Contrasting histoarchitecture of calcified leaflets from stenotic bicuspid versus stenotic tricuspid aortic valves

AbstractPreliminary findings from clinical trials of percutaneous balloon aortic valvuloplasty and intraoperative debridement of calcific deposits in patients with aortic stenosis have suggested that calcified, congenitally bicuspid aortic valves may be less amenable to these techniques than are calcified tricuspid aortic valves. Accordingly, we evaluated the histoarchitecture of calcific deposits in 30 operatively excised aortic valves. Light microscopic sections taken through the calcified aortic valve leaflets disclosed two principal types of histoarchitectitre. In 11 aortic valves nodular calcific deposits were superimposed on an underlying fibrotic aortic valve leaflet (type A); in 17 valves calcific deposits were diffusely distributed throughout the body (spongiosa) of the aortic valve leaflets (type B). Two aortic valves could not be classified histologically.These histologic subtypes were not randomly distributed with regard to gross valvular morphology. All 14 bicuspid valves (100%) were type B; in contrast, 11 (69%) of 16 tricuspld aortic valves were type A, and only 3 (19%) of 16 tricuspid valves were type B (p < 0.01). Both valves with nonclassifiable histologic features were tricuspid on the basis of gross examination.Thus, the histoarchitectural distribution of calcific deposits is different for bicuspid than for tricuspid stenotic aortic valves. The more diffuse distribution of calcium throughout the body of calcified bicuspid aortic valve leaflets may render these valves less amenable to operative and percutaneous valvuloplasty than are calcified tricuspid aortic valve leaflets on which calcific deposits are typically superimposed in nodular form

Anewballoon-expandabletantalumcoilstent: Angiographicpatency and histologicfindings in an atherogenicswinemodel

AbstractThe angiographic patency and histologic characteristics of a new balloon-expandable tantalum stent were studied after implantation intervals ranging from 1 to 32 weeks in atherogenic miniature swine peripheral and coronary arteries. Stents were placed in 34 arteries (10 coronary and 24 iliac arteries) in a total of 13 swine. Two swine died within 24 h of stent implantation. Follow-up angiography was performed before death was induced in 11 swine (8 coronary and 19 iliac arteries) and revealed 100% patency without evidence of lumen stenosis, thrombosis or migration of the stents. The neointimal thickening was maximal at 4 weeks after stent implantation and was at its minimum at 32 weeks after implantation with reendothelialization of the stents generally complete at that time.An advantage of this balloon-expandable device is its inherent longitudinal flexibility. The coil configuration allowed the nondeployed stent to negotiate acute bends in coronary arteries to reach the site of implantation and also allowed the deployed stent to conform to the natural contour of tortuous coronary arteries. The tantalum device was remarkable for its radiographic visibility, which greatly aided its placement under fluoroscopic guidance. This study demonstrates this slent's ease of implantation, excellent patency rate and absence of restenosis due to neointimal proliferation for up to 8 months in this atherogenic swine model

Mortality and Morbidity

Historically, morbidity and mortality rates related to surgery for locally recurrent rectal cancer (LRRC) have been >70% and 30%, respectively [1\u20133]. Because of the excessive operative risks, the benefit of such resections has been questioned and \u2014 although radical operation for LRRC was conceptualized and reported more than 60 years ago \u2014 for years it has not been accepted as being standard procedure. More appropriate selection of candidates for resection due to advances in imaging modalities, improvement in surgical techniques, establishment of specialized multidisciplinary surgical teams, and improvement in quality of perioperative management have resulted in better outcomes in recent years. Currently, mortality rates vary between 0\u20135% at 1 month and 8% at 3 months [4]. The causes of death are mainly disseminated coagulopathies related to prolonged sepsis and blood loss, multiorgan failure, cardiac events, and pulmonary embolism [5, 6]. Morbidity remains significant, ranging from 15 to 68%, and increases with the complexity of resection [7\u201310]. Bleeding is the main and most severe intraoperative complication, and occurs in 0.2\u20139% of cases, and related mortality is high (4%) [11\u201314]. The principal postoperative complications include pelvic abscess (7\u201350%), intestinal obstruction (5\u201310%), enterocutaneous or enteroperineal fistulas (1.2%), perineal wound dehiscence (4\u201324%), and cardiovascular, renal, and pulmonary complications (1\u201320%) [5, 7, 8]