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 / @xirurgi_2025 / @xirurgi_2025 - 715 - файл
.pdf
168
https://t.me/medicina_free
Table 6.1 (continued)
system Benets/utility Limitations
Contrastenhanced
Provides real-time
information on
parathyroid gland
perfusion
May help identify and
preserve parathyroid
gland blood supply
Can guide decisionmaking regarding need for
autotransplantation
Helps determine which
patients are at risk for
postoperative
hypocalcemia
Can help determine need
for postoperative labs and
calcium and vitamin D
supplementation
Rapid cycling between
uorescence imaging,
white light, and
uorescence overlay
Limited ability to
distinguish between
thyroid and parathyroid
glands
Limited tissue penetration
Subjective interpretation of
degree of uorescence/
perfusion
ICG contraindicated in
patients with iodine allergy
Requires purchase of
imaging system and dye
Unclear effect on operative
duration
J. Matson et al.
of inadvertently removed glands in the resection specimen that
could then be autotransplanted. Finally, there is an upfront cost to
acquire the imaging system. There is conicting data on the effect
on operative duration and the ability to prevent hypocalcemia, and
no cost-effectiveness studies have been published, so it is unclear
what the overall nancial impact of incorporating this technology
into a thyroid surgery practice would be.
ICG FA has several similar limitations. The penetration is also
limited to only several millimeters, so overlying soft tissue can
obscure the parathyroid glands. There is also rapid enhancement
of the thyroid gland by ICG as it is also a hypervascular organ.
Therefore, ICG FA should not be used to distinguish between the
thyroid and parathyroid glands. Furthermore, current systems
depend on subjective interpretation of uorescence, which limits
standardization and the ability to determine cutoffs associated
6 Use ofFluorescence Guidance inEndocrine Surgery
https://t.me/medicina_free
with postoperative hypocalcemia and hypoparathyroidism.
Quantitative uorescence is not currently integrated into imaging
systems and requires customization of equipment for real-time
visualization or later analysis of videos with appropriate software,
which does not provide immediate feedback to the surgeon. While
the capability for NIR uorescence imaging is being integrated
into newer laparoscopic and robotic imaging systems, purchasing
these newer models requires signicant investment. Additionally,
the greatest utility in thyroid surgery is likely using systems specically designed for open surgery that do not require using the
unwieldy laparoscopic or robotic cameras to visualize the neck
(and which also do not require sterilization of the camera between
cases). ICG dye also presents an added cost, though it is insignicant compared to the overall operative costs. It is also contraindicated in patients with allergies to iodine. Finally, like NIRAF,
there is conicting data on the effect of the technology on duration of the operation. There is undeniably a requirement to wait
for uorescence after administration of the dye, but most studies
have shown this to range from less than a minute to no more than
3min [44, 45]. This may also result in time-savings if it allows
surgeons to proceed with the operation and wound closure without waiting for intraoperative PTH levels or frozen section analysis or avoid unnecessary autotransplantation.
169
Summary andVision forApplication
Based on early results, there has been a good deal of excitement
and numerous publications about the use of uorescence image
guidance in thyroid surgery. While the vast majority of studies are
retrospective, single-institution case series or cohort studies, there
are several large, randomized trials that seem to show superiority
of NIRAF visualization of the parathyroid glands compared to
traditional surgery [31, 32]. ICG FA may provide additional
insight into the perfusion status of identied glands to help guide
autotransplantation and the need for postoperative monitoring and
supplementation. The systematic review by Demarchi etal. summarized 25 studies utilizing either NIRAF or dye-enhanced NIR
170
https://t.me/medicina_free
J. Matson et al.
imaging in thyroid surgery; they concluded that the use of the
technology was feasible and safe and several benets including
improved identication and preservation of the parathyroid glands
as well as early identication of mistakenly resected glands that
might allow autotransplantation [44]. Together, this may result in
reduced postoperative hypoparathyroidism and hypocalcemia.
This is supported by the ndings of Barbieri etal.; the authors
performed a meta-analysis of 13 studies looking at uorescence
imaging in total thyroidectomy and included 1484 operations
[46]. They found that uorescence-guided surgery resulted in
improvements in both short- and medium-term hypocalcemia
rates compared to traditional surgery (8% vs. 15% and 1% vs. 5%,
respectively).
Taking this information into consideration, we believe that
these techniques can be used in complementary fashion for optimal results. In any case, a pre-incision PTH level should be drawn.
The utility of NIRAF seems to primarily be in the early identication and preservation of parathyroid glands and in examining the
resection specimen for missed glands. Therefore, once adequate
exposure of the thyroid gland has been achieved through incision
of the skin, soft tissue, and platysma and retraction of the strap
muscles, the surgical eld should be examined with the use of a
device designed for detection of parathyroid gland autouorescence. The location of identied parathyroid glands should be
noted, and they should be protected while the dissection carefully
continues, periodically reexamining the eld if candidate structures are found. Once the thyroid specimen has been removed, it
may also be examined briey for any missed glands, noting the
limitations of penetration in identifying deeper intrathyroidal
glands.
The previously identied glands should be conrmed, and then
2.5mg of ICG (1 mL of reconstituted solution, 25mg vial with
10 mL of sterile water) should be administered through a
peripheral IV immediately followed by a 10cc ush of normal
saline or lactated ringers by the anesthesia provider while the surgical eld is visualized with an NIR imaging device. The parathyroid glands should uoresce within 30–90 s if they remain
well-vascularized, and the peak intensity of their uorescence as
6 Use ofFluorescence Guidance inEndocrine Surgery
https://t.me/medicina_free
well as the rate of increase in uorescence intensity may provide
evidence for the adequacy of their perfusion. Glands that appear
to be devascularized (minimal or no uorescence) can be incised
with a scalpel and if there is no bleeding can be considered for
autotransplantation. If there are at least two well-vascularized
glands, autotransplantation of any remaining glands is likely
unnecessary. Similarly, in the case of at least two well- vascularized
glands, providers may choose to forego postoperative PTH/calcium monitoring or prophylactic vitamin D and calcium supplementation.
If there is concern that a candidate gland may be a metastatic
lymph node, this structure should be sampled and sent for frozen
section analysis before autotransplantation. Otherwise, frozen
section analysis and rapid PTH assays are not necessary and
should be used at surgeon discretion on a case-by-case basis.
171
Parathyroid Surgery
The utility of uorescence-guided surgery in identifying parathyroid glands and determining their perfusion status may also be
applied to parathyroid surgery. Parathyroid surgery is primarily
performed to prevent complications or alleviate symptoms related
to hypercalcemia secondary to elevated PTH levels (i.e., kidney
stones, fatigue, depression, osteoporosis, and other symptoms).
The most common indication for parathyroidectomy is primary
hyperparathyroidism, or abnormally elevated PTH and calcium
levels, which is usually due to a single hyperfunctional parathyroid
adenoma. Less common causes of primary hyperparathyroidism
are multiple adenomas, diffuse hyperplasia, and parathyroid carcinoma. In patients with single or multiple adenomas, their disease
process can typically be cured and calcium/PTH normalized by
removal of the pathologic gland(s). Patients with diffuse hyperplasia as well as those with secondary (caused by constant stimulation
from low calcium and elevated phosphate levels in renal disease)
or tertiary (hyperparathyroidism from renal disease that persists
after kidney transplant) hyperparathyroidism require subtotal parathyroidectomy, or removal of most parathyroid glands and leaving
172
https://t.me/medicina_free
about 1/2 gland in situ or autotransplanted to a more easily accessible area such as the forearm or sternocleidomastoid. Failure to
remove diseased glands may result in persistent hyperparathyroidism, while leaving or autotransplanting inadequately perfused
glands during subtotal parathyroidectomy could result in hypoparathyroidism and hypocalcemia. Preoperative imaging is most
effective at localizing single adenomas but has far less sensitivity
and specicity for multiple adenomas or diffuse hyperplasia; even
in the case of a single adenoma, however, intraoperative localization may present a challenge [47–50]. Using near-infrared imaging
either to elicit autouorescence of the parathyroid gland or in combination with uorescent dye such as ICG may facilitate localization of the abnormal glands, and the latter may be used to help
determine which gland is most appropriate for preservation/autotransplantation.
J. Matson et al.
Autouorescence
Parathyroid gland autouorescence has been found to be helpful
in identifying parathyroid glands during parathyroid surgery for
various indications as well as during thyroid surgery. Parras etal.
found a signicant difference in autouorescence intensity
between parathyroid and thyroid glands (p=0.00000235) [16].
McWade etal. corroborated this (parathyroid gland autouorescence is between 1.2 and 29 times higher than thyroid autouorescence) and found a sensitivity for intraoperative parathyroid gland
detection of 97% [51]. The clinical signicance of autouorescence in parathyroidectomy is to help identify parathyroid glands
in order to prevent persistent hyperparathyroidism due to a missed
adenoma or insufcient resection in diffuse hyperplasia. Given
current high cure rates at specialist centers (up to 97%), superiority over traditional surgery is difcult to demonstrate [52]. In their
2019 review of NIRAF in thyroid and parathyroid surgery,
DiMarco and Palazzo determined that 902 patients would need to
be included to demonstrate an improvement in persistent hyperparathyroidism from 2% to 0.1% [34]. Thus far, no studies have
been performed looking at that outcome. However, Demarchi
6 Use ofFluorescence Guidance inEndocrine Surgery
https://t.me/medicina_free
et al. recently described a characteristic autouorescent pattern
for parathyroid adenomas (heterogenous uorescence with a
more highly uorescent cap that correlated with normal parathyroid tissue in 74% of specimens); all patients in their study demonstrated cure of their primary hyperparathyroidism [53]. If this
nding is conrmed in larger studies, the characteristic pattern
may permit the use of NIRAF in further distinguishing normal
from abnormal gland(s) and obviating the need to wait for conrmation with a 50% reduction in PTH levels post-resection, as is
the current standard.
173
Fluorescent Dyes
The use of dye-based techniques to help identify the parathyroid
glands has existed for half a century [21]. The combination of dye
administration with NIR uorescence imaging has seen a signicant uptick in interest and use in the last decade. While various
compounds have been explored for his purpose, including methylene blue and aminolevulinic acid, the dye that has been the most
studied is ICG [12, 22, 24, 39].
It has been proposed that ICG FA may be particularly helpful in
identifying abnormal parathyroid glands because of their potential
increased blood ow. The initial case study by Chakedis et al.
demonstrated that ICG FA could effectively assist with localization of a recurrent parathyroid adenoma in redo parathyroidectomy
[54]. Several case series conrmed its utility in reoperative para-
thyroidectomy as well as in initial parathyroid surgery [55–59].
These studies showed superior sensitivity of ICG FA compared to
traditional techniques such as ultrasound or sestamibi, and even
compared to newer imaging modalities such as 4D CT.
When compared to NIRAF, ICG FA can also give insight into
the perfusion status of the parathyroid glands (Fig. 6.5). This is
important in subtotal parathyroidectomy to ensure that an adequately perfused remnant is selected for either preservation or autotransplantation. Studies have demonstrated that ICG FA may be
useful in this regard, as none of the patients in these reported case
series developed hypoparathyroidism [39, 58, 60]. This was one of
174
https://t.me/medicina_free
J. Matson et al.
abc
Fig. 6.5 A representative image of parathyroid adenoma uorescence following injection of ICG and excitement with NIR light. All are from the same
patient and injection of ICG. (a) Parathyroid adenoma (white arrow) under
white light prior to injection of ICG. (b) The adenoma (white arrow) with
computer-generated green overlay after peak uorescence was achieved. (c)
Fluorescence of the adenoma (white arrow) and its feeding vessel (black triangle) seen in grayscale viewing mode. (Figure and caption reproduced from
Matson etal. [45])
the proposed uses for contrast-enhanced NIR uorescence imaging
in parathyroidectomy described by Solórzano etal. in their recent
review of NIR uorescence in endocrine surgery of the neck [12].
Doses of ICG administered for the detection of parathyroid
glands during parathyroidectomy were variable [39]. As little as
2.5mg can be used effectively, and repeat administration of ICG
can still provide adequate uorescence visualization, such as for
bilateral neck exploration, with ICG FA rst performed on one
side of the neck before repeating the procedure on the contralateral
side [39, 45]. The parathyroid glands will typically reach peak
uorescence in less than a minute; the authors’ recently published
study found an average time to initial uorescence of 26.7s and
average time to peak uorescence of 38.0s, with a signicant association between time to uorescence and how quickly the anesthesia provider ushed the IV following injection of the dye [39, 45].
Potential Pitfalls
Like thyroid surgery, both NIRAF and dye-enhanced uorescence
imaging have a potential role in parathyroid surgery. This role is
variable depending on the exact indication for surgery, and the
limitations vary accordingly (Table6.2).
6 Use ofFluorescence Guidance inEndocrine Surgery
https://t.me/medicina_free
parathyroid glands is not signicant
viability
Limited tissue penetration
Potential false positives with metastatic lymph
nodes, brown fat, colloidal thyroid nodules
Requires purchase of imaging system
Limited ability to distinguish between thyroid
and parathyroid glands
Limited tissue penetration
175
Subjective interpretation of degree of
uorescence/perfusion
ICG contraindicated in patients with iodine
allergy
Distinguishes between thyroid and parathyroid glands Does not provide information on perfusion/
Distinguishes between thyroid/parathyroid glands and
surrounding tissues
system Benets/utility Limitations
Autouorescence Does not require any exogenous contrast agent Occasionally, contrast between thyroid and
Table 6.2 Utility and limitations of uorescence guidance during parathyroid surgery
May improve intraoperative identication of parathyroid
glands over traditional surgery
Potential to identify parathyroid adenomas based on
characteristic uorescence pattern in some cases
Potential to reduce rates of persistent hyperparathyroidism Unclear effect on operative duration
Contrast- enhanced Provides real-time information on parathyroid gland
perfusion
May help guide selection of remnant gland for subtotal
parathyroidectomy
May reduce hypoparathyroidism/hypocalcemia after subtotal
parathyroidectomy
May improve localization of parathyroid adenomas over
traditional preoperative imaging techniques
Dosing may be safely repeated for bilateral neck exploration Requires purchase of imaging system and dye
Uptake of ICG is rapid in both normal and pathologic glands Unclear effect on operative duration
Rapid cycling between uorescence imaging, white light,
and uorescence overlay
176
https://t.me/medicina_free
The primary role of NIRAF in parathyroid surgery is in identication of the parathyroid glands, similar to its role in thyroid
surgery. Therefore, some of the potential issues with its use are
the same: the limited depth of penetration (just a couple millimeters) could result in missed glands, potentially causing persistent
hyperparathyroidism and requiring reoperation, or could result in
devascularization of glands that should be preserved, potentially
resulting in hypoparathyroidism and hypocalcemia; the lack of
information about perfusion status could result in selection for
preservation or autotransplantation of a suboptimally perfused
gland and hypocalcemia. In parathyroid surgery, it is also important to be aware of the variable autouorescence of pathologic
parathyroid glands (often less brightly uorescent than normal
glands or heterogenous in enhancement, and sometimes even
hypouorescent compared to surrounding tissues), which is particularly true for secondary hyperparathyroidism and multiple
endocrine neoplasia type (MEN1).
Dye-enhanced NIR uorescence imaging may be used for
either the identication of normal or abnormal parathyroid glands
during parathyroidectomy or for the assessment of perfusion status of the remnant gland in subtotal parathyroidectomy. The limitations are essentially the same as for thyroid surgery: limited
tissue penetration and ability to detect intrathyroidal or other
“buried” glands, inability to differentiate thyroid and parathyroid
tissue, and potentially increased costs and OR time associated
with its use. However, in parathyroid surgery, there may be better
delineation between thyroid and parathyroid tissue since the parathyroid gland being localized is usually hyperplastic and therefore
should theoretically have increased uptake of ICG and greater
relative uorescence.
J. Matson et al.
Summary andVision forApplication
Overall, the data supporting the use of both NIRAF and ICG FA
in parathyroid surgery is limited, with no randomized trials or
meta-analyses supporting its use. There are several case series
that seem to demonstrate superior sensitivity compared to tradi-
6 Use ofFluorescence Guidance inEndocrine Surgery
https://t.me/medicina_free
177
tional methods of preoperative localization and multiple systematic reviews that highlight the potential uses of these technologies.
There remains a need for large cohort studies and randomized
controlled trials to better support widespread adoption of these
techniques.
Because the data is more limited, the optimal use of either or
both NIRAF and ICG FA in parathyroid surgery is unclear. For a
surgeon who already uses one or both technologies in their thyroid operations, they may prefer to continue integrating that technology into their parathyroid operations. However, the authors
believe that ICG FA offers more advantages in parathyroid surgery over autouorescence. First, pathologic parathyroid glands
have variable autouorescence, which may include heterogenous
enhancement or global hypoenhancement [34]. This is particularly true in the diffuse hyperplasia of secondary hyperparathyroidism and multiple endocrine neoplasia type 1 (MEN1). Second,
the use of ICG can provide information on the perfusion status of
the parathyroid glands and guide autotransplantation or subtotal
parathyroidectomy to reduce the risk of postoperative hypoparathyroidism. The following represents our technique.
The beginning of the operation is no different than for thyroid
surgery, beginning with the anesthesia provider drawing a preincision PTH level followed by the surgeon making a transverse
cervical neck incision and carrying the dissection down through
the platysma and retracting the strap muscles. Once the thyroid
gland is identied, it is retracted toward the midline from the presumed site of pathology (based on preoperative imaging) or from
the surgeon’s preferred initial side if addressing 4-gland disease.
Gentle dissection is then performed to attempt to identify the
parathyroid glands on that side without disrupting their blood supply. Particular attention is given to attempting to nd the enlarged
gland in the case of an assumed single adenoma. After identifying
the candidate gland(s), the surgical eld is visualized through the
uorescence imaging system to ensure appropriate image quality.
This may require adjustment of the OR lights away from the surgical eld or dimming of the room lights. 2.5mg of ICG (1mL of
reconstituted solution) is then injected by the anesthesia provider
through a peripheral IV followed immediately by a ush of at
Соседние файлы в папке @xirurgi_2025