Staghorn renal stones: what the urologist needs to know

International Alliance of Urolithiasis (IAU) guideline on staghorn calculi management

BACKGROUND

The stone burden based management strategy reported in the guidelines published by different associations is well known for a long time. Staghorn calculi, representing the largest burden and most complex stones, is one of the most challenging cases to practicing urologists in clinical practice. The International Alliance of Urolithiasis (IAU) has released a series of guidelines on the management of urolithiasis.

PURPOSE

To develop a series of recommendations for the contemporary management management of staghorn calculi and to provide a clinical framework for urologists treating patients with these complex stones.

METHODS

A comprehensive literature search for articles published in English between 01/01/1976 and 31/12/2022 in the PubMed, OVID, Embase and Medline database is performed. A series of recommendations are developed and individually graded following the review of literature and panel discussion.

RESULTS

The definition, pathogenesis, pathophysiology, preoperative evaluation, intraoperative treatment strategies and procedural advice, early postoperative management, follow up and prevention of stone recurrence are summarized in the present document.

CONCLUSION

A series of recommendations regarding the management of staghorn calculi, along with related commentary and supporting documentation offered in the present guideline is intended to provide a clinical framework for the practicing urologists in the management of staghorn calculi.

Perioperative and long-term results of ultrasonography-guided single- and multiple-tract percutaneous nephrolithotomy for staghorn calculi

BACKGROUND

It is possible that this condition will lead to urosepsis and progressive deterioration of renal function in the absence of surgical intervention. Several recent clinical studies have shown that multi-tract percutaneous nephrolithotomy (M-PCNL) has a similar stone free rate (SFR) as standard percutaneous nephrolithotomy (S-PCNL). As a result, M-PCNL was also recommended as a treatment option for staghorn calculi.

AIM

To examine the perioperative and long-term results of ultrasonography-guided single- and M-PCNL.

METHODS

This was a retrospective cohort study. Between March 2021 and January 2022, the urology department of our hospital selected patients for the treatment of staghorn calculi using percutaneous nephrolithotomy. The primary outcomes were complication rate and SFR, and the characteristics of patients, operative parameters, laboratory measurements were also collected.

RESULTS

In total, 345 patients were enrolled in the study (186 in the S-PCNL group and 159 in the M-PCNL group). The SFR in the M-PCNL group was significantly higher than that in the S-PCNL group (P = 0.033). Moreover, the incidence rates of hydrothorax (P = 0.03) and postoperative infection (P = 0.012) were higher in the M-PCNL group than in the S-PCNL group. Logistic regression analysis demonstrated that post-operative white blood cell count (OR = 2.57, 95%CI: 1.90-3.47, P < 0.001) and stone size (OR = 1.59, 95%CI: 1.27-2.00, P < 0.001) were associated with a higher overall complication rate in the S-PCNL group. Body mass index (OR = 1.22, 95%CI: 1.06-1.40, P = 0.004) and stone size (OR = 1.70, 95%CI: 1.35-2.15, P < 0.001) were associated with increased overall complications in the M-PCNL group.

CONCLUSION

Multiple access tracts can facilitate higher SFR while slightly increasing the incidence of acceptable complications.

Urologists' opinion on treating asymptomatic stones: Would we treat ourselves as we treat our patients? Survey from European Association of Urology, Young Academic Urologists, Endourology and Urolithiasis working party

Background/aim

Management of asymptomatic kidney stones is an ongoing debate with follow-up and treatment guidelines based on low-level evidence. Our aim was to evaluate current management of asymptomatic urinary stones.

Materials and methods

A 70-question survey was designed in collaboration with European Association of Urology, Young Academic Urologists, Section of Uro-Technology and Section of Urolithiasis groups and distributed. Responders filled out hypothetical scenarios from 2 perspectives, either as treating physicians, or as patients themselves.

Results

A total of 212 (40.01%) responses were obtained. Median responder age was 39 years. 75% of responders were interested in "urolithiasis". 82.5% had never experienced a renal colic, 89.6% had never undergone urolithiasis treatment.Overall, as the kidney stone scenarios got more complicated, the invasiveness of the treatment preference increased. As "the physician", responders preferred the conservative option in all situations more than they would choose as "the patient". For ureteral stones, conservative approach was most preferred for small stones and ureteroscopy became more preferred as the stone size increased.For smaller kidney stones, the most preferred follow-up schedule was 4-6 monthly, whereas for larger and complicated stones it was 0-3 monthly from both perspectives respectively. For all ureteral stone scenarios, 0-4 weekly follow-up was mostly preferred.Interestingly, having had a renal colic was an independent predictor of an interventional approach, whereas having had an intervention was an independent predictor of a conservative approach.

Conclusion

Current treatment and follow-up patterns of asymptomatic urinary stones are in agreement with international guidelines on symptomatic stones.In most of the urolithiasis situations urologists chose a conservative approach for their patients compared to what they would prefer for themselves. Conversely, urologists, in the scenarios as "the patient", would like to have a more frequent follow-up schedule for their stones compared to how they would follow-up their patients.

Providencia alcalifaciens in a patient with a staghorn calculus: a novel presentation

A member of the Enterobacteriaceae family, Providencia alcalifaciens is typically recognized as a source of gastrointestinal illness. Although its pathogenicity is not well known, many studies have suggested its mechanism of action involves the invasion of the intestinal mucosal layer. Although P. alcalifaciens is a urease producing microorganism, it has not been associated with the formation of a staghorn calculus in the setting of a urinary tract infection. This organism is neither commonly pursued in research or investigation nor is it commonly tested for in the clinical setting. This is especially true when combined with other disease processes, such as calculus formation. The advancement of antibiotic resistance, such as carbapenemase-producing strains, should bring more attention and routine investigation to this organism in the acute stage of infection. In this case report we introduce a 43-year-old Cuban female, who presents with a left-sided staghorn calculi and urine culture positive for carbapenemase-producing P. alcalifaciens.

A huge staghorn renal stone: Is there still a need for open surgery to protect against further damage to the kidney? A case report

INTRODUCTION

Staghorn calculi (SC) occupy the renal pelvis and calyces and are common in females linked to repeated urinary tract infections (UTIs). Judicious surgery planning reduces the chance of further damage to the kidney due to renal SCs. Open stone surgery (OSS) is one of the various operative techniques to remove such huge stones with one operative intervention and protect the kidney from ongoing functional damage.

CASE REPORT

A 47-year-old male patient presented with right-sided renal colic pain, and on further investigations, he was diagnosed with a large renal stone responsible for substantial renal function impairment on the same side. The SC measured 8 × 4 cm with another stone in the lower calyx. thinner parenchyma, and only 16% relative function. Therefore, open surgery was selected over less invasive approaches because multiple lithotripsy (ESWL) sittings may have been required in less invasive options.

DISCUSSION

SCs, which can be complete or partial, often result in renal impairment. Hence, it is crucial to implement a proactive therapeutic approach that includes a thorough evaluation of the stone's size and position, the patient's choice, and institutional capacity. Complete elimination of SCs is preferred to maintain maximal renal function. Based on clinical, technical, and socioeconomic considerations, open pyelolithotomy or OSS was chosen over percutaneous nephrolithotomy for SC removal in the discussed case.

CONCLUSION

The ability to remove large stones in a single intervention with open pyelolithotomy has been very effective due to its distinctive clinical presentation and pathological abnormalities.

Infected calcium oxalate stone leading to pyogenic spondylodiscitis and bilateral lower limb weakness: a case report

Introduction and importance

It is rare for calcium oxalate renal stone, presented mainly in sterile urine, to result in urinary tract infection. The stone-related infection could develop spondylodiscitis, causing neurological deficits. To date, there are no reports about calcium oxalate partial staghorn stone and spondylodiscitis.

Case presentation

A 62-year-old male suffered from haematuria, fever, and flank pain. He came to the urology outpatient department, where acute pyelonephritis was diagnosed, and a left partial staghorn stone was seen on computed tomography. Oral antibiotics were prescribed with improvement. Two weeks after antibiotics treatment, he developed bilateral lower limb weakness and numbness under the nipple level. He was brought to the emergency department, where the spine MRI revealed T2-T3 spondylodiscitis with epidural abscess and spinal cord compression. He underwent T2-T3 spine operation with improvement in muscle power and hypesthesia. The culture of the surgical lesion yielded Citrobacter koseri, the same as the urine culture obtained at his first visit. Left-side percutaneous nephrolithotomy was performed 1 month after with successful stone removal and resolution of pyuria. Stone analyses reported calcium oxalate. Follow-up MRI showed marked improvement with resolution of spondylodiscitis.

Clinical discussion

Urinary tract infection resulting from partial staghorn stone, with additional hematogenous spread causing spondylodiscitis, is scarcely discussed. The authors illustrated a case with calcium oxalate stone, belonging to sterile Jensen's classification type 1. However, a urinary tract infection could be seen in urine stasis or obstruction.

Conclusion

With accurate diagnosis and essential interventions, the patient had immediate neurological improvement and reached disease-free status.

A novel nomogram and a simple scoring system for urinary leakage after percutaneous nephrolithotomy

Introduction:

The present study aimed to investigate the factors of prolonged urinary leakage (PUL) after percutaneous nephrolithotomy (PCNL) and develop a new and simple scoring system to predict it.

Patients and Methods:

We retrospectively reviewed patients with renal stones who underwent PCNL at the University of Health Sciences Izmir Bozyaka Training and Research Hospital between April 2011 and January 2020. The patients were divided into two groups according to the presence of PUL, and their preoperative and perioperative data were compared. A multivariate regression analysis was applied to examine the relationship between perioperative descriptors and PUL, and a nomogram was developed using significant predictors. Then, the individual components of the nomogram were assigned points to form a scoring system.

Results:

There were 92 and 840 patients in the groups with and without PUL, respectively. The results of the univariate logistic regression analysis showed that hydronephrosis grade, parenchymal thickness, duration of nephroscopy, and duration of nephrostomy catheter were significantly associated with PUL. Subsequently, a multivariate regression analysis was carried out with these four factors as possible independent risk factors of PUL after PCNL. Based on the results of this analysis, a nomogram prediction model was developed with an area under the curve value of 0.811, which was consequently used to develop a new simple score system consisting of three characteristics: parenchymal thickness (1–5 points), duration of nephroscopy (1–3 points), and hydronephrosis grade (1–3 points).

Conclusion:

A novel scoring system is a useful tool for predicting PUL in patients who have undergone percutaneous nephrolithotomy.

Open surgery versus percutaneous nephrolithotomy for management of staghorn calculi

BACKGROUND

For urologists, treating staghorn stones remains a difficult challenge. Various studies have evaluated the results of percutaneous nephrolithotomy (PCNL) and open surgery in different populations but these results were controversial. Here, we aimed to compare and evaluate the results of open surgery and PCNL in the treatment of staghorn stones.

METHODS

This retrospective descriptive study was performed to compare the results of open surgery and PCNL in the treatment of staghorn stones in 2013-2021. A total of 360 participants were studied among the population. Demographic data of patients including age, gender, and comorbidities were obtained. We assessed variables including type of stone, serum creatinine, degree of hydronephrosis, and urine culture before the operation. All participants in our study were informed of the two surgical alternatives.

RESULTS

The mean length of hospital stay in PCNL patients was 3.88 ± 1.76 and in open surgery patients was 5.858 ± 2.12 (P = 0.003). In 30 patients (13.9%) in the PCNL group and 27 patients (18.8%) in the open surgery group, bleeding necessitating blood transfusion was the only intraoperative complication. 309 patients (85%) had no residual stones at the time of discharge from the hospital, which was 81.9% (177 cases) in patients treated with PCNL and 91.6% (132 patients) in the open surgery group (P > 0.05).

CONCLUSION

Staghorn calculi can be managed effectively with open surgery or PCNL. Given the reduced postoperative complication rate and higher stone-free rate, we believe open surgery is better technique for complicated staghorn stones with a high burden.

One-stage efficacy of single tract minimally invasive ECIRS in the improved prone frog split-leg position for staghorn stones

OBJECTIVE

To explore the feasibility, safety, and effectiveness of single tract minimally invasive endoscopic combined intrarenal surgery (stmECIRS) in the improved prone frog split-leg position for staghorn stones.

METHOD

A total of 83 patients with staghorn stones were retrospectively reviewed between January 2018 and June 2021. According to surgical procedure and position, patients were divided into a group of single tract minimally invasive percutaneous nephroscopy (stmPNL) in the prone position and a group of stmECIRS in the improved prone frog split-leg position (turned to the prone position after preset the flexible ureteroscope sheath in lithotomy position, meanwhile, bend both hips and knees to be frog abduction). Demographic characteristics, laboratory tests, stone characters, surgical information, stone-free rate (SFR), and perioperative complications were observed and analyzed.

RESULTS

There were no significant differences in demographic characteristics, changes level of Scr and Hb, stone size, radiation density, length of hospital stay, and operation time between the two groups. One-stage SFR in the stmECIRS group was significantly higher than that in the stmPNL group (84.4% vs. 57.9%) (P = 0.007), only 2 patients required blood transfusion after surgery (P = 0.862), and other postoperative complications were not statistically significant (P = 0.345).

CONCLUSIONS

StmECIRS in improved prone frog split-leg position has a higher one-stage SFR than stmPNL for staghorn renal stones, and without complications increased, which is a safe, efficient and feasible treatment.

Efficacy and safety of 3D printing-assisted percutaneous nephrolithotomy in complex renal calculi

This study evaluated the efficacy and safety of 3D printing technology combined with percutaneous nephrolithotomy in the treatment of complex renal calculi. Ninety patients with complex renal calculi were randomly divided into a 3D printing group (45 patients) and a control group (45 patients). In the 3D printing group, a patient-specific 1:1 3D printing model was established based on the patient's thin-layer CT scanning data. A 3D printing model was used for preoperative communication between doctors and patients. Preoperative puncture training, channel design, residual stone prediction, and percutaneous nephrolithotomy were performed under the guidance of a 3D printing model and B-ultrasound. The control group was treated with the conventional B-ultrasound-guided puncture method. Results suggest that there was a statistically significant difference between the two groups (P < 0.05). The overall score of the doctor-patient communication objects in the 3D printing group was 19.32 ± 1.57 points, and in the control group, it was 14.51 ± 2.13 points. The operation time of the 3D printing group was 103.21 ± 13.49 min, and that of the control group was 126.12 ± 25.87 min. The calculi clearance rate of the 3D printing group was 96%, while that of the control group was 80%. The incidence of postoperative complications was 6.67% in the 3D printing group and 22.22% in the control group. Compared with traditional percutaneous nephrolithotomy, 3D printing technology combined with percutaneous nephrolithotomy can significantly enhance the effectiveness of doctor–patient communication, shorten operation time, reduce operation bleeding, improve the stone clearance rate, reduce the incidence of complications and shorten the length of hospital stay. The proposed method is thus a safe and effective method to treat complex renal calculi.

Combination laparoscopy and nephrolithotomy technique in the same session in patients with complete staghorn stones and poor performance status: case series in a single center with long-term follow-up

BACKGROUND

The management of complete staghorn stones remains a challenge for urologists, owing to the high stone burden, low stone free rate, and high rate of complications. Hence, we aimed to evaluate the outcomes of a technique involving combination laparoscopy and nephrolithotomy in the same session in patient with complete staghorn stones and poor performance status.

METHODS

We retrospectively evaluated seven patients with complete staghorn stones who underwent a combination of laparoscopy and nephrolithotomy in the same session in our center between December 2016 and October 2019. The surgical technique was as follows. Through a four-port transperitoneal laparoscopic approach, the kidney was mobilized after complete dissection of the renal pedicle. The renal pelvis was then incised with a cold scalpel. A nephroscope was inserted into the renal collecting system through both a laparoscopic port and the renal pelvis incision. This method enabled visualization of and access to almost all calyces for clearing the stones from the affected kidneys in a hand-assisted manner which a hand was inserted in the peritoneal cavity. The outcome data included the stone-free rate, short-term and long-term complication rates, and stone recurrence rate.

RESULTS

The stone free rate was 85.70% (6/7). No patients had sepsis or required blood transfusion perioperatively, and no major short-term complications occurred. After 24.00 (15.00, 48.00) months' follow-up, no patients had long-term complications, and only one patient had stone recurrence.

CONCLUSION

The technique of combining laparoscopy and nephrolithotomy in the same session was an effective and safe treatment for patients with complete staghorn stones and poor performance status. The method was scarcely affected by the stone burden and morphology, had a satisfactory stone free rate, and resulted in no major complications, particularly life-threatening sepsis. It might be an option for such patients.

Comparison of vacuum-assisted sheaths and normal sheaths in minimally invasive percutaneous nephrolithotomy: a systematic review and meta-analysis

BACKGROUND

A systematic review and meta-analysis was conducted to compare the safety and efficacy of vacuum-assisted sheaths and conventional sheaths in minimally invasive percutaneous nephrolithotomy (MPCNL) in the treatment of nephrolithiasis.

METHODS

PubMed, Web of Science, Embase, EBSCO, and Cochrane Library databases (updated March 2021) were used to search for studies assessing the effect of vacuum-assisted sheaths in patients who underwent MPCNL. The search strategy and study selection processes were implemented in accordance with the PRISMA statement.

RESULT

Three randomized controlled trials and two case-controlled trials that satisfied the inclusion criteria were enrolled in this meta-analysis. Overall, the stone-free rate (SFR) in patients who underwent vacuum-assisted sheaths was significantly higher than that in patients who underwent conventional sheaths (RR 1.23, 95% CI 1.04, 1.46, P = 0.02), with significant heterogeneity among the studies (I² = 72%, P = 0.03). In terms of the outcome of complications, vacuum-assisted sheath could bring a benefit to the postoperative infection rate (RR 0.48, 95% CI 0.33, 0.70, P < 0.00001) with insignificant heterogeneity among the studies (I² = 0%, P = 0.68). There was no significant difference in the blood transfusion rate (RR 0.35, 95% CI 0.07, 1.73, P = 0.17), with significant heterogeneity (I² = 66%, P = 0.35). Three studies contained operative time data, and the results indicated that the vacuum-assisted sheath led to a shorter operative time (MD = - 15.74; 95% CI - 1944, - 12.04, P < 0.00001) with insignificant heterogeneity (I² = 0%, P = 0.91).

CONCLUSION

The application of a vacuum-assisted sheath in MPCNL improves the safety and efficiency compared to the conventional sheath. A vacuum-assisted sheath significantly increases the SFR while reducing operative time and postoperative infection.

Single-use flexible ureteroscopes: update and perspective in developing countries. A narrative review

Flexible ureteroscopy is a well-established method for treatment of urinary stones but flexible ureteroscopes are expensive and fragile devices with a very limited lifetime. Since 2006 with the advent of digital flexible ureteroscopes a great evolution has occurred. The first single-use flexible ureteroscope was launched in 2011 and new models are coming to the market. The aim of this article is to review the characteristics of these devices, compare their results with the reusable devices and evaluate the cost-benefits of adopting single-use flexible ureteroscopes in developing countries.

Risk factors for urinary infection after retrograde upper urinary lithotripsy: Implication for nursing

There are needs to evaluate the risk factors for urinary infection after retrograde upper urinary lithotripsy, to provide insights into the management and nursing care of patients with retrograde upper urinary lithotripsy.Patients who received retrograde upper urinary lithotripsy with a Foley 20 urinary tube insertion from June 1, 2019 to December 31, 2020 in our hospital were selected. Patients were grouped urinary infection and no infection group according to the culture results of urine, and the clinical data of the 2 groups of patients were collected and compared. Single factor and logistic regression analysis were used to analyze the risk factors of urinary tract infection after retrograde upper urinary lithotripsy.Four hundred ten patients with retrograde upper urinary lithotripsy were included, of whom 62 patients had the urinary tract infection, the incidence of urinary tract infection was 15.12%. There were significant differences in the gender, age, diabetes, stone diameter, duration of urinary tube insertion and duration of surgery between infection and no-infection group (all P < .05). The Escherichia coli (62.90%) was the most commonly seen bacterial in patients with urinary tract infection. Female (odds ratio [OR]: 1.602, 95% confidence interval 95% [CI]: 1.132∼2.472), age >50 years (OR: 2.247, 95% CI: 1.346∼3.244), diabetes (OR: 2.228, 95% CI: 1.033∼3.451), stone diameter ≥2 cm (OR: 2.152, 95% CI: 1.395∼3.099), duration of urinary tube insertion ≥3 days (OR: 1.942, 95% CI:1.158∼2.632), duration of surgery ≥90 minutes (OR: 2.128, 95% CI: 1.104∼3.846) were the independent risk factors for the postoperative urinary tract infection in patients with retrograde upper urinary lithotripsy (all P < .05).The incidence of urinary tract infection in patients undergoing retrograde upper urinary lithotripsy was high, counteractive measures targeted on those risk factors are needed to prevent and reduce the postoperative urinary infection in clinical settings.

Effect of dietary treatment and fluid intake on the prevention of recurrent calcium stones and changes in urine composition: A meta-analysis and systematic review

To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) for investigating the effect of dietary treatment and fluid intake on the prevention of recurrent calcium stones and changes in urine composition. PubMed, Web of Science, Embase, EBSCO, and Cochrane Library databases (updated November 2020) were searched for studies with the following keywords: diet, fluid, recurrent, prevention, randomized controlled trials, and nephrolithiasis. The search strategy and study selection process was conducted by following the PRISMA statement. Six RCTs were identified for satisfying the inclusion criteria and enrolled in this meta-analysis. Our result showed that low protein with or without high fiber diet intervention does not decrease the recurrence of stone upon comparing with control groups (RR = 2.32, 95% CI = 0.42–12.85; P = 0.34) with significant heterogeneity among the studies (I² = 81%, P = 0.02). But normal-calcium, low protein, low-salt diet had recurrences did reduced the recurrence compared to normal-calcium diet. And the fluid intake has a positive effect on prevention of recurrent stone formation (RR = 0.39, 95% CI = 0.19–0.80; P = 0.01) with insignificant heterogeneity among the studies (I² = 9%, P = 0.30). The different components of urine at baseline were reported in four studies. Upon reviewing the low protein with or without high fiber dietary therapy groups, it was found that there were no obvious changes in the 24-hour urine sodium, calcium, citrate, urea, and sulfate. In conclusion, our study shows that the only low protein with or without fiber does not affect recurrence, but low Na, normal Ca diet has a marked effect on reducing recurrence of calcium stone. And fluid intake shows a significant reduction in the recurrence of calcium stone.

Comparison of safety and efficacy between single-tract and multiple-tract percutaneous nephrolithotomy treatment of complex renal calculi: a systematic review and meta-analysis

BACKGROUND

A systematic review and meta-analysis was conducted to explore the safety and efficacy of single-tract and multiple-tract percutaneous nephrolithotomy (PCNL) in complex renal calculi treatment.

METHODS

PubMed, Web of Science, Embase, EBSCO, and Cochrane library databases (updated November 2020) were searched for studies assessing the effect of different numbers of tracts on cases that underwent PCNL. The search strategy and study selection process were managed according to the PRISMA statement.

RESULTS

Five comparative studies were included in the meta-analysis. The multiple-tract PCNL group had a significantly increased total complications rate than the single-tract group (OR = 2.35, 95% CI = 1.71, 3.25; P < 0.00001) with insignificant heterogeneity (I2 = 0%, P = 0.52). Subgroup analysis showed there were different incidence of complications, mainly because the multiple-tract PCNL group was significantly associated with a higher rate of blood transfusion (OR = 2.99, 95% CI = 1.95, 4.57; P < 0.00001) with insignificant heterogeneity (I2 = 9%, P = 0.35). There were no differences in operation time (MD = 12.04, 95% CI = 6.36, 17.72; P < 0.0001) or hospitalization (MD = 0.54, 95% CI = 0.14, 0.95, p = 0.008). However, the singletract group had a higher stone-free rate (OR = 0.37, 95% CI = 0.19, 0.74; P = 0.005) with heterogeneity (I2 = 51%, P = 0.08), as stones in the single-tract group were smaller than those in the multiple-tract group.

CONCLUSIONS

The current research did not find that the multiple-tract group had a higher stone-free rate. Additionally, multiple-tract PCNL was associated with a higher incidence of blood transfusion and negative impact on renal function.

Residual Stone Fragments After Percutaneous Nephrolithotomy: Shockwave Lithotripsy vs Retrograde Intrarenal Surgery

Background: Despite technology incorporation to percutaneous nephrolithotomy (PCNL), residual stone fragments (RSFs) may still persist after PCNL and need to be addressed to avoid regrowth or ureteral obstruction. The objective of this study was to compare the outcomes of retrograde intrarenal surgery (RIRS) to extracorporeal shockwave lithotripsy (SWL) for treating patients with RSFs after a previous standard PCNL. Materials and Methods: Adult patients with RSF after a standard PCNL submitted to RIRS or SWL in our Institution from January 2017 to January 2020 were retrospectively studied. Stone-free rate (SFR) was evaluated on postoperative day (POD) 90 by noncontrast CT (NCCT) or ultrasound and kidney, ureter, and bladder radiograph (KUB) for each renal unit. Surgical complications based on Clavien-Dindo classification during the 90 days of follow-up were recorded. Sample size was calculated for a power of 80% and a significance level of 0.05, assuming SFR of 20% for SWL and 50% for RIRS. Results: Thirty-three patients treated by SWL were compared with 36 patients treated by RIRS. Hospitalization time was longer in the RIRS group (4.18 vs 12.33 hours, p = 0.001). SFR and success rate were lower in SWL than RIRS group (24.2% vs 58.3%, p = 0.007 and 30.3% vs 72.2%, p = 0.004, respectively), using POD 90 NCCT in 81.8% and ultrasound and KUB in 18.2% of the SWL group and using POD 90 NCCT in 100% of the RIRS group. Minor complications (Clavien-Dindo < III) occurred in 11 of 36 (30.6%) patients submitted to RIRS and in 2 of 33 (6.1%) patients submitted to SWL group (p = 0.025). Two patients (6.1%) of the SWL group had Clavien-Dindo IIIb complication owing to Steinstrasse and were submitted to ureteroscopy. Emergency room visits were similar between groups (6.1% vs 8.3%, p = 1.0). Conclusions: RIRS has better SFR, higher minor complications, and lower major complications than SWL for the treatment of RSFs after standard PCNL.

Percutaneous nephrolithotomy in patients with spinal cord injury: should all these patients be automatically assigned a Guy's stone score of 4?

PURPOSE

To assess the complication and stone-free rates of PCNL in patients with spinal cord injury (SCI) and to evaluate whether this population should be assigned a Guy's stone score (GSS) of 4.

METHODS

A case-control study was conducted, and electronic charts were reviewed to search for patients with SCI, bladder dysfunction, and kidney stones who had undergone PCNL. Control cases were randomly selected from among patients with complete staghorn calculus (GSS = 4).

RESULTS

One hundred and seventeen patients were included. Patients with SCI had a significant shorter operative time (119 vs. 141 min; p = 0.018). There were no significant differences between the groups in terms of the patients' position, number of renal tracts, bleeding or transfusion rate; however, there was a significantly higher complication rate (23.1% vs. 7.8%; p = 0.009) and a longer hospital stay (5.8 vs. 3.1 days; p = 0.002) among patients with SCI. With regards to the stone-free rate in patients with different grades of GSS patients with SCI who had a GSS of 1 had a stone-free rate of 85.7%, while those with a GSS of 2, 3, or 4 had 50%, 50%, and 31.5%, respectively (p = 0.024). Only patients with a GSS of 4 in the SCI group had outcomes that were similar to those of control patients (31.5% vs. 31.6%).

CONCLUSION

Patients with SCI should not be automatically assigned GSS 4. Stone-free rate is related to stone burden in these patients, although they do show a higher complication rate and a longer hospital stay than non-neurological patients.