Use of the LigaSure™ Vessel Sealing System in Urologic Cancer Surgery

E. David Crawford, MD; Jenifer S. Kennedy, PhD; Vonne Sieve

The LigaSure™ Vessel Sealing System effectively seals vessels 1 mm to 7 mm in diameter with minimal sticking, charring or thermal spread.

•     Prostatectomy, cystectomy and nephrectomy have been completed using the LigaSure Vessel Sealing System.

•     Use of the LigaSure Vessel Sealing System for urologic surgery has shown a significant reduction in blood loss.

•     The LigaSure system is cost-effective and can minimize time in surgery.

•     In recent trials, seals made with the LigaSure system healed normally, with no postoperative bleeding or complications.

Introduction
Hemostasis is fundamental in urologic cancer surgery.  There are several methods of achieving hemostasis, including clips, sutures and ultrasonic coagulation, as well as both monopolar and bipolar coagulation.  Each method offers benefits and also has limitations.  Clips are easily placed, but can be expensive and can become dislodged.  Sutures can be a tedious option.  Standard bipolar and ultrasonic coagulation can be used to coagulate small blood vessels in the 1-mm to 3-mm range, but can be slow and result in undesirable lateral thermal injury. Ultrasonic coagulation can also be expensive.  Despite all of these options, blood loss can often be significant in complex cancer surgery procedures due to difficult dissection through solid tissues.

A new method of achieving hemostasis has been developed for use in place of clips, sutures and other energy-based ligation methods.  Developed by Valleylab, the LigaSure Vessel Sealing System effectively seals vessels 1 mm to 7 mm in diameter with minimal sticking, charring or thermal spread.  Tissues can be sealed without dissection or vessel isolation, which can cause unnecessary bleeding.   Use of the LigaSure Vessel Sealing System for urologic surgery has shown a significant reduction in blood loss, which may decrease the need for blood transfusions and the associated patient risks.

This paper presents the use of the LigaSure Vessel Sealing System in urologic cancer surgery. Prostatectomy, cystectomy and nephrectomy have been completed relying on LigaSure Vessel Sealing Technology™ as the primary means of achieving hemostasis.  The surgical technique is described and the potential benefits of using this vessel sealing technology are discussed.

Materials and Methods
LigaSure with Vessel Sealing Technology works by applying a precise amount of bipolar energy and pressure to change the nature of the vessel walls.  The collagen and elastin within the vessel walls fuse and reform into a single structure, obliterating the lumen, and creating a permanent seal.

The system consists of a bipolar radio frequency (RF) generator and forceps (Figure 1).  The instruments are designed to mimic standard surgical clamps.  They are available in a 7-inch Pean-style clamp (LigaSure Standard), a 9-inch Heaney-style clamp (LigaSure Max) and a 5-mm laparoscopic Maryland-style grasper/dissector (LigaSure Lap). The vessel to be sealed is grasped in the jaws of the instrument and a calibrated force is applied to the tissue.

Figure 1.

A recent study compared the LigaSure Vessel Sealing System with ultrasonic coagulation, bipolar coagulation, surgical clips and sutures.1  In this study, 210 freshly excised porcine renal arteries ranging from 3 mm to 7 mm in diameter were occluded using the LigaSure System, ultrasonic coagulator, bipolar forceps, mechanical clips or standard silk ties.  The vessels were then cannulated and pressurized with saline using a syringe pump until the occlusion burst.  Pressure was recorded when the occluded or normal vessel wall burst, or when the measurement system reached its maximum pressure of 900 mmHg.  The study results demonstrated that the LigaSure System creates seals that are stronger than other energy-based ligation methods (ultrasonic coagulation and standard bipolar coagulation), and comparable in strength to mechanical ligation techniques such as clips and sutures.2   Seals created by the LigaSure System were shown to withstand a minimum of three times normal systolic pressure.3

Two preclinical chronic animal trials were completed to verify adequate healing when using this vessel sealing system.  Seals were harvested at 2, 5, 7, 10 and 20 days postoperatively for histologic evaluation.  The seals progressed through a normal healing process and did not slough off.  Seal durability and vessel wall fusion were obvious on visual and histologic inspection.  There were no postoperative complications or bleeding in either trial.4  Results from these trials indicate that the LigaSure Vessel Sealing System is a viable alternative to clips, staples and sutures for ligating vessels and vascular bundles reliably during surgery.

The LigaSure Vessel Sealing System can be a cost-effective alternative for achieving hemostasis, depending on current surgical technique.  Typically, during a radical prostatectomy, two each of three different sizes of clip cartridges may be used with reusable clip appliers.  The cost is approximately $210.  If disposable clip appliers are used, this cost could double.  In addition, one can assume a nominal $50 for suture.  If an ultrasonic coagulator is used for $325, the cost for hemostasis in a prostatectomy procedure would be approximately $585.  The cost per procedure for the LigaSure open instruments (Standard and Max handsets) is $150, and the cost for the laparoscopic instrument is $225.  If two LigaSure instruments are used in order to optimize device configuration for anatomical variations within the procedure, the cost would be $375.  This analysis does not consider the significant savings that may occur with lower transfusion rates if total blood loss is reduced.

Specific Uses
Use of the LigaSure Vessel Sealing System was recently evaluated during the performance of a number of urological cancer procedures including radical prostatectomy, radical cystectomy, radical inguinal orchiectomy and radical nephrectomy at the University of Colorado Health Sciences Center (UCHSC).  In each procedure, vessels were sealed using the LigaSure Vessel Sealing System whenever possible.  The LigaSure Standard, Max and Lap handsets were alternated as necessary to optimize anatomical access.  Instrument prototypes specifically designed for urology are currently being evaluated.

Radical Retropubic Prostatectomy
With the use of the LigaSure Vessel Sealing System, radical retropubic prostatectomy can be completed without relying on clips or suture for hemostasis (suture is, of course, required for anastamosis).  The current instrument configurations provided effective hemostasis throughout the procedure.

This procedure begins in the standard manner with a mid-line incision from synthesis pubis to the lateral side of the umbilicus.  Dissection is continued inferiorly and laterally until the external iliac vessels are seen.  At this point, it is important to maintain depth or the epigastric vessels may be injured, which would complicate the approach to the prostate and pelvic vasculature.  If aggressive disease (>2% chance of pelvic lymph node disease) is suggested on the preoperative evaluation, a bilateral lymphadenectomy is recommended.

The LigaSure Lap instrument, a 5-mm Maryland style grasper/dissector, may be used for this portion of the procedure.  Though designed for laparoscopic procedures, the added length facilitates access to target structures.  We have found this device to provide excellent sealing of lymphatic tissues.

Upon completion of the pelvic lymph node dissection, preparation is made for the radical prostatectomy.  With traction on the Foley catheter, the catheter can be felt.  Place the Babcock clamp on this tube at the bladder neck.  The LigaSure device is used to divide lateral tissue and isolate the bladder neck as it funnels into the prostate.  The right angle clamp is placed posteriorly, separating the posterior portion of the prostate and bladder neck.  Place the vessel loop around this and continue inferiorly into the prostatic urethra.  Then, divide the bladder neck (Figure 2).  Dissection is continued posteriorly until the vasa and seminal vesicles are identified.  This is accomplished by using the electrosurgical pencil to make an incision between the bladder neck posteriorly and the prostate, not too far proximal into the bladder neck or too distal into the prostate.

Figure 2.

Dissection of the Bladder Neck

      At this point, the vasa is visualized. Proceed with lateral dissection to further expose the vasa and seminal vesicle.  Use the LigaSure Lap device on each side to control bleeding from the seminal vesicle pedicle (Figures 3 and 4).  Place a right angle clamp posterior to the vasa; divide the vasa using the LigaSure Max.

Figure 3.

Application of the Vessel Sealing Device to the Vasa

Figure 4.

Seal Resulting From Application of the Vessel Sealing Device (Vas)

Place a Babcock clamp on the proximal end of the vasa to assist in removal of the seminal vesicle; small bleeders are common.  These are handled using an electrosurgical pencil.  Seal and ligate the artery that enters the seminal vesicle.  Now proceed to the other side until dissection of the seminal vesicle is complete.

Dissect the prostate base from the anterior rectal wall.  An incision in the posterior leaf of the anterior layer of Denovillers’ fascia allows entry into the plane between the prostate and rectum.  Place your finger into the incision.  With a lateral sweeping motion, free the rectum from the prostate.  Move your finger towards the apex of the prostate to remove the rectum from the prostate.  Once the apex is identified, spare the neurovascular structures by insinuating a finger on each side of the urethra. Dissect the neurovascular structures laterally to the base of the prostate.

Using a finger, sweep away from the rectum to thin down the lateral pedicle.  Place a pedicle clamp from the apex to the base.  Attach a 1/4” Penrose drain and elevate it to identify the pedicle.  If nerve sparing has been performed, care should be taken not to injure the nerves.  Suture ligatures are difficult to place around this pedicle.  The LigaSure Max handset was used to divide the lateral pedicle from the base to the apex of the prostate (thickest tissue is at the base) (Figures 5 and 6).  Now, the lateral aspect of the prostate is free. Perform the same maneuver on the other side.

Figure 5.

Figure 6.

At this point, the puboprostatic ligaments, urethra and dorsal vein complex are the only attachments to the prostate.  The ligaments are sharply divided on each side.  The dorsal vein complex is visualized in the center of the operative area.  The LigaSure Max was used to divide the dorsal vein complex (Figures 7 and 8).  Cut down to the urethra to minimize bleeding, which can be controlled with the LigaSure Lap handset.  The urethra is now the only attachment to the prostate.

Figure 7.

Figure 8.

Radical Cystectomy
There are many opportunities to use the LigaSure devices in the performance of a radical cystectomy and urinary diversion.  As described above, the LigaSure laparoscopic and standard handsets can be used for the lymphadenectomy, thus eliminating the use of clips.  When performing a radical cystectomy, I develop a lateral and posterior pedicle.  The LigaSure Max device is ideal for ligating both pedicles (Figure 9).

Figure 9.

Index Finger Inserted Behind the Hypogastric Artery. 

The LigaSure device also saves time when dividing the mesentery for the small or large bowel to be used for the anastamosis.  The device can be used in any step of the procedure where coagulation, tying or clipping of vessels (from 1 mm to 7 mm in diameter) is necessary.  This device is easy to use and can quickly become a routine tool in surgery.

Radical Nephrectomy
The LigaSure system offers similar benefits to those previously described when used in a radical nephrectomy procedure.  When completing this procedure, over 100 seals were made in place of suture and clips.  Use of the LigaSure vessel sealing device decreased procedure time and minimized foreign material left in the patient.

The vessel sealing handset was used to divide the ureter, lateral and posterior attachments of the kidney and its fascia; the vessels along the aorta and vena cava; and the adrenal vessels.  The LigaSure Standard instrument was predominantly used to perform these procedures; however, the LigaSure Max and the LigaSure Lap were used when extra length was required to access the deep structures in the abdomen.  The procedure is detailed below and use of LigaSure instruments are specified where applicable.

Once the self-retaining retractor is applied between the ribs in the posterior aspect of the wound, the descending colon is held up and the peritoneum of the lateral paracolic gutter is incised. Superiorly, this incision is carried through the anterior lamella of the splenocolic ligament for left-sided cancers, allowing mobilization of the splenic flexure.  At this point, care must be taken not to injure the inferior pole of the spleen.

The splenic flexure and the descending colon are bluntly mobilized from the underlying Gerota’s fascia and retroperitoneum.  With the hand inside the abdomen, lift the colon.  At this point, the anteromedial aspect of the vena cava is visible medially; superiorly, the superior mesenteric artery is visible.  Anterosuperiorly, the posterior surface of the pancreas and the splenic vessels can also be seen.  The adrenal vein is divided using the LigaSure device.  Retract the renal vein downward to allow palpation and dissection of the renal artery.  The renal artery is ligated in continuity, but not divided yet.  The accessory renal arteries are similarly ligated if detected.  Ligate and divide the renal vein where it terminates at the inferior vena cava.  Double application of the device in a side-by-side manner may be prudent.  When ligating the renal vessels, keep in mind that the LigaSure instruments should not be used on vessels >7 mm in diameter.  Check for any lumbar vein entering the renal vein from behind the vessel.  The lumbar vein can be divided using the LigaSure vessel sealing device.  Since the renal artery is already ligated, continue to dissect further up to its origin where it is ligated and divided.

Beginning below the renal vessels that have already been divided, push the Gerota’s fascia laterally away from the psoas major.  In the UCHSC trials, the LigaSure device was used to ligate a few of the large collateral vessels on the kidney and to release the Gerota’s fascia covering the kidney (Figures 10, 11a, 11b, 11c).  Continuing the dissection superiorly, release the thin layer of Gerota’s fascia from the adrenal gland and on the inferior surface of the diaphragm.  The small adrenal branches off the aorta and phrenic arteries can also be ligated using this device.  When these vessels bleed, they can be difficult to access with other hemostasis methods such as clips or sutures.  Use of the LigaSure vessel sealing device is ideal in this circumstance (Figure 12).  Once the vessels attaching the kidney and adrenal gland are ligated, both the kidney and adrenal gland can be removed.  Continue the procedure in the standard manner (Figure 13).

Figure 10.

Figure 11a.

Application of the Vessel Sealing Device to Supporting Tissue

Figure 11b.

Figure 11c.

The Seal is Cut.  No Bleeding Demonstrates Complete Hemostasis.

Figure 12.

Sealing of a Vessel Around the Kidney

Figure 13.

Ligation of the Ureter Using the Vessel Sealing Device

Unilateral Inguinal Orchiectomy
The LigaSure device was used on the spermatic cord structures and vas while performing this procedure.  Once the spermatic cord was identified and dissected free from the vas, it was divided.  The spermatic cord and the vas were successfully ligated using the LigaSure Max handset (Figures 14 and 15).

Figure 14.

Figure 15.

The Sealed Vessel

Conclusions
LigaSure with Vessel Sealing Technology has many uses for both urologic cancer procedures and general urologic surgery.  It has been used in prostatectomy, cystectomy and nephrectomy procedures, and has proven to seal vessels reliably with minimal thermal spread.  It is a cost-effective tool that can reduce blood loss and save time in surgery.  The healing process was examined in two chronic animal studies, which both demonstrated that the seals progressed through a normal healing process and did not slough off.  There were no postoperative complications or bleeding in either trial.

The development of an electrosurgical generator with multiple output receptacles and new instruments specific to urologic surgery will further enhance the benefits that the LigaSure System has to offer.

References

1.   Kennedy JS, Stranahan PL, Taylor KD, Chandler JG. High-burst strength, feedback-controlled bipolar vessel sealing. Surgical Endoscopy Ultrasound and Interventional Techniques.  1998;12:867-878.

2.   Kennedy J, Taylor K, Chandler J. High burst strength, servoregulated, bipolar vessel sealing. Paper presented at: 5th Annual Congress of  The European Association for Endoscopic Surgery; Instanbul, Turkey; Joint Euro-Asian Congress of Endoscopic Surgery; June 1997; Bologna, Italy.

3.   Kennedy JS, Buysse SP, Lawes KR, Ryan TP. Recent innovations in bipolar electrosurgery. Minimally Invasive Therapy and Allied Technologies.  1999;8(2):95-99.

4.   Kennedy JS, Stranahan PL, Buysse SP, Ryan TP, Pearce JA, Thomsen S. Large vessel ligation using bipolar energy: a chronic animal study and histologic evaluation. Paper presented at: 7th International Meeting of the Society for Minimally Invasive Therapy; 1995.