What is the best way to manage ureteric calculi in the time of COVID‐19? A comparison of extracorporeal shockwave lithotripsy (SWL) and ureteroscopy (URS) in an Australian health‐care setting

Abstract Objectives To determine the best way to intervene for ureteric stones which still require treatment during the COVID‐19 pandemic, with respect to infection control. In this setting, in which resources are constrained, extracorporeal shockwave lithotripsy (SWL) has prima facie advantages over ureteroscopy (URS). It is also necessary to also consider posttreatment resource consumption in regards to complications and repeat procedures. Subjects and methods The ideal ureteric stone treatment during a pandemic such as COVID‐19 would involve minimum resource consumption and a minimum number of patient attendances. We compared all patients initially treated with SWL to those initially treated with URS for acute ureteral colic within the state of Victoria, Australia in 2017. Results A total of 2724 ureteric stones were analyzed, a cumulative “3‐month exposure and burden on the healthcare system” was calculated for each patient by their initial procedure type. The readmission rate for URS was significantly higher than for SWL, 0.92 readmissions/patient for URS versus 0.54 readmissions/patient for SWL (P < .001). The cumulative hospital stay per patient for these two procedures was 2.35 days for SWL versus 3.21 days for URS (P < .001). The number of procedures per patient was 1.52 for SWL versus 1.89 for URS (P = .0213). Conclusions Patients with ureteric stones treated initially by SWL have shorter length of stay with fewer overall attendances and procedures at 3 months than those treated with URS. During a pandemic such as COVID‐19, SWL may have benefits in preserving hospital resources and limiting opportunity for virus transmission, compared to URS.

The European Association of Urology (EAU) has published guidelines that during the COVID-19 pandemic, urgent ureteric stones should be temporized with a ureteric stent, preferably placed at the bedside. 8 This approach is sensible in the setting of a critically overburdened health-care system. In that situation the choice between URS and SWL is not immediately relevant.
However, at different times during the pandemic, many healthcare systems are operating without excessive workloads, with suppressed numbers of community COVID-19 cases. 9 In this situation, it seems reasonable to definitively treat the ureteric stone and thereby avoid stent-related morbidity and later complications (stent encrustation, urinary tract infections, and colic pain/bladder irritation). 10 At the same time, it remains paramount to conserve PPE supplies and reduce patient attendances, and hence, potential COVID-19 transmission to and from health-care workers. Therefore, the question remains for urologists as to how to most efficiently treat ureteric stones over the course of the COVID-19 pandemic. SWL has advantages over URS, with no operating team or body fluid exposure, potentially less need for anesthesia and airway manipulation, and therefore, in the first instance fewer health-care workers involved and less PPE required.
This current study seeks to look more broadly at the real post-procedure care requirements, in order to ascertain if the advantages of SWL are maintained when subsequent emergency department presentations, further procedures and hospital admissions are considered. Follow-up imaging in these patients occurred via ultrasound, plain x-ray, or computer tomography scan (ultra-low dose when appropriate). 11 Both SWL and URS continue to evolve with the implementation of new technology. There is variation in published prospective studies that compare SWL to URS; some studies measure the stone-free rates after the initial procedure as a primary outcome, while others after additional subsequent procedures. 12 One study found that for stones <10 mm in diameter, there was no significant difference in stone-free rates between URS and SWL, however, URS was more effective for stones >10 mm. 6 In terms of cost, URS is significantly more expensive than SWL, It is also more common for a stent to be inserted during URS, which would accrue a cost in also removing the stent. A recent systematic review concluded that at a population level, first-line SWL should be the first choice treatment for ureteric stones <10 mm. 12

| Study design
We analyzed hospital admission data from the Victorian Admitted

| End points
Stone complications were defined as any stone-related admission with renal colic, urinary tract infection, or requiring stone-related surgery within 3 months. A cumulative "3-month exposure and burden on the healthcare system" was calculated for each patient by their initial procedure type, this incorporated overall length of stay, emergency presentations, number of readmissions, and subsequent procedures required.

| Statistical analysis
Calculations were performed using Stata/MP version 13.0 for Mac (StataCorp LP). Variables were checked for skewness and kurtosis to determine normality. Clinical and demographic features are presented as medians [interquartile range] and means (± standard deviation) for nonparametric and parametric data, respectively.
Differences between continuous parametric variables were examined with the t test; the Wilcoxon rank-sum test or the Wilcoxon-Mann-Whitney test were used for non-normally distributed continuous and ordinal variables, while differences between dichotomous variables were evaluated with the χ 2 test or the Fishers exact test (Tables 1-3). P-values throughout the results were two sided. About 71% of patients undergoing SWL were male versus 73% of patients undergoing URS (P = .337). The median age for both SWL and URS patients was 47 years old (P = .844). Mean length of stay (LOS) for URS procedures was significantly longer than for SWL procedures, 1.52 days versus 1.10 (P = .0003). Furthermore 76% of SWL patients (120/157) were discharged home on the same day as their procedure, compared to 38% of URS patients (975/2567), (P < .0001).

| RE SULTS
In the 3 months following the initial ureteric stone treatment, we observed 201 emergency presentations relating to renal colic, UTI with/without fever, hydronephrosis, and other stone-related symptoms. Of those, 11 corresponded to SWL patients (incidence 7.01%), and 190 for URS patients (incidence 7.40%), (P = .092) ( A cumulative "3-month exposure and burden on the healthcare system" was calculated for each patient by their initial procedure type (

| D ISCUSS I ON
For the patient requiring definitive treatment of a ureteral stone, URS and SWL are the two most commonly used treatment modalities. The current AUA stone management guidelines based on a 2012 Cochrane review, recommend that SWL is the procedure with the least morbidity and lower complication rate compared with URS for the treatment of a single ureteric calculus. 13 Our large population study further supports this over a 3-month period following surgery; this is relevant in the setting of a pandemic where resources need to be conserved and contact between patients and health-care workers needs to be minimized.
Health-care workers performing physical examinations or are exposed to a patient during aerosol generating procedures such as endotracheal intubation are more likely to contract COVID-19 than those without such exposures. 14,15 The first-generation lithotripter used for SWL required general anesthesia for treatment, however, current generations can be used with a variety of anesthesia techniques, ranging from general anesthesia to just oral analgesia. 16 In our study, the rate of intubation was significantly higher in URS patients (97%) compared to SWL patients (89%), (P < .001); this rate can be reduced further for SWL in a pandemic.
Hospitals in the early outbreak of the pandemic began to struggle to obtain appropriate equipment such as N95 respirators and personal protective equipment. Subsequently the surgical capacity of hospitals was reduced and elective surgeries were canceled and postponed. 17 The PPE that remains must be used judiciously for urgent procedures such as urgent ureteric stone surgery. Hence, the higher number of hospital attendances per patient for URS,  In practice, some ureteric stone patients will not be suitable for SWL (eg, cases of severe obesity or uncorrected coagulopathy). 18 However, for most ureteric stones, the decision between URS and SWL comes down to a variety of considerations, and the overall resource consumption and extent of exposure, as considered in this study, may often be decisive during a pandemic. Uric acid stones (up to 10% of renal stones) are radiolucent, and therefore, not easily targeted for SWL, but these are likely to be most efficiently treated with medical dissolution therapy rather than SWL or URS. 19

| CON CLUS ION
This population study suggests that SWL requires less health-care resources than URS over a 3-month period for the management of ureteric stones requiring urgent treatment. This information is useful during a pandemic such as the COVID-19 outbreak where the aim is not only to clear ureteric stones, but also to conserve PPE and reduce the opportunities for infectious disease transmission.