Biomedical subjects

G J Ridder

Publications and source records attributed to G J Ridder.

At least 19 recordsLinked to original sources

PubMed2006

[Peritonsillar abscess: a life threatening disease--diagnostic and therapeutic aspects].

BACKGROUND: Acute tonsillitis is an extremely common infection seen in children and adults. In most cases, the family doctor is initially consulted. Intratonsillar, peritonsillar and retrotonsillar abscesses are frequent complications in the course of tonsillitis. In those cases, oropharyngeal infection may lead to a descending process with consecutive mediastinitis as a life-threatening condition. PATIENTS AND METHODS: We report the case of a 67-year old man who died of a mediastinitis resulting from a peritonsillar abscess. Clinical findings, radiological diagnostics and antibiotic as well as surgical therapy are illustrated. RESULTS: The patient died due to a septic multi-organic failure despite aggressive antibiotic and surgical therapy by a combined enoral and cervical approach with thoracic drainage. DISCUSSION: Peritonsillar abscess is a potentially life-threatening complication of acute tonsillitis. This must be kept in mind and should therefore lead to an adequate and directed management of this pathology. We discuss the stepwise diagnosis and therapy within the framework of scientific literature.

Aged↗

PubMed2006

[Diagnostic and therapeutic management of a big cyst at the floor of the mouth--a case report].

BACKGROUND: The growth of dysontogenetic cysts at the floor of the mouth is considered as a rare condition. Cysts of the floor of the mouth may be differentiated depending on location or on histopathologic-embryological criteria into dermoids, epidermoids and teratomas. PATIENTS AND METHODS: We report a case of a large cyst at the floor of the mouth and present the results of clinical examination, preoperative diagnostics and surgical approach. RESULTS: The tumour was resected by an enoral operation. Histological findings confirmed a large sublingual epidermoid cyst. There were no complication or relaps during postoperative course. The case is discussed within the framework of scientific literature. CONCLUSIONS: Dysontogenetic cysts should be considered in differential diagnosis of tumours of the floor of the mouth. Diagnostic and surgical management depends first of all on size and location of dysontogenetic cysts.

Adult↗

PubMed2005

The free vastus lateralis flap for reconstruction in ablative oncologic head and neck surgery.

AIMS: The vastus lateralis muscle is an accessory extensor for the knee suitable as a free myocutaneous flap in reconstructive head and neck surgery. We report the use of this muscle as a flap. METHODS: We have used the free myocutaneous vastus lateralis flap for reconstruction following ablative head and neck tumour surgery in six patients. The clinical outcome, time of surgery for flap preparation and anatomosis, follow-up and functional outcome were analysed. RESULTS: Five of our patients showed a very satisfactory functional and cosmetic outcome. Post-operatively, there was no prolonged immobilisation and no limitation of movement to the hip and knee. No unfavourable side-effects at the donor side were noted. CONCLUSIONS: We find this flap a very useful addition to our free myocutaneous flap armamentarium. It has a specific suitability for replacing large defects.

Aged↗

PubMed2005

[Paralyzed face. Ansa-cervicalis-nervi-hypoglossi].

INTRODUCTION: For 100 years hypoglossal-facial nerve anastomosis (HFA) has been a common surgical procedure for reanimation of paralyzed mimic muscles of the face after axotomy of the facial nerve. However, the denervation and subsequent scarred degeneration of the target muscles of the hypoglossal nerve often results in unfavorable late effects for speech and swallowing. Therefore, the ansa cervicalis nervi hypoglossi-facial nerve anastomosis (ACHFA) can be an alternative to avoid such late effects. As a branch of the hypoglossal nerve the ansa cervicalis innervates the infrahyoidal muscles. Neck dissection surgery proved that resection of the ansa cervicalis causes no side effects for swallowing because of several nerve anastomoses to the cervical plexus. PATIENTS AND METHOD: We compared our clinical results of eight cases following a delayed ACHFA with our own experiences after HFA and results from the literature. RESULTS: We found a reanimation rate lower than usually seen after HFA only in the target muscles of the forehead. This may be caused by a reduced neuronal plasticity of the ansa cervicalis. However, in the target muscles of the other two facial nerve branches we observed the same good results one would expect after HFA. There were no late side effects for swallowing and speech though.

Adult↗

PubMed2005

[Computer-assisted surgery (CAS) for the optimal treatment of craniofacial fibrous dysplasia].

BACKGROUND AND OBJECTIVE: The rare bone disease craniofacial fibrous dysplasia is only treated in cases of visible deformities of the splanchnocranium and neurocranium, compression syndromes, and delocation of nasal and paranasal drainage. METHODS AND PATIENTS: In a retrospective quality assessment analysis of six patients with craniofacial monostotic fibrous dysplasia, the indications were analysed for situations in which computer-assisted surgery (CAS) might be helpful. RESULTS AND CONCLUSIONS: CAS serves as an intraoperative basis for the assessment of cosmetic-aesthetic corrections of visible bone deformities of the splanchnocranium and neurocranium, and allows the controlled removal of pathologically affected bone in contralateral symmetry. This seems to be important, especially at the anterior skull base, as deformities of the human face produce strong psychological suffering. Furthermore, CAS allows the configuration of implants for defect reconstruction after focal restorations with bony radical surgery. Implants of various material can be prefabricated from these data, which can then be exactly fitted to cover the defect.

Adult↗

PubMed2005

[Computer assisted methods in reconstructive and function-preserving orbital surgery. New capabilities of computer assisted preoperative surgical planning (CAPP) and computer assisted surgery (CAS)].

BACKGROUND: Orbital reconstruction after tumor or trauma makes high demands on the surgeon when restoring the optic axis and cosmetic features. Computer-assisted preoperative planning surgery (CAPP) and computer-assisted surgery (CAS) allow calculation of the form of the orbital cavity to be reconstructed preoperatively as well as the process of its realization intraoperatively. METHODS: We developed new planning software methods for this surgical procedure. For validation the deviation of accuracy was assessed between the virtual and the real model in eight patients with surgical reconstruction of the orbit. RESULTS: The check of accuracy of the reconstructions compared to the planning of the surgery by fusion of preoperative and postoperative data resulted in a mean deviation of 1.74 mm. The volumetric measurements presented a mean deviation of 0.2 cm(3) with an accuracy of >99%. The accuracy of linear measurements with the techniques of image fusion of the "feature-based" method was 0.38 mm and thus close to the technical threshold of effective data accuracy of 0.35 mm. The enophthalmus could be assessed more objectively with this method compared to using the Hertel index. CONCLUSIONS: CAPP and CAS are helpful in reconstructive orbital surgery to verify the position of the optic axis and the cosmetic result intraoperatively.

Adult↗

PubMed2005

Paragangliomas of the head and neck: diagnosis and treatment.

Paragangliomas of the head and neck (HNP) represent rare tumors of neural crest origin. They are highly vascular neoplasms that are benign in the majority of cases. The site of origin defines the name given those tumors. In the head and neck, they most commonly occur at the carotid bifurcation, where they are referred to as carotid body tumors (CBT). Other common sites of origin are the jugular bulb (jugular paraganglioma; JP), the tympanic plexus on the promontory (tympanic paraganglioma; TP) and the vagal nerve (vagal paraganglioma; VP). Patients with cervical paragangliomas frequently present with a painless, slowly enlarging mass in the lateral neck. In many patients with TP and JP, tinnitus and hearing loss are early symptoms. JP patients often suffer from lower cranial nerve deficits. Evaluation by an imaging modality is necessary to establish the diagnosis. Imaging procedures frequently used include B-mode sonography with color-coded Doppler sonography, computed tomography (CT), magnetic resonance imaging (MRI) and digital substraction angiography (DSA). Debate exists in the literature regarding the different treatment modalities for paragangliomas which include surgery, radiotherapy and stereotactic radiosurgery. The role of preoperative angiography and embolization has also been a matter of discussion. The diagnostic work up and the different treatment options for patients with head and neck paragangliomas will be presented and discussed.

Angiography, Digital Subtraction↗

PubMed2005

[Endoscopic assisted endoluminal stapler-diverticulotomy of Zenker diverticulum].

INTRODUCTION: One of the advantages of endoluminal diverticolotomy in Zenker's diverticulum with the staple is the possibility of early rehabilitation. As the stapler allows to close the cut wound margins of the diverticulum threshold simultaneously with a clip suture, the patient can start oral food intake as early as 24 hours after surgery. The overview for the surgeon for correct placement of the clip device is limited due to the physiological narrowness of the pharyngeal tube. PATIENTS AND METHODS: We reduced the danger of malplacement by placing a temporary stomach tube as well as endoscopic control of the position of the stapler at the diverticulum threshold. RESULTS: 61 patients with Zenker's diverticulum stage Brombart I - IV have been successfully treated with this surgery technique since 1998. In two other patients a transcervical diverticulotomy was done because the diverticulum threshold could not be exposed clearly with the spread laryngoscope. In 10 patients a clinically symptomatical recurrent diverticulum (Brombart stage II) could be safely removed by a repeated endoscopically assisted stapler diverticulotomy. CONCLUSION: The advanced endoscopically assisted endoluminal stapler diverticulotomy in Zenker's diverticulum is convenient for the patient allowing prompt food intake and showing low morbidity and no mortality.

Adult↗

PubMed2004

[The anterosigmoidal approach. A function-preserving surgical method for petroclival tumors].

BACKGROUND AND OBJECTIVE: The antero- or persigmoid approach preserves all functional structures of the petrous bone and, therefore, is an alternative to the classic laterobasal approaches for exploring the petroclival region. As high morbidity is assumed and it is a time consuming procedure, this approach is not well known. METHODS AND PATIENTS: Initially, a cadaver study using computer assisted surgery was used to determine the surgical workflow before we optimized our surgical procedures. RESULTS: In a series of 7 patients with benign tumors growing from the petrous apex to the petroclival region, we were able to resect all tumors completely via the anterosigmoidal surgical corridor using computer assisted surgery. CONCLUSIONS: The navigation-guided anterosigmoidal approach is an excellent method, allowing a good overview of the petroclival region. In patients suffering from complex petroclival tumors, it offers a real chance to achieve complete microsurgical tumor resection without functional defects by an interdisciplinary neuro-oto-surgical session.

Adolescent↗

PubMed2004

[Navigation-controlled cochleostomy. Is an improvement in the quality of results for cochlear implant surgery possible?].

BACKGROUND: The correct positioning of the electrode, which is the limiting factor for the functional integrity of cochlear implants, is decisively influenced by the cochleostomy. Localisation and form of the drilling canal have been solely defined by the surgeon during the operation and an enlargement of the drilling canal is often necessary. Thanks to the improved resolution of new slice imaging techniques, computed tomography allows an exactly defined optimal point for cochleostomy. MATERIAL AND METHODS: In a cadaver study, we examined whether the target defined with computed tomography can be reached in a reproducible way with the help of navigated computer assisted surgery. We chose titanium screw markers as the gold standard for referencing. RESULTS: There was a real deviation of 1.6 mm in the target field. Thus, in a cochleostomy with a diameter of 0.5 mm the goal was not reached in a reproducible way. With this deviation a target of 2.56 mm(2) is defined. CONCLUSIONS: A target assessed by navigation is better than one reached without navigation in view of reproducibility and accuracy. With further technical progress navigated cochleostomy will be possible.

Cadaver↗

PubMed2004

[Neurophysiologic intraoperative monitoring to preserve cranial nerve function in base of skull surgery].

BACKGROUND: Neurophysiologic intraoperative monitoring (NIM) has gone through a renaissance since the advent of computer technology. Currently, both motor and sensory cranial nerves, including the IInd and VIIIth cranial nerves, can be intraoperatively controlled by means of small and mobile systems. PATIENTS AND METHODS: In order to estimate the value of NIM using the new generation of computer systems, we analyzed the records of 379 patients who underwent skull base surgery since 1996. These comprised NIM of the IInd, VIIth, VIIIth cranial nerves in most cases and of the IXth, Xth, XIth, and XIIth cranial nerves in selected cases. RESULTS: Whereas 72% of these cases demonstrated changes in the recorded intraoperative NIM signals, only 29% of them gave evidence of either clinical or electrophysiological neural function alterations during the postoperative follow-up. CONCLUSIONS: NIM is the only available system capable of providing the surgeon with instant intraoperative neural status-related feedback.

Computer Systems↗

PubMed2004

[Does computer-aided navigation of endonasal sinus surgery improve process quality and outcome quality?].

BACKGROUND: Ever since navigation technology was introduced into endonasal surgery, its impact on process and result of surgery has been debated. In this respect, factors of investment costs and additional costs for time exposure will be discussed as well. PATIENTS AND METHODS: In a retrospective analysis of quality assurance, the results of endonasal surgery by surgeons of different experience in 56 patients were evaluated. Preparation time, preoperative setup time as well as time of actual surgery were analysed and compared with possible indications for navigation. RESULTS: From our analysis a classification resulted dividing the indications for navigation into the following four different categories: redundant, reasonable, helpful, necessary. Navigation was redundant when it was dispensable and did not result in a clear improvement of process or outcome quality. Navigation has been proved reasonable when it helped to obtain additional information for improving process quality. It was considered helpful when the information obtained by navigation had an influence at least on the course and/or result of surgery. Navigation was necessary from the surgeon's point of view when the intervention in regard to the benefit-risk-ratio could not be justified without navigation, or only intraoperative slice imaging would allow surgery. CONCLUSION: Not only redundant, but also facultative and obligatory indications for navigation in endonasal surgery result from careful consideration of the risk-benefit-cost ratio. In standardized endonasal sinus surgery, like infundibulotomy or ethmoidectomy, however, navigation can be a hindrance to process quality and does not result in any advantage for outcome quality.

Adult↗

PubMed2004

[Diagnosis and management of cervical paragangliomas: the Freiburg experience].

BACKGROUND: Paragangliomas of the head and neck represent rare tumors of neural crest origin that arise from chemoreceptors. They are highly vascular neoplasms that are benign in the majority of cases. There are controversial discussions concerning the different treatment options for cervical paragangliomas. PATIENTS: Between January 1992 and November 2003 a total of 13 patients with 15 cervical paragangliomas were treated at the Department of Otorhinolaryngology - Head and Neck Surgery, University of Freiburg. Our study includes eight female and five male patients with a mean age of 39.9 years (range: 20 - 79 years). There were 14 carotid body tumors and one vagal paraganglioma. RESULTS: 14 tumors were resected and one underwent primary radiation. In four patients we noted a total of 8 permanent, postoperative nerve deficits. During follow-up no recurrent tumors were seen. CONCLUSION: Complete surgical removal represents the therapy of choice for the majority of cervical paragangliomas. In cases of multiple head and neck paragangliomas or in patients with underlying diseases, primary radiation should be discussed as a treatment option.

Adult↗

PubMed2004

[Etiology and therapy of the internal jugular vein thrombosis].

BACKGROUND: Thromboses of the upper limp and neck are rare in comparison with those of the lower extremities. Internal jugular vein thrombosis (IJVT) is a serious event with a potentially fatal outcome. Complications include pulmonary embolism, sepsis with septic emboli to different organs and tissues as well as intracranial propagation of the thrombus with cerebral edema. As any thrombosis, IJVT is precipitated by Virchow's triad: endothelial damage, alteration of blood flow and hypercoagulability. The history and examination in patients with an IJVT may be vague and misleading. Patients may present with a painful swelling of the neck but they may also be absolutely asymptomatic. Imaging procedures frequently used to diagnose an IJVT include sonography with color-coded duplex sonography, computed tomography, magnetic resonance imaging as well as magnetic resonance venography. Up to date, there is no standardized treatment regimen for patients with an IJVT. PATIENTS AND METHODS: This retrospective study includes all ten patients with an IJVT who were seen at our department between January 2000 and January 2004. There were six female and four male patients. The average age was 49.7 years, ranging from 28 to 79 years. RESULTS: In five cases, the thrombosis was associated with a malignant tumor. In four patients, it was caused by a deep neck space infection and in one case the IJVT was due to cervical, intravenous drug abuse. Two patients were found to be pregnant (one tumor patient and one patient with a deep neck space infection). In all cases, a ten day treatment regimen with intravenous antibiotics and anticoagulant therapy was initiated. Oral or subcutaneous anticoagulation was continued for six weeks to six months. No complications were seen in any patient. In three patients a revascularization of the affected vessel could be demonstrated with color-coded duplex sonography six months after the initial presentation. CONCLUSIONS: Thrombosis of the IJV is probably underdiagnosed. Since the clinical presentation may be vague or misleading, a high degree of suspicion is required to make the diagnosis. The potential complications such as pulmonary embolism or intracranial propagation of the thrombus may be fatal. Whenever the thrombosis is not caused by an inflammatory process, a malignant tumor should be excluded. We recommend a therapy with intravenous antibiotics as well as a systemic anticoagulation. Ligation or resection of the internal jugular vein is reserved for patients who develop complications despite adequate medical therapy.

Administration, Oral↗

PubMed2003

Individual prefabricated titanium implants and titanium mesh in skull base reconstructive surgery. A report of cases.

Titanium implants can be shaped by traditional hand forming, press shaping, modular construction by welding, construction on full-size models shaped from CT coordinates and, most recently, by computer-assisted design and computer-assisted manufacturing (CAD/CAM) that consist in the direct prefabrication of individual implants by milling them out of a solid block of titanium. The aim of our study was to present a set of preliminary cases of an ongoing program of reconstructive procedures of the skull base using titanium implants. The subjects underwent ablative procedures of the skull base with reconstruction either by titanium mesh or individual prefabricated CAD/CAM implants. Six patients have been operated on successfully since 2000: two received prefabricated CAD/CAM titanium plates and four others underwent reconstruction with titanium mesh. The stability of CAD/CAM plates is superior to that of mesh, thus it is more useful in reconstructing large lesions of the frontal skull base and the temporal and occipital bones. Titanium mesh was successfully used for defects smaller than 100 cm(2) or where selected viscerocranial defects are complicated in design and less reproducible by CAD/CAM. The intraoperative design, shaping and adjustment characteristic of titanium mesh can be dispensed with when CAD/CAM implants are used. The 3-D data set used in the CAD/CAM process also operates in the navigated simulation and planning of the ablation contours, the latter being of great assistance in establishing the optimal future defect. As a disadvantage, CAD/CAM technology is more expensive than titanium mesh, and the process is time-consuming as it is carried out in advance of surgery.

Adult↗

PubMed2003

[Microsurgical resection of jugular foramen tumors with hearing preservation and without facial nerve palsy].

BACKGROUND: The juxtacondylar microsurgical approach is an adequate alternative to the classical infratemporal approach for the resection of tumors of the jugular foramen. PATIENTS AND METHODS: Retrospectively, we report on our experience with eight patients suffering from tumors of the jugular foramen with different etiologies, who were treated successfully via the juxtacondylar approach with interdisciplinary cooperation. RESULTS: The advantage of the juxtacondylar approach is that there is no need to expose and transpose the facial nerve. Additionally, reduction or translocation of the posterior wall of the auditory canal and removal of the ossicular chain are not necessary. CONCLUSIONS: Tumors of the jugular foramen can be safely removed without damaging the facial nerve or auditory capacity, with a comparatively much better overview over the vascular and neural structures of the jugular foramen. This more neurosurgically orientated skull base approach is not very well known in the ENT surgical literature.

Adult↗

PubMed2003

[Transvestibular closure with an autologous bone graft as surgical repair of a nasoseptal defect due to Le Fort-I osteotomy].

Defects of the nasal septum are a common complication after nasal surgery. Affected patients frequently suffer from bleeding, crusting and impaired nasal air flow. The surgical closure of septal defects remains a distinctive challenge. Though many different techniques have been described, the failure rate of this procedure remains high. In the case presented here, a large basal septum defect occurred after a prosthetic Le Fort-I osteotomy. The attempt to cover the distance between the bony nasal floor and the nasal septum with pedicled mucosal flaps failed due to extensive scar formation of the nasal mucosa. Therefore a nasal floor elevation by insertion of an autologous bone graft from the iliac crest was conducted. The bone graft was connected with the hard palate via two titanium screws. Other than with an autologous cartilage graft, no major resorption of the bone graft is to be expected. This indirect method for the closure of a basal nasal septum defect is new.

Alveolar Ridge Augmentation↗

PubMed2003

[Undetected hypopharyngeal perforation with deep neck abscess and mediastinitis due to transesophageal echocardiography].

Hypopharyngeal perforation is a rare but dangerous complication caused by diagnostic procedures. If there is any suspicion of perforation of the upper airways and/or upper digestive tract, immediate diagnostic and therapeutic procedures are indicated. Possible complications of a hypopharyngeal perforation are deep neck infection with subsequent mediastinitis and haemorrhage from major cervical vessels, both of which have high mortality rates. We present the case of a 65 year old male patient with perforation of the hypopharynx after transesophageal echocardiography which was unrecognized for more than 1 week. Clinical symptoms of hypopharyngeal perforation may initially be unspecific. Esophagography (Gastrografin administration) and computed tomography as well as esophagoscopy are needed to certify the diagnosis and to evaluate the extent of the lesion. Pathological findings as well as diagnostic and therapeutic needs are demonstrated and discussed.

Aged↗