Carotid stent delivery in an XMR suite: immediate assessment of the physiologic impact of extracranial revascularization

BACKGROUND AND PURPOSE: Patients undergoing stent placement as treatment for severe stenosis of the internal carotid artery (ICA) were assessed with MR imaging in a combined MR-radiographic (XMR) angiography suite. MR imaging was performed before and immediately following conventional radiography-guided stent placement. Changes in MR imaging measurable properties, including flow and perfusion, resulting from stent placement were evaluated. PATIENTS AND TECHNIQUES: MR imaging analysis was performed for 12 patients with >70% stenosis of the ICA before and after conventional radiography-guided deployment of a carotid stent. MR imaging acquisitions included angiography, quantitative flow analysis, perfusion, diffusion, and turbo-fluid-attenuated inversion recovery (FLAIR). These acquisitions were all performed immediately before and following stent placement by using conventional techniques. RESULTS: MR angiography proved sufficient for identifying the target lesion and permitting targeted flow analysis. MR flow analysis demonstrated a marked increase in flow in the treated carotid artery (+2.2 +/- 1.2 mL/s) and little change in other extracranial arteries. MR perfusion imaging showed no significant differences in relative cerebral blood volume between hemispheres before or after treatment, but there was a modest decrease in mean transit time and time to peak evident in the treated hemisphere after stent placement. Diffusion imaging did not demonstrate any ischemic foci resulting from carotid stent treatment. Hyperintensity of the CSF was noted on turbo-FLAIR acquisitions in the ipsilateral hemisphere following stent placement in 75% of patients. CONCLUSION: MR imaging reliably reflects the state of the carotid artery and provides a means of monitoring and quantifying the effects of revascularization.     

大动脉炎颈动脉狭窄球囊扩张和内支架的治疗

目的：探讨应用球囊扩张和血管内支架治疗大支脉炎、颈动脉狭窄、材料和方法：３例大动脉炎性颈动脉狭窄的患者，狭窄段均超过８ｃｍ，１例单纯球囊扩张；２例球囊扩张后植入Ｗａｌｌｓｔｅｎｔ支架。结果：术后狭窄率均为０，达到了良好的治疗效果，单纯球囊扩张的动脉一年后动脉完全闭塞、西入血管内支架的２例，分别是在４．５个月和４个月检查，一例血管内支架的近端出现了再狭窄，另一例未出现再狭窄。结论：对于大动脉炎性长段     

Critical stenosis of axillary artery treated with percutaneous angioplasty and stenting: a case report and review of the literature

Focal axillary artery stenosis or occlusion is a rare occurrence that is most commonly encountered after severe trauma involving the shoulder joint or proximal humerus. Other etiologies that can lead to axillary artery injury or pathology include different vasculitides, radiation arteritis, crutch-injury, and peripheral arterial disease. In this case report, a 70-year-old woman was referred for asymmetrically decreased right brachial artery systolic pressure and right-hand paresthesia with overhead abduction. Further evaluation with imaging revealed critical stenosis of the right axillary artery. The focal stenotic lesion was treated with drug-coated balloon angioplasty and stent placement leading to in-line flow and resolution of symptoms. Duplex exam 6 months post-treatment demonstrated a widely patent right axillary artery stent without stenosis. Biannual clinic visits up to 2 years post stent placement confirmed resolution of symptoms.     

Stent implantation in a patient with non-hemorrhagic vertebral artery dissection associated with severe,continuously progressive stenosis in the posterior inferior cerebellar artery bifurcation region: A case report

Generally, the prognosis of non-hemorrhagic vertebral artery dissection is good. Treatment should be considered when stenosis progresses or when an aneurysm is formed. However, no clear treatment policy has been established. The purpose of this case report was to describe the treatment policy for non-hemorrhagic onset vertebral artery dissection with severe stenosis around the posterior inferior cerebellar artery (PICA) bifurcation and aneurysm, where stent placement in the vertebral artery was difficult. This report describes healing without complications with stent implantation in the PICA performed to treat non-hemorrhagic vertebral artery dissection with associated severe, continuously progressive stenosis in the PICA bifurcation region. A 36-year-old woman was examined at the authors’ hospital for persistent pain in the left posterior neck. Left vertebral arteriography revealed stenosis due to dissection around the PICA bifurcation and aneurysm formation at the distal position. Due to the progression of stenosis, there were concerns about PICA occlusion, and stent implantation in the vertebral artery was performed via the PICA. Neck pain ceased immediately after surgery, and 3 months later, cerebral angiography showed favorable patency of the PICA and decreased aneurysm size. This case suggests that stent implantation in the PICA might be a useful treatment option for non-hemorrhagic vertebral artery dissection with associated severe stenosis in the PICA bifurcation region.     

Preliminary results of endovascular stent-assisted angioplasty for symptomatic middle cerebral artery stenosis

BACKGROUND AND PURPOSE: Stent placement for intracranial atherosclerosis has become an alternative treatment technique; however, stent placement for middle cerebral artery (MCA) stenosis remains a technical and clinical challenge. Our purpose was to assess the feasibility, safety, and effectiveness of stent placement for MCA stenosis. METHODS: Between May 1998 and August 2003, we performed stent placement for MCA stenosis (more than 50%) in 17 patients and retrospectively analyzed the technical success rate, complications, and outcomes over 10 months. RESULTS: Stent placement was technically successful in 16 (94.1%) patients and failed in one patient (5.9%), because the stent did not reach the lesion due to carotid artery tortuousity. In 16 patients, postprocedural angiography showed restoration of the normal luminal diameter. Acute in-stent thromboses occurred in nine patients (56.3%) and was lysed with abciximab. The parent artery ruptured in two patients (12.5%): One died from massive subarachnoid hemorrhage, and the other patient received a second stent over the tear site. Stent jumping (distal migration at the time of balloon inflation) occurred in one patient (6.3%) and was solved by implanting a second stent. Periprocedural complications included subacute in-stent thrombosis (n = 1, 6.3%) and minor stroke (n=1, 6.3%); these were relieved with heparin therapy or local thrombolysis. Fifteen patients experienced symptomatic relief or were stable at follow-up. Angiographic follow-up (n=6) revealed no in-stent restenosis. CONCLUSION: Stent placement for symptomatic MCA stenosis was technically feasible and effective in alleviating symptoms and improving cerebral blood flow.     

MR imaging assessment of changes in renal function with renal artery stent placement in swine

PURPOSE: To prospectively test the hypothesis that magnetic resonance (MR) imaging can detect changes in renal function at the time of renal artery stent placement in a swine model of renal artery stenosis (RAS). MATERIALS AND METHODS: In this animal care and use committee-approved study, hemodynamically significant (>50%) RAS was surgically induced in six pigs. MR imaging was employed for assessment of the anatomic and physiologic changes induced by fluoroscopically guided stent placement. With MR imaging, we assessed changes in renal blood flow (RBF), extraction fraction (EF), and single-kidney glomerular filtration rate (skGFR) during the procedure. Arterial diameter stenosis before and after stent placement was assessed with x-ray digital subtraction angiography (DSA). Mean changes in functional and anatomic parameters were compared with the Wilcoxon matched-pairs test, with an alpha level of 0.05. RESULTS: There was no significant change in mean RBF after stent deployment (P=.44). Mean EF increased from 0.19+/-0.08 before stent placement to 0.31+/-0.17 after stent placement (P=.16). Mean skGFR measurements were 25 mL/min+/-16 before stent placement and 41 mL/min+/-28 after stent placement (P<.05). According to x-ray DSA measurements, mean stenosis measurements were 60%+/-12% before stent placement and 24%+/-16% after stent placement (P<.02). CONCLUSIONS: In swine, MR imaging can detect immediate changes in renal function after radiographically guided stent placement for unilateral RAS. This functional MR technique may have applications in the setting of hybrid MR/x-ray DSA procedure suites.     

Shrinkage of the distal renal artery 1 year after stent placement as evidenced with serial intravascular ultrasound

The objective of this study was to determine the quantitative intravascular ultrasound (IVUS) and angiographic changes that occur during 1 year follow-up after renal artery stent placement, given that restenosis continues to be a limitation of renal artery stent placement. 38 consecutive patients with symptomatic renal artery stenosis treated with Palmaz stent placement were studied prospectively. IVUS and angiography were performed at the time of stent placement and at 1 year follow-up. At follow-up, angiographic restenosis was seen in 14% of patients. The lumen area in the stent, seen with IVUS, was significantly decreased from 24+/-5.6 mm(2) to 17+/-5.6 mm(2) (p<0.001) solely due to plaque accumulation. The distal main renal artery showed a significant decrease in lumen area owing to a significant vessel area decrease from 39+/-14.0 mm(2) to 29+/-9.3 mm(2) (p<0.001) without plaque accumulation. Angiographic analysis confirmed this reduction in luminal diameter and showed that the distal renal artery diameter at follow-up was significantly smaller than before stent placement (86+/-23.0% vs 104+/-23.9% of the contralateral renal artery diameter; p=0.003). Besides plaque accumulation in the stent, unexplained shrinkage of the distal main renal artery was evidenced with IVUS and angiography 1 year following stent placement.     

Low-profile stent system for treatment of atherosclerotic renal artery stenosis: the GREAT trial

PURPOSE: The Palmaz Genesis Peripheral Stainless Steel Balloon Expandable Stent in Renal Artery Treatment (GREAT) Trial was designed to assess the safety and performance of a low-profile stent for the treatment of obstructive renal artery disease by looking at 6-month renal artery patency uniformly analyzed by a Core Lab. MATERIALS AND METHODS: Fifty-two consecutive patients (mean age, 63.7 years) were successfully treated with the Palmaz Genesis Peripheral Stent (Cordis, Miami, FL) on the Slalom 0.018-inch Delivery System (Cordis Europe N.V., Oosteinde 8, NLO-9301 LJ Roden, The Netherlands) at 11 investigational centers. Patients with severe renal failure and > 8-mm renal artery were excluded. Primary endpoint was angiographic determination of in-stent percent diameter stenosis at 6 months. Fifty-one patients were treated with one stent, one patient was treated with two stents to cover the complete lesion. RESULTS: Mean percentage diameter stenosis before renal angioplasty was 68.2% +/- 12.0%. No stent implantation failure, displacement, need for additional stent implantation, or procedural complication was observed. Six-month angiography was performed in 41 of 52 patients (79%) resulting in a mean in-stent percent diameter stenosis or Quantitative Vessel analysis (QVA) at 6 months of 23.9%. The in-stent binary (percent diameter stenosis > 50%) restenosis rate at 6 months was 14.3%. No fatal events occurred up to 6 months after implantation. Major adverse events occurred in five patients: four patients (7.7%) required a revascularization and one patient (1.9%) experienced a cerebrovascular event, which regressed spontaneously. CONCLUSIONS: The Palmaz Genesis stent (Cordis) provides good results for renal artery stent placement, with an in-stent binary restenosis rate (percent diameter stenosis > 50%) at 6 months of 14.3% as determined with angiography.     

Outcomes of carotid angioplasty and stenting for radiation-associated stenosis

BACKGROUND AND PURPOSE: In light of their high surgical risk, carotid angioplasty and stent placement may be preferred in patients with radiation-associated carotid stenosis. The purpose of this study was to determine the procedural complication rate, patency, and clinical outcomes after carotid angioplasty and stent placement in this small group of high-risk patients. METHODS: Sixteen patients (mean age, 65 years; 5 women and 11 men) who received radiation therapy for head and/or neck malignancy subsequently developed carotid stenosis (mean, 84%; range, 70%-99%) in a total of 19 carotid arteries, which were treated with angioplasty and stent placement. The patients were followed for a mean time of 28 months (range, 5-78 months) with periodic Doppler studies, angiography, CT angiography, or clinically. RESULTS: In the total 19 stented carotid arteries, 23 procedures were performed (22 stent placement procedures and one repeat angioplasty). The procedural stroke rate was 1/23 (4%). The procedural transient ischemic attack rate was 0/23 (0%). There was one other observed complication: a puncture site hematoma. The 30-day postprocedure complication rate was 0/23 (0%); no neurologic symptoms were reported. Fifteen of the 19 vessels (79%) developed no new stenosis throughout the follow-up period. Two of 19 (11%) vessels had repeat angioplasty and stent placement; 1/19 (5%) had a repeat angioplasty. One restented vessel has remained patent for 50 months. Another restented vessel required a third stent placement 17 months after the second. Two of 19 (11%) vessels occluded per Doppler examination 14 and 22 months postprocedure. CONCLUSION: Angioplasty and stent placement have low rates of complications and restenosis in the treatment of radiation-associated carotid occlusive disease.     

Initial clinical experience with the 4-F self-expanding XPERT stent system for infrapopliteal treatment of patients with severe claudication and critical limb ischemia

PURPOSE: To evaluate the primary success and short-term patency associated with a new 4-F sheath-compatible self-expanding nitinol stent after failed conventional angioplasty of distal popliteal and infrapopliteal lesions in severe lifestyle-limiting claudication (LLC) and chronic critical limb ischemia (CLI). MATERIALS AND METHODS: Between May 2003 and July 2005, 35 patients with Rutherford category 3-5 disease (16 patients with CLI, 19 patients with LLC) underwent percutaneous transluminal angioplasty (PTA) and stent implantation. Indications for stent placement were residual stenosis, flow-limiting dissections, or elastic recoil after PTA. Before and after the intervention and during the 6-month follow-up, clinical investigation, color-flow and duplex Doppler ultrasonography, and digital subtraction angiography were performed. Technical success, primary patency at 6 months, clinical improvement as defined by Rutherford with clinical and hemodynamic measures, and complications were evaluated. RESULTS: A total of 22 patients underwent distal popliteal artery stent placement and 13 underwent tibioperoneal artery stent placement. Stent implantation was successfully performed in all patients. After stent placement, the primary cumulative patency rate for the study group at 6 months was 82%. The mean resting ankle-brachial index at baseline was 0.50 +/- 0.16 and significantly increased to 0.90 +/- 0.17 at 12-24 hours after intervention and 0.82 +/- 0.24 at latest follow-up (P < .001 for both). The sustained clinical improvement rate was 80% at the 6-month follow-up. The 6-month limb salvage rate regarding major amputation was 100%. The rate of major complications was 17%. CONCLUSIONS: Infrapopliteal application of the new nitinol stent is a safe, feasible, and effective method with good short-term patency rate in the treatment of severe LLC and chronic CLI.     

Iliofemoral arterial occlusive disease: contrast-enhanced MR angiography for preinterventional evaluation and follow-up after stent placement.

PURPOSE: To evaluate the efficacy of contrast material-enhanced magnetic resonance (MR) angiography for the diagnosis of peripheral arterial occlusion and follow-up after stent placement. MATERIALS AND METHODS: Sixty-seven patients (21 women, 46 men; mean age, 64.6 years) were examined. Digital subtraction angiography and contrast-enhanced MR angiography were performed in 28 patients for preinterventional evaluation of iliofemoral arterial occlusion and in 39 patients for follow-up after stent placement in the iliac or femoral arteries, which had been performed several months before. RESULTS: All 24 occlusions were correctly diagnosed with contrast-enhanced MR angiography. Of the 59 stenoses, 36 were greater than 50% and 23 were 50% or less. Sensitivity and specificity for the detection of stenoses greater than 50% were 100% and 83%, respectively. Patency of the different stents was determined correctly with contrast-enhanced MR angiography. Some stents caused signal intensity dropout, which made MR evaluation of stents difficult. Generally, these signal intensity artifacts were most severe in stainless steel stents and mild in some nitinol stents. CONCLUSION: Contrast-enhanced MR angiography is comparable to digital subtraction angiography for the detection of stenosis greater than 50% and occlusion in the iliofemoral arteries. Stent patency can be determined, but contrast-enhanced MR angiography is not suitable for stent evaluation owing to signal intensity dropout; however, it provides information about the vascular anatomic areas proximal and distal to the stent.     

Complications during renal artery stent placement for atherosclerotic ostial stenosis

Purpose To describe short-term complications during stent placement for atherosclerotic renal artery ostial stenosis. Methods Sixty-one arteries in 50 patients were treated with Palmaz stents. Nineteen patients had a single functioning kidney, 23 had a bilateral stenosis, which was stented bilaterally in 11, and 8 had a unilateral stenosis. The complications were grouped as those related to the catheterization procedure, those related to stent placement, and those possibly related to either category. The complications were divided into those with severe clinical significance (SCS), those with minor clinical significance (MCS), and radiological-technical complications (RTC). The stent placement procedures were ordered chronologically according to examination date and the complications were tabulated per group of 10 patients. Results Five (10%) SCS, 5 (10%) MCS, and 8 (16%) RTC occurred in 50 patients. The catheterization procedure led to 2 SCS, 3 MCS, and 1 RTC. Stent placement gave rise to 7 RTC. Three SCS and 2 MCS could have been related to either catheterization or stent placement. More SCS occurred in the first group of 10 patients than in the following groups. Conclusion Renal artery stent placement for atherosclerotic ostial stenosis has a considerable complication rate and a learning curve is present. The complications related to the actual stent placement were without clinical consequences.     

Percutaneous transluminal angioplasty and stent placement for subclavian and brachiocephalic artery stenosis in aortitis syndrome

A 43-year-old man with progressive right common carotid, subclavian artery, and brachiocephalic artery stenoses due to aortitis syndrome is presented. The patient's right common carotid artery had been treated by percutaneous transluminal angioplasty (PTA) four times previously, but it was finally occluded. The right subclavian artery was treated by PTA once, which resulted in restenosis. The stenosis extended to the brachiocephalic artery. For this patient, PTA followed by stent placement was performed for the right subclavian and brachiocephalic artery stenosis. Because arterial stenosis is progressive in cases of aortitis syndrome, simple PTA alone does not appear to be sufficient for treatment. We suggest that PTA followed by stent placement may be an alternative treatment for recurrent stenosis in aortitis syndrome.     

Renal artery stent placement with use of the Wallstent endoprosthesis

The Wallstent endoprosthesis was placed in 12 renal arteries of 11 patients; a total of 15 stents were placed. Indications for placement were restenosis after dilation and insufficient result after dilation. In two patients, malpositioning of the stent required placement of a second stent. Complications included a case of massive cholesterol embolization and a case of unexplained transient hematuria, proteinuria, and deterioration of renal function. At repeat angiography of seven renal arteries after stent placement, one was occluded and required thrombolysis and dilation. Another showed restenosis due to shortening of the stent and required redilation and, later, placement of another stent. This stent became occluded after 1 month. In this patient and in three other cases, angiography disclosed tissue buildup in the stent but without significant stenosis after this short-term follow-up. After a clinical follow-up of 6.7 months +/- 3.4 in 10 patients treated for hypertension, three were cured, four were improved, and three were unchanged when blood pressure levels before stent placement were compared with those obtained after stent placement.     

MR evaluation of coronary stents with navigator echo and breath-hold cine gradient-echo techniques

The aim of this study was to evaluate coronary artery stents with MR. Thirty-eight patients underwent MR imaging 48.1 +/- 6.6 days (range 38-60 days) after placement of 47 coronary stents of 11 different types, using navigator echo (NE) and cine gradient-echo (GE) techniques. For both sequences the low signal artifact was used to localize the stent, whereas the flow-related high signal before and distal to the stent was considered as a patency sign. Exercise electrocardiographic test (EET) had been performed 1-7 days before MR. No adverse event with possible relation to the MR examination was observed. All the stents were recognized as signal void with GE, and all but one with NE. Of the 2 patients with positive EET, the first one, with a stent on the left anterior descending coronary artery, presented low signal distal to the stent at both MR sequences, suggesting dysfunction [60% stenosis at conventional coronary angiography (CCA)]; the second one, with two sequential stents on the right coronary artery, presented lack of signal distal to the stents at both MR sequences, suggesting occlusion (97% stenosis at CCA). For the 44 remaining stents in 36 patients with negative EET, MR high signal before and distal to the stent suggested patency at both sequences. MR seems to be a safe and promising technique for non-invasive evaluation of coronary stents.     

MR imaging-guided stent placement in iliac arterial stenoses: a feasibility study

PURPOSE: To assess the feasibility of magnetic resonance (MR) imaging-guided stent placement in iliac arterial stenoses. MATERIALS AND METHODS: Thirteen patients with 14 iliac arterial stenoses were examined prospectively. Angioplasty was performed through a femoral sheath by using a conventional 1.5-T MR imaging system. Stents and catheters were visualized on the basis of their artifacts. Nitinol stents were placed with gradient-echo MR imaging guidance. Angioplasty balloons were inflated with gadolinium-based contrast material. Results were evaluated clinically and with both digital subtraction angiography (DSA) and contrast material-enhanced MR angiography. RESULTS: Ten of 13 patients were treated with technical success by using MR imaging-guided intervention alone. Three patients were treated with additional fluoroscopic guidance, because complications (ie, panic attack, subintimal recanalization, and stent misplacement) occurred with MR guidance. The quality of the postinterventional contrast-enhanced MR angiograms of three of 12 lesions with stents was limited owing to stent-induced signal loss of the lumen. The mean stenosis degree after stent placement was significantly higher at contrast-enhanced MR angiography than at DSA (24.6% vs 6.2%). The mean MR imaging-guided procedure time was 74 minutes. CONCLUSION: MR imaging-guided stent placement in iliac arteries is feasible in select patients. The presented technique has limitations-that is, long procedure times, lack of real-time monitoring, and stent artifacts-that necessitate further modifications before it can be recommended for clinical use.     

Renal artery stenosis: preliminary results of treatment with the Strecker stent.

Use of the Strecker flexible balloon-expandable tantalum stent for treatment of renal artery stenosis after failed angioplasty or transaortic thromboendarterectomy was evaluated in 10 patients (nine hypertensive, one normotensive). Left (n = 3) and right (n = 5) renal arteries were involved; renal artery stenosis in two patients had developed after kidney transplantation. Indications for stent placement were inadequate immediate postangioplasty response (n = 7), development of considerable restenosis after angioplasty (n = 1), and obstructing intimal flaps following transaortic endarterectomy (n = 2). Stent placement was technically successful (less than 20% residual stenosis) and patency was preserved in eight patients. Of the seven hypertensive patients with successful implantation, two were cured, three had improvement, and two had no change at latest follow-up evaluation (mean, 10.6 months; range, 6-12 months). The Strecker stent may be helpful in treating restenosis after failed revascularization procedures, although the precise indication, true safety, and long-term efficacy of stent placement in renal arteries will not be known until trials with more subjects and longer follow-up periods are completed.     

Stent Placement for Treatment of Long Segment (≥80 mm) Carotid Artery Stenosis in Patients with Takayasu Disease

PurposeTo evaluate the effectiveness and safety of carotid artery stent (CAS) placement for treatment of long segment stenosis in patients with Takayasu arteritis.Materials and MethodsBetween January 2002 and February 2012, all patients with Takayasu arteritis found to have long segment (≥80 mm) carotid artery stenoses at a single institution were retrospectively analyzed. Five patients treated by CAS placement with either long or multiple self-expandable stents were included. All patients had focal neurologic symptoms, including three strokes and two transient ischemic attacks (TIAs). Six self-expanding stents were used in five patients. The mean follow-up period was 19.2 months (range, 6–30 mo); all patients had clinical evaluation, laboratory examination, and vascular imaging follow-up.ResultsImprovement in clinical symptoms was shown after successful angioplasty. There were no perioperative or in-hospital deaths. Four patients exhibited persistent relief, and repeated angiography or computed tomography (CT) angiography showed normal flow. One patient stopped taking her medications after CAS placement and became symptomatic 8 months later as a result of a severe in-stent stenosis.ConclusionsCAS placement was shown to be a feasible option for treating long segment (≥80 mm) stenosis of carotid arteries in patients with Takayasu arteritis with encouraging results.     

肝移植术后并发症与介入治疗四、门静脉并发症

肝移植术后门静脉供血障碍性并发症主要为门静脉狭窄和门静脉血栓形成,虽然发生率不高,但临床危害大,一经确诊,需积极处理。彩色多普勒血流显像可作为检测门静脉血流的首选方法,对确诊有功能意义的狭窄还需依赖血管造影。对于门静脉狭窄行球囊扩张术以及支架置入术可有效降低门脉压力,而门静脉血栓形成的病例可用药物溶栓、机械碎栓和支架置放术相结合进行治疗,必要时可行TIPS降低门脉压力。     

食管肿瘤引起的气管狭窄支架置入治疗

目的探讨气管内支架置入治疗由食管肿瘤或食管金属内支架放置术后引起的气管狭窄的疗效和安全性。方法本组11例气管狭窄患者,8例由食管恶性肿瘤引起,3例为食管金属内支架放置术后压迫气管造成。X线透视下在气管内共植入11枚镍钛合金支架,其中7枚为裸支架,4枚为带膜支架。支架直径16～18mm,长度40～60mm。结果所有患者均成功置入内支架(成功率100%)。术后患者气促、呼吸困难和窒息感均立即缓解或消失,血氧饱和度上升。部分患者在术后1～3d可有少量咳嗽和血痰,经对症治疗后消失,无其他并发症。结论采用气管内金属内支架置入的方法治疗由食管恶性肿瘤或食管金属内支架放置术后引起的气管狭窄是一种作用迅速且安全、有效的方法。