Selective venous sampling supports localization of adenoma in primary hyperparathyroidism.

BACKGROUND: Selective venous sampling (SVS) is an invasive localization study for persistent or recurrent hyperparathyroidism. PURPOSE: To assess the role of SVS in addition to non-invasive imaging for primary hyperparathyroidism (pHPT). MATERIAL AND METHODS: This study was approved by the institutional review board and included 14 patients who underwent SVS and subsequent parathyroidectomy between January 2014 and April 2017 following a clinical diagnosis of pHPT. All patients underwent pre-SVS non-invasive imaging, including ultrasound, computed tomography (CT), and 99mTc-MIBI scintigraphy, and sensitivity was assessed using the operative and pathological findings. RESULTS: In all but one case, a single parathyroid adenoma was responsible for the pHPT; the remaining case exhibited a chemical response following surgical removal of parathyroid tissue. The sensitivity (%) for ultrasound, CT, 99mTc-MIBI scintigraphy, and SVS was 76.9, 84.6, 69.2, and 76.9, respectively. SVS yielded positive results in four patients with discordant results and one patient with non-detectable results on imaging. In seven patients, a significant increase in the intact parathyroid hormone level was recognized only in the thyroid veins. The procedure time was in the range of 52-183 min (median = 89.5 min). CONCLUSION: The addition of SVS to a non-invasive imaging study would be helpful to locate the responsible lesion of pHPT with discordant or non-detectable results on imaging for initial surgical treatment as well.

Selective venous sampling for primary hyperparathyroidism: how to perform an examination and interpret the results with reference to thyroid vein anatomy.

Primary hyperparathyroidism (pHPT) causes hypercalcemia. The treatment for pHPT is surgical dissection of the hyperfunctioning parathyroid gland. Lower rates of hypocalcemia and recurrent laryngeal nerve injury imply that minimally invasive parathyroidectomy (MIP) is safer than bilateral neck resection. Current trends in MIP use can be inferred only by reference to preoperative localization studies. Noninvasive imaging studies (typically preoperative localization studies) show good detection rates of hyperfunctioning glands; however, there have also been cases of nonlocalization or discordant results. Selective venous sampling (SVS) is an invasive localization method for detecting elevated intact parathyroid hormone in the thyroid and/or internal jugular and brachiocephalic veins. SVS was developed mainly for postoperative patients with persistent or recurrent pHPT; however, SVS could also be useful before initial operations due to its high sensitivity to pHPT. Currently, SVS is generally indicated for recurrent HPT, and for cases with negative imaging study results for HPT or discordant results. Multi-detector row helical CT is useful for imaging the anatomy of the jugular and thyroid veins. Knowledge of the thyroid vein anatomy enables the creation of sampling points in the internal jugular and brachiocephalic veins for catheterization of the thyroid veins and venous anastomoses.

Ultraselective transcatheter arterial chemoembolization for small hepatocellular carcinoma guided by automated tumor-feeders detection software: technical success and short-term tumor response.

PURPOSE: To analyze the technical success and tumor response of ultraselective transcatheter arterial chemoembolization (TACE) for small hepatocellular carcinoma (HCC) using automated tumor-feeders detection (AFD) software. METHODS: Prototype AFD software was prospectively applied to cone-beam computed tomography images acquired during TACE for 155 consecutive HCCs ≤50 mm in 81 patients. The detectability of tumor-feeding subsubsegmental arteries was analyzed. Technical success of TACE was classified into three grades according to 1-week CT; the tumor was embolized with a safety margin (5 mm wide for tumors <25 mm, and 10 mm wide for tumors ≥25 mm) (grade A), without a margin in parts (grade B), or the entire tumor was not embolized (grade C). Tumor response at 2-3 months after TACE was also evaluated in 71 patients using the modified Response Evaluation Criteria in Solid Tumors. RESULTS: One-hundred and twenty-eight (82.6%) tumors were classed as grade A, 17 (11%) as grade B, and 10 (6.5%) as grade C. AFD software could identify 211 (85.4%) of 247 tumor-feeders but not 36 (14.6%). Eighteen (7.9%) were false positive. The tumor response of target lesions in each patient was complete response (CR) in 49 (69%) patients, partial response (PR) in 19 (26.8%), and stable disease (SD) in 3 (4.2%). The overall tumor response was CR in 39 (54.9%) patients, PR in 15 (21.2%), SD in 1 (1.4%), and progressive disease in 16 (22.5%). CONCLUSIONS: AFD software has sufficient performance to identify tumor-feeders and contributes to the high technical success in ultraselective TACE.

Percutaneous transluminal angioplasty of a non-mainstream venous route to restore an occluded hemodialysis fistula.

PURPOSE: To report the usefulness of percutaneous transluminal angioplasty (PTA) of a non-mainstream venous route in an occluded native hemodialysis fistula when a mainstream outflow vein could not be traversed. MATERIALS AND METHODS: This cohort included seven patients with an occulted hemodialysis fistula with difficulty in traversing via a mainstream route. A non-mainstream vein near the occluded portion was traversed until it connected with a proximal large-sized vein and the route was dilated using a 4- or 5-mm balloon catheter. Metallic stent placement was performed, if necessary. Technical aspects and long-term patency was evaluated. RESULTS: PTA could be performed in all patients; however, stent placement was required in two because of residual stenosis and clotting. The clinical success rate of fistula restoration was 100 %. Fistula dysfunction recurred in six patients 17-668 days (mean ± standard deviation 229.3 ± 225.0) later. PTA was repeated in four patients, but not in two. The mean duration of the primary patency was 336.6 ± 417.2 days (range 17-1,190) and that of the secondary patency was 897.1 ± 801.4 days (range 17-2,230). CONCLUSION: PTA of a non-mainstream venous route is useful for restoring an occluded hemodialysis fistula when the mainstream outflow vein cannot be traversed.

Comparison of local control in transcatheter arterial chemoembolization of hepatocellular carcinoma ≤6 cm with or without intraprocedural monitoring of the embolized area using cone-beam computed tomography.

PURPOSE: This study was designed to compare technical success and local recurrence rates of transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) with/without monitoring of embolized areas using cone-beam computed tomography (CBCT). METHODS: A total of 207 HCCs ≤6 cm were treated with superselective TACE using digital subtraction angiography (DSA) alone (DSA group, 98 tumors of 70 patients) or plus CBCT monitoring (CBCT group, 109 tumors of 79 patients). Technical success of TACE was classified into three grades according to 1-week CT; the tumor was embolized with a safety margin (5-mm wide for tumors <25 mm, and 10-mm wide for tumors 25≥ and ≤60 mm; grade A), without a margin in parts (grade B), or the entire tumor was not embolized (grade C). Technical success and local recurrence rates in the DSA and CBCT groups were compared. Local recurrence rates of grade A and B tumors were also compared. RESULTS: The grade A/B/C tumors in the DSA and CBCT groups were 64 (65.3%)/25 (25.5%)/9 (9.2%) and 95 (87.2%)/11 (10.1%)/3 (2.8%), respectively. Local recurrence developed in 46/158 (29.1%) grade A tumors and 24/36 (66.7%) grade B. There were significant differences in technical success between the DSA and CBCT groups (p < 0.001) and local recurrence rates between grade A and B tumors (p < 0.001). The 1-, 2-, and 3-year local recurrence rates in the DSA and CBCT groups were 33.3 and 22.3%, 41.3 and 26.8%, and 48 and 30.6%, respectively (p = 0.0217). CONCLUSION: Intraprocedural CBCT monitoring of embolized areas reduces the local tumor recurrence.

Identification of small hepatocellular carcinoma and tumor-feeding branches with cone-beam CT guidance technology during transcatheter arterial chemoembolization.

PURPOSE: To evaluate the performance of transcatheter arterial chemoembolization guidance software that uses cone-beam computed tomography (CT) technology in identifying small hepatocellular carcinoma (HCC) tumors and feeding branches. MATERIALS AND METHODS: Cone-beam CT and manual feeder vessel detection (MFD) software were used in chemoembolization of 68 HCCs 30 mm or smaller (mean ± standard deviation, 15.3 mm ± 5.2). Detectability of tumors and tumor-feeding sub-subsegmental arteries was compared versus that of nonselective digital subtraction angiography (DSA). Technical success of chemoembolization was divided into three grades according to 1-week CT findings: entire tumor embolized with at least a 5-mm-wide margin (ie, complete), tumor embolized without a margin in parts (ie, adequate), or entire tumor not embolized (ie, incomplete). All cone-beam CT data were also reanalyzed with automatic feeder vessel detection (AFD) software that was developed later. RESULTS: Cone-beam CT could depict all tumors, including eight that were first discovered during chemoembolization. Sixty-one tumors (89.7%) were detected on CT during arterial portography and during hepatic arteriography, and seven (10.3%) were detected with one or the other. Nonselective DSA depicted 49 tumors (72.1%). Among 100 tumor-feeding vessels, 81 were identified with MFD and 38 with nonselective DSA. Detectability of tumors with CT and tumor-feeding branches with MFD was significantly better than with nonselective DSA (both P<.001). Fifty-nine tumors (86.8%) were completely embolized and nine (13.2%) were adequately embolized. AFD identified 96 feeder vessels; 88 (88%) represented true-positive findings. CONCLUSIONS: Transcatheter arterial chemoembolization guidance software with cone-beam CT technology has a sufficient performance level to detect small HCCs and their feeding branches.

Blood supply of the main bile duct from the caudate artery and medial subsegmental artery of the hepatic artery: Evaluation using images obtained during transcatheter arterial chemoembolization for hepatocellular carcinoma.

AIM: Main bile duct necrosis develops after transcatheter arterial chemoembolization (TACE) through the caudate artery (A1) and medial subsegmental artery (A4) of the hepatic artery in the treatment of hepatocellular carcinoma. The aim of this study was to evaluate the bile duct branch (BD branch) from A1 and A4. METHODS: We evaluated the origin and vascular territory of the BD branch in 11 patients who underwent selective A1 and/or A4 arteriography using arteriograms, cone-beam computed tomography (CBCT) and CT obtained 1 week after TACE. Follow-up CT and/or magnetic resonance imaging were also evaluated. RESULTS: The BD branch arose from the first branch (n = 4), the second branch (n = 1), and both the first and second branches (n = 1) of A1, and from the first branch of A4 (n = 5). It supplied the bilateral hepatic ducts and common hepatic duct (CHD) (n = 4), the right hepatic duct (RHD) and CHD (n = 2), RHD, CHD and common bile duct (n = 1), the left hepatic duct (LHD) and CHD (n = 2), and LHD alone (n = 2). Anastomosis between A1 or A4 and other branches was demonstrated in seven patients. Bile duct stricture developed in all nine patients 2-8 months after TACE of the BD branch and percutaneous transhepatic bile duct drainage and metallic stent placement was required in one because of jaundice. CONCLUSION: The BD branch arises from the proximal portion of A1 and A4 and mainly supplies the hepatic ducts and CHD.

Clinical features of hepatocellular carcinoma supplied by the left internal mammary artery.

PURPOSE: To evaluate the clinical features of hepatocellular carcinoma (HCC) supplied by the left internal mammary artery (LIMA). MATERIALS AND METHODS: This cohort included 12 HCCs of 12 patients supplied by the LIMA. The clinical features of these tumors were analyzed. RESULTS: The tumor diameters were 4.2 ± 4.4 cm (mean ± SD) located at the surface of segments 4 (n = 6), 3 (n = 3), 2 (n = 2), and 4-8 (n = 1), respectively. The tumor was supplied by the phrenic branch (n = 8) or musclophrenic artery (n = 4) entirely (n = 7) or partially (n = 5). Two patients with large tumors 10 and 16 cm in diameter, respectively, received no previous treatment. Ten patients had previously undergone 5.8 ± 3.7 TACE sessions including through extrahepatic collaterals. Selective TACE could not be completed in one. No TACE-related complications developed. Of 11 embolized tumors, six did not recur at 8.8 ± 4.6 months and five recurred 4.4 ± 2.6 months later. CONCLUSION: The clinical features of HCC supplied by the LIMA can be divided into two categories, untreated large tumors and small tumors receiving multiple TACE sessions at the subcapsular area of the left hepatic lobe.

Low-temperature dynamic light scattering. I. Structural reorganization and physical gel formation in cellulose triacetate/methyl acetate dilute solution at -99 - 45 degrees C.

Curious low-temperature solubility of cellulose triacetates (CTA; here we use nominally "CTA," but the sample still contains 7% of C-6 position hydroxyls) in an organic solvent, methyl acetate (MA), was studied by a newly designed low-temperature type of DLS apparatus, which enabled for the first time to investigate the structural change of CTA in solution from 45 degrees C down to -100 degrees C. A molecularly dissolved CTA was found to coexist with three types of self-assemblies over all the temperature ranges except for the three specific temperatures T* of 30, -10, and -75 degrees C. However, these multiple self-assemblies are not in real thermodynamic equilibrium but in a metastable state, which could be stabilized effectively by the intermolecular hydrogen bonding (HB) with the help of the dipole interaction at low temperatures. In more detail, with decreasing temperature, these assemblies performed the structural reorganization drastically at three T*'s and would finally be frozen in a physical gel structure at -99 degrees C; around the freezing temperature of MA, CTA molecules could be trapped homogeneously in the frozen MA. The crucial role in such structural reorganizations is played by the balance between the intermolecular HB and the dipole interaction worked in the highly electronegative solvent. Because these interactions, which are mediated by the solvent electronegativity, change drastically with temperature, they result in the control of not only the single CTA chain conformation (= the intramolecular HB) but also the binding ways of the intermolecular HBs between CTA molecules and they induce multitudinous metastable structures in solution. Here it is noted that HB could work mainly between the C-6 position hydroxyls in the anhydroglucose units of CTA and are essentially effective at low temperatures.

Magnetic alignment of the chiral nematic phase of a cellulose microfibril suspension.

Stable suspensions of tunicate cellulose microfibrils were prepared by acid hydrolysis of the cellulosic mantles of tunicin. They formed a chiral nematic phase above a critical concentration. External magnetic fields were applied to the chiral nematic phase in two different manners to control its phase structure. (i) Static magnetic fields ranging 1-28 T were used to align the chiral nematic axis (helical axis) in the field direction. (ii) A rotating magnetic field (5 T, 10 rpm) was applied to unwind the helices and to form a nematic phase. These phenomena were interpreted in terms of the anisotropic diamagnetic susceptibility of the cellulose microfibril. The diamagnetic susceptibility of the microfibril is smaller in the direction parallel (chi( parallel)) to the fiber axis than in the direction perpendicular (chi( perpendicular)) to the fiber axis, that is, chi( parallel) < chi( perpendicular) < 0. Because the helical axis coincides with the direction normal ( perpendicular) to the fiber axis, the helical axis aligned parallel to the applied field. On the other hand, the rotating magnetic field induced the uniaxial alignment of the smallest susceptibility axis, that is, chi( parallel) in the present case, and brought about unwinding of the helices.