The geometry of triple-balloon dilation

Triple-balloon dilation (TBD) of a variety of luminal structures has been successfully, though infrequently, used. A mathematical model is presented for the selection of balloon sizes, and equations and tables are derived that allow the user to estimate more accurately the size of balloons needed for TBD of structures with large lumina. With TBD, an approximately circular lumen can be formed. Also, TBD allows smaller, higher-pressure balloons to be used instead of single, low-pressure, large balloons. However, multiple puncture sites may be required for TBD.     

Percutaneous dilation of benign biliary strictures

Percutaneous balloon dilation of benign biliary strictures was successful in 15 of 18 patients in whom the procedure was attempted. Successful dilation was achieved in nine of 11 patients who had biliary enteric strictures, with follow-up of 22-55 months (mean, 35.4 months) after catheter removal in seven patients. Five of six strictures in the biliary tree that developed after surgery were successfully dilated, with long-term follow-up available in two patients (58 and 42 months). A patient with an inflammatory common bile duct stricture that was successfully dilated was followed up for 18 months. Percutaneous dilation of biliary tract strictures is a promising technique with good long-term results and may be the initial treatment of choice in biliary stricture management.     

经皮球囊肺动脉瓣成形术治疗单纯性肺动脉瓣狭窄32例

目的 总结1995～2001年我院用经皮球囊肺动脉瓣成形术治疗单纯性肺动脉瓣狭窄32例的经验。方法 本院住院患者32例,单纯性肺动脉瓣狭窄采用经皮球囊肺动脉瓣成形术治疗。结果 本组32例右室收缩压:术前(93.5±28.5)mmHg,术后(42±9.0)mmHg;跨肺动脉瓣压力阶差:术前(76±30)mnHg,术后(24.5±8.5)mmHg;术后跨肺动脉瓣压力阶差<25mmHg达90.6％。结论 经皮球囊肺动脉瓣成形术治疗单纯性肺动脉瓣狭窄是安全有效的,病例和手术方法的选择,精确测定肺动脉瓣直径和选择大小合适的球囊是手术成功的重要环节。     

Esophageal strictures: balloon dilation

One hundred seventy transnasal balloon catheter dilation procedures were performed in 35 patients with esophageal strictures to assess the efficacy and safety of the procedure. On the average, five dilations were required per patient. Depending on the cause of the esophageal stricture, success rates for the technique ranged from 67% to 87%, with success defined as the resolution of dysphagia to both fluids and solids. Three complications, all perforations, were seen; one perforation required surgical repair. No procedure-related deaths were identified in this series. Balloon catheter dilation can be safely applied to esophageal strictures from a variety of causes, with a high degree of clinical success.     

乳腺导管囊性扩张症的超声诊断

我院2000年8月～2003年11月经手术病理证实乳腺导管扩张症48侧，现就其超声诊断报告进行回顾性的分析，旨在提高超声检查对乳腺导管囊性扩张症的诊断和鉴别诊断。     

Stability and reproducibility of brachial artery flow-mediated dilation

PURPOSE: Brachial artery flow-mediated dilation (BAFMD) is a noninvasive technique, which has been suggested as a potential means of identifying patients with early atherosclerosis and therefore has enormous clinical appeal. Despite this, the stability and reproducibility of this technique are not yet clear. Therefore, the purpose of this study was to establish the stability and reproducibility of BAFMD after 5 min of forearm occlusion and to produce power calculations to aid in clinical trial design. METHODS: Twenty-six healthy volunteers underwent high-resolution ultrasonographic brachial artery assessments before, during, and after 5 min of forearm occlusion. The study design involved three scans on 2 d, performed by two ultrasonographers and analyzed by two readers. All subjects were tested between 7 and 11 a.m. after refraining from food and exercise. The nondominant arms were scanned, in longitudinal view, approximately 4 cm proximal to the olecranon process, in the anterior/medial plane. Blood draws were performed on each visit. The SAS MIXED restricted maximum likelihood (REML) procedure for an unbalanced design was used to calculate variance components and provide power calculations. RESULTS: Average baseline artery diameter for all studies was 3.48 +/- 0.53 mm. This increased to 3.71 +/- 0.57 mm (6.58 +/- 4.15%) at peak dilation. Intraclass correlation coefficients (ICCC) for days, testers, and readers were 0.92, 0.94, and 0.90, respectively. To detect a difference in vasoreactivity of 60% (two-tailed), e.g., 5% vasodilation versus 8% vasodilation, at 90% power, 23 and 10 subjects would be required for cross-sectional and pre-post designs, respectively. CONCLUSIONS: These data indicate adequate stability and reproducibility of the BAFMD technique under controlled conditions. Additionally, BAFMD appears useful to differentiate between groups, although its prognostic value for the examination of individuals is unclear.     

Secondary ureteropelvic junction stricture: percutaneous dilation

Percutaneous incision and balloon catheter dilation of the ureteropelvic junction (UPJ) was performed in nine patients with secondary UPJ strictures. In all patients, the UPJ was successfully dilated, and no immediate complications were encountered. After a postoperative follow-up period of 4-27 months, six patients showed marked improvement on excretory urograms. Three patients had recurrent obstruction after 3-18 months. The 66% success rate of percutaneous balloon dilation with or without endopyelotomy compares favorably with the success rate of open surgical repair of secondary UPJ strictures in adults.     

Prostatic urethra: experimental dilation in dogs

An animal study was undertaken to develop a balloon dilation technique that could be used in humans to treat the common ailment of benign prostatic hypertrophy. Dogs were used as a model because of the similarities in the prostate between the two species and the ready availability of the canines. A retrograde transurethral approach was used for dilation. Balloon catheters, 8-20 mm in diameter, were used. Significant, long-lasting dilatation of the prostatic urethra was not accomplished until 20-mm balloons (or two 10-mm ones) inflated for 10 minutes were used. The animals were followed for up to 14 months. No deleterious histologic effects of dilation were identified within the urethra or prostate that could lead to stenosis of the prostatic urethra in later stages.     

Atretic esophagus: transgastric balloon-assisted hydrostatic dilation

Esophageal atresia may be associated with a long interval or gap between the upper and lower pouches. Despite a variety of procedures to elongate the esophagus, surgeons have been unable to achieve esophageal continuity in many patients. Three infants with esophageal atresia and long gaps recently underwent hydrostatic dilation of the distal esophageal pouch followed by primary anastomosis. The technique entailed passing a balloon-tipped catheter through a gastrostomy site to the distal esophageal pouch. The balloon was inflated to a diameter sufficient to occlude the distal esophagus. Dilute contrast material was then infused under fluoroscopic visualization to a maximal pressure of 145 cm H2O. Dilations were performed daily over a 2-week period, followed by surgery. Primary anastomosis was accomplished in all patients. The promising results in these patients should stimulate other investigators to assess this technique in infants with this challenging surgical problem.     

Brachiocephalic artery dilation by percutaneous transluminal angioplasty

Percutaneous transluminal angioplasty (PTA) was used to dilate stenotic lesions in 38 brachiocephalic arteries in 36 patient. Complete evaluation of the central nervous system blood supply is a prerequisite for the brachiocephalic PTA when cerebral symptoms are present. The femoral artery is the best vascular entry site; use of digital subtraction angiography equipment for arterial mapping is helpful. Balloon diameter should be the same as or slightly wider than the diameter of the normal artery adjacent to the stenotic segment. Spasm was successfully treated with intraarterial injection of nitroglycerin. The only drug therapy consistently used with PTA was aspirin. Complete dilation of the stenosis is the best prevention of thrombotic or embolic complications. In properly selected cases, proximal subclavian artery stenoses can be safely dilated, and the balloon can eventually be placed across the origin of the vertebral artery. Because of potential complications associated with brachiocephalic PTA, indications must be well established, and interventions should not be performed on marginal or asymptomatic stenoses.     

Balloon catheter dilation of ureteroenteric strictures: long-term results

Balloon catheter dilation of benign ureteroenteric anastomotic strictures has been proposed as an alternative to either surgical revision or chronic ureteral stenting, with moderately successful short-term results reported by several groups in a limited number of patients. However, the authors' experience with 29 patients exhibiting 37 benign ureteroenteric strictures treated over the past 7 years revealed that in the majority of cases (23 patients, 26 strictures [70%]), strictures recurred within 6 months of balloon catheter dilation/ureteral stent therapy. Furthermore, of the 11 strictures that appeared to have been successfully dilated at a follow-up interval of 6 months, five restenosed within 1 year. Therefore, only six of 37 (16%) ureteroenteric stricture dilations could be considered successful when viewed at least 1 year after interventional therapy. Furthermore, repeat dilations have often been required to maintain ureteral patency in these patients.     

Percutaneous dilation of ureteral strictures in renal transplant patients

Percutaneous dilation of benign ureteral strictures was performed as an alternative to surgical therapy in 14 patients with renal transplants. Dilations were performed with balloon catheters in 13 patients and with a tapered angiographic catheter in one patient. Eleven strictures were successfully dilated (79%). There were three recurrences (21%). Follow-up in nine of the 11 successful cases ranged from 12 to 61 months (mean, 29 months; median, 24 months). There were no complications directly related to balloon dilation. The high success rate in this series may be related to the early diagnosis of strictures in these closely followed patients.     

Percutaneous balloon dilation angioplasty of pulmonary artery branch stenosis

Congenital or acquired branch pulmonary artery stenosis can produce significant right ventricular hypertension and complicate the management of patients with tetralogy of Fallot. Repair is difficult using conventional surgical techniques. Balloon dilation angioplasty may be beneficial to some patients with these lesions. The technique currently used at the University of Minnesota is described. Results indicate that half of attempted dilations are successful with increased diameter of the narrowed areas, decreased pressure gradient, and improved pulmonary blood flow to the involved lung. Failure may be caused by technical limitations (28%) or lesions that are not dilatable with current equipment (22%). Undilatable lesions are more common in children over 2 years of age, in isolated pulmonary artery stenosis, and with associated surgical shunts. Complications are uncommon.     

MR enterography in the evaluation of small bowel dilation

Magnetic reasonance (MR) enterography enables high contrast resolution depiction of the location and cause of bowel obstruction through a combination of predictable luminal distension and multiplanar imaging capabilities. Furthermore, because the patient is not exposed to ionizing radiation, sequential “dynamic” MR imaging can be performed repeatedly over time further facilitating depiction of the site and/or the cause of obstruction. With increasing availability of MR imaging and standardization of the oral contrast medium regimens, it is likely that this technique will assume an ever-increasing role in the evaluation of small bowel dilation in the coming years. We illustrate the utility of MR enterography in the evaluation of small bowel dilation, whether it be mechanical, functional (e.g., ileus), or related to infiltrative mural disease.     

超声评价冠心病患者血管内皮依赖性舒张功能

目的：探讨肱动脉内皮依赖性舒张功能（EDD）对冠心病（CAD）的诊断价值。方法：对189例连续冠脉造影（CAG）受检者术前利用高频超声进行肱动脉EDD检查，并与CAG结果进行相关性研究。结果：CAD单支病变组、多支病变组肱动脉EDD明显低于对照组（P〈0．01）；多支病变组EDD显著低于单支病变组（P〈0．01）。结论：CAD患者及具有其危险因素人群中，进行EDD检查，可间接反映冠状动脉情况，不仅为早期发现、预防和治疗CAD患者提供依据，还可作为监测和评估病情变化的指标。