Miyuki Nakatani

Percutaneous Vertebroplasty for Osteoporotic Compression Fractures: Long-Term Evaluation of the Technical and Clinical Outcomes

OBJECTIVE The purpose of this article is to evaluate the technical and clinical outcomes of 194 patients with 500 osteoporotic vertebral compression fractures (VCFs) consecutively treated by percutaneous vertebroplasty, to investigate the long-term efficacy of percutaneous vertebroplasty, and to determine the frequency of new VCFs after percutaneous vertebroplasty. MATERIALS AND METHODS One hundred ninety-four patients (168 women and 26 men; mean age, 73.3 years; range, 44-89 years) with 500 VCFs (T5-L5) were enrolled in this study. Evaluation at each follow-up time point (1 day, 1 month, 4 months, 1 year, and then once yearly) included pain response by using a pain visual analog scale (VAS) and frontal and lateral radiographs of the thoracic and lumbar vertebrae regardless of the symptoms. RESULTS The mean volume of cement injected was 3.3 mL (range, 0.5-12 mL) per level. Cement leakage was seen at 213 levels (42.6%). The mean follow-up time was 31 months (range, 1-97 months). The mean VAS score was 7.6 before percutaneous vertebroplasty and 3.1 at 1 day, 2.3 at 1 month, 1.7 at 4 months, 1.5 at 1 year, 1.2 at 2 years, 1.0 at 3 years, 1.1 at 4 years, 0.9 at 5 years, 0.9 at 6 years, and 1.0 at 7 years after percutaneous vertebroplasty. New VCFs were confirmed in 103 vertebrae in 65 patients (33.5%), affecting 65 adjacent vertebrae (63.1%) and 38 nonadjacent vertebrae (36.9%). CONCLUSION Percutaneous vertebroplasty was effective in relieving the pain associated with osteoporosis-induced VCFs, and the analgesic effect was long lasting when no new VCF occurred. However, radiologic follow-up observation showed that new VCFs occurred in approximately one-third of the patients.

Cement Leakage in Percutaneous Vertebroplasty for Osteoporotic Compression Fractures With or Without Intravertebral Clefts

OBJECTIVE The purpose of our study was to compare the incidence and location of cement leakage in percutaneous vertebroplasty for osteoporotic compression fractures with and without intravertebral clefts. MATERIALS AND METHODS Percutaneous vertebroplasty was performed in 120 consecutive patients with 300 osteoporotic compression fractures. The cement volume injected was recorded. The cement leakage was evaluated using spinal radiography, MRI, and fluoroscopy during the procedure and CT after the procedure. RESULTS One hundred seven vertebrae contained intervertebral clefts, and 193 vertebrae had no clefts. The cement volume injected (+/- SD) was 4.0 +/- 2.0 and 3.6 +/- 1.6 mL into vertebrae with clefts and without clefts, respectively, with no statistically significant difference (p = 0.14). There was no statistically significant difference in the incidence of cement leakage between vertebrae with clefts (53 of 107) and those without clefts (78 of 193) (p = 0.13). Leakage occurred into the epidural veins (12 of 107), perivertebral soft tissues (7 of 107), disks (41 of 107), intervertebral foramen (1 of 107), and spinal canal (1 of 107) in fractures with clefts and into the epidural veins (47 of 193), perivertebral soft tissues (13 of 193), disks (25 of 193), paravertebral veins (5 of 193), large vein (2 of 193), lung (2 of 193), intervertebral foramen (1 of 193), and spinal canal (1 of 193) in fractures without clefts. Cement leakage into the epidural vein was significantly more frequent in vertebrae without clefts (p < 0.01). Disk leakage was significantly more frequent in vertebrae with clefts compared with those without clefts (p < 0.01). CONCLUSION There was no statistically significant difference in the incidence of cement leakage between vertebrae with clefts and without clefts. However, cement leakage into the epidural vein was significantly more frequent in vertebrae without clefts and disk leakage was significantly more frequent in vertebrae with clefts.

Pancreatitis after transcatheter embolization of a splenic aneurysm

A 52-year-old woman was treated for a splenic aneurysm that was found on abdominal computed tomography (CT) during a preoperative assessment for rectal cancer. The aneurysm was embolized using the “double coil-delivered microcatheter technique,” and 4 ml of a mixture of N-butyl 2-cyanoacrylate (NBCA) and iodized oil (Lipiodol) (NBCA/Lipiodol = 1.0: 2.5) were injected into the aneurysm. The patient complained of left upper quadrant abdominal pain immediately after the procedure. A blood test 2 days after the procedure showed an increased white blood cell count (13 100/μl), C-reactive protein (13.36 mg/dl), and pancreatic amylase (428 U/l). Abdominal CT scan showed a huge cystic lesion at the pancreatic tail, in the center of which was a highly enhanced area due to accumulated NBCA-Lipiodol. Postembolization pancreatitis was diagnosed, and treatment with fasting and a drip infusion of nafamostat mesilate was started. The patient’s abdominal pain became less severe within 3 days, and the pancreatic enzyme level had normalized 14 days after treatment. On CT, the cystic lesion at the pancreatic tail was smaller 20 days after the procedure, and it had disappeared completely 75 days after the procedure.

Analysis of factors influencing accuracy and complications in CT-guided lung biopsy

Abstract Introduction: This study aimed to analyze factors influencing accuracy and complications in patients who underwent computed tomography (CT)-guided lung biopsy at our medical center. Material and methods: This study included all 107 patients (72 men, 35 women; mean age, 69 years; range, 41–83 years) who underwent CT-guided lung biopsy between January 2006 and October 2009. CT fluoroscopy was used in 45.7% of cases. Final diagnosis, when surgical resection was performed, was histopathological diagnosis from the lung lesion specimen, and when resection was not performed, clinical diagnosis after ≥6 months of follow-up. The accuracy of lung biopsy was assessed by comparison of biopsy results and final diagnosis. The influence of factors on accuracy was statistically analyzed. Results: Accuracy of CT-guided lung biopsy was 89.4%. None of the factors, including lesion size, lesion depth from pleura, lesion location, patient position, final diagnosis, and use or non-use of CT fluoroscopy, had any significant influence on accuracy. The only complications were Grade 1 and 2 pneumothorax and Grade 1 pulmonary bleeding. The incidence of pneumothorax and bleeding was significantly increased with smaller lesion size and significantly increased with greater lesion depth. In patients with pulmonary emphysema, bleeding was significantly less (p = 0.022). When CT fluoroscopy was used, bleeding was significantly increased (p < 0.001). Conclusions: None of the factors had any significant influence on accuracy. The incidence of pneumothorax and bleeding was affected by lesion size and lesion depth. When CT fluoroscopy was used, bleeding was significantly increased.

Radiation dose of nurses during IR procedures: a controlled trial evaluating operator alerts before nursing tasks.

PURPOSE To compare radiation exposure of nurses when performing nursing tasks associated with interventional procedures depending on whether or not the nurses called out to the operator before approaching the patient. MATERIALS AND METHODS In a prospective study, 93 interventional radiology procedures were randomly divided into a call group and a no-call group; there were 50 procedures in the call group and 43 procedures in the no-call group. Two monitoring badges were used to calculate effective dose of nurses. In the call group, the nurse first told the operator she was going to approach the patient each time she was about to do so. In the no-call group, the nurse did not say anything to the operator when she was about to approach the patient. RESULTS In all the nursing tasks, the equivalent dose at the umbilical level inside the lead apron was below the detectable limit. The equivalent dose at the sternal level outside the lead apron was 0.16 μSv ± 0.41 per procedure in the call group and 0.51 μSv ± 1.17 per procedure in the no-call group. The effective dose was 0.018 μSv ± 0.04 per procedure in the call group and 0.056 μSv ± 0.129 per procedure in the no-call group. The call group had a significantly lower radiation dose (P = .034). CONCLUSIONS Radiation doses of nurses were lower in the group in which the nurse called to the operator before she approached the patient.

Asymptomatic paradoxical and symptomatic pulmonary air embolism during central venous catheter insertion

A 65-year-old man developed respiratory distress during insertion of a central venous catheter (CVC). The presence of gas in the pulmonary trunk and ascending aorta was observed on computed tomography (CT) scans performed immediately after insertion, and paradoxical air embolism (PAE) was diagnosed. There were no symptoms of cerebral or coronary arterial embolism, and the patient was maintained in the same supine position as during CVC insertion. CT conducted after 200 min confirmed disappearance of the gas, and the resting position was discontinued. No subsequent symptoms of PAE occurred. In this patient with respiratory distress during CVC insertion, CT revealed PAE, and PAE was resolved and systemic arterial embolism did not occur by maintenance of the supine position and O2 administration. This case also highlights the potential risk for the occurrence of asymptomatic PAE related to CVC insertion.

Comparison of Tc-99m GSA scintigraphy and CT volumetry for evaluation in portal vein embolization.

Abstract Purpose: To determine the correlation of the rate of change of each future remnant liver (FRL) before and after portal vein embolization (PVE), by CT volumetry and Tc-99m galactosyl human serum albumin scintigraphy (GSA scintigraphy). Material and methods: From December 2007 to July 2012, ten patients underwent PVE before hepatic resection. CT volumetry and GSA scintigraphy were performed before and after PVE. The FRL was divided at Cantlies line for CT volumetry, and volume change rates before and after PVE were calculated. The maximum removal rate (Rmax) was calculated using a radiopharmacokinetic model in GSA scintigraphy. The FRL Rmax change rates before and after PVE were calculated. The correlation between the volume change rates and the Rmax change rates was analyzed. Results: The FRL volume change rate was 1.28 ± 0.26 (mean ± SD); the FRL hypertrophied in all patients significantly (p = 0.005). The FRL Rmax change rate was 1.66 ± 0.75; excluding one patient, there was significant FRL Rmax increase (p = 0.022). Although both increased significantly, no correlation between the volume change rate and the Rmax change rate was observed. Conclusion: No correlation was observed between the FRL volume rate and the Rmax rate.

Direct puncture embolization using N-butyl cyanoacrylate for a hepatic artery pseudoaneurysm

Abstract Massive hemobilia caused by hepatic artery pseudoaneurysm is an uncommon but potentially fatal complication that can occur after biliary intervention. Previous intervention or surgery, atherosclerotic disease, inflammation and even anatomic variants may make the pseudoaneurysm inaccessible to transcatheter approach, therefore it is not always feasible. The present report describes a case of successful embolization of a hepatic artery pseudoaneurysm with N-butyl cyanoacrylate via direct puncture as an alternative approach. The case presentation is followed by the technical points and the properties of N-butyl cyanoacrylate that are particularly advantageous for use in direct puncture procedures.

Portopulmonary venous anastomosis in balloon‐occluded retrograde transvenous obliteration for the treatment of gastric varices

Several reports have described portopulmonary venous anastomosis (PPVA). However, in balloon‐occluded retrograde transvenous obliteration (BRTO), attention has not been paid to paradoxical embolism. The objective of this study was to investigate the existence of a right–left shunt due to PPVA when the drainage vein is occluded by a balloon during BRTO.

Intra-arterial infusion of thrombin: Animal experiments

Abstract Purpose: Thrombin inhibits cadherin on vascular endothelial cells, rapidly and reversibly increasing endothelial permeability. The purpose of this study was to evaluate the feasibility of trans-arterial infusion with thrombin. Material and methods: Ten rabbits with right thigh tumor were randomly divided into two groups: A thrombin group and a control group. In the thrombin group, a suspension of thrombin (300 IU), cisplatin (3 mg), lipiodol (0.3 ml) and iopamidol (0.3 ml) was infused into the right femoral artery. In the control group, a suspension of cisplatin, lipiodol and iopamidol was infused. Platinum concentrations in plasma were measured five and ten minutes after administration. Platinum concentrations were also measured in tumor specimens excised 30 minutes after infusion. Results: At both five and ten minutes after infusion, platinum concentrations in plasma were significantly lower for the thrombin group than for the control group. Platinum concentration in tumor tissue was significantly higher for the thrombin group than for the control group. Conclusion: The present results suggest that transarterial infusion with thrombin may offer a number of pharmacological advantages.