Hypospadias repair is a challenging reconstructive procedure with different techniques being currently employed aiming to create a functionally and cosmetically normal penis. Re-evaluation of the already settled techniques with objective assessment of outcomes have a major impact on the evolution of new strategies for creation of a penis that looks normal. The present study objectively compared cosmetic and functional outcomes following a modification of the standard TIP technique (s-TIP) that entails extension of midline incision beyond glanular demarcation (e-TIP) and assessed impact of penile biometrics on the outcomes after both techniques.
In this modification (e-TIP), deep UP midline relaxing incision was done started from within the hypospadiac meatus and to be extended distally to the very tip of the glans then the neourethral tabularization was started from distal to proximal in a way allowing fashioning neomeatus of a suitable calibre located at glans tip. This idea was first described by Jayanthi  in 2003 and applied for 110 boys (5–60 months) with primary hypospadias and a follow-up reached 3.5 years with no complications except fistula in one patient. The authors incorporated glans cushions (glanular tissue adjacent to urethral plate) during urethroplasty which naturally created a wider urethra and no need for performing deep incision of plate in all cases . Ten years later, other authors adopted the concept of extending the UP-midline incision to the very tip of the glans and incorporate the glans cushions in urethroplasty that were deeply dissected from glans wings with deep midline incision . In that study, the technique was performed on 43 patients with primary distal hypospadias cases and the cosmetic outcome was assessed by the hypospadias objective scoring evaluation (HOSE) and the functional outcome by assessment of Q-max and PVR. The study found that the new modification ensured the fashioning of a vertical slit-like neomeatus located at the tip of the glans, competing with the normal anatomy . In contrast, Snodgrass and colleagues emphasized that the relaxing should be limited to the UP as it may create a “shelf” . The same authors in another study proposed that suturing the plate too far distally may induce meatal stenosis while the neomeatus should have a wide oval configuration by allocating the most distal stitch at the mid-glans level to avoid meatal stenosis .
The width of UP is a paramount factor of TIP technique, Holland and Smith found that complications were more prevalent when UP width <8mm. The authors evaluated 48 patients who underwent distal repair, they found 13% stenosis and 55% fistulae when the UP was flat and narrow that was not the situation when the plate was moderately or deeply grooved. The authors concluded that the midline relaxing incision enabled tubularization but did not lead to adequate neourethral calibre when the plate was narrow or flat in order to avoid fistulas or meatal stenosis . Likewise, in a previously mentioned study, the authors found that UP characteristics were significant predictors of success . In contrary, Nguyen and Snodgrass proclaimed that TIP urethroplasty was applicable regardless of initial UP configuration or width when paying attention to technical details leading to achievement of good cosmetic and functional outcomes with few complications .
In the present study, the HOPE score, a photograph-based instrument , was applied for cosmetic evaluation, the score has good reliability when experienced by 13 paediatric urologists . Cosmetic outcome as presented by mean (SD) total HOPE score was significantly higher in e-TIP group compared to s-TIP group (56.9 (3.6) versus 54.2 (3.4); p<0.001). This significant difference was attributed to the shape and position of the neomeatus, which was the objective of the modified technique. Details of HOPE score evaluation are depicted in table 1. In e-TIP, normal vertical slit-like meatus at position 1 (distal glans) was achieved in 38/46 (82.6%), while in 8 patients the meatus was at position 2 (proximal glanular) due to the need to start tabularization slightly lower down in a conical glans. Regarding glans shape, slightly abnormal glans is suggested to be due to excessive glanular wing dissection which happened during glanuloplasty aiming to avoid postoperative glanular dehiscence. In s-TIP technique, normal-like meatus was achieved in 25/48 patients (52.1%); only 11 patients (22.9%) had meatus at position 1 while the rest of the patients had meatus at position 2.
In normal children, external urethral meatus anatomy was investigated by Hutton and Babu , they examined the proportional relationship between the ventral glans closure length and meatal length in normal children. The authors found that mean (SD) vertical meatal length was 5.4 (1) mm, ventral glans closure was 4.7 (1.2) mm, and mean (SD) ventral glans closure was 88% (22%) of the vertical meatal length. They concluded that position and size of the external meatus are constant in normal boys and VGC is equal to or slightly less than ML . In the present study, mean (SD) VGC to ML was 87%(26) for the e-TIP group while it was 46%(12) for the s-TIP group with statistically significant difference (p value <0.001) that was comparable to normality in the e-TIP group.
Functional outcome following TIP repair using uroflowmetry had been investigated in many studies signifying the importance of long-term follow-up of those boys and the obtained results were quite controversial. While some studies claimed that majority of patients exhibited normal flow pattern [14–16], others reported an obstructed flow in a significant proportion of cases [17,18]. In a systematic review addressing the importance of uroflowmetry studies after TIP repair, 11 studies reported obstructive flow in 24.6% of patients (93 / 378) .
In the current study, 28 patients were eligible for uroflowmetry, 12 in e-TIP and 16 in s-TIP group. Uroflow data are depicted in table 2. Using a nomogram for age matched children , the Qmax was plotted against the voided volume where 4 out of 28 cases (14.3%) had obstructed flow with a Q-max values below the 5th percentile on the nomogram, two in each group, that is below than previously reported in the literature . Qmax values in most cases were between 25th and 50th percentile of the nomogram while Qave values were above the 5th percentile (Figure 3 a, b).
The obtained functional results in the current study are comparable with the findings of a previously mentioned study using the same technique where uroflow data were available for 26 asymptomatic toilet-trained boys. Qmax and Qave tended to cluster below the 50th percentile and 4/26 (15.3%) had a Qmax below the 5th percentile denoting obstructed flow while their Qave was above the 5th percentile on the same nomogram . In a study performed by Snodgrass, the flow rate was low in only one patient out of 17 patients underwent TIP repair and followed up for 45 months . Eassa et al. assessed the repair of 59 boys with distal hypospadias by s-TIP technique found that the uroflow curve pattern postoperatively was bell-shaped in 16 patients, interrupted in eight, slightly flattened in 20 and a plateau in six . The authors used Gaum Nomogram  and found that 36 patients were above the 20th percentile, 9 were below 5th percentile and 6 were in-between, and there was a significant PVR in 9 patients. Regarding postoperative complications, there was insignificant difference between both groups (p = 0.737).
Linear regression analysis was run to investigate preoperative parameters that thought to impact the total HOPE score. It was found that e-TIP and width of UP were significant predictors for total HOPE score. The e-TIP led to increase in total HOPE score by about 2.5 points more than the s-TIP technique, P = 0.001 (Table 3) and the preoperative width of UP was another significant predictor of high score (p-value 0.019).
There are some limitations to the present study, the possibility of subjective misinterpretation of HOPE score by study participants, interindividual variations that led to unintentional errors when measuring TGD and UP width and their impact on reliability of measure. Another limitation is the relatively small number of cases available for uroflow study, which could be due to the relatively young age at operation and short period of follow-up as most children were not old enough to perform uroflow, in addition to absent preoperative uroflow data. Nevertheless, this study enjoys important advantages as it is a randomized prospective study used three objective methods for cosmetic and functional assessment of our results.