Georg Philipp Hammer

The Cricothyroid Joint—Functional Aspects With Regard to Different Types of Its Structure

The cricothyroid joint (CTJ) plays a key role in pitch adjustment of the human voice. It allows an external elongation of the vocal fold performed by the cricothyroid muscle with a consecutive stretching and increasing of tension. Phonosurgical methods such as cricothyroid approximation need sophisticated investigations on anatomical and functional principles because of the low satisfaction rates. Fifty cadaveric specimens were analyzed to reveal the morphological and functional anatomy of the CTJ focusing on possible gliding movements in a horizontal and vertical direction. The cartilaginous surfaces of the CTJ were categorized according to Maue and Dickson into three different types (type A: well-defined facet; type B: no definable facet; type C: flat cartilage surface or protuberance) and functional correlations examined. Side different statements and intraindividual differences between male and female specimens were included. Besides from rotational movements, the CTJ allowed horizontal and vertical gliding movements depending on the different types of the cartilaginous surfaces. Especially the difference concerning mobility between type A and the others was highly significant (P<0.001). Two thirds of our specimens showed a similar type in both CTJs, whereas in one third it was asymmetric. In comparison to the possible change of distances between horizontal gliding movements and rotation, rotation caused significant elongation of the vocal folds, which should be proposed in phonosurgical methods for cricothyroid approximation.

Feasibility of Piezoelectric Endoscopic Transsphenoidal Craniotomy: A Cadaveric Study

Objective. Endoscopic transsphenoidal approach has become the gold standard for surgical treatment of treating pituitary adenomas or other lesions in that area. Opening of bony skull base has been performed with burrs, chisels, and hammers or standard instruments like punches and circular top knives. The creation of primary bone flaps—as in external craniotomies—is difficult.The piezoelectric osteotomes used in the present study allows creating a bone flap for endoscopic transnasal approaches in certain areas. The aim of this study was to prove the feasibility of piezoelectric endoscopic transnasal craniotomies. Study Design. Cadaveric study. Methods. On cadaveric specimens (N = 5), a piezoelectric system with specially designed hardware for endonasal application was applied and endoscopic transsphenoidal craniotomies at the sellar floor, tuberculum sellae, and planum sphenoidale were performed up to a size of 3–5 cm2. Results. Bone flaps could be created without fracturing with the piezoosteotome and could be reimplanted. Endoscopic handling was unproblematic and time required was not exceeding standard procedures. Conclusion. In a cadaveric model, the piezoelectric endoscopic transsphenoidal craniotomy (PETC) is technically feasible. This technique allows the surgeon to create a bone flap in endoscopic transnasal approaches similar to existing standard transcranial craniotomies. Future trials will focus on skull base reconstruction using this bone flap.

Lipoaugmentation of the Vocal Folds: A Survey on Alternative Donor Sites for Graft Harvesting

Lipoaugmentation is a treatment option for patients suffering from glottic insufficiency. Autologous fat is a nearly ideal material for vocal-fold augmentation from the view of biocompatibility and viscoelasticity, but there is still the problem of high graft resorption. As distribution and biological behavior of fatty tissue is very different in the human body, the aim of the study was to elucidate possible donor sites with respect to the quantity of harvested fat, the surgical accessibility to the region, the donor site morbidity and possibility of aesthetic defects and the quality of harvested tissue. Possible donor sites for harvesting were examined by magnetic resonance imaging in thirty-five patients with special emphasis to the buccal fat pad, the neck, the dorsolateral side of the proximal upper extremity, the subcutaneous layer of the abdominal wall, the superficial trochanteric region, the medial thigh, and the infrapatellar fat pad. Identified regions that failed to be chosen into consideration because of an elaborate surgical approach (superficial axillarys space, ischio-anal fossa, subcutaneous layer of buttock, popliteal fossa) were not taken into consideration. The mean volume of the buccal fat was 3.994 cm(3); the average thickness of the fat at the level of C7 was 1.721 cm, the mean value in the upper extremities was 1.913 cm laterally and 1.275 cm dorsally. The subcutaneous fat of the abdominal wall was divided into a superficial compartment (mean: 1.527 cm) and a deep one (average: 3.545 cm). In the superficial trochanteric region, the mean thickness was 2.536 cm, in the medial thigh 2.127 cm; the mean volume of the infrapatellar fat pad was 20.198 cm(3). All regions of interest showed reproducible and sufficient amounts of harvestable tissue, we found significant intersexual differences in dorsolateral side of the upper arm, subcutaneous layer of the abdominal wall and superficial trochanteric region. When harvesting subcutaneous tissue of the abdominal wall, grafts of the deep layer should be preferred, in the upper extremity the deep, muscle-neighbored parts. An alternative method is the surgically accessible fat of the neck. Solid fat pads could be harvested from the buccal region or the infrapatellar fat.

Sudden unilateral hearing loss as first sign of cerebral sinus venous thrombosis? A 3-year retrospective analysis.

Introduction Recently, several studies and case reports have dealt with the topic of cerebral sinus venous thrombosis (CSVT) and focused on sudden hearing loss as an early and rare symptom, to diminish the delay in diagnosing this serious disease. Materials and Methods We conducted a retrospective analysis over 3 years and investigated MRIs of all inpatients who were treated for sudden sensorineural hearing loss. The aim of the study was to evaluate whether sudden hearing loss could be an early indicator, or the first sign, of CSVT. Results In total, 554 patients were included. Only 2 patients with CSVT could be identified. In both, sudden unilateral sensorineural hearing loss was not the only symptom. They also reported headache, and 1 patient also reported tinnitus and vertigo. Conclusion In our opinion, sudden unilateral sensorineural hearing loss alone is not a reliable indicator of CSVT. In combination with headache or visual impairment, this rare vascular disease should be taken into account.

Pyramidal apex metastasis as primary manifestation of hepatocellular carcinoma.

As of today, no report exists about a hepatocellular carcinoma metastasis of the pyramidal apex. Most studies describe progressive cancer of the middle ear involving the pyramidal apex (1). Diagnosis of metastasis often is difficult because of occult growth. They mostly become symptomatic when cranial nerves are involved and palsies are seen (2). Hall et al. (3) report one of the first series of breast cancer metastasis in skull base in 10 patients. They report an involvement of cranial nerve V and VII in 60 to 70% of the patients, whereas no intracranial metastasis was reported. As of our knowledge, we report the first case of a metastasis of the pyramidal apex presenting with abducens nerve palsy and trigeminal neuralgia, which had not been diagnosed until transnasal transsphenoidal biopsy confirmed the diagnosis.