摘要:

The breast implant crisis has been widely publicized. Beyond its immediate problems for the patients, the crisis has also discredited the use of silicone rubber as one of the most widely used biomaterials. Silicone elastomer or gel, the primary material in mammary prostheses, may be exposed to the body's tissues via envelope rupture, gel bleed, or elastomer fragmentation. Local responses to silicone include granulomatous inflammation, capsular contraction, and infection, all in varying degrees depending on ill-defined factors, which may include patient condition, peri- and postoperative complications, and hereditary predisposition, as well as material properties such as surface texture. The theory that silicone breast implants cause immunological disorders has not been proven. However, further study is necessary because some patients report autoimmune-like disorders (human adjuvant disease) following implant placement. Like autoimmune disease, human adjuvant disease is characterized by abnormalities of the immune response, autoantibody formation, and chronic inflammation. Silicone has been shown to play the role of an adjuvant, providing constant nonspecific stimulation of the immune system. Some researchers have hypothesized the role of silicone in specific immune reactions, including immunoglobulin formation and T-cell activation. This report examines the role of silicone as an agent of disease, focusing on material surface-tissue interactions.

ISSN:0894-1939    

DOI:10.3109/08941939609012455

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

The absence of foreign bodies in sutureless anastomoses provides faster healing. The first sutureless cholecystojejunostomies were reported by Murphy in 1892. The common bile duct was tied and 11 cholecystojejunostomies plus 12 jejunojejunostomies were performed in 12 Landrace pigs employing sliding absorbable intraluminal nontoxic stents (SAINTs) and fibrin glue. One cholecystojejunostomy was not performed owing to a gallbladder morphologic anomaly. Three animals died of problems unrelated to the SAlNT-glue anastomoses. Of the 18 anastomoses in the 9 remaining animals, all were patent at the verification times of 14, 30, 120, and 480 days. Morphologically, there was greater edema and reduced height of the glandular epithelium in the 30-day CJs when compared to the jejunojejunal anastomoses. Results indicate that the sutureless SAINT–fibrin glue procedure is quite versatile and may be utilized for cholecystoenteric anastomoses.

ISSN:0894-1939    

DOI:10.3109/08941939609012456

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

This manuscript presents experimental data in the area of biomechanical cardiac support obtained at the Bakulev Institute for Cardiovascular Surgery in Moscow, Russia. After creation of the left ventricular aneurysm and subsequent cardiomyoplasty, active functioning of the muscle–heart complex was observed. In the late postoperative stages (3–6 months) hemodynamic parameters did not reach original preoperative values, but were satisfactory to support decreasing heart function: Cardiac index was decreased by 9.8%, the pumping coefficient of the left heart (KLH) by 24.7%, and left ventricular stroke work index (LVSWI) fell by 25%. Acute aneurysm of the left ventricle is a good model to study the effectiveness of cardiomyoplasty. Determination of parameters for stimulation of the muscle autograft showed that from the point of view of hemodynamic parameters of the muscle-heart complex, the optimal initial training schedule is a burst of seven pulses, each from 0.07 to 0.6 ms in duration, with a frequency of 30–50 Hz, an amplitude of 6 V, and a burst following frequency of 15–30 per minute.

ISSN:0894-1939    

DOI:10.3109/08941939609012457

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

The effect of esophageal distension on the lower esophageal sphincter (LES) in 14 normal volunteers and 6 esophageal achalasia (EA) patients was studied. A balloon-tipped catheter was introduced into the LES and a second one into the esophagus. The pressure response of LES to balloon distension of the esophagus and pharyngoesophageal sphincter (PES) was recorded. In normal subjects, esophageal distension caused significant decrease of LES pressure; this reflex action was reproducible and was called“esophagosphincter inhibitory reflex”(ESIR). PES distension caused insignificant LES pressure changes (p>. 05). Distension of the anesthetized esophagus or PES did not evoke LES pressure response. The ESIR was nonfatigable. In EA patients, the resting LES pressure was significantly higher than normal (p<. 01). Upon esophageal distension, the LES pressure increased, while no response occurred with PES distension. There was paradox ESIR in EA with a resulting esophagosphincter dyssynergia. To conclude, the ESIR seems to be of significance in esophageal motility disorders and may be incorporated as investigative tool in such conditions.

ISSN:0894-1939    

DOI:10.3109/08941939609012458

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Glutaraldehyde-preserved bovine pericardium (GPBP) is evaluated as a bioprosthesis for the reconstruction of surgical defects in the thoracoabdominal wall. The mechanical properties of bovine pericardium preserved at different concentrations of glutaraldehyde were studied. Samples preserved in 0.5% glutaraldehyde showed a significantly higher tensile strength (11.7±0.8 N/mm2) than samples preserved in 2.5, 5, or 10% (similar to pericardium preserved in normal saline). The percentage of elongation was significantly lower than samples preserved in 1, 2.5, and 5% glutaraldehyde. GPBP at 0.5% was used to repair experimentally induced defects of the abdominal wall (n = 9), chest wall (n = 6), diaphragm (n = 6), and sternum (n = 7). All animals presented adequate tolerance to the material used and no case of infection or rejection of the material was seen in any of the animals. Finally, 0.5% GPBP was used clinically in a series of 40 patients: postincisional abdominal hernia (n = 30), inguinal hernia (n = 8), diaphragmatic hernia (n = I), and congenital pelvic defect with prolapse of abdominal organs (n = 1). Surgical use showed that GPBP was a very manageable material and long-term results were good in 37patients with a mean follow up of 18 months (range 5-35 months). Six patients presented seroma formation (all abdominal hernia patients), three of which eventually developed infection and had the GPBP patch removed at 3, 5, and 7 months postoperatively. The rest of the patients presented good scar formation with adequate resistance at the area of implantation. GPBP is a biological material with sufficient resistance to be used surgically in the repair of thoracoabdominal defects. Ideal concentration of glutaraldehyde to be used in the preparation–preservation of the material is 0.5% since higher concentrations negatively affect its tensile rupture strength and elongation.

ISSN:0894-1939    

DOI:10.3109/08941939609012459

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

ISSN:0894-1939    

DOI:10.3109/08941939609012460

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor