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.
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.
Objective To design a novel stentless porcine aortic bioprosthesis and test the feasibility and its function in vitro after the valve was implanted by a modified method. Methods Six stentless porcine aortic bioprosthesis were divided into two groups according to different implantation, single layer suture group: new improvement stentless porcine aortic bioprosthesis sutured with single layer was implanted; double layer suture group: stentless porcine aortic bioprosthesis developmented by our laboratory used double layer suture was implanted. Each group contained three scales: 23 mm ,25 mm and 27 mm. Analogue ex vivo aortic valve replacement was performed , the feasibility of the new implantation was detected. Effective orifice area, transvalvular pressure gradient and regurgitation ratio were recorded at the cardiac output of 2.0 L/min, 3.5 L/min, 5.0 L/min and 7.0 L/min under the guideline of International Organization for tandardization （ISO）5840. Results The average aortic valve implantation time used for single layer suture and tradition double layer suture were 50 min and 70 min respectively. The transvalvular pressure gradient in the single layer suture group were significantly lower than those in double layer suture group under the flow of 5.0 L/min in 23 mm valve and 27 mm valve （13.51±0.51 mm Hg vs. 14.44±0.99 mm Hg, 7.36±0.19 mm Hg vs. 7.53±0.28 mm Hg；P＜0.01）;and the effective orifice area in the single layer suture group were larger than those in double layer suture group in the same case(1.87±0.06 cm2 vs. 1.76±0.08 cm2, 2.26±0.07 cm2 vs. 2.16±0.05 cm2；P＜0.01). There was no statistically difference in other parameters between both groups. Conclusion The novel design of new improvement stentless porcine aortic bioprosthesis used single layer suture has good hemodynamic characteristics as the nature structure . The modified suture method decrease the implantation time.Nemerical data of the evaluation in vitro show that the difference between single layer suture group and double layer suture group in effective orifice area,transvalvular pressure gradient and regurgitation ratio haveno statistical significance. This experiment is the foundation of the animal and clinical experiment in the future.
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 identify the short ( lt;30 days) and intermediate ( 30 days to 6 months) benefits and risks of tracheobronchial stents in patients with malignant airway stenosis. Methods 55 cases with malignant airway disease who underwent tracheobronchial stents placement from January 2006 to May 2008 were followed up for 6 months. The efficacy rate, complication rate, reintervention rate, and survival were analyzed. Results There were 61 self-expanding metal stents placed in 55 patients with malignant disease, with no intraoperative mortality. The immediate efficacy rate was 100% , the short-term( lt;30 days) efficacy rate was 94. 5% , and the survival rate in 6 months was 32. 7% . The complications included tumor ingrowth, excessive granulation tissue, stent migration, and restenosis. A total of 14 cases of complicationswere observed, in which two occurred during the short-term period ( lt; 30 days ) and the remaining complications occurred after 30 days. Conclusions Tracheobronchial stents can improve symptoms immediately for the patients with unresectable malignant central airway obstruction with fairly safety. The benefit of airway stents is particularly seen in the short-termperiod and the complications occur mainly after 30 days.
ObjectiveTo investigate the effect of drained versus nondrained pancreaticojejunostomy on prevention of the pancreatic leakage after pancreaticoduodenectomy. MethodsSeventysix patients underwent the standard pancreaticoduodenectomy including resection of the distal stomach,common bile duct, the head of pancreas and the duodenum.Pancreaticenteric reconstruction was accomplished via either pancreaticojejunostomy by endtoside anastomsis or pancreaticojejunostomy by ducttomucosa anastomsis.The stented external drainage of pancreatic duct was used in 45 of 76 patients. ResultsPancreatic leakage was identified in 1 patient in the drained group consisting of 45 patients,in 7 patients in the nondrained group consisting of 31 patients, the incidence of pancreatic leakage in the drained group (2.2%) was significantly less than in the nondrained group (22.6%,P＜0.05).ConclusionComparing the incidences of pancreatic leakage from both groups,the authors believe that the stented external drainage of pancreatic duct can significantly reduce the incidence of pancreatic leakage after pancreaticoduodenectomy.
Tracheal stents are often used to maintain the patency of the trachea and bronchia in patients suffering from central airway lesions. Metallic tracheal stents are now widely used in the clinical setting, but these types of stents can cause many intractable material-related complications. Biodegradable tracheal stents are made of biodegradable polymer materials with good mechanical strength for maintaining the patency of the lesion segment during a certain period of time, and then they can be gradually degraded into harmless products in human body. Compared with conventional metallic tracheal stent, biodegradable tracheal stents have a good prospect in clinic. In this article, we review the choice of biodegradable tracheal stent materials, experimental progress in biodegradable tracheal stent as well as the challenges we are facing.
Objective To study the diagnostic procedures and management of aortic stent graft infection. Methods Clinical data of 4 patients with aortic stent graft infection from 1998 to 2008 were analyzed retrospectively. Results Primary disease was thoracic endovascular aortic repair in 2 cases and endovascular aneurysm repair in another 2 cases. Constitutional symptoms and abscess information on imaging studies were presented in all patients. Salmonella choleraesuis was revealed in 2 cases. Surgical debridement, drainage and systematic antimicrobial therapies were given to 2 patients. The remaining 2 patients were managed with antimicrobial therapy only. During follow-up, there was no recurrence of infection. Conclusions Infection of aortic stent graft infection is a rare but potentially devastating complication. Radiologic studies can serve as important adjuncts in the diagnosis of endovascular graft infections. Several treatment options are available, some cases may be managed with conservative treatment.
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.
To address the conflict between the “fitness” and “feasibility” of body-fitted stents, this paper investigates the impact of various smoothing design strategies on the mechanical behaviour and apposition performance of stent. Based on the three-dimensional projection method, the projection region was fitted with the least squares method (fitting orders 1–6 corresponded to models 1–6, respectively) to achieve the effect of smoothing the body-fitted stent. The simulation included the crimping and expansion process of six groups of stents in stenotic vessels with different degrees of plaque calcification. Various metrics were analyzed, including bending stiffness, stent ruggedness, area residual stenosis rate, contact area fraction, and contact volume fraction. The study findings showed that the bending stiffness, stent ruggedness, area residual stenosis rate, contact area fraction and contact volume fraction increased with the fitting order's increase. Model 1 had the smallest contact area fraction and contact volume fraction, 77.63% and 83.49% respectively, in the incompletely calcified plaque environment. In the completely calcified plaque environment, these values were 72.86% and 82.21%, respectively. Additionally, it had the worst “fitness”. Models 5 and 6 had similar values for stent ruggedness, with 32.15% and 32.38%, respectively, which indicated the worst "feasibility" for fabrication and implantation. Models 2, 3, and 4 had similar area residual stenosis rates in both plaque environments. In conclusion, it is more reasonable to obtain the body-fitted stent by using 2nd to 4th order fitting with the least squares method to the projected region. Among them, the body-fitted stent obtained by the 2nd order fitting performs better in the completely calcified environment.