This document discusses the modified Koyanagi technique for single-stage repair of proximal hypospadias. It first reviews the embryology and anatomy related to normal penile development. It then defines hypospadias and discusses its epidemiology, etiology including genetic and endocrine factors, diagnosis through clinical examination and investigations, associated anomalies, and classification systems. The document provides a comprehensive overview of proximal hypospadias and sets the stage for the description of the modified Koyanagi surgical technique.

1. MODIFIED KOYANAGI TECHNIQUE
FOR THE SINGLE-STAGE REPAIR OF
PROXIMAL HYPOSPADIAS
Thesis
Submitted for fulfillment of the Master Degree (M.Sc.) in
GENERAL SURGERY
By
ABOUBAKR OMAR ABDALALEEM HASSAN SAYED AHMED
(M.B, B.Ch MRCSEng)

2. PROF. DR. SHERIF NABHAN
KADDAH
Professor of General Surgery and Pediatric Surgery
Faculty of Medicine, Cairo University
DR. TAMER YASSIN MOHAMMED
Assistant Prof. of General Surgery and Pediatric Surgery
Faculty of Medicine, Cairo University
DR. AYMAN HUSSIEN
ABDELSTTAR
Assistant Prof. of General Surgery and Pediatric Surgery
Faculty of Medicine, Cairo University

3. ‫العالمين‬ ‫رب‬ ‫هلل‬ ‫الحمد‬..................
‫محمد‬ ‫سيدنا‬ ‫على‬ ‫سلم‬ ‫و‬ ‫صلي‬ ‫اللهم‬.......
‫أمي‬ ‫ارحم‬ ‫اللهم‬.............
‫سيئ‬ ‫عن‬ ‫تجاوز‬ ‫و‬ ‫لها‬ ‫اغفر‬ ‫اللهم‬‫ا‬‫تها‬.....
‫الجنة‬ ‫رياض‬ ‫من‬ ‫روضه‬ ‫قبرها‬ ‫اجعل‬ ‫اللهم‬..........
‫القيامة‬ ‫يوم‬ ‫امنة‬ ‫ابعثها‬ ‫اللهم‬...............
‫نبيك‬ ‫حوض‬ ‫على‬ ‫بها‬ ‫اجمعني‬ ‫اللهم‬......
‫االعلى‬ ‫الفردوس‬ ‫ارزقها‬ ‫اللهم‬..............

4. ACKNOWLEDGEMENT
• This work wouldn’t appear without the help of many colleagues .
• Dr shreef Kaddah , Dr Tamer Yassin , DR Ayman Hussein , DR Haitham
Esmet , DR Hamed Seleim , Dr kareem Nawar , Dr Ramy Alkonissey ,
Dr Mostafa Ali , Dr Mohammed Ali ,DR Ahmed Abdalrahman Alsaftey ,
Dr Mohammed metwally , Dr Ahmed Saad , DR Mohammed Essam ,
Mr Khaled Hassan , Mr haggag , Miss Nadia , Miss Omnia.
• To All of them , I say Thank you .

5. Review of literature

6. Review of literature
•Embryology .
•Anatomy .
•Hypospadias .

7. Embryology
• Cloaca .
• External genitalia.

8. cloaca
• The cloaca is an endoderm-lined cavity covered at its ventral
boundary by surface ectoderm.
• During the fourth to the seventh weeks of development, the cloaca
divides into the urogenital sinus anteriorly and the anal canal
posteriorly[11].

9. -Three portions of the urogenital sinus can be distinguished:
- The upper and the largest part is the urinary bladder .
-The next part is a rather narrow canal, the pelvic part of the
urogenital sinus, which in the male give rise to the prostatic and the
membranous part of the urethra.
-The last part is the phallic part of the urogenital sinus it is flattened
from side to side, and as the genital tubercle grows, this part of the
sinus will be pulled ventrally. Development of the phallic part of the
urogenital sinus differs greatly between the two sexes[11].

10. SEX DIFFERENTIATION OF THE EXTERNAL GENITALIA:
• Sex differentiation of the external genitalia occurs between the 7th
and 17th weeks of gestation[12].
• Development of male and female external genitalia begins with the
formation of structures constituting the ambisexual stage that in turn
undergo sex differentiation to generate the male and female forms of
external genitalia, through a hormone-independent process.
• In humans this ambisexual stage of development occurs between
gestational weeks 8 and 12[10

12. The genital tubercle elongates to become the penis in males under the influence of fetal
testicular androgens. In the absence of androgens in females the genital tubercle exhibits
minimal growth in size and becomes the clitoris[10]
A portion of the cloacal folds becomes the urogenital folds, which laterally bound the
urogenital ostium with the labioscrotal folds developing laterally. The labioscrotal folds
fuse in the midline to form the scrotum in males, but remain separate forming the labia
majora in females[10].
As the solid epithelial urethral plate elongates towards the tip of the genital tubercle, it
canalizes to form a groove on the ventral surface of the genital tubercle bounded by
urethral folds in males. These urethral folds fuse in the midline converting the urethral
groove into the penile urethra. Failure of fusion of the penile urethral folds from
embryonic weeks eleven to sixteen results in hypospadias, an abnormal opening of the
urethra proximal to its normal location at the tip of the penis[10].

13. Anatomy

14. Penis
• The human penis is made up of three columns of tissue. Two corpora
cavernosa are located next to each other on the dorsal side and one
corpus spongiosum lies between them on the ventral side[13].
• It has three coverings , tunica albuginea, Buck’s fascia , the areolar
dartos fascia, or Colles’ fascia.
• Buck’s fascia is immediately superficial to the deep dorsal vein of the
penis, the paired dorsal arteries of the penis, and branches of the
dorsal nerves of the penis, all of which directly overlie the tunica.
They extend from the 11 and 1 o’clock positions.

15. Penis
• The skin of the penile shaft is highly elastic .
• Its blood supply is independent of the erectile bodies and is derived
from the external pudendal branches of the femoral vessels . These
vessels enter the base of the penis to run longitudinally in the dartos
fascia as a richly anastomotic network.

16. Hypospadias
•Definition
•Epidemiology
•Etiology
•Diagnosis
•Management
•Outcome Assessment

17. Definition
• Hypospadias, a term derived from the Greek terms hypo (under) and
spadon (rent, fissure) In most cases, hypospadias in the male is
associated with three anomalies of the penis:
• (1) a ventral meatus that may be located anywhere between the
glans and the perineum,
• (2) ventral deviation of the penis (chordee), and
• (3) the dorsal prepuce hood in association with a ventral deficit of
the prepuce.
• The second and third abnormalities are not necessary for the
diagnosis of hypospadias[4].

18. Epidemiology
• Hypospadias is the most common congenital anomaly
of the penis, affecting 0.4–8.2 of 1000 live male
babies[17].

19. Etiology
• It is considered to be a mild form of the 46, XY disorders of sex
development (DSD), In most cases, the degree of hypospadias is
relatively mild and a specific endocrine cause is not sought or is not
found.
• (A) GENETIC FACTOR:
• (B) ENDOCRINOPATHIES:
• (C) ENDOCRINE DISRUPTER:

20. Etiology
• (A) GENETIC FACTOR
• (1)Inheritance: Familial clustering is seen in about 10% of the cases,
and the recurrence risk in the male siblings of an affected patient is
about 15%. Seven percent of the fathers of children with hypospadias
are also affected.
• (2)Syndromes with hypospadias: Nearly 200 syndromes are
associated with hypospadias . Smith-Lemli-Opitz syndrome , WAGR
syndrome (Wilms tumor, Aniridia, Genital anomalies, mental
Retardation), Hand-foot-genital syndrome , Opitz G syndrome , Wolf-
Hirschhorn syndrome , 13q deletion syndrome .

21. Etiology
• (A)GENETIC FACTOR:
• (3)Gene mutation: Murine studies indicating androgen receptor
activity regulates Fgf8, Fgf10, and Fgfr2 involved in urethral
development have led to screening for defects in these candidate
genes in patients with hypospadias. Among cases of nonsyndromic
familial hypospadias variants have been found in FGF8 and FGFR2
not seen in normal controls .
• (4)Environmental action on genes:

22. Etiology
• (B) ENDOCRINOPATHIES: The pivotal role of androgens in normal
penis development suggests endocrinopathies impacting hormone
production or action may underlie hypospadias.
• (C) ENDOCRINE DISRUPTER: Hypospadias in humans has also been
linked to exposure to endocrine disrupting compounds , Exposure of
pregnant women to estrogenic and anti-androgenic endocrine
disrupting com- pounds is associated with hypospadias and reduced
anogenital distance in their male offspring, Several studies have
demonstrated that exposure to phthalates results in decreased
anogenital distance in human males, presumably due to lowered
testosterone

23. Diagnosis
• (A) ANTENATAL.
• (B) POSTNATAL.
• a. Clinical examination:
• b. Symptomatology:
• c. Investigations:
• d. Associated anomalies:
• e. Classification and severity assessment:

24. Diagnosis
• (A) ANTENATAL:
• The main finding of the 2D US in cases of hypospadias is the ventral
or lateral curvature of the penis, associated with its shortening.
• The introduction of 3D US allowed the evaluation of the surface
structures of the fetus in rendering mode, enabling the development
of a new imaging method for evaluation of hypospadias

25. Diagnosis
• (B) POSTNATAL.
• a. Clinical examination:
• hypospadias should be diagnosed shortly after birth.
• However, the description of hypospadias should include the following:
• Position, shape, and width of the orifice.
• Presence of an atretic urethra and division of the corpus spongiosum.
• Appearance of the preputial hood and scrotum.
• Penile size.
• Curvature of the penis on erection .

26. Diagnosis
• b. Symptomatology:
• stenotic meatus, a weak urinary flow can be observed.
• Children with proximal hypospadias with penile curvature might not
be able to void while standing.

27. Diagnosis
• c. Investigations:
• Karyotyping:
• A karyotype may help categorize hypospadias as syndromic .
• It may also detect gonadal DSD, especially when there is also
cryptorchidism.
• The role for karyotyping in isolated hypospadias, even proximal cases,
is unclear
• Radiological studies:
• Imaging can be reserved for screening patients with suspected
syndromic hypospadias or DSD[15].

28. Diagnosis
• d. Associated anomalies:
• Cryptorchidism and Inguinal Hernia:In boys with more proximal
hypospadias, cryptorchidism may occur as frequently as 32%.
• Prostatic Utricle:57% of the patients with perineal hypospadias and 10%
with penoscrotal hypospadias had prostatic utricle enlargement
demonstrated on urethroscopy.
• Disorders of sex development:Overall reported incidence in patients
considered to have a male appearing phenotype ranges from 0% to 30%
and is greater with increasing severity of hypospadias and nonpalpable
testes
• Malformation Syndromes:Hypospadias most often occurs in infants
without additional known medical conditions.

29. Diagnosis
• e. Classification and severity assessment:
• James M. Elmore et al in 2013 invented the GSM scoring system.
• Glans (G) score:
• 1. adequate size; adequate urethral plate, grooved
• 2. Glans small in size; urethral plate narrow, some fibrosis or flat
• 3. Glans good size; healthy urethral plate, deeply grooved
• 4. Glans Glans very small; urethral plate indistinct, very narrow or flat

30. Diagnosis
• Meatus (M) score:
• 1. Glanular
• 2. Coronal Sulcus
• 3. Mid or Distal Shaft
• 4. Proximal shaft, penoscrotal
•

31. Diagnosis
• Shaft (S) score:
• 1. No chordee
• 2. Mild (< 30°) chordee
• 3. Moderate (30 - 60°) chordee
• 4. Severe (> 60°) chordee

32. Diagnosis

33. Management
• The steps of hypospadias correction are the following:
• Assessment;
• Chordae correction;
• Urethroplasty;
• Protective intermediate layer;
• Meatoglanuloplasty;
• Scrotoplasty; and
• Skin cover

34. Management
• proximal hypospadias
• 1.Two-Stage Repair:
• 2. Single-Stage Repairs:
• THE TUBULARIZED INCISED PLATE URETHROPLASTY (TIP)
• THE TRANSVERSE ISLAND FLAP (TIF):
• Original Koyanagi Operative technique:

35. Management

36. Original Koyanagi 1984

37. Catright et al, 1994

38. Catright et al, 1994

39. . Emir et al. 2000

40. . Hayashi et al , 2001

41. Sugita et al.2001

42. Hayshi et al.,2006

43. Koyanagi and its modifications
Year of Author
publication
Sample Country
size
Stenosis Fistula Complicate Success
1. Koyanagi et al. 1984, Japan 70 ptn 26% 21% 47% 53%
2. Catright et al 1994, USA 4 ptn 50% 50% 50%
3. Emir et al. 2000, Turkey 20 ptn 20% 20% 80%
4. Hayahi et al. 2001, Japan 20 ptn 15% 15% 30% 70%
5. Sugita et al. 2001, Japan 151 ptn 2% 13% 17% 83%
6. Hayshi et al. 2006, Japan 12 ptn 8% 8% 92%

44. Patients and methods
• STUDY DESIGN:
• This study was conducted in the general pediatric surgery unit, in Cairo university
specialized pediatric hospital, during the period of March 2014 to March 2015.
Twenty cases with proximal hypospadias were included in our prospective study.
We performed the single stage repair, modified koyanagi technique to all of them.
• Inclusion criteria:
• Children with fresh, proximal hypospadias, severe chordae and good phallus size
for age. Fig [18]
• Exclusion criteria:
• Children with recurrent, second stage proximal hypospadias, small sized phallus
to age, circumcised, no chordae.
•

70. RESULTS
• Age:
Characteristics Patients (n= 20)
Range (minimum-maximum) 1-5
Mean ±S.D 2.83 ± 1.17

71. RESULTS
• Type of hypospadias :
Characteristics Number Percent
Penoscrotal 16 80.0
Perineal 4 20.0

72. RESULTS
• Associated anomaly :
Characteristics Number Percent
Associated anomaly
No
Yes
14
6
70.0
30.0
Type of associated anomaly (n= 6)
Unilateral undescended testicle
Bilateral undescended testicle
Unilateral hernia
Rt. Hernia, Lt undescended testicle
3
1
1
1
15.0
5.0
5.0
5.0

73. RESULTS
• As regarding etiology:
Characteristics Number Percent
Drug usage during pregnancy
Negative
Positive
12
8
60.0
40.0
Consanguinity
Negative
Positive
15
5
75.0
25.0
Pregnancy
Single
Twin
18
2
90.0
10.0

74. RESULTS
• As regarding Androgen prior to surgery:
Characteristics Number Percent
Negative 8 40.0
Positive 12 60.0

75. RESULTS
• As regarding the duration :
Characteristics Patients (n= 20)
Range (minimum-maximum) 1-3
Mean ± SD 1.79 ± 0.66

76. RESULTS
• As regarding the operative duration:
Characteristics Patients (n= 20)
Range (minimum-maximum) 150-300
Mean ± SD 193.5 ± 41.84

77. RESULTS
• As regarding the usage of the second layer:
Characteristics Number Percent
Negative 12 65.0
Positive 7 35.0

78. RESULTS
• As regarding follow up period:
Characteristics Patients (n= 20)
Range (minimum-maximum) 2-12
Mean ± SD 8.15 ± 3.53

79. RESULTS
• As regarding early complication:
Characteristics Number Percent
Bleeding
Negative
Positive
19
1
95.0
5.0
Retention
Negative
Positive
19
1
95.0
5.0
Infection
Negative
Positive
19
1
95.0
5.0
Stenosis
Negative
Positive
17
3
85.0
15.0

80. RESULTS

81. RESULTS
• As regarding late complications:
Characteristics Number Percent
Fistula
Negative
Positive (penoscrotal small)
Positive (penoscrotal large)
16
3
1
80.0
15.0
5.0
Site of meatal recession
Negative
Positive (anterior penile)
Positive (mid penile)
Positive (penoscrotal)
15
2
2
1
75.0
10.0
10.0
5.0
Torsion of the glands
Negative
Positive
19
1
95.0
5.0
Diverticulum
Negative
Positive
19
1
95.0
5.0

82. Fistula

83. Recession of meatus

84. Torsion of meatus & urethral diverticulum

85. RESULTS
• As regarding cases needing redo surgery :
Characteristics Number Percent
Negative 11 55.0
Positive 9 45.0

90. Discussion
• Studies on modified Koyanagi:
Follow upAndrogen preoperativeAssociated anomaliesMean of ageSample sizeCountryYear of publicationAuthor
6 months
(planned)
--2.5 yrs20 ptnJapan2001Hayashi et al
3-36months (range)100%-1.6 yrs11 ptnEgypt2006Elhalaby et al
34months
(mean)
80%16%2.5 yrs31 ptnFrance2009P. Mouriquand et al
3- 97monhs (range)-28%3-9 yrs (range)14 ptnIndia2010Rajendra Nerli et al
3-12months (range)30%-1.3 yrs30 ptnEgypt2010Adham Elsaied et al
4-8 months (range)-25%2.6 yrs20 ptnEgypt2013M. Elkassaby et al
6-42 months (range)--9m-11yrs(range)24 ptnIndia2013Anand Alladi et al
2-12 months (range)60%30%2.8 yrs20 ptnEgypt2015Present study

91. Discussion
• As regarding complication rates :
SuccessComplicationDiverticulumTorsionMeatal recessionFistulaStenosisRetentionInfectionBleedingAuthor
70%30%---15%15%---Hayashi et al
82%18%9%-9%18%----Elhalaby et al
39%61%16%-19%39%16%---P. Mouriquand et al
64%36%7%-7%21%----Rajendra Nerli et al
90%10%--3%7%----Adham Elsaied et al
60%40%-5%10%40%5%-20%5%M. Elkassaby et al
54%46%-4%8%21%12%---Anand Alladi et al
55%45%5%5%25%20%15%5%5%5%present study

92. Conclusion
• Although proximal hypospadias represent 10-15 % of hypospadias, it is very
challenging.
• Hypospadias repair has a long and flat learning curve and requires
patience, experience, and great enthusiasm to achieve acceptable results.
• No single technique is ideal, and pediatric surgeon has to master a variety
of techniques because various patient-related specifics can favor one or
another technique.
• A single staged repair can be safely and effectively performed even in
patients with the most severe proximal hypospadias.
• Modified Koyanagi repair performed to severe hypospadias with chordee
gives a good cosmetic and functional result. Complications rate is low once
the learning curve is crossed.