Water Immersion Colonoscopy Technique

Water Immersion Colonoscopy Technique

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15.

2 LOOP JUDGMENT METHODS-THE BLIND METHOD AND THE FIXED-POINT METHOD

TWO LOOP JUDMENT METHODS

Basically, there are only two kinds of loops; the alpha loop which can be released with the clockwise rotation or the reversed-alpha loop which can be released with the counterclockwise rotation (refer p52). In the sigmoid colon, the former part of the colon, 80% of the loops formed are the alpha loops and 20% are the reversed-alpha loops, whereas in the transverse colon, the latter part of the colon, loops are 100% the reversed-alpha. Given these facts, it is possible to assume which loop is formed depending on where the scope is, however, for more precise assumption the loop judgment is applied.

There are two ways for judgment: the fixed-point method, in which the vision on the monitor is used, and the blind method, which uses the right's hand's sense.

[POINT] TWO WAYS FOR LOOP JUDGMENT

1) The blind method: judge with the right hand's sense

2) The fixed-point method: judge while watching the monitor screen.

The loop judgments are both applied when the circular loop is minimized. The fixed-point method is usually used, but when the view is not good enough due to the poor preparation, the blind method is chosen (Chart 15-1).

 

CHART 15-1 FLOW CHART OF LOOP JUDGMENT

 

LOOP JUDGMENT WITH THE BLIND METHOD

Withdraw the scope to the minimized circle and stop when the scope feels heavy where the circular loop is almost minimized. Then twist the scope about 30 degrees in both directions. The direction in which the scope feels lighter is the right direction to release the loop, so twist the scope 90 degrees in that direction and withdraw and twist 90 more degrees simultaneously. This is called the blind method. It is mainly used when the fixed-point method is not readily available due to poor preparation and the like.

 

LOOP JUDMENT WITH THE FIXED-POINT METHOD

You can tell when the circular loop is minimized from heaviness sensed with the right hand. As the fiberscope is withdrawn a little the view on the monitor will turn around a little. That turning direction is the right direction to release the loop. You can practice with the scope on a bed.

 

CHART 15-2 LOOP JUDGMENT WITH THE BLIND METHOD

Withdrawing the scope only a little after the minimized circular loop, the scope itself would turn in one direction. Twist the scope in that direction.

 

CHART 15-3 LOOP JUDMENT WITH THE FIXED-POINT METHOD

If the view of the membrane turns clockwise when the scope is withdrawn, twist the scope clockwise and the loop would be released. This case, for example, is an alpha-loop release.

 

The fixed-point method can be used to release the twist of the colon before its forming a complete loop, therefore this method is frequently applied in the pull method where there is not supposed to be a loop. In short, if the scope is withdrawn and the view on the monitor moves, follow the movement in the same direction to keep the view fixed. Thereby, the intestine can be straightened without the scope's falling (Chart 15-4). This is the most useful technique in the colonoscopy insertion.

 

CHART 15-4 FLOWCHART OF LOOP JUDGMENT BY THE FIXED-POINT METHOD

MOVIE 15-1 TWO METHODS OF LOOP JUDGMENT

There are two ways of loop judgment: the blind method with the sense of the right hand and the fixed-point method with the view on the monitor.

1
00: 00: 00 000 -> 00: 00: 03, 775
Loop judgment

2
00: 00: 03, 776 -> 00: 00: 15, 424
There are two ways to judge whether the loop is α or reverse α.

3
00: 00: 15,425 -> 00: 00: 21, 223
The first one is called the blind method.

4
00: 00: 21,224 -> 00: 00: 24, 855
Begin by pulling straight and make the smallest circle.

5
00: 00: 24,856 -> 00: 00: 35,640
Stop drawing with the smallest circle and swing slightly to the left and right.

6
00: 00: 35,641 -> 00: 00: 41, 714
Turning it to the left makes it heavier.

7
00: 00: 41,749 -> 00: 00: 48,020
Turning it to the right makes it lighter.

8
00: 00: 48,021 -> 00: 00: 51, 688
Lightly turn 90 degrees to the right and 90 degrees to rotate while pulling 30 cm.

9
00: 00: 51,689 -> 00: 00: 56, 209
The principle is the same even when it is reverse α.

10
00: 00: 56,210 -> 00: 01: 01, 731
Make the smallest circle, stop it and turn it to the left, it becomes heavy.

11
00: 01: 01, 732 -> 00: 01: 07, 373
Turning it to the right turns it 90 degrees to the right as it becomes lighter.

12
00: 01: 07, 408 -> 00: 01: 11, 654
Turn the remaining 90 degrees while pulling 30 cm.

13
00: 01: 11, 655 -> 00: 01: 23, 757
Shake about 30 to 45 degrees to the left and right to judge the weight.

14
00: 01: 23, 758 -> 00: 01: 31, 853
In practice, I close my eyes and practice to make a loop judgment just by feeling my hands.

15
00: 01: 31, 854 -> 00: 01: 38, 969
Another method is called fixed point fixing method.

16
00: 01: 38, 970 -> 00: 01: 46, 160
Stop drawing with the smallest circle.

17
00: 01: 46, 161 -> 00: 01: 50, 792
So slightly pulling the screen slightly to the right.

18
00: 01: 50,793 -> 00: 01: 56,056
Turn the scope to the right while following the screen so as not to turn the screen.

19
00: 01: 56,057 -> 00: 02: 06,016
I will explain it with a reverse α loop this time.

20
00: 02: 06,017 -> 00: 02: 13,097
If you pull it slightly with the smallest circle, the scope screen turns to the left.

21
00: 02: 13, 098 -> 00: 02: 19, 312
If you turn the scope to the left so that you can follow it, the loop will be lifted.

22
00: 02: 19, 313 -> 00: 02: 43, 951
Both the α loop and the reverse α loop were originally directly above. The thumb of the right hand comes right downward after being released.

 

MOVIE 15-2 THE FIXED-POINT METHOD

Hook the scope tip on the fold going to left right after traversing the rectum and pull the scope slowly and carefully. If the lumen starts to turn clockwise then follow the movement and use the right turn of scope. When the fold moves to the right of the view, stop pulling the scope and traverse the fold with the right angulation. At this point the strong right angulation is required, so practice the right angulation.

1
00: 00: 00 000 -> 00: 00: 02, 048
It is a movie of fixed point fixing method.

2
00: 00: 02, 177 -> 00: 00: 05, 520
Hang up in a fold visible in the up direction with an up angle,

3
00: 00: 05,555 -> 00: 00: 09,104
As you pull slowly the screen rotates to the right,

4
00: 00: 09, 139 -> 00: 00: 11, 808
Also turn the scope to the right and chase it.

5
00: 00: 11,843 -> 00: 00: 15,472
This makes the intestinal tract straight,

6
00: 00: 15,507 -> 00: 00: 18,240
The tip goes ahead.

 

MOVIE 15-3 GAME OF THE FIXED-POINT METHOD

Press start and the game will start. Choose the right maneuver when the fiber is withdrawn. If the choice is correct, the view will move.

1
00: 00: 00,000 -> 00: 00: 06, 687
This is a video of fixed point fixed game. When you press start

2
00: 00: 06, 687 -> 00: 00: 12, 867
When the screen turns clockwise, it will chase with right rotation.

3
00: 00: 12, 902 -> 00: 00: 17, 346
Also, when moving parallel to the right, chase with right angle.

4
00: 00: 17,381 -> 00: 00: 22, 403
On the contrary, when turning counterclockwise, chase with left rotation,

5
00: 00: 22,438 -> 00: 00: 26, 641
When moving parallel to the left, chase with left angle.

6
00: 00: 26,676 -> 00: 00: 30,999
Screen preferably using rotation and angle

7
00: 00: 30,999 -> 00: 00: 38,034
It is fixed point fixing method to fix and pull so as not to move.