Ruptured tectal arteriovenous malformation demonstrated angiographically after removal of an unruptured occipital lobe arteriovenous malformation

We report a case of ruptured tectal arteriovenous malformation (AVM) that was demonstrated angiographically only after removal of an unruptured occipital AVM. A 57-year-old man presented with sudden onset of diplopia and tinnitus. Computed tomography revealed a small hemorrhage in the right tectum mesencephali with intraventricular hemorrhage. Magnetic resonance imaging and angiography disclosed AVM in the right occipital lobe which was separate from the hemorrhagic lesion. Angiography demonstrated that the right occipital AVM was fed by the parieto-occipital artery and drained into the superior sagittal sinus and vein of Galen. However, no abnormal vascular lesion was detected near the tectum mesencephali. As venous hypertension was considered the reason for hemorrhage, the occipital AVM was completely resected. Postoperative angiography demonstrated disappearance of the occipital AVM, but it also disclosed a small tectal AVM fed by branches from the superior cerebellar artery, which had not been detected on preoperative angiography. This was considered the true cause of hemorrhage, and gamma knife surgery was accordingly performed. Even if an AVM is demonstrated, if the lesion does not correspond to the hemorrhage we recommend serial angiographical evaluation so that a small AVM is not missed.

[Outcomes of bronchoplasty procedures for lung cancer]

A sleeve lobectomy is an established general thoracic surgical procedure. To improve clinical outcomes following the procedure, we reviewed the records of 60 patients who underwent a bronchoplasty procedure in our department from 1992 to 2007. Induction chemotherapy was performed for 20, of whom 10 underwent radiotherapy as well. For all subjects, the postoperative mortality and morbidity rates were 1.7% and 33.3%, respectively. Induction therapy did not significantly affect those rates, though complications related to bronchial anastomoses occurred exclusively in subjects who received that therapy. The overall 5-year survival rate was 51.0%, while subjects with pN0 (67.9%) and pN1 (60.0%) disease, and those in stage I (79.1%) and stage II (59.9%) had better survival as compared with patients with pN2 (16.9%) disease, and those in stage III (21.8%) and stage IV (0%). Furthermore, the survival rate of yp-stage I and II patients was significantly greater than that of those in yp-stage III and IV (59.9% vs. 14.3%, p = 0.0158). We concluded that patients in stages I, II or with pN0-1 disease are good candidates for a bronchoplasty procedure, though induction therapy should be considered thereafter. In addition, due diligence for postoperative complications is necessary.

[Full-thickness pleural biopsy using an Insulation-tipped Diathermic Knife in a patient with malignant pleural mesothelioma]

A 72-year-old woman was pointed out a right pleural effusion and thickening pleura on the chest computed tomography. The patient underwent semiflexible thoracoscopy under local anesthesia at the endoscopy room. The patient was placed in the lateral decubitus position, and flexible trocar was inserted with the single puncture technique. At the macroscopic findings, the parietal pleura were thickened prominently, and patchy plaques were occasionally recognized. A standard biopsy forceps hardly grasped pleura because of presence of scar, so we performed pleural biopsy using Insulation-tipped Diathermic (IT) knife. A subpleural injection of saline containing 0.5% lidokine and 0.005% epinephrine was performed for raising the affected parietal pleura with an injection needle. After a pin hole was made, the pleural lesion was incised in a circle by manipulating the IT knife, and the incised pleura were removed. Pathology revealed extensive fibrosis and epithelial mesothelioma by the specimen. This biopsy technique using IT knife through semiflexible thoracoscopy enabled to obtain a full-thickness pleura It is thought to be useful for the diagnosis of malignant pleural mesothelioma (MPM) in which standard forceps are difficult to grasp.

Reproducibility of haemodynamical simulations in a subject-specific stented aneurysm model--a report on the Virtual Intracranial Stenting Challenge 2007

This paper presents the results of the Virtual Intracranial Stenting Challenge (VISC) 2007, an international initiative whose aim was to establish the reproducibility of state-of-the-art haemodynamical simulation techniques in subject-specific stented models of intracranial aneurysms (IAs). IAs are pathological dilatations of the cerebral artery walls, which are associated with high mortality and morbidity rates due to subarachnoid haemorrhage following rupture. The deployment of a stent as flow diverter has recently been indicated as a promising treatment option, which has the potential to protect the aneurysm by reducing the action of haemodynamical forces and facilitating aneurysm thrombosis. The direct assessment of changes in aneurysm haemodynamics after stent deployment is hampered by limitations in existing imaging techniques and currently requires resorting to numerical simulations. Numerical simulations also have the potential to assist in the personalized selection of an optimal stent design prior to intervention. However, from the current literature it is difficult to assess the level of technological advancement and the reproducibility of haemodynamical predictions in stented patient-specific models. The VISC 2007 initiative engaged in the development of a multicentre-controlled benchmark to analyse differences induced by diverse grid generation and computational fluid dynamics (CFD) technologies. The challenge also represented an opportunity to provide a survey of available technologies currently adopted by international teams from both academic and industrial institutions for constructing computational models of stented aneurysms. The results demonstrate the ability of current strategies in consistently quantifying the performance of three commercial intracranial stents, and contribute to reinforce the confidence in haemodynamical simulation, thus taking a step forward towards the introduction of simulation tools to support diagnostics and interventional planning.

Impact of stent design on intra-aneurysmal flow. A computer simulation study

SUMMARY

In addition to providing a skeleton for vessel reconstruction, stent implantation as used for cerebral aneurysm treatment can induce flow redirection, thus reducing vortical flow velocities within the aneurysm cavity. Further, stent characteristics such as strut size, porosity and cell shape influence the changes in intra-aneurysmal flow by analog simulations. The purpose of this computer simulation study was to visualize the flow pattern over the entire neck area of a side wall aneurysm while changing the stent parameters. A 3-D computer model aneurysm was constructed to have a parent artery of 5 mm diameter and an aneurysm of 10 mm diameter. The distance between the midline of main artery and center point of the aneurysm was 6.8 mm, providing a neck length of 5 mm, a width of 3.6 mm, and a neck area of 14 mm 2. The simulations were carried out with a Finite Element Method based flow simulation package. The incompressible Navier-Stokes equation was solved for a steady flow with a mean speed of 290 mm/s, steady viscosity of 3.83 cp, and density of 1.0 g/cm3. Two parallel stent struts (dimensions: 100 mum m 100 mum m 2.0 mm) were introduced into the plane of the aneurysm neck. The fraction of the aneurysm neck cross-section occupied by the stent was 2.83% in all cases. The velocity distribution through the neck of the aneurysm was calculated for three different choices of separation between the struts for each of two orientations of the struts (parallel and perpendicular) relative to the vessel axis. The flow pattern in the aneurysm was composed of an inflow zone at the distal neck and of an outflow zone at the proximal neck. The placement of stent struts at the aneurysm neck resulted in a decrease in the mean speed in the aneurysm. The degree of reduction and the distribution of flow through the neck did depend on the orientation of the stent struts. The struts, when placed parallel or perpendicular to the parent vessel axis affected the mean speed through the aneurysm neck differently.

Studies on Design Optimization of Coronary Stents

The stent design itself seems to be one of the factors responsible for restenosis. As a remedy, the present work attempts to perform a design optimization of coronary stents from a hemodynamic point of view. For the purpose, we have applied the principles of modern exploration of design space restricting ourselves to two-dimensional considerations. Width, thickness, and spacing of the struts of the stent formed the design variables. The objectives chosen for optimization were the vorticity generated, length of recirculation zone, and the reattachment distance in between the struts. Both semicircular and rectangular cross sections of stents were included. Starting with the range of design variables, sample stent cases were generated using Latin hypercube sampling. Objective functions were calculated for each of these by computing the two-dimensional flow using software FLUENT under the assumption of a steady, Newtonian flow considering a model stent with three struts. This was followed by Kriging to construct a response surface, which gives the relationship between the objectives and the design variables. The procedure gave nondominated fronts, which consist of optimized designs. Stents with minimum vorticity, with minimum recirculation distance, and the ones with maximum reattachment length in between struts were generated. The procedure is capable of producing the optimum set of design variables to achieve the prescribed objectives.

Prognosis of patients with intrahepatic recurrence after hepatic resection for hepatocellular carcinoma: a retrospective study

AIMS

Hepatic resection is the most effective therapy for hepatocellular carcinoma (HCC); however, intrahepatic recurrence is common. Predictors of survival after intrahepatic recurrence have not been fully investigated. To clarify the prognosis and choice of treatment of intrahepatic recurrence after hepatic resection, we conducted a comparative retrospective analysis of 147 patients with HCC who underwent hepatic resection.

METHODS

We retrospectively examined the relations between clinicopathologic factors, including the number of recurrent intrahepatic tumors and long-term prognosis after recurrence in 147 HCC patients who underwent resection. We also examined long-term survival after recurrence based on treatment types and recurrence pattern.

RESULTS

Patients with multiple tumors (n=83) showed less tumor differentiation, more frequent portal invasion, a higher alpha-fetoprotein level, and larger tumors than did patients with solitary tumor (n=64). In the solitary tumor group, local ablation therapy and repeat hepatic resection were performed in 25 and 10, respectively. In the multiple tumor group, 59 were treated by transarterial chemoembolization. Multivariate analysis showed intraoperative blood transfusion and multiple tumors to be independent risk factors for poor cancer-related survival after recurrence. By subset analysis based on treatment types and recurrence pattern, survival after recurrence was significantly better in patients treated by local ablation therapy than those treated by other therapies in both solitary and multiple tumor groups.

CONCLUSIONS

For patients with solitary recurrence, a good prognosis is predicted. Local ablation therapy is a best candidate for treatment of solitary and multiple intrahepatic recurrences after hepatic resection.

Peripheral nerve regeneration through the space formed by a chitosan gel sponge

The clinical treatment of traumatized peripheral nerves often requires grafting of autologous cutaneous nerves. However, there are drawbacks in sacrificing healthy nerves and tissue scarring. In this study, an artificial material, freeze-dried chitosan gel sponge, was examined as a scaffold for nerve regeneration in rats. An 8-mm gap was made by removing a segment of the sciatic nerve, and the distal and proximal stumps were sandwiched by chitosan gel sponge. Rats were killed at 4, 7, 14, and 28 days, and 2 and 4 months after the operation and histological and morphometric evaluations were performed. Regenerating axons were observed at 4 days after the operation. Regenerating nerves extended the distal stump at 14 days after surgery. By electron microscopy, numerous macrophages appeared to phagocyte chitosan, and made a dense cell layer on the chitosan. Regenerating axons did not touch the chitosan, and extended through the space surrounded by macrophage-stacked chitosan. Regenerating nerves were well-myelinated 2 months after surgery. Regenerating nerves were on average 2.45 and 2.75 microm in diameter at 2 and 4 months, respectively, after surgery. These results indicate that the chitosan gel sponge sandwich might be suitable as a graft for peripheral nerve regeneration.

Clinical and experimental features of MuSK antibody positive MG in Japan

We investigated the presence of antibodies (Abs) against muscle-specific tyrosine kinase (MuSK) in Japanese myasthenia gravis (MG) patients. MuSK Abs were found in 23 (27%) of 85 generalized seronegative MG (SNMG) patients but not in any of the ocular MG patients. MuSK Ab-positive patients were characterized as having female dominance (M:F, 5:18), age range at onset 18 to 72 (median 45) years old, and prominent oculobulbar symptoms (100%) with neck (57%) or respiratory (35%) muscle weakness. Limb muscle weakness was comparatively less severe (52%), thymoma absent. Most patients had good responses to simple plasma exchange and steroid therapy. MuSK IgG from all 18 patients was exclusively the IgG 4 subclass and bound mainly with the MuSK Ig 1-2 domain. Serial studies of 12 individuals showed a close correlation between the variation in MuSK Ab titers and MG clinical severity (P = 0.01 by Kruskal-Wallis). MuSK Ab titers were sharply decreased in patients who had a good response to early steroid therapy or simple plasma exchange, but there was no change, or a rapid increase on exacerbation after thymectomy. Measurement of MuSK Ab titers aids in the diagnosis of MG and the monitoring of clinical courses after treatment.

Metabolic syndrome is not associated with markers of subclinical atherosclerosis, serum adiponectin and endogenous androgen concentrations in Japanese men with Type 2 diabetes

AIMS

Metabolic syndrome is characterized by its association with certain cardiovascular disease risk factors. The aim of this study was to investigate the relationships between metabolic syndrome and markers of subclinical atherosclerosis, serum adiponectin and endogenous androgen concentrations in Japanese men with Type 2 diabetes.

METHODS

Using the 2005 International Diabetes Federation (IDF) definition, we assessed the prevalence of the metabolic syndrome in 424 consecutive men with Type 2 diabetes aged 40-75 years in a cross-sectional study. We compared characteristics including ultrasonographic carotid atherosclerosis markers, pulse-wave velocity (PWV), and serum adiponectin, free testosterone, and dehydroepiandrosterone sulphate (DHEA-S) concentrations in diabetic patients with and without the metabolic syndrome.

RESULTS

The prevalence of the metabolic syndrome in Japanese men with Type 2 diabetes was 46.9%. Men with the metabolic syndrome had higher urinary albumin excretion rate than those without. Carotid intima-media thickness (0.97 +/- 0.26 vs. 0.91 +/- 0.18 mm), plaque score [3.3 (1.5-8.1) vs. 3.8 (1.3-6.2)], PWV (1818 +/- 331 vs. 1749 +/- 331 cm/s) and ankle-brachial index (1.10 +/- 0.14 vs. 1.08 +/- 0.16) did not differ significantly between patients with and without the metabolic syndrome. Similarly, serum adiponectin [3.70 (2.06-6.09) vs. 4.65 (3.09-7.02) microg/ml], free testosterone (36.4 +/- 10.7 vs. 34.7 +/- 11.1 pmol/l), and DHEA-S concentrations (3.29 +/- 1.83 vs. 3.17 +/- 1.63 micromol/l) did not differ significantly between groups,

CONCLUSIONS

The metabolic syndrome, as defined by the IDF, is not significantly associated with subclinical atherosclerosis markers, serum adiponectin, or endogenous androgen concentrations in Japanese men with Type 2 diabetes.

Recent advances in the surgical treatment for esophageal cancer in Japan: An experience of 1000 cases who underwent an esophagectomy at a single institute

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Background: Most cases of esophageal cancer are squamous cell carcinoma in Japan and the prognosis of such patients tends to be poor. However, the clinical results after an esophagectomy have recently been reported to improve. Methods: The mortality and morbidity as well as the patients’ prognosis were evaluated in 1000 cases of esophageal cancer who all underwent an esophagectomy in the Department of Surgery and Science (Department of Surgery II), Kyushu University, Japan from 1964 to 2006. The incidence of squamous cell carcinoma was 94 %. The patients were divided into three groups according to the operation period: Group I (n=197), Group II (n=432), and Group III (n=371) underwent an esophagectomy during the periods of ‘64-’80, ’81-’93, and ’93-’06, respectively. The incidences of TNM Stage 0 or I gradually increased (4, 19 and 24 %, respectively), while those of Stage IV decreased (28, 19 and 14 %). Results: The 5-yr overall survival rates (OSR) and cause-specific survival rate (CSR) after an esophagectomy for all 1000 cases were 30 and 37 %, respectively. The 5-yr OSRs of Groups I, II and III were 14, 27 and 46 %, while the 5-yr CSRs were 18, 36, and 52 %, respectively (P<0.01 between each group). When the prognoses were compared for each TNM stage, an improvement in the prognosis was observed at every tumor stage. A multivariate analysis (Cox proportional hazard model) revealed not only the age, depth of invasion, node metastasis, curability (each P<0.001) and extent of a lymphadenectomy (P<0.05) but also the operation period (P<0.001) to be independent prognostic factors. The morbidity rates of Groups I, II and III were 62, 38, and 33 %, and the incidences of pulmonary complications were 42, 13 and 14 %, respectively (P<0.01, Group I vs. II and I vs. III). The 30-day mortality rates were 8.1, 2.1 and 0 %, respectively (P<0.01 between each group). Conclusions: An analysis of a total of 1000 cases with esophageal cancer revealed that an esophagectomy has generally been safely performed without any critical pulmonary complications, while an increasingly favorable prognosis has been achieved due to recent advances in surgical techniques and treatment modalities.

No significant financial relationships to disclose.

Why did the gender difference influence survival in patients with completely resected stage I adenocarcinoma of the lung?

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Background: This study evaluates the influence of gender on survival and tumor recurrence in patients with completely resected stage IA and IB adenocarcinoma of the lung based on the analysis of the Japan Lung Cancer Research Group trial, which was a randomized prospective study of adjuvant chemotherapy with uracil-tegaful for stage I pulmonary adenocarcinoma. Methods: Patients were randomized to receive either oral uracil-tegaful (250 mg of tegaful/m2/day) for 2 years postoperatively or no adjuvant treatment. Survival was calculated from randomization until death. Survival estimated using the Kaplan-Meier method, and difference in survival between two groups was compares with the log-rank test. Results: The 5-year survival rate was 88.9% for the 502 women and 84.3% for the 477 men (median follow-up 72 months, p=0.0066). The relative risk of death for men vs women was 0.658 (95% C.I., 0.476–0.910, p=0.011), although the mean age of men was significantly less than that of women (p=0.041). There was no interaction between the gender differences and the efficacy of uracil-tegaful (p=0.657). However men presented with significantly more preoperative complications, more T2 diseases (p=0.0006), less non-papillary growth for histology (p=0.0078), less well differentiated subtype (p<0.001), higher serum carcinoembryonic antigen (CEA) level (p=0.004), and more smoking history than women (p<0.0001). Disease recurrence patterns were similar between the genders. The postoperative mortality showed a tendency to go up in men. Conclusions: Although longer life expectancy for women in Japan may in part explain, gender influences survival after complete resection for stage IA-B lung adenocarcinoma. The reasons for prolonged survival of women with this disease may be related to the several differences in the distribution of preoperative complications, smoking history and tumor biological behaviors such as T descriptor, histologic subtype, and serum CEA level. However cause- specific mortality was difficult to be explained. Further molecular epidemiologic and molecular profiling studies regarding gender as a prognostic and predictive factor for survival should be done.

No significant financial relationships to disclose.