To knot or not to knot? Sutureless haemostasis compared to the surgeon's knot

The aim of this study was to carry out an independent evaluation of the efficacy and security of a number of vessel ligation devices and ligatures.

A vascular ligation model was devised using fresh, ex vivo porcine internal carotid arteries of varying external diameters. Coloured normal saline was infused via a pressure/monitor device through the artery. The end lumen was occluded by five different techniques: (i) braided suture in a surgeon's knot; (ii) a monofilament suture in a granny knot; (iii) a metallic clip (Ligaclip, Johnson and Johnson); (iv) a bipolar diathermy system (Ligasure, ValleyLab); and (v) an ultrasonically activated scalpel (Harmonic Scalpel, Johnson and Johnson). The vessels were subjected to supraphysiological pressures. Loss of haemostasis was evident by leakage of coloured perfusion fluid.

Secure haemostasis was obtained with all the techniques in all vessels below 5 mm in diameter. In vessels over 5 mm, secure haemostasis was obtained with all modalities except harmonic scalpel. With the harmonic scalpel, leaks occurred in 3/27 (11%) vessels between 5-6 mm and 3/5 (60%) vessels over 6 mm, confirming the manufacturer's instructions.

In this first, independent, randomised study comparing vessel ligation devices and ligatures, the manufacturer's claims for each of the haemostatic methods were accurate. We find that all the modalities tested perform as well as the traditional surgeon's knot in vessels of 5 mm and below.