Outcomes of contemporary percutaneous nephrostolithotomy in morbidly obese patients

Ultra-mini-percutaneous nephrolithotomy in flank-free modified supine position versus prone position in treatment of pediatric renal pelvic and lower calyceal stones

OBJECTIVES

To report the safety and efficacy of ultra-mini-percutaneous nephrolithotomy (UMPCNL) in flank free modified supine (FFMS) and prone positions in management of pediatric renal calculi.

PATIENTS & METHODS

This prospective randomized study included 55 pediatric patients with symptomatic renal stones and suitable for ultra-mini-percutaneous nephrolithotomy. They were randomized into two groups. Group A included 28 patients who were treated by UMPCNL in FFMS position (with a pad below the ipsilateral shoulder and buttocks, putting ipsilateral upper limb over the chest, and crossing the extended ipsilateral lower limb over the flexed contralateral one) and Group B included 27 patients treated by UMPCNL in the prone position. In both groups dilatation was done to 13 French sheath allowing the introduction of 6/7.5 French semi-rigid ureteroscope and fragmentation of stones by Ho:YAG laser with a 550-μm fiber laser lithotripter.

RESULTS

The operation time in FFMS position UMPCNL group was significantly shorter than prone position UMPCNL group (84.3±9.87 vs. 99.3±8.75) minutes with p=0.022. There was no significant difference between both groups in terms of stone free rate (89.3% vs. 88.9%), overall complication rate (including transient fever) (21.4% vs. 18.5%), post-operative pain (VAS score) (3.4±0.8 vs. 3.3±0.9), or hospital stay (3.53±0.8 vs. 4.1±1.1) days.

CONCLUSION

Both ultra-mini-percutaneous nephrolithotomy in FFMs and prone positions are feasible, safe and effective in treatment of pediatric renal stones with relatively shorter operative time in FFMS position.

Outcomes of Flank-Free Modified Supine Percutaneous Nephrolithotomy Based on BMI

OBJECTIVE

To evaluate the impact of body mass index (BMI) on the outcomes of percutaneous nephrolithotomy (PCNL) in the flank-free modified supine position.

PATIENTS AND METHODS

A prospective study was carried out in the urology department during the period from May 2015 to October 2019 on 464 patients admitted for PCNL. The patients were divided into 4 matched groups according to their BMI: group A, normal weight with 18.5 ≤ BMI <25 kg/m2; group B, overweight with 25 ≤ BMI <30 kg/m2; group C, obese with 30 ≤ BMI <40 kg/m2; and group D, morbid obesity with BMI ≥40 kg/m2. All operative data as well as postoperative outcomes are recorded and compared to each other.

RESULTS

The 4 studied groups were matched regarding age. The comorbidities were slightly higher in groups C and D. The operative time and fluoroscopy time were slightly high in obese and morbid obese groups but with no significant difference. The rate of complications either major or minor was comparable in all groups. No significant difference was seen among all groups regarding hemoglobin loss, stone-free rate, hospital stay, and need for auxiliary procedures.

CONCLUSIONS

The outcome of PCNL in flank-free modified supine position is not affected by changes in BMI. The procedure can be performed in obese and morbid obese patients safely with results similar to and comparable to nonobese patients.

Effects of body mass index on the outcomes of percutaneous nephrolithotomy

OBJECTIVE

To examine the the effect of body mass index (BMI) on PNL results and complications with a large number of patients.

MATERIALS AND METHODS

A total of 958 patients were included in the study, who underwent percutaneous nephrolithotomy in our clinic between 2008 and 2015. Patients were divided into 2 groups according to their body mass index. Patients with a BMI < 30 kg/m2 were classified as group 1 (n:676) and patients with a BMI ≥ 30 kg/m2 were classified as group 2 (n:282). Achieving stone-free status or having residual stones of ≤ 4 mm were considered as operational success.

RESULTS

The mean age was 47.9 years for group 1 and 48.9 years for group 2 patients. At postoperative first month CT analysis, residual stone was not observed in 466 patients (69%) of group 1 and 20 (72%) patients of group 2. There was no significant difference between the groups in terms of stone-free status (p=0.348). There was no significant difference between two groups complications. Also, there was no difference between the groups for requiring additional intervention (p=0.924). No other complications were observed in the patients.

CONCLUSIONS

BMI does not affect the outcomes of percutaneous nephrolithotomy as well as complication rate.

Percutaneous Nephrolithotomy in Immunocompromised Patients: Outcomes from a Matched Case-Control Study

OBJECTIVE

To compare the outcomes of percutaneous nephrolithotomy (PCNL) in immunocompromised patients with those of PCNL in healthy population.

PATIENTS AND METHODS

A matched case-control study was performed from January 2009 through December 2014 using our prospectively collected kidney stone database. Patients with positive serology to human immunodeficiency virus (HIV), hepatitis C (cellular immune dysfunction), and patients on high dose of immunosuppressive drugs for treatment of autoimmune diseases composed the case group. Control group included patients with kidney stones and no other comorbidity. Patients were randomly matched based on Guy's score as a surrogate of case complexity.

RESULTS

Sixty-two patients were enrolled in this study, 21 cases and 42 controls. There were no significant differences in age, gender, and body mass index between groups. Regarding PCNL technique, there were no differences in patient positioning, number of accesses, and operative time. Complication rate was higher in the case group (38.1% vs 14.3%; p = 0.032); however, major complications, defined by Clavien score ≥3, were not statistically different (4.8% vs 2.4%; p = 0.611). There was a tendency of more postoperative urinary tract infection in the case group (19% vs 4.8%; p = 0.069). Mean decrease in hemoglobin level (3.3 vs 2.4 mg/dL; p = 0.037) and blood transfusion rate (23.8% vs 4.8%; p = 0.036) was significantly higher in the case group. Immunocompromised patients had a 2.8-fold increased risk of complications (odds ratio [OR] = 2.0, 95% confidence interval [CI] 1.01, 7.74) and a 5.8-fold increased risk of blood transfusion (OR = 5.8, 95% CI 1.29, 26.55). There were no differences in stone-free rate, nephrostomy tube time, and length of hospital stay.

CONCLUSION

Immunocompromised patients are at higher risk for complications such as bleeding after PCNL.

Efficacy and safety of mini percutaneous nephrolithotomy in obese patients

Purpose

We aimed to evaluate the effect of obesity on surgical outcomes of mini percutaneous nephrolithotomy (Mini-PNL).

Methods

Hundred and eighty two Mini-PNL procedures were performed between May 2013 and January 2015 and their results were evaluated retrospectively. Patients were classified as non-obese (BMI, 18.5–30 kg/m²) and obese (≥30 kg/m²) groups. Obese and non-obese patients were compared according to pre-operative demographic values, intra-operative surgery techniques and post-operative results.

Results

BMI values of 133 patients were lower than 30 kg/m² while 49 patient’s BMI values were higher than 30 kg/m². There were no significant difference between operation time, fluoroscopy time, number of access and access sites when two groups were compared. No significant difference was found in total length of hospital stay, hemoglobin drop, and complication rates. Stone-free rates were 70.7 % in the non-obese and 71.4 % in the obese group (p = 0.9).

Conclusions

Mini-PNL procedure is a safe and effective treatment modality, which should be strongly considered for obese patients with appropriate sized stones.

Comparison of miniaturized percutaneous nephrolithotomy and flexible ureterorenoscopy for the management of 10-20 mm renal stones in obese patients

PURPOSE

To evaluate and compare effectivity and safety of flexible ureteroscopy (F-URS) and mini-percutaneous nephrolithotomy (mPNL) for 10-20 mm renal stones in obese patients.

METHODS

Between 2012 and 2015, charts of patients who were treated with F-URS or mPNL for 10-20 mm kidney stone(s) were analyzed. Patients with BMI > 30 kg/m(2) were enrolled into the study. Total of 315 patients were treated with mPNL, and 56 patients were matched our inclusion criteria. In the same period, F-URS was performed in 669 patients, and 157 of them had 10-20 mm kidney stones, and their BMI values were >30 kg/m(2). The patients were retrospectively matched at a 1:1 ratio to index F-URS-mPNL cases with respect to the patient age, gender, ASA score, BMI and size, number, and location of stone.

RESULTS

Gender, age, BMI, stone size, stone number, location of stone(s), and ASA scores were similar between groups. The mean operation time was significantly longer in mPNL group (p: 0.021). However, the mean fluoroscopy time was similar (p: 0.270). Hemoglobin drop requiring blood transfusion and angioembolization was performed in two and one patients after mPNL, respectively. Overall complication rate was significantly higher in mPNL group than F-URS group (30.3 vs. 5.3 %, p: 0.001).

CONCLUSION

Our results demonstrated that both F-URS and mPNL achieve acceptable stone-free rates in obese patients with 10-20 mm renal stones. However, complication rates were significantly lower in F-URS group.

Effect of body mass index on operative time, hospital stay, stone clearance, postoperative complications, and postoperative analgesic requirement in patients undergoing percutaneous nephrolithotomy

OBJECTIVE

To compare the effect of body mass index (BMI) on operative time, hospital stay, stone clearance, postoperative complications, and postoperative analgesic requirement in patients undergoing percutaneous nephrolithotomy (PCNL) by comparing three BMI groups.

MATERIAL AND METHODS

This is a retrospective analysis of 129 patients who underwent PCNL from January 2010 to August 2013. All the patients underwent PCNL by a standard technique. The patients were divided into three groups: patients having a BMI ≤24 kg/m(2) were included in the normal group, those having a BMI of 24.1-30.0 kg/m(2) were included in the overweight group, and those having a BMI >30 kg/m(2) were included in the obese group. Three groups were compared for operative time, hospital stay, stone clearance, postoperative complications, and postoperative analgesic requirement.

RESULTS

A total of 129 patients including 44 females and 85 males were included with a mean age of 45.00±1.44 years. The mean age in the normal group was 43.29±1.69 years, 47.08±1.29 years in the overweight group, and 43.61±1.25 years in the obese group. The mean stone size in the normal group was 25.46±8.92 mm, 28.01±8.40 mm in the overweight group, and 26.84±7.41 mm in the obese group. Our results showed no statistically significant difference with respect to mean operative time, mean hospital stay, and stone clearance in the normal, obese, and overweight patients undergoing PCNL. Postoperative complications and analgesia requirement were also similar in all the three groups.

CONCLUSION

There was no effect of BMI on operative time, hospital stay, stone clearance, postoperative complications, and postoperative analgesic requirement in patients undergoing PCNL. PCNL is a safe and effective procedure for the removal of renal stones in obese patients.

Intrarenal Surgery vs Percutaneous Nephrolithotomy in the Management of Lower Pole Stones Greater than 2 cm

Purpose

To compare the efficacy of RIRS and PNL in lower pole stones ≥2 cm. Materials and and Methods: A total of 109 patients who underwent PNL or RIRS for solitary lower pole stone between April 2009 and December 2012, were retrospectively analyzed. Lower pole stone was diagnosed with CT scan. Stone size was assessed as the longest axis of the stone. All patients were informed about the advantages, disadvantages and probable complications of both PNL and RIRS before the selection of the procedure. Patients decided the surgery type by themselves without being under any influences and written informed consent was obtained from all patients prior to the surgery. Patients were divided into two groups according to the patients’ preference of surgery type. Group 1 consisted of 77 patients who underwent PNL and Group 2 consisted of 32 patients treated with RIRS. Stone free statuses, postoperative complications, operative time and hospitalization time were compared in both groups.

Results

There was no statistical significance between the two groups in mean age, stone size, stone laterality, mean follow-up periods and mean operative times. In PNL group, stone-free rate was 96.1% at first session and 100% after the additional procedure. In Group 2, stone-free rate was 90.6% at the first procedure and 100% after the additional procedure. The final stone-free rates and operative times were similar in both groups.

Conclusions

RIRS should be an effective treatment alternative to PNL in lower pole stones larger than 2 cm, especially in selected patients.

The clinical research office of the endourological society percutaneous nephrolithotomy global study: Outcomes in the morbidly obese patient - a case control analysis

BACKGROUND

Efficacy and safety of percutaneous nephrolithotomy (PCNL) have been demonstrated in obese individuals. Yet, there is a paucity of data on the outcomes of PCNL in morbidly obese patients (body mass index [BMI] >40).

METHODS

Perioperative and stone-related outcomes following PCNL in morbidly obese patients was assessed using a prospective database administered by the Clinical Research Office of the Endourological Society (CROES). A multidimensional match of 97 morbidly obese patients with those of normal weight was created using propensity score matching. Student's t-test and Chi-square tests were used to assess for differences between the groups.

RESULTS

In total, 97 patients with a BMI >40 kg/m(2) were matched by stone characteristics with 97 patients of normal weight. The morbidly obese population demonstrated higher rates of diabetes mellitus (43% vs. 6%, p < 0.001) and cardiovascular disease (56% vs. 18%, (p < 0.001). Access was achieved more frequently by radiologists in the morbidly obese group (19% vs. 6%, p = 0.016). Mean operative duration was longer in the morbidly obese group (112 ± 56 min vs. 86 ± 43.5 min, p < 0.001). Stone-free rates were lower in the morbidly obese group (66% vs. 77%, p = 0.071). There was no significant difference in length of hospital stay or transfusion rate. Morbidly obese patients were significantly more likely to experience a postoperative complication (22% vs. 6%, p = 0.004).

INTERPRETATION

PCNL in morbidly obese patients is associated with longer operative duration, higher rates of re-intervention and an increased risk of perioperative complications. With this knowledge, urologists should seek to develop strategies to optimize the perioperative management of such patients.

Does body mass index effect the success of percutaneous nephrolithotomy?

OBJECTIVE

In obese patients, the management of renal calculi presents a number of challenges for urologists. In this study, we aimed to evaluate the efficacy and safety of percutaneous nephrolithotomy (PNL) procedure in obese and morbidly obese patients.

MATERIAL AND METHODS

We retrospectively reviewed the medical files of 2360 patients treated with PNL between March 2002 and April 2013. The patients were stratified into four groups according to the World Health Organization (WHO) classification of body mass index (BMI): <25 kg/m(2) (average), 25-29.9 kg/m(2) (overweight), 30-39.9 kg/m(2) (obese), and >40 kg/m(2) (morbidly obese). Patients under 18 years of age and those with a body mass index under 18 kg/m(2) were excluded from the study. Intra-, and postoperative outcomes of PNL were compared between groups.

RESULTS

A total of 2102 patients with a mean age of 43±13.62 years were enrolled in the study. The mean stone size, mean number of stones, staghorn stone rate and history of previous shock wave lithotripsy were similar in all groups. The overall stone-free rate was 82 percent. The mean operation time was longer in the morbidly obese group but it was not significantly different from that in the other groups. No differences were observed in hospital stay, complication or stone-free rate among four study groups.

CONCLUSION

Percutaneous nephrolithotomy is a safe and effective treatment for renal stone disease. Body mass index does not affect the success or complication rate in PNL.

Effect of the body mass index on outcomes of flexible ureterorenoscopy

The aim of the study to compare outcomes of flexible ureterorenoscopy in patients with different body mass index (BMI) scores and to explore whether the BMI has an effect on outcomes of RIRS. Five hundred and two patients who underwent flexible URS in 3 centers between 2008 and 2012 for the management of single upper urinary tract calculi were retrospectively reviewed. Patients were categorized as normal weight BMI 18.5 to 24.99 kg/m(2), overweight 25 to 29.99 kg/m(2), obese 30 to 39.99 kg/m(2) and morbid obese >40 kg/m(2).The groups were assessed in terms of demographic parameters including age, gender, stone size, intraoperative and postoperative variables. The mean patient age was 41.3 ± 15.51 (18-81) years and with an average BMI 26.68 ± 5.2 kg/m(2) (16.64-55.15 kg/m²). Of the patients, 43.2 % had normal weight (NW), 32.2 % were overweight (OW), 21.9 % were obese (O) and 2.5 % were morbidly obese (MO). Stone-free rates after single procedure in NW, OW, O, MO groups were 60.8, 61.7, 73.6, 61.5 %, respectively (p = 0.079). Overall targeted stone-free rates were also similar in four groups (88.9, 90.1, 93.6, 90.4 %, p = 0.586). There were no statistically significant differences in the frequency of complications and mean hospitalization time among the groups (p > 0.05). In conclusion, this study demonstrated that flexible URS is a valuable option for the treatment of kidney stone in both obese and non-obese patients. BMI did not influence the postoperative outcomes.

Impact of body mass index on clinical outcomes associated with percutaneous nephrolithotomy

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) is the preferred treatment for patients with large renal calculi or stones that have not responded to extracorporeal shock wave lithotripsy (ESWL). The objective of this study was to compare outcomes and complications of PCNL in patients of various body mass indices (BMI) to determine the safety of this procedure in patients with elevated BMI.

METHODS

A retrospective chart review of 114 patients who underwent PCNL between 2006 and 2009 was performed. Patients were separated into 4 groups with respect to their BMI: (1) ideal body weight (BMI <25 kg/m(2)), (2) overweight (BMW 25-29 kg/m(2)), (3) obese (BMI 30-39 kg/m(2)) and (4) morbidly obese (BMI ≥40 kg/m(2)). One-way ANOVA and univariate logistic regression analysis were used to assess the association between BMI (classified into 4 levels) and variables including age, sex, stone size, length of stay, incidence of complications and stone-free rates.

RESULTS

The distribution of the 114 patients in each BMI category was: ideal body weight 39 (34%), overweight 24 (21%), obese 41 (36%), morbidly obese 10 (9%). There was no difference in the composition of groups with respect to age, sex, pharmacologically treated comorbidities or stone size. Mean length of stay in days, intra- and postoperative complication rates were not statistically different. Stone-free rates showed no significant difference between groups: 90% ideal body weight; 87% overweight; 90% obese; 80% morbidly obese (p = 0.83).

INTERPRETATION

Outcomes of PCNL were statistically independent of BMI. PCNL is a safe and efficacious treatment of stone disease in patients of all sizes.

Monoplanar access technique for percutaneous nephrolithotomy

Percutaneous renal access is the most important step in percutaneous nephrolithotomy (PNL), and the adequacy of access directly affects the success and complication rates of this procedure. We use a monoplanar access technique that is different from biplanar method in that we utilize only fluoroscopic projections maintained on a vertical plane. The aim of this study is to evaluate the effects of this monoplanar access technique on operative outcomes. From October 2009 to December 2011, a total of 200 patients who had renal stones and underwent monoplanar PNL which done by the same surgical team were included in this study. Patient and procedure-related factors were recorded, as well as perioperation and postoperation variables such as operation time, puncture time, fluoroscopy screening time, complication rates, success rates, and duration of hospitalization. The average patient age at the time of procedure was 30.32 years. Mean operation and puncture time were 79.8 and 0.83 min, respectively. Stone-free rate was 80.5 % in postoperative day 1. After additional procedures such as shock wave lithotripsy (SWL), ureterorenoscopy and re-PNL final success rate was 98 % at third month including patients with clinically insignificant residual fragments. There were no severe complications except one patient in whom adjacent organ injury (colon) was observed. Monoplanar access is a safe and effective technique in PNL procedure. Furthermore less puncture time is an advantage of this technique.

Impact of percutaneous renal access technique on outcomes of percutaneous nephrolithotomy

BACKGROUND AND PURPOSE

Percutaneous nephrolithotomy (PCNL) is regarded as the gold standard for the treatment of patients with renal stones larger than 2 cm in diameter. Creating a percutaneous renal access is the initial and probably the most important step in performing a PCNL. Two primary methods of obtaining proper percutaneous renal access under fluoroscopic guidance are described: The "triangulation" and the "eye of the needle" techniques. In this article, we compare these two techniques in terms of success and complication rates.

PATIENTS AND METHODS

From October 2010 to May 2011, 80 patients with simple renal stones were prospectively randomized into two groups according to the percutaneous renal access technique used for PCNL. Patients in group 1 (n=40) were assigned to the eye of the needle technique, and patients in group 2 (n=40) were assigned to the triangulation method. Patients needing multiple access points were excluded from the study. The preoperative, operative, and postoperative follow-up findings were thereafter analyzed and compared.

RESULTS

No significant difference between the two groups was detected in terms of patient demographics (mean patient age, body mass index, stone size, or stone location). The operation time, fluoroscopic screening time (FST), and duration of hospitalization were similar in both groups (P=0.52, P=0.32, P=0.26, respectively). Patients in group 1 had a larger drop in hematocrit postoperatively than patients in group 2 (7.6 ± 3.7 vs 4.8 ± 2.1, P=0.001). The blood transfusion rate (7.5%) was similar in both groups, however. Although the complication rate was higher in group 1 than group 2, no significant difference was detected (20% vs 15%, P=0.76).

CONCLUSIONS

The present study demonstrates that PCNL can be performed safely using two different percutaneous access techniques. The two techniques studied in this trial had similar FSTs, operation and hospitalization times, success rates, and complication rates.

Ureterorenoscopy with holmium-yttrium-aluminum-garnet fragmentation is a safe and efficient technique for stone treatment in patients with a body mass index superior to 30 kg/m2

PURPOSE

The aim of the study was to analyze results and morbidity after flexible ureterorenoscopy in patients with a body mass index (BMI) >30 kg/m(2) and to compare with results obtained in a large cohort of nonobese patients.

PATIENTS AND METHODS

We conducted a retrospective study including all flexible ureterorenoscopy performed for stone retrieval in our institution between January 2004 and December 2008. During the study period, 224 procedures were performed, of which 18 had to be excluded because of missing BMI data. Thus, a total of 206 procedures were included in the final analysis (34 in 29 obese patients, 172 in 149 nonobese patients). Characteristics of the patients (age, BMI, previous treatment), stones (nature, location, number), and procedures (operating time, morbidity, outcome) were analyzed. Success was defined as clear imaging (completely stone free) on renal tomography and ultrasonography at 1, 3, and 6 months follow-up.

RESULTS

Mean BMI was 34±0.6 kg/m(2) in obese patients (OP) and 24±0.2 kg/m(2) in nonobese patients (NOP). Mean stone size, location, and composition were not significantly different between groups. Operative time was also similar in OP and NOP (102.5±6.1 min vs 103±3.4 min, P=NS). The rate of minor complications (fever, hematuria, flank pain) was similar in OP (11.8%) and NOP (11.4%). No major complication necessitating prolonged hospital stay or new surgical procedure was observed. The overall stone-free rate was not significantly different between OP (79.4%) and NOP (70%).

CONCLUSION

Flexible ureterorenoscopy is an appropriate treatment for use in obese patients and achieves excellent stone-free rates with low morbidity.

Difficulties with access in percutaneous renal surgery

Percutaneous renal surgery provides a minimally invasive approach to the kidney for stone extraction in a number of different clinical scenarios. Certain clinical cases present inherent challenges to percutaneous access to the kidney. Herein, we present scenarios in which obtaining and/or maintaining percutaneous access is difficult along with techniques to overcome the challenges commonly encountered. Also, complications associated with these challenging percutaneous renal surgeries are discussed.

Variables that influence operative time during percutaneous nephrolithotomy: an analysis of 1897 cases

BACKGROUND AND PURPOSE

Operative time is an important perioperative factor and is related to postoperative complications and procedural cost-effectiveness. There are few studies, however, investigating factors that affect operative time during percutaneous nephrolithotomy (PCNL). In this study, patient and kidney stone-related factors that influence operative time were analyzed.

MATERIALS AND METHODS

Clinical records from 1897 patients with renal calculi who underwent PCNL were retrospectively reviewed, and these patients were divided into two groups based on their median operative time (group 1: ≤60 min; group 2: >60 min). Multivariate analyses as well as univariate analyses including chi-square, Fisher exact and Mann Whitney U tests were used to investigate the effects of independent variables on operative time, including patient and kidney stone-related factors such as age, sex, body mass index, history of ipsilateral open surgery, shockwave lithotripsy, presence of hydronephrosis, stone burden, stone type and opacity, and surgical experience.

RESULTS

The mean operative time was 64.9±27.6 minutes (range 10-220 min). Univariate analyses determined that a history of open surgery, presence of hydronephrosis, stone type and size, and surgical experience correlated with operative time (P<0.05 for all). Multivariate analyses revealed that presence of hydronephrosis (odds ratio [OR]: 1.44, 95% confidence interval [CI]: 1.17-1.78, P=0.002), stone type (OR: 2.12, 95% CI: 1.69-2.70, P<0.0001), stone burden (OR: 2.44, 95% CI: 1.85-3.12, P<0.0001), and surgical experience (OR: 0.56, 95% CI: 0.46-0.70, P<0.0001) were significant independent factors in influencing operative time.

CONCLUSIONS

Presence of hydronephrosis, renal stone size and type significantly affect the operative time during PCNL. The duration of the operation was also observed to decrease with increased surgical experience.

Operating times and bleeding complications in percutaneous nephrolithotomy: a comparison of tract dilation methods in 5,537 patients in the Clinical Research Office of the Endourological Society Percutaneous Nephrolithotomy Global Study

PURPOSE

The study investigated factors that affect operating times and bleeding complications associated with percutaneous nephrolithotomy (PCNL) in the PCNL Global Study.

PATIENTS AND METHODS

All patients who underwent PCNL for primary or secondary treatment of kidney stone indications during the study period (November 2007-December 2009) were eligible for inclusion. PCNL procedures were performed according to local clinical guidelines and practices. Nephrostomy tract dilation was performed using balloon dilation, metal telescopic dilation, or Amplatz serial dilation. Hematologic complications assessed included bleeding rates, transfusion rates, and preoperative and postoperative hematocrit values.

RESULTS

The median operating time with balloon dilation (n=2277) was significantly longer than with telescopic/serial dilation (n=3260) at 94.0 vs 60.0 minutes, respectively (P<0.0001). In the balloon dilation group, there was significantly more bleeding (9.4% vs 6.7%, respectively; P<0.0001) and more transfusions (7.0% vs 4.9%, respectively; P=0.001) compared with the telescopic/serial dilator group. Univariate analysis showed that the probability of bleeding complications was higher with balloon vs telescopic/serial dilation (odds ratio [OR] 1.75; P=0.0001) and larger sheath size (OR 1.42; P=0.0001). By multivariate analysis, sheath size but not dilation method was predictive of bleeding complications. Other significant predictive factors included operating time, stone load, and caseload.

CONCLUSION

This study shows that in PCNL, factors that are associated with bleeding/transfusion include sheath size, operating time, stone load, and caseload.

Supine versus prone position in percutaneous nephrolithotomy for kidney calculi: a meta-analysis

BACKGROUND

Supine position and prone position were the choice for percutaneous nephrolithotomy (PCNL). However, there is still no consensus on the optimal position for PCNL.

METHODS

A systematic literature review was performed, searching Pubmed, Embase, CENTRAL and reference lists for relevant studies. Data from all selected articles were extracted independently by two reviewers and analyzed by RevMan 5 software.

RESULTS

Four comparative studies involving 389 cases and 27 case series studies including 1,469 renal units of supine position and 4,837 renal units of prone position were identified. With reference to comparative studies, the mean stone length and the proportions of staghorn and multiple stones were comparable between two positions. There was no significant difference in terms of stone-free rate (risk ratio = 1.00, 95% confidence interval: 0.92 to 1.09; 82.4 vs. 82.1%) and bleeding. The rate of colonic injury in supine PCNL was approximate 0.5% and incidence of pleural injury of 0% was noted for both positions. Pelvic perforation and failed access were comparable between supine and prone position. The operative times of supine position significantly decreased (65±15 vs. 90±15 min; mean difference = -24.76, 95% confidence interval: -39.36 to -10.15), but no significant difference was found in mean days hospital stay. Analysis based on the case series showed larger proportion of staghorn and multiple calculi in prone position (45.8 vs. 31.7%), the supine PCNL had slightly lower bleeding and similar stone-free rate compared with the prone position.

CONCLUSIONS

For general patients with kidney calculi, PCNL in supine position has similar stone-free rate compared with prone. Supine PCNL do not increase related complications. The operative times significantly decrease in supine position.

Preoperative indications for percutaneous nephrolithotripsy in 2009

Abstract Since the first description of percutaneous nephrolithotripsy (PNL) over 30 years ago, the indications for this procedure in the management of upper tract urinary stones has greatly expanded. Despite recent advances in shock wave lithotripsy and ureteroscopic technologies, PNL maintains a dominant role in the management of complex and large volume upper tract stones. The contemporary indications for PNL are reviewed herein.

Awake endotracheal intubation and prone patient self-positioning: anesthetic and positioning considerations during percutaneous nephrolithotomy in obese patients

BACKGROUND AND PURPOSE

Obesity is associated with adverse outcomes with certain urologic procedures and may make patient positioning more difficult. We describe our technique of awake intubation and prone patient self-positioning before percutaneous nephrolithotomy (PCNL), and review the literature regarding prone positioning in obese patients and the impact of obesity on PCNL.

METHODS

Patient preparation begins with detailed preoperative counseling regarding the procedure. Premedication with a sedative and antisialagogue is followed by airway topicalization to suppress gag reflex and pain. Fiberoptic bronchoscope intubation is then carried out. The patient then positions himself/herself comfortably before induction of general anesthesia.

RESULTS

We have successfully performed awake intubation and patient prone self-positioning followed by PCNL, most recently in a 58-year-old (body mass index 51.3 kg/m(2)) man with a history of gastric bypass, diabetes mellitus, and hypertension, without added morbidity. Adverse effect on patient cardiopulmonary dynamics can be minimized in the prone position.

CONCLUSIONS

The technique of awake intubation with prone patient self-positioning can be helpful for positioning morbidly obese patients before PCNL and has been safe and effective in properly selected patients. Efficacy of PCNL should not be impacted by obesity or prone positioning and morbidity minimized provided that surgical and anesthesia teams understand and safeguard against potential complications.

Use of a modified syringe barrel to ensure control of the Amplatz sheath during percutaneous nephrolithotripsy in obese patients

Percutaneous nephrolithotripsy (PNL) has been shown to be safe and effective in obese patients. One technical problem specifically encountered in these patients is migration of the Amplatz sheath beneath the skin or muscle fascia. We describe a simple technique, making use of a modified 10-cc syringe barrel, to facilitate retrieval of a migrated access sheath in obese patients undergoing percutaneous nephrolithotripsy. This can also be adopted to prevent loss of the working sheath in the first place, as well as to provide some extra length to access the collecting system avoiding the need to convert to longer instrumentation. This technique is cheap, safe, and effective. It avoids the need to extend the skin incision, resulting in improved cosmesis and reduced postoperative pain.

Rapid prototyping model for percutaneous nephrolithotomy training

PURPOSE

Rapid prototyping is a technique used for creating computer images in three dimensions more efficiently than classic techniques. Percutaneous nephrolithotomy (PCNL) is a popular method to remove kidney stones; however, broader use by the urologic community has been hampered by the morbidity associated with needle puncture to gain access to the renal calix (bleeding, pneumothorax, hydrothorax, inadvertent colon injury). A training model to improve technique and understanding of renal anatomy could improve complications related to renal puncture; however, no model currently exists for resident training.

MATERIALS AND METHODS

We created a training model using the rapid prototyping technique based on abdominal CT images of a patient scheduled to undergo PCNL. This allowed our staff and residents to train on the model before performing the operation. This model allowed anticipation of particular difficulties inherent to the patient's anatomy.

RESULTS

After training, the procedure proceeded without complication, and the patient was discharged at postoperative day 1 without problems.

CONCLUSIONS

We hypothesize that rapid prototyping could be useful for resident education, allowing the creation of numerous models for research and surgical training. In addition, we anticipate that experienced urologists could find this technique helpful in preparation for difficult PCNL operations.

Does the metabolic syndrome or its components affect the outcome of percutaneous nephrolithotomy?

PURPOSE

Metabolic syndrome is a cluster of cardiovascular disease risk factors. We assessed the impact of these medical disorders on the outcome of percutaneous nephrolithotomy (PCNL).

PATIENTS AND METHODS

Data from 430 consecutive PCNL procedures were retrospectively reviewed. The presence of serum lipid abnormalities (SLA), hypertension (HT), diabetes (DM), and obesity was investigated. Patients were determined to have the metabolic syndrome according to the definition of the International Diabetes Federation. Success rate, need for auxiliary procedures, and major complication rates of PCNL were analyzed separately for patients with or without DM, SLA, HT, obesity, and the metabolic syndrome, and were compared.

RESULTS

SLA, HT, and DM were observed in 123 (28.6%), 108 (25.1%), and 44 (10.2%) patients, respectively. Body mass index was >30 kg/m2 in 74 (17.2%) patients. Metabolic syndrome was diagnosed in 41 (9.5%) patients. An overall success rate of 96.3% for PCNL was achieved. Success rates were not significantly (P > 0.05) influenced by the presence of SLA, HT, DM, obesity, or the metabolic syndrome. Major complications were encountered in 49 (11.4%) patients and were 2.5 to 2.7 times more common in patients with DM, HT, and the metabolic syndrome. In patients with DM, auxiliary treatment alternatives were necessary in 20.5%, while they were indicated in 10.9% of patients without DM (P = 0.046). Presence of the metabolic syndrome was also associated with an increased necessity for auxiliary treatments after PCNL (P = 0.048).

CONCLUSIONS

Our results indicate that the metabolic syndrome and its components (DM and HT) significantly augment auxiliary treatment and complication rates after PCNL.

A cost comparison of open versus percutaneous approaches to management of large staghorn calculi

Aim:

This paper compares the cost of open versus percutaneous approaches to the management of large staghorn calculi in a tertiary care hospital in India.

Materials and Methods:

Patients who underwent surgery for staghorn calculi larger than 6 cm between January 1998 and December 2003 were included. Those who had confounding factors in terms of cost such as additional surgical or medical procedures and complications unrelated to the surgery were excluded. The process of costing was done by following the clinical pathway.

Results:

There were 13 patients who had open stone surgery and 19 patients who underwent percutaneous nephrolithotripsy (PCNL). The major differences in cost were seen in the higher cost of instruments and consumables in the PCNL group. The cost of management of complications widened this gap. Two patients in the PCNL group and none in the residual group required redo surgery. The residual stones in the open and PCNL groups required a mean of 2525 and 3623 shocks per patient respectively. Complete clearance after redo surgery and Shockwave lithotripsy (SWL) was seen in 92% and 58% in the open and PCNL arms respectively. The overall cost per patient was $625 per PCNL and $499 per open surgery. The final mean residual stone size in the PCNL group was 4.84 mm whereas it was 0.38 mm in the open group. The effective cost of achieving complete clearance in one patient was $1078 in the PCNL group and $543 in the open group.

Conclusion:

Open stone surgery is less costly than PCNL in large staghorn calculi.

Simultaneous Bilateral Retrograde Intrarenal Surgery for Stone Disease in Patients with Significant Comorbidities

BACKGROUND AND PURPOSE

Advances in endoscopic equipment have allowed urologists to access stones in virtually any location in the upper tracts. Where clinically appropriate, this approach may represent the preferred treatment option, regardless of stone size. We report the first description of simultaneous bilateral retrograde intrarenal surgery (SB-RIRS) in patients with both significant upper-tract stone burdens and comorbidities such as morbid obesity or heart disease.

PATIENTS AND METHODS

Between September 2003 and April 2004, three men and one woman with an average of 62 years underwent a total of seven sessions of SB-RIRS. All four patients were referred from other urologists after failing prior treatments, including shockwave lithotripsy (five sessions) and RIRS (two sessions). The average stone burden was 8.8 cm. The procedures were performed by two surgeons operating simultaneously using two sets of video/holmium laser equipment. Flexible (7.5F) ureteroscopes were used to fragment and basket stone debris without the use of ureteral access sheaths.

RESULTS

Three patients underwent a scheduled second-stage procedure to ensure adequate stone clearance. The average total and SB-RIRS-specific operative times were 256 and 131 minutes for the initial procedure and 235 and 95 minutes for the second-stage procedure, respectively. No major complications were noted.

CONCLUSION

Simultaneous bilateral RIRS is an appropriate treatment option for stone patients with significant comorbidities.

Percutaneous stone surgery in the obese: outcome stratified according to body mass index

OBJECTIVE

To report our experience of percutaneous surgery for treating renal pelvicalyceal stones over 6 years, to show that this approach is feasible and safe in obese and morbidly obese patients, as the prevalence of obesity and stone disease has risen in the last 20 years.

PATIENTS AND METHODS

We retrospectively reviewed the results of 223 percutaneous nephrolithotomies (PCNLs) by one urologist between 1995 and 2001. Patients were stratified into four groups according to the World Health Organization classification of body mass index (BMI), i.e. <25, 25-29.9 (overweight), 30-39.9 (obese) and > 40 kg/m(2) (morbidly obese). The outcomes of surgery in these four groups were compared.

RESULTS

There were no statistically significant differences in operative duration, decrease in haemoglobin concentration, postoperative analgesic use, hospital stay and stone-free rates; nor was there a higher complication rate in patients who were obese.

CONCLUSION

The outcome of PCNL is independent of the patients' BMI and results can be favourable in most patients. We therefore advocate treating obese patients with symptomatic stone disease based on individual status, using percutaneous surgery where appropriate.

The impact of body mass on management of patients with renal colic

OBJECTIVE

To study the impact of body mass on diagnosis and initial response to medical treatment in patients presenting with renal colic.

PATIENTS AND METHODS

One hundred and sixty-five consecutive patients presenting with symptoms of renal colic have been examined. Patients were divided in 3 groups according to their body mass index: normal-weight (BMI < or = 24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2) and obese (BMI > or = 30 kg/m2). Diagnosis of renal colic was based on history, clinical examination, presence of hematuria in a urine sample, appearance of a stone on a plain radiograph, and/or presence of hydronephrosis in ultrasonography. In addition, previous history of renal colic, time to seek medical advice and time to pain relief following administration of medications were examined.

RESULTS

Mean body mass index did not differ between patients with a history of < or = 1, 1-5 and > or = 5 renal colics (P = 0.65). Prevalence rates of appearance of either lithiasis or hydronephrosis vs normal findings on the Kidney-Ureter-Bladder plain radiograph or ultrasonography were not different between normal-weight, overweight and obese subjects (P = 0.38 and P = 0.90 respectively). The time to seek for medical advice and the response to treatment were not different between the study groups (P = 0.24 and P = 0.53 respectively).

CONCLUSION

Body mass does not have any impact on diagnosis, time to seek for medical advice or response to treatment in patients with renal colic.

Practice patterns in the treatment of large renal stones

PURPOSE

To determine the current practice patterns of a large group of urologists in the treatment of large renal stones.

MATERIALS AND METHODS

A survey was sent to all actively practicing members of the North Central Section of the American Urological Association. The questions pertained to age, time in practice, type of practice, time devoted to treating stones, residency training, case scenarios with treatment options, and whether they or a radiologist performed percutaneous access. The data were statistically analyzed.

RESULTS

The response rate was 51% (564/1102 surveys returned). Three quarters (73%) of the urologists were comfortable performing percutaneous nephrolithotomy (PCNL), and 35% gave reasons they do not perform PCNL. Only 11% of those performing PCNL routinely obtained the percutaneous access themselves. Trends in the analysis included: (1) those trained to perform PCNL during residency were more often comfortable with this procedure; (2) younger urologists were more comfortable performing PCNL, even if they had been in practice for only a short time; (3) urologists in private practice were nearly as comfortable performing PCNL as were academic urologists; (4) urologists not comfortable with PCNL more often recommended SWL over PCNL as a primary treatment for moderate/large renal stones; and (5) few urologists routinely obtained percutaneous access themselves.

CONCLUSIONS

Many urologists trained in recent years are comfortable performing PCNL. The type of training received influences treatment recommendations, and percutaneous access is most often obtained by/in conjunction with radiologists. This information may be useful in guiding residency training programs in the preparation of residents for the treatment of large renal stones.

Effect of single-dose subarachnoid spinal anesthesia on pain and recovery after unilateral percutaneous nephrolithotomy

PURPOSE

We studied the impact of one dose of subarachnoid spinal analgesia on postoperative pain and recovery after percutaneous nephrolithotomy (PCNL).

PATIENTS AND METHODS

Between August 1999 and May 2000, 20 PCNL patients were randomized into two groups: Group A (N = 9), who received preoperative subarachnoid spinal analgesia with morphine sulfate, and Group B (N = 11), who received no subarachnoid spinal analgesia. Both groups were given general anesthesia, and the nephrostomy site was infiltrated with bupivacaine hydrochloride. Stone size was similar in the two groups, as were ASA classification, age, and body mass index. Pain analog scales (maximum score 10) were completed preoperatively and on the day of surgery (D0), after 1 day (D1), and after 2 days (D2). The amount of morphine sulfate equivalents (MS eq) needed, the activity level, and adverse effects were recorded.

RESULTS

In Group A, the average pain score on D0, D1, and D2 was 2.7, 3.7, and 1.4, respectively; in Group B, the average pain score was 4, 4.5, and 2, respectively (P > 0.05). The average MS eq used in Groups A and B were 8.3 v 33.8 (P = 0.002) on D0; 17.7 v 28.7 (P > 0.05) on D1; and 11.1 v 10.1 (P > 0.05) on D2. On D0, in Group A, 56% of the patients were ambulating and 11% complained of nausea, while in Group B, 0 were ambulating and 46% complained of nausea.

CONCLUSIONS

A single preoperative dose of subarachnoid spinal analgesia provides a statistically significant decrease in postoperative parenteral pain medication and earlier ambulation. It also appears to reduce the amount of postoperative pain and decrease nausea.

Flexible ureteroscopic lithotripsy: first-line therapy for proximal ureteral and renal calculi in the morbidly obese and superobese patient

BACKGROUND AND PURPOSE

The surgical treatment of kidney and proximal ureteral stones in morbidly obese patients (>14 kg/m2) remains difficult because shockwave lithotripsy is precluded by weight limitations and percutaneous nephrolithotomy is associated with difficult access and a high (9%) rate of transfusion. We review our experience with retrograde ureteroscopic lithotripsy in morbidly obese patients with renal and proximal ureteral stones.

PATIENTS AND METHODS

Between December 1992 and April 2000, five women and three men with a mean age of 46.5 years (range 33-68 years) and a mean body mass index of 54 (range 45-65.2) underwent 10 independent ureteroscopic procedures for urolithiasis. The average stone size was 11.1 mm (range 5-25 mm). Lithotripsy was performed with the holmium laser in eight patients (60%) the electrohydraulic lithotripter in four (30%), and the tunable-dye laser in the remaining patient. Stone-free status was defined as no stones visible on a plain film with nephrotomograms or CT scan at 3 months.

RESULTS

The mean operation time was 101 minutes (range 45-160 minutes), and 60% of the procedures were done on an outpatient basis. After the initial procedure, the stone-free rate was 70%. Two patients had fragments <4 mm, and no further therapy was undertaken. There was one complication: transient renal insufficiency (serum creatinine concentration 3.7 mg/dL) secondary to aminoglycoside toxicity. No transfusions were needed.

CONCLUSION

In the morbidly obese patient with symptomatic stones <1.5 cm, ureteroscopic lithotripsy is safe, successful, and efficient.

Struvite stones: diagnosis and current treatment concepts

Effective management of struvite calculi requires a comprehensive approach to eliminate the stone burden and prevent stone recurrence. These stones occur more frequently in women, infants, and the elderly, as these patients are at greater risk for urinary tract infections. All patients should have routine laboratory testing as well as an excretory urogram. Appropriate urine cultures should be completed. Definitive management should promptly follow diagnosis. Percutaneous nephrolithotomy with or without SWL is the usual treatment. Appropriate antibiotic use is helpful; magnesium and phosphorus restriction and administration of urease inhibitors are less valuable.