A Strategic Core Role Perspective on Team Coordination: Benefits of Centralized Leadership for Managing Task Complexity in the Operating Room

OBJECTIVE

We examine whether surgical teams can handle changes in task requirements better when their formal leader and strategic core role holder-that is, the main surgeon-is central to team coordination.

BACKGROUND

Evidence regarding the benefits of shared leadership for managing complex tasks is divided. We tested whether a strategic core role holder's centrality in team coordination helps teams to handle different types of task complexity.

METHOD

We observed coordination as specific leadership behavior in 30 surgical teams during real-life operations. To assess the strategic core role holder's coordination centrality, we conducted social network analyses. Task complexity (i.e., surgical difficulty and unexpected events) and surgical goal attainment were rated in a questionnaire.

RESULTS

In the critical operation phase, surgical difficulty impaired goal attainment when the strategic core role holder's coordination centrality was low, while this effect was nonsignificant when his/her coordination centrality was high. Unexpected events had a negative effect on surgical goal attainment. However, coordination centrality of the strategic core role holder could not help manage unexpected events.

CONCLUSION

The results indicate that shared leadership is not beneficial when teams face surgical difficulty during the critical operation phase. In this situation, team coordination should rather be centralized around the strategic core role holder. Contrarily, when unexpected events occur, centralizing team coordination around a single leader does not seem to be beneficial for goal attainment.

APPLICATION

Leaders and team members should be aware of the importance of distributing leadership differently when it comes to managing different types of task complexity.

Patient Evaluation of the 7X30 Beecher Mirage Low Vision System

The authors mailed a questionnaire to 133 patients who received 7X30 Beecher Mirage Binoculars. The patients responded to questions about frequency of use, cosmetic appearance, comfort, activities for which the device was used, need for repairs, and the case of independently adjusting the device. Results indicated that 75 percent of respondents used the device weekly or more frequently. Television viewing; distant reading activities; and watching people, wildlife, and neighborhood activities were the most frequently reported uses for this device. Visual acuity, comfort of the nosepiece, and the patient's ability to independently adjust the device were significant factors affecting the respondents’ use of the binoculars.

Autologous lipotransfer for bone defects secondary to osteomyelitis: A report of a novel method and systematic review of the literature

Autologous bone grafting is the gold standard in patients with bone defects but is associated with significant pain and donor site morbidity. Autologous lipotransfer (fat grafting or lipofilling) has become very popular in the therapy of chronic wounds. Mesenchymal stem cells from adipose tissue are known for their regenerative, reparative, and immunomodulatory effects. This case study and review evaluates the use of autologous lipotransfer for chronic osteomyelitis in a 26-year-old patient. A 26-year-old female suffering from chronic tibial osteomyelitis was initially treated with surgical debridement and antibiotics followed by lipoharvest and autologous lipofilling. MRI and computed tomography scans were performed at 2 and 6 weeks and 6 months postoperatively. A formal systematic review of clinical trials investigating autologous lipotransfer for osteomyelitis was conducted. The patient remained asymptomatic without recurrence, and the bone defect cavity showed vascularised adipose tissue after 6 weeks, with early signs of osteogenesis. The highest foot and ankle disability index was 100. The systematic review identified 266 studies after duplicates were removed. After screening for eligibility, seven manuscripts were further assessed, with none meeting the inclusion criteria. This is the first study to report the successful use of autologous lipotransfer with early signs of osteogenesis in a patient suffering from chronic osteomyelitis. Autologous lipotransfer is relatively simple, safe, and minimally invasive, making it a potential alternative to current treatments. Further research is required to assess the safety, feasibility, and efficacy of autologous fat grafting and the mechanism of osteogenesis.

Occurrence of Occult Malignancies in Reduction Mammoplasties

Objectives

Patients undergoing reduction mammoplasty (RM) bear the risk of having occult breast cancer nests. The detection rate of malignant neoplasms in the resected specimens, varies greatly in the literature. The aim of our present study was to analyze risk factors and evaluate histopathological findings in our cohort of patients who underwent RM towards our center.

Material and methods

In this retrospective single center study we analyzed 559 female patients [median age 35.99 (±13.34)] who underwent RM between 2000 and 2010. The presence of carcinoma and ductal- (DCIS) or lobular carcinoma in situ (LCIS) were considered as pathological findings. Body mass index (BMI), age, surgical technique and mass of resected tissue were included into the analysis.

Results

There were 6 cases of occult neoplasia (1.08 %) including 2 cases of breast cancer, one multicentric DCIS and 3 cases of LCIS (0.54 %) in 559 patients. Patients with breast cancer showed a significant increased median age: 49y median (IQR ± 18) vs. 35y (IQR ± 21) (p = 0.004) and a trend towards increased BMI: 25.88 median (IQR ± 7.3) vs. 24.50 (IQR ± 4.09) (p = 0.219), compared to patients without pathological results. One patient with occult carcinoma had a negative preoperative mammography, a patient with LCIS a negative preoperative breast ultrasound.

Conclusions

In our study the occurrence of occult neoplasia was associated with increased age and showed a trend towards increased BMI when compared to patients without pathological findings. The study demonstrates the necessity of thorough medical history, preoperative diagnostic screening and histopathological analysis of all resected specimens.

Nikolaus Rüdinger (1832-1896), His Description of Joint Innervation in 1857, and the History of Surgical Joint Denervation

BACKGROUND

 Selective joint denervation has become a reliable palliative treatment, especially for painful joints in the upper and lower extremity.

METHODS

 This article highlights the life and work of Nikolaus Rüdinger (1832-1896) who first described joint innervation which became the basis of later techniques of surgical joint denervation. The historical evolution of this method is outlined.

RESULTS

 Rüdinger made a unique career from apprentice barber to military surgeon and anatomy professor in Munich, Germany. His first description of articular innervation of temporomandibular, shoulder, elbow, wrist, finger, sacroiliac, hip, knee, ankle, foot, and toe joints in 1857 stimulated the subsequent history of surgical joint denervation. Comparing his investigations with modern joint denervation methods, developed by pioneers like Albrecht Wilhelm or A. Lee Dellon, shows his great exactitude and anatomical correspondence despite different current terminology. Clinical series of modern surgical joint denervations reveal success rates of up to 80% with reliable long-term results.

CONCLUSION

 The history of joint denervation with Rüdinger as its important protagonist offers inspiring insights into the evolution of surgical techniques and exemplifies the value of descriptive functional anatomy, even if surgical application may not have been realized until a century later.

Dupuytren Disease: Is There Enough Comprehensive Patient Information on the Internet?

Background

Dupuytren disease is a chronic nonmalign fibroproliferative disorder that causes finger contractures via proliferation of new tissue under the glabrous skin of the hand, resulting in multiple functional limitations for the patient. As many surgical therapy options exist, patients suffering from this condition actively search for information in their environment before consulting a health professional.

Objective

As little is known about the quality of Web-based patient information, the aim of this study was to conduct its systematic evaluation using a validated tool.

Methods

A total of 118 websites were included, and qualitative and quantitative assessment was performed using the modified Ensuring Quality Information for Patients (EQIP) tool. This standardized and reproducible tool consists of 36 items to assess available information in three categories: contents, identification, and structure data. Scientific data with restricted access, duplicates, and irrelevant websites were not included.

Results

Only 32 websites addressed more than 19 items, and the scores did not significantly differ among the website developers. The median number of items from the EQIP tool was 16, with the top websites addressing 28 out of 36 items. The quality of the newly developed websites did not increase with passing time.

Conclusions

This study revealed several shortcomings in the quality of Web-based information available for patients suffering from Dupuytren disease. In the world of continuously growing and instantly available Web-based information, it is the health providers’ negligence of the last two decades that there are very few good quality, informative, and educative websites that could be recommended to patients.

Microbiological findings in burn patients treated in a general versus a designated intensive care unit: Effect on length of stay

BACKGROUND

Infection is one of the most common causes of mortality and morbidity in burn patients. The incidence and frequency of microbiological micro-organisms are known to vary across different models of intensive care units. To date, no study has attempted to describe the different findings in burn patients treated in an open, general intensive care unit (GICU) versus a dedicated burns intensive care unit (BICU). Only limited data is available on the effect of these microbiological micro-organisms on patients' length of stay.

AIM

To characterize and compare the microbiological flora and antibiotic resistance patterns encountered in two different models of burn intensive care and to determine the effect of specific microbiological types on length of intensive care unit (ICU) and overall stay.

METHODS

A retrospective case-control study of 209 burn patients treated in two highly specialized, Western burn referral centres between September 2009 and March 2014.

RESULTS

9710 culture results were analysed, of which 2590 (26.7%) yielded positive results (1537 in the GICU and 1050 in the BICU). Gram-positive cultures were more frequently found in the GICU, whereas Gram-negative and yeast cultures were more prevalent in the BICU. The most frequently encountered micro-organisms in both units were similar and included Staphylococcus aureus, Pseudomonas aeruginosa, coagulase-negative staphylococci (CoNS) and Candida albicans. Significantly more resistant bacteria were detected in the BICU. Testing positive across all types of microbiological isolates, as well as for both Gram-positive and -negative bacteria significantly prolonged patient length of stay. This effect was even more pronounced if the micro-organisms were resistant to antimicrobial therapy.

CONCLUSION

There are notable differences in the microbiological isolate and antibiotic resistance patterns between burn patients treated in a GICU compared to a designated BICU. In both units, testing positive for resistant microbiological micro-organisms is significantly associated with longer hospital stay.

Adaptive coordination in surgical teams: an interview study

Background

Effective teamwork has been recognised as a major contributor to safe patient care in surgery. Previous research has highlighted the importance of adaptive coordination for effective performance in acute care settings. Expanding this line of research this study explores the coordination behaviours and adaptive coordination strategies employed by surgical teams and identifies relevant situational characteristics influencing those coordination processes.

Method

We conducted a qualitative content analysis of semi-structured interviews with 33 surgical team members (nurses and physicians) from different specialties and hospitals.

Results

We identified coordination behaviours (i.e. task management, information management, teaching and leadership) and adaptive coordination strategies triggered by varying requirements due to non-routine events, intraoperative complications and differing level of experience among operating room staff. Interviewees highlighted the importance of effectively managing challenging moments and the supporting effect of positive climate on teamwork.

Conclusions

This study complements previous research on the non-technical skills underpinning safe performance in surgical teams. It highlights the central role of coordination and points out the ways in which situational variability requires the team to behave adaptively.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-015-0792-5) contains supplementary material, which is available to authorized users.

Major burn injuries associated with Christmas celebrations: a 41-year experience from Switzerland

In Switzerland it is customary to light candles on Christmas trees and advent wreaths. This tradition leads to an increased risk of home fires. We reviewed the records of patients who sustained burn injuries from a lit Christmas tree or advent wreath during the Christmas holidays between January 1971 and January 2012. We treated 28 patients and observed 4 fatalities (mortality rate: 14%). 61% of the patients were male, 39% were female. The mean abbreviated burn severity index (ABSI) was 6.5 points in the group of the survivors and 10.8 points in the group of the non-survivors. The mean total body surface area burned (TBSA) for survivors was 18.9%, with 14.1% having full thickness burns; for the non-survivors the mean TBSA was 45.2%, with 38% having full thickness burns. The Mann-Whitney U-test showed a significant difference between the survivors and the fatalities concerning the mean total and full thickness burned body surface area (p value 0.009 and 0.012). More than sixty percent of the fires occurred in January and the most severe accidents were seen after January 4th. Despite Christmas decoration-associated fires being relatively uncommon, they tend to cause more serious injuries than regular household fires. We recommend that in countries where it is customary to set up flammable Christmas decorations, state-issued information pamphlets with instructions on fire safety conduct should be distributed.

Otfrid Foerster (1873-1941)--self-taught neurosurgeon and innovator of reconstructive peripheral nerve surgery

Otfrid Foerster (1873-1941) became a self-taught neurosurgeon during and after WW I, playing a critical role in the development of peripheral nerve reconstruction. Although best known for describing dermatomes, he published over 300 articles on the nervous system. Confronted by thousands of nerve injuries during WW I, as well as poor results and disinterest from his surgical colleagues, Foerster began performing neurolysis and tension-free nerve repairs himself under emergency conditions. He pioneered grafting motor nerve defects by expendable cutaneous nerves (e.g., sural) and performed intraplexal neurotizations and various nerve transfers, such as the pectoral, subscapular, long thoracic, and thoracodorsal nerves in brachial plexus injuries. Foerster championed rehabilitation, recognizing the potential of electrostimulation and physiotherapy to influence cortical reorganization (brain plasticity) and improve recovery after nerve injury. Foerster died from tuberculosis in 1941, leaving a rich reconstructive peripheral nerve legacy; his innovative and visionary spirit serves as a role model.

Updated Swiss guidelines for the treatment and follow-up of cutaneous melanoma

Melanoma is the most common lethal cutaneous neoplasm. In order to harmonise treatment and follow-up of melanoma patients, guidelines for the management of melanoma in Switzerland were inaugurated in 2001 and revised in 2006. A new classification and recent results in randomised trials necessitated changes concerning staging and modifications of the recommendations of therapy and follow-up.

[The role of surgery in the treatment of cutaneous melanoma]

Historically, melanoma patients were subject to wide local excisions and elective lymph node dissections. Both approaches were the focus of intense scrutiny in the past three decades, and many surgical dogmas were abolished. The role of surgery in providing local control over the primary tumor is largely undisputed. In addition, the surgical management strategies of the regional lymph nodes have undergone considerable change in the past; with lymphatic mapping and sentinel lymph node identification being the most relevant contribution, allowing selection of patients for adjuvant treatment (completion lymph node dissection, Interferon therapy). Surgery has also a place in palliative treatment of isolated systemic metastases for selected cases with good performance status in Stage IV melanoma.

[Reconstruction of isolated axillary nerve lesions: clinical and electrophysiological long-term results]

PURPOSE

The purpose of this retrospective study was the clinical and electrophysiological assessment of long-term results following surgical treatment of isolated axillary nerve lesions.

PATIENTS AND METHOD

10 patients, who underwent axillary nerve reconstruction using a nerve graft (80%) or a neurolysis alone (20%), with a follow-up period of 6.7 years (1.6-10.8 years) on average, were included in the study. In addition to the clinical examination, we examined reinnervation by electrophysiological methods and analysed their correlation to clinical results.

RESULTS

30% of the patients had muscle strength of M5 and full active range of motion of 180°, 40% reached M4 and averaged 170° (80-180°), 30% of the patients M3 and 65° (40-90°). In patients with M5, muscle compound action potential averaged 40% of the contralateral side (21-62%), in patients with M4 36% (29-58%), and in patients with M3 7% (3-11%). Good results were associated with younger patient age, a short delay prior to the operation and neurolysis alone (indicated by intraoperative electroneurography).

CONCLUSION

The good results confirm our treatment algorithm for isolated axillary nerve lesions by neurolysis alone or reconstruction with autologous nerve transplantation. Measurement of compound muscle action potential is a valuable addition to difficult clinical assessment, as its amplitude enables quantification of axillary nerve recovery.

Spider silk constructs enhance axonal regeneration and remyelination in long nerve defects in sheep

BACKGROUND

Surgical reapposition of peripheral nerve results in some axonal regeneration and functional recovery, but the clinical outcome in long distance nerve defects is disappointing and research continues to utilize further interventional approaches to optimize functional recovery. We describe the use of nerve constructs consisting of decellularized vein grafts filled with spider silk fibers as a guiding material to bridge a 6.0 cm tibial nerve defect in adult sheep.

METHODOLOGY/PRINCIPAL FINDINGS

The nerve constructs were compared to autologous nerve grafts. Regeneration was evaluated for clinical, electrophysiological and histological outcome. Electrophysiological recordings were obtained at 6 months and 10 months post surgery in each group. Ten months later, the nerves were removed and prepared for immunostaining, electrophysiological and electron microscopy. Immunostaining for sodium channel (NaV 1.6) was used to define nodes of Ranvier on regenerated axons in combination with anti-S100 and neurofilament. Anti-S100 was used to identify Schwann cells. Axons regenerated through the constructs and were myelinated indicating migration of Schwann cells into the constructs. Nodes of Ranvier between myelin segments were observed and identified by intense sodium channel (NaV 1.6) staining on the regenerated axons. There was no significant difference in electrophysiological results between control autologous experimental and construct implantation indicating that our construct are an effective alternative to autologous nerve transplantation.

CONCLUSIONS/SIGNIFICANCE

This study demonstrates that spider silk enhances Schwann cell migration, axonal regrowth and remyelination including electrophysiological recovery in a long-distance peripheral nerve gap model resulting in functional recovery. This improvement in nerve regeneration could have significant clinical implications for reconstructive nerve surgery.

Local burn versus local cold induced acute effects on in vivo microcirculation and histomorphology of the human skin

BACKGROUND

The impact of burns and colds on human skin microcirculation and histomorphology has not been compared as yet. Reflectance confocal microscopy (RCM) enables in vivo insight in human skin on cellular and subcellular levels. We evaluated analogies and differences of thermal injuries on microcirculation and histomorphology in vivo using RCM.

METHODS

Local superficial burn (6 female, 4 male; aged 28.4 ± 2.9 years, burn group) versus superficial cold (4 female, 6 male; aged 30.4 ± 5.2 years, cold group) was induced on the dorsum of the hand in an experimental immersion hand model. In vivo RCM was performed prior (control), immediately (t1) and 15 minutes (t2) following thermal injury to evaluate: Individual blood cell flow (IBCF), functional capillary density (FCD), epidermal thickness (ET), and granular cell size (GCS).

RESULTS

In the burn group, IBCF was increased at t1 (78.02 ± 2.60/min) and remained elevated at t2 (84.16 ± 3.04/min). In the cold group, IBCF decreased at t1 (12.62 ± 2.12 min) and increased at t2 (74.24 ± 3.14/min, P < 0.05) compared to the controls (58.23 ± 3.21/min). FCD was 6.74 ± 0.52/mm(2) in controls and increased at both t1 (7.82 ± 0.72/mm(2)) and t2 (8.02 ± 0.81/mm(2)) in the burn group. In the cold group, FCD decreased at t1 (2.60 ± 0.42/mm(2)) and increased at t2 (7.92 ± 0.44/mm(2), P < 0.05). ET increased at both t1 (43.12 ± 4.08 μm, P > 0.05) and t2 (47.26 ± 4.72 μm, P < 0.05) in the burn group. In the cold group, ET decreased at t1 (39.92 ± 3.14 μm, P > 0.05) and increased at t2 (44.72 ± 4.06 μm, P < 0.05) compared to the controls (41.26 ± 3.82 μm). Control GCS was 726.9 ± 59.4 μm(2) and increased at both t1 (739.8 ± 69.8 μm(2), P > 0.05) and t2 (762.6 ± 71.4 μm(2), P < 0.05) in the burn group. In the cold group, GCS decreased at t1 (712.4 ± 53.8 μm(2), P > 0.05) and increased at t2 (742.6 ± 64.8 μm(2), P < 0.05).

CONCLUSIONS

Superficial burn induces more cellular destruction and cold leads to huge fluctuation in tissue perfusion, however, with moderate impact on histomorphology. The effect on dermal capillaries suggests a selective neural control and cold injuries might down-regulate this system, much more than burns can activate it.

Interactions between spider silk and cells--NIH/3T3 fibroblasts seeded on miniature weaving frames

Background

Several materials have been used for tissue engineering purposes, since the ideal matrix depends on the desired tissue. Silk biomaterials have come to focus due to their great mechanical properties. As untreated silkworm silk has been found to be quite immunogenic, an alternative could be spider silk. Not only does it own unique mechanical properties, its biocompatibility has been shown already in vivo. In our study, we used native spider dragline silk which is known as the strongest fibre in nature.

Methodology/Principal Findings

Steel frames were originally designed and manufactured and woven with spider silk, harvesting dragline silk directly out of the animal. After sterilization, scaffolds were seeded with fibroblasts to analyse cell proliferation and adhesion. Analysis of cell morphology and actin filament alignment clearly revealed adherence. Proliferation was measured by cell count as well as determination of relative fluorescence each after 1, 2, 3, and 5 days. Cell counts for native spider silk were also compared with those for trypsin-digested spider silk. Spider silk specimens displayed less proliferation than collagen- and fibronectin-coated cover slips, enzymatic treatment reduced adhesion and proliferation rates tendentially though not significantly. Nevertheless, proliferation could be proven with high significance (p<0.01).

Conclusion/Significance

Native spider silk does not require any modification to its application as a biomaterial that can rival any artificial material in terms of cell growth promoting properties. We could show adhesion mechanics on intracellular level. Additionally, proliferation kinetics were higher than in enzymatically digested controls, indicating that spider silk does not require modification. Recent findings concerning reduction of cell proliferation after exposure could not be met. As biotechnological production of the hierarchical composition of native spider silk fibres is still a challenge, our study has a pioneer role in researching cellular mechanics on native spider silk fibres.

Early fluid resuscitation with hyperoncotic hydroxyethyl starch 200/0.5 (10%) in severe burn injury

Introduction

Despite large experience in the management of severe burn injury, there are still controversies regarding the best type of fluid resuscitation, especially during the first 24 hours after the trauma. Therefore, our study addressed the question whether hyperoncotic hydroxyethyl starch (HES) 200/0.5 (10%) administered in combination with crystalloids within the first 24 hours after injury is as effective as 'crystalloids only' in severe burn injury patients.

Methods

30 consecutive patients were enrolled to this prospective interventional open label study and assigned either to a traditional 'crystalloids only' or to a 'HES 200/0.5 (10%)' volume resuscitation protocol. Total amount of fluid administration, complications such as pulmonary failure, abdominal compartment syndrome, sepsis, renal failure and overall mortality were assessed. Cox proportional hazard regression analysis was performed for binary outcomes and adjustment for potential confounders was done in the multivariate regression models. For continuous outcome parameters multiple linear regression analysis was used.

Results

Group differences between patients receiving crystalloids only or HES 200/0.5 (10%) were not statistically significant. However, a large effect towards increased overall mortality (adjusted hazard ratio 7.12; P = 0.16) in the HES 200/0.5 (10%) group as compared to the crystalloids only group (43.8% versus 14.3%) was present. Similarly, the incidence of renal failure was 25.0% in the HES 200/0.5 (10%) group versus 7.1% in the crystalloid only group (adjusted hazard ratio 6.16; P = 0.42).

Conclusions

This small study indicates that the application of hyperoncotic HES 200/0.5 (10%) within the first 24 hours after severe burn injury may be associated with fatal outcome and should therefore be used with caution.

Trial registration

NCT01120730.

Assessment of microcirculatory influence on cellular morphology in human burn wound healing using reflectance-mode-confocal microscopy

Previous studies have assessed the effects of changes in microcirculation on wound healing; however, the influence of microcirculation on tissue histomorphology remains widely unknown. Reflectance-mode-confocal microscopy (RMCM) enables in vivo tissue observation on a cellular level. We present RMCM data evaluating the local microcirculation and assess the influence on histomorphology during burn healing. RMCM was performed in 12 patients (aged; 36.2+/-14.2 years, maximum-burn-extent: 4% total body surface area) at times 12, 36, and 72 hours after a superficial burn. The following parameters were assessed: quantitative blood-cell-flow (cbf), epidermal thickness (Emin), basal-layer thickness (tbl), and granular cell-size (Agran). Cbf was found to be 54+/-3.6 cells/minutes (control), increased to 91+/-3.6 cells/minutes (p<0.05) 12 hours postburn; decreased to 71+/-6.1 cells/minutes (p<0.05) (36 hours), and to 63+/-2.3 cells/minutes (p>0.05) 72 hours postburn. Emin was 43.74+/-3.87 mum (control), increased to 51.67+/-4.04 mum (p<0.05) 12 hours, decreased to 48.67+/-3.51 mum (p<0.05) 36 hours, and to 45.33+/-3.21 mum (p>0.05) at 72 hours postburn. Tbl was 14.17+/-0.6 mum (control), increased to 16.93+/-1.15 mum (p<0.05) 12 hours, decreased to 15.93+/-1.20 mum (p<0.05) 32 hours, and to 15.00+/-0.85 mum (p>0.05) 72 hours postburn. Agran was 718+/-56.20 mum(2) (control), increased to 901+/-66.02 mum(2) (p<0.05) 12 hours, decreased to 826+/-56.86 mum(2) 36 hours, and 766+/-65.06 mum(2) at 72 hours postburn. RMCM enables in vivo observation of wound microcirculation and allows direct assessment of vascular effects on cutaneous histomorphology during the healing course of superficial burns.

[Fibrolipohamartoma of the upper extremity: treatment results in six patients over nine years]

BACKGROUND

Fibrolipohamartoma (FLH) is a rare, benign congenital malformation of peripheral nerves, mainly the median nerve, less frequently of the ulnar or other nerves. Early symptom is an initially painless, slowly growing and circumscript swelling. Affections at the wrist level or the foot are occasionally accompanied by macrodactyly. Although FLH is a congenital disorder, because of absent or discreet symptoms, the diagnosis is often made in early adulthood only due to a compression neuropathy. Magnetic resonance image findings are pathognomonic, biopsies are not necessary. In the medical literature, FLH has been described for the past forty years only by means of case reports or small case series. Meanwhile, surgical decompression is considered as therapeutic gold standard, in case of an accompanying macrodactyly in combination with corrective procedures for length, breadth and axis.

AIM OF THE STUDY

To study long term results after surgical compression of FLH und thus an assessment of this therapeutical concept generally accepted as gold standard in this rare entity.

PATIENTS AND METHODS

Between 1994 and 2004 we treated 9 patients (8 women, 1 man) with 11 tumors, average age was 38 years (3-62). 2 of the 9 patients had macrodactyly. In 7 patients, the median nerve was affected, in one patient bilaterally, in 5 patients the ulnar nerve, and in one patient both ipsilateral median and ulnar nerves. Of those 9 patients, we were able to follow up 6 clinically and electroneurographically. In addition, the DASH-score was collected. Average follow-up after initial decompression was 9 years (2-23). We performed surgical decompression in 5 patients, one patient was treated conservatively.

RESULTS

Patients with affections of the median nerve showed tendentially better results after surgical decompression compared to those with FLH of the ulnar nerve, irrespective of the affected anatomical level. Surgical decompression led to a relief of the symptoms in all patients; an improvement of motor function, hypaesthesia and cold sensitivity, however, could not be demonstrated.

CONCLUSION

FLH must be considered in the differential diagnosis of macrodactyly. We recommend surgical decompression, as it leads to relief of the symptoms. It does, however, not have a beneficial effect on already present motor impairments, sensory deficits and cold sensitivity. We strictly advise against tumor resection.

Insight in human skin microcirculation using in vivo reflectance-mode confocal laser scanning microscopy

Reflectance-mode confocal laser scanning microscopy allows in vivo imaging of the human skin. We hypothesized that this high-resolution technique enables observation of dynamic changes of the cutaneous microcirculation. Twenty-two volunteers were randomly divided in two groups. Group 1 was exposed to local heating and group 2 to local cold stress. Confocal microscopy was performed prior t (0) (control), directly t (1) and 5 min t (2) after local temperature changes to evaluate quantitative blood cell flow, capillary loop diameter, and density of dermal capillaries. In group 1, blood flow increased at t (1) (75.82 +/- 2.86/min) and further at t (2) (84.09 +/- 3.39/min) compared to the control (61.09 +/- 3.21/min). The control capillary size was 9.59 +/- 0.25 microm, increased to 11.16 +/- 0.21 microm (t (1)) and 11.57 +/- 0.24 microm (t (2)). The dermal capillary density increased in t (1) (7.26 +/- 0.76/mm(2)) and t (2) (8.16 +/- 0.52/mm(2)), compared to the control (7.04 +/- 0.62/mm(2)). In group 2, blood flow decreased at t (1) (41.73 +/- 2.61/min) and increased at t (2) (83.27 +/- 3.29/min) compared to the control (60.73 +/- 2.90/min). The control capillary size was 9.55 +/- 0.25 microm, decreased at t (1) (7.78 +/- 0.26 microm) and increased at t (2) (11.38 +/- 0.26 microm). Capillary density decreased at t (1) (5.01 +/- 0.49/mm(2)) and increased at t (2) (7.28 +/- 0.53/mm(2)) compared to the control (7.01 +/- 0.52/mm(2)). Confocal microscopy is a sensitive and noninvasive imaging tool for characterizing and quantifying dynamic changes of cutaneous microcirculation on a histomorphological level.

Rapid prototyping of anatomically shaped, tissue-engineered implants for restoring congruent articulating surfaces in small joints

BACKGROUND

Preliminary studies investigated advanced scaffold design and tissue engineering approaches towards restoring congruent articulating surfaces in small joints.

MATERIALS AND METHODS

Anatomical femoral and tibial cartilage constructs, fabricated by three-dimensional fibre deposition (3DF) or compression moulding/particulate leaching (CM), were evaluated in vitro and in vivo in an autologous rabbit model. Effects of scaffold pore architecture on rabbit chondrocyte differentiation and mechanical properties were evaluated following in vitro culture and subcutaneous implantation in nude mice. After femoral and tibial osteotomy and autologous implantation of tissue-engineered constructs in rabbit knee joints, implant fixation and joint articulation were evaluated.

RESULTS

Rapid prototyping of 3DF architectures with 100% interconnecting pores promoted homogeneous distribution of viable cells, glycosaminoglycan (GAG) and collagen type II; significantly greater GAG content and differentiation capacity (GAG/DNA) in vitro compared to CM architectures; and higher mechanical equilibrium modulus and dynamic stiffness (at 0.1 Hz). Six weeks after implantation, femoral and tibial constructs had integrated with rabbit bone and knee flexion/extension and partial load bearing were regained. Histology demonstrated articulating surfaces between femoral and tibial constructs for CM and 3DF architectures; however, repair tissue appeared fibrocartilage-like and did not resemble implanted cartilage.

CONCLUSIONS

Anatomically shaped, tissue-engineered constructs with designed mechanical properties and internal pore architectures may offer alternatives for reconstruction or restoration of congruent articulating surfaces in small joints.

Insight in microcirculation and histomorphology during burn shock treatment using in vivo confocal-laser-scanning microscopy

PURPOSE

Microcirculatory disturbances are well known during shock; however, the accompanied histomorphological alterations are widely unknown. We used high resolution confocal-laser-scanning microscopy for the evaluation of microcirculation and histomorphology during Burn Shock treatment.

METHODS

Confocal-laser-scanning microscopy was performed in 10 burn shock patients (4 women, 6 men; aged 40.6 +/- 11.4 years, burn extent >20% body surface area) initially and 24 hours after shock resuscitation. Ten matched hemodynamic stable burn intensive care unit patients served as controls. The following parameters were evaluated: quantitative blood cell flow, cell size of the granular layer, basal layer thickness, and epidermal thickness.

RESULTS

Quantitative blood cell flow in controls was 62.45 +/- 3.39 cells per minute. Burn shock significantly reduced blood cell flow to 37.27 +/- 3.64 cells per minute; fluid resuscitation effectively restored baseline blood flow (65.18 +/- 3.76 cells per minute) after 24 hours. Granular cell size was 793.61 +/- 41.58 microm(2) in controls vs 644.27 +/- 42.96 microm(2) during burn shock. Post resuscitation granular cell size measured 932.74 +/- 38.83 microm(2). Basal layer thickness was 14.84 +/- 0.59 microm in controls, 13.26 +/- 0.54 microm in burn patients at admission and before resuscitation, and 17.50 +/- 0.46 microm after resuscitation. Epidermal thickness in control patients was 49.60 +/- 2.36 microm, 37.83 +/- 2.47 microm in burn patients at admission and 69.50 +/- 3.18 microm after resuscitation.

CONCLUSIONS

Confocal-laser-scanning microscopy provides a noninvasive tool for simultaneous evaluation of microcirculation and tissue histomorphology. It may help to assess the adequacy of and response to resuscitation of burn patients early after trauma.

Monitoring of microcirculation in free transferred musculocutaneous latissimus dorsi flaps by confocal laser scanning microscopy--a promising non-invasive methodical approach

INTRODUCTION

For the survival of a microvascular tissue transfer, early detection of vascular complications is crucial. In vivo confocal laser scanning microscopy allows real-time, non-invasive evaluation of tissue microcirculation with a high cellular resolution. The aim of this study was to evaluate confocal laser scanning microscopy for early recognition of flap failure.

METHODS

Fourteen patients (ages: 40.2+/-12.4 years) were monitored postoperatively for a period of 24h following free microvascular M. latissimus dorsi transfer to the lower extremity using confocal laser scanning microscopy (Vivascope1500; Rochester; New York; USA). The following parameters were evaluated: quantitative blood-cell flow, diameter of capillary loops and minimal thickness of the epidermis.

RESULTS

Venous congestion was characterised by a decrease in blood-cell flow of up to 41%, accompanied by an increase of the diameter of capillary loops of up to 22% and the minimal thickness of the epidermis up to 32%. By contrast, arterial occlusion was clearly verified by a decrease in blood flow of up to 90%, accompanied by an insignificant change of both capillary loop size and epidermal thickness.

CONCLUSION

Confocal laser scanning microscopy appears to be a useful non-invasive tool for early recognition of flap failure during the monitoring of microsurgical tissue transfer prior to its clinical manifestation.

Factor V Leiden Mutation and Thrombotic Occlusion of Microsurgical Anastomosis After Free TRAM Flap

The transverse rectus abdominis muscle flap is widely used in free microvascular tissue transfer for breast reconstruction following mastectomy. Flap survival may be compromised by failure at the microsurgical anastomosis due to both venous and arterial thrombosis. It is unclear, whether hereditary thrombophilia represents a risk factor for early thrombotic occlusion following free flap procedures. We present a case of a patient with previously diagnosed activated protein resistance caused by heterozygous factor V (position 1691 G→A) Leiden mutation in whom a free transverse rectus abdominis muscle flap was performed. The postoperative course was complicated by repeated thrombosis of both the venous and arterial part of the anastomosis. Immediate thrombectomy and repeated arteriography allowed for partial flap salvage. More data are needed to analyze the impact of hereditary thrombophilia on microvascular anastomosis failure.

[Thermal trauma sustained during epileptic seizures--analysis of 33 cases]

BACKGROUND AND AIMS

Burn injuries are a serious threat to individuals with altered consciousness during epilepsy. The objective of this study detailing 33 individuals who sustained scalds or burn injuries during an epileptic seizure, was to clarify typical injury mechanisms, extent, therapy and sequelae of these injuries and thus identify potential preventive measures to protect this special population from thermal trauma.

RESULTS

Overall, 16 women and 17 men with a mean age of 39.6 (range: 21 - 76) years were included in this retrospective review. The burned body area averaged 16 % (maximum: 51 %), 30 of the 33 patients (91 %) required burn wound excision and skin grafting. The mean ABSI score was 5.5 (range: 3 to 11) points. Thermal trauma mostly occurred as hot water scalds (n = 19) during showering or bathing in a tub (n = 15), followed by falls during cooking or into open fire. None of our patients was informed about the risk of experiencing severe thermal injuries during epileptic seizures. The length of intensive care averaged 33 days (maximum: 79 days), all patients survived. The estimated treatment costs were at least 50,000 Euros per patient.

DISCUSSION

In conclusion, epileptic seizures can cause severe and deep thermal trauma. Our data shows that most of these injuries happen at home and may be easily prevented by simple safety devices, such as water thermo-regulators or the avoidance of high-risk situations, it seems advisable to inform patients with epilepsy and their families and care-givers of this specific danger.

The influence of sentinel lymph node tumour burden on additional lymph node involvement and disease-free survival in cutaneous melanoma--a retrospective analysis of 392 cases

Twenty per cent of sentinel lymph node (SLN)-positive melanoma patients have positive non-SLN lymph nodes in completion lymph node dissection (CLND). We investigated SLN tumour load, non-sentinel positivity and disease-free survival (DFS) to assess whether certain patients could be spared CLND. Sentinel lymph node biopsy was performed on 392 patients between 1999 and 2005. Median observation period was 38.8 months. Sentinel lymph node tumour load did not predict non-SLN positivity: 30.8% of patients with SLN macrometastases (> or =2 mm) and 16.4% with micrometastases (< or =2 mm) had non-SLN positivity (P=0.09). Tumour recurrences after positive SLNs were more than twice as frequent for SLN macrometastases (51.3%) than for micrometastases (24.6%) (P=0.005). For patients with SLN micrometastases, the DFS analysis was worse (P=0.003) when comparing those with positive non-SLNs (60% recurrences) to those without (17.6% recurrences). This difference did not translate into significant differences in DFS: patients with SLN micrometastasis, either with (P=0.022) or without additional positive non-SLNs (P<0.0001), fared worse than patients with tumour-free SLNs. The 2-mm cutoff for SLN tumour load accurately predicts differences in DFS. Non-SLN positivity in CLND, however, cannot be predicted. Therefore, contrary to other studies, no recommendations concerning discontinuation of CLND based on SLN tumour load can be deduced.

Spider silk fibres in artificial nerve constructs promote peripheral nerve regeneration

OBJECTIVE

In our study, we describe the use of spider silk fibres as a new material in nerve tissue engineering, in a 20-mm sciatic nerve defect in rats.

MATERIALS AND METHODS

We compared isogenic nerve grafts to vein grafts with spider silk fibres, either alone or supplemented with Schwann cells, or Schwann cells and matrigel. Controls, consisting of veins and matrigel, were transplanted. After 6 months, regeneration was evaluated for clinical outcome, as well as for histological and morphometrical performance.

RESULTS

Nerve regeneration was achieved with isogenic nerve grafts as well as with all constructs, but not in the control group. Effective regeneration by isogenic nerve grafts and grafts containing spider silk was corroborated by diminished degeneration of the gastrocnemius muscle and by good histological evaluation results. Nerves stained for S-100 and neurofilament indicated existence of Schwann cells and axonal re-growth. Axons were aligned regularly and had a healthy appearance on ultrastructural examination. Interestingly, in contrast to recently published studies, we found that bridging an extensive gap by cell-free constructs based on vein and spider silk was highly effective in nerve regeneration.

CONCLUSION

We conclude that spider silk is a viable guiding material for Schwann cell migration and proliferation as well as for axonal re-growth in a long-distance model for peripheral nerve regeneration.

["True neurologic thoracic outlet syndrome" -- anatomical features and electrophysiological long-term follow-up of lateral thenar atrophy]

Atrophies of the intrinsic muscles of the hand are considered to be a typical symptom of the "true neurologic" form of thoracic outlet syndrome (TOS). The classical form of this entity was described as early as 1970, consisting of a cervical rib or a prolonged transverse process of C7, complete with a fibrous band to the first thoracic rib, resulting in atrophy of the intrinsic muscles of the hand. All our TOS patients presenting with such atrophy displayed anatomical findings consistent with this definition. Based on this observation, the TOS classification currently in clinical use, which differentiates between "disputed" and "true neurologic" subgroups of the neurologic form, is reviewed. In all cases of "true neurologic TOS" with atrophy of the intrinsic muscles of the hand, the lateral thenar muscles are affected first. We present the electrophysiological long-term results of such thenar atrophies of seven patients with eight operated extremities after brachial plexus decompression. The amplitude of the neurographically measured potential over the opponens pollicis and the abductor pollicis brevis muscle, respectively, was defined as quantitative parameter for muscles atrophy. Neither distinct reinnervation nor progressive denervation was evident in any of the cases after a follow-up period, on average, of more than five years post surgery. These findings are in conflict with clinical observations reporting a major postoperative improvement of the motor deficits.

Application of the Zürich Biofilm Model to Problems of Cariology

The term biofilm is increasingly replacing 'plaque' in the literature, but concepts and existing paradigms are changing much more slowly. There is little doubt that biofilm research will lead to more realistic perception and interpretation of the physiology and pathogenicity of microorganisms colonizing plaques in the oral cavity. There is clear evidence that the genotypic and phenotypic expression profiles of biofilm and planktonic bacteria are different. Several techniques are available today to study multispecies biofilms of oral bacteria, each having its particular advantages and weaknesses. We describe a biofilm model developed in Zürich and demonstrate a number of applications with direct or indirect impact on prophylactic dentistry: spatial arrangement and associative behavior of various species in biofilms; multiplex fluorescent in situ hybridization analysis of oral bacteria in biofilms; use of the biofilm model to predict in vivo efficacy of antimicrobials reliably; mass transport in biofilms; de- and remineralization of enamel exposed to biofilms in vitro. The potential of biofilm experimentation in oral biology has certainly not yet been fully exploited and dozens of possible interesting applications could be investigated. The overall physiological parameters of multispecies biofilms can be measured quite accurately, but it is still impossible to assess in toto the multitude of interactions taking place in such complex systems. What can and should be done is to test hypotheses stemming from experiments with planktonic cells in monospecies cultures. In particular, it will be interesting to investigate the relevance to biofilm composition and metabolism of specific gene products by using appropriate bacterial mutants.