Predictive factors of restenosis: what changes with "active" stents?

For many years, restenosis was the major limiting factor of coronary angioplasty, even since the systematic use of stents. Numerous scientific publications have aimed to define the predictive factors of this phenomenon. Factors such as diabetes, the size of the treated artery, the use of stents or not, the length of the lesion, lesion located on the proximal left anterior descending artery, the degree of residual stenosis post-angioplasty (assessed by angiography or by intravascular ultrasound) have all been evoked as being classically related to restenosis. However, our perception of the restenosis phenomenon has been dramatically changed by the demonstration of the efficacy and security of active stents. Even in so-called "at risk" populations, the use of active stents is rarely followed by restenosis. In this way, the classic risk factors for restenosis have now become arguments in favour of the implantation of an active stent. As long as budgetary constraints limit the use of active stents to patients said to be "at risk of restenosis", this population, quite paradoxically, will have a more favourable outcome than so-called "low risk" patients, in whom "ordinary" non-active stents will continue to be used.     

Vascular restenosis - striving for therapy

Restenosis is the limiting entity following coronary angioplasty. It is associated with significant morbidity, mortality and cost, and thus represents a major clinical and economical problem. Despite technical improvements, restenosis after conventional balloon angioplasty occurs in 30 - 60% of cases. Coronary stenting was able to reduce the incidence by approximately 30%; nevertheless, some 250,000 patients experience in-stent restenotic lesions/year worldwide. In-stent restenosis has been recognised as very difficult to manage, with a repeat restenosis rate of 50%, regardless of the angioplasty device used. So far, only vascular brachytherapy has convincingly reduced the incidence of repeat in-stent restenosis (by 50%) and thus, has emerged as the gold standard of therapy. The introduction of drug-eluting stents has shown a great deal of promise for the treatment of both de novo and restenotic lesions, with reported restenosis rates of < 10%, and benefit for virtually all patient subsets at a higher risk of restenosis. This review outlines the pathophysiology, epidemiology and predictors of the restenosis process, and places emphasis on the various treatment options for its prevention and therapy.     

Clinical outcome of patients with left anterior descending artery ostial lesions treated with percutaneous coronary intervention: case-matched comparison with bypass surgery

Objective To assess the immediate and late clinical outcome of left anterior descending artery ostial lesions treated with percutaneous coronary intervention.Methods Seventeen patients (6 females and 11 males) treated with percutaneous coronary intervention for ostial left anterior descending artery stenoses have had clinical follow-ups over 12 months. Clinical events were defined as an occurrence of death, myocardial infarction, recurrent angina, and reguiring repeat revascularization (either by angioplasty or by surgery). A matched population treated with coronary bypass surgery was selected based on the similarities in age, left ventricular ejection fraction and the number of diseased vessels. Kaplan-Meier event-free survival curves were generated and the matched comparison was done using the Chi-square test (Mc Neimar method).Results In the catheter-based angioplasty group, the patients’ mean age was 63±8 years. One patient was treated with directional atherectomy plus balloon, 6 with rotational atherectomy plus balloon, 7 with stent and 3 with rotational atherectomy plus stent. Glycoprotein Ⅱb/Ⅲa antagonist was used in 4 cases. Initial procedural success without major complications was achieved in all cases. The mean reference diameter was 2.90±0.48 mm. The minimum lumen diameter increased from 1.05±0.30 mm to 2.40±0.45 mm, and the diameter stenosis decreased from 64%±7% to 8%±13%. During the follow-up period, adverse events reguiring repeat revascularization occurred in 8 patients. The event-free probability was 0.42±0.14 in a two-year period. In a matched population treated with bypass surgery (single mammary graft), only one event occurred, and the difference in event-free survival in two-year period between the two patient groups was significant.Conclusions Percutaneous coronary intervention for left coronary descending artery ostial lesion is technically feasible and safe, leading to an optimal early success rate, but has a higher risk of late restenosis and greater need for repeat revascularization than coronary bypass surgery.     

Prevention of recurrence and prolonged survival in primary central nervous system lymphoma (PCNSL) patients treated with adjuvant high-dose methylprednisolone

Five patients at risk for primary central nervous system lymphoma (PCNSL) recurrence were treated with high-dose methylprednisolone (HDMP) to prevent 'trafficking' of malignant lymphocytes into the central nervous system (CNS). HDMP was chosen because of its ability to stabilize the 'blood brain barrier (BBB)'. Three men with newly diagnosed PCNSL, ages 62, 76 and 78y, whose survival was projected to be 6.6 months, began treatment after achieving complete response (CR) to initial radiation therapy alone and survived 27, 37 and 59 months after treatment. In none was death from recurrent disease in CNS but one patient did die of systemic non-Hodgkin's lymphoma (NHL) five years after PCNSL diagnosis. A 20 y old man was treated with HDMP after successful combined modality therapy and is alive 75+ months after initial diagnosis without evidence of disease recurrence. A 34 y old man relapsed after combined modality initial treatment and failed to respond to HDMP when treatment was begun after unsuccessful salvage therapy; he died of disease 12 months after initial diagnosis. There were no treatment complications. The promising results in this pilot study from the basis for a North Central Cancer Treatment Group (NCCTG) 96-73-51, a Phase 2 clinical trial of brain radiotherapy and HDMP for PCNSL patients 70y of age and older, a group of patients at high risk for toxicity from intensive combined modality therapy.     

Detection of carbamyl phosphate synthetase 1 deficiency using duodenal biopsy samples

The activity of urea cycle enzymes was assayed in duodenal biopsy specimens obtained from a female infant who presented with neonatal hyperammonaemia. All enzyme levels were normal except N-acetyl glutamate-dependent carbamyl phosphate synthetase 1 (CPS1) which was half the mean activity in normal control specimens. A similar deficiency of CPS1 was also shown in duodenal specimens from the patient's mother who became slightly symptomatic after relatively high protein meals and during pregnancy, and had spontaneously modified her diet to one with protein restriction. The patient is growing normally on a dietary regimen similar to that spontaneously adopted by her mother. Urea cycle enzyme activity in the duodenal biopsy material from the controls was similar to that found in the normal human liver and appears to have distinct advantages as a means of assaying for urea cycle defects in patients with hyperammonaemia and their relatives.     

Hilar masses: evaluation with CT-guided biopsy after negative bronchoscopic examination

Computed tomography (CT)-guided biopsies of 20 patients with hilar masses were performed after non-diagnostic bronchoscopic examination. Bronchoscopy included washings, brushings, routine biopsy, and, in many cases, transbronchial biopsy. In all but one case (95%), biopsy with a 22-gauge needle permitted a cytologic diagnosis of malignancy. In 14 of the 19 cases (74%), a diagnosis of primary lung carcinoma involving the hili was made, and in the remaining five of the 19 (26%), metastatic hilar adenopathy from an extrathoracic primary tumor was identified. A pneumothorax rate consistent with our average rate for CT-guided biopsies (25%) was obtained, and only one patient required chest tube placement. In this series, CT-guided biopsies of hilar masses were more consistently successful in obtaining tissue for diagnosis than were bronchoscopic biopsies. Transthoracic needle aspiration biopsy may be the preferred initial diagnostic procedure in many patients with hilar masses.     

Risk to Tourists Posed by Wild Mammals in South Africa

BACKGROUND: One of South Africa's principal tourist attractions is the opportunity to encounter Africa's large mammals in the wild. Attacks by these mammals can be exceptionally newsworthy with potentially deleterious effects on tourism. Little is known about the risk of injury and death caused by wild mammals to visitors to South Africa's nature reserves. The aim of this study was to determine the incidence of fatal and nonfatal attacks on tourists by wild mammals in South Africa and to ascertain avoidable factors, if any. METHODS: Commercial press records covering all South African Newspapers archived at the Independent Newspapers' central library were systematically reviewed for a 10-year period, January 1988 to December 1997 inclusive, to identify all deaths and injuries to domestic and international tourists resulting from encounters with wild mammals in South Africa. All of these incidents were analyzed to ascertain avoidable factors. RESULTS: During the review period seven tourists, including two students from Thailand and a German traveler, were killed by wild mammals in South Africa. Three of the four deaths ascribed to lions resulted from tourists carelessly approaching prides on foot in lion reserves. A judicial inquiry found that the management of a KwaZulu-Natal Reserve was culpable for the remaining death. Tourist ignorance of animal behavior and flagrant disregard of rules contributed to the two fatalities involving hippopotami. The unusual behavior manifested by the bull elephant responsible for the final death, resulted from discomfort caused by a dental problem to this pachyderm. During the same period there were 14 nonfatal attacks on tourists, including five by hippo, three by buffalo, two by rhino, and one each by a lion, leopard, zebra and musth elephant. Only the latter occurred while the visitor was in a motor vehicle. Tourist ethological naivete and failure to determine the experience of trail guides prior to travel, resulted in inadvertent agonistic behavior, unnecessary risk-taking and avoidable injury. CONCLUSIONS: This retrospective study has shown that attacks on tourists by wild mammals in South Africa are an uncommon cause of injury and death. Sensible precautions to minimize this risk include remaining in a secure motor vehicle or adequately fenced precincts while in the vicinity of large mammals, rigidly observing nature reserve instructions, never approaching animals that appear ill, malnourished, displaying aggressive behavior traits or female wild mammals with young, and demanding adequately trained and experienced game rangers when embarking on walking trails. Any behavior that might be construed as antagonistic and which could provoke an attack by large mammals should be avoided (e.g., driving directly at a lion). Visitors need to be informed of classic signs of aggression, in particular in elephants, which will allow timely avoidance measures to be taken. The risk-enhancing effect of excessive alcohol intake is undesirable in the game reserve setting, as is driving at high speed after dusk in areas where hippos graze. Local advice on personal safety in wildlife reserves and the credentials of trail guides should be obtained from lodge or reserve management, tourism authorities or the travel industry prior to travel to game reserves.     

Primary cutaneous carcinosarcoma: review and presentation of a case with emphasis on clinical characteristics and management

Carcinosarcomas are rare malignant biphasic tumours that contain intermingled carcinomatous and sarcomatous elements. Primary cutaneous carcinosarcomas (PCCS) are extremely rare. We present the 20th reported case and review the literature especially regarding histogenesis and clinical features such as diagnosis and management. PCCS resembles other non-melanocytic neoplasms of the skin. Diagnosis is obtained by primary excision with subsequent histologic and immunohistochemical examination. PCCS is a potentially lethal neoplasm, but radical surgery is successful in most cases.