Journal of Endourology

Cryoablation has emerged as an alternative to the more invasive partial nephrectomy for small renal masses. The approach can be carried out by two techniques, either laparoscopic cryoablation (LCA) or percutaneous cryoablation, (PCA) with CT guidance. We aimed to compare between the two procedures.

A systematic review and meta-analysis was conducted, including studies comparing the two techniques. Outcomes included incomplete ablation, late local recurrence, cancer-specific survival, procedure time, transfusion rates, hospital stay, and complications.

A total of 1475 patients were included, 788 patients in the laparoscopic group and 687 patients in the percutaneous group. There was statistical difference favoring the laparoscopic group with regard to having less incomplete ablation (p = 0.0008) and higher cancer-specific survival patients (p = 0.04). However, there was longer hospital stays in the LCA group (p < 0.00001) and was found to be more costly than the PCA group. There was significantly more Clavien-I complications in the PCA group (p = 0.001) and more Clavien-III complications in the LCA group (p = 0.001). Otherwise, there were no differences in any other outcome parameter.

LCA was found to have less incomplete tumor ablation rates and higher cancer-specific survival rates, however, higher hospitalization time, more major complications (Clavien III), and was costlier compared with PCA.

To compare the manufacturing and in vitro performance characteristics of two single-use flexible ureteroscopes with a permanent optical flexible ureteroscope.

Two single-use flexible ureteroscopes, LithoVue (Boston Scientific) and Pusen (1rs. generation; Zhuhai Pusen Medical Technology Company Limited, China), were tested and compared with a permanent Flex-X² ureteroscope (Karl Storz, Germany) in terms of technical characteristics, optics, deflection mechanism, and additional parameters which could potentially affect surgical technique.

Pusen was the lightest ureteroscope while the LithoVue had the longest working length. LithoVue had a higher resolution power than the other two ureteroscopes at all distances tested (p < 0.001). Pusen showed higher resolution than Flex-X² (p < 0.01). Field of view was wider for LithoVue (87°), followed by Flex-X² (85°) and Pusen (75°). Color representation was superior for Flex-X² than LithoVue and then Pusen. LithoVue outperformed Pusen and Flex-X² for all settings with instruments in terms of deflection loss (p < 0.01). Pusen had the highest irrigation flow (52 mL/min) with an empty working channel (p < 0.01). LithoVue and Pusen showed similar flow rates with a 200 μm (21 mL/min) and 365 μm laser fiber (7 mL/min) and 1.3F basket (18 mL/min), being superior to Flex-X² (p < 0.01). With the 1.9F basket, LithoVue had superior flow rate (7 mL/min) than Pusen (3.5 mL/min) and Flex-X² (4 mL/min; p = 0.01).

LithoVue outperformed the other ureteroscopes in terms of optical resolution, field of view, deflection capacity, and irrigation flow with larger instruments. Pusen is the lighter scope and showed better results in terms of irrigation when no instruments are in place. Flex-X² was superior in terms of color representation.

To evaluate the risk factors for postoperative fever and to identify the value of preoperative procalcitonin (PCT) in predicting postoperative fever after percutaneous nephrolithotomy (PNL).

Patients who underwent PNL between January 2014 and March 2017 were studied. In total, 363 medical records with complete data were determined to be eligible for analysis. Patients were classified into a control or febrile group according to the presence of a body temperature over 38°C. Demographic and perioperative data were compared between the groups. Variables found to be statistically significant were included in a binary logistic regression analysis.

Ninety-one (25.1%) patients experienced postoperative fever. Univariate analysis revealed a statistically significant difference between postoperative fever and factors, such as sex (p = 0.009), preoperative fever (p < 0.001), stone burden (p < 0.001), pyuria (p = 0.013), urine culture (p < 0.001), and serum levels of C-reactive protein (CRP) (p = 0.003), PCT (p < 0.001), and interleukin-6 (IL-6) (p = 0.003). Binary logistic regression analysis indicated the presence of preoperative fever (p = 0.037), stone burden >353 mm² (p = 0.002), PCT >0.05 ng/mL (p < 0.001), or positive urine culture (p = 0.004) as independent risk factors for postoperative fever following PNL.

We concluded that patients with preoperative fever, stone burden >353 mm², PCT >0.05 ng/mL, or positive urine culture were more likely to develop postoperative fever and that routinely detecting PCT levels before PNL would be helpful in predicting postoperative fever.

To evaluate the clinical efficacy, safety, and cost of retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) in the treatment for large renal stones in patients with a solitary kidney.

In this study, 117 patients with a solitary kidney who had undergone PCNL or RIRS for renal stones larger than 2 cm between January 2010 and December 2016 were retrospectively evaluated. The patients' demographic data, clinical characteristics, and perioperative outcomes were collected through a review of their medical records. Forty-three patients treated with PCNL were compared to 43 patients treated with RIRS by propensity score-matched analysis. The stone-free rate, retreatment rate, complication rate, and efficacy quotient (EQ) were assessed in both groups.

Initial stone-free rate of the PCNL group after a single procedure was significantly higher compared with the RIRS group (74.42% vs 34.88%, p < 0.001), whereas there was no significant difference in the final stone-free rate after repeated procedures (90.70% vs 88.37%, p = 0.713). PCNL had a significantly lower retreatment rate than RIRS (16.28% vs 63.79%, p < 0.001), and the PCNL group underwent fewer procedures than the RIRS group (p < 0.001). Thus, PCNL group had a higher EQ (78.00% vs 53.52%). Although cost per procedure of PCNL was significantly higher compared with RIRS (p < 0.001), the total costs were comparable. Complication rate of RIRS was lower compared with PCNL with no statistical significance (p = 0.193), and acute kidney injury rates were also comparable (PCNL vs RIRS: 13.95% vs 6.98%, p = 0.533).

With fewer repeated surgical procedures, higher EQ, and comparable total costs, PCNL is recommended as the first choice for the treatment of large renal calculi in patients with a solitary kidney. As for specific indications such as anticoagulant drugs, RIRS is a safer choice with fewer complications and acceptable final stone-free rate.

The incidence of spina bifida (SB) is ∼1:1000, and risk of stone disease is substantially raised in SB. This is the unique published study of the outcome of patients with SB undergoing percutaneous nephrolithotomy (PCNL) compared to a neurologically intact historically matched control group at the same institution.

A series of 96 PCNLs in 13 SB and 50 non-SB patients was analyzed. The following measurements were recorded: (1) Comorbidities; (2) Preoperative: (renal function, American Society of Anesthesiologists [ASA] score); (3) Intraoperative: (anesthesia time, number of tracks, stone-free rate); and (4) Postoperative: (sepsis, intensive therapy unit and total length of stay, transfusion rate, stone composition, rate of stone disease-related nephrectomy).

Retrograde access to the ureter was impossible in all cases of SB. The median ASA grade (OR 10.5, 95% confidence interval [CI] 2.6–42.7) and operative time (median difference 30 minutes, 95% CI 20–40) were both higher in the SB cohort. Surgeon's estimate of stone-free rate was significantly lower in the SB cohort (46% vs 82%). Intensive care requirement (0.29 days/PCNL vs 0.1 days/PCNL); total hospital stay (7 days vs 4 days); postoperative transfusion rate (11.8% vs 1.6%); and sepsis rate (38% vs 1.6%) were all significantly higher in the SB group. Repeat PCNL and nephrectomy for recurrent stone disease were both significantly increased in SB cohort compared to control group.

PCNL in patients with SB is associated with multiple parameters of poor outcome. Patients with SB should be counseled about increased peri-operative risk and likelihood of stone recurrence. In an era where hospitals are judged according to comparative outcomes, a case may be made for comparing PCNL in this cohort of patients separately because of the significantly increased peri- and postoperative morbidity.

There are no comparative assessments on the environmental impact of endourologic instruments. We evaluated and compared the environmental impact of single-use flexible ureteroscopes with reusable flexible ureteroscopes.

An analysis of the typical life cycle of the LithoVue™ (Boston Scientific) single-use digital flexible ureteroscope and Olympus Flexible Video Ureteroscope (URV-F) was performed. To measure the carbon footprint, data were obtained on manufacturing of single-use and reusable flexible ureteroscopes and from typical uses obtained with a reusable scope, including repairs, replacement instruments, and ultimate disposal of both ureteroscopes. The solid waste generated (kg) and energy consumed (kWh) during each case were quantified and converted into their equivalent mass of carbon dioxide (kg of CO₂) released.

Flexible ureteroscopic raw materials composed of plastic (90%), steel (4%), electronics (4%), and rubber (2%). The manufacturing cost of a flexible ureteroscope was 11.49 kg of CO₂ per 1 kg of ureteroscope. The weight of the single-use LithoVue and URV-F flexible ureteroscope was 0.3 and 1 kg, respectively. The total carbon footprint of the lifecycle assessment of the LithoVue was 4.43 kg of CO₂ per endourologic case. The total carbon footprint of the lifecycle of the reusable ureteroscope was 4.47 kg of CO₂ per case.

The environmental impacts of the reusable flexible ureteroscope and the single-use flexible ureteroscope are comparable. Urologists should be aware that the typical life cycle of urologic instruments is a concerning source of environmental emissions.

To describe the technique of laparoscopic in situ dismembered pyeloplasty as a modified technique during which the alignment of ureter and renal pelvis remains intact during ureteropelvic junction (UPJ) anastomosis. We also assessed intraoperative and postoperative outcomes of this modification in comparison to standard laparoscopic dismembered pyeloplasty.

Patients with significant primary UPJ obstruction without any history of abdominal surgery, high ureter insertion, or renal anomalies were considered. The patients were consecutively enrolled one after another into one of two study groups: classic laparoscopic dismembered pyeloplasty (Group I) or laparoscopic in situ dismembered pyeloplasty (Group II), however, those with aberrant vessels crossing the UPJ were allocated specifically to Group I because UPJ anastomosis should be done anterior to the aberrant vessels. Demographic data, intraoperative timings, and postoperative and follow-up outcomes were compared in the two groups.

Patients in Group I (n = 23) and Group II (n = 14) had similar demographic characteristics. Mean operative time was significantly longer in Group I (103.8 ± 19.95 minutes vs 89.5 ± 18.90 minutes, p = 0.038). Total duration of UPJ repair and anastomosis was also significantly longer in Group I (92.7 ± 15.82 minutes vs 78.4 ± 14.76 minutes, p = 0.021). The method of pyeloplasty significantly affected the time required to prepare ureter and renal pelvis (p = 0.017) and the duration of UPJ anastomosis (p = 0.014). Both were shorter in Group II. Mean follow-up period was 14.4 ± 7.42 months in Group I and 14.05 ± 7.93 months in Group II (p = 0.88). Success rate was 95.6% in Group I and 100% in Group II (p = 0.42).

Laparoscopic in situ pyeloplasty is a safe and effective approach that can help simplify laparoscopic pyeloplasty, especially at teaching centers where surgeons with variable levels of experience perform laparoscopic procedures.

This prospective study aimed to evaluate the effect of ramping and pause protocols on renal fibrosis, blood pressure control, and renal function in patients receiving extracorporeal shockwave lithotripsy (SWL).

This study prospectively recruited 320 patients with solitary radiopaque renal stones <15 mm in size. Patients were randomized to receive one of four shockwave protocols: (1) standard protocol (no ramping or pause); (2) ramping protocol alone; (3) ramping and pause protocols; or (4) pause protocol alone. Spot urine samples were collected before and for 2 years after treatment to monitor the levels of the renal fibrosis marker procollagen III aminoterminal propeptide (PIIINP) by blinded research staffs. Blood pressure and serum creatinine levels were also monitored during follow-up.

The four groups had comparable baseline data and treatment parameters. Significant increases (p < 0.05) in the urinary PIIINP levels from 6 weeks until 18 months after SWL were observed among all patients and in individual groups. PIIINP levels peaked at 1 year after SWL and gradually decreased to the baseline at 2 years. At the 2-year follow-up point, the overall serum creatinine levels remained significantly elevated (76.21–80.01 μmol/L, p < 0.001). Twenty (9.95%) patients developed new-onset hypertension and another 43 (36.4%) experienced worsening blood pressure control. However, no differences were observed among the four treatment groups.

SWL led to significant increases in renal fibrosis marker levels for up to 18 months after treatment. However, no differences in changes in renal fibrosis marker and serum creatinine levels and worsening of blood pressure control were observed with respect to the use of either ramping or pause treatment protocols.

The holmium YAG (Ho:YAG) laser penetration depth (PD) of 0.4 mm has been widely described. Nonetheless, in physics, this concept refers to the tissue thickness at which 90% of the energy has been absorbed and not to the incision depth (ID) that the laser can achieve in tissue. The aim of this study is to evaluate the ablation efficiency of Ho:YAG laser on soft tissue.

With an automated robotic arm, systematic fissures were performed on flat veal kidney specimens. Broad setting spectrums from 2.5 to 80 W, short and long pulse, were tested with 272 and 365 μm laser fibers. Experiments were repeated three times. Two pathologists in a blinded manner measured the width, depth, and coagulation area with electronic microscopy.

The overall mean ID was 2 mm (0.25–4.39) and the mean width was 1 mm (0.3–3.1). The mean coagulation thickness was 0.48 mm (0.25–1.73). The higher the frequency and energy, the deeper and wider was the incision p < 0.001. No differences were observed regarding the fiber diameter. The pulse length did not affect the ID, although the mean width was greater with short pulse p = 0.04. The outer mean coagulation was increased by increasing energy but not by increasing frequency p > 0.119.

The overall mean ID was significantly higher than the theoretical 0.4 mm PD described for Ho:YAG laser. The energy, frequency, and pulse length had individual effects regarding ID, incision width, and coagulation. The ID should be specified in accordance with the laser's power output and should not be confused with the physics of PD concept.

Intrarenal inflammation has been implicated in the pathogenesis of nephrolithiasis, with prior work showing increased urine levels of IL-6, IL-8, and CCL-2 in stone patients. However, no studies have assessed for inflammation in the renal papillae. We sought to characterize novel papillary tip and urinary biomarkers in stone patients.

Ninety-two patients with nephrolithiasis undergoing percutaneous nephrolithotomy were enrolled. Papillary tip biopsies, kidney urine, and bladder urine were collected, as well as voided urine from eight healthy volunteers. Quantitative polymerase chain reaction was performed to measure inflammatory gene expression.

Initial 84-gene polymerase chain reaction array revealed significant elevation of several cytokines in stone patients vs controls (fold change 2.3–694). Twenty-four genes were selected for final analysis. In 41 pairs of urine samples, levels of CCL5, CD40, FasL, RIPK2, SELE, TLR3, and IL-15 were significantly elevated in kidney vs bladder urine (p0.0001–0.04). In 23 triplets of samples, expression of these cytokines plus CCL2, CCL7, CCR2, CSF1, CXCL9, and CXCL10, was significantly greater in papillary tips vs urine samples (p0.001–0.05). Cytokine elevation was independent of maximum postoperative heart rate, respiratory rate, temperature, leukocyte count, urinary tract infection in the past year, presence or absence of antibiotics at the time of surgery, and stone composition (all p > 0.05).

Expression of CCL-2, CCL-5, CCL-7, CCR-2, CD40, CSF1, CXCL-9, CXCL-10, Fas-L, RIPK2, SELE, and TLR-3 is markedly elevated in the papillary tips, kidney urine, and bladder urine of nephrolithiasis patients. Cytokine elevation was independent of signs of systemic inflammation. These findings further support the role of inflammation in nephrolithiasis and imply that the inflammatory process likely begins at the renal papillae. These may represent novel biomarkers of stone disease, which may be useful in basic nephrolithiasis research, disease diagnosis, and prognosis.

Arterioureteral fistula (AUF) is a rare but potentially life-threatening disease that primarily arises as a long-term complication in oncological patients who have permanent ureteral stenting. The incidence is rising. The objective of this study was to outline the risk factors for management and outcome of AUF in a large individual case series.

Twenty-six AUF cases in 24 patients from six German tertiary referral centers occurring between 2008 and 2016 were identified retrospectively and entered into a dedicated database by using patient notes and out-patient visits.

Of 24 patients, 23 had a history of abdominopelvic surgery for oncological disease, 21/24 had undergone radiotherapy, and 23/24 had long-term ureteral stenting. All cases presented with visible hematuria, 11/26 at the time of a stent exchange. Blood transfusions were required in 92.3%, and intravenous inotropes were needed in 46.2%. Of 26 patients, 11 had flank pain. CT angiogram was positive in 35.7%. Angiography and endovascular fistula repair was performed in 88.5%, and the rest received open surgical repair. Mortality was 7.7%. Endovascular treatment was technically successful in 91.3%, and open surgery was successful in 3/4 cases. Recurrent AUF developed in 3/24 patients. Stent-related complications occurred in 15%. Vascular complications were common. Long-term survival was limited due to progression of the underlying malignant disease.

AUF results in major hemorrhage and warrants time-efficient diagnosis and treatment. Awareness is key. When AUF is considered, interventional angiography should promptly be performed. Fistula detection can be improved by guidewire manipulation. Pre-interventional CT angiogram may be omitted due to low sensitivity. Endovascular repair with stenting and/or coiling is effective and safe.

To measure needle tip deflection during transrectal ultrasound (TRUS) prostate biopsy and evaluate predictors for needle tip deflection.

Analysis of 568 prostate biopsies obtained from 51 consecutive patients who underwent a standard 12-core TRUS guided prostate biopsy. TRUS guided prostate biopsies were performed using BK flex500, with a side-fire biplane probe. Each biopsy core image was captured and clinical data were recorded prospectively. The angle between the expected trajectory of the needle and actual needle course was measured using the longitudinal view of the captured image. The distance between expected and actual needle tip was calculated. We measured median and interquartile needle tip deflection rate stratified by side and location (apex, midgland, base). Univariable and multivariable linear regressions analysis were performed.

The overall median needle tip deflection was 1.77 mm (IQR 1.35–2.47). Location did not significantly alter needle deflection measurements. On multivariable linear regression analysis, higher prostate volume (B = 0.007 95%, CI 0.004, 0.011; p < 0.001) and the right sided biopsy (B = 0.191 95%, CI 0.047, 0.336; p = 0.010) emerged as predictors of higher needle tip deflection.

To the best of our knowledge this is the first study to measure needle tip deflection during TRUS guided prostate biopsies. We demonstrated that larger prostate size and biopsy side may affect the accuracy of biopsies. These results may have clinical implication to those performing targeted biopsies.

To evaluate the efficacy and safety of ureteroscopic thulium laser (TL) treatment of upper urinary tract carcinoma (UTUC).

Forty-two consecutive patients underwent conservative TL treatment for UTUC at two referral institutions. All patients underwent preliminary biopsy and then laser vaporization. A 272 μm and 365 μm laser fibers were used with a flexible and semirigid scope, respectively. Ablation was carried out with a 10 to 20 W power.

Mean age at surgery was 68 years (SD 10.7). Mean tumor size was 14.3 mm (range 2–30 mm). Preliminary biopsy revealed the presence of low-grade disease in 29 (69.1%) patients, high-grade disease in 4 (9.5%) and 1 carcinoma in situ 1 (2.4%), whereas it was not conclusive in 8 (19%) cases. Final stage was pTa and pTis in 41 (97.6%) and 1 (2.4%) patients, respectively. Thirty eight percent (16) experienced Clavien–Dindo grade I complication, 47.6% (20) grade II, and 2.4% (1) grade III. Five (12%) patients underwent a second-look procedure due to residual disease. Eight (19%) patients experienced clinical recurrence. The median estimated recurrence-free survival was 44 months (SE 3.68). Four patients (9.5%) underwent a nephroureterectomy. Final pathological stage was pTis, pT3 high grade, pTa low grade, and pT0. Median follow-up was 26.3 months (range 2–54 months), and no progression or upstaging of disease occurred.

TL management of UTUC is a safe and efficacious conservative treatment. Our experience shows optimal vaporization and hemostatic control in the absence of major complications.