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Biomedical subjects

H F Sailer

Publications and source records attributed to H F Sailer.

At least 19 recordsLinked to original sources
PubMed2002

Slow and continuous application of human recombinant bone morphogenetic protein via biodegradable poly(lactide-co-glycolide) foamspheres.

Bone morphogenetic proteins (BMPs) are multifunctional cytokines that were originally identified as molecules that induce bone and cartilage formation in vivo. In order to increase the efficacy of this potent protein for application in medicine, a carrier system is needed to retain the BMP at the preferred site. Here we present and characterize a slow-release carrier system for pure human recombinant (rh)BMP. The large porous microspheres, called 'foamspheres', are biodegradable, because they consist of poly(lactide-co-glycolide) acids and release loaded rhBMP slowly and continuously. In vivo studies in rodents revealed that rhBMP-loaded foamspheres increased the thickness of the calvarial bone of rats by 222%. When the same amount of rhBMP was applied via a gelatine-based hydrogel, the increase in bone height was only 66%. Thus, the carrier system for rhBMP is an important factor for the efficacy of BMPs.

Absorbable Implants↗
PubMed2001

Disulfide bridge conformers of mature BMP are inhibitors for heterotopic ossification.

Heterotopic ossification is a frequent complication in patients who have suffered head and neck traumas or undergone total hip replacement. Heterotopic ossification occurs when osteogenic precursor cells present at the ectopic site receive the necessary signal(s) to differentiate into osteoblasts. At the protein level, the key factors in differentiation of cells to the osteogenic lineage are BMPs. Stable BMP variants derived from the identical amino acid sequence but with different disulfide bridge configurations have been investigated and found to be capable of inhibiting ossification in vitro and in vivo in rodents. These findings provide a concept for the straightforward development of a novel class of BMP antagonists that could lead to new treatments for traumatically and genetically induced heterotopic ossification and also, possibly, for disorders in which other members of the TGF-beta superfamily are involved.

Animals↗
PubMed2000

Temperature mapping of magnetic resonance-guided laser interstitial thermal therapy (LITT) in lymphangiomas of the head and neck.

BACKGROUND AND OBJECTIVE: Lymphangiomas of the tongue and neck are uncommon benign congenital lymphatic tumors. These vascular lesions are difficult to treat, frequently recur, and can cause patients significant morbidity. Treatment may also be complicated by adjacent vital anatomic structures. Magnetic resonance (MR)-controlled laser-induced interstitial thermotherapy (LITT) has been proven to be a noninvasive safe treatment. Real-time monitoring of tissue temperature with thermosensitive sequences allows controlled coagulation necrosis. STUDY DESIGN/MATERIALS AND METHODS: LITT was performed in a lymphangioma specimen ex vivo. In four patients (eight procedures) with lymphangiomas of the tongue and neck, MR-guided LITT was performed with a percutaneous approach in a multiapplicator technique. The laser system consisted of a titanium catheter and a protective catheter. The dome of the fiber end had a diameter of 1.4 mm with an active length of 20 mm. Temperature sensitive sequences were used in a 0.5 T open-configured MR scanner with the proton frequency shift technique to map the spatial and temporal distribution of Nd:YAG laser effects (7 Watts, 30 pulses per second, 10 minutes/location). Postoperative MR follow-up was performed at 1 week and at 3 months. In three patients, partial resection of the tumor was performed 6 months after LITT. RESULTS: In three patients, MR clearly showed a diminished tumor volume. All four patients reported subjective amelioration and in three patients former functional problems, such as speech and swallowing were improved. MR thermometry allowed accurate demarcation of changes by heat and distinction of affected tumor volume (3.0 cm +/- 0.3 cm). The histology of the patients 6 months after LITT showed laser-induced fibrosis of former lymphatic tissue. CONCLUSION: The results suggest that LITT can be performed safely with tissue preserving of vital structures and can be effective in the treatment of deep tumors, such as lymphangiomas. However, given the nature of the lesion, the potential for recurrence exists no matter what modality is chosen.

Adult↗
PubMed2000

[Bone substitutes].

The application of autogenous bone transplants is still the gold standard for all reconstructive surgery. The wish of surgeons for alternatives to autogenous bone grafts is reflected in the development of a variety of bone graft substitutes of synthetic or biological origin. The following review article is meant to provide the reader with a critical overview of all the alternative materials. In addition, we want to point to the tremendous progress made on this subject, made possible by the joint effort of surgeons and basic researchers. The results of this collaboration show that in the near future a new gold standard for successful reconstructive surgery will emerge and replace the use of autogenous bone transplants.

Animals↗
PubMed2000

The role of a posteriorly inclined condylar neck in condylar resorption after orthognathic surgery.

Recently, it has been reported that a posteriorly inclined condylar neck is associated with condylar resorption following orthognathic surgery, although its role in resorption remains unknown. By cephalometric screening of 240 patients with Angle Class II occlusion 2 years after orthognathic surgery, 11 patients with postoperative condylar resorption were identified. The preoperative posterior inclination of the condylar neck and the surgical risk factors mentioned in the literature, particularly surgically induced counterclockwise rotation of the mandibular proximal segment were evaluated. In all 11 cases, the condylar neck was clearly inclined posteriorly. Counterclockwise rotation of the proximal segment was also observed in all cases, and it amounted to 6.7 degrees (2.5-12 degrees) on average. The contributing role of a posteriorly inclined condylar neck in connection with surgical mandibular movement in postoperative condylar resorption is discussed.

Adolescent↗
PubMed2000

Surgical risk factors for condylar resorption after orthognathic surgery.

OBJECTIVE: The purpose of this study was to look for surgical risk factors for condylar resorption after orthognathic surgery. STUDY DESIGN: Seventeen patients of a group of 452 patients who had undergone orthognathic surgery consecutively and who were in accordance with the inclusion criteria of this study showed postoperative condylar resorption (group I). Preoperative cephalometric characteristics and surgically induced movements of this group were compared with a control group of 17 of 452 patients (group II) in whom postoperative condylar resorption and skeletal relapse did not develop, despite mandibular retrognathism (ANB angle >4 degrees) and high mandibular plane angle (>40 degrees). RESULTS: The kind of osteosynthesis used was not significantly different between the 2 groups. The amount of surgical advancements and the vertical movements of the jaws were not significantly different between the 2 groups. However, the distal (P =.005) and proximal (P =.007) mandibular segments were rotated significantly further counterclockwise in group I. Surgically induced posterior condylar displacement occurred significantly more frequently (P =.007) in group I. CONCLUSIONS: Counterclockwise rotation of the distal and proximal mandibular segments and surgically induced posterior condylar displacement seem to be important surgical risk factors for postoperative condylar resorption. Therefore, these movements seem to be contraindicated in patients who are at high risk.

Adolescent↗
PubMed2000

Diffuse chronic sclerosing osteomyelitis and the synovitis, acne, pustolosis, hyperostosis, osteitis (SAPHO) syndrome in two sisters.

Two sisters with diffuse chronic sclerosing osteomyelitis of the mandible and the humerus and the synovitis, acne, pustolosis, hyperostosis and osteitis syndrome (SAPHO syndrome) are presented. The diagnoses of diffuse chronic sclerosing osteomyelitis at the age of 12 years and 27 years, respectively, were based on typical medical history, clinical symptoms and radiographic, histologic and scintigraphic findings. Because skin lesions and scintigraphic enhancement of the sternoclavicular joints with hyperostosis were present, a SAPHO syndrome was diagnosed in both sisters. Microbiological cultures of biopsy specimens revealed coagulase-negative Staphylococcus aureus at the humerus and Haemophilus parainfluenzae, Streptococcus, Actinomyces and Veilonella species at the mandible. Repeated operative procedures, including decortications, resection and reconstruction, and multiple histologic and microbiologic studies were performed over a period of up to 20 years. Since HLA typing yielded identical gene loci, we suggest that hereditary and autoimmune factors may play a role in the pathogenesis of these cases.

Acquired Hyperostosis Syndrome↗
PubMed2000

Late sequelae after high midface trauma.

The upper midface area comprises mainly the naso-orbito-ethmoidal (NOE) region which plays a paramount role in facial expression. Fractures of this area often result in neglected bony defects in the fragile periorbital region with major secondary impairments such as traumatic telecanthus, orbital dystopia, and/or enophthalmos. Permanent cranial nerve deficits also can occur as the result of post-traumatic/post-operative sequelae. Seventy-one patients (age range 7-78 years) with severe high midface trauma, treated from January 1989 to December 1996, were reviewed with a minimum follow-up of 2 years. The patient population has been distributed according to the fracture type in three groups: Group 1 (n = 35): Isolated NOE with/without associated central midface injury; Group 2 (n = 22): NOE associated with craniofacial injury and Group 3 (n = 14): NOE associated with orbital displacement. The estimated post-surgical parameters included qualitative and quantitative data from the long-term clinical evaluation. Persistent headache and/or concentration difficulties were mainly noted in Group 1. Smell reduction or anosmia was reported mainly in Group 2. Deficits of the trigeminal and/or the facial nerve were found in Group 3. Enophthalmos and/or telecanthus were predominantly seen with injuries associated with orbital displacement.

Adolescent↗
PubMed1999

The Le Fort I osteotomy as a surgical approach for removal of tumours of the midface.

Tumours of the midface and maxillary sinuses have been removed via multiple approaches. The most common approaches are those using incisions in the facial skin, especially in the case of malignant tumours. The Le Fort I procedure via an intraoral incision as described by Sailer in 1986 is a versatile alternative. Combined with a coronal approach and various osteotomies of the upper face it also allows removal of tumours extending into the orbits, the nasoethmoidal complex and the skull base. The versatility of the Le Fort I osteotomy as a surgical approach was analysed in 17 cases. This method is reliable and gives excellent access. Further advantages are the wide surgical exposure and the clear visibility of the resection margins, the absence of visible scars, the feasibility of combining this approach with reconstruction using the buccal fat pad and the possibility of simultaneous placement of bone grafts, insertion of endosseous implants or other preprosthetic procedures via the same incision.

Adipose Tissue↗
PubMed1999

Frontal sinus fractures: computed tomography evaluation of sinus obliteration with lyophilized cartilage.

Allogenic lyophilized cartilage has been proven clinically to be a reliable material for obliteration of the frontal sinus without the limitations of donor site morbidity and the prolongation of the operation time produced by autogenic grafting. The long-term behaviour of the implanted material is of paramount importance for the success of the obliterative technique. This survey included 51 trauma patients on whom obliteration of the frontal sinus with lyophilized cartilage was performed. The fate of the lyophilized cartilage graft was evaluated from computed tomography imaging of the obliterated frontal sinus. No radiological sign of mucocele formation or inflammatory disease was noted. Bone density measurement of the obliterated sinus and the adjacent trabecular bone was calculated. The patient population was distributed into four groups (0-2, 2-4, 4-6, > 6 years) according the postobliterative time. The bone density of the implanted lyophilized cartilage was accentuated from group 1 to group 4 when compared with the bone density of the trabecular bone. This shows the long-term tendency of lyophilized cartilage graft to osseous substitution.

Adult↗
PubMed1999

Update on bioresorbable plates in maxillofacial surgery.

Biodegradable materials, mainly polymers and copolymers of polylactide and polyglycolide, are today routinely used as fixation materials in craniomaxillofacial surgery. Several research groups have shown that these materials can adequately fix osteotomies and fractures of the craniofacial skeleton. Although there are some differences between polymers, in general their biocompatibility is good. They gradually lose their strength, enabling the underlying bone to take up the stress. Secondary procedures for removal of the material causing discomfort and pain are not needed. An overview of the development of biodegradable materials, their characteristics, and illustrations of different applications in craniomaxillofacial surgery are presented. More than 200 patients have been treated successfully so far in our units, the longest follow-up time being now over 7 years. The good results indicate that the use of bioresorbable fixation can be considered routine and will be definitely state of art at the beginning of the new millennium.

Absorbable Implants↗
PubMed1999

Primary chronic osteomyelitis associated with synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO syndrome).

Diffuse sclerosing osteomyelitis may indicate the mandibular localisation of the SAPHO syndrome. Twelve patients with diffuse sclerosis of the mandible were examined for symptoms of the SAPHO syndrome. Nine patients were found to have primary chronic osteomyelitis and eight of these represented a SAPHO syndrome. Results in this series support the hypothesis of an association between primary chronic osteomyelitis and the SAPHO syndrome.

Acquired Hyperostosis Syndrome↗
PubMed1999

Multimodal strategy for reduction of homologous transfusions in cranio-maxillofacial surgery.

The transfusion of homologous blood carries well-known risks that have prompted efforts to develop alternative techniques. Such measures are of particular interest to patients undergoing elective procedures. A total of 204 patients, out of 1470 patients who consecutively underwent major craniomaxillofacial procedures under general anesthesia over a two-year period, were enrolled in a prospective protocol to reduce homologous transfusion requirements when a blood loss in excess of 500 ml was anticipated. The data were compared with the results of a retrospective control group (n=2890) covering major procedures during the previous four years, when blood-saving measures were applied occasionally, but not based on a global strategy. Techniques for the reduction of homologous transfusions were acute normovolemic hemodilution, controlled moderate hypotension, cell saver and predeposit autologous blood. In addition, preoperative administration of human recombinant erythropoietin was introduced during the last year of the study. These techniques were applied individually or in combination, depending on contraindications specific for each technique, using invasive monitoring in order to maintain intraoperative hemodynamic stability. The goal of this study was to examine the extent to which homologous transfusions may be reduced with the systematic application of transfusion-sparing techniques. Of 204 patients qualifying for the transfusion-sparing protocol, 30 received homologous transfusions. In comparison to the control group, utilization of transfusion-sparing techniques had doubled. The overall reduction in the use of homologous transfusions was highly significant. When acute normovolemic hemodilution, controlled moderate hypotension and the cell saver were used in combination, a greater reduction in homologous transfusions was achieved than with the use of either a single modality or combination of any two. No transfusions were required in patients pretreated with erythropoietin.

Adolescent↗
PubMed1999

Alternative methods for reduction of blood loss during elective orthognathic surgery.

Bimaxillary orthognathic surgery and genioplasty are frequently performed to correct dentoskeletal anomalies in otherwise healthy young patients. Until 1990 homologous blood transfusions were routinely necessary for these procedures. The present study describes a protocol of blood-saving measures that was adopted and tested on a continuous sample of 127 patients treated between 1994 and 1997. The protocol comprises acute normovolemic hemodilution, controlled moderate hypotension, positioning the surgical field above the heart level, cell saving, intraoperative homeostasis, preoperative autologous blood donation, administration of recombinant erythropoietin, and acceptance of a low hematocrit perioperatively. This study shows that homologous blood transfusions may be avoided intraoperatively by following the protocol described.

Blood Loss, Surgical↗
PubMed1998

[Preoperative diagnosis of complex craniofacial syndromes].

The aim of this study was to evaluate stereolithography as a tool in craniofacial surgery. The indications were classified according to the usefulness of stereolithography for different craniofacial pathologies. Stereolithography models of 21 patients were built; in three cases two models were made. The age of the 7 male and 14 female patients was 17 years on average (range: 15 months-44 years). First a helical volume CT scan of the anatomical region was performed. After transformation of the data set, the models were built by an SLA 250 stereolithography apparatus (3D-Systems, Valencia, Calif., USA), steered by FORM-IT/DCS-Software (University of Zurich, Switzerland). The stereolithography models were constructed by superposition of epoxy resin slices of 0.05 mm thickness, which were polymerized by a helium-cadmium laser. These models were classified according to the indication for stereolithography, the operation performed, the relevance for surgical planning and the usefulness for the fabrication of implants and protheses. In craniofacial syndromes, severe asymmetries of the viscerocranium, large skull defects and before surgical correction of hypertelorism these models provided important additional information for the surgeon. Before complex interventions in these fields the construction of a stereolithography model should be considered. In multiple fractures consolidated in dislocation, the models proved to be less useful.

Adolescent↗
PubMed1998

[A new device for reproducible computerized tomography in improved diagnosis of surgical maxillofacial conditions].

The aim of this study was the evaluation of a newly developed radiotranslucent headholder (craniostat) in order to improve diagnosis of maxillofacial pathology. In this prospective study, 103 patients with maxillofacial pathology were examined preoperatively with a Philips SR 7000 computed tomograph using this craniostat. The apparatus was applied fixing the patient's head at three points (meatus acusticus externus on both sides and the glabella). The control group consisted of 106 patients with similar pathology who were examined by computed tomography without a headholder. The application of the craniostat resulted in the following advantageous findings: (1) reproducible CT scans, therefore very precise assessment of the course of a disease; (2) fewer motion artifacts; and (3) symmetrical posture of the patient's head. This headholder is helpful in improving maxillofacial diagnosis by computed tomography if a symmetrical, reproducible posture of the patient's head is to be achieved and motion artifacts could otherwise make the interpretation of the resulting images much more difficult.

Adolescent↗
PubMed1998

[Fronto-orbital corrections and development of the frontal sinus].

The development of frontal sinuses following bilateral fronto-orbital advancement is a topic of controversial discussion in the literature. In a retrospective study on 33 patients (15 girls and 18 boys) the development of the frontal sinus was examined radiologically. Only patients with a minimum age of 6 years and with at least 1 year of postoperative follow-up were included. The radiological reference for the frontal sinus development consisted of pneumatisation at or above the level of the supraorbital rims, as projected din postero-anterior cephalograms. According to these criteria a frontal sinus development was seen in 72.7% of our patients. There was no statistically proven correlation between sinus development and the sex of the patient, age at surgery or the amount of advancement. With the exception of severe cases of Crouzon's disease we usually expect normal development of the frontal sinus following bilateral fronto-orbital correction.

Child↗