Abstract: Objective To examine the cell viability and hemodynamic functions of the stented homograft valves preserved in liquid nitrogen. Methods Cell viability of the stented homograft valve preserved in liquid nitrogen after 3 months of preservation (experimental group，n=6) was examined using flow cytometer. Fresh homografts served as control group (n=6). We prepared three sorts of stented homograft valve(21#, 23#, 25#) preserved by liquid nitrogen. In vitro pulsatile flow tests were performed on valves of two groups. Effective opening area EOA),transvalve pressure gradient and regurgitation ratio were recorded at various flow volume, and compare with Perfect bioprosthetic valve. Results The results revealed that the death ratio of endothelial cell was 10.24%±1.71% in the experimental group, and 9.09%±2.72% in the control group (P=0.441). The death ratio of smooth muscle cell was 8.76%±1.82% in the experimental group, and 7.84%±0.59% (P=0.178) in the control group. The death ratio of total cell was 8.79%±1.44% in the experimental group, and 7.40%±0.49% in the control group (P=0.072). There were no significantly differences between two groups. The transvalve pressure gradient of two groups of valve depended on the flow volume, and increased with the flow volume increasing. The transvalve pressure gradient of the stented homograft valve was higher than that of Perfect valve. Regurgitation ratio of the stented homograft valve was bigger than Perfect valve’s. EOA had an increasing character when flow volume increased. EOA of the stented homograft valve was smaller than that of Perfect valve’s. Conclusion Liquid nitrogen can offer the benefit of cell viability of the stented homograft bioprosthetic valves. The stented homograft valve has salisfactory hemodynamic functions.
Objective To summarize the critical point of diagnosis and endovascular repairment (EVR) to thoracic aortic aneurysm (TAA), thoracic pseudoaneurysm (TPA) and aortic dissection (AD), by comparison the computerized tomography angiography (CTA) images before and after EVR to observe effects, so as to explore a unique index of imageology to assess the pathological development and evaluate therapeutically effect in dynamic and systemic reviews in pre, intra, postEVR and followup period. Methods Fortyeight patients involving aneurysm or dissection of thoracic aorta were treated with EVR based on the preoperative CTA imaging. Before and after the introducing of stentgraft, digital substation angiography (DSA) was taken place and sequential enhanced CTA was followed to evaluate the effects of the treatment. All imagings of CTA and DSA were collected and induced into e-FilmTM database to select key sections for analyses and measurement. Results Fortynine EVR were preformed and 54 stent grafts were implanted in 48 cases, with endothelial tears sealed in 42 cases of dissection, aneurismal cavities excluded in 2 cases of aortic aneurysm, and rupture site closed in 4 cases of pseudoaneurysm. Endoleakage happened in 9 cases, which were treated successfully by appropriate measures. One case suffered hemorrhage from introducing artery (iliac) which was controled by surgery, but he died of disseminated intravascular coagulation and then multiple organs failure. Fortyseven cases were followed up in 6-51 months with a satisfied clinical effect. Conclusion EVR is favorable in the effect of repairment to true, false and dissection of thoracic descending aorta. Chest pain and CTA scan is the key of early diagnosis of aortic dissection. Certain sections and leftanterior oblique viewing are the crucial profile for assessment and evaluation before and after operation.
ObjectiveTo determine the influence of proximal aneurysm neck anatomy on typeⅠA endoleak follo-wing endovascular aortic aneurysm repair (EVAR) for infrarenal abdominal aortic aneurysm. MethodsFrom September 2007 to February 2014, 111 consecutive patients with non-ruptured abdominal aortic aneurysms were treated with EVAR. The preoperative CTA of abdominal aortic was obtained by every patient, and the three-dimensional imaging was reconstructed and measured by software of Osorix. Then, the relation between the recurrence of typeⅠA endoleak and the concerned data measured by Osorix was analyzed by the statistical software. ResultsThe recurrence of typeⅠA endo-leak was related to the proximal neck angle of the abdominal aortic aneurysm, which weren't related to the proximal neck diameter and variation rates, the mural thrombas and calcification rate, and the maximum diameter of abdominal aortic aneurysm by multivariate analysis. ConclusionsThe complicated proximal aneurysm neck anatomy is a major cause for the typeⅠA endoleak, the proximal neck angle of the abdominal aortic aneurysm is the independent factor. The applica-tion of EVAR depends largely on the shape of the proximal aneurysm neck.
This study aims to investigate whether displacement force on stents can accurately represents the displacement of the stent after endovascular aneurysm repair (EVAR) by comparing the measured stent displacement with the displacement forces calculated by computational fluid dynamics (CFD). And the effect of cross-limb and parallel-limb EVAR on stent displacements is further studied. Based on our objective, in this study, ten cross-limb EVAR patients and ten parallel-limb EVAR patients in West China Hospital of Sichuan University were enrolled. Patient-specific models were first reconstructed based on the computed tomography angiography images, then the stent displacements were measured, and the displacement forces acting on the stents were calculated by CFD. Finally, the \begin{document}$ \mathrm{cos}\;\alpha $\end{document} value of the angle between the displacement force and the displacement vector was used to analyze the matching degree between the displacement and the displacement force. The results showed that the displacement forces on cross-limb stents and parallel-limb stents were (2.67 ± 2.14) N and (1.36 ± 0.48) N, respectively. Displacements of stent gravity center, stent displacements relative to vessel, and vessel displacements of cross-limb and parallel-limb stents were (4.43 ± 2.81) mm and (6.39 ± 2.62) mm, (0.88 ± 0.67) mm and (1.11 ± 0.71) mm, (3.55 ± 2.88) mm and (5.28 ± 2.52) mm, respectively. The mean \begin{document}$ \mathrm{cos}\;\alpha $\end{document} for cross-limb and parallel-limb stents were 0.02 ± 0.66 and − 0.10 ± 0.73, respectively. This study indicates that the displacement force on the stent can’t accurately represent the displacement of the stent after EVAR. In addition, the cross-limb EVAR is probably safer and more stable than the parallel-limb EVAR.
Objective To evaluate the efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) combined with gastric coronary vein embolization for the treatment of liver cirrhosis with gastroesophageal varices hemorrhage, and evaluate its application value. Methods The data of 50 patients with liver cirrhosis who were treated with TIPS combined with gastric coronary vein embolization between June 2009 and January 2013 were retrospectively analyzed. According to Child-Pugh Liver Grade, the patients were divided into grade A liver function group (n=6), grade B liver function group (n=18), and grade C liver function group (n=26); according to the type of stent implantation, the patients were divided into covered stent group (n=29) and bare stent group (n=21). The 1-week and 1-, 3-, 6-, and 12-month postoperative liver function changes were compared, and the 2-year postoperative rebleeding rate, survival rate, stent restenosis rate, and hepatic encephalopathy incidence were observed. Results The success rate of surgery was 100.0% (50/50), and the success rate of emergency surgery was 100.0% (3/3) in 3 patients with active bleeding. The portal vein pressure decreased from (39.46±2.82) cm H2O (1 cm H2O=0.098 kPa) before the surgery to (25.62±2.13) cm H2O after the surgery, and the difference was statistically significant (P<0.05). In grade A and grade B liver function groups, and covered stent and bare stent groups, the differences between preoperative and postoperative liver function indexes were not statistically significant (P>0.05); in grade C liver function group, the 1-week, 1-month, 3-month postoperative values of alanine aminotransferase, aspartate aminotransferase, total bilirubin and direct bilirubin increased compared with the preoperative values, and the differences were statistically significant (P<0.05). The postoperative 2-year rebleeding rate was 12.0% (6/50), and the postoperative 2-year incidence of hepatic encephalopathy was 16.0% (8/50). The postoperative 2-year stent stenosis rate was 26.0% (13/50) in the 50 cases, which was 13.8% (4/29) in covered stent group and 42.9% (9/21) in bare stent group, respectively. The postoperative 2-year survival rate was 90.0% (45/50). Conclusions TIPS combined with gastric coronary vein embolization in the treatment of liver cirrhosis with gastroesophageal varices bleeding has the exact effect, low rebleeding rate, fewer complications, and can be repeated. The preoperative evaluation of patients’ liver function, the application of stent of diameter 8 mm, paying attention to the perioperative period and regular follow-up treatment are helpful to reduce or prevent the occurrence of hepatic encephalopathy, stent stenosis and other complications.
Objective To evaluate initial experience with shape memory alloy stent as an alterative to colostomy in patients with intestinal obstruction of rectal cancer. Methods Twenty-one patients with acute and chronic rectal obstructions from malignant causes underwent stent placement. After rectal stent was slenderized in ice water, it was inserted into the strictured rectum by hand or sigmoidoscope. Nitinol mesh stent were deployed in hot water. Results Eighteen patients who had underwent rectal stent placement achieved clinical decompression within 5 hours. Colostomy underwent in 3 patients due to stent failure. Eighteen patients with stent were followed-up, 14 cases died in 56-720 days and 4 other cases were still alive without intestinal obstruction in 2-15 months. Conclusion Nitinol mesh stent may be useful in the management of terminal or high-risk surgical patients for palliative purposes shuning colostomy. Palliation of stent combined with chemotherapy and immunotherapy can be performed to improve survival.
Objective To investigate the feasibility and effect of stentedpulmonary autograft replacement and find out the best way to treat mitral valve diseases. Methods From August 2006 to October 2007, 20 male sheep at the age of about 1 year old underwent mitral valves replacement operation in Anzhen Hospital. Weight of these sheep was 50.0±6.0 kg. They were randomly divided into two groups. Ten sheep in the experimental group underwent RossⅡsurgery in which we first sutured pulmonary valve onto a pulmonary valve stent, transferred the valve to the mitral valve annulus and then reestablished the outflow tract of the right ventricle. The other 10 sheep in the control group underwent bioprosthetic valve replacement routinely. Ultrasonic cardiogram (UCG) was employed 6 hour after operation to measure the effective orifice area (EOA) of the mitral valve, mitral peak velocity of early filling, the peak pressure gradient (PPG), the extent of regurgitation, left ventricular enddiastolic dimension (LVEDD) and ejection fraction (EF). Results One sheep in the experimental group died of low cardiac output syndrome; one in the control group died of unmanageable bleeding during operation, and the others all survived. Six hours after operation, UCG of the experimental group showed that the heart valves were well fixed, valve echo was clear, and there was no perivalvular leakage or mitral valve stricture or regurgitation, but moderate pulmonary valve regurgitation occurred in 1 case and mild in 2. There was no significant difference between the two groups in PPG (11.86±1.28 mm Hg vs. 10.98±0.98 mm Hg,t= 1.670,P=0.110) and the mitral peak velocity of early filling (1.72±0.09 m/s vs. 1.65±0.07 m/s, t=1.680,P=0.110). However, EOA of the experimental group was smaller than the control group (2.23±0.09 cm2 vs. 2.39±0.08 cm2, t= 4.240,P= 0.001). Conclusion The experimental result of sheep mitral valves replacement with stentedpulmonary autograft is satisfying. The new mitral valves work well and the surgery method is feasible.
ObjectiveTo summarize clinical experience and surgical indications of open stented elephant trunk (sET) procedure for the treatment of complex acute Stanford type B aortic dissection (AD). MethodsFrom February 2009 to April 2013, 25 patients with complex acute Stanford type B AD underwent open sET procedure in Beijing Anzhen Hospital. There were 22 male and 3 female patients with their age of 46.92±9.12 years (range, 30 to 66 years). There were 16 patients with hypertension and 3 patients with preoperative acute renal failure. All the patients received sET implantation via an aortic arch incision under deep hypothermic circulatory arrest. Concomitant procedures included extra-anatomic bypass grafting in 11 patients, Bentall procedure in 1 patient, aortic valve replacement in 3 patients, and ascending aorta plasty in 3 patients. Computed tomography angiography (CTA) was performed before discharge and during follow-up for all the patients. ResultsOperation time was 4-7 (5.5±0.7) hours, cardiopulmonary bypass time was 93-206 (137.64±30.02) minutes, aortic cross-clamping time was 28-109 (57.96±21.05) minutes, and selective cerebral perfusion time was 15-76 (26.76±11.88) minutes. There was no in-hospital death. Postoperatively, there were 2 patients with pulmonary complications, 2 patients with type I endoleak, 1 patient with acute renal failure, 1 patient with temporary neurological disorder, 1 patient with sudden ventricular fibrillation, and 1 patient with delayed wound healing. Mean follow-up time was 6-54 (25.76±16.15) months, and 2 patients were lost during follow-up. The follow-up rate was 92%.There was no late death during follow-up. ConclusionsOpen sET procedure is a reliable and efficacious therapeutic strategy for patients with complex acute Stanford type B AD. Surgical indications include complex Stanford type B AD without enough landing zone, type B AD with ascending aortic disease, aortic root disease, valvular heart disease, coronary artery disease and congenital heart defects, and type B AD caused by genetic connective tissue disorder.
Objective To investigate the security and efficiency of endovascular repair for Stanford type B aortic dissection (AD) with severe complications. Methods Between January 2003 and December 2009, 60 patients having Stanford type B AD with severe compl ications were treated, including 39 males and 21 females with an average age of 43.7 years (range, 34-71 years). Severe compl ications included 27 cases of huge hemothorax, 1 case of paraplegia, 7 cases of acute renal failure,10 cases of cel iac trunk ischemia, 10 cases of superior mesenteric artery ischemia, and 5 cases of severe limb schemia. Emergency stent-graft deployment were appl ied in all patients, and 64 stent-grafts were successfully implanted. Results All patients survived and were followed up 3-86 months. Hemothorax disappeared after 28 days to 3 months of operation in all hemothorax patients; renal function returned normal after 1 to 9 days; l imb and visceral ischemia disappeared gradually after 1 to 14 days; and muscular strength of lower limb in the paraplegia patient began to recover after 4 hours of operation. The postoperative CT angiography showed enlarged true lumen and thrombosis in the false lumen. Conclusion Emergency endovascular repair is a safe and effective method to treat Stanford type B AD with severe complications.
ObjectiveTo investigate the value of different minimally invasive surgical techniques, stent placement, laparoscopic surgery, and sustained-releasing 5-fluorouracil, in solving intestinal obstruction due to colorectal cancer. MethodsFrom May 2000 to May 2010, total 68 patients with obstructed colorectal cancers in three centers were treated in two ways in terms of the stage: The first, patients with resectable tumors underwent colorectal stent placement as a ‘bridge to surgery’ guided by enteroscope under X-ray. After clinical decompression and bowel preparation, laparoscopic radical resection was performed. The second, patients with unresectable tumors underwent rectal stent placement just for palliation. Sustained-releasing 5-fluorouracil was implanted into the local cancerous intestinal tract through stent walls. ResultsFifty-one of 52 patients underwent laparoscopic radical resection successfully following stent placement, while one failed and died during follow-up 93 d postoperatively. Forty patients with successful laparoscopic surgery were followed up in 3 to 36 months (with an average of 15 months) without tumor planting in the incision, postoperative local recurrence or anastomotic stricture. Fifteen unresectable patients and one high-risk, intolerable patient underwent rectal stent placement and implantation of sustained-releasing 5fluorouracil. During follow-up 3 to 24 months (with an average of 14 months), 11 died, who survived for (350±222) d (range 101-720 d), and 5 were still alive for 3 to 13 months (with an average of 9 months) without intestinal obstruction. ConclusionsLaparoscopic surgery combined with stent placement is an effective and safe procedure for resectable obstructed colorectal cancer. For unresectal obstructed rectal cancer, rectal stent placement combined with sustained-releasing 5-fluorouracil can prolong survival time avoiding colostomy.