Glans–urethral meatus–shaft score and penile parameters as preoperative assessment tools for hypospadias surgery outcome

Abstract
Background
Our prospective study aims to assess if penile parameters and GMS score can predict the postoperative outcome of patients with hypospadias repaired with the TIP technique.

Methods
This prospective study included patients (6 months–11 years old) with coronal, distal or mid penile hypospadias who underwent Tubularized incised plate (TIP) urethroplasty technique from 2015 to 2017. All patients were assessed preoperatively using GMS score. GMS score included a scale for each component, with the more unfavorable characteristics assigned higher scores. Penile length, urethral plate length, and penoscrotal length were measured using a ruler. Glans width was measured by using a caliper ruler. Demographics and complications were assessed within 3 months of the procedure.

Results
There was a statistically significant difference between complicated and non-complicated patients regarding GMS score, glans width, penoscrotal length, penile length, and urethral plate length/penile length ratio. According to the ROC curve, the cutoff values for GMS score, glans width and penoscrotal length were 6, 14 mm and 5 cm, respectively. The area under the ROC curve for penile length and for urethral plate/penile length ratio was poor and so we could not get a specific cutoff value for either parameters. According to Stepwise logistic regression, the GMS score was the only significant independent parameter while controlling all the other factors. Any increase in the GMS score by one unit would increase the risk of complications 3 times.

Conclusion
GMS score and penile parameters are good predictors and complete each other in preoperative assessment for hypospadias patients. Patients with a high GMS score (above 6) have a higher risk of complication and patients with a Glans width of 14 mm or more and a penoscrotal length of 5 cm or more are associated with less risk of complication.