1. Hysteroscopy: General knowledge overview
4th year Curriculum.

2. Objective
Cover basic instrumentation necessary to assemble and operate a hysteroscope
Understand the concepts and concerns regarding uterine cavity visualization
Uterine access and distention media
Understand how to use various energy modalities in operative hysteroscopy

3. Basic hysteroscopic instrumentation.
Telescopic Optical Characteristics
Field of view is the summation of
Degree of field of view of distal lens
Angle of lens to central axis of telescope
Available fields of view
Centered lens = 0o
Offset (fore-oblique) expands
field to12º, 25º, or 30º
Angle of view ALWAYS
opposite the light post
If the outer lens is centered along the axis of the telescope it is referred to as 0o. Rotating a 0o lens over 360o does not change the image. Alternatively, the distal outer lens may be offset (fore-oblique) to the axis of the telescope at 12o, 25o, or 30o, providing a significantly expanded field of view when the lens is rotated. Larger angles of view proportionally sacrifice image illumination. Customarily, the direction of the fore-oblique angle of view is always opposite the axis of the fiber cable post.

4. Angle of lens to central axis of scope
Field of View
Angle of lens to central axis of scope
Degree of field of view
The angle of view of a rigid hysteroscope is always 180 degrees opposite of the light post. In this case, a 25 degree optical lens deflects the visual field to enable the surgeon to examine structures in locations such as the uterine cornua that are not easily visible when the hysteroscope is positioned in the cervix, due to the limited mobility of the scope in the cervical canal.

5. Orient Post, Then Rotate to Target
Foreoblique View V P V
Orientation and directionality during a diagnostic hysteroscopy is driven and maintained by continuously referencing the light post of the hysteroscope. Since the fore-oblique view is always directly opposite the light post, the surgeon uses it to reliably steer the optical view. Emphasizing this central principle by animation, successive images on this slide demonstrate the vital relationship between the light post of the hysteroscope and the fore-oblique view.
The angled lens allows you to view lateral structures without angling the scope.
All you have to do is rotate the scope-when
post (P) is right view (V) is left etc.

6. Hysteroscopic Sheath Continuous Flow
Bipartite design: Inner
and outer sheaths
Independent inflow &
outflow channels for distension media
Inflow through inner channel
(always closet to eye piece)
Outflow through outer sheath
Able to proactively flush the uterine cavity
Maintain a clear field of vision
The continuous flow operative hysteroscopic sheath was invented to overcome the inherent deficiencies of single-channel sheaths. This sheath has two separate channels fitted with stopcocks that independently serve to instill and remove distention media; the inner sheath carries distention medium to the uterine cavity, and a fitted outer sheath evacuates this medium by gravity or intermittent suction via a set of perforations along its distal margin. This allows for continuous flushing and rinsing of the uterine cavity, enabling a clear view of the operative field during all phases of an operative procedure. Equipped with a 3 mm operating channel, the design allows instruments to be accurately placed anywhere within the uterine cavity. More contemporary assemblies are outfitted with intake and outflow ports that swivel and allow the medium to be instilled equally from either side while minimizing the risk of obstructing or dislodging the inflow tubing. Recently, the continuous flow design has been incorporated into simple diagnostic sheaths of larger dimension.

7. Pre-operative assessment
Hysteroscopic cases carry significant and sometimes unique morbidity
A thorough H&P is always indicated
Often procedures need to be interrupted due to fluid concerns so with operative hysteroscopy subjects should be counseled about staged procedures

8. Uterine Access Preoperative preparation of the cervix
Pharmacologic-misoprostol
Mechanical-laminaria
Slow, gentle insertion of dilators
Avoid forceful entry
Introduction and advancement of hysteroscope under direct vision
Advance only during unobstructed panoramic view
The risk for uterine perforation can be reduced by accurate assessment of the cervico-uterine axes, gentle insertion of instruments, minimizing force, and introducing as well as advancing only under conditions of panoramic visual clarity.

9. How to Dilate the Cervix
MUST do bimanual exam first to assess uterine size, version and position
KNOW outside diameter of hysteroscopic sheath – take all dilators larger than that diameter OFF THE TABLE
DO NOT over-dilate: fluid will leak around scope and lose distention

10. Complications to Hinder Uterine Access
Cervical stenosis
Acutely flexed uterus
Lower segment myoma
Intrauterine adhesions
Uterine anomaly
A bimanual examination prior to the procedure is a sine qua non. Failure to perceive the direction of the cervical and uterine axis with acute uterine flexions may be the most common cause of uterine perforation. Uterine perforation is more apt to occur with distortion of cervical os from prior cervical surgery, postmenopausal atrophy, and prior DES exposure. The risk for uterine perforation is amplified when extra force is used to overcome relative obstruction from lower segment myomata or dense intrauterine adhesions, and especially in the midst of a diminished intrauterine volume from significant uterine anomaly.

11. Distention media Goals
Maximize vision
Create cavity by overcoming myometrial resistance
Good inflow and outflow to flush out debris that might impede visualization
Minimize intravasation
Provide for a safe procedure
Allow for surgeon to effectively operate.
Allow electrosurgery to proceed if indicated

12. Factors Influencing Distention Media inflow
Resistance of uterine cavity to distention
Typically requires between mmHg to distend cavity
Diameter and patency of inflow channels
Viscosity of distention medium
Factors limiting the inflow of distention media include the diameter of the tubing and hysteroscope, the diameter and patency of the inflow channels, the length of the inflow tubing, and the viscosity of the distention medium.

13. Factors Influencing Distention Media Outflow
Leakage at cervix
Scope should fit snugly into cervix
Rate of outflow
Can adjust or restrict outflow channel
Peri-transtubal extravasation
Intravasation of distention media into tissue
This is where morbidity can occur
Factors that can directly affect the outflow of distention media include leakage at the cervical junction, the dimensional interface between the inner and outer sheaths of a continuous flow sheath, amount of active suction placed on the outflow tract, the use of ancillary aspiration, transtubal passage into the peritoneal cavity, and intravasation into the vascular network of the uterus.

14. Ways to decrease intravasation
Intrauterine Pressure Ideally 75 mmHg
Use automated devices that provide fixed pressure/variable flow rates for fluid delivery
Increased when intrauterine pressure of distending media is greater then patients mean arterial pressure (MAP)
Be constantly aware of fluid deficit during surgery that is prolonged or opens large vascular channels
Resection of myoma, Endomymoetrial resection, etc.
Excessive intrauterine pressures (>MAP) can be minimized by limiting the height of large 3-liter bags of distention media to no higher than 1 meter above the level of the uterus, by avoiding the use of pressurized cuffs on infusion bags, and by using automated devices that provide fixed pressure/variable flow rates for fluid delivery.

15. For deficits of 1500cc of non-electrolyte or 2500 cc normal saline
It is the surgeons responsibility to constantly monitor fluid deficits prevent excessive intravasation.
Fluid deficit of 750cc (Nonelectrolyte) or (normal saline) should signal the impending need to complete the case
For deficits of 1500cc of non-electrolyte or 2500 cc normal saline
Conclude case
Assess electrolytes
Manage complications
Recommended practices to reduce the risk of intravasation include restricting perioperative intravenous hydration, compulsive monitoring of the fluid deficit, and terminating the case at 1500 cc of non-electrolyte fluid or 2500 cc of normal saline fluid deficit.

16. Common Distention media
Low Viscosity Electrolyte-Containing Solution for Use With Bipolar Electrosurgery
0.9% sodium chloride
Non-Electrolyte, Non-Conductive Solutions for Monopolar Resectoscopic Surgery
3% Sorbitol,1.5% Glycine, 5% Mannitol

17. Morbidity and Mortality
Absorption of Non-Electrolyte Medium
Morbidity and Mortality
Hypo-osmolality
Hyponatremia
Cerebral edema
Cardiac
Neuromuscular
Brain stem herniation
Death
Significant hypo-osmolal hyponatremia is associated with multisystem morbidities including cerebral edema, and cardiac and skeletal muscle dysfunction from alterations of nerve impulses and membrane potentials.

18. What is Electrosurgery?
Application of high frequency alternating current
(AC)
Creating secondary thermal tissue effects

19. Electrosurgical Outputs - Waveforms - Variations of current & voltage in relation to time

20. The Effects of Peak Voltage on Thermal Spread during Electrosurgery
Superficial
penetration
Wide spread
Deep penetration
Minimal spread

21. Contact Desiccation-Coagulation
Low voltage
Gradual desiccation
Deep penetration
High voltage
Rapid desiccation
Superficial penetration

22. Conventional Monopolar Electrosurgery requires non-conductive media and adequate current density
Tissue
Current flows through
the tissue
If the fluid is non-ionic then electrical current cannot flow, so it arcs to the tissue that has ionic components and less resistance allowing the current to flow.
Non-conductive media Ω = ∞
Tissue Impedance = 100 Ω

23. Conventional Monopolar Electrosurgery - In Normal Saline -
Saline Impedance = 25 
Tissue Impedance = 100 
Tissue
Current flows through saline following path of least resistance to return electrode
If the solution is ionic then the electrical
current disperses throughout the
solution and doesn't concentrate
at the tissue.

24. Bipolar Hysteroscopic Electrosurgery
Consolidation of active and return electrodes into single instrument
Current is symmetrically distributed through the tissue between the two electrodes
Power requirements are reduced

25. Summary
A Surgeon should know basic hysteroscopic instrumentation and assembly prior to surgery
Understanding how distention media should be used and monitored will allow for safe hysteroscopic procedures
Understanding the basics of electrosurgery will avoid problems in the OR