Mark Midwinter
The University of Queensland, Australia, General Surgery, Faculty Member
- Academic surgeon, anatomist, dispeller of dogmaedit
BackgroundIn our experience, the anterior carotid sheath forms an important plane of dissection when excising temporal bone region cancers. However, its anatomical composition, relationships, and radiological appearance remains... more
BackgroundIn our experience, the anterior carotid sheath forms an important plane of dissection when excising temporal bone region cancers. However, its anatomical composition, relationships, and radiological appearance remains unclear.MethodsEight sides of cadaveric heads were dissected. Anatomical findings were correlated with a high‐resolution baseline T1 MRI.ResultsThe anterior carotid sheath was formed by the tensor‐vascular‐styloid fascia, stylopharyngeal fascia, buccopharyngeal fascia (BPF), and longus capitis fascia (LCF), and appeared as a hypointense line on MRI. Not previously described, the glossopharyngeal nerve pierced the sheath 9.0 mm (SD 2.1 mm) below the skull base and traveled through its LCF and BPF layers to exit near the pharynx.ConclusionMultiple fascial layers formed the anterior carotid sheath at the skull base, and this was radiologically identifiable. Further studies are required to validate findings and investigate the role this fascial plane has in forming an effective barrier to spread of malignancy.
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Introduction The concentration of major trauma experience at Camp Bastion has allowed continuous improvements to occur in the patient pathway from the point of wounding to surgical treatment. These changes have involved clinical... more
Introduction The concentration of major trauma experience at Camp Bastion has allowed continuous improvements to occur in the patient pathway from the point of wounding to surgical treatment. These changes have involved clinical management as well as alterations to the physical layout of the hospital, training and decision making. Consideration of the human factors has been a major part of these improvements. Methods We describe the Camp Bastion patient pathway with the communication template that focused decision making at various key moments during damage control resuscitation and damage control surgery (DCR–DCS). This system identifies four key stages: ‘command huddle’, ‘snap brief’, ‘sit-reps’ (situation reports) and ‘sign-out/debrief’. The attitude of staff to communication and decision making is also evaluated. Results Twenty cases admitted to Camp Bastion with battlefield injuries were studied from 6 September to 6 October 2012. Qualitative responses from 115 members of staff...
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ObjectiveTo examine the relationship between sublingual microcirculatory measures and frailty index in those attending a kidney transplant assessment clinic.MethodsPatients recruited had their sublingual microcirculation taken using... more
ObjectiveTo examine the relationship between sublingual microcirculatory measures and frailty index in those attending a kidney transplant assessment clinic.MethodsPatients recruited had their sublingual microcirculation taken using sidestream dark field videomicroscopy (MicroScan, Micro Vision Medical, Amsterdam, the Netherlands) and their frailty index score using a validated short form via interview.ResultsA total of 44 patients were recruited with two being excluded due to microcirculatory image quality scores exceeding 10. The frailty index score indicated significant correlations with total vessel density (p < .0001, r = −.56), microvascular flow index (p = .004, r = −.43), portion of perfused vessels (p = .0004, r = −.52), heterogeneity index (p = .015, r = .32), and perfused vessel density (p < .0001, r = −.66). No correlation was shown between the frailty index and age (p = .08, r = .27).ConclusionsThere is a relationship between the frailty index and microcirculatory health in those attending a kidney transplant assessment clinic, that is not confounded by age. These findings suggest that the impaired microcirculation may be an underlying cause of frailty.
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Research Interests: Surgery, Risk assessment, Vascular Surgery, Medicine, Humans, and 13 moreAudit, Emergency Surgery, Morbidity, Survival Rate, Risk Assessment, Sensitivity and Specificity, Predictive value of tests, Mortality rate, Severity of Illness Index, Vascular Diseases, Scoring system, Medical and Health Sciences, and Vascular surgical procedures
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British Journal of Surgery 1996, 83, 812-815 An evaluation of the POSSUM surgical scoring system M. S. WHITELEY, DR PRYTHERCH, B. HIGGINS*, PC WEAVER and W. G. PROUT ... Page 3. 814 MS WHITELEY, DR PRYTHERCH, B. HIGGINS, PC WEAVER and WG... more
British Journal of Surgery 1996, 83, 812-815 An evaluation of the POSSUM surgical scoring system M. S. WHITELEY, DR PRYTHERCH, B. HIGGINS*, PC WEAVER and W. G. PROUT ... Page 3. 814 MS WHITELEY, DR PRYTHERCH, B. HIGGINS, PC WEAVER and WG PROUT ...
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It is generally accepted that the human abdominal wall is comprised of skin, subcutaneous tissues, muscles and their aponeuroses, and the parietal peritoneum. Understanding these layers and their mechanical properties provides valuable... more
It is generally accepted that the human abdominal wall is comprised of skin, subcutaneous tissues, muscles and their aponeuroses, and the parietal peritoneum. Understanding these layers and their mechanical properties provides valuable information to those designing procedural skills trainers, supporting surgical procedures (hernia repair), and engineering-based work (in silico simulation). However, there is little literature available on the mechanical properties of the abdominal wall in layers or as a composite. This work characterizes the tensile properties of the human abdominal wall by layer and as a partial composite. Tissues were collected from fresh-never-frozen and fresh-frozen cadavers and tested in uniaxial tension at a rate of 5 mm/min until failure. Stress-strain curves were created for each sample, and the values for elastic moduli, ultimate tensile strength, and strain at failure were obtained. The experimental outcomes from this study demonstrated variation of tensil...
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Objective: The objective of this scoping review is to identify the availability of quantitative biomechanical measurements from human tissues. This review will also consider the primary motivations for collecting biomechanical... more
Objective: The objective of this scoping review is to identify the availability of quantitative biomechanical measurements from human tissues. This review will also consider the primary motivations for collecting biomechanical measurements of human tissues. The overall purpose of our research is to develop medical skills trainers that provide better haptic fidelity than those that are currently available. Introduction: Medical skills trainers are commonly used in clinician training, but trainers do not always have the same haptic properties as patients. This could be due to the limited availability or application of documented biomechanical properties of human tissues when developing trainers. Inclusion criteria: This scoping review will examine studies that have quantitatively measured the mechanical properties of human tissues. Only macroscopic specimens will be included, and articles primarily considering optical, acoustic, and thermal properties will be excluded. Included sources of evidence are from primary research, systematic reviews, meta-analyses, and conference proceedings. Methods: This review will follow the JBI methodology for scoping reviews. Sources of evidence will be extracted from CINAHL, IEEE Xplore, MEDLINE, Scopus, and biomedical engineering conference proceedings. The search is limited to articles in English. Full articles will be retrieved if their title or abstract meet the inclusion criteria. Tabular, visual, and narrative summaries will be used to present the results. Scoping review protocol registration: Open Science Framework https://osf.io/fgb34
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The treatment of traumatic shock has changed unrecognizably over the past decade as the combination of targeted research and lessons learnt from conflict have combined with a common goal. The term damage control resuscitation has emerged... more
The treatment of traumatic shock has changed unrecognizably over the past decade as the combination of targeted research and lessons learnt from conflict have combined with a common goal. The term damage control resuscitation has emerged as the most likely strategy to treat the underlying cause, restore normal physiology and ultimately return to normal function. However, there is still a great deal that we do not understand as to the underlying mechanisms which control the traumatic shock process. Military surgeons have an integral part to play at every step of this process. Their role does not end once the initial damage control surgery is complete and indeed the decisions that are made during the initial resuscitation will have an effect on all future stages of care. The patient's physiology is delicately balanced with the possibility that a wrong treatment decision may be a fatal one. It is essential that the surgeon has an understanding of these underlying processes so that an informed decision can be made at the right time.
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The closure of the Medical Treatment facility in Camp BASTION and the return to contingency operations presents a new challenge in training and maintaining the skills of military surgeons. Multivisceral organ retrieval presents a unique... more
The closure of the Medical Treatment facility in Camp BASTION and the return to contingency operations presents a new challenge in training and maintaining the skills of military surgeons. Multivisceral organ retrieval presents a unique opportunity to practice some of the more unusual techniques required in military surgery in the National Health Service. This article details the experience that organ retrieval offers and matches this to the needs of military surgeons. National Organ Retrieval Service teams need skilled surgeons, and a mutually beneficial partnership is in prospect.
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In recent conflicts, many UK personnel sustained head injuries requiring damage-control surgery and aeromedical transfer to the UK. This study aims to examine indications, complications and outcomes of UK military casualties undergoing... more
In recent conflicts, many UK personnel sustained head injuries requiring damage-control surgery and aeromedical transfer to the UK. This study aims to examine indications, complications and outcomes of UK military casualties undergoing craniectomy and cranioplasty from conflicts in Afghanistan and Iraq. The UK military Joint Theatre Trauma Registry (JTTR) was searched for all UK survivors in Afghanistan and Iraq between 2004 and 2014 requiring craniectomy and cranioplasty resulting from trauma. Fourteen decompressive craniectomies and cranioplasties were performed with blast and gunshot wounds equally responsible for head injury. Ten survivors (71%) had an Injury Severity Score (ISS) of 75, normally designated as 'unsurvivable'. Most were operated on the day of injury. Seventy-one percent received a reverse question mark incision and 7% received a bicoronal incision. Seventy-nine percent had bone flaps discarded. Overall infection rate was 43%. Acinetobacter spp was the causative organism in 50% of cases. Median Glasgow Outcome Scale (GOS) at final follow-up was 4. All casualties had a GOS score greater than 3. Timely neurosurgical intervention is imperative for military personnel given high survival rates in those sustaining what are designated 'un-survivable' injuries. Early decompression facilitates safe aeromedical evacuation of casualties. Excellent outcomes validate the UK military trauma system and the stepwise performance gains throughout recent conflicts however trauma registers most evolving to have specific relevance to military casualties. In high-energy trauma with contamination and soft-tissue destruction, surgery should be conducted with regard for future soft tissue reconstruction. Bone flaps should be discarded and cranioplasty performed according to local preference. Facilities receiving military casualties should have specialist microbiological input mindful of the difficulties treating unusual microbes.
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Understanding the interaction of foreign tissue with the recipient immune system is key to improving results from organ transplantation. Responses are mediated by the humoral and cellular arms of the host immune system towards the tissues... more
Understanding the interaction of foreign tissue with the recipient immune system is key to improving results from organ transplantation. Responses are mediated by the humoral and cellular arms of the host immune system towards the tissues of the transplant. Unchecked this can lead to rejection of the graft. Improvements in immunosuppressive therapy have countered these reactions to a degree but are not without side effects. Future work is directed at improving graft tolerance without unwanted host effects
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Research Interests: Pathology, Gastroenterology, Protein, Medicine, Angiogenesis, and 15 moreColorectal cancer, Multivariate Analysis, Humans, Internal Medicine, Histopathology, Clinical Sciences, Carcinoma, Observer Variation, Colon cancer, Prognosis, Ploidy, Rectal Cancer, Adenocarcinoma, Predictor, and Colonic Neoplasms
The immune system provides the body with both non-specific and specific defence against pathogens. It can recognize foreign from self. The immune system is composed of lines of defence and can mount responses by cellular and humoral... more
The immune system provides the body with both non-specific and specific defence against pathogens. It can recognize foreign from self. The immune system is composed of lines of defence and can mount responses by cellular and humoral mechanisms. It also has memory, allowing a quicker and heightened response on subsequent exposure. It achieves these effects by a complex interaction between the clotting, complement and kinin systems, endothelial cells and the cells and proteins of the immune system
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BackgroundContention exists amongst anatomists, clinicians and surgeons about how much anatomical knowledge medical students need, although what is taught should be aligned with current surgical practice. The aim of this study was to... more
BackgroundContention exists amongst anatomists, clinicians and surgeons about how much anatomical knowledge medical students need, although what is taught should be aligned with current surgical practice. The aim of this study was to explore the scope of recent advances in applied anatomy as highlighted in the ANZ Journal of Surgery in each of the surgical specialties.MethodsThe 2018 volume of the ANZ Journal of Surgery was narrowed to 254 articles by applying the search term ‘anatomy’. The main topic was extracted from each paper. The content of the paper was assessed for ‘novel description’ or ‘novel application’ of anatomical knowledge and classified accordingly.ResultsMost papers with an anatomical focus were from general surgery, which focused on surgical techniques, outcomes and management. Vascular surgery had the highest percentage of papers with a novel description and application of anatomy. Although cardiothoracic and paediatric surgery had no papers with a novel descript...
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Objectives: A dysfunctional microcirculation is universal in shock and is often dissociated from global hemodynamic parameters. Persistent microcirculatory derangements reflect ongoing tissue hypoperfusion and organ injury. The initial... more
Objectives: A dysfunctional microcirculation is universal in shock and is often dissociated from global hemodynamic parameters. Persistent microcirculatory derangements reflect ongoing tissue hypoperfusion and organ injury. The initial microcirculatory dysfunction and subsequent resolution could potentially guide therapy and predict outcomes. We evaluated the microcirculation early in a heterogenous shocked population. Microcirculatory resolution was correlated with measures of tissue perfusion and global hemodynamics. The relationship between the microcirculation over 24 h and outcome were evaluated. Design: We prospectively recruited patients with all forms of shock, based on global hemodynamics and evidence of organ hypoperfusion. Setting: A 30-bed adult intensive care unit (ICU). Patients: Eighty-two shocked patients. Measurements and Main Results: Following the diagnosis of shock, patients underwent a sublingual microcirculation examination using Sidestream Dark Field Imaging. ...
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This study defines the patterns of perineal injury due to blast currently seen on operations. It refines our team-based surgical strategies of surgical resuscitation provides an evidence base for a perineal debridement - colonic diversion... more
This study defines the patterns of perineal injury due to blast currently seen on operations. It refines our team-based surgical strategies of surgical resuscitation provides an evidence base for a perineal debridement - colonic diversion didactic on the Military Operational Surgical Training (MOST) course. The Joint Theatre Trauma Registry (JTTR) held at RCDM was examined from 1 January 2003 to 31 December 2010. Data abstracted included patient demographics, mechanism of injury, injury severity score (ISS), treatment, management, length of stay (LOS) and outcomes. Of 4807 military trauma patients, 118 (2.5%) had a recorded perineal injury, 56 died (48% all IED). Pelvic fractures were identified in 63 (53%) of which 17 (27%) survived. Mortality rates were significantly different between the combined perineal & pelvic fracture group compared to pelvic fracture & perineal injuries alone (41% & 18% respectively, p = 0.0001). Mean ISS for all patients was 41.03. Those with a pelvic frac...
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BackgroundCompared with similarly injured patients of a younger age, elderly patients have worse outcomes from acute injury. One factor adversely affecting outcomes is sarcopenia, which has been assessed in healthy elderly populations... more
BackgroundCompared with similarly injured patients of a younger age, elderly patients have worse outcomes from acute injury. One factor adversely affecting outcomes is sarcopenia, which has been assessed in healthy elderly populations through established clinical and radiological criteria. However, in the acute care setting, no such criteria have been established. Sarcopenia has been opportunistically assessed via radiographic means but there is as of yet no gold standard. The purpose of this review is to summarize the radiological methods used to diagnose sarcopenia in the acute care setting, and suggest ways in which these methods may lead to a consensus definition of sarcopenia and its relationship to patient outcomes.MethodsA systematic survey of medical databases was conducted, with 902 unique publications identified. After screening and application of inclusion and exclusion criteria, data regarding study population, outcome, imaging modality, and criteria for assessment of sa...
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Damage Control Resuscitation and Damage Control Surgery (DCR-DCS) is an approach to managing severely injured patients according to their physiological needs, in order to optimise outcome. Key to delivering DCR-DCS is effective... more
Damage Control Resuscitation and Damage Control Surgery (DCR-DCS) is an approach to managing severely injured patients according to their physiological needs, in order to optimise outcome. Key to delivering DCR-DCS is effective communication between members of the clinical team and in particular between the surgeon and anaesthetist, in order to sequence and prioritise interventions. Although the requirement for effective communication is self-evident, the principles to achieving this can be forgotten and sub-optimal when unexpected problems arise at critical points during management of challenging cases. A system is described which builds on the 'World Health Organisation (WHO) safer surgery checklist' and formalises certain stages of communication in order to assure the effective passage of key points. We have identified 3 distinct phases: (i) The Command Huddle, once the patient has been assessed in the Emergency room; (ii) The Snap Brief, once the patient has arrived in the Operating Room but before the start of surgery; and (iii) The Sit-Reps, every 10 minutes for the entire theatre team to maintain situational awareness and allow effective anticipation and planning.
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Background Circulating cell-free DNA (cfDNA) is not found in healthy subjects, but is readily detected after thermal injury and may contribute to the risk of multiple organ failure. The hypothesis was that a postburn reduction in DNase... more
Background Circulating cell-free DNA (cfDNA) is not found in healthy subjects, but is readily detected after thermal injury and may contribute to the risk of multiple organ failure. The hypothesis was that a postburn reduction in DNase protein/enzyme activity could contribute to the increase in cfDNA following thermal injury. Methods Patients with severe burns covering at least 15 per cent of total body surface area were recruited to a prospective cohort study within 24 h of injury. Blood samples were collected from the day of injury for 12 months. Results Analysis of blood samples from 64 patients revealed a significant reduction in DNase activity on days 1–28 after injury, compared with healthy controls. DNase protein levels were not affected, suggesting the presence of an enzyme inhibitor. Further analysis revealed that actin (an inhibitor of DNase) was present in serum samples from patients but not those from controls, and concentrations of the actin scavenging proteins gelsolin...
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Statins, in addition to their lipid-lowering properties, have anti-inflammatory actions. The aim of this review is to evaluate the effect of pre-injury statin use, and statin treatment following injury. MEDLINE, EMBASE, and CENTRAL... more
Statins, in addition to their lipid-lowering properties, have anti-inflammatory actions. The aim of this review is to evaluate the effect of pre-injury statin use, and statin treatment following injury. MEDLINE, EMBASE, and CENTRAL databases were searched to January 2012 for randomised and observational studies of statins in trauma patients in general, and in patients who have suffered traumatic brain injury, burns, and fractures. Of 985 identified citations, 7 (4 observational studies and 3 randomised controlled trials (RCTs)) met the inclusion criteria. Two studies (both observational) were concerned with trauma patients in general, two with patients who had suffered traumatic brain injury (one observational, one RCT), two with burns patients (one observational, one RCT), and one with fracture healing (RCT). Two of the RCTs relied on surrogate outcome measures. The observational studies were deemed to be at high risk of confounding, and the RCTs at high risk of bias. Three of the observational studies suggested improvements in a number of clinical outcomes in patients taking statins prior to injury (mortality, infection, and septic shock in burns patients; mortality in trauma patients in general; mortality in brain injured patients) whereas one, also of trauma patients in general, showed no difference in mortality or infection, and an increased risk of multi-organ failure. Two of three RCTs on statin treatment in burns patients and brain injured patients showed improvements in E-selectin levels and cognitive function. The third, of patients with radial fractures, showed no acceleration in fracture union. In conclusion, there is some evidence that pre-injury statin use and post-injury statin treatment may have a beneficial effect in patients who have suffered general trauma, traumatic brain injury, and burns. However, these studies are at high risk of confounding and bias, and should be regarded as 'hypothesisgenerating'. A well-designed RCT is required to determine the therapeutic efficacy in improving outcomes in this patient population.
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Aim To develop a militarily relevant complex extremity wounding model. Study Design Controlled laboratory study with New Zealand White Rabbits. Method Phase One: Injury Development. Under general anaesthesia, the flexor carpi ulnaris of... more
Aim To develop a militarily relevant complex extremity wounding model. Study Design Controlled laboratory study with New Zealand White Rabbits. Method Phase One: Injury Development. Under general anaesthesia, the flexor carpi ulnaris of the right forelimb was exposed and high energy, short duration impact delivered via drop test rig. Anaesthesia was maintained for three hours, the animal was recovered and saline soaked gauze and supportive bandaging applied. 48 hrs later, the animal was culled and muscle harvested for histological analysis. Analgesia was administered daily, animals checked by experienced staff at least twice daily and temperatures recorded by subcutaneous transponder. Phase Two: Contamination. Sequential groups of animals had inoculums of 1×102, 1×106 and 1×108/100μl of Staphylococcus aureus administered to the muscle immediately after injury. Animals were recovered as phase one. At 48 hours, animals were culled, muscle harvested and axillary lymph nodes sampled. Quantitative microbiological analysis was performed on the muscle. Results: Six animals given a loading of 0.5kg yielded consistent injury with 20% of the muscle becoming necrotic. Representative of injury from ballistic trauma, this was adopted as standard. Twenty-two subsequent animals were exposed to the injury and inoculated with the challenge doses. 1×106/100μl S.aureus provided the greatest consistency in recovered yield. There were no adverse effects on animal welfare and body temperatures were always within normal limits. Discussion. This model enables a consistent, contaminated soft tissue injury to be delivered in vivo. It will allow the investigation of complex wound management including wound coverage and fracture fixation.
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Trauma transfusion strategies, which incorporate balanced red-cell concentrate (RCC)-to-fresh frozen plasma (FFP) ratios, may be associated with improved survival in massively transfused patients. However, the use of this approach in... more
Trauma transfusion strategies, which incorporate balanced red-cell concentrate (RCC)-to-fresh frozen plasma (FFP) ratios, may be associated with improved survival in massively transfused patients. However, the use of this approach in nonmassively transfused patients has led to concern regarding an increase in acute respiratory distress syndrome (ARDS). The aim of this study was to assess the incidence of ARDS in transfused UK military casualties. All UK military casualties receiving an RCC transfusion within a 16-month period were identified from the UK Trauma Registry, and chest radiographs retrieved. If bilateral infiltrates were present, case notes were retrieved to calculate the PaO2/FIO2 ratio in accordance with the American-European Consensus Conference criteria. Patients were divided into massively transfused (≥ 10 U/24 h) and nonmassively transfused (<10 U/24 h) receiving a high ratio (≥ 0.75) or low (<0.75) RCC:FFP ratio. The primary outcome was the development of ARDS within 7 days of transfusion. Primary blast lung injury was excluded. Of 145 patients identified, 144 had records available for analysis with a median injury severity score of 21. The majority were injured by explosion (76%), and the remainder by gunshot (24%). There were 60 nonmassively transfused patients with 18 in the low and 42 in the high RCC:FFP ratio groups. Of the remaining 80 massively transfused patients, 11 were in the low and 73 were in the high-ratio groups. There was no difference in the incidence of ARDS between low- and high-ratio groups in either nonmassively transfused (22.2% vs. 9.5%; P = 0.232) or massively transfused (18.2% vs. 23.3%; P = 1.000) casualties. There was no statistically significant increase in the incidence of ARDS in UK casualties treated with high, compared with low, ratios of plasma to RCC.