Tyrolean tensiometer: a new instrument for easy intraoperative tension measurement before vascular anastomosis

In reconstructive surgery microsurgical repair of dissected arteries sometimes has to be done under longitudinal tension. Guidelines to support an objective decision on whether tension associated with direct suture is acceptable or whether grafting is needed, do not exist. All experimental data found concerned the clinical outcome of a certain length defect treated in various animal models. The aim of this study was to show the feasibility of a new instrument for measuring the tension required to adapt arterial stumps, thereby allowing surgical outcome to be assessed before beginning anastomosis.

A modified tension spring balance was used to measure the force applied to the arterial stumps before knotting. Twenty-four rat femoral arteries were dissected, segments of up to 9mm were resected, and the tension needed for approximation was measured. These ex-vivo data were combined with clinical outcome data of previous animal trials.

The tension measured increased proportionally to the size of the arterial gap created. The correlation between tension and arterial gap was found to be almost linear. The average additional time required for tension measurement using the Tyrolean Tensiometer was 13 (+/-6) s.

High anastomotic tension may cause critical or even poor clinical outcome. None of the tension measurement methods described so far allow intraoperative measurement at a time when changes in strategy are still possible. The Tyrolean Tensiometer for the first time allows fast and reliable measurement of the tension acting on the first suture of an anastomosis.