黄韧带剥离法治疗退行性腰椎管狭窄症

采用黄韧带剥离法治疗退行性腰椎管狭窄症39例,经术后平均2年10个月的随访,优28例,良9例,可2例,无差级病例,优良率95％。本手术的特点是潜行剥离切除椎板下及侧隐窝黄韧带,达到椎管扩大减压之目的。手术能做到减压彻底、骨性结构破坏小,利于病人的术后康复及脊柱的稳定。结果显示该术是治疗退行性腰椎管狭窄症的一种行之有效的方法。     

Surgical treatment of laryngotracheal stenosis in infants and children

Summary Laryngotracheal stenosis in children is difficult to manage, especially in cases of acquired lesions. Of 317 cases reviewed, 75 surgical cases are reported here: 28 were congenital and 47 acquired, mostly due to endotracheal intubation. A large variety of laryngotracheoplasty techniques have been used in reconstruction, depending on the age and status of the patient, the size of the laryngeal lumen, the exact site of the stenosis and any associated anomalies. The three main techniques used have been described by Evans, Cotton, and Rethi, Stenting relied on Silastic rolls, Montgomery T-tubes and Aboulker Teflon prostheses. The results in 65 patients showed a decannulation rate of 92% in cases of congenital stenosis and 80% in acquired ones. Improvements in therapy still seem necessary in order to reduce the cannulation time following treatment and the sequelae producing dysphonia.Presented at the First European Congress of Oto-Rhino-Laryngology and Cervico-Facial Surgery, Paris 26–29 September 1988     

Use of an introducer sheath for colonic stent placement

We describe a technical modification of Wallstent implantation for the treatment of malignant rectosigmoid and descending colonic obstructions. The modification is the routine placement of an introducer sheath via the rectum before stent implantation in order to straighten the rectosigmoid region. This device facilitates catheter and guide wire manipulations and obtaining specimen biopsies for histopathological studies. The introducer sheath has been used without complications in 21 consecutive patients.     

Flow patterns from metallic vascular endoprostheses: in vitro results

The aim of this study was to determine flow characteristics and pressure gradients of different balloon- and self-expandable stents in an in vitro flow-model. Seven vascular stents (Bridge, Cragg, Memotherm, Palmaz PS 784, Sinus, Symphony, Wallstent), equal in length (60 mm) and diameter (10 mm), were deployed in a closed flow model. The inner diameter of the tube measured 9 mm. Flow at 1.5 and 6 l/min was applied. Flow patterns were visualized by anionic particles illuminated with two helium-neon lasers. Late laminary flow characteristics and pre- /post-stent pressure gradients were determined in either expanded stent, 25 and 50 % tube stenosis. Stent implantation induced a decrease of laminary flow when compared with an unstented tube with and without concentric 25 % stenosis (p < 0.01) at all flow rates and an increase of pressure gradients when compared with an unstented tube for a flow rate of 6 l/min and all stenoses (p < 0.01). At 1.5 l/min most stents revealed no significant change of pressure gradient, the highest gradient measured 4.0 mmHg. Sinus permitted maximum (expanded: 82.1 % and 76.9 % at 25 % stenosis at 1.5 l/min; p < 0.01) and Palmaz minimum of laminary flow at all flow rates and stenoses (70.2 and 52.4 % at 25 % stenosis at 1.5 l/min; p < 0.01). At 6 l/min, when completely expanded, Sinus is equal to Bridge and Memotherm; in 25 % stenosis Sinus is equal to Bridge, Memotherm, and additionally to Cragg and Wall. None of the endoprostheses revealed laminary flow at 50 % stenosis. Inadequate stent deployment bears the risk of creating less laminary flow and pressure gradients. Since flow disturbances and pressure gradients may influence neointimal hyperplasia, stent design and completeness of stent expansion are important factors regarding the appearance of thrombus formation and postinterventional restenosis. Received: 27 April 2000 Revised: 20 July 2000 Accepted: 26 July 2000     

Effect of an experimental stenosis in the porcine descending thoracic aorta

OBJECTIVE: To investigate the alterations of mechanical properties in pre- (A) and post- (B) stenotic aortic regions after an experimentally induced stenosis in the descending thoracic aorta. METHODS: Eight healthy, normalipemic and normotensive Landrace pigs were subjected to thoracotomy under sterile conditions. In the upper segment of the descending thoracic aorta a circumferential symmetric constriction 5 mm in length was imposed and stabilized; thus, a 15-20 mm Hg pressure gradient was established. The pressure gradient was verified via catheterization of the vessel with pressure tip catheters. Pre- and poststenotic hemodynamic disturbances were recorded by the use of a bidirectional Doppler flowmeter. Pressure and flow measurements were carried out before, 10 min after, and 90 days after the creation of the stenosis. Euthanasia was performed after 90 days, and the descending thoracic aorta removed. In the A and B regions serial sections of aorta (5 mm in length) create appropriate aortic "rings," to test in a uniaxial tension device, in order to determine the mechanical properties of the vessel. Histological analysis was performed, so as to estimate the content (%) of collagen and elastin fibers within the aortic wall. Eight sham-operated pigs were used as controls. RESULTS: Reverse blood flow was recorded at both the A and B sites, and was maintained until euthanasia. Reverse flow in the poststenotic region B was greater than that in the prestenotic region. Mechanical analysis showed that the aortic wall in A and B regions became stiffer particularly at high strains (P < 0.05). Histological analysis indicated that the percentage of elastin fibers remained almost the same in both regions while the percentage of collagen fibers increased considerably, especially in the B region (P < 0.05). CONCLUSIONS: A nonhemodynamically significant experimental stenosis located at the level of the descending thoracic aorta induced reverse blood flow before and after the stenosis. The higher the reverse flow, the more collagen fibers were produced and the stiffer the aortic wall. Since hypercholesterolemia can be ruled out as a hardening factor in the present study, disturbed flow seems to be an independent factor which activates fibroblasts to overproduce collagen and to eventually reduce the aorta's compliance.     

Percutaneous treatment of superior vena cava syndrome using metallic stents

The purpose of this study was to evaluate the results of treatment of superior vena cava syndrome (SVCS) in patients with benign and malignant disease using expandable metallic stent. From January 1995 to April 2000, 87 expandable stents were implanted in 82 patients (59 men, 23 women; mean age 57.8 years, age range 39–79 years) for the treatment of SVCS. The SVCS was defined as symptomatic bilateral obstruction of venous drainage from head, neck and upper extremities. In 68 patients SVCS was due to malignant neoplasia, and in 14 cases it was due to benign aetiology. All patients were treated with expandable stent. We implanted 81 Wallstent prostheses and 6 Palmaz stents. Adjuvant thrombolysis was applied in 12 patients who required fibrinolysis. After recanalization, the stent was implanted in all cases in SVC (infra- or supra-azygos vein). All patients were treated with heparin of low molecular weight (HBPM) during 6 months. Patency was analyzed according to clinical symptoms and Doppler US or venograms exploration. Technical success was observed in all cases. Clinical success was reached in 78 of 82 patients (95.1%) (absence of symptoms in 2 or 3 days). Four patients suffered immediate thrombosis which required fibrinolitic treatment with a new prosthesis placement in 1 case. The follow-up for the malignant process was of 7.1 months (range 1–39 months) and in benign cases was 31.2 months (range 11–61 months). Sixty-two (91.1%) patients with malignancy died without SVCS symptomatology. All the patients with benign pathology are alive. Clinical primary patency in malignant cases was 87% with assisted patency of 96.2%. Endovascular therapy using metallic stent and thrombolysis is a successful method to treat SVCS due to benign or malignant aetiology. Electronic Publication     

Intraarterial pressure gradients after randomized angioplasty or stenting of iliac artery lesions

Purpose To determine initial technical results of percutaneous transluminal angioplasty (PTA) and stent procedures in the iliac artery, mean intraarterial pressure gradients were recorded before and after each procedure. Methods We randomly assigned 213 patients with typical intermittent claudication to primary stent placement (n=107) or primary PTA (n=106), with subsequent stenting in the case of a residual mean pressure gradient of >10 mmHg (n=45). Eligibility criteria included angiographic iliac artery stenosis (>50% diameter reduction) and/or a peak systolic velocity ratio >2.5 on duplex examination. Mean intraarterial pressures were simultaneously recorded above and below the lesion, at rest and also durign vasodilatation in the case of a resting gradient ≤10 mmHg. Results Pressure gradients in the primary stent group were 14.9±10.4 mmHg before and 2.9±3.5 mmHg after stenting. Pressure gradients in the primary PTA group were 17.3±11.3 mmHg pre-PTA, 4.2±5.4 mmHg post-PTA, and 2.5±2.8 mmHg after selective stenting. Compared with primary stent placement, PTA plus selective stent placement avoided application of a stent in 63% (86/137) of cases, resulting in a considerable cost saving. Conclusion Technical results of primary stenting and PTA plus selective stenting are similar in terms of residual pressure gradients.     

Mapping spatial and temporal changes in carotid atherosclerosis from three-dimensional ultrasound images

This study was designed to evaluate changes in carotid atherosclerosis using plaque and wall thickness maps derived from three-dimensional ultrasound (3DUS) images. Five subjects with carotid stenosis were scanned at baseline and 3 mo as part of a placebo-controlled intensive statin treatment study and three subjects with moderate atherosclerosis were scanned at baseline and again within 14 +/- 2 d. 3DUS-derived vessel wall volume (VWV) was measured using manual segmentation to provide segmentation contours that were used to generate scan and rescan carotid atherosclerosis thickness maps and thickness difference maps. There was no significant difference in VWV between scan and rescan for the three subjects scanned twice in 2 wk or the single subject treated with placebo. There was a significant difference between scan and rescan VWV for carotid stenosis subjects treated with atorvastatin (p < 0.001). Carotid atherosclerosis thickness difference maps showed visual qualitative evidence of thickness changes in vessel wall and plaque thickness in the common carotid artery for all statin-treated subjects and no change in a placebo-treated subject and subjects scanned twice in 2 wk. Carotid atherosclerosis thickness difference maps generated from 3DUS images provide evidence of vessel wall and plaque thickness changes for all subjects assessed.