Trends in use of lymphadenectomy in surgery with curative intent for intrahepatic cholangiocarcinoma

BACKGROUND

The role of routine lymph node dissection (LND) in the surgical treatment of intrahepatic cholangiocarcinoma (ICC) remains controversial. The objective of this study was to investigate the trends of LND use in the surgical treatment of ICC.

METHODS

Patients undergoing curative intent resection for ICC in 2000-2015 were identified from an international multi-institutional database. Use of lymphadenectomy was evaluated over time and by geographical region (West versus East); LND use and final nodal status were analysed relative to AJCC T categories.

RESULTS

Among the 1084 patients identified, half (535, 49·4 per cent) underwent concomitant hepatic resection and LND. Between 2000 and 2015, the proportion of patients undergoing LND for ICC nearly doubled: 44·4 per cent in 2000 versus 81·5 per cent in 2015 (P < 0·001). Use of LND increased over time among both Eastern and Western centres. The odds of LND was associated with the time period of surgery and the extent of the tumour/T status (referent T1a: OR 2·43 for T2, P = 0·001; OR 2·13 for T3, P = 0·016). Among the 535 patients who had LND, lymph node metastasis (LNM) was noted in 209 (39·1 per cent). Specifically, the incidence of LNM was 24 per cent in T1a disease, 22 per cent in T1b, 42·9 per cent in T2, 48 per cent in T3 and 66 per cent in T4 (P < 0·001). AJCC T3 and T4 categories, harvesting of six or more lymph nodes, and presence of satellite lesions were independently associated with LNM.

CONCLUSION

The rate of LNM was high across all T categories, with one in five patients with T1 disease having nodal metastasis. The trend in increased use of LND suggests a growing adoption of AJCC recommendations in the treatment of ICC.

Accuracy of near-patient vs. inbuilt spirometry for monitoring tidal volumes in an in-vitro paediatric lung model

Spirometric monitoring provides precise measurement and delivery of tidal volumes within a narrow range, which is essential for lung-protective strategies that aim to reduce morbidity and mortality in mechanically-ventilated patients. Conventional anaesthesia ventilators include inbuilt spirometry to monitor inspiratory and expiratory tidal volumes. The GE Aisys CS² anaesthesia ventilator allows additional near-patient spirometry via a sensor interposed between the proximal end of the tracheal tube and the respiratory tubing. Near-patient and inbuilt spirometry of two different GE Aisys CS² anaesthesia ventilators were compared in an in-vitro study. Assessments were made of accuracy and variability in inspiratory and expiratory tidal volume measurements during ventilation of six simulated paediatric lung models using the ASL 5000 test lung. A total of 9240 breaths were recorded and analysed. Differences between inspiratory tidal volumes measured with near-patient and inbuilt spirometry were most significant in the newborn setting (p < 0.001), and became less significant with increasing age and weight. During expiration, tidal volume measurements with near-patient spirometry were consistently more accurate than with inbuilt spirometry for all lung models (p < 0.001). Overall, the variability in measured tidal volumes decreased with increasing tidal volumes, and was smaller with near-patient than with inbuilt spirometry. The variability in measured tidal volumes was higher during expiration, especially with inbuilt spirometry. In conclusion, the present in-vitro study shows that measurements with near-patient spirometry are more accurate and less variable than with inbuilt spirometry. Differences between measurement methods were most significant in the smallest patients. We therefore recommend near-patient spirometry, especially for neonatal and paediatric patients.

Diagnostik des »Sentinel Lymph Node« bei malignem Melanom: präoperative Lymphszintigraphie und intraoperative Sondenmessung

Ziel: Der »sentinel lymph node« (SLN) reflektiert den Befall der nachfolgenden Lymphknoten-Stationen bei Patienten mit malignem Melanom und hat damit eine erhebliche prognostische Bedeutung. Ziel der Studie war die prä- und intraoperative Lokalisierung dieses Lymphknotens mittels Lymphszintigraphie und Sondenmessung. Methoden: 38 Patienten mit malignem Melanom (Tiefenausdehnung >0,75 mm) wurden nach Injektion von 40 MBq 99Tc-Nanocoll szintigraphisch untersucht. Die Position des ersten im Abflußgebiet dargestellten Lymphknotens wurde an der Haut markiert. Unmittelbar danach wurde intraoperativ mittels einer kollimierten Sonde dieser Lymphknoten aufgesucht und nach Ex- stirpation die Aktivität des Knotens und die Restaktivität im Operations- situs gemessen. Ergebnisse: Bei allen Patienten konnte der SLN szintigraphisch lokalisiert und markiert werden. Vor und nach Exstirpation wurde die höchste Aktivität mit der Sonde im markierten Lymphknoten bestimmt. Makroskopisch und im Ultraschall und CT waren alle Lymphknoten unauffällig. Histologisch zeigten acht Patienten eine Metastasierung im lokalisierten Lymphknoten, die bei sieben Patienten eine großzügige Ausräumung des gesamten nachfolgenden Lymphgebietes nach sich zog. Schlußfolgerungen: Die vorgestellte Methode bietet die Möglichkeit, den morphologisch unauffälligen SLN sicher aufzufinden. Die operative Entfernung des diagnostisch erkannten SLN kann eine grundlegende Zäsur in der Therapie des malignen Melanoms bedeuten, da nur bei positivem Befund eine großzügige Lymphknoten-Ausräumung durchgeführt wird. Die kombinierte Lymphszintigraphie mit Sondenmessung beeinflußt entscheidend das therapeutische Vorgehen aufgrund der sicheren Lokalisation des Lymphknotens und ermöglicht hierdurch eine individuelle Therapieplanung.

Lymphsequenzszintigraphie für die nichtinvasive Langzeitbeobachtung des funktionellen Therapieerfolges nach Transplantation autologer Lymphgefäße

Ziel: Die autologe Lymphgefäßtransplantation führt bei bestehendem Lymphödem zu einer signifikanten Verbesserung der Lymphabflußverhältnisse. Die vorliegende Studie untersucht, ob die Lymphsequenzszintigraphie geeignet ist, die persistierende Funktion autologer Lymphgefäßtransplantate und damit den Erfolg dieser Operationsmethode zu dokumentieren. Methoden: In die Studie gingen die Daten von 20 Patienten (17 Frauen und 3 Männer) ein. Anlaß für die Operation war in 4 Fällen ein primäres, in 16 Fällen ein sekundäres Lymphödem. Szintigraphi-sche Analogaufnahmen mit semiquantitativer Beurteilung des Lymphtransportes erfolgten als Ausgangsuntersuchung vor Transplantation und anschließend über einen Zeitraum von sieben Jahren. Ergebnisse: Bei 17 von 20 Patienten (Transplantationssitus: obere Extremität n = 12, untere Extremität n = 8) war postoperativ eine persistierende Verbesserung des Lymphtransportes im Vergleich zur präoperativen Situation an einem signifikanten Abfall der Transportindices nachweisbar. Bei 5 Patienten gelang zusätzlich die direkte szintigraphische Darstellung der Lymphgefäßtransplantate. In diesen Fällen konnte postoperativ ein signifikant höherer Abfall der Transportindices im Vergleich zu Patienten ohne szintigraphisch darstellbares Transplantat beobachtet werden. Lediglich 3 der 20 Patienten zeigten keine Besserung im Vergleich zur Ausgangssituation. Schlußfolgerungen: Somit erwies sich die Lymphsequenzszintigraphie mit semiquantitativer Einschätzung der Lymphabflußverhältnisse vor und nach autologer Lymphgefäßtransplantation als einfache, nicht invasive Untersuchungsmethode zur objektiven Beurteilung des Therapieerfolges im Langzeitverlauf. Eine szintigraphisch direkte Darstellung des autologen Lymphgefäßtransplantats scheint einen prognostisch günstigen Faktor bezüglich der postoperativen Lymphdrainage darzustellen.

Metastases in patients with malignant melanoma despite of negative sentinel lymph node: Has the concept to be changed?

Aim: The Sentinel Lymph Node (SLN) is of considerable prognostic relevance, because extended lymph node dissection may not be performed in patients presenting with histologically negative SLN. The aim of the present study was to prove the prognostic value of the SLN-concept in these patients. Methods: So far the clinical follow-up of 162 patients with histologically proven malignant melanoma and metastatically uninvolved (negative) SLN was investigated. Histological examination included standard methods (HE-Test) and special histochemical techniques (S-100, HMB-45). All patients underwent clinical examination, ultrasonic diagnosis of the regional lymph nodes, and x-ray of the chest every 3 months. Results: Despite of negative SLN-findings in 8/162 patients metastases of the malignant melanoma were found after a time period of 5-27 months. Three patients presented with recurrence in the previously mapped (negative) SLN-basin. In another case the scintigraphically visualized SLN could not be identified intraoperativelly by means of the hand-held gamma probe. One patient showed intransit-metastases or skin-metastases, respectively; another patient recurred in the scar area. One patient showed hematogenic dissemination (liver) which is not detectable by lymphoscintigraphy; in another patient metastases were found outside the primary lymphatic basin (cervical). Conclusion: In our patient group 4,9% presented with metastases despite negative SLN while published data report up to 11% (observation period 35 months), among them only 3 patients (1,9%) being real concept failures. Our results underline that there is no evidence to change this concept in patients with clinically early stage.

The clinical yield of SPECT/CT for the assessment of lymphatic transport disorders

Ziel dieser Studie war zu untersuchen, ob die zusätzliche Bildgebung mittels SPECT/CTTechnik den diagnostischen Wert der planaren Lymphszintigraphie bei Patienten mit Lymphtransportstörungen verbessern kann. Patienten, Methoden: Über einen festgelegten Zeitraum von zwei Jahren wurden 36 konsekutive Patienten (27 Frauen, 9 Männer, Alter 27–87 Jahre) in unsere Studie eingeschlossen. Zusätzlich zur planaren Lymphszintigraphie wurden weitere ergänzende SPECT/CT-Akquisitionen der betroffenen Extremitäten oder des Körperstamms durchgeführt. Insgesamt erfolgte eine prospektive Auswertung von 48 anatomischen Lymphabflussregionen mittels planarer Szintigraphie und tomographischer SPECT/CT. Ergebnisse: In 28/48 Fällen (58%) brachte die SPECT/CTBildgebung klinisch relevante Zusatzinformationen im Vergleich zur planaren Technik; darunter 27 bezüglich der exakten anatomischen Lokalisation der Transportstörungen sowie 8 Fälle, bei denen die Ausdehnung der lymphogenen Störung mittels SPECT/CT ausgedehnter beurteilt wurde als in der alleinigen planaren Szintigraphie. In 3 Fällen konnte durch die SPECT/CT differenzialdiagnostisch zwischen Lymphknoten versus Lymphozele differenziert werden. In keinem der Fälle konnten Lymphgefäße/-transplantate durch die morphologische CT-Komponente dargestellt werden. Schlussfolgerungen: Die zusätzlich zur planaren Lymphszintigraphie durchgeführte SPECT/CT präzisiert die anatomische Zuordnung lymphogen bedingter Transportstörungen und somit die Abschätzung der Ausdehnung der Pathologie. Des Weiteren löst sie Überlagerungseffekte anatomischer Strukturen durch die tomographische Akquisition auf und ermöglicht die Differenzialdiagnose von Lymphknoten versus Lymphozelen.

First experiences with a new radiopharmaceutical for sentinel lymph node detection in malignant melanoma

Aim of this study was to localize the sentinel lymph node by lymphoscintigraphy using technetium-99m colloidal rhenium sulphide (Nanocis®), a new commercially available radiopharmaceutical. Due to the manufacturers’ instructions it is licensed for lymphoscintigraphy. Patients, methods: 35 consecutive patients with histologically proved malignant melanoma, but without clinical evidence of metastases, were preoperatively examined by injecting 20-40 MBq Nanocis® with (mean particle size: 100 nm; range: 50-200 nm) intradermally around the lesion. Additionally blue dye was injected intaoperatively. A hand-held gamma probe guided sentinel node biopsy. Results: During surgery, the preoperatively scintigraphically detected sentinel lymph nodes were identified in 34/35 (97%) patients. The number of sentinel nodes per patient ranged from one to four (mean: n = 1.8). Histologically, metastatic involvement of the sentinel lymph node was found in 12/35 (34%) patients; the sentinel lymph node positive-rate (14/63 SLN) was 22%. Thus, it is comparable to the findings of SLN-mapping using other technetium-99m-labeled nanocolloides. Conclusion: 99mTc-bound colloidal rhenium sulphide is also suitable for sentinel node mapping.

Lymph kinetics with technetium-99m labeled radiopharmaceuticals

Aim of this study was to characterize suitable technetium- 99m labeled tracers for lymphoscintigraphy by comparative animal tests. Animals, methods: To evaluate the influence of the particle size and the organ tracer-uptake on lymphtransport animal experiments were performed on six different agents (including one control group). Activity distributions were examined in Sprague-Dawley-rats by lymphoscintigraphy; the maximum uptake (count-rate) of the whole body and in lymph nodes were analyzed by regions- of-interest-technique, respectively. Additionally, for characterization of lymphatic and extralymphatic traceruptake an intra-individual relative count-rate ratio of the liver, lung, kidneys, and spleen has been calculated following organ extraction. Results: Organ specific differences of distribution were clearly demonstrated. Our results indicate that the kinetics of lymphoscintigraphic 99mTc-bound agents substantially depends on particle size. Reliable transport from the interstitium to initial lymph vessels and lymph node uptake suggested for tracers suited for lymphoscintigraphy a median size of about <100 nm. Conclusion: Our data could improve standardization of diagnostic methods and lead to an objective consideration of therapeutic procedures.

Radiation exposure of patients undergoing nuclear medicine procedures in Germany between 1996 and 2000

The aim of this study was to estimate both the frequency and effective dose of nuclear medicine procedures performed in Germany between 1996 and 2000 for different subgroups of patients. Methods: Electronically archived data from 14 hospitals and 10 private practices were restored and statistically analyzed. The effective dose per examination was calculated according to ICRP publication 80 using the tissue weighting factors given in ICRP publication 60. Based on the data collected, statistical parameters were computed to characterize the frequency and effective dose of the various nuclear medicine procedures. Results: In total, 604,771 nuclear medicine procedures performed in 433,709 patients were analyzed. On average, 1.4 examinations were carried out per patient and year. The median effective dose was 1.7 [5.-95. percentile; mean: 0.4–8.5; 2.9] mSv per examination and 2.3 [0.5–11.2; 3.5] mSv per patient. Interestingly, the mean effective dose per examination, but not the number of examinations per year increased with the age of the patients. Most frequent were examinations of the thyroid (36.7%), the skeleton (27.1%) and the cardiovascular system (11.1%), which were associated with a median effective dose of 0.5 [0.5–1.1; 0.7] mSv, 3.4 [2.9–5.1; 3.6] mSv and 7.3 [3.2–21.0; 9.5] mSv, respectively. Over the five-year period examined, the total annual number of PET procedures (222.3%) as well as of examinations of thyroid (24.5%), skeleton (17.9%), and the cardiovascular system (14.9%) increased markedly, whereas a decrease was observed for brain (-39.3%), lung (-20.2%) and renal (-15.0%) scans. Conclusion: The age- and gender-specific data presented in this study provide detailed public health information on both the current status and recent trends in the practice of diagnostic nuclear medicine examinations.

Aquisition of age- and sex-dependent patient data for the calculation of annual radiation exposure in nuclear medicine: a German pilot study

Aim: A pilote study for estimation of radiation exposure due to diagnostic procedures in nuclear medicine using routine data of hospitals and practices in Germany. Methods: Hospitals and practices willing to participate in the study supplied data of one year (1997), containing information on patients´ identification number, age, sex, type of diagnostic procedure, radiopharmaceutical, administered activity, type of health insurance (private/ public), inpatient/outpatient status, and so-called Leistungsziffer, which describes the type of medical performances in Germany. The effective dose per examination was calculated according to ICRP 80. Mean, standard deviation, median, 5th and 95th percentiles of the effective dose were calculated, stratified by type of organ system and also by sex and age, including patients of ≥18 years. Results: 82 039 examinations from patients of 9 hospitals and practices were analyzed. The median (5-95th percentiles) of the effective dose per examination for all patients was 2.9 mSv (0.4-8.5 mSv); 1.2 examinations per patient and year were performed on average. The three most frequent examinations were bone scans (median 3.4 mSv; 2.9-5.1), thyroid (0.9 mSv; 0.4-2.2) and cardiovascular studies (7.3 mSv; 3.8-20.2). The median effective dose for 18 to 40 years old women was 1.0 mSv (0.4-5.8), for women between 41 and 65 years 2.2 mSv (0.4-7.3) and for women older than 65 years 2.4 mSv (0.5- 7.6). The corresponding values for men were 2.6 mSv (0.3-7.6); 3.3 mSv (0.4-9.1), and 3.4 mSv (0.5- 8.8). Conclusion: It was possible to gain an accurate determination of radiation exposure of diagnostic procedures in nuclear medicine by routine data.

The hitchhiker's guide to quantitative diffusion measurements

Quantitative comparison of three widely used techniques for diffusion measurements, implemented on a light sheet microscope.

Effectiveness of tip rotation in fibreoptic bronchoscopy under different experimental conditions: an in vitro crossover study

Background

Proper manipulation of fibreoptic bronchoscopes is essential for successful tracheal intubation or diagnostic bronchoscopy. Failure of proper navigation and rotation of the fibrescope may lead to difficulties in advancing the fibrescope and might also be responsible for (unnecessary) difficulties and delays in fibreoptic tracheal intubation, with subsequent hypoxaemia. The present study, therefore, aimed to assess the effectiveness of tip rotation in flexible bronchoscopes in different experimental conditions.

Methods

Five differently sized pairs of fibrescopes (outer diameters of 2.2, 2.4, 3.5, 4.2, and 5.2 mm) were inserted into paediatric airway manikins via an appropriately sized laryngeal mask and were turned clockwise or anticlockwise at the fibrescope body or cord to 45, 90, and 180°, with the cord held either straight or bent. The primary outcome measure was the ratio of rotation measured at the tip over the rotation performed with the fibrescope body or cord.

Results

Overall, the 'body' turn was significantly less effective when a bent cord was present (mean difference ranging from 29.8% (95% confidence interval 8.8-50.9) to 117.4% (93.6-141.2). This difference was diminished when the 'cord' turn was performed. Smaller fibrescopes, with outer diameters of 2.2 and 2.4 mm, were inferior with respect to the transmission of 'body' rotation to the tip.

Conclusions

'Cord' turning of the fibrescope appears to be more effective in rotating the tip than a turn of the fibrescope 'body' only. Straightening the fibrescope cord and combined 'body' and 'cord' turning are recommended.

Early versus late recurrence of intrahepatic cholangiocarcinoma after resection with curative intent

BACKGROUND

The objective of this study was to investigate the characteristics, treatment and prognosis of early versus late recurrence of intrahepatic cholangiocarcinoma (ICC) after hepatic resection.

METHODS

Patients who underwent resection with curative intent for ICC were identified from a multi-institutional database. Data on clinicopathological characteristics, initial operative details, timing and sites of recurrence, recurrence management and long-term outcomes were analysed.

RESULTS

A total of 933 patients were included. With a median follow-up of 22 months, 685 patients (73·4 per cent) experienced recurrence of ICC; 406 of these (59·3 per cent) developed only intrahepatic disease recurrence. The optimal cutoff value to differentiate early (540 patients, 78·8 per cent) versus late (145, 21·2 per cent) recurrence was defined as 24 months. Patients with early recurrence had extrahepatic disease more often (44·1 per cent versus 28·3 per cent in those with late recurrence; P < 0·001), whereas late recurrence was more often only intrahepatic (71·7 per cent versus 55·9 per cent for early recurrence; P < 0·001). From time of recurrence, overall survival was worse among patients who had early versus late recurrence (median 10 versus 18 months respectively; P = 0·029). In multivariable analysis, tumour characteristics including tumour size, number of lesions and satellite lesions were associated with an increased risk of early intrahepatic recurrence. In contrast, only the presence of liver cirrhosis was independently associated with an increased likelihood of late intrahepatic recurrence (hazard ratio 1·99, 95 per cent c.i. 1·11 to 3·56; P = 0·019).

CONCLUSION

Early and late recurrence after curative resection for ICC are associated with different risk factors and prognosis. Data on the timing of recurrence may inform decisions about the degree of postoperative surveillance, as well as help counsel patients with regard to their risk of recurrence.

Comparison of a paediatric emergency ruler with a digital algorithm for weight and age estimation

BACKGROUND

Emergency tapes like the "Paediatric-Emergency-Ruler" (PaedER) provide drug dosing and recommend medical airway equipment based on estimated patient bodyweight and age. Previous studies have revealed unsatisfactory accuracy in bodyweight estimation, due to the tapes' length-based weight categories. Therefore, we developed a digital algorithm allowing continuous length-based estimation of weight and age. The aim of this study was to compare the new algorithm with the PaedER regarding accuracy in estimating bodyweight and recommendation of medical airway equipment.

METHODS

Patients with a body length suitable for the PaedER were included in this single centre, prospective clinical observation trial after obtaining informed written parental consent. Bodyweight estimations by the algorithm and PaedER within ± 10% and ± 20% of the actual bodyweight were compared. Furthermore, medical airway equipment suggested by the PaedER and algorithm were compared with the equipment actually used for anaesthesia. Wilcoxon- and McNemar-Tests were used for statistical analysis. Results are median (interquartiles), P < 0.05 was considered significant.

RESULTS

In total, 489 patients aged 2.0 years (0.4-5.9), with a body length of 89.0 cm (63.5-114.5), weighing 12.8 kg (6.3-19.6), were included. The algorithm's precision of bodyweight estimation within ± 10%/± 20% was significantly higher at 64.0%/91.6% than the PaedER at 55.4%/81.8% (P < 0.001). Compared to PaedER the algorithm showed a higher incidence of correctly recommended medical airway equipment based on its accuracy for age and bodyweight estimation.

CONCLUSION

The new digital algorithm is an alternative to conventional emergency tapes, showing improved accuracy regarding length-based estimation of bodyweight and recommendation of medical airway equipment.

Complement C5a-Induced Changes in Neutrophil Morphology During Inflammation

The complement and neutrophil defence systems, as major components of innate immunity, are activated during inflammation and infection. For neutrophil migration to the inflamed region, we hypothesized that the complement activation product C5a induces significant changes in cellular morphology before chemotaxis. Exposure of human neutrophils to C5a dose- and time-dependently resulted in a rapid C5a receptor-1 (C5aR1)-dependent shape change, indicated by enhanced flow cytometric forward-scatter area values. Similar changes were observed after incubation with zymosan-activated serum and in blood neutrophils during murine sepsis, but not in mice lacking the C5aR1. In human neutrophils, Amnis high-resolution digital imaging revealed a C5a-induced decrease in circularity and increase in the cellular length/width ratio. Biomechanically, microfluidic optical stretching experiments indicated significantly increased neutrophil deformability early after C5a stimulation. The C5a-induced shape changes were inhibited by pharmacological blockade of either the Cl-/HCO3--exchanger or the Cl^- -channel. Furthermore, actin polymerization assays revealed that C5a exposure resulted in a significant polarization of the neutrophils. The functional polarization process triggered by ATP-P2X/Y-purinoceptor interaction was also involved in the C5a-induced shape changes, because pretreatment with suramin blocked not only the shape changes but also the subsequent C5a-dependent chemotactic activity. In conclusion, the data suggest that the anaphylatoxin C5a regulates basic neutrophil cell processes by increasing the membrane elasticity and cell size as a consequence of actin-cytoskeleton polymerization and reorganization, transforming the neutrophil into a migratory cell able to invade the inflammatory site and subsequently clear pathogens and molecular debris.

Intraoperative music application in children and adolescents - a pilot study

BACKGROUND

Hospitalization, surgery and anaesthesia may lead to new-onset maladaptive behaviour, emotional distress and trauma. This pilot study aims to investigate the influence of intraoperatively applied music on post-operative behaviour in children and adolescents.

METHODS

Children with an ASA physical state classification of I or II, aged from 4 to 16 years and scheduled for elective circumcision or inguinal hernia repair under combined general and caudal anaesthesia were included. The children were randomized into two groups. They wore headphones during surgery, and were either exposed to music or not. All involved staff were blinded. Post-operative behaviour was documented by parents on day 7, 14 and 28 after surgery, using a questionnaire adapted from the "Post Hospitalization Behavioural Questionnaire" (PHBQ). Overall occurrence of at least one item indicating maladaptive behaviour was the primary outcome. Data are presented as median (interquartile range).

RESULTS

In total, 135 children aged 6.6 (5.3-8.5) years, weighing 22 (19-29) kg, were included, with 112 completed questionnaires returned. Overall occurrence of at least one maladaptive item was lower in the music group, with a significantly lower incidence on day 7 (51% vs. 77% in controls; P < 0.01).

CONCLUSION

Intraoperative music application in children undergoing minor surgical procedures may reduce the incidence of post-operative maladaptive behaviour within the first week.

Physical determinants of asymmetric cell divisions in the early development of Caenorhabditis elegans

Asymmetric cell divisions are of fundamental importance for the development of multicellular organisms, e.g. for the generation of founder cells. Prime examples are asymmetric cell divisions in germline precursors during the early embryogenesis of the transparent roundworm Caenorhabditis elegans, one of the major developmental model organisms. However, due to a lack of quantitative data it has remained unclear how frequent unequal daughter cell sizes emerge in the worm’s early embryogenesis, and whether these originate from sterical or biochemical cues. Using quantitative light-sheet microscopy, we have found that about 40% of all cell divisions in C. elegans until gastrulation generate daughter cells with significantly different volumes. Removing the embryo’s rigid eggshell revealed asymmetric divisions in somatic cells to be primarily induced by steric effects. Division asymmetries in the germline remained unaltered and were correctly reproduced by a model based on a cell-size independent, eccentric displacement of the metaphase plate. Our data suggest that asymmetric cell divisions, imposed by physical determinants, are essential for establishing important cell-cell interactions that eventually fuel a successful embryogenesis.

Validation of 2 noninvasive, markerless reconstruction techniques in biplane high-speed fluoroscopy for 3-dimensional research of bovine distal limb kinematics

Lameness severely impairs cattle's locomotion, and it is among the most important threats to animal welfare, performance, and productivity in the modern dairy industry. However, insight into the pathological alterations of claw biomechanics leading to lameness and an understanding of the biomechanics behind development of claw lesions causing lameness are limited. Biplane high-speed fluoroscopic kinematography is a new approach for the analysis of skeletal motion. Biplane high-speed videos in combination with bone scans can be used for 3-dimensional (3D) animations of bones moving in 3D space. The gold standard, marker-based animation, requires implantation of radio-opaque markers into bones, which impairs the practicability for lameness research in live animals. Therefore, the purpose of this study was to evaluate the comparative accuracy of 2 noninvasive, markerless animation techniques (semi-automatic and manual) in 3D animation of the bovine distal limb. Tantalum markers were implanted into each of the distal, middle, and proximal phalanges of 5 isolated bovine distal forelimbs, and biplane high-speed x-ray videos of each limb were recorded to capture the simulation of one step. The limbs were scanned by computed tomography to create bone models of the 6 digital bones, and 3D animation of the bones' movements were subsequently reconstructed using the marker-based, the semi-automatic, and the manual animation techniques. Manual animation translational bias and precision varied from 0.63 ± 0.26 mm to 0.80 ± 0.49 mm, and rotational bias and precision ranged from 2.41 ± 1.43° to 6.75 ± 4.67°. Semi-automatic translational values for bias and precision ranged from 1.26 ± 1.28 mm to 2.75 ± 2.17 mm, and rotational values varied from 3.81 ± 2.78° to 11.7 ± 8.11°. In our study, we demonstrated the successful application of biplane high-speed fluoroscopic kinematography to gait analysis of bovine distal limb. Using the manual animation technique, kinematics can be measured with sub-millimeter accuracy without the need for invasive marker implantation.

[Single incision laparoscopy : Current status]

BACKGROUND

Since the introduction of single incision laparoscopy (SIL), there has been disagreement among professional societies regarding a general recommendation for the use of this minimally invasive method.

OBJECTIVES

Determination of evidence-based advantages of SIL compared to multiport laparoscopy (MPL).

MATERIALS AND METHODS

Description of recent technical developments and evaluation of prospective randomized clinical trials and valid meta-analyses with regard to organ-specific procedures. In addition, an expert opinion is provided based on 4209 SIL interventions.

RESULTS

SIL is nowadays applied in all fields of general and visceral surgery. Due to the initial enthusiasm, methodologically weak studies were often published in the literature. Any beneficial effect of SIL on reduced perioperative morbidity is not clearly confirmed, yet. A better cosmetic outcome is either obvious (in SIL liver resections) or nearly unverifiable (in SIL cholecystectomies).

CONCLUSION

SIL has proven feasible and safe after getting through the learning curve. Scientific evidence is currently insufficient to justify SIL without reservation in particular without the individual technical experience of the surgeon.