[Microcirculation research in experimental surgery]

Microcirculatory effects of sildenafil in experimental testicular torsion in rats

PURPOSE

Investigate the short-term effect of sildenafil on microcirculation, especially the velocity, the pattern of the flow and the recruitment of the leukocyte in postcapillaries.

METHODS

In male Sprague-Dawley rats, the microcirculatory consequences of 60 min experimental testicular torsion, followed by 240 min of reperfusion, were examined. Using fluorescence intravital microscopy, changes in red blood cell velocity in post-capillary venules and rolling as well as adhesion of leukocytes in the postcapillary venules were examined before the torsion and every hour during the reperfusion period. Sildenafil was given 10 min prior to reperfusion (iv 0.7 mg/kg, n = 6), while control animals received saline vehicle (n = 5).

RESULTS

The characteristic flow motion disappeared in the affected testicular during the torsion. Red blood cell velocity values were dramatically decreased (by > 50%) and both rolling and adhesion of leukocytes increased during the reperfusion phase. Sildenafil treatment resulted in significantly higher red blood cell velocity values during the entire reperfusion period, but exerted only a temporary positive effect on the plost-ischaemic leukocyte-endothelial interactions.

CONCLUSIONS

Intraoperative administration of sildenafil during surgical detorsion may provide marked testicular microperfusion benefits, but failed to influence the overall leukocyte-driven microcirculatory inflammatory reactions.

[The development of plastic surgery: retrospective view of 80 years of "Der Chirurg" (The Surgeon)]

The often groundbreaking developments of new methods in Plastic Surgery have been published in the journal "Der Chirurg" (The Surgeon) ever since its foundation in 1928, when it was established as a journal dealing with all aspects of surgery and containing many innovations and developments. Historically this is also reflected in the establishment of Plastic Surgery initially as a subspecialty and later on as a specialty within the German Society for Surgery. The interdisciplinary character of modern reconstructive and oncological concepts, not only with other specialties but also within various surgical specialties, raises further challenges and leads to new developments in reconstruction, which will definitely induce an increasing amount of knowledge to the advantage of our patients. Scientific and clinical advances over the last 80 years give rise to the hope that similar success will be attained for reconstruction of traumatic and oncological defects and malformations or disfigurations in the future. Consolidated findings from regenerative medicine and tissue engineering will enrich the daily practice of surgical reconstruction.

Evaluation of hepatic microcirculation by in vivo microscopy

In vivo microscopy is an excellent technique for investigating the microcirculation and until recently the only one that allowed direct visualization. Rat liver has been widely studied, because microcirculatory disorders play a pivotal role in the pathogenesis of organ failure during hepatic ischemia, transplantation, hemorrhagic shock, endotoxemia, and sepsis. The state of the microcirculation is an important prognostic factor for the reestablishment of organ function after these injuries. This article introduces the most common procedures for in vivo microscopy of the rat liver, summarizes the available fluorescent dyes, and gives an overview of criteria for the expression and evaluation of microscopic findings. Particular emphasis is given to a description of the different parameters assessed by direct observation of hepatic microcirculation, such as perfusion rate, leukocyte-endothelium interactions, leukocyte velocities, and phagocytic activity. Examples of normal range values are given. This overview is intended to help those wanting to introduce this method into their research and who are embarking on intravital microscopy for the first time, and to enable them to decide which techniques are appropriate for answering special questions.