MODIFIED KOYANAGI TECHNIQUE FOR THE

SINGLE-STAGE REPAIR OF PROXIMAL HYPOSPADIAS

ThesisSubmitted for fulfillment of the Master Degree (M.Sc.) in

GENERAL SURGERYBy

ABOUBAKR OMAR ABDALALEEM HASSAN SAYED AHMED(M.B, B.Ch MRCSEng)

 PROF. DR. SHERIF NABHAN

KADDAHProfessor of General Surgery and Pediatric Surgery

Faculty of Medicine, Cairo University   

DR. TAMER YASSIN MOHAMMEDAssistant 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

 

العالمين .................. رب لله الحمدمحمد ....... سيدنا على سلم و صلي اللهم

أمي ............. ارحم اللهمسيئ عن تجاوز و لها اغفر تها .....االلهم

الجنة .......... رياض من روضه قبرها اجعل اللهمالقيامة ............... يوم امنة ابعثها اللهمنبيك ...... حوض على بها اجمعني اللهم

االعلى .............. الفردوس ارزقها اللهم

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 .

Review of literature

Review of literature

•Embryology .•Anatomy .•Hypospadias .

Embryology

• Cloaca .• External genitalia.

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].

-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].

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

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].

Anatomy

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.

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.

Hypospadias

•Definition• Epidemiology• Etiology•Diagnosis•Management•Outcome Assessment

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].

Epidemiology•Hypospadias is the most common congenital anomaly

of the penis, affecting 0.4–8.2 of 1000 live male babies[17].

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:

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 .

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:

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

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

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

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 .

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.

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].

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.

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

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

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

Diagnosis

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

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:

Management

Original Koyanagi 1984

Catright et al, 1994

Catright et al, 1994

. Emir et al. 2000

. Hayashi et al , 2001

Sugita et al.2001

Hayshi et al.,2006

Koyanagi and its modifications

Year of Author

publicationSample Country

sizeStenosis

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%

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.•

RESULTS

• Age:Characteristics Patients (n= 20)

Range (minimum-maximum) 1-5

Mean ±S.D 2.83 ± 1.17

RESULTS• Type of hypospadias :

Characteristics Number PercentPenoscrotal 16 80.0

Perineal 4 20.0

RESULTS• Associated anomaly :

Characteristics Number Percent

Associated anomalyNoYes

146

70.030.0

Type of associated anomaly (n= 6)Unilateral undescended testicleBilateral undescended testicle

Unilateral herniaRt. Hernia, Lt undescended testicle

3111

15.05.05.05.0

RESULTS• As regarding etiology:

Characteristics Number Percent

Drug usage during pregnancyNegativePositive

128

60.040.0

ConsanguinityNegativePositive

155

75.025.0

PregnancySingleTwin

182

90.010.0

RESULTS• As regarding Androgen prior to surgery:

Characteristics Number PercentNegative 8 40.0Positive 12 60.0

RESULTS• As regarding the duration :

Characteristics Patients (n= 20)Range (minimum-maximum) 1-3

Mean ± SD 1.79 ± 0.66

RESULTS• As regarding the operative duration:

Characteristics Patients (n= 20)Range (minimum-maximum) 150-300

Mean ± SD 193.5 ± 41.84

RESULTS• As regarding the usage of the second layer:

Characteristics Number PercentNegative 12 65.0Positive 7 35.0

RESULTS• As regarding follow up period:

Characteristics Patients (n= 20)Range (minimum-maximum) 2-12

Mean ± SD 8.15 ± 3.53

RESULTS• As regarding early complication:

Characteristics Number PercentBleeding

NegativePositive

191

95.05.0

RetentionNegativePositive

191

95.05.0

InfectionNegativePositive

191

95.05.0

StenosisNegativePositive

173

85.015.0

RESULTS

RESULTS• As regarding late complications:

Characteristics Number Percent

FistulaNegative

Positive (penoscrotal small)Positive (penoscrotal large)

1631

80.015.05.0

Site of meatal recessionNegative

Positive (anterior penile)Positive (mid penile)

Positive (penoscrotal)

15221

75.010.010.05.0

Torsion of the glandsNegativePositive

191

95.05.0

DiverticulumNegativePositive

191

95.05.0

Fistula

Recession of meatus

Torsion of meatus & urethral diverticulum

RESULTS• As regarding cases needing redo surgery :

Characteristics Number PercentNegative 11 55.0Positive 9 45.0

Discussion• Studies on modified Koyanagi:

Follow up Androgen preoperative Associated anomalies Mean of age Sample size Country Year of publication Author

6 months(planned) - - 2.5 yrs 20 ptn Japan 2001 Hayashi et al

3-36months (range) 100% - 1.6 yrs 11 ptn Egypt 2006 Elhalaby et al

34months(mean) 80% 16% 2.5 yrs 31 ptn France 2009 P. Mouriquand et al

3- 97monhs (range) - 28% 3-9 yrs (range) 14 ptn India 2010 Rajendra Nerli et al

3-12months (range) 30% - 1.3 yrs 30 ptn Egypt 2010 Adham Elsaied et al

4-8 months (range) - 25% 2.6 yrs 20 ptn Egypt 2013 M. Elkassaby et al

6-42 months (range) - - 9m-11yrs(range) 24 ptn India 2013 Anand Alladi et al

2-12 months (range) 60% 30% 2.8 yrs 20 ptn Egypt 2015 Present study

Discussion• As regarding complication rates :

Success Complication Diverticulum Torsion Meatal recession Fistula Stenosis Retention Infection Bleeding Author

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

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.