Nondermatomal somatosensory deficits in chronic pain patients: are they really hysterical?

Patients with chronic pain disorders frequently show nondermatomal somatosensory deficits (NDSDs) that are considered to be functional. Typically, NDSDs show quadratomal or hemibody distribution ipsilateral to the areas of chronic pain. According to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition and the International Classification of Diseases, 10th revision, such functional somatosensory deficits are classified in the chapter "conversion disorder." Many publications also used the term "hysterical sensory loss." However, doubts are increasing about this one-sided psychiatric view. We aimed to better characterize the biopsychosocial factors associated with NDSDs. Therefore, we compared 2 groups of inpatients with chronic pain disorder, of whom 90 suffered from NDSDs and 90 did not. The patients with NDSDs all showed widespread somatosensory deficits with hemibody distribution. On logistic regression analysis, history of a prior physical trauma was positively predictive for patients with NDSDs. Personality disorder and adverse childhood experiences were positively predictive for the control group with chronic pain disorders without NDSDs. The frequencies of comorbid depression and anxiety disorder did not differ statistically between groups. In conclusion, pain patients with NDSDs are, psychopathologically, by no means more noticeable personalities than patients with chronic pain disorder without NDSDs. Similar to complex regional pain syndromes, we assume a multifactorial etiology of NDSDs, including stress. Based on our observations, terms like "hysteric" should not be applied any longer to patients with NDSDs who suffer from chronic pain.

Polyurethane-covered dacron mesh versus polytetrafluoroethylene DualMesh for intraperitoneal hernia repair in rats.

PURPOSE: Abdominal hernia repair using the intraperitoneal implantation of a prosthesis requires mesh with impervious properties, such as expanded polytetrafluoroethylene (ePTFE). A newly developed polyurethane-covered polyester mesh with impervious properties has recently been introduced as a less expensive alternative to PTFE, and we compare these materials herein. METHODS: The adhesion formation and stability of intraperitoneal abdominal hernia repairs with DualMesh (macroporous ePTFE mesh with a microporous component) and PolyesterComposite (the newly developed polyurethane-covered Dacron mesh) were compared in a rat model. Forty rats were randomly divided into two groups; ten animals from each group were killed after 14 days, and the other ten after 90 days. RESULTS: The number and intensity of adhesions were comparable in the PolyesterComposite and PTFE groups. Loose adhesions were seen in 13 animals and appeared only selectively at the fixation sutures. Both PolyesterComposite and PTFE induced the formation of a smooth neoperitoneum on the intraperitoneal surface and showed a complete ingrowing of the prosthesis in the surrounding tissue. There were no significant differences between the prostheses in terms of clinical herniation pressure and hydroxyproline concentration. CONCLUSIONS: PolyesterComposite and PTFE are both suitable prostheses for intrapertoneal implantation, but PolyesterComposite is less expensive, which is an important advantage for clinical use.

Trevira mesh: a promising new implant for the treatment of abdominal hernias.

BACKGROUND: Trevira (polyethylene terephthalate) has been in clinical use for more than 20 years, serving as implant material with minimal foreign body reaction for the replacement of the cruciate ligaments of the knee. An animal (pig) trial was performed to ascertain whether a Trevira mesh offers any advantages over currently employed meshes like Prolene for abdominal hernia repair. METHODS: In 12 mini-pigs 10 x 10 cm of the musculofascial abdominal layer was resected preserving the peritoneum. Subsequently, a 15 x 15 cm synthetic mesh was implanted (Prolene, Ethicon, Norderstedt, Germany, or Trevira, Telos GmbH, Marburg, Germany, in six animals each) using sublay technique. The main focus was on the extent of the chronic foreign body reaction. This was assessed by a pathologist who paid special attention to the presence of foreign body giant cells after 2 and 6 months. A further assessment was made of shrinkage of the implant as a result of foreign body reaction. RESULTS: The number of giant cells after two months was significantly higher with the Prolene implant than with the Trevira implant (Prolene 2.2+/-0.4, Trevira 0.8+/-0.2, per fixed microscopic field; P<0.05). After 6 months the number of giant cells associated with the Prolene implants rose further, while it remained relatively constant for those of Trevira (Prolene 4.6+/-1.3, Trevira 1.1+/-0.5; P<0.05). No significant difference was noted over time between the two types of implant with regard to shrinkage (2 months: Prolene 0.8+/-0.3 cm(2), Trevira 0.6+/-0.4 cm(2); 6 months: Prolene 1.3+/-0.6 cm(2), Trevira 1.1+/-0.5 cm(2)). CONCLUSION: In this animal study Trevira mesh demonstrated a high biocompatibility with a low foreign body reaction; it appears to be a promising new implant for the treatment of hernias.