Intracardiac echocardiography via the transvenous approach with use of 8F 10-MHz ultrasound catheters

OBJECTIVE

To study the safety and feasibility of intracardiac imaging using a novel 8F 10-MHz non-over-the-wire ultrasound catheter system.

SUBJECTS AND METHOD

Intracardiac imaging using a transfemoral venous approach was performed in 33 adults, 14 men and 19 women, aged 25 to 66 years (mean, 46 years). Six were normal subjects, 12 had congenital heart diseases (5 atrial septal defects, 3 ventricular septal defects, 1 tetralogy of Fallot, 2 patent ductus arteriosus, and 1 Ebstein anomaly), 14 had valvular heart diseases (12 mitral stenoses and 2 calcific aortic stenoses), and 1 had acute pulmonary embolism.

RESULTS

Ultrasound images were obtained, without any complications, from the right side of the heart in all subjects. The atria and ventricles could be recognized by anatomic relationships to the cardiac chambers and the valves by their characteristic motion during each cardiac cycle. The vessels were verified by their connections to the cardiac chamber and by contrast echocardiography if indicated.

CONCLUSION

Intracardiac imaging using the 8F 10-MHz non-over-the-wire ultrasound catheter system via a transfemoral venous approach is feasible and safe. Intracardiac echocardiography is potentially useful for assessing a variety of cardiac anomalies and in guiding and monitoring certain intervention procedures.

Complications of Inoue balloon mitral commissurotomy: impact of operator experience and evolving technique

BACKGROUND

There have been no single-center studies that have systematically addressed the acute outcome of Inoue balloon mitral commissurotomy (BMC) performed in a large series of patients. Accordingly, this study sought to examine the impact of operator experience and continuing technical modifications on the success and complication rates of BMC.

METHODS

BMC was performed in 799 patients: 469 patients with pliable mitral valves (group 1) and 330 patients with calcified valves and/or severe subvalvular disease (group 2). Acute complications were examined and compared between groups before and after modifications in BMC techniques. Major modifications included the use of a height-derived balloon sizing method for the selection of an appropriate balloon catheter, a cautionary stepwise dilation technique, and avoidance of traction on the interatrial septum during balloon inflations.

RESULTS

Technical failures were encountered in 4 (0.5%) patients in our early experience. One patient sustained cardiac perforation and tamponade and was the only case requiring emergency surgery. There were no deaths. Systemic embolic events were observed in 11 (1.4%), all among the first 353 patients before the routine use of pre-BMC transesophageal echocardiography. Severe postprocedure angiographic (>/=3+) mitral regurgitation occurred in 4% of patients, 2% in group 1 versus 9% in group 2 (P =.0001). With increased operator experience and technical modifications, this complication was significantly reduced from 5% (7 of 150 patients) to 0% in the last 316 patients in group 1 (P =.0001) and from 11% (26 of 228 patients) to 3% (3 of 101 patients) in group 2 (P =.031). The incidence of significant interatrial shunting (pulmonary-to-systemic flow ratio >/=1.3) was also significantly reduced from 12% to 6% (P =.0034).

CONCLUSION

Incremental operator experience and ongoing technical refinements in BMC techniques have resulted in a 100% technical success rate and a significant diminution in complications in patients with a wide spectrum of stenotic mitral valve morphologic features.

Immediate and mid-term results after MultiLink stent implantation in native coronary arteries

Different stent designs have widely disparate characteristics that may exert a positive or negative impact on their early and mid-term outcomes. The MultiLink stent (Guidant/Advanced Cardiovascular Systems, Santa Clara, CA) is a new coronary stent with only very limited data. In this report, we examined the results of 50 consecutive patients treated with 57 premounted sheathless MultiLink stents in 53 native coronary arteries with reference diameter > or =2.7 mm. Successful stenting was achieved in 98% of patients, resulting in an improvement in diameter stenosis from 91%+/-11% to 1%+/-3% (P = 0.0001). At 1 month, there was no death, myocardial infarction, or stent thrombosis. Angiographic restudy at a mean of 5.0+/-1.8 months in 94% of patients revealed an in-stent restenosis rate of 20.7%. The restenosis rates for diabetic patients (vs. nondiabetic patients), type C lesions (vs. type A/B1 lesions), and the use of 35-mm-long stents (vs. 15-mm-long stents) were 45.4% (14.3%), 56% (< or =11%), and 80% (8.8%), respectively (P < 0.05). In conclusion, the present study demonstrates that the MultiLink stent has an excellent performance profile, is associated with a low risk of stent thrombosis in native coronary vessels, and yields a favorable restenosis rate, particularly after the use of short (15 mm) stents to treat simple lesions.

Angiographic restenosis rate in patients with chronic total occlusions and subtotal stenoses after initially successful intracoronary stent placement

The 5-month angiographic in-stent restenosis rate did not differ between patients with chronic total occlusions (n = 43) and subtotal stenoses (n = 43) equally matched for diabetes status, exact stent design, final expanded stent diameter, stent length, and residual percent diameter stenosis after stent placement; it was 32.5% and 27.9% for those with chronic total occlusions and subtotal stenoses, respectively (p = 0.638). Furthermore, the stent occlusion rate (4.6% vs 6.9%, respectively) was low in both patient groups.

Ki-ras codon 12 point mutational activation in Hong Kong colorectal carcinoma patients

This study investigated the frequency and importance of Ki-ras codon 12 mutations in 99 Hong Kong Chinese colorectal carcinoma specimens by allele-specific oligonucleotide hybridization. The frequency of mutations detected was 30% and the most common mutation observed resulted in aspartic acid substitutions. Previous studies showed that specific Ki-ras mutations have been significantly associated with prognosis. Ki-ras codon 12 point mutational activation in CRC was significantly associated with the differentiation status of tumors in this study. Ethnic differences in the patterns of Ki-ras codon 12 point mutations were observed.

Goldberger's triad in dilated cardiomyopathy--can it predict the severity of left ventricular dysfunction?

Goldberger's triad is a specific, but relatively insensitive, electrocardiographic sign for dilated cardiomyopathy. To study the correlation between the presence of this sign and the severity of left ventricular dysfunction, the electrocardiograms and echocardiographically-determined left ventricular parameters of 17 patients (mean age 59.3 +/- 11.8 years) with dilated cardiomyopathy were examined. Five of the patients had Goldberger's triad. We found that the mean left atrial diameter, the mean left ventricular internal diameters (both end-systolic and end-diastolic) and the mean left ventricular ejection fraction of the group of patients with Goldberger's triad did not differ significantly from the group without. Coronary angiography revealed occult coronary artery disease in 5 of 12 patients. A larger, prospective study is required to verify our finding.

Midterm angiographic outcome of single-vessel intracoronary stent placement in diabetic versus nondiabetic patients: a matched comparative study

BACKGROUND

It remains controversial whether diabetes is associated with an increased risk of restenosis after intracoronary stenting.

METHODS AND RESULTS

We selected 42 diabetic patients and an equal number of nondiabetic patients with follow-up angiographic restudy after single-vessel stenting, matched for 4 important stent-related and angiographic variables (stent design, reference vessel size and expanded stent diameter, coronary vessel treated, and poststent residual diameter stenosis). The 2 patient groups did not differ in their baseline lesion severity and acute luminal gain. At 5-month angiographic assessment, the observed in-stent restenosis rate was significantly higher in diabetic than nondiabetic patients (40.5% vs 16.7%, P = 0.0157). It was highest in diabetic patients who received small stents <3.0 mm in diameter and intermediate in diabetic patients who received larger stent sizes (55% vs 27%, P = 0.0675). The frequency of restenosis in nondiabetic patients, however, was low; it was 18% and 15% in those who received small stents and larger stents, respectively (P = 0.7823).

CONCLUSIONS

Our data suggest that diabetes predisposes to an increased risk of in-stent restenosis, particularly in small vessels.

Laparoscopic management of Tenchkoff catheters in continuous ambulatory peritoneal dialysis. A one-port technique

We describe a one-port laparoscopic technique for assisting in Tenchkoff catheter placement and salvaging obstructed ones in patients requiring continuous ambulatory peritoneal dialysis (CAPD). This unique technique enables diagnostic laparoscopy, adhesiolysis, repositioning of catheters, and omentectomy to be performed without laparotomy. Six patients were treated. Only one 10-mm port was required, using an operating laparoscope and an instrument introduced through the working channel of the laparoscope. Adhesiolysis was performed under laparoscopic vision; omentectomy and flushing of blocked catheters were carried out extracorporeally. The catheters were then repositioned to the pelvic cavity under laparoscopic vision. All patients were followed up for 6-10 months. No mechanical problem was noticed. Our one-port laparoscopic technique is a simple and effective method for treating patients who have mechanical problems with their peritoneal dialysis catheters.

Early experience with the NIR intracoronary stent

Immediate and midterm results of 61 NIR stent placement attempts in 55 native coronary vessels in 52 patients demonstrate a high clinical success rate of 98%, no early stent thrombosis, and a 5-month angiographic restenosis rate of 23%. The frequency of in-stent restenosis was significantly heightened in small vessel sizes and in diabetic patients.

Long-term (36-63 month) clinical and echocardiographic follow-up after Inoue balloon mitral commissurotomy

Although Inoue balloon mitral commissurotomy (BMC) offers excellent short-term results, there remains a paucity of data on its long-term (> or =3 yr) outcome. We therefore analyzed the outcome of 68 consecutive patients who had regular long-term clinical and serial echocardiographic follow-up of > or =3 yr after successful BMC. The procedure provided significant improvements in transmitral valve gradient (13+/-6 mmHg before to 5+/-2 mmHg after BMC, P = 0.0001), left atrial pressure (21+/-6 mmHg before to 14+/-5 mmHg after BMC, P = 0.0001), and mitral valve area (0.8+/-0.2 cm2 before to 1.7+/-0.4 cm2 after BMC, P = 0.0001) without incurring > grade 2+ angiographic mitral regurgitation. At a mean follow-up of 44+/-9 mos (range, 36-63 mo), functional benefits were maintained in 91% of patients. Serial echocardiographic evaluations performed in 97% of patients revealed a restenosis rate of 15% (defined as a loss of >50% initial gain in valve area or a valve area of <1.5 cm2). No strokes or deaths were encountered. Of the 15 clinical, echocardiographic, and procedural variables analyzed in a multivariate model, only the presence of chronic atrial fibrillation was an independent correlate of restenosis (P < 0.05). It was clearly more common in patients with than those without restenosis (100% with vs. 57%, respectively, P = 0.009). In conclusion, our study shows that BMC confers maintained long-term functional benefits and a low anatomic restenosis rate 23 yr after BMC.

Anomalous origin of left main coronary artery from the noncoronary sinus: an intravascular ultrasound observation

We report on a rare case of anomalous origin of left coronary artery from the noncoronary sinus of Valsalva. Intraaortic intravascular ultrasound study identified the origin of the left coronary artery and facilitated subsequent selective coronary angiography of the artery.

p53 mutations detected in colorectal carcinoma patients in Hong Kong

A mutational spectrum for exons 5-8 of the p53 tumor suppressor gene in colorectal carcinomas in Hong Kong Chinese was established. Ninety-nine colorectal carcinomas from Hong Kong patients were analyzed for mutations in p53 gene by PCR-single-strand conformation polymorphism analysis and direct DNA sequencing. Thirty-five of the 99 tumors (35.4%) contained mutations. Point mutations accounted for 80% of all genetic changes and were predominantly base transitions at CpG dinucleotide sites, mutations that were also predominant in Caucasian carcinomas. The major hot spots at codons 175 and 248 of p53 in Caucasians are also hot spots in the Chinese gene. Identical mutations in codons 152 and 306 were detected in two independent tumors in the Chinese, which were reported only rarely in Caucasians. Moreover, a significantly higher frequency (20%) of deletion and insertion mutations was observed in Hong Kong colorectal cancer patients. Distinct genetic and/or environmental factors may contribute to these findings.

p16 tumor suppressor gene mutations in Chinese esophageal carcinomas in Hong Kong

The frequency and nature of genetic alterations in the p16 tumor suppressor gene in 25 esophageal squamous cell carcinoma specimens from Chinese patients were investigated by PCR-SSCP and DNA sequencing techniques. No gross deletions occurred in either exon 1 and 2 of the gene by PCR amplification. However, genetic changes were observed in three cases. These included a point mutation in codon 12 of exon 1 with a resulting Ala --> Thr amino acid substitution, a point mutation at base 91 in the non-coding region of exon 1, and a 1 base pair insertion in codon 116 of exon 2. The low mutation frequency of 12% is consistent with that of three previous studies involving Japanese and Caucasian patients (8, 16 and 21% frequency: Esteve et al., 1996, Igaki et al., 1995 and Zhou et al., 1994). p16 gene mutations do not appear to play a major role in esophageal carcinogenesis.

One-stage thoracoscopic oesophagectomy: ligature intrathoracic stapled anastomosis

Thoracoscopic oesophagectomy is usually performed in stages and intrathoracic oesophagogastric anastomosis often requires mini-thoracotomy or extension of the thoracoscopic incisions. This paper describes a new technique whereby such an operation could be completed in one stage and the need to extend the thoracoscopic incisions is obviated.

Transradial coronary angiography and angioplasty in Chinese patients

Radial artery punctures for diagnostic coronary angiography or coronary balloon angioplasty were performed in 211 patients with a success rate of 98% (207 patients). In the four failed transradial accesses, the procedure was accomplished via the transfemoral route. Major local vascular complications included one arteriovenous fistula, one pseudo-aneurysm, and one ischemic contracture of the right hand. Reduced radial pulses were noted in 25 (12%) patients at follow-up without ischemic manifestations. Transradial diagnostic coronary angiography was successfully completed in 184 (98%) of 187 patients. The technical success for balloon angioplasty was obtained in 73 (97%) of 75 patients. Clinical success was observed in 68 (91%) patients; balloon angioplasty resulted in one nonfatal myocardial infarction and four late deaths (3 cardiac and 1 stroke). We believe that transradial catheterization for diagnostic coronary angiography and balloon angioplasty in our relatively small built Chinese population is a safe and practical alternative approach.

The role of intracoronary stents in the prevention of restenosis--facts and fallacies

Ten years after the first stents were implanted in human coronary arteries by Dr Sigwart, stenting has proved itself to be a highly effective solution to acute or threatened closure associated with failed balloon angioplasty, and in the prevention of restenosis. Despite these salutary and exciting outcomes, there remain a number of issues of deep-seated concern including stent thrombosis and anticoagulation-related bleeding complications. Recently, these two latter problems have been largely rectified by evolving technical refinements in stent implantation and the use of less aggressive post-stent antithrombotic regimens. The technology, however, has also created a new, potentially complex situation-that of stent overuse and the implantation of stents for non evidence-based indications.

Coronary arteriography in the presence of dextrocardia and situs inversus

Given the rarity of dextrocardia, it is not unexpected that there are only a few reports of coronary arteriography in such a setting. We describe a case of successful coronary arteriography in a patient with mirror image dextrocardia and situs inversus, and the technique used, and review the literature.

Percutaneous balloon mitral valvuloplasty in patients with mitral restenosis after previous surgical commissurotomy. A matched comparative study

BACKGROUND

Although the efficacy of percutaneous balloon mitral valvuloplasty in patients with unoperated mitral stenosis has been well documented, there exists less clear-cut data on its effectiveness in patients with mitral restenosis after previous surgical commissurotomy. Accordingly, the purpose of this study was to evaluate our immediate and midterm results of balloon mitral valvuloplasty in this subset of patients with previous mitral surgery.

METHODS

Between October 1991 and August 1995, 29 consecutive patients with mitral restenosis after prior surgical commissurotomy (group 1) underwent Inoue balloon mitral valvuloplasty. They were matched on a patient-to-patient basis with regard to baseline mitral echocardiographic score mitral valve area, severity of angiographic mitral regurgitation and follow-up duration with 29 other patients with unoperated mitral stenosis (group 2) who underwent balloon mitral valvuloplasty during the same study period.

RESULTS

Balloon mitral valvuloplasty yielded identical improvements in transmitral gradient and mitral valve area (from 0.8 to 1.6 cm2) determined echocardiographically, and similar changes in the severity of mitral regurgitation in both groups of patients. All procedures were successfully completed without major cardiac complications. Follow-up echocardiographic assessment in 73% of patients revealed equal mitral valve area (1.6 cm2) and a restenosis rate of 17%, with no difference in the restenosis rate between the two groups.

CONCLUSION

Balloon mitral valvuloplasty in selected patients with mitral restenosis after past surgical commissurotomy can be performed safely and with similar immediate and midterm efficacy as in patients with de novo mitral stenosis.

Laparoscopic cholecystectomy: two-port technique

BACKGROUND AND STUDY AIMS

Conventional laparoscopic cholecystectomy requires four ports. The present study describes a new laparoscopic cholecystectomy technique using two ports only.

PATIENTS AND METHODS

Sixty-two consecutive patients with symptomatic gallstones underwent laparoscopic cholecystectomy using this two-port technique. The operation requires a straightforward laparoscope and a percutaneous sling to retract the gallbladder laterally and cephalad.

RESULTS

The two-port method was successful in 52 patients; eight required an additional port, and two required conversion to open surgery. Our results showed that the operating time and complication rate were comparable to those in other series using the conventional laparoscopic method.

CONCLUSION

The two-port method is technically more demanding, and should only be used to remove simple, uncomplicated gallbladders. The surgeon should always be prepared to insert more trocars or convert to open procedures when necessary.

Safety and efficacy of percutaneous Inoue-balloon mitral commissurotomy

BACKGROUND

Although percutaneous transvenous mitral commissurotomy (PTMC) is currently accepted as the first-line treatment modality for selected patients with mitral stenosis, technical failures and the potential risk of inadvertent cardiac perforation with tamponade, resultant severe mitral regurgitation and death associated with the procedure continue to be important issues of concern.

OBJECTIVES

The purpose of this study was to assess the safety profile and acute results of Inoue-balloon PTMC in a consecutive series of 50 patients with symptomatic significant mitral stenosis who underwent the procedure between January 1993 and August 1994.

RESULTS

PTMC was successfully completed in all patients without encountering cardiac perforation, cardioembolism, severe (> or = grade 3+) angiographic mitral regurgitation or death. The mitral valve area increased from 0.8 +/- 0.2 cm2 to 1.7 +/- 0.4 cm2 (p = 0.0001) as assessed echocardiographically. Optimal results defined as a valve area improvement of > or = 50% and/or a final valve area of > or = 1.5 cm2 without significant mitral regurgitation (> or = 2 grade increase in mitral regurgitation or a final regurgitation > or = 3+) was obtained in 94% of patients.

CONCLUSION

We confirm that Inoue-balloon PTMC is a safe and highly effective procedure as reflected by the absence of cardiac perforation, cardioembolism, severe mitral regurgitation or death and the excellent enlargement in mitral valve area. Furthermore, in our study the clinical restenosis rate was low with the majority of patients maintaining their improved functional status over a 14-month follow-up period.

Immediate and long-term results of percutaneous Inoue balloon mitral commissurotomy with use of a simple height-derived balloon sizing method for the stepwise dilation technique

OBJECTIVE

To assess the short- and long-term efficacy of Inoue balloon percutaneous transvenous mitral commissurotomy (PTMC) with use of our simple balloon sizing method based on patient height.

DESIGN

Data from 105 consecutive patients with symptomatic mitral stenosis who underwent 107 PTMC procedures between October 1991 and April 1995 at our hospital were analyzed.

RESULTS

All PTMC procedures were successfully completed with no instances of cardiac perforation, systemic embolism, severe mitral regurgitation (grade 3 or more angiographically), or death. The mean mitral valve area increased from 0.8 +/- 0.2 cm2 to 1.7 +/- 0.4 cm2 (P = 0.0001), as assessed echocardiographically. Optimal results -- defined as an improvement in valve area of 50% or more or a final valve area of 1.5 cm2 or more without significant mitral regurgitation (an increase in mitral regurgitation of two or more grades or a final regurgitation of grade 3 or more) -- were obtained in 96% of patients. At a mean follow-up interval of 20 months, symptomatic benefit was maintained in 97% of patients. Echocardiographic evidence of restenosis (loss of more than 50% initial gain in valve area, a valve area of less than 1.5 cm2, or both) was noted in 9.8%.

CONCLUSION

Inoue balloon PTMC with use of our simple balloon sizing method yielded excellent short- and long-term results in terms of mitral valve enlargement and sustained symptomatic benefit without the creation of severe mitral regurgitation.