The Diagnostic Value of Endoscopic Ultrasonography and Magnetic Resonance Imaging for Anorectal Malignant Melanoma: Report of a Case

A 74-year-old Japanese woman presented with a 3-month history of anal bleeding. Proctoscopy revealed an unusual polypoid lesion with focal pigmentation at the dentate line, which was histologically diagnosed as a malignant melanoma. Whole-body clinical and radiographic evaluations revealed no alternative primary source. Endoscopic ultrasonography (EUS) showed well-delineated hypoechoic tumors invading the muscularis propria, and magnetic resonance imaging (MRI) revealed regional lymphadenopathy. Following this evaluation, an abdominoperineal resection with regional lymphadenectomy was performed. The excised tumor was histologically confirmed to be malignant melanoma, and its depth and metastatic lymph nodes proved to have been accurately and precisely evaluated by the preoperative examinations. Thus, EUS and MRI are useful preoperative diagnostic tools for the tumor staging of primary anorectal malignant melanomas, as for other rectal tumors. Received: February 1, 2002 / Accepted: September 3, 2002 Reprint requests to: H. Sashiyama     

Influence of type II endoleak volume on aneurysm wall pressure and distribution in an experimental model

OBJECTIVE(S): We have previously shown that type II endoleak size is a predictor of aneurysm growth after aortic endografting. To better understand this observation, we investigated the influence of endoleak size on pressure transmitted to the aneurysm wall and its distribution within the aneurysm sac. METHODS: In an ex vivo model, an artificial aneurysm sac was incorporated within a mock circulation comprised of rubber tubing and a pulsatile pump. Three strain-gauge pressure transducers were placed in the aneurysm wall at different locations, including the site of maximum aneurysm diameter. The aneurysm was filled with either human aneurysm thrombus or dough that mimicked thrombus and simulated type II endoleaks of varying volumes (1 to 10 mL) were created. Aneurysm wall pressure (AWP) measurements were recorded at mean arterial pressures (MAPs) of 60, 80, and 100 mm Hg. Correlation coefficients ( r ) and analysis of variance were used to assess the relationship between endoleak volume and AWP. RESULTS: Increasing endoleak volume '3 cm 3 resulted in proportionally increased AWP at all levels of MAP and at all sites, with highest pressures recorded at the site of the maximum aneurysm diameter (r = 0.83 when MAP = 100 mm Hg; r = 0.85 when MAP = 80 mm Hg; r = 0.88 when MAP = 60 mm Hg; P < .001). AWP plateaued when the endoleak volume was >3 cm 3 . Pressure distribution within the sac was not uniform. Although the difference was within +/-10%, statistically significant higher AWPs were observed at the site of maximum aneurysm diameter (P <.001). AWP also correlated with MAP. CONCLUSIONS: Increasing type II endoleak volume results in proportionally higher AWP, which is greatest at the site of maximum aneurysm diameter. This study confirms the clinical observation that type II endoleak volume and MAP may be important predictors of aneurysm expansion. CLINICAL RELEVANCE: Our experimental model of a type II endoleak revealed that endoleak size is a significant factor that influences the magnitude of pressure transmission into the aneurysm wall. Increasing volume of the endoleak nidus was associated with proportionally higher aneurysm sac pressures. This mechanism may, in fact, account for the increased risk of aneurysm expansion observed in our clinical experience, thereby suggesting the need for more aggressive surveillance and possibly earlier intervention for patients with larger endoleaks.     

Social Predictors of Continued and Indoor Smoking Among Partners of Non-smoking Pregnant Women: The TMM BirThree Cohort Study

BackgroundSecondhand smoke (SHS) from partners is a major source of exposure for non-smoking women. However, epidemiological studies have rarely examined social factors associated with continued and indoor smoking among pregnant women’s partners.MethodsWe analyzed data on 6,091 partners of non-smoking pregnant women in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Partners’ age, education, income, workplace SHS exposure (almost never or sometimes, almost every day), and pregnant women’s smoking history (never, quit before pregnancy awareness, quit after pregnancy awareness) were used as social factors. Multiple logistic regression analyses were conducted to examine the associations of social factors with partners’ continued smoking and indoor smoking.ResultsAmong 2,432 smoking partners, 2,237 continued to smoke after pregnancy awareness. Workplace SHS exposure was associated with increased risk of partners’ continued smoking: the odds ratio of workplace SHS exposure almost every day compared with almost never or sometimes was 2.08 (95% confidence interval, 1.52–2.83). Women’s quitting smoking after—but not before—pregnancy awareness was associated with decreased risk of partners’ continued smoking: the odds ratio of women’s quitting after pregnancy awareness compared with never smoking was 0.57 (95% confidence interval, 0.40–0.80). About one-third of partners who continued to smoke did so indoors. Older age, lower education, workplace SHS exposure, and women’s quitting smoking after pregnancy awareness were associated with increased risk of partners’ indoor smoking.ConclusionsWorkplace SHS exposure and pregnant women’s smoking history were associated with continued smoking and indoor smoking among partners of non-smoking pregnant women.Key words: continued smoking, indoor smoking, Japan, partners, pregnant women     

Nature and significance of endoleaks and endotension: summary of opinions expressed at an international conference

OBJECTIVE: Endoleaks and endotension are critically important complications of some endovascular aortic aneurysm repairs (EVARs). For the resolution of controversial issues and the determination of areas of uncertainty relating to these complications, a conference of 27 interested leaders was held on November 20, 2000. METHODS: These 27 participants (21 vascular surgeons, five interventional radiologists, one cardiologist) had previously answered 40 key questions on endoleaks and endotension. At the conference, these 40 questions and participant answers were discussed and in some cases modified to determine points of agreement (consensus), near consensus (prevailing opinion), or disagreement. RESULTS: Conference discussion added two modified questions for a total of 42 key questions for the participants. Interestingly, consensus was reached on the answers to 24 of 42 or 57% of the questions, and near consensus was reached on 14 of 42 or 33% of the questions. Only with the answers to four of 42 or 10% of the questions was there persistent controversy or disagreement. CONCLUSION: The current endoleak classification system with some important modifications is adequate. Types I and II endoleak occur after 0 to 10% and 10% to 25% of EVARs, respectively. Many (30% to 100%) type II endoleaks will seal and have no detrimental effect, which never or rarely occurs with type I endoleaks. Not all endoleaks can be visualized with any technique, and increased pressure (endotension) can be transmitted through clot. Aneurysm pulsatility after EVAR correlates poorly with endoleaks and endotension. An enlarging aneurysm after EVAR mandates surgical or interventional treatment. These and other conclusions will help to resolve controversy and aid in the management of these vexing complications and should also point the way to future research in this field.     

Non-protein-bound transition metals and hydroxyl radical generation in cerebrospinal fluid of newborn infants with hypoxic ischemic encephalopathy

Among various hypothetical mechanisms for the in vivo production of reactive oxygen species, transition metal-catalyzed reactions in cooperation with a biologic reducing agent like ascorbic acid or superoxide may be some of the most important. In the present study, we retrospectively examined the existence of non-protein-bound metal ions, an essentially hazardous pro-oxidant form of various transition metals, and the occurrence of metal-catalyzed reactive oxygen species production in cerebrospinal fluid (CSF) of 10 infants with hypoxic ischemic encephalopathy (HIE) subsequent to perinatal asphyxia and 12 control infants within 72 h of birth. Non-protein-bound iron was detected in eight out of 10 CSF samples from the HIE infants and its level was significantly correlated with Sarnat's clinical stage, whereas none of the control infants had detectable non-protein-bound iron levels. Non-protein-bound copper was below the detection limit in all CSF samples from both groups. Ascorbic acid was significantly increased in the CSF of HIE infants when compared with that of controls (means, 664.9 versus 449.4 microM, p = 0.008). ortho-Tyrosine and meta-tyrosine, which are highly specific and sensitive markers of protein oxidation induced by hydroxyl radicals, were significantly higher in HIE infants than in controls when evaluated by the ratio relative to their source amino acid, phenylalanine [means, 110.5 versus 75.4, p = 0.018 for ortho-tyrosine/phenylalanine; 104.6 versus 67.7 (nM/microM x 10(2)), p = 0.048 for meta-tyrosine/phenylalanine]. Both ratios were significantly correlated with non-protein-bound iron, but not with ascorbic acid. Our preliminary observations provide direct evidence that hydroxyl radicals are generated in the CNS during asphyxiation. Iron chelation therapy could be worth developing as a neuroprotective strategy for perinatal asphyxia.     

Irregular Defects in Hepatocellular Carcinomas During the Kupffer Phase of Contrast-Enhanced Ultrasonography with Perfluorobutane Microbubbles: Pathological Features and Metastatic Recurrence After Surgical Resection

The present study aimed to elucidate the association between post-vascular–phase (Kupffer-phase) images from contrast-enhanced ultrasonography (CEUS) with perfluorobutane microbubbles and metastatic recurrences after the resection of hepatocellular carcinoma (HCC). The study examined 73 patients with solitary HCC ≤5 cm in diameter who underwent CEUS before resection. HCC was defined as irregular type (including an irregular defect on Kupffer-phase images) or non-irregular type. Intrahepatic metastatic recurrence was defined as >3 intrahepatic recurrences. Metastatic recurrence included both extrahepatic and intrahepatic recurrences. Frequencies of microscopic portal invasion and intrahepatic metastasis were significantly higher in the irregular group than in the non-irregular group. Cumulative 5-y metastatic recurrence rates in the irregular and non-irregular groups were 43% and 7% (p = 0.028), respectively. Multivariate analyses identified Kupffer-phase findings as a factor significantly related to metastatic recurrence. In conclusion, HCCs with an irregular defect during Kupffer-phase CEUS are characterized by more frequent microscopic vascular invasion and intrahepatic metastasis and are significantly associated with metastatic recurrence after resection.     

A case of apogeotropic nystagmus with brainstem lesion: An implication for mechanism of central apogeotropic nystagmus

We report a case showing apogeotropic nystagmus with the lesion of the brain stem, and discuss a possible mechanism of central apogeotropic nystagmus. The case was a 73-year-old male. We analyzed his nystagmus three-dimensionally. He showed apogeotropic nystagmus. Axis angles of slow phase eye velocity of his apogeotropic nystagmus were not in line with the axes perpendicular to the plane of horizontal semicircular canals, but with the patient's vertical axis. We then found that his nystagmus including the apogeotropic nystagmus was positioning, but not positional and that the direction of his positioning nystagmus was the same direction of postrotatory nystagmus after his head movement. His MRI scans showed an infarction around the prepositus hypoglossi nucleus of the brain. His apogeotropic nystagmus seemed to consist of a combination of prolonged postrotatory nystagmus after his head rotation to the left and right lateral position because the axis of postrotatory nystamus was in line with the axis of the head rotation. Therefore, it is suggested that a possible mechanism of central apogeotropic nystagmus is a prolonged postrotatory nystagmus after his head movement in the supine position due to the brain lesion involving the velocity storage mechanisms.     

Cost-effectiveness of treatment of unruptured intracranial aneurysms in patients with a history of subarachnoid hemorrhage

RATIONALE AND OBJECTIVES: The study goal was to evaluate the cost-effectiveness of surgery and endovascular treatment of unruptured intracranial aneurysms in patients with a history of subarachnoid hemorrhage from a previous aneurysm, incorporating the results of the prospective International Study of Unruptured Intracranial Aneurysms. MATERIALS AND METHODS: Using a Markov model, we performed a decision and cost-effectiveness analysis comparing surgery or endovascular treatment with no treatment. Twelve clinical scenarios were defined based on aneurysm size and location. Probabilistic sensitivity analyses were performed for 50- and 40-year-old cohorts. Treatment was considered to be cost-effective at an incremental cost-effectiveness ratio less than $100,000 per quality-adjusted life-year. RESULTS: In 50-year-old patients, no treatment was the most cost-effective strategy for aneurysms located in the cavernous carotid artery. For aneurysms less than 7 mm located in the anterior circulation, no treatment was the most cost-effective strategy. Endovascular treatment was the most cost-effective option for 7- to 24-mm aneurysms, whereas surgery was the most cost-effective option for aneurysms of 25 mm or larger. For aneurysms less than 7 mm and located in the posterior circulation, endovascular treatment was the most cost-effective option, whereas surgery was the most cost-effective option for 7- to 12-mm aneurysms. No treatment was the most cost-effective strategy for aneurysms of 13 mm or larger. CONCLUSION: For 50-year-old patients with a history of aneurysmal subarachnoid hemorrhage, treatment of unruptured aneurysms that are located in the cavernous carotid artery, or small (<7 mm) and located in the anterior circulation, or large (>or=13 mm) and located in the posterior circulation is ineffective or not cost-effective.     

Mechanical accuracy of a stereotactic irradiation system using a micro multi-leaf collimator

Mechanical accuracy of a stereotactic irradiation system using a micro multi-leaf collimator (mMLC), Elekta DMLC, has been evaluated. Measurements were made to obtain transmission, leakage, penumbra, and positioning accuracy of the DMLC leaf for a 6 MV photon beam. Mechanical accuracy and long term stability of a linac isocenter was also evaluated. The resulting transmission, along a line perpendicular to the leaf movement, was 0.31±0.01%, and the leakage from the closed opposing leaf pairs was 0.39±0.01%. The measured penumbra, at a depth incurring maximum dose, was 2.37±0.16 mm toward the leaf end and 2.14±0.18 mm toward the leaf side for various field sizes. The leaf gap width error, of 0.10±0.08 mm, was obtained by analyzing picket fence test results. The maximum leaf positioning error, of 0.14±0.06 mm, was obtained by analyzing the log file for a various gantry angles during an arc delivery. The isocenter accuracy was within a radius of 1 mm, without any recalibration for two years. In conclusion, our stereotactic irradiation system using DMLC was capable of providing accurate stereotactic treatment.