Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6023_Библиотеки_им_академика_М_И_Перельмана.pdf
298
15 Combined Phaco/Vitrectomy
15.3.10 Fluid Against Air Exchange
If the shaving is nished, a PFCL x air exchange is performed. Before we perform
this procedure, we have a look at Diagram 15.1, to get a better sense of the situation
in the vitreous cavity. Before the PFCL x air exchange, the vitreous cavity is lled
with PFCL and on top of it is a layer of water. During the PFCL x air exchange,
there is an anterior phase of air, a middle phase of water, and a posterior phase of
PFCL.After the PFCL x air exchange, only air is in the eye, which is then replaced
by gas. Postoperatively, water will accumulate again under the gas phase.
Consequently, the gas does not effectively tamponade the lower pole.
The PFCL x air exchange is certainly the most difcult and most important
maneuver in the whole detachment surgery, mainly because visibility under air is
bad. Therefore, it is essential to understand the characteristics of PFCL and air.
PFCL and air “work” as antagonists. Air exerts a pressure in the eye from peripheral
(anterior) to central (posterior) but PFCL vice versa from posterior to anterior.
PFCL presses most of the subretinal uid from the central pole to the periphery
through the retinal break into the vitreous cavity, but a part of it ows beyond the
break up to the ora serrata, where it cannot be aspirated (“trapped uid”) (Figs.15.7
and 15.8). This “trapped uid” can, however, be removed with air: The air attaches
the retina beginning in the periphery and ending at the central pole and thereby
pushes the “trapped uid” in the direction of the break (Figs.15.12 and 15.13).
15.3.11 Drainage ofSubretinal Fluid
How do we proceed in practice? Before you switch to air, hold the ute tip in the
middle of the break. If necessary, take the scleral depressor to help. If several breaks
are present, start with the most peripherally located break, and then move to the next
more central break (Fig.15.14). Now, the scrub nurse switches the three-way tap
from BSS to air. In the beginning, disturbing air bubbles arise and the view
Intraoperatively Postoperatively
PFCL x air exchange
Before During
BSS Air Gas
BSS
PFCL PFCL
Diagram 15.1 Diagram of the location of uids during the PFCL x air exchange
After
Gas
Aqueous
Bac
instr
15.3 The Surgery Step-by-Step
Fig. 15.12 Sandwich
tamponade with air and
PFCL.Aspirate rst BSS
and then PFCL until the
PFCL meniscus reaches
the posterior edge of
the hole
Fig. 15.13 If the PFCL
has reached the inferior
edge of the retinal break,
then aspirate the subretinal
uid anterior to the retinal
break. Then you can
continue to remove the
residual PFCL
Subretinal fluid
Backflush
instrument
kflush
ument
299
Air
BSS
PFC
Air
PFC
deteriorates. Remain calm and turn the front lens with the BIOM-focus wheel up.
The visibility will gradually improve.
In the beginning the break is covered with PFCL.After a short time, the PFCL is
suctioned to the posterior edge of the break. Now the air presses the subretinal uid
in the direction of the break. The subretinal uid is trapped between anterior located
air and posterior located PFCL, the so-called sandwich tamponade. Now you aspirate the subretinal uid through the break and at the same time the BSS phase
between air and PFCL (Figs.15.12, 15.13, and 15.15).
300
Fig. 15.14 If several
holes are present then start
to remove subretinal uid
from hole 1 and continue
with hole 2 and then 3
15 Combined Phaco/Vitrectomy
1
2
3
Fig. 15.15 Only if the
complete trapped uid is
removed can you continue
with the removal of
PFCL.Otherwise the
trapped uid will ow
toward the posterior pole
and detach the macula
Retinal
PFCL
break
Only when the “trapped uid” and the BSS in the vitreous cavity are completely
aspirated can you continue to aspirate PFCL beyond the posterior edge of the break.
This is very important because the subretinal uid, which you do not aspirate, will
continue to ow beyond the break in the direction of the optic disc.
15.3 The Surgery Step-by-Step
301
If the “trapped uid” is completely removed, you switch with the ute needle
alternately between the PFCL bubble in order to reduce it and the break in order to
aspirate uid here. Try to aspirate without indenting the break. But sometimes you
can only reach the break with the ute needle if you indent it with the scleral depressor. But you should not indent the break itself, but the retina on either side of the
break. By indenting the break, you close it and prevent the aspiration of subretinal
uid. This procedure is usually not easy and requires patience.
The remaining PFCL is aspirated by holding the ute tip directly in front of the
optic disc. Make sure that the PFCL is completely removed and that neither the
retina nor the optic disc are affected.
If after complete removal of PFCL residual subretinal uid remains in the central
pole, then you may either inject PFCL again up to the break and aspirate the uid
or—if it is only a small amount—leave it. The subretinal uid will be absorbed on
the rst postoperative day.
Surgical Pearls No. 83
Air test for detachment: When the retina is completely attached under air, you have
drained the subretinal uid completely. Air presses the entire subretinal uid from
the periphery to the optic disc, where it is easy to spot. This is only partly true for
PFCL because PFCL pushes the subretinal uid from the posterior pole to the
periphery, where the “trapped uid” is hard to detect.
Surgical Pearls No. 84
Active aspiration: In 25G/27G the aspiration of subretinal uid is easier and more
effective with active (than passive) aspiration. If you do not want to use PFCL, e.g.,
because only a focal retinal detachment is present, then you should absolutely aspirate subretinal uid with active aspiration.
Surgical Pearls No. 85
Removal of PFCL: Two pearls for PFCL removal: (1) When using a ute needle
with silicone tip, the risk of retinal or optic disc touch is much lower. (2) If you are
lled vitreous cavity (with a brief water x air exchange), and then completely
remove the residual PFCL/water puddle.
15.3.12 Complete Laser Coagulation (Fig.15.16)
lled eye.
15.3.13 Tamponade
Concerning the use of tamponade, there are signicant differences between vitreoretinal units at national and international level. The trend nowadays is to use SF6 in
a primary detachment and longer-acting gases and silicone oils for redetachments.
not sure whether you aspirated the entire PFCL, instill a little water into the air-
If necessary, complete now the laser therapy around the retinal break in the air-
302
Fig. 15.16 Complete
laser photocoagulation if
necessary
15 Combined Phaco/Vitrectomy
We differentiate between detached breaks and attached breaks. The choice of
tamponade depends only on the detached breaks. If all detached breaks are located
above the 3 o’clock–9 o’clock meridian, we use SF6. If one detached hole is located
below the 3 o’clock–9 o’clock meridian, we use C2F6. If the detached break is
located at 6 o’clock, we would use Densiron 68 or perform episcleral buckling. An
alternative is of course C3F8.
Surgical Pearls No. 86
1. 27G and air tamponade: 27G sclerotomies leak very little. In the case of a supe-
rior detachment with a break between 11 o’clock and 1 o’clock, we use often
only air as tamponade. There is an excellent tamponade present for 7–10days,
and laser treatment is effective after 3–4days.
Why does it matter? Especially professionally active patients will appreciate to
regain their visual acuity after 1week. In comparison, C3F8 makes an eye blind and
the patient earthbound for 2months.
2. Gas tamponade: air against gas exchange
If the retina and the breaks are fully attached, you can ick the BIOM out and
insufate the diluted gas. The gas container is connected to the three-way tap, the
scrub nurse injects the gas, and the surgeon decompresses the globe with use of a
ute instrument. The globe should remain normotensive.
Surgical Pearls No. 87
Gas vs silicone oil: If the retina is attached under air in detachment surgery, then it
will also be attached under gas, but that’s not necessarily the case for silicone oil.
Why? The surface tension pressure of the gas/water interface is the greatest and
therefore is the most effective in closing retinal breaks (70mN/N). So, when the
15.3 The Surgery Step-by-Step
303
retina is attached under air, then it is also attached under gas. The same statement is
not true for silicone oil. Why? Because the surface tension of silicone oil/water with
50mN/N is less than that of air/water. So, when the retina is attached under air, it
might not be attached under silicone oil.
15.3.14 Removal oftheTrocar Cannulas
Finally, the trocars are removed. Remove rst the instrument trocars and at the end
the infusion trocar. In the case of a gas tamponade, add some gas until the globe is
normotensive. No suture is needed for either gas or silicone oil.
15.3.14.1 Postoperative Posture
In the case of macula-off detachment, we recommend 4–6h face-down positioning
in order to push the subfoveal uid away. Then the face is positioned in a way that
the apex of the gas bubble is located on the break.
In the case of macula-on detached, the patient is positioned straight away so that
the apex of the gas bubble presses against the break.
15.3.14.2 Complications
1. Posterior capsular defect
This is a stupid complication during detachment surgery because the tamponade
will press the IOL forwards and gas or silicone oil will ow into the anterior chamber. In the case of a gas tamponade, we would inject air into the anterior chamber to
counterpress, and in the case of a silicone oil tamponade, we would perform an iridectomy and ll the anterior chamber with Healon GV.
2. Slippage
In cases of giant tears, the retina in the area of the break may slip/glide postoperatively toward the posterior pole (slippage). This is associated with the risk of
developing retinal folds postoperatively which, in the worst of cases, may involve
the macula. This phenomenon is caused by inadequate drainage of subretinal uid
during uid-air exchange. To avoid slippage, perform a direct PFCL x silicone oil
exchange.
15.3.14.3 How toRemove Submacular Fluid
An intravitreal gas tamponade in macula off detachments requires the complete
removal of subretinal uid. Otherwise a macular fold may develop.
Small amount of submacular uid can be removed by postoperative face down
posture for 3–6h. But big amounts of submacular uid have an increased risk of
macular folds.
304
15 Combined Phaco/Vitrectomy
Patients with silicone oil tamponade have never macular folds even in case of
submacular uid. A gas tamponade, however, may cause a macular fold because the
gas has a high surface tension pressure and creates a retinal fold when pressing the
submacular fold away. Why? The surface tension pressure of silicone oil is lower
than that of gas.
What to do in case of much residual submacular fluid?
1. Create a posterior retinotomy and aspirate the submacular uid (Fig.15.17).
2. Use a silicone oil tamponade.
Summary Residual submacular uid is a common problem when performing vit-
rectomy for retinal detachment. There are several solutions for this problem. We
recommend the solutions 3 and 4: Posterior retinotomy or silicone oil tamponade.
15.3.14.4 Tips forPFCL Injections
We inject PFCL bimanually; one hand holds the PFCL syringe and the other hand
holds the Charles ute needle. Hold the tip of the PFCL cannula in the middle of the
vitreous cavity, and inject a little bit. If air bubbles escape, then aspirate them at
once with the ute needle. Then start to inject the PFCL at the posterior pole, and
keep the tip of the cannula always in the PFCL bubble in order to prevent small
bubbles (Fig.15.18). These small bubbles will fusion after some time with the large
bubble. Be cautious where the PFCL cannula is aiming to. Aim never toward the
macula or a retinal break (Fig. 15.19). The PFCL bubble becomes bigger and
Fig. 15.17 A central
retinotomy is created to
remove the submacular
uid
15.3 The Surgery Step-by-Step
Fig. 15.18 Work
bimanual. Start with a
small PFCL bubble
BSS
Charless flute
needle
305
PFCL
Fig. 15.19 Retract the
injection needle slowly as
the bubble is growing. But
keep the tip constantly in
the PFCL bubble to
prevent emulsication
BSS
Charless flute
needle
PFCL
bigger; pull the PFCL cannula slowly backwards but the tip remains constantly
inside the bubble (Fig.15.20).
15.3.14.5 Fractionized PFCL Injection
What does fractionized injection of PFCL mean?
The PFCL is not injected at once but in fractions (Fig.15.21). Inject rst PFCL to
the posterior edge of the retinal break. Then continue vitrectomy. Inject then PFCL
up to the ora serrata. Continue with vitrectomy. Fractionized PFCL injection helps
to drain subretinal uid, stabilize the retina, and remove the vitreous base.
306
ab
cd
15 Combined Phaco/Vitrectomy
Fig. 15.20 Do not inject
the PFCL toward the
macula or a retinal break
Residual vitreous
BSS
Charless
flute needle
PFCL
Residual vitreous
Removal vitreous
PFCL
PFCL
Residual vitreous
PFCL
PFCL
Fig. 15.21 (a) Inject PFCL to the inferior edge of the retinal break and remove the vitreous. (b)
Remove the vitreous on height of the retinal break. (c) Inject now PFCL up to the ora serrata. (d)
Remove the vitreous base (shaving)
15.3 The Surgery Step-by-Step
307
15.3.15 FAQ
How do you deal with what type of detachment?
The general recommendations are that in young phakic patients, one should perform a buckling surgery if possible. In old and pseudophakic patients, a PPV is
recommended. In pseudophakia with multiple breaks, we always perform a PPV;
this is often named “primary vitrectomy for retinal detachment.”
There is a strong tendency toward a combined phaco/vitrectomy for RRD in all
phakic patients of 50 years or above. Phacoemulsication greatly facilitates the
trimming of the vitreous base that is necessary in retinal detachment.
Must I change the position of the trocars according to the location of the
detachment?
No. The trocars are always located at the same positions. You can however make
small deviations according to the location of the break, i.e., to reach the break more
easily. For example, if the retinal break is located at 12 o’clock, then place the trocars more toward 3 and 9 o’clock. This way you can reach the 12 o’clock break easier.
What do you do if a macular hole is present?
Always check for the presence of a macular hole. This is present in 0.5% of all retinal detachments and if you don’t consider it, chances are that you will miss it.
Check either during the preoperative examination or during the surgery. This is
important for prognostication and your surgery, as you may be able to perform an
ILM-peeling during the vitrectomy in order to increase the chances of a postoperative hole closure. To correctly identify a macular hole in cases of macula-off, RRD
is difcult as the thinned retina at the fovea may be mistaken for a macular hole by
the inexperienced examiner.
Should I perform an ILM peeling under PFCL?
If the macula is attached, then perform an ILM-peeling in a water-lled eye. If the
macula is detached, then ILM peeling is difcult. Stain rst the ILM and create a
small opening in the ILM.Then inject a small PFCL bubble, search for the small
ILM opening, and peel the ILM.
How do I remove the subretinal fluid in case of a big retinal detachment?
You remove the complete uid with air, PFCL, and a scleral depressor (Fig.15.22).
The anterior subretinal uid is removed with air. The posterior-located subretinal
uid is removed with PFCL.The horizontal-located subretinal uid is removed with
a scleral depressor. Massage the uid toward the retinal break.