HUE UNIVERSITY UNIVERSITY OF MEDICINE AND PHARMACY HOANG DUC MINH STUDY THE OUTCOMES OF SEMI RIGID URETEROSCOPY IN THE TREATMENT OF RENAL STONES Specialism Surgery Major code 9 72 01 04 SUMMARY OF MED[.]
HUE UNIVERSITY UNIVERSITY OF MEDICINE AND PHARMACY HOANG DUC MINH STUDY THE OUTCOMES OF SEMI-RIGID URETEROSCOPY IN THE TREATMENT OF RENAL STONES Specialism: Surgery Major code: 9.72.01.04 SUMMARY OF MEDICAL DOCTORAL THESIS HUE - 2023 Thesis was completed at: UNIVERSITY OF MEDICINE AND PHARMACY, HUE UNIVERSITY Doctoral advisors: Assoc Prof NGUYEN KHOA HUNG, MD, PhD The thesis could be found in: National Library of Vietnam Library University of Medicine and Pharmacy, Hue University ABBREVIATIONS ASA CT scan ESWL Fr KUB P PCNL RIRS SFR S-URS UIV UPJ URS American Society of Anesthesiologists Computed tomography scan Extracorporeal shock wave lithotripsy French scale (1 Fr = 1/3 mm) Kidney–Ureter–Bladder Probability value Percutaneous Nephrolithotomy Retrograde Intrarenal Surgery Stone-free rate Semi-Rigid Ureteroscopy Urographie Intraveineuse Ureteropelvic junction Ureteroscopy INTRODUCTION In general, the worldwide prevalence of urolithiasis ranges from 215% of the population, in which renal stones are the most common, representing about 40-50% of cases In the past, without lithotripsy, open surgery was the first choice in the treatment of kidney stones The advent of extracorporeal shockwave lithotripsy in the 80s of the 20th century has opened a new era for the treatment of renal stones Subsequently, with the advent of other less invasive intervention methods such as percutaneous nephrolithotomy and retrograde intrarenal surgery, the rate of open surgery in the treatment of kidney stones has decreased notieceably, even to less than 5% in certain areas Retrograde intrarenal surgery accesses the stones via a natural route, thus avoiding damage to the renal parenchyma and reducing the risk of bleeding While flexible ureteroscope possesses the ability to access the entire pelvicalyceal system, semi-rigid ureteroscopy is superior regarding the endoscopic field of view, larger irrigation and working channel, allowing larger laser wire and instruments to help fragment the stones quickly, at the same time, at a lower cost with high durability For the stones of the renal pelvis and/ or upper calyces, which are accessible without requiring the use of flexible ureteroscope, retrograde nephroscopy using a semi-rigid ureteroscope delivers highly satisfactory results In 1983, Huffman JL et al reported the first cases of using a semirigid ureteroscope for the treatment of renal pelvic stones without early or late complications and long-term renal dysfunction Since then, there have been many studies using semi-rigid ureteroscope to treat kidney stones in the world and in Vietnam, which all proved that this technique to be a safe, highly effective method, with low complication rate, short hospital stay, reduced postoperative pain, quick recovery, and unaffected longterm kidney function Currently, several urology centers across the country have applied semi-rigid ureteroscopy in the treatment of kidney stones including Hanoi, Da Nang, Quang Binh, Quang Tri, etc Hue University of Medicine and Pharmacy Hospital has implemented this technique since 2013, achieving initial positive results with a high success rate of over 70% and a low rate of intraoperative and postoperative complications In order to evaluate the safety and effectiveness of this technique in the treatment of kidney stones, as well as to provide additional data and basis for clinicians to select the optimal treatment, we conducted the thesis: “Study the outcomes of semi-rigid ureteroscopy in the treatment of renal stones” with two objectives: 1/ To study the clinical and paraclinical characteristics of patients with renal pelvis and/ or upper calyx stones treated by semi-rigid ureteroscopy at Hue University of Medicine and Pharmacy Hospital from 2016 to 2020 To evaluate the outcomes of the treatment of kidney stones by semi-rigid ureteroscopy and influencing factors in the above patient group CONTRIBUTIONS The new contributions of the thesis The thesis has contributed to domestic research data on the applicability of semi-rigid endoscope in the treatment of renal stones The success of this study will further confirm the advantages of the treatment method for renal stones This is a minimally invasive technique, accessing the stones via a natural route, thus avoiding damage to the renal parenchyma and reducing the risk of bleeding Today, with the significant technological improvement in the design of semi-rigid ureteroscope and the development of Holmium laser technology and ancillary instruments, retrograde intrarenal surgery with the use of semi-rigid ureteroscope is increasingly widely applied in the treatment of kidney stones Treating kidney stones with semi-rigid ureteroscopy is a safe and feasible choice with a high stone-free rate (70-95%), shortened operative time, and reduced treatment costs as well as fewer intraoperative and postoperative complications, shorter length of hospital stay, reduced postoperative pain, quick recovery, no longterm kidney dysfunction and good patient’s satisfaction A number of factors affecting the treatment results including technical details, stone position were investigated to improve success and stone-free rates, as well as reduce the risk of intraoperative and postoperative complications The layout of the thesis The thesis consists of 135 pages with introduction: pages, overview: 35 pages, research objects and methods: 27 pages, results: 23 pages, discussion: 45 pages, conclusion: pages, recommendation: page In the thesis, there are 57 tables, charts, diagram and 33 figures There are 125 references, including 21 in Vietnamese and 104 in English CHAPTER LITERATURE OVERVIEW 1.1 Endoscopic anatomy of the upper urinary tract 1.1.1 Cystoscopy and upper urinary tract access When evaluating the bladder endoscopically the ureteral orifices are approximately cm apart when the bladder is full and about 2.5 cm when the bladder is empty The ureteral orifices together with the neck of the bladder form a triangle called the trigone The raised ridge connecting the two ureteral orifices is the interureteral ridge Traumatic instrumentation or incision of the ureteral orifice can result in permanent reflux Atraumatical dilation of the ureteral orifice with a catheter or balloon can avoid this complication However, dilation of the ureteral orifice alone may in some cases not be sufficient for passage of the ureteroscope up the upper urinary tract due to the narrowing of the ureteral lumen There are many techniques to dilate ureteral orifice: (1) Prior JJ stent placement to dilate the ureteral orifice and the ureter; (2) Active dilation with use of a ureteric access sheath; (3) Balloon dilator 1.1.2 Size of the lumen of the ureter The average adult length of the ureter is 25 - 30 cm (6.5 - 7.0 cm in neonates) and its diameter is 1.5 - 6mm The specific description of each ureter segment viewed on retrograde endoscope from the bladder is as follows: - The intramural ureter: this is the first physiological narrowing, which is 1.2 - 2.5cm in length in adults and 0.5 - 0.8cm in neonates At this level, the ureteral lumen is minimal (1.5 - 3mm), requiring its dilation when ureteroscopes with a larger caliber are used - The second physiological narrowing is the point where the ureter crosses over the iliac artery It has a diameter of 4mm and witnesses a change in the curve of the ureter Where the ureteral caliber is of approximately mm, is situated in the area where it crosses the iliac vessels The pulsations of iliac artery being observed posterointernally through the ureteral wall as a significant anatomic landmark of this ureter segment - The next segment is the abdominal ureter, with the largest size, which can reach 10mm in its most dilated condition, making it favourable for the scope to be passed through This segment is relatively straight and located anterior to the psoas muscle - The third physiological narrowing is the ureteropelvic junction with a fairly narrow lumen (2 - 4mm) and a change in its course 1.1.3 Ureteropelvic Junction The ureteropelvic junction (UPJ) can be easily identified during retrograde nephroureteroscopy because of its frequent opening and closing The UPJ then empties into the wider renal pelvis superiorly The respiratory movement of the kidney could be seen by endoscopy after passing the relatively fixed UPJ During retrograde endoscopy, it is necessary to wait for the ureter to dilate before passing the ureteroscope up to avoid trauma to the mucosal ureter 1.2 Types of ureteroscopes 1.2.1 Rigid ureteroscopes Rigid ureteroscope is suitable for distal ureter due to its usability and good control of maneuvers Most rigid ureteroscopes has its size increasing from the tip to the body of the scope Therefore, when performing ureteroscopy, it may not be possible to pass the scope up because the body of the scope is stuck at the ureterovesical junction The large diameter of the scope has certain advantages such as: larger working channel, better irrigation and better visibility However, because its diameter is greater than 10 Fr, accessing the ureter requires dilatation of the ureteral orfice, moreover, the large size of the scope is also more likely to cause trauma to the ureter 1.2.2 Semirigid ureteroscopes Today, rigid ureteroscopes have been mostly replaced by semirigid ones The size of the scope varies from - 10 Fr at its tip, while that of its body ranges from 7.8 to 14.5 Fr These types of scopes can be bent along its vertical axis without either damaging the optic or the scope body or affecting the quality of the endoscopic images, therefor, they are called semi-rigid ureteroscopes The working channel of the semi-rigid ureteroscope ranges from 2.1 to 6.6 Fr in size Nowadays, the ureteroscope with two working channels is increasingly widely used The larger working channel has a diameter of 3.4Fr, while that of the smaller one is 2.1 – 2.4Fr This design allows an empty channel for continuous irrigation when manipulating instruments during endoscopy Notably, when performing lithotripsy with small laser wire, this wire can be passed through the small working channel, while the larger channel is used for irrigation This will help improve irrigation capacity, reduce pressure in the pelvicalyceal system and clearer optical field 1.2.3 Flexible ureteroscopes From the first report by Marshall VF about the flexible ureteroscope in 1964, up to now, the flexible ureteroscope has undergone significant improvement in terms of design and application Although the flexible ureteroscope is small in size, the magnification of the ureteroscope can be up to 3-50 times Normally, flexible ureteroscopes have an active flexion of 1800-2750, which is sufficient to access the subrenal calyx because the angle between the ureter and the inferior calyx is about 1400 Currently, there are two types of digital flexible ureteroscopes: reusable and disposable one 1.3 Laser lithotripsy technique during retrograde intrarenal surgery A: “Dusting” or “Dancing” technique, which is best applied to soft stones B: “Chipping” technique, when the periphery of the stone is chipped off into small fragments This is the optimal option for harder stones C: “Popcorning” technique, best used for small stone segments which are – 4mm in size and located in a non-dilated calyx D: “Fragmenting” technique, when the stones are divided into big fragments, considered as the best option for very hard, large and small in quantity stones 1.4 Some intraoperative and postoperative complications 1.4.1 Intraoperative complications - Renal pelvis mucosal abrasion - Hemorrhage during surgery - Burns of the renal pelvis mucosal - Perforation of renal pelvis - Renal pelvis avulsion 1.4.2 Early postoperative complications - Urinary extravasation - Postoperative hemorrhage - Postoperative fever - Urinary tract infection 1.4.3 Late postoperative complications - Ureteral stricture - Urethral stricture CHAPTER RESEARCH SUBJECTS AND METHOD 2.1 Research subjects 2.1.1 Patient selection criteria - Age: ≥ 16 years old - Stone location: renal pelvis and/ or upper calyx - Stone size: 7-30 mm - Grade of hydronephrosis: non-hydronephrotic or ≤ grade - Pre-anesthesia assessment with an ASA of ≤ - Regardless of gender and patients have agreed to take part in the study 2.1.2 Exclusion criteria - Untreated urinary tract obstruction - Ipsilateral non-functioning kidney - Pregnant women - Hip joint disease preventing leg abduction - Uncured urinary tract infection 2.1.3 Time and place: Our study was performed from 01/2016 to 06/2020 at the Department of Neuro-urologic surgery, Hue Univerisity of Medicine and Pharmacy hospital 11 3.1.3 Diagnostic Imaging - Urinary tract ultrasound: Grade hydronephrosis took up 52.2%, 10 cases (14.5%) were non-hydronephrotic, Grade hydronephrosis occupied 33.3% - Urogram with contrast: + Urography with contrast was carried out on 65/69 patients (94.2%), including: 68.1% cases with CT urography and 26.1% with intravenous urography + There were patients (5.8%) on whom JJ stent had been placed month before, thus, only ultrasound and KUB X-ray could be performed in these cases 3.1.4 Kidney stones features - Side of intervention: Right kidney stones took up 55.1% - Location of stones: Simple renal pelvic stones were found in 84.1% cases, simple upper calyx stones made up 5.8%, concurrent renal pelvic stones accounted for 10.1% - Number of stones: In total, there were 84 stones in 69 cases, with an average of 1.2 ± 0.5 stones per case, a minimum of stone and a maximum of stones Cases with stone constituted 81.2% - Size of stones: + The average size of the stones was 20.2 ± 5.5 mm, the smallest was 9mm and the biggest was 30mm + Stones which were ≤ 20 mm made up 55.1% cases, including case (1.4%) in which the size of the stone was < 10mm - Radiopacity of stones: stones with radiopacity equivalent to that of ipsilateral 12th rib constitubed 75.4%, lower than that of ipsilateral 12th rib made up 15.9%, the remaining cases (8.7%) had a higher radiopacity 3.2 Evaluation of surgical outcomes 3.2.1 Intraoperative characteristics 3.2.1.1 Anesthesia method Table 3.14 Relationship between gender and anesthesia method Anesthesia method Gender Total p Endotracheal Spinal Male 28 (70.0%) 12 (30.0%) 40 (100%) 0.490 Female 18 (62.1%) 11 (37.9%) 29 (100%) 12 - Endotracheal anesthesia accounted for 66.7%, this method was more prevalent among males than females (70.0% versus 62.1%, respectively), this difference was not statistically significant (p 60 12.5 Total 64 100 48.7 ± 13.1 (25 - 85) Average Operative time 13 3.2.1.8 Volume of fluid used intraoperatively Table 3.19 Volume of fluid used intraoperatively Volume of fluid (Litter) Number (n) Proportion (%) ≤2 57 89.1 >2 10.9 Tổng 64 100 Average volume 1.6 ± 0,6 (1.0 – 4.0) Table 3.20 Relationship between operative time and fluid volume Fluid volume Average n (%) p Operative time (litter) ≤ 60 mins 56 (87.5%) 1.6 ± 0.6 0.006 > 60 mins (12.5%) 2.2 ± 0.3 3.2.1.9 Intraoperatively stone-free (immediate stone-free): immediate stone-free rate was 65.6%, 34.4% cases had residual stones 3.2.2 Postoperative follow-up 3.2.2.1 Early complications after surgery There were cases with early complications after surgery (14.1%), in particular: Table 3.22 Early complication grading according to modified Clavien classification Grade Early complication Number (n) Proportion (%) Grade No complication 55 85.9 Postoperative hematuria 6.3 Grade I Postoperative fever 4.7 Grade II Urinary tract infection 3.1 Tổng cộng 64 100 Table 3.23 Factors influencing early complications after surger Early Complication No Yes p Factor Average operative time (mins) 48.0 ± 12.8 52.6 ± 14.6 0.338 Average fluid volume (litter) 1.6 ± 0.6 1.9 ± 0.8 0.116 3.2.2.2 Postoperative hospital stay - The average postoperative hospital stay was 4.1 ± 1.7 days (1 – days); to days group took up 62.5% - The average postoperative hospital stay of group with early complications (6.6 ± 0.9 days) was longer than that of group without early complications (3.7 ± 1.4 days) and this difference was statiscally different (p 20 mm p Factor 38 (100%) 26 (83.9%) Intraoperative Fragmentation 0.010 outcome Failure (0%) (16.1%) No 35 (92.1%) 20 (76.9%) Early 0.086 complications Yes (7.9%) (23.1%) Yes 34 (89.5%) 12 (46.2%) 0.001 month No (10.5%) 14 (53.8%) Stone-free after surgery Yes 36 (94.7%) 15 (57.7%) 0.001 months No (5.3%) 11 (42.3%) Average operative time (mins) 43.5 ± 10.2 56.3 ± 13.3 0.001 Average fluid volume (litter) 1.5 ± 0.7 1.8 ± 0.4 0.030 Average postoperative time (days) 4.0 ± 1.7 4.2 ± 1.8 0.597 3.3.4 Location of stones Table 3.32 Relationship between location of stones and treatment outcomes Location of stones Factor Intraoperative Fragmentation outcome Failure No Early complications Yes Renal Pelvis 54 (93.1%) (6.9%) 45 (84.9%) (15.1%) Upper Calyx (75.0%) (25.0%) (100%) (0%) Pelvis + Upper (100%) (0%) (87.5%) (12.5%) p 0.296 0.758 16 Yes 42 (79.2%) (33.3%) (37.5%) 0.016 month No 11(20.8%) (66.7%) (62.5%) Yes 47 (88.7%) (33.3%) (37.5%) 0.001 months No (11.3%) (66.7%) (62.5%) Average operative time (mins) 47.9 ± 12.5 46.7 ± 16.1 54.8 ± 15.7 0.372 Average fluid volume (litter) 1.6 ± 0.6 1.5 ± 0.5 1.9 ± 0.4 0.508 Average postoperative time (days) 4.1 ± 1.8 4.3 ± 1.5 3.8 ± 1.3 0.817 3.3.5 Number of stones Table 3.33 Relationship between number of stones and treatment outcomes Number of stones stone ≥ stones p Factor 51 (91.1%) 13 (100%) Intraoperative Fragmentation 0.263 outcome Failure (8.9%) (0%) No 44 (86.3%) 11 (84.6%) Early 0.878 complications Yes (13.7%) (15.4%) Yes 42 (82.4%) (30.8%) 0.001 month No (17.6%) (69.2%) Stone-free after surgery Yes 46 (90.2%) (38.5%) 0.001 months No (9.8%) (61.5%) Average operative time (mins) 47.2 ± 12.8 54.4 ± 13.1 0.077 Average fluid volume (litter) 1.6 ± 0.6 1.9 ± 0.4 0.118 Average postoperative time (days) 4.1 ± 1.7 3.9 ± 1.6 0.688 3.3.6 Degree of hydronephrosis on ultrasound Table 3.34 Relationship between degree of hydronephrosis on ultrasound and treatment outcomes Degree of hydronephrosis NonGrade Grade p Factor Intraoperative Fragmentation (90.0%) 33 (91.7%) 22 (95.7%) 0.793 outcome Failure (10.0%) (8.3%) (4.3%) No (88.9%) 29 (87.9%) 18 (81.8%) Early 0.788 complications Yes (11.1%) (12.1%) (18.2%) Yes (55.6%) 25 (75.8%) 16 (72.7%) month 0.487 No (44.4%) (24.2%) (27.3%) Stone-free after surgery Yes (66.7%) 27 (81.8%) 18 (81.8%) 0.578 months No (33.3%) (18.2%) (18.2%) Average operative time (mins) 50.0 ± 7.4 48.4 ± 15.0 48.5 ± 12.2 0.948 Stone-free after surgery