When Harry Reich performed the first laparoscopically assisted vaginal hysterectomy in 1989, he advocated the use of sutures for control of the uterine vessels. Monopolar, bipolar, and laser instruments available at that time were inherently risky to use along the pelvic sidewall because of their potential for 1) considerable thermal energy spread beyond the area of treatment (bipolar, NG:YAG laser, monopolar) and 2) unreliable hemostasis (CO2 laser).
Minimally invasive surgical practice has driven meaningful advances in instrumentation and technique over the past 20 years. The constraints inherent in laparoscopic surgery, although somewhat mitigated by robotics, have generated a proliferation of technologies to obtain reliable hemostasis. Every device now on the market claims to “seal” vessels. In this article, I review the mechanism of action of these instruments and compare their strengths and weaknesses, based on high-quality scientific evidence.
Two studies highlight vessel ligation
Newcomb WL, Hope WW, Schmeizer TM, et al. Comparison of blood vessel sealing among new electrosurgical and ultrasonic devices. Surg Endosc. 2009;23:90–96.
Lamberton GR, Hsi RS, Jin DH, et al. Prospective comparison of four laparoscopic vessel ligation devices. J Endourol. 2008;22:2307–2312.
Many energy-delivery systems are available for the gynecologic surgeon; any of them can be used effectively and safely under most circumstances. Before we can make an informed choice about which system is best for our own practice, however, we need to be aware of the strengths and limitations of the systems overall ( TABLE ).
These two studies focus on the following devices:
- Gyrus PK Tissue Management System, PKS Cutting Forceps, and Plasma Trissector (all from Gyrus Medical). These are bipolar electrosurgical devices designed to deliver high current and very low voltage to tissue. Tissue impedance is continuously monitored between the jaws of the instrument, and energy delivery is adjusted accordingly. These systems deliver electrosurgical energy through a series of rapid pulses, thereby allowing the tissue to cool briefly and limiting the heating of adjacent tissue. Protein in the vessel walls is denatured and forms a coagulum, which occludes the lumen.
- Harmonic Scalpel (Ethicon EndoSurgery). This device uses a high-frequency ultrasonic transducer (55,000 cycles/second) to create mechanical vibration of one of the two jaws. The device can be used to vaporize tissue (cut) or achieve hemostasis by coagulation. As with the other devices, protein is denatured and vessels are occluded by formation of a coagulum.
- Ligamax 5 Endoscopic Multiple Clip Applier (Ethicon). This device is a sterile, single-patient-use, 5-mm, endoscopic, multiple-clip applicator that delivers 15 medium or large titanium clips that close to 8.8 mm, the same clip size as the 10-mm applicator. Ligamax 5 has long, thin angled jaws (8.4 mm) that extend beyond vessels and ducts to improve visibility. It includes a long, 33-cm shaft for additional reach, and an anti-clip drop-ratchet mechanism for control over clip closure.
- EnSeal Tissue Sealing and Hemostasis System and EnSeal PTC (SurgRx). EnSeal utilizes nanotechnology to control the energy at the electrode–tissue interface. The jaws contain a temperature-sensitive matrix with embedded conductive carbon spherules designed to “sense” tissue characteristics. It uses extremely high jaw compression to create uniform tissue effects. It does not require a dedicated electrosurgical unit for use; an adapter can be purchased that permits use with most generators.
- LigaSure V (Valleylab). LigaSure is a bipolar electrosurgical device designed to deliver high current and very low voltage to tissue. It monitors tissue impedance between the jaws of the instrument and continuously adjusts the delivery of energy.
TABLE
Rating vessel-sealing devices: 5 measures of success
| Device | Safety: Minimal thermal spread | Reliability: Efficacy on vessels ≤7 mm | Efficiency: Treatment time | Consistency: Independent of user | Utility: Multiple uses |
|---|---|---|---|---|---|
| Harmonic Scalpel | Excellent | Poor | Excellent | Poor | Excellent |
| Gyrus PK | Poor | Poor | Excellent | Fair | Fair |
| LigaSure V | Good | Excellent | Good | Excellent | Fair |
| EnSeal | Fair | Excellent | Poor | Excellent | Poor |
| These ratings were devised by the author based on data from independent studies in living tissue models. | |||||
FIGURE How energy-based vessel-sealing works
(A) When the carotid artery of an animal model was sealed using a standard bipolar forceps, the lumen remained open and a proximal thrombus developed. (B) When LigaSure was used, the artery was fused and the lumen obliterated with one 5-second application. (C and D) When a renal artery was sealed with LigaSure, the lumen of the vessel walls fused completely.
What the studies found
Newcomb and associates compared blood-vessel-sealing ability of the following devices:
- Gyrus 5-mm PKS Cutting Forceps
- Gyrus Plasma Trissector
- Harmonic Scalpel
- EnSeal Tissue Sealing and Hemostasis System
- LigaSure V, using the LigaSure Generator (Valleylab)
- LigaSure V, using the Force Triad Generator (Valleylab)
- Ligamax 5 Endoscopic Multiple Clip Applier.