Biomedical subjects

J Schipper

Publications and source records attributed to J Schipper.

At least 19 recordsLinked to original sources

PubMed2006

[The transverse rectus abdominis muscle (TRAM) flap. A "second defensive line" in microvascular reconstructions of defects in the head and neck area].

BACKGROUND: The microvascular anastomosed transverse rectus abdominis muscle (TRAM) island flap has been successfully used in plastic surgery for more than 10 years. In reconstructive head and neck surgery, however, it is not yet established. METHOD: We analysed the preparation and anatomical variation in TRAM flaps in an examination of eight cadavers. In a clinical case with complete reconstruction of the nose after nasal ablation and complete loss of a radial lower forearm flap that had been transplanted previously due to a recurrent tumor, the possibility of forming and modeling a TRAM flap is demonstrated. RESULTS: The flap vessels of the TRAM are comparable to the radial forearm flap, and the donor site may be primarily closed. The TRAM proved to be a suitable alternative to close lesions of the head and neck area in selected cases. The myocutaneous TRAM is bulkier than the fascio-cutaneous radial forearm flap. The subcutaneous abdominal fat of the TRAM can be reduced in relation to the vascular distribution of the perforator vessels. If the subcutaneous fat of the flap is reduced, the flap can be shaped and formed well. In the described case, it was used to close the lesion after ablation of the nose and middle face. CONCLUSION: The risk of an iatrogenic lesion of the peritoneal fascia or postsurgical herniation of the abdominal wall is low if several surgical prerequisites are taken into consideration. The myocutaneous TRAM will not replace the fascio-cutaneous radial forearm flap in microvascular head and neck surgery, but the large diameter of the donor vessels and the highly vascularized flap tissue makes it an alternative as a second line procedure in cases of unfavorable wound conditions.

Cadaver↗

PubMed2006

[Skull base chondrosarcoma. An interdisciplinary challenge].

BACKGROUND: Chondrosarcoma is a rare differential diagnosis of malignant tumours of the skull base. The prognosis was rated as unfavourable in articles for many years. It has, however, improved considerably in recent years. The objective of this study was to evaluate and current, new optimised treatment strategies. PATIENTS AND METHODS: We retrospectively analysed the case histories and course of four patients whom we treated for chondrosarcoma of the skull base over the past 5 years at the Freiburg Skull Base Centre. RESULTS: Because of initially mild symptoms, the patients first came for examination at an advanced stage of the tumour. All patients underwent surgery, whereby an R0-resection was barely or only questionably present. Three patients underwent radiation therapy postoperatively. All patients are currently tumour free. CONCLUSIONS: Surgical treatment with curative intent is basically the therapy of choice. Due to the usually large size of the tumour and its close relationship to relevant structures, complete resection is, however, not always possible despite advances in surgical procedures. Taking the possibility of modern adjuvant radiotherapeutic procedures into account, an incomplete, function-preserving resection is preferred to a radical and mutilating resection.

Adult↗

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

[Information assisted surgery as a transdisciplinary surgical procedure].

BACKGROUND: Information assisted surgery (IAS) is a further development of the computer assisted surgery (CAS) exclusively for intraoperative localization serving as basis for future technologies such as mechatronic and robotic. It requires of the surgeon a turnaround from traditional surgical proviso as well as transdisciplinary knowledge in the areas of surgical medicine, radiological imaging and information. The advantage of IAS is the predictability of the surgical procedure according to the specifications of modern quality assessment. METHOD: We analyzed the possibilities for the application of IAS in interdisciplinary transfacial surgery of the frontobasis in 9 patients with different pathologies of the central skull base and the cranio-cervical junction and compared this to conventional CAS. RESULTS: We determined retrospectively with a quality assessment analysis that surgery planning is too time consuming in the moment, and that the necessary transdisciplinary knowledge for IAS cannot be taken for granted yet. IAS has not been consequently applied for the entire surgery process in any of the 9 cases. This was due to technical difficulties as well as large intraoperative accuracy deviations of more than 5 mm. CONCLUSION: Even though the highly-developed technology of IIAS -- intelligent information assisted surgery -- is available, with the possibility of half or fully automatic implementation of IIAS including a automatic re-referencing, this technology will not be used in medical navigation for strategic reasons.

Adenoma↗

PubMed2005

[CAS in rhino-surgical procedures in the growing age].

BACKGROUND: Rhinosurgery in children and adolescents meets special requirements: Limited cooperation and reduced limits for the organ dose for ionizing radiological examinations aggravate diagnostics. On the other side, bone sutures and bone growth areas have to be respected intraoperatively, and regions of bones not yet calcified have to be distinguished from possible tumor infiltration. Computer assisted surgery (CAS) can help to identify these areas safely. METHOD: 5 patients, from the first to the 20 (th) year of life, suffering from tumors, malformation syndromes or therapy resistant nasal polyposis were treated with CAS in rhinosurgery. RESULTS: In addition to radiological diagnostics, we performed 3D computed tomography of the skull for CAS. CAS enabled us to intraoperatively respect possible areas of bone growth, to identify regions with thin, not bonily developed cranial vault and to safely distinguish bone sutures from ethmoidal cells. CAS helped the surgeon to navigate in the not yet developed paranasal sinus system. CONCLUSIONS: CAS is a useful complementary method in rhinosurgery of the developing skull of the child. In spite of the additional 3D computed tomography, the calculated organ dose of the ocular lense amounted to 5 millisievert, so a recommended maximal organ dose for the ocular lense of 15 millisievert was not exceeded.

Adolescent↗

PubMed2005

[LED autoregistration in navigated endonasal sinus surgery].

BACKGROUND: In endonasal sinus surgery, computer aided surgery (CAS) is a generally accepted method. Applying CAS, there are basic problems with the constancy of accuracy at a free mobile patient head as well as with extended referencing time. The navigation system manufacturer Stryker-Leibinger invented together with our working group a non-invasive, frameless, automatic patient registration and simultaneous tracking system for navigated endonasal sinus surgery. With this new user-friendly system it concerns an active, LED-based, self-adhesive on the surface of splanchnocranium autoregistration mask. MATERIAL AND METHOD: The LED autoregistration mask was tested in an anatomic cadaver study and an ongoing clinical patient study regarding manageability, applicability and accuracy. Accuracy measurements were accomplished on different control points of the head in the cadaver study. The determination of accuracy was calculated with the metric Euclidean distance. Further we report on our experiences with a total of 20 patients applying the new mask. To control the accuracy, anatomic landmarks of the patients were adducted. Goal of our study was to determine the accuracy of the LED mask and to compare it with titanium screw markers, the valid reference gold standard. RESULTS: The LED autoregistration mask convinced by a high precision with relatively simple useability. Total accuracy amounted to 2.22 +/- 0.91 mm. The LED system proved to be a valuable orientation guide mainly at revision surgeries with modified anatomy. CONCLUSIONS: LED surface autoregistration is especially suitable for endonasal sinus surgery and represents a very helpful tool for the rhinosurgeon. Our accuracy studies have shown that the LED autoregistration mask is comparable to the gold standard titanium screw markers and, in addition, very reliable.

Computer Graphics↗

PubMed2005

[Methods for evaluation of perimodiolar ci electrode arrays in human temporal bones].

BACKGROUND: Cochlear implants (CI) are the established treatment for cochlear deafness. Recently, indications for cochlear implantation have been expanded to include severely hearing-impaired patients. The use of bilateral implants seems to provide additional benefit. Moreover, new electrode designs, i. e. perimodiolar electrode arrays, aim at improving benefit for patients. However, in addition to providing functional improvements, modern electrode array development must also address safety aspects, because damage to the cochlear morphology (especially the osseous spiral lamina) may lead to degeneration of residual neuronal structures and bony obliteration or scarring within the cochlear ducts. METHODS: Therefore, insertion trauma of the newly developed electrode arrays in human temporal bones must be evaluated before applied to patients. Several methods for testing electrode location and intracochlear trauma are described. RESULTS: Combining cross-sectional imaging, histological analysis and elements of risk-assessment valid information about trauma and possible consequences for use in patients can be determined, based on our experience in 57 temporal bones. CONCLUSIONS: Following our results, safety studies with prototype electrode arrays should, in addition to radiological examination, always include careful histomorphological evaluation.

Adult↗

PubMed2005

[The interesting case -- case no. 67].

BACKGROUND: Lipoma of the retropharyngeal space is a rare benign tumour often showing unspecific clinical symtoms. It can grow to an enormous extent causing total obstruction of the upper respiratory tract. Until now its etiology is unknown. With a variety of differential diagnoses, a diagnostic concept is necessary. CASE REPORT: A 41 year old male patient complained about a nondolent swelling of the neck. The radiological diagnostics showed a huge lipoma of the para- and retropharyngeal space with subtotal obstruction of the pharynx. The lipoma was removed completely via transcervical approach. CONCLUSION: Lipoma as differential diagnosis of retropharyngeal tumours always has to be considered. Surgical intervention is recommended. To prevent functional complications resulting from tumour and surgery and to get information about the extent of the lipoma, accurate radiological imaging is mandatory.

Adult↗

PubMed2005

[The influence of insertion depth on the preservation of residual hearing after cochlear implantation].

BACKGROUND: Cochlear implantation may be indicated in patients with bilateral severe sensory hearing loss. Patients with minimal residual hearing have more benefit from cochlear implantation than from optimal fitted hearing aids. However, it has to be considered that inner ear structures might be damaged during electrode insertion. METHODS: We analysed the influence of insertion depth on the preservation of residual hearing in 47 cochlear implant patients (type of implant: Nucleus 22 M or 24 M) by using the pure tone audiometry. Frequency-specific analyses of pre- and postoperative audiograms on the implanted side were performed, evaluating only frequencies above 500 Hz. The insertion depth was documented by stiffening rings outside the cochlea. RESULTS: Residual hearing was more obtained in cases with complete insertion of the electrode array than in those cases with incomplete insertion. In the frequencies 1000 and 4000 Hz these results are significant. CONCLUSION: In our opinion, the perceived resistance producing intracochlear damages and preventing the complete electrode-insertion at the same time is an explanation for the significantly poorer results of the patients with incomplete insertion.

Audiometry, Pure-Tone↗

PubMed2005

[The freiburg incision for cochlear implantation -- initial results].

BACKGROUND: Cochlear implant surgery is a well standardized therapy for rehabilitation of congenital or acquired deafness at all ages. Mastoidectomy, posterior tympanotomy, cochleostomy and electrode insertion are performed consistently worldwide. Recently newly developed types of incision are taken into account. In our experience over more than 15 years the extended endaural incision has proven to be reliable with a low complication rate. OBJECTIVE: To evaluate a modified retroauricular incision for clinical use and complication rate in cochlear implant surgery with devices of different manufacturers. MATERIAL AND METHODS: We performed a prospective analysis of cochlear implant surgeries between 03/2003 and 03/2004. In all cases a modified retroauricular incision was used. Necessary adaptations of incision, depending on the device used, and postoperative complications were evaluated. RESULTS: In 76 ears a retroauricular incision was performed. Depending on the shape and size of receiver/stimulator an extension of the incision was necessary. The mean observation time was 6.3 months. Intra- or postoperative complications were not observed. In one case a skin dehiscence following trauma 28 days after surgery was reported without dehiscence of fascia or implant failure with uneventful healing after secondary suture. CONCLUSIONS: With regard to the results with the extended endaural incision the modified retroauricular incision allows a safe access for cochlear implant surgery. Observation of long term results and outcomes in revision surgery is mandatory.

Adolescent↗

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

[Paragangliomas of the head and neck. Part 2: Therapy and follow-up].

Paragangliomas of the head and neck are preferably treated surgically. Planning the surgical approach for temporal bone paragangliomas is performed according to the Fisch classification. Small temporal paragangliomas can be removed in a transtympanic or transmastoidal procedure. Locally advanced paragangliomas of the head and neck have to be embolized presurgically. An occlusion test is also recommended to check the possibility of a resection of the internal carotid artery. Type C and D temporal bone paragangliomas can be removed by different infratemporal approaches. Alternatively, some type C(1,2 )and De,i(1,2) temporal bone paragangliomas can be removed via variations of the juxtacondylar approach. Glomus caroticum tumors are resected transcervically. In cases of contraindications for surgery or in palliative situations radiotherapy is recommended.

Carotid Arteries↗

PubMed2004

[Paragangliomas in the head-/neck region. I: Classification and diagnosis].

Paragangliomas of the head and neck occur sporadically or are hereditary. The hereditary phenotype characteristically occurs between the 2nd and 3rd decade of life; the sporadic phenotype beyond the 4th decade. The hereditary phenotype "paraganglioma syndrome type 1" frequently shows multilocular tumor manifestations and rarely cases of maltransformation. Therefore, paragangliomas should be considered a systemic disease. For diagnosis, an interdisciplinary, step by step procedure is mandatory comprising genetic screening, whole body medical check-up including catecholamine metabolism, and optionally an 18F-Dopa-PET and localised imaging procedures.

Diagnosis, Differential↗

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

[Current developments in cochlear implantation].

Over the last 20 years, cochlear implantation has become a well accepted treatment in patients suffering from hearing loss or congenital deafness. Results have been impressive,and indications for a cochlear implant have been extended continuously. Thanks to a sophisticated diagnostic procedure, optimization of the surgical technique, and the progression of interdisciplinary cooperation in the field of rehabilitation, the acceptance of cochlear implantation is growing significantly. The manufacturers of the devices are making great efforts to miniaturize the external components of the system, and new developments in electrode arrays, combined with new speech coding strategies, result in better speech understanding. The new developments in electrode design, however, are not necessarily improvements over recent years. Nevertheless, a very well functioning network of physicians, scientists, and manufacturers has acted and reacted in an outstanding manner to identify possible causes of post-implantation meningitis, have taken immediate counter measures and presented possibilities of prevention.

Cochlear Implantation↗