Evaluation of penile curvature in patients with hypospadias; gaps in the current practice and future perspectives

Hypospadias-associated penile curvature assessment and management: A global survey of current practice

INTRODUCTION

Our goal was to assess how surgical management of hypospadias-associated penile curvature (HAPC) varies across continents, focusing on factors that influence assessment and decision-making.

METHODS

Members of the European Society of Pediatric Urology (ESPU), Society of Pediatric Urology (SPU), and Hypospadias International Society (HIS) participated in an anonymous, 34-question online survey addressing pre-, intra-, and postoperative elements of HAPC evaluation and management. A selection of intraoperative photos were included in the survey to investigate the prevailing surgical approaches and identify management patterns.

RESULTS

Out of the 267 participants, 38.4% of them are located in Europe. Visual estimation was the predominant approach for evaluating HAPC, although being regarded as the least dependable compared to other techniques. Surgeons who performed more than 40 cases per year were more inclined to use goniometers and had varying degrees of HAPC that were considered acceptable without requiring any correction (P < .001). Out of 58% of respondents, a significant number reported regular utilization of artificial erection tests for all categories of hypospadias. Surgeons with fewer than 10 years of expertise commonly utilized erection test as part of their regular practice. A tourniquet was employed to maintain sufficient intra-corporeal pressure, by134 (50%). 116 participants (43%) inject Saline through the corpora cavernosa through the glans, while 150 (56%) administer saline from the lateral aspect. Moreover, the decision-making process differed based on the intraoperative picture scenarios of mild to moderate penile curvature during erection testing. Contrary to temperatures ranging from 25o to 35o, decision-making in cases with less severe degrees of HAPC was uncomplicated.

CONCLUSION

This survey reveals a wide range of surgical practice patterns in the assessment and management of HAPC. To our knowledge, this global survey of HAPC practice is the largest to date and could aid in developing new guidelines in pediatric urology. These findings may also provide a foundation for future prospective multinational studies.

Outcome analysis of staged preputial graft technique for primary proximal hypospadias with and without post-operative vacuum physiotherapy

PURPOSE

Management of proximal hypospadias remains challenging. We assessed the results of staged preputial graft repairs (SPG) for proximal hypospadias and hypothesize that post-operative vacuum physiotherapy (VP) improves graft suppleness and overall outcomes.

MATERIALS AND METHODS

Retrospective analysis of n = 71 patients with proximal hypospadias and severe ventral penile curvature (PC) of ≥50° after degloving. PC was corrected using ventral transverse incisions of the tunica albuginea (VTITA) without applying a tourniquet, taking care to avoid injuring the underlying erectile tissue. The ventral raw area at the penile shaft, including VTITA, were covered with either divided and partially mobilized urethral plate, or with the inner preputial graft itself. During the second stage, a tunica vaginalis flap was often used to cover the tubularized neourethra. Outcomes and post-op complications were assessed after each stage, comparing patients who received vacuum physiotherapy (VP+, n = 49) with those who did not (VP-, n = 22).

RESULTS

Mean PC was 66°, average follow-up duration was 13.01 months, and overall complication rate was 22.5%. Only 6 of 49 VP + patients experienced complications (12.24%; 4 fistulas; 2 urethral strictures) and no recurrence of PC after second stage was observed in this group. VP- patients displayed a significantly higher rate of complications, with 10 of 22 cases (45.45%) exhibiting fistula development (n = 5) and glans dehiscence (n = 5). Recurrence of mild PC after first-stage repair was comparable between patient groups (12% VP+, 18% VP-) and easily corrected by simple graft tubularization or dorsal plication during second-stage repair.

CONCLUSIONS

Staged repair using VTITA is effective for correcting proximal hypospadias with severe chordee. VP appears to promote and expedite graft suppleness and significantly improves patient outcomes.

What is the angle of a banana? The difficulty in reliable assessment of hypospadias chordee

INTRODUCTION

The degree of chordee associated with hypospadias impacts operative management. Unfortunately, poor inter-observer reliability in assessing chordee by multiple methods in vitro has been demonstrated. This variability may be related to the fact that chordee is not a discrete angle, but rather an arc-like curvature similar to that of a banana. On an attempt to improve this variability, we assessed the inter-rater reliability of a novel method of chordee measurement and compared it to measurements with a goniometer both in vitro and in vivo.

MATERIALS AND METHODS

In vitro assessment of curvature was performed using 5 bananas. In vivo chordee measurement was performed during 43 hypospadias repairs. On in vitro and in vivo cases, chordee was assessed independently by faculty and resident physicians. Angle assessment was performed in a standard manner with a goniometer and with a smartphone app using ruler measurements of the length and width of the arc (Summary Figure). The proximal and distal aspect of the arc to be measured was marked on the bananas, whereas the penile measurements were taken from the penoscrotal to the sub-coronal junctions.

RESULTS

In vitro banana assessment demonstrated strong intra- and inter-rater reliability for length (0.89 and 0.88, respectively) and width measurements (0.97 and 0.96). The calculated angle demonstrated an intra- and inter-rater reliability of 0.67 and 0.67. The banana goniometer/protractor measurements were weak with an intra-rater and inter-rater reliability of 0.33 and 0.21. With hypospadias chordee, the inter-rater reliability was strong for length and width measurements (0.95 and 0.94) and 0.48 for calculated angle. The inter-rater reliability of the goniometer angle was 0.96. Further assessment of inter-rater goniometer reliability was performed relative to degree of chordee as characterized by faculty. The inter-rater reliability for ≤15°, 16-30, and ≥30° was 0.68 (n = 20), 0.34 (n = 14), and 0.90 (n = 9), respectively. When the goniometer angle was classified as ≤15, 16-30, or ≥30° by one physician, it was classified outside of this range by the other physician 23%, 47%, and 25% of the time, respectively.

DISCUSSION

Our data demonstrate significant limitations of the goniometer for assessing chordee in vitro and in vivo. We were unable to demonstrate significant improvement in chordee assessment using arc length and width measurements to calculate radians.

CONCLUSIONS

Reliable and precise techniques for measuring hypospadias chordee remain elusive and draw into question the validity and usability of management algorithms employing discrete values.

Unaided visual assessment of ventral curvature during hypospadias repair is inferior to objective measurement using app goniometry

OBJECTIVE

Failure to perform artificial erection or objectively assess ventral curvature (VC) during primary hypospadias repair is an important reason for residual/ recurrent chordee. The present study compares the accuracy of unaided visual inspection (UVI) with objective VC assessment using smartphone application (app) goniometry.

METHODS

All patients who underwent primary hypospadias repair between January 2021 and September 2022 were included. Assistant surgeons were asked to grade the degree of VC on UVI (after degloving and an artificial erection test) into: none, mild (<30 degree), severe(>30 degree). Lateral profile photograph was taken and angle measurement was performed on an android mobile application (Angulus). Correlation was performed with both methods of assessment.

RESULTS

During this period a total of 210 patients were analyzed; VC was noted in 40/138 (29%) cases of distal and in 62/72 (86%) cases of proximal hypospadias. Erroneous visual inspection was noted in 41/210 (20%; 95% CI 14-25%) on UVI (15 erroneously marked none while 26 marked mild). Among those found to have chordee, UVI assessed 39/82 (47%) as severe while app goniometry assessed 65/97 (67%) as severe. There was significant relative risk of labelling severe chordee as a mild one by UVI: 1.4 (95%CI 1-1.8; p=0.01).

CONCLUSIONS

UVI was erroneous in 20% of cases. UVI was less accurate in differentiating severe chordee from mild one. In 60% patients UVI alone could have led to erroneous VC assessment and thus wrong selection of technique. Further studies are required to validate our findings and standardize VC measurement using an app goniometry.

Current perspectives in hypospadias research: A scoping review of articles published in 2021 (Review)

Hundreds of papers are written about hypospadias every year referring to all aspects of the pathology, being one of the most common congenital malformations. The present study conducted a scoping review of articles published in 2021 to present the main issues and summarize current perspectives and achievements in the field. It searched for the keyword 'hypospadias' in the three most popular databases (PubMed, Scopus and Web of Science). After the analysis of the publications, they were categorized into different domains. The present review was performed respecting the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA ScR) guidelines. A total of 284 articles were included. These were published in 142 different journals. The most accessed was the Journal of Paediatric Urology with 54 articles. The main identified domains were related to surgical techniques, postoperative care, complications, anesthesia, anatomical factors, genetics, environmental factors, endocrinology, associated malformations, questionnaires and recommendations, management, biological materials, animal models, retrospective studies of centers, social media, bibliometrics, small gestational age, neoplasm, or fertility. Promising modifications of existing surgical techniques were presented with improved outcomes for both the proximal and distal types of hypospadias. Relevant anatomical and etiological, and also genetic factors were clarified. Aspects of the peri- and postoperative management referring to the antibiotherapy, analgesia, dressing techniques, and the future use of novel bioengineering agents to prevent, reduce or treat the occurring complications were discussed.

A new method for measuring penile curvature based on digital images

INTRODUCTION AND OBJECTIVE

Accurate and objective assessment of penile curvature is considered a critical evaluation in patients with hypospadias, as it often determines if a 1 or 2-stage procedure should be done. Due to the ease of acquisition and reusability of digital images, more research is focused on digital images; however, the current method based on digital images is not an easily accurate and objective evaluation of penile curvature amongst surgeons. In scoliosis, the Cobb method is a standard method to quantify spinal curvature. Therefore, this study introduces a new accurate, and standardized method for measuring penile curvature based on the digital image concerning the Cobb method.

METHODS

Twenty-two subjects were randomly selected, including 11 pediatric urologists with experience in goniometry(professional group)and 11 non-pediatric urologists without experience in goniometry (non-professional group). A total of 9 two-dimensional images of penile curvatures from 10° to 90°were obtained and stored in the research project notebook. Subjects measured 9 digital images using the new method (fixed anatomical position method) and classical method (the angle created by the interception of two ideal lines, one passing along the proximal portion of the corpora and a second passing through the tip of the penis), respectively. Measurement error was calculated as the absolute difference between the true curvature and the subject estimation. A t-test was used to evaluate the significant differences between the methods.

RESULTS

A total of 22 subject measurement data were obtained. Mean errors using the new method ranged from 1.06° to 3.50°, compared to 3.84°to 11.83°for classical method. Mean errors were significantly lower (p < 0.05) when using the new method compared to the classical method. A subgroup comparing subjects with and without prior experience with goniometry showed a statistically significant difference only for the classical method when the penis curvature is 10-40°, the mean error range of the professional group was 7.8°-9.56°, compared to 10.34°-13.02°for nonprofessional group.

DISCUSSION

We emphasize the importance of penile curvature measurement and urgent need for an accurate measurement method, and then we focus on the new method compare with the previously described methods looking at mean errors and explain the reason that the new method why is accurate. Subsequently, we focus on explain the impact of experience measurement methods. Finally, the shortcomings of this paper and the prospective points are discussed:1) how to obtain more photos in practical situations; 2) using artificial intelligence methods for automatic marking of key points to achieve efficient measurement of penile curvature.

CONCLUSIONS

In this preliminary study, we demonstrated better penile curvature estimations using the new method compared to the classical methods currently used by pediatric urologists.

Automated measurement of penile curvature using deep learning-based novel quantification method

Objective

Develop a reliable, automated deep learning-based method for accurate measurement of penile curvature (PC) using 2-dimensional images.

Materials and methods

A set of nine 3D-printed models was used to generate a batch of 913 images of penile curvature (PC) with varying configurations (curvature range 18° to 86°). The penile region was initially localized and cropped using a YOLOv5 model, after which the shaft area was extracted using a UNet-based segmentation model. The penile shaft was then divided into three distinct predefined regions: the distal zone, curvature zone, and proximal zone. To measure PC, we identified four distinct locations on the shaft that reflected the mid-axes of proximal and distal segments, then trained an HRNet model to predict these landmarks and calculate curvature angle in both the 3D-printed models and masked segmented images derived from these. Finally, the optimized HRNet model was applied to quantify PC in medical images of real human patients and the accuracy of this novel method was determined.

Results

We obtained a mean absolute error (MAE) of angle measurement <5° for both penile model images and their derivative masks. For real patient images, AI prediction varied between 1.7° (for cases of ∼30° PC) and approximately 6° (for cases of 70° PC) compared with assessment by a clinical expert.

Discussion

This study demonstrates a novel approach to the automated, accurate measurement of PC that could significantly improve patient assessment by surgeons and hypospadiology researchers. This method may overcome current limitations encountered when applying conventional methods of measuring arc-type PC.

Pediatric urologists' confidence and accuracy in estimating penile curvature

BACKGROUND

Assessment and management of congenital penile curvature (PC) can be variable. Methods for correction of PC usually are dependent on degree of PC which is reliant on how degree is assessed. We sought to assess the confidence and accuracy of measuring PC and hence management using case-based examples.

METHODS

A survey was emailed to members of the Societies for Pediatric Urology. Demographic information, management strategies for PC, and self-reported confidence in measuring PC were assessed. A Likert scale measured self-confidence. Case scenarios were used to assess ability to measure PC and methods of correction. The cases consisted of three computer-generated penis model images with arc-type ventral curvature and one image of lateral curvature in an infant.

RESULTS

The response rate was 30% (108/355). The mean confidence score was 3.6 ± 0.8 (3-fairly confident; 4-very confident). In clinic, 89% of urologists used eyeball estimates to assess PC; 5% used both eyeball and goniometer. In the operating room, 71% used eyeball estimates, 8% used goniometer, and 16% used both. If sole decision-maker, urologists recommend surgical correction of PC over observation at median 30° (IQR 21-30°). At a median of 45°, there was a shift in corrective surgical preference from dorsal plication (DP) (IQR 30-54°) to ventral lengthening (IQR 34-60°). Urologists underestimated PC degree for all cases (summary table). For all cases, there was no association between years in practice or confidence level on estimated PC degree. In case 1, only 24% of urologists would correct a mean estimate of 23° PC; those who would correct had a higher mean PC estimate vs those who would not (28° vs 21°, p < 0.001). Case 2 and 4 had similar estimations and correction methods. In case 2, those who chose VL had a higher mean PC estimate vs those who did not (43° vs 37°, p < 0.01), but no estimate difference was seen for DP (p = 0.52). In case 4 with lateral PC, those who chose DP had a higher mean PC estimate vs those who did not (41° vs 33°, p = 0.049). Yet in case 3, there was no difference in PC estimate in urologists who chose VL vs not (57° vs 53°, p = 0.16).

CONCLUSIONS

A uniform underestimation of PC existed despite self-reported confidence in the ability to measure PC. An increasing willingness to perform surgical correction was demonstrated with a shift towards VL for ventral curvature and less so for lateral curvature as PC worsens.

An objective hypospadias classification system

OBJECTIVE

Current approaches to classifying hypospadias severity are based on meatus position. These classification tools lack precise reflection on the degree of urethral hypoplasia and extent of urethral underdevelopment hence are not good representative of hypospadias severity. Here, an alternative classification system is introduced that objectively reflects the developmental pathology underlying this condition. The study goal was to appraise location of bifurcation in the corpus spongiosum (BCS) relative to the penile shaft as an indicator of hypospadias severity.

PATIENTS AND METHODS

Patients aged <18 years with primary hypospadias were included in the study. Urethral defect ratio (UDR) was calculated by dividing the extent of urethral defect (distance between the glandular knobs and BCS) relative to stretched penile length (SPL). Hypospadias severity was then categorized into three distinct grades (UDR <0.5, 0.5-0.99, ≥1.0). The Inter-Class Correlation (ICC) was evaluated to assess the intra- and inter-rater agreement between the reviewers of UDC ratio. Linear regression analysis was performed to estimate the correlation between UDC ratios and either plate objective scoring tool (POST) and Curvature degrees.

RESULTS

A total of 67 patients aged 12.3 ± 3.7 months with primary hypospadias were enrolled. UDR ranged between 0.2 and 1.3. A significant difference in hypospadias level was observed between UDR grades, which further correlated degree of curvature (P < 0.0001), urethral plate quality (P < 0.0001), and associated anomalies (P < 0.05). The Inter-Class Correlation (ICC) value to examine the intra- and inter-rater agreement between the two reviewers in UDC ratio was 0.998 (95% CI 0.998, 0.999). Regression analysis revealed that UDR and both POST and Curvature degree were significantly associated (P < 0.001).

CONCLUSIONS

A hypospadias severity scoring system based on embryological etiology and urethral hypoplasia and assessed relative to the penile shaft represents an objective, feasible, and consistent tool. These results clearly indicate that the reviewers have had excellent consistency/reliability across their consecutive readings. This new system can facilitate objective description of hypospadias-spectrum anomalies and thus support precise communication between individual surgeons and centers.

How accurate is eyeball measurement of curvature? A tool for hypospadias surgery

INTRODUCTION

Correction of penile curvature or "chordee" is a major component in the management of hypospadias. Accurate assessment and management of penile curvature influence both short- and long-term outcomes of surgery.

AIM OF THE STUDY

The objective of this study is to investigate the accuracy of eyeball measurement and how does it compare to objective measurement by standard goniometry (SG) and smartphone app goniometry (AG).

MATERIALS AND METHODS

A Dropbox file request link was shared with paediatric urologists on various social media platforms requesting participants to upload a picture of their index finger showing what they thought 30 degrees of curvature look like using their proximal inter phalangeal joint as the point of maximal curvature., The images were assessed using SG to measure the angle of curvature. The images were also assessed using AG by the principal investigator, a physician, a scrub nurse and a paediatric urology consultant., Statistical analysis was performed using SPSS statistics software version 26 (Armonk, NY: IBM Corp). A one sample t-test and a one-way chi squared test were used to evaluate significant frequency differences. Pearson correlation was used to compare AG measurements to test intra- and inter-observer reliability and to compare AG measurements vs SG measurements. Assuming 5-degree variability in goniometer measurements and 2-degree difference between the sample and population, the number of participants needed was calculated to be 49.

RESULTS

Fifty-two responses were received.32.7% of respondents simulated 30° accurately (17/52). A significant proportion (23/52, 44.2%) overrepresented the degree of curvature and 23.1% (12/52) underrepresented it (p = 0.01). Compared with objective measures, eyeball estimates differed by an average of 10° ± 1.5 SE. Measurements obtained by AG were comparable to measures obtained by SG and showed excellent intra-observer and inter-observer correlation (R = 0.983, P < 0.001).

DISCUSSION

We demonstrated a significant discrepancy between eyeball assessment of curvature and objective measurements in a cohort of hypospadiologists. This can be very relevant to intraoperative decision making. The limitation of the study is the use of a simulated model rather than assessment of curvature in patients with hypospadias. Another limitation is the lack of standardization of the way the pictures were taken.

CONCLUSION

We demonstrated a tendency among hypospadiologists to overestimate or underestimate curvature by an average of 10° on eyeball assessment. The use of App Goniometry shows excellent interobserver reliability and is comparable to standard goniometry in curvature assessment.

Plate Objective Scoring Tool: A new preoperative indicator of penile curvature degree in children with distal hypospadias

OBJECTIVES

There is an unmet need for preoperative methods that surgeons can use to objectively quantify hypospadias anatomic variables and determine risk of penile curvature. We, therefore, assessed whether Plate Objective Scoring Tool measurements were correlated with degree of ventral curvature in affected children.

METHODS

Patients undergoing distal hypospadias repair were enrolled into the study between January 2018 and December 2020 and were categorized independently by at least two surgeons using Plate Objective Scoring Tool. Scores were compared statistically to determine the degree of ventral curvature and requirement for correction.

RESULTS

Sixty-five patients with a median age of 18 months (interquartile range 13-26) were enrolled into the study prior to surgery for primary distal hypospadias. Patient probability of significant postoperative curvature (>20°) was determined with moderate confidence using a cutoff Plate Objective Scoring Tool score of 1 (sensitivity 75%, specificity 60%). Presurgery Plate Objective Scoring Tool scores were negatively correlated with subsequent degree of curvature (r = -0.37, P = 0.003), with values <1.0 predicting >20° curvature.

CONCLUSIONS

Plate Objective Scoring Tool scoring offers a succinct method of describing hypospadias severity and correlates well with postoperative outcomes. The Plate Objective Scoring Tool system can therefore be used to objectively predict the likelihood of penile curvature and aid communication between surgeons and researchers, as well as improving parental counseling.

Ultrasonographic Evaluation of the Hypospadiac Penis in Children

INTRODUCTION

Identifying key anatomical features of the hypospadiac penis is crucial to better understanding this pathology and guiding surgical reconstruction plans, thereby achieving superior functional and cosmetic outcomes.

OBJECTIVE

To Assess the feasibility and precision of penile ultrasonography (PUG) in determining key structural features for hypospadias cases (including distal extent of the spongiosal component of the urethral plate, to elucidate the healing process following tubularised incised-plate urethroplasty).

PATIENTS AND METHODS

Twenty-five children with hypospadias were assessed using PUG prior to surgical repair and then again under general anesthesia. Preoperative images were acquired using ultrasonography in sagittal and transverse planes, then later compared with anatomical findings obtained during surgical repair of urethral hypoplasia.

RESULTS

Median patient age was 1.2 years (range 0.5-12) and hypospadias types included coronal 17/25 (68%), mid-penile 5/25 (20%), and proximal penile 3/25 (12%). Distinct layers of the corpus spongiosa and mucosal layer, Buck fascia, tunica albuginea, glans, corpora cavernosa, and penile skin were delineated so that their spatial inter-relationship could be assessed. Distal extent of the spongiosal component of the urethral plate was determined by the mid-glans B-B line. The extent of urethral hypoplasia identified by PUG was relatively similar to measurements obtained intraoperatively.

CONCLUSION

PUG is a feasible and accurate approach to evaluating penile configuration in children with hypospadias. Distal extent of the spongiosal component of the urethral plate was accurately determined, hence PUG could potentially be used to improve surgical planning and appraisal of current repair procedures.