Initial clinical experience with heart transplantation

Clinical experience with cardiac transplantation in 2 patients with terminal heart disease is described. The first patient suffered chronic and progressive heart failure due to postviral myocardial fibrosis and coronary artery disease. Following successful operation multiple complications occurred, and the patient died on the fifteenth postoperative day of gastrointestinal bleeding and gram negative sepsis. Histologic evidence of mild rejection was present at postmortem examination. The second patient presented with terminal ischemic heart disease complicated by severe pulmonary hypertension. Postoperatively severe and unremitting arterial hypoxemia caused death on the third postoperative day. Postmortem examination failed to show evidence of rejection but revealed advanced obliterative changes in the pulmonary vasculature.

Despite the disappointing outcome of these 2 cases, cardiac transplantation in man deserves extensive clinical trial. The methods of clinical study and eventual objectives are outlined.     

三腔起搏技术的初步临床应用

心脏起搏技术发展迅速,三腔起搏技术为防治某些心律失常提供了一个有效的治疗手段。我院于1998年12月23日用该技术为一例患者植入永久人工心脏起搏器进行治疗,近期疗效良好,现报告如下。 资料和方法     

Initial clinical experience with implantable loop recorders.

The purpose of this study was to review the initial experience of a university hospital with Implantable Loop Recorders (ILR) for diagnosis of recurrent unexplained syncope or presyncope. Twelve patients with syncope or presyncope of unknown etiology (who had a negative tilt table test, electrophysiologic study, and neurologic work-up) underwent implantation of ILR. All implants were performed using the Reveal ILR (Medtronic AVE, Santa Rosa, California). The 8 cc device is 61 mm long, 19 mm wide, 8 mm thick and weighs 17 grams. It has 18 months of battery life and has 2 electrodes with 38.5 mm spacing. The device is nonvascular and is implanted approximately 2 fingerbreadths below the clavicle in a subcutaneous pocket (1.5 inches long) and is secured via polydacron suture to the pre-pectoral fascia/pectoralis muscle. Twelve patients with a mean age of 61 +/- 22 years received the ILR. Ten patients had syncope and 2 had presyncope. Three patients had coronary artery disease and 2 had dilated cardiomyopathy. ILRs were implanted for a mean follow-up period of 7.2 +/- 5.8 months (range, 1 day to 18 months). Two patients still continue to be monitored at the time of this report. The mean number of events prior to ILR was 6.0 +/- 5.4. Eight patients (66%) had recurrent syncope after implantation. One patient was not available for follow-up. There were no significant complications from the implant. In 5/12 patients (42%), the ILR helped to diagnose the etiology of the syncopal episode. Syncope was secondary to asystole in three patients, junctional bradycardia in another patient, and seizure activity in a fifth patient (high-frequency noise recorded on the electrocardiogram during sinus rhythm). The 4 patients with ILR-documented bradyarrhythmias underwent permanent pacemaker implantation and are alive and well. ILR implantation is a simple, useful and safe method in assisting with the diagnosis of recurrent unexplained syncope or presyncope after an inconclusive electrophysiologic and neurologic evaluation.     

Rotational atherectomy with a new device: Initial clinical experience

The Bard Atherectomy Catheter is a new rotational atherectomy device that consists of a flexible, hollow, thin-walled cutting catheter that, while rotated at 1,500 revolutions per minute, is advanced across the lesion over a special spiral guidewire system. We report the initial clinical experience with this device in 20 peripheral lesions in ten patients. The majority of patients were treated for limb salvage. All lesions were successfully intervened on by atherectomy followed by adjunctive balloon angioplasty. A reduction to less than 50% stenosis was achieved in 13 of the 20 lesions (65%) after atherectomy but in all 20 lesions (100%) after adjunctive angioplasty for all lesions and stenting for dissections in two. Baseline minimal lesion lumen diameter was 0.8 ± 0.7 mm with a reference vessel diameter of 4.2 ± 1.7 mm (75 ± 21% stenosis). The lumen improved to 2.0 ± 0.8 mm (45 ± 19% stenosis) (P < 0.001) following atherectomy and to 3.9 ± 1.9 mm (13 ± 16% stenosis) (P < 0.001) after adjunctive angioplasty. The average weight of removed atheroma was 45 ± 58 mg. All ten patients had initial improvement in symptoms. At 6 months follow-up there was persistent improvement in eight patients and two subjects had undergone amputations. Our early clinical experience with this low profile, flexible atherectomy device, that enables extraction of a large amount of atheroma, suggests that it will become a valuable addition to current atherectomy technologies in small- and medium-sized vessels. The value of this device in coronary vessels is under investigation. © 1996 Wiley-Liss, Inc.     

Initial clinical experience with the HeartMate II axial-flow left ventricular assist device

The redesigned HeartMate II, an axial-flow left ventricular assist device, is simpler, smaller, and easier to operate than are pulsatile pumps. These design characteristics should make the HeartMate II more reliable and durable and broaden the eligible population base. We implanted the HeartMate II in 43 patients (average age, 42 yr). The indication for use was bridge-to-heart transplantation in 26 patients and destination therapy in 17. The average duration of device support was 258 days (range, 1-761 days), and cumulative duration, more than 31 patient-years. Hemodynamic function improved in all patients during support. By 48 hours after implantation, the mean cardiac index had increased from 1.9+/-0.27 L/(min.m(2)) (baseline) to 3.5+/-0.8 L/(min.m(2)), and the pulmonary capillary wedge pressure had decreased from 24.8+/-11 mmHg to 18.5+/-5.3 mmHg. Of the 43 patients, 35 were discharged from the hospital. Support is ongoing in 27 patients (longest duration, >700 days). Nine patients died during support. Four patients had sufficient heart recovery to undergo pump explantation. Three patients underwent transplantation. One patient underwent device replacement after the pump driveline was fractured in a skateboarding accident; the device was removed in another patient because of a pump-pocket infection after 749 days of support. Of the 10 patients in whom the HeartMate II replaced a failed HeartMate I, 8 were discharged from the hospital. We have seen excellent results with use of the HeartMate II. Functional status and quality of life have greatly improved in patients who survived the perioperative period.     

Initial clinical experience with a biofragmentable ring for sutureless bowel anastomosis

Twenty-seven patients have had bowel anastomoses with a biofragmentable ring for sutureless bowel anastomosis. There were no complications associated with the anastomotic techique. One patient developed an ischemic stricture of the proximal side of the anastomosis due to compromised circulation. There was no leakage. Technical factors regarding the BAR anastomosis are described. A properly placed purse-string suture is of primary importance. Advantages appear to be a more rapid and easy anastomosis with better healing.     

Initial clinical experience with the Jarvik 2000 implantable axial-flow left ventricular assist system

BACKGROUND: Implantable left ventricular assist systems (LVASs) are used for bridging to transplantation, bridging to myocardial improvement, and for permanent circulatory support. Conventional implantable systems have inherent limitations that increase morbidity during support. In contrast, small, efficient, axial-flow pumps, which have been under development for the past decade, have the potential to improve the length and quality of life in patients with severe heart failure. Methods and Results- To assess the safety and clinical utility of the Jarvik 2000, we implanted this device in 10 transplant candidates (mean age 51.3 years) in New York Heart Association (NYHA) class IV. Implantation was achieved through a left thoracotomy during partial cardiopulmonary bypass. The mean support period was 84 days. Within 48 hours postoperatively, the cardiac index increased 43%, pulmonary capillary wedge pressure decreased 52%, systemic vascular resistance decreased significantly, and inotropic support became unnecessary. Eight patients underwent physical rehabilitation and returned to NYHA class I. Their left ventricular dimensions, cardiothoracic ratios, and pressure-volume loop analyses showed good left ventricular unloading. Seven patients underwent transplantation and 3 died during support. No device thrombosis was observed at explantation. CONCLUSIONS: The Jarvik 2000 functions as a true assist device by partially unloading the left ventricle, thereby optimizing the patient's hemodynamics. Our preliminary results indicate that this LVAS may safely provide circulatory assistance for heart transplant candidates.     

Initial clinical experience with a novel flexible endoscopic robot for transanal surgery

Techniques in Coloproctology - The Flex® Robotic System (Medrobotics, Raynham, MA, USA) is the first miniaturised flexible endoscopic robot that aims to allow surgical manoeuvres beyond the...     

Initial clinical experience with cardiac resynchronization therapy utilizing a magnetic navigation system

Introduction: The placement of left ventricular (LV) leads during cardiac resynchronization therapy (CRT) involves many technical difficulties. These difficulties increase procedural times and decrease procedural success rates. Methods and Results: A total of 50 patients with severe cardiomyopathy (mean LV ejection fraction was 21 ± 6%) and a wide QRS underwent CRT implantation. Magnetic navigation (Stereotaxis, Inc.) was used to position a magnet‐tipped 0.014″ guidewire (Cronus? guidewire) within the coronary sinus (CS) vasculature. LV leads were placed in a lateral CS branch, either using a standard CS delivery sheath or using a “bare‐wire” approach without a CS delivery sheath. The mean total procedure time was 98.1 ± 29.1 minutes with a mean fluoroscopy time of 22.7 ± 15.1 minutes. The mean LV lead positioning time was 10.4 ± 7.6 minutes. The use of a delivery sheath was associated with longer procedure times 98 ± 32 minutes vs 80 ± 18 minutes (P = 0.029), fluoroscopy times 23 ± 15 minutes vs 13 ± 4 minutes (P = 0.0007) and LV lead positioning times 10 ± 6 minutes vs 4 ± 2 minutes (P = 0.015) when compared to a “bare‐wire” approach. When compared with 52 nonmagnetic‐assisted control CRT cases, magnetic navigation reduced total LV lead positioning times (10.4 ± 7.6 minutes vs 18.6 ± 18.9 minutes; P = 0.005). If more than one CS branch vessel was tested, magnetic navigation was associated with significantly shorter times for LV lead placement (16.2 ± 7.7 minutes vs 36.4 ± 23.4 minutes; P = 0.004). Conclusions: Magnetic navigation is a safe, feasible, and efficient tool for lateral LV lead placement during CRT. Magnetic navigation during CRT allows for control of the tip direction of the Cronus? 0.014″ guidewire using either a standard CS delivery sheath or “bare‐wire” approach. Although there are some important limitations to the 0.014″ Cronus? magnetic navigation can decrease LV lead placement times compared with nonmagnetic‐assisted control CRT cases, particularly if multiple CS branches are to be tested.     

Initial clinical experience with a miniature biplane transesophageal echocardiographic probe in adults

Transesophageal echocardiography (TEE) is now routinely used in cardiovascular medicine. With improved technology the size of TEE probes has increased. Recently there has been interest in using smaller probes for adult TEE. We used a miniature 32-element, phased array biplane probe in 20 consecutive adults who underwent clinically indicated TEE evaluation. The miniature biplane probe was easily inserted without complication in all patients including one with thrombocytopenia and one with an esophageal stricture. Subjectively the probe was easier to insert and better tolerated by patients than standard adult TEE probes. High quality images of near-, mid-, and far-field structures were obtained in a majority of patients. Color Doppler identified mitral regurgitation in 12 (60%) patients, tricuspid regurgitation in ten (50%) patients, and aortic insufficiency in five (25%) patients. The miniature biplane TEE probe used in this study enhanced patient comfort without significant loss of image quality.     

Initial experience with paclitaxel-coated stents

Local delivery of immunosuppressive or antiproliferative agents using a drug-eluting stent is a new technology that is supposed to inhibit in-stent restenosis, thus providing a biological and mechanical solution. This technique is a very promising. To date, several agents have been used, including paclitaxel, QP-2, rapamycin, actinomycin D, dexamethason, tacrolimus, and everolimus. Several studies, published recently or still ongoing, have evaluated these drugs as to their release kinetics, effective dosage, safety in clinical practice, and benefit. These studies include: SCORE (paclitaxel derivative), TAXUS I-VI, ELUTES, ASPECT, DELIVER (paclitaxel), RAVEL, SIRIUS (sirolimus), ACTION (actinomycin), EVIDENT, PRESENT (tacrolimus), EMPEROR (dexamethason), and FUTURE (everolimus). Paclitaxel was one of the first stent-based antiproliferative agents under clinical investigation that provided profound inhibition of neointimal thickening depending on delivery duration and drug dosage. The randomized, multicenter SCORE trail (Quanam stent, paclitaxel-coated) enrolled 266 patients at 17 sites. At 6-month's follow-up, a drop of 83% in stent restenosis using the drug-eluting stent could be achieved (6.4% drug-eluting stent vs 36.9% control group), which was attributable to a remarkable decrease in intimal proliferation. Unfortunately, due to frequent stent thrombosis and side-branch occlusions, the reported 30-day MACE rate was 10.2%. The randomized TAXUS-I safety trial (BSC, NIRx, paclitaxel-coated) also demonstrated beneficial reduction of restenotic lesions at 6-month's follow-up (0% vs 10%) but was associated with the absence of thrombotic events presumably due to less drug dosage. The ongoing TAXUS II-VI trials are addressing additional insight regarding the efficacy of the TAXUS paclitaxel-eluting stent. ASPECT and ELUTES evaluated paclitaxel-coated stents (i.e., Cook and Supra G), including subgroups with different drug dosages. With respect to stent restenosis and neointimal proliferation, both studies demonstrated a clear dose response. The RAVEL and the SIRIUS trials evaluated sirolimus-coated stents (i.e., Cordis, Johnson & Johnson, and Bx VELOCITY stents). Results confirmed the beneficial findings regarding reduction of renarrowing using a drug-eluting stent without any major adverse effects. Although parameters such as drug toxicity, optimal drug dosage, or delayed endothelial healing still need to be evaluated, today's clinical experience indicates that drug-coated stents are extremely beneficial in the interventional treatment of coronary lesions.     

Initial experience with laparoscopic appendectomy

As experience with laparoscopy increases, new applications in general surgery are being identified. Treatment of acute appendicitis through the laparoscope has been proposed. We present our initial experience with this new technique. Over a 12-month period, laparoscopic appendectomy was attempted in 29 patients. There were no intraoperative complications. Two cases required conversion to the open technique owing to gangrene at the appendiceal base. The average operating time was 64 minutes. Two of nine patients with perforated appendicitis developed a pelvic abscess, and one patient developed wound cellulitis. Pain medication requirements were minimal, bowel function returned rapidly, and half of the patients were discharged on postoperative day one or two and returned to normal activity within one week. Based on our initial experience, it appears that laparoscopic appendectomy is a safe and effective technique for managing acute appendicitis and offers advantages in terms of decreased pain, decreased hospital stay, and a rapid return to normal activities     

Initial experience with the Toronto Root bioprosthesis

BACKGROUND AND AIM OF THE STUDY: The study aim was to assess the safety and efficacy of the Toronto Root bioprosthesis for aortic root or valve replacement during the early postoperative stages. METHODS: Between November 2000 and December 2002, the Toronto Root was implanted in 191 patients in 17 institutions. The patients' mean age was 65 years (range: 25 to 87 years) and 70% were males. The bioprosthesis was implanted as a full aortic root in 76% of patients, as a root inclusion in 9%, and in the subcoronary position in 15%. The sizes used in decreasing frequency were 27, 29, 25, 23 and 21 mm. Coronary artery bypass was performed in 25% of patients. Echocardiography was performed before hospital discharge and at six months postoperatively. Serum aluminum levels were monitored pre- and postoperatively as this metal is used in anticalcification treatment of the arterial wall of the porcine root. For the purpose of this study, follow up was closed at six months in all patients, and was complete. RESULTS: Eight patients died, though none of the deaths was valve-related. Two patients required reoperation because of technical errors during implantation. Two patients developed endocarditis, one patient required surgical intervention, and two patients suffered cerebral transient ischemic attacks. All survivors experienced symptomatic improvement, and 97% were in NYHA functional classes I and II at six months postoperatively. Blood levels of aluminum were unchanged at follow up. The mean effective orifice area of all valves studied was 2.0 +/- 0.8 cm2, and the mean systolic gradient 7.0 +/- 3.9 mmHg at six months postoperatively. No patient had more than trace aortic insufficiency. CONCLUSION: Early experience with the Toronto Root bioprosthesis has shown it to be a safe and effective valve for aortic valve or aortic root replacement, with excellent hemodynamic characteristics, a low transvalvular gradient and a large effective orifice area.     

网篮电极导管临床使用的初步经验

目的：评价64极网篮电极导管在电生理检查及射频消融中的实用价值。方法：4例患者,根据发作时心电图诊断为房性心动过速（房速）3例,左心室室性心动过速1例,网篮电极导管分别经右侧股静脉或股动脉送入右心房或左心室,选择记录双极心电信号,对每1例患者均进行窦性心律及心动过速时的标测,并在网篮电极导管指引下进行消融,结果：4例患者网篮电极导管均顺利送入,术中及术后无明显并发症发生,通过网篮电极所记录心电信号清晰,稳定,根据计算机所绘制等时标测图及网篮在心腔内的影像位置,可准确地判断除极波传播顺序,方向及最早激动点,确定心律失常的起源部位及发生机制,2例房速及1例室性心动过速患者消融成功,另1例房速患者消融失败。结论：利用网篮电极导管进行心内膜高密度标测,有助于提高心脏电生理检查及射频消融手术的效率。     

Initial clinical experience with a 48 by 48 element biplane transesophageal probe.

Recent technologic advances in ultrasound have resulted in the capability of transesophageal echocardiographic imaging in both transverse and longitudinal planes. Previous biplane probes suffered from inferior images because of reduced scan elements. We evaluated the utility of a prototype 48 X 48 element biplane transesophageal probe in 23 consecutive patients. Examinations were well tolerated with no side effects. In comparison to the single transverse plane, imaging with the longitudinal plane gave superior information on prosthetic valve pathology, atrial septal abnormalities, and pathoanatomy of the ascending aorta and mitral valve. Complementary information was provided by the longitudinal plane in patients with endocarditis and vegetations and in mitral protheses. Images obtained with this 48 X 48 element biplane probe along with color and spectral Doppler information were not perceptibly inferior to those obtained by single-plane probes. In conclusion, biplane transesophageal echocardiography with a 48 X 48 element probe indicates a great potential for enhanced three-dimensional understanding of cardiac pathology and diagnostic yield in specific pathologies.     

Initial clinical experience with extracorporeal shock wave therapy in treatment of ischemic heart failure

Previous experimental studies have suggested a beneficial effect of extracorporeal shock wave therapy (ESWT) in patients with ischemic heart failure. Twenty-four patients with ischemic heart failure and left ventricular ejection fraction (LVEF) <40% received ESWT in addition to their stable treatment. ESWT was performed in 9 sessions with 100 shocks per spot in viable segments detected by dobutamine stress echocardiography. Patients were evaluated at baseline and at 3 and 6 months after ESWT. Tc-99m MIBI single photon emission computed tomography was performed on inclusion and at 6 months. ESWT significantly decreased New York Heart Association class from 2.2±0.8 to 1.7±0.7 at 3 months (P<.01) and 6 months after ESWT (1.7±0.7). Six-minute walk test improved from 414±141 to 509±141 and 538±116 (P<.01) at 3 and 6 months, respectively. A steady decrease of Canadian Cardiovascular Society angina class from 2.6±0.7 to 2.1±0.8 and 1.9±0.7 (P<.01) at 3 and 6 months, respectively, was observed. A significant increase in LVEF at rest at 3 and 6 months after ESWT (from 32.2±6.0 to 34.8±9.6 and 37.7±9.5, P=.03, respectively) was noted. Summed rest score (from 23.9±8.1 to 21.4±7.1, P=.03) and stress score improvement (from 28.2±8.4 to 24.6±6.4, P=.04) by single photon emission computed tomography was registered. Significant clinical improvement accompanied by beneficial changes of LVEF and rest/stress perfusion was found after ESWT.