A 10-year experience of managing ureteric calculi: changing trends towards endourological intervention—is there a role for open surgery?

Abstract

Objectives To study changing practices in the management of ureterolithiasis with the introduction of newer technologies, the efficacy and safety of endourology, extracorporeal shock wave lithotripsy (ESWL) and open surgery, and to determine if any indication remains for open ureterolithotomy in a tertiary endourology unit.

Patients and methods A 12-year retrospective review (1987–1998) was conducted of all primary ureteric stones treated by ESWL, endoscopy, intracorporeal shock wave lithotripsy (ISWL) administered via ureteroscopy, and open surgery.

Results In all, 1195 patients were treated for primary ureteric stones, 44% by ESWL, 37% by ureteroscopy and ISWL, and 20% by open surgery. At the 3-month follow-up the stone-free rates for ESWL monotherapy, ureteroscopy and open surgery were 95%, 85% and 97%, giving an efficiency quotient of 73%, 64% and 94%, respectively. The overall complication rate for ESWL was 13%, for ISWL 32% and for open surgery 13%, but the complications of open surgery were often serious and potentially life-threatening.

Conclusions With recent advances in endourology the indications for open surgery have decreased considerably, from 26% in 1987–95 to 8% in 1996–98. However, the remaining indications for open ureterolithotomy include failure of less invasive modalities, the presence of medical/anatomical abnormalities, a concomitant open procedure, and the presence of large impacted calculi for which patients prefer to avoid multiple procedures.

Introduction

Technological developments in the last two decades have precipitated a dramatic change in the way ureteric stones are treated. Advances in equipment and the design of shock wave lithotripters, both for ESWL and intracorporeal shock wave lithotripsy (ISWL), the development of endourological equipment and improving skills with these modalities, have greatly diminished the role of open surgery in managing ureteric calculi. We reviewed our experience over the last 10 years to assess changing practices in managing ureteric lithiasis with the introduction of newer technologies, the efficacy and safety of endourology, ESWL and open surgery, and to determine the current indications for ureterolithotomy in a centre well-equipped with a second-generation lithotripter and mini-ureteroscopes with ISWL (electrohydraulic, ultrasonic and pneumatic lithotripsy).

Patients and methods

The records of patients with ureteric stones treated at a University Hospital between January 1987 and December 1998 were reviewed. Computer-generated lists of patients with a diagnosis of ureteric stones were obtained from the Indexing and Coding Unit. The patients were then included in the study if the stone was documented by a radiographic study, the stone was within the ureter at the time of intervention and there was intervention with consequent removal of the calculi. Only patients with single primary ureteric calculi were included in the study. Patients with multiple calculi at different sites, steinstrasse after ESWL and calculi pushed back for ESWL were excluded.

The hospital and clinic charts, operative notes and records, and pertinent radiographic studies of all the patients were reviewed. Patient characteristics assessed included age, gender and relevant medical history. The stone characteristics assessed included side, site and size. For the purpose of this study, stone size was determined in two dimensions; size 1 is perpendicular to the long axis of the ureter, which has been shown to be the most accurate index for predicting stone passage [1]; and size 2 is parallel to the long axis of the ureter. The stone site was determined using the sectional anatomy of the ureter initially proposed from our institution in 1994 [2] (Fig. 1). Additional factors assessed were pertinent to the different treatment modalities used. For patients treated by open surgery, perioperative complications, estimated blood loss and inpatient stay were also assessed. For patients treated by ureteroscopy the size of the ureteroscope used, method of ISWL, ancillary procedures, and complications during and immediately after ureteroscopy were also assessed. All patients in the ESWL group were treated using an echo-guided lithotripter (MPL-9000™, Dornier GmBh, Germany). The additional variables assessed in patients treated by ESWL included the number of shock waves and treatment sessions, complications and the use of ancillary procedures. Using the efficiency quotient [3], the efficacy of treatments was assessed objectively, using the formula: (stone-free percentage × 100)/(100 + (re-treatment rate percentage + ancillary procedure percentage)).

Figure 1. Anatomical subdivision of the ureter. Section 1, ureter from the PUJ to the lower border; section 2, 2.5 cm below (all stones in section 1 and most in section 2 can be localized and fragmented using an echo-guided lithotripter); section 3, up to upper border of the sacro-iliac joint; section 4, parallel to sacro-iliac joint; section 5, up to ischial spine; section 6, up to vesico-ureteric junction. All stones in section 6 and most in section 5 are focused by an echo-guided lithotripter (reproduced with permission from Blackwell Science)

Reasons for selecting ureteroscopy-ISWL, ESWL and open surgery were determined from the clinic notes and preoperative or indication notes. Structural abnormalities were established from the documentation, the diagnostic notes of the surgeon and all preoperative radiographic studies. Postoperative notes, clinic charts, postoperative radiographic studies and all postoperative diagnostic or therapeutic procedures established the residual stone burden. At least 3 months of follow-up were completed in all patients after the last treatment.

Results

During the study period, 1195 patients with primary ureteric stones were treated; ESWL was the most common method (43.4%), followed by ureteroscopy-ISWL (36.6%) and open surgery (20%). The relative distribution of the various treatments used in different years is shown in Fig. 2. All patients with ureteric calculi in sections 1 and 2 were treated with ESWL unless there was a problem locating the stone using the echo-guided lithotripter. Patients with calculi in distal section 5 and 6 were offered ureteroscopy-ISWL or ESWL, with an explanation of the respective advantages and disadvantages. Stones in section 3, 4 and proximal section 5 were exclusively treated by ureteroscopy-ISWL, unless they were large, impacted or if ureteroscopy was contraindicated for other reasons. The indications for open surgery are detailed in Table 1. As a single and not dual location method was used in ESWL, stones at certain sites were an automatic exclusion criterion; this handicap biased the decision towards using more endourological procedures for stones that could not be located on the echo-guided lithotripter.

Figure 2. Treatment modalities (ureteroscopy, green circles; ESWL, red squares; open surgery, light green triangles) used for ureteric lithiasis between 1987 and 1998.

Table 1.  Indications of open surgery; group 1 (1987–95) were treated during the period before the introduction of pneumatic lithotripsy, and group 2 afterwards

Indication	Group 1 (208)	Group 2 (32)
n (%)
Anatomical abnormalities	84 (40)	12 (38)
Failure of procedure	81 (39)	10 (31)
Patient preference	21 (10)	1 (3)
Impacted large stone	14 (10)	7 (22)
Concomitant open	8 (4)	2 (6)

In the ESWL group, there were 518 patients (399 males and 119 females, mean age 38.6 years, range 11–75, sd 12). The mean (sd, range) for size 1 and 2 were 1.1 (0.52, 0.3–3.5) cm and 0.9 (0.3, 0.3–2.0) cm. Three-quarters of the patients had only one session of ESWL (390, 75.3%), a fifth had two sessions (107, 20.7%) and only 4% required more than two sessions of ESWL. More than three-quarters of the stones were either in section 1 (238, 46%) or section 6 (157, 30.3%), with others in section 2 (97, 18.7%) and section 5 (26, 5%) (Table 2). There were 240 right-sided and 278 left-sided calculi. The mean (sd) number of shock waves administered was 3013 (1960). Twenty-eight (5.4%) patients had persistent (> 3 months) residual calculi or treatment failure for which salvage procedures were undertaken; ureteroscopy with ISWL was used in 26 patients (5%), open surgery in one and one underwent cystolitholapaxy for a significant fragment in the bladder after treatment for a pre-vesical calculus. Overall, at 3 months of follow-up, 492 patients (95%) were rendered stone-free with ESWL monotherapy, giving an efficiency quotient of 73%. The overall complication rate was 13.3% (69). Urosepsis and simple UTI were the commonest complications (Table 3), seen in 34 patients (6.6%), followed by steinstrasse in 15 (3%) and pain requiring inpatient stay and parenteral analgesics in 20 (4%).

Table 2.  Distribution of stones in various sections of the ureter (see Fig. 1)

Section	ESWL	ISWL	Open
n (%)
1	238 (46)	16 (4)	8 (3)
2	97 (19)	46 (11)	65 (27)
3	–	98 (22)	72 (30)
4	–	55 (13)	65 (27)
5	26 (5)	102 (23)	22 (9)
6	157 (30)	120 (27)	8 (4)

Table 3.  Complication profile of the three modalities

Complication, n (%)	ISWL	ESWL	Open
Number of procedures	437	518	240
UTI/Urosepsis	29 (7)	34 (7)	22 (9)
Haematuria and dysuria	41 (9)	–	–
Perforation of ureter	40 (9)	–	1 (0.4)
Anaemia	–	–	1 (0.4)
Paralytic ileus	–	–	3 (1)
Pain	28 (6)	20 (4)	–
Respiratory insufficiency	–	–	1 (0.4)
Anuria (increased creatinine)	–	–	1 (0.4)
Myocardial infarct	–	–	1 (0.4)
Pulmonary oedema	–	–	1 (0.4)
Steinstrasse	–	15 (3)	–

The group treated by ureteroscopy comprised 437 patients (36.6%, 342 males and 95 females, mean age 35.4 years, range 18–70, sd 11.2). The mean (sd, range) for size 1 and 2 were 0.73 (0.5, 0.3–2.6) cm and 0.6 (0.4, 0.5–2.4) cm. There were 298 right-sided and 107 left-sided calculi, with 32 patients having bilateral calculi. Between 1987 and 1995, ultrasonic and electrohydraulic lithotripsy (EHL) were used to fragment the stones. From 1996 all patients were treated using a pneumatic lithotripter. Table 4 shows a comparison of the variables in the groups treated by ultrasound + EHL and pneumatic lithotripsy. Stones were distributed throughout the length of ureter (Table 2). Complications occurred in 138 patients (32%), including pain requiring parenteral analgesics in 28, UTI with fever in 29, and 41 with dysuria and haematuria necessitating parenteral antibiotics and inpatient stay (Table 4). Seventy-eight patients had minor ureteric mucosal injury which required no extra procedure, whereas 40 patients had a ureteric mucosal/transmural injury necessitating no more than placement of a percutaneous nephrostomy in eight and JJ stents in 32. Ancillary procedures were required in 86 patients (20%); 50 required open ureterolithotomy whereas ESWL was used in 36 (Table 4). In all, 411 (94%) patients had a single session of ureteroscopy, whereas 6% required a repeat ureteroscopic procedure for residual calculi. The overall stone-free rate with ureteroscopy + ISWL monotherapy was 80% (351), giving an efficiency quotient of 64%.

Table 4.  Comparison of groups treated by electrohydraulic lithotripsy plus ultrasound with pneumatic lithotripsy

Variable	Ultrasound + electrohydraulic	Pneumatic
Period	1987–96	1996–98
Number (%)	223 (51)	214 (49)
Stone distribution (n) in section:
1	2	14
2	3	43
3	36	72
4	26	29
5	66	36
6	90	30
Complications
Pain	18	10
UTI	13	16
Haematuria	31	10
Minor mucosal injury	30	48
Significant mucosal/  transmural	28	12
Ancillary procedure
Convert to open	46	4
ESWL	20	16

Overall, 240 (20%) patients (182 males and 58 females, mean age 40 years, range 14–72, sd 12.9) underwent open ureterolithotomy for primary ureteric calculi; the change from 1987 to 1998 is shown in Fig. 2. The mean (range) for size 1 and 2 were 1.6 (0.8–3.0) cm and 1.7 (0.6–2.6) cm; the stone site is shown in Table 2. There were 132 right-sided and 108 left-sided calculi. Seven patients (3%) required ancillary treatment for missed residual calculi; five underwent lithotripsy whereas two required ureteroscopy and ISWL. Complications occurred in 31 (13%) patients and are shown in Table 3. The mean (sd) operative duration was 92 (29.4) min, with an estimated blood loss of 202.9 (320) mL (five patients required perioperative transfusion totalling 6 units); the hospital stay was 4.7 (1.4) days. The indications for open surgery are shown in Table 1. The overall stone-free rate was 97% and the efficiency quotient 94%.

Ten patients underwent open ureterolithotomy because of concurrent open procedures. The primary open surgical interventions were; Caesarean section, open cholecystectomy and pyeloplasty in one patient each; abdominal hysterectomy, tuberculous ureteric stricture in two each; and in three simultaneous open renal surgery for staghorn calculi.

Discussion

In the last 5 years there have been few publications about the role of open ureterolithotomy [4–7]; there remains a significant lack of comparative analyses of open surgery with minimally invasive treatment options, including both ESWL and ISWL. We therefore reviewed our experience of managing ureteric calculi over the last decade to determine the current indications of open surgery, and the safety and efficacy of the three methods.

Minimally invasive surgery has inherent advantages: (i) because the insult to the body is minimized there is a rapid recovery, short convalescence and an early return to work; (ii) as there is minimal anatomical distortion, future surgery is technically less tedious; (iii) for most procedures day-case surgery helps to reduce the increasing burden on inpatient beds.

Assessing the morbidity of endourology and ESWL in comparison with invasive options (open ureterolithotomy) should provide a scientific basis for decision-making in selecting options. Besides the long- and short-term safety and efficacy, other factors that determine the indications for open surgery includes patient characteristics, the availability of endourological equipment, and the experience and inclinations of the urologist. The present indications for ureterolithotomy at centres well-equipped with endourology and ESWL has not been adequately defined in recent reports.

Upper and lower ureteric stones are probably best managed by in situ ESWL [8,9]; ureteroscopy has similar safety and efficacy for distal ureteric calculi. With the recent introduction of finer semi-rigid and flexible ureteroscopes there is an increasing trend to the ureteroscopic management of even upper ureteric stones [10]. For mid-ureteric stones the choice of treatment is influenced by stone size, presence of stone impaction, availability of fine flexible or semi-rigid ureteroscopes and effective ISWL methods (laser, pneumatic lithotripsy) and the patient's wish to avoid multiple treatment sessions [11].

Anatomical abnormalities (ureteric stricture, abnormally tortuous ureter) and failed less invasive options (ESWL, endoscopy, ‘push-bang’) constituted the major indications for open surgery (40%). A significant number of patients (9%) when given an option of combined treatment (ESWL + ISWL), multiple sessions of ureteroscopy and open ureterolithotomy, opted for the latter. Patients with large impacted calculi (9%), with more than two sessions of ureteroscopy anticipated, were offered ureterolithotomy as an alternative. Patients who underwent open surgery after the failure of minimally invasive options included 54 in whom there was adequate access to the calculus but fragmentation was not possible either because the stone migrated or there was mucosal injury (obscuring vision), making further treatment difficult. One patient had open surgery after failed ESWL. In 36 patients ureteroscopic access failed because it was not possible to negotiate the ureteric orifice and intramural ureter. The factors responsible for ureteroscopy failure included larger calibre ureteroscopes, lack of experience and EHL-related mucosal injury, in that order.

Conversion to open surgery after an initial ureteroscopic attempt was significantly greater in the period up to 1995, attributed primarily to the use of larger calibre ureteroscopes and to the use of EHL. Since the introduction of finer ureteroscopes and pneumatic lithotripsy only four patients required conversion to open surgery. Most patients with significant mucosal and transmural injury in the earlier period were treated conservatively by either JJ stenting, if possible, or by percutaneous diversion and antegrade JJ stenting under local anaesthesia in the radiology suite.

Comparing indications for 1987–1995 and 1996–1998 (when the lithoclast was introduced) showed no significant difference except that with finer ureteroscopes more patients with large impacted calculi underwent open surgery (22% vs 10%). In 1996–1998, only 8% patients were treated by open surgery, 52% by ureteroscopy-ISWL and 40% by ESWL. The rate of open surgery declined from 32% in 1988 (when all three methods were available) to 5% in 1998. The rate of open surgery is higher than that reported recently [4–7].

Although the complication rate of open ureterolithotomy (13%) was comparable with that from ESWL (13.3%) and much lower than ureteroscopy (32%), the effect was significant, as those from open ureterolithotomy were serious and potentially life-threatening, including myocardial infarction, respiratory insufficiency, pulmonary oedema and paralytic ileus.

Of the few remaining indications for open surgery probably the most important is the presence of a large impacted calculus and the patient's preference to avoid multiple procedures. With the introduction of finer ureteroscopes and safer ISWL, conversion to open surgery is rare. Concomitant open procedures constitute a relative indication, with Caesarean section probably being the only valid indication because of the diagnostic and therapeutic difficulties during pregnancy. In all other situations the easy availability of radiological diagnostic tools makes it unlikely that two pathologies are diagnosed simultaneously.

The current indications for open ureterolithotomy in a well-equipped endourological centre are limited; they include high-risk patients precluding multiple general or major regional anaesthesia, anatomical conditions of the ureter difficult to manage endoscopically, any inability to position patients for ureteroscopy (e.g. orthopaedic conditions of the hip joint), failure of minimally invasive methods, a large impacted calculus with the patient preferring a single treatment at the time of Caesarean section. These indications are further reduced by the availability of finer rigid and flexible ureteroscopes. However, because of their high maintenance and operational cost [12], their uniform availability cannot be assured in most urological units worldwide. In well equipped urological centres with support facilities for flexible equipment breakdown, open ureterolithotomy is a rare procedure.