Treatment outcomes after endopyelotomy performed with or without simultaneous nephrolithotomy: 10-year experience

INTRODUCTION

The incidence of renal calculi associated with ureteropelvic junction obstruction (UPJO) has been reported to be as high as 20%. Although it has been suggested that simultaneous stone removal be performed with endopyelotomy (EP) for patients with UPJO, no crossing vessel, and renal calculi, there are no large series to date reporting in a rigorous fashion the success rate for resolution of the UPJO. This study intends to determine if stone extraction performed with EP increases failure rate.

MATERIALS AND METHODS

A retrospective review was performed for all patients who underwent EP by a single surgeon between August 1996 and November 2006. One hundred forty-six procedures for UPJO were done in 139 patients. Success rate was compared in 105 cases (72%) of isolated UPJO and 41 (28%) cases with UPJO and ipsilateral calculi. Determination of overall success required subjective improvement and objective data based on intravenous pyelogram, computed tomography, and/or nuclear scintigraphy.

RESULTS

Overall success rate was 71% in patients undergoing EP only and 90% in 41 patients who had simultaneous nephrolithotomy (p = 0.04). The odds ratio of failure after EP was 2.9 for severe/massive preoperative hydronephrosis. When considered alone and after adjusting for the severity of preoperative hydronephrosis and/or renal function, simultaneous nephrolithotomy did not increase the EP failure rate.

CONCLUSION

This study demonstrates that UPJO resolves at an equal rate after EP performed with or without ipsilateral renal calculi. Patients with UPJO and renal calculi should undergo stone extraction and EP in the same setting with the expectation of excellent results.

Pilot study of Alteplase (tissue plasminogen activator) for treatment of urinary clot retention in an in vitro model

INTRODUCTION

The management of urinary clot retention and hematuria involves manual irrigation with sterile water or normal saline via a Foley catheter followed by continuous bladder irrigation. Irrigation may become difficult because of the formation of dense blood clots. Tissue plasminogen activator (t-PA/Alteplase) may be a useful pharmacological agent to improve the efficacy of manual irrigation of large, dense clots. The goal of the current study was to compare t-PA to sterile water for clot irrigation in an in vitro model.

MATERIALS AND METHODS

In vitro models of clot retention were created using 500-cc urinary leg bags each filled with 80 cc of unpreserved whole blood from a healthy volunteer. Each model was incubated at 25 degrees C for 24 hours to allow clot formation. Four models each with 25 mL solution of t-PA at concentrations of 2, 1, 0.5, and 0.25 mg/mL were evaluated and compared to a control (25 mL sterile water). Models were instilled with solution (t-PA or control) and incubated for 30 minutes at 37 degrees C, and then irrigated with sterile water via 18F Foley by a blinded investigator. Three separate experiments were conducted, and statistical analysis was performed comparing various irrigation parameters.

RESULTS

Clot evacuation with 25 mL of t-PA at a concentration of 2 mg/mL (50 mg) was significantly easier (p = 0.05) and faster (p < 0.05) than the sterile water control. The mean time for clot evacuation in this model was 2.7 minutes for t-PA solution 2 mg/mL versus 7.3 minutes for the control (p < 0.05). Compared to the control, irrigation with t-PA solution 2 mg/mL also required less irrigant (180 mL vs. 500 mL) (p < 0.05) for complete evacuation. There was a similar trend in efficacy for the lower doses of t-PA, but this was not statistically significant.

CONCLUSION

In this in vitro study, a single 25 mL instillation of t-PA solution 2 mg/mL is significantly better than sterile water alone for clot evacuation. In vivo animal studies are pending.

Evaluation of bladder insufflants for transurethral cryoablation of the bladder

OBJECTIVES

To compare helium and carbon dioxide gas insufflation for the creation of pneumocystis during bladder cryoablation in an effort to optimize the technique.

METHODS

Nine pigs were divided into 3 groups. The pigs in groups 1, 2, and 3 underwent bladder cryoablation in a normal saline, carbon dioxide gas, and helium gas environment, respectively. Each group underwent 2 freeze-thaw cycles of the bladder dome. The bladder pressure measurements were recorded every 5 seconds throughout the cryoablation procedure. Bladder integrity was evaluated with both cystoscopic and laparoscopic visualization. All pigs were killed at the completion of the procedure, and the bladders were harvested for histopathologic evaluation.

RESULTS

All 9 pigs successfully underwent bladder wall cryoablation. Bladder integrity was maintained in all 6 pigs in groups 1 and 3. In group 2, 2 bladder ruptures were documented. All group 2 pigs had a significantly increased bladder pressure during the 2 thaw cycles of the cryoablation procedure, with the peak pressure >70-100 mm Hg before venting of the excess carbon dioxide gas. No intervention was required to stabilize the bladder pressure in groups 1 and 3. The average change in pressure per 5-second interval during both thaw cycles for groups 1, 2, and 3 was 0.16, 6.96, and 0.42 mm Hg/s, respectively (P = .0003). Group 3 showed mild hemorrhage on histologic examination.

CONCLUSIONS

The creation of pneumocystis with helium gas reduces sublimation and eliminates the problems of rapidly fluctuating bladder pressures and decreased visibility previously noted with carbon dioxide gas during bladder cryoablation.

Nomenclature of natural orifice translumenal endoscopic surgery (NOTES) and laparoendoscopic single-site surgery (LESS) procedures in urology

INTRODUCTION

The twenty first century has witnessed some amazing advancements in surgery. In urology minimally invasive surgery has become the standard treatment for many disease processes and procedures. One of the newest innovations into this field has been the development of Natural Orifice Translumenal Endoscopic Surgery (NOTES) and Laparoendoscopic Single-site Surgery (LESS). While the practice and application of these new techniques are in their infancy, there has been a great deal of confusion regarding the nomenclature and terminology associated with these procedures. The aim of this publication is to attempt to define the many issues associated with the standardization of terminology for these procedures in order to promote effective scientific progress and communication.

MATERIALS AND METHODS

A literature search using Medline and pubmed focusing on all terminology to describe NOTES and LESS from 1990 to 2008 was done. In addition, various acronyms were searched using four separate online acronym databases. The information was recorded by number of citations and by the number of citations specific to the urologic literature. Based on common usage, definitions and criteria were developed to describe these procedures for current scientific publication. These terms were then collectively reviewed and agreed upon by the Urologic NOTES Working Group as a platform for consensus to begin the arduous process of standardization.

RESULTS

There is wide variation in the terminology and use of acronyms for natural orifice translumenal endoscopic surgery and laparo-endoscopic single-site surgery. The keyword literature search uncovered 8710 citations from MEDLINE and pubmed, with 363 citations specific to urology. There was significant overlap in the search of different terms. The search of established abbreviation and acronym databases revealed many citations, but relatively few specific to urology.

CONCLUSION

Standardization of the nomenclature applied to natural orifice transluminal endoscopic surgery (NOTES) and laparo-endoscopic single-site surgery (LESS) is essential as the body of literature continues to grow in order to allow clear and precise scientific communication. As the techniques continue to evolve, we propose that NOTES and LESS be designated as the common terms to define these new procedures in urology.

Urologic laser types and instrumentation

Though the primary role of lasers in urology has always been in the treatment of urolithiasis, there are several other indications for their use. There are many different types of lasers currently available, each with unique properties conducive to treating certain disorders. As such, it is critical that today's urologist understands each laser's characteristics in order to optimize patient selection and treatment. The lasers which are primarily used in urologic applications include the carbon dioxide (CO2) laser; the Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG); the Potassium Titanyl Phosphate (KTP) laser and the Holmium:YAG (Ho:YAG) laser. This review focuses on the unique characteristics of each of these lasers as well as the instrumentation needed utilize and deploy these tools in the urinary tract.

Pilot study evaluating ureteric physiological changes with a novel 'ribbon stent' design using electromyographic and giant magnetoresistive sensors

OBJECTIVE

To test a novel 'ribbon stent' (RS) design using an extraluminal bipolar electromyographic (EMG) and giant magnetoresistive (GMR) sensor system to characterize ureteric responses.

MATERIALS AND METHODS

In all, 11 female domestic pigs were divided into three groups to evaluate ureteric physiology: group 1 (two pigs) with an unstented ureter, group 2 (three) with a standard 6 F ureteric stent, and group 3 (six) with the RS. For all groups EMG/GMR evaluation was performed at baseline, immediately after stenting, and at 3 and 7 days after stenting. All pigs underwent standardized retrograde ureteropyelogram evaluation at these time points, and after the final evaluation the pigs were killed and the urinary tract was harvested for histopathological evaluation.

RESULTS

One stent in group 3 could not be deployed due to a problem with ureteric access. For groups 1, 2 and 3 the ureteric peristaltic activity was 109, 63, 72 events/h at baseline (P = 0.49); 61, 70, and 66 events/h immediately after stenting (P = 0.97); 66, 0, 8 events/h at 3 days after stenting (P = 0.002); and 61, 12, 0 events/h at 7 days after stenting, respectively (P = 0.049).

CONCLUSION

The RS was deployed easily and safely in the porcine model using a standard technique. As with a standard stent, there was significant ureteric dilation and decrease in peristalsis with the RS.

The effect of intraluminal content on the bursting strength of vessels ligated with the harmonic ACE and LigaSure V

PURPOSE

Energy-based surgical devices (ESDs) are critical for maintaining hemostasis during laparoscopy; however, there are no studies that have evaluated the function of ESDs under different physiologic conditions. We evaluated the effect of intraluminal vessel content on bursting pressure (BP) after ligation with two ESDs: the Harmonic ACE and the LigaSure V.

MATERIALS AND METHODS

Bursting trials were performed on the vasculature of 24 pigs. Blood vessels were distended with blood of different hematocrit concentrations or an albumin solution of varying protein content. The vessel size and BP of each vessel was recorded after ligation with each ESD.

RESULTS

In arteries 0 to 3 mm and veins 0 to 3 mm in size ligated with the Harmonic ACE or the LigaSure V, there were significantly elevated vessel BPs with supraphysiologic intraluminal hematocrits. In arteries and veins ligated with the Harmonic ACE, increasing albumin concentrations also led to increasing BPs, though these maximal BPs were lower than those obtained with supraphysiologic hematocrit levels. Increasing albumin concentrations did not increase the BP of the LigaSure V. Within the ranges tested, there was no decrease in vessel BP associated with anemia.

CONCLUSION

In small vessels, a supraphysiologic hematocrit increased the BP of both arteries and veins when using the Harmonic ACE or the LigaSure V. With the devices tested, anemia did not seem to affect BP. While factors such as intraluminal protein concentration may play a role with ultrasonic energy devices, the mechanism of the increased BP remains unclear. Better understanding of ESDs will help in the design of future devices.

High definition in minimally invasive surgery: a review of methods for recording, editing, and distributing video

The use of high-definition cameras and monitors during minimally invasive procedures can provide the surgeon and operating team with more than twice the resolution of standard definition systems. Although this dramatic improvement in visualization offers numerous advantages, the adoption of high definition cameras in the operating room can be challenging because new recording equipment must be purchased, and several new technologies are required to edit and distribute video. The purpose of this review article is to provide an overview of the popular methods for recording, editing, and distributing high-definition video. This article discusses the essential technical concepts of high-definition video, reviews the different kinds of equipment and methods most often used for recording, and describes several options for video distribution.

Ultrasonic and nonultrasonic instrumentation: a systematic review and meta-analysis

OBJECTIVE

To compare the efficacy and safety of ultrasonic surgical instrumentation with nonultrasonic traditional surgical techniques in various types of surgery.

DATA SOURCES

Electronic searches of MEDLINE, Current Contents, and the Cochrane Library were performed for the period of 1990 to June 1, 2005, using relevant search terms. A manual check of all references in accepted studies was also performed.

STUDY SELECTION

Only comparative studies (including randomized and nonrandomized control trials) of ultrasonic surgical instrumentation with nonultrasonic instrumentation were accepted. Procedures of interest included the following: colorectal surgery, gynecologic surgery, head and neck surgery, solid organ surgery, vessel harvesting, cholecystectomy, hemorrhoidectomy, mastectomy, and Nissen fundoplication.

DATA EXTRACTION

Two investigators reviewed each study: the first investigator extracted all relevant data, and consensus of each extraction was performed by a second investigator to verify the data. Data were then entered into a database and quality checked for accuracy.

DATA SYNTHESIS

Fifty-one primary studies that examined 4902 patients were included in this systematic review, of which 24 were randomized trials and 27 were nonrandomized studies. Comparative meta-analyses for blood loss, surgery time, and hospital length of stay were performed using a random-effects model and stratified by surgery type. Heterogeneity was tested using Q statistics. Statistical significance was defined as P < .05.

CONCLUSION

Meta-analysis of outcomes comparing ultrasonic with conventional nonultrasonic surgical instrumentation demonstrates significant improvement of several perioperative outcomes in procedure-specific settings when ultrasonic instrumentation is used.

Prospective randomized comparison of a combined ultrasonic and pneumatic lithotrite with a standard ultrasonic lithotrite for percutaneous nephrolithotomy

PURPOSE

To compare the efficiency and cost effectiveness of a combined pneumatic and ultrasonic lithotrite (Lithoclast Ultra) and a standard ultrasonic lithotrite, (LUS-1) during percutaneous nephrolithotomy.

MATERIALS AND METHODS

In a prospective randomized trial, 30 patients undergoing percutaneous nephrolithotomy (PCNL) were randomized to PCNL with either the combined pneumatic and ultrasonic lithotrite (PUL) or a standard ultrasonic lithotrite (SUL). Patient demographics, stone composition, location, pre- and post-operative stone burden, fragmentation rates, and device failures were compared.

RESULTS

There were 13 patients in the PUL group and 17 patients in the SUL group. Stone burden and location were equal. Overall, 64% of the PUL group had hard stones (defined as stones that were either pure or a mixture of cystine [3], calcium oxalate monohydrate [CaOxMono; 2], and calcium phosphate [CaPO4; 2]), and four had soft stones (3 struvite and 1 uric acid [UA]). In the SUL group, there were eight hard stones (5 CaOxMono and 3 CaPO4), and six soft stones (4 calcium oxalate dihydrate [CaOxDi] and 2 UA) (P = 0.51). Stone composition data were unavailable for five patients. Fragmentation time for the PAL was 37 minutes versus 31.5 minutes for the SUL (P = 0.22). Stone retrieval and mean operative times were similar for both groups. There were a total of three (23.1%) device-related problems in the PUL group, and eight (47%) in the SUL group. There was one (7.7%) device malfunction in the PUL group due to probe fracture. There were two (11.7%) device failures in the SUL group; one failure required the device to be reset every 30 minutes, and the second was an electrical failure. Suction tubing obstruction occurred twice (15.3%) in the PUL group and 35.3% in the SU group (P = 0.35). The stone-free rates for the PUL and SUL were 46% and 66.7%, respectively (P = 0.26).

CONCLUSION

Although the PUL was more costly, stone ablation and clearance rates were similar for both the combined pneumatic and ultrasonic device and the standard ultrasonic device. When stratified with respect to stone composition, the PUL was more efficient for harder stones, and the SUL was more efficient for softer stones.