Abstract
Introduction
The reduction of intraoperative blood loss during total knee arthroplasty (TKA) and total hip arthroplasty (THA) and even organ resection is an important factor for surgeons as well as the patient. In order to cauterize blood vessels to stop bleeding diathermy is commonly used and involves the use of high frequency and induces localized tissue damage and burning. Saline-coupled bipolar sealing RFE technology however has been shown to reduce tissue carbonization, however the dosage effects of RFE are not well known for both bone and soft tissue. This study examined sealing progression of blood vessels using a range of energy levels of saline-coupled bipolar RFE on bone and various soft tissues in a non-survival animal study.
Materials and Methods
Following institutional ethical approval, three mature sheep were used to examine the cancellous bone of the femoral trochlear groove and soft tissue (liver, kidney, lung, pancreas and mesentry peritoneum) subjected to the following treatment regime varying by watts and time: (1) untreated control, (2) 50 W for 1 sec, 2 sec, 3 sec and 5 sec, (3) 140 W for 1 sec, 2 sec, 3 sec and 5 sec and (4) 170 W for 1 sec, 2 sec, 3 sec and 5 sec. The Aquamantys™ System Generator and hand piece (Salient Surgical Technologies, Inc, Portsmouth, NH) coupled to a saline (0.9% NaCl) drip was used to apply RFE to the various tissues. Two clinical diathermy settings were used as controls. Tissues were immediately harvested, fixed in 10% buffered formalin and prepared for routine paraffin histology. Stained sections were evaluated in a blinded fashion for the acute in vivo response.
Result
Soft tissue histology treated with the Aquamantys System revealed varying degrees of coagulation and blood vessel sealing. Initial observations were indicative of hemostasis. Once RFE and saline were applied to the tissues, the blood vessels constricted and platelets were observed along the blood vessels to provide a seal to cover the break in the vessel wall.
No smoke or char formation was evident when this system was placed in contact with the tissues. Higher frequency revealed an increased cluster of platelets along the vessel wall.
Saline-coupled bipolar RFE application on bone demonstrated blood vessel sealing and clumping of bone marrow. With increased frequency and time red blood cells clumped together however the most significant observation was that the surrounding bone remained normal and no damage was evident. Diathermy however demonstrated a complete disruption of the collagen fibres
Conclusions
Saline-coupled bipolar RFE can provide many clinical benefits not just during orthopaedic reconstruction but also during spine surgery and clinical oncology. The use of high frequencies for longer periods of time enables complete sealing of blood vessels without damage to the tissue or bone.
