- Email: [email protected]
The evolution and progress of ureteroscopy
Urol Clin N Am 31 (2004) 5–13
The evolution and progress of ureteroscopy William K. Johnston III, MDa, Roger K. Low, MDb, Sakti Das, MDb,* a
Minimally Invasive Urology, University of Michigan, 1500 E. Medical Center Drive, Taubman Center 2916, Ann Arbor, MI 48109-0330, USA b Department of Urology, University of California, Davis, 4860 Y Street, Suite 3500, Sacramento, CA 95817, USA
The evolution of ureteroscopy is a beguiling saga of human ingenuity and relentless pursuit for improvement. Historically, it started serendipitously in 1912 when Hugh Hampton Young inadvertently introduced a 12F pediatric cystoscope into a massively dilated right ureter of a child who had posterior urethral valves and found himself gazing at the renal pelvis. While in the renal pelvis, Young attempted unsuccessfully to witness ‘‘jets of urine’’ from the papillae [1]. His discovery humbly remained torpid within a thorough review article devoted to congenital valvular obstruction of the prostatic urethra that was not published until 1929 [1]. Fiberoptics Documented advances in ureteroscopy would lay dormant over the next 30 years until fiberoptic technology was integrated into medical instruments and allowed image transmission as first developed by Curtiss et al [2]. The technology that allowed fiberoptics was developed nearly 100 years earlier. In 1841, Daniel Colladon at the University of Geneva made the first step toward the development of fiberoptics by disproving the belief that light only traveled in a straight line. He demonstrated that light could be trapped within a transparent medium and carried by internal reflection. Colladon publicly demonstrated ‘‘light guiding’’ * Corresponding author. 1890 Via Ferrari, Lafayette, CA 94549. E-mail address: [email protected] (S. Das).
during his lectures [3]. Jacques Babinet, a French specialist in optics, extended Colladon’s principles by demonstrating guiding light along bent glass rods [4]. The first suggestion of the technology behind contemporary fiberoptics originated in the 1840s with Colladon and Babinet’s work. Yet, at that time, they viewed light guiding as nothing more than a ‘‘parlor trick’’ [4]. Colladon’s work has been shadowed historically by a more well-known and gallant demonstration of light guiding by Professor John Tyndall. In 1854, Tyndall demonstrated that light could be trapped within water and carried by internal reflection, much as Colladon had 13 years prior. Tyndall performed light guiding to the amazement of his assembled peers. His experiment boldly involved cutting a hole in the roof of his building for the installation of an open-top container filled with water. The room below was fitted with a washtub. In complete darkness waited an august audience composed of members of the Royal Institution of Great Britain. He unplugged a hole in the side of the container and allowed the water to curve below into the basin, carrying with it the sunlight trapped with the stream (Fig. 1) [5]. Two patents expanding on Colladon’s work on the internal reflection phenomenon were obtained in 1927 and 1930 by Baird and Hansell, respectively. In these patents, the first applications were provided for fiber bundles providing image transmission through internal reflection. Baird described an array of parallel glass rods or hollow tubes to carry an image in a mechanical television. Hansell introduced the principles of image bundling (Fig. 2) [6,7].
0094-0143/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/S0094-0143(03)00100-9
6
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
veloping a new type of fiber covered by glass (glass clad) that dramatically protected the reflective surface from contamination and that greatly reduced image mixing between adjacent fibers (Fig. 3). Curtiss combined a large number of fibers in a group to form a coherent bundle. The fibers were fused together at their ends to preserve orientation but were allowed to move individually along the length within the loose outer sheath. Hirschowitz tested the first gastroscope in 1957 on himself and the following day diagnosed a stomach ulcer under direct view in one of his patients [8]. Curtiss and Hirschowitz introduced the first fiberscope that stimulated interest in the development of new endoscopic instruments for other endoscopic applications [2,9]. Fig. 1. Although Colladon in 1841 initially described how light can be trapped within a medium (water) and can travel by internal reflection along a curved path, Tyndall performed a gallant demonstration of light guiding to the amazement of the Royal Institution of Great Britain in 1854.
The fiber bundles of Baird and Hansell were put to clinical use in the early 1950s. Basil Hirschowitz, a gastroenterologist at the University of Michigan, imagined using fiberoptics to develop a flexible gastroscope. He recruited a sophomore physics student, Lawrence Curtiss, to join him in his quest [8]. By 1957, they had combined their respective talents and described the first clinical experience with a new instrument using fiberoptic technology that allowed flexible gastroscopy. Curtiss made a landmark contribution by de-
Fig. 2. Fiberoptics integrated into fiber bundles allow for image transmission while maintaining image position.
First flexible endoscope (ureteroscope) By 1960, physicians in other specialties began to experiment with the 9F flexible fiberscope. In 1960, Marshall reported the first use of the new 9F flexible fiberscope to inspect the renal pelvis during an open operation and completed the first flexible ureteroscopy. A ureterotomy was made 5 cm below the renal pelvis to inspect for renal calculi [10]. Subsequently, in 1962, Marshall’s associates (McGovern and Walzak) completed the first transurethral flexible ureteroscopy with the 9F fiberscope. They passed the ureteroscope through a 26F McCarthy endoscope 10 cm up the left ureter to visualize a ureteral stone [10]. In 1968, Takagi et al [11] described the use of a 70cm, 8F fiberoptic endoscope to visualize the renal pelvis and papillae in cadavers and subsequently in patients during surgery. They were able to share their findings through photographs of the renal papillae with their newly developed endoscope [11]. Takagi’s group explored applications of the
Fig. 3. Using fiberoptics, light travels by internal reflection. Light constantly reflects from the cladding with a lower index of reflection than the core with a high index of reflection. The cladding does not absorb any light, allowing propagation of the light or image.
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
endoscope not only in the urinary tract but also in the biliary tract and spinal canal. Within the biliary tract, they noted difficulty manipulating the tip. Accordingly, they passed the endoscope through a 12F venous catheter to provide rigidity and transmitted torque. This technique allowed them to persuade the tip in the desired direction, establishing the importance of developing a deflectable tip endoscope [11]. Upper urinary tract abnormalities could now be visualized with the new flexible endoscope; treatment would be the next logical step pursued by researchers. In 1966, Bush et al [12] entertained the idea of using argon lasers to improve illumination and possibly treat upper tract tumors and bleeding through an ureteroscope. They demonstrated the effects of focused argon laser light on renal calculi placed in the pelvis of a cow’s kidney. Further evidence of the effectiveness of ureteroscopy was displayed by Takayasu et al [13] in the early 1970s when, for the first time, movies of the upper tract were completed. Takayasu and coworkers predicted that the fiberscope, with further refinement of accessories, would ‘‘contribute tremendously to the progress of medicine and happiness of mankind’’ [13]. Rigid ureteroscopy Surprisingly, the development and first purposeful use of rigid ureteroscopy in 1977 by Goodman [14] lagged initial reports of flexible ureteroscopy by nearly 10 years. Goodman reported on three cases in which an 11F pediatric cystoscope was used to manage ureteral problems. In one case, the cystoscope was used to inspect the ureter to the ureteropelvic junction; in a second patient, a biopsy specimen of a ureteral mucosal irregularity was obtained; in a third patient, fulguration of a ureteral tumor was performed. At the time, researchers were concerned about the morbidity of ureteroscopy and recommended using ‘‘greatest gentleness’’ to avoid ureteral perforation or damage [14]. In 1978, Lyon et al [15] described a new technique of ureteral dilation using Jewitt sounds passed adjacent to a cystoscope, transurethrally. This technique allowed distal ureteroscopy in women for management of transitional cell carcinoma while minimizing the risk of ureteral trauma or perforation. The following year, Lyon’s group described rigid ureteroscopy in men. They used a 13F juvenile cystoscope of standard adult length. The procedure involved passing specially designed flexible
7
ureteral dilators through a 25.5F cystoscope. Next, a 13F juvenile cystoscope of standard adult length was introduced into the ureter. To perform coagulation or basketing under direct vision, they proposed using a 14.5 juvenile resectoscope and a juvenile cystoscopic sheath, respectively. The length of the instrument limited exploration beyond 4 cm proximally [16]. Nonetheless, their work set the stage for expanding ureteroscopic applications. Stone manipulation Before 1981, urologists treated ureteral calculi with open ureterolithotomy or by using blind tactile manipulation. Both techniques were challenging owing to the variable success of blind endoscopic manipulation and the morbidity associated with the open procedure. Furthermore, distal ureteral calculi were particularly difficult to reach through an open approach. Accordingly, in 1981, the first transurethral ureteroscopy with stone basketing under direct vision was described by Das [17]. These advancements demonstrated the usefulness and ease of rigid ureteroscopy in men and women, opening the doors for further refinement and advancement. Initially, safety concerns continued to hinder the growth and widespread use of ureteroscopy. The greatest uneasiness centered on the size of the instruments. This concern was alleviated by the development of a smaller diameter rigid ureteroscope based on work completed by Hopkins in 1960. Hopkins introduced an optical system with cylindrical rodlike lenses [18]. The main purpose was to convey optical images for endoscopes along glass rods. Previous endoscopes relied on a hollow tube with serial aligned lenses to transmit an image along the tube through air. Such a system depended on perfectly aligned lenses to avoid loss of the image. In Hopkins’ system, images traveled along glass rods with a higher refractive index and a more durable construction than previous systems. This design allowed the development of smaller outer diameter endoscopes and expanded working and irrigating channels. Up to this point in time, ureteroscopy in women had been well described [15], but progress and routine use in men had been delayed by limitations of the instruments. Richard Wolf Medical Instruments (Vernon Hills, IL) developed the first endoscope specifically intended for ureteroscopy. They combined the diametric size of a 13F pediatric cystoscope with the length of a standard adult
8
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
cystoscope (23 cm). Lyon and associates [16] reported the first use of the new longer ureteroscope in men in 1979. Huffman et al [19] described their initial experience using the new ureteroscope in the treatment of 16 distal ureteral calculi. They successfully removed the stones in 69% of the cases using a similar technique described by Lyon and previously used by Das to remove a distal ureteral calculus [16,17]. Despite the success of the newer smaller diameter long ureteroscope, its use was still limited to the distal ureter. Karl Storz Endoscopy (Tuttlingen, Germany), led by pioneers Perez-Castro and MartinezPiniero, entered the arena of endoscopy with the introduction of a longer ureteroscope (50 cm) that could reach the renal pelvis [20]. This new design allowed diagnostic ureteroscopy, biopsy, direct viewing of stone manipulation, and coagulation. Equally important, this work prompted further development and refinement of the long rigid ureteroscope with different lengths (25–54 cm), interchangeable lenses (0–70 degrees), and different sizes (9–16F). The new ‘‘ureteropyeloscopes’’ supported working channels measuring 5F and accommodated flexible instruments such as wires, stone baskets, biopsy forceps, and brushes. In 1983, Huffman et al [21] reported their initial experience using the new ureteroscopes throughout the upper tract to diagnose, treat, and followup upper tract tumors and to extract upper tract calculi. The findings confirmed the safety and success of the longer rigid ureteroscope. This group reported on 31 patients with upper tract urothelial tumors diagnosed and treated through a transurethral endoscopic approach [22]. In addition, Huffman et al [23] reported their initial experience with ureteroscopic ultrasonic lithotripsy. The stone was secured in place with a basket advanced through the working channel. The telescope was removed, which allowed passage of the ultrasonic lithotriptor for fragmentation. Fluoroscopic imaging confirmed contact between the stone and lithotriptor [23]. The success of this technique was later confirmed by others [24] who performed stone manipulation of the proximal ureter and pelvis [25]. The rigid ureteropyeloscope had limitations, specifically in patients who had a torturous or narrowed ureter. Although the rigid ureteroscope provided upper pole visualization, it was difficult to enter the lower pole in many patients. It became apparent that rigid and flexible ureteroscopy needed to be combined to expand access. The difficulty in reaching intrarenal territory for the treatment of lesions and calculi
renewed interest in further developing the flexible ureteroscope. Flexible tip ureteroscopy In 1983, Bagley et al [26] described use of the new 55- and 80-cm flexible tip pyeloscope. The tip deflected 160 degrees in one direction and 90 degrees in the opposite direction. The flexible ureteroscope was small enough to fit through the sheath of the rigid telescope after removing the telescope. Passing the flexible ureteroscope through the rigid sheath alleviated two problems previously encountered with flexible ureteroscopy. One of these problems—difficulty in maneuvering the flexible ureteroscope in the renal pelvis—had been overcome in the past with placement of a polytetrafluoroethylene guide sheath to support the scope within the ureter [27]. The other problem—irrigation—had been improved marginally by promoting diuresis or by flushing through an outer sheath or ureteral catheter. With use of the rigid ureteroscope with two working channels, the flexible ureteroscope could wind through narrowed areas and provide panoramic visualization. Irrigation through the other channel distended the ureter and maintained visualization, alleviating both problems. Earlier flexible ureteroscopes relied on passive deflection as they were passed through the ureter. With the introduction of the rigid ureteroscope, the flexible ureteroscope could be passed through the rigid ureteroscope or, eventually, over a guidewire; however, this technique was not optimal. It became obvious that the use of actively deflecting tips would greatly expand the capabilities of the flexible ureteroscope. Bagley and Rittenberg determined the optimal tip deflection necessary to visualize completely the entire intrarenal architecture. Using radiographs of 30 patients, they determined that the average angle between the major axis and the lower pole infundibulum was 140 degrees and a maximum of 175 degrees. As a result, they recommended the development of a flexible ureteroscope with a 175-degree deflecting tip [28]. Downsizing the ureteroscope by upsizing working channels In the latter half of the 1980s, several flexible deflectable ureteroscopes became available in different sizes ranging from 8.1 to 10.8F (2.7–3.6 mm) and with different options, including some
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
9
with small working channels [28]. The 10.8F instrument, initially designed as a pediatric bronchoscope and lengthened for use in ureteroscopy, offered a 1.2-mm channel that could accept up to a 3.5F instrument (brush, snare, electrode, or electrohydraulic lithotriptor probe) or a 0.038 guidewire [29]. These ureteroscopes could be passed up the ureter over a wire and used to visualize the pelvis without a sheath. Several groups reported their initial success using these new ureteroscopes [29,30,31]. Despite these advancements in ureteroscope technology, it remained difficult to access the lower pole caliceal system. Grasso et al [28] reported the use of a new instrument with a tapered design and the ability for passive and active deflection. The ureteroscope had an 8.2F sheath with a 3-cm long distal tip with a 7.5F diameter. It supported a two-way active deflection of 170 and 120 degrees with the added relief of secondary passive deflection. These improvements enhanced access to the lower pole caliceal systems. A working channel of 3.6 mm was maintained through its design that allowed the use of a multitude of instruments, including guidewires, stone retrieval devices, electrodes and laser fibers, and electrohydraulic lithotriptor probes. The small tip also allowed access to the ureter in some patients without dilatation, negating the need for routine ureteral stent placement after ureteroscopy.
ranged from 4.5 to 11.9F. At the same time, working channels expanded to range from 1.8 to 5.5F. Equally useful, a new ureteroscope was developed with an offset lens that permitted a straight working channel for rigid lithotripsy [33].
Semirigid ureteroscope
Intraluminal lithotripsy
The metamorphosis of the rigid ureteroscope continued with the introduction of a smaller caliber and semirigid design fitted with two working channels. The ureteroscope was tapered to allow easy insertion into the distal ureter without dilation but still provide stability on its wider proximal end. The distal end had a diameter of 7.2F, a midshaft of 10.2F, and a proximal end of 11.9F. The semirigid ureteroscope used flexible optical fibers that allowed unimpaired vision when flexed up to 2 in [32]. Although it was developed to facilitate laser lithotripsy, the semirigid ureteroscope quickly replaced the rigid ureteroscope owing to its increased versatility. In the 1990s, manufacturers capitalized on new fiber-packing techniques to increase pixel density substantially and improve image transmission. Fiberoptic light and image transmission conserved space and allowed further improvements. The tips of the ureteroscope continued to contract and
Historically, upper urinary tract lithotripsy has been performed using ultrasonic, electrohydraulic, electromechanical, pneumatic, and laser energy sources. The choice of energy is partially dependent on the type of ureteroscope (because ultrasonic and pneumatic devices are rigid). Ultrasonic lithotripsy was the first modality used for intracorporeal lithotripsy. In 1952, Mulvaney [36] attempted to destroy stones using a 0.8-kHz device. In 1955, Coates [37] achieved partial stone fragmentation using a 15-kHz device. Zheng and Denstedt [38] described four methods of generating ultrasound waves: mechanically, thermally, electrostatically, and piezoelectrically. All current devices use the piezoelectric method. The use of solid-wire and hollow-bore ultrasonotrodes has been reported in the older ureteroscopy literature [39]. Electrohydraulic lithotripsy was first attempted by Yutkin of Kiev in 1955 [40]. Probes were upgraded and downsized
Pediatric ureteroscopy Improvements in the smaller rigid and flexible ureteroscopes with working channels that could accommodate stone-manipulating instruments led to their eventual use in the pediatric population. In 1988, Ritchey et al [34] used a pulsed dye laser through an 8.5F rigid ureteroscope to fragment a distal ureteral calculi. The ureteroscope was passed through the bladder and up to the ureter without dilation. The pieces were removed with a 3.5F basket. Recently, Schuster et al [35] reported their 7-year experience treating ureteral calculi in 25 children. Ninety-two percent of the children were rendered stone free after one procedure and 100% after two procedures. There were no intraoperative complications, two postoperative complications of pyelonephritis, and one stent migration. Most patients were discharged home in less than 24 hours. This study demonstrated the safety and effectiveness of newer ureteroscopes in the endoscopic management of calculi in the pediatric population.
10
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
(9F), and single pulse techniques were tried with early ureteroscopes. These early techniques were often blind, but success rates were as high as 90% [41]. Further improvements in probe design and generator design resulted in even smaller electrohydraulic lithotripsy units. Clinically, electrohydraulic lithotripsy with 1.9F probes has resulted in successful fragmentation in 98% of patients [42]. Nevertheless, electrohydraulic lithotripsy has potential for adverse tissue effects and a smaller window for safety. The use of direct impact devices, the so-called ‘‘ballistic’’ or pneumatic devices, reduced the unintentional risk of injury to the ureter. Languetin et al [43] first described the Swiss Lithoclast in 1990 developed from the principles described by Heurteloup for breaking bladder stones in 1832. Because these devices use a forceful impact to destroy a targeted calculus and have no thermal or cavitation effects, the risk of injury to the ureteral wall is minimal. There are now five manufacturers of these devices and probes, which range in size from 1/6 to 5.9 F in diameter. Success rates range from 70% to 100% depending on the series, size, and location of the targeted stone. The fundamental flaw of this
system is the relatively inflexible probe that is not suited for flexible ureteroscopy. This drawback led, in turn, to the natural progression to laser lithotripsy. Mulvaney and Beck [44] attempted to destroy a bladder calculus with a ruby laser in 1968. The pulsed dye laser (coumarin green) was initially used by Watson in 1984 [45]. Next, continuous wave neodymium: yttrium-aluminum-garnet (Nd:YAG) and Q-switched Nd:YAG lasers were evaluated [46]. Alexandrite lasers operating at 755 nm were thought by some researchers to be ideal for fragmenting stones with little risk for ureteral injury [47]. All of these modalities failed owing to one or more reasons but most notably because of the emergence of the holmium:YAG (Ho:YAG) laser. Early in 1992, Johnson and colleagues [48] noted that the midinfrared laser irradiation of the Ho:YAG laser had urologic potential. The following year, this same group reported the successful use of this laser wavelength for ureteroscopic lithotripsy [49]. Series began to accrue as soon as it was realized that many of the drawbacks associated with the other laser systems were no longer applicable, because the
Fig. 4. Landmarks in the History and Development of the Ureteroscope.
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
11
Box 1. Milestones in ureteroscopy and ureteroscopic instruments 1841, Colladon: The concept of fiberoptics is born; light is found to travel in a medium along a curve. 1841, Babinet: Light is guided along bent glass rods. 1854, Tyndall: A gallant display of Colladon’s light guiding is performed, often incorrectly credited with its discovery. 1912, Young: First ureteroscopy is performed on a child with posterior urethral valves. 1927, Baird: Patent is applied for parallel glass rods or hollow tubes that carry an image. 1930, Hansell: Patent is applied for image bundling. 1957, Curtiss: Physics student develops glass cladding. 1957, Hirschowitz: Hirschowitz uses fiberoptics and glass cladding to develop and test the first flexible endoscope (gastroscope) on himself and diagnoses an ulcer in one of his patients. 1959, Buehler: Nitinol alloy is discovered. 1960, Marshall: First flexible ureteroscopy is performed. 1960, Hopkins: An optical system is developed based on cylindrical rodlike lenses to replace the hollow tube through air image system. 1962, McGovern: First transurethral flexible ureteroscopy is performed. 1966, Bush: Argon lasers are used on renal calculi in a cow’s kidney. 1968, Takagi: First photograph of the upper urinary tract is recorded. 1970, Takayasu: First video of the upper urinary tract is recorded. 1977, Goodman: First purposeful use of the rigid ureteroscope is performed. 1978, Lyon: Ureteral dilation and rigid ureteroscopy are performed in women. 1979: Richard Wolf Medical Instruments develops a longer instrument intended for ureteroscopy. 1979, Lyon: Ureteral dilation and rigid ureteroscopy are performed in men. 1980: Karl Storz Endoscopy develops a 50-cm rigid ureteroscope to reach the pelvis. 1981, Das: Ureteral stone basketing is performed under direct vision. 1983, Huffman: Ureteroscopic ultrasonic lithotripsy is performed. 1983, Bagley: A flexible tip ureteroscope is introduced. 1983, Huffman: Baloon dilation of the ureter is performed. 1985, Green: Transureteral electrohydraulic lithotripsy is described. 1988, Dretler: The semirigid ureteroscope is described. 1988, Ritchey: Pulsed dye laser lithotripsy is performed in a pediatric patient. 1994, Grasso: The two-way deflecting ureteroscope with active and passive deflection is used. 1994, Grasso: Tests are performed of a pneumatic lithotripsy transmitted along a nitinol probe in semirigid and flexible ureteroscopes. 1995, Erhard: Ho:YAG laser lithotripsy is first reported. 1997, Murthy: Experience with ureteroscopic pneumatic lithotripsy is reported. 1998, Honey: Experience with new nitinol ureteroscopic baskets is reported.
Ho:YAG laser had durable small fibers, applicability to all stone types, and a wide power selectivity. The Ho:YAG laser also permitted focused coagulation or fulguration through the ureteroscope to control bleeding, to treat superficial tumors, or to incise narrowed areas, such as in ureteral pelvic obstruction or infundibular stenosis.
Technological advancements in ureteroscopic instruments have paralleled advancements in the ureteroscope, revolutionizing the endoscopic treatment of renal calculi and upper tract pathology. Most importantly, these advancements have greatly improved patient safety and postoperative comfort, reducing the need for ureteral dilation and stent placement.
12
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
Durability of the flexible ureteroscope With the expanded applications and capabilities of the flexible ureteroscope, durability of the smaller instruments became an increasing concern. In 1998, White and Moran [50] described that increased use of these small flexible instruments was directly related to the number and types of mechanical failure. By 2000, Afane et al [51] confirmed that flexible ureteroscopes smaller than 9F had an average of 6 to 15 uses before repair was required. More recently in 2002, Pietrow et al [52] assessed methods to improve the longevity of the 7.5F flexible ureteroscope. This group believed that the incorporation of new ureteroscopic accessories (access sheath, nitinol baskets, and a 200 lm holmium laser fiber) would maximize ureteroscope durability, alleviating the most common problem of loss of tip deflection capabilities. Having developed a small ureteroscope with capable working channels and superior vision, manufacturers hope to improve on the durability of these ureteroscopes in the future.
Future Future improvements in ureteroscopy will rely on continued application of new technology. The use of digital imaging and computer-integrated systems should further refine the approach to and documentation of upper tract abnormalities. Smaller instruments with expanded dexterity will allow greater access to difficult to view areas. Wireless image transmission or light sources imbedded within the endoscope could greatly reduce restriction brought about by light and video cords. In the quest to make a smaller more versatile ureteroscope, manufacturers must improve the durability of the ureteroscope by using new materials and designs.
Summary Technology and refinements in urology have prospered with the bonding of engineers and surgeons. The introduction of fiberoptics and the development of the ureteroscope opened the doors to the field of ureteroscopy. Advances in rigid and flexible ureteroscopy with irrigating and working channels have expanded the capability of the urologist to diagnose and treat most abnormalities of the upper tracts in adult and pediatric populations. Instrument development has easily
paralleled the growth and development of the ureteroscope and has improved success, patient safety, and comfort with the incorporation of access sheaths, nitinol materials, and Ho:YAG laser technology. Owing to their minimal morbidity and high success rate, ureteroscopic evaluation and therapeutic interventions in the upper tract represent the gold standard of management. Albert Einstein said, ‘‘There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.’’ Contemporary ureteroscopy is a historical miracle that has opened a vista of endless limits in upper tract endoscopy (Fig. 4, Box 1).
References [1] Young HH, McKay RW. Congenital valvular obstruction of the prostatic urethra. Surg Gynecol Obstet 1929;48:509. [2] Curtiss LE, Hirschowitz BI, Peters CW. J Optic Soc Am 1957;47:117. [3] Colladon D. On the reflections of a ray of light inside a parabolic liquid stream. Comptes Rendus 1842;15,800. [4] Hecht J. City of lights: the story of fiber optics. New York: Oxford University Press; 1999. p. 13–27. [5] Barlow DE. Fiberoptic instrument technology. In: Small animal endoscopy. St. Louis: C.V. Mosby; 1990. p. 1. [6] Baird JL. British Patent Specification No. 20, 969/ 27, 1927. [7] Hansell CW. US Patent No. 1,751,584, 1930. [8] Hecht J. City of lights: the story of fiber optics. New York: Oxford University Press; 1999. p. 60–75. [9] Hirschowitz BI, Curtiss LE, Peters CW, Pollard HM. Gastroenterology 1958;35:50. [10] Marshall VF. Fiber optics in urology. J Urol 1964; 91:110. [11] Takagi T, Go T, Takayasu H, Aso Y. A smallcaliber fiberscope for visualization of urinary tract, biliary tract, and spinal canal. Surgery 1968;64: 1033. [12] Bush IM, Whitmore WF, Lieberman PH, Paananen R, Whitehouse D. Experimental surgical applications of the laser. Presented at the Association for the Advancement of Medical Instrumentation. Boston, 1966. [13] Takayasu H, Aso Y, Takagi T, Go T. Clinical application of fiber-optic pyeloureteroscope. Urol Int 1971;26:97. [14] Goodman TM. Ureteroscopy with pediatric cystoscope in adults. Urology 1977;9(4):394. [15] Lyon ES, Kyker JS, Shoenberg HW. Transurethral ureteroscopy in women: a ready addition to
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
[16]
[17] [18] [19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27] [28]
[29]
[30]
[31]
[32] [33]
the urological armamentarium. J Urol 1978; 119:35. Lyon ES, Banno JJ, Shoenberg HW. Transurethral ureteroscopy in men using juvenile cystoscopy equipment. J Urol 1979;122:152. Das S. Transurethral ureteroscopy and stone manipulation under direct vision. J Urol 1981;125:112. Hopkins HH. US Patent No. 3,257,902, 1966. Huffman JL, Bagley DH, Lyon ES. Treatment of distal ureteral calculi using rigid ureteroscope. Urology 1982;20(6):574. Castro EP, Gorro AP, Delatte LC. Transurethral ureteroscopy: a current urological procedure. Arch Esp Urol 1980;33:445. Huffman JL, Bagley DH, Lyon ES. Extending cystoscopic techniques into the ureter and renal pelvis. JAMA 1983;250(15):2002. Huffman JL, Bagley DH, Lyon ES, Morse MJ, Herr HW, Whitmore WF Jr. Endoscopic diagnosis and treatment of upper-tract urothelial tumors. Cancer 1985;55:1422. Huffman JL, Bagley DH, Schoenberg HW, Lyon ES. Transurethral removal of large ureteral and renal pelvic calculi using ureteroscopic ultrasonic lithotripsy. J Urol 1983;130:31. Green DF, Lytton B. Early experience with direct vision electrohydraulic lithotripsy of ureteral calculi. J Urol 1985;133:767. Lingeman JE, Sonda LP, Kahnoski RJ, Coury TA, Newman DM, Mosbaugh PG, et al. Ureteral stone management: emerging concepts. J Urol 1986;135: 1172. Bagley DH, Huffman JL, Lyon ES. Combine rigid and flexible ureteropyeloscopy. J Urol 1983;130: 243. Takagi T, Go T, Takayasu H, Aso Y. Fiberoptic pyeloureteroscope. Surgery 1971;70:661. Grasso M, Bagley D. A 7.5/8.2F actively deflectable, flexible ureteroscope: a new device for both diagnostic and therapeutic upper urinary tract endoscopy. Urology 1994;43(4):435. Bagley DH, Huffman JL, Lyon ES. Flexible ureteropyeloscopy: diagnosis and treatment in the upper urinary tract. J Urol 1987;138:280. Streem SB, Pontes JE, Novick AC, Montie JE. Ureteropyeloscopy in the evaluation of upper tract filling defects. J Urol 1986;136:383. Kavoussi L, Clayman RV, Basler J. Flexible, actively deflectable fiberoptic ureteronephroscopy. J Urol 1989;142:949. Dretler SP, Cho G. Semirigid ureteroscopy: a new genre. J Urol 1989;141:1314. Ferraro RF, Abraham VE, Cohen TD, Preminger GM. A new generation of semirigid fiberoptic ureteroscopes. J Endourol 1999;13:35.
13
[34] Ritchey M, Patterson DE, Kelalis PP, Segura JW. A case of pediatric ureteroscopic lasertripsy. J Urol 1988;139:1272. [35] Schuster TG, Russel KY, Bloom DA, Koo HP, Faerber GJ. Ureteroscopy for the treatment of urolithiasis in children. J Urol 2002;167:1813. [36] Mulvaney WD. Attempted disintegration of calculi by ultrasonic vibrations. J Urol 1953;70:704. [37] Coates EC. The application of ultrasonic energy to urinary and biliary calculi. J Urol 1956;75:865. [38] Zheng W, Denstedt JD. Intracorporeal lithotripsy: update on technology. Urol Clin North Am 1970; 27:47. [39] Fuchs GJ. Ultrasonic lithotripsy in the ureter. Urol Clin North Am 1988;15:347–59. [40] Grocela JA, Dretler SP. Intracorporeal lithotripsy: instrumentation and development. Urol Clin North Am 1997;24:13. [41] Raney AM. Electrohydraulic ureterolithotripsy. Urology 1978;7:284. [42] Denstedt JD, Clayman RV. Electrohydraulic lithotripsy of renal and ureteral calculi. J Urol 1990; 143:13. [43] Languetin JMP, Jichlinski, et al. The Swiss Lithoclast. J Urol 1900;143:179A. [44] Mulvaney WP, Beck CW. The laser beam in urology. J Urol 1968;99:112–5. [45] Watson GM, Dretler SP, Parrish JA. The pulsed dye laser for fragmenting urinary calculi. J Urol 1997;138:195–8. [46] Hofmann R, Hartung R, Schmidt-Kloiber H, Reichel E. First clinical experience with a Qswitched neodymium:YAG laser for urinary calculi. J Urol 1989;141:275–9. [47] Weber HM, Miller K, Ruschoff J, Gschwend J, Hautmann RE. Alexandrite laser lithotripter in experimental and first clinical application. J Endourol 1991;5:51–5. [48] Johnson DE, Cromeens DM, Price RE. Use of the holmium:YAG laser in urology. Lasers Surg Med 1992;12:353–63. [49] Sayer J, Johnson DE, Price RE, Cromeens DM. Ureteral lithotripsy with the holmium:YAG laser. J Clin Laser Med Surg 1993;11:61–5. [50] White MD, Moran ME. Fatigability of the latest generation ureteropyeloscopes: Richard Wolf vs. Karl Storz [abstract]. J Endourol 2000;15:D33. [51] Afane JS, Olweny EO, Bercowsky E, Sundaram CP, Dunn MD, Shalhav AL, et al. Flexible ureteroscopes: a single center evaluation of the durability and function of the new endoscopes smaller than 9 Fr. J Urol 2000;164(4):1164. [52] Pietrow PK, Auge BK, Delvecchio FC, Silverstein AD, et al. Techniques to maximize flexible ureteroscope longevity. Urology 2002;60(5):784.
The evolution and progress of ureteroscopy William K. Johnston III, MDa, Roger K. Low, MDb, Sakti Das, MDb,* a
Minimally Invasive Urology, University of Michigan, 1500 E. Medical Center Drive, Taubman Center 2916, Ann Arbor, MI 48109-0330, USA b Department of Urology, University of California, Davis, 4860 Y Street, Suite 3500, Sacramento, CA 95817, USA
The evolution of ureteroscopy is a beguiling saga of human ingenuity and relentless pursuit for improvement. Historically, it started serendipitously in 1912 when Hugh Hampton Young inadvertently introduced a 12F pediatric cystoscope into a massively dilated right ureter of a child who had posterior urethral valves and found himself gazing at the renal pelvis. While in the renal pelvis, Young attempted unsuccessfully to witness ‘‘jets of urine’’ from the papillae [1]. His discovery humbly remained torpid within a thorough review article devoted to congenital valvular obstruction of the prostatic urethra that was not published until 1929 [1]. Fiberoptics Documented advances in ureteroscopy would lay dormant over the next 30 years until fiberoptic technology was integrated into medical instruments and allowed image transmission as first developed by Curtiss et al [2]. The technology that allowed fiberoptics was developed nearly 100 years earlier. In 1841, Daniel Colladon at the University of Geneva made the first step toward the development of fiberoptics by disproving the belief that light only traveled in a straight line. He demonstrated that light could be trapped within a transparent medium and carried by internal reflection. Colladon publicly demonstrated ‘‘light guiding’’ * Corresponding author. 1890 Via Ferrari, Lafayette, CA 94549. E-mail address: [email protected] (S. Das).
during his lectures [3]. Jacques Babinet, a French specialist in optics, extended Colladon’s principles by demonstrating guiding light along bent glass rods [4]. The first suggestion of the technology behind contemporary fiberoptics originated in the 1840s with Colladon and Babinet’s work. Yet, at that time, they viewed light guiding as nothing more than a ‘‘parlor trick’’ [4]. Colladon’s work has been shadowed historically by a more well-known and gallant demonstration of light guiding by Professor John Tyndall. In 1854, Tyndall demonstrated that light could be trapped within water and carried by internal reflection, much as Colladon had 13 years prior. Tyndall performed light guiding to the amazement of his assembled peers. His experiment boldly involved cutting a hole in the roof of his building for the installation of an open-top container filled with water. The room below was fitted with a washtub. In complete darkness waited an august audience composed of members of the Royal Institution of Great Britain. He unplugged a hole in the side of the container and allowed the water to curve below into the basin, carrying with it the sunlight trapped with the stream (Fig. 1) [5]. Two patents expanding on Colladon’s work on the internal reflection phenomenon were obtained in 1927 and 1930 by Baird and Hansell, respectively. In these patents, the first applications were provided for fiber bundles providing image transmission through internal reflection. Baird described an array of parallel glass rods or hollow tubes to carry an image in a mechanical television. Hansell introduced the principles of image bundling (Fig. 2) [6,7].
0094-0143/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/S0094-0143(03)00100-9
6
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
veloping a new type of fiber covered by glass (glass clad) that dramatically protected the reflective surface from contamination and that greatly reduced image mixing between adjacent fibers (Fig. 3). Curtiss combined a large number of fibers in a group to form a coherent bundle. The fibers were fused together at their ends to preserve orientation but were allowed to move individually along the length within the loose outer sheath. Hirschowitz tested the first gastroscope in 1957 on himself and the following day diagnosed a stomach ulcer under direct view in one of his patients [8]. Curtiss and Hirschowitz introduced the first fiberscope that stimulated interest in the development of new endoscopic instruments for other endoscopic applications [2,9]. Fig. 1. Although Colladon in 1841 initially described how light can be trapped within a medium (water) and can travel by internal reflection along a curved path, Tyndall performed a gallant demonstration of light guiding to the amazement of the Royal Institution of Great Britain in 1854.
The fiber bundles of Baird and Hansell were put to clinical use in the early 1950s. Basil Hirschowitz, a gastroenterologist at the University of Michigan, imagined using fiberoptics to develop a flexible gastroscope. He recruited a sophomore physics student, Lawrence Curtiss, to join him in his quest [8]. By 1957, they had combined their respective talents and described the first clinical experience with a new instrument using fiberoptic technology that allowed flexible gastroscopy. Curtiss made a landmark contribution by de-
Fig. 2. Fiberoptics integrated into fiber bundles allow for image transmission while maintaining image position.
First flexible endoscope (ureteroscope) By 1960, physicians in other specialties began to experiment with the 9F flexible fiberscope. In 1960, Marshall reported the first use of the new 9F flexible fiberscope to inspect the renal pelvis during an open operation and completed the first flexible ureteroscopy. A ureterotomy was made 5 cm below the renal pelvis to inspect for renal calculi [10]. Subsequently, in 1962, Marshall’s associates (McGovern and Walzak) completed the first transurethral flexible ureteroscopy with the 9F fiberscope. They passed the ureteroscope through a 26F McCarthy endoscope 10 cm up the left ureter to visualize a ureteral stone [10]. In 1968, Takagi et al [11] described the use of a 70cm, 8F fiberoptic endoscope to visualize the renal pelvis and papillae in cadavers and subsequently in patients during surgery. They were able to share their findings through photographs of the renal papillae with their newly developed endoscope [11]. Takagi’s group explored applications of the
Fig. 3. Using fiberoptics, light travels by internal reflection. Light constantly reflects from the cladding with a lower index of reflection than the core with a high index of reflection. The cladding does not absorb any light, allowing propagation of the light or image.
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
endoscope not only in the urinary tract but also in the biliary tract and spinal canal. Within the biliary tract, they noted difficulty manipulating the tip. Accordingly, they passed the endoscope through a 12F venous catheter to provide rigidity and transmitted torque. This technique allowed them to persuade the tip in the desired direction, establishing the importance of developing a deflectable tip endoscope [11]. Upper urinary tract abnormalities could now be visualized with the new flexible endoscope; treatment would be the next logical step pursued by researchers. In 1966, Bush et al [12] entertained the idea of using argon lasers to improve illumination and possibly treat upper tract tumors and bleeding through an ureteroscope. They demonstrated the effects of focused argon laser light on renal calculi placed in the pelvis of a cow’s kidney. Further evidence of the effectiveness of ureteroscopy was displayed by Takayasu et al [13] in the early 1970s when, for the first time, movies of the upper tract were completed. Takayasu and coworkers predicted that the fiberscope, with further refinement of accessories, would ‘‘contribute tremendously to the progress of medicine and happiness of mankind’’ [13]. Rigid ureteroscopy Surprisingly, the development and first purposeful use of rigid ureteroscopy in 1977 by Goodman [14] lagged initial reports of flexible ureteroscopy by nearly 10 years. Goodman reported on three cases in which an 11F pediatric cystoscope was used to manage ureteral problems. In one case, the cystoscope was used to inspect the ureter to the ureteropelvic junction; in a second patient, a biopsy specimen of a ureteral mucosal irregularity was obtained; in a third patient, fulguration of a ureteral tumor was performed. At the time, researchers were concerned about the morbidity of ureteroscopy and recommended using ‘‘greatest gentleness’’ to avoid ureteral perforation or damage [14]. In 1978, Lyon et al [15] described a new technique of ureteral dilation using Jewitt sounds passed adjacent to a cystoscope, transurethrally. This technique allowed distal ureteroscopy in women for management of transitional cell carcinoma while minimizing the risk of ureteral trauma or perforation. The following year, Lyon’s group described rigid ureteroscopy in men. They used a 13F juvenile cystoscope of standard adult length. The procedure involved passing specially designed flexible
7
ureteral dilators through a 25.5F cystoscope. Next, a 13F juvenile cystoscope of standard adult length was introduced into the ureter. To perform coagulation or basketing under direct vision, they proposed using a 14.5 juvenile resectoscope and a juvenile cystoscopic sheath, respectively. The length of the instrument limited exploration beyond 4 cm proximally [16]. Nonetheless, their work set the stage for expanding ureteroscopic applications. Stone manipulation Before 1981, urologists treated ureteral calculi with open ureterolithotomy or by using blind tactile manipulation. Both techniques were challenging owing to the variable success of blind endoscopic manipulation and the morbidity associated with the open procedure. Furthermore, distal ureteral calculi were particularly difficult to reach through an open approach. Accordingly, in 1981, the first transurethral ureteroscopy with stone basketing under direct vision was described by Das [17]. These advancements demonstrated the usefulness and ease of rigid ureteroscopy in men and women, opening the doors for further refinement and advancement. Initially, safety concerns continued to hinder the growth and widespread use of ureteroscopy. The greatest uneasiness centered on the size of the instruments. This concern was alleviated by the development of a smaller diameter rigid ureteroscope based on work completed by Hopkins in 1960. Hopkins introduced an optical system with cylindrical rodlike lenses [18]. The main purpose was to convey optical images for endoscopes along glass rods. Previous endoscopes relied on a hollow tube with serial aligned lenses to transmit an image along the tube through air. Such a system depended on perfectly aligned lenses to avoid loss of the image. In Hopkins’ system, images traveled along glass rods with a higher refractive index and a more durable construction than previous systems. This design allowed the development of smaller outer diameter endoscopes and expanded working and irrigating channels. Up to this point in time, ureteroscopy in women had been well described [15], but progress and routine use in men had been delayed by limitations of the instruments. Richard Wolf Medical Instruments (Vernon Hills, IL) developed the first endoscope specifically intended for ureteroscopy. They combined the diametric size of a 13F pediatric cystoscope with the length of a standard adult
8
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
cystoscope (23 cm). Lyon and associates [16] reported the first use of the new longer ureteroscope in men in 1979. Huffman et al [19] described their initial experience using the new ureteroscope in the treatment of 16 distal ureteral calculi. They successfully removed the stones in 69% of the cases using a similar technique described by Lyon and previously used by Das to remove a distal ureteral calculus [16,17]. Despite the success of the newer smaller diameter long ureteroscope, its use was still limited to the distal ureter. Karl Storz Endoscopy (Tuttlingen, Germany), led by pioneers Perez-Castro and MartinezPiniero, entered the arena of endoscopy with the introduction of a longer ureteroscope (50 cm) that could reach the renal pelvis [20]. This new design allowed diagnostic ureteroscopy, biopsy, direct viewing of stone manipulation, and coagulation. Equally important, this work prompted further development and refinement of the long rigid ureteroscope with different lengths (25–54 cm), interchangeable lenses (0–70 degrees), and different sizes (9–16F). The new ‘‘ureteropyeloscopes’’ supported working channels measuring 5F and accommodated flexible instruments such as wires, stone baskets, biopsy forceps, and brushes. In 1983, Huffman et al [21] reported their initial experience using the new ureteroscopes throughout the upper tract to diagnose, treat, and followup upper tract tumors and to extract upper tract calculi. The findings confirmed the safety and success of the longer rigid ureteroscope. This group reported on 31 patients with upper tract urothelial tumors diagnosed and treated through a transurethral endoscopic approach [22]. In addition, Huffman et al [23] reported their initial experience with ureteroscopic ultrasonic lithotripsy. The stone was secured in place with a basket advanced through the working channel. The telescope was removed, which allowed passage of the ultrasonic lithotriptor for fragmentation. Fluoroscopic imaging confirmed contact between the stone and lithotriptor [23]. The success of this technique was later confirmed by others [24] who performed stone manipulation of the proximal ureter and pelvis [25]. The rigid ureteropyeloscope had limitations, specifically in patients who had a torturous or narrowed ureter. Although the rigid ureteroscope provided upper pole visualization, it was difficult to enter the lower pole in many patients. It became apparent that rigid and flexible ureteroscopy needed to be combined to expand access. The difficulty in reaching intrarenal territory for the treatment of lesions and calculi
renewed interest in further developing the flexible ureteroscope. Flexible tip ureteroscopy In 1983, Bagley et al [26] described use of the new 55- and 80-cm flexible tip pyeloscope. The tip deflected 160 degrees in one direction and 90 degrees in the opposite direction. The flexible ureteroscope was small enough to fit through the sheath of the rigid telescope after removing the telescope. Passing the flexible ureteroscope through the rigid sheath alleviated two problems previously encountered with flexible ureteroscopy. One of these problems—difficulty in maneuvering the flexible ureteroscope in the renal pelvis—had been overcome in the past with placement of a polytetrafluoroethylene guide sheath to support the scope within the ureter [27]. The other problem—irrigation—had been improved marginally by promoting diuresis or by flushing through an outer sheath or ureteral catheter. With use of the rigid ureteroscope with two working channels, the flexible ureteroscope could wind through narrowed areas and provide panoramic visualization. Irrigation through the other channel distended the ureter and maintained visualization, alleviating both problems. Earlier flexible ureteroscopes relied on passive deflection as they were passed through the ureter. With the introduction of the rigid ureteroscope, the flexible ureteroscope could be passed through the rigid ureteroscope or, eventually, over a guidewire; however, this technique was not optimal. It became obvious that the use of actively deflecting tips would greatly expand the capabilities of the flexible ureteroscope. Bagley and Rittenberg determined the optimal tip deflection necessary to visualize completely the entire intrarenal architecture. Using radiographs of 30 patients, they determined that the average angle between the major axis and the lower pole infundibulum was 140 degrees and a maximum of 175 degrees. As a result, they recommended the development of a flexible ureteroscope with a 175-degree deflecting tip [28]. Downsizing the ureteroscope by upsizing working channels In the latter half of the 1980s, several flexible deflectable ureteroscopes became available in different sizes ranging from 8.1 to 10.8F (2.7–3.6 mm) and with different options, including some
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
9
with small working channels [28]. The 10.8F instrument, initially designed as a pediatric bronchoscope and lengthened for use in ureteroscopy, offered a 1.2-mm channel that could accept up to a 3.5F instrument (brush, snare, electrode, or electrohydraulic lithotriptor probe) or a 0.038 guidewire [29]. These ureteroscopes could be passed up the ureter over a wire and used to visualize the pelvis without a sheath. Several groups reported their initial success using these new ureteroscopes [29,30,31]. Despite these advancements in ureteroscope technology, it remained difficult to access the lower pole caliceal system. Grasso et al [28] reported the use of a new instrument with a tapered design and the ability for passive and active deflection. The ureteroscope had an 8.2F sheath with a 3-cm long distal tip with a 7.5F diameter. It supported a two-way active deflection of 170 and 120 degrees with the added relief of secondary passive deflection. These improvements enhanced access to the lower pole caliceal systems. A working channel of 3.6 mm was maintained through its design that allowed the use of a multitude of instruments, including guidewires, stone retrieval devices, electrodes and laser fibers, and electrohydraulic lithotriptor probes. The small tip also allowed access to the ureter in some patients without dilatation, negating the need for routine ureteral stent placement after ureteroscopy.
ranged from 4.5 to 11.9F. At the same time, working channels expanded to range from 1.8 to 5.5F. Equally useful, a new ureteroscope was developed with an offset lens that permitted a straight working channel for rigid lithotripsy [33].
Semirigid ureteroscope
Intraluminal lithotripsy
The metamorphosis of the rigid ureteroscope continued with the introduction of a smaller caliber and semirigid design fitted with two working channels. The ureteroscope was tapered to allow easy insertion into the distal ureter without dilation but still provide stability on its wider proximal end. The distal end had a diameter of 7.2F, a midshaft of 10.2F, and a proximal end of 11.9F. The semirigid ureteroscope used flexible optical fibers that allowed unimpaired vision when flexed up to 2 in [32]. Although it was developed to facilitate laser lithotripsy, the semirigid ureteroscope quickly replaced the rigid ureteroscope owing to its increased versatility. In the 1990s, manufacturers capitalized on new fiber-packing techniques to increase pixel density substantially and improve image transmission. Fiberoptic light and image transmission conserved space and allowed further improvements. The tips of the ureteroscope continued to contract and
Historically, upper urinary tract lithotripsy has been performed using ultrasonic, electrohydraulic, electromechanical, pneumatic, and laser energy sources. The choice of energy is partially dependent on the type of ureteroscope (because ultrasonic and pneumatic devices are rigid). Ultrasonic lithotripsy was the first modality used for intracorporeal lithotripsy. In 1952, Mulvaney [36] attempted to destroy stones using a 0.8-kHz device. In 1955, Coates [37] achieved partial stone fragmentation using a 15-kHz device. Zheng and Denstedt [38] described four methods of generating ultrasound waves: mechanically, thermally, electrostatically, and piezoelectrically. All current devices use the piezoelectric method. The use of solid-wire and hollow-bore ultrasonotrodes has been reported in the older ureteroscopy literature [39]. Electrohydraulic lithotripsy was first attempted by Yutkin of Kiev in 1955 [40]. Probes were upgraded and downsized
Pediatric ureteroscopy Improvements in the smaller rigid and flexible ureteroscopes with working channels that could accommodate stone-manipulating instruments led to their eventual use in the pediatric population. In 1988, Ritchey et al [34] used a pulsed dye laser through an 8.5F rigid ureteroscope to fragment a distal ureteral calculi. The ureteroscope was passed through the bladder and up to the ureter without dilation. The pieces were removed with a 3.5F basket. Recently, Schuster et al [35] reported their 7-year experience treating ureteral calculi in 25 children. Ninety-two percent of the children were rendered stone free after one procedure and 100% after two procedures. There were no intraoperative complications, two postoperative complications of pyelonephritis, and one stent migration. Most patients were discharged home in less than 24 hours. This study demonstrated the safety and effectiveness of newer ureteroscopes in the endoscopic management of calculi in the pediatric population.
10
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
(9F), and single pulse techniques were tried with early ureteroscopes. These early techniques were often blind, but success rates were as high as 90% [41]. Further improvements in probe design and generator design resulted in even smaller electrohydraulic lithotripsy units. Clinically, electrohydraulic lithotripsy with 1.9F probes has resulted in successful fragmentation in 98% of patients [42]. Nevertheless, electrohydraulic lithotripsy has potential for adverse tissue effects and a smaller window for safety. The use of direct impact devices, the so-called ‘‘ballistic’’ or pneumatic devices, reduced the unintentional risk of injury to the ureter. Languetin et al [43] first described the Swiss Lithoclast in 1990 developed from the principles described by Heurteloup for breaking bladder stones in 1832. Because these devices use a forceful impact to destroy a targeted calculus and have no thermal or cavitation effects, the risk of injury to the ureteral wall is minimal. There are now five manufacturers of these devices and probes, which range in size from 1/6 to 5.9 F in diameter. Success rates range from 70% to 100% depending on the series, size, and location of the targeted stone. The fundamental flaw of this
system is the relatively inflexible probe that is not suited for flexible ureteroscopy. This drawback led, in turn, to the natural progression to laser lithotripsy. Mulvaney and Beck [44] attempted to destroy a bladder calculus with a ruby laser in 1968. The pulsed dye laser (coumarin green) was initially used by Watson in 1984 [45]. Next, continuous wave neodymium: yttrium-aluminum-garnet (Nd:YAG) and Q-switched Nd:YAG lasers were evaluated [46]. Alexandrite lasers operating at 755 nm were thought by some researchers to be ideal for fragmenting stones with little risk for ureteral injury [47]. All of these modalities failed owing to one or more reasons but most notably because of the emergence of the holmium:YAG (Ho:YAG) laser. Early in 1992, Johnson and colleagues [48] noted that the midinfrared laser irradiation of the Ho:YAG laser had urologic potential. The following year, this same group reported the successful use of this laser wavelength for ureteroscopic lithotripsy [49]. Series began to accrue as soon as it was realized that many of the drawbacks associated with the other laser systems were no longer applicable, because the
Fig. 4. Landmarks in the History and Development of the Ureteroscope.
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
11
Box 1. Milestones in ureteroscopy and ureteroscopic instruments 1841, Colladon: The concept of fiberoptics is born; light is found to travel in a medium along a curve. 1841, Babinet: Light is guided along bent glass rods. 1854, Tyndall: A gallant display of Colladon’s light guiding is performed, often incorrectly credited with its discovery. 1912, Young: First ureteroscopy is performed on a child with posterior urethral valves. 1927, Baird: Patent is applied for parallel glass rods or hollow tubes that carry an image. 1930, Hansell: Patent is applied for image bundling. 1957, Curtiss: Physics student develops glass cladding. 1957, Hirschowitz: Hirschowitz uses fiberoptics and glass cladding to develop and test the first flexible endoscope (gastroscope) on himself and diagnoses an ulcer in one of his patients. 1959, Buehler: Nitinol alloy is discovered. 1960, Marshall: First flexible ureteroscopy is performed. 1960, Hopkins: An optical system is developed based on cylindrical rodlike lenses to replace the hollow tube through air image system. 1962, McGovern: First transurethral flexible ureteroscopy is performed. 1966, Bush: Argon lasers are used on renal calculi in a cow’s kidney. 1968, Takagi: First photograph of the upper urinary tract is recorded. 1970, Takayasu: First video of the upper urinary tract is recorded. 1977, Goodman: First purposeful use of the rigid ureteroscope is performed. 1978, Lyon: Ureteral dilation and rigid ureteroscopy are performed in women. 1979: Richard Wolf Medical Instruments develops a longer instrument intended for ureteroscopy. 1979, Lyon: Ureteral dilation and rigid ureteroscopy are performed in men. 1980: Karl Storz Endoscopy develops a 50-cm rigid ureteroscope to reach the pelvis. 1981, Das: Ureteral stone basketing is performed under direct vision. 1983, Huffman: Ureteroscopic ultrasonic lithotripsy is performed. 1983, Bagley: A flexible tip ureteroscope is introduced. 1983, Huffman: Baloon dilation of the ureter is performed. 1985, Green: Transureteral electrohydraulic lithotripsy is described. 1988, Dretler: The semirigid ureteroscope is described. 1988, Ritchey: Pulsed dye laser lithotripsy is performed in a pediatric patient. 1994, Grasso: The two-way deflecting ureteroscope with active and passive deflection is used. 1994, Grasso: Tests are performed of a pneumatic lithotripsy transmitted along a nitinol probe in semirigid and flexible ureteroscopes. 1995, Erhard: Ho:YAG laser lithotripsy is first reported. 1997, Murthy: Experience with ureteroscopic pneumatic lithotripsy is reported. 1998, Honey: Experience with new nitinol ureteroscopic baskets is reported.
Ho:YAG laser had durable small fibers, applicability to all stone types, and a wide power selectivity. The Ho:YAG laser also permitted focused coagulation or fulguration through the ureteroscope to control bleeding, to treat superficial tumors, or to incise narrowed areas, such as in ureteral pelvic obstruction or infundibular stenosis.
Technological advancements in ureteroscopic instruments have paralleled advancements in the ureteroscope, revolutionizing the endoscopic treatment of renal calculi and upper tract pathology. Most importantly, these advancements have greatly improved patient safety and postoperative comfort, reducing the need for ureteral dilation and stent placement.
12
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
Durability of the flexible ureteroscope With the expanded applications and capabilities of the flexible ureteroscope, durability of the smaller instruments became an increasing concern. In 1998, White and Moran [50] described that increased use of these small flexible instruments was directly related to the number and types of mechanical failure. By 2000, Afane et al [51] confirmed that flexible ureteroscopes smaller than 9F had an average of 6 to 15 uses before repair was required. More recently in 2002, Pietrow et al [52] assessed methods to improve the longevity of the 7.5F flexible ureteroscope. This group believed that the incorporation of new ureteroscopic accessories (access sheath, nitinol baskets, and a 200 lm holmium laser fiber) would maximize ureteroscope durability, alleviating the most common problem of loss of tip deflection capabilities. Having developed a small ureteroscope with capable working channels and superior vision, manufacturers hope to improve on the durability of these ureteroscopes in the future.
Future Future improvements in ureteroscopy will rely on continued application of new technology. The use of digital imaging and computer-integrated systems should further refine the approach to and documentation of upper tract abnormalities. Smaller instruments with expanded dexterity will allow greater access to difficult to view areas. Wireless image transmission or light sources imbedded within the endoscope could greatly reduce restriction brought about by light and video cords. In the quest to make a smaller more versatile ureteroscope, manufacturers must improve the durability of the ureteroscope by using new materials and designs.
Summary Technology and refinements in urology have prospered with the bonding of engineers and surgeons. The introduction of fiberoptics and the development of the ureteroscope opened the doors to the field of ureteroscopy. Advances in rigid and flexible ureteroscopy with irrigating and working channels have expanded the capability of the urologist to diagnose and treat most abnormalities of the upper tracts in adult and pediatric populations. Instrument development has easily
paralleled the growth and development of the ureteroscope and has improved success, patient safety, and comfort with the incorporation of access sheaths, nitinol materials, and Ho:YAG laser technology. Owing to their minimal morbidity and high success rate, ureteroscopic evaluation and therapeutic interventions in the upper tract represent the gold standard of management. Albert Einstein said, ‘‘There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.’’ Contemporary ureteroscopy is a historical miracle that has opened a vista of endless limits in upper tract endoscopy (Fig. 4, Box 1).
References [1] Young HH, McKay RW. Congenital valvular obstruction of the prostatic urethra. Surg Gynecol Obstet 1929;48:509. [2] Curtiss LE, Hirschowitz BI, Peters CW. J Optic Soc Am 1957;47:117. [3] Colladon D. On the reflections of a ray of light inside a parabolic liquid stream. Comptes Rendus 1842;15,800. [4] Hecht J. City of lights: the story of fiber optics. New York: Oxford University Press; 1999. p. 13–27. [5] Barlow DE. Fiberoptic instrument technology. In: Small animal endoscopy. St. Louis: C.V. Mosby; 1990. p. 1. [6] Baird JL. British Patent Specification No. 20, 969/ 27, 1927. [7] Hansell CW. US Patent No. 1,751,584, 1930. [8] Hecht J. City of lights: the story of fiber optics. New York: Oxford University Press; 1999. p. 60–75. [9] Hirschowitz BI, Curtiss LE, Peters CW, Pollard HM. Gastroenterology 1958;35:50. [10] Marshall VF. Fiber optics in urology. J Urol 1964; 91:110. [11] Takagi T, Go T, Takayasu H, Aso Y. A smallcaliber fiberscope for visualization of urinary tract, biliary tract, and spinal canal. Surgery 1968;64: 1033. [12] Bush IM, Whitmore WF, Lieberman PH, Paananen R, Whitehouse D. Experimental surgical applications of the laser. Presented at the Association for the Advancement of Medical Instrumentation. Boston, 1966. [13] Takayasu H, Aso Y, Takagi T, Go T. Clinical application of fiber-optic pyeloureteroscope. Urol Int 1971;26:97. [14] Goodman TM. Ureteroscopy with pediatric cystoscope in adults. Urology 1977;9(4):394. [15] Lyon ES, Kyker JS, Shoenberg HW. Transurethral ureteroscopy in women: a ready addition to
W.K. Johnston et al / Urol Clin N Am 31 (2004) 5–13
[16]
[17] [18] [19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27] [28]
[29]
[30]
[31]
[32] [33]
the urological armamentarium. J Urol 1978; 119:35. Lyon ES, Banno JJ, Shoenberg HW. Transurethral ureteroscopy in men using juvenile cystoscopy equipment. J Urol 1979;122:152. Das S. Transurethral ureteroscopy and stone manipulation under direct vision. J Urol 1981;125:112. Hopkins HH. US Patent No. 3,257,902, 1966. Huffman JL, Bagley DH, Lyon ES. Treatment of distal ureteral calculi using rigid ureteroscope. Urology 1982;20(6):574. Castro EP, Gorro AP, Delatte LC. Transurethral ureteroscopy: a current urological procedure. Arch Esp Urol 1980;33:445. Huffman JL, Bagley DH, Lyon ES. Extending cystoscopic techniques into the ureter and renal pelvis. JAMA 1983;250(15):2002. Huffman JL, Bagley DH, Lyon ES, Morse MJ, Herr HW, Whitmore WF Jr. Endoscopic diagnosis and treatment of upper-tract urothelial tumors. Cancer 1985;55:1422. Huffman JL, Bagley DH, Schoenberg HW, Lyon ES. Transurethral removal of large ureteral and renal pelvic calculi using ureteroscopic ultrasonic lithotripsy. J Urol 1983;130:31. Green DF, Lytton B. Early experience with direct vision electrohydraulic lithotripsy of ureteral calculi. J Urol 1985;133:767. Lingeman JE, Sonda LP, Kahnoski RJ, Coury TA, Newman DM, Mosbaugh PG, et al. Ureteral stone management: emerging concepts. J Urol 1986;135: 1172. Bagley DH, Huffman JL, Lyon ES. Combine rigid and flexible ureteropyeloscopy. J Urol 1983;130: 243. Takagi T, Go T, Takayasu H, Aso Y. Fiberoptic pyeloureteroscope. Surgery 1971;70:661. Grasso M, Bagley D. A 7.5/8.2F actively deflectable, flexible ureteroscope: a new device for both diagnostic and therapeutic upper urinary tract endoscopy. Urology 1994;43(4):435. Bagley DH, Huffman JL, Lyon ES. Flexible ureteropyeloscopy: diagnosis and treatment in the upper urinary tract. J Urol 1987;138:280. Streem SB, Pontes JE, Novick AC, Montie JE. Ureteropyeloscopy in the evaluation of upper tract filling defects. J Urol 1986;136:383. Kavoussi L, Clayman RV, Basler J. Flexible, actively deflectable fiberoptic ureteronephroscopy. J Urol 1989;142:949. Dretler SP, Cho G. Semirigid ureteroscopy: a new genre. J Urol 1989;141:1314. Ferraro RF, Abraham VE, Cohen TD, Preminger GM. A new generation of semirigid fiberoptic ureteroscopes. J Endourol 1999;13:35.
13
[34] Ritchey M, Patterson DE, Kelalis PP, Segura JW. A case of pediatric ureteroscopic lasertripsy. J Urol 1988;139:1272. [35] Schuster TG, Russel KY, Bloom DA, Koo HP, Faerber GJ. Ureteroscopy for the treatment of urolithiasis in children. J Urol 2002;167:1813. [36] Mulvaney WD. Attempted disintegration of calculi by ultrasonic vibrations. J Urol 1953;70:704. [37] Coates EC. The application of ultrasonic energy to urinary and biliary calculi. J Urol 1956;75:865. [38] Zheng W, Denstedt JD. Intracorporeal lithotripsy: update on technology. Urol Clin North Am 1970; 27:47. [39] Fuchs GJ. Ultrasonic lithotripsy in the ureter. Urol Clin North Am 1988;15:347–59. [40] Grocela JA, Dretler SP. Intracorporeal lithotripsy: instrumentation and development. Urol Clin North Am 1997;24:13. [41] Raney AM. Electrohydraulic ureterolithotripsy. Urology 1978;7:284. [42] Denstedt JD, Clayman RV. Electrohydraulic lithotripsy of renal and ureteral calculi. J Urol 1990; 143:13. [43] Languetin JMP, Jichlinski, et al. The Swiss Lithoclast. J Urol 1900;143:179A. [44] Mulvaney WP, Beck CW. The laser beam in urology. J Urol 1968;99:112–5. [45] Watson GM, Dretler SP, Parrish JA. The pulsed dye laser for fragmenting urinary calculi. J Urol 1997;138:195–8. [46] Hofmann R, Hartung R, Schmidt-Kloiber H, Reichel E. First clinical experience with a Qswitched neodymium:YAG laser for urinary calculi. J Urol 1989;141:275–9. [47] Weber HM, Miller K, Ruschoff J, Gschwend J, Hautmann RE. Alexandrite laser lithotripter in experimental and first clinical application. J Endourol 1991;5:51–5. [48] Johnson DE, Cromeens DM, Price RE. Use of the holmium:YAG laser in urology. Lasers Surg Med 1992;12:353–63. [49] Sayer J, Johnson DE, Price RE, Cromeens DM. Ureteral lithotripsy with the holmium:YAG laser. J Clin Laser Med Surg 1993;11:61–5. [50] White MD, Moran ME. Fatigability of the latest generation ureteropyeloscopes: Richard Wolf vs. Karl Storz [abstract]. J Endourol 2000;15:D33. [51] Afane JS, Olweny EO, Bercowsky E, Sundaram CP, Dunn MD, Shalhav AL, et al. Flexible ureteroscopes: a single center evaluation of the durability and function of the new endoscopes smaller than 9 Fr. J Urol 2000;164(4):1164. [52] Pietrow PK, Auge BK, Delvecchio FC, Silverstein AD, et al. Techniques to maximize flexible ureteroscope longevity. Urology 2002;60(5):784.