The 90% minimum effective volume and concentration of ropivacaine for ultrasound-guided median nerve block in children aged 1–3 years: A biased-coin design up-and-down sequential allocation trial

BackgroundMedian nerve block can provide excellent analgesia during open surgery for trigger thumb in children. However, no data on the 90% minimum effective volume (MEV₉₀) and concentration (MEC₉₀) of ropivacaine for ultrasound-guided median nerve block in pediatric patients have been reported.DesignA prospective two-phase study with an up-and-down sequential allocation trial using a biased coin design.PatientsChildren aged 1–3 years are experiencing open surgery for trigger thumb.InterventionThis study has 2 parts, one for MEV₉₀ and subsequently studied MEC₉₀ from the former part of the study. The MEV₉₀ and MEC₉₀ of ropivacaine for each subsequent patient were determined by the response of the previous patient, with the biased coin design up-and-down sequential allocation trial. The interval of -volume or concentration was -0.1 ml or 0.01%, respectively.MeasurementsThe MEV₉₀ and MEC₉₀ of ropivacaine for ultrasound-guided median nerve block in pediatric patients, were then used to estimate the 99% minimum effective volume (MEV₉₉) and concentration (MEC₉₉). The patient's general condition, postoperative pain, and adverse events.Main resultsA total of one hundred and eighteen children were enrolled for the study, and 56 and 62 patients were enrolled for the MEV₉₀ and MEC₉₀ studies, respectively. The MEV₉₀ of 0.2% ropivacaine was 1.44 ml (95% CI 1.043 ml, 1.466 ml), and the MEC₉₀ of 1.5 ml ropivacaine was 0.195% (95% CI 0.159%, 0.197%). There were no adverse events that occurred.ConclusionFor ultrasound-guided median nerve block in children aged 1–3 years old with trigger finger undergoing open surgery, the MEV₉₀ of 0.2% ropivacaine is 1.44 ml (95% CI 1.043 ml, 1.466 ml), and the MEC₉₀ of 1.5 ml of ropivacaine is 0.195% (95% CI 0.159%, 0.197%).     

The Perceived Stress Scale for Kids (PeSSKi): Initial development of a brief measure for children aged 7–11 years

Perceived stress, a known risk factor for poor health, has been extensively assessed in adult populations. Yet an equivalent assessment tool for measurement of global perceived stress in children is lacking. This study aimed to develop and provide initial validation of a scale to measure perceived stress in children aged 7–11 years. Using a two-phase design, we conducted semi-structured interviews with thirteen child-parent dyads for development of items. In a sample of 123 children (age range 7–11 years, Mage = 9 years 7 months, 54.5% male) we administered the resulting Perceived Stress Scale for Kids (PeSSKi). Exploratory factor analysis of the 10-item PeSSKi yielded support for both a one-factor and a two-factor solution (negative, positive item wording). The PeSSKi was associated positively with the Penn-State Worry Questionnaire for Children (r = 0.748, p < 0.001) and negatively with the Students' Life Satisfaction Scale (r = 0.381, p < 0.001) indicating strong convergent/divergent validity respectively. Girls showed higher scores on the PeSSKi than boys with no effects observed by age. Initial psychometrics suggest the PeSSKi provides a robust scale for assessment of perceived stress in children. Further validation is needed across different child populations, over time and with physical measures of stress and health outcomes.     

Long bone robustness during growth: A cross-sectional pQCT examination of children and young adults aged 5–29 years

Skeletal robustness (cross-section size relative to length) is associated with stress fractures in adults, and appears to explain the high incidence of distal radius fractures in adolescents. However, little is known about the ontogeny of long bone robustness during the first three decades of life. Therefore, we explored the ontogeny of tibial, fibular, ulnar and radial robustness in a cross-sectional sample of 5 to 29 year-old volunteers of both sexes. Peripheral quantitative computed tomography (pQCT) was used to evaluate cross-sections of the leg (4%, 14%, 38% and 66%), and forearm (4%, and 66%) in N = 432 individuals. Robustness was evaluated as the total bone area divided by bone length. Differences between age-groups, sexes, and age-group × sex interactions were evaluated with ANOVA with Tukey's post hocs where appropriate. Most bone sites exhibited more robust bones in men than women (P < 0.001 to 0.02), and in older age-groups than younger (P < 0.001). Sex × age-group interaction was observed at the 66% and 38% tibia sites with robustness increasing more with age in men than in women (P = 0.006 to 0.042). Post-hoc analyses indicated no sex differences prior to 13 years-of-age, and notable exceptions to increasing robustness with age at the 4% radial and 66% tibial sites, which exhibited reduced robustness in age groups close to peak height velocity. In conclusion, the present results suggest that very little sexual dimorphism in long bone robustness exists prior to puberty, and that divergence occurs primarily after cessation of longitudinal growth. A period of relative diaphyseal slenderness was identified at age-groups coinciding with the adolescent growth spurt, which may be related to the relatively high incidence of frank and stress fracture in adolescents.     

Clinical features and surgical outcomes of cervical spondylotic myelopathy in patients aged 80?years or older: a multi-center retrospective study

With the aging of the population in developed countries, spine surgeons have recently been more likely to encounter elderly patients in need of treatment. This study investigated whether decompression surgery for cervical spondylotic myelopathy (CSM) in elderly patients aged 80 years or older would likely be a reasonable treatment. We retrospectively reviewed 605 consecutive patients with cervical myelopathy who underwent decompression surgery between 2004 and 2008. Patients with other conditions that could affect functional status or compression factors other than spondylosis were excluded from this study. Of the remaining 189 patients, 161 with CSM whose condition could be evaluated 6 months after surgery were analyzed. The patients were divided into two age groups: 80 years or older (Group A, 37 patients) and younger than 80 years of age (Group B, 124 patients). We evaluated the differences in symptom duration, clinical data, involved levels, surgical outcome, comorbidities, and postoperative complications between the two groups. The symptom duration was significantly shorter in Group A. The average JOA scores preoperatively and 6 months postoperatively were significantly lower in Group A; however, there was no significant difference in the recovery ratio. There were no significant differences in the percentages of patients with comorbidities or those with postoperative complications. Elderly patients aged 80 years or older regained approximately 40% of their function postoperatively, and the incidence of postoperative complication was similar to that in younger patients. Since this age group shows a rapid deterioration after onset, prompt decompression surgery is required.     

Clinical features and surgical outcomes of lumbar spinal stenosis in patients aged 80 years or older: a multi-center retrospective study

Introduction

With increased aging of the population, spine surgeons have more opportunity to treat elderly patients for lumbar spinal stenosis (LSS). The purpose of this study was to clarify the clinical features and surgical outcomes for LSS in the elderly aged 80 years or older.

Materials and methods

We retrospectively reviewed 702 consecutive patients with LSS who underwent decompression surgery without fusion between 2006 and 2010. Patients with other conditions that could affect functional status were excluded from this study. Of the remaining 304 patients, 241 with LSS whose condition could be evaluated 6 months at least after surgery were analyzed. The mean follow-up period was 14.4 months (range 6–60 months). There were 144 males and 97 females aged 45–93 years old (average: 72.2 years old). Patients were divided into two age groups: 80 years or older (Group A, 46 patients) and under 80 years of age (Group B, 195 patients). We evaluated differences in the clinical features and surgical outcomes between the two groups.

Results

There were no significant differences in surgical levels, the number of operation levels, operation times, or the amount of intraoperative bleeding between Groups A and B. The percentages of patients with comorbidities were 73.9 % in Group A and 60.0 % in Group B, which were not significantly different. There were no significant differences in Japanese Orthopaedic Association scores preoperatively, 6 months postoperatively, and at the final follow-up between the two groups. Furthermore, recovery ratios 6 months postoperatively and at final follow-up were similar between the two groups. The percentages of patients with postoperative complications were 19.6 % in Group A and 13.3 % in Group B, which were not significantly different.

Conclusions

This multi-center retrospective study demonstrated that the benefits and risks of decompression surgery for LSS were similar between patients aged over 80 years and those under 80 years. Therefore, decompression surgery is a reasonable treatment even for elderly patients aged over 80 years.     

Remifentanil patient-controlled intravenous analgesia during labour: a retrospective observational study of 10 years’ experience

BackgroundIntravenous remifentanil patient-controlled analgesia (PCA) has been routinely available for labouring women in our unit since 2004, the regimen using a 40 µg bolus available two minutely on demand, continuous pulse oximetry and mandatory one-to-one care. We examined remifentanil use and compared, with the other analgesic options available in our unit, outcomes such as mode of delivery, Apgar scores, neonatal resuscitation and admission to the neonatal intensive care unit.MethodsWe retrospectively identified women who delivered in our unit between 2005 and 2014 and received remifentanil, diamorphine or epidural analgesia during labour. Data were drawn from the Northern Ireland Maternity System electronic database, which records birth details from all obstetric units in Northern Ireland. Additional data were identified from paper survey forms, completed by the midwife post delivery for all women who received remifentanil in our unit. Outcomes were compared between women who received remifentanil, diamorphine or an epidural technique for labour analgesia.ResultsOver the 10-year period, remifentanil was the most popular form of analgesia, being selected by 31.9% (8170/25617) women. Compared with women selecting diamorphine or epidural analgesia, those having remifentanil had similar rates of instrumental and operative delivery. Neonatal Apgar scores were also similar. Neonatal resuscitation or neonatal unit admission were not more likely in women choosing remifentanil PCA.ConclusionWe found remifentanil PCA to be neither less safe nor associated with poorer outcomes than other analgesic options offered in our unit, when used within our guidelines for more than a 10-year period.     

Nutritional status is associated with health-related quality of life in children with cystic fibrosis aged 9–19 years

BackgroundThe impact of improved nutritional status on health-related quality of life (HRQOL) is unknown for children with cystic fibrosis (CF).MethodsAssociations between nutritional status and HRQOL were examined over 2 years in 95 children, aged 9–19 years, who were followed in the Wisconsin Newborn Screening Project. HRQOL was assessed using the Cystic Fibrosis Questionnaire (CFQ). Associations between height z-score (HtZ), BMI z-score (BMIZ) and seven CFQ dimensions were evaluated.ResultsMean values of at least 80 were observed for all CFQ dimensions except respiratory symptoms and treatment burden. Treatment burden was significantly worse in patients with meconium ileus (57) compared to pancreatic insufficient (65) and sufficient (78) subjects, p < 0.0001. HtZ and BMIZ were positively associated with physical functioning and body image (p < 0.05).ConclusionsBetter nutritional status was associated with increased HRQOL scores. Early diagnosis through newborn screening and improved nutrition provides an opportunity to enhance quality of life and body image perception.     

Trends in trabecular architecture and bone mineral density distribution in 152 individuals aged 30–90 years

The strength of trabecular bone depends on its microarchitecture and its tissue level properties. However, the interrelation between these two determinants of bone quality and their relation to age remain to be clarified. Iliac crest bone cores (n = 152) from individuals aged 30–90 years were analyzed by quantitative backscattered electron imaging. Univariate and multivariate analyses were conducted to determine whether epidemiological parameters (age, sex or BMI), structural histomorphometrical variables (BV/TV, Tb.Th, Tb.N and Tb.Sp) and osteoid-related indices (OV/BV, OS/BS or O.Th) predict the degree of bone mineralization. While sex and BMI were not associated with bone mineralization, age was positively correlated with the most frequently occurring calcium concentrations (Ca peak), the percentage of highly mineralized bone areas (Ca high) and, in the case of adjusted covariates, also the mean calcium content (Ca mean). Bone volume fraction and trabecular thickness were both negatively correlated with Ca mean. However, trabecular thickness was additionally associated with Ca peak, Ca high as well as the amount of low mineralized bone (Ca low) and was the only structural parameter predicting bone mineralization independent of age. Furthermore, our analyses demonstrated that osteoid variables – within a normal range (< 2% OV/BV) – were significantly associated with all mineralization parameters and represent the only predictor for the mineralization heterogeneity (Ca width). Taken together, we showed that elevated trabecular bone mineralization correlates with aging and bone loss. However, these associations are attributable to trabecular thinning that comes along with high bone mineralization due to the loss of low mineralized bone surfaces. Therefore, we demonstrated that the degree of areally resolved bone mineral is primarily associated with the amount of physiological osteoid present and the thickness of mineralized bone in trabeculae.     

Effects of bone-specific physical activity,gender and maturity on tibial cross-sectional bone material distribution: a cross-sectional pQCT comparison of children and young adults aged 5–29 years

Growth is the opportune time to modify bone accrual. While bone adaptation is known to be dependent on local loading and consequent deformations (strain) of bone, little is known about the effects of sex, and bone-specific physical activity on location-specific cross-sectional bone geometry during growth. To provide more insight we examined bone traits at different locations around tibial cross sections, and along the tibia between individuals who vary in terms of physical activity exposure, sex, and pubertal status. Data from 304 individuals aged 5–29 years (172 males, 132 females) were examined. Peripheral quantitative computed tomography (pQCT) was applied at 4%, 14%, 38%, and 66% of tibial length. Maturity was established by estimating age at peak height velocity (APHV). Loading history was quantified with the bone-specific physical activity questionnaire (BPAQ). Comparisons, adjusted for height, weight and age were made between sex, maturity, and BPAQ tertile groups. Few to no differences were observed between sexes or BPAQ tertiles prior to APHV, whereas marked sexual dimorphism and differences between BPAQ tertiles were observed after APHV. Cross-sectional location-specific differences between BPAQ tertiles were not evident prior to APHV, whereas clear location-specificity was observed after APHV. In conclusion, the skeletal benefits of physical activity are location-specific in the tibia. The present results indicate that the peri- or post-pubertal period is likely a more favourable window of opportunity for enhancing cross-sectional bone geometry than pre-puberty. Increased loading during the peri-pubertal period may enhance the bone of both sexes.     

Safety and tolerability of subcutaneous PTHrP(1–36) in healthy human volunteers: a dose escalation study

Parathyroid hormone-related protein (PTHrP) is an anabolic skeletal agent in mice, rats and humans. In previous studies, we have demonstrated that PTHrP can be administered to osteoporotic postmenopausal women at a dose of 6.56 ug/kg/day (or approximately 400 ug/day) for 3 months to yield a 4.7% increase in lumbar spine BMD. This regimen was free of hypercalcemia or adverse effects. Moreover, PTHrP appeared to stimulate bone formation selectively, without stimulating bone resorption. This efficacy in the absence of adverse effects, as well as the apparent pure anabolic action of PTHrP, prompted us to attempt to define the complete therapeutic window for PTHrP. In this study, we gradually escalated the dose of PTHrP(1–36) from 9 to 28 ug/kg (or approximately 570 ug to 1,946 ug) administered as a single subcutaneous dose to 22 healthy young adult subjects. PTHrP(1–36) was well tolerated even at the highest dose, just under 2.0 mg, some five times higher than we have previously demonstrated to be effective in increasing bone mass, and some 100 times higher than the maximal approved dose of PTH(1–34). Despite the large dose of PTHrP, the highest serum calcium achieved was 10.6 mg/dl, and this was observed in only one subject at the highest dose. The mean serum calcium in subjects receiving the highest dose was 9.6 mg/dl. Only one subject experienced adverse symptoms/signs, and this was at the highest dose. We conclude that subcutaneous PTHrP(1–36) is safe when administered in single doses approaching 2.0 mg. These findings indicate that the therapeutic window for PTHrP(1–36) in humans is wide and permit the design and implementation of longer safety and efficacy trials.This study was supported by NIH grants DK 51081 and RR 00056, The University of Pittsburgh General Clinical Research Center and the Multiple Myeloma Research Foundation. Dr Stewart is CEO of Osteotrophin, LLC.     

The effects of being habitually barefoot on foot mechanics and motor performance in children and adolescents aged 6–18 years: study protocol for a multicenter cross-sectional study (Barefoot LIFE project)

Background

Barefoot locomotion has evoked an increasing scientific interest with a controversial debate about benefits and limitations of barefoot and simulated barefoot walking and running. While most current knowledge comes from cross sectional laboratory studies, the evolutionary perspective suggests the importance of investigating the long-term effects. Observing habitually barefoot populations could fill the current gap of missing high quality longitudinal studies. Therefore, the study described in this design paper aims to investigate the effects of being habitually barefoot on foot mechanics and motor performance of children and adolescents.

Methods

This study has a cross-sectional, binational design and is part of the “Barefoot Locomotion for Individual Foot- and health Enhancement (Barefoot LIFE)” project. Two large cohorts (n_(total)?=?520) of healthy children and adolescents between 6 and 18 years of age will be included respectively in Germany and South Africa. A barefoot questionnaire will be used to determine habitually barefoot individuals. The testing will be school-based and include foot mechanical (static arch height index, dynamic arch index, foot pliability) and motor performance (coordination, speed, leg power) outcomes. Gender, BMI and level of physical activity will be considered for confounding.

Discussion

The strength of this study is the comparison of two large cohorts with different footwear habits to determine long-term effects of being habitually barefoot on foot mechanics and motor performance.

     

Kidney growth in 717 healthy children aged 0–18 months: a longitudinal cohort study

Kidney size is an important parameter in the evaluation of children with renal disease. However, reference materials for kidney size in healthy children have been limited beyond the neonatal period. We performed a longitudinal cohort study of 717 healthy children born at term with normal birth weight. Kidney size and shape were determined by ultrasonography and related to gender, age, and body size (weight, length, body surface area, skinfold thickness) at 0, 3, and 18 months of age. Gender-differentiated reference charts were established. Boys had significantly larger kidney volumes than girls (P<0.001) and larger relative volumes (kidney volume/weight) at 0 and 3 months (P<0.001), but not at 18 months of age. The best single predictor of gender-differentiated kidney volume was weight. Relative kidney volume changed with increasing age and height in a two-phase pattern: an initial decrease until a height of 65–70 cm was reached followed by a stable level. In conclusion, kidney size was significantly influenced by gender, age, and body composition. Relative kidney volume decreased with increasing age and height in a two-phase pattern. These characteristic changes in kidney volume indicated that infant kidney growth might be influenced by sex steroids and growth hormone in addition to body composition.     

The 95% effective dose of intranasal dexmedetomidine sedation for pulmonary function testing in children aged 1–3 years: A biased coin design up-and-down sequential method

Study objectiveIntranasal dexmedetomidine (DEX) can provide adequate sedation during short examinations in children. However, we found no data regarding the 95% effective dose (ED₉₅) of intranasal DEX for children's pulmonary function testing (PFT).DesignProspective study and a biased coin design up-and-down sequential method.SettingSedation center of Children's Hospital of Chongqing Medical University.PatientsChildren aged 1–3 years undergoing pulmonary function testing.InterventionThe dose of DEX for each subsequent patient was determined by the response of the previous patient with the biased coin design up-and-down sequential method with an interval of 0.25 μg∙kg⁻¹.MeasurementsChildren aged 1–3 years who received pulmonary function testing were involved in this dose-finding trial. Intranasal DEX started at a dose of 2 μg∙kg⁻¹ on the first patient. The dose of DEX for each subsequent patient was determined by the response of the previous patient with the biased coin design up-and-down sequential method with an interval of 0.25 μg∙kg⁻¹. The sedation was assessed by the Modified Observer Assessment of Alertness and Sedation (MOAA/S) scale, and recovery was assessed by the modified Aldrete recovery score. The ED₉₅ was calculated using isotonic regression. Other variables, including the sedation onset time, examination time, wake-up time, blood pressure (BP), heart rate (HR), respiratory rate (RR), and oxyhaemoglobin desaturation (SpO₂), were recorded. Adverse events such as hypotension, bradycardia, respiration depression, oxyhaemoglobin desaturation, regurgitation and vomiting were recorded.Main resultsA total of 68 children were enrolled for the study; 62 children had successful sedation, and 6 had failed sedation. The ED₉₅ of intranasal DEX was estimated to be 2.64 μg∙kg⁻¹ [95% confidence interval (CI), 2.49–2.87 μg∙kg⁻¹]. The sedation onset time for all patients was 15.0 (12.3–19.0) min. The sedation onset time of successful sedation patients was 15.0 (12.0–19.0) min, the sedation onset time of failed sedation patients was 16.0 (15.0–27.8) min, the examination time was 8 (7–10) min, and the wake-up time was 40 (35–43) min. There were no adverse events during the whole procedure.ConclusionThe ED₉₅ of intranasal DEX sedation in children aged 1–3 years undergoing PFT was 2.64 μg∙kg⁻¹.     

Safety and effectiveness of 1-stage conversion of adjustable gastric band-to-sleeve gastrectomy: a single-institution case–control study

BackgroundPatients are increasingly referred for conversion of laparoscopic adjustable gastric band (LAGB) to laparoscopic Roux-en-Y gastric bypass (LRYGB) or sleeve gastrectomy (SG). The safety of a 1- versus 2-stage approach to this revision is debated.ObjectivesWe examined the safety and efficacy of 1-stage conversion of LAGB to SG at our institution.SettingUniversity hospital.MethodsAn institutional database was used to retrospectively identify patients who underwent single-stage LAGB-to-SG conversion between 2010 and 2018. Patients were matched 1:1 for age, sex, and body mass index with primary SG patients during this same period. Primary endpoints were operative time, complication rate, length of hospital say, and weight loss 12 months from surgery.ResultsTwo-hundred and twenty-nine patients undergoing conversion of LAGB to SG were identified. Median postoperative length of hospital stay was 2 days. Two patients (.8%) developed surgical site infection. One patient (.4%) developed a postoperative myocardial infarction. There were 4 total readmissions (1.7%) and 1 reoperation within 30 days (.4%). There were no statistically significant differences in 30-day complication rates between groups. Weight loss at 12 months was significantly different: Median body mass index loss for conversion patients was 5.1 kg/m² compared with 8.85 kg/m² for patients in the primary SG group (P < .0001).ConclusionSingle-stage conversion of LAGB to SG is safe and effective. Patients may not experience the same extent of weight loss as those with primary SG. Our findings represent the largest single-institutional experience to date and support a 1-stage approach whenever feasible.     

Longitudinal changes in lean mass predict pQCT measures of tibial geometry and mineralisation at 6–7 years

BackgroundStudies in childhood suggest that both body composition and early postnatal growth are associated with bone mineral density (BMD). However, little is known of the relationships between longitudinal changes in fat (FM) and lean mass (LM) and bone development in pre-pubertal children. We therefore investigated these associations in a population-based mother-offspring cohort, the Southampton Women's Survey.MethodsTotal FM and LM were assessed at birth and 6–7 years of age by dual-energy x-ray absorptiometry (DXA). At 6–7 years, total cross-sectional area (CSA) and trabecular volumetric BMD (vBMD) at the 4% site (metaphysis) of the tibia was assessed using peripheral quantitative computed tomography [pQCT (Stratec XCT-2000)]. Total CSA, cortical CSA, cortical vBMD and strength–strain index (SSI) were measured at the 38% site (diaphysis). FM, LM and bone parameters were adjusted for age and sex and standardised to create within-cohort z-scores. Change in LM (ΔLM) or FM (ΔFM) was represented by change in z-score from birth to 7 years old and conditioned on the birth measurement. Linear regression was used to explore the associations between ΔLM or ΔFM and standardised pQCT outcomes, before and after mutual adjustment and for linear growth. The β-coefficient represents SD change in outcome per unit SD change in predictor.ResultsDXA at birth, in addition to both DXA and pQCT scans at 6–7 years, were available for 200 children (48.5% male). ΔLM adjusted for ΔFM was positively associated with tibial total CSA at both the 4% (β = 0.57SD/SD, p < 0.001) and 38% sites (β = 0.53SD/SD, p < 0.001), cortical CSA (β = 0.48SD/SD, p < 0.001) and trabecular vBMD (β = 0.30SD/SD, p < 0.001), but not with cortical vBMD. These relationships persisted after adjustment for linear growth. In contrast, ΔFM adjusted for ΔLM was only associated with 38% total and cortical CSA, which became non-significant after adjustment for linear growth.ConclusionIn this study, gain in childhood LM was positively associated with bone size and trabecular vBMD at 6–7 years of age. In contrast, no relationships between change in FM and bone were observed, suggesting that muscle growth, rather than accrual of fat mass, may be a more important determinant of childhood bone development.     

Comparison of retrograde intrarenal surgery and mini-percutaneous nephrolithotomy in management of lower-pole renal stones with a diameter of smaller than 15 mm

The aim of this study was to compare the outcomes of retrograde intrarenal surgery (RIRS) and miniaturized percutaneous nephrolithotomy (mini-PNL) in management of lower-pole renal stones with a diameter smaller than 15 mm. Between December 2009 and July 2012, the patients with the diagnosis of lower-pole stones were evaluated by ultrasonography, intravenous pyelography and computed tomography. The records of 73 evaluable patients who underwent mini-PNL (n = 37) or RIRS (n = 36) for lower-pole (LP) stones with diameter smaller than 15 mm were reviewed retrospectively. Of the 73 patients, 37 underwent mini-PNL and 36 underwent RIRS. The stone-free rates were 89.1 and 88.8 % for mini-PNL and RIRS groups, respectively. The mean operation time was 53.7 ± 14.5 in the mini-PNL group but 66.4 ± 15.8 in the RIRS group (P = 0.01). The mean fluoroscopy times and hospitalization times were significantly higher in the mini-PNL group. There was no major complication in any patient. RIRS and mini-PNL are safe and effective methods for treatment of LP calculi with a diameter smaller than 15 mm. RIRS is a non-invasive and feasible treatment option, and has also short hospitalization time, low morbidity and complication rate. It may be an alternative of mini-PNL in the treatment LP calculi with smaller than 15 mm.