Thrombocytopenia after sutureless and standard stented aortic valve replacement: a retrospective analysis of risk factors, clinical course, and early outcome.

OBJECTIVES: Thrombocytopenia following Perceval aortic valve replacement has been described previously with variable outcome. Studies have lacked a robust analysis of platelet fluctuation and factors affecting it. We aimed to statistically describe the trend in thrombocyte variability as compared with conventional aortic valve replacement, and to assess predictors as well as impact on associated outcomes. METHODS: One hundred consecutive patients with first-time Perceval were retrospectively compared to 219 patients after Perimount Magna Ease valve replacement. The primary outcome was the serial thrombocyte count on day 0-6. Generalized estimating equations were used to analyse the data using fixed-effect models: for the effect of the post-operative day on platelet count, and random-effect models estimating both time-variant (platelets) and time in-variant variables (valve type, age, LV function, pre-op platelet level). RESULTS: Perceval patients were older (72 ± 1 vs 68 ± 1 years, p < 0.01) with higher NYHA status (3(2-3) vs 2(1-2), p < 0.001). Mean platelet count in the sutureless group was lowest on day 2 (91.9 ± 31.6 vs 121.7 ± 53.8 × 103 µl-1), and lower on day 4 (97.9 ± 44) and 6 (110.6 ± 61) compared to the conventional group (157.2 ± 60 and 181.7 ± 79) but did not result in a higher number of transfusions, bleeding or longer hospital stay (p > 0.05). Reduced platelet count was a strong predictor of red cell transfusion in the conventional (p = 0.016), but not in the sutureless group (p = 0.457). Age (Coef -1.025, 95%CI-1.649--0.401, p < 0.001) and CPB-time (Coef 0.186, 95%CI-0.371--0.001, p = 0.048) were predictors for lower platelet levels. CONCLUSION: Considering the older patient profile treated with Perceval, postoperative thrombocytopenia does not impact on outcome in terms of transfusions, complications or hospital stay.

Sutureless Biological Aortic Valve Replacement (Su-AVR) in Redo operations: a retrospective real-world experience report of clinical and echocardiographic outcomes.

OBJECTIVE: This retrospective study aimed to compare the outcomes of sutureless aortic valve replacement (su-AVR) and conventional bioprosthetic sutured AVR (cAVR) in high-risk patients undergoing redo surgery. METHODS: A total of 79 patients who underwent redo AVR between 2014 and 2021 were included in the study. Of these, 27 patients underwent su-AVR and 52 underwent cAVR. Patient characteristics and clinical outcomes were analysed using multivariate regression and Kaplan Meier survival test. RESULTS: The groups were similar in terms of age, gender, left ventricular function, and number of previous sternotomies. In cases of isolated AVR, su-AVR had significantly lower cross clamp times than cAVR (71 vs. 86 min, p = 0.03). Postoperatively, 4 cAVR patients required pacemaker compared to zero patients in the su-AVR group. There were no significant differences between the two groups in terms of postoperative complications, intrahospital stay (median 9 days, IQR 7-20), or in-hospital mortality (1 su-AVR; 2 cAVR). The long-term survival rate was similar between the su-AVR (90%) and cAVR (92%) groups (log rank p = 0.8). The transvalvular gradients at follow-up were not affected by the type of valve used, regardless of the valve size (coef 2.68, 95%CI -3.14-8.50, p = 0.36). CONCLUSION: The study suggests that su-AVR is a feasible and safe alternative to cAVR in high-risk patients undergoing redo surgery. The use of su-AVR offers comparable outcomes to cAVR, with reduced cross clamp times and a lower incidence of postoperative pacemaker requirement in isolated AVR cases. The results of this study contribute to the growing body of evidence supporting the use of su-AVR in high-risk patients, highlighting its feasibility and safety in redo surgeries.

Destructive Aorto-Mitral Endocarditis: Two Valves for One Annulus.

Surgery for endocarditis of the aorto-mitral continuity can be a challenge in case of extensive tissue destruction. We report two cases of a modified monobloc reconstruction of the aortic and mitral valves and of the aorto-mitral fibrous body. Two valve bioprostheses were sutured to each other and implanted as a composite graft. A pericardial patch sutured to the valves was employed to reconstruct both the noncoronary sinus and the left atrial roof. This technical adjustment allows adaptation to variable anatomical conditions in these particularly difficult cases.

Destructive Aorto-Mitral Endocarditis: Two Valves for One Annulus

Abstract Surgery for endocarditis of the aorto-mitral continuity can be a challenge in case of extensive tissue destruction. We report two cases of a modified monobloc reconstruction of the aortic and mitral valves and of the aorto-mitral fibrous body. Two valve bioprostheses were sutured to each other and implanted as a composite graft. A pericardial patch sutured to the valves was employed to reconstruct both the noncoronary sinus and the left atrial roof. This technical adjustment allows adaptation to variable anatomical conditions in these particularly difficult cases.

Predicting local material thickness from steady-state ultrasonic wavefield measurements using a convolutional neural network.

Acoustic steady-state excitation spatial spectroscopy (ASSESS) is a full-field, ultrasonic non-destructive evaluation (NDE) technique used to locate and characterize defects in plate-like structures. ASSESS generates a steady-state, single-tone ultrasonic excitation in a structure and a scanning laser Doppler Vibrometer (LDV) measures the resulting full-field surface velocity response. Traditional processing techniques for ASSESS data rely on wavenumber domain analysis. This paper presents the alternative use of a convolutional neural network (CNN), trained using simulated ASSESS data, to predict the local plate thickness at every pixel in the wavefield measurement directly. The defect detection accuracy of CNN-based thickness predictions are shown to improve for defects of greater size, and for defects with higher thickness reductions. The CNN demonstrates the ability to predict thickness accurately in regions where Lamb wave dispersion relations are complex or unknown, such as near the boundaries of a test specimen, so long as the CNN is trained on data that accounts for these regions. The CNN also shows generalizability to ASSESS experimental data, despite an entirely simulated training dataset.

Ten-year improved survival in patients with multi-vessel coronary disease and poor left ventricular function following surgery: A retrospective cohort study.

OBJECTIVE: Patients with multi-vessel coronary artery disease and poor left ventricular (LV) function (ejection fraction [EF] < 30%) requiring revascularization are considered 'high-risk'. Limited long-term survival data exists comparing percutaneous coronary intervention (PCI) with second-generation drug-eluting stents (DES) versus surgery for this cohort of patients. METHODS: We retrospectively reviewed our data for 321 patients with EF < 30% who underwent multi-vessel revascularization from January 2005 to December 2015 using Cox regression analyses and inverse probability treatment weighted (IPTW) methods. We stratified patients that underwent surgical revascularization into on-pump coronary artery bypass grafting (CABG) and off-pump CABG and analyzed all-cause mortality at 10 years compared to PCI. RESULTS: 214 patients underwent CABG (n [on-pump CABG] = 94; n [off-pump CABG] = 120) and 107 patients had PCI with second generation DES. PCI with DES had higher 10-year mortality compared with on-pump CABG (Hazard ratio [HR] = 1.86, 95% confidence interval [CI] = 1.46-2.42; p < 0.001) and off-pump CABG (HR = 2.32, 95% CI = 1.75-3.15; p < 0.001). This was confirmed in IPTW analyses. When adjusting for both measured and unmeasured factors using instrumental variable analyses, PCI with DES had higher 10-year mortality compared with on-pump CABG (Δ = 13.5, 95% CI = 3.2-24.5; p = 0.012) and off-pump CABG (Δ = 16.1, 95% CI = 5.9-25.8; p < 0.001). CONCLUSION: Surgical revascularization, preferably off-pump CABG, results in better long-term survival compared with PCI using second generation DES for patients with multi-vessel coronary artery disease and poor left ventricular function. Randomized controlled trials in this patient group should be undertaken.

Coronary artery bypass confers intermediate-term survival benefit over percutaneous coronary intervention with new-generation stents in real-world patients with multivessel coronary artery disease, including left main disease: a retrospective analysis of 6383 patients.

OBJECTIVES: The intermediate-term all-cause mortality rate of real-world patients with multivessel disease (MVD) treated with percutaneous coronary intervention (PCI) with new-generation drug-eluting stents or coronary artery bypass grafting (CABG) remains unknown. We sought to compare the intermediate-term all-cause mortality rates of real-world patients with MVD including left main stem disease, treated with CABG or PCI. METHODS: All consecutive all-comer patients with MVD undergoing CABG or PCI with second/third generation drug-eluting stents from 2007 to 2015 in Harefield Hospital, UK were included in this study. The revascularization modality was based on heart team discussions. Primary outcome was all-cause mortality. Mean follow-up of the study was 3.3 years. Cox regression analysis and propensity matching were used. RESULTS: Of 6383 patients with MVD, 4230 underwent CABG, whereas 2153 had PCI with new-generation stents. In the CABG group, the mean age was 66.4 ± 10 years, whereas in the PCI group it was 65.3 ± 12.1 years (P < 0.001). Fewer female patients with MVD were treated with CABG than were treated with PCI (18.5% vs 20.5%; P = 0.026). There was a higher 5-year estimated survival rate among patients having CABG (88% vs 78.3%; Plog-rank < 0.001). The adjusted hazard ratio (HR) for PCI over CABG was 1.74 [95% confidence interval (CI) 1.41-2.16; P < 0.001]. A total of 653 patients having CABG and 653 having PCI were included in the propensity-matched groups. At mean follow-up, PCI was associated with a higher adjusted HR for all-cause mortality (2.18, 95% CI 1.54-3.1; P < 0.001). CONCLUSIONS: In this contemporary cohort of real-world patients with MVD, CABG was associated with increased intermediate-term survival compared to PCI with new-generation drug-eluting stents.

A Simple and Effective Technique for Anatomical Approximation of the Upper Pericardium Using Hemostatic Clips.

Closure of the pericardium is important to protect bypass grafts, the great vessels, and the heart from injury due to sternal dehiscence. Furthermore, it is reported to reduce the formation of pericardial adhesions and thus facilitate entry into the chest at resternotomy. We here describe a simple, reproducible, and effective technique for tension-free approximation of the upper pericardium by applying small hemostatic clips to the preserved thymic fascia overlying the pericardium.

Does surgery improve prognosis in patients with small-cell lung carcinoma?

A best evidence topic was written according to a structured protocol, asking 'does surgery improve prognosis in patients with small-cell lung carcinoma (SCLC)?' One hundred and thirteen papers were identified, of which the nine papers best able to answer the question were selected and the details of each tabulated. The prohibitive attitude of clinicians toward surgery in SCLC has prevailed since the 1960s, informed by a prospective randomized trial in which 144 patients were assigned to surgical treatment or to radical radiotherapy. Surgery conferred no survival benefit when compared with radical radiotherapy as assessed at 6 monthly intervals up to 10 years post-treatment. Patients with metastatic disease were excluded; however, diagnostic advances subsequent to these trials justify a re-evaluation of the issue, given the greater degree of accuracy with which sub-groups of patients who might benefit from surgery can now be defined. Only one further prospective, randomized trial features in the literature. This study also discerned that no survival benefit was accrued by adding surgery to chemotherapy. However, this study only included patients who responded to an initial course of chemotherapy and also excluded patients with peripheral nodules only. Subsequent investigators have asserted the value of surgery in SCLC. A retrospective case-control study found that surgery significantly improved median survival in patients with stage I disease when compared with patients undergoing medical therapy. One British centre reported survival rates of 52% at 5 years amongst patients undergoing resection and nodal dissection for stage II-IIIA disease. In a retrospective analysis of the Norwegian cancer database, 5-year survival for patients with stage I undergoing surgery was 44.9%, as opposed to 11.3% amongst those treated medically. This finding was echoed in the analysis of the surveillance epidemiology and end results database in the USA, which found improved median survival amongst patients undergoing surgery for limited SCLC. Prospective studies of carefully selected patients have documented good median survival in patients whose tumour was completely resected. We conclude that surgery for early-stage SCLC improves prognosis as part of a multi-modality approach. This echoes the advice of the 2011 national institute of health and clinical excellence guidelines regarding surgery in SCLC.

Is heparin needed for patients with an intra-aortic balloon pump?

We addressed the question of whether or not the currently available evidence base supports heparinization in the context of a patient requiring cardiovascular support with an intra-aortic balloon pump (IABP). A best evidence topic was written according to a previously defined structured protocol. A literature search returned 443 papers, 3 of which were deemed relevant. Jiang et al. randomized 153 patients requiring IABP to heparin or no heparin, matched for age, sex and comorbidities. There was no significant difference in limb ischaemia; however, incidence of bleeding was significantly increased in the heparinized group (14.1 vs 2.4%). One cohort study compared two management strategies of IABP in which patients either received heparin universally or selectively with heparin only given for certain pre-defined indications. They reported increased bleeding with universal heparinization (39.2 vs 31.8%) but similar other complication rates. Another cohort study in which patients with IABP were initially treated with glycoprotein IIb/IIIa antagonists only, reported bleeding and ischaemia rates within accepted ranges for heparinized patients. The use of anticoagulation with IABP is intended to reduce the risk of thrombus, thromboembolus or limb ischaemia whilst generating an increased risk of bleeding as a side-effect. The aforementioned studies demonstrate that omitting or implementing a selective use strategy of heparinization during IABP counterpulsation can significantly decrease the incidence of bleeding without an increase in ischaemic events. One study also performed angiography prior to IABP insertion on some of their patients, selecting the less diseased side to insert the IABP. Current evidence on this topic is sparse, especially as relates to patients in the context of cardiothoracic surgery. Just one study specifically looked at surgical patients. However, the existing data suggest that it is safe to omit heparinization when using IABP counterpulsation. The decision to heparinize should be weighed in the context of other indications or contraindications rather than being an automatic response to the use of IABP.

Surgery and tuberculosis.

PURPOSE OF REVIEW: Tuberculosis (TB) remains a global emergency and continues to kill 1.7 million people globally each year. In the UK, figures for TB are increasing especially in urban areas. There have been advances in imaging techniques as well as increasingly invasive medical interventions in both the diagnosis and treatment of this complex disease. Surgery continues to play an evolving and more challenging role in TB management as minimally invasive procedures can be increasingly used in diagnosis and treatment. Open surgical procedures continue to prove an important adjunct in the management of multidrug-resistant TB (MDR-TB) and the complications of TB. RECENT FINDINGS: Since the peak of surgical treatment for TB in the 1950s, surgery is currently mainly reserved for 'difficult-to-diagnose' or indeed 'difficult-to-treat' cases of TB. Improved diagnostics, medical imaging and invasive medical interventions have all enabled alternatives to early surgical intervention. As improving minimally invasive surgical techniques provide diagnostic and treatment options, older methods of surgically managing complex TB have been revisited. To date most of the studies are retrospective and observatory but large studies and meta-analyses are showing the continued role surgery has to play in the treatment of TB. SUMMARY: This review will focus on new diagnostic imaging techniques and medical interventions which may become increasingly available in both developing countries and in the Western world. It will also highlight the continued role of minimally invasive video-assisted thoracoscopic surgery as well as open surgery in managing TB and MDR-TB.

Tissue-engineered vascular graft remodeling in a growing lamb model: expression of matrix metalloproteinases.

OBJECTIVES: We have previously demonstrated the functionality and growth of autologous, living, tissue-engineered vascular grafts (TEVGs) in long-term animal studies. These grafts showed substantial in vivo tissue remodeling and approximation to native arterial wall characteristics. Based on this, in vitro and in vivo matrix metalloproteinase (MMP) activity of TEVGs is investigated as a key marker of matrix remodeling. METHODS: TEVGs fabricated from biodegradable scaffolds (polyglycolic-acid/poly-4-hydroxybutyrate, PGA/P4HB) seeded with autologous vascular cells were cultured in static and dynamic in vitro conditions. Thereafter, TEVGs were implanted as pulmonary artery replacements in lambs and followed up for 2 years. Gelatin gel zymography to detect MMP-2 and -9 was performed and collagen content quantified (n=5). Latent (pro) and active MMP-2 and -9 were detected. RESULTS: Comparable levels of active MMP-9 and pro-MMP-2 were detected in static and dynamic culture. Higher levels of active MMP-2 were detected in dynamic cultures. Expression of MMP-2 and -9 was minimal in native grafts but was increased in implanted TEVG. Pro-MMP-9 was expressed 20 weeks post implantation and persisted up to 80 weeks post implantation. Collagen content in vitro was increased in dynamically conditioned TEVG as compared with static constructs and was increased in vivo compared with the corresponding native pulmonary artery. CONCLUSIONS: MMPs are up-regulated in vitro by dynamic culture conditions and could contribute to increased matrix remodeling, native analogous tissue formation and functional growth of TEVGs in vivo. Monitoring of MMP activity, for example, by molecular imaging techniques, may enable the non-invasive assessment of functional tissue quality in future clinical tissue-engineering applications.

Are there any good treatments for keloid scarring after sternotomy?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: in patients with hypertrophic and keloid scarring of the sternotomy wound, is surgical excision with or without adjuvant treatment of any benefit in reducing the size of the scar? Altogether, more than 15 papers were found using the reported search, of which nine represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. One of the studies showed no difference between surgery and adjunctive triamcinolone or colchicine. One study showed that incomplete excision resulted in higher recurrence rates. Postoperative radiation was found to be useful in two of the studies, although one study showed that it was not useful. One randomized control trial showed improvement after laser compared to no treatment. Two other trials showed no difference between laser, silicone gel, intralesional steroid or 5-fluorouracil. One trial showed that perioperative systemic steroid application gave rise to no improvement but in fact worsened scar formation. We conclude that small keloids can be treated radically by surgery with adjuvant therapy (radiation or corticosteroid injections) or by non-surgical therapy (corticosteroid injections, laser and anti-tumour/immunosuppressive agents, such as 5-fluorouracil). Large and multiple keloids are difficult to treat radically and are currently only treatable by multimodal therapies that aim to relieve symptoms.

Red to far-red ratio correction in plant growth chambers - growth responses and influence of thermal load on garden pea.

Plant growth chambers are commonly used to minimize environmental variation but the light sources used vary considerably from natural light and from each other. Incandescent globes are often used to add more far-red light, with the aim of producing a more natural red to far-red ratio (R:FR), but also add to thermal load. High-intensity discharge lamps are often used to produce higher irradiances, more akin to natural light, but the thermal implications are rarely considered because air temperature is controlled. This paper examines the spectral properties and thermal implications of growth chamber light sources and takes a whole-plant physiology approach, by examining growth responses of a photoperiodic pea line (Pisum sativum L. cv. Torsdag) in the same growth chamber type under different light sources - in essence using plants to study the controlled environments rather than vice-versa. High R:FR delayed flowering and inhibited internode extension in pea. However, the addition of far-red-rich incandescent globes in the proportions provided in the growth chambers (400-500 W) did little to reduce R:FR, did not induce earlier flowering and actually further inhibited internode length. Leaflet size and yield were significantly reduced. While air temperature was maintained at 20 degrees C in all experiments, radiant temperature was significantly higher under high irradiance and/or with incandescent added, and soil temperatures were elevated. Growth responses under these lights were similar to the effect caused by elevating the air temperature. An alternative method of controlling R:FR, without thermal load implications, using light-emitting diodes is described.

Differential induction of glutathione transferases and glucosyltransferases in wheat, maize and Arabidopsis thaliana by herbicide safeners.

By learning lessons from weed science we have adopted three approaches to make plants more effective in phytoremediation: (1) The application of functional genomics to identify key components involved in the detoxification of, or tolerance to, xenobiotics for use in subsequent genetic engineering/breeding programmes. (2) The rational metabolic engineering of plants through the use of forced evolution of protective enzymes, or alternatively transgenesis of detoxification pathways. (3) The use of chemical treatments which protect plants from herbicide injury. In this paper we examine the regulation of the xenome by herbicide safeners, which are chemicals widely used in crop protection due to their ability to enhance herbicide selectivity in cereals. We demonstrate that these chemicals act to enhance two major groups of phase 2 detoxification enzymes, notably the glutathione transferases and glucosyltransferases, in both cereals and the model plant Arabidopsis thaliana, with the safeners acting in a chemical- and species-specific manner. Our results demonstrate that by choosing the right combination of safener and plant it should be possible to enhance the tolerance of diverse plants to a wide range of xenobiotics including pollutants.