Complications associated with ureteroscopy

Single use flexible ureteroscopes: Current status and future directions

Introduction

Single use ureteroscopes are a technological innovation that have become available in the past decade and gained increased popularity. To this end, there are now an increasing number of both benchside and clinical studies reporting outcomes associated with their use. Our aim was to deliver a narrative review in order to provide an overview of this new technology.

Methods

A narrative review was performed to gain overview of the history of the technology's development, equipment specifications and to highlight potential advantages and disadvantages.

Results

Findings from preclinical studies highlight potenial advantages in terms of the design of single use ureteroscopes such as the lower weight and more recent modifications such as pressure control. However, concerns regarding plastic waste and environmental impact still remain unanswered. Clinical studies reveal them to have a non inferior status for outcomes such as stone free rate. However, the volume of evidence, especially in terms of randomised trials remains limited. From a cost perspective, study conclusions are still conflicting and centres are recommended to perform their own micro cost analyses.

Conclusions

Most clinical outcomes for single use ureteroscopes currently match those achieved by reusable ureteroscopes but the data pool is still limited. Areas of continued debate include their environmental impact and cost efficiency.

Comparison of Hemodynamic Response following Spinal Anesthesia between Controlled Hypertensive and Normotensive Patients Undergoing Surgery below the Umbilicus: An Observational Prospective Cohort Study

Background

Hypotension and bradycardia are the most common complications associated with spinal anesthesia and more common in patients with a history of hypertension. Regular use of antihypertensive medications can prevent these complications. The occurrence of hypotension under spinal anesthesia among controlled hypertensive and normotensive patients with age 40 years and above is still debated. The objective of the study was to compare blood pressure and heart rate changes following spinal anesthesia between controlled hypertensive and normotensive patients undergoing surgery below the umbilicus at Black lion hospital, Addis Ababa, Ethiopia, 2020.

Method

A hospital-based prospective cohort study was conducted. A total of 110 elective patients with controlled hypertension (55) and normotensive (55) patients who underwent surgery with spinal anesthesia at black lion hospital during the study period were included. The sample was selected using a systematic random sampling technique. Continuous data of independent and dependent variables were analyzed using an independent sample t-test for normally distributed and Mann–Whitney U-test for nonnormally distributed between the study groups. Categorical variables between the study groups were analyzed using the chi-square test. Descriptive data were displayed using tables and figures. For continuous and categorical variables, a p value <0.05 was considered statistically significant.

Results

The incidence of hypotension in the controlled hypertension group (23.6%) was higher than the normotensive group (7.3%) with p value of 0.018. The occurrence of bradycardia was seen to be 12.7% in each group with a p value >0.05. There was a statistically significant difference in the mean systolic blood pressure, mean arterial pressure, mean heart rate, and vasopressor consumption at the measurement time interval between controlled hypertension and normotensive groups.

Conclusion

Under spinal anesthesia, patients with controlled hypertension are more likely to develop hypotension than normotensive patients, but on the occurrence of bradycardia, there was no statistically significant difference between the two groups.

Role of Minimally Invasive (Micro and Ultra-mini) PCNL for Adult Urinary Stone Disease in the Modern Era: Evidence from a Systematic Review

Purpose of Review

The role of PCNL and the expertise surrounding it has expanded in recent decades. Miniaturisation of equipment and instrument size has formed a part of this innovation. Although an increasing number of studies have been performed on miniaturised PCNL (Mi-PCNL) recently, a critical appraisal on these is lacking. We therefore conducted a systematic review of the literature to evaluate the efficacy, safety and feasibility of Mi-PCNL techniques (< 15 Fr).

Recent Findings

A systematic review was conducted from 1990 to March 2017 on outcomes of Mi-PCNL [micro PCNL (m-PCNL) and ultra-mini PCNL (UMP)] in adult patients. Ten studies (three on m-PCNL and seven on UMP) were included in our study. Across the three studies, 118 patients (mean age 42.2 years, male to female ratio 1.3:1) underwent m-PCNL (4.8 Fr). For a mean stone size of 13.9 mm, a mean stone-free rate (SFR) was 89% and an overall complication rate was 15.2% [Clavien classification I (44%), II (28%), III (28%)], with no Clavien IV or V complications. Across the seven studies, 262 patients (mean age 49.4 years, male to female ratio 1.5:1) underwent UMP (13–14 Fr). For a mean stone size of 18.6 mm, a mean SFR was 88.3% and an overall complication rate was 6.2% [Clavien classification I (57%), II (36%), III (7%)], with no Clavien IV or V complications. While the transfusion rates for m-PCNL was 0.85%, only one case each in m-PCNL and UMP needed conversion to mini PCNL.

Summary

Our review shows that for small- to medium-sized renal stones, Mi-PCNL can yield good stone-free rates whilst maintaining a low morbidity associated with it. There were no Clavien > III complications and no mortality with only one transfusion reported from this minimally invasive technique.

Ureterorenoscopy: avoiding and managing the complications

Retrograde exploration of the ureter and kidneys is currently a widely used and well-established procedure to deal with problems of a diagnostic and therapeutic nature with reduced invasiveness. The process of miniaturizing the instruments combined with the steady improvement in video quality has continuously amplified its potential applications, maintaining the procedure safe and rapid. During an operation, however, unexpected events may condition a change to the programme or determine the onset of even more serious complications. Our aim is to analyze such events and complications and recommend potential solutions to prevent and/or deal with such happenings.

Immediate versus deferred radiological investigation after acute renal colic: a prospective randomized study

OBJECTIVE

The timing of radiological assessment after acute renal colic is controversial. The aim of this study was to investigate the value of immediate versus deferred radiological imaging and to compare morbidity rates after an attack of acute renal colic.

MATERIAL AND METHODS

Between September 2001 and December 2002 all 686 patients with acute renal colic attending our university hospital were registered. Of these, 172 patients rendered pain-free after analgesic injection were randomized to either immediate or deferred radiological investigation. All patients received a questionnaire encompassing questions on consumption of analgesics, impact of symptoms on normal daily activity (including working ability), need for additional emergency department visits and hospitalization. Stone treatments were registered.

RESULTS

The incidence of renal colic was 0.9/1,000 inhabitants per year. In total, 74% of all patients became pain-free after analgesic injection. Morbidity was low among the randomized patients, and did not differ between the immediate or deferred radiological investigation groups. In both groups, the duration of impairment of normal daily activities and analgesic consumption was a median of 2 days. In the immediate group, 14% needed another emergency visit and 4% were hospitalized. Corresponding figures for the deferred group were 15% and 7%. In the immediate group, 17% had stone treatment, compared with 8% in the deferred group.

CONCLUSION

For most patients with acute renal colic, parenteral analgesia resulted in complete symptom resolution. When initial medical treatment was successful, patient morbidity was low. In these patients, immediate radiological imaging did not lead to reduced morbidity compared with radiological imaging after 2-3 weeks.

Handling and prevention of complications in stone basketing

OBJECTIVE

To review the incidence, risk factors, and treatment options of intraoperative and postoperative complications of stone basketing in urology with emphasis on certain principles that must be upheld to prevent those complications.

METHODS

A literature search was performed using the MEDLINE database on stone basketing between 1970 and 2005.

RESULTS

Iatrogenic trauma due to retrieval of a stone is well known but the exact incidence is difficult to ascertain. Rarely, stone basketing can cause major trauma to the ureter, such as avulsion or intussusception, requiring open or laparoscopic intervention for ureteral continuity restoration. Mucosal abrasion, ureteral perforation, and stricture formation have also been described as complications of stone basketing. Occasionally, the engaged or broken basket can provoke anxiety even for experienced urologists. Factors that increase the risk of complications, strategies for repair, and techniques for prevention are discussed extensively.

CONCLUSION

Infrequent, surgical misadventures during stone basketing can occur and must be treated appropriately. Careful attention to instrument selection and surgical techniques and awareness of risk factors and type and site of potential injury are essential to reduce these complications.

An audit of 2273 ureteroscopies--a focus on intra-operative complications to justify proactive management of ureteric calculi

BACKGROUND

At the national Stone Centre we have adopted a proactive management approach involving early ureteroscopy for ureteric calculi. As the efficacy of ureteroscopy is known this study focuses on the low intra-operative complication rate as justification for a proactive management protocol.

PATIENTS AND METHODS

A retrospective study (1987-1997) identified 1936 patients undergoing 2273 ureteroscopies. A database was created from inpatient hospital records. The male to female ratio was 3 to 1, age range was 25 to 84 years.

RESULTS

Twenty-three patients (1%) had an intra-operative complication during ureteroscopy. Immediate ureteric JJ stenting was performed in 16 cases with ureteric injury. Two cases underwent percutaneous drainage and delayed antegrade ureteric stenting, ureteroscopy was terminated because of poor visibility. Five patients (0.22%) underwent open surgery for: ureteric perforation (n = 2); Dormia basket ureteric avulsion (n = 1); impacted Dormia basket and stone (n = 1); and impacted balloon dilator and stone (n = l). Ureteroscopic complications were not related to the level of ureteric calculus.

CONCLUSION

A protocol of proactive management of ureteric calculi facilitates rapid turnover of large patient numbers. This approach is supported by the low intra-operative complication rate, most of which can be managed by further endoscopic procedures. In the event of corrective open surgery a favourable outcome has resulted.

Management of ureteric stones

The contemporary management of ureteric stones is reviewed and evidence based recommendations about treatment are made. Stones measuring less than 4mm in diameter have a high chance of spontaneous passage and the main debate for optimum treatment of larger stones centres around the choice of shock wave lithotripsy or endoscopic management combined with laser fragmentation. Treatment recommendations should be based on patient preference, published evidence, local audit (surgeon expertise and availability of equipment) and cost. Artificial Neural Networks could become a useful tool for prediction of treatment outcome for ureteric stones, and further research is needed to clarify this potential. ESWL is less effective than ureteroscopy but it may prevent the need for more invasive treatment in a substantial proportion of patients. It should only be considered as initial treatment in patients with stones less than 10mm in size. The routine use of stents should be avoided as both fragmentation and stone free rates are noticeably lower. For larger stones, initial laser ureteroscopy serves better both for proximal or distal calculi and is more cost-efficient. Provided that no contraindications for general anaesthesia exist, laser ureterolithotripsy should be regarded as an excellent first line treatment modality for ureteric stone especially in greater stone burden. In the best hands, the outcome for endoscopic management of ureteric stone in all sites is better than ESWL and is cheaper, although equipment, expertise and experience are all required to achieve this superior outcome.

Complications of ureteroscopy

Ureteroscopy has undergone a dramatic evolution over the last two decades. Although ureteroscopic injury is the most common cause of ureteral trauma because of the large number of ureteroscopic procedures performed, improvements in instrumentation and technique have resulted in a reduced incidence of serious complications. Despite significant technologic advances, however, surgical misadventures still occur, some of which have lasting consequences. Careful attention to instrument selection and surgical technique are critical to reduce untoward events related to ureteroscopy. As such, adverse sequelae associated with ureteroscopy should be related to the underlying pathology itself rather than to the treatment.

Are new-generation flexible ureteroscopes better than their predecessors?

OBJECTIVE

To compare two newly designed flexible ureteroscopes with their respective predecessors, to determine whether design advances have overcome the limitation of tip deflection, which may interfere with diagnosis and treatment of lower pole renal pathology.

MATERIALS AND METHODS

Two new-generation flexible ureteroscopes, the DUR-8 Elite (ACMI, Southborough, MA, USA) and 11278AU (Karl Storz Endoscopy, Culver City, CA, USA) were compared with their previous models, the ACMI DUR-8 and the Storz 11274AAU. Active tip deflection and irrigation flow rates with and without various endoscopic tools were assessed. Specifications, purchase prices and repair costs were obtained from each manufacturer. The field of view and screen image size of each ureteroscope were also compared.

RESULTS

The ACMI DUR-8 Elite and the Storz 11278AU had improvements of 79 degrees and 144 degrees, respectively, from their respective older models. Although the tip deflection of all ureteroscopes was compromised by inserting different endoscopic tools, these new instruments were less affected. With a 3 F basket inside the working channel, the ACMI DUR-8 Elite and the Storz 11278AU had only 0.7% and 2.8% loss of upward tip deflection, compared with their older models, at 9.6% and 5.0%, respectively. However, the flow rates of these new instruments were decreased.

CONCLUSION

The new flexible ureteroscopes have significantly better active tip deflection than previous models, both with and without endoscopic instrumentation inserted. However, improved flexibility is at the expense of decreased flow rates and higher purchase costs.

Comparison of the mechanical, flow, and optical properties of contemporary flexible ureteroscopes

OBJECTIVES

New designs have improved the ability of flexible ureteroscopes to assess the upper urinary tract. However, limitations of tip deflection may interfere with diagnosis and treatment of lower pole renal pathologic features and smaller working channels may impair irrigant flow. Our purpose was to compare the new flexible ureteroscopes with prior models to determine whether engineering advances have overcome these problems.

METHODS

Two newly released flexible ureteroscopes, the ACMI DUR-8 Elite and the Storz 11278AU, were compared with four other ureteroscopes, the ACMI DUR-8, Storz 11274AAU, Olympus URF-P3, and Wolf 9F. Active tip deflection, irrigation flow rates, and intraluminal pressures with and without various endoscopic tools were assessed. The specifications, purchase prices, and repair costs were obtained from the individual manufacturers. Also, the field of view and screen image size of each scope were compared.

RESULTS

The ACMI DUR-8 Elite and Storz 11278AU had improved tip deflection of 79 degrees and 144 degrees, respectively, from previous ureteroscopes. Although the tip deflections of all ureteroscopes were compromised by the insertion of endoscopic tools, new ureteroscopes were less affected. With a 3F basket within the working channel, the ACMI DUR-8 Elite and the Storz 11278AU had a loss of downward deflection of only 0.7% and 2.8% compared with a loss of 9.6% and 5.0% for their older models, respectively. However, the flow rate of these new instruments was decreased.

CONCLUSIONS

The new flexible ureteroscopes have significantly better active tip deflection than previous models, both with and without endoscopic instrumentation inserted. However, improved flexibility comes at the expense of a decreased flow rate.

Assessment of stricture formation with the ureteral access sheath

OBJECTIVES

To analyze the long-term incidence of ureteral stricture formation in a series of patients in whom a new-generation ureteral access sheath was used. A new generation of ureteral access sheaths has been developed to facilitate ureteroscopic procedures. However, some have questioned their safety and whether the device might cause significant ureteral trauma.

METHODS

Between September 1999 and July 2001, 150 consecutive ureteroscopic procedures with adjunctive use of an access sheath were performed. A retrospective chart review to April 2002 was done. Of the 150 patients, 130 underwent ureteroscopy for ureteral stones. Patients who underwent endoureterotomy or treatment of transitional cell carcinoma were excluded from this analysis. Sixty-two patients had follow-up greater than 3 months and were included in the analysis. Overall, 71 ureteroscopic procedures were performed, with 9 patients undergoing multiple procedures. Ninety-two percent of the patients had pathologic findings above the iliac vessels. The average patient age was 45.3 years (range 17 to 76), and 70% and 30% of the patients were male and female, respectively. The mean clinical follow-up was 332 days (range 95 to 821), and follow-up imaging was performed within 3 months after ureteroscopy in all patients.

RESULTS

The 10/12F access sheath was used in 8 ureteroscopic procedures (11.2%), the 12/14F access sheath in 56 (78.9%), and the 14/16F access sheath in 7 (9.8%). One stricture was identified on follow-up imaging of 71 procedures performed, for an incidence of 1.4%. The patient developed the stricture at the ureteropelvic junction after multiple ureteroscopic procedures to manage recurrent struvite calculi. The access sheath did not appear to be a contributing factor.

CONCLUSIONS

The results of our series indicate that the ureteral access sheath is safe and beneficial for routine use to facilitate flexible ureteroscopy. However, awareness of the potential ischemic effects with the use of unnecessarily large sheaths for long periods in patients at risk of ischemic injury should be considered. We advocate the routine use of the device for most flexible ureteroscopic procedures proximal to the iliac vessels.

Laser Doppler flowmetric determination of ureteral blood flow after ureteral access sheath placement

BACKGROUND AND PURPOSE

The ureteral access sheath has positively impacted ureteroscopy by decreasing operative times and increasing success rates. However, as previous studies have suggested that large-caliber endoscopes may cause ureteral ischemia, concern has been raised about the impact of access sheath insertion on ureteral blood flow. We sought to determine whether the access sheath compromises ureteral blood supply and, if so, causes ischemic damage to the ureter during ureteroscopic procedures.

MATERIALS AND METHODS

Using a swine animal model, ureteral blood flow was measured with a laser Doppler flowmeter. Eleven ureteral units were randomized into four study groups: those dilated with 10F-12F, 12F-14F, and 14F-16F access sheaths (N = 3 per group) and an undilated control group (N = 2). Blood flow measurements were obtained from the proximal ureter via laser Doppler flowmetry for 70 minutes at 5-minute intervals. Hemodynamic variability was controlled for through intraoperative heart rate and oxygen saturation monitoring, as well as a second Doppler probe that was placed on the animal's skin, from which readings were also taken every 5 minutes. Results were correlated with histopathologic findings.

RESULTS

The control group demonstrated little ureteral blood flow variability over the course of 70 minutes. The study groups that were dilated with sheaths, however, all showed a decrease in ureteral blood flow after access sheath insertion, with the flow in animals dilated with 12F-14F and 14F-16F sheaths dropping below 50% of baseline. This initial drop in blood flow was followed by a gradual increase from nadir toward baseline values over the course of the study. On average, the 14F-16F group reached nadir more quickly and took longer to restore its ureteral blood flow. All animals remained hemodynamically stable throughout the study, showing only minimal variability in heart rate, oxygen saturation, and skin blood flow over the 70-minute experiment. Histologically, there was no evidence of ischemic damage in any of the study groups at 72 hours.

CONCLUSIONS

In this animal model, the access sheath does cause a transient decrease in ureteral blood flow. Nonetheless, compensatory mechanisms of the ureteral wall restore blood flow to near-baseline rates and preserve urothelial integrity, suggesting that use of the ureteral access sheath remains a safe adjunct to flexible ureteroscopy. Because the chronic effects of the access sheath have yet to be elucidated, care must be taken in selecting an appropriate-size sheath for each individual case. Preventive measures may be available to help avoid sheath-related ureteral injury in those patients identified as high risk.

Transitional-cell carcinoma of the renal pelvis: ureteroscopic and percutaneous approach

There are a variety of publications advocating the ureteroscopic or the percutaneous approach for the treatment of transitional cell carcinoma of the renal pelvis. The diagnostic tool of choice for the upper urinary tract and collecting system is the flexible ureteroscope. One of the major concerns about ureteroscopic management of renal disease initially was the lack of flexibility of the instruments and therefore the inability to deal with demanding sites. The advent of new ureteroscopic techniques, as well as the continuous evolution of the technology, have paved the way for safe and effective access to the upper urinary tract. In the hands of an experienced urologist, such procedures can provide reliable treatment options for small upper urinary tract lesions. Coupling minimal morbidity with ever-improving optics and flexibility, the ureteroscope of today leaves no area of the urinary tract unseen. In patients with bulky tumors or in whom easy access and resection is not possible ureteroscopically, the percutaneous approach to the renal pelvis, although more invasive, provides a better working environment. Clearly, the most difficult aspect of ureteroscopic access to the lower pole is not just visibility but the loss of deflection caused by passage of various instruments through the working channel. Direct access via percutaneous approach with a large resectoscope avoids these problems.

Routine radiologic surveillance for obstruction is not required in asymptomatic patients after ureteroscopy

OBJECTIVE

A retrospective medical record review was performed with the goal of determining the need for radiologic evaluation after ureteroscopy.

PATIENTS AND METHODS

Of 183 patients undergoing ureteroscopic procedures at our institution between 1989 and 1993, 131 underwent postoperative radiologic studies capable of diagnosing ureteral obstruction. Of these patients, 110 (84%) were asymptomatic after the procedure, and radiologic procedures capable of displaying obstruction were performed at a median of 60 days (mean 73 days; standard deviation 189 days) after ureteroscopy.

RESULTS

None of these asymptomatic patients displayed obstruction at the time of the routine follow-up radiologic procedure. Of those 21 patients (16%) who experienced flank pain subsequent to ureteroscopy, 13 were found to have ureteral obstruction secondary to ureteral calculus. One patient (1/131 or 0.8%) was found to have a ureteral stricture, which occurred after a full-thickness ureteral injury. All cases of postoperative obstruction were heralded by a concomitant display of flank pain.

CONCLUSION

Routine postoperative radiologic studies are not necessary in surveillance for obstruction in the asymptomatic postureteroscopy patient, as obstruction should become evident by virtue of flank pain. The exception to this practice may be in patients experiencing a ureteral perforation intraoperatively, who may be at greater risk of stricture.

Secondary ureteroscopy: results and management strategy at a referral center

PURPOSE

In an era when extracorporeal shock wave lithotripsy occupies a dominant place in the treatment of urolithiasis ureteroscopy retains an important role in certain circumstances. While often a definitive procedure, ureteroscopy can be associated with potential risks and complications. The treatment of patients who have undergone a failed attempt at ureteroscopic stone retrieval or have a complication may be complex. As a tertiary care stone referral center we review our experience with performing salvage ureteroscopy following a previous unsuccessful attempt at endoscopic stone removal.

MATERIALS AND METHODS

Between May 1990 and February 1996, 79 patients were referred following an unsuccessful attempt at retrograde endoscopic or basket manipulation for ureteral calculi. A retrospective review of the outcomes of these patients was conducted. Of the patients 11 presented with associated complications, which included ureteral perforation (4), intramural false passage (1) and fever or sepsis (6). Complications were managed by early establishment of urinary tract drainage by stenting or nephrostomy. Among patients without complications elective salvage ureteroscopy was performed.

RESULTS

Ureteroscopy was used in 79 patients with a successful outcome (stone-free) in 75 (95%). Followup imaging with renal ultrasound or excretory urography at least 3 months after secondary ureteroscopy was available in 65 patients and showed no evidence of hydronephrosis or delayed stricture formation.

CONCLUSIONS

Treating the patient who undergoes a failed attempt at ureteroscopy may be problematic and requires access to a wide array of endourological equipment. Each subsequent treatment should be individualized with consideration given to stone size, location and general health. In the presence of a ureteral injury establishment of early urinary tract drainage is essential. Following stabilization, secondary ureteroscopy can be performed yielding high stone-free rates with minimal complications.

Flexible ureteroscopy: Washington University experience with the 9.3F and 7.5F flexible ureteroscopes

PURPOSE

Recent advances in the design of flexible ureteroscopes have resulted in smaller caliber instruments. We review our experience with the smaller flexible ureteroscopes, and compare the efficacy and efficiency of the newer 7.5F to the standard 9.3F flexible instruments.

MATERIALS AND METHODS

Between January 1991 and 1995, 69 male and 41 female patients (mean age 57 years, range 16 to 91) underwent 116 retrograde flexible ureteroscopic procedures for a variety of diagnostic and therapeutic indications. A 9.3F ureteroscope (group 1) was used in 71 patients and a 7.5F instrument (group 2) was used in 39.

RESULTS

Patients in group 2 received sedation analgesia significantly more often than those in group 1 (56 versus 35%, p = 0.04). Active dilation of the ureteral orifice was required less often in group 2 (22.5%) than in group 1 (58%, p < or = 0.05). The total success rate for stone management, and diagnosis and/or treatment of an upper urinary tract lesion was 98.3 and 100%, respectively, in group 1, and 90 and 100%, respectively, in group 2 (p = 0.17). Of the 71 patients in group 1, 17 (24%) were treated on an outpatient basis, compared to 14 of 39 (49%) in group 2 (p = 0.16). No intraoperative or postoperative major complications were encountered in either group. Group 2 required less postoperative analgesia (p = 0.05). No ureteral stricture occurred in either group at an average followup of 9.5 months postoperatively (range 2 to 35).

CONCLUSIONS

For ureteral and renal pathological conditions the 7.5F ureteroscope is as effective as the 9.3F instrument diagnostically and therapeutically. The 7.5F ureteroscope usually can be used with sedation analgesia. Also, the smaller 7.5F ureteroscope is associated with less need for active ureteral dilation, minimal postoperative discomfort and a brief hospital stay.

The fate of the iatrogenic retroperitoneal stone

Ureteral perforation with resultant retroperitoneal stone expulsion is a recognized complication of ureteroscopy. In a 5-year retrospective review of 400 cases we identified a 1.3% incidence of iatrogenic retroperitoneal stone dislodgment. Average followup was 21 months. Four cases were managed with observation and 1 required surgical correction of a ureteropelvic junction stricture. We discuss the management of this problem, which begins with thorough radiographic documentation in the perioperative period. Aggressive ureteroscopic manipulation and attempted stone retrieval are not warranted, and a ureteral stent should be placed. Radiographic followup and clinical observation confirm the low morbidity associated with retroperitoneal urinary stones. Patient understanding of the extra-ureteral stone location is essential to avoid misdiagnosis and mismanagement by uninformed physicians in the future.

Laser lithotripsy with the Candela MDL-2000 LaserTripter

The Yorkshire Lithotriptor Centre acquired a Candela MDL-2000 LaserTripter and a 7.2F Miniscope in February 1990. We present the results obtained in the first 200 patients referred for treatment of ureteric stones or stone fragments. Of 175 patients who were evaluable, 58 had upper ureteric stones, 41 mid-ureteric and 76 lower ureteric stones. Successful laser fragmentation was achieved in 77% of cases and a further 10% were rendered stone-free by the push-bang technique. Ureterolithotomy was required in 9% and the major complication rate was 4%. Ureteric dilatation was not used. Maximum laser energy was required to break 19% of the stones, but no stone was encountered which could not be broken. Laser lithotripsy with this system is highly effective at all levels of the ureter; it is safe and it complements ultrasound-guided extracorporeal lithotripsy.

Clinical experience with flexible ureteropyeloscopy

Flexible ureteroscopes and their accessory working instruments have undergone tremendous design advances since the earliest reports in the 1960s. These changes have allowed for the expansion of indications for flexible ureteroscopy with the emphasis now on therapeutic and not just diagnostic applications. This report covers 290 procedures done with actively deflectable, flexible ureteroscopes on 222 patients. Followup averaged 11.2 months in 228 patients, while the remaining 62 were followed by the original referral center. Included were 154 procedures for stones and 79 for tumors or filling defects. Of the procedures 149 were performed with the patient under local anesthesia with sedation, while 128 were done with use of general anesthesia. The procedure was done in only 22% of the cases for purely visual diagnosis without any interventional manipulation. More than 42% of the cases involved stone retrieval or lithotripsy, in which case the laser was most commonly used (56 cases). The total success rate was 95.5%, and the most common complications were colic or pain in 9% and fever in 6.9%. A stricture developed in 2 patients. A stent was left in more than 93% of the patients and the usual postoperative stay was less than 3 days. With the introduction of even more improved instruments, flexible ureteroscopy should continue to gain ground as an option for the management of upper urinary tract pathology.

Extracorporeal shock wave lithotripsy of ureteric stones with the Modulith SL 20

A series of 138 patients with ureteric calculi was treated by in situ extracorporeal shock wave lithotripsy (ESWL) during the clinical introduction of the Modulith SL 20. This machine represents a newly developed lithotriptor with an electromagnetic cylinder as shock wave source and a dual localisation system consisting of in-line ultrasound and an integrated fluoroscope C-arm. During the first 2 months, 12 patients (phase 1) were treated under ultrasound localisation alone; during the next 5 months, 37 patients (phase 2) were treated using dual imaging modalities with reduced peak pressure (max. 18 kV = 800 bar); during the final 7 months, 89 patients (phase 3) were treated under ultrasonic and fluoroscopic localisation combined with an increased maximal shock wave pressure (20 kV = 1024 bar). The introduction of fluoroscopic targeting (phases 2 and 3) resulted in satisfactory localisation of calculi in the mid-ureter, previously limited by use of only coaxial ultrasound. The extension of stone localisation to the whole length of the ureter was associated with a marked decrease in treatment time, reflecting the easy handling of the dual localisation system. The rise in generator voltage (phase 3) improved the disintegration rate from 81% (phase 2) to 85%, whereas the number of impulses remained unchanged. However, the rate of auxiliary procedures following ESWL (adjuvant and curative) was reduced from 33% (phase 2) to 24.5%. Thus the Modulith SL 20 in its final design enables in situ ESWL to be the treatment of choice for all ureteric calculi, rendering special positioning techniques or multiple treatment unnecessary.

Transurethral ureterorenoscopic lithotripsy and retrieval of ureteric calculi under local anaesthesia and sedation

Under strict indications, ureterorenoscopic (URS) lithotripsy was used to treat ureteric calculi in 61 patients under local anaesthesia and sedation in a 2-year period ending November 1988. Assessments of success and discomfort of the procedure were made. Stone retrieval was accomplished in 48 patients (78% success rate) and a mean pain score of 6 was recorded in a scale from 0 to 10. It was concluded that performing URS under local anaesthesia is an acceptable alternative.

Ureteroscopic manipulation of stones in the ureter: four years experience

Our experience of 223 ureteroscopies and stone manipulations is reported. Stone removal was successful in 82% of the cases whereof the stones were pushed back into the renal pelvis and subsequently managed with percutaneous nephrolithotomy or extracorporeal shock wave lithotripsy in 24%. For distal stones the success rate was 88%. Reasons for failure were acute obstruction of the ureter and previous surgery or irradiation to the pelvis. In six cases (4%) strictures requiring treatment developed secondary to ureteroscopy. Ureteroscopy can be a tedious and difficult procedure with a considerable learning time. In experienced hands the rate of serious complications is low and the procedure is an alternative in the treatment of ureteric stones, especially in the distal part of the ureter.

Ultrathin flexible endoscopes for ureteroscopy. A preliminary experimental and clinical study

Recent advances in fiberoptic technology have resulted in the development of endoscopes with an outer diameter of less than 6 F, including an irrigating or working channel. After preliminary testing of these ultrathin fiberscopes for ureteroscopy on 6 pigs, 17 patients were examined during routine retrograde pyelography. Prototypes of flexible endoscopes without an actively deflectable tip and an outer diameter of 5.5 F (= 1.8 mm) and a 1.5 F (= 0.5 mm) channel were used. Fine-needle aspiration cytology was obtained through the channel. The feasibility, performance and benefits of ureteroscopy with ultrathin, flexible endoscopes were evaluated. At present the lack of maneuverability and the fragility of the fiberscopes limit this method. Yet its routine clinical use, in addition to retrograde ureteropyelography under local anesthesia, shows great promise.

Long-term results of transurethral lithotripsy with the rigid ureteroscope: injury of intramural ureter

We treated 208 patients with ureteral calculi via transurethral lithotripsy using the rigid ureteroscope between March 1985 and April 1988. A total of 220 ureteroscopic procedures was performed in 217 ureters. Complete removal was achieved after 180 procedures (81.8%) and incomplete removal was achieved after 9 (4.1%). In 31 cases (14.1%) the stone could not be removed because of various reasons. Ureteral disruption was observed in 1 case (0.5%), which was treated successfully with reconstruction. Ureteral perforation occurred in 15 cases (6.8%) and was treated successfully except for 1 patient (0.5%) in whom ureteral stricture was observed requiring reconstruction. From long-term followup of sequential excretory urography and voiding cystography, mild stricture at the vesical end of the ureter was noted in 3 of 86 ureters (3.5%) and vesicoureteral reflux was noted in 7 of 73 (9.6%). These results indicate that the injury to the intramural ureter might arise from the passage of the ureteroscope resulting in stricture and vesicoureteral reflux.

Endoscopic treatment of urinary tract calculi

Removal of urinary tract calculi by endourological techniques is now widely practised and has reduced the indications for open surgical removal to a minority of cases. A review of 270 consecutive patients who presented to the Meath Hospital Urology department with urinary tract calculi and were treated by percutaneous or transurethral endoscopy is herein reported. The rates of successful clearance of renal (95%) and ureteric (78%) calculi compare well with previous reports. The majority of complications were minor and a low overall complication rate was experienced at ureterorenoscopy. In our experience, endourological treatment of urinary tract calculi is successful, efficient and safe and is the recommended approach to urinary tract calculi that require surgical intervention.

Is extracorporeal shockwave lithotripsy suitable treatment for lower ureteric stones?

Forty patients with lower ureteric calculi for which intervention was considered desirable have been treated by in situ extracorporeal shockwave lithotripsy (ESWL) on the Dornier HM3 Lithotripter using a modified technique. Stone localisation was satisfactory in all patients. Adequate disintegration was achieved in 90% of patients following one treatment; 34 patients have been followed up for at least 3 months and 27 of these are stone-free (79%). Treatment failed in 4 patients and 2 of these had dense lower ureteric stone streets as a result of previous ESWL. The retreatment rate, post-treatment auxiliary procedure rate and complication rate were minimal. It was concluded that in situ ESWL is an effective and safe method for treating certain selected lower ureteric stones and should be considered as a feasible alternative to the more conventional methods of treatment.

Primary choice of intervention for distal ureteric stone: ureteroscopy or ESWL?

Either transurethral ureteroscopy (URS) or extracorporeal shock wave lithotripsy (ESWL) was the primary method of intervention in two series of patients presenting consecutively with stones located in the ureter distal to the radiological marking of the sacroiliac joint. Of 65 patients treated by URS, successful evacuation of the major part of the stone was achieved in 97% in one or two sessions. Of those subsequently attending for review, 93% proved stone-free but 3% required surgery for serious complications. In the ESWL series of 53 patients, successful stone fragmentation was recorded in 94%, with 2 patients requiring a supplementary endourological or surgical procedure. No significant complications were related to ESWL and 90% of those followed up after successful ESWL proved stone-free at 6 weeks. In uncomplicated cases, the mean procedure time for ESWL was one-third of that required for URS and the hospital stay one-half. It is suggested that ESWL should be the primary method of intervention in patients with distal ureteric stone, with URS reserved for the small number that prove refractory to such treatment.

Ureteroscopic stone manipulation in the upper third of ureter and the pelvicaliceal system

During the period of January 1984 to March 1987, a total of 15 patients with upper third ureteric calculi and 115 patients with renal calculi were treated by percutaneous nephrolithotomy (PCNL), transurethral ureteroscopy (TUU) or open surgery. In all patients, endoscopic techniques were the primary modalities of therapy. In 15 patients with upper third ureteric calculi and in 22 patients with 27 calculi in the pelvicaliceal system (five had bilateral calculi), TUU was carried out. The success rate was 67% for calculi in the upper third of ureter and 44% for calculi in the pelvicaliceal system. No persistent strictures or other serious complications were encountered. We conclude, that TUU, in experienced hands, could be considered for proximal ureteric calculi and for certain renal calculi, especially in poor risk patients and patients with only one kidney.

Ureteroscopy and ureteric calculi: how useful?

The results of management in 134 patients admitted to hospital during 1985 with ureteric colic are presented in relation to the size and position of a ureteric stone. Spontaneous passage of a stone occurred in 100 patients and 34 required surgical intervention. Stones measuring 5 mm or less in maximum dimension passed spontaneously in 92% of cases; stones measuring 6 mm or more had only a 28% chance of passing. Of 34 surgical procedures 19 were endoscopic. In three cases a stone was removed under vision with ureteroscope and Dormia basket. In five patients ureteric dilatation before attempted ureteroscopy permitted later passage of the stone. In 1986 similar results were obtained with ureteroscopic stone removal performed in three cases. Fewer open operations and more Dormia basket extractions were performed in 1986. In this series the size of the stone was closely related to outcome. The high chance of spontaneous passage (75% in 1985 and 84% in 1986) puts the need for surgical intervention, and in particular ureteroscopy, into perspective in the management of patients with ureteric colic.