Cryoneurolysis in Peripheral Neuropathic Pain

Neuropathic pain is a growing problem as the population ages and the prevalence of diabetes increases. Multiple methods of have been employed to treat neuropathic pain, including medical therapies, local anesthetics, and more invasive procedures such as spinal cord stimulators and neurolysis. Investigators from SUNY Stony Brook evaluated the use of ultrasound guided cryotherapy in this difficult patient population. Patients were selected based on inclusion criteria such as: failure of a first or second line therapy, evaluation by a pain physician before initiating therapy, and a history of response to nerve blocks. Exclusion criteria included an inability to participate in follow up assessments of pain levels. In total, 22 patients underwent ablation and were followed at 1 week and 1, 3, 6, 9, and 12 month intervals. Of these patients, 11 required repeat cryoneurolysis within 12 months of the initial procedure. The average pain score before treatment was 8.3 +/- 1.9. Pain scores after treatment were 2.3 +/- 2.5 at 1 month, 3.2+/- 2.5 at 3 months, 4.7 +/- 2.7 at 6 months, and 5.1 +/- 3.7 at 12 months. In addition to these findings, the study concluded that the regeneration of the treated nerve was related to ablation time. For example, authors found that 1 minute of ablation time corresponded to 1 month of time for nerve regeneration.

Commentary:

This study presents cryotherapy as an effective and safe alternative to other treatment methods for neuropathic pain. This technique provides statistically significant pain relief for the patients at every time point examined. Additional studies will be required for further evaluation of this technique, including future prospective studies to determine optimal ablation time and treatment intervals. Although the study is limited by sample size, number of ablations during the evaluation period, and concomitant pain management therapy, the results are quite promising given the positive response to therapy and the superior safety profile of cryoneurolysis compared to alternative invasive therapies for the treatment of neuropathic pain.




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Yoon JHE, Grechushkin V, Chaudry A, Bhattacharji P, Durkin B, Moore W. Cryoneurolysis in Patients with Refractory Chronic Peripheral Neuropathic Pain. J Vac Interv Radiol 2016; 27:239-243.

Post Author:
Brian Gardner, MD
VIR Pathway Resident at University of Virginia

We Never Claimed to Be Accountants: Survey of Interventional Radiologists and Vascular Surgeons Regarding the Cost and Reimbursement of Common Devices and Procedures

With US healthcare spending projected to exceed $5 trillion by 2022, there is new emphasis on the physician’s role in decreasing healthcare costs. This study quantified the abilities of Interventional Radiologists and Vascular Surgeons to estimate the prices of devices and reimbursement for procedures. All members of the Society of Interventional Radiology and the Society of Vascular Surgery were invited to participate in an online survey asking the physician to estimate the average retail price of 15 devices commonly used in both specialties as well as specialty-specific questions regarding average Medicare procedural reimbursement rates and procedure relative value units. The answers were given in a fill-in-the-blank format and an answer was scored as correct if it was within 25% of the actual dollar amount. Approximately 22 % of those surveyed responded, and the analysis showed that Vascular Surgeons (VS) and Interventional Radiologists (IR) were very similar in their knowledge of device cost, with about 20% of responses falling within the correct range. Across both specialties, more accurate cost estimations were correlated with years of experience, private practice work environment and area of practice with the plausible explanation that physicians with more cost exposure in their practice are likely to be more familiar with how their hospitals negotiate contracts for device-related and procedure-related costs.

Commentary:

Containing healthcare costs is a critically important issue facing the US healthcare system - one that will only become more important as policymakers modify reimbursements and bundle payments to incentivize the judicious use of medical equipment. While data collection via voluntary survey is inherently limited by bias, the 22% response rate in this study is a very good yield. While it is not surprising that physicians with more experience and cost exposure are better at estimating costs, it is surprising and concerning that the overall accuracy rate was only 20% across both IR and VS. The study points out that nearly all of the surveyed physicians would choose to utilize less expensive tools if they knew the cost, but only a quarter of the respondents felt they had adequate access to hospital pricing. If the goal is to practice cost-conscious spending, then understanding the costs of basic tools is a logical first step. The study nicely discusses possible explanations for this disconnect and postulates that a lack of transparency at the hospital purchasing level may play a significant role in some healthcare systems. Additionally, device cost and procedure reimbursement is not an emphasized milestone in most training programs. Physician education and purchasing transparency is a prime area for further study and evaluation as a means to control spiraling healthcare costs.

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Wang A, Dybul SL, Patel OJ, Tutton SM, Lee CJ, White SB. A cross-sectional survey of interventional radiologists and vascular surgeons regarding the cost and reimbursement of common devices and procedures. J Vasc Interv Radiol 2016; 27: 210-218.

Post Author:
John T. Cardella, MD
VIR Fellow, University of Virginia

Physician self-regard benefits patients’ radiation exposure: real-time monitoring of patient and occupational dose

There has been increasing emphasis on quality improvement throughout radiology departments. Radiation exposure to both the patient and the operator is one important aspect of this. This prospective study evaluated the effects of dose to patients and operators when employing real time dose monitoring of both patients and operators during fluoroscopic procedures.

Two experienced operators were enrolled in this study. These operators performed 730 procedures during the study (720 included for analysis) which was subdivided into two discreet periods. In the first period, real time monitoring of patient dose was performed using the DoseWatch (GE Healthcare Systems, Buc, France) program. In the second period, both the patient dose and operator dose were recorded in real time. Operator dose was recorded via four individual wireless devices (Ray-Safe i2; Unfors RaySafe, Inc, Billdal, Sweden). During both periods operator dose was recorded with a thermoluminescent dosimeter. Data was available real time, for the patient dose in the control room with alarms for certain thresholds, and for the operator dose on a touch screen in the procedure room with color coded dose rates and cumulative doses. Comparison of kerma area product (KAP) for each procedure type was then made between the two study periods. Mean KAP was significantly lower in period 2 (37 mGy · cm²) compared to period 1 (47 mGy · cm²), and this held true for 15/19 of the procedure types performed. In addition, a direct correlation was observed between patient dose and occupational dose (r = 0.88). From period 2, it was observed that the mean dose per procedure was 4.6 µSv, with a dose rate of 0.24 mSv/hr.

Commentary:

This study demonstrates real time monitoring of patient and occupational dose results in decreased KAP when compared to monitoring patient dose alone. This study’s most noticeable confounding variable is its susceptibility to the Hawthorne effect, as both operators were aware of the two ongoing study periods. In addition, while there was a direct correlation between KAP and accumulated operator dose, no direct measure of operator dose per procedure was performed during the first study period. Lastly, KAP had a poor correlation with operator dose at low exposure levels. However, given the significant differences observed between the two study periods, the results are noteworthy. It would be interesting to see this tool implemented in our residency and fellowship programs to more effectively teach our trainees the benefits of radiation safety.





Figure 2. Correlation between KAP (Gy ∙ cm2) and dose to operator. Overall, there was a strong correlation of KAP, measured with the patient dose monitoring system, and accumulated equivalent dose per intervention (μSv), registered with the real-time occupational dose monitoring system. However, correlation in low-dose areas (KAP < 10 Gy ∙ cm2) was poor.

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Heilmaier, C. et al. Combined use of a patient dose monitoring system and a real-time occupational dose monitoring system for fluoroscopically guided interventions. J Vasc Interv Radiol 2016; 10.1016/j.jvir.2015.11.033.

Post Author:
Daniel Sheeran, MD
VIR Pathway Resident at University of Virginia