|Year : 2018 | Volume
| Issue : 3 | Page : 144-147
Comparison of anatomical landmarks and dimensions in a hypospadiac glans with those of a normal glans
Anjan Kumar Dhua, Sachit Anand, Sandeep Agarwala, Veereshwar Bhatnagar
Department of Pediatric Surgery, AIIMS, New Delhi, India
|Date of Web Publication||4-Jul-2018|
Dr. Anjan Kumar Dhua
Department of Pediatric Surgery, Room No. 4002, Teaching Block, AIIMS, Ansari Nagar, New Delhi - 110 029
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Aim of the Study: The aim of this study is to establish ventral glans length (VGL), meatus (M) size, and their ratio VGL/M (R) in normal Indian boys and to compare these with the respective equivalent dimensions in boys with distal and mid-penile hypospadias using anatomic landmarks.
Methods: Normal boys were designated as Group A (n = 108), and the boys with hypospadias were designated as Group B (n = 81). The anatomical landmarks marked on the glans were measured using a digital camera and appropriate software.
Results: The mean age of the boys in Groups A and B was 4.26 ± 3.59 (range 0.5–12) and 3.82 ± 2.85 (0.7–11) years, respectively. The observed mean values in Group A for VGL-A, M-A, and R-A were 3.05 ± 1.27 (range 1.19–8.09), 4.3 ± 1.23 (range 1.61–7.04), and 0.8 ± 0.45 (range 0.27–2.1) mm, respectively. The observed mean values in Group B for VGL-B, M-B, and R-B were 3.77 ± 0.81 (range 12.41–5.2), 3.27 ± 0.71 (range 2.25–5.34), and 1.17 ± 0.26 (range 0.84–1.86) mm, respectively. Comparison of R-A and R-B showed a statistically significant difference (P < 0.0001).
Conclusions: The dimensions and the studied ratio between a hypospadiac glans and a normal glans differed significantly. The ratio between VGL and M was 0.8 in normal boys. In comparison, the ratio between the equivalent VGL and M in the hypospadiac boys was 1.17. During glansplasty in surgery for hypospadias, this factor should be taken into consideration to avoid the creation of long and tight ventral glans closure.
Keywords: Glans morphometry, glansplasty, hypospadias
|How to cite this article:|
Dhua AK, Anand S, Agarwala S, Bhatnagar V. Comparison of anatomical landmarks and dimensions in a hypospadiac glans with those of a normal glans. J Indian Assoc Pediatr Surg 2018;23:144-7
|How to cite this URL:|
Dhua AK, Anand S, Agarwala S, Bhatnagar V. Comparison of anatomical landmarks and dimensions in a hypospadiac glans with those of a normal glans. J Indian Assoc Pediatr Surg [serial online] 2018 [cited 2020 Sep 22];23:144-7. Available from: http://www.jiaps.com/text.asp?2018/23/3/144/235891
| Introduction|| |
The urethral meatus on a normal glans is a slit-like opening; the vertical length is measurable and so is the distance from the ventral tip of the meatus up to the coronal sulcus. A hypospadiac glans, although open, has equivalent characteristics and landmarks that may have a wide variation. The future meatus and length of glansplasty are outlined on the hypospadiac glans as hillocks around the open navicular fossa. These landmarks help a surgeon in planning the incisions for glansplasty. Glansplasty is a very important step in surgical correction of hypospadias; the aim is being to create a glans as similar to a normal glans in appearance. Hypospadias is considered as an embryopathy where there is an arrest in development of the urethra and the ventrum of the penis. It is reasonable to assume that these landmarks and the dimensions are likely to be different from the corresponding points and landmarks of a normal glans. This hypothesis is the basis of the current study. Differences, if any, may then dictate the modification or tailoring of incisions to match normal dimensions to achieve a near normal cosmesis and functional result.
| Methods|| |
This prospective study, carried out during June 2015–December 2016, was performed after approval of the institutional ethics committee (IEC/NP-196/08.05.2015). The study was carried out on two groups of patients designated as Groups A and B. Group A consisted of 108 boys who had normal external genitalia and were undergoing nonurological procedures under general anesthesia. In these patients, measurements of the meatus size (M-A) and the ventral glans length (VGL-A) and the ratio between the two (R-A) were used to establish norms for normal Indian boys which could then be used for comparison with Group B boys. Group B consisted of 81 boys, of similar age, who were treated for distal and mid-penile hypospadias. In the hypospadiac meatus, the dorsal tip of the open meatus is constant, but the ventral tip is represented by two hillocks on the lateral edge of the open navicular fossa. The distance from the dorsal meatal tip to the hillock represents the equivalent of the meatal length (M-B), and the distance from the hillock up to the coronal sulcus represents the VGL-B on the hypospadiac meatus [Figure 1]. The future meatus in the hypospadiac glans is usually formed by approximation of two hillocks on the lateral edge of the open navicular fossa.
|Figure 1: The images as they were captured with a measuring scale alongside to act as reference points for subsequent measurements (Group A, upper and middle rows and Group B, lower row). The sketches on the right side depict the same images with the various distances that were measured and analyzed|
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These anatomical landmarks were marked on the glans by a single surgeon. In both Group A and B boys, the images were captured using a digital camera (DSC H-20, Sony, Japan); a photograph of the glans along with a measuring scale was captured from approximately 6 inches from the glans in “macro mode.” It was ensured that the scale was kept on the same plane as the tissue being measured. For a few patients in Group B, images in two planes (one for meatus and the other for the ventral surface of glans) were required for measurement of the meatus and VGL if they were found to be visible in different planes. The exact dimensions were measured using “Image J” (version 1.51j8) software. The use of this software enabled zooming (32:1) of the digital image, thereby improving the accuracy of the measurements. For Group B patients, measurements on either side of the midline were considered separately, and their mean was used for computation. Data are being presented as mean, standard deviation, and range. P < 0.05 was regarded as statistically significant. Statistical analysis was performed using GraphPad Prism version 7.00 for Windows, GraphPad Software, La Jolla California USA, www.graphpad.com.
| Results|| |
The mean age of the boys in Groups A and B was 4.26 ± 3.59 (range 0.5–12) and 3.82 ± 2.85 (range 0.7–11) years, respectively. The difference in age between the two groups was not statistically significant [Table 1].
The observed mean values in Group A for VGL-A, M-A, and R-A were 3.05 ± 1.27 (range 1.19–8.09), 4.3 ± 1.23 (range 1.61–7.04), and 0.8 ± 0.45 (range 0.27–2.1) mm, respectively. The observed mean values in Group B for VGL-B, M-B, and R-B were 3.77 ± 0.81 (range 12.41–5.2), 3.27 ± 0.71 (range 2.25–5.34), and 1.17 ± 0.26 (range 0.84–1.86) mm, respectively [Table 1].
The VGL was shorter in normal boys, and difference between VGL-A and VGL-B was statistically significant (P < 0.0001). On the other hand, M was longer in normal boys, and the difference between M-A and M-B was statistically significant (P < 0.0001). The ratio VGL/M was smaller in normal boys, and the comparison between R-A and R-B showed a statistically significant difference (P < 0.0001) [Table 1].
| Discussion|| |
Reconstruction in hypospadiology aims at creating a slit-like meatus at an appropriate location on the glans. Achieving this can be quite challenging as there are no objective criteria to depend on especially in severe hypospadias cases where the glans tissue is featureless. Although various studies have looked into this aspect of the anatomy, they have been mostly done in adult participants , and they may not be of relevance in the pediatric patients. Hutton and Babu  explored this relationship in 75 normal boys and found that the VGL is approximately 0.88 of the meatus size. This finding is not markedly different from our findings where the ratio was found to be 0.8 even though the participants in this study are of different ethnic origin.
The intraoperative decisions for designing the incisions for glansplasty are based on subjective assessment and assumption that the surrogate markers of future limits of the meatus and ventral glans cover are a replica in a hypospadiac glans. Hence, they are used as reference points during surgery to recreate the glans and meatus. To test this assumption, Babu  compared these reference points among hypospadias glans and normal participants as has been done in our study. They found no significant difference between the two groups. In contrast, we found that the future mean meatus length is smaller in hypospadiac glans compared to normal participants (3.27 vs. 4.3 mm, P < 0.0001). We would like to stress here that there are a few finer aspects that need to be taken into account while interpreting the results of that study. In their study, the normal historical controls were of a different ethnicity than study participants (Caucasians and Asians, respectively). This fact can have an impact on the size and measurements of the genitalia.,, In addition, the measurements were made with calipers. Measurements in our study were done with high-resolution magnified images using standard software that has the advantage of being very accurate as well as reproducible.
The mean VGL in our study was 3.05 mm in normal glans and 3.77 mm in hypospadiac glans. This difference was also statistically significant (P < 0.0001). In the study by Babu, there was no difference between the groups. This disparity in findings could be because of the same reasons as outlined previously for meatal length. In addition, it is important to note that the ventral glans closure length was considered as the distance from the posterior limit of future meatus to a point on the urethral plate in the same level as that of the coronal sulcus [Figure 2]. In our understanding, this line does not depict the incision that is made to raise the glans wings for glansplasty. One can also appreciate the fact that that the proximal extent of the ventral glans may not always reach the coronal sulcus in a normal child [Figure 1], Group A] as has been assumed. Hence, it is our belief that this dimension does not depict the true ventral glans closure length that is achieved during glansplasty.
|Figure 2: The distances measured in this study M-B and ventral glans length-B, whereas, in the study by Babu, the length that was considered as ventral glans closure is depicted in white dashed line|
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Our study shows that the anatomical landmarks in hypospadiac glans are not a true replica of a normal glans. Our speculation is that this happens because of the “arrest in development” of the region which did not allow the medial migration and shortening of the ventral glans tissue as would have happened in a normal glans. Based on our findings, a more realistic line of the incision on the glans should be along VGL-B. It is not required to extend it fully to the lateral hillock but adjusting it so that this length is around 0.8 times the meatal length and then the incision is carried downward and parallel to the urethral plate on either side [Figure 3]a. If further extension along VGL-B is required for more extensive mobilization of glans wings to facilitate a loose glans wrap, then it must be ensured that stitches for glansplasty are limited to only that portion to achieve a glansplasty that is 0.8 times the meatus [Figure 3]b and [Figure 3]c.
|Figure 3: (a) The proposed line of incision for raising glansplasty and its length as determined by the length of the future meatus M-B. (b) The above also describes the extension of the line more ventrally and laterally (blue lines) if adequate mobilization of glans wings is not achieved by the previous incision. (c) A completed glansplasty which is 0.8 times the M-B, the rest of the mobilized glans tissue is not approximated in the midline (pink lines)|
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We believe that by giving attention to these relationships, complications such as meatal stenosis and urethrocutaneous fistula should also decrease. By providing a glansplasty wrap of optimum length, the blood supply to the meatus would not be hampered, and the resistance to urine flow across the neourethra would also be more favorable compared to when a longer glansplasty is created. This assumption forms the subject for another study, ethical clearance for which has been applied for.
| Conclusions|| |
Among Indian boys, the visible landmarks on a hypospadiac glans and their disposition are not a true replica as that found in a normal glans. The VGL was 0.8 times of the meatus size in normal male children. In comparison, the equivalent VGL was 1.17 times the equivalent meatus size in the hypospadiac participants. The length of the glansplasty, therefore, must be tailored to achieve the “normal ratio” during the reconstruction of glans.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]