Cement pulmonary embolism (CPE) is found in 10/68 patients (14.7%).
Mean age,
73.2 years; (range,
33–89 years) and male/female ratio,
1:1.
CPE is observed in 8/39 (20.5%) in the group with thoracic CT versus 2/29 (6.8%) with plain radiographs (Fig.
4).
The following tables summarize the statistical analysis of relationships between different risk factors and cement pulmonary embolism (table 1-5).
Table:1
Relationship between cement pulmonary embolism and presence of cement in the azygos vein.
Azygos cement
|
Cement pulmonary embolism
|
TOTAL
|
Positive
|
Negative
|
Present
|
3 (60%)
|
2 (40%)
|
5
|
Absent
|
7 (11%)
|
56 (89%)
|
63
|
TOTAL
|
10
|
58
|
68
|
Chi-squared = 8.827
The P-value = 0.001 (the association between cement pulmonary embolism and presence of cement in the azygos vein is considered to be a statistically significant).
Odds Ratio =12
Risk Ratio = 5.4
|
Table:2
Relationship between cement pulmonary embolism and presence of cement in the paravertebral veins.
Paravertebral cement
|
Cement pulmonary embolism
|
TOTAL
|
Positive
|
Negative
|
Present
|
10 (24%)
|
32 (76%)
|
42
|
Absent
|
0 (0%)
|
26 (100 %)
|
26
|
TOTAL
|
10
|
58
|
68
|
Chi-squared = 7.258
The P-value = 0.002 (the association between cement pulmonary embolism and presence of cement in the paravertebral veins is considered to be a statistically significant).
Odds Ratio = statistically undefined.
Risk Ratio = statistically undefined.
|
Table:3
Relationship between presence of cement pulmonary embolism and osteoporosis.
Osteoporosis
|
Cement pulmonary embolism
|
TOTAL
|
Positive
|
Negative
|
Present
|
8 (13%)
|
53 (87%)
|
61
|
Absent
|
2 (28%)
|
5 (72%)
|
7
|
TOTAL
|
10
|
58
|
68
|
Chi-squared = 1.196
The P-value = 0.16 (the association between cement pulmonary embolism and osteoporosis is considered to be not a statistically significant).
Odds Ratio = 0.37
Risk Ratio = 0.46
|
Table:4
Relationship between presence of cement pulmonary embolism and bipedicular approach.
Bipedicular approach
|
Cement pulmonary embolism
|
TOTAL
|
Positive
|
Negative
|
Positive
|
9 (15%)
|
51 (85%)
|
60
|
Negative
|
1 (13%)
|
7 (87%)
|
8
|
TOTAL
|
10
|
58
|
68
|
Chi-squared = 0.035
The P-value = 0.46 (the association between cement pulmonary embolism and the bipedicular approach is considered to be not a statistically significant).
Odds Ratio = 1.2
Risk Ratio = 1.2
|
Table:5
Relationship between cement pulmonary embolism and absence of intravertebral vacuum cleft.
Intravertebral vacuum cleft
|
Cement pulmonary embolism
|
TOTAL
|
Positive
|
Negative
|
Absent
|
4 (15%)
|
15 (85%)
|
60
|
Present
|
6 (13%)
|
43 (87%)
|
8
|
TOTAL
|
10
|
58
|
68
|
Chi-squared = 0.846
The P-value = 0.19 (the association between cement pulmonary embolism and absence of intravertebral vacuum cleft is considered to be not a statistically significant).
Odds Ratio = 1.9
Risk Ratio = 1.7
|
In patients with CPE (n= 10),
there were 22 vertebroplasties (at different levels between Th5 and L5),
levels Th11,
L1 and Th12 vertebrae were the most frequent operated sites (18.2%,
18.2 % and 13.6% respectively) (Fig. 6).
All the previous reports described the emboli as sparsely distributed in the peripheral zones of both lungs without a specific lobar localization.
In our study,
distribution of the cement emboli in different lobes of both lung is located.
For unknow reason there are more cement emboli in the left lower lobe (29.6% of cases) compared with the right lower lobe (11.7%) (Fig.7).
To the authors’ knowledge this is the second published study about the incidence of pulmonary cement embolism in a 100% kyphoplasty series after Bliemel et.
al.
Probably we found a higher incidence of CPE (14.7%) in comparison with the former study (1%) because computed tomography of the chest has been used in about 57% of our series in comparison with only 1% of the patients in the study of Bliemel et.
al 11.
A weakness of the current study that 29 patients (42,6%) had only postoperative chest radiographs and no CT scans,
which means that CPE may have been underestimated in this group of patients.
And the time interval between vertebroplasty and chest CTs or radiographs is highly variable in most of patients.