1.1 General information
A total of 120 patients with spinal and pelvic tumors undergoing puncture biopsy in our department were recruited and assigned to the new biopsy device group (group A, n=60) and the conventional biopsy device (group B, n=60). Among 40 patients with spinal tumors and 20 with pelvic tumors in group A, 43 presented with osteogenic bone destruction, and 17 with osteolytic bone destruction. Among 40 patients with spinal tumors and 20 with pelvic tumors in group B, 30 presented with osteogenic bone destruction and 30 with osteolytic bone destruction.
1.2 Biopsy devices
A 64-slice spiral CT machine, disposable thoracentesis package, 100 ml of normal saline, 10 ml of 2% lidocaine hydrochloride injection, heparin sodium injection, a novel puncture biopsy device (Figure 1，We have applied for a patent，the patent number was ZL 2019 2 2137859.8) and a conventional puncture biopsy device (Figure 2) were used in this study. We modified the injection cannula of the bone cement pusher used in PVP. Its smooth edge was serrated with proper size, thickness, rigidity and strength.
1.3 Preparation for puncture biopsy
Routine blood test, coagulation factor test and imaging examinations were performed. Informed consent was obtained prior to puncture biopsy. Eligible were patients who were in good general conditions, could maintain a supine or prone position for a minimum of 30 min, presented normal routine blood and coagulation indexes, and had intact skin at the site of puncture.
1.4 Biopsy groups and Methods
1.4.1 New puncture biopsy device group (group A)
(1) Spinal tumors
Approaches through the pedicle, costovertebral joint or lateral vertebra were set in the biopsy for the spinal tumor. Puncture targets, entry points and angles were marked with preoperative CT. After routine sterilization and draping, local anesthesia was performed by injecting 2% lidocaine hydrochloride into the periosteum of pedicles with a long, thin needle. Through a 1-cm longitude incision, the modified needle was inserted through the pre-determined entry point and angle. The guide wire was withdrawn once having approached the pedicle of vertebral arch. Subsequently, the injection cannula of the bone cement pusher was inserted into the vertebral needle trajectory created according to PVP procedures, and fixed. A 60 ml syringe connected to the end of the injection cannula of the bone cement pusher, in which a negative pressure spring was placed, was slowly inserted into the tumor lesion for aspiration. During the rotary cutting by the serrated edge, columnar tissues with a diameter of the inner injection cannula were collected, placed in normal saline containing heparin, and filtered using sterilized gauze. The injection cannula of bone cement pusher was extubated, while the vertebral needle trajectory was retained for repeated biopsies using the rotary-cutting technique at different angles and depths, until satisfactory samples were obtained. Biopsy samples were finally fixed in 4% formalin and sent for pathological examinations.
(2) Pelvic tumors
The entry point was set within the scope of skin incision. Puncture targets, entry points and angles were determined by preoperative CT. The biopsy procedures for pelvic tumors were similar to those for spinal tumors.
1.4.2 Conventional puncture biopsy device group (group B)
(1) Spinal tumors
Approaches through the pedicle, costovertebral joint or lateral vertebra were selected in the puncture biopsy for spinal tumors. Puncture targets, entry points and angles were determined by preoperative CT. After routine sterilization and draping, local anesthesia was performed by injecting 2% lidocaine hydrochloride into the periosteum of pedicles using a long, thin needle. Through a 1-cm longitudinal incision, the conventional needle was inserted through the pre-determined entry point and angle, and advanced to the pedicle of the vertebral arch. Biopsy samples were collected by the rotary-cutting technique , placed in normal saline containing heparin, filtered using sterilized gauze and fixed in 4% formalin for pathological examinations.
If the tissue without lesion was punctured, the above steps were repeated again to obtain the pathological tissue by repeated puncture.
(2) Pelvic tumors
The entry point was set within the scope of skin incision. Puncture sites, entry points and angles were determined by preoperative CT. The procedures of puncture biopsy for pelvic tumors were similar to those for spinal tumors.
1.5 Evaluation index
The puncture time, positive rate, consistency rate, and dependence rate between group A and B were compared to assess the efficacy and safety of the new device. In detail, positive biopsy was defined as the definite diagnosis or qualitative diagnosis of samples; and negative biopsy as failure to obtain samples, or samples having no pathological diagnostic values and leading to inaccurate qualitative diagnosis. The consistency was defined as agreement between diagnoses based on biopsy samples and postoperative results. The dependence was defined as patients’ cooperation and satisfaction during the puncture biopsy.
1.6 Statistical Processing
SPSS 21.0 statistical software was used for analysis. The measurement data were expressed as mean ± standard deviation (X¯±S )and the counting data as a percentage (%). T-test was used for measurement data, the chi-square (χ2) test or non-parametric test was used for counting data, and P<0.05 was considered statistically significant.