Response to letter to the editor re 'ventral penile curvature estimation using an app

The Natural (non-invasive) Erection Test: Is it a reliable alternative to the artificial erection test?

AIM OF THE STUDY

To test the accuracy and reliability of the natural erection test (NET) as compared to the artificial erection test in assessing penile curvature in hypospadias.

MATERIALS AND METHODS

50 children underwent both natural and artificial erection tests intraoperatively between January 2020 and October 2021. These included 5 glandular, 26 distal, 9 proximal, and 10 perineal hypospadias patients with curvature. The mean follow up period was 20 months (range 16-37). Under anesthesia, the curvature was assessed before degloving, then after degloving using both the natural and the artificial erection test. The NET test was repeated after curvature correction (3 times per patient). The measurements were analyzed using paired t-test.

TECHNIQUE OF NATURAL ERECTION TEST

Two fingers of the left hand press just below the symphysis pubis to stop blood drainage from the penis and two fingers of the right hand massage the blood from the perineum distally into the penis until it becomes hard without tourniquet. The standard artificial erection test was performed using saline injected through a butterfly needle into the corporeal bodies without tourniquet. Photos were taken of both tests using the exact angle and angle of curvature was measured using Angle Meter App.

RESULTS

There was no statistically significant difference between both erection tests with a P value of 0.705. The Bland-Altman plot also showed that all studied children have a difference in their natural and artificial erection tests within the limits of agreements.

DISCUSSION

Erection is commonly induced using the artificial saline injected erection test first described by Gittes and less commonly using pharmaceutical erection test first described by Perovic. The severity of chordee apparent during artificial erection test varies with the amount of pressure used during injection. Also, it is difficult to place the tourniquet proximal enough to detect chordee at the base of the penis. It may be associated with hematoma formation, oedema, postoperative pain and the need for multiple punctures to assess the curvature before and after repair. Disadvantages of the pharmacological-induced erections in hypospadias include increased blood loss during erection, additional cost, and the need for a reversal agent. The natural erection test mimic the normal erection mechanism and may avoid all these potential disadvantages.

CONCLUSION

The study showed that the natural erection test is easy to perform, non-invasive, non-traumatic and can be repeated several times intraoperatively without the need of repeated puncturing of the corpora cavernosa and avoids the potential risks and complications of the artificial erection test.

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.

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.

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.

Dorsal penile curvature and megameatus intact prepuce hypospadias: A common association in a rare variant of hypospadias

BACKGROUND

Megameatus intact prepuce (MIP) is a rare variant of hypospadias. Unlike the hooded ventrally absent prepuce in non-MIP hypospadias, the prepuce in MIP hypospadias is fully circumferential and intact. The distal urethra remains wide with a deep glanular groove. While ventral curvature is a common finding in non-MIP hypospadias, neither ventral nor dorsal penile curvature has been reported in MIP hypospadias.

OBJECTIVE

To assess the association of the MIP hypospadias variant with penile curvature.

STUDY DESIGN

We retrospectively reviewed the medical records of all children who underwent hypospadias repair and identified those who were documented as having the MIP variant of hypospadias and operated in our center from January 1998 to June 2020. The patients were considered as having MIP hypospadias if no hypospadias had been evident before circumcision, if a circumferential circumcision scar was present (instead of the inverted V-shaped scar in the ventral aspect of the penis following circumcision of the hooded prepuce associated with non-MIP hypospadias), and if there was a wide meatus. Penile curvature was diagnosed intraoperatively by an artificial erection test that uses saline solution for injection. Patients were considered surgical candidates if the degree of curvature was equal to or greater than 30°.

RESULTS

The study cohort consisted of 118 male children who were identified as having the MIP hypospadias variant according to the inclusion criteria. The median age at repair was 1.1 years (interquartile range 8 months to 1.6 years). Penile curvature was found in 29 children (24%), of whom 23 had dorsal curvatures (19%) and 6 had ventral curvatures (5%).

DISCUSSION

MIP hypospadias is associated with penile curvature, and more frequently with dorsal than ventral curvature. This study is retrospective and does now identify specific features of MIP associated with penile curvature. We encourage pediatric urologists to perform an artificial erection test intraoperatively in children with the MIP variant and repair associated curvatures.

CONCLUSIONS

A dorsal curvature was found in 19% of patients with a MIP variant of hypospadias, and most of them (86%) required ventral plication due to the severity of the curvature.