Endometrial ablation

Question 1

Indication

Answer 1

AUB refractory to medical treatment

Question 2

Contraindication

Answer 2

Absolute: Family not yet complete

Relative: fixed retroverted uterus (may result in adhesion of bowel to posterior uterus (e.g. severe endometriosis or PID))

Question 3

Mechanism

Answer 3

Complete destruction of the endometrium down to the basal regenerative layer, resulting in fibrosis of the uterine cavity and amenorrhoea

Question 4

Examples of first generation ablation

Answer 4

Laser ablation
Endometrial loop resection using electrodiathermy
Rollerball electrodiathermy ablation

Question 5

Examples of second generation ablation

Answer 5

Thermal balloon ablation
Microwave endometrial ablation
Impedance controlled bipolar radiofrequency ablation

Question 6

Advantages/disadvantages of 2nd generation ablation c.f. 1st generation

Answer 6

Advantages:
Shorter operating time
Fewer serious complications (e.g. fluid overload, perforation, cervical laceration)

Disadvantages:
Higher equipment failure rate
Not suitable if submucosal fibroid >3cm or cavity <4cm or >12cm

Question 7

Efficacy

Answer 7

Short term patient satisfaction 80%
Complete amenorrhoea in 30-40%
Post-procedural hysterectomy rate 27% in 4 years

Question 8

Prerequisite

Answer 8

Family complete
US assessment of myometrial thickness (to reduce risk of perforation and thermal damage to nearby structures, especially in previous CS or small thin uterus)

Question 9

Compared with hysterectomy:

Answer 9

Lower risk of:
- Sepsis
- Pyrexia
- Blood transfusion
Faster recovery
Less effective in reducing blood loss/pain

Question 10

Outline the steps to performing a Novasure endometrial ablation

Answer 10

• Perform hysteroscopy, check cavity adequate for procedure.
• Measure cervical length (I do it visually while withdrawing the hysteroscope) and uterine length.
• Dilate cervix to Hegar 8
• Perform endometrial sampling
• Controller set-up
  
  • Squeeze handles outside patient to locked position and width dial >/=4cm
  • Unlock device (press lock/release button), pull back device handle to completely retract device within external sheath
  • Set the device to the uterine cavity sounding length (enter value into controller)
• Preparing device
  
  • Slide where cervical collar all the way back on the sheath using thumb tab.
  • Hold front handle, insert device trans-cervically in line with axis of the uterus until distal end reaches fundus
  • Slowly squeeze handles until point of increased resistance without locking device (width ~0.5cm)
  • Continue slowly squeezing handles together whilst gently moving device 0.5cm to and from fundus and rotating clockwise/anti-clockwise 45 degrees until handles lock
  • Once locked gently move device using anterior/posterior and lateral movements
  • To complete placement, pull back device until width value reduces by 0.2-0.5cm
  • Then move device gently back to the fundus —> width dial must be >2.5cm
  • Key width value into controller
  • Slide white cervical collar forward using thumb tab to create tight seal around cervix
• Using device
  
  • Vacuum pre-check
  • Cavity integrity procedure: step of foot pedal once, flashing green light (50mmHg of pressure for 4 seconds “intact cavity” —> solid green light)
  • Press enable button
  • Tap foot pedal once to start ablation (~90 seconds)
  • Once complete - will switch off automatically
• Removing device
  
  • slide back white cervical collar
  • unlock handles (press button)
  • Hold front handle stationary, pull back on rear handle to restrict device into sheath and remove device
• Repeat hysteroscopy to confirm success