[Assessment method of cognitive load and stress inducer factors of surgeons and anesthetists in the operating room]. / Méthodes d'évaluation de la charge cognitive et des facteurs inducteurs de stress des chirurgiens et anesthésistes au bloc opératoire.

INTRODUCTION: For many years, surgeons and anesthetists have recognized that stress can be present in their daily professional practice. The goal of this study was to identify tools for assessing stress and cognitive load in the operating room. MATERIAL AND METHODS: We conducted a literature review in the PubMed database of scientific articles published on the subject without date limit using the keywords anesthesia, surgery, surgeon, cognitive workload, definition, pathophysiology, physiological measurement, objective, subjective, stress. RESULTS: Nineteen articles were selected, focusing on cardiac surgery, gastrointestinal surgery, vascular surgery and urology. No publications concerning ophthalmology were found through the literature search. The means of measurement found were either subjective, such as questionnaires, or objective, such as the study of heart rate variability (HRV), reaction time, eye movements, electrical conductivity of the skin, biological markers and electroencephalogram. Of all these measurement tools, the NASA-TLX questionnaire, used in four articles, and the HRV study, used in eight articles, appear to be the most widely used and are strongly correlated with stress. CONCLUSION: The articles reviewed use only some of the available tools for assessment of stress and cognitive load. The main objective is to improve the quality of care and the quality of life of caregivers. It would be interesting to develop other methods to identify and better characterize the risk factors that increase stress and cognitive load.

Textile Aging Characterization on New Generations of Explanted Commercial Endoprostheses: A Preliminary Study.

OBJECTIVE/BACKGROUND: The goal of the present study was to assess the aging phenomena on second-generation textile endoprostheses (EPs) through explant analysis and to establish a preliminary classification of observed defects and material damages. METHODS: From January 2011 to June 2016 110 second- and recent-generation EPs were collected as a part of a European collaborative retrieval program. The analysis focused on the first 41 consecutive commercial EPs collected between 2011 and 2014 and made from polyethylene terephthalate. Explants were submitted to a standardized evaluation protocol, which included data recording, eye-naked evaluation, cleaning of organic remnants, and structural analysis under numerical optical microscopy. Observations were reported using a classification based on 15 features evaluating the fabric, the stitches between the fabric and the stents, and the stents. The total surface area of the holes within the fabric was measured. RESULTS: EPs were implanted for thoracic and abdominal procedures in 12 and 29 cases, respectively. The mean ± SD duration of implantation was 34 ± 26 months (range 2 days-8 years). Sixty-four percent of the samples demonstrated at least one defect caused by compression damage potentially related to the insertion of the EP within the delivery system, which promoted holes and tears. Ninety-five percent of all EPs demonstrated at least one type of abrasion on the stitches. The degradation of the stitches and the number of ruptures increased with duration of implantation. Stent degradation was rare and consisted of corrosion and rupture. Cumulated holed surface area increased with time and was measured up to 13.5 mm2. CONCLUSION: Various aging-related phenomena on commercial textile EPs were identified and classified. Main damaging mechanisms were related to compression and abrasion leading to tears and holes in the fabric and rupture of stitches.

[Skeletal muscle ischemia-reperfusion and ischemic conditioning pathophysiology-clinical applications for the vascular surgeon]. / Physiopathologie de l'ischémie-reperfusion et du conditionnement ischémique du muscle squelettique ­ applications cliniques pour le chirurgien vasculaire.

Ischemia-reperfusion, which is characterized by deficient oxygen supply and subsequent restoration of blood flow, can cause irreversible damage to tissue. The vascular surgeon is daily faced with ischemia-reperfusion situations. Indeed, arterial clamping induces ischemia, followed by reperfusion when declamping. Mechanisms underlying ischemia-reperfusion injury are complex and multifactorial. Increases in cellular calcium and reactive oxygen species, initiated during ischemia and then amplified upon reperfusion are thought to be the main mediators of reperfusion injury. Mitochondrial dysfunction also plays an important role. Extensive research has focused on increasing skeletal muscle tolerance to ischemia-reperfusion injury, especially through the use of ischemic conditioning strategies. The purpose of this review is to focus on the cellular responses associated with ischemia-reperfusion, as well as to discuss the effects of ischemic conditioning strategies. This would help the vascular surgeon in daily practice, in order to try to improve surgical outcome in the setting of ischemia-reperfusion.

Intraoperative Pleth Variability Index Is Linked to Delayed Graft Function After Kidney Transplantation.

BACKGROUND: Delayed graft function (DGF) is an early postoperative complication of kidney transplantation (KT) predisposing to acute rejection and lower graft survival. Intraoperative arterial hypotension and hypovolemia are associated with DGF. Central venous pressure (CVP) is used to estimate volemia but its reliability has been criticized. Pleth variability index (PVI) is a hemodynamic parameter predicting fluid responsiveness. The aim of this study was to examine the relationship between intraoperative PVI and CVP values and the occurrence of DGF. METHODS: This was a prospective, noninterventional, observational, single-center study. All consecutive patients with KT from deceased donors were included. Recipients received standard, CVP, and PVI monitoring. Intraoperative hemodynamic parameters were recorded from recipients at 5 time points during KT. RESULTS: Forty patients were enrolled. There was a poor correlation between PVI and CVP values (r2 = 0.003; P = .44). Immediate graft function and DGF patients had similar hemodynamic values during KT, with the exception of PVI values, which were significantly higher in the DGF group. In particular, a PVI >9% before unclamping of the renal artery was the only predictive parameter of DGF in our multivariate analysis (P = .02). CONCLUSIONS: This study suggests that PVI values >9% during KT are associated with the occurrence of DGF.

Five Year Outcomes of Surgical Treatment for Popliteal Artery Entrapment Syndrome.

OBJECTIVE/BACKGROUND: The aim of this study was to evaluate long-term outcomes following surgery for popliteal artery entrapment syndrome. METHODS: A retrospective study of all patients that underwent surgery for popliteal artery entrapment syndrome between January 2003 and December 2009 was performed. Patient demographic data, clinical features, imaging modalities, and surgical management were recorded. The primary outcome was 5 year patency. RESULTS: Eighteen patients (25 limbs) underwent surgery. The mean age at the time of surgical procedure was 35 (median 35 years; range 15-49). Presentation was bilateral in seven patients (39%). Diagnosis was made using various imaging modalities, including position stress test, Duplex ultrasonography, computed tomography angiography, magnetic resonance imaging and conventional angiography. In four limbs the popliteal artery was compressed and undamaged (16%), and treatment consisted of musculo-tendinous division alone. In 16 limbs the popliteal artery was damaged with lesions limited to the popliteal artery (64%) where treatment consisted of venous interposition. In five limbs lesions extended beyond the popliteal artery (20%) and procedures included one below knee femoro-popliteal bypass, three femoro-posterior tibial bypasses, and one popliteo-posterior tibial bypass. Musculo-tendinous division was associated with vascular reconstruction in 19 limbs (90%). Mean follow up was 82 months (median 81 months, range 60-120). Five year patency was 84%. CONCLUSION: Long-term outcomes of surgical procedures performed for popliteal artery entrapment syndrome can be considered satisfactory.

Results of isolated infrapopliteal percutaneous transluminal angioplasty for critical limb ischemia in high-risk diabetic patients.

AIM: Infrapopliteal occlusive arterial lesions mostly characterize diabetic patients arteriopathy. Diabetic patients are prone to multiple comorbidities that make them candidates for low-invasive therapeutic options. The aim of this study was to evaluate the safety of infrapopliteal angioplasty in high-risk diabetic patients. METHODS: We undertook a study (retrospective study of a prospectively collected database) of all infrapopliteal endovascular revascularizations performed for critical limb ischemia in high-risk (≥3 major comorbidities) diabetic patients in our institution between 2008 and 2010. Study end points were safety, technical success rate, healing rate, overall 1-year survival, primary patency, secondary patency and limb salvage rates. RESULTS: A total of 101 high-risk diabetic patients (160 arterial lesions: 94 stenosis and 66 occlusions) underwent infrapopliteal endovascular surgery. No major adverse cardiovascular or cerebrovascular event was recorded within 30 days. Two major adverse limb events (two thromboses requiring major amputation) and seven minor adverse events were recorded. Technical and healing rates were, respectively, 83% and 78%. The 1-year survival, primary patency, secondary patency and limb salvage rates were, respectively, 86%, 67%, 83% and 84%. CONCLUSION: Infrapopliteal angioplasty can be considered as a safe and feasible option for high-risk diabetic patients with critical limb ischemia.

[Contribution of mathematical models and biomechanical properties in predicting the risk of abdominal aortic aneurysm rupture]. / Apport des modèles mathématiques et des études biomécaniques dans la prédiction du risque de rupture des anévrysmes de l'aorte abdominale.

INTRODUCTION: Rupture is the worst outcome of abdominal aortic aneurysm (AAA). The decision to operate should include counterbalancing the risk of aneurysm rupture against the risk of aneurysm repair, within the context of a patient's overall life expectancy. Current surgical guidelines are based on population studies, and important variables are missed in predicting individual risk of rupture. METHODS: In this literature review, we focused on the contribution of biomechanical and mathematical models in predicting risk of AAA rupture. RESULTS: Anatomical features as diameter asymmetry and lack of tortuosity are shown to be anatomical risk factors of rupture. Wall stiffness (due to modifications of elastin and collagen composition) and increased inflammatory response are also factors that affect the structural integrity of the AAA wall. Biomechanical studies showed that wall strength is lower in ruptured than non-ruptured AAA. Intra-luminal thrombus also has a big role to play in the occurrence of rupture. Current mathematical models allow more variables to be included in predicting individual risk of rupture. CONCLUSION: Moving away from using maximal transverse diameter of the AAA as a unique predictive factor and instead including biological, structural and biomechanical variables in predicting individual risk of rupture will be essential in the future and will help gain precision and accuracy in surgical indications.

Gender related Long-term Differences after Open Infrainguinal Surgery for Critical Limb Ischemia.

OBJECTIVE: The role of gender on long-term infrainguinal open surgery outcomes still remains uncertain in critical limb ischemia patients. The aim of this study is to evaluate the gender-specific differences in patient characteristics and long-term clinical outcomes in terms of survival, primary patency and limb salvage among patients undergoing infrainguinal open surgery for CLI. MATERIAL AND METHODS: All consecutive patients undergoing infrainguinal open surgery for critical limb ischemia between 2003 and 2012 were included. Survival, limb salvage and primary patency rates were assessed. Independent outcome determinants were identified by the Cox proportional hazard ratio using age and gender as adjustment factors. RESULTS: 584 patients (269 women and 315 men, mean age 76 and 71 years respectively) underwent 658 infrainguinal open surgery (313 in women and 345 in men). Survival rate at 6 years was lower among women compared to men with 53.5% vs 70.9% (p < 0.001). The same applied to primary patency (35.9% vs 52.4%, p < 0.001) and limb salvage (54.3% vs 81.1%, p < 0.001) at 6 years. Female-gender was an independent factor predicting death (hazard ratio 1.50), thrombosis (hazard ratio 2.37) and limb loss (hazard ratio 7.05) in age and gender-adjusted analysis. CONCLUSION: Gender-related disparity in critical limb ischemia open surgical revascularization outcomes still remains.

Chronic mesenteric ischemia: 20 year experience of open surgical treatment.

OBJECTIVES: Both open surgery (OS) and endovascular surgery (ES) have been proposed for the treatment of symptomatic chronic mesenteric ischaemia (CMI). OS was considered the gold standard but ES is increasingly proposed as the first option. The aim was to report long-term outcomes associated with OS in patients suffering CMI in the modern era in order to help in choose between the two techniques. MATERIALS AND METHODS: A retrospective single centre analysis of all consecutive digestive artery revascularizations performed for CMI between January 2003 and December 2012 was carried out. Primary outcomes were 30 day mortality and morbidity, and secondary outcomes were survival, primary patency (PP), secondary patency (SP), and freedom from digestive symptoms, depending on the completeness of the revascularization performed. RESULTS: Eighty-six revascularizations were performed. Median follow up was 6.9 years (range 0.3-20.0). The 30 day mortality and morbidity rates were respectively 3.5% and 13.9%. Ten year survival was 88% for complete revascularization (CR) and 76% for incomplete revascularization (IR) (p = .54). The PP was 84% at 10 years for CR and 87% respectively for IR (p = .51). The 10 year SP was 92% for CR and 93% for IR (p = .63). Freedom from digestive symptoms was influenced by the completeness of revascularization: 79% for CR versus 65% for IR at 10 years (p = .04). CONCLUSIONS: OS for CMI, especially complete revascularization, provides lasting results despite high morbidity.

A new murine model of sustainable and durable chronic critical limb ischemia fairly mimicking human pathology.

OBJECTIVE: To establish a chronic mouse model of critical limb ischemia (CLI) with in vivo and ex vivo validation, closely mimicking human pathology. METHODS: Swiss mice (n = 28) were submitted to sequential unilateral femoral (day 0) and iliac (day 4) ligatures. Ischemia was confirmed by clinical scores (tissue and functional damages) and methoxyisobutylisonitrile (MIBI) scintigraphies at days 0, 4, 6, 10, 20, and 30. At days 10, 20, and 30, muscle mitochondrial respiration, calcium retention capacity (CRC), and production of reactive oxygen species (ROS) were investigated, together with transcripts of mitochondrial biogenesis and antioxidant enzymes. Histological analysis was also performed. RESULTS: Clinical and functional damage confirmed CLI. MIBI scintigraphies showed hypoperfusion of the ischemic limb, which remained stable until day 30. Mitochondrial respiration was impaired in ischemic muscles compared with controls (Vmax = 7.93 ± 0.99 vs. 10.09 ± 2.87 mmol/L O2/minute/mg dry weight [dw]; p = .01), together with impaired CRC (7.4 ± 1.6 mmol/L minute/mg dw vs. 11.9 ± 0.9 mmol/L minute/mg dw; p < .001) and biogenesis (41% decrease in peroxisome proliferator-activated receptor gamma coactivator [PGC]-1α, 49% decrease in PGC-1ß, and 41% decrease in nuclear respiratory factor-1). Ischemic muscles also demonstrated increased production of ROS under electron paramagnetic resonance (0.084 ± 0.029 vs. 0.051 ± 0.031 mmol/L minute/mg dw; p = .03) and with dihydroethidium staining (3622 ± 604 arbitrary units of fluorescence vs. 1224 ± 324; p < .01), decreased antioxidant enzymes (32% decrease in superoxide dismutase [SOD]1, 41% decrease in SOD2, and 49% decrease in catalase), and myopathic features (wider range in fiber size, rounded shape, centrally located nuclei, and smaller cross-sectional areas). All defects were stable over time. CONCLUSION: Sequential femoral and iliac ligatures closely mimic human functional, clinical, scintigraphic, and skeletal muscle mitochondrial characteristics, and could prove useful for testing therapeutic approaches.

Current optimal morphological evaluation of peripheral arterial diseases.

Imaging plays a central role in the management of peripheral arterial diseases (PAD), emphasized by the continuously increasing use of modern cross-sectional imaging and the corresponding decline of digital subtraction angiography (DSA) in the diagnostic setting. Imaging is sometimes used as a screening tool in high-risk individuals. In symptomatic patients, imaging is mandatory to make an accurate positive diagnosis, grade the severity and the extent of the abnormalities, carefully choose and plan the best therapeutic option and provide adequate follow-up. Non-invasive diagnosis of PAD can be made by Doppler ultrasonography, magnetic resonance angiography (MRA) and computed tomography angiography (CTA). Given the major technological breakouts over the last decade, MRA and especially CTA are nowadays mature and precise enough to properly answer all the questions raised in symptomatic patients. This review article aims at describing state-of-the-art non-invasive imaging of PAD, its involvement in the decision-making for the vascular surgeon and the future trends and developments expected in the coming years.

Remote effects of lower limb ischemia-reperfusion: impaired lung, unchanged liver, and stimulated kidney oxidative capacities.

Remote organ impairments are frequent and increase patient morbidity and mortality after lower limb ischemia-reperfusion (IR). We challenged the hypothesis that lower limb IR might also impair lung, renal, and liver mitochondrial respiration. Two-hour tourniquet-induced ischemia was performed on both hindlimbs, followed by a two-hour reperfusion period in C57BL6 mice. Lungs, liver and kidneys maximal mitochondrial respiration (V(max)), complexes II, III, and IV activity (V(succ)), and complex IV activity (V(TMPD)) were analyzed on isolated mitochondria. Lower limb IR decreased significantly lung V(max) (29.4 ± 3.3 versus 24 ± 3.7 µmol O2/min/g dry weight, resp.; P = 0.042) and tended to reduce V(succ) and V(TMPD). IR did not modify liver but increased kidneys mitochondrial respiration (79.5 ± 19.9 versus 108.6 ± 21.4, P = 0.035, and 126 ± 13.4 versus 142.4 ± 10.4 µmol O2/min/g dry weight for V(max) and V(succ), resp.). Kidneys mitochondrial coupling was increased after IR (6.5 ± 1.3 versus 8.8 ± 1.1, P = 0.008). There were no histological changes in liver and kidneys. Thus, lung mitochondrial dysfunction appears as a new early marker of hindlimb IR injuries in mice. Further studies will be useful to determine whether enhanced kidneys mitochondrial function allows postponing kidney impairment in lower limb IR setting.