Impact of neurally mediated antidiuretic effect relative to pressure diuresis during acute changes in sympathetic nerve activity.

We examined urine excretion during primary acute sympathetic activation (PASA) in anesthetized Wistar-Kyoto rats. Since arterial pressure (AP) changes with sympathetic nerve activity (SNA) during PASA, urine excretion reflects a neurally mediated antidiuretic effect combined with an effect of pressure diuresis. We hypothesized that preventing AP changes under PASA would enable the direct estimation of the neurally mediated antidiuretic effect alone. We changed the isolated carotid sinus pressure stepwise from 60 to 180 mmHg and compared the relationship of normalized urine flow (nUF, urine flow normalized by body weight) versus SNA between conditions allowing and preventing baroreflex-mediated changes in the mean AP. The slope of the SNA-nUF relationship was [Formula: see text]nUFvar = 0.444 ± 0.074 µL·min-1·kg-1·%-1 when the mean AP was variable, whereas it was [Formula: see text]nUFfix = -0.143 ± 0.032 µL·min-1·kg-1·%-1 when the mean AP was fixed at 100 mmHg (n = 7 rats). The slope associated with the effect of pressure diuresis alone, calculated as [Formula: see text]nUFvar - [Formula: see text]nUFfix, was 0.586 ± 0.105 µL·min-1·kg-1·%-1. Hence, the potency of the neurally mediated antidiuretic effect |[Formula: see text]nUFfix|/([Formula: see text]nUFvar - [Formula: see text]nUFfix) was 0.235 ± 0.014 relative to the effect of pressure diuresis under PASA. Our findings would aid an integrative understanding of the effects of renal hemodynamic and sympathetic modulations on urine output function.

Angiotensin II inhibition increases diuresis during acute sympathetic activation in intact and denervated kidneys in rats with chronic myocardial infarction.

We examined urine excretion during primary acute sympathetic activation (PASA) in Wistar-Kyoto rats with myocardial infarction (MI). The rats underwent unilateral renal denervation (RDN) 7 weeks after coronary artery ligation. 4-10 days later, an acute experiment was performed under anesthetized conditions (n = 8 rats). Isolated carotid sinus pressure was changed stepwise from 60 to 180 mmHg, and the relationship between the arterial pressure (AP) and the normalized urine flow (nUF, urine flow normalized by the body weight) was examined. After obtaining the control data, an angiotensin II type 1 receptor blocker telmisartan (2.5 mg/kg) was intravenously administered. The effects of RDN, telmisartan, and heart weight (biventricular weight) on the relationship between AP and nUF were examined using multiple regression analyses. Regarding the slope of nUF versus AP (nUFslope), the constant term of the regression was positive (0.315 ± 0.069 µL·min-1·kg-1·mmHg-1), indicating that nUF increased with AP. The heart weight had a negative effect on nUFslope (P < 0.05), suggesting that the severity of MI was associated with the impairment of urine excretion. Telmisartan increased nUFslope by 0.358 ± 0.080 µL·min-1·kg-1·mmHg-1 (P < 0.001), whereas RDN had no significant effect on this parameter. The results indicate that unilateral RDN was unable to abolish the effect of the renin-angiotensin system on urine excretion during PASA. Circulating or locally produced angiotensin II, rather than ongoing renal sympathetic nerve activity, played a dominant role in the impairment of urine excretion during PASA in rats with chronic MI.

Open-loop analysis on sympathetically mediated arterial pressure and urine output responses in spontaneously hypertensive rats: effect of renal denervation.

Primary acute sympathetic activation (PASA) causes a subsequent arterial pressure (AP) elevation. In this case, an antidiuretic effect via the renal innervation and pressure diuresis can act antagonistically on the kidneys. We examined the effect of PASA on urine output in spontaneously hypertensive rats (SHR) 4-7 days after unilateral renal denervation (RDN) (n = 9). The slope of the plot of urine flow versus AP was positive (0.120 ± 0.031 µL min-1 kg-1 mmHg-1) on the intact side, but it was less than 1/3 of the slope observed previously in normotensive Wistar-Kyoto rats (WKY). RDN did not normalize the slope of urine flow versus AP (0.179 ± 0.025 µL min-1 kg-1 mmHg-1, P = 0.098 versus the intact side). The urine flow at the operating point of the AP tended to be greater on the denervated than the intact side (29.0 ± 1.8 vs. 25.3 ± 1.9 µL min-1 kg-1, P = 0.055). The percent increase (17.2 ± 7.2%) was not different from that observed previously in WKY. Although high-resting sympathetic nerve activity is prerequisite for maintaining hypertension in SHR, the effect of sympathetic innervation on the urine output function was not greater than that in WKY.

Open-loop analysis on sympathetically mediated arterial pressure and urine output responses in rats: effect of renal denervation.

Primary acute sympathetic activation (PASA) can increase arterial pressure (AP). Under this situation, the kidneys may receive mutually opposing influences from sympathetic activation: a direct anti-diuretic effect via the renal innervation and pressure diuresis. We examined whether PASA would reduce urine output regardless of the AP elevation. We also examined the impact of renal denervation (RDN) on urine output during PASA. The experiment was performed on rats 3 to 9 days after unilateral RDN (n = 10). Under anesthesia, systemic sympathetic nerve activity (SNA) was varied over a wide range via the carotid sinus baroreflex. The slope of urine flow versus SNA was positive (0.252 ± 0.052 µL·min-1·kg-1· %-1) on the intact side, and it was greater on the denervated side (0.331 ± 0.069 µL·min-1·kg-1· %-1, P < 0.05). In conclusion, urine output change was an effect of elevated AP during PASA. Nevertheless, RDN was able to augment pressure diuresis during PASA.

Inorganic polyphosphate enhances radio-sensitivity in a human non-small cell lung cancer cell line, H1299.

Inorganic polyphosphate is a linear polymer containing tens to hundreds of orthophosphate residues linked by high-energy phosphoanhydride bonds. Polyphosphate has been recognized as a potent anti-metastasis reagent. However, the molecular mechanism underlying polyphosphate action on cancer cells is poorly understood. In this study, we investigated the involvement of polyphosphate in radio-sensitivity using a human non-small cell lung cancer cell line, H1299. We found that polyphosphate treatment decreases cellular adenosine triphosphate levels, suggesting a disruption of energy metabolism. We also found that the induction of DNA double-strand breaks was enhanced in polyphosphate-treated cells after X-ray irradiation and colony formation assay revealed that cell survival decreased compared with that of the control groups. These findings suggest that polyphosphate is a promising radio-sensitizer for cancer cells. Therefore, we hypothesized that polyphosphate treatment disrupts adenosine triphosphate-mediated energy transfer for cellular survival and DNA repair, thereby reducing the cellular capability to resist X-ray irradiation.

The effect of radiation exposure on multidrug resistance: in vitro and in vivo studies using non-small lung cancer cells.

BACKGROUND: Technetium-99m methoxyisobutylisonitrile (Tc MIBI) is a substrate with the same uptake kinetics as doxorubicin. Multidrug resistance (MDR) is a mechanism that impedes chemotherapy of non-small cell lung cancer (NSCLC). We examined the effect of radiation exposure on MDR in NSCLC and the synergy between an MDR modulator, GG918, and radiation, using (99m)Tc MIBI in vitro and doxorubicin in vivo. METHODS: In vitro NSCLC cells (H1299) were exposed to radiation (3-, 6-, and 9-Gy-irradiated groups) alongside a not-irradiated (0 Gy) group. Technetium-99 metastable methoxyisobutylisonitrile ((99m)Tc MIBI) was administered to cell suspensions at 48 h after irradiation. Cell radioactivity was measured, and C in/C out ratios were calculated and compared. NSCLC cells were also subcutaneously transplanted into the left thigh of nude mice, which were subsequently raised for 2 weeks. Two groups of mice were used: mice exposed to irradiation (9-Gy-irradiated) and those that were not (not-irradiated). Doxorubicin was administered through the caudal vein at 48 h after the irradiation. Using an in vivo imaging system, intratumoural photon counts were measured. To determine the synergy between the MDR modulator and 3- or 6-Gy irradiation, the final GG918 concentration was determined: 0.1 µM (N-H, 3-H, and 6-H groups), 0.001 µM (N-L, 3-L, and 6-L groups), and 0 µM (N-0, 3-0, and 6-0 groups). C in/C out ratios were calculated and compared among the groups. RESULTS: C in/C out after 6- or 9-Gy irradiation was significantly higher than that of the not-irradiated group (0 Gy). In vivo, fluorescence photon counts were significantly higher in the tumours of 9-Gy-irradiated mice, up to 270 min after administration of doxorubicin, as compared to the not-irradiated mice. The C in/C out ratio in the N-H, 3-H, and 6-H groups was significantly higher than that in the N-0, 3-0, and 6-0 groups. There was no significant difference between C in/C out in the N-L group and that of the N-0 group. However, the C in/C out ratio in the 3-L and 6-L groups was significantly higher than that in the 3-0 and 6-0 groups. CONCLUSIONS: Irradiation decreased MDR in NSCLC cells. In combination with a low-dose MDR modulator, GG918, MDR transport function was synergistically reduced 48 h post-irradiation.

Diffusion-weighted echo-planar imaging of the head and neck using 3-T MRI: Investigation into the usefulness of liquid perfluorocarbon pads and choice of optimal fat suppression method.

PURPOSE: To investigate whether image quality can be improved using liquid perfluorocarbon pads (Sat Pad) and clarify the optimal fat-suppression method among chemical shift selective (CHESS), water excitation (WEX), and short TI inversion recovery (STIR) methods in diffusion-weighted imaging (DWI) of the head and neck using 3-T magnetic resonance imaging. Correlations between results of visual inspection and quantitative analysis were also examined. MATERIAL AND METHODS: This study was approved by our Institutional Review Board and informed consent was waived. DWI was performed on 25 subjects with/without Sat Pad and using three fat-suppression methods (6 patterns). Image quality was evaluated visually (4-point scales and lesion-depiction capability) and by quantitative analysis (signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR)). Two-way repeated-measures analysis of variance (ANOVA) was used to detect significant differences in scores of visual evaluation, SNR, and CNR. RESULTS: Mean visual evaluation scores were significantly higher with Sat Pad using STIR than without Sat Pad for all fat-suppression methods (P<0.05). DWI with Sat Pad using STIR tended to be useful for depicting lesions. DWI using STIR showed reduced W-SNR (W: whole area of depicted structure) and CNR (between semispinalis capitis muscle and subcutaneous fat) due to fewer artifacts and uniform fat suppression. CONCLUSION: Combining Sat Pad with STIR provides good image quality for visual inspections. When numerous artifacts are present and fat suppression is insufficient, higher SNR and CNR do not always provide good diagnostic image quality.

Detection of Portal Vein Stenosis by Technetium-99m-Diethylenetriaminepentaacetic Acid-Galactosyl Human Serum Albumin Liver Scintigraphy after Living-Donor Liver Transplantation.

BACKGROUND/AIM: To investigate portal vein stenosis after living-donor liver transplantation by liver scintigraphy. METHODOLOGY: A 63-year-old woman with hepatic cirrhosis due to autoimmune hepatitis underwent living-donor liver transplantation using a graft donated by her daughter. Technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin (Tc-99m-GSA) scintigraphy was used to determine the maximum rate of Tc-99m-GSA removal (GSA-Rmax) by hepatocytes, as a parameter of hepatic functional reserve. RESULTS: Conventional liver function parameters on laboratory tests and graft volume on computed tomography (CT) were almost unchanged at postoperative month (POM) 12. GSA-Rmax was 0.11 mg/min before surgery and increased 5-fold to approximately 0.5 mg/min at POM 1 and 3, followed by a decrease to 0.25 mg/min at POM 6 and 12. Enhanced CT did not detect blood flow in the intra- or extrahepatic portions of the portal vein at POM 12. The portal vein stenosis was dilated with a balloon catheter, followed by deployment of a self-expanding stent across the stenotic segment via the transileocolic vein. GSA-Rmax recovered to 0.5 mg/min at POM 15, and subsequently remained high. CONCLUSIONS: Decreased GSA-Rmax at POM 6 indicated that the portal vein stenosis was affecting graft function. Tc-99m-GSA liver scintigraphy may be a useful noninvasive method for evaluation of graft functional reserve.

Serum concentration of fentanyl during conversion from intravenous to transdermal administration to patients with chronic cancer pain.

BACKGROUND: To the best of our knowledge, there have been no reports on the pharmacokinetics and pharmacodynamics during the conversion from continuous intravenous infusion (CII) to transdermal fentanyl administration. The primary objective of the present study was to clarify the pharmacokinetic characteristics during this conversion. A secondary objective was to identify an association between serum albumin and the absorption of fentanyl from the transdermal patch. METHODS: A prospective study was conducted from February 2010 to August 2011 that enrolled 19 patients with chronic cancer pain. Patients were classified into 2 study groups according to body mass index and albumin level. All patients received the conversion from CII to transdermal fentanyl using a 2-step taper of CII over 6 hours. Comparisons of efficacy, toxicity, and serum fentanyl concentrations between study groups were analyzed at baseline, 3, 6, 9, 12, 15, 18, and 24 hours after initiation of the conversion. RESULTS: The dose-adjusted serum fentanyl concentrations for all patients were significantly decreased at 15 to 24 hours after conversion compared with baseline, although pain intensity and the number of rescue events remained stable during the conversion. The dose-adjusted serum fentanyl concentrations at 9 to 24 hours were significantly reduced in the low albumin group compared with the normal albumin group (P<0.05). CONCLUSIONS: Our study demonstrated that the dose-adjusted serum fentanyl concentrations remained relatively stable, and pain intensity and the number of rescue events remained stable during conversion. Hypoalbuminemia was strongly associated with poor absorption of transdermally administered fentanyl.

An investigation of the early detection of radiation induced apoptosis by 99mTc-Annexin V and 201thallium-chloride in a lung cancer cell line.

This study aims to investigate the efficacy of in vitro Thallium-201 Chloride (Tl-201) and in vitro and in vivo Tc-99m HYNIC-coupled Annexin V (TAV) in the early detection of radiation induced apoptosis, a proxy indicator of radiation therapy (RT) efficacy. In vitro Tl-201 and TAV accumulation and efflux in non-small cell lung cancer were measured post irradiation at 5 different gamma ray doses. The replication rates (RR) of the cell lines were also measured. The same non-small cell lung cancer line was inoculated into the left femur. In vivo non-invasive Tl-201 and TAV tracer biodistribution studies were performed. Cell RR decrease with increased radiation dose was observed 48 hours after irradiation. Apoptotic cell number was found to have increased in response to 9 Gy and 12 Gy radiation dose. Tl-201 accumulation in the 9 Gy and 12 Gy irradiation groups was found to be higher than the lower irradiation groups. Quick Tl-201 efflux was observed in the 9 Gy and 12 Gy irradiated cells. At 48 hours after irradiation with 9 Gy and 12 Gy, Annexin V accumulation was found to be higher than in the control and 3-6 Gy groups. In vivo mouse model confirmed the increased TAV uptake in implanted tumors for relatively high 9 Gy irradiation as compared to non-irradiated controls. TAV may prove to be an effective radiotracer for early assessment of radiation therapy efficacy, via apoptosis, in human lung cancers.

Does vertebroplasty affect radiation dose distribution?: comparison of spatial dose distributions in a cement-injected vertebra as calculated by treatment planning system and actual spatial dose distribution.

Purpose. To assess differences in dose distribution of a vertebral body injected with bone cement as calculated by radiation treatment planning system (RTPS) and actual dose distribution. Methods. We prepared two water-equivalent phantoms with cement, and the other two phantoms without cement. The bulk density of the bone cement was imported into RTPS to reduce error from high CT values. A dose distribution map for the phantoms with and without cement was calculated using RTPS with clinical setting and with the bulk density importing. Actual dose distribution was measured by the film density. Dose distribution as calculated by RTPS was compared to the dose distribution measured by the film dosimetry. Results. For the phantom with cement, dose distribution was distorted for the areas corresponding to inside the cement and on the ventral side of the cement. However, dose distribution based on film dosimetry was undistorted behind the cement and dose increases were seen inside cement and around the cement. With the equivalent phantom with bone cement, differences were seen between dose distribution calculated by RTPS and that measured by the film dosimetry. Conclusion. The dose distribution of an area containing bone cement calculated using RTPS differs from actual dose distribution.

Recursive partitioning analysis for new classification of patients with esophageal cancer treated by chemoradiotherapy.

BACKGROUND: The 7th edition of the American Joint Committee on Cancer staging system does not include lymph node size in the guidelines for staging patients with esophageal cancer. The objectives of this study were to determine the prognostic impact of the maximum metastatic lymph node diameter (ND) on survival and to develop and validate a new staging system for patients with esophageal squamous cell cancer who were treated with definitive chemoradiotherapy (CRT). METHODS: Information on 402 patients with esophageal cancer undergoing CRT at two institutions was reviewed. Univariate and multivariate analyses of data from one institution were used to assess the impact of clinical factors on survival, and recursive partitioning analysis was performed to develop the new staging classification. To assess its clinical utility, the new classification was validated using data from the second institution. RESULTS: By multivariate analysis, gender, T, N, and ND stages were independently and significantly associated with survival (p < 0.05). The resulting new staging classification was based on the T and ND. The four new stages led to good separation of survival curves in both the developmental and validation datasets (p < 0.05). CONCLUSIONS: Our results showed that lymph node size is a strong independent prognostic factor and that the new staging system, which incorporated lymph node size, provided good prognostic power, and discriminated effectively for patients with esophageal cancer undergoing CRT.

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

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.

A prospective randomized controlled trial of preoperative whole-liver chemolipiodolization for hepatocellular carcinoma.

BACKGROUND: We previously reported that preoperative chemolipiodolization of the whole liver is effective for reducing the incidence of postoperative recurrence and prolonging survival in patients with resectable hepatocellular carcinoma (HCC). The present randomized controlled trial was performed to evaluate the influence of preoperative transcatheter arterial chemoembolization (TACE) on survival after the resection of HCC. METHODS: Operative results and long-term outcome were prospectively compared among 42 patients who received only selective TACE targeting the tumor (selective group), 39 patients who received TACE targeting the tumor plus chemolipiodolization of the whole liver (whole-liver group), and 43 patients without preoperative TACE or chemolipiodolization (control group). RESULTS: There were no serious side effects of TACE or chemolipiodolization and the operative outcomes did not differ among the three groups. Even though preoperative TACE induced complete tumor necrosis, there were no significant differences in the pattern of intrahepatic recurrence or the time until recurrence among the three groups. There were also no significant differences in disease-free survival or overall survival among the three groups, even among patients with larger tumor size. CONCLUSION: These results indicate that preoperative selective TACE and whole-liver chemolipiodolization plus TACE do not reduce the incidence of postoperative recurrence or prolong survival in patients with resectable HCC.

Metallic stent placement for malignant airway stenosis.

The purpose of this study was to evaluate the utility of metallic stents for treating central airway stenosis caused by malignant tumors. The subjects were 72 patients (16 women, 56 men; mean age, 61 years; age range, 28-87 years) treated with metallic stents for dyspnea due to tracheobronchial stenotic lesions caused by malignant tumors between May 1990 and August 2010. The underlying disorder was primary lung cancer in 42 patients, metastatic lung cancer in 29, and mediastinal tumor in one patient. In 69 of 72 patients (95.8%), dyspnea began to improve following completion of the procedure. The average Hugh-Jones classification score improved from 4.2 before stenting to 2.8 after stenting. The patients' average survival following stent placement was 3.6 months (two days-33 months). Thirteen lesions developed re-obstruction during follow-up. Of these 13 lesions, eight patients with dyspnea underwent re-interventions with metallic stent replacement and improved. Airway stent placement is an immediate and effective method of treatment for dyspnea caused by stenotic lesions of the central airway due to malignant tumor. It is effective for treating stenosis due to either tracheobronchial intraluminal tumor or extrinsic compression. Restenting is also useful to treat dyspnea caused by restenosis following stent placement.

Percutaneous bypass creation between hollow organs by modified gun-sight approach.

This animal study investigated the feasibility of creating a bypass between two hollow organs, using a modified gun-sight approach with a pull-through string and pull-through tow wire. Ten procedures (femoral arteriovenous shunt, n = 4; portacaval shunt, n = 4; cholangiogastrostomy, n = 2) were performed in six adult swine. Snares were inserted into the two hollow organs through the sheath and deployed at the site of bypass creation. When snares overlapped on fluoroscopy, a needle was inserted to pass through both snares. The string was inserted through the needle, with only the needle then withdrawn. The snare furthest from the skin was closed to capture the string and was then withdrawn. The other snare was withdrawn without closing. The string thus served as a pull-through string penetrating both hollow organs. This string was then attached to a pull-through tow wire, withdrawn, and exchanged for the pull-through tow wire. By withdrawing the pull-through tow wire, the delivery sheath connected to the pull-through tow wire was towed through the site of the bypass, and the stent was placed. In all cases, bypass creation was achieved. Percutaneous bypass creation using a modified gun-sight approach with a pull-through string and pull-through tow wire is feasible between two hollow organs.

Added value of percutaneous vertebroplasty: effects on respiratory function.

OBJECTIVE: The objective of our study was to investigate the effects of percutaneous vertebroplasty on respiratory function in patients with compression fractures caused by osteoporosis. SUBJECTS AND METHODS: Ninety-eight patients (87 women, 11 men; mean age, 74 years; age range, 60-90 years) with compression fractures of 75 thoracic (Th7-Th12) and 89 lumbar (L1-L5) vertebrae were enrolled in this study. Percentage vital capacity (VC%), percentage forced vital capacity (FVC%), and percentage forced expiratory volume in 1 second (%FEV1) were measured using a spirometer before, 1 day after, and 1 month after percutaneous vertebroplasty. The Wilcoxon signed rank test was used to evaluate whether any significant differences in VC%, FVC%, or %FEV1 values existed between before, 1 day after, and 1 month after percutaneous vertebroplasty. RESULTS: The VC% and FVC% values had improved significantly by 1 month after percutaneous vertebroplasty compared with before percutaneous vertebroplasty (p<0.01). No significant difference was noted between values before and 1 day after percutaneous vertebroplasty. Likewise, no significant difference was identified in %FEV1 before percutaneous vertebroplasty and either 1 day or 1 month after percutaneous vertebroplasty. The mean degree of improvement in VC% values after percutaneous vertebroplasty for patients with one vertebra treated, which we refer to as the "single-vertebroplasty" group, and for patients with two or more vertebrae treated, or "multiple-vertebroplasty" group, was 1.1%±7% (SD) and 6.3%±8%, respectively, representing a significant difference between groups (p=0.01). The mean VC% values before and 1 month after percutaneous vertebroplasty differed significantly (p=0.02) in the thoracic group and overlapping group. CONCLUSION: Percutaneous vertebroplasty improves restrictive ventilatory impairment, but this improvement requires approximately 1 month to occur. Greater improvement in restrictive ventilatory dysfunction was observed in patients who underwent multiple vertebroplasty procedures than those who underwent a single procedure and in patients who underwent treatment of thoracic vertebrae than those who underwent treatment of other vertebrae.

Differences in Trocar Positioning within the Vertebral Body Using Two Different Positioning Methods: Effect on Trainee Performance.

Purpose. To evaluate the educational effect of the Japanese Society of Interventional Radiology 7th Academic Summer Seminar from a technical perspective. Materials and Methods. Nineteen trainees participated in the seminar. The seminar consisted of vertebroplasty trainings using swine with the single-plane landmark method and with the ISOcenter Puncture (ISOP) method. All trainees were advised by an instructor as they operated the instruments and punctured the vertebra. For each trainee, the accuracy in the final position of the needle tip of the initial puncture in each swine training was evaluated. Results. Error in the final position of the needle tip of ≥5 mm from the target puncture site occurred in the lateral direction in 42% (8/19) of trainees with the landmark method and 5% (1/19) with the ISOP method. No error ≥5 mm occurred in the vertical or anteroposterior directions. In terms of puncture accuracy, error in the lateral direction was significantly lower with the ISOP method than with the landmark method (2.2 ± 1.5 mm versus 5.6 ± 3.2 mm). Conclusion. This seminar was effective training for trocar placement for beginners. The puncture was more accurate with the ISOP method than with the landmark method.

Usefulness of Tc-99m-GSA scintigraphy for liver surgery.

Postoperative mortality remains high after hepatectomy compared with other types of surgery in patients who have cirrhosis or chronic hepatitis. Although there are several useful perioperative indicators of liver dysfunction, no standard markers are available to predict postoperative liver failure in patients with hepatocellular carcinoma (HCC) undergoing hepatectomy. The best preoperative method for evaluating the hepatic functional reserve of patients with HCC remains unclear, but technetium-99m diethylenetriamine pentaacetic acid galactosyl human serum albumin ((99m)Tc-GSA) scintigraphy is a candidate. (99m)Tc-GSA is a liver scintigraphy agent that binds to the asialoglycoprotein receptor, and can be used to assess the functional hepatocyte mass and thus determine the hepatic functional reserve in various physiological and pathological states. The maximum removal rate of (99m) Tc-GSA (GSA-Rmax) calculated by using a radiopharmacokinetic model is correlated with the severity of liver disease. There is also a significant difference of GSA-Rmax between patients with chronic hepatitis and persons with normal liver function. Regeneration of the remnant liver and recurrence of hepatitis C virus infection in the donor organ after living donor liver transplantation have also been investigated by (99m)Tc-GSA scintigraphy. This review discusses the usefulness of (99m)Tc-GSA scintigraphy for liver surgery.

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.