In vivo assessment of free radical activity during shock wave lithotripsy using a microdialysis system: the renoprotective action of allopurinol.

PURPOSE: Shock wave lithotripsy is believed to cause renal damage directly through cellular injury from high energy shock waves and indirectly through vascular injury and resultant ischemia, which gives rise to oxygen free radical compounds. The transient and volatile nature of free radicals and derived products makes their detection difficult. Moreover, certain medications may provide a protective effect against shock wave lithotripsy induced renal parenchymal injury. We introduced an innovative microdialysis system for in vivo sampling of interstitial fluids that can be analyzed for free radical mediated lipid peroxidation products after shock wave lithotripsy treatment in the swine model. In addition, this system was used to test the antioxidant or renoprotective action of allopurinol. MATERIALS AND METHODS: Ten juvenile swine were assigned to a nonmedicated control group that underwent shock wave lithotripsy or to a group that was premedicated with allopurinol before shock wave lithotripsy. Each group of animals underwent shock wave lithotripsy to the lower pole of the right kidney and received a total of 10,000 shock waves. Dialysate fluid was collected at 1,000-shock wave increments via probes surgically implanted into the lower pole of the right and left kidneys before lithotripsy. Samples were immediately preserved in liquid nitrogen and subsequently analyzed for the presence and concentration of conjugated diene levels, a measure of lipid peroxidation. Five additional juvenile swine were assigned to a sham treated group that did not undergo shock wave lithotripsy. Dialysate fluid was collected from the lower pole of the right and left kidneys to establish baseline or pre-lithotripsy levels of conjugated dienes. RESULTS: After shock wave lithotripsy conjugated diene levels increased almost 100-fold over that in the right kidneys of the nonmedicated control group. The difference was statistically significant compared to levels in the contralateral untreated kidneys (p <0.01). Right kidneys in the group premedicated with allopurinol did not demonstrate an increase in conjugated diene levels during shock wave lithotripsy. CONCLUSIONS: The results of this study confirm shock wave lithotripsy induced free radical activity as well the antioxidant and protective nature of allopurinol. The newly described microdialysis system enables real-time sampling of interstitial fluids during shock wave lithotripsy. It represents a unique method for assessing free radical formation and evaluating the protective effects of additional antioxidant medications.     

LOWER POLE I: A PROSPECTIVE RANDOMIZED TRIAL OF EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY AND PERCUTANEOUS NEPHROSTOLITHOTOMY FOR LOWER POLE NEPHROLITHIASIS—INITIAL RESULTS

PURPOSE: The efficacy of shock wave lithotripsy and percutaneous stone removal for the treatment of symptomatic lower pole renal calculi was determined. MATERIALS AND METHODS: A prospective randomized, multicenter clinical trial was performed comparing shock wave lithotripsy and percutaneous stone removal for symptomatic lower pole only renal calculi 30 mm. or less. RESULTS: Of 128 patients enrolled in the study 60 with a mean stone size of 14.43 mm. were randomized to percutaneous stone removal (58 treated, 2 awaiting treatment) and 68 with a mean stone size of 14.03 mm. were randomized to shock wave lithotripsy (64 treated, 4 awaiting treatment). Followup at 3 months was available for 88% of treated patients. The 3-month postoperative stone-free rates overall were 95% for percutaneous removal versus 37% lithotripsy (p <0.001). Shock wave lithotripsy results varied inversely with stone burden while percutaneous stone-free rates were independent of stone burden. Stone clearance from the lower pole following shock wave lithotripsy was particularly problematic for calculi greater than 10 mm. in diameter with only 7 of 33 (21%) patients becoming stone-free. Re-treatment was necessary in 10 (16%) lithotripsy and 5 (9%) percutaneous cases. There were 9 treatment failures in the lithotripsy group and none in the percutaneous group. Ancillary treatment was necessary in 13% of lithotripsy and 2% percutaneous cases. Morbidity was low overall and did not differ significantly between the groups (percutaneous stone removal 22%, shock wave lithotripsy 11%, p =0.087). In the shock wave lithotripsy group there was no difference in lower pole anatomical measurements between kidneys in which complete stone clearance did or did not occur. CONCLUSIONS: Stone clearance from the lower pole following shock wave lithotripsy is poor, especially for stones greater than 10 mm. in diameter. Calculi greater than 10 mm. in diameter are better managed initially with percutaneous removal due to its high degree of efficacy and acceptably low morbidity.     

Can Phyllanthus niruri affect the efficacy of extracorporeal shock wave lithotripsy for renal stones? A randomized, prospective, long-term study

PURPOSE: Phyllanthus niruri is a plant used in Brazilian folk medicine for the treatment of urolithiasis. We assessed the efficacy of P. niruri after extracorporeal shock wave lithotripsy for renal stones. MATERIALS AND METHODS: We prospectively evaluated 150 patients with renal stones that were as large as 25 mm and composed of calcium oxalate. All patients received 1 to 3 extracorporeal shock wave lithotripsy sessions by Dornier Lithotriptor S. After treatment 78 of 150 patients (52%) underwent therapy with Uriston, a P. niruri extract (2 gm daily) for at least 3 months (group 1). Otherwise 72 of 150 patients (48%) were used as a control group (group 2). No significant difference in stone size between the 2 groups was found. Stone clearance was assessed after 30, 60, 90 and 180 days by abdominal x-ray and ultrasound scan. RESULTS: Stone-free rate (stone-free defined as the absence of any stone or residual fragments less than 3 mm) was 93.5% in group 1 and 83.3% in group 2 (p = 0.48) at the end point of the followup (180 days). For lower caliceal stones (56 patients) the stone-free rate was 93.7% in the treatment group and 70.8% in the control group (p = 0.01). Re-treatment need for group 1 was 39.7% and for group 2 it was 43.3% (p = 0.2). No side effects were recorded with extracorporeal shock wave lithotripsy or P. niruri therapy. CONCLUSIONS: Regular self-administration of P. niruri after extracorporeal shock wave lithotripsy for renal stones results in an increased stone-free rate that appears statistically significant for lower caliceal location. Its efficacy and the absolute lack of side effects make this therapy suitable to improve overall outcomes after extracorporeal shock wave lithotripsy for lower pole stones.     

Is lower pole caliceal anatomy predictive of extracorporeal shock wave lithotripsy success for primary lower pole kidney stones?

PURPOSE: The management of lower pole kidney stones is controversial. We examined whether lower pole caliceal anatomy could predict the success of extracorporeal shock wave lithotripsy of primary lower pole kidney stones 20 mm. or less. MATERIALS AND METHODS: From December 1997 to June 2001, 246 adults with a single, 20 mm. or less radiopaque lower pole renal stone were treated with the Doli 50 lithotriptor (Dornier Medical Systems, Marietta, Georgia) while under general anesthesia. Of the 246 patients 190 (77%) had excretory urography available for review. Lower pole infundibular length and width, lower pole infundibulopelvic angle and caliceal-pelvic height were measurable on 161 (85%), 129 (68%), 128 (67%) and 163 (86%) excretory urograms, respectively. Extracorporeal shock wave lithotripsy was considered a failure if residual stone fragments remained after 1 month, or an auxiliary procedure or re-treatment was required.RESULTS The overall stone-free rate was 78% (32 of 41) for stones 5 mm. or less, 73% (98 of 135) for stones 6 to 10 mm., 43% (22 of 51) for stones 11 to 15 mm. and 30% (7 of 19) for stones 16 to 20 mm. in maximum linear dimension. The stone-free rates grouped according to stone surface area were 76% (48 of 63 stones) for stone surface area 25 mm.2 or less, 69% (97 of 141) for 26 to 100 mm.2 and 33% (14 of 42) for 101 to 400 mm.2. Caliceal anatomy was not predictive of success even with stones grouped as 10 or less or 11 to 20 mm. Grouping patients with favorable (lower pole infundibulopelvic angle 70 degrees or greater, lower pole infundibular length 30 mm. or less and lower pole infundibular width greater than 5 mm.) versus unfavorable (70 degrees or less, greater than 30 mm. and 5 mm. or less, respectively) anatomy was also not predictive of success. CONCLUSIONS: On the Doli 50 machine stone size rather than caliceal anatomy is predictive of treatment outcome. Initial treatment failures with this machine should be managed by alternative endoscopic procedures if necessary rather than by repeat shock wave lithotripsy.     

Prediction of lower pole stone clearance after shock wave lithotripsy using an artificial neural network

PURPOSE: We performed this study as a comprehensive evaluation of variables reported to affect lower pole stone clearance after shock wave lithotripsy using artificial neural network analysis. MATERIALS AND METHODS: The radiographic images and treatment records of 680 patients with lower pole renal calculi treated with primary shock wave lithotripsy using the Wolf Piezolith 2500 (Wolf, Knittlingen, Germany) lithotriptor were retrospectively evaluated by applying artificial neural network analysis. Successful stone clearance was defined as absent fragments of any size detected on plain x-ray with tomography and/or excretory pyelography performed 6 months after treatment. Prognostic variables included patient characteristics, laboratory values, stone characteristics and the spatial anatomy of the lower pole, as defined by infundibular length, diameter, caliceal pelvic height, 2 measurements of the lower infundibulopelvic and infundibuloureteropelvic angles as well as the pattern of dynamic urinary transport. RESULTS: Artificial neural network analysis had 92% accuracy for correctly predicting lower pole stone clearance. The pattern of dynamic urinary transport represented the most influential predictor of stone clearance, followed by a measure of the infundibuloureteropelvic angle, body mass index, caliceal pelvic height and stone size. Anatomical measurements of lower pole anatomy and classification of the type of urinary transport were well reproducible with low intra-observer and interobserver variability (correlation coefficient alpha >0.8). CONCLUSIONS: In a comprehensive analysis of variables reported to influence lower pole stone clearance artificial neural network analysis predicted stone clearance with a high degree of accuracy. The relative importance of dynamic urinary transport in lower pole stones and the usefulness of artificial neural network analysis to predict shock wave lithotripsy outcomes in individuals must be confirmed in a prospective trial.     

Localization of renal oxidative stress and inflammatory response after lithotripsy

OBJECTIVE

To determine if the acute renal oxidative stress and inflammation after extracorporeal shock wave lithotripsy (ESWL), thought to be mediated by ischaemia, is most severe in the portion of the kidney within the focal zone of the lithotripter, and if these effects result primarily from ischaemic injury.

MATERIALS AND METHODS

Pigs (7–8‐weeks old) received either 2000 shock waves at 24 kV to the lower‐pole calyx of one kidney or unilateral renal ischaemia for 1 h. A third group (sham) received no treatment. Timed urine and blood samples were taken for analysis of lipid peroxidation and the inflammatory cytokines, tumour necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6). At 4 h after treatment, kidneys were removed and samples of cortex and medulla were frozen for analysis of cytokines and heme oxygenase‐1 (HO‐1).

RESULTS

ESWL did not affect urinary excretion of malondialdehyde, but did elicit an eight‐fold induction of HO‐1 in the portion of the renal medulla within the focal zone of the lithotripter (F2), while remaining unchanged elsewhere in the treated kidney. There was no induction of HO‐1 in renal tissue after ischaemia‐reperfusion. Urinary excretion of TNF‐α increased from the lithotripsy‐treated kidney by 1 h after treatment, but was unaffected by ischaemia‐reperfusion. As with the HO‐1 response after lithotripsy, IL‐6 increased only in the renal medulla at F2. By contrast, ischaemia‐reperfusion increased IL‐6 in all samples from the treated kidney.

CONCLUSION

These findings show that the acute oxidative stress and inflammatory responses to ESWL are localized to the renal medulla at F2. Furthermore, the differing patterns of markers of injury for ESWL and ischaemia‐reperfusion suggest that ischaemia is not the principal cause of the injury response after ESWL.     

The effect of discharge voltage on renal injury and impairment caused by lithotripsy in the pig

The present study was designed to determine the effects of shock wave voltage (kV) on lesion size and renal function induced by shock wave lithotripsy (SWL) in the 6- to 8-wk-old pig. Each SWL-treated pig received 2000 shock waves at 12, 18, or 24 kV to the lower pole calyx of one kidney. A group of sham SWL pigs served as time controls. Bilateral GFR, renal plasma flow (RPF), and para-aminohippurate (PAH) extraction were measured 1 h before and 1 and 4 h after SWL in all treated and sham animals. The kidneys were removed at the end of each experiment for morphometric analysis. The SWL-induced lesion increased significantly in size as shock wave energy was increased from 12 to 24 kV. PAH extraction, a measure of tubular function, was not significantly affected at 12 kV, was transiently reduced at 18 kV, and was reduced for the duration of the experiment at 24 kV. GFR and RPF, however, were significantly and similarly reduced at the 1 h post-SWL period at all three kilovolt levels. At the 4-h post-SWL period, both GFR and RPF had returned to baseline levels. Lesion size and tubular injury were correlated with changes in kilovoltage, while changes in renal hemodynamics were already maximal at the lowest discharge voltage. These findings suggest that renal microvessels are highly sensitive to shock waves and that frank injury to tubules and vessels may be more closely related to discharge energy than is renal blood flow.     

Extracorporeal shock wave lithotripsy for patients with calcified ipsilateral renal arterial or abdominal aortic aneurysms.

A total of 4 patients with renal or upper ureteral calculi associated with ipsilateral calcified renal arterial or abdominal aortic aneurysms underwent extracorporeal shock wave lithotripsy. One patient with a renal artery aneurysm had a solitary kidney. Linear distance from the calcified aneurysm to the stone, calculated by computerized and plain tomography, ranged between 4.6 and 6.5 cm. (mean 5.3). Treatment was accomplished on an unmodified Dornier HM3 lithotriptor using 900 to 2,400 shock waves (mean 1,575) at 18 kv. There were no complications of treatment and all 4 patients were discharged from the hospital within 24 hours, at which time radiographic examination revealed excellent stone comminution without change in the calcified aneurysm. With followup as long as 30 months, no adverse effects of therapy have become evident. We conclude that the presence of an ipsilateral calcified aneurysm may not necessarily preclude treatment of renal or upper ureteral calculi with extracorporeal shock wave lithotripsy, although further studies are required to help define the potential limits of such therapy in this setting.     

孤立肾上尿路结石的ESWL治疗

目的:总结孤立肾并发上尿路结石ESWL治疗的经验。方法:电压比非孤立肾者略低,JT-Ⅲ型机8～12kV,HB-V型机4～8kV;放电次数比非孤立肾者略少,Ⅲ型机1500～2000次,V型机3000～3500次;同时减慢冲击频率;间隔时间二周以上比非孤立肾者稍长。直径大于2cm或多发结石且颗粒较大者,先行经皮肾镜取石后残石再行ESWL,多发或直径大于1.5cm的结石留置双J管后再ESWL,梗阻引起急性肾功能减退者急诊ESWL或先行肾造瘘或逆行插管引流积水,肾功能基本恢复后再ESWL。结果:22例独肾结石除7例多发外,15例一次成功,6例输尿管结石除1例再碎石外,5例一次成功。结论:ESWL治疗孤立肾上尿路结石损伤小且疗效好。     

Effect of shock wave number on renal oxidative stress and inflammation

What’s known on the subject? and What does the study add? Oxidative stress and inflammation are tissue‐ and cell‐level components of shock wave lithotripsy (SWL)‐induced acute renal injury, which we recently showed to be localized principally to the medulla within the focal zone of the lithotripter. This study reports that the magnitude of the oxidative stress and inflammation observed in the medulla after SWL is dependent on the number of shock waves delivered to the kidney, indicating that this is a sensitive measure of renal injury caused by shock waves. OBJECTIVE To determine if the magnitude of the acute injury response to shock‐wave lithotripsy (SWL) depends on the number of SWs delivered to the kidney, as SWL causes acute renal oxidative stress and inflammation which are most severe in the portion of the kidney within the focal zone of the lithotripter. MATERIALS AND METHODS Pigs (7–8 weeks old) received 500, 1000 or 2000 SWs at 24 kV from a lithotripter to the lower pole calyx of one kidney. At 4 h after treatment the kidneys were removed, and samples of cortex and medulla were frozen for analysis of the cytokine, interleukin‐6, and for the stress response protein, heme oxygenase‐1 (HO‐1). Urine samples taken before and after treatment were analysed for the inflammatory cytokine, tumour necrosis factor‐α. For comparison, we included previously published cytokine data from pigs exposed to sham treatment. RESULTS Treatment with either 1000 or 2000 SWs caused a significant induction of HO‐1 in the renal medulla within the focal zone of the lithotripter (F2, 1000 SWs, P < 0.05; 2000 SWs, P < 0.001). Interleukin‐6 was also significantly elevated in the renal medulla of the pigs that received either 1000 or 2000 SWs (P < 0.05 and <0.001, respectively). Linear dose–response modelling showed a significant correlation between the HO‐1 and interleukin‐6 responses with SW dose (P < 0.001). Urinary excretion of tumour necrosis factor‐α from the lithotripsy‐treated kidney increased only for pigs that received 2000 SWs (P < 0.05). CONCLUSION The magnitude of renal oxidative stress and inflammatory response in the medulla increased with the number of SWs. However, it is not known if the HO‐1 response is beneficial or deleterious; determining that will inform us whether SWL‐induced renal injury can be assessed by quantifying markers of oxidative stress and inflammation.     

Management options for lower pole renal calculi

PURPOSE OF REVIEW: The optimal treatment of lower pole renal calculi is controversial. Shock wave lithotripsy, ureteroscopy and percutaneous nephrostolithotomy all constitute viable therapeutic options in select patients. RECENT FINDINGS: Lower pole stones smaller than 1 cm in diameter can be managed with observation, shock wave lithotripsy or ureteroscopy. Patients electing expectant management should be counseled regarding the potential for stone-related symptom progression and need for future intervention. Shock wave lithotripsy and ureteroscopy have similar stone-free rates, although shock wave lithotripsy may be preferable due to more favorable secondary outcomes. Lower pole stones 1-2 cm in diameter are best managed with percutaneous nephrostolithotomy, although ureteroscopy is an option in select patients, particularly those not considered candidates for percutaneous nephrostolithotomy. Finally, patients with lower pole stones larger than 2 cm are best served with percutaneous nephrostolithotomy, as the morbidity in experienced hands is low and stone-free rates are unequivocally higher than those of other treatment modalities. SUMMARY: A variety of factors, including patient body habitus, local renal anatomy, cost and patient preference, must be taken into consideration when determining the optimal treatment modality for lower pole renal calculi.     

Extracorporeal Shock Wave Lithotripsy in L-shaped Kidneys: Report of Two Cases

The L-shaped or tandem kidney is a type of crossed ectopia with fusion in which the crossed kidney assumes a transverse position during its attachment to the inferior pole of the other kidney. Calculus formation is a well-known sequel of congenital abnormalities of the urinary tract and we like to present two patients harbouring calculi in L-shaped kidneys treated by extracorporeal shock wave lithotripsy (ESWL). The first patient had a calculus in renal pelvis of the transverse kidney. The second case had multiple calculi in renal pelvis and calices of the vertically positioned kidney. After three sessions, first patient was stone free, whereas no fragmentation in the second case. As a conclusion, ESWL might be an option for L-shaped kidneys.     

Impact of lower pole renal anatomy on stone clearance after shock wave lithotripsy: fact or fiction?

PURPOSE: We determined whether there is a significant relationship between the spatial anatomy of the lower pole on preoperative excretory urography and stone fragment clearance after shock wave lithotripsy. MATERIALS AND METHODS: The anatomical factors affecting lower pole stone clearance after shock wave lithotripsy were evaluated retrospectively in 108 patients. Stone-free status was assessed by renal computerized tomography with or without renal ultrasound. The stone-free rate at 3 months was correlated with lower pole infundibular length and width in mm. as well as with the lower pole infundibulopelvic angle in degrees. The statistical significance of each lower pole anatomical factor as well as other stone, renal and treatment factors were correlated with the stone-free rate using the Mann-Whitney and chi-square tests. RESULTS: Three months after shock wave lithotripsy 79 patients (73.1%) were free of stones. Mean lower infundibular length plus or minus standard deviation was 20.9 +/- 6.56 mm., mean infundibular width was 5.65 +/- 2.34 mm. and the mean lower pole infundibulopelvic angle was 48.33 +/- 14.84 degrees. In 49 (45.4%) and 59 (54.6%) patients infundibular length was greater than 3 cm. and 3 cm. or less, respectively. Infundibular width was greater than 5 mm. and 5 mm. or less in 45 (41.7%) and 63 (58.3%) patients, respectively. No obtuse infundibulopelvic angles were noted. None of the 3 lower pole anatomical factors had any significant impact on the stone-free rate at 3 months. Renal morphology was the only factor significantly affecting the stone-free rate since stone clearance was significantly less in pyelonephritic kidneys (p = 0.0009). CONCLUSIONS: Differences in the intrarenal anatomy of the lower pole have no significant impact on stone clearance after shock wave lithotripsy. Further examination of the lower pole renal anatomy with a search for other contributing factors is still warranted.     

Atrophy of kidney following extra corporeal shock wave lithotripsy of renal calculus in a paraplegic patient with marked spinal curvature

OBJECTIVES: To discuss a rare complication of extra corporeal shock wave lithotripsy (ESWL) of renal calculus in a paraplegic patient, who had marked curvature of thoracic and lumbar spine. DESIGN: A case report of a paraplegic patient, who developed renal atrophy and hypertension after undergoing ESWL of staghorn calculus. SETTING: Regional Spinal Injuries Centre, Southport and Mersey Regional Lithotripsy Unit, Royal Liverpool University Hospital, Liverpool, UK. PARTICIPANT: A 28-year-old male with spina bifida, paraplegia at L-1 level and considerable curvature of spine and tilting of pelvis. METHOD: ESWL was carried out in three sessions by delivering 1934, 1876, and 2025 shock waves respectively. Localisation of the staghorn calculus was difficult because of spinal curvature and pelvic tilt. RESULTS: A follow-up IVU, performed 3 months after last ESWL treatment, revealed no residual stone in the left kidney, apart from a little low-density calcification in the renal parenchyma adjacent to the lower pole calyx. There were no calculi in the left ureter. The left kidney had become small, though still functioning. MAG-3 isotope renogram showed the left kidney to be markedly atrophic. Relative renal function: right kidney, 94%; and left kidney, 6%. He developed hypertension and a laparoscopic left nephrectomy was performed at another hospital. CONCLUSION: Difficulty in localisation of renal calculi for ESWL must be anticipated in spinal bifida and spinal cord injury patients, who have significant spinal curvature. Because of problems in the positioning of a patient with marked curvature of spine and pelvic tilt, and consequent difficulties in accurate localisation of renal calculi for lithotripsy, these patients may be at increased risk of developing renal parenchymal and vascular damage following ESWL.     

Renal stone-associated squamous cell carcinoma and pyelo-colo-duodenal fistula

A 74-year-old man with hypertension presented with foamy urine and intermittent right upper quadrant abdominal pain. He had undergone 2 sessions of percutaneous nephrolithotripsy for right renal stones and shock wave lithotripsy 6 months before for residual stones. Abdominal computed tomography showed stones in an irregularly shaped right kidney and abscess formation that extended through the colon and was communicating with the duodenum.     

Flexible ureteroscopy in conjunction with in situ lithotripsy for lower pole calculi

Objectives. To demonstrate the efficacy and safety of ureteroscopy as a compromise in treating small and intermediate-size lower pole calculi. The optimal management of lower pole calculi remains controversial. Shock wave lithotripsy is associated with minimal morbidity but with suboptimal stone clearance rates. Conversely, percutaneous nephrostolithotomy has greater morbidity but stone-free rates greater than 90% regardless of size.Methods. Seventy-two patients underwent ureteroscopy for lower pole calculi 2 cm or less (mean 8.7 mm) during a 3-year period. To minimize confounding, 11 patients with additional calculi at other ipsilateral renal sites and 1 patient with large (2.4 cm each) bilateral calculi were excluded. Two patients with bilateral lower pole calculi and four who required a second procedure were included in the analysis. Thus, the final cohort consisted of 60 patients who underwent 66 procedures.Results. Of patients with follow-up longer than 1 month, 79% were stone free after a single procedure, and this improved to 88% after a second procedure in 4 patients. All 7 patients with follow-up less than 1 month had a reduction in stone burden after successful fragmentation. Overall, 8 patients required an auxiliary procedure. No intraoperative complications, and 7 (11%) postoperative complications occurred.Conclusions. Ureteroscopy for lower pole calculi is associated with minimal morbidity and stone-free rates comparable to shock wave lithotripsy for smaller stones. The greatest utility of ureteroscopy is in the management of intermediate-size calculi, for which it has substantially higher stone-free rates and lower repeated treatment rates than does shock wave lithotripsy.     

Impact of anatomical pielocaliceal topography in the treatment of renal lower calyces stones with extracorporeal shock wave lithotripsy

AIM: There is wide consensus that the lowest success rate of extracorporeal shock wave lithotripsy (ESWL) is in the complete clearance of renal stones located in the lower calyces. We assess the effectiveness of extracorporeal shock wave lithotripsy monotherapy for lower pole renal calculi to determine the relationship between the spatial anatomy of lower pole and the outcome of ESWL. METHODS: We evaluated 107 patients who were treated for solitary lower pole renal stones less than 20 mm in diameter with ESWL. The spatial anatomy of the lower pole, as defined by the lower infundibulopelvic angle, infundibular length and infundibular width, was measured by preoperative intravenous pyelography, while the stone location and size were determined by using abdominal plain X-ray. All patients were followed up at 1 and 3 months with abdominal plain X-ray and ultrasonography. RESULTS: Only 62 patients (58%) became stone free, while 45 (42%) retained residual fragments. A small lower infundibulopelvic angle, a long infundibular length and a tight infundibular width are unfavorable for stone clearance after ESWL. CONCLUSIONS: ESWL is the treatment of choice for most renal and ureteral stones. However, stone clearance from the lower pole following ESWL is poor and significantly affected by the inferior pole collecting system anatomy. Therefore, we believe it is important to evaluate these anatomical factors when deciding on the best treatment for lower pole renal calculi.     

体外冲击波碎石术患者肾血流动力学的评估

目的探讨体外冲击波碎石术(ESWL)对肾血流指数的影响。方法选取2016年8月至2018年4月在我院行ESWL的48名肾结石患者。使用超声诊断仪进行肾内血流评估,包括同侧肾和对侧肾,计算阻力指数(RI),脉动指数(PI)和加速时间(AT)等参数。结果 ESWL治疗后同侧肾脏以及对侧肾脏的RI指数明显增高(P0.001)。ESWL后96小时RI值降低至接近治疗前。ESWL后同侧肾脏以及对侧肾脏的PI参数也显著增加(P0.001),96小时后下降至与术前相近。显示RI与PI指数的增高与患者年龄之间呈正相关(r=0.562,P0.05)。结论肾结石的体外冲击波碎石(ESWL)会导致同侧和对侧肾脏的肾灌注暂时受损,患者年龄可能是决定RI和PI参数值的主要因素。     

Direct percutaneous approach to the upper pole of the kidney: MRI anatomy with assessment of the visceral risk

PURPOSE: In an attempt to determine the visceral risk secondary to a direct percutaneous puncture of the upper renal calix, the anatomic relations of the upper pole of the kidney were studied by magnetic resonance imaging. METHODS: Examination was performed on 25 normal volunteers placed successively in the right and left prone oblique position. The kidney axis and minimal distances from the cutaneous plane at the level of the upper and lower poles were measured. Axial and tangential simulated percutaneous approaches to the upper renal calix were compared in term of risk of damage to the pulmonary, splenic, and hepatic parenchyma. RESULTS: The transversal anteversion angle was statistically comparable for right and left kidneys, but the sagittal anteversion angle was significantly higher for right kidneys (p = 0.05). The minimal distance from the cutaneous plane was statistically comparable for the upper and lower poles. The lower pole was significantly deeper for left than right kidneys (p = 0.01). The visceral risk was statistically comparable for left and right kidneys and was significantly higher in case of an approach in the axis of the upper renal calix or through the 10th intercostal space compared to a puncture via the l1th space (p = 0.0001). CONCLUSION: A percutaneous puncture of the upper pole of the kidney above the 11th rib increases the risk of visceral damage. Preoperative evaluation, with the aid of CT scan or MRI, of the risk of pulmonary, splenic, or hepatic injury could be carried out in these cases.     

Is the gravity effect of radiographic anatomic features enough to justify stone clearance or fragments retention following extracorporeal shock wave lithotripsy (SWL)

We determined whether the gravity effect of radiographic anatomic features on the preoperative urography (IVP) are enough to predict fragments clearance after shock wave lithotripsy (SWL). A Total of 282 patients with mean age 45.8 ± 13.2 years (189 male, 93 female), who underwent SWL due to renal calculi between October 2005 and August 2009 were enrolled. The mean calculi load was 155.72 ± 127.66 mm2. The patients were stratified into three groups: patients with pelvis calculi (group 1); patients with upper or middle pole calculi (group 2) and patients with lower pole calculi (group 3). Three angles on the pretreatment IVP were measured: the inner angle between the axis of the lower pole infundibular and ureteropelvic axis (angle I); the inner angle between the lower pole infundibular axis and main axis of pelvis-ureteropelvic (UP) junction point (angle II) and the inner angle between the lower pole infundibular axis and perpendicular line (angle III). Multivariate analysis was used to define the significant predictors of stone clearance. The overall success rate was 85.81%. All angles, sessions number, shock waves number and stone burden were significant predictors of success in patients in group 1. However, in group 2 only angle II and in group 3 angles I and II had significant effect on stone clearance. Radiographic anatomic features have significant role in determining the stone-free rate following satisfactory fragmentation of renal stones with SWL. The measurement of infundibulopelvic angle in different manner helps to predict the stone-free status in patients with renal calculi located not only in lower pole, but also in renal pelvis and upper or middle pole. Gravity effect is not enough to justify the significant influence of the radiographic anatomic features on the stone clearance and fragments retention after SWL.