Preventing the lung cancer epidemic.
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Disease Outbreaks↗
Biomedical subjects
C Dresler
Publications and source records attributed to C Dresler.
Toward a comprehensive long term nicotine policy.
Global tobacco deaths are high and rising. Tobacco use is primarily driven by nicotine addiction. Overall tobacco control policy is relatively well agreed upon but a long term nicotine policy has been less well considered and requires further debate. Reaching consensus is important because a nicotine policy is integral to the target of reducing tobacco caused disease, and the contentious issues need to be resolved before the necessary political changes can be sought. A long term and comprehensive nicotine policy is proposed here. It envisages both reducing the attractiveness and addictiveness of existing tobacco based nicotine delivery systems as well as providing alternative sources of acceptable clean nicotine as competition for tobacco. Clean nicotine is defined as nicotine free enough of tobacco toxicants to pass regulatory approval. A three phase policy is proposed. The initial phase requires regulatory capture of cigarette and smoke constituents liberalising the market for clean nicotine; regulating all nicotine sources from the same agency; and research into nicotine absorption and the role of tobacco additives in this process. The second phase anticipates clean nicotine overtaking tobacco as the primary source of the drug (facilitated by use of regulatory and taxation measures); simplification of tobacco products by limitation of additives which make tobacco attractive and easier to smoke (but tobacco would still be able to provide a satisfying dose of nicotine). The third phase includes a progressive reduction in the nicotine content of cigarettes, with clean nicotine freely available to take the place of tobacco as society's main nicotine source.
Health Policy↗
[Referral by a general practitioner versus self-referral to a specialist practice. A comparison using chronic venous insufficiency as an example].
BACKGROUND AND OBJECTIVE: The gate-keeping role of general practitioners (GPs) is currently the topic of much debate in Germany. Currently it is possible for patients in Germany to see a specialist either through referral by their GP or directly through self-referral. To determine whether the gate-keeping role of GPs has a filtering effect, we compared patients referred by their GPs with self-referred patients presenting with suspected chronic venous insufficiency (CVI) to a specialist practice. PATIENTS AND METHODS: From September to December 2001, we prospectively recruited 316 patients seen for suspected CVI in a specialist practice for vascular surgery and phlebology. Symptoms and clinical findings were recorded using a standardized form. RESULTS: 58.2 % of patients were referred by their GPs. These patients were on average 6 years older and presented at a more advanced stage of disease than self-referred patients. No difference was found between patients with and without referral with respect to the symptoms reported or the therapy recommended by the specialist. CVI was excluded in 7.1 % of patients with a referral and in 6.8 % of those without a referral. CONCLUSIONS: The majority of patients consulting a specialist were referred by their GP. The more advanced disease stage of these patients indicates that a filtering process occurs in referral by GPs. However, the share of patients without referrals in whom CVI could be excluded was low and not significantly different from that of patients with referrals. This indicates that misdiagnosis due to self-referral is relatively modest. A cost reduction effect in a gate-keeper system could therefore only be small.
Adult↗
Endoluminal grafting of abdominal aortic aneurysms: experience with the Talent endoluminal stent graft.
The aim of this study was to evaluate the Talent endoluminal stent graft (TESG) in treating abdominal aortic aneurysms (AAA). The TESG is a polyester-covered nitinol endograft (proximal diameters 20-38 mm and iliac limb diameters 8-22 mm). Twenty-two men were treated with the TESG via bilateral femoral arteriotomies. Pre-implantation, coil embolization of various vessels arising from the aneurysm was performed in 6 patients. Plain radiographs and spiral CT angiograms (CTA) were carried out at 7 days, 3, 6, and 12 months following TESG implantation or re-intervention. Median aortic and iliac diameters were 27 mm (range 20-34 mm) and 14 mm (range 10-19 mm). The corresponding graft diameters were 30 mm (range 24-38 mm) and 14 mm (range 12-20 mm). No patient was rejected purely on the basis of too large aortic or iliac diameters. Eight patients required custom-made grafts. Graft implantation was successful in all patients. There were no blood transfusions, distal embolic episodes, or conversions to open surgery. Re-intervention was necessary in 1 patient. Complications included one fatal myocardial infarction, one inguinal hematoma, and two superficial wound infections. The aneurysm thrombosed completely following implantation in 14 patients and at 3 or 6 months in 4 other patients. One patient with endoleak is awaiting his 3-month control and 2 patients show tiny endoleaks but reduction of aneurysm size. The mean aneurysm size decreased significantly from 58 +/- 10 to 53 +/- 13 mm (p < 0.0005). Due to the large sizes available and the option of custom-made grafts, the TESG helps widen the spectrum of patients who can be treated with endoluminal grafting. The treatment is associated with a significant reduction in aneurysm size.
Aged↗
CT depiction of regional nodal stations for lung cancer staging.
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Adult↗
Predictors of proximal aortic dissection at the time of aortic valve replacement.
BACKGROUND: Type I aortic dissection develops in 0.6% of patients late after aortic valve replacement (AVR), and 13% of patients with type I aortic dissections have a history of AVR. Predictors of aortic dissection at AVR, however, have not been characterized. METHODS AND RESULTS: A study group of 33 patients with type I aortic dissection had aortic surgery 49+/-55 months after routine AVR. A group of 101 controls, who did not have morphological progression of aortic diameters >/=6 years after AVR, was used to identify predictors of postsurgical dissection. Multivariate analysis identified aortic regurgitation (P<0.002) and fragility (P<0.001) or thinning of the aortic wall (P<0.007) at AVR as predictors, associated with a 14%, 22%, and 7% probability of late aortic dissection, respectively. Clamping times, types of valve prostheses, concomitant coronary artery bypass grafting, and mean ascending aortic diameters of 43+/-10 mm at AVR did not predict late dissection. A separate analysis of 29 nondissecting aneurysms of the ascending aorta developing 104+/-64 months after routine AVR revealed younger age at AVR (P<0.003) and congenitally bicuspid aortic valves (P<0.03) as predictors of late aneurysm formation. CONCLUSIONS: Aortic regurgitation combined with fragile and thinned aortic walls in patients with moderate aortic dilation may reflect aortic root disease, with a high risk for postsurgical aortic sequelae if it is treated incompletely by isolated valve replacement.
Adult↗
Two-stage repair of a combined aneurysm of the descending aorta and the aberrant right subclavian artery.
In cases of combined aneurysms of the descending aorta and the aberrant right subclavian artery a common surgical strategy has not been clearly elaborated. In this report the case of a 76-year-old male patient with this rare combination of aneurysms is presented. The surgical strategy consisted of a two-stage approach for repairing both aneurysms maintaining the perfusion of the right subclavian and vertebral artery, finally providing an excellent postoperative result even in a patient of this advanced age.
Aged↗
[Aortic valve replacement as an independent predictive factor for later development of aortic dissection].
Dissection of the ascending aorta (type A) following later after aortic valve replacement has been described with increasing frequency. This study analyzes the role of aortic valve replacement for the evolution of late dissection. In a series of 80 consecutive patients with type A dissection, a previous aortic valve replacement had been performed in 12 cases (15%). In addition to arterial hypertension (p < 0.001) and Marfan syndrome (p < 0.01), multivariate analysis identified previous aortic valve replacement (p < 0.01) as an independent predisposing factor for type A dissection. Dissection occurred 3 +/- 4 years after aortic valve replacement with a clinical and anatomical profile similar to classic dissection as proven by comparison to a group of 62 patients with classic dissection associated with arterial hypertension or Marfan syndrome. With 75% and 66%, respectively, 30 day and 1 year survival of patients with dissection following later after aortic valve replacement was similar to patients with classic type A dissection. Extensive thinning and/or fragility (p < 0.05) of the aortic wall in the presence of a mildly dilated aorta (45 +/- 5 mm) at the time of aortic valve replacement was associated with a high risk for late dissection; this finding was substantiated by comparison to a control group of 10 consecutive patients with a similarly dilated aortic root but no dissection. Type and diameter of valve prostheses, cross-clamp time, NYHA functional class, and left ventricular ejection fraction were unrelated to late dissection. Previous aortic valve replacement is an independent predisposing factor for a dissection of the ascending aorta later. At the time of aortic valve replacement, prophylactic replacement or wrapping of the ascending aorta should be considered in patients with a thinned/fragile aortic wall even without a markedly dilated aortic root.
Adult↗
The role of spinal angiography in operations on the thoracic aorta: myth or reality?
BACKGROUND: The importance of preserving the artery of Adamkiewicz during replacement of the thoracoabdominal aorta is debated. We report our experience with the use of preoperative spinal angiography and modification of the surgical technique. METHODS: Between September 1993 and March 1996, 46 patients (mean age, 57 years; range, 25 to 73 years) underwent spinal angiography at our institution, 23 for an aneurysm and 23 for chronic dissection. Localization of the artery of Adamkiewicz between T-9 and L-3 was successful in 30 (65%) patients: T-9, left = 2, right = 1; T-10, left = 4; T-11, left = 10, right = 2; T-12, left = 3, right = 1; L-1, left = 1, right = 2; L-2, left = 2, right = 1; and L-3, left = 1. Thirty-one patients subsequently underwent replacement of the descending thoracic aorta and 13 underwent replacement of the thoracoabdominal aorta. Left atrial-femoral artery bypass was used in 23 patients and full extracorporeal circulation was used in 20 patients. Twelve procedures included the reimplantation of crucial intercostal/lumbar branches. RESULTS: The operative mortality rate was 6.8% (3 of 44 patients) and 1 (2.27%) patient had paraparesis. In addition to the 12 patients who underwent targeted reimplantation of the intercostal branches, evaluation of the spinal cord blood supply influenced the operative technique in 19 other patients. CONCLUSIONS: Selective angiography can demonstrate the spinal cord blood supply even in patients with complex aortic pathology. It is a helpful tool for planning extensive replacement of the thoracic and thoracoabdominal aorta.
Adult↗
Composite graft replacement of the aortic root in 335 patients with aneurysm or dissection.
The hypothesis that replacement of the aortic root with a valved composite graft is a safe and effective therapy for aneurysms involving the sino-tubular segment of the aorta was tested by a retrospective review. From September 1978 to January 1995, 335 consecutive patients underwent prosthetic aortic root replacement as the primary operation for aneurysm (222) or dissection (acute 59, chronic 54). There were 248 men (74%) and 87 women (26%) with a mean age of 50 +/- 14 years. 22 patients (6.6%) experienced hospital death primarily due to cardiac causes. Mortality was significantly higher in patients with acute dissection versus those with non-dissecting aneurysms and chronic dissection. Sex, Marfan syndrome (20.3% of patients), mitral regurgitation, coronary artery disease, and era of operation had no effect on early outcome. Mortality was significantly increased in patients aged over 50 years, in those with circulatory compromise, and in patients requiring emergency operation. Follow-up was complete in 313 survivors (97%) at a mean of 61.3 +/- 44 months. Actuarial survival was 80% at 5 and 67% at 10 years. There were no complications involving the coronary anastomoses, other than infection-related, regardless of the mode of ostial reattachment.
Acute Disease↗
Intrapericardial pheochromocytoma.
Pheochromocytoma are catecholamine-secreting tumors occurring in less than 1% of the hypertensive population. Even though more sensitive methods have facilitated the diagnosis of intrathoracic paragangliomas they still remain extremely rare. This study reports a patient with a cardiac pheochromocytoma in whom the tumor was located on the outside of the roof of the left atrium and involved the left main coronary artery. Due to this anatomy the resection of the tumor required a cardio-pulmonary bypass and transsection of the pulmonary artery. The postoperative course was uneventful and the patient could be discharged without significant hypertension.
Cardiopulmonary Bypass↗
Carotid-subclavian bypass for subclavian artery revascularization: long-term follow-up and effect of antiplatelet therapy.
Subclavian artery stenosis is found in up to 25% of supraaortic lesions. Bypass grafting is the procedure of choice but controversies exist concerning the optimal technique and the effect of postoperative antithrombotic therapy on long-term patency. The authors retrospectively analyzed 40 patients with carotid-subclavian bypasses. Stenoses were documented preoperatively by arteriography. Patency was determined by clinical, ultrasound, or arteriographic examinations. Cumulative patency rates were calculated by Kaplan-Meier method and analyzed by Tarone-Ware test. Graft materials were Dacron (32), polytetrafluoroethylene (seven) or saphenous vein (one). Indications for surgery included vertebrobasilar insufficiency (22.5%), upper extremity ischemia (22.5%), and the combination of both (55.0%). Perioperative mortality and morbidity were 2.5% and 10.0%, respectively. Patients were followed up from 0 to 134 months (mean 61+/-39 months). Cumulative 5-year patency rate was 83.3%. Anticoagulation with acetylsalicylic acid (ASA) led to significantly better 5-year patency rates (100%) as compared with the combination of ASA and dipyridamole (64.0%, p=0.013) or no anticoagulation (70.0%, p=0.016). Carotid-subclavian bypass led to excellent long-term patency rates and can provide durable relief of symptoms with minimal perioperative morbidity and mortality. Therefore, it is a worthwhile procedure to correct proximal subclavian artery stenosis. Postoperative medication with ASA seems to increase long-term bypass function significantly.
Adult↗
Surgical treatment of Marfan patients with aneurysms and dissection of the proximal aorta.
BACKGROUND: The authors retrospectively analyzed early and late results of surgical treatment for 79 Marfan patients with aneurysms and dissection of the proximal aorta. METHODS: From September 1979 to February 1996, 79 patients with Marfan syndrome underwent aortic root replacement using composite grafts (n=68, Bentall-technique 63, button-technique 5), and ascending aortic replacement with a valve-sparing procedure (n=11). There were 12 patients (15.2%) who simultaneously received partial or total arch replacement. 55 patients (69.6%) were male, and 24 female (30.4%). The average age was 33.8 years. Forty-one patient (51.9%) had non-dissecting aneurysms while the remaining 38 patients suffered from either acute (24.0%) or chronic aortic dissection (24.0%). The aortic valve was involved in 97.5% of all cases. RESULTS: The total early mortality (< or =30 days) was 3.8%, 10.5% for acute aortic dissection and 2.4% for non-dissecting aneurysms. There were no early postoperative deaths in patients after valve-sparing operation and in those with chronic aortic dissection. The follow-up rate was 98.7%. During a mean follow-up of 68+/-25 months 10 patients (13.3%) died and cardiac complications were a common cause of the late deaths. There was no late mortality in the valve-sparing operations during a mean follow-up period of 8+/-6 months, however, 1 required valve replacement. 19 (25.3%) of the 75 patients surviving late have undergone 25 secondary operations on the cardiovascular system. Reoperations at aortic sites distant from the original were much more frequent after primary repair for acute and chronic dissection when compared to non-dissecting aneurysms (p<0.005). Actuarial survival rate of all patients with composite graft replacement including early deaths was 91.2% at 1 year, 84.4% at 5 years and 75.2% at 10 years. CONCLUSIONS: Composite graft insertion has become the gold standard for treating Marfan-patients with non-dissecting and dissecting aneurysms of the aortic root. Our early experience in 11 patients with valve-sparing procedures indicated that this,variant may be the better choice in selected patients.
Adult↗
Intravascular ultrasound-guided percutaneous fenestration of the intimal flap in the dissected aorta.
BACKGROUND: Aortic dissection with branch obstruction is associated with high morbidity and mortality. Fenestration of the dissection flap to relieve distal vessel ischemia is at present largely performed surgically. The surgical mortality and morbidity are high, because most patients are poor candidates for anesthesia or surgery. METHODS AND RESULTS: Nine percutaneous fenestrations (one with additional stenting of the infrarenal true aortic lumen) were performed under local anesthesia in seven patients with aortic dissection. The presenting symptoms were abdominal angina or claudication. By the transfemoral approach, the intimal flap was initially punctured with a needle-catheter combination through which a guidewire was placed across the dissection flap. The fenestration was carried out with a balloon catheter introduced over the guidewire. The procedure was performed under on-line guidance with intravascular ultrasound imaging. The procedure was performed successfully and without complications in all patients. After intervention, symptoms resolved in all seven patients. CONCLUSIONS: Intravascular ultrasound-guided percutaneous fenestration of the intimal flap in symptomatic aortic dissections with distal vessel involvement is a technically feasible and safe procedure that can effectively relieve the patient's symptoms.
Adult↗
Open heart operations after renal transplantation.
BACKGROUND: Because of the increasing number of renal transplantations performed, secondary cardiac operations in these patients are discussed concerning their impact on patient and graft survival. METHODS: We reviewed our experience in 45 patients (33 male and 12 female) who underwent open heart operations after previous renal transplantation. Thirty-one patients (group I) received coronary artery bypass grafting and 14 (group II) underwent valve replacement. Mean age at the time of operation was 55 +/- 9 years. The interval between renal transplantation and cardiac operation was 57 +/- 39 months (range, 5 days to 174 months). All patients had functioning renal allografts with preoperative serum creatinine levels ranging from 100 to 338 mol/mL (mean +/- standard deviation, 195 +/- 86). RESULTS: Overall early operative mortality (30 days) was 8.8% (group I, 1 patient; group II, 3 patients). Underlying causes of death were septic endocarditis (n = 2, group II), necrotizing enterocolitis (n = 1, group I), and myocardial infarction (n = 1, group II). One further patient in group II also died of septic endocarditis after 69 days (in-hospital death). The mean follow-up of the 40 surviving patients was 44 +/- 31 months. There was another late death (24 months postoperatively) caused by coagulopathy. Four patients had returned to hemodialysis at intervals of 27 to 83 months (mean, 51 months) because of renal transplant failure. In all patients, the function of the renal allograft was not impaired by open heart operation. CONCLUSIONS: Open heart operations in renal transplant recipients have acceptable mortality and morbidity rates. In almost all patients, function of the transplanted organ can be maintained at the preoperative level.
Coronary Artery Bypass↗
Transvenous defibrillation leads: is there an ideal position of the defibrillation anode?
A potential benefit of two-lead transvenous defibrillation systems is the ability to independently position the defibrillation electrodes, changing the vector field and possibly decreasing the DFT. Using the new two-lead transvenous TVL lead system, we studied whether DFT is influenced by SVC lead position and whether there is an optimal position. TVL leads and Cadence pulse generators were implanted in 24 patients. No intraoperative or perioperative complications were observed. In each patient, the DFTs were determined for three SVC electrode positions, which were tested in random order: the brachiocephalic vein, the mid-RA, and the RA-SVC junction. The mean DFTs in the three positions were not statistically different, nor was any single lead position consistently associated with lower DFTs. However, an optimal electrode position was identified in 83% of patients, and the DFT from the best lead position for each patient was significantly lower than for any one of the electrode positions (P < 0.01). The mean safety margin for the best SVC lead position was approximately 27 J. These results demonstrate the advantage of a two-lead system, as well as the importance of testing multiple SVC lead positions when the patient's condition permits. Both of these factors can decrease the DFT and maximize the defibrillation safety margin. This will become increasingly important as pulse generator capacitors become smaller (as part of the effort to decrease generator size) and the energy output of the generators consequently decreases.
Adult↗
Combined-modality therapy for esophageal cancer: phase I trial of escalating doses of paclitaxel in combination with cisplatin, 5-fluorouracil, and high-dose radiation before esophagectomy.
Several recent reports support administering preoperative chemotherapy and radiotherapy to improve the outcome of patients with resectable esophageal malignancies. Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ), 5-fluorouracil (5-FU), and cisplatin are known radiosensitizers, and paclitaxel has demonstrated single-agent activity in patients with metastatic esophageal cancer. This study sought to define the maximum tolerated dose of paclitaxel given with 5-FU, cisplatin, and 60 Gy radiotherapy before esophagectomy to patients with potentially resectable lesions. Seventeen patients so treated underwent esophagectomy. Three patients with metastatic disease, treated to obtain more information about the toxicity of the combined-modality regimen, did not undergo surgery. Over 6 weeks, 60 Gy radiation was administered in 2-Gy fractions. During radiation treatment, continuous intravenous infusions of 5-FU 225 mg/m2/d were administered, with paclitaxel given weekly as a 1-hour intravenous infusion immediately preceding a 1-hour cisplatin infusion. Surgery was performed 4 to 6 weeks after the completion of radiotherapy. The 27 patients, one of whom was a woman, had a median age of 58 years and an Eastern Cooperative Oncology Group performance status of 0 (10 patients) or 1. Three patients had a squamous cell histology, while 22 had adenocarcinoma; two had other histologies. The paclitaxel dose levels were 25 mg/m2 in four patients, 40 mg/m2 in five patients, 60 mg/m2 in nine patients, and paclitaxel 50 mg/m2 with 5-FU reduced to 200 mg/m2 in nine patients. The latter proved to be the maximum tolerated dose combination, with cisplatin held constant at 25 mg/m2. This level represents weekly dose intensities of 9.6 Gy radiation, 48 mg/m2 paclitaxel, 24 mg/m2 cisplatin, and 192 mg/m2 5-FU. Diarrhea in four patients, mucositis and dehydration in seven, electrolyte wasting in two, gram-positive catheter-related infection in three, and neuropathy in one proved dose limiting. Hematologic toxicity was relatively mild, with three episodes of nonneutropenic bacteremia, one of which was fatal. Postoperative chemotherapy consisting of four cycles of paclitaxel 175 mg/m2 over 3 hours and cisplatin 75 mg/m2 over 1 hour every 3 weeks was planned but rarely feasible due to postoperative morbidity and poor tolerability of postoperative chemotherapy. Therefore, the use of two induction cycles of this regimen given before the combined-modality study regimen is currently being investigated. Of 17 patients whose surgical specimens were assessed pathologically, three had complete remissions and 14 had partial remissions, five of which were characterized as very good, showing only microscopic foci and marked radiation effects. The median follow-up of the 17 patients who underwent surgery is 50 weeks (range, 5 to 111 weeks). Three relapses occurred at 26, 33, and 43 weeks. We conclude that this is an intense combined-modality preoperative regimen for patients with esophageal cancer. Determining the efficacy of this regimen will require further follow-up and the performance of phase II trials.
Adenocarcinoma↗
[Supra-aortic bypasses for revascularization of the subclavian artery: early and late results of extra-thoracic and transthoracic methods: are extra-anatomic conduits superior?].
Subclavian artery stenosis is found in up to 25% of patients with supraaortic lesions. Bypass grafting is the recommended procedure of choice but there is still debate concerning the optimal technique. We therefore performed a retrospective analysis to determine the prognostic factors based on long-term results. Between 1974 and 1992, fifty-five patients were treated for subclavian artery stenosis. The methods used were carotid-subclavian artery bypass (KSBP, n = 40) and aorto-subclavian artery bypass (ASBP, n = 15). Indications for surgery included vertebrobasilar insufficiency (20.0%), upper extremity ischemia (20%) and the combination of both (58.2%). Arteriosclerosis was the predominant cause of disease (85.5%). Peri-operative mortality was limited to one patient in the KSBP-group (2.5%). Post-operative morbidity was significantly lower in the KSBP-group (10.0%) as compared to the ASBP-group (40.0%, p = 0.018). Relief of symptoms was achieved in 97.4% of KSBP procedures and in 92.9% of ASBP procedures. Patients were followed up for a mean period of 73.7 +/- 58.0 months. Cumulative 5-year patency rates of 71.4% (ASBP) and 83.3% (KSBP) were not significantly different between both groups (p = 0.089). Pharmacologic therapy with acetylsalicylic acid (ASA) led to a statistically significantly better 5-year patency rate (100%) as compared to the combination of ASA and dipyridamole (71.4%, p = 0.016) or phenprocoumone alone (50.0%, p < 0.001) or no anticoagulation (71.4%, p = 0.005). In our experience carotid-subclavian bypass has an excellent long-term patency rate with a low peri-operative morbidity as compared to transthoracic bypass procedures (ASBP). Therefore KSBP should be the procedure of choice to correct proximal subclavian artery stenosis. Platelet inhibitors will increase bypass patency rate significantly.
Adult↗