Hassan Razvi

HOLMIUM: YAG LASER LITHOTRIPSY FOR UPPER URINARY TRACT CALCULI IN 598 PATIENTS

PURPOSE We assessed the effectiveness and safety of holmium:YAG laser lithotripsy for managing upper urinary tract calculi in a prospective cohort of 598 patients. MATERIALS AND METHODS Ureteroscopic holmium:YAG laser lithotripsy was performed in 598 patients between 1993 and 1999. Calculi were located in the distal ureter in 39.6% of cases, mid ureter in 18.6%, proximal ureter in 32.4% and kidney in 9.4%. Patients were treated on an outpatient basis with various flexible and semirigid endoscopes. Of the cases 59% were referred as previous treatment failures. Patients were assessed 6 to 12 weeks postoperatively with repeat plain x-ray and ultrasound or excretory urography for late obstructive complications. RESULTS The overall stone-free rate was 97%. As stratified by location, the stone-free rate was 98% in the distal ureter, 100% in the mid ureter, 97% in the proximal ureter and 84% in the kidney. Fragmentation was incomplete in 6% of cases and secondary intervention was required in 6%. The overall complication rate was 4%. New onset ureteral stricture developed postoperatively in 0.35% of patients. CONCLUSIONS Holmium:YAG laser lithotripsy is a highly effective and safe treatment modality for managing ureteral and a proportion of intrarenal calculi on an outpatient basis. The effectiveness and versatility of the holmium laser combined with small rigid or flexible endoscopes make it our modality of choice for ureteroscopic lithotripsy.

Intracorporeal Lithotripsy With the Holmium:YAG Laser

PURPOSE Preliminary evaluations of the holmium:YAG laser have demonstrated a variety of potential urological applications, including ablation of soft tissue lesions as well as stone fragmentation. We present our experience with the holmium:YAG laser for intracorporeal lithotripsy of urinary calculi. MATERIALS AND METHODS During a 24-month period 75 patients underwent 79 laser procedures, including retrograde ureteroscopy for ureteral calculi (71) and fragmentation of caliceal stones remote from the nephrostomy tract during percutaneous nephrolithotripsy (8). RESULTS Complete stone fragmentation without need for additional procedures or lithotripsy was achieved in 85% of the cases. Treatment failures included 1 case of stone migration, 7 incomplete fragmentation requiring other lithotripsy devices and 3 laser malfunction. One ureteral perforation occurred when the laser was activated without direct visual guidance. CONCLUSIONS The holmium:YAG laser has demonstrated its efficacy as a method of intracorporeal lithotripsy. Advantages include ability to fragment stones of all composition, and the multipurpose, multispecialty applications of the holmium wavelength. This laser has potential soft tissue effects, and careful attention to technique during lithotripsy is required to avoid ureteral wall injury.

Ureteroscopy and holmium:YAG laser lithotripsy: an emerging definitive management strategy for symptomatic ureteral calculi in pregnancy

Abstract Objectives. To review the results of holmium laser lithotripsy in a cohort of patients who presented with symptomatic urolithiasis in pregnancy. Symptomatic urolithiasis in pregnancy that does not respond to conservative measures has traditionally been managed with ureteral stent insertion or percutaneous nephrostomy. Holmium:yttrium-aluminum-garnet (YAG) laser lithotripsy using state-of-the-art ureteroscopes represents an emerging strategy for definitive stone management in pregnancy. Methods. A retrospective analysis was conducted at two tertiary stone centers from January 1996 to August 2001 to identify pregnant patients who were treated with ureteroscopic holmium laser lithotripsy for symptomatic urolithiasis or encrusted stents. Eight patients with a total of 10 symptomatic ureteral calculi and two encrusted ureteral stents were treated. The mean gestational age at presentation was 22 weeks. The mean stone size was 8.1 mm. The stones were located in the proximal ureter/ureteropelvic junction (n = 3), midureter (n = 1), and distal ureter (n = 6). Results. Complete stone fragmentation and/or removal of encrusted ureteral stents were achieved in all patients using the holmium:YAG laser. The overall procedural success rate was 91%. The overall stone-free rate was 89%. No obstetric or urologic complications were encountered. Conclusions. Ureteroscopy and holmium laser lithotripsy can be performed safely in all stages of pregnancy, providing definitive management of symptomatic ureteral calculi. The procedure can be done with minimal or no fluoroscopy and avoids the undesirable features of stents or nephrostomy tubes.

The microbiome of the urinary tract—a role beyond infection

Urologists rarely need to consider bacteria beyond their role in infectious disease. However, emerging evidence shows that the microorganisms inhabiting many sites of the body, including the urinary tract—which has long been assumed sterile in healthy individuals—might have a role in maintaining urinary health. Studies of the urinary microbiota have identified remarkable differences between healthy populations and those with urologic diseases. Microorganisms at sites distal to the kidney, bladder and urethra are likely to have a profound effect on urologic health, both positive and negative, owing to their metabolic output and other contributions. Connections between the gut microbiota and renal stone formation have already been discovered. In addition, bacteria are also used in the prevention of bladder cancer recurrence. In the future, urologists will need to consider possible influences of the microbiome in diagnosis and treatment of certain urological conditions. New insights might provide an opportunity to predict the risk of developing certain urological diseases and could enable the development of innovative therapeutic strategies.

Management of urinary calculi during pregnancy.

Renal calculous disease is an infrequent but not insignificant occurrence during pregnancy. In 50 to 80% of the cases conservative management is appropriate and the stone will pass spontaneously. Should intervention be required, recent advances in stone management and techniques for urinary tract drainage may be successfully applied to the obstetric population. Concerns regarding surgical and anesthetic risks, and the potential hazards of radiation exposure during pregnancy favor a minimally invasive approach with definitive treatment late in pregnancy or post partum. We review our experience during a 5-year period in managing 29 patients with urinary calculous disease during pregnancy. Based on our experience and review of the literature an algorithm for treatment of urolithiasis during pregnancy is proposed.

Soft-tissue applications of the holmium:YAG laser in urology

The holmium:YAG laser possesses both ablative and hemostatic properties and in preliminary clinical use has demonstrated many potential urologic applications. We review our initial experience in treating a variety of soft-tissue lesions of the urinary tract with this laser. A total of 51 patients underwent 53 procedures including superficial bladder tumor ablation (25), incision of ureteral stricture (15), incision of urethral stricture (6), relief of ureteropelvic junction obstruction (3), incision of bladder neck contracture (2), and ureteral tumor ablation (2). Procedures were considered successful, with no further intervention or alternative energy source required, in 81% of the cases. The laser demonstrated precise hemostatic cutting and warrants further investigation as a multipurpose urologic laser.

Holmium: YAG laser endoureterotomy for treatment of ureteral stricture

OBJECTIVES Endourologic techniques ranging from balloon dilation to endoincision with electrocautery, cold knife, and lasers have been increasingly used in recent years for the treatment of ureteral strictures. While the long-term results may not be as reliable or as durable as traditional reconstructive surgical techniques, they can be accomplished with much less morbidity. Recently, the holmium:yttrium-aluminum-garnet (YAG) laser, which possesses both cutting and coagulating properties, has been demonstrated to have many applications in urology. We report our experience with this laser in the endoscopic treatment of ureteral strictures. METHODS We reviewed the charts and follow-up history of 22 patients in whom the holmium:YAG laser was used to treat ureteral strictures from a variety of causes and including those in ureteroenteric anastomoses. Strictures were either approached in a retrograde fashion with a 6.9F ureteroscope or antegrade with flexible instruments in the cases involving ureteroenteric strictures. The only energy source employed was the laser, followed by balloon dilation. Indwelling stents were left in place for at least 4 weeks postoperatively and follow-up was obtained with radiographic imaging. RESULTS A minimum 9-month follow-up was available for 18 patients. There were 5 patients who had developed recurrent strictures and were therefore considered treatment failures. Each of these patients failed in less than 3 months and all had either lengthy or complex strictures noted at the time of surgery. One patient was lost to follow-up and three recent patients have follow-up of 3 to 6 months showing no evidence of recurrent stricture formation. Overall, 16 of 21 (76%) patients are clinically well with no evidence of stricture recurrence. CONCLUSIONS Endoureterotomy for ureteral stricture disease is a minimally invasive, less morbid, but ultimately less successful, alternative to open surgical reconstruction. Stricture length and etiology remain the most important determinants of success. The holmium:YAG laser, with its ability to precisely cut tissue and provide hemostasis and its multiuse potential and compatibility with small rigid and flexible endoscopic instruments, is an ideal tool for performing endoureterotomy.

Differences in Ureteroscopic Stone Treatment and Outcomes for Distal, Mid-, Proximal, or Multiple Ureteral Locations: The Clinical Research Office of the Endourological Society Ureteroscopy Global Study

BACKGROUND Ureteroscopy has traditionally been the preferred approach for treatment of distal and midureteral stones, with shock wave lithotripsy used for proximal ureteral stones. OBJECTIVE To describe the differences in the treatment and outcomes of ureteroscopic stones in different locations. DESIGN, SETTING, AND PARTICIPANTS Prospective data were collected by the Clinical Research Office of the Endourological Society on consecutive patients treated with ureteroscopy at centres around the world over a 1-yr period. INTERVENTION Ureteroscopy was performed according to study protocol and local clinical practice guidelines. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Stone location, treatment details, postoperative outcomes, and complications were recorded. Pearsons chi-square analysis and analysis of variance were used to compare outcomes among the different stone locations. RESULTS AND LIMITATIONS Between January 2010 and October 2012, 9681 patients received ureteroscopy treatment for stones located in the proximal ureter (n=2656), midureter (n=1980), distal ureter (n=4479), or multiple locations (n=440); location in 126 patients was not specified. Semirigid ureteroscopy was predominantly used for all stone locations. Laser and pneumatic lithotripsy were used in the majority of cases. Stone-free rates were 94.2% for distal ureter locations, 89.4% for midureter locations, 84.5% for proximal ureter locations, and 76.6% for multiple locations. For the proximal ureter, failure and retreatment rates were significantly higher for semirigid ureteroscopy than for flexible ureteroscopy. A low incidence of intraoperative complications was reported (3.8-7.7%). Postoperative complications occurred in 2.5-4.6% of patients and varied according to location, with the highest incidence reported for multiple stone locations. Limitations include short-term follow-up and a nonuniform treatment approach. CONCLUSIONS Ureteroscopy for ureteral stones resulted in good stone-free rates with low morbidity. PATIENT SUMMARY This study shows that patients who have ureteral stones can be treated successfully with ureteroscopy with a low rate of complications for the patient.

Percutaneous nephrolithotomy for staghorn calculi: a single center's experience over 15 years.

BACKGROUND AND PURPOSE Percutaneous nephrolithotomy (PCNL) for staghorn calculi is one of the more challenging endourologic procedures. Although excellent stone-free rates are universally reported in the literature, complication rates vary widely, especially related to the need for blood transfusion. The purpose of this study was to evaluate the outcomes of PCNL for patients with staghorn calculi in a large series of patients at a single, tertiary referral, endourologic stone center. PATIENTS AND METHODS Between July 1990 and December 2005, 1338 patients underwent PCNL for renal stone disease at our institution. Among this group, 509 procedures were performed for patients with a partial or complete staghorn calculus. Data analysis included procedure time, length of hospital stay, number of access tracts, transfusion rates, other early and late complications, and stone-free status. RESULTS Mean patient age was 53.8 years (range 4-84 yrs). The average procedure time was 104 minutes. Sixteen percent of the cases needed multiple access tracts (range 2-5), with the lower calix being the most commonly used in 64.1%, followed by the upper calix in 18.5% and the middle calix in 17.4%. Various intracorporeal lithotriptors were used, including ultrasound, pneumatic, electrohydraulic, and holmium:yttrium-aluminium-garnet laser. The transfusion rate among this group was 0.8%. There was no statistically significant difference in transfusion rates (0.7%-1.2% P = 0.24) or other major complications in patients who were treated with either a single tract or among those needing multiple tracts. Stone-free rates at hospital discharge and at 3 months follow-up were 78% and 91%, respectively. CONCLUSION PCNL is a safe and effective procedure in the management of staghorn calculi, with outcomes similar to those reported for percutaneous management of smaller volume nonstaghorn stones. Attention to accurate tract selection and placement as well as possession of the full array of endourologic equipment are essential to achieving an excellent outcome.

Percutaneous nephrolithotomy made easier: a practical guide, tips and tricks.

Percutaneous nephrolithotomy (PCNL) plays an integral role in managing large renal stones. Establishing percutaneous renal access is the most crucial step in the procedure and requires a thorough understanding of renal, retroperitoneal and thoracic anatomy to minimize the risk of complications. Moreover, access to fluoroscopy and the proper equipment are critical to ensuring complete stone removal. In this review we describe the technique of PCNL used in a high‐volume endourology centre, where the urologist is involved in all aspects of the procedure.