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PubMed2002

[Interventional occlusion of foramen ovale and atrial septal defects after paradoxical embolism incidents].

Two hundred and fifty-one patients with a persistent foramen ovale (PFO), mean age 43.3 +/- 12.4 years, underwent catheter closure between 6/1995 and 6/2001. One hundred and forty-one had an ischemic stroke, 99 a transient ischemic attack (TIA) or prolonged reversible ischemic neurologic deficit, 5 peripheral arterial embolism, 4 suffered from decompression sickness after diving and 2 had transient global amnesia. Fifty-nine of them had multiple events in spite of antiplatelet or anticoagulant therapy. The patients received five different devices: 13 Rashkind Occluders, 20 Amplatzer septal Occluders, 109 Amplatzer PFO-Occluders, 73 CardioSEAL and 36 STAR-Flex devices. Time of fluoroscopy was 8.3 +/- 4.5 min. In three patients a device embolized and had to be removed from the groin vessels. We saw five inguinal or retroperitoneal venous hematomas with the need for operation in one patient. One early and one late perforation of the left atrium caused by a guide wire and a left-atrial disc, respectively, also needed surgery. Fourteen patients had documented late arrhythmias. Six patients with atrial fibrillation needed drugs or cardioversion while the other patients with runs of supraventricular tachycardia, atrial flutter and multiple extrasystoles needed no therapy. On transesophageal echocardiography (TEE) 6 months after implantation we found four significant residual leaks. These patients had the defect closed with a second device. In addition a secundum atrial septal defect (ASD) was closed in 17 patients (mean age 38 +/- 10.5 years) with Amplatzer septal Occluders (12) and CardioSEAL devices (5). These patients had experienced eight strokes and nine TIAs, 3 of them had had multiple events. Two of these patients had a significant residual defect and one had atrial flutter following the procedure. Two hundred and two PFO-patients and 12 ASD patients were followed for 6-62 (24.6 +/- 14.2) months; 2 died due to a traffic accident and a myocardial infarction, respectively. Four patients had another neurologic event following PFO-closure. We now overlook 210 patients with 348.6 symptom-free patient years and have a 1-year recurrence rate of neurologic events of 1.9%. Catheter closure of the PFO and atrial septal defect is a simple, effective and quick method which ensures a high closure rate, avoids life-long anticoagulation and has a low recurrence rate of neurologic events.

Adolescent↗
PubMed2006

Osseointegration of hollow cylinder based spinal implants in normal and osteoporotic vertebrae: a sheep study.

INTRODUCTION: Osteoporosis is not only responsible for an increased number of metaphyseal and spinal fractures but it also complicates their treatment. To prevent the initial loosening, we developed a new implant with an enlarged implant/bone interface based on the concept of perforated, hollow cylinders. We evaluated whether osseointegration of a hollow cylinder based implant takes place in normal or osteoporotic bone of sheep under functional loading conditions during anterior stabilization of the lumbar spine. MATERIALS AND METHODS: Osseointegration of the cylinders and status of the fused segments (ventral corpectomy, replacement with iliac strut, and fixation with testing implant) were investigated in six osteoporotic (age 6.9 +/- 0.8 years, mean body weight 61.1 +/- 5.2 kg) and seven control sheep (age 6.1 +/- 0.2 years, mean body weight 64.9 +/- 5.7 kg). Osteoporosis was introduced using a combination protocol of ovariectomy, high-dose prednisone, calcium and phosphor reduced diet and movement restriction. Osseointegration was quantified using fluorescence and conventional histology; fusion status was determined using biomechanical testing of the stabilized segment in a six-degree-of-freedom loading device as well as with radiological and histological staging. RESULTS: Intact bone trabeculae were found in 70% of all perforations without differences between the two groups (P = 0.26). Inside the cylinders, bone volume/total volume was significantly higher than in the control vertebra (50 +/- 16 vs. 28 +/- 13%) of the same animal (P<0.01), but significantly less (P<0.01) than in the near surrounding (60 +/- 21%). After biomechanical testing as described in Sect. "Materials and methods", seven spines (three healthy and four osteoporotic) were classified as completely fused and six (four healthy and two osteoporotic) as not fused after a 4-month observation time. All endplates were bridged with intact trabeculae in the histological slices. CONCLUSIONS: The high number of perforations, filled with intact trabeculae, indicates an adequate fixation; bridging trabeculae between adjacent endplates and tricortical iliac struts in all vertebrae indicates that the anchorage is adequate to promote fusion in this animal model, even in the osteoporotic sheep.

Animals↗
PubMed1998

Revisions of endoprosthetic reconstructions after limb salvage in musculoskeletal oncology.

Of 91 limb-salvage procedures using prosthetic reconstructions because of primary or metastatic bone and soft-tissue tumors 26 revisions were performed in 16 patients. Revision was due to polyethylene wear (9 cases), aseptic loosening (8 cases), recurrent hip dislocation (3 cases), prosthetic stem fracture (2 cases), infection (2 cases), leg length discrepancy (1 case), and traumatic dislocation of a saddle prosthesis (1 case). The follow-up period for tumor control varied from 1.5 to 22 years with a median of 13.5 years. The follow-up period after the last revision operation varied from 0.5 to 12 years with a median of 3 years. At the last follow-up, the functional results had deteriorated compared with after the primary operation in 5 patients and had improved in 2 patients. In the remaining patients, the results did not change.

Adolescent↗
PubMed1999

Reactions and complications after the implantation of Endobon including morphological examination of explants.

In the study described here, the integration of hydroxyapatite (HA) ceramic implants (Endobon) was investigated. These implants have an interconnecting system of pores and are free from foreign protein. The material is not toxic, genotoxic, nor zytotoxic, and it is biocompatible. The progress of integration was investigated by means of clinical and radiological check-ups. From 10 patients, it was possible to obtain samples for histological analysis during a second operation (e.g., metal explantation). Microscopic examination showed bony integration with newly formed bone in direct contact with the HA ceramic; it also showed osteoblasts and osteoid seams. No second operation took place earlier than 4 months after the first operation, yet even after this relatively short period, bony integration was already evident. Clinical observation (based on X-rays, reports of pain, signs of inflammation) showed that in most cases healing was taking place without complications. More general operational complications such as thrombosis or nerve injury were observed in 4 patients. If the implant is not sufficiently protected from mechanical stress, bony integation will not take place, and the implant may fracture. HA ceramic, with a porosity between 30% and 80%, is not comparable to cortical bone but only to spongy bone. This factor must be taken into account when deciding whether a HA ceramic implant is indicated.

Adult↗
PubMed2003

Experimental study of a porous rat tracheal prosthesis made of T40: long-term survival analysis.

In order to repair large defects in the laryngotracheal area, we developed a biomaterial based on porous titanium (Ti40) formed of spherical particles that are welded together. These Ti40 beads were arranged in several layers to create the rat tracheal prosthesis. After a partial tracheal resection, the prosthesis was fixed to both extremities to replace the missing part. Tissue surrounding the prosthesis was collected from 33 surviving animals after an implantation period of 3 to 12 months. Histological analyses showed that the periphery of the prosthesis was covered with fibroblasts and a few lymphocytes that penetrated the titanium layers. A ciliary cylindrical epithelium of respiratory type was found on the endoluminal side. The inflammatory reaction observed was minimal. These data indicate that the prosthesis, implanted in a laryngotracheal environment, is well tolerated by animals. Our results represent the first step towards the construction of a total laryngeal prosthesis that should allow restoration of the essential functions of the larynx after a laryngectomy in cancer treatment.

Animals↗
PubMed2004

Therapy of periprosthetical leakage with tissue augmentation using Bioplastique around the implanted voice prosthesis.

Having a voice prosthesis provides a good possibility for speech rehabilitation after total laryngectomy has been performed, especially if common complications such as leakage around the valve can be reduced effectively. The early applications of a voice prosthesis-which was originally invented and applied by Mozolewski in 1972, was further developed by Blom and Singer and became an internationally available implantable instrument by 1980- already made clear not only the typical benefits, but also the complications, such as possible leakage around the implanted valve. Remacle proposed the injection of collagen into the surrounding tissues in order to stop leakage. Knowing that collagen is usually resorbed as time goes by, new substances that can be tolerated by human tissues must be found. This article reports the experiences of the authors in the search for such an injectable material that cannot be resorbed and does not migrate. In order to solve the above-mentioned problem, Lichtenberger introduced the injection of Bioplastique into the perivalvular tissues. This delivered the best results ever achieved in this field at our department. During the past 2 years, Bioplastique augmentation was performed for seven laryngectomized and speech-rehabilitated patients in order to reduce periprosthetical leakage. All procedures were successful in terms of either eliminating or reducing the leakage, and also the non-resorbable property of Bioplastique has been proven.

Adult↗
PubMed2000

The polyurethane nasolacrimal duct stent for lower tear duct obstruction: long-term success rate and complications.

BACKGROUND: The polyurethane nasolacrimal duct stent is used as an alternative to conventional techniques for treatment of lower tear duct obstruction. The aim of this study was to evaluate the clinical success rate after a follow-up of 2 years. METHODS: Nasolacrimal duct stent implantation was attempted in 19 patients with nasolacrimal duct obstruction proven by digital substraction dacryocystography. The median age of the patients was 50 years, and the minimum duration of symptoms was 3 months. Patients were followed up 1 week, 6 months, 1 year and 2 years after the procedure. RESULTS: Eighteen stents were implanted in 17 patients without surgical complications. All stents were proven to be patent at the end of the procedure. Success rate, defined as proportion of patients free of symptoms, was 66.6%, 55.5% and 50% after 1 week, 6 months and I year, respectively, and remained unchanged thereafter. Three stents had to be removed between 6 months and 2 years after implantation. Histological examination showed granulation tissue growing into the opening and obstructing the stent in one case. CONCLUSION: Implantation of a polyurethane nasolacrimal duct stent is an alternative to conventional techniques in lower tear duct obstruction. Its overall success rate is lower than that reported after conventional dacryocystorhinostomy, but the procedure is fast, safe and reversible. Refinement of the surface and stent design may improve results in the future.

Adult↗
PubMed2000

Successful laparoscopic removal of a migrated Angelchik prosthesis.

Implantation of an Angelchik prosthesis has been considered a quick and safe procedure for the surgical treatment of gastroesophageal reflux disease. Since its introduction in 1979 more than 25,000 have been inserted worldwide. However, the use of this device has been largely abandoned because of frequent complications and high costs. One of the more serious complications is migration of the prosthesis, which usually requires open correction. We recently operated on a 49-year-old man with a migrated Angelchik prosthesis. The device, placed 17 years earlier, had now migrated to the free abdominal cavity causing recurrent urinary tract infections and fecal incontinence. The prosthesis was removed laparoscopically via three ports in a simple procedure without any blood loss. Recovery was uneventful. At this writing, complaints have resolved, and reflux is being controlled medically. This case supports the suggestion that Angelchik prosthesis-related problems may be solved laparoscopically, even if the device was inserted via an open procedure.

Adult↗
PubMed2005

Estimation of the stent placement above the intact sphincter of Oddi against malignant bile duct obstruction.

BACKGROUND: In endoscopic biliary stenting against malignant biliary obstruction, stent blockage remains as an important problem. Stent blockage occurs as a result of bacterial adherence to the inner wall of the stent. We evaluated the stent placement above the intact sphincter of Oddi to retain the function of the sphincter of Oddi as a bacteriological barrier. METHODS: Sixteen patients with malignant biliary obstruction were assessed as the patients with the stent above the intact sphincter of Oddi. Sixteen patients with malignant biliary obstruction were assessed as the patients with the conventional stent placement across the sphincter of Oddi. Tannenbaum 10-Fr. stents were used in both the groups. RESULTS: The median patency periods of the stent were 255 days (25th to 75th percentiles, 212-454 days; range, 39-454 days) for the group of the stents placed above the sphincter of Oddi and 82 days (25th to 75th percentiles, 48-131 days; range, 22-196 days) for the group of the stents placed across the sphincter of Oddi, respectively, with significant difference (P = 0.0001). The occlusion rates of stents placed above and across the sphincter of Oddi were 37.5% and 93.8%, respectively, with significant difference (P = 0.0008). The dislocation rates of the stent were 0% and 6.3%, respectively (not significant). CONCLUSIONS: Placement of the stent above the intact sphincter of Oddi was associated with longer stent patency and lower occlusion rate.

Aged↗
PubMed2006

[Evaluation of individual ceramic implants made of Bioverit with CAD/CAM technology to reconstruct multidimensional craniofacial defects of the human skull].

BACKGROUND: Restrictions in the bone structure of the craniomandibular region caused by malformation, traumata or malignant tumours are currently of interest in reconstructive oral and maxillofacial surgery. Methods of autologous bone transplantation are well established for reconstruction of those defects. The reconstruction and remodeling of contour-shaping defects is more difficult due to atrophy and resorption of free-transplantable tissues. Artificially induced harmful effects have been reported on harvesting in the donor area. Further available methods of alloplastic reconstruction are computer-assisted design and manufacturing systems (CAD/CAM). The advantages of individual design and fabrication are obvious in the manufacturing of defect-specific implants. MATERIAL AND METHODS: In the present study the application of individual CAD-based reconstructed bioceramic implants made of Bioverit II was evaluated in the region of the facial skull. Clinical results, patient acceptance and the analysis of the postoperative observation period of 30 months are reviewed. RESULTS: Altogether 25 individual Bioverit ceramics were implanted in the facial region. All patients were satisfied with the aesthetic results of the implantations after primary surgery. Three patients developed a need for further correction during the observation period; one implant fracture was observed. CONCLUSION: Finally, it can be stated that the preoperative expenditures in time, experts, technology and fabrication of individual CAD/CAM planned and manufactured implants are justified by the following advantages: fixed volume, reduced operating time, lack of donor morbidity, easy subsequent treatment of the material and the aesthetic results achieved.

Adult↗
PubMed2003

Breaking strength and tissue elasticity after Shouldice repair.

There are few objective studies in the surgical literature on the strength of an inguinal hernia repair during the immediate postoperative period. To provide the relevant advice and recommendations on physical activities during the period of convalescence, a study on the strength of the Shouldice repair was carried out. Twenty-eight Shouldice repairs were performed on 17 fresh human cadavers (11 male, 17 female, mean age 79.9+/-6.2 years). Following the excision of the transversalis fascia, the breaking strength and tissue elasticity were measured using an automated test device. All tissue ruptures occurred outside the limits of the Shouldice repair. Mean breaking strength was 53.9+/-20.1 N, showing no significant differences between males and females. The measured overall elasticity of tissue samples was 4.6+/-2.3 N/cm. Again there was no marked difference between genders. However, breaking strength and elasticity were found to be significantly affected by age. The Shouldice repair demonstrated a higher tensile strength when compared to the surrounding tissue. Strength after a Shouldice repair of the floor of the inguinal canal was found to be several times higher than could be attained under physiologic conditions. Therefore, an early postoperative return to normal activity can be recommended.

Aged↗
PubMed2006

Assessment of a three-dimensional measurement technique for the porosity evaluation of PMMA bone cement.

In vitro testing of bone cement has historically resulted in the belief that porosity should be minimised to help reduce the risk of prosthesis failure through aseptic loosening. Traditional porosity measurement techniques rely on the analysis of a two dimensional representation of a three dimensional structure. However, with an increasing interest in the number, size and distribution of pores in bone cement, the reliability of a two dimensional approach is questionable. The purpose of this study was to investigate the use of micro computed tomography (micro-CT) for the three dimensional measurement of bone cement porosity by comparison with two traditional techniques. Eighteen bone cement specimens were analysed for porosity using each technique. Levels of agreement between techniques were evaluated, and technique precision was assessed in terms of repeatability and sensitivity to changes in threshold. Micro-CT data was used to illustrate the effectiveness of predicting the porosity of a whole structure from a sample region; an approach often used with traditional techniques. In summary, poor agreement was found between all techniques. However, micro-CT was found to be significantly more repeatable and less sensitive to changes in threshold. The results demonstrated that porosity cannot be reliably determined using traditional techniques and that a large proportion of a specimen is required to provide an accurate porosity measurement.

Biocompatible Materials↗
PubMed1993

Transmolar pin and magnetic carrier for midfacial reconstruction: a clinical report.

With previous prosthetic restorations of bilateral maxillary resections, tissue erosion and bleeding on the cephalic parts of the cavity have been caused by movement and pressure from the prosthesis. Retention of a prosthesis is a major determinant in its successful use. Physical and psychologic stresses are common when one is unable to use a prosthesis comfortably. The use of a musculocutaneous flap and an obturator prosthesis had provided near-immediate reconstruction of a massive midfacial defect. This method of reconstruction resulted in soft tissue replacement for appearance and functional rehabilitation of the upper lip while maintaining sound oncologic principles.

Adult↗
PubMed1994

A quantitative in vitro assessment of fit and screw fixation on the stability of a cementless hemispherical acetabular component.

This investigation quantifies in vitro the effect of component fit, as well as the effect of adjuvant screw fixation, on the initial stability of cementless hemispherical titanium acetabular total hip arthroplasty components and assesses apposition of the acetabular components to bone. Six, fresh human hemipelvi (3 matched pairs) were harvested at autopsy. Titanium alloy acetabular components with a porous surface of commercially pure titanium fiber mesh (Harris Galante Porous acetabular components, Zimmer, Warsaw, IN) were used for implantation. Initially, each acetabulum was underreamed to achieve a 2 mm press-fit with the acetabular component. Pressure-sensitive film had been placed along the dome and medial wall at the bone-implant interface to assess the completeness of seating. After the implant was impacted into the acetabular cavity, relative motion between the implant and bone was measured during simulated single leg stance. Adjuvant fixation of the implant was then obtained with the insertion of four 6.5 mm cancellous screws. High-contrast roentgenograms of the specimens in multiple views were obtained after initial cup insertion and again after screw insertion. The stability of each implant under load was measured with four, three, two, one, and no screws in place. Further reaming of the bone was done to create a 1 mm press-fit. The sequence was then repeated. Further reaming was done to create an exact-fit and the sequence was repeated again. Under these conditions, 1 mm press-fit with or without screws provided the optimum combination of fit stability.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed2005

Incidence and management of abdominal sacrocolpopexy mesh erosions.

OBJECTIVE: This study was undertaken to evaluate the occurrence and management of mesh erosions in patients undergoing abdominal sacrocolpopexy. STUDY DESIGN: A retrospective chart review of the abdominal sacrocolpopexy procedure (n = 92) between 1997 and 2003 was performed. Patients with mesh erosion were identified. Incidence by graft type and treatment required for erosion resolution was analyzed with chi 2 and Fisher exact test. RESULTS: Erosions occurred in 7.6 % (7/92). Erosions were identified only in patients with Gore-Tex (3/33, 9%) or silicone-coated mesh (4/21, 19%) compared with none of 38 patients with polypropylene mesh (n = 24) or fascia (n = 14) grafts ( P = .068.). Partial excision of exposed graft resolved all 3 Gore-Tex erosions, compared with none of the silicone-coated mesh erosions ( P = .03). Complete graft removal was required to resolve silicone-coated mesh erosions. CONCLUSION: We observed a high rate of erosion with Gore-Tex and silicone-coated mesh. Partial graft excision was adequate for Gore-Tex erosions, but complete graft removal was necessary to resolve erosions associated with silicone-coated mesh.

Abdomen↗
PubMed2004

[Can bioprostheses be implanted at younger ages?].

The choice between mechanical prosthesis (MP) and bioprosthesis (BP) depends on the respective advantages and disadvantages of the two types of valves. MP theoretically have an indefinite life span but carry the risk of thromboembolic events that requires anticoagulant therapy, which itself is responsible for hemorrhages. BP bear a theoretically lower thromboembolic risk but have a limited life span that requires reintervention at a subsequent date, latter when the patient is older at implantation and operated on for aortic replacement. Actually MP is preferred before 60 years and BP after 70 years. Between 60 and 70 years there is not consensus. The limit recommended is around 65 years for aortic replacement and 70 years for mitral replacement. This limit can change either for upper or lower limit depending on patient's life expectancy, technological improvements of MP as well as BP, improvements of medical follow up of anticoagulant therapy (either self testing or use of anti thrombin). In the future the age limit of implantation of BP can be lowered but MP didn't have their last word.

Age Factors↗