Romed Hörmann

The nonrecurrent laryngeal nerve: A clinical anatomic mapping with regard to intraoperative neuromonitoring.

BACKGROUND We investigated the nonrecurrent inferior laryngeal nerve (nrILN), an important variant in the course of the inferior laryngeal nerve (ILN; 0.5-6.0%). Its importance was demonstrated in a clinical case as well as in cadaver specimens, and the pattern was identified with intraoperative neuromonitoring (IONM). METHODS The ILN and the presence of an nrILN were investigated in 36 formaldehyde-embalmed specimens. Our anatomic findings showed differences in the anatomic course of the ILN and thus produced possible explanations for different IONM signals that would correlate with differences in the anatomic course of the ILN. Preoperative ultrasonographic evaluation of the brachiocephalic trunk and the recurrent laryngeal nerve were used for the exclusion or identification of an nrILN, respectively. RESULTS We found 2 nrILNs (ascending, horizontal; 6%) in the anatomic specimens. These 2 specimens each showed an aberrant right subclavian artery (lusorial artery) and were, therefore, associated with the absence of a brachiocephalic trunk. The intraoperative case displayed a descending nrILN. Signals derived from the vagus nerve were positive if derived proximal to and negative if derived distal to the branching of an nrILN. By ultrasonographic identification of a normal brachiocephalic trunk, an nrILN could be excluded. CONCLUSION Surgeons need a working knowledge about nrILNs to avoid recurrent nerve palsy and should be familiar with all the possible course variations in the ILN when IONM signals are absent with vagal stimulation. Moreover, endocrine surgeons need to be able to interpret correctly negative as well as positive signals. Preoperative ultrasonography should ideally be performed, because the presence of a normal brachiocephalic trunk is a quick method to exclude or identify a nrILN.

New laparoscopic approach to the pudendal nerve for neuromodulation based on an anatomic study

The aim was to develop a new laparoscopic technique for placement of a pudendal lead.

Do Ultra-Low Multidetector Computed Tomography Doses and Iterative Reconstruction Techniques Affect Subjective Classification of Bone Type at Dental Implant Sites?

PURPOSE To investigate whether ultra-low-dose multidetector computed tomography (MDCT) combined with the reconstruction techniques filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASIR), or model-based iterative reconstruction (MBIR) alters the subjective classification of revised Lekholm and Zarb (LZ) bone types at prospective dental implant sites. MATERIALS AND METHODS Three cadavers underwent a reference MDCT examination using a standard dose volume (CT dose index [CTDIvol]: 29.4 mGy) and reconstructed with FBP in addition to five test protocols (LD1-LD5) using ultra-low doses (CTDIvol: 4.19, 2.64, 0.99, 0.53, and 0.29 mGy, respectively) and reconstructed with FBP, ASIR 50, ASIR 100, and MBIR. Transverse cross-sectional images of the jawbones were obtained, and three examiners subjectively classified the bone type in each image using the revised LZ classification. The bone type classifications obtained using the reference examination were compared with those obtained from the test protocols for each examiner, and kappa statistic was used to analyze the level of agreement between the reference and test protocols. The clinical significance of the differences was analyzed with Wilcoxon signed rank test. RESULTS Examiners 1 and 2 found moderate to strong agreement between the reference and test protocols, while Examiner 3 found strong to almost perfect agreement (P < .001). The Wilcoxon signed rank test did not demonstrate a clinical significance of the differences between the reference and test protocols for any of the three examiners. CONCLUSION MDCT dose reductions of up to 99% did not significantly alter the subjective classification of bone at dental implant sites.

Localization of the inferior alveolar canal using ultralow dose CT with iterative reconstruction techniques

Objectives: To compare subjective and objective localization of the inferior alveolar canal (IAC) on multidetector CT (MDCT) images obtained by ultralow doses in combination with the reconstruction techniques of filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASIR), or model-based iterative reconstruction (MBIR) as compared to standard dose MDCT and FBP. Methods: Three cadavers were imaged with a reference standard dose MDCT examination (volume CT dose index: 29.4 mGy) reconstructed with FBP and 5 low dose protocols (LD1-5) (volumeCT dose index: 4.19, 2.64, 0.99, 0.53, 0.29 mGy) reconstructed with FBP, ASIR 50, ASIR 100, and MBIR. Linear measurements from the crest of the ridge to the roof of the IAC were recorded. The results from the test protocols were compared with those from the reference using Bland–Altman plots. Results: Only three test protocols allowed the identification of the position of the IAC on all the sample sites: LD1/FBP and LD1/ASIR 100 and LD2/FBP. All three protocols allowed identification of the IAC with comparable results to the reference dose protocol; the 95% confidence interval limits for the measurement differences were ± 0.41 mm, but the differences were not statistically significant. The calculated effective dose for the LD2 protocol, for a scan length of 5 cm, was 27.7 µSv. Conclusions: Using FBP, comparable IAC measurements were achieved with 91% reduction in dose compared with a standard exposure protocol. The use of ASIR and MBIR did not improve identification of the IAC in MDCT low dose images.

Funktionelle Aspekte der Dura sacralis und des anokokzygealen „Verspannungsapparates”

Zusammenfassung Die kaudalen Verankerungsstrukturen des Ruckenmarks mit seinen Hullen, im Speziellen der Dura mater spinalis, sind vielfaltig verspannt. Hierbei sind sowohl die Wirbelsaule als auch Strukturen des Beckenbodens involviert. Diese Verspannungssysteme sind im Rahmen kraniosakraler Techniken von groser Bedeutung. In der folgenden Ubersichtsarbeit ist die Fachliteratur zusammengefasst und die Verankerungsstrukturen werden anhand einer neu geschaffenen anatomischen Bildserie im Detail dargestellt. Dadurch soll der Ubergang von einer rein isolierten Betrachtungsweise zu einem ubergreifenden funktionellen Verstandnis gefordert werden.

Anatomy of the Abdominal Wall: What Is Important for Laparoscopic Surgery?

This chapter is meant to give an overview of the topographic regions of the abdominal wall, thus presenting an anatomic map for a laparoscopic expertise for the following chapters.

Anatomie der Bauchwand aus laparoskopischer Sicht

Die Kenntnis der Anatomie der Bauchwand ist fur eine effektive Reparation von primaren und sekundaren Bauchwandbruchen unverzichtbar. Einige besondere Gesichtspunkte sind bei der laparoskopischen Operation zu berucksichtigen, die in diesem Kapitel beleuchtet werden. Sie sollen zudem den Leser anregen, sich auch mit den weiteren Kapiteln dieses Buches auseinanderzusetzen, um die moglichst beste Operation fur den Patienten durchfuhren zu konnen.