New Volumetric Analysis Method for Stent Expansion and its Correlation With Final Fractional Flow Reserve and Clinical Outcome: An ILUMIEN I Substudy

Objectives

This study sought to compare conventional methodology (CM) with a newly described optical coherence tomography (OCT)-derived volumetric stent expansion analysis in terms of fractional flow reserve (FFR)-derived physiology and device-oriented composite endpoints (DoCE).

Exercise Function of Children with Congenital Aortic Stenosis Following Aortic Valvuloplasty during Early Infancy

Objectives. The objectives of this study were to characterize the exercise function of patients treated with balloon aortic valvuloplasty at ≤6 months of age, and identify factors associated with exercise dysfunction. Background. Balloon aortic valvuloplasty is the primary therapy for neonatal aortic stenosis (AS). Residual and/or acquired abnormalities of left heart structure and function may adversely affect exercise capacity. Methods. We prospectively recruited patients >6 years old with a history of neonatal AS to undergo exercise testing. Results. We enrolled 30 patients (median age 13.1 years) who underwent balloon aortic valvuloplasty at a median age of 12 days. At time of exercise testing, the median maximum Doppler AS gradient was 34 mm Hg (0–70 mm Hg); 11 patients had moderate or severe aortic regurgitation. All patients were asymptomatic. Overall, peak oxygen consumption (VO₂) was below normal (87 ± 18% predicted; P < .001), and was severely depressed (≤70% predicted) in 7 patients (23%). Although peak O₂ pulse was well preserved overall (97 ± 22% predicted; P= .36), 11 patients had an O₂ pulse <85% predicted, including all patients with VO₂≤ 70% predicted. Peak heart rate was below normal overall (91 ± 7% predicted, P < .001), but severe chronotropic dysfunction (≤70% predicted) was rare (n = 1). Age at testing correlated inversely with peak VO₂ (R²= 0.30; P= .002). No other demographic, historical, or echocardiographic variables were associated with peak VO₂. Conclusion. Although exercise function is preserved in most patients with a history of AS treated in early infancy, a subset have markedly reduced peak VO₂, usually because of inability to increase stroke volume.     

再次经皮球囊二尖瓣成形术39例远期疗效观察

目的 观察经皮球囊二尖瓣成形术后再狭窄的患者,行再次经皮球囊二尖瓣成形术的远期疗效.方法 39例经皮球囊二尖瓣成形术后再狭窄的患者,全部采用改良Inoue法,再次行经皮球囊二尖瓣成形术,并进行远期疗效随访.结果 39例患者再次行经皮球囊二尖瓣成形术,成功36例(成功率为92.3%).再次经皮球囊二尖瓣成形术成功后,患者临床症状及部分血流动力学指标(左心房平均压、二尖瓣瓣口面积、跨瓣压差及肺动脉收缩压)明显改善[分别为(24.50±6.54)mm Hg比(9.66±4.21)mill Hg(1 mm Hg=0.133 kPa),(1.05±0.19)cm2比(2.23±0.22)cm2,(17.03±4.52)mm Hg比(7.79±4.07)mm Hg,(58.12±12.68)mm Hg比(31.45±10.02)mm Hg,P均＜0.05];而左心房内径无明显改变[(4.71±0.75)cm比(4.07±0.69)cm,P＞0.05]. 36例患者再次经皮球囊二尖瓣成形术后随访12～146(69±23)个月,远期随访可见二尖瓣瓣121面积仍明显大于术前[(2.02±0.21)cm2比(1.05±0.19)cm2,P＜0.05],跨瓣压差明显小于术前[(9.15±4.11)mm Hg比(17.03±4.52)mm Hg,P＜0.05],且均与近期随访结果相近似[分别为(2.02±0.21)cm2比(2.23±0.22)cm2,(9.15±4.11)mm Hg比(7.79±4.07)mm Hg,P均＞0.05];而左心房内径仍无明显改变[(4.13±0.71)cm比(4.07±0.69)cm,P＞0.05].远期随访期间,大多数患者心功能及生活质量均明显改善.结论 对于经皮球囊二尖瓣成形术后再狭窄的患者,只要病例选择恰当,手术操作正确,再次行经皮球囊二尖瓣成形术的近期及远期疗效均佳.     

Murine M2-10B4 and SL/SL cell lines differentially affect the balance between CD34+ cell expansion and maturation

The ability of bone marrow stroma to modulate hematopoietic progenitor cell expansion is of considerable interest for gene transfer strategies and transplantation of limited stem cell numbers. We compared the capacity of 2 murine stromal cell lines to affect the balance between maturation and proliferation of human CD34+ cells in short-term expansion cultures. In 7-day serum-free cultures, cytokine-induced amplification of granulocyte-macrophage colony-forming cells (CFC-GM), erythroid burst-forming units (BFU-E), and total cells was significantly increased by the presence of genetically engineered Sl/Sl and M2-10B4 stromal cells in a 1:1 ratio (Sl/M2 cells) compared with stroma-free cultures (P < .05). Sl/M2 cultures generated 21-fold more mature CD15+ cells than stroma-free cultures, without further amplifying the number of CD34+ cells. The addition of serum led to a further increase of CFC-GM, total cells, and CD15+ cells, whereas BFU-E were no longer maintained. Pure Sl/Sl stromal layers were likewise superior to stroma-free cultures in expansion of CD34+ cells and total cells when serum was present. However, the differentiation of CD34+ cells was less pronounced in Sl/Sl cultures compared with Sl/M2 layers, as demonstrated by a lower content of CD15+ cells. Neutralization experiments revealed differential contributions of Flt3 ligand and thrombopoietin to the support of total cell and CFC expansion by Sl/M2 and Sl/Sl stromal feeders.     

Hypertension of Kcnmb1−/− is linked to deficient K secretion and aldosteronism

Mice lacking the β1-subunit (gene, Kcnmb1; protein, BK-β1) of the large Ca-activated K channel (BK) are hypertensive. This phenotype is thought to result from diminished BK currents in vascular smooth muscle where BK-β1 is an ancillary subunit. However, the β1-subunit is also expressed in the renal connecting tubule (CNT), a segment of the aldosterone-sensitive distal nephron, where it associates with BK and facilitates K secretion. Because of the correlation between certain forms of hypertension and renal defects, particularly in the distal nephron, it was determined whether the hypertension of Kcnmb1^−/− has a renal origin. We found that Kcnmb1^−/− are hypertensive, volume expanded, and have reduced urinary K and Na clearances. These conditions are exacerbated when the animals are fed a high K diet (5% K; HK). Supplementing HK-fed Kcnmb1^−/− with eplerenone (mineralocorticoid receptor antagonist) corrected the fluid imbalance and more than 70% of the hypertension. Finally, plasma [aldo] was elevated in Kcnmb1^−/− under basal conditions (control diet, 0.6% K) and increased significantly more than wild type when fed the HK diet. We conclude that the majority of the hypertension of Kcnmb1^−/− is due to aldosteronism, resulting from renal potassium retention and hyperkalemia.     

Sequential Endoscopic Papillary Balloon Dilatation Following Limited Sphincterotomy for Common Bile Duct Stones

Endoscopic papillary balloon dilatation (EPBD) has been recently used in conjunction with endoscopic sphincterotomy (EST) for the removal of common bile duct (CBD) stones. The present study was aimed at assessing the safety and outcome of sequential EPBD following EST for CBD stones. A total of 74 patients (43 females, mean age 41 years) with ≥10-mm stone(s) in the CBD were selected for the procedure, which included limited EST followed by EPBD with balloon dilators of 10–18 mm in size. Eleven patients had undergone EST and unsuccessful stone removal earlier. Forty-nine patients had symptoms of CBD stones, while 25 were detected on imaging. Eleven patients had previous CBD stent in situ and four had T-tube in situ. The stone size was 10–12 mm in 34, 13–14 mm in 26, and ≥15 mm in 14 patients. Thirty-one patients had a single stone, while 43 had ≥2 stones. The successful removal of stones was achieved in 68 (91.9%) patients; 62 in the first attempt, five in the second, and one in the third. Six patients were deemed to be “failures.” In two of them, the stones could be removed after mechanical lithotripsy. Complications were seen in 16 patients, with self-limiting pain in 13, self-limiting ooze in five, melaena in one, and mild pancreatitis in two. One patient had impaction of the dormia basket. We conclude that EPBD following EST is safe and effective in removing stones ≥10 mm in size in over 90% of patients.     

Balloon overtube-guided colorectal endoscopic submucosal dissection

AIM: To evaluate the usefulness of a balloon overtube to assist colorectal endoscopic submucosal dissection (ESD) using a gastroscope.METHODS: The results of 45 consecutive patients who underwent colorectal ESD were analyzed in a single tertiary endoscopy center. In preoperative evaluation of access to the lesion, difficulties were experienced in the positioning and stabilization of a gastroscope in 15 patients who were thus assigned to the balloonguided ESD group. A balloon overtube was placed with a gastroscope to provide an endoscopic channel to the lesion in cases with preoperatively identified difficulties related to accessibility. Colorectal ESD was performed following standard procedures. A submucosal fluid bleb was created with hyaluronic acid solution. A circumferential mucosal incision was made to marginate the lesion. The isolated lesion was finally excised from the deeper layers with repetitive electrosurgical dissections with needle knives. The success of colorectal ESD,procedural feasibility, and procedure-related complications were the main outcomes and measurements.RESULTS: The overall en bloc excision rate of colorectal ESD during this study at our institution was 95.6%.En bloc excision of the lesion was successfully achieved in 13 of the 15 patients (86.7%) in the balloon overtube-guided colorectal ESD group, which was comparable to the results of the standard ESD group with better accessibility to the lesion (30/30, 100%, not statistically significant).CONCLUSION: Use of a balloon overtube can improve access to the lesion and facilitate scope manipulation for colorectal ESD.     

Successful weaning from mechanical ventilation following balloon mitral commissurotomy

Successful weaning from mechanical ventilation (MV) following percutaneous balloon mitral commissurotomy (BMC) is reported in a 59-year-old woman with severe symptomatic rheumatic mitral stenosis. The patient was admitted to the Intensive Care Unit for acute respiratory failure secondary to pulmonary edema requiring intubation and mechanical ventilation. After resolution of the acute phase, she became completely dependent on mechanical ventilatory support. In spite of the reinforcement of conventional therapy (diuretics, digitalis, vasodilators), weaning attempts were unsuccessful because of persisting elevated left atrial pressure. Percutaneous BMC was performed with favorable hemodynamic results, allowing the removal of external ventilatory support 24 h later and discharge from the Intensive Care Unit the same day. Received: 27 August 1996 Accepted: 29 May 1997