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_892_Библиотеки_им_академика_М_И_Перельмана
.pdf
Chapter 12
https://t.me/medicina_free
Microvascular Free Tissue Transfer
inOsteoradionecrosis
andMedication- Related Osteonecrosis
oftheJaws
ArshadKaleem, NeelPatel, JosephGeiger, andRamzeyTursun
Introduction
Osteoradionecrosis of the jaws (ORN) and medication-related osteonecrosis f the
jaws (MRONJ) are two disease processes that pose unique challenges and require
specic considerations in regard to management. These conditions can be managed
by way of nonsurgical (medical) management, more conservative surgical measures, or in cases of advanced disease and aggressive surgical intervention such as
resection and reconstruction using a variety of techniques.
The rst section of this chapter will focus on management of patients with
ORN.This is a much feared complication after radiation therapy in head and neck
cancer, with an incidence ranging from 2 to 37% [1]. There appears to be a
A. Kaleem
Division of Oral and Maxillofacial Surgery, DeWitt Daughtry Family Department of Surgery,
Section of Head and Neck Surgical Oncology and Microvascular Reconstructive Surgery,
Miller School of Medicine/Jackson Health System, University of Miami, Miami, FL, USA
N. Patel (*)
Division of Oral and Maxillofacial Surgery, DeWitt Daughtry Family Department of Surgery,
Head and Neck Surgical Oncology and Microvascular Reconstructive Surgery, Miller School
of Medicine/Jackson Health System, University of Miami, Miami, FL, USA
J. Geiger
Oral and Maxillofacial Surgery, DeWitt Daughtry Family Department of Surgery, Miller
School of Medicine/Jackson Health System, University of Miami, Miami, FL, USA
e-mail: joseph.geigeriii@jhsmiami.org
R. Tursun
Division of Oral and Maxillofacial Surgery, DeWitt Daughtry Family Department of Surgery,
Head and Neck Surgical Oncology and Microvascular Reconstructive Surgery Fellowship,
Miller School of Medicine/Jackson Health System, University of Miami, Miami, FL, USA
© The Author(s), under exclusive license to Springer Nature
Switzerland AG 2023
J. C. Melville et al. (eds.), Advancements and Innovations in OMFS, ENT, and
Facial Plastic Surgery, https://doi.org/10.1007/978-3-031-32099-6_12
223
224
https://t.me/medicina_free
correlation between the development of ORN and the amount of radiation, with
60Gybeing the threshold after which the risk of development of ORN signicantly
increases, particularly in the mandible [2].There is also an incremental increased
risk of complications from ORN associated with greater time from radiation therapy, owing to the continued effect on tissues over time [3]. The most severe cases of
ORN are most often managed surgically with aggressive resection and free ap
reconstruction in order to reconstruct the resultant defects.Effective management
strategies must be employed to successfully treat these patients and involves considerations in all phases of treatment. A thorough preoperative clinical and radiographic examination must be done, appropriate biopsies done for accurate diagnosis,
and risk stratication for potential complications. Intraoperatively, challenges can
present during dissection of the severely brosed neck, as well as handling and
preparation of radiated vessels for reperfusion of aps. Postoperatively complication rates are higher due to wound healing issues and the continued effect of
radiation.
The second focus of this chapter examines the management of advanced MRONJ
with resection and free ap reconstruction and the challenges encountered during
this process. MRONJ was rst reported in 2003 by Marx in 36 patients and is
dened as non-healing bone in craniofacial complex that persists for more than
8weeks in a person who has received a systemic drug known to cause ONJ with no
history of radiation to the jaws [4, 5]. These medications include anti-resorptive and
anti-angiogenic medications such as bisphosphonates and RANK ligand inhibitors.
Similar to ORN, special considerations exist in these patients in the preoperative,
intraoperative, and postoperative phases of treatment. Challenges in accurate disease process delineation, healing issues due to immunosuppression, and the overall
health of the metastatic cancer patient all serve as issues that must be considered.
The goals of resection and reconstruction in ORN and MRONJ patients are
threefold: (1) curative, which involves resection of diseased bone and soft tissue; (2)
restoration of form and function, in terms of articulation, mastication, and swallowing; and (3) esthetic, to obtain a cosmetically acceptable result [6]. In this chapter,
the authors will discuss some of the issues that present in management of these
patients, as well as ways in which to mitigate these problems and avoid potential
pitfalls that can be encountered.
A. Kaleem et al.
Osteoradionecrosis
Management of patients with ORN can be very difcult, with reconstruction of the
hard and soft tissues of the facial skeleton after resection in these patients presenting
some interesting challenges for the reconstructive surgeon. Historically, options
have included reconstruction plates, pedicled soft tissue aps, secondary reconstruction with non-vascularized bone grafts, and more recently, the use of microvascular free tissue transfer. Though it is been a time-honored approach, reconstruction
of these defects using non-vascularized tissue has been shown to result in
12 Microvascular Free Tissue Transfer in Osteoradionecrosis and Medication-Related…
https://t.me/medicina_free
225
inconsistent success rates, varying from 20% to 91%, with complication rates
approaching as high as 81%, secondary to issues such as decreased tissue bed vascularity leading to poor healing and increased rates of infection [7, 8]. The use of
pedicled aps to bring vascularized tissue to the region has helped to alleviate some
of these issues; however in cases of composite bone and soft tissue defects necessitates a multi-stage surgical approach. The advent of composite free tissue transfer
in reconstruction of these defects has served to overcome this and provides a means
by which surgeons can reconstruct these defects in a single-stage surgery (Fig.12.1).
This proves particularly useful in cases of very advanced disease due to high dose
radiation, where treatment often involves extensive resection of both hard and soft
tissues, leaving very large composite defects (Figs.12.2, 12.3, and 12.4). With the
advancement of virtual surgical planning, surgeons are now able to provide accurate
and predictable results in these complex cases with custom hardware and less operating time (Figs.12.5, 12.6, and 12.7). Though free ap reconstruction has revolutionized the management of ORN, it is not without its risks and difculties and has
been shown to be associated with increased rates of complications, including ap
failure rates anywhere from 1.4% to 24% [9–14]. Patients who present with this
complication from radiation therapy display a variety of both anatomic and
Fig. 12.1 Patient presented with ORN of the mandible bilaterally and was treated with en bloc
segmental resection and free bula ap (FFF) reconstruction with immediate dental implant
placement
226
https://t.me/medicina_free
Fig. 12.2 A patient demonstrating extremely advanced ORN of the mandible with necrosis of the
soft tissues of the face
A. Kaleem et al.
Fig. 12.3 Extensive resection of hard and soft tissues of the facial complex in the advanced ORN
patient, with double ap reconstruction using a bula free ap (FFF) and an anterolateral thigh
ap (ALT)
12 Microvascular Free Tissue Transfer in Osteoradionecrosis and Medication-Related…
https://t.me/medicina_free
227
Fig. 12.3 (continued)
physiologic changes that can not only produce intraoperative challenges but can
also result in early and late complications postoperatively after free ap surgery.
Vasculature
One of the primary necessities for free tissue transfer procedures is the availability
of blood vessels of adequate quality and caliber for microvascular anastomosis to
re-vascularize the transplanted tissues. This requires not only the presence of relatively healthy vasculature in the region immediately adjacent to the defect to be
reconstructed but also hinges on meticulous and careful dissection and preparation
of the vessels to ensure optimal anastomosis. In the case of reconstruction of the
facial bones, this usually entails the use of vessels within the neck for this purpose.
In patients who have been treated with radiation therapy for malignant disease,
unfortunately this often results in the cervical tissues receiving large amounts of
radiation, resulting in signicant changes in tissue quality that should be taken into
consideration. The effects of radiation on vessels have been documented via the use
of electron microscopic evaluation and can include such things as direct endothelial
228
https://t.me/medicina_free
A. Kaleem et al.
Fig. 12.4 The skin paddle of the FFF is seen here being used to reconstruct the lower lip soft tissues and the ALT to reconstruct the upper lip and remaining facial soft tissues. Below the cone
beam CT (CBCT) demonstrates excellent positioning of the FFF for mandibular reconstruction
Fig. 12.5 Patient with ORN of the right mandible
damage, decreased endothelial regeneration, increased brin and platelet deposition
with formation of plaques and calcications, increased intramural and subluminal
brosis, and intimal dehiscence and fragility, in both arteries and veins (Fig.12.8)
[15]. Direct damage to vessels renders them friable and thus easily damaged during
12 Microvascular Free Tissue Transfer in Osteoradionecrosis and Medication-Related…
https://t.me/medicina_free
229
Fig. 12.6 VSP provides predictable and accurate postoperative results with custom hardware
dissection and handling, increased deposition of clot-producing elements leading to
increased rates of thrombosis, and damage to the intimal layer leading to increased
risk of dissection and subsequent anastomotic failure. Extreme care must be taken
during both dissection and handling of irradiated vessels in preparation for microvascular anastomosis. Complete vessel preparation should be performed prior to
division of the ap pedicle, in the event that the vessels appear compromised during
preparation and a second set of vessels needs to be sought out, as this minimizes the
230
https://t.me/medicina_free
A. Kaleem et al.
Fig. 12.7 Patient was treated with en bloc segmental resection of the right mandible, and reconstruction with free bula ap (FFF), and rehabilitated with endosseous dental implants in preparation to receive teeth
Fig. 12.8 Radiated vessel
under microscope
demonstrating brotic
walls and damaged
endothelium
12 Microvascular Free Tissue Transfer in Osteoradionecrosis and Medication-Related…
https://t.me/medicina_free
231
ischemia time for the ap. While microvascular anastomosis in these cases can be
challenging, some techniques can be utilized to mitigate some problems that can
arise. Avoiding the use of double microvascular clamps can help minimize vessel
trauma, and avoiding excessive stretching and dilation can help decrease the risk of
damage. In regard to venous anastomosis, most often done using coupler devices,
vessel fragility must be taken into account when placing vessel edges on the stainless steel pins of the coupler. In most cases, it is usually ideal to use the largest
coupler possible for anastomosis to provide the largest lumen possible for blood
ow, and given the relative elasticity of veins, this is often quite easy to do. However,
in irradiated veins, given the friability of the vessel walls, one must be cognizant of
this, and thus a slightly smaller coupler may be preferable to reduce the risk of tearing the vessel walls. In terms of preparation and anastomosis of the arterial system,
several potential issues must be taken into account, with the majority of arterial
anastomoses being performed using suture techniques. The “PCA technique” [16]
combines three different techniques for vessel anastomosis (i.e., “posterior wall
rst,” “continuous interrupted,” and “airborne” [17]) and provides an excellent
method for radiated vessel anastomosis (Fig.12.9). Performing posterior wall anastomosis rst eliminates the need to turn the micro-clamps over at any point during
anastomosis, thus decreasing twisting and risk of vessel trauma. Furthermore, the
combination of the continuous interrupted and airborne suture technique allows for
visibility of the lumen throughout the anastomosis process, decreasing the risk of
“backwalling.” By using this technique, the surgeon avoids tightening and tying
each subsequent suture and leaves that until the end, at which time is done in an
interrupted fashion. In doing so, the surgeon can ensure to maintain complete visualization of the intima with every passing of the suture needle, whereas if knots are
tied along the way, one loses more and more view of the intima as anastomosis
proceeds, increasing the risk of intimal damage. The anastomosis is performed in an
“in” to “out” direction to minimize the risk of intimal separation.
Poor healing at the anastomotic line with potential breakdown at that level can
be a concern, and thus reinforcement at that site can often be performed. When
passing the suture needle, the surgeon can include a small cuff of adventitia on
either side of the anastomosis to provide an additional bolstering effect while taking
care to avoid having the adventitia fold into the site of the anastomosis. During vessel isolation and preparation, surgeons will often use either monopolar or bipolar
electrocautery, not only to clear the vessels from the adjacent tissues but also to
ligate branches from the vessels. With the increased risk of thrombosis in irradiated
vessels, surgeons should minimize the use of monopolar cautery whenever possible
and should resort to gentle blunt dissection. Furthermore, even the use of bipolar
cautery in ligation of branches carries with it the risk of retrograde thrombosis, and
thus ties or clips should be used whenever possible. Surgeons should always maintain a low threshold to refresh vessel margins whenever there is doubt of the quality
at the site of anastomosis while always taking into account residual vessel length
when doing so to ensure good reach and a tension-free anastomosis. Finally, the
option of using vessels outside of the zone of radiation is also possible; however this
is contingent on having an adequate pedicle length and good vessel caliber match.
232
https://t.me/medicina_free
ab c
degf
A. Kaleem et al.
Fig. 12.9 PCA technique begins with suturing of the posterior wall rst (a, b), the sutures are
continuously passed without tying (c, d), and then nally each suture is tied separately with the
airborne technique, tying the tail with the opposing loop, and this is continued until the end (e–g),
such that one ends up with all interrupted tied sutures. (Cigna E, Cirunga C, Bistoni G, Spalvieri
C, Tortorelli G, Scuderi N.Microsurgical anastomosis with the “PCA” technique. J Plastic Recon
& Aesth Surg. 2008; 61:762–766 (with permission))
In unilaterally radiated necks, using vessels in the contralateral non-irradiated neck
is often used by surgeons [18]. One can also use vessels that are outside of the neck
such as the supercial temporal system, or vessels lower in the neck such as ones
from the thyrocervical system, or even the internal mammary system (Fig.12.10)
and employ techniques such as vein grafts whenever needed. In regard to preoperative assessment of vessels, some surgeons will obtain a CT angiogram of the neck
to evaluate vessels ahead of time. However, caution should still be employed even
if vessels of apparent adequate caliber and quality are seen on imaging, as sometimes these vessels may demonstrate poor ow or wall lesions under microscopic
examination intraoperatively. Given all of this, the surgeon should always keep in
mind that the goal is to obtain the best result possible for the patient. In very rare
instances where appropriate vessels cannot be found, the surgeon may have to consider the option of abandoning a free ap procedure in favor of a local or regional
ap reconstruction.
Соседние файлы в папке Библиотека им академика М.И. Перельмана