A new generation of semirigid fiberoptic ureteroscopes

Ureteroscopy from the recent past to the near future

Stone surgery is one of oldest surgical practices undertaken by man. Hippocrates refused to let his followers "cut for the stone" and it was only in February 1980, when the first human trial of shock wave therapy on a renal stone was performed with success that a new era in minimally invasive treatment (surgery) for stones was opened up and this condemnation was finally resolved in the Hippocratic Oath. Endoscopy, using natural orifices, supported by anaesthesia, incremented by technology and with access to all points along the urinary tract, began by competing with ESWL, but is now the treatment of choice in most cases. As far as we know humans have always had stones. First, lithiasis was endemic bladder stones in children, now it is renal in general. Added to this a number of well-known risk factors, a rapid increase in obesity in the population, as well as bariatric surgery for its treatment, are causing an increase in the prevalence and recurrence of lithiasis everywhere. A short history of the advances made with the introduction and development of the ureteroscope, along with auxiliary devices, will show why this is the preferred technique at the moment for treating lithiasis in general and for treating stones in pregnant women, children and the obese in particular. Being a minimally invasive surgery, with a low morbidity and a very high efficiency and stonefree rate, has become established as a clear future technique for both adults and children. This development is not only due to technological advancements, but also to the routine use of the Holmium: YAG LASER for intracorporeal lithotripsy, capable of destroying any stone regardless of its composition or location, surpassing the ability of any other lithotripter. It is also due to the development of devices that allow access to the ureter and all parts of the kidney, as well as auxiliary aids to assist in the handling of stones during treatment. New LASERs, robotic control of the fdURS and digital imaging, as well as disposable devices, have had and, indeed, continue to have a unique impact on future development in this field. However, success will continue to depend on the careful choice of fURS, energy source and ancillary instruments obtained by the urologist during both real life and virtual training in human simulators.

Endoureterotomy for Ureteral Stricture: A Retrospective Study of Holmium Versus Thulium Lasers

Background:

To compare the results of endoureterotomy for benign ureteral strictures by using holmium: yttrium-aluminum-garnet (Ho:YAG) and thulium lasers.

Methods:

A total of 25 patients (15 men and 10 women, mean age: 49.16 years) underwent endoureterotomy with either Ho:YAG or thulium lasers for benign ureteral strictures (13 proximal, 3 middle, and 9 distal), using semirigid ureteroscopy and a 365-μm fiber (Ho-YAG laser) at 1.2 J/pulse and 10 Hz, or a 300-μm fiber (thulium laser) at 8W to 15W. Following incision, a 7-Fr double-J ureteral stent was left for 4 to 6 weeks. Thereafter, patients were followed-up using ultrasonography and/or intravenous urography at 3- to 6-month intervals.

Results:

Success was defined as the absence of symptoms, plus radiographic resolution of obstructions, as assessed by diuretic renography and/or intravenous urography. With a mean follow-up of 43 months, success was achieved in 10 (52.6%) of 19 patients treated with Ho:YAG laser and in 5 (83.3%) of 6 patients treated with thulium laser. A total of 10 patients developed recurrent strictures and were considered to have treatment failures. Stricture length and the severity of hydronephrosis were correlated with successful outcome. Sex, etiology, side, and stricture location did not predict outcome.

Conclusions:

Although endoureterotomies using Ho:YAG and thulium lasers had equal efficacy, our analysis revealed that a patient with longer stricture length or severe hydronephrosis is more suitable to receive thulium laser. This general laser procedure is recommended as a safe therapeutic option for the initial management of patients presenting with benign ureteral strictures because it is less invasive.

Semirigid ureteroscopy of the proximal ureter can be aided by external lower-abdominal pressure

BACKGROUND AND PURPOSE

Smaller semirigid ureteroscopes with large working channels and excellent optics are widely available. Ureteroscopic treatment of upper-ureteral stones has become increasingly popular, although flexible ureteroscopy is more frequently the method of choice. Access to the upper ureter with a semirigid ureteroscope (SR-URS) can be challenging and hazardous, especially when negotiating the iliac vessels. We sought to determine whether lower-abdominal pressure (LAP) facilitated SR-URS access to the upper ureter for safe laser lithotripsy.

PATIENTS AND METHODS

Thirty-two consecutive patients who underwent ureteroscopic management of upper- ureteral stones were evaluated. Twenty-four (75%) were male; seventeen (53%) had a right-sided stone. The mean largest stone diameter was 10.2 +/- 4.6 mm. These 32 patients were compared with a matched cohort of patients who underwent SR-URS procedures without the use of LAP.

RESULTS

Access to the upper ureter was possible in 30 patients (94%). The LAP was helpful in 18 patients (56%): it facilitated passage of the SR-URS in 16 patients (50%) and laser fiber placement in 11 cases (34%). Access to the upper ureter was possible in all women. The mean operative time was 54 minutes in the LAP group and 75 minutes in the matched cohort without LAP (P = 0.026). There were no significant deformities of the SR-URS and no complications.

CONCLUSIONS

Contrary to popular practice, the upper ureter can be accessed safely and efficiently with a 7.5F SR-URS in nearly all patients. Lower-abdominal pressure can be helpful to negotiate passage of the endoscope over the iliac vessels or to place the laser fiber on stones.

Ureteroscopes: flexible, rigid, and semirigid

Since its introduction, the ureteroscope has undergone significant improvements. Using the currently available rigid, semirigid, and flexible ureteroscopes and working instruments, urologists can diagnose and treat lesions throughout the upper urinary tract. Over the past 25 years, the ureteroscope in combination with shock wave lithotripsy has transformed the diagnosis and treatment of more than 90% of upper urinary tract pathology from an open to an endourologic procedure. With endoscope manufacturers continually incorporating new technology into their ureteroscopes, future models will undoubtedly provide better optics, increased durability, and improved capabilities, resulting in greater success when urologists perform endoscopic forays into the upper urinary tract.

The evolution and progress of ureteroscopy

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).

Retrograde ureteroscopic endopyelotomy

Several different procedures can be used to treat UPJ obstruction. Retrograde ureteroscopic endopyelotomy provides a safe and adequate first line of treatment for this condition. With the advent of smaller ureteroscopes and ancillary devices, this technique has evolved to include children. Adherence to strict endourologic principles and direct visualization make retrograde ureteroscopic endopyelotomy a safe and effective treatment modality. This procedure represents an extension of the basic endoscopic skills of the urologist, creating a short learning curve and wide margin of safety.

Characterization of intrapelvic pressure during ureteropyeloscopy with ureteral access sheaths

OBJECTIVES

To evaluate the impact of the ureteral access sheath on intrarenal pressures during flexible ureteroscopy in light of the recent resurgence in their use. As such, using human cadaveric kidneys, we studied changes in intrarenal pressure in response to continuous irrigation at different pressures with and without access sheaths of various sizes and lengths.

METHODS

This study was performed using seven cadaveric kidneys. In three kidneys the study was done in situ with a 7.5F flexible ureteroscope (URS) passed by itself and then passed through a 10/12F sheath (35 and 55 cm in length), whereas, in four kidneys, due to narrowing of the intramural ureter, the study was done ex vivo using the unsheathed URS and then passing the 7.5F flexible URS via the 10/12F, 12/14F, and 14/16F sheaths (all 35 cm in length). A 10F Cope loop pyelostomy was placed to measure intrapelvic renal pressure. Three sets of 3-minute readings (ie, flow and intrarenal pressure) were taken with the tip of the URS at the distal ureter, middle ureter, and renal pelvis (just above the ureteropelvic junction); the entire process was done at three different irrigant pressure settings: 50, 100, and 200 cm H(2)O. Irrigant flow and intrarenal pressures were measured at all three settings using the URS passed without a sheath and then with the URS passed through the various sheaths positioned at the distal ureter, middle ureter, and renal pelvis.

RESULTS

With all of the sheaths, intrapelvic pressure remained low (less than 30 cm H(2)O), and there was a 35% to 80% increase in irrigant flow versus the control unsheathed URS. With the sheath in place, the majority of the irrigant drained alongside the URS and out the sheath. Flow and pressure with the 12/14F sheath were equivalent to the 14/16F sheath.

CONCLUSIONS

The 12/14F access sheath provides for maximum flow of irrigant while maintaining a low intrarenal pelvic pressure. Even with an irrigation pressure of 200 cm H(2)O, renal pelvic pressure remained below 20 cm H(2)O.

Routine ureteral stenting is not necessary after ureteroscopy and ureteropyeloscopy: a randomized trial

BACKGROUND AND PURPOSE

Retrospective studies have suggested that routine stenting can be avoided following ureteroscopy. We prospectively analyzed the need for routine ureteral stent placement in patients undergoing ureteroscopic procedures.

PATIENTS AND METHODS

Fifty-five consecutive patients (60 renal units) were randomized into either a stent or a no-stent group following ureteroscopy with either a 7.5F semirigid or a 7.5F flexible ureteroscope for treatment of calculi (holmium laser or pneumatic lithotripsy) or transitional-cell carcinoma (holmium laser). Intraoperative variables assessed included total stone burden, the need for ureteral dilation, and overall operative times. All patients were evaluated by questionnaire on postoperative days 0, 1, and 6 with regard to pain, frequency, urgency, dysuria, and hematuria.

RESULTS

Of the 60 renal units treated, 38 received ureteral stents (mean 5.2 days), and 22 were treated without a stent. All 10 patients requiring ureteral balloon dilation had stents placed and were removed from the analysis. There was no significant difference between the groups with regard to age, sex, or stone burden. Operative time was decreased in the no-stent group (43 minutes v 55 minutes; P = 0.013). Flank discomfort was significantly less common in the no-stent group on days 0, 1, and 6 (P = 0.004, P = 0.003, P < 0.001, respectively), as was the incidence of suprapubic pain on day 6 (P = 0.002). There was no difference in urinary frequency, urgency, or dysuria between the groups on postoperative day 1, but all these symptoms were significantly reduced in the no-stent group on day 6 (P < 0.001, P < 0.001, P = 0.002, respectively). There was no significant difference in patient-reported postoperative hematuria in either group. One patient in each group developed a urinary tract infection. One patient in the no-stent group developed ureteral obstruction in the postoperative period that necessitated stenting, and one patient in the stent group experienced stent migration necessitating removal.

CONCLUSIONS

Routine ureteral stenting does not appear to be warranted in those patients who do not require ureteral dilation during ureteroscopic procedures. Ureteral stent placement following ureteroscopy may be avoided, thereby reducing operative time, surgical costs, and patient morbidity.

Endoscopic ureteral incision using the holmium:YAG laser

BACKGROUND

We reviewed the results of endoscopic ureteral incision for benign ureteral stricture, ureteropelvic junction obstruction and ureteroenteroanastomotic stricture using the holmium laser.

METHODS

We carried out endoscopic ureteral incision using the holmium laser through an 8-Fr semirigid or 6.9-Fr flexible ureteroscope on 17 ureters in 15 patients. Balloon dilatation was not necessary before insertion of the ureteroscope. The stricture was incised with the holmium laser using a 200-365 microm fiber through the working channel of the ureteroscope. After completion of the incision, a 12-Fr double-J catheter was left for 6 weeks. Thereafter patients were followed by renal scan and/or ultrasound and excretory urography at 3-6 month intervals.

RESULTS

The mean operative time was 65 min (18-135 min). The stricture resolved completely in 86.7% of cases at an average follow up of 20.5 months (11-32 months).

CONCLUSIONS

The holmium laser endoscopic ureteral incision was associated with a good outcome in our series. We recommend this procedure to be employed initially because it is less invasive and has a favorable outcome.