Complicated acute type B dissections: a single-center experience with endovascular treatment.

BACKGROUND: Complicated acute type B dissections treated surgically carry a high risk of mortality. Endovascular interventions with stent-graft prostheses are a less invasive alternative and may obviate the need for surgery in most cases. We report here on our five years' experience with endovascular stenting in complicated acute type B dissections. PATIENTS AND METHODS: Between March 2001 and January 2006, 32 patients (27 males, 5 females) with a mean age of 61.4+/-11.32 years (range 29-80) underwent stent grafting for complicated acute type B dissections. Indications were progression of dissection with impending rupture (n=10), uncontrollable hypertension (n=9), intractable thoracic pain (n=7), and malperfusion syndrome (n=6). Talent-Medtronic (n=34) and Excluder-Gore (n=3) stent-grafts were used. In 5 patients two stents were necessary. In addition to stent grafting, aortic fenestration was performed in all three cases with lower limb ischemia. RESULTS: Endovascular stent placement was successful in all patients. Hospital mortality was 9.3% (3/32). No deaths occurred during follow-up (mean 32 months). CONCLUSION: Endovascular stenting of complicated acute type B dissections represents a safe alternative to surgery. Endovascular stent-grafts of appropriate sizes should be readily available in the hospital for emergency use, thus avoiding delays in treatment.

[How well aware of their risk profile are patients with peripheral occlusive arterial disease?]. / Fragebogenaktion zur arteriellen Verschlusskrankheit: Kennen die Patienten ihr individuelles Risiko?

Today, the majority of physicians no longer consider the well-informed patient to be something of a headache--rather, they welcome him as a partner in the management of his disease. The reason for this is that the more he knows about his illness, the more reliably will he comply with the physician's proposed treatment, the more readily he will be- come aware of side effects, and will thus actively contribute to his recovery. With the aid of easy-to-complete questionnaires, the state of knowledge of POAD patients about their disease was determined. The information thus gained may be considered the basis for an individual physician/patient talk.

[Regional hyperthermic fibrinolytic perfusion as ultima ratio in critical ischemia of the lower extremities]. / Regionale hypertherme Fibrinolytika-Perfusion als ultima ratio bei kritischer Ischämie der unteren Extremitäten.

In 19 patients (male-female: ratio 10:9; median age 67.1 (42-90) years) with a critical ischaemia of the lower extremities either after failed attempt of revascularization (n = 4) or because of lacking possibility for vessel reconstruction measures (n = 16) a regional extremity perfusion with a fibrinolytic agent has been performed using a heart lung machine. In one patient both lower extremities were treated. In the first 30 minutes of the total 60 minutes perfusion time on average 31 mg (20-50 mg) of recombinant tissue-plasminogen activator (Actilyse) have been added to the perfusion solution. In order to enhance the fibrinolysis-activity the perfusion solution was warmed up to 40 degrees C. Systemic side effects have not been observed. Two patients died postoperatively because of their underlying diseases (mesenteric artery embolism, myocardial infarction), two patients experienced postoperative haemorrhage and one patient had a wound infection. In 11 cases (55%) an opening of the stem-arteries has been reached. Seven of these were successfully revascularized with a femoro-crural bypass in a following operation. Nine extremities (45%) remained without opening of the stem-arteries, however, in four cases (20%) an improved radiographic contrast of the collaterals has been reached. 11 (61%) of the followed-up extremities were successfully revascularized. Amputation has been performed in seven cases (39%). The regional hyperthermic perfusion with fibrinolytic drugs enables a reopening of the stem-arteries and the creation of accepting vessels for vascular procedures in primarily inoperable arterial occlusions.

Experimental and clinical experiences with double-velour woven Dacron prostheses.

Double-velour woven Dacron prostheses were investigated both experimentally and clinically. In 6 mongrel dogs, a tandem conduit between the right ventricle and the pulmonary artery was implanted, consisting of a plain woven and a double-velour woven graft. Following explanation after 2, 4, and 6 months, superior healing properties of the double-velour woven prostheses could be assessed by microscopy, as represented by an increase of tissue ingrowth, as well as by a thin and densely adherent inner healing capsule. Double-velour woven grafts were implanted in 50 patients undergoing open heart surgery. All grafts were presealed with fibrin glue and no bleeding could be detected at the time of implantation, even under the adverse influence of full heparinization and extracorporeal circulation.

Histopathological evaluation of woven and knitted Dacron grafts for right ventricular conduits: a comparative experimental study.

Composite extracardiac conduits consisting of a low-porosity woven graft and a high-porosity knitted double-velour Dacron graft presealed with fibrin glue were implanted between the right ventricle and the pulmonary artery in 6 dogs under partial heparinization. Two grafts were explanted after 6 weeks, 2 after 12 weeks, and 2 after 6 months. The healing properties of both types of prosthesis were studied macroscopically, under light microscopy, and with scatter electron microscopy. Spontaneous peeling of both the inner and outer capsules of the graft occurred in 3 of 6 woven prostheses during transection. In the remaining 3, peeling could be easily induced by blunt dissection; this was impossible in the knitted grafts. Microscopically, in a comparison of the different weaves after identical time intervals, the inner capsule was noticeably thicker in woven than in knitted grafts. Transtitial ingrowth of fibroblastic tissue could be observed in knitted grafts after 6 weeks; only poor transmural tissue bridging was detectable in woven prostheses after 6 months. Neovascularization of the inner capsule was detectable earlier and was more advanced toward the luminal surface of highly porous grafts. In conclusion, knitted grafts in the position of extracardiac right ventricular conduits showed firmer attachment of both inner and outer capsules to the prosthetic material. Also, the inner capsule remained thinner and revealed a higher degree of neovascularization than in the woven Dacron grafts.

Fibrin adhesive: an important hemostatic adjunct in cardiovascular operations.

Fibrin adhesive was applied 413 times in a group of 340 patients undergoing extracorporeal circulation whenever conventional suturing appeared impossible, difficult, or dangerous, with a success rate of 95%. Fibrin-presealed woven or knitted fabric was inserted in 60 heparitized patients, 45 of whom underwent cardiac procedures. There was perfect sealing of the fabric in all but one instance. Fibrin gluing has become a routine method, reducing man-hours and blood loss and occasionally salvaging patients' lives. Fibrin-presealed knitted prostheses are expected to replace woven fabric because of its known poor healing qualities.

Evaluation of fibrin seal in animal experiments.

This paper presents experimental investigations to evaluate fibrin seal for bleeding control under systemic heparinization as well as some of the benefits and limits of fibrin-presealing vascular prostheses. Local hemostasis using fibrin seal plus collagen fleece was achieved in 3 standardized sources of bleeding produced in mongrel dogs under full heparinization. Water porosity was measured in 3 standard prosthetic materials of different porosity. It could be shown that all graft types investigated were sufficiently sealed up to a pressure of 600 mmHg. The influence of fibrinolysis on the stability of the fibrin network in vascular grafts was tested by in vitro experiments using urokinase incubation. While water permeability increased in fibrin-sealed fabric without aprotinin added, no fibrinolysis-induced leakage was observed in those exposed to aprotinin. Surface thrombogenicity of the fibrin-sealed grafts was higher than in blood-preclotted prostheses, if not rinsed with isotonic saline. After rinsing, thrombogenicity decreased below values obtained in grafts preclotted conventionally. Survival studies in animals show no difference between blood-preclotted and fibrin-presealed prostheses both 3 and 7 days after implantation.