Understanding ureteroscopy complications according to modified Clavien classification system

Objective: To determine the complications of ureteric stone treatment with semi-rigid uretero-renoscopy in accordance with the modified Clavien classification system. Method: The descriptive, prospective study was conducted at the Department of Urology, Sindh Institute of Urology and Transplantation, Karachi, from June 30, 2020, to December 29, 2021, and comprised patients of either gender aged 18-70 years having ureteric stones. All patients were subjected to ureterorenoscopy using a semi-rigid ureteroscope under general anaesthesia. The patients were followed up for 2 months. All complications were noted and graded in line with the Modified Clavien Complication System. Ultrasound and X-ray were used to determine the stone-free rate. Data was analysed using SPSS 23. Results: Of the 414 patients, 304(73.4%) were males and 110(26.5%) were females. The overall mean age was 40.22±13.10 years. There were 106(25.6%) proximal, 134(32.3%) middle, and 174(42%) distal ureteric stones. Stent placement was done in 56(13.5%) cases. There were 260(62.8%) patients with no complication, 90(21.7%) with grade I complications, 34(8.2%) with grade II complications, 10(2.4%) with grade IIIa, 8(1.9%) with grade IIIb, and 12 (2.9%) with grade IVa complications. Conclusion: Uretero-renoscopy was found to be a safe procedure, as it had minimal associated complications with optimal stone clearance and great dexterity. The Modified Clavien classification system was found to be an easy way to classify surgical complications of uretero-renoscopy.


Introduction
The uretero-renoscopy (URS) procedure is essential to the practice of urology.Hugh Hampton Young used a rigid cystoscope for the first time to carry out this surgery in 1912. 1 Since then, the method has substantially improved and is now the go-to minimally invasive treatment for ureteric ailments.3][4][5] Surgical complications are reported using certain classification schemes.The modified Clavien classification system (MCCS) is the most popular and widely accepted classification system for complications in urological procedures. 6,7greden et al. observed grade I complications in 29.8% of patients, and more severe grade IV complications in just 1.2% patients after URS. 8 In contrast, Mandal et al. found that grade I complications affected 38.3% patients, grade II 15%, grade IIIa 2.5%, grade IIIb 8.3%, and grade IV affected 1.6% patients. 9Ibrahim AK, employing semi-rigid URS, reported grade I complications in 26.1% patients, and just 2.03% grade IV complications. 10 There is a significant stone burden in Pakistan as well as in the South Asian region, and many treatment modalities, including URS, are used for managing ureteric stone. 11The current study was planned to determine URS complications in accordance with MCCS.serum creatinine, electrolytes, ultrasound, X-ray and computed tomography (CT) scan of kidney, ureter and bladder (KUB) of each patient was performed, and postoperatively they were followed for 60 days.
Complications occurring during the follow-up period were noted and graded as per MCCS, 6,7 according to which, grade I=any deviation from the normal postoperative course without the need for pharmacological treatment or surgical, endoscopic and radiological interventions; grade II=requiring treatment with drugs and/or blood products transfusion; grade III = requiring surgical or radiological intervention, with anaesthesia (IIIa) and without anaesthesia (IIIb); grade IV=life-threatening complication leading to single organ failure (Iva) or multi-organ failure (IVb), requiring intensive care unit (ICU) support; and grade V=death.For stone clearance, an ultrasound and X-ray KUB were done, while for radiolucent stones, a CT KUB was performed on the 60th day.Data was analysed using SPSS 23.Mean and standard deviation values were calculated for quantitative variables, while frequencies and percentages were used for categorical variables.
Stratification of confounding variables, like age, gender, location and size of ureteric stones, was done.Poststratification, chi-square test was applied.P<0.05 was taken as significant.

Results
Of the 414 patients, 304(73.4%)were males and 110(26.5%)were females.The overall mean age was 40.22±13.10years.Mean weight of the patients was 65.89±11.33kg.Mean height was 162.1610.00cm.Mean operative time was 19.68±7.20 minutes, and the hospital stay was 1.18±0.82 Understanding ureteroscopy complications according to modified Clavien classification system  Age, gender, location and size of the stone had no significant association with MCCS grades (Table 2).

Discussion
The assessment of surgical outcome has always been crucial to the practice of surgery.It effectively aids in enhancing healthcare quality management, aids in analysing the learning curve for certain manoeuvres and/or procedures, and ultimately supports surgical research.A crucial factor in the assessment of any medical intervention is the morbidity rate. 12porting surgical outcomes and unfavourable events is rife with overlap and lack of specificity.The term "postoperative complications" is described as unwanted and unintentional problems occurring following a surgery. 13though evidence-based medicine has come a long way, both clinical studies and hospital records have shown inconsistent reporting of perioperative adverse events.Between 1990 and 2001, only one-third of large randomised controlled trials (RCTs) in surgery with more than 100 patients used severity grading.[15][16] Urolithiasis is a very common pathology in South Asia, and a lot of patients suffer from renal and ureteral stone diseases.Numerous medicinal and surgical techniques are available to treat ureteric stones.Medical expulsion therapy was found to be effective in helping spontaneous passage of stone <10mm in size. 17On the contrary, URS and lithotripsy are considered the main options for treating ureteric calculi. 18Due to advancements in medical technology and the miniaturisation of instruments, endoscopic management of ureteral stone disease has gained popularity. Globally, URS is recognised as a standard therapeutic modality for ureteral stones that is simple and effective.Procedures' success is influenced by size and site of the stone.URS is more effective than shock wave lithotripsy (SWL) for stones >1cm in size.With success rates between 81% and 94%, URS is deemed safe.However, it can cause morbidity and, in rare cases, fatal consequences. 19,20ere have been numerous ureteroscopic complications documented in literature, but they are frequently classified as mild and significant or short-term and long-term.These categories are arbitrary, and most urologists do not agree on them.Additionally, the majority were retrospective and, therefore, lack a consistent, organised system. 20,21A research study that used the modified Satava classification, a distinct structured grading system, revealed URS complications. 20,21ere are certain classification systems available to report surgical complications.The most commonly used and validated grading system for complications in urological procedures is the MCCS.The overall reported complication rate ranges from 3.5% to 30%. 21,22e current study assessed URS outcomes using the MCCS. 6,7 Another study using semi-rigid URS found grade 1 complications in 26.1% patients, grade II 6.1%, grade IIIa 4.7%, grade IIIb 5.4%, and grade IV in 2.03% patients. 10ophylactic antibiotics were given to all patients in the current study.In only 8 patients, stones were not found, which is due to stones passing through the urethra that the patients may not notice.Stone clearance was seen in the majority of patients.Clinically insignificant residual fragment (CIRF) were seen in a few patients who were being kept on follow-up and observation, and on alphablockers.Age, gender, stone site and size had no significant effect over outcomes and complication rate in the current study.
According to the MCCS, grades 1 and II are considered minor complications, while grades iii-V are considered major complications. 6,7This system made it simple, quick and easy to classify complications.
One of the limitations of the current study is that its data related to a single centre.While the MCCS proved to be accurate, useful, and simple to use, the study should have incorporated other crucial factors, like management expense and readmission rate.

Conclusion
URS was found to be a safe procedure and was associated with minimal complications, with the majority of patients having grade I and II complications As per the MCCS which was found to be a straightforward and efficient tool for evaluating surgical complications.

Table - 2
: Age, gender, stone size and stone location with modified Clavien classification system (MCCS) complication grade.

value Grade I Grade II Grade IIIa Grade IIIb Grade IVa Grade IVb Grade V
Figure: Distribution of categorical data.No. of Patients ASA: American Society of Anaesthesiologists, MCCS: Modified Clavien classification system Stone Clearance days (