based on grade of tumor and patient age, which adopts a more patient-centered approach, rather than a disease-focused approach of mostconventional risk stratification schema. It is interesting to note that high rates of curative therapy, mainly radiation therapy, were observedin patients with low-risk disease. Although radical prostatectomy was age sensitive, radiation therapy use did not change with age, evenbeyond 75 years when treatment value is very questionable. This result may be fostered by an impression that these men better toleratedradiation therapy. However, that still does not justify overtreatment. Most interestingly, the rate of expectant management/androgendeprivation therapy for men with poorly differentiated cancer was higher than that for moderately differentiated tumors. This relativeunderutilization of curative treatment is hard to explain. It is possible that this may be a gross overestimation, given that many men mayhave received neoadjuvant hormonal therapy, followed by radiation, which is not captured in the Surveillance, Epidemiology, and EndResults database. Although it is to be acknowledged that single modality curative therapy is not uniformly effective in men with highGleason tumors, the efficacy is not so low as to justify switching to expectant treatment or primary androgen deprivation therapy.

doi:10.1016/j.urolonc.2006.11.005Badrinath Konety, M.D., M.B.A.

LABORATORY RESEARCH

Comparison of holding strength of suture anchors for hepatic and renal parenchyma. Ames CD, Perrone JM, Frisella AJ, MorrisseyK, Landman J, Division of Urology, Washington University School of Medicine, St. Louis, MO.

J Endourol 2005;19:1221–5

Background and Purpose: Various laparoscopic devices have been described for suture anchoring during solid organ parenchymalclosure. Application of these devices expedites the closure of parenchymal defects and minimizes ischemia time. We compared differenttechnologies as suture anchors for parenchymal closure.

Materials and Methods: A tensometer was used to determine the amount of tension necessary to dislodge each of five different clipsfrom Vicryl suture alone or against two different substrates (fresh pig kidney and liver) with and without an intervening pledget. The clipsinvestigated were the Lapra-Ty (Ethicon), Endoclip II (US Surgical), small Horizon Ligating Clips (Weck), Hem-o-lok Medium PolymerClips (Weck), and a novel Suture-clip (Applied Medical). ANOVA and two-sided Fisher’s exact test provided statistical analysis.

Results: The force required to dislodge the Lapra-Ty clip from bare suture for both 0 and 1 Vicryl (7.0 N) was approximately fourfoldthe force required to dislodge the Endoclips or the 5-mm or 10-mm Hem-o-lok clips (p�0.01). When clips were applied to suture runningthrough renal or liver parenchyma, the novel Suture-clip required the greatest tension to dislodge (P�0.01), followed by the Horizon andLapra-Ty clips. There were no statistically significant differences in the tension required to dislodge a given clip from the two parenchymalsubstrates or in the presence or absence of a pledget.

Conclusions: In our experimental model, the Suture-clip, Lapra-Ty, and Horizon clips required significantly greater tension to dislodgethan the Hem-o-lok and Endoclip clips. The addition of a pledget did not improve tension resistance.

Commentary

Although laparoscopic knot tying is a skill that can be learned through repetition in a dry lab, the use of this technique for laparoscopicpartial nephrectomy can make for a challenging and often rather frustrating time in the operating room. Laparoscopic approximation of renaltissue through tensioning of sutures over bolsters is difficult enough but then to tie a knot while maintaining adequate tension may requirean assistant to “hold” the knot while the second throw is prepared. To overcome this problem, a number of suture anchoring devices havebeen developed to obviate the need for knot tying.

In this article, Ames et al. evaluated suture anchoring devices and found that of the commercially available anchors, both the HorizonLigating Clips and the Lapra-Ty held suture well enough to resist suture tensioning forces great enough to cause renal parenchymal tearing.Although these anchors were not compared against a traditional surgical knot, any anchor that can hold a suture against tension sufficientto tear through the renal parenchyma is likely adequate for use during laparoscopic partial nephrectomy. Interestingly, there was an equalfrequency of parenchymal tearing whether or not a Surgicel pledget was inserted between the anchor and the parenchyma.

Although the use of these devices has been previously reported in small clinical series, this report should help alleviate any doubt aboutthe effectiveness of these devices for use during partial nephrectomy. Despite the proliferation of hemostatic agents and energy basedcoagulation devices (ultrasonic shears, radiofrequency based coagulation, etc.), there are currently no well-proven alternatives to suturedrepairs (generally with bolsters) following large and deep partial nephrectomy resections. The Horizon Ligating Clip or Lapra-Ty makerepair after this type of laparoscopic partial nephrectomy significantly more rapid than can be achieved with knot tying.

doi:10.1016/j.urolonc.2006.08.023Kyle Anderson, M.D.

Acute integrity of closure for partial nephrectomy: Comparison of 7 agents in a hypertensive porcine model. Johnston WK III, KelelKM, Hollenbeck BK, Daignault S, Wolf JS Jr, Department of Urology, University of Michigan and Veterans Administration Medical Center,Ann Arbor, MI.

J Urol 2006;175:2307-11

Purpose: We assessed the acute effectiveness of closure after partial nephrectomy of 7 techniques in a large hypertensive porcine model usingshallow and deep resections to approximate clinical situations.

93K. Anderson / Urologic Oncology: Seminars and Original Investigations 25 (2007) 87–95

Materials and Methods: Open surgical partial nephrectomy with hilar clamping was performed in pigs weighing 150 to 200 lbs, includingsmall-a quarter length and a quarter width of kidney, medium-a third length and a third width of kidney, and into the renal sinus and up to thecollecting system, and large-lower pole heminephrectomy at the renal sinus. Seven agents were compared after a single application, namelythrombin/collagen granules, polyethylene glycol hydrogel, fibrin glue, thrombin/gelatin granules, cyanoacrylate glue, fibrin glue/gelatin sponge andsutured bolster. Failure and success were determined by the presence or absence of bleeding, respectively, after unclamping and by an increasein SBP to 100 and then to 200 mm Hg with dopamine infusion.

Results: Of 70 partial nephrectomies the success rates were 33% and 14% for thrombin/collagen granules, and 67% and 0% for polyethyleneglycol hydrogel in small and medium resections; 100%, 71% and 0% for fibrin glue, and 100%, 86% and 0% for thrombin/gelatin granules in small,medium and large resections; and 67% and 80% for cyanoacrylate glue, 100% and 20% for fibrin glue/gelatin sponge, and 100% for sutured bolsterin medium and large resections, respectively. Of the kidneys that did not bleed at an SBP of 100 mm Hg 31% bled at 200 mm Hg.

Conclusions: There is considerable variability among agents. Most were effective for small resections and some worked for medium resectionsbut for large resections only sutured bolster was consistently effective. SBP also appears to be an important factor. These results bear on theselection of techniques during laparoscopic partial nephrectomy.

Commentary

Multiple different hemostatic agents have been used to control bleeding after laparoscopic partial nephrectomy, but it has been difficult toidentify a clearly superior agent because few comparative trials have been performed. To address this shortcoming, the authors used dopamine tocreate a hypertensive (systolic blood pressure of 200 mm Hg) porcine kidney model and then tested multiple hemostatic agents using 3 differentstandardized sizes of renal resection: small, a quarter length and a quarter width of kidney; medium, a third length and a third width of kidney;and large, lower pole heminephrectomy. Unfortunately, the number of treatment groups precluded statistical analysis, but the results were sufficientto draw general conclusions. After large resections, cyanoacrylate glue was somewhat effective, stopping bleeding in 80% of cases. Still, nohemostatic agent approached the 100% effectiveness of sutured bolsters. Thrombin/gelatin granules, fibrin glue, and fibrin glue plus gelatin spongeworked well for medium resections, but no surgeon would be happy with the hemostatic success rate of 0% to 20% these agents achieved afterlarge resection. The remaining agents (polyethylene glycol hydrogel and thrombin/collagen granules) had limited effectiveness, even for smallresections.

It takes little experience with partial nephrectomy to realize that the difficulty controlling bleeding increases greatly with proximity to largecentral vessels. The results of this study confirm this point well. There were multiple agents that were effective for small resections in this porcinemodel, but for large resections, sutured bolsters were required. Translating these data to human beings is somewhat difficult because it is not clearwhat exact size of resection in a human being correlates to the medium and large resections in this hypertensive pig model. However, clinicalreports on laparoscopic partial nephrectomy suggest that after smaller resections, a hemostatic agent alone can be successful, while sutured bolstersimprove outcomes after larger and deeper resections [1,2]. This being said, the remaining question for these hemostatic agents may be which oneis most effective when used in conjunction with sutured bolsters after large resections.

doi:10.1016/j.urolonc.2006.08.024Kyle Anderson, M.D.

References

[1] Finley DS, Lee DI, Eichel L, et al. Fibrin glue-oxidized cellulose sandwich for laparoscopic wedge resection of small renal lesions. J Urol2005;173:1477–81.

[2] Johnston WK III, Montgomery JS, Seifman BD, et al. Fibrin glue v sutured bolster: Lessons learned during 100 laparoscopic partial nephrectomies. J Urol2005;174:47–52.

Bloodless partial nephrectomy with a new high-intensity collimated ultrasonic coagulating applicator in the porcine model. MuratFJ, Lafon C, Cathignol D, Theillere Y, Gelet A, Chapelon JY, Martin X, Department of Urology, Edouard Herriot Hospital, Lyon, France.

Urology 2006;68:226–30

Objectives: To evaluate the long-term hemostatic efficacy of a new high-intensity collimated ultrasonic (HICU) applicator for opensubhilar partial nephrectomy (PN) in the porcine model.

Methods: An applicator was designed with a planar 3.78-MHz HICU transducer and a reflector to optimize the delivery of acousticenergy to coagulate renal tissue. Six female pigs underwent right PN, followed at day 7 by left PN. The 6 pigs were killed on day 14. Thetreatment consisted of delivering HICU to a lower pole subhilar location, under a vascular clamp, then releasing the clamp, and cutting thekidney lower pole. The immediate and delayed hemostatic efficacy, treatment parameters, blood loss, complications, and renal function wereevaluated at each surgical event and at necropsy.

Results: Perfect hemostasis was achieved with all 12 kidneys, with a mean treatment time of 7.2 minutes (range 5 to 9.2). The meanproportion of resected parenchyma was 21% (range 14% to 32%). No renal function impairment and no major complications were recorded.At necropsy, no secondary hematoma was observed, and three urinomas (25%) were found.

Conclusions: Our HICU applicator has shown promising results during PN in the pig model with no other method of hemostasis. Morestudies are needed to refine our probe for laparoscopic surgery, improve its ergonomics, and extend our experiments to human laparoscopicnephron-sparing surgery.

94 K. Anderson / Urologic Oncology: Seminars and Original Investigations 25 (2007) 87–95