GYN 2

• Arterial supply to the pelvis

  • Anterior division of internal iliac artery
  • Ovarian artery
  • Superior rectal artery

  
• Internal iliac artery

  One of the bifurcations of the common iliac artery, measures about 2 cm, ureter lies anteriorly and the internal iliac vein posteriorly, soon divides into anterior and posterior divisions, only the anterior division supplies the pelvic viscera

  
• Uterine artery


  1. Arises from internal iliac artery or in common with obliterated umbilical artery

  2. Runs downwards and forwards along lateral pelvic wall until it reaches base of broad ligament, then turns medially and crosses ureter anteriorly

  3. Runs upwards and takes a spiral course along lateral uterine wall between layers of broad ligament

  4. Ultimately anastomoses end on with tubal branch of ovarian artery in mesosalpinx

  
• Branches of uterine artery

  • Ureteric
  • Descending cervical
  • Circular artery to the cervix
  • Segmental arcuate arteries
  • Fundal branch
  • Twigs to round ligament
  • Tubal branch
  • Ovarian anastomotic branch

  
• Vaginal artery


  Arises from uterine artery or directly from anterior division of internal iliac artery, runs down along lateral wall of vagina, sends off numerous transverse branches anteriorly and posteriorly which anastomose to form azygos arteries of the vagina
• Arteries contributing to azygos arteries of the vagina

  • Descending cervical
  • Circular artery to the cervix
  • Inferior vesical
  • Internal pudendal

  
• Arteries supplying the pelvic organs

  • Vesical arteries
  • Middle rectal
  • Internal pudendal artery

  
• Ovarian artery


  Arises from front of aorta, enters pelvic cavity after crossing external iliac vessels, runs medially along infundibulopelvic ligament to enter mesovarium, breaks up into numerous branches to supply the ovary
• Branches of ovarian artery

  • Ureter
  • Uterine tube
  • Round ligament
  • Uterine anastomotic

  
• Superior rectal artery


  Continuation of inferior mesenteric artery, descends down to base of pelvic mesocolon and divides into two branches which course down on either side of the rectum to supply it

  
• Peculiarities of pelvic veins

  • Tendency to form plexuses
  • Plexuses anastomose freely with each other
  • Veins may not follow the course of the artery
  • No valves
• Ovarian veins


  Begin from pampiniform plexus in broad ligament, ascend along ovarian artery, higher up become one vein which drains into left renal vein on left side and inferior vena cava on right side

  
• Venous drainage of pelvic organs

  • Uterus, vagina and bladder - into internal iliac vein
  • Rectum - superior rectal vein into inferior mesenteric vein, middle and inferior rectal veins into internal pudendal vein and then internal iliac vein

  
• Free anastomosis between superior rectal veins of portal system and middle/inferior rectal veins of systemic circulation explains liver metastases from genital organs

  
• Uterine veins communicate with vaginal plexus, accounting for vaginal metastases in endometrial carcinoma or choriocarcinoma

  
• Free communication between pelvic plexuses and sacral/lumbar vertebral venous plexus explains vertebral and intracranial metastases bypassing the lungs
• Groups of pelvic lymph nodes

  • Inguinal nodes (superficial and deep)
  • Parametrial node
  • Internal iliac nodes
  • External iliac nodes
  • Common iliac nodes
  • Sacral group
  • Subaortic and aortic nodes

  
• Lymphatic drainage of uterine corpus

  1. Intrinsic plexus - basal layer of endometrium and subserosal layer, lymphatics from basal layer run through myometrium to reach subserosal plexus

  2. Extrinsic drainage - from fundus and adjoining body to superior lumbar nodes, from cornu along round ligament to superficial inguinal nodes, rest of body to external iliac group, adjacent to cervix into cervical lymphatics

  
• Primary lymph node groups draining the cervix

  • Parametrial group
  • Internal iliac group
  • Obturator group
  • External iliac - anterior and medial group
  • Sacral group

  
• Lymphatics from primary groups drain into common iliac nodes
• Intrinsic plexus


  Two plexuses: (1) Basal layer of the endometrium and (2) Subserosal layer
• Lymphatics from the basal layer

  Run through the myometrium in close relation to the blood vessels to reach the subserosal plexus

  
• Extrinsic drainage of lymphatics from the uterus

  • From the fundus and the adjoining part of the body → along ovarian lymphatics → superior lumbar (para-aortic) group of nodes
  • From the cornu → along the round ligament → superficial inguinal (horizontal group)
  • Rest of the body of uterus → external iliac group
  • Adjacent to cervix → into cervical lymphatics

  
• Primary groups of lymph nodes that the lymphatics from the cervix drain into

  • Parametrial group—inconsistent
  • Internal iliac group
  • Obturator group
  • External iliac—anterior and medial group
  • Sacral group

  
• Secondary group of lymph nodes

  The lymphatics from all the primary groups drain into common iliac and superior lumbar group

  
• Lymphatics of the fallopian tube and ovary

  The intrinsic plexuses of the fallopian tube are situated in the mucosal and subperitoneal layers. The afferents from these plexuses pass up along with ovarian lymphatics to superior lumbar group. There is free anastomosis between the ovarian lymphatics of each side across the uterosacral ligament or via the subperitoneal lymphatic plexus of the fundus of the uterus.

  
• Lymphatic drainage of the vagina

  • Upper two-thirds drain into the nodes like those of the cervix (external iliac, common iliac, internal iliac and obturator nodes)
  • Lower one-third drains into superficial inguinal and at times external iliac nodes
  • The posterior wall lymphatics anastomose with the rectal lymphatics and drain to the rectal nodes, inferior gluteal and sacral nodes

  
• Lymphatics of the vulva


  • There are dense lymphatic plexuses in the dermis of the vulva, which intercommunicate with those of subcutaneous tissue
  • The lymphatics of each side freely communicate with each of them
  • The lymphatics hardly cross beyond the labiocrural fold
  • The vulvar lymphatics also anastomose with the lymphatics of the lower-third of the vagina and drain into external iliac nodes
  • Lymphatics from the deep tissues of the vulva accompany the internal pudendal vessels to the internal iliac nodes
  • Superficial inguinal lymph nodes are the primary lymph nodes that act as the sentinel nodes of the vulva. Deep inguinal lymph nodes are secondarily involved. It is unusual to find positive pelvic glands without metastatic disease in the inguinal nodes
  • Gland of Cloquet or Rosenmüller, which is the upper most deep femoral nodes is absent in about 50% of cases
• Lymphatic drainage of the labia majora

  • Anterior half: Lymphatics intercommunicate with the opposite side in the region of mons veneris → superficial inguinal nodes
  • Posterior half: Drains into → superficial inguinal → deep inguinal → external iliac

  
• Lymphatic drainage of the labia minora and prepuce of clitoris


  • Intercommunicating with the lymphatics of the opposite side in the vestibule and drains into superficial inguinal nodes

  
• Lymphatic drainage of the glans of clitoris


  Drains directly into the deep inguinal and external iliac nodes

  
• Lymphatic drainage of Bartholin's glands

  The lymphatics drain into superficial inguinal and anorectal nodes

  
• Node of Cloquet


  It was previously thought to be the main relay node through which the efferents from the superficial inguinal nodes pass to the external iliac nodes. Recent study shows its insignificant involvement in vulvar malignancy, and thus, it is not considered to be the relay node. The efferents from the superficial inguinal may reach the external iliac group bypassing the node of Cloquet.
• Lymphatic drainage of the bladder and urethra

  • Bladder: The lymphatics drain into hypogastric group of glands → external iliac
  • Urethra: Upper half drains like that of bladder; lower half drains into superficial inguinal node

  
• Somatic nerves supplying the pelvic organs

  • Pudendal nerve—S2, S3, S4
  • Ilioinguinal nerve—L1, L2
  • Genital branch of genitofemoral nerve—L1, L2
  • Posterior cutaneous nerve of thigh

  
• Pudendal nerve


  The sensory component supplies the skin of the vulva, external urethral meatus, clitoris, perineum, and lower vagina. The motor fibers supply all the voluntary muscles of the perineal body, levator ani and sphincter ani externus. Levator ani, in addition, receives direct supply from S3 and S4 roots.

  
• Nerve supply to the anterior and posterior parts of the vulva

  • Anterior half: Ilioinguinal and genital branch of genitofemoral nerves
  • Posterior part: Posterior cutaneous nerve of thigh

  
• Autonomic nerve supply to the pelvic organs

  • Sympathetic: Motor fibers arise from T5 and T6, sensory fibers from T10 to L1
  • Parasympathetic: Nervi erigentes from S2, S3, and S4

  
• Sympathetic nerve supply


  The fibers from the preaortic plexus of the sympathetic system are continuous with those of the superior hypogastric plexus. This plexus lies in front of 5th lumbar vertebra and more often wrongly called presacral nerve. While passing over the bifurcation of aorta, it divides into right and left hypogastric nerves. The hypogastric nerve joins the pelvic parasympathetic nerve of the corresponding side and forms the pelvic plexus (right and left) or inferior hypogastric plexus or Frankenhauser plexus.

  
• Parasympathetic nerve supply


  The parasympathetic fibers (nervi erigentes) are derived from the S2, S3, and S4 nerves and join the hypogastric nerve of the corresponding side to form pelvic plexus. The fibers are mainly sensory to the cervix.