Advanced Energy Systems for Laparoscopic Gynecology Procedures

Available at www.obgmanagement.com s u pp l ement to

This supplement is supported by a grant from Ethicon Endo-Surgery, Inc., and has been peer reviewed by the editors of OBG Management.

November 2009

Advanced energy systems for laparoscopic gynecology procedures Multifunctional technology yields reliable outcomes, enhances patient safety, and increases procedure efficiency

Chair Dr Brill: Probably no surgical instrument defines the gynecolo- gist more than the Kleppinger forceps, the first bipolar device Andrew I. Brill, MD Director of Minimally Invasive used for tubal ligation. It remains an important part of our ar- Gynecology mamentarium despite thermal spread, smoke, char, tissue stick- California Pacific Medical Center ing, and inconsistent hemostasis,1-5 shortcomings that have led San Francisco, California to the development of newer bipolar electrosurgical devices— the LigaSure™ Vessel Sealing System, PlasmaKinetic (PK) plat- Faculty form, and ENSEAL®. These energy-based surgical devices offer John D. Bertrand, MD Director added functionality—coagulation and cutting in a single instru- Minimally Invasive Surgery ment—as well as increased efficiency. These instruments offer Texas Health Dallas specific features that appeal to gynecologic surgeons who have Walnut Hill OB/GYN Associates Dallas, Texas different needs and preferences. Ultrasonic energy technology has also advanced significantly, with instruments such as the Steven D. McCarus, MD Harmonic ACE®, which both cuts and coagulates at the point Chief, Division of Gynecologic Surgery of impact for use in soft-tissue incisions and transections. Director, The Center for Despite our collective surgical experience, the comparative Pelvic Health Florida Hospital Cenebration strengths and weaknesses of these devices have yet to be clearly Orlando, Florida established in an unbiased and reproducible fashion. Ex vivo studies have attempted to quantify the comparative effective- Disclosures ness of these devices with wide variances in results, primarily Dr Bertrand reports that he serves as a consultant to Ethicon Endo-Surgery & Women’s Health and American based on the use of non-standardized protocols. We must await Medical Systems. He serves on the speakers bureaus of the results of well-designed in vivo studies that compare effi- Johnson & Johnson, Ethicon Endo-Surgery & Women’s Health, American Medical Systems, and Olympus. He ciency, sealing time, lateral thermal spread, smoke product, and also has a financial relationship with Warner Chilcott. burst pressures to define their relative use for ligating and cut- Dr Brill reports that he serves as a consultant to and is on the speakers bureaus for Ethicon, Karl Storz, and ting vascular tissue. Conceptus. Dr McCarus serves as a consultant to Ethicon New technologies expand range of procedures Endo-Surgery, Inc. Dr Brill: As teachers, do you meet physicians who see little rea- son to use newer devices, given that they have had no problems with conventional bipolar devices? Dr McCarus: Yes. If a clinician says, “I haven’t had any problems

Figure 1 Figure 2 Sealing by proximal thrombus Sealing with electrosurgery

The Kleppinger forceps create hemostasis by This seal, created by ENSEAL®, is produced through low contraction of the vessel walls. temperature, high pressure, and pulsed energy.

with the equipment I use,” I ask what advance. I evaluate its ergonomics and type of surgery he performs. The scope its cost and, most importantly, whether of electrosurgery extends beyond tubal it is safer than other devices. Patient safety ligation; new tools enable us to perform Dr McCarus: Another consideration is, has fueled many procedures and manage anatomic does the instrument provide dependable advances in difficulties with increased patient safety. and predictable vessel hemostasis? In- instrumentation. Dr Bertrand: The Kleppinger forceps, a traoperative bleeding is our number one wonderful device, has safety issues: lat- practical concern. Given operating room eral spread and heat generation.6 Phy- scheduling issues and costs, I look for sicians who reject change probably do versatile and multifunctional equipment not work on involved cases that bring that will shorten procedure times. us close to the ureter, bowel, or bladder. Dr Brill: I am very concerned about the Newer devices allow us to perform pro- multifunctionality of a new device for cedures in proximity to these vital struc- tissue dissection. I assess any new en- tures and organs in a safer fashion. ergy-based device not just for thermal Dr Brill: True: Based on fundamental bio- characteristics, but for ease of use, abil- physics of electrosurgery in living tissue, ity to lift, grasp, and dissect tissue, and voltage is the primary cause of thermal its performance in heterogeneous desic- damage. Importantly, newer bipolar li- cated, fatty, or vascular tissue. gating devices deliver low-voltage elec- Dr Bertrand: We should not forget the tricity to lessen thermal damage and cavitational effect of Harmonic® instru- result in more predictable spread. New mentation, in which steam accomplish- devices also “communicate” with the es the natural plane dissection by quick tissue—based on changes in tissue resis- and localized action, minimizing lateral tance called impedance—to deliver pre- thermal energy. cisely the amount of energy necessary to Dr Brill: When a surgeon understands the accomplish the task.7 fundamental principles of energy-based surgery—and the relative strengths and Considerations in adopting weaknesses of any device in this con- new technology text—it is possible to take the device to Dr Brill: How do you decide if a new de- a higher level of performance, achieving vice fits into your armamentarium? otherwise impossible tissue effects. Some Dr Bertrand: First I determine whether devices, designed simply to perform liga- the instrument marks a true scientific tions, can be modified to desiccate and

S November 2009 / Supplement to OBG Management Instrumentation to expand surgical options

here are 3 bipolar platforms that utilize low constant voltage, pulsed current, and Timpedance feedback, along with a paired ligating-cutting device. By historic sequence, the LigaSure Vessel Sealing Device (Covidien, Boulder, CO) applies a high coaptive pressure during the generation of tissue temperatures under 100ºC; hydrogen cross-links are first ruptured and then re-natured, resulting in a vascular seal that has high tensile strength. The second instrument, the PlasmaKinetic Cutting Forceps (Gyrus/ACMI/Olympus, Minneapolis, MN), lacks the compressive pressure needed to create a true vessel seal but provides efficient coagulation with visibly pulsed energy that is moderated by impedance feedback. The third device, the EnSeal Laparoscopic Vessel Fusion System (EES, Cincinnati, OH) utilizes temperature-sensitive polymeric material (PTC) embedded with nanometer- sized spheres of carbon that automatically controls a locally regulated current, regulating temperatures at about 100º C. Desiccation with this device is facilitated by advancing an innovative “I-Blade” that provides extremely high pressure along the length of the jaw to both cut and squeeze the tissue bundle, eliminating tissue water and steam. Using the dynamic tissue effects of mechanical energy, ultrasonic blades, and shears, tissue effects from ultrasonic energy using the Harmonic Scalpel (EES, Cincinnati, OH) are actuated by a titanium blade of variable excursion that vibrates nearly 55,500 Hz/second from Durable an in-line piezoelectric crystal housed in the hand piece of the device. The high frequency vessel seals vibration in tissue causes a low temperature protein denaturation by rupturing the hydrogen can be obtained bonds of tissue proteins. Tissue cutting from cavitational fragmentation naturally evolves from the mechanical vibration and percussive effects of steam that emanates through the tissue without parenchyma. Differing from the volumetric thermal tissue effects during electrosurgery, lateral significant thermal damage with ultrasonic energy is limited by the linear nature of energy propagation through the tip of the blade. thermal change to tissue. Brill AI. Energy systems for operative laparoscopy. Am J Assoc Gynecol Laparosc. 1998;5:333-349. Brill AI. Bipolar electrosurgery: convention and innovation. Clin Obstet Gynecol. 2008;51:153-158. vaporize tissue. Do you agree? each device, with its unique combination Dr McCarus: Most gynecologic surgeons of software-driven energy delivery mod- don’t understand the principles of energy erated by the changing resistance of tis- and current flow through the path of sue as it is progressively desiccated. The least resistance. You’ve championed the Gyrus is the closest cousin to the Klep- term “the cognitive surgeon” to describe pinger and therefore the most intuitive individuals who understand and control of these new devices for the gynecologic energy’s effect on tissue and thereby reg- surgeon to use. LigaSure™ provides an ulate the procedure. Our residents and automated click and play solution for li- fellows must learn not just to activate gating vascular tissue. More recently, the an energy source to desiccate or char ENSEAL® also provides true vessel seal- tissue. They need to understand the ef- ing and transection with a uniquely so- fects on the tissue and be cognizant of phisticated combination of technological the ureter, bladder, and rectum, and how advances. Harmonic® energy, of course, to prevent unwanted energy from reach- is mechanical versus electrical energy, ing those structures. We have an exciting and is not regulated through impedance. opportunity to teach these principles and to bring new technologies into our arma- Is desiccation essential mentarium. for durable seal? Dr Brill: It is equally important to cogni- Dr McCarus: Colleagues say they like to tively appreciate the technical nuances of desiccate, to see charring and scarring www.obgmanagement.com Supplement to OBG Management / November 2009 S Advanced Energy systems for laparoscopic gynecology procedures

inanimate models? Evaluating New Dr McCarus: Certainly. And then we Energy Devices move on to animate models in labora- • Reliability tory sessions. But real learning occurs • Efficiency when you’re under the supervision of a • Ergonomics proctor or attending at table side. • Handedness Dr Bertrand: Again, surgeons must un- • Response to variable tissue content derstand energy. Otherwise, they may • Smoke production feel comfortable only with complete des- • Capacity to dissect iccation, characterized by a lot of smoke, • Tissue sticking char, and heat. • Tissue color Dr Brill: Yes, when we lower the voltage • Cost and decrease the amount of energy, we • Degree of innovation have to be more aware of our surgical technique to ensure durable seals. Suc- form on tissue. With new technology, do cess depends on best practices and phy- we really need to see desiccated tissue? sician awareness of the strengths and When we lower Dr Brill: At one time that preference may weaknesses of each energy modality. the voltage and have been merited. Using Kleppinger As teachers, do you start your learners decrease the forceps with a standard generator was with the same device regardless of the amount of unreliable and inconsistent. This modal- procedure? energy, we must ity does not truly seal a blood vessel but, Dr McCarus: I present all instruments be more aware instead, provides hemostasis through and ensure that students understand the of our surgical contraction of the vessel walls and the strengths and weaknesses of each. I leave technique. formation of a proximal thrombus (Fig- it up to them to decide which instrument ure 1). General surgeons, for instance, works best in their hands. have regarded this as a completely un- Dr Bertrand: I evaluate the expertise of tenable outcome in the context of high my student and also consider the proce- pulse-pressure vessels nearer to the heart. dure. Gyrus PK Cutting Forceps are suit- However, new bipolar technology seals able for surgeons who wish to move on blood vessels to withstand high systolic to more advanced technology and have pressure. As a result, general surgeons experience using the Kleppinger device. have become comfortable with the use of It is closest to a Kleppinger in terms of these devices. The durable vascular seal how it works. The surgeon grabs the created by newer bipolar electrosurgi- tissue and then coagulates it before cut- cal devices does not cause significantly ting with the centrally set mechanical visible thermal changes. The intricate blade. For an adnexa, I typically select an combination of low temperature, high ENSEAL® device. Among other features, pressure, and pulsed energy complete I use this technology because it regulates the sealing. Consequently, there is mini- temperature production within the jaws mal plume, carbon formation, and tissue of the instrument. By not allowing the sticking (Figure 2). temperatures to exceed ~100°C, I get not only reliable hemostasis, but a noticeable Best practices for training reduction in char and tissue stickiness. Dr Brill: This method of sealing, with its Dr McCarus: I think we tend to teach our unique tissue effects and absence of vi- students the instrument with which we sual effects, requires surgeons to think are most comfortable. After my initial in- differently. Is it helpful first to work on troduction of the array of devices, I don’t

S November 2009 / Supplement to OBG Management pull out different ones on every case. It’s effective in securing pedicles for vaginal not cost-effective. hysterectomy. And most recently, the ENSEAL® device provides temperature Issues of device choice control with a unique electrode con- Dr Brill: Which instruments do you prefer figuration and composition that heats for different surgical procedures? tissue at a low temperature while un- Dr McCarus: I choose Harmonic®, pri- der extremely high compressive force to marily for its ability to simultaneously produce a durable vascular seal. It is for cut, coagulate, and dissect tissue. I sel- these reasons that ENSEAL® is my tech- dom use bipolar devices, but when I do, nology of choice for vessel sealing. For I use ENSEAL®, particularly when tran- jobs that require fine dissection, I too rely secting larger vessels. on Harmonic® technology. Dr Bertrand: I’ve become interested in the ENSEAL® technology because it Best practices: Safe and effective produces only ~1 mm of spread. By off- use of technology setting the positive and negative elec- Dr Brill: Given the technical advances trodes, the flow of current is limited to provided by ENSEAL®, how do you ac- within the jaws. It allows me to get close tualize the promise of this technology? Compression to surrounding structures without fear of Dr McCarus: I first apply light tissue com- is key to excessive thermal spread. pression and visualize the I-Blade. I then maximizing Dr Brill: Dr Bertrand, you mentioned the bring the I-Blade to the tissue, activate seal strength. characteristics of ENSEAL® that attract the energy, and slowly advance it under you most: local regulation of current direct visualization to ensure control of and temperature. Additionally, you also the instrument. When using low voltage, noted that the minimal thermal spread compression is key to creating durable is a consequence of low temperature vessel seals. and that the current is uniquely chan- Dr Bertrand: I place the jaws on the pedi- neled between the jaws, which prevents cle and squeeze it, much as I would apply stray energy. Can you tell the differ- a Haney clamp. I then rotate the jaws so ence between a seal-and-cut done with I have a clear vision of the I-Blade and ENSEAL® versus the other devices? can bring it down onto the compressed Dr Bertrand: Yes, I can. Its small thermal tissue. As the tissue becomes denatured, margins are noticeable. The results are the I-Blade slides more easily. There are very similar to those obtained with the actually 2 ways to deliver energy, Single Harmonic® device. Tap and Double Tap. Single Tap is a 15- Dr Brill: My use of equipment has evolved second cycle which will tell me when the with the technologic development of de- tissue has reached 450 ohms or complete vices. First, the Gyrus PK platform, with coagulation has been reached. Double its pulsed, low-voltage energy, provides Tap is a 2-minute cycle, which does not continuous tissue impedance feedback.8 confirm this tissue impedance. I have Second, LigaSure™ allows the surgeon to transitioned to the Double Tap mode, close the automated device on a vascular primarily based on my comfort with the pedicle; the appropriate amount of ener- visual and tactile cues that the technol- gy required to seal tissue is applied, with ogy provides. effects regulated by impedance feedback, Dr Brill: You both emphasize the impor- leading to reliable hemostasis.7 Both tance of visualizing tissue effects as you Ligasure™ and Gyrus provide Haney advance the I-Blade. To reiterate, what Clamp–like instrumentation, which is separates this device from others is not www.obgmanagement.com Supplement to OBG Management / November 2009 S Advanced Energy systems for laparoscopic gynecology procedures

Understanding the energy principles behind laparoscopic gynecology surgery

Bipolar electrosurgery Derivatively, current is directly proportional A high-frequency alternating current applied to voltage and inversely proportional to to living tissue by an active electrode flows resistance (R). To complete a circuit, force through the tissue by pathways offering the or voltage must increase as resistance least resistance and return to an opposing increases. electrode. The flow of electrons or electrical Power is keyed into an electrosurgical current (I) is set in motion and sustained generator as watts (W), corresponding by electromotive force termed voltage to the rate of work being performed. The (V) to complete the circuit across the relationship between voltage and resistance difference in electrical potential between is restated by the derivation of power, W=I the 2 electrodes. Greater voltage produces x V, and by using Ohm’s law, W=I2 x R and greater thermal necrosis. W=V2/R; at any particular power setting Thermal injury correlates to the (W) using a conventional electrosurgery maximum tissue temperature, total volume generator, higher R as with desiccation, of heated tissue, rate of temperature rise, fat, or char will drive higher output V to and duration of temperature elevation. If maintain the desired tissue end point. living tissue is heated to above 50ºC for When you a sufficient duration of time, irreversible Ultrasonic surgery “follow the damage occurs; cellular water evaporates This type of surgery owes its efficacy bubbles,” tissue at 90ºC (desiccation); cell walls rupture at to the fact that ultrasound travels easily 100ºC (vaporization); and tissue begins to through water, which makes up roughly becomes easier carbonize and char at 250ºC. The temporal 80% of all soft tissue. High-intensity to cut. relationship between tissue temperature focused ultrasound transfers a significant and thermal injury is nonlinear owing to amount of energy to targeted tissue, the complex effects of conduction and causing a rise in temperature. convection on the entire process. Coagulation with ultrasound requires Practically speaking, thermal effects coaptation of blood vessels; H+ bonds can be moderated by altering the power are broken; and protein in the cells is setting, the type of output current (cut denatured. Denatured protein forms a vs blend vs coag), the electrode dwell sticky coagulum. Internal tissue heat time, the proximity of the tissue to generated from friction then seals or the active electrode, and the current welds vessel walls. Simultaneous cutting density (ie, electrode surface area). The and coagulation takes place at a lower behavior of electricity in living tissue is temperature than in electrosurgery with generally governed by Ohm’s law: V=I x R. minimal lateral thermal spread.

Brill AI. Energy systems for operative laparoscopy. Am J Assoc Gynecol Laparosc. 1998;5:333-349. Brill AI. Bipolar electrosurgery: convention and innovation. Clin Obstet Gynecol. 2008;51:153-158.

just the tremendous pressure that occurs point, I advance the I-Blade, typically at with advancing the I-Blade, but also the a rate of 1 mm per second, to follow the fact that so little water remains in the wave of bubbles. Using this method with pedicle when the cut is completed. I’ve the ENSEAL® device, I have never had a developed a visual pathway for using the problem with hemostasis for ligating and ENSEAL® device. I grasp a typical tissue cutting vascular pedicles. pedicle. I then activate the energy and ad- Dr McCarus: Have you noticed that when vance the I-Blade about halfway, which you “follow the bubbles,” tissue becomes begins to compress the tissue. I always somewhat easier to cut? stop at that point and, while applying Dr Brill: Absolutely. Normal collagen is energy, wait for the visual clue of bubbles very dense and relatively difficult to ma- that appear once the tissue has been de- nipulate. Denatured collagen becomes natured and the seal is complete. At that soft like butter. With the ENSEAL®

S November 2009 / Supplement to OBG Management device, you get feedback about resistance, than that associated with the ENSEAL® further letting you know that the pedicle device. However, when mastered, Har- is ready to be cut. monic® performs like no other. I appreci- The ENSEAL® device comes either ate the fact that ENSEAL® can achieve as a round-tipped 5-mm device or as a coagulation at lower temperatures than curved 3-mm device that looks like a other bipolar instruments. It likens itself curved surgical clamp. Do you prefer to Harmonic® as far as tissue effects. At one over the other? Do you use them the end of the day, it truly depends on differently? what the student values in terms of de- Dr McCarus: I use the ENSEAL® Trio vice qualities. exclusively. It is very comfortable to use Dr Brill: Dr Bertrand, do you use the Har- and is effective on large vascular bundles, monic ACE® as well? and for separating the leaves of the broad Dr Bertrand: I do. Dr McCarus trained ligament or opening the bladder flap. Its me to be a Harmonic® user with first- curved shape is similar to the Harmonic generation Harmonic® shears. With the ACE®. advent of the Harmonic ACE®, this tech- Dr Bertrand I have used both. I usually nology has become easier to use: You clamp use the larger device for the adnexa. it, click it, and it does the work for you. Variables When I want a curved tool for advanced I use the ENSEAL® on the adnexa. such as the dissection, I use Harmonic ACE®. When I perform the peritoneal separa- power setting, Dr Brill: I use both devices, but I prefer tion and open the right round ligament, blade edge, and the smaller curved device. As noted, it is I use the Harmonic ACE®. Its cavita- tissue tension more ergonomic and feels similar to nor- tional effect with the active blade on and density mal surgical instrumentation, and it pro- high power precisely dissects the bladder must be vides good mobilization of tissue planes. peritoneum. It causes very little, if any, evaluated. But again it begs the question, would you lateral tissue effect. I also like to use it have a first-time user begin with a 5- or to amputate the cervix, using a drilling 3-mm device using this technology? technique. Dr Bertrand: Wanting to minimize blood Dr McCarus: It’s difficult for many loss, I would pick the larger device. people to understand that, with Har- Dr McCarus: I’m not sure there is a dif- monic® technology, achieving hemosta- ference as far as hemostasis. They both sis depends on tissue density and tissue seem very effective. Again, I would teach tension. You have to be involved with a first-time user the proper technique for the instrument for proper performance. what I’m most comfortable with, the On vascular bundles, the technique has Trio. always been to clamp and relax tension. Dr Brill: You’ve taught an entire genera- But that is not always intuitive in han- tion of surgeons about ultrasonic sur- dling tissue. Variables such as the power gery. How does the Harmonic ACE® fit setting, blade edge, and tissue tension into this picture? and density must be evaluated. When I’m Dr McCarus: The ENSEAL® is similar near vital structures—the ureter, bladder, to Harmonic ACE® as far as minimizing or bowel—or I have an endometriosis, lateral thermal spread and ensuring ad- adhesion, or distortion, I need to be in equate coagulation.9-11 The Harmonic control of the energy. Harmonic® and ACE® has built its reputation on its su- ENSEAL® provide this control. perior multifunctionality and precision. Dr Brill: Ultimately, we must make choices. It can be technique-sensitive, which We can have only so many tools in a box. makes the learning curve slightly longer Based on our experience, preferences, and www.obgmanagement.com Supplement to OBG Management / November 2009 S Advanced Energy systems for laparoscopic gynecology procedures

skill levels, we will gravitate toward one Harmonic® energy is still the most ver- modality or another for surgical dissec- satile hand instrument allowing predict- tion. I am very comfortable having both able tissue effects when coagulating and the ENSEAL® device and the Harmonic cutting across the IP and uterine ovarian ACE® in my operating room for my cases ligaments, acquiring colpotomies, exci- and for my teaching. sion of endometriosis, appendectomy, Whenever I need to dissect near vital and myomectomy. structures—for example, during laparo- Dr Bertrand: Most of the time I’m proc- scopic myomectomy or excision of endo- toring or preceptoring, I use the 2 in- metriosis—monitoring tissue color and struments interchangeably. I use the temperature are important, and I always ENSEAL® device as a bipolar cutter for use the Harmonic ACE®. On the other the adnexa, and I use the Harmonic ACE® hand, if I’m performing a hysterectomy for the bladder, colpotomy, or amputa- and I’m concerned about the tenacity and tion, depending on whether I’m doing a strength of the vascular pedicles, and am total or a supracervical hysterectomy. having to mobilize and manipulate the Dr McCarus: The goal is safe surgery, to uterus, I will take out my ENSEAL® de- think about what we are doing to tis- The days of vice, which provides excellent hemostasis sue and minimize adverse effects. Do we clamp-cut-tie and minimizes thermal effects. What do really need to desiccate where there are are gone. you use in your OR? vital structures? The days of clamp-cut- Dr McCarus: We are very fortunate to tie or desiccate-cut are gone. Gaining have these choices. We all remember control over the energy and moderating when our options were much more lim- tissue effects is key. ited. I try to use one energy source, Har- Dr Brill: Just as a shielded trocar does not monic®, for all my cases, but there are preclude proper technique for trocar in- times when it is limited—eg, large tor- sertion, low-energy devices do not pre- tuous vessels or anatomy that requires clude the need for fundamentally correct increased tissue tension and retraction. technique that respects anatomy. n

References 1. Soderstrom RM. Electrosurgical injuries during laparos- 7. Brill AI. Bipolar electrosurgery: convention and innova- copy: prevention and management. Curr Opin Obstet tion. Clin Obstet Gynecol. 2008;51:153-158. Gynecol. 1994;6:248-250. 8. Presthus JB, Brooks PG, Kirchlof N. Vessel sealing using 2. Tucker RD, Voyles CR. Laparoscopic electrosurgical a pulsed bipolar system and open forceps. J Am Assoc complications and their prevention. AORN J. 1995;62: Gynecol Laparosc. 2003;10:528-533. 51-59. 9. Amaral JF, Chrostek C. Depth of thermal injury: ultra- 3. Luciano A, Soderstrom R, Martin D. Essential principles sonically activated scalpel vs. electrosurgery. Surg En- of electrosurgery in operative laparoscopy. J Am Assoc dosc. 1995;9:226. Gynecol Laparosc. 1994;1:189-195. 10. Bandman J, Kerbl K, Rehman J, et al. Evaluation of a 4. Brill AI. Energy systems for operative laparoscopy. Am J vessel sealing system, bipolar electrosurgery, harmonic Assoc Gynecol Laparosc. 1998;5:333-349. scalpel, titanium clips, endoscopic gastrointestinal anas- 5. Vaincaillie TG. Electrosurgery at laparoscopy: guide- tomosis vascular staples and sutures for arterial and lines to avoid complication. Gynaecol Endosc. 1994;3: venous ligation in a porcine model. J Urol. 2003;169: 143-150. 667-700. 6. Ryder RM, Hulka JF. Bladder and bowel injury after 11. McCarus SD. Physiologic mechanism of the ultrasonical- electrodesiccation with Kleppinger bipolar forceps: a ly activated scalpel. J Am Assoc Gynecol Laparosc. 1996; clinicopathologic study. J Reprod Med. 1999;3:595-598. 3:601-608.

S November 2009 / Supplement to OBG Management