Comparison of absorbed irrigation fluid volumes during retrograde intrarenal surgery and percutaneous nephrolithotomy for the treatment of kidney stones larger than 2 cm

Fluid absorption during flexible ureteroscopy with intelligent control of renal pelvic pressure: a randomized controlled trial

PURPOSE

To investigate fluid absorption and its influencing factors during flexible ureteroscopy with intelligent control of renal pelvic pressure (RPP).

METHODS

A total of 80 patients with upper urinary tract calculi underwent flexible ureteroscopy with intelligent control of RPP by pressure-measuring ureteral access sheath and were randomly divided into four groups. The RPP of Groups A, B, and C were set at - 5, 0 and 5 mmHg, respectively. Conventional flexible ureteroscopy with uncontrolled pressure served as control Group D. The perfusion flow rate was set at 100 ml/min in the four groups, with 20 patients in each group. The fluid absorption was measured by 1% ethanol every 10 min. Operation time, stone-free rate, and complications were recorded.

RESULT

Seventy-three patients were finally included in the RCT. The general and preoperative data of the patients were comparable between the groups. The fluid absorption of Groups A, B, and C was significantly less than that of Group D (P < 0.01). Fluid absorption and operation time were positively correlated, and the correlation coefficients R were 0.864, 0.896, 0.918, and 0.947, respectively (P < 0.01). The fluid absorption of patients with vomiting, fever and ureteral injury was greater than that of patients without complications in the four groups (P < 0.01). In different groups, fluid absorption was greater in patients with ureteral injury Post-Ureteroscopic Lesion Scale (PULS) 1-3 than in noninjured patients (P < 0.01).

CONCLUSION

Flexible ureteroscopy with intelligent control of RPP effectively reduces the absorption of perfusion fluid. Operation time and ureteral injury are also key factors affecting perfusion fluid absorption.

REGISTRATION NUMBER AND DATE

NCT05201599; August 11, 2021.

PCNL vs. two staged RIRS for kidney stones greater than 20 mm: systematic review, meta-analysis, and trial sequential analysis

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) is considered the gold standard treatment for kidney stones greater than 20 mm. However, retrograde intrarenal surgery (RIRS) may achieve the same stone-free rate with repeated procedures, and potentially fewer complications. This study aimed to compare the efficacy and safety of PCNL and two-staged RIRS.

EVIDENCE ACQUISITION

We conducted a systematic search in PubMed, Embase, Scopus, Cochrane, and Web of Science for studies comparing PCNL and RIRS for kidney stones greater than 20mm. The primary outcome is stone-free rate (SFR) of PCNL and RIRS (repeated once if needed). Secondary outcomes were SFR of PCNL versus RIRS (single procedure), operative time, hospital stay, need for auxiliary procedures, and complications. We performed a subgroup analysis for randomized trials, non-randomized trials, and patients with solitary kidney. We performed a trial sequential analysis for the main outcome.

EVIDENCE SYNTHESIS

We included 31 articles, with 1987 patients in the PCNL and 1724 patients in RIRS. We confirmed the traditional result that after a single procedure PCNL has a higher SFR. We also found that comparing the SFR of PCNL and RIRS, repeated up to two times if needed, no difference in SFR was observed. Surprisingly, only 26% (CI95 23%-28%) of the patients required a second RIRS. In the trial sequential analysis, the last point of the z-curve was within futility borders. We observed that PCNL has a higher incidence of complications (RR=1.51; CI95 1.24, 1.83; P<0.0001; I2=28%), specifically CD2 (RR=1.82; CI95 1.30, 2.54; P=0.0004; I2=26%) and longer hospital stay (MD 2.57; 2.18, 2.96; P<0.00001; I2-98%). No difference was observed regarding operative time.

CONCLUSIONS

RIRS repeated up to two times is equivalent to PCNL in terms of the SFR and may have the same safety.

Evaluation of a novel circulation system for ureteroscopic laser lithotripsy in vitro

PURPOSE

To evaluate the cooling effect and other advantages of a novel circulation system for ureteroscopic holmium laser lithotripsy (URSL) in a standardized in vitro model.

MATERIALS AND METHODS

The novel circulation system was assembled by connecting a 4Fr ureteral catheter and a filter. Trails were divided into a new URSL group and a conventional URSL group. First, different power settings (18-30 W) of the holmium laser and irrigation flow rates (20-50 mL/min) were used to evaluate the thermal effect on the lithotripsy site of all groups. Then, renal pelvic temperature and pressure were assessed during URSL at a power of 1.5 J/20 Hz and irrigation flow rates of (20-50 mL/min). Finally, the whole process of lithotripsy was performed at 1.5 J/20 Hz (operator duty cycle ODC: 50%) with an irrigation flow rate of 30 mL/min. The time required for lithotripsy, visual field clarity, and stone migration were observed.

RESULTS

Temperature of the lithotripsy point was significantly lower in the new URSL group than in the conventional group (P < 0.05) with irrigation rates (20, 30 mL/min). The renal pelvic pressure of the new group was significantly lower than that of the conventional group in which intrarenal hypertension developed at an irrigation rate of 50 ml/min. The new group had better visual clarity and lesser stone upward migration when lithotripsy was performed at 1.5 J/20 Hz and 30 ml/min.

CONCLUSION

The novel circulation system is more effective in reducing the thermal effects of URSL, pelvic pressure, stone upward migration, and improving the visual clarity of the operative field.

The effect and safety assessment of monitoring ethanol concentration in exhaled breath combined with intelligent control of renal pelvic pressure on the absorption of perfusion fluid during flexible ureteroscopic lithotripsy

PURPOSE

Previously, we designed a ureteral access sheath with the capability of renal pelvic pressure (RPP) measurement and a medical perfusion and aspiration platform, allowing for the intelligent control of RPP. However, the effect of different RPP levels on perfusion fluid absorption remains unclear. This randomized controlled trial aimed to investigate the effects of exhaled ethanol concentration monitoring and intelligent pressure control on perfusion fluid absorption during flexible ureteroscopic lithotripsy.

METHODS

Eighty patients scheduled for flexible ureteroscopic lithotripsy were randomly divided into four groups. In groups A, B, and C, the RPPs were set at 0, - 5, and - 10 mmHg, respectively. Group D was regarded as the controls with unfixed RPP. Isotonic saline containing 1% ethanol was used as the irrigation fluid, with an average irrigation flow rate of 100 mL/min. The primary outcome of this study was the absorption of perfusion fluid that was calculated based on the exhaled ethanol concentration. The secondary outcomes included duration of operation and amounts of perfusion fluid used. Postoperative complications, pre- and postoperative renal function, infection markers, and blood gas analysis were also recorded for safety assessment.

RESULTS

In all, 76 patients were involved in this study, whose demographic characteristics and preoperative conditions were comparable among groups. Under the same perfusion flow rate, the groups with fixed RPP exhibited reduced absorption of perfusion fluid, duration of operation, and perfusion volume. In particular, the lowest values were observed in group C (RPP =  - 10 mmHg). In contrast to the unfixed RPP group, no considerable difference were observed in levels of BUN, Scr, WBC, CRP, and blood gas values among the fixed RPP groups. Moreover, postoperative complications showed no significant difference among groups.

CONCLUSION

In flexible ureteroscopic lithotripsy, the groups with fixed RPP had less absorption of perfusion fluid and perfusion volume, shorter duration of surgery, and higher safety than the unfixed group.

International Alliance of Urolithiasis guideline on retrograde intrarenal surgery

OBJECTIVES

To set out the second in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis that concerns retrograde intrarenal surgery (RIRS), with the aim of providing a clinical framework for urologists performing RIRS.

MATERIALS AND METHODS

After a comprehensive search of RIRS-related literature published between 1 January 1964 and 1 October 2021 from the PubMed database, systematic review and assessment were performed to inform a series of recommendations, which were graded using modified GRADE methodology. Additionally, quality of evidence was classified using a modification of the Oxford Centre for Evidence-Based Medicine Levels of Evidence system. Finally, related comments were provided.

RESULTS

A total of 36 recommendations were developed and graded that covered the following topics: indications and contraindications; preoperative imaging; preoperative ureteric stenting; preoperative medications; peri-operative antibiotics; management of antithrombotic therapy; anaesthesia; patient positioning; equipment; lithotripsy; exit strategy; and complications.

CONCLUSION

The series of recommendations regarding RIRS, along with the related commentary and supporting documentation, offered here should help provide safe and effective performance of RIRS.

Evaluation of fluid absorption during flexible ureteroscopy in an in vivo porcine model

OBJECTIVE

To evaluate the relationship between renal pelvis pressure and fluid absorption during ureteroscopy (URS) in a live porcine model.

MATERIALS AND METHODS

Flexible URS (fURS) was performed in anaesthetised female Yorkshire pigs. Prior to performing fURS, a 0.3556-mm (0.014″) pressure-sensing guidewire (Comet™, Boston Scientific) was placed to monitor renal pelvis pressure. A simulated fURS procedure was then performed for 1 h. Infusion of irrigation fluid (5% ethanol in saline) at target renal pelvis pressures (37-150 mmHg) was maintained for 1 h using a pressure bag and real-time feedback from the pressure-sensing guidewire. Venous blood was sampled every 10 min. The volume of irrigation fluid absorbed was estimated with established equations.

RESULTS

A URS procedure was performed in vivo in 18 porcine kidneys and the volume of irrigation fluid absorbed during the 1 h URS was calculated. The mean (SD) volume of irrigation fluid absorbed after 1 h of simulated URS was 7.6 (5.7), 10.8 (7.1), 26.0 (15.8), and 56.8 (22.3) mL at renal pelvis pressures of 37, 55, 75, and 150 mmHg, respectively. Compared with URS with renal pelvis pressure of 37 mmHg, the volume of fluid absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (P = 0.026 and P = 0.047, respectively). In addition, compared with URS with renal pelvis pressure of 37 mmHg, the rate of absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (both P < 0.001).

CONCLUSION

In this study of an in vivo porcine model of URS, increasing renal pelvis pressures during URS were associated with increases in irrigation fluid absorption and increases in the rate of fluid absorption.

What is the impact of pulse modulation technology, laser settings and intraoperative irrigation conditions on the irrigation fluid temperature during flexible ureteroscopy? An in vivo experiment using artificial stones

PURPOSE

To investigate the effect of different combinations of laser power settings and irrigation conditions using the pulse modulation technology of Quanta™ on irrigation fluid temperature (IFT) during FURS (flexible ureteroscopy) on an in-vivo porcine model with artificial stones.

MATERIALS AND METHODS

A female pig was used. Following the insertion of artificial stones (Begostone™, BEGO USA, Lincoln, RI), a K-type thermocouple was fixed to the created percutaneous access tract. Real-time recordings of IFT during FURS were performed without UAS (ureteral access sheath), with 10/12 UAS, 12/14 UAS and 14/16 UAS. Stone fragmentation was achieved using Quanta Litho Cyber Ho 150 W™ (Samarate, Italy). The IFT was recorded for 30 s, during laser activation, with power settings of 20, 40, 60, 75 and 100 W under both manual pump and gravity irrigation.

RESULTS

The IFT rise above 54 °C was recorded above a power of 40 W when gravity irrigation was used. The use of UAS prolonged the time for IFT to reach high values, although high power settings increase IFT within seconds from the laser activation. Under pump irrigation, only the 100 W power setting without the use of UAS resulted in dangerous IFT after approximately 10 s.

CONCLUSION

The high-power Ho:YAG laser can cause a damaging thermal effect to the kidney exceeding the threshold of 54 °C, under gravity irrigation. Lower power settings (up to 40 W) can be used with safety. According to our experiment, when using high power settings, the use of UAS and manual pump irrigation, is the safest combination regarding renal thermal damage.

MOSES™ pulse modulation technology versus conventional pulse delivery technology: the effect on irrigation fluid temperature during flexible ureteroscopy

To compare the effect of MOSES™ modulation technology to conventional pulse delivery technology on the irrigation fluid temperature (IFT) under different irrigation conditions during flexible ureteroscopy (FURS) in a live-anesthetized porcine model. For this experiment was used one female pig. A percutaneous access was obtained and a 30Fr sheath was placed inside the upper calyceal system. A thermocouple was inserted through the sheath to the upper calyx to record the effect on IFT during FURS. A Lumenis 120H Ho:YAG laser was used and the IFT was recorded during laser activation for 30 s at a laser power of 20 W, 40 W and 60 W under gravity and manual pump irrigation using MOSES™ and conventional pulse delivery technology. In the highest power settings the maximum IFT was achieved in 18 s under gravity irrigation (66.4 °C). It seems that there is no significant difference on IFT between MOSES and conventional mode on the IFT under different irrigation conditions during FURS at 20 W, 40 W and 60 W power settings. Furthermore, our results indicate that under manual pumping even high-power settings (40 W, 60 W) can be performed with safety. In the in vivo model, the MOSES™ pulse delivery technology does not have a significant difference in the maximal IFT in comparison to conventional pulse delivery technology during FURS in the same power settings. Manual pumping should be used to keep the IFT within safe limits.

Perirenal Extravasation After Retrograde Intrarenal Surgery for Renal Stones: A Prospective Study

Background

The incidence and consequences of the perirenal extravasation of the irrigation fluid during retrograde intrarenal surgery (RIRS) are not fully elucidated. The objective of this study was to assess the incidence, risk factors, and complications of perirenal extravasation of irrigation fluid during RIRS.

Methods

This prospective observational study was conducted in the Department of Urology, Bir Hospital, Kathmandu, Nepal, from January 2020 to March 2021. Patients undergoing RIRS for renal stones less than 2 cm in diameter were included in the study. Irrigation during the procedure was performed using isotonic normal saline under gravity at 50 cm from the symphysis pubis of patients with intermittent manual compression if required. Lithotripsy was performed with 120-Watt Ho:YAG laser using 200-micron laser fiber. Retrograde pyelogram was performed after the completion of lithotripsy to document the presence or absence of extravasation on fluoroscopic images. A double-J stent was placed at the end in all patients. Patients were observed for systemic inflammatory response syndrome (SIRS) features. Postoperative abdominal ultrasonography was performed on the first postoperative day to assess the perirenal collection together with complete blood count. The visual analogue scale (VAS) was used to assess pain in postoperative period. The preoperative patient’s and stone characteristics, hydronephrosis, intraoperative characteristics, and postoperative findings were analyzed.

Results

A total of 71 patients who underwent RIRS during the study period were analyzed. The mean (SD) stone size was 13.19 (3.12) mm. Intraoperative perirenal extravasation of contrast was noted in eight (11.26%) patients; however, no patient had ipsilateral perirenal collection on ultrasonography obtained on the first postoperative day. No significant differences were observed among patients with or without perirenal extravasation in terms of mean stone size, laser settings, operative duration, and lasing duration. Use of ureteral access sheath (UAS) was associated with lower incidence of extravasation; however, it was not significant. SIRS was documented in eight patients overall, with none of the patients with extravasation having features of SIRS. Patients with extravasation experienced more postoperative flank pain (p<0.05).

Conclusion

Perirenal extravasation was common during RIRS and was associated with higher postoperative pain scores. Stone size, use of UAS, laser settings, operative duration, and lasing duration were not associated with an increased risk of extravasation. Extravasation was not associated with increased postoperative complications.

Chilled irrigation for control of temperature elevation during ureteroscopic laser lithotripsy: in vivo porcine model

INTRODUCTION

Multiple studies have shown significant heating of fluid within the urinary collecting system with high-power laser settings. Elevated fluid temperatures may cause thermal injury and tissue damage unless appropriately mitigated. A previous in vitro study demonstrated that chilled (4 °C) irrigation slowed temperature rise, decreased plateau temperature, and lowered thermal dose during laser activation with high-power settings. We sought to evaluate the thermal effects of chilled, room temperature, and warmed irrigation during ureteroscopy with laser activation in an in vivo porcine model.

MATERIALS AND METHODS

Seven female Yorkshire cross pigs (45-55 kg) were anesthetized and positioned supine. Retrograde ureteroscopy was performed with a thermocouple affixed 5 mm from the distal end of the ureteroscope. In two pigs a holmium:YAG laser was activated for 60 seconds at irrigation rates of 8 ml/min, 12 ml/min, and 15 ml/min with chilled, room temperature, or warmed irrigation. In five pigs core body temperature was recorded for one hour with or without continuous chilled irrigation at 15 ml/min.

RESULTS

At irrigation rates ≥ 12 ml/min, temperature curves appeared uniformly offset, warmed > room temperature > chilled irrigation. The threshold of thermal tissue injury was reached during laser activation for all irrigation temperatures at 8 ml/min. The threshold was not reached with chilled irrigation at 12 ml/min or 15 ml/min, or with room temperature irrigation at 15 ml/min. The threshold was exceeded at all irrigation rates with warmed irrigation. There was no significant change in core body temperature after delivering chilled irrigation at 15 ml/min compared with no irrigation for 60 minutes.

CONCLUSION

Irrigation with chilled saline solution during ureteroscopic laser lithotripsy slows temperature rise, lowers peak temperature, and lengthens the time to thermal injury compared to irrigation with room temperature or warmed saline solutions. Core body temperature was not significantly impacted by chilled irrigation.

Novel Irrigation Protocol for Renal Pelvis Sterilization During Percutaneous Nephrolithotomy: A Pilot Study

While percutaneous nephrolithotomy (PCNL) remains the treatment modality of choice for kidney stones larger than 2 cm, infectious complications are most common, ranging from 5% to 32%. We present here a novel technique for potentially improving collecting system sterility during PCNL and initial postoperative outcomes. Retrospective chart analysis data of our irrigation protocol were collected from our first 56 patients between February and July 2019. Traditional prone PCNL was performed in a standard manner using fluoroscopic guidance. Using a ureteral catheter that was placed cystoscopically, a renal pelvis urine culture was taken and subsequently 10 mL of betadine solution was instilled into the collecting system. Gentamicin in normal saline (80 mg/3 L) was utilized as the irrigant fluid for the first 6 L of irrigation. From this cohort, 57% patients were women and mean age was 60 ± 14 years. About 23% of patients were diabetic and 55% were hypertensive. Seventy percent of patients had stone burden >2 cm and no patients had stone burden <1 cm. Fifteen patients had positive urine cultures treated preoperatively, while four patients had contaminated cultures. All patients were treated with our antibiotic irrigation and betadine protocol regardless of preoperative cultures or antibiotics. Mean baseline creatinine level was 0.95 ± 0.41, with a mean change of 0.18 at postoperative day 1. Of the 15 (26%) of 56 patients with a systemic inflammatory response syndrome response (two of following four criteria: white blood cells <4 or >12; heart rate >90; hypothermia <96.8°F or hyperthermia >100.4°F; and respiratory rate >20), only six patients (11%) were febrile and two patients had positive blood cultures (3%). There were no adverse reactions to the betadine or antibiotic irrigation. We present here our initial experience of a new technique for renal pelvis sterilization and its safety and feasibility using intrarenal instillation of betadine and antibiotic irrigation. No Clinical Trial Registration number applicable.

Effects of irrigation fluid temperature during flexible ureteroscopic holmium laser lithotripsy on postoperative fever and shivering: a randomized controlled trial

Background

Flexible ureteroscopic holmium laser lithotripsy is used to treat urinary tract calculi, but postoperative complications include shivering, fever and infection. To investigate the effects of irrigation fluid temperature on postoperative complications.

Methods

This randomized controlled trial included 120 consecutive patients undergoing flexible ureteroscopic holmium laser lithotripsy at the Urology Department, Suining Central Hospital, Sichuan, China between January 2017 and July 2019. Patients were randomized 1:1:1 into three groups (17 °C, 27 °C or 37 °C). Primary outcome was fever incidence (body temperature > 37.5 °C) within 48 h after surgery. Secondary outcomes included shivering incidence during recovery from anesthesia, white blood cell count (WBC), serum procalcitonin (PCT) and incidence of suspected infection (temperature > 38.5 °C and PCT > 0.5 µg/L).

Results

There were 108 patients, (17 °C group, n = 36; 27 °C group, n = 35; 37 °C group, n = 37), received flexible ureteroscopic holmium laser lithotripsy and analyzed. Age, gender distribution, body mass index, ASA grade, stone burden, preoperative creatinine, preoperative core temperature and irrigation fluid volume did not differ significantly between groups. 17 °C, 27 °C and 37 °C groups exhibited significant differences in the incidences of postoperative fever (38.9% vs. 17.1% vs. 13.5%) and shivering (22.2% vs. 5.7% vs. 2.7%) (p < 0.05 for all pairwise comparisons). There was no significant difference of WBC, PCT and incidence of suspected infection in 37 °C or 27 °C group compared with 17 °C group. One case each of flash pulmonary edema and bleeding occurred in 37 °C group.

Conclusion

Warming the irrigation fluid can reduce the incidence of postoperative fever and shivering, but further studies are needed to determine the optimal temperature.

Trial registration The trial was registered at the Chinese Clinical Trials Registry and allocated as ChiCTR2000031683. The trial was registered on 07/04/2020 and this was a retrospective registration.

"VirtualBasket" ureteroscopic holmium laser lithotripsy: intraoperative and early postoperative outcomes

BACKGROUND

The "VirtualBasket" technology is the result of pulse modulation during holmium laser emission: the laser emits part of the energy to create an initial bubble, and a second pulse is emitted when the vapor bubble is at its maximum expansion, so that it can pass through the previously created vapor channel. The aim of this study is to outline the outcomes of the "VirtualBasket" technology in ureteral and renal stones.

METHODS

160 Patients were randomly assigned to holmium laser lithotripsy with or without the "VirtualBasket" technology in ureteric or renal cases (40 per 4 groups). All procedures were performed by four experienced urologists. The Quanta System Cyber Ho 100W laser generator with 365 μm fibers was used for all of the ureteral cases, whereas, 272 μm fibers were used for all of the cases in the renal pelvis. Demographic data, stone parameters, perioperative complications and success rates were compared. A statistical analysis was carried out to assess patients data and outcomes. All of the reported p-values were obtained with the two-sided exact method at the conventional 5% significance level. The degree of stone retropulsion was graded on a Likert scale from zero (no retropulsion) to 3 (maximum retropulsion).

RESULTS

All groups were comparable in terms of age, and pre-operative stone size (ureter stone size: 1.2 vs. 1.1 cm; renal pelvis stone size: 1.55 vs. 1.62 cm). Compared to the regular mode, the "VirtualBasket" technology was associated with significantly lower fragmentation time (mean time for ureteral stones: 20.4 vs. 16.1 minutes, p<0.05; mean time for renal stones: 28.7 vs. 19.8 minutes, p<0.05) and total procedural time (mean time for ureteral stones 49 vs. 35.7 minutes; mean time for renal stones 67.1 vs. 52.4 minutes). There were no significant differences in terms of energy delivered to the stones, intraoperative complications and success rate at 1 month. The "VirtualBasket" technology was associated with significantly lower retropulsion.

CONCLUSIONS

The "VirtualBasket" technology is associated with significantly lower fragmentation and procedural times. The reduced fragmentation time is a result of the significantly lower retropulsion of the stones during laser lithotripsy, which improves stone fragmentation efficiency.

Visual clarity of irrigants used during flexible ureterorenoscopy: an in vitro comparison

Introduction

Saline solution is the standard irrigant used during ureteroscopy. However, there is an opinion that water has better visual clarity. We aimed to compare the visual clarities of saline, water, and 5% mannitol as an irrigant during ureteroscopy.

Material and methods

An in vitro model consisting of an irrigant-filled container and a fiberoptic flexible ureteroscope was designed. A 1951 USAF Resolution Test Target and color checker within irrigants were used to evaluate the clarity of vision. The visual clarity was compared for 0.9% saline, distilled water and 5% mannitol solution with screen resolution and color contrast. The tests were repeated after adding human blood (2/400 ml) and contrast (20/400 ml) to the irrigants.

Results

There was no significant difference in resolution values of three plain irrigants at a distance of 10 mm. However, when blood was added to the irrigants, a better resolution of 29.3% for water and 20.6% for mannitol was achieved compared to saline. At 20 mm of distance, it was observed that the difference was more pronounced in irrigants with blood. Water and mannitol had 55.6% and 37.1% better resolution than saline, respectively. In the color reproduction test, there was no significant difference in the three plain irrigants, however, water had better color contrast compared to the others.

Conclusions

Water and 5% mannitol did not provide a significant image clarity advantage compared to saline. However, when blood was added to the irrigants, water provided significantly better visual clarity compared to saline. The use of water during various clinical scenarios in flexible ureteroscopy should be further investigated.

Risk factors for the fever after percutaneous nephrolithotomy: a retrospective analysis

Background

It’s very common to see the onset of fever after percutaneous nephrolithotomy (PCNL), it’s necessary to analyze the risk factors for the fever following PCNL, and to provide evidence for infection prevention after PCNL.

Methods

A total of 546 adult PCNL patients were included as study subjects and retrospective studies were performed. We collected clinical data of patients using a prospectively designed database. Univariate and multivariate logistic regression analyses were performed to identify the potential risk factors for the fever after PCNL.

Results

Of the included 546 PCNL patients, there were 82 fever patients and 464 no-fever patients following PCNL. Escherichia coli and Proteus mirabilis are the two most common infectious bacteria. Preoperative urinary tract infection (OR =4.38, 95% CI: 1.15–9.53), multiple access (OR =5.31, 95% CI: 1.23–10.75), diabetes (OR =4.97, 95% CI: 1.37–9.86), length of operation ≥60 min (OR =5.67, 95% CI: 2.24–13.42), estimated blood loss in PCNL ≥500 mL (OR=2.78, 95% CI: 2.32–3.61) were the independent risk factors associated with postoperative infection.

Conclusions

Effective control of urinary tract infection, reduction of access number, strict control of blood glucose, length of operation control, reduction of intraoperative bleeding should be considered as measures to prevent postoperative fever for patients with PCNL.

Effects of irrigation parameters and access sheath size on the intra-renal temperature during flexible ureteroscopy with a high-power laser

OBJECTIVES

To investigate the effect of different laser power settings on intra-renal temperature (IRT) under different irrigation conditions during flexible ureteroscopy (FURS) in a live-anesthetized porcine model.

METHODS

Following ethics approval, 2 female pigs weighing ~ 28 kg were used. Under general anesthesia, a percutaneous access was obtained to fix a K-type thermocouple inside the pelvi-calyceal system for real-time recording of IRT during FURS without UAS, UAS-10/12, UAS-12/14, and UAS-14/16F. A high-power holmium laser was used and the IRT was recorded during laser activation for up to 60 s at a laser power of 20 W, 40 W, and 60 W under gravity irrigation and manual pump irrigation.

RESULTS

Under gravity irrigation, FURS without UAS was associated with hazardous IRT at a laser power as low as 20 W for as short as 20 s of laser activation. The IRT was rendered borderline when UAS was used. This UAS buffering effect disappeared with the use of higher laser-power settings (40 W and 60 W) with the maximal IRT exceeding 60 °C. Moreover, laser activation at 60 W was associated with very rapid increase in IRT within few seconds. Under pump irrigation, laser activation at the highest power setting (60 W) for 60 s was associated with a safe IRT, even without the use of UAS. The maximal IRT was below 45 °C.

CONCLUSION

The use of high-power Ho:YAG laser carries potentially harmful thermal effect when used under gravity irrigation, even when large-diameter UAS is used. High-power settings (> 40 W) require high irrigation flow. The use of UAS is advisable to reduce the IRT and balance any intra-renal pressure increase.

Prospective Randomized Trial Comparing the Safety and Clarity of Water Versus Saline Irrigant in Ureteroscopy

BACKGROUND

Water irrigant is discouraged in ureteroscopy due to risks demonstrated in more invasive endoscopic procedures. However, water is not well studied in ureteroscopy and may provide better visualization than standard saline.

OBJECTIVE

To determine whether water irrigant increases the risk of hyponatremia compared with saline and provides better visualization in ureteroscopy.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, prospective, double-blinded trial was conducted. In 2017, eligible adult ureteroscopy patients at a university hospital were recruited for the study.

INTERVENTION

Participants randomized to water or saline irrigant in ureteroscopy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Serum sodium and osmolality, body temperature, subjective surgeon visualization, and objective turbidity clarity were analyzed. Chi-square or Fisher's exact tests for categorical variables and analysis of variance test for continuous variables were performed.

RESULTS AND LIMITATIONS

A total of 121 individuals (mean age 57 ± 15 yr) underwent ureteroscopy (mean time 35 ± 18 min) with a mean irrigation volume of 839 ± 608 ml. For the 101 (83%) patients who had nephrolithiasis, the mean number of stones was 2 ± 1 and the mean stone burden was 13 ± 7 mm. There were no significant differences in demographic, clinical, and intraoperative variables between water and saline groups, except for a higher body mass index in the saline group (p = 0.01). There was no significant difference between groups in the incidence of hyponatremia, hypo-osmolality, or hypothermia. The median surgeon visualization score was significantly higher using water (p < 0.01). The mean turbidity was significantly lower with water (p = 0.02). Limitations were not objectively assessing hemolysis or fluid absorption.

CONCLUSIONS

Water irrigant does not increase the incidence of hyponatremia in uncomplicated ureteroscopy and provides clearer visualization than saline.

PATIENT SUMMARY

We compared safety and clarity of water and saline irrigation, which aid surgeon visualization, in ureteroscopy, which can treat kidney stones. We found that water irrigant does not reduce blood sodium levels significantly compared with saline in ureteroscopy and provides better visualization.

Percutaneous Nephrolithotomy with Different Temperature Irrigation and Effects on Surgical Complications and Anesthesiology Applications

OBJECTIVE

Percutaneous nephrolithotomy (PCNL) is a widely accepted and frequently performed operation for large kidney stones. However, there is not much information about the effects of irrigation fluid temperature as well as many other factors that affect success and complications during the operation. In this study, we aimed to investigate the surgical and anesthesiological effects of irrigation fluid used in body temperature and room temperature during and after PCNL.

MATERIAL AND METHODS

A total of 108 PCNL patients were performed between June 2016 and April 2018. The half of these patients (54) were performed with body temperature (37°C) irrigation fluid, hence known as body temperature group (BTG), and the other half with room temperature (22°C) irrigation fluid, called as room temperature group (RTG). For the study, we recorded the body temperature of the patients during and after the operation, the amount of irrigation fluid used, the size and location of the kidney stones, the duration of the operation, postoperative shivering time during the patient's wake-up period, pre- and postoperative hemoglobin value, additional blood requirements, postoperative analgesic requirements, and postoperative urinary tract infections.

RESULTS

The age of patients, gender distribution, height, weight, body mass index, stone size, and postoperative analgesic requirement showed no significant differences in two groups. The postoperative body heat was significantly higher in the BTG than the RTG. The duration of waking was significantly higher in the RTG than the BTG. The amount of hemorrhage was significantly less in the patients who were irrigated in the RTG.

CONCLUSION

The temperature of the irrigation fluid can affect many parameters in the PCNL. We recommend using irrigation in room temperature especially with patients having bleeding risks and irrigation fluid in body temperature especially with patients having anesthetic risks for easier waking process.

Effects of fluid absorption following percutaneous nephrolithotomy: Changes in blood cell indices and electrolytes

Background and Aims:

Effects of fluid absorption on hematological profile in the immediate postoperative period in patients undergoing percutaneous nephrolithotomy (PCNL) have not been given due importance. Considering the limited number of studies available, we conducted this study to evaluate the changes in hemodynamics, complete blood count (CBC), and electrolytes in patients undergoing PCNL using normal saline for irrigation in the prone position. Furthermore, we evaluated the common factors known to affect the absorption.

Materials and Methods:

Forty American Society of Anesthesiologist Class I or II patients aged 18–65 years were recruited who underwent PCNL under general anesthesia. Heart rate, blood pressure (BP), CBC, and serum electrolytes were recorded preoperatively and just before extubation and compared using the Student's t-test. Correlation of these changes with height and total volume of irrigating fluid, total time of irrigation, duration of operation, and total intravenous fluids administered intraoperatively were performed using the Pearson's correlation coefficient.

Results:

There was a statistically significant fall in mean hemoglobin (12.5 g/dL to 11.5 g/dL), packed cell volume (38.6%–35.6%), platelet count (2.9 × 10⁵ cells/μL to 2.5 × 10⁵ cells/μL), and sodium ion concentration (Na⁺) (138.9 meq/L to 137.7 meq/L) in the immediate postoperative period as compared to that of the preoperative values. Rest of the blood indices and electrolytes did not show any significant change. There was a significant rise in postoperative heart rate and BP. Postoperative systolic BP showed a significant positive correlation with the total volume of irrigating fluid. No significant correlation was observed with height and total time of irrigation.

Conclusion:

This study reveals that there is a significant fall in hemoglobin and Na⁺ during PCNL in the immediate postoperative period. Only, total volume of irrigating fluid and total duration of surgery had a significant correlation with blood cell indices.

Advances in Lasers for the Treatment of Stones-a Systematic Review

PURPOSE OF REVIEW

Laser lithotripsy is increasingly used worldwide and is a continuously evolving field with new and extensive research being published every year.

RECENT FINDINGS

Variable pulse length Ho:YAG lithotripters allow new lithotripsy parameters to be manipulated, and there is an effort to integrate new technologies into lithotripters. Pulsed thulium lasers seem to be a viable alternative to holmium lasers. The performance of similar laser fibers varies from manufacturer to manufacturer. Special laser fibers and "cleaving only" fiber tip preparation can be beneficial for the lithotripsy procedure. Different laser settings and the surgical technique employed can have significant impact on the success of laser lithotripsy. When safely done, complications of laser lithotripsy are rare and concern the endoscopic nature of procedure, not the technology itself, making laser lithotripsy one of the safest tools in urology. Laser lithotripsy has had several new developments and more insight has been gained in recent years with many more advances expected in the future.

Research progress of percutaneous nephrolithotomy

Percutaneous nephrolithotomy (PCNL) is generally accepted as the gold standard treatment for the treatment of large kidney stones (> 2 cm). For nearly 40 years, with the continuous progress of technology and the constant updating of ideas, PCNL has made great progress. In this review, we discuss the current research progress, recent advancement and hot spot of the whole process of PCNL including anesthesia, position, puncture, dilation, lithotripsy approaches, perfusate, tube placement, hospitalization time, drug, treatment of residual stones, prognosis judgment and operation evaluation by summarizing the related research in this article.

Micro-ureteroscopy vs. ureteroscopy: effects of miniaturization on renal vascularization and intrapelvic pressure

PURPOSE

Ureteroscopy (URS) is related to complications, as fever or postoperative urinary sepsis, due to high intrapelvic pressure (IPP) during the procedure. Micro-ureteroscopy (m-URS) aims to reduce morbidity by miniaturizing the instrument. The objective of this study is to compare IPP and changes in renal haemodynamics, while performing m-URS vs. conventional URS.

METHODS

A porcine model involving 14 female pigs was used in this experimental study. Two surgeons performed 7 URS (8/9.8 Fr), for 45 min, and 7 m-URS (4.85 Fr), for 60 min, representing a total of 28 procedures in 14 animals. A catheter pressure transducer measured IPP every 5 min. Haemodynamic parameters were evaluated by Doppler ultrasound. The volume of irrigation fluid employed in each procedure was also measured.

RESULTS

The range of average pressures was 5.08-14.1 mmHg in the m-URS group and 6.08-20.64 mmHg in the URS (NS). 30 mmHg of IPP were not reached in 90% of renal units examined with m-URS, as compared to 65% of renal units in the URS group. Mean peak diastolic velocity decreased from 15.93 to 15.22 cm/s (NS) in the URS group and from 19.26 to 12.87 cm/s in the m-URS group (p < 0.01). Mean resistive index increased in both groups (p < 0.01). Irrigation fluid volume used was 485 mL in the m-URS group and 1475 mL in the URS group (p < 0.001).

CONCLUSIONS

m-URS requires less saline irrigation volumes than the conventional ureteroscopy and increases renal IPP to a lesser extent.