Understanding the health system utilisation and reasons for avoidable mortality after fatal injury within a Three-Delays framework in Karonga, Northern Malawi: a retrospective analysis of verbal autopsy data.

OBJECTIVES: To use verbal autopsy (VA) data to understand health system utilisation and the potential avoidability associated with fatal injury. Then to categorise any evident barriers driving avoidable delays to care within a Three-Delays framework that considers delays to seeking (Delay 1), reaching (Delay 2) or receiving (Delay 3) quality injury care. DESIGN: Retrospective analysis of existing VA data routinely collected by a demographic surveillance site. SETTING: Karonga Health and Demographic Surveillance Site (HDSS) population, Northern Malawi. PARTICIPANTS: Fatally injured members of the HDSS. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the proportion of fatal injury deaths that were potentially avoidable. Secondary outcomes were the delay stage and corresponding barriers associated with avoidable deaths and the health system utilisation for fatal injuries within the health system. RESULTS: Of the 252 deaths due to external causes, 185 injury-related deaths were analysed. Deaths were predominantly among young males (median age 30, IQR 11-48), 71.9% (133/185). 35.1% (65/185) were assessed as potentially avoidable. Delay 1 was implicated in 30.8% (20/65) of potentially avoidable deaths, Delay 2 in 61.5% (40/65) and Delay 3 in 75.4% (49/65). Within Delay 1, 'healthcare literacy' was most commonly implicated barrier in 75% (15/20). Within Delay 2, 'communication' and 'prehospital care' were the most commonly implicated in 92.5% (37/40). Within Delay 3, 'physical resources' were most commonly implicated, 85.7% (42/49). CONCLUSIONS: VA is feasible for studying pathways to care and health system responsiveness in avoidable deaths following injury and ascertaining the delays that contribute to deaths. A large proportion of injury deaths were avoidable, and we have identified several barriers as potential targets for intervention. Refining and integrating VA with other health system assessment methods is likely necessary to holistically understand an injury care health system.

Novel application of multi-facility process map analysis for rapid injury care health system assessment in Northern Malawi.

OBJECTIVES: We used the process mapping method and Three Delays framework, to identify and visually represent the relationship between critical actions, decisions and barriers to access to care following injury in the Karonga health system, Northern Malawi. DESIGN: Facilitated group process mapping workshops with summary process mapping synthesis. SETTING: Process mapping workshops took place in 11 identified health system facilities (one per facility) providing injury care for a population in Karonga, Northern Malawi. PARTICIPANTS: Fifty-four healthcare workers from various cadres took part. RESULTS: An overall injury health system summary map was created using those categories of action, decision and barrier that were sometimes or frequently reported. This provided a visual summary of the process following injury within the health system. For Delay 1 (seeking care) four barriers were most commonly described (by 8 of 11 facilities) these were 'cultural norms', 'healthcare literacy', 'traditional healers' and 'police processes'. For Delay 2 (reaching care) the barrier most frequently described was 'transport'-a lack of timely affordable emergency transport (formal or informal) described by all 11 facilities. For Delay 3 (receiving quality care) the most commonly reported barrier was that of 'physical resources' (9 of 11 facilities). CONCLUSIONS: We found our novel approach combining several process mapping exercises to produce a summary map to be highly suited to rapid health system assessment identifying barriers to injury care, within a Three Delays framework. We commend the approach to others wishing to conduct rapid health system assessments in similar contexts.

Access to care following injury in Northern Malawi, a comparison of travel time estimates between Geographic Information System and community household reports.

INTRODUCTION: Injuries disproportionately impact low- and middle-income countries like Malawi. The Lancet Commission on Global Surgery's indicators include the population proportion accessing laparotomy and open fracture care, key trauma interventions, within two hours. The "Golden Hour" for receiving facility-based resuscitation also guides injury care system strengthening. Firstly, we estimated the proportion of the local population able to reach primary, secondary and tertiary facility care within two and one hours using Geographic Information System (GIS) analysis. Secondly, we compared community household-reported with GIS-estimated travel time. METHODS: Using information from a Health and Demographic Surveillance Site (Karonga, Malawi) on road network, facility location, and local staff-estimated travel speeds, we used a GIS-generated friction surface to calculate the shortest travel time from all households to each facility serving the population. We surveyed community households who reported travel time to their preferred, closest, government secondary and tertiary facilities. For recently injured community members, time to reach facility care was recorded. To assess the relationship between community household-reported travel time and GIS-estimated travel time, we used linear regression to generate a proportionality constant. To assess associations and agreement between injured patient-reported and GIS-estimated travel time, we used Kendall rank and Cohen's kappa tests. RESULTS: Using GIS, we estimated 79.1% of households could reach any secondary facility, 20.5% the government secondary facility, and 0% the government tertiary facility, within two hours. Only 28.2% could reach any secondary facility within one hour, 0% for the government secondary facility. Community household-reported travel time exceeded GIS-estimated travel time. The proportionality constant was 1.25 (95%CI 1.21-1.30) for the closest facility, 1.28 (95%CI 1.23-1.34) for the preferred facility, 1.45 (95%CI 1.33-1.58) for the government secondary facility, and 2.12 (95%CI 1.84-2.41) for tertiary care. Comparing injured patient-reported with GIS-estimated travel time, the correlation coefficient was 0.25 (SE 0.047) and Cohen's kappa was 0.15 (95%CI 0.078-0.23), suggesting poor agreement. DISCUSSION: Most households couldn't reach government secondary care within recognised thresholds indicating poor temporal access. Since GIS-estimated travel time was shorter than community-reported travel time, the true proportion may be lower still. GIS derived estimates of population emergency care access in similar contexts should be interpreted accordingly.

Survival after traumatic brain injury improves with deployment of neurosurgeons: a comparison of US and UK military treatment facilities during the Iraq and Afghanistan conflicts.

INTRODUCTION: Traumatic brain injury (TBI) is the most common cause of death on the modern battlefield. In recent conflicts in Iraq and Afghanistan, the US typically deployed neurosurgeons to medical treatment facilities (MTFs), while the UK did not. Our aim was to compare the incidence, TBI and treatment in US and UK-led military MTF to ascertain if differences in deployed trauma systems affected outcomes. METHODS: The US and UK Combat Trauma Registries were scrutinised for patients with HI at deployed MTFs between March 2003 and October 2011. Registry datasets were adapted to stratify TBI using the Mayo Classification System for Traumatic Brain Injury Severity. An adjusted multiple logistic regression model was performed using fatality as the binomial dependent variable and treatment in a US-MTF or UK-MTF, surgical decompression, US military casualty and surgery performed by a neurosurgeon as independent variables. RESULTS: 15 031 patients arrived alive at military MTF after TBI. Presence of a neurosurgeon was associated with increased odds of survival in casualties with moderate or severe TBI (p<0.0001, OR 2.71, 95% CI 2.34 to 4.73). High injury severity (Injury Severity Scores 25-75) was significantly associated with a lower survival (OR 4×104, 95% CI 1.61×104 to 110.6×104, p<0.001); however, having a neurosurgeon present still remained significantly positively associated with survival (OR 3.25, 95% CI 2.71 to 3.91, p<0.001). CONCLUSIONS: Presence of neurosurgeons increased the likelihood of survival after TBI. We therefore recommend that the UK should deploy neurosurgeons to forward military MTF whenever possible in line with their US counterparts.

Facial injury management undertaken at US and UK medical treatment facilities during the Iraq and Afghanistan conflicts: a retrospective cohort study.

OBJECTIVES: To perform the first direct comparison of the facial injuries sustained and treatment performed at USA and UK deployed medical treatment facilities (MTFs) in support of the military campaigns in Iraq and Afghanistan. SETTING: The US and UK Joint Theatre Trauma Registries were scrutinised for all patients with facial injuries presenting alive to a UK or US deployed MTF between 1 March 2003 and 31 October 2011. PARTICIPANTS: US and UK military personnel, local police, local military and civilians. PRIMARY AND SECONDARY OUTCOME MEASURES: An adjusted multiple logistic regression model was performed using tracheostomy as the primary dependent outcome variable and treatment in a US MTF, US or UK military, mandible fracture and treatment of mandible fracture as independent secondary variables. RESULTS: Facial injuries were identified in 16 944 casualties, with the most common being those to skin/muscle (64%), bone fractures (36%), inner/middle ear (28%) and intraoral damage (11%). Facial injuries were equally likely to undergo surgery in US MTF as UK MTF (OR: 1.06, 95% CI 0.4603 to 1.142, p=0.6656); however, variations were seen in injury type treated. In US MTF, 692/1452 (48%) of mandible fractures were treated by either open or closed reduction compared with 0/167 (0%) in UK MTF (χ2: 113.6; p≤0.0001). US military casualties who had treatment of their mandible fracture (open reduction and internal fixation or mandibulo-maxillary fixation) were less likely to have had a tracheostomy than those who did not undergo stabilisation of the fractured mandible (OR: 0.61, 95% CI 0.44 to 0.86; p=0.0066). CONCLUSIONS: The capability to surgically treat mandible fractures by open or closed reduction should be considered as an integral component of deployed coalition surgical care in the future.

Management and outcome of 597 wartime penetrating lower extremity arterial injuries from an international military cohort.

OBJECTIVE: Vascular injury is a leading cause of death and disability in military and civilian settings. Most wartime and an increasing amount of civilian vascular trauma arises from penetrating mechanisms of injury due to gunshot or explosion. The objective of this study was to provide a comprehensive examination of penetrating lower extremity arterial injury and to characterize long-term limb salvage and differences related to mechanisms of injury. METHODS: The military trauma registries of the United States and the United Kingdom were analyzed to identify service members who sustained penetrating lower limb arterial injury (2001-2014). Treatment and limb salvage data were studied and comparisons made of patients whose penetrating vascular trauma arose from explosion (group 1) vs gunshot (group 2). Standardized statistical testing was used, with Bonferroni corrections for multiple comparisons. RESULTS: The cohort consisted of 568 combat casualties (mean age, 25.2 years) with 597 injuries (explosion, n = 416; gunshot, n = 181). Group 1 had higher Injury Severity Score (P < .05) and Mangled Extremity Severity Score (P < .0001), required more blood transfusion (P < .05), and had more tibial (P < .01) and popliteal (P < .05) arterial injuries; group 2 had more profunda femoris injuries (P < .05). Initial surgical management for the whole cohort included vein interposition graft (33%), ligation (31%), primary repair with or without patch angioplasty (16%), temporary vascular shunting (15%), and primary amputation (6%). No difference in patency of arterial reconstruction was found between group 1 and group 2, although group 1 had a higher incidence of primary (13% vs 2%; P < .05) and secondary (19% vs 9%; P < .05) amputation. Similarly, longer term freedom from amputation was lower for group 1 than for group 2 (68% vs 89% at 5.5 years; Cox hazard ratio, 0.30; P < .0001), as was physical functioning (36-Item Short Form Health Survey data; mean, 39.80 vs 43.20; P < .05). CONCLUSIONS: The majority of wartime lower extremity arterial injuries result from an explosive mechanism that preferentially affects the tibial vasculature and results in poorer long-term limb salvage compared with those injured with firearms. The mortality associated with immediate limb salvage attempts is low, and delayed amputations occur weeks later, affording the patient involvement in the decision-making and rehabilitation planning. We recommend assertive attempts at vascular repair and limb salvage for service members injured by explosive and gunshot mechanisms.

Graft-implanted, enzyme responsive, tacrolimus-eluting hydrogel enables long-term survival of orthotopic porcine limb vascularized composite allografts: A proof of concept study.

BACKGROUND: Currently, patients receiving vascularized composite allotransplantation (VCA) grafts must take long-term systemic immunosuppressive therapy to prevent immunologic rejection. The morbidity and mortality associated with these medications is the single greatest barrier to more patients being able to receive these life-enhancing transplants. In contrast to solid organs, VCA, exemplified by hand or face transplants, allow visual diagnosis of clinical acute rejection (AR), directed biopsy and targeted graft therapies. Local immunosuppression in VCA could reduce systemic drug exposure and limit adverse effects. This proof of concept study evaluated, in a large animal forelimb VCA model, the efficacy and tolerability of a novel graft-implanted enzyme-responsive, tacrolimus (TAC)-eluting hydrogel platform, in achieving long-term graft survival. METHODS: Orthotopic forelimb VCA were performed in single haplotype mismatched mini-swine. Controls (n = 2) received no treatment. Two groups received TAC hydrogel: high dose (n = 4, 91 mg TAC) and low dose (n = 4, 49 mg TAC). The goal was to find a dose that was tolerable and resulted in long-term graft survival. Limbs were evaluated for clinical and histopathological signs of AR. TAC levels were measured in serial blood and skin tissue samples. Tolerability of the dose was evaluated by monitoring animal feeding behavior and weight. RESULTS: Control limbs underwent Banff Grade IV AR by post-operative day six. Low dose TAC hydrogel treatment resulted in long-term graft survival time to onset of Grade IV AR ranging from 56 days to 93 days. High dose TAC hydrogel also resulted in long-term graft survival (24 to 42 days), but was not well tolerated. CONCLUSION: Graft-implanted TAC-loaded hydrogel delays the onset of Grade IV AR of mismatched porcine forelimb VCA grafts, resulting in long term graft survival and demonstrates dose-dependent tolerability.

Composite Graft Pretreatment With Hydrogen Sulfide Delays the Onset of Acute Rejection.

INTRODUCTION: Vascularized composite allotransplantation can reconstruct devastating tissue loss by replacing like-with-like tissues, most commonly in the form of hand or face transplantation. Unresolved technical and ethical challenges have meant that such transplants remain experimental treatments. The most significant barrier to expansion of this field is the requirement for systemic immunosuppression, its toxicity and effect on longevity.Hydrogen sulfide (H2S) has been shown experimentally to ameliorate the ischemia reperfusion injury associated with composite tissue autotransplantation, which has been linked to acute rejection in solid organ transplantation. In this protocol, a large-animal model was used to evaluate the effect of H2S on acute rejection after composite tissue allotransplantation. MATERIALS AND METHODS: A musculocutaneous flap model in SLA-mismatched swine was used to evaluate acute rejection of allotransplants in 2 groups: control animals (n = 8) and a treatment group in which the allografts were pretreated with hydrogen sulfide (n = 8). Neither group was treated with systemic immunosuppression. Acute rejection was graded clinically and histopathologically by an independent, blinded pathologist. Data were analyzed by t tests with correction for multiple comparisons by the Holm-Sídák method. RESULTS: Clinically, H2S-treated tissue composites showed a delay in the onset of rejection that was statistically significant from postoperative day 6. Histopathologically, this difference between groups was also apparent, although evidence of a difference in groups disappeared beyond day 10. CONCLUSIONS: Targeted hydrogen sulfide treatment of vascularized composite allografts immediately before transplantation can delay acute rejection. This may, in turn, reduce or obviate the requirement for systemic immunosuppression.

Combat vascular injury: Influence of mechanism of injury on outcome.

BACKGROUND: Haemorrhage is the leading cause of death on the battlefield. Seventy percent of injuries are due to explosive mechanisms. Anecdotally, these patients have had poorer outcomes when compared to those with penetrating mechanisms of injury (MOI). We wished to test the hypothesis that outcomes following vascular reconstruction were worse in blast-injured than non blast-injured patients. METHODS: Retrospective cohort study. British and American combat casualties with arterial injuries sustained in Iraq or Afghanistan (2003-2014) were identified from the UK Joint Theatre Trauma Registry (JTTR). Eligibility included explosive or penetrating MOI, with follow-up to UK hospital discharge, or death. Outcomes were mortality, amputation, graft thrombosis, haemorrhage, and infection. Statistical analysis was performed using Pearson Chi-Square test, t-tests, ANOVA or non-parametric equivalent, and survival analyses. RESULTS: One hundred and fifteen patients were included, 80 injured by explosive and 35 by penetrating mechanisms. Evacuation time, ISS, number of arterial injuries, age and gender were comparable between groups. Seventy percent of arterial injuries resulted from an explosive MOI. The explosive injuries group received more blood products (p = 0.008) and suffered more regions injured (p < 0.0001). Early surgical interventions in both were ligation (n = 36, 31%), vein graft (n = 33, 29%) and shunting (n = 9, 8%). Mortality (n = 12, 10%) was similar between groups. Differences in limb salvage rates following explosive (n = 17, 53%) vs penetrating (n = 13, 76.47%) mechanisms approached statistical significance (p = 0.056). Nine (28%) vein grafted patients developed complications. No evidence of a difference in the incidence of vein graft thrombosis was found when comparing explosive with non-explosive cohorts (p = 0.154). CONCLUSIONS: The recorded numbers of vein grafts following combat arterial trauma in are small in the JTTR. No statistically-significant differences in complications, including vein graft thrombosis, were found between cohorts injured by explosive and non-explosive mechanisms.

Regenerative medicine and war: a front-line focus for UK defence.

The recent prolonged conflicts in Iraq and Afghanistan saw the advancement of deployed trauma care to a point never before seen in war. The rapid translation of lessons from combat casualty care research, facilitated by an appetite for risk, contributed to year-on-year improvements in care of the injured. These paradigms, however, can only ever halt the progression of damage. Regenerative medicine approaches, in contrast, hold a truly disruptive potential to go beyond the cessation of damage from blast or ballistic trauma, to stimulate its reversal, and to do so from a very early point following injury. The internationally distributed and, in parts austere environments in which operational medical care is delivered provide an almost unique challenge to the development and translation of regenerative medicine technologies. In parallel, however, an inherent appetite for risk means that Defence will always be an early adopter. In focusing our operational priorities for regenerative medicine, the authors conducted a review of the current research landscape in the UK and abroad and sought wide clinical opinion. Our priorities are all applicable very far forward in the patient care pathway, and are focused on three broad and currently under-researched areas, namely: (a) blood, as an engineered tissue; (b) the mechanobiology of deep tissue loss and mechanobiological approaches to regeneration, and; (c) modification of the endogenous response. In focusing on these areas, we hope to engender the development of regenerative solutions for improved functional recovery from injuries sustained in conflict.

A Porcine Orthotopic Forelimb Vascularized Composite Allotransplantation Model: Technical Considerations and Translational Implications.

BACKGROUND: The restoration of complex tissue deficits with vascularized composite allotransplantation is a paradigm shift in reconstructive surgery. Clinical adoption of vascularized composite allotransplantation is limited by the need for systemic immunosuppression, with associated morbidity and mortality. Small-animal models lack the biological fidelity and preclinical relevance to enable translation of immunologic insights to humans. Large-animal models have been described; however, limitations persist, including the inability of heterotopic models to evaluate functional nerve regeneration, and the sensitivity of primates to toxicity of immunosuppressive drugs. The authors' novel orthotopic porcine limb transplant model has broad applicability and translational relevance to both immunologic and functional outcomes after vascularized composite allotransplantation. METHODS: Recipients underwent amputation at a level corresponding to the mid forearm. Replantation or transplantation of grafts was performed by plate fixation of the radio-ulna, microsurgical repair of brachial artery and median nerve, and extensor and flexor tendon repairs. Viability of replants was monitored clinically and radiologically. Transplants were monitored for clinicopathologic signs of rejection. Animals mobilized freely postoperatively. RESULTS: Replantations remained viable until the endpoint of 14 days. Transplants developed Banff grade 4 acute rejection by postoperative day 7. Doppler sonography and angiography confirmed vascular patency. Serial biopsy specimens of skin and histopathology of replants at endpoint confirmed tissue viability and bone healing. CONCLUSIONS: An orthotopic load-bearing porcine forelimb vascularized composite allotransplantation model was successfully established. Technical, procedural, and logistic considerations were optimized to allow model use for immunologic, bone healing, functional nerve regeneration, and other translational studies.

Surgeon preparedness for mass casualty events: Adapting essential military surgical lessons for the home front.

Military surgeons have gained familiarity and experience with mass casualty events (MCEs) as a matter of routine over the course of the last two conflicts in Afghanistan and Iraq. Over the same period of time, civilian surgeons have increasingly faced complex MCEs on the home front. Our objective is to summarize and adapt these combat surgery lessons to enhance civilian surgeon preparedness for complex MCEs on the home front. The authors describe the unique lessons learned from combat surgery over the course of the wars in Afghanistan and Iraq and adapt these lessons to enhance civilian surgical readiness for a MCE on the home front. Military Damage Control Surgery (mDCS) combines the established concept of clinical DCS (cDCS) with key combat situational awareness factors that enable surgeons to optimally care for multiple, complex patients, from multiple simultaneous events, with limited resources. These additional considerations involve the surgeon's role of care within the deployed trauma system and the battlefield effects. The proposed new concept of mass casualty DCS (mcDCS) similarly combines cDCS decisions with key factors of situational awareness for civilian surgeons faced with complex MCEs to optimize outcomes. The additional considerations for a civilian MCE include the surgeon's role of care within the regional trauma system and the incident effects. Adapting institutionalized lessons from combat surgery to civilian surgical colleagues will enhance national preparedness for complex MCEs on the home front.

Healing of two microarterial anastomoses with diameter mismatch.

BACKGROUND: The use of fascial perforating vessels as recipients for microvascular composite tissue autotransplants has led to vessel diameter discrepancy becoming an increasingly common finding. Little evidence, however, is available to direct the choice of anastomotic technique where a discrepancy exists. We have been studying two methods of anastomosing arteries where a small-to-large discrepancy exists-a 45° section of the smaller vessel, and invaginating the smaller vessel inside the larger. As part of this work, this study examines intimal hyperplasia and healing of the two methods. MATERIALS AND METHODS: A previously described paired Wistar rat femoral axis model was used. Anastomoses were performed, one on each side, and specimens were harvested in groups at 24 h, 1 wk, 6 wk, and 8 mo. Inflammation, necrosis, and fibrosis in each layer of the vessel wall and intimal hyperplasia were each scored by an assessor blinded to the group and anastomotic technique. RESULTS: Significant differences in healing were found. The invagination technique induced less inflammation, and caused less endothelial and medial necrosis than the oblique cut end-to-end method. Intimal hyperplasia was most pronounced at 6 wk, but no evidence of a difference in the severity of intimal hyperplasia between the two methods was found. CONCLUSIONS: The invaginating anastomosis causes less inflammation and less vessel wall necrosis than the oblique end-to-end method in this model. This finding, alongside results from previous work, suggests that this is the better method to deal with a small-to-large microarterial diameter discrepancy in the range 1:1.5 to 1:2.5.

Lack of precision of burn surface area calculation by UK Armed Forces medical personnel.

OBJECTIVE: Accurate determination of the severity of burn is essential for the care of thermally injured patients. We aimed to examine the accuracy and precision of TBSA calculation performed by specialist military burn care providers and non-specialist but experienced military clinicians. METHODS: Using a single case example with photographic montages and a modified Lund and Browder chart, the two cohorts of clinicians were each given 10min to map and calculate the case example TBSA involvement. The accuracy and precision of results from the two cohorts were compared to a set standard %TBSA. RESULTS: The set standard %TBSA involvement was 64.5%. Mean %TBSA mapped by non-specialists (52.53±10.03%) differed significantly from the set standard (p<0.0001). No difference was observed when comparing results from the burn care providers (65.68±10.29%; p=0.622). However, when comparing precision of calculation of TBSA burned, there was no evidence of a difference in heterogeneity of results between the two cohorts (F test, p=0.639; Levene's test, p=0.448). CONCLUSIONS: These results indicate that experienced military burn care providers overall more accurately assess %TBSA burned than relatively inexperienced clinicians. However, results demonstrate a lack of precision in both groups.

A history of vascular and microvascular surgery.

The history of microvascular surgery is intimately linked to that of vascular surgery. Microvascular techniques, developed mainly in China, Japan, Australia, and the United States of America, built on the principles of vascular anastomosis established by pioneers in France, Germany, Italy, and the United States of America. We present a history of the technique here.

Autologous reconstruction of the inguinal ligament using pedicled fascia lata flap: A new technique.

INTRODUCTION: A technique of reconstructing the inguinal ligament using a pedicled fascia lata flap is described. PRESENTATION OF CASE: A 62-year-old man was referred with massive bilateral abdominal wall hernias, following numerous attempts at repair and subsequent recurrences. There was complete absence of the right inguinal ligament. The inguinal ligament was reconstructed using a strip of fascia lata, pedicled on the anterior superior iliac spine. This was transposed to cover the external iliac vessels, and sutured to the pubic tubercle. The musculoaponeurotic abdominal wall was reconstructed with two 20cm×20cm sheets of porcine acellular dermal matrix and an overlying sheet of polypropylene mesh, sutured to the remaining abdominal wall muscles laterally, and to both inguinal ligaments. The cutaneous abdominal wall was closed with an abdominoplasty technique. The reconstruction has remained intact nine months following surgery. DISCUSSION: Complete destruction of the inguinal ligament is rare but can occur following multiple operative procedures or trauma. To date, the only published reports of inguinal ligament reconstruction have been performed using synthetic mesh. The use of autologous tissue should reduce the risk of erosion into the neurovascular bundle, seroma formation, and enhance integration into surrounding tissues. CONCLUSION: This new technique for autologous reconstruction of the inguinal ligament provides a safe alternative to the use of synthetic mesh in the operative armamentarium of plastic and hernia surgeons.

Computational modeling of microarterial anastomoses with size discrepancy (small-to-large).

OBJECTIVE: Among causes of anastomotic failure in microvascular surgery is vessel size mismatch. Where the option of an end-to-side anastomosis is unavailable, an end-to-end construct must be used. Several end-to-end techniques are described to deal with size mismatch. The aim of this study was to numerically model arterial flow patterns and wall shear stresses in four idealized end-to-end anastomoses, where the upstream or recipient artery is smaller. The four techniques modeled were: an invaginating anastomosis; a fish-mouth incision of the smaller vessel; an oblique section of the smaller vessel; and a wedge excision of the larger vessel. MATERIALS AND METHODS: Flow rate in the right femoral artery of a single outbred male Wistar rat was recorded by transit time ultrasound. Initially, upstream vessel diameter in the models was set at 1 mm, and downstream at 2 mm. The wedge technique was further modeled using a shorter wedge, and using a downstream vessel diameter of 3 mm. Walls were deemed noncompliant. Flow was modeled by the finite volume method using the commercially available computational fluid dynamics code Fluent (Fluent Inc., Lebanon, NH; http://www.fluent.com). RESULTS: Ring vortices were seen in the invagination and fish-mouth models and showed similar characteristics, although they were less pronounced in the fish-mouth model. The oblique section model demonstrated complex, spiral, counter-rotating vortices that dissipated downstream. Flow separation was least in the first wedge model, with centralization of flow during high but decelerating flow rate. Shortening the wedge length or increasing the downstream vessel diameter to 3 mm led to flow separation. Wall shear stresses were broadly similar for all constructs. CONCLUSION: Of those modeled, excision of a wedge of the larger vessel proved the best construct. Where a vessel diameter ratio is 1:2, wedge length should be twice the diameter of the larger vessel. A vessel ratio of 1:3 leads to flow separation when using the wedge technique.

Influence of vascular delay on abdominal wall complications in unipedicled TRAM flap breast reconstruction.

Surgically delaying a unipedicled lower abdominal transverse rectus abdominis musculocutaneous (TRAM) flap has been shown to improve flow within the flap. This delay, however, also affects blood supply and drainage of the entire anterior abdominal wall. The purpose of this study was to compare the abdominal complications between surgically delayed and nondelayed TRAM flaps. A retrospective case review of lower abdominal TRAM flap breast reconstructions was performed. A total of 35 patients were included in the study, of whom 15 had undergone delay and 20 had not. The patients were found to be matched by age and body mass index. There was a higher incidence of smokers (past or present) in the delayed series. Despite this, no abdominal flap complications were experienced in those who underwent delay. In the nondelayed series, however, three patients (15%) experienced delayed healing, and two flaps (10%) underwent severe necrosis (p = 0.047, chi-squared test). In the delayed series, one patient (7%) was found to have an abdominal bulge. No hernias were encountered. In contrast, two bulges (10%) and four hernias (20%) were identified in patients in the nonndelayed series (p = 0.6 and 0.09, respectively, chi-squared test). These data suggest that a preliminary delay procedure leads to a reduction in the incidence of abdominal wall complications in unipedicled lower abdominal TRAM flaps.