Long-Term Results of Percutaneous Nephrolithotomy: Does Prophylactic Medical Stone Management Make a Difference?

A prospective study assessing feasibility of performing percutaneous nephrolithotomy in chronic kidney disease patients - What factors affect the outcome?

Objectives

To primarily evaluate the functional outcomes of PCNL for bilateral renal calculi/calculi in solitary functioning kidney with Chronic Kidney Disease(CKD). To identify factors affecting the renal replacement therapy following PCNL.

Materials and Methods

Patients with bilateral renal calculi/calculi in solitary kidney and CKD (eGFR<60/s.creatinine>2) and Good Performance Status [Eastern Cooperative Oncology Group (ECOG): 0–2] were included in the study.

Results

A total of 60 patients with CKD who had bilateral renal calculi/calculi in solitary functioning kidney underwent PCNL. At 6 months, eGFR improved or stabilized in 45 (75%) patients, while in 15 (25%) patients eGFR deteriorated. A total of 5 (14.28%) and 2 (25%) patients of CKD stage 4 and 5 respectively had improvement in eGFR as well as CKD stage. Fourteen (82.35%), 21 (60%), 3 (37.5%) patients of CKD stage 3, 4, 5 had improvement in eGFR but not significant enough to cause stage migration. Again 3 (17.65%) , 9 ( 40%) and 3 (37.5%) patients of CKD stage 3, 4, 5 had reduction in eGFR but not significant enough to cause stage migration. None of the patients had worsening of CKD stage. Preoperative CKD stage and eGFR were compared with measurements made at the final follow up visit (6 months).

Conclusion

Our results indicate that most patients of renal calculi with CKD show improvement or stabilization of renal function with aggressive stone removal. Improvement is more in patients who have mild to moderate CKD. Aggressive management of comorbidities, peri-operative UTI and complications may delay or avoid progression of CKD status in such patients.

Metabolic abnormalities in patients treated with percutaneous nephrolithotomy

Objectives:

To assess metabolic abnormalities in patients with percutaneous nephrolithotomy (PCNL) that could pose a risk for stone recurrence.

Materials and methods:

The data was collected retrospectively on all patients who had PCNL and metabolic studies, between January 2000 and September 2012.

Results:

There were 144 patients; median age and follow up were 49.5 (15– 4) years and 80.2 (16–180) months, respectively. Nearly half of the patients had staghorn calculus. Metabolic abnormalities (MAs) were found in 55 (38.2%). The 31 (21.5%) of these had multiple metabolic abnormalities (MMA) while 24 (16.6%) had a single metabolic abnormality (SMA). Uricosuria was found in 24 (16.6%), hyperoxaluria in 22 (15.3%), hyperphosphaturia in 18 (12.5%), hypercalciuria in 10 (7%), hypomagnesuria in 6 (4.2%), cystinuria in 5 (3.5%) and hypocitraturia in 5 (3.5%). Hyperuricaemia was present in 10 (7%), hypercalcaemia in 5 (3.5%), hyperphosphataemia in 7 (5%) and renal tubular acidosis in 1 (0.7%). In non-staghorn, MAs were found in 25 (35.2%) and 16 (64%) of these had MMA. In patients with staghorn, MAs were present in 30 (41%) patients. Half of the patients 15 (50%) in this group had MMA. A high proportion of the first time stone formers requiring surgical treatment had MAs and 57% of these had MMA. Stone analysis was available for 69 (48%) and 37 (53.6%) of these had mixed composition. The highest proportion of patients with uric acid stones had MA 89% followed by cystine stones 80%, matrix stones 50%, calcium oxalate 36.6%, carbonate apatite 36.4% and triple phosphate 33.3% .

Conclusion:

A high proportion of first time stone formers, staghorn and non-staghorn stone formers with PCNL had MA. These findings suggest that the treatment of metabolic abnormalities can play an important role in reducing the risk of stone recurrences and management may include referral to dedicated metabolic stone clinics.

Recent finding and new technologies in nephrolitiasis: a review of the recent literature

This review summarizes recent literature on advances regarding renal and ureteral calculi, with particular focus in areas of recent advances in the overall field of urolithiasis. Clinical management in everyday practice requires a complete understanding of the issues regarding metabolic evaluation and subgrouping of stone-forming patients, diagnostic procedures, effective treatment regime in acute stone colic, medical expulsive therapy, and active stone removal. In this review we focus on new perspectives in managing nephrolitihiasis and discuss recentadvances, including medical expulsive therapy, new technologies, and refinements of classical therapy such as shock wave lithotripsy, give a fundamental modification of nephrolithiasis management. Overall, this field appears to be the most promising, capable of new developments in ureterorenoscopy and percutaneous approaches. Further improvements are expected from robotic-assisted procedures, such as flexible robotics in ureterorenoscopy.

The impact of metabolic syndrome on long-term outcomes of percutaneous nephrolithotomy (PCNL)

Study Type--Prognosis (cohort) Level of Evidence 2b. What's known on the subject? and What does the study add? The presence of metabolic syndrome is associated with development of kidney stones and an increase in the stone-recurrence rate. However, studies reporting long-term results of percutaneous nephrolithotomy (PCNL) in metabolic syndrome are lacking. The present study showed that metabolic syndrome was associated with worsening renal function at long-term follow-up and the stone-recurrence rate recurrence after PCNL in patients with metabolic syndrome was 3.2-fold higher compared with the control group.

OBJECTIVE

• To investigate the impact of metabolic syndrome on long-term kidney function and stone recurrence rates after percutaneous nephrolithotomy (PCNL).

PATIENTS AND METHODS

• In all, 73 patients with metabolic syndrome who underwent stone analysis and had a minimum follow-up of 12 months after PCNL were reviewed. • In addition, 73 patients without any metabolic syndrome components who had undergone PCNL and were followed-up for at least 12 months were included in the study as the control group. • These control group patients were selected from 226 patients who were matched with the patients with metabolic syndrome using a 1 : 1 ratio. The matching parameters were age, gender and stone size.

RESULTS

• Stone analyses showed that calcium oxalate monohydrate (52.0%) and uric acid (21.9%) were most common among patients with metabolic syndrome, whereas calcium oxalate monohydrate (76.7%) was the most common stone type in the control group. • Stone recurrences occurred with a mean (sd, range) of 36.1 (21.3, 12-109) months follow-up in 26 patients (41.9%) and 12 patients (18.9%) in the metabolic syndrome and control groups, respectively (P = 0.003). • While estimated glomerular filtration rate was decreased from 87.8 to 66.6 mL/min/1.73 m(2) in the metabolic syndrome group, it changed from 96.4 to 91.2 mL/min/1.73 m(2) in control group at long-term follow-up.

CONCLUSIONS

• The most frequent stone type was calcium oxalate monohydrate in patients with or without metabolic syndrome. • In patients with metabolic syndrome who underwent PCNL, the stone recurrence rate was >40%. • Metabolic syndrome is associated with worsening renal function at long-term follow-up.

Factors affecting kidney function and stone recurrence rate after percutaneous nephrolithotomy for staghorn calculi: outcomes of a long-term followup

PURPOSE

There are few studies of the long-term outcome of percutaneous nephrolithotomy for staghorn calculi. We report the long-term outcome of percutaneous nephrolithotomy in patients with staghorn calculi.

MATERIAL AND METHODS

A total of 265 study patients (272 renal units) were followed in the long term for greater than 12 months. The estimated glomerular filtration rate was calculated using the 4-variable modification of diet in renal disease equation. Cases were staged for chronic kidney disease by National Kidney Foundation guidelines. The impact of patient and procedure related factors on renal function as well as stone recurrence was analyzed retrospectively.

RESULTS

At a mean ± SD followup of 37.3 ± 25.4 months the chronic kidney disease stage classification was maintained in 177 patients (66.8%) while the classification of 34 (12.8%) and 54 (20.4%) had improved and deteriorated, respectively. Multivariate analysis revealed that an immediate postoperative change in the estimated glomerular filtration rate was the only factor predicting a change in renal function in the long term. Stones recurred in 73 of the 234 kidneys (31.2%) that were stone free 3 months after percutaneous nephrolithotomy. Stone size increased in 24 of the 38 kidneys (63.2%) with residual stones after intervention. Recurrent urinary infections during followup and diabetes were associated with stone recurrence and residual stone enlargement.

CONCLUSIONS

In almost 80% of patients with staghorn stones renal function was improved or maintained after percutaneous nephrolithotomy, as documented during long-term followup. Stones recurred in a third of the patients with staghorn calculi.