Anatomy of Surgical Incisions for O&G Flashcards
What common O&G surgical incisions are there?
Lower segment Caesarean section (LSCS)
Laparotomy
Laparoscopy
Abdominal (and vaginal) hysterectomy
What is a laparotomy?
A vertical midline incision
What are other names for a lower segment Caesarean section (LSCS)?
Suprapubic / pfaffenstiel / “bikini-line” incision
LSCS, abdominal hysterectomy
Label this diagram
Describe where the external obliques attach
Attach between lower ribs and iliac crest, pubic tubercle and linea alba
Fibres run in same direction as external intercostals
Label this
Where do the internal obliques attach?
Attach between lower ribs, thoracolumbar fascia, iliac crest and linea alba
Linea alba
Fibres run in same direction as internal intercostals
Label this
Describe where the transverses abdominis attaches
Attach between lower ribs, thoracolumbar fascia, iliac crest and linea alba
Linea alba
Describe the tendinous intersections of rectus abdominis
Divide each rectus abdominis
3 or 4 smaller muscles
Describe the linea alba. Where does the linea alba run?
Formed by the interweaving of the muscle aponeuroses
Runs from the diploid process to the pubic symphysis
Describe what the rectus sheath is and where it is
Immediately deep to superficial fascia
Combined aponeuroses of anterolateral abdominal wall muscles
Surrounds rectus abdominis muscles
When undertaking a suprapubic incision, i.e. LSCS, where will rectus sheath be incised?
Anteriorly
Label this diagram
Describe nerve supply to anterolatal abdominal wall
Enter from lateral direction
7-11th intercostal nerves (become thorax-abdominal nerves)
Subcostal (T12)
Iliohypogastric (L1)
Ilioinguinal (L1)
Describe blood supply to anterior abdominal wall
Superior epigastric arteries
- Continuation of internal thoracic artery
- Emerges at superior aspect of abdominal wall
Inferior epigastric arteries
- Branch of external iliac artery
- Emerges at inferior aspect of abdominal wall
The superior epigastric arteries are a continuation of?
Internal thoracic artery
The inferior epigastric arteries are a branch of?
External iliac artery
The intercostal and subcostal arteries are a continuation of?
Posterior intercostal arteries
Describe blood supply to the lateral abdominal wall
Intercostal and subcostal arteries
- Continuations of posterior intercostal arteries
- Emerge at lateral aspect
What surface anatomy changes occur during pregnancy?
Describe what precautions should be intake when incising muscle in a O&G surgical incision
Minimise traumatic injury to muscle fibres - incise in same direction as muscle fibre
Avoid damaging nerves - especially motor nerves
Avoid interrupting blood supply
Describe what happens to the rectus muscles in a LSCS
Rectus muscles are not cut
Separated from each other in a lateral direction
What layers are opened when doing an LSCS incision?
Skin + fascia
Anterior rectus sheath
Rectus abdominis
Fascia and peritoneum
Retract bladder
Uterine wall
Amniotic sac
What layers do we stitch closed in a LSCS incision?
Uterine wall with visceral peritoneum
Rectus sheath
Skin
What layers do we open in a laparotomy?
Skin + fascia
Linea alba
Peritoneum
What layers do you stitch closed in a laparotomy?
Peritoneum + linea alba
Fascia skin
Describe blood loss in a midline incision
Relatively bloodless
Increases the chance of wound complications e.g. dehiscence, incisional hernia
Label this diagram
What kind of incision is this?
What kind of incision can you do in a laparoscopy?
A sub-umbilical incision may be all that is required
If a lateral port is required, care must be taken to avoid the inferior epigastric artery
If a lateral port is required in a laparoscopy, what artery must be avoided?
Inferior epigastric artery
To view the pelvic organs in a laparoscopy, the position of the uterus can be manipulated how?
By grasping the cervix with forceps inserted through the vagina
What kind of incisions are these?
The inferior epigastric artery is a branch of?
External iliac artery
Where does the inferior epigastric artery emerge?
Just medial to the deep inguinal ring
Where does inferior epigastric artery pass?
In a supermedial direction posterior to rectus abdominis
Label this
What is an abdominal hysterectomy?
Removal of the uterus via an incision in the abdominal wall
What is a vaginal hysterectomy?
Removal of uterus via the vagina
During hysterectomy, extreme care must be taken to differentiate what?
The ureter from the uterine artery
The ureter passes inferior to the artery (“water under the bridge”)
The ureter will often “vermiculate/wiggle” when touched
