Repeat Surgery After Ureteroscopic Laser Lithotripsy With Attempted Complete Extraction of Fragments: Long-term Follow-up.

OBJECTIVE: To explore repeat surgery as a primary outcome measure in long-term follow-up after ureteroscopic laser lithotripsy (URS) with attempted complete extraction of fragments. METHODS: Retrospective review of the medical records of consecutive patients undergoing URS performed by a single surgeon. Repeat surgery was defined as any return to the operating room for management of stone or complications. For our survival analysis, we used the Kaplan-Meier method. RESULTS: From April 2003 through May 2005 at our institution, URS was performed in 226 renal units in 216 patients. At a median follow-up of 4.1 years, 19 patients required repeat surgery. At 1 year, the cumulative repeat surgery rate (CRR) was 5.8% (95% confidence interval, 3.4%-9.8%), rising to 8.6% (5.6%-13.1%) at 5 years. CRR was strongly related to evidence of residual stone on postoperative computed tomography (P <.001). At 5 years, CRR was 3.5% (1.1%-10.3%) in patients with renal units with no detectable fragments, 8.2% (3.5%-18.6%) with fragments ≤4 mm, and 46.2% (24.0%-75.2%) with fragments >4 mm. The Cox proportional hazards ratio was 9.08 (2.11-38.00; P = .003) with fragments that were >2 mm; the ratio was 22.14 (5.15-95.14; P <.001) with fragments >4 mm. CONCLUSION: Repeat surgery after URS is proportional to the size of residual fragments. Repeat surgery is a discrete objective metric that is consistent with, but does not require, rigorous postoperative radiologic assessment.

Retreatment after percutaneous nephrolithotomy in the computed tomographic era: long-term follow-up.

OBJECTIVE: To examine the long-term retreatment rates and explore prognostic factors after percutaneous nephrolithotomy (PCNL) in the computed tomographic era. METHODS: Consecutive patients who underwent PCNL with a standardized technique attempting complete fragment detection and clearance by a single surgeon between September 2000 and June 2004 were identified. Through medical record, review details of procedures and outcomes were collected. RESULTS: A total of 166 renal units in 150 subjects were evaluated. Postoperative computed tomographic scans were conducted in 129 subjects. Median follow-up was 5.4 years (interquartile range, 4.2-6.2 years). Future ipsilateral procedures were performed in 23 renal units (14%) at a median of 2.9 years (interquartile range, 1.7-3.7 years). The cumulative retreatment rate at 7 years for noncalcium stones (24%) was not significantly higher than for calcium-based stones (14%; P = .07). Stone-free renal units had a lower cumulative retreatment rate (4%) than those with residual fragments <2 mm (33%) or ≥2 mm (30%; P = .001). When controlling for residual fragment size, renal units that were composed of uric acid or struvite had an expected hazard rate of retreatment 3.34 times larger than renal units composed of calcium oxalate/phosphate (P = .02) and renal units that were not stone free had an expected hazard rate 7.87 times larger than renal units that were stone free (P = .001). CONCLUSION: In this population of complex stone patients treated by PCNL, there appears to be no such thing as an "insignificant fragment." Efforts at initial stone clearance should be maximized.

High prevalence of gouty arthritis among the Hmong population in Minnesota.

OBJECTIVE: The prevalence of gout is on the rise worldwide, especially among newly industrialized populations. We evaluated the prevalence of gout in the recently established Hmong of Minneapolis/St. Paul (MSP) compared with that in non-Hmong populations. METHODS: The prevalence of self-reported gout in the Hmong population was estimated from 2 cross-sectional community surveys and compared with national data extrapolated from the Third National Health and Nutrition Examination Survey. The prevalence of physician-diagnosed gout in Hmong and non-Hmong MSP residents was separately estimated from the diagnosis codes of 11 MSP primary care clinics. RESULTS: The prevalence of self-reported gout among MSP Hmong was 2-fold higher than in the general US population (6.5% versus 2.9%; P < 0.001). Although women of both groups reported gout at a rate of 1.9%, Hmong men were significantly more likely than their non-Hmong counterparts to report gout (11.5% versus 4.1%; P < 0.001). Similar results were observed when investigating physician-diagnosed gout in MSP (2.8% Hmong versus 1.5% non-Hmong; P < 0.001). No difference was observed between the women of the 2 groups (0.8% versus 0.7%; P = 0.833), whereas Hmong men were more than twice as likely to be diagnosed with gout compared with their non-Hmong counterparts (6.1% versus 2.5%; P < 0.001). Among Hmong men, advancing age was associated with a considerably higher likelihood of being diagnosed with gout. CONCLUSION: A significant association is observed between Hmong ethnicity and gout, both self-reported and physician diagnosed. This unique population may provide an opportunity to further our understanding of the pathophysiology of gout.

Confident intraoperative decision making during percutaneous nephrolithotomy: does this patient need a second look?

OBJECTIVES: To evaluate intraoperative decision making regarding the necessity of second-look nephroscopy after percutaneous nephrolithotomy. METHODS: Percutaneous nephrolithotomy was performed cooperatively by a urologist and radiologist equipped with a high-resolution C-arm. Ultrasonic lithotripsy was performed followed by thorough flexible nephroscopy and fluoroscopy. At conclusion patients were prospectively classified as radiologically and/or endoscopically stone free. If confident that complete stone clearance had been atraumatically achieved, a ureteral stent was placed. If there was suspicion of trauma or residual calculi, a nephrostomy tube was inserted. Postoperative CT was performed and allowed fragment classification as stone free, less than 2 mm, 2 to 4 mm, or 4 mm or greater. RESULTS: Average stone dimensions were 640.2 +/- 412.5 mm2 in 39 consecutive renal units. Computed tomographic imaging demonstrated that 26 renal units (66.7%) were stone free after primary procedure, with 5 (12.8%), 5 (12.8%), and 3 (7.7%) having fragments less than 2 mm, 2 to 4 mm, and greater than 4 mm, respectively. Of the 34 renal units considered endoscopically and fluoroscopically stone free, postoperative CT demonstrated 9 with residual fragments, all less than 4 mm. Of the 5 renal units not considered radiologically and endoscopically stone free, 4 had fragments on CT. Nephrostomy tubes were avoided in 33 patients. This intraoperative decision was supported by negative predictive values of 100%, 88%, and 73% at postoperative CT fragment detection thresholds of 4 mm, 2 mm, and 0 mm, respectively. CONCLUSIONS: Rigorous fragment detection allows confident intraoperative decision making regarding the necessity of second-look nephroscopy.

Ureteroscopic laser lithotripsy for upper urinary tract calculi with active fragment extraction and computerized tomography followup.

PURPOSE: Management of fragments generated by ureteroscopic laser lithotripsy remains controversial. In this study we explored the impact of active fragment extraction after ureteroscopic laser lithotripsy on stone clearance. MATERIALS AND METHODS: A total of 69 patients with 3 or less upper urinary tract calculi (5 to 15 mm) demonstrated on preoperative CT were prospectively evaluated. Stones were translocated to a dependent upper pole calix where laser lithotripsy was performed. An attempt was made to clear all fragments using tipless stone baskets. One month after surgery stone clearance was evaluated exclusively with noncontrast spiral CT. RESULTS: In 58 patients undergoing surgery on protocol, average stone burden was 9.4 +/- 3.4 mm and was significantly smaller in 44 patients with stones in a solitary location (8.5 +/- 2.9 mm) than in 14 patients with stones in multiple locations (12.3 +/- 3.2 mm, p <0.001). Primary stone location was categorized as renal nonlower pole (in 16), renal lower pole (in 19) and proximal ureter (in 23). Average operative time (43.7 +/- 18.4 minutes) was unaffected by stone location or multiplicity after controlling for stone size (p >0.05). Stone clearance rates were not affected by stone location or multiplicity, with overall success rates of 54%, 84% and 95% at fragment thresholds of 0, 2 and 4 mm, respectively (p >0.05). CONCLUSIONS: Ureteroscopic laser lithotripsy with active fragment extraction was time efficient and highly effective. Sensitive postoperative imaging reveals the challenge of achieving a true stone-free state. We were unable to demonstrate an impact of stone location on stone-free rates.

Intraoperative fragment detection during percutaneous nephrolithotomy: evaluation of high magnification rotational fluoroscopy combined with aggressive nephroscopy.

PURPOSE: Percutaneous nephrolithotomy effectively treats large volume renal calculi but relies on postoperative imaging to judge success. We evaluated the effectiveness of maximizing intraoperative imaging through combined high resolution fluoroscopy and flexible nephroscopy. MATERIALS AND METHODS: Percutaneous nephrolithotomy was performed cooperatively with a radiologist in an interventional radiology suite equipped with a ceiling mounted, high resolution C-arm. Aggressive rigid and flexible nephroscopy was performed. At the conclusion patients were prospectively classified as radiologically and/or endoscopically stone-free. Postoperative noncontrast CT allowed fragment classification as stone-free, 2 mm or less, 2 to 4 mm and greater than 4 mm. RESULTS: The average stone dimension +/- SEM was 579 +/- 77 mm(2) in 25 consecutive renal units. CT demonstrated that 15 renal units (60%) were stone-free after the primary procedure, while 2 (8%), 5 (20%) and 3 (12%) had fragments 2 or less, 2 to 4 and greater than 4 mm, respectively. Of 21 renal units considered endoscopically and fluoroscopically stone-free postoperative CT demonstrated that 6 had residual fragments, of which all were less than 4 mm. All 4 renal units not considered radiologically and endoscopically stone-free had fragments on CT. Intraoperative fluoroscopy after nephroscopy demonstrated fragments in 36% of renal units, of which after further nephroscopy 78% were stone-free on CT. The sensitivity of intraoperative imaging with reference to the gold standard of postoperative CT was 40%, 38% and 100% at thresholds of 0, 2 and 4 mm, respectively. Specificity was 100%, 94% and 95%, respectively. CONCLUSIONS: Flexible nephroscopy combined with high magnification rotational fluoroscopy allows sensitive and specific intraoperative detection of residual fragments, enabling immediate removal or the planning of necessary second look nephroscopy.