Background: The vasoactive-ventilation-renal (VVR) score includes pulmonary and renal dysfunctions not previously addressed by the vasoactive inotrope score (VIS) and may be a better predictor of cardiac care unit (CC...Background: The vasoactive-ventilation-renal (VVR) score includes pulmonary and renal dysfunctions not previously addressed by the vasoactive inotrope score (VIS) and may be a better predictor of cardiac care unit (CCU) length of stay (LOS) in patients undergoing re-entry sternotomy (defined as no earlier than 30 days after previous sternotomy) for congenital heart disease (CHD). Methods: Patients undergoing re-entry sternotomy for CHD from August 1, 2009 to June 30, 2016 were studied retrospectively. A total of 96 patients undergoing 133 re-entry procedures were identified. VVR scores were calculated on CCU admission post-procedure (at 0 hour), 24-hour, and 48-hour after admission to the CCU. The response variable was CCU LOS.? Recursive partition analysis identified variables predicting LOS. Results: 133 re-entry sternotomies in 96 patients made up the samples of the database;11 samples were removed due to incomplete data or placement on ECMO. Of the initial 25 features, 5 were removed for near zero variance and 3 categorical features were removed for non-information. Covariance analysis did not demonstrate any significant correlation amongst the remaining features. Initial recursive tree regression using ANOVA, cross validation and conditional predictive p-value (cp) = 0.01 produced 3 trees. The tree with lowest cross validation error was selected. The resulting 2 split trees with ventilator days less than 20 days and VVR score at 48 hours greater than 23 identified three CCU LOS groups with mean CCU LOS of 77.6, 55.1, and 9.5 days. Conclusions: Recursive partition analysis identified ventilator days greater than 20 days and the sub-population VVR at 48 hours as predictive of CCU LOS in patients undergoing re-entry sternotomy for CHD.展开更多
BACKGROUND Obese patients(body mass index≥30 kg/m^(2))undergoing isolated aortic valve replacement(AVR)face increased surgical risks due to comorbidities.Partial upper sternotomy(PUS),a minimally invasive approach,ma...BACKGROUND Obese patients(body mass index≥30 kg/m^(2))undergoing isolated aortic valve replacement(AVR)face increased surgical risks due to comorbidities.Partial upper sternotomy(PUS),a minimally invasive approach,may reduce complications compared to full median sternotomy(FMS).We hypothesize that PUS improves outcomes over FMS in obese patients undergoing AVR.AIM To compare the efficacy and safety of PUS vs FMS in obese patients undergoing isolated AVR.METHODS This systematic review and meta-analysis followed PRISMA guidelines,searching PubMed,EMBASE,and Cochrane databases for observational studies comparing PUS vs FMS in obese patients undergoing AVR.Outcomes were analyzed using odds ratios(OR),mean differences(MD),95%confidence intervals(CI),I^(2)statistic,and Newcastle-Ottawa Scale was used for quality assessment.RESULTS Four observational studies involving 677 patients were analyzed.PUS reduced intensive care unit stay(MD-2.67 days,95%CI:-4.43 to-0.90,P=0.003,I^(2)=78%)but increased cardiopulmonary bypass time(MD 5.62 minutes,95%CI:-0.36 to 11.59,I^(2)=55%).No differences were observed in renal failure(OR 1.13,95%CI:0.63-2.94,I^(2)=0%),atrial fibrillation(OR 0.81,95%CI:0.43-1.54,I^(2)=30%),reexploration(OR 1.09,95%CI:0.48-2.47,I^(2)=0%),postoperative bleeding(OR 1.48,95%CI:0.53-4.15,I^(2)=60%),wound infection(OR 1.23,95%CI:0.70-2.14,I^(2)=0%),hospital stay(MD 0.51 days,95%CI:-4.13 to 5.15,I^(2)=90%),or cross-clamp time(MD 4.03 minutes,95%CI:-0.75 to 8.80,I^(2)=50%).CONCLUSION PUS is safe and effective for obese patients undergoing AVR,reducing intensive care unit stay and enhancing recovery,provided surgical expertise is available.展开更多
BACKGROUND Cardiac myxoma,a benign intracardiac tumor,is traditionally excised via conven-tional sternotomy,which is invasive and associated with longer recovery times.Minimally invasive robotic surgery has emerged as...BACKGROUND Cardiac myxoma,a benign intracardiac tumor,is traditionally excised via conven-tional sternotomy,which is invasive and associated with longer recovery times.Minimally invasive robotic surgery has emerged as a potential alternative,offe-ring reduced trauma and faster recovery.This meta-analysis compares the effi-cacy and safety of robotic surgery vs conventional sternotomy for cardiac myxo-ma excision.We hypothesized that robotic surgery would provide comparable safety outcomes with improved postoperative recovery,such as shorter hospital stays and reduced transfusion rates,despite potentially longer operative times.METHODS A systematic review was performed using EMBASE,OVID,Scopus,PubMed,Cochrane,and ScienceDirect databases to identify studies comparing robotic surgery and sternotomy for cardiac myxoma excision.Continuous outcomes were analyzed using mean differences(MDs),and categorical outcomes with odds ratios(ORs)and 95%confidence intervals(95%CIs).A random-effects model was used to pool data,accounting for study heterogeneity.RESULTS Six studies involving 425 patients(180 robotic,245 conventional)were included.Robotic surgery significantly increased cross-clamp time(MD=12.03 minutes,95%CI:2.14-21.92,P=0.02)and cardiopulmonary bypass time(MD=28.37 minutes,95%CI:11.85-44.89,P=0.001).It reduced hospital stay(MD=-1.86 days,95%CI:-2.45 to-1.27,P<0.00001)and blood transfusion requirements(OR=0.30,95%CI:0.13-0.69,P=0.007).No significant differences were observed in atrial arrhythmia(OR=0.55,95%CI:0.27-1.12)or ventilation time(MD=-1.72 hours,95%CI:-5.27 to 1.83,P=0.34).CONCLUSION Robotic surgery for cardiac myxoma excision prolongs operative times but shortens hospital stays and reduces transfusion needs,suggesting enhanced recovery without compromising safety.展开更多
During the supersonic re-entry of multi-nozzle heavy rockets into the atmosphere,the basic flow state becomes increasingly complex due to the coupling effect between the retropropulsion plumes and the freestream.A num...During the supersonic re-entry of multi-nozzle heavy rockets into the atmosphere,the basic flow state becomes increasingly complex due to the coupling effect between the retropropulsion plumes and the freestream.A numerical method using the hybrid Reynolds-Averaged Navier-Stokes and Large Eddy Simulation(RES)method and discrete coordinate method is developed to accurately estimate the thermal environment.In addition,finite rate chemical kinetics is used to calculate the afterburning reactions.The numerical results agree well with wind tunnel data,which confirms the validity and accuracy of the numerical method.Computations are conducted for the heavy carrier rocket re-entry from 53.1 km to 39.5 km altitude with 180°angle of attack by using three different Supersonic Retro-Propulsion(SRP)modes.The numerical results reveal that these three SRP flow fields are all Short Penetration Models(SPM).As the re-entry altitudes decrease,both the plume-plume interaction and the plume-freestream interaction become weaker.The highest temperatures in the plume shear layers of the three SRP modes increase by 8.36%,7.33%and 6.92%respectively after considering afterburning reactions,and all occur at a reentry altitude of 39.5 km.As the rocket re-enters the atmosphere,the maximum heat flux on the rocket base plate of three SRP modes stabilizes at 290,170 and 200 kW/m^(2) respectively,but the maximum heat flux on the side wall increases significantly.When the altitude declines to 39.5 km,the extreme heat flux of the three modes increase by 84.16%,49.45%and 62.97%respectively compared to that at 53.1 km.展开更多
Background:Hypertrophic scars and keloids,common complications following median sternotomy for cardiac surgery,significantly impact patient quality of life due to their aesthetic and symptomatic burden.Recent advanceme...Background:Hypertrophic scars and keloids,common complications following median sternotomy for cardiac surgery,significantly impact patient quality of life due to their aesthetic and symptomatic burden.Recent advancements in laser therapy have made it a prominent option for managing these complex scars,yet a com-prehensive understanding of its efficacy is lacking.The aim of this scoping review is to explore the effects of laser therapy in managing hypertrophic scars and keloids after median sternotomy.Methods:This scoping review ana-lyzed studies up to February 2024 from databases including PubMed,EMBASE,CINAHL,Scopus,Web of Science,and the Cochrane Library.We included any study that assessed laser therapy’s effects on hypertrophic scars and keloids following median sternotomy.Studies were selected based on predefined inclusion criteria with-out publication year,design,or origin restrictions.Results:Six studies met the inclusion criteria,involving a total offive RCTs and one review.These studies primarily tested 585 and 595-nm pulsed dye laser(PDL)treatments,focusing on scar appearance,patient symptoms,and treatment satisfaction.Most studies reported significant improvements in scar height reduction and patient symptom relief after treatment,with mixed results for scar erythema and elasticity.Adverse events were generally mild and transient.Conclusions:Laser therapy offers a beneficial approach for improving the appearance and symptoms of hypertrophic scars and keloids post-median sternotomy.However,further research is necessary to optimize treatment parameters and explore the long-term psychosocial impacts of this therapy.This review highlights the need for more comprehensive studies to establish standardized treatment protocols and evaluate their effectiveness.展开更多
The attack angle may greatly affect the hypersonic plasma sheaths around the re-entry vehicle,thereby affecting the transmission characteristics of electromagnetic(EM)waves in the sheaths.In this paper,we propose an i...The attack angle may greatly affect the hypersonic plasma sheaths around the re-entry vehicle,thereby affecting the transmission characteristics of electromagnetic(EM)waves in the sheaths.In this paper,we propose an integrated three-dimensional(3D)model with various attack angles and realistic flying conditions of radio attenuation measurement C-II(RAM C-II)re-entry tasks for analyzing the effect of the attack angle on the transmission characteristics of EM waves in the sheaths.It is shown that the electron density and collision frequency of the sheath on the windward side can be increased by an order of magnitude with the increase of the attack angle.Meanwhile,the thickness of the sheath on the leeward side is increased where the electron density and collision frequency are reduced.The EM waves are mainly reflected on the windward plasma sheath due to the cutoff effect,and the radio-frequency(RF)blackout is mitigated if the antenna is positioned on the leeward side.Thus,by planning the trajectory properly and installing the antenna accordingly during the re-entry,it is possible to provide an approach for mitigation of the RF blackout problem to an extent.展开更多
Background: Left atrial myxoma (LAM) is the most common heart tumor in adults, requiring prompt surgical removal to prevent complications like valvular obstruction or embolization. Objectives: This study aimed to comp...Background: Left atrial myxoma (LAM) is the most common heart tumor in adults, requiring prompt surgical removal to prevent complications like valvular obstruction or embolization. Objectives: This study aimed to compare early postoperative outcomes between two surgical approaches—right mini-thoracotomy and median sternotomy—for the removal of isolated left atrial myxoma. Methods: We conducted a prospective observational study at the Department of Cardiac Surgery, National Heart Foundation Hospital & Research Institute (NHFH&RI), Mirpur, Dhaka, from March 2017 to August 2019. Twenty-eight patients undergoing surgery for isolated left atrial myxoma were included. The surgical approach was determined by the operating surgeon. We analyzed outcomes like intubation time, Intensive Care Unit (ICU) stay, pain levels (Visual Analogue Scale score), and overall hospital stay using SPSS. Statistical significance was set at p Results: Patients in the right mini-thoracotomy group had longer mean intubation times (11.43 vs. 5.93 hours, p Conclusion: Despite longer intubation and ICU times, the right mini-thoracotomy approach offers a minimally invasive alternative for isolated left atrial myxoma excision, with favorable outcomes overall.展开更多
In re-entry, the drilling riser hanging to the holding vessel takes on a free hanging state, waiting to be moved from the initial random position to the wellhead. For the re-entry, dynamics calculation is often done t...In re-entry, the drilling riser hanging to the holding vessel takes on a free hanging state, waiting to be moved from the initial random position to the wellhead. For the re-entry, dynamics calculation is often done to predict the riser motion or evaluate the structural safety. A dynamics calculation method based on Flexible Segment Model （FSM） is proposed for free hanging marine risers. In FSM, a riser is discretized into a series of flexible segments. For each flexible segment, its deflection feature and external forces are analyzed independently. For the whole riser, the nonlinear governing equations are listed according to the moment equilibrium at nodes. For the solution of the nonlinear equations, a linearization iteration scheme is provided in the paper. Owing to its flexibility, each segment can match a long part of the riser body, which enables that good results can be obtained even with a small number of segments. Moreover, the linearization iteration scheme can avoid widely used Newton-Rapson iteration scheme in which the calculation stability is influenced by the initial points. The FSM-based dynamics calculation is timesaving and stable, so suitable for the shape prediction or real-time control of free hanging marine risers.展开更多
Objective To assess clinical effectiveness of using bilateral pectoralis major or plus rectus abdominis muscle flaps in treating deep sternal wound infection(DSWI) following median sternotomy. Methods Between January ...Objective To assess clinical effectiveness of using bilateral pectoralis major or plus rectus abdominis muscle flaps in treating deep sternal wound infection(DSWI) following median sternotomy. Methods Between January 2009 and December 2013, 19 patients with DSWI after median sternotomy for cardiac surgery were admitted to our hospital, including 14 males(73.7%) and 5 females(26.3%), aged 55±13(18-78) years. According to the Pairolero classification of infected median sternotomies, 3(15.8%) patients were type II, and the other 16(84.2%) were type III. Surgical procedure consisted of adequate debridement of infected sternum, costal cartilage, granulation, steel wires, suture residues and other foreign substances. Sternal reconstruction used the bilateral pectoralis major or plus rectus abdominis muscle flaps to obliterate dead space. The drainage tubes were placed and connected to a negative pressure generator for adequate drainage. Results There were no intraoperative deaths. In 15 patients(78.9%), bilateral pectoral muscle flaps were mobilized sufficiently to cover and stabilize the defect created by wound debridement. 4 patients(21.0%) needed bilateral pectoral muscle flaps plus rectus abdominis muscle flaps because their pectoralis major muscle flaps could not reach the lowest portion of the wound. 2 patients(10.5%) presented with subcutaneous infection, and 3 patients(15.8%) had hematoma. They recovered following local debridement and medication. 17 patients(89.5%) were examined at follow-up 12 months later, all healed and having stable sternum. No patients showed infection recurrence during the follow-up period over 12 months. Conclusion DSWI following median sternotomy may be effectively managed with adequate debridement of infected tissues and reconstruction with bilateral pectoralis major muscle or plus rectus abdominis muscle flap transposition.展开更多
Ballistic parameter plays a major role in determining the re-entry trajectory.Lower ballistic coefficient offers an optimal re-entry,wherein the vehicle decelerates higher up in the atmosphere thereby decreasing the i...Ballistic parameter plays a major role in determining the re-entry trajectory.Lower ballistic coefficient offers an optimal re-entry,wherein the vehicle decelerates higher up in the atmosphere thereby decreasing the imposed aerothermal loads.The current computational study proposes an add-on,to the existing Orion-based re-entry vehicle:a duct circumventing the capsule from the shoulder to the base,to improve the aerocapture ability of the re-entry vehicle.The design cases are categorised based on a non-dimensional parameter termed the Annular Area Ratio(AAR).Dragand ballistic coefficient of the Ducted Re-entry Vehicles(DRVs)at various Mach numbers are evaluated and compared with those of the baseline model.The results show that the proposed design increases the drag for all the AARs considered in the subsonic regime.In the supersonic regime,ducted models of higher AAR are more promising with the increase in Mach number.DRVs also exhibit lower ballistic coefficients than their baseline counterparts.展开更多
Objective： Mitral valve disease tends to be treated with anterolateral minithoracotomy （ALMT） rather than median stemotomy （MS）, as ALMT uses progressively smaller incisions to promote better cosmetic outcomes. T...Objective： Mitral valve disease tends to be treated with anterolateral minithoracotomy （ALMT） rather than median stemotomy （MS）, as ALMT uses progressively smaller incisions to promote better cosmetic outcomes. This meta-analysis quantifies the effects of ALMT on surgical parameters and post-operative outcomes compared with MS. Methods： One randomized controlled study and four case-control studies, published in English from January 1996 to January 2013, were identified and evaluated. Results： ALMT showed a significantly longer cardiopulmonary bypass time （P=0.001） and aortic cross-clamp time （P=0.05） compared with MS. However, the benefits of ALMT were evident as demonstrated by a shorter length of hospital stay （P〈0.00001）. According to operative complications, the onset of new arrhythmias following ALMT decreased significantly as compared with MS （P=0.05）; however, the incidence of peri-operative mortality （P=0.62）, re-operation for bleeding （P=0.37）, neurologic events （P=0.77）, myocardial infarction （P=0.84）, gastrointestinal complications （P=0.89）, and renal insufficiency （P=0.67） were similar to these of MS. Long-term follow-up data were also examined, and revealed equivalent survival and freedom from mitral valve events. Conclusions： Current clinical data suggest that ALMT is a safe and effective alternative to the conventional approach and is associated with better short-term outcomes and a trend towards longer survival.展开更多
AIM: To increase the stability of sternotomy and so decrease the complications because of instability. METHODS: Tests were performed on 20 fresh sheep sterna which were isolated from the sterno-costa joints of the rib...AIM: To increase the stability of sternotomy and so decrease the complications because of instability. METHODS: Tests were performed on 20 fresh sheep sterna which were isolated from the sterno-costa joints of the ribs. Median straight and interlocking sternotomies were performed on 10 sterna each, set as groups 1 and 2, respectively. Both sternotomies were performed with an oscillating saw and closed at three points with a No. 5 straight stainless-stee wiring. Fatigue testing was performed in craniocaudal, anterio-posterior(AP) and lateral directions by a computerized materials-testing machine cycling between loads of 0 to 400 N per 5 s(0.2 Hz). The amount of displacement in AP, lateral and craniocaudal directions were measured and also the op-posing bone surface at the osteotomy areas were calculated at the two halves of sternum. RESULTS: The mean displacement in cranio-caudal direction was 9.66 ± 3.34 mm for median sternotomy and was 1.26 ± 0.97 mm for interlocking sternotomy, P < 0.001. The mean displacement in AP direction was 9.12 ± 2.74 mm for median sternotomy and was 1.20 ± 0.55 mm for interlocking sternotomy, P < 0.001. The mean displacement in lateral direction was 8.95 ± 3.86 mm for median sternotomy and was 7.24 ± 2.43 mm for interlocking sternotomy, P > 0.001. The mean surface area was 10.40 ± 0.49 cm2 for median sternotomy and was 16.8 ± 0.78 cm2 for interlocking sternotomy, P < 0.001. The displacement in AP and cranio-caudal directions is less in group 2 and it is statistically significant. Displacement in lateral direction in group 2 is less but it is statistically not significant. Surface area in group 2 is significantly wider than group 1.CONCLUSION: Our test results demonstrated improved primary stability and wider opposing bone surfaces in interlocking sternotomy compared to median sternotomy. This method may provide better healing and less complication rates in clinical setting, further studies are necessary for its clinical implications.展开更多
Introduction: Patients presenting with cardiac injuries from gunshot wounds and blunt chest trauma have high mortality, without any observed survival benefit when presenting with cardiac tamponade. Cardiac tamponade i...Introduction: Patients presenting with cardiac injuries from gunshot wounds and blunt chest trauma have high mortality, without any observed survival benefit when presenting with cardiac tamponade. Cardiac tamponade is a life-threatening hemodynamically significant compression of the heart by a sudden or gradual accumulation of collections in the pericardial space that incites and overrides the body’s compensatory mechanism. Clinical Case: We present and discuss the successful management and survival of two patients with traumatic cardiac tamponade from gunshot wounds to the precordium who underwent successful lifesaving median sternotomy at a Teaching Hospital in Ghana with a new Cardiovascular and Thoracic Surgery Unit. Discussion: Usually the diagnosis of cardiac tamponade from traumatic haemopericardium is made by clinical findings which though may not always be present especially after blunt chest trauma. EFAST is a reliable tool for diagnosing and following cardiac tamponade. Median sternotomy is the standard procedure in these patients to access and repair cardiac injury either with or without cardiopulmonary bypass. Conclusion: Emergency median sternotomy in patients with cardiac tamponade from chest trauma especially after EFAST diagnosis can be lifesaving even in less resourced centres.展开更多
Objectives: Due to recent spread of minimally invasive surgery, the demand for minimally invasive cardiac surgery (MICS) is increasing. We investigate the usefulness of minimally invasive aortic valve replacement (MIC...Objectives: Due to recent spread of minimally invasive surgery, the demand for minimally invasive cardiac surgery (MICS) is increasing. We investigate the usefulness of minimally invasive aortic valve replacement (MICS-AVR) which was performed in our hospital. Methods: Of 63 consecutive patients undergone an isolated aortic valve replacement (AVR), 16 patients underwent MICS-AVR with partial lower sternotomy (M group) and 47 patients underwent AVR with median full sternotomy (C group). We compared the two groups in a retrospective study. Results: No significant difference was found in the surgical and perioperative-related factors between the two groups. However, the average of aortic cross-clamping time was longer, and intensive and high care unit stay was shorter in the M group. A tendency to decrease blood transfusion was observed in the M group. There was no hospital death in all patients. The mean follow-up period was 29 ± 15 months. There was no significant difference between the two groups in the survival rate, and the 5-year survival rates were 88.9% in the M group and 85.9% in the C group. Conclusion: It was suggested that the MICS-AVR could be safe and useful procedure in AVR.展开更多
Redo sternotomy in pediatric patients can be complicated due to the unsuitability of many arterial cannulation sites for the pediatric population. Innominate artery cannulation provides a safe and easily reproducible ...Redo sternotomy in pediatric patients can be complicated due to the unsuitability of many arterial cannulation sites for the pediatric population. Innominate artery cannulation provides a safe and easily reproducible alternative and prevents many of the disadvantages seen in femoral and axillary artery cannulation. Its use in pediatric cardiac surgery has seen a rise [1]. Herein, we describe the technique for innominate artery cannulation in pediatric patients undergoing redo sternotomy and review our experience with the technique.展开更多
Background: Retrosternal goiters (RG) are those lesions extending to occupy the thoracic cavity. They carry a surgical risk due to distorted anatomy, the minimal access, and the potential for great vessels or pleural ...Background: Retrosternal goiters (RG) are those lesions extending to occupy the thoracic cavity. They carry a surgical risk due to distorted anatomy, the minimal access, and the potential for great vessels or pleural injury. No other effective therapeutic alternative to surgery exists. Cervicotomy is still the surgical approach of choice, although a form of sternotomy may always be necessary for field extension and safe gland delivery. Materials and Methods: This is a single institution combined retrospective & prospective study including retrospective analysis of all cases presenting to the NCI, Cairo University with RG candidate for surgery between Jan. 2008 until the end of Dec. 2012, and a prospective study of all cases with the same presentation presenting to the NCI between Jan. 2013 until the end of Dec. 2015. Data was collected from archive of patients at the statistical department. Aims: To study the clinico-pathological characteristics, the presentation, work-up, surgical approaches and postoperative complications of RG. Results: 42 patients were included & were divided into benign (34 patients, 80.9%) and malignant groups (8 cases, 19.1%). All patients (100%) were adults ranging (19 to 73 years) with mean 53.1 years. There was a female predominance (36 female, 85.7%) versus (6 males, 14.3%). Median duration of symptomatology was 23 months ranging (6 - 53 months). 23 patients (54.7%) were symptomatic while 19 cases (45.3%) accidently discovered. Mean tumor size was 9.97 cm in the benign group and 11.1 cm in the malignant group. 31 patients (73.8%) were euthyroid, 9 (21.4%) were thyrotoxic and 2 (4.7%) were hypothyroid. All patients (100%) underwent total thyroidectomy. The commonest approach was cervicotomy (33 cases, 78.6%), while a type of sternotomy was done in 9 cases (21.4%). 2 cases (4.7%) received postoperative radiation therapy & 4 cases (9.5%) received postoperative radioactive iodine. No perioperative mortality occurred & the overall morbidity was 6 cases (14.2%) in the benign group and 2 cases (4.7%) in the malignant group (4.7%). The median follow up period was 17.5 months. The median overall survival (OS) was 39.4 months and the median disease free survival (DFS) was 9.8 months for the malignant group. Conclusion: Cervicotomy is a safe favorable approach to remove a RG. Intraoperative field extension up to a form of sternotomy may be necessary for gland delivery with increasing operating time, hospital stay and morbidity. Postoperative morbidity is mainly due to the respiratory, recurrent laryngeal nerve palsy and hypoparathyroidism which is mainly increased when sternotomy is performed.展开更多
文摘Background: The vasoactive-ventilation-renal (VVR) score includes pulmonary and renal dysfunctions not previously addressed by the vasoactive inotrope score (VIS) and may be a better predictor of cardiac care unit (CCU) length of stay (LOS) in patients undergoing re-entry sternotomy (defined as no earlier than 30 days after previous sternotomy) for congenital heart disease (CHD). Methods: Patients undergoing re-entry sternotomy for CHD from August 1, 2009 to June 30, 2016 were studied retrospectively. A total of 96 patients undergoing 133 re-entry procedures were identified. VVR scores were calculated on CCU admission post-procedure (at 0 hour), 24-hour, and 48-hour after admission to the CCU. The response variable was CCU LOS.? Recursive partition analysis identified variables predicting LOS. Results: 133 re-entry sternotomies in 96 patients made up the samples of the database;11 samples were removed due to incomplete data or placement on ECMO. Of the initial 25 features, 5 were removed for near zero variance and 3 categorical features were removed for non-information. Covariance analysis did not demonstrate any significant correlation amongst the remaining features. Initial recursive tree regression using ANOVA, cross validation and conditional predictive p-value (cp) = 0.01 produced 3 trees. The tree with lowest cross validation error was selected. The resulting 2 split trees with ventilator days less than 20 days and VVR score at 48 hours greater than 23 identified three CCU LOS groups with mean CCU LOS of 77.6, 55.1, and 9.5 days. Conclusions: Recursive partition analysis identified ventilator days greater than 20 days and the sub-population VVR at 48 hours as predictive of CCU LOS in patients undergoing re-entry sternotomy for CHD.
文摘BACKGROUND Obese patients(body mass index≥30 kg/m^(2))undergoing isolated aortic valve replacement(AVR)face increased surgical risks due to comorbidities.Partial upper sternotomy(PUS),a minimally invasive approach,may reduce complications compared to full median sternotomy(FMS).We hypothesize that PUS improves outcomes over FMS in obese patients undergoing AVR.AIM To compare the efficacy and safety of PUS vs FMS in obese patients undergoing isolated AVR.METHODS This systematic review and meta-analysis followed PRISMA guidelines,searching PubMed,EMBASE,and Cochrane databases for observational studies comparing PUS vs FMS in obese patients undergoing AVR.Outcomes were analyzed using odds ratios(OR),mean differences(MD),95%confidence intervals(CI),I^(2)statistic,and Newcastle-Ottawa Scale was used for quality assessment.RESULTS Four observational studies involving 677 patients were analyzed.PUS reduced intensive care unit stay(MD-2.67 days,95%CI:-4.43 to-0.90,P=0.003,I^(2)=78%)but increased cardiopulmonary bypass time(MD 5.62 minutes,95%CI:-0.36 to 11.59,I^(2)=55%).No differences were observed in renal failure(OR 1.13,95%CI:0.63-2.94,I^(2)=0%),atrial fibrillation(OR 0.81,95%CI:0.43-1.54,I^(2)=30%),reexploration(OR 1.09,95%CI:0.48-2.47,I^(2)=0%),postoperative bleeding(OR 1.48,95%CI:0.53-4.15,I^(2)=60%),wound infection(OR 1.23,95%CI:0.70-2.14,I^(2)=0%),hospital stay(MD 0.51 days,95%CI:-4.13 to 5.15,I^(2)=90%),or cross-clamp time(MD 4.03 minutes,95%CI:-0.75 to 8.80,I^(2)=50%).CONCLUSION PUS is safe and effective for obese patients undergoing AVR,reducing intensive care unit stay and enhancing recovery,provided surgical expertise is available.
文摘BACKGROUND Cardiac myxoma,a benign intracardiac tumor,is traditionally excised via conven-tional sternotomy,which is invasive and associated with longer recovery times.Minimally invasive robotic surgery has emerged as a potential alternative,offe-ring reduced trauma and faster recovery.This meta-analysis compares the effi-cacy and safety of robotic surgery vs conventional sternotomy for cardiac myxo-ma excision.We hypothesized that robotic surgery would provide comparable safety outcomes with improved postoperative recovery,such as shorter hospital stays and reduced transfusion rates,despite potentially longer operative times.METHODS A systematic review was performed using EMBASE,OVID,Scopus,PubMed,Cochrane,and ScienceDirect databases to identify studies comparing robotic surgery and sternotomy for cardiac myxoma excision.Continuous outcomes were analyzed using mean differences(MDs),and categorical outcomes with odds ratios(ORs)and 95%confidence intervals(95%CIs).A random-effects model was used to pool data,accounting for study heterogeneity.RESULTS Six studies involving 425 patients(180 robotic,245 conventional)were included.Robotic surgery significantly increased cross-clamp time(MD=12.03 minutes,95%CI:2.14-21.92,P=0.02)and cardiopulmonary bypass time(MD=28.37 minutes,95%CI:11.85-44.89,P=0.001).It reduced hospital stay(MD=-1.86 days,95%CI:-2.45 to-1.27,P<0.00001)and blood transfusion requirements(OR=0.30,95%CI:0.13-0.69,P=0.007).No significant differences were observed in atrial arrhythmia(OR=0.55,95%CI:0.27-1.12)or ventilation time(MD=-1.72 hours,95%CI:-5.27 to 1.83,P=0.34).CONCLUSION Robotic surgery for cardiac myxoma excision prolongs operative times but shortens hospital stays and reduces transfusion needs,suggesting enhanced recovery without compromising safety.
基金co-supported by the National Level Project,China and Shanghai Municipal Major Science and Technology Project,China.In addition,the authors gratefully acknowledge the guidance on English writing and numerical methods of Professor Junfeng ZHANG from the Faculty of Engineering at Laurentian University.
文摘During the supersonic re-entry of multi-nozzle heavy rockets into the atmosphere,the basic flow state becomes increasingly complex due to the coupling effect between the retropropulsion plumes and the freestream.A numerical method using the hybrid Reynolds-Averaged Navier-Stokes and Large Eddy Simulation(RES)method and discrete coordinate method is developed to accurately estimate the thermal environment.In addition,finite rate chemical kinetics is used to calculate the afterburning reactions.The numerical results agree well with wind tunnel data,which confirms the validity and accuracy of the numerical method.Computations are conducted for the heavy carrier rocket re-entry from 53.1 km to 39.5 km altitude with 180°angle of attack by using three different Supersonic Retro-Propulsion(SRP)modes.The numerical results reveal that these three SRP flow fields are all Short Penetration Models(SPM).As the re-entry altitudes decrease,both the plume-plume interaction and the plume-freestream interaction become weaker.The highest temperatures in the plume shear layers of the three SRP modes increase by 8.36%,7.33%and 6.92%respectively after considering afterburning reactions,and all occur at a reentry altitude of 39.5 km.As the rocket re-enters the atmosphere,the maximum heat flux on the rocket base plate of three SRP modes stabilizes at 290,170 and 200 kW/m^(2) respectively,but the maximum heat flux on the side wall increases significantly.When the altitude declines to 39.5 km,the extreme heat flux of the three modes increase by 84.16%,49.45%and 62.97%respectively compared to that at 53.1 km.
文摘Background:Hypertrophic scars and keloids,common complications following median sternotomy for cardiac surgery,significantly impact patient quality of life due to their aesthetic and symptomatic burden.Recent advancements in laser therapy have made it a prominent option for managing these complex scars,yet a com-prehensive understanding of its efficacy is lacking.The aim of this scoping review is to explore the effects of laser therapy in managing hypertrophic scars and keloids after median sternotomy.Methods:This scoping review ana-lyzed studies up to February 2024 from databases including PubMed,EMBASE,CINAHL,Scopus,Web of Science,and the Cochrane Library.We included any study that assessed laser therapy’s effects on hypertrophic scars and keloids following median sternotomy.Studies were selected based on predefined inclusion criteria with-out publication year,design,or origin restrictions.Results:Six studies met the inclusion criteria,involving a total offive RCTs and one review.These studies primarily tested 585 and 595-nm pulsed dye laser(PDL)treatments,focusing on scar appearance,patient symptoms,and treatment satisfaction.Most studies reported significant improvements in scar height reduction and patient symptom relief after treatment,with mixed results for scar erythema and elasticity.Adverse events were generally mild and transient.Conclusions:Laser therapy offers a beneficial approach for improving the appearance and symptoms of hypertrophic scars and keloids post-median sternotomy.However,further research is necessary to optimize treatment parameters and explore the long-term psychosocial impacts of this therapy.This review highlights the need for more comprehensive studies to establish standardized treatment protocols and evaluate their effectiveness.
基金supported by National Natural Science Foundation of China(Nos.92271202 and 92371105)。
文摘The attack angle may greatly affect the hypersonic plasma sheaths around the re-entry vehicle,thereby affecting the transmission characteristics of electromagnetic(EM)waves in the sheaths.In this paper,we propose an integrated three-dimensional(3D)model with various attack angles and realistic flying conditions of radio attenuation measurement C-II(RAM C-II)re-entry tasks for analyzing the effect of the attack angle on the transmission characteristics of EM waves in the sheaths.It is shown that the electron density and collision frequency of the sheath on the windward side can be increased by an order of magnitude with the increase of the attack angle.Meanwhile,the thickness of the sheath on the leeward side is increased where the electron density and collision frequency are reduced.The EM waves are mainly reflected on the windward plasma sheath due to the cutoff effect,and the radio-frequency(RF)blackout is mitigated if the antenna is positioned on the leeward side.Thus,by planning the trajectory properly and installing the antenna accordingly during the re-entry,it is possible to provide an approach for mitigation of the RF blackout problem to an extent.
文摘Background: Left atrial myxoma (LAM) is the most common heart tumor in adults, requiring prompt surgical removal to prevent complications like valvular obstruction or embolization. Objectives: This study aimed to compare early postoperative outcomes between two surgical approaches—right mini-thoracotomy and median sternotomy—for the removal of isolated left atrial myxoma. Methods: We conducted a prospective observational study at the Department of Cardiac Surgery, National Heart Foundation Hospital & Research Institute (NHFH&RI), Mirpur, Dhaka, from March 2017 to August 2019. Twenty-eight patients undergoing surgery for isolated left atrial myxoma were included. The surgical approach was determined by the operating surgeon. We analyzed outcomes like intubation time, Intensive Care Unit (ICU) stay, pain levels (Visual Analogue Scale score), and overall hospital stay using SPSS. Statistical significance was set at p Results: Patients in the right mini-thoracotomy group had longer mean intubation times (11.43 vs. 5.93 hours, p Conclusion: Despite longer intubation and ICU times, the right mini-thoracotomy approach offers a minimally invasive alternative for isolated left atrial myxoma excision, with favorable outcomes overall.
基金supported by the National Natural Science Foundation of China (Grant No. 51009092)the Doctoral Foundation of Education Ministry of China (Grant No. 20090073120013)the Scientific Research Foundation of State Education Ministry for the Returned Overseas Chinese Scholars
文摘In re-entry, the drilling riser hanging to the holding vessel takes on a free hanging state, waiting to be moved from the initial random position to the wellhead. For the re-entry, dynamics calculation is often done to predict the riser motion or evaluate the structural safety. A dynamics calculation method based on Flexible Segment Model （FSM） is proposed for free hanging marine risers. In FSM, a riser is discretized into a series of flexible segments. For each flexible segment, its deflection feature and external forces are analyzed independently. For the whole riser, the nonlinear governing equations are listed according to the moment equilibrium at nodes. For the solution of the nonlinear equations, a linearization iteration scheme is provided in the paper. Owing to its flexibility, each segment can match a long part of the riser body, which enables that good results can be obtained even with a small number of segments. Moreover, the linearization iteration scheme can avoid widely used Newton-Rapson iteration scheme in which the calculation stability is influenced by the initial points. The FSM-based dynamics calculation is timesaving and stable, so suitable for the shape prediction or real-time control of free hanging marine risers.
文摘Objective To assess clinical effectiveness of using bilateral pectoralis major or plus rectus abdominis muscle flaps in treating deep sternal wound infection(DSWI) following median sternotomy. Methods Between January 2009 and December 2013, 19 patients with DSWI after median sternotomy for cardiac surgery were admitted to our hospital, including 14 males(73.7%) and 5 females(26.3%), aged 55±13(18-78) years. According to the Pairolero classification of infected median sternotomies, 3(15.8%) patients were type II, and the other 16(84.2%) were type III. Surgical procedure consisted of adequate debridement of infected sternum, costal cartilage, granulation, steel wires, suture residues and other foreign substances. Sternal reconstruction used the bilateral pectoralis major or plus rectus abdominis muscle flaps to obliterate dead space. The drainage tubes were placed and connected to a negative pressure generator for adequate drainage. Results There were no intraoperative deaths. In 15 patients(78.9%), bilateral pectoral muscle flaps were mobilized sufficiently to cover and stabilize the defect created by wound debridement. 4 patients(21.0%) needed bilateral pectoral muscle flaps plus rectus abdominis muscle flaps because their pectoralis major muscle flaps could not reach the lowest portion of the wound. 2 patients(10.5%) presented with subcutaneous infection, and 3 patients(15.8%) had hematoma. They recovered following local debridement and medication. 17 patients(89.5%) were examined at follow-up 12 months later, all healed and having stable sternum. No patients showed infection recurrence during the follow-up period over 12 months. Conclusion DSWI following median sternotomy may be effectively managed with adequate debridement of infected tissues and reconstruction with bilateral pectoralis major muscle or plus rectus abdominis muscle flap transposition.
基金supported by Research and Modernization FundSASTRA University(No.R&M/0035/So ME008/2015-17)。
文摘Ballistic parameter plays a major role in determining the re-entry trajectory.Lower ballistic coefficient offers an optimal re-entry,wherein the vehicle decelerates higher up in the atmosphere thereby decreasing the imposed aerothermal loads.The current computational study proposes an add-on,to the existing Orion-based re-entry vehicle:a duct circumventing the capsule from the shoulder to the base,to improve the aerocapture ability of the re-entry vehicle.The design cases are categorised based on a non-dimensional parameter termed the Annular Area Ratio(AAR).Dragand ballistic coefficient of the Ducted Re-entry Vehicles(DRVs)at various Mach numbers are evaluated and compared with those of the baseline model.The results show that the proposed design increases the drag for all the AARs considered in the subsonic regime.In the supersonic regime,ducted models of higher AAR are more promising with the increase in Mach number.DRVs also exhibit lower ballistic coefficients than their baseline counterparts.
文摘Objective： Mitral valve disease tends to be treated with anterolateral minithoracotomy （ALMT） rather than median stemotomy （MS）, as ALMT uses progressively smaller incisions to promote better cosmetic outcomes. This meta-analysis quantifies the effects of ALMT on surgical parameters and post-operative outcomes compared with MS. Methods： One randomized controlled study and four case-control studies, published in English from January 1996 to January 2013, were identified and evaluated. Results： ALMT showed a significantly longer cardiopulmonary bypass time （P=0.001） and aortic cross-clamp time （P=0.05） compared with MS. However, the benefits of ALMT were evident as demonstrated by a shorter length of hospital stay （P〈0.00001）. According to operative complications, the onset of new arrhythmias following ALMT decreased significantly as compared with MS （P=0.05）; however, the incidence of peri-operative mortality （P=0.62）, re-operation for bleeding （P=0.37）, neurologic events （P=0.77）, myocardial infarction （P=0.84）, gastrointestinal complications （P=0.89）, and renal insufficiency （P=0.67） were similar to these of MS. Long-term follow-up data were also examined, and revealed equivalent survival and freedom from mitral valve events. Conclusions： Current clinical data suggest that ALMT is a safe and effective alternative to the conventional approach and is associated with better short-term outcomes and a trend towards longer survival.
文摘AIM: To increase the stability of sternotomy and so decrease the complications because of instability. METHODS: Tests were performed on 20 fresh sheep sterna which were isolated from the sterno-costa joints of the ribs. Median straight and interlocking sternotomies were performed on 10 sterna each, set as groups 1 and 2, respectively. Both sternotomies were performed with an oscillating saw and closed at three points with a No. 5 straight stainless-stee wiring. Fatigue testing was performed in craniocaudal, anterio-posterior(AP) and lateral directions by a computerized materials-testing machine cycling between loads of 0 to 400 N per 5 s(0.2 Hz). The amount of displacement in AP, lateral and craniocaudal directions were measured and also the op-posing bone surface at the osteotomy areas were calculated at the two halves of sternum. RESULTS: The mean displacement in cranio-caudal direction was 9.66 ± 3.34 mm for median sternotomy and was 1.26 ± 0.97 mm for interlocking sternotomy, P < 0.001. The mean displacement in AP direction was 9.12 ± 2.74 mm for median sternotomy and was 1.20 ± 0.55 mm for interlocking sternotomy, P < 0.001. The mean displacement in lateral direction was 8.95 ± 3.86 mm for median sternotomy and was 7.24 ± 2.43 mm for interlocking sternotomy, P > 0.001. The mean surface area was 10.40 ± 0.49 cm2 for median sternotomy and was 16.8 ± 0.78 cm2 for interlocking sternotomy, P < 0.001. The displacement in AP and cranio-caudal directions is less in group 2 and it is statistically significant. Displacement in lateral direction in group 2 is less but it is statistically not significant. Surface area in group 2 is significantly wider than group 1.CONCLUSION: Our test results demonstrated improved primary stability and wider opposing bone surfaces in interlocking sternotomy compared to median sternotomy. This method may provide better healing and less complication rates in clinical setting, further studies are necessary for its clinical implications.
文摘Introduction: Patients presenting with cardiac injuries from gunshot wounds and blunt chest trauma have high mortality, without any observed survival benefit when presenting with cardiac tamponade. Cardiac tamponade is a life-threatening hemodynamically significant compression of the heart by a sudden or gradual accumulation of collections in the pericardial space that incites and overrides the body’s compensatory mechanism. Clinical Case: We present and discuss the successful management and survival of two patients with traumatic cardiac tamponade from gunshot wounds to the precordium who underwent successful lifesaving median sternotomy at a Teaching Hospital in Ghana with a new Cardiovascular and Thoracic Surgery Unit. Discussion: Usually the diagnosis of cardiac tamponade from traumatic haemopericardium is made by clinical findings which though may not always be present especially after blunt chest trauma. EFAST is a reliable tool for diagnosing and following cardiac tamponade. Median sternotomy is the standard procedure in these patients to access and repair cardiac injury either with or without cardiopulmonary bypass. Conclusion: Emergency median sternotomy in patients with cardiac tamponade from chest trauma especially after EFAST diagnosis can be lifesaving even in less resourced centres.
文摘Objectives: Due to recent spread of minimally invasive surgery, the demand for minimally invasive cardiac surgery (MICS) is increasing. We investigate the usefulness of minimally invasive aortic valve replacement (MICS-AVR) which was performed in our hospital. Methods: Of 63 consecutive patients undergone an isolated aortic valve replacement (AVR), 16 patients underwent MICS-AVR with partial lower sternotomy (M group) and 47 patients underwent AVR with median full sternotomy (C group). We compared the two groups in a retrospective study. Results: No significant difference was found in the surgical and perioperative-related factors between the two groups. However, the average of aortic cross-clamping time was longer, and intensive and high care unit stay was shorter in the M group. A tendency to decrease blood transfusion was observed in the M group. There was no hospital death in all patients. The mean follow-up period was 29 ± 15 months. There was no significant difference between the two groups in the survival rate, and the 5-year survival rates were 88.9% in the M group and 85.9% in the C group. Conclusion: It was suggested that the MICS-AVR could be safe and useful procedure in AVR.
文摘Redo sternotomy in pediatric patients can be complicated due to the unsuitability of many arterial cannulation sites for the pediatric population. Innominate artery cannulation provides a safe and easily reproducible alternative and prevents many of the disadvantages seen in femoral and axillary artery cannulation. Its use in pediatric cardiac surgery has seen a rise [1]. Herein, we describe the technique for innominate artery cannulation in pediatric patients undergoing redo sternotomy and review our experience with the technique.
文摘Background: Retrosternal goiters (RG) are those lesions extending to occupy the thoracic cavity. They carry a surgical risk due to distorted anatomy, the minimal access, and the potential for great vessels or pleural injury. No other effective therapeutic alternative to surgery exists. Cervicotomy is still the surgical approach of choice, although a form of sternotomy may always be necessary for field extension and safe gland delivery. Materials and Methods: This is a single institution combined retrospective & prospective study including retrospective analysis of all cases presenting to the NCI, Cairo University with RG candidate for surgery between Jan. 2008 until the end of Dec. 2012, and a prospective study of all cases with the same presentation presenting to the NCI between Jan. 2013 until the end of Dec. 2015. Data was collected from archive of patients at the statistical department. Aims: To study the clinico-pathological characteristics, the presentation, work-up, surgical approaches and postoperative complications of RG. Results: 42 patients were included & were divided into benign (34 patients, 80.9%) and malignant groups (8 cases, 19.1%). All patients (100%) were adults ranging (19 to 73 years) with mean 53.1 years. There was a female predominance (36 female, 85.7%) versus (6 males, 14.3%). Median duration of symptomatology was 23 months ranging (6 - 53 months). 23 patients (54.7%) were symptomatic while 19 cases (45.3%) accidently discovered. Mean tumor size was 9.97 cm in the benign group and 11.1 cm in the malignant group. 31 patients (73.8%) were euthyroid, 9 (21.4%) were thyrotoxic and 2 (4.7%) were hypothyroid. All patients (100%) underwent total thyroidectomy. The commonest approach was cervicotomy (33 cases, 78.6%), while a type of sternotomy was done in 9 cases (21.4%). 2 cases (4.7%) received postoperative radiation therapy & 4 cases (9.5%) received postoperative radioactive iodine. No perioperative mortality occurred & the overall morbidity was 6 cases (14.2%) in the benign group and 2 cases (4.7%) in the malignant group (4.7%). The median follow up period was 17.5 months. The median overall survival (OS) was 39.4 months and the median disease free survival (DFS) was 9.8 months for the malignant group. Conclusion: Cervicotomy is a safe favorable approach to remove a RG. Intraoperative field extension up to a form of sternotomy may be necessary for gland delivery with increasing operating time, hospital stay and morbidity. Postoperative morbidity is mainly due to the respiratory, recurrent laryngeal nerve palsy and hypoparathyroidism which is mainly increased when sternotomy is performed.
