激光血管成形术的新发展

本文综合介绍了激光血管成形术的主要最新发展。

神经外科:1994年回顾

本文回顾神经外科领域内1994年发表的有重要意义的临床和研究论文,刊于《Contemporary Neuro-surgery）上,每年一次,有助于了解过去一年中神经外科领域的进展。原论文较长,节译以飨读者。以后将逐年译出,刊于《微侵袭神经外科杂志》。

Cutting-balloon angioplasty before drug-eluting stent implantation for the treatment of severely calcified coronary lesions

Background Severely calcified coronary lesions respond poorly to balloon angioplasty, resulting in incomplete and asymmetrical stent expansion. Therefore, adequate plaque modification prior to drug-eluting stent （DES） implantation is the key for calcified lesion treat- ment. This study was to evaluate the safety and efficacy of cutting balloon angioplasty for severely calcified coronary lesions. Methods Ninety-two consecutive patients with severely calcified lesions （defined as calcium arc 〉 180% calcium length ratio 〉 0.5） treated with bal- loon dilatation before DES implantation were randomly divided into two groups based on the balloon type： 45 patients in the conventional balloon angioplasty （BA） group and 47 patients in the cutting balloon angioplasty （CB） group. Seven cases in BA group did not satisfactorily achieve dilatation and were transferred into the CB group. Intravascular ultrasound （IVUS） was performed before balloon dilatation and after stent implantation to obtain qualitative and quantitative lesion characteristics and evaluate the stent, including minimum lumen cross-sectional area （CSA）, calcified arc and length, minimum stent CSA, stent apposition, stent symmetry, stent expansion, vessel dissection, and branch vessel jail. In-hospital, 1-month, and 6-month major adverse cardiac events （MACE） were reported. Results There were no statistical differences in clinical characteristics between the two groups, including calcium arc （222.2° ± 22.2° vs. 235.0° ± 22.1 °, p=0.570）, calcium length ratio （0.67 ± 0.06 vs. 0.77± 0.05, P = 0.130）, and minimum lumen CSA before PCI （2.59 ±0.08 mm2 vs. 2.52 ± 0.08 mm2, P = 0.550）. After stent implantation, the final minimum stent CSA （6.26 ± 0.40 mm2 vs. 5.03 ± 0.33 mm2; P = 0.031） and acute lumen gain （3.74 ±0.38 mm2 w. 2.44 ± 0.29 mm2, P = 0.015） were significantly larger ila the CB group than that of the BA group. There were not statis tically differences in stent expansion, stent symmetry, incomplete stent apposition, vessel dissection and branch vessel jail between two groups. The 30-day and 6-month MACE rates were also not different. Conclusions Cutting balloon angioplasty before DES implantation in severely calcified lesions appears to be more efficacies including significantly larger final stent CSA and larger acute lumen gain, without increasing complications during operations and the MACE rate in 6-month.

Outcome of non surgical hepatic decompression procedures in Egyptian patients with Budd-Chiari

AIM: To evaluate outcome of patients with Budd-Chiari syndrome after balloon angioplasty ± stenting or transjugular intrahepatic portosystemic shunt (TIPS). METHODS: Twenty five patients with Budd-Chiari syndrome admitted to Ain Shams University Hospitals, Tropical Medicine Department were included. Twelve patients (48%) with short segment occlusion were candidates for angioplasty; with stenting in ten cases and without stenting in two. Thirteen patients (52%) had Transjugular Intrahepatic Portosystemic Shunt. Patients were followed up for 12-32 mo. RESULTS: Patency rate in patients who underwent angioplasty ± stenting was 83.3% at one year and at end of follow up. The need of revision was 41.6% with one year survival of 100%, dropped to 91.6% at end of follow up. In patients who had Transjugular Intrahepatic Portosystemic Shunt, patency rate was 92.3% at one year, dropped to 84.6% at end of follow up. The need of revision was 38.4% with one year and end of follow up survival of 100%. Patients with patent shunts showed marked improvement compared to those with occluded shunts. CONCLUSION: Morbidity and mortality following angioplasty ± stenting and TIPS are low with satisfactory outcome. Proper patient selection and management of shunt dysfunction are crucial in improvement.

Prolonged high-pressure balloon angioplasty of femoropopliteal lesions：Impact on stent implantation rate and mid-term outcome

Objectives To assess the impact on stent implantation rate and mid-term outcomes of prolonged high pressure angioplasty of femoropopliteal lesions. Methods We retrospectively enrolled 620 consecutive patients from January 2011 to December 2011 （75.6 ±12.3 years, 355 males, 76.5%in Rutherford class 5-6）, referred for critical limb ischemia and submitted to prolonged high-pressure angioplasty of femoropopliteal lesions. The definition of prolonged high-pressure angioplasty includes dilation to at least 18 atm for at least 120 s. Proce-dural data, and clinical and instrumental follow-up were analyzed to assess stent implantation rate and mid-term outcomes. Results The preferred approach was ipsilateral femoral antegrade in 433/620 patients （69.7%） and contralateral cross-over in 164/620 （26.4%） and pop-liteal retrograde＋femoral antegrade in 23/620 （3.7%）. Techniques included subintimal angioplasty in 427/620 patients （68.8%） and endolu-minal angioplasty in 193/620 patients （31.2%）. The prolonged high pressure balloon angioplasty procedure was successful in 86.2%（minor intra-procedural complications rate 15.7%）, stent implantation was performed in 74 patients （11.9%）, with a significant improvement of ankle-brachial index （0.29 ±0.6 vs. 0.88 ±0.3, P〈0.01） and Rutherford class （5.3 ±0.8 vs. 0.7 ±1.9, P〈0.01）, a primary patency rate of 86.7%, restenosis of 18.6%on Doppler ultrasound and a target lesion revascularization of 14.8%at a mean follow-up of 18.1 ±6.4 months （range 1-24 months）. Secondary patency rate was 87.7%. Conclusions Prolonged high pressure angioplasty of femoropopliteal lesions appears to be safe and effective allowing for an acceptable patency and restenosis rates on mid-term.

INTERVENTIONAL OR SEMI-INTERVENTIONAL TREATMENT FOR BUDD-CHIARI SYNDROME

Objective. Report the results of interventional or semi-interventional techniques for 173 patients with Budd-Chiari syndrome.Method. This group included 120 males and 53 females. The pathologic lesions composed of localized complete occlusion of inferior vena cava (IVC) (78), IVC stenosis (49), IVC membrane with a hole (37), membrane of hepatic vein (HV) (3), IVC thrombosis (4), IVC membrane with thrombosis (2) and IVC lesion with occlusion of HV (32). Treatment methods included that I: Percutaneous transinferior vena cava angioplasty (PTA) (76); II: IVC PTA with stent (59); III: Percutaneous transhepatic vein recanalization (3); IV: IVC thrombolysis through a catheter (4); V; Combined transcardiac and trans-femoral venous membranotomy and balloon dilation (22); VI: V and stent (17); VII; Stenting during radical surgery (3); VIII: Additional operation after intervention (23).Results. The immediate technique success rate for intervention was 90.1%, for the semi-intervention was 100%. The IVC pressure was reduced from 3 to 29 cmH20. Complications occurred in 8 cases. The death rate was 2.9%. A follow-up study showed the recurrence rates were 14.5% in IVC PTA group, 1.7% in IVC PTA with stent, 18.2% in combined technique without stent and no recurrence was found in other groups.Conclusion. The PTA is the first choice for localized lesions. When elastic recoil occurs, immediate stenting is suggested. The semi-interventional approach is advised for PTA failure and more complicated cases. For those with both IVC lesion and occlusion of HV, the additional operation is needed after IVC intervention.

Ischemic colitis and large bowel infarction:A case report

Ischemic bowel disease results from an acute or chronic drop in the blood supply to the bowel and may have various clinical presentations, such as intestinal angina, ischemic colitis or intestinal infarction. Elderly patients with systemic atherosclerosis who are symptomatic for the disease in two or more vascular beds have multiple comorbidities and are particularly at risk. The clinical evolution and outcome of this disease are difficult to predict because of its pleomorphic aspects and the general lack of statistical data. In this paper, we present the case of a patient who was monitored in our unit for six years. For this patient, we encountered iterative changes in the clinical pattern, beginning with chronic "intestinal angina" and finishing with signs of acute mesenteric ischemia after an episode of ischemic colitis. This evolution is particularly rare in clinical practice, and the case is instructive because it raises discussions about the natural history of the condition and the thera-peutic decisions that should be made at every stage of the disease. An important lesson is that ischemic bowel disease should always be considered in patients who have multiple risk factors for atherosclerosis and have experienced recurrent "indistinct" abdominal symptoms.In these cases, aggressive investigation and therapeutic decisions must be taken whenever possible. Despite an absence of standardized protocols, angiographic evaluation and revascularization procedures have beneficial outcomes. Current advances in endovascular therapy, such as percutaneous transluminal angioplasty with stenting, should be increasingly used in patients with chronic mesenteric ischemia. Such therapy can avoid the risks that are associated with open repair. However, technical difficulties, especially in severe stenotic lesions, frequently occur.

COMBINED INTRAOPERATIVE ILIAC ARTERY STENTS AND FEMORO- POPLITEAL BYPASS FOR MULTILEVEL ATHEROSCLEROTIC OCCLUSIVE DISEASE

Objective. To review our preliminary experience and evaluate our early results of a combined intraoperative iliac angioplasty and stenting with infrainguinal revascularization in multilevel atherosclerotic occlusive disease. Methods. From July 1999 to April 2000, intraoperative iliac angioplasty and stenting combined with simultaneous femoro- popliteal bypass were performed on 12 lower extremities of 10 patients suffering from multilevel atherosclerotic occlusive disease. There were 8 men and 2 women, average 72 years. The indications for procedures included disabling claudication in 3 and rest pain in 7 patients. Results. Eleven iliac angioplasty and stent procedures combined with simultaneous 9 femoro- popliteal bypass and 3 femoro- femoral- popliteal bypass were performed in 12 limbs of 10 patients. Angioplasty and stent placement was technically successful in all patients. One contralateral femoral- popliteal bypass was failure after femorofemoral- popliteal bypass. There were no additional instances of procedural or postoperative morbidity or mortali- ty. Mean follow- up was 5 months (range 1～ 10 months). During the follow- up period, one femoro- infrapopliteal graft became occluded after 7 months and above- knee amputation was required. The cumulative primary patency rate of stented iliac arteries, femoro- femoral bypass grafts and femoro- popliteal bypass grafts were 100％ (11/11), 100％ (3/3) and 90.9％ (10/11) in the follow- up period, respectively. The amputation rate was 8.3％ (1/12). Conclusions. Intraoperative iliac artery PTA and stent placement can be safely and effectively performed simultaneously with infrainguinal revascularization for multilevel atherosclerotic occlusive disease by skilled vascular surgeon, using a portable C arm fluoroscopy in the operating room. Furthermore, iliac artery PTA and stenting was valuable adjunct to distal bypass either to improve inflow and outflow, or to reduce the extent of traditional surgical intervention, and also, any angioplasty and stenting- related complications can be immediately corrected as well.

Application of GlycoProtein IIb/IIIa antagonist( Integrilin) in peri-percutaneous transluminal catheter angioplasty and stent implantation in Chinese

Objective: to report the application of GPIIb/IIIa antagonist (Integrilin) in peri percutaneous transluminal catheter angioplasty and stent implantation in Chinese. Method: Twenty one patients who underwent percutaneous transluminal catheter angioplasty(PTCA) and stent implantation were included. After arterial puncture, integrilin was injected at dose of 180ug/kg, and then maintained at 2μg/kg·min for 18 hours. Asprine, plavix(clopidogrel) and heparin were used at the same time. ACT, PT, KPTT and blood routine were routinely monitored. Results: All sheaths were drawn out 2 to 4 hours after the procedure.. There was no severe complication such as hematoma, acute and subacute thrombosis in coronary artery, or thrombocytopenia. ACT returned to less than 150 seconds in 2 hours in 15 patients; in 4 hours in 6 patients. There was no significant difference between the pre and post procedure value of PT and platelet count. KPTT was significantly higher than pre procedure value at 2 hours after the procedure .No recurrence of angina pectoris was observed in the first nine patients within one year follow up, and no restenosis occurred in stents in the five patients who had coronary angiography one year later. Conclusion: Application of GPIIb/IIIa receptor antagonist (Integrilin) in peri percutaneous transluminal catheter angioplasty and stent implantation in combination with aspirin and plavix could significantly reduce the dosage and duration of heparin with benefit of shortening the indwelling time of sheaths, but did not increase risk of bleeding or lead to thrombosis in stent.

COMPARATIVE EXPERIMENTAL STUDY OF HO-YAG LASER AND TRUE- CUT BIOPSY NEEDLE IN MYOCARDIAL REVASCULARIZATION

Objective.To study the mechanism and effects of blood perfusion on acute ischemic region of myocardium through channel created by Ho- Yag laser and True- cut biopsy needles with myocardial contrast echocardiography. Methods. We partially ligated the left anterior descending coronary artery of canine hearts between the lst and 2nd diagonal branches to produce two groups of acute myocardial ischemia models and then performed tran- smyocardial revascularization (TMR) on this region with Ho- Yag laser and True- cut biopsy needles. Myocardial contrast echocardiography was performed with a new generation of ultrasound contrast agent and second harmonic imaging of this region before, during ischemia and after revascularization. Pictures were taken with“ R” wave trigger skill. Results. Acoustic density (dB) in the ischemic region (anterior wall) with myocardial contrast echocardiography decreased obviously after the left anterior descending artery was ligated (Laser group: 5.40± 1.81, Needle group: 7.11± 2.51) compared with that before (Laser group: 11.69± 1.61, Needle group: 12.96± 2.88, P< 0.01). dB increased remarkably after TMR by either laser or True cut biopsy needle (Laser group: 11.02± 2.01, Needle group: 10.01± 4.45. P< 0.01) compared to that during ischemia and approximated to that before ischemia (P >0.05). We found that the acoustic density of the contrast developed one picture (one cardiac cycle) ahead in the transmyocardial revascularization region than that in the lateral and other region of the left ventricle wall in the scan of both groups. Conclusions. Acute ischemic myocardium can be perfused immediately by oxygenated blood from the left ventricle through channels created with both Ho- Yag laser and True- cut biopsy needles. Evidence of blood perfusion through these channels mainly during systolic phase was detected, and myocardial contrast ultrasound using intravenous perfluorocarbon- exposed sonicated dextrose albumin was regarded as a reliable method in the study of transmyocardial revascularization.

Effect of diltiazem and lidocaine on arterial pressure or heart rate and the quality of extubation in patients undergoing uvulopalatopharyngoplasty

Objective：To evaluate the effect of diltiazem and lidocaine on arterial pressure or heart rate and the quality of extubation in patients undergoing uvulopalatopharyngoplasty. Methods： Sixty patients were randomly divided into 4 groups： In the control group patients were given saline; in the lidocaine group patients were given 1.0 mg/kg lidocaine ; in the diltiazem group patients were given 0. 2 mg/kg diltiazem; and in the lidocaine plus diltiazem group patients were given 1.0 mg/kg lidocaine and 0. 2 mg/kg diltiazem. These drugs were given 2 rain before tracheal extuhation. Values for SBP, DBP, and HR were recorded, on arriving at the operating room, immediately at the end of the surgery, at the time of injection of the study drugs, at tracheal extubation, at 1 min and 5 min after extubation. The quality of extubation according to the Sebel＇s grading scale were compared among the 4 groups. Results：During extubation in the control group HR, SBP and DBP increased significantly when compared to baseline levels. Both lidocaine （1.0 mg/kg） and diltiazem （0. 2 mg/kg） successfully alleviated these increases. The suppressive effect of diltiazem was greater than that of lidocaine. The combinative use of the two drugs minimized the increases. The administration of lidocaine significantly suppressed bucking or coughing compared with the other groups. Conclusions： The pressor responses and tachycardia occurring in patients with uvulopalatopharyngoplasty during emergence from anesthesia and tracheal extubation, can be easily blocked by a bolus dose of 1.0 mg/kg lidocaine, 0. 2 mg/kg diltiazem or the comhinative use of the two drugs. And the concurrent use of lidocaine and diltiazem alleviated the hemodynamic changes more obviously.

Choice PTTM guidewire for recanalization of total occlusive coronary arteries

Objective: To evaluate the therapeutic effects of 0. 014' Choice PTTM wire in chronic total occlusion angioplasty. Methods: Balloon angioplasty was attempted in 25 arteries with chronic total occlusion, with the mean time of occlusion of 17±13 months (ranging from 2 to 84 months) and mean length of 14±6 mm (ranging from 5 to 25 mm). The morphology of the lesions included bridging collaterals (4 cases), calcification (3 cases) and major side branch at the lesion (4 cases) . Choice PT?wire was used electively in all the cases. Results: Lesion was crossed successfully in 92% (23/25) cases, without incidences of dissection of the coronary artery with subintimal entry. Balloon angioplasy and stenting (n = 21) were performed with good immediate angiograghic results. Acute myocardial infarction or death occurred in none of the patients. Conclusion Successful recanalization of chronic coronary total occlusions using Choice PTTM wire can be achieved with good safety.

A special recurrent pattern in small hepatocellular carcinoma after treatment:Bile duct tumor thrombus formation

AIM:To investigate the clinicopathologic features of bile duct tumor thrombus(BDTT) occurrence after treatment of primary small hepatocellular carcinoma(sHCC) .METHODS:A total of 423 patients with primary sHCC admitted to our hospital underwent surgical resection or local ablation.During follow-up,only six patients were hospitalized due to obstructive jaundice,which occurred 5-76 mo after initial treatment.The clinicopathologic features of these six patients were reviewed.RESULTS:Six patients underwent hepatic resection(n=5) or radio-frequency ablation(n=1) due to primary sHCC.Five cases had an R1 resection margin,and one case had an ablative margin less than 5.0 mm.No vascular infiltration,microsatellites or bile duct/canaliculus affection was noted in the initial resected specimens.During the follow-up,imaging studies revealed a macroscopic BDTT extending to the common bile duct in all six patients.Four patients had a concomitant intrahepatic recurrent tumor.Surgical re-resection of intrahepatic recurrent tumors and removal of BDTTs(n=4) ,BDTT removal through choledochotomy(n= 1) ,and conservative treatment(n=1) was performed.Microscopic portal vein invasion was noted in three of the four resected specimens.All six patients died,with a mean survival of 11 mo after BDTT removal or conservative treatment.CONCLUSION:BDTT occurrence is a rare,special recurrent pattern of primary sHCC.Patients with BDTTs extending to the common bile duct usually have an unfavorable prognosis even following aggressive surgery.Insufficient resection or ablative margins against primary sHCC may be a risk factor for BDTT development.

Retrospective analysis of percutaneous transluminal coronary angioplasty and coronary stenting

Objective To examine long term efficacy of percutaneous transluminal coronary angioplasty (PTCA),coronary stenting and to assess the factors affecting its efficacy Methods A total of 790 patients who underwent successful PTCA and PTCA+stent in this hospital were followed by direct interview or letter The rate of follow up was 84 2% and the period of follow up was 0 9-12 7 (3 5±2 4) years Results During follow up, 4 (0 5%) patients died, 22 (2 8%) had nonfatal acute myocardial infarction, 10 (1 3%) had coronary artery bypass surgery, and 98 (12 4%) had repeat PTCA The rate of recurrent angina pectoris was 31 1% The cardiac event free survival rate calculated by the Kaplan Meier method was 88 2% at 1 year and 80 6% at 12 7 years Cox regression analysis showed that there was a positive correlation between AMI history, stent implantation and the risk of cardiac events, and there was a negative correlation between the number of diseased arteries and the risk of cardiac events Compared to the PTCA group, patients with PTCA+stent had significantly lower rates of total cardiac events Conclusion The long term efficacy of PTCA, especially PTCA + stent in Chinese patients was very satisfactory, suggesting that PTCA+stent therapy should be the major treatment for revascularization in patients with coronary heart disease

Role of Dongchongxiacao (Cordyceps) in prevention of contrast-induced nephropathy in patients with stable angina pectoris

OBJECTIVE： To study the preventative effects of Dongchongxiacao （Cordyceps） on contrast-induced nephropathy （CIN） in patients with stable angina pectoris （SAP）. METHODS： One-hundred and three SAP inpatients were divided randomly into two groups： basic treat- ment （n=51） and Dongchongxiacao （Cordyceps） treatment （n=52）; corbrin capsules （3 g; t.d.s.） were used 3 days before angioplasty and 3 days after an- gioplasty）. Serum creatinine （Scr） was assessed at the time of hospital admission and 1, 2, and 3 days after angioplasty. Values of kidney injury mole- cule-1 （KIM-1）, neutrophil gelatinase-associated li- pocalin （NGAL） and interleukin （IL） 18 in the kidney were detected before angioplasty and 1 day after angioplasty in the patients of both groups. The prevalence of CIN between the two groups was then compared. RESULTS： CIN occurred in 9 of 103 patients （8.74%）. The prevalence of CIN in the Dongchongxiacao （Cordyceps） treatment group was lower than that of the basic treatment group （5.77% vs 11.76%） but the difference was not significant （P〉0.05）. The post-procedure mean peak of Scr, post-procedure increase in Scr levels from baseline, and urine levelsof KIM-1, NGAL and IL18 after the procedure in the Dongchongxiacao （Corclyceps） treatment group were significantly lower than those in the basic treatment group （P〈0.05）. CONCLUSION： Prophylactic treatment with Dongchongxiacao （Cordyceps） in SAP patients who undergo coronary angiography or coronary inter- vention could prevent contrast-induced renal im- pairment.

An updated view on the differentiation of stem cells into endothelial cells

Endothelial cells form the internal barrier between circulating blood and the vessel wall.They regulate arterial activity and mediate pathological reactions to vascular injuries such as atherosclerosis and balloon angioplasty.The development and differentiation of endothelial cells is a complex and coordinated process involving multiple levels of signaling and transcriptional and post-transcriptional regulation.Elucidating the mechanism of endothelial differentiation will not only enhance our understanding of vascular disease pathogenesis,but also facilitate our ability to produce vessels cells from pluripotent stem cells for regeneration purposes.In this review,we discuss the current understanding of how stem cells differentiate into endothelial cells at the level of signaling,transcription and microRNA regulation.

ADAMTS-7 promotes vascular smooth muscle cells proliferation in vitro and in vivo

Vascular smooth muscle cell(VSMC) proliferation and migration are pivotal for the pathogenesis of atherosclerosis and post-angioplasty restenosis. We have recently reported that a disintegrin and metalloproteinase with thrombospondin motifs-7(ADAMTS-7), a novel metalloproteinase, contributes directly to neointima formation by mediating VSMC migration. However, whether ADAMTS-7 affects VSMC proliferation remains unclear. In this study, we found that luminal adenoviral delivery of ADAMTS-7 aggravated intimal hyperplasia 7 d after injury, paralleled by an increased percentage of PCNA-positive cells in both intima and media. In contrast, perivascular administration of ADAMTS-7 si RNA, but not scrambled si RNA to injured arteries attenuated intimal thickening at day 7, paralleled with reduced intimal VSMC replication, without alteration of VSMC proliferation in the media. In accordance, [3H]-thymidine incorporation assay in primary cultured rat VSMCs revealed an enhanced replication rate(by 61%) upon ADAMTS-7 overexpression and retarded proliferation(by 23%) upon ADAMTS-7 si RNA administration. Our data demonstrates that ADAMTS-7 promotes VSMC proliferation both in vitro and in vivo. ADAMTS-7 may therefore serve as a novel therapeutic target for atherosclerosis and post-angioplasty restenosis.

Percutaneous balloon angioplasty of coarctation of the aorta in children: 12-year follow-up results

Objective To evaluate the efficiency of percutaneous balloon angioplasty of coarctation ot the aorta in children and discuss its risk factors that can lead to poor long-term results. Mehods From September 1987 to August 1999, 24 patients underwent 27 balloon angioplasty procedures for native or recurrent coarctation of the aorta at our institution. There were 19 patients with discrete (membranous) coarctation, 4 patients with long-segment and aortic arch hypoplasia, and 1 patient with postoperative recurrence. The balloon diameter was chosen not to exceed the diameter of the aorta proximal to the stenotic site ( 11.06 + 2.80 mm vs 11.78 + 3.18 mm), with the chosen diameter two to four times that of the stenotic segment (2.57 + 0.68 times). The patients have been followed up for half to twelve years (mean 6.2 + 2.8 years). Satisfactory result was defined as a reduction in the pressure gradient across the site of coarctation to ≤20 mm Hg.Results The systolic pressure gradient across the coarctation site decreased from 48.17 + 14.68 mm Hg to 14.96 + 13.12 mm Hg ( P ＜ 0.01 ) and the diameter of the coarctation site increased from 4.66 + 2.43 mm to 8.80 + 3.32 mm ( P ＜ 0.01 ). Immediate satisfactory results were obtained in 19 patients (79％). Of the 5 patients with unsatisfactory results, 4 had aortic arch hypoplasia and 1 had membranous coarctation. Of the 19 patients with satisfactory results, 18 patients had membranous coarctation and 1 patient had recurrent postoperative coarctation. No aneurysm and other complications had occurred in any patients at the follow-ups.Conclusion Percutaneous balloon angioplasty is an effective treatment altemative to surgery in most patients with recurrent postoperative or native membranous coarctation of the aorta. It should not be recommended for the coarctation of aortic arch hypoplasia.

Hydrophobe-substituted bPEI derivatives: boosting transfection on primary vascular cells

Gene therapy targeted to vascular cells repre- sents a promising approach for prevention and treatment of pathological conditions such as intimal hyperplasia, in-stent and post-angioplasty restenosis. In this context, polymeric non-viral gene delivery systems are a safe alternative to viral vectors but a further improvement in efficiency and cytocom- patibility is needed to improve their clinical success. Herein, a library of 24 branched polyethylenimine （bPEI） derivatives modified with hydrophobic moieties was synthesised, char- acterised and tested in vitro on primary vascular cells, aim- ing to identify delivery agents with superior transfection effi- ciency and low cytotoxicity. Low molecular weight PEIs （0.6, 1.2 and 2 kDa） were grafted with long （C18） and short （C3） aliphatic chains, featuring different unsaturation degrees and degrees of substitution. 0.6 kDa bPEI-based derivatives were generally ineffective in transfection on vascular smooth mus- cle cells （VSMCs）, while among the other derivatives some promising vectors were identified. Forcing polyplexes on the cell surface by means of centrifugation invariably boosted transfection levels but increased cytotoxicity as well. Of note, a propionyl-snbstituted derivative （PEI2-PrA1, C3：0） was the most effective on both VSMCs and endothelial cells （ECs）, with higher and more sustained gene expression in combi- nation with markedly lower cytotoxicity with respect to the gold standard 25 kDa bPEI. In addition, a linoleoyl-substi- tuted derivative （PEI1.2-LA6, C18：2） owing to its high effi- ciency in VSMCs and relative inefficacy in ECs, combined with tolerable cytotoxicity was proposed as a vector for spe- cific VSMCs targeting.

Overview of the Basic Research on Vascular Surgery in China

This paper sums up the fundamental research projects on Vascular Surgery supported by National Natural Science Foundation of China from 1996 to 2000, and presents the experimental results and advances in the aspects of ischemia disease, the formation mechanism and prevention of restenosis, the development of abdominal aorta aneurysm and portal hypertention.