February issue.indd

An audit of 2273 ureteroscopies - a focus on intra-operative complications to justify proactive management of ureteric calculi

M.R. Butler, R.E. Power, J.A. Thornhill, I. Ahmad, I. McLornan, T. McDermott and R. Grainger
Department of Urology, The Adelaide and Meath Hospital Dublin, incorporating The National Children’s Hospital, Tallaght, Dublin 24, Ireland

Correspondence to: M.R. Butler, President of the Royal College of Surgeons in Ireland, 123 St Stephens Green, Dublin 2, Ireland
Email: richiep@eircom.net

Keywords: Ureteroscopy, ureteric calculi, complications
Surg J R Coll Surg Edinb Irel., 2 February 2004, 42-46

Background: At the National Stone Centre we have adopted a proactive management approach involving early ureteroscopy for ureteric calculi. As the efficacy of ureteroscopy is known this study focuses on the low intra-operative complication rate as justification for a proactive management protocol. Patients and Methods: A retrospective study (1987-1997) identified 1,936 patients undergoing 2,273 ureteroscopies. A database was created from inpatient hospital records. The male to female ratio was 3 to 1, age range was 25 to 84 years. Results: Twenty-three patients (1%) had an intra-operative complication during ureteroscopy. Immediate ureteric JJ stenting was performed in 16 cases with ureteric injury. Two cases underwent percutaneous drainage and delayed antegrade ureteric stenting, ureteroscopy was terminated because of poor visibility. Five patients (0.22%) underwent open surgery for: ureteric perforation (n=2); Dormia basket ureteric avulsion (n=1); impacted Dormia basket and stone (n=1); and impacted balloon dilator and stone (n=1). Ureteroscopic complications were not related to the level of ureteric calculus. Conclusion: A protocol of proactive management of ureteric calculi facilitates rapid turnover of large patient numbers. This approach is supported by the low intraoperative complication rate, most of which can be managed by further endoscopic procedures. In the event of corrective open surgery a favourable outcome has resulted

INTRODUCTION
In the last two decades lithotripsy, percutaneous nephrolithotomy and ureteroscopy have superceded the requirement for open surgery for ureteric stones.¹ Historically, the surgical treatment of ureteric calculi included cystoscopic ureteric catheterisation, ureteric dilatation, Dormia basket stone extraction, ureteric meatotomy or open ureterolithotomy.^2,3 However, the commonest approach was ‘watchful waiting’, i.e. relieve pain, observe for complications and wait for spontaneous stone passage. Sandegard (1956) outlined the fate of ureteric stones treated conservatively.⁴ For small calculi (4 mm or less) 93% pass spontaneously from the lower ureter and 81% from the upper ureter, within six weeks from onset of symptoms. Fifty per cent of medium size stones (4-6 mm) in both the upper and lower ureters pass spontaneously. Of importance, medium size stones in the upper half of the ureter were associated with a high incidence of renal complications due to obstruction. Leahy et al. (1989) examined the impact of duration of ureteric obstruction onsubsequent renal recovery, after relief of obstruction.⁵ Kidneys partially obstructed for 14 days had total immediate recovery while kidneys obstructed for 28 days recovered only 31% of total function. Kidneys partially obstructed for 60 days recover 8% of baseline function. These functional studies support an aggressiveapproach to the removal of ureteric calculi. Historically, this was not carried out due to the morbidity of open surgery and the limited efficacy of older blind endoscopic methods.

At the National Stone Centre, we have a definitive proactive management policy for ureteric calculi involving early ureteroscopy with or without ancillary treatments (lithotripsy, stenting, direct extraction etc.). This approach was adopted on the scientific basis of proven efficacy of modern endoscopic methods to prevent the potential for renal decompensation, as outlined above. Our policy is also pragmatic based on an increasing proportion of tertiary referrals who have failed conservative treatment or who have complications of stone disease (sepsis, hydronephrosis, and unremitting pain). At the time of transfer patients prefer early and definitive treatment. Thus, very few of our patients would be suitable for a further period of conservative treatment. We present our results for ureteroscopy for ureteric calculi in our institution over a 10 year period with a particular focus on intraoperative complications.

PATIENTS AND METHODS
A 10-year retrospective study (1987-1997) revealed 1,936 patients who underwent ureteroscopy for ureteric calculi. Demographic data and details of endoscopy, including repeat procedures and ancillary techniques, were extracted from hospital records. Specific details of intra-operative complications were recorded for each patient.

All procedures were performed under general anaesthesia. In the early years of the study, equipment was limited to 9.5 French calibre straight rigid ureteroscope (Wolf) and 12 French calibre offset Wolf ureteroscope. Since 1995, The 6 French semi-rigid ureteroscope (Wolf) has been available and is the most commonly used in our practice. Routine antimicrobial prophylaxis was not used except in cases where there was a positive midstream specimen of urine (MSU) or a preceding history of urosepsis.

RESULTS
One thousand, nine hundred and thirty six patients underwent a total of 2,273 procedures. A single ureteroscopic procedure was performed in 1,676 patients (87%) while 205 patients (11%) required two procedures and 44 patients (2%) underwent three or more procedures to achieve stone clearance. The male to female ratio was 3 to 1. Age range was 15 to 84 years with peak incidence in the fifth decade. Sixty-two per cent of ureteroscopies were on the right side and 38% were on the left side. In 6% of cases (n=136) ureteroscopy confirmed no ureteric calculus present. These were cases where there was radiological doubt prior to ureteroscopy or where spontaneous stone passage was suspected but unconfirmed in the presence of ongoing symptoms. Each of these cases underwent uncomplicated and full visualisation of the ureter. All these cases had a plain radiograph post procedure to exclude retrograde flushing of a ureteric stone into the kidney during ureteroscopy.

In 47.6% of cases (n=1083), a ureteric calculus was removed under direct vision using either a Dormia basket or grasping forceps. In 21.5% of cases a calculus was pushed back into the renal pelvis under direct vision, a JJ stent placed and extracorporeal lithotripsy (ESWL) performed. This was common practice in the early part of our series as our lithotripsy machine was solely ultrasound-guided. Ureteric meatotomy was performed in 6.5% of patients (n=146) to release an impacted intramural ureteric calculus.

Ureteroscopic intraluminal lithotripsy was performed in 18.4% of cases (n=418). Ultrasonic lithotripsy (USL), 8.7% of cases (n=197), was the only modality available in the early part of the study but has since been superseded by electrohydraulic lithotripsy (EHL), 9.7% of cases (n=221). Latterly, intraluminal laser lithotripsy (pulse-dye, Candella MDL 300) and lithoclast (EMS) have been introduced and used in increasing numbers.

An early protocol for ureteric stenting was defined and used in 40% of cases (n=911). An absolute indication was the identification of intra-operative ureteric trauma. Stenting was routine for impacted calculi unresponsive to attempted manipulation or insitu lithotripsy. Stenting following retrograde stone manipulation prior to ESWL, (“push-bang”) technique was also routine. This facilitated early discharge of patients often travelling long distances without the risk of sepsis or obstruction post procedure.

All intra-operative complications were identified immediately in 23 patients (1%) and treated accordingly. These included the following ureteric; perforation secondary to in-situ EHL (n=8), ureteric perforation during ultrasonic lithotripsy, (n=1); ureteric perforation using Dormia basket (despite ureteroscopic control), n=4; ureteric avulsion using Dormia basket, (n=1); retained ureteric Dormia basket, (n=1); impacted balloon dilator with calculus, (n=1); and ureteroscopicinduced superficial traumatic mucosal tear, (n=7).

Immediate ureteric JJ stenting was performed in 16 (of 20) cases with ureteric injury. In two cases of perforation attempted placement of a ureteric stent was abandoned due to poor vision and both were managed by percutaneous nephrostomy and antegrade ureteric stent insertion. The remaining two cases with ureteric perforation underwent open surgery (a total of five patients underwent open surgery). In one case the ureteric perforation was repaired over a ureteric stent, as prior to exploration it was feared that the ureter had been avulsed. In the remaining case of ureteric perforation, the stone was removed by open pyelolithotomy and the perforation closed at the ureteropelvic junction. Three further patients required open surgical intervention. The patient with ureteric avulsion during Dormia manipulation of a ureteric stone underwent end-to-end repair of the ureter in its upper third. Two cases, one with a retained basket with ensnared stone and one with an impacted balloon dilator, underwent open ureterolithotomy and removal of the Dormia and balloon dilator, respectively
(Table 1).

DISCUSSION
Hampton Young performed ureteroscopy in 1912 in an infant with massively dilated ureters using a cystoscope, which advanced easily to the renal pelvis.⁶ Marshall described fiberoptic ureteroscopy in 1964 and the first purpose built ureteroscope was reported in 1979.⁷ The new generation small bore rigid and semi-rigid fiberoptic ureteroscopes have become integral to the modern management of ureteric calculi. Open ureterolithotomy is rare except in a select sub-group of patients i.e. those with complex calculus disease associated with anatomic abnormalities.

We have adopted a proactive approach in favour of endoscopic management for ureteric calculi and this is irrespective of site and size. The rationale for this approach is several fold. Ureteroscopy has become as effective as open surgery with little attendant morbidity. Early intervention and relief of an obstruction precludes the development of renal obstructive complications.⁵ With modern lifestyles and demands of the work place patient preference is for rapid diagnosis and early removal of ureteric calculi. With the concentration of specialist resources and personnel and the development of appropriate equipment there is a window of opportunity for safe and efficient treatment. As in other studies, the majority of patients are treated either as day cases or during a very brief hospital stay. Our ureteric stenting rate of 40% might be considered high by current standards in some centres. However, in our experience the low threshold for ureteric stents after ureteroscopy tends to improve hospital stay. Obviating the risk of post-operative sepsis or obstruction facilitates early discharge, and often to distant rural areas.

This study did not set out to repeat others on the efficacy of ureteroscopy and ancillary procedures in achieving stone clearance. That data is well established and new technology would render stone free rates from the early part of this study of historical interest only. The ureteral clinical guidelines panel of the AUA in a meta analysis of ureteric endoscopy over a similar time frame reported stone free rates of 72% for proximal stones and 90% for distal stones.⁸ The focus of this article was on intra-operative complications and the 0.22% of patients requiring open surgery is comparable with results described by Jeromin et al.(1998).⁹ In his series of comparable size, the conversion rate to open surgery was also 0.2%. In our series, complications leading to open surgery were not related to the site of calculus and this supports the view of Erhard et al.(1996) who strongly advocated ureteroscopy as the treatment of choice for upper ureteric calculi.¹⁰ Hollenbeck et al. (2001) have since reported comparable success rates when treating proximal and distal ureteric calculi.¹¹ Pearle et al.(2001) compared ESWL and ureteroscopy for distal ureteric calculi.¹² While both modalities were equally successful with low complication rates, ureteroscopy was the more cost-effective treatment. Patient satisfaction was uniformly high regardless of treatment modality. We favour ureteroscopy as it ensures a more certain and immediate outcome which facilitates the early and definitive discharge of patients. Our study confirms previous observations that the majority of ureteric perforations can be treated conservatively by endoscopic insertion of a ureteric stent.^13,14 We did not examine risk factors for complications but others have implicated prolonged surgery time, an inexperienced surgeon and ureteroscopic treatment of intrarenal calculi as important factors.¹⁵ Extra-ureteric extrusion of calculi due to perforation is well documented but Kreigmair and Schmellar (1995) have shown this to be a minor complication of ureteroscopy and only rarely leads to stricture formation.¹⁶

There are a number of recommended protocols for post-operative followup and imaging after ureteroscopic removal of a ureteric calculus. Weizer et al.(2002) recommend ultrasound, excretory urography or computerised tomography (CT) scan within three months of routine uncomplicated ureteroscopic stone management to detect silent obstruction.¹⁷ Others would argue that routine radiological surveillance for obstruction is not required in asymptomatic patients.^18,19,20

Cost factors, medico-legal issues, and burden of patient numbers influence different institutional practices. Roberts et al. (1998) indicated that ureteric stone impaction and perforation is the primary risk factor for subsequent stricture formation.²¹ We limit follow-up excretory urography (or spiral CT scan) to those few patients where there has been suspected trauma. The vast majority of other “routine” patients do not have functional radiological examination at follow-up, they simply have a KUB plain radiograph. Our lack of routine functional radiological follow-up could mean that cases of delayed ureteric stricture after apparent routine endoscopy were missed. From the studies cited above those cases should be isolated occurrences, and mainly from the early part of the series when only the larger calibre ureteroscope was available.

Considering the highly effective known outcome of ureteroscopy for ureteric calculi we adopted a proactive approach to the management of ureteric stones. This is particularly relevant to the tertiary referral setting where many patients have complicated stones (obstructed, with unremitting pain) or who have already had a period of conservative “treatment” - waiting. Perhaps our low threshold for ureteroscopy can be criticised because 6% of cases had no ureteric calculus at endoscopy, thus indicating spontaneous stone passage. However, ureteroscopy achieved a definitive diagnosis in these patients with residual symptoms and they could be discharged with confidence, many to peripheral rural areas. Our low intra-operative complication rate, the focus of this article, supports this approach. Complications are infrequent and when they occur can generally be treated endoscopically. Open surgery for the management of complications is rare and even when necessary leads to favourable outcome. A further prospective study, limited to the new technologies that have supplanted the old wider calibre ureteroscopes and lithotripsy/ extraction devices, should be conducted to determine if the low intra-operative complication rate is reducing further.

REFERENCES
1. Ather MH, Paryani J, Memon A, Sulaiman MN. A 10-year experience of Managing ureteric calculi: Changing trends towards endourological intervention - is there a role for open surgery? BJU Int 2001; 88: 173-7.
2. Butler MR, O’Flynn JD. Management of ureteric calculi: a review of 500 cases. J Ir Med Assoc 1973; 66: 1-4.
3. O’Flynn JD. The treatment of Ureteric Stones. Report on 1120 patients. Br J Urol 1980; 52: 436-8.
4. Sandegard E. Prognosis of stone in the ureter. Acta Chirurgica Scandinavica Supplementum. 1956.
5. Leahy AL, Ryan PC, McEntee GM, Nelson AC, Fitzpatrick JM. Renal injury and recovery in partial ureteric obstruction. J Urol 1989; 142: 199-203.
6. Young HM, McKay RW. Congenital valvular obstruction of the prostatic urethra. Surg Gynecol Obstet 1929; 48: 509.
7. Marshall VF. Fiberoptics in Urology. J Urol 1964; 91: 110.
8. Segura JW, Preminger GM, Assimos DG, Dretler SP, Kahn RI, Lingeman JE, Macaluso JN Jr. Ureteral stones clinical guidelines panel summary report on management of ureteral calculi. The American Urological Association. J Urol 1997; 158: 1915-21.
9. Jeromin L, Sosnowski M. Ureteroscopy in the treatment of ureteral stones: over 10 years’ experience. Eur Urol 1998; 34: 344-9.
10. Erhard M, Salwen J, Bagley DH. Ureteroscopic removal of mid and proximal ureteral calculi. J Urol 1996; 155: 38-42.
11. Hollenbeck BK, Schuster TG, Faerber GJ, Wolf JS Jr. Comparison of outcomes of ureteroscopy for ureteral calculi located above and below the pelvic brim. Urology 2001; 58: 351-6.
12. Pearle MS, Nadler R, Bercowsky E, Chen C, Dunn M, Figenshau RS et al. Prospective randomized trial comparing shock wave lithotripsy and ureteroscopy for management of distal ureteral calculi. J Urol 2001; 166: 1255-60.
13. Karmouni T, Patard JJ, Bensalah K, Manunta A, Guille F, Lobel B. Urologic management of ureteral iatrogenic lesions. Prog Urol 2001; 11: 642-6.
14. Kostakopoulos A, Sofras F, Karayiannis A, Kranidis A, Dimopoulos C. Ureterolithotripsy: report of 1000 cases. Br J Urol 1989; 63: 243-4.
15. Schuster TG, Hollenbeck BK, Faerber GJ, Wolf JS Jr. Complications of ureteroscopy: analysis of predictive factors. J Urol 2001; 166: 538-40.
16. Kriegmair M, Schmeller N. Paraureteral calculi caused by ureteroscopic perforation. Urology 1995; 45: 578-80.
17. Weizer AZ, Auge BK, Silverstein AD, Delvecchio FC, Brizuela RM, Dahm P et al. Routine postoperative imaging is important after ureteroscopic stone manipulation. J Urol 2002; 168: 46-50.
18. Bugg CE Jr, El-Galley R, Kenney PJ, Burns JR. Follow-up functional radiographic studies are not mandatory for all patients after ureteroscopy. Urology 2002; 59: 662-7.
19. Carter SS, Cox R, Wickham JE. Complications associated with ureteroscopy. Br J Urol 1986; 58: 625-8.
20. Karod JW, Danella J, Mowad JJ. Routine radiologic surveillance for obstruction is not required in asymptomatic patients after ureteroscopy. J Endourol 1999; 13: 433-6.
21. Roberts WW, Cadeddu JA, Micali S, Kavoussi LR, Moore RG. Ureteral stricture formation after removal of impacted calculi. J Urol 1998; 159: 723-6.

Applications are invited from those (Dental) Fellows or Members of the Royal College of Surgeons of Edinburgh wishing to be considered for a limited number of vacancies on the panel of examiners for the Membership Diploma in Special Needs Dentistry (M.SND RCSEd) Examination.

Faculty of Dental Surgery
The Royal College of Surgeons of Edinburgh
10 Hill Square
Edinburgh EH8 9DW
Email: dental@rcsed.ac.uk

TABLE 1. INTRA-OPERATIVE COMPLICATIONS OF URETEROSCOPIC STONE TREATMENT AND IMMEDIATE REMEDIAL ACTION
Patient numbers	Injury	Remedial Action
16	Ureteric mucosal tearing/perforation	Ureteroscopic JJ stent
2	Ureteric mucosal tearing/perforation	Percutaneous drainage and antegrade passage of JJ stent
1	A large ureteric perforation during extraction of a calculus within a basket (suspected avulsion)	Open repair of ureter over a JJ stent
1	Perforation of the PUJ during EHL of a calculus	Open pyelolithotomy and closure over a JJ stent
1	Ureteric avulsion during extraction of a calculus within a basket	Laparotomy and end-to-end repair of the ureter in its upper third
1	A dormia basket became impacted in the mid-ureter after engaging a large calculus	Open ureterolithotomy and release of the basket and closure over a JJ stent
1	During balloon dilation of the lower ureter the balloon became engaged with a calculus and could not be withdrawn	Open ureterolithotomy and release of the balloon and closure over a JJ stent