Singular case of tardive anastomotic disjunction in a Dacron R vascular graft.

We investigated a case of anastomotic disjunction of the termino-lateral insertion of a bifurcate aortic graft in the right external iliac artery. The graft in woven Dacron R n. 19, was implanted in 1977 and the left femoral insertion became infected shortly after surgery. The infection was treated according to standard procedures with removal of the infected branch, reconstruction with the transobturatory by-pass and antibiotics. For antibiotic treatment of local and general sepsis the approach was completely new as regards dose regimen and duration. In 1993 a pseudoaneurysm developed through weakening of the right iliac anastomosis. In view of the anamnesis we were surprised to find that the origin was of a mechanical nature.

Anastomotic disjunction in long-term patent vascular synthetic grafts in Dacron.

This study follows the recently published paper on the in vivo behaviour of patent Dacron vascular prostheses and focuses in particular on anastomotic disjunction. The question of the evolution of anastomoses was tackled by examining its three basic components: prosthetic tissue, suture thread and arterial wall. The authors' observations were based on material taken from reoperations performed between 7 and 18 years after the first graft. These data enable the authors to affirm that the prosthesis undergoes a general physical and chemical deterioration which varies in intensity according to the type of weaving. On the contrary, in the anastomotic zone this phenomenon is not intense enough to jeopardize the anchorage of the suture thread since the original weft does not show any loss of compactness. In spite of surface morphological deterioration of various intensity, the suture threads maintain satisfactory mechanical properties and structural integrity. The artery wall in the anastomotic zone shows a massive degeneration in terms of its true anatomic structure responsible for the rupture of the suture rima. On the basis of these results the authors conclude that this phenomenon represents the "Achilles' heel" of anastomotic junction.

Are synthetic prostheses really inert? Preliminary results of a study on the biocompatibility of Dacron vascular prostheses and Silicone skin expanders.

This study investigates the histo-pathologic reactions induced by implant of prostheses in Dacron knitted double velour and skin expanders in Silicone elastomers. Particular attention was paid to the effect of these reactions on the tissue itself. In the case of vascular prostheses it was found that fibrous connective tissue tended to accumulate in and around the prosthesis. We also observed widespread lymphohistiocytic infiltration and occasional plasmacytes. Numerous foreign body granulomas were found to be grouped around the filaments of plastic material. The prosthesis itself seemed to be composed of filaments of different calibre, fragmented into particles of varying size. Thus the structure of the prosthesis was modified and discontinued along its whole length. A similar granulomatous inflammatory reaction developed in the case of the skin expander, probably due to the leakage of particles of plastic material through the expander wall, which however did not seem to be affected by the tissue reaction. The findings indicate the need for more detailed research into the material used for prostheses, aimed at determining what modifications the tissues can produce in the synthetic material. Also, it is necessary to follow a multidisciplinary approach which takes into consideration the data available from the chemistry of polymers, fluid mechanics and cell biology.

[E. Malan's diversion syndrome. Reflections after twenty years' experience]. / Le sindromi da diversione di E. Malan. Riflessioni dopo vent'anni di esperienza.

A personal series of 131 cases of diversion syndrome of the upper and lower extremities is reviewed. 3 cases observed in a study of 100 infants are also reported. Only 12 of the 131 cases are presented as true diversion syndromes and the possible congenital origin is recognised. It is pointed out that the haemodynamic event does not have the significance of a haemometrokinetic phenomenon but of a true diversion capable of activation to the point of attaining the appearance of active localised a-v angiodysplasias.

[Development of the E. Malan diversion syndrome]. / Evoluzione delle sindromi da diversione di E. Malan.

Three cases of pure diversion syndrome evolution are reported, by "pure" being meant those characterised by the constant presence of the diversion phenomenon. The increase in the latter may lead these syndromes to be mistaken for active localised a.v.f. pictures. Some notes on treatment are added.

[Subrenal aortic insertion of a synthetic prosthesis]. / L'inserzione aortica sottorenale della protesi sintetica.

The problem of "high" proximal insertion at the inferior mesenteric of the synthetic prosthesis in obstructive aorto-iliaco-femoral atherosclerotic pathology is considered. In the light of 3 cases of pseudoaneurysm of the aortic wall, occurring 10, 9 and 7 years after the operation, and hence of problems that presented for the restoration of arterial continuity, distal implantation at the inferior mesenteric is preferred today with a generally end-to-end anastomosis after "cleaning" of the aorta upstream. Disobliteration is therefore avoided. The inferior mesenteric is kept patent if possible by disobliterating it and reimplanting it on the prosthesis, depending of the situation.

[Prosthesis of knitted dacron velour: an unusual case of late complications]. / Protesi in knitted dacron velour: un caso non comune di complicanze tardive.

A case of aneurysmal dilatation of the right branch of a knitted dacron velour prosthesis and then of pseudoaneurysm from its termino-lateral aortic insertion 9 and 10 years after implantation is reported. Histological examination carried out on the prosthesis caused great perplexity in both cases as there were evident signs of fibre fragmentation by polynucleate elements.

[Morphologic aspects of late degradation in arterial prosthetic reconstruction]. / Aspetti morfologici di degradazione tardiva delle ricostruzioni protesiche arteriose.

Fragments of synthetic prostheses in knitted Dacron velour implanted years previously have been examined. Macrophages were found which fragment elements of the prostheses. It is concluded that synthetic knitted velour prostheses are biodegradable.

[Are synthetic prostheses really inert?]. / Sono le protesi sintetiche veramente inerti?

Five cases of long-term complications of a homogeneous series of 78 aorto-iliac-femoral by-passes in knitted Dacron velour observed between 1976 and 1988 are reported. The cases were aneurysm of a prosthetic branch and pseudoaneurysms of aortic and femoral anastomoses. The paper concerns not so much the presentation of the causes, recognised by most Authors, that might have determined the ongoing pathology as the observation of a histologic situation not previously described: namely the presence of macrophages which attack Dacron fibres and fragment them.

[Biodegradation of dacron vascular prostheses. Physico-chemical, histological, morphometric and ultrastructural study]. / Biodegradazione delle protesi vascolari in Dacron. Studio chimico-fisico, istologico, morfometrico ed ultrastrutturale.

The paper deals with study of long-term stability as far as concerns Dacron vascular prostheses in woven and knitted double velour. Among our vascular prostheses case-reports, we evaluated three of them explanted after 11, 12, 20 years; all of the prostheses were patent. Chemical-physical, histopathological and ultrastructural analysis have been carried on in order to evaluate in vivo ageing of the examined prostheses. The results all indicate strong alterations of the original properties related to double velour of knitted prostheses and weak alterations of woven one.

[The correction of malformations of the internal carotid. A technical note]. / Correzione di malformazioni della carotide interna. Nota di tecnica.

A technical variation for the treatment of certain internal carotid malformations such as lengthening, bending and volvulus is reported. The variation consists in the creation of a "neobifurcation" that offers haemodynamic conditions very close to those of anatomical bifurcation.

[Vascular abnormalities of the limbs. Some observations on the classification]. / Malformazioni vascolari degli arti. Alcune osservazioni sulla classificazione.

In the light of the most recent non-invasive and invasive diagnostic findings, E. Malan's classification of 1974 is reproposed. This introduces the concept of prevalence to Malan-Puglianisi's previous classification of 1964. A common denominator is proposed for all vascular malformations, not only those involving the extremities, to simplify this pathology still further: the presence or otherwise of the diversion phenomenon.

[Stripping of the internal and external saphenous veins in a day hospital]. / Lo stripping della safena interna, della esterna in day-hospital.

The procedure used to carry out internal and external saphenectomy operations in a day-hospital is described. The choice of cases is conditioned by phlebographic examination, and by talks between patients, anaesthetist and surgeon. Anaesthesia is local and general at the time of stripping. The technique is the classical one of saphenectomy according to the school of Edmondo Malan, with some variations.

[An unusual case of atherosclerotic aneurysm of the trunk of the superior mesenteric artery, successfully treated with surgery]. / Di un caso non comune di aneurisma aterosclerotico del tronco dell'arteria mesenterica superiore, operato con successo.

A case of atherosclerotic aneurysm of the superior mesenteric artery is reported. This was located about 15 cm from its origin and immediately distal to the middle colic artery in a patient who had been operated on 4 years previously with aorto-iliac substitution for aneurysm of the same nature with ligature and section of the inferior mesenteric artery at the origin. Interruption of the latter created further technical problems solved with a serie of anastomoses that permitted the introduction of a good direct flow from the superior mesenteric respectively to the right colic and into an ileal branch which became a bridge or, rather, a "new mesenteric" assuring excellent pulsed flow into the underlying ileal branches, one of which anastomized at the ileocolic. This enabled direct, valid, pulsed flow to be resumed.

[Changes in the plasma magnesium content in patients subjected to cardiopulmonary bypass]. / Le variazioni di contenuto plasmatico di magnesio in pazienti sottoposti a by-pass cardio-polmonare

Changes in plasma magnesium content in 17 patients operated in extracorporeal circulation are reported. Values were low at the end of the operation, but rose at the end of the first day to achieve spontaneous resolution of the condition within 3 days. No close relationship between such loss and immediate postoperative arrhythmia could be discerned. Attention is, however, drawn to 3 cases in which ventricular fibrillation was not resolved until electric shock treatment was preceded by the administration of magnesium sulphate.