Characterization of heavyweight and lightweight polypropylene prosthetic mesh explants from a single patient.

Although polypropylene has been used as a hernia repair material for nearly 50 years, very little science has been applied to studying the body's effect on this material. It is possible that oxidation of mesh occurs as a result of the chemical structure of polypropylene and the physiological conditions to which it is subjected; this leads to embrittlement of the material, impaired abdominal movement, and chronic pain. It is also possible that lightweight polypropylene meshes undergo less oxidation due to a reduced inflammatory reaction. The objective of this study was to characterize explanted hernia meshes using techniques such as scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and compliance testing to determine whether the mesh density of polypropylene affects the oxidative degradation of the material. The hypothesis was that heavyweight polypropylene would incite a more intense inflammatory response than lightweight polypropylene and thus undergo greater oxidative degradation. Overall, the results support this theory.

Materials characterization of explanted polypropylene hernia meshes.

Hernia repair with prosthetic mesh significantly decreases the rate of recurrence compared with traditional, primary suture repair by reducing the tension on the edges of the wound. However, there are several complications associated with the use of mesh that may be due to the chronic inflammatory reaction to the mesh or a loss of compliance after degradation of the material. Mesh contraction and migration can also occur, sometimes resulting in a recurrent hernia. Based on the chemical structure of the polypropylene mesh material and the physiological conditions to which it is subjected, it is possible that oxidation is responsible for these changes in material properties. Oxidation would result in surface cracking, decreased melting temperature, loss of mass, and reduced compliance of the material. The objective of this study was to identify physiochemical changes in the surface and bulk properties of explanted polypropylene hernia meshes compared to pristine polypropylene mesh materials. Several characterization techniques were utilized, including scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and compliance testing. Overall, the results supported our hypothesis that oxidation is involved with the degradation of polypropylene hernia mesh materials.

Use of porcine dermal collagen as a prosthetic mesh in a contaminated field for ventral hernia repair: a case report.

Chronic infection of a prosthetic mesh implant is a severe complication of ventral hernia repair, and mesh explantation is usually required in these cases. Biologic mesh implants have a possible role in ventral hernia repair in this setting. Here we present a case of chronic mesh infection following ventral hernia repair and the use of a biologic mesh to repair the existing defect following explantation of the infected mesh. Analysis of the explant material demonstrated possible oxidative degradation of the original polypropylene. A review of the literature follows.

Bilingual telephone-assisted computerized speech-recognition assessment: is a voice-activated computer program a culturally and linguistically appropriate tool for screening depression in English and Spanish?

The purpose of this study was to evaluate an automated voice-interactive program for screening depression in English and Spanish. The Center for Epidemiological Studies-Depression Scale (CES-D) was administered in two interview formats: a speech recognition program presented by cellular telephone, and a face-to-face method. In a single-session counterbalanced design, 32 English speakers and 23 Spanish speakers completed randomly ordered administrations of the two CES-D methods, the Beck Depression Inventory (BDI), and the Short Acculturation Scale (SAS). There was strong evidence that the two CES-D methods were psychometrically equivalent, reliable, and valid in both languages. The two methods were highly rated by both language groups. The Spanish speakers did not display a preference for either method, but the English speakers preferred the face-to-face method. The results also suggested that verbal response latency time was positively correlated with depression scores. Last, the Spanish-speakers' acculturation levels were not correlated with depression scores. Differences in age, education, and income between the language groups were confounded by unequal sample sizes. The findings generally supported the viability of the automated CES-D as a culturally and linguistically appropriate tool for screening depression in English and Spanish. Furthermore, the analyses of respondent voice characteristics show promise as a method for screening depression in both languages.