Partial Staghorn Research Articles

Assessment of complications and success rates of Percutaneous nephrolithotomy: single tract vs. multi tract approaches.

The objective of this study was to assess the success and complication rates of single-tract access vs. multi-tract percutaneous nephrolithotomy (PNL). The medical records of consecutive patients who underwent PNL for staghorn, partial staghorn, and complex kidney stones between 2014 and 2022 were retrospectively reviewed. The demographic data, stone volumes, fluoroscopy and operation durations, changes in hemoglobin levels, numbers of blood transfusions, stone-free rates, perioperative complications, duration of nephrostomy removal, and length of hospital stay parameters were noted. The complications and complexity of PNL were graded using the modified Clavien and Guy's stone scores, respectively. Single and multi-tract subgroups were determined based on PNL access strategy and the subgroups were analyzed. The study involved 208 patients, with 158 in the single-tract group and 50 in the multi-tract group. The groups were comparable in age, ASA scores, and comorbidities (p > 0.05). The characteristics of the stones, such as their location, size, and density, did not show any significant differences between the groups (p > 0.05), except for Guy's stone score, which was higher in the multi-tract group (p = 0.028). The multi-tract group also had significantly longer fluoroscopy and operation times (p < 0.001). There was no statistically significant difference in stone-free rates between the two groups (76.0% vs. 78.0%, p = 0.766). Although the drop in hemoglobin levels was more significant in the multi-tract group (p = 0.027), transfusion rates did not differ significantly between the two groups (p = 0.334). Complication rates were higher in the multi-tract group, but this difference was not statistically significant (p = 0.896). This study demonstrated that multi-tract PNL can achieve high stone-free rates with a modest increase in the occurrence of acceptable complications when performed by an experienced surgeon.

Böbrek Taş Lokalizasyonuna Göre Perkütan Nefrolitotomi Operasyonlarının Başarı Ve Komplikasyon Oranlarının Karşılaştırılması

Objective: Percutaneous nephrolithotomy (PNL) is first-line treatment modality for large and complex stones, however it is associated with potential morbidity and severe complications. Therefore, we aimed to evaluate the success and complication rates according to stone localization in large sample group following PNL. Material and Methods: Total number of 782 patients who underwent PNL, were included in this retrospective multicenter study. Patients were divided into two major groups; simple stones group (upper pole, pelvis, lower pole) and complex stones group (partial staghorn, multi-caliceal, pelvis+lower pole, complete staghorn). Surgery time, fluoroscopy time, complications, hospitalization and nephrostomy catheter removal day were recorded. Results: In our study, 525 cases (67.1%) had simple stones, 257 (32.9%) complex stones. The most frequent (34.3%) stone localization was lower pole. Overall blood transfusion rate was 15.1%. Significantly increased in mean number of accesses, surgery time, fluoroscopy time, nephrostomy removal time and hospitalization documented in cases with complex stones (p-values = 0.000, 0.000, 0.009, 0.000 and 0.000, respectively). Overall complication rate was 9.7% (n=76) and the most frequent complication (4.4%) was severe hemorrhage. Overall stone-free rates (SFR) are 74.6% (n=583). Furthermore, complication rate (14.4% vs. 7.4%) was statistically higher and SFR (57.6% vs. 82.9%) was lower in cases with complex stones than simple stones (p-values = 0.002 and 0.000, respectively). Conclusions: Our findings clearly demonstrated that PNL achieved higher success rate and lower complication risk in patients with simple stones than complex stones. PNL is significantly associated with shorter operation duration and hospitalization in simple stones group. Furthermore, PNL provided relatively higher overall SFR and lower complication rates in our large sample group compared to the published data.

Anatomical approach to PCNL: concept of ideal puncture zone in a 3D perspective.

To describe a concept of ideal 'puncture zone' as against any single ideal 'puncture tract' for percutaneous nephro-lithotomy (PCNL) and present our results. Through this narrative, we aim to reduce the gaps in inter-understanding of an erstwhile description of ideal tract and real-life puncture making. The puncture zone principle was applied for our novel puncture making technique during PCNL. The largest imaginary cone that can fit into a respective calyx, with its tip in the pelvis defines the 'puncture zone' for that calyx. This concept allows fine-tuning of the ideal puncture tract based upon the desired corresponding manipulation zone and also shifts the focus of puncture making to infundibulum anatomy from the tip of calyx. The surgical technique and retrospective review of 136 cases done between 2015 and 2021 using this concept are presented. Primary outcome included stone-free rate, pseudo-aneurysm and blood transfusion at 3months of follow-up. 33 cases had multiple (> 3) stones, 21 only calyceal/infundibular stones, eight partial staghorn and 12 were complete staghorn stones. Mean stone size was 29 ± 15 (Range: 5-53) mm. Complete clearance was achieved in 127 cases, four of which required two tracts. Blood transfusion was required in one case. No pseudo-aneurysms were encountered. The puncture zone concept has provided good results in our hands. It may help easier understanding of PCN puncture making and provides a background for reconciliation between description of an ideal tract and practical puncturing techniques used by different surgeons.

Single-Center Experience with Swiss LithoClast® Trilogy for Kidney Stones.

PCNL remains the gold standard for larger kidney stones. Reducing the operating time of PCNL and its complication rate seems to be the next logical step in optimizing this classical technique. To achieve these objectives, some new methods of lithotripsy emerge. We present the data of a single, high-volume, academic center with combined ultrasonic and ballistic lithotripsy in PCNL using the Swiss LithoClast® Trilogy device. We designed a prospective, randomized study including patients who underwent PCNL or miniPerc with lithotripsy using the new EMS Lithoclast Trilogy or EMS Lithoclast Master. The procedure was carried out with all patients in prone position, by the same surgeon. The working channel size was 24 Fr-15.9 Fr. We evaluated the stones' features, operative time, fragmentation time, complications, stone clearance rate and stone-free rate. Our study included 59 patients, 38 females and 31 males, of an average age of 54.5 years old. The Trilogy group included 28 patients and the comparator included 31 patients. Urine culture was positive in seven cases which required seven days of antibiotics. The mean stone diameter was 35.6 mm with a mean Hounsfield unit (HU) of 710.1. The average number of stones was 2.08 (6 complete staghorn stones and 12 partial staghorn stones). A total of 13 patients presented a JJ stent (46.4%). We found a very significant difference in all the parameters favoring the Trilogy device. The most important result in our opinion is the probe active time, which was almost six times shorter in the Trilogy group. The stone clearance rate was about double in the Trilogy group, leading to shorter overall and intra-renal operating times. The overall complication rate was 17.9% in the Trilogy group and 23% in the Lithoclast Master group. The mean hemoglobin drop was 2.1 g/dL with a mean creatinine rise of 0.26 mg/dL. Swiss LithoClast® Trilogy, a device combining ultrasonic and ballistic energy, is a safe and efficient method of lithotripsy for PCNL, proving statistically significant benefits over its predecesor. It can achieve the goal of reducing complication rates and operative times for PCNL.

Retrograde Intrarenal Surgery for Partial Staghorn Calculus in Thoracic Kidney: Case Report

BackgroundThoracic kidney (TK) presenting with symptomatic urolithiasis is a rare case scenario. Retrograde intrarenal surgery (RIRS) for calculus in TK is not reported in the literature. We report a case of partial staghorn calculus in TK managed by RIRS.Case presentationA young adult male presented with back pain and was found to have right TK and bilateral partial staghorn calculus. He also had right cryptorchidism with intraabdominally located testis. He underwent staged bilateral RIRS and laparoscopic right orchiectomy. Follow-up ultrasound imaging showed complete stone clearance in both kidneys.ConclusionsRIRS is safe and effective treatment option, in the management of urolithiasis in TK. The anatomical abnormalities in TK did not play any hindrance role in the ureteral access, renal maneuverability of the flexible ureterorenoscope and subsequent drainage of the stone dust after RIRS.

Percutaneous nephrostomy for complex renal stones: Percutaneous renal access behind the stone versus renal calyx dilation.

To evaluate the technical success rate and complications associated with percutaneous nephrostomy (PCN) via percutaneous renal access behind the stone and renal calyx dilation in patients with complex renal stones. From January 2010 to February 2021, we identified 69 patients with 70 complex renal stones who underwent PCN. Complex renal stones were classified as simple (renal pelvis only) (27.1%, 19/70), borderline staghorn (8.6%, 6/70), partial staghorn (51.4%, 36/70), or complete staghorn (12.9%, 9/70). All PCNs were performed under ultrasound and fluoroscopic guidance using one of two renal-entry techniques: puncture behind the stone (56%, 39/70) or renal calyx dilation (44%, 31/70). Then, we retrospectively evaluated the technical success rates and complications associated with each renal entry access technique. The overall technical success rate was 100%, and the complication rate was 20.0% (14/70). For those who underwent renal access behind the stone, the complication rate was 15.4% (6/39), and six patients (six PCNs) had transient gross hematuria. For those who underwent dilated renal calyx entry, the complication rate was 25.8% (8/31), and one patient had significant bleeding complications requiring transfusion. Furthermore, seven patients (seven PCNs) had transient gross hematuria. Overall, the complication rates did not differ between the technique groups (p = 0.279). PCN for complex renal stones has a high technical success rate and an acceptable complication rate regardless of the specific technique. Renal entry behind the stone is as safe and feasible as approaching via a dilated renal calyx.

Endoscopic combined intrarenal surgery in the prone split-leg position versus Galdakao-modified supine Valdivia position for the management of partial staghorn calculi

Objective:To evaluate and compare the outcome of ECIRS in the treatment of partial staghorn renal calculi in both prone split-leg positions versus GMSV positions with regard to; technical aspects, success rate, operative time, complications, safety, and effectiveness of both approaches.Patients and methods:Between October 2018 and August 2021, 66 patients with partial staghorn calculi were enrolled in this prospective comparative study. Patients were randomly divided according to a 1:1 ratio into two groups. Group A included 33 patients who were treated by (ECIRS) in the prone split-leg position, and group B included 33 patients who were treated by (ECIRS) in the Galdakao-modified supine Valdivia (GMSV) position.Results:No significant statistical difference between both groups regarding the mean age (p = 0.448), mean body mass index (BMI) (p = 0.137), mean stone burden (p = 0.435), mean operative time (p = 0.541) and the number of calyces located in branched stones (p = 0.628). The mean hospital stay was 6.71 ± 1.12 days for group A and 6.66 ± 1.10 days for group B patients (p = 0.724). The final SFR was achieved in (29)87.87% and (30)90.9% of group A & B patients, respectively (p = 0.694). No significant difference was detected between both groups in perioperative complication rates.Conclusion:ECIRS is safe and effective in treating partial staghorn calculi either in the prone split-leg position or in the Galdakao-modified supine Valdivia position, with comparable outcomes and no statistically significant difference between both positions.

Ultrasound Versus Fluoroscopy for Image Guidance During Percutaneous Nephrolithotomy

Introduction: Fluoroscopes are commonly used in PCNL worldwide. While ultrasound is used for screening and localization of renal stones, its role in percutaneous nephrolithotomy (PCNL) is underutilized.&#x0D; Objective: To compare the operative outcome, postoperative outcome and complications of ultrasound versus fluoroscopy guided PCNL.&#x0D; Results: The study was performed from 1st April, 2018 to 30th Sept, 2021. A total of 305 patients were enrolled in the study, with 122 cases performed under ultrasound (UG-PCNL) and 183 under fluoroscopy guidance (FG-PCNL). In the ultrasound group, the mean age was 48.65 ± 12.11 years. 45 were females and 77 were males with a mean stone burden of 754.33 ± 241.22 mm2, with the majority of renal units demonstrating moderate to gross hydronephrosis. While in the fluoroscopy group 81 were females and 102 were males with a mean age 46.28 ± 12.65 years and mean stone size of 763.54 ± 288.97mm2. Partial staghorn stones were found in approximately 25.4% in UG-PCNL while 34.4% in FG-PCNL group. Preoperative parameters including age, sex, stone laterality, stone location, stone size, and severity of hydronephrosis did not differ between each group.There was no significant difference in successful tract creation, stone clearance, operation time , hospital stay, complications and ancillary procedure between UG-PCNL and FG-PCNL. Compared to fluoroscopy, ultrasonography had shorter puncture time, higher success rate of first puncture, shorter tract dilatation time, lesser drop in hemoglobin and lesser blood transfusion requirement.&#x0D; Conclusion: Ultrasound is a safe alternative to fluoroscopy for successful percutaneous renal access and dilatation with similar stone clearance to that of fluoroscopy. The advantages of ultrasonography over fluoroscopy include shorter puncture time, higher success rate of first puncture, lower blood loss, and lower complications. It also avoids radiation exposure and use of contrast media.

Safety and efficacy of prone percutaneous nephrolithotomy (PCNL) in morbidly obese patients.

Objective: To present our experience regarding the safety and efficacy of prone PCNL in morbidly obese patients. Study Design: Observational study. Setting: Armed Forces Institute of Urology, Rawalpindi. Period: February 2018 to February 2020. Material &amp; Methods: After applying inclusion and exclusion criteria, a total of 47 morbidly obese patients undergoing PCNL in prone position were observed prospectively. The demographic data, intraoperative and postoperative outcomes were evaluated. The data were analyzed by SPSS ver. 24. Results: Average age was (46.43±10.41) years with (70.2%) males and (29.8%) females. The mean basal metabolic index (BMI) is (40.47±3.37) kg/m2 and mean stone size was (2.93±0.49 mm). A single stone is seen in twelve patients (25.5%), multiple in sixteen (34.0 %), partial staghorn in nine (19.1 %) and complete staghorn calculus in ten (21.3%) patients. The mean operative time was (83.38±13.20 min), duration of hospital stay (55.94±16.52 hours), stone-free rate (72.3%) and only (27.7%) patients had re-intervention. Calcium oxalate is the most common stone encountered followed by calcium phosphate and uric acid. Intraoperatively, transfusion secondary to bleeding and postoperatively grade 3 clavien-dindo classification is most commonly seen. Conclusion: Prone PCNL is an effective and safe procedure for morbidly obese patients.

An insight into predominance of pulmonary complications on right side in supracostal percutaneous nephrolithotomy.

To analyse pulmonary complications following supracostal percutaneous nephrolithotomy especially after right sided supracostal punctures, both in initial and relook PCNL. From February 2016 till date, 90 patients underwent PCNL in Government Medical College, Jammu through supracostal puncture - 53 on right side and 37 on left side. All supracostal punctures were made about 7-8.5 cm from midline. Tract dilatation was done using metal dilators and calculi were fragmented using pneumatic lithotripsy. Patients with supracostal superior calyceal punctures were evaluated for chest complications intraoperatively by fluoroscopy, X-ray chest on evening of postoperative day 0 and repeated thereafter on third and seventh postoperative days. Stone configuration included complete staghorn in 16, partial staghorn in 23, multiple stones in 16 and pelvic stone in 35 cases. Age range of patients was 07-76 years. There was 14.4% (13 out of 90) incidence of early or delayed chest complications - 20.8% (11 out of 53) on right side and 5.4% (2 out of 37) on left side. Pulmonary complications in supracostal punctures; especially on right side should not be underestimated. There are always chances of delayed hydrothorax after supracostal puncture. A chest X-ray should be repeated after 1 week in patients with supracostal PCNL punctures.

Percutaneous nephrolithotomy in children.

The high success rates of percutaneous nephrolithotomy (PCNL) in the clearance of large renal calculi has made it a primary mode of surgical management in adults. Similarly, in children too PCNL has been gaining ground and the indications for the same are on the rise. We retrospectively evaluated the safety and efficacy of this technique, in children below 18years of age. We retrospectively reviewed the inpatient, outpatient records, imaging films of all children with renal stones undergoing PCNL at our hospital. During the study period, 123 children underwent 129 PCNL at our centre for renal calculi. The mean age was 11.06years and 87 (70.73%) of the children were males. The size of the stones varied from 15 to 37 mms in the longest diameter. A complete staghorn was noted in six (4.65%) and a partial staghorn in nine (6.97%) children. Supine PCNL was performed in 21 (16.2%) children and remaining 102 (83.7%) children underwent PCNL in prone position. The mean drop in haemoglobin was 1.24 gm%. Stone clearance was achieved in 122 (94.5%) children. Post-operatively four (3.1%) children needed blood transfusions due to excessive bleeding. Refinements in percutaneous access techniques, miniaturization of instruments, and technologic advances in energy sources for lithotripsy have led to improvement of outcomes and have lowered the morbidity rates in children following PCNL. It is a safe and effective means of clearing large volumes of renal calculi with minimal morbidity.

Miniaturized percutaneous Nephrolithotomy without antibiotic prophylaxis: a single institution experience.

To assess the feasibility of sparing routine antibiotic prophylaxis in patients without preoperative urinary tract infection (UTI) undergoing a miniaturized percutaneous nephrolithotomy (mPCNL). A retrospective, monocentric study was conducted to evaluate the outcome of a modified perioperative antibiotic management strategy according to the principles of antibiotic stewardship (ABS). From December 2015 patients undergoing mPCNL for kidney stone with preoperative unremarkable urine culture no longer received an antibiotic prophylaxis (NoPAP). The NoPAP group was compared to mPCNL patients who received standard antibiotic prophylaxis (PAP) in the two years before. Analysis focused on postoperative complications. Logistic regression analysis was performed to identify potential risk factors. Postoperative fever occurred in 8% of the NoPAP and 9% of the PAP patients (p = 0.764). Clavien 1-3 complications did not differ between groups with 33% in the NoPAP and 41% in the PAP (p = 0.511). No Clavien 4-5 complications were seen. A (partial) staghorn stone (HR 5.587; p = 0.019) and an infectious stone component (HR 6.313; p = 0.003) were identified as significant risk factors for postoperative fever. By sparing routine antibiotic prophylaxis the overall antibiotic usage was reduced from 100% (PAP) to 9% (NoPAP). Patients with negative preoperative UC, a none-staghorn stone and no history of recurrent UTI or infectious stones may not need routine antibiotic prophylaxis prior to mPCNL. A prospective validation is warranted.

Complications and surgical results of stone-directed antegrade pyelography compared to the retrograde pyelographic access method in percutaneous nephrolithotomy using ‘bull’s eye’ technique: A randomized clinical trial

Objectives: This study aimed to evaluate the differences in outcomes and complications in stone-directed antegrade pyelography using the ‘bull’s eye’ technique in patients with renal stones versus the conventional method of percutaneous nephrolithotomy (PCNL). Although conventional PCNL access using retrograde pyelography is useful, it is time-consuming and may cause postoperative discomfort. Herein, we report our experience in the application of this new technique. Methods: Between January 2017 and June 2018, 100 patients participated in this randomized clinical trial. Stone-directed antegrade pyelography using the ‘bull’s eye’ technique under fluoroscopic guidance was used for percutaneous access in the intervention group. The second group, consisting of those who had undergone conventional PCNL using retrograde pyelography and ‘bull’s eye’ technique in the same period, were considered as the controls. Pre- and postoperative laboratory examinations, surgical results and complications were recorded and compared between the two groups. Results: A single calyceal puncture in partial staghorn and staghorn stone patients was sufficient in 72.2% of the antegrade group and in 78.9% of the retrograde group ( p=0.69). The double-puncture technique was necessary for 71.9% of renal pelvis stones in the antegrade group and for 9.4% in the retrograde group ( p&lt;0.001). The antegrade approach reduced the mean operative time and analgesic requirement significantly ( p&lt;0.001). No statistically significant difference, however, was found between the two groups regarding stone migration to the ureter, radiation time and postoperative complications. Conclusions: The stone-directed antegrade approach using the ‘bull’s eye’ technique is a safe and accurate method in PCNL access in patients with radiopaque and semi-opaque renal stones.

Safety and efficacy of mini-percutaneous nephrolithotomy as daycare procedure: a prospective observational study

BackgroundTo evaluate the safety, feasibility of mini-percutaneous nephrolithotomy (mPCNL) being carried out as a daycare surgery and to study the re-admission, stone clearance rate and complication rates following mPCNL. We also sought to find out the rate of requirement of ancillary procedure, after mPCNL.MethodsIn this prospective observational study, easily accessible patients above 18 years of age with renal and/or upper ureteric calculi, who underwent mPCNL between September 2018 and February 2020, were included. Seventy patients were selected, as per statistical methods. Preoperative evaluation including history, blood and urine investigations and radiological images was collected. Intra-operative and post-operative events were analyzed. Written consent was obtained from the patients to participate in the study and to publish their data. Institutional Ethical and scientific committee clearance was obtained.ResultsOut of 70 patients who underwent mPCNL in the study, in the age group ranging from 24–68 years, most of the cases were partial staghorn with maximum size of stone up to about 3.5 cm. Inferior calyx was most frequently punctured. Six cases had multipuncture mPCNL, four patients had bilateral procedure, and two had supra-costal puncture. Eighteen patients had tubeless mPCNL, of which four were totally tubeless procedures. Four patients had hematuria, none requiring transfusion. Two patients had sepsis, managed with higher antibiotics. Limitation of the study was the sample size. To derive a sturdy conclusion, large scale studies are recommended.ConclusionsWe can conclude that mPCNL can be safely done as daycare or ambulatory surgery in properly selected patients. In centers with experienced urologists, bilateral and multipuncture mPCNL can be done as an ambulatory surgery. Thus, this addresses the stone disease as well as cost containment, without patient safety being compromised. Bed occupancy rate is reduced, helping effective utilization of hospital resources.

Embedded upper end of double J stent at the site of renal pelvis injury following percutaneous nephrolithotomy: a rare complication

BackgroundInjury of the renal collecting system is a well-known complication of percutaneous nephrolithotomy (PNL). Large injuries may cause excessive bleeding and fluid extravasation and require adequate drainage using several modalities such placement of JJ stents. Herein, we report on two cases in which the upper coil of the JJ stent got buried in the fibrous tissues which formed due to an injury of the collecting system during PNL.Case presentation40 years old male and 32 years old female underwent standard PNL for partial and total staghorn calculi, respectively. During the procedure in both cases, the renal pelvis was injured. In both cases, JJ stent was used to drain the collecting system. Trial to remove the JJ stent 6 weeks following the procedure failed because the upper coils of the stents were embedded in the fibrous tissues at the perforation site. Laser incision of the fibrous tissues and releasing the upper coil of the stents were performed using percutaneous approach in the first case and flexible ureterorenoscopy (fURS) in the second patient. The procedures were uneventful in both cases.ConclusionThis is the first report of embedded JJ stents which got buried by fibrous tissues at the site of collecting system injury that occurred during PNL. To prevent this complication in such cases, we suggest draining the collecting system using nephrostomy tube instead of JJ stent. Alternatively, the upper coil of the stent should be placed away from the injury site.

V04-02 ULTRASOUND-GUIDED SUPRACOSTAL PERCUTANEOUS RENAL ACCESS

INTRODUCTION AND OBJECTIVE: Supracostal renal access for endourologic intervention is frequently useful for obtaining access to the upper, mid, and rarely the lower kidney. Upper pole access in particular can afford optimal access to the collecting system and ureter due to renal orientation. However supracostal and upper pole punctures are classically associated with higher rates of pulmonary complications. The ribs can also interfere with imaging and instrumentation. Because of these limitations, there is a tendency towards lower pole punctures in the global urologic community. Ultrasound has become increasingly popular for percutaneous renal access and can potentially address the aforementioned limitations. We illustrate our technique for ultrasound guided supracostal renal access. METHODS: We compiled intraoperative video and ultrasound imaging from a prone percutaneous nephrolithotomy case to illustrate the specific steps and technical considerations for supracostal renal access using ultrasound exclusively. We chose a male patient with a partial staghorn stone who provided consent for filming and use of his patient data. RESULTS: The patient was brought to the operating room and underwent initial survey ultrasound of his right kidney to identify renal and adjacent anatomy, and to choose a puncture site. Through specific maneuvers and positioning of the probe, we were able to identify critical adjacent organs as well as an optimal percutaneous window into a mid renal calyx in the 10th intercostal space. Under ultrasound guidance, we percutaneously accessed this target calyx and dilated a tract using a Seldinger technique to facilitate placement of a 24-French renal access sheath. The patient’s lithotripsy and post-operative course were routine. CONCLUSIONS: A supracostal approach can provide optimal renal access, and its distinct challenges can be overcome with specific ultrasound technique. The ability to visualize anatomy and adjacent structures in real time is invaluable to reducing surgical risk and optimizing clinical outcomes. Appropriate training makes ultrasound guided access readily achievable by urologists, and overtime it can complement fluoroscopy if not replace it as one’s skill set advances. Source of Funding: none

Gas-Containing Renal Stones: A Case Report and Literature Review

We report the 11th case of gas containing renal stone. A 92-year-old Chinese female presented with fever and lower urinary tract symptoms. Urine culture grew Escherichia coli (E. coli). CT abdomen pelvis showed a large gas containing partial staghorn stone. She was managed conservatively with two weeks of antibiotics. Follow up plain kidney, ureter and bladder (KUB) radiograph at 3 months showed that the stone was stable in size. She remained asymptomatic at follow up.

Impact of Anterior Kidney Calyx Involvement of Complex Stones on Outcomes for Patients Undergoing Percutaneous Nephrolithotomy

Introduction: A number of factors that can impact the outcomes of percutaneous nephrolithotomy (PCNL) procedures have previously been investigated. Complex stones that extend to the anterior calyx could affect the success and complication rates of PCNL. Objective: We analyzed the effect of anterior calyx involvement on the outcomes of patients with complex stones treated with PCNL. Methods: A total of 132 consecutive patients who underwent PCNL due to complex stones (multiple, partial staghorn, or staghorn stones) between 2015 and 2017 were enrolled in this study. They were stratified into two groups based on whether the stone extended to the anterior calyx (group 1, n = 45) or not (group 2, n = 87). The stratification was achieved through contrast-enhanced computerized tomography (CT). Demographics, laboratory tests, and peri- and postoperative findings (operation and fluoroscopy duration, hospital stay, utilization of flexible instruments, access numbers, total blood count change, stone-free rate [SFR], and complications) were compared between the groups. The SFR was evaluated by plain kidney-ureter-bladder radiography or CT. Results: The demographics, operation and fluoroscopy duration, access number, and hospital stay were similar between the groups (p < 0.05). A higher drop in the hemoglobin level in group 1 was identified (group 1 [2.14 ± 1.49 g/dL] vs. group 2 [1.43 ± 1.31 g/dL]) (p = 0.006). The SFR among the patients with extension to the anterior calyx was 60%, compared to 77% among the patients with no extension to the anterior calyx (p = 0.041). Flexible instruments were utilized in 60% of the patients of group 1, which was a higher rate than for group 2 (36%) (p = 0.007). Complication rates were similar in the two groups according to the Clavien-Dindo classification (p > 0.05). Conclusions: Our study demonstrated that complicated stones with extension to the anterior calyx are more challenging than cases without extension to the anterior calyx. This was noted by a lower SFR, a more prominent drop in total blood count, and more frequent utilization of flexible scopes.

3:36 PM Abstract No. 112 Hemorrhagic complications of percutaneous nephrolithotomy: factors affecting the complications

To elucidate factors affecting hemorrhagic complications of percutaneous nephrolithotomy (PCNL). Between April 2012 and January 2018, 196 kidneys (right/left: 85/111) in 188 patients (male/female: 83/105, median age: 66) with nephrolithiasis were treated with PCNL. Renal access was obtained mostly through a stone-bearing calyx (79.6%) in the angiography suite prior to PCNL. Medical records and imaging studies were reviewed to record hemorrhagic complications of PCNL, which required abortion of PCNL, blood transfusion, or CT angiography with/without angioembolization. To elucidate the factors affecting the hemorrhagic complications, binary logistic regression analyses were conducted with variables from patients’ demographics (age, sex, body mass index (BMI)), stone characteristics (size, location, CT density, complete or partial staghorn vs. non-staghorn, chemical composition/calcium oxalate-dominance), renal access characteristics (number of calyces punctured, number of renal access for PCNL obtained, accessed calyx (upper, mid, lower), fluoroscopy time/dose) and PCNL characteristics (operator (senior vs. junior), operation time). Of 196 PCNL procedures, 18 (9.2%) were associated with hemorrhagic complications including 5 (2.6%) requiring angioembolization. In univariate analysis, BMI<20 (P = 0.047), complete staghorn (P = 0.047), upper pole stone (P = 0.02), multiple accesses (P <0.01) and renal access fluoroscopy time (P = 0.03) were significant risk factors for hemorrhagic complications of PCNL. Stone composition/calcium oxalate dominance (P = 0.75), PCNL operator (P = 0.15) and operation time (P = 0.25) were not the significant risk factors. In multivariate analysis, BMI<20 (odds ratio (OR) 6.74, confidence interval (CI) 1.50-30.3, P = 0.013), multiple accesses (OR 9.82, CI 2.65-36.4, P = 0.001) and renal access fluoroscopy time (OR 1.04, CI 1.004-1.075, P = 0.028) remained statistically significant. Although hemorrhagic complications of PCNL could be multifactorial, renal access techniques appear to affect the complications. Prolonged manipulation for renal access and PCNL through multiple accesses, especially in patients with BMI<20, may increase the chance of the hemorrhagic complications.

The initial evaluation of the retroperitoneoscopic pyelolithotomy for the partial staghorn renal stone

Purpose: To evaluate initial outcomes of retroperitoneoscopic pyelolithotomy for treating partial staghorn renal stones. Materials and Methods: 9 patients with partial staghorn renal stones were treated by retroperitoneal laparoscopic pyelolithotomy from June 2014 to June 2018. The mean age was 51.2 years (range 31-65); 5 males (55.6%) and 4 females (44.4%). The mean stone size was 5.1 cm (3.2 - 6.8 cm). Results: The retroperitoneoscopic pyelolithotomy procedures for treatment of staghorn renal stones were completely successful in 8/9 cases (88.9%), 1 case (11.1%) required conversion to open surgery by heavy bleed. The estimated blood lost was 20-50ml. The mean duration of the procedure is 95.3 mins (70-165 mins). All of cases (100%) was put the residual stent into the ureter. The mean post-operation hospital stay was 5.2 days (4 - 7 days). About complications: 1 cases (12.5%) of urinary infection; 3 cases (37.5%) of postoperative hematuria. Conclusions: Retroperitoneal laparoscopic pyelolithotomy could be indicated to remove the partial staghorn renal stones up to 6.8 cm in size. Success depends on the experience of surgeons and judicious selection of cases. Key words: Retroperitoneoscopic pyelolithotomy, Staghorn renal stones, Treatment