CT-guided bone biopsy: Initial experience with a commercially available hand held Black and Decker drill

Comparison of powered drill & manual bone biopsy systems: Does the diagnostic yield justify the cost?

Bone biopsies are traditionally performed using manual drill devices. More recently, powered drill biopsy systems have been developed, ostensibly to improve diagnostic yield. We compare the powered drill biopsy system to traditional manual needle devices on the basis of diagnostic yield, specimen size and material costs. 309 consecutive bone biopsy procedures performed with imaging guidance from a single academic institution were retrospectively reviewed. Specimen diagnostic adequacy, qualitative interpretation of diagnostically inadequate specimens, aggregate specimen volume and material costs were assessed. Econometric analysis was performed to assess the relationship between materials cost and diagnostic yield. Diagnostic yield and average core specimen volume were significantly higher in the powered drill group, with 86% of cases yielding adequate biopsy specimens versus 67% of cases using the manual method. The materials cost associated with the powered drill device was higher than those of any of the manual needle devices with an average difference of $270.19 per case, however, this was offset due to higher diagnostic yield suggesting that the increased diagnostic accuracy achieved by the powered drill does not carry a significant added financial burden. The powered drill bone biopsy system results in a significantly higher yield of diagnostically adequate biopsy specimens compared to traditional manual needles, possibly attributed to larger and more intact obtained core specimen volumes and is more economically viable off-setting the higher cost.

CT-Compatible Medical Drilling Stylet

This paper describes the design of a compact, lightweight CT-compatible, drill-press that is designed to be used in either a hand-held or stand-alone mode to assist with percutaneous bone based interventions. Previous medical drilling tools that have been developed have a metal structure and typically have one actuator for advancing the drill (feed) and another for rotating it (speed). After defining the device functional requirements and specifications, a deterministic design process was followed to generate several design concepts that were then evaluated based on their ability to satisfy the functional requirements. A final concept that uses a custom screw-spline to achieve helical motion of a shaft that is attached to a standard orthopedic drill was selected for prototyping. The design uses a single actuator to drive both the screw and spline nuts through two different gear ratios, resulting in a fixed ratio between the feed and speed. Apart from the motor which is placed away from the central drill axis, the device is largely made from plastic materials. A custom experimental setup was developed that enabled drilling into bone inside a CT scanner to be examined. Results showed that the device was successfully able to penetrate thick cortical bone and that its structure did not appreciably distort the medical images.

Powered bone marrow biopsy procedures produce larger core specimens, with less pain, in less time than with standard manual devices

Bone marrow sampling remains essential in the evaluation of hematopoietic and many non-hematopoietic disorders. One common limitation to these procedures is the discomfort experienced by patients. To address whether a Powered biopsy system could reduce discomfort while providing equivalent or better results, we performed a randomized trial in adult volunteers. Twenty-six subjects underwent bilateral biopsies with each device. Core samples were obtained in 66.7% of Manual insertions; 100% of Powered insertions (P=0.002). Initial mean biopsy core lengths were 11.1±4.5 mm for the Manual device; 17.0±6.8 mm for the Powered device (P<0.005). Pathology assessment for the Manual device showed a mean length of 6.1±5.6 mm, width of 1.0±0.7 mm, and volume of 11.0±10.8 mm³. Powered device measurements were mean length of 15.3±6.1 mm, width of 2.0±0.3 mm, and volume of 49.1±21.5 mm³ (P<0.001). The mean time to core ejection was 86 seconds for Manual device; 47 seconds for the Powered device (P<0.001). The mean second look overall pain score was 33.3 for the Manual device; 20.9 for the Powered (P=0.039). We conclude that the Powered biopsy device produces superior sized specimens, with less overall pain, in less time.

Using a powered bone marrow biopsy system results in shorter procedures, causes less residual pain to adult patients, and yields larger specimens

Background

In recent years, a battery-powered bone marrow biopsy system was developed and cleared by the U.S. Food and Drug Administration to allow health care providers to access the bone marrow space quickly and efficiently. A multicenter randomized clinical trial was designed for adult patients to determine if the powered device had advantages over traditional manually-inserted needles in regard to length of procedure, patient pain, complications, user satisfaction, and pathological analysis of the specimens.

Methods

Adult patients requiring marrow sampling procedures were randomized for a Manual or Powered device. Visual Analog Scale (VAS) pain scores were captured immediately following the procedure and 1 and 7 days later. Procedure time was measured and core specimens were submitted to pathology for grading.

Results

Ten sites enrolled 102 patients into the study (Powered, n = 52; Manual, n = 50). Mean VAS scores for overall procedural pain were not significantly different between the arms (3.8 ± 2.8 for Powered, 3.5 ± 2.3 for Manual [p = 0.623]). A day later, more patients who underwent the Powered procedure were pain-free (67%) than those patients in the Manual group (33%; p = 0.003). One week later, there was no difference (83% for Powered patients; 76% for Manual patients.) Mean procedure time was 102.1 ± 86.4 seconds for the Powered group and 203.1 ± 149.5 seconds for the Manual group (p < 0.001). Pathology assessment was similar in specimen quality, but there was a significant difference in the specimen volume between the devices (Powered: 36.8 ± 21.2 mm³; Manual: 20.4 ± 9.0 mm³; p = 0.039). Two non-serious complications were experienced during Powered procedures (4%); but none during Manual procedures (p = 0.495).

Conclusions

The results of this first trial provide evidence that the Powered device delivers larger-volume bone marrow specimens for pathology evaluation. In addition, bone marrow specimens were secured more rapidly and subjects experienced less intermediate term pain when the Powered device was employed. Further study is needed to determine if clinicians more experienced with the Powered device will be able to use it in a manner that significantly reduces needle insertion pain; and to compare a larger sample of pathology specimens obtained using the Powered device to those obtained using traditional manual biopsy needles.