A modification of standard percutaneous nephrolithotripsy technique for the morbidly obese patient

Established and Emerging Producers of PHA: Redefining the Possibility

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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.

Percutaneous Nephrolithotomy in Patients With BMI >50: Single Surgeon Outcomes and Feasibility

OBJECTIVE

To evaluate the use of percutaneous nephrolithotomy (PNL) and technical approach in the super obese population (body mass index [BMI] ≥ 50).

MATERIALS AND METHODS

We performed a retrospective review of 31 consecutive PNL cases with a BMI > 50 from a single surgeon (SYN) from 1995 to 2013. Procedures were performed in the prone position, and upper pole access was used. Operative time, length of hospital stay, stone burden, complication rates, and stone-free rates were measured.

RESULTS

Of the 31 patients who underwent PNL (age 51.2 ± 12; 71% female), the mean BMI was 59.1 ± 6 kg/m(2) (range 50.4-71.7 kg/m(2)). Mean stone burden was 3.8 cm ± 2. The majority of patients (90.3%) had an upper pole puncture site for access with an operative time of 122.1 ± 75 minutes. The technique was similar to non-obese patients; however, there was a need for extra-long instrumentation. The overall stone-free rate was 71%, with utilization of a second-look PNL in 11 cases. The complication rate, Clavien grade 3 or higher, was 9.7% (3 of 31).

CONCLUSION

PNL is technically feasible, safe, and effective in patients with a BMI ≥ 50. The complication rate, length of hospital stay, and stone-free rate with use of second-look PNL in super obese patients are comparable to severely obese patients. Intervention should not be automatically ruled out or delayed based on the patient's BMI alone.

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.

Skin-to-stone distance has no impact on outcomes of percutaneous nephrolithotomy

OBJECTIVE

Skin-to-stone distance (SSD) is a stronger factor than body mass index in predicting the success of shock wave lithotripsy. We aimed to evaluate the impact of SSD on outcomes of percutaneous nephrolithotomy (PCNL).

MATERIALS AND METHODS

The medical records of 1,280 patients who had undergone PCNL between April 2007 and February 2012 were evaluated retrospectively. 192 patients who had had preoperative non-contrasted computed tomography and single renal access were included the study. According to this median SSD value, patients were divided into two groups: group 1 (SSD ≤94 mm) (n = 92) and group 2 (SSD >94 mm) (n = 90). The groups were compared according to operative and postoperative parameters.

RESULTS

We found no significant differences between the two groups with regard to stone-free rate, operation time, fluoroscopy time, hospitalization time, visual analog score of pain, stone burden, transfusion rates and complication rates. On the other hand, the mean body mass index of group 1 was significantly lower than that of group 2 (p < 0.05).

CONCLUSIONS

In this retrospective review of patients undergoing PCNL, we found that SSD has no impact on operative and postoperative outcomes. These results were in accordance with the safety of PCNL in obese patients.

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.

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.

Management of renal stone disease in obese patients

Obesity represents an increasing burden to health care resources. Nephrolithiasis is associated with obesity and type 2 diabetes and the consumption of diets rich in protein, fat and carbohydrates; this article addresses some of the pathophysiological mechanisms associated with stone formation in these patients. Management of stone disease can be more difficult in obese patients; even diagnosis can be problematic because imaging techniques are less sensitive in these patients. Treatment with extracorporeal shockwave lithotripsy and surgery in obese patients can be challenging, and outcome data for the different treatments are discussed in this Review.

Outcome of Percutaneous Surgery Stratified According to Body Mass Index and Kidney Stone Size

OBJECTIVE

To stratify outcome and morbidity of percutaneous nephrostolithotomy (PCNL) with regard to body mass index (BMI) and kidney stone burden.

METHODS

The charts of 148 patients who underwent PCNL procedures were reviewed retrospectively. Hospital stay, blood loss, maximal temperature during inpatient stay, and stone-free outcomes were evaluated. Patients were divided into 3 groups depending on their BMIs: <25 kg/m, 25 to 29.9 kg/m, and >30 kg/m. Kidney stone burden was measured in terms of square area in millimeters, as measured by retrospective review of computerized tomography scans. Preoperative computerized tomography scan for measurement of stone burden was available for only 85 patients who are included in the study. Analysis of variance for a single variable was performed with regard to the values of the hospital stay, postoperative maximal temperature, and hemoglobin change.

RESULTS

Of the 85 patients, 37 (43.5%) were obese or morbidly obese (BMI, >30 kg/m), 33 (38.8%) were overweight (BMI, 25 to 29.9 kg/m), and 15 (17.7%) were within or below their ideal weight (BMI, <25 kg/m). No statistically significant difference among the 3 groups was seen for stone-free rate, postoperative fever, or change in hemoglobin when stratified by BMI alone or by BMI and kidney stone burden. However, significantly longer length of stay for the group with BMI <25 kg/m was observed when stratifying either by BMI alone (P=0.01) or by BMI and kidney stone burden (P=0.03).

CONCLUSIONS

In this retrospective review of patients with kidney stones undergoing PCNL, the stone-free outcome and associated morbidity of PCNL (except for the length of hospital stay) is independent of both patients' BMI and stone burden when stratifying by commonly defined parameters.

Outcome of percutaneous nephrolithotomy: effect of body mass index

OBJECTIVE

The surgical management of renal and upper ureteral calculi presents unique challenges in obese patients. We reviewed our recent experience with percutaneous nephrolithotomy (PNL) in obese patients to determine the safety and outcome of this procedure in such group of patients.

PATIENTS AND METHODS

The surgical records of 1121 patients treated with PNL between 2000 and 2004 were reviewed. Patients were stratified into four groups according to the World Health Organization classification of body mass index (BMI): <25 (average), 25-29.9 (overweight), 30-39.9 (obese), and >40 kg/m(2) (morbidly obese). The outcomes of PNL in these four groups were compared.

RESULTS

A total of 1287 procedures were performed on 1155 renal units (1.1 procedures per renal unit). The overall stone-free rate was 85.1% and the mean hospital stay was 3.3+/-2.6 d. Major complications were seen in 72 patients (6.4%). No statistically significant differences were found in decrease in haemoglobin concentration, hospital stay, and complication rate among the four study groups. The need for auxiliary procedures and stone-free rates were comparable.

CONCLUSIONS

PNL in obese and morbidly obese patients yields a stone-free rate that is comparable to that achieved in nonobese patients. The complication rate and length of hospital stay are also similar.

Comment ponctionner un rein pour réaliser une néphrolithotomie percutanée ?

Obtaining a precise percutaneous calyceal puncture gave way to the development of percutaneous nephrolithotomy, one of the first micro-invasive techniques described in urology. Both radiologist and urologist can perform puncture, sometimes in a collaborative effort. However, being followed by a true surgical procedure, it should be done in the O.R; perfect knowledge of the procedure is mandatory for every urologist. Standard guidance uses a fluoroscopic C-arm device, only able to guide the needle precisely towards the apex of the chosen calyx. Moving the C-arm with cephalad tilting will provide 3-D imaging. Ultrasound guidance is an alternative, but might be difficult with non dilated upper tract. CT guidance and retrograde puncture are rarely used. The access is to be adapted according to the patient (adult or child), type of stone (single or multiple access), or kidney position (eutopic or ectopic). Direct ad stable puncture entering the apex of the chosen calyx is a pre-requisite for easy and efficient subsequent nephrolithotomy.

Percutaneous nephrolithotomy with ultrasonography-guided renal access: experience from over 300 cases

OBJECTIVE

To report our experience with over 300 patients treated with percutaneous nephrolithotomy (PNL), for although PNL was established as a treatment in the 1970s, its use diminished with the introduction of extracorporeal shockwave lithotripsy (ESWL); clinical experience with ESWL showed its limitations, and the role of PNL for treating urolithiasis was redefined, which with improvements in instruments and lithotripsy technology has expanded the capability of percutaneous stone disintegration.

PATIENTS AND METHODS

The study included 315 patients (156 males, 159 females, aged 13-85 years) treated with PNL in our department between 1987 and 2002. The mean (range) stone diameter was 27 (7-52) mm. The kidney was punctured under ultrasonography guidance via a lower-pole calyx whenever possible. The working channel was dilated using an Alken dilator under X-ray control. If necessary, a flexible renoscope was used. Ultrasonic, pneumatic and laser probes were used for lithotripsy.

RESULTS

Four weeks after treatment the total stone-free rate was 96.5%; 45.7% of all patients were primarily stone-free, 21.3% had clinically insignificant residual stones that passed spontaneously within 4 weeks after PNL, and 33% of the patients needed auxiliary measures (a second PNL, ESWL, ureterorenoscopy). Overall, the early complication rate was 50.8%, the most common complications being transient fever (27.6%), clinically insignificant bleeding (7.6%) or both (3.2%); 3.5% of the patients developed urinary tract infections (with no signs of urosepsis), 3.2% had renal colic and 2.9% upper urinary tract obstruction. One patient (0.3%) developed acute pancreatitis after PNL; one died from urosepsis and one needed selective angiographic embolization of the punctured kidney due to bleeding. No patient required transfusions and there were no injuries to neighbouring organs.

CONCLUSIONS

These results show that PNL causes no significant blood loss or major complications in almost all patients. Two aspects may especially reduce the potential complications: ultrasonography-guided renal puncture and using PNL in an experienced centre. PNL is a highly efficient procedure that provides fast and safe stone removal.

Urolithiasis and obesity: metabolic and technical considerations

PURPOSE OF REVIEW

The increasing prevalence of obesity poses a challenge to urologists in the diagnosis and treatment of urolithiasis. This review summarizes the new evidence linking obesity and urolithiasis, and the technical considerations and modifications necessary in the diagnosis and treatment of stone disease in obese patients.

RECENT FINDINGS

Recent studies have confirmed the epidemiological link between obesity and urolithiasis, and have provided some possible explanations for its underlying cause. New clinical series have demonstrated that flexible ureterorenoscopy and adapted percutaneous nephrolithotomy techniques can result in similar stone clearance rates and morbidity to the non-obese patient. New data, however, suggest that obesity may be an independent predictor of extracorporeal shock wave lithotripsy treatment failure for ureteric stones. Evidence of the efficacy of dietary modification and medical treatment of metabolic abnormalities has been reported in obese stone formers.

SUMMARY

Urolithiasis can be safely and effectively managed in obese patients with minor modifications to the established surgical techniques. Increased understanding of the underlying metabolic abnormalities in obese patients with urolithiasis may improve prevention strategies in the future.

Tubeless percutaneous renal surgery in obese patients

OBJECTIVES

To assess the outcome and safety of tubeless percutaneous renal surgery in overweight and obese patients.

METHODS

A single urologist performed tubeless percutaneous renal surgery on a total of 138 renal units in 133 patients from March 1996 to January 2003. The tubeless procedures consisted of either nephrolithotripsy or endopyelotomy. We analyzed the clinical data of a subset of these patients who were of considered normal weight (body mass index [BMI] 18.5 kg/m2 or greater but less than 25 kg/m2), overweight (BMI 25 kg/m2 or greater but less than 30 kg/m2), obese (BMI 30 kg/m2 or greater but less than 40 kg/m2), and morbidly obese (BMI 40 kg/m2 or greater).

RESULTS

Of the 133 patients, 5 (3.8%) were considered morbidly obese, 28 (21.1%) were considered obese, 55 (41.4%) were considered overweight, and 45 (34%) were considered to be of normal weight. Of the 133 patients, 104 underwent percutaneous stone extraction and 29 underwent percutaneous antegrade endopyelotomy. Using unpaired t testing, BMI was compared with the transfusion rates, days of hospitalization, and stone-free outcome. The stone group did not demonstrate statistically significant relationships between BMI and transfusion rate, length of hospitalization, and stone-free outcome (P = 0.423, P = 0.105, and P = 0.127, respectively). A stone-free rate of 94.5% was achieved. In the endopyelotomy group, 29 patients were analyzed. Follow-up showed 24 patients (82.8%) had successful resolution of the ureteropelvic junction obstruction 1 year postoperatively. Two patients required readmission for gross hematuria and low hematocrit. One patient required selective angiographic embolization of a pseudoaneurysm.

CONCLUSIONS

Tubeless percutaneous renal surgery is a safe and effective procedure in overweight, obese, and morbidly obese patients.

Bilateral Renal Calculi: Assessment of Staged v Synchronous Percutaneous Nephrolithotomy

BACKGROUND AND PURPOSE

Percutaneous stone removal has replaced open renal surgery and has become the treatment of choice for large or complex renal calculi. However, patients with large bilateral stone burdens still present a challenge. Simultaneous bilateral percutaneous nephrolithotomy (PCNL) has been demonstrated to be a well-tolerated, safe, cost-effective, and expeditious treatment. We present what is, to our knowledge, the first large retrospective series comparing synchronous and asynchronous bilateral PCNL.

PATIENTS AND METHODS

A chart review was performed on 26 patients undergoing 57 PCNLs for bilateral renal calculi over a 7-year period. Seven patients received synchronous PCNL (same anesthesia; Group 1), and 19 patients underwent asynchronous PNL (procedures separated by 1-3 months; Group 2). Complete surgical and hospital records were available on all patients. The average stone burden for Group 1 was 8.03 cm(2) on the left and 9.18 cm(2) on the right v 10.1 cm(2) on the left and 14.23 cm(2) on the right for Group 2 (P> 0.05). Variables of interest included anesthesia time, operative time, blood loss, transfusion rates, length of hospital stay, and complication rates. Each variable was evaluated per operation and per renal unit. Follow-up imaging with stone assessment was available on 20 patients.

RESULTS

Group 1 required 1.14 access tracts per renal unit to attempt complete clearance of the targeted stones v 1.88 tracts per renal unit in Group 2 (P> 0.05). The average operative time per renal unit was significantly less in Group 1 (83 minutes) than in Group 2 (168.5 minutes) (P< 0.0001), as was blood loss (178.5 mL v 307.4 mL, respectively; P= 0.02). However, blood loss per operation was similar at 357 mL in Group 1 and 282 mL in Group 2. Comparable transfusion rates of 28.6% and 36.8%, respectively, were noted. Forty percent of the patients in Group 1 were completely stone free compared with 36% of the patients in Group 2; however, an additional 50% and 57%, respectively, had residual stone burden <4 mm (P> 0.05). Complications occurred in 2 of 7 operations (28%) in Group 1 and 8 of 42 operations (19%) in Group 2. The total length of hospital stay was nearly doubled for patients undergoing staged PCNL (P= 0.0005).

CONCLUSIONS

These results demonstrate similar stone-free rates, blood loss per operation, and transfusion rates for simultaneous and staged bilateral PCNL. The reduced total operative time, hospital stay, and total blood loss, along with the requirement for only one anesthesia, makes synchronous bilateral PCNL an attractive option for select individuals. However, in patients with larger, less easily accessible stones, excessive bleeding may be encountered more frequently on the first side, thereby delaying management of the second side to a later date. Synchronous bilateral PCNL should be considered in patients in whom the first stage of stone removal is accomplished quickly and safely.

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.

Ureteroscopic treatment of renal calculi in morbidly obese patients: a stone-matched comparison

OBJECTIVES

To report a matched comparison of morbidly obese (MO) patients and normal weight (NW) patients who underwent ureteroscopic (URS) treatment of renal calculi. Shock wave lithotripsy and percutaneous nephrostolithotomy may be precluded in MO patients, and URS treatment offers a minimally invasive alternative.

METHODS

We retrospectively reviewed the charts of patients who underwent URS at our institution between 1997 and 2000. Fifty-four patients underwent URS treatment solely for renal calculi. Sixteen MO patients underwent 18 procedures. Thirty-eight NW patients, who underwent 39 procedures, were matched to the MO patients by stone location and size. Stones were categorized by location and size, less than 10 mm or 10 mm or greater. The factors and outcomes assessed were stone length, operative time, presence of a ureteral stent, success, and complications.

RESULTS

The overall success rate was 83% (15 of 18 procedures) for MO patients and 67% (26 of 39 procedures) for NW patients, but this difference was not significant (P = 0.23). The difference in the success rate for renal calculi 10 mm or greater (100% versus 38%) approached significance (P = 0.09). This may be related to other distinctions between the groups. URS treatment was often a salvage therapy in the NW group after other modalities failed. No significant differences were found between the other outcomes.

CONCLUSIONS

URS treatment of renal calculi when matched for location and size is as successful and no more morbid in MO than in NW patients. URS treatment of renal calculi is a safe and effective first-line treatment for renal calculi in MO patients.

Obstáculos diagnósticos e desafios terapêuticos no paciente obeso

Obesidade é uma doença complexa, de mútiplas etiologias e suficientemente comum para constituir um problema de saúde pública, assim como um dilema clínico importante. Especialistas da área clínica e cirúrgica são freqüentemente desafiados pelas alterações fisiopatológicas associadas com a obesidade. Essas alterações comprometem virtualmente todos os sistemas do organismo, podendo apresentar-se como barreiras no diagnóstico e na terapêutica. Há evidências marcantes de que obesidade acarreta risco excessivo para a saúde; de fato, a mortalidade aumenta de forma aguda quando o índice de massa corporal ultrapassa 30 kg/m2, principalmente quando há distribuição central de tecido adiposo concomitante. O autor discute os efeitos da obesidade nos sistemas respitatório, cardiovascular, digestório e geniturinário. Os obstáculos enfrentados em procedimentos diagnósticos ordinários, prescrição de medicamentos, traumas, assim como descrições patológicas raras de lipomas, são apresentados.

Renal calculi. Percutaneous management

Percutaneous nephrolithotomy has established indications and is performed with high success and minimal morbidity. Patients who have large or hard stones or stones associated with urinary obstruction are candidates for a percutaneous procedure. When the certainty of the final result is important, the patient should have a PNL. In general, the best treatment for SWL failure is not more SWL; such patients usually should have an endoscopic procedure.

Outcomes of contemporary percutaneous nephrostolithotomy in morbidly obese patients

PURPOSE

The surgical management of renal and ureteral calculi presents unique challenges in the obese patient. We reviewed our recent experience with percutaneous nephrostolithotomy in patients with a body mass index greater than 30.

MATERIALS AND METHODS

We reviewed the records of 236 patients undergoing percutaneous nephrostolithotomy between August 1994 and March 1997 at 2 university and affiliated hospitals. Among this group 57 patients had a body mass index greater than 30 (mean plus or minus standard deviation 38.9 +/- 7.4). Renal anomalies were present in 21% of patients and more than half (56%) had co-morbidities in addition to obesity. Staghorn calculi were present in 19 patients (31.7%). In the remaining patients the mean cumulative stone size for single or multiple stones was 14.5 +/- 8.7 mm. Stone-free status after the procedure was determined by plain nephrotomograms or noncontrast computerized tomography.

RESULTS

A total of 96 procedures were performed on 60 renal units (1.6 procedures per renal unit). Average operative time for the initial procedure was 181.2 +/- 91.4 minutes. Complications occurred in 8 patients (14%) and 5 (8.8%) received a blood transfusion. Average hospital stay was 4.9 +/- 3.1 days. The overall stone-free rate was 88.3%, and stone-free rate for staghorn calculi was 84.2% compared with 90.2% for nonstaghorn calculi.

CONCLUSIONS

Percutaneous nephrostolithotomy in obese patients yields a stone-free rate that is comparable to that achieved in an unselected patient population. The complication rate, transfusion rate and hospital stay are also similar. Modifications to standard technique and instrumentation are sometimes necessary to perform percutaneous nephrostolithotomy in this group of patients.

Outcomes of contemporary percutaneous nephrostolithotomy in morbidly obese patients

PURPOSE

The surgical management of renal and ureteral calculi presents unique challenges in the obese patient. We reviewed our recent experience with percutaneous nephrostolithotomy in patients with a body mass index greater than 30.

MATERIALS AND METHODS

We reviewed the records of 236 patients undergoing percutaneous nephrostolithotomy between August 1994 and March 1997 at 2 university and affiliated hospitals. Among this group 57 patients had a body mass index greater than 30 (mean plus or minus standard deviation 38.9 +/- 7.4). Renal anomalies were present in 21% of patients and more than half (56%) had co-morbidities in addition to obesity. Staghorn calculi were present in 19 patients (31.7%). In the remaining patients the mean cumulative stone size for single or multiple stones was 14.5 +/- 8.7 mm. Stone-free status after the procedure was determined by plain nephrotomograms or noncontrast computerized tomography.

RESULTS

A total of 96 procedures were performed on 60 renal units (1.6 procedures per renal unit). Average operative time for the initial procedure was 181.2 +/- 91.4 minutes. Complications occurred in 8 patients (14%) and 5 (8.8%) received a blood transfusion. Average hospital stay was 4.9 +/- 3.1 days. The overall stone-free rate was 88.3%, and stone-free rate for staghorn calculi was 84.2% compared with 90.2% for nonstaghorn calculi.

CONCLUSIONS

Percutaneous nephrostolithotomy in obese patients yields a stone-free rate that is comparable to that achieved in an unselected patient population. The complication rate, transfusion rate and hospital stay are also similar. Modifications to standard technique and instrumentation are sometimes necessary to perform percutaneous nephrostolithotomy in this group of patients.

Endoscopic management of urolithiasis in the morbidly obese patient

A retrospective review of 48 consecutive morbidly obese patients with urolithiasis who were treated successfully by endoscopic modalities over 3.5 years was performed. Of the 73 endoscopic procedures, 48 were ureteroscopic laser lithotripsy (UL), 4 were ureteroscopic basket extraction, and 21 were percutaneous nephrolithotripsy (PCNL). The patients' weight ranged from 205 to 385 lbs. (average 286 lbs.). Their abdominal girth ranged from 53 to 65 inches (average 59 inches). Twenty-six patients had one procedure, eight patients had bilateral procedures, eleven patients had two procedures, and three patients had three procedures with utilization of either multiple ureteroscopic treatments or the combination of percutaneous and ureteroscopic techniques. The stone-free rate after one procedure was 77.8% for UL and 60% for PCNL. The stone-free rate after planned repeat procedures was 97% for UL/UL and 89% for PCNL/UL. There were two minor complications. Forty-eight procedures were performed on an outpatient basis, and the remaining 25 procedures necessitated hospital admission (average 3.6 days). Morbidly obese patients with urolithiasis who are unable to have SWL because of their body weight and abdominal girth can be treated successfully with UL, ureteroscopic basket extraction, and PCNL with efficacy comparable to that in patients of normal weight and with minimal morbidity. Many renal calculi were treated with UL alone with a high success rate.

Percutaneous nephrostolithotomy. What is its role in 1997?

PNL is a challenging and satisfying part of endourologic practice. Although more invasive than SWL or ureteroscopy, it offers a high chance of success in many different situations. The selective and appropriate application of PNL requires the consideration of many factors, especially stone location and size, patient habitus, and the anatomy of the upper urinary tract (Table 5). For the urologic surgeon in the last decade of the twentieth century, complete stone therapy entails judgment and skill with myriad modalities: SWL, ureteroscopy, PNL, and open or laparoscopic stone surgery.