Staged retrograde endoscopic lithotripsy as alternative to PCNL in select patients with large renal calculi

Renal pseudoaneurysm after holmium laser lithotripsy with flexible ureteroscopy: an unusual case report and literature review

Pseudoaneurysms of the renal arteries are caused by focal rupture or perforation of the arterial wall, resulting in local bleeding. Such pseudoaneurysms can be observed in conditions such as nodular polyarteritis, penetrating or closed renal injury, and medically induced injuries (such as renal puncture biopsy, percutaneous nephrostomy, or partial nephrectomy). Flexible ureteroscopy (FURS) is performed entirely through the urethra to prevent potentially severe kidney damage. Because of this, almost no renal parenchymal hemorrhage occurs after FURS laser lithotripsy. Only four cases had been documented in the literature as of December 2022. In this report, we describe a 53-year-old man with a history of recurrent kidney stones who underwent FURS laser lithotripsy for bilateral kidney stones. The procedure was smoothly performed, and no active bleeding occurred. However, the patient developed recurrent macroscopic hematuria after discharge from the hospital, and renal angiography revealed a pseudoaneurysm in the distal right kidney. The pseudoaneurysm was treated with selective arterial embolization. Serious complications of FURS surgery are rare, particularly the formation of pseudoaneurysms. We report the present case to bring this potential complication to the attention of urologists.

Ambulatory Minimally Invasive Endoscopic Combined Intrarenal Surgery in Management of Large Impacted Proximal Ureteral Calculi: A Feasibility Study at a Tertiary Referral Center

Aim: To conduct a comparative, nonrandomized study to assess the feasibility of mini-Endoscopic Combined Intrarenal Surgery (ECIRS) using supine Mini-percutaneous nephrolithotomy (PCNL) access (16F) in Galdakao-Modified Supine Valdivia position for managing proximal large-volume impacted ureteral calculi as ambulatory day-care surgery vis-a-vis standalone ureteroscopy (URS) with push-back PCNL, if needed. The primary aim was to study the outcomes and stone-free rates (SFRs). Secondary aim was to compare the intraoperative and short-term postoperative complications. Materials and Methods: Data of 60 patients undergoing ECIRS (Group 1) from January 2016 to December 2019 were collected prospectively in a nonrandomized fashion from a single center after Ethics Committee approval. A matched-paired analysis was performed with retrospectively collated data of 60 patients undergoing standard URS/pushback PCNL (Group 2) using analysis of variance, Fisher's exact test, and Chi-square test. p < 0.05 was considered statistically significant. Outcomes and Results: Group 1 patients had a significantly shorter procedure time vs Group 2 (42.1 ± 11.2 minutes vs 52.1 ± 13.7 minutes; p < 0.001). Group 1 (59/60) patients had an overall single stage SFR of 98.3%, which was significantly higher than single-stage SFR of 83% in Group 2 (50/60) (p < 0.002). Group 2 patients had a higher incidence of fever (10 vs 4, p = 0.01). However, there were no cases of sepsis in either group. Rest of the complications were comparable for both, as the need for ancillary procedures was significantly higher in Group 2 (10% vs 1.7%, p < 0.001). Patients were discharged on the same day in both groups. Conclusions: The findings of our study suggest that, in large and impacted proximal ureteric stones, combined minimally invasive endoscopic approach offers the best option to render the patient stone free by a single intervention. With better intra- and postoperative outcomes and safety profile, Mini-ECIRS may be considered as an ambulatory procedure in this setting.

Percutaneous Nephrolithotomy in Patients with Chronic Kidney Disease: A Systematic Review

BACKGROUND

Renal calculi in chronic kidney disease (CKD) are not uncommon. Percutaneous nephrolithotomy (PCNL) is a standard treatment for large renal calculi. PCNL in CKD has been a subject of debate as it may improve the renal function with stone clearance but may be associated with an increased complication rate. Studying the impact of PCNL in CKD patients is of utmost significance.

OBJECTIVE

The aim of the study was to evaluate the efficacy and safety of PCNL in patients with renal insufficiency in order to provide clinicians expected outcomes to effectively counsel patients.

METHODS

We performed a systematic review of clinical trials reporting the outcomes of PCNL in CKD patients. The search was performed in MEDLINE, EMBASE, Cochrane Library, CINAHL, Google Scholar, and Web of Science. All studies with a minimum of 15 patients carried out in the last 20 years were selected. A total of 13 studies involving 2,192 patients were included for final analysis. The pre-operative and post-operative renal function was compared. Post-procedure complications were analysed. Evidence Analysis: The majority of patients in all studies except one had either improvement or stabilization in renal function. The complication rate was 31.9%, which was more than that in patients with normal renal function.

CONCLUSION

Our review suggested that the majority of the patients of renal calculus with renal insufficiency are benefitted with PCNL in improving or preserving the renal function. But the post-operative complications are more in CKD and increases as the severity of renal insufficiency increases.

Retrograde intrarenal surgery: Past, present, and future

With the recent technological advancements in endourology, retrograde intrarenal surgery has become a more popular procedure for treatment of urolithiasis. Furthermore, since the introduction of new laser systems and advanced flexible ureteroscopy with miniaturized ureteroscopes, the treatment indications for retrograde intrarenal surgery have expanded to include not only larger renal stones of >2 cm but also upper urinary tract urothelial carcinoma, ureteral stricture, and idiopathic renal hematuria. Clinicians must keep up with these trends and make good use of these technologies in the rapidly changing field of endourology. Simultaneously, we must consider the risk of various complications including thermal injury due to laser use, ureteral injury caused by the ureteral access sheath, and radiation exposure during retrograde intrarenal surgery with fluoroscopic guidance. This review focuses on the past, present, and future of retrograde intrarenal surgery and provides many topics and clinical options for urologists to consider.

Efficacy and safety of fURS in stones larger than 20 mm: is it still the threshold?

Introduction

The aim of this article was to evaluate the safety and efficiency of flexible ureteroscopy (fURS) in the management of renal calculi larger than 20 mm.

Material and methods

A total of 92 cases with renal calculi were managed with fURS and divided into two groups depending on the size of the stones; <20 mm and >20 mm (Group 1 and Group 2, respectively). The groups were compared with respect to treatment-related parameters including success, complication rates, hospitalization period and need for auxiliary procedures with an emphasis on the rate of infections. Success rates were also compared in each group according to stone location.

Results

Overall success rates after 3 months showed that stone-free rates in both groups were 84.1% (< 20 mm) and 58.33% (>20 mm) respectively (p = 0.008). The success rates of upper/mid pole (100% vs. 80%) and pelvis stones (83.3% vs. 75%) showed no statistically significant difference (p = 0.5, p = 0.51 respectively). Success rates for stones located in the lower pole were 75% vs. 14.28% respectively (p = 0.008). The rate of infectious complications was significantly higher in cases undergoing fURS for relatively larger stones (22.9%) as compared to smaller calculi (6.8%) (p = 0.032). No complications were recorded in Group 1, while 2 cases in Group 2 (4.1%) developed ureteral stricture.

Conclusions

Despite the relatively low stone-free rates in lower pole stones, our current results indicate that fURS can be an effective and safe treatment alternative to PNL in larger renal stones (>20 mm) located in the pelvis and in the upper part of the calyceal system of the involved kidney.

The "old" 15 mm renal stone size limit for RIRS remains a clinically significant threshold size

PURPOSE

To investigate the performance of retrograde intrarenal surgery (RIRS) for the 1-2 cm renal stone size range in comparison to smaller stones.

MATERIALS AND METHODS

From a data base of 3000 ureteroscopies between 2004 and 2014, 635 consecutive patients underwent RIRS for renal stones. Patients were divided to three groups according to their renal stone size (<10, 10-15, 15-20 mm). Preoperative, operative, stone free rate (SFR) and follow-up data were analyzed and compared.

RESULTS

The SFR for the three groups was 94.1, 90.1 and 85%, respectively. Patients with renal stone size above 15 mm had a statistically significantly lower SFR. The efficiency quotient calculated for stones larger and smaller than 15 mm was 83.9 vs. 91.8%, respectively (p < 0.01). The mean operative time and hospital stay were longer for patients with renal stones larger than 15 mm (73.6 ± 29.9 vs. 53 ± 19.4 min, p < 0.01 and 2.2 ± 2 vs. 1.8 ± 1.8 days, p = 0.031, respectively). Moreover, the complication rate was almost two times higher (10 vs 5.4%, p = 0.08). Concomitant ureteral stones and older age were independent predictors of failure in the large stone group.

CONCLUSIONS

While the overall SFR following RIRS for renal stones up to 2 cm is generally high, the SFR for 15-20 mm stones is significantly lower, with a longer operating time and hospital stay, and a higher complication rate.

Intrarenal Surgery vs Percutaneous Nephrolithotomy in the Management of Lower Pole Stones Greater than 2 cm

Purpose

To compare the efficacy of RIRS and PNL in lower pole stones ≥2 cm. Materials and and Methods: A total of 109 patients who underwent PNL or RIRS for solitary lower pole stone between April 2009 and December 2012, were retrospectively analyzed. Lower pole stone was diagnosed with CT scan. Stone size was assessed as the longest axis of the stone. All patients were informed about the advantages, disadvantages and probable complications of both PNL and RIRS before the selection of the procedure. Patients decided the surgery type by themselves without being under any influences and written informed consent was obtained from all patients prior to the surgery. Patients were divided into two groups according to the patients’ preference of surgery type. Group 1 consisted of 77 patients who underwent PNL and Group 2 consisted of 32 patients treated with RIRS. Stone free statuses, postoperative complications, operative time and hospitalization time were compared in both groups.

Results

There was no statistical significance between the two groups in mean age, stone size, stone laterality, mean follow-up periods and mean operative times. In PNL group, stone-free rate was 96.1% at first session and 100% after the additional procedure. In Group 2, stone-free rate was 90.6% at the first procedure and 100% after the additional procedure. The final stone-free rates and operative times were similar in both groups.

Conclusions

RIRS should be an effective treatment alternative to PNL in lower pole stones larger than 2 cm, especially in selected patients.

Percutaneous nephrolithotomy in octogenarians and beyond: How old is too old?

Objective

To specifically report perioperative characteristics and outcomes in patients 80 years and older undergoing percutaneous nephrolithotomy (PCNL). PCNL has been established as feasible in the elderly; however, to our knowledge no one has specifically reported feasibility in patients 80 years and older.

Methods

We retrospectively reviewed perioperative data of octogenarians who underwent PCNL at a high stone volume single institution, and matched them to patients <65 years of age by stone burden and sex. Patient demographics, perioperative outcomes and postoperative complications were compared.

Results

Thirty-three octogenarians (mean age 83.6 years) with 36 renal units were matched to 67 controls (mean age 48.6 years) with 72 renal units. Octogenarians had a higher mean American Society of Anesthesiologists (ASA) score, more comorbidities, and worse renal function. There were no differences in operative characteristics, length of hospital stay or stone free rates. Of the patients with preoperative urinary decompression (ureteral stent or nephrostomy tube) prior to PCNL, the elderly were more likely to have a history of urosepsis. Octogenarians did not experience more minor Clavien (I – II) or major Clavien (IIIa – IVb) complications.

Conclusion

Octogenarians who undergo PCNL were more likely to have cardiovascular comorbidities and a prior history of sepsis. Despite these risk factors, in appropriately selected patients PCNL can be safely and successfully performed in octogenarians without increased perioperative complications relative to a younger cohort.

Appropriate kidney stone size for ureteroscopic lithotripsy: When to switch to a percutaneous approach

Flexible ureteroscopy (fURS) has become a more effective and safer treatment for whole upper urinary tract stones. Percutaneous nephrolithotomy (PNL) is currently the first-line recommended treatment for large kidney stones ≥ 20 mm and it has an excellent stone-free rate for large kidney stones. However, its invasiveness is not negligible considering its major complication rates. Staged fURS is a practical treatment for such large kidney stones because fURS has a minimal blood transfusion risk, short hospitalization and few restrictions on daily routines. However, as the stone size becomes larger, the stone-free rate decreases, and the number of operations required increases. Therefore, in our opinion, staged fURS is a practical option for kidney stones 20 to 40 mm. Miniaturized PNL combined with fURS should be considered to be a preferred option for stones larger than 40 mm. Moreover, URS is an effective treatment for multiple upper urinary tract stones. Especially for patients with a stone burden < 20 mm, URS is a favorable option that promises a high stone-free rate after a single session either unilaterally or bilaterally. However, for patients with a stone burden ≥ 20 mm, a staged operation should be considered to achieve stone-free status.

Ureteroscopy and laser lithotripsy: technologic advancements

Ureteroscopic lithotripsy has evolved since the first reported cases employing rigid rod-lens endoscopes and stiff ultrasonic lithotrites. Fiber optics facilitated rigid endoscope miniaturization and the development of a steerable, deflectable flexible ureteroscopes. Over 30 years of technical innovations culminating in digital imagers and powerful, precise laser lithotrites, complimented by progressive endoscopic techniques have produced efficient endoscopic therapies with minimal morbidity and commonly performed in an outpatient setting.

Retrograde intrarenal surgery for kidney stones larger than 2.5 cm

PURPOSE OF REVIEW

The management of large intrarenal stones (>2 cm) is typically percutaneous nephrolithotomy. Although the stone-free rate (SFR) of such a procedure is high (up to 95%), the complications related mainly to the renal access are sometimes a concern. Because of the evolution in technology, it is nowadays possible to treat intrarenal stones with retrograde intrarenal surgery. It remains unclear weather or not retrograde intrarenal surgery (RIRS) may be effective also for the treatment of larger stones (>2 cm). The purpose of this review is to provide recent data on the ureteroscopic management of kidney stones larger than 2.5 cm.

RECENT FINDINGS

A systematic review of the literature for studies identified between January 2000 and September 2013 was performed. Only English language articles reporting on more than 10 cases treated with RIRS for intrarenal stones larger than 2.5 cm were considered for this review.Particular emphasis was given to studies published within the last 12 months. Of the 324 studies identified, only 10 were considered suitable for this review. There were a total of 441 patients with a mean stone size of 2.9 cm. The SFR with an average of 1.6 procedures was 89.3%. The overall complication rate was 8% with major complication rate of 1.9%.

SUMMARY

Although not supported by high evidence because of the absence of prospective randomized studies, it appears that in selected patients with large intrarenal stones, RIRS and laser lithotripsy may offer an acceptable efficacy with low morbidity.

Percutaneous nephrolithotomy in patients on chronic anticoagulant/antiplatelet therapy

Percutaneous nephrolithotomy (PCNL) is an integral component in the management of large volume renal stone disease either as monotherapy or in combination with shock wave lithotripsy. Stone disease in patients on chronic anticoagulation/antiplatelet therapy, however, poses a difficult scenario. Bleeding is a major concern for any patient undergoing PCNL. We retrospectively analyzed our series of patients with renal calculi who were on chronic anticoagulant therapy and who underwent PCNL. We reviewed the case records of patients undergoing PCNL during the period from January 2005 to December 2011. We analyzed the changes in preoperative and postoperative hemoglobin, serum creatinine, and clotting parameters, as well as intraoperative and postoperative bleeding and thromboembolic complications. During the 5-year study period, a total of 36 patients (30 males and 6 females) with a mean age of 46.33±9.96 years (range, 29-61 years) who were on chronic anticoagulant/antiplatelet therapy underwent PCNL for urolithiasis. The mean size of the stone was 6.40±1.98 cm² (range, 2.8-9 cm²). The mean operating time was 62.08±10.10 min. The bleeding was successfully managed in all patients and the anticoagulant/antiplatelet agents were restarted after an appropriate duration. The mean rise in serum creatinine at discharge was 0.05±0.03 mg/dl and the mean fall in serum hemoglobin was 1.63±0.77 g/dl. At 3 months after surgery, the stone-free rate was 100%. With careful preoperative care and regulation of anticoagulation/antiplatelet therapy and appropriate intraoperative management, PCNL can be performed safely and successfully in properly selected patients with renal calculi who are on chronic anticoagulant/antiplatelet therapy.

Flexible ureteroscopy and laser lithotripsy for stones >2 cm: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Urinary stones >2 cm are traditionally managed with percutaneous nephrolithotomy (PCNL). Recently, flexible ureteroscopy and laser lithotripsy) (FURSL) has been used to manage them with comparable results. In a comparative study of renal stones between 2 and 3 cm, FURSL was reported to need less second-stage procedures and be just as effective as PCNL. Our purpose was to review the literature for renal stones >2 cm managed by ureteroscopy and holmium lasertripsy.

MATERIALS AND METHODS

A systematic review and quantitative meta-analysis was performed using studies identified by a literature search from 1990s (the first reported large renal stones treated ureteroscopically) to August 2011. All English language articles reporting on a minimum of 10 patients treated with FURSL for renal stones >2 cm were included. Two reviewers independently extracted the data from each study. The data of studies with comparable results were included into a meta-analysis.

RESULTS

In nine studies, 445 patients (460 renal units) were reportedly treated with FURSL. The mean operative time was 82.5 minutes (28-215 min). The mean stone-free rate was 93.7% (77%-96.7%), with an average of 1.6 procedures per patient. The mean stone size was 2.5 cm. An overall complication rate was 10.1%. Major complications developed in 21 (5.3%) patients and minor complications developed in 19 (4.8%) patients. A subgroup analysis shows that FURSL has a 95.7% stone-free rate with stones 2-3 cm and 84.6% in those >3 cm (P=0.01), with a minor complication rate of 14.3% and 15.4%, respectively, and a major complication rate of 0% and 11.5%, respectively.

CONCLUSION

In experienced hands, FURSL can successfully treat patients with stones >2 cm with a high stone-free rate and a low complication rate. Although the studies are from high-volume experienced centers and may not be sufficient to alter everyday routine practice, this review has shown that the efficacy of FURSL allows an alternative to PCNL.

A new scoring system for predicting stone-free rate after retrograde intrarenal surgery: the "resorlu-unsal stone score"

OBJECTIVE

To investigate the prognostic factors associated with the treatment efficacy of retrograde intrarenal surgery (RIRS) and develop a scoring system for predicting the stone-free rate after this surgery.

METHODS

We performed a retrospective analysis of 207 patients who underwent RIRS for renal stones between January 2009 and September 2011. Patient age, gender, body mass index, stone size, stone side, stone location, stone composition, number of stones, lower pole infundibulopelvic angle, using anticoagulant therapy, abnormal skeletal anatomy, and abnormal renal anatomy were investigated as potential preoperative predictive factors.

RESULTS

The present study included 111 (53.6%) men and 96 (46.4%) women. Mean patient age was 32.9 ± 18.8 years (range 1-74) and mean stone size was 16.2 ± 4.1 mm (range 8-40). Overall, 178 of the 207 (86%) patients were stone free after the initial treatment. Univariate analysis showed that stone size (P <.001), stone location (P = .025), stone composition (P = .01), stone number (P = .049), renal malformations (P = .042), and lower pole infundibulopelvic angle (P = .003) had significant influence on the stone-free rate after RIRS. Multivariate analysis excluded stone location from the logistic regression model, whereas other factors maintained their statistically significant effect on success rate, indicating that they were independent predictors.

CONCLUSION

Our study demonstrated that stone size, stone number, stone composition, infundibulopelvic angle, and renal malformations are significant predictors of RIRS outcome. A scoring system based on these factors helps separate patients into outcome groups and facilitates treatment planning.

Ureteroscopic treatment of larger renal calculi (>2 cm)

Objectives

To evaluate the current status of ureteroscopic lithotripsy (UL) for treating renal calculi of >2 cm, as advances in flexible ureteroscope design, accessory instrumentation and lithotrites have revolutionised the treatment of urinary calculi. While previously reserved for ureteric and small renal calculi, UL has gained an increasing role in the selective management of larger renal stone burdens.

Methods

We searched the available databases, including PubMed, Google Scholar, and Scopus, for relevant reports in English, and the article bibliographies to identify additional relevant articles. Keywords included ureteroscopy, lithotripsy, renal calculi, and calculi >2 cm. Retrieved articles were reviewed to consider the number of patients, mean stone size, success rates, indications and complications.

Results

In all, nine studies (417 patients) were eligible for inclusion. After one, two or three procedures the mean (range) success rates were 68.2 (23–84)%, 87.1 (79–91)% and 94.4 (90.1–96.7)%, respectively. Overall, the success rate was >90% with a mean of 1.2–2.3 procedures per patient. The overall complication rate was 10.3%, including six (1.4%) intraoperative and 37 (8.9%) postoperative complications, most of which were minor. The most common indications for UL were a failed previous treatment (46%), comorbidities (18.2%), and technical and anatomical factors (12.3%).

Conclusions

UL is safe and effective for treating large renal calculi. While several procedures might be required for total stone clearance, UL should be considered a standard approach in the urologist’s options treating renal calculi of >2 cm.

Retrograde intrarenal surgery in patients with spinal deformities

PURPOSE

To present our experience with retrograde intrarenal surgery (RIRS) for managing renal stones in patients with spinal deformities.

PATIENTS AND METHODS

We retrospectively reviewed the records of eight patients with congenital scoliosis (n=6), ankylosing spondylitis (n=1), or spina bifida (n=1) who had undergone RIRS for renal stones. Stone-free status was determined by CT 30 days after the procedure and was defined as the absence of stones in the kidney or residual fragments ≤ 1 mm.

RESULTS

Mean patient age was 32.5 years (8-51 years), and mean stone size was 15.8 mm (9-20 mm). The average operative time was 46.5 minutes (25-75 min), and postoperative hospital stay was 1.12 days (1-2 days). A stone-free status was obtained in six (75%) patients, and two patients were considered to have treatment failure. A Double-J stent was placed at the end of the procedure in five (62.5%) patients. Double- J stent discomfort was reported by one (20%) patient who was treated conservatively. No severe complications, either from anesthesia or the surgical procedure, were observed, and no blood transfusion was reported.

CONCLUSIONS

The good clearance rate with a low incidence of complications shown by the present study has demonstrated that RIRS is a safe and effective procedure for renal stones in patients with spinal deformities.

Successful outcome of flexible ureteroscopy with holmium laser lithotripsy for renal stones 2 cm or greater

Although percutaneous nephrolithotomy has been recommended as the first-line treatment for renal stones larger than 2 cm, its major complication rate is not negligible and less invasive approaches are to be explored. Thanks to the recent advances in endoscopic technology, flexible ureteroscopy has become another option in this setting. Herein we report our most recent experience with flexible ureteroscopy for large renal stones. Between September 2008 and May 2011, 20 patients with renal stones ≥ 2 cm underwent a total of 28 procedures of ureteroscopy with holmium laser lithotripsy, using the Olympus URF-P5 and a ureteral access sheath. The number of procedures, operative time, stone-free rates, stone compositions and complications were evaluated. Stone-free status was defined as the absence of fragments or fragments of ≤ 4 mm. Mean stone size was 3.1 cm (range 2.0-5.0). The average number of procedures was 1.4. One, two and three procedures were required in 13, six and one patients, respectively. Overall, the stone-free rate was 90%. The stone-free rate for preoperative stone size of 2 to ≤ 4 cm and >4 cm was 100% (14/14) and 67% (4/6), respectively. No major intraoperative complications were identified. Postoperative high-grade fever was observed in three patients, including one patient who developed sepsis. All these patients were successfully treated conservatively. Our findings suggest that ureteroscopy represents a favorable option for selected patients with renal stones, especially those 2 to ≤ 4 cm in size.

Ureteroscopic retrograde intrarenal surgery after previous open renal stone surgery: initial experience

The management of renal calculi following previous open surgery represents a challenge for urologists. The aim of this study is to evaluate the outcomes and safety of ureteroscopic laser retrograde intrarenal surgery (RIRS) for renal calculi following prior open renal surgery. The charts of 53 patients who underwent RIRS for renal calculi following prior open surgery for urolithiasis were reviewed. Both flexible and semi-rigid ureteroscopes were utilized together with holmium: YAG laser for stone disintegration. Intravenous urography, computed tomography (CT) and ultrasound were used to evaluate the patient, perioperatively. Stone size ranged from 5 to 32 mm (mean 14.3 mm). The mean operative time was 86 min (20-130). The overall stone-free rate was 92.4%. The overall stone-free rates after one and two-procedures were 79.2% (42 cases) and 92.4% (49 cases), respectively. Four patients (7.5%) had larger residual fragments, 2 (3.8%) of them underwent SWL, and 2 (3.8%) cases were followed up conservatively. Major complications were reported in two patients (3.8%). Stone analysis revealed calcium oxalate in 39 patients, uric acid in 5, calcium phosphate in 4, struvite in 3, and cystine in 2 cases. Ureteroscopic retrograde intrarenal surgery for renal calculi following prior open renal surgery was a minimally invasive, safe procedure with a high success rate. It is a viable alternative for PNL in managing recurrent renal calculi efficiently.

Safe and effective obtainment of access for percutaneous nephrolithotomy by urologists: the Louisiana State University experience

BACKGROUND AND PURPOSE

Access for percutaneous nephrolithotomy (PCNL) is critical to successful removal of stone burden and is often performed by a specialist other than a urologist. In many regions, however, there is limited availability of such personnel. We reviewed the complication rates that were related to PCNL access when performed at a teaching hospital to establish that access for PCNL may be safely taught to and performed by urology residents. Chief urology residents across the nation were also anonymously surveyed to better understand the current trends and dynamics regarding PCNL access in teaching institutions.

PATIENTS AND METHODS

A retrospective chart review was performed of all PCNLs performed at our institution from 1995 to 2009 for any complications that were related to surgery. Patients with access gained at outside institutions or not attempted at the time of surgery by residents were excluded. The complication rate was compared with those of the American College of Radiology. An eight-question survey was also sent by e-mail to all current urology chief residents regarding their experience with PCNL access during residency.

RESULTS

A total of 290 patients underwent PCNL with 338 separate access sites gained at the time of surgery under the supervision of nine teaching staff. Access was gained in all cases at the time of surgery. Major complications included: Transfusion in 20 (5.9%) patients, sepsis in 2 (0.6%) patients, pseudoaneurysm necessitating intervention in 2 (0.6%) patients, hydrothorax in 2 (0.6%) patients, pneuomothorax in 1 (0.3%) patient, ureteropelvic junction disruption in 1 (0.3%) patient, and one death (0.3%) after surgery. Minor complications included: Urinary tract infection in five (1.5%) patients, and collecting system injuries in 6 (1.8%) patients necessitating placement of a ureteral stent. Our survey of residents demonstrated that 53% did not routinely gain access for PCNL at their institution. The 94% who did not get instruction on PCNL access, however, thought it would be a valuable addition to their training.

CONCLUSION

Our results show that access for PCNL surgery can be safely and successfully obtained by genitourinary residents under the supervision of trained staff at the time of surgery. We think that access for PCNL is a valuable tool that should be in the armamentarium of all urologic surgeons on leaving an accredited urology training program.

Quantification of urinary stone volume: attenuation threshold-based CT method--a technical note

PURPOSE

To compare two threshold-based computed tomographic (CT) methods for the quantification of urinary stone volume; to assess their accuracy and precision at varying tube voltages, tube currents, and section thicknesses in a phantom; and to determine interobserver agreement with each of these methods in a pilot clinical study.

MATERIALS AND METHODS

After institutional review board approval, written informed consent was waived. The study was HIPAA compliant. Thirty-six calcium oxalate stones were scanned in an anthropomorphic phantom. For the fixed threshold method, stones were segmented with 0.6-mm-thick sections by using attenuation thresholds of 130 and 575 HU (equal to half of mean attenuation of all stones). For the variable threshold method, stones were segmented at an attenuation threshold equal to half of the attenuation of each stone and at variable section thicknesses (0.6, 1, and 3 mm), tube currents (150, 100, and 50 mAs [reference]), and tube voltages (100 and 80 kVp). Normalized Bland-Altman analysis was used to assess the bias and precision of the two CT methods compared with that of the fluid displacement method (reference standard). Two independent readers retrospectively measured stone volumes in 17 patients (male-to-female ratio, 1.4; mean age, 55 years), and interobserver agreement was assessed by using Bland-Altman limits of agreement.

RESULTS

The variable threshold method was more accurate and precise than the fixed threshold method with an attenuation threshold of 130 HU (P < .0001). Thinner sections (0.6 and 1 mm) resulted in more accurate (P < .05) and precise (P < .0001) stone volume measurements than 3-mm-thick sections. With the variable threshold method, no significant difference was seen in the accuracy and precision of stone volume measurements at various tube currents and tube potentials. Interobserver agreement was high with the fixed and variable threshold methods (r > 0.97).

CONCLUSION

An attenuation threshold-based CT method can be used to quantify urinary stone volume even at low radiation doses. The most accurate and precise method utilizes variable attenuation derived from the attenuation of each stone and thin sections.

Retrograde ureteroscopic intrarenal surgery for large (1.6-3.5 cm) upper ureteric/renal calculus

Objective:

To assess the feasibility of retrograde ureteroscopic intrarenal surgery (RIRS) as a viable alternate to percutaneous nephrostolithotripsy (PCNL) in treating patients with renal and upper ureteric calculus of 1.6 cm to 3.5 cm stone burden.

Materials and Methods:

From October 2007 to November 2008, a total of 30 cases of upper ureteric and renal stone of 1.6 cm to 3.5 cm (Average size 2.5 cm) stone burden, for which PCNL would be done otherwise, were treated by RIRS with combined flexible and semi rigid ureteroscope and stones fragmented with holmium laser. The patients were discharged after 24 hours of the procedure and allowed to resume normal work after two days. X ray KUB for radio opaque stones and ultrasound for all the cases were done after three weeks and if any residual fragments of any size were present the patient was taken up for re-look flexible ureteroscopy under anesthesia. Stent and residual fragments were removed. If there was no residue the stent was removed under local anesthesia.

Results:

Complete clearance was considered if there were no fragments on USG screening after three weeks. Twenty six (86.6%) patients out of 30 had complete clearance in the first sitting and 4 (13.3%) patients needed re-look flexible ureteroscopy. The stone free rate in RIRS is 86.6% in the first sitting and 100% at second sitting.

Conclusion:

RIRS is superior in terms of less complication, less morbidity and good stone free rate and has an advantage of one day of hospital stay and resuming duties after two days. RIRS is the best option for managing extracorporeal shockwave lithotripsy failed and post PCNL residual calculus. RIRS is definitely a viable alternate for PCNL for upper tract stones up to 3.5 cm.

Flexible ureterorenoscopy and holmium laser lithotripsy for the management of renal stone burdens that measure 2 to 3 cm: a multi-institutional experience

BACKGROUND AND PURPOSE

Percutaneous nephrostolithotomy (PCNL) is the current standard of care for management of large renal stones (>2 cm). Recent studies have evaluated flexible ureterorenoscopy (URS)/holmium laser lithotripsy as an alternative treatment for patients with contraindications to or preference against PCNL. Stones in an intermediate size range (2-3 cm) may be most amenable to URS/laser lithotripsy as definitive treatment in a single stage. We report a multi-institutional series of URS/laser lithotripsy for renal stone burdens that measure 2 to 3 cm.

PATIENTS AND METHODS

Patients who underwent URS/holmium laser lithotripsy for renal stones that measured 2 to 3 cm were identified retrospectively at three tertiary care centers. Demographic information, disease characteristics, and perioperative and postoperative data were gathered. Patients with renal stone burdens of 2 to 3 cm who were treated by URS/laser lithotripsy and had at least one postoperative visit and imaging study were included. Stone clearance was evaluated using 0-2 mm and <4 mm residual stone burden on postoperative imaging.

RESULTS

One hundred and twenty patients underwent URS/holmium laser lithotripsy for renal stones of 2 to 3 cm. Mean stone burden was 2.4 cm, and mean body mass index was 29.3 kg/m². Indications for URS/laser lithotripsy vs PCNL included patient preference (57), technical or anatomic factors (24), patient comorbidities (17), failed shockwave lithotripsy (9), patient body habitus (3), solitary kidney (3), chronic renal insufficiency (3), and strict anticoagulation (2). Thirty-one (26%) patients had stent placement preprocedure, and 94 (78%) patients underwent outpatient surgery. A ureteral access sheath was used in 67%. One hundred and one (84%) patients underwent single-stage procedures. There was one intraoperative complication (ureteral perforation), and there were eight minor postoperative complications (6.7%). The reoperation rate through the mean 18-month follow-up was 3/120 or 2.5%. Seventy-six (63%) patients had residual stone burden of 0 to 2 mm, and 100 (83%) patients had residual burden of <4 mm.

CONCLUSIONS

We demonstrate that single-stage URS/holmium laser lithotripsy is effective for management of renal stones that measure 2 to 3 cm through intermediate follow-up. Staged procedures can be used selectively for technical reasons or disease factors. Although PCNL achieves superior stone clearance overall, URS/laser lithotripsy is a viable treatment option for selected patients.

Efficacy and safety of laser lithotripsy in fragmentation of urocystoliths and urethroliths for removal in dogs

OBJECTIVE

To characterize the efficacy and safety of laser lithotripsy in the fragmentation of urocystoliths and urethroliths for removal in dogs.

DESIGN

Prospective case series.

ANIMALS

100 dogs with naturally occurring urocystoliths and urethroliths.

PROCEDURES

Via cystoscopy, laser lithotripsy was performed to fragment uroliths. Basket retrieval and voiding urohydropropulsion were used to remove fragments. Postprocedural contrast cystography was performed to assess efficacy and safety. In 40 dogs, midstream urine samples were collected just prior to laser lithotripsy (day 0) and on days 1, 3, and 11 after laser lithotripsy to assess inflammation.

RESULTS

Urolith removal was complete in 82% of dogs (52/66 with only urocystoliths, 17/17 with only urethroliths, and 13/17 with urocystoliths and urethroliths). Urolith removal was incomplete in 18 dogs; of these dogs, 9, 6, and 3 had urolith fragments >or= 3 mm, 1 to < 3 mm, and < 1 mm in diameter, respectively. Sex (female) was the most significant predictor for success. Median procedure time was 72 minutes. Two dogs developed urinary tract obstruction following laser lithotripsy. Hematuria was detected in 53% of dogs on day 0 and in 84%, 13%, and 3% of dogs on days 1, 3, and 11, respectively. Leukocyturia was detected in 13% of dogs on day 0 and in 47%, 0%, and 3% of dogs on days 1, 3, and 11, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that use of laser lithotripsy was a safe and effective alternative to surgical removal of urocystoliths and urethroliths in dogs.

Percutaneous nephrostolithotomy versus flexible ureteroscopy/holmium laser lithotripsy: cost and outcome analysis

PURPOSE

While percutaneous nephrostolithotomy is the standard of care for renal stones greater than 2 cm, recent studies have shown that staged ureteroscopy/holmium laser lithotripsy may be a reasonable option. Stones 2 to 3 cm may be amenable to ureteroscopy as well as to 1-stage treatment based on their intermediate size. We compared clinical outcomes and the estimated cost of percutaneous nephrostolithotomy vs ureteroscopy for 2 to 3 cm renal stones.

MATERIALS AND METHODS

We retrospectively identified patients who underwent percutaneous nephrostolithotomy and ureteroscopy at our institution from 2004 to 2008 with a maximal renal stone diameter of 2 to 3 cm. Demographic information, disease characteristics, intraoperative and postoperative data, and complications were recorded. Stone clearance was reported as a residual stone burden of 0 to 2 mm and less than 4 mm. Cost was estimated using local Medicare reimbursements for surgeon, anesthesia, hospital and outpatient services.

RESULTS

A total of 20 patients underwent percutaneous nephrostolithotomy and 19 underwent ureteroscopy for 2 to 3 cm renal stones. The estimated cost of percutaneous nephrostolithotomy was significantly greater than that of ureteroscopy ($19,845 vs $6,675, p <0.0001). There were significantly more second stage procedures among percutaneous nephrostolithotomy cases (11 vs 1, p = 0.003). Stone clearance (0 to 2 mm) was superior for percutaneous nephrostolithotomy vs ureteroscopy (89% vs 47%, p = 0.01). Using a less than 4 mm threshold stone clearance improved to 100% vs 95% (p not significant). Two patients (10.5%) with ureteroscopy required subsequent ipsilateral stone surgery. They were noncompliant with medical/dietary therapy or radiographic surveillance.

CONCLUSIONS

While percutaneous nephrostolithotomy achieves superior stone clearance, ureteroscopy achieves acceptable treatment outcomes with a low risk of subsequent stone related events or interventions. The lower relative cost of ureteroscopy in this population may have implications for the development of treatment guidelines.

What is the Role of Retrograde Ureteroscopy in the Management of Large Renal Calculi?

Background and purpose:

The management of large renal calculi has traditionally been with percutaneous nephrolithotomy (PCNL) or occasionally extracorporeal shock wave lithotripsy (ESWL). We present our experience of ureteroscopic treatment of large renal calculi in patients where PCNL/ESWL were contraindicated, refused or failed.

Patients and methods:

Data from 30 patients with intra-renal calculi ≥20 mm was prospectively entered onto a database and analysed. Patients were treated with rigid and flexible ureteroscopy (URS) using holmium laser or lithoclast (pneumatic) lithotripsy.

Results:

Mean stone size was 2.8cm (range 2.0–6.0cm). The most common indications were ESWL failure (40%), anatomical reasons (20%), patient choice (10%) and failed PCNL access (7%). Stone clearance (no fragments >3 mm on follow-up imaging) was observed after one URS treatment alone in 30% of patients and a further 27% with a post-operative session of ESWL. Two URS sessions alone were used in 23% of patients, with a single patient needing two URS and post-operative ESWL. Three URS sessions plus ESWL was used in 7% of patients. Three patients (10%) required PCNL. Median operative time was 60min. Complications were minimal: four patients had urinary tract infection, one failed trial without catheter, one atrial fibrillation, and one stent migration.

Conclusion:

Where PCNL is not favoured for any reason, patients with a large stone burden can be safely and effectively managed with retrograde URS, either with the intention of stone clearance or de-bulking prior to ESWL.