[BIOPASS hybrid navigation for endoscopic sinus surgery - an assistance system]. / BIOPASS-Hybrid-Navigation für die endoskopische Nasennebenhöhlenchirurgie ­ ein Assistenzsystem.

Previous navigation systems can determine the position of the "tracked" surgical instrument in CT images in the context of functional endoscopic sinus surgery (FESS), but do not provide any assistance directly in the video endoscopic image of the surgeon. Developing this direct assistance for intraoperative orientation and risk reduction was the goal of the BIOPASS project (Bild Ontologie und prozessgestütztes Assistenzsystem). The Project pursues the development of a novel navigation system for FESS without markers. BIOPASS describes a hybrid system that integrates various sensor data and makes it available. The goal is to abandon tracking and exclusively provide navigation information directly in the video image. This paper describes the first step of the development by collecting and structuring the surgical phases (workflows), the video endoscopic landmarks and a first clinical evaluation of the model version. The results provide the important basis and platform for the next step of the project.

[Management of the partial avulsions of the auricle]. / Management der Ohrmuschelteilamputationen.

Injuries of the auricle can range from simple lacerations to complete avulsions. Many techniques of ear replantation have been described in the literature in addition to the type and extent of the involved auricular structures. A direct reattachment of the amputated pinna without microsurgery is rarely successful due to necrosis of the avulsed fragment. Whereas, reconstructions with pocket methods and their variations might lead to better results. In this article we would like to discuss some of these approaches and demonstrate a two-stage reconstruction technique for subtotal avulsion of the auricle.

Modified Nucleosides - Molecular Markers Suitable for Small-volume Cancer?

BACKGROUND: Modified nucleosides (mNS) in urine are shown to be encouraging markers in cancer, mostly in patients presenting with high tumor mass such is breast and lung cancer. To our knowledge, mNS have not been investigated in head and neck squamous cell carcinoma (HNSCC). HNSCC is characterized by early metastasis into locoregional lymph nodes and slow infiltrating growth, but even in the advanced stage exhibits only a relatively low cancer volume. Therefore, reliable distinction between HNSCC and healthy controls by urinary mNS might pose substantial analytical problems and even more as patients with HNSCC mostly have an increased exposure to tobacco smoke and excessive alcohol consumption which affect the renal mNS pattern. MATERIALS AND METHODS: Urinary mNS in samples of 93 therapy-naive patients with HNSCC and 242 healthy controls were quantified by reversed-phase high-performance liquid chromatography. Considering that the circadian rhythm causes diuresis-induced variations in concentration, the mNS-to-creatinine ratio was chosen to compare patients and controls. For sensitivity and specificity in discriminating between patients and controls, the corresponding curve was plotted. Additionally, logistic regression was carried out and a multilayer perceptron neuronal network (NN) was created. RESULTS: Fifteen mNS were detectable in cases and controls; concentrations of 11 were found to be significantly different. The sensitivity and specificity depend on the total volume of the lesion; HNSCC with volume <20 ml was reliably detected, but those with a volume of 20 ml or greater produced amounts of mNS which led to the most accurate detection of HNSCC based on HNSCC-specific mNS patterns. CONCLUSION: Analysis of urinary mNS allows for detection of small-volume HNSCC, with acceptable specificity and sensitivity if the tumor volume exceeds 20 ml.

Functional and cosmetic donor site morbidity of the radial forearm-free flap: comparison of two different coverage techniques.

BACKGROUND: The use of the radial forearm-free flap is a well-established and reliable reconstruction method in head and neck surgery. Usually, the defect of the donor site is covered with full or split-thickness skin grafts. Since 09/2013, a direct closure of the radial forearm donor site has been performed at the ENT University Hospital Leipzig to avoid secondary donor site morbidity. However, few data are available in the literature on long-term cosmetic and functional results compared to the established indirect donor site defect coverage. METHODS: This study investigated patients with radial forearm-free flap harvest from 01/2012 until 03/2015. A total of n = 39 patients were included, with n = 18 being operated by indirect (group 1) and n = 21 by direct closure technique (group 2). For the validation of surgical revisions and wound healing disorders, we carried out clinical investigations as well as interviews. The "POSAS Observer and Patient Scale" was used for assessing the cosmetic outcome and the "Michigan Hand Outcome Questionnaire (MHQ)" for functional criteria. RESULTS: Group 2 showed an increased rate of wound healing problems, however it was not statistically different compared to group 1. Revision surgery was necessary in both groups only each in one case. Using the POSAS, there were no significant differences between both groups in the observer scale for the items vascularity, pigmentation, thickness, relief, pliability, surface area and even for pain, scar itching, color, stiffness, thickness and relief in the patient scale. The functional results (MHOQ) also showed no significantly inferior results for group 2. CONCLUSIONS: The direct closure procedure is quick, simple and can be performed without secondary donor site morbidity. For wound healing, cosmetic and function of the forearm and hand, no inferior results can be measured for the direct procedure compared to the indirect coverage technique.

HLA traits linked to development of head and neck squamous cell carcinoma affect the progression-free survival of patients.

BACKGROUND: Personalized medicine and treatment stratification of patients with head and neck squamous cell carcinoma (HNSCC) today mostly ignore genetic heterogeneity in HNSCC but especially the patient's genetic background. We hypothesized that particular human leukocyte antigen (HLA) class I (HLA-A, B, Cw) and II proteins (DR, DQ) confer susceptibility for and influence development of HNSCC and may be prognostic factors for progression-free survival (PFS). METHODS: 90 consecutive HNSCC patients of the prospective observational cohort study LIFE treated between 08/2010 and 05/2011 at the University Leipzig underwent low resolution typing of HLA-A, B, Cw, DR, and DQ. Antigen and haplotype frequencies were compared to those in German blood donors. Effects on PFS were analyzed using Kaplan-Meier curves and Cox models. RESULTS: HNSCC patients had overall altered HLA-B frequencies (P<0.05); frequencies of B∗44 were lower, those of B∗13, B∗52, and B∗57 increased (P<0.05). Almost all other antigen frequencies showed no deviation. Homozygous HLA-Cw and DRB4 were frequent and associated with reduced PFS (P<0.05). Altered haplotype frequencies were common and particular haplotypes accompanied by differing PFS. B∗13/Cw∗06 carriers had poorest outcome (P=0.011). However, multivariate Cox proportional hazard models revealed 3 clinical covariates (localization oropharynx, loco-regional metastasis, and T4 category), HPV16-DNA positivity, and 10 HLA traits as independent predictors for PFS. CONCLUSIONS: The relevance of the genetic background of HNSCC patients calls for future research to clarify the role of HLA traits in HNSCC and if PFS depends on HLA.

Pediatric nasolacrimal duct obstruction-benefit of a combined therapeutic approach.

BACKGROUND: Pediatric nasolacrimal duct obstruction (PNDO) requires therapeutic intervention after conservative procedures failed. As resilient treatment guidelines for the treatment are missing, the aim of this study was to evaluate the advantages of two different intervention techniques in children with PNDO. METHODS: Between January, 2006 and June, 2014, 233 children (0-208 months) were treated either with conventional probing by ophthalmologists only (Group I) or with endonasal endoscopic interdisciplinary approach (Group II). The clinical outcome was analyzed. RESULTS: The overall success rate of Group I was 93.4% compared to 98.4% of Group II (P<0.05). 50% of all interventions (n=62) of Group II required further surgical procedures in addition to probing/irrigation, particularly with regard to children <6 and >24 months. CONCLUSIONS: Endoscopic control in treatment of PNDO allows exact identification of the stenosis and appropriate surgical intervention with an improved clinical outcome. Endonasal endoscopic surgical techniques should be the standard PNDO treatment.

Induction chemotherapy followed by radiotherapy for larynx preservation in advanced laryngeal and hypopharyngeal cancer: Outcome prediction after one cycle induction chemotherapy by a score based on clinical evaluation, computed tomography-based volumetry and 18F-FDG-PET/CT.

BACKGROUND: Long-term laryngectomy-free (LFS), tumour-specific (TSS) and overall survival (OS) is achieved by non-surgical larynx preservation (LP) only in a proportion of patients with locally advanced laryngeal or hypopharyngeal cancer. A score facilitating decision-making after 1 cycle induction chemotherapy (IC-1) may improve LFS and TSS. METHODS: Early response to IC-1 with TPF ± cetuximab was assessed in 52 patients using endoscopic tumour staging for selecting total laryngectomy for non-responders with endoscopic tumour surface shrinkage <30% versus induction chemotherapy plus radiotherapy (IC + RT) for responders. Computed tomography (CT)-based volumetry was used to assess volumes of primary tumour, neck nodes and their sum; maximum and mean standardised uptake value (SUVmax, SUVmean) were measured by 18F-FDG-PET/CT. Baseline and residual values after IC-1 were calculated and correlated with LFS, TSS and OS. RESULTS: After IC-1, 39/52 patients (75%) were early responders. Early response predicted complete response to IC + RT (p = 8.48 × 10-9). Early laryngectomised non-responders and responders with endoscopic tumour surface shrinkage > 70% had best OS. Significant independent predictors for LFS in responders are number of CT-staged suspect positive neck nodes (N+), residual primary tumour volume, residual total tumour volume and the ratio of residual SUVmax and SUVmean (resSUVmax/resSUVmean). Our LFS-score combines >2N+, residual primary tumour volume > 20%, residual total tumour volume > 5.6 mL and resSUVmax/resSUVmean > 1.51 weighted by their hazard ratio (12, 6, 5 and 4); LFS-score ≤ 16 predicts increased LFS, OS and TSS (p < 0.05). CONCLUSION: LFS-score ≤ 16 identifies in responders to IC-1 the patients with maximum benefit of non-surgical LP achieving long-term LFS. Even more importantly, a LFS-score > 16 defines patients unsuitable for LP applying the TPF/TP IC + RT protocol.

Integrated Multipoint-Laser Endoscopic Airway Measurements by Transoral Approach.

OBJECTIVES: Optical and technical characteristics usually do not allow objective endoscopic distance measurements. So far no standardized method for endoscopic distance measurement is available. The aim of this study was to evaluate the feasibility and accuracy of transoral airway measurements with a multipoint-laser endoscope. METHODS: The semirigid endoscope includes a multipoint laser measurement system that projects 49 laser points (wavelength 639 nm, power < 5 mW) into the optical axis of the endoscopic view. Distances, areas, and depths can be measured in real-time. Transoral endoscopic airway measurements were performed on nine human cadavers, which were correlated with CT measurements. RESULTS: The preliminary experiment showed an optimum distance between the endoscope tip and the object of 5 to 6 cm. There was a mean measurement error of 3.26% ± 2.53%. A Spearman correlation coefficient of 0.95 (p = 0.01) was calculated for the laryngeal measurements and of 0.93 (p < 0.01) for the tracheal measurements compared to the CT. Using the Bland-Altman-Plot, the 95% limits of agreement for the laryngeal measurements were satisfactory: -0.76 and 0.93. CONCLUSIONS: Integrated multipoint-laser endoscopic measurement is a promising technical supplement, with potential use in diagnostic endoscopy and transoral endoscopic surgery in daily practice.

Monitoring of microvascular free flaps following oropharyngeal reconstruction using infrared thermography: first clinical experiences.

The aim of this study is to investigate static and dynamic infrared (IR) thermography for intra- and postoperative free-flap monitoring following oropharyngeal reconstruction. Sixteen patients with oropharyngeal reconstruction by free radial forearm flap were included in this prospective, clinical study (05/2013-08/2014). Prior ("intraop_pre") and following ("intraop_post") completion of the microvascular anastomoses, IR thermography was performed for intraoperative flap monitoring. Further IR images were acquired one day ("postop_1") and 10 days ("postop_10") after surgery for postoperative flap monitoring. Of the 16, 15 transferred free radial forearm flaps did not show any perfusion failure. A significant decreasing mean temperature difference (∆T: temperature difference between the flap surface and the surrounding tissue in Kelvin) was measured at all investigation points in comparison with the temperature difference at "intraop_pre" (mean values on all patients: ∆T intraop_pre = -2.64 K; ∆T intraop_post = -1.22 K, p < 0.0015; ∆T postop_1 = -0.54 K, p < 0.0001; ∆T postop_10 = -0.58 K, p < 0.0001). Intraoperative dynamic IR thermography showed typical pattern of non-pathological rewarming due to re-established flap perfusion after completion of the microvascular anastomoses. Static and dynamic IR thermography is a promising, objective method for intraoperative and postoperative monitoring of free-flap reconstructions in head and neck surgery and to detect perfusion failure, before macroscopic changes in the tissue surface are obvious. A lack of significant decrease of the temperature difference compared to surrounding tissue following completion of microvascular anastomoses and an atypical rewarming following a thermal challenge are suggestive of flap perfusion failure.

Respiratory complications after diode-laser-assisted tonsillotomy.

Children with certain risk factors, such as comorbidities or severe obstructive sleep apnea syndrome (OSAS) are known to require extended postoperative monitoring after adenotonsillectomy. However, there are no recommendations available for diode-laser-assisted tonsillotomy. A retrospective chart review of 96 children who underwent diode-laser-assisted tonsillotomy (07/2011-06/2013) was performed. Data for general and sleep apnea history, power of the applied diode-laser (λ = 940 nm), anesthesia parameters, the presence of postoperative respiratory complications and postoperative healing were evaluated. After initially uncomplicated diode-laser-assisted tonsillotomy, an adjustment of post-anesthesia care was necessary in 16 of 96 patients due to respiratory failure. Respiratory complications were more frequent in younger children (3.1 vs. 4.0 years, p = 0.049, 95 % CI -1.7952 to -0.0048) and in children who suffered from nocturnal apneas (OR = 5.00, p < 0.01, 95 % CI 1.4780-16.9152) or who suffered from relevant comorbidities (OR = 4.84, p < 0.01, 95 % CI 1.5202-15.4091). Moreover, a diode-laser power higher than 13 W could be identified as a risk factor for the occurrence of a postoperative oropharyngeal edema (OR = 3.45, p < 0.01, 95 % CI 1.3924-8.5602). Postoperative respiratory complications should not be underestimated in children with sleep-disordered breathing (SDB). Therefore, children with SDB, children with comorbidities or children younger than 3 years should be considered "at risk" and children with confirmed moderate to severe OSAS should be referred to a PICU following diode-laser-assisted tonsillotomy. We recommend a reduced diode-laser power (<13 W) to reduce oropharyngeal edema.

Endonasal nasolacrimal duct surgery: a comparative study of two techniques.

Dacryocystorhinostomy (DCR) is performed in patients with saccal or postsaccal lacrimal duct obstruction. Focusing on the endonasal approach, we compared success rates, clinical outcome, complications and patient satisfaction of endoscopic vs. non-endoscopic techniques in endonasal DCR. We analyzed the results of 173 patients who underwent an endonasal DCR either utilizing a non-endoscopic (Group I) or an endoscopic technique (Group II) between 2006 and 2011. Irrigation tests followed the first day and at least 3 months after surgery. Postoperative patients' satisfaction and the occurrence of symptoms were documented and evaluated in a follow-up questionnaire. The minor complication rates of both endonasal DCR techniques were similarly low (10%) without severe adverse events. The use of the endoscope prolonged the operating time significantly (28 ± 9 min Group I vs. 34 ± 14 min Group II, p = 0.003). The success rate was 90.2% in Group II compared to only 57.9% in Group I (p < 0.000). Further, we determined the absence of reflux during the irrigation test 1 day after surgery as a significant predictor for the later outcome (R = 1.598, p = 0.005). The follow-up questionnaire revealed a significant improvement in subjectively perceived symptoms by the surgical intervention for both endonasal techniques (p < 0.000). The endoscopically assisted DCR is a safe and successful endonasal technique for patients with saccal or postsaccal lacrimal duct obstructions. The use of the endoscope led to significant higher success rates compared to non-endoscopic techniques in our collective.

A technique with manipulator-assisted endoscope guidance for functional endoscopic sinus surgery: proof of concept.

OBJECTIVE: The goal of this study was to examine the theoretical feasibility of a new manipulator system for endoscope guidance in functional endoscopic sinus surgery. STUDY DESIGN: The accuracy of endoscope positioning and time of endoscope movement with an endoscope manipulator system were determined with an artificial sinus model. SETTING: A laboratory trial was performed. The time for 60 repetitions of manual compared to manipulator-assisted endoscope movements directed at 3 different target positions was evaluated. In addition, the alignment of the position vector for each endoscope movement was examined. SUBJECTS AND METHODS: A zero-degree Hopkins II telescope with a camera was used to head for the target positions. First, the endoscope movements were done manually, and afterward the endoscope manipulator system was used for endoscope guidance. The alignment of the position vector of the endoscope was measured with a portable measuring arm. RESULTS: There was no statistical difference between the time for manual and manipulator-assisted endoscope movements for all target positions. The alignment of the position vector of the endoscope was statistically different at 2 target positions: anterior ethmoid left side and ostium of maxillary sinus left side. There was no statistical difference at all other positions. CONCLUSION: The endoscope manipulator system has the potential to be integrated into the operating workflow without extending the time for endoscope guidance. The surgeon will be able to use both hands for the manipulation of the instruments. Less frequent endoscope movements and instrument changes may be expected after technical modification.

First clinical application of a navigation-controlled shaver in paranasal sinus surgery.

Conventional, pointer-based navigated Functional Endoscopic Sinus Surgery (FESS) has been shown to have certain limitations: necessity of instrument change for navigation, changes in the surgeon's line-of-sight axis, and limited length of use of the navigation information. These limitations result in negative consequences regarding the surgeon's attentiveness in any given situation, as well as in his cognitive work-load. The principle of Navigated Control offers advantages concerning these problems and limitations of the conventionally navigated FESS. This Chapter analyzes the first clinical deployment of a navigation-controlled shaver in FESS on the basis of the following questions: (1) Is clinical deployment of the navigation-controlled shaver possible with the pre-clinic evaluated set-up? (2) What information relevant to the surgery is relayed in an intraoperative setting by the navigation-controlled shaver? (3) How does deployment of the navigation-controlled shaver affect the ergonomics of the surgery? Ten patients with chronic sinusitis ethmoidalis were included in the study (average age: 48 [22-71], m:w=4:6). The preoperative and intraoperative workflow was documented according to the Innovation Center Computer Assisted Surgery (ICCAS) Workflow protocol. Data regarding the surgical validity of the information and ergonomic characteristics were recorded by means of questionnaires. The average time required for segmentation of the workspace was 14.2 minutes. The shaver switched off through Navigated Control an average 16.5 times during an FESS. From this amount, five shutdowns on average were initiative and six were determined to be provoked. The shutdowns were indicated by the operators to be correct in 199 of 220 (90.5%) events and in agreement with the actual position and planned resection borders. The quality of the relayed navigation information was indicated with an average Level of Quality (LOQ) of 56.4 [50-80]. The most favorable evaluation was attained for navigation in the area of the sphenoid sinus with 71 points on average [60-80]. During an FESS, the navigation information led to a change in the planned surgical strategy an average of 0.9 [0-3] times. Throughout all surgical procedures, the situation awareness was assessed an average of 2.7 points better than with the conventionally navigated FESS. This also was the case for the cognitive workload (Workload shift) with 2.8 [1-3.5] points. This Chapter proves the clinical applicability of a navigation-controlled instrument by means of a shaver in Ears, Nose, and Throat (ENT) surgery for the first time. Reproduction of the dental splint registration, manual segmentation of the working space, and attachment of the registration star still prove to be critical aspects. Data regarding quality of the information relayed by the navigation system and resulting change in surgical strategy lead to the conclusion that the authors are dealing with, in the overall evaluation, supplementary and surgically relevant information. This information is more efficiently transferred to the surgeon by means of Navigated Control that allows, according to the following results, both an improved understanding of the information and cognitive easing of stress for the surgeon.