Nephrolithiasis: "Scope," Shock or Scalpel?

Decision-making and improvements in health-related quality of life in patients with kidney stones: comparing surgery versus observation using a mixed methods analysis

The experience of patients who choose observation or surgery for kidney stones has not been well established. We compared these patients using qualitative interviews, the Wisconsin Quality of Life questionnaire (WISQOL), and the Cambridge Renal Stone Patient Reported Outcome Measure (CReSP). Adult patients with upper tract urinary calculi for whom observation or intervention were options underwent qualitative interviews at baseline and at 2 months. WISQOL and CReSP were administered at baseline, and at 6–16 weeks post operatively if surgery was selected. Comparisons in patient experiences and quality of life measures were performed between groups. Among 15 patients who opted for surgery and 10 patients who opted for observation, we identified major themes in patient experiences related to context, health care episodes, patient responses, and perceived outcomes. A conceptual framework for the domains of patient experience during kidney stone disease was developed, which can be used by clinicians and patients to shape discussion. Baseline standardized WISQOL and CReSP scores were comparable between groups. In the surgery group, both WISQOL and CReSP scores improved after surgery (WISQOL 58 to 83, higher is better, p = 0.003; CReSP 31 to 23, lower is better, p = 0.009). Patients who underwent surgery for kidney stones reported improvements in quality of life after treatment via WISQOL and CReSP. A conceptual framework was developed for the patient experience of kidney stones which provides a common language for patients and clinicians.

A prospective, multi-institutional study of flexible ureteroscopy for proximal ureteral stones smaller than 2 cm

PURPOSE

Flexible ureteroscopy is rapidly becoming a first line therapy for many patients with renal and ureteral stones. However, current understanding of treatment outcomes in patients with isolated proximal ureteral stones is limited. Therefore, we performed a prospective, multi-institutional study of ureteroscopic management of proximal ureteral stones smaller than 2 cm to better define clinical outcomes associated with this approach.

MATERIALS AND METHODS

Adult patients with proximal ureteral calculi smaller than 2 cm were prospectively identified. Patients with concomitant ipsilateral renal calculi or prior ureteral stenting were excluded from study. Flexible ureteroscopy, holmium laser lithotripsy and ureteral stent placement was performed. Ureteral access sheath use, laser settings and other details of perioperative and postoperative management were based on individual surgeon preference. Stone clearance was determined by the results of renal ultrasound and plain x-ray of the kidneys, ureters and bladder 4 to 6 weeks postoperatively.

RESULTS

Of 71 patients 44 (62%) were male and 27 (38%) were female. Mean age was 48.2 years. ASA(®) score was 1 in 12 cases (16%), 2 in 41 (58%), 3 in 16 (23%) and 4 in 2 (3%). Mean body mass index was 31.8 kg/m(2), mean stone size was 7.4 mm (range 5 to 15) and mean operative time was 60.3 minutes (range 15 to 148). Intraoperative complications occurred in 2 patients (2.8%), including mild ureteral trauma. Postoperative complications developed in 6 patients (8.7%), including urinary tract infection in 3, urinary retention in 2 and flash pulmonary edema in 1. The stone-free rate was 95% and for stones smaller than 1 cm it was 100%.

CONCLUSIONS

Flexible ureteroscopy is associated with excellent clinical outcomes and acceptable morbidity when applied to patients with proximal ureteral stones smaller than 2 cm.

Percutaneous nephrolithotomy for 1-2 cm lower-pole renal calculi

Objectives:

The most appropriate management of patients with lower-pole calyceal (LC) stones remains controversial. In this review we discuss the role of percutaneous nephrolithotomy (PCNL) in the management of LC stones 1–2 cm in maximum dimension.

Materials and Methods:

A detailed literature review was performed to summarize the recent technical developments and controversies in PCNL. The results of PCNL for 1-2 cm LC calculi were reviewed.

Results:

PCNL is increasingly employed as a primary modality in the treatment of LC calculi. It has a high success rate and acceptably low percentage of major complications in experienced hands. Supine position is found to be as safe and effective as prone position. Urologist-acquired access is associated with fewer access-related complications and better stone-free rates. Ultrasound is increasingly employed as an imaging modality for obtaining access. There have been increasing reports of tubeless PCNL in the literature. Most patients undergoing tubeless PCNL do not need hemostatic agents as an adjuvant for hemostasis. Non-contrast computed tomography does not yield statistically valuable increase in the diagnosis of significant residual stones compared with that of plain X-ray and linear tomography. Comprehensive metabolic evaluation and aggressive medical management can control new stone recurrences and growth of residual fragments following PCNL.

Conclusions:

PCNL is a highly effective procedure with consistently high stone-free rates when compared with extracorporeal shockwave lithotripsy or retrograde intrarenal surgery. The results also do not depend on anatomic factors and stone size. It is associated with low morbidity in experienced hands.

A comparison of treatment modalities for renal calculi between 100 and 300 mm2: are shockwave lithotripsy, ureteroscopy, and percutaneous nephrolithotomy equivalent?

BACKGROUND AND PURPOSE

Shockwave lithotripsy (SWL) is considered a standard treatment for patients with upper-tract stones that are less than 10 mm in diameter, whereas stones that are larger than 20 mm are best managed by percutaneous nephrolithotomy (PCNL). The management of stones between these sizes remains controversial. Our purpose was to review our contemporary series of SWL, ureteroscopy (URS), and PCNL outcomes for intermediate-sized upper tract calculi (100-300 mm(2)).

PATIENTS AND METHODS

Analysis was restricted to those patients who were treated for a renal calculus that measured between 100 and 300 mm(2) during a 4-year span. Demographic, stone, patient, treatment, and follow-up data were collected from a prospectively maintained database.

RESULTS

A total of 137 patients were referred with nonstaghorn calculi with an area between 100 and 300 mm(2). Fifty-three (38.7%) patients were treated with SWL, while 41 (29.9%) and 43 (31.4%) underwent ureteroscopy and PCNL, respectively. Mean stone area was higher in the PCNL group (P < 0.001), whereas stone density was higher for patients undergoing SWL (P = 0.002). Single treatment success rates were better for PCNL at 95.3%,vs 87.8% for ureteroscopy and 60.4% for SWL, P < 0.001. When allowing for two SWL treatments, the success rate improved to 79.2%, thus equalizing the success of the three treatment modalities (P = 0.66). Auxiliary treatments were more common after SWL (42.3%; P < 0.01).

CONCLUSIONS

For intermediate-sized upper-tract stones, when allowing for up to two SWL treatments, there was no significant difference between treatment modalities. Thus, SWL is a reasonably successful treatment alternative for patients who are not fit for a general anesthetic or who prefer SWL over competing treatments, provided they accept a potentially higher number of treatments.

Lithotripsy

Shock wave lithotripsy (SWL) is the process of fragmentation of renal or ureteric stones by the use of repetitive shock waves generated outside the body and focused onto the stone. Following its introduction in 1980, SWL revolutionized the treatment of kidney stones by offering patients a non-invasive procedure. It is now seen as a mature technology and its use is perceived to be routine. It is noteworthy that, at the time of its introduction, there was a great effort to discover the mechanism(s) by which it works, and the type of sound field that is optimal. Although nearly three decades of subsequent research have increased the knowledge base significantly, the mechanisms are still controversial. Furthermore there is a growing body of evidence that SWL results in injury to the kidney which may have long-term side effects, such as new onset hypertension, although again there is much controversy within the field. Currently, use of lithotripsy is waning, particularly with the advent of minimally invasive ureteroscopic approaches. The goal here is to review the state of the art in SWL and to present the barriers and challenges that need to be addressed for SWL to deliver on its initial promise of a safe, effective, non-invasive treatment for kidney stones.

Contemporary surgical management of upper urinary tract calculi

PURPOSE

Upper urinary tract calculi are treated with multiple technologies including shock wave lithotripsy, ureteroscopy and percutaneous nephrolithotomy. Our knowledge of surgical practice patterns in the treatment of these calculi is limited. We performed a study of the surgical practice logs submitted to the American Board of Urology by candidates for initial certification and recertification to characterize the manner in which renal and ureteral calculi are treated.

MATERIALS AND METHODS

Logs from initial certification, first recertification and second recertification cohorts were reviewed. CPT codes were used as search criteria, and included 50590 (shock wave lithotripsy), 52352 (ureteroscopy, stone removal), 52353 (ureteroscopy, lithotripsy), 50080 (percutaneous nephrolithotomy for stones less than 2 cm) and 50081 (percutaneous nephrolithotomy for stones greater than 2 cm).

RESULTS

For the initial certification cohort surgical logs from 2004 to 2008 were reviewed and 1,065 individuals were identified. For the 2 recertification cohorts logs from 2003 to 2007 were reviewed, with 1,120 individuals identified in the first recertification cohort, and 831 identified in the second recertification cohort. Candidates for initial certification used ureteroscopy in the majority of stone removal procedures (52.0%), and candidates for first and second recertification used shock wave lithotripsy in the majority of their procedures (57.4% and 60.5%, respectively). There was a decreasing use of percutaneous nephrolithotomy across the cohorts with 6.8% in the initial, 4.5% in the first and 2.6% in the second recertification cohort.

CONCLUSIONS

Provider specific attributes may affect how upper tract calculi are treated. Urologists in the initial certification cohort claimed the greatest use of endoscopic treatment modalities and most commonly performed ureteroscopy. Shock wave lithotripsy was more commonly used by the 2 recertification cohorts, comprised of more senior urologists.

Infarction of middle third posterior cortex of kidney: a complication of extended pyelolithotomy, intra-operative electrohydraulic lithotripsy and extraction of calyceal stones under vision using stone basket and flexible cystoscope in a spinal cord injury patient - a case report

BACKGROUND

Spinal cord injury produces multiple systemic and metabolic alterations. A decrease in micro vascular blood flow to liver, spleen and muscle has been described following spinal cord injury.

CASE PRESENTATION

We present a 46-year-old male patient with C-4 complete tetraplegia, who developed a large stag horn calculus with branches in upper, middle and lower calyces of left kidney. This patient underwent Gil-Vernet extended pyelolithotomy and required intra-operative electrohydraulic lithotripsy and retrieval of stones from upper, middle and lower calyces using flexible cystoscope and stone basket. Computed tomography, performed eighteen days after surgery, showed multiple areas of non-enhancing cortex posteriorly and in the upper pole, suggestive of focal infarction. Magnetic resonance imaging of left kidney confirmed the presence of an area of infarction in middle third of posterior cortex, but there was no evidence of trauma to posterior division of renal artery. Therefore, we postulate that compression of renal parenchyma by Gil-Vernet retractors during surgery, and firm pressure that was applied over the middle of kidney for prolonged periods while several attempts were being made to retrieve fragments of calculi from renal calyces, led to ischaemia and subsequently, infarction of mid-third posterior cortex of left kidney.

CONCLUSION

This case illustrates importance of gentle handling of kidney during extended pyelolithotomy in order to prevent subtle renal trauma, which may be detected only by advanced imaging studies. Further, spinal cord physicians should take a pragmatic approach to management of stones located inside renal calyces. Both spinal cord injury patients and their physicians should remember that in our enthusiasm to achieve complete clearance of stones embedded deeply within renal calyces, we could produce irreversible injury to kidney, as indeed happened in this patient. Therefore, emphasis should be placed on prevention of struvite renal calculi by discarding indwelling urinary catheters and eliminating Proteus bacteriuria.

Eighteen-year experience with the Medstone STS lithotripter: safety, efficacy, and evolving practice patterns

OBJECTIVE

To evaluate trends in safety, efficacy, and practice patterns for shockwave lithotripsy (SWL) procedures performed during a 18-year period and correlate the findings with recent evidence-based practice guidelines.

MATERIALS AND METHODS

From January 1988 to June 2006, 66,819 SWLs were performed using the Medstone STS lithotripter in patients with radiologic evidence of stones in the kidney or ureter. Treatment characteristics, such as stone location and size, need of re-treatment, and final success rate were recorded. The procedures were further divided by year for statistical consideration. Statistical analysis was performed using Student t test; P < 0.05 was considered significant.

RESULTS

Overall SWL success rate was 85% (39,667/46,669), and the overall re-treatment rate was 7.2% (3,417/46,669). There was no significant change in the overall proportion of lower-pole calculi managed with SWL, although there was a significant decrease in the proportion of SWL used for lower calix stones larger than 16 mm in the time period after 2000 (P = 0.006). There was a steady increase in the number of procedures performed for renal calculi in other locations per year, in particular for intrarenal calculi smaller than 20 mm. Intrarenal stones larger than 30 mm decreased as a proportion of procedures per year (P = 0.048) There was no significant change in the proportion of upper and distal ureteral stones managed, corresponding to a solid plateau in the percentage of SWL performed per year.

CONCLUSION

Our study did not demonstrate an overall drop in SWL; however, it did show the interference of endoscopic procedures on two case scenarios. There was a significant decrease (P = 0.048) in SWL for renal stones larger than 30 mm, and the same trend was noted for lower calix stones larger than 15 mm (P = 0.06).

Extending the application of tubeless percutaneous nephrolithotomy

OBJECTIVES

Tubeless percutaneous nephrolithotomy (PCNL) has been successfully performed in selected patients. We assessed its applicability for use without imposing preoperative restrictions.

METHODS

The study consisted of a prospective and consecutive series of 126 patients. Tubeless PCNL was performed when perforation, residual stones, and significant bleeding had been intraoperatively excluded by fluoroscopy, nephroscopy, and hemodynamic assessment. Staghorn stones, supracostal and/or multiple access, anatomic anomalies, previously operated kidneys, solitary kidneys, and operative time were not considered contraindications. The demographic, clinical, and intraoperative and postoperative data were statistically analyzed.

RESULTS

Using this protocol, we performed 66 (52%) tubeless and 60 (48%) regular PCNLs. The average patient age (54 years versus 52 years), stone burden (924 versus 1044 mm2), operative time (116 versus 130 minutes), complication rate (9% versus 13%), hemoglobin decrease (1.2 versus 1.1 mg/dL), and immediate stone-free rate (92% versus 90%) were similar for the tubeless and regular PCNL groups, respectively (P >0.05). The reasons for performing standard PCNL were an expected second-look procedure (n = 35, 58%), an impression of active bleeding (n = 16, 27%), significant extravasation (n = 5, 8%), and suspected hydrothorax (n = 4, 7%). The overall transfusion rate was 3%. The average analgesia requirement (pethidine HCL) was 0.4 and 1.2 mg/kg (P <0.01), the median hospital stay was 1 and 4 days (P <0.0001), and the median back-to-work time was 7 and 15 days (P <0.001) for the tubeless and regular PCNL groups, respectively.

CONCLUSIONS

The results of our study have shown that tubeless PCNL can be safely and effectively performed based on intraoperative factors, without preoperative contraindications. Compared with the standard procedure, tubeless PCNL was associated with reduced postoperative pain, hospital stay, and recovery time.

Pre- and perioperative predictors of short-term clinical outcomes in patients undergoing percutaneous nephrolitholapaxy

Percutaneous nephrolitholapaxy (PCNL) with modern stone disintegration technologies is the treatment of choice for patients with extensive stone burden or stones refractory to extracorporeal shock wave lithotripsy. However, little is known about factors predicting unfavourable outcome in terms of perioperative complications, residual stone burden or prolonged hospitalization. The aim of this study was to evaluate preoperative, patient- and stone-related parameters that might influence the perioperative course and short-term clinical outcomes. In a prospective study, age, sex, body mass index (BMI), bidimensional size, side, pre-existent urinary tract infection, pre-existent hydronephrosis and previous kidney surgery were used as independent variables in both univariate and multiple regression models in 109 PCNL patients in order to predict the partition of patients rendered stone free at hospital discharge, duration of surgery, length of inpatient hospital stay and the occurrence of major complications. Univariate and multiple regression analysis revealed that stone size was the only factor influencing duration of surgery (P < 0.001) and hospitalization (P = 0.02), but had no predictive potential for major complications. Univariate analysis showed a trend towards longer inpatient hospital stay and clinically relevant residuals in patients with lower BMI (P = 0.05 and 0.06); however, after controlling for the other confounding variables, this was only reproducible for residual stone burden. The other patient- and stone-related factors did not adversely affect the outcome measures. In our patient sample treated with PCNL by LithoClast Master/Ultra we found evidence that large stone burden is a prognostic factor predicting longer surgery and prolonged hospitalization. In addition, patients with lower BMIs might be at higher risk of not being stone free at hospital discharge accompanied by prolonged inpatient treatment.

Is there still a role for open surgery in the management of renal stones?

PURPOSE OF REVIEW

In the last few decades, with the improvement in endourological surgery and the invention and evolution of extracorporeal shock-wave lithotripsy, the indications for open surgery in stone disease have become rare, although open surgery still has a role in selected cases. In this review we discuss the current indications of open surgery for the elimination of urinary calculi.

RECENT FINDINGS

A MEDLINE and MeSH search was performed to evaluate currently available guidelines on open stone surgery and identify the evidence-based medicine that support the role of open surgery in treating urinary lithiasis. The latest papers published on open stone surgery are reviewed and conclusions are drawn, based on their results.

SUMMARY

Open stone surgery should be avoided in most cases, but should be considered for those patients in whom a reasonable number of less invasive procedures would not be useful. The most common indications for open stone surgery include complex stone burden, failure of extracorporeal shock-wave lithotripsy or endourological treatment and anatomical abnormalities (such as ureteropelvic junction obstruction and infundibular stenosis with or without renal caliceal diverticulum). The level of evidence for the currently available guidelines is not adequate, mainly because of lack of properly designed, large prospective randomized trials that compare different treatment options.