Gilbert Y. Wong

Percutaneous Image-Guided Radiofrequency Ablation of Painful Metastases Involving Bone: A Multicenter Study

PURPOSE Few options are available for pain relief in patients with bone metastases who fail standard treatments. We sought to determine the benefit of radiofrequency ablation (RFA) in providing pain relief for patients with refractory pain secondary to metastases involving bone. PATIENTS AND METHODS Thirty-one US and 12 European patients with painful osteolytic metastases involving bone were treated with image-guided RFA using a multitip needle. Treated patients had > or = 4/10 pain and had either failed or were poor candidates for standard treatments such as radiation or opioid analgesics. Using the Brief Pain Inventory-Short Form, worst pain intensity was the primary end point, with a 2-unit drop considered clinically significant. RESULTS Forty-three patients were treated (median follow-up, 16 weeks). Before RFA, the mean score for worst pain was 7.9 (range, 4/10 to 10/10). Four, 12, and 24 weeks following treatment, worst pain decreased to 4.5 (P <.0001), 3.0 (P <.0001), and 1.4 (P =.0005), respectively. Ninety-five percent (41 of 43 patients) experienced a decrease in pain that was considered clinically significant. Opioid usage significantly decreased at weeks 8 and 12. Adverse events were seen in 3 patients and included (1) a second-degree skin burn at the grounding pad site, (2) transient bowel and bladder incontinence following treatment of a metastasis involving the sacrum, and (3) a fracture of the acetabulum following RFA of an acetabular lesion. CONCLUSION RFA of painful osteolytic metastases provides significant pain relief for cancer patients who have failed standard treatments.

Preoperative antiplatelet therapy does not increase the risk of spinal hematoma associated with regional anesthesia

One thousand orthopedic procedures in 924 patients given spinal or epidural anesthesia were prospectively studied to determine the risk of hemorrhagic complications associated with regional anesthesia.A history of excessive bruising or bleeding was elicited in 115 (12%) patients. Preoperative antiplatelet medications were taken by 386 (39%) patients. Aspirin was the most frequently reported antiplatelet drug and was taken by 193 patients. Subcutaneous heparin was administered to 22 patients before surgery on the operative day. One patient of 774 tested had a preoperative platelet count less than 100,000/mm.3 In addition, 26 of 171 preoperative prothrombin times and 10 of 115 preoperative activated partial thromboplastin times were longer than normal. Only 31 preoperative bleeding times were performed; five were prolonged. There were no documented spinal hematomas (major hemorrhagic complications). Blood was noted during needle or catheter placement (minor hemorrhagic complication) in 223 (22%) patients, including 73 patients with frank blood in the needle or catheter. Preoperative antiplatelet therapy did not increase the incidence of minor hemorrhagic complications. However, female gender, increased age, a history of excessive bruising/bleeding, surgery to the hip, continuous catheter anesthetic technique, large needle gauge, multiple needle passes, and moderate or difficult needle placement were all significant risk factors. The lack of correlation between antiplatelet medications and bloody needle or catheter placement (producing clinically insignificant collections of blood in the spinal canal or epidural space) is strong evidence that preoperative antiplatelet therapy is not a significant risk factor for the development of neurologic dysfunction from spinal hematoma in patients who undergo spinal or epidural anesthesia while receiving these medications. (Anesth Analg 1995;80:303-9)

Efficacy of gabapentin in the management of chemotherapy-induced peripheral neuropathy: A phase 3 randomized, double-blind, placebo-controlled, crossover trial (N00C3)

The antiepileptic agent, gabapentin, has been demonstrated to relieve symptoms of peripheral neuropathy due to various etiologies. On the basis of these data, a multicenter, double‐blind, placebo‐controlled, crossover, randomized trial was conducted to evaluate the effect of gabapentin on symptoms of chemotherapy‐induced peripheral neuropathy (CIPN).

Intravenous paclitaxel administration in the rat induces a peripheral sensory neuropathy characterized by macrophage infiltration and injury to sensory neurons and their supporting cells.

Paclitaxel-induced peripheral neuropathy (PN) can be a significant problem for patients receiving chemotherapeutic regimens for the treatment of breast, ovarian, and lung cancer as PN can influence the quality of life and survivorship in these patients. To begin to understand the cellular changes that occur within the peripheral and central nervous system as PN develops, we intravenously infused rats with clinically relevant doses of paclitaxel. Ten days later, behavioral changes indicative of PN became evident that included mechanical allodynia, cold hyperalgesia, and deficits in ambulation/coordination. These behaviors were accompanied by increased expression of activating transcription factor 3 (ATF3; a marker of cellular injury) in a population of large>medium>small diameter sensory neurons, a population of satellite cells in the lumbar dorsal root ganglia (DRG) and in myelinating Schwann cells in the sciatic nerve. In addition, there was an increase in the expression of glial fibrillary acidic protein (GFAP) in DRG satellite cells and an increase in the number of CD68 positive activated macrophages within the DRG and peripheral nerve. Within lamina III-IV of the lumbar spinal cord, there was an increase in OX42 positive microglia. These data suggest that intravenous infusion of paclitaxel induces a peripheral neuropathy characterized by injury of neuronal and non-neuronal cells in the peripheral nervous system, macrophage activation in both the DRG and peripheral nerve, and microglial activation within the spinal cord. An understanding of the factors involved in the development and maintenance of PN may lead to mechanism based therapies that prevent/treat PN and thus improve the survival and quality of life of patients receiving chemotherapy.

Efficacy of lamotrigine in the management of chemotherapy-induced peripheral neuropathy: a phase 3 randomized, double-blind, placebo-controlled trial, N01C3.

Lamotrigine, an antiepileptic agent, has been reported as being effective in reducing symptoms of neuropathy associated with various etiologies. Based on such data, a multicenter double‐blind, placebo‐controlled, randomized trial was conducted to evaluate the effect of lamotrigine on pain and other neuropathic symptoms due to chemotherapy‐induced peripheral neuropathy (CIPN).

Infraclavicular brachial plexus block: parasagittal anatomy important to the coracoid technique.

Infraclavicular brachial plexus block is a technique well suited to prolonged continuous catheter use.We used a coracoid approach to this block to create an easily understood technique. We reviewed the magnetic resonance images of the brachial plexus from 20 male and 20 female patients. Using scout films, the parasagittal section 2 cm medial to the coracoid process was identified. Along this oblique section, we located a point approximately 2 cm caudad to the coracoid process on the skin of the anterior chest wall. From this point, we determined simulated needle direction to contact the neurovascular bundle and measured depth. At the skin entry site, the direct posterior insertion of a needle will make contact with the cords of the brachial plexus where they surround the second part of the axillary artery in all images. The mean (range) distance (depth along the needle shaft) from the skin to the anterior wall of the axillary artery was 4.24 +/- 1.49 cm (2.25-7.75 cm) in men and 4.01 +/- 1.29 cm (2.25-6.5 cm) in women. Hopefully, this study will facilitate the use of this block. Implications: We sought a consistent, palpable landmark for facilitation of the infraclavicular brachial plexus block. We used magnetic resonance images of the brachial plexus to determine the depth and needle orientation needed to contact the brachial plexus. Hopefully, this study will facilitate the use of this block. (Anesth Analg 1998;87:870-3)

The clinical significance of quality of life assessments in oncology: a summary for clinicians

BackgroundA series of six manuscripts with an introduction appeared in the Mayo Clinic Proceedings, based upon the collective effort of 30 individuals with an interest and expertise in assessing the clinical significance of quality of life (QOL) assessments. The series of manuscripts described the state of the science of QOL assessments in oncology clinical research and practice and included extensive literature and theoretical justification for the continued inclusion of QOL in oncology clinical research and practice.ObjectivesThe purpose of this paper is to produce a summary of these articles and to supplement these works with additional information that was gleaned from subsequent meetings and discussions of this material. The primary aim of this paper is to present a cogent and concise description for clinicians to facilitate the incorporation of QOL assessments into oncology clinical research and practice. The theoretical discussion is supplemented with an example of how the various ideas can be operationalized in an oncology clinical trial.

Precision of Health-Related Quality-of-Life Data Compared With Other Clinical Measures

To many clinicians, the assessment of health-related quality of life (HRQL) seems more art than science. This belief is due in part to the lack of formal training available to clinicians regarding HRQL measurement and interpretation. When HRQL is used systematically, it has been shown to improve patient-physician communication, clinical decision making, and satisfaction with care. Nevertheless, clinicians rarely use formal HRQL data in their practices. One major reason is unfamiliarity with the interpretation and potential utility of the data. This unfamiliarity causes a lack of appreciation for the reliability of data generated by formal HRQL assessment and a tendency to regard HRQL data as having insufficient precision for individual use. This article discusses HRQL in the larger context of health indicators and health outcome measurement and is targeted to the practicing clinician who has not had the opportunity to understand and use HRQL data. The concept and measurement of reliability are explained and applied to HRQL and common clinical measures simultaneously, and these results are compared with one another. By offering a juxtaposition of common medical measurements and their associated error with HRQL measurement error, we note that HRQL instruments are comparable with commonly used clinical data. We further discuss the necessary requirements for clinicians to adopt formal, routine HRQL assessment into their practices.

Patient, clinician, and population perspectives on determining the clinical significance of quality-of-life scores

Despite the success of screening and treatment of major cancers in the United States, cancer remains a chronic condition dominated by symptoms and treatment-related adverse effects. Because of these often taxing symptoms and adverse effects, numerous studies have been conducted to document the effects of cancer diagnosis and treatment on the quality of life (QOL) of patients. But there has been limited investigation of the clinical significance of QOL scores. This article examines the clinical significance of QOL scores from 3 key perspectives: patients, clinicians, and the general population. The patients perspective includes an evaluation of the size of difference in scores that individual patients can detect and regard as important. The clinician perspective relies on whether the clinician believes the patients condition has stayed the same vs whether changes have occurred (decline or improvement). The population perspective represents a democratic process in which the input or votes of a community of people are used to determine if health state A is clinically significantly different from health state B. While many clinicians and researchers advocate for QOL to be defined from the patients perspective, the reality is that QOL is often defined by clinicians in terms of observable events. Even when measures are used in which the patient identifies how his or her life has been affected, it is often the clinician who interprets the clinical importance of this information. The clinicians perspective has value in framing an experience within the context of what is usual for a group of individuals, and the population perspective provides inputs as to how society may use limited resources. However, we conclude that a more prominent role for the patients QOL perspective is needed.

Risk of surgery and anesthesia for ischemic stroke.

Background The goal of this study was to determine if the combination of surgery and anesthesia is an independent risk factor for the development of incident (first-time) ischemic stroke. Methods All residents of Rochester, MN, with incident ischemic stroke from 1960 through 1984 (1,455 cases and 1,455 age- and gender-matched controls) were used to identify risk factors associated with ischemic stroke. Cases and controls undergoing surgery involving general anesthesia or central neuroaxis blockade before their stroke/index date of diagnosis were identified. A conditional logistic regression model was used to estimate the odds ratio of surgery and anesthesia for ischemic stroke while adjusting for other known risk factors. Results There were 59 cases and 17 controls having surgery within 30 days before their stroke/index date. After adjusting for previously identified risk factors, surgery within 30 days before the stroke/index date (perioperative period) was found to be an independent risk factor for stroke (P < 0.001; odds ratio, 3.9; 95% confidence interval, 2.1–7.4). In an analysis that excluded matched pairs where the case and/or control underwent surgery considered “high risk” for stroke (cardiac, neurologic, or vascular procedures), “non–high-risk surgery” was also found to be an independent risk factor for perioperative stroke (P = 0.002; odds ratio, 2.9; 95% confidence interval, 1.5–5.7). Conclusion Our results suggest that there is an increased risk of ischemic stroke in the 30 days after surgery and anesthesia. This risk remains elevated even after excluding surgeries (cardiac, neurologic, and vascular surgeries) considered to be high risk for ischemic stroke.