In search of the autologous clip: a case for experimental standardization.

BACKGROUND: In an effort to enable faster and, at times, more challenging surgeries without compromising patient or physician safety, medical device manufacturers have created myriad solutions to vascular ligation through the development of novel tools. The speed of development, FDA approval, and dissemination of these devices into the hands of surgeons often outpaces the ability of investigators to critically evaluate comparative effectiveness of these devices. DATABASE: The Medline database was searched for energy-based vessel ligation devices. To remove any perception bias against non-Covidien instruments, critical review was applied only to the devices manufactured by our company. CONCLUSIONS: We report on the variability present in published results and offer vital metrics for future studies. Standardized testing and reporting for measures of safety and efficacy of these surgical instruments awaits definition from a consensus group.

Operative time and other outcomes of the electrothermal bipolar vessel sealing system (LigaSure) versus other methods for surgical hemostasis: a meta-analysis.

A meta-analysis was performed of 29 prospective, randomized trials (published January 1, 2000, to August 14, 2007) comparing an electrothermal bipolar vessel sealing system (EBVS-LigaSure, Covidien) (total n = 1107 patients) with either clamping with suture ligation/ electrocauterization (n = 1079 patients) or ultrasonic energy (eg, Harmonic Scalpel, Johnson & Johnson). Hemorrhoidectomy (12 articles), hysterectomy (4 articles), and thyroidectomy (3 articles) were the most common procedures. For 15 of 26 studies reporting standard deviations, the normalized mean operative time reduction for EBVS equaled 28% (95% confidence interval [CI] 18%-39%, P < .0001) compared with conventional surgical hemostasis. Operative time was reduced with EBVS in 24 of 26 studies (P < .0001). EBVS was associated with 43 mL (95% CI 14-73 mL, P = .0021) less blood loss, fewer complications (odds ratio 0.66, 95% CI 0.47-0.92, P = .02), and mean reduction in postoperative pain of 2.8 units (95% CI 1.5-4.1, P < .0001). Five studies used ultrasonic energy as the comparator, but none reported standard deviation so data could not be pooled.

Superiority of using bipolar radiofrequency energy for internal mammary artery harvesting.

PURPOSE: The purpose of this study was to observe the acute effects of harvesting the porcine internal mammary artery using a novel bipolar (BP) radiofrequency energy device. DESCRIPTION: The internal mammary artery from 16 porcine subjects was harvested using monopolar electrosurgery, BP electrosurgery, ultrasonic coagulation, and mechanical dissection with clips. Segments were evaluated with respect to endothelial function and integrity and the strength of side-branch sealing. EVALUATION: Adenosine triphosphate-induced relaxation was greatest with internal mammary artery segments harvested by bipolar electrosurgery in comparison with monopolar electrosurgery (p = 0.0271), ultrasonic coagulation in comparison with monopolar electrosurgery (p = 0.0047), and mechanical clipping in comparison with monopolar electrosurgery (p = 0.0381). The standard error of the mean failed to demonstrate any significant difference in epithelial disruption among the four treatment groups. Clips and bipolar electrosurgery exhibited the most secure ligations with burst pressures exceeding 350 mm Hg. CONCLUSIONS: Internal mammary artery segments harvested using a novel BP electrosurgery retained a greater degree of endothelial function when compared with monopolar electrosurgery and ultrasonic coagulation. Side-branch sealing with BP electrosurgery was as secure as mechanical clips.

Method for creating ideal tissue fusion in soft-tissue structures using radio frequency (RF) energy.

Bipolar radiofrequency (RF) energy can successfully seal vascular structures up to 7 mm by fusing collagen and elastin in the lumen. Valleylab has created a system to expand this technology beyond vessel sealing with the development of a closed-loop, feedback-control RF generator that closely monitors tissue fusion. This generator, operating with a loop time of approximately 250 micros, continuously adjusts energy output, creating optimized soft-tissue fusion through structural protein amalgamation. In the first study, RF energy was applied to canine lung using the new-generation generator and lung-prototype device. A lobectomy was completed, sealing the lobar bronchus, parenchyma, and pulmonary vasculature. Chronic performance of the seals was evaluated at necropsy on postoperative days 7 and 14. In a second study, RF energy was applied to porcine small intestine using the same closed-loop generator and anastomosis prototype device. Acute tissue fusion was assessed qualitatively for hemostasis and seal quality. Terminal tissue evaluation was completed on postoperative day 7 and analyzed histopathologically. Histopathology confirmed acute and chronic tissue fusion in both the lung and intestine. Normal pathological healing was substantiated by angiogenesis, granulation, and proliferation of fibroblasts. Preliminary studies using canine lung and porcine small intestine demonstrate the potential of this closed-loop generator for soft-tissue amalgamation. Advanced monitoring capabilities make this fusion system applicable in many soft-tissue structures with adequate collagen and elastin. Further investigation of potential surgical applications needs to be completed.

Comparison of healing process following ligation with sutures and bipolar vessel sealing.

Local hemostasis is critical for successful surgical intervention and may be accomplished with a variety of techniques ranging from direct pressure to lasers. Critical assessment of the clinical situation is required to determine the appropriate technology necessary to achieve effective hemostasis. As a general rule, ligatures remain the mainstay for effecting hemostasis in all but the smallest isolated vessels. Although ligatures have been in use since the first century AD, both the applications as well as their sophistication have increased dramatically. As sutures are foreign material to the human body, tissue reaction is unavoidable. This response may be mitigated, but not eliminated completely, through the use of non-absorbable sutures. The body's inflammatory response triggers a complex cascade of cellular and biochemical events that lead to fibrinogenesis and coagulation. This process, in turn, results in an increased deposition of collagen that may result in formation of adhesions.