End-to-side vascular anastomosis: a study of technical considerations in the rat

Cerebral revascularization

During the last 10 years, there has been a revival of interest in cerebral revascularization procedures. Not only have significant progressions in surgical techniques been published, the use of more advanced diagnostic methods has led to a widening of the indications for cerebral bypass surgery. The purpose of this review is to outline the current techniques for extracranial-to-intracranial (EC/IC) and intracranial-to-intracranial (IC/IC) bypass surgery, as well as to identify the current indications for revascularization procedures based on the available literature. The excimer laser-assisted non-occlusive anastomosis (ELANA) technique is described in more detail because we think that this technique almost completely eliminates the risk of cerebral ischemia due to the temporary vessel occlusion which is currently used in conventional anastomosis techniques.

Neointimal formation at the sites of anastomosis of the internal thoracic artery grafts after coronary artery bypass grafting in human subjects: an immunohistochemical analysis

OBJECTIVES

The aim of this study was to evaluate the cellular composition and cell proliferative activity of neointimal tissue in human internal thoracic artery grafts and to characterize the differentiation state of neointimal smooth muscle cells at early stages after coronary artery bypass grafting.

METHODS

The anastomotic sites and body segments of 7 patent grafts were obtained at autopsy from 7 patients who died within 92 days after operation. Serial sections were examined by immunohistochemical techniques to identify macrophages, endothelial cells, smooth muscle cell phenotype, and proliferating cells. For the identification of the cell types that show cell proliferative activity, immunodouble staining was also performed.

RESULTS

In all body segments the luminal surface was completely covered by endothelial cells, and no areas showed thrombus formation or neointimal proliferation after grafting. In contrast, in the anastomotic segments endothelial denudation and focal disruption of the internal elastic lamina with adherence of fibrin-platelet thrombus and infiltration of macrophages were observed in the earliest stage after grafting. At these sites of injury, early neointimal tissue response had occurred, and cell proliferative activity was detected in macrophages and dedifferentiated smooth muscle cells. During the evolution of neointimal thickening, redifferentiation of neointimal smooth muscle cells occurred associated with the decline in proliferative activity.

CONCLUSIONS

These observations strongly support the concept that excessive neointimal proliferation, which may occur at the site of anastomosis because of extensive damage to the arterial wall, could be one of the possible causes of failure of the internal thoracic artery graft in human beings.

Use of small-caliber polytetrafluoroethylene (Gore-Tex) grafts in microsurgical training

We present the use of polytetrafluoroethylene (PTFE) graft material as a microsurgical training model that better simulates live vessel repairs. PTFE grafts have mechanical advantages over polyethylene or silicone tubing in that they better mimic the "feel" of an arterial vessel wall, thus allowing the student to perfect counterpressor maneuvers before attempting live vessel repairs. Saving the PTFE "repairs" for later comparison and study provides the student with positive feedback that is not possible with living models. This cost-effective model has helped to shorten our directed teaching program and has reduced the use of laboratory animals.

Extraintracranial anastomosis performed by means of biological gluing materials: experimental and clinical study

A new surgical technique of extraintracranial anastomosis (EIA) is reported. End-to-side microvascular anastomosis is performed by applying four crossed-fixing sutures and by mantling a hemostatic sponge muff (eg, Spongostan) impregnated with fibrinogen-thrombin glue. Histopathological studies of microvascular anastomosis in animals and clinical results of 70 EIA operations showed that this surgical technique of anastomosis has certain advantages, namely that it reduces the number of sutures needed, is less traumatic to the vascular wall, ensures elastic vascular junction, and the glue and Spongostan used possess high biological inertness that provides a better physiological connection of vessels than conventional suturing. The highly hermetic vascular junction and absence of blood flow at the anastomosis site are achieved without additional suturing. The duration of the operation is significantly reduced. A full EIA function sets in comparatively early.