Matched pair analysis of ureteroscopy vs. shock wave lithotripsy for the treatment of upper ureteric calculi.

There is controversy over whether shock wave lithotripsy (SWL) or ureteroscopy (URS) is the best management of ureteric calculi, especially for stones located in the upper ureter. This study compares URS and SWL management of upper ureteric stones directly for the first time using a different analysis tool, the matched pair analysis study design. This method enables meaningful comparisons to be made on a small number of matched patients, using precise like-for-like matching. Adult patients undergoing primary treatment of solitary radiopaque proximal ureteric stones were identified. Patients with stents, nephrostomies or stones at the pelvi-ureteric junction were excluded. Patients had a minimum of 3 months follow-up. Patients treated by primary URS were matched using four parameters (sex, laterality, stone size and location) to patients treated on a Dornier Compact Delta Lithotriptor. A total of 1479 patients had URS or SWL from which 27 upper ureteric stone matched pairs were identified. Three-month stone free rates were 82% for URS and 89% for SWL (McNemar's test, p=0.625). Re-treatment was required in 11% and 26% following URS and SWL respectively (p=0.219). Forty-one per cent of URS patients required an ancillary treatment, such as stent removal, compared with only 22% of SWL patients (p=0.227). Introduction of a holmium:YAG laser for use with URS improved the stone free rate for URS to 100%. Using a robust like-for-like comparison of similar patients with very similar upper ureteric stones the outcomes following SWL and URS were comparable. Choice of treatment should therefore be based on parameters such as availability of equipment, waiting times and patient preference.

Patient selection before endopyelotomy: can it improve the outcome?

OBJECTIVE: To compare endopyelotomy and primary reconstructive procedures in patients with pelvi-ureteric junction (PUJ) obstruction and with risk factors for endopyelotomy failure. PATIENTS AND METHODS: Nineteen patients (eight female and 11 male, mean age 34.5 years, range 15-82) underwent endoluminal ultrasonography (US) before treatment for PUJ obstruction; the US findings were used to direct the treatment. Patients with unavoidable crossing vessels, massive hydronephrosis and crossing vessels associated with previous failed endopyelotomy were selected for reconstructive surgery. The clinical results of these patients (group 1) were compared with 12 consecutive patients who had undergone endopyelotomy before the use of endoluminal ultrasonography (group 2). RESULTS: Imaging detected 17 crossing vessels in 13 of the 19 patients. Six patients underwent primary reconstructive surgery and 13 underwent endopyelotomy. The endoluminal US findings changed treatment in some way in nine patients. Endopyelotomy was successful in 12 of the 13 patients and reconstructive surgery successful in five of six patients. The success after endopyelotomy improved from eight in 12 patients in group 2 to 12 of 13 in group 1 (P = 0.16, NS). CONCLUSIONS: Endoluminal US can be used to select patients in whom endopyelotomy is likely to fail. Using primary reconstructive procedures in these patients might improve the overall outcome, but these preliminary findings need to be confirmed in a larger study.

A prospective study of endoluminal ultrasound versus computerized tomography angiography for detecting crossing vessels at the ureteropelvic junction.

PURPOSE: Crossing vessels at the ureteropelvic junction are associated with bleeding complications and a higher risk of failure after endopyelotomy. We compared computerized tomography (CT) angiography and endoluminal ultrasound for detecting crossing vessels before planned endopyelotomy. MATERIALS AND METHODS: Preoperatively patients underwent CT angiography. Intraoperative evaluation included retrograde ureteropyelography, endoluminal ultrasound and ureteroscopy. Intraoperative findings were used to direct treatment. RESULTS: Endoluminal ultrasound detected 19 crossing vessels in 14 of 20 patients (70%), while CT detected 9 crossing vessels in 7 (35%). Endoluminal ultrasound identified a septum between the ureter and renal pelvis in 7 patients (35%) but CT demonstrated none. On the basis of imaging findings we selected 5 patients for pyeloplasty, and endoluminal ultrasound accurately predicted the absence or presence of crossing vessels in all 5. CT angiography was accurate in 3 patients. However, in 2 patients a total of 4 vessels were missed by CT. A total of 15 patients underwent endopyelotomy with no bleeding complications. The presence or absence of a septum on endoluminal ultrasound was confirmed in all patients. Imaging findings altered the treatment chosen in 4 patients and changed the direction of the incision at the ureteropelvic junction in another 4. Clinical and radiographic success was achieved in all 13 patients (100%) with adequate followup. CONCLUSIONS: Endoluminal ultrasound was more sensitive than CT angiography for identifying crossing vessels and septa. Treatment based on endoluminal ultrasound findings may decrease complications and improve the results of minimally invasive treatment for ureteropelvic junction obstruction.

Clearance of lower-pole stones following shock wave lithotripsy: effect of the infundibulopelvic angle.

OBJECTIVE: To assess the effect of anatomic factors, especially the angle of the lower-pole infundibulum, on stone clearance following shock wave lithotripsy (SWL) in order to determine selection criteria for percutaneous nephrolithotomy. METHODS: We retrospectively analyzed 116 patients with single lower-pole stones measuring 11-20 mm treated with SWL. Intravenous urograms were reviewed to measure the infundibulopelvic angle, the angle of the infundibulum to the vertical, and the anatomy of lower-pole calyces. RESULTS: The overall stone-free rate was 52%. Factors most closely associated with a stone-free status were obtuse infundibulopelvic angle, lack of calyceal distortion, and a large infundibular diameter. The infundibulopelvic angle was the only factor to attain significance in predicting stone-free status (p = 0.012). The size of the stone did not predict eventual stone-free status (p = 0.911), but larger stones were more likely to require intervention after SWL. CONCLUSION: For solitary lower-pole stones 11-20 mm in size, the angle of the lower-pole infundibulum as it relates to the pelvis plays a role in eventual stone clearance and should be taken into account before choosing a mode of treatment.

Endourological management of severely encrusted ureteral stents.

BACKGROUND: Encrustion of ureteral stents is a well-known phenomenon which can be treated easily if recognized promptly. Severe encrustation, however, which leads to renal impairment, presents a challenge in management. PATIENTS AND METHODS: Four patients with encrusted stents were referred to our institution for management. All had impaired function of the affected kidney. Each was managed by either retrograde ureteroscopy or a combination of percutaneous and ureteroscopic procedures. RESULTS: All four of the patients were rendered stone free following an average of 2.5 (range 1-3) procedures. Renal function improved in all patients postoperatively. CONCLUSIONS: Encrustation is a potentially serious complication of the use of ureteral stents, as it can lead to renal impairment. Timely endourologic intervention can result in recovery of renal function.

The effect of extracorporeal piezoelectric lithotripsy on the contractility of the human pelvicalyceal system.

OBJECTIVE: To assess the effect of extracorporeal piezoelectric lithotripsy (EPL) on the contractility of the human pelvicalyceal system. PATIENTS AND METHODS: Contractions of the pelvicalyceal system were measured in 12 patients (mean age 55 years) before and after EPL. Pelvicalyceal pressure was measured via a Cope nephrostomy tube which had remained in situ following stone debulking procedures days or weeks earlier. All patients were treated using a Wolf Piezolith 2300 lithotripter. RESULTS: The pelvicalyceal systems of two patients were acontractile before and after treatment. Immediately after treatment, contractions were completely abolished in eight of the remaining 10 systems, and reduced in frequency in the other two. All 10 systems regained contractions 24 h after treatment. CONCLUSION: Piezoelectric lithotripsy temporarily abolishes upper urinary tract motility.

Persistent stapedial artery preventing successful cochlear implantation: a case report.

A case of persistent stapedial artery preventing cochlear implantation is described and the literature relating to this congenital anomaly is reviewed. The computed tomographic features of the artery are illustrated, and it is recommended that preoperative computed tomography be specifically screened for this anomaly.

Renal aspergilloma due to Aspergillus flavus.

Renal aspergillomas have been reported only rarely. We report a case of Aspergillus flavus colonization of the renal pelvis and upper ureter of a patient with concomitant urinary schistosomiasis. The diagnosis was based on the demonstration of characteristic hyphal elements on direct microscopy and isolation of the fungus in culture. The patient was successfully treated with liposomal amphotericin B. This case emphasizes the importance of direct microscopic examination of urine specimens for prompt diagnosis of fungal infections of the urogenital system. Renal aspergilloma should be considered in the differential diagnosis of filling defects of the urinary tract, especially in patients who are immunocompromised.

Does further extracorporeal lithotripsy promote clearance of small residual fragments?

Small persistent fragments (less than or equal to 4 mm) following extracorporeal shock wave lithotripsy have been termed clinically insignificant residual fragments (CIRF), but their presence may be associated with an increased rate of development of recurrent symptomatic renal calculi. We have adopted a policy of further extracorporeal piezoelectric shock wave lithotripsy (EPL) for patients with CIRF in an attempt to promote complete clearance. A series of 22 patients with a mean initial stone burden of 16 mm (range 7-48) developed CIRF after a median of 2 EPL treatment sessions (range 1-9). CIRF were in the lower calices (n = 20), middle calices (n = 1) and upper calices (n = 1). These calices were normal (n = 6), slightly dilated (n = 9), moderately dilated (n = 2) or grossly dilated (n = 5). After 6 to 14 months, patients underwent a further session of EPL. One month later, 3 patients with normal calices showed a considerable reduction in CIRF, but all other patients showed no change. When CIRF form in normal calices a further session of EPL may promote clearance. However, when calices containing CIRF are significantly dilated, further EPL is of no value.

The impact of extracorporeal piezoelectric lithotripsy on the management of ureteric calculi: an audit.

The presentation and management of 153 patients with ureteric calculi requiring active treatment over a 12-month period were reviewed; 74% of patients had primary ureteric calculi and 26% had ureteric calculi composed of fragments resulting from extracorporeal piezoelectric shockwave lithotripsy (EPL) to renal calculi; 32 patients (21%) had more than 1 calculus or a steinstrasse. The primary procedures included were in situ EPL (n = 54), push-bang (44), retrograde ureteroscopy (40), Dormia basket extraction (6), push-pull (1), antegrade ureteroscopy (1) and combinations of these (7). The success of the primary procedure could not be predicted from stone size, site or duration in the ureter, but upper tract dilatation was significantly less (p less than 0.01) in the successful group. The overall success rate for complete stone extraction was 97%, but 54 patients (35%) required more than 1 procedure to achieve this. In situ EPL and push-bang, as either primary or secondary procedures, were successful in treating 79 patients (52%); 2 patients required ureterolithotomy (1.3%). The overall complication rate was 18%. Since EPL is only successful in treating approximately half of ureteric calculi, a range of other treatments should be available to maintain a low rate of open surgery.

Lithotripsy for calculi in caliceal diverticula?

There is continuing debate about the optimum management of patients with calculi in caliceal diverticula. Extracorporeal piezoelectric lithotripsy (EPL) has the advantage of being non-invasive, whereas endourological management can treat the underlying anatomical problem. A total of 20 patients with calculi in caliceal diverticula were treated with EPL. Twelve of 16 patients with symptoms (75%) were rendered symptom-free but only 5 (25%) became stone-free. This information should be of value in counselling patients before selecting the appropriate treatment.

Peripheral laser assisted angioplasty: results, complications and follow-up.

Detailed results including complications and ultimate outcome of 24 laser assisted angioplasties in 22 patients are presented. Despite the enthusiasm expressed in other published reports, we remain sceptical of the value of laser using a 1.5 mm 'hot-tip' probe for assisting angioplasty of peripheral occlusions. The tendency for this type of probe to damage the vessel wall and in so doing prohibit the use of subsequent balloon dilatation is a major problem. In this small series the long-term patency was not improved compared with conventional angioplasty. We have established the relative safety of this laser technique and further advances in probe design may lead to greater success in crossing long lesions. Long-term maintenance of patency in these diseased arteries will need further advances in technique and assessment preferably by a controlled trial.

Microsurgical reconstruction of the trachea in rats (an experimental study).

This study was carried out to evaluate the use of 'Zenoderm' (enzyme treated procine dermis) as a patch for the repair of tracheal defects in rats, with particular reference to its application in the treatment of some cases of tracheal stenosis. Fifty-three rats were included in the study. Using microsurgical techniques, a defect was created in the cervical trachea and repaired using a suitable patch of 'Zenoderm' (two groups with different sized defects). In a further group of rats, healing of the trachea was studied after excision of a segment and end to end anastomosis. A set number of rats were sacrificed after intervals of 14, 28, 91 and 182 days when the trachea was excised and evaluated. Healing of the tracheae following end to end anastomosis was satisfactory in all cases with no evidence of stenosis. The two groups of tracheae with Zenoderm patches showed progressive stenosis at the area of the repair but there was no evidence of respiratory obstruction or distress. The Zenoderm patch and the regenerating epithelium were both evaluated by light microscopy and scanning electromicroscopy. The Zenoderm patch showed gradual absorption and was replaced by host collagen. There was gradual regeneration of epithelium which showed slow maturation from flat non-ciliated epithelium to partially cuboidal and columnar epithelium with some cilia showing early differentiation to respiratory epithelium. In conclusion, this experimental study confirmed the biocompatibility of 'Zenoderm' in rats. It provided a suitable surface for regeneration of tracheal epithelium. Replacement of the patch by the host collagen is promising but requires further study to assess its rigidity and ability to withstand pressure changes in the trachea.

Epidural abscess complicating Swenson procedure: a case report and a review of the literature.

A case is reported in which an anastomotic leak following the Swenson procedure for Hirschsprung's disease was complicated by the development of a pelvic abscess that communicated freely with the epidural space. The child presented with signs and symptoms of an epidural abscess, but his myelogram was normal. The diagnosis was made by urografin enema. The child was treated by defunctioning colostomy and drainage of the pelvic abscess by enlarging the defect at the anastomosis site digitally. The epidural space drained freely to the pelvis and therefore laminectomy was not required. The possible etiology of such a communication is discussed.