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A case of pacemaker electrode infection with Staphylococcus aureus is presented. In order to avoid sternotomy, the right ventricular pacemaker lead, which had been implanted for 15 years, was successfully extracted using a laser sheath despite large endocarditic vegetations on the pacemaker lead. After completion of a 6-week course of antibiotics, the patient was discharged without any further evidence of infection.

The efficacy of RF energy versus the neodymium:yittrium aluminum-garnet laser to create linear lesions was compared in fresh ex vivo swine hearts. A total of 598 lesions were created in four locations: ostium of the pulmonary veins, trabeculated lateral left atrium, smooth posterior part of the right atrium, and the isthmus between the inferior vena cava and tricuspid valve. A 400-micron bare quartz fiber with CO2 cooling (distance to the tissue 5, 10, and 15 mm) and an RF ablation catheter (4-mm tip) were mechanically dragged over the tissue at speeds 0.5, 1.0, and 1.5 mm/s. A continuous and transmural ablation line was recorded as successful. A 100% success rate was achieved at the pulmonary veins and the isthmus at some settings of energy delivery by the laser and RF. In the thick posterior right atrium, RF resulted in transmural lesions only when associated with carbonization, while the laser produced successful ablation lines in 100% of the attempts. In the left atrium, because of the presence of prominent trabeculations, RF was unsuccessful at all settings of energy delivery. In contrast, deep photocoagulation by laser resulted in successful ablations in the left atrium in 100% of attempts. Lesion formation was faster by laser ablation and mean lesion width was at least 25% smaller with the laser than with RF. In conclusion, the formation of linear lesions at the isthmus and at the pulmonary veins was successful with the laser and RF. In the trabeculated left atrium and the thick posterior right atrium, only laser ablation was successful.

Endstage coronary artery disease still remains a therapeutic challenge. An increasing number of patients is no longer amenable for direct revascularization by PTCA or coronary bypass surgery and does also no longer respond to maximum medical therapy. This fact has directed the interest again towards surgical techniques of indirect revascularization, which had been introduced by Beck and other surgeons more than 60 years ago. Among these attempts we can also find transmyocardial needle punctures, firstly performed by Sen in Bombay. In the early eighties it was Mirhoseini, who used a laser for creating these transmural channels, primarily in combination with coronary bypass surgery at the arrested heart and later on together with Crew as a sole therapy at the beating heart. The idea behind this transmyocardial laser revascularization (TMLR) was a "reptilization" of the human heart, which meant a direct blood supply from the ventricle into the ischemic myocardium. Whereas this theory has not proven to be true, as the surface area of these channels is not sufficient for the nutrition of the surrounding myocardial tissue by diffusion or convection, different models have been developed by anatomical, experimental and clinical studies, such as the connection between the laser channels and intramyocardial vessels or capillaries, analogous to ventriculo-coronary connections in human anatomy or pathology as for example those connections described in children with pulmonary atresia and intact ventricular septum or the Thebesian veins. Moreover the laser trauma may also simply contribute to the induction of neoangiogenesis. While the function of TMLR is still not clearly defined, clinical studies in the United States and also in other countries have proven the clinical efficacy in a cohort of severely diseased patients undergoing this procedure. Accordingly more than 2/3 of all patients after TMLR showed a significant improvement of more than 2 angina classes (CCS) as well as a decrease in medication and hospitalization. Moreover there was also a reduction of ischemic areas demonstrated by szintigraphy and, in one study from Houston, also by positron emission tomography. While the overall mortality in all those studies is still considerably high, a reduction could be achieved by a stricter selection of patients excluding especially those with a severely impaired left ventricular function. As demonstrated by preliminary data from the last phase III FDA-study, TMLR may even reduce long-term mortality compared to maximum medical therapy in a randomized group of patients. Our own experiences in 134 patients also confirmed a significant reduction of angina after TMLR alone (n = 67) or in combination with bypass surgery (n = 67) with the majority of patients being in angina class 1 and 2 (CCS) 6 months after surgery. All of these patients were in angina class 3 and 4 before surgery. Nuclear scans could demonstrate an improved perfusion in more than 40%. Further studies as well as other clinical and also experimental investigations have still to be awaited, before the definitive role of TMLR within the armamentarium against coronary artery disease can be determined. However, it is already a therapeutic option for those highly symptomatic patients, who cannot be offered a different treatment modality.

Transmyocardial laser revascularization (TMLR) is a new technique for patients with CAD or heart attack to revascularize ischemic areas of the myocardium in which the localisation or the condition of the vessels does not allow bypass grafting. This study shows the results in observation of patients before and during the first 3 months after TMLR. Of 110 patients operated on from 1994 to 1996, 86 were evaluated for well being (quality of life), using NYHA- and CCS-classification, stress test and nitril-scintigraphy at rest and under stress conditions. 51 patients, of whom 11 were females, underwent TMLR combined with coronary artery bypass graft (CABG). 35 male patients were treated singularly with TMLR. The average age in both groups was 59 years (+/- 23). All patients were subject to phase I rehabilitation in specialised institutions after being mobilised in the operating hospital. The evaluations took place on the day of admission to the hospital prior to surgery, within 10 days after surgery and 3 months following. The average stay in the rehabilitation-institution was between 4 and 6 weeks. Our findings demonstrate that both groups profited from the procedures, while the TMLR/CABG group showed a faster recovery and a better outcome. In comparison to 57% of the TMLR group, 85% of the patients in the TMLR/CABG group reported an improvement ranging from good to significant in quality of life assessments. The TMLR/CABG rated from an average of initially 3.4 (+/- 0.6) to 2.1 (+/- 0.8) after 3 months at NYHA- and 3.3 (+/- 0.7) to 1.7 (+/- 0.8) at CCS-classification. The TMLR group rated from 3.6 (+/- 0.5) to 2.4 (+/- 0.8) in NHYA- and from 3.4 (+/- 0.5) to 1.9 (+/- 0.7) on the CSS-scales. A remarkable improvement was noted in the stress test with an increase in power and endurance from 21 to 89 watts for the combined group and 8 to 81 watts for the TMLR treated patients, who generally recovered more slowly. The perfusion scan showed the same tendencies as previously reported but in some cases the results were not congruent with other findings. Overall, our findings indicate that there is a benefit for terminally symptomatic CAD patients after TMLR, but an observation period of 3 months does not allow for final conclusions on this matter. Rehabilitation seems to be of value for TMLR-patients since they have shown a markedly better performance following 3-month treatment, but further data from clinical randomised trials are needed to determine the influence of TMLR with short- and long-term rehabilitation on the prognosis of the disease.

There is a subgroup of patients with coronary artery disease who are refractory to the therapeutical methods so far applied. We report on 128 patients who fulfill this definition and have therefore undergone pure transmyocardial laser revascularisation (TMLR) or transmyocardial laser revascularisation in combination with coronary bypass surgery at our institution. The patients can be characterized by a long history of coronary artery disease with multiple revascularizing procedures, e.g. bypass surgery or percutaneous transluminal coronary angioplasty (PTCA), pronounced symptoms of coronary artery disease and chronic heart failure in the presence of markedly reduced left ventricular ejection fractions and intense antiischemic medical therapy. The patients were 62.2 +/- 9.8 (SD) years of age, in 89.9% of them at least one bypass operation and in 44.5% up to more than three percutaneous transluminal coronary angioplasties (PTCAs) had been performed prior to TMLR. There was a history of myocardial infarction in 90.7% of patients and 89.8% were in the Canadian Cardiovascular Society (CCS) classes III or IV and 94.5% of them were in the NYHA classes III or IV. The left ventricular ejection fraction was 49.5 +/- 16.4% and all of the patients were under intense antiischemic medical treatment which included nitrates or molsidomine in 96.9%, beta blockers in 53.1%, angiotensin converting enzyme inhibitors (ACE inhibitors) in 44.5%, digitalis in 22.7% and diuretics in 52.3% of patients. The preoperative data on myocardial viability, inducible ischemia and coronary morphology provided important clinical information for the decision, which revascularizing method would be the most appropriate for each vessel or myocardial region. This had to be weighed against the patient's operative risk, which is predominantly determined by the left ventricular ejection fraction, the arteriosclerotic involvement of the remaining vascular system and concomitant diseases, particularly of pulmonary origin.

Under normal conditions the coronary system of the human heart is not hermetically isolated from the surrounding structures nor the ventricles, but is in various ways connected to the adjacent arteries and the cardiac chambers. These natural connections have been models for most surgical efforts to revascularize the myocardium. Numerous anastomoses between the aorta and the coronary branches functionally resemble aorto-coronary bypass grafts. Coronaro-ventricular anastomoses do also exist in the myocardium and therefore transmyocardial laser revascularization should allow blood to penetrate from the ventricle into the myocardium. This process should not be called "reptilization" of the human heart, as in large reptilian hearts the nutrition of an extensive amount of myocardium only by diffusion is highly unlikely. Transmyocardial laser revascularization results in a relevant reduction of clinical symptoms and an increase of exercise capacity in approximately two thirds of the patients treated. Objective data of enhanced myocardial perfusion as assessed by positron emission tomography and stress echocardiography has up to now only been presented by smaller studies. Open laser channels are rarely visualized by conventional ventriculography for the limited resolution of the technique. Possibly contrast-echocardiography may offer a more appropriate option to proof the systolic filling of the laser channels, as recently reported in patients. This would allow a correlation between clinically successful revascularization and functioning channels in contrast to an early or late failure due to the closure of the channels. As to the current opinion, transmyocardial laser revascularization is no alternative to established medical, interventional or surgical therapies but may in conjunction with bypass surgery or as a sole procedure offer a new option for those patients, who were recently considered to be refractory to conventional treatment. Experimental studies in particular should contribute to the understanding of therapeutic mechanisms and lead to standardized indications in the surgical treatment of end-stage coronary heart disease. Even though in transmyocardial laser revascularization the perioperative risk depends mainly on the degree of cardiac disease and the overall state of the patient, and impaired left ventricular function is per se no exclusion criterium, if viable myocardium is detectable. Many questions concerning indications, long-term prognosis and pathophysiological mechanisms are still open to discussion and have to be answered in order to find standardized applications for treatment of end-stage coronary artery disease.

Transmyocardial laser revascularization refers to the perfusion of the reptilian heart with its large ventriculo-myocardial channels and to well-known ventriculo-coronary connections in congenital heart defects. By a high energy CO2-laser transmural channels can be created at a beating heart and may, by connecting to the intramyocardial capillary network or by inducing a neocapillarization, improve the blood supply to the ischemic myocardium. This indirect method of revascularization is indicated in symptomatic patients with diffuse coronary heart disease, not accessible by conventional methods like PTCA or coronary bypass surgery. Worldwide, this new kind of operation has already been performed in some 100 intractable patients. In our hospital 79 patients have been treated with this new technique, 37 of them in conjunction with conventional bypass surgery. The majority of those patients had already undergone one or two bypass operations. The perioperative mortality was 11.4% including three non cardiac events. Postoperative follow-up after 3 and 6 months showed among the reinvestigated patients a significant improvement concerning angina- (CCS) and clinical classification (NYHA). Scintigraphy after the same time period revealed an improvement of myocardial perfusion in 50% of the reinvestigated patients. These results as well as the international reports demonstrate a clinical efficacy of this new therapeutic approach in a selected group of severely diseased patients. Further objective data and also experimental studies have to confirm the role of this new method in the treatment of diffuse coronary heart disease.

In symptomatic endstage coronary artery disease after full medical therapy (antianginal drugs, betablockers and ACE-inhibitors) further therapeutical options both for the interventional cardiologist with little hope for improvement by PTCA, stent, rotablation and atherectomy and for the cardiac surgeon with bypass surgery and endarterectomy are not available by definition due to the diffuse arteriosclerotic vessel morphology. In those patients one can therefore consider transmyocardial laser therapy (TMR) as the ultimate treatment option. It then is primarily a palliative measure to reduce the patient's symptoms. Improving perfusion and prognosis remains the most important goals, however. TMR can be utilized as the only revascularizing treatment measure or in combination with CABG or PTCA. According to data from international registries, few controlled and several non controlled studies and our own registry in Marburg with now 101 patients improvement of angina and/or dyspnoea can be expected in more than 60% of patients with end stage coronary artery disease (CAD). The patient cohort comprises symptomatic individuals after CABG or multiple PTCAs or with diffuse CAD in diabetes mellitus or with most severe hypercholesterinemia. We consider these above mentioned criteria as the only validated criteria to enter patients with endstage CAD in our controlled study. Hypothetical options for treatment by TMR such as vasculopathies after heart transplantation, cardiomyopathies under the notion of a possible but not proven microangiopathy are not accepted in our institution at present. Before TMR all patients are assessed for their angina class according to the Canadian Cardiac Society (CCS I-IV)) and their exercise capacity according to the New York Heart Association classification (NYHA I-IV) and reassessed regularly after 3, 6 and 12 months. Thallium/Te MIBI scans at rest- and whenever possible at exercise as well as stress echocardiography are carried in the patients to assess symptomatic improvement, alterations in myocardial perfusion and functional efficacy by TMR. By intermediate analysis the 101 patients of our registry more than 60% of the patients had improved their angina class by at least one classe, some patients have improved perfusion as assessed by scintigraphy, which makes at present a trend but not yet a significant difference, whereas central hemodynamics and ejection fraction remained virtually unchanged in most patients reassessed after TMR. In our analysis mortality of the 101 TMR patients was assessed and plotted on Kaplan Meier survival curves. Mortality at 6 months was 11%. When compared to a historical group of patients with identical CCS and comparable NYHA classes, who were worked up in the manner of a case control study, the TMR mortality was marginally but not yet significantly lower than one would expect from these control patients with terminal CAD treated purely by medication: Their 6 months mortality was 14%. Remarkably but not unexpectedly patients with comparable CCS classes, who could still be treated by PTCA and/or CABG had a significantly lower 6 months mortality than TMR patients or patients on antianginal drugs only. The pathophysiological mechanisms for the symptomatic improvement by laser therapy are not yet fully understood. The 1 mm transmyocardial channels created by the CO2 laser have been postulated to permit perfusion from the ventricular cavity and to seek connection to capillaries and vessels present in the malperfused myocardium thus improving the perfusion by newly created connections and sinusoids from the ventricular cavity. Although there is clear evidence for the presence of open channels acutely and within a few days after TMR therapy little evidence in man is as yet available on the question whether the channels remain open in the long run and, if so, whether they can actually improve perfusion to a substantial degree...

Indications for interventional catheter techniques and bypass surgery have been extended to more complex lesions and also the number of reoperations after primary successful interventions has increased due to progression of the underlying disease. Finally a number of patients remains still symptomatic but, as a consequence of a very diffuse distribution of atherosclerotic lesions, is no longer accessible with conventional techniques of direct revascularization. This has drawn the attention again to indirect techniques of myocardial revascularization. Transmyocardial laserrevascularization offers a new option in reperfusing the ischemic myocardium via transmural channels from the ventricular cavity. As to the function of the channels, it is not quiet clear, wether they may connect to intramyocardial capillaries or may themselves induce a neoangiogenesis. However the clinical follow up in patients with intractable angina pectoris shows a significant improvement. At our hospital a number of 117 patients have been treated with this new method, 53 of them in conjunction with conventional bypass surgery. Clinical follow up after three and six months postoperatively showed a significant improvement concerning angina (CCS) and exercise tolerance (NYHA). This could also objectively be demonstrated by scintigraphy with an increased myocardial perfusion in 50% of the reinvestigated patients. Ischemic areas can still be seen, but occur at a significantly higher exercise level, demonstrating an improved but not normalized myocardial blood supply. The transmyocardial laserrevascularization is no alternative to well established procedures like PTCA or bypass surgery, but can be seen as a therapeutic option for those symptomatic patients recently being intractable. Further longterm studies and also experimental investigations have to evaluate the definitive role of this new treatment for endstage coronary heart disease.

The use of laser in bronchology plays a major role in the therapy of benign and malignant tumours. By flexible delivery systems, lasers can be used in combination with flexible bronchoscopes. By this benign tumours, especially in young children, can be ablated successfully without major surgical intervention. In malignant tumours laser ablation can only be used as a palliative procedure in cases untreatable by conventional surgery or prior to radiation or chemotherapy, in which the symptoms of hemopthysis or significant obstruction are indications for an urgent treatment. Especially in elder patients a quick relief of symptoms can be reached avoiding the high risks of an operation. A new and experimental field of laser application in bronchology is the tracheal reconstruction with laser assistance. In 10 Beagle dogs laser assisted tracheal anastomoses revealed good functional results with an uneventful postoperative course. Histology showed a normal healing and a good reconstruction of the ciliated endothelium without metaplastic changes. So this new technique may in future become an additional tool in the reconstructive surgery of the trachea and main bronchi.

Tracheal anastomoses are known to be related to special surgical risks. We performed laser-assisted trachea anastomoses in 10 Beagle dogs, using an Argon-laser system and a handheld quarz fiber for energy transmission. All animals showed an uneventful postoperative course without signs of infection, air-leakage or respiratory impairment. Pathologic examination revealed no significant stenosis but a normal reconstruction of the tracheal endothelium and a normal woundhealing with only an increased connective tissue reaction. Because of the lower tensile strength of laser-assisted anastomoses in general, three adapting absorbable sutures should be left in situ to increase the resistance against mechanical stress. Under these circumstances laser-assisted anastomoses seem to be a promising additional method in the field of tracheal reconstruction and transplantation.