Balloon dilation of intrahepatic biliary strictures for percutaneous extraction of residual intrahepatic stones

Intrahepatic ductal strictures in cholangiohepatitis present an obstacle to successful removal of retained ductal stones via T-tube tracts. We studied the effectiveness of stricture dilatation for stone removal. Fifteen patients with intrahepatic gallstones retained behind strictures underwent balloon dilatation of their strictures to allow stone extraction. All had prior surgical T-tube placement allowing percutaneous access. Balloon dilatation was successful in reducing or eliminating strictures in 86.7% (13 of 15 patients), and complete stone extraction after the successful dilatation was possible in 76.9% (10 of 13 patients). The reasons for failure were impacted stones and acute ductal angulation which prevented passage of catheters. It is concluded that balloon dilatation of intrahepatic biliary strictures is an effective adjunct for extraction of intrahepatic biliary calculi associated with recurrent pyogenic cholangiohepatitis.     

MR Imaging in Patients with Suspected Liver Metastases: Value of Liver-Specific Contrast Agent Gadoxetic Acid

Objective

To compare the diagnostic performance of gadoxetic acid-enhanced magnetic resonance (MR) imaging with that of triple-phase multidetector-row computed tomography (MDCT) in the detection of liver metastasis.

Materials and Methods

Our institutional review board approved this retrospective study and waived informed consent. The study population consisted of 51 patients with hepatic metastases and 62 patients with benign hepatic lesions, who underwent triple-phase MDCT and gadoxetic acid-enhanced MRI within one month. Two radiologists independently and randomly reviewed MDCT and MRI images regarding the presence and probability of liver metastasis. In order to determine additional value of hepatobiliary-phase (HBP), the dynamic-MRI set alone and combined dynamic-and-HBP set were evaluated, respectively. The standard of reference was a combination of pathology diagnosis and follow-up imaging. For each reader, diagnostic accuracy was compared using the jackknife alternative free-response receiver-operating-characteristic (JAFROC).

Results

For both readers, average JAFROC figure-of-merit (FOM) was significantly higher on the MR image sets than on the MDCT images: average FOM was 0.582 on the MDCT, 0.788 on the dynamic-MRI set and 0.847 on the combined HBP set, respectively (p < 0.0001). The differences were more prominent for small (≤ 1 cm) lesions: average FOM values were 0.433 on MDCT, 0.711 on the dynamic-MRI set and 0.828 on the combined HBP set, respectively (p < 0.0001). Sensitivity increased significantly with the addition of HBP in gadoxetic acid-enhanced MR imaging (p < 0.0001).

Conclusion

Gadoxetic acid-enhanced MRI shows a better performance than triple-phase MDCT for the detection of hepatic metastasis, especially for small (≤ 1 cm) lesions.     

Hemodynamic changes during posterior vessel off-pump coronary artery bypass: comparison between deep pericardial sutures and vacuum-assisted apical suction device

Background

Displacement of the heart to expose posterior vessels during off-pump coronary artery bypass may cause hemodynamic derangement. The aims of this study were (1) to elucidate the hemodynamic changes during off-pump coronary artery bypass for the obtuse marginal branch (OM) of the left circumflex artery; and (2) to compare the hemodynamic changes caused by a deep pericardial suture technique with those caused by a vacuum-assisted apical suction device for displacement of the heart.

Methods

Hemodynamic changes during posterior vessel off-pump coronary artery bypass were studied in a prospective randomized manner. A deep pericardial suture technique (group 1, n = 10) or a vacuum-assisted apical suction device (group 2, n = 10) was used to facilitate the exposure of the OM. Hemodynamic variables such as cardiac index, stroke volume index (SVI), mean arterial pressure, mean pulmonary artery pressure, central venous pressure, pulmonary capillary wedge pressure, heart rate, systemic vascular resistance, pulmonary vascular resistance, left ventricular stroke work index, and right ventricular stroke work index were monitored during off-pump coronary artery bypass. Hemodynamic data were obtained before revascularization of the left anterior descending coronary artery at a baseline (T0), 3 minutes after heart displacement for revascularization of OM (T1), 3 minutes after the beginning of OM grafting (T2), and 3 minutes after the completion of OM grafting and heart repositioning (T3).

Results

There were no significant differences in the baseline hemodynamic variables (T0) between the two groups. In group 1, SVI, cardiac index, left ventricular stroke work index, and right ventricular stroke work index decreased significantly, and central venous pressure and pulmonary capillary wedge pressure increased significantly, during displacement of the heart (T1, p < 0.05). In group 2, SVI decreased significantly, and central venous pressure, pulmonary capillary wedge pressure, and mean pulmonary artery pressure increased significantly during displacement of the heart (T1, p < 0.05). The percent changes of cardiac index, SVI, and right ventricular stroke work index during OM grafting (T2) in comparison with baseline values (T0) were significantly larger in group 1 than in group 2 (cardiac index, 73% ± 12% versus 90% ± 11%; SVI, 69% ± 12% versus 86% ± 8%; right ventricular stroke work index, 30% ± 17% versus 71% ± 25%, in groups 1 versus 2, respectively; p < 0.05).

Conclusions

Displacement of the heart using either a deep pericardial suture technique or a vacuum-assisted apical suction device caused a significant decrease in SVI. The hemodynamic changes during OM grafting were smaller when using a vacuum-assisted apical suction device.     

Comparing the short-term outcomes of totally intracorporeal gastroduodenostomy with extracorporeal gastroduodenostomy after laparoscopic distal gastrectomy for gastric cancer: a single surgeon’s experience and a rapid systematic review with meta-analysis

Background

Since delta-shaped gastroduodenostomy was introduced, many surgeons have utilized laparoscopic distal gastrectomy (LDG) with totally intracorporeal Billroth I (ICBI) for gastric cancer, because it is expected to have several advantages over laparoscopic-assisted distal gastrectomy with extracorporeal Billroth I (ECBI). In this study, we compared these two reconstruction options to evaluate their outcomes.

Methods

The data of 166 gastric cancer patients who underwent LDG performed by a single surgeon between April 2009 and February 2012 were analyzed retrospectively. The subjects were divided into ECBI (n = 106) and ICBI (n = 60) groups, and then the clinical characteristics, surgical outcomes, symptoms, and change in BMI at 3 months after surgery were compared. Furthermore, a rapid systematic review and meta-analysis were conducted.

Results

The operative time was significantly shorter in the ICBI group (197.4 ± 45.5 vs. 157.1 ± 43.9 min), but blood loss was similar between the groups. Regarding surgical outcomes, there were no significant differences in the length of hospital stay, soft diet initiation, visual analogue scale, frequency of analgesics injection, and postoperative white blood cell counts and C-reactive protein levels between the groups. The surgical complication rates were 5.7 and 13.3 % in the ECBI and ICBI groups, respectively, and one case of anastomosis leakage was observed in each group. At 3 months after surgery, reflux symptoms were more frequent in the ICBI group, but other gastrointestinal symptoms and the change of BMI were similar between the groups. The meta-analysis revealed no significant differences in the operative time, time to first flatus, length of hospital stay, frequency of analgesic usages, and rates of anastomosis complications between the groups.

Conclusions

We could not demonstrate the clinical superiority of ICBI over ECBI based on our data and a rapid systematic review and meta-analysis. The anastomosis method may be selected according to patient conditions and the surgeon’s preference.     

New subtraction algorithms for evaluation of lesions on dynamic contrast-enhanced MR mammography

We report new subtraction algorithms for the detection of lesions in dynamic contrast-enhanced MR mammography(CE MRM). Twenty-five patients with suspicious breast lesions underwent dynamic CE MRM using 3D fast low-angle shot. After the acquisition of the T1-weighted scout images, dynamic images were acquired six times after the bolus injection of contrast media. Serial subtractions, step-by-step subtractions, and reverse subtractions, were performed. Two radiologists attempted to differentiate benign from malignant lesion in consensus. The sensitivity, specificity, and accuracy of the method leading to the differentiation of malignant tumor from benign lesions were 85.7, 100, and 96%, respectively. Subtraction images allowed for better visualization of the enhancement as well as its temporal pattern than visual inspection of dynamic images alone. Our findings suggest that the new subtraction algorithm is adequate for screening malignant breast lesions and can potentially replace the time–intensity profile analysis on user-selected regions of interest. Electronic Publication     

Intracranial and Spinal Ependymomas: Review of MR Images in 61 Patients

Objective

To compare the age distribution and characteristic MR imaging findings of ependymoma for each typical location within the neuraxis.

Materials and Methods

During a recent eleven-year period, MR images of 61 patients with histologically proven ependymomas were obtained and retrospectively reviewed in terms of incidence, peak age, location, size, signal intensity, the presence or absence of cyst and hemorrhage, enhancement pattern, and other associated findings.

Results

Among the 61 patients, tumor location was spinal in 35 (57%), infrartentorial in 19 (31%), and supratentorial in seven (12%). In four of these seven, the tumor was located in brain parenchyma, and in most cases developed between the third and fifth decade. Approximately half of the infratentorial tumors occurred during the first decade. The signal intensity of ependymomas was non-specific, regardless of their location. A cystic component was seen in 71% (5/7) of supratentorial, 74% (14/19) of infratentorial, and 14% (5/35) of spinal cord tumors. Forty-nine percent (17/35) of those in the spinal cord were associated with rostral and/or caudal reactive cysts. Intratumoral hemorrhage occurred in 57% (4/7) of supratentorial, 32% (6/19) of infratentorial, and 9% (3/35) of spinal cord tumors. In 17% (6/35) of spinal ependymomas, a curvilinear low T2 signal, suggesting marginal hemorrhage, was seen at the upper and/or lower margins of the tumors. Peritumoral edema occurred in 57% (4/7) of supratentorial, 16% (3/19) of infratentorial and 23% (8/35) of spinal cord tumors. Seventy-two percent (5/7) of supratentorial and 95% (18/19) of infratentorial tumors showed heterogeneous enhancement, while in 50% (17/34) of spinal cord tumors, enhancement was homogeneous.

Conclusion

Even though the MR imaging findings of ependymomas vary and are nonspecific, awareness of these findings, and of tumor distribution according to age, is helpful and increases the likelihood of correct preoperative clinical diagnosis.     

CT and MR imaging features of adnexal torsion.

In adnexal torsion, the ovary, ipsilateral fallopian tube, or both twist with the vascular pedicle, resulting in vascular compromise. Unrelieved torsion is likely to cause hemorrhagic infarction as the degree of arterial occlusion increases. Therefore, early diagnosis is important to preserve the affected ovary. Adnexal torsion commonly accompanies an ipsilateral ovarian neoplasm or cyst but can also occur in normal ovaries, usually in children. Although ultrasonography is typically the initial emergent examination, computed tomography (CT) and magnetic resonance (MR) imaging may also be useful diagnostic tools. Common CT and MR imaging features of adnexal torsion include fallopian tube thickening, smooth wall thickening of the twisted adnexal cystic mass, ascites, and uterine deviation to the twisted side. Uncommon imaging findings in adnexal torsion that are specific to hemorrhagic infarction include hemorrhage in the thickened fallopian tube, hemorrhage within the twisted ovarian mass, and hemoperitoneum. Additional imaging findings that can suggest hemorrhagic infarction include eccentric smooth wall thickening exceeding 10 mm in a cystic ovarian mass converging on the thickened fallopian tube and lack of contrast enhancement of the internal solid component or thickened wall of the twisted ovarian mass. Early diagnosis can help prevent irreversible structural damage and may allow conservative, ovary-sparing treatment.     

Additive Schwarz Preconditioners with Minimal Overlap for Triangular Spectral Elements

The additive Schwarz preconditioner with minimal overlap is extended to triangular spectral elements (TSEM). The method is a generalization of the corresponding method in tensorial quadrilateral spectral elements (QSEM). The proposed preconditioners are based on partitioning the domain into overlapping subdomains, solving local problems on these subdomains and solving an additional coarse problem associated with the subdomain mesh. The results of numerical experiments show that the proposed preconditioner are robust with respect to the number of elements and are more efficient than the preconditioners with generous overlaps.