In vivo implantation of a tissue engineered stem cell seeded hemi-laryngeal replacement maintains airway, phonation, and swallowing in pigs

Laryngeal functional impairment relating to swallowing, vocalisation, and respiration can be life changing and devastating for patients. A tissue engineering approach to regenerating vocal folds would represent a significant advantage over current clinical practice. Porcine hemi-larynx were de-cellularised under negative pressure. The resultant acellular scaffold was seeded with human bone marrow derived mesenchymal stem cells and primary human epithelial cells. Seeded scaffolds were implanted orthotopically into a defect created in the thyroid cartilage in 8 pigs and monitored in vivo for 2 months. In vivo assessments consisted of mucosal brushing and bronchoscopy at 1, 2, 4, and 8 weeks post implantation followed by histological evaluation post termination. The implanted graft had no adverse effect on respiratory function in 6 of the 8 pigs; none of the pigs had problems with swallowing or vocalisation. Six out of the 8 animals survived to the planned termination date; 2 animals were terminated due to mild stenosis and deep tissue abscess formation, respectively. Human epithelial cells from mucosal brushings could only be identified at Weeks 1 and 4. The explanted tissue showed complete epithelialisation of the mucosal surface and the development of rudimentary vocal folds. However, there was no evidence of cartilage remodelling at the relatively early censor point. Single stage partial laryngeal replacement is a safe surgical procedure. Replacement with a tissue engineered laryngeal graft as a single procedure is surgically feasible and results in appropriate mucosal coverage and rudimentary vocal fold development.

[Postoperative implant-associated osteomyelitis of the shoulder: Hardware-retaining revision concept using temporary drainage]

BACKGROUND

Posttraumatic and postoperative osteomyelitis (PPO) is a subgroup of bone infections with increasing importance. However, to date no standardized reoperation concept exists particularly for patients with PPO of the shoulder region. Therefore the purpose of this study was to evaluate a revision concept including débridement, irrigation, and insertion of temporary drainage with hardware retention until healing.

PATIENTS AND METHODS

A total of 31 patients with PPO were included with a proximal humerus fracture (n = 14), clavicle fracture (n = 10), or AC-joint separation (n = 7). In all, 27 of these patients could be followed for > 1 year.

RESULTS

Hardware retention until fracture or ligament healing could be achieved in > 83%. Six patients required follow-up débridement due to recurrent infections, but then were unremarkable. Clinical outcome showed excellent Constant scores (91.6 ± 2.8).

CONCLUSION

A cost-efficient, simple, and successful revision concept for patients with PPO of the shoulder region is described.

[Infected knee prostheses. Part 2: chronic late infections]

OBJECTIVE

Treatment of late and chronic infections, which require the replacement of all the infected implant material.

INDICATIONS

All infections lasting more than 4 weeks that have been proven to be bacterial and/or obvious signs of infection.

CONTRAINDICATIONS

Unsuitable for anesthesia, high acute infection with sepsis and risk for bacteremia with danger to life, large soft tissue damage where plastic surgery coverage is not possible.

SURGICAL TECHNIQUE

Arthrotomy, synovectomy, removal of all foreign bodies including all residue of polymethylmethacrylate (PMMA), jet lavage, spacer, drainage, wound closure or temporary closure using vacuum sealing.

POSTOPERATIVE MANAGEMENT

Bed rest with a leg brace and drainage until daily drainage volume is <50 ml, then mobilization with no weight-bearing in an orthesis, 4 weeks systemic antibiotics, after 2 weeks without antibiotics aspiration of the joint, when no bacteria are found reimplantation of a revision TKA (total knee arthroplasty) and with plastic surgery for coverage (gastrognemius flap) if necessary, when bacteria are found again revision with exchange of the spacer.

RESULTS

In the literature, the success rate for both the one-stage or the two-stage procedure is about 80-95%. In our very nonhomogeneous collective the overall rate of success is about 81%.

[Juvenile neuronal ceroid lipofuscinosis. Ophthalmologic findings and differential diagnosis]

Neuronal ceroid lipofuscinoses (NCL) are a heterogeneous group of neurodegenerative diseases with mostly autosomal recessive inheritance whose common feature is the intralysosomal accumulation of ceroid lipofuscin. With varying manifestation ages the diseases result in cognitive and motor deterioration, epilepsy, diffuse retinal degeneration, and eventually death. Juvenile ceroid lipofuscinosis (JNCL, CLN3, Batten disease) has the distinctive feature that the ophthalmologic symptoms precede the neurologic symptoms by several years, and thus the ophthalmologist plays a central role in early diagnosis. Important clinical signs of JNCL include bull's eye maculopathy, severely reduced Ganzfeld ERG already at initial presentation, and unusually rapid progression of the functional decline. If JNCL is clinically suspected the diagnosis can be made by means of a standard blood smear and confirmed by genetic detection of the mutation. Although causal therapeutic options are currently only in the developmental stage, early diagnosis by the ophthalmologist is of utmost importance to allow for medical and educational support of the affected child and for adequate counseling of the parents.

Slow breathing reduces sympathoexcitation in COPD

Neurohumoral activation has been shown to be present in hypoxic patients with chronic obstructive pulmonary disease (COPD). The aims of the present study were to investigate whether there is sympathetic activation in COPD patients in the absence of hypoxia and whether slow breathing has an impact on sympathoexcitation and baroreflex sensitivity. Efferent muscle sympathetic nerve activity, blood pressure, cardiac frequency and respiratory movements were continuously measured in 15 COPD patients and 15 healthy control subjects. Baroreflex sensitivity was analysed by autoregressive spectral analysis and the alpha-angle method. At baseline, sympathetic nerve activity was significantly elevated in COPD patients and baroreflex sensitivity was decreased (5.0+/-0.6 versus 8.9+/-0.8 ms.mmHg(-1)). Breathing at a rate of 6 breaths.min(-1) caused sympathetic activity to drop significantly in COPD patients (from 61.3+/-4.6 to 53.0+/-4.3 bursts per 100 heartbeats) but not in control subjects (39.2+/-3.2 versus 37.5+/-3.3 bursts per 100 heartbeats). In both groups, slow breathing significantly enhanced baroreflex sensitivity. In conclusion, sympathovagal imbalance is present in normoxic chronic obstructive pulmonary disease patients. The possibility of modifying these changes by slow breathing may help to better understand and influence this systemic disease.

Automated software supported versus manual aorto-iliac diameter measurements in CT angiography of patients with abdominal aortic aneurysms: Assessment of inter- and intraobserver variation

Background: Open surgical or endovascular abdominal aortic aneurysm (AAA) relies on precise preprocedual imaging. Purpose of this study was to assess inter- and intraobserver variation of software-supported automated and manual multi row detector CT angiography (MDCTA) in aortoiliac diameter measurements before AAA repair. Patients and methods: Thirty original MDCTA data sets (4 times 2mm collimation) of patients scheduled for endovascular AAA repair were studied on a dedicated software capable of creating two-dimensional reformatted planes orthogonal to the aortoiliac center-line. Measurements were performed twice with a four-week interval between readings. Data were analysed by two blinded readers at random order. Two different measurement methods were performed: reader-assisted freehand wall-to-wall measurement and semi-automatic measurement. Results: Aortoiliac diameters were significantly underestimated by the semi-automatic method as compared to reader-assisted measurements (p < 0.0031). Intraobserver variability of AAA diameter calculation was not significant (p > 0.15) for reader-assisted measurements except for the diameter of the left common iliac artery in reader 2 (p = 0.0045) and it was not significant (p > 0.14) using the semi-automatic method. Interobserver variability was not significant for AAA diameter measurements using the reader-assisted method and for proximal neck analysis with the semi-automatic method (p > 0.27). Relevant interobserver variation was observed for semi-automatic measurement of maximum AAA (p = 0.0007) and iliac artery diameters (p = 0.024). Conclusions: Dedicated MDCTA software provides a useful tool to minimize aortoiliac diameter measurement variation and to improve imaging precision before AAA repair. For reliable AAA diameter analysis the reader-assisted freehand measurement method is recommended to be applied to a set of reformatted CT data as provided by the software used in this study.

Diagnosenverschlüsselung durch Medizinische Dokumentationsassistentin oder Stationsarzt

BACKGROUND AND OBJECTIVE

Starting in 2004 the patient budget in Germany will be calculated according to the Diagnosis Related Group (DRG) system, by which system the monetary reward of a unit will be directly related to the quality of documentation e. g. diagnosis and procedures. The aim of this study was to compare the quality of documentation by a medical documentation assistant (MDA) with the usual practice of documentation by the ward physician (WP). Additionally, the effect of introducing a completely changed organizational process was tested.

METHODS

In a prospective study on the ward of a gastroenterology unit two different approaches of medical documentation were compared. In a first six-month period diagnosis and procedures were encoded by WP. In the following six months an MDA was introduced and involved in the encoding process.

RESULTS

In the first six months 221 patients (mean age 55 +/- 16,2 years, 55,7 % males) were evaluated, whereas in the following six months 305 patients (mean age 53 +/- 15,4 years, 59,9 % males) were included. The introduction of an MDA improved medical documentation and economical reference numbers: with an increase of diagnosis per case to 7,43 (in first six months 5,53), patient complexity and comorbidity level (PCCL) to 2,5 (in first six months 2,13), case-mix index to 1,04 (in first six months 0,98). Additionally the medial hospitalization time decreased from 11,2 to 8,1 days. The average daily reimbursement increased in the MDA group from 423 Euro to 603 Euro. This was calculated on the basis of a basic case factor of 2900 Euro.

CONCLUSION

Introduction of an MDA in a gastroenterology ward increases the quality of documentation and results in an improved presentation of DRG-relevant efforts with a better reimbursement of medical costs.

Pulmonary gas distribution during ventilation with different inspiratory flow patterns in experimental lung injury -- a computed tomography study

BACKGROUND

There is still controversy about the optimal inspiratory flow pattern for ventilation of patients with acute lung injury. The aim of this study was to compare the effects of pressure-controlled ventilation (PCV) with a decelerating inspiratory flow with volume-controlled ventilation (VCV) with constant inspiratory flow on pulmonary gas distribution (PGD) in experimentally induced ARDS.

METHODS

Sixteen adult sheep were randomized to be ventilated with PCV or VCV after surfactant depletion by repeated bronchoalveolar lavage. Positive end-expiratory pressure (PEEP) was increased in a stepwise manner from zero end-expiratory pressure (ZEEP) to 7, 14 and 21 cm H(2)O in hourly intervals. Respiratory rate, inspiration-to-expiration ratio and tidal volume were kept constant. Central hemodynamics, gas exchange and airway pressures were measured. Electron beam computed tomographic (EBCT) scans of the entire lungs were performed at baseline (preinjury) and each level of end-expiratory pressure during an inspiratory and expiratory hold maneuver. The lungs were three-dimensionally reconstructed and volumetric assessments were made separating the lungs into four subvolumes classified as overinflated, normally aerated, poorly aerated and nonaerated.

RESULTS

Pressure-controlled ventilation led to a decrease in peak airway pressure and an increase in mean airway pressure. No differences between groups were found regarding plateau pressures, hemodynamics and gas exchange. Recruitment, defined as a decrease in expiratory lung volume classified as nonaerated, was similar in both groups and predominantly associated with PEEP. Overinflated lung volumes were increased with PCV.

CONCLUSIONS

In this model of acute lung injury, ventilation with decelerating inspiratory flow had no beneficial effects on PGD when compared with ventilation with constant inspiratory flow, while the increase in overinflated lung volumes may raise concerns regarding potential ventilator-associated lung injury.

Effects of end-inspiratory and end-expiratory pressures on alveolar recruitment and derecruitment in saline-washout-induced lung injury -- a computed tomography study

BACKGROUND

Lung protective ventilation using low end-inspiratory pressures and tidal volumes (VT) has been shown to impair alveolar recruitment and to promote derecruitment in acute lung injury. The aim of the present study was to compare the effects of two different end-inspiratory pressure levels on alveolar recruitment, alveolar derecruitment and potential overdistention at incremental levels of positive end-expiratory pressure.

METHODS

Sixteen adult sheep were randomized to be ventilated with a peak inspiratory pressure of either 35 cm H2O (P35, low VT) or 45 cm H2O (P45, high VT) after saline washout-induced lung injury. Positive end-expiratory pressure (PEEP) was increased in a stepwise manner from zero (ZEEP) to 7, 14 and 21 cm of H2O in hourly intervals. Tidal volume, initially set to 12 ml kg(-1), was reduced according to the pressure limits. Computed tomographic scans during end-expiratory and end-inspiratory hold were performed along with hemodynamic and respiratory measurements at each level of PEEP.

RESULTS

Tidal volumes for the two groups (P35/P45) were: 7.7 +/- 0.9/11.2 +/- 1.3 ml kg(-1) (ZEEP), 7.9 +/- 2.1/11.3 +/- 1.3 ml kg(-1) (PEEP 7 cm H2O), 8.3 +/- 2.5/11.6 +/- 1.4 ml kg(-1) (PEEP 14 cm H2O) and 6.5 +/- 1.7/11.0 +/- 1.6 ml kg(-1) (PEEP 21 cm H2O); P < 0.001 for differences between the two groups. Absolute nonaerated lung volumes during end-expiration and end-inspiration showed no difference between the two groups for given levels of PEEP, while tidal-induced changes in nonaerated lung volume (termed cyclic alveolar instability, CAI) were larger in the P45 group at low levels of PEEP. The decrease in nonaerated lung volume was significant for PEEP 14 and 21 cm H2O in both groups compared with ZEEP (P < 0.005). Over-inflated lung volumes, although small, were significantly higher in the P45 group. Significant respiratory acidosis was noted in the P35 group despite increases in the respiratory rate.

CONCLUSION

Limiting peak inspiratory pressure and VT does not impair alveolar recruitment or promote derecruitment when using sufficient levels of PEEP.

Copper bioavailability and extractability as related to chemical properties of contaminated soils from a vine-growing area

Vineyard soils have been contaminated by Cu as a consequence of the long-term use of Cu salts as fungicides against mildew. This work aimed at identifying which soil parameters were the best related to Cu bioavailability, as assessed by measuring the concentrations of Cu in shoots and roots of tomato cropped (in lab conditions) over a range of 29 (24 calcareous and five acidic) Cu-contaminated topsoils from a vine-growing area (22-398 mg Cu kg(-1)). Copper concentrations in tomato shoots remained in the adequate range and were independent of soil properties and soil Cu content. Conversely, strong, positive correlations were found between root Cu concentration, total soil Cu, EDTA- or K-pyrophosphate-extractable Cu and organic C contents in the 24 calcareous soils, suggesting a prominent role of organic matter in the retention and bioavailability of Cu. Such relations were not observed when including the five acidic soils in the investigated population, suggesting a major pH effect. Root Cu concentration appeared as a much more sensitive indicator of soil Cu bioavailability than shoot Cu concentration. Simple extractions routinely used in soil testing procedures (total and EDTA-extractable Cu) were adequate indicators of Cu bioavailability for the investigated calcareous soils, but not when different soil types were considered (e.g. acidic versus calcareous soils).

[High frequency oscillatory ventilation as therapy for acute lung injury and ARDS]

Mechanical ventilation is the mainstay of therapy for acute lung injury, a disease with remainingly high morbidity and mortality. As a result of an improved understanding that mechanical ventilation itself can contribute to and aggravate the disease process, the term ventilator-associated lung injury (VALI) has been introduced. Main risk factor for VALI are (1) alveolar overdistention caused by excessivly high tidal volumes and/or inspiratory pressures (volu-/barotrauma), as well as (2) cyclic alveolar collapse promoted by insufficient endexpiratory pressure. So called "lung-protective ventilatory strategies" aim at minimizing these risk factors by the use of small tidal volumes and high PEEP levels. High frequency oscillatory ventilation (HFOV) can be regarded as an ultimate form of this approach, combining minimal pressure changes with a high continuous distending pressure (CDP). That CDP is generated using high fresh gas flows ("Super-CPAP"), while a piston pump incorporated into the system creates an oscillatory flow at frequencies ranging from 3-7 Hz. An initial lung volume recruitment manoeuvre is mandatory for the optimal use of HFOV. Whereas for many years HFOV is a well established therapy for the infant respiratory distress syndrome, experience in adults is still rare. First results, however, look promising, and HFOV might as well turn out as a valuable treatment modalitiy for ARDS.