Keywords spine - pelvis - bone neoplasms - spontaneous fracture
Introduction
Bone metastasis may be related to risks of functional and neurological damage. The
impediments caused by these damages are not essentially treated by surgeries. There
are several forms of cancer treatment, such as chemotherapy, radiotherapy, immunotherapy,
embolization, radiofrequency, and cryoablation, that can be used.
In the axial axis, the dynamics of the spine, upright in the coronal plane, with three
inclinations in the sagittal plane supported in the sacrum that stabilizes in the
pelvis, goes through the mechanical projection to the acetabulum, head, and femoral
neck. Under normal conditions, this balance is complex and unique. Metastatic lesions,
causing mechanical change, will primarily promote pain.[1 ]
[2 ]
In the vertebra, it is sought to indicate the reestablishment of balance, at the best
moment. This means, lower morbidity, lower impact on stability, less impairment of
the neurological condition, and still considering the extent and prognosis of oncologic
disease. Surgery for spinal stabilization and decompression is a formal, but not absolute,
indication in neurological deficit conditions.[1 ]
[2 ]
The mechanical risk factors to the pelvic girdle and the risk of inability to walk
are a formal indication, not an absolute one, for a surgical approach.
Historically, vertebral metastasis has been treated with extensive spinal cord decompression
surgery or block resection, and external radiotherapy alone or together. This treatment
has high morbidity, and radiotherapy alone provides pain control close to 60%, with
an average duration of 4 months.[3 ] However, doubts of a surgical treatment were better established, and there is no
doubt that surgery associated with radiotherapy provides better local control than
radiotherapy alone.[4 ]
The objectives of the treatment of bone metastasis are pain relief, prevention of
pathological fractures, and preservation of function, to allow early weight discharge,
and, if possible, enable the patient to return to activities and provide an intervention
that will last throughout the patient's life.[3 ]
This is a systematic review of the treatment of metastasis that affect the axial axis,
from the most common way to minimally invasive techniques.
Incidence
Cancer is the second leading cause of death per year in the world population, after
cardiovascular diseases. In 2017, 9.7 million people have died from cancer. The highest
cancer mortality rate was registered in patients > 70 years of age.
Previous studies showed an incidence of 5 to 30% of secondary involvement of the spine,
but in a postmortem study, they showed 70 to 90% of involvement. There is a prevalence
in men, and it is most commonly observed in patients between 45 and 65 years old.[5 ]
[6 ]
The prevalence of primary lesions that eventually affect bone are breast, prostate,
lung, kidney, and thyroid,[6 ]
[7 ] and about 10% of cancer patients are diagnosed through examination findings.[8 ]
[9 ]
Metastatic mechanism
The mechanism of evolution to metastasis is complex, and the most common route of
dissemination is hematogenous.[8 ]
[9 ]
Clinical presentation
Four criteria are fundamental in the treatment decision: 1 - neurological condition;
2–biomechanical condition; 3 - cancer extension; and 4 - comorbidities.
Spine
Pain is the main symptom reported, and it precedes all others.[3 ]
[10 ]
[11 ]
In the biological mechanism, there is action of cytokines, which irritate the periosteum
and stimulate the intraosseous nerves, in which there is increased intra-bone pressure
or mass effect caused by the tumor. Improvement can be achieved with steroid use.
At this stage, the treatment is systemic and with radiotherapy.
In the mechanical apparatus, there is structural change of the vertebra. The presence
of the lesion will destabilize the framework, and the axial load will determine the
degree of impairment, which may be mechanical and/or neurological. Symptomatology
may precede radiographic evidence. In this circumstance, steroids do not work, but
improvement can be achieved with narcotics and orthotics, with surgery being the alternative
to be considered before chemo or radiotherapy.[2 ]
[3 ]
[12 ]
Neurological signs
The involvement of the cervical or lumbar region may present with signs of root irritability,
with involvement of the respective dermatomes.[12 ]
[13 ]
[14 ]
[15 ]
Impairments of thoracic levels may generate ipsilateral radiculopathy to the lesion
but are less characteristic.[12 ]
[13 ]
[14 ]
[15 ]
Depending on the area, the spinothalamic tract may present symptoms corresponding
to its compression. There may be root pain due to vertebral instability during mobility,
and relief at rest.[12 ]
[13 ]
[14 ]
[15 ]
Considering that metastasis begins in the body from anterior to posterior, we can
find myelopathy, starting the picture with hyperreflexia, sign of Babinski and Clonus.
With the progression of the lesion, the patient may present weakness, sensory alteration,
pressure, change in temperature and pain, and the proprioceptive process suffers varied
damage, and fine sensitivity will be the last. When this occurs, pressure, pain, and
propriception below the compression level are interpreted as autonomous dysfunction,
and due to spinal cord or cauda equina compression, hyposensitivity and vesicofecal
sphincter alteration may occur. When the lesion affects the medullary cone or sacrum,
it leads to isolated sphincter alterations without sensory and motor signs.[12 ]
[13 ]
[14 ]
[15 ]
In the lesion below the medullary cone, sphincter alteration occurs later with root
changes and prominent mechanical pain.[12 ]
[13 ]
[14 ]
[15 ]
Focal weakness with decreased reflex is seen in cases of isolated root or brachial
plexus, lumbar and/or lumbosacral v. [Fig. 1 ] shows anatomically the neurological evolution of spinal cord metastasis compression,
and the understanding of the transsection of the spinal cord and the function of the
spinal tracts.[12 ]
[13 ]
[14 ]
[15 ]
Fig. 1 (A ) illustrates the cross section of the spinal cord and the possibilities of metastases
in the spinal cord, intraespinal, intradural, extradural intracanal, as well as extraforaminal
intraradicular and bone vertebral metastasis. (B ) scheme of the distribution of sensory spinal tracts and the motor tract, a and b)
gracile and cuneiform fasciculi: sensitivity of fine touch, vibration and position;
c) lateral corticospinal tract (pyramidal), movement ability tract; d) lateral thalamic
thorn tract, pain and temperature tract; e) anterior thalamic thorn tract, pressure
sensitivity tract; f) anterior corticospinal tract (pyramidal), movement ability tract;
g) spinocerebellar tract (Grower spine), proprioception; h) spinocerebellar tract
(Flechsig fascicle), proprioception; m) central motor area, posterior and anterior
horn. Compression usually occurs from anterior to posterior, and progressive sensory
loss will go from pressure area to motor area to fine sensitivity.
Pelvis
In the pelvis, the symptoms will clearly depend on the affected area. Areas in the
iliac wings without involvement of the sacrum will have symptoms during trunk rotation
or on direct palpation; when the sacroiliac joint is affected, there will be pain
when walking, sitting, and even when lying down, in more joint-compromising cases.
In the acetabulum, there are gait-related symptoms the greater the involvement, going
from discomfort, in the case of minor injuries, to full inability to support. In the
regions of the ischium and pubic branches, if metastasis compromises the pubic bone,
near the symphysis, there will be pain during rotations and standing, and if there
is involvement close to the acetabulum, pain in the inguinal region is frequent, but
it does not impede walking; when the lesion is predominantly in the ischium, there
is frequent discomfort to sit and pain in the gluteal region, with or without irradiation
to the thigh, depending on the extent of the disease.[16 ]
Imaging
Imaging study is directed according to the clinical complaint. In vertebral lesions,
it is recommended to perform an imaging study of the entire spine. In 20% of cases,
lesions can be found at other vertebral levels and in the pelvis.[13 ]
[17 ]
Radiography
The presence of symptoms and of the “one-eyed owl” represent bone loss of 30 to 40%,[12 ] and evaluation of the vertebral axes indicates whether the lesion is lytic, blastic,
or mixed.[18 ]
[19 ]
This method is used in the monitoring of mechanical evolution and in the evaluation
of the pharmacological response of bisphosphonates.
Bone Scintigraphy
The most commonly used radioisotope is methylene technetium-99m diphosphonate (Tc99),
which is more sensitive to detecting bone metastasis.[16 ] It presents sensitivity and specificity of 80% and 88%, respectively. Due to the
low cost and good results of analysis, it remains a bone investigation test used for
staging the lesions. Lesions with osteolytic component, such as thyroid and kidney
metastases, may have low or negative uptake.[20 ]
[21 ]
Computed tomography (CT)
Computed tomography has been useful in clinical situations of surgically manipulated
patients with implant material in the vertebra. It can be used with myelography to
determine the level of compression.[19 ]
[22 ]
Magnetic resonance imaging (MRI)
Magnetic resonance imaging became the examination of choice for the analysis of metastatic
lesions of the spine, with high sensitivity and specificity.30 It allows visualization of the extent of bone as well as epidural and radicular injury,
especially in T2-weighted imaging. Magnetic resonance imaging with contrast and diffusion
as well as infusion study should be used.[23 ]
Positron emission tomography/computerized tomography (PET/CT)
The 2-[F-18]- fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) assists
in the diagnosis of metastatic implant with improved specificity. However, the sensitivity
maintains results similar to those of bone scintigraphy. The difficulty is found in
lesions with osteoblastic areas.[19 ]
The difference between bone scintigraphy and PET-CT is the ability to evaluate metastatic
lesions that do not compromise bone alone. The use of other radiopharmaceuticals,
such as fluorine, associated with PET has increased the sensitivity of the results.[21 ]
Staging and Classification
The initial evaluation of the management considers response and sensitivity of the
tumor to radiotherapy. In the radiosensitive tumor, we hope to have greater durability
of the treatment effect, and the radioresponsive tumor is expected to have a faster
response to treatment. With this information we can predict how quickly the tumor
will regress with treatment, which makes it important for the decision of cases with
epidural compression.
Examples of tumors with intermediate response in relation to radiosensitivity are
breast, prostate, and squamous cell carcinomas. Examples of tumors with unfavorable
responses are renal, thyroid, and melanoma carcinomas.
In surgical planning, we must consider tumor vascularization. Classically, kidney
and thyroid metastases are hypervascularized, with risk of excessive intraoperative
bleeding. Preoperative selective embolization is suggested.
There are several classifications available, which help to determine treatment. We
highlight some of the most common use: the Spine Instability Neoplastic Score (SINS)
instability score, specific for patients with vertebral cancer, ranges from 0 to 18.
Based on six radiographic and/or clinical variants. It is considered: stable (0–6);
potentially unstable (7–12), and unstable (13–18). The interobserver reliability was
high (0.846 and 0.886), specificity of 80% and sensitivity of 95%.[24 ] If further judgments are required, the Tomita and Takurashi scores may assist in
the decision.[25 ]
[26 ]
[27 ]
The understanding of the neurological state and the degree of compression and by which
approach are feasible easy to understand by the surgeon. [Figs. 2 ] and [3 ] show examples of these guidelines.[28 ]
[29 ] However, the judgment of how effective and beneficial the surgery will be to the
patient is controversial, and several classifications are being published in order
to avoid poor indication. The same thinking is applied inrelation to the use of new
drugs that have improved the survival of patients with lung, kidney, and melanoma
cancer in order to modify the applicability of these “scores”.[24 ]
[25 ]
[26 ]
[27 ]
[30 ]
[31 ]
[32 ]
[33 ]
[34 ]
[35 ]
[36 ]
[37 ]
[38 ]
[39 ]
[40 ]
[41 ]
Fig. 2 Weinstein, Boriani, Biagini (WBB) classification (1997). The zones begin” from the
spinous to the previous process, clockwise, the prefixes A–E are the radial levels
of vertebral involvement: A: paravertebral soft tissues; B: superficial intraosseous;
C: deep intraosseous; D: extra-dural extra-osseous; E: intradural extra-osseous. Allows
planning of vertebral resection.
Fig. 3 Graduation of 6 medullary compression points (6 points ESCC- epidural spinal cord
compresion)—0 - only bone disease; 1a - contact without deforming the thecal sac;
1b - deformation of the tecal sac without touching the medulla; 1c - deforms the tecal
sac and touches the medulla; 2 - spinal compression but with visible liquor around
the spinal cord; 3 - spinal cord compression without visibility of the liquor around
the medulla—allows neurological understanding with morphological analysis of epidural
compression.
Surgical techniques
We will approach the lesions located in the vertebral bone tissue, in addition to
the intracanal extension, with or without spinal cord compression.
We will address pelvic and acetabula lesions.
We will not address intracanal, intra or extra dural, or root metastases.
Clinical scenarios
1-
Single vertebral metastasis, painless and without neurological impairment
Systemic treatment is the most indicated. Control through imaging.[41 ]
2- Single vertebral metastasis , with pain and without neurological impairment
The risk of pathological fracture and the need to indicate surgical treatment or not
should be evaluated. In the latter case, consider systemic treatment and radiotherapy.[4 ]
[41 ]
3- Single vertebral metastasis, with pain and neurological impairment
This clinical condition is the most complex. Resections of single metastasis are questionable
as to their curative character.
If the metastasis is sarcomas, we can consider chemotherapy and subsequent reassessment.
If there is no progression of the disease, and it is still possible to resect, we
can consider surgical treatment. In the single metastasis of breast, prostate, or
gastrointestinal tract adenocarcinoma, one can only achieve better local control.
Resection of the single vertebral metastasis of renal carcinoma can lead to local
control, with a decrease in local events, without fully ensuring the cure of the disease.
In the single metastasis of variants of papillary thyroid carcinoma, in which radioactive
iodine and radiotherapy may not adequately control the disease, resection may be considered.
However, decompression, radiotherapy and systemic treatment are indicated most often,
and can control the disease.[4 ]
[41 ]
[Fig. 4 ] shows an example of metastasis of osteosarcoma of the sacrum submitted to partial
resection of the sacrum, preserving the roots of S2 and S1, with adequate local control.
3a- Should vertebral metastasis with complete paralysis be addressed?
The need for diagnostic confirmation, or whether there has been a histological change,
should be considered.
There should be patient restaging, and confrontation of the clinical status with the
surgery of wide margins determining local control, if it is single metastasis, which
may result in a better survival. If the disease is advanced, in other organs and bones,
it is considered the best treatment according to the primary tumor/histological type.[41 ]
[42 ]
3b- Is neurological damage recoverable?
It is known that the longer there has been neuronal damage, the lower the chances
of recovery. And as long as there is full decompression, some neurological recovery
is possible. Long-standing compressions can benefit from fixation and stabilization
surgery, if it allows the patient to be seated and mobilized, to prevent sours and
other complications, in addition to improving pain and sensation, but sphincters are
more unlikely to recover.[4 ]
[41 ]
[42 ]
Total spondylectomy of vertebra with metastasis causes a shortening of up to 1.0 cm,
generating greater blood supply, and due to this increase in spinal cord blood flow,
neurological recovery is more likely.[43 ]
4- Multiple vertebral metastases, pain-free and without neurological symptoms
In this clinical situation, it is possible to keep the patient under observation while
waiting for oncological responses to systemic treatment. Protection with vest and
periodic evaluations becomes an adequate conduct. The use of a vest is indicated because
it provides safety, serves as a warning for care and risk of falls, but there are
no clinical studies showing its efficacy.[4 ]
[41 ]
[42 ]
[43 ]
5- Multiple vertebral metastases, with pain and without neurological symptoms
Treatment should be discussed in a multidisciplinary manner, with confirmation of
the painful vertebra and analysis of fracture risk.
Percutaneous techniques can be considered. Vertebroplasties with or without the balloon
are possible, since the thermal and mechanical effect of bone cement is immediate.
Radiotherapy should be considered at this stage of the disease.[4 ]
[41 ]
[42 ]
[43 ]
6- Sacral metastasis and lumbosacral transition
This region undergoes a great mechanical force of traction and rotation.
The presence of pain should show the need for intervention. Complete resections require
double route, and fixation of the lumbar spine with the iliac wings is a fairly valid
tactic that diverts mechanical forces without compromising function, and it is better
when the hip joint is intact.[44 ]
7- Pelvic metastasis - iliac wing and pubic region
These two regions are outside the axial and sagittal mechanical axes, but not of the
rotational axes. Resection of these areas will not have major impacts on the possibility
to stand and walk but can cause pain and disability in the rotational process.
Metastasis in the pubic region, especially in males, where incisional hernia may form
associated with involvement of the scrotal stalk, with the presence of pain during
sexual activity. These complications can be mitigated with the use of muscle screens
and rotations.
The association of percutaneous techniques with the introduction of bone cement, or
another method such as radiofrequency, can prevent resections.[45 ]
8- Metastasis in the acetabular region
In the acetabular region, the torque area is larger in the central area, and lesions
with posterior predominance will present more marked pain when lifting and sitting,
while in the anterior region, the pain will be in the trunk extensions.
Percutaneous techniques with the introduction of bone cement applying the same technique
used in vertebroplasty have been favorable.
When there is a fracture with joint involvement, resection and reconstruction with
arthroplasty and acetabular reinforcement may be necessary. Risk and benefit assessment
are necessary and should be discussed by a multidisciplinary team.[45 ]
Fig. 4 Female patient, 47a chondroblastic osteosarcoma, 2008, presented with pathological
fracture of the right distal femur and underwent neoadjuvant treatment with right
knee stent. In 2017, she developed disseminated bone metastases and recurrence in
the right popliteal fossa. She presented sacral lesion with severe pain when walking,
and she was able to ambulate again after spinopelvic fixation. The patient died in
2020 from sepsis of the urinary tract.
Preoperative procedures
Arterial sacrifice
This technique is most often performed in cervical surgeries in which the involvement
of the vertebra is associated with the vertebral artery. It may occur inadvertently
or be performed in a planned manner. Occlusion of the vertebral artery is more related
to cerebellar damage than to brain damage. Another way is super selective embolization
to contain intraoperative bleeding, being an appropriate tactic to reduce complications.[25 ]
[46 ]
Surgical Procedures
Systematizing by Location
Technically, surgery of the vertebral half is the removal or curettage of multiple
fragments, few services use the radical technique with a block removal of metastasis.
Craniocervical junction
Painful metastatic lesions and/or compressions are very critical, as they compromise
the beginning of the medulla as well as the bulb area, and the olives are a risk site
that can lead to death.
Two approaches to decompression are used, longitudinal and/or oblique paravertebral
incision. In cases in which occipto-cervical fixation is required, the midline approach
will be sufficient for this procedure. The fixation methods with pedicular or facet
plates or screws are adequate, in addition to the decompression of the necessary segments
that include part of the occipto-C1-C2.
Stabilization of the vertebrae below the decompressed segment is required, with a
minimum of two vertebral bodies below the decompressed one.[46 ]
[47 ]
[48 ]
Transoral, translingual, and transmandibular
This approach is complex. It is recommended that a head and neck surgeon and/or otorhinolaryngologist
are present during the surgery. The lesions in the anterior region of C1 and C2 are
the most appropriate for this procedure. The type of access depends on the experience
of the surgeon. Reconstructions after decompression are difficult to fix, and there
are important risks of complications, including speech, swallowing, and respiratory
risks. A multidisciplinary team should evaluate the risks and benefits of the procedure.[46 ]
[47 ]
[48 ]
Lateral approach to the vertebral and cervicothoracic skull junction
The approach is related to the decompression of high radiculopathies (C1 to C2).
A multidisciplinary team should evaluate the risks and benefits of the procedure,
especially risks of the cranial pairs and jugular artery and vein, and the carotid
artery.[46 ]
[47 ]
[48 ]
Pancoast Tumor
Neoplasia involving the pulmonary apex, with invasion of the T2/T3 vertebrae, and
proximity to the brachial plexus and the subclavius vessels. Despite the starganglion,
they produce symptoms according to the degree of impairment of the anatomical structures,
going from symptoms of high back and scapular waist pain progressing to neurological
symptoms related to the compromised roots, especially T1 and T2, as well as eyelid
ptosis, with exophthalmia (Horner syndrome).
Vertebral resections are associated with lesion resectability, and are divided into
three types:
Type A: when it invades the transverse region and part of the intervertebral system.
Type B: when its extension corresponds to less than 1/3 of the vertebral body.
Type C: when it involves 2/3 of the vertebral body.
Thus, the magnitude of the surgery increases according to this impairment.
It is notorious that complications come from this surgery, going from respiratory
problems to neurological damage, especially to the root of T1.[49 ]
Transthoracic surgical access
Open surgical access allows ample exposure, but with risks associated with bleeding
and atelectasis. In this technique, there is the possibility of resecting close to
75% of the vertebral body; however, the pedicle area and the wall contralateral to
the surgical access cannot be adequately reached.
Surgical access in lateral decubitus allows access to the region of the scapular angle.
For higher access, the medial lip is used, and the 4th rib is resected. For the T5
to T12 vertebrae, the resection takes place between the 7th and 8th ribs.
Usually, the patient is positioned in right lateral decubitus, but in oncology it
depends on where the largest tumor is. The venous structures and the thoracic sympathetic
plexus are definitely connected to perform the procedure.[50 ]
Thoracoscopy resection and reconstruction
Thoracoscopy is a technique indicated for resecting the vertebral body of the anterior
region in fragments, working very well for single lesions, and it should be associated
with the titanic cage and anterior plate. It has the limitation of making it impossible
to resect the wall and the contralateral pedicle.
Vertebral sagittal osteotomy, longitudinal hemi-vertebrectomy - thoracic and lumbar
region
The posterior approach through the midline, with the resection of the posterior elements
(uni or bilateral). Resection of the right half of the vertebra has increased security.
The left half has a risk of aortic injury.
This technique may not offer adequate oncological margin.
Combined lateral and posterior approach
This is a technique employed for large extravertebral masses that partially involve
the vertebral body. Osteotomy is performed from posterior to anterior, and it can
only be from the posterior arch or the vertebral body.
This is a more difficult technique due to the need to sacrifice vessels and nerve
roots that cross the lesion.[5 ]
Total vertebrectomy of cervical vertebrae
This is a complex approach, and one that may involve the sacrifice of the vertebral
artery or dissection and isolation thereof. The approach is by double track, and the
indication is reserved for selected cases. The procedure is always started posteriorly
and followed by the anterior route.
Arterial ligation may be endovascular or intraoperative.[46 ]
[47 ]
[48 ]
Total vertebrectomy of the thoracic and lumbar spine
This procedure is less complex than in the cervical region.
Doable in single metastasis. No indication in disseminated metastasis.[25 ]
[50 ]
Hemicorporectomy and inter-ilium-abdominal disarticulation for vertebro-sacrum-pelvic
junction lesions
These extreme resections are little used in metastases. They are more frequent in
primary neoplasms with low potential for metastases, with curative objective.[51 ]
Reconstruction of the sacrum-iliac joint
This procedure is reserved for cases of metastases in the sacrum, especially those
involving sacroiliac joint, without the indication of resecting the sacrum, in which
there is compression or fracture component. Thus, fixation of the spine, usually L4
to L5, and iliac promotes comfort, and reduces pain, and decompression determines
improvement, especially of cauda equina syndrome.[45 ]
[53 ]
[54 ]
[55 ]
Sacral resection
Reserved mainly for lesions below the third sacral vertebra that generate little functional
impairment in the sphincters. In some cases, total resection may be considered, but
with sphincter sequelae. In this technique, advances of the maximum gluteus muscles
should be made to avoid incisional hernia of the sigmoid neck and anal canal, which
can be painful, especially in the act of evacuating and sitting.[53 ]
[54 ]
[55 ]
[56 ]
Pelvic injury
It is quite difficult to understand that there is no fracture risk rating for these
metastatic injuries. In addition, the mechanical situations in the three regions are
different. Thus, the location of metastasis determines the forms of treatment.[45 ]
[57 ]
[58 ]
[59 ]
Iliac wing
The metastatic lesion on the iliac wings does not compromise the ability to walk or
biped-station. However, it compromises rotational movements with flank pain, and irradiation
to the gluteus and pelvic region. Simple resection without reconstruction may be indicated.
The non-placement of screens or reinsertion of the musculature can determine the appearance
of incisional hernias. External radiotherapy is favorable but has a delay in ossifying
the lesion.[16 ]
[45 ]
[57 ]
[60 ]
Ischiopubic Branch
This region is more symptomatic than the iliac wings due to the support area, and
because it has the center of rotation next to the pubic synphysis, associated with
the impact of gait on the acetabulum. Surgery in this region differs according to
the symptoms and sex of the patient.
Bladder hernia is frequent and can be painful in both.
In women, there may be a greater number of urinary infections, and even herniations
of the intestinal loop.
In males' scrotal hernia, hydrocele can occur and, according to resection, there may
be impairment of penile insertion, resulting in physiological changes.
Painful coitus is also reported after this procedure.
Radiotherapy in this region has more complications according to the technique and
the symptoms, due to the affected organs, going from voiding urgency to urethral stenosis,
among others.[16 ]
[45 ]
[57 ]
[60 ]
Acetabulum
The region is more complex due to circumferential involvement.
We divide the involvement into anterior, medium, and posterior.
There may be involvement of one or more areas, with or without fracture of the joint.[45 ]
[57 ]
[58 ]
[59 ]
Complications
Among the most frequent clinical and surgical complications are deep vein thrombosis
and surgical infections.
MINIMALLY INVASIVE SURGICAL TREATMENTS
Injection of percutaneous bone cement (vertebronplasty, chiphonoplasty)
Indicated for painful vertebral lesions, without full instability, or that do not
have spinal cord compression, provided that the posterior wall of the vertebra is
intact. This is the necessary condition for cement not to leak into the medullary
canal and cause neurological damage.
The pathway may be transpedicular and/or paravertebral, guided by radioscopy or CT.
Painful single lesion with diagnosis, and without neurological, is a great indication.
The problem lies when there are multiple painful lesions to properly assess which
lesions are symptomatic, and whether there is cortical rupture or fractures.
The lesions produce destruction, and the cement penetrates effortlessly in the vast
majority of cases. The penetration of cement at increased speed and pressure provides
risks, including venous embolism that spreads through the azygos system can compromise
lung tissue, with varied consequences until death.
The reaction to the quantity is not very basic, and it is difficult to establish how
many vertebrae can be addressed in the same procedure. Complications with embolism
and cardiac arrest can occur, and it is important not to exceed more than three bodies
per procedure.[58 ]
[59 ]
Radio frequency
This palliative treatment is recommended for painful vertebrae, mixed, and blastic
lesions, in which no mechanical reinforcement is required. The technique introduces
the needle after a path has been created with a drill or trephine, so it is understood
that penetration into dense tissue is limited. It follows the same indications for
vertebroplasty, but the time and temperature must respect the proximity to neural
structures. If properly positioned up to 100° C for 6 minutes, it may provide relief of painful symptoms for up to 3 months.[58 ]
[59 ]
[Fig. 5 ] shows a case of multiple metastases of thyroid papillary cancer submitted to various
percutaneous procedures with adequate pain and functional control.
Fig. 5 Patient, 67a Yellow F. History of Papillary Thyroid Carcinoma, submitted to several
percutaneous procedures, radiofrequency associated with “vertebroplasty”, and cementation
of lesions around the sacroiliac joint of the acetabulum (acetabuloplasty) and percutaneous
fixation of the proximal femur, keeping it in functional stability without interrupting
systemic treatment.
Combination of percutaneous techniques
It is possible to combine techniques such as radiofrequency with vertebroplasty or
other techniques to avoid failure of a single method.[58 ]
[59 ]
Final Considerations
Extensive knowledge of metastatic disease and of the advancement of various forms
of treatment and improvements in surgical techniques are necessary to support patients
in this more aggressive phase of the disease. However, the best management strategy
is frequent oncological evaluation to prevent adverse advents.
