Yuzo Shomura

Radiological Follow-up of New Compression Fractures Following Percutaneous Vertebroplasty

The purpose of the present study was to ascertain chronological changes in the analgesic effects of percutaneous vertebroplasty (PVP) on osteoporotic vertebral compression factures and to radiologically follow new compression fractures after PVP. Seventy-six patients (206 vertebral bodies) were followed radiologically for a mean of 11.5 months. A visual analog scale (VAS; 0–10) was used to assess pain severity, and frontal and lateral plain radiographs of the thoracic and lumbar vertebrae were taken 1–3 days and 1, 4, 10, and 22 months after PVP.The average VAS score was 7.2 ± 2.0 (mean pain score ± standard deviation) before PVP, 2.5 ± 2.3 at 1–3 days after PVP, 2.2 ± 2.3 at 1 month, 1.9 ± 2.2 at 4 months, 1.8 ± 2.4 at 10 months, and 1.0 ± 0.2 at 22 months. A new compression fracture was confirmed in 56 vertebral bodies in 28 patients (36.8%), affecting 38 adjacent vertebral bodies (67.8%), 17 nonadjacent vertebral bodies (30.4%), and 1 treated vertebral body (1.8%). A new compression fracture occurred within 1 week of PVP in 2 vertebral bodies (3.6%), between 1 week and 1 month after PVP in 22 (39.3%), between 1 and 3 months in 12 (21.4%), between 3 and 6 months in 12 (21.4%), and after more than 6 months in 8 (14.3%). PVP was highly effective in relieving the pain associated with osteoporosis-induced vertebral compression fractures, and this analgesia was long lasting. Radiological follow-up observation revealed new compression fractures in about one-third of patients. More than half of these new compression fractures occurred in adjacent vertebral bodies within 3 months of PVP.

Clinical Assessment of Percutaneous Radiofrequency Ablation for Painful Metastatic Bone Tumors

PurposeTo investigate the pain-alleviating effects of radiofrequency ablation (RFA) on metastatic bone tumors in relation to tumor size, combined therapy, and percent tumor necrosis rate following RFA.MethodsSubjects comprised 24 patients with 28 painful metastatic bone tumors. A 17G internally cooled electrode was inserted into the tumor for CT guidance and ablation was performed. Bone cement was injected following RFA for 4 tumors involving a weight-bearing bone, while 5 tumors were treated using combined RFA and external irradiation. Percent necrosis rate of the tumor was measured using contrast-enhanced computed tomography 1 week after RFA.ResultsImprovement in the visual analog scale (VAS) score was 4.6 ± 2.2 for large tumors (>5 cm, n = 12), 3.7 ± 1.8 for medium-sized tumors (3.1–5.0 cm, n = 11), and 3.5 ± 1.7 for small tumors (≤3 cm, n = 4), with no significant differences noted among tumor sizes. Improvement in the VAS score was 3.5 ± 1.3 for the 4 tumors in the RFA + bone cement group, 3.2 ± 1.9 for the 5 tumors in the RFA + radiation therapy group, and 4.8 ± 2.2 for the 18 tumors in the RFA group. No significant differences were identified between groups. The improvement in the VAS score was 3.8 ± 2.3, 4.0 ± 1.9, and 4.7 ± 2.6 in patients with tumor necrosis rates of 0–49%, 50–74%, and 75–100%, respectively. No significant association was observed among these three groups.ConclusionPercutaneous RFA therapy was effective in relieving pain due to metastatic bone tumors. No relationships appear to exist between initial response and tumor size, combined therapy, and percent tumor necrosis.

Relationship Between Cement Distribution Pattern and New Compression Fracture After Percutaneous Vertebroplasty

OBJECTIVE The objective of this study was to prospectively investigate relationships between cement distribution patterns and the occurrence rates of new compression fractures after percutaneous vertebroplasty. SUBJECTS AND METHODS Percutaneous vertebroplasty was performed for osteoporotic compression fractures in 76 consecutive patients. Patients were divided into two groups according to the cement filling pattern shown on radiography and CT: cleft pattern group (group C, n = 34), compact and solid cement filling pattern in vertebrae; and trabecular pattern group (group T, n = 42), sponge-like filling pattern. A visual analog scale (VAS) was used to assess pain severity, and anterior and lateral radiographs of the thoracic and lumbar vertebrae were obtained 1-3 days and 1, 4, 10, 22, and 34 months after percutaneous vertebroplasty. Differences in treatment efficacy and the occurrence rates of new compression fractures were examined and compared for both groups using the Mann-Whitney U test and chi-square test. RESULTS A significant difference was seen between groups with respect to the volume of cement injected per vertebra (mean volume: group C, 4.5 mL; group T, 3.7 mL; p = 0.01). VAS improvement did not differ significantly between group C (4.6) and group T (4.5). The mean follow-up period was 19.5 months, during which new compression fractures were significantly more frequent in group C (17 of 34 [50%]) than in group T (11 of 42 [26.2%]; p = 0.03). CONCLUSION Although cement distribution patterns do not significantly affect initial clinical response, a higher incidence of new compression fractures is seen in patients with treated vertebrae exhibiting a cleft pattern.

Radiofrequency ablation combined with CO2 injection for treatment of retroperitoneal tumor: protecting surrounding organs against thermal injury.

OBJECTIVE The objective of this study was to separate target tumors from adjacent structures by injecting carbon dioxide (CO2) around the tumor to avoid thermal injury and the heat-sink effect from the blood vessel during percutaneous radiofrequency ablation. CONCLUSION We successfully achieved complete ablation of a retroperitoneal tumor without thermal injury. Imaging-guided percutaneous CO2 injection is useful for preventing thermal injury while achieving complete ablation of the tumor during radiofrequency ablation.

A case of spontaneous regression of hepatocellular carcinoma with multiple lung metastases.

Spontaneous regression of hepatocellular carcinoma (HCC) is a rare phenomenon. We present herein the case of a patient with hepatocellular carcinoma with multiple lung metastases in whom malignancy spontaneously regressed after takingPhellinus linteus Mycelium. A 79-year-old man consulted our hospital complaining of epigastric discomfort. Abdominal MRI and CT revealed a 3 cm diameter tumor in the liver, and chest CT showed numerous nodular lesions. The levels of alpha-fetoprotein (AFP) and protein induced by vitamin K deficiency or antagonist-II (PIVKA-II) were very high. We diagnosed HCC with multiple lung metastases, and no therapy was performed. Independently he took exact fromPhellinus linteus Mycelium for one month, and 6 months later the tumors appeared to be in complete regression. The mechanism underlying this intriguing phenomenon remains unknown.

Percutaneous Vertebroplasty for Compression Fracture: Analysis of Vertebral Body Volume by CT Volumetry

Purpose: To evaluate the relationships between volume of vertebral bodies with compression fracture (measured by CT volumetry) before percutaneous vertebroplasty, the amount of bone cement injected, and the effect of treatment. Material and Methods: We examined 49 consecutive patients, with 104 vertebral body compression fractures, who underwent percutaneous injection of bone cement. Vertebral body volume was measured by CT volumetry. The patients pain level was assessed using a visual analog scale (VAS) before and after the procedure. Improvement in VAS was defined as the decrease in VAS after the procedure. Relationships between vertebral body volume, the amount of bone cement, and the effect of treatment were evaluated using Pearsons correlation coefficient test. Results: Average vertebral body volume was 26.3±8.1 cm3; average amount of bone cement was 3.2±1.1 ml; and average improvement in VAS was 4.9±2.7. The vertebral body volume was greater if a larger amount of bone cement was injected. There was a significant positive correlation between vertebral body volume and amount of bone cement (r = 0.44; P<0.0001). However, there was no correlation between vertebral body volume and improvement in VAS, or between amount of bone cement and improvement in VAS. Conclusion: In percutaneous vertebroplasty for vertebral body compression fracture, there is a positive correlation between vertebral body volume and amount of bone cement, but improvement in VAS does not correlate with vertebral body volume or amount of bone cement.

A new bioabsorbable sleeve for staple-line reinforcement: report of a clinical experience.

AbstractPurpose. The most frequent and troublesome complication after resection of an emphysematous lung is persistent air leakage. This report describes our recent experience of using sleeves made of polyglycolic acid to reinforce staple-lines to reduce air leaks after resection of emphysematous lung. Methods. We used bioabsorbable sleeves made of polyglycolic acid (PGA) for staple-line reinforcement during lung resections in 25 patients with emphysema. Results. Immediately after stapling, no air leaks were detected in 20 patients (80%), although prolonged air leaks lasting for more than 7 days were observed in three patients (12.5%). Conclusion. PGA sleeves do not constitute a foreign body that stays in the host lung, and they require no rinsing at the time of clinical use. Therefore, the PGA sleeve could be a promising new material instead of non-absorbable materials and xenomaterials for staple-line reinforcement.

Transcatheter embolization for peripheral pseudoaneurysms with n-butyl cyanoacrylate

The purpose of this study is to evaluate the clinical efficacy of transcatheter embolization for pseudoaneurysms of peripheral arteries with n-butyl cyanoacrylate (NBCA). From November 2000 to February 2008, 17 patients with 18 pseudoaneurysms were treated by transcatheter embolization at our affiliated hospitals. The locations of the pseudoaneurysms were right hepatic artery (n=3), renal artery (n=5), splenic artery (n=2), gastroduodenal artery (n=2), common hepatic artery (n=1), pancreatic arcade (n=1), external iliac artery (n=1), internal iliac artery (n=1), internal thoracic artery (n=1), and left gastric artery (n=1). We assessed technical success rate, embolization methods, and clinical course in this study. The technical success rate was 94.4% (17/18 cases). Embolization methods were isolation (n=17) and packing (n=1). Only NBCA was used in 14 cases, both coils and NBCA were used in four cases. Six patients were in shock prior to the procedure, but all patients recovered immediately after embolization procedure including transfusion. None of the patients died of procedure-related factors or had notable postoperative complications, but three patients died within a week of the procedure because of deterioration of the underlying disease. In conclusion, transcatheter embolization of pseudoaneurysms with NBCA is a safe and effective technique for treatment.

Radiation Exposure to Operators during Vertebroplasty

PURPOSE To measure the radiation received by physicians during percutaneous vertebroplasty with use of two types of injection devices with the interventional equipment guided by computed tomography (CT) and an angiographic/CT system. MATERIALS AND METHODS Twenty consecutive patients who underwent percutaneous vertebroplasty were included in this study. The patients were divided into two groups, the 1-mL syringe group and the bone cement injector group. Percutaneous vertebroplasties were performed with the IVR-CT system, which combines angiographic and CT equipment with a single fluoroscopy table. Radiation dose to operators was measured as equivalent dose penetrating at a 10-mm tissue depth with use of electronic personal dosimeters attached outside and inside lead aprons. Effective radiation dose (HE) was estimated based on the radiation dose outside the lead apron (Ha) and the radiation dose inside the lead apron (Hb). Differences between the groups in doses and fluoroscopic duration were analyzed. RESULTS In the 1-mL syringe group and bone cement injector group, mean Ha measurements were 320.8 microSv and 116.2 microSv, respectively. Mean Hb measurements were 14.5 microSv versus 7.8 microSv and mean HE measurements were 48.2 microSv versus 19.7 microSv. Significant differences were found in Ha, Hb, and HE. However, duration of fluoroscopy did not differ significantly between groups. CONCLUSIONS Radiation dose was relatively high for operators performing percutaneous vertebroplasty. The bone cement injector was useful in reducing the level of radiation exposure to operators during vertebroplasty.

Transcatheter Coil Embolization for Steal Syndrome in Patients with Hemodialysis Access

Background: Drainage of large amounts of shunt blood into deep veins via collaterals reduces resistance to venous outflow and decreases blood flow to the artery distal to the arterial anastomotic site, potentially resulting in steal syndrome. Purpose: To evaluate the effectiveness of transcatheter coil embolization for collateral veins of hemodialysis access in the treatment of steal syndrome. Materials and Methods: Five hemodialysis patients (four male, one female; mean age 58.8 years, range 40–71 years) with symptomatic steal syndrome were treated. Steal syndrome was diagnosed based on decreased or absent distal pulse, coolness, pain, abnormal skin color, ischemic ulceration of digits, numbness, sensory impairment, or motor impairment. Coil embolization was performed to block collaterals communicating with deep veins, with conscious sedation and local anesthesia. Fistulography was performed before, immediately after, and 1 month after embolization. Ultrasonography was performed 2 days after embolization. Symptoms and signs were assessed 2 days after embolization. Clinical findings related to steal syndrome and access failure were observed at each hemodialysis. Results: Blood flow in the collaterals was successfully blocked by coil embolization in all patients. Distal pulse, coolness, pain, and skin color improved in all patients. Numbness, sensory impairment, and motor impairment were unimproved in two patients. In all patients, hemodialysis following embolization was performed normally. The mean observation period after embolization was 33 months (range 9–75 months). Conclusion: Coil embolization of collaterals that drain shunt blood into deep veins is effective for steal syndrome for hemodialysis access originating in the brachial artery.