- Email: [email protected]
A Novel Resectoscope for Transurethral Resection of Bladder Tumors and the Prostate
A Novel Resectoscope for Transurethral Resection of Bladder Tumors and the Prostate Allan J. Pantuck,* Jack Baniel, Ziya Kirkali, Tobias Klatte, Nazy Zomorodian, Ofer Yossepowitch† and Arie S. Belldegrun From the David Geffen School of Medicine at University of California-Los Angeles (AJP, TK, NZ, ASB), Los Angeles, California, Dokuz Eylul University School of Medicine (ZK), Izmir, Turkey, and Tel Aviv University (JB, OY), Tel Aviv, Israel
Purpose: Transurethral bladder tumor resection is associated with imperfect clinical staging and incomplete tumor removal. Transurethral prostate resection may be complicated by inadvertent damage to the urinary sphincter, bladder neck and trigone. We performed a multicenter pilot and feasibility study of a novel working element for resectoscopes designed to improve the efficacy and safety of transurethral endoscopic surgery. Materials and Methods: An innovative working element for resectoscopes was developed to convert the standard in/out linear/axial movement at the handgrip into a side-to-side, bidirectional, lateral rotating motion. The device is compatible with current optical technology and conventional electrocautery generators, and it has been granted marketing approval. It consists of variably sized cutting loops designed for transurethral resection of bladder tumors and the prostate. To date 80 patients with bladder cancer (38) or benign prostatic hyperplasia (42) have undergone surgery with this instrument at our 3 clinical sites. Results: No safety concerns were evident. When used during transurethral bladder tumor resection, lateral resection at the base of the tumor enabled accurate depth of penetration into the bladder wall, which may decrease the risk of bladder perforation and improve pathological assessment of tumor invasion. During transurethral prostate resection this novel tool facilitated dissection of adenoma adjacent to the verumontanum and prostatovesical junction, which may decrease the risk of sphincteric damage and bladder neck injury. Conclusions: A novel resectoscope is currently under prospective clinical investigation to establish its surgical and pathological efficacy, ease of use and side effect profile. Current data suggest that the learning curve is mild, its use is safe and it provides distinct advantages when used for transurethral resection of bladder tumors and the prostate. Key Words: prostate, transurethral resection of prostate, prostatic hyperplasia, bladder neoplasms, endoscopy
ransurethral resection is the cornerstone of surgical management for bladder cancer and BPH. In 2007 bladder cancer newly affected 67,000 Americans1 with most lesions diagnosed at a superficial, noninvasive stage. TUR is an integral part of the diagnostic evaluation of all bladder tumors and it represents the standard surgical therapy for noninvasive bladder cancer. However, this procedure is associated with imperfect clinical staging, incomplete tumor removal2 and perioperative complications such as bladder perforation and bleeding.3 The prevalence of BPH is about 20% in 40 to 70-yearold men.4 Despite the introduction of ablative and less invasive alternatives TURP remains the gold standard for surgical therapy for BPH and it is one of the most frequently performed operations in urology. Of participants
T
Submitted for publication April 24, 2007. Study received approval from local institutional review boards at each study center. * Correspondence and requests for reprints: Department of Urology, David Geffen School of Medicine at University of California-Los Angeles, 10833 Le Conte Ave., Room B7-298A CHS, Los Angeles, California 90025-1738 (telephone: 310-206-2436; FAX: 310-2064082; e-mail: [email protected]). † Financial interest and/or other relationship with Roei Medical Technologies Ltd.
0022-5347/07/1786-2331/0 THE JOURNAL OF UROLOGY® Copyright © 2007 by AMERICAN UROLOGICAL ASSOCIATION
in a population based study the percent of men undergoing TURP in the age groups 40 to 49, 50 to 59 and 60 to 70 was 0.8%, 4.5% and 8.5%, respectively.4 Like TURBT, TURP is associated with well-known morbidities at a rate of up to 30%, including TUR syndrome, bleeding, infection, urinary retention, incontinence, urethral stricture, bladder neck stenosis and retrograde ejaculation.5 Standard resectoscopes for transurethral resection comprise an optical lens, a sheath, an obturator, a working element and a disposable cutting loop. The most significant advance in resectoscope equipment was achieved more than 30 years ago with the introduction of the Iglesias working element into clinical practice.6 Recently a new working element for TUR was developed that converts the standard in/out linear/axial movement at the handgrip into a side-to-side, bidirectional, lateral rotating motion that allows a circular side-to-side cutting motion. Due to its unique design it may decrease some risks of TUR, such as bladder perforation, enable more adequate tissue assessment with regard to tumor invasion and facilitate dissection of BPH adjacent to the verumontanum and prostatovesical junction. We report what is to our knowledge the first clinical assessment of this novel resectoscope in a multicenter pilot and feasibility study performed to determine its clinical applicability.
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Vol. 178, 2331-2336, December 2007 Printed in U.S.A. DOI:10.1016/j.juro.2007.08.042
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MATERIALS AND METHODS Equipment and Technique A novel resectoscope for TURBT and TURP was developed. The resectoscope includes a telescope, a working element, a sheath, disposable cutting loops and high frequency cables. It is similar to other Food and Drug Administration and CE marking cleared resectoscopes. Specifically the resectoscope is designed to use the same electrocautery generators and it is similarly compatible with various resectoscope accessories. The cutting loops are fabricated from the same materials as Karl Storz™ and ACMI™ resectoscopes. The safety and feasibility of the novel resectoscope were previously tested in a porcine animal model.7 In these preclinical studies, which were performed before testing in humans and reported in 2004 at the annual meeting of the American Urological Association, no adverse events or device malfunction were observed. None of the test animals experienced electrical burns, no effects were noted on animal vital signs and an assessment of the resected bladders revealed clean resection craters without evidence of perforation. The principal technological differences between the current resectoscope and others are in the design of the working element and cutting loops that translate the axial maneuver at the handgrip into a lateral rotational movement of the cutting loop. The loop is oriented parallel to the resectoscope shaft and it lies entirely in the sheath at its resting position (fig. 1, A). The proximal handgrip of the resectoscope working element is designed to allow circular, side-to-side cutting motion of the cutting loop independent of the resectoscope sheath. In its passive version pressing the thumb grip against the index finger allows the loop to extend outside of the sheath (linear movement), followed by rotation in a plane perpendicular to the shaft (fig. 1). The loop can then be moved in a clockwise or counterclockwise course depending on whether the thumb is being pressed or released against the index finger. In contrast, other resectoscopes accomplish a cutting motion in tissue using electrode rotation to move the cutting tool, eg as in the Karl Storz resectoscope, or rotation of the entire working element and telescope independent of the resectoscope sheath, eg as in the ACMI resectoscope. The working element and loops of the novel resectoscope are compatible with a standard 24Fr resectoscope sheath, and conventional monopolar cutting and cautery electrical settings. Small, medium and large loops are available for TURBT and TURP, correspondingly (fig. 2). For TURBT the small loop would generally be used. The loop is pushed outside of the sheath and placed at level of healthy mucosa lateral to the tumor. Turning the loop in a circular axis while activating the cutting current allows the lesion to be scooped out with its underlying base as a complete, intact specimen (fig. 3). The depth of penetration beneath the tumor is preset by the cutting wire arch, ie the distance between its tip and the rod. This distance is set at 3.4 mm, thereby allowing resection into the muscle layer while avoiding bladder perforation. For larger tumors resection is done in several cuts. The theory of this design is to provide pathologists with a 3-dimensionally oriented specimen (tumor-submucosa-muscle) and potentially allow better clinical staging of the cancer. Finally, hemostasis is achieved by allowing the loop to retract back into the sheath, approx-
FIG. 1. Working element dual motion technique with passive design. A, at resting position cutting loop is fully retracted inside resectoscope sheath. B, forwarding working element thumb grip against index finger allows partial or full extension of cutting loop outside of sheath. Loop is oriented parallel to the resectoscope shaft. C, further pressing of thumb grip activates second mechanism enabling side-to-side rotation of cutting loop, which can be moved in clockwise or counterclockwise fashion.
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FIG. 2. Small, medium and large loops are available for TURBT and TURP, correspondingly. Dimensions are shown in mm. TURBT/P, TUR of bladder tumor or prostate.
imating the optic to the tissue and identifying and securing any bleeders by activating cautery. TURP is performed generally using a large loop, and standard cutting and cautery settings (fig. 4). Resection is started at the bladder neck, as with the standard Nesbit TURP technique. The circular axis of resection is particularly useful in patients with a large median lobe because the loop is not extended beyond the adenoma blindly into the bladder, potentially minimizing the risk of inadvertent damage to the orifices. Adenoma removal can then be safely continued in proximal-to-distal fashion. As long as the resectoscope shaft maintains its static position in the urethra to the level of the verumontanum, the circular cutting axis prevents inadvertent damage to the sphincter. Pilot Study Our pilot study (ClinicalTrials.gov Identifier: NCT00303654) was designed to investigate the safety, feasibility and efficacy of the resectoscope with regard to tissue quality, surgeon satisfaction and perioperative complications. The study accrued 80 patients who underwent TUR for bladder cancer (38) or BPH (42). TUR was performed by 4 surgeons at our 3 centers. The study protocol was approved by the local
institutional review boards at each study center and written informed consent was obtained from all participants. Tissue was evaluated for cautery artifacts, distorted tissue orientation and fragmented tissue by 1 anatomical pathologist at each institution. RESULTS The learning curve for the resectoscope was generally mild since the hand motion is the same as for conventional resectoscopes, while the resectoscope translates the standard linear hand motion into an axial rotation. During all procedures no unexpected safety concerns were evident, there were no serious immediate postoperative complications and each TUR was finished successfully without the necessity for conversion to a standard resectoscope working element. In each case the tissue submitted for pathological evaluation was adequate and allowed a sufficient histological diagnosis. Surgeon satisfaction was generally high. In early cases an unpolished tungsten wire was used to construct the disposable loop, which occasionally led to the adhesion of tissue on the wire. Feedback from the surgical investigators led to reevaluation of the manufacture process.
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FIG. 3. TURBT using novel resectoscope. A, TURBT loop is placed on healthy-looking mucosa beside lesion. B and C, activating working element in standard linear fashion allows circular traveling of cutting loop beneath tumor base. D, tumor with its underlying muscle layer are scooped out and removed from bladder.
Subsequently the loop was remanufactured and polished with a honing technique, in which the tungsten wire loop was polished by mechanical rotation within a fine diamond paste. During the polishing process 3 grades of diamond pastes were used. Followup evaluation by scanning electron microscopy showed that the reformulated polished wires had fewer transversal defects that would likely contribute to tissue adherence. When using the resectoscope for TURBT, lateral resection at the base of the tumor enabled accurate depth of penetration into the bladder wall. In particular anterior/
FIG. 4. Novel resectoscope during TURP
dome tumors appeared to benefit from lateral resection because the ability to control resection depth was helpful when treating tumors in an area where it was important to avoid bladder perforation. During TURP the resectoscope facilitated dissection of the adenoma adjacent to the verumontanum and prostatovesical junction, which may decrease the risk of sphincteric damage and bladder neck injury. DISCUSSION The basic essential elements of endoscopic resectoscope are that it provides access to the prostate and bladder with optics that permit adequate visualization of the interior of the urinary tract, working elements to allow treatment as well as diagnosis and energy provided by laser or electrocautery to extirpate, destroy and cauterize tissue. The history of the landmark innovations in endoscopic treatment of the bladder and prostate includes the introduction of the cystoscope in 1877 by Nitze, the first use of electrocoagulation to destroy bladder tumors in 1910 by Beer and the introduction of the first resectoscope in 1926 by Stern.8 Although modern instrumentation has benefited from technological innovations in optics, materials and video assistance, no major innovations have been applied to the standard resectoscope since the significant improvements made by McCarthy to the Stern resectoscope in 193111 and by the introduction of continuous flow resectoscopes by Iglesias a quarter of a century ago in 1975.6 The Stern resectoscope consisted of an outer sheath that contained its various channels, including a water inlet, channels for its telescope and light carrier, and a working
NOVEL RESECTOSCOPE FOR TRANSURETHRAL RESECTION element composed of a cutting loop that used a bipolar current and was controlled manually by a rotating handle that required 2 hands to use and was in essence a gear mechanism that slid a tungsten wire back and forth through a recessed fenestra in the outer sheath.8 The Stern scope cut out a cylinder of tissue when a high frequency current was passed through it. To create cutting current a continuously alternating high power electrical sine wave was generated. Although it offered the advantage of removing rather than merely cauterizing tissue, it was difficult to engage tissue in the bladder with the wire recessed in the outer sheath. In 1931 Davis, who was an electrical engineer before entering the field of urology, combined the cutting current with a diathermy machine for hemostasis, thickened the tungsten wire cutting loop on the Stern resectoscope, making it less prone to breakage, and introduced the first dual action foot switch, allowing direct control of cutting or coagulating current.9,10 The 1931 McCarthy resectoscope vastly improved the Stern resectoscope.11 The McCarthy visual prostatic electrotome improved the visual field and magnification through modifications to the lens system, implemented a synthetic plastic, nonconductive Bakelite sheath, incorporated separate currents for coagulation and cautery, and modified the working element so that the cutting loop, a 2-handed rack and pinion style system, was positioned at the beaked tip of the instrument rather than in a recess at the bottom of the sheath, so that the cutting direction was toward instead of away from the instrument.8 The Bakelite resectoscope sheath made it possible to directly visualize and precisely control the movements of the cutting loop safely, even while current was applied, without electrical risk to the surgeon. In 1939 Nesbit standardized a TURP surgical technique, developing the steps necessary to safely remove large quantities of obstructive prostatic tissue by TUR and designing a spring trigger working element that permitted 1-handed resection.12,13 In 1975 Iglesias designed a resectoscope with a similar external spring loaded working element but he added a continuous flow sheath.6 The Iglesias resectoscope is the most popular resectoscope working element style used today. The Iglesias resectoscope dual sheath assembly has 2 fluid conduits, including a larger channel for inflow of irrigant that flows directly in front of the lens to permit superior endoscopic vision and a smaller outflow channel that is completely separated from the inflow channel and has its distal opening located at a different side in the beak of the sheath. The Iglesias resectoscope offered several advantages, including a working element that used the thumb and spring to do the actual cutting, electrode retraction into the sheath, allowing resection to be performed with 1 hand like the Nesbit device, and simultaneous irrigation and suction, which make it possible to avoid periodic interruption of resection to evacuate the bladder and maintain lower intravesical pressures to minimize systemic irrigant absorption. Common complications of early TURP included rectourethral fistula, incontinence, excessive bleeding, sepsis, stricture formation, bladder rupture, abscess formation and even electrocution.14 Recently Rassweiler et al summarized the peer reviewed literature on TURP complications during 3 subsequent periods, including early (1979 to 1993), intermediate (1994 to 1999) and recent (2000 to 2005) periods.5 They observed that the complication rates decreased during the periods but blood transfusion rates may be still up to 7% and
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TUR syndrome may occur in up to 1.1% of patients. However, newer technologies for BPH, such as laser ablation and bipolar current, have decreased these risks of transfusion and TUR syndrome.5,15,16 TURBT leads to complications in less then 10% of patients17,18 with bladder perforation 1 of the most common complications.3 In a contemporary series Nieder et al reported an intraoperative and postoperative complication rate of 5.8%.19 Six of 173 patients (3.5%) experienced bladder perforation, including 2 intraperitoneally and 4 extraperitoneally. In the current study we did not note any severe or unexpected complications. There were no bladder perforations during TURBT and several surgeons noted less bleeding than anticipated during TURP. However, the number of patients studied was small, blood loss was not formally recorded as a study outcome and future studies are required to evaluate outcomes and complications in larger settings. However, we believe that the novel working element and resection technique may decrease the number of complications, especially the incidence of bladder perforation and the need for blood transfusion. The availability of variably sized loops and lateral resection may permit better control over resection depth in the bladder wall, which could allow more accurate tumor staging and fewer bladder injuries. Furthermore, arterial blood supply to the prostate from the inferior vesical artery is delivered primarily via capsular branches that pierce the prostate at right angles and follow the reticular bands of stroma to supply the glandular tissue. Standard resectoscope cutting is oriented in the longitudinal axis parallel to the urethra and it is likely to induce bleeding from several arterial branches simultaneously. Conversely using a lateral rotational cutting axis could potentially facilitate intraoperative hemostasis by allowing surgeons to control bleeding from 1 arterial branch at a time. Also, by deeper lateral resection hemostasis may be achieved by early resection to deeper vascular trunks as opposed to resecting more superficially, where the blood supply has arborized into multiple vessels. We evaluated the safety, feasibility and efficacy of a new working element for transurethral resectoscopes. Learning curves were mild, no serious complications occurred and tissue submitted for pathological assessment was deemed adequate in every case. As a first human study, the trial was designed only to provide initial experience with the performance of the new loop, its operating characteristics and the learning curve involved in adapting to its use, and preliminary impressions of the possible advantages provided by lateral resection. The study was not designed as a comparative study and neither sample size calculations nor recorded data were meant to show the superiority or even the equivalence of the new loop to standard loop designs. Another limitation of the current study is that patient followup was too short to assess delayed complications such as urethral stricture or bladder neck contraction. Finally, although our study showed no technical safety or efficacy concerns, disease related end points such as uroflow and recurrence rates must be evaluated in future studies. Future, larger studies of the loop are being planned to better assess bladder tumor staging and perforation, blood loss and other complications during TURP, and continue to evaluate tumor locations for which the new loop provides an advantage compared to standard loops.
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CONCLUSIONS
12.
Initial evaluation of this novel resectoscope working element suggests that conversion from a linear to a rotational cutting motion is intuitive, permitting a shallow learning curve. This working element, which is approved for marketing in the United States and Europe, appears to be safe and effective for TURP and TURBT. It may provide advantages compared to existing designs, including safe resection at vulnerable areas of the bladder, such as the dome, and during TURP at the bladder neck and prostatic-urethral junction. Larger comparative studies permitting formal evaluation of the loop benefits and complication rates are anticipated.
13.
ACKNOWLEDGMENTS
18.
The novel resectoscope working element was developed at Roei Medical Technologies, Israel.
19.
Abbreviations and Acronyms BPH TUR TURBT TURP
⫽ ⫽ ⫽ ⫽
benign prostatic hyperplasia transurethral resection TUR of bladder tumor TUR of prostate
REFERENCES 1. 2.
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4.
5.
6.
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9. 10.
11.
Jemal A, Siegel R, Ward E, Murray T, Xu J and Thun MJ: Cancer statistics, 2007. CA Cancer J Clin 2007; 57: 43. Herr HW: The value of a second transurethral resection in evaluating patients with bladder tumors. J Urol 1999; 162: 74. Traxer O, Pasqui F, Gattegno B and Pearle MS: Technique and complications of transurethral surgery for bladder tumours. BJU Int 2004; 94: 492. Meigs JB, Mohr B, Barry MJ, Collins MM and McKinlay JB: Risk factors for clinical benign prostatic hyperplasia in a community-based population of healthy aging men. J Clin Epidemiol 2001; 54: 935. Rassweiler J, Teber D, Kuntz R and Hofmann R: Complications of transurethral resection of the prostate (TURP)— incidence, management, and prevention. Eur Urol 2006; 50: 969. Iglesias JJ, Sporer A, Gellman AC and Seebode JJ: New Iglesias resectoscope with continuous irrigation, simultaneous suction and low intravesical pressure. J Urol 1975; 114: 929. Yossepowitch O, Eliachar E, Sade D, DiTrolio JV and Baniel J: An innovative resectoscope for transurethral resection of bladder tumors and the prostate. J Urol, suppl., 2004; 171: 183, abstract V691. Herr HW: Early history of endoscopic treatment of bladder tumors from Grunfeld’s polypenkneipe to the SternMcCarthy resectoscope. J Endourol 2006; 20: 85. Davis T: A new cystoscope for retrograde fulguration. J Urol 1931; 26: 491. Davis T: Prostate operation. Prospects of the patient with prostatic disease in prostatectomy vs. resection. JAMA 1931; 2: 1674. McCarthy J: The management of prostatic obstructions by endoscopic revision. N Engl J Med 1932; 207: 305.
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16. 17.
Nesbit RM: Transurethral Prostatectomy. Springfield, Illinois: Charles C. Thomas 1943. Nesbit RM: A history of transurethral prostatectomy. Rev Mex Urol 1975; 35: 349. Caulk J and Patton J: The influence of the type of current upon the post-operative complications in transurethral surgery. J Urol 1933; 30: 537. Malek RS, Kuntzman RS and Barrett DM: High power potassium-titanyl-phosphate laser vaporization prostatectomy. J Urol 2000; 163: 1730. Kaplan SA: Expanding the role of photoselective vaporization of the prostate. Rev Urol, suppl., 2006; 3: S3. Collado A, Chéchile GE, Salvador J and Vicente J: Early complications of endoscopic treatment for superficial bladder tumors. J Urol 2000; 164: 1529. Kondas J and Szentgyorgyi E: Transurethral resection of 1250 bladder tumours. Int Urol Nephrol 1992; 24: 35. Nieder AM, Meinbach DS, Kim SS and Soloway MS: Transurethral bladder tumor resection: intraoperative and postoperative complications in a residency setting. J Urol 2005; 174: 2307.
EDITORIAL COMMENT These authors present their multicenter pilot experience with a novel side firing resectoscope and conclude that this loop may increase the control of depth of penetration during TURBT and distal resection during TURP. As the authors acknowledge, the impetus for this novel resectoscope is the need to decrease the incidence of under staging, bladder perforation and sphincteric injury during these 2 common urological procedures. Unfortunately there have been no major advances in bladder cancer survival in the last 25 years. Urothelial carcinoma of the bladder remains a lethal disease for multiple reasons,1 one of which is that TURBT is notorious for under staging the true nature of the disease (reference 2 in article).2 In fact, because of the high incidence of under staging, recent international guidelines recommend that patients with high grade or T1 lesions undergo repeat TURBT.3 Could this novel loop allow better identification and stratification of patients at high risk with T1 or T2 disease secondary to improved pathological analyses without cauterization artifact? Only prospective studies would provide that information and determine whether this loop becomes commonplace in urological practice. Alan M. Nieder Department of Urology University of Miami Miller School of Medicine Miami, Florida 1.
Araki M, Nieder AM, Manoharan M, Yang Y and Soloway MS: Lack of progress in early diagnosis of bladder cancer. Urology 2007; 69: 270. 2. Dutta SC, Smith JA Jr, Shappell SB, Coffey CS, Chang SS and Cookson MS: Clinical under staging of high risk nonmuscle invasive urothelial carcinoma treated with radical cystectomy. J Urol 2001; 166: 490. 3. Nieder AM, Brausi M, Lamm D, O’Donnell M, Tomita K, Woo H et al: Management of stage T1 tumors of the bladder: International Consensus Panel. Urology 2005; 66: 108.
Purpose: Transurethral bladder tumor resection is associated with imperfect clinical staging and incomplete tumor removal. Transurethral prostate resection may be complicated by inadvertent damage to the urinary sphincter, bladder neck and trigone. We performed a multicenter pilot and feasibility study of a novel working element for resectoscopes designed to improve the efficacy and safety of transurethral endoscopic surgery. Materials and Methods: An innovative working element for resectoscopes was developed to convert the standard in/out linear/axial movement at the handgrip into a side-to-side, bidirectional, lateral rotating motion. The device is compatible with current optical technology and conventional electrocautery generators, and it has been granted marketing approval. It consists of variably sized cutting loops designed for transurethral resection of bladder tumors and the prostate. To date 80 patients with bladder cancer (38) or benign prostatic hyperplasia (42) have undergone surgery with this instrument at our 3 clinical sites. Results: No safety concerns were evident. When used during transurethral bladder tumor resection, lateral resection at the base of the tumor enabled accurate depth of penetration into the bladder wall, which may decrease the risk of bladder perforation and improve pathological assessment of tumor invasion. During transurethral prostate resection this novel tool facilitated dissection of adenoma adjacent to the verumontanum and prostatovesical junction, which may decrease the risk of sphincteric damage and bladder neck injury. Conclusions: A novel resectoscope is currently under prospective clinical investigation to establish its surgical and pathological efficacy, ease of use and side effect profile. Current data suggest that the learning curve is mild, its use is safe and it provides distinct advantages when used for transurethral resection of bladder tumors and the prostate. Key Words: prostate, transurethral resection of prostate, prostatic hyperplasia, bladder neoplasms, endoscopy
ransurethral resection is the cornerstone of surgical management for bladder cancer and BPH. In 2007 bladder cancer newly affected 67,000 Americans1 with most lesions diagnosed at a superficial, noninvasive stage. TUR is an integral part of the diagnostic evaluation of all bladder tumors and it represents the standard surgical therapy for noninvasive bladder cancer. However, this procedure is associated with imperfect clinical staging, incomplete tumor removal2 and perioperative complications such as bladder perforation and bleeding.3 The prevalence of BPH is about 20% in 40 to 70-yearold men.4 Despite the introduction of ablative and less invasive alternatives TURP remains the gold standard for surgical therapy for BPH and it is one of the most frequently performed operations in urology. Of participants
T
Submitted for publication April 24, 2007. Study received approval from local institutional review boards at each study center. * Correspondence and requests for reprints: Department of Urology, David Geffen School of Medicine at University of California-Los Angeles, 10833 Le Conte Ave., Room B7-298A CHS, Los Angeles, California 90025-1738 (telephone: 310-206-2436; FAX: 310-2064082; e-mail: [email protected]). † Financial interest and/or other relationship with Roei Medical Technologies Ltd.
0022-5347/07/1786-2331/0 THE JOURNAL OF UROLOGY® Copyright © 2007 by AMERICAN UROLOGICAL ASSOCIATION
in a population based study the percent of men undergoing TURP in the age groups 40 to 49, 50 to 59 and 60 to 70 was 0.8%, 4.5% and 8.5%, respectively.4 Like TURBT, TURP is associated with well-known morbidities at a rate of up to 30%, including TUR syndrome, bleeding, infection, urinary retention, incontinence, urethral stricture, bladder neck stenosis and retrograde ejaculation.5 Standard resectoscopes for transurethral resection comprise an optical lens, a sheath, an obturator, a working element and a disposable cutting loop. The most significant advance in resectoscope equipment was achieved more than 30 years ago with the introduction of the Iglesias working element into clinical practice.6 Recently a new working element for TUR was developed that converts the standard in/out linear/axial movement at the handgrip into a side-to-side, bidirectional, lateral rotating motion that allows a circular side-to-side cutting motion. Due to its unique design it may decrease some risks of TUR, such as bladder perforation, enable more adequate tissue assessment with regard to tumor invasion and facilitate dissection of BPH adjacent to the verumontanum and prostatovesical junction. We report what is to our knowledge the first clinical assessment of this novel resectoscope in a multicenter pilot and feasibility study performed to determine its clinical applicability.
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Vol. 178, 2331-2336, December 2007 Printed in U.S.A. DOI:10.1016/j.juro.2007.08.042
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NOVEL RESECTOSCOPE FOR TRANSURETHRAL RESECTION
MATERIALS AND METHODS Equipment and Technique A novel resectoscope for TURBT and TURP was developed. The resectoscope includes a telescope, a working element, a sheath, disposable cutting loops and high frequency cables. It is similar to other Food and Drug Administration and CE marking cleared resectoscopes. Specifically the resectoscope is designed to use the same electrocautery generators and it is similarly compatible with various resectoscope accessories. The cutting loops are fabricated from the same materials as Karl Storz™ and ACMI™ resectoscopes. The safety and feasibility of the novel resectoscope were previously tested in a porcine animal model.7 In these preclinical studies, which were performed before testing in humans and reported in 2004 at the annual meeting of the American Urological Association, no adverse events or device malfunction were observed. None of the test animals experienced electrical burns, no effects were noted on animal vital signs and an assessment of the resected bladders revealed clean resection craters without evidence of perforation. The principal technological differences between the current resectoscope and others are in the design of the working element and cutting loops that translate the axial maneuver at the handgrip into a lateral rotational movement of the cutting loop. The loop is oriented parallel to the resectoscope shaft and it lies entirely in the sheath at its resting position (fig. 1, A). The proximal handgrip of the resectoscope working element is designed to allow circular, side-to-side cutting motion of the cutting loop independent of the resectoscope sheath. In its passive version pressing the thumb grip against the index finger allows the loop to extend outside of the sheath (linear movement), followed by rotation in a plane perpendicular to the shaft (fig. 1). The loop can then be moved in a clockwise or counterclockwise course depending on whether the thumb is being pressed or released against the index finger. In contrast, other resectoscopes accomplish a cutting motion in tissue using electrode rotation to move the cutting tool, eg as in the Karl Storz resectoscope, or rotation of the entire working element and telescope independent of the resectoscope sheath, eg as in the ACMI resectoscope. The working element and loops of the novel resectoscope are compatible with a standard 24Fr resectoscope sheath, and conventional monopolar cutting and cautery electrical settings. Small, medium and large loops are available for TURBT and TURP, correspondingly (fig. 2). For TURBT the small loop would generally be used. The loop is pushed outside of the sheath and placed at level of healthy mucosa lateral to the tumor. Turning the loop in a circular axis while activating the cutting current allows the lesion to be scooped out with its underlying base as a complete, intact specimen (fig. 3). The depth of penetration beneath the tumor is preset by the cutting wire arch, ie the distance between its tip and the rod. This distance is set at 3.4 mm, thereby allowing resection into the muscle layer while avoiding bladder perforation. For larger tumors resection is done in several cuts. The theory of this design is to provide pathologists with a 3-dimensionally oriented specimen (tumor-submucosa-muscle) and potentially allow better clinical staging of the cancer. Finally, hemostasis is achieved by allowing the loop to retract back into the sheath, approx-
FIG. 1. Working element dual motion technique with passive design. A, at resting position cutting loop is fully retracted inside resectoscope sheath. B, forwarding working element thumb grip against index finger allows partial or full extension of cutting loop outside of sheath. Loop is oriented parallel to the resectoscope shaft. C, further pressing of thumb grip activates second mechanism enabling side-to-side rotation of cutting loop, which can be moved in clockwise or counterclockwise fashion.
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FIG. 2. Small, medium and large loops are available for TURBT and TURP, correspondingly. Dimensions are shown in mm. TURBT/P, TUR of bladder tumor or prostate.
imating the optic to the tissue and identifying and securing any bleeders by activating cautery. TURP is performed generally using a large loop, and standard cutting and cautery settings (fig. 4). Resection is started at the bladder neck, as with the standard Nesbit TURP technique. The circular axis of resection is particularly useful in patients with a large median lobe because the loop is not extended beyond the adenoma blindly into the bladder, potentially minimizing the risk of inadvertent damage to the orifices. Adenoma removal can then be safely continued in proximal-to-distal fashion. As long as the resectoscope shaft maintains its static position in the urethra to the level of the verumontanum, the circular cutting axis prevents inadvertent damage to the sphincter. Pilot Study Our pilot study (ClinicalTrials.gov Identifier: NCT00303654) was designed to investigate the safety, feasibility and efficacy of the resectoscope with regard to tissue quality, surgeon satisfaction and perioperative complications. The study accrued 80 patients who underwent TUR for bladder cancer (38) or BPH (42). TUR was performed by 4 surgeons at our 3 centers. The study protocol was approved by the local
institutional review boards at each study center and written informed consent was obtained from all participants. Tissue was evaluated for cautery artifacts, distorted tissue orientation and fragmented tissue by 1 anatomical pathologist at each institution. RESULTS The learning curve for the resectoscope was generally mild since the hand motion is the same as for conventional resectoscopes, while the resectoscope translates the standard linear hand motion into an axial rotation. During all procedures no unexpected safety concerns were evident, there were no serious immediate postoperative complications and each TUR was finished successfully without the necessity for conversion to a standard resectoscope working element. In each case the tissue submitted for pathological evaluation was adequate and allowed a sufficient histological diagnosis. Surgeon satisfaction was generally high. In early cases an unpolished tungsten wire was used to construct the disposable loop, which occasionally led to the adhesion of tissue on the wire. Feedback from the surgical investigators led to reevaluation of the manufacture process.
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NOVEL RESECTOSCOPE FOR TRANSURETHRAL RESECTION
FIG. 3. TURBT using novel resectoscope. A, TURBT loop is placed on healthy-looking mucosa beside lesion. B and C, activating working element in standard linear fashion allows circular traveling of cutting loop beneath tumor base. D, tumor with its underlying muscle layer are scooped out and removed from bladder.
Subsequently the loop was remanufactured and polished with a honing technique, in which the tungsten wire loop was polished by mechanical rotation within a fine diamond paste. During the polishing process 3 grades of diamond pastes were used. Followup evaluation by scanning electron microscopy showed that the reformulated polished wires had fewer transversal defects that would likely contribute to tissue adherence. When using the resectoscope for TURBT, lateral resection at the base of the tumor enabled accurate depth of penetration into the bladder wall. In particular anterior/
FIG. 4. Novel resectoscope during TURP
dome tumors appeared to benefit from lateral resection because the ability to control resection depth was helpful when treating tumors in an area where it was important to avoid bladder perforation. During TURP the resectoscope facilitated dissection of the adenoma adjacent to the verumontanum and prostatovesical junction, which may decrease the risk of sphincteric damage and bladder neck injury. DISCUSSION The basic essential elements of endoscopic resectoscope are that it provides access to the prostate and bladder with optics that permit adequate visualization of the interior of the urinary tract, working elements to allow treatment as well as diagnosis and energy provided by laser or electrocautery to extirpate, destroy and cauterize tissue. The history of the landmark innovations in endoscopic treatment of the bladder and prostate includes the introduction of the cystoscope in 1877 by Nitze, the first use of electrocoagulation to destroy bladder tumors in 1910 by Beer and the introduction of the first resectoscope in 1926 by Stern.8 Although modern instrumentation has benefited from technological innovations in optics, materials and video assistance, no major innovations have been applied to the standard resectoscope since the significant improvements made by McCarthy to the Stern resectoscope in 193111 and by the introduction of continuous flow resectoscopes by Iglesias a quarter of a century ago in 1975.6 The Stern resectoscope consisted of an outer sheath that contained its various channels, including a water inlet, channels for its telescope and light carrier, and a working
NOVEL RESECTOSCOPE FOR TRANSURETHRAL RESECTION element composed of a cutting loop that used a bipolar current and was controlled manually by a rotating handle that required 2 hands to use and was in essence a gear mechanism that slid a tungsten wire back and forth through a recessed fenestra in the outer sheath.8 The Stern scope cut out a cylinder of tissue when a high frequency current was passed through it. To create cutting current a continuously alternating high power electrical sine wave was generated. Although it offered the advantage of removing rather than merely cauterizing tissue, it was difficult to engage tissue in the bladder with the wire recessed in the outer sheath. In 1931 Davis, who was an electrical engineer before entering the field of urology, combined the cutting current with a diathermy machine for hemostasis, thickened the tungsten wire cutting loop on the Stern resectoscope, making it less prone to breakage, and introduced the first dual action foot switch, allowing direct control of cutting or coagulating current.9,10 The 1931 McCarthy resectoscope vastly improved the Stern resectoscope.11 The McCarthy visual prostatic electrotome improved the visual field and magnification through modifications to the lens system, implemented a synthetic plastic, nonconductive Bakelite sheath, incorporated separate currents for coagulation and cautery, and modified the working element so that the cutting loop, a 2-handed rack and pinion style system, was positioned at the beaked tip of the instrument rather than in a recess at the bottom of the sheath, so that the cutting direction was toward instead of away from the instrument.8 The Bakelite resectoscope sheath made it possible to directly visualize and precisely control the movements of the cutting loop safely, even while current was applied, without electrical risk to the surgeon. In 1939 Nesbit standardized a TURP surgical technique, developing the steps necessary to safely remove large quantities of obstructive prostatic tissue by TUR and designing a spring trigger working element that permitted 1-handed resection.12,13 In 1975 Iglesias designed a resectoscope with a similar external spring loaded working element but he added a continuous flow sheath.6 The Iglesias resectoscope is the most popular resectoscope working element style used today. The Iglesias resectoscope dual sheath assembly has 2 fluid conduits, including a larger channel for inflow of irrigant that flows directly in front of the lens to permit superior endoscopic vision and a smaller outflow channel that is completely separated from the inflow channel and has its distal opening located at a different side in the beak of the sheath. The Iglesias resectoscope offered several advantages, including a working element that used the thumb and spring to do the actual cutting, electrode retraction into the sheath, allowing resection to be performed with 1 hand like the Nesbit device, and simultaneous irrigation and suction, which make it possible to avoid periodic interruption of resection to evacuate the bladder and maintain lower intravesical pressures to minimize systemic irrigant absorption. Common complications of early TURP included rectourethral fistula, incontinence, excessive bleeding, sepsis, stricture formation, bladder rupture, abscess formation and even electrocution.14 Recently Rassweiler et al summarized the peer reviewed literature on TURP complications during 3 subsequent periods, including early (1979 to 1993), intermediate (1994 to 1999) and recent (2000 to 2005) periods.5 They observed that the complication rates decreased during the periods but blood transfusion rates may be still up to 7% and
2335
TUR syndrome may occur in up to 1.1% of patients. However, newer technologies for BPH, such as laser ablation and bipolar current, have decreased these risks of transfusion and TUR syndrome.5,15,16 TURBT leads to complications in less then 10% of patients17,18 with bladder perforation 1 of the most common complications.3 In a contemporary series Nieder et al reported an intraoperative and postoperative complication rate of 5.8%.19 Six of 173 patients (3.5%) experienced bladder perforation, including 2 intraperitoneally and 4 extraperitoneally. In the current study we did not note any severe or unexpected complications. There were no bladder perforations during TURBT and several surgeons noted less bleeding than anticipated during TURP. However, the number of patients studied was small, blood loss was not formally recorded as a study outcome and future studies are required to evaluate outcomes and complications in larger settings. However, we believe that the novel working element and resection technique may decrease the number of complications, especially the incidence of bladder perforation and the need for blood transfusion. The availability of variably sized loops and lateral resection may permit better control over resection depth in the bladder wall, which could allow more accurate tumor staging and fewer bladder injuries. Furthermore, arterial blood supply to the prostate from the inferior vesical artery is delivered primarily via capsular branches that pierce the prostate at right angles and follow the reticular bands of stroma to supply the glandular tissue. Standard resectoscope cutting is oriented in the longitudinal axis parallel to the urethra and it is likely to induce bleeding from several arterial branches simultaneously. Conversely using a lateral rotational cutting axis could potentially facilitate intraoperative hemostasis by allowing surgeons to control bleeding from 1 arterial branch at a time. Also, by deeper lateral resection hemostasis may be achieved by early resection to deeper vascular trunks as opposed to resecting more superficially, where the blood supply has arborized into multiple vessels. We evaluated the safety, feasibility and efficacy of a new working element for transurethral resectoscopes. Learning curves were mild, no serious complications occurred and tissue submitted for pathological assessment was deemed adequate in every case. As a first human study, the trial was designed only to provide initial experience with the performance of the new loop, its operating characteristics and the learning curve involved in adapting to its use, and preliminary impressions of the possible advantages provided by lateral resection. The study was not designed as a comparative study and neither sample size calculations nor recorded data were meant to show the superiority or even the equivalence of the new loop to standard loop designs. Another limitation of the current study is that patient followup was too short to assess delayed complications such as urethral stricture or bladder neck contraction. Finally, although our study showed no technical safety or efficacy concerns, disease related end points such as uroflow and recurrence rates must be evaluated in future studies. Future, larger studies of the loop are being planned to better assess bladder tumor staging and perforation, blood loss and other complications during TURP, and continue to evaluate tumor locations for which the new loop provides an advantage compared to standard loops.
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NOVEL RESECTOSCOPE FOR TRANSURETHRAL RESECTION
CONCLUSIONS
12.
Initial evaluation of this novel resectoscope working element suggests that conversion from a linear to a rotational cutting motion is intuitive, permitting a shallow learning curve. This working element, which is approved for marketing in the United States and Europe, appears to be safe and effective for TURP and TURBT. It may provide advantages compared to existing designs, including safe resection at vulnerable areas of the bladder, such as the dome, and during TURP at the bladder neck and prostatic-urethral junction. Larger comparative studies permitting formal evaluation of the loop benefits and complication rates are anticipated.
13.
ACKNOWLEDGMENTS
18.
The novel resectoscope working element was developed at Roei Medical Technologies, Israel.
19.
Abbreviations and Acronyms BPH TUR TURBT TURP
⫽ ⫽ ⫽ ⫽
benign prostatic hyperplasia transurethral resection TUR of bladder tumor TUR of prostate
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Jemal A, Siegel R, Ward E, Murray T, Xu J and Thun MJ: Cancer statistics, 2007. CA Cancer J Clin 2007; 57: 43. Herr HW: The value of a second transurethral resection in evaluating patients with bladder tumors. J Urol 1999; 162: 74. Traxer O, Pasqui F, Gattegno B and Pearle MS: Technique and complications of transurethral surgery for bladder tumours. BJU Int 2004; 94: 492. Meigs JB, Mohr B, Barry MJ, Collins MM and McKinlay JB: Risk factors for clinical benign prostatic hyperplasia in a community-based population of healthy aging men. J Clin Epidemiol 2001; 54: 935. Rassweiler J, Teber D, Kuntz R and Hofmann R: Complications of transurethral resection of the prostate (TURP)— incidence, management, and prevention. Eur Urol 2006; 50: 969. Iglesias JJ, Sporer A, Gellman AC and Seebode JJ: New Iglesias resectoscope with continuous irrigation, simultaneous suction and low intravesical pressure. J Urol 1975; 114: 929. Yossepowitch O, Eliachar E, Sade D, DiTrolio JV and Baniel J: An innovative resectoscope for transurethral resection of bladder tumors and the prostate. J Urol, suppl., 2004; 171: 183, abstract V691. Herr HW: Early history of endoscopic treatment of bladder tumors from Grunfeld’s polypenkneipe to the SternMcCarthy resectoscope. J Endourol 2006; 20: 85. Davis T: A new cystoscope for retrograde fulguration. J Urol 1931; 26: 491. Davis T: Prostate operation. Prospects of the patient with prostatic disease in prostatectomy vs. resection. JAMA 1931; 2: 1674. McCarthy J: The management of prostatic obstructions by endoscopic revision. N Engl J Med 1932; 207: 305.
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EDITORIAL COMMENT These authors present their multicenter pilot experience with a novel side firing resectoscope and conclude that this loop may increase the control of depth of penetration during TURBT and distal resection during TURP. As the authors acknowledge, the impetus for this novel resectoscope is the need to decrease the incidence of under staging, bladder perforation and sphincteric injury during these 2 common urological procedures. Unfortunately there have been no major advances in bladder cancer survival in the last 25 years. Urothelial carcinoma of the bladder remains a lethal disease for multiple reasons,1 one of which is that TURBT is notorious for under staging the true nature of the disease (reference 2 in article).2 In fact, because of the high incidence of under staging, recent international guidelines recommend that patients with high grade or T1 lesions undergo repeat TURBT.3 Could this novel loop allow better identification and stratification of patients at high risk with T1 or T2 disease secondary to improved pathological analyses without cauterization artifact? Only prospective studies would provide that information and determine whether this loop becomes commonplace in urological practice. Alan M. Nieder Department of Urology University of Miami Miller School of Medicine Miami, Florida 1.
Araki M, Nieder AM, Manoharan M, Yang Y and Soloway MS: Lack of progress in early diagnosis of bladder cancer. Urology 2007; 69: 270. 2. Dutta SC, Smith JA Jr, Shappell SB, Coffey CS, Chang SS and Cookson MS: Clinical under staging of high risk nonmuscle invasive urothelial carcinoma treated with radical cystectomy. J Urol 2001; 166: 490. 3. Nieder AM, Brausi M, Lamm D, O’Donnell M, Tomita K, Woo H et al: Management of stage T1 tumors of the bladder: International Consensus Panel. Urology 2005; 66: 108.