Aortic valve replacement: the experiences of 1026 cases / 中华外科杂志

<p><b>OBJECTIVE</b>To study the changes in pathogenic causes and the prognosis of aortic valve replacement (AVR).</p><p><b>METHODS</b>The clinical data of 1026 patients undergoing AVR from December 1980 to December 2006 were analyzed retrospectively. The mortality, morbidity, changes in pathogenic causes and risk factors were analyzed.</p><p><b>RESULTS</b>The postoperative mortality and complication morbidity were 4.3% and 10.6% respectively within 30 days followed operation. Main causes of operative death were heart failure, multi organ failure and endocarditis. The major risk factors for operative death were left ventricle ejection fraction less than 0.4, endocarditis, valve regurgitation and emergency operation before AVR. Late mortality was 0.54% patient-year (3.4%), most of whom died of heart failure, endocarditis and arrhythmias. Patients underwent reoperation 0.22% patient-year (1.4%), with the causes of endocarditis and perivalvular fistula.</p><p><b>CONCLUSIONS</b>Morbidity of rheumatic damage in aortic valve has decreased, while valve degeneration has increased gradually in the recent years. Avoiding prosthesis-patient mismatch, good postoperatively guide and prevention of endocarditis can improve the prognosis of AVR.</p>

Experiences on surgical treatment of severe aortic valve stenosis: a report of 171 cases / 中华外科杂志

<p><b>OBJECTIVE</b>To analyze the experiences on surgical treatment of severe aortic valve stenosis.</p><p><b>METHODS</b>From December 1990 to December 2006, 171 patients with severe aortic valve stenosis underwent aortic valve replacement (AVR). There were 135 males and 36 females aged from 10 to 75 years old, with a mean of (45.8 +/- 15.6) years old. The intervals between the first episode of exertion dyspnea and administration to operation were 2 months to 52 years. The pathological lesions of the group were rheumatic aortic valve stenosis in 75 cases, calcified aortic stenosis in 66 cases, bicuspid aortic valve in 26 cases and other congenital aortic valve stenosis in 4 cases. One hundred and twenty-four patients underwent AVR, 7 AVR combined with replacement of the ascending aorta, 5 AVR with coronary artery bypass grafting, 19 AVR with mitral valve plasty (MVP), 8 AVR with plasty of the ascending aorta and 8 AVR with enlargement of the aortic root.</p><p><b>RESULTS</b>The averaged operation time was (4.4 +/- 0.6) h. Cardiopulmonary bypass (CPB) time was (124.7 +/- 38.5) min and the aorta clamp time was (78.3 +/- 21.7) min. The averaged blood loss during operation was (754.5 +/- 518.4) ml. All the procedures were successfully performed and all patients were weaned off CPB uneventfully. The indication of early complications was 12.3% (21/171), including low cardiac output syndrome in 7 cases, multi-organ failure in 3 cases, endocarditis in 1 case, renal dysfunction in 4 cases, ventricular fibrillation in 1 case, excessive bleeding in 2 cases, III atrial-ventricular block in 2 cases, and mediastinal infection in 1 case. The total mortality was 5.8% (10/171) with the main causes as cardiac failure for 4 cases, arrhythmia for 1 case, multi-organ failure for 4 cases, and infectious endocarditis for 1 case.</p><p><b>CONCLUSIONS</b>Successful management of severe aortic valve stenosis requires sophisticated surgical techniques and experienced peri-operative care. Satisfactory results can be achieved if valve replace surgery is performed adequately.</p>

Study on expression of mineralocorticoid receptor in human atria during atrial fibrillation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the mRNA and protein expression of mineralocorticoid receptor (MR) in patients with atrial fibrillation.</p><p><b>METHODS</b>Twenty-five patients with rheumatic heart valve disease, 12 in sinus rhythm and 13 in chronic atrial fibrillation (>or= 6 months), underwent transthoracic echocardiography and right and left atrial lateral wall tissue samples were obtained from these patients during mitral/aortic valve replacement operation. Realtime quantitative PCR and Western blot were used to determine the mRNA and protein expression of MR in atria specimens. The distribution of MR in human atria was analyzed by specific immunohistochemical staining.</p><p><b>RESULTS</b>The left atrial diameters increased markedly in atrial fibrillation group compared with that in sinus rhythm group (P<0.01). And the results showed that the level of mRNA and protein of MR were increased significantly in atrial fibrillation group compared with those in sinus rhythm group (P<0.01 or 0.05), whereas the expression of mRNA and protein of MR were found to be no difference between left atria and right atria both in fibrillation and sinus groups (all P>0.05). The special immunohistochemical staining demonstrated that MR was abundant in the human atrial myocardium and MRs were located mainly in the cytoplasm of atrial cells, which were more evident in atrial fibrillation group than those in sinus rhythm group.</p><p><b>CONCLUSION</b>These findings suggested that MRs were upregulated in atrial fibrillation and aldosterone antagonists may be effective in treating atrial fibrillation.</p>

Evaluation of surgical technique and indication on descending aortic aneurysms / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the surgical technique and indication on descending aortic aneurysms.</p><p><b>METHODS</b>From January 1996 to June 2006, 41 patients with descending aortic aneurysm underwent operation, including DeBakey type III dissection in 26, false aneurysm in 6, true aneurysm in 4, and residual or newly complicated type III dissection after the surgery of Marfan syndrome in 5. Operations were performed by left heart bypass in 9, femoral-femoral bypass in 7, pulmonary-femoral bypass in 2, and deep hypothermic circulatory arrest in 23. The whole thoracic descending aorta was replaced in 15, and intercostal arteries were reimplanted in 12.</p><p><b>RESULTS</b>One patient died of acute renal failure with the hospital mortality 2.4%. Main complications: respiratory dysfunction in 6, renal dysfunction in 6, recurrent nerve injuries in 4, chylothorax in 2, and no paraplegia.</p><p><b>CONCLUSIONS</b>Surgical intervention of descending aortic aneurysm still has its unique advantages and indications; surgical safety is markedly improved by the use of deep hypothermic circulatory arrest.</p>

Impact of different brain protection techniques upon postoperative temporary neurological dysfunction in aortic surgery with the aid of deep hypothermic circulatory arrest / 中华外科杂志

<p><b>OBJECTIVE</b>To assess impact of different brain protection techniques upon postoperative temporary neurological dysfunction in aortic surgery with the aid of deep hypothermic circulatory arrest.</p><p><b>METHODS</b>From January 2003 to December 2005, 78 patients who met the inclusion criteria entered the present cohort, 43 of whom were under the aid of deep hypothermic circulatory arrest plus retrograde cerebral perfusion (RCP group) and the other 35 under deep hypothermic circulatory arrest plus selective antegrade cerebral perfusion (SCP group). The present and grades of postoperative temporary neurological dysfunction were assessed by independent observers with the same criterion. The impact of duration of deep hypothermic circulatory arrest upon the postoperative temporary neurological dysfunction was also evaluated.</p><p><b>RESULTS</b>The incidence of postoperative temporary neurological dysfunction was significantly higher in the RCP group than in the SCP group (15, 34.9% vs. 4, 11.4%, P<0.05). And long duration of deep hypothermic circulatory arrest (more than 50 min) has a negative impact on the postoperative temporary neurological dysfunction rate.</p><p><b>CONCLUSIONS</b>Applying selective antegrade cerebral perfusion as the brain protection technique and shortening the duration of deep hypothermic circulatory arrest can reduce the incidence of temporary neurological dysfunction and preserve cerebral function more effectively.</p>

Diagnosis and surgical management of primary cardiac neoplasms / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To review and summarize the experience in diagnosis and surgical management of primary cardiac neoplasms.</p><p><b>METHODS</b>112 patients with primary cardiac neoplasms were treated surgically from Jan. 1980 to Jan. 2005. Those tumors were grouped into three categories: myxomas (98), benign nonmyxomas (3), and malignant tumors (11). Five of 11 malignant tumor patients underwent biopsy or palliative operation, the other patients received complete excision. Mitral valve replacement were done simultaneously in 2 of these patients, mitral valve repair in 4 and tricuspid valvoplasty in 33. All patients' diagnosis was confirmed by echocardiography.</p><p><b>RESULTS</b>108 patients survived the operation and 4 patients died postoperatively. The hospital mortality was 3.6% (4/112). Two patients developed poor left ventricular function postoperatively and died at the third and the seventh postoperative day due to low cardiac output. One patient developed and died of progressive hepatic and renal function failure postoperatively. Another one patient died of severe arrhythmia. Mean follow-up of 76 myxoma patients who are still alive was 6.4 years (range, 3 month to 17 years). Fifty-five patients still had heart function in New York Heart Association class I and 21 in class II at the end of follow-up without any evidence of recurrance. The follow-up results of benign nonmyxomas were similar to those of myxomas. Mean follow-up of all survived malignant tumor patient was 6 months (range, 2 months to 12 months). Ten of them died of recurrence or metastasis within 1 year postoperatively except only one still alive.</p><p><b>CONCLUSION</b>Surgical resection, whenever possible, is the first treatment choice for all kinds of primary cardiac tumors. Surgical resection of myxoma and benign nonmyxoma can give excellent long-term results which may lead to eventual cure of myxoma and benign nonmyxoma. For malignant tumor patient, surgical treatment is only palliative and to prolong the life of patients.</p>

Study of adenovirus-mediated vascular endothelial growth factor 165 gene transfer into bone marrow stromal cells and its expressive product promoting proliferation of endothelial cells / 中华外科杂志

<p><b>OBJECTIVE</b>To study transcription, expression, and bioactivity of expressive protein of vascular endothelial growth factor 165 (VEGF(165)) gene, after bone marrow stromal cells (BMSCs) were transferred by VEGF(165) gene mediated by adenovirus vector ex vivo.</p><p><b>METHODS</b>BMSCs were Isolated and cultured by gradient centrifugation method. The cells cultured are transferred by recombinant adenovirus vector that carry VEGF(165) gene. Transcription and expression of VEGF(165) gene in BMSCs and secretion of VEGF protein in culture medium were measured by reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot and enzyme linked immunosorbent assay (ELISA) methods. The activity of VEGF protein in culture media was detected by proliferation effects on vascular endothelial cells.</p><p><b>RESULTS</b>When Ad. VEGF(165) transferred into BMSCs, there was an effective transcription and expression. The expressed product in the media of transferred cells had highly biological activity on proliferation of rat aortic vascular endothelial cells (P < 0.01).</p><p><b>CONCLUSIONS</b>Adenovirus vector can be transferred into BMSCs efficiently and safely. Adenovirus mediated VEGF(165) gene transferred into BMSCs could express VEGF protein with highly biological activity, which provided foundation on BMSCs based gene therapy for ischemic disease.</p>

Electrophysiologic study of f-wave amplitude in chronic atrial fibrillation associated with rheumatic heart disease / 第二军医大学学报

To investigate the electrophysiologic characteristics of f-wave amplitude and to evaluate its role in development and persistence of chronic atrial fibrillation (AF) associated with rheumatic heart disease (RHD). Methods: Epicardial mapping was performed in 44 patients with chronic AF of RHD who underwent heart valve surgery. Ten patients with supraventricular tachycardia served as the control group. Results:The f-wave amplitude of left atrium (LA) and middle and low LA posterior regions were significantly lower than those of the control group. The f-wave amplitudes of the upper, middle and low sections in LA posterior region were significantly lower than those in right atrium (RA) (P<0.05). The f-wave amplitudes were compared before and after electrocardioversion in 14 patients with chronic AF. The mean atrial electrogram amplitude during sinus rhythm was significantly higher than that during AF (P<0.01).The f-wave amplitude in left appendage was higher than that in LA posterior region (the upper,middle and the lower part),P<0.05.The f-wave amplitude in the upper section of LA was significantly higher than that in the middle section. The f-wave amplitude in AF group was not correlated to the diameter or volume of both atria. Conclusion: There are amplitudes differences between the upper, middle and lower LA,suggesting that the middle and lower sections of LA posterior wall may be the region producing anisotropy and reentrant circle.

Electrophysiologic study of f-wave amplitude in chronic atrial fibrillation associated with rheumatic heart disease / 第二军医大学学报

To investigate the electrophysiologic characteristics of f-wave amplitude and to evaluate its role in development and persistence of chronic atrial fibrillation (AF) associated with rheumatic heart disease (RHD). Methods: Epicardial mapping was performed in 44 patients with chronic AF of RHD who underwent heart valve surgery. Ten patients with supraventricular tachycardia served as the control group. Results:The f-wave amplitude of left atrium (LA) and middle and low LA posterior regions were significantly lower than those of the control group. The f-wave amplitudes of the upper, middle and low sections in LA posterior region were significantly lower than those in right atrium (RA) (P<0.05). The f-wave amplitudes were compared before and after electrocardioversion in 14 patients with chronic AF. The mean atrial electrogram amplitude during sinus rhythm was significantly higher than that during AF (P<0.01).The f-wave amplitude in left appendage was higher than that in LA posterior region (the upper,middle and the lower part),P<0.05.The f-wave amplitude in the upper section of LA was significantly higher than that in the middle section. The f-wave amplitude in AF group was not correlated to the diameter or volume of both atria. Conclusion: There are amplitudes differences between the upper, middle and lower LA,suggesting that the middle and lower sections of LA posterior wall may be the region producing anisotropy and reentrant circle.

Surgical interventions for complex native valve endocarditis / 中华外科杂志

<p><b>OBJECTIVE</b>To elucidate the early and long-term results of surgical treatment for complex infective endocarditis with prosthetic valve replacement.</p><p><b>METHODS</b>Fifty-seven patients of complex native valve endocarditis, including 25 cases of aortic valve, 16 of mitral valve and 16 of double valves, who underwent operative interventions with prosthetic valve replacement between December 1988 and June 2002, were analyzed retrospectively. Intraoperative findings demonstrated aortic annular abscesses (n = 19), root abscesses (n = 4), mitral posterior annular abscesses (n = 11), myocardial abscesses (n = 6), massive leaflet destruction (n = 32) and valvular vegetations (n = 55). Complex reconstruction of the aortic and mitral annulus was required in 35 patients. Associated procedures included Bentall's procedure (n = 4), aortic valve replacement (n = 21), mitral valve replacement (n = 16) and double valve replacements (n = 16).</p><p><b>RESULTS</b>The operative mortality was 11%. Complications included low cardiac output syndrome, recurrence of endocarditis, multiple organ failure, ventricular arrhythmia, bleeding, mediastinal infection, respiratory insufficiency and heart block. Follow-up was 100% complete at a mean of 5.93 years. There were five late deaths (3 prosthetic valve endocarditis, 2 valve-related). The NYHA functional status recovered to Class I in 17 patients, Class II in 27 and Class III in 2 at 1 year follow-up. Kaplan-Meier analysis showed the 5-year actuarial freedom from reoperation was (84 +/- 3)%, and actuarial survivorship at 5 years was (61 +/- 9)%.</p><p><b>CONCLUSIONS</b>Urgent or even emergency operation is advocated for complex infective endocarditis. Proper intraoperative reconstruction of the aortic and mitral annulus and optimized perioperative management, especially the strategy for prevention of recurrent endocarditis, are of great importance in achieving satisfied early and long-term clinical outcomes.</p>

Congenital coronary artery fistulae in adults: diagnosis and surgical treatment / 中华外科杂志

<p><b>OBJECTIVE</b>To summarize the clinical characteristics, diagnosis and surgical in-treatment results of congenital coronary artery fistulas (CAF) in adults.</p><p><b>METHODS</b>Fourteen patients (8 men, 6 women), aged from 18 to 60 years with a mean of 32 +/- 13 years, underwent surgical correction of CAF between March 1985 and April 2002. Eleven of the 14 patients (78.57%) were symptomatic. The diagnosis of CAF was made by echocardiography or angiocardiography preoperatively. The fistulae originated from the right, left and double coronary arteries in 10 (71%), 3 (21%) and 1 (7%) patient(s), respectively. The fistulae drained into the right ventricle (8 patients), left ventricle (4), right atrium (1) and pulmonary artery (1), respectively. The diameter of fistulae ranged from 0.30 to 1.80 cm with a mean of (1.16 +/- 0.49) cm. There were 6 CAF patients associated with coronary artery aneurysms and 4 CAF patients with other coexisting cardiac defects. The distal fistulae were closed in 10 patients with cardiopulmonary bypass (CPB) and 4 patients without CPB. The coexisting defects were corrected simultaneously.</p><p><b>RESULTS</b>There was no early and late death. One patient had low cardiac output syndrome and cured during early postoperative period. Twelve patients (85.71%) were followed up for a mean period of 3.35 +/- 4.28 years without myocardial ischemia or infarction and recurrent fistulae. Heart function was improved to NYHA functional class I in 11 patients and class II in 1 patient.</p><p><b>CONCLUSIONS</b>All adult patients with CAF who have demonstrable hemodynamic and cardiovascular morphological changes should be surgically treated as early as possible. The appropriate surgical management and reliable myocardial protection are key points of good surgical results.</p>

Long-term results of mitral-aortic valve replacement in 1,154 patients with rheumatic valvular disease / 中华外科杂志

<p><b>OBJECTIVE</b>To analyze the early and long-term results after mitral-aortic valve replacement for rheumatic valvular disease and the determinant factors involved and subsequent therapies.</p><p><b>METHODS</b>1 154 patients receiving combined mitral-aortic valve replacement for rheumatic valvular disease from May 1981 to May 2001 were reviewed. The mean age of the patients was 41.48 +/- 10.00 years. Concomitant valve plasty was performed for associated tricuspid organic or significant functional lesions. Lateral tilting disc or bileaflet valve prostheses were used for replacement. New York Heart Association functional status showed Class III or IV in 91.77% of the patients. Moderate to severe pulmonary hypertension occurred in 29.38% of the patients. The duration of follow-up varied from 8 months to 20 years.</p><p><b>RESULTS</b>The hospital mortality was decreased from 6.50% to 4.45%. The 5-, 10- and l5-year survival rates were 89.46% +/- 1.35%, 86.50% +/- l.91% and 67.86% +/- 6.16%, respectively. The 5-, 10- and l5-year thromboembolic event free rates were 97.80% +/- 0.74%, 88.31% +/- 2.20% and 94.08% +/- 2.29%, respectively. the 5-, 10- and l5-year anticoagulant related bleeding free rates were 94.80% +/- 1.09%, 89.32% +/- 2.10% and 83.12% +/- 3.57% respectively. Cardiac functional status returned to Class II in 98% patients and to Class III in 2% during follow-up.</p><p><b>CONCLUSIONS</b>Both left and right ventricular functions may be impaired as a result of rheumatic valvular disease. Tricuspid valve should be explored during surgery and any significant tricuspid annular enlargement and regurgitation showed be corrected in concomitance. Long-acting penicillin regimen is needed for 3 - 5 years for the prevention of rheumatic fever relapse. A low intensity anticoagulant regimen after valve replacement with prothrombin time targeting at 1.5 - 2.0 times is advisable in lessening anticoagulant related bleeding yet optimizing sufficient prevention against thromboembolic complications.</p>

Long-term results of prosthetic mitral valve replacement with home-made tilting disc valve: a report of 125 cases / 中华外科杂志

<p><b>OBJECTIVE</b>To analyze the early and long-term results after mitral valve replacement for rheumatic valvular disease by using home-made tilting disc valve, and the determinant factors involved and subsequent therapies.</p><p><b>METHODS</b>One hundred and five patients, including 31 patients with rheumatic mitral stenosis, 92 patients with mixed mitral stenosis and regurgitation, and 2 patients with bacterial endocarditis, underwent prosthetic mitral valve replacement with home-made tilting disc valve from September 1978 to June 1982. Three patients had a history of mitral commissurotomy, and 5 patients had concomitant functional tricuspid regurgitation. All patients were operated on under cardiopulmonary bypass with implantation of 25 - 29 mm size home-made tilting disc valve prosthesis. The associated functional tricuspid lesions were treated at the same time with modified DeVega's valvuloplasty or Kays bicuspidate valvuloplasty.</p><p><b>RESULTS</b>Eleven patients died during the hospital stay with an early operative mortality of 8.8%. The major causes of the early death were low cardiac output syndrome (4 patients), respiratory failure (2), acute renal failure (2), extrinsic prosthesis dysfunction (1), ventricular arrhythmia (1), and left ventricular rupture (1). Ninety-eight survivors were followed up (total 1,162.2 years) for mean duration of 12.8 years. Eighty-nine patients (78%) survived over 10 years after operation, 58 (51%) over 15 years, and 55 (48%) over 20 years. There were 16 late deaths due to heart failure, anticoagulation related bleeding, thromboembolism and recurrence of rheumatic fever. The survival rates at 10 and 20 years were 82.3% and 51.1% respectively. Among the patients who survived over 20 years, 37 patients had the cardiac functional status returned to Class II, 13 Class III, and Class IV.</p><p><b>CONCLUSIONS</b>Severe post-rheumatic valve deformity may occur in younger patients in China. Long-acting penicillin regimen given for 3 - 5 years for the prevention of rheumatic fever relapse is advocated. A low intensity anticoagulant regimen after mitral valve replacement is advisable in lowering the incidence of anticoagulant related bleeding, while optimizing sufficient protection against thromboembolic complication. Proper operative timing (e.g. when the patient is in sinus rhythm and in NYHA functional class II) is of great importance in achieving satisfied long-term results.</p>

Effect of terminal warm blood cardioplegia on the changes of tubulin in myocardial cells after hypothermic ischemia and reperfusion / 第二军医大学学报

Objective: To elucidate the possible mechanism responsible for the improved protection of terminal warm blood cardioplegia (TWBC) after hypothermic cardiopulmonary bypass (CPB) through analysis of tubulin (TB) components changes in myocardial cells exposed to TWBC. Methods: Stable animal models of CPB were established in cats, which were then randomly divided into 2 groups. Group Ⅰ was subjected to intermittent cold blood cardioplegia (ICBC) whereas group Ⅱ to ICBC followed by TWBC before uncross-clamping. Left ventricular performance was then monitored and evaluated by LVSP, LVEDP, ±dp/dtmax and t-dp/dtmax in both groups and semi-quantitive analysis was conducted with Western blot method as to the content and constitution of TB in myocardial cells at 15 min, 120 min after aortic crossclamping (ACC) and 5 min,15 min, 60 min,120 min after reperfusion. Results: Within 120 min after reperfusion, systolic and diastolic functions decreased significantly in group Ⅰ as compared with group Ⅱ(P<0.05). At 115 min after ACC and 15 min after reperfusion, the content of free and polymerized TB in both groups had no difference (P>0.05). At 120 min after ACC and 5 minutes after reperfusion, there was a significant difference between groupⅠ andⅡ (P<0.01). Conclusion: TWBC accelerates the repolymerization of myocardial TB during hypothermic CPB, which may mediate the improved cardiac performance in the early stage of myocardial reperfusion.

Effect of terminal warm blood cardioplegia on the changes of tubulin in myocardial cells after hypothermic ischemia and reperfusion / 第二军医大学学报

Objective: To elucidate the possible mechanism responsible for the improved protection of terminal warm blood cardioplegia (TWBC) after hypothermic cardiopulmonary bypass (CPB) through analysis of tubulin (TB) components changes in myocardial cells exposed to TWBC. Methods: Stable animal models of CPB were established in cats, which were then randomly divided into 2 groups. Group Ⅰ was subjected to intermittent cold blood cardioplegia (ICBC) whereas group Ⅱ to ICBC followed by TWBC before uncross-clamping. Left ventricular performance was then monitored and evaluated by LVSP, LVEDP, ±dp/dtmax and t-dp/dtmax in both groups and semi-quantitive analysis was conducted with Western blot method as to the content and constitution of TB in myocardial cells at 15 min, 120 min after aortic crossclamping (ACC) and 5 min,15 min, 60 min,120 min after reperfusion. Results: Within 120 min after reperfusion, systolic and diastolic functions decreased significantly in group Ⅰ as compared with group Ⅱ(P<0.05). At 115 min after ACC and 15 min after reperfusion, the content of free and polymerized TB in both groups had no difference (P>0.05). At 120 min after ACC and 5 minutes after reperfusion, there was a significant difference between groupⅠ andⅡ (P<0.01). Conclusion: TWBC accelerates the repolymerization of myocardial TB during hypothermic CPB, which may mediate the improved cardiac performance in the early stage of myocardial reperfusion.

A novel regulable sutureless aortic arch prosthesis:an experimental study / 第二军医大学学报

Objective:To develop a novel regulable sutureless aortic arch prosthesis and to apply it in an animal experimental study.Methods:The arch skeleton of the prosthesis was made of tandem Z-shape NiTiNOL wire;the branch skeleton was made of laser-cut NiTiNOL tube;and the whole skeleton was coated with thin ePTFE film.The blood vessel was anastomosed by di- rect ligature,needing no manual suturing.The prosthesis was applied in swine aortic arch operations under the bypass condi- tion.The practicality for surgery and the feasibility of anastomosis of the prosthesis were assessed.Results:Aortic arch opera- tions were successfully performed in 6 of the 8 experimental animals.The prostheses were easy to use,and the mean bypass time was only 10 min.The blood loss of the anastomoses was less than 100 ml within 8 h postoperatively in 5 animals;one had more blood loss due to prosthesis mismatch.Conclusion:The novel regulable sutureless aortic arch prosthesis has satisfactory practicality for surgery and reliable anastomosis,making it promising in future clinical application.

Cancer stem cells:current status / 第二军医大学学报

Recently,study on cencer stem cells has been a focus of study.Cancer stem cell is a small population of cencer cells possessing the properties of stem cells:self-renewal,differentiation and proliferation.To date,the existence of cancer stem cells has been proven in acute and chronic myeloid leukemia,breast cancer,brain tumors,liver cancer and colon cancer,etc..In this article we reviews the current progress on cancer stem cells,including the defination,existing evidence,research methods, and challenges in clinical application.