92 | 6.24 | 0.24 |
| P4-C | 3.55 | 4.43 | 7.88 | 3.28 | 0.059 | 7.55 | 6.74 | 2.9 | 0.28 |
| P4-A | 19.10 | 5.12 | 22.29 | 18.17 | 0.31 | 23.19 | 21.54 | 16.49 | 0.39 |
| P4-S | 11.50 | 4.70 | 15.31 | 10.28 | 0.15 | 18.25 | 12.98 | 8.27 | 0.07 |
| P5-C | 3.90 | 3.09 | 6.42 | 3.15 | 0.14 | 7.27 | 6.1 | 1.39 | 0.06 |
| P5-A | 9.55 | 4.04 | 14.1 | 10.01 | 0.11 | 13.65 | 11.39 | 11.75 | 0.77 |
| P5-S | 4.83 | 4.02 | 7.82 | 5.28 | 0.35 | 9.48 | 7.67 | 2.94 | 0.12 |
| Coronal overall | 3.73 | 3.42 | 6.09 | 3.74 | NA | 6.88 | 5.58 | 2.64 | NA |
| Axial overall | 10.47 | 3.83 | 13.03 | 11.16 | NA | 13.64 | 11.70 | 11.35 | NA |
| Sagittal overall | 7.10 | 4.34 | 10.34 | 7.48 | NA | 11.49 | 9.94 | 5.73 | NA |
| P1 overall | 4.43 | 4.01 | 6.22 | 4.73 | NA | 6.54 | 5.82 | 4.27 | NA |
| P2 overall | 7.93 | 3.26 | 9.39 | 8.27 | NA | 10.92 | 7.62 | 8.50 | NA |
| P3 overall | 5.66 | 3.58 | 8.88 | 7.58 | NA | 9.43 | 9.79 | 5.52 | NA |
| P4 overall | 11.38 | 4.75 | 15.16 | 10.58 | NA | 16.33 | 13.75 | 9.22 | NA |
| P5 overall | 6.09 | 3.72 | 9.45 | 6.15 | NA | 10.13 | 8.39 | 5.36 | NA |
A, axial; C, coronal; HoLEP, holmium laser enucleation of the prostate; NA, not available; P, pause time point; PGY, post-graduate year; S, sagittal.
Learners perceived more accurately in the coronal dimension and were most accurate in identifying the verumontanum, which corresponded to the first time point of the procedure. Both prior HoLEP exposure and senior training level were associated with significantly greater concordance at the verumontanum in the coronal dimension (P=0.04 and P=0.03, respectively). No significant association was found between prior HoLEP exposure or PGY level and concordance at the remaining time points across dimensions. In a sensitivity analysis collapsing each resident to a single mean distance across all coordinates, higher PGY level remained associated with greater overall concordance (one-way ANOVA, P=0.03), whereas prior HoLEP exposure was not significantly associated with accuracy (mean distance 7.46 vs. 9.82 units; P=0.06).
Discussion
Key findings
In this observational study of spatial understanding of HoLEP planes, urology residents localized the laser fiber tip most accurately in the coronal dimension and at the verumontanum. Prior HoLEP exposure and senior level training were associated with correctly identifying the verumontanum in the coronal view. However, even residents with prior HoLEP exposure struggled to identify later operative locations, especially in axial and sagittal planes.
Strengths and limitations
This study included residents from multiple academic institutions, thus improving generalizability as resident education varies from one place to another. It provides insight into which areas to focus on when teaching HoLEP. For example, depth perception (as gauged by the axial view) is difficult to assess on a two-dimensional level, and yet is essential for preventing complications such as bladder neck or capsular injury. Furthermore, the variation in prostate size is most likely to affect the axial depth perception. Although not explicitly studied in this setting, being able to feel the weight of the prostate tissue against the endoscope would likely improve sagittal spatial perception.
Our study has notable limitations. First, accuracy reflects a consensus coordinate based on fellowship-trained expertise. Future work incorporating an external positional reference—an out-of-body camera capturing scope and hand position, electromagnetic tracking, or a phantom-based correlate—would permit validation against true tip location. Second, we did not stratify HoLEP exposure by level of involvement (e.g., observed, assisted, or independently performed). Finally, this was a single-session pilot study of 21 residents with subgroups of six to eight residents. The study was therefore likely underpowered to detect modest between-group differences, and the absence of a significant association at the remaining time points may reflect both the failure to more accurately define HoLEP exposure and a small cohort.
Comparison with similar research
Multiple studies have shown that at least 25 to 50 HoLEP cases are needed to start feeling proficient (3,11,12). While HoLEP is known to have a steep learning curve, few studies have explicitly demonstrated why this is the case. Research on simulation-based education in HoLEP is sparse (10). An endoscopic enucleation simulation utilizing three-dimensional organ phantom simulator made of hydrogels has been previously described (13). Until such simulators can become more widely adopted, simple and low-cost solutions to test trainees are needed. To our knowledge, no study has assessed mapping during HoLEP observation as a method of understanding the learners thought process.
Explanations of findings
Our preliminary, hypothesis-generating study highlights certain limits in experiential learning for conferring three-dimensional orientation throughout HoLEP. That the verumontanum was most easily identified in our study is unsurprising, as this is a known anatomic landmark seen in every transurethral surgery and is intentionally not subject to tissue distortion. However, other “landmarks” including the bladder neck, external sphincter, and apical corners are less likely to be identified as they are manipulated during the surgery. The current study identifies areas for improvement in HoLEP training even for trainees who are more experienced: axial depth perception, sagittal orientation, and recognition of distorted surgical planes.
Implications and actions needed
Appropriate identification of prostatic planes is essential during HoLEP. Spatial mapping is a relatively simple way of testing the learners’ ability to envision the intra-prostatic planes in three-dimensions. HoLEP simulation models and real-world teaching may find greater success in focusing on deliberate spatial mapping, annotated videos, real-time teaching focused on depth perception, axial and sagittal orientations, and recognition of evolving surgical planes.
Conclusions
As HoLEP is becoming the new gold standard for BPH surgical treatment, both simulation and real-world teaching should ensure mastery of the spatial ‘map’ of HoLEP anatomy, with a focus on understanding axial and sagittal dimensions.
Acknowledgments
This work was initially presented at the 2025 World Congress of Endourology and Urotechnology (WCET) meeting by P.X.
Footnote
Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0443/rc
Data Sharing Statement: Available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0443/dss
Peer Review File: Available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0443/prf
Funding: None.
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0443/coif). A.E.K. is a consultant for Richard Wolf, Karl Storz, and Boston Scientific, as well as a member of the Data Safety Monitoring Board of Uriprene. None of these companies supported the current work. P.X. is a consultant for Richard Wolf, which did not support the current work. The other authors have no conflicts of interest to declare.
Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. In accordance with the U.S. Department of Health and Human Services regulations (45 Code of Federal Regulations 46), this study did not require institutional review board review, as it was limited to an educational test procedure in adult volunteers in an educational setting and no identifiable private information was collected. Informed consent was obtained from the participants.
Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.
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