A snapshot into the future of image-guided surgery for renal cancer

Robot-assisted partial nephrectomy(RAPN)is certainly one of the most fascinating and complex urological procedures.This is ascribable to its vast heterogeneity from one case to another,related to patient’s anatomical variability and tumour’s characteristics.Over the last years,with the aim to assist the surgeons in handling ever more difficult lesions(totally endophytic or large volume[1,2])suitable for RAPN,several technologies were proposed and tested,from preoperative planning to intraoperative assistance or navigation[3].

Real-time fluorescence image-guided gastrointestinal oncologic surgery:Towards a new era

Technological improvements are crucial in the evolution of surgery.Real-time fluorescence-guided surgery(FGS)has spread worldwide,mainly because of its usefulness during the intraoperative decision-making processes.The success of any gastrointestinal oncologic resection is based on the anatomical identification of the primary tumor and its regional lymph nodes.FGS allows also to evaluate the blood perfusion at the gastrointestinal stumps after colorectal or esophageal resections.Therefore,a reduction on the anastomotic leak rates has been postulated as one of the foreseeable benefits provided by the use of FGS in these procedures.Although the use of fluorescence in lymph node detection was initially described in breast cancer surgery,the technique is currently applied in gastric or splenic flexure cancers,as they both present complex and variable lymphatic drainages.FGS allows also to perform intraoperative lymphograms or sentinel lymph node biopsies.New applications of FGS are being developed to assist in the detection of peritoneal metastases or in the evaluation of the tumor resection margins.The present review aims to provide a general overview of the current status of real-time FGS in gastrointestinal oncologic surgery.We put a special focus on the different applications of FGS,discussing the main findings and limitations found in the contemporary literature and also the promising near future applications.

A facile phototheranostic nanoplatform integrating NIR-Ⅱ fluorescence/PA bimodal imaging and image-guided surgery/PTT combinational therapy for improved antitumor efcacy

Phototheranostic with highly integrated functions is an attractive platform for cancer management. It remains challenging to develop a facile phototheranostic platform with complementary bimodal imaging and combinational therapy capacity. Herein, the small-molecule cyanine IR780 loaded liposomes have been harnessed as a nanoplatform to simultaneously realize photoacoustic(PA)/the second near-infrared window(NIR-Ⅱ) fluorescence imaging and image-guided surgery/adjuvant photothermal therapy(PTT).This nanoplatform exhibits attractive properties like uniform controllable size, stable dispersibility, NIR-Ⅱ fluorescence emission, photothermal conversion, and biocompatibility. Benefiting from the complementary PA/NIR-Ⅱ fluorescence bimodal imaging, this nanoplatform was successfully applied in precise vasculature delineation and tumor diagnosis. Interestingly, the tumor was clearly detected by NIR-Ⅱ fluorescence imaging with the highest tumor-to-normal-tissue ratio up to 12.69, while signal interference from the liver was significantly reduced, due to the difference in the elimination rate of the nanoplatform in the liver and tumor. Under the precise guidance of the image, the tumor was accurately resected, and the simulated residual lesion after surgery was completely ablated by adjuvant PTT. This combined therapy showed improved antitumor efcacy over the individual surgery or PTT. This work develops a facile phototheranostic nanoplatform with great significance in accurately diagnosing and effectively treating tumors using simple NIR light irradiation.

Image-guided lens extraction surgery: a systematic review

A systematic review of the recent literature regarding the current image-guided systems used for cataract surgery or refractive lens exchange was performed based on the PubMed and Google Scholar databases in March 2018. Literature review returned 21 eligible studies. These studies compared image-guided systems with other keratometric devices regarding their accuracy, repeatability and reproducibility in measurement of keratometric values, astigmatism magnitude and axis, as well as in IOL power calculation. Additionally, the image-guided systems were compared with conventional manual ink-marking techniques for the alignment of toric IOLs. In conclusion, image-guided systems seem to be an accurate and reliable technology with measurements of high repeatability and reproducibility regarding the keratometry and IOL power calculation, but not yet interchangeable with the current established and validated keratometric devices. However, they are superior over the conventional manual inkmarking techniques for toric IOL alignment.

New direction for surgery:Super minimally invasive surgery

The top goal of modern medicine is treating disease without destroying organ structures and making patients as healthy as they were before their sickness.Minimally invasive surgery(MIS)has dominated the surgical realm because of its lesser invasiveness.However,changes in anatomical structures of the body and reconstruction of internal organs or different organs are common after traditional surgery or MIS,decreasing the quality of life of patients post-operation.Thus,I propose a new treatment mode,super MIS(SMIS),which is defined as“curing a disease or lesion which used to be treated by MIS while preserving the integrity of the organs”.In this study,I describe the origin,definition,operative channels,advantages,and future perspectives of SMIS.

Indocyanine green:The guide to safer and more effective surgery

In this editorial we comment on the article by Kalayarasan and co-workers published in the recent issue of the World Journal of Gastrointestinal Surgery.The authors present an interesting review on the use of indocyanine green fluo-rescence in different aspects of abdominal surgery.They also highlight future perspectives of the use of indocyanine green in mini-invasive surgery.Indo-cyanine green,used for fluorescence imaging,has been approved by the Food and Drug Administration and is safe for use in humans.It can be administered in-travenously or intra-arterially.Since its advent,there have been several advance-ments in the applications of indocyanine green,especially in the surgical field,such as intraoperative mapping and biopsy of sentinel lymph node,measurement of hepatic function prior to resection,in neurosurgical cases to detect vascular anomalies,in cardiovascular cases for patency and assessment of vascular ab-normalities,in predicting healing following amputations,in helping visualization of hepatobiliary anatomy and blood vessels,in reconstructive surgery,to assess flap viability and for the evaluation of tissue perfusion following major trauma and burns.For these reasons,the intraoperative use of indocyanine green has become common in a variety of surgical specialties and transplant surgery.Co-lorectal surgery has just lately begun to adopt this technique,particularly for perfusion visualization to prevent anastomotic leakage.The regular use of in-docyanine green coupled with fluorescence angiography has recently been pro-posed as a feasible tool to help improve patient outcomes.Using the best available data,it has been shown that routine use of indocyanine green in colorectal surgery reduces the rates of anastomotic leak.The use of indocyanine green is proven to be safe,feasible,and effective in both elective and emergency scenarios.However,additional robust evidence from larger-scale,high-quality studies is essential before incorporating indocyanine green guided surgery into standard practice.

Parallel pathways:A chronicle of evolution in rectal and breast cancer surgery

In this editorial,we have analyzed the historical evolution of rectal and breast cancer surgery,focusing on the progressive reduction of demolitive approaches and the increasing use of more conservative strategies,accompanied by a growing emphasis on perioperative treatments aimed at enhancing surgical outcomes.All of these changes have been made possible due to an increased awareness and understanding of oncological diseases and improved perioperative treatments.

Artificial Intelligence and Computer Vision during Surgery: Discussing Laparoscopic Images with ChatGPT4—Preliminary Results

Introduction: Ultrafast latest developments in artificial intelligence (ΑΙ) have recently multiplied concerns regarding the future of robotic autonomy in surgery. However, the literature on the topic is still scarce. Aim: To test a novel AI commercially available tool for image analysis on a series of laparoscopic scenes. Methods: The research tools included OPENAI CHATGPT 4.0 with its corresponding image recognition plugin which was fed with a list of 100 laparoscopic selected snapshots from common surgical procedures. In order to score reliability of received responses from image-recognition bot, two corresponding scales were developed ranging from 0 - 5. The set of images was divided into two groups: unlabeled (Group A) and labeled (Group B), and according to the type of surgical procedure or image resolution. Results: AI was able to recognize correctly the context of surgical-related images in 97% of its reports. For the labeled surgical pictures, the image-processing bot scored 3.95/5 (79%), whilst for the unlabeled, it scored 2.905/5 (58.1%). Phases of the procedure were commented in detail, after all successful interpretations. With rates 4 - 5/5, the chatbot was able to talk in detail about the indications, contraindications, stages, instrumentation, complications and outcome rates of the operation discussed. Conclusion: Interaction between surgeon and chatbot appears to be an interesting frontend for further research by clinicians in parallel with evolution of its complex underlying infrastructure. In this early phase of using artificial intelligence for image recognition in surgery, no safe conclusions can be drawn by small cohorts with commercially available software. Further development of medically-oriented AI software and clinical world awareness are expected to bring fruitful information on the topic in the years to come.

Does enhanced recovery after surgery programs improve clinical outcomes in liver cancer surgery?

Enhanced recovery after surgery(ERAS)programs have been widely applied in liver surgery since the publication of the first ERAS guidelines in 2016 and the new recommendations in 2022.Liver surgery is usually performed in oncological patients(liver metastasis,hepatocellular carcinoma,cholangiocarcinoma,etc.),but the real impact of liver surgery ERAS programs in oncological outcomes is not clearly defined.Theoretical advantages of ERAS programs are:ERAS decreases postoperative complication rates and has been demonstrated a clear relationship between complications and oncological outcomes;a better and faster posto-perative recovery should let oncologic teams begin chemotherapeutic regimens on time;prehabilitation and nutrition actions before surgery should also improve the performance status of the patients receiving chemotherapy.So,ERAS could be another way to improve our oncological results.We will discuss the literature about liver surgery ERAS focusing on its oncological implications and future investigations projects.

Transurethral prostate surgery in prostate cancer patients: A population-based comparative analysis of complication and mortality rates

Objective:Prostate cancer(PCa)patients might experience lower urinary tract symptoms as those diagnosed with benign prostatic hyperplasia(BPH).Some of them might be treated for their lower urinary tract symptoms instead of PCa.We aimed to test the effect of PCa versus BPH on surgical outcomes after transurethral prostate surgery,namely complication and mortality rates.Methods:Within the American College of Surgeons National Surgical Quality Improvement Program database(2011-2016),we identified patients who underwent transurethral resection of the prostate,photoselective vaporization,or laser enucleation.Patients were stratified according to postoperative diagnosis(PCa vs.BPH).Univariable and multivariable logistic regression models evaluated the predictors of perioperative morbidity and mortality.A formal test of interaction between diagnosis and surgical technique used was performed.Results:Overall,34542 patients were included.Of all,2008(5.8%)had a diagnosis of PCa.The multivariable logistic regression model failed to show statistically significant higher rates of postoperative complications in PCa patients(odds ratio:0.9,95%confidence interval:0.7-1.1;p=0.252).Moreover,similar rates of perioperative mortality(p=0.255),major acute cardiovascular events(p=0.581),transfusions(p=0.933),and length of stay of more than or equal to 30 days(p=0.174)were found.Additionally,all tests failed to show an interaction between post-operative diagnosis and surgical technique used.Conclusion:Patients diagnosed with PCa do not experience higher perioperative morbidity or mortality after transurethral prostate surgery when compared to their BPH counterparts.Moreover,the diagnosis seems to not influence surgical technique outcomes.

Results of the First 10 Cases of Coronary Bypass Surgery in Senegal

This is a review of the first 10 coronary artery bypass surgeries performed by the local team. The mean age was 62 years old [45 - 74]. The patients were predominantly male, with a M/F ratio of 4:1. Cardiovascular risk factors were mainly myocardial infarction (MI) (60%), hypertension (50%), obesity (40%) and diabetes (30%), with at least two risk factors per patient. Angina was the main symptom (80%). The average time from presentation to surgery was 8 months. The mean Euroscore 2 was 2.92 ± 1.65 [1.33 - 6.60]. Coronary angiography revealed an average of 2 lesions per patient, with 3-vessel involvement in 70% of cases: the Interventricular artery (IVA) (100%), the right coronary artery (90%) and the circumflex artery (70%). On echocardiography, the mean Left ventricular ejection fraction (LVEF) was 59% [33% - 76%]. All patients underwent median sternotomy with bypass grafting. The average duration of the cardiopulmonary bypass was 150 min [46 - 275 min];that of aortic clamping, 120 min [43 - 232 min]. The grafts used were internal thoracic artery (ITA) in 100% of cases (80% on the left and 20% on the right), and the great saphenous vein (GSV) in 60% of cases (50% on the left and 10 on the right). Double bypass was performed in 60% of cases, single bypass in 30% and triple bypass in 10%. The bypasses were performed on the IVA (100%), the middle lateral of the circumflex (30%) and the bisector (20%). The average time to extubation was 11 hours and the length of stay in the intensive care unit was 7 days [03 - 17 days]. One patient had a reoperation on Day 0 post-op. The average hospital stay was 13 days [06 - 27 days]. Complications occurred in nine of the patients (90%), with a predominance of infectious and neurological complications. Overall operative mortality was 3%, all in intensive care.

Don’t forget emergency surgery! Lessons to learn from elective indocyanine green-guided gastrointestinal interventions

Fluorescence-based imaging has found application in several fields of elective surgery,but there is still a lack of evidence in the literature about its use in the emergency setting.Clinical trials have consistently shown that indocyanine green(ICG)-guided surgery can dramatically reduce the risk of postoperative complic-ations,length of in-hospital stay and total healthcare costs in the elective setting.It is well-known that emergency surgery has a higher complication rate than its elective counterpart,therefore an impelling need for research studies to explore,validate and develop this issue has been highlighted.The present editorial aims to provide a critical overview of currently available applications and pitfalls of ICG fluorescence in abdominal emergencies.Furthermore,we evidenced how the experience of ICG-fluorescence in elective surgery might be of great help in implementing its use in acute situations.In the first paragraph we analyzed the tips and tricks of ICG-guided cancer surgery that might be exploited in acute cases.We then deepened the two most described topics in ICG-guided emergency surgery:Acute cholecystitis and intestinal ischemia,focusing on both the advantages and limitations of green-fluorescence application in these two fields.In emergency situations,ICG fluorescence demonstrates a promising role in preventing undue intestinal resections or their entity,facilitating the detection of intestinal ischemic zones,identifying biliary tree anatomy,reducing post-operative complications,and mitigating high mortality rates.The need to improve its application still exists,therefore we strongly believe that the elective and routinary use of the dye is the best way to acquire the necessary skills for emer-gency procedures.

Congenital Heart Disease Referred for Surgery: Analysis and Epidemiological Description in the Cardiology Department of CHU Ignace Deen

Introduction: Congenital heart disease includes all cardiac and vascular malformations. It accounts for approximately one third of all congenital malformations and is a public health problem, particularly in developing countries. The aim of this study was to analyze the epidemiological, clinical and paraclinical aspects of congenital heart disease. Methods: This was a retrospective descriptive and analytical study based on the records of 135 patients referred for surgery and followed up in the cardiology department of the Ignace Deen University Hospital, collected in November 2022. Results: Hospital prevalence was 5%. The mean age was 71 months, ranging from 1 month to 19 years. The age group over 24 months was the most represented (62%). The M/F sex ratio was 1.36. Urban origin was predominant (58%). The rate of children not attending school or dropping out was high (16%). Siblings with fewer than 4 children were the most common (88%). A heart murmur was the most frequent sign (78%), followed by cyanosis (36%) and heart failure (29%). The association between heart murmurs and CHD was proven with a p-value Conclusion: CHDs represent the main indication for paediatric cardiac surgery and follow-up (95%). We stress the importance of implementing a screening and management strategy for congenital heart disease.

Are there sex-based disparities in cataract surgery?

AIM:To investigate sex-based differences in the occurrence of intra-operative and post-operative complications and associated visual outcomes following cataract surgery.METHODS:This was a retrospective study of patients who had phacoemulsification cataract surgery at the University of Colorado School of Medicine.Data collected included the patient’s health history,ocular comorbidities,operative and post-operative complications,and the post-operative best corrected visual acuity(BCVA).The data were analyzed using univariate and multivariable logistic regression with generalized estimating equations to account for the correlation of some patients having two eyes included in the study.RESULTS:A total of 11977 eyes from 7253 patients were included in the study.Ocular comorbidities differed by sex,with males having significantly higher percentages of traumatic cataracts(males 0.7%vs females 0.1%),prior ocular surgery(6.7%vs 5.5%),and mature cataracts(2.8%vs 1.9%).Conversely,females had significantly higher rates of pseudoexfoliation(2.0%vs 3.2%).In unadjusted analysis,males had higher rates of posterior capsular rupture(0.8%vs 0.4%)and vitreous loss(1.0%vs 0.6%),but this difference was not significant after adjustment for confounders.Males had a significantly increased risk of post-operative retinal detachment,but in multivariable analysis this was no longer significant.Males were significantly less likely to undergo post-operative neodymium-doped yttrium aluminum garnet(Nd:YAG)laser capsulotomy for posterior capsule opacification(OR=0.8,95%CI=0.7-0.9,P=0.0005).The BCVA was slightly worse for males pre-operatively;but post-operatively,both sexes exhibited similar visual acuity of Snellen equivalent 20/25.CONCLUSION:The study finds that in a cohort of patients presenting for cataract surgery,sex differences exist in pre-operative comorbidities and surgical characteristics that contribute to higher rates of some complications for males.However,observed surgical complication rates exhibit almost no difference by sex after adjusting for pre-operative differences and post-operative BCVA is similar between sexes.

Identification of clinical subphenotypes of sepsis after laparoscopic surgery

Objective:Some patients exhibit septic symptoms following laparoscopic surgery,leading to a poor prognosis.Effective clinical subphenotyping is critical for guiding tailored therapeutic strategies in these cases.By identifying predisposing factors for postoperative sepsis,clinicians can implement targeted interventions,potentially improving outcomes.This study outlines a workflow for the subphenotype methodology in the context of laparoscopic surgery,along with its practical application.Methods:This study utilized data routinely available in clinical case systems,enhancing the applicability of our findings.The data included vital signs,such as respiratory rate,and laboratory measures,such as blood sodium levels.The process of categorizing clinical routine data involved technical complexities.A correlation heatmap was used to visually depict the relationships between variables.Ordering points were used to identify the clustering structure and combined with Consensus K clustering methods to determine the optimal categorization.Results:Our study highlighted the intricacies of identifying clinical subphenotypes following laparoscopic surgery,and could thus serve as a valuable resource for clinicians and researchers seeking to explore disease heterogeneity in clinical settings.By simplifying complex methodologies,we aimed to bridge the gap between technical expertise and clinical application,fostering an environment where professional medical knowledge is effectively utilized in subphenotyping research.Conclusion:This tutorial could primarily serve as a guide for beginners.A variety of clustering approaches were explored,and each step in the process contributed to a comprehensive understanding of clinical subphenotypes.

Study of Hemorrhoid Disease in the Department of General Surgery of the Cs Ref of the Commune I Bamako

This work was a retrospective prospective study carried out in the general surgery department of the Cs ref of commune I from January 2009 to December 2012. Our study aimed to determine the hospital frequency of hemorrhoidal disease, to identify the contributing factors, describe the clinical and therapeutic aspects and analyze the surgical consequences. We collected 73 patients with an average age of 37.8 years (range: 19 years and 77 years) with a sex ratio of 2.5 in favor of men. We operated on 49 patients or 67.1% of cases. 71.2% of our patients were married and lived in Bamako. Schoolchildren and middle managers made up 39.8% of cases. 82.2% of patients were seen in ordinary consultation and 69.9% complained of progressive anal pain in 66.7% of cases. This pain was triggered by defecation in 88.2% of our patients. The contributing factors were dominated by constipation (53.4%), working in a seated position (41.1%) and a sedentary lifestyle (16.4%) of cases. Stage IV external hemorrhoids and hemorrhoidal thrombosis represented 53.8% of surgical indications. The most used surgical technique was that of Milligan-Morgan, i.e. 51.9% of cases and 45.2% of patients treated medically received a combination of transit regulator, venotonics and analgesics. The surgical aftermath was marked by hemorrhage (3 cases), delayed healing (5 cases), urinary retention (1 case) and scarring anal stenosis (1 case). The morbidity rate was 5.48% of cases and a zero mortality rate. The average length of hospitalization was 2 days with extremes of 1 and 5 days.

First experience in laparoscopic surgery in low and middle income countries: A systematic review

BACKGROUND Laparoscopic surgery has reduced morbidity and mortality rates,shorter post-operative recovery periods and lower complication rates than open surgery.It is routine practice in high-income countries and is becoming increasingly common in countries with limited resources.However,introducing laparoscopic surgery in low-and-middle-income countries(LMIC)can be expensive and requires resour-ces,equipment,and trainers.AIM To report the challenges and benefits of introducing laparoscopic surgery in LMIC as well as to identify solutions to these challenges for countries with limited finances and resources.METHODS MEDLINE,EMBASE and Cochrane databases were searched for studies reporting first experience in laparoscopic surgery in LMIC.Included studies were published between 1996 and 2022 with full text available in English.Exclusion criteria were studies considering only open surgery,ear,nose,and throat,endoscopy,arthro-scopy,hysteroscopy,cystoscopy,transplant,or bariatric surgery.RESULTS Ten studies out of 3409 screened papers,from eight LMIC were eligible for inclusion in the final analysis,totaling 2497 patients.Most reported challenges were related to costs of equipment and training programmes,equipment pro-blems such as faulty equipment,and access to surgical kits.Training-related challenges were reliance on foreign trainers and lack of locally trained surgeons and theatre staff.The benefits of introducing laparoscopic surgery were economic and clinical,including a reduction in hospital stay,complications,and morbidi-ty/mortality.The introduction of laparoscopic surgery also provided training opportunities for junior doctors.CONCLUSION Despite financial and technical challenges,many studies emphasise the overall benefit of introducing laparoscopic surgery in LMICs such as reduced hospital stay and the related lower cost for patients.While many of the clinical centres in LMICs have proposed practical solutions to the challenges reported,more support is critically required,in particular regarding training.

Robotic Surgery: An Effective Treatment Option for Epiphrenic Diverticulum Associated with Nutcracker Esophagus

Background: Epiphrenic Diverticulum is frequently associated with esophageal motility disorders, such as nutcrackers esophagus. The diagnosis is usually made using imaging studies such as a Barium esophagogram, and esophageal manometry. Surgical treatment options for epiphrenic diverticulum and EN include diverticulectomy and wide myotomy. Aim: The resection of three epiphrenic diverticula and extensive myotomy were performed by robotic thoracoscopy uneventfully. Case presentation: A 65-year-old female complaining of dysphagia for solid foods, Chest pain and regurgitation. Esophagogastroduodenoscopy (EDG) with difficulty in advancing the endoscope at 25 cm and demonstrating an ED, no hiatal hernia and normal stomach and duodenum. Barium Esophagogram showed multiple diverticula and tortuosity throughout the esophagus. Conclusion: With robotic surgery, surgeons can perform highly precise operations with enhanced 3D vision and control. Through this cutting-edge approach, the treatment of ED associated with EN can be drastically changed, promising better outcomes for patients.

Defining minimal invasive surgical therapy for benign prostatic obstruction surgery: Perspectives from a global knowledge, attitude, and practice survey

Objective:To scrutinize the definitions of minimal invasive surgical therapy(MIST)and to investigate urologists’knowledge,attitudes,and practices for benign prostatic obstruction surgeries.Methods:A 36-item survey was developed with a Delphi method.Questions on definitions of MIST and attitudes and practices of benign prostatic obstruction surgeries were included.Urologists were invited globally to complete the online survey.Consensus was achieved when more than or equal to 70%responses were“agree or strongly agree”and less than or equal to 15%responses were“disagree or strongly disagree”(consensus agree),or when more than or equal to 70%responses were“disagree or strongly disagree”and less than or equal to 15%responses were“agree or strongly agree”(consensus disagree).Results:The top three qualities for defining MIST were minimal blood loss(n=466,80.3%),fast post-operative recovery(n=431,74.3%),and short hospital stay(n=425,73.3%).The top three surgeries that were regarded as MIST were Urolift®(n=361,62.2%),Rezum®(n=351,60.5%),and endoscopic enucleation of the prostate(EEP)(n=332,57.2%).Consensus in the knowledge section was achieved for the superiority of Urolift®,Rezum®,and iTIND®over transurethral resection of the prostate with regard to blood loss,recovery,day surgery feasibility,and post-operative continence.Consensus in the attitudes section was achieved for the superiority of Urolift®,Rezum®,and iTIND®over transurethral resection of the prostate with regard to blood loss,recovery,and day surgery feasibility.Consensus on both sections was achieved for EEP as the option with the better symptoms and flow improvement,lower retreatment rate,and better suitable for prostate more than 80 mL.Conclusion:Minimal blood loss,fast post-operative recovery,and short hospital stay were the most important qualities for defining MIST.Urolift®,Rezum®,and EEP were regarded as MIST by most urologists.

Multi-aspect analysis of ureteral access sheath usage in retrograde intrarenal surgery: A RIRSearch group study

Objective:To evaluate the effect of ureteral access sheath(UAS)use and calibration change on stone-free rate and complications of retrograde intrarenal surgery(RIRS).Methods:Data from 568 patients undergoing RIRS for kidney or upper ureteral stones were retrospectively included.Firstly,patients were compared after 1:1 propensity score matching,according to UAS usage during RIRS(UAS used[+]87 and UAS non-used[−]87 patients).Then all UAS+patients(n=481)were subdivided according to UAS calibration:9.5-11.5 Fr,10-12 Fr,11-13 Fr,and 13-15 Fr.Primary outcomes of the study were the success and complications of RIRS.Results:Stone-free rate of UAS+patients(86.2%)was significantly higher than UAS−patients(70.1%)after propensity score matching(p=0.01).Stone-free rate increased with higher caliber UAS(9.5-11.5 Fr:66.7%;10-12 Fr:87.0%;11-13 Fr:90.6%;13-15 Fr:100%;p<0.001).Postoperative complications of UAS+patients(11.5%)were significantly lower than UAS−patients(27.6%)(p=0.01).Complications(8.7%)with 9.5-11.5 Fr UAS was lower than thicker UAS(17.2%)but was not statistically significant(p=0.09).UAS usage was an independent factor predicting stone-free status or peri-and post-operative complications(odds ratio[OR]3.654,95%confidence interval[CI]1.314-10.162;OR 4.443,95%CI 1.350-14.552;OR 4.107,95%CI 1.366-12.344,respectively).Conclusion:Use of UAS in RIRS may increase stone-free rates,which also increase with higher caliber UAS.UAS usage may reduce complications;however,complications seemingly increase with higher UAS calibration.