Ureteral stricture rate after endoscopic treatments for urolithiasis and related risk factors: systematic review and meta-analysis

PURPOSE

We aimed to accurately determine ureteral stricture (US) rates following urolithiasis treatments and their related risk factors.

METHODS

We conducted a systematic review and meta-analysis following the PRISMA guidelines using databases from inception to November 2023. Studies were deemed eligible for analysis if they included ≥ 18 years old patients with urinary lithiasis (Patients) who were subjected to endoscopic treatment (Intervention) with ureteroscopy (URS), percutaneous nephrolithotomy (PCNL), or shock wave lithotripsy (SWL) (Comparator) to assess the incidence of US (Outcome) in prospective and retrospective studies (Study design).

RESULTS

A total of 43 studies were included. The pooled US rate was 1.3% post-SWL and 2.1% post-PCNL. The pooled rate of US post-URS was 1.9% but raised to 2.7% considering the last five years' studies and 4.9% if the stone was impacted. Moreover, the pooled US rate differed if follow-ups were under or over six months. Patients with proximal ureteral stone, preoperative hydronephrosis, intraoperative ureteral perforation, and impacted stones showed higher US risk post-endoscopic intervention with odds ratio of 1.6 (P = 0.05), 2.6 (P = 0.009), 7.1 (P < 0.001), and 7.47 (P = 0.003), respectively.

CONCLUSIONS

The overall US rate ranges from 0.3 to 4.9%, with an increasing trend in the last few years. It is influenced by type of treatment, stone location and impaction, preoperative hydronephrosis and intraoperative perforation. Future standardized reporting and prospective and more extended follow-up studies might contribute to a better understanding of US risks related to calculi treatment.

Entering into 2.0 cystinuric management with a medical digital tool to monitor urine pH: a prospective, randomized study

BACKGROUND AND OBJECTIVES

Individuals with cystinuria can experiment recurrent lithiasis events due to the relative insolubility of cystine at physiological urine pH, resulting in renal function decline. The Lit-Control® pH Meter is a medical device that accurately allows urine pH self-monitoring. The main objective of this study was to compare the usability of the Lit-Control® pH Meter with the reactive strips for self-monitoring of urinary pH at home by patients with cystinuria, and their overall satisfaction with each tool.

PATIENTS AND METHODS

We included 28 patients (9 females and 19 males, age 19-76 years), who were randomly assigned to monitor their urine pH with reactive strips (n = 17) or the Lit-Control® pH-meter (n = 11).

RESULTS

After six months of use, the satisfaction with the two methods was similarly high, but the patients rated (0-10 scale) the pH meter better in terms of ease of learning (mean ± SD, 8.11 ± 0.60 vs. 7.06 ± 1.18; P = 0.038), ease to prepare (8.22 ± 0.67 vs. 7.25 ± 1.18; P = 0.034), and ease of use (8.22 ± 0.67 vs. 7.25 ± 1.39; P = 0.062). Overall, patients did not reach the alkalinization goals (pH between 7.0 and 8.0).

CONCLUSIONS

The Lit-Control® pH Meter demonstrated to be an easy-to-use device that can facilitate urinary pH control by cystinuric patients. A prospective study is warranted to assess the correlation between urine pH monitoring, a treat to target approach, and the recurrence of cystine stones.

Does gender influence retrograde intrarenal surgery (RIRS) outcomes? Data from the Flexible Ureteroscopy Outcomes Registry (FLEXOR)

INTRODUCTION AND OBJECTIVES

As well established flexible ureteroscopy (RIRS). There is still no evidence if gender can have any influence on the outcomes and complication when performing. This study aims to evaluate the role that gender has in performing flexible ureteroscopy from a large series of patients.

METHODS

This study retrospectively analyzed patients who underwent RIRS for renal stones from January 2018 to August 2021 within the multicentric FLEXOR registry. Demographics, stone characteristics, perioperative findings, results and complications were analyzed and compared between gender groups.

RESULTS

A total of 6669 patients were included, 66.1% were male and 33.9% were female. Stone characteristics was comparable between groups. Female patients had significant higher fever and positive urine culture rates (12% vs. 8% and 37% vs. 34%). Also, females had a slight longer hospital stay (3.8 vs. 3.5 days; P < 0.001) and more residual fragments after the procedure (23.03% vs. 20.97 (P = 0.032). Overall complications were slightly significantly higher in women (15.74% vs. 14% (P = 0.042)) mainly at the expense of fever rates (6.9% vs. 5.7%) whereas the risk of sepsis was similar in both groups. A multivariate analysis showed that larger stone size, multiple and lower pole stones seem to have a negative impact in the incidence of residual stones and complications.

CONCLUSION

Our real life global study reflects that female gender may have a correlation with a slightly increased residual fragment rate and overall low grade complications. However, women can safely be treated with RIRS with no increased the rate of sepsis with appropriate care.

Assessment of intrarenal temperature dynamics when using holmium and thulium: YAG lasers in an ex vivo porcine kidney model

AIM

To measure the temperature dynamics at the renal surface and within the urinary tract when using Ho:YAG and Tm:YAG lasers for tissue ablation.

MATERIALS AND METHODS

Porcine kidneys were used. Both types of lasers with different configurations and fiber sizes were used through a flexible ureteroscope. The temperature at the renal surface was recorded using a thermal camera while the intrarenal temperature was measured using two thermal probes, the first one at the ureteropelvic junction and the second one at the calyx used for lasering. Temperature was determined at 0.5-1-3-5 and 10 min.

RESULTS

Recordings at the ureteropelvic junction and calyx revealed significant increases when using Tm:YAG with the 273 μm (10 W to 50 W) (p ≤ 0.02) and 550 μm (10 W) fiber (p = 0.04). With Ho:YAG there was a significant increase when using 273 μm (at 10 W and 20 W) (p ≤ 0.03) and 365 μm (10 W) fibers (p = 0.04). Regarding fiber size there was a significant difference when using Tm:YAG (at 20 W and 40 W) (p < 0.05). The thermal camera recorded a mean increase of 8 °C in the UPJ while the remaining areas of the kidney did not undergo significant changes.

CONCLUSIONS

Temperature changes were greater when using the Ho:YAG laser with respect to Tm:YAG at similar power settings for tissue ablation. The greatest temperature increase was recorded at the UPJ from where the heat dissipated throughout the kidney.

Totally fluoroless retrograde intrarenal surgery technique in prestented patients: tips and tricks

Treatment of urolithiasis has evolved greatly as retrograde intrarenal surgery (RIRS) has gained popularity nowadays being a gold standard therapy for renal stones up to 2 cm. Endourological procedures are traditionally fluoroscopic guided; thus, an increasing concern is the harm of radiation exposure, especially in the pediatric population. Therefore, performing fluoroless RIRS should be a feasible option for pediatric urologists. Herein, we describe the technique of totally fluoroless RIRS in presented patients and the tips to avoid radiation use at most.

Can endoscopic balloon dilation for primary obstructive megaureter be effective in a long-term follow-up?

BACKGROUND

Ureteral tapering and reimplantation is an established treatment for persistent or progressive primary obstructive megaureter (POM) but may result in complications and morbidity. Use of a less invasive technique involving endoscopic balloon dilation appears very interesting.

OBJECTIVE

The objective of this report is to determine if endoscopic balloon dilation for POM is effective in the long term as well as to assess complications of the procedure.

MATERIAL AND METHODS

A retrospective review was done on 19 patients and 20 ureters treated with the endoscopic balloon dilation by POM from June 2000 to February 2010. Surgery was performed solely in those cases in which there was persistence of obstruction in the renogram along with one or all of the following conditions: impairment of the differential renal function <40%, worsening of the renal pelvic dilation, febrile UTI in spite of antibiotic prophylaxis or renal calculi. The patients comprised 16 boys and 3 girls with a mean age at surgery of 17 months (range 1-44 months). Ten cases were left sided, eight right sided, and one bilateral. Under endoscopic and fluoroscopic guidance, a 3-5 Fr dilating balloon was inflated to 12-14 atm, or until disappearance of the stenotic obstructive area. A double J stent was positioned and withdrawn 2 months later. Follow-up recorded the presence of symptoms, number of reintervention procedures registered, and included renal ultrasound and MAG-3 renogram.

RESULTS

There were no perioperative complications. Eighteen ureters showed a non-obstructive pattern on MAG-3 renogram after the first endoscopic dilation, representing a 90% success rate. One case required a second dilation, which proved successful and two cases of recurrent lithiasis required ureterotomy without instances of obstruction. 2 patients had a febrile UTI and a vesicoureteral reflux was diagnosed in one. Renal function was preserved in 95% of patients. The mean follow-up was 6.9 years (range 3.9-13.3 years). One patient was lost after the procedure.

DISCUSSION

In an era of minimally invasive techniques, the search for less invasive procedures for treatment of POM has resulted in a variety of surgical options. Angulo et al., in 1998 and our group described the first POM treatment with endoscopic balloon dilation, which is believed to be a definitive, less invasive, and safe treatment. Furthermore, should an endoscopic approach fail, reimplant surgery can be performed. Few publications have reported short series with good results in the short and medium term. Torino et al. presented five cases in children aged less than 1 year, none of these showed evidence of obstruction. García-Aparicio et al. presented a series of 13 patients treated with a success rate of 84.6%. Christman et al. added laser incision in cases of narrowed ureteral segment 2-3 cm long and used double stenting. Good outcomes were presented in 71%. Romero et al. reported improvement of drainage within the first 18 months after treatment in 69% of patients. The potential de novo onset of vesicoureteral reflux may be the source of some controversy. We consider that dilation does not significantly alter the antireflux mechanism. In VCUG is not systematically performed because it is an invasive test. This restricts the conclusions that can be drawn from our findings. Nevertheless, some groups continue to systematically perform VCUG.

CONCLUSIONS

Endoscopic balloon dilation for POM is a safe, feasible, and less invasive procedure that shows good outcomes on long-term follow-up. However, multicenter studies and prospective trials should be encouraged to provide more definitive evidence on its benefits.

Extraction of a bladder stone in a child as described by the renaissance physician Cristóbal Méndez

INTRODUCTION

in his Libro del exercicio y de sus provechos (Book of exercise and profits), the Spanish Renaissance physician Christopher Mendez (1500-1553) describes extracting a bulk stone from the bladder of a child younger than 5 years in the land of colonial Mexico. This is the first description of a surgical procedure in America.

MATERIAL AND METHODS

Biographical data were collected on Christopher Mendez. The electronic facsimile of the Book of exercise and profits was read. The historical aspects of perineal lithotomy and etiology of bladder stones were analyzed.

RESULTS

In chapter seven of the third treatise (page 120), Mendez speaks about the removal of a bladder stone in a boy named «Villaseñor». It uses the word «open» to describe the procedure, corresponding to a lithotomy more than a necropsy. It attributes the etiology of excess movements after ingestion and suggests a possible hereditary etiology.

DISCUSSION

Perineal lithotomy was a common practice in ancient times for children due to the high incidence of bladder stones. The technique was very invasive and was improved over the centuries.

CONCLUSIONS

The surgery described by Mendez for the child called Villaseñor most likely corresponds to a perineal lithotomy. A congenital cause could play a role in its etiology.

[A new approach to urinary stone analysis according to the combination of the components: experience with 7949 cases]

OBJECTIVE

To evaluate a new approach to urinary stone analysis according to the combination of the components.

MATERIALS AND METHODS

A total of 7949 stones were analysed and their main components and combinations of components were classified according to gender and age. Statistical analysis was performed using the chi-square test.

RESULTS

Calcium oxalate monohydrate (COM) was the most frequent component in both males (39%) and females (37.4%), followed by calcium oxalate dihydrate (COD) (28%) and uric acid (URI) (14.6%) in males and by phosphate (PHO) (22.2%) and COD (19.6%) in females (p=0.0001). In young people, COD and PHO were the most frequent components in males and females respectively (p=0.0001). In older patients, COM and URI (in that order) were the most frequent components in both genders (p=0.0001). COM is oxalate dependent and is related to diets with a high oxalate content and low water intake. The progressive increase in URI with age is related mainly to overweight and metabolic syndrome. Regarding the combinations of components, the most frequent were COM (26.3%), COD+Apatite (APA) (15.5%), URI (10%) and COM+COD (7.5%) (p=0.0001).

CONCLUSIONS

This study reports not only the composition of stones but also the main combinations of components according to age and gender. The results prove that stone composition is related to the changes in dietary habits and life-style that occur over a lifetime, and the morphological structure of stones is indicative of the aetiopathogenic mechanisms.

Novel (60%) and recurrent (40%) androgen receptor gene mutations in a series of 59 patients with a 46,XY disorder of sex development

BACKGROUND

Androgen receptor (AR) gene mutations are the most frequent cause of 46,XY disorders of sex development (DSD) and are associated with a variety of phenotypes, ranging from phenotypic women [complete androgen insensitivity syndrome (CAIS)] to milder degrees of undervirilization (partial form or PAIS) or men with only infertility (mild form or MAIS).

OBJECTIVE

The aim of the study was to characterize the contribution of the AR gene to the molecular cause of 46,XY DSD in a series of Spanish patients.

SETTING

We studied a series of 133 index patients with 46,XY DSD in whom gonads were differentiated as testes, with phenotypes including varying degrees of undervirilization, and in whom the AR gene was the first candidate for a molecular analysis.

METHODS

The AR gene was sequenced (exons 1 to 8 with intronic flanking regions) in all patients and in family members of 61% of AR-mutated gene patients.

RESULTS

AR gene mutations were found in 59 individuals (44.4% of index patients), of whom 46 (78%) were CAIS and 13 (22%) PAIS. Fifty-seven different mutations were found: 21.0% located in exon 1, 15.8% in exons 2 and 3, 57.9% in exons 4-8, and 5.3% intronic. Twenty-three mutations (40.4%) had been previously described and 34 (59.6%) were novel.

CONCLUSIONS

AR gene mutation is the most frequent cause of 46,XY DSD, with a clearly higher frequency in the complete phenotype. Mutations spread along the whole coding sequence, including exon 1. This series shows that 60% of mutations detected during the period 2002-2009 were novel.

Hematoma espontáneo paracavernoso

We report a case of spontaneous, perineal haematoma depending on corpora cavernosa but without injury of them. No erectile dysfunction was associated. Not traumatic injury was known. Etiopathology, diagnosis and treatment are analyses.

Clamping of the Renal Artery in Laparoscopic Partial Nephrectomy: An Old Device for a New Technique

OBJECTIVE

We describe our experience with the transient clamping of the renal artery during laparoscopic partial nephrectomy for renal cancer with a double loop clamping device, inspired by the Rumel tourniquet. The silastic rubber loop is positioned around the renal artery and clinched, thus achieving arterial occlusion.

METHODS

From November 2002 until July 2004, fourteen consecutive patients (mean age of 58 +/- 11.6 years) underwent laparoscopic transperitoneal partial nephrectomy using the silastic rubber clamping device, eight of them on the right side and six on the left side. Hemorrhage of the renal defect was controlled with bipolar electrocoagulation, argon beam coagulation, laparoscopic sutures, surgical and fibrin glue.

RESULTS

: The mean surgical time was 198.92 +/- 39.95 min for a mean tumour size of 2.9 +/- 2.32 cm and a mean blood loss of 104.57 +/- 77.69 ml. The clamping device was easily and successfully positioned around the renal artery in 2.05 +/- 0.45 min and the mean warm ischemic time was 25.21 +/- 6.07 min.

CONCLUSIONS

The clamping device procures successful atraumatic occlusion of the renal artery during laparoscopic partial nephrectomy without the need for an additional port. As such, it could be considered as an alternative for the laparoscopic bulldog and Satinsky clamp.