Penile anatomy

Surgical anatomy of Penis with special reference to hypospadias

1. Pe n ile Anat o my Dr. Faheem ul Hassan Andrabi Fellow Pediatric Urology Dr. Vinay Jadhav Assist. Professor Pediatric & Neonatal Surgery

2. Penis A sign of pride and power before which even the veteran surgeons loose both. S. F. Andrabi

3. External anatomy The penis consists of an attached root (radix) a free, pendulous, body (corpus) covered by skin

4. Skin Skin is thin and loose At the corona of the penis it is folded to form the prepuce or foreskin

5. Skin The internal preputial layer is confluent with thin skin of glans the frenulum , passes from the deep surface of the prepuce to the glans

6. Root The root of the penis consists of two crura and the bulb , crura are attached to the pubic arch and bulb to perineal membrane respectively.

7. Root The crura are continuation of corpora cavernosa , and the bulb is the dilated posterior end of the corpus spongiosum.

8. Root

9. Body Body of the penis consists of erectile tissue, the right and left corpora cavernosa and the median corpus spongiosum

10. Corpora cavernosa Form most of the body of the penis. They share a common fibrous envelope, the tunica albuginea (TA) TA forms a septum between corpora which deficient distally The two corpora communicate distally

11. Corpora cavernosa Ventral to corpora is corpus spongiosus dorsally between the corpora is dorsal neurovascular bundle. The corpora end distally within the proximal aspect of the glans penis

12. Corpus spongiosum The corpus spongiosum of the penis is traversed by the urethra It is cylindrical, tapering distally, and surrounded by a tunica albuginea. Near the end of the penis it expands into the glans penis

13. Dartos Fascia A loose areolar subcutaneous tissue, devoid of fat contains the superficial blood vessels, nerves, and lymphatics.

14. Buck’s Fascia The deep fascia penis ( Buck’s ) binds the three bodies together splits ventrally to ensheathe the corpus spongiosum, It is closely adherent to the tunica albuginea . Distally, it is attached to the coronal groove . Proximally, it covers the crura and bulb

15. Fascia of Penis

16. Urethra

17. Suspensory ligaments of penis Fundiform _________ Linea alba Triangular _________ Pubic symphysis

18. Deep Arterial Supply Internal Iliac Artery Internal Pudendal Artery Bulbourethral Artery Cavernous Artery Dorsal Artery

19. Deep Arterial Supply

20. Dorsal Artery of Penis Branches Cortical branches ____ Pierce Tunica Albuginea Circumflex Branches ___ Supply Corpus Spongiosum Frenular artery _____ Supplies Glans

21. Deep Arterial Supply- Bulbourethral artery runs through the deep transverse perineal muscle to the penile bulb It supplies the corpus spongiosum Bulbar urethra bulbourethral gland.

22. Deep Arterial supply- Cavernosal artery Passes through the perineal membrane enters the crus penis on each side runs the length of the corpus cavernosum supplies the erectile tissue

23. Deep arterial supply- Courses of 3 arteries Bulbar a. pierces the urogenital diaphragm and bulbospongiosus muscle supply corpus spongiosus Urethral a. also enters the bulb close to the bulbar.

24. Deep arterial supply- Courses of 3 arteries The cavernosal artery runs along the superomedial aspect of the crus , pierces the tunica albuginea just before the two crura unite, and runs distally in the center of the corpus cavernosum

25. Deep arterial supply- Courses of 3 arteries Dorsal artery runs distally lateral to the deep dorsal median vein and medial to the dorsal nerve

26. Superficial arterial supply Femoral artery Deep EPA Superficial EPA Dorsolateral & ventrolateral Axial arteries

27. Superficial arterial supply

28. Superficial arterial supply

29. Superficial arterial supply Axial branches give off cutaneous branches at the base of the penis to form a subdermal arterial plexus , which extends distally to the prepuce.

30. Superficial arterial supply

31. Superficial arterial supply

32. Superficial arterial supply Behind the corona, the axial arteries send perforating branches through Buck’s fascia to dorsal arteries

33. Superficial arterial supply

34. Superficial arterial supply

35. Prepucial arterial supply the minute axial arteries supplying the outer prepuce layer fold by 360 º to terminate at the corona

36. Propucial arterial supply incision along the coronal sulcus would not damage the arterial supply of the prepuce in any way as the vessels terminate at this site

37. Venous Drainage superficial drainage system Prepuce Skin Subcutaneos tissue Superficial dorsal vein 2 Left Saphenous vein

38. Venous Drainage superficial drainage system

39. Venous Drainage Intermediated venous drainage

40. Venous Drainage Deep venous drainage

41. Lymphatic drainage penile and perineal skin superficial inguinal nodes glans deep inguinal and external iliac nodes. Lymph vessels from the erectile tissue and penile urethra internal iliac lymph nodes

42. Nerve Supply Sympathetic T11–L2 Parasympathetic S2–4

43. Surgical Implications of arterial supply It is necessary to keep intact at least one , and preferably two, of the four branches of the external pudendal artery supplying the penile skin. The dorsolateral pair are the ones usually used for a pedicle. Because the vessels are arranged axially, only longitudinal pedicles can be raised.

44. Surgical Implications of arterial supply Superficial fascia is indivisible , because it contains the blood supply. It can support only one flap, although two flaps could be formed side by side. Closer to the corona prepuce has tenuous blood supply A flap from the shaft will have a better blood supply than one from the prepuce Outer prepuce will have better blood supply than inner preputial surface. This can be an important factor when a flap is to be placed at a scarred site.

45. Key Points The three main abnormalities in Hypospadias are abortive foreskin arrested urethra and Deficient urethral spongiosum

46. Triangular defect Its summit is formed by the proximal division of the corpus spongiosum The lateral sides by the two atretic pillars of spongiosum And the base by the widely open glans .

47. Triangular defect All tissues sitting inside this triangle are under-developed, hypoplastic or dysplastic, although there is no histological consensus to define these concepts

48. Key Points Histological analysis has shown that the urethral plate in hypospadias is well vascularized, with sinusoids of abortive urethral spongiosum, and without scar tissue These features may explain the successful use of incorporating the urethral plate or abortive spongiosum into hypospadias reconstruction

49. tip of corpora cavernosa glans cap (4) the tunica albuginea (5) Buck fascia (8) preputial dartos

50. Key Points There is line of relative avascularity at dorsal midline with rich vascularity on dorsolateral aspects On ventral aspect, ventral penile branch of anterior scrotal artery is not always present.

51. Key Points intraglanular arcade of vessels is protected by the lamina propria of the base of glans fused with the intraglanular extension of Buck fascia

52. Key Points Dorsolateral and dorsomedial branches run at the lateral aspect of shaft in the area between 10- to 8-o’clock and 2- to 4-o’clock positions A rich collateral network is present at the base of glans cap over the tip of corpora cavernosa with anastomosis between terminal branches of superficial dartos vessels & dorsal penile artery

53. Penile anthropometry in North Indian children

54. Thank you Thank you Srinagar; Almond Blossoms [email protected]