Ultrasound-guided Percutaneous Nephrolithotomy Research Articles

Initial clinical experience of real-time ultrasound-guided percutaneous nephrolithotomy using the SonixGPS guidance positioning system

Objective To evaluate the feasibility and safety of SonixGPS guidance positioning system in PCNL.Methods In May 2012,a total of 15 patients with upper urinary tract calculi underwent PCNL by combining pneumatic and ultrasonic power (fourth generations of EMS) with the navigation of SonixGPS guidance positioning system.A 16 G proprietary needle was inserted into the fornix of targeted calyx under the navigation of SonixGPS,needle-beam alignment and correct trajectory were maintained by observing the indicator on the screen of SonixTouch ultrasound system.Preoperative imaging,including plain abdominal film of kidney,ureter,and bladder (KUB),ultrasonography,computed tomography with or without intravenous urography.Eleven patients had different degree of hydronephrosis.Four patients had urinary infection and received antibiotic treatment before operation.Of the 15 patients,7 had multiple calculi,3 had staghorn calculi,3 had upper ureteral calculi,and 2 had renal and ureteral calculi.Results The percutaneous renal access was successfully established in 15 patients and followed with phase Ⅰ lithotripsy.The mean operative time was 45 minutes,and the mean time of making a successful percutaneous access to the renal collecting system from an appropriate calyx was 4 minutes.Postoperative KUB demonstrated stone-free after primary procedure in 14 patients (93％),and 1 patient need extracorporeal shock wave lithotripsy.No severe complication was detected in all 15 patients.Conclusions Real-time ultrasound-guided PCNL using the SonixGPS guidance positioning system appears to be safe and efficacious.SonixGPS helps predict and clearly observe the needle's trajectory during invasive procedures.It helps improve skills in performing percutaneous access and reduces the learning curve for PCNL.The major limitation of this study was that it was a case controlled study and not a randomized double-blind study.These results should be proved by further large-scale and multi-center clinical study. Key words: Percutaneous nephrolithotomy; Ultrasound-guided; Navigation; Renal calculi

Supplementary X-Ray for Ultrasound-Guided Percutaneous Nephrolithotomy in Supine Position versus Standard Technique: A Randomized Controlled Trial

Objectives: To compare the success and complication rates of sonography-guided supine percutaneous nephrolithotomy (PCNL) versus prone standard technique (fluoroscopic guidance) in a randomized controlled trial. Subjects and Methods: Between April 2009 and August 2011, 92 candidates for PCNL were randomly divided into two groups: 46 B-mode sonography-guided supine PCNL (group A) and 46 standard fluoroscopic-guided prone PCNL (group B). Demographic, clinical and perioperative patient characteristics were analyzed, and complications and success rates were compared between the two approaches. Results: Preoperative parameters were comparable in the two groups. The primary success rate was 79.0 and 65.2% in groups A and B, respectively, after one session of PCNL (p = 0.485). Sonography-guided access failed in 3 cases (failure rate 6.5% in group A vs. 0% in group B). Mean hospital stay (2.48 days for group A vs. 2.95 days for group B; p = 0.039) and mean nephrostomy tube stay time (1.79 days for group A vs. 2.56 days for group B; p = 0.007) were significantly prolonged in the standard technique. Postoperative fever was more prevalent in the standard PCNL group (p = 0.024), but no significant difference was observed in other complications between the two groups. Conclusion: In this study, sonography-guided supine PCNL was presented as a safe and effective technique, similar to standard PCNL, with comparable success and complication rates. In addition, using this technique eliminates the possible harmful impacts of radiation on the surgical team and decreases postoperative fever.

Prone versus Modified Supine Position in Percutaneous Nephrolithotomy: a Prospective Randomized Study

Objective: To perform a prospective randomized trial comparing the efficacy and safety of percutaneous nephrolithotomy (PCNL) in the prone and modified supine positions.Methods: Between August 2010 and August 2011, 102 patients with renal calculi and 20 patients with ureteral calculi were randomized to undergo fluoroscopy and ultrasound-guided PCNL procedures in the prone or modified supine position. Baseline characteristics, puncture position, numbers of punctures, operation time, stone free rate, loss of blood, hospital stay and second phase PCNL were compared in the two groups.Results: There were no significant differences in gender, age, body mass index, stone location, stone size and the presence of hydronephrosis between the two groups. The rate of second PCNL was significantly higher and the stone clearance rate was significantly lower in the modified supine than in the prone position group. Mean operation time was significantly lower in the prone than in the modified supine position group (78 min vs 88 min, P<0.05). There were no significant differences in rates of rib and calyx puncture, numbers of punctures, mean blood loss, and mean hospital stay between the two groups.Conclusions: Both the prone and modified supine positions are effective and safe for PCNL. Operation time was longer in the modified supine group, and patients undergoing PCNL in the modified supine position more frequently required a second operation due to a lower stone clearance rate.

Post-Percutaneous Nephrolithotomy Septic Shock and Severe Hemorrhage: A Study of Risk Factors

Objective: To identify the risk factors predicting septic shock and severe hemorrhage in percutaneous nephrolithotomy (PCNL). Methods: We retrospectively analyzed 420 renal calculi patients who underwent ultrasound-guided PCNL from March 2005 to May 2011. Data on patients who experienced infectious shock requiring anti-shock therapy and severe renal bleeding requiring angiographic renal embolization or nephrectomy were compared with other patients using univariate analyses. Results: Of 420 patients, 10 (2.4%) suffered septic shock and 4 (1%) had severe hemorrhage. The two significant risk factors for infectious shock were preoperative urine white blood cell count and operation time. For severe bleeding the absence of hydronephrosis and puncture time were significant risk factors. Operation time >90 min was associated with both septic shock and severe renal bleeding (p = 0.017). In contrast, the risk of encountering severe renal bleeding was higher if a nephroscope rather than a ureteroscope was used (p = 0.045). Conclusions: Operation time was a risk factor for both septic shock and severe hemorrhage. The patients without hydronephrosis before operation were more likely to suffer severe renal bleeding. Reducing intraoperative puncture time can reduce the probability of severe post-PCNL hemorrhage. The use of a comparatively gross nephroscope passage was likely to result in severe renal bleeding.

Doppler Ultrasound-guided Percutaneous Nephrolithotomy With Two-step Tract Dilation for Management of Complex Renal Stones

To report our experience and assess the safety and efficacy of Doppler ultrasound-guided percutaneous nephrolithotomy (PCNL) with 2-step tract dilation for complex renal stones. From March 2009 to February 2011, 262 patients underwent PCNL. Eighty-three patients had a complete and 105 had partial staghorn calculus, and 74 had a renal pelvic stone of >2 cm in diameter. Thirty-five patients had renal surgical history. Doppler ultrasound-guided PCNL with 2-step tract dilation were performed. Stones were fragmented and cleared using a combination of ultrasonic and pneumatic lithotripters. All PCNL procedures were successful. Successful access to the collecting system was 100%. Although most of the cases (231/262) were managed satisfactorily by a single tract, a second tract was used in 31 cases. Mean operation time was 56 minutes (range 25-145). The primary stone-free rate of PCNL was 80.9%. There were 39 auxiliary procedures (13 second PCNL and 26 extracorporeal shock wave lithotripsy). One month after treatment, the overall stone-free rate was 92.7%. Five patients (1.9%) received blood transfusion. Eight patients (3.1%) with a postoperative fever of ≥38.5°C were cured by intravenous antibiotics. No other severe complications occurred. The mean postoperative stay was 3.8 days (range 2-12). Doppler ultrasound-guided PCNL with 2-step tract dilation for complex renal stones is safe, effective, and worthy of wider use in clinical practice.

Safety and Efficacy of Ultrasound-guided Percutaneous Nephrolithotomy for Treatment of Urinary Stone Disease in Children

To present the feasibility and efficacy of ultrasound-guided percutaneous nephrolithotomy for the treatment of urinary stone disease in children. The medical records and files of 17 patients with renal stones (17 renal units) who were aged ≤ 16 years who had undergone ultrasound-guided percutaneous nephrolithotomy from 2008 to 2010 were retrospectively reviewed and analyzed. Ultrasonography was used for guidance in all patients in every step of the procedure. Fluoroscopy was used to aid in tract dilation in the initial cases of the series and to evaluate for stone clearance in all cases. The operative and postoperative findings were assessed. The average age of the patients was 8.8 ± 2.86 years (range 5-15). The mean stone size was calculated as 337.4 ± 52.9 mm(2) (range 260-446). The mean operative time was 67.9 ± 14.58 minutes (range 45-95). Fever, urine leakage, and bleeding requiring blood transfusion were observed in 3, 1, and 1 patient, respectively. The fluoroscopic screening time was limited to 17.76 ± 15.5 seconds (range 1-54). Neighboring organ injuries were not observed. The overall success rate improved from 82.35% to 100% with additional treatment modalities (shock wave lithotripsy in 2 and ureteroscopy in 1). Percutaneous nephrolithotomy can be safely performed with ultrasound guidance in children, providing the advantages of less radiation exposure, no adjacent organ injury, and similar success and complication rates compared with fluoroscopic guidance.

Doppler Ultrasound-guided Percutaneous Nephrolithotomy: A Prospective Randomized Study

To evaluate the role, safety, and effectiveness of Doppler ultrasound-guided percutaneous nephrolithotomy (PCNL). The present study was a prospectively randomized controlled trial performed from March 2007 to February 2010. A total of 131 patients, scheduled for PCNL to remove huge renal stones (diameter>35 mm) and staghorn stones, were enrolled and prospectively randomized using a random numbers table into 2 groups. Of the 131 patients, 54 were randomized to ultrasound-guided puncture PCNL (group 1). Group 2 included 57 patients who received Doppler ultrasound-guided PCNL. A total of 30 patients were excluded from the study. The preoperative data included urinalysis, urine culture, complete blood count, biochemistry study, renal ultrasonography, intravenous urography, and technetium-99m diethylenetriaminepentaacetic acid to determine the selective glomerular filtration rate. The intraoperative findings, operative time (from insertion of the puncture needle to the end of the procedure), and outcomes were also recorded. The complete blood count and serum creatinine were also checked. The modified Clavien grading system was used to evaluate the perioperative morbidity of PCNL. No difference was found between the 2 groups with regard to the serum creatinine change, length of stay, return to normal activity, Clavien grade, relative perfusion rate, or glomerular filtration rate, as determined by technetium-99m diethylenetriaminepentaacetic acid clearance, preoperatively and postoperatively. However, the hemoglobin decrease (2.33±0.46 g/dL) in the ultrasound-guided puncture group was greater than that in the Doppler ultrasound-guided group, with statistically significant difference. Doppler ultrasound-guided PCNL is accurate and safe and was associated with less blood loss. We believe that Doppler ultrasound can be an important alternative to B-mode ultrasound guidance.

Ultrasound-guided X-ray free percutaneous nephrolithotomy for treatment of simple stones in the flank position

The purpose of this study was to examine the effectiveness and safety of percutaneous nephrolithotomy with ultrasonography-guided renal access in the flank position without the use of fluoroscopy in any stage of the procedure. Percutaneous nephrolithotomy was performed in flank position under the guidance of ultrasound (USG) without the use of fluoroscopy between December 2008 and January 2010 on 43 patients who had kidney stones bigger than 20mm. Access to the kidney's proper calyx was achieved by dilatation through the guide wire placed after insertion of the needle through the needle director under the guidance of transrectal ultrasound probe placed on the patient's flank area. A convex USG probe was used for imaging during dilatation and lithotripsy instead of fluoroscopy. Access to the targeted calyx was achieved successfully in all patients (100%). The percentage stone free rate was 86.1% (37 patients). Residual stones were detected in six patients. Their dimensions ranged from 5 to 12mm. The mean stone diameter was 29 (20-41) mm, duration of surgery was 87.1±43.2 (55-210)min and duration of hospital stay was 3.1 (2-8) days. Blood transfusions were given to two patients; none of the patients had major intraoperative or postoperative complications. In comparison with standard percutaneous nephrolithotomy, percutaneous nephrolithotomy in flank position under ultrasonographic imaging instead of using fluoroscopy seems to be safe and effective. This procedure has to be limited to selected cases with one or maximum two big stones in the pelvis or in a single calyx in absence of complex intrarenal anatomy. Both surgical team and the patients were protected from the harmful effects of radiation. Regarding anesthesia, flank position is more comfortable for the patient than prone position.

The Combination of Laparoscopy and Nephroscopy for Treatment of Stones in Pelvic Ectopic Kidneys

Introduction: Minimally invasive treatment modalities for patients with large stone burden within pelvic kidneys present a special challenge. Interposing bowel loops between the kidney and the anterior abdominal wall, abnormalities in the vascular supply, and mal-rotation of the caliceal system are reasons of difficulties in percutaneous nephrolithotomy (PNL). Minimally invasive treatment modalities of large stones in ectopic pelvic kidneys have included pure laparoscopic pyelolithotomy,1–3 laparoscopy-assisted PNL,4–7 and ultrasound-guided PNL.8 These are attractive treatment options because they have the advantages of reduced analgesic requirement, shorter hospital stay, early convalescence, and better cosmoses in addition to high safety and efficacy profiles. The combination of laparoscopic and percutaneous approaches allows the establishment of the percutaneous tract into the kidney under direct vision, thus avoiding the risk of injury to abdominal viscera and blood vessels. This video presents the technique of the combination of laparoscopy and nephroscopy for treatment of stones in pelvic ectopic kidneys. Patients and Methods: The study included seven men and four women (mean age, 43 ± 9 years). Laparoscopy-assisted PNL was performed for caliceal stones in five patients after failure of shockwave lithotripsy. Laparoscopic pyelolithotomy was performed for six patients with large or branched renal pelvic stones. The patient was placed in the Trendelenburg position with slight lateral elevation of the side to be operated. In laparoscopy-assisted PNL the primary surgeon stands on the same side of the affected kidney and the assistant on the opposite side, whereas in laparoscopic pyelolithotomy the surgeon stands on the opposite side of the affected kidney. Three or four transperitoneal ports were placed in a fan-shaped distribution. The stone or the renal pelvis was identified using intraoperative fluoroscopy. Intermittent fluoroscopy was used to identify the point of entry to the desired calix during dilatation and during fixation of the nephrostomy tube. Results: The average preoperative stone length was 3 ± 1 cm (range, 1.1–4.2). There were some adhesions between the intestinal loops and the peritoneum on the anterior surface of the kidney in three patients (27%). There were neither intraoperative nor postoperative complications, and conversion to open surgery was not required. The mean hospital stay was 3.5 ± 0.7 days (range, 2–4). The stone-free rate was 91% as all stones were removed completely in 10 patients, whereas 1 patient had residual caliceal fragment that was treated with shockwave lithotripsy. After a mean follow-up of 27 ± 6 months, two out of the five patients who underwent laparoscopy-assisted PNL showed stone recurrence and were treated with extracorporeal shockwave lithotripsy. Conclusion: The combination of laparoscopy and nephroscopy for treatment of stones in pelvic kidneys is feasible, safe, and effective. The authors has nothing to disclose. Runtime of video: 8 min 24 sec

X-ray-free percutaneous nephrolithotomy in supine position with ultrasound guidance

Supine percutaneous nephrolithotomy (PCNL) has numerous benefits compared to the prone position, including lower anesthesia risk, shorter operating time, and better ergonomic position for the surgeon. It is also comparable to prone position regarding vascular and bowel injuries. This study was conducted to add some more benefits by omitting X-ray in PCNL in a supine position. Nineteen consecutive adult patients underwent ultrasound-guided PCNL in supine position. All patients were placed under ultrasound guidance in supine position. The tract was dilated over a guidewire in a single shot technique under ultrasound guidance from anterior abdominal wall. Once the procedure ended, residual stone was controlled using ultrasound with anterior abdominal wall window. Residual stones less than 5 mm were considered insignificant. No X-ray was used in any setting of the procedure. The pelvicaliceal system could be successfully approached in all patients. The posterior calices were the most common sites of entry. Mean (range) of operation time was 111 (70-180) min. Mean + or - SD hemoglobin before PCNL was 14.0 + or - 2.2 mg/dl, and after the procedure it was 12.3 + or - 1.6 mg/dl. Only one patient required blood transfusion. Mean + or - SD creatinine before PCNL was 1.03 + or - 0.24 mg/dl, and after the procedure it was 1.11 + or - 0.22 mg/dl. None of the patients suffered visceral injury. The total stone-free rate was 84%. Even in our first report with limited experience, it seems that the efficacy of PCNL with ultrasonography in supine position is comparable to PCNL in prone position with fluoroscopy with no more complications.

Ultrasonography-Guided Percutaneous Nephrolithotomy

To evaluate the safety and efficacy of ultrasound-guided percutaneous nephrolithotomy (PCNL). Between August 2003 and December 2007, 47 patients were treated, 29 men and 18 women, with a mean age of 33.4 years (range 21-67 yrs) and a mean stone size of 31.5 mm (range 24-46 mm). All stones were located in the renal pelvis with mild to moderate hydronephrosis seen on intravenous urography. A ureteral stent was inserted cystoscopically, and saline was injected for more localization of the pelvicaliceal system (PCS), if needed. Puncture of the PCS was performed with an 18-gauge nephrostomy needle through the lower pole calyx, and all the stages, including dilatation, were performed under ultrasonography guidance. Thirty-nine patients were stone free in the kidneys, ureters, and bladder the day after the operation. Five patients had multiple fragments that measured about 4 to 5 mm, which passed in 4 weeks (total stone-free rate: 93.61%); failure occurred in two patients, and fluoroscopy was needed; two patients who had residual fragments that measured 10 and 12 mm underwent shockwave lithotripsy; and in one patient, a fragment that measured 7 to 8 mm migrated into the ureter--it fragmented and was removed with a ureteroscope 2 days after the operation. PCNL using sonography is a good alternative to the fluoroscopic method. It is performed without radiation exposure to the surgeon and patient; however, more experience is needed.