Resultado da cifoplastia no tratamento minimamente invasivo das metástases vertebrais

Objetivo: Avaliar o resultado clinico e radiologico do tratamento cirurgico minimamente invasivo das metastases vertebrais por meio da tecnica de cifoplastia. Material e Metodos: Este e um estudo observacional prospectivo de pacientes com o diagnostico de metastase vertebral e que foram submetidos ao tratamento cirurgico minimamente invasivo por meio de preenchimento do corpo vertebral com a tecnica de cifoplastia com balao. A avaliacao clinica incluiu a idade do paciente no momento da cirurgia, o diagnostico do tumor, os resultados das biopsias,  os dados do procedimento cirurgico realizado, a escala visual de dor (EVA) e as complicacoes relacionadas a cirurgia. A avaliacao radiologica envolveu o estudos dos exames radiograficos nas incidencias anteroposterior e lateral, com a analise da cifose do corpo vertebral e a ocorrencia de extravasamento do cimento. Resultados: Foram estudados 22 pacientes portadores de metastase vertebral que foram tratados por meio de cifoplastia com balao, sendo 8 (36%) do sexo masculino e 14 (64%) do sexo feminino. A idade media foi de 56,05 anos e o tempo medio de seguimento 8,5 meses. A media da EVA pre-operatorio foi de 8,73, no pos-operatorio inicial de 1,73 e no pos-operatorio tardio de 1,92. Conclusao: a cifoplastia mostrou-se uma tecnica segura e efetiva para o tratamento sintomatico das metastases vertebrais.


INTRoDuCTIoN
One characteristic of metastatic disease involving the spine is the presence of fractures of the vertebral bodies affected by the tumor. 1,2][5][6][7] Balloon kyphoplasty is a minimally invasive procedure that pro-motes stabilization of spinal fractures and correction of the kyphotic segmental deformity resulting from the fracture. 8,95][16][17][18][19][20] Moreover, these studies were usually conducted with heterogeneous groups, including osteoporotic fractures. 15,18The objective of this study was to evaluate the results of the treatment of spinal tumor lesions using the balloon kyphoplasty technique.

mATeRIAL AND meTHoDS
This is an observational study of a prospective database of patients diagnosed with spinal tumor lesions and treated using the balloon kyphoplasty technique.Following approval by the local Research Ethics Committee, the study was conducted via clinical evaluation, radiological evaluation, and review of medical records and radiological archives.All patients with spinal tumor lesions treated with the balloon kyphoplasty technique during the period from August 2010 to January 2014 were included.Patients who underwent kyphoplasty for other diagnoses and patients with spinal tumor lesions who underwent other types of treatment were excluded.All surgical procedures were indicated by the same surgeon, and the criteria adopted were the existence of a spinal tumor lesion and local pain in the topography of the affected vertebra.The clinical history and radiological evaluation were used to establish a diagnosis of fractures secondary to the tumor.The procedure was contraindicated in the presence of neurological deficit or compression of the spinal canal by the tumor lesion.Twenty-two patients aged between 16 and 85 years of age participated in the study: 14 females and 8 males.
The patients were evaluated preoperatively by applying the visual analog pain scale (VAS) to determine pain intensity, where zero indicates "without pain" and 10 indicates "very strong pain". 21The type and location of the tumor and duration of symptoms were also evaluated.A radiographic assessment was performed using anteroposterior and lateral x-rays, measurement of the angle of vertebral kyphosis (wedging) of the affected vertebrae, 22 nuclear magnetic resonance of the whole spine to identify other lesions, and computed tomography of the affected region to evaluate the integrity of the posterior cortex.(Figure 1) The surgical procedure of balloon kyphoplasty was performed under general anesthesia with the aid of a fluoroscope, and the technique used was the same as that described by other authors. 8,23,24uring the surgical procedure, a biopsy was performed and the material was sent for anatomopathological analysis for a definitive diagnosis of the lesion.During the postoperative period, rigid orthosis was not used and movement and walking were permitted, as far as the pain allowed.
A clinical evaluation and radiographic exams were repeated on the first day after the operation, and subsequent evaluations were conducted at 1 month, 3 months, 6 months, and 1 year following surgery and then annually.During follow-up, pain intensity using the VAS, 21 clinical complications, radiographic complications, and wedging levels of the affected vertebrae were evaluated. 22ontinuation of oncological treatment followed the customary protocol recommended by the oncology team in response to the anatomopathological results of the biopsy performed.
The data was evaluated for consistency, codified, and transcribed into a database.A descriptive data analysis was performed using Microsoft Excel 2011 ® and SAS JMP ® 11.0 software.

ReSuLTS
We studied 22 patients with metastases affecting at least one vertebral body who underwent the balloon kyphoplasty surgical procedure.Eight were male (36%) and 14 were female (64%), with ages ranging from 16 to 85 years (56.05 ± 16.06).A total of 35 kyphoplasties were performed, 24 lumbar (67%), 10 thoracic (29%), and 1 sacral (3%).(Figure 2) The tumor types are shown in Figure 3. Patient follow-up ranged from zero to 26 months, with an average of 8.5 ± 8.46 months.Of the total number of patients accompanied by the study (n=22), 4 (18%) died during follow-up from complications of the underlying disease and 2 (9%) were lost to follow-up.(Table 1) The VAS ranged from 6 to 10 (average of 8.73 ± 1.12) in the preoperative period, from zero to 5 (average of 1.73 ± 1.39) in the immediate postoperative period, and from zero to 8 (average of 1.92 ± 2.90) in the late postoperative period.There was an average     improvement of 7 ± 1.95 points in the VAS between the preoperative and immediate postoperative periods.There was no statistical difference in the VAS between the immediate and late postoperative periods.(Figure 4) The measurements of the wedging of the fractured vertebrae are displayed in Table 2.There was no difference between the pre-and postoperative measurements.(Figure 5) No neurological or cardiac complications were observed.One case of deep vein thrombosis with pulmonary thromboembolism was observed during hospitalization and was successfully treated with anticoagulants.Leakage of cement in 5 vertebrae (14.29%) was observed during the procedure via fluoroscopic images or postoperatively via radiographs: in 3 cases (8.6%) through the anterior cortex of the vertebral body, in one case (2.9%) to the disc below, and in one case (2.9%) into the spinal canal.The leakage did not cause symptoms in any of the cases.Two patients suffered new fractures during follow-up (9.10%): one in an adjacent vertebra and the other in a distant vertebra.Both were treated conservatively, by observation only, with resolution of symptoms.During follow-up, one

DISCuSSIoN
Morbidity and mortality rates are high in patients with spinal involvement from metastatic disease, and because of improvements in oncological treatment, quality of life has become an extremely important and much studied issue. 1,2,24Balloon kyphoplasty is a minimally invasive procedure capable of stabilizing spinal fractures and reducing pain intensity while improving function and consequently, the quality of life. 10,12,13,23,24However, the mechanism responsible for alleviating the pain is controversial, as it can be attributed either to stabilization or to thermal injury of the nerve endings. 23,25,2623,28 It was shown that despite not having achieved correction during the procedure, short-and long--term improvement of pain was observed without any correlation with the radiographic image.
Additionally, kyphoplasty was shown to be effective and safe, with few complications in the group of patients studied.Among the complications observed, several are related to the procedure (leakage of cement and fracture of the adjacent vertebra), others to the underlying disease (stenosis of the spinal canal secondary to tumor growth, pathological fracture of the vertebra distant from the initial lesion, and the cases of death observed) and others to a combination of factors (pulmonary thromboembolism). 29Among the causes related to the procedure, we observed leakage of cement in 14.29% of the vertebrae and fracture of the adjacent vertebra in one case (2.86%), comparable to those in the literature. 131][12][13] Reviews of studies on vertebroplasty reported rates of cement leakage ranging from 2 to 67% and, when compared, the authors documented leakage rates of 9% for vertebroplasty versus 0% for kyphoplasty. 12,13,28NCLuSIoN Balloon kyphoplasty is a safe, effective, and minimally invasive procedure that offers immediate and long-term pain relief in patients diagnosed with metastasis affecting the vertebral body.
All authors declare no potential conflict of interest concerning this article.literature.Dudeney et al 14 reported pain improvement in patients with a diagnosis of vertebral fractures secondary to multiple myeloma.Another study reported the treatment of a group of 792 patients with varying diagnoses of secondary fractures and tumor lesions with good outcomes in the treatment of pain. 14,27nlike treatment of osteoporotic fractures, restoring the height of the vertebral body is not a priority in the treatment of spinal metastases.Furthermore, it is not clear whether this characteristic is related

Figure 1 .
Figure 1.Example of a patient treated using balloon kyphoplasty.

Figure 2 .
Figure 2. Location of the affected vertebrae.

Table 2 .
Measurement of the angle of vertebral kyphosis.NA=not applicable.patient (4.55%) experienced medullar compression at the level of the pathological fracture caused by tumor growth and underwent radiotherapy, with favorable evolution.(