Platelets after burn injury - hemostasis and beyond.

Burn injuries are common and often life-threatening trauma. With this trauma comes an interruption of normal hemostasis, with distinct impacts on platelets. Our interest in the relationships between burn injury and platelet function stems from two key perspectives: platelet function is a vital component of acute responses to injury, and furthermore the incidence of cardiovascular disease (CVD) is higher in burn survivors compared to the general population. This review explores the impact of burn injury on coagulation, platelet function, and the participation of platelets in immunopathology. Potential avenues of further research are explored, and consideration is given to what therapies may be appropriate for mediating post-burn thrombopathology.

Microglial contribution to synaptic uptake in the prefrontal cortex in schizophrenia.

Microglia in human post-mortem tissue in schizophrenia patients' brains engulf synaptic material, but not differently to age-matched non-neurological control brains. Also, schizophrenia brains display similar levels of microgliosis to control brains.

Transanal mesorectal excision: early outcomes in Australia and New Zealand.

BACKGROUND: Transanal total mesorectal excision (taTME) aims to overcome some of the technical challenges faced when operating on mid and low rectal cancers. Specimen quality has been confirmed previously, but recent concerns have been raised about oncological safety. This multicentre prospective study aimed to evaluate the safety of taTME among early adopters in Australia and New Zealand. METHODS: Data from all consecutive patients who had taTME for rectal cancer from July 2014 to February 2020 at six tertiary referral centres in Australasia were recorded and analysed. RESULTS: A total of 308 patients of median age of 64 years underwent taTME. Some 75.6 per cent of patients were men, and the median BMI was 26.8 kg/m2. The median distance of tumour from anal verge was 7 cm. Neoadjuvant chemoradiotherapy was administered to 57.8 per cent of patients. The anastomotic leak rate was 8.1 per cent and there was no mortality within 30 days of surgery. Pathological examination found a complete mesorectum in 295 patients (95.8 per cent), a near-complete mesorectum in seven patients (2.3 per cent), and an incomplete mesorectum in six patients (1.9 per cent). The circumferential resection margin and distal resection margin was involved in nine patients (2.9 per cent), and two patients (0.6 per cent) respectively. Over a median follow-up of 22 months, the local recurrence rate was 1.9 per cent and median time to local recurrence was 30.5 months. CONCLUSION: This study showed that, with appropriate training and supervision, skilled minimally invasive rectal cancer surgeons can perform taTME with similar pathological and oncological results to open and laparoscopic surgery.

Endothelin receptor antagonist improves donor lung function in an ex vivo perfusion system.

BACKGROUND: A lung transplant is the last resort treatment for many patients with advanced lung disease. The majority of donated lungs come from donors following brain death (BD). The endothelin axis is upregulated in the blood and lung of the donor after BD resulting in systemic inflammation, lung damage and poor lung graft outcomes in the recipient. Tezosentan (endothelin receptor blocker) improves the pulmonary haemodynamic profile; however, it induces adverse effects on other organs at high doses. Application of ex vivo lung perfusion (EVLP) allows the development of organ-specific hormone resuscitation, to maximise and optimise the donor pool. Therefore, we investigate whether the combination of EVLP and tezosentan administration could improve the quality of donor lungs in a clinically relevant 6-h ovine model of brain stem death (BSD). METHODS: After 6 h of BSD, lungs obtained from 12 sheep were divided into two groups, control and tezosentan-treated group, and cannulated for EVLP. The lungs were monitored for 6 h and lung perfusate and tissue samples were processed and analysed. Blood gas variables were measured in perfusate samples as well as total proteins and pro-inflammatory biomarkers, IL-6 and IL-8. Lung tissues were collected at the end of EVLP experiments for histology analysis and wet-dry weight ratio (a measure of oedema). RESULTS: Our results showed a significant improvement in gas exchange [elevated partial pressure of oxygen (P = 0.02) and reduced partial pressure of carbon dioxide (P = 0.03)] in tezosentan-treated lungs compared to controls. However, the lungs hematoxylin-eosin staining histology results showed minimum lung injuries and there was no difference between both control and tezosentan-treated lungs. Similarly, IL-6 and IL-8 levels in lung perfusate showed no difference between control and tezosentan-treated lungs throughout the EVLP. Histological and tissue analysis showed a non-significant reduction in wet/dry weight ratio in tezosentan-treated lung tissues (P = 0.09) when compared to control. CONCLUSIONS: These data indicate that administration of tezosentan could improve pulmonary gas exchange during EVLP.

Successful patient-oriented surgical outcomes in robotic vs laparoscopic right hemicolectomy for cancer - a systematic review.

AIM: Minimally invasive surgical approaches for cancer of the right colon have been well described with significant patient and equivalent oncological benefits. Robotic surgery has advanced in its ability to provide multi-quadrant abdominal access, leading the surgical community to widen its application outside of the pelvis to other abdominal compartments. Globally it is being realized that a patient's surgical episode of care is becoming the epicentre of cancer treatment. In order to establish the role of robotic surgery in a patient's episode of care, 'successful patient-oriented surgical' parameters in right hemicolectomy for malignancy were measured. The objective was to examine the rates of successful patient-oriented surgical outcomes in robotic right hemicolectomy (RRH) compared to laparoscopic right hemicolectomy (LRH) for cancer. METHODS: A systematic search of MEDLINE (Ovid: 1946-present), PubMed (NCBI), Embase (Ovid: 1966-present) and Cochrane Library was conducted using PRISMA for parameters of successful patient-oriented surgical outcomes in RRH and LRH for malignancy alone. The parameters measured included postoperative ileus, anastomotic complication, surgical wound infection, length of stay (LOS), incisional hernia rate, conversion to open, margin status, lymph node harvest and overall morbidity and mortality. RESULTS: There were 15 studies which included 831 RRH patients and 3241 LRH patients, with a median age of 62-74 years. No study analysed the concept of successful patient-oriented surgical outcomes. There was no significant difference in the incidence of postoperative ileus, with less time to first flatus in RRH (2.0-2.7 days, compared with 2.5-4.0 days, P < 0.05). Anastomotic leak rate in one study reported a significant increase in LRH compared to RRH (P < 0.05, 0% vs 8.3%). Significantly decreased LOS following RRH was outlined in six studies. One study reported a significantly higher rate of incisional hernias following LRH with extracorporeal anastomoses compared to RRH with intracorporeal anastomoses. Overall rates of conversion to open surgery were less with RRH (0%-3.9% vs 0%-18%, P < 0.001, 0.05). One study outlined significantly higher rates of incomplete resection with an open right hemicolectomy compared with minimally invasive laparoscopic and robotic resections, with positive margin rates of 2.3%, 0.9% and 0% respectively (P < 0.001). Two studies reported significantly higher lymph node harvest in RRH (P < 0.05). Overall morbidity and 30-day mortality were comparable in both approaches. CONCLUSION: Thirty-day morbidity and mortality were comparable between the two approaches, with patients undergoing RRH having lower anastomotic complications, increased lymph node harvest, and reduced LOS, conversion to open and incisional hernia rates in a number of studies. There are limited data on surgical approach and impact on quality of life and what patients deem successful surgical outcomes. There is a further need for a randomized controlled trial examining successful patient-oriented outcomes in right hemicolectomy for malignancy.

Broadband NIRS Cerebral Evaluation of the Hemodynamic and Oxidative State of Cytochrome-c-Oxidase Responses to +Gz Acceleration in Healthy Volunteers.

We used a miniature broadband NIRS system to monitor concentration changes in brain oxygenation (oxy- and deoxy- haemoglobin [HbO2], [HHb]) and oxidised cytochrome-c-oxidase ([oxCCO]) during a high +Gz acceleration, induced by a human centrifuge, on two healthy experienced volunteers (2 male, 34 and 37 years). We performed a sequence of several +Gz exposures that were terminated at the onset of visual symptoms (loss of peripheral vision). Systemic parameters were recorded (i.e. heart rate, blood pressure and arterial saturation), and brain tissue blood volume changes ([HbT] = [HbO2] + [HHb]) and oxygen delivery ([HbDiff] = [HbO2] - [HHb]) were calculated. Volunteer 1 demonstrated a decrease in [HbT] of -3.49 ± 0.02 µMol and [HbDiff] of -3.23 ± 0.44 µMol, and an increase of [oxCCO] of 0.42 ± 0.01µMol. Volunteer 2 demonstrated a decrease in [HbDiff] of -4.37 ± 0.23 µMol, and no significant change in [HbT] (0.53 ± 0.06 µMol) and [oxCCO] (0.09 ± 0.06 µMol). The variability of the brain metabolic response was related to the level of ischaemia, suggesting that suppression of metabolism was due to lack of glucose substrate delivery rather than oxygen availability.

Surgical techniques in the management of rectal cancer: a modified Delphi method by colorectal surgeons in Australia and New Zealand.

BACKGROUND: Technological developments have allowed advances in minimally invasive techniques for total mesorectal excision such as laparoscopy, robotics, and transanal surgery. There remains an ongoing debate about the safety, benefits, and appropriate clinical scenarios for which each technique is employed. The aim of this study was to provide a panel of expert opinion on the role of each surgical technique currently available in the management of rectal cancer using a modified Delphi method. METHODS: Surveys were designed to explore the key patient- and tumor-related factors including clinical scenarios for determining a surgeon's choice of surgical technique. RESULTS: Open surgery was favoured in obese patients with an extra-peritoneal tumor and a positive circumferential resection margin (CRM) or T4 tumor when a restorative resection was planned. Laparoscopy was favoured in non-obese males and females, in both intra- and extra-peritoneal tumors with a clear CRM. Robotic surgery was most commonly offered to obese patients when the CRM was clear and if an abdominoperineal resection was planned. Transanal total mesorectal excision (taTME) was preferred in male patients with a mid or low rectal cancer, particularly when obese. Transanal endoscopic microsurgery/transanal minimally invasive surgery local excision was only offered to frail patients with small, early stage tumors. CONCLUSIONS: All surgical techniques for rectal cancer dissection have a role and may be considered appropriate. Some techniques have advantages over others in certain clinical situations, and the best outcomes may be achieved by considering all options before applying an individualised approach to each clinical situation.

RNA-Seq Analysis of Differentiated Keratinocytes Reveals a Massive Response to Late Events during Human Papillomavirus 16 Infection, Including Loss of Epithelial Barrier Function.

The human papillomavirus (HPV) replication cycle is tightly linked to epithelial cell differentiation. To examine HPV-associated changes in the keratinocyte transcriptome, RNAs isolated from undifferentiated and differentiated cell populations of normal, spontaneously immortalized keratinocytes (NIKS) and NIKS stably transfected with HPV16 episomal genomes (NIKS16) were compared using next-generation sequencing (RNA-Seq). HPV16 infection altered expression of 2,862 cellular genes. Next, to elucidate the role of keratinocyte gene expression in late events during the viral life cycle, RNA-Seq was carried out on triplicate differentiated populations of NIKS (uninfected) and NIKS16 (infected). Of the top 966 genes altered (>log2 = 1.8, 3.5-fold change), 670 genes were downregulated and 296 genes were upregulated. HPV downregulated many genes involved in epithelial barrier function, which involves structural resistance to the environment and immunity to infectious agents. For example, HPV infection repressed expression of the differentiated keratinocyte-specific pattern recognition receptor TLR7, the Langerhans cell chemoattractant CCL20, and proinflammatory cytokines interleukin 1α (IL-1α) and IL-1ß. However, the type I interferon regulator IRF1, kappa interferon (IFN-κ), and viral restriction factors (IFIT1, -2, -3, and -5, OASL, CD74, and RTP4) were upregulated. HPV infection abrogated gene expression associated with the physical epithelial barrier, including keratinocyte cytoskeleton, intercellular junctions, and cell adhesion. Quantitative PCR (qRT-PCR) and Western blotting confirmed changes in expression of seven of the most significantly altered mRNAs. Expression of three genes showed statistically significant changes during cervical disease progression in clinical samples. Taken together, the data indicate that HPV infection manipulates the differentiating keratinocyte transcriptome to create an environment conducive to productive viral replication and egress.IMPORTANCE HPV genome amplification and capsid formation take place in differentiated keratinocytes. The viral life cycle is intimately associated with host cell differentiation. Deep sequencing (RNA-Seq) of RNA from undifferentiated and differentiated uninfected and HPV16-positive keratinocytes showed that almost 3,000 genes were differentially expressed in keratinocytes due to HPV16 infection. Strikingly, the epithelial barrier function of differentiated keratinocytes, comprising keratinocyte immune function and cellular structure, was found to be disrupted. These data provide new insights into the virus-host interaction that is crucial for the production of infectious virus and reveal that HPV infection remodels keratinocytes for completion of the virus replication cycle.

An assessment of an Australasian pathway for the introduction of transanal total mesorectal excision (taTME).

AIM: To evaluate the use of a pathway for the introduction of transanal total mesorectal excision (taTME) into Australia and New Zealand. METHOD: A pathway for surgeons with an appropriate level of specialist training and baseline skill set was initiated amongst colorectal surgeons; it includes an intensive course, a series of proctored cases and ongoing contribution to audit. Data were collected for patients who had taTME, for benign and malignant conditions, undertaken by the initial adopters of the technique. RESULTS: A total of 133 taTME procedures were performed following the introduction of a training pathway in March 2015. The indication was rectal cancer in 84% of cases. There was one technique-specific visceral injury, which occurred prior to that surgeon completing the pathway. There were no cases of postoperative mortality; morbidity occurred in 27.1%. The distal resection margin was clear in all cases of rectal cancer, and the circumferential resection margin was positive in two cases. An intact or nearly intact total mesorectal excision was obtained in more than 98% of cases. CONCLUSION: This study demonstrates the safe and controlled introduction of a new surgical technique in a defined surgeon population with the use of a pathway for training. The authors recommend a similar pathway to facilitate the introduction of taTME to colorectal surgical practice.

Robotic transanal minimally invasive surgery (TAMIS) for local excision of rectal lesions with the da Vinci Xi (dVXi): technical considerations and video vignette.

Robotic transanal minimally invasive surgery (TAMIS) (RT) represents a compelling new alternative capable of overcoming the limitations of conventional TAMIS for the local excision of rectal lesions. We describe our RT technique using the dVXi™ (Intuitive Surgical, Sunnyvale, CA, USA) which we have used to efficiently and completely excise eight cases of rectal lesions which were not endoscopically resectable. We also include a video vignette of the procedure. With the patient in the prone jackknife position, we insert a GelPOINT™ Path Transanal Access Platform (Applied Medical, Rancho Santa Margarita, CA, USA) in combination with the dVXi and AirSeal™ insufflation system (Conmed, Niagara. Falls, ON, Canada). Our technique aims to be ergonomically efficient to minimise docking difficulties and to reduce instrument clash in the limited space, whilst maximising the capabilities of the dVXi for RT. At 3-month endoscopic follow-up, no evidence of recurrence was detected in any of the eight patients. RT is safe, feasible and has advantages over conventional laparoscopic TAMIS (LT). Our described technique addresses some of the long-standing challenges of LT and the novel RT. The immediate challenge to its widespread use remains the cost, expertise and availability.

The effect of bitewing radiography on estimates of dental caries experience among children differs according to their disease experience.

BACKGROUND: Radiography is a regularly used and accepted adjunct to visual examination in the diagnosis of dental caries. It is assumed that not using radiographs can lead to underestimation of dental caries experience with most reports having involved studies of young adults or adolescents, and been focused on the permanent dentition. The aim of this study was to determine the relative contributions of bitewing radiography and clinical examination in the detection of dental caries in primary molars and to determine whether those contributions differ according to caries experience. METHODS: A cross-sectional study was conducted, involving examinations undertaken in dental clinics. Bitewing radiographs taken at the time of the clinical examination were developed and read later, with the data from those used at the analysis stage to adjust the caries diagnosis for the mesial, occlusal and distal surfaces of the primary molar teeth. Children's clinically determined dmfs score was used to allocate them to one of three caries experience groups (0 dmfs, 1-8 dmfs, or 9+ dmfs). RESULTS: Of the 501 three-to-eight-year-old children examined, nearly three-quarters were younger than six. Caries prevalence and mean dmfs after clinical examination alone and following radiographs were 63.1% and 4.6 (sd, 6.2), and 74.7% and 5.8 (sd, 6.5) respectively. Among children with a dmfs of 1-8, the number of lesions missed during the clinical examination was greater than the number of 106 (25.6%) in children with a dmfs of 9+. In the 185 children with no apparent caries at clinical examination, 124 lesions were detected radiographically, among 58 (46.8%) of those. CONCLUSIONS: Taking bitewing radiographs in young children is not without challenges or risks, and it must be undertaken with these in mind. Diagnostic yields from bitewing radiographs are greater for children with greater caries experience. The findings of this study further support the need to consider using bitewing radiographs in young children to enhance the management of lesions not detected by a simple visual examination alone. TRIAL REGISTRATION: ACTRN12614000844640 .

Impact of simulated three-dimensional perception on precision of depth judgements, technical performance and perceived workload in laparoscopy.

BACKGROUND: This study compared precision of depth judgements, technical performance and workload using two-dimensional (2D) and three-dimensional (3D) laparoscopic displays across different viewing distances. It also compared the accuracy of 3D displays with natural viewing, along with the relationship between stereoacuity and 3D laparoscopic performance. METHODS: A counterbalanced within-subjects design with random assignment to testing sequences was used. The system could display 2D or 3D images with the same set-up. A Howard-Dolman apparatus assessed precision of depth judgements, and three laparoscopic tasks (peg transfer, navigation in space and suturing) assessed performance (time to completion). Participants completed tasks in all combinations of two viewing modes (2D, 3D) and two viewing distances (1 m, 3 m). Other measures administered included the National Aeronautics and Space Administration Task Load Index (perceived workload) and the Randot® Stereotest (stereoacuity). RESULTS: Depth judgements were 6·2 times as precise at 1 m and 3·0 times as precise at 3 m using 3D versus 2D displays (P < 0·001). Participants performed all laparoscopic tasks faster in 3D at both 1 and 3 m (P < 0.001), with mean completion times up to 64 per cent shorter for 3D versus 2D displays. Workload was lower for 3D displays (up to 34 per cent) than for 2D displays at both viewing distances (P < 0·001). Greater viewing distance inhibited performance for two laparoscopic tasks, and increased perceived workload for all three (P < 0·001). Higher stereoacuity was associated with shorter completion times for the navigating in space task performed in 3D at 1 m (r = - 0·40, P = 0·001). CONCLUSION: 3D displays offer large improvements over 2D displays in precision of depth judgements, technical performance and perceived workload.

Editor's Choice - Inequalities in Abdominal Aortic Aneurysm Screening in England: Effects of Social Deprivation and Ethnicity.

OBJECTIVE: Population screening for abdominal aortic aneurysm (AAA) in men is currently ongoing in several countries. The aim was to examine the effects of deprivation and ethnicity on uptake of screening for abdominal aortic aneurysm (AAA) and prevalence of AAA. METHODS: This was a review of outcomes from a population screening programme using data collected contemporaneously on a bespoke national database. Men aged 65 in two annual cohorts (2013/14 and 2014/15) were invited for AAA screening. Attendance and prevalence of AAA (aortic diameter >2.9 cm) were recorded. Results were compared according to measures of social deprivation and recorded ethnicity. RESULTS: Some 593,032 men were invited and 461,898 attended for ultrasound screening; uptake 77.9%. Uptake was related to social deprivation: 65.1% in the most deprived decile, 84.1% in the least deprived: OR for least deprived 2.84, 95% CI 2.76-2.92, p<.0001. Men in deprived areas were more likely to actively decline screening: 6% versus 3.8% in the least deprived decile. AAA were twice as common in the most deprived compared with the least deprived decile: OR 2.1, 95% CI 1.77-2.27, p<.0001. AAA were more common in white British men than in black (OR 0.46, 95% CI 0.31-0.71) or Asian (OR 0.18, 95% CI 0.13-0.26) men. There was considerable local variation in all findings. CONCLUSIONS: Social deprivation affects uptake of AAA screening in 65 year old men. Local factors are the most important determinants of uptake, so solutions to improve uptake must be designed at local, not national level.

Convergence of ipsi- and contralateral muscle afferents on common interneurons mediating reciprocal inhibition of ankle plantarflexors in humans.

Recent studies have shown that afferents arising from muscle receptors located on one side can affect the activity of muscles on the contralateral side. In animal preparations, evidence supports that afferent pathways originating from one limb converge onto interneurons mediating disynaptic reciprocal Ia inhibition of the opposite limb. This study was designed to investigate whether this pathway is similar in humans to that described in animals. Thirteen healthy volunteers participated in one of two experiments. In experiment 1, the effects of ipsilateral posterior tibial nerve (iPTN) stimulation were assessed on the reciprocal Ia inhibition of the contralateral soleus (cSOL) motoneuronal pool (n = 8). Across all participants, iPTN stimulation intensity was 1.69 ± 0.3 × Motor Threshold (MT) and contralateral common peroneal (cCPN) stimulation intensity was 0.86 ± 0.16 × MT. iPTN and cCPN stimulation were delivered separately or in combination and changes in the ongoing electromyography (EMG) quantified. In experiment 2, the amplitude of a test SOL H-reflex elicited by contralateral PTN (cPTN) stimulation was quantified following iPTN, cCPN or iPTN + cCPN nerve stimulation (n = 5). Intensities used during the H-reflex conditioning experiment were 1.79 ± 0.4 × MT for the iPTN stimulation and 0.88 ± 0.16 × MT for cCPN stimulation. Across all participants, the onset of the cSOL EMG suppression was 42 ± 4, 44 ± 3 and 44 ± 3 ms for iPTN, cCPN and iPTN + cCPN conditions, respectively. The inhibition from the combined iPTN and cCPN stimulation was significantly greater compared to the algebraic sum of their separate effects. When conditioning the cSOL H-reflex, the ISI between the test cPTN and the iPTN or cCPN stimulus was 5.4 ± 0.5 and 2.6 ± 0.5, respectively. The combined stimulation induced a significantly greater inhibition compared to their separate effects. These data provide evidence of convergence on common inhibitory interneurons by muscle afferents activated by iPTN and cCPN stimulation during sitting. Since the inhibition elicited by cCPN stimulation is known to be mediated by the disynaptic Ia inhibitory pathway, this suggests that the crossed inhibition of cSOL motoneurones elicited by muscle afferents from the ipsilateral plantarflexor muscles is at least partly mediated by Ia inhibitory interneurons in the contralateral human spinal cord. This is similar to what has been observed in the cat.

Percutaneous internal fixation of pelvic fractures.

BACKGROUND: Percutaneous internal fixation of pelvic fractures is increasing in popularity with multiple new techniques reported. OBJECTIVES: The purpose of this article is to outline the imaging, indication, planning, equipment, surgical technique and complications of these methods. METHODS: A review of the literature is provided and the techniques for anterior and posterior pelvic stabilisation are discussed. RESULTS: High-quality preoperative CT scans are essential in planning for this technique. The anterior internal fixator ("InFix") is an effective method for stabilising the anterior ring and should be usually used in conjunction with posterior fixation. Good technique avoids neurovascular injury, which can be a devastating complication. The retrograde anterior column screw (RACS) is a technique that can be used in most patients, although in smaller patients smaller screw diameters may be needed. The entry point for the screw is more lateral in women than men. Iliosacral screws (ISS) are an effective method of posterior stabilisation and can be placed using 2D or 3D fluoroscopy, computer navigation or CT navigation. CONCLUSION: Percutaneous fixation of pelvic fractures requires high-quality imaging and can be aided by computer navigation. Safe techniques are reproducible; however, not all patients and fracture patterns can be treated using these techniques.

Impact of the first 5 years of a national abdominal aortic aneurysm screening programme.

BACKGROUND: The Abdominal Aortic Aneurysm (AAA) Screening Programme was introduced by the National Health Service (NHS) in England to reduce the rate of death from ruptured AAA in men. The programme commenced in 2009 and was implemented completely across the country in April 2013. The aim was to review the first 5 years of the programme, looking specifically at compliance and early outcome. METHODS: Men aged 65 years were invited for a single abdominal ultrasound scan. Data were entered into a bespoke database (AAA SMaRT). This was a planned analysis after the first 5 years of the programme. RESULTS: The summation analysis involved the first 700 000 men screened, and the first 1000 men with a large AAA referred for possible treatment. The prevalence of AAA (aortic diameter larger than 2·9 cm) in 65-year-old men was 1·34 per cent. Mean uptake was 78·1 per cent, but varied from 61·7 to 85·8 per cent across the country. Based on the Index of Multiple Deprivation, uptake was 65·1 per cent in the most deprived versus 84·1 per cent in the least deprived areas. Of the first 1000 men referred for possible treatment of a large AAA (greater than 5·4 cm), the false-positive rate was 3·2 per cent. Some 870 men underwent a planned AAA intervention (non-intervention rate 9·2 per cent), with seven deaths (perioperative mortality rate 0·8 per cent). CONCLUSION: The processes in the NHS AAA Screening Programme are effective in detecting and treating men with AAA.

Transanal total mesorectal excision: dissection tips using 'O's and 'triangles'.

PURPOSE: Transanal total mesorectal excision (taTME) requires specific technical expertise, as it is often difficult to ascertain the correct dissection plane. Consequently, one can easily enter an incorrect plane, potentially resulting in bleeding (sidewall or presacral vessels), autonomic nerve injury and urethral injury. We aim to demonstrate specific visual features, which may be encountered during surgery and can guide the surgeon to perform the dissection in the correct plane. METHOD: Specific features of dissection in the correct and incorrect planes are demonstrated in the accompanying video. RESULTS: The 'triangles' created using appropriate traction can aid in performing a precise dissection in the correct plane. Recognition of features described as 'O's can alert surgeons that they are entering a new fascial plane and can avoid incursion into an incorrect plane. CONCLUSION: Understanding and recognizing the described features which can be encountered in taTME surgery, a safe and accurate TME dissection can be facilitated.

[Percutaneous internal fixation of pelvic fractures. German version]. / Perkutane interne Fixation bei Beckenfrakturen.

BACKGROUND: Percutaneous internal fixation of pelvic fractures is increasing in popularity with multiple new techniques reported. OBJECTIVES: The purpose of this article is to outline the imaging, indication, planning, equipment, surgical technique and complications of these methods. METHODS: A review of the literature is provided and the techniques for anterior and posterior pelvic stabilization are discussed. RESULTS: High-quality preoperative CT scans are essential in planning for this technique. The anterior internal fixator ("InFix") is an effective method for stabilizing the anterior ring and should be usually used in conjunction with posterior fixation. Good technique avoids neurovascular injury, which can be a devastating complication. The retrograde anterior column screw (RACS) is a technique that can be used in most patients, although in smaller patients smaller screw diameters may be needed. The entry point for the screw is more lateral in women than men. Iliosacral screws (ISS) are an effective method of posterior stabilization and can be placed using 2D or 3D fluoroscopy, computer navigation or CT navigation. CONCLUSION: Percutaneous fixation of pelvic fractures requires high-quality imaging and can be aided by computer navigation. Safe techniques are reproducible; however, not all patients and fracture patterns can be treated using these techniques.

Increased gravitational force reveals the mechanical, resonant nature of physiological tremor.

KEY POINTS: Physiological hand tremor has a clear peak between 6 and 12 Hz, which has been attributed to both neural and resonant causes. A reduction in tremor frequency produced by adding an inertial mass to the limb has usually been taken as a method to identify the resonant component. However, adding mass to a limb also inevitably increases the muscular force required to maintain the limb's position against gravity, so ambiguous results have been reported. Here we measure hand tremor at different levels of gravitational field strength using a human centrifuge, thereby increasing the required muscular force to preserve limb position without changing the limb's inertia. By comparing the effect of added mass (inertia + force) versus solely added force upon hand acceleration, we conclude that tremor frequency can be almost completely explained by a resonant mechanical system. ABSTRACT: Human physiological hand tremor has a resonant component. Proof of this is that its frequency can be modified by adding mass. However, adding mass also increases the load which must be supported. The necessary force requires muscular contraction which will change motor output and is likely to increase limb stiffness. The increased stiffness will partly offset the effect of the increased mass and this can lead to the erroneous conclusion that factors other than resonance are involved in determining tremor frequency. Using a human centrifuge to increase head-to-foot gravitational field strength, we were able to control for the increased effort by increasing force without changing mass. This revealed that the peak frequency of human hand tremor is 99% predictable on the basis of a resonant mechanism. We ask what, if anything, the peak frequency of physiological tremor can reveal about the operation of the nervous system.