Chronic emesis due to compression of the area postrema by the posterior inferior cerebellar artery: resolution following microvascular decompression

Chronic emesis may result from a variety of causes. To the authors' knowledge, compression of the area postrema by regional vessels resulting in chronic emesis has not been reported. The authors report on a child who presented with chronic medically intractable emesis and significant weight loss requiring jejunostomy feeding. Surgical exploration of the posterior cranial fossa found unilateral compression of the area postrema by the posterior inferior cerebellar artery. Microvascular decompression resulted in postoperative and long-term resolution of the patient's emesis. Although apparently very rare, irritation of the area postrema from the posterior inferior cerebellar artery with resultant medically intractable chronic emesis may occur. Therefore, the clinician should be aware of this potential etiology when dealing with such patients.     

High prevalence of HIV infection associated with incarceration among community-based injecting drug users in Tehran, Iran

OBJECTIVES: To determine the prevalence and correlates of HIV-1 infection among community-based injecting drug users (IDUs) in Tehran, Iran. METHODS: In October 2004, 213 IDUs were recruited from a drop-in center and its neighboring parks and streets in Tehran. Participants were interviewed using a structured questionnaire regarding their sociodemographics and HIV risk characteristics, and specimens of oral mucosal transudate were collected and tested for HIV-1 antibodies. Data were analyzed using chi and multiple logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: The prevalence of HIV-1 infection was 23.2% (48 of 207) among male injecting drug users. In the multivariable analysis, a history of shared drug injection inside prison (OR, 2.45; 95% CI, 1.01-5.97) and that of multiple incarcerations (OR, 3.13; 95% CI, 1.08-9.09) were associated with significantly higher prevalence of HIV-1 infection. CONCLUSIONS: The prevalence of HIV-1 infection has reached an alarming level among IDUs in Tehran, with incarceration-related exposures revealed to be the main correlates of HIV-1 infection. Urgent and comprehensive harm reduction programs for drug users in prison and those in the community in Tehran are of prime importance to prevent further transmission of HIV infection.     

Pemphigus vulgaris and herpesviruses: is there any relationship?

Background Pemphigus is an autoimmune disorder, which results from interaction of exogenous and endogenous factors. One of these environmental factors is viral infections particularly, herpesviruses. We aimed to detect the presence of HSV 1 and 2 (herpes simplex virus) and HHV8 (human herpesvirus 8) in our patients who were suffering from pemphigus vulgaris. Methods In this cross‐sectional study, 38 patients (19 male and 19 female patients) with pemphigus vulgaris were entered, 32 skins and six peripheral blood cells samples were obtained from the study population. Thereafter, the presence of HHV8 and HSV DNA were evaluated by using polymerase chain reaction (PCR). Results The mean age of patients was 45.05 ± 17.24 years (range: 16–81 years). Twelve patients mentioned history of herpes labial in the past (31.57%). Results of PCR test for detection of HSV and HHV8 DNA in all 32 skin samples and five peripheral blood samples and one case with skin and blood samples were reported negative. Conclusion Inability to detect HHV8 and HSV DNA in this study suggests that herpesviruses may be only occasional factors for development or exacerbation of pemphigus vulgaris.     

Mobile phone radiation interferes laboratory immunoenzymometric assays: Example chorionic gonadotropin assays

The radiofrequency radiation is of concern in hospital laboratories as the microwaves have many health effects even on immune functions. The aim of this study was, however, to evaluate the effects of cell phone radiation on chorionic gonadotropin immunoassays of human serum. Two cell phones with 0.69 and 1.09W/kg (head SAR) emitting 900MHz radiation were used. Sixty wells with five human serum concentrations (0, 10, 100, 250, 500mIU/mL) were used in three batches. The well heads in each batch were exposed to 900MHz emitted from these phones, and the 0.69, 1.09W/kg exposed batches were compared with the unexposed controls. Radiation exposure from mobile phones altered the measured serum levels especially in the wells with 100, 250, 500mIU/mL hormone concentrations. Exposure at 1.09W/kg SAR caused a significant loss compared to 0.69W/kg SAR exposure. In conclusion, the microwave exposures may require attention in laboratories using immunoassays.     

Low-permeability Gore Excluder device versus the original in abdominal aortic aneurysm size regression

We sought to compare the efficacy of a low-permeability version of the Gore Excluder™ device with that of the original device. We used volumetric analysis and maximum transverse diameter measurements to examine abdominal aortic aneurysm size regression after endovascular aneurysm repair.From November 2002 through April 2007, 101 patients (82% men; mean age, 71.5 ± 8.9 yr) underwent endovascular aneurysm repair with the Excluder stent-graft: 34 with the original device, and 67 with the low-permeability device. Only patients without endoleak and with preprocedural and 1- and 2-year follow-up computed tomographic scans were included. Eight patients with type II endoleak and 2 with type I endoleak were excluded. Maximum abdominal aortic aneurysm diameter and volume were measured before endovascular aneurysm repair and annually thereafter. Postprocessing, multiplanar computed tomography, and 3-dimensional reconstructions were compared with baseline measurements. Diameter and volume changes that were greater than 5 mm or that exceeded 10% were considered significant.At 12 months, the mean maximum transverse diameter had decreased by −0.16 ± 12.1 mm in recipients of the original device and by −4.8 ± 5.9 mm in recipients of the low-permeability device (P = NS). In addition, mean reduction in volume had changed by −17 ± 16 mL in original-device recipients and by −36.1 ± 37.9 mL in low-permeability device recipients (P < 0.01).One-year follow-up revealed that the low-permeability stent-graft resulted in a greater decrease in abdominal aortic aneurysm volume than did the original stent-graft.Key words: Aortic aneurysm, abdominal/exclusion/repair; blood vessel prosthesis; endoleak; stent-grafts; stents; tomography, x-ray computed; treatment outcomeEndovascular aortic repair (EVAR) has become an accepted treatment technique for patients with abdominal aortic aneurysm (AAA). Compared with surgery, EVAR is associated with less operative blood loss, shorter hospital and intensive care unit stays, fewer major postoperative complications, and more rapid convalescence.^1–3 In addition, EVAR has proved beneficial in the treatment of high-risk patients who cannot undergo standard surgical AAA repair. Two recent prospective, randomized trials have shown that, compared with surgery, EVAR is associated with a reduction in 30-day perioperative mortality.^4,5 The GORE® EXCLUDER® AAA Endoprosthesis (W.L. Gore & Associates, Inc.; Flagstaff, Ariz) is currently 1 of 5 endografts approved by the U.S. Food and Drug Administration for clinical use in the treatment of infrarenal AAA. The Excluder endograft is a bifurcated endoprosthesis composed of a trunk-ipsilateral endoprosthesis and a contralateral leg endoprosthesis. The graft material consists of expanded polytetrafluoroethylene (ePTFE) and fluorinated ethylene propylene. The material is supported by nitinol (nickel-titanium alloy) wire along its external surface, which is attached to the graft by a bonding film.In the mid-term Excluder Pivotal Trial, the original Excluder device was associated with a higher aneurysm expansion rate than that observed with other commercially available devices.^6,7 Some patients in this trial had aneurysm expansion without an identifiable endoleak, a phenomenon termed endotension. As the trial showed, the causes of aneurysm enlargement are multifactorial and include both endoleaks and endotension due to the material''s high permeability by plasma. As a result, several patients in this trial had to undergo late conversion to open surgical intervention.⁸ In an effort to resolve this issue, in June 2004, W.L. Gore & Associates modified the Excluder graft material to reduce its permeability. The purpose of the present study was to compare the efficacy of the new, low-permeability (LP) Excluder device with that of the original device by using volumetric analysis and measuring maximum transverse diameter to examine regression in AAA size after EVAR.     

A single-center experience with eccentric syringomyelia found with pediatric Chiari I malformation

Introduction

Eccentric syringes associated with Chiari I malformation have received scant attention in the medical literature. Herein, we describe our experience and long-term outcome in patients with this finding.

Materials and methods

A retrospective analysis of a Chiari I database was performed. Patients known to have an associated syringomyelia were then further analyzed for the type of syrinx present. When an eccentric syrinx was noted, the symptoms and postoperative course of these patients were analyzed.

Results

Of well over 500 operative cases of Chiari I malformation, roughly 70?% (pre-syrinx and minimally dilated central canals were excluded) were found to have an associated syringomyelia. Of these, four patients were found to have an eccentrically positioned syrinx. Three of these cases presented with symptoms referable to the side of the eccentric syrinx. Postoperatively, cases with both a central and eccentrically located syrinx were found to have a greater decrease in the size of the central portion of their syrinx compared to the eccentrically located portion. Symptoms decreased in all patients.

Conclusions

The minority of our patients with hindbrain-induced syringomyelia were found to have an eccentrically located syrinx. Of these, most will have symptoms localized to the abnormal fluid-filled cavity, and these may not decrease in size as much as centrally located syringes following posterior fossa decompression. However, all symptoms decreased in those operated. Based on the literature, non-hindbrain-induced syringomyelia is more likely to result in an eccentrically placed syrinx. The mechanism for this is yet to be elucidated.     

The cranial dura mater: a review of its history, embryology, and anatomy

Introduction

The dura mater is important to the clinician as a barrier to the internal environment of the brain, and surgically, its anatomy should be well known to the neurosurgeon and clinician who interpret imaging.

Methods

The medical literature was reviewed in regard to the morphology and embryology of specifically, the intracranial dura mater. A historic review of this meningeal layer is also provided.

Conclusions

Knowledge of the cranial dura mater has a rich history. The embryology is complex, and the surgical anatomy of this layer and its specializations are important to the neurosurgeon.     

Two-stage Exchange Arthroplasty for Infected Total Knee Arthroplasty: Predictors of Failure

Background  

In North America, a two-stage exchange arthroplasty remains the preferred surgical treatment for chronic periprosthetic joint infection (PJI). Currently, there are no proper indicators that can guide orthopaedic surgeons in patient selection for two-stage exchange or the appropriate conditions in which to reimplant.