Abstract
Introduction and objectives:
Admissions for ureteric colic are relatively common, with up to 80% of stones passing spontaneously. In patients with refractory pain, drainage with stenting, percutaneous nephrostomy or stone removal can be performed. Due to the financial restrictions of the NHS, it is paramount to ensure patients are receiving optimal cost-effective care. We present a cost effectiveness analysis between primary ureteric stenting and emergency ureteroscopic stone removal in patients with refractory pain secondary to acute ureteric calculi.
Methods:
Fifty patients were analysed who underwent either primary ureteric stenting or emergency ureteroscopic stone removal in our institution. Each group contained 25 consecutive patients. The primary outcomes compared were: time to stone-free status, number of hospital re-admissions, and overall cost of treatment until stone free.
Results:
Both stenting (n=25) and ureteroscopic stone removal (n=25) groups were comparable with respect to age, sex, stone size and location. The hospital re-admission rate secondary to stone-specific issues was significantly lower in the ureteroscopy group, two versus 20. Patients became stone free significantly quicker in the ureteroscopy group (2.5 days vs. 61.9 days). The total overall cost until being declared stone free was significantly lower in the ureteroscopy group (£3104 vs. £4041, P⩽0.001).
Conclusions:
This study highlights that those patients undergoing ureteric stenting take significantly longer to become stone free, leading to increased hospital re-admissions, potentially increased morbidity and inevitably greater cost implications. We advocate that primary ureteroscopic stone removal should be consider instead of ureteric stenting in patients with ongoing, painful ureteric colic.
Introduction
Urinary tract stone disease is common, with prevalence rates in different countries varying from 1% to 20%. 1 It is on the rise and recent epidemiological studies have shown that the prevalence has doubled in the last 15 years. 2 The lifetime risk is about 12% in men and 6% in wome. 3 It is estimated that roughly 1.2 million people have an episode of acute renal colic each year, which accounts for roughly 1% of all acute hospital admissions. 4 The most common cause of renal colic is ureteral obstruction secondary to calculus (>95%).
Up to 80% of stones will pass spontaneously without surgical intervention. 5 The rate of spontaneous passage of stone is dependent on multiple factors including stone size and location. Acute surgical intervention is required in the following situations: an obstructed and infected kidney, obstructed solitary kidney, bilateral obstruction and uncontrollable pain. Acute decompression is achieved by either percutaneous nephrostomy, or retrograde ureteral stenting, depending on local availability. A recent prospective study has shown that there are no significant differences in outcomes between these two interventions. 6
The 2015 European Association of Urology (EAU) guidelines state that definitive stone treatment should be deferred until the sepsis subsides.
A meta-analysis by Picozzi et al. identified emergency ureteroscopy (URS) for obstructing (in the absence of infection) ureteral calculus seems to be a safe treatment with a high success rate. 7 This is acknowledged by the EAU guidelines, which state if intervention is indicated (in the absence of infection), URS and stone removal is a reasonable option to avoid long-term stenting/drainage.
Urinary stone disease has a significant economic burden worldwide particularly because 50% of patients will have recurrent renal colic within 5 years. 8 Over US$2.1 billion was spent on the treatment of urinary stones in 2000 in the United States. 9 With the current economic challenges of the National Health Service (NHS), it is paramount that patients receive optimal cost-effective treatment.
Our study compares the differences in cost, morbidity and time taken until declared stone free from a single ureteral stone episode for patients with uncontrollable pain, who underwent either acute primary ureteral stenting or acute primary URS stone removal.
Methods
Retrospective analysis was conducted of patients who required emergency admission into our institution with computer tomography (CT) confirmed ureteric calculi. All patients had uncontrollable pain requiring either primary ureteral stenting or URS and stone removal between January 2013 and January 2015. Exclusion criteria included: sepsis, renal dysfunction, solitary kidney or anatomical abnormalities. Overall, 50 patients were selected. Each group contained 25 consecutive patients. Data were collected from the patients’ medical notes, operation notes and local radiological imaging and pathology viewing systems.
All patients had primary intervention as an emergency during their initial admission. The intervention performed (primary ureteric stenting or primary URS) was determined by the operating surgeon and patient’s preference. All procedures were performed under a general anaesthetic.
Ureteral stenting was achieved by retrograde insertion by rigid cystoscopy. Stent size and length was determined by individual patient characteristics. All stents were positioned under fluoroscopic guidance.
Stone removal surgery was performed with semi-rigid URS. The stone/s were either extracted by endoscopic basket alone, or fragmented followed by basket extraction. Fragmentation was performed by either (Ho:YAG) laser lithotripsy or Swiss lithoclast depending on operator preference.
Ureteral stents were removed either by flexible cystoscopy under local anaesthetic (non-tethered stents) or in clinic/ward with tethered stents.
The treatment start point was considered from the time of primary surgical intervention. The treatment end point was recorded as the time when the patient was declared stone free.
The primary outcomes compared were: time to stone-free status, number of hospital readmissions, operative costs and overall total cost of secondary care treatment until stone free.
Only the ureteral stone/s causing obstruction were considered. Other concomitant non-obstructive urinary tract calculi were not analysed in this study. Criteria for being deemed stone free were: ureteral stone not visible in follow-up X-ray of the kidneys, ureter and bladder/CT, or stone removal documented in the operation notes with no stone visible in follow-up imaging.
Costing data were calculated from the clinical coding and specialty-costing departments in our institution. Consideration was taken of the significantly higher costing tariffs of emergency operations, as compared to elective surgery. These figures are an average estimated cost for instruments, maintenance/repair and service, cost of operating room use and staff required, and overhead cost for administration. These costs only take into account the ‘operative costs’.
The ‘total cost of secondary care treatment’ was calculated using the operative costs in combination with the average costs of hospital admissions (including emergency department and inpatient hospital bed day costs).
Statistical analysis was conducted using Microsoft Excel 2015 and Statistical Package for the Social Sciences (SPSS) version 22. The chi-squared test was used for comparing categorical data, whereas continuous data were compared using Student’s t-test and the Mann–Whitney U-test.
Results
Patient demographics
Both primary ureteric stenting (n=25) and primary ureteroscopic stone removal (n=25) groups were comparable with respect to age, sex, stone size and location. The stenting group had a slightly older patient cohort and had more upper ureteric stones; however, these variables were not statistically significant. Table 1 displays the comparability of the patient demographics of both groups.
Patient demographics and clinical characteristics between groups.
URS: ureteroscopy.
Surgical outcomes
The treatment success rate for primary ureteroscopic stone removal was 92%. This was defined as complete extraction of stone. In the two patients who failed treatment, both of which had upper ureteric calculi, the stone was dislodged into the lower pole calyx. Both these patients had successful secondary flexible ureteroscopic stone removal.
The treatment success rate of elective ureteroscopic stone removal in patients who had primary ureteric stenting was 96%. One patient had a symptomatic residual stone fragment, which was cleared by a subsequent procedure.
Overall, stone clearance was 100% in both groups with, at most, two ureteroscopic procedures.
Eight out of the 25 patients who underwent primary URS had ureteric stent placement at the end of the procedure. Six were tethered and were removed within 2 weeks in the outpatient clinic. Two were not tethered because of failed stone clearance and were left in situ until the repeat ureteroscopic procedure. Six out of the 25 patients who had elective URS, preceded by primary ureteral stenting, required another ureteral stent at the end of the procedure. Five of these stents were tethered.
Surgical complications for both groups were minimal. In the ureteric stenting group, two patients had post-procedure urinary tract infection, and one patient had temporary urinary retention. In the ureteroscopic group, one patient had post-procedure urinary tract infection, one patient had persistent frank haematuria and one patient had post-procedure urinary retention.
Post-procedural length of hospital stay was comparable between both groups (Table 2). However, the mean overall length of inpatient bed days (including readmissions) until stone free was significantly longer in the ureteral stenting group (3.2 days vs. 1.4 days).
Comparison of primary and secondary outcomes between groups.
URS: ureteroscopy.
Readmission to hospital, secondary to ureteral stone-related morbidity, was significantly higher in the ureteral stenting group (20 vs. two). The majority of readmissions were related to acute pain episodes secondary to the stent. The other readmissions were related to the post-procedural complications mentioned above.
There was a significant difference between the two groups when comparing the length of time until declared stone free. The ureteral stenting group took much longer in becoming stone free. This was mirrored by the length of time until stone and stent free (Table 2).
Cost outcomes
The average operating cost for an emergency ureteroscopic stone extraction was £2568.31 at our institution. The same procedure performed electively cost £1973.55. The average operating cost for an emergency retrograde ureteral stent insertion was £1117.11. Removal of a ureteral stent with flexible cystoscopy cost £135.50.
Using these estimations, the average operative cost per person until the patient was declared stone free with all indwelling ureteral stents removed was significantly lower for the URS group (£2742 vs. £3259).
The total cost of secondary care management (operative cost plus inpatient hospital bed cost plus emergency department admission costs) in the URS group was significantly lower than the primary stenting group (Figure 1).
Cost implications between both groups until stone free.
The stone location was divided into upper (above pelvic brim) and lower (below pelvic brim) ureter.
We found the total cost of secondary care management for patients with lower ureteric stones was significantly lower in the URS group (£3084 vs. £4183). Although it appeared the same trend applied for upper ureteric stones, the cost difference between the groups was not statistically significant (Figure 2).
Mean total cost until stone free by stone location.
Discussion
From the literature, stone-free rates for distal and proximal ureteric stones following URS are 93% and 82%, respectively. 10 Although our study had a limited sample size, overall stone-free rates were comparable with distal stone clearance of 100%, and 87.5% (80% in emergency URS, 92.9% in elective URS) for proximal ureteric stones. One further limitation was that we divided ureteric stone location into upper and lower (due to limited sample size), whereas the published data divide it into mid-ureter as well, making comparability analysis difficult.
We encountered no intraoperative complications. Early complications were urinary tract infection (6%), persistent haematuria (2%) and urinary retention (4%). All postoperative complications were a Clavien–Dindo grading system score of II or less. These figures are comparable to the large series of complication rates in 2735 ureteroscopic procedures of Geavlete et al. 11 Late complications were not evaluated in our study.
Indwelling ureteral stents have a significant impact on health-related quality of life. Joshi and colleagues constructed a psychometrically validated questionnaire to evaluate the symptoms and impact on quality of life of ureteral stents. They showed that in over 80% of cases, the stent caused a degree of pain that affected the functioning of daily activities, with 58% reporting reduced work capacity and negative economic impact.12,13 Ureteral stenting also caused 78% of patients to experience lower urinary tract symptoms and persistent haematuria. The overwhelming cause of morbidity and readmissions to hospital in this current study was caused by ureteral stent-related symptoms. This resulted in longer inpatient hospital stays for patients in the ureteral stenting group, which inevitably led to greater costs to the health service.
Our study has shown a significant delay in being declared stone free when primary ureteric stenting was performed (61.88 days vs. 2.48 days). A difference is expected, as the two groups are incomparable for this variable, because one treatment group is not receiving stone removal surgery and will require a secondary procedure. Despite this, the ureteral stenting group still had a 2-month delay in stone removal treatment. In the majority of cases this was secondary to theatre availability and waiting list pressures, which is a universal issue. This potentiates the morbidity and quality of life issues as described above leading to poorer patient outcomes.
The NHS net expenditure is increasing annually; with an estimated spend of £113.300 billion, and a net deficit of £671 million in 2014/201. 14 Therefore cost analysis data have a major role in the current and future health economic climate. A cost analysis study comparing the different treatment modalities for ureteral calculi (URS, shock wave lithotripsy and observation) found URS is the most cost-effective treatment strategy in all ureteric locations after observation fails. 15 To the best of our knowledge, we present the first direct cost analysis comparing primary ureteric stenting and primary ureteroscopic stone removal for ureteral calculi.
Operative costs are only a part of the overall cost of treatment in these patients. Hospital admission and inpatient stay costs, medical prescriptions, imaging and laboratory testing all contribute to the overall cost of secondary care treatment. Out of these, the hospital admission and inpatient stay costs were the major contributor and were subsequently evaluated in our study. Primary care treatment and time off work financial losses were not included and are beyond the scope of this current study, but could also contribute to a negative outcome for the stenting group.
Both operative and total cost of secondary care was significantly lower in the URS group despite the fact that emergency ureteroscopic surgery had the highest individual costing tariff out of all the surgical interventions.
When subdivided into lower and upper ureteric stones, there were reduced total costs in the URS group. The lower ureteric stones showed a significant statistical difference, which was not found in the upper ureteric stones. This is most likely because of the lower stone-free rates in URS for upper ureteric stones leading to the requirement of secondary procedures, thus increasing overall costs.
This study highlights the significant extra costs, increased inpatient stay, morbidity and time for those patients who undergo primary ureteric stenting. It also shows an increased rate of readmissions (secondary care) in patients who have primary stenting.
We advocate that primary URS is a safe and effective procedure and should be considered instead of ureteric stenting as the primary treatment option in patients with ongoing, painful ureteric colic, particularly in lower ureteric stones. This evidence needs to be validated by further randomised studies on larger series of patients.
Footnotes
Acknowledgements
None.
Conflicting interests
The authors declare that there is no conflict of interest.
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Ethical approval
There are no ethical issues/concerns with the publication of this article.
Informed consent
Written informed consent was obtained from the patients for their information to be published in this article.
Guarantor
MD.
Contributorship
MD and TS researched the literature and performed data collection. NR and JI supervised the project and edited and approved the final version.