Biomedical subjects

P U Lohnstein

Publications and source records attributed to P U Lohnstein.

6 recordsLinked to original sources

PubMed2007

[Posttraumatic amaurosis after complex frontobasal fracture. Differential diagnosis and therapy].

BACKGROUND: Whether surgical nerve decompression is indicated for the treatment of posttraumatic reduced vision with optic nerve compression in the bony canal has been a subject of controversy for decades. On balance, the recent literature suggests that this procedure is indeed indicated, as a supplement to high-dosed cortisone therapy. The risk of surgery-related side effects is usually rated low in the literature. CASE REPORT: We report on a woman patient in whom craniocerebral trauma involved a fracture of the left optic canal with unilateral loss of vision. In the decompression operation, intraoperative symptoms gave rise to the suspicion of an arteriovenous fistula, which had not been revealed by computer tomography and which was seen as sufficient grounds for discontinuing the procedure. In addition to a carotid artery-sinus cavernosus fistula (CCF Barrow type A), subsequent angiography revealed a dissected aneurysm at the branching of the occluded ophthalmic artery. DISCUSSION AND CONCLUSIONS: In decisions on whether surgical relief of pressure on the optic canal is indicated after trauma-related visual loss, the possibility of secondary lesions near the tip of the orbita and the optic canal must be taken into account. These are not always revealed by computer tomography. The indications should be critically weighed up in each individual case, with additional imaging examinations, such as MR-angiography, CT-angiography, or conventional angiography, performed as needed. The options and indications for imaging are discussed. The procedure can by no means be rated as "minimally invasive", as is postulated by some authors.

Adult↗

PubMed2007

[Sonography aided computer assisted surgery (SACAS) in orbital surgery].

BACKGROUND: The application of computer assisted procedures in orbital surgery is made more difficult by the intraoperative tissue shift in intraorbital structures, since this intraoperative dislocation cannot be imaged in preoperative CT/MR datasets. METHODS: After preoperative recording of CT and/or MR datasets in five patients with orbita affected by frontobasal tumors, we used intraoperative sonography by coupling the ultrasound unit to the navigation system. RESULTS: Registration, referencing and calibration of the ultrasound system proceeded without any difficulties. Intraoperatively, the structures of the anterior and middle thirds of the orbita and their tissue shift could be particularly well evaluated sonographically. CONCLUSION: The use of navigated sonography enables repeated intraoperative re-evaluation of preoperative CT/MR datasets. The fusion of intraoperative sonography with preoperative imaging visualizes the tissue shift and facilitates the identification of anatomical structures and the spatial orientation of the surgeon. This appears to allow both increased operative radicality and greater tissue protection. In our opinion, the intraoperative parallel application of a non-calibrated ultrasound system and an only CT/MRT based navigation system cannot fulfill these requirements because of anatomical complexity.

Adult↗

PubMed2006

[Cochlear protection and surgical precision in stapedotomy with Er:YAG laser].

BACKGROUND: Using laser in stapedotomy has attracted a lot of attention since the nineties. It aims at minimizing complications due to hand-operated equipment, especially inner ear lesions, and achieving higher precision. We analyzed the clinical effect of Er:YAG laser with the question whether the postulated cochlea protection and foot plate perforation, optimized for better sound conduction, are achieved, compared to conventional stapedotomy. PATIENTS AND METHODS: We evaluated retrospectively audiometrical data including pre- and postoperative bone and air conduction thresholds of 114 consecutive patients, on whom we had performed stapedotomy and had inserted platinum-teflon prostheses. The intervention was done conventionally in 72 cases and in 42 cases with Er:YAG laser. RESULTS: In the lower and middle frequencies, laser technique resulted in a more pronounced improvement of bone conduction thresholds compared to conventional stapedotomy. The improvement of air conduction was more distinct in ears after laser surgery; also, the difference between air and bone conduction was reduced at a higher degree. CONCLUSION: Er:YAG laser in stapedotomy is coupled with cochlea protection, as demonstrated under clinical conditions, and allows higher hearing benefit of air conduction compared to conventional stapedotomy. Our results emphasize the impact of innovative laser technique on stapedotomy.

Adult↗

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↗

PubMed2006

[Multidisciplinary management of skull base and craniocervical chordoma].

BACKGROUND: Craniocervical chordomas often only become manifest in an advanced stage. The localisation and locally-destructive growth require a multidisciplinary diagnostic and therapeutic concept early on. The goal of the present study was to present a reproducible strategy for quality assurance. PATIENTS AND METHOD: We retrospectively analysed the hospital records of 10 consecutive patients (4 women and 6 men) whom we had treated during a period of 7 years. RESULTS: The first step in therapy was tumour resection in 9 cases. One patient initially underwent stereotactic radiation. Postoperative radiation was not included a priori, but discussed individually depending on the degree of resection, the patient's age and physical condition. After an average 5 years follow up, 100 % of patients are alive. In all patients, tumour control was achieved. CONCLUSIONS: The prognosis for patients with chordomas of the skull base has improved considerably in recent years. New technologies like intraoperative navigation and improved radiation procedures have contributed to this improvement. The basis for treatment remains, however, the greatest possible surgical exstirpation with minimal surgical morbidity. Special attention should be paid in this connection to the stability of the cervical spine and the craniocervical transition border. In advanced tumour growth, complete resection is often not possible. Proton and heavy-ion radiation are promising new forms of therapy, which can also be applied after conventional radiation has been performed. A directed multidisciplinary procedure guarantees years of survival with good quality of life in many cases.

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↗