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The development of small-diameter vascular grafts requires testing in large animal models before advancing to clinical trials. Vascular graft interposition implantation in sheep carotid arteries (CAs) is the most widely used model, but ovine CAs are prone to severe spasm following surgical manipulation, potentially impairing graft performance assessment. There is a paucity in the literature on reducing sheep CA spasm using effective vasodilator therapeutic protocols. In this study, four healthy Merino cross White Suffolk wethers (1-2 years, 52.1 ± 0.8 kg) underwent CT angiography and CA graft surgery. CT angiography using iodinated contrast agent was performed with innominate artery access via the CA or ascending aortic arch access via the femoral artery. Sheep were randomly allocated to then underwent right CA sham surgery or left CA vascular graft implantation. A variety of vasodilators, including papaverine, sodium nitroprusside, verapamil and their combination, were tested for preventing or treating CA spasms intraoperatively. Blood flow was reassessed immediately after CA surgery using CT angiography. The results showed that innominate artery access via the CA for CT angiography in sheep induced pre-surgical CA spasm with reduced arterial flow. Conversely, ascending aortic arch access via the femoral artery for CT angiography did not cause CA spasm and maintained arterial flow. During CA graft surgery, surgical trauma induced CA spasm, which was prevented by localised intraarterial administration of vasodilators papaverine hydrochloride and verapamil prior to significant surgical manipulation.
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Background: Colorectal cancer (CRC) is the fourth most common type of cancer in the United Kingdom and the second leading cause of cancer death. Despite improvements in CRC survival over time, Scotland lags behind its UK and European counterparts. In this study, we carry out an exploratory analysis which aims to provide contemporary, population level evidence on CRC treatment and survival in Scotland. Methods: We conducted a retrospective population-based analysis of adults with incident CRC registered on the Scottish Cancer Registry (Scottish Morbidity Record 06 (SMR06)) between January 2006 and December 2018. The CRC cohort was linked to hospital inpatient (SMR01) and National Records of Scotland (NRS) deaths records allowing a description of their demographic, diagnostic and treatment characteristics. Cox proportional hazards regression models were used to explore the demographic and clinical factors associated with all-cause mortality and CRC specific mortality after adjusting for patient and tumour characteristics among people identified as early-stage and treated with surgery. Results: Overall, 32,691 (73%) and 12,184 (27%) patients had a diagnosis of colon and rectal cancer respectively, of whom 55% and 53% were early-stage and treated with surgery. Five year overall survival (CRC specific survival) within this cohort was 72% (82%) and 76% (84%) for patients with colon and rectal cancer respectively. Cox proportional hazards models revealed significant variation in mortality by sex, area-based deprivation and geographic location. Conclusions: In a Scottish population of patients with early-stage CRC treated with surgery, there was significant variation in risk of death, even after accounting for clinical factors and patient characteristics.
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Neoplasias Colorrectales , Neoplasias del Recto , Adulto , Humanos , Estudios Retrospectivos , Neoplasias Colorrectales/tratamiento farmacológico , Escocia/epidemiología , Resultado del TratamientoRESUMEN
Myocardial infarction is one of the leading causes of death and disability worldwide, and there is an urgent need for novel cardioprotective or regenerative strategies. An essential component of drug development is determining how a novel therapeutic is to be administered. Physiologically relevant large animal models are of critical importance in assessing the feasibility and efficacy of various therapeutic delivery strategies. Due to their similarities to humans in cardiovascular physiology, coronary vascular anatomy, and heart weight to body weight ratio, swine is one of the preferred species in the preclinical evaluation of new therapies for myocardial infarction. The present protocol describes three methods of administering cardioactive therapeutic agents in a porcine model. After percutaneously induced myocardial infarction, female landrace swine received treatment with novel agents through either: (1) thoracotomy and transepicardial injection, (2) catheter-based transendocardial injection, or (3) intravenous infusion via jugular vein osmotic minipump. The procedures employed for each technique are reproducible, resulting in reliable cardioactive drug delivery. These models can be easily adapted to suit individual study designs, and each of these delivery techniques can be used to investigate a variety of possible interventions. Therefore, these methods are a useful tool for translational scientists pursuing novel biological approaches in cardiac repair following myocardial infarction.
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Infarto del Miocardio , Humanos , Porcinos , Femenino , Animales , Infarto del Miocardio/tratamiento farmacológico , Vasos Coronarios , Inyecciones , Sistemas de Liberación de Medicamentos , Corazón , Modelos Animales de EnfermedadRESUMEN
Approximately 95% of patients of any age undergoing contemporary, coronary bypass surgery will receive at least 1 saphenous vein graft (SVG). It is recognized that SVG will develop progressive and accelerated atherosclerosis, resulting in a stenosis, and in occlusion that occurs in 50% by 10 years postoperatively. For arterial conduits, there is little evidence of progressive failure as for SVG. Could avoidance of SVG (total arterial revascularization [TAR]) lead to a different late (>5 year) survival? A literature review of 23 studies (N = 100,314 matched patients) at a mean 8.8 years postoperative found reduced all-cause mortality for TAR (HR: 0.77; 95% CI: 0.71-0.84; P < 0.001). An expanded analysis with a new unpublished data set (N = 63,288 matched patients) was combined with the literature review (N = 127,565). It found reduced all-cause mortality for TAR (HR: 0.78; 95% CI: 0.72-0.85; P < 0.001). Additional Bayesian analysis found a very high probability of a TAR-associated reduction all-cause mortality.
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Puente de Arteria Coronaria , Vena Safena , Humanos , Vena Safena/trasplante , Teorema de Bayes , Resultado del Tratamiento , Puente de Arteria Coronaria/métodos , ArteriasRESUMEN
OBJECTIVES: During mitral valve replacement, the anterior mitral leaflet is usually resected or modified. Anterior leaflet splitting seems the least disruptive modification. Reattachment of the modified leaflet to the annulus reduces the annulopapillary distance. The goal of this study was to quantify the acute effects on left ventricular function of splitting the anterior mitral leaflet and shortening the annulopapillary distance. METHODS: In 6 adult sheep, a wire was placed around the anterior leaflet and exteriorized through the left ventricular wall to enable splitting the leaflet in the beating heart. Releasable snares to reduce annulopapillary distance were likewise positioned and exteriorized. A mechanical mitral prosthesis was inserted to prevent mitral incompetence during external manipulations of the native valve. Instantaneous changes in left ventricular function were recorded before and after shortening the annulopapillary distance, then before and after splitting the anterior leaflet. RESULTS: After splitting the anterior leaflet, preload recruitable stroke work, stroke work, stroke volume, cardiac output, left ventricular end systolic pressure and mean pressure were significantly decreased by 26%, 23%, 12%, 9%, 15% and 11%, respectively. Shortening the annulopapillary distance was associated with significant decreases in the end systolic pressure volume relationship, preload recruitable stroke work, stroke work and left ventricular end systolic pressure by 67%, 33%, 15% and 13%, respectively. Shortening the annulopapillary distance after splitting the leaflet had no significant effect. CONCLUSIONS: Splitting the anterior mitral leaflet acutely impaired left ventricular contractility and haemodynamics in an ovine model. Shortening the annulopapillary distance after leaflet splitting did not further impair left ventricular function.
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Insuficiencia de la Válvula Mitral , Válvula Mitral , Ovinos , Animales , Válvula Mitral/cirugía , Función Ventricular Izquierda , Insuficiencia de la Válvula Mitral/cirugía , Volumen Sistólico , HemodinámicaRESUMEN
Randomized trials of stenting versus surgery for patients with unprotected left main (LM) coronary stenosis have largely shown similar survival between the two interventions. However, patients with LM stenosis represent a heterogeneous group in which subgroups likely to benefit from one therapy more than another are difficult to identify. Increasing coronary disease burden is the most accepted subgrouping for identifying optimal therapy but this can be defined in more detail allowing greater discrimination. Competitive flow reduces bypass graft patency in patients with isolated LM stenosis and complex bifurcation stenoses reduce the effectiveness of coronary stenting. The evidence for LM stenosis subgroupings is presented.
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Enfermedad de la Arteria Coronaria , Estenosis Coronaria , Intervención Coronaria Percutánea , Humanos , Enfermedad de la Arteria Coronaria/cirugía , Constricción Patológica , Resultado del Tratamiento , Estenosis Coronaria/cirugíaRESUMEN
The absence of an accepted gold standard to estimate volume status is an obstacle for optimal management of left ventricular assist devices (LVADs). The applicability of the analogue mean systemic filling pressure (Pmsa) as a surrogate of the mean circulatory pressure to estimate volume status for patients with LVADs has not been investigated. Variability of flows generated by the Impella CP, a temporary LVAD, should have no physiological impact on fluid status. This translational interventional ovine study demonstrated that Pmsa did not change with variable circulatory flows induced by a continuous flow LVAD (the average dynamic increase in Pmsa of 0.20 ± 0.95 mmHg from zero to maximal Impella flow was not significant (p = 0.68)), confirming applicability of the human Pmsa equation for an ovine LVAD model. The study opens new directions for future translational and human investigations of fluid management using Pmsa for patients with temporary LVADs.
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Insuficiencia Cardíaca , Corazón Auxiliar , Humanos , Ovinos , Animales , Insuficiencia Cardíaca/cirugíaRESUMEN
BACKGROUND: Return of gastrointestinal (GI) function is fundamental to patient recovery after colorectal surgery and is required before patients can be discharged from hospital safely. Up to 40% of patients suffer delayed return of GI function after colorectal surgery, causing nausea, vomiting and abdominal discomfort, resulting in longer hospital stay. Small, randomised studies have suggested perioperative intravenous (IV) lidocaine, which has analgesic and anti-inflammatory effects, may accelerate return of GI function after colorectal surgery. The ALLEGRO trial is a pragmatic effectiveness study to assess the benefit of perioperative IV lidocaine in improving return of GI function after elective minimally invasive (laparoscopic or robotic) colorectal surgery. METHODS: United Kingdom (UK) multi-centre double blind placebo-controlled randomised controlled trial in 562 patients undergoing elective minimally invasive colorectal resection. IV lidocaine or placebo will be infused for 6-12 h commencing at the start of surgery as an adjunct to usual analgesic/anaesthetic technique. The primary outcome will be return of GI function. DISCUSSION: A 6-12-h perioperative intravenous infusion of 2% lidocaine is a cheap addition to usual anaesthetic/analgesic practice in elective colorectal surgery with a low incidence of adverse side-effects. If successful in achieving quicker return of gut function for more patients, it would reduce the rate of postoperative ileus and reduce the duration of inpatient recovery, resulting in reduced pain and discomfort with faster recovery and discharge from hospital. Since colorectal surgery is a common procedure undertaken in every acute hospital in the UK, a reduced length of stay and reduced rate of postoperative ileus would accrue significant cost savings for the National Health Service (NHS). TRIAL REGISTRATION: EudraCT Number 2017-003835-12; REC Number 17/WS/0210 the trial was prospectively registered (ISRCTN Number: ISRCTN52352431 ); date of registration 13 June 2018; date of enrolment of first participant 14 August 2018.
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Cirugía Colorrectal , Lidocaína , Anestésicos Locales/efectos adversos , Carbazoles , Humanos , Lidocaína/efectos adversos , Dolor Postoperatorio/diagnóstico , Dolor Postoperatorio/etiología , Dolor Postoperatorio/prevención & control , Medicina Estatal , TriptaminasRESUMEN
Data from animal models is now available to initiate assessment of human safety and feasibility of wide-angle three-dimensional intracardiac echocardiography (3D ICE) to guide point-of-care implantation of percutaneous left ventricular assist devices in critical care settings. Assessment of these combined new technologies could be best achieved within a surgical institution with pre-existing expertise in separate utilization of ICE and Impella.
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COVID-19 , Corazón Auxiliar , Procedimientos Quirúrgicos Torácicos , Animales , Ecocardiografía/métodos , Sistemas de Atención de Punto , Resultado del TratamientoRESUMEN
BACKGROUND: The Versius surgical system, from CMR Surgical, is the first UK-based robotic platform to become commercially available. This is a prospective series in accordance with the IDEAL development framework for surgical innovation reporting the clinical implementation and initial experience using this robotic platform. METHODS: Patients with colorectal cancer were included. Exclusion criteria included T4 tumours, ultra-low rectal cancer and severe comorbidity (American Society of Anesthesiologists grade ≥ 3). Institutional ethical approval was obtained, and patients were counselled preoperatively with informed consent. Patients underwent colorectal resection using the Versius surgical system. Procedures were anticipated as hybrid operations (laparoscopic/robotic) consistent with a proof of concept/technical feasibility study. RESULTS: Main outcome measures included operative time, complication rates and pathological results. Thirty-two patients (15 men) underwent colorectal cancer resections. The mean age was 68 years (27-85 years). Estimated blood loss was 150 ml; range <100 to <500 ml. For right hemicolectomy, the average operative time was 221 min (183-323 min). The average console time was 111 min (64-213 min). For robotic anterior resection, the total operative time was on average 319 min (222-408 min) with an average console time of 204 min (85-242 min). Eight patients experienced Grade II morbidities (22%) with no serious morbidities and no mortalities. Mean return to bowel function was 2.9 days (1-6 days). The average length of stay was 5.3 days with a median of 4 days (2-20 days). All resections were R0 with an average lymph node yield of 20 nodes (8-46 nodes). CONCLUSION: Our initial experience with Versius demonstrates its safe adoption and implementation for colorectal resections.
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Laparoscopía , Neoplasias del Recto , Procedimientos Quirúrgicos Robotizados , Anciano , Colectomía , Humanos , Masculino , Estudios Prospectivos , Neoplasias del Recto/cirugía , Resultado del TratamientoRESUMEN
Objectives: Transcatheter mitral valve prostheses are designed to capture the anterior leaflet and surgical techniques designed to fully preserve the subvalvular apparatus at prosthetic valve insertion both serve to shorten the anterior mitral leaflet height, thus effectively incorporating it into the anterior annulus. This study quantifies the acute effects of incorporating the anterior mitral leaflet into the annulus on left ventricular function. Methods: Fourteen adult sheep (weight, 48.7 ± 6.2 kg) underwent a mechanical mitral valve insertion on normothermic beating-heart cardiopulmonary bypass, with full retention of the native mitral valve but with placement of exteriorized releasable snares around the anterior mitral leaflet. Continuous measurements of left ventricular mechano-energetics were recorded throughout, alternating incorporating and releasing of the anterior mitral leaflet to the mitral annulus. Echocardiography confirmed the incorporation into the annulus and release. Results: The independent indices of left ventricular contractility (ie, end systolic pressure volume relationship and preload recruitable stroke work) were both significantly impaired when the anterior mitral leaflet was incorporated to the annulus and restored after release, as were the hemodynamic parameters: cardiac output, stroke volume, stroke work, and left ventricular pressure decreased by 15%, 17%, 23%, and 11%, respectively. Echocardiography demonstrated increased sphericity of the left ventricle during anterior mitral leaflet incorporation. Conclusions: Incorporating the anterior mitral leaflet to the anterior annulus adversely affected left ventricular contractility, caused distortion of the left ventricle in the form of increased sphericity, and impaired hemodynamic parameters in normal ovine hearts.
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Background: The anterior mitral leaflet (AML) contributes to left ventricular (LV) function but is normally excised at the time of a bioprosthetic valve insertion. This study aimed to investigate methods of safely retaining the AML at the time of mitral valve replacement. Methods: Five adult sheep (57 ± 3.8 kg) each underwent 3 insertions of a bioprosthetic mitral valve (asymmetric interstrut sectors) alternating the wide and narrow interstrut distance under the AML. Each insertion was performed on normothermic beating-heart cardiopulmonary bypass, with full retention of the native valve. After each valve insertion, continuous measurements of LV and aortic pressures were recorded with echocardiographic assessment of mitral valve function. If LV outflow tract obstruction (LVOTO) was not seen on the resumption of normal cardiac output, a bolus of adrenaline was given to precipitate it. Results: Thirteen of 15 valve insertions resulted in LVOTO caused by systolic anterior motion (SAM), independent of valve orientation. The wide interstrut distance subtending the AML was associated with a greater requirement for inotropic stress to precipitate an obstruction and was associated with late systolic rather than holosystolic obstruction. Conclusions: The predisposition to and nature of LVOTO due to SAM were associated with the bioprosthetic valve interstrut distance subtending the fully retained AML and may explain the survival differences in such patients. This model represents an effective method for research into prevention of LVOTO following mitral valve replacement with preservation of the native valve.
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BACKGROUND: Total arterial coronary revascularization for three coronary territory disease can be achieved with a second arterial conduit joined to the left internal mammary artery as a Y graft, by using either a radial artery (RAY) or a second mammary artery (BIMAY). METHODS: Patients undergoing total arterial revascularization for three coronary territory disease were identified from two cardiac surgical databases (in Sydney and Melbourne, Australia) using Society of Thoracic Surgeons-based definitions. BIMAY-treated patients underwent surgery between 1994 and 2009, mostly using an age-limited protocol, whereas RAY-treated patients underwent surgery between 1996 and 2003 without age limits. All-cause mortality data were acquired from the national death registry, and survival was estimated by the Kaplan-Meier method. Propensity score matching was performed using 13 variables. Given the age imbalance between the groups, the primary comparison was performed for age 66 years or younger. RESULTS: Overall, 1896 patients underwent RAY procedures, and 720 patients underwent BIMAY operations. Older age at surgery was the strongest independent predictor of mortality, with a hazard ratio of 2.06, and a 95% confidence interval of 1.93, 2.22 (P < .001). After propensity score matching, we identified 299 pairs of patients 66 years of age or younger with no preoperative or operative differences and similar ages at surgery: RAY 56.4 ± 7.0 years of age vs BIMAY 56.4 ± 6.8 years of age (P = .96). The RAY group had 4.0 ± 0.9 grafts, and the BIMAY group had 3.9 ± 0.9 grafts (P = .814). All-cause mortality was not different, with the proportion surviving at 15 years at 74.9% for the RAY group vs 76.2% for the BIMAY group (P = .211). CONCLUSIONS: Survival was not different between the RAY and BIMAY groups for total arterial revascularization of three coronary territory bypass grafting.
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Enfermedad de la Arteria Coronaria/cirugía , Anastomosis Interna Mamario-Coronaria/métodos , Arteria Radial/trasplante , Anciano , Anciano de 80 o más Años , Australia , Enfermedad de la Arteria Coronaria/mortalidad , Bases de Datos Factuales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Puntaje de Propensión , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
Impella CP is a percutaneously inserted left ventricular assist device indicated for temporary mechanical cardiac support during high risk percutaneous coronary interventions and for cardiogenic shock. The potential application of Impella has become particularly relevant during the current COVID-19 pandemic, for patients with acute severe heart failure complicating viral illness. Standard implantation of the Impella CP is performed under fluoroscopic guidance. Positioning of the Impella CP can be confirmed with transthoracic or transoesophageal echocardiography. We describe an alternative approach to guide intracardiac implantation of the Impella CP using two-dimensional and three-dimensional intracardiac echocardiography. This new technique can be useful in selected groups of patients when fluoroscopy, transthoracic and transoesophageal echocardiography is deemed inapplicable or limited for epidemiological or clinical reasons. Intracardiac three-dimensional echocardiography is a feasible alternative to the traditional techniques for implantation of an Impella CP device but careful consideration must be given to the potential limitations and complications of this technique.
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Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Animales , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/fisiología , Betacoronavirus/aislamiento & purificación , COVID-19 , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/patología , Infecciones por Coronavirus/virología , Modelos Animales de Enfermedad , Ecocardiografía , Femenino , Insuficiencia Cardíaca/complicaciones , Imagenología Tridimensional , Pandemias , Neumonía Viral/complicaciones , Neumonía Viral/patología , Neumonía Viral/virología , Prótesis e Implantes , SARS-CoV-2 , Ovinos , Ultrasonografía DopplerRESUMEN
BACKGROUND: Three-dimensional intracardiac echocardiography (3D ICE) with wide azimuthal elevation is a novel technique performed for assessment of cardiac anatomy and guidance of intracardiac procedures, being able to provide unique views with good spatial and temporal resolution. Complications arising from this invasive procedure and the value of 3D ICE in the detection and diagnosis of acute cardiovascular pathology are not comprehensively described. This case illustrates a previously unreported iatrogenic complication of clot displacement from the intra-vascular sheath upon insertion of a 3D ICE catheter and the value of 3D ICE in immediate diagnosis of clot in transit through the heart with pulmonary embolism. CASE PRESENTATION: We conducted a translational study of 3D ICE with wide azimuthal elevation to guide implantation of a left ventricular assist device (Impella CP®) in eight adult sheep. A large-bore 14 Fr central venous sheath was used to enable right atrial and right ventricular access for the intracardiac catheter. Insertion of the 3D ICE catheter was accompanied by a sudden severe cardiorespiratory deterioration in one animal. 3D ICE revealed a large highly mobile mass within the right heart chambers, determined to be a clot-in-transit. The diagnosis of pulmonary clot embolism resulting from the retrograde blood entry into the large-bore sheath introducer, rapid clot formation and consequent displacement into venous circulation by the ICE catheter was made. The sheep survived this life-threatening event following institution of cardiovascular support allowing completion of the primary research protocol. CONCLUSION: This report serves as a serious warning to the researchers and clinicians utilizing long large-bore sheath introducers for 3D ICE and illustrates the value of 3D ICE in detecting clot-in-transit within right heart chambers.
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Trombosis Coronaria/diagnóstico por imagen , Ecocardiografía Tridimensional/métodos , Embolia Pulmonar/diagnóstico por imagen , Animales , Modelos Animales de Enfermedad , Femenino , Oveja DomésticaRESUMEN
The mean systemic filling pressure (MSFP) represents an interaction between intravascular volume and global cardiovascular compliance (GCC). Intravascular volume expansion using fluid resuscitation is the most frequent intervention in intensive care and emergency medicine for patients in shock and with haemodynamic compromise. The relationship between dynamic changes in MSFP, GCC and left ventricular compliance is unknown. We conducted prospective interventional pilot study following euthanasia in post cardiotomy adult sheep, investigating the relationships between changes in MSFP induced by rapid intravascular filling with fluids, global cardiovascular compliance and left ventricular compliance. This pilot investigation suggested a robust correlation between a gradual increase in the intravascular stressed volume from 0 to 40 ml/kg and the MSFP r = 0.708 95% CI 0.435 to 0.862, making feasible future prospective interventional studies. Based on the statistical modelling from the pilot results, we expect to identify a strong correlation of 0.71 ± 0.1 (95% CI) between the MSFP and the stressed intravascular volume in a future study.