Stability changes after cryosurgery in long tubular bones in correlation to histological results: an animal trial

Fracture risk of vertebral bodies after cryosurgery using a miniature cryoprobe: A biomechanical in-vitro analysis on human bones

INTRODUCTION

Due to spinal instability and compressive neurologic deficits surgical management is sometimes necessary in patients with metastatic spinal lesions. However, in some cases open surgery is not possible and minimally invasive procedures, like cryoablation, are needed. The aim of the current study was to investigate whether a miniature cryoprobe provides adequate tissue cooling in vertebrae and to evaluate the direct impact of cryosurgery on vertebral body stability.

MATERIALS AND METHODS

Twelve thoracic vertebral bodies were harvested from fresh cadavers. After documenting bone density cryoablation was performed in six vertebral bodies according to a standardized procedure. Afterwards temperature inside the vertebral body and maximum breaking force were measured in the control and experimental groups.

RESULTS

Required temperature of -50° was reached in all areas. There was a significant correlation between maximum breaking force and measured bone density (p= 0.001). Mean breaking force within the experimental group was 5047 N (SD = 2955 N) compared to 4458 N (SD = 2554 N) in the control group. There were no observable differences in maximum breaking force between both groups.

CONCLUSION

Miniature cryoprobe can deliver adequate tissue cooling to -50°C in vertebral bodies. The procedure does not seem to influence breaking force of the treated bones in-vitro. Therefore, using miniature probes cryosurgery may provide a valuable alternative to conventional surgical resection of neoplastic diseases as well as of benign locally aggressive bone tumors.

Image-guided cryoablation for the treatment of painful musculoskeletal metastatic disease: a single-center experience

PURPOSE

The role of image-guided thermal ablation techniques for the nonoperative local management of painful osseous metastatic disease has expanded during recent years, and several advantages of cryoablation in this setting have emerged. The purpose of this study is to retrospectively evaluate and report a single-center experience of CT-guided percutaneous cryoablation in the setting of painful musculoskeletal metastatic disease.

METHODS

This study was approved by the institutional review board and is compliant with the Health Insurance Portability and Accountability Act. Electronic medical records of all patients who underwent percutaneous image-guided palliative cryoablation at our institution were reviewed (n = 61). An intent-to-treat analysis was performed. Records were reviewed for demographic data and anatomical data, primary tumor type, procedure details, and outcome-including change in analgesic requirements (expressed as morphine equivalent dosages), pain scores (utilizing the clinically implemented visual analog scale), subsequent therapies (including radiation and/or surgery), and complications during the 24 h following the procedure and at 3 months. Patients were excluded (n = 7) if data were not retrospectively identifiable at the defined time points.

RESULTS

Fifty-four tumors were ablated in 50 patients. There were statistically significant decreases in the median VAS score and narcotic usage at both 24 h and 3 months (p < 0.000). Six patients (11%) incurred complications related to their therapy. Two patients had no relief at 24 h, of which both reported worsened pain at 3 months. One patient had initial relief but symptom recurrence at 3 months. Four patients went on to have radiation therapy of the ablation site at some point following the procedure.

CONCLUSIONS

CT-guided cryoablation is a safe, effective, reproducible procedural option for the nonoperative local treatment of painful musculoskeletal metastatic disease.

Pedicle versus free frozen autograft for reconstruction in malignant bone and soft tissue tumors of the lower extremities

BACKGROUND

Of the biological reconstruction methods for malignant bone and soft tissue tumors, reconstruction with liquid nitrogen has the advantage of maintaining continuity on the distal side of the tumor bone site (pedicle freezing procedure; PFP). This method is expected to result in early blood flow recovery, with early union and low complication rate. The purpose of this study was to compare the outcomes of the PFP and free freezing procedure (FFP) in the lower extremities.

METHODS

The study included 20 patients (12 men and 8 women) with frozen autografts (FFP, 13 cases; PFP, 7 cases). The mean age of the subjects was 36.3 years (range 11-79 years), and the mean follow-up period was 56.4 months (range 12-142 months).

RESULTS

Final bone union occurred in 11 patients in the FFP group (84.6%) and in 7 patients in the PFP group (100%). The mean union period in patients who did not need additional surgery was 9.8 months (range 4-21 months) in the FFP group and 4.8 months (range 2-7 months) in the PFP group. Postoperative complications occurred in 8 cases: infection in 3 cases, fracture in 3 cases, and joint destruction in 2 cases. Six FFP patients, and 2 PFP patients (two cases of fracture), developed postoperative complications.

CONCLUSIONS

The union period was shorter and the rate of postoperative complications was lower with the PFP than with the FFP. We considered that early blood flow recovery might have led to the above results in the PFP.