Transcript Instrumentation - unmfamilyplanning

Hysteroscopy: General
knowledge overview
4th year Curriculum.
Objective
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Cover basic instrumentation necessary to
assemble and operate a hysteroscope
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Understand the concepts and concerns regarding
uterine cavity visualization
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Uterine access and distention media
Understand how to use various energy modalities
in operative hysteroscopy
Basic hysteroscopic instrumentation.
Telescopic Optical Characteristics
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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
Field of View
Angle of lens to
central axis of
scope
Degree of
field of view
Orient Post, Then Rotate to Target
V
P
V
P
P
V
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.
Hysteroscopic Sheath Continuous Flow
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Bipartite design: Inner
and outer sheaths
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Independent inflow &
outflow channels for distension media
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Inflow through inner channel
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(always closet to eye piece)
Outflow through outer sheath
Able to proactively flush the uterine cavity
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Maintain a clear field of vision
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
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Uterine Access
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Preoperative preparation of the cervix
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Slow, gentle insertion of dilators
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Pharmacologic-misoprostol
Mechanical-laminaria
Avoid forceful entry
Introduction and advancement of
hysteroscope under direct vision
 Advance only during unobstructed panoramic
view
How to Dilate the Cervix
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MUST do bimanual exam first to assess
uterine size, version and position
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KNOW outside diameter of hysteroscopic
sheath – take all dilators larger than that
diameter OFF THE TABLE
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DO NOT over-dilate: fluid will leak around
scope and lose distention
Complications to Hinder Uterine
Access
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Cervical stenosis
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Acutely flexed uterus
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Lower segment myoma
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Intrauterine adhesions
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Uterine anomaly
Distention media Goals
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Maximize vision
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Minimize intravasation
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Create cavity by overcoming myometrial resistance
Good inflow and outflow to flush out debris that
might impede visualization
Provide for a safe procedure
Allow for surgeon to effectively operate.
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Allow electrosurgery to proceed if indicated
Factors Influencing Distention Media inflow
• Resistance of uterine cavity to distention
•Typically requires between 60-70 mmHg to distend cavity
• Diameter and patency of inflow channels
• Viscosity of distention medium
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
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.
It is the surgeons responsibility to constantly monitor
fluid deficits prevent excessive intravasation.
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Fluid deficit of 750cc (Nonelectrolyte) or 1500
(normal saline) should signal the impending
need to complete the case
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For deficits of 1500cc of non-electrolyte or 2500
cc normal saline
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Conclude case
Assess electrolytes
Manage complications
Common Distention media
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Low Viscosity Electrolyte-Containing
Solution for Use With Bipolar Electrosurgery
 0.9% sodium chloride
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Non-Electrolyte, Non-Conductive Solutions for
Monopolar Resectoscopic Surgery
 3% Sorbitol,1.5% Glycine, 5% Mannitol
Absorption of Non-Electrolyte Medium
Morbidity and Mortality
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Hypo-osmolality
Hyponatremia
Cerebral edema
Cardiac
Neuromuscular
Brain stem herniation
Death
What is Electrosurgery?
Application of high frequency alternating current
(AC)
Creating secondary thermal tissue effects
Electrosurgical Outputs - Waveforms Variations of current & voltage in relation to time
The Effects of Peak Voltage on Thermal Spread
during Electrosurgery
Deep penetration
Minimal spread
Superficial
penetration
Wide spread
Conventional Monopolar Electrosurgery
requires non-conductive media
and adequate current density
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.
Current flows through
the tissue
Non-conductive media Ω = ∞
Tissue Impedance = 100 Ω
Tissue
Conventional Monopolar Electrosurgery
- In Normal Saline If the solution is ionic then the electrical
current disperses throughout the
solution and doesn't concentrate
at the tissue.
Saline Impedance = 25 
Tissue Impedance = 100 
Tissue
Current flows
through saline
following path of
least resistance to
return electrode
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
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